pwcache.c revision 1.27
1 /* $NetBSD: pwcache.c,v 1.27 2004/05/18 22:14:35 sjg 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 * 3. All advertising materials mentioning features or use of this software 49 * must display the following acknowledgement: 50 * This product includes software developed by the NetBSD 51 * Foundation, Inc. and its contributors. 52 * 4. Neither the name of The NetBSD Foundation nor the names of its 53 * contributors may be used to endorse or promote products derived 54 * from this software without specific prior written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 57 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 58 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 59 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 60 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 61 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 62 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 63 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 64 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 65 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 66 * POSSIBILITY OF SUCH DAMAGE. 67 */ 68 69 #if HAVE_NBTOOL_CONFIG_H 70 #include "nbtool_config.h" 71 #endif 72 73 #include <sys/cdefs.h> 74 #if defined(LIBC_SCCS) && !defined(lint) 75 #if 0 76 static char sccsid[] = "@(#)cache.c 8.1 (Berkeley) 5/31/93"; 77 #else 78 __RCSID("$NetBSD: pwcache.c,v 1.27 2004/05/18 22:14:35 sjg Exp $"); 79 #endif 80 #endif /* LIBC_SCCS and not lint */ 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 #ifdef __weak_alias 96 __weak_alias(user_from_uid,_user_from_uid) 97 __weak_alias(group_from_gid,_group_from_gid) 98 __weak_alias(pwcache_userdb,_pwcache_userdb) 99 __weak_alias(pwcache_groupdb,_pwcache_groupdb) 100 #endif 101 102 #if !HAVE_PWCACHE_USERDB 103 #include "pwcache.h" 104 105 /* 106 * routines that control user, group, uid and gid caches (for the archive 107 * member print routine). 108 * IMPORTANT: 109 * these routines cache BOTH hits and misses, a major performance improvement 110 */ 111 112 /* 113 * function pointers to various name lookup routines. 114 * these may be changed as necessary. 115 */ 116 static int (*_pwcache_setgroupent)(int) = setgroupent; 117 static void (*_pwcache_endgrent)(void) = endgrent; 118 static struct group * (*_pwcache_getgrnam)(const char *) = getgrnam; 119 static struct group * (*_pwcache_getgrgid)(gid_t) = getgrgid; 120 static int (*_pwcache_setpassent)(int) = setpassent; 121 static void (*_pwcache_endpwent)(void) = endpwent; 122 static struct passwd * (*_pwcache_getpwnam)(const char *) = getpwnam; 123 static struct passwd * (*_pwcache_getpwuid)(uid_t) = getpwuid; 124 125 /* 126 * internal state 127 */ 128 static int pwopn; /* is password file open */ 129 static int gropn; /* is group file open */ 130 static UIDC **uidtb; /* uid to name cache */ 131 static GIDC **gidtb; /* gid to name cache */ 132 static UIDC **usrtb; /* user name to uid cache */ 133 static GIDC **grptb; /* group name to gid cache */ 134 135 static int uidtb_fail; /* uidtb_start() failed ? */ 136 static int gidtb_fail; /* gidtb_start() failed ? */ 137 static int usrtb_fail; /* usrtb_start() failed ? */ 138 static int grptb_fail; /* grptb_start() failed ? */ 139 140 141 static u_int st_hash(const char *, size_t, int); 142 static int uidtb_start(void); 143 static int gidtb_start(void); 144 static int usrtb_start(void); 145 static int grptb_start(void); 146 147 148 static u_int 149 st_hash(const char *name, size_t len, int tabsz) 150 { 151 u_int key = 0; 152 153 _DIAGASSERT(name != NULL); 154 155 while (len--) { 156 key += *name++; 157 key = (key << 8) | (key >> 24); 158 } 159 160 return (key % tabsz); 161 } 162 163 /* 164 * uidtb_start 165 * creates an an empty uidtb 166 * Return: 167 * 0 if ok, -1 otherwise 168 */ 169 static int 170 uidtb_start(void) 171 { 172 173 if (uidtb != NULL) 174 return (0); 175 if (uidtb_fail) 176 return (-1); 177 if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) { 178 ++uidtb_fail; 179 return (-1); 180 } 181 return (0); 182 } 183 184 /* 185 * gidtb_start 186 * creates an an empty gidtb 187 * Return: 188 * 0 if ok, -1 otherwise 189 */ 190 static int 191 gidtb_start(void) 192 { 193 194 if (gidtb != NULL) 195 return (0); 196 if (gidtb_fail) 197 return (-1); 198 if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) { 199 ++gidtb_fail; 200 return (-1); 201 } 202 return (0); 203 } 204 205 /* 206 * usrtb_start 207 * creates an an empty usrtb 208 * Return: 209 * 0 if ok, -1 otherwise 210 */ 211 static int 212 usrtb_start(void) 213 { 214 215 if (usrtb != NULL) 216 return (0); 217 if (usrtb_fail) 218 return (-1); 219 if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) { 220 ++usrtb_fail; 221 return (-1); 222 } 223 return (0); 224 } 225 226 /* 227 * grptb_start 228 * creates an an empty grptb 229 * Return: 230 * 0 if ok, -1 otherwise 231 */ 232 static int 233 grptb_start(void) 234 { 235 236 if (grptb != NULL) 237 return (0); 238 if (grptb_fail) 239 return (-1); 240 if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) { 241 ++grptb_fail; 242 return (-1); 243 } 244 return (0); 245 } 246 247 /* 248 * user_from_uid() 249 * caches the name (if any) for the uid. If noname clear, we always 250 * return the stored name (if valid or invalid match). 251 * We use a simple hash table. 252 * Return 253 * Pointer to stored name (or a empty string) 254 */ 255 const char * 256 user_from_uid(uid_t uid, int noname) 257 { 258 struct passwd *pw; 259 UIDC *ptr, **pptr; 260 261 if ((uidtb == NULL) && (uidtb_start() < 0)) 262 return (NULL); 263 264 /* 265 * see if we have this uid cached 266 */ 267 pptr = uidtb + (uid % UID_SZ); 268 ptr = *pptr; 269 270 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) { 271 /* 272 * have an entry for this uid 273 */ 274 if (!noname || (ptr->valid == VALID)) 275 return (ptr->name); 276 return (NULL); 277 } 278 279 /* 280 * No entry for this uid, we will add it 281 */ 282 if (!pwopn) { 283 if (_pwcache_setpassent != NULL) 284 (*_pwcache_setpassent)(1); 285 ++pwopn; 286 } 287 288 if (ptr == NULL) 289 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 290 291 if ((pw = (*_pwcache_getpwuid)(uid)) == NULL) { 292 /* 293 * no match for this uid in the local password file 294 * a string that is the uid in numeric format 295 */ 296 if (ptr == NULL) 297 return (NULL); 298 ptr->uid = uid; 299 (void)snprintf(ptr->name, UNMLEN, "%lu", (long) uid); 300 ptr->valid = INVALID; 301 if (noname) 302 return (NULL); 303 } else { 304 /* 305 * there is an entry for this uid in the password file 306 */ 307 if (ptr == NULL) 308 return (pw->pw_name); 309 ptr->uid = uid; 310 (void)strlcpy(ptr->name, pw->pw_name, UNMLEN); 311 ptr->valid = VALID; 312 } 313 return (ptr->name); 314 } 315 316 /* 317 * group_from_gid() 318 * caches the name (if any) for the gid. If noname clear, we always 319 * return the stored name (if valid or invalid match). 320 * We use a simple hash table. 321 * Return 322 * Pointer to stored name (or a empty string) 323 */ 324 const char * 325 group_from_gid(gid_t gid, int noname) 326 { 327 struct group *gr; 328 GIDC *ptr, **pptr; 329 330 if ((gidtb == NULL) && (gidtb_start() < 0)) 331 return (NULL); 332 333 /* 334 * see if we have this gid cached 335 */ 336 pptr = gidtb + (gid % GID_SZ); 337 ptr = *pptr; 338 339 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) { 340 /* 341 * have an entry for this gid 342 */ 343 if (!noname || (ptr->valid == VALID)) 344 return (ptr->name); 345 return (NULL); 346 } 347 348 /* 349 * No entry for this gid, we will add it 350 */ 351 if (!gropn) { 352 if (_pwcache_setgroupent != NULL) 353 (*_pwcache_setgroupent)(1); 354 ++gropn; 355 } 356 357 if (ptr == NULL) 358 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 359 360 if ((gr = (*_pwcache_getgrgid)(gid)) == NULL) { 361 /* 362 * no match for this gid in the local group file, put in 363 * a string that is the gid in numberic format 364 */ 365 if (ptr == NULL) 366 return (NULL); 367 ptr->gid = gid; 368 (void)snprintf(ptr->name, GNMLEN, "%lu", (long) gid); 369 ptr->valid = INVALID; 370 if (noname) 371 return (NULL); 372 } else { 373 /* 374 * there is an entry for this group in the group file 375 */ 376 if (ptr == NULL) 377 return (gr->gr_name); 378 ptr->gid = gid; 379 (void)strlcpy(ptr->name, gr->gr_name, GNMLEN); 380 ptr->valid = VALID; 381 } 382 return (ptr->name); 383 } 384 385 /* 386 * uid_from_user() 387 * caches the uid for a given user name. We use a simple hash table. 388 * Return 389 * the uid (if any) for a user name, or a -1 if no match can be found 390 */ 391 int 392 uid_from_user(const char *name, uid_t *uid) 393 { 394 struct passwd *pw; 395 UIDC *ptr, **pptr; 396 size_t namelen; 397 398 /* 399 * return -1 for mangled names 400 */ 401 if (name == NULL || ((namelen = strlen(name)) == 0)) 402 return (-1); 403 if ((usrtb == NULL) && (usrtb_start() < 0)) 404 return (-1); 405 406 /* 407 * look up in hash table, if found and valid return the uid, 408 * if found and invalid, return a -1 409 */ 410 pptr = usrtb + st_hash(name, namelen, UNM_SZ); 411 ptr = *pptr; 412 413 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 414 if (ptr->valid == INVALID) 415 return (-1); 416 *uid = ptr->uid; 417 return (0); 418 } 419 420 if (!pwopn) { 421 if (_pwcache_setpassent != NULL) 422 (*_pwcache_setpassent)(1); 423 ++pwopn; 424 } 425 426 if (ptr == NULL) 427 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 428 429 /* 430 * no match, look it up, if no match store it as an invalid entry, 431 * or store the matching uid 432 */ 433 if (ptr == NULL) { 434 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) 435 return (-1); 436 *uid = pw->pw_uid; 437 return (0); 438 } 439 (void)strlcpy(ptr->name, name, UNMLEN); 440 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) { 441 ptr->valid = INVALID; 442 return (-1); 443 } 444 ptr->valid = VALID; 445 *uid = ptr->uid = pw->pw_uid; 446 return (0); 447 } 448 449 /* 450 * gid_from_group() 451 * caches the gid for a given group name. We use a simple hash table. 452 * Return 453 * the gid (if any) for a group name, or a -1 if no match can be found 454 */ 455 int 456 gid_from_group(const char *name, gid_t *gid) 457 { 458 struct group *gr; 459 GIDC *ptr, **pptr; 460 size_t namelen; 461 462 /* 463 * return -1 for mangled names 464 */ 465 if (name == NULL || ((namelen = strlen(name)) == 0)) 466 return (-1); 467 if ((grptb == NULL) && (grptb_start() < 0)) 468 return (-1); 469 470 /* 471 * look up in hash table, if found and valid return the uid, 472 * if found and invalid, return a -1 473 */ 474 pptr = grptb + st_hash(name, namelen, GID_SZ); 475 ptr = *pptr; 476 477 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 478 if (ptr->valid == INVALID) 479 return (-1); 480 *gid = ptr->gid; 481 return (0); 482 } 483 484 if (!gropn) { 485 if (_pwcache_setgroupent != NULL) 486 (*_pwcache_setgroupent)(1); 487 ++gropn; 488 } 489 490 if (ptr == NULL) 491 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 492 493 /* 494 * no match, look it up, if no match store it as an invalid entry, 495 * or store the matching gid 496 */ 497 if (ptr == NULL) { 498 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) 499 return (-1); 500 *gid = gr->gr_gid; 501 return (0); 502 } 503 504 (void)strlcpy(ptr->name, name, GNMLEN); 505 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) { 506 ptr->valid = INVALID; 507 return (-1); 508 } 509 ptr->valid = VALID; 510 *gid = ptr->gid = gr->gr_gid; 511 return (0); 512 } 513 514 #define FLUSHTB(arr, len, fail) \ 515 do { \ 516 if (arr != NULL) { \ 517 for (i = 0; i < len; i++) \ 518 if (arr[i] != NULL) \ 519 free(arr[i]); \ 520 arr = NULL; \ 521 } \ 522 fail = 0; \ 523 } while (/* CONSTCOND */0); 524 525 int 526 pwcache_userdb( 527 int (*a_setpassent)(int), 528 void (*a_endpwent)(void), 529 struct passwd * (*a_getpwnam)(const char *), 530 struct passwd * (*a_getpwuid)(uid_t)) 531 { 532 int i; 533 534 /* a_setpassent and a_endpwent may be NULL */ 535 if (a_getpwnam == NULL || a_getpwuid == NULL) 536 return (-1); 537 538 if (_pwcache_endpwent != NULL) 539 (*_pwcache_endpwent)(); 540 FLUSHTB(uidtb, UID_SZ, uidtb_fail); 541 FLUSHTB(usrtb, UNM_SZ, usrtb_fail); 542 pwopn = 0; 543 _pwcache_setpassent = a_setpassent; 544 _pwcache_endpwent = a_endpwent; 545 _pwcache_getpwnam = a_getpwnam; 546 _pwcache_getpwuid = a_getpwuid; 547 548 return (0); 549 } 550 551 int 552 pwcache_groupdb( 553 int (*a_setgroupent)(int), 554 void (*a_endgrent)(void), 555 struct group * (*a_getgrnam)(const char *), 556 struct group * (*a_getgrgid)(gid_t)) 557 { 558 int i; 559 560 /* a_setgroupent and a_endgrent may be NULL */ 561 if (a_getgrnam == NULL || a_getgrgid == NULL) 562 return (-1); 563 564 if (_pwcache_endgrent != NULL) 565 (*_pwcache_endgrent)(); 566 FLUSHTB(gidtb, GID_SZ, gidtb_fail); 567 FLUSHTB(grptb, GNM_SZ, grptb_fail); 568 gropn = 0; 569 _pwcache_setgroupent = a_setgroupent; 570 _pwcache_endgrent = a_endgrent; 571 _pwcache_getgrnam = a_getgrnam; 572 _pwcache_getgrgid = a_getgrgid; 573 574 return (0); 575 } 576 577 578 #ifdef TEST_PWCACHE 579 580 struct passwd * 581 test_getpwnam(const char *name) 582 { 583 static struct passwd foo; 584 585 memset(&foo, 0, sizeof(foo)); 586 if (strcmp(name, "toor") == 0) { 587 foo.pw_uid = 666; 588 return &foo; 589 } 590 return (getpwnam(name)); 591 } 592 593 int 594 main(int argc, char *argv[]) 595 { 596 uid_t u; 597 int r, i; 598 599 printf("pass 1 (default userdb)\n"); 600 for (i = 1; i < argc; i++) { 601 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 602 i, pwopn, usrtb_fail, usrtb); 603 r = uid_from_user(argv[i], &u); 604 if (r == -1) 605 printf(" uid_from_user %s: failed\n", argv[i]); 606 else 607 printf(" uid_from_user %s: %d\n", argv[i], u); 608 } 609 printf("pass 1 finish: pwopn %d usrtb_fail %d usrtb %p\n", 610 pwopn, usrtb_fail, usrtb); 611 612 puts(""); 613 printf("pass 2 (replacement userdb)\n"); 614 printf("pwcache_userdb returned %d\n", 615 pwcache_userdb(setpassent, test_getpwnam, getpwuid)); 616 printf("pwopn %d usrtb_fail %d usrtb %p\n", pwopn, usrtb_fail, usrtb); 617 618 for (i = 1; i < argc; i++) { 619 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 620 i, pwopn, usrtb_fail, usrtb); 621 u = -1; 622 r = uid_from_user(argv[i], &u); 623 if (r == -1) 624 printf(" uid_from_user %s: failed\n", argv[i]); 625 else 626 printf(" uid_from_user %s: %d\n", argv[i], u); 627 } 628 printf("pass 2 finish: pwopn %d usrtb_fail %d usrtb %p\n", 629 pwopn, usrtb_fail, usrtb); 630 631 puts(""); 632 printf("pass 3 (null pointers)\n"); 633 printf("pwcache_userdb returned %d\n", 634 pwcache_userdb(NULL, NULL, NULL)); 635 636 return (0); 637 } 638 #endif /* TEST_PWCACHE */ 639 #endif /* !HAVE_PWCACHE_USERDB */ 640
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