a3287587cb
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.
543 lines
12 KiB
C
543 lines
12 KiB
C
/*
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* Copyright (c) 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)getpwent.c 8.1 (Berkeley) 6/4/93";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/param.h>
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#include <fcntl.h>
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#include <db.h>
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#include <syslog.h>
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#include <pwd.h>
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#include <utmp.h>
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#include <errno.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <string.h>
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#include <limits.h>
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static struct passwd _pw_passwd; /* password structure */
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static DB *_pw_db; /* password database */
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static int _pw_keynum; /* key counter */
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static int _pw_stayopen; /* keep fd's open */
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#ifdef YP
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static struct passwd _pw_copy;
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static int _yp_enabled; /* set true when yp enabled */
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static int _pw_stepping_yp; /* set true when stepping thru map */
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#endif
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static int __hashpw(), __initdb();
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static int _havemaster(const char *);
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static int _getyppass(struct passwd *, const char *, const char *);
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static int _nextyppass(struct passwd *);
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struct passwd *
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getpwent()
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{
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DBT key;
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char bf[sizeof(_pw_keynum) + 1];
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int rv;
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if (!_pw_db && !__initdb())
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return((struct passwd *)NULL);
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#ifdef YP
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if(_pw_stepping_yp) {
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_pw_passwd = _pw_copy;
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return (_nextyppass(&_pw_passwd) ? &_pw_passwd : 0);
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}
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#endif
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tryagain:
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++_pw_keynum;
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bf[0] = _PW_KEYBYNUM;
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bcopy((char *)&_pw_keynum, bf + 1, sizeof(_pw_keynum));
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key.data = (u_char *)bf;
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key.size = sizeof(_pw_keynum) + 1;
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rv = __hashpw(&key);
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if(!rv) return (struct passwd *)NULL;
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#ifdef YP
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if(_pw_passwd.pw_name[0] == '+' && _pw_passwd.pw_name[1]) {
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_getyppass(&_pw_passwd, &_pw_passwd.pw_name[1],
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"passwd.byname");
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} else if(_pw_passwd.pw_name[0] == '+') {
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_pw_copy = _pw_passwd;
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return (_nextyppass(&_pw_passwd) ? &_pw_passwd : 0);
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}
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#else
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/* Ignore YP password file entries when YP is disabled. */
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if(_pw_passwd.pw_name[0] == '+') {
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goto tryagain;
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}
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#endif
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return(&_pw_passwd);
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}
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struct passwd *
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getpwnam(name)
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const char *name;
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{
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DBT key;
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int len, rval;
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char bf[UT_NAMESIZE + 2];
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if (!_pw_db && !__initdb())
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return((struct passwd *)NULL);
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bf[0] = _PW_KEYBYNAME;
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len = strlen(name);
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bcopy(name, bf + 1, MIN(len, UT_NAMESIZE));
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key.data = (u_char *)bf;
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key.size = len + 1;
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rval = __hashpw(&key);
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#ifdef YP
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if (!rval && _yp_enabled) {
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bf[1] = '+';
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bcopy(name, bf + 2, MIN(len, UT_NAMESIZE - 1));
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key.data = (u_char *)bf;
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key.size = len + 2;
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rval = __hashpw(&key);
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if (!rval && _yp_enabled < 0) {
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key.size = 2;
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rval = __hashpw(&key);
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}
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if(rval)
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rval = _getyppass(&_pw_passwd, name, "passwd.byname");
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}
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#endif
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/*
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* Prevent login attempts when YP is not enabled but YP entries
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* are in /etc/master.passwd.
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*/
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if (rval && _pw_passwd.pw_name[0] == '+') rval = 0;
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if (!_pw_stayopen) {
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(void)(_pw_db->close)(_pw_db);
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_pw_db = (DB *)NULL;
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}
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return(rval ? &_pw_passwd : (struct passwd *)NULL);
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}
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struct passwd *
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#ifdef __STDC__
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getpwuid(uid_t uid)
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#else
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getpwuid(uid)
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int uid;
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#endif
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{
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DBT key;
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int keyuid, rval;
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char bf[sizeof(keyuid) + 1];
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if (!_pw_db && !__initdb())
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return((struct passwd *)NULL);
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bf[0] = _PW_KEYBYUID;
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keyuid = uid;
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bcopy(&keyuid, bf + 1, sizeof(keyuid));
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key.data = (u_char *)bf;
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key.size = sizeof(keyuid) + 1;
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rval = __hashpw(&key);
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#ifdef YP
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if (!rval && _yp_enabled) {
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char ypbuf[16]; /* big enough for 32-bit uids and then some */
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snprintf(ypbuf, sizeof ypbuf, "%u", (unsigned)uid);
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rval = _getyppass(&_pw_passwd, ypbuf, "passwd.byuid");
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}
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#endif
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if (!_pw_stayopen) {
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(void)(_pw_db->close)(_pw_db);
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_pw_db = (DB *)NULL;
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}
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return(rval ? &_pw_passwd : (struct passwd *)NULL);
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}
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int
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setpassent(stayopen)
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int stayopen;
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{
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_pw_keynum = 0;
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#ifdef YP
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_pw_stepping_yp = 0;
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#endif
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_pw_stayopen = stayopen;
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return(1);
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}
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int
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setpwent()
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{
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_pw_keynum = 0;
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#ifdef YP
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_pw_stepping_yp = 0;
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#endif
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_pw_stayopen = 0;
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return(1);
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}
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void
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endpwent()
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{
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_pw_keynum = 0;
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#ifdef YP
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_pw_stepping_yp = 0;
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#endif
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if (_pw_db) {
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(void)(_pw_db->close)(_pw_db);
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_pw_db = (DB *)NULL;
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}
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}
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static
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__initdb()
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{
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static int warned;
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char *p;
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p = (geteuid()) ? _PATH_MP_DB : _PATH_SMP_DB;
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_pw_db = dbopen(p, O_RDONLY, 0, DB_HASH, NULL);
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if (_pw_db) {
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#ifdef YP
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DBT key, data;
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char buf[] = { _PW_KEYYPENABLED };
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key.data = buf;
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key.size = 1;
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if ((_pw_db->get)(_pw_db, &key, &data, 0)) {
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_yp_enabled = 0;
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} else {
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/* Distinguish between old and new versions of
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pwd_mkdb. */
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if(data.size != 1) {
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_yp_enabled = -1;
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} else {
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_yp_enabled = (int)*((char *)data.data) - 2;
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}
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}
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#endif
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return(1);
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}
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if (!warned)
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syslog(LOG_ERR, "%s: %m", p);
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return(0);
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}
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static
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__hashpw(key)
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DBT *key;
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{
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register char *p, *t;
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static u_int max;
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static char *line;
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DBT data;
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/*
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* XXX The pw_fields member of _pw_passwd needs to be cleared
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* at some point since __hashpw() can be called several times in
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* a single program. If we leave here after the second invokation
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* with garbage data in pw_fields, it can totally screw up NIS
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* lookups (the pw_breakout functions only populate the pw_passwd
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* structure if the pw_fields bits are clear).
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*/
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if ((_pw_db->get)(_pw_db, key, &data, 0)) {
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if (_pw_passwd.pw_fields)
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_pw_passwd.pw_fields = 0;
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return(0);
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}
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p = (char *)data.data;
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if (data.size > max && !(line = realloc(line, max += 1024))) {
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if (_pw_passwd.pw_fields)
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_pw_passwd.pw_fields = 0;
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return(0);
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}
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t = line;
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#define EXPAND(e) e = t; while (*t++ = *p++);
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EXPAND(_pw_passwd.pw_name);
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EXPAND(_pw_passwd.pw_passwd);
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bcopy(p, (char *)&_pw_passwd.pw_uid, sizeof(int));
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p += sizeof(int);
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bcopy(p, (char *)&_pw_passwd.pw_gid, sizeof(int));
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p += sizeof(int);
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bcopy(p, (char *)&_pw_passwd.pw_change, sizeof(time_t));
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p += sizeof(time_t);
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EXPAND(_pw_passwd.pw_class);
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EXPAND(_pw_passwd.pw_gecos);
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EXPAND(_pw_passwd.pw_dir);
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EXPAND(_pw_passwd.pw_shell);
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bcopy(p, (char *)&_pw_passwd.pw_expire, sizeof(time_t));
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p += sizeof(time_t);
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bcopy(p, (char *)&_pw_passwd.pw_fields, sizeof _pw_passwd.pw_fields);
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p += sizeof _pw_passwd.pw_fields;
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return(1);
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}
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#ifdef YP
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static void
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_pw_breakout_yp(struct passwd *pw, char *result)
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{
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char *s;
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s = strsep(&result, ":"); /* name */
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if(!(pw->pw_fields & _PWF_NAME) || (pw->pw_name[0] == '+')) {
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pw->pw_name = s;
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pw->pw_fields |= _PWF_NAME;
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}
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s = strsep(&result, ":"); /* password */
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if(!(pw->pw_fields & _PWF_PASSWD)) {
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pw->pw_passwd = s;
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pw->pw_fields |= _PWF_PASSWD;
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}
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s = strsep(&result, ":"); /* uid */
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if(!(pw->pw_fields & _PWF_UID)) {
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pw->pw_uid = atoi(s);
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pw->pw_fields |= _PWF_UID;
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}
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s = strsep(&result, ":"); /* gid */
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if(!(pw->pw_fields & _PWF_GID)) {
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pw->pw_gid = atoi(s);
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pw->pw_fields |= _PWF_GID;
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}
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s = strsep(&result, ":"); /* gecos */
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if(!(pw->pw_fields & _PWF_GECOS)) {
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pw->pw_gecos = s;
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pw->pw_fields |= _PWF_GECOS;
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}
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s = strsep(&result, ":"); /* dir */
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if(!(pw->pw_fields & _PWF_DIR)) {
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pw->pw_dir = s;
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pw->pw_fields |= _PWF_DIR;
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}
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s = strsep(&result, ":"); /* shell */
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if(!(pw->pw_fields & _PWF_SHELL)) {
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pw->pw_shell = s;
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pw->pw_fields |= _PWF_SHELL;
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}
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}
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static void
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_masterpw_breakout_yp(struct passwd *pw, char *result)
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{
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char *s;
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s = strsep(&result, ":"); /* name */
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if(!(pw->pw_fields & _PWF_NAME) || (pw->pw_name[0] == '+')) {
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pw->pw_name = s;
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pw->pw_fields |= _PWF_NAME;
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}
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s = strsep(&result, ":"); /* password */
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if(!(pw->pw_fields & _PWF_PASSWD)) {
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pw->pw_passwd = s;
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pw->pw_fields |= _PWF_PASSWD;
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}
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s = strsep(&result, ":"); /* uid */
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if(!(pw->pw_fields & _PWF_UID)) {
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pw->pw_uid = atoi(s);
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pw->pw_fields |= _PWF_UID;
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}
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s = strsep(&result, ":"); /* gid */
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if(!(pw->pw_fields & _PWF_GID)) {
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pw->pw_gid = atoi(s);
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pw->pw_fields |= _PWF_GID;
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}
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s = strsep(&result, ":"); /* class */
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if(!(pw->pw_fields & _PWF_CLASS)) {
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pw->pw_class = s;
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pw->pw_fields |= _PWF_CLASS;
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}
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s = strsep(&result, ":"); /* change */
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if(!(pw->pw_fields & _PWF_CHANGE)) {
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pw->pw_change = atol(s);
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pw->pw_fields |= _PWF_CHANGE;
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}
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s = strsep(&result, ":"); /* expire */
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if(!(pw->pw_fields & _PWF_EXPIRE)) {
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pw->pw_expire = atol(s);
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pw->pw_fields |= _PWF_EXPIRE;
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}
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s = strsep(&result, ":"); /* gecos */
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if(!(pw->pw_fields & _PWF_GECOS)) {
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pw->pw_gecos = s;
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pw->pw_fields |= _PWF_GECOS;
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}
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s = strsep(&result, ":"); /* dir */
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if(!(pw->pw_fields & _PWF_DIR)) {
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pw->pw_dir = s;
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pw->pw_fields |= _PWF_DIR;
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}
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s = strsep(&result, ":"); /* shell */
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if(!(pw->pw_fields & _PWF_SHELL)) {
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pw->pw_shell = s;
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pw->pw_fields |= _PWF_SHELL;
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}
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}
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static char *_pw_yp_domain;
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static int
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_havemaster(const char *_pw_yp_domain)
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{
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char *result;
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static char *key;
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int resultlen;
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static int keylen;
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if (yp_first(_pw_yp_domain, "master.passwd.byname",
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&key, &keylen, &result, &resultlen))
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return 0;
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return 1;
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}
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static int
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_getyppass(struct passwd *pw, const char *name, const char *map)
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{
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char *result, *s;
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static char resultbuf[1024];
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int resultlen;
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char mastermap[1024];
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int gotmaster = 0;
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if(!_pw_yp_domain) {
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if(yp_get_default_domain(&_pw_yp_domain))
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return 0;
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}
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sprintf(mastermap,"%s",map);
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/* Don't even bother with this if we aren't root. */
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if (!geteuid())
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if (_havemaster(_pw_yp_domain)) {
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sprintf(mastermap,"master.%s", map);
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gotmaster++;
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}
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if(yp_match(_pw_yp_domain, &mastermap, name, strlen(name),
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&result, &resultlen))
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return 0;
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s = strchr(result, '\n');
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if(s) *s = '\0';
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if(resultlen >= sizeof resultbuf) return 0;
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strcpy(resultbuf, result);
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result = resultbuf;
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if (gotmaster)
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_masterpw_breakout_yp(pw, resultbuf);
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else
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_pw_breakout_yp(pw, resultbuf);
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return 1;
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}
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static int
|
|
_nextyppass(struct passwd *pw)
|
|
{
|
|
static char *key;
|
|
static int keylen;
|
|
char *lastkey, *result;
|
|
static char resultbuf[1024];
|
|
int resultlen;
|
|
int rv;
|
|
char *map = "passwd.byname";
|
|
int gotmaster = 0;
|
|
|
|
if(!_pw_yp_domain) {
|
|
if(yp_get_default_domain(&_pw_yp_domain))
|
|
return 0;
|
|
}
|
|
|
|
/* Don't even bother with this if we aren't root. */
|
|
if (!geteuid())
|
|
if(_havemaster(_pw_yp_domain)) {
|
|
map = "master.passwd.byname";
|
|
gotmaster++;
|
|
}
|
|
|
|
if(!_pw_stepping_yp) {
|
|
if(key) free(key);
|
|
rv = yp_first(_pw_yp_domain, map,
|
|
&key, &keylen, &result, &resultlen);
|
|
if(rv) {
|
|
return 0;
|
|
}
|
|
_pw_stepping_yp = 1;
|
|
goto unpack;
|
|
} else {
|
|
tryagain:
|
|
lastkey = key;
|
|
rv = yp_next(_pw_yp_domain, map, key, keylen,
|
|
&key, &keylen, &result, &resultlen);
|
|
free(lastkey);
|
|
unpack:
|
|
if(rv) {
|
|
_pw_stepping_yp = 0;
|
|
return 0;
|
|
}
|
|
|
|
if(resultlen > sizeof(resultbuf)) {
|
|
free(result);
|
|
goto tryagain;
|
|
}
|
|
|
|
strcpy(resultbuf, result);
|
|
free(result);
|
|
if(result = strchr(resultbuf, '\n')) *result = '\0';
|
|
if (gotmaster)
|
|
_masterpw_breakout_yp(pw, resultbuf);
|
|
else
|
|
_pw_breakout_yp(pw, resultbuf);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
#endif /* YP */
|