1 /* $NetBSD: pwcache.c,v 1.21 2002/02/26 22:29:40 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 #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 1.21 2002/02/26 22:29:40 tv 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 /* 248 * user_from_uid() 249 * caches the name (if any) for the uid. If noname clear, we always 250 * return the the stored name (if valid or invalid match). 251 * We use a simple hash table. 252 * Return 253 * Pointer to stored name (or a empty string) 254 */ 255 256 const char * 257 user_from_uid(uid_t uid, int noname) 258 { 259 struct passwd *pw; 260 UIDC *ptr, **pptr; 261 262 if ((uidtb == NULL) && (uidtb_start() < 0)) 263 return (NULL); 264 265 /* 266 * see if we have this uid cached 267 */ 268 pptr = uidtb + (uid % UID_SZ); 269 ptr = *pptr; 270 271 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) { 272 /* 273 * have an entry for this uid 274 */ 275 if (!noname || (ptr->valid == VALID)) 276 return (ptr->name); 277 return (NULL); 278 } 279 280 /* 281 * No entry for this uid, we will add it 282 */ 283 if (!pwopn) { 284 if (_pwcache_setpassent != NULL) 285 (*_pwcache_setpassent)(1); 286 ++pwopn; 287 } 288 289 if (ptr == NULL) 290 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 291 292 if ((pw = (*_pwcache_getpwuid)(uid)) == NULL) { 293 /* 294 * no match for this uid in the local password file 295 * a string that is the uid in numberic format 296 */ 297 if (ptr == NULL) 298 return (NULL); 299 ptr->uid = uid; 300 (void)snprintf(ptr->name, UNMLEN, "%lu", (long) uid); 301 ptr->valid = INVALID; 302 if (noname) 303 return (NULL); 304 } else { 305 /* 306 * there is an entry for this uid in the password file 307 */ 308 if (ptr == NULL) 309 return (pw->pw_name); 310 ptr->uid = uid; 311 (void)strlcpy(ptr->name, pw->pw_name, UNMLEN); 312 ptr->valid = VALID; 313 } 314 return (ptr->name); 315 } 316 317 /* 318 * group_from_gid() 319 * caches the name (if any) for the gid. If noname clear, we always 320 * return the the stored name (if valid or invalid match). 321 * We use a simple hash table. 322 * Return 323 * Pointer to stored name (or a empty string) 324 */ 325 326 const char * 327 group_from_gid(gid_t gid, int noname) 328 { 329 struct group *gr; 330 GIDC *ptr, **pptr; 331 332 if ((gidtb == NULL) && (gidtb_start() < 0)) 333 return (NULL); 334 335 /* 336 * see if we have this gid cached 337 */ 338 pptr = gidtb + (gid % GID_SZ); 339 ptr = *pptr; 340 341 if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) { 342 /* 343 * have an entry for this gid 344 */ 345 if (!noname || (ptr->valid == VALID)) 346 return (ptr->name); 347 return (NULL); 348 } 349 350 /* 351 * No entry for this gid, we will add it 352 */ 353 if (!gropn) { 354 if (_pwcache_setgroupent != NULL) 355 (*_pwcache_setgroupent)(1); 356 ++gropn; 357 } 358 359 if (ptr == NULL) 360 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 361 362 if ((gr = (*_pwcache_getgrgid)(gid)) == NULL) { 363 /* 364 * no match for this gid in the local group file, put in 365 * a string that is the gid in numberic format 366 */ 367 if (ptr == NULL) 368 return (NULL); 369 ptr->gid = gid; 370 (void)snprintf(ptr->name, GNMLEN, "%lu", (long) gid); 371 ptr->valid = INVALID; 372 if (noname) 373 return (NULL); 374 } else { 375 /* 376 * there is an entry for this group in the group file 377 */ 378 if (ptr == NULL) 379 return (gr->gr_name); 380 ptr->gid = gid; 381 (void)strlcpy(ptr->name, gr->gr_name, GNMLEN); 382 ptr->valid = VALID; 383 } 384 return (ptr->name); 385 } 386 387 /* 388 * uid_from_user() 389 * caches the uid for a given user name. We use a simple hash table. 390 * Return 391 * the uid (if any) for a user name, or a -1 if no match can be found 392 */ 393 394 int 395 uid_from_user(const char *name, uid_t *uid) 396 { 397 struct passwd *pw; 398 UIDC *ptr, **pptr; 399 size_t namelen; 400 401 /* 402 * return -1 for mangled names 403 */ 404 if (name == NULL || ((namelen = strlen(name)) == 0)) 405 return (-1); 406 if ((usrtb == NULL) && (usrtb_start() < 0)) 407 return (-1); 408 409 /* 410 * look up in hash table, if found and valid return the uid, 411 * if found and invalid, return a -1 412 */ 413 pptr = usrtb + st_hash(name, namelen, UNM_SZ); 414 ptr = *pptr; 415 416 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 417 if (ptr->valid == INVALID) 418 return (-1); 419 *uid = ptr->uid; 420 return (0); 421 } 422 423 if (!pwopn) { 424 if (_pwcache_setpassent != NULL) 425 (*_pwcache_setpassent)(1); 426 ++pwopn; 427 } 428 429 if (ptr == NULL) 430 *pptr = ptr = (UIDC *)malloc(sizeof(UIDC)); 431 432 /* 433 * no match, look it up, if no match store it as an invalid entry, 434 * or store the matching uid 435 */ 436 if (ptr == NULL) { 437 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) 438 return (-1); 439 *uid = pw->pw_uid; 440 return (0); 441 } 442 (void)strlcpy(ptr->name, name, UNMLEN); 443 if ((pw = (*_pwcache_getpwnam)(name)) == NULL) { 444 ptr->valid = INVALID; 445 return (-1); 446 } 447 ptr->valid = VALID; 448 *uid = ptr->uid = pw->pw_uid; 449 return (0); 450 } 451 452 /* 453 * gid_from_group() 454 * caches the gid for a given group name. We use a simple hash table. 455 * Return 456 * the gid (if any) for a group name, or a -1 if no match can be found 457 */ 458 459 int 460 gid_from_group(const char *name, gid_t *gid) 461 { 462 struct group *gr; 463 GIDC *ptr, **pptr; 464 size_t namelen; 465 466 /* 467 * return -1 for mangled names 468 */ 469 if (name == NULL || ((namelen = strlen(name)) == 0)) 470 return (-1); 471 if ((grptb == NULL) && (grptb_start() < 0)) 472 return (-1); 473 474 /* 475 * look up in hash table, if found and valid return the uid, 476 * if found and invalid, return a -1 477 */ 478 pptr = grptb + st_hash(name, namelen, GID_SZ); 479 ptr = *pptr; 480 481 if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) { 482 if (ptr->valid == INVALID) 483 return (-1); 484 *gid = ptr->gid; 485 return (0); 486 } 487 488 if (!gropn) { 489 if (_pwcache_setgroupent != NULL) 490 (*_pwcache_setgroupent)(1); 491 ++gropn; 492 } 493 494 if (ptr == NULL) 495 *pptr = ptr = (GIDC *)malloc(sizeof(GIDC)); 496 497 /* 498 * no match, look it up, if no match store it as an invalid entry, 499 * or store the matching gid 500 */ 501 if (ptr == NULL) { 502 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) 503 return (-1); 504 *gid = gr->gr_gid; 505 return (0); 506 } 507 508 (void)strlcpy(ptr->name, name, GNMLEN); 509 if ((gr = (*_pwcache_getgrnam)(name)) == NULL) { 510 ptr->valid = INVALID; 511 return (-1); 512 } 513 ptr->valid = VALID; 514 *gid = ptr->gid = gr->gr_gid; 515 return (0); 516 } 517 518 #define FLUSHTB(arr, len, fail) \ 519 do { \ 520 if (arr != NULL) { \ 521 for (i = 0; i < len; i++) \ 522 if (arr[i] != NULL) \ 523 free(arr[i]); \ 524 arr = NULL; \ 525 } \ 526 fail = 0; \ 527 } while (/* CONSTCOND */0); 528 529 int 530 pwcache_userdb( 531 int (*a_setpassent)(int), 532 void (*a_endpwent)(void), 533 struct passwd * (*a_getpwnam)(const char *), 534 struct passwd * (*a_getpwuid)(uid_t)) 535 { 536 int i; 537 538 /* a_setpassent and a_endpwent may be NULL */ 539 if (a_getpwnam == NULL || a_getpwuid == NULL) 540 return (-1); 541 542 if (_pwcache_endpwent != NULL) 543 (*_pwcache_endpwent)(); 544 FLUSHTB(uidtb, UID_SZ, uidtb_fail); 545 FLUSHTB(usrtb, UNM_SZ, usrtb_fail); 546 pwopn = 0; 547 _pwcache_setpassent = a_setpassent; 548 _pwcache_endpwent = a_endpwent; 549 _pwcache_getpwnam = a_getpwnam; 550 _pwcache_getpwuid = a_getpwuid; 551 552 return (0); 553 } 554 555 int 556 pwcache_groupdb( 557 int (*a_setgroupent)(int), 558 void (*a_endgrent)(void), 559 struct group * (*a_getgrnam)(const char *), 560 struct group * (*a_getgrgid)(gid_t)) 561 { 562 int i; 563 564 /* a_setgroupent and a_endgrent may be NULL */ 565 if (a_getgrnam == NULL || a_getgrgid == NULL) 566 return (-1); 567 568 if (_pwcache_endgrent != NULL) 569 (*_pwcache_endgrent)(); 570 FLUSHTB(gidtb, GID_SZ, gidtb_fail); 571 FLUSHTB(grptb, GNM_SZ, grptb_fail); 572 gropn = 0; 573 _pwcache_setgroupent = a_setgroupent; 574 _pwcache_endgrent = a_endgrent; 575 _pwcache_getgrnam = a_getgrnam; 576 _pwcache_getgrgid = a_getgrgid; 577 578 return (0); 579 } 580 581 582 #ifdef TEST_PWCACHE 583 584 struct passwd * 585 test_getpwnam(const char *name) 586 { 587 static struct passwd foo; 588 589 memset(&foo, 0, sizeof(foo)); 590 if (strcmp(name, "toor") == 0) { 591 foo.pw_uid = 666; 592 return &foo; 593 } 594 return (getpwnam(name)); 595 } 596 597 int 598 main(int argc, char *argv[]) 599 { 600 uid_t u; 601 int r, i; 602 603 printf("pass 1 (default userdb)\n"); 604 for (i = 1; i < argc; i++) { 605 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 606 i, pwopn, usrtb_fail, usrtb); 607 r = uid_from_user(argv[i], &u); 608 if (r == -1) 609 printf(" uid_from_user %s: failed\n", argv[i]); 610 else 611 printf(" uid_from_user %s: %d\n", argv[i], u); 612 } 613 printf("pass 1 finish: pwopn %d usrtb_fail %d usrtb %p\n", 614 pwopn, usrtb_fail, usrtb); 615 616 puts(""); 617 printf("pass 2 (replacement userdb)\n"); 618 printf("pwcache_userdb returned %d\n", 619 pwcache_userdb(setpassent, test_getpwnam, getpwuid)); 620 printf("pwopn %d usrtb_fail %d usrtb %p\n", pwopn, usrtb_fail, usrtb); 621 622 for (i = 1; i < argc; i++) { 623 printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n", 624 i, pwopn, usrtb_fail, usrtb); 625 u = -1; 626 r = uid_from_user(argv[i], &u); 627 if (r == -1) 628 printf(" uid_from_user %s: failed\n", argv[i]); 629 else 630 printf(" uid_from_user %s: %d\n", argv[i], u); 631 } 632 printf("pass 2 finish: pwopn %d usrtb_fail %d usrtb %p\n", 633 pwopn, usrtb_fail, usrtb); 634 635 puts(""); 636 printf("pass 3 (null pointers)\n"); 637 printf("pwcache_userdb returned %d\n", 638 pwcache_userdb(NULL, NULL, NULL)); 639 640 return (0); 641 } 642 #endif /* TEST_PWCACHE */ 643 #endif /* !HAVE_PWCACHE_USERDB */ 644