pwcache.c revision 1.22
1 /* $NetBSD: pwcache.c,v 1.22 2002/07/03 17:17:35 pooka 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 #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 1.22 2002/07/03 17:17:35 pooka 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 #if !HAVE_USER_FROM_UID 248 /* 249 * user_from_uid() 250 * caches the name (if any) for the uid. If noname clear, we always 251 * return the the stored name (if valid or invalid match). 252 * We use a simple hash table. 253 * Return 254 * Pointer to stored name (or a empty string) 255 */ 256 257 const char * 258 user_from_uid(uid_t uid, int noname) 259 { 260 struct passwd *pw; 261 UIDC *ptr, **pptr; 262 263 if ((uidtb == NULL) && (uidtb_start() < 0)) 264 return (NULL); 265 266 /* 267 * see if we have this uid cached 268 */ 269 pptr = uidtb + (uid % UID_SZ); 270 ptr = *pptr; 271 272 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) { 273 /* 274 * have an entry for this uid 275 */ 276 if (!noname || (ptr->valid == VALID)) 277 return (ptr->name); 278 return (NULL); 279 } 280 281 /* 282 * No entry for this uid, we will add it 283 */ 284 if (!pwopn) { 285 if (_pwcache_setpassent != NULL) 286 (*_pwcache_setpassent)(1); 287 ++pwopn; 288 } 289 290 if (ptr == NULL) 291 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 292 293 if ((pw = (*_pwcache_getpwuid)(uid)) == NULL) { 294 /* 295 * no match for this uid in the local password file 296 * a string that is the uid in numberic format 297 */ 298 if (ptr == NULL) 299 return (NULL); 300 ptr->uid = uid; 301 (void)snprintf(ptr->name, UNMLEN, "%lu", (long) uid); 302 ptr->valid = INVALID; 303 if (noname) 304 return (NULL); 305 } else { 306 /* 307 * there is an entry for this uid in the password file 308 */ 309 if (ptr == NULL) 310 return (pw->pw_name); 311 ptr->uid = uid; 312 (void)strlcpy(ptr->name, pw->pw_name, UNMLEN); 313 ptr->valid = VALID; 314 } 315 return (ptr->name); 316 } 317 318 /* 319 * group_from_gid() 320 * caches the name (if any) for the gid. If noname clear, we always 321 * return the the stored name (if valid or invalid match). 322 * We use a simple hash table. 323 * Return 324 * Pointer to stored name (or a empty string) 325 */ 326 327 const char * 328 group_from_gid(gid_t gid, int noname) 329 { 330 struct group *gr; 331 GIDC *ptr, **pptr; 332 333 if ((gidtb == NULL) && (gidtb_start() < 0)) 334 return (NULL); 335 336 /* 337 * see if we have this gid cached 338 */ 339 pptr = gidtb + (gid % GID_SZ); 340 ptr = *pptr; 341 342 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) { 343 /* 344 * have an entry for this gid 345 */ 346 if (!noname || (ptr->valid == VALID)) 347 return (ptr->name); 348 return (NULL); 349 } 350 351 /* 352 * No entry for this gid, we will add it 353 */ 354 if (!gropn) { 355 if (_pwcache_setgroupent != NULL) 356 (*_pwcache_setgroupent)(1); 357 ++gropn; 358 } 359 360 if (ptr == NULL) 361 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 362 363 if ((gr = (*_pwcache_getgrgid)(gid)) == NULL) { 364 /* 365 * no match for this gid in the local group file, put in 366 * a string that is the gid in numberic format 367 */ 368 if (ptr == NULL) 369 return (NULL); 370 ptr->gid = gid; 371 (void)snprintf(ptr->name, GNMLEN, "%lu", (long) gid); 372 ptr->valid = INVALID; 373 if (noname) 374 return (NULL); 375 } else { 376 /* 377 * there is an entry for this group in the group file 378 */ 379 if (ptr == NULL) 380 return (gr->gr_name); 381 ptr->gid = gid; 382 (void)strlcpy(ptr->name, gr->gr_name, GNMLEN); 383 ptr->valid = VALID; 384 } 385 return (ptr->name); 386 } 387 #endif /* HAVE_USER_FROM_UID */ 388 389 /* 390 * uid_from_user() 391 * caches the uid for a given user name. We use a simple hash table. 392 * Return 393 * the uid (if any) for a user name, or a -1 if no match can be found 394 */ 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 */ 460 461 int 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 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 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 * 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 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
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