granicus.if.org Git - postgresql/blob - src/backend/utils/init/miscinit.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * miscinit.c
   4  *        miscellaneous initialization support stuff
   5  *
   6  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        $PostgreSQL: pgsql/src/backend/utils/init/miscinit.c,v 1.129 2004/07/12 00:09:06 momjian Exp $
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15 #include "postgres.h"
  16
  17 #include <sys/param.h>
  18 #include <signal.h>
  19 #include <sys/file.h>
  20 #include <sys/stat.h>
  21 #include <sys/time.h>
  22 #include <fcntl.h>
  23 #include <unistd.h>
  24 #include <grp.h>
  25 #include <pwd.h>
  26 #include <netinet/in.h>
  27 #include <arpa/inet.h>
  28 #ifdef HAVE_UTIME_H
  29 #include <utime.h>
  30 #endif
  31
  32 #include "catalog/catname.h"
  33 #include "catalog/pg_shadow.h"
  34 #include "libpq/libpq-be.h"
  35 #include "miscadmin.h"
  36 #include "storage/fd.h"
  37 #include "storage/ipc.h"
  38 #include "storage/pg_shmem.h"
  39 #include "utils/builtins.h"
  40 #include "utils/guc.h"
  41 #include "utils/lsyscache.h"
  42 #include "utils/syscache.h"
  43
  44
  45 ProcessingMode Mode = InitProcessing;
  46
  47 /* Note: we rely on these to initialize as zeroes */
  48 static char directoryLockFile[MAXPGPATH];
  49 static char socketLockFile[MAXPGPATH];
  50
  51
  52 /* ----------------------------------------------------------------
  53  *              ignoring system indexes support stuff
  54  *
  55  * NOTE: "ignoring system indexes" means we do not use the system indexes
  56  * for lookups (either in hardwired catalog accesses or in planner-generated
  57  * plans).  We do, however, still update the indexes when a catalog
  58  * modification is made.
  59  * ----------------------------------------------------------------
  60  */
  61
  62 static bool isIgnoringSystemIndexes = false;
  63
  64 /*
  65  * IsIgnoringSystemIndexes
  66  *              True if ignoring system indexes.
  67  */
  68 bool
  69 IsIgnoringSystemIndexes(void)
  70 {
  71         return isIgnoringSystemIndexes;
  72 }
  73
  74 /*
  75  * IgnoreSystemIndexes
  76  *              Set true or false whether PostgreSQL ignores system indexes.
  77  */
  78 void
  79 IgnoreSystemIndexes(bool mode)
  80 {
  81         isIgnoringSystemIndexes = mode;
  82 }
  83
  84 /* ----------------------------------------------------------------
  85  *              system index reindexing support
  86  *
  87  * When we are busy reindexing a system index, this code provides support
  88  * for preventing catalog lookups from using that index.
  89  * ----------------------------------------------------------------
  90  */
  91
  92 static Oid      currentlyReindexedHeap = InvalidOid;
  93 static Oid      currentlyReindexedIndex = InvalidOid;
  94
  95 /*
  96  * ReindexIsProcessingHeap
  97  *              True if heap specified by OID is currently being reindexed.
  98  */
  99 bool
 100 ReindexIsProcessingHeap(Oid heapOid)
 101 {
 102         return heapOid == currentlyReindexedHeap;
 103 }
 104
 105 /*
 106  * ReindexIsProcessingIndex
 107  *              True if index specified by OID is currently being reindexed.
 108  */
 109 bool
 110 ReindexIsProcessingIndex(Oid indexOid)
 111 {
 112         return indexOid == currentlyReindexedIndex;
 113 }
 114
 115 /*
 116  * SetReindexProcessing
 117  *              Set flag that specified heap/index are being reindexed.
 118  *              Pass InvalidOid to indicate that reindexing is not active.
 119  */
 120 void
 121 SetReindexProcessing(Oid heapOid, Oid indexOid)
 122 {
 123         /* Args should be both, or neither, InvalidOid */
 124         Assert((heapOid == InvalidOid) == (indexOid == InvalidOid));
 125         /* Reindexing is not re-entrant. */
 126         Assert(indexOid == InvalidOid || currentlyReindexedIndex == InvalidOid);
 127         currentlyReindexedHeap = heapOid;
 128         currentlyReindexedIndex = indexOid;
 129 }
 130
 131 /* ----------------------------------------------------------------
 132  *                              database path / name support stuff
 133  * ----------------------------------------------------------------
 134  */
 135
 136 void
 137 SetDatabasePath(const char *path)
 138 {
 139         if (DatabasePath)
 140         {
 141                 free(DatabasePath);
 142                 DatabasePath = NULL;
 143         }
 144         /* use strdup since this is done before memory contexts are set up */
 145         if (path)
 146         {
 147                 DatabasePath = strdup(path);
 148                 AssertState(DatabasePath);
 149         }
 150 }
 151
 152 /*
 153  * Set data directory, but make sure it's an absolute path.  Use this,
 154  * never set DataDir directly.
 155  */
 156 void
 157 SetDataDir(const char *dir)
 158 {
 159         char       *new;
 160
 161         AssertArg(dir);
 162
 163         /* If presented path is relative, convert to absolute */
 164         if (!is_absolute_path(dir))
 165         {
 166                 char       *buf;
 167                 size_t          buflen;
 168
 169                 buflen = MAXPGPATH;
 170                 for (;;)
 171                 {
 172                         buf = malloc(buflen);
 173                         if (!buf)
 174                                 ereport(FATAL,
 175                                                 (errcode(ERRCODE_OUT_OF_MEMORY),
 176                                                  errmsg("out of memory")));
 177
 178                         if (getcwd(buf, buflen))
 179                                 break;
 180                         else if (errno == ERANGE)
 181                         {
 182                                 free(buf);
 183                                 buflen *= 2;
 184                                 continue;
 185                         }
 186                         else
 187                         {
 188                                 free(buf);
 189                                 elog(FATAL, "could not get current working directory: %m");
 190                         }
 191                 }
 192
 193                 new = malloc(strlen(buf) + 1 + strlen(dir) + 1);
 194                 if (!new)
 195                         ereport(FATAL,
 196                                         (errcode(ERRCODE_OUT_OF_MEMORY),
 197                                          errmsg("out of memory")));
 198                 sprintf(new, "%s/%s", buf, dir);
 199                 free(buf);
 200         }
 201         else
 202         {
 203                 new = strdup(dir);
 204                 if (!new)
 205                         ereport(FATAL,
 206                                         (errcode(ERRCODE_OUT_OF_MEMORY),
 207                                          errmsg("out of memory")));
 208         }
 209
 210         canonicalize_path(new);
 211
 212         if (DataDir)
 213                 free(DataDir);
 214         DataDir = new;
 215 }
 216
 217
 218 /* ----------------------------------------------------------------
 219  *      User ID things
 220  *
 221  * The authenticated user is determined at connection start and never
 222  * changes.  The session user can be changed only by SET SESSION
 223  * AUTHORIZATION.  The current user may change when "setuid" functions
 224  * are implemented.  Conceptually there is a stack, whose bottom
 225  * is the session user.  You are yourself responsible to save and
 226  * restore the current user id if you need to change it.
 227  * ----------------------------------------------------------------
 228  */
 229 static AclId AuthenticatedUserId = 0;
 230 static AclId SessionUserId = 0;
 231 static AclId CurrentUserId = 0;
 232
 233 static bool AuthenticatedUserIsSuperuser = false;
 234
 235 /*
 236  * This function is relevant for all privilege checks.
 237  */
 238 AclId
 239 GetUserId(void)
 240 {
 241         AssertState(AclIdIsValid(CurrentUserId));
 242         return CurrentUserId;
 243 }
 244
 245
 246 void
 247 SetUserId(AclId newid)
 248 {
 249         AssertArg(AclIdIsValid(newid));
 250         CurrentUserId = newid;
 251 }
 252
 253
 254 /*
 255  * This value is only relevant for informational purposes.
 256  */
 257 AclId
 258 GetSessionUserId(void)
 259 {
 260         AssertState(AclIdIsValid(SessionUserId));
 261         return SessionUserId;
 262 }
 263
 264
 265 void
 266 SetSessionUserId(AclId newid)
 267 {
 268         AssertArg(AclIdIsValid(newid));
 269         SessionUserId = newid;
 270         /* Current user defaults to session user. */
 271         if (!AclIdIsValid(CurrentUserId))
 272                 CurrentUserId = newid;
 273 }
 274
 275
 276 void
 277 InitializeSessionUserId(const char *username)
 278 {
 279         HeapTuple       userTup;
 280         Datum           datum;
 281         bool            isnull;
 282         AclId           usesysid;
 283
 284         /*
 285          * Don't do scans if we're bootstrapping, none of the system catalogs
 286          * exist yet, and they should be owned by postgres anyway.
 287          */
 288         AssertState(!IsBootstrapProcessingMode());
 289
 290         /* call only once */
 291         AssertState(!OidIsValid(AuthenticatedUserId));
 292
 293         userTup = SearchSysCache(SHADOWNAME,
 294                                                          PointerGetDatum(username),
 295                                                          0, 0, 0);
 296         if (!HeapTupleIsValid(userTup))
 297                 ereport(FATAL,
 298                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
 299                                  errmsg("user \"%s\" does not exist", username)));
 300
 301         usesysid = ((Form_pg_shadow) GETSTRUCT(userTup))->usesysid;
 302
 303         AuthenticatedUserId = usesysid;
 304         AuthenticatedUserIsSuperuser = ((Form_pg_shadow) GETSTRUCT(userTup))->usesuper;
 305
 306         SetSessionUserId(usesysid); /* sets CurrentUserId too */
 307
 308         /* Record username and superuser status as GUC settings too */
 309         SetConfigOption("session_authorization", username,
 310                                         PGC_BACKEND, PGC_S_OVERRIDE);
 311         SetConfigOption("is_superuser",
 312                                         AuthenticatedUserIsSuperuser ? "on" : "off",
 313                                         PGC_INTERNAL, PGC_S_OVERRIDE);
 314
 315         /*
 316          * Set up user-specific configuration variables.  This is a good place
 317          * to do it so we don't have to read pg_shadow twice during session
 318          * startup.
 319          */
 320         datum = SysCacheGetAttr(SHADOWNAME, userTup,
 321                                                         Anum_pg_shadow_useconfig, &isnull);
 322         if (!isnull)
 323         {
 324                 ArrayType  *a = DatumGetArrayTypeP(datum);
 325
 326                 ProcessGUCArray(a, PGC_S_USER);
 327         }
 328
 329         ReleaseSysCache(userTup);
 330 }
 331
 332
 333 void
 334 InitializeSessionUserIdStandalone(void)
 335 {
 336         /* This function should only be called in a single-user backend. */
 337         AssertState(!IsUnderPostmaster);
 338
 339         /* call only once */
 340         AssertState(!OidIsValid(AuthenticatedUserId));
 341
 342         AuthenticatedUserId = BOOTSTRAP_USESYSID;
 343         AuthenticatedUserIsSuperuser = true;
 344
 345         SetSessionUserId(BOOTSTRAP_USESYSID);
 346 }
 347
 348
 349 /*
 350  * Change session auth ID while running
 351  *
 352  * Only a superuser may set auth ID to something other than himself.  Note
 353  * that in case of multiple SETs in a single session, the original userid's
 354  * superuserness is what matters.  But we set the GUC variable is_superuser
 355  * to indicate whether the *current* session userid is a superuser.
 356  */
 357 void
 358 SetSessionAuthorization(AclId userid, bool is_superuser)
 359 {
 360         /* Must have authenticated already, else can't make permission check */
 361         AssertState(AclIdIsValid(AuthenticatedUserId));
 362
 363         if (userid != AuthenticatedUserId &&
 364                 !AuthenticatedUserIsSuperuser)
 365                 ereport(ERROR,
 366                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 367                           errmsg("permission denied to set session authorization")));
 368
 369         SetSessionUserId(userid);
 370         SetUserId(userid);
 371
 372         SetConfigOption("is_superuser",
 373                                         is_superuser ? "on" : "off",
 374                                         PGC_INTERNAL, PGC_S_OVERRIDE);
 375 }
 376
 377
 378 /*
 379  * Get user name from user id
 380  */
 381 char *
 382 GetUserNameFromId(AclId userid)
 383 {
 384         HeapTuple       tuple;
 385         char       *result;
 386
 387         tuple = SearchSysCache(SHADOWSYSID,
 388                                                    ObjectIdGetDatum(userid),
 389                                                    0, 0, 0);
 390         if (!HeapTupleIsValid(tuple))
 391                 ereport(ERROR,
 392                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
 393                                  errmsg("invalid user ID: %d", userid)));
 394
 395         result = pstrdup(NameStr(((Form_pg_shadow) GETSTRUCT(tuple))->usename));
 396
 397         ReleaseSysCache(tuple);
 398         return result;
 399 }
 400
 401
 402
 403 /*-------------------------------------------------------------------------
 404  *                              Interlock-file support
 405  *
 406  * These routines are used to create both a data-directory lockfile
 407  * ($DATADIR/postmaster.pid) and a Unix-socket-file lockfile ($SOCKFILE.lock).
 408  * Both kinds of files contain the same info:
 409  *
 410  *              Owning process' PID
 411  *              Data directory path
 412  *
 413  * By convention, the owning process' PID is negated if it is a standalone
 414  * backend rather than a postmaster.  This is just for informational purposes.
 415  * The path is also just for informational purposes (so that a socket lockfile
 416  * can be more easily traced to the associated postmaster).
 417  *
 418  * A data-directory lockfile can optionally contain a third line, containing
 419  * the key and ID for the shared memory block used by this postmaster.
 420  *
 421  * On successful lockfile creation, a proc_exit callback to remove the
 422  * lockfile is automatically created.
 423  *-------------------------------------------------------------------------
 424  */
 425
 426 /*
 427  * proc_exit callback to remove a lockfile.
 428  */
 429 static void
 430 UnlinkLockFile(int status, Datum filename)
 431 {
 432         char       *fname = (char *) DatumGetPointer(filename);
 433
 434         if (fname != NULL)
 435         {
 436                 if (unlink(fname) != 0)
 437                 {
 438                         /* Should we complain if the unlink fails? */
 439                 }
 440                 free(fname);
 441         }
 442 }
 443
 444 /*
 445  * Create a lockfile.
 446  *
 447  * filename is the name of the lockfile to create.
 448  * amPostmaster is used to determine how to encode the output PID.
 449  * isDDLock and refName are used to determine what error message to produce.
 450  */
 451 static void
 452 CreateLockFile(const char *filename, bool amPostmaster,
 453                            bool isDDLock, const char *refName)
 454 {
 455         int                     fd;
 456         char            buffer[MAXPGPATH + 100];
 457         int                     ntries;
 458         int                     len;
 459         int                     encoded_pid;
 460         pid_t           other_pid;
 461         pid_t           my_pid = getpid();
 462
 463         /*
 464          * We need a loop here because of race conditions.      But don't loop
 465          * forever (for example, a non-writable $PGDATA directory might cause
 466          * a failure that won't go away).  100 tries seems like plenty.
 467          */
 468         for (ntries = 0;; ntries++)
 469         {
 470                 /*
 471                  * Try to create the lock file --- O_EXCL makes this atomic.
 472                  */
 473                 fd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
 474                 if (fd >= 0)
 475                         break;                          /* Success; exit the retry loop */
 476
 477                 /*
 478                  * Couldn't create the pid file. Probably it already exists.
 479                  */
 480                 if ((errno != EEXIST && errno != EACCES) || ntries > 100)
 481                         ereport(FATAL,
 482                                         (errcode_for_file_access(),
 483                                          errmsg("could not create lock file \"%s\": %m",
 484                                                         filename)));
 485
 486                 /*
 487                  * Read the file to get the old owner's PID.  Note race condition
 488                  * here: file might have been deleted since we tried to create it.
 489                  */
 490                 fd = open(filename, O_RDONLY, 0600);
 491                 if (fd < 0)
 492                 {
 493                         if (errno == ENOENT)
 494                                 continue;               /* race condition; try again */
 495                         ereport(FATAL,
 496                                         (errcode_for_file_access(),
 497                                          errmsg("could not open lock file \"%s\": %m",
 498                                                         filename)));
 499                 }
 500                 if ((len = read(fd, buffer, sizeof(buffer) - 1)) < 0)
 501                         ereport(FATAL,
 502                                         (errcode_for_file_access(),
 503                                          errmsg("could not read lock file \"%s\": %m",
 504                                                         filename)));
 505                 close(fd);
 506
 507                 buffer[len] = '\0';
 508                 encoded_pid = atoi(buffer);
 509
 510                 /* if pid < 0, the pid is for postgres, not postmaster */
 511                 other_pid = (pid_t) (encoded_pid < 0 ? -encoded_pid : encoded_pid);
 512
 513                 if (other_pid <= 0)
 514                         elog(FATAL, "bogus data in lock file \"%s\"", filename);
 515
 516                 /*
 517                  * Check to see if the other process still exists
 518                  *
 519                  * Normally kill() will fail with ESRCH if the given PID doesn't
 520                  * exist.  BeOS returns EINVAL for some silly reason, however.
 521                  */
 522                 if (other_pid != my_pid)
 523                 {
 524                         if (kill(other_pid, 0) == 0 ||
 525                                 (errno != ESRCH
 526 #ifdef __BEOS__
 527                                  && errno != EINVAL
 528 #endif
 529                                  ))
 530                         {
 531                                 /* lockfile belongs to a live process */
 532                                 ereport(FATAL,
 533                                                 (errcode(ERRCODE_LOCK_FILE_EXISTS),
 534                                                  errmsg("lock file \"%s\" already exists",
 535                                                                 filename),
 536                                                  isDDLock ?
 537                                          errhint("Is another %s (PID %d) running in data directory \"%s\"?",
 538                                                    (encoded_pid < 0 ? "postgres" : "postmaster"),
 539                                                          (int) other_pid, refName) :
 540                                                  errhint("Is another %s (PID %d) using socket file \"%s\"?",
 541                                                    (encoded_pid < 0 ? "postgres" : "postmaster"),
 542                                                                  (int) other_pid, refName)));
 543                         }
 544                 }
 545
 546                 /*
 547                  * No, the creating process did not exist.      However, it could be
 548                  * that the postmaster crashed (or more likely was kill -9'd by a
 549                  * clueless admin) but has left orphan backends behind.  Check for
 550                  * this by looking to see if there is an associated shmem segment
 551                  * that is still in use.
 552                  */
 553                 if (isDDLock)
 554                 {
 555                         char       *ptr;
 556                         unsigned long id1,
 557                                                 id2;
 558
 559                         ptr = strchr(buffer, '\n');
 560                         if (ptr != NULL &&
 561                                 (ptr = strchr(ptr + 1, '\n')) != NULL)
 562                         {
 563                                 ptr++;
 564                                 if (sscanf(ptr, "%lu %lu", &id1, &id2) == 2)
 565                                 {
 566                                         if (PGSharedMemoryIsInUse(id1, id2))
 567                                                 ereport(FATAL,
 568                                                                 (errcode(ERRCODE_LOCK_FILE_EXISTS),
 569                                                            errmsg("pre-existing shared memory block "
 570                                                                           "(key %lu, ID %lu) is still in use",
 571                                                                           id1, id2),
 572                                                            errhint("If you're sure there are no old "
 573                                                                            "server processes still running, remove "
 574                                                                            "the shared memory block with "
 575                                                                            "the command \"ipcrm\", or just delete the file \"%s\".",
 576                                                                            filename)));
 577                                 }
 578                         }
 579                 }
 580
 581                 /*
 582                  * Looks like nobody's home.  Unlink the file and try again to
 583                  * create it.  Need a loop because of possible race condition
 584                  * against other would-be creators.
 585                  */
 586                 if (unlink(filename) < 0)
 587                         ereport(FATAL,
 588                                         (errcode_for_file_access(),
 589                                          errmsg("could not remove old lock file \"%s\": %m",
 590                                                         filename),
 591                                          errhint("The file seems accidentally left over, but "
 592                                                   "it could not be removed. Please remove the file "
 593                                                          "by hand and try again.")));
 594         }
 595
 596         /*
 597          * Successfully created the file, now fill it.
 598          */
 599         snprintf(buffer, sizeof(buffer), "%d\n%s\n",
 600                          amPostmaster ? (int) my_pid : -((int) my_pid),
 601                          DataDir);
 602         errno = 0;
 603         if (write(fd, buffer, strlen(buffer)) != strlen(buffer))
 604         {
 605                 int                     save_errno = errno;
 606
 607                 close(fd);
 608                 unlink(filename);
 609                 /* if write didn't set errno, assume problem is no disk space */
 610                 errno = save_errno ? save_errno : ENOSPC;
 611                 ereport(FATAL,
 612                                 (errcode_for_file_access(),
 613                           errmsg("could not write lock file \"%s\": %m", filename)));
 614         }
 615         if (close(fd))
 616         {
 617                 int                     save_errno = errno;
 618
 619                 unlink(filename);
 620                 errno = save_errno;
 621                 ereport(FATAL,
 622                                 (errcode_for_file_access(),
 623                           errmsg("could not write lock file \"%s\": %m", filename)));
 624         }
 625
 626         /*
 627          * Arrange for automatic removal of lockfile at proc_exit.
 628          */
 629         on_proc_exit(UnlinkLockFile, PointerGetDatum(strdup(filename)));
 630 }
 631
 632 void
 633 CreateDataDirLockFile(const char *datadir, bool amPostmaster)
 634 {
 635         char            lockfile[MAXPGPATH];
 636
 637         snprintf(lockfile, sizeof(lockfile), "%s/postmaster.pid", datadir);
 638         CreateLockFile(lockfile, amPostmaster, true, datadir);
 639         /* Save name of lockfile for RecordSharedMemoryInLockFile */
 640         strcpy(directoryLockFile, lockfile);
 641 }
 642
 643 void
 644 CreateSocketLockFile(const char *socketfile, bool amPostmaster)
 645 {
 646         char            lockfile[MAXPGPATH];
 647
 648         snprintf(lockfile, sizeof(lockfile), "%s.lock", socketfile);
 649         CreateLockFile(lockfile, amPostmaster, false, socketfile);
 650         /* Save name of lockfile for TouchSocketLockFile */
 651         strcpy(socketLockFile, lockfile);
 652 }
 653
 654 /*
 655  * TouchSocketLockFile -- mark socket lock file as recently accessed
 656  *
 657  * This routine should be called every so often to ensure that the lock file
 658  * has a recent mod or access date.  That saves it
 659  * from being removed by overenthusiastic /tmp-directory-cleaner daemons.
 660  * (Another reason we should never have put the socket file in /tmp...)
 661  */
 662 void
 663 TouchSocketLockFile(void)
 664 {
 665         /* Do nothing if we did not create a socket... */
 666         if (socketLockFile[0] != '\0')
 667         {
 668                 /*
 669                  * utime() is POSIX standard, utimes() is a common alternative; if
 670                  * we have neither, fall back to actually reading the file (which
 671                  * only sets the access time not mod time, but that should be
 672                  * enough in most cases).  In all paths, we ignore errors.
 673                  */
 674 #ifdef HAVE_UTIME
 675                 utime(socketLockFile, NULL);
 676 #else                                                   /* !HAVE_UTIME */
 677 #ifdef HAVE_UTIMES
 678                 utimes(socketLockFile, NULL);
 679 #else                                                   /* !HAVE_UTIMES */
 680                 int                     fd;
 681                 char            buffer[1];
 682
 683                 fd = open(socketLockFile, O_RDONLY | PG_BINARY, 0);
 684                 if (fd >= 0)
 685                 {
 686                         read(fd, buffer, sizeof(buffer));
 687                         close(fd);
 688                 }
 689 #endif   /* HAVE_UTIMES */
 690 #endif   /* HAVE_UTIME */
 691         }
 692 }
 693
 694 /*
 695  * Append information about a shared memory segment to the data directory
 696  * lock file (if we have created one).
 697  *
 698  * This may be called multiple times in the life of a postmaster, if we
 699  * delete and recreate shmem due to backend crash.      Therefore, be prepared
 700  * to overwrite existing information.  (As of 7.1, a postmaster only creates
 701  * one shm seg at a time; but for the purposes here, if we did have more than
 702  * one then any one of them would do anyway.)
 703  */
 704 void
 705 RecordSharedMemoryInLockFile(unsigned long id1, unsigned long id2)
 706 {
 707         int                     fd;
 708         int                     len;
 709         char       *ptr;
 710         char            buffer[BLCKSZ];
 711
 712         /*
 713          * Do nothing if we did not create a lockfile (probably because we are
 714          * running standalone).
 715          */
 716         if (directoryLockFile[0] == '\0')
 717                 return;
 718
 719         fd = open(directoryLockFile, O_RDWR | PG_BINARY, 0);
 720         if (fd < 0)
 721         {
 722                 ereport(LOG,
 723                                 (errcode_for_file_access(),
 724                                  errmsg("could not open file \"%s\": %m",
 725                                                 directoryLockFile)));
 726                 return;
 727         }
 728         len = read(fd, buffer, sizeof(buffer) - 100);
 729         if (len < 0)
 730         {
 731                 ereport(LOG,
 732                                 (errcode_for_file_access(),
 733                                  errmsg("could not read from file \"%s\": %m",
 734                                                 directoryLockFile)));
 735                 close(fd);
 736                 return;
 737         }
 738         buffer[len] = '\0';
 739
 740         /*
 741          * Skip over first two lines (PID and path).
 742          */
 743         ptr = strchr(buffer, '\n');
 744         if (ptr == NULL ||
 745                 (ptr = strchr(ptr + 1, '\n')) == NULL)
 746         {
 747                 elog(LOG, "bogus data in \"%s\"", directoryLockFile);
 748                 close(fd);
 749                 return;
 750         }
 751         ptr++;
 752
 753         /*
 754          * Append key information.      Format to try to keep it the same length
 755          * always (trailing junk won't hurt, but might confuse humans).
 756          */
 757         sprintf(ptr, "%9lu %9lu\n", id1, id2);
 758
 759         /*
 760          * And rewrite the data.  Since we write in a single kernel call, this
 761          * update should appear atomic to onlookers.
 762          */
 763         len = strlen(buffer);
 764         errno = 0;
 765         if (lseek(fd, (off_t) 0, SEEK_SET) != 0 ||
 766                 (int) write(fd, buffer, len) != len)
 767         {
 768                 /* if write didn't set errno, assume problem is no disk space */
 769                 if (errno == 0)
 770                         errno = ENOSPC;
 771                 ereport(LOG,
 772                                 (errcode_for_file_access(),
 773                                  errmsg("could not write to file \"%s\": %m",
 774                                                 directoryLockFile)));
 775                 close(fd);
 776                 return;
 777         }
 778         if (close(fd))
 779         {
 780                 ereport(LOG,
 781                                 (errcode_for_file_access(),
 782                                  errmsg("could not write to file \"%s\": %m",
 783                                                 directoryLockFile)));
 784         }
 785 }
 786
 787
 788 /*-------------------------------------------------------------------------
 789  *                              Version checking support
 790  *-------------------------------------------------------------------------
 791  */
 792
 793 /*
 794  * Determine whether the PG_VERSION file in directory `path' indicates
 795  * a data version compatible with the version of this program.
 796  *
 797  * If compatible, return. Otherwise, ereport(FATAL).
 798  */
 799 void
 800 ValidatePgVersion(const char *path)
 801 {
 802         char            full_path[MAXPGPATH];
 803         FILE       *file;
 804         int                     ret;
 805         long            file_major,
 806                                 file_minor;
 807         long            my_major = 0,
 808                                 my_minor = 0;
 809         char       *endptr;
 810         const char *version_string = PG_VERSION;
 811
 812         my_major = strtol(version_string, &endptr, 10);
 813         if (*endptr == '.')
 814                 my_minor = strtol(endptr + 1, NULL, 10);
 815
 816         snprintf(full_path, sizeof(full_path), "%s/PG_VERSION", path);
 817
 818         file = AllocateFile(full_path, "r");
 819         if (!file)
 820         {
 821                 if (errno == ENOENT)
 822                         ereport(FATAL,
 823                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 824                                          errmsg("\"%s\" is not a valid data directory",
 825                                                         path),
 826                                          errdetail("File \"%s\" is missing.", full_path)));
 827                 else
 828                         ereport(FATAL,
 829                                         (errcode_for_file_access(),
 830                                          errmsg("could not open file \"%s\": %m", full_path)));
 831         }
 832
 833         ret = fscanf(file, "%ld.%ld", &file_major, &file_minor);
 834         if (ret != 2)
 835                 ereport(FATAL,
 836                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 837                                  errmsg("\"%s\" is not a valid data directory",
 838                                                 path),
 839                                  errdetail("File \"%s\" does not contain valid data.",
 840                                                    full_path),
 841                                  errhint("You may need to initdb.")));
 842
 843         FreeFile(file);
 844
 845         if (my_major != file_major || my_minor != file_minor)
 846                 ereport(FATAL,
 847                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 848                                  errmsg("database files are incompatible with server"),
 849                                  errdetail("The data directory was initialized by PostgreSQL version %ld.%ld, "
 850                                                  "which is not compatible with this version %s.",
 851                                                    file_major, file_minor, version_string)));
 852 }
 853
 854 /*-------------------------------------------------------------------------
 855  *                              Library preload support
 856  *-------------------------------------------------------------------------
 857  */
 858
 859 #if defined(__mc68000__) && defined(__ELF__)
 860 typedef int32 ((*func_ptr) ());
 861
 862 #else
 863 typedef char *((*func_ptr) ());
 864 #endif
 865
 866 /*
 867  * process any libraries that should be preloaded and
 868  * optionally pre-initialized
 869  */
 870 void
 871 process_preload_libraries(char *preload_libraries_string)
 872 {
 873         char       *rawstring;
 874         List       *elemlist;
 875         ListCell   *l;
 876
 877         if (preload_libraries_string == NULL)
 878                 return;
 879
 880         /* Need a modifiable copy of string */
 881         rawstring = pstrdup(preload_libraries_string);
 882
 883         /* Parse string into list of identifiers */
 884         if (!SplitIdentifierString(rawstring, ',', &elemlist))
 885         {
 886                 /* syntax error in list */
 887                 pfree(rawstring);
 888                 list_free(elemlist);
 889                 ereport(LOG,
 890                                 (errcode(ERRCODE_SYNTAX_ERROR),
 891                                  errmsg("invalid list syntax for parameter \"preload_libraries\"")));
 892                 return;
 893         }
 894
 895         foreach(l, elemlist)
 896         {
 897                 char       *tok = (char *) lfirst(l);
 898                 char       *sep = strstr(tok, ":");
 899                 char       *filename = NULL;
 900                 char       *funcname = NULL;
 901                 func_ptr        initfunc;
 902
 903                 if (sep)
 904                 {
 905                         /*
 906                          * a colon separator implies there is an initialization
 907                          * function that we need to run in addition to loading the
 908                          * library
 909                          */
 910                         size_t          filename_len = sep - tok;
 911                         size_t          funcname_len = strlen(tok) - filename_len - 1;
 912
 913                         filename = (char *) palloc(filename_len + 1);
 914                         memcpy(filename, tok, filename_len);
 915                         filename[filename_len] = '\0';
 916
 917                         funcname = (char *) palloc(funcname_len + 1);
 918                         strcpy(funcname, sep + 1);
 919                 }
 920                 else
 921                 {
 922                         /*
 923                          * no separator -- just load the library
 924                          */
 925                         filename = pstrdup(tok);
 926                         funcname = NULL;
 927                 }
 928
 929                 canonicalize_path(filename);
 930                 initfunc = (func_ptr) load_external_function(filename, funcname,
 931                                                                                                          true, NULL);
 932                 if (initfunc)
 933                         (*initfunc) ();
 934
 935                 if (funcname)
 936                         ereport(LOG,
 937                                         (errmsg("preloaded library \"%s\" with initialization function \"%s\"",
 938                                                         filename, funcname)));
 939                 else
 940                         ereport(LOG,
 941                                         (errmsg("preloaded library \"%s\"",
 942                                                         filename)));
 943
 944                 pfree(filename);
 945                 if (funcname)
 946                         pfree(funcname);
 947         }
 948
 949         pfree(rawstring);
 950         list_free(elemlist);
 951 }