907 lines
22 KiB
Groff
907 lines
22 KiB
Groff
.\" Copyright (c) 1985, 1991, 1993, 1994
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" from: @(#)inetd.8 8.3 (Berkeley) 4/13/94
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd February 7, 1996
|
|
.Dt INETD 8
|
|
.Os
|
|
.Sh NAME
|
|
.Nm inetd
|
|
.Nd internet
|
|
.Dq super-server
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl d
|
|
.Op Fl l
|
|
.Op Fl w
|
|
.Op Fl W
|
|
.Op Fl c Ar maximum
|
|
.Op Fl C Ar rate
|
|
.Op Fl a Ar address | hostname
|
|
.Op Fl p Ar filename
|
|
.Op Fl R Ar rate
|
|
.Op Ar configuration file
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
program
|
|
should be run at boot time by
|
|
.Pa /etc/rc
|
|
(see
|
|
.Xr rc 8 ) .
|
|
It then listens for connections on certain
|
|
internet sockets. When a connection is found on one
|
|
of its sockets, it decides what service the socket
|
|
corresponds to, and invokes a program to service the request.
|
|
The server program is invoked with the service socket
|
|
as its standard input, output and error descriptors.
|
|
After the program is
|
|
finished,
|
|
.Nm
|
|
continues to listen on the socket (except in some cases which
|
|
will be described below). Essentially,
|
|
.Nm
|
|
allows running one daemon to invoke several others,
|
|
reducing load on the system.
|
|
.Pp
|
|
The following options are available:
|
|
.Bl -tag -width indent
|
|
.It Fl d
|
|
Turn on debugging.
|
|
.It Fl l
|
|
Turn on logging of successful connections.
|
|
.It Fl w
|
|
Turn on TCP Wrapping for external services.
|
|
See the
|
|
.Sx "IMPLEMENTATION NOTES"
|
|
section for more information on TCP Wrappers support.
|
|
.It Fl W
|
|
Turn on TCP Wrapping for internal services which are built in to
|
|
.Nm .
|
|
.It Fl c Ar maximum
|
|
Specify the default maximum number of
|
|
simultaneous invocations of each service;
|
|
the default is unlimited.
|
|
May be overridden on a per-service basis with the "max-child"
|
|
parameter.
|
|
.It Fl C Ar rate
|
|
Specify the default maximum number of times a service can be invoked
|
|
from a single IP address in one minute; the default is unlimited.
|
|
May be overridden on a per-service basis with the
|
|
"max-connections-per-ip-per-minute" parameter.
|
|
.It Fl R Ar rate
|
|
Specify the maximum number of times a service can be invoked
|
|
in one minute; the default is 256.
|
|
A rate of 0 allows an unlimited number of invocations.
|
|
.It Fl a
|
|
Specify one specific IP address to bind to.
|
|
Alternatively, a hostname can be specified,
|
|
in which case the IPv4 or IPv6 address
|
|
which corresponds to that hostname is used.
|
|
Usually a hostname is specified when
|
|
.Nm
|
|
is run inside a
|
|
.Xr jail 8 ,
|
|
in which case the hostname corresponds to the
|
|
.Xr jail 8
|
|
environment.
|
|
.Pp
|
|
When hostname specification is used
|
|
and both IPv4 and IPv6 bindings are desired,
|
|
one entry with the appropriate
|
|
.Em protocol
|
|
type for each binding
|
|
is required for each service in
|
|
.Pa /etc/inetd.conf .
|
|
For example,
|
|
a TCP-based service would need two entries,
|
|
one using
|
|
.Dq tcp4
|
|
for the
|
|
.Em protocol
|
|
and the other using
|
|
.Dq tcp6 .
|
|
See the explanation of the
|
|
.Pa /etc/inetd.conf
|
|
.Em protocol
|
|
field below.
|
|
.It Fl p
|
|
Specify an alternate file in which to store the process ID.
|
|
.El
|
|
.Pp
|
|
Upon execution,
|
|
.Nm
|
|
reads its configuration information from a configuration
|
|
file which, by default, is
|
|
.Pa /etc/inetd.conf .
|
|
There must be an entry for each field of the configuration
|
|
file, with entries for each field separated by a tab or
|
|
a space. Comments are denoted by a
|
|
.Dq #
|
|
at the beginning
|
|
of a line. There must be an entry for each field. The
|
|
fields of the configuration file are as follows:
|
|
.Pp
|
|
.Bd -unfilled -offset indent -compact
|
|
service name
|
|
socket type
|
|
protocol
|
|
{wait|nowait}[/max-child[/max-connections-per-ip-per-minute]]
|
|
user[:group][/login-class]
|
|
server program
|
|
server program arguments
|
|
.Ed
|
|
.Pp
|
|
To specify an
|
|
.Tn "ONC RPC" Ns -based
|
|
service, the entry would contain these fields:
|
|
.Pp
|
|
.Bd -unfilled -offset indent -compact
|
|
service name/version
|
|
socket type
|
|
rpc/protocol
|
|
user[:group][/login-class]
|
|
server program
|
|
server program arguments
|
|
.Ed
|
|
.Pp
|
|
There are two types of services that
|
|
.Nm
|
|
can start: standard and TCPMUX.
|
|
A standard service has a well-known port assigned to it;
|
|
it may be a service that implements an official Internet standard or is a
|
|
.Bx Ns -specific
|
|
service.
|
|
As described in
|
|
.Tn RFC 1078 ,
|
|
TCPMUX services are nonstandard services that do not have a
|
|
well-known port assigned to them.
|
|
They are invoked from
|
|
.Nm
|
|
when a program connects to the
|
|
.Dq tcpmux
|
|
well-known port and specifies
|
|
the service name.
|
|
This feature is useful for adding locally-developed servers.
|
|
TCPMUX requests are only accepted when the multiplexor service itself
|
|
is enabled, above and beyond and specific TCPMUX-based servers; see the
|
|
discussion of internal services below.
|
|
.Pp
|
|
The
|
|
.Em service-name
|
|
entry is the name of a valid service in
|
|
the file
|
|
.Pa /etc/services ,
|
|
or the specification of a
|
|
.Ux
|
|
domain socket (see below).
|
|
For
|
|
.Dq internal
|
|
services (discussed below), the service
|
|
name
|
|
should
|
|
be the official name of the service (that is, the first entry in
|
|
.Pa /etc/services ) .
|
|
When used to specify an
|
|
.Tn "ONC RPC" Ns -based
|
|
service, this field is a valid RPC service name in
|
|
the file
|
|
.Pa /etc/rpc .
|
|
The part on the right of the
|
|
.Dq /
|
|
is the RPC version number.
|
|
This
|
|
can simply be a single numeric argument or a range of versions.
|
|
A range is bounded by the low version to the high version -
|
|
.Dq rusers/1-3 .
|
|
For TCPMUX services, the value of the
|
|
.Em service-name
|
|
field consists of the string
|
|
.Dq tcpmux
|
|
followed by a slash and the
|
|
locally-chosen service name.
|
|
The service names listed in
|
|
.Pa /etc/services
|
|
and the name
|
|
.Dq help
|
|
are reserved.
|
|
Try to choose unique names for your TCPMUX services by prefixing them with
|
|
your organization's name and suffixing them with a version number.
|
|
.Pp
|
|
The
|
|
.Em socket-type
|
|
should be one of
|
|
.Dq stream ,
|
|
.Dq dgram ,
|
|
.Dq raw ,
|
|
.Dq rdm ,
|
|
or
|
|
.Dq seqpacket ,
|
|
depending on whether the socket is a stream, datagram, raw,
|
|
reliably delivered message, or sequenced packet socket.
|
|
TCPMUX services must use
|
|
.Dq stream .
|
|
.Pp
|
|
The
|
|
.Em protocol
|
|
must be a valid protocol or
|
|
.Dq unix .
|
|
Examples are
|
|
.Dq tcp
|
|
or
|
|
.Dq udp ,
|
|
both of which imply IPv4 for backward compatibility.
|
|
The names
|
|
.Dq tcp4
|
|
and
|
|
.Dq udp4
|
|
specify IPv4 only.
|
|
The names
|
|
.Dq tcp6
|
|
and
|
|
.Dq udp6
|
|
specify IPv6 only.
|
|
The names
|
|
.Dq tcp46
|
|
and
|
|
.Dq udp46
|
|
specify that the entry accepts both IPv4 and IPv6 connections
|
|
via a wildcard
|
|
.Dv AF_INET6
|
|
socket.
|
|
If it is desired that the service is reachable via T/TCP, one should
|
|
specify
|
|
.Dq tcp/ttcp ,
|
|
which implies IPv4 for backward compatibility.
|
|
The name
|
|
.Dq tcp4/ttcp
|
|
specifies IPv4 only, while
|
|
.Dq tcp6/ttcp
|
|
specifies IPv6 only.
|
|
The name
|
|
.Dq tcp46/ttcp
|
|
specify that the entry accepts both IPv6 and IPv6 connections
|
|
via a wildcard
|
|
.Dv AF_INET6
|
|
socket.
|
|
Rpc based services
|
|
(for which only IPv4 is supported at this time)
|
|
are specified with the
|
|
.Dq rpc/tcp
|
|
or
|
|
.Dq rpc/udp
|
|
service type.
|
|
TCPMUX services must use
|
|
.Dq tcp ,
|
|
.Dq tcp4 ,
|
|
.Dq tcp6
|
|
or
|
|
.Dq tcp46 .
|
|
.Pp
|
|
The
|
|
.Em wait/nowait
|
|
entry specifies whether the server that is invoked by
|
|
.Nm
|
|
will take over
|
|
the socket associated with the service access point, and thus whether
|
|
.Nm
|
|
should wait for the server to exit before listening for new service
|
|
requests.
|
|
Datagram servers must use
|
|
.Dq wait ,
|
|
as they are always invoked with the original datagram socket bound
|
|
to the specified service address.
|
|
These servers must read at least one datagram from the socket
|
|
before exiting.
|
|
If a datagram server connects
|
|
to its peer, freeing the socket so
|
|
.Nm
|
|
can receive further messages on the socket, it is said to be
|
|
a
|
|
.Dq multi-threaded
|
|
server;
|
|
it should read one datagram from the socket and create a new socket
|
|
connected to the peer.
|
|
It should fork, and the parent should then exit
|
|
to allow
|
|
.Nm
|
|
to check for new service requests to spawn new servers.
|
|
Datagram servers which process all incoming datagrams
|
|
on a socket and eventually time out are said to be
|
|
.Dq single-threaded .
|
|
.Xr Comsat 8 ,
|
|
.Pq Xr biff 1
|
|
and
|
|
.Xr talkd 8
|
|
are both examples of the latter type of
|
|
datagram server.
|
|
.Xr Tftpd 8
|
|
is an example of a multi-threaded datagram server.
|
|
.Pp
|
|
Servers using stream sockets generally are multi-threaded and
|
|
use the
|
|
.Dq nowait
|
|
entry.
|
|
Connection requests for these services are accepted by
|
|
.Nm ,
|
|
and the server is given only the newly-accepted socket connected
|
|
to a client of the service.
|
|
Most stream-based services operate in this manner.
|
|
Stream-based servers that use
|
|
.Dq wait
|
|
are started with the listening service socket, and must accept
|
|
at least one connection request before exiting.
|
|
Such a server would normally accept and process incoming connection
|
|
requests until a timeout.
|
|
TCPMUX services must use
|
|
.Dq nowait .
|
|
.Pp
|
|
The maximum number of outstanding child processes (or
|
|
.Dq threads )
|
|
for a
|
|
.Dq nowait
|
|
service may be explicitly specified by appending a
|
|
.Dq /
|
|
followed by the number to the
|
|
.Dq nowait
|
|
keyword.
|
|
Normally
|
|
(or if a value of zero is specified) there is no maximum.
|
|
Otherwise,
|
|
once the maximum is reached, further connection attempts will be
|
|
queued up until an existing child process exits.
|
|
This also works
|
|
in the case of
|
|
.Dq wait
|
|
mode, although a value other than one (the
|
|
default) might not make sense in some cases.
|
|
You can also specify the maximum number of connections per minute
|
|
for a given IP address by appending
|
|
a
|
|
.Dq /
|
|
followed by the number to the maximum number of
|
|
outstanding child processes.
|
|
Once the maximum is reached, further
|
|
connections from this IP address will be dropped until the end of the
|
|
minute.
|
|
.Pp
|
|
The
|
|
.Em user
|
|
entry should contain the user name of the user as whom the server
|
|
should run. This allows for servers to be given less permission
|
|
than root.
|
|
Optional
|
|
.Em group
|
|
part separated by
|
|
.Dq \&:
|
|
allows to specify group name different
|
|
than default group for this user.
|
|
Optional
|
|
.Em login-class
|
|
part separated by
|
|
.Dq /
|
|
allows to specify login class different
|
|
than default
|
|
.Dq daemon
|
|
login class.
|
|
.Pp
|
|
The
|
|
.Em server-program
|
|
entry should contain the pathname of the program which is to be
|
|
executed by
|
|
.Nm
|
|
when a request is found on its socket. If
|
|
.Nm
|
|
provides this service internally, this entry should
|
|
be
|
|
.Dq internal .
|
|
.Pp
|
|
The
|
|
.Em server program arguments
|
|
should be just as arguments
|
|
normally are, starting with argv[0], which is the name of
|
|
the program. If the service is provided internally, the
|
|
.Em service-name
|
|
of the service (and any arguments to it) or the word
|
|
.Dq internal
|
|
should take the place of this entry.
|
|
.Pp
|
|
Currently, the only internal service to take arguments is
|
|
.Dq auth .
|
|
Without options, the service will always return
|
|
.Dq ERROR\ : HIDDEN-USER .
|
|
The available arguments to this service that alter its behavior are:
|
|
.Bl -tag -width indent
|
|
.It Fl d Ar fallback
|
|
Provide a
|
|
.Ar fallback
|
|
username.
|
|
If the real
|
|
.Dq auth
|
|
service is enabled
|
|
(with the
|
|
.Fl r
|
|
option discussed below),
|
|
return this username instead of an error
|
|
when look ups fail
|
|
for either socket credentials or the username.
|
|
If the real
|
|
.Dq auth
|
|
service is disabled,
|
|
return this username for every request.
|
|
This is primarily useful when running this service on a NAT machine.
|
|
.It Fl g
|
|
Instead of returning
|
|
the user's name to the ident requester,
|
|
report a
|
|
username made up of random alphanumeric characters,
|
|
e.g.\&
|
|
.Dq c0c993 .
|
|
The
|
|
.Fl g
|
|
flag overrides not only the user names,
|
|
but also any fallback name,
|
|
.Pa .fakeid
|
|
or
|
|
.Pa .noident
|
|
files.
|
|
.It Fl t Xo
|
|
.Ar sec Ns Op . Ns Ar usec
|
|
.Xc
|
|
Specify a timeout for the service.
|
|
The default timeout is 10.0 seconds.
|
|
.It Fl r
|
|
Offer a real
|
|
.Dq auth
|
|
service, as per RFC 1413.
|
|
All the remaining flags apply only in this case.
|
|
.It Fl i
|
|
Return numeric user IDs instead of usernames.
|
|
.It Fl f
|
|
If the file
|
|
.Pa .fakeid
|
|
exists in the home directory of the identified user, report the username
|
|
found in that file instead of the real username.
|
|
If the username found in
|
|
.Pa .fakeid
|
|
is that of an existing user,
|
|
then the real username is reported.
|
|
If the
|
|
.Fl i
|
|
flag is also given then the username in
|
|
.Pa .fakeid
|
|
is checked against existing user IDs instead.
|
|
.It Fl F
|
|
same as
|
|
.Fl f
|
|
but without the restriction that the username in
|
|
.Pa .fakeid
|
|
must not match an existing user.
|
|
.It Fl n
|
|
If the file
|
|
.Pa .noident
|
|
exists in the home directory of the identified user, return
|
|
.Dq ERROR\ : HIDDEN-USER .
|
|
This overrides any
|
|
.Pa fakeid
|
|
file which might exist.
|
|
.It Fl o Ar osname
|
|
Use
|
|
.Ar osname
|
|
instead of the name of the system as reported by
|
|
.Xr uname 3 .
|
|
.El
|
|
.Pp
|
|
The
|
|
.Nm
|
|
program
|
|
also provides several other
|
|
.Dq trivial
|
|
services internally by use of
|
|
routines within itself. These services are
|
|
.Dq echo ,
|
|
.Dq discard ,
|
|
.Dq chargen
|
|
(character generator),
|
|
.Dq daytime
|
|
(human readable time), and
|
|
.Dq time
|
|
(machine readable time, in the form of the number of seconds since
|
|
midnight, January 1, 1900). All of these services are available in
|
|
both TCP and UDP versions; the UDP versions will refuse service if the
|
|
request specifies a reply port corresponding to any internal service.
|
|
(This is done as a defense against looping attacks; the remote IP address
|
|
is logged.)
|
|
For details of these services, consult the
|
|
appropriate
|
|
.Tn RFC
|
|
document.
|
|
.Pp
|
|
The TCPMUX-demultiplexing service is also implemented as an internal service.
|
|
For any TCPMUX-based service to function, the following line must be included
|
|
in
|
|
.Pa inetd.conf :
|
|
.Bd -literal -offset indent
|
|
tcpmux stream tcp nowait root internal
|
|
.Ed
|
|
.Pp
|
|
When given the
|
|
.Fl l
|
|
option
|
|
.Nm
|
|
will log an entry to syslog each time a connection is accepted, noting the
|
|
service selected and the IP-number of the remote requester if available.
|
|
Unless otherwise specified in the configuration file,
|
|
and in the absence of the
|
|
.Fl W
|
|
and
|
|
.Fl w
|
|
options,
|
|
.Nm
|
|
will log to the
|
|
.Dq daemon
|
|
facility.
|
|
.Pp
|
|
The
|
|
.Nm
|
|
program
|
|
rereads its configuration file when it receives a hangup signal,
|
|
.Dv SIGHUP .
|
|
Services may be added, deleted or modified when the configuration file
|
|
is reread.
|
|
Except when started in debugging mode,
|
|
.Nm
|
|
records its process ID in the file
|
|
.Pa /var/run/inetd.pid
|
|
to assist in reconfiguration.
|
|
.Sh IMPLEMENTATION NOTES
|
|
.Ss TCP Wrappers
|
|
When given the
|
|
.Fl w
|
|
option,
|
|
.Nm
|
|
will wrap all services specified as
|
|
.Dq stream nowait
|
|
or
|
|
.Dq dgram
|
|
except for
|
|
.Dq internal
|
|
services.
|
|
If the
|
|
.Fl W
|
|
option is given, such
|
|
.Dq internal
|
|
services will be wrapped.
|
|
If both options are given, wrapping for both
|
|
internal and external services will be enabled.
|
|
Either wrapping option
|
|
will cause failed connections to be logged to the
|
|
.Dq auth
|
|
syslog facility.
|
|
Adding the
|
|
.Fl l
|
|
flag to the wrapping options will include successful connections in the
|
|
logging to the
|
|
.Dq auth
|
|
facility.
|
|
.Pp
|
|
Note that
|
|
.Nm
|
|
only wraps requests for a
|
|
.Dq wait
|
|
service while no servers are available to service requests.
|
|
Once a
|
|
connection to such a service has been allowed,
|
|
.Nm
|
|
has no control
|
|
over subsequent connections to the service until no more servers
|
|
are left listening for connection requests.
|
|
.Pp
|
|
When wrapping is enabled, the
|
|
.Pa tcpd
|
|
daemon is not required, as that functionality is builtin.
|
|
For more information on TCP Wrappers, see the relevant documentation
|
|
.Pq Xr hosts_access 5 .
|
|
When reading that document, keep in mind that
|
|
.Dq internal
|
|
services have no associated daemon name.
|
|
Therefore, the service name
|
|
as specified in
|
|
.Pa inetd.conf
|
|
should be used as the daemon name for
|
|
.Dq internal
|
|
services.
|
|
.Ss TCPMUX
|
|
.Tn RFC 1078
|
|
describes the TCPMUX protocol:
|
|
``A TCP client connects to a foreign host on TCP port 1. It sends the
|
|
service name followed by a carriage-return line-feed <CRLF>. The
|
|
service name is never case sensitive. The server replies with a
|
|
single character indicating positive (+) or negative (\-)
|
|
acknowledgment, immediately followed by an optional message of
|
|
explanation, terminated with a <CRLF>. If the reply was positive,
|
|
the selected protocol begins; otherwise the connection is closed.''
|
|
The program is passed the TCP connection as file descriptors 0 and 1.
|
|
.Pp
|
|
If the TCPMUX service name begins with a
|
|
.Dq + ,
|
|
.Nm
|
|
returns the positive reply for the program.
|
|
This allows you to invoke programs that use stdin/stdout
|
|
without putting any special server code in them.
|
|
.Pp
|
|
The special service name
|
|
.Dq help
|
|
causes
|
|
.Nm
|
|
to list TCPMUX services in
|
|
.Pa inetd.conf .
|
|
.Ss IPsec
|
|
The implementation includes a tiny hack
|
|
to support IPsec policy settings for each socket.
|
|
A special form of comment line, starting with
|
|
.Dq Li #@ ,
|
|
is interpreted as a policy specifier.
|
|
Everything after the
|
|
.Dq Li #@
|
|
will be used as an IPsec policy string,
|
|
as described in
|
|
.Xr ipsec_set_policy 3 .
|
|
Each
|
|
policy specifier is applied to all the following lines in
|
|
.Pa inetd.conf
|
|
until the next policy specifier.
|
|
An empty policy specifier resets the IPsec policy.
|
|
.Pp
|
|
If an invalid IPsec policy specifier appears in
|
|
.Pa inetd.conf ,
|
|
.Nm
|
|
will provide an error message via the
|
|
.Xr syslog 3
|
|
interface and abort execution.
|
|
.Ss Ux Domain Sockets
|
|
In addition to running services on IP sockets,
|
|
.Nm
|
|
can also manage
|
|
.Ux
|
|
domain sockets.
|
|
To do this you specify a
|
|
.Em protocol
|
|
of
|
|
.Dq unix
|
|
and specify the
|
|
.Ux
|
|
domain socket as the
|
|
.Em service-name .
|
|
The
|
|
.Em service-type
|
|
may be
|
|
.Dq stream
|
|
or
|
|
.Dq dgram .
|
|
The specification of the socket must be
|
|
an absolute path name,
|
|
optionally prefixed by an owner and mode
|
|
of the form
|
|
.Em :user:group:mode: .
|
|
The specification:
|
|
.Pp
|
|
.Dl ":news:daemon:220:/var/run/sock"
|
|
.Pp
|
|
creates a socket owned
|
|
by user
|
|
.Dq news
|
|
in group
|
|
.Dq daemon
|
|
with permissions allowing only that user and group to connect.
|
|
The default owner is the user that
|
|
.Nm
|
|
is running as.
|
|
The default mode only allows the socket's owner to connect.
|
|
.Pp
|
|
.Sy WARNING :
|
|
while creating
|
|
.Ux
|
|
domain socket,
|
|
.Nm
|
|
must change the ownership and permissions on the socket.
|
|
This can only be done securely if
|
|
the directory in which the socket is created
|
|
is writable only by root.
|
|
Do
|
|
.Em NOT
|
|
use
|
|
.Nm
|
|
to create sockets in world writable directories,
|
|
such as
|
|
.Pa /tmp ,
|
|
instead use
|
|
.Pa /var/run
|
|
or a similar directory.
|
|
.Pp
|
|
Internal services may be run on
|
|
.Ux
|
|
domain sockets, in the usual way.
|
|
In this case
|
|
the name of the internal service
|
|
is determined using
|
|
the last component of the socket's pathname.
|
|
.Sh "FILES"
|
|
.Bl -tag -width /var/run/inetd.pid -compact
|
|
.It Pa /etc/inetd.conf
|
|
configuration file
|
|
.It Pa /etc/rpc
|
|
translation of service names to RPC program numbers
|
|
.It Pa /etc/services
|
|
translation of service names to port numbers
|
|
.It Pa /var/run/inetd.pid
|
|
the pid of the currently running
|
|
.Nm
|
|
.El
|
|
.Sh "EXAMPLES"
|
|
Here are several example service entries for the various types of services:
|
|
.Bd -literal
|
|
ftp stream tcp nowait root /usr/libexec/ftpd ftpd -l
|
|
ntalk dgram udp wait root /usr/libexec/ntalkd ntalkd
|
|
telnet stream tcp6 nowait root /usr/libexec/telnetd telnetd
|
|
shell stream tcp46 nowait root /usr/libexec/rshd rshd
|
|
tcpmux/+date stream tcp nowait guest /bin/date date
|
|
tcpmux/phonebook stream tcp nowait guest /usr/local/bin/phonebook phonebook
|
|
rstatd/1-3 dgram rpc/udp wait root /usr/libexec/rpc.rstatd rpc.rstatd
|
|
/var/run/echo stream unix nowait root internal
|
|
#@ ipsec ah/require
|
|
chargen stream tcp nowait root internal
|
|
#@
|
|
.Ed
|
|
.Sh "ERROR MESSAGES"
|
|
The
|
|
.Nm
|
|
server
|
|
logs error messages using
|
|
.Xr syslog 3 .
|
|
Important error messages and their explanations are:
|
|
.Pp
|
|
.Bl -ohang -compact
|
|
.It Xo
|
|
.Ar service Ns / Ns Ar protocol
|
|
.No "server failing (looping), service terminated."
|
|
.Xc
|
|
The number of requests for the specified service in the past minute
|
|
exceeded the limit.
|
|
The limit exists to prevent a broken program
|
|
or a malicious user from swamping the system.
|
|
This message may occur for several reasons:
|
|
.Bl -enum -offset indent
|
|
.It
|
|
There are many hosts requesting the service within a short time period.
|
|
.It
|
|
A broken client program is requesting the service too frequently.
|
|
.It
|
|
A malicious user is running a program to invoke the service in
|
|
a denial-of-service attack.
|
|
.It
|
|
The invoked service program has an error that causes clients
|
|
to retry quickly.
|
|
.El
|
|
.Pp
|
|
Use the
|
|
.Fl R Ar rate
|
|
option,
|
|
as described above, to change the rate limit.
|
|
Once the limit is reached, the service will be
|
|
reenabled automatically in 10 minutes.
|
|
.Pp
|
|
.It Xo
|
|
.Ar service Ns / Ns Ar protocol :
|
|
.No \&No such user
|
|
.Ar user ,
|
|
.No service ignored
|
|
.Xc
|
|
.It Xo
|
|
.Ar service Ns / Ns Ar protocol :
|
|
.No getpwnam :
|
|
.Ar user :
|
|
.No \&No such user
|
|
.Xc
|
|
No entry for
|
|
.Ar user
|
|
exists in the
|
|
.Xr passwd 5
|
|
database.
|
|
The first message
|
|
occurs when
|
|
.Nm
|
|
(re)reads the configuration file.
|
|
The second message occurs when the
|
|
service is invoked.
|
|
.Pp
|
|
.It Xo
|
|
.Ar service :
|
|
.No can't set uid
|
|
.Ar uid
|
|
.Xc
|
|
.It Xo
|
|
.Ar service :
|
|
.No can't set gid
|
|
.Ar gid
|
|
.Xc
|
|
The user or group ID for the entry's
|
|
.Ar user
|
|
field is invalid.
|
|
.Pp
|
|
.It "setsockopt(SO_PRIVSTATE): Operation not supported"
|
|
The
|
|
.Nm
|
|
program attempted to renounce the privileged state associated with a
|
|
socket but was unable to.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr ipsec_set_policy 3 ,
|
|
.Xr hosts_access 5 ,
|
|
.Xr hosts_options 5 ,
|
|
.Xr login.conf 5 ,
|
|
.Xr passwd 5 ,
|
|
.Xr rpc 5 ,
|
|
.Xr services 5 ,
|
|
.Xr comsat 8 ,
|
|
.Xr fingerd 8 ,
|
|
.Xr ftpd 8 ,
|
|
.Xr rexecd 8 ,
|
|
.Xr rlogind 8 ,
|
|
.Xr rpcbind 8 ,
|
|
.Xr rshd 8 ,
|
|
.Xr telnetd 8 ,
|
|
.Xr tftpd 8
|
|
.Rs
|
|
.%A Michael C. St. Johns
|
|
.%T Identification Protocol
|
|
.%O RFC1413
|
|
.Re
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
command appeared in
|
|
.Bx 4.3 .
|
|
TCPMUX is based on code and documentation by Mark Lottor.
|
|
Support for
|
|
.Tn "ONC RPC"
|
|
based services is modeled after that
|
|
provided by
|
|
.Tn SunOS
|
|
4.1.
|
|
The IPsec hack was contributed by the KAME project in 1999.
|
|
The
|
|
.Fx
|
|
TCP Wrappers support first appeared in
|
|
.Fx 3.2 .
|