1 /* $NetBSD: pwcache.c,v 1.31 2010/03/23 20:28:59 drochner Exp $ */
2
3 /*-
4 * Copyright (c) 1992 Keith Muller.
5 * Copyright (c) 1992, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Keith Muller of the University of California, San Diego.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 /*-
37 * Copyright (c) 2002 The NetBSD Foundation, Inc.
38 * All rights reserved.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 * notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 * notice, this list of conditions and the following disclaimer in the
47 * documentation and/or other materials provided with the distribution.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
50 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
51 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
52 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
53 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
54 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
55 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
56 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
57 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
58 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
59 * POSSIBILITY OF SUCH DAMAGE.
60 */
61
62 #if HAVE_NBTOOL_CONFIG_H
63 #include "nbtool_config.h"
64 /*
65 * XXX Undefine the renames of these functions so that we don't
66 * XXX rename the versions found in the host's <pwd.h> by mistake!
67 */
68 #undef group_from_gid
69 #undef user_from_uid
70 #endif
71
72 #include <sys/cdefs.h>
73 #if defined(LIBC_SCCS) && !defined(lint)
74 #if 0
75 static char sccsid[] = "@(#)cache.c 8.1 (Berkeley) 5/31/93";
76 #else
77 __RCSID("$NetBSD: pwcache.c,v 1.31 2010/03/23 20:28:59 drochner Exp $");
78 #endif
79 #endif /* LIBC_SCCS and not lint */
80 __FBSDID("$FreeBSD$");
81
82 #include "namespace.h"
83
84 #include <sys/types.h>
85 #include <sys/param.h>
86
87 #include <assert.h>
88 #include <grp.h>
89 #include <pwd.h>
90 #include <stdio.h>
91 #include <stdlib.h>
92 #include <string.h>
93 #include <unistd.h>
94
95 #define _DIAGASSERT(x) assert((x))
96
97 #if HAVE_NBTOOL_CONFIG_H
98 /* XXX Now, re-apply the renaming that we undid above. */
99 #define group_from_gid __nbcompat_group_from_gid
100 #define user_from_uid __nbcompat_user_from_uid
101 #endif
102
103 #ifdef __weak_alias
104 __weak_alias(user_from_uid,_user_from_uid)
105 __weak_alias(group_from_gid,_group_from_gid)
106 __weak_alias(pwcache_groupdb,_pwcache_groupdb)
107 #endif
108
109 #if !HAVE_PWCACHE_USERDB || HAVE_NBTOOL_CONFIG_H
110 #include "pwcache.h"
111
112 /*
113 * routines that control user, group, uid and gid caches (for the archive
114 * member print routine).
115 * IMPORTANT:
116 * these routines cache BOTH hits and misses, a major performance improvement
117 */
118
119 /*
120 * function pointers to various name lookup routines.
121 * these may be changed as necessary.
122 */
123 static int (*_pwcache_setgroupent)(int) = setgroupent;
124 static void (*_pwcache_endgrent)(void) = endgrent;
125 static struct group * (*_pwcache_getgrnam)(const char *) = getgrnam;
126 static struct group * (*_pwcache_getgrgid)(gid_t) = getgrgid;
127 static int (*_pwcache_setpassent)(int) = setpassent;
128 static void (*_pwcache_endpwent)(void) = endpwent;
129 static struct passwd * (*_pwcache_getpwnam)(const char *) = getpwnam;
130 static struct passwd * (*_pwcache_getpwuid)(uid_t) = getpwuid;
131
132 /*
133 * internal state
134 */
135 static int pwopn; /* is password file open */
136 static int gropn; /* is group file open */
137 static UIDC **uidtb; /* uid to name cache */
138 static GIDC **gidtb; /* gid to name cache */
139 static UIDC **usrtb; /* user name to uid cache */
140 static GIDC **grptb; /* group name to gid cache */
141
142 static int uidtb_fail; /* uidtb_start() failed ? */
143 static int gidtb_fail; /* gidtb_start() failed ? */
144 static int usrtb_fail; /* usrtb_start() failed ? */
145 static int grptb_fail; /* grptb_start() failed ? */
146
147
148 static u_int st_hash(const char *, size_t, int);
149 static int uidtb_start(void);
150 static int gidtb_start(void);
151 static int usrtb_start(void);
152 static int grptb_start(void);
153
154
155 static u_int
st_hash(const char * name,size_t len,int tabsz)156 st_hash(const char *name, size_t len, int tabsz)
157 {
158 u_int key = 0;
159
160 _DIAGASSERT(name != NULL);
161
162 while (len--) {
163 key += *name++;
164 key = (key << 8) | (key >> 24);
165 }
166
167 return (key % tabsz);
168 }
169
170 /*
171 * uidtb_start
172 * creates an an empty uidtb
173 * Return:
174 * 0 if ok, -1 otherwise
175 */
176 static int
uidtb_start(void)177 uidtb_start(void)
178 {
179
180 if (uidtb != NULL)
181 return (0);
182 if (uidtb_fail)
183 return (-1);
184 if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) {
185 ++uidtb_fail;
186 return (-1);
187 }
188 return (0);
189 }
190
191 /*
192 * gidtb_start
193 * creates an an empty gidtb
194 * Return:
195 * 0 if ok, -1 otherwise
196 */
197 static int
gidtb_start(void)198 gidtb_start(void)
199 {
200
201 if (gidtb != NULL)
202 return (0);
203 if (gidtb_fail)
204 return (-1);
205 if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) {
206 ++gidtb_fail;
207 return (-1);
208 }
209 return (0);
210 }
211
212 /*
213 * usrtb_start
214 * creates an an empty usrtb
215 * Return:
216 * 0 if ok, -1 otherwise
217 */
218 static int
usrtb_start(void)219 usrtb_start(void)
220 {
221
222 if (usrtb != NULL)
223 return (0);
224 if (usrtb_fail)
225 return (-1);
226 if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) {
227 ++usrtb_fail;
228 return (-1);
229 }
230 return (0);
231 }
232
233 /*
234 * grptb_start
235 * creates an an empty grptb
236 * Return:
237 * 0 if ok, -1 otherwise
238 */
239 static int
grptb_start(void)240 grptb_start(void)
241 {
242
243 if (grptb != NULL)
244 return (0);
245 if (grptb_fail)
246 return (-1);
247 if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) {
248 ++grptb_fail;
249 return (-1);
250 }
251 return (0);
252 }
253
254 /*
255 * user_from_uid()
256 * caches the name (if any) for the uid. If noname clear, we always
257 * return the stored name (if valid or invalid match).
258 * We use a simple hash table.
259 * Return
260 * Pointer to stored name (or a empty string)
261 */
262 const char *
user_from_uid(uid_t uid,int noname)263 user_from_uid(uid_t uid, int noname)
264 {
265 struct passwd *pw;
266 UIDC *ptr, **pptr;
267
268 if ((uidtb == NULL) && (uidtb_start() < 0))
269 return (NULL);
270
271 /*
272 * see if we have this uid cached
273 */
274 pptr = uidtb + (uid % UID_SZ);
275 ptr = *pptr;
276
277 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) {
278 /*
279 * have an entry for this uid
280 */
281 if (!noname || (ptr->valid == VALID))
282 return (ptr->name);
283 return (NULL);
284 }
285
286 /*
287 * No entry for this uid, we will add it
288 */
289 if (!pwopn) {
290 if (_pwcache_setpassent != NULL)
291 (*_pwcache_setpassent)(1);
292 ++pwopn;
293 }
294
295 if (ptr == NULL)
296 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC));
297
298 if ((pw = (*_pwcache_getpwuid)(uid)) == NULL) {
299 /*
300 * no match for this uid in the local password file
301 * a string that is the uid in numeric format
302 */
303 if (ptr == NULL)
304 return (NULL);
305 ptr->uid = uid;
306 (void)snprintf(ptr->name, UNMLEN, "%lu", (long) uid);
307 ptr->valid = INVALID;
308 if (noname)
309 return (NULL);
310 } else {
311 /*
312 * there is an entry for this uid in the password file
313 */
314 if (ptr == NULL)
315 return (pw->pw_name);
316 ptr->uid = uid;
317 (void)strlcpy(ptr->name, pw->pw_name, UNMLEN);
318 ptr->valid = VALID;
319 }
320 return (ptr->name);
321 }
322
323 /*
324 * group_from_gid()
325 * caches the name (if any) for the gid. If noname clear, we always
326 * return the stored name (if valid or invalid match).
327 * We use a simple hash table.
328 * Return
329 * Pointer to stored name (or a empty string)
330 */
331 const char *
group_from_gid(gid_t gid,int noname)332 group_from_gid(gid_t gid, int noname)
333 {
334 struct group *gr;
335 GIDC *ptr, **pptr;
336
337 if ((gidtb == NULL) && (gidtb_start() < 0))
338 return (NULL);
339
340 /*
341 * see if we have this gid cached
342 */
343 pptr = gidtb + (gid % GID_SZ);
344 ptr = *pptr;
345
346 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) {
347 /*
348 * have an entry for this gid
349 */
350 if (!noname || (ptr->valid == VALID))
351 return (ptr->name);
352 return (NULL);
353 }
354
355 /*
356 * No entry for this gid, we will add it
357 */
358 if (!gropn) {
359 if (_pwcache_setgroupent != NULL)
360 (*_pwcache_setgroupent)(1);
361 ++gropn;
362 }
363
364 if (ptr == NULL)
365 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC));
366
367 if ((gr = (*_pwcache_getgrgid)(gid)) == NULL) {
368 /*
369 * no match for this gid in the local group file, put in
370 * a string that is the gid in numberic format
371 */
372 if (ptr == NULL)
373 return (NULL);
374 ptr->gid = gid;
375 (void)snprintf(ptr->name, GNMLEN, "%lu", (long) gid);
376 ptr->valid = INVALID;
377 if (noname)
378 return (NULL);
379 } else {
380 /*
381 * there is an entry for this group in the group file
382 */
383 if (ptr == NULL)
384 return (gr->gr_name);
385 ptr->gid = gid;
386 (void)strlcpy(ptr->name, gr->gr_name, GNMLEN);
387 ptr->valid = VALID;
388 }
389 return (ptr->name);
390 }
391
392 /*
393 * uid_from_user()
394 * caches the uid for a given user name. We use a simple hash table.
395 * Return
396 * the uid (if any) for a user name, or a -1 if no match can be found
397 */
398 int
uid_from_user(const char * name,uid_t * uid)399 uid_from_user(const char *name, uid_t *uid)
400 {
401 struct passwd *pw;
402 UIDC *ptr, **pptr;
403 size_t namelen;
404
405 /*
406 * return -1 for mangled names
407 */
408 if (name == NULL || ((namelen = strlen(name)) == 0))
409 return (-1);
410 if ((usrtb == NULL) && (usrtb_start() < 0))
411 return (-1);
412
413 /*
414 * look up in hash table, if found and valid return the uid,
415 * if found and invalid, return a -1
416 */
417 pptr = usrtb + st_hash(name, namelen, UNM_SZ);
418 ptr = *pptr;
419
420 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
421 if (ptr->valid == INVALID)
422 return (-1);
423 *uid = ptr->uid;
424 return (0);
425 }
426
427 if (!pwopn) {
428 if (_pwcache_setpassent != NULL)
429 (*_pwcache_setpassent)(1);
430 ++pwopn;
431 }
432
433 if (ptr == NULL)
434 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC));
435
436 /*
437 * no match, look it up, if no match store it as an invalid entry,
438 * or store the matching uid
439 */
440 if (ptr == NULL) {
441 if ((pw = (*_pwcache_getpwnam)(name)) == NULL)
442 return (-1);
443 *uid = pw->pw_uid;
444 return (0);
445 }
446 (void)strlcpy(ptr->name, name, UNMLEN);
447 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) {
448 ptr->valid = INVALID;
449 return (-1);
450 }
451 ptr->valid = VALID;
452 *uid = ptr->uid = pw->pw_uid;
453 return (0);
454 }
455
456 /*
457 * gid_from_group()
458 * caches the gid for a given group name. We use a simple hash table.
459 * Return
460 * the gid (if any) for a group name, or a -1 if no match can be found
461 */
462 int
gid_from_group(const char * name,gid_t * gid)463 gid_from_group(const char *name, gid_t *gid)
464 {
465 struct group *gr;
466 GIDC *ptr, **pptr;
467 size_t namelen;
468
469 /*
470 * return -1 for mangled names
471 */
472 if (name == NULL || ((namelen = strlen(name)) == 0))
473 return (-1);
474 if ((grptb == NULL) && (grptb_start() < 0))
475 return (-1);
476
477 /*
478 * look up in hash table, if found and valid return the uid,
479 * if found and invalid, return a -1
480 */
481 pptr = grptb + st_hash(name, namelen, GID_SZ);
482 ptr = *pptr;
483
484 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
485 if (ptr->valid == INVALID)
486 return (-1);
487 *gid = ptr->gid;
488 return (0);
489 }
490
491 if (!gropn) {
492 if (_pwcache_setgroupent != NULL)
493 (*_pwcache_setgroupent)(1);
494 ++gropn;
495 }
496
497 if (ptr == NULL)
498 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC));
499
500 /*
501 * no match, look it up, if no match store it as an invalid entry,
502 * or store the matching gid
503 */
504 if (ptr == NULL) {
505 if ((gr = (*_pwcache_getgrnam)(name)) == NULL)
506 return (-1);
507 *gid = gr->gr_gid;
508 return (0);
509 }
510
511 (void)strlcpy(ptr->name, name, GNMLEN);
512 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) {
513 ptr->valid = INVALID;
514 return (-1);
515 }
516 ptr->valid = VALID;
517 *gid = ptr->gid = gr->gr_gid;
518 return (0);
519 }
520
521 #define FLUSHTB(arr, len, fail) \
522 do { \
523 if (arr != NULL) { \
524 for (i = 0; i < len; i++) \
525 if (arr[i] != NULL) \
526 free(arr[i]); \
527 arr = NULL; \
528 } \
529 fail = 0; \
530 } while (/* CONSTCOND */0);
531
532 int
pwcache_userdb(int (* a_setpassent)(int),void (* a_endpwent)(void),struct passwd * (* a_getpwnam)(const char *),struct passwd * (* a_getpwuid)(uid_t))533 pwcache_userdb(
534 int (*a_setpassent)(int),
535 void (*a_endpwent)(void),
536 struct passwd * (*a_getpwnam)(const char *),
537 struct passwd * (*a_getpwuid)(uid_t))
538 {
539 int i;
540
541 /* a_setpassent and a_endpwent may be NULL */
542 if (a_getpwnam == NULL || a_getpwuid == NULL)
543 return (-1);
544
545 if (_pwcache_endpwent != NULL)
546 (*_pwcache_endpwent)();
547 FLUSHTB(uidtb, UID_SZ, uidtb_fail);
548 FLUSHTB(usrtb, UNM_SZ, usrtb_fail);
549 pwopn = 0;
550 _pwcache_setpassent = a_setpassent;
551 _pwcache_endpwent = a_endpwent;
552 _pwcache_getpwnam = a_getpwnam;
553 _pwcache_getpwuid = a_getpwuid;
554
555 return (0);
556 }
557
558 int
pwcache_groupdb(int (* a_setgroupent)(int),void (* a_endgrent)(void),struct group * (* a_getgrnam)(const char *),struct group * (* a_getgrgid)(gid_t))559 pwcache_groupdb(
560 int (*a_setgroupent)(int),
561 void (*a_endgrent)(void),
562 struct group * (*a_getgrnam)(const char *),
563 struct group * (*a_getgrgid)(gid_t))
564 {
565 int i;
566
567 /* a_setgroupent and a_endgrent may be NULL */
568 if (a_getgrnam == NULL || a_getgrgid == NULL)
569 return (-1);
570
571 if (_pwcache_endgrent != NULL)
572 (*_pwcache_endgrent)();
573 FLUSHTB(gidtb, GID_SZ, gidtb_fail);
574 FLUSHTB(grptb, GNM_SZ, grptb_fail);
575 gropn = 0;
576 _pwcache_setgroupent = a_setgroupent;
577 _pwcache_endgrent = a_endgrent;
578 _pwcache_getgrnam = a_getgrnam;
579 _pwcache_getgrgid = a_getgrgid;
580
581 return (0);
582 }
583
584
585 #ifdef TEST_PWCACHE
586
587 struct passwd *
test_getpwnam(const char * name)588 test_getpwnam(const char *name)
589 {
590 static struct passwd foo;
591
592 memset(&foo, 0, sizeof(foo));
593 if (strcmp(name, "toor") == 0) {
594 foo.pw_uid = 666;
595 return &foo;
596 }
597 return (getpwnam(name));
598 }
599
600 int
main(int argc,char * argv[])601 main(int argc, char *argv[])
602 {
603 uid_t u;
604 int r, i;
605
606 printf("pass 1 (default userdb)\n");
607 for (i = 1; i < argc; i++) {
608 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n",
609 i, pwopn, usrtb_fail, usrtb);
610 r = uid_from_user(argv[i], &u);
611 if (r == -1)
612 printf(" uid_from_user %s: failed\n", argv[i]);
613 else
614 printf(" uid_from_user %s: %d\n", argv[i], u);
615 }
616 printf("pass 1 finish: pwopn %d usrtb_fail %d usrtb %p\n",
617 pwopn, usrtb_fail, usrtb);
618
619 puts("");
620 printf("pass 2 (replacement userdb)\n");
621 printf("pwcache_userdb returned %d\n",
622 pwcache_userdb(setpassent, test_getpwnam, getpwuid));
623 printf("pwopn %d usrtb_fail %d usrtb %p\n", pwopn, usrtb_fail, usrtb);
624
625 for (i = 1; i < argc; i++) {
626 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n",
627 i, pwopn, usrtb_fail, usrtb);
628 u = -1;
629 r = uid_from_user(argv[i], &u);
630 if (r == -1)
631 printf(" uid_from_user %s: failed\n", argv[i]);
632 else
633 printf(" uid_from_user %s: %d\n", argv[i], u);
634 }
635 printf("pass 2 finish: pwopn %d usrtb_fail %d usrtb %p\n",
636 pwopn, usrtb_fail, usrtb);
637
638 puts("");
639 printf("pass 3 (null pointers)\n");
640 printf("pwcache_userdb returned %d\n",
641 pwcache_userdb(NULL, NULL, NULL));
642
643 return (0);
644 }
645 #endif /* TEST_PWCACHE */
646 #endif /* !HAVE_PWCACHE_USERDB */
647