contrib/sendmail-8.14/libsmdb/smdb.c

   1 /*
   2 ** Copyright (c) 1999-2002 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 #include <sm/gen.h>
  11 SM_RCSID("@(#)$Id: smdb.c,v 8.58 2004/08/03 20:58:38 ca Exp $")
  12
  13 #include <fcntl.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16
  17
  18 #include <sendmail/sendmail.h>
  19 #include <libsmdb/smdb.h>
  20
  21 static bool     smdb_lockfile __P((int, int));
  22
  23 /*
  24 ** SMDB_MALLOC_DATABASE -- Allocates a database structure.
  25 **
  26 **      Parameters:
  27 **              None
  28 **
  29 **      Returns:
  30 **              An pointer to an allocated SMDB_DATABASE structure or
  31 **              NULL if it couldn't allocate the memory.
  32 */
  33
  34 SMDB_DATABASE *
  35 smdb_malloc_database()
  36 {
  37         SMDB_DATABASE *db;
  38
  39         db = (SMDB_DATABASE *) malloc(sizeof(SMDB_DATABASE));
  40
  41         if (db != NULL)
  42                 (void) memset(db, '\0', sizeof(SMDB_DATABASE));
  43
  44         return db;
  45 }
  46
  47
  48 /*
  49 ** SMDB_FREE_DATABASE -- Unallocates a database structure.
  50 **
  51 **      Parameters:
  52 **              database -- a SMDB_DATABASE pointer to deallocate.
  53 **
  54 **      Returns:
  55 **              None
  56 */
  57
  58 void
  59 smdb_free_database(database)
  60         SMDB_DATABASE *database;
  61 {
  62         if (database != NULL)
  63                 free(database);
  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
  79 static bool
  80 smdb_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         (void) 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                 return true;
 107         save_errno = errno;
 108
 109         /*
 110         **  On SunOS, if you are testing using -oQ/tmp/mqueue or
 111         **  -oA/tmp/aliases or anything like that, and /tmp is mounted
 112         **  as type "tmp" (that is, served from swap space), the
 113         **  previous fcntl will fail with "Invalid argument" errors.
 114         **  Since this is fairly common during testing, we will assume
 115         **  that this indicates that the lock is successfully grabbed.
 116         */
 117
 118         if (save_errno == EINVAL)
 119                 return true;
 120
 121         if (!bitset(LOCK_NB, type) ||
 122             (save_errno != EACCES && save_errno != EAGAIN))
 123         {
 124 # if 0
 125                 int omode = fcntl(fd, F_GETFL, NULL);
 126                 int euid = (int) geteuid();
 127
 128                 syslog(LOG_ERR, "cannot lockf(%s%s, fd=%d, type=%o, omode=%o, euid=%d)",
 129                        filename, ext, fd, type, omode, euid);
 130 # endif /* 0 */
 131                 errno = save_errno;
 132                 return false;
 133         }
 134 #else /* !HASFLOCK */
 135
 136         while ((i = flock(fd, type)) < 0 && errno == EINTR)
 137                 continue;
 138         if (i >= 0)
 139                 return true;
 140         save_errno = errno;
 141
 142         if (!bitset(LOCK_NB, type) || save_errno != EWOULDBLOCK)
 143         {
 144 # if 0
 145                 int omode = fcntl(fd, F_GETFL, NULL);
 146                 int euid = (int) geteuid();
 147
 148                 syslog(LOG_ERR, "cannot flock(%s%s, fd=%d, type=%o, omode=%o, euid=%d)",
 149                        filename, ext, fd, type, omode, euid);
 150 # endif /* 0 */
 151                 errno = save_errno;
 152                 return false;
 153         }
 154 #endif /* !HASFLOCK */
 155         errno = save_errno;
 156         return false;
 157 }
 158 /*
 159 ** SMDB_OPEN_DATABASE -- Opens a database.
 160 **
 161 **      This opens a database. If type is SMDB_DEFAULT it tries to
 162 **      use a DB1 or DB2 hash. If that isn't available, it will try
 163 **      to use NDBM. If a specific type is given it will try to open
 164 **      a database of that type.
 165 **
 166 **      Parameters:
 167 **              database -- An pointer to a SMDB_DATABASE pointer where the
 168 **                         opened database will be stored. This should
 169 **                         be unallocated.
 170 **              db_name -- The name of the database to open. Do not include
 171 **                        the file name extension.
 172 **              mode -- The mode to set on the database file or files.
 173 **              mode_mask -- Mode bits that must match on an opened database.
 174 **              sff -- Flags to safefile.
 175 **              type -- The type of database to open. Supported types
 176 **                     vary depending on what was compiled in.
 177 **              user_info -- Information on the user to use for file
 178 **                          permissions.
 179 **              params -- Params specific to the database being opened.
 180 **                       Only supports some DB hash options right now
 181 **                       (see smdb_db_open() for details).
 182 **
 183 **      Returns:
 184 **              SMDBE_OK -- Success.
 185 **              Anything else is an error. Look up more info about the
 186 **              error in the comments for the specific open() used.
 187 */
 188
 189 int
 190 smdb_open_database(database, db_name, mode, mode_mask, sff, type, user_info,
 191                    params)
 192         SMDB_DATABASE **database;
 193         char *db_name;
 194         int mode;
 195         int mode_mask;
 196         long sff;
 197         SMDB_DBTYPE type;
 198         SMDB_USER_INFO *user_info;
 199         SMDB_DBPARAMS *params;
 200 {
 201         bool type_was_default = false;
 202
 203         if (type == SMDB_TYPE_DEFAULT)
 204         {
 205                 type_was_default = true;
 206 #ifdef NEWDB
 207                 type = SMDB_TYPE_HASH;
 208 #else /* NEWDB */
 209 # ifdef NDBM
 210                 type = SMDB_TYPE_NDBM;
 211 # endif /* NDBM */
 212 #endif /* NEWDB */
 213         }
 214
 215         if (type == SMDB_TYPE_DEFAULT)
 216                 return SMDBE_UNKNOWN_DB_TYPE;
 217
 218         if ((strncmp(type, SMDB_TYPE_HASH, SMDB_TYPE_HASH_LEN) == 0) ||
 219             (strncmp(type, SMDB_TYPE_BTREE, SMDB_TYPE_BTREE_LEN) == 0))
 220         {
 221 #ifdef NEWDB
 222                 int result;
 223
 224                 result = smdb_db_open(database, db_name, mode, mode_mask, sff,
 225                                       type, user_info, params);
 226 # ifdef NDBM
 227                 if (result == ENOENT && type_was_default)
 228                         type = SMDB_TYPE_NDBM;
 229                 else
 230 # endif /* NDBM */
 231                         return result;
 232 #else /* NEWDB */
 233                 return SMDBE_UNSUPPORTED_DB_TYPE;
 234 #endif /* NEWDB */
 235         }
 236
 237         if (strncmp(type, SMDB_TYPE_NDBM, SMDB_TYPE_NDBM_LEN) == 0)
 238         {
 239 #ifdef NDBM
 240                 int result;
 241
 242                 result = smdb_ndbm_open(database, db_name, mode, mode_mask,
 243                                         sff, type, user_info, params);
 244                 return result;
 245 #else /* NDBM */
 246                 return SMDBE_UNSUPPORTED_DB_TYPE;
 247 #endif /* NDBM */
 248         }
 249
 250         return SMDBE_UNKNOWN_DB_TYPE;
 251 }
 252 /*
 253 ** SMDB_ADD_EXTENSION -- Adds an extension to a file name.
 254 **
 255 **      Just adds a . followed by a string to a db_name if there
 256 **      is room and the db_name does not already have that extension.
 257 **
 258 **      Parameters:
 259 **              full_name -- The final file name.
 260 **              max_full_name_len -- The max length for full_name.
 261 **              db_name -- The name of the db.
 262 **              extension -- The extension to add.
 263 **
 264 **      Returns:
 265 **              SMDBE_OK -- Success.
 266 **              Anything else is an error. Look up more info about the
 267 **              error in the comments for the specific open() used.
 268 */
 269
 270 int
 271 smdb_add_extension(full_name, max_full_name_len, db_name, extension)
 272         char *full_name;
 273         int max_full_name_len;
 274         char *db_name;
 275         char *extension;
 276 {
 277         int extension_len;
 278         int db_name_len;
 279
 280         if (full_name == NULL || db_name == NULL || extension == NULL)
 281                 return SMDBE_INVALID_PARAMETER;
 282
 283         extension_len = strlen(extension);
 284         db_name_len = strlen(db_name);
 285
 286         if (extension_len + db_name_len + 2 > max_full_name_len)
 287                 return SMDBE_DB_NAME_TOO_LONG;
 288
 289         if (db_name_len < extension_len + 1 ||
 290             db_name[db_name_len - extension_len - 1] != '.' ||
 291             strcmp(&db_name[db_name_len - extension_len], extension) != 0)
 292                 (void) sm_snprintf(full_name, max_full_name_len, "%s.%s",
 293                                    db_name, extension);
 294         else
 295                 (void) sm_strlcpy(full_name, db_name, max_full_name_len);
 296
 297         return SMDBE_OK;
 298 }
 299 /*
 300 **  SMDB_LOCK_FILE -- Locks the database file.
 301 **
 302 **      Locks the actual database file.
 303 **
 304 **      Parameters:
 305 **              lock_fd -- The resulting descriptor for the locked file.
 306 **              db_name -- The name of the database without extension.
 307 **              mode -- The open mode.
 308 **              sff -- Flags to safefile.
 309 **              extension -- The extension for the file.
 310 **
 311 **      Returns:
 312 **              SMDBE_OK -- Success, otherwise errno.
 313 */
 314
 315 int
 316 smdb_lock_file(lock_fd, db_name, mode, sff, extension)
 317         int *lock_fd;
 318         char *db_name;
 319         int mode;
 320         long sff;
 321         char *extension;
 322 {
 323         int result;
 324         char file_name[MAXPATHLEN];
 325
 326         result = smdb_add_extension(file_name, sizeof file_name, db_name,
 327                                     extension);
 328         if (result != SMDBE_OK)
 329                 return result;
 330
 331         *lock_fd = safeopen(file_name, mode & ~O_TRUNC, DBMMODE, sff);
 332         if (*lock_fd < 0)
 333                 return errno;
 334
 335         return SMDBE_OK;
 336 }
 337 /*
 338 **  SMDB_UNLOCK_FILE -- Unlocks a file
 339 **
 340 **      Unlocks a file.
 341 **
 342 **      Parameters:
 343 **              lock_fd -- The descriptor for the locked file.
 344 **
 345 **      Returns:
 346 **              SMDBE_OK -- Success, otherwise errno.
 347 */
 348
 349 int
 350 smdb_unlock_file(lock_fd)
 351         int lock_fd;
 352 {
 353         int result;
 354
 355         result = close(lock_fd);
 356         if (result != 0)
 357                 return errno;
 358
 359         return SMDBE_OK;
 360 }
 361 /*
 362 **  SMDB_LOCK_MAP -- Locks a database.
 363 **
 364 **      Parameters:
 365 **              database -- database description.
 366 **              type -- type of the lock.  Bits can be:
 367 **                      LOCK_EX -- exclusive lock.
 368 **                      LOCK_NB -- non-blocking.
 369 **
 370 **      Returns:
 371 **              SMDBE_OK -- Success, otherwise errno.
 372 */
 373
 374 int
 375 smdb_lock_map(database, type)
 376         SMDB_DATABASE *database;
 377         int type;
 378 {
 379         int fd;
 380
 381         fd = database->smdb_lockfd(database);
 382         if (fd < 0)
 383                 return SMDBE_NOT_FOUND;
 384         if (!smdb_lockfile(fd, type))
 385                 return SMDBE_LOCK_NOT_GRANTED;
 386         return SMDBE_OK;
 387 }
 388 /*
 389 **  SMDB_UNLOCK_MAP -- Unlocks a database
 390 **
 391 **      Parameters:
 392 **              database -- database description.
 393 **
 394 **      Returns:
 395 **              SMDBE_OK -- Success, otherwise errno.
 396 */
 397
 398 int
 399 smdb_unlock_map(database)
 400         SMDB_DATABASE *database;
 401 {
 402         int fd;
 403
 404         fd = database->smdb_lockfd(database);
 405         if (fd < 0)
 406                 return SMDBE_NOT_FOUND;
 407         if (!smdb_lockfile(fd, LOCK_UN))
 408                 return SMDBE_LOCK_NOT_HELD;
 409         return SMDBE_OK;
 410 }
 411 /*
 412 **  SMDB_SETUP_FILE -- Gets db file ready for use.
 413 **
 414 **      Makes sure permissions on file are safe and creates it if it
 415 **      doesn't exist.
 416 **
 417 **      Parameters:
 418 **              db_name -- The name of the database without extension.
 419 **              extension -- The extension.
 420 **              sff -- Flags to safefile.
 421 **              mode_mask -- Mode bits that must match.
 422 **              user_info -- Information on the user to use for file
 423 **                          permissions.
 424 **              stat_info -- A place to put the stat info for the file.
 425 **      Returns:
 426 **              SMDBE_OK -- Success, otherwise errno.
 427 */
 428
 429 int
 430 smdb_setup_file(db_name, extension, mode_mask, sff, user_info, stat_info)
 431         char *db_name;
 432         char *extension;
 433         int mode_mask;
 434         long sff;
 435         SMDB_USER_INFO *user_info;
 436         struct stat *stat_info;
 437 {
 438         int st;
 439         int result;
 440         char db_file_name[MAXPATHLEN];
 441
 442         result = smdb_add_extension(db_file_name, sizeof db_file_name, db_name,
 443                                     extension);
 444         if (result != SMDBE_OK)
 445                 return result;
 446
 447         st = safefile(db_file_name, user_info->smdbu_id,
 448                       user_info->smdbu_group_id, user_info->smdbu_name,
 449                       sff, mode_mask, stat_info);
 450         if (st != 0)
 451                 return st;
 452
 453         return SMDBE_OK;
 454 }
 455 /*
 456 **  SMDB_FILECHANGED -- Checks to see if a file changed.
 457 **
 458 **      Compares the passed in stat_info with a current stat on
 459 **      the passed in file descriptor. Check filechanged for
 460 **      return values.
 461 **
 462 **      Parameters:
 463 **              db_name -- The name of the database without extension.
 464 **              extension -- The extension.
 465 **              db_fd -- A file descriptor for the database file.
 466 **              stat_info -- An old stat_info.
 467 **      Returns:
 468 **              SMDBE_OK -- Success, otherwise errno.
 469 */
 470
 471 int
 472 smdb_filechanged(db_name, extension, db_fd, stat_info)
 473         char *db_name;
 474         char *extension;
 475         int db_fd;
 476         struct stat *stat_info;
 477 {
 478         int result;
 479         char db_file_name[MAXPATHLEN];
 480
 481         result = smdb_add_extension(db_file_name, sizeof db_file_name, db_name,
 482                                     extension);
 483         if (result != SMDBE_OK)
 484                 return result;
 485         return filechanged(db_file_name, db_fd, stat_info);
 486 }
 487 /*
 488 ** SMDB_PRINT_AVAILABLE_TYPES -- Prints the names of the available types.
 489 **
 490 **      Parameters:
 491 **              None
 492 **
 493 **      Returns:
 494 **              None
 495 */
 496
 497 void
 498 smdb_print_available_types()
 499 {
 500 #ifdef NDBM
 501         printf("dbm\n");
 502 #endif /* NDBM */
 503 #ifdef NEWDB
 504         printf("hash\n");
 505         printf("btree\n");
 506 #endif /* NEWDB */
 507 }
 508 /*
 509 ** SMDB_DB_DEFINITION -- Given a database type, return database definition
 510 **
 511 **      Reads though a structure making an association with the database
 512 **      type and the required cpp define from sendmail/README.
 513 **      List size is dynamic and must be NULL terminated.
 514 **
 515 **      Parameters:
 516 **              type -- The name of the database type.
 517 **
 518 **      Returns:
 519 **              definition for type, otherwise NULL.
 520 */
 521
 522 typedef struct
 523 {
 524         SMDB_DBTYPE type;
 525         char *dbdef;
 526 } dbtype;
 527
 528 static dbtype DatabaseDefs[] =
 529 {
 530         { SMDB_TYPE_HASH,       "NEWDB" },
 531         { SMDB_TYPE_BTREE,      "NEWDB" },
 532         { SMDB_TYPE_NDBM,       "NDBM"  },
 533         { NULL,                 "OOPS"  }
 534 };
 535
 536 char *
 537 smdb_db_definition(type)
 538         SMDB_DBTYPE type;
 539 {
 540         dbtype *ptr = DatabaseDefs;
 541
 542         while (ptr != NULL && ptr->type != NULL)
 543         {
 544                 if (strcmp(type, ptr->type) == 0)
 545                         return ptr->dbdef;
 546                 ptr++;
 547         }
 548         return NULL;
 549 }