Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * Utility routines for SQL dumping
4 : *
5 : * Basically this is stuff that is useful in both pg_dump and pg_dumpall.
6 : *
7 : *
8 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
9 : * Portions Copyright (c) 1994, Regents of the University of California
10 : *
11 : * src/bin/pg_dump/dumputils.c
12 : *
13 : *-------------------------------------------------------------------------
14 : */
15 : #include "postgres_fe.h"
16 :
17 : #include <ctype.h>
18 :
19 : #include "common/file_perm.h"
20 : #include "common/logging.h"
21 : #include "dumputils.h"
22 : #include "fe_utils/string_utils.h"
23 :
24 : static const char restrict_chars[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
25 :
26 : static bool parseAclItem(const char *item, const char *type,
27 : const char *name, const char *subname, int remoteVersion,
28 : PQExpBuffer grantee, PQExpBuffer grantor,
29 : PQExpBuffer privs, PQExpBuffer privswgo);
30 : static char *dequoteAclUserName(PQExpBuffer output, char *input);
31 : static void AddAcl(PQExpBuffer aclbuf, const char *keyword,
32 : const char *subname);
33 :
34 :
35 : /*
36 : * Sanitize a string to be included in an SQL comment or TOC listing, by
37 : * replacing any newlines with spaces. This ensures each logical output line
38 : * is in fact one physical output line, to prevent corruption of the dump
39 : * (which could, in the worst case, present an SQL injection vulnerability
40 : * if someone were to incautiously load a dump containing objects with
41 : * maliciously crafted names).
42 : *
43 : * The result is a freshly malloc'd string. If the input string is NULL,
44 : * return a malloc'ed empty string, unless want_hyphen, in which case return a
45 : * malloc'ed hyphen.
46 : *
47 : * Note that we currently don't bother to quote names, meaning that the name
48 : * fields aren't automatically parseable. "pg_restore -L" doesn't care because
49 : * it only examines the dumpId field, but someday we might want to try harder.
50 : */
51 : char *
52 236276 : sanitize_line(const char *str, bool want_hyphen)
53 : {
54 : char *result;
55 : char *s;
56 :
57 236276 : if (!str)
58 9906 : return pg_strdup(want_hyphen ? "-" : "");
59 :
60 226370 : result = pg_strdup(str);
61 :
62 2936804 : for (s = result; *s != '\0'; s++)
63 : {
64 2710434 : if (*s == '\n' || *s == '\r')
65 428 : *s = ' ';
66 : }
67 :
68 226370 : return result;
69 : }
70 :
71 :
72 : /*
73 : * Build GRANT/REVOKE command(s) for an object.
74 : *
75 : * name: the object name, in the form to use in the commands (already quoted)
76 : * subname: the sub-object name, if any (already quoted); NULL if none
77 : * nspname: the namespace the object is in (NULL if none); not pre-quoted
78 : * type: the object type (as seen in GRANT command: must be one of
79 : * TABLE, SEQUENCE, FUNCTION, PROCEDURE, LANGUAGE, SCHEMA, DATABASE, TABLESPACE,
80 : * FOREIGN DATA WRAPPER, SERVER, PARAMETER or LARGE OBJECT)
81 : * acls: the ACL string fetched from the database
82 : * baseacls: the initial ACL string for this object
83 : * owner: username of object owner (will be passed through fmtId); can be
84 : * NULL or empty string to indicate "no owner known"
85 : * prefix: string to prefix to each generated command; typically empty
86 : * remoteVersion: version of database
87 : *
88 : * Returns true if okay, false if could not parse the acl string.
89 : * The resulting commands (if any) are appended to the contents of 'sql'.
90 : *
91 : * baseacls is typically the result of acldefault() for the object's type
92 : * and owner. However, if there is a pg_init_privs entry for the object,
93 : * it should instead be the initprivs ACLs. When acls is itself a
94 : * pg_init_privs entry, baseacls is what to dump that relative to; then
95 : * it can be either an acldefault() value or an empty ACL "{}".
96 : *
97 : * Note: when processing a default ACL, prefix is "ALTER DEFAULT PRIVILEGES "
98 : * or something similar, and name is an empty string.
99 : *
100 : * Note: beware of passing a fmtId() result directly as 'name' or 'subname',
101 : * since this routine uses fmtId() internally.
102 : */
103 : bool
104 55072 : buildACLCommands(const char *name, const char *subname, const char *nspname,
105 : const char *type, const char *acls, const char *baseacls,
106 : const char *owner, const char *prefix, int remoteVersion,
107 : PQExpBuffer sql)
108 : {
109 55072 : bool ok = true;
110 55072 : char **aclitems = NULL;
111 55072 : char **baseitems = NULL;
112 55072 : char **grantitems = NULL;
113 55072 : char **revokeitems = NULL;
114 55072 : int naclitems = 0;
115 55072 : int nbaseitems = 0;
116 55072 : int ngrantitems = 0;
117 55072 : int nrevokeitems = 0;
118 : int i;
119 : PQExpBuffer grantee,
120 : grantor,
121 : privs,
122 : privswgo;
123 : PQExpBuffer firstsql,
124 : secondsql;
125 :
126 : /*
127 : * If the acl was NULL (initial default state), we need do nothing. Note
128 : * that this is distinguishable from all-privileges-revoked, which will
129 : * look like an empty array ("{}").
130 : */
131 55072 : if (acls == NULL || *acls == '\0')
132 224 : return true; /* object has default permissions */
133 :
134 : /* treat empty-string owner same as NULL */
135 54848 : if (owner && *owner == '\0')
136 0 : owner = NULL;
137 :
138 : /* Parse the acls array */
139 54848 : if (!parsePGArray(acls, &aclitems, &naclitems))
140 : {
141 0 : free(aclitems);
142 0 : return false;
143 : }
144 :
145 : /* Parse the baseacls too */
146 54848 : if (!parsePGArray(baseacls, &baseitems, &nbaseitems))
147 : {
148 0 : free(aclitems);
149 0 : free(baseitems);
150 0 : return false;
151 : }
152 :
153 : /*
154 : * Compare the actual ACL with the base ACL, extracting the privileges
155 : * that need to be granted (i.e., are in the actual ACL but not the base
156 : * ACL) and the ones that need to be revoked (the reverse). We use plain
157 : * string comparisons to check for matches. In principle that could be
158 : * fooled by extraneous issues such as whitespace, but since all these
159 : * strings are the work of aclitemout(), it should be OK in practice.
160 : * Besides, a false mismatch will just cause the output to be a little
161 : * more verbose than it really needed to be.
162 : */
163 54848 : grantitems = (char **) pg_malloc(naclitems * sizeof(char *));
164 152654 : for (i = 0; i < naclitems; i++)
165 : {
166 97806 : bool found = false;
167 :
168 141802 : for (int j = 0; j < nbaseitems; j++)
169 : {
170 138092 : if (strcmp(aclitems[i], baseitems[j]) == 0)
171 : {
172 94096 : found = true;
173 94096 : break;
174 : }
175 : }
176 97806 : if (!found)
177 3710 : grantitems[ngrantitems++] = aclitems[i];
178 : }
179 54848 : revokeitems = (char **) pg_malloc(nbaseitems * sizeof(char *));
180 149694 : for (i = 0; i < nbaseitems; i++)
181 : {
182 94846 : bool found = false;
183 :
184 137508 : for (int j = 0; j < naclitems; j++)
185 : {
186 136758 : if (strcmp(baseitems[i], aclitems[j]) == 0)
187 : {
188 94096 : found = true;
189 94096 : break;
190 : }
191 : }
192 94846 : if (!found)
193 750 : revokeitems[nrevokeitems++] = baseitems[i];
194 : }
195 :
196 : /* Prepare working buffers */
197 54848 : grantee = createPQExpBuffer();
198 54848 : grantor = createPQExpBuffer();
199 54848 : privs = createPQExpBuffer();
200 54848 : privswgo = createPQExpBuffer();
201 :
202 : /*
203 : * At the end, these two will be pasted together to form the result.
204 : */
205 54848 : firstsql = createPQExpBuffer();
206 54848 : secondsql = createPQExpBuffer();
207 :
208 : /*
209 : * Build REVOKE statements for ACLs listed in revokeitems[].
210 : */
211 55598 : for (i = 0; i < nrevokeitems; i++)
212 : {
213 750 : if (!parseAclItem(revokeitems[i],
214 : type, name, subname, remoteVersion,
215 : grantee, grantor, privs, NULL))
216 : {
217 0 : ok = false;
218 0 : break;
219 : }
220 :
221 750 : if (privs->len > 0)
222 : {
223 750 : appendPQExpBuffer(firstsql, "%sREVOKE %s ON %s ",
224 : prefix, privs->data, type);
225 750 : if (nspname && *nspname)
226 418 : appendPQExpBuffer(firstsql, "%s.", fmtId(nspname));
227 750 : if (name && *name)
228 598 : appendPQExpBuffer(firstsql, "%s ", name);
229 750 : appendPQExpBufferStr(firstsql, "FROM ");
230 750 : if (grantee->len == 0)
231 384 : appendPQExpBufferStr(firstsql, "PUBLIC;\n");
232 : else
233 366 : appendPQExpBuffer(firstsql, "%s;\n",
234 366 : fmtId(grantee->data));
235 : }
236 : }
237 :
238 : /*
239 : * At this point we have issued REVOKE statements for all initial and
240 : * default privileges that are no longer present on the object, so we are
241 : * almost ready to GRANT the privileges listed in grantitems[].
242 : *
243 : * We still need some hacking though to cover the case where new default
244 : * public privileges are added in new versions: the REVOKE ALL will revoke
245 : * them, leading to behavior different from what the old version had,
246 : * which is generally not what's wanted. So add back default privs if the
247 : * source database is too old to have had that particular priv. (As of
248 : * right now, no such cases exist in supported versions.)
249 : */
250 :
251 : /*
252 : * Scan individual ACL items to be granted.
253 : *
254 : * The order in which privileges appear in the ACL string (the order they
255 : * have been GRANT'd in, which the backend maintains) must be preserved to
256 : * ensure that GRANTs WITH GRANT OPTION and subsequent GRANTs based on
257 : * those are dumped in the correct order. However, some old server
258 : * versions will show grants to PUBLIC before the owner's own grants; for
259 : * consistency's sake, force the owner's grants to be output first.
260 : */
261 58558 : for (i = 0; i < ngrantitems; i++)
262 : {
263 3710 : if (parseAclItem(grantitems[i], type, name, subname, remoteVersion,
264 : grantee, grantor, privs, privswgo))
265 : {
266 : /*
267 : * If the grantor isn't the owner, we'll need to use SET SESSION
268 : * AUTHORIZATION to become the grantor. Issue the SET/RESET only
269 : * if there's something useful to do.
270 : */
271 3710 : if (privs->len > 0 || privswgo->len > 0)
272 : {
273 : PQExpBuffer thissql;
274 :
275 : /* Set owner as grantor if that's not explicit in the ACL */
276 3710 : if (grantor->len == 0 && owner)
277 0 : printfPQExpBuffer(grantor, "%s", owner);
278 :
279 : /* Make sure owner's own grants are output before others */
280 3710 : if (owner &&
281 3710 : strcmp(grantee->data, owner) == 0 &&
282 254 : strcmp(grantor->data, owner) == 0)
283 254 : thissql = firstsql;
284 : else
285 3456 : thissql = secondsql;
286 :
287 3710 : if (grantor->len > 0
288 3710 : && (!owner || strcmp(owner, grantor->data) != 0))
289 0 : appendPQExpBuffer(thissql, "SET SESSION AUTHORIZATION %s;\n",
290 0 : fmtId(grantor->data));
291 :
292 3710 : if (privs->len > 0)
293 : {
294 3706 : appendPQExpBuffer(thissql, "%sGRANT %s ON %s ",
295 : prefix, privs->data, type);
296 3706 : if (nspname && *nspname)
297 3170 : appendPQExpBuffer(thissql, "%s.", fmtId(nspname));
298 3706 : if (name && *name)
299 3504 : appendPQExpBuffer(thissql, "%s ", name);
300 3706 : appendPQExpBufferStr(thissql, "TO ");
301 3706 : if (grantee->len == 0)
302 2160 : appendPQExpBufferStr(thissql, "PUBLIC;\n");
303 : else
304 1546 : appendPQExpBuffer(thissql, "%s;\n", fmtId(grantee->data));
305 : }
306 3710 : if (privswgo->len > 0)
307 : {
308 40 : appendPQExpBuffer(thissql, "%sGRANT %s ON %s ",
309 : prefix, privswgo->data, type);
310 40 : if (nspname && *nspname)
311 38 : appendPQExpBuffer(thissql, "%s.", fmtId(nspname));
312 40 : if (name && *name)
313 40 : appendPQExpBuffer(thissql, "%s ", name);
314 40 : appendPQExpBufferStr(thissql, "TO ");
315 40 : if (grantee->len == 0)
316 0 : appendPQExpBufferStr(thissql, "PUBLIC");
317 : else
318 40 : appendPQExpBufferStr(thissql, fmtId(grantee->data));
319 40 : appendPQExpBufferStr(thissql, " WITH GRANT OPTION;\n");
320 : }
321 :
322 3710 : if (grantor->len > 0
323 3710 : && (!owner || strcmp(owner, grantor->data) != 0))
324 0 : appendPQExpBufferStr(thissql, "RESET SESSION AUTHORIZATION;\n");
325 : }
326 : }
327 : else
328 : {
329 : /* parseAclItem failed, give up */
330 0 : ok = false;
331 0 : break;
332 : }
333 : }
334 :
335 54848 : destroyPQExpBuffer(grantee);
336 54848 : destroyPQExpBuffer(grantor);
337 54848 : destroyPQExpBuffer(privs);
338 54848 : destroyPQExpBuffer(privswgo);
339 :
340 54848 : appendPQExpBuffer(sql, "%s%s", firstsql->data, secondsql->data);
341 54848 : destroyPQExpBuffer(firstsql);
342 54848 : destroyPQExpBuffer(secondsql);
343 :
344 54848 : free(aclitems);
345 54848 : free(baseitems);
346 54848 : free(grantitems);
347 54848 : free(revokeitems);
348 :
349 54848 : return ok;
350 : }
351 :
352 : /*
353 : * Build ALTER DEFAULT PRIVILEGES command(s) for a single pg_default_acl entry.
354 : *
355 : * type: the object type (TABLES, FUNCTIONS, etc)
356 : * nspname: schema name, or NULL for global default privileges
357 : * acls: the ACL string fetched from the database
358 : * acldefault: the appropriate default ACL for the object type and owner
359 : * owner: username of privileges owner (will be passed through fmtId)
360 : * remoteVersion: version of database
361 : *
362 : * Returns true if okay, false if could not parse the acl string.
363 : * The resulting commands (if any) are appended to the contents of 'sql'.
364 : */
365 : bool
366 288 : buildDefaultACLCommands(const char *type, const char *nspname,
367 : const char *acls, const char *acldefault,
368 : const char *owner,
369 : int remoteVersion,
370 : PQExpBuffer sql)
371 : {
372 : PQExpBuffer prefix;
373 :
374 288 : prefix = createPQExpBuffer();
375 :
376 : /*
377 : * We incorporate the target role directly into the command, rather than
378 : * playing around with SET ROLE or anything like that. This is so that a
379 : * permissions error leads to nothing happening, rather than changing
380 : * default privileges for the wrong user.
381 : */
382 288 : appendPQExpBuffer(prefix, "ALTER DEFAULT PRIVILEGES FOR ROLE %s ",
383 : fmtId(owner));
384 288 : if (nspname)
385 136 : appendPQExpBuffer(prefix, "IN SCHEMA %s ", fmtId(nspname));
386 :
387 : /*
388 : * There's no such thing as initprivs for a default ACL, so the base ACL
389 : * is always just the object-type-specific default.
390 : */
391 288 : if (!buildACLCommands("", NULL, NULL, type,
392 : acls, acldefault, owner,
393 288 : prefix->data, remoteVersion, sql))
394 : {
395 0 : destroyPQExpBuffer(prefix);
396 0 : return false;
397 : }
398 :
399 288 : destroyPQExpBuffer(prefix);
400 :
401 288 : return true;
402 : }
403 :
404 : /*
405 : * This will parse an aclitem string, having the general form
406 : * username=privilegecodes/grantor
407 : *
408 : * Returns true on success, false on parse error. On success, the components
409 : * of the string are returned in the PQExpBuffer parameters.
410 : *
411 : * The returned grantee string will be the dequoted username, or an empty
412 : * string in the case of a grant to PUBLIC. The returned grantor is the
413 : * dequoted grantor name. Privilege characters are translated to GRANT/REVOKE
414 : * comma-separated privileges lists. If "privswgo" is non-NULL, the result is
415 : * separate lists for privileges with grant option ("privswgo") and without
416 : * ("privs"). Otherwise, "privs" bears every relevant privilege, ignoring the
417 : * grant option distinction.
418 : *
419 : * Note: for cross-version compatibility, it's important to use ALL to
420 : * represent the privilege sets whenever appropriate.
421 : */
422 : static bool
423 4460 : parseAclItem(const char *item, const char *type,
424 : const char *name, const char *subname, int remoteVersion,
425 : PQExpBuffer grantee, PQExpBuffer grantor,
426 : PQExpBuffer privs, PQExpBuffer privswgo)
427 : {
428 : char *buf;
429 4460 : bool all_with_go = true;
430 4460 : bool all_without_go = true;
431 : char *eqpos;
432 : char *slpos;
433 : char *pos;
434 :
435 4460 : buf = pg_strdup(item);
436 :
437 : /* user or group name is string up to = */
438 4460 : eqpos = dequoteAclUserName(grantee, buf);
439 4460 : if (*eqpos != '=')
440 : {
441 0 : pg_free(buf);
442 0 : return false;
443 : }
444 :
445 : /* grantor should appear after / */
446 4460 : slpos = strchr(eqpos + 1, '/');
447 4460 : if (slpos)
448 : {
449 4460 : *slpos++ = '\0';
450 4460 : slpos = dequoteAclUserName(grantor, slpos);
451 4460 : if (*slpos != '\0')
452 : {
453 0 : pg_free(buf);
454 0 : return false;
455 : }
456 : }
457 : else
458 : {
459 0 : pg_free(buf);
460 0 : return false;
461 : }
462 :
463 : /* privilege codes */
464 : #define CONVERT_PRIV(code, keywd) \
465 : do { \
466 : if ((pos = strchr(eqpos + 1, code))) \
467 : { \
468 : if (*(pos + 1) == '*' && privswgo != NULL) \
469 : { \
470 : AddAcl(privswgo, keywd, subname); \
471 : all_without_go = false; \
472 : } \
473 : else \
474 : { \
475 : AddAcl(privs, keywd, subname); \
476 : all_with_go = false; \
477 : } \
478 : } \
479 : else \
480 : all_with_go = all_without_go = false; \
481 : } while (0)
482 :
483 4460 : resetPQExpBuffer(privs);
484 4460 : resetPQExpBuffer(privswgo);
485 :
486 4460 : if (strcmp(type, "TABLE") == 0 || strcmp(type, "SEQUENCE") == 0 ||
487 1456 : strcmp(type, "TABLES") == 0 || strcmp(type, "SEQUENCES") == 0)
488 : {
489 3204 : CONVERT_PRIV('r', "SELECT");
490 :
491 3204 : if (strcmp(type, "SEQUENCE") == 0 ||
492 3094 : strcmp(type, "SEQUENCES") == 0)
493 : /* sequence only */
494 110 : CONVERT_PRIV('U', "USAGE");
495 : else
496 : {
497 : /* table only */
498 3094 : CONVERT_PRIV('a', "INSERT");
499 3094 : CONVERT_PRIV('x', "REFERENCES");
500 : /* rest are not applicable to columns */
501 3094 : if (subname == NULL)
502 : {
503 806 : CONVERT_PRIV('d', "DELETE");
504 806 : CONVERT_PRIV('t', "TRIGGER");
505 806 : CONVERT_PRIV('D', "TRUNCATE");
506 806 : CONVERT_PRIV('m', "MAINTAIN");
507 : }
508 : }
509 :
510 : /* UPDATE */
511 3204 : CONVERT_PRIV('w', "UPDATE");
512 : }
513 1256 : else if (strcmp(type, "FUNCTION") == 0 ||
514 944 : strcmp(type, "FUNCTIONS") == 0)
515 446 : CONVERT_PRIV('X', "EXECUTE");
516 810 : else if (strcmp(type, "PROCEDURE") == 0 ||
517 810 : strcmp(type, "PROCEDURES") == 0)
518 0 : CONVERT_PRIV('X', "EXECUTE");
519 810 : else if (strcmp(type, "LANGUAGE") == 0)
520 80 : CONVERT_PRIV('U', "USAGE");
521 730 : else if (strcmp(type, "SCHEMA") == 0 ||
522 554 : strcmp(type, "SCHEMAS") == 0)
523 : {
524 176 : CONVERT_PRIV('C', "CREATE");
525 176 : CONVERT_PRIV('U', "USAGE");
526 : }
527 554 : else if (strcmp(type, "DATABASE") == 0)
528 : {
529 52 : CONVERT_PRIV('C', "CREATE");
530 52 : CONVERT_PRIV('c', "CONNECT");
531 52 : CONVERT_PRIV('T', "TEMPORARY");
532 : }
533 502 : else if (strcmp(type, "TABLESPACE") == 0)
534 0 : CONVERT_PRIV('C', "CREATE");
535 502 : else if (strcmp(type, "TYPE") == 0 ||
536 228 : strcmp(type, "TYPES") == 0)
537 294 : CONVERT_PRIV('U', "USAGE");
538 208 : else if (strcmp(type, "FOREIGN DATA WRAPPER") == 0)
539 66 : CONVERT_PRIV('U', "USAGE");
540 142 : else if (strcmp(type, "FOREIGN SERVER") == 0)
541 66 : CONVERT_PRIV('U', "USAGE");
542 76 : else if (strcmp(type, "FOREIGN TABLE") == 0)
543 0 : CONVERT_PRIV('r', "SELECT");
544 76 : else if (strcmp(type, "PARAMETER") == 0)
545 : {
546 6 : CONVERT_PRIV('s', "SET");
547 6 : CONVERT_PRIV('A', "ALTER SYSTEM");
548 : }
549 70 : else if (strcmp(type, "LARGE OBJECT") == 0 ||
550 0 : strcmp(type, "LARGE OBJECTS") == 0)
551 : {
552 70 : CONVERT_PRIV('r', "SELECT");
553 70 : CONVERT_PRIV('w', "UPDATE");
554 : }
555 : else
556 0 : abort();
557 :
558 : #undef CONVERT_PRIV
559 :
560 4460 : if (all_with_go)
561 : {
562 4 : resetPQExpBuffer(privs);
563 4 : printfPQExpBuffer(privswgo, "ALL");
564 4 : if (subname)
565 0 : appendPQExpBuffer(privswgo, "(%s)", subname);
566 : }
567 4456 : else if (all_without_go)
568 : {
569 1208 : resetPQExpBuffer(privswgo);
570 1208 : printfPQExpBuffer(privs, "ALL");
571 1208 : if (subname)
572 0 : appendPQExpBuffer(privs, "(%s)", subname);
573 : }
574 :
575 4460 : pg_free(buf);
576 :
577 4460 : return true;
578 : }
579 :
580 : /*
581 : * Transfer the role name at *input into the output buffer, adding
582 : * quoting according to the same rules as putid() in backend's acl.c.
583 : */
584 : void
585 1074 : quoteAclUserName(PQExpBuffer output, const char *input)
586 : {
587 : const char *src;
588 1074 : bool safe = true;
589 :
590 18378 : for (src = input; *src; src++)
591 : {
592 : /* This test had better match what putid() does */
593 17622 : if (!isalnum((unsigned char) *src) && *src != '_')
594 : {
595 318 : safe = false;
596 318 : break;
597 : }
598 : }
599 1074 : if (!safe)
600 318 : appendPQExpBufferChar(output, '"');
601 21240 : for (src = input; *src; src++)
602 : {
603 : /* A double quote character in a username is encoded as "" */
604 20166 : if (*src == '"')
605 318 : appendPQExpBufferChar(output, '"');
606 20166 : appendPQExpBufferChar(output, *src);
607 : }
608 1074 : if (!safe)
609 318 : appendPQExpBufferChar(output, '"');
610 1074 : }
611 :
612 : /*
613 : * Transfer a user or group name starting at *input into the output buffer,
614 : * dequoting if needed. Returns a pointer to just past the input name.
615 : * The name is taken to end at an unquoted '=' or end of string.
616 : * Note: unlike quoteAclUserName(), this first clears the output buffer.
617 : */
618 : static char *
619 8920 : dequoteAclUserName(PQExpBuffer output, char *input)
620 : {
621 8920 : resetPQExpBuffer(output);
622 :
623 86006 : while (*input && *input != '=')
624 : {
625 : /*
626 : * If user name isn't quoted, then just add it to the output buffer
627 : */
628 77086 : if (*input != '"')
629 76886 : appendPQExpBufferChar(output, *input++);
630 : else
631 : {
632 : /* Otherwise, it's a quoted username */
633 200 : input++;
634 : /* Loop until we come across an unescaped quote */
635 4800 : while (!(*input == '"' && *(input + 1) != '"'))
636 : {
637 4600 : if (*input == '\0')
638 0 : return input; /* really a syntax error... */
639 :
640 : /*
641 : * Quoting convention is to escape " as "". Keep this code in
642 : * sync with putid() in backend's acl.c.
643 : */
644 4600 : if (*input == '"' && *(input + 1) == '"')
645 200 : input++;
646 4600 : appendPQExpBufferChar(output, *input++);
647 : }
648 200 : input++;
649 : }
650 : }
651 8920 : return input;
652 : }
653 :
654 : /*
655 : * Append a privilege keyword to a keyword list, inserting comma if needed.
656 : */
657 : static void
658 5762 : AddAcl(PQExpBuffer aclbuf, const char *keyword, const char *subname)
659 : {
660 5762 : if (aclbuf->len > 0)
661 1266 : appendPQExpBufferChar(aclbuf, ',');
662 5762 : appendPQExpBufferStr(aclbuf, keyword);
663 5762 : if (subname)
664 2288 : appendPQExpBuffer(aclbuf, "(%s)", subname);
665 5762 : }
666 :
667 :
668 : /*
669 : * buildShSecLabelQuery
670 : *
671 : * Build a query to retrieve security labels for a shared object.
672 : * The object is identified by its OID plus the name of the catalog
673 : * it can be found in (e.g., "pg_database" for database names).
674 : * The query is appended to "sql". (We don't execute it here so as to
675 : * keep this file free of assumptions about how to deal with SQL errors.)
676 : */
677 : void
678 340 : buildShSecLabelQuery(const char *catalog_name, Oid objectId,
679 : PQExpBuffer sql)
680 : {
681 340 : appendPQExpBuffer(sql,
682 : "SELECT provider, label FROM pg_catalog.pg_shseclabel "
683 : "WHERE classoid = 'pg_catalog.%s'::pg_catalog.regclass "
684 : "AND objoid = '%u'", catalog_name, objectId);
685 340 : }
686 :
687 : /*
688 : * emitShSecLabels
689 : *
690 : * Construct SECURITY LABEL commands using the data retrieved by the query
691 : * generated by buildShSecLabelQuery, and append them to "buffer".
692 : * Here, the target object is identified by its type name (e.g. "DATABASE")
693 : * and its name (not pre-quoted).
694 : */
695 : void
696 340 : emitShSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
697 : const char *objtype, const char *objname)
698 : {
699 : int i;
700 :
701 340 : for (i = 0; i < PQntuples(res); i++)
702 : {
703 0 : char *provider = PQgetvalue(res, i, 0);
704 0 : char *label = PQgetvalue(res, i, 1);
705 :
706 : /* must use fmtId result before calling it again */
707 0 : appendPQExpBuffer(buffer,
708 : "SECURITY LABEL FOR %s ON %s",
709 : fmtId(provider), objtype);
710 0 : appendPQExpBuffer(buffer,
711 : " %s IS ",
712 : fmtId(objname));
713 0 : appendStringLiteralConn(buffer, label, conn);
714 0 : appendPQExpBufferStr(buffer, ";\n");
715 : }
716 340 : }
717 :
718 :
719 : /*
720 : * Detect whether the given GUC variable is of GUC_LIST_QUOTE type.
721 : *
722 : * It'd be better if we could inquire this directly from the backend; but even
723 : * if there were a function for that, it could only tell us about variables
724 : * currently known to guc.c, so that it'd be unsafe for extensions to declare
725 : * GUC_LIST_QUOTE variables anyway. Lacking a solution for that, it doesn't
726 : * seem worth the work to do more than have this list, which must be kept in
727 : * sync with the variables actually marked GUC_LIST_QUOTE in guc_tables.c.
728 : */
729 : bool
730 140 : variable_is_guc_list_quote(const char *name)
731 : {
732 270 : if (pg_strcasecmp(name, "local_preload_libraries") == 0 ||
733 250 : pg_strcasecmp(name, "search_path") == 0 ||
734 240 : pg_strcasecmp(name, "session_preload_libraries") == 0 ||
735 240 : pg_strcasecmp(name, "shared_preload_libraries") == 0 ||
736 240 : pg_strcasecmp(name, "temp_tablespaces") == 0 ||
737 120 : pg_strcasecmp(name, "unix_socket_directories") == 0)
738 20 : return true;
739 : else
740 120 : return false;
741 : }
742 :
743 : /*
744 : * SplitGUCList --- parse a string containing identifiers or file names
745 : *
746 : * This is used to split the value of a GUC_LIST_QUOTE GUC variable, without
747 : * presuming whether the elements will be taken as identifiers or file names.
748 : * See comparable code in src/backend/utils/adt/varlena.c.
749 : *
750 : * Inputs:
751 : * rawstring: the input string; must be overwritable! On return, it's
752 : * been modified to contain the separated identifiers.
753 : * separator: the separator punctuation expected between identifiers
754 : * (typically '.' or ','). Whitespace may also appear around
755 : * identifiers.
756 : * Outputs:
757 : * namelist: receives a malloc'd, null-terminated array of pointers to
758 : * identifiers within rawstring. Caller should free this
759 : * even on error return.
760 : *
761 : * Returns true if okay, false if there is a syntax error in the string.
762 : */
763 : bool
764 20 : SplitGUCList(char *rawstring, char separator,
765 : char ***namelist)
766 : {
767 20 : char *nextp = rawstring;
768 20 : bool done = false;
769 : char **nextptr;
770 :
771 : /*
772 : * Since we disallow empty identifiers, this is a conservative
773 : * overestimate of the number of pointers we could need. Allow one for
774 : * list terminator.
775 : */
776 20 : *namelist = nextptr = (char **)
777 20 : pg_malloc((strlen(rawstring) / 2 + 2) * sizeof(char *));
778 20 : *nextptr = NULL;
779 :
780 20 : while (isspace((unsigned char) *nextp))
781 0 : nextp++; /* skip leading whitespace */
782 :
783 20 : if (*nextp == '\0')
784 0 : return true; /* allow empty string */
785 :
786 : /* At the top of the loop, we are at start of a new identifier. */
787 : do
788 : {
789 : char *curname;
790 : char *endp;
791 :
792 50 : if (*nextp == '"')
793 : {
794 : /* Quoted name --- collapse quote-quote pairs */
795 40 : curname = nextp + 1;
796 : for (;;)
797 : {
798 60 : endp = strchr(nextp + 1, '"');
799 50 : if (endp == NULL)
800 0 : return false; /* mismatched quotes */
801 50 : if (endp[1] != '"')
802 40 : break; /* found end of quoted name */
803 : /* Collapse adjacent quotes into one quote, and look again */
804 10 : memmove(endp, endp + 1, strlen(endp));
805 10 : nextp = endp;
806 : }
807 : /* endp now points at the terminating quote */
808 40 : nextp = endp + 1;
809 : }
810 : else
811 : {
812 : /* Unquoted name --- extends to separator or whitespace */
813 10 : curname = nextp;
814 110 : while (*nextp && *nextp != separator &&
815 100 : !isspace((unsigned char) *nextp))
816 100 : nextp++;
817 10 : endp = nextp;
818 10 : if (curname == nextp)
819 0 : return false; /* empty unquoted name not allowed */
820 : }
821 :
822 50 : while (isspace((unsigned char) *nextp))
823 0 : nextp++; /* skip trailing whitespace */
824 :
825 50 : if (*nextp == separator)
826 : {
827 30 : nextp++;
828 60 : while (isspace((unsigned char) *nextp))
829 30 : nextp++; /* skip leading whitespace for next */
830 : /* we expect another name, so done remains false */
831 : }
832 20 : else if (*nextp == '\0')
833 20 : done = true;
834 : else
835 0 : return false; /* invalid syntax */
836 :
837 : /* Now safe to overwrite separator with a null */
838 50 : *endp = '\0';
839 :
840 : /*
841 : * Finished isolating current name --- add it to output array
842 : */
843 50 : *nextptr++ = curname;
844 :
845 : /* Loop back if we didn't reach end of string */
846 50 : } while (!done);
847 :
848 20 : *nextptr = NULL;
849 20 : return true;
850 : }
851 :
852 : /*
853 : * Helper function for dumping "ALTER DATABASE/ROLE SET ..." commands.
854 : *
855 : * Parse the contents of configitem (a "name=value" string), wrap it in
856 : * a complete ALTER command, and append it to buf.
857 : *
858 : * type is DATABASE or ROLE, and name is the name of the database or role.
859 : * If we need an "IN" clause, type2 and name2 similarly define what to put
860 : * there; otherwise they should be NULL.
861 : * conn is used only to determine string-literal quoting conventions.
862 : */
863 : void
864 70 : makeAlterConfigCommand(PGconn *conn, const char *configitem,
865 : const char *type, const char *name,
866 : const char *type2, const char *name2,
867 : PQExpBuffer buf)
868 : {
869 : char *mine;
870 : char *pos;
871 :
872 : /* Parse the configitem. If we can't find an "=", silently do nothing. */
873 70 : mine = pg_strdup(configitem);
874 70 : pos = strchr(mine, '=');
875 70 : if (pos == NULL)
876 : {
877 0 : pg_free(mine);
878 0 : return;
879 : }
880 70 : *pos++ = '\0';
881 :
882 : /* Build the command, with suitable quoting for everything. */
883 70 : appendPQExpBuffer(buf, "ALTER %s %s ", type, fmtId(name));
884 70 : if (type2 != NULL && name2 != NULL)
885 0 : appendPQExpBuffer(buf, "IN %s %s ", type2, fmtId(name2));
886 70 : appendPQExpBuffer(buf, "SET %s TO ", fmtId(mine));
887 :
888 : /*
889 : * Variables that are marked GUC_LIST_QUOTE were already fully quoted by
890 : * flatten_set_variable_args() before they were put into the setconfig
891 : * array. However, because the quoting rules used there aren't exactly
892 : * like SQL's, we have to break the list value apart and then quote the
893 : * elements as string literals. (The elements may be double-quoted as-is,
894 : * but we can't just feed them to the SQL parser; it would do the wrong
895 : * thing with elements that are zero-length or longer than NAMEDATALEN.)
896 : *
897 : * Variables that are not so marked should just be emitted as simple
898 : * string literals. If the variable is not known to
899 : * variable_is_guc_list_quote(), we'll do that; this makes it unsafe to
900 : * use GUC_LIST_QUOTE for extension variables.
901 : */
902 70 : if (variable_is_guc_list_quote(mine))
903 : {
904 : char **namelist;
905 : char **nameptr;
906 :
907 : /* Parse string into list of identifiers */
908 : /* this shouldn't fail really */
909 0 : if (SplitGUCList(pos, ',', &namelist))
910 : {
911 0 : for (nameptr = namelist; *nameptr; nameptr++)
912 : {
913 0 : if (nameptr != namelist)
914 0 : appendPQExpBufferStr(buf, ", ");
915 0 : appendStringLiteralConn(buf, *nameptr, conn);
916 : }
917 : }
918 0 : pg_free(namelist);
919 : }
920 : else
921 70 : appendStringLiteralConn(buf, pos, conn);
922 :
923 70 : appendPQExpBufferStr(buf, ";\n");
924 :
925 70 : pg_free(mine);
926 : }
927 :
928 : /*
929 : * create_or_open_dir
930 : *
931 : * This will create a new directory with the given dirname. If there is
932 : * already an empty directory with that name, then use it.
933 : */
934 : void
935 20 : create_or_open_dir(const char *dirname)
936 : {
937 : int ret;
938 :
939 20 : switch ((ret = pg_check_dir(dirname)))
940 : {
941 0 : case -1:
942 : /* opendir failed but not with ENOENT */
943 0 : pg_fatal("could not open directory \"%s\": %m", dirname);
944 : break;
945 20 : case 0:
946 : /* directory does not exist */
947 20 : if (mkdir(dirname, pg_dir_create_mode) < 0)
948 0 : pg_fatal("could not create directory \"%s\": %m", dirname);
949 20 : break;
950 0 : case 1:
951 : /* exists and is empty, fix perms */
952 0 : if (chmod(dirname, pg_dir_create_mode) != 0)
953 0 : pg_fatal("could not change permissions of directory \"%s\": %m",
954 : dirname);
955 0 : break;
956 0 : default:
957 : /* exists and is not empty */
958 0 : pg_fatal("directory \"%s\" is not empty", dirname);
959 : }
960 20 : }
961 :
962 : /*
963 : * Generates a valid restrict key (i.e., an alphanumeric string) for use with
964 : * psql's \restrict and \unrestrict meta-commands. For safety, the value is
965 : * chosen at random.
966 : */
967 : char *
968 368 : generate_restrict_key(void)
969 : {
970 : uint8 buf[64];
971 368 : char *ret = palloc(sizeof(buf));
972 :
973 368 : if (!pg_strong_random(buf, sizeof(buf)))
974 0 : return NULL;
975 :
976 23552 : for (int i = 0; i < sizeof(buf) - 1; i++)
977 : {
978 23184 : uint8 idx = buf[i] % strlen(restrict_chars);
979 :
980 23184 : ret[i] = restrict_chars[idx];
981 : }
982 368 : ret[sizeof(buf) - 1] = '\0';
983 :
984 368 : return ret;
985 : }
986 :
987 : /*
988 : * Checks that a given restrict key (intended for use with psql's \restrict and
989 : * \unrestrict meta-commands) contains only alphanumeric characters.
990 : */
991 : bool
992 432 : valid_restrict_key(const char *restrict_key)
993 : {
994 432 : return restrict_key != NULL &&
995 864 : restrict_key[0] != '\0' &&
996 432 : strspn(restrict_key, restrict_chars) == strlen(restrict_key);
997 : }
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