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
81 #include "namespace.h"
82
83 #include <sys/types.h>
84 #include <sys/param.h>
85
86 #include <assert.h>
87 #include <grp.h>
88 #include <pwd.h>
89 #include <stdio.h>
90 #include <stdlib.h>
91 #include <string.h>
92 #include <unistd.h>
93
94 #define _DIAGASSERT(x) assert((x))
95
96 #if HAVE_NBTOOL_CONFIG_H
97 /* XXX Now, re-apply the renaming that we undid above. */
98 #define group_from_gid __nbcompat_group_from_gid
99 #define user_from_uid __nbcompat_user_from_uid
100 #endif
101
102 #ifdef __weak_alias
103 __weak_alias(user_from_uid,_user_from_uid)
104 __weak_alias(group_from_gid,_group_from_gid)
105 __weak_alias(pwcache_groupdb,_pwcache_groupdb)
106 #endif
107
108 #if !HAVE_PWCACHE_USERDB || HAVE_NBTOOL_CONFIG_H
109 #include "pwcache.h"
110
111 /*
112 * routines that control user, group, uid and gid caches (for the archive
113 * member print routine).
114 * IMPORTANT:
115 * these routines cache BOTH hits and misses, a major performance improvement
116 */
117
118 /*
119 * function pointers to various name lookup routines.
120 * these may be changed as necessary.
121 */
122 static int (*_pwcache_setgroupent)(int) = setgroupent;
123 static void (*_pwcache_endgrent)(void) = endgrent;
124 static struct group * (*_pwcache_getgrnam)(const char *) = getgrnam;
125 static struct group * (*_pwcache_getgrgid)(gid_t) = getgrgid;
126 static int (*_pwcache_setpassent)(int) = setpassent;
127 static void (*_pwcache_endpwent)(void) = endpwent;
128 static struct passwd * (*_pwcache_getpwnam)(const char *) = getpwnam;
129 static struct passwd * (*_pwcache_getpwuid)(uid_t) = getpwuid;
130
131 /*
132 * internal state
133 */
134 static int pwopn; /* is password file open */
135 static int gropn; /* is group file open */
136 static UIDC **uidtb; /* uid to name cache */
137 static GIDC **gidtb; /* gid to name cache */
138 static UIDC **usrtb; /* user name to uid cache */
139 static GIDC **grptb; /* group name to gid cache */
140
141 static int uidtb_fail; /* uidtb_start() failed ? */
142 static int gidtb_fail; /* gidtb_start() failed ? */
143 static int usrtb_fail; /* usrtb_start() failed ? */
144 static int grptb_fail; /* grptb_start() failed ? */
145
146
147 static u_int st_hash(const char *, size_t, int);
148 static int uidtb_start(void);
149 static int gidtb_start(void);
150 static int usrtb_start(void);
151 static int grptb_start(void);
152
153
154 static u_int
st_hash(const char * name,size_t len,int tabsz)155 st_hash(const char *name, size_t len, int tabsz)
156 {
157 u_int key = 0;
158
159 _DIAGASSERT(name != NULL);
160
161 while (len--) {
162 key += *name++;
163 key = (key << 8) | (key >> 24);
164 }
165
166 return (key % tabsz);
167 }
168
169 /*
170 * uidtb_start
171 * creates an an empty uidtb
172 * Return:
173 * 0 if ok, -1 otherwise
174 */
175 static int
uidtb_start(void)176 uidtb_start(void)
177 {
178
179 if (uidtb != NULL)
180 return (0);
181 if (uidtb_fail)
182 return (-1);
183 if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) {
184 ++uidtb_fail;
185 return (-1);
186 }
187 return (0);
188 }
189
190 /*
191 * gidtb_start
192 * creates an an empty gidtb
193 * Return:
194 * 0 if ok, -1 otherwise
195 */
196 static int
gidtb_start(void)197 gidtb_start(void)
198 {
199
200 if (gidtb != NULL)
201 return (0);
202 if (gidtb_fail)
203 return (-1);
204 if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) {
205 ++gidtb_fail;
206 return (-1);
207 }
208 return (0);
209 }
210
211 /*
212 * usrtb_start
213 * creates an an empty usrtb
214 * Return:
215 * 0 if ok, -1 otherwise
216 */
217 static int
usrtb_start(void)218 usrtb_start(void)
219 {
220
221 if (usrtb != NULL)
222 return (0);
223 if (usrtb_fail)
224 return (-1);
225 if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) {
226 ++usrtb_fail;
227 return (-1);
228 }
229 return (0);
230 }
231
232 /*
233 * grptb_start
234 * creates an an empty grptb
235 * Return:
236 * 0 if ok, -1 otherwise
237 */
238 static int
grptb_start(void)239 grptb_start(void)
240 {
241
242 if (grptb != NULL)
243 return (0);
244 if (grptb_fail)
245 return (-1);
246 if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) {
247 ++grptb_fail;
248 return (-1);
249 }
250 return (0);
251 }
252
253 /*
254 * user_from_uid()
255 * caches the name (if any) for the uid. If noname clear, we always
256 * return the stored name (if valid or invalid match).
257 * We use a simple hash table.
258 * Return
259 * Pointer to stored name (or a empty string)
260 */
261 const char *
user_from_uid(uid_t uid,int noname)262 user_from_uid(uid_t uid, int noname)
263 {
264 struct passwd *pw;
265 UIDC *ptr, **pptr;
266
267 if ((uidtb == NULL) && (uidtb_start() < 0))
268 return (NULL);
269
270 /*
271 * see if we have this uid cached
272 */
273 pptr = uidtb + (uid % UID_SZ);
274 ptr = *pptr;
275
276 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) {
277 /*
278 * have an entry for this uid
279 */
280 if (!noname || (ptr->valid == VALID))
281 return (ptr->name);
282 return (NULL);
283 }
284
285 /*
286 * No entry for this uid, we will add it
287 */
288 if (!pwopn) {
289 if (_pwcache_setpassent != NULL)
290 (*_pwcache_setpassent)(1);
291 ++pwopn;
292 }
293
294 if (ptr == NULL)
295 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC));
296
297 if ((pw = (*_pwcache_getpwuid)(uid)) == NULL) {
298 /*
299 * no match for this uid in the local password file
300 * a string that is the uid in numeric format
301 */
302 if (ptr == NULL)
303 return (NULL);
304 ptr->uid = uid;
305 (void)snprintf(ptr->name, UNMLEN, "%lu", (long) uid);
306 ptr->valid = INVALID;
307 if (noname)
308 return (NULL);
309 } else {
310 /*
311 * there is an entry for this uid in the password file
312 */
313 if (ptr == NULL)
314 return (pw->pw_name);
315 ptr->uid = uid;
316 (void)strlcpy(ptr->name, pw->pw_name, UNMLEN);
317 ptr->valid = VALID;
318 }
319 return (ptr->name);
320 }
321
322 /*
323 * group_from_gid()
324 * caches the name (if any) for the gid. If noname clear, we always
325 * return the stored name (if valid or invalid match).
326 * We use a simple hash table.
327 * Return
328 * Pointer to stored name (or a empty string)
329 */
330 const char *
group_from_gid(gid_t gid,int noname)331 group_from_gid(gid_t gid, int noname)
332 {
333 struct group *gr;
334 GIDC *ptr, **pptr;
335
336 if ((gidtb == NULL) && (gidtb_start() < 0))
337 return (NULL);
338
339 /*
340 * see if we have this gid cached
341 */
342 pptr = gidtb + (gid % GID_SZ);
343 ptr = *pptr;
344
345 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) {
346 /*
347 * have an entry for this gid
348 */
349 if (!noname || (ptr->valid == VALID))
350 return (ptr->name);
351 return (NULL);
352 }
353
354 /*
355 * No entry for this gid, we will add it
356 */
357 if (!gropn) {
358 if (_pwcache_setgroupent != NULL)
359 (*_pwcache_setgroupent)(1);
360 ++gropn;
361 }
362
363 if (ptr == NULL)
364 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC));
365
366 if ((gr = (*_pwcache_getgrgid)(gid)) == NULL) {
367 /*
368 * no match for this gid in the local group file, put in
369 * a string that is the gid in numberic format
370 */
371 if (ptr == NULL)
372 return (NULL);
373 ptr->gid = gid;
374 (void)snprintf(ptr->name, GNMLEN, "%lu", (long) gid);
375 ptr->valid = INVALID;
376 if (noname)
377 return (NULL);
378 } else {
379 /*
380 * there is an entry for this group in the group file
381 */
382 if (ptr == NULL)
383 return (gr->gr_name);
384 ptr->gid = gid;
385 (void)strlcpy(ptr->name, gr->gr_name, GNMLEN);
386 ptr->valid = VALID;
387 }
388 return (ptr->name);
389 }
390
391 /*
392 * uid_from_user()
393 * caches the uid for a given user name. We use a simple hash table.
394 * Return
395 * the uid (if any) for a user name, or a -1 if no match can be found
396 */
397 int
uid_from_user(const char * name,uid_t * uid)398 uid_from_user(const char *name, uid_t *uid)
399 {
400 struct passwd *pw;
401 UIDC *ptr, **pptr;
402 size_t namelen;
403
404 /*
405 * return -1 for mangled names
406 */
407 if (name == NULL || ((namelen = strlen(name)) == 0))
408 return (-1);
409 if ((usrtb == NULL) && (usrtb_start() < 0))
410 return (-1);
411
412 /*
413 * look up in hash table, if found and valid return the uid,
414 * if found and invalid, return a -1
415 */
416 pptr = usrtb + st_hash(name, namelen, UNM_SZ);
417 ptr = *pptr;
418
419 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
420 if (ptr->valid == INVALID)
421 return (-1);
422 *uid = ptr->uid;
423 return (0);
424 }
425
426 if (!pwopn) {
427 if (_pwcache_setpassent != NULL)
428 (*_pwcache_setpassent)(1);
429 ++pwopn;
430 }
431
432 if (ptr == NULL)
433 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC));
434
435 /*
436 * no match, look it up, if no match store it as an invalid entry,
437 * or store the matching uid
438 */
439 if (ptr == NULL) {
440 if ((pw = (*_pwcache_getpwnam)(name)) == NULL)
441 return (-1);
442 *uid = pw->pw_uid;
443 return (0);
444 }
445 (void)strlcpy(ptr->name, name, UNMLEN);
446 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) {
447 ptr->valid = INVALID;
448 return (-1);
449 }
450 ptr->valid = VALID;
451 *uid = ptr->uid = pw->pw_uid;
452 return (0);
453 }
454
455 /*
456 * gid_from_group()
457 * caches the gid for a given group name. We use a simple hash table.
458 * Return
459 * the gid (if any) for a group name, or a -1 if no match can be found
460 */
461 int
gid_from_group(const char * name,gid_t * gid)462 gid_from_group(const char *name, gid_t *gid)
463 {
464 struct group *gr;
465 GIDC *ptr, **pptr;
466 size_t namelen;
467
468 /*
469 * return -1 for mangled names
470 */
471 if (name == NULL || ((namelen = strlen(name)) == 0))
472 return (-1);
473 if ((grptb == NULL) && (grptb_start() < 0))
474 return (-1);
475
476 /*
477 * look up in hash table, if found and valid return the uid,
478 * if found and invalid, return a -1
479 */
480 pptr = grptb + st_hash(name, namelen, GID_SZ);
481 ptr = *pptr;
482
483 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
484 if (ptr->valid == INVALID)
485 return (-1);
486 *gid = ptr->gid;
487 return (0);
488 }
489
490 if (!gropn) {
491 if (_pwcache_setgroupent != NULL)
492 (*_pwcache_setgroupent)(1);
493 ++gropn;
494 }
495
496 if (ptr == NULL)
497 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC));
498
499 /*
500 * no match, look it up, if no match store it as an invalid entry,
501 * or store the matching gid
502 */
503 if (ptr == NULL) {
504 if ((gr = (*_pwcache_getgrnam)(name)) == NULL)
505 return (-1);
506 *gid = gr->gr_gid;
507 return (0);
508 }
509
510 (void)strlcpy(ptr->name, name, GNMLEN);
511 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) {
512 ptr->valid = INVALID;
513 return (-1);
514 }
515 ptr->valid = VALID;
516 *gid = ptr->gid = gr->gr_gid;
517 return (0);
518 }
519
520 #define FLUSHTB(arr, len, fail) \
521 do { \
522 if (arr != NULL) { \
523 for (i = 0; i < len; i++) \
524 if (arr[i] != NULL) \
525 free(arr[i]); \
526 arr = NULL; \
527 } \
528 fail = 0; \
529 } while (/* CONSTCOND */0);
530
531 int
pwcache_userdb(int (* a_setpassent)(int),void (* a_endpwent)(void),struct passwd * (* a_getpwnam)(const char *),struct passwd * (* a_getpwuid)(uid_t))532 pwcache_userdb(
533 int (*a_setpassent)(int),
534 void (*a_endpwent)(void),
535 struct passwd * (*a_getpwnam)(const char *),
536 struct passwd * (*a_getpwuid)(uid_t))
537 {
538 int i;
539
540 /* a_setpassent and a_endpwent may be NULL */
541 if (a_getpwnam == NULL || a_getpwuid == NULL)
542 return (-1);
543
544 if (_pwcache_endpwent != NULL)
545 (*_pwcache_endpwent)();
546 FLUSHTB(uidtb, UID_SZ, uidtb_fail);
547 FLUSHTB(usrtb, UNM_SZ, usrtb_fail);
548 pwopn = 0;
549 _pwcache_setpassent = a_setpassent;
550 _pwcache_endpwent = a_endpwent;
551 _pwcache_getpwnam = a_getpwnam;
552 _pwcache_getpwuid = a_getpwuid;
553
554 return (0);
555 }
556
557 int
pwcache_groupdb(int (* a_setgroupent)(int),void (* a_endgrent)(void),struct group * (* a_getgrnam)(const char *),struct group * (* a_getgrgid)(gid_t))558 pwcache_groupdb(
559 int (*a_setgroupent)(int),
560 void (*a_endgrent)(void),
561 struct group * (*a_getgrnam)(const char *),
562 struct group * (*a_getgrgid)(gid_t))
563 {
564 int i;
565
566 /* a_setgroupent and a_endgrent may be NULL */
567 if (a_getgrnam == NULL || a_getgrgid == NULL)
568 return (-1);
569
570 if (_pwcache_endgrent != NULL)
571 (*_pwcache_endgrent)();
572 FLUSHTB(gidtb, GID_SZ, gidtb_fail);
573 FLUSHTB(grptb, GNM_SZ, grptb_fail);
574 gropn = 0;
575 _pwcache_setgroupent = a_setgroupent;
576 _pwcache_endgrent = a_endgrent;
577 _pwcache_getgrnam = a_getgrnam;
578 _pwcache_getgrgid = a_getgrgid;
579
580 return (0);
581 }
582
583
584 #ifdef TEST_PWCACHE
585
586 struct passwd *
test_getpwnam(const char * name)587 test_getpwnam(const char *name)
588 {
589 static struct passwd foo;
590
591 memset(&foo, 0, sizeof(foo));
592 if (strcmp(name, "toor") == 0) {
593 foo.pw_uid = 666;
594 return &foo;
595 }
596 return (getpwnam(name));
597 }
598
599 int
main(int argc,char * argv[])600 main(int argc, char *argv[])
601 {
602 uid_t u;
603 int r, i;
604
605 printf("pass 1 (default userdb)\n");
606 for (i = 1; i < argc; i++) {
607 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n",
608 i, pwopn, usrtb_fail, usrtb);
609 r = uid_from_user(argv[i], &u);
610 if (r == -1)
611 printf(" uid_from_user %s: failed\n", argv[i]);
612 else
613 printf(" uid_from_user %s: %d\n", argv[i], u);
614 }
615 printf("pass 1 finish: pwopn %d usrtb_fail %d usrtb %p\n",
616 pwopn, usrtb_fail, usrtb);
617
618 puts("");
619 printf("pass 2 (replacement userdb)\n");
620 printf("pwcache_userdb returned %d\n",
621 pwcache_userdb(setpassent, test_getpwnam, getpwuid));
622 printf("pwopn %d usrtb_fail %d usrtb %p\n", pwopn, usrtb_fail, usrtb);
623
624 for (i = 1; i < argc; i++) {
625 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n",
626 i, pwopn, usrtb_fail, usrtb);
627 u = -1;
628 r = uid_from_user(argv[i], &u);
629 if (r == -1)
630 printf(" uid_from_user %s: failed\n", argv[i]);
631 else
632 printf(" uid_from_user %s: %d\n", argv[i], u);
633 }
634 printf("pass 2 finish: pwopn %d usrtb_fail %d usrtb %p\n",
635 pwopn, usrtb_fail, usrtb);
636
637 puts("");
638 printf("pass 3 (null pointers)\n");
639 printf("pwcache_userdb returned %d\n",
640 pwcache_userdb(NULL, NULL, NULL));
641
642 return (0);
643 }
644 #endif /* TEST_PWCACHE */
645 #endif /* !HAVE_PWCACHE_USERDB */
646