libc: Purge unneeded cdefs.h

These sys/cdefs.h are not needed. Purge them. They are mostly left-over
from the $FreeBSD$ removal. A few in libc are still required for macros
that cdefs.h defines. Keep those.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D42385

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

libc/gen/getpwent.c: plug warnings about write-only variables

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

libc: Fix the WITH_HESIOD build

Reported by: Daniel Braniss <danny@cs.huji.ac.il>
MFC after: 1 week

libc/nss: Restore iterator state when doing passwd/group lookups

The getpwent(3) and getgrent(3) implementations maintain some internal
iterator state. Interleaved calls to functions which do passwd/group
lookups using a key, such as getpwnam(3), would in some cases clobber
this state, causing a subsequent getpwent() or getgrent() call to
restart iteration from the beginning of the database or to terminate
early. This is particularly troublesome in programming environments
where execution of green threads is interleaved within a single OS
thread.

Take care to restore any iterator state following a keyed lookup. The
"files" provider for the passwd database was already handling this
correctly, but "compat" was not, and both providers had this problem
when accessing the group database.

PR: 252094
Submitted by: Viktor Dukhovni <ietf-dane@dukhovni.org>
MFC after: 1 month

fix integer underflow in getgrnam_r and getpwnam_r

Sometimes nscd(8) will return a 1-byte buffer for a nonexistent entry. This
triggered an integer underflow in grp_unmarshal_func, causing getgrnam_r to
return ERANGE instead of 0.

Fix the user's buffer size check, and add a correct check for a too-small
nscd buffer.

PR: 248932
Event: September 2020 Bugathon
Reviewed by: markj
MFC after: 2 weeks
Sponsored by: Axcient
Differential Revision: https://reviews.freebsd.org/D26204

Fix -Wvoid-pointer-to-enum-cast warnings.

This pattern is used in callbacks with void * data arguments and seems
both relatively uncommon and relatively harmless. Silence the warning
by casting through uintptr_t.

This warning is on by default in Clang 11.

Reviewed by: arichardson
Obtained from: CheriBSD (partial)
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24425

Make pw_scan(3) more compatible with getpwent(3) et. al. when processing
data from /etc/passwd rather than /etc/master.passwd.

The libc getpwent(3) and related functions automatically read master.passwd
when run by root, or passwd when run by a non-root user. When run by non-
root, getpwent() copes with the missing data by setting the corresponding
fields in the passwd struct to known values (zeroes for numbers, or a
pointer to an empty string for literals). When libutil's pw_scan(3) was
used to parse a line without the root-accessible data, it was leaving
garbage in the corresponding fields.

These changes rename the static pw_init() function used by getpwent() and
friends to __pw_initpwd(), and move it into pw_scan.c so that common init
code can be shared between libc and libutil. pw_scan(3) now calls
__pw_initpwd() before __pw_scan(), just like the getpwent() family does, so
that reading an arbitrary passwd file in either format and parsing it with
pw_scan(3) returns the same results as getpwent(3) would.

This also adds a new pw_initpwd(3) function to libutil, so that code which
creates passwd structs from scratch in some manner that doesn't involve
pw_scan() can initialize the struct to the values expected by lots of
existing code, which doesn't expect to encounter NULL pointers or garbage
values in some fields.

libc: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

libc: make some more use of the nitems() macro.

We have an nitems() macro in the <sys/param.h> header that is
convenient to re-use as it makes things easier to read.
Given that it is available already without adding additional
headers and other parts of libc already use it, extend a bit
more its use.

Fix compiling with gcc [4.2.1] after r287797 when MK_HESOID == no and
MK_NIS == no by converting `i` back to an int, and instead cast the loop
comparison to `int`

The loop comparison is iterating the len(ns_dtab)-1, because
the last element is the sentinel tuple { NULL, NULL, NULL, }, so when
both HESOID and NIS are off, len(ns_dtab)-1 == 1 - 1 == 0, and the loop
is skipped because the expression is tautologically false

While here, convert `(sizeof(x) / sizeof(x[0]))` to `nitems(x)`

Tested with: clang 3.7.0, gcc 4.2.1, and gcc 4.9.4 [*] with MK_NIS={no,yes}
and by running bash -lc 'id -u && id -g && id'

* gcc 4.9.4 needs another patch in order for the compile to succeed
with -Werror with lib/libc/gen/getgrent.c

Reported by: jhibbits

Use unsigned variables in a few places.

Eliminates gcc 4.9 warnings.

compat_passwd(): yet another uninitialized access to stayopen.

CID: 1018731

Fix small memleaks in nis_passwd() and nis_group().

These only occur upon error.

Code Review: https://reviews.freebsd.org/D1849
Reviewed by: delphij

CID: 1016715
CID: 1016717

More tidy-ups on uninitialized scalar variable

As a followup to r278363, there is one more case where
stayopen can be accessed uninitialized, but even after
swapping arguments, access is possible in some other
cases so prevent it completely by initializing stayopen.

CID: 1018729
CID: 1018732

Protect uninitialized scalar variable from being accessed

In a couple of cases a variable "stayopen" can be checked
unitialized. This is of no danger as the complementary
condition is false but prevent the access by switching
the checks.

CID: 1018729
CID: 1018732

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

- Import the HEAD csup code which is the basis for the cvsmode work.

- Extend the nsswitch to support Services, Protocols and Rpc
databases.
- Make nsswitch support caching.

Submitted by: Michael Bushkov <bushman__at__rsu.ru>
Sponsored by: Google Summer of Code 2005

POSIX prohibits any library function from setting errno to 0.
Correct my previous commit and add a comment to the manpage
indicating that the user must set errno to 0 if they wish to
distinguish "no such user" from "error".

Pointed out by: Jacques Vidrine (nectar@)

If getpwent/getpwuid/getpwnam return NULL, they must also set errno.

Fix a bug that could result in getpw*() incorrectly returning NULL when NIS
adjunct maps are used. One symtom of this bug is sshd saying:
login_get_lastlog: Cannot find account for uid X
when logging in. The problem here is caused by an incorrect reuse of the rv
variable when previous values are needed later.

Make NULL a (void*)0 whereever possible, and fix the warnings(-Werror)
that this provokes. "Wherever possible" means "In the kernel OR NOT
C++" (implying C).

There are places where (void *) pointers are not valid, such as for
function pointers, but in the special case of (void *)0, agreement
settles on it being OK.

Most of the fixes were NULL where an integer zero was needed; many
of the fixes were NULL where ascii <nul> ('\0') was needed, and a
few were just "other".

Tested on: i386 sparc64

Kill whitespace at end of lines.

Fix a bug that could result in a null pointer dereference in
getpwent(3) or getpwuid(3) when using NIS adjunct maps. The bug was
present in the internal `nis_passwd' function. The lookup in the
adjunct map used the name passed into `nis_passwd', however no name
was of course supplied by getpwent or getpwuid. Correctly use the
name from the `struct pwd' that was found instead.

PR: bin/59962
Submitted by: Gabriel Gomez <ggomez@fing.edu.uy>

Revert to using yp_order() to probe for master.paswd.by* maps and
don't probe the server at all for passwd.by* maps. This fixes
interoperability with the Services For UNIX NIS server (which is
really a front end to Captive^WActiveDirectory). This server
incorrectly returns success for all YPPROC_MASTER requests,
even for maps that don't exist, which makes it impossible to
(ab)use it to probe for the existence of the master.passwd.by*
maps.

This is a little kludgey, but basically restores the original
behavior of getpwent.c as it is in -stable, and works around both
the lack of YPPROC_ORDER on NIS+ servers as well as the broken
YPPROC_MASTER on Services For UNIX servers.

fix NIS+ YP compat mode

PR: bin/52792
Submitted by: TOMITA Yoshinori <yoshint@flab.fujitsu.co.jp>

Back out the `hiding' of strlcpy and strlcat. Several people
vocally objected to this safety belt.

`Hide' strlcpy and strlcat (using the namespace.h / __weak_reference
technique) so that we don't wind up calling into an application's
version if the application defines them.

Inspired by: qpopper's interfering and buggy version of strlcpy

When using `compat' mode, be sure to re-dispatch setpwent, endpwent,
setgrent, and endgrent also. (The previous NSS implementation used to
simply twiddle the internal data of the various modules directly.)

A symptom (group list set incorrectly in sshd) was
Reported by: Glenn Johnson <gjohnson@srrc.ars.usda.gov>

Sponsored by: DARPA, Network Associates Laboratories

In compat mode, we `redispatch' the lookup. It is probably a good
idea to re-initialize `struct passwd', because e.g. pw_class might
get set by one module, but not by another. Add another call to the
internal pwd_init function to accomplish this.

Sponsored by: DARPA, Network Associates Laboratories

Don't try to access the NIS `master' maps unless we have superuser
privileges. To do so may cause the NIS server to log spurious and
annoying `access denied' messages.

Reported by: Philip Paeps <philip@paeps.cx>
Sponsored by: DARPA, Network Associates Laboratories

Follow-up to revision 1.74: Using the result buffer to store our empty
string was an incredibly dumb idea (of course it will be changed by an
NSS module on success!). Use a static empty string instead.

Sponsored by: DARPA, Network Associates Laboratories

Follow-up to revision 1.73: set _PWF_FILES when `compat' source is used
but user is found in local file.

Reported by: Shizuka Kudo <shizukakudo_99@yahoo.com>
Sponsored by: DARPA, Network Associates Laboratories

Don't use `memset' to initialize a struct passwd. A module
may not fill in all fields, and in the case of string fields, this could
cause trouble for applications. (The only likely example is `pw_class',
because this field is not used by all modules in all cases.)

Move initialization of struct passwd from module-specific code to the
dispatch code.

The problem of a NULL pw_class was
Noticed by: Philip Paeps <philip@paeps.cx>
and the c^Htrusty ssh(1) command.
Déjà vu by: getpwent.c revision 1.56

Sponsored by: DARPA, Network Associates Laboratories

Correctly set _PWF_FILES in pw_fields when appropriate.
(_PWF_NIS and _PWF_HESIOD were already being set.)

Reported by: Shizuka Kudo <shizukakudo_99@yahoo.com>
Sponsored by: DARPA, Network Associates Laboratories

Revert the definitions of _PW_KEY* to their previous values. There is
at least one consumer outside of libc and pwd_mkdb.
Adjust the versioning in libc and pwd_mkdb accordingly.

named was the application affected, and that fact was first
Reported by: Zherdev Anatoly <tolyar@mx.ru>

Sponsored by: DARPA, Network Associates Laboratories

The default if nsswitch.conf(5) is not present is supposed to be the
hated `compat' source, not `files'.

Reported by: Philip Paeps <philip@paeps.cx>
Sponsored by: DARPA, Network Associates Laboratories

= Implement thread-safe versions of the getpwent(3) and getgrent(3)
family of functions using the new nsdispatch(3) core. Remove
arbitrary size limits when using the thread-safe versions.

= Re-implement the traditional getpwent(3)/getgrent(3) functions on
top of the thread-safe versions.

= Update the on-disk format of the hashed version of the passwd(5)
databases to allow for versioned entries. The legacy version is
`3'. (Don't ask.)

= Add support for version `4' entries in the passwd(5) database.
Entries in this format are identical to version 3 entries except
that all integers are stored as 32-bit integers in network byte
order (big endian).

= pwd_mkdb is updated to generate both version 3 and version 4
entries.

Sponsored by: DARPA, Network Associates Laboratories

Eliminate 19 warnings in libc (at level WARNS=2) of the
`implicit declaration of function' variety.

Eliminate 61 warnings emitted at WARNS=2 (leaving 53 to go).
Only warnings that could be fixed without changing the generated object
code and without restructuring the source code have been handled.

Reviewed by: /sbin/md5

Fix bug that causes passwd and friends to fail when the user has a '+' in
their passwd file for NIS because _PWF_SOURCE is not set.

Submitted by: amigus (perforce change 10969)

Missed a spot in previous commit.

Sponsored by: DARPA, NAI Labs

(ab)use unused bits in the pw_fields member of struct passwd to record
the source of the data contained in the structure.

Sponsored by: DARPA, NAI Labs

* Remove __P and convert to ANSI prototypes.
* Remove 'register'. (some functions had 7+ register functions...)
* Fix SCM ID's.

Fixed world breakage due to missing include of <sys/cdefs.h> in previous
commit.

Fixed related style bugs:
basename.c: misplaced '#if 0'
dirname.c: misplaced '#if 0'
getgrent.c: missing '#if 0', and tab lossage in vendor id (the previous
commit fixed the complete corruption of the vendor id but
lost a tab)
getpwent.c: missing '#if 0'

Fix FreeBSD IDs.

Explicitly use int32_t for on-disk records for pw_change and pw_expire,
since that is what we use now and this insulates us from any time_t
tweaks here. We can define a record format that uses 64 bit times if/when
we need to.

If the username we are trying to look up in the db files won't fit into
the buffer then act like it doesn't exist. The buffer is always big enough
for any valid username.

PR: 27860
Reviewed by: nectar

Remove _THREAD_SAFE and make libc thread-safe by default by
adding (weak definitions to) stubs for some of the pthread
functions. If the threads library is linked in, the real
pthread functions will pulled in.

Use the following convention for system calls wrapped by the
threads library:
__sys_foo - actual system call
_foo - weak definition to __sys_foo
foo - weak definition to __sys_foo

Change all libc uses of system calls wrapped by the threads
library from foo to _foo. In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde). All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes. <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.

Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE. We have recursive mutexes, but would like to avoid
using them if possible.

Remove uneeded includes of <errno.h> from a few files.

Add $FreeBSD$ to a few files in order to pass commitprep.

Approved by: -arch

Fix bug introduced in previous commit: users obtained via compat mode
had uid, gid set to 0 if not otherwise specified!

Submitted by: eivind

Fix passwd entry `prototypes' in compat mode. I broke this in revision
1.55 when importing nsswitch from NetBSD.

Reported by: Naoki Kobayashi <shibata@geo.titech.ac.jp>

Explicitly initialize _pw_passwd.

Add nsswitch support. By creating an /etc/nsswitch.conf file, you can
configure FreeBSD so that various databases such as passwd and group can be
looked up using flat files, NIS, or Hesiod.

= Hesiod has been added to libc (see hesiod(3)).

= A library routine for parsing nsswitch.conf and invoking callback
functions as specified has been added to libc (see nsdispatch(3)).

= The following C library functions have been modified to use nsdispatch:
. getgrent, getgrnam, getgrgid
. getpwent, getpwnam, getpwuid
. getusershell
. getaddrinfo
. gethostbyname, gethostbyname2, gethostbyaddr
. getnetbyname, getnetbyaddr
. getipnodebyname, getipnodebyaddr, getnodebyname, getnodebyaddr

= host.conf has been removed from src/etc. rc.network has been modified
to warn that host.conf is no longer used at boot time. In addition, if
there is a host.conf but no nsswitch.conf, the latter is created at boot
time from the former.

Obtained from: NetBSD

sprintf -> snprintf paranoia

YP/NIS code: remove unnecessary endgrent() calls which can cause fail on
next try over chroot (descriptor closed). getgrnam() used already handles
endgrent() properly and honors _gr_stayopen. Automatically call
setgroupent(1) when _pw_stayopen is set (for YP/NIS code).

Fix longstanding bug "unused stayopen" introduced in rev1.11

PR: 14201

Don't forget to reset _pw_stepping_yp to 0 before returning. Fixes a bug
where getpwent() would ignore wildcard entries that followed a netgroup
entry.

PR: misc/12999
Submitted by: David Hedley <david@inty.net>

Apply patch for PR #12008: remember to reset _yp_enabled flag in
endpwent() so we don't trip over a NULL db pointer later.

PR: 12008
Submitted by: Valentin Netchayev <netch@lucky.net>

Partial fix for the forking problem: if we can't access the master maps,
try again with the unrestricted map.

PR: bin/10821

Restore old semantics (broken in rev 1.47's buffer overflow fix).

Prevent buffer overflow in getpwnam()

PR: bin/8176
Submitted by: Archie Cobbs <archie@whistle.com>

Replace memory leaking instances of realloc with non-leaking reallocf.
In some cases replace if (a == null) a = malloc(x); else a =
realloc(a, x); with simple reallocf(a, x). Per ANSI-C, this is
guaranteed to be the same thing.

I've been running these on my system here w/o ill effects for some
time. However, the CTM-express is at part 6 of 34 for the CAM
changes, so I've not been able to do a build world with the CAM in the
tree with these changes. Shouldn't impact anything, but...

Don't initialize NIS until it is really necessary. Now, in case of network
or NIS server problems, local user can login without a pause.

Also, -Wsomething cleanup.

XOpen says the void setpwent(void) is correct. Also call setpassent(0)
instead of duplicating code, albeit trivial (inspired by NetBSD).

PR: 5524

Many places in the code NULL is used in integer context, where
plain 0 should be used. This happens to work because we #define
NULL to 0, but is stylistically wrong and can cause problems
for people trying to port bits of code to other environments.

PR: 2752
Submitted by: Arne Henrik Juul <arnej@imf.unit.no>

Fix yet a minor stylistic nit from Bruce.
(`cvs diff -ib' print one new char ;-).

Potential bufferflow in getpwent(), getpwnam() and getpwuid()

PR: bin/4134
Submitted by: nick@foobar.org

Remove minor warning (for -Wall -Wshadow); clarifies code.

Merge from Lite2:
filesystem include updates, duplicate group suppression, cleanups,
filesystem whiteout support (unionfs), bidir popen().

Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch

Fix brain-o in SunOS passwd.adjunct stuff: !strstr(s, "##") is a) bad
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.)

Small yet significant tweaks/cleanups:

- 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.

Add support for detecting and hopefully using the passwd.adjunct.byname
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.

General -Wall warning cleanup, part I.
Submitted-By: Kent Vander Velden <graphix@iastate.edu>

Grrrr... yet another variation on Murphy's Law: the best way to find
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

Very minor tweak:

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

NIS cleanups and fixes, the next generation.

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.

Getpwent() and getservent() can wind up calling free() with
an invalid pointer if a call to yp_first() fails. Closes PR # 964,
and possibly # 952.

Minor cleanup, mostly unused vars and missing #includes.

Another tweak/speedup pass:

- 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.

getgrent.c: adjust _nextypgroup() slightly so that it continues processing
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.)

getpwent.c: turn the code that checks the override caches into a
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.

Do the same sanity checking in _pw_breakout_yp() that we do in
_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.

Make _havemaster() use yp_first() (again) instead of yp_order() to
ward off possible NIS+ evil. (I might be overly paranoid with this,
but it doesn't hurt, so...)

Merge RELENG_2_0_5 into HEAD

Remove trailing whitespace.

in _freecaches(): strdup() allocates us memory -- remember to free it.

Head off potential core dump in _havemaster() (we don't need to free any
memory here: the underlying YP routines handle this one for us).

Better conformance to SunOS behavior: if we can't match a user to one
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.

getpwent.c: fix problem with emacs dumping core when NIS is enabled. Also
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.

Use yp_order() instead of yp_first() in _havemaster() to check for the
presence of the master.passwd.byname map, and remember to free the
returned order value before exiting.

Add calls to endgrent() and endnetgrent() to the end of _createcaches().

Yikes! Fix stupid mistake I made in last commit that made getpwent() ignore
local password entries when YP was enabled. (How the heck did that
get by me!?)

As per Justin T. Gibbs's request, agument the +@netgroup/-@netgroup
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.

Very important sanity checks: today I clobbered all four NIS servers on
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.

Lots of fixes/improvements in the +user substitution handling:

- Have the +@netgroup/-@netgroup caches handle the +user/-user cases too.
- Clean up getpwent() to take advantage of the improved +user/-user handling.

Small cleanups:
- Prepend a '_' to a couple of things
- Make sure YP is enabled in _createcaches()
- Remove a couple of unused/uneeded variables from _createcaches()

Phew! Done at last: getpwent now understands +@netgroup/-@netgroup directives
in addition to the existing NIS substitutions. I may tweak this a bit in
the future, but the important stuff is all here.

Collapsed _masterpw_breakout_yp() and _pw_breakout_yp() into a
single function.

Fixed a rather serious bug that presents itself when FreeBSD is configured
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.

Fix for that last fix... pass the hat. :)

Small fix to _getyppass(): sometimes we can construct the wrong mapname
when looking for master.passwd.whatever.

Some changes for YP password map handling:

- 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.

Fix unbalanced #endif introduced by yesterday's change.

Prevent sites from shooting themselves in the foot while enabling/disabling
YP by disallowing `+' entries as logins in all cases. (This handles the
case of a `+' entry in the password file but YP not running, which should
never happen but is easy enough to check for so we'll apply some
prophylaxis.)

Second half of YP security hole fix. Needs updated password
database in order to operate.

Re-implement YP password file support from scratch. This implementation
correctly handles +user entries and + entries with local overrides.

BSD 4.4 Lite Lib Sources