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freebsd/lib/libc/gen/getpwent.c
Poul-Henning Kamp d030d2d2ae 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>
1997-09-18 14:08:40 +00:00

836 lines
19 KiB
C

/*
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getpwent.c 8.2 (Berkeley) 4/27/95";
#endif /* LIBC_SCCS and not lint */
#include <stdio.h>
#include <sys/param.h>
#include <fcntl.h>
#include <db.h>
#include <syslog.h>
#include <pwd.h>
#include <utmp.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <grp.h>
extern void setnetgrent __P(( char * ));
extern int getnetgrent __P(( char **, char **, char ** ));
extern int innetgr __P(( const char *, const char *, const char *, const char * ));
/*
* The lookup techniques and data extraction code here must be kept
* in sync with that in `pwd_mkdb'.
*/
static struct passwd _pw_passwd; /* password structure */
static DB *_pw_db; /* password database */
static int _pw_keynum; /* key counter */
static int _pw_stayopen; /* keep fd's open */
#ifdef YP
#include <rpc/rpc.h>
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>
static struct passwd _pw_copy;
static DBT empty = { NULL, 0 };
static DB *_ypcache = (DB *)NULL;
static int _yp_exclusions = 0;
static int _yp_enabled; /* set true when yp enabled */
static int _pw_stepping_yp; /* set true when stepping thru map */
static char _ypnam[YPMAXRECORD];
#define YP_HAVE_MASTER 2
#define YP_HAVE_ADJUNCT 1
#define YP_HAVE_NONE 0
static int _gotmaster;
static char *_pw_yp_domain;
static inline int unwind __P(( char * ));
static inline void _ypinitdb __P(( void ));
static int _havemaster __P((char *));
static int _getyppass __P((struct passwd *, const char *, const char * ));
static int _nextyppass __P((struct passwd *));
#endif
static int __hashpw(), __initdb();
struct passwd *
getpwent()
{
DBT key;
char bf[sizeof(_pw_keynum) + 1];
int rv;
if (!_pw_db && !__initdb())
return((struct passwd *)NULL);
#ifdef YP
if(_pw_stepping_yp) {
_pw_passwd = _pw_copy;
if (unwind((char *)&_ypnam))
return(&_pw_passwd);
}
#endif
tryagain:
++_pw_keynum;
bf[0] = _PW_KEYBYNUM;
bcopy((char *)&_pw_keynum, bf + 1, sizeof(_pw_keynum));
key.data = (u_char *)bf;
key.size = sizeof(_pw_keynum) + 1;
rv = __hashpw(&key);
if(!rv) return (struct passwd *)NULL;
#ifdef YP
if(_pw_passwd.pw_name[0] == '+' || _pw_passwd.pw_name[0] == '-') {
bzero((char *)&_ypnam, sizeof(_ypnam));
bcopy(_pw_passwd.pw_name, _ypnam,
strlen(_pw_passwd.pw_name));
_pw_copy = _pw_passwd;
if (unwind((char *)&_ypnam) == 0)
goto tryagain;
else
return(&_pw_passwd);
}
#else
/* Ignore YP password file entries when YP is disabled. */
if(_pw_passwd.pw_name[0] == '+' || _pw_passwd.pw_name[0] == '-') {
goto tryagain;
}
#endif
return(&_pw_passwd);
}
struct passwd *
getpwnam(name)
const char *name;
{
DBT key;
int len, rval;
char bf[UT_NAMESIZE + 2];
if (!_pw_db && !__initdb())
return((struct passwd *)NULL);
bf[0] = _PW_KEYBYNAME;
len = strlen(name);
bcopy(name, bf + 1, MIN(len, UT_NAMESIZE));
key.data = (u_char *)bf;
key.size = len + 1;
rval = __hashpw(&key);
#ifdef YP
if (!rval && _yp_enabled)
rval = _getyppass(&_pw_passwd, name, "passwd.byname");
#endif
/*
* Prevent login attempts when YP is not enabled but YP entries
* are in /etc/master.passwd.
*/
if (rval && (_pw_passwd.pw_name[0] == '+'||
_pw_passwd.pw_name[0] == '-')) rval = 0;
endpwent();
return(rval ? &_pw_passwd : (struct passwd *)NULL);
}
struct passwd *
getpwuid(uid)
uid_t uid;
{
DBT key;
int keyuid, rval;
char bf[sizeof(keyuid) + 1];
if (!_pw_db && !__initdb())
return((struct passwd *)NULL);
bf[0] = _PW_KEYBYUID;
keyuid = uid;
bcopy(&keyuid, bf + 1, sizeof(keyuid));
key.data = (u_char *)bf;
key.size = sizeof(keyuid) + 1;
rval = __hashpw(&key);
#ifdef YP
if (!rval && _yp_enabled) {
char ypbuf[16]; /* big enough for 32-bit uids and then some */
snprintf(ypbuf, sizeof ypbuf, "%u", (unsigned)uid);
rval = _getyppass(&_pw_passwd, ypbuf, "passwd.byuid");
}
#endif
/*
* Prevent login attempts when YP is not enabled but YP entries
* are in /etc/master.passwd.
*/
if (rval && (_pw_passwd.pw_name[0] == '+'||
_pw_passwd.pw_name[0] == '-')) rval = 0;
endpwent();
return(rval ? &_pw_passwd : (struct passwd *)NULL);
}
int
setpassent(stayopen)
int stayopen;
{
_pw_keynum = 0;
#ifdef YP
_pw_stepping_yp = 0;
#endif
_pw_stayopen = stayopen;
return(1);
}
int
setpwent()
{
_pw_keynum = 0;
#ifdef YP
_pw_stepping_yp = 0;
#endif
_pw_stayopen = 0;
return(1);
}
void
endpwent()
{
_pw_keynum = 0;
#ifdef YP
_pw_stepping_yp = 0;
#endif
if (_pw_db) {
(void)(_pw_db->close)(_pw_db);
_pw_db = (DB *)NULL;
}
#ifdef YP
if (_ypcache) {
(void)(_ypcache->close)(_ypcache);
_ypcache = (DB *)NULL;
_yp_exclusions = 0;
}
#endif
}
static int
__initdb()
{
static int warned;
char *p;
p = (geteuid()) ? _PATH_MP_DB : _PATH_SMP_DB;
_pw_db = dbopen(p, O_RDONLY, 0, DB_HASH, NULL);
if (_pw_db) {
#ifdef YP
DBT key, data;
char buf[] = { _PW_KEYYPENABLED };
key.data = buf;
key.size = 1;
if ((_pw_db->get)(_pw_db, &key, &data, 0)) {
_yp_enabled = 0;
} else {
_yp_enabled = (int)*((char *)data.data) - 2;
/* Don't even bother with this if we aren't root. */
if (!geteuid()) {
if (!_pw_yp_domain)
if (yp_get_default_domain(&_pw_yp_domain))
return(1);
_gotmaster = _havemaster(_pw_yp_domain);
} else _gotmaster = YP_HAVE_NONE;
if (!_ypcache)
_ypinitdb();
}
#endif
return(1);
}
if (!warned++)
syslog(LOG_ERR, "%s: %m", p);
return(0);
}
static int
__hashpw(key)
DBT *key;
{
register char *p, *t;
static u_int max;
static char *line;
DBT data;
if ((_pw_db->get)(_pw_db, key, &data, 0))
return(0);
p = (char *)data.data;
/* Increase buffer size for long lines if necessary. */
if (data.size > max) {
max = data.size + 1024;
if (!(line = realloc(line, max)))
return(0);
}
/* THIS CODE MUST MATCH THAT IN pwd_mkdb. */
t = line;
#define EXPAND(e) e = t; while ( (*t++ = *p++) );
#define SCALAR(v) memmove(&(v), p, sizeof v); p += sizeof v
EXPAND(_pw_passwd.pw_name);
EXPAND(_pw_passwd.pw_passwd);
SCALAR(_pw_passwd.pw_uid);
SCALAR(_pw_passwd.pw_gid);
SCALAR(_pw_passwd.pw_change);
EXPAND(_pw_passwd.pw_class);
EXPAND(_pw_passwd.pw_gecos);
EXPAND(_pw_passwd.pw_dir);
EXPAND(_pw_passwd.pw_shell);
SCALAR(_pw_passwd.pw_expire);
bcopy(p, (char *)&_pw_passwd.pw_fields, sizeof _pw_passwd.pw_fields);
p += sizeof _pw_passwd.pw_fields;
return(1);
}
#ifdef YP
/*
* Create a DB hash database in memory. Bet you didn't know you
* could do a dbopen() will a NULL filename, did you.
*/
static inline void _ypinitdb()
{
if (_ypcache == (DB *)NULL)
_ypcache = dbopen(NULL, O_RDWR, 600, DB_HASH, NULL);
return;
}
/*
* See if a user is in the blackballed list.
*/
static inline int lookup(name)
char *name;
{
DBT key;
if (!_yp_exclusions)
return(0);
key.data = name;
key.size = strlen(name);
if ((_ypcache->get)(_ypcache, &key, &empty, 0)) {
return(0);
}
return(1);
}
/*
* Store a blackballed user in an in-core hash database.
*/
static inline void store(key)
char *key;
{
DBT lkey;
/*
if (lookup(key))
return;
*/
_yp_exclusions = 1;
lkey.data = key;
lkey.size = strlen(key);
(void)(_ypcache->put)(_ypcache, &lkey, &empty, R_NOOVERWRITE);
}
/*
* Parse the + entries in the password database and do appropriate
* NIS lookups. While ugly to look at, this is optimized to do only
* as many lookups as are absolutely necessary in any given case.
* Basically, the getpwent() function will feed us + and - lines
* as they appear in the database. For + lines, we do netgroup/group
* and user lookups to find all usernames that match the rule and
* extract them from the NIS passwd maps. For - lines, we save the
* matching names in a database and a) exlude them, and b) make sure
* we don't consider them when processing other + lines that appear
* later.
*/
static inline int unwind(grp)
char *grp;
{
char *user, *host, *domain;
static int latch = 0;
static struct group *gr = NULL;
int rv = 0;
if (grp[0] == '+') {
if (strlen(grp) == 1) {
return(_nextyppass(&_pw_passwd));
}
if (grp[1] == '@') {
_pw_stepping_yp = 1;
grpagain:
if (gr != NULL) {
if (*gr->gr_mem != NULL) {
if (lookup(*gr->gr_mem)) {
gr->gr_mem++;
goto grpagain;
}
rv = _getyppass(&_pw_passwd,
*gr->gr_mem,
"passwd.byname");
gr->gr_mem++;
return(rv);
} else {
endgrent();
latch = 0;
gr = NULL;
return(0);
}
}
if (!latch) {
setnetgrent(grp+2);
latch++;
}
again:
if (getnetgrent(&host, &user, &domain) == 0) {
if ((gr = getgrnam(grp+2)) != NULL)
goto grpagain;
latch = 0;
_pw_stepping_yp = 0;
return(0);
} else {
if (lookup(user))
goto again;
if (_getyppass(&_pw_passwd, user,
"passwd.byname"))
return(1);
else
goto again;
}
} else {
if (lookup(grp+1))
return(0);
return(_getyppass(&_pw_passwd, grp+1, "passwd.byname"));
}
} else {
if (grp[1] == '@') {
setnetgrent(grp+2);
rv = 0;
while(getnetgrent(&host, &user, &domain) != 0) {
store(user);
rv++;
}
if (!rv && (gr = getgrnam(grp+2)) != NULL) {
while(gr->gr_mem) {
store(gr->gr_mem);
gr->gr_mem++;
}
}
} else {
store(grp+1);
}
}
return(0);
}
/*
* See if a user is a member of a particular group.
*/
static inline int ingr(grp, name)
char *grp;
char *name;
{
register struct group *gr;
if ((gr = getgrnam(grp)) == NULL)
return(0);
while(*gr->gr_mem) {
if (!strcmp(*gr->gr_mem, name)) {
endgrent();
return(1);
}
gr->gr_mem++;
}
endgrent();
return(0);
}
/*
* Check a user against the +@netgroup/-@netgroup lines listed in
* the local password database. Also checks +user/-user lines.
* If no netgroup exists that matches +@netgroup/-@netgroup,
* try searching regular groups with the same name.
*/
static inline int verf(name)
char *name;
{
DBT key;
char bf[sizeof(_pw_keynum) + 1];
int keynum = 0;
again:
++keynum;
bf[0] = _PW_KEYYPBYNUM;
bcopy((char *)&keynum, bf + 1, sizeof(keynum));
key.data = (u_char *)bf;
key.size = sizeof(keynum) + 1;
if (!__hashpw(&key)) {
/* Try again using old format */
bf[0] = _PW_KEYBYNUM;
bcopy((char *)&keynum, bf + 1, sizeof(keynum));
key.data = (u_char *)bf;
if (!__hashpw(&key))
return(0);
}
if (_pw_passwd.pw_name[0] != '+' && (_pw_passwd.pw_name[0] != '-'))
goto again;
if (_pw_passwd.pw_name[0] == '+') {
if (strlen(_pw_passwd.pw_name) == 1) /* Wildcard */
return(1);
if (_pw_passwd.pw_name[1] == '@') {
if ((innetgr(_pw_passwd.pw_name+2, NULL, name,
_pw_yp_domain) ||
ingr(_pw_passwd.pw_name+2, name)) && !lookup(name))
return(1);
else
goto again;
} else {
if (!strcmp(name, _pw_passwd.pw_name+1) &&
!lookup(name))
return(1);
else
goto again;
}
}
if (_pw_passwd.pw_name[0] == '-') {
/* Note that a minus wildcard is a no-op. */
if (_pw_passwd.pw_name[1] == '@') {
if (innetgr(_pw_passwd.pw_name+2, NULL, name,
_pw_yp_domain) ||
ingr(_pw_passwd.pw_name+2, name)) {
store(name);
return(0);
} else
goto again;
} else {
if (!strcmp(name, _pw_passwd.pw_name+1)) {
store(name);
return(0);
} else
goto again;
}
}
return(0);
}
static char * _get_adjunct_pw(name)
char *name;
{
static char adjunctbuf[YPMAXRECORD+2];
int rval;
char *result;
int resultlen;
char *map = "passwd.adjunct.byname";
char *s;
if ((rval = yp_match(_pw_yp_domain, map, name, strlen(name),
&result, &resultlen)))
return(NULL);
strncpy(adjunctbuf, result, resultlen);
adjunctbuf[resultlen] = '\0';
free(result);
result = (char *)&adjunctbuf;
/* Don't care about the name. */
if ((s = strsep(&result, ":")) == NULL)
return (NULL); /* name */
if ((s = strsep(&result, ":")) == NULL)
return (NULL); /* password */
return(s);
}
static int
_pw_breakout_yp(struct passwd *pw, char *res, int resultlen, int master)
{
char *s, *result;
static char resbuf[YPMAXRECORD+2];
/*
* Be triple, ultra super-duper paranoid: reject entries
* that start with a + or -. yp_mkdb and /var/yp/Makefile
* are _both_ supposed to strip these out, but you never
* know.
*/
if (*res == '+' || *res == '-')
return 0;
/*
* The NIS protocol definition limits the size of an NIS
* record to YPMAXRECORD bytes. We need to do a copy to
* a static buffer here since the memory pointed to by
* res will be free()ed when this function returns.
*/
strncpy((char *)&resbuf, res, resultlen);
resbuf[resultlen] = '\0';
result = (char *)&resbuf;
/*
* XXX Sanity check: make sure all fields are valid (no NULLs).
* If we find a badly formatted entry, we punt.
*/
if ((s = strsep(&result, ":")) == NULL) return 0; /* name */
/*
* We don't care what pw_fields says: we _always_ want the
* username returned to us by NIS.
*/
pw->pw_name = s;
pw->pw_fields |= _PWF_NAME;
if ((s = strsep(&result, ":")) == NULL) return 0; /* password */
if(!(pw->pw_fields & _PWF_PASSWD)) {
/* SunOS passwd.adjunct hack */
if (master == YP_HAVE_ADJUNCT && strstr(s, "##") != NULL) {
char *realpw;
realpw = _get_adjunct_pw(pw->pw_name);
if (realpw == NULL)
pw->pw_passwd = s;
else
pw->pw_passwd = realpw;
} else {
pw->pw_passwd = s;
}
pw->pw_fields |= _PWF_PASSWD;
}
if ((s = strsep(&result, ":")) == NULL) return 0; /* uid */
if(!(pw->pw_fields & _PWF_UID)) {
pw->pw_uid = atoi(s);
pw->pw_fields |= _PWF_UID;
}
if ((s = strsep(&result, ":")) == NULL) return 0; /* gid */
if(!(pw->pw_fields & _PWF_GID)) {
pw->pw_gid = atoi(s);
pw->pw_fields |= _PWF_GID;
}
if (master == YP_HAVE_MASTER) {
if ((s = strsep(&result, ":")) == NULL) return 0; /* class */
if(!(pw->pw_fields & _PWF_CLASS)) {
pw->pw_class = s;
pw->pw_fields |= _PWF_CLASS;
}
if ((s = strsep(&result, ":")) == NULL) return 0; /* change */
if(!(pw->pw_fields & _PWF_CHANGE)) {
pw->pw_change = atol(s);
pw->pw_fields |= _PWF_CHANGE;
}
if ((s = strsep(&result, ":")) == NULL) return 0; /* expire */
if(!(pw->pw_fields & _PWF_EXPIRE)) {
pw->pw_expire = atol(s);
pw->pw_fields |= _PWF_EXPIRE;
}
}
if ((s = strsep(&result, ":")) == NULL) return 0; /* gecos */
if(!(pw->pw_fields & _PWF_GECOS)) {
pw->pw_gecos = s;
pw->pw_fields |= _PWF_GECOS;
}
if ((s = strsep(&result, ":")) == NULL) return 0; /* dir */
if(!(pw->pw_fields & _PWF_DIR)) {
pw->pw_dir = s;
pw->pw_fields |= _PWF_DIR;
}
if ((s = strsep(&result, ":")) == NULL) return 0; /* shell */
if(!(pw->pw_fields & _PWF_SHELL)) {
pw->pw_shell = s;
pw->pw_fields |= _PWF_SHELL;
}
/* Be consistent. */
if ((s = strchr(pw->pw_shell, '\n'))) *s = '\0';
return 1;
}
static int
_havemaster(char *_yp_domain)
{
int order;
int rval;
if (!(rval = yp_order(_yp_domain, "master.passwd.byname", &order)))
return(YP_HAVE_MASTER);
/*
* NIS+ in YP compat mode doesn't support
* YPPROC_ORDER -- no point in continuing.
*/
if (rval == YPERR_YPERR)
return(YP_HAVE_NONE);
/* master.passwd doesn't exist -- try passwd.adjunct */
if (rval == YPERR_MAP) {
rval = yp_order(_yp_domain, "passwd.adjunct.byname", &order);
if (!rval)
return(YP_HAVE_ADJUNCT);
}
return (YP_HAVE_NONE);
}
static int
_getyppass(struct passwd *pw, const char *name, const char *map)
{
char *result, *s;
int resultlen;
int rv;
char mastermap[YPMAXRECORD];
if(!_pw_yp_domain) {
if(yp_get_default_domain(&_pw_yp_domain))
return 0;
}
sprintf(mastermap,"%s",map);
if (_gotmaster == YP_HAVE_MASTER)
sprintf(mastermap,"master.%s", map);
if(yp_match(_pw_yp_domain, (char *)&mastermap, name, strlen(name),
&result, &resultlen))
return 0;
if (!_pw_stepping_yp) {
s = strchr(result, ':');
if (s) {
*s = '\0';
} else {
/* Must be a malformed entry if no colons. */
free(result);
return(0);
}
if (!verf(result)) {
*s = ':';
free(result);
return(0);
}
*s = ':'; /* Put back the colon we previously replaced with a NUL. */
}
rv = _pw_breakout_yp(pw, result, resultlen, _gotmaster);
free(result);
return(rv);
}
static int
_nextyppass(struct passwd *pw)
{
static char *key;
static int keylen;
char *lastkey, *result, *s;
int resultlen;
int rv;
char *map = "passwd.byname";
if(!_pw_yp_domain) {
if(yp_get_default_domain(&_pw_yp_domain))
return 0;
}
if (_gotmaster == YP_HAVE_MASTER)
map = "master.passwd.byname";
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;
}
s = strchr(result, ':');
if (s) {
*s = '\0';
} else {
/* Must be a malformed entry if no colons. */
free(result);
goto tryagain;
}
if (lookup(result)) {
*s = ':';
free(result);
goto tryagain;
}
*s = ':'; /* Put back the colon we previously replaced with a NUL. */
if (_pw_breakout_yp(pw, result, resultlen, _gotmaster)) {
free(result);
return(1);
} else {
free(result);
goto tryagain;
}
}
}
#endif /* YP */