1 /* @(#)cache.c 8.1 (Berkeley) 5/31/93 */ 2 /* $NetBSD: pwcache.c,v 1.31 2010/03/23 20:28:59 drochner Exp $ */ 3 4 /*- 5 * Copyright (c) 1992 Keith Muller. 6 * Copyright (c) 1992, 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Keith Muller of the University of California, San Diego. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 /*- 38 * Copyright (c) 2002 The NetBSD Foundation, Inc. 39 * All rights reserved. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 51 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 52 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 53 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 54 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 55 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 56 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 57 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 58 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 59 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 60 * POSSIBILITY OF SUCH DAMAGE. 61 */ 62 63 #if HAVE_NBTOOL_CONFIG_H 64 #include "nbtool_config.h" 65 /* 66 * XXX Undefine the renames of these functions so that we don't 67 * XXX rename the versions found in the host's <pwd.h> by mistake! 68 */ 69 #undef group_from_gid 70 #undef user_from_uid 71 #endif 72 73 #include "namespace.h" 74 75 #include <sys/types.h> 76 #include <sys/param.h> 77 78 #include <assert.h> 79 #include <grp.h> 80 #include <pwd.h> 81 #include <stdio.h> 82 #include <stdlib.h> 83 #include <string.h> 84 #include <unistd.h> 85 #include "un-namespace.h" 86 87 #if HAVE_NBTOOL_CONFIG_H 88 /* XXX Now, re-apply the renaming that we undid above. */ 89 #define group_from_gid __nbcompat_group_from_gid 90 #define user_from_uid __nbcompat_user_from_uid 91 #endif 92 93 #ifdef __weak_alias 94 __weak_alias(user_from_uid,_user_from_uid) 95 __weak_alias(group_from_gid,_group_from_gid) 96 __weak_alias(pwcache_groupdb,_pwcache_groupdb) 97 #endif 98 99 #if !HAVE_PWCACHE_USERDB || HAVE_NBTOOL_CONFIG_H 100 #include "pwcache.h" 101 102 /* 103 * routines that control user, group, uid and gid caches (for the archive 104 * member print routine). 105 * IMPORTANT: 106 * these routines cache BOTH hits and misses, a major performance improvement 107 */ 108 109 /* 110 * function pointers to various name lookup routines. 111 * these may be changed as necessary. 112 */ 113 static int (*_pwcache_setgroupent)(int) = setgroupent; 114 static void (*_pwcache_endgrent)(void) = endgrent; 115 static struct group * (*_pwcache_getgrnam)(const char *) = getgrnam; 116 static struct group * (*_pwcache_getgrgid)(gid_t) = getgrgid; 117 static int (*_pwcache_setpassent)(int) = setpassent; 118 static void (*_pwcache_endpwent)(void) = endpwent; 119 static struct passwd * (*_pwcache_getpwnam)(const char *) = getpwnam; 120 static struct passwd * (*_pwcache_getpwuid)(uid_t) = getpwuid; 121 122 /* 123 * internal state 124 */ 125 static int pwopn; /* is password file open */ 126 static int gropn; /* is group file open */ 127 static UIDC **uidtb; /* uid to name cache */ 128 static GIDC **gidtb; /* gid to name cache */ 129 static UIDC **usrtb; /* user name to uid cache */ 130 static GIDC **grptb; /* group name to gid cache */ 131 132 static int uidtb_fail; /* uidtb_start() failed ? */ 133 static int gidtb_fail; /* gidtb_start() failed ? */ 134 static int usrtb_fail; /* usrtb_start() failed ? */ 135 static int grptb_fail; /* grptb_start() failed ? */ 136 137 138 static u_int st_hash(const char *, size_t, int); 139 static int uidtb_start(void); 140 static int gidtb_start(void); 141 static int usrtb_start(void); 142 static int grptb_start(void); 143 144 145 static u_int 146 st_hash(const char *name, size_t len, int tabsz) 147 { 148 u_int key = 0; 149 150 _DIAGASSERT(name != NULL); 151 152 while (len--) { 153 key += *name++; 154 key = (key << 8) | (key >> 24); 155 } 156 157 return (key % tabsz); 158 } 159 160 /* 161 * uidtb_start 162 * creates an an empty uidtb 163 * Return: 164 * 0 if ok, -1 otherwise 165 */ 166 static int 167 uidtb_start(void) 168 { 169 170 if (uidtb != NULL) 171 return (0); 172 if (uidtb_fail) 173 return (-1); 174 if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) { 175 ++uidtb_fail; 176 return (-1); 177 } 178 return (0); 179 } 180 181 /* 182 * gidtb_start 183 * creates an an empty gidtb 184 * Return: 185 * 0 if ok, -1 otherwise 186 */ 187 static int 188 gidtb_start(void) 189 { 190 191 if (gidtb != NULL) 192 return (0); 193 if (gidtb_fail) 194 return (-1); 195 if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) { 196 ++gidtb_fail; 197 return (-1); 198 } 199 return (0); 200 } 201 202 /* 203 * usrtb_start 204 * creates an an empty usrtb 205 * Return: 206 * 0 if ok, -1 otherwise 207 */ 208 static int 209 usrtb_start(void) 210 { 211 212 if (usrtb != NULL) 213 return (0); 214 if (usrtb_fail) 215 return (-1); 216 if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) { 217 ++usrtb_fail; 218 return (-1); 219 } 220 return (0); 221 } 222 223 /* 224 * grptb_start 225 * creates an an empty grptb 226 * Return: 227 * 0 if ok, -1 otherwise 228 */ 229 static int 230 grptb_start(void) 231 { 232 233 if (grptb != NULL) 234 return (0); 235 if (grptb_fail) 236 return (-1); 237 if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) { 238 ++grptb_fail; 239 return (-1); 240 } 241 return (0); 242 } 243 244 /* 245 * user_from_uid() 246 * caches the name (if any) for the uid. If noname clear, we always 247 * return the stored name (if valid or invalid match). 248 * We use a simple hash table. 249 * Return 250 * Pointer to stored name (or a empty string) 251 */ 252 const char * 253 user_from_uid(uid_t uid, int noname) 254 { 255 struct passwd *pw; 256 UIDC *ptr, **pptr; 257 258 if ((uidtb == NULL) && (uidtb_start() < 0)) 259 return (NULL); 260 261 /* 262 * see if we have this uid cached 263 */ 264 pptr = uidtb + (uid % UID_SZ); 265 ptr = *pptr; 266 267 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) { 268 /* 269 * have an entry for this uid 270 */ 271 if (!noname || (ptr->valid == VALID)) 272 return (ptr->name); 273 return (NULL); 274 } 275 276 /* 277 * No entry for this uid, we will add it 278 */ 279 if (!pwopn) { 280 if (_pwcache_setpassent != NULL) 281 (*_pwcache_setpassent)(1); 282 ++pwopn; 283 } 284 285 if (ptr == NULL) 286 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 287 288 if ((pw = (*_pwcache_getpwuid)(uid)) == NULL) { 289 /* 290 * no match for this uid in the local password file 291 * a string that is the uid in numeric format 292 */ 293 if (ptr == NULL) 294 return (NULL); 295 ptr->uid = uid; 296 snprintf(ptr->name, UNMLEN, "%lu", (long) uid); 297 ptr->valid = INVALID; 298 if (noname) 299 return (NULL); 300 } else { 301 /* 302 * there is an entry for this uid in the password file 303 */ 304 if (ptr == NULL) 305 return (pw->pw_name); 306 ptr->uid = uid; 307 strlcpy(ptr->name, pw->pw_name, UNMLEN); 308 ptr->valid = VALID; 309 } 310 return (ptr->name); 311 } 312 313 /* 314 * group_from_gid() 315 * caches the name (if any) for the gid. If noname clear, we always 316 * return the stored name (if valid or invalid match). 317 * We use a simple hash table. 318 * Return 319 * Pointer to stored name (or a empty string) 320 */ 321 const char * 322 group_from_gid(gid_t gid, int noname) 323 { 324 struct group *gr; 325 GIDC *ptr, **pptr; 326 327 if ((gidtb == NULL) && (gidtb_start() < 0)) 328 return (NULL); 329 330 /* 331 * see if we have this gid cached 332 */ 333 pptr = gidtb + (gid % GID_SZ); 334 ptr = *pptr; 335 336 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) { 337 /* 338 * have an entry for this gid 339 */ 340 if (!noname || (ptr->valid == VALID)) 341 return (ptr->name); 342 return (NULL); 343 } 344 345 /* 346 * No entry for this gid, we will add it 347 */ 348 if (!gropn) { 349 if (_pwcache_setgroupent != NULL) 350 (*_pwcache_setgroupent)(1); 351 ++gropn; 352 } 353 354 if (ptr == NULL) 355 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 356 357 if ((gr = (*_pwcache_getgrgid)(gid)) == NULL) { 358 /* 359 * no match for this gid in the local group file, put in 360 * a string that is the gid in numberic format 361 */ 362 if (ptr == NULL) 363 return (NULL); 364 ptr->gid = gid; 365 snprintf(ptr->name, GNMLEN, "%lu", (long) gid); 366 ptr->valid = INVALID; 367 if (noname) 368 return (NULL); 369 } else { 370 /* 371 * there is an entry for this group in the group file 372 */ 373 if (ptr == NULL) 374 return (gr->gr_name); 375 ptr->gid = gid; 376 strlcpy(ptr->name, gr->gr_name, GNMLEN); 377 ptr->valid = VALID; 378 } 379 return (ptr->name); 380 } 381 382 /* 383 * uid_from_user() 384 * caches the uid for a given user name. We use a simple hash table. 385 * Return 386 * the uid (if any) for a user name, or a -1 if no match can be found 387 */ 388 int 389 uid_from_user(const char *name, uid_t *uid) 390 { 391 struct passwd *pw; 392 UIDC *ptr, **pptr; 393 size_t namelen; 394 395 /* 396 * return -1 for mangled names 397 */ 398 if (name == NULL || ((namelen = strlen(name)) == 0)) 399 return (-1); 400 if ((usrtb == NULL) && (usrtb_start() < 0)) 401 return (-1); 402 403 /* 404 * look up in hash table, if found and valid return the uid, 405 * if found and invalid, return a -1 406 */ 407 pptr = usrtb + st_hash(name, namelen, UNM_SZ); 408 ptr = *pptr; 409 410 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 411 if (ptr->valid == INVALID) 412 return (-1); 413 *uid = ptr->uid; 414 return (0); 415 } 416 417 if (!pwopn) { 418 if (_pwcache_setpassent != NULL) 419 (*_pwcache_setpassent)(1); 420 ++pwopn; 421 } 422 423 if (ptr == NULL) 424 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 425 426 /* 427 * no match, look it up, if no match store it as an invalid entry, 428 * or store the matching uid 429 */ 430 if (ptr == NULL) { 431 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) 432 return (-1); 433 *uid = pw->pw_uid; 434 return (0); 435 } 436 strlcpy(ptr->name, name, UNMLEN); 437 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) { 438 ptr->valid = INVALID; 439 return (-1); 440 } 441 ptr->valid = VALID; 442 *uid = ptr->uid = pw->pw_uid; 443 return (0); 444 } 445 446 /* 447 * gid_from_group() 448 * caches the gid for a given group name. We use a simple hash table. 449 * Return 450 * the gid (if any) for a group name, or a -1 if no match can be found 451 */ 452 int 453 gid_from_group(const char *name, gid_t *gid) 454 { 455 struct group *gr; 456 GIDC *ptr, **pptr; 457 size_t namelen; 458 459 /* 460 * return -1 for mangled names 461 */ 462 if (name == NULL || ((namelen = strlen(name)) == 0)) 463 return (-1); 464 if ((grptb == NULL) && (grptb_start() < 0)) 465 return (-1); 466 467 /* 468 * look up in hash table, if found and valid return the uid, 469 * if found and invalid, return a -1 470 */ 471 pptr = grptb + st_hash(name, namelen, GID_SZ); 472 ptr = *pptr; 473 474 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 475 if (ptr->valid == INVALID) 476 return (-1); 477 *gid = ptr->gid; 478 return (0); 479 } 480 481 if (!gropn) { 482 if (_pwcache_setgroupent != NULL) 483 (*_pwcache_setgroupent)(1); 484 ++gropn; 485 } 486 487 if (ptr == NULL) 488 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 489 490 /* 491 * no match, look it up, if no match store it as an invalid entry, 492 * or store the matching gid 493 */ 494 if (ptr == NULL) { 495 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) 496 return (-1); 497 *gid = gr->gr_gid; 498 return (0); 499 } 500 501 strlcpy(ptr->name, name, GNMLEN); 502 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) { 503 ptr->valid = INVALID; 504 return (-1); 505 } 506 ptr->valid = VALID; 507 *gid = ptr->gid = gr->gr_gid; 508 return (0); 509 } 510 511 #define FLUSHTB(arr, len, fail) \ 512 do { \ 513 if (arr != NULL) { \ 514 for (i = 0; i < len; i++) \ 515 if (arr[i] != NULL) \ 516 free(arr[i]); \ 517 arr = NULL; \ 518 } \ 519 fail = 0; \ 520 } while (/* CONSTCOND */0); 521 522 int 523 pwcache_userdb( 524 int (*a_setpassent)(int), 525 void (*a_endpwent)(void), 526 struct passwd * (*a_getpwnam)(const char *), 527 struct passwd * (*a_getpwuid)(uid_t)) 528 { 529 int i; 530 531 /* a_setpassent and a_endpwent may be NULL */ 532 if (a_getpwnam == NULL || a_getpwuid == NULL) 533 return (-1); 534 535 if (_pwcache_endpwent != NULL) 536 (*_pwcache_endpwent)(); 537 FLUSHTB(uidtb, UID_SZ, uidtb_fail); 538 FLUSHTB(usrtb, UNM_SZ, usrtb_fail); 539 pwopn = 0; 540 _pwcache_setpassent = a_setpassent; 541 _pwcache_endpwent = a_endpwent; 542 _pwcache_getpwnam = a_getpwnam; 543 _pwcache_getpwuid = a_getpwuid; 544 545 return (0); 546 } 547 548 int 549 pwcache_groupdb( 550 int (*a_setgroupent)(int), 551 void (*a_endgrent)(void), 552 struct group * (*a_getgrnam)(const char *), 553 struct group * (*a_getgrgid)(gid_t)) 554 { 555 int i; 556 557 /* a_setgroupent and a_endgrent may be NULL */ 558 if (a_getgrnam == NULL || a_getgrgid == NULL) 559 return (-1); 560 561 if (_pwcache_endgrent != NULL) 562 (*_pwcache_endgrent)(); 563 FLUSHTB(gidtb, GID_SZ, gidtb_fail); 564 FLUSHTB(grptb, GNM_SZ, grptb_fail); 565 gropn = 0; 566 _pwcache_setgroupent = a_setgroupent; 567 _pwcache_endgrent = a_endgrent; 568 _pwcache_getgrnam = a_getgrnam; 569 _pwcache_getgrgid = a_getgrgid; 570 571 return (0); 572 } 573 574 575 #ifdef TEST_PWCACHE 576 577 struct passwd * 578 test_getpwnam(const char *name) 579 { 580 static struct passwd foo; 581 582 memset(&foo, 0, sizeof(foo)); 583 if (strcmp(name, "toor") == 0) { 584 foo.pw_uid = 666; 585 return &foo; 586 } 587 return (getpwnam(name)); 588 } 589 590 int 591 main(int argc, char *argv[]) 592 { 593 uid_t u; 594 int r, i; 595 596 printf("pass 1 (default userdb)\n"); 597 for (i = 1; i < argc; i++) { 598 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 599 i, pwopn, usrtb_fail, usrtb); 600 r = uid_from_user(argv[i], &u); 601 if (r == -1) 602 printf(" uid_from_user %s: failed\n", argv[i]); 603 else 604 printf(" uid_from_user %s: %d\n", argv[i], u); 605 } 606 printf("pass 1 finish: pwopn %d usrtb_fail %d usrtb %p\n", 607 pwopn, usrtb_fail, usrtb); 608 609 puts(""); 610 printf("pass 2 (replacement userdb)\n"); 611 printf("pwcache_userdb returned %d\n", 612 pwcache_userdb(setpassent, test_getpwnam, getpwuid)); 613 printf("pwopn %d usrtb_fail %d usrtb %p\n", pwopn, usrtb_fail, usrtb); 614 615 for (i = 1; i < argc; i++) { 616 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 617 i, pwopn, usrtb_fail, usrtb); 618 u = -1; 619 r = uid_from_user(argv[i], &u); 620 if (r == -1) 621 printf(" uid_from_user %s: failed\n", argv[i]); 622 else 623 printf(" uid_from_user %s: %d\n", argv[i], u); 624 } 625 printf("pass 2 finish: pwopn %d usrtb_fail %d usrtb %p\n", 626 pwopn, usrtb_fail, usrtb); 627 628 puts(""); 629 printf("pass 3 (null pointers)\n"); 630 printf("pwcache_userdb returned %d\n", 631 pwcache_userdb(NULL, NULL, NULL)); 632 633 return (0); 634 } 635 #endif /* TEST_PWCACHE */ 636 #endif /* !HAVE_PWCACHE_USERDB */ 637