smdb.c revision 66494
1/* 2** Copyright (c) 1999-2000 Sendmail, Inc. and its suppliers. 3** All rights reserved. 4** 5** By using this file, you agree to the terms and conditions set 6** forth in the LICENSE file which can be found at the top level of 7** the sendmail distribution. 8*/ 9 10#ifndef lint 11static char id[] = "@(#)$Id: smdb.c,v 8.37.4.2 2000/08/24 17:08:00 gshapiro Exp $"; 12#endif /* ! lint */ 13 14#include <fcntl.h> 15#include <stdlib.h> 16#include <unistd.h> 17 18 19#include <sendmail/sendmail.h> 20#include <libsmdb/smdb.h> 21 22/* 23** SMDB_MALLOC_DATABASE -- Allocates a database structure. 24** 25** Parameters: 26** None 27** 28** Returns: 29** An pointer to an allocated SMDB_DATABASE structure or 30** NULL if it couldn't allocate the memory. 31*/ 32 33SMDB_DATABASE * 34smdb_malloc_database() 35{ 36 SMDB_DATABASE *db; 37 38 db = (SMDB_DATABASE *) malloc(sizeof(SMDB_DATABASE)); 39 40 if (db != NULL) 41 memset(db, '\0', sizeof(SMDB_DATABASE)); 42 43 return db; 44} 45 46 47/* 48** SMDB_FREE_DATABASE -- Unallocates a database structure. 49** 50** Parameters: 51** database -- a SMDB_DATABASE pointer to deallocate. 52** 53** Returns: 54** None 55*/ 56 57void 58smdb_free_database(database) 59 SMDB_DATABASE *database; 60{ 61 if (database != NULL) 62 free(database); 63} 64 65/* 66** SMDB_LOCKFILE -- lock a file using flock or (shudder) fcntl locking 67** 68** Parameters: 69** fd -- the file descriptor of the file. 70** type -- type of the lock. Bits can be: 71** LOCK_EX -- exclusive lock. 72** LOCK_NB -- non-blocking. 73** 74** Returns: 75** TRUE if the lock was acquired. 76** FALSE otherwise. 77*/ 78 79static bool 80smdb_lockfile(fd, type) 81 int fd; 82 int type; 83{ 84 int i; 85 int save_errno; 86#if !HASFLOCK 87 int action; 88 struct flock lfd; 89 90 memset(&lfd, '\0', sizeof lfd); 91 if (bitset(LOCK_UN, type)) 92 lfd.l_type = F_UNLCK; 93 else if (bitset(LOCK_EX, type)) 94 lfd.l_type = F_WRLCK; 95 else 96 lfd.l_type = F_RDLCK; 97 98 if (bitset(LOCK_NB, type)) 99 action = F_SETLK; 100 else 101 action = F_SETLKW; 102 103 while ((i = fcntl(fd, action, &lfd)) < 0 && errno == EINTR) 104 continue; 105 if (i >= 0) 106 { 107 return TRUE; 108 } 109 save_errno = errno; 110 111 /* 112 ** On SunOS, if you are testing using -oQ/tmp/mqueue or 113 ** -oA/tmp/aliases or anything like that, and /tmp is mounted 114 ** as type "tmp" (that is, served from swap space), the 115 ** previous fcntl will fail with "Invalid argument" errors. 116 ** Since this is fairly common during testing, we will assume 117 ** that this indicates that the lock is successfully grabbed. 118 */ 119 120 if (save_errno == EINVAL) 121 { 122 return TRUE; 123 } 124 125 if (!bitset(LOCK_NB, type) || 126 (save_errno != EACCES && save_errno != EAGAIN)) 127 { 128 int omode = -1; 129# ifdef F_GETFL 130 (void) fcntl(fd, F_GETFL, &omode); 131 errno = save_errno; 132# endif /* F_GETFL */ 133# if 0 134 syslog(LOG_ERR, "cannot lockf(%s%s, fd=%d, type=%o, omode=%o, euid=%d)", 135 filename, ext, fd, type, omode, geteuid()); 136# endif /* 0 */ 137 return FALSE; 138 } 139#else /* !HASFLOCK */ 140 141 while ((i = flock(fd, type)) < 0 && errno == EINTR) 142 continue; 143 if (i >= 0) 144 { 145 return TRUE; 146 } 147 save_errno = errno; 148 149 if (!bitset(LOCK_NB, type) || save_errno != EWOULDBLOCK) 150 { 151 int omode = -1; 152# ifdef F_GETFL 153 (void) fcntl(fd, F_GETFL, &omode); 154 errno = save_errno; 155# endif /* F_GETFL */ 156# if 0 157 syslog(LOG_ERR, "cannot flock(%s%s, fd=%d, type=%o, omode=%o, euid=%d)", 158 filename, ext, fd, type, omode, geteuid()); 159# endif /* 0 */ 160 return FALSE; 161 } 162#endif /* !HASFLOCK */ 163 errno = save_errno; 164 return FALSE; 165} 166 167/* 168** SMDB_OPEN_DATABASE -- Opens a database. 169** 170** This opens a database. If type is SMDB_DEFAULT it tries to 171** use a DB1 or DB2 hash. If that isn't available, it will try 172** to use NDBM. If a specific type is given it will try to open 173** a database of that type. 174** 175** Parameters: 176** database -- An pointer to a SMDB_DATABASE pointer where the 177** opened database will be stored. This should 178** be unallocated. 179** db_name -- The name of the database to open. Do not include 180** the file name extension. 181** mode -- The mode to set on the database file or files. 182** mode_mask -- Mode bits that must match on an opened database. 183** sff -- Flags to safefile. 184** type -- The type of database to open. Supported types 185** vary depending on what was compiled in. 186** user_info -- Information on the user to use for file 187** permissions. 188** params -- Params specific to the database being opened. 189** Only supports some DB hash options right now 190** (see smdb_db_open() for details). 191** 192** Returns: 193** SMDBE_OK -- Success. 194** Anything else is an error. Look up more info about the 195** error in the comments for the specific open() used. 196*/ 197 198int 199smdb_open_database(database, db_name, mode, mode_mask, sff, type, user_info, 200 params) 201 SMDB_DATABASE **database; 202 char *db_name; 203 int mode; 204 int mode_mask; 205 long sff; 206 SMDB_DBTYPE type; 207 SMDB_USER_INFO *user_info; 208 SMDB_DBPARAMS *params; 209{ 210 int result; 211 bool type_was_default = FALSE; 212 213 if (type == SMDB_TYPE_DEFAULT) 214 { 215 type_was_default = TRUE; 216#ifdef NEWDB 217 type = SMDB_TYPE_HASH; 218#else /* NEWDB */ 219# ifdef NDBM 220 type = SMDB_TYPE_NDBM; 221# endif /* NDBM */ 222#endif /* NEWDB */ 223 } 224 225 if (type == SMDB_TYPE_DEFAULT) 226 return SMDBE_UNKNOWN_DB_TYPE; 227 228 if ((strncmp(type, SMDB_TYPE_HASH, SMDB_TYPE_HASH_LEN) == 0) || 229 (strncmp(type, SMDB_TYPE_BTREE, SMDB_TYPE_BTREE_LEN) == 0)) 230 { 231#ifdef NEWDB 232 result = smdb_db_open(database, db_name, mode, mode_mask, sff, 233 type, user_info, params); 234# ifdef NDBM 235 if (result == ENOENT && type_was_default) 236 type = SMDB_TYPE_NDBM; 237 else 238# endif /* NDBM */ 239 return result; 240#else /* NEWDB */ 241 return SMDBE_UNSUPPORTED_DB_TYPE; 242#endif /* NEWDB */ 243 } 244 245 if (strncmp(type, SMDB_TYPE_NDBM, SMDB_TYPE_NDBM_LEN) == 0) 246 { 247#ifdef NDBM 248 result = smdb_ndbm_open(database, db_name, mode, mode_mask, 249 sff, type, user_info, params); 250 return result; 251#else /* NDBM */ 252 return SMDBE_UNSUPPORTED_DB_TYPE; 253#endif /* NDBM */ 254 } 255 256 return SMDBE_UNKNOWN_DB_TYPE; 257} 258 259/* 260** SMDB_ADD_EXTENSION -- Adds an extension to a file name. 261** 262** Just adds a . followed by a string to a db_name if there 263** is room and the db_name does not already have that extension. 264** 265** Parameters: 266** full_name -- The final file name. 267** max_full_name_len -- The max length for full_name. 268** db_name -- The name of the db. 269** extension -- The extension to add. 270** 271** Returns: 272** SMDBE_OK -- Success. 273** Anything else is an error. Look up more info about the 274** error in the comments for the specific open() used. 275*/ 276 277int 278smdb_add_extension(full_name, max_full_name_len, db_name, extension) 279 char *full_name; 280 int max_full_name_len; 281 char *db_name; 282 char *extension; 283{ 284 int extension_len; 285 int db_name_len; 286 287 if (full_name == NULL || db_name == NULL || extension == NULL) 288 return SMDBE_INVALID_PARAMETER; 289 290 extension_len = strlen(extension); 291 db_name_len = strlen(db_name); 292 293 if (extension_len + db_name_len + 2 > max_full_name_len) 294 return SMDBE_DB_NAME_TOO_LONG; 295 296 if (db_name_len < extension_len + 1 || 297 db_name[db_name_len - extension_len - 1] != '.' || 298 strcmp(&db_name[db_name_len - extension_len], extension) != 0) 299 snprintf(full_name, max_full_name_len, "%s.%s", db_name, 300 extension); 301 else 302 (void) strlcpy(full_name, db_name, max_full_name_len); 303 304 return SMDBE_OK; 305} 306 307/* 308** SMDB_LOCK_FILE -- Locks the database file. 309** 310** Locks the actual database file. 311** 312** Parameters: 313** lock_fd -- The resulting descriptor for the locked file. 314** db_name -- The name of the database without extension. 315** mode -- The open mode. 316** sff -- Flags to safefile. 317** extension -- The extension for the file. 318** 319** Returns: 320** SMDBE_OK -- Success, otherwise errno. 321*/ 322 323int 324smdb_lock_file(lock_fd, db_name, mode, sff, extension) 325 int *lock_fd; 326 char *db_name; 327 int mode; 328 long sff; 329 char *extension; 330{ 331 int result; 332 char file_name[SMDB_MAX_NAME_LEN]; 333 334 result = smdb_add_extension(file_name, SMDB_MAX_NAME_LEN, db_name, 335 extension); 336 if (result != SMDBE_OK) 337 return result; 338 339 *lock_fd = safeopen(file_name, mode & ~O_TRUNC, 0644, sff); 340 if (*lock_fd < 0) 341 return errno; 342 343 return SMDBE_OK; 344} 345 346/* 347** SMDB_UNLOCK_FILE -- Unlocks a file 348** 349** Unlocks a file. 350** 351** Parameters: 352** lock_fd -- The descriptor for the locked file. 353** 354** Returns: 355** SMDBE_OK -- Success, otherwise errno. 356*/ 357 358int 359smdb_unlock_file(lock_fd) 360 int lock_fd; 361{ 362 int result; 363 364 result = close(lock_fd); 365 if (result != 0) 366 return errno; 367 368 return SMDBE_OK; 369} 370 371/* 372** SMDB_LOCK_MAP -- Locks a database. 373** 374** Parameters: 375** database -- database description. 376** type -- type of the lock. Bits can be: 377** LOCK_EX -- exclusive lock. 378** LOCK_NB -- non-blocking. 379** 380** Returns: 381** SMDBE_OK -- Success, otherwise errno. 382*/ 383 384int 385smdb_lock_map(database, type) 386 SMDB_DATABASE *database; 387 int type; 388{ 389 int fd; 390 391 fd = database->smdb_lockfd(database); 392 if (fd < 0) 393 return SMDBE_NOT_FOUND; 394 if (!smdb_lockfile(fd, type)) 395 return SMDBE_LOCK_NOT_GRANTED; 396 return SMDBE_OK; 397} 398 399/* 400** SMDB_UNLOCK_MAP -- Unlocks a database 401** 402** Parameters: 403** database -- database description. 404** 405** Returns: 406** SMDBE_OK -- Success, otherwise errno. 407*/ 408 409int 410smdb_unlock_map(database) 411 SMDB_DATABASE *database; 412{ 413 int fd; 414 415 fd = database->smdb_lockfd(database); 416 if (fd < 0) 417 return SMDBE_NOT_FOUND; 418 if (!smdb_lockfile(fd, LOCK_UN)) 419 return SMDBE_LOCK_NOT_HELD; 420 return SMDBE_OK; 421} 422 423 424/* 425** SMDB_SETUP_FILE -- Gets db file ready for use. 426** 427** Makes sure permissions on file are safe and creates it if it 428** doesn't exist. 429** 430** Parameters: 431** db_name -- The name of the database without extension. 432** extension -- The extension. 433** sff -- Flags to safefile. 434** mode_mask -- Mode bits that must match. 435** user_info -- Information on the user to use for file 436** permissions. 437** stat_info -- A place to put the stat info for the file. 438** Returns: 439** SMDBE_OK -- Success, otherwise errno. 440*/ 441 442int 443smdb_setup_file(db_name, extension, mode_mask, sff, user_info, stat_info) 444 char *db_name; 445 char *extension; 446 int mode_mask; 447 long sff; 448 SMDB_USER_INFO *user_info; 449 struct stat *stat_info; 450{ 451 int st; 452 int result; 453 char db_file_name[SMDB_MAX_NAME_LEN]; 454 455 result = smdb_add_extension(db_file_name, SMDB_MAX_NAME_LEN, db_name, 456 extension); 457 if (result != SMDBE_OK) 458 return result; 459 460 st = safefile(db_file_name, user_info->smdbu_id, 461 user_info->smdbu_group_id, user_info->smdbu_name, 462 sff, mode_mask, stat_info); 463 if (st != 0) 464 return st; 465 466 return SMDBE_OK; 467} 468 469/* 470** SMDB_FILECHANGED -- Checks to see if a file changed. 471** 472** Compares the passed in stat_info with a current stat on 473** the passed in file descriptor. Check filechanged for 474** return values. 475** 476** Parameters: 477** db_name -- The name of the database without extension. 478** extension -- The extension. 479** db_fd -- A file descriptor for the database file. 480** stat_info -- An old stat_info. 481** Returns: 482** SMDBE_OK -- Success, otherwise errno. 483*/ 484 485int 486smdb_filechanged(db_name, extension, db_fd, stat_info) 487 char *db_name; 488 char *extension; 489 int db_fd; 490 struct stat *stat_info; 491{ 492 int result; 493 char db_file_name[SMDB_MAX_NAME_LEN]; 494 495 result = smdb_add_extension(db_file_name, SMDB_MAX_NAME_LEN, db_name, 496 extension); 497 if (result != SMDBE_OK) 498 return result; 499 500 result = filechanged(db_file_name, db_fd, stat_info); 501 502 return result; 503} 504/* 505** SMDB_PRINT_AVAILABLE_TYPES -- Prints the names of the available types. 506** 507** Parameters: 508** None 509** 510** Returns: 511** None 512*/ 513 514void 515smdb_print_available_types() 516{ 517#ifdef NDBM 518 printf("dbm\n"); 519#endif /* NDBM */ 520#ifdef NEWDB 521 printf("hash\n"); 522 printf("btree\n"); 523#endif /* NEWDB */ 524} 525/* 526** SMDB_DB_DEFINITION -- Given a database type, return database definition 527** 528** Reads though a structure making an association with the database 529** type and the required cpp define from sendmail/README. 530** List size is dynamic and must be NULL terminated. 531** 532** Parameters: 533** type -- The name of the database type. 534** 535** Returns: 536** definition for type, otherwise NULL. 537*/ 538 539typedef struct 540{ 541 SMDB_DBTYPE type; 542 char *dbdef; 543} dbtype; 544 545static dbtype DatabaseDefs[] = 546{ 547 { SMDB_TYPE_HASH, "NEWDB" }, 548 { SMDB_TYPE_BTREE, "NEWDB" }, 549 { SMDB_TYPE_NDBM, "NDBM" }, 550 { NULL, "OOPS" } 551}; 552 553char * 554smdb_db_definition(type) 555 SMDB_DBTYPE type; 556{ 557 dbtype *ptr = DatabaseDefs; 558 559 while (ptr != NULL && ptr->type != NULL) 560 { 561 if (strcmp(type, ptr->type) == 0) 562 return ptr->dbdef; 563 ptr++; 564 } 565 return NULL; 566} 567