TTY_NETWORK (network), TTY_DIALUP (dialup), which determine a basic
connection type. TTY_DIALUP in particular will replace the old out of
date heuristic "tty[dD]*" in login.c (and better than the current
hard-coded method).
uid/gid in question was in the cache, but did not exist
in the password file. This causes the -nouser and -nogroup
options to find(1) to only print the first file owned by
an unknown user/group in some cases.
modern FreeBSD systems will syslog properly on older systems that
still name the logging socket "/dev/log". This includes pre-2.2
versions of FreeBSD as well as BSD/OS systems. If the connect to
"/var/run/log" fails, the function now tries to connect to
"/dev/log" as a fallback.
because it's potentially dangerous (think: symlink races). Move
realpath() back to it's original location, and remove getcwd_physical()
by renaming it back to getcwd() and zapping the original getcwd wrapper.
Noticed by: bde
touch duplicate group suppression, but the merge blew away our
duplicate group suppression.
The merge also blew away the -Wall cleanup in rev.1.5, but that
was misformatted, so I didn't restore it.
My changes to preserve errno across free() and close() and to report
fstat() errors properly were blown away.
Updated the FreeBSD changes to match the Lite2 style fixes.
Document that popen() can now create bidirectional pipes and handles.
Note that this needs to be updated since we have a native bidirectional
pipe and don't use socketpair() here.
style and b) the wrong logic. Should be strstr(s, "##") != NULL. (Note
that the passwd.adjunct stuff has not been merged into 2.2 so this bug
is not in that branch.)
The character `#' introduces a comment. Leading spaces and tabs are
ignored: '^[ \t]*#.*\n$'
Count an empty line - only spaces, tabs or newline - also as a comment.
(to be compatibel with password database comments). '^[ \t]*\n$'
for now so that we don't lose library compatibility. Applications should
define _NEW_VFSCONF and use getvfsbyname() instead of new_getvfsbyname()
if they want the new vfsconf interface. Parts of the old interface
(enough to load vfs modules, I hope) are still available.
- Use MAP_FAILED instead of the constant -1 to indicate
failure (required by POSIX).
- Removed flag arguments of '0' (required by POSIX).
- Fixed code which expected an error return of 0.
- Fixed code which thought any address with the high bit set
was an error.
- Check for failure where no checks were present.
Discussed with: bde
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
more manageable and convenient referencing by login.conf (login
class database) and (e.g.) login.access.
This is the first of a group of commits which implements the login
class capabilities database.
- getpwent:
o adjunctbuf should be NUL terminated after copying
o _pw_breakout_yp() needs to know the length of the buffer returned
from YP so it can properly NUL terminate its local buffer.
- getgrent:
o YP buffers should be YPMAXRECORD + 2 bytes long and NUL terminated.
(Previously they were hardcoded to 1024 bytes.)
- getnetgrent:
o YP data should be copied with snprintf(), not sprintf()
These are 2.2 candidates. I will wait a few days to make sure these don't
break anything and then, if there are no objections, move them to the 2.2
branch.
line length limit anymore - now 500 members or 5000 members are
possible. For security group lines longer than 256K will be count as
an error. 256K should be enough for 65536 users.
Support comments (lines that begin with a #) if compiled with
option -DGROUP_IGNORE_COMMENTS.
Fortunately it seems that all system utilities which use getgrent()
functions are dynamically linked executables. So you need only
rebuild libc.so.3.0 if you want this change. Note: if you have
an old X server which depend on libc.so.2.* you should rebuild
libc.so.2.* too.
Not a 2.2 candidate.
copy of insure++, too bad the runtime only works for BSD/OS. :-(
Maybe they'll be so impressed by my initial 15 entry bug report for it
that they'll take the FreeBSD version more seriously. :-) :-)
NIS map which is present on SunOS NIS servers with the SunOS C2 security
hack^Woption installed. I'm convinced that the C2 security option restricts
access to the passwd.adjunct.byname map in the same way that I restrict
access to the master.passwd.{byname,buid} maps (checking for reserved ports),
which means that we should be able to handle passwd.adjunct.byname map
correctly.
If _havemaster() doesn't find a master.passwd.byname map, it will now
test for a passwd.adjunct.byname map before defaulting back to the
standard non-shadowed passwd.{byname,byuid} maps. If _pw_breakout_yp()
sees that the adjunct map was found and the password from the standard
maps starts with ##, it will try to grab the correct password field
from the adjunct map. As with the master.passwd maps, this only happens
if the caller is root, so the shadowing feature is preserved; non-root
users just get back ##username as the encrypted password.
Note that all we do is grab the second field from the passwd.adjunct.byname
entry, which is designated to be the real encrypted password. There are
other auditing fields in the entry but they aren't of much use to us.
Also switched back to using yp_order() to probe for the maps (instead
of yp_first()). The original problem with yp_order() was that it barfed
with NIS+ servers in YP compat mode since they don't support the
YPPROC_ORDER procedure. This condition is handled a bit more gracefully
in yplib now: we can detect the error and just punt on the probing.
Garbage in `eacces' caused the wrong errno to be set for non-EACCES errors.
Garbage in `etxtbsy' caused a semi-random retry strategy for ETXTBSY errors.
Found by: NIST-PCTS. gcc -Wall reported the problem, but -Wall is not
enabled for libc.
1) Rename FNM_ICASE to FNM_CASEFOLD
2) Add FNM_LEADING_DIR
Add proper (unsigned char) casts to tolower().
Use 'char' function argument for proper sign extension
- removed references to nonexistent pathconf-related variables.
- document everything in CTL_MACHDEP(more than in sysctl.8) and
80% of the things in CTL_KERN (same as in sysctl.8).
for gcc >= 2.5 and no-ops for gcc >= 2.6. Converted to use __dead2
or __pure2 where it wasn't already done, except in math.h where use
of __pure was mostly wrong.
in a bunch of man pages.
Use the correct .Bx (BSD UNIX) or .At (AT&T UNIX) macros
instead of explicitly specifying the version in the text
in a bunch of man pages.
Here are the diffs for libc_r to get it one step closer to P1003.1c
These make most of the thread/mutex/condvar structures opaque to the
user. There are three functions which have been renamed with _np
suffixes because they are extensions to P1003.1c (I did them for JAVA,
which needs to suspend/resume threads and also start threads suspended).
I've created a new header (pthread_np.h) for the non-POSIX stuff.
The egrep tags stuff in /usr/src/lib/libc_r/Makefile that I uncommented
doesn't work. I think its best to delete it. I don't think libc_r needs
tags anyway, 'cause most of the source is in libc which does have tags.
also:
Here's the first batch of man pages for the thread functions.
The diff to /usr/src/lib/libc_r/Makefile removes some stuff that was
inherited from /usr/src/lib/libc/Makefile that should only be done with
libc.
also:
I should have sent this diff with the pthread(3) man page.
It allows people to type
make -DWANT_LIBC_R world
to get libc_r built with the rest of the world. I put this in the
pthread(3) man page. The default is still not to build libc_r.
also:
The diff attached adds a pthread(3) man page to /usr/src/share/man/man3.
The idea is that without libc_r installed, this man page will give people
enough info to know that they have to build libc_r.
bugs in your code is to put it in the -stable branch. (Corollary: the
day you discover the bug is the day the Internet decides to route your
telnet session to the repository box via Zimbabwe.)
Remove one bogus free(result) (from _havemaster()) that slipped by me.
Flagged by: phkmalloc
Pointed out to me by: Stefan Esser
In __initdb(), a failure to open the local password database is supposed
to result in a warning message being syslog()ed. This warning is only
supposed to be generated as long as the 'warned' flag hasn't been yet;
once the warning is generated, the flag should be set so that the message
is only syslog()ed once. However, while the state of the flag is checked
properly, the flag's state is never changed, so you always get multiple
warnings instead of just one.
Pointed out by: Peter Wemm
This commit covers the man pages for most of the ANSI library functions.
A few others such as strtol.3 have to mention <sys/types.h> because they
mix ANSI interfaces with less well designed extensions.
getnetgrent.c:
- Catch one bogon that snuck by: in _listmatch(), check for '\0'
rather than '\n'; strings returned from yp_match() are terminated
with a nul, not a newline.
getpwent.c:
- Rip out all of the +inclusion/-exclusion stuff from before and
replace it with something a little less grotty. The main problem
with the old mechanism was that it wasted many cycles processing
NIS entries even after it already knew they were to be exlcuded
(or not included, depending on your pointof view). The highlights
of these changes include:
o Uses an in-memory hash database table to keep track of all the
-@netgroup, -user, and -@group exclusions.
o Tries harder to duplicate the behavior normally obtained when using
NIS inclusions/exclusions on a flat /etc/passwd file (meaning things
come out in much the same order).
o Uses seperate methods for handling getpwent() and getpwnam()/getpwuid()
operations instead of trying to do everything with one general
function, which didn't work as well as I thought it would.
o Uses both getnetgrent() and innetgr() to try to save time where
possible.
o Use only one special token in the local password database
(_PW_KEYYPBYNUM) instead of seperate tokens to mark + and -
entries (and stop using the counter tokens too). If this new
token doesn't exist, the code will make due with the standard
_PW_KEYBYNUM token in order to support older databases that
won't have the new token in them.
All this is an attempt to make this stuff work better in environments
with large NIS passwd databases.
- Clear the _yp_innetgr flag immediately after calling setnetgrent() from
innetgr(). We only need the flag set to temporarily alter setnetgrent()'s
behavior. Previously, it was being cleared too late.
- When in NIS-only mode, innetgr() was wasting time doing unecessary
extra processing after it had already found a match.
- Remember to free memory allocated by the NIS functions during innetgr()
searches.
man pages up to mdoc guidelines and fix some minor formatting glitches.
Also fixed a number of man pages to not abuse the .Xr macro to
display functions and path names and a lot of other junk.
matter much on some systems, but on ftp servers (like wcarchive) where
you run with special stripped group and pwd.db files in the anonymous
ftp /etc, this can be a major speedup for ls(1).
reconnect once using the saved openlog() parameters.
This helps one of the system startup race conditions. If syslogd takes too
long to get going, some daemons can fail the connection and forever log
to the console even though the syslogd is running. That is ..unfortunate..
the statically compiled PS_STRINGS and USRSTACK variables. This prevents
programs using setproctitle from coredumping if the kernel VM is increased,
and stops libkvm users (w, ps, etc) from needing to be recompiled if only
the VM layout changes.
for "fts_open" was wrong. Also, the "fts_info" field of the FTSENT
structure was misleadingly described as containing "flags". Actually, it
contains a single integer value.
in the main text of various man pages.
Thanks to Warner Losh for adding an option to manck to allow
it to scan the entire man page looking for bogus xrefs, instead
of just checking the SEE ALSO section.
Also corrected a few minor formatting errors, file location and cross
references in some of the section 3 man pages.
This shuts up a lot of the output from "manck" for section 3.
Install (optional) libutil.h with prototypes for the functions and
document this in the man page.
minor cleanups to the various routines, include the prototype file, declare
return codes etc.
of signals. Signals are now properly caught, tty state is being
restored, and the previous sigaction triggered. Upon receipt of a
sigcont, echo is turned off again.
SIGTSTP causes a buffer flush, the man page mentions this. (Although
i rather think of it as a feature than a bug.)
This is likely to be my last FreeBSD action for 1995, xearth shows
me that our .au guys must already write 1996. :-)
replace the dozen other various hacks in the code that do all sorts
of crude things including spamming the envrionment strings with the new
argv string.
This version is mainly inspired by the sendmail version, with a couple of
ideas taken from the NetBSD implementation as well.
- Fix buffer overflow problem once and for all: do away with the buffer
copies to 'user' prior to calling _scancaches() and just pass a pointer
to the buffer returned by yp_match()/yp_first()/yp_next()/whatever.
(We turn the first ':' to a NUL first so strcmp() works, then change it
back later. Submitted by Bill Fenner <fenner@parc.xerox.com> and
tweaked slightly by me.
- Give _pw_breakout_yp() the 'more elegant solution' I promised way back when.
Eliminate several copies to static buffers and replace them with just
one copy. (The buffer returned by the NIS functions is at most
YPMAXRECORD bytes long, so we should only need one static buffer of
the same length (plus 2 for paranoia's sake).)
- Also in _pw_breakout_yp(): always set pw.pw_passwd to the username
obtained via NIS regardless of what pw_fields says: usernames cannot
be overridden so we have no choice but to use the name returned by
NIS.
- _Again_ in _pw_breakout_yp(): before doing anything else, check that
the first character of the NIS-returned buffer is not a '+' or '-'.
If it is, drop the entry. (#define EXTRA_PARANOIA 1 :)
- Probe for the master.passwd.* maps once during __initdb() instead
of doing it each time _getyppass() or _nextyppass() is called.
- Don't copy the NIS data buffers to static memory in _getyppass()
and _nextyppass(): this is done in _pw_breakout_yp() now.
- Test against phkmalloc and phkmalloc/2 (TNG!) to make sure we're
free()ing the yp buffers sanely.
- Put _havemaster(), _getyppass() and nextyppass() prototypes under
#ifdef YP. (Somehow they ended up on the wrong side of the #endif.)
- Remove unused variable ___yp_only.
- In some cases, we don't properly resolve _all_ possible group memberships.
If a user is a member of both local and NIS groups, we sometimes lose some
of the membership info from NIS. (Reported by: Thorsten Kukuk
<kukuk@uni-paderborn.de>)
- Make NIS +groupname overrides actually work the way the SunOS group(5)
man page says they should (make them work for all cases: getgrent(),
getgrnam() and getgrgid()).
- When not compiled with -DYP, grscan() should ignore entries that
begin with a '+'. When compiled _with_ -DYP, grscan() should ignore
+groupname entries that don't refer to real NIS groups.
- Remove redundant redeclaration of fgets(), strsep() and index() inside
grscan(). We already #include all the right header files for these.
Note: -groupname exclusion as specified in the Sun documentation still
isn't supported. This'll be a 2.2 addition. Right now I just want this
stuff to work.
What was happening, is if syslogd was not running, syslog() would do
a strcat("\r\n") on a non-null-terminated buffer, and write it to the console.
This meant that sometimes extra characters could be written to the console
during boot, depending on the stack contents.
This totally avoids the potential problem by using writev() like the rest
of the does, and avoid modifying the buffer after the trouble we've gone to
to carefully protect it.
This is actually a trivial fix, in spite of the long commit message.. :-)
It only appeared during boot and shutdown with syslogd stopped.
running on a tty. (Same as isatty()) The old-style TIOCGETP ioctl
wouldn't fly if the kernel didn't have COMPAT_43.
Submitted by: Carl Fongheiser <cmf@netins.net>
control hooks.
It is similar to an unrolled multi-part snprintf(), in that a "FILE *" is
attached to a string buffer. There is also an optimisation for the case
where the syslog format string does not contain %m, which should improve
performance of "informational" logging, like from ftpd.
the group map after encountering a badly formatted entry.
getpwent.c: same as above for _nextyppass(), and also turn a couple of
sprintf()s into snprintf()s to avoid potential buffer overruns. (The
other day I nearly went mad because of a username in my NIS database
that's actually 9 characters long instead of 8. Stuffing a 9-character
username into an 8-character buffer can do some strange things.)
(This reminds me: I hope somebody's planning to fix the buffer overrun
security hole in syslog(3) before 2.1 ships.)
seperate function to avoid duplication. Also fix getpwent() a
small bit to properly handle the case where the magic NIS '+'
entry appears before the end of the password file.
getgrent.c: be a little more SunOS-ish. Make it look like the NIS
group map is 'inserted' at the the point(s) where the magic NIS '+'
entry/entries appear.
getgrent: fix a file descriptor leak: remember to close the netgroup
file after we determine that we're using NIS-only innetgr() lookups.
- getnetgrent.c: address some NIS compatibility problems. We really need
to use the netgroup.byuser and netgroup.byhost maps to speed up innetgr()
when using NIS. Also, change the NIS interaction in the following way:
If /etc/netgroup does not exist or is empty (or contains only the
NIS '+' token), we now use NIS exclusively. This lets us use the
'reverse netgroup' maps and is more or less the behavior of other
platforms.
If /etc/netgroup exists and contains local netgroup data (but no '+').
we use only lthe local stuff and ignore NIS.
If /etc/netgroup exists and contains both local data and the '+',
we use the local data nd the netgroup map as a single combined
database (which, unfortunately, can be slow when the netgroup
database is large). This is what we have been doing up until now.
Head off a potential NULL pointer dereference in the old innetgr()
matching code.
Also fix the way the NIS netgroup map is incorporated into things:
adding the '+' is supposed to make it seem as though the netgroup
database is 'inserted' wherever the '+' is placed. We didn't quite
do it that way before.
(The NetBSD people apparently use a real, honest-to-gosh, netgroup.db
database that works just like the password database. This is
actually a neat idea since netgroups is the sort of thing that
can really benefit from having multi-key search capability,
particularly since reverse lookups require more than a trivial
amount of processing. Should we do something like this too?)
- netgroup.5: document all this stuff.
- rcmd.c: some sleuthing with some test programs linked with my own
version of innetgr() has revealed that SunOS always passes the NIS
domain name to innetgr() in the 'domain' argument. We might as well
do the same (if YP is defined).
- ether_addr.c: also fix the NIS interaction so that placing the
'+' token in the /etc/ethers file makes it seem like the NIS
ethers data is 'inserted' at that point. (Chances are nobody will
notice the effect of this change, which is just te way I like it. :)
_gr_breakout_yp(): if we encounter a NULL pointer generated as the
result of a badly formatted NIS passwd entry (e.g. missing fields),
we punt and return an error code, thereby silently skipping the
bad entry.
last night:
_gr_breakout_yp() doesn't check for badly formatted NIS group entries.
For example, a bogus entry like this:
bootp::user1,user2,user3
will lead to a null pointer dereference and a SEGV (note that the GID
field is missing -- this results in one of the strsep(&result, ":")
returning NULL). The symtpom of this problem is programs dumping
core left and right the moment you add a + entry to /etc/group.
Note that while this is similar to an earlier bug, it's caused by a
different set of circumstances.
The fix is to check for the NULL pointers and have _gr_breakout_yp()
punt and return a failure code if it catches one. This is more or
less the behavior of SunOS: if a bad NIS group entry is encountered,
it's silently ignored. I don't think our standard (non-NIS) group
parsing code behaves the same way. It doesn't crash though, so I'm
citing the 'it ain't broken, don't fix it' rule and leaving it alone.
I'll probably have to add similar checks to _pw_breakout_yp() in
getpwent.c to ward off the same problems. It's rare that bad NIS
map entries like this occur, but we should handle them gracefully
when they do.
'cycle in netgroup check too greedy').
PR #508 is apparently due to an inconsistency in the way the 4.4BSD
netgroup code deals with bad netgroups. When 4.4BSD code encounters
a badly formed netgroup entry (e.g. (somehost,-somedomain), which,
because of the missing comma between the '-' and 'somedomain,' has
only 2 fields instead of 3), it generates an error message and
then bails out without doing any more processing on the netgroup
containing the bad entry. Conversely, every other *NIX in the world
that usees netgroups just tries to parse the entry as best it can
and then silently continues on its way.
The result is that two bad things happen: 1) we ignore other valid entries
within the netgroup containing the bogus entry, which prevents
us from interoperating with other systems that don't behave this way,
and 2) by printing an error to stderr from inside libc, we hose certain
programs, in this case rlogind. In the problem report, Bill Fenner
noted that the 'B' from 'Bad' was missing, and that rlogind exited
immediately after generating the error. The missing 'B' is apparently
not caused by any problem in getnetgrent.c; more likely it's getting
swallowed up by rlogind somehow, and the error message itself causes
rlogind to become confused. I was able to duplicate this problem and
discovered that running a simple test program on my FreeBSD system
resulted in a properly formatted (if confusing) error, whereas triggering
the error by trying to rlogin to the machine yielded the missing 'B'
problem.
Anyway, the fixes for this are as follows:
- The error message has been reformatted so that it prints out more useful
information (e.g. Bad entry (somehost,-somedomain) in netgroup "foo").
We check for NULL entries so that we don't print '(null)' anymore too. :)
- Rearranged things in parse_netgrp() so that we make a best guess at
what bad entries are supposed to look like and then continue processing
instead of bailing out.
- Even though the error message has been cleaned up, it's wrapped inside
a #ifdef DEBUG. This way we match the behavior of other systems. Since we
now handle the error condition better anyway, this error message becomes
less important.
PR #507 is another case of inconsistency. The code that handles
duplicate/circular netgroup entries isn't really 'too greedy; -- it's
just too noisy. If you have a netgroup containing duplicate entries,
the code actually does the right thing, but it also generates an error
message. As with the 'Bad netgroup' message, spewing this out from
inside libc can also hose certain programs (like rlogind). Again, no
other system generates an error message in this case.
The only change here is to hide the error message inside an #ifdef DEBUG.
Like the other message, it's largely superfluous since the code handles
the condition correctly.
Note that PR #510 (+@netgroup host matching in /etc/hosts.equiv) is still
being investigated. I haven't been able to duplicate it myself, and I
strongly suspect it to be a configuration problem of some kind. However,
I'm leaving all three PRs open until I get 510 resolved just for the
sake of paranoia.
- If you take the wheel entry out of /etc/group and turn on NIS,
the '+:*::' line is incorrectly flagged as the entry for wheel (the
empty gid section is translated to 0), hence getgrgid() returns '+'
as the name of the group instead of 'wheel.'
- Using just '+:' as the 'turn on NIS' switch in /etc/group makes
getgrgid() dump core because of a null pointer dereference. (Last
time I was in here, I foolishly assumed that fixing the core dump
problems with getgrnam() and getgrent() would fix getgrgid() too.
Silly me.)
- it succeeded on non-directories (see POSIX 5.1.2.4).
- it hung on (non-open) named pipes.
- it leaked memory if the second malloc() failed.
- it didn't preserve errno across errors in close().
of the plus or minus lists at all, reject him. This lets you create
a +@netgroup list of users that you want to admit and reject everybody
else. If you end your +@netgroup list with the wildcard line
(+:::::::::) then you'll have a +@netgroup list that remaps the
specified people but leaves people not in any netgroup unaffected.
add #includes for YP headers when compiling with -DYP to avoid some implicit
declarations.
getgrent.c & getnetgrent.c: add some #includes to avoid implicit declarations
of YP functions.
remapping mechanism in the following manner: if given an entry +@foo
and there is no netgroup named 'foo,' try searching for a regular
user group called 'foo' and build the cache using the members of
group 'foo' instead. If both a netgroup 'foo' and a user group 'foo'
exist, the 'foo' netgroup takes precedence, since we're primarily
interested in netgroup matching anyway.
This allows access control schemes based on ordinary user groups
(which are also available via NIS) rather than netgroups, since
netgroups on some systems are limited in really brain-damaged ways.
my network because setnetgrent() was trying to do a lookup on group "".
It seems that an attempt to do a yp_match() (and possible yp_next())
on a null or empty key causes Sun's ypserv in SunOS 4.1.3 to exit
suddenly (and without warning). Our ypserv behaves badly in this
situation too, thoush it doesn't appear to crash. In any event, getpwent,
getnetgrent and yp_match() and yp_next() are now extra careful not to
accidentally pass on null or empty arguments.
Also made a small change to getpwent.c to allow +::::::::: wildcarding,
which I had disabled previously.
- Have the +@netgroup/-@netgroup caches handle the +user/-user cases too.
- Clean up getpwent() to take advantage of the improved +user/-user handling.
work because parse_netgrp() doesn't recurse properly. Fixed by
changing
if (parse_netgrp(spos))
return(1);
to
if (parse_netgrp(spos))
continue;
inside parse_netgrp(). (Lucky for me I happen to have a fairly complex
'live' netgroup database to test this stuff with.)
- Added support for reading netgroups from NIS/YP in addition to the
local /etc/netgroups file. (Note that SunOS and many other systems only
support reading netgroups via NIS, which is a bit odd.)
- Fix Evil Null Pointer Dereferences From Hell (tm) that caused
parse_netgrp() to SEGV when expanding netgroups that include
references to other netgroups. Funny how nobody else noticed this.
This is the first step in implimenting +@netgroup substitution in
getpwent.c and any other places that could use it and don't already
support it (which is probably everywhere).
by heading off possible null pointer dereferences in grscan(). Also
change getgrnam() slightly to properly handle the change: if grscan()
returns an rval of 1 and leaves a '+' in the gr_name field and YP is
enabled, poll the YP group.byname map before giving up. This should
insure that we make every effort to find a match in the local and
YP group databases before bailing out.
in an (unlikely) border case (maxgroups==1 and the user is on
an /etc/group line for the same group and that group only ...).
Now this case is dealt with as before ...
Add a missing apostrophe that suggests inverting the frequency to get
tick size. It read better before because `CLK_TCK' suggests a tick
size although it is actually a frequency.
as an NIS client. The pw_breakout_yp routines that are used to populate the
_pw_passwd structire only do anything if the bits in the pw_fields member
_pw_passwd are cleared. Unfortunately, we can get into a state where
pw_fields has garbage in it right before the YP lookup functions are
called, which causes the breakout functions to screw up in a big way.
Here's how to duplicate the problem:
- Configure FreeBSD as an NIS client
- Log in as a user who's password database records reside only in
the NIS passwd maps.
- Type ps -aux
Result: your processes appear to be owned by 'root' or 'deamon.'
/bin/ls can exhibit the same problem.
The reason this happens:
- When ps(1) needs to match a username to a UID, it calls getpwuid().
- root is in the local password file, so getpwuid() calls __hashpw()
and __hashpw() populates the _pw_passwd struct, including the pw_fields
member. This happens before NIS lookups take place because, by coincidence,
ps(1) tends to display processes owned by root before it happens upon
a proccess owned by you.
- When your UID comes up, __hashpw() fails to find your entry in the
local password database, so it bails out, BUT THE BITS IN THE pw_fields
STRUCTURE OF _pw_passwd ARE NEVER CLEARED AND STILL CONTAIN INFORMATION
FROM THE PREVIOUS CALL TO __hash_pw()!!
- If we have NIS enabled, the NIS lookup functions are called.
- The pw_breakout_yp routines see that the pw_fields bits are set and
decline to place the data retrieved from the NIS passwd maps into the
_pw_passwd structure.
- getpwuid() returns the results of the last __hashpw() lookup instead
of the valid NIS data.
- Hijinxs ensue when user_from_uid() caches this bogus information and
starts handing out the wrong usernames.
AAAARRRRRRRRRGGGGGGHHHHHHHHHH!!!
*Please* don't tell me I'm the only person to have noticed this.
Fixed by having __hashpw() check the state of pw_fields just before
bailing out on a failed lookup and clearing away any leftover garbage.
What a fun way to spend an afternoon.
- FreeBSD's NIS server can supply a master.passwd map, which has
more fields in it than a standard passwd map, so we need a
_master_pw_breakout() fuction.
- When doing passwd map lookups, look for master.passwd.* by attempting
a _yp_first() on master.passwd.byname. If it exists, we're being served
by a FreeBSD NIS server and we should use this map.
- If we aren't the superuser, retrieve only the standard passwd maps.
If we're being served by a FreeBSD system, then the passwd map has
no passwords in it, and it won't serve us the master.passwd map unless
we're superuser anyway.
There's a small speed hit for the superuser inherent in the check for
the master.passwd map, but this lets us dynamically decide what to do
rather than rely on a non-standard config file somewhere. Since all
of this is bypassed for normal users, they shouldn't notice the
difference.
