xref: /freebsd/lib/libc/gen/getpwent.c (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
1 /*
2  * Copyright (c) 1988, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)getpwent.c	8.1 (Berkeley) 6/4/93";
36 #endif /* LIBC_SCCS and not lint */
37 
38 #include <sys/param.h>
39 #include <fcntl.h>
40 #include <db.h>
41 #include <syslog.h>
42 #include <pwd.h>
43 #include <utmp.h>
44 #include <errno.h>
45 #include <unistd.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <limits.h>
49 
50 static struct passwd _pw_passwd;	/* password structure */
51 static DB *_pw_db;			/* password database */
52 static int _pw_keynum;			/* key counter */
53 static int _pw_stayopen;		/* keep fd's open */
54 #ifdef YP
55 static struct passwd _pw_copy;
56 static int _yp_enabled;			/* set true when yp enabled */
57 static int _pw_stepping_yp;		/* set true when stepping thru map */
58 #endif
59 static int __hashpw(), __initdb();
60 
61 static int _havemaster(const char *);
62 static int _getyppass(struct passwd *, const char *, const char *);
63 static int _nextyppass(struct passwd *);
64 
65 struct passwd *
66 getpwent()
67 {
68 	DBT key;
69 	char bf[sizeof(_pw_keynum) + 1];
70 	int rv;
71 
72 	if (!_pw_db && !__initdb())
73 		return((struct passwd *)NULL);
74 
75 #ifdef YP
76 	if(_pw_stepping_yp) {
77 		_pw_passwd = _pw_copy;
78 		return (_nextyppass(&_pw_passwd) ? &_pw_passwd : 0);
79 	}
80 #endif
81 
82 tryagain:
83 	++_pw_keynum;
84 	bf[0] = _PW_KEYBYNUM;
85 	bcopy((char *)&_pw_keynum, bf + 1, sizeof(_pw_keynum));
86 	key.data = (u_char *)bf;
87 	key.size = sizeof(_pw_keynum) + 1;
88 	rv = __hashpw(&key);
89 	if(!rv) return (struct passwd *)NULL;
90 #ifdef YP
91 	if(_pw_passwd.pw_name[0] == '+' && _pw_passwd.pw_name[1]) {
92 		_getyppass(&_pw_passwd, &_pw_passwd.pw_name[1],
93 			   "passwd.byname");
94 	} else if(_pw_passwd.pw_name[0] == '+') {
95 		_pw_copy = _pw_passwd;
96 		return (_nextyppass(&_pw_passwd) ? &_pw_passwd : 0);
97 	}
98 #else
99 	/* Ignore YP password file entries when YP is disabled. */
100 	if(_pw_passwd.pw_name[0] == '+') {
101 		goto tryagain;
102 	}
103 #endif
104 	return(&_pw_passwd);
105 }
106 
107 struct passwd *
108 getpwnam(name)
109 	const char *name;
110 {
111 	DBT key;
112 	int len, rval;
113 	char bf[UT_NAMESIZE + 2];
114 
115 	if (!_pw_db && !__initdb())
116 		return((struct passwd *)NULL);
117 
118 	bf[0] = _PW_KEYBYNAME;
119 	len = strlen(name);
120 	bcopy(name, bf + 1, MIN(len, UT_NAMESIZE));
121 	key.data = (u_char *)bf;
122 	key.size = len + 1;
123 	rval = __hashpw(&key);
124 
125 #ifdef YP
126 	if (!rval && _yp_enabled) {
127 		bf[1] = '+';
128 		bcopy(name, bf + 2, MIN(len, UT_NAMESIZE - 1));
129 		key.data = (u_char *)bf;
130 		key.size = len + 2;
131 		rval = __hashpw(&key);
132 		if (!rval && _yp_enabled < 0) {
133 			key.size = 2;
134 			rval = __hashpw(&key);
135 		}
136 		if(rval)
137 			rval = _getyppass(&_pw_passwd, name, "passwd.byname");
138 	}
139 #endif
140 	/*
141 	 * Prevent login attempts when YP is not enabled but YP entries
142 	 * are in /etc/master.passwd.
143 	 */
144 	if (rval && _pw_passwd.pw_name[0] == '+') rval = 0;
145 
146 	if (!_pw_stayopen) {
147 		(void)(_pw_db->close)(_pw_db);
148 		_pw_db = (DB *)NULL;
149 	}
150 	return(rval ? &_pw_passwd : (struct passwd *)NULL);
151 }
152 
153 struct passwd *
154 #ifdef __STDC__
155 getpwuid(uid_t uid)
156 #else
157 getpwuid(uid)
158 	int uid;
159 #endif
160 {
161 	DBT key;
162 	int keyuid, rval;
163 	char bf[sizeof(keyuid) + 1];
164 
165 	if (!_pw_db && !__initdb())
166 		return((struct passwd *)NULL);
167 
168 	bf[0] = _PW_KEYBYUID;
169 	keyuid = uid;
170 	bcopy(&keyuid, bf + 1, sizeof(keyuid));
171 	key.data = (u_char *)bf;
172 	key.size = sizeof(keyuid) + 1;
173 	rval = __hashpw(&key);
174 
175 #ifdef YP
176 	if (!rval && _yp_enabled) {
177 		char ypbuf[16];	/* big enough for 32-bit uids and then some */
178 		snprintf(ypbuf, sizeof ypbuf, "%u", (unsigned)uid);
179 		rval = _getyppass(&_pw_passwd, ypbuf, "passwd.byuid");
180 	}
181 #endif
182 	if (!_pw_stayopen) {
183 		(void)(_pw_db->close)(_pw_db);
184 		_pw_db = (DB *)NULL;
185 	}
186 	return(rval ? &_pw_passwd : (struct passwd *)NULL);
187 }
188 
189 int
190 setpassent(stayopen)
191 	int stayopen;
192 {
193 	_pw_keynum = 0;
194 #ifdef YP
195 	_pw_stepping_yp = 0;
196 #endif
197 	_pw_stayopen = stayopen;
198 	return(1);
199 }
200 
201 int
202 setpwent()
203 {
204 	_pw_keynum = 0;
205 #ifdef YP
206 	_pw_stepping_yp = 0;
207 #endif
208 	_pw_stayopen = 0;
209 	return(1);
210 }
211 
212 void
213 endpwent()
214 {
215 	_pw_keynum = 0;
216 #ifdef YP
217 	_pw_stepping_yp = 0;
218 #endif
219 	if (_pw_db) {
220 		(void)(_pw_db->close)(_pw_db);
221 		_pw_db = (DB *)NULL;
222 	}
223 }
224 
225 static
226 __initdb()
227 {
228 	static int warned;
229 	char *p;
230 
231 	p = (geteuid()) ? _PATH_MP_DB : _PATH_SMP_DB;
232 	_pw_db = dbopen(p, O_RDONLY, 0, DB_HASH, NULL);
233 	if (_pw_db) {
234 #ifdef YP
235 		DBT key, data;
236 		char buf[] = { _PW_KEYYPENABLED };
237 		key.data = buf;
238 		key.size = 1;
239 		if ((_pw_db->get)(_pw_db, &key, &data, 0)) {
240 			_yp_enabled = 0;
241 		} else {
242 			/* Distinguish between old and new versions of
243 			   pwd_mkdb. */
244 			if(data.size != 1) {
245 				_yp_enabled = -1;
246 			} else {
247 				_yp_enabled = (int)*((char *)data.data) - 2;
248 			}
249 		}
250 #endif
251 		return(1);
252 	}
253 	if (!warned)
254 		syslog(LOG_ERR, "%s: %m", p);
255 	return(0);
256 }
257 
258 static
259 __hashpw(key)
260 	DBT *key;
261 {
262 	register char *p, *t;
263 	static u_int max;
264 	static char *line;
265 	DBT data;
266 
267 	/*
268 	 * XXX The pw_fields member of _pw_passwd needs to be cleared
269 	 * at some point since __hashpw() can be called several times in
270 	 * a single program. If we leave here after the second invokation
271 	 * with garbage data in pw_fields, it can totally screw up NIS
272 	 * lookups (the pw_breakout_yp function only populates the pw_passwd
273 	 * structure if the pw_fields bits are clear).
274 	 */
275 	if ((_pw_db->get)(_pw_db, key, &data, 0)) {
276 		if (_pw_passwd.pw_fields)
277 			_pw_passwd.pw_fields = 0;
278 		return(0);
279 	}
280 	p = (char *)data.data;
281 	if (data.size > max && !(line = realloc(line, max += 1024))) {
282 		if (_pw_passwd.pw_fields)
283 			_pw_passwd.pw_fields = 0;
284 		return(0);
285 	}
286 
287 	t = line;
288 #define	EXPAND(e)	e = t; while (*t++ = *p++);
289 	EXPAND(_pw_passwd.pw_name);
290 	EXPAND(_pw_passwd.pw_passwd);
291 	bcopy(p, (char *)&_pw_passwd.pw_uid, sizeof(int));
292 	p += sizeof(int);
293 	bcopy(p, (char *)&_pw_passwd.pw_gid, sizeof(int));
294 	p += sizeof(int);
295 	bcopy(p, (char *)&_pw_passwd.pw_change, sizeof(time_t));
296 	p += sizeof(time_t);
297 	EXPAND(_pw_passwd.pw_class);
298 	EXPAND(_pw_passwd.pw_gecos);
299 	EXPAND(_pw_passwd.pw_dir);
300 	EXPAND(_pw_passwd.pw_shell);
301 	bcopy(p, (char *)&_pw_passwd.pw_expire, sizeof(time_t));
302 	p += sizeof(time_t);
303 	bcopy(p, (char *)&_pw_passwd.pw_fields, sizeof _pw_passwd.pw_fields);
304 	p += sizeof _pw_passwd.pw_fields;
305 	return(1);
306 }
307 
308 #ifdef YP
309 static void
310 _pw_breakout_yp(struct passwd *pw, char *result, int master)
311 {
312 	char *s;
313 
314 	s = strsep(&result, ":"); /* name */
315 	if(!(pw->pw_fields & _PWF_NAME) || (pw->pw_name[0] == '+')) {
316 		pw->pw_name = s;
317 		pw->pw_fields |= _PWF_NAME;
318 	}
319 
320 	s = strsep(&result, ":"); /* password */
321 	if(!(pw->pw_fields & _PWF_PASSWD)) {
322 		pw->pw_passwd = s;
323 		pw->pw_fields |= _PWF_PASSWD;
324 	}
325 
326 	s = strsep(&result, ":"); /* uid */
327 	if(!(pw->pw_fields & _PWF_UID)) {
328 		pw->pw_uid = atoi(s);
329 		pw->pw_fields |= _PWF_UID;
330 	}
331 
332 	s = strsep(&result, ":"); /* gid */
333 	if(!(pw->pw_fields & _PWF_GID))  {
334 		pw->pw_gid = atoi(s);
335 		pw->pw_fields |= _PWF_GID;
336 	}
337 
338 	if (master) {
339 		s = strsep(&result, ":"); /* class */
340 		if(!(pw->pw_fields & _PWF_CLASS))  {
341 			pw->pw_class = s;
342 			pw->pw_fields |= _PWF_CLASS;
343 		}
344 
345 		s = strsep(&result, ":"); /* change */
346 		if(!(pw->pw_fields & _PWF_CHANGE))  {
347 			pw->pw_change = atol(s);
348 			pw->pw_fields |= _PWF_CHANGE;
349 		}
350 
351 		s = strsep(&result, ":"); /* expire */
352 		if(!(pw->pw_fields & _PWF_EXPIRE))  {
353 			pw->pw_expire = atol(s);
354 			pw->pw_fields |= _PWF_EXPIRE;
355 		}
356 	}
357 
358 	s = strsep(&result, ":"); /* gecos */
359 	if(!(pw->pw_fields & _PWF_GECOS)) {
360 		pw->pw_gecos = s;
361 		pw->pw_fields |= _PWF_GECOS;
362 	}
363 
364 	s = strsep(&result, ":"); /* dir */
365 	if(!(pw->pw_fields & _PWF_DIR)) {
366 		pw->pw_dir = s;
367 		pw->pw_fields |= _PWF_DIR;
368 	}
369 
370 	s = strsep(&result, ":"); /* shell */
371 	if(!(pw->pw_fields & _PWF_SHELL)) {
372 		pw->pw_shell = s;
373 		pw->pw_fields |= _PWF_SHELL;
374 	}
375 }
376 
377 static char *_pw_yp_domain;
378 
379 static int
380 _havemaster(const char *_pw_yp_domain)
381 {
382 	char *result;
383 	static char *key;
384 	int resultlen;
385 	static int keylen;
386 
387 	if (yp_first(_pw_yp_domain, "master.passwd.byname",
388 		      &key, &keylen, &result, &resultlen))
389 		return 0;
390 
391 	return 1;
392 }
393 
394 static int
395 _getyppass(struct passwd *pw, const char *name, const char *map)
396 {
397 	char *result, *s;
398 	static char resultbuf[1024];
399 	int resultlen;
400 	char mastermap[1024];
401 	int gotmaster = 0;
402 
403 	if(!_pw_yp_domain) {
404 		if(yp_get_default_domain(&_pw_yp_domain))
405 		  return 0;
406 	}
407 
408 	sprintf(mastermap,"%s",map);
409 
410 	/* Don't even bother with this if we aren't root. */
411 	if (!geteuid())
412 		if (_havemaster(_pw_yp_domain)) {
413 			sprintf(mastermap,"master.%s", map);
414 			gotmaster++;
415 		}
416 
417 	if(yp_match(_pw_yp_domain, &mastermap, name, strlen(name),
418 		    &result, &resultlen))
419 		return 0;
420 
421 	s = strchr(result, '\n');
422 	if(s) *s = '\0';
423 
424 	if(resultlen >= sizeof resultbuf) return 0;
425 	strcpy(resultbuf, result);
426 	result = resultbuf;
427 	_pw_breakout_yp(pw, resultbuf, gotmaster);
428 
429 	return 1;
430 }
431 
432 static int
433 _nextyppass(struct passwd *pw)
434 {
435 	static char *key;
436 	static int keylen;
437 	char *lastkey, *result;
438 	static char resultbuf[1024];
439 	int resultlen;
440 	int rv;
441 	char *map = "passwd.byname";
442 	int gotmaster = 0;
443 
444 	if(!_pw_yp_domain) {
445 		if(yp_get_default_domain(&_pw_yp_domain))
446 		  return 0;
447 	}
448 
449 	/* Don't even bother with this if we aren't root. */
450 	if (!geteuid())
451 		if(_havemaster(_pw_yp_domain)) {
452 			map = "master.passwd.byname";
453 			gotmaster++;
454 		}
455 
456 	if(!_pw_stepping_yp) {
457 		if(key) free(key);
458 			rv = yp_first(_pw_yp_domain, map,
459 				      &key, &keylen, &result, &resultlen);
460 		if(rv) {
461 			return 0;
462 		}
463 		_pw_stepping_yp = 1;
464 		goto unpack;
465 	} else {
466 tryagain:
467 		lastkey = key;
468 			rv = yp_next(_pw_yp_domain, map, key, keylen,
469 			     &key, &keylen, &result, &resultlen);
470 		free(lastkey);
471 unpack:
472 		if(rv) {
473 			_pw_stepping_yp = 0;
474 			return 0;
475 		}
476 
477 		if(resultlen > sizeof(resultbuf)) {
478 			free(result);
479 			goto tryagain;
480 		}
481 
482 		strcpy(resultbuf, result);
483 		free(result);
484 		if(result = strchr(resultbuf, '\n')) *result = '\0';
485 		_pw_breakout_yp(pw, resultbuf, gotmaster);
486 	}
487 	return 1;
488 }
489 
490 #endif /* YP */
491