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 $"); 78 #endif 79 #endif /* LIBC_SCCS and not lint */ 80 __FBSDID("$FreeBSD$"); 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 #define _DIAGASSERT(x) assert((x)) 96 97 #if HAVE_NBTOOL_CONFIG_H 98 /* XXX Now, re-apply the renaming that we undid above. */ 99 #define group_from_gid __nbcompat_group_from_gid 100 #define user_from_uid __nbcompat_user_from_uid 101 #endif 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_groupdb,_pwcache_groupdb) 107 #endif 108 109 #if !HAVE_PWCACHE_USERDB || HAVE_NBTOOL_CONFIG_H 110 #include "pwcache.h" 111 112 /* 113 * routines that control user, group, uid and gid caches (for the archive 114 * member print routine). 115 * IMPORTANT: 116 * these routines cache BOTH hits and misses, a major performance improvement 117 */ 118 119 /* 120 * function pointers to various name lookup routines. 121 * these may be changed as necessary. 122 */ 123 static int (*_pwcache_setgroupent)(int) = setgroupent; 124 static void (*_pwcache_endgrent)(void) = endgrent; 125 static struct group * (*_pwcache_getgrnam)(const char *) = getgrnam; 126 static struct group * (*_pwcache_getgrgid)(gid_t) = getgrgid; 127 static int (*_pwcache_setpassent)(int) = setpassent; 128 static void (*_pwcache_endpwent)(void) = endpwent; 129 static struct passwd * (*_pwcache_getpwnam)(const char *) = getpwnam; 130 static struct passwd * (*_pwcache_getpwuid)(uid_t) = getpwuid; 131 132 /* 133 * internal state 134 */ 135 static int pwopn; /* is password file open */ 136 static int gropn; /* is group file open */ 137 static UIDC **uidtb; /* uid to name cache */ 138 static GIDC **gidtb; /* gid to name cache */ 139 static UIDC **usrtb; /* user name to uid cache */ 140 static GIDC **grptb; /* group name to gid cache */ 141 142 static int uidtb_fail; /* uidtb_start() failed ? */ 143 static int gidtb_fail; /* gidtb_start() failed ? */ 144 static int usrtb_fail; /* usrtb_start() failed ? */ 145 static int grptb_fail; /* grptb_start() failed ? */ 146 147 148 static u_int st_hash(const char *, size_t, int); 149 static int uidtb_start(void); 150 static int gidtb_start(void); 151 static int usrtb_start(void); 152 static int grptb_start(void); 153 154 155 static u_int 156 st_hash(const char *name, size_t len, int tabsz) 157 { 158 u_int key = 0; 159 160 _DIAGASSERT(name != NULL); 161 162 while (len--) { 163 key += *name++; 164 key = (key << 8) | (key >> 24); 165 } 166 167 return (key % tabsz); 168 } 169 170 /* 171 * uidtb_start 172 * creates an an empty uidtb 173 * Return: 174 * 0 if ok, -1 otherwise 175 */ 176 static int 177 uidtb_start(void) 178 { 179 180 if (uidtb != NULL) 181 return (0); 182 if (uidtb_fail) 183 return (-1); 184 if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) { 185 ++uidtb_fail; 186 return (-1); 187 } 188 return (0); 189 } 190 191 /* 192 * gidtb_start 193 * creates an an empty gidtb 194 * Return: 195 * 0 if ok, -1 otherwise 196 */ 197 static int 198 gidtb_start(void) 199 { 200 201 if (gidtb != NULL) 202 return (0); 203 if (gidtb_fail) 204 return (-1); 205 if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) { 206 ++gidtb_fail; 207 return (-1); 208 } 209 return (0); 210 } 211 212 /* 213 * usrtb_start 214 * creates an an empty usrtb 215 * Return: 216 * 0 if ok, -1 otherwise 217 */ 218 static int 219 usrtb_start(void) 220 { 221 222 if (usrtb != NULL) 223 return (0); 224 if (usrtb_fail) 225 return (-1); 226 if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) { 227 ++usrtb_fail; 228 return (-1); 229 } 230 return (0); 231 } 232 233 /* 234 * grptb_start 235 * creates an an empty grptb 236 * Return: 237 * 0 if ok, -1 otherwise 238 */ 239 static int 240 grptb_start(void) 241 { 242 243 if (grptb != NULL) 244 return (0); 245 if (grptb_fail) 246 return (-1); 247 if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) { 248 ++grptb_fail; 249 return (-1); 250 } 251 return (0); 252 } 253 254 /* 255 * user_from_uid() 256 * caches the name (if any) for the uid. If noname clear, we always 257 * return the stored name (if valid or invalid match). 258 * We use a simple hash table. 259 * Return 260 * Pointer to stored name (or a empty string) 261 */ 262 const char * 263 user_from_uid(uid_t uid, int noname) 264 { 265 struct passwd *pw; 266 UIDC *ptr, **pptr; 267 268 if ((uidtb == NULL) && (uidtb_start() < 0)) 269 return (NULL); 270 271 /* 272 * see if we have this uid cached 273 */ 274 pptr = uidtb + (uid % UID_SZ); 275 ptr = *pptr; 276 277 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) { 278 /* 279 * have an entry for this uid 280 */ 281 if (!noname || (ptr->valid == VALID)) 282 return (ptr->name); 283 return (NULL); 284 } 285 286 /* 287 * No entry for this uid, we will add it 288 */ 289 if (!pwopn) { 290 if (_pwcache_setpassent != NULL) 291 (*_pwcache_setpassent)(1); 292 ++pwopn; 293 } 294 295 if (ptr == NULL) 296 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 297 298 if ((pw = (*_pwcache_getpwuid)(uid)) == NULL) { 299 /* 300 * no match for this uid in the local password file 301 * a string that is the uid in numeric format 302 */ 303 if (ptr == NULL) 304 return (NULL); 305 ptr->uid = uid; 306 (void)snprintf(ptr->name, UNMLEN, "%lu", (long) uid); 307 ptr->valid = INVALID; 308 if (noname) 309 return (NULL); 310 } else { 311 /* 312 * there is an entry for this uid in the password file 313 */ 314 if (ptr == NULL) 315 return (pw->pw_name); 316 ptr->uid = uid; 317 (void)strlcpy(ptr->name, pw->pw_name, UNMLEN); 318 ptr->valid = VALID; 319 } 320 return (ptr->name); 321 } 322 323 /* 324 * group_from_gid() 325 * caches the name (if any) for the gid. If noname clear, we always 326 * return the stored name (if valid or invalid match). 327 * We use a simple hash table. 328 * Return 329 * Pointer to stored name (or a empty string) 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 int 399 uid_from_user(const char *name, uid_t *uid) 400 { 401 struct passwd *pw; 402 UIDC *ptr, **pptr; 403 size_t namelen; 404 405 /* 406 * return -1 for mangled names 407 */ 408 if (name == NULL || ((namelen = strlen(name)) == 0)) 409 return (-1); 410 if ((usrtb == NULL) && (usrtb_start() < 0)) 411 return (-1); 412 413 /* 414 * look up in hash table, if found and valid return the uid, 415 * if found and invalid, return a -1 416 */ 417 pptr = usrtb + st_hash(name, namelen, UNM_SZ); 418 ptr = *pptr; 419 420 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 421 if (ptr->valid == INVALID) 422 return (-1); 423 *uid = ptr->uid; 424 return (0); 425 } 426 427 if (!pwopn) { 428 if (_pwcache_setpassent != NULL) 429 (*_pwcache_setpassent)(1); 430 ++pwopn; 431 } 432 433 if (ptr == NULL) 434 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 435 436 /* 437 * no match, look it up, if no match store it as an invalid entry, 438 * or store the matching uid 439 */ 440 if (ptr == NULL) { 441 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) 442 return (-1); 443 *uid = pw->pw_uid; 444 return (0); 445 } 446 (void)strlcpy(ptr->name, name, UNMLEN); 447 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) { 448 ptr->valid = INVALID; 449 return (-1); 450 } 451 ptr->valid = VALID; 452 *uid = ptr->uid = pw->pw_uid; 453 return (0); 454 } 455 456 /* 457 * gid_from_group() 458 * caches the gid for a given group name. We use a simple hash table. 459 * Return 460 * the gid (if any) for a group name, or a -1 if no match can be found 461 */ 462 int 463 gid_from_group(const char *name, gid_t *gid) 464 { 465 struct group *gr; 466 GIDC *ptr, **pptr; 467 size_t namelen; 468 469 /* 470 * return -1 for mangled names 471 */ 472 if (name == NULL || ((namelen = strlen(name)) == 0)) 473 return (-1); 474 if ((grptb == NULL) && (grptb_start() < 0)) 475 return (-1); 476 477 /* 478 * look up in hash table, if found and valid return the uid, 479 * if found and invalid, return a -1 480 */ 481 pptr = grptb + st_hash(name, namelen, GID_SZ); 482 ptr = *pptr; 483 484 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 485 if (ptr->valid == INVALID) 486 return (-1); 487 *gid = ptr->gid; 488 return (0); 489 } 490 491 if (!gropn) { 492 if (_pwcache_setgroupent != NULL) 493 (*_pwcache_setgroupent)(1); 494 ++gropn; 495 } 496 497 if (ptr == NULL) 498 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 499 500 /* 501 * no match, look it up, if no match store it as an invalid entry, 502 * or store the matching gid 503 */ 504 if (ptr == NULL) { 505 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) 506 return (-1); 507 *gid = gr->gr_gid; 508 return (0); 509 } 510 511 (void)strlcpy(ptr->name, name, GNMLEN); 512 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) { 513 ptr->valid = INVALID; 514 return (-1); 515 } 516 ptr->valid = VALID; 517 *gid = ptr->gid = gr->gr_gid; 518 return (0); 519 } 520 521 #define FLUSHTB(arr, len, fail) \ 522 do { \ 523 if (arr != NULL) { \ 524 for (i = 0; i < len; i++) \ 525 if (arr[i] != NULL) \ 526 free(arr[i]); \ 527 arr = NULL; \ 528 } \ 529 fail = 0; \ 530 } while (/* CONSTCOND */0); 531 532 int 533 pwcache_userdb( 534 int (*a_setpassent)(int), 535 void (*a_endpwent)(void), 536 struct passwd * (*a_getpwnam)(const char *), 537 struct passwd * (*a_getpwuid)(uid_t)) 538 { 539 int i; 540 541 /* a_setpassent and a_endpwent may be NULL */ 542 if (a_getpwnam == NULL || a_getpwuid == NULL) 543 return (-1); 544 545 if (_pwcache_endpwent != NULL) 546 (*_pwcache_endpwent)(); 547 FLUSHTB(uidtb, UID_SZ, uidtb_fail); 548 FLUSHTB(usrtb, UNM_SZ, usrtb_fail); 549 pwopn = 0; 550 _pwcache_setpassent = a_setpassent; 551 _pwcache_endpwent = a_endpwent; 552 _pwcache_getpwnam = a_getpwnam; 553 _pwcache_getpwuid = a_getpwuid; 554 555 return (0); 556 } 557 558 int 559 pwcache_groupdb( 560 int (*a_setgroupent)(int), 561 void (*a_endgrent)(void), 562 struct group * (*a_getgrnam)(const char *), 563 struct group * (*a_getgrgid)(gid_t)) 564 { 565 int i; 566 567 /* a_setgroupent and a_endgrent may be NULL */ 568 if (a_getgrnam == NULL || a_getgrgid == NULL) 569 return (-1); 570 571 if (_pwcache_endgrent != NULL) 572 (*_pwcache_endgrent)(); 573 FLUSHTB(gidtb, GID_SZ, gidtb_fail); 574 FLUSHTB(grptb, GNM_SZ, grptb_fail); 575 gropn = 0; 576 _pwcache_setgroupent = a_setgroupent; 577 _pwcache_endgrent = a_endgrent; 578 _pwcache_getgrnam = a_getgrnam; 579 _pwcache_getgrgid = a_getgrgid; 580 581 return (0); 582 } 583 584 585 #ifdef TEST_PWCACHE 586 587 struct passwd * 588 test_getpwnam(const char *name) 589 { 590 static struct passwd foo; 591 592 memset(&foo, 0, sizeof(foo)); 593 if (strcmp(name, "toor") == 0) { 594 foo.pw_uid = 666; 595 return &foo; 596 } 597 return (getpwnam(name)); 598 } 599 600 int 601 main(int argc, char *argv[]) 602 { 603 uid_t u; 604 int r, i; 605 606 printf("pass 1 (default userdb)\n"); 607 for (i = 1; i < argc; i++) { 608 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 609 i, pwopn, usrtb_fail, usrtb); 610 r = uid_from_user(argv[i], &u); 611 if (r == -1) 612 printf(" uid_from_user %s: failed\n", argv[i]); 613 else 614 printf(" uid_from_user %s: %d\n", argv[i], u); 615 } 616 printf("pass 1 finish: pwopn %d usrtb_fail %d usrtb %p\n", 617 pwopn, usrtb_fail, usrtb); 618 619 puts(""); 620 printf("pass 2 (replacement userdb)\n"); 621 printf("pwcache_userdb returned %d\n", 622 pwcache_userdb(setpassent, test_getpwnam, getpwuid)); 623 printf("pwopn %d usrtb_fail %d usrtb %p\n", pwopn, usrtb_fail, usrtb); 624 625 for (i = 1; i < argc; i++) { 626 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 627 i, pwopn, usrtb_fail, usrtb); 628 u = -1; 629 r = uid_from_user(argv[i], &u); 630 if (r == -1) 631 printf(" uid_from_user %s: failed\n", argv[i]); 632 else 633 printf(" uid_from_user %s: %d\n", argv[i], u); 634 } 635 printf("pass 2 finish: pwopn %d usrtb_fail %d usrtb %p\n", 636 pwopn, usrtb_fail, usrtb); 637 638 puts(""); 639 printf("pass 3 (null pointers)\n"); 640 printf("pwcache_userdb returned %d\n", 641 pwcache_userdb(NULL, NULL, NULL)); 642 643 return (0); 644 } 645 #endif /* TEST_PWCACHE */ 646 #endif /* !HAVE_PWCACHE_USERDB */ 647