pwcache.c revision 1.18
1 /* $NetBSD: pwcache.c,v 1.18 2002/01/24 04:07:13 lukem 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. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40 /*- 41 * Copyright (c) 2002 The NetBSD Foundation, Inc. 42 * All rights reserved. 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 1. Redistributions of source code must retain the above copyright 48 * notice, this list of conditions and the following disclaimer. 49 * 2. Redistributions in binary form must reproduce the above copyright 50 * notice, this list of conditions and the following disclaimer in the 51 * documentation and/or other materials provided with the distribution. 52 * 3. All advertising materials mentioning features or use of this software 53 * must display the following acknowledgement: 54 * This product includes software developed by the NetBSD 55 * Foundation, Inc. and its contributors. 56 * 4. Neither the name of The NetBSD Foundation nor the names of its 57 * contributors may be used to endorse or promote products derived 58 * from this software without specific prior written permission. 59 * 60 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 61 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 62 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 63 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 64 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 65 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 66 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 67 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 68 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 69 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 70 * POSSIBILITY OF SUCH DAMAGE. 71 */ 72 73 #if HAVE_CONFIG_H 74 #include "config.h" 75 #else 76 #include <sys/cdefs.h> 77 #if defined(LIBC_SCCS) && !defined(lint) 78 #if 0 79 static char sccsid[] = "@(#)cache.c 8.1 (Berkeley) 5/31/93"; 80 #else 81 __RCSID("$NetBSD: pwcache.c,v 1.18 2002/01/24 04:07:13 lukem Exp $"); 82 #endif 83 #endif /* LIBC_SCCS and not lint */ 84 85 #include "namespace.h" 86 87 #include <sys/types.h> 88 #include <sys/param.h> 89 90 #include <assert.h> 91 #include <grp.h> 92 #include <pwd.h> 93 #include <stdio.h> 94 #include <stdlib.h> 95 #include <string.h> 96 #include <unistd.h> 97 98 #endif /* HAVE_CONFIG_H */ 99 100 #if !HAVE_PWCACHE_USERDB 101 #include "pwcache.h" 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_userdb,_pwcache_userdb) 107 __weak_alias(pwcache_groupdb,_pwcache_groupdb) 108 #endif 109 110 /* 111 * routines that control user, group, uid and gid caches (for the archive 112 * member print routine). 113 * IMPORTANT: 114 * these routines cache BOTH hits and misses, a major performance improvement 115 */ 116 117 /* 118 * function pointers to various name lookup routines. 119 * these may be changed as necessary. 120 */ 121 static int (*_pwcache_setgroupent)(int) = setgroupent; 122 static void (*_pwcache_endgrent)(void) = endgrent; 123 static struct group * (*_pwcache_getgrnam)(const char *) = getgrnam; 124 static struct group * (*_pwcache_getgrgid)(gid_t) = getgrgid; 125 static int (*_pwcache_setpassent)(int) = setpassent; 126 static void (*_pwcache_endpwent)(void) = endpwent; 127 static struct passwd * (*_pwcache_getpwnam)(const char *) = getpwnam; 128 static struct passwd * (*_pwcache_getpwuid)(uid_t) = getpwuid; 129 130 /* 131 * internal state 132 */ 133 static int pwopn; /* is password file open */ 134 static int gropn; /* is group file open */ 135 static UIDC **uidtb; /* uid to name cache */ 136 static GIDC **gidtb; /* gid to name cache */ 137 static UIDC **usrtb; /* user name to uid cache */ 138 static GIDC **grptb; /* group name to gid cache */ 139 140 static int uidtb_fail; /* uidtb_start() failed ? */ 141 static int gidtb_fail; /* gidtb_start() failed ? */ 142 static int usrtb_fail; /* usrtb_start() failed ? */ 143 static int grptb_fail; /* grptb_start() failed ? */ 144 145 146 static u_int st_hash(const char *, size_t, int); 147 static int uidtb_start(void); 148 static int gidtb_start(void); 149 static int usrtb_start(void); 150 static int grptb_start(void); 151 152 153 static u_int 154 st_hash(const char *name, size_t len, int tabsz) 155 { 156 u_int key = 0; 157 158 _DIAGASSERT(name != NULL); 159 160 while (len--) { 161 key += *name++; 162 key = (key << 8) | (key >> 24); 163 } 164 165 return (key % tabsz); 166 } 167 168 /* 169 * uidtb_start 170 * creates an an empty uidtb 171 * Return: 172 * 0 if ok, -1 otherwise 173 */ 174 static int 175 uidtb_start(void) 176 { 177 178 if (uidtb != NULL) 179 return (0); 180 if (uidtb_fail) 181 return (-1); 182 if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) { 183 ++uidtb_fail; 184 return (-1); 185 } 186 return (0); 187 } 188 189 /* 190 * gidtb_start 191 * creates an an empty gidtb 192 * Return: 193 * 0 if ok, -1 otherwise 194 */ 195 static int 196 gidtb_start(void) 197 { 198 199 if (gidtb != NULL) 200 return (0); 201 if (gidtb_fail) 202 return (-1); 203 if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) { 204 ++gidtb_fail; 205 return (-1); 206 } 207 return (0); 208 } 209 210 /* 211 * usrtb_start 212 * creates an an empty usrtb 213 * Return: 214 * 0 if ok, -1 otherwise 215 */ 216 static int 217 usrtb_start(void) 218 { 219 220 if (usrtb != NULL) 221 return (0); 222 if (usrtb_fail) 223 return (-1); 224 if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) { 225 ++usrtb_fail; 226 return (-1); 227 } 228 return (0); 229 } 230 231 /* 232 * grptb_start 233 * creates an an empty grptb 234 * Return: 235 * 0 if ok, -1 otherwise 236 */ 237 static int 238 grptb_start(void) 239 { 240 241 if (grptb != NULL) 242 return (0); 243 if (grptb_fail) 244 return (-1); 245 if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) { 246 ++grptb_fail; 247 return (-1); 248 } 249 return (0); 250 } 251 252 /* 253 * user_from_uid() 254 * caches the name (if any) for the uid. If noname clear, we always 255 * return the the stored name (if valid or invalid match). 256 * We use a simple hash table. 257 * Return 258 * Pointer to stored name (or a empty string) 259 */ 260 261 const char * 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 numberic 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 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 */ 330 331 const char * 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 */ 398 399 int 400 uid_from_user(const char *name, uid_t *uid) 401 { 402 struct passwd *pw; 403 UIDC *ptr, **pptr; 404 size_t namelen; 405 406 /* 407 * return -1 for mangled names 408 */ 409 if (name == NULL || ((namelen = strlen(name)) == 0)) 410 return (-1); 411 if ((usrtb == NULL) && (usrtb_start() < 0)) 412 return (-1); 413 414 /* 415 * look up in hash table, if found and valid return the uid, 416 * if found and invalid, return a -1 417 */ 418 pptr = usrtb + st_hash(name, namelen, UNM_SZ); 419 ptr = *pptr; 420 421 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 422 if (ptr->valid == INVALID) 423 return (-1); 424 *uid = ptr->uid; 425 return (0); 426 } 427 428 if (!pwopn) { 429 if (_pwcache_setpassent != NULL) 430 (*_pwcache_setpassent)(1); 431 ++pwopn; 432 } 433 434 if (ptr == NULL) 435 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 436 437 /* 438 * no match, look it up, if no match store it as an invalid entry, 439 * or store the matching uid 440 */ 441 if (ptr == NULL) { 442 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) 443 return (-1); 444 *uid = pw->pw_uid; 445 return (0); 446 } 447 (void)strlcpy(ptr->name, name, UNMLEN); 448 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) { 449 ptr->valid = INVALID; 450 return (-1); 451 } 452 ptr->valid = VALID; 453 *uid = ptr->uid = pw->pw_uid; 454 return (0); 455 } 456 457 /* 458 * gid_from_group() 459 * caches the gid for a given group name. We use a simple hash table. 460 * Return 461 * the gid (if any) for a group name, or a -1 if no match can be found 462 */ 463 464 int 465 gid_from_group(const char *name, gid_t *gid) 466 { 467 struct group *gr; 468 GIDC *ptr, **pptr; 469 size_t namelen; 470 471 /* 472 * return -1 for mangled names 473 */ 474 if (name == NULL || ((namelen = strlen(name)) == 0)) 475 return (-1); 476 if ((grptb == NULL) && (grptb_start() < 0)) 477 return (-1); 478 479 /* 480 * look up in hash table, if found and valid return the uid, 481 * if found and invalid, return a -1 482 */ 483 pptr = grptb + st_hash(name, namelen, GID_SZ); 484 ptr = *pptr; 485 486 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 487 if (ptr->valid == INVALID) 488 return (-1); 489 *gid = ptr->gid; 490 return (0); 491 } 492 493 if (!gropn) { 494 if (_pwcache_setgroupent != NULL) 495 (*_pwcache_setgroupent)(1); 496 ++gropn; 497 } 498 499 if (ptr == NULL) 500 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 501 502 /* 503 * no match, look it up, if no match store it as an invalid entry, 504 * or store the matching gid 505 */ 506 if (ptr == NULL) { 507 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) 508 return (-1); 509 *gid = gr->gr_gid; 510 return (0); 511 } 512 513 (void)strlcpy(ptr->name, name, GNMLEN); 514 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) { 515 ptr->valid = INVALID; 516 return (-1); 517 } 518 ptr->valid = VALID; 519 *gid = ptr->gid = gr->gr_gid; 520 return (0); 521 } 522 523 #define FLUSHTB(arr, len, fail) \ 524 do { \ 525 if (arr != NULL) { \ 526 for (i = 0; i < len; i++) \ 527 if (arr[i] != NULL) \ 528 free(arr[i]); \ 529 arr = NULL; \ 530 } \ 531 fail = 0; \ 532 } while (/* CONSTCOND */0); 533 534 int 535 pwcache_userdb( 536 int (*a_setpassent)(int), 537 void (*a_endpwent)(void), 538 struct passwd * (*a_getpwnam)(const char *), 539 struct passwd * (*a_getpwuid)(uid_t)) 540 { 541 int i; 542 543 /* a_setpassent and a_endpwent may be NULL */ 544 if (a_getpwnam == NULL || a_getpwuid == NULL) 545 return (-1); 546 547 if (_pwcache_endpwent != NULL) 548 (*_pwcache_endpwent)(); 549 FLUSHTB(uidtb, UID_SZ, uidtb_fail); 550 FLUSHTB(usrtb, UNM_SZ, usrtb_fail); 551 pwopn = 0; 552 _pwcache_setpassent = a_setpassent; 553 _pwcache_endpwent = a_endpwent; 554 _pwcache_getpwnam = a_getpwnam; 555 _pwcache_getpwuid = a_getpwuid; 556 557 return (0); 558 } 559 560 int 561 pwcache_groupdb( 562 int (*a_setgroupent)(int), 563 void (*a_endgrent)(void), 564 struct group * (*a_getgrnam)(const char *), 565 struct group * (*a_getgrgid)(gid_t)) 566 { 567 int i; 568 569 /* a_setgroupent and a_endgrent may be NULL */ 570 if (a_getgrnam == NULL || a_getgrgid == NULL) 571 return (-1); 572 573 if (_pwcache_endgrent != NULL) 574 (*_pwcache_endgrent)(); 575 FLUSHTB(gidtb, GID_SZ, gidtb_fail); 576 FLUSHTB(grptb, GNM_SZ, grptb_fail); 577 gropn = 0; 578 _pwcache_setgroupent = a_setgroupent; 579 _pwcache_endgrent = a_endgrent; 580 _pwcache_getgrnam = a_getgrnam; 581 _pwcache_getgrgid = a_getgrgid; 582 583 return (0); 584 } 585 586 587 #ifdef TEST_PWCACHE 588 589 struct passwd * 590 test_getpwnam(const char *name) 591 { 592 static struct passwd foo; 593 594 memset(&foo, 0, sizeof(foo)); 595 if (strcmp(name, "toor") == 0) { 596 foo.pw_uid = 666; 597 return &foo; 598 } 599 return (getpwnam(name)); 600 } 601 602 int 603 main(int argc, char *argv[]) 604 { 605 uid_t u; 606 int r, i; 607 608 printf("pass 1 (default userdb)\n"); 609 for (i = 1; i < argc; i++) { 610 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 611 i, pwopn, usrtb_fail, usrtb); 612 r = uid_from_user(argv[i], &u); 613 if (r == -1) 614 printf(" uid_from_user %s: failed\n", argv[i]); 615 else 616 printf(" uid_from_user %s: %d\n", argv[i], u); 617 } 618 printf("pass 1 finish: pwopn %d usrtb_fail %d usrtb %p\n", 619 pwopn, usrtb_fail, usrtb); 620 621 puts(""); 622 printf("pass 2 (replacement userdb)\n"); 623 printf("pwcache_userdb returned %d\n", 624 pwcache_userdb(setpassent, test_getpwnam, getpwuid)); 625 printf("pwopn %d usrtb_fail %d usrtb %p\n", pwopn, usrtb_fail, usrtb); 626 627 for (i = 1; i < argc; i++) { 628 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 629 i, pwopn, usrtb_fail, usrtb); 630 u = -1; 631 r = uid_from_user(argv[i], &u); 632 if (r == -1) 633 printf(" uid_from_user %s: failed\n", argv[i]); 634 else 635 printf(" uid_from_user %s: %d\n", argv[i], u); 636 } 637 printf("pass 2 finish: pwopn %d usrtb_fail %d usrtb %p\n", 638 pwopn, usrtb_fail, usrtb); 639 640 puts(""); 641 printf("pass 3 (null pointers)\n"); 642 printf("pwcache_userdb returned %d\n", 643 pwcache_userdb(NULL, NULL, NULL)); 644 645 return (0); 646 } 647 #endif /* TEST_PWCACHE */ 648 #endif /* !HAVE_PWCACHE_USERDB */ 649
Indexes created Sat Sep 27 22:09:54 GMT 2025