Clean import of TCP-wrappers by Wietse Venema.

Rest of build to follow.
This commit is contained in:
Mark Murray 1999-03-14 17:13:19 +00:00
commit 2aef693010
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/vendor/tcp_wrappers/dist/; revision=44743
svn path=/vendor/tcp_wrappers/7.6/; revision=44745; tag=vendor/tcp_wrappers/7.6
56 changed files with 9731 additions and 0 deletions

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@(#) BLURB 1.28 97/03/21 19:27:18
With this package you can monitor and filter incoming requests for the
SYSTAT, FINGER, FTP, TELNET, RLOGIN, RSH, EXEC, TFTP, TALK, and other
network services.
The package provides tiny daemon wrapper programs that can be installed
without any changes to existing software or to existing configuration
files. The wrappers report the name of the client host and of the
requested service; the wrappers do not exchange information with the
client or server applications, and impose no overhead on the actual
conversation between the client and server applications.
This patch upgrades the tcp wrappers version 7.5 source code to
version 7.6. The source-routing protection in version 7.5 was not
as strong as it could be. And all this effort was not needed with
modern UNIX systems that can already stop source-routed traffic in
the kernel. Examples are 4.4BSD derivatives, Solaris 2.x, and Linux.
This release does not introduce new features. Do not bother applying
this patch when you built your version 7.x tcp wrapper without
enabling the KILL_IP_OPTIONS compiler switch; when you can disable
IP source routing options in the kernel; when you run a UNIX version
that pre-dates 4.4BSD, such as SunOS 4. Such systems are unable to
receive source-routed connections and are therefore not vulnerable
to IP spoofing attacks with source-routed TCP connections.
A complete change log is given in the CHANGES document. As always,
problem reports and suggestions for improvement are welcome.
Wietse Venema (wietse@wzv.win.tue.nl),
Department of Mathematics and Computing Science,
Eindhoven University of Technology,
The Netherlands.
Currently visiting IBM T.J. Watson Research, Hawthorne NY, USA.

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# @(#) Banners.Makefile 1.3 97/02/12 02:13:18
#
# Install this file as the Makefile in your directory with banner files.
# It will convert a prototype banner text to a form that is suitable for
# the ftp, telnet, rlogin, and other services.
#
# You'll have to comment out the IN definition below if your daemon
# names don't start with `in.'.
#
# The prototype text should live in the banners directory, as a file with
# the name "prototype". In the prototype text you can use %<character>
# sequences as described in the hosts_access.5 manual page (`nroff -man'
# format). The sequences will be expanded while the banner message is
# sent to the client. For example:
#
# Hello %u@%h, what brings you here?
#
# Expands to: Hello username@hostname, what brings you here? Note: the
# use of %u forces a client username lookup.
#
# In order to use banners, build the tcp wrapper with -DPROCESS_OPTIONS
# and use hosts.allow rules like this:
#
# daemons ... : clients ... : banners /some/directory ...
#
# Of course, nothing prevents you from using multiple banner directories.
# For example, one banner directory for clients that are granted service,
# one banner directory for rejected clients, and one banner directory for
# clients with a hostname problem.
#
SHELL = /bin/sh
IN = in.
BANNERS = $(IN)telnetd $(IN)ftpd $(IN)rlogind # $(IN)fingerd $(IN)rshd
all: $(BANNERS)
$(IN)telnetd: prototype
cp prototype $@
chmod 644 $@
$(IN)ftpd: prototype
sed 's/^/220-/' prototype > $@
chmod 644 $@
$(IN)rlogind: prototype nul
( ./nul ; cat prototype ) > $@
chmod 644 $@
# Other services: banners may interfere with normal operation
# so they should probably be used only when refusing service.
# In particular, banners don't work with standard rsh daemons.
# You would have to use an rshd that has built-in tcp wrapper
# support, for example the rshd that is part of the logdaemon
# utilities.
$(IN)fingerd: prototype
cp prototype $@
chmod 644 $@
$(IN)rshd: prototype nul
( ./nul ; cat prototype ) > $@
chmod 644 $@
# In case no /dev/zero available, let's hope they have at least
# a C compiler of some sort.
nul:
echo 'main() { write(1,"",1); return(0); }' >nul.c
$(CC) $(CFLAGS) -s -o nul nul.c
rm -f nul.c

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Request: after building the programs, please run the `tcpdchk' wrapper
configuration checker. See the `tcpdchk.8' manual page (`nroff -man'
format) for instructions. `tcpdchk' automatically identifies the most
common configuration problems, and will save you and me a lot of time.
Changes per release 7.6 (Mar 1997)
==================================
- Improved the anti source-routing protection. The code in version
7.5 was not as strong as it could be, because I tried to be compatible
with Linux. That was a mistake. Sorry for the inconvenience.
- The program no longer terminates case of a source-routed connection,
making the IP-spoofing code more usable for long-running daemons.
- When syslogging DNS hostname problems, always stop after a limited
number of characters.
Changes per release 7.5 (Feb 1997)
==================================
- Optionally refuse source-routed TCP connections requests altogether.
Credits to Niels Provos of Universitaet Hamburg. File: fix_options.c.
- Support for IRIX 6 (Lael Tucker).
- Support for Amdahl UTS 2.1.5 (Richard E. Richmond).
- Support for SINIX 5.42 (Klaus Nielsen).
- SCO 5 now has vsyslog() (Bill Golden).
- Hints and tips for dealing with IRIX inetd (Niko Makila, Aaron
M Lee).
- Support for BSD/OS (Paul Borman).
- Support for Tandem (Emad Qawas).
- Support for ISC (Frederick B. Cohen).
- Workaround for UNICOS - it would choke on a setjmp() expression
(Bruce Kelly). File: hosts_access.c, tcpdchk.c.
- Increased the level of buffer overflow paranoia when printing
unwanted IP options. File: fix_options.c.
Changes per release 7.4 (Mar 1996)
==================================
- IRIX 5.3 (and possibly, earlier releases, too) library routines call
the non-reentrant strtok() routine. The result is that hosts may slip
through allow/deny filters. Workaround is to not rely on the vendor's
strtok() routine (#ifdef LIBC_CALLS_STRTOK). Credits to Th. Eifert
(Aachen University) for spotting this one. This fix supersedes the
earlier workaround for a similar problem in FreeBSD 2.0.
Changes per release 7.3 (Feb 1996)
==================================
- More tests added to tcpdchk and tcpdmatch: make sure that the
REAL_DAEMON_DIR actually is a directory and not a regular file;
detect if tcpd recursively calls itself.
- Edwin Kremer found an amusing fencepost error in the xgets()
routine: lines longer than BUFLEN characters would be garbled.
- The access control routines now refuse to execute "dangerous" actions
such as `twist' when they are called from within a resident process.
This prevents you from shooting yourself into the foot with critical
systems programs such as, e.g., portmap or rpcbind.
- Support for Unicos 8.x (Bruce Kelly). The program now closes the
syslog client socket before running the real daemon: Cray UNICOS
refuses to checkpoint processes with open network ports.
- Support for MachTen UNIX (Albert M.C Tam).
- Support for Interactive UNIX R3.2 V4.0 (Bobby D. Wright).
- Support for SCO 3.2v5.0.0 OpenServer 5 (bob@odt.handy.com)
- Support for Unixware 1.x and Unixware 2.x. The old Unixware Makefile
rule was broken. Sorry about that.
- Some FreeBSD 2.0 libc routines call strtok() and severely mess up the
allow/deny rule processing. This is very bad. Workaround: call our own
strtok() clone (#ifdef USE_STRSEP).
- The programs now log a warning when they detect that a non-existent
banner directory is specified.
- The hosts_access.3 manual page used obsolete names for the RQ_*
constants.
Changes per release 7.2 (Jan 1995)
==================================
- Added a note to the README and manpages on using the IDENT service to
detect sequence number spoofing and other host impersonation attacks.
- Portability: ConvexOS puts RPC version numbers before the daemon path
name (Jukka Ukkonen).
- Portability: the AIX compiler disliked the strchr() declaration
in socket.c. I should have removed it when I included <string.h>.
- Backwards compatibility: some people relied on the old leading dot or
trailing dot magic in daemon process names.
- Backwards compatibility: hostname lookup remains enabled when
-DPARANOID is turned off. In order to disable hostname lookups you
must turn off -DALWAYS_HOSTNAME.
- Eliminated false complaints from the tcpdmatch/tcpdchk configuration
checking programs about process names not in inetd.conf or about KNOWN
username patterns.
Changes per release 7.1 (Jan 1995)
==================================
- Portability: HP-UX permits you to break inetd.conf entries with
backslash-newline.
- Portability: EP/IX has no putenv() and some inetd.conf entries are
spread out over two lines.
- Portability: SCO with NIS support has no *netgrent() routines.
Changes per release 7.0 (Jan 1995)
==================================
- Added a last-minute workaround for a Solaris 2.4 gethostbyname()
foulup with multi-homed hosts in DNS through NIS mode.
- Added a last-minute defense against TLI weirdness: address lookups
apparently succeed but the result netbuf is empty (ticlts transport).
- Dropped several new solutions that were in need of a problem. Beta
testers may recognize what new features were kicked out during the last
weeks before release 7.0 came out. Such is life.
- Got rid of out the environment replacement routines, at least for
most architectures. One should not have to replace working system
software when all that is needed is a 4.4BSD setenv() emulator.
- By popular request I have added an option to send banner messages to
clients. There is a Banners.Makefile that gives some aid for sites that
are going to use this feature. John C. Wingenbach did some pioneering
work here. I used to think that banners are frivolous. Now that I had
a personal need for them I know that banners can be useful.
- At last: an extensible functional interface to the pattern matching
engine. request_init() and request_set() accept a variable-length
name-value argument list. The result can be passed to hosts_access().
- When PARANOID mode is disabled (compile time), the wrapper does no
hostname lookup or hostname double checks unless required by %letter
expansions, or by access control rules that match host names. This is
useful for sites that don't care about internet hostnames anyway.
Inspired by the authors of the firewalls and internet security book.
- When PARANOID mode is disabled (compile time), hosts with a name/name
or name/address conflict can be matched with the PARANOID host wildcard
pattern, so that you can take some intelligent action instead of just
dropping clients. Like showing a banner that explains the problem.
- New percent escapes: %A expands to the server address; %H expands to
the corresponding hostname (or address if no name is available); %n and
%N expand to the client and server hostname (or "unknown"); %s expands
to everything we know about the server endpoint (the opposite of the %c
sequence for client information).
- Symmetry: server and client host information is now treated on equal
footing, so that we can reuse a lot of code.
- Lazy evaluation of host names, host addresses, usernames, and so on,
to avoid doing unnecessary work.
- Dropping #ifdefs for some archaic systems made the code simpler.
- Dropping the FAIL pattern made the pattern matcher much simpler. Run
the "tcpdchk" program to scan your access control files for any uses of
this obscure language feature.
- Moving host-specific pattern matching from string_match() to the
host_match() routine made the code more accurate. Run the "tcpdchk"
program to scan your access control files for any dependencies on
undocumented or obscure language features that are gone.
- daemon@host patterns trigger on clients that connect to a specific
internet address. This can be useful for service providers that offer
multiple ftp or www archives on different internet addresses, all
belonging to one and the same host (www.foo.com, ftp.bar.com, you get
the idea). Inspired by a discussion with Rop Gonggrijp, Cor Bosman,
and Casper Dik, and earlier discussions with Adrian van Bloois.
- The new "tcpdchk" program critcizes all your access control rules and
inetd.conf entries. Great for spotting obscure bugs in my own hosts.xxx
files. This program also detects hosts with name/address conflicts and
with other DNS-related problems. See the "tcpdchk.8" manual page.
- The "tcpdmatch" program replaces the poor old "try" command. The new
program looks in your inetd.conf file and therefore produces much more
accurate predictions. In addition, it detects hosts with name/address
conflicts and with other DNS-related problems. See the "tcpdmatch.8"
manual page. The inetd.conf lookup was suggested by Everett F Batey.
- In the access control tables, the `=' between option name and value
is no longer required.
- Added 60-second timeout to the safe_finger command, to cover another
potential problem. Suggested by Peter Wemm.
- Andrew Maffei provided code that works with WIN-TCP on NCR System V.4
UNIX. It reportedly works with versions 02.02.01 and 02.03.00. The code
pops off all streams modules above the device driver, pushes the timod
module to get at the peer address, and then restores the streams stack
to the initial state.
Changes per release 6.3 (Mar 1994)
==================================
- Keepalives option, to get rid of stuck daemons when people turn off
their PC while still connected. Files: options.c, hosts_options.5.
- Nice option, to calm down network daemons that take away too much CPU
time. Files: options.c, hosts_options.5.
- Ultrix perversion: the environ global pointer may be null. The
environment replacement routines now check for this. File: environ.c.
- Fixed a few places that still assumed the socket is on standard
input. Fixed some error messages that did not provide access control
file name and line number. File: options.c.
- Just when I was going to release 6.2 I received code for Dynix/PTX.
That code is specific to PTX 2.x, so I'll keep around my generic
PTX code just in case. The difference is in the handling of UDP
services. Files: tli_sequent.[hc].
Changes per release 6.2 (Feb 1994)
==================================
- Resurrected my year-old code to reduce DNS load by appending a dot to
the gethostbyname() argument. This feature is still experimental and it
may go away if it causes more problems than it solves. File: socket.c.
- Auxiliary code for the Pyramid, BSD universe. Karl Vogel figured out
what was missing: yp_get_default_domain() and vfprintf(). Files:
workarounds.c, vfprintf.c.
- Improved support for Dynix/PTX. The wrapper should now be able to
deal with all TLI over IP services. File: ptx.c.
- The try command now uses the hostname that gethostbyaddr() would
return, instead of the hostname returned by gethostbyname(). This can
be significant on systems with NIS that have short host names in the
hosts map. For example, gethostbyname("wzv.win.tue.nl") returns
"wzv.win.tue.nl"; gethostbyaddr(131.155.210.17) returns "wzv", and
that is what we should test with. File: try.c.
Changes per release 6.1 (Dec 1993)
==================================
- Re-implemented all environment access routines. Most systems have
putenv() but no setenv(), some systems have setenv() but no putenv(),
and there are even systems that have neither setenv() nor putenv(). The
benefit of all this is that more systems can now be treated in the same
way. File: environ.c.
- Workaround for a weird problem with DG/UX when the wrapper is run as
nobody (i.e. fingerd). For some reason the ioctl(fd, I_FIND, "sockmod")
call fails even with socket-based applications. The "fix" is to always
assume sockets when the ioctl(fd, I_FIND, "timod") call fails. File:
fromhost.c. Thanks to Paul de Vries (vries@dutentb.et.tudelft.nl) for
helping me to figure out this one.
- Implemented a workaround for Dynix/PTX and other systems with TLI
that lack some essential support routines. Thanks to Bugs Brouillard
(brouill@hsuseq.humboldt.edu) for the hospitality to try things out.
The trick is to temporarily switch to the socket API to identify the
client, and to switch back to TLI when done. It still does not work
right for basic network services such as telnet. File: fromhost.c.
- Easy-to-build procedures for SCO UNIX, ConvexOS with UltraNet, EP/IX,
Dynix 3.2, Dynix/PTX. File: Makefile.
- Variable rfc931 timeout. Files: rfc931.c, options.c, log_tcp.h, try.c.
- Further simplification of the rfc931 code. File: rfc931.c.
- The fromhost() interface stinks: I cannot change that, but at least
the from_sock() and from_tli() functions now accept a file descriptor
argument.
- Fixed a buglet: fromhost() would pass a garbage file descriptor to
the isastream() call.
- On some systems the finger client program lives in /usr/bsd. File:
safe_finger.c.
Changes per release 6.0 (Sept 1993)
===================================
- Easy build procedures for common platforms (sun, ultrix, aix, hpux
and others).
- TLI support, System V.4 style (Solaris, DG/UX).
- Username lookup integrated with the access control language.
Selective username lookups are now the default (was: no username
lookups).
- A safer finger command for booby traps. This one solves a host of
possible problems with automatic reverse fingers. Thanks, Borja Marcos
(borjam@we.lc.ehu.es) for some inspiring discussions.
- KNOWN pattern that matches hosts whose name and address are known.
- Cleanup of diagnostics. Errors in access-control files are now shown
with file name and line number.
- With AIX 3.2, hostnames longer than 32 would be truncated. This
caused hostname verification failures, so that service would be refused
when paranoid mode was enabled. Found by: Adrian van Bloois
(A.vanBloois@info.nic.surfnet.nl).
- With some IRIX versions, remote username lookups failed because the
fgets() library function does not handle partial read()s from sockets.
Found by: Daniel O'Callaghan (danny@austin.unimelb.edu.au).
- Added a DISCLAIMER document to help you satisfy legal departments.
The extension language module has undergone major revisions and
extensions. Thanks, John P. Rouillard (rouilj@ra.cs.umb.edu) for
discussions, experiments, and for being a good guinea pig. The
extensions are documented in hosts_options.5, and are enabled by
editing the Makefile STYLE macro definition.
- (Extension language) The ":" separator may now occur within options
as long as it is protected with a backslash. A warning is issued when
a rule ends on ":".
- (Extension language) Better verification mode. When the `try' command
is run, each option function now explains what it would do.
- (Extension language) New "allow" and "deny" keywords so you can now
have all rules within a single file. See "nroff -man hosts_options.5"
for examples.
- (Extension language) "linger" keyword to set the socket linger time
(SO_LINGER). From: Marc Boucher <marc@cam.org>.
- (Extension language) "severity" keyword to turn the logging noise up
or down. Many sites wanted a means to shut up the program; other sites
wanted to emphasize specific events. Adapted from code contributed
by Dave Mitchell <D.Mitchell@dcs.shef.ac.uk>.
Changes per release 5.1 (Mar 1993)
==================================
- The additional protection against source-routing attacks from hosts
that pretend to have someone elses network address has become optional
because it causes kernel panics with SunOS <= 4.1.3.
Changes per release 5.0 (Mar 1993)
==================================
- Additional protection against source-routing attacks from hosts that
pretend to have someone elses network address. For example, the address
of a trusted host within your own network.
- The access control language has been extended with a simple but
powerful operator that greatly simplifies the design of rule sets (ALL:
.foo.edu EXCEPT dialup.foo.edu). Blank lines are permitted, and long
lines can be continued with backslash-newline.
- All configurable stuff, including path names, has been moved into the
Makefile so that you no longer have to hack source code to just
configure the programs.
- Ported to Solaris 2. TLI-based applications not yet supported.
Several workarounds for System V bugs.
- A small loophole in the netgroup lookup code was closed, and the
remote username lookup code was made more portable.
- Still more documentation. The README file now provides tutorial
sections with introductions to client, server, inetd and syslogd.
Changes per release 4.3 (Aug 1992)
==================================
- Some sites reported that connections would be rejected because
localhost != localhost.domain. The host name checking code now
special-cases localhost (problem reported by several sites).
- The programs now report an error if an existing access control file
cannot be opened (e.g. due to lack of privileges). Until now, the
programs would just pretend that the access control file does not exist
(reported by Darren Reed, avalon@coombs.anu.edu.au).
- The timeout period for remote userid lookups was upped to 30 seconds,
in order to cope with slow hosts or networks. If this is too long for
you, adjust the TIMEOUT definition in file rfc931.c (problem reported
by several sites).
- On hosts with more than one IP network interface, remote userid
lookups could use the IP address of the "wrong" local interface. The
problem and its solution were discussed on the rfc931-users mailing
list. Scott Schwartz (schwartz@cs.psu.edu) folded the fix into the
rfc931.c module.
- The result of % expansion (in shell commands) is now checked for
stuff that may confuse the shell; it is replaced by underscores
(problem reported by Icarus Sparry, I.Sparry@gdr.bath.ac.uk).
- A portability problem was fixed that caused compile-time problems
on a CRAY (problem reported by Michael Barnett, mikeb@rmit.edu.au).
Changes per release 4.0 (Jun 1992)
==================================
1 - network daemons no longer have to live within a common directory
2 - the access control code now uses both the host address and name
3 - an access control pattern that supports netmasks
4 - additional protection against forged host names
5 - a pattern that matches hosts whose name or address lookup fails
6 - an operator that prevents hosts or services from being matched
7 - optional remote username lookup with the RFC 931 protocol
8 - an optional umask to prevent the creation of world-writable files
9 - hooks for access control language extensions
10 - last but not least, thoroughly revised documentation.
Changes per release 3.0 (Oct 1991)
==================================
Enhancements over the previous release are: support for datagram (UDP
and RPC) services, and execution of shell commands when a (remote host,
requested service) pair matches a pattern in the access control tables.
Changes per release 2.0 (May 1991)
==================================
Enhancements over the previous release are: protection against rlogin
and rsh attacks through compromised domain name servers, optional
netgroup support for systems with NIS (formerly YP), and an extension
of the wild card patterns supported by the access control files.
Release 1.0 (Jan 1991)

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/************************************************************************
* Copyright 1995 by Wietse Venema. All rights reserved. Some individual
* files may be covered by other copyrights.
*
* This material was originally written and compiled by Wietse Venema at
* Eindhoven University of Technology, The Netherlands, in 1990, 1991,
* 1992, 1993, 1994 and 1995.
*
* Redistribution and use in source and binary forms are permitted
* provided that this entire copyright notice is duplicated in all such
* copies.
*
* This software is provided "as is" and without any expressed or implied
* warranties, including, without limitation, the implied warranties of
* merchantibility and fitness for any particular purpose.
************************************************************************/

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# @(#) Makefile 1.23 97/03/21 19:27:20
what:
@echo
@echo "Usage: edit the REAL_DAEMON_DIR definition in the Makefile then:"
@echo
@echo " make sys-type"
@echo
@echo "If you are in a hurry you can try instead:"
@echo
@echo " make REAL_DAEMON_DIR=/foo/bar sys-type"
@echo
@echo "And for a version with language extensions enabled:"
@echo
@echo " make REAL_DAEMON_DIR=/foo/bar STYLE=-DPROCESS_OPTIONS sys-type"
@echo
@echo "This Makefile knows about the following sys-types:"
@echo
@echo " generic (most bsd-ish systems with sys5 compatibility)"
@echo " 386bsd aix alpha apollo bsdos convex-ultranet dell-gcc dgux dgux543"
@echo " dynix epix esix freebsd hpux irix4 irix5 irix6 isc iunix"
@echo " linux machten mips(untested) ncrsvr4 netbsd next osf power_unix_211"
@echo " ptx-2.x ptx-generic pyramid sco sco-nis sco-od2 sco-os5 sinix sunos4"
@echo " sunos40 sunos5 sysv4 tandem ultrix unicos7 unicos8 unixware1 unixware2"
@echo " uts215 uxp"
@echo
@echo "If none of these match your environment, edit the system"
@echo "dependencies sections in the Makefile and do a 'make other'."
@echo
#######################################################
# Choice between easy and advanced installation recipe.
#
# Advanced installation: vendor-provided daemons are left alone, and the
# inetd configuration file is edited. In this case, the REAL_DAEMON_DIR
# macro should reflect the actual directory with (most of) your
# vendor-provided network daemons. These names can be found in the
# inetd.conf file. Usually, the telnet, ftp and finger daemons all live
# in the same directory.
#
# Uncomment the appropriate line if you are going to edit inetd.conf.
#
# Ultrix 4.x SunOS 4.x ConvexOS 10.x Dynix/ptx
#REAL_DAEMON_DIR=/usr/etc
#
# SysV.4 Solaris 2.x OSF AIX
#REAL_DAEMON_DIR=/usr/sbin
#
# BSD 4.4
#REAL_DAEMON_DIR=/usr/libexec
#
# HP-UX SCO Unicos
#REAL_DAEMON_DIR=/etc
# Easy installation: vendor-provided network daemons are moved to "some
# other" directory, and the tcpd wrapper fills in the "holes". For this
# mode of operation, the REAL_DAEMON_DIR macro should be set to the "some
# other" directory. The "..." is here for historical reasons only; you
# should probably use some other name.
#
# Uncomment the appropriate line if you are going to move your daemons.
#
# Ultrix 4.x SunOS 4.x ConvexOS 10.x Dynix/ptx
#REAL_DAEMON_DIR=/usr/etc/...
#
# SysV.4 Solaris 2.x OSF AIX
#REAL_DAEMON_DIR=/usr/sbin/...
#
# BSD 4.4
#REAL_DAEMON_DIR=/usr/libexec/...
#
# HP-UX SCO Unicos
#REAL_DAEMON_DIR=/etc/...
# End of mandatory section
##########################
##########################################
# Ready-to-use system-dependent templates.
#
# Ready-to-use templates are available for many systems (see the "echo"
# commands at the start of this Makefile). The templates take care of
# all system dependencies: after editing the REAL_DAEMON_DIR definition
# above, do a "make sunos4" (or whatever system type is appropriate).
#
# If your system is not listed (or something that comes close enough), you
# have to edit the system dependencies section below and do a "make other".
#
# Send templates for other UNIX versions to wietse@wzv.win.tue.nl.
# This is good for many BSD+SYSV hybrids with NIS (formerly YP).
generic aix osf alpha dynix:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ=setenv.o \
NETGROUP=-DNETGROUP TLI= all
# Ditto, with vsyslog
sunos4:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ=setenv.o \
NETGROUP=-DNETGROUP VSYSLOG= TLI= all
# Generic with resolver library.
generic-resolver:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS=-lresolv RANLIB=ranlib ARFLAGS=rv AUX_OBJ=setenv.o \
NETGROUP=-DNETGROUP TLI= all
# The NeXT loader needs "-m" or it barfs on redefined library functions.
next:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS=-m RANLIB=ranlib ARFLAGS=rv AUX_OBJ=environ.o \
NETGROUP=-DNETGROUP TLI= all
# SunOS for the 386 was frozen at release 4.0.x.
sunos40:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ="setenv.o strcasecmp.o" \
NETGROUP=-DNETGROUP VSYSLOG= TLI= all
# Ultrix is like aix, next, etc., but has miscd and setenv().
ultrix:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ= \
NETGROUP=-DNETGROUP TLI= all miscd
# This works on EP/IX 1.4.3 and will likely work on Mips (reggers@julian.uwo.ca)
epix:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ=environ.o \
NETGROUP=-DNETGROUP TLI= SYSTYPE="-systype bsd43" all
# Freebsd and linux by default have no NIS.
386bsd netbsd bsdos:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ= NETGROUP= TLI= \
EXTRA_CFLAGS=-DSYS_ERRLIST_DEFINED VSYSLOG= all
freebsd:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ= NETGROUP= TLI= \
EXTRA_CFLAGS=-DSYS_ERRLIST_DEFINED VSYSLOG= all
linux:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ=setenv.o \
NETGROUP= TLI= EXTRA_CFLAGS="-DBROKEN_SO_LINGER" all
# This is good for many SYSV+BSD hybrids with NIS, probably also for HP-UX 7.x.
hpux hpux8 hpux9 hpux10:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=echo ARFLAGS=rv AUX_OBJ=setenv.o \
NETGROUP=-DNETGROUP TLI= all
# ConvexOS-10.x with UltraNet support (ukkonen@csc.fi).
convex-ultranet:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS=-lulsock RANLIB=ranlib ARFLAGS=rv AUX_OBJ=environ.o \
NETGROUP=-DNETGROUP TLI= all
# Generic support for the Dynix/PTX version of TLI.
ptx-generic:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket -linet -lnsl" RANLIB=echo ARFLAGS=rv \
AUX_OBJ="setenv.o strcasecmp.o ptx.o" NETGROUP= TLI=-DPTX all
# With UDP support optimized for PTX 2.x (timw@sequent.com).
ptx-2.x:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket -linet -lnsl" RANLIB=echo ARFLAGS=rv \
AUX_OBJ="setenv.o strcasecmp.o tli-sequent.o" NETGROUP= \
TLI=-DTLI_SEQUENT all
# IRIX 4.0.x has a special ar(1) flag.
irix4:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lc -lsun" RANLIB=echo ARFLAGS=rvs AUX_OBJ=setenv.o \
NETGROUP=-DNETGROUP TLI= all
# IRIX 5.2 is SYSV4 with several broken things (such as -lsocket -lnsl).
irix5:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS=-lsun RANLIB=echo ARFLAGS=rv VSYSLOG= \
NETGROUP=-DNETGROUP AUX_OBJ=setenv.o TLI= all
# IRIX 6.2 (tucker@math.unc.edu). Must find a better value than 200000.
irix6:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=echo ARFLAGS=rv VSYSLOG= \
NETGROUP=-DNETGROUP EXTRA_CFLAGS="-DBSD=200000" TLI= all
# SunOS 5.x is another SYSV4 variant.
sunos5:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket -lnsl" RANLIB=echo ARFLAGS=rv VSYSLOG= \
NETGROUP=-DNETGROUP AUX_OBJ=setenv.o TLI=-DTLI \
BUGS="$(BUGS) -DSOLARIS_24_GETHOSTBYNAME_BUG" all
# Generic SYSV40
esix sysv4:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket -lnsl" RANLIB=echo ARFLAGS=rv \
NETGROUP=-DNETGROUP AUX_OBJ=setenv.o TLI=-DTLI all
# DG/UX 5.4.1 and 5.4.2 have an unusual inet_addr() interface.
dgux:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS=-lnsl RANLIB=echo ARFLAGS=rv \
NETGROUP=-DNETGROUP AUX_OBJ=setenv.o TLI=-DTLI \
BUGS="$(BUGS) -DINET_ADDR_BUG" all
dgux543:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS=-lnsl RANLIB=echo ARFLAGS=rv \
NETGROUP=-DNETGROUP AUX_OBJ=setenv.o TLI=-DTLI all
# NCR UNIX 02.02.01 and 02.03.00 (Alex Chircop, msu@unimt.mt)
ncrsvr4:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lresolv -lnsl -lsocket" RANLIB=echo ARFLAGS=rv \
AUX_OBJ="setenv.o strcasecmp.o" NETGROUP= TLI=-DTLI \
EXTRA_CFLAGS="" FROM_OBJ=ncr.o all
# Tandem SYSV4 (eqawas@hedgehog.ac.cowan.edu.au)
tandem:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket -lnsl" RANLIB=echo ARFLAGS=rv \
NETGROUP= AUX_OBJ="setenv.o strcasecmp.o" TLI=-DTLI all
# Amdahl UTS 2.1.5 (Richard.Richmond@bridge.bst.bls.com)
uts215:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket" RANLIB=echo \
ARFLAGS=rv AUX_OBJ=setenv.o NETGROUP=-DNO_NETGROUP TLI= all
# UXP/DS System V.4 clone (vic@uida0.uida.es).
uxp:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-L/usr/ucblib -lsocket -lnsl -lucb" \
RANLIB=echo ARFLAGS=rv NETGROUP=-DNETGROUP \
AUX_OBJ=setenv.o TLI="-DTLI -DDRS_XTI" all
# DELL System V.4 Issue 2.2 using gcc (kim@tac.nyc.ny.us, jurban@norden1.com)
dell-gcc:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket -lnsl" RANLIB=ranlib ARFLAGS=rv CC=gcc \
AUX_OBJ="setenv.o strcasecmp.o" TLI=-DTLI all
# SCO 3.2v4.1 no frills (jedwards@sol1.solinet.net).
sco:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket -lnsl_s" RANLIB=echo ARFLAGS=rv \
NETGROUP= AUX_OBJ=setenv.o TLI= all
# SCO OpenDesktop 2.0, release 3.2 (peter@midnight.com). Please simplify.
sco-od2:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lrpcsvc -lrpc -lyp -lrpc -lrpcsvc -lsocket" \
RANLIB=echo ARFLAGS=rv AUX_OBJ=setenv.o \
NETGROUP=-DNETGROUP TLI= all
# SCO 3.2v4.2 with TCP/IP 1.2.1 (Eduard.Vopicka@vse.cz). Please simplify.
sco-nis:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lyp -lrpc -lsocket -lyp -lc_s -lc" \
RANLIB=echo ARFLAGS=rv AUX_OBJ=setenv.o \
NETGROUP=-DNETGROUP TLI= EXTRA_CFLAGS="-nointl -DNO_NETGRENT" all
# SCO 3.2v5.0.0 OpenServer 5 (bob@odt.handy.com, bill@razorlogic.com)
sco-os5:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lrpcsvc -lsocket" RANLIB=echo ARFLAGS=rv VSYSLOG= \
AUX_OBJ=setenv.o NETGROUP=-DNETGROUP TLI= all
# sinix 5.42 setjmp workaround (szrzs023@ub3.ub.uni-kiel.de)
sinix:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket -lnsl -L/usr/ccs/lib -lc -L/usr/ucblib -lucb" \
RANLIB=echo ARFLAGS=rv AUX_OBJ=setenv.o TLI=-DTLI all
# Domain SR10.4. Build under bsd, run under either sysv3 or bsd43.
apollo:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ=setenv.o \
NETGROUP=-DNETGROUP TLI= SYSTYPE="-A run,any -A sys,any" all
# Pyramid OSx 5.1, using the BSD universe.
pyramid:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ="environ.o vfprintf.o" \
STRINGS="-Dstrchr=index -Dstrrchr=rindex -Dmemcmp=bcmp -Dno_memcpy" \
NETGROUP="-DNETGROUP -DUSE_GETDOMAIN" TLI= all
# Untested.
mips:
@echo "Warning: some definitions may be wrong."
make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ=environ.o \
NETGROUP=-DNETGROUP TLI= SYSTYPE="-sysname bsd43" all
# Cray (tested with UNICOS 7.0.4).
unicos7:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS=-lnet RANLIB=echo ARFLAGS=rv \
EXTRA_CFLAGS=-DINADDR_NONE="\"((unsigned long) -1)\"" \
AUX_OBJ="setenv.o strcasecmp.o" NETGROUP= TLI= all
# Unicos 8.x, Cray-YMP (Bruce Kelly).
unicos8:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=echo AR=bld ARFLAGS=rv \
AUX_OBJ= NETGROUP= TLI= all
# Power_UNIX 2.1.1 (amantel@lerc.nasa.gov)
power_unix_211:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lnsl -lsocket -lgen -lresolv" RANLIB=echo ARFLAGS=rv \
NETGROUP= AUX_OBJ=setenv.o TLI=-DTLI BUGS="$(BUGS)" all
# ISC (fc@all.net)
isc:
make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-linet -lnsl_s -ldbm" RANLIB=echo ARFLAGS=rv \
AUX_OBJ="setenv.o strcasecmp.o" EXTRA_CFLAGS="-DENOTCONN=ENAVAIL" \
NETGROUP= TLI= all
# Interactive UNIX R3.2 version 4.0 (Bobby D. Wright).
iunix:
make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-linet -lnsl_s -ldbm" RANLIB=echo ARFLAGS=rv \
AUX_OBJ=environ.o strcasecmp.o NETGROUP= TLI= all
# RTU 6.0 on a Masscomp 5400 (ben@piglet.cr.usgs.gov). When using the
# advanced installation, increment argv before actually looking at it.
rtu:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ=environ.o \
NETGROUP= TLI= all
# Unixware sans NIS (mc@telebase.com). Compiler dislikes strcasecmp.c.
unixware1:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket -lnsl -lc -L/usr/ucblib -lucb" RANLIB=echo ARFLAGS=rv \
NETGROUP=$(NETGROUP) AUX_OBJ=environ.o TLI=-DTLI all
unixware2:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket -lnsl -lgen -lc -L/usr/ucblib -lucb" RANLIB=echo \
ARFLAGS=rv NETGROUP=$(NETGROUP) AUX_OBJ=environ.o TLI=-DTLI all
u6000:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS="-lsocket -lnsl" RANLIB=echo ARFLAGS=rv \
NETGROUP=-DNETGROUP AUX_OBJ="setenv.o strcasecmp.o" TLI=-DTLI all
# MachTen
machten:
@make REAL_DAEMON_DIR=$(REAL_DAEMON_DIR) STYLE=$(STYLE) \
LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ=environ.o \
NETGROUP= TLI= all
###############################################################
# System dependencies: TLI (transport-level interface) support.
#
# Uncomment the following macro if your system has System V.4-style TLI
# support (/usr/include/sys/timod.h, /etc/netconfig, and the netdir(3)
# routines).
#
#TLI = -DTLI
###############################################################################
# System dependencies: differences between ranlib(1) and ar(1) implementations.
#
# Some C compilers (Ultrix 4.x) insist that ranlib(1) be run on an object
# library; some don't care as long as the modules are in the right order;
# some systems don't even have a ranlib(1) command. Make your choice.
RANLIB = ranlib # have ranlib (BSD-ish UNIX)
#RANLIB = echo # no ranlib (SYSV-ish UNIX)
ARFLAGS = rv # most systems
#ARFLAGS= rvs # IRIX 4.0.x
AR = ar
#AR = bld # Unicos 8.x
#############################################################################
# System dependencies: routines that are not present in the system libraries.
#
# If your system library does not have set/putenv() or strcasecmp(), use
# the ones provided with this source distribution. The environ.c module
# implements setenv(), getenv(), and putenv().
AUX_OBJ= setenv.o
#AUX_OBJ= environ.o
#AUX_OBJ= environ.o strcasecmp.o
# Uncomment the following if your C library does not provide the
# strchr/strrchr/memcmp routines, but comes with index/rindex/bcmp.
#
#STRINGS= -Dstrchr=index -Dstrrchr=rindex -Dmemcmp=bcmp -Dno_memcpy
#################################################################
# System dependencies: selection of non-default object libraries.
#
# Most System V implementations require that you explicitly specify the
# networking libraries. There is no general consensus, though.
#
#LIBS = -lsocket -lnsl # SysV.4 Solaris 2.x
#LIBS = -lsun # IRIX
#LIBS = -lsocket -linet -lnsl -lnfs # PTX
#LIBS = -linet -lnsl_s -ldbm # ISC
#LIBS = -lnet # Unicos 7
#LIBS = -linet -lsyslog -ldbm
#LIBS = -lsyslog -lsocket -lnsl
######################################################
# System dependencies: system-specific compiler flags.
#
# Apollo Domain/OS offers both bsd and sys5 environments, sometimes
# on the same machine. If your Apollo is primarily sys5.3 and also
# has bsd4.3, uncomment the following to build under bsd and run under
# either environment.
#
#SYSTYPE= -A run,any -A sys,any
# For MIPS RISC/os 4_52.p3, uncomment the following definition.
#
#SYSTYPE= -sysname bsd43
##################################################
# System dependencies: working around system bugs.
#
# -DGETPEERNAME_BUG works around a getpeername(2) bug in some versions of
# Apollo or SYSV.4 UNIX: the wrapper would report that all UDP requests
# come from address 0.0.0.0. The workaround does no harm on other systems.
#
# -DBROKEN_FGETS works around an fgets(3) bug in some System V versions
# (IRIX): fgets() gives up too fast when reading from a network socket.
# The workaround does no harm on other systems.
#
# Some UNIX systems (IRIX) make the error of calling the strtok() library
# routine from other library routines such as, e.g., gethostbyname/addr().
# The result is that hosts can slip through the wrapper allow/deny filters.
# Compile with -DLIBC_CALLS_STRTOK to avoid the vendor's strtok() routine.
# The workaround does no harm on other systems.
#
# DG/UX 5.4.1 comes with an inet_ntoa() function that returns a structure
# instead of a long integer. Compile with -DINET_ADDR_BUG to work around
# this mutant behavour. Fixed in 5.4R3.
#
# Solaris 2.4 gethostbyname(), in DNS through NIS mode, puts only one
# address in the host address list; all other addresses are treated as
# host name aliases. Compile with -DSOLARIS_24_GETHOSTBYNAME_BUG to work
# around this. The workaround does no harm on other Solaris versions.
BUGS = -DGETPEERNAME_BUG -DBROKEN_FGETS -DLIBC_CALLS_STRTOK
#BUGS = -DGETPEERNAME_BUG -DBROKEN_FGETS -DINET_ADDR_BUG
#BUGS = -DGETPEERNAME_BUG -DBROKEN_FGETS -DSOLARIS_24_GETHOSTBYNAME_BUG
##########################################################################
# System dependencies: whether or not your system has NIS (or YP) support.
#
# If your system supports NIS or YP-style netgroups, enable the following
# macro definition. Netgroups are used only for host access control.
#
#NETGROUP= -DNETGROUP
###############################################################
# System dependencies: whether or not your system has vsyslog()
#
# If your system supports vsyslog(), comment out the following definition.
# If in doubt leave it in, it won't harm.
VSYSLOG = -Dvsyslog=myvsyslog
# End of the system dependencies.
#################################
##############################
# Start of the optional stuff.
###########################################
# Optional: Turning on language extensions
#
# Instead of the default access control language that is documented in
# the hosts_access.5 document, the wrappers can be configured to
# implement an extensible language documented in the hosts_options.5
# document. This language is implemented by the "options.c" source
# module, which also gives hints on how to add your own extensions.
# Uncomment the next definition to turn on the language extensions
# (examples: allow, deny, banners, twist and spawn).
#
#STYLE = -DPROCESS_OPTIONS # Enable language extensions.
################################################################
# Optional: Changing the default disposition of logfile records
#
# By default, logfile entries are written to the same file as used for
# sendmail transaction logs. See your /etc/syslog.conf file for actual
# path names of logfiles. The tutorial section in the README file
# gives a brief introduction to the syslog daemon.
#
# Change the FACILITY definition below if you disagree with the default
# disposition. Some syslog versions (including Ultrix 4.x) do not provide
# this flexibility.
#
# If nothing shows up on your system, it may be that the syslog records
# are sent to a dedicated loghost. It may also be that no syslog daemon
# is running at all. The README file gives pointers to surrogate syslog
# implementations for systems that have no syslog library routines or
# no syslog daemons. When changing the syslog.conf file, remember that
# there must be TABs between fields.
#
# The LOG_XXX names below are taken from the /usr/include/syslog.h file.
FACILITY= LOG_MAIL # LOG_MAIL is what most sendmail daemons use
# The syslog priority at which successful connections are logged.
SEVERITY= LOG_INFO # LOG_INFO is normally not logged to the console
###########################
# Optional: Reduce DNS load
#
# When looking up the address for a host.domain name, the typical DNS
# code will first append substrings of your own domain, so it tries
# host.domain.your.own.domain, then host.domain.own.domain, and then
# host.domain. The APPEND_DOT feature stops this waste of cycles. It is
# off by default because it causes problems on sites that don't use DNS
# and with Solaris < 2.4. APPEND_DOT will not work with hostnames taken
# from /etc/hosts or from NIS maps. It does work with DNS through NIS.
#
# DOT= -DAPPEND_DOT
##################################################
# Optional: Always attempt remote username lookups
#
# By default, the wrappers look up the remote username only when the
# access control rules require them to do so.
#
# Username lookups require that the remote host runs a daemon that
# supports an RFC 931 like protocol. Remote user name lookups are not
# possible for UDP-based connections, and can cause noticeable delays
# with connections from non-UNIX PCs. On some systems, remote username
# lookups can trigger a kernel bug, causing loss of service. The README
# file describes how to find out if your UNIX kernel has that problem.
#
# Uncomment the following definition if the wrappers should always
# attempt to get the remote user name. If this is not enabled you can
# still do selective username lookups as documented in the hosts_access.5
# and hosts_options.5 manual pages (`nroff -man' format).
#
#AUTH = -DALWAYS_RFC931
#
# The default username lookup timeout is 10 seconds. This may not be long
# enough for slow hosts or networks, but is enough to irritate PC users.
RFC931_TIMEOUT = 10
######################################################
# Optional: Changing the default file protection mask
#
# On many systems, network daemons and other system processes are started
# with a zero umask value, so that world-writable files may be produced.
# It is a good idea to edit your /etc/rc* files so that they begin with
# an explicit umask setting. On our site we use `umask 022' because it
# does not break anything yet gives adequate protection against tampering.
#
# The following macro specifies the default umask for processes run under
# control of the daemon wrappers. Comment it out only if you are certain
# that inetd and its children are started with a safe umask value.
UMASK = -DDAEMON_UMASK=022
#######################################
# Optional: Turning off access control
#
# By default, host access control is enabled. To disable host access
# control, comment out the following definition. Host access control
# can also be turned off at runtime by providing no or empty access
# control tables.
ACCESS = -DHOSTS_ACCESS
########################################################
# Optional: Changing the access control table pathnames
#
# The HOSTS_ALLOW and HOSTS_DENY macros define where the programs will
# look for access control information. Watch out for the quotes and
# backslashes when you make changes.
TABLES = -DHOSTS_DENY=\"/etc/hosts.deny\" -DHOSTS_ALLOW=\"/etc/hosts.allow\"
####################################################
# Optional: dealing with host name/address conflicts
#
# By default, the software tries to protect against hosts that claim to
# have someone elses host name. This is relevant for network services
# whose authentication depends on host names, such as rsh and rlogin.
#
# With paranoid mode on, connections will be rejected when the host name
# does not match the host address. Connections will also be rejected when
# the host name is available but cannot be verified.
#
# Comment out the following definition if you want more control over such
# requests. When paranoid mode is off and a host name double check fails,
# the client can be matched with the PARANOID access control pattern.
#
# Paranoid mode implies hostname lookup. In order to disable hostname
# lookups altogether, see the next section.
PARANOID= -DPARANOID
########################################
# Optional: turning off hostname lookups
#
# By default, the software always attempts to look up the client
# hostname. With selective hostname lookups, the client hostname
# lookup is postponed until the name is required by an access control
# rule or by a %letter expansion.
#
# In order to perform selective hostname lookups, disable paranoid
# mode (see previous section) and comment out the following definition.
HOSTNAME= -DALWAYS_HOSTNAME
#############################################
# Optional: Turning on host ADDRESS checking
#
# Optionally, the software tries to protect against hosts that pretend to
# have someone elses host address. This is relevant for network services
# whose authentication depends on host names, such as rsh and rlogin,
# because the network address is used to look up the remote host name.
#
# The protection is to refuse TCP connections with IP source routing
# options.
#
# This feature cannot be used with SunOS 4.x because of a kernel bug in
# the implementation of the getsockopt() system call. Kernel panics have
# been observed for SunOS 4.1.[1-3]. Symptoms are "BAD TRAP" and "Data
# fault" while executing the tcp_ctloutput() kernel function.
#
# Reportedly, Sun patch 100804-03 or 101790 fixes this for SunOS 4.1.x.
#
# Uncomment the following macro definition if your getsockopt() is OK.
#
# -DKILL_IP_OPTIONS is not needed on modern UNIX systems that can stop
# source-routed traffic in the kernel. Examples: 4.4BSD derivatives,
# Solaris 2.x, and Linux. See your system documentation for details.
#
# KILL_OPT= -DKILL_IP_OPTIONS
## End configuration options
############################
# Protection against weird shells or weird make programs.
SHELL = /bin/sh
.c.o:; $(CC) $(CFLAGS) -c $*.c
CFLAGS = -O -DFACILITY=$(FACILITY) $(ACCESS) $(PARANOID) $(NETGROUP) \
$(BUGS) $(SYSTYPE) $(AUTH) $(UMASK) \
-DREAL_DAEMON_DIR=\"$(REAL_DAEMON_DIR)\" $(STYLE) $(KILL_OPT) \
-DSEVERITY=$(SEVERITY) -DRFC931_TIMEOUT=$(RFC931_TIMEOUT) \
$(UCHAR) $(TABLES) $(STRINGS) $(TLI) $(EXTRA_CFLAGS) $(DOT) \
$(VSYSLOG) $(HOSTNAME)
LIB_OBJ= hosts_access.o options.o shell_cmd.o rfc931.o eval.o \
hosts_ctl.o refuse.o percent_x.o clean_exit.o $(AUX_OBJ) \
$(FROM_OBJ) fix_options.o socket.o tli.o workarounds.o \
update.o misc.o diag.o percent_m.o myvsyslog.o
FROM_OBJ= fromhost.o
KIT = README miscd.c tcpd.c fromhost.c hosts_access.c shell_cmd.c \
tcpd.h tcpdmatch.c Makefile hosts_access.5 strcasecmp.c BLURB rfc931.c \
tcpd.8 eval.c hosts_access.3 hosts_ctl.c percent_x.c options.c \
clean_exit.c environ.c patchlevel.h fix_options.c workarounds.c \
socket.c tli.c DISCLAIMER fakelog.c safe_finger.c hosts_options.5 \
CHANGES try-from.c update.c ptx.c vfprintf.c tli-sequent.c \
tli-sequent.h misc.c diag.c ncr.c tcpdchk.c percent_m.c \
myvsyslog.c mystdarg.h printf.ck README.IRIX Banners.Makefile \
refuse.c tcpdchk.8 setenv.c inetcf.c inetcf.h scaffold.c \
scaffold.h tcpdmatch.8 README.NIS
LIB = libwrap.a
all other: config-check tcpd tcpdmatch try-from safe_finger tcpdchk
# Invalidate all object files when the compiler options (CFLAGS) have changed.
config-check:
@set +e; test -n "$(REAL_DAEMON_DIR)" || { make; exit 1; }
@set +e; echo $(CFLAGS) >/tmp/cflags.$$$$ ; \
if cmp cflags /tmp/cflags.$$$$ ; \
then rm /tmp/cflags.$$$$ ; \
else mv /tmp/cflags.$$$$ cflags ; \
fi >/dev/null 2>/dev/null
$(LIB): $(LIB_OBJ)
rm -f $(LIB)
$(AR) $(ARFLAGS) $(LIB) $(LIB_OBJ)
-$(RANLIB) $(LIB)
tcpd: tcpd.o $(LIB)
$(CC) $(CFLAGS) -o $@ tcpd.o $(LIB) $(LIBS)
miscd: miscd.o $(LIB)
$(CC) $(CFLAGS) -o $@ miscd.o $(LIB) $(LIBS)
safe_finger: safe_finger.o $(LIB)
$(CC) $(CFLAGS) -o $@ safe_finger.o $(LIB) $(LIBS)
TCPDMATCH_OBJ = tcpdmatch.o fakelog.o inetcf.o scaffold.o
tcpdmatch: $(TCPDMATCH_OBJ) $(LIB)
$(CC) $(CFLAGS) -o $@ $(TCPDMATCH_OBJ) $(LIB) $(LIBS)
try-from: try-from.o fakelog.o $(LIB)
$(CC) $(CFLAGS) -o $@ try-from.o fakelog.o $(LIB) $(LIBS)
TCPDCHK_OBJ = tcpdchk.o fakelog.o inetcf.o scaffold.o
tcpdchk: $(TCPDCHK_OBJ) $(LIB)
$(CC) $(CFLAGS) -o $@ $(TCPDCHK_OBJ) $(LIB) $(LIBS)
shar: $(KIT)
@shar $(KIT)
kit: $(KIT)
@makekit $(KIT)
files:
@echo $(KIT)
archive:
$(ARCHIVE) $(KIT)
clean:
rm -f tcpd miscd safe_finger tcpdmatch tcpdchk try-from *.[oa] core \
cflags
tidy: clean
chmod -R a+r .
chmod 755 .
# Enable all bells and whistles for linting.
lint: tcpd_lint miscd_lint match_lint chk_lint
tcpd_lint:
lint -DFACILITY=LOG_MAIL -DHOSTS_ACCESS -DPARANOID -DNETGROUP \
-DGETPEERNAME_BUG -DDAEMON_UMASK=022 -DSEVERITY=$(SEVERITY) \
$(TABLES) -DKILL_IP_OPTIONS -DPROCESS_OPTIONS \
-DRFC931_TIMEOUT=$(RFC931_TIMEOUT) -DALWAYS_RFC931 \
-DREAL_DAEMON_DIR=\"$(REAL_DAEMON_DIR)\" \
-Dvsyslog=myvsyslog \
tcpd.c fromhost.c socket.c tli.c hosts_access.c \
shell_cmd.c refuse.c rfc931.c eval.c percent_x.c clean_exit.c \
options.c setenv.c fix_options.c workarounds.c update.c misc.c \
diag.c myvsyslog.c percent_m.c
miscd_lint:
lint -DFACILITY=LOG_MAIL -DHOSTS_ACCESS -DPARANOID -DNETGROUP \
-DGETPEERNAME_BUG -DDAEMON_UMASK=022 -DSEVERITY=$(SEVERITY) \
$(TABLES) -DKILL_IP_OPTIONS -DPROCESS_OPTIONS \
-DRFC931_TIMEOUT=$(RFC931_TIMEOUT) -DALWAYS_RFC931 \
-DREAL_DAEMON_DIR=\"$(REAL_DAEMON_DIR)\" \
-Dvsyslog=myvsyslog \
miscd.c fromhost.c socket.c tli.c hosts_access.c \
shell_cmd.c refuse.c rfc931.c eval.c percent_x.c clean_exit.c \
options.c setenv.c fix_options.c workarounds.c update.c misc.c \
diag.c myvsyslog.c percent_m.c
match_lint:
lint -DFACILITY=LOG_MAIL -DSEVERITY=$(SEVERITY) -DHOSTS_ACCESS \
-DPARANOID $(TABLES) -DNETGROUP -DPROCESS_OPTIONS -DRFC931_TIMEOUT=10 \
-DREAL_DAEMON_DIR=\"$(REAL_DAEMON_DIR)\" \
-Dvsyslog=myvsyslog \
tcpdmatch.c hosts_access.c eval.c percent_x.c options.c workarounds.c \
update.c socket.c misc.c diag.c myvsyslog.c percent_m.c setenv.c \
inetcf.c scaffold.c
chk_lint:
lint -DFACILITY=LOG_MAIL -DSEVERITY=$(SEVERITY) -DHOSTS_ACCESS \
-DPARANOID $(TABLES) -DNETGROUP -DPROCESS_OPTIONS -DRFC931_TIMEOUT=10 \
-DREAL_DAEMON_DIR=\"$(REAL_DAEMON_DIR)\" \
-Dvsyslog=myvsyslog \
tcpdchk.c eval.c percent_x.c options.c update.c workarounds.c \
setenv.c misc.c diag.c myvsyslog.c percent_m.c inetcf.c scaffold.c
printfck:
printfck -f printf.ck \
tcpd.c fromhost.c socket.c tli.c hosts_access.c \
shell_cmd.c refuse.c rfc931.c eval.c percent_x.c clean_exit.c \
options.c setenv.c fix_options.c workarounds.c update.c misc.c \
diag.c myvsyslog.c percent_m.c >aap.c
lint -DFACILITY=LOG_MAIL -DHOSTS_ACCESS -DPARANOID -DNETGROUP \
-DGETPEERNAME_BUG -DDAEMON_UMASK=022 -DSEVERITY=$(SEVERITY) \
$(TABLES) -DKILL_IP_OPTIONS -DPROCESS_OPTIONS \
-DRFC931_TIMEOUT=$(RFC931_TIMEOUT) -DALWAYS_RFC931 \
-DREAL_DAEMON_DIR=\"$(REAL_DAEMON_DIR)\" -Dvsyslog=myvsyslog aap.c
printfck -f printf.ck \
tcpdchk.c eval.c percent_x.c options.c update.c workarounds.c \
setenv.c misc.c diag.c myvsyslog.c percent_m.c inetcf.c scaffold.c \
>aap.c
lint -DFACILITY=LOG_MAIL -DSEVERITY=$(SEVERITY) -DHOSTS_ACCESS \
-DPARANOID $(TABLES) -DNETGROUP -DPROCESS_OPTIONS -DRFC931_TIMEOUT=10 \
-Dvsyslog=myvsyslog -DREAL_DAEMON_DIR=\"$(REAL_DAEMON_DIR)\"
# Internal compilation dependencies.
clean_exit.o: cflags
clean_exit.o: tcpd.h
diag.o: cflags
diag.o: mystdarg.h
diag.o: tcpd.h
environ.o: cflags
eval.o: cflags
eval.o: tcpd.h
fakelog.o: cflags
fakelog.o: mystdarg.h
fix_options.o: cflags
fix_options.o: tcpd.h
fromhost.o: cflags
fromhost.o: tcpd.h
hosts_access.o: cflags
hosts_access.o: tcpd.h
hosts_ctl.o: cflags
hosts_ctl.o: tcpd.h
inetcf.o: cflags
inetcf.o: inetcf.h
inetcf.o: tcpd.h
misc.o: cflags
misc.o: tcpd.h
miscd.o: cflags
miscd.o: patchlevel.h
miscd.o: tcpd.h
myvsyslog.o: cflags
myvsyslog.o: mystdarg.h
myvsyslog.o: tcpd.h
ncr.o: cflags
ncr.o: tcpd.h
options.o: cflags
options.o: tcpd.h
percent_m.o: cflags
percent_m.o: mystdarg.h
percent_x.o: cflags
percent_x.o: tcpd.h
ptx.o: cflags
ptx.o: tcpd.h
refuse.o: cflags
refuse.o: tcpd.h
rfc931.o: cflags
rfc931.o: tcpd.h
safe_finger.o: cflags
scaffold.o: cflags
scaffold.o: scaffold.h
scaffold.o: tcpd.h
setenv.o: cflags
shell_cmd.o: cflags
shell_cmd.o: tcpd.h
socket.o: cflags
socket.o: tcpd.h
strcasecmp.o: cflags
tcpd.o: cflags
tcpd.o: patchlevel.h
tcpd.o: tcpd.h
tcpdchk.o: cflags
tcpdchk.o: inetcf.h
tcpdchk.o: scaffold.h
tcpdchk.o: tcpd.h
tcpdmatch.o: cflags
tcpdmatch.o: scaffold.h
tcpdmatch.o: tcpd.h
tli-sequent.o: cflags
tli-sequent.o: tcpd.h
tli-sequent.o: tli-sequent.h
tli.o: cflags
tli.o: tcpd.h
try-from.o: cflags
try-from.o: tcpd.h
update.o: cflags
update.o: mystdarg.h
update.o: tcpd.h
vfprintf.o: cflags
workarounds.o: cflags
workarounds.o: tcpd.h

1038
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@(#) README.IRIX 1.2 94/12/28 18:45:58
In the past few months I received several messages with questions from
people that tried to use my tcp wrapper on IRIX 5.x. Some mysteries
could be solved via email, and then some remained.
Today I finally had a chance to do some tests on someones IRIX 5.2
system. Here is my first-hand experience with wrapper release 6.3.
(1) Inetd is broken. Normally one edits inetd.conf, sends a HUP signal
to inetd and that's it. With IRIX evil things happen: inetd is too
stupid to remember that it is already listening on a port.
In order to modify an entry in inetd.conf, first comment it out
with a # at the beginning of the line, kill -HUP the inetd, then
uncomment the inetd.conf entry and kill -HUP again.
Even with this amount of care I have seen inetd messing up, like
calling rusersd when I make a talk connection. Even killing and
restarting inetd does not solve all problems.
I find it hard to believe, it but the best thing to do with IRIX is
to reboot after changing inetd.conf.
(2) When tcpd is built according to the irix4 Makefile rules, it
appears to work as expected with TCP-based services such as
fingerd, and with UDP-based services such as ntalk and tftp.
(3) It does NOT work with RPC over UDP services such as rusersd and
rstatd: the wrapper hangs in the recvfrom() system call, and I
have spent several hours looking for ways to work around it. No
way. After finding that none of the applicable socket primitives
can be made to work (recvfrom recvmsg) I give up. So, the IRIX RPC
services cannot be wrapped until SGI fixes their system so that it
works like everyone elses code (HP Sun Dec AIX and so on).
(4) I didn't even bother to try the RPC over TCP services.
(5) When an IRIX 5.2 system is a NIS client, it can have problems with
hosts that have more than one address: the wrapper will see only
one address, and may complain when PARANOID mode is on. The fix is
to change the name service lookup order in /etc/resolv.conf so that
your system tries DNS before NIS (hostresorder bind nis local).
(6) IRIX 5.2 is not System V.4, and it shows. Do not link with the
-lsocket and -lnsl libraries. They are completely broken, and the
wrapper will be unable to figure out the client internet address.
So, TLI services cannot be wrapped until SGI fixes their system so
that it works the way it is supposed to.
I am not impressed by the quality of the IRIX system software. There
are many things that work on almost every other system except with IRIX.
Wietse

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@ -0,0 +1,207 @@
@(#) README.NIS 1.2 96/02/11 17:24:52
> Problem: I have several [machines] with multiple IP addresses, and
> when they try to connect to a daemon with tcp wrapper, they are often
> rejected. I assume this is due to the -DPARANOID option, and depends
> on which IP address is returned first from the nameserver for a given
> name. This behavior seems to be random, may depend on ordering in
> the YP host map?
[Note: the situation described below no longer exists. Presently, my
internet gateway uses the same IP address on all interfaces. To avoid
confusion I have removed the old name wzv-gw.win.tue.nl from the DNS. I
have kept the discussion below for educational reasons].
NIS was not designed to handle multi-homed hosts. With NIS, each
address should have its own hostname. For example, wzv-gw is my
gateway. It has two interfaces: one connected to the local ethernet,
the other to a serial link. In the NIS it is registered as:
131.155.210.23 wzv-gw-ether
131.155.12.78 wzv-gw-slip
In principle, wzv-gw could be the official name of one of these
interfaces, or it could be an alias for both.
The DNS was designed to handle multi-homed hosts. In the DNS my gateway
is registered in zone win.tue.nl, with one name that has two A records:
wzv-gw IN A 131.155.210.23
IN A 131.155.12.78
And of course there are PTR records in zones 210.155.131.in-addr.arpa
and 12.155.131.in-addr.arpa that point to wzv-gw.win.tue.nl.
This setup does not cause any problems. You can test your name service
with the two programs below. This is what they say on a local NIS client
(both client and server running SunOS 4.1.3_U1):
% gethostbyname wzv-gw
Hostname: wzv-gw.win.tue.nl
Aliases:
Addresses: 131.155.210.23 131.155.12.78
% gethostbyaddr 131.155.210.23
Hostname: wzv-gw-ether
Aliases:
Addresses: 131.155.210.23
% gethostbyaddr 131.155.12.78
Hostname: wzv-gw-slip
Aliases:
Addresses: 131.155.12.78
Things seem less confusing when seen by a NIS client in a different
domain (both client and server running SunOS 4.1.3_U1):
% gethostbyname wzv-gw.win.tue.nl
Hostname: wzv-gw.win.tue.nl
Aliases:
Addresses: 131.155.210.23 131.155.12.78
% gethostbyaddr 131.155.210.23
Hostname: wzv-gw.win.tue.nl
Aliases:
Addresses: 131.155.12.78 131.155.210.23
% gethostbyaddr 131.155.12.78
Hostname: wzv-gw.win.tue.nl
Aliases:
Addresses: 131.155.210.23 131.155.12.78
Alas, Solaris 2.4 still has problems. This is what I get on a Solaris
2.4 NIS client, with a SunOS 4.1.3_U1 NIS server:
% gethostbyname wzv-gw.win.tue.nl
Hostname: wzv-gw.win.tue.nl
Aliases: 131.155.210.23 wzv-gw.win.tue.nl
Addresses: 131.155.12.78
The tcpd source comes with a workaround for this problem. The
workaround is ugly and is not part of the programs attached below.
#! /bin/sh
# This is a shell archive. Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file". To overwrite existing
# files, type "sh file -c". You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g.. If this archive is complete, you
# will see the following message at the end:
# "End of shell archive."
# Contents: gethostbyaddr.c gethostbyname.c
# Wrapped by wietse@wzv on Sun Jan 8 17:08:48 1995
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f gethostbyaddr.c -a "${1}" != "-c" ; then
echo shar: Will not over-write existing file \"gethostbyaddr.c\"
else
echo shar: Extracting \"gethostbyaddr.c\" \(1073 characters\)
sed "s/^X//" >gethostbyaddr.c <<'END_OF_gethostbyaddr.c'
X /*
X * gethostbyaddr tester. compile with:
X *
X * cc -o gethostbyaddr gethostbyaddr.c (SunOS 4.x)
X *
X * cc -o gethostbyaddr gethostbyaddr.c -lnsl (SunOS 5.x)
X *
X * run as: gethostbyaddr address
X *
X * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
X */
X
X#include <sys/types.h>
X#include <sys/socket.h>
X#include <netinet/in.h>
X#include <arpa/inet.h>
X#include <netdb.h>
X#include <stdio.h>
X
Xmain(argc, argv)
Xint argc;
Xchar **argv;
X{
X struct hostent *hp;
X long addr;
X
X if (argc != 2) {
X fprintf(stderr, "usage: %s i.p.addres\n", argv[0]);
X exit(1);
X }
X addr = inet_addr(argv[1]);
X if (hp = gethostbyaddr((char *) &addr, sizeof(addr), AF_INET)) {
X printf("Hostname:\t%s\n", hp->h_name);
X printf("Aliases:\t");
X while (hp->h_aliases[0])
X printf("%s ", *hp->h_aliases++);
X printf("\n");
X printf("Addresses:\t");
X while (hp->h_addr_list[0])
X printf("%s ", inet_ntoa(*(struct in_addr *) * hp->h_addr_list++));
X printf("\n");
X exit(0);
X }
X fprintf(stderr, "host %s not found\n", argv[1]);
X exit(1);
X}
END_OF_gethostbyaddr.c
if test 1073 -ne `wc -c <gethostbyaddr.c`; then
echo shar: \"gethostbyaddr.c\" unpacked with wrong size!
fi
# end of overwriting check
fi
if test -f gethostbyname.c -a "${1}" != "-c" ; then
echo shar: Will not over-write existing file \"gethostbyname.c\"
else
echo shar: Extracting \"gethostbyname.c\" \(999 characters\)
sed "s/^X//" >gethostbyname.c <<'END_OF_gethostbyname.c'
X /*
X * gethostbyname tester. compile with:
X *
X * cc -o gethostbyname gethostbyname.c (SunOS 4.x)
X *
X * cc -o gethostbyname gethostbyname.c -lnsl (SunOS 5.x)
X *
X * run as: gethostbyname hostname
X *
X * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
X */
X#include <sys/types.h>
X#include <sys/socket.h>
X#include <netinet/in.h>
X#include <arpa/inet.h>
X#include <netdb.h>
X#include <stdio.h>
X
Xmain(argc, argv)
Xint argc;
Xchar **argv;
X{
X struct hostent *hp;
X
X if (argc != 2) {
X fprintf(stderr, "usage: %s hostname\n", argv[0]);
X exit(1);
X }
X if (hp = gethostbyname(argv[1])) {
X printf("Hostname:\t%s\n", hp->h_name);
X printf("Aliases:\t");
X while (hp->h_aliases[0])
X printf("%s ", *hp->h_aliases++);
X printf("\n");
X printf("Addresses:\t");
X while (hp->h_addr_list[0])
X printf("%s ", inet_ntoa(*(struct in_addr *) * hp->h_addr_list++));
X printf("\n");
X exit(0);
X } else {
X fprintf(stderr, "host %s not found\n", argv[1]);
X exit(1);
X }
X}
END_OF_gethostbyname.c
if test 999 -ne `wc -c <gethostbyname.c`; then
echo shar: \"gethostbyname.c\" unpacked with wrong size!
fi
# end of overwriting check
fi
echo shar: End of shell archive.
exit 0

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@ -0,0 +1,42 @@
/*
* clean_exit() cleans up and terminates the program. It should be called
* instead of exit() when for some reason the real network daemon will not or
* cannot be run. Reason: in the case of a datagram-oriented service we must
* discard the not-yet received data from the client. Otherwise, inetd will
* see the same datagram again and again, and go into a loop.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) clean_exit.c 1.4 94/12/28 17:42:19";
#endif
#include <stdio.h>
extern void exit();
#include "tcpd.h"
/* clean_exit - clean up and exit */
void clean_exit(request)
struct request_info *request;
{
/*
* In case of unconnected protocols we must eat up the not-yet received
* data or inetd will loop.
*/
if (request->sink)
request->sink(request->fd);
/*
* Be kind to the inetd. We already reported the problem via the syslogd,
* and there is no need for additional garbage in the logfile.
*/
sleep(5);
exit(0);
}

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/*
* Routines to report various classes of problems. Each report is decorated
* with the current context (file name and line number), if available.
*
* tcpd_warn() reports a problem and proceeds.
*
* tcpd_jump() reports a problem and jumps.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) diag.c 1.1 94/12/28 17:42:20";
#endif
/* System libraries */
#include <syslog.h>
#include <stdio.h>
#include <setjmp.h>
/* Local stuff */
#include "tcpd.h"
#include "mystdarg.h"
struct tcpd_context tcpd_context;
jmp_buf tcpd_buf;
/* tcpd_diag - centralize error reporter */
static void tcpd_diag(severity, tag, format, ap)
int severity;
char *tag;
char *format;
va_list ap;
{
char fmt[BUFSIZ];
if (tcpd_context.file)
sprintf(fmt, "%s: %s, line %d: %s",
tag, tcpd_context.file, tcpd_context.line, format);
else
sprintf(fmt, "%s: %s", tag, format);
vsyslog(severity, fmt, ap);
}
/* tcpd_warn - report problem of some sort and proceed */
void VARARGS(tcpd_warn, char *, format)
{
va_list ap;
VASTART(ap, char *, format);
tcpd_diag(LOG_ERR, "warning", format, ap);
VAEND(ap);
}
/* tcpd_jump - report serious problem and jump */
void VARARGS(tcpd_jump, char *, format)
{
va_list ap;
VASTART(ap, char *, format);
tcpd_diag(LOG_ERR, "error", format, ap);
VAEND(ap);
longjmp(tcpd_buf, AC_ERROR);
}

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@ -0,0 +1,224 @@
/*
* Many systems have putenv() but no setenv(). Other systems have setenv()
* but no putenv() (MIPS). Still other systems have neither (NeXT). This is a
* re-implementation that hopefully ends all problems.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) environ.c 1.2 94/03/23 16:09:46";
#endif
/* System libraries. */
extern char **environ;
extern char *strchr();
extern char *strcpy();
extern char *strncpy();
extern char *malloc();
extern char *realloc();
extern int strncmp();
extern void free();
#ifdef no_memcpy
#define memcpy(d,s,l) bcopy(s,d,l)
#else
extern char *memcpy();
#endif
/* Local stuff. */
static int addenv(); /* append entry to environment */
static int allocated = 0; /* environ is, or is not, allocated */
#define DO_CLOBBER 1
/* namelength - determine length of name in "name=whatever" */
static int namelength(name)
char *name;
{
char *equal;
equal = strchr(name, '=');
return ((equal == 0) ? strlen(name) : (equal - name));
}
/* findenv - given name, locate name=value */
static char **findenv(name, len)
char *name;
int len;
{
char **envp;
for (envp = environ; envp && *envp; envp++)
if (strncmp(name, *envp, len) == 0 && (*envp)[len] == '=')
return (envp);
return (0);
}
/* getenv - given name, locate value */
char *getenv(name)
char *name;
{
int len = namelength(name);
char **envp = findenv(name, len);
return (envp ? *envp + len + 1 : 0);
}
/* putenv - update or append environment (name,value) pair */
int putenv(nameval)
char *nameval;
{
char *equal = strchr(nameval, '=');
char *value = (equal ? equal : "");
return (setenv(nameval, value, DO_CLOBBER));
}
/* unsetenv - remove variable from environment */
void unsetenv(name)
char *name;
{
char **envp;
if ((envp = findenv(name, namelength(name))) != 0)
while (envp[0] = envp[1])
envp++;
}
/* setenv - update or append environment (name,value) pair */
int setenv(name, value, clobber)
char *name;
char *value;
int clobber;
{
char *destination;
char **envp;
int l_name; /* length of name part */
int l_nameval; /* length of name=value */
/* Permit name= and =value. */
l_name = namelength(name);
envp = findenv(name, l_name);
if (envp != 0 && clobber == 0)
return (0);
if (*value == '=')
value++;
l_nameval = l_name + strlen(value) + 1;
/*
* Use available memory if the old value is long enough. Never free an
* old name=value entry because it may not be allocated.
*/
destination = (envp != 0 && strlen(*envp) >= l_nameval) ?
*envp : malloc(l_nameval + 1);
if (destination == 0)
return (-1);
strncpy(destination, name, l_name);
destination[l_name] = '=';
strcpy(destination + l_name + 1, value);
return ((envp == 0) ? addenv(destination) : (*envp = destination, 0));
}
/* cmalloc - malloc and copy block of memory */
static char *cmalloc(new_len, old, old_len)
char *old;
int old_len;
{
char *new = malloc(new_len);
if (new != 0)
memcpy(new, old, old_len);
return (new);
}
/* addenv - append environment entry */
static int addenv(nameval)
char *nameval;
{
char **envp;
int n_used; /* number of environment entries */
int l_used; /* bytes used excl. terminator */
int l_need; /* bytes needed incl. terminator */
for (envp = environ; envp && *envp; envp++)
/* void */ ;
n_used = envp - environ;
l_used = n_used * sizeof(*envp);
l_need = l_used + 2 * sizeof(*envp);
envp = allocated ?
(char **) realloc((char *) environ, l_need) :
(char **) cmalloc(l_need, (char *) environ, l_used);
if (envp == 0) {
return (-1);
} else {
allocated = 1;
environ = envp;
environ[n_used++] = nameval; /* add new entry */
environ[n_used] = 0; /* terminate list */
return (0);
}
}
#ifdef TEST
/*
* Stand-alone program for test purposes.
*/
/* printenv - display environment */
static void printenv()
{
char **envp;
for (envp = environ; envp && *envp; envp++)
printf("%s\n", *envp);
}
int main(argc, argv)
int argc;
char **argv;
{
char *cp;
int changed = 0;
if (argc < 2) {
printf("usage: %s name[=value]...\n", argv[0]);
return (1);
}
while (--argc && *++argv) {
if (argv[0][0] == '-') { /* unsetenv() test */
unsetenv(argv[0] + 1);
changed = 1;
} else if (strchr(argv[0], '=') == 0) { /* getenv() test */
cp = getenv(argv[0]);
printf("%s: %s\n", argv[0], cp ? cp : "not found");
} else { /* putenv() test */
if (putenv(argv[0])) {
perror("putenv");
return (1);
}
changed = 1;
}
}
if (changed)
printenv();
return (0);
}
#endif /* TEST */

136
contrib/tcp_wrappers/eval.c Normal file
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/*
* Routines for controlled evaluation of host names, user names, and so on.
* They are, in fact, wrappers around the functions that are specific for
* the sockets or TLI programming interfaces. The request_info and host_info
* structures are used for result cacheing.
*
* These routines allows us to postpone expensive operations until their
* results are really needed. Examples are hostname lookups and double
* checks, or username lookups. Information that cannot be retrieved is
* given the value "unknown" ("paranoid" in case of hostname problems).
*
* When ALWAYS_HOSTNAME is off, hostname lookup is done only when required by
* tcpd paranoid mode, by access control patterns, or by %letter expansions.
*
* When ALWAYS_RFC931 mode is off, user lookup is done only when required by
* access control patterns or %letter expansions.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) eval.c 1.3 95/01/30 19:51:45";
#endif
/* System libraries. */
#include <stdio.h>
#include <string.h>
/* Local stuff. */
#include "tcpd.h"
/*
* When a string has the value STRING_UNKNOWN, it means: don't bother, I
* tried to look up the data but it was unavailable for some reason. When a
* host name has the value STRING_PARANOID it means there was a name/address
* conflict.
*/
char unknown[] = STRING_UNKNOWN;
char paranoid[] = STRING_PARANOID;
/* eval_user - look up user name */
char *eval_user(request)
struct request_info *request;
{
if (request->user[0] == 0) {
strcpy(request->user, unknown);
if (request->sink == 0 && request->client->sin && request->server->sin)
rfc931(request->client->sin, request->server->sin, request->user);
}
return (request->user);
}
/* eval_hostaddr - look up printable address */
char *eval_hostaddr(host)
struct host_info *host;
{
if (host->addr[0] == 0) {
strcpy(host->addr, unknown);
if (host->request->hostaddr != 0)
host->request->hostaddr(host);
}
return (host->addr);
}
/* eval_hostname - look up host name */
char *eval_hostname(host)
struct host_info *host;
{
if (host->name[0] == 0) {
strcpy(host->name, unknown);
if (host->request->hostname != 0)
host->request->hostname(host);
}
return (host->name);
}
/* eval_hostinfo - return string with host name (preferred) or address */
char *eval_hostinfo(host)
struct host_info *host;
{
char *hostname;
#ifndef ALWAYS_HOSTNAME /* no implicit host lookups */
if (host->name[0] == 0)
return (eval_hostaddr(host));
#endif
hostname = eval_hostname(host);
if (HOSTNAME_KNOWN(hostname)) {
return (host->name);
} else {
return (eval_hostaddr(host));
}
}
/* eval_client - return string with as much about the client as we know */
char *eval_client(request)
struct request_info *request;
{
static char both[2 * STRING_LENGTH];
char *hostinfo = eval_hostinfo(request->client);
#ifndef ALWAYS_RFC931 /* no implicit user lookups */
if (request->user[0] == 0)
return (hostinfo);
#endif
if (STR_NE(eval_user(request), unknown)) {
sprintf(both, "%s@%s", request->user, hostinfo);
return (both);
} else {
return (hostinfo);
}
}
/* eval_server - return string with as much about the server as we know */
char *eval_server(request)
struct request_info *request;
{
static char both[2 * STRING_LENGTH];
char *host = eval_hostinfo(request->server);
char *daemon = eval_daemon(request);
if (STR_NE(host, unknown)) {
sprintf(both, "%s@%s", daemon, host);
return (both);
} else {
return (daemon);
}
}

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@ -0,0 +1,62 @@
/*
* This module intercepts syslog() library calls and redirects their output
* to the standard output stream. For interactive testing.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) fakelog.c 1.3 94/12/28 17:42:21";
#endif
#include <stdio.h>
#include "mystdarg.h"
/* openlog - dummy */
/* ARGSUSED */
openlog(name, logopt, facility)
char *name;
int logopt;
int facility;
{
/* void */
}
/* vsyslog - format one record */
vsyslog(severity, fmt, ap)
int severity;
char *fmt;
va_list ap;
{
char buf[BUFSIZ];
vprintf(percent_m(buf, fmt), ap);
printf("\n");
fflush(stdout);
}
/* syslog - format one record */
/* VARARGS */
VARARGS(syslog, int, severity)
{
va_list ap;
char *fmt;
VASTART(ap, int, severity);
fmt = va_arg(ap, char *);
vsyslog(severity, fmt, ap);
VAEND(ap);
}
/* closelog - dummy */
closelog()
{
/* void */
}

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@ -0,0 +1,109 @@
/*
* Routine to disable IP-level socket options. This code was taken from 4.4BSD
* rlogind and kernel source, but all mistakes in it are my fault.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) fix_options.c 1.6 97/04/08 02:29:19";
#endif
#include <sys/types.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netdb.h>
#include <stdio.h>
#include <syslog.h>
#ifndef IPOPT_OPTVAL
#define IPOPT_OPTVAL 0
#define IPOPT_OLEN 1
#endif
#include "tcpd.h"
#define BUFFER_SIZE 512 /* Was: BUFSIZ */
/* fix_options - get rid of IP-level socket options */
fix_options(request)
struct request_info *request;
{
#ifdef IP_OPTIONS
unsigned char optbuf[BUFFER_SIZE / 3], *cp;
char lbuf[BUFFER_SIZE], *lp;
int optsize = sizeof(optbuf), ipproto;
struct protoent *ip;
int fd = request->fd;
unsigned int opt;
int optlen;
struct in_addr dummy;
if ((ip = getprotobyname("ip")) != 0)
ipproto = ip->p_proto;
else
ipproto = IPPROTO_IP;
if (getsockopt(fd, ipproto, IP_OPTIONS, (char *) optbuf, &optsize) == 0
&& optsize != 0) {
/*
* Horror! 4.[34] BSD getsockopt() prepends the first-hop destination
* address to the result IP options list when source routing options
* are present (see <netinet/ip_var.h>), but produces no output for
* other IP options. Solaris 2.x getsockopt() does produce output for
* non-routing IP options, and uses the same format as BSD even when
* the space for the destination address is unused. The code below
* does the right thing with 4.[34]BSD derivatives and Solaris 2, but
* may occasionally miss source routing options on incompatible
* systems such as Linux. Their choice.
*
* Look for source routing options. Drop the connection when one is
* found. Just wiping the IP options is insufficient: we would still
* help the attacker by providing a real TCP sequence number, and the
* attacker would still be able to send packets (blind spoofing). I
* discussed this attack with Niels Provos, half a year before the
* attack was described in open mailing lists.
*
* It would be cleaner to just return a yes/no reply and let the caller
* decide how to deal with it. Resident servers should not terminate.
* However I am not prepared to make changes to internal interfaces
* on short notice.
*/
#define ADDR_LEN sizeof(dummy.s_addr)
for (cp = optbuf + ADDR_LEN; cp < optbuf + optsize; cp += optlen) {
opt = cp[IPOPT_OPTVAL];
if (opt == IPOPT_LSRR || opt == IPOPT_SSRR) {
syslog(LOG_WARNING,
"refused connect from %s with IP source routing options",
eval_client(request));
shutdown(fd, 2);
return;
}
if (opt == IPOPT_EOL)
break;
if (opt == IPOPT_NOP) {
optlen = 1;
} else {
optlen = cp[IPOPT_OLEN];
if (optlen <= 0) /* Do not loop! */
break;
}
}
lp = lbuf;
for (cp = optbuf; optsize > 0; cp++, optsize--, lp += 3)
sprintf(lp, " %2.2x", *cp);
syslog(LOG_NOTICE,
"connect from %s with IP options (ignored):%s",
eval_client(request), lbuf);
if (setsockopt(fd, ipproto, IP_OPTIONS, (char *) 0, optsize) != 0) {
syslog(LOG_ERR, "setsockopt IP_OPTIONS NULL: %m");
shutdown(fd, 2);
}
}
#endif
}

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/*
* On socket-only systems, fromhost() is nothing but an alias for the
* socket-specific sock_host() function.
*
* On systems with sockets and TLI, fromhost() determines the type of API
* (sockets, TLI), then invokes the appropriate API-specific routines.
*
* Diagnostics are reported through syslog(3).
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) fromhost.c 1.17 94/12/28 17:42:23";
#endif
#if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
/* System libraries. */
#include <sys/types.h>
#include <sys/tiuser.h>
#include <stropts.h>
/* Local stuff. */
#include "tcpd.h"
/* fromhost - find out what network API we should use */
void fromhost(request)
struct request_info *request;
{
/*
* On systems with streams support the IP network protocol family may be
* accessible via more than one programming interface: Berkeley sockets
* and the Transport Level Interface (TLI).
*
* Thus, we must first find out what programming interface to use: sockets
* or TLI. On some systems, sockets are not part of the streams system,
* so if request->fd is not a stream we simply assume sockets.
*/
if (ioctl(request->fd, I_FIND, "timod") > 0) {
tli_host(request);
} else {
sock_host(request);
}
}
#endif /* TLI || PTX || TLI_SEQUENT */

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.TH HOSTS_ACCESS 3
.SH NAME
hosts_access, hosts_ctl, request_init, request_set \- access control library
.SH SYNOPSIS
.nf
#include "tcpd.h"
extern int allow_severity;
extern int deny_severity;
struct request_info *request_init(request, key, value, ..., 0)
struct request_info *request;
struct request_info *request_set(request, key, value, ..., 0)
struct request_info *request;
int hosts_access(request)
struct request_info *request;
int hosts_ctl(daemon, client_name, client_addr, client_user)
char *daemon;
char *client_name;
char *client_addr;
char *client_user;
.fi
.SH DESCRIPTION
The routines described in this document are part of the \fIlibwrap.a\fR
library. They implement a rule-based access control language with
optional shell commands that are executed when a rule fires.
.PP
request_init() initializes a structure with information about a client
request. request_set() updates an already initialized request
structure. Both functions take a variable-length list of key-value
pairs and return their first argument. The argument lists are
terminated with a zero key value. All string-valued arguments are
copied. The expected keys (and corresponding value types) are:
.IP "RQ_FILE (int)"
The file descriptor associated with the request.
.IP "RQ_CLIENT_NAME (char *)"
The client host name.
.IP "RQ_CLIENT_ADDR (char *)"
A printable representation of the client network address.
.IP "RQ_CLIENT_SIN (struct sockaddr_in *)"
An internal representation of the client network address and port. The
contents of the structure are not copied.
.IP "RQ_SERVER_NAME (char *)"
The hostname associated with the server endpoint address.
.IP "RQ_SERVER_ADDR (char *)"
A printable representation of the server endpoint address.
.IP "RQ_SERVER_SIN (struct sockaddr_in *)"
An internal representation of the server endpoint address and port.
The contents of the structure are not copied.
.IP "RQ_DAEMON (char *)"
The name of the daemon process running on the server host.
.IP "RQ_USER (char *)"
The name of the user on whose behalf the client host makes the request.
.PP
hosts_access() consults the access control tables described in the
\fIhosts_access(5)\fR manual page. When internal endpoint information
is available, host names and client user names are looked up on demand,
using the request structure as a cache. hosts_access() returns zero if
access should be denied.
.PP
hosts_ctl() is a wrapper around the request_init() and hosts_access()
routines with a perhaps more convenient interface (though it does not
pass on enough information to support automated client username
lookups). The client host address, client host name and username
arguments should contain valid data or STRING_UNKNOWN. hosts_ctl()
returns zero if access should be denied.
.PP
The \fIallow_severity\fR and \fIdeny_severity\fR variables determine
how accepted and rejected requests may be logged. They must be provided
by the caller and may be modified by rules in the access control
tables.
.SH DIAGNOSTICS
Problems are reported via the syslog daemon.
.SH SEE ALSO
hosts_access(5), format of the access control tables.
hosts_options(5), optional extensions to the base language.
.SH FILES
/etc/hosts.allow, /etc/hosts.deny, access control tables.
.SH BUGS
hosts_access() uses the strtok() library function. This may interfere
with other code that relies on strtok().
.SH AUTHOR
.na
.nf
Wietse Venema (wietse@wzv.win.tue.nl)
Department of Mathematics and Computing Science
Eindhoven University of Technology
Den Dolech 2, P.O. Box 513,
5600 MB Eindhoven, The Netherlands
\" @(#) hosts_access.3 1.8 96/02/11 17:01:26

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@ -0,0 +1,378 @@
.TH HOSTS_ACCESS 5
.SH NAME
hosts_access \- format of host access control files
.SH DESCRIPTION
This manual page describes a simple access control language that is
based on client (host name/address, user name), and server (process
name, host name/address) patterns. Examples are given at the end. The
impatient reader is encouraged to skip to the EXAMPLES section for a
quick introduction.
.PP
An extended version of the access control language is described in the
\fIhosts_options\fR(5) document. The extensions are turned on at
program build time by building with -DPROCESS_OPTIONS.
.PP
In the following text, \fIdaemon\fR is the the process name of a
network daemon process, and \fIclient\fR is the name and/or address of
a host requesting service. Network daemon process names are specified
in the inetd configuration file.
.SH ACCESS CONTROL FILES
The access control software consults two files. The search stops
at the first match:
.IP \(bu
Access will be granted when a (daemon,client) pair matches an entry in
the \fI/etc/hosts.allow\fR file.
.IP \(bu
Otherwise, access will be denied when a (daemon,client) pair matches an
entry in the \fI/etc/hosts.deny\fR file.
.IP \(bu
Otherwise, access will be granted.
.PP
A non-existing access control file is treated as if it were an empty
file. Thus, access control can be turned off by providing no access
control files.
.SH ACCESS CONTROL RULES
Each access control file consists of zero or more lines of text. These
lines are processed in order of appearance. The search terminates when a
match is found.
.IP \(bu
A newline character is ignored when it is preceded by a backslash
character. This permits you to break up long lines so that they are
easier to edit.
.IP \(bu
Blank lines or lines that begin with a `#\' character are ignored.
This permits you to insert comments and whitespace so that the tables
are easier to read.
.IP \(bu
All other lines should satisfy the following format, things between []
being optional:
.sp
.ti +3
daemon_list : client_list [ : shell_command ]
.PP
\fIdaemon_list\fR is a list of one or more daemon process names
(argv[0] values) or wildcards (see below).
.PP
\fIclient_list\fR is a list
of one or more host names, host addresses, patterns or wildcards (see
below) that will be matched against the client host name or address.
.PP
The more complex forms \fIdaemon@host\fR and \fIuser@host\fR are
explained in the sections on server endpoint patterns and on client
username lookups, respectively.
.PP
List elements should be separated by blanks and/or commas.
.PP
With the exception of NIS (YP) netgroup lookups, all access control
checks are case insensitive.
.ne 4
.SH PATTERNS
The access control language implements the following patterns:
.IP \(bu
A string that begins with a `.\' character. A host name is matched if
the last components of its name match the specified pattern. For
example, the pattern `.tue.nl\' matches the host name
`wzv.win.tue.nl\'.
.IP \(bu
A string that ends with a `.\' character. A host address is matched if
its first numeric fields match the given string. For example, the
pattern `131.155.\' matches the address of (almost) every host on the
Eind\%hoven University network (131.155.x.x).
.IP \(bu
A string that begins with an `@\' character is treated as an NIS
(formerly YP) netgroup name. A host name is matched if it is a host
member of the specified netgroup. Netgroup matches are not supported
for daemon process names or for client user names.
.IP \(bu
An expression of the form `n.n.n.n/m.m.m.m\' is interpreted as a
`net/mask\' pair. A host address is matched if `net\' is equal to the
bitwise AND of the address and the `mask\'. For example, the net/mask
pattern `131.155.72.0/255.255.254.0\' matches every address in the
range `131.155.72.0\' through `131.155.73.255\'.
.SH WILDCARDS
The access control language supports explicit wildcards:
.IP ALL
The universal wildcard, always matches.
.IP LOCAL
Matches any host whose name does not contain a dot character.
.IP UNKNOWN
Matches any user whose name is unknown, and matches any host whose name
\fIor\fR address are unknown. This pattern should be used with care:
host names may be unavailable due to temporary name server problems. A
network address will be unavailable when the software cannot figure out
what type of network it is talking to.
.IP KNOWN
Matches any user whose name is known, and matches any host whose name
\fIand\fR address are known. This pattern should be used with care:
host names may be unavailable due to temporary name server problems. A
network address will be unavailable when the software cannot figure out
what type of network it is talking to.
.IP PARANOID
Matches any host whose name does not match its address. When tcpd is
built with -DPARANOID (default mode), it drops requests from such
clients even before looking at the access control tables. Build
without -DPARANOID when you want more control over such requests.
.ne 6
.SH OPERATORS
.IP EXCEPT
Intended use is of the form: `list_1 EXCEPT list_2\'; this construct
matches anything that matches \fIlist_1\fR unless it matches
\fIlist_2\fR. The EXCEPT operator can be used in daemon_lists and in
client_lists. The EXCEPT operator can be nested: if the control
language would permit the use of parentheses, `a EXCEPT b EXCEPT c\'
would parse as `(a EXCEPT (b EXCEPT c))\'.
.br
.ne 6
.SH SHELL COMMANDS
If the first-matched access control rule contains a shell command, that
command is subjected to %<letter> substitutions (see next section).
The result is executed by a \fI/bin/sh\fR child process with standard
input, output and error connected to \fI/dev/null\fR. Specify an `&\'
at the end of the command if you do not want to wait until it has
completed.
.PP
Shell commands should not rely on the PATH setting of the inetd.
Instead, they should use absolute path names, or they should begin with
an explicit PATH=whatever statement.
.PP
The \fIhosts_options\fR(5) document describes an alternative language
that uses the shell command field in a different and incompatible way.
.SH % EXPANSIONS
The following expansions are available within shell commands:
.IP "%a (%A)"
The client (server) host address.
.IP %c
Client information: user@host, user@address, a host name, or just an
address, depending on how much information is available.
.IP %d
The daemon process name (argv[0] value).
.IP "%h (%H)"
The client (server) host name or address, if the host name is
unavailable.
.IP "%n (%N)"
The client (server) host name (or "unknown" or "paranoid").
.IP %p
The daemon process id.
.IP %s
Server information: daemon@host, daemon@address, or just a daemon name,
depending on how much information is available.
.IP %u
The client user name (or "unknown").
.IP %%
Expands to a single `%\' character.
.PP
Characters in % expansions that may confuse the shell are replaced by
underscores.
.SH SERVER ENDPOINT PATTERNS
In order to distinguish clients by the network address that they
connect to, use patterns of the form:
.sp
.ti +3
process_name@host_pattern : client_list ...
.sp
Patterns like these can be used when the machine has different internet
addresses with different internet hostnames. Service providers can use
this facility to offer FTP, GOPHER or WWW archives with internet names
that may even belong to different organizations. See also the `twist'
option in the hosts_options(5) document. Some systems (Solaris,
FreeBSD) can have more than one internet address on one physical
interface; with other systems you may have to resort to SLIP or PPP
pseudo interfaces that live in a dedicated network address space.
.sp
The host_pattern obeys the same syntax rules as host names and
addresses in client_list context. Usually, server endpoint information
is available only with connection-oriented services.
.SH CLIENT USERNAME LOOKUP
When the client host supports the RFC 931 protocol or one of its
descendants (TAP, IDENT, RFC 1413) the wrapper programs can retrieve
additional information about the owner of a connection. Client username
information, when available, is logged together with the client host
name, and can be used to match patterns like:
.PP
.ti +3
daemon_list : ... user_pattern@host_pattern ...
.PP
The daemon wrappers can be configured at compile time to perform
rule-driven username lookups (default) or to always interrogate the
client host. In the case of rule-driven username lookups, the above
rule would cause username lookup only when both the \fIdaemon_list\fR
and the \fIhost_pattern\fR match.
.PP
A user pattern has the same syntax as a daemon process pattern, so the
same wildcards apply (netgroup membership is not supported). One
should not get carried away with username lookups, though.
.IP \(bu
The client username information cannot be trusted when it is needed
most, i.e. when the client system has been compromised. In general,
ALL and (UN)KNOWN are the only user name patterns that make sense.
.IP \(bu
Username lookups are possible only with TCP-based services, and only
when the client host runs a suitable daemon; in all other cases the
result is "unknown".
.IP \(bu
A well-known UNIX kernel bug may cause loss of service when username
lookups are blocked by a firewall. The wrapper README document
describes a procedure to find out if your kernel has this bug.
.IP \(bu
Username lookups may cause noticeable delays for non-UNIX users. The
default timeout for username lookups is 10 seconds: too short to cope
with slow networks, but long enough to irritate PC users.
.PP
Selective username lookups can alleviate the last problem. For example,
a rule like:
.PP
.ti +3
daemon_list : @pcnetgroup ALL@ALL
.PP
would match members of the pc netgroup without doing username lookups,
but would perform username lookups with all other systems.
.SH DETECTING ADDRESS SPOOFING ATTACKS
A flaw in the sequence number generator of many TCP/IP implementations
allows intruders to easily impersonate trusted hosts and to break in
via, for example, the remote shell service. The IDENT (RFC931 etc.)
service can be used to detect such and other host address spoofing
attacks.
.PP
Before accepting a client request, the wrappers can use the IDENT
service to find out that the client did not send the request at all.
When the client host provides IDENT service, a negative IDENT lookup
result (the client matches `UNKNOWN@host') is strong evidence of a host
spoofing attack.
.PP
A positive IDENT lookup result (the client matches `KNOWN@host') is
less trustworthy. It is possible for an intruder to spoof both the
client connection and the IDENT lookup, although doing so is much
harder than spoofing just a client connection. It may also be that
the client\'s IDENT server is lying.
.PP
Note: IDENT lookups don\'t work with UDP services.
.SH EXAMPLES
The language is flexible enough that different types of access control
policy can be expressed with a minimum of fuss. Although the language
uses two access control tables, the most common policies can be
implemented with one of the tables being trivial or even empty.
.PP
When reading the examples below it is important to realize that the
allow table is scanned before the deny table, that the search
terminates when a match is found, and that access is granted when no
match is found at all.
.PP
The examples use host and domain names. They can be improved by
including address and/or network/netmask information, to reduce the
impact of temporary name server lookup failures.
.SH MOSTLY CLOSED
In this case, access is denied by default. Only explicitly authorized
hosts are permitted access.
.PP
The default policy (no access) is implemented with a trivial deny
file:
.PP
.ne 2
/etc/hosts.deny:
.in +3
ALL: ALL
.PP
This denies all service to all hosts, unless they are permitted access
by entries in the allow file.
.PP
The explicitly authorized hosts are listed in the allow file.
For example:
.PP
.ne 2
/etc/hosts.allow:
.in +3
ALL: LOCAL @some_netgroup
.br
ALL: .foobar.edu EXCEPT terminalserver.foobar.edu
.PP
The first rule permits access from hosts in the local domain (no `.\'
in the host name) and from members of the \fIsome_netgroup\fP
netgroup. The second rule permits access from all hosts in the
\fIfoobar.edu\fP domain (notice the leading dot), with the exception of
\fIterminalserver.foobar.edu\fP.
.SH MOSTLY OPEN
Here, access is granted by default; only explicitly specified hosts are
refused service.
.PP
The default policy (access granted) makes the allow file redundant so
that it can be omitted. The explicitly non-authorized hosts are listed
in the deny file. For example:
.PP
/etc/hosts.deny:
.in +3
ALL: some.host.name, .some.domain
.br
ALL EXCEPT in.fingerd: other.host.name, .other.domain
.PP
The first rule denies some hosts and domains all services; the second
rule still permits finger requests from other hosts and domains.
.SH BOOBY TRAPS
The next example permits tftp requests from hosts in the local domain
(notice the leading dot). Requests from any other hosts are denied.
Instead of the requested file, a finger probe is sent to the offending
host. The result is mailed to the superuser.
.PP
.ne 2
/etc/hosts.allow:
.in +3
.nf
in.tftpd: LOCAL, .my.domain
.PP
.ne 2
/etc/hosts.deny:
.in +3
.nf
in.tftpd: ALL: (/some/where/safe_finger -l @%h | \\
/usr/ucb/mail -s %d-%h root) &
.fi
.PP
The safe_finger command comes with the tcpd wrapper and should be
installed in a suitable place. It limits possible damage from data sent
by the remote finger server. It gives better protection than the
standard finger command.
.PP
The expansion of the %h (client host) and %d (service name) sequences
is described in the section on shell commands.
.PP
Warning: do not booby-trap your finger daemon, unless you are prepared
for infinite finger loops.
.PP
On network firewall systems this trick can be carried even further.
The typical network firewall only provides a limited set of services to
the outer world. All other services can be "bugged" just like the above
tftp example. The result is an excellent early-warning system.
.br
.ne 4
.SH DIAGNOSTICS
An error is reported when a syntax error is found in a host access
control rule; when the length of an access control rule exceeds the
capacity of an internal buffer; when an access control rule is not
terminated by a newline character; when the result of %<letter>
expansion would overflow an internal buffer; when a system call fails
that shouldn\'t. All problems are reported via the syslog daemon.
.SH FILES
.na
.nf
/etc/hosts.allow, (daemon,client) pairs that are granted access.
/etc/hosts.deny, (daemon,client) pairs that are denied access.
.ad
.fi
.SH SEE ALSO
.nf
tcpd(8) tcp/ip daemon wrapper program.
tcpdchk(8), tcpdmatch(8), test programs.
.SH BUGS
If a name server lookup times out, the host name will not be available
to the access control software, even though the host is registered.
.PP
Domain name server lookups are case insensitive; NIS (formerly YP)
netgroup lookups are case sensitive.
.SH AUTHOR
.na
.nf
Wietse Venema (wietse@wzv.win.tue.nl)
Department of Mathematics and Computing Science
Eindhoven University of Technology
Den Dolech 2, P.O. Box 513,
5600 MB Eindhoven, The Netherlands
\" @(#) hosts_access.5 1.20 95/01/30 19:51:46

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@ -0,0 +1,331 @@
/*
* This module implements a simple access control language that is based on
* host (or domain) names, NIS (host) netgroup names, IP addresses (or
* network numbers) and daemon process names. When a match is found the
* search is terminated, and depending on whether PROCESS_OPTIONS is defined,
* a list of options is executed or an optional shell command is executed.
*
* Host and user names are looked up on demand, provided that suitable endpoint
* information is available as sockaddr_in structures or TLI netbufs. As a
* side effect, the pattern matching process may change the contents of
* request structure fields.
*
* Diagnostics are reported through syslog(3).
*
* Compile with -DNETGROUP if your library provides support for netgroups.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) hosts_access.c 1.21 97/02/12 02:13:22";
#endif
/* System libraries. */
#include <sys/types.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <syslog.h>
#include <ctype.h>
#include <errno.h>
#include <setjmp.h>
#include <string.h>
extern char *fgets();
extern int errno;
#ifndef INADDR_NONE
#define INADDR_NONE (-1) /* XXX should be 0xffffffff */
#endif
/* Local stuff. */
#include "tcpd.h"
/* Error handling. */
extern jmp_buf tcpd_buf;
/* Delimiters for lists of daemons or clients. */
static char sep[] = ", \t\r\n";
/* Constants to be used in assignments only, not in comparisons... */
#define YES 1
#define NO 0
/*
* These variables are globally visible so that they can be redirected in
* verification mode.
*/
char *hosts_allow_table = HOSTS_ALLOW;
char *hosts_deny_table = HOSTS_DENY;
int hosts_access_verbose = 0;
/*
* In a long-running process, we are not at liberty to just go away.
*/
int resident = (-1); /* -1, 0: unknown; +1: yes */
/* Forward declarations. */
static int table_match();
static int list_match();
static int server_match();
static int client_match();
static int host_match();
static int string_match();
static int masked_match();
/* Size of logical line buffer. */
#define BUFLEN 2048
/* hosts_access - host access control facility */
int hosts_access(request)
struct request_info *request;
{
int verdict;
/*
* If the (daemon, client) pair is matched by an entry in the file
* /etc/hosts.allow, access is granted. Otherwise, if the (daemon,
* client) pair is matched by an entry in the file /etc/hosts.deny,
* access is denied. Otherwise, access is granted. A non-existent
* access-control file is treated as an empty file.
*
* After a rule has been matched, the optional language extensions may
* decide to grant or refuse service anyway. Or, while a rule is being
* processed, a serious error is found, and it seems better to play safe
* and deny service. All this is done by jumping back into the
* hosts_access() routine, bypassing the regular return from the
* table_match() function calls below.
*/
if (resident <= 0)
resident++;
verdict = setjmp(tcpd_buf);
if (verdict != 0)
return (verdict == AC_PERMIT);
if (table_match(hosts_allow_table, request))
return (YES);
if (table_match(hosts_deny_table, request))
return (NO);
return (YES);
}
/* table_match - match table entries with (daemon, client) pair */
static int table_match(table, request)
char *table;
struct request_info *request;
{
FILE *fp;
char sv_list[BUFLEN]; /* becomes list of daemons */
char *cl_list; /* becomes list of clients */
char *sh_cmd; /* becomes optional shell command */
int match = NO;
struct tcpd_context saved_context;
saved_context = tcpd_context; /* stupid compilers */
/*
* Between the fopen() and fclose() calls, avoid jumps that may cause
* file descriptor leaks.
*/
if ((fp = fopen(table, "r")) != 0) {
tcpd_context.file = table;
tcpd_context.line = 0;
while (match == NO && xgets(sv_list, sizeof(sv_list), fp) != 0) {
if (sv_list[strlen(sv_list) - 1] != '\n') {
tcpd_warn("missing newline or line too long");
continue;
}
if (sv_list[0] == '#' || sv_list[strspn(sv_list, " \t\r\n")] == 0)
continue;
if ((cl_list = split_at(sv_list, ':')) == 0) {
tcpd_warn("missing \":\" separator");
continue;
}
sh_cmd = split_at(cl_list, ':');
match = list_match(sv_list, request, server_match)
&& list_match(cl_list, request, client_match);
}
(void) fclose(fp);
} else if (errno != ENOENT) {
tcpd_warn("cannot open %s: %m", table);
}
if (match) {
if (hosts_access_verbose > 1)
syslog(LOG_DEBUG, "matched: %s line %d",
tcpd_context.file, tcpd_context.line);
if (sh_cmd) {
#ifdef PROCESS_OPTIONS
process_options(sh_cmd, request);
#else
char cmd[BUFSIZ];
shell_cmd(percent_x(cmd, sizeof(cmd), sh_cmd, request));
#endif
}
}
tcpd_context = saved_context;
return (match);
}
/* list_match - match a request against a list of patterns with exceptions */
static int list_match(list, request, match_fn)
char *list;
struct request_info *request;
int (*match_fn) ();
{
char *tok;
/*
* Process tokens one at a time. We have exhausted all possible matches
* when we reach an "EXCEPT" token or the end of the list. If we do find
* a match, look for an "EXCEPT" list and recurse to determine whether
* the match is affected by any exceptions.
*/
for (tok = strtok(list, sep); tok != 0; tok = strtok((char *) 0, sep)) {
if (STR_EQ(tok, "EXCEPT")) /* EXCEPT: give up */
return (NO);
if (match_fn(tok, request)) { /* YES: look for exceptions */
while ((tok = strtok((char *) 0, sep)) && STR_NE(tok, "EXCEPT"))
/* VOID */ ;
return (tok == 0 || list_match((char *) 0, request, match_fn) == 0);
}
}
return (NO);
}
/* server_match - match server information */
static int server_match(tok, request)
char *tok;
struct request_info *request;
{
char *host;
if ((host = split_at(tok + 1, '@')) == 0) { /* plain daemon */
return (string_match(tok, eval_daemon(request)));
} else { /* daemon@host */
return (string_match(tok, eval_daemon(request))
&& host_match(host, request->server));
}
}
/* client_match - match client information */
static int client_match(tok, request)
char *tok;
struct request_info *request;
{
char *host;
if ((host = split_at(tok + 1, '@')) == 0) { /* plain host */
return (host_match(tok, request->client));
} else { /* user@host */
return (host_match(host, request->client)
&& string_match(tok, eval_user(request)));
}
}
/* host_match - match host name and/or address against pattern */
static int host_match(tok, host)
char *tok;
struct host_info *host;
{
char *mask;
/*
* This code looks a little hairy because we want to avoid unnecessary
* hostname lookups.
*
* The KNOWN pattern requires that both address AND name be known; some
* patterns are specific to host names or to host addresses; all other
* patterns are satisfied when either the address OR the name match.
*/
if (tok[0] == '@') { /* netgroup: look it up */
#ifdef NETGROUP
static char *mydomain = 0;
if (mydomain == 0)
yp_get_default_domain(&mydomain);
return (innetgr(tok + 1, eval_hostname(host), (char *) 0, mydomain));
#else
tcpd_warn("netgroup support is disabled"); /* not tcpd_jump() */
return (NO);
#endif
} else if (STR_EQ(tok, "KNOWN")) { /* check address and name */
char *name = eval_hostname(host);
return (STR_NE(eval_hostaddr(host), unknown) && HOSTNAME_KNOWN(name));
} else if (STR_EQ(tok, "LOCAL")) { /* local: no dots in name */
char *name = eval_hostname(host);
return (strchr(name, '.') == 0 && HOSTNAME_KNOWN(name));
} else if ((mask = split_at(tok, '/')) != 0) { /* net/mask */
return (masked_match(tok, mask, eval_hostaddr(host)));
} else { /* anything else */
return (string_match(tok, eval_hostaddr(host))
|| (NOT_INADDR(tok) && string_match(tok, eval_hostname(host))));
}
}
/* string_match - match string against pattern */
static int string_match(tok, string)
char *tok;
char *string;
{
int n;
if (tok[0] == '.') { /* suffix */
n = strlen(string) - strlen(tok);
return (n > 0 && STR_EQ(tok, string + n));
} else if (STR_EQ(tok, "ALL")) { /* all: match any */
return (YES);
} else if (STR_EQ(tok, "KNOWN")) { /* not unknown */
return (STR_NE(string, unknown));
} else if (tok[(n = strlen(tok)) - 1] == '.') { /* prefix */
return (STRN_EQ(tok, string, n));
} else { /* exact match */
return (STR_EQ(tok, string));
}
}
/* masked_match - match address against netnumber/netmask */
static int masked_match(net_tok, mask_tok, string)
char *net_tok;
char *mask_tok;
char *string;
{
unsigned long net;
unsigned long mask;
unsigned long addr;
/*
* Disallow forms other than dotted quad: the treatment that inet_addr()
* gives to forms with less than four components is inconsistent with the
* access control language. John P. Rouillard <rouilj@cs.umb.edu>.
*/
if ((addr = dot_quad_addr(string)) == INADDR_NONE)
return (NO);
if ((net = dot_quad_addr(net_tok)) == INADDR_NONE
|| (mask = dot_quad_addr(mask_tok)) == INADDR_NONE) {
tcpd_warn("bad net/mask expression: %s/%s", net_tok, mask_tok);
return (NO); /* not tcpd_jump() */
}
return ((addr & mask) == net);
}

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@ -0,0 +1,38 @@
/*
* hosts_ctl() combines common applications of the host access control
* library routines. It bundles its arguments then calls the hosts_access()
* access control checker. The host name and user name arguments should be
* empty strings, STRING_UNKNOWN or real data. If a match is found, the
* optional shell command is executed.
*
* Restriction: this interface does not pass enough information to support
* selective remote username lookups or selective hostname double checks.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) hosts_ctl.c 1.4 94/12/28 17:42:27";
#endif
#include <stdio.h>
#include "tcpd.h"
/* hosts_ctl - limited interface to the hosts_access() routine */
int hosts_ctl(daemon, name, addr, user)
char *daemon;
char *name;
char *addr;
char *user;
{
struct request_info request;
return (hosts_access(request_init(&request,
RQ_DAEMON, daemon,
RQ_CLIENT_NAME, name,
RQ_CLIENT_ADDR, addr,
RQ_USER, user,
0)));
}

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@ -0,0 +1,172 @@
.TH HOSTS_OPTIONS 5
.SH NAME
hosts_options \- host access control language extensions
.SH DESCRIPTION
This document describes optional extensions to the language described
in the hosts_access(5) document. The extensions are enabled at program
build time. For example, by editing the Makefile and turning on the
PROCESS_OPTIONS compile-time option.
.PP
The extensible language uses the following format:
.sp
.ti +3
daemon_list : client_list : option : option ...
.PP
The first two fields are described in the hosts_access(5) manual page.
The remainder of the rules is a list of zero or more options. Any ":"
characters within options should be protected with a backslash.
.PP
An option is of the form "keyword" or "keyword value". Options are
processed in the specified order. Some options are subjected to
%<letter> substitutions. For the sake of backwards compatibility with
earlier versions, an "=" is permitted between keyword and value.
.SH LOGGING
.IP "severity mail.info"
.IP "severity notice"
Change the severity level at which the event will be logged. Facility
names (such as mail) are optional, and are not supported on systems
with older syslog implementations. The severity option can be used
to emphasize or to ignore specific events.
.SH ACCESS CONTROL
.IP "allow"
.IP "deny"
Grant (deny) service. These options must appear at the end of a rule.
.PP
The \fIallow\fR and \fIdeny\fR keywords make it possible to keep all
access control rules within a single file, for example in the
\fIhosts.allow\fR file.
.sp
To permit access from specific hosts only:
.sp
.ne 2
.ti +3
ALL: .friendly.domain: ALLOW
.ti +3
ALL: ALL: DENY
.sp
To permit access from all hosts except a few trouble makers:
.sp
.ne 2
.ti +3
ALL: .bad.domain: DENY
.ti +3
ALL: ALL: ALLOW
.sp
Notice the leading dot on the domain name patterns.
.SH RUNNING OTHER COMMANDS
.IP "spawn shell_command"
Execute, in a child process, the specified shell command, after
performing the %<letter> expansions described in the hosts_access(5)
manual page. The command is executed with stdin, stdout and stderr
connected to the null device, so that it won\'t mess up the
conversation with the client host. Example:
.sp
.nf
.ti +3
spawn (/some/where/safe_finger -l @%h | /usr/ucb/mail root) &
.fi
.sp
executes, in a background child process, the shell command "safe_finger
-l @%h | mail root" after replacing %h by the name or address of the
remote host.
.sp
The example uses the "safe_finger" command instead of the regular
"finger" command, to limit possible damage from data sent by the finger
server. The "safe_finger" command is part of the daemon wrapper
package; it is a wrapper around the regular finger command that filters
the data sent by the remote host.
.IP "twist shell_command"
Replace the current process by an instance of the specified shell
command, after performing the %<letter> expansions described in the
hosts_access(5) manual page. Stdin, stdout and stderr are connected to
the client process. This option must appear at the end of a rule.
.sp
To send a customized bounce message to the client instead of
running the real ftp daemon:
.sp
.nf
.ti +3
in.ftpd : ... : twist /bin/echo 421 Some bounce message
.fi
.sp
For an alternative way to talk to client processes, see the
\fIbanners\fR option below.
.sp
To run /some/other/in.telnetd without polluting its command-line
array or its process environment:
.sp
.nf
.ti +3
in.telnetd : ... : twist PATH=/some/other; exec in.telnetd
.fi
.sp
Warning: in case of UDP services, do not twist to commands that use
the standard I/O or the read(2)/write(2) routines to communicate with
the client process; UDP requires other I/O primitives.
.SH NETWORK OPTIONS
.IP "keepalive"
Causes the server to periodically send a message to the client. The
connection is considered broken when the client does not respond. The
keepalive option can be useful when users turn off their machine while
it is still connected to a server. The keepalive option is not useful
for datagram (UDP) services.
.IP "linger number_of_seconds"
Specifies how long the kernel will try to deliver not-yet delivered
data after the server process closes a connection.
.SH USERNAME LOOKUP
.IP "rfc931 [ timeout_in_seconds ]"
Look up the client user name with the RFC 931 (TAP, IDENT, RFC 1413)
protocol. This option is silently ignored in case of services based on
transports other than TCP. It requires that the client system runs an
RFC 931 (IDENT, etc.) -compliant daemon, and may cause noticeable
delays with connections from non-UNIX clients. The timeout period is
optional. If no timeout is specified a compile-time defined default
value is taken.
.SH MISCELLANEOUS
.IP "banners /some/directory"
Look for a file in `/some/directory' with the same name as the daemon
process (for example in.telnetd for the telnet service), and copy its
contents to the client. Newline characters are replaced by
carriage-return newline, and %<letter> sequences are expanded (see
the hosts_access(5) manual page).
.sp
The tcp wrappers source code distribution provides a sample makefile
(Banners.Makefile) for convenient banner maintenance.
.sp
Warning: banners are supported for connection-oriented (TCP) network
services only.
.IP "nice [ number ]"
Change the nice value of the process (default 10). Specify a positive
value to spend more CPU resources on other processes.
.IP "setenv name value"
Place a (name, value) pair into the process environment. The value is
subjected to %<letter> expansions and may contain whitespace (but
leading and trailing blanks are stripped off).
.sp
Warning: many network daemons reset their environment before spawning a
login or shell process.
.IP "umask 022"
Like the umask command that is built into the shell. An umask of 022
prevents the creation of files with group and world write permission.
The umask argument should be an octal number.
.IP "user nobody"
.IP "user nobody.kmem"
Assume the privileges of the "nobody" userid (or user "nobody", group
"kmem"). The first form is useful with inetd implementations that run
all services with root privilege. The second form is useful for
services that need special group privileges only.
.SH DIAGNOSTICS
When a syntax error is found in an access control rule, the error
is reported to the syslog daemon; further options will be ignored,
and service is denied.
.SH SEE ALSO
hosts_access(5), the default access control language
.SH AUTHOR
.na
.nf
Wietse Venema (wietse@wzv.win.tue.nl)
Department of Mathematics and Computing Science
Eindhoven University of Technology
Den Dolech 2, P.O. Box 513,
5600 MB Eindhoven, The Netherlands
\" @(#) hosts_options.5 1.10 94/12/28 17:42:28

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@ -0,0 +1,317 @@
/*
* Routines to parse an inetd.conf or tlid.conf file. This would be a great
* job for a PERL script.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) inetcf.c 1.7 97/02/12 02:13:23";
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
extern int errno;
extern void exit();
#include "tcpd.h"
#include "inetcf.h"
/*
* Network configuration files may live in unusual places. Here are some
* guesses. Shorter names follow longer ones.
*/
char *inet_files[] = {
"/private/etc/inetd.conf", /* NEXT */
"/etc/inet/inetd.conf", /* SYSV4 */
"/usr/etc/inetd.conf", /* IRIX?? */
"/etc/inetd.conf", /* BSD */
"/etc/net/tlid.conf", /* SYSV4?? */
"/etc/saf/tlid.conf", /* SYSV4?? */
"/etc/tlid.conf", /* SYSV4?? */
0,
};
static void inet_chk();
static char *base_name();
/*
* Structure with everything we know about a service.
*/
struct inet_ent {
struct inet_ent *next;
int type;
char name[1];
};
static struct inet_ent *inet_list = 0;
static char whitespace[] = " \t\r\n";
/* inet_conf - read in and examine inetd.conf (or tlid.conf) entries */
char *inet_cfg(conf)
char *conf;
{
char buf[BUFSIZ];
FILE *fp;
char *service;
char *protocol;
char *user;
char *path;
char *arg0;
char *arg1;
struct tcpd_context saved_context;
char *percent_m();
int i;
struct stat st;
saved_context = tcpd_context;
/*
* The inetd.conf (or tlid.conf) information is so useful that we insist
* on its availability. When no file is given run a series of educated
* guesses.
*/
if (conf != 0) {
if ((fp = fopen(conf, "r")) == 0) {
fprintf(stderr, percent_m(buf, "open %s: %m\n"), conf);
exit(1);
}
} else {
for (i = 0; inet_files[i] && (fp = fopen(inet_files[i], "r")) == 0; i++)
/* void */ ;
if (fp == 0) {
fprintf(stderr, "Cannot find your inetd.conf or tlid.conf file.\n");
fprintf(stderr, "Please specify its location.\n");
exit(1);
}
conf = inet_files[i];
check_path(conf, &st);
}
/*
* Process the file. After the 7.0 wrapper release it became clear that
* there are many more inetd.conf formats than the 8 systems that I had
* studied. EP/IX uses a two-line specification for rpc services; HP-UX
* permits long lines to be broken with backslash-newline.
*/
tcpd_context.file = conf;
tcpd_context.line = 0;
while (xgets(buf, sizeof(buf), fp)) {
service = strtok(buf, whitespace); /* service */
if (service == 0 || *service == '#')
continue;
if (STR_NE(service, "stream") && STR_NE(service, "dgram"))
strtok((char *) 0, whitespace); /* endpoint */
protocol = strtok((char *) 0, whitespace);
(void) strtok((char *) 0, whitespace); /* wait */
if ((user = strtok((char *) 0, whitespace)) == 0)
continue;
if (user[0] == '/') { /* user */
path = user;
} else { /* path */
if ((path = strtok((char *) 0, whitespace)) == 0)
continue;
}
if (path[0] == '?') /* IRIX optional service */
path++;
if (STR_EQ(path, "internal"))
continue;
if (path[strspn(path, "-0123456789")] == 0) {
/*
* ConvexOS puts RPC version numbers before path names. Jukka
* Ukkonen <ukkonen@csc.fi>.
*/
if ((path = strtok((char *) 0, whitespace)) == 0)
continue;
}
if ((arg0 = strtok((char *) 0, whitespace)) == 0) {
tcpd_warn("incomplete line");
continue;
}
if (arg0[strspn(arg0, "0123456789")] == 0) {
/*
* We're reading a tlid.conf file, the format is:
*
* ...stuff... path arg_count arguments mod_count modules
*/
if ((arg0 = strtok((char *) 0, whitespace)) == 0) {
tcpd_warn("incomplete line");
continue;
}
}
if ((arg1 = strtok((char *) 0, whitespace)) == 0)
arg1 = "";
inet_chk(protocol, path, arg0, arg1);
}
fclose(fp);
tcpd_context = saved_context;
return (conf);
}
/* inet_chk - examine one inetd.conf (tlid.conf?) entry */
static void inet_chk(protocol, path, arg0, arg1)
char *protocol;
char *path;
char *arg0;
char *arg1;
{
char daemon[BUFSIZ];
struct stat st;
int wrap_status = WR_MAYBE;
char *base_name_path = base_name(path);
char *tcpd_proc_name = (arg0[0] == '/' ? base_name(arg0) : arg0);
/*
* Always warn when the executable does not exist or when it is not
* executable.
*/
if (check_path(path, &st) < 0) {
tcpd_warn("%s: not found: %m", path);
} else if ((st.st_mode & 0100) == 0) {
tcpd_warn("%s: not executable", path);
}
/*
* Cheat on the miscd tests, nobody uses it anymore.
*/
if (STR_EQ(base_name_path, "miscd")) {
inet_set(arg0, WR_YES);
return;
}
/*
* While we are here...
*/
if (STR_EQ(tcpd_proc_name, "rexd") || STR_EQ(tcpd_proc_name, "rpc.rexd"))
tcpd_warn("%s may be an insecure service", tcpd_proc_name);
/*
* The tcpd program gets most of the attention.
*/
if (STR_EQ(base_name_path, "tcpd")) {
if (STR_EQ(tcpd_proc_name, "tcpd"))
tcpd_warn("%s is recursively calling itself", tcpd_proc_name);
wrap_status = WR_YES;
/*
* Check: some sites install the wrapper set-uid.
*/
if ((st.st_mode & 06000) != 0)
tcpd_warn("%s: file is set-uid or set-gid", path);
/*
* Check: some sites insert tcpd in inetd.conf, instead of replacing
* the daemon pathname.
*/
if (arg0[0] == '/' && STR_EQ(tcpd_proc_name, base_name(arg1)))
tcpd_warn("%s inserted before %s", path, arg0);
/*
* Check: make sure files exist and are executable. On some systems
* the network daemons are set-uid so we cannot complain. Note that
* tcpd takes the basename only in case of absolute pathnames.
*/
if (arg0[0] == '/') { /* absolute path */
if (check_path(arg0, &st) < 0) {
tcpd_warn("%s: not found: %m", arg0);
} else if ((st.st_mode & 0100) == 0) {
tcpd_warn("%s: not executable", arg0);
}
} else { /* look in REAL_DAEMON_DIR */
sprintf(daemon, "%s/%s", REAL_DAEMON_DIR, arg0);
if (check_path(daemon, &st) < 0) {
tcpd_warn("%s: not found in %s: %m",
arg0, REAL_DAEMON_DIR);
} else if ((st.st_mode & 0100) == 0) {
tcpd_warn("%s: not executable", daemon);
}
}
} else {
/*
* No tcpd program found. Perhaps they used the "simple installation"
* recipe. Look for a file with the same basename in REAL_DAEMON_DIR.
* Draw some conservative conclusions when a distinct file is found.
*/
sprintf(daemon, "%s/%s", REAL_DAEMON_DIR, arg0);
if (STR_EQ(path, daemon)) {
wrap_status = WR_NOT;
} else if (check_path(daemon, &st) >= 0) {
wrap_status = WR_MAYBE;
} else if (errno == ENOENT) {
wrap_status = WR_NOT;
} else {
tcpd_warn("%s: file lookup: %m", daemon);
wrap_status = WR_MAYBE;
}
}
/*
* Alas, we cannot wrap rpc/tcp services.
*/
if (wrap_status == WR_YES && STR_EQ(protocol, "rpc/tcp"))
tcpd_warn("%s: cannot wrap rpc/tcp services", tcpd_proc_name);
inet_set(tcpd_proc_name, wrap_status);
}
/* inet_set - remember service status */
void inet_set(name, type)
char *name;
int type;
{
struct inet_ent *ip =
(struct inet_ent *) malloc(sizeof(struct inet_ent) + strlen(name));
if (ip == 0) {
fprintf(stderr, "out of memory\n");
exit(1);
}
ip->next = inet_list;
strcpy(ip->name, name);
ip->type = type;
inet_list = ip;
}
/* inet_get - look up service status */
int inet_get(name)
char *name;
{
struct inet_ent *ip;
if (inet_list == 0)
return (WR_MAYBE);
for (ip = inet_list; ip; ip = ip->next)
if (STR_EQ(ip->name, name))
return (ip->type);
return (-1);
}
/* base_name - compute last pathname component */
static char *base_name(path)
char *path;
{
char *cp;
if ((cp = strrchr(path, '/')) != 0)
path = cp + 1;
return (path);
}

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/*
* @(#) inetcf.h 1.1 94/12/28 17:42:30
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
extern char *inet_cfg(); /* read inetd.conf file */
extern void inet_set(); /* remember internet service */
extern int inet_get(); /* look up internet service */
#define WR_UNKNOWN (-1) /* service unknown */
#define WR_NOT 1 /* may not be wrapped */
#define WR_MAYBE 2 /* may be wrapped */
#define WR_YES 3 /* service is wrapped */

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/*
* Misc routines that are used by tcpd and by tcpdchk.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsic[] = "@(#) misc.c 1.2 96/02/11 17:01:29";
#endif
#include <sys/types.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <string.h>
#include "tcpd.h"
extern char *fgets();
#ifndef INADDR_NONE
#define INADDR_NONE (-1) /* XXX should be 0xffffffff */
#endif
/* xgets - fgets() with backslash-newline stripping */
char *xgets(ptr, len, fp)
char *ptr;
int len;
FILE *fp;
{
int got;
char *start = ptr;
while (fgets(ptr, len, fp)) {
got = strlen(ptr);
if (got >= 1 && ptr[got - 1] == '\n') {
tcpd_context.line++;
if (got >= 2 && ptr[got - 2] == '\\') {
got -= 2;
} else {
return (start);
}
}
ptr += got;
len -= got;
ptr[0] = 0;
}
return (ptr > start ? start : 0);
}
/* split_at - break string at delimiter or return NULL */
char *split_at(string, delimiter)
char *string;
int delimiter;
{
char *cp;
if ((cp = strchr(string, delimiter)) != 0)
*cp++ = 0;
return (cp);
}
/* dot_quad_addr - convert dotted quad to internal form */
unsigned long dot_quad_addr(str)
char *str;
{
int in_run = 0;
int runs = 0;
char *cp = str;
/* Count the number of runs of non-dot characters. */
while (*cp) {
if (*cp == '.') {
in_run = 0;
} else if (in_run == 0) {
in_run = 1;
runs++;
}
cp++;
}
return (runs == 4 ? inet_addr(str) : INADDR_NONE);
}

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/*
* Front end to the ULTRIX miscd service. The front end logs the remote host
* name and then invokes the real miscd daemon. Install as "/usr/etc/miscd",
* after renaming the real miscd daemon to the name defined with the
* REAL_MISCD macro.
*
* Connections and diagnostics are logged through syslog(3).
*
* The Ultrix miscd program implements (among others) the systat service, which
* pipes the output from who(1) to stdout. This information is potentially
* useful to systems crackers.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) miscd.c 1.10 96/02/11 17:01:30";
#endif
/* System libraries. */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <syslog.h>
#ifndef MAXPATHNAMELEN
#define MAXPATHNAMELEN BUFSIZ
#endif
#ifndef STDIN_FILENO
#define STDIN_FILENO 0
#endif
/* Local stuff. */
#include "patchlevel.h"
#include "tcpd.h"
int allow_severity = SEVERITY; /* run-time adjustable */
int deny_severity = LOG_WARNING; /* ditto */
main(argc, argv)
int argc;
char **argv;
{
struct request_info request;
char path[MAXPATHNAMELEN];
/* Attempt to prevent the creation of world-writable files. */
#ifdef DAEMON_UMASK
umask(DAEMON_UMASK);
#endif
/*
* Open a channel to the syslog daemon. Older versions of openlog()
* require only two arguments.
*/
#ifdef LOG_MAIL
(void) openlog(argv[0], LOG_PID, FACILITY);
#else
(void) openlog(argv[0], LOG_PID);
#endif
/*
* Find out the endpoint addresses of this conversation. Host name
* lookups and double checks will be done on demand.
*/
request_init(&request, RQ_DAEMON, argv[0], RQ_FILE, STDIN_FILENO, 0);
fromhost(&request);
/*
* Optionally look up and double check the remote host name. Sites
* concerned with security may choose to refuse connections from hosts
* that pretend to have someone elses host name.
*/
#ifdef PARANOID
if (STR_EQ(eval_hostname(request.client), paranoid))
refuse(&request);
#endif
/*
* The BSD rlogin and rsh daemons that came out after 4.3 BSD disallow
* socket options at the IP level. They do so for a good reason.
* Unfortunately, we cannot use this with SunOS 4.1.x because the
* getsockopt() system call can panic the system.
*/
#ifdef KILL_IP_OPTIONS
fix_options(&request);
#endif
/*
* Check whether this host can access the service in argv[0]. The
* access-control code invokes optional shell commands as specified in
* the access-control tables.
*/
#ifdef HOSTS_ACCESS
if (!hosts_access(&request))
refuse(&request);
#endif
/* Report request and invoke the real daemon program. */
syslog(allow_severity, "connect from %s", eval_client(&request));
sprintf(path, "%s/miscd", REAL_DAEMON_DIR);
closelog();
(void) execv(path, argv);
syslog(LOG_ERR, "error: cannot execute %s: %m", path);
clean_exit(&request);
/* NOTREACHED */
}

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/*
* What follows is an attempt to unify varargs.h and stdarg.h. I'd rather
* have this than #ifdefs all over the code.
*/
#ifdef __STDC__
#include <stdarg.h>
#define VARARGS(func,type,arg) func(type arg, ...)
#define VASTART(ap,type,name) va_start(ap,name)
#define VAEND(ap) va_end(ap)
#else
#include <varargs.h>
#define VARARGS(func,type,arg) func(va_alist) va_dcl
#define VASTART(ap,type,name) {type name; va_start(ap); name = va_arg(ap, type)
#define VAEND(ap) va_end(ap);}
#endif
extern char *percent_m();

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/*
* vsyslog() for sites without. In order to enable this code, build with
* -Dvsyslog=myvsyslog. We use a different name so that no accidents will
* happen when vsyslog() exists. On systems with vsyslog(), syslog() is
* typically implemented in terms of vsyslog().
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) myvsyslog.c 1.1 94/12/28 17:42:33";
#endif
#ifdef vsyslog
#include <stdio.h>
#include "tcpd.h"
#include "mystdarg.h"
myvsyslog(severity, format, ap)
int severity;
char *format;
va_list ap;
{
char fbuf[BUFSIZ];
char obuf[3 * STRING_LENGTH];
vsprintf(obuf, percent_m(fbuf, format), ap);
syslog(severity, "%s", obuf);
}
#endif

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/*
* This part for NCR UNIX with is from Andrew Maffei (arm@aqua.whoi.edu). It
* assumes TLI throughout. In order to look up endpoint address information
* we must talk to the "timod" streams module. For some reason "timod" wants
* to sit directly on top of the device driver. Therefore we pop off all
* streams modules except the driver, install the "timod" module so that we
* can figure out network addresses, and then restore the original state.
*/
#ifndef lint
static char sccsid[] = "@(#) ncr.c 1.1 94/12/28 17:42:34";
#endif
#include <sys/types.h>
#include <stdio.h>
#include <syslog.h>
#include <sys/tiuser.h>
#include <stropts.h>
#include <sys/conf.h>
#include "tcpd.h"
#define MAX_MODULE_COUNT 10 /* XXX */
/* fromhost - tear down the streams stack then rebuild it */
void fromhost(request)
struct request_info *request;
{
int i;
int num_mod;
struct str_list str_list;
struct str_mlist mod_buffer[MAX_MODULE_COUNT];
int fd = request->fd;
str_list.sl_nmods = MAX_MODULE_COUNT;
str_list.sl_modlist = &mod_buffer[0];
/*
* On systems with WIN streams support we have to be careful about what
* is on the stream we are passed. This code POPs off all modules above
* the pseudo driver, pushes timod, gets the host address information,
* pops timod and then pushes all modules back on the stream.
*
* Some state may be lost in this process. /usr/etc/tlid seems to do special
* things to the stream depending on the TCP port being serviced. (not a
* very nice thing to do!). It is unclear what to do if this code breaks
* - the stream may be left in an unknown condition.
*/
if ((num_mod = ioctl(fd, I_LIST, NULL)) < 0)
tcpd_warn("fromhost: LIST failed: %m");
if (ioctl(fd, I_LIST, &str_list) < 0)
tcpd_warn("fromhost: LIST failed: %m");
/*
* POP stream modules except for the driver.
*/
for (i = 0; i < num_mod - 1; i++)
if (ioctl(fd, I_POP, 0) < 0)
tcpd_warn("fromhost: POP %s: %m", mod_buffer[i].l_name);
/*
* PUSH timod so that host address ioctls can be executed.
*/
if (ioctl(fd, I_PUSH, "timod") < 0)
tcpd_warn("fromhost: PUSH timod: %m");
tli_host(request);
/*
* POP timod, we're done with it now.
*/
if (ioctl(fd, I_POP, 0) < 0)
tcpd_warn("fromhost: POP timod: %m");
/*
* Restore stream modules.
*/
for (i = num_mod - 2; i >= 0; i--)
if (ioctl(fd, I_PUSH, mod_buffer[i].l_name) < 0)
tcpd_warn("fromhost: PUSH %s: %m", mod_buffer[i].l_name);
}

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/*
* General skeleton for adding options to the access control language. The
* features offered by this module are documented in the hosts_options(5)
* manual page (source file: hosts_options.5, "nroff -man" format).
*
* Notes and warnings for those who want to add features:
*
* In case of errors, abort options processing and deny access. There are too
* many irreversible side effects to make error recovery feasible. For
* example, it makes no sense to continue after we have already changed the
* userid.
*
* In case of errors, do not terminate the process: the routines might be
* called from a long-running daemon that should run forever. Instead, call
* tcpd_jump() which does a non-local goto back into the hosts_access()
* routine.
*
* In case of severe errors, use clean_exit() instead of directly calling
* exit(), or the inetd may loop on an UDP request.
*
* In verification mode (for example, with the "tcpdmatch" command) the
* "dry_run" flag is set. In this mode, an option function should just "say"
* what it is going to do instead of really doing it.
*
* Some option functions do not return (for example, the twist option passes
* control to another program). In verification mode (dry_run flag is set)
* such options should clear the "dry_run" flag to inform the caller of this
* course of action.
*/
#ifndef lint
static char sccsid[] = "@(#) options.c 1.17 96/02/11 17:01:31";
#endif
/* System libraries. */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>
#include <syslog.h>
#include <pwd.h>
#include <grp.h>
#include <ctype.h>
#include <setjmp.h>
#include <string.h>
#ifndef MAXPATHNAMELEN
#define MAXPATHNAMELEN BUFSIZ
#endif
/* Local stuff. */
#include "tcpd.h"
/* Options runtime support. */
int dry_run = 0; /* flag set in verification mode */
extern jmp_buf tcpd_buf; /* tcpd_jump() support */
/* Options parser support. */
static char whitespace_eq[] = "= \t\r\n";
#define whitespace (whitespace_eq + 1)
static char *get_field(); /* chew :-delimited field off string */
static char *chop_string(); /* strip leading and trailing blanks */
/* List of functions that implement the options. Add yours here. */
static void user_option(); /* execute "user name.group" option */
static void group_option(); /* execute "group name" option */
static void umask_option(); /* execute "umask mask" option */
static void linger_option(); /* execute "linger time" option */
static void keepalive_option(); /* execute "keepalive" option */
static void spawn_option(); /* execute "spawn command" option */
static void twist_option(); /* execute "twist command" option */
static void rfc931_option(); /* execute "rfc931" option */
static void setenv_option(); /* execute "setenv name value" */
static void nice_option(); /* execute "nice" option */
static void severity_option(); /* execute "severity value" */
static void allow_option(); /* execute "allow" option */
static void deny_option(); /* execute "deny" option */
static void banners_option(); /* execute "banners path" option */
/* Structure of the options table. */
struct option {
char *name; /* keyword name, case is ignored */
void (*func) (); /* function that does the real work */
int flags; /* see below... */
};
#define NEED_ARG (1<<1) /* option requires argument */
#define USE_LAST (1<<2) /* option must be last */
#define OPT_ARG (1<<3) /* option has optional argument */
#define EXPAND_ARG (1<<4) /* do %x expansion on argument */
#define need_arg(o) ((o)->flags & NEED_ARG)
#define opt_arg(o) ((o)->flags & OPT_ARG)
#define permit_arg(o) ((o)->flags & (NEED_ARG | OPT_ARG))
#define use_last(o) ((o)->flags & USE_LAST)
#define expand_arg(o) ((o)->flags & EXPAND_ARG)
/* List of known keywords. Add yours here. */
static struct option option_table[] = {
"user", user_option, NEED_ARG,
"group", group_option, NEED_ARG,
"umask", umask_option, NEED_ARG,
"linger", linger_option, NEED_ARG,
"keepalive", keepalive_option, 0,
"spawn", spawn_option, NEED_ARG | EXPAND_ARG,
"twist", twist_option, NEED_ARG | EXPAND_ARG | USE_LAST,
"rfc931", rfc931_option, OPT_ARG,
"setenv", setenv_option, NEED_ARG | EXPAND_ARG,
"nice", nice_option, OPT_ARG,
"severity", severity_option, NEED_ARG,
"allow", allow_option, USE_LAST,
"deny", deny_option, USE_LAST,
"banners", banners_option, NEED_ARG,
0,
};
/* process_options - process access control options */
void process_options(options, request)
char *options;
struct request_info *request;
{
char *key;
char *value;
char *curr_opt;
char *next_opt;
struct option *op;
char bf[BUFSIZ];
for (curr_opt = get_field(options); curr_opt; curr_opt = next_opt) {
next_opt = get_field((char *) 0);
/*
* Separate the option into name and value parts. For backwards
* compatibility we ignore exactly one '=' between name and value.
*/
curr_opt = chop_string(curr_opt);
if (*(value = curr_opt + strcspn(curr_opt, whitespace_eq))) {
if (*value != '=') {
*value++ = 0;
value += strspn(value, whitespace);
}
if (*value == '=') {
*value++ = 0;
value += strspn(value, whitespace);
}
}
if (*value == 0)
value = 0;
key = curr_opt;
/*
* Disallow missing option names (and empty option fields).
*/
if (*key == 0)
tcpd_jump("missing option name");
/*
* Lookup the option-specific info and do some common error checks.
* Delegate option-specific processing to the specific functions.
*/
for (op = option_table; op->name && STR_NE(op->name, key); op++)
/* VOID */ ;
if (op->name == 0)
tcpd_jump("bad option name: \"%s\"", key);
if (!value && need_arg(op))
tcpd_jump("option \"%s\" requires value", key);
if (value && !permit_arg(op))
tcpd_jump("option \"%s\" requires no value", key);
if (next_opt && use_last(op))
tcpd_jump("option \"%s\" must be at end", key);
if (value && expand_arg(op))
value = chop_string(percent_x(bf, sizeof(bf), value, request));
if (hosts_access_verbose)
syslog(LOG_DEBUG, "option: %s %s", key, value ? value : "");
(*(op->func)) (value, request);
}
}
/* allow_option - grant access */
/* ARGSUSED */
static void allow_option(value, request)
char *value;
struct request_info *request;
{
longjmp(tcpd_buf, AC_PERMIT);
}
/* deny_option - deny access */
/* ARGSUSED */
static void deny_option(value, request)
char *value;
struct request_info *request;
{
longjmp(tcpd_buf, AC_DENY);
}
/* banners_option - expand %<char>, terminate each line with CRLF */
static void banners_option(value, request)
char *value;
struct request_info *request;
{
char path[MAXPATHNAMELEN];
char ibuf[BUFSIZ];
char obuf[2 * BUFSIZ];
struct stat st;
int ch;
FILE *fp;
sprintf(path, "%s/%s", value, eval_daemon(request));
if ((fp = fopen(path, "r")) != 0) {
while ((ch = fgetc(fp)) == 0)
write(request->fd, "", 1);
ungetc(ch, fp);
while (fgets(ibuf, sizeof(ibuf) - 1, fp)) {
if (split_at(ibuf, '\n'))
strcat(ibuf, "\r\n");
percent_x(obuf, sizeof(obuf), ibuf, request);
write(request->fd, obuf, strlen(obuf));
}
fclose(fp);
} else if (stat(value, &st) < 0) {
tcpd_warn("%s: %m", value);
}
}
/* group_option - switch group id */
/* ARGSUSED */
static void group_option(value, request)
char *value;
struct request_info *request;
{
struct group *grp;
struct group *getgrnam();
if ((grp = getgrnam(value)) == 0)
tcpd_jump("unknown group: \"%s\"", value);
endgrent();
if (dry_run == 0 && setgid(grp->gr_gid))
tcpd_jump("setgid(%s): %m", value);
}
/* user_option - switch user id */
/* ARGSUSED */
static void user_option(value, request)
char *value;
struct request_info *request;
{
struct passwd *pwd;
struct passwd *getpwnam();
char *group;
if ((group = split_at(value, '.')) != 0)
group_option(group, request);
if ((pwd = getpwnam(value)) == 0)
tcpd_jump("unknown user: \"%s\"", value);
endpwent();
if (dry_run == 0 && setuid(pwd->pw_uid))
tcpd_jump("setuid(%s): %m", value);
}
/* umask_option - set file creation mask */
/* ARGSUSED */
static void umask_option(value, request)
char *value;
struct request_info *request;
{
unsigned mask;
char junk;
if (sscanf(value, "%o%c", &mask, &junk) != 1 || (mask & 0777) != mask)
tcpd_jump("bad umask value: \"%s\"", value);
(void) umask(mask);
}
/* spawn_option - spawn a shell command and wait */
/* ARGSUSED */
static void spawn_option(value, request)
char *value;
struct request_info *request;
{
if (dry_run == 0)
shell_cmd(value);
}
/* linger_option - set the socket linger time (Marc Boucher <marc@cam.org>) */
/* ARGSUSED */
static void linger_option(value, request)
char *value;
struct request_info *request;
{
struct linger linger;
char junk;
if (sscanf(value, "%d%c", &linger.l_linger, &junk) != 1
|| linger.l_linger < 0)
tcpd_jump("bad linger value: \"%s\"", value);
if (dry_run == 0) {
linger.l_onoff = (linger.l_linger != 0);
if (setsockopt(request->fd, SOL_SOCKET, SO_LINGER, (char *) &linger,
sizeof(linger)) < 0)
tcpd_warn("setsockopt SO_LINGER %d: %m", linger.l_linger);
}
}
/* keepalive_option - set the socket keepalive option */
/* ARGSUSED */
static void keepalive_option(value, request)
char *value;
struct request_info *request;
{
static int on = 1;
if (dry_run == 0 && setsockopt(request->fd, SOL_SOCKET, SO_KEEPALIVE,
(char *) &on, sizeof(on)) < 0)
tcpd_warn("setsockopt SO_KEEPALIVE: %m");
}
/* nice_option - set nice value */
/* ARGSUSED */
static void nice_option(value, request)
char *value;
struct request_info *request;
{
int niceval = 10;
char junk;
if (value != 0 && sscanf(value, "%d%c", &niceval, &junk) != 1)
tcpd_jump("bad nice value: \"%s\"", value);
if (dry_run == 0 && nice(niceval) < 0)
tcpd_warn("nice(%d): %m", niceval);
}
/* twist_option - replace process by shell command */
static void twist_option(value, request)
char *value;
struct request_info *request;
{
char *error;
if (dry_run != 0) {
dry_run = 0;
} else {
if (resident > 0)
tcpd_jump("twist option in resident process");
syslog(deny_severity, "twist %s to %s", eval_client(request), value);
/* Before switching to the shell, set up stdin, stdout and stderr. */
#define maybe_dup2(from, to) ((from == to) ? to : (close(to), dup(from)))
if (maybe_dup2(request->fd, 0) != 0 ||
maybe_dup2(request->fd, 1) != 1 ||
maybe_dup2(request->fd, 2) != 2) {
error = "twist_option: dup: %m";
} else {
if (request->fd > 2)
close(request->fd);
(void) execl("/bin/sh", "sh", "-c", value, (char *) 0);
error = "twist_option: /bin/sh: %m";
}
/* Something went wrong: we MUST terminate the process. */
tcpd_warn(error);
clean_exit(request);
}
}
/* rfc931_option - look up remote user name */
static void rfc931_option(value, request)
char *value;
struct request_info *request;
{
int timeout;
char junk;
if (value != 0) {
if (sscanf(value, "%d%c", &timeout, &junk) != 1 || timeout <= 0)
tcpd_jump("bad rfc931 timeout: \"%s\"", value);
rfc931_timeout = timeout;
}
(void) eval_user(request);
}
/* setenv_option - set environment variable */
/* ARGSUSED */
static void setenv_option(value, request)
char *value;
struct request_info *request;
{
char *var_value;
if (*(var_value = value + strcspn(value, whitespace)))
*var_value++ = 0;
if (setenv(chop_string(value), chop_string(var_value), 1))
tcpd_jump("memory allocation failure");
}
/*
* The severity option goes last because it comes with a huge amount of ugly
* #ifdefs and tables.
*/
struct syslog_names {
char *name;
int value;
};
static struct syslog_names log_fac[] = {
#ifdef LOG_KERN
"kern", LOG_KERN,
#endif
#ifdef LOG_USER
"user", LOG_USER,
#endif
#ifdef LOG_MAIL
"mail", LOG_MAIL,
#endif
#ifdef LOG_DAEMON
"daemon", LOG_DAEMON,
#endif
#ifdef LOG_AUTH
"auth", LOG_AUTH,
#endif
#ifdef LOG_LPR
"lpr", LOG_LPR,
#endif
#ifdef LOG_NEWS
"news", LOG_NEWS,
#endif
#ifdef LOG_UUCP
"uucp", LOG_UUCP,
#endif
#ifdef LOG_CRON
"cron", LOG_CRON,
#endif
#ifdef LOG_LOCAL0
"local0", LOG_LOCAL0,
#endif
#ifdef LOG_LOCAL1
"local1", LOG_LOCAL1,
#endif
#ifdef LOG_LOCAL2
"local2", LOG_LOCAL2,
#endif
#ifdef LOG_LOCAL3
"local3", LOG_LOCAL3,
#endif
#ifdef LOG_LOCAL4
"local4", LOG_LOCAL4,
#endif
#ifdef LOG_LOCAL5
"local5", LOG_LOCAL5,
#endif
#ifdef LOG_LOCAL6
"local6", LOG_LOCAL6,
#endif
#ifdef LOG_LOCAL7
"local7", LOG_LOCAL7,
#endif
0,
};
static struct syslog_names log_sev[] = {
#ifdef LOG_EMERG
"emerg", LOG_EMERG,
#endif
#ifdef LOG_ALERT
"alert", LOG_ALERT,
#endif
#ifdef LOG_CRIT
"crit", LOG_CRIT,
#endif
#ifdef LOG_ERR
"err", LOG_ERR,
#endif
#ifdef LOG_WARNING
"warning", LOG_WARNING,
#endif
#ifdef LOG_NOTICE
"notice", LOG_NOTICE,
#endif
#ifdef LOG_INFO
"info", LOG_INFO,
#endif
#ifdef LOG_DEBUG
"debug", LOG_DEBUG,
#endif
0,
};
/* severity_map - lookup facility or severity value */
static int severity_map(table, name)
struct syslog_names *table;
char *name;
{
struct syslog_names *t;
for (t = table; t->name; t++)
if (STR_EQ(t->name, name))
return (t->value);
tcpd_jump("bad syslog facility or severity: \"%s\"", name);
/* NOTREACHED */
}
/* severity_option - change logging severity for this event (Dave Mitchell) */
/* ARGSUSED */
static void severity_option(value, request)
char *value;
struct request_info *request;
{
char *level = split_at(value, '.');
allow_severity = deny_severity = level ?
severity_map(log_fac, value) | severity_map(log_sev, level) :
severity_map(log_sev, value);
}
/* get_field - return pointer to next field in string */
static char *get_field(string)
char *string;
{
static char *last = "";
char *src;
char *dst;
char *ret;
int ch;
/*
* This function returns pointers to successive fields within a given
* string. ":" is the field separator; warn if the rule ends in one. It
* replaces a "\:" sequence by ":", without treating the result of
* substitution as field terminator. A null argument means resume search
* where the previous call terminated. This function destroys its
* argument.
*
* Work from explicit source or from memory. While processing \: we
* overwrite the input. This way we do not have to maintain buffers for
* copies of input fields.
*/
src = dst = ret = (string ? string : last);
if (src[0] == 0)
return (0);
while (ch = *src) {
if (ch == ':') {
if (*++src == 0)
tcpd_warn("rule ends in \":\"");
break;
}
if (ch == '\\' && src[1] == ':')
src++;
*dst++ = *src++;
}
last = src;
*dst = 0;
return (ret);
}
/* chop_string - strip leading and trailing blanks from string */
static char *chop_string(string)
register char *string;
{
char *start = 0;
char *end;
char *cp;
for (cp = string; *cp; cp++) {
if (!isspace(*cp)) {
if (start == 0)
start = cp;
end = cp;
}
}
return (start ? (end[1] = 0, start) : cp);
}

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#ifndef lint
static char patchlevel[] = "@(#) patchlevel 7.6 97/03/21 19:27:23";
#endif

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/*
* Replace %m by system error message.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) percent_m.c 1.1 94/12/28 17:42:37";
#endif
#include <stdio.h>
#include <errno.h>
#include <string.h>
extern int errno;
#ifndef SYS_ERRLIST_DEFINED
extern char *sys_errlist[];
extern int sys_nerr;
#endif
#include "mystdarg.h"
char *percent_m(obuf, ibuf)
char *obuf;
char *ibuf;
{
char *bp = obuf;
char *cp = ibuf;
while (*bp = *cp)
if (*cp == '%' && cp[1] == 'm') {
if (errno < sys_nerr && errno > 0) {
strcpy(bp, sys_errlist[errno]);
} else {
sprintf(bp, "Unknown error %d", errno);
}
bp += strlen(bp);
cp += 2;
} else {
bp++, cp++;
}
return (obuf);
}

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/*
* percent_x() takes a string and performs %<char> expansions. It aborts the
* program when the expansion would overflow the output buffer. The result
* of %<char> expansion may be passed on to a shell process. For this
* reason, characters with a special meaning to shells are replaced by
* underscores.
*
* Diagnostics are reported through syslog(3).
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) percent_x.c 1.4 94/12/28 17:42:37";
#endif
/* System libraries. */
#include <stdio.h>
#include <syslog.h>
#include <string.h>
extern void exit();
/* Local stuff. */
#include "tcpd.h"
/* percent_x - do %<char> expansion, abort if result buffer is too small */
char *percent_x(result, result_len, string, request)
char *result;
int result_len;
char *string;
struct request_info *request;
{
char *bp = result;
char *end = result + result_len - 1; /* end of result buffer */
char *expansion;
int expansion_len;
static char ok_chars[] = "1234567890!@%-_=+:,./\
abcdefghijklmnopqrstuvwxyz\
ABCDEFGHIJKLMNOPQRSTUVWXYZ";
char *str = string;
char *cp;
int ch;
/*
* Warning: we may be called from a child process or after pattern
* matching, so we cannot use clean_exit() or tcpd_jump().
*/
while (*str) {
if (*str == '%' && (ch = str[1]) != 0) {
str += 2;
expansion =
ch == 'a' ? eval_hostaddr(request->client) :
ch == 'A' ? eval_hostaddr(request->server) :
ch == 'c' ? eval_client(request) :
ch == 'd' ? eval_daemon(request) :
ch == 'h' ? eval_hostinfo(request->client) :
ch == 'H' ? eval_hostinfo(request->server) :
ch == 'n' ? eval_hostname(request->client) :
ch == 'N' ? eval_hostname(request->server) :
ch == 'p' ? eval_pid(request) :
ch == 's' ? eval_server(request) :
ch == 'u' ? eval_user(request) :
ch == '%' ? "%" : (tcpd_warn("unrecognized %%%c", ch), "");
for (cp = expansion; *(cp += strspn(cp, ok_chars)); /* */ )
*cp = '_';
expansion_len = cp - expansion;
} else {
expansion = str++;
expansion_len = 1;
}
if (bp + expansion_len >= end) {
tcpd_warn("percent_x: expansion too long: %.30s...", result);
sleep(5);
exit(0);
}
memcpy(bp, expansion, expansion_len);
bp += expansion_len;
}
*bp = 0;
return (result);
}

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syslog 1 0
tcpd_warn 0 0
tcpd_jump 0 0

103
contrib/tcp_wrappers/ptx.c Normal file
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/*
* The Dynix/PTX TLI implementation is not quite compatible with System V
* Release 4. Some important functions are not present so we are limited to
* IP-based services.
*
* Diagnostics are reported through syslog(3).
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) ptx.c 1.3 94/12/28 17:42:38";
#endif
#ifdef PTX
/* System libraries. */
#include <sys/types.h>
#include <sys/tiuser.h>
#include <sys/socket.h>
#include <stropts.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>
#include <syslog.h>
/* Local stuff. */
#include "tcpd.h"
/* Forward declarations. */
static void ptx_sink();
/* tli_host - determine TLI endpoint info, PTX version */
void tli_host(request)
struct request_info *request;
{
static struct sockaddr_in client;
static struct sockaddr_in server;
/*
* getpeerinaddr() was suggested by someone at Sequent. It seems to work
* with connection-oriented (TCP) services such as rlogind and telnetd,
* but it returns 0.0.0.0 with datagram (UDP) services. No problem: UDP
* needs special treatment anyway, in case we must refuse service.
*/
if (getpeerinaddr(request->fd, &client, sizeof(client)) == 0
&& client.sin_addr.s_addr != 0) {
request->client->sin = &client;
if (getmyinaddr(request->fd, &server, sizeof(server)) == 0) {
request->server->sin = &server;
} else {
tcpd_warn("warning: getmyinaddr: %m");
}
sock_methods(request);
} else {
/*
* Another suggestion was to temporarily switch to the socket
* interface, identify the endpoint addresses with socket calls, then
* to switch back to TLI. This seems to works OK with UDP services,
* which is exactly what we should be looking at right now.
*/
#define SWAP_MODULE(f, old, new) (ioctl(f, I_POP, old), ioctl(f, I_PUSH, new))
if (SWAP_MODULE(request->fd, "timod", "sockmod") != 0)
tcpd_warn("replace timod by sockmod: %m");
sock_host(request);
if (SWAP_MODULE(request->fd, "sockmod", "timod") != 0)
tcpd_warn("replace sockmod by timod: %m");
if (request->sink != 0)
request->sink = ptx_sink;
}
}
/* ptx_sink - absorb unreceived IP datagram */
static void ptx_sink(fd)
int fd;
{
char buf[BUFSIZ];
struct sockaddr sa;
int size = sizeof(sa);
/*
* Eat up the not-yet received datagram. Where needed, switch to the
* socket programming interface.
*/
if (ioctl(fd, I_FIND, "timod") != 0)
ioctl(fd, I_POP, "timod");
if (ioctl(fd, I_FIND, "sockmod") == 0)
ioctl(fd, I_PUSH, "sockmod");
(void) recvfrom(fd, buf, sizeof(buf), 0, &sa, &size);
}
#endif /* PTX */

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/*
* refuse() reports a refused connection, and takes the consequences: in
* case of a datagram-oriented service, the unread datagram is taken from
* the input queue (or inetd would see the same datagram again and again);
* the program is terminated.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) refuse.c 1.5 94/12/28 17:42:39";
#endif
/* System libraries. */
#include <stdio.h>
#include <syslog.h>
/* Local stuff. */
#include "tcpd.h"
/* refuse - refuse request */
void refuse(request)
struct request_info *request;
{
syslog(deny_severity, "refused connect from %s", eval_client(request));
clean_exit(request);
/* NOTREACHED */
}

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/*
* rfc931() speaks a common subset of the RFC 931, AUTH, TAP, IDENT and RFC
* 1413 protocols. It queries an RFC 931 etc. compatible daemon on a remote
* host to look up the owner of a connection. The information should not be
* used for authentication purposes. This routine intercepts alarm signals.
*
* Diagnostics are reported through syslog(3).
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) rfc931.c 1.10 95/01/02 16:11:34";
#endif
/* System libraries. */
#include <stdio.h>
#include <syslog.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <setjmp.h>
#include <signal.h>
#include <string.h>
/* Local stuff. */
#include "tcpd.h"
#define RFC931_PORT 113 /* Semi-well-known port */
#define ANY_PORT 0 /* Any old port will do */
int rfc931_timeout = RFC931_TIMEOUT;/* Global so it can be changed */
static jmp_buf timebuf;
/* fsocket - open stdio stream on top of socket */
static FILE *fsocket(domain, type, protocol)
int domain;
int type;
int protocol;
{
int s;
FILE *fp;
if ((s = socket(domain, type, protocol)) < 0) {
tcpd_warn("socket: %m");
return (0);
} else {
if ((fp = fdopen(s, "r+")) == 0) {
tcpd_warn("fdopen: %m");
close(s);
}
return (fp);
}
}
/* timeout - handle timeouts */
static void timeout(sig)
int sig;
{
longjmp(timebuf, sig);
}
/* rfc931 - return remote user name, given socket structures */
void rfc931(rmt_sin, our_sin, dest)
struct sockaddr_in *rmt_sin;
struct sockaddr_in *our_sin;
char *dest;
{
unsigned rmt_port;
unsigned our_port;
struct sockaddr_in rmt_query_sin;
struct sockaddr_in our_query_sin;
char user[256]; /* XXX */
char buffer[512]; /* XXX */
char *cp;
char *result = unknown;
FILE *fp;
/*
* Use one unbuffered stdio stream for writing to and for reading from
* the RFC931 etc. server. This is done because of a bug in the SunOS
* 4.1.x stdio library. The bug may live in other stdio implementations,
* too. When we use a single, buffered, bidirectional stdio stream ("r+"
* or "w+" mode) we read our own output. Such behaviour would make sense
* with resources that support random-access operations, but not with
* sockets.
*/
if ((fp = fsocket(AF_INET, SOCK_STREAM, 0)) != 0) {
setbuf(fp, (char *) 0);
/*
* Set up a timer so we won't get stuck while waiting for the server.
*/
if (setjmp(timebuf) == 0) {
signal(SIGALRM, timeout);
alarm(rfc931_timeout);
/*
* Bind the local and remote ends of the query socket to the same
* IP addresses as the connection under investigation. We go
* through all this trouble because the local or remote system
* might have more than one network address. The RFC931 etc.
* client sends only port numbers; the server takes the IP
* addresses from the query socket.
*/
our_query_sin = *our_sin;
our_query_sin.sin_port = htons(ANY_PORT);
rmt_query_sin = *rmt_sin;
rmt_query_sin.sin_port = htons(RFC931_PORT);
if (bind(fileno(fp), (struct sockaddr *) & our_query_sin,
sizeof(our_query_sin)) >= 0 &&
connect(fileno(fp), (struct sockaddr *) & rmt_query_sin,
sizeof(rmt_query_sin)) >= 0) {
/*
* Send query to server. Neglect the risk that a 13-byte
* write would have to be fragmented by the local system and
* cause trouble with buggy System V stdio libraries.
*/
fprintf(fp, "%u,%u\r\n",
ntohs(rmt_sin->sin_port),
ntohs(our_sin->sin_port));
fflush(fp);
/*
* Read response from server. Use fgets()/sscanf() so we can
* work around System V stdio libraries that incorrectly
* assume EOF when a read from a socket returns less than
* requested.
*/
if (fgets(buffer, sizeof(buffer), fp) != 0
&& ferror(fp) == 0 && feof(fp) == 0
&& sscanf(buffer, "%u , %u : USERID :%*[^:]:%255s",
&rmt_port, &our_port, user) == 3
&& ntohs(rmt_sin->sin_port) == rmt_port
&& ntohs(our_sin->sin_port) == our_port) {
/*
* Strip trailing carriage return. It is part of the
* protocol, not part of the data.
*/
if (cp = strchr(user, '\r'))
*cp = 0;
result = user;
}
}
alarm(0);
}
fclose(fp);
}
STRN_CPY(dest, result, STRING_LENGTH);
}

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/*
* safe_finger - finger client wrapper that protects against nasty stuff
* from finger servers. Use this program for automatic reverse finger
* probes, not the raw finger command.
*
* Build with: cc -o safe_finger safe_finger.c
*
* The problem: some programs may react to stuff in the first column. Other
* programs may get upset by thrash anywhere on a line. File systems may
* fill up as the finger server keeps sending data. Text editors may bomb
* out on extremely long lines. The finger server may take forever because
* it is somehow wedged. The code below takes care of all this badness.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) safe_finger.c 1.4 94/12/28 17:42:41";
#endif
/* System libraries */
#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
#include <stdio.h>
#include <ctype.h>
#include <pwd.h>
extern void exit();
/* Local stuff */
char path[] = "PATH=/bin:/usr/bin:/usr/ucb:/usr/bsd:/etc:/usr/etc:/usr/sbin";
#define TIME_LIMIT 60 /* Do not keep listinging forever */
#define INPUT_LENGTH 100000 /* Do not keep listinging forever */
#define LINE_LENGTH 128 /* Editors can choke on long lines */
#define FINGER_PROGRAM "finger" /* Most, if not all, UNIX systems */
#define UNPRIV_NAME "nobody" /* Preferred privilege level */
#define UNPRIV_UGID 32767 /* Default uid and gid */
int finger_pid;
void cleanup(sig)
int sig;
{
kill(finger_pid, SIGKILL);
exit(0);
}
main(argc, argv)
int argc;
char **argv;
{
int c;
int line_length = 0;
int finger_status;
int wait_pid;
int input_count = 0;
struct passwd *pwd;
/*
* First of all, let's don't run with superuser privileges.
*/
if (getuid() == 0 || geteuid() == 0) {
if ((pwd = getpwnam(UNPRIV_NAME)) && pwd->pw_uid > 0) {
setgid(pwd->pw_gid);
setuid(pwd->pw_uid);
} else {
setgid(UNPRIV_UGID);
setuid(UNPRIV_UGID);
}
}
/*
* Redirect our standard input through the raw finger command.
*/
if (putenv(path)) {
fprintf(stderr, "%s: putenv: out of memory", argv[0]);
exit(1);
}
argv[0] = FINGER_PROGRAM;
finger_pid = pipe_stdin(argv);
/*
* Don't wait forever (Peter Wemm <peter@gecko.DIALix.oz.au>).
*/
signal(SIGALRM, cleanup);
(void) alarm(TIME_LIMIT);
/*
* Main filter loop.
*/
while ((c = getchar()) != EOF) {
if (input_count++ >= INPUT_LENGTH) { /* don't listen forever */
fclose(stdin);
printf("\n\n Input truncated to %d bytes...\n", input_count - 1);
break;
}
if (c == '\n') { /* good: end of line */
putchar(c);
line_length = 0;
} else {
if (line_length >= LINE_LENGTH) { /* force end of line */
printf("\\\n");
line_length = 0;
}
if (line_length == 0) { /* protect left margin */
putchar(' ');
line_length++;
}
if (isascii(c) && (isprint(c) || isspace(c))) { /* text */
if (c == '\\') {
putchar(c);
line_length++;
}
putchar(c);
line_length++;
} else { /* quote all other thash */
printf("\\%03o", c & 0377);
line_length += 4;
}
}
}
/*
* Wait until the finger child process has terminated and account for its
* exit status. Which will always be zero on most systems.
*/
while ((wait_pid = wait(&finger_status)) != -1 && wait_pid != finger_pid)
/* void */ ;
return (wait_pid != finger_pid || finger_status != 0);
}
/* perror_exit - report system error text and terminate */
void perror_exit(text)
char *text;
{
perror(text);
exit(1);
}
/* pipe_stdin - pipe stdin through program (from my ANSI to OLD C converter) */
int pipe_stdin(argv)
char **argv;
{
int pipefds[2];
int pid;
int i;
struct stat st;
/*
* The code that sets up the pipe requires that file descriptors 0,1,2
* are already open. All kinds of mysterious things will happen if that
* is not the case. The following loops makes sure that descriptors 0,1,2
* are set up properly.
*/
for (i = 0; i < 3; i++) {
if (fstat(i, &st) == -1 && open("/dev/null", 2) != i)
perror_exit("open /dev/null");
}
/*
* Set up the pipe that interposes the command into our standard input
* stream.
*/
if (pipe(pipefds))
perror_exit("pipe");
switch (pid = fork()) {
case -1: /* error */
perror_exit("fork");
/* NOTREACHED */
case 0: /* child */
(void) close(pipefds[0]); /* close reading end */
(void) close(1); /* connect stdout to pipe */
if (dup(pipefds[1]) != 1)
perror_exit("dup");
(void) close(pipefds[1]); /* close redundant fd */
(void) execvp(argv[0], argv);
perror_exit(argv[0]);
/* NOTREACHED */
default: /* parent */
(void) close(pipefds[1]); /* close writing end */
(void) close(0); /* connect stdin to pipe */
if (dup(pipefds[0]) != 0)
perror_exit("dup");
(void) close(pipefds[0]); /* close redundant fd */
return (pid);
}
}

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/*
* Routines for testing only. Not really industrial strength.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccs_id[] = "@(#) scaffold.c 1.6 97/03/21 19:27:24";
#endif
/* System libraries. */
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <syslog.h>
#include <setjmp.h>
#include <string.h>
#ifndef INADDR_NONE
#define INADDR_NONE (-1) /* XXX should be 0xffffffff */
#endif
extern char *malloc();
/* Application-specific. */
#include "tcpd.h"
#include "scaffold.h"
/*
* These are referenced by the options module and by rfc931.c.
*/
int allow_severity = SEVERITY;
int deny_severity = LOG_WARNING;
int rfc931_timeout = RFC931_TIMEOUT;
/* dup_hostent - create hostent in one memory block */
static struct hostent *dup_hostent(hp)
struct hostent *hp;
{
struct hostent_block {
struct hostent host;
char *addr_list[1];
};
struct hostent_block *hb;
int count;
char *data;
char *addr;
for (count = 0; hp->h_addr_list[count] != 0; count++)
/* void */ ;
if ((hb = (struct hostent_block *) malloc(sizeof(struct hostent_block)
+ (hp->h_length + sizeof(char *)) * count)) == 0) {
fprintf(stderr, "Sorry, out of memory\n");
exit(1);
}
memset((char *) &hb->host, 0, sizeof(hb->host));
hb->host.h_length = hp->h_length;
hb->host.h_addr_list = hb->addr_list;
hb->host.h_addr_list[count] = 0;
data = (char *) (hb->host.h_addr_list + count + 1);
for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
hb->host.h_addr_list[count] = data + hp->h_length * count;
memcpy(hb->host.h_addr_list[count], addr, hp->h_length);
}
return (&hb->host);
}
/* find_inet_addr - find all addresses for this host, result to free() */
struct hostent *find_inet_addr(host)
char *host;
{
struct in_addr addr;
struct hostent *hp;
static struct hostent h;
static char *addr_list[2];
/*
* Host address: translate it to internal form.
*/
if ((addr.s_addr = dot_quad_addr(host)) != INADDR_NONE) {
h.h_addr_list = addr_list;
h.h_addr_list[0] = (char *) &addr;
h.h_length = sizeof(addr);
return (dup_hostent(&h));
}
/*
* Map host name to a series of addresses. Watch out for non-internet
* forms or aliases. The NOT_INADDR() is here in case gethostbyname() has
* been "enhanced" to accept numeric addresses. Make a copy of the
* address list so that later gethostbyXXX() calls will not clobber it.
*/
if (NOT_INADDR(host) == 0) {
tcpd_warn("%s: not an internet address", host);
return (0);
}
if ((hp = gethostbyname(host)) == 0) {
tcpd_warn("%s: host not found", host);
return (0);
}
if (hp->h_addrtype != AF_INET) {
tcpd_warn("%d: not an internet host", hp->h_addrtype);
return (0);
}
if (STR_NE(host, hp->h_name)) {
tcpd_warn("%s: hostname alias", host);
tcpd_warn("(official name: %.*s)", STRING_LENGTH, hp->h_name);
}
return (dup_hostent(hp));
}
/* check_dns - give each address thorough workout, return address count */
int check_dns(host)
char *host;
{
struct request_info request;
struct sockaddr_in sin;
struct hostent *hp;
int count;
char *addr;
if ((hp = find_inet_addr(host)) == 0)
return (0);
request_init(&request, RQ_CLIENT_SIN, &sin, 0);
sock_methods(&request);
memset((char *) &sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
memcpy((char *) &sin.sin_addr, addr, sizeof(sin.sin_addr));
/*
* Force host name and address conversions. Use the request structure
* as a cache. Detect hostname lookup problems. Any name/name or
* name/address conflicts will be reported while eval_hostname() does
* its job.
*/
request_set(&request, RQ_CLIENT_ADDR, "", RQ_CLIENT_NAME, "", 0);
if (STR_EQ(eval_hostname(request.client), unknown))
tcpd_warn("host address %s->name lookup failed",
eval_hostaddr(request.client));
}
free((char *) hp);
return (count);
}
/* dummy function to intercept the real shell_cmd() */
/* ARGSUSED */
void shell_cmd(command)
char *command;
{
if (hosts_access_verbose)
printf("command: %s", command);
}
/* dummy function to intercept the real clean_exit() */
/* ARGSUSED */
void clean_exit(request)
struct request_info *request;
{
exit(0);
}
/* dummy function to intercept the real rfc931() */
/* ARGSUSED */
void rfc931(request)
struct request_info *request;
{
strcpy(request->user, unknown);
}
/* check_path - examine accessibility */
int check_path(path, st)
char *path;
struct stat *st;
{
struct stat stbuf;
char buf[BUFSIZ];
if (stat(path, st) < 0)
return (-1);
#ifdef notdef
if (st->st_uid != 0)
tcpd_warn("%s: not owned by root", path);
if (st->st_mode & 020)
tcpd_warn("%s: group writable", path);
#endif
if (st->st_mode & 002)
tcpd_warn("%s: world writable", path);
if (path[0] == '/' && path[1] != 0) {
strrchr(strcpy(buf, path), '/')[0] = 0;
(void) check_path(buf[0] ? buf : "/", &stbuf);
}
return (0);
}

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/*
* @(#) scaffold.h 1.3 94/12/31 18:19:19
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
extern struct hostent *find_inet_addr();
extern int check_dns();
extern int check_path();

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/*
* Some systems do not have setenv(). This one is modeled after 4.4 BSD, but
* is implemented in terms of portable primitives only: getenv(), putenv()
* and malloc(). It should therefore be safe to use on every UNIX system.
*
* If clobber == 0, do not overwrite an existing variable.
*
* Returns nonzero if memory allocation fails.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) setenv.c 1.1 93/03/07 22:47:58";
#endif
/* setenv - update or insert environment (name,value) pair */
int setenv(name, value, clobber)
char *name;
char *value;
int clobber;
{
char *malloc();
char *getenv();
char *cp;
if (clobber == 0 && getenv(name) != 0)
return (0);
if ((cp = malloc(strlen(name) + strlen(value) + 2)) == 0)
return (1);
sprintf(cp, "%s=%s", name, value);
return (putenv(cp));
}

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/*
* shell_cmd() takes a shell command after %<character> substitutions. The
* command is executed by a /bin/sh child process, with standard input,
* standard output and standard error connected to /dev/null.
*
* Diagnostics are reported through syslog(3).
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) shell_cmd.c 1.5 94/12/28 17:42:44";
#endif
/* System libraries. */
#include <sys/types.h>
#include <sys/param.h>
#include <signal.h>
#include <stdio.h>
#include <syslog.h>
#include <string.h>
extern void exit();
/* Local stuff. */
#include "tcpd.h"
/* Forward declarations. */
static void do_child();
/* shell_cmd - execute shell command */
void shell_cmd(command)
char *command;
{
int child_pid;
int wait_pid;
/*
* Most of the work is done within the child process, to minimize the
* risk of damage to the parent.
*/
switch (child_pid = fork()) {
case -1: /* error */
tcpd_warn("cannot fork: %m");
break;
case 00: /* child */
do_child(command);
/* NOTREACHED */
default: /* parent */
while ((wait_pid = wait((int *) 0)) != -1 && wait_pid != child_pid)
/* void */ ;
}
}
/* do_child - exec command with { stdin, stdout, stderr } to /dev/null */
static void do_child(command)
char *command;
{
char *error;
int tmp_fd;
/*
* Systems with POSIX sessions may send a SIGHUP to grandchildren if the
* child exits first. This is sick, sessions were invented for terminals.
*/
signal(SIGHUP, SIG_IGN);
/* Set up new stdin, stdout, stderr, and exec the shell command. */
for (tmp_fd = 0; tmp_fd < 3; tmp_fd++)
(void) close(tmp_fd);
if (open("/dev/null", 2) != 0) {
error = "open /dev/null: %m";
} else if (dup(0) != 1 || dup(0) != 2) {
error = "dup: %m";
} else {
(void) execl("/bin/sh", "sh", "-c", command, (char *) 0);
error = "execl /bin/sh: %m";
}
/* Something went wrong. We MUST terminate the child process. */
tcpd_warn(error);
_exit(0);
}

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/*
* This module determines the type of socket (datagram, stream), the client
* socket address and port, the server socket address and port. In addition,
* it provides methods to map a transport address to a printable host name
* or address. Socket address information results are in static memory.
*
* The result from the hostname lookup method is STRING_PARANOID when a host
* pretends to have someone elses name, or when a host name is available but
* could not be verified.
*
* When lookup or conversion fails the result is set to STRING_UNKNOWN.
*
* Diagnostics are reported through syslog(3).
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) socket.c 1.15 97/03/21 19:27:24";
#endif
/* System libraries. */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>
#include <syslog.h>
#include <string.h>
extern char *inet_ntoa();
/* Local stuff. */
#include "tcpd.h"
/* Forward declarations. */
static void sock_sink();
#ifdef APPEND_DOT
/*
* Speed up DNS lookups by terminating the host name with a dot. Should be
* done with care. The speedup can give problems with lookups from sources
* that lack DNS-style trailing dot magic, such as local files or NIS maps.
*/
static struct hostent *gethostbyname_dot(name)
char *name;
{
char dot_name[MAXHOSTNAMELEN + 1];
/*
* Don't append dots to unqualified names. Such names are likely to come
* from local hosts files or from NIS.
*/
if (strchr(name, '.') == 0 || strlen(name) >= MAXHOSTNAMELEN - 1) {
return (gethostbyname(name));
} else {
sprintf(dot_name, "%s.", name);
return (gethostbyname(dot_name));
}
}
#define gethostbyname gethostbyname_dot
#endif
/* sock_host - look up endpoint addresses and install conversion methods */
void sock_host(request)
struct request_info *request;
{
static struct sockaddr_in client;
static struct sockaddr_in server;
int len;
char buf[BUFSIZ];
int fd = request->fd;
sock_methods(request);
/*
* Look up the client host address. Hal R. Brand <BRAND@addvax.llnl.gov>
* suggested how to get the client host info in case of UDP connections:
* peek at the first message without actually looking at its contents. We
* really should verify that client.sin_family gets the value AF_INET,
* but this program has already caused too much grief on systems with
* broken library code.
*/
len = sizeof(client);
if (getpeername(fd, (struct sockaddr *) & client, &len) < 0) {
request->sink = sock_sink;
len = sizeof(client);
if (recvfrom(fd, buf, sizeof(buf), MSG_PEEK,
(struct sockaddr *) & client, &len) < 0) {
tcpd_warn("can't get client address: %m");
return; /* give up */
}
#ifdef really_paranoid
memset(buf, 0 sizeof(buf));
#endif
}
request->client->sin = &client;
/*
* Determine the server binding. This is used for client username
* lookups, and for access control rules that trigger on the server
* address or name.
*/
len = sizeof(server);
if (getsockname(fd, (struct sockaddr *) & server, &len) < 0) {
tcpd_warn("getsockname: %m");
return;
}
request->server->sin = &server;
}
/* sock_hostaddr - map endpoint address to printable form */
void sock_hostaddr(host)
struct host_info *host;
{
struct sockaddr_in *sin = host->sin;
if (sin != 0)
STRN_CPY(host->addr, inet_ntoa(sin->sin_addr), sizeof(host->addr));
}
/* sock_hostname - map endpoint address to host name */
void sock_hostname(host)
struct host_info *host;
{
struct sockaddr_in *sin = host->sin;
struct hostent *hp;
int i;
/*
* On some systems, for example Solaris 2.3, gethostbyaddr(0.0.0.0) does
* not fail. Instead it returns "INADDR_ANY". Unfortunately, this does
* not work the other way around: gethostbyname("INADDR_ANY") fails. We
* have to special-case 0.0.0.0, in order to avoid false alerts from the
* host name/address checking code below.
*/
if (sin != 0 && sin->sin_addr.s_addr != 0
&& (hp = gethostbyaddr((char *) &(sin->sin_addr),
sizeof(sin->sin_addr), AF_INET)) != 0) {
STRN_CPY(host->name, hp->h_name, sizeof(host->name));
/*
* Verify that the address is a member of the address list returned
* by gethostbyname(hostname).
*
* Verify also that gethostbyaddr() and gethostbyname() return the same
* hostname, or rshd and rlogind may still end up being spoofed.
*
* On some sites, gethostbyname("localhost") returns "localhost.domain".
* This is a DNS artefact. We treat it as a special case. When we
* can't believe the address list from gethostbyname("localhost")
* we're in big trouble anyway.
*/
if ((hp = gethostbyname(host->name)) == 0) {
/*
* Unable to verify that the host name matches the address. This
* may be a transient problem or a botched name server setup.
*/
tcpd_warn("can't verify hostname: gethostbyname(%s) failed",
host->name);
} else if (STR_NE(host->name, hp->h_name)
&& STR_NE(host->name, "localhost")) {
/*
* The gethostbyaddr() and gethostbyname() calls did not return
* the same hostname. This could be a nameserver configuration
* problem. It could also be that someone is trying to spoof us.
*/
tcpd_warn("host name/name mismatch: %s != %.*s",
host->name, STRING_LENGTH, hp->h_name);
} else {
/*
* The address should be a member of the address list returned by
* gethostbyname(). We should first verify that the h_addrtype
* field is AF_INET, but this program has already caused too much
* grief on systems with broken library code.
*/
for (i = 0; hp->h_addr_list[i]; i++) {
if (memcmp(hp->h_addr_list[i],
(char *) &sin->sin_addr,
sizeof(sin->sin_addr)) == 0)
return; /* name is good, keep it */
}
/*
* The host name does not map to the initial address. Perhaps
* someone has messed up. Perhaps someone compromised a name
* server.
*/
tcpd_warn("host name/address mismatch: %s != %.*s",
inet_ntoa(sin->sin_addr), STRING_LENGTH, hp->h_name);
}
strcpy(host->name, paranoid); /* name is bad, clobber it */
}
}
/* sock_sink - absorb unreceived IP datagram */
static void sock_sink(fd)
int fd;
{
char buf[BUFSIZ];
struct sockaddr_in sin;
int size = sizeof(sin);
/*
* Eat up the not-yet received datagram. Some systems insist on a
* non-zero source address argument in the recvfrom() call below.
*/
(void) recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr *) & sin, &size);
}

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@ -0,0 +1,94 @@
/*
* Copyright (c) 1987 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strcasecmp.c 5.6 (Berkeley) 6/27/88";
#endif /* LIBC_SCCS and not lint */
/* Some environments don't define u_char -- WZV */
#if 0
#include <sys/types.h>
#else
typedef unsigned char u_char;
#endif
/*
* This array is designed for mapping upper and lower case letter
* together for a case independent comparison. The mappings are
* based upon ascii character sequences.
*/
static u_char charmap[] = {
'\000', '\001', '\002', '\003', '\004', '\005', '\006', '\007',
'\010', '\011', '\012', '\013', '\014', '\015', '\016', '\017',
'\020', '\021', '\022', '\023', '\024', '\025', '\026', '\027',
'\030', '\031', '\032', '\033', '\034', '\035', '\036', '\037',
'\040', '\041', '\042', '\043', '\044', '\045', '\046', '\047',
'\050', '\051', '\052', '\053', '\054', '\055', '\056', '\057',
'\060', '\061', '\062', '\063', '\064', '\065', '\066', '\067',
'\070', '\071', '\072', '\073', '\074', '\075', '\076', '\077',
'\100', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
'\170', '\171', '\172', '\133', '\134', '\135', '\136', '\137',
'\140', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
'\170', '\171', '\172', '\173', '\174', '\175', '\176', '\177',
'\200', '\201', '\202', '\203', '\204', '\205', '\206', '\207',
'\210', '\211', '\212', '\213', '\214', '\215', '\216', '\217',
'\220', '\221', '\222', '\223', '\224', '\225', '\226', '\227',
'\230', '\231', '\232', '\233', '\234', '\235', '\236', '\237',
'\240', '\241', '\242', '\243', '\244', '\245', '\246', '\247',
'\250', '\251', '\252', '\253', '\254', '\255', '\256', '\257',
'\260', '\261', '\262', '\263', '\264', '\265', '\266', '\267',
'\270', '\271', '\272', '\273', '\274', '\275', '\276', '\277',
'\300', '\341', '\342', '\343', '\344', '\345', '\346', '\347',
'\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357',
'\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367',
'\370', '\371', '\372', '\333', '\334', '\335', '\336', '\337',
'\340', '\341', '\342', '\343', '\344', '\345', '\346', '\347',
'\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357',
'\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367',
'\370', '\371', '\372', '\373', '\374', '\375', '\376', '\377',
};
strcasecmp(s1, s2)
char *s1, *s2;
{
register u_char *cm = charmap,
*us1 = (u_char *)s1,
*us2 = (u_char *)s2;
while (cm[*us1] == cm[*us2++])
if (*us1++ == '\0')
return(0);
return(cm[*us1] - cm[*--us2]);
}
strncasecmp(s1, s2, n)
char *s1, *s2;
register int n;
{
register u_char *cm = charmap,
*us1 = (u_char *)s1,
*us2 = (u_char *)s2;
while (--n >= 0 && cm[*us1] == cm[*us2++])
if (*us1++ == '\0')
return(0);
return(n < 0 ? 0 : cm[*us1] - cm[*--us2]);
}

178
contrib/tcp_wrappers/tcpd.8 Normal file
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.TH TCPD 8
.SH NAME
tcpd \- access control facility for internet services
.SH DESCRIPTION
.PP
The \fItcpd\fR program can be set up to monitor incoming requests for
\fItelnet\fR, \fIfinger\fR, \fIftp\fR, \fIexec\fR, \fIrsh\fR,
\fIrlogin\fR, \fItftp\fR, \fItalk\fR, \fIcomsat\fR and other services
that have a one-to-one mapping onto executable files.
.PP
The program supports both 4.3BSD-style sockets and System V.4-style
TLI. Functionality may be limited when the protocol underneath TLI is
not an internet protocol.
.PP
Operation is as follows: whenever a request for service arrives, the
\fIinetd\fP daemon is tricked into running the \fItcpd\fP program
instead of the desired server. \fItcpd\fP logs the request and does
some additional checks. When all is well, \fItcpd\fP runs the
appropriate server program and goes away.
.PP
Optional features are: pattern-based access control, client username
lookups with the RFC 931 etc. protocol, protection against hosts that
pretend to have someone elses host name, and protection against hosts
that pretend to have someone elses network address.
.SH LOGGING
Connections that are monitored by
.I tcpd
are reported through the \fIsyslog\fR(3) facility. Each record contains
a time stamp, the client host name and the name of the requested
service. The information can be useful to detect unwanted activities,
especially when logfile information from several hosts is merged.
.PP
In order to find out where your logs are going, examine the syslog
configuration file, usually /etc/syslog.conf.
.SH ACCESS CONTROL
Optionally,
.I tcpd
supports a simple form of access control that is based on pattern
matching. The access-control software provides hooks for the execution
of shell commands when a pattern fires. For details, see the
\fIhosts_access\fR(5) manual page.
.SH HOST NAME VERIFICATION
The authentication scheme of some protocols (\fIrlogin, rsh\fR) relies
on host names. Some implementations believe the host name that they get
from any random name server; other implementations are more careful but
use a flawed algorithm.
.PP
.I tcpd
verifies the client host name that is returned by the address->name DNS
server by looking at the host name and address that are returned by the
name->address DNS server. If any discrepancy is detected,
.I tcpd
concludes that it is dealing with a host that pretends to have someone
elses host name.
.PP
If the sources are compiled with -DPARANOID,
.I tcpd
will drop the connection in case of a host name/address mismatch.
Otherwise, the hostname can be matched with the \fIPARANOID\fR wildcard,
after which suitable action can be taken.
.SH HOST ADDRESS SPOOFING
Optionally,
.I tcpd
disables source-routing socket options on every connection that it
deals with. This will take care of most attacks from hosts that pretend
to have an address that belongs to someone elses network. UDP services
do not benefit from this protection. This feature must be turned on
at compile time.
.SH RFC 931
When RFC 931 etc. lookups are enabled (compile-time option) \fItcpd\fR
will attempt to establish the name of the client user. This will
succeed only if the client host runs an RFC 931-compliant daemon.
Client user name lookups will not work for datagram-oriented
connections, and may cause noticeable delays in the case of connections
from PCs.
.SH EXAMPLES
The details of using \fItcpd\fR depend on pathname information that was
compiled into the program.
.SH EXAMPLE 1
This example applies when \fItcpd\fR expects that the original network
daemons will be moved to an "other" place.
.PP
In order to monitor access to the \fIfinger\fR service, move the
original finger daemon to the "other" place and install tcpd in the
place of the original finger daemon. No changes are required to
configuration files.
.nf
.sp
.in +5
# mkdir /other/place
# mv /usr/etc/in.fingerd /other/place
# cp tcpd /usr/etc/in.fingerd
.fi
.PP
The example assumes that the network daemons live in /usr/etc. On some
systems, network daemons live in /usr/sbin or in /usr/libexec, or have
no `in.\' prefix to their name.
.SH EXAMPLE 2
This example applies when \fItcpd\fR expects that the network daemons
are left in their original place.
.PP
In order to monitor access to the \fIfinger\fR service, perform the
following edits on the \fIinetd\fR configuration file (usually
\fI/etc/inetd.conf\fR or \fI/etc/inet/inetd.conf\fR):
.nf
.sp
.ti +5
finger stream tcp nowait nobody /usr/etc/in.fingerd in.fingerd
.sp
becomes:
.sp
.ti +5
finger stream tcp nowait nobody /some/where/tcpd in.fingerd
.sp
.fi
.PP
The example assumes that the network daemons live in /usr/etc. On some
systems, network daemons live in /usr/sbin or in /usr/libexec, the
daemons have no `in.\' prefix to their name, or there is no userid
field in the inetd configuration file.
.PP
Similar changes will be needed for the other services that are to be
covered by \fItcpd\fR. Send a `kill -HUP\' to the \fIinetd\fR(8)
process to make the changes effective. AIX users may also have to
execute the `inetimp\' command.
.SH EXAMPLE 3
In the case of daemons that do not live in a common directory ("secret"
or otherwise), edit the \fIinetd\fR configuration file so that it
specifies an absolute path name for the process name field. For example:
.nf
.sp
ntalk dgram udp wait root /some/where/tcpd /usr/local/lib/ntalkd
.sp
.fi
.PP
Only the last component (ntalkd) of the pathname will be used for
access control and logging.
.SH BUGS
Some UDP (and RPC) daemons linger around for a while after they have
finished their work, in case another request comes in. In the inetd
configuration file these services are registered with the \fIwait\fR
option. Only the request that started such a daemon will be logged.
.PP
The program does not work with RPC services over TCP. These services
are registered as \fIrpc/tcp\fR in the inetd configuration file. The
only non-trivial service that is affected by this limitation is
\fIrexd\fR, which is used by the \fIon(1)\fR command. This is no great
loss. On most systems, \fIrexd\fR is less secure than a wildcard in
/etc/hosts.equiv.
.PP
RPC broadcast requests (for example: \fIrwall, rup, rusers\fR) always
appear to come from the responding host. What happens is that the
client broadcasts the request to all \fIportmap\fR daemons on its
network; each \fIportmap\fR daemon forwards the request to a local
daemon. As far as the \fIrwall\fR etc. daemons know, the request comes
from the local host.
.SH FILES
.PP
The default locations of the host access control tables are:
.PP
/etc/hosts.allow
.br
/etc/hosts.deny
.SH SEE ALSO
.na
.nf
hosts_access(5), format of the tcpd access control tables.
syslog.conf(5), format of the syslogd control file.
inetd.conf(5), format of the inetd control file.
.SH AUTHORS
.na
.nf
Wietse Venema (wietse@wzv.win.tue.nl),
Department of Mathematics and Computing Science,
Eindhoven University of Technology
Den Dolech 2, P.O. Box 513,
5600 MB Eindhoven, The Netherlands
\" @(#) tcpd.8 1.5 96/02/21 16:39:16

129
contrib/tcp_wrappers/tcpd.c Normal file
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/*
* General front end for stream and datagram IP services. This program logs
* the remote host name and then invokes the real daemon. For example,
* install as /usr/etc/{tftpd,fingerd,telnetd,ftpd,rlogind,rshd,rexecd},
* after saving the real daemons in the directory specified with the
* REAL_DAEMON_DIR macro. This arrangement requires that the network daemons
* are started by inetd or something similar. Connections and diagnostics
* are logged through syslog(3).
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) tcpd.c 1.10 96/02/11 17:01:32";
#endif
/* System libraries. */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <syslog.h>
#include <string.h>
#ifndef MAXPATHNAMELEN
#define MAXPATHNAMELEN BUFSIZ
#endif
#ifndef STDIN_FILENO
#define STDIN_FILENO 0
#endif
/* Local stuff. */
#include "patchlevel.h"
#include "tcpd.h"
int allow_severity = SEVERITY; /* run-time adjustable */
int deny_severity = LOG_WARNING; /* ditto */
main(argc, argv)
int argc;
char **argv;
{
struct request_info request;
char path[MAXPATHNAMELEN];
/* Attempt to prevent the creation of world-writable files. */
#ifdef DAEMON_UMASK
umask(DAEMON_UMASK);
#endif
/*
* If argv[0] is an absolute path name, ignore REAL_DAEMON_DIR, and strip
* argv[0] to its basename.
*/
if (argv[0][0] == '/') {
strcpy(path, argv[0]);
argv[0] = strrchr(argv[0], '/') + 1;
} else {
sprintf(path, "%s/%s", REAL_DAEMON_DIR, argv[0]);
}
/*
* Open a channel to the syslog daemon. Older versions of openlog()
* require only two arguments.
*/
#ifdef LOG_MAIL
(void) openlog(argv[0], LOG_PID, FACILITY);
#else
(void) openlog(argv[0], LOG_PID);
#endif
/*
* Find out the endpoint addresses of this conversation. Host name
* lookups and double checks will be done on demand.
*/
request_init(&request, RQ_DAEMON, argv[0], RQ_FILE, STDIN_FILENO, 0);
fromhost(&request);
/*
* Optionally look up and double check the remote host name. Sites
* concerned with security may choose to refuse connections from hosts
* that pretend to have someone elses host name.
*/
#ifdef PARANOID
if (STR_EQ(eval_hostname(request.client), paranoid))
refuse(&request);
#endif
/*
* The BSD rlogin and rsh daemons that came out after 4.3 BSD disallow
* socket options at the IP level. They do so for a good reason.
* Unfortunately, we cannot use this with SunOS 4.1.x because the
* getsockopt() system call can panic the system.
*/
#ifdef KILL_IP_OPTIONS
fix_options(&request);
#endif
/*
* Check whether this host can access the service in argv[0]. The
* access-control code invokes optional shell commands as specified in
* the access-control tables.
*/
#ifdef HOSTS_ACCESS
if (!hosts_access(&request))
refuse(&request);
#endif
/* Report request and invoke the real daemon program. */
syslog(allow_severity, "connect from %s", eval_client(&request));
closelog();
(void) execv(path, argv);
syslog(LOG_ERR, "error: cannot execute %s: %m", path);
clean_exit(&request);
/* NOTREACHED */
}

219
contrib/tcp_wrappers/tcpd.h Normal file
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/*
* @(#) tcpd.h 1.5 96/03/19 16:22:24
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
/* Structure to describe one communications endpoint. */
#define STRING_LENGTH 128 /* hosts, users, processes */
struct host_info {
char name[STRING_LENGTH]; /* access via eval_hostname(host) */
char addr[STRING_LENGTH]; /* access via eval_hostaddr(host) */
struct sockaddr_in *sin; /* socket address or 0 */
struct t_unitdata *unit; /* TLI transport address or 0 */
struct request_info *request; /* for shared information */
};
/* Structure to describe what we know about a service request. */
struct request_info {
int fd; /* socket handle */
char user[STRING_LENGTH]; /* access via eval_user(request) */
char daemon[STRING_LENGTH]; /* access via eval_daemon(request) */
char pid[10]; /* access via eval_pid(request) */
struct host_info client[1]; /* client endpoint info */
struct host_info server[1]; /* server endpoint info */
void (*sink) (); /* datagram sink function or 0 */
void (*hostname) (); /* address to printable hostname */
void (*hostaddr) (); /* address to printable address */
void (*cleanup) (); /* cleanup function or 0 */
struct netconfig *config; /* netdir handle */
};
/* Common string operations. Less clutter should be more readable. */
#define STRN_CPY(d,s,l) { strncpy((d),(s),(l)); (d)[(l)-1] = 0; }
#define STRN_EQ(x,y,l) (strncasecmp((x),(y),(l)) == 0)
#define STRN_NE(x,y,l) (strncasecmp((x),(y),(l)) != 0)
#define STR_EQ(x,y) (strcasecmp((x),(y)) == 0)
#define STR_NE(x,y) (strcasecmp((x),(y)) != 0)
/*
* Initially, all above strings have the empty value. Information that
* cannot be determined at runtime is set to "unknown", so that we can
* distinguish between `unavailable' and `not yet looked up'. A hostname
* that we do not believe in is set to "paranoid".
*/
#define STRING_UNKNOWN "unknown" /* lookup failed */
#define STRING_PARANOID "paranoid" /* hostname conflict */
extern char unknown[];
extern char paranoid[];
#define HOSTNAME_KNOWN(s) (STR_NE((s),unknown) && STR_NE((s),paranoid))
#define NOT_INADDR(s) (s[strspn(s,"01234567890./")] != 0)
/* Global functions. */
#if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
extern void fromhost(); /* get/validate client host info */
#else
#define fromhost sock_host /* no TLI support needed */
#endif
extern int hosts_access(); /* access control */
extern void shell_cmd(); /* execute shell command */
extern char *percent_x(); /* do %<char> expansion */
extern void rfc931(); /* client name from RFC 931 daemon */
extern void clean_exit(); /* clean up and exit */
extern void refuse(); /* clean up and exit */
extern char *xgets(); /* fgets() on steroids */
extern char *split_at(); /* strchr() and split */
extern unsigned long dot_quad_addr(); /* restricted inet_addr() */
/* Global variables. */
extern int allow_severity; /* for connection logging */
extern int deny_severity; /* for connection logging */
extern char *hosts_allow_table; /* for verification mode redirection */
extern char *hosts_deny_table; /* for verification mode redirection */
extern int hosts_access_verbose; /* for verbose matching mode */
extern int rfc931_timeout; /* user lookup timeout */
extern int resident; /* > 0 if resident process */
/*
* Routines for controlled initialization and update of request structure
* attributes. Each attribute has its own key.
*/
#ifdef __STDC__
extern struct request_info *request_init(struct request_info *,...);
extern struct request_info *request_set(struct request_info *,...);
#else
extern struct request_info *request_init(); /* initialize request */
extern struct request_info *request_set(); /* update request structure */
#endif
#define RQ_FILE 1 /* file descriptor */
#define RQ_DAEMON 2 /* server process (argv[0]) */
#define RQ_USER 3 /* client user name */
#define RQ_CLIENT_NAME 4 /* client host name */
#define RQ_CLIENT_ADDR 5 /* client host address */
#define RQ_CLIENT_SIN 6 /* client endpoint (internal) */
#define RQ_SERVER_NAME 7 /* server host name */
#define RQ_SERVER_ADDR 8 /* server host address */
#define RQ_SERVER_SIN 9 /* server endpoint (internal) */
/*
* Routines for delayed evaluation of request attributes. Each attribute
* type has its own access method. The trivial ones are implemented by
* macros. The other ones are wrappers around the transport-specific host
* name, address, and client user lookup methods. The request_info and
* host_info structures serve as caches for the lookup results.
*/
extern char *eval_user(); /* client user */
extern char *eval_hostname(); /* printable hostname */
extern char *eval_hostaddr(); /* printable host address */
extern char *eval_hostinfo(); /* host name or address */
extern char *eval_client(); /* whatever is available */
extern char *eval_server(); /* whatever is available */
#define eval_daemon(r) ((r)->daemon) /* daemon process name */
#define eval_pid(r) ((r)->pid) /* process id */
/* Socket-specific methods, including DNS hostname lookups. */
extern void sock_host(); /* look up endpoint addresses */
extern void sock_hostname(); /* translate address to hostname */
extern void sock_hostaddr(); /* address to printable address */
#define sock_methods(r) \
{ (r)->hostname = sock_hostname; (r)->hostaddr = sock_hostaddr; }
/* The System V Transport-Level Interface (TLI) interface. */
#if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
extern void tli_host(); /* look up endpoint addresses etc. */
#endif
/*
* Problem reporting interface. Additional file/line context is reported
* when available. The jump buffer (tcpd_buf) is not declared here, or
* everyone would have to include <setjmp.h>.
*/
#ifdef __STDC__
extern void tcpd_warn(char *, ...); /* report problem and proceed */
extern void tcpd_jump(char *, ...); /* report problem and jump */
#else
extern void tcpd_warn();
extern void tcpd_jump();
#endif
struct tcpd_context {
char *file; /* current file */
int line; /* current line */
};
extern struct tcpd_context tcpd_context;
/*
* While processing access control rules, error conditions are handled by
* jumping back into the hosts_access() routine. This is cleaner than
* checking the return value of each and every silly little function. The
* (-1) returns are here because zero is already taken by longjmp().
*/
#define AC_PERMIT 1 /* permit access */
#define AC_DENY (-1) /* deny_access */
#define AC_ERROR AC_DENY /* XXX */
/*
* In verification mode an option function should just say what it would do,
* instead of really doing it. An option function that would not return
* should clear the dry_run flag to inform the caller of this unusual
* behavior.
*/
extern void process_options(); /* execute options */
extern int dry_run; /* verification flag */
/* Bug workarounds. */
#ifdef INET_ADDR_BUG /* inet_addr() returns struct */
#define inet_addr fix_inet_addr
extern long fix_inet_addr();
#endif
#ifdef BROKEN_FGETS /* partial reads from sockets */
#define fgets fix_fgets
extern char *fix_fgets();
#endif
#ifdef RECVFROM_BUG /* no address family info */
#define recvfrom fix_recvfrom
extern int fix_recvfrom();
#endif
#ifdef GETPEERNAME_BUG /* claims success with UDP */
#define getpeername fix_getpeername
extern int fix_getpeername();
#endif
#ifdef SOLARIS_24_GETHOSTBYNAME_BUG /* lists addresses as aliases */
#define gethostbyname fix_gethostbyname
extern struct hostent *fix_gethostbyname();
#endif
#ifdef USE_STRSEP /* libc calls strtok() */
#define strtok fix_strtok
extern char *fix_strtok();
#endif
#ifdef LIBC_CALLS_STRTOK /* libc calls strtok() */
#define strtok my_strtok
extern char *my_strtok();
#endif

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.TH TCPDCHK 8
.SH NAME
tcpdchk \- tcp wrapper configuration checker
.SH SYNOPSYS
tcpdchk [-a] [-d] [-i inet_conf] [-v]
.SH DESCRIPTION
.PP
\fItcpdchk\fR examines your tcp wrapper configuration and reports all
potential and real problems it can find. The program examines the
\fItcpd\fR access control files (by default, these are
\fI/etc/hosts.allow\fR and \fI/etc/hosts.deny\fR), and compares the
entries in these files against entries in the \fIinetd\fR or \fItlid\fR
network configuration files.
.PP
\fItcpdchk\fR reports problems such as non-existent pathnames; services
that appear in \fItcpd\fR access control rules, but are not controlled
by \fItcpd\fR; services that should not be wrapped; non-existent host
names or non-internet address forms; occurrences of host aliases
instead of official host names; hosts with a name/address conflict;
inappropriate use of wildcard patterns; inappropriate use of NIS
netgroups or references to non-existent NIS netgroups; references to
non-existent options; invalid arguments to options; and so on.
.PP
Where possible, \fItcpdchk\fR provides a helpful suggestion to fix the
problem.
.SH OPTIONS
.IP -a
Report access control rules that permit access without an explicit
ALLOW keyword. This applies only when the extended access control
language is enabled (build with -DPROCESS_OPTIONS).
.IP -d
Examine \fIhosts.allow\fR and \fIhosts.deny\fR files in the current
directory instead of the default ones.
.IP "-i inet_conf"
Specify this option when \fItcpdchk\fR is unable to find your
\fIinetd.conf\fR or \fItlid.conf\fR network configuration file, or when
you suspect that the program uses the wrong one.
.IP -v
Display the contents of each access control rule. Daemon lists, client
lists, shell commands and options are shown in a pretty-printed format;
this makes it easier for you to spot any discrepancies between what you
want and what the program understands.
.SH FILES
.PP
The default locations of the \fItcpd\fR access control tables are:
.PP
/etc/hosts.allow
.br
/etc/hosts.deny
.SH SEE ALSO
.na
.nf
tcpdmatch(8), explain what tcpd would do in specific cases.
hosts_access(5), format of the tcpd access control tables.
hosts_options(5), format of the language extensions.
inetd.conf(5), format of the inetd control file.
tlid.conf(5), format of the tlid control file.
.SH AUTHORS
.na
.nf
Wietse Venema (wietse@wzv.win.tue.nl),
Department of Mathematics and Computing Science,
Eindhoven University of Technology
Den Dolech 2, P.O. Box 513,
5600 MB Eindhoven, The Netherlands
\" @(#) tcpdchk.8 1.3 95/01/08 17:00:30

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/*
* tcpdchk - examine all tcpd access control rules and inetd.conf entries
*
* Usage: tcpdchk [-a] [-d] [-i inet_conf] [-v]
*
* -a: complain about implicit "allow" at end of rule.
*
* -d: rules in current directory.
*
* -i: location of inetd.conf file.
*
* -v: show all rules.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) tcpdchk.c 1.8 97/02/12 02:13:25";
#endif
/* System libraries. */
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <syslog.h>
#include <setjmp.h>
#include <errno.h>
#include <netdb.h>
#include <string.h>
extern int errno;
extern void exit();
extern int optind;
extern char *optarg;
#ifndef INADDR_NONE
#define INADDR_NONE (-1) /* XXX should be 0xffffffff */
#endif
#ifndef S_ISDIR
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif
/* Application-specific. */
#include "tcpd.h"
#include "inetcf.h"
#include "scaffold.h"
/*
* Stolen from hosts_access.c...
*/
static char sep[] = ", \t\n";
#define BUFLEN 2048
int resident = 0;
int hosts_access_verbose = 0;
char *hosts_allow_table = HOSTS_ALLOW;
char *hosts_deny_table = HOSTS_DENY;
extern jmp_buf tcpd_buf;
/*
* Local stuff.
*/
static void usage();
static void parse_table();
static void print_list();
static void check_daemon_list();
static void check_client_list();
static void check_daemon();
static void check_user();
static int check_host();
static int reserved_name();
#define PERMIT 1
#define DENY 0
#define YES 1
#define NO 0
static int defl_verdict;
static char *myname;
static int allow_check;
static char *inetcf;
int main(argc, argv)
int argc;
char **argv;
{
struct request_info request;
struct stat st;
int c;
myname = argv[0];
/*
* Parse the JCL.
*/
while ((c = getopt(argc, argv, "adi:v")) != EOF) {
switch (c) {
case 'a':
allow_check = 1;
break;
case 'd':
hosts_allow_table = "hosts.allow";
hosts_deny_table = "hosts.deny";
break;
case 'i':
inetcf = optarg;
break;
case 'v':
hosts_access_verbose++;
break;
default:
usage();
/* NOTREACHED */
}
}
if (argc != optind)
usage();
/*
* When confusion really strikes...
*/
if (check_path(REAL_DAEMON_DIR, &st) < 0) {
tcpd_warn("REAL_DAEMON_DIR %s: %m", REAL_DAEMON_DIR);
} else if (!S_ISDIR(st.st_mode)) {
tcpd_warn("REAL_DAEMON_DIR %s is not a directory", REAL_DAEMON_DIR);
}
/*
* Process the inet configuration file (or its moral equivalent). This
* information is used later to find references in hosts.allow/deny to
* unwrapped services, and other possible problems.
*/
inetcf = inet_cfg(inetcf);
if (hosts_access_verbose)
printf("Using network configuration file: %s\n", inetcf);
/*
* These are not run from inetd but may have built-in access control.
*/
inet_set("portmap", WR_NOT);
inet_set("rpcbind", WR_NOT);
/*
* Check accessibility of access control files.
*/
(void) check_path(hosts_allow_table, &st);
(void) check_path(hosts_deny_table, &st);
/*
* Fake up an arbitrary service request.
*/
request_init(&request,
RQ_DAEMON, "daemon_name",
RQ_SERVER_NAME, "server_hostname",
RQ_SERVER_ADDR, "server_addr",
RQ_USER, "user_name",
RQ_CLIENT_NAME, "client_hostname",
RQ_CLIENT_ADDR, "client_addr",
RQ_FILE, 1,
0);
/*
* Examine all access-control rules.
*/
defl_verdict = PERMIT;
parse_table(hosts_allow_table, &request);
defl_verdict = DENY;
parse_table(hosts_deny_table, &request);
return (0);
}
/* usage - explain */
static void usage()
{
fprintf(stderr, "usage: %s [-a] [-d] [-i inet_conf] [-v]\n", myname);
fprintf(stderr, " -a: report rules with implicit \"ALLOW\" at end\n");
fprintf(stderr, " -d: use allow/deny files in current directory\n");
fprintf(stderr, " -i: location of inetd.conf file\n");
fprintf(stderr, " -v: list all rules\n");
exit(1);
}
/* parse_table - like table_match(), but examines _all_ entries */
static void parse_table(table, request)
char *table;
struct request_info *request;
{
FILE *fp;
int real_verdict;
char sv_list[BUFLEN]; /* becomes list of daemons */
char *cl_list; /* becomes list of requests */
char *sh_cmd; /* becomes optional shell command */
char buf[BUFSIZ];
int verdict;
struct tcpd_context saved_context;
saved_context = tcpd_context; /* stupid compilers */
if (fp = fopen(table, "r")) {
tcpd_context.file = table;
tcpd_context.line = 0;
while (xgets(sv_list, sizeof(sv_list), fp)) {
if (sv_list[strlen(sv_list) - 1] != '\n') {
tcpd_warn("missing newline or line too long");
continue;
}
if (sv_list[0] == '#' || sv_list[strspn(sv_list, " \t\r\n")] == 0)
continue;
if ((cl_list = split_at(sv_list, ':')) == 0) {
tcpd_warn("missing \":\" separator");
continue;
}
sh_cmd = split_at(cl_list, ':');
if (hosts_access_verbose)
printf("\n>>> Rule %s line %d:\n",
tcpd_context.file, tcpd_context.line);
if (hosts_access_verbose)
print_list("daemons: ", sv_list);
check_daemon_list(sv_list);
if (hosts_access_verbose)
print_list("clients: ", cl_list);
check_client_list(cl_list);
#ifdef PROCESS_OPTIONS
real_verdict = defl_verdict;
if (sh_cmd) {
verdict = setjmp(tcpd_buf);
if (verdict != 0) {
real_verdict = (verdict == AC_PERMIT);
} else {
dry_run = 1;
process_options(sh_cmd, request);
if (dry_run == 1 && real_verdict && allow_check)
tcpd_warn("implicit \"allow\" at end of rule");
}
} else if (defl_verdict && allow_check) {
tcpd_warn("implicit \"allow\" at end of rule");
}
if (hosts_access_verbose)
printf("access: %s\n", real_verdict ? "granted" : "denied");
#else
if (sh_cmd)
shell_cmd(percent_x(buf, sizeof(buf), sh_cmd, request));
if (hosts_access_verbose)
printf("access: %s\n", defl_verdict ? "granted" : "denied");
#endif
}
(void) fclose(fp);
} else if (errno != ENOENT) {
tcpd_warn("cannot open %s: %m", table);
}
tcpd_context = saved_context;
}
/* print_list - pretty-print a list */
static void print_list(title, list)
char *title;
char *list;
{
char buf[BUFLEN];
char *cp;
char *next;
fputs(title, stdout);
strcpy(buf, list);
for (cp = strtok(buf, sep); cp != 0; cp = next) {
fputs(cp, stdout);
next = strtok((char *) 0, sep);
if (next != 0)
fputs(" ", stdout);
}
fputs("\n", stdout);
}
/* check_daemon_list - criticize daemon list */
static void check_daemon_list(list)
char *list;
{
char buf[BUFLEN];
char *cp;
char *host;
int daemons = 0;
strcpy(buf, list);
for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) {
if (STR_EQ(cp, "EXCEPT")) {
daemons = 0;
} else {
daemons++;
if ((host = split_at(cp + 1, '@')) != 0 && check_host(host) > 1) {
tcpd_warn("host %s has more than one address", host);
tcpd_warn("(consider using an address instead)");
}
check_daemon(cp);
}
}
if (daemons == 0)
tcpd_warn("daemon list is empty or ends in EXCEPT");
}
/* check_client_list - criticize client list */
static void check_client_list(list)
char *list;
{
char buf[BUFLEN];
char *cp;
char *host;
int clients = 0;
strcpy(buf, list);
for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) {
if (STR_EQ(cp, "EXCEPT")) {
clients = 0;
} else {
clients++;
if (host = split_at(cp + 1, '@')) { /* user@host */
check_user(cp);
check_host(host);
} else {
check_host(cp);
}
}
}
if (clients == 0)
tcpd_warn("client list is empty or ends in EXCEPT");
}
/* check_daemon - criticize daemon pattern */
static void check_daemon(pat)
char *pat;
{
if (pat[0] == '@') {
tcpd_warn("%s: daemon name begins with \"@\"", pat);
} else if (pat[0] == '.') {
tcpd_warn("%s: daemon name begins with dot", pat);
} else if (pat[strlen(pat) - 1] == '.') {
tcpd_warn("%s: daemon name ends in dot", pat);
} else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)) {
/* void */ ;
} else if (STR_EQ(pat, "FAIL")) { /* obsolete */
tcpd_warn("FAIL is no longer recognized");
tcpd_warn("(use EXCEPT or DENY instead)");
} else if (reserved_name(pat)) {
tcpd_warn("%s: daemon name may be reserved word", pat);
} else {
switch (inet_get(pat)) {
case WR_UNKNOWN:
tcpd_warn("%s: no such process name in %s", pat, inetcf);
inet_set(pat, WR_YES); /* shut up next time */
break;
case WR_NOT:
tcpd_warn("%s: service possibly not wrapped", pat);
inet_set(pat, WR_YES);
break;
}
}
}
/* check_user - criticize user pattern */
static void check_user(pat)
char *pat;
{
if (pat[0] == '@') { /* @netgroup */
tcpd_warn("%s: user name begins with \"@\"", pat);
} else if (pat[0] == '.') {
tcpd_warn("%s: user name begins with dot", pat);
} else if (pat[strlen(pat) - 1] == '.') {
tcpd_warn("%s: user name ends in dot", pat);
} else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)
|| STR_EQ(pat, "KNOWN")) {
/* void */ ;
} else if (STR_EQ(pat, "FAIL")) { /* obsolete */
tcpd_warn("FAIL is no longer recognized");
tcpd_warn("(use EXCEPT or DENY instead)");
} else if (reserved_name(pat)) {
tcpd_warn("%s: user name may be reserved word", pat);
}
}
/* check_host - criticize host pattern */
static int check_host(pat)
char *pat;
{
char *mask;
int addr_count = 1;
if (pat[0] == '@') { /* @netgroup */
#ifdef NO_NETGRENT
/* SCO has no *netgrent() support */
#else
#ifdef NETGROUP
char *machinep;
char *userp;
char *domainp;
setnetgrent(pat + 1);
if (getnetgrent(&machinep, &userp, &domainp) == 0)
tcpd_warn("%s: unknown or empty netgroup", pat + 1);
endnetgrent();
#else
tcpd_warn("netgroup support disabled");
#endif
#endif
} else if (mask = split_at(pat, '/')) { /* network/netmask */
if (dot_quad_addr(pat) == INADDR_NONE
|| dot_quad_addr(mask) == INADDR_NONE)
tcpd_warn("%s/%s: bad net/mask pattern", pat, mask);
} else if (STR_EQ(pat, "FAIL")) { /* obsolete */
tcpd_warn("FAIL is no longer recognized");
tcpd_warn("(use EXCEPT or DENY instead)");
} else if (reserved_name(pat)) { /* other reserved */
/* void */ ;
} else if (NOT_INADDR(pat)) { /* internet name */
if (pat[strlen(pat) - 1] == '.') {
tcpd_warn("%s: domain or host name ends in dot", pat);
} else if (pat[0] != '.') {
addr_count = check_dns(pat);
}
} else { /* numeric form */
if (STR_EQ(pat, "0.0.0.0") || STR_EQ(pat, "255.255.255.255")) {
/* void */ ;
} else if (pat[0] == '.') {
tcpd_warn("%s: network number begins with dot", pat);
} else if (pat[strlen(pat) - 1] != '.') {
check_dns(pat);
}
}
return (addr_count);
}
/* reserved_name - determine if name is reserved */
static int reserved_name(pat)
char *pat;
{
return (STR_EQ(pat, unknown)
|| STR_EQ(pat, "KNOWN")
|| STR_EQ(pat, paranoid)
|| STR_EQ(pat, "ALL")
|| STR_EQ(pat, "LOCAL"));
}

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@ -0,0 +1,98 @@
.TH TCPDMATCH 8
.SH NAME
tcpdmatch \- tcp wrapper oracle
.SH SYNOPSYS
tcpdmatch [-d] [-i inet_conf] daemon client
.sp
tcpdmatch [-d] [-i inet_conf] daemon[@server] [user@]client
.SH DESCRIPTION
.PP
\fItcpdmatch\fR predicts how the tcp wrapper would handle a specific
request for service. Examples are given below.
.PP
The program examines the \fItcpd\fR access control tables (default
\fI/etc/hosts.allow\fR and \fI/etc/hosts.deny\fR) and prints its
conclusion. For maximal accuracy, it extracts additional information
from your \fIinetd\fR or \fItlid\fR network configuration file.
.PP
When \fItcpdmatch\fR finds a match in the access control tables, it
identifies the matched rule. In addition, it displays the optional
shell commands or options in a pretty-printed format; this makes it
easier for you to spot any discrepancies between what you want and what
the program understands.
.SH ARGUMENTS
The following two arguments are always required:
.IP daemon
A daemon process name. Typically, the last component of a daemon
executable pathname.
.IP client
A host name or network address, or one of the `unknown' or `paranoid'
wildcard patterns.
.sp
When a client host name is specified, \fItcpdmatch\fR gives a
prediction for each address listed for that client.
.sp
When a client address is specified, \fItcpdmatch\fR predicts what
\fItcpd\fR would do when client name lookup fails.
.PP
Optional information specified with the \fIdaemon@server\fR form:
.IP server
A host name or network address, or one of the `unknown' or `paranoid'
wildcard patterns. The default server name is `unknown'.
.PP
Optional information specified with the \fIuser@client\fR form:
.IP user
A client user identifier. Typically, a login name or a numeric userid.
The default user name is `unknown'.
.SH OPTIONS
.IP -d
Examine \fIhosts.allow\fR and \fIhosts.deny\fR files in the current
directory instead of the default ones.
.IP "-i inet_conf"
Specify this option when \fItcpdmatch\fR is unable to find your
\fIinetd.conf\fR or \fItlid.conf\fR network configuration file, or when
you suspect that the program uses the wrong one.
.SH EXAMPLES
To predict how \fItcpd\fR would handle a telnet request from the local
system:
.sp
.ti +5
tcpdmatch in.telnetd localhost
.PP
The same request, pretending that hostname lookup failed:
.sp
.ti +5
tcpdmatch in.telnetd 127.0.0.1
.PP
To predict what tcpd would do when the client name does not match the
client address:
.sp
.ti +5
tcpdmatch in.telnetd paranoid
.PP
On some systems, daemon names have no `in.' prefix, or \fItcpdmatch\fR
may need some help to locate the inetd configuration file.
.SH FILES
.PP
The default locations of the \fItcpd\fR access control tables are:
.PP
/etc/hosts.allow
.br
/etc/hosts.deny
.SH SEE ALSO
.na
.nf
tcpdchk(8), tcpd configuration checker
hosts_access(5), format of the tcpd access control tables.
hosts_options(5), format of the language extensions.
inetd.conf(5), format of the inetd control file.
tlid.conf(5), format of the tlid control file.
.SH AUTHORS
.na
.nf
Wietse Venema (wietse@wzv.win.tue.nl),
Department of Mathematics and Computing Science,
Eindhoven University of Technology
Den Dolech 2, P.O. Box 513,
5600 MB Eindhoven, The Netherlands
\" @(#) tcpdmatch.8 1.5 96/02/11 17:01:35

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@ -0,0 +1,328 @@
/*
* tcpdmatch - explain what tcpd would do in a specific case
*
* usage: tcpdmatch [-d] [-i inet_conf] daemon[@host] [user@]host
*
* -d: use the access control tables in the current directory.
*
* -i: location of inetd.conf file.
*
* All errors are reported to the standard error stream, including the errors
* that would normally be reported via the syslog daemon.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) tcpdmatch.c 1.5 96/02/11 17:01:36";
#endif
/* System libraries. */
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <syslog.h>
#include <setjmp.h>
#include <string.h>
extern void exit();
extern int optind;
extern char *optarg;
#ifndef INADDR_NONE
#define INADDR_NONE (-1) /* XXX should be 0xffffffff */
#endif
#ifndef S_ISDIR
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif
/* Application-specific. */
#include "tcpd.h"
#include "inetcf.h"
#include "scaffold.h"
static void usage();
static void tcpdmatch();
/* The main program */
int main(argc, argv)
int argc;
char **argv;
{
struct hostent *hp;
char *myname = argv[0];
char *client;
char *server;
char *addr;
char *user;
char *daemon;
struct request_info request;
int ch;
char *inetcf = 0;
int count;
struct sockaddr_in server_sin;
struct sockaddr_in client_sin;
struct stat st;
/*
* Show what rule actually matched.
*/
hosts_access_verbose = 2;
/*
* Parse the JCL.
*/
while ((ch = getopt(argc, argv, "di:")) != EOF) {
switch (ch) {
case 'd':
hosts_allow_table = "hosts.allow";
hosts_deny_table = "hosts.deny";
break;
case 'i':
inetcf = optarg;
break;
default:
usage(myname);
/* NOTREACHED */
}
}
if (argc != optind + 2)
usage(myname);
/*
* When confusion really strikes...
*/
if (check_path(REAL_DAEMON_DIR, &st) < 0) {
tcpd_warn("REAL_DAEMON_DIR %s: %m", REAL_DAEMON_DIR);
} else if (!S_ISDIR(st.st_mode)) {
tcpd_warn("REAL_DAEMON_DIR %s is not a directory", REAL_DAEMON_DIR);
}
/*
* Default is to specify a daemon process name. When daemon@host is
* specified, separate the two parts.
*/
if ((server = split_at(argv[optind], '@')) == 0)
server = unknown;
if (argv[optind][0] == '/') {
daemon = strrchr(argv[optind], '/') + 1;
tcpd_warn("%s: daemon name normalized to: %s", argv[optind], daemon);
} else {
daemon = argv[optind];
}
/*
* Default is to specify a client hostname or address. When user@host is
* specified, separate the two parts.
*/
if ((client = split_at(argv[optind + 1], '@')) != 0) {
user = argv[optind + 1];
} else {
client = argv[optind + 1];
user = unknown;
}
/*
* Analyze the inetd (or tlid) configuration file, so that we can warn
* the user about services that may not be wrapped, services that are not
* configured, or services that are wrapped in an incorrect manner. Allow
* for services that are not run from inetd, or that have tcpd access
* control built into them.
*/
inetcf = inet_cfg(inetcf);
inet_set("portmap", WR_NOT);
inet_set("rpcbind", WR_NOT);
switch (inet_get(daemon)) {
case WR_UNKNOWN:
tcpd_warn("%s: no such process name in %s", daemon, inetcf);
break;
case WR_NOT:
tcpd_warn("%s: service possibly not wrapped", daemon);
break;
}
/*
* Check accessibility of access control files.
*/
(void) check_path(hosts_allow_table, &st);
(void) check_path(hosts_deny_table, &st);
/*
* Fill in what we have figured out sofar. Use socket and DNS routines
* for address and name conversions. We attach stdout to the request so
* that banner messages will become visible.
*/
request_init(&request, RQ_DAEMON, daemon, RQ_USER, user, RQ_FILE, 1, 0);
sock_methods(&request);
/*
* If a server hostname is specified, insist that the name maps to at
* most one address. eval_hostname() warns the user about name server
* problems, while using the request.server structure as a cache for host
* address and name conversion results.
*/
if (NOT_INADDR(server) == 0 || HOSTNAME_KNOWN(server)) {
if ((hp = find_inet_addr(server)) == 0)
exit(1);
memset((char *) &server_sin, 0, sizeof(server_sin));
server_sin.sin_family = AF_INET;
request_set(&request, RQ_SERVER_SIN, &server_sin, 0);
for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
memcpy((char *) &server_sin.sin_addr, addr,
sizeof(server_sin.sin_addr));
/*
* Force evaluation of server host name and address. Host name
* conflicts will be reported while eval_hostname() does its job.
*/
request_set(&request, RQ_SERVER_NAME, "", RQ_SERVER_ADDR, "", 0);
if (STR_EQ(eval_hostname(request.server), unknown))
tcpd_warn("host address %s->name lookup failed",
eval_hostaddr(request.server));
}
if (count > 1) {
fprintf(stderr, "Error: %s has more than one address\n", server);
fprintf(stderr, "Please specify an address instead\n");
exit(1);
}
free((char *) hp);
} else {
request_set(&request, RQ_SERVER_NAME, server, 0);
}
/*
* If a client address is specified, we simulate the effect of client
* hostname lookup failure.
*/
if (dot_quad_addr(client) != INADDR_NONE) {
request_set(&request, RQ_CLIENT_ADDR, client, 0);
tcpdmatch(&request);
exit(0);
}
/*
* Perhaps they are testing special client hostname patterns that aren't
* really host names at all.
*/
if (NOT_INADDR(client) && HOSTNAME_KNOWN(client) == 0) {
request_set(&request, RQ_CLIENT_NAME, client, 0);
tcpdmatch(&request);
exit(0);
}
/*
* Otherwise, assume that a client hostname is specified, and insist that
* the address can be looked up. The reason for this requirement is that
* in real life the client address is available (at least with IP). Let
* eval_hostname() figure out if this host is properly registered, while
* using the request.client structure as a cache for host name and
* address conversion results.
*/
if ((hp = find_inet_addr(client)) == 0)
exit(1);
memset((char *) &client_sin, 0, sizeof(client_sin));
client_sin.sin_family = AF_INET;
request_set(&request, RQ_CLIENT_SIN, &client_sin, 0);
for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
memcpy((char *) &client_sin.sin_addr, addr,
sizeof(client_sin.sin_addr));
/*
* Force evaluation of client host name and address. Host name
* conflicts will be reported while eval_hostname() does its job.
*/
request_set(&request, RQ_CLIENT_NAME, "", RQ_CLIENT_ADDR, "", 0);
if (STR_EQ(eval_hostname(request.client), unknown))
tcpd_warn("host address %s->name lookup failed",
eval_hostaddr(request.client));
tcpdmatch(&request);
if (hp->h_addr_list[count + 1])
printf("\n");
}
free((char *) hp);
exit(0);
}
/* Explain how to use this program */
static void usage(myname)
char *myname;
{
fprintf(stderr, "usage: %s [-d] [-i inet_conf] daemon[@host] [user@]host\n",
myname);
fprintf(stderr, " -d: use allow/deny files in current directory\n");
fprintf(stderr, " -i: location of inetd.conf file\n");
exit(1);
}
/* Print interesting expansions */
static void expand(text, pattern, request)
char *text;
char *pattern;
struct request_info *request;
{
char buf[BUFSIZ];
if (STR_NE(percent_x(buf, sizeof(buf), pattern, request), unknown))
printf("%s %s\n", text, buf);
}
/* Try out a (server,client) pair */
static void tcpdmatch(request)
struct request_info *request;
{
int verdict;
/*
* Show what we really know. Suppress uninteresting noise.
*/
expand("client: hostname", "%n", request);
expand("client: address ", "%a", request);
expand("client: username", "%u", request);
expand("server: hostname", "%N", request);
expand("server: address ", "%A", request);
expand("server: process ", "%d", request);
/*
* Reset stuff that might be changed by options handlers. In dry-run
* mode, extension language routines that would not return should inform
* us of their plan, by clearing the dry_run flag. This is a bit clumsy
* but we must be able to verify hosts with more than one network
* address.
*/
rfc931_timeout = RFC931_TIMEOUT;
allow_severity = SEVERITY;
deny_severity = LOG_WARNING;
dry_run = 1;
/*
* When paranoid mode is enabled, access is rejected no matter what the
* access control rules say.
*/
#ifdef PARANOID
if (STR_EQ(eval_hostname(request->client), paranoid)) {
printf("access: denied (PARANOID mode)\n\n");
return;
}
#endif
/*
* Report the access control verdict.
*/
verdict = hosts_access(request);
printf("access: %s\n",
dry_run == 0 ? "delegated" :
verdict ? "granted" : "denied");
}

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@ -0,0 +1,193 @@
/*
* Warning - this relies heavily on the TLI implementation in PTX 2.X and will
* probably not work under PTX 4.
*
* Author: Tim Wright, Sequent Computer Systems Ltd., UK.
*
* Modified slightly to conform to the new internal interfaces - Wietse
*/
#ifndef lint
static char sccsid[] = "@(#) tli-sequent.c 1.1 94/12/28 17:42:51";
#endif
#ifdef TLI_SEQUENT
/* System libraries. */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/tiuser.h>
#include <sys/stream.h>
#include <sys/stropts.h>
#include <sys/tihdr.h>
#include <sys/timod.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <syslog.h>
#include <errno.h>
#include <string.h>
extern int errno;
extern char *sys_errlist[];
extern int sys_nerr;
extern int t_errno;
extern char *t_errlist[];
extern int t_nerr;
/* Local stuff. */
#include "tcpd.h"
#include "tli-sequent.h"
/* Forward declarations. */
static char *tli_error();
static void tli_sink();
/* tli_host - determine endpoint info */
int tli_host(request)
struct request_info *request;
{
static struct sockaddr_in client;
static struct sockaddr_in server;
struct _ti_user *tli_state_ptr;
union T_primitives *TSI_prim_ptr;
struct strpeek peek;
int len;
/*
* Use DNS and socket routines for name and address conversions.
*/
sock_methods(request);
/*
* Find out the client address using getpeerinaddr(). This call is the
* TLI equivalent to getpeername() under Dynix/ptx.
*/
len = sizeof(client);
t_sync(request->fd);
if (getpeerinaddr(request->fd, &client, len) < 0) {
tcpd_warn("can't get client address: %s", tli_error());
return;
}
request->client->sin = &client;
/* Call TLI utility routine to get information on endpoint */
if ((tli_state_ptr = _t_checkfd(request->fd)) == NULL)
return;
if (tli_state_ptr->ti_servtype == T_CLTS) {
/* UDP - may need to get address the hard way */
if (client.sin_addr.s_addr == 0) {
/* The UDP endpoint is not connected so we didn't get the */
/* remote address - get it the hard way ! */
/* Look at the control part of the top message on the stream */
/* we don't want to remove it from the stream so we use I_PEEK */
peek.ctlbuf.maxlen = tli_state_ptr->ti_ctlsize;
peek.ctlbuf.len = 0;
peek.ctlbuf.buf = tli_state_ptr->ti_ctlbuf;
/* Don't even look at the data */
peek.databuf.maxlen = -1;
peek.databuf.len = 0;
peek.databuf.buf = 0;
peek.flags = 0;
switch (ioctl(request->fd, I_PEEK, &peek)) {
case -1:
tcpd_warn("can't peek at endpoint: %s", tli_error());
return;
case 0:
/* No control part - we're hosed */
tcpd_warn("can't get UDP info: %s", tli_error());
return;
default:
/* FALL THROUGH */
;
}
/* Can we even check the PRIM_type ? */
if (peek.ctlbuf.len < sizeof(long)) {
tcpd_warn("UDP control info garbage");
return;
}
TSI_prim_ptr = (union T_primitives *) peek.ctlbuf.buf;
if (TSI_prim_ptr->type != T_UNITDATA_IND) {
tcpd_warn("wrong type for UDP control info");
return;
}
/* Validate returned unitdata indication packet */
if ((peek.ctlbuf.len < sizeof(struct T_unitdata_ind)) ||
((TSI_prim_ptr->unitdata_ind.OPT_length != 0) &&
(peek.ctlbuf.len <
TSI_prim_ptr->unitdata_ind.OPT_length +
TSI_prim_ptr->unitdata_ind.OPT_offset))) {
tcpd_warn("UDP control info garbaged");
return;
}
/* Extract the address */
memcpy(&client,
peek.ctlbuf.buf + TSI_prim_ptr->unitdata_ind.SRC_offset,
TSI_prim_ptr->unitdata_ind.SRC_length);
}
request->sink = tli_sink;
}
if (getmyinaddr(request->fd, &server, len) < 0)
tcpd_warn("can't get local address: %s", tli_error());
else
request->server->sin = &server;
}
/* tli_error - convert tli error number to text */
static char *tli_error()
{
static char buf[40];
if (t_errno != TSYSERR) {
if (t_errno < 0 || t_errno >= t_nerr) {
sprintf(buf, "Unknown TLI error %d", t_errno);
return (buf);
} else {
return (t_errlist[t_errno]);
}
} else {
if (errno < 0 || errno >= sys_nerr) {
sprintf(buf, "Unknown UNIX error %d", errno);
return (buf);
} else {
return (sys_errlist[errno]);
}
}
}
/* tli_sink - absorb unreceived datagram */
static void tli_sink(fd)
int fd;
{
struct t_unitdata *unit;
int flags;
/*
* Something went wrong. Absorb the datagram to keep inetd from looping.
* Allocate storage for address, control and data. If that fails, sleep
* for a couple of seconds in an attempt to keep inetd from looping too
* fast.
*/
if ((unit = (struct t_unitdata *) t_alloc(fd, T_UNITDATA, T_ALL)) == 0) {
tcpd_warn("t_alloc: %s", tli_error());
sleep(5);
} else {
(void) t_rcvudata(fd, unit, &flags);
t_free((void *) unit, T_UNITDATA);
}
}
#endif /* TLI_SEQUENT */

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@ -0,0 +1,13 @@
#ifdef __STDC__
#define __P(X) X
#else
#define __P(X) ()
#endif
extern int t_sync __P((int));
extern char *t_alloc __P((int, int, int));
extern int t_free __P((char *, int));
extern int t_rcvudata __P((int, struct t_unitdata *, int *));
extern int getpeerinaddr __P((int, struct sockaddr_in *, int));
extern int getmyinaddr __P((int, struct sockaddr_in *, int));
extern struct _ti_user *_t_checkfd __P((int));

341
contrib/tcp_wrappers/tli.c Normal file
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/*
* tli_host() determines the type of transport (connected, connectionless),
* the transport address of a client host, and the transport address of a
* server endpoint. In addition, it provides methods to map a transport
* address to a printable host name or address. Socket address results are
* in static memory; tli structures are allocated from the heap.
*
* The result from the hostname lookup method is STRING_PARANOID when a host
* pretends to have someone elses name, or when a host name is available but
* could not be verified.
*
* Diagnostics are reported through syslog(3).
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) tli.c 1.15 97/03/21 19:27:25";
#endif
#ifdef TLI
/* System libraries. */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stream.h>
#include <sys/stat.h>
#include <sys/mkdev.h>
#include <sys/tiuser.h>
#include <sys/timod.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <syslog.h>
#include <errno.h>
#include <netconfig.h>
#include <netdir.h>
#include <string.h>
extern char *nc_sperror();
extern int errno;
extern char *sys_errlist[];
extern int sys_nerr;
extern int t_errno;
extern char *t_errlist[];
extern int t_nerr;
/* Local stuff. */
#include "tcpd.h"
/* Forward declarations. */
static void tli_endpoints();
static struct netconfig *tli_transport();
static void tli_hostname();
static void tli_hostaddr();
static void tli_cleanup();
static char *tli_error();
static void tli_sink();
/* tli_host - look up endpoint addresses and install conversion methods */
void tli_host(request)
struct request_info *request;
{
static struct sockaddr_in client;
static struct sockaddr_in server;
/*
* If we discover that we are using an IP transport, pretend we never
* were here. Otherwise, use the transport-independent method and stick
* to generic network addresses. XXX hard-coded protocol family name.
*/
tli_endpoints(request);
if ((request->config = tli_transport(request->fd)) != 0
&& STR_EQ(request->config->nc_protofmly, "inet")) {
if (request->client->unit != 0) {
client = *(struct sockaddr_in *) request->client->unit->addr.buf;
request->client->sin = &client;
}
if (request->server->unit != 0) {
server = *(struct sockaddr_in *) request->server->unit->addr.buf;
request->server->sin = &server;
}
tli_cleanup(request);
sock_methods(request);
} else {
request->hostname = tli_hostname;
request->hostaddr = tli_hostaddr;
request->cleanup = tli_cleanup;
}
}
/* tli_cleanup - cleanup some dynamically-allocated data structures */
static void tli_cleanup(request)
struct request_info *request;
{
if (request->config != 0)
freenetconfigent(request->config);
if (request->client->unit != 0)
t_free((char *) request->client->unit, T_UNITDATA);
if (request->server->unit != 0)
t_free((char *) request->server->unit, T_UNITDATA);
}
/* tli_endpoints - determine TLI client and server endpoint information */
static void tli_endpoints(request)
struct request_info *request;
{
struct t_unitdata *server;
struct t_unitdata *client;
int fd = request->fd;
int flags;
/*
* Determine the client endpoint address. With unconnected services, peek
* at the sender address of the pending protocol data unit without
* popping it off the receive queue. This trick works because only the
* address member of the unitdata structure has been allocated.
*
* Beware of successful returns with zero-length netbufs (for example,
* Solaris 2.3 with ticlts transport). The netdir(3) routines can't
* handle that. Assume connection-less transport when TI_GETPEERNAME
* produces no usable result, even when t_rcvudata() is unable to figure
* out the peer address. Better to hang than to loop.
*/
if ((client = (struct t_unitdata *) t_alloc(fd, T_UNITDATA, T_ADDR)) == 0) {
tcpd_warn("t_alloc: %s", tli_error());
return;
}
if (ioctl(fd, TI_GETPEERNAME, &client->addr) < 0 || client->addr.len == 0) {
request->sink = tli_sink;
if (t_rcvudata(fd, client, &flags) < 0 || client->addr.len == 0) {
tcpd_warn("can't get client address: %s", tli_error());
t_free((void *) client, T_UNITDATA);
return;
}
}
request->client->unit = client;
/*
* Look up the server endpoint address. This can be used for filtering on
* server address or name, or to look up the client user.
*/
if ((server = (struct t_unitdata *) t_alloc(fd, T_UNITDATA, T_ADDR)) == 0) {
tcpd_warn("t_alloc: %s", tli_error());
return;
}
if (ioctl(fd, TI_GETMYNAME, &server->addr) < 0) {
tcpd_warn("TI_GETMYNAME: %m");
t_free((void *) server, T_UNITDATA);
return;
}
request->server->unit = server;
}
/* tli_transport - find out TLI transport type */
static struct netconfig *tli_transport(fd)
int fd;
{
struct stat from_client;
struct stat from_config;
void *handlep;
struct netconfig *config;
/*
* Assuming that the network device is a clone device, we must compare
* the major device number of stdin to the minor device number of the
* devices listed in the netconfig table.
*/
if (fstat(fd, &from_client) != 0) {
tcpd_warn("fstat(fd %d): %m", fd);
return (0);
}
if ((handlep = setnetconfig()) == 0) {
tcpd_warn("setnetconfig: %m");
return (0);
}
while (config = getnetconfig(handlep)) {
if (stat(config->nc_device, &from_config) == 0) {
if (minor(from_config.st_rdev) == major(from_client.st_rdev))
break;
}
}
if (config == 0) {
tcpd_warn("unable to identify transport protocol");
return (0);
}
/*
* Something else may clobber our getnetconfig() result, so we'd better
* acquire our private copy.
*/
if ((config = getnetconfigent(config->nc_netid)) == 0) {
tcpd_warn("getnetconfigent(%s): %s", config->nc_netid, nc_sperror());
return (0);
}
return (config);
}
/* tli_hostaddr - map TLI transport address to printable address */
static void tli_hostaddr(host)
struct host_info *host;
{
struct request_info *request = host->request;
struct netconfig *config = request->config;
struct t_unitdata *unit = host->unit;
char *uaddr;
if (config != 0 && unit != 0
&& (uaddr = taddr2uaddr(config, &unit->addr)) != 0) {
STRN_CPY(host->addr, uaddr, sizeof(host->addr));
free(uaddr);
}
}
/* tli_hostname - map TLI transport address to hostname */
static void tli_hostname(host)
struct host_info *host;
{
struct request_info *request = host->request;
struct netconfig *config = request->config;
struct t_unitdata *unit = host->unit;
struct nd_hostservlist *servlist;
if (config != 0 && unit != 0
&& netdir_getbyaddr(config, &servlist, &unit->addr) == ND_OK) {
struct nd_hostserv *service = servlist->h_hostservs;
struct nd_addrlist *addr_list;
int found = 0;
if (netdir_getbyname(config, service, &addr_list) != ND_OK) {
/*
* Unable to verify that the name matches the address. This may
* be a transient problem or a botched name server setup. We
* decide to play safe.
*/
tcpd_warn("can't verify hostname: netdir_getbyname(%.*s) failed",
STRING_LENGTH, service->h_host);
} else {
/*
* Look up the host address in the address list we just got. The
* comparison is done on the textual representation, because the
* transport address is an opaque structure that may have holes
* with uninitialized garbage. This approach obviously loses when
* the address does not have a textual representation.
*/
char *uaddr = eval_hostaddr(host);
char *ua;
int i;
for (i = 0; found == 0 && i < addr_list->n_cnt; i++) {
if ((ua = taddr2uaddr(config, &(addr_list->n_addrs[i]))) != 0) {
found = !strcmp(ua, uaddr);
free(ua);
}
}
netdir_free((void *) addr_list, ND_ADDRLIST);
/*
* When the host name does not map to the initial address, assume
* someone has compromised a name server. More likely someone
* botched it, but that could be dangerous, too.
*/
if (found == 0)
tcpd_warn("host name/address mismatch: %s != %.*s",
host->addr, STRING_LENGTH, service->h_host);
}
STRN_CPY(host->name, found ? service->h_host : paranoid,
sizeof(host->name));
netdir_free((void *) servlist, ND_HOSTSERVLIST);
}
}
/* tli_error - convert tli error number to text */
static char *tli_error()
{
static char buf[40];
if (t_errno != TSYSERR) {
if (t_errno < 0 || t_errno >= t_nerr) {
sprintf(buf, "Unknown TLI error %d", t_errno);
return (buf);
} else {
return (t_errlist[t_errno]);
}
} else {
if (errno < 0 || errno >= sys_nerr) {
sprintf(buf, "Unknown UNIX error %d", errno);
return (buf);
} else {
return (sys_errlist[errno]);
}
}
}
/* tli_sink - absorb unreceived datagram */
static void tli_sink(fd)
int fd;
{
struct t_unitdata *unit;
int flags;
/*
* Something went wrong. Absorb the datagram to keep inetd from looping.
* Allocate storage for address, control and data. If that fails, sleep
* for a couple of seconds in an attempt to keep inetd from looping too
* fast.
*/
if ((unit = (struct t_unitdata *) t_alloc(fd, T_UNITDATA, T_ALL)) == 0) {
tcpd_warn("t_alloc: %s", tli_error());
sleep(5);
} else {
(void) t_rcvudata(fd, unit, &flags);
t_free((void *) unit, T_UNITDATA);
}
}
#endif /* TLI */

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@ -0,0 +1,85 @@
/*
* This program can be called via a remote shell command to find out if the
* hostname and address are properly recognized, if username lookup works,
* and (SysV only) if the TLI on top of IP heuristics work.
*
* Example: "rsh host /some/where/try-from".
*
* Diagnostics are reported through syslog(3) and redirected to stderr.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) try-from.c 1.2 94/12/28 17:42:55";
#endif
/* System libraries. */
#include <sys/types.h>
#include <stdio.h>
#include <syslog.h>
#include <string.h>
#ifdef TLI
#include <sys/tiuser.h>
#include <stropts.h>
#endif
#ifndef STDIN_FILENO
#define STDIN_FILENO 0
#endif
/* Local stuff. */
#include "tcpd.h"
int allow_severity = SEVERITY; /* run-time adjustable */
int deny_severity = LOG_WARNING; /* ditto */
main(argc, argv)
int argc;
char **argv;
{
struct request_info request;
char buf[BUFSIZ];
char *cp;
/*
* Simplify the process name, just like tcpd would.
*/
if ((cp = strrchr(argv[0], '/')) != 0)
argv[0] = cp + 1;
/*
* Turn on the "IP-underneath-TLI" detection heuristics.
*/
#ifdef TLI
if (ioctl(0, I_FIND, "timod") == 0)
ioctl(0, I_PUSH, "timod");
#endif /* TLI */
/*
* Look up the endpoint information.
*/
request_init(&request, RQ_DAEMON, argv[0], RQ_FILE, STDIN_FILENO, 0);
(void) fromhost(&request);
/*
* Show some results. Name and address information is looked up when we
* ask for it.
*/
#define EXPAND(str) percent_x(buf, sizeof(buf), str, &request)
puts(EXPAND("client address (%%a): %a"));
puts(EXPAND("client hostname (%%n): %n"));
puts(EXPAND("client username (%%u): %u"));
puts(EXPAND("client info (%%c): %c"));
puts(EXPAND("server address (%%A): %A"));
puts(EXPAND("server hostname (%%N): %N"));
puts(EXPAND("server process (%%d): %d"));
puts(EXPAND("server info (%%s): %s"));
return (0);
}

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/*
* Routines for controlled update/initialization of request structures.
*
* request_init() initializes its argument. Pointers and string-valued members
* are initialized to zero, to indicate that no lookup has been attempted.
*
* request_set() adds information to an already initialized request structure.
*
* Both functions take a variable-length name-value list.
*
* Diagnostics are reported through syslog(3).
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) update.c 1.1 94/12/28 17:42:56";
#endif
/* System libraries */
#include <stdio.h>
#include <syslog.h>
#include <string.h>
/* Local stuff. */
#include "mystdarg.h"
#include "tcpd.h"
/* request_fill - request update engine */
static struct request_info *request_fill(request, ap)
struct request_info *request;
va_list ap;
{
int key;
char *ptr;
while ((key = va_arg(ap, int)) > 0) {
switch (key) {
default:
tcpd_warn("request_fill: invalid key: %d", key);
return (request);
case RQ_FILE:
request->fd = va_arg(ap, int);
continue;
case RQ_CLIENT_SIN:
request->client->sin = va_arg(ap, struct sockaddr_in *);
continue;
case RQ_SERVER_SIN:
request->server->sin = va_arg(ap, struct sockaddr_in *);
continue;
/*
* All other fields are strings with the same maximal length.
*/
case RQ_DAEMON:
ptr = request->daemon;
break;
case RQ_USER:
ptr = request->user;
break;
case RQ_CLIENT_NAME:
ptr = request->client->name;
break;
case RQ_CLIENT_ADDR:
ptr = request->client->addr;
break;
case RQ_SERVER_NAME:
ptr = request->server->name;
break;
case RQ_SERVER_ADDR:
ptr = request->server->addr;
break;
}
STRN_CPY(ptr, va_arg(ap, char *), STRING_LENGTH);
}
return (request);
}
/* request_init - initialize request structure */
struct request_info *VARARGS(request_init, struct request_info *, request)
{
static struct request_info default_info;
struct request_info *r;
va_list ap;
/*
* Initialize data members. We do not assign default function pointer
* members, to avoid pulling in the whole socket module when it is not
* really needed.
*/
VASTART(ap, struct request_info *, request);
*request = default_info;
request->fd = -1;
strcpy(request->daemon, unknown);
sprintf(request->pid, "%d", getpid());
request->client->request = request;
request->server->request = request;
r = request_fill(request, ap);
VAEND(ap);
return (r);
}
/* request_set - update request structure */
struct request_info *VARARGS(request_set, struct request_info *, request)
{
struct request_info *r;
va_list ap;
VASTART(ap, struct request_info *, request);
r = request_fill(request, ap);
VAEND(ap);
return (r);
}

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/*
* vfprintf() and vprintf() clones. They will produce unexpected results
* when excessive dynamic ("*") field widths are specified. To be used for
* testing purposes only.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) vfprintf.c 1.2 94/03/23 17:44:46";
#endif
#include <stdio.h>
#include <ctype.h>
#ifdef __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
/* vfprintf - print variable-length argument list to stream */
int vfprintf(fp, format, ap)
FILE *fp;
char *format;
va_list ap;
{
char fmt[BUFSIZ]; /* format specifier */
register char *fmtp;
register char *cp;
int count = 0;
/*
* Iterate over characters in the format string, picking up arguments
* when format specifiers are found.
*/
for (cp = format; *cp; cp++) {
if (*cp != '%') {
putc(*cp, fp); /* ordinary character */
count++;
} else {
/*
* Format specifiers are handled one at a time, since we can only
* deal with arguments one at a time. Try to determine the end of
* the format specifier. We do not attempt to fully parse format
* strings, since we are ging to let fprintf() do the hard work.
* In regular expression notation, we recognize:
*
* %-?0?([0-9]+|\*)?\.?([0-9]+|\*)?l?[a-z]
*
* which includes some combinations that do not make sense.
*/
fmtp = fmt;
*fmtp++ = *cp++;
if (*cp == '-') /* left-adjusted field? */
*fmtp++ = *cp++;
if (*cp == '0') /* zero-padded field? */
*fmtp++ = *cp++;
if (*cp == '*') { /* dynamic field witdh */
sprintf(fmtp, "%d", va_arg(ap, int));
fmtp += strlen(fmtp);
cp++;
} else {
while (isdigit(*cp)) /* hard-coded field width */
*fmtp++ = *cp++;
}
if (*cp == '.') /* width/precision separator */
*fmtp++ = *cp++;
if (*cp == '*') { /* dynamic precision */
sprintf(fmtp, "%d", va_arg(ap, int));
fmtp += strlen(fmtp);
cp++;
} else {
while (isdigit(*cp)) /* hard-coded precision */
*fmtp++ = *cp++;
}
if (*cp == 'l') /* long whatever */
*fmtp++ = *cp++;
if (*cp == 0) /* premature end, punt */
break;
*fmtp++ = *cp; /* type (checked below) */
*fmtp = 0;
/* Execute the format string - let fprintf() do the hard work. */
switch (fmtp[-1]) {
case 's': /* string-valued argument */
count += fprintf(fp, fmt, va_arg(ap, char *));
break;
case 'c': /* integral-valued argument */
case 'd':
case 'u':
case 'o':
case 'x':
if (fmtp[-2] == 'l')
count += fprintf(fp, fmt, va_arg(ap, long));
else
count += fprintf(fp, fmt, va_arg(ap, int));
break;
case 'e': /* float-valued argument */
case 'f':
case 'g':
count += fprintf(fp, fmt, va_arg(ap, double));
break;
default: /* anything else */
putc(fmtp[-1], fp);
count++;
break;
}
}
}
return (count);
}
/* vprintf - print variable-length argument list to stdout */
vprintf(format, ap)
char *format;
va_list ap;
{
return (vfprintf(stdout, format, ap));
}

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/*
* Workarounds for known system software bugs. This module provides wrappers
* around library functions and system calls that are known to have problems
* on some systems. Most of these workarounds won't do any harm on regular
* systems.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
char sccsid[] = "@(#) workarounds.c 1.6 96/03/19 16:22:25";
#endif
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <errno.h>
#include <stdio.h>
#include <syslog.h>
#include <string.h>
extern int errno;
#include "tcpd.h"
/*
* Some AIX versions advertise a too small MAXHOSTNAMELEN value (32).
* Result: long hostnames would be truncated, and connections would be
* dropped because of host name verification failures. Adrian van Bloois
* (A.vanBloois@info.nic.surfnet.nl) figured out what was the problem.
*/
#if (MAXHOSTNAMELEN < 64)
#undef MAXHOSTNAMELEN
#endif
/* In case not defined in <sys/param.h>. */
#ifndef MAXHOSTNAMELEN
#define MAXHOSTNAMELEN 256 /* storage for host name */
#endif
/*
* Some DG/UX inet_addr() versions return a struct/union instead of a long.
* You have this problem when the compiler complains about illegal lvalues
* or something like that. The following code fixes this mutant behaviour.
* It should not be enabled on "normal" systems.
*
* Bug reported by ben@piglet.cr.usgs.gov (Rev. Ben A. Mesander).
*/
#ifdef INET_ADDR_BUG
#undef inet_addr
long fix_inet_addr(string)
char *string;
{
return (inet_addr(string).s_addr);
}
#endif /* INET_ADDR_BUG */
/*
* With some System-V versions, the fgets() library function does not
* account for partial reads from e.g. sockets. The result is that fgets()
* gives up too soon, causing username lookups to fail. Problem first
* reported for IRIX 4.0.5, by Steve Kotsopoulos <steve@ecf.toronto.edu>.
* The following code works around the problem. It does no harm on "normal"
* systems.
*/
#ifdef BROKEN_FGETS
#undef fgets
char *fix_fgets(buf, len, fp)
char *buf;
int len;
FILE *fp;
{
char *cp = buf;
int c;
/*
* Copy until the buffer fills up, until EOF, or until a newline is
* found.
*/
while (len > 1 && (c = getc(fp)) != EOF) {
len--;
*cp++ = c;
if (c == '\n')
break;
}
/*
* Return 0 if nothing was read. This is correct even when a silly buffer
* length was specified.
*/
if (cp > buf) {
*cp = 0;
return (buf);
} else {
return (0);
}
}
#endif /* BROKEN_FGETS */
/*
* With early SunOS 5 versions, recvfrom() does not completely fill in the
* source address structure when doing a non-destructive read. The following
* code works around the problem. It does no harm on "normal" systems.
*/
#ifdef RECVFROM_BUG
#undef recvfrom
int fix_recvfrom(sock, buf, buflen, flags, from, fromlen)
int sock;
char *buf;
int buflen;
int flags;
struct sockaddr *from;
int *fromlen;
{
int ret;
/* Assume that both ends of a socket belong to the same address family. */
if ((ret = recvfrom(sock, buf, buflen, flags, from, fromlen)) >= 0) {
if (from->sa_family == 0) {
struct sockaddr my_addr;
int my_addr_len = sizeof(my_addr);
if (getsockname(0, &my_addr, &my_addr_len)) {
tcpd_warn("getsockname: %m");
} else {
from->sa_family = my_addr.sa_family;
}
}
}
return (ret);
}
#endif /* RECVFROM_BUG */
/*
* The Apollo SR10.3 and some SYSV4 getpeername(2) versions do not return an
* error in case of a datagram-oriented socket. Instead, they claim that all
* UDP requests come from address 0.0.0.0. The following code works around
* the problem. It does no harm on "normal" systems.
*/
#ifdef GETPEERNAME_BUG
#undef getpeername
int fix_getpeername(sock, sa, len)
int sock;
struct sockaddr *sa;
int *len;
{
int ret;
struct sockaddr_in *sin = (struct sockaddr_in *) sa;
if ((ret = getpeername(sock, sa, len)) >= 0
&& sa->sa_family == AF_INET
&& sin->sin_addr.s_addr == 0) {
errno = ENOTCONN;
return (-1);
} else {
return (ret);
}
}
#endif /* GETPEERNAME_BUG */
/*
* According to Karl Vogel (vogelke@c-17igp.wpafb.af.mil) some Pyramid
* versions have no yp_default_domain() function. We use getdomainname()
* instead.
*/
#ifdef USE_GETDOMAIN
int yp_get_default_domain(ptr)
char **ptr;
{
static char mydomain[MAXHOSTNAMELEN];
*ptr = mydomain;
return (getdomainname(mydomain, MAXHOSTNAMELEN));
}
#endif /* USE_GETDOMAIN */
#ifndef INADDR_NONE
#define INADDR_NONE 0xffffffff
#endif
/*
* Solaris 2.4 gethostbyname() has problems with multihomed hosts. When
* doing DNS through NIS, only one host address ends up in the address list.
* All other addresses end up in the hostname alias list, interspersed with
* copies of the official host name. This would wreak havoc with tcpd's
* hostname double checks. Below is a workaround that should do no harm when
* accidentally left in. A side effect of the workaround is that address
* list members are no longer properly aligned for structure access.
*/
#ifdef SOLARIS_24_GETHOSTBYNAME_BUG
#undef gethostbyname
struct hostent *fix_gethostbyname(name)
char *name;
{
struct hostent *hp;
struct in_addr addr;
char **o_addr_list;
char **o_aliases;
char **n_addr_list;
int broken_gethostbyname = 0;
if ((hp = gethostbyname(name)) && !hp->h_addr_list[1] && hp->h_aliases[1]) {
for (o_aliases = n_addr_list = hp->h_aliases; *o_aliases; o_aliases++) {
if ((addr.s_addr = inet_addr(*o_aliases)) != INADDR_NONE) {
memcpy(*n_addr_list++, (char *) &addr, hp->h_length);
broken_gethostbyname = 1;
}
}
if (broken_gethostbyname) {
o_addr_list = hp->h_addr_list;
memcpy(*n_addr_list++, *o_addr_list, hp->h_length);
*n_addr_list = 0;
hp->h_addr_list = hp->h_aliases;
hp->h_aliases = o_addr_list + 1;
}
}
return (hp);
}
#endif /* SOLARIS_24_GETHOSTBYNAME_BUG */
/*
* Horror! Some FreeBSD 2.0 libc routines call strtok(). Since tcpd depends
* heavily on strtok(), strange things may happen. Workaround: use our
* private strtok(). This has been fixed in the meantime.
*/
#ifdef USE_STRSEP
char *fix_strtok(buf, sep)
char *buf;
char *sep;
{
static char *state;
char *result;
if (buf)
state = buf;
while ((result = strsep(&state, sep)) && result[0] == 0)
/* void */ ;
return (result);
}
#endif /* USE_STRSEP */
/*
* IRIX 5.3 (and possibly earlier versions, too) library routines call the
* non-reentrant strtok() library routine, causing hosts to slip through
* allow/deny filters. Workaround: don't rely on the vendor and use our own
* strtok() function. FreeBSD 2.0 has a similar problem (fixed in 2.0.5).
*/
#ifdef LIBC_CALLS_STRTOK
char *my_strtok(buf, sep)
char *buf;
char *sep;
{
static char *state;
char *result;
if (buf)
state = buf;
/*
* Skip over separator characters and detect end of string.
*/
if (*(state += strspn(state, sep)) == 0)
return (0);
/*
* Skip over non-separator characters and terminate result.
*/
result = state;
if (*(state += strcspn(state, sep)) != 0)
*state++ = 0;
return (result);
}
#endif /* LIBC_CALLS_STRTOK */