pwcache.c revision 1.30.8.2
1 /* $NetBSD: pwcache.c,v 1.30.8.2 2008/04/28 20:23:00 martin 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 1.30.8.2 2008/04/28 20:23:00 martin 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 #if HAVE_NBTOOL_CONFIG_H 95 /* XXX Now, re-apply the renaming that we undid above. */ 96 #define group_from_gid __nbcompat_group_from_gid 97 #define user_from_uid __nbcompat_user_from_uid 98 #endif 99 100 #ifdef __weak_alias 101 __weak_alias(user_from_uid,_user_from_uid) 102 __weak_alias(group_from_gid,_group_from_gid) 103 __weak_alias(pwcache_userdb,_pwcache_userdb) 104 __weak_alias(pwcache_groupdb,_pwcache_groupdb) 105 #endif 106 107 #if !HAVE_PWCACHE_USERDB || HAVE_NBTOOL_CONFIG_H 108 #include "pwcache.h" 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 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 const char * 261 user_from_uid(uid_t uid, int noname) 262 { 263 struct passwd *pw; 264 UIDC *ptr, **pptr; 265 266 if ((uidtb == NULL) && (uidtb_start() < 0)) 267 return (NULL); 268 269 /* 270 * see if we have this uid cached 271 */ 272 pptr = uidtb + (uid % UID_SZ); 273 ptr = *pptr; 274 275 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) { 276 /* 277 * have an entry for this uid 278 */ 279 if (!noname || (ptr->valid == VALID)) 280 return (ptr->name); 281 return (NULL); 282 } 283 284 /* 285 * No entry for this uid, we will add it 286 */ 287 if (!pwopn) { 288 if (_pwcache_setpassent != NULL) 289 (*_pwcache_setpassent)(1); 290 ++pwopn; 291 } 292 293 if (ptr == NULL) 294 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 295 296 if ((pw = (*_pwcache_getpwuid)(uid)) == NULL) { 297 /* 298 * no match for this uid in the local password file 299 * a string that is the uid in numeric format 300 */ 301 if (ptr == NULL) 302 return (NULL); 303 ptr->uid = uid; 304 (void)snprintf(ptr->name, UNMLEN, "%lu", (long) uid); 305 ptr->valid = INVALID; 306 if (noname) 307 return (NULL); 308 } else { 309 /* 310 * there is an entry for this uid in the password file 311 */ 312 if (ptr == NULL) 313 return (pw->pw_name); 314 ptr->uid = uid; 315 (void)strlcpy(ptr->name, pw->pw_name, UNMLEN); 316 ptr->valid = VALID; 317 } 318 return (ptr->name); 319 } 320 321 /* 322 * group_from_gid() 323 * caches the name (if any) for the gid. If noname clear, we always 324 * return the stored name (if valid or invalid match). 325 * We use a simple hash table. 326 * Return 327 * Pointer to stored name (or a empty string) 328 */ 329 const char * 330 group_from_gid(gid_t gid, int noname) 331 { 332 struct group *gr; 333 GIDC *ptr, **pptr; 334 335 if ((gidtb == NULL) && (gidtb_start() < 0)) 336 return (NULL); 337 338 /* 339 * see if we have this gid cached 340 */ 341 pptr = gidtb + (gid % GID_SZ); 342 ptr = *pptr; 343 344 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) { 345 /* 346 * have an entry for this gid 347 */ 348 if (!noname || (ptr->valid == VALID)) 349 return (ptr->name); 350 return (NULL); 351 } 352 353 /* 354 * No entry for this gid, we will add it 355 */ 356 if (!gropn) { 357 if (_pwcache_setgroupent != NULL) 358 (*_pwcache_setgroupent)(1); 359 ++gropn; 360 } 361 362 if (ptr == NULL) 363 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 364 365 if ((gr = (*_pwcache_getgrgid)(gid)) == NULL) { 366 /* 367 * no match for this gid in the local group file, put in 368 * a string that is the gid in numberic format 369 */ 370 if (ptr == NULL) 371 return (NULL); 372 ptr->gid = gid; 373 (void)snprintf(ptr->name, GNMLEN, "%lu", (long) gid); 374 ptr->valid = INVALID; 375 if (noname) 376 return (NULL); 377 } else { 378 /* 379 * there is an entry for this group in the group file 380 */ 381 if (ptr == NULL) 382 return (gr->gr_name); 383 ptr->gid = gid; 384 (void)strlcpy(ptr->name, gr->gr_name, GNMLEN); 385 ptr->valid = VALID; 386 } 387 return (ptr->name); 388 } 389 390 /* 391 * uid_from_user() 392 * caches the uid for a given user name. We use a simple hash table. 393 * Return 394 * the uid (if any) for a user name, or a -1 if no match can be found 395 */ 396 int 397 uid_from_user(const char *name, uid_t *uid) 398 { 399 struct passwd *pw; 400 UIDC *ptr, **pptr; 401 size_t namelen; 402 403 /* 404 * return -1 for mangled names 405 */ 406 if (name == NULL || ((namelen = strlen(name)) == 0)) 407 return (-1); 408 if ((usrtb == NULL) && (usrtb_start() < 0)) 409 return (-1); 410 411 /* 412 * look up in hash table, if found and valid return the uid, 413 * if found and invalid, return a -1 414 */ 415 pptr = usrtb + st_hash(name, namelen, UNM_SZ); 416 ptr = *pptr; 417 418 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 419 if (ptr->valid == INVALID) 420 return (-1); 421 *uid = ptr->uid; 422 return (0); 423 } 424 425 if (!pwopn) { 426 if (_pwcache_setpassent != NULL) 427 (*_pwcache_setpassent)(1); 428 ++pwopn; 429 } 430 431 if (ptr == NULL) 432 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 433 434 /* 435 * no match, look it up, if no match store it as an invalid entry, 436 * or store the matching uid 437 */ 438 if (ptr == NULL) { 439 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) 440 return (-1); 441 *uid = pw->pw_uid; 442 return (0); 443 } 444 (void)strlcpy(ptr->name, name, UNMLEN); 445 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) { 446 ptr->valid = INVALID; 447 return (-1); 448 } 449 ptr->valid = VALID; 450 *uid = ptr->uid = pw->pw_uid; 451 return (0); 452 } 453 454 /* 455 * gid_from_group() 456 * caches the gid for a given group name. We use a simple hash table. 457 * Return 458 * the gid (if any) for a group name, or a -1 if no match can be found 459 */ 460 int 461 gid_from_group(const char *name, gid_t *gid) 462 { 463 struct group *gr; 464 GIDC *ptr, **pptr; 465 size_t namelen; 466 467 /* 468 * return -1 for mangled names 469 */ 470 if (name == NULL || ((namelen = strlen(name)) == 0)) 471 return (-1); 472 if ((grptb == NULL) && (grptb_start() < 0)) 473 return (-1); 474 475 /* 476 * look up in hash table, if found and valid return the uid, 477 * if found and invalid, return a -1 478 */ 479 pptr = grptb + st_hash(name, namelen, GID_SZ); 480 ptr = *pptr; 481 482 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 483 if (ptr->valid == INVALID) 484 return (-1); 485 *gid = ptr->gid; 486 return (0); 487 } 488 489 if (!gropn) { 490 if (_pwcache_setgroupent != NULL) 491 (*_pwcache_setgroupent)(1); 492 ++gropn; 493 } 494 495 if (ptr == NULL) 496 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 497 498 /* 499 * no match, look it up, if no match store it as an invalid entry, 500 * or store the matching gid 501 */ 502 if (ptr == NULL) { 503 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) 504 return (-1); 505 *gid = gr->gr_gid; 506 return (0); 507 } 508 509 (void)strlcpy(ptr->name, name, GNMLEN); 510 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) { 511 ptr->valid = INVALID; 512 return (-1); 513 } 514 ptr->valid = VALID; 515 *gid = ptr->gid = gr->gr_gid; 516 return (0); 517 } 518 519 #define FLUSHTB(arr, len, fail) \ 520 do { \ 521 if (arr != NULL) { \ 522 for (i = 0; i < len; i++) \ 523 if (arr[i] != NULL) \ 524 free(arr[i]); \ 525 arr = NULL; \ 526 } \ 527 fail = 0; \ 528 } while (/* CONSTCOND */0); 529 530 int 531 pwcache_userdb( 532 int (*a_setpassent)(int), 533 void (*a_endpwent)(void), 534 struct passwd * (*a_getpwnam)(const char *), 535 struct passwd * (*a_getpwuid)(uid_t)) 536 { 537 int i; 538 539 /* a_setpassent and a_endpwent may be NULL */ 540 if (a_getpwnam == NULL || a_getpwuid == NULL) 541 return (-1); 542 543 if (_pwcache_endpwent != NULL) 544 (*_pwcache_endpwent)(); 545 FLUSHTB(uidtb, UID_SZ, uidtb_fail); 546 FLUSHTB(usrtb, UNM_SZ, usrtb_fail); 547 pwopn = 0; 548 _pwcache_setpassent = a_setpassent; 549 _pwcache_endpwent = a_endpwent; 550 _pwcache_getpwnam = a_getpwnam; 551 _pwcache_getpwuid = a_getpwuid; 552 553 return (0); 554 } 555 556 int 557 pwcache_groupdb( 558 int (*a_setgroupent)(int), 559 void (*a_endgrent)(void), 560 struct group * (*a_getgrnam)(const char *), 561 struct group * (*a_getgrgid)(gid_t)) 562 { 563 int i; 564 565 /* a_setgroupent and a_endgrent may be NULL */ 566 if (a_getgrnam == NULL || a_getgrgid == NULL) 567 return (-1); 568 569 if (_pwcache_endgrent != NULL) 570 (*_pwcache_endgrent)(); 571 FLUSHTB(gidtb, GID_SZ, gidtb_fail); 572 FLUSHTB(grptb, GNM_SZ, grptb_fail); 573 gropn = 0; 574 _pwcache_setgroupent = a_setgroupent; 575 _pwcache_endgrent = a_endgrent; 576 _pwcache_getgrnam = a_getgrnam; 577 _pwcache_getgrgid = a_getgrgid; 578 579 return (0); 580 } 581 582 583 #ifdef TEST_PWCACHE 584 585 struct passwd * 586 test_getpwnam(const char *name) 587 { 588 static struct passwd foo; 589 590 memset(&foo, 0, sizeof(foo)); 591 if (strcmp(name, "toor") == 0) { 592 foo.pw_uid = 666; 593 return &foo; 594 } 595 return (getpwnam(name)); 596 } 597 598 int 599 main(int argc, char *argv[]) 600 { 601 uid_t u; 602 int r, i; 603 604 printf("pass 1 (default userdb)\n"); 605 for (i = 1; i < argc; i++) { 606 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 607 i, pwopn, usrtb_fail, usrtb); 608 r = uid_from_user(argv[i], &u); 609 if (r == -1) 610 printf(" uid_from_user %s: failed\n", argv[i]); 611 else 612 printf(" uid_from_user %s: %d\n", argv[i], u); 613 } 614 printf("pass 1 finish: pwopn %d usrtb_fail %d usrtb %p\n", 615 pwopn, usrtb_fail, usrtb); 616 617 puts(""); 618 printf("pass 2 (replacement userdb)\n"); 619 printf("pwcache_userdb returned %d\n", 620 pwcache_userdb(setpassent, test_getpwnam, getpwuid)); 621 printf("pwopn %d usrtb_fail %d usrtb %p\n", pwopn, usrtb_fail, usrtb); 622 623 for (i = 1; i < argc; i++) { 624 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 625 i, pwopn, usrtb_fail, usrtb); 626 u = -1; 627 r = uid_from_user(argv[i], &u); 628 if (r == -1) 629 printf(" uid_from_user %s: failed\n", argv[i]); 630 else 631 printf(" uid_from_user %s: %d\n", argv[i], u); 632 } 633 printf("pass 2 finish: pwopn %d usrtb_fail %d usrtb %p\n", 634 pwopn, usrtb_fail, usrtb); 635 636 puts(""); 637 printf("pass 3 (null pointers)\n"); 638 printf("pwcache_userdb returned %d\n", 639 pwcache_userdb(NULL, NULL, NULL)); 640 641 return (0); 642 } 643 #endif /* TEST_PWCACHE */ 644 #endif /* !HAVE_PWCACHE_USERDB */ 645
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