LCOV - code coverage report
Current view: top level - src/backend/utils/init - miscinit.c (source / functions) Hit Total Coverage
Test: PostgreSQL 13beta1 Lines: 339 445 76.2 %
Date: 2020-06-01 09:07:10 Functions: 38 41 92.7 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * miscinit.c
       4             :  *    miscellaneous initialization support stuff
       5             :  *
       6             :  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
       7             :  * Portions Copyright (c) 1994, Regents of the University of California
       8             :  *
       9             :  *
      10             :  * IDENTIFICATION
      11             :  *    src/backend/utils/init/miscinit.c
      12             :  *
      13             :  *-------------------------------------------------------------------------
      14             :  */
      15             : #include "postgres.h"
      16             : 
      17             : #include <sys/param.h>
      18             : #include <signal.h>
      19             : #include <time.h>
      20             : #include <sys/file.h>
      21             : #include <sys/stat.h>
      22             : #include <sys/time.h>
      23             : #include <fcntl.h>
      24             : #include <unistd.h>
      25             : #include <grp.h>
      26             : #include <pwd.h>
      27             : #include <netinet/in.h>
      28             : #include <arpa/inet.h>
      29             : #include <utime.h>
      30             : 
      31             : #include "access/htup_details.h"
      32             : #include "catalog/pg_authid.h"
      33             : #include "common/file_perm.h"
      34             : #include "libpq/libpq.h"
      35             : #include "mb/pg_wchar.h"
      36             : #include "miscadmin.h"
      37             : #include "pgstat.h"
      38             : #include "postmaster/autovacuum.h"
      39             : #include "postmaster/postmaster.h"
      40             : #include "storage/fd.h"
      41             : #include "storage/ipc.h"
      42             : #include "storage/latch.h"
      43             : #include "storage/pg_shmem.h"
      44             : #include "storage/pmsignal.h"
      45             : #include "storage/proc.h"
      46             : #include "storage/procarray.h"
      47             : #include "utils/builtins.h"
      48             : #include "utils/guc.h"
      49             : #include "utils/inval.h"
      50             : #include "utils/memutils.h"
      51             : #include "utils/pidfile.h"
      52             : #include "utils/syscache.h"
      53             : #include "utils/varlena.h"
      54             : 
      55             : 
      56             : #define DIRECTORY_LOCK_FILE     "postmaster.pid"
      57             : 
      58             : ProcessingMode Mode = InitProcessing;
      59             : 
      60             : BackendType MyBackendType;
      61             : 
      62             : /* List of lock files to be removed at proc exit */
      63             : static List *lock_files = NIL;
      64             : 
      65             : static Latch LocalLatchData;
      66             : 
      67             : /* ----------------------------------------------------------------
      68             :  *      ignoring system indexes support stuff
      69             :  *
      70             :  * NOTE: "ignoring system indexes" means we do not use the system indexes
      71             :  * for lookups (either in hardwired catalog accesses or in planner-generated
      72             :  * plans).  We do, however, still update the indexes when a catalog
      73             :  * modification is made.
      74             :  * ----------------------------------------------------------------
      75             :  */
      76             : 
      77             : bool        IgnoreSystemIndexes = false;
      78             : 
      79             : 
      80             : /* ----------------------------------------------------------------
      81             :  *  common process startup code
      82             :  * ----------------------------------------------------------------
      83             :  */
      84             : 
      85             : /*
      86             :  * Initialize the basic environment for a postmaster child
      87             :  *
      88             :  * Should be called as early as possible after the child's startup.
      89             :  */
      90             : void
      91       13244 : InitPostmasterChild(void)
      92             : {
      93       13244 :     IsUnderPostmaster = true;   /* we are a postmaster subprocess now */
      94             : 
      95             :     /*
      96             :      * Set reference point for stack-depth checking. We re-do that even in the
      97             :      * !EXEC_BACKEND case, because there are some edge cases where processes
      98             :      * are started with an alternative stack (e.g. starting bgworkers when
      99             :      * running postgres using the rr debugger, as bgworkers are launched from
     100             :      * signal handlers).
     101             :      */
     102       13244 :     set_stack_base();
     103             : 
     104       13244 :     InitProcessGlobals();
     105             : 
     106             :     /*
     107             :      * make sure stderr is in binary mode before anything can possibly be
     108             :      * written to it, in case it's actually the syslogger pipe, so the pipe
     109             :      * chunking protocol isn't disturbed. Non-logpipe data gets translated on
     110             :      * redirection (e.g. via pg_ctl -l) anyway.
     111             :      */
     112             : #ifdef WIN32
     113             :     _setmode(fileno(stderr), _O_BINARY);
     114             : #endif
     115             : 
     116             :     /* We don't want the postmaster's proc_exit() handlers */
     117       13244 :     on_exit_reset();
     118             : 
     119             :     /* Initialize process-local latch support */
     120       13244 :     InitializeLatchSupport();
     121       13244 :     MyLatch = &LocalLatchData;
     122       13244 :     InitLatch(MyLatch);
     123             : 
     124             :     /*
     125             :      * If possible, make this process a group leader, so that the postmaster
     126             :      * can signal any child processes too. Not all processes will have
     127             :      * children, but for consistency we make all postmaster child processes do
     128             :      * this.
     129             :      */
     130             : #ifdef HAVE_SETSID
     131       13244 :     if (setsid() < 0)
     132           0 :         elog(FATAL, "setsid() failed: %m");
     133             : #endif
     134             : 
     135             :     /* Request a signal if the postmaster dies, if possible. */
     136       13244 :     PostmasterDeathSignalInit();
     137       13244 : }
     138             : 
     139             : /*
     140             :  * Initialize the basic environment for a standalone process.
     141             :  *
     142             :  * argv0 has to be suitable to find the program's executable.
     143             :  */
     144             : void
     145        1454 : InitStandaloneProcess(const char *argv0)
     146             : {
     147             :     Assert(!IsPostmasterEnvironment);
     148             : 
     149        1454 :     InitProcessGlobals();
     150             : 
     151             :     /* Initialize process-local latch support */
     152        1454 :     InitializeLatchSupport();
     153        1454 :     MyLatch = &LocalLatchData;
     154        1454 :     InitLatch(MyLatch);
     155             : 
     156             :     /* Compute paths, no postmaster to inherit from */
     157        1454 :     if (my_exec_path[0] == '\0')
     158             :     {
     159        1454 :         if (find_my_exec(argv0, my_exec_path) < 0)
     160           0 :             elog(FATAL, "%s: could not locate my own executable path",
     161             :                  argv0);
     162             :     }
     163             : 
     164        1454 :     if (pkglib_path[0] == '\0')
     165        1454 :         get_pkglib_path(my_exec_path, pkglib_path);
     166        1454 : }
     167             : 
     168             : void
     169       13150 : SwitchToSharedLatch(void)
     170             : {
     171             :     Assert(MyLatch == &LocalLatchData);
     172             :     Assert(MyProc != NULL);
     173             : 
     174       13150 :     MyLatch = &MyProc->procLatch;
     175             : 
     176       13150 :     if (FeBeWaitSet)
     177        7860 :         ModifyWaitEvent(FeBeWaitSet, 1, WL_LATCH_SET, MyLatch);
     178             : 
     179             :     /*
     180             :      * Set the shared latch as the local one might have been set. This
     181             :      * shouldn't normally be necessary as code is supposed to check the
     182             :      * condition before waiting for the latch, but a bit care can't hurt.
     183             :      */
     184       13150 :     SetLatch(MyLatch);
     185       13150 : }
     186             : 
     187             : void
     188       13150 : SwitchBackToLocalLatch(void)
     189             : {
     190             :     Assert(MyLatch != &LocalLatchData);
     191             :     Assert(MyProc != NULL && MyLatch == &MyProc->procLatch);
     192             : 
     193       13150 :     MyLatch = &LocalLatchData;
     194             : 
     195       13150 :     if (FeBeWaitSet)
     196        7860 :         ModifyWaitEvent(FeBeWaitSet, 1, WL_LATCH_SET, MyLatch);
     197             : 
     198       13150 :     SetLatch(MyLatch);
     199       13150 : }
     200             : 
     201             : const char *
     202       38358 : GetBackendTypeDesc(BackendType backendType)
     203             : {
     204       38358 :     const char *backendDesc = "unknown process type";
     205             : 
     206       38358 :     switch (backendType)
     207             :     {
     208           0 :         case B_INVALID:
     209           0 :             backendDesc = "not initialized";
     210           0 :             break;
     211         666 :         case B_AUTOVAC_LAUNCHER:
     212         666 :             backendDesc = "autovacuum launcher";
     213         666 :             break;
     214         350 :         case B_AUTOVAC_WORKER:
     215         350 :             backendDesc = "autovacuum worker";
     216         350 :             break;
     217       31396 :         case B_BACKEND:
     218       31396 :             backendDesc = "client backend";
     219       31396 :             break;
     220           0 :         case B_BG_WORKER:
     221           0 :             backendDesc = "background worker";
     222           0 :             break;
     223         722 :         case B_BG_WRITER:
     224         722 :             backendDesc = "background writer";
     225         722 :             break;
     226        1690 :         case B_CHECKPOINTER:
     227        1690 :             backendDesc = "checkpointer";
     228        1690 :             break;
     229         796 :         case B_STARTUP:
     230         796 :             backendDesc = "startup";
     231         796 :             break;
     232         216 :         case B_WAL_RECEIVER:
     233         216 :             backendDesc = "walreceiver";
     234         216 :             break;
     235        1096 :         case B_WAL_SENDER:
     236        1096 :             backendDesc = "walsender";
     237        1096 :             break;
     238         682 :         case B_WAL_WRITER:
     239         682 :             backendDesc = "walwriter";
     240         682 :             break;
     241          22 :         case B_ARCHIVER:
     242          22 :             backendDesc = "archiver";
     243          22 :             break;
     244         720 :         case B_STATS_COLLECTOR:
     245         720 :             backendDesc = "stats collector";
     246         720 :             break;
     247           2 :         case B_LOGGER:
     248           2 :             backendDesc = "logger";
     249           2 :             break;
     250             :     }
     251             : 
     252       38358 :     return backendDesc;
     253             : }
     254             : 
     255             : /* ----------------------------------------------------------------
     256             :  *              database path / name support stuff
     257             :  * ----------------------------------------------------------------
     258             :  */
     259             : 
     260             : void
     261        9920 : SetDatabasePath(const char *path)
     262             : {
     263             :     /* This should happen only once per process */
     264             :     Assert(!DatabasePath);
     265        9920 :     DatabasePath = MemoryContextStrdup(TopMemoryContext, path);
     266        9920 : }
     267             : 
     268             : /*
     269             :  * Validate the proposed data directory.
     270             :  *
     271             :  * Also initialize file and directory create modes and mode mask.
     272             :  */
     273             : void
     274        2180 : checkDataDir(void)
     275             : {
     276             :     struct stat stat_buf;
     277             : 
     278             :     Assert(DataDir);
     279             : 
     280        2180 :     if (stat(DataDir, &stat_buf) != 0)
     281             :     {
     282           0 :         if (errno == ENOENT)
     283           0 :             ereport(FATAL,
     284             :                     (errcode_for_file_access(),
     285             :                      errmsg("data directory \"%s\" does not exist",
     286             :                             DataDir)));
     287             :         else
     288           0 :             ereport(FATAL,
     289             :                     (errcode_for_file_access(),
     290             :                      errmsg("could not read permissions of directory \"%s\": %m",
     291             :                             DataDir)));
     292             :     }
     293             : 
     294             :     /* eventual chdir would fail anyway, but let's test ... */
     295        2180 :     if (!S_ISDIR(stat_buf.st_mode))
     296           0 :         ereport(FATAL,
     297             :                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
     298             :                  errmsg("specified data directory \"%s\" is not a directory",
     299             :                         DataDir)));
     300             : 
     301             :     /*
     302             :      * Check that the directory belongs to my userid; if not, reject.
     303             :      *
     304             :      * This check is an essential part of the interlock that prevents two
     305             :      * postmasters from starting in the same directory (see CreateLockFile()).
     306             :      * Do not remove or weaken it.
     307             :      *
     308             :      * XXX can we safely enable this check on Windows?
     309             :      */
     310             : #if !defined(WIN32) && !defined(__CYGWIN__)
     311        2180 :     if (stat_buf.st_uid != geteuid())
     312           0 :         ereport(FATAL,
     313             :                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
     314             :                  errmsg("data directory \"%s\" has wrong ownership",
     315             :                         DataDir),
     316             :                  errhint("The server must be started by the user that owns the data directory.")));
     317             : #endif
     318             : 
     319             :     /*
     320             :      * Check if the directory has correct permissions.  If not, reject.
     321             :      *
     322             :      * Only two possible modes are allowed, 0700 and 0750.  The latter mode
     323             :      * indicates that group read/execute should be allowed on all newly
     324             :      * created files and directories.
     325             :      *
     326             :      * XXX temporarily suppress check when on Windows, because there may not
     327             :      * be proper support for Unix-y file permissions.  Need to think of a
     328             :      * reasonable check to apply on Windows.
     329             :      */
     330             : #if !defined(WIN32) && !defined(__CYGWIN__)
     331        2180 :     if (stat_buf.st_mode & PG_MODE_MASK_GROUP)
     332           0 :         ereport(FATAL,
     333             :                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
     334             :                  errmsg("data directory \"%s\" has invalid permissions",
     335             :                         DataDir),
     336             :                  errdetail("Permissions should be u=rwx (0700) or u=rwx,g=rx (0750).")));
     337             : #endif
     338             : 
     339             :     /*
     340             :      * Reset creation modes and mask based on the mode of the data directory.
     341             :      *
     342             :      * The mask was set earlier in startup to disallow group permissions on
     343             :      * newly created files and directories.  However, if group read/execute
     344             :      * are present on the data directory then modify the create modes and mask
     345             :      * to allow group read/execute on newly created files and directories and
     346             :      * set the data_directory_mode GUC.
     347             :      *
     348             :      * Suppress when on Windows, because there may not be proper support for
     349             :      * Unix-y file permissions.
     350             :      */
     351             : #if !defined(WIN32) && !defined(__CYGWIN__)
     352        2180 :     SetDataDirectoryCreatePerm(stat_buf.st_mode);
     353             : 
     354        2180 :     umask(pg_mode_mask);
     355        2180 :     data_directory_mode = pg_dir_create_mode;
     356             : #endif
     357             : 
     358             :     /* Check for PG_VERSION */
     359        2180 :     ValidatePgVersion(DataDir);
     360        2180 : }
     361             : 
     362             : /*
     363             :  * Set data directory, but make sure it's an absolute path.  Use this,
     364             :  * never set DataDir directly.
     365             :  */
     366             : void
     367        2184 : SetDataDir(const char *dir)
     368             : {
     369             :     char       *new;
     370             : 
     371             :     AssertArg(dir);
     372             : 
     373             :     /* If presented path is relative, convert to absolute */
     374        2184 :     new = make_absolute_path(dir);
     375             : 
     376        2184 :     if (DataDir)
     377           0 :         free(DataDir);
     378        2184 :     DataDir = new;
     379        2184 : }
     380             : 
     381             : /*
     382             :  * Change working directory to DataDir.  Most of the postmaster and backend
     383             :  * code assumes that we are in DataDir so it can use relative paths to access
     384             :  * stuff in and under the data directory.  For convenience during path
     385             :  * setup, however, we don't force the chdir to occur during SetDataDir.
     386             :  */
     387             : void
     388        2180 : ChangeToDataDir(void)
     389             : {
     390             :     AssertState(DataDir);
     391             : 
     392        2180 :     if (chdir(DataDir) < 0)
     393           0 :         ereport(FATAL,
     394             :                 (errcode_for_file_access(),
     395             :                  errmsg("could not change directory to \"%s\": %m",
     396             :                         DataDir)));
     397        2180 : }
     398             : 
     399             : 
     400             : /* ----------------------------------------------------------------
     401             :  *  User ID state
     402             :  *
     403             :  * We have to track several different values associated with the concept
     404             :  * of "user ID".
     405             :  *
     406             :  * AuthenticatedUserId is determined at connection start and never changes.
     407             :  *
     408             :  * SessionUserId is initially the same as AuthenticatedUserId, but can be
     409             :  * changed by SET SESSION AUTHORIZATION (if AuthenticatedUserIsSuperuser).
     410             :  * This is the ID reported by the SESSION_USER SQL function.
     411             :  *
     412             :  * OuterUserId is the current user ID in effect at the "outer level" (outside
     413             :  * any transaction or function).  This is initially the same as SessionUserId,
     414             :  * but can be changed by SET ROLE to any role that SessionUserId is a
     415             :  * member of.  (XXX rename to something like CurrentRoleId?)
     416             :  *
     417             :  * CurrentUserId is the current effective user ID; this is the one to use
     418             :  * for all normal permissions-checking purposes.  At outer level this will
     419             :  * be the same as OuterUserId, but it changes during calls to SECURITY
     420             :  * DEFINER functions, as well as locally in some specialized commands.
     421             :  *
     422             :  * SecurityRestrictionContext holds flags indicating reason(s) for changing
     423             :  * CurrentUserId.  In some cases we need to lock down operations that are
     424             :  * not directly controlled by privilege settings, and this provides a
     425             :  * convenient way to do it.
     426             :  * ----------------------------------------------------------------
     427             :  */
     428             : static Oid  AuthenticatedUserId = InvalidOid;
     429             : static Oid  SessionUserId = InvalidOid;
     430             : static Oid  OuterUserId = InvalidOid;
     431             : static Oid  CurrentUserId = InvalidOid;
     432             : 
     433             : /* We also have to remember the superuser state of some of these levels */
     434             : static bool AuthenticatedUserIsSuperuser = false;
     435             : static bool SessionUserIsSuperuser = false;
     436             : 
     437             : static int  SecurityRestrictionContext = 0;
     438             : 
     439             : /* We also remember if a SET ROLE is currently active */
     440             : static bool SetRoleIsActive = false;
     441             : 
     442             : /*
     443             :  * GetUserId - get the current effective user ID.
     444             :  *
     445             :  * Note: there's no SetUserId() anymore; use SetUserIdAndSecContext().
     446             :  */
     447             : Oid
     448     7895868 : GetUserId(void)
     449             : {
     450             :     AssertState(OidIsValid(CurrentUserId));
     451     7895868 :     return CurrentUserId;
     452             : }
     453             : 
     454             : 
     455             : /*
     456             :  * GetOuterUserId/SetOuterUserId - get/set the outer-level user ID.
     457             :  */
     458             : Oid
     459         656 : GetOuterUserId(void)
     460             : {
     461             :     AssertState(OidIsValid(OuterUserId));
     462         656 :     return OuterUserId;
     463             : }
     464             : 
     465             : 
     466             : static void
     467        2404 : SetOuterUserId(Oid userid)
     468             : {
     469             :     AssertState(SecurityRestrictionContext == 0);
     470             :     AssertArg(OidIsValid(userid));
     471        2404 :     OuterUserId = userid;
     472             : 
     473             :     /* We force the effective user ID to match, too */
     474        2404 :     CurrentUserId = userid;
     475        2404 : }
     476             : 
     477             : 
     478             : /*
     479             :  * GetSessionUserId/SetSessionUserId - get/set the session user ID.
     480             :  */
     481             : Oid
     482       21068 : GetSessionUserId(void)
     483             : {
     484             :     AssertState(OidIsValid(SessionUserId));
     485       21068 :     return SessionUserId;
     486             : }
     487             : 
     488             : 
     489             : static void
     490       23316 : SetSessionUserId(Oid userid, bool is_superuser)
     491             : {
     492             :     AssertState(SecurityRestrictionContext == 0);
     493             :     AssertArg(OidIsValid(userid));
     494       23316 :     SessionUserId = userid;
     495       23316 :     SessionUserIsSuperuser = is_superuser;
     496       23316 :     SetRoleIsActive = false;
     497             : 
     498             :     /* We force the effective user IDs to match, too */
     499       23316 :     OuterUserId = userid;
     500       23316 :     CurrentUserId = userid;
     501       23316 : }
     502             : 
     503             : /*
     504             :  * GetAuthenticatedUserId - get the authenticated user ID
     505             :  */
     506             : Oid
     507         470 : GetAuthenticatedUserId(void)
     508             : {
     509             :     AssertState(OidIsValid(AuthenticatedUserId));
     510         470 :     return AuthenticatedUserId;
     511             : }
     512             : 
     513             : 
     514             : /*
     515             :  * GetUserIdAndSecContext/SetUserIdAndSecContext - get/set the current user ID
     516             :  * and the SecurityRestrictionContext flags.
     517             :  *
     518             :  * Currently there are three valid bits in SecurityRestrictionContext:
     519             :  *
     520             :  * SECURITY_LOCAL_USERID_CHANGE indicates that we are inside an operation
     521             :  * that is temporarily changing CurrentUserId via these functions.  This is
     522             :  * needed to indicate that the actual value of CurrentUserId is not in sync
     523             :  * with guc.c's internal state, so SET ROLE has to be disallowed.
     524             :  *
     525             :  * SECURITY_RESTRICTED_OPERATION indicates that we are inside an operation
     526             :  * that does not wish to trust called user-defined functions at all.  This
     527             :  * bit prevents not only SET ROLE, but various other changes of session state
     528             :  * that normally is unprotected but might possibly be used to subvert the
     529             :  * calling session later.  An example is replacing an existing prepared
     530             :  * statement with new code, which will then be executed with the outer
     531             :  * session's permissions when the prepared statement is next used.  Since
     532             :  * these restrictions are fairly draconian, we apply them only in contexts
     533             :  * where the called functions are really supposed to be side-effect-free
     534             :  * anyway, such as VACUUM/ANALYZE/REINDEX.
     535             :  *
     536             :  * SECURITY_NOFORCE_RLS indicates that we are inside an operation which should
     537             :  * ignore the FORCE ROW LEVEL SECURITY per-table indication.  This is used to
     538             :  * ensure that FORCE RLS does not mistakenly break referential integrity
     539             :  * checks.  Note that this is intentionally only checked when running as the
     540             :  * owner of the table (which should always be the case for referential
     541             :  * integrity checks).
     542             :  *
     543             :  * Unlike GetUserId, GetUserIdAndSecContext does *not* Assert that the current
     544             :  * value of CurrentUserId is valid; nor does SetUserIdAndSecContext require
     545             :  * the new value to be valid.  In fact, these routines had better not
     546             :  * ever throw any kind of error.  This is because they are used by
     547             :  * StartTransaction and AbortTransaction to save/restore the settings,
     548             :  * and during the first transaction within a backend, the value to be saved
     549             :  * and perhaps restored is indeed invalid.  We have to be able to get
     550             :  * through AbortTransaction without asserting in case InitPostgres fails.
     551             :  */
     552             : void
     553      665788 : GetUserIdAndSecContext(Oid *userid, int *sec_context)
     554             : {
     555      665788 :     *userid = CurrentUserId;
     556      665788 :     *sec_context = SecurityRestrictionContext;
     557      665788 : }
     558             : 
     559             : void
     560      348748 : SetUserIdAndSecContext(Oid userid, int sec_context)
     561             : {
     562      348748 :     CurrentUserId = userid;
     563      348748 :     SecurityRestrictionContext = sec_context;
     564      348748 : }
     565             : 
     566             : 
     567             : /*
     568             :  * InLocalUserIdChange - are we inside a local change of CurrentUserId?
     569             :  */
     570             : bool
     571       13366 : InLocalUserIdChange(void)
     572             : {
     573       13366 :     return (SecurityRestrictionContext & SECURITY_LOCAL_USERID_CHANGE) != 0;
     574             : }
     575             : 
     576             : /*
     577             :  * InSecurityRestrictedOperation - are we inside a security-restricted command?
     578             :  */
     579             : bool
     580       20876 : InSecurityRestrictedOperation(void)
     581             : {
     582       20876 :     return (SecurityRestrictionContext & SECURITY_RESTRICTED_OPERATION) != 0;
     583             : }
     584             : 
     585             : /*
     586             :  * InNoForceRLSOperation - are we ignoring FORCE ROW LEVEL SECURITY ?
     587             :  */
     588             : bool
     589         116 : InNoForceRLSOperation(void)
     590             : {
     591         116 :     return (SecurityRestrictionContext & SECURITY_NOFORCE_RLS) != 0;
     592             : }
     593             : 
     594             : 
     595             : /*
     596             :  * These are obsolete versions of Get/SetUserIdAndSecContext that are
     597             :  * only provided for bug-compatibility with some rather dubious code in
     598             :  * pljava.  We allow the userid to be set, but only when not inside a
     599             :  * security restriction context.
     600             :  */
     601             : void
     602           0 : GetUserIdAndContext(Oid *userid, bool *sec_def_context)
     603             : {
     604           0 :     *userid = CurrentUserId;
     605           0 :     *sec_def_context = InLocalUserIdChange();
     606           0 : }
     607             : 
     608             : void
     609           0 : SetUserIdAndContext(Oid userid, bool sec_def_context)
     610             : {
     611             :     /* We throw the same error SET ROLE would. */
     612           0 :     if (InSecurityRestrictedOperation())
     613           0 :         ereport(ERROR,
     614             :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     615             :                  errmsg("cannot set parameter \"%s\" within security-restricted operation",
     616             :                         "role")));
     617           0 :     CurrentUserId = userid;
     618           0 :     if (sec_def_context)
     619           0 :         SecurityRestrictionContext |= SECURITY_LOCAL_USERID_CHANGE;
     620             :     else
     621           0 :         SecurityRestrictionContext &= ~SECURITY_LOCAL_USERID_CHANGE;
     622           0 : }
     623             : 
     624             : 
     625             : /*
     626             :  * Check whether specified role has explicit REPLICATION privilege
     627             :  */
     628             : bool
     629          36 : has_rolreplication(Oid roleid)
     630             : {
     631          36 :     bool        result = false;
     632             :     HeapTuple   utup;
     633             : 
     634          36 :     utup = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid));
     635          36 :     if (HeapTupleIsValid(utup))
     636             :     {
     637          36 :         result = ((Form_pg_authid) GETSTRUCT(utup))->rolreplication;
     638          36 :         ReleaseSysCache(utup);
     639             :     }
     640          36 :     return result;
     641             : }
     642             : 
     643             : /*
     644             :  * Initialize user identity during normal backend startup
     645             :  */
     646             : void
     647        9546 : InitializeSessionUserId(const char *rolename, Oid roleid)
     648             : {
     649             :     HeapTuple   roleTup;
     650             :     Form_pg_authid rform;
     651             :     char       *rname;
     652             : 
     653             :     /*
     654             :      * Don't do scans if we're bootstrapping, none of the system catalogs
     655             :      * exist yet, and they should be owned by postgres anyway.
     656             :      */
     657             :     AssertState(!IsBootstrapProcessingMode());
     658             : 
     659             :     /* call only once */
     660             :     AssertState(!OidIsValid(AuthenticatedUserId));
     661             : 
     662             :     /*
     663             :      * Make sure syscache entries are flushed for recent catalog changes. This
     664             :      * allows us to find roles that were created on-the-fly during
     665             :      * authentication.
     666             :      */
     667        9546 :     AcceptInvalidationMessages();
     668             : 
     669        9546 :     if (rolename != NULL)
     670             :     {
     671        7816 :         roleTup = SearchSysCache1(AUTHNAME, PointerGetDatum(rolename));
     672        7816 :         if (!HeapTupleIsValid(roleTup))
     673           2 :             ereport(FATAL,
     674             :                     (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
     675             :                      errmsg("role \"%s\" does not exist", rolename)));
     676             :     }
     677             :     else
     678             :     {
     679        1730 :         roleTup = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid));
     680        1730 :         if (!HeapTupleIsValid(roleTup))
     681           0 :             ereport(FATAL,
     682             :                     (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
     683             :                      errmsg("role with OID %u does not exist", roleid)));
     684             :     }
     685             : 
     686        9544 :     rform = (Form_pg_authid) GETSTRUCT(roleTup);
     687        9544 :     roleid = rform->oid;
     688        9544 :     rname = NameStr(rform->rolname);
     689             : 
     690        9544 :     AuthenticatedUserId = roleid;
     691        9544 :     AuthenticatedUserIsSuperuser = rform->rolsuper;
     692             : 
     693             :     /* This sets OuterUserId/CurrentUserId too */
     694        9544 :     SetSessionUserId(roleid, AuthenticatedUserIsSuperuser);
     695             : 
     696             :     /* Also mark our PGPROC entry with the authenticated user id */
     697             :     /* (We assume this is an atomic store so no lock is needed) */
     698        9544 :     MyProc->roleId = roleid;
     699             : 
     700             :     /*
     701             :      * These next checks are not enforced when in standalone mode, so that
     702             :      * there is a way to recover from sillinesses like "UPDATE pg_authid SET
     703             :      * rolcanlogin = false;".
     704             :      */
     705        9544 :     if (IsUnderPostmaster)
     706             :     {
     707             :         /*
     708             :          * Is role allowed to login at all?
     709             :          */
     710        9544 :         if (!rform->rolcanlogin)
     711           0 :             ereport(FATAL,
     712             :                     (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
     713             :                      errmsg("role \"%s\" is not permitted to log in",
     714             :                             rname)));
     715             : 
     716             :         /*
     717             :          * Check connection limit for this role.
     718             :          *
     719             :          * There is a race condition here --- we create our PGPROC before
     720             :          * checking for other PGPROCs.  If two backends did this at about the
     721             :          * same time, they might both think they were over the limit, while
     722             :          * ideally one should succeed and one fail.  Getting that to work
     723             :          * exactly seems more trouble than it is worth, however; instead we
     724             :          * just document that the connection limit is approximate.
     725             :          */
     726        9544 :         if (rform->rolconnlimit >= 0 &&
     727           0 :             !AuthenticatedUserIsSuperuser &&
     728           0 :             CountUserBackends(roleid) > rform->rolconnlimit)
     729           0 :             ereport(FATAL,
     730             :                     (errcode(ERRCODE_TOO_MANY_CONNECTIONS),
     731             :                      errmsg("too many connections for role \"%s\"",
     732             :                             rname)));
     733             :     }
     734             : 
     735             :     /* Record username and superuser status as GUC settings too */
     736        9544 :     SetConfigOption("session_authorization", rname,
     737             :                     PGC_BACKEND, PGC_S_OVERRIDE);
     738        9544 :     SetConfigOption("is_superuser",
     739        9544 :                     AuthenticatedUserIsSuperuser ? "on" : "off",
     740             :                     PGC_INTERNAL, PGC_S_OVERRIDE);
     741             : 
     742        9544 :     ReleaseSysCache(roleTup);
     743        9544 : }
     744             : 
     745             : 
     746             : /*
     747             :  * Initialize user identity during special backend startup
     748             :  */
     749             : void
     750        1166 : InitializeSessionUserIdStandalone(void)
     751             : {
     752             :     /*
     753             :      * This function should only be called in single-user mode, in autovacuum
     754             :      * workers, and in background workers.
     755             :      */
     756             :     AssertState(!IsUnderPostmaster || IsAutoVacuumWorkerProcess() || IsBackgroundWorker);
     757             : 
     758             :     /* call only once */
     759             :     AssertState(!OidIsValid(AuthenticatedUserId));
     760             : 
     761        1166 :     AuthenticatedUserId = BOOTSTRAP_SUPERUSERID;
     762        1166 :     AuthenticatedUserIsSuperuser = true;
     763             : 
     764        1166 :     SetSessionUserId(BOOTSTRAP_SUPERUSERID, true);
     765        1166 : }
     766             : 
     767             : 
     768             : /*
     769             :  * Change session auth ID while running
     770             :  *
     771             :  * Only a superuser may set auth ID to something other than himself.  Note
     772             :  * that in case of multiple SETs in a single session, the original userid's
     773             :  * superuserness is what matters.  But we set the GUC variable is_superuser
     774             :  * to indicate whether the *current* session userid is a superuser.
     775             :  *
     776             :  * Note: this is not an especially clean place to do the permission check.
     777             :  * It's OK because the check does not require catalog access and can't
     778             :  * fail during an end-of-transaction GUC reversion, but we may someday
     779             :  * have to push it up into assign_session_authorization.
     780             :  */
     781             : void
     782       12606 : SetSessionAuthorization(Oid userid, bool is_superuser)
     783             : {
     784             :     /* Must have authenticated already, else can't make permission check */
     785             :     AssertState(OidIsValid(AuthenticatedUserId));
     786             : 
     787       12606 :     if (userid != AuthenticatedUserId &&
     788        1116 :         !AuthenticatedUserIsSuperuser)
     789           0 :         ereport(ERROR,
     790             :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     791             :                  errmsg("permission denied to set session authorization")));
     792             : 
     793       12606 :     SetSessionUserId(userid, is_superuser);
     794             : 
     795       12606 :     SetConfigOption("is_superuser",
     796             :                     is_superuser ? "on" : "off",
     797             :                     PGC_INTERNAL, PGC_S_OVERRIDE);
     798       12606 : }
     799             : 
     800             : /*
     801             :  * Report current role id
     802             :  *      This follows the semantics of SET ROLE, ie return the outer-level ID
     803             :  *      not the current effective ID, and return InvalidOid when the setting
     804             :  *      is logically SET ROLE NONE.
     805             :  */
     806             : Oid
     807         502 : GetCurrentRoleId(void)
     808             : {
     809         502 :     if (SetRoleIsActive)
     810           0 :         return OuterUserId;
     811             :     else
     812         502 :         return InvalidOid;
     813             : }
     814             : 
     815             : /*
     816             :  * Change Role ID while running (SET ROLE)
     817             :  *
     818             :  * If roleid is InvalidOid, we are doing SET ROLE NONE: revert to the
     819             :  * session user authorization.  In this case the is_superuser argument
     820             :  * is ignored.
     821             :  *
     822             :  * When roleid is not InvalidOid, the caller must have checked whether
     823             :  * the session user has permission to become that role.  (We cannot check
     824             :  * here because this routine must be able to execute in a failed transaction
     825             :  * to restore a prior value of the ROLE GUC variable.)
     826             :  */
     827             : void
     828        4588 : SetCurrentRoleId(Oid roleid, bool is_superuser)
     829             : {
     830             :     /*
     831             :      * Get correct info if it's SET ROLE NONE
     832             :      *
     833             :      * If SessionUserId hasn't been set yet, just do nothing --- the eventual
     834             :      * SetSessionUserId call will fix everything.  This is needed since we
     835             :      * will get called during GUC initialization.
     836             :      */
     837        4588 :     if (!OidIsValid(roleid))
     838             :     {
     839        4090 :         if (!OidIsValid(SessionUserId))
     840        2184 :             return;
     841             : 
     842        1906 :         roleid = SessionUserId;
     843        1906 :         is_superuser = SessionUserIsSuperuser;
     844             : 
     845        1906 :         SetRoleIsActive = false;
     846             :     }
     847             :     else
     848         498 :         SetRoleIsActive = true;
     849             : 
     850        2404 :     SetOuterUserId(roleid);
     851             : 
     852        2404 :     SetConfigOption("is_superuser",
     853             :                     is_superuser ? "on" : "off",
     854             :                     PGC_INTERNAL, PGC_S_OVERRIDE);
     855             : }
     856             : 
     857             : 
     858             : /*
     859             :  * Get user name from user oid, returns NULL for nonexistent roleid if noerr
     860             :  * is true.
     861             :  */
     862             : char *
     863        4504 : GetUserNameFromId(Oid roleid, bool noerr)
     864             : {
     865             :     HeapTuple   tuple;
     866             :     char       *result;
     867             : 
     868        4504 :     tuple = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid));
     869        4504 :     if (!HeapTupleIsValid(tuple))
     870             :     {
     871           0 :         if (!noerr)
     872           0 :             ereport(ERROR,
     873             :                     (errcode(ERRCODE_UNDEFINED_OBJECT),
     874             :                      errmsg("invalid role OID: %u", roleid)));
     875           0 :         result = NULL;
     876             :     }
     877             :     else
     878             :     {
     879        4504 :         result = pstrdup(NameStr(((Form_pg_authid) GETSTRUCT(tuple))->rolname));
     880        4504 :         ReleaseSysCache(tuple);
     881             :     }
     882        4504 :     return result;
     883             : }
     884             : 
     885             : 
     886             : /*-------------------------------------------------------------------------
     887             :  *              Interlock-file support
     888             :  *
     889             :  * These routines are used to create both a data-directory lockfile
     890             :  * ($DATADIR/postmaster.pid) and Unix-socket-file lockfiles ($SOCKFILE.lock).
     891             :  * Both kinds of files contain the same info initially, although we can add
     892             :  * more information to a data-directory lockfile after it's created, using
     893             :  * AddToDataDirLockFile().  See pidfile.h for documentation of the contents
     894             :  * of these lockfiles.
     895             :  *
     896             :  * On successful lockfile creation, a proc_exit callback to remove the
     897             :  * lockfile is automatically created.
     898             :  *-------------------------------------------------------------------------
     899             :  */
     900             : 
     901             : /*
     902             :  * proc_exit callback to remove lockfiles.
     903             :  */
     904             : static void
     905        2170 : UnlinkLockFiles(int status, Datum arg)
     906             : {
     907             :     ListCell   *l;
     908             : 
     909        5048 :     foreach(l, lock_files)
     910             :     {
     911        2878 :         char       *curfile = (char *) lfirst(l);
     912             : 
     913        2878 :         unlink(curfile);
     914             :         /* Should we complain if the unlink fails? */
     915             :     }
     916             :     /* Since we're about to exit, no need to reclaim storage */
     917        2170 :     lock_files = NIL;
     918             : 
     919             :     /*
     920             :      * Lock file removal should always be the last externally visible action
     921             :      * of a postmaster or standalone backend, while we won't come here at all
     922             :      * when exiting postmaster child processes.  Therefore, this is a good
     923             :      * place to log completion of shutdown.  We could alternatively teach
     924             :      * proc_exit() to do it, but that seems uglier.  In a standalone backend,
     925             :      * use NOTICE elevel to be less chatty.
     926             :      */
     927        2170 :     ereport(IsPostmasterEnvironment ? LOG : NOTICE,
     928             :             (errmsg("database system is shut down")));
     929        2170 : }
     930             : 
     931             : /*
     932             :  * Create a lockfile.
     933             :  *
     934             :  * filename is the path name of the lockfile to create.
     935             :  * amPostmaster is used to determine how to encode the output PID.
     936             :  * socketDir is the Unix socket directory path to include (possibly empty).
     937             :  * isDDLock and refName are used to determine what error message to produce.
     938             :  */
     939             : static void
     940        2894 : CreateLockFile(const char *filename, bool amPostmaster,
     941             :                const char *socketDir,
     942             :                bool isDDLock, const char *refName)
     943             : {
     944             :     int         fd;
     945             :     char        buffer[MAXPGPATH * 2 + 256];
     946             :     int         ntries;
     947             :     int         len;
     948             :     int         encoded_pid;
     949             :     pid_t       other_pid;
     950             :     pid_t       my_pid,
     951             :                 my_p_pid,
     952             :                 my_gp_pid;
     953             :     const char *envvar;
     954             : 
     955             :     /*
     956             :      * If the PID in the lockfile is our own PID or our parent's or
     957             :      * grandparent's PID, then the file must be stale (probably left over from
     958             :      * a previous system boot cycle).  We need to check this because of the
     959             :      * likelihood that a reboot will assign exactly the same PID as we had in
     960             :      * the previous reboot, or one that's only one or two counts larger and
     961             :      * hence the lockfile's PID now refers to an ancestor shell process.  We
     962             :      * allow pg_ctl to pass down its parent shell PID (our grandparent PID)
     963             :      * via the environment variable PG_GRANDPARENT_PID; this is so that
     964             :      * launching the postmaster via pg_ctl can be just as reliable as
     965             :      * launching it directly.  There is no provision for detecting
     966             :      * further-removed ancestor processes, but if the init script is written
     967             :      * carefully then all but the immediate parent shell will be root-owned
     968             :      * processes and so the kill test will fail with EPERM.  Note that we
     969             :      * cannot get a false negative this way, because an existing postmaster
     970             :      * would surely never launch a competing postmaster or pg_ctl process
     971             :      * directly.
     972             :      */
     973        2894 :     my_pid = getpid();
     974             : 
     975             : #ifndef WIN32
     976        2894 :     my_p_pid = getppid();
     977             : #else
     978             : 
     979             :     /*
     980             :      * Windows hasn't got getppid(), but doesn't need it since it's not using
     981             :      * real kill() either...
     982             :      */
     983             :     my_p_pid = 0;
     984             : #endif
     985             : 
     986        2894 :     envvar = getenv("PG_GRANDPARENT_PID");
     987        2894 :     if (envvar)
     988        1178 :         my_gp_pid = atoi(envvar);
     989             :     else
     990        1716 :         my_gp_pid = 0;
     991             : 
     992             :     /*
     993             :      * We need a loop here because of race conditions.  But don't loop forever
     994             :      * (for example, a non-writable $PGDATA directory might cause a failure
     995             :      * that won't go away).  100 tries seems like plenty.
     996             :      */
     997        2894 :     for (ntries = 0;; ntries++)
     998             :     {
     999             :         /*
    1000             :          * Try to create the lock file --- O_EXCL makes this atomic.
    1001             :          *
    1002             :          * Think not to make the file protection weaker than 0600/0640.  See
    1003             :          * comments below.
    1004             :          */
    1005        2904 :         fd = open(filename, O_RDWR | O_CREAT | O_EXCL, pg_file_create_mode);
    1006        2904 :         if (fd >= 0)
    1007        2890 :             break;              /* Success; exit the retry loop */
    1008             : 
    1009             :         /*
    1010             :          * Couldn't create the pid file. Probably it already exists.
    1011             :          */
    1012          14 :         if ((errno != EEXIST && errno != EACCES) || ntries > 100)
    1013           0 :             ereport(FATAL,
    1014             :                     (errcode_for_file_access(),
    1015             :                      errmsg("could not create lock file \"%s\": %m",
    1016             :                             filename)));
    1017             : 
    1018             :         /*
    1019             :          * Read the file to get the old owner's PID.  Note race condition
    1020             :          * here: file might have been deleted since we tried to create it.
    1021             :          */
    1022          14 :         fd = open(filename, O_RDONLY, pg_file_create_mode);
    1023          14 :         if (fd < 0)
    1024             :         {
    1025           0 :             if (errno == ENOENT)
    1026           0 :                 continue;       /* race condition; try again */
    1027           0 :             ereport(FATAL,
    1028             :                     (errcode_for_file_access(),
    1029             :                      errmsg("could not open lock file \"%s\": %m",
    1030             :                             filename)));
    1031             :         }
    1032          14 :         pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_CREATE_READ);
    1033          14 :         if ((len = read(fd, buffer, sizeof(buffer) - 1)) < 0)
    1034           0 :             ereport(FATAL,
    1035             :                     (errcode_for_file_access(),
    1036             :                      errmsg("could not read lock file \"%s\": %m",
    1037             :                             filename)));
    1038          14 :         pgstat_report_wait_end();
    1039          14 :         close(fd);
    1040             : 
    1041          14 :         if (len == 0)
    1042             :         {
    1043           0 :             ereport(FATAL,
    1044             :                     (errcode(ERRCODE_LOCK_FILE_EXISTS),
    1045             :                      errmsg("lock file \"%s\" is empty", filename),
    1046             :                      errhint("Either another server is starting, or the lock file is the remnant of a previous server startup crash.")));
    1047             :         }
    1048             : 
    1049          14 :         buffer[len] = '\0';
    1050          14 :         encoded_pid = atoi(buffer);
    1051             : 
    1052             :         /* if pid < 0, the pid is for postgres, not postmaster */
    1053          14 :         other_pid = (pid_t) (encoded_pid < 0 ? -encoded_pid : encoded_pid);
    1054             : 
    1055          14 :         if (other_pid <= 0)
    1056           0 :             elog(FATAL, "bogus data in lock file \"%s\": \"%s\"",
    1057             :                  filename, buffer);
    1058             : 
    1059             :         /*
    1060             :          * Check to see if the other process still exists
    1061             :          *
    1062             :          * Per discussion above, my_pid, my_p_pid, and my_gp_pid can be
    1063             :          * ignored as false matches.
    1064             :          *
    1065             :          * Normally kill() will fail with ESRCH if the given PID doesn't
    1066             :          * exist.
    1067             :          *
    1068             :          * We can treat the EPERM-error case as okay because that error
    1069             :          * implies that the existing process has a different userid than we
    1070             :          * do, which means it cannot be a competing postmaster.  A postmaster
    1071             :          * cannot successfully attach to a data directory owned by a userid
    1072             :          * other than its own, as enforced in checkDataDir(). Also, since we
    1073             :          * create the lockfiles mode 0600/0640, we'd have failed above if the
    1074             :          * lockfile belonged to another userid --- which means that whatever
    1075             :          * process kill() is reporting about isn't the one that made the
    1076             :          * lockfile.  (NOTE: this last consideration is the only one that
    1077             :          * keeps us from blowing away a Unix socket file belonging to an
    1078             :          * instance of Postgres being run by someone else, at least on
    1079             :          * machines where /tmp hasn't got a stickybit.)
    1080             :          */
    1081          14 :         if (other_pid != my_pid && other_pid != my_p_pid &&
    1082             :             other_pid != my_gp_pid)
    1083             :         {
    1084          14 :             if (kill(other_pid, 0) == 0 ||
    1085          10 :                 (errno != ESRCH && errno != EPERM))
    1086             :             {
    1087             :                 /* lockfile belongs to a live process */
    1088           4 :                 ereport(FATAL,
    1089             :                         (errcode(ERRCODE_LOCK_FILE_EXISTS),
    1090             :                          errmsg("lock file \"%s\" already exists",
    1091             :                                 filename),
    1092             :                          isDDLock ?
    1093             :                          (encoded_pid < 0 ?
    1094             :                           errhint("Is another postgres (PID %d) running in data directory \"%s\"?",
    1095             :                                   (int) other_pid, refName) :
    1096             :                           errhint("Is another postmaster (PID %d) running in data directory \"%s\"?",
    1097             :                                   (int) other_pid, refName)) :
    1098             :                          (encoded_pid < 0 ?
    1099             :                           errhint("Is another postgres (PID %d) using socket file \"%s\"?",
    1100             :                                   (int) other_pid, refName) :
    1101             :                           errhint("Is another postmaster (PID %d) using socket file \"%s\"?",
    1102             :                                   (int) other_pid, refName))));
    1103             :             }
    1104             :         }
    1105             : 
    1106             :         /*
    1107             :          * No, the creating process did not exist.  However, it could be that
    1108             :          * the postmaster crashed (or more likely was kill -9'd by a clueless
    1109             :          * admin) but has left orphan backends behind.  Check for this by
    1110             :          * looking to see if there is an associated shmem segment that is
    1111             :          * still in use.
    1112             :          *
    1113             :          * Note: because postmaster.pid is written in multiple steps, we might
    1114             :          * not find the shmem ID values in it; we can't treat that as an
    1115             :          * error.
    1116             :          */
    1117          10 :         if (isDDLock)
    1118             :         {
    1119           4 :             char       *ptr = buffer;
    1120             :             unsigned long id1,
    1121             :                         id2;
    1122             :             int         lineno;
    1123             : 
    1124          28 :             for (lineno = 1; lineno < LOCK_FILE_LINE_SHMEM_KEY; lineno++)
    1125             :             {
    1126          24 :                 if ((ptr = strchr(ptr, '\n')) == NULL)
    1127           0 :                     break;
    1128          24 :                 ptr++;
    1129             :             }
    1130             : 
    1131           4 :             if (ptr != NULL &&
    1132           4 :                 sscanf(ptr, "%lu %lu", &id1, &id2) == 2)
    1133             :             {
    1134           4 :                 if (PGSharedMemoryIsInUse(id1, id2))
    1135           0 :                     ereport(FATAL,
    1136             :                             (errcode(ERRCODE_LOCK_FILE_EXISTS),
    1137             :                              errmsg("pre-existing shared memory block (key %lu, ID %lu) is still in use",
    1138             :                                     id1, id2),
    1139             :                              errhint("Terminate any old server processes associated with data directory \"%s\".",
    1140             :                                      refName)));
    1141             :             }
    1142             :         }
    1143             : 
    1144             :         /*
    1145             :          * Looks like nobody's home.  Unlink the file and try again to create
    1146             :          * it.  Need a loop because of possible race condition against other
    1147             :          * would-be creators.
    1148             :          */
    1149          10 :         if (unlink(filename) < 0)
    1150           0 :             ereport(FATAL,
    1151             :                     (errcode_for_file_access(),
    1152             :                      errmsg("could not remove old lock file \"%s\": %m",
    1153             :                             filename),
    1154             :                      errhint("The file seems accidentally left over, but "
    1155             :                              "it could not be removed. Please remove the file "
    1156             :                              "by hand and try again.")));
    1157             :     }
    1158             : 
    1159             :     /*
    1160             :      * Successfully created the file, now fill it.  See comment in pidfile.h
    1161             :      * about the contents.  Note that we write the same first five lines into
    1162             :      * both datadir and socket lockfiles; although more stuff may get added to
    1163             :      * the datadir lockfile later.
    1164             :      */
    1165        2890 :     snprintf(buffer, sizeof(buffer), "%d\n%s\n%ld\n%d\n%s\n",
    1166             :              amPostmaster ? (int) my_pid : -((int) my_pid),
    1167             :              DataDir,
    1168             :              (long) MyStartTime,
    1169             :              PostPortNumber,
    1170             :              socketDir);
    1171             : 
    1172             :     /*
    1173             :      * In a standalone backend, the next line (LOCK_FILE_LINE_LISTEN_ADDR)
    1174             :      * will never receive data, so fill it in as empty now.
    1175             :      */
    1176        2890 :     if (isDDLock && !amPostmaster)
    1177        1452 :         strlcat(buffer, "\n", sizeof(buffer));
    1178             : 
    1179        2890 :     errno = 0;
    1180        2890 :     pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_CREATE_WRITE);
    1181        2890 :     if (write(fd, buffer, strlen(buffer)) != strlen(buffer))
    1182             :     {
    1183           0 :         int         save_errno = errno;
    1184             : 
    1185           0 :         close(fd);
    1186           0 :         unlink(filename);
    1187             :         /* if write didn't set errno, assume problem is no disk space */
    1188           0 :         errno = save_errno ? save_errno : ENOSPC;
    1189           0 :         ereport(FATAL,
    1190             :                 (errcode_for_file_access(),
    1191             :                  errmsg("could not write lock file \"%s\": %m", filename)));
    1192             :     }
    1193        2890 :     pgstat_report_wait_end();
    1194             : 
    1195        2890 :     pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_CREATE_SYNC);
    1196        2890 :     if (pg_fsync(fd) != 0)
    1197             :     {
    1198           0 :         int         save_errno = errno;
    1199             : 
    1200           0 :         close(fd);
    1201           0 :         unlink(filename);
    1202           0 :         errno = save_errno;
    1203           0 :         ereport(FATAL,
    1204             :                 (errcode_for_file_access(),
    1205             :                  errmsg("could not write lock file \"%s\": %m", filename)));
    1206             :     }
    1207        2890 :     pgstat_report_wait_end();
    1208        2890 :     if (close(fd) != 0)
    1209             :     {
    1210           0 :         int         save_errno = errno;
    1211             : 
    1212           0 :         unlink(filename);
    1213           0 :         errno = save_errno;
    1214           0 :         ereport(FATAL,
    1215             :                 (errcode_for_file_access(),
    1216             :                  errmsg("could not write lock file \"%s\": %m", filename)));
    1217             :     }
    1218             : 
    1219             :     /*
    1220             :      * Arrange to unlink the lock file(s) at proc_exit.  If this is the first
    1221             :      * one, set up the on_proc_exit function to do it; then add this lock file
    1222             :      * to the list of files to unlink.
    1223             :      */
    1224        2890 :     if (lock_files == NIL)
    1225        2176 :         on_proc_exit(UnlinkLockFiles, 0);
    1226             : 
    1227             :     /*
    1228             :      * Use lcons so that the lock files are unlinked in reverse order of
    1229             :      * creation; this is critical!
    1230             :      */
    1231        2890 :     lock_files = lcons(pstrdup(filename), lock_files);
    1232        2890 : }
    1233             : 
    1234             : /*
    1235             :  * Create the data directory lockfile.
    1236             :  *
    1237             :  * When this is called, we must have already switched the working
    1238             :  * directory to DataDir, so we can just use a relative path.  This
    1239             :  * helps ensure that we are locking the directory we should be.
    1240             :  *
    1241             :  * Note that the socket directory path line is initially written as empty.
    1242             :  * postmaster.c will rewrite it upon creating the first Unix socket.
    1243             :  */
    1244             : void
    1245        2180 : CreateDataDirLockFile(bool amPostmaster)
    1246             : {
    1247        2180 :     CreateLockFile(DIRECTORY_LOCK_FILE, amPostmaster, "", true, DataDir);
    1248        2176 : }
    1249             : 
    1250             : /*
    1251             :  * Create a lockfile for the specified Unix socket file.
    1252             :  */
    1253             : void
    1254         714 : CreateSocketLockFile(const char *socketfile, bool amPostmaster,
    1255             :                      const char *socketDir)
    1256             : {
    1257             :     char        lockfile[MAXPGPATH];
    1258             : 
    1259         714 :     snprintf(lockfile, sizeof(lockfile), "%s.lock", socketfile);
    1260         714 :     CreateLockFile(lockfile, amPostmaster, socketDir, false, socketfile);
    1261         714 : }
    1262             : 
    1263             : /*
    1264             :  * TouchSocketLockFiles -- mark socket lock files as recently accessed
    1265             :  *
    1266             :  * This routine should be called every so often to ensure that the socket
    1267             :  * lock files have a recent mod or access date.  That saves them
    1268             :  * from being removed by overenthusiastic /tmp-directory-cleaner daemons.
    1269             :  * (Another reason we should never have put the socket file in /tmp...)
    1270             :  */
    1271             : void
    1272           0 : TouchSocketLockFiles(void)
    1273             : {
    1274             :     ListCell   *l;
    1275             : 
    1276           0 :     foreach(l, lock_files)
    1277             :     {
    1278           0 :         char       *socketLockFile = (char *) lfirst(l);
    1279             : 
    1280             :         /* No need to touch the data directory lock file, we trust */
    1281           0 :         if (strcmp(socketLockFile, DIRECTORY_LOCK_FILE) == 0)
    1282           0 :             continue;
    1283             : 
    1284             :         /* we just ignore any error here */
    1285           0 :         (void) utime(socketLockFile, NULL);
    1286             :     }
    1287           0 : }
    1288             : 
    1289             : 
    1290             : /*
    1291             :  * Add (or replace) a line in the data directory lock file.
    1292             :  * The given string should not include a trailing newline.
    1293             :  *
    1294             :  * Note: because we don't truncate the file, if we were to rewrite a line
    1295             :  * with less data than it had before, there would be garbage after the last
    1296             :  * line.  While we could fix that by adding a truncate call, that would make
    1297             :  * the file update non-atomic, which we'd rather avoid.  Therefore, callers
    1298             :  * should endeavor never to shorten a line once it's been written.
    1299             :  */
    1300             : void
    1301        5788 : AddToDataDirLockFile(int target_line, const char *str)
    1302             : {
    1303             :     int         fd;
    1304             :     int         len;
    1305             :     int         lineno;
    1306             :     char       *srcptr;
    1307             :     char       *destptr;
    1308             :     char        srcbuffer[BLCKSZ];
    1309             :     char        destbuffer[BLCKSZ];
    1310             : 
    1311        5788 :     fd = open(DIRECTORY_LOCK_FILE, O_RDWR | PG_BINARY, 0);
    1312        5788 :     if (fd < 0)
    1313             :     {
    1314           0 :         ereport(LOG,
    1315             :                 (errcode_for_file_access(),
    1316             :                  errmsg("could not open file \"%s\": %m",
    1317             :                         DIRECTORY_LOCK_FILE)));
    1318           0 :         return;
    1319             :     }
    1320        5788 :     pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_ADDTODATADIR_READ);
    1321        5788 :     len = read(fd, srcbuffer, sizeof(srcbuffer) - 1);
    1322        5788 :     pgstat_report_wait_end();
    1323        5788 :     if (len < 0)
    1324             :     {
    1325           0 :         ereport(LOG,
    1326             :                 (errcode_for_file_access(),
    1327             :                  errmsg("could not read from file \"%s\": %m",
    1328             :                         DIRECTORY_LOCK_FILE)));
    1329           0 :         close(fd);
    1330           0 :         return;
    1331             :     }
    1332        5788 :     srcbuffer[len] = '\0';
    1333             : 
    1334             :     /*
    1335             :      * Advance over lines we are not supposed to rewrite, then copy them to
    1336             :      * destbuffer.
    1337             :      */
    1338        5788 :     srcptr = srcbuffer;
    1339       39844 :     for (lineno = 1; lineno < target_line; lineno++)
    1340             :     {
    1341       34772 :         char       *eol = strchr(srcptr, '\n');
    1342             : 
    1343       34772 :         if (eol == NULL)
    1344         716 :             break;              /* not enough lines in file yet */
    1345       34056 :         srcptr = eol + 1;
    1346             :     }
    1347        5788 :     memcpy(destbuffer, srcbuffer, srcptr - srcbuffer);
    1348        5788 :     destptr = destbuffer + (srcptr - srcbuffer);
    1349             : 
    1350             :     /*
    1351             :      * Fill in any missing lines before the target line, in case lines are
    1352             :      * added to the file out of order.
    1353             :      */
    1354        6504 :     for (; lineno < target_line; lineno++)
    1355             :     {
    1356         716 :         if (destptr < destbuffer + sizeof(destbuffer))
    1357         716 :             *destptr++ = '\n';
    1358             :     }
    1359             : 
    1360             :     /*
    1361             :      * Write or rewrite the target line.
    1362             :      */
    1363        5788 :     snprintf(destptr, destbuffer + sizeof(destbuffer) - destptr, "%s\n", str);
    1364        5788 :     destptr += strlen(destptr);
    1365             : 
    1366             :     /*
    1367             :      * If there are more lines in the old file, append them to destbuffer.
    1368             :      */
    1369        5788 :     if ((srcptr = strchr(srcptr, '\n')) != NULL)
    1370             :     {
    1371        2906 :         srcptr++;
    1372        2906 :         snprintf(destptr, destbuffer + sizeof(destbuffer) - destptr, "%s",
    1373             :                  srcptr);
    1374             :     }
    1375             : 
    1376             :     /*
    1377             :      * And rewrite the data.  Since we write in a single kernel call, this
    1378             :      * update should appear atomic to onlookers.
    1379             :      */
    1380        5788 :     len = strlen(destbuffer);
    1381        5788 :     errno = 0;
    1382        5788 :     pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_ADDTODATADIR_WRITE);
    1383        5788 :     if (pg_pwrite(fd, destbuffer, len, 0) != len)
    1384             :     {
    1385           0 :         pgstat_report_wait_end();
    1386             :         /* if write didn't set errno, assume problem is no disk space */
    1387           0 :         if (errno == 0)
    1388           0 :             errno = ENOSPC;
    1389           0 :         ereport(LOG,
    1390             :                 (errcode_for_file_access(),
    1391             :                  errmsg("could not write to file \"%s\": %m",
    1392             :                         DIRECTORY_LOCK_FILE)));
    1393           0 :         close(fd);
    1394           0 :         return;
    1395             :     }
    1396        5788 :     pgstat_report_wait_end();
    1397        5788 :     pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_ADDTODATADIR_SYNC);
    1398        5788 :     if (pg_fsync(fd) != 0)
    1399             :     {
    1400           0 :         ereport(LOG,
    1401             :                 (errcode_for_file_access(),
    1402             :                  errmsg("could not write to file \"%s\": %m",
    1403             :                         DIRECTORY_LOCK_FILE)));
    1404             :     }
    1405        5788 :     pgstat_report_wait_end();
    1406        5788 :     if (close(fd) != 0)
    1407             :     {
    1408           0 :         ereport(LOG,
    1409             :                 (errcode_for_file_access(),
    1410             :                  errmsg("could not write to file \"%s\": %m",
    1411             :                         DIRECTORY_LOCK_FILE)));
    1412             :     }
    1413             : }
    1414             : 
    1415             : 
    1416             : /*
    1417             :  * Recheck that the data directory lock file still exists with expected
    1418             :  * content.  Return true if the lock file appears OK, false if it isn't.
    1419             :  *
    1420             :  * We call this periodically in the postmaster.  The idea is that if the
    1421             :  * lock file has been removed or replaced by another postmaster, we should
    1422             :  * do a panic database shutdown.  Therefore, we should return true if there
    1423             :  * is any doubt: we do not want to cause a panic shutdown unnecessarily.
    1424             :  * Transient failures like EINTR or ENFILE should not cause us to fail.
    1425             :  * (If there really is something wrong, we'll detect it on a future recheck.)
    1426             :  */
    1427             : bool
    1428           8 : RecheckDataDirLockFile(void)
    1429             : {
    1430             :     int         fd;
    1431             :     int         len;
    1432             :     long        file_pid;
    1433             :     char        buffer[BLCKSZ];
    1434             : 
    1435           8 :     fd = open(DIRECTORY_LOCK_FILE, O_RDWR | PG_BINARY, 0);
    1436           8 :     if (fd < 0)
    1437             :     {
    1438             :         /*
    1439             :          * There are many foreseeable false-positive error conditions.  For
    1440             :          * safety, fail only on enumerated clearly-something-is-wrong
    1441             :          * conditions.
    1442             :          */
    1443           0 :         switch (errno)
    1444             :         {
    1445           0 :             case ENOENT:
    1446             :             case ENOTDIR:
    1447             :                 /* disaster */
    1448           0 :                 ereport(LOG,
    1449             :                         (errcode_for_file_access(),
    1450             :                          errmsg("could not open file \"%s\": %m",
    1451             :                                 DIRECTORY_LOCK_FILE)));
    1452           0 :                 return false;
    1453           0 :             default:
    1454             :                 /* non-fatal, at least for now */
    1455           0 :                 ereport(LOG,
    1456             :                         (errcode_for_file_access(),
    1457             :                          errmsg("could not open file \"%s\": %m; continuing anyway",
    1458             :                                 DIRECTORY_LOCK_FILE)));
    1459           0 :                 return true;
    1460             :         }
    1461             :     }
    1462           8 :     pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_RECHECKDATADIR_READ);
    1463           8 :     len = read(fd, buffer, sizeof(buffer) - 1);
    1464           8 :     pgstat_report_wait_end();
    1465           8 :     if (len < 0)
    1466             :     {
    1467           0 :         ereport(LOG,
    1468             :                 (errcode_for_file_access(),
    1469             :                  errmsg("could not read from file \"%s\": %m",
    1470             :                         DIRECTORY_LOCK_FILE)));
    1471           0 :         close(fd);
    1472           0 :         return true;            /* treat read failure as nonfatal */
    1473             :     }
    1474           8 :     buffer[len] = '\0';
    1475           8 :     close(fd);
    1476           8 :     file_pid = atol(buffer);
    1477           8 :     if (file_pid == getpid())
    1478           8 :         return true;            /* all is well */
    1479             : 
    1480             :     /* Trouble: someone's overwritten the lock file */
    1481           0 :     ereport(LOG,
    1482             :             (errmsg("lock file \"%s\" contains wrong PID: %ld instead of %ld",
    1483             :                     DIRECTORY_LOCK_FILE, file_pid, (long) getpid())));
    1484           0 :     return false;
    1485             : }
    1486             : 
    1487             : 
    1488             : /*-------------------------------------------------------------------------
    1489             :  *              Version checking support
    1490             :  *-------------------------------------------------------------------------
    1491             :  */
    1492             : 
    1493             : /*
    1494             :  * Determine whether the PG_VERSION file in directory `path' indicates
    1495             :  * a data version compatible with the version of this program.
    1496             :  *
    1497             :  * If compatible, return. Otherwise, ereport(FATAL).
    1498             :  */
    1499             : void
    1500       11742 : ValidatePgVersion(const char *path)
    1501             : {
    1502             :     char        full_path[MAXPGPATH];
    1503             :     FILE       *file;
    1504             :     int         ret;
    1505             :     long        file_major;
    1506             :     long        my_major;
    1507             :     char       *endptr;
    1508             :     char        file_version_string[64];
    1509       11742 :     const char *my_version_string = PG_VERSION;
    1510             : 
    1511       11742 :     my_major = strtol(my_version_string, &endptr, 10);
    1512             : 
    1513       11742 :     snprintf(full_path, sizeof(full_path), "%s/PG_VERSION", path);
    1514             : 
    1515       11742 :     file = AllocateFile(full_path, "r");
    1516       11742 :     if (!file)
    1517             :     {
    1518           0 :         if (errno == ENOENT)
    1519           0 :             ereport(FATAL,
    1520             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1521             :                      errmsg("\"%s\" is not a valid data directory",
    1522             :                             path),
    1523             :                      errdetail("File \"%s\" is missing.", full_path)));
    1524             :         else
    1525           0 :             ereport(FATAL,
    1526             :                     (errcode_for_file_access(),
    1527             :                      errmsg("could not open file \"%s\": %m", full_path)));
    1528             :     }
    1529             : 
    1530       11742 :     file_version_string[0] = '\0';
    1531       11742 :     ret = fscanf(file, "%63s", file_version_string);
    1532       11742 :     file_major = strtol(file_version_string, &endptr, 10);
    1533             : 
    1534       11742 :     if (ret != 1 || endptr == file_version_string)
    1535           0 :         ereport(FATAL,
    1536             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1537             :                  errmsg("\"%s\" is not a valid data directory",
    1538             :                         path),
    1539             :                  errdetail("File \"%s\" does not contain valid data.",
    1540             :                            full_path),
    1541             :                  errhint("You might need to initdb.")));
    1542             : 
    1543       11742 :     FreeFile(file);
    1544             : 
    1545       11742 :     if (my_major != file_major)
    1546           0 :         ereport(FATAL,
    1547             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1548             :                  errmsg("database files are incompatible with server"),
    1549             :                  errdetail("The data directory was initialized by PostgreSQL version %s, "
    1550             :                            "which is not compatible with this version %s.",
    1551             :                            file_version_string, my_version_string)));
    1552       11742 : }
    1553             : 
    1554             : /*-------------------------------------------------------------------------
    1555             :  *              Library preload support
    1556             :  *-------------------------------------------------------------------------
    1557             :  */
    1558             : 
    1559             : /*
    1560             :  * GUC variables: lists of library names to be preloaded at postmaster
    1561             :  * start and at backend start
    1562             :  */
    1563             : char       *session_preload_libraries_string = NULL;
    1564             : char       *shared_preload_libraries_string = NULL;
    1565             : char       *local_preload_libraries_string = NULL;
    1566             : 
    1567             : /* Flag telling that we are loading shared_preload_libraries */
    1568             : bool        process_shared_preload_libraries_in_progress = false;
    1569             : 
    1570             : /*
    1571             :  * load the shared libraries listed in 'libraries'
    1572             :  *
    1573             :  * 'gucname': name of GUC variable, for error reports
    1574             :  * 'restricted': if true, force libraries to be in $libdir/plugins/
    1575             :  */
    1576             : static void
    1577       17064 : load_libraries(const char *libraries, const char *gucname, bool restricted)
    1578             : {
    1579             :     char       *rawstring;
    1580             :     List       *elemlist;
    1581             :     ListCell   *l;
    1582             : 
    1583       17064 :     if (libraries == NULL || libraries[0] == '\0')
    1584       17052 :         return;                 /* nothing to do */
    1585             : 
    1586             :     /* Need a modifiable copy of string */
    1587          12 :     rawstring = pstrdup(libraries);
    1588             : 
    1589             :     /* Parse string into list of filename paths */
    1590          12 :     if (!SplitDirectoriesString(rawstring, ',', &elemlist))
    1591             :     {
    1592             :         /* syntax error in list */
    1593           0 :         list_free_deep(elemlist);
    1594           0 :         pfree(rawstring);
    1595           0 :         ereport(LOG,
    1596             :                 (errcode(ERRCODE_SYNTAX_ERROR),
    1597             :                  errmsg("invalid list syntax in parameter \"%s\"",
    1598             :                         gucname)));
    1599           0 :         return;
    1600             :     }
    1601             : 
    1602          24 :     foreach(l, elemlist)
    1603             :     {
    1604             :         /* Note that filename was already canonicalized */
    1605          12 :         char       *filename = (char *) lfirst(l);
    1606          12 :         char       *expanded = NULL;
    1607             : 
    1608             :         /* If restricting, insert $libdir/plugins if not mentioned already */
    1609          12 :         if (restricted && first_dir_separator(filename) == NULL)
    1610             :         {
    1611           0 :             expanded = psprintf("$libdir/plugins/%s", filename);
    1612           0 :             filename = expanded;
    1613             :         }
    1614          12 :         load_file(filename, restricted);
    1615          12 :         ereport(DEBUG1,
    1616             :                 (errmsg("loaded library \"%s\"", filename)));
    1617          12 :         if (expanded)
    1618           0 :             pfree(expanded);
    1619             :     }
    1620             : 
    1621          12 :     list_free_deep(elemlist);
    1622          12 :     pfree(rawstring);
    1623             : }
    1624             : 
    1625             : /*
    1626             :  * process any libraries that should be preloaded at postmaster start
    1627             :  */
    1628             : void
    1629         724 : process_shared_preload_libraries(void)
    1630             : {
    1631         724 :     process_shared_preload_libraries_in_progress = true;
    1632         724 :     load_libraries(shared_preload_libraries_string,
    1633             :                    "shared_preload_libraries",
    1634             :                    false);
    1635         724 :     process_shared_preload_libraries_in_progress = false;
    1636         724 : }
    1637             : 
    1638             : /*
    1639             :  * process any libraries that should be preloaded at backend start
    1640             :  */
    1641             : void
    1642        8170 : process_session_preload_libraries(void)
    1643             : {
    1644        8170 :     load_libraries(session_preload_libraries_string,
    1645             :                    "session_preload_libraries",
    1646             :                    false);
    1647        8170 :     load_libraries(local_preload_libraries_string,
    1648             :                    "local_preload_libraries",
    1649             :                    true);
    1650        8170 : }
    1651             : 
    1652             : void
    1653        2276 : pg_bindtextdomain(const char *domain)
    1654             : {
    1655             : #ifdef ENABLE_NLS
    1656        2276 :     if (my_exec_path[0] != '\0')
    1657             :     {
    1658             :         char        locale_path[MAXPGPATH];
    1659             : 
    1660        2276 :         get_locale_path(my_exec_path, locale_path);
    1661        2276 :         bindtextdomain(domain, locale_path);
    1662        2276 :         pg_bind_textdomain_codeset(domain);
    1663             :     }
    1664             : #endif
    1665        2276 : }

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