/*------------------------------------------------------------------------- * * miscinit.c * miscellaneous initialization support stuff * * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/backend/utils/init/miscinit.c * *------------------------------------------------------------------------- */ #include "postgres.h" #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_UTIME_H #include #endif #include "access/htup_details.h" #include "catalog/pg_authid.h" #include "mb/pg_wchar.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" #include "postmaster/postmaster.h" #include "storage/fd.h" #include "storage/ipc.h" #include "storage/pg_shmem.h" #include "storage/proc.h" #include "storage/procarray.h" #include "utils/builtins.h" #include "utils/guc.h" #include "utils/memutils.h" #include "utils/syscache.h" #define DIRECTORY_LOCK_FILE "postmaster.pid" ProcessingMode Mode = InitProcessing; /* List of lock files to be removed at proc exit */ static List *lock_files = NIL; /* ---------------------------------------------------------------- * ignoring system indexes support stuff * * NOTE: "ignoring system indexes" means we do not use the system indexes * for lookups (either in hardwired catalog accesses or in planner-generated * plans). We do, however, still update the indexes when a catalog * modification is made. * ---------------------------------------------------------------- */ bool IgnoreSystemIndexes = false; /* ---------------------------------------------------------------- * database path / name support stuff * ---------------------------------------------------------------- */ void SetDatabasePath(const char *path) { /* This should happen only once per process */ Assert(!DatabasePath); DatabasePath = MemoryContextStrdup(TopMemoryContext, path); } /* * Set data directory, but make sure it's an absolute path. Use this, * never set DataDir directly. */ void SetDataDir(const char *dir) { char *new; AssertArg(dir); /* If presented path is relative, convert to absolute */ new = make_absolute_path(dir); if (DataDir) free(DataDir); DataDir = new; } /* * Change working directory to DataDir. Most of the postmaster and backend * code assumes that we are in DataDir so it can use relative paths to access * stuff in and under the data directory. For convenience during path * setup, however, we don't force the chdir to occur during SetDataDir. */ void ChangeToDataDir(void) { AssertState(DataDir); if (chdir(DataDir) < 0) ereport(FATAL, (errcode_for_file_access(), errmsg("could not change directory to \"%s\": %m", DataDir))); } /* ---------------------------------------------------------------- * User ID state * * We have to track several different values associated with the concept * of "user ID". * * AuthenticatedUserId is determined at connection start and never changes. * * SessionUserId is initially the same as AuthenticatedUserId, but can be * changed by SET SESSION AUTHORIZATION (if AuthenticatedUserIsSuperuser). * This is the ID reported by the SESSION_USER SQL function. * * OuterUserId is the current user ID in effect at the "outer level" (outside * any transaction or function). This is initially the same as SessionUserId, * but can be changed by SET ROLE to any role that SessionUserId is a * member of. (XXX rename to something like CurrentRoleId?) * * CurrentUserId is the current effective user ID; this is the one to use * for all normal permissions-checking purposes. At outer level this will * be the same as OuterUserId, but it changes during calls to SECURITY * DEFINER functions, as well as locally in some specialized commands. * * SecurityRestrictionContext holds flags indicating reason(s) for changing * CurrentUserId. In some cases we need to lock down operations that are * not directly controlled by privilege settings, and this provides a * convenient way to do it. * ---------------------------------------------------------------- */ static Oid AuthenticatedUserId = InvalidOid; static Oid SessionUserId = InvalidOid; static Oid OuterUserId = InvalidOid; static Oid CurrentUserId = InvalidOid; /* We also have to remember the superuser state of some of these levels */ static bool AuthenticatedUserIsSuperuser = false; static bool SessionUserIsSuperuser = false; static int SecurityRestrictionContext = 0; /* We also remember if a SET ROLE is currently active */ static bool SetRoleIsActive = false; /* * GetUserId - get the current effective user ID. * * Note: there's no SetUserId() anymore; use SetUserIdAndSecContext(). */ Oid GetUserId(void) { AssertState(OidIsValid(CurrentUserId)); return CurrentUserId; } /* * GetOuterUserId/SetOuterUserId - get/set the outer-level user ID. */ Oid GetOuterUserId(void) { AssertState(OidIsValid(OuterUserId)); return OuterUserId; } static void SetOuterUserId(Oid userid) { AssertState(SecurityRestrictionContext == 0); AssertArg(OidIsValid(userid)); OuterUserId = userid; /* We force the effective user ID to match, too */ CurrentUserId = userid; } /* * GetSessionUserId/SetSessionUserId - get/set the session user ID. */ Oid GetSessionUserId(void) { AssertState(OidIsValid(SessionUserId)); return SessionUserId; } static void SetSessionUserId(Oid userid, bool is_superuser) { AssertState(SecurityRestrictionContext == 0); AssertArg(OidIsValid(userid)); SessionUserId = userid; SessionUserIsSuperuser = is_superuser; SetRoleIsActive = false; /* We force the effective user IDs to match, too */ OuterUserId = userid; CurrentUserId = userid; } /* * GetAuthenticatedUserId - get the authenticated user ID */ Oid GetAuthenticatedUserId(void) { AssertState(OidIsValid(AuthenticatedUserId)); return AuthenticatedUserId; } /* * GetUserIdAndSecContext/SetUserIdAndSecContext - get/set the current user ID * and the SecurityRestrictionContext flags. * * Currently there are two valid bits in SecurityRestrictionContext: * * SECURITY_LOCAL_USERID_CHANGE indicates that we are inside an operation * that is temporarily changing CurrentUserId via these functions. This is * needed to indicate that the actual value of CurrentUserId is not in sync * with guc.c's internal state, so SET ROLE has to be disallowed. * * SECURITY_RESTRICTED_OPERATION indicates that we are inside an operation * that does not wish to trust called user-defined functions at all. This * bit prevents not only SET ROLE, but various other changes of session state * that normally is unprotected but might possibly be used to subvert the * calling session later. An example is replacing an existing prepared * statement with new code, which will then be executed with the outer * session's permissions when the prepared statement is next used. Since * these restrictions are fairly draconian, we apply them only in contexts * where the called functions are really supposed to be side-effect-free * anyway, such as VACUUM/ANALYZE/REINDEX. * * Unlike GetUserId, GetUserIdAndSecContext does *not* Assert that the current * value of CurrentUserId is valid; nor does SetUserIdAndSecContext require * the new value to be valid. In fact, these routines had better not * ever throw any kind of error. This is because they are used by * StartTransaction and AbortTransaction to save/restore the settings, * and during the first transaction within a backend, the value to be saved * and perhaps restored is indeed invalid. We have to be able to get * through AbortTransaction without asserting in case InitPostgres fails. */ void GetUserIdAndSecContext(Oid *userid, int *sec_context) { *userid = CurrentUserId; *sec_context = SecurityRestrictionContext; } void SetUserIdAndSecContext(Oid userid, int sec_context) { CurrentUserId = userid; SecurityRestrictionContext = sec_context; } /* * InLocalUserIdChange - are we inside a local change of CurrentUserId? */ bool InLocalUserIdChange(void) { return (SecurityRestrictionContext & SECURITY_LOCAL_USERID_CHANGE) != 0; } /* * InSecurityRestrictedOperation - are we inside a security-restricted command? */ bool InSecurityRestrictedOperation(void) { return (SecurityRestrictionContext & SECURITY_RESTRICTED_OPERATION) != 0; } /* * These are obsolete versions of Get/SetUserIdAndSecContext that are * only provided for bug-compatibility with some rather dubious code in * pljava. We allow the userid to be set, but only when not inside a * security restriction context. */ void GetUserIdAndContext(Oid *userid, bool *sec_def_context) { *userid = CurrentUserId; *sec_def_context = InLocalUserIdChange(); } void SetUserIdAndContext(Oid userid, bool sec_def_context) { /* We throw the same error SET ROLE would. */ if (InSecurityRestrictedOperation()) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("cannot set parameter \"%s\" within security-restricted operation", "role"))); CurrentUserId = userid; if (sec_def_context) SecurityRestrictionContext |= SECURITY_LOCAL_USERID_CHANGE; else SecurityRestrictionContext &= ~SECURITY_LOCAL_USERID_CHANGE; } /* * Check whether specified role has explicit REPLICATION privilege */ bool has_rolreplication(Oid roleid) { bool result = false; HeapTuple utup; utup = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid)); if (HeapTupleIsValid(utup)) { result = ((Form_pg_authid) GETSTRUCT(utup))->rolreplication; ReleaseSysCache(utup); } return result; } /* * Initialize user identity during normal backend startup */ void InitializeSessionUserId(const char *rolename) { HeapTuple roleTup; Form_pg_authid rform; Oid roleid; /* * Don't do scans if we're bootstrapping, none of the system catalogs * exist yet, and they should be owned by postgres anyway. */ AssertState(!IsBootstrapProcessingMode()); /* call only once */ AssertState(!OidIsValid(AuthenticatedUserId)); roleTup = SearchSysCache1(AUTHNAME, PointerGetDatum(rolename)); if (!HeapTupleIsValid(roleTup)) ereport(FATAL, (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION), errmsg("role \"%s\" does not exist", rolename))); rform = (Form_pg_authid) GETSTRUCT(roleTup); roleid = HeapTupleGetOid(roleTup); AuthenticatedUserId = roleid; AuthenticatedUserIsSuperuser = rform->rolsuper; /* This sets OuterUserId/CurrentUserId too */ SetSessionUserId(roleid, AuthenticatedUserIsSuperuser); /* Also mark our PGPROC entry with the authenticated user id */ /* (We assume this is an atomic store so no lock is needed) */ MyProc->roleId = roleid; /* * These next checks are not enforced when in standalone mode, so that * there is a way to recover from sillinesses like "UPDATE pg_authid SET * rolcanlogin = false;". */ if (IsUnderPostmaster) { /* * Is role allowed to login at all? */ if (!rform->rolcanlogin) ereport(FATAL, (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION), errmsg("role \"%s\" is not permitted to log in", rolename))); /* * Check connection limit for this role. * * There is a race condition here --- we create our PGPROC before * checking for other PGPROCs. If two backends did this at about the * same time, they might both think they were over the limit, while * ideally one should succeed and one fail. Getting that to work * exactly seems more trouble than it is worth, however; instead we * just document that the connection limit is approximate. */ if (rform->rolconnlimit >= 0 && !AuthenticatedUserIsSuperuser && CountUserBackends(roleid) > rform->rolconnlimit) ereport(FATAL, (errcode(ERRCODE_TOO_MANY_CONNECTIONS), errmsg("too many connections for role \"%s\"", rolename))); } /* Record username and superuser status as GUC settings too */ SetConfigOption("session_authorization", rolename, PGC_BACKEND, PGC_S_OVERRIDE); SetConfigOption("is_superuser", AuthenticatedUserIsSuperuser ? "on" : "off", PGC_INTERNAL, PGC_S_OVERRIDE); ReleaseSysCache(roleTup); } /* * Initialize user identity during special backend startup */ void InitializeSessionUserIdStandalone(void) { /* * This function should only be called in single-user mode, in autovacuum * workers, and in background workers. */ AssertState(!IsUnderPostmaster || IsAutoVacuumWorkerProcess() || IsBackgroundWorker); /* call only once */ AssertState(!OidIsValid(AuthenticatedUserId)); AuthenticatedUserId = BOOTSTRAP_SUPERUSERID; AuthenticatedUserIsSuperuser = true; SetSessionUserId(BOOTSTRAP_SUPERUSERID, true); } /* * Change session auth ID while running * * Only a superuser may set auth ID to something other than himself. Note * that in case of multiple SETs in a single session, the original userid's * superuserness is what matters. But we set the GUC variable is_superuser * to indicate whether the *current* session userid is a superuser. * * Note: this is not an especially clean place to do the permission check. * It's OK because the check does not require catalog access and can't * fail during an end-of-transaction GUC reversion, but we may someday * have to push it up into assign_session_authorization. */ void SetSessionAuthorization(Oid userid, bool is_superuser) { /* Must have authenticated already, else can't make permission check */ AssertState(OidIsValid(AuthenticatedUserId)); if (userid != AuthenticatedUserId && !AuthenticatedUserIsSuperuser) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied to set session authorization"))); SetSessionUserId(userid, is_superuser); SetConfigOption("is_superuser", is_superuser ? "on" : "off", PGC_INTERNAL, PGC_S_OVERRIDE); } /* * Report current role id * This follows the semantics of SET ROLE, ie return the outer-level ID * not the current effective ID, and return InvalidOid when the setting * is logically SET ROLE NONE. */ Oid GetCurrentRoleId(void) { if (SetRoleIsActive) return OuterUserId; else return InvalidOid; } /* * Change Role ID while running (SET ROLE) * * If roleid is InvalidOid, we are doing SET ROLE NONE: revert to the * session user authorization. In this case the is_superuser argument * is ignored. * * When roleid is not InvalidOid, the caller must have checked whether * the session user has permission to become that role. (We cannot check * here because this routine must be able to execute in a failed transaction * to restore a prior value of the ROLE GUC variable.) */ void SetCurrentRoleId(Oid roleid, bool is_superuser) { /* * Get correct info if it's SET ROLE NONE * * If SessionUserId hasn't been set yet, just do nothing --- the eventual * SetSessionUserId call will fix everything. This is needed since we * will get called during GUC initialization. */ if (!OidIsValid(roleid)) { if (!OidIsValid(SessionUserId)) return; roleid = SessionUserId; is_superuser = SessionUserIsSuperuser; SetRoleIsActive = false; } else SetRoleIsActive = true; SetOuterUserId(roleid); SetConfigOption("is_superuser", is_superuser ? "on" : "off", PGC_INTERNAL, PGC_S_OVERRIDE); } /* * Get user name from user oid */ char * GetUserNameFromId(Oid roleid) { HeapTuple tuple; char *result; tuple = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid)); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("invalid role OID: %u", roleid))); result = pstrdup(NameStr(((Form_pg_authid) GETSTRUCT(tuple))->rolname)); ReleaseSysCache(tuple); return result; } /*------------------------------------------------------------------------- * Interlock-file support * * These routines are used to create both a data-directory lockfile * ($DATADIR/postmaster.pid) and Unix-socket-file lockfiles ($SOCKFILE.lock). * Both kinds of files contain the same info initially, although we can add * more information to a data-directory lockfile after it's created, using * AddToDataDirLockFile(). See miscadmin.h for documentation of the contents * of these lockfiles. * * On successful lockfile creation, a proc_exit callback to remove the * lockfile is automatically created. *------------------------------------------------------------------------- */ /* * proc_exit callback to remove lockfiles. */ static void UnlinkLockFiles(int status, Datum arg) { ListCell *l; foreach(l, lock_files) { char *curfile = (char *) lfirst(l); unlink(curfile); /* Should we complain if the unlink fails? */ } /* Since we're about to exit, no need to reclaim storage */ lock_files = NIL; } /* * Create a lockfile. * * filename is the path name of the lockfile to create. * amPostmaster is used to determine how to encode the output PID. * socketDir is the Unix socket directory path to include (possibly empty). * isDDLock and refName are used to determine what error message to produce. */ static void CreateLockFile(const char *filename, bool amPostmaster, const char *socketDir, bool isDDLock, const char *refName) { int fd; char buffer[MAXPGPATH * 2 + 256]; int ntries; int len; int encoded_pid; pid_t other_pid; pid_t my_pid, my_p_pid, my_gp_pid; const char *envvar; /* * If the PID in the lockfile is our own PID or our parent's or * grandparent's PID, then the file must be stale (probably left over from * a previous system boot cycle). We need to check this because of the * likelihood that a reboot will assign exactly the same PID as we had in * the previous reboot, or one that's only one or two counts larger and * hence the lockfile's PID now refers to an ancestor shell process. We * allow pg_ctl to pass down its parent shell PID (our grandparent PID) * via the environment variable PG_GRANDPARENT_PID; this is so that * launching the postmaster via pg_ctl can be just as reliable as * launching it directly. There is no provision for detecting * further-removed ancestor processes, but if the init script is written * carefully then all but the immediate parent shell will be root-owned * processes and so the kill test will fail with EPERM. Note that we * cannot get a false negative this way, because an existing postmaster * would surely never launch a competing postmaster or pg_ctl process * directly. */ my_pid = getpid(); #ifndef WIN32 my_p_pid = getppid(); #else /* * Windows hasn't got getppid(), but doesn't need it since it's not using * real kill() either... */ my_p_pid = 0; #endif envvar = getenv("PG_GRANDPARENT_PID"); if (envvar) my_gp_pid = atoi(envvar); else my_gp_pid = 0; /* * We need a loop here because of race conditions. But don't loop forever * (for example, a non-writable $PGDATA directory might cause a failure * that won't go away). 100 tries seems like plenty. */ for (ntries = 0;; ntries++) { /* * Try to create the lock file --- O_EXCL makes this atomic. * * Think not to make the file protection weaker than 0600. See * comments below. */ fd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600); if (fd >= 0) break; /* Success; exit the retry loop */ /* * Couldn't create the pid file. Probably it already exists. */ if ((errno != EEXIST && errno != EACCES) || ntries > 100) ereport(FATAL, (errcode_for_file_access(), errmsg("could not create lock file \"%s\": %m", filename))); /* * Read the file to get the old owner's PID. Note race condition * here: file might have been deleted since we tried to create it. */ fd = open(filename, O_RDONLY, 0600); if (fd < 0) { if (errno == ENOENT) continue; /* race condition; try again */ ereport(FATAL, (errcode_for_file_access(), errmsg("could not open lock file \"%s\": %m", filename))); } if ((len = read(fd, buffer, sizeof(buffer) - 1)) < 0) ereport(FATAL, (errcode_for_file_access(), errmsg("could not read lock file \"%s\": %m", filename))); close(fd); if (len == 0) { ereport(FATAL, (errcode(ERRCODE_LOCK_FILE_EXISTS), errmsg("lock file \"%s\" is empty", filename), errhint("Either another server is starting, or the lock file is the remnant of a previous server startup crash."))); } buffer[len] = '\0'; encoded_pid = atoi(buffer); /* if pid < 0, the pid is for postgres, not postmaster */ other_pid = (pid_t) (encoded_pid < 0 ? -encoded_pid : encoded_pid); if (other_pid <= 0) elog(FATAL, "bogus data in lock file \"%s\": \"%s\"", filename, buffer); /* * Check to see if the other process still exists * * Per discussion above, my_pid, my_p_pid, and my_gp_pid can be * ignored as false matches. * * Normally kill() will fail with ESRCH if the given PID doesn't * exist. * * We can treat the EPERM-error case as okay because that error * implies that the existing process has a different userid than we * do, which means it cannot be a competing postmaster. A postmaster * cannot successfully attach to a data directory owned by a userid * other than its own. (This is now checked directly in * checkDataDir(), but has been true for a long time because of the * restriction that the data directory isn't group- or * world-accessible.) Also, since we create the lockfiles mode 600, * we'd have failed above if the lockfile belonged to another userid * --- which means that whatever process kill() is reporting about * isn't the one that made the lockfile. (NOTE: this last * consideration is the only one that keeps us from blowing away a * Unix socket file belonging to an instance of Postgres being run by * someone else, at least on machines where /tmp hasn't got a * stickybit.) */ if (other_pid != my_pid && other_pid != my_p_pid && other_pid != my_gp_pid) { if (kill(other_pid, 0) == 0 || (errno != ESRCH && errno != EPERM)) { /* lockfile belongs to a live process */ ereport(FATAL, (errcode(ERRCODE_LOCK_FILE_EXISTS), errmsg("lock file \"%s\" already exists", filename), isDDLock ? (encoded_pid < 0 ? errhint("Is another postgres (PID %d) running in data directory \"%s\"?", (int) other_pid, refName) : errhint("Is another postmaster (PID %d) running in data directory \"%s\"?", (int) other_pid, refName)) : (encoded_pid < 0 ? errhint("Is another postgres (PID %d) using socket file \"%s\"?", (int) other_pid, refName) : errhint("Is another postmaster (PID %d) using socket file \"%s\"?", (int) other_pid, refName)))); } } /* * No, the creating process did not exist. However, it could be that * the postmaster crashed (or more likely was kill -9'd by a clueless * admin) but has left orphan backends behind. Check for this by * looking to see if there is an associated shmem segment that is * still in use. * * Note: because postmaster.pid is written in multiple steps, we might * not find the shmem ID values in it; we can't treat that as an * error. */ if (isDDLock) { char *ptr = buffer; unsigned long id1, id2; int lineno; for (lineno = 1; lineno < LOCK_FILE_LINE_SHMEM_KEY; lineno++) { if ((ptr = strchr(ptr, '\n')) == NULL) break; ptr++; } if (ptr != NULL && sscanf(ptr, "%lu %lu", &id1, &id2) == 2) { if (PGSharedMemoryIsInUse(id1, id2)) ereport(FATAL, (errcode(ERRCODE_LOCK_FILE_EXISTS), errmsg("pre-existing shared memory block " "(key %lu, ID %lu) is still in use", id1, id2), errhint("If you're sure there are no old " "server processes still running, remove " "the shared memory block " "or just delete the file \"%s\".", filename))); } } /* * Looks like nobody's home. Unlink the file and try again to create * it. Need a loop because of possible race condition against other * would-be creators. */ if (unlink(filename) < 0) ereport(FATAL, (errcode_for_file_access(), errmsg("could not remove old lock file \"%s\": %m", filename), errhint("The file seems accidentally left over, but " "it could not be removed. Please remove the file " "by hand and try again."))); } /* * Successfully created the file, now fill it. See comment in miscadmin.h * about the contents. Note that we write the same first five lines into * both datadir and socket lockfiles; although more stuff may get added to * the datadir lockfile later. */ snprintf(buffer, sizeof(buffer), "%d\n%s\n%ld\n%d\n%s\n", amPostmaster ? (int) my_pid : -((int) my_pid), DataDir, (long) MyStartTime, PostPortNumber, socketDir); /* * In a standalone backend, the next line (LOCK_FILE_LINE_LISTEN_ADDR) * will never receive data, so fill it in as empty now. */ if (isDDLock && !amPostmaster) strlcat(buffer, "\n", sizeof(buffer)); errno = 0; if (write(fd, buffer, strlen(buffer)) != strlen(buffer)) { int save_errno = errno; close(fd); unlink(filename); /* if write didn't set errno, assume problem is no disk space */ errno = save_errno ? save_errno : ENOSPC; ereport(FATAL, (errcode_for_file_access(), errmsg("could not write lock file \"%s\": %m", filename))); } if (pg_fsync(fd) != 0) { int save_errno = errno; close(fd); unlink(filename); errno = save_errno; ereport(FATAL, (errcode_for_file_access(), errmsg("could not write lock file \"%s\": %m", filename))); } if (close(fd) != 0) { int save_errno = errno; unlink(filename); errno = save_errno; ereport(FATAL, (errcode_for_file_access(), errmsg("could not write lock file \"%s\": %m", filename))); } /* * Arrange to unlink the lock file(s) at proc_exit. If this is the first * one, set up the on_proc_exit function to do it; then add this lock file * to the list of files to unlink. */ if (lock_files == NIL) on_proc_exit(UnlinkLockFiles, 0); lock_files = lappend(lock_files, pstrdup(filename)); } /* * Create the data directory lockfile. * * When this is called, we must have already switched the working * directory to DataDir, so we can just use a relative path. This * helps ensure that we are locking the directory we should be. * * Note that the socket directory path line is initially written as empty. * postmaster.c will rewrite it upon creating the first Unix socket. */ void CreateDataDirLockFile(bool amPostmaster) { CreateLockFile(DIRECTORY_LOCK_FILE, amPostmaster, "", true, DataDir); } /* * Create a lockfile for the specified Unix socket file. */ void CreateSocketLockFile(const char *socketfile, bool amPostmaster, const char *socketDir) { char lockfile[MAXPGPATH]; snprintf(lockfile, sizeof(lockfile), "%s.lock", socketfile); CreateLockFile(lockfile, amPostmaster, socketDir, false, socketfile); } /* * TouchSocketLockFiles -- mark socket lock files as recently accessed * * This routine should be called every so often to ensure that the socket * lock files have a recent mod or access date. That saves them * from being removed by overenthusiastic /tmp-directory-cleaner daemons. * (Another reason we should never have put the socket file in /tmp...) */ void TouchSocketLockFiles(void) { ListCell *l; foreach(l, lock_files) { char *socketLockFile = (char *) lfirst(l); /* No need to touch the data directory lock file, we trust */ if (strcmp(socketLockFile, DIRECTORY_LOCK_FILE) == 0) continue; /* * utime() is POSIX standard, utimes() is a common alternative; if we * have neither, fall back to actually reading the file (which only * sets the access time not mod time, but that should be enough in * most cases). In all paths, we ignore errors. */ #ifdef HAVE_UTIME utime(socketLockFile, NULL); #else /* !HAVE_UTIME */ #ifdef HAVE_UTIMES utimes(socketLockFile, NULL); #else /* !HAVE_UTIMES */ int fd; char buffer[1]; fd = open(socketLockFile, O_RDONLY | PG_BINARY, 0); if (fd >= 0) { read(fd, buffer, sizeof(buffer)); close(fd); } #endif /* HAVE_UTIMES */ #endif /* HAVE_UTIME */ } } /* * Add (or replace) a line in the data directory lock file. * The given string should not include a trailing newline. * * Note: because we don't truncate the file, if we were to rewrite a line * with less data than it had before, there would be garbage after the last * line. We don't ever actually do that, so not worth adding another kernel * call to cover the possibility. */ void AddToDataDirLockFile(int target_line, const char *str) { int fd; int len; int lineno; char *srcptr; char *destptr; char srcbuffer[BLCKSZ]; char destbuffer[BLCKSZ]; fd = open(DIRECTORY_LOCK_FILE, O_RDWR | PG_BINARY, 0); if (fd < 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not open file \"%s\": %m", DIRECTORY_LOCK_FILE))); return; } len = read(fd, srcbuffer, sizeof(srcbuffer) - 1); if (len < 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not read from file \"%s\": %m", DIRECTORY_LOCK_FILE))); close(fd); return; } srcbuffer[len] = '\0'; /* * Advance over lines we are not supposed to rewrite, then copy them to * destbuffer. */ srcptr = srcbuffer; for (lineno = 1; lineno < target_line; lineno++) { if ((srcptr = strchr(srcptr, '\n')) == NULL) { elog(LOG, "incomplete data in \"%s\": found only %d newlines while trying to add line %d", DIRECTORY_LOCK_FILE, lineno - 1, target_line); close(fd); return; } srcptr++; } memcpy(destbuffer, srcbuffer, srcptr - srcbuffer); destptr = destbuffer + (srcptr - srcbuffer); /* * Write or rewrite the target line. */ snprintf(destptr, destbuffer + sizeof(destbuffer) - destptr, "%s\n", str); destptr += strlen(destptr); /* * If there are more lines in the old file, append them to destbuffer. */ if ((srcptr = strchr(srcptr, '\n')) != NULL) { srcptr++; snprintf(destptr, destbuffer + sizeof(destbuffer) - destptr, "%s", srcptr); } /* * And rewrite the data. Since we write in a single kernel call, this * update should appear atomic to onlookers. */ len = strlen(destbuffer); errno = 0; if (lseek(fd, (off_t) 0, SEEK_SET) != 0 || (int) write(fd, destbuffer, len) != len) { /* if write didn't set errno, assume problem is no disk space */ if (errno == 0) errno = ENOSPC; ereport(LOG, (errcode_for_file_access(), errmsg("could not write to file \"%s\": %m", DIRECTORY_LOCK_FILE))); close(fd); return; } if (pg_fsync(fd) != 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not write to file \"%s\": %m", DIRECTORY_LOCK_FILE))); } if (close(fd) != 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not write to file \"%s\": %m", DIRECTORY_LOCK_FILE))); } } /*------------------------------------------------------------------------- * Version checking support *------------------------------------------------------------------------- */ /* * Determine whether the PG_VERSION file in directory `path' indicates * a data version compatible with the version of this program. * * If compatible, return. Otherwise, ereport(FATAL). */ void ValidatePgVersion(const char *path) { char full_path[MAXPGPATH]; FILE *file; int ret; long file_major, file_minor; long my_major = 0, my_minor = 0; char *endptr; const char *version_string = PG_VERSION; my_major = strtol(version_string, &endptr, 10); if (*endptr == '.') my_minor = strtol(endptr + 1, NULL, 10); snprintf(full_path, sizeof(full_path), "%s/PG_VERSION", path); file = AllocateFile(full_path, "r"); if (!file) { if (errno == ENOENT) ereport(FATAL, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("\"%s\" is not a valid data directory", path), errdetail("File \"%s\" is missing.", full_path))); else ereport(FATAL, (errcode_for_file_access(), errmsg("could not open file \"%s\": %m", full_path))); } ret = fscanf(file, "%ld.%ld", &file_major, &file_minor); if (ret != 2) ereport(FATAL, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("\"%s\" is not a valid data directory", path), errdetail("File \"%s\" does not contain valid data.", full_path), errhint("You might need to initdb."))); FreeFile(file); if (my_major != file_major || my_minor != file_minor) ereport(FATAL, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("database files are incompatible with server"), errdetail("The data directory was initialized by PostgreSQL version %ld.%ld, " "which is not compatible with this version %s.", file_major, file_minor, version_string))); } /*------------------------------------------------------------------------- * Library preload support *------------------------------------------------------------------------- */ /* * GUC variables: lists of library names to be preloaded at postmaster * start and at backend start */ char *session_preload_libraries_string = NULL; char *shared_preload_libraries_string = NULL; char *local_preload_libraries_string = NULL; /* Flag telling that we are loading shared_preload_libraries */ bool process_shared_preload_libraries_in_progress = false; /* * load the shared libraries listed in 'libraries' * * 'gucname': name of GUC variable, for error reports * 'restricted': if true, force libraries to be in $libdir/plugins/ */ static void load_libraries(const char *libraries, const char *gucname, bool restricted) { char *rawstring; List *elemlist; ListCell *l; if (libraries == NULL || libraries[0] == '\0') return; /* nothing to do */ /* Need a modifiable copy of string */ rawstring = pstrdup(libraries); /* Parse string into list of identifiers */ if (!SplitIdentifierString(rawstring, ',', &elemlist)) { /* syntax error in list */ pfree(rawstring); list_free(elemlist); ereport(LOG, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("invalid list syntax in parameter \"%s\"", gucname))); return; } foreach(l, elemlist) { char *tok = (char *) lfirst(l); char *filename; filename = pstrdup(tok); canonicalize_path(filename); /* If restricting, insert $libdir/plugins if not mentioned already */ if (restricted && first_dir_separator(filename) == NULL) { char *expanded; expanded = psprintf("$libdir/plugins/%s", filename); pfree(filename); filename = expanded; } load_file(filename, restricted); ereport(DEBUG1, (errmsg("loaded library \"%s\"", filename))); pfree(filename); } pfree(rawstring); list_free(elemlist); } /* * process any libraries that should be preloaded at postmaster start */ void process_shared_preload_libraries(void) { process_shared_preload_libraries_in_progress = true; load_libraries(shared_preload_libraries_string, "shared_preload_libraries", false); process_shared_preload_libraries_in_progress = false; } /* * process any libraries that should be preloaded at backend start */ void process_session_preload_libraries(void) { load_libraries(session_preload_libraries_string, "session_preload_libraries", false); load_libraries(local_preload_libraries_string, "local_preload_libraries", true); } void pg_bindtextdomain(const char *domain) { #ifdef ENABLE_NLS if (my_exec_path[0] != '\0') { char locale_path[MAXPGPATH]; get_locale_path(my_exec_path, locale_path); bindtextdomain(domain, locale_path); pg_bind_textdomain_codeset(domain); } #endif }