pwcache.c revision 1.20
1 /* $NetBSD: pwcache.c,v 1.20 2002/01/29 10:20:30 tv 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 #if HAVE_CONFIG_H 74 #include "config.h" 75 #endif 76 77 #include <sys/cdefs.h> 78 #if defined(LIBC_SCCS) && !defined(lint) 79 #if 0 80 static char sccsid[] = "@(#)cache.c 8.1 (Berkeley) 5/31/93"; 81 #else 82 __RCSID("$NetBSD: pwcache.c,v 1.20 2002/01/29 10:20:30 tv Exp $"); 83 #endif 84 #endif /* LIBC_SCCS and not lint */ 85 86 #include "namespace.h" 87 88 #include <sys/types.h> 89 #include <sys/param.h> 90 91 #include <assert.h> 92 #include <grp.h> 93 #include <pwd.h> 94 #include <stdio.h> 95 #include <stdlib.h> 96 #include <string.h> 97 #include <unistd.h> 98 99 #ifdef __weak_alias 100 __weak_alias(user_from_uid,_user_from_uid) 101 __weak_alias(group_from_gid,_group_from_gid) 102 __weak_alias(pwcache_userdb,_pwcache_userdb) 103 __weak_alias(pwcache_groupdb,_pwcache_groupdb) 104 #endif 105 106 #if !HAVE_PWCACHE_USERDB 107 #include "pwcache.h" 108 109 /* 110 * routines that control user, group, uid and gid caches (for the archive 111 * member print routine). 112 * IMPORTANT: 113 * these routines cache BOTH hits and misses, a major performance improvement 114 */ 115 116 /* 117 * function pointers to various name lookup routines. 118 * these may be changed as necessary. 119 */ 120 static int (*_pwcache_setgroupent)(int) = setgroupent; 121 static void (*_pwcache_endgrent)(void) = endgrent; 122 static struct group * (*_pwcache_getgrnam)(const char *) = getgrnam; 123 static struct group * (*_pwcache_getgrgid)(gid_t) = getgrgid; 124 static int (*_pwcache_setpassent)(int) = setpassent; 125 static void (*_pwcache_endpwent)(void) = endpwent; 126 static struct passwd * (*_pwcache_getpwnam)(const char *) = getpwnam; 127 static struct passwd * (*_pwcache_getpwuid)(uid_t) = getpwuid; 128 129 /* 130 * internal state 131 */ 132 static int pwopn; /* is password file open */ 133 static int gropn; /* is group file open */ 134 static UIDC **uidtb; /* uid to name cache */ 135 static GIDC **gidtb; /* gid to name cache */ 136 static UIDC **usrtb; /* user name to uid cache */ 137 static GIDC **grptb; /* group name to gid cache */ 138 139 static int uidtb_fail; /* uidtb_start() failed ? */ 140 static int gidtb_fail; /* gidtb_start() failed ? */ 141 static int usrtb_fail; /* usrtb_start() failed ? */ 142 static int grptb_fail; /* grptb_start() failed ? */ 143 144 145 static u_int st_hash(const char *, size_t, int); 146 static int uidtb_start(void); 147 static int gidtb_start(void); 148 static int usrtb_start(void); 149 static int grptb_start(void); 150 151 152 static u_int 153 st_hash(const char *name, size_t len, int tabsz) 154 { 155 u_int key = 0; 156 157 _DIAGASSERT(name != NULL); 158 159 while (len--) { 160 key += *name++; 161 key = (key << 8) | (key >> 24); 162 } 163 164 return (key % tabsz); 165 } 166 167 /* 168 * uidtb_start 169 * creates an an empty uidtb 170 * Return: 171 * 0 if ok, -1 otherwise 172 */ 173 static int 174 uidtb_start(void) 175 { 176 177 if (uidtb != NULL) 178 return (0); 179 if (uidtb_fail) 180 return (-1); 181 if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) { 182 ++uidtb_fail; 183 return (-1); 184 } 185 return (0); 186 } 187 188 /* 189 * gidtb_start 190 * creates an an empty gidtb 191 * Return: 192 * 0 if ok, -1 otherwise 193 */ 194 static int 195 gidtb_start(void) 196 { 197 198 if (gidtb != NULL) 199 return (0); 200 if (gidtb_fail) 201 return (-1); 202 if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) { 203 ++gidtb_fail; 204 return (-1); 205 } 206 return (0); 207 } 208 209 /* 210 * usrtb_start 211 * creates an an empty usrtb 212 * Return: 213 * 0 if ok, -1 otherwise 214 */ 215 static int 216 usrtb_start(void) 217 { 218 219 if (usrtb != NULL) 220 return (0); 221 if (usrtb_fail) 222 return (-1); 223 if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) { 224 ++usrtb_fail; 225 return (-1); 226 } 227 return (0); 228 } 229 230 /* 231 * grptb_start 232 * creates an an empty grptb 233 * Return: 234 * 0 if ok, -1 otherwise 235 */ 236 static int 237 grptb_start(void) 238 { 239 240 if (grptb != NULL) 241 return (0); 242 if (grptb_fail) 243 return (-1); 244 if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) { 245 ++grptb_fail; 246 return (-1); 247 } 248 return (0); 249 } 250 251 /* 252 * user_from_uid() 253 * caches the name (if any) for the uid. If noname clear, we always 254 * return the the stored name (if valid or invalid match). 255 * We use a simple hash table. 256 * Return 257 * Pointer to stored name (or a empty string) 258 */ 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 numberic 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 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 */ 329 330 const char * 331 group_from_gid(gid_t gid, int noname) 332 { 333 struct group *gr; 334 GIDC *ptr, **pptr; 335 336 if ((gidtb == NULL) && (gidtb_start() < 0)) 337 return (NULL); 338 339 /* 340 * see if we have this gid cached 341 */ 342 pptr = gidtb + (gid % GID_SZ); 343 ptr = *pptr; 344 345 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) { 346 /* 347 * have an entry for this gid 348 */ 349 if (!noname || (ptr->valid == VALID)) 350 return (ptr->name); 351 return (NULL); 352 } 353 354 /* 355 * No entry for this gid, we will add it 356 */ 357 if (!gropn) { 358 if (_pwcache_setgroupent != NULL) 359 (*_pwcache_setgroupent)(1); 360 ++gropn; 361 } 362 363 if (ptr == NULL) 364 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 365 366 if ((gr = (*_pwcache_getgrgid)(gid)) == NULL) { 367 /* 368 * no match for this gid in the local group file, put in 369 * a string that is the gid in numberic format 370 */ 371 if (ptr == NULL) 372 return (NULL); 373 ptr->gid = gid; 374 (void)snprintf(ptr->name, GNMLEN, "%lu", (long) gid); 375 ptr->valid = INVALID; 376 if (noname) 377 return (NULL); 378 } else { 379 /* 380 * there is an entry for this group in the group file 381 */ 382 if (ptr == NULL) 383 return (gr->gr_name); 384 ptr->gid = gid; 385 (void)strlcpy(ptr->name, gr->gr_name, GNMLEN); 386 ptr->valid = VALID; 387 } 388 return (ptr->name); 389 } 390 391 /* 392 * uid_from_user() 393 * caches the uid for a given user name. We use a simple hash table. 394 * Return 395 * the uid (if any) for a user name, or a -1 if no match can be found 396 */ 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 */ 462 463 int 464 gid_from_group(const char *name, gid_t *gid) 465 { 466 struct group *gr; 467 GIDC *ptr, **pptr; 468 size_t namelen; 469 470 /* 471 * return -1 for mangled names 472 */ 473 if (name == NULL || ((namelen = strlen(name)) == 0)) 474 return (-1); 475 if ((grptb == NULL) && (grptb_start() < 0)) 476 return (-1); 477 478 /* 479 * look up in hash table, if found and valid return the uid, 480 * if found and invalid, return a -1 481 */ 482 pptr = grptb + st_hash(name, namelen, GID_SZ); 483 ptr = *pptr; 484 485 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 486 if (ptr->valid == INVALID) 487 return (-1); 488 *gid = ptr->gid; 489 return (0); 490 } 491 492 if (!gropn) { 493 if (_pwcache_setgroupent != NULL) 494 (*_pwcache_setgroupent)(1); 495 ++gropn; 496 } 497 498 if (ptr == NULL) 499 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 500 501 /* 502 * no match, look it up, if no match store it as an invalid entry, 503 * or store the matching gid 504 */ 505 if (ptr == NULL) { 506 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) 507 return (-1); 508 *gid = gr->gr_gid; 509 return (0); 510 } 511 512 (void)strlcpy(ptr->name, name, GNMLEN); 513 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) { 514 ptr->valid = INVALID; 515 return (-1); 516 } 517 ptr->valid = VALID; 518 *gid = ptr->gid = gr->gr_gid; 519 return (0); 520 } 521 522 #define FLUSHTB(arr, len, fail) \ 523 do { \ 524 if (arr != NULL) { \ 525 for (i = 0; i < len; i++) \ 526 if (arr[i] != NULL) \ 527 free(arr[i]); \ 528 arr = NULL; \ 529 } \ 530 fail = 0; \ 531 } while (/* CONSTCOND */0); 532 533 int 534 pwcache_userdb( 535 int (*a_setpassent)(int), 536 void (*a_endpwent)(void), 537 struct passwd * (*a_getpwnam)(const char *), 538 struct passwd * (*a_getpwuid)(uid_t)) 539 { 540 int i; 541 542 /* a_setpassent and a_endpwent may be NULL */ 543 if (a_getpwnam == NULL || a_getpwuid == NULL) 544 return (-1); 545 546 if (_pwcache_endpwent != NULL) 547 (*_pwcache_endpwent)(); 548 FLUSHTB(uidtb, UID_SZ, uidtb_fail); 549 FLUSHTB(usrtb, UNM_SZ, usrtb_fail); 550 pwopn = 0; 551 _pwcache_setpassent = a_setpassent; 552 _pwcache_endpwent = a_endpwent; 553 _pwcache_getpwnam = a_getpwnam; 554 _pwcache_getpwuid = a_getpwuid; 555 556 return (0); 557 } 558 559 int 560 pwcache_groupdb( 561 int (*a_setgroupent)(int), 562 void (*a_endgrent)(void), 563 struct group * (*a_getgrnam)(const char *), 564 struct group * (*a_getgrgid)(gid_t)) 565 { 566 int i; 567 568 /* a_setgroupent and a_endgrent may be NULL */ 569 if (a_getgrnam == NULL || a_getgrgid == NULL) 570 return (-1); 571 572 if (_pwcache_endgrent != NULL) 573 (*_pwcache_endgrent)(); 574 FLUSHTB(gidtb, GID_SZ, gidtb_fail); 575 FLUSHTB(grptb, GNM_SZ, grptb_fail); 576 gropn = 0; 577 _pwcache_setgroupent = a_setgroupent; 578 _pwcache_endgrent = a_endgrent; 579 _pwcache_getgrnam = a_getgrnam; 580 _pwcache_getgrgid = a_getgrgid; 581 582 return (0); 583 } 584 585 586 #ifdef TEST_PWCACHE 587 588 struct passwd * 589 test_getpwnam(const char *name) 590 { 591 static struct passwd foo; 592 593 memset(&foo, 0, sizeof(foo)); 594 if (strcmp(name, "toor") == 0) { 595 foo.pw_uid = 666; 596 return &foo; 597 } 598 return (getpwnam(name)); 599 } 600 601 int 602 main(int argc, char *argv[]) 603 { 604 uid_t u; 605 int r, i; 606 607 printf("pass 1 (default userdb)\n"); 608 for (i = 1; i < argc; i++) { 609 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 610 i, pwopn, usrtb_fail, usrtb); 611 r = uid_from_user(argv[i], &u); 612 if (r == -1) 613 printf(" uid_from_user %s: failed\n", argv[i]); 614 else 615 printf(" uid_from_user %s: %d\n", argv[i], u); 616 } 617 printf("pass 1 finish: pwopn %d usrtb_fail %d usrtb %p\n", 618 pwopn, usrtb_fail, usrtb); 619 620 puts(""); 621 printf("pass 2 (replacement userdb)\n"); 622 printf("pwcache_userdb returned %d\n", 623 pwcache_userdb(setpassent, test_getpwnam, getpwuid)); 624 printf("pwopn %d usrtb_fail %d usrtb %p\n", pwopn, usrtb_fail, usrtb); 625 626 for (i = 1; i < argc; i++) { 627 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 628 i, pwopn, usrtb_fail, usrtb); 629 u = -1; 630 r = uid_from_user(argv[i], &u); 631 if (r == -1) 632 printf(" uid_from_user %s: failed\n", argv[i]); 633 else 634 printf(" uid_from_user %s: %d\n", argv[i], u); 635 } 636 printf("pass 2 finish: pwopn %d usrtb_fail %d usrtb %p\n", 637 pwopn, usrtb_fail, usrtb); 638 639 puts(""); 640 printf("pass 3 (null pointers)\n"); 641 printf("pwcache_userdb returned %d\n", 642 pwcache_userdb(NULL, NULL, NULL)); 643 644 return (0); 645 } 646 #endif /* TEST_PWCACHE */ 647 #endif /* !HAVE_PWCACHE_USERDB */ 648
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