Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * miscinit.c
4 : * miscellaneous initialization support stuff
5 : *
6 : * Portions Copyright (c) 1996-2024, 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 "libpq/pqsignal.h"
36 : #include "mb/pg_wchar.h"
37 : #include "miscadmin.h"
38 : #include "pgstat.h"
39 : #include "postmaster/autovacuum.h"
40 : #include "postmaster/interrupt.h"
41 : #include "postmaster/postmaster.h"
42 : #include "replication/slotsync.h"
43 : #include "storage/fd.h"
44 : #include "storage/ipc.h"
45 : #include "storage/latch.h"
46 : #include "storage/pg_shmem.h"
47 : #include "storage/pmsignal.h"
48 : #include "storage/proc.h"
49 : #include "storage/procarray.h"
50 : #include "utils/builtins.h"
51 : #include "utils/guc.h"
52 : #include "utils/inval.h"
53 : #include "utils/memutils.h"
54 : #include "utils/pidfile.h"
55 : #include "utils/syscache.h"
56 : #include "utils/varlena.h"
57 :
58 :
59 : #define DIRECTORY_LOCK_FILE "postmaster.pid"
60 :
61 : ProcessingMode Mode = InitProcessing;
62 :
63 : BackendType MyBackendType;
64 :
65 : /* List of lock files to be removed at proc exit */
66 : static List *lock_files = NIL;
67 :
68 : static Latch LocalLatchData;
69 :
70 : /* ----------------------------------------------------------------
71 : * ignoring system indexes support stuff
72 : *
73 : * NOTE: "ignoring system indexes" means we do not use the system indexes
74 : * for lookups (either in hardwired catalog accesses or in planner-generated
75 : * plans). We do, however, still update the indexes when a catalog
76 : * modification is made.
77 : * ----------------------------------------------------------------
78 : */
79 :
80 : bool IgnoreSystemIndexes = false;
81 :
82 :
83 : /* ----------------------------------------------------------------
84 : * common process startup code
85 : * ----------------------------------------------------------------
86 : */
87 :
88 : /*
89 : * Initialize the basic environment for a postmaster child
90 : *
91 : * Should be called as early as possible after the child's startup. However,
92 : * on EXEC_BACKEND builds it does need to be after read_backend_variables().
93 : */
94 : void
95 33480 : InitPostmasterChild(void)
96 : {
97 33480 : IsUnderPostmaster = true; /* we are a postmaster subprocess now */
98 :
99 : /*
100 : * Start our win32 signal implementation. This has to be done after we
101 : * read the backend variables, because we need to pick up the signal pipe
102 : * from the parent process.
103 : */
104 : #ifdef WIN32
105 : pgwin32_signal_initialize();
106 : #endif
107 :
108 : /*
109 : * Set reference point for stack-depth checking. This might seem
110 : * redundant in !EXEC_BACKEND builds, but it's better to keep the depth
111 : * logic the same with and without that build option.
112 : */
113 33480 : (void) set_stack_base();
114 :
115 33480 : InitProcessGlobals();
116 :
117 : /*
118 : * make sure stderr is in binary mode before anything can possibly be
119 : * written to it, in case it's actually the syslogger pipe, so the pipe
120 : * chunking protocol isn't disturbed. Non-logpipe data gets translated on
121 : * redirection (e.g. via pg_ctl -l) anyway.
122 : */
123 : #ifdef WIN32
124 : _setmode(fileno(stderr), _O_BINARY);
125 : #endif
126 :
127 : /* We don't want the postmaster's proc_exit() handlers */
128 33480 : on_exit_reset();
129 :
130 : /* In EXEC_BACKEND case we will not have inherited BlockSig etc values */
131 : #ifdef EXEC_BACKEND
132 : pqinitmask();
133 : #endif
134 :
135 : /* Initialize process-local latch support */
136 33480 : InitializeLatchSupport();
137 33480 : InitProcessLocalLatch();
138 33480 : InitializeLatchWaitSet();
139 :
140 : /*
141 : * If possible, make this process a group leader, so that the postmaster
142 : * can signal any child processes too. Not all processes will have
143 : * children, but for consistency we make all postmaster child processes do
144 : * this.
145 : */
146 : #ifdef HAVE_SETSID
147 33480 : if (setsid() < 0)
148 0 : elog(FATAL, "setsid() failed: %m");
149 : #endif
150 :
151 : /*
152 : * Every postmaster child process is expected to respond promptly to
153 : * SIGQUIT at all times. Therefore we centrally remove SIGQUIT from
154 : * BlockSig and install a suitable signal handler. (Client-facing
155 : * processes may choose to replace this default choice of handler with
156 : * quickdie().) All other blockable signals remain blocked for now.
157 : */
158 33480 : pqsignal(SIGQUIT, SignalHandlerForCrashExit);
159 :
160 33480 : sigdelset(&BlockSig, SIGQUIT);
161 33480 : sigprocmask(SIG_SETMASK, &BlockSig, NULL);
162 :
163 : /* Request a signal if the postmaster dies, if possible. */
164 33480 : PostmasterDeathSignalInit();
165 :
166 : /* Don't give the pipe to subprograms that we execute. */
167 : #ifndef WIN32
168 33480 : if (fcntl(postmaster_alive_fds[POSTMASTER_FD_WATCH], F_SETFD, FD_CLOEXEC) < 0)
169 0 : ereport(FATAL,
170 : (errcode_for_socket_access(),
171 : errmsg_internal("could not set postmaster death monitoring pipe to FD_CLOEXEC mode: %m")));
172 : #endif
173 33480 : }
174 :
175 : /*
176 : * Initialize the basic environment for a standalone process.
177 : *
178 : * argv0 has to be suitable to find the program's executable.
179 : */
180 : void
181 392 : InitStandaloneProcess(const char *argv0)
182 : {
183 : Assert(!IsPostmasterEnvironment);
184 :
185 392 : MyBackendType = B_STANDALONE_BACKEND;
186 :
187 : /*
188 : * Start our win32 signal implementation
189 : */
190 : #ifdef WIN32
191 : pgwin32_signal_initialize();
192 : #endif
193 :
194 392 : InitProcessGlobals();
195 :
196 : /* Initialize process-local latch support */
197 392 : InitializeLatchSupport();
198 392 : InitProcessLocalLatch();
199 392 : InitializeLatchWaitSet();
200 :
201 : /*
202 : * For consistency with InitPostmasterChild, initialize signal mask here.
203 : * But we don't unblock SIGQUIT or provide a default handler for it.
204 : */
205 392 : pqinitmask();
206 392 : sigprocmask(SIG_SETMASK, &BlockSig, NULL);
207 :
208 : /* Compute paths, no postmaster to inherit from */
209 392 : if (my_exec_path[0] == '\0')
210 : {
211 392 : if (find_my_exec(argv0, my_exec_path) < 0)
212 0 : elog(FATAL, "%s: could not locate my own executable path",
213 : argv0);
214 : }
215 :
216 392 : if (pkglib_path[0] == '\0')
217 392 : get_pkglib_path(my_exec_path, pkglib_path);
218 392 : }
219 :
220 : void
221 33364 : SwitchToSharedLatch(void)
222 : {
223 : Assert(MyLatch == &LocalLatchData);
224 : Assert(MyProc != NULL);
225 :
226 33364 : MyLatch = &MyProc->procLatch;
227 :
228 33364 : if (FeBeWaitSet)
229 24052 : ModifyWaitEvent(FeBeWaitSet, FeBeWaitSetLatchPos, WL_LATCH_SET,
230 : MyLatch);
231 :
232 : /*
233 : * Set the shared latch as the local one might have been set. This
234 : * shouldn't normally be necessary as code is supposed to check the
235 : * condition before waiting for the latch, but a bit care can't hurt.
236 : */
237 33364 : SetLatch(MyLatch);
238 33364 : }
239 :
240 : void
241 35346 : InitProcessLocalLatch(void)
242 : {
243 35346 : MyLatch = &LocalLatchData;
244 35346 : InitLatch(MyLatch);
245 35346 : }
246 :
247 : void
248 33364 : SwitchBackToLocalLatch(void)
249 : {
250 : Assert(MyLatch != &LocalLatchData);
251 : Assert(MyProc != NULL && MyLatch == &MyProc->procLatch);
252 :
253 33364 : MyLatch = &LocalLatchData;
254 :
255 33364 : if (FeBeWaitSet)
256 24052 : ModifyWaitEvent(FeBeWaitSet, FeBeWaitSetLatchPos, WL_LATCH_SET,
257 : MyLatch);
258 :
259 33364 : SetLatch(MyLatch);
260 33364 : }
261 :
262 : const char *
263 61716 : GetBackendTypeDesc(BackendType backendType)
264 : {
265 61716 : const char *backendDesc = "unknown process type";
266 :
267 61716 : switch (backendType)
268 : {
269 112 : case B_INVALID:
270 112 : backendDesc = "not initialized";
271 112 : break;
272 186 : case B_ARCHIVER:
273 186 : backendDesc = "archiver";
274 186 : break;
275 1948 : case B_AUTOVAC_LAUNCHER:
276 1948 : backendDesc = "autovacuum launcher";
277 1948 : break;
278 308 : case B_AUTOVAC_WORKER:
279 308 : backendDesc = "autovacuum worker";
280 308 : break;
281 45454 : case B_BACKEND:
282 45454 : backendDesc = "client backend";
283 45454 : break;
284 112 : case B_BG_WORKER:
285 112 : backendDesc = "background worker";
286 112 : break;
287 2266 : case B_BG_WRITER:
288 2266 : backendDesc = "background writer";
289 2266 : break;
290 2922 : case B_CHECKPOINTER:
291 2922 : backendDesc = "checkpointer";
292 2922 : break;
293 114 : case B_LOGGER:
294 114 : backendDesc = "logger";
295 114 : break;
296 120 : case B_SLOTSYNC_WORKER:
297 120 : backendDesc = "slotsync worker";
298 120 : break;
299 112 : case B_STANDALONE_BACKEND:
300 112 : backendDesc = "standalone backend";
301 112 : break;
302 1686 : case B_STARTUP:
303 1686 : backendDesc = "startup";
304 1686 : break;
305 544 : case B_WAL_RECEIVER:
306 544 : backendDesc = "walreceiver";
307 544 : break;
308 3576 : case B_WAL_SENDER:
309 3576 : backendDesc = "walsender";
310 3576 : break;
311 114 : case B_WAL_SUMMARIZER:
312 114 : backendDesc = "walsummarizer";
313 114 : break;
314 2142 : case B_WAL_WRITER:
315 2142 : backendDesc = "walwriter";
316 2142 : break;
317 : }
318 :
319 61716 : return backendDesc;
320 : }
321 :
322 : /* ----------------------------------------------------------------
323 : * database path / name support stuff
324 : * ----------------------------------------------------------------
325 : */
326 :
327 : void
328 26690 : SetDatabasePath(const char *path)
329 : {
330 : /* This should happen only once per process */
331 : Assert(!DatabasePath);
332 26690 : DatabasePath = MemoryContextStrdup(TopMemoryContext, path);
333 26690 : }
334 :
335 : /*
336 : * Validate the proposed data directory.
337 : *
338 : * Also initialize file and directory create modes and mode mask.
339 : */
340 : void
341 1812 : checkDataDir(void)
342 : {
343 : struct stat stat_buf;
344 :
345 : Assert(DataDir);
346 :
347 1812 : if (stat(DataDir, &stat_buf) != 0)
348 : {
349 0 : if (errno == ENOENT)
350 0 : ereport(FATAL,
351 : (errcode_for_file_access(),
352 : errmsg("data directory \"%s\" does not exist",
353 : DataDir)));
354 : else
355 0 : ereport(FATAL,
356 : (errcode_for_file_access(),
357 : errmsg("could not read permissions of directory \"%s\": %m",
358 : DataDir)));
359 : }
360 :
361 : /* eventual chdir would fail anyway, but let's test ... */
362 1812 : if (!S_ISDIR(stat_buf.st_mode))
363 0 : ereport(FATAL,
364 : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
365 : errmsg("specified data directory \"%s\" is not a directory",
366 : DataDir)));
367 :
368 : /*
369 : * Check that the directory belongs to my userid; if not, reject.
370 : *
371 : * This check is an essential part of the interlock that prevents two
372 : * postmasters from starting in the same directory (see CreateLockFile()).
373 : * Do not remove or weaken it.
374 : *
375 : * XXX can we safely enable this check on Windows?
376 : */
377 : #if !defined(WIN32) && !defined(__CYGWIN__)
378 1812 : if (stat_buf.st_uid != geteuid())
379 0 : ereport(FATAL,
380 : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
381 : errmsg("data directory \"%s\" has wrong ownership",
382 : DataDir),
383 : errhint("The server must be started by the user that owns the data directory.")));
384 : #endif
385 :
386 : /*
387 : * Check if the directory has correct permissions. If not, reject.
388 : *
389 : * Only two possible modes are allowed, 0700 and 0750. The latter mode
390 : * indicates that group read/execute should be allowed on all newly
391 : * created files and directories.
392 : *
393 : * XXX temporarily suppress check when on Windows, because there may not
394 : * be proper support for Unix-y file permissions. Need to think of a
395 : * reasonable check to apply on Windows.
396 : */
397 : #if !defined(WIN32) && !defined(__CYGWIN__)
398 1812 : if (stat_buf.st_mode & PG_MODE_MASK_GROUP)
399 0 : ereport(FATAL,
400 : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
401 : errmsg("data directory \"%s\" has invalid permissions",
402 : DataDir),
403 : errdetail("Permissions should be u=rwx (0700) or u=rwx,g=rx (0750).")));
404 : #endif
405 :
406 : /*
407 : * Reset creation modes and mask based on the mode of the data directory.
408 : *
409 : * The mask was set earlier in startup to disallow group permissions on
410 : * newly created files and directories. However, if group read/execute
411 : * are present on the data directory then modify the create modes and mask
412 : * to allow group read/execute on newly created files and directories and
413 : * set the data_directory_mode GUC.
414 : *
415 : * Suppress when on Windows, because there may not be proper support for
416 : * Unix-y file permissions.
417 : */
418 : #if !defined(WIN32) && !defined(__CYGWIN__)
419 1812 : SetDataDirectoryCreatePerm(stat_buf.st_mode);
420 :
421 1812 : umask(pg_mode_mask);
422 1812 : data_directory_mode = pg_dir_create_mode;
423 : #endif
424 :
425 : /* Check for PG_VERSION */
426 1812 : ValidatePgVersion(DataDir);
427 1812 : }
428 :
429 : /*
430 : * Set data directory, but make sure it's an absolute path. Use this,
431 : * never set DataDir directly.
432 : */
433 : void
434 1818 : SetDataDir(const char *dir)
435 : {
436 : char *new;
437 :
438 : Assert(dir);
439 :
440 : /* If presented path is relative, convert to absolute */
441 1818 : new = make_absolute_path(dir);
442 :
443 1818 : free(DataDir);
444 1818 : DataDir = new;
445 1818 : }
446 :
447 : /*
448 : * Change working directory to DataDir. Most of the postmaster and backend
449 : * code assumes that we are in DataDir so it can use relative paths to access
450 : * stuff in and under the data directory. For convenience during path
451 : * setup, however, we don't force the chdir to occur during SetDataDir.
452 : */
453 : void
454 1812 : ChangeToDataDir(void)
455 : {
456 : Assert(DataDir);
457 :
458 1812 : if (chdir(DataDir) < 0)
459 0 : ereport(FATAL,
460 : (errcode_for_file_access(),
461 : errmsg("could not change directory to \"%s\": %m",
462 : DataDir)));
463 1812 : }
464 :
465 :
466 : /* ----------------------------------------------------------------
467 : * User ID state
468 : *
469 : * We have to track several different values associated with the concept
470 : * of "user ID".
471 : *
472 : * AuthenticatedUserId is determined at connection start and never changes.
473 : *
474 : * SessionUserId is initially the same as AuthenticatedUserId, but can be
475 : * changed by SET SESSION AUTHORIZATION (if AuthenticatedUserId is a
476 : * superuser). This is the ID reported by the SESSION_USER SQL function.
477 : *
478 : * OuterUserId is the current user ID in effect at the "outer level" (outside
479 : * any transaction or function). This is initially the same as SessionUserId,
480 : * but can be changed by SET ROLE to any role that SessionUserId is a
481 : * member of. (XXX rename to something like CurrentRoleId?)
482 : *
483 : * CurrentUserId is the current effective user ID; this is the one to use
484 : * for all normal permissions-checking purposes. At outer level this will
485 : * be the same as OuterUserId, but it changes during calls to SECURITY
486 : * DEFINER functions, as well as locally in some specialized commands.
487 : *
488 : * SecurityRestrictionContext holds flags indicating reason(s) for changing
489 : * CurrentUserId. In some cases we need to lock down operations that are
490 : * not directly controlled by privilege settings, and this provides a
491 : * convenient way to do it.
492 : * ----------------------------------------------------------------
493 : */
494 : static Oid AuthenticatedUserId = InvalidOid;
495 : static Oid SessionUserId = InvalidOid;
496 : static Oid OuterUserId = InvalidOid;
497 : static Oid CurrentUserId = InvalidOid;
498 : static const char *SystemUser = NULL;
499 :
500 : /* We also have to remember the superuser state of the session user */
501 : static bool SessionUserIsSuperuser = false;
502 :
503 : static int SecurityRestrictionContext = 0;
504 :
505 : /* We also remember if a SET ROLE is currently active */
506 : static bool SetRoleIsActive = false;
507 :
508 : /*
509 : * GetUserId - get the current effective user ID.
510 : *
511 : * Note: there's no SetUserId() anymore; use SetUserIdAndSecContext().
512 : */
513 : Oid
514 11242304 : GetUserId(void)
515 : {
516 : Assert(OidIsValid(CurrentUserId));
517 11242304 : return CurrentUserId;
518 : }
519 :
520 :
521 : /*
522 : * GetOuterUserId/SetOuterUserId - get/set the outer-level user ID.
523 : */
524 : Oid
525 1486 : GetOuterUserId(void)
526 : {
527 : Assert(OidIsValid(OuterUserId));
528 1486 : return OuterUserId;
529 : }
530 :
531 :
532 : static void
533 4174 : SetOuterUserId(Oid userid)
534 : {
535 : Assert(SecurityRestrictionContext == 0);
536 : Assert(OidIsValid(userid));
537 4174 : OuterUserId = userid;
538 :
539 : /* We force the effective user ID to match, too */
540 4174 : CurrentUserId = userid;
541 4174 : }
542 :
543 :
544 : /*
545 : * GetSessionUserId/SetSessionUserId - get/set the session user ID.
546 : */
547 : Oid
548 57590 : GetSessionUserId(void)
549 : {
550 : Assert(OidIsValid(SessionUserId));
551 57590 : return SessionUserId;
552 : }
553 :
554 :
555 : static void
556 61688 : SetSessionUserId(Oid userid, bool is_superuser)
557 : {
558 : Assert(SecurityRestrictionContext == 0);
559 : Assert(OidIsValid(userid));
560 61688 : SessionUserId = userid;
561 61688 : SessionUserIsSuperuser = is_superuser;
562 61688 : SetRoleIsActive = false;
563 :
564 : /* We force the effective user IDs to match, too */
565 61688 : OuterUserId = userid;
566 61688 : CurrentUserId = userid;
567 61688 : }
568 :
569 : /*
570 : * Return the system user representing the authenticated identity.
571 : * It is defined in InitializeSystemUser() as auth_method:authn_id.
572 : */
573 : const char *
574 44 : GetSystemUser(void)
575 : {
576 44 : return SystemUser;
577 : }
578 :
579 : /*
580 : * GetAuthenticatedUserId - get the authenticated user ID
581 : */
582 : Oid
583 35886 : GetAuthenticatedUserId(void)
584 : {
585 : Assert(OidIsValid(AuthenticatedUserId));
586 35886 : return AuthenticatedUserId;
587 : }
588 :
589 :
590 : /*
591 : * GetUserIdAndSecContext/SetUserIdAndSecContext - get/set the current user ID
592 : * and the SecurityRestrictionContext flags.
593 : *
594 : * Currently there are three valid bits in SecurityRestrictionContext:
595 : *
596 : * SECURITY_LOCAL_USERID_CHANGE indicates that we are inside an operation
597 : * that is temporarily changing CurrentUserId via these functions. This is
598 : * needed to indicate that the actual value of CurrentUserId is not in sync
599 : * with guc.c's internal state, so SET ROLE has to be disallowed.
600 : *
601 : * SECURITY_RESTRICTED_OPERATION indicates that we are inside an operation
602 : * that does not wish to trust called user-defined functions at all. The
603 : * policy is to use this before operations, e.g. autovacuum and REINDEX, that
604 : * enumerate relations of a database or schema and run functions associated
605 : * with each found relation. The relation owner is the new user ID. Set this
606 : * as soon as possible after locking the relation. Restore the old user ID as
607 : * late as possible before closing the relation; restoring it shortly after
608 : * close is also tolerable. If a command has both relation-enumerating and
609 : * non-enumerating modes, e.g. ANALYZE, both modes set this bit. This bit
610 : * prevents not only SET ROLE, but various other changes of session state that
611 : * normally is unprotected but might possibly be used to subvert the calling
612 : * session later. An example is replacing an existing prepared statement with
613 : * new code, which will then be executed with the outer session's permissions
614 : * when the prepared statement is next used. These restrictions are fairly
615 : * draconian, but the functions called in relation-enumerating operations are
616 : * really supposed to be side-effect-free anyway.
617 : *
618 : * SECURITY_NOFORCE_RLS indicates that we are inside an operation which should
619 : * ignore the FORCE ROW LEVEL SECURITY per-table indication. This is used to
620 : * ensure that FORCE RLS does not mistakenly break referential integrity
621 : * checks. Note that this is intentionally only checked when running as the
622 : * owner of the table (which should always be the case for referential
623 : * integrity checks).
624 : *
625 : * Unlike GetUserId, GetUserIdAndSecContext does *not* Assert that the current
626 : * value of CurrentUserId is valid; nor does SetUserIdAndSecContext require
627 : * the new value to be valid. In fact, these routines had better not
628 : * ever throw any kind of error. This is because they are used by
629 : * StartTransaction and AbortTransaction to save/restore the settings,
630 : * and during the first transaction within a backend, the value to be saved
631 : * and perhaps restored is indeed invalid. We have to be able to get
632 : * through AbortTransaction without asserting in case InitPostgres fails.
633 : */
634 : void
635 1042030 : GetUserIdAndSecContext(Oid *userid, int *sec_context)
636 : {
637 1042030 : *userid = CurrentUserId;
638 1042030 : *sec_context = SecurityRestrictionContext;
639 1042030 : }
640 :
641 : void
642 992092 : SetUserIdAndSecContext(Oid userid, int sec_context)
643 : {
644 992092 : CurrentUserId = userid;
645 992092 : SecurityRestrictionContext = sec_context;
646 992092 : }
647 :
648 :
649 : /*
650 : * InLocalUserIdChange - are we inside a local change of CurrentUserId?
651 : */
652 : bool
653 34734 : InLocalUserIdChange(void)
654 : {
655 34734 : return (SecurityRestrictionContext & SECURITY_LOCAL_USERID_CHANGE) != 0;
656 : }
657 :
658 : /*
659 : * InSecurityRestrictedOperation - are we inside a security-restricted command?
660 : */
661 : bool
662 46292 : InSecurityRestrictedOperation(void)
663 : {
664 46292 : return (SecurityRestrictionContext & SECURITY_RESTRICTED_OPERATION) != 0;
665 : }
666 :
667 : /*
668 : * InNoForceRLSOperation - are we ignoring FORCE ROW LEVEL SECURITY ?
669 : */
670 : bool
671 216 : InNoForceRLSOperation(void)
672 : {
673 216 : return (SecurityRestrictionContext & SECURITY_NOFORCE_RLS) != 0;
674 : }
675 :
676 :
677 : /*
678 : * These are obsolete versions of Get/SetUserIdAndSecContext that are
679 : * only provided for bug-compatibility with some rather dubious code in
680 : * pljava. We allow the userid to be set, but only when not inside a
681 : * security restriction context.
682 : */
683 : void
684 0 : GetUserIdAndContext(Oid *userid, bool *sec_def_context)
685 : {
686 0 : *userid = CurrentUserId;
687 0 : *sec_def_context = InLocalUserIdChange();
688 0 : }
689 :
690 : void
691 0 : SetUserIdAndContext(Oid userid, bool sec_def_context)
692 : {
693 : /* We throw the same error SET ROLE would. */
694 0 : if (InSecurityRestrictedOperation())
695 0 : ereport(ERROR,
696 : (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
697 : errmsg("cannot set parameter \"%s\" within security-restricted operation",
698 : "role")));
699 0 : CurrentUserId = userid;
700 0 : if (sec_def_context)
701 0 : SecurityRestrictionContext |= SECURITY_LOCAL_USERID_CHANGE;
702 : else
703 0 : SecurityRestrictionContext &= ~SECURITY_LOCAL_USERID_CHANGE;
704 0 : }
705 :
706 :
707 : /*
708 : * Check whether specified role has explicit REPLICATION privilege
709 : */
710 : bool
711 3054 : has_rolreplication(Oid roleid)
712 : {
713 3054 : bool result = false;
714 : HeapTuple utup;
715 :
716 : /* Superusers bypass all permission checking. */
717 3054 : if (superuser_arg(roleid))
718 2944 : return true;
719 :
720 110 : utup = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid));
721 110 : if (HeapTupleIsValid(utup))
722 : {
723 110 : result = ((Form_pg_authid) GETSTRUCT(utup))->rolreplication;
724 110 : ReleaseSysCache(utup);
725 : }
726 110 : return result;
727 : }
728 :
729 : /*
730 : * Initialize user identity during normal backend startup
731 : */
732 : void
733 27354 : InitializeSessionUserId(const char *rolename, Oid roleid, bool bypass_login_check)
734 : {
735 : HeapTuple roleTup;
736 : Form_pg_authid rform;
737 : char *rname;
738 : bool is_superuser;
739 :
740 : /*
741 : * Don't do scans if we're bootstrapping, none of the system catalogs
742 : * exist yet, and they should be owned by postgres anyway.
743 : */
744 : Assert(!IsBootstrapProcessingMode());
745 :
746 : /* call only once */
747 : Assert(!OidIsValid(AuthenticatedUserId));
748 :
749 : /*
750 : * Make sure syscache entries are flushed for recent catalog changes. This
751 : * allows us to find roles that were created on-the-fly during
752 : * authentication.
753 : */
754 27354 : AcceptInvalidationMessages();
755 :
756 27354 : if (rolename != NULL)
757 : {
758 23932 : roleTup = SearchSysCache1(AUTHNAME, PointerGetDatum(rolename));
759 23932 : if (!HeapTupleIsValid(roleTup))
760 4 : ereport(FATAL,
761 : (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
762 : errmsg("role \"%s\" does not exist", rolename)));
763 : }
764 : else
765 : {
766 3422 : roleTup = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid));
767 3422 : if (!HeapTupleIsValid(roleTup))
768 0 : ereport(FATAL,
769 : (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
770 : errmsg("role with OID %u does not exist", roleid)));
771 : }
772 :
773 27350 : rform = (Form_pg_authid) GETSTRUCT(roleTup);
774 27350 : roleid = rform->oid;
775 27350 : rname = NameStr(rform->rolname);
776 :
777 27350 : AuthenticatedUserId = roleid;
778 27350 : is_superuser = rform->rolsuper;
779 :
780 : /* This sets OuterUserId/CurrentUserId too */
781 27350 : SetSessionUserId(roleid, is_superuser);
782 :
783 : /* Also mark our PGPROC entry with the authenticated user id */
784 : /* (We assume this is an atomic store so no lock is needed) */
785 27350 : MyProc->roleId = roleid;
786 :
787 : /*
788 : * These next checks are not enforced when in standalone mode, so that
789 : * there is a way to recover from sillinesses like "UPDATE pg_authid SET
790 : * rolcanlogin = false;".
791 : */
792 27350 : if (IsUnderPostmaster)
793 : {
794 : /*
795 : * Is role allowed to login at all?
796 : */
797 27350 : if (!bypass_login_check && !rform->rolcanlogin)
798 6 : ereport(FATAL,
799 : (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
800 : errmsg("role \"%s\" is not permitted to log in",
801 : rname)));
802 :
803 : /*
804 : * Check connection limit for this role.
805 : *
806 : * There is a race condition here --- we create our PGPROC before
807 : * checking for other PGPROCs. If two backends did this at about the
808 : * same time, they might both think they were over the limit, while
809 : * ideally one should succeed and one fail. Getting that to work
810 : * exactly seems more trouble than it is worth, however; instead we
811 : * just document that the connection limit is approximate.
812 : */
813 27344 : if (rform->rolconnlimit >= 0 &&
814 0 : !is_superuser &&
815 0 : CountUserBackends(roleid) > rform->rolconnlimit)
816 0 : ereport(FATAL,
817 : (errcode(ERRCODE_TOO_MANY_CONNECTIONS),
818 : errmsg("too many connections for role \"%s\"",
819 : rname)));
820 : }
821 :
822 : /* Record username and superuser status as GUC settings too */
823 27344 : SetConfigOption("session_authorization", rname,
824 : PGC_BACKEND, PGC_S_OVERRIDE);
825 27344 : SetConfigOption("is_superuser",
826 : is_superuser ? "on" : "off",
827 : PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
828 :
829 27344 : ReleaseSysCache(roleTup);
830 27344 : }
831 :
832 :
833 : /*
834 : * Initialize user identity during special backend startup
835 : */
836 : void
837 930 : InitializeSessionUserIdStandalone(void)
838 : {
839 : /*
840 : * This function should only be called in single-user mode, in autovacuum
841 : * workers, in slot sync worker and in background workers.
842 : */
843 : Assert(!IsUnderPostmaster || AmAutoVacuumWorkerProcess() ||
844 : AmLogicalSlotSyncWorkerProcess() || AmBackgroundWorkerProcess());
845 :
846 : /* call only once */
847 : Assert(!OidIsValid(AuthenticatedUserId));
848 :
849 930 : AuthenticatedUserId = BOOTSTRAP_SUPERUSERID;
850 930 : SetSessionUserId(BOOTSTRAP_SUPERUSERID, true);
851 :
852 : /*
853 : * XXX This should set SetConfigOption("session_authorization"), too.
854 : * Since we don't, C code will get NULL, and current_setting() will get an
855 : * empty string.
856 : */
857 930 : SetConfigOption("is_superuser", "on",
858 : PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
859 930 : }
860 :
861 : /*
862 : * Initialize the system user.
863 : *
864 : * This is built as auth_method:authn_id.
865 : */
866 : void
867 212 : InitializeSystemUser(const char *authn_id, const char *auth_method)
868 : {
869 : char *system_user;
870 :
871 : /* call only once */
872 : Assert(SystemUser == NULL);
873 :
874 : /*
875 : * InitializeSystemUser should be called only when authn_id is not NULL,
876 : * meaning that auth_method is valid.
877 : */
878 : Assert(authn_id != NULL);
879 :
880 212 : system_user = psprintf("%s:%s", auth_method, authn_id);
881 :
882 : /* Store SystemUser in long-lived storage */
883 212 : SystemUser = MemoryContextStrdup(TopMemoryContext, system_user);
884 212 : pfree(system_user);
885 212 : }
886 :
887 : /*
888 : * SQL-function SYSTEM_USER
889 : */
890 : Datum
891 44 : system_user(PG_FUNCTION_ARGS)
892 : {
893 44 : const char *sysuser = GetSystemUser();
894 :
895 44 : if (sysuser)
896 22 : PG_RETURN_DATUM(CStringGetTextDatum(sysuser));
897 : else
898 22 : PG_RETURN_NULL();
899 : }
900 :
901 : /*
902 : * Change session auth ID while running
903 : *
904 : * Note that we set the GUC variable is_superuser to indicate whether the
905 : * current role is a superuser.
906 : */
907 : void
908 33408 : SetSessionAuthorization(Oid userid, bool is_superuser)
909 : {
910 33408 : SetSessionUserId(userid, is_superuser);
911 :
912 33408 : SetConfigOption("is_superuser",
913 : is_superuser ? "on" : "off",
914 : PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
915 33408 : }
916 :
917 : /*
918 : * Report current role id
919 : * This follows the semantics of SET ROLE, ie return the outer-level ID
920 : * not the current effective ID, and return InvalidOid when the setting
921 : * is logically SET ROLE NONE.
922 : */
923 : Oid
924 860 : GetCurrentRoleId(void)
925 : {
926 860 : if (SetRoleIsActive)
927 12 : return OuterUserId;
928 : else
929 848 : return InvalidOid;
930 : }
931 :
932 : /*
933 : * Change Role ID while running (SET ROLE)
934 : *
935 : * If roleid is InvalidOid, we are doing SET ROLE NONE: revert to the
936 : * session user authorization. In this case the is_superuser argument
937 : * is ignored.
938 : *
939 : * When roleid is not InvalidOid, the caller must have checked whether
940 : * the session user has permission to become that role. (We cannot check
941 : * here because this routine must be able to execute in a failed transaction
942 : * to restore a prior value of the ROLE GUC variable.)
943 : */
944 : void
945 6040 : SetCurrentRoleId(Oid roleid, bool is_superuser)
946 : {
947 : /*
948 : * Get correct info if it's SET ROLE NONE
949 : *
950 : * If SessionUserId hasn't been set yet, just do nothing --- the eventual
951 : * SetSessionUserId call will fix everything. This is needed since we
952 : * will get called during GUC initialization.
953 : */
954 6040 : if (!OidIsValid(roleid))
955 : {
956 5170 : if (!OidIsValid(SessionUserId))
957 1866 : return;
958 :
959 3304 : roleid = SessionUserId;
960 3304 : is_superuser = SessionUserIsSuperuser;
961 :
962 3304 : SetRoleIsActive = false;
963 : }
964 : else
965 870 : SetRoleIsActive = true;
966 :
967 4174 : SetOuterUserId(roleid);
968 :
969 4174 : SetConfigOption("is_superuser",
970 : is_superuser ? "on" : "off",
971 : PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
972 : }
973 :
974 :
975 : /*
976 : * Get user name from user oid, returns NULL for nonexistent roleid if noerr
977 : * is true.
978 : */
979 : char *
980 20988 : GetUserNameFromId(Oid roleid, bool noerr)
981 : {
982 : HeapTuple tuple;
983 : char *result;
984 :
985 20988 : tuple = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid));
986 20988 : if (!HeapTupleIsValid(tuple))
987 : {
988 18 : if (!noerr)
989 0 : ereport(ERROR,
990 : (errcode(ERRCODE_UNDEFINED_OBJECT),
991 : errmsg("invalid role OID: %u", roleid)));
992 18 : result = NULL;
993 : }
994 : else
995 : {
996 20970 : result = pstrdup(NameStr(((Form_pg_authid) GETSTRUCT(tuple))->rolname));
997 20970 : ReleaseSysCache(tuple);
998 : }
999 20988 : return result;
1000 : }
1001 :
1002 : /* ------------------------------------------------------------------------
1003 : * Client connection state shared with parallel workers
1004 : *
1005 : * ClientConnectionInfo contains pieces of information about the client that
1006 : * need to be synced to parallel workers when they initialize.
1007 : *-------------------------------------------------------------------------
1008 : */
1009 :
1010 : ClientConnectionInfo MyClientConnectionInfo;
1011 :
1012 : /*
1013 : * Intermediate representation of ClientConnectionInfo for easier
1014 : * serialization. Variable-length fields are allocated right after this
1015 : * header.
1016 : */
1017 : typedef struct SerializedClientConnectionInfo
1018 : {
1019 : int32 authn_id_len; /* strlen(authn_id), or -1 if NULL */
1020 : UserAuth auth_method;
1021 : } SerializedClientConnectionInfo;
1022 :
1023 : /*
1024 : * Calculate the space needed to serialize MyClientConnectionInfo.
1025 : */
1026 : Size
1027 848 : EstimateClientConnectionInfoSpace(void)
1028 : {
1029 848 : Size size = 0;
1030 :
1031 848 : size = add_size(size, sizeof(SerializedClientConnectionInfo));
1032 :
1033 848 : if (MyClientConnectionInfo.authn_id)
1034 2 : size = add_size(size, strlen(MyClientConnectionInfo.authn_id) + 1);
1035 :
1036 848 : return size;
1037 : }
1038 :
1039 : /*
1040 : * Serialize MyClientConnectionInfo for use by parallel workers.
1041 : */
1042 : void
1043 848 : SerializeClientConnectionInfo(Size maxsize, char *start_address)
1044 : {
1045 848 : SerializedClientConnectionInfo serialized = {0};
1046 :
1047 848 : serialized.authn_id_len = -1;
1048 848 : serialized.auth_method = MyClientConnectionInfo.auth_method;
1049 :
1050 848 : if (MyClientConnectionInfo.authn_id)
1051 2 : serialized.authn_id_len = strlen(MyClientConnectionInfo.authn_id);
1052 :
1053 : /* Copy serialized representation to buffer */
1054 : Assert(maxsize >= sizeof(serialized));
1055 848 : memcpy(start_address, &serialized, sizeof(serialized));
1056 :
1057 848 : maxsize -= sizeof(serialized);
1058 848 : start_address += sizeof(serialized);
1059 :
1060 : /* Copy authn_id into the space after the struct */
1061 848 : if (serialized.authn_id_len >= 0)
1062 : {
1063 : Assert(maxsize >= (serialized.authn_id_len + 1));
1064 2 : memcpy(start_address,
1065 2 : MyClientConnectionInfo.authn_id,
1066 : /* include the NULL terminator to ease deserialization */
1067 2 : serialized.authn_id_len + 1);
1068 : }
1069 848 : }
1070 :
1071 : /*
1072 : * Restore MyClientConnectionInfo from its serialized representation.
1073 : */
1074 : void
1075 2664 : RestoreClientConnectionInfo(char *conninfo)
1076 : {
1077 : SerializedClientConnectionInfo serialized;
1078 :
1079 2664 : memcpy(&serialized, conninfo, sizeof(serialized));
1080 :
1081 : /* Copy the fields back into place */
1082 2664 : MyClientConnectionInfo.authn_id = NULL;
1083 2664 : MyClientConnectionInfo.auth_method = serialized.auth_method;
1084 :
1085 2664 : if (serialized.authn_id_len >= 0)
1086 : {
1087 : char *authn_id;
1088 :
1089 4 : authn_id = conninfo + sizeof(serialized);
1090 4 : MyClientConnectionInfo.authn_id = MemoryContextStrdup(TopMemoryContext,
1091 : authn_id);
1092 : }
1093 2664 : }
1094 :
1095 :
1096 : /*-------------------------------------------------------------------------
1097 : * Interlock-file support
1098 : *
1099 : * These routines are used to create both a data-directory lockfile
1100 : * ($DATADIR/postmaster.pid) and Unix-socket-file lockfiles ($SOCKFILE.lock).
1101 : * Both kinds of files contain the same info initially, although we can add
1102 : * more information to a data-directory lockfile after it's created, using
1103 : * AddToDataDirLockFile(). See pidfile.h for documentation of the contents
1104 : * of these lockfiles.
1105 : *
1106 : * On successful lockfile creation, a proc_exit callback to remove the
1107 : * lockfile is automatically created.
1108 : *-------------------------------------------------------------------------
1109 : */
1110 :
1111 : /*
1112 : * proc_exit callback to remove lockfiles.
1113 : */
1114 : static void
1115 1802 : UnlinkLockFiles(int status, Datum arg)
1116 : {
1117 : ListCell *l;
1118 :
1119 5054 : foreach(l, lock_files)
1120 : {
1121 3252 : char *curfile = (char *) lfirst(l);
1122 :
1123 3252 : unlink(curfile);
1124 : /* Should we complain if the unlink fails? */
1125 : }
1126 : /* Since we're about to exit, no need to reclaim storage */
1127 1802 : lock_files = NIL;
1128 :
1129 : /*
1130 : * Lock file removal should always be the last externally visible action
1131 : * of a postmaster or standalone backend, while we won't come here at all
1132 : * when exiting postmaster child processes. Therefore, this is a good
1133 : * place to log completion of shutdown. We could alternatively teach
1134 : * proc_exit() to do it, but that seems uglier. In a standalone backend,
1135 : * use NOTICE elevel to be less chatty.
1136 : */
1137 1802 : ereport(IsPostmasterEnvironment ? LOG : NOTICE,
1138 : (errmsg("database system is shut down")));
1139 1802 : }
1140 :
1141 : /*
1142 : * Create a lockfile.
1143 : *
1144 : * filename is the path name of the lockfile to create.
1145 : * amPostmaster is used to determine how to encode the output PID.
1146 : * socketDir is the Unix socket directory path to include (possibly empty).
1147 : * isDDLock and refName are used to determine what error message to produce.
1148 : */
1149 : static void
1150 3268 : CreateLockFile(const char *filename, bool amPostmaster,
1151 : const char *socketDir,
1152 : bool isDDLock, const char *refName)
1153 : {
1154 : int fd;
1155 : char buffer[MAXPGPATH * 2 + 256];
1156 : int ntries;
1157 : int len;
1158 : int encoded_pid;
1159 : pid_t other_pid;
1160 : pid_t my_pid,
1161 : my_p_pid,
1162 : my_gp_pid;
1163 : const char *envvar;
1164 :
1165 : /*
1166 : * If the PID in the lockfile is our own PID or our parent's or
1167 : * grandparent's PID, then the file must be stale (probably left over from
1168 : * a previous system boot cycle). We need to check this because of the
1169 : * likelihood that a reboot will assign exactly the same PID as we had in
1170 : * the previous reboot, or one that's only one or two counts larger and
1171 : * hence the lockfile's PID now refers to an ancestor shell process. We
1172 : * allow pg_ctl to pass down its parent shell PID (our grandparent PID)
1173 : * via the environment variable PG_GRANDPARENT_PID; this is so that
1174 : * launching the postmaster via pg_ctl can be just as reliable as
1175 : * launching it directly. There is no provision for detecting
1176 : * further-removed ancestor processes, but if the init script is written
1177 : * carefully then all but the immediate parent shell will be root-owned
1178 : * processes and so the kill test will fail with EPERM. Note that we
1179 : * cannot get a false negative this way, because an existing postmaster
1180 : * would surely never launch a competing postmaster or pg_ctl process
1181 : * directly.
1182 : */
1183 3268 : my_pid = getpid();
1184 :
1185 : #ifndef WIN32
1186 3268 : my_p_pid = getppid();
1187 : #else
1188 :
1189 : /*
1190 : * Windows hasn't got getppid(), but doesn't need it since it's not using
1191 : * real kill() either...
1192 : */
1193 : my_p_pid = 0;
1194 : #endif
1195 :
1196 3268 : envvar = getenv("PG_GRANDPARENT_PID");
1197 3268 : if (envvar)
1198 2596 : my_gp_pid = atoi(envvar);
1199 : else
1200 672 : my_gp_pid = 0;
1201 :
1202 : /*
1203 : * We need a loop here because of race conditions. But don't loop forever
1204 : * (for example, a non-writable $PGDATA directory might cause a failure
1205 : * that won't go away). 100 tries seems like plenty.
1206 : */
1207 3268 : for (ntries = 0;; ntries++)
1208 : {
1209 : /*
1210 : * Try to create the lock file --- O_EXCL makes this atomic.
1211 : *
1212 : * Think not to make the file protection weaker than 0600/0640. See
1213 : * comments below.
1214 : */
1215 3278 : fd = open(filename, O_RDWR | O_CREAT | O_EXCL, pg_file_create_mode);
1216 3278 : if (fd >= 0)
1217 3264 : break; /* Success; exit the retry loop */
1218 :
1219 : /*
1220 : * Couldn't create the pid file. Probably it already exists.
1221 : */
1222 14 : if ((errno != EEXIST && errno != EACCES) || ntries > 100)
1223 0 : ereport(FATAL,
1224 : (errcode_for_file_access(),
1225 : errmsg("could not create lock file \"%s\": %m",
1226 : filename)));
1227 :
1228 : /*
1229 : * Read the file to get the old owner's PID. Note race condition
1230 : * here: file might have been deleted since we tried to create it.
1231 : */
1232 14 : fd = open(filename, O_RDONLY, pg_file_create_mode);
1233 14 : if (fd < 0)
1234 : {
1235 0 : if (errno == ENOENT)
1236 0 : continue; /* race condition; try again */
1237 0 : ereport(FATAL,
1238 : (errcode_for_file_access(),
1239 : errmsg("could not open lock file \"%s\": %m",
1240 : filename)));
1241 : }
1242 14 : pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_CREATE_READ);
1243 14 : if ((len = read(fd, buffer, sizeof(buffer) - 1)) < 0)
1244 0 : ereport(FATAL,
1245 : (errcode_for_file_access(),
1246 : errmsg("could not read lock file \"%s\": %m",
1247 : filename)));
1248 14 : pgstat_report_wait_end();
1249 14 : close(fd);
1250 :
1251 14 : if (len == 0)
1252 : {
1253 0 : ereport(FATAL,
1254 : (errcode(ERRCODE_LOCK_FILE_EXISTS),
1255 : errmsg("lock file \"%s\" is empty", filename),
1256 : errhint("Either another server is starting, or the lock file is the remnant of a previous server startup crash.")));
1257 : }
1258 :
1259 14 : buffer[len] = '\0';
1260 14 : encoded_pid = atoi(buffer);
1261 :
1262 : /* if pid < 0, the pid is for postgres, not postmaster */
1263 14 : other_pid = (pid_t) (encoded_pid < 0 ? -encoded_pid : encoded_pid);
1264 :
1265 14 : if (other_pid <= 0)
1266 0 : elog(FATAL, "bogus data in lock file \"%s\": \"%s\"",
1267 : filename, buffer);
1268 :
1269 : /*
1270 : * Check to see if the other process still exists
1271 : *
1272 : * Per discussion above, my_pid, my_p_pid, and my_gp_pid can be
1273 : * ignored as false matches.
1274 : *
1275 : * Normally kill() will fail with ESRCH if the given PID doesn't
1276 : * exist.
1277 : *
1278 : * We can treat the EPERM-error case as okay because that error
1279 : * implies that the existing process has a different userid than we
1280 : * do, which means it cannot be a competing postmaster. A postmaster
1281 : * cannot successfully attach to a data directory owned by a userid
1282 : * other than its own, as enforced in checkDataDir(). Also, since we
1283 : * create the lockfiles mode 0600/0640, we'd have failed above if the
1284 : * lockfile belonged to another userid --- which means that whatever
1285 : * process kill() is reporting about isn't the one that made the
1286 : * lockfile. (NOTE: this last consideration is the only one that
1287 : * keeps us from blowing away a Unix socket file belonging to an
1288 : * instance of Postgres being run by someone else, at least on
1289 : * machines where /tmp hasn't got a stickybit.)
1290 : */
1291 14 : if (other_pid != my_pid && other_pid != my_p_pid &&
1292 : other_pid != my_gp_pid)
1293 : {
1294 14 : if (kill(other_pid, 0) == 0 ||
1295 10 : (errno != ESRCH && errno != EPERM))
1296 : {
1297 : /* lockfile belongs to a live process */
1298 4 : ereport(FATAL,
1299 : (errcode(ERRCODE_LOCK_FILE_EXISTS),
1300 : errmsg("lock file \"%s\" already exists",
1301 : filename),
1302 : isDDLock ?
1303 : (encoded_pid < 0 ?
1304 : errhint("Is another postgres (PID %d) running in data directory \"%s\"?",
1305 : (int) other_pid, refName) :
1306 : errhint("Is another postmaster (PID %d) running in data directory \"%s\"?",
1307 : (int) other_pid, refName)) :
1308 : (encoded_pid < 0 ?
1309 : errhint("Is another postgres (PID %d) using socket file \"%s\"?",
1310 : (int) other_pid, refName) :
1311 : errhint("Is another postmaster (PID %d) using socket file \"%s\"?",
1312 : (int) other_pid, refName))));
1313 : }
1314 : }
1315 :
1316 : /*
1317 : * No, the creating process did not exist. However, it could be that
1318 : * the postmaster crashed (or more likely was kill -9'd by a clueless
1319 : * admin) but has left orphan backends behind. Check for this by
1320 : * looking to see if there is an associated shmem segment that is
1321 : * still in use.
1322 : *
1323 : * Note: because postmaster.pid is written in multiple steps, we might
1324 : * not find the shmem ID values in it; we can't treat that as an
1325 : * error.
1326 : */
1327 10 : if (isDDLock)
1328 : {
1329 4 : char *ptr = buffer;
1330 : unsigned long id1,
1331 : id2;
1332 : int lineno;
1333 :
1334 28 : for (lineno = 1; lineno < LOCK_FILE_LINE_SHMEM_KEY; lineno++)
1335 : {
1336 24 : if ((ptr = strchr(ptr, '\n')) == NULL)
1337 0 : break;
1338 24 : ptr++;
1339 : }
1340 :
1341 4 : if (ptr != NULL &&
1342 4 : sscanf(ptr, "%lu %lu", &id1, &id2) == 2)
1343 : {
1344 4 : if (PGSharedMemoryIsInUse(id1, id2))
1345 0 : ereport(FATAL,
1346 : (errcode(ERRCODE_LOCK_FILE_EXISTS),
1347 : errmsg("pre-existing shared memory block (key %lu, ID %lu) is still in use",
1348 : id1, id2),
1349 : errhint("Terminate any old server processes associated with data directory \"%s\".",
1350 : refName)));
1351 : }
1352 : }
1353 :
1354 : /*
1355 : * Looks like nobody's home. Unlink the file and try again to create
1356 : * it. Need a loop because of possible race condition against other
1357 : * would-be creators.
1358 : */
1359 10 : if (unlink(filename) < 0)
1360 0 : ereport(FATAL,
1361 : (errcode_for_file_access(),
1362 : errmsg("could not remove old lock file \"%s\": %m",
1363 : filename),
1364 : errhint("The file seems accidentally left over, but "
1365 : "it could not be removed. Please remove the file "
1366 : "by hand and try again.")));
1367 : }
1368 :
1369 : /*
1370 : * Successfully created the file, now fill it. See comment in pidfile.h
1371 : * about the contents. Note that we write the same first five lines into
1372 : * both datadir and socket lockfiles; although more stuff may get added to
1373 : * the datadir lockfile later.
1374 : */
1375 3264 : snprintf(buffer, sizeof(buffer), "%d\n%s\n%ld\n%d\n%s\n",
1376 : amPostmaster ? (int) my_pid : -((int) my_pid),
1377 : DataDir,
1378 : (long) MyStartTime,
1379 : PostPortNumber,
1380 : socketDir);
1381 :
1382 : /*
1383 : * In a standalone backend, the next line (LOCK_FILE_LINE_LISTEN_ADDR)
1384 : * will never receive data, so fill it in as empty now.
1385 : */
1386 3264 : if (isDDLock && !amPostmaster)
1387 340 : strlcat(buffer, "\n", sizeof(buffer));
1388 :
1389 3264 : errno = 0;
1390 3264 : pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_CREATE_WRITE);
1391 3264 : if (write(fd, buffer, strlen(buffer)) != strlen(buffer))
1392 : {
1393 0 : int save_errno = errno;
1394 :
1395 0 : close(fd);
1396 0 : unlink(filename);
1397 : /* if write didn't set errno, assume problem is no disk space */
1398 0 : errno = save_errno ? save_errno : ENOSPC;
1399 0 : ereport(FATAL,
1400 : (errcode_for_file_access(),
1401 : errmsg("could not write lock file \"%s\": %m", filename)));
1402 : }
1403 3264 : pgstat_report_wait_end();
1404 :
1405 3264 : pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_CREATE_SYNC);
1406 3264 : if (pg_fsync(fd) != 0)
1407 : {
1408 0 : int save_errno = errno;
1409 :
1410 0 : close(fd);
1411 0 : unlink(filename);
1412 0 : errno = save_errno;
1413 0 : ereport(FATAL,
1414 : (errcode_for_file_access(),
1415 : errmsg("could not write lock file \"%s\": %m", filename)));
1416 : }
1417 3264 : pgstat_report_wait_end();
1418 3264 : if (close(fd) != 0)
1419 : {
1420 0 : int save_errno = errno;
1421 :
1422 0 : unlink(filename);
1423 0 : errno = save_errno;
1424 0 : ereport(FATAL,
1425 : (errcode_for_file_access(),
1426 : errmsg("could not write lock file \"%s\": %m", filename)));
1427 : }
1428 :
1429 : /*
1430 : * Arrange to unlink the lock file(s) at proc_exit. If this is the first
1431 : * one, set up the on_proc_exit function to do it; then add this lock file
1432 : * to the list of files to unlink.
1433 : */
1434 3264 : if (lock_files == NIL)
1435 1808 : on_proc_exit(UnlinkLockFiles, 0);
1436 :
1437 : /*
1438 : * Use lcons so that the lock files are unlinked in reverse order of
1439 : * creation; this is critical!
1440 : */
1441 3264 : lock_files = lcons(pstrdup(filename), lock_files);
1442 3264 : }
1443 :
1444 : /*
1445 : * Create the data directory lockfile.
1446 : *
1447 : * When this is called, we must have already switched the working
1448 : * directory to DataDir, so we can just use a relative path. This
1449 : * helps ensure that we are locking the directory we should be.
1450 : *
1451 : * Note that the socket directory path line is initially written as empty.
1452 : * postmaster.c will rewrite it upon creating the first Unix socket.
1453 : */
1454 : void
1455 1812 : CreateDataDirLockFile(bool amPostmaster)
1456 : {
1457 1812 : CreateLockFile(DIRECTORY_LOCK_FILE, amPostmaster, "", true, DataDir);
1458 1808 : }
1459 :
1460 : /*
1461 : * Create a lockfile for the specified Unix socket file.
1462 : */
1463 : void
1464 1456 : CreateSocketLockFile(const char *socketfile, bool amPostmaster,
1465 : const char *socketDir)
1466 : {
1467 : char lockfile[MAXPGPATH];
1468 :
1469 1456 : snprintf(lockfile, sizeof(lockfile), "%s.lock", socketfile);
1470 1456 : CreateLockFile(lockfile, amPostmaster, socketDir, false, socketfile);
1471 1456 : }
1472 :
1473 : /*
1474 : * TouchSocketLockFiles -- mark socket lock files as recently accessed
1475 : *
1476 : * This routine should be called every so often to ensure that the socket
1477 : * lock files have a recent mod or access date. That saves them
1478 : * from being removed by overenthusiastic /tmp-directory-cleaner daemons.
1479 : * (Another reason we should never have put the socket file in /tmp...)
1480 : */
1481 : void
1482 0 : TouchSocketLockFiles(void)
1483 : {
1484 : ListCell *l;
1485 :
1486 0 : foreach(l, lock_files)
1487 : {
1488 0 : char *socketLockFile = (char *) lfirst(l);
1489 :
1490 : /* No need to touch the data directory lock file, we trust */
1491 0 : if (strcmp(socketLockFile, DIRECTORY_LOCK_FILE) == 0)
1492 0 : continue;
1493 :
1494 : /* we just ignore any error here */
1495 0 : (void) utime(socketLockFile, NULL);
1496 : }
1497 0 : }
1498 :
1499 :
1500 : /*
1501 : * Add (or replace) a line in the data directory lock file.
1502 : * The given string should not include a trailing newline.
1503 : *
1504 : * Note: because we don't truncate the file, if we were to rewrite a line
1505 : * with less data than it had before, there would be garbage after the last
1506 : * line. While we could fix that by adding a truncate call, that would make
1507 : * the file update non-atomic, which we'd rather avoid. Therefore, callers
1508 : * should endeavor never to shorten a line once it's been written.
1509 : */
1510 : void
1511 9182 : AddToDataDirLockFile(int target_line, const char *str)
1512 : {
1513 : int fd;
1514 : int len;
1515 : int lineno;
1516 : char *srcptr;
1517 : char *destptr;
1518 : char srcbuffer[BLCKSZ];
1519 : char destbuffer[BLCKSZ];
1520 :
1521 9182 : fd = open(DIRECTORY_LOCK_FILE, O_RDWR | PG_BINARY, 0);
1522 9182 : if (fd < 0)
1523 : {
1524 0 : ereport(LOG,
1525 : (errcode_for_file_access(),
1526 : errmsg("could not open file \"%s\": %m",
1527 : DIRECTORY_LOCK_FILE)));
1528 0 : return;
1529 : }
1530 9182 : pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_ADDTODATADIR_READ);
1531 9182 : len = read(fd, srcbuffer, sizeof(srcbuffer) - 1);
1532 9182 : pgstat_report_wait_end();
1533 9182 : if (len < 0)
1534 : {
1535 0 : ereport(LOG,
1536 : (errcode_for_file_access(),
1537 : errmsg("could not read from file \"%s\": %m",
1538 : DIRECTORY_LOCK_FILE)));
1539 0 : close(fd);
1540 0 : return;
1541 : }
1542 9182 : srcbuffer[len] = '\0';
1543 :
1544 : /*
1545 : * Advance over lines we are not supposed to rewrite, then copy them to
1546 : * destbuffer.
1547 : */
1548 9182 : srcptr = srcbuffer;
1549 62910 : for (lineno = 1; lineno < target_line; lineno++)
1550 : {
1551 55186 : char *eol = strchr(srcptr, '\n');
1552 :
1553 55186 : if (eol == NULL)
1554 1458 : break; /* not enough lines in file yet */
1555 53728 : srcptr = eol + 1;
1556 : }
1557 9182 : memcpy(destbuffer, srcbuffer, srcptr - srcbuffer);
1558 9182 : destptr = destbuffer + (srcptr - srcbuffer);
1559 :
1560 : /*
1561 : * Fill in any missing lines before the target line, in case lines are
1562 : * added to the file out of order.
1563 : */
1564 10640 : for (; lineno < target_line; lineno++)
1565 : {
1566 1458 : if (destptr < destbuffer + sizeof(destbuffer))
1567 1458 : *destptr++ = '\n';
1568 : }
1569 :
1570 : /*
1571 : * Write or rewrite the target line.
1572 : */
1573 9182 : snprintf(destptr, destbuffer + sizeof(destbuffer) - destptr, "%s\n", str);
1574 9182 : destptr += strlen(destptr);
1575 :
1576 : /*
1577 : * If there are more lines in the old file, append them to destbuffer.
1578 : */
1579 9182 : if ((srcptr = strchr(srcptr, '\n')) != NULL)
1580 : {
1581 5928 : srcptr++;
1582 5928 : snprintf(destptr, destbuffer + sizeof(destbuffer) - destptr, "%s",
1583 : srcptr);
1584 : }
1585 :
1586 : /*
1587 : * And rewrite the data. Since we write in a single kernel call, this
1588 : * update should appear atomic to onlookers.
1589 : */
1590 9182 : len = strlen(destbuffer);
1591 9182 : errno = 0;
1592 9182 : pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_ADDTODATADIR_WRITE);
1593 9182 : if (pg_pwrite(fd, destbuffer, len, 0) != len)
1594 : {
1595 0 : pgstat_report_wait_end();
1596 : /* if write didn't set errno, assume problem is no disk space */
1597 0 : if (errno == 0)
1598 0 : errno = ENOSPC;
1599 0 : ereport(LOG,
1600 : (errcode_for_file_access(),
1601 : errmsg("could not write to file \"%s\": %m",
1602 : DIRECTORY_LOCK_FILE)));
1603 0 : close(fd);
1604 0 : return;
1605 : }
1606 9182 : pgstat_report_wait_end();
1607 9182 : pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_ADDTODATADIR_SYNC);
1608 9182 : if (pg_fsync(fd) != 0)
1609 : {
1610 0 : ereport(LOG,
1611 : (errcode_for_file_access(),
1612 : errmsg("could not write to file \"%s\": %m",
1613 : DIRECTORY_LOCK_FILE)));
1614 : }
1615 9182 : pgstat_report_wait_end();
1616 9182 : if (close(fd) != 0)
1617 : {
1618 0 : ereport(LOG,
1619 : (errcode_for_file_access(),
1620 : errmsg("could not write to file \"%s\": %m",
1621 : DIRECTORY_LOCK_FILE)));
1622 : }
1623 : }
1624 :
1625 :
1626 : /*
1627 : * Recheck that the data directory lock file still exists with expected
1628 : * content. Return true if the lock file appears OK, false if it isn't.
1629 : *
1630 : * We call this periodically in the postmaster. The idea is that if the
1631 : * lock file has been removed or replaced by another postmaster, we should
1632 : * do a panic database shutdown. Therefore, we should return true if there
1633 : * is any doubt: we do not want to cause a panic shutdown unnecessarily.
1634 : * Transient failures like EINTR or ENFILE should not cause us to fail.
1635 : * (If there really is something wrong, we'll detect it on a future recheck.)
1636 : */
1637 : bool
1638 22 : RecheckDataDirLockFile(void)
1639 : {
1640 : int fd;
1641 : int len;
1642 : long file_pid;
1643 : char buffer[BLCKSZ];
1644 :
1645 22 : fd = open(DIRECTORY_LOCK_FILE, O_RDWR | PG_BINARY, 0);
1646 22 : if (fd < 0)
1647 : {
1648 : /*
1649 : * There are many foreseeable false-positive error conditions. For
1650 : * safety, fail only on enumerated clearly-something-is-wrong
1651 : * conditions.
1652 : */
1653 0 : switch (errno)
1654 : {
1655 0 : case ENOENT:
1656 : case ENOTDIR:
1657 : /* disaster */
1658 0 : ereport(LOG,
1659 : (errcode_for_file_access(),
1660 : errmsg("could not open file \"%s\": %m",
1661 : DIRECTORY_LOCK_FILE)));
1662 0 : return false;
1663 0 : default:
1664 : /* non-fatal, at least for now */
1665 0 : ereport(LOG,
1666 : (errcode_for_file_access(),
1667 : errmsg("could not open file \"%s\": %m; continuing anyway",
1668 : DIRECTORY_LOCK_FILE)));
1669 0 : return true;
1670 : }
1671 : }
1672 22 : pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_RECHECKDATADIR_READ);
1673 22 : len = read(fd, buffer, sizeof(buffer) - 1);
1674 22 : pgstat_report_wait_end();
1675 22 : if (len < 0)
1676 : {
1677 0 : ereport(LOG,
1678 : (errcode_for_file_access(),
1679 : errmsg("could not read from file \"%s\": %m",
1680 : DIRECTORY_LOCK_FILE)));
1681 0 : close(fd);
1682 0 : return true; /* treat read failure as nonfatal */
1683 : }
1684 22 : buffer[len] = '\0';
1685 22 : close(fd);
1686 22 : file_pid = atol(buffer);
1687 22 : if (file_pid == getpid())
1688 22 : return true; /* all is well */
1689 :
1690 : /* Trouble: someone's overwritten the lock file */
1691 0 : ereport(LOG,
1692 : (errmsg("lock file \"%s\" contains wrong PID: %ld instead of %ld",
1693 : DIRECTORY_LOCK_FILE, file_pid, (long) getpid())));
1694 0 : return false;
1695 : }
1696 :
1697 :
1698 : /*-------------------------------------------------------------------------
1699 : * Version checking support
1700 : *-------------------------------------------------------------------------
1701 : */
1702 :
1703 : /*
1704 : * Determine whether the PG_VERSION file in directory `path' indicates
1705 : * a data version compatible with the version of this program.
1706 : *
1707 : * If compatible, return. Otherwise, ereport(FATAL).
1708 : */
1709 : void
1710 28422 : ValidatePgVersion(const char *path)
1711 : {
1712 : char full_path[MAXPGPATH];
1713 : FILE *file;
1714 : int ret;
1715 : long file_major;
1716 : long my_major;
1717 : char *endptr;
1718 : char file_version_string[64];
1719 28422 : const char *my_version_string = PG_VERSION;
1720 :
1721 28422 : my_major = strtol(my_version_string, &endptr, 10);
1722 :
1723 28422 : snprintf(full_path, sizeof(full_path), "%s/PG_VERSION", path);
1724 :
1725 28422 : file = AllocateFile(full_path, "r");
1726 28422 : if (!file)
1727 : {
1728 0 : if (errno == ENOENT)
1729 0 : ereport(FATAL,
1730 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1731 : errmsg("\"%s\" is not a valid data directory",
1732 : path),
1733 : errdetail("File \"%s\" is missing.", full_path)));
1734 : else
1735 0 : ereport(FATAL,
1736 : (errcode_for_file_access(),
1737 : errmsg("could not open file \"%s\": %m", full_path)));
1738 : }
1739 :
1740 28422 : file_version_string[0] = '\0';
1741 28422 : ret = fscanf(file, "%63s", file_version_string);
1742 28422 : file_major = strtol(file_version_string, &endptr, 10);
1743 :
1744 28422 : if (ret != 1 || endptr == file_version_string)
1745 0 : ereport(FATAL,
1746 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1747 : errmsg("\"%s\" is not a valid data directory",
1748 : path),
1749 : errdetail("File \"%s\" does not contain valid data.",
1750 : full_path),
1751 : errhint("You might need to initdb.")));
1752 :
1753 28422 : FreeFile(file);
1754 :
1755 28422 : if (my_major != file_major)
1756 0 : ereport(FATAL,
1757 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1758 : errmsg("database files are incompatible with server"),
1759 : errdetail("The data directory was initialized by PostgreSQL version %s, "
1760 : "which is not compatible with this version %s.",
1761 : file_version_string, my_version_string)));
1762 28422 : }
1763 :
1764 : /*-------------------------------------------------------------------------
1765 : * Library preload support
1766 : *-------------------------------------------------------------------------
1767 : */
1768 :
1769 : /*
1770 : * GUC variables: lists of library names to be preloaded at postmaster
1771 : * start and at backend start
1772 : */
1773 : char *session_preload_libraries_string = NULL;
1774 : char *shared_preload_libraries_string = NULL;
1775 : char *local_preload_libraries_string = NULL;
1776 :
1777 : /* Flag telling that we are loading shared_preload_libraries */
1778 : bool process_shared_preload_libraries_in_progress = false;
1779 : bool process_shared_preload_libraries_done = false;
1780 :
1781 : shmem_request_hook_type shmem_request_hook = NULL;
1782 : bool process_shmem_requests_in_progress = false;
1783 :
1784 : /*
1785 : * load the shared libraries listed in 'libraries'
1786 : *
1787 : * 'gucname': name of GUC variable, for error reports
1788 : * 'restricted': if true, force libraries to be in $libdir/plugins/
1789 : */
1790 : static void
1791 45552 : load_libraries(const char *libraries, const char *gucname, bool restricted)
1792 : {
1793 : char *rawstring;
1794 : List *elemlist;
1795 : ListCell *l;
1796 :
1797 45552 : if (libraries == NULL || libraries[0] == '\0')
1798 45488 : return; /* nothing to do */
1799 :
1800 : /* Need a modifiable copy of string */
1801 64 : rawstring = pstrdup(libraries);
1802 :
1803 : /* Parse string into list of filename paths */
1804 64 : if (!SplitDirectoriesString(rawstring, ',', &elemlist))
1805 : {
1806 : /* syntax error in list */
1807 0 : list_free_deep(elemlist);
1808 0 : pfree(rawstring);
1809 0 : ereport(LOG,
1810 : (errcode(ERRCODE_SYNTAX_ERROR),
1811 : errmsg("invalid list syntax in parameter \"%s\"",
1812 : gucname)));
1813 0 : return;
1814 : }
1815 :
1816 128 : foreach(l, elemlist)
1817 : {
1818 : /* Note that filename was already canonicalized */
1819 64 : char *filename = (char *) lfirst(l);
1820 64 : char *expanded = NULL;
1821 :
1822 : /* If restricting, insert $libdir/plugins if not mentioned already */
1823 64 : if (restricted && first_dir_separator(filename) == NULL)
1824 : {
1825 0 : expanded = psprintf("$libdir/plugins/%s", filename);
1826 0 : filename = expanded;
1827 : }
1828 64 : load_file(filename, restricted);
1829 64 : ereport(DEBUG1,
1830 : (errmsg_internal("loaded library \"%s\"", filename)));
1831 64 : if (expanded)
1832 0 : pfree(expanded);
1833 : }
1834 :
1835 64 : list_free_deep(elemlist);
1836 64 : pfree(rawstring);
1837 : }
1838 :
1839 : /*
1840 : * process any libraries that should be preloaded at postmaster start
1841 : */
1842 : void
1843 1568 : process_shared_preload_libraries(void)
1844 : {
1845 1568 : process_shared_preload_libraries_in_progress = true;
1846 1568 : load_libraries(shared_preload_libraries_string,
1847 : "shared_preload_libraries",
1848 : false);
1849 1568 : process_shared_preload_libraries_in_progress = false;
1850 1568 : process_shared_preload_libraries_done = true;
1851 1568 : }
1852 :
1853 : /*
1854 : * process any libraries that should be preloaded at backend start
1855 : */
1856 : void
1857 21992 : process_session_preload_libraries(void)
1858 : {
1859 21992 : load_libraries(session_preload_libraries_string,
1860 : "session_preload_libraries",
1861 : false);
1862 21992 : load_libraries(local_preload_libraries_string,
1863 : "local_preload_libraries",
1864 : true);
1865 21992 : }
1866 :
1867 : /*
1868 : * process any shared memory requests from preloaded libraries
1869 : */
1870 : void
1871 1562 : process_shmem_requests(void)
1872 : {
1873 1562 : process_shmem_requests_in_progress = true;
1874 1562 : if (shmem_request_hook)
1875 16 : shmem_request_hook();
1876 1562 : process_shmem_requests_in_progress = false;
1877 1562 : }
1878 :
1879 : void
1880 3526 : pg_bindtextdomain(const char *domain)
1881 : {
1882 : #ifdef ENABLE_NLS
1883 3526 : if (my_exec_path[0] != '\0')
1884 : {
1885 : char locale_path[MAXPGPATH];
1886 :
1887 3526 : get_locale_path(my_exec_path, locale_path);
1888 3526 : bindtextdomain(domain, locale_path);
1889 3526 : pg_bind_textdomain_codeset(domain);
1890 : }
1891 : #endif
1892 3526 : }
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