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) 1996-2024, 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 "dumputils.h"
20 : #include "fe_utils/string_utils.h"
21 :
22 :
23 : static bool parseAclItem(const char *item, const char *type,
24 : const char *name, const char *subname, int remoteVersion,
25 : PQExpBuffer grantee, PQExpBuffer grantor,
26 : PQExpBuffer privs, PQExpBuffer privswgo);
27 : static char *dequoteAclUserName(PQExpBuffer output, char *input);
28 : static void AddAcl(PQExpBuffer aclbuf, const char *keyword,
29 : const char *subname);
30 :
31 :
32 : /*
33 : * Build GRANT/REVOKE command(s) for an object.
34 : *
35 : * name: the object name, in the form to use in the commands (already quoted)
36 : * subname: the sub-object name, if any (already quoted); NULL if none
37 : * nspname: the namespace the object is in (NULL if none); not pre-quoted
38 : * type: the object type (as seen in GRANT command: must be one of
39 : * TABLE, SEQUENCE, FUNCTION, PROCEDURE, LANGUAGE, SCHEMA, DATABASE, TABLESPACE,
40 : * FOREIGN DATA WRAPPER, SERVER, PARAMETER or LARGE OBJECT)
41 : * acls: the ACL string fetched from the database
42 : * baseacls: the initial ACL string for this object
43 : * owner: username of object owner (will be passed through fmtId); can be
44 : * NULL or empty string to indicate "no owner known"
45 : * prefix: string to prefix to each generated command; typically empty
46 : * remoteVersion: version of database
47 : *
48 : * Returns true if okay, false if could not parse the acl string.
49 : * The resulting commands (if any) are appended to the contents of 'sql'.
50 : *
51 : * baseacls is typically the result of acldefault() for the object's type
52 : * and owner. However, if there is a pg_init_privs entry for the object,
53 : * it should instead be the initprivs ACLs. When acls is itself a
54 : * pg_init_privs entry, baseacls is what to dump that relative to; then
55 : * it can be either an acldefault() value or an empty ACL "{}".
56 : *
57 : * Note: when processing a default ACL, prefix is "ALTER DEFAULT PRIVILEGES "
58 : * or something similar, and name is an empty string.
59 : *
60 : * Note: beware of passing a fmtId() result directly as 'name' or 'subname',
61 : * since this routine uses fmtId() internally.
62 : */
63 : bool
64 45498 : buildACLCommands(const char *name, const char *subname, const char *nspname,
65 : const char *type, const char *acls, const char *baseacls,
66 : const char *owner, const char *prefix, int remoteVersion,
67 : PQExpBuffer sql)
68 : {
69 45498 : bool ok = true;
70 45498 : char **aclitems = NULL;
71 45498 : char **baseitems = NULL;
72 45498 : char **grantitems = NULL;
73 45498 : char **revokeitems = NULL;
74 45498 : int naclitems = 0;
75 45498 : int nbaseitems = 0;
76 45498 : int ngrantitems = 0;
77 45498 : int nrevokeitems = 0;
78 : int i;
79 : PQExpBuffer grantee,
80 : grantor,
81 : privs,
82 : privswgo;
83 : PQExpBuffer firstsql,
84 : secondsql;
85 :
86 : /*
87 : * If the acl was NULL (initial default state), we need do nothing. Note
88 : * that this is distinguishable from all-privileges-revoked, which will
89 : * look like an empty array ("{}").
90 : */
91 45498 : if (acls == NULL || *acls == '\0')
92 178 : return true; /* object has default permissions */
93 :
94 : /* treat empty-string owner same as NULL */
95 45320 : if (owner && *owner == '\0')
96 0 : owner = NULL;
97 :
98 : /* Parse the acls array */
99 45320 : if (!parsePGArray(acls, &aclitems, &naclitems))
100 : {
101 0 : free(aclitems);
102 0 : return false;
103 : }
104 :
105 : /* Parse the baseacls too */
106 45320 : if (!parsePGArray(baseacls, &baseitems, &nbaseitems))
107 : {
108 0 : free(aclitems);
109 0 : free(baseitems);
110 0 : return false;
111 : }
112 :
113 : /*
114 : * Compare the actual ACL with the base ACL, extracting the privileges
115 : * that need to be granted (i.e., are in the actual ACL but not the base
116 : * ACL) and the ones that need to be revoked (the reverse). We use plain
117 : * string comparisons to check for matches. In principle that could be
118 : * fooled by extraneous issues such as whitespace, but since all these
119 : * strings are the work of aclitemout(), it should be OK in practice.
120 : * Besides, a false mismatch will just cause the output to be a little
121 : * more verbose than it really needed to be.
122 : */
123 45320 : grantitems = (char **) pg_malloc(naclitems * sizeof(char *));
124 125994 : for (i = 0; i < naclitems; i++)
125 : {
126 80674 : bool found = false;
127 :
128 116998 : for (int j = 0; j < nbaseitems; j++)
129 : {
130 113510 : if (strcmp(aclitems[i], baseitems[j]) == 0)
131 : {
132 77186 : found = true;
133 77186 : break;
134 : }
135 : }
136 80674 : if (!found)
137 3488 : grantitems[ngrantitems++] = aclitems[i];
138 : }
139 45320 : revokeitems = (char **) pg_malloc(nbaseitems * sizeof(char *));
140 123196 : for (i = 0; i < nbaseitems; i++)
141 : {
142 77876 : bool found = false;
143 :
144 112928 : for (int j = 0; j < naclitems; j++)
145 : {
146 112238 : if (strcmp(baseitems[i], aclitems[j]) == 0)
147 : {
148 77186 : found = true;
149 77186 : break;
150 : }
151 : }
152 77876 : if (!found)
153 690 : revokeitems[nrevokeitems++] = baseitems[i];
154 : }
155 :
156 : /* Prepare working buffers */
157 45320 : grantee = createPQExpBuffer();
158 45320 : grantor = createPQExpBuffer();
159 45320 : privs = createPQExpBuffer();
160 45320 : privswgo = createPQExpBuffer();
161 :
162 : /*
163 : * At the end, these two will be pasted together to form the result.
164 : */
165 45320 : firstsql = createPQExpBuffer();
166 45320 : secondsql = createPQExpBuffer();
167 :
168 : /*
169 : * Build REVOKE statements for ACLs listed in revokeitems[].
170 : */
171 46010 : for (i = 0; i < nrevokeitems; i++)
172 : {
173 690 : if (!parseAclItem(revokeitems[i],
174 : type, name, subname, remoteVersion,
175 : grantee, grantor, privs, NULL))
176 : {
177 0 : ok = false;
178 0 : break;
179 : }
180 :
181 690 : if (privs->len > 0)
182 : {
183 690 : appendPQExpBuffer(firstsql, "%sREVOKE %s ON %s ",
184 : prefix, privs->data, type);
185 690 : if (nspname && *nspname)
186 406 : appendPQExpBuffer(firstsql, "%s.", fmtId(nspname));
187 690 : if (name && *name)
188 566 : appendPQExpBuffer(firstsql, "%s ", name);
189 690 : appendPQExpBufferStr(firstsql, "FROM ");
190 690 : if (grantee->len == 0)
191 356 : appendPQExpBufferStr(firstsql, "PUBLIC;\n");
192 : else
193 334 : appendPQExpBuffer(firstsql, "%s;\n",
194 334 : fmtId(grantee->data));
195 : }
196 : }
197 :
198 : /*
199 : * At this point we have issued REVOKE statements for all initial and
200 : * default privileges that are no longer present on the object, so we are
201 : * almost ready to GRANT the privileges listed in grantitems[].
202 : *
203 : * We still need some hacking though to cover the case where new default
204 : * public privileges are added in new versions: the REVOKE ALL will revoke
205 : * them, leading to behavior different from what the old version had,
206 : * which is generally not what's wanted. So add back default privs if the
207 : * source database is too old to have had that particular priv. (As of
208 : * right now, no such cases exist in supported versions.)
209 : */
210 :
211 : /*
212 : * Scan individual ACL items to be granted.
213 : *
214 : * The order in which privileges appear in the ACL string (the order they
215 : * have been GRANT'd in, which the backend maintains) must be preserved to
216 : * ensure that GRANTs WITH GRANT OPTION and subsequent GRANTs based on
217 : * those are dumped in the correct order. However, some old server
218 : * versions will show grants to PUBLIC before the owner's own grants; for
219 : * consistency's sake, force the owner's grants to be output first.
220 : */
221 48808 : for (i = 0; i < ngrantitems; i++)
222 : {
223 3488 : if (parseAclItem(grantitems[i], type, name, subname, remoteVersion,
224 : grantee, grantor, privs, privswgo))
225 : {
226 : /*
227 : * If the grantor isn't the owner, we'll need to use SET SESSION
228 : * AUTHORIZATION to become the grantor. Issue the SET/RESET only
229 : * if there's something useful to do.
230 : */
231 3488 : if (privs->len > 0 || privswgo->len > 0)
232 : {
233 : PQExpBuffer thissql;
234 :
235 : /* Set owner as grantor if that's not explicit in the ACL */
236 3488 : if (grantor->len == 0 && owner)
237 0 : printfPQExpBuffer(grantor, "%s", owner);
238 :
239 : /* Make sure owner's own grants are output before others */
240 3488 : if (owner &&
241 3488 : strcmp(grantee->data, owner) == 0 &&
242 242 : strcmp(grantor->data, owner) == 0)
243 242 : thissql = firstsql;
244 : else
245 3246 : thissql = secondsql;
246 :
247 3488 : if (grantor->len > 0
248 3488 : && (!owner || strcmp(owner, grantor->data) != 0))
249 0 : appendPQExpBuffer(thissql, "SET SESSION AUTHORIZATION %s;\n",
250 0 : fmtId(grantor->data));
251 :
252 3488 : if (privs->len > 0)
253 : {
254 3484 : appendPQExpBuffer(thissql, "%sGRANT %s ON %s ",
255 : prefix, privs->data, type);
256 3484 : if (nspname && *nspname)
257 2998 : appendPQExpBuffer(thissql, "%s.", fmtId(nspname));
258 3484 : if (name && *name)
259 3294 : appendPQExpBuffer(thissql, "%s ", name);
260 3484 : appendPQExpBufferStr(thissql, "TO ");
261 3484 : if (grantee->len == 0)
262 2018 : appendPQExpBufferStr(thissql, "PUBLIC;\n");
263 : else
264 1466 : appendPQExpBuffer(thissql, "%s;\n", fmtId(grantee->data));
265 : }
266 3488 : if (privswgo->len > 0)
267 : {
268 40 : appendPQExpBuffer(thissql, "%sGRANT %s ON %s ",
269 : prefix, privswgo->data, type);
270 40 : if (nspname && *nspname)
271 38 : appendPQExpBuffer(thissql, "%s.", fmtId(nspname));
272 40 : if (name && *name)
273 40 : appendPQExpBuffer(thissql, "%s ", name);
274 40 : appendPQExpBufferStr(thissql, "TO ");
275 40 : if (grantee->len == 0)
276 0 : appendPQExpBufferStr(thissql, "PUBLIC");
277 : else
278 40 : appendPQExpBufferStr(thissql, fmtId(grantee->data));
279 40 : appendPQExpBufferStr(thissql, " WITH GRANT OPTION;\n");
280 : }
281 :
282 3488 : if (grantor->len > 0
283 3488 : && (!owner || strcmp(owner, grantor->data) != 0))
284 0 : appendPQExpBufferStr(thissql, "RESET SESSION AUTHORIZATION;\n");
285 : }
286 : }
287 : else
288 : {
289 : /* parseAclItem failed, give up */
290 0 : ok = false;
291 0 : break;
292 : }
293 : }
294 :
295 45320 : destroyPQExpBuffer(grantee);
296 45320 : destroyPQExpBuffer(grantor);
297 45320 : destroyPQExpBuffer(privs);
298 45320 : destroyPQExpBuffer(privswgo);
299 :
300 45320 : appendPQExpBuffer(sql, "%s%s", firstsql->data, secondsql->data);
301 45320 : destroyPQExpBuffer(firstsql);
302 45320 : destroyPQExpBuffer(secondsql);
303 :
304 45320 : free(aclitems);
305 45320 : free(baseitems);
306 45320 : free(grantitems);
307 45320 : free(revokeitems);
308 :
309 45320 : return ok;
310 : }
311 :
312 : /*
313 : * Build ALTER DEFAULT PRIVILEGES command(s) for a single pg_default_acl entry.
314 : *
315 : * type: the object type (TABLES, FUNCTIONS, etc)
316 : * nspname: schema name, or NULL for global default privileges
317 : * acls: the ACL string fetched from the database
318 : * acldefault: the appropriate default ACL for the object type and owner
319 : * owner: username of privileges owner (will be passed through fmtId)
320 : * remoteVersion: version of database
321 : *
322 : * Returns true if okay, false if could not parse the acl string.
323 : * The resulting commands (if any) are appended to the contents of 'sql'.
324 : */
325 : bool
326 252 : buildDefaultACLCommands(const char *type, const char *nspname,
327 : const char *acls, const char *acldefault,
328 : const char *owner,
329 : int remoteVersion,
330 : PQExpBuffer sql)
331 : {
332 : PQExpBuffer prefix;
333 :
334 252 : prefix = createPQExpBuffer();
335 :
336 : /*
337 : * We incorporate the target role directly into the command, rather than
338 : * playing around with SET ROLE or anything like that. This is so that a
339 : * permissions error leads to nothing happening, rather than changing
340 : * default privileges for the wrong user.
341 : */
342 252 : appendPQExpBuffer(prefix, "ALTER DEFAULT PRIVILEGES FOR ROLE %s ",
343 : fmtId(owner));
344 252 : if (nspname)
345 128 : appendPQExpBuffer(prefix, "IN SCHEMA %s ", fmtId(nspname));
346 :
347 : /*
348 : * There's no such thing as initprivs for a default ACL, so the base ACL
349 : * is always just the object-type-specific default.
350 : */
351 252 : if (!buildACLCommands("", NULL, NULL, type,
352 : acls, acldefault, owner,
353 252 : prefix->data, remoteVersion, sql))
354 : {
355 0 : destroyPQExpBuffer(prefix);
356 0 : return false;
357 : }
358 :
359 252 : destroyPQExpBuffer(prefix);
360 :
361 252 : return true;
362 : }
363 :
364 : /*
365 : * This will parse an aclitem string, having the general form
366 : * username=privilegecodes/grantor
367 : *
368 : * Returns true on success, false on parse error. On success, the components
369 : * of the string are returned in the PQExpBuffer parameters.
370 : *
371 : * The returned grantee string will be the dequoted username, or an empty
372 : * string in the case of a grant to PUBLIC. The returned grantor is the
373 : * dequoted grantor name. Privilege characters are translated to GRANT/REVOKE
374 : * comma-separated privileges lists. If "privswgo" is non-NULL, the result is
375 : * separate lists for privileges with grant option ("privswgo") and without
376 : * ("privs"). Otherwise, "privs" bears every relevant privilege, ignoring the
377 : * grant option distinction.
378 : *
379 : * Note: for cross-version compatibility, it's important to use ALL to
380 : * represent the privilege sets whenever appropriate.
381 : */
382 : static bool
383 4178 : parseAclItem(const char *item, const char *type,
384 : const char *name, const char *subname, int remoteVersion,
385 : PQExpBuffer grantee, PQExpBuffer grantor,
386 : PQExpBuffer privs, PQExpBuffer privswgo)
387 : {
388 : char *buf;
389 4178 : bool all_with_go = true;
390 4178 : bool all_without_go = true;
391 : char *eqpos;
392 : char *slpos;
393 : char *pos;
394 :
395 4178 : buf = pg_strdup(item);
396 :
397 : /* user or group name is string up to = */
398 4178 : eqpos = dequoteAclUserName(grantee, buf);
399 4178 : if (*eqpos != '=')
400 : {
401 0 : pg_free(buf);
402 0 : return false;
403 : }
404 :
405 : /* grantor should appear after / */
406 4178 : slpos = strchr(eqpos + 1, '/');
407 4178 : if (slpos)
408 : {
409 4178 : *slpos++ = '\0';
410 4178 : slpos = dequoteAclUserName(grantor, slpos);
411 4178 : if (*slpos != '\0')
412 : {
413 0 : pg_free(buf);
414 0 : return false;
415 : }
416 : }
417 : else
418 : {
419 0 : pg_free(buf);
420 0 : return false;
421 : }
422 :
423 : /* privilege codes */
424 : #define CONVERT_PRIV(code, keywd) \
425 : do { \
426 : if ((pos = strchr(eqpos + 1, code))) \
427 : { \
428 : if (*(pos + 1) == '*' && privswgo != NULL) \
429 : { \
430 : AddAcl(privswgo, keywd, subname); \
431 : all_without_go = false; \
432 : } \
433 : else \
434 : { \
435 : AddAcl(privs, keywd, subname); \
436 : all_with_go = false; \
437 : } \
438 : } \
439 : else \
440 : all_with_go = all_without_go = false; \
441 : } while (0)
442 :
443 4178 : resetPQExpBuffer(privs);
444 4178 : resetPQExpBuffer(privswgo);
445 :
446 4178 : if (strcmp(type, "TABLE") == 0 || strcmp(type, "SEQUENCE") == 0 ||
447 1330 : strcmp(type, "TABLES") == 0 || strcmp(type, "SEQUENCES") == 0)
448 : {
449 3036 : CONVERT_PRIV('r', "SELECT");
450 :
451 3036 : if (strcmp(type, "SEQUENCE") == 0 ||
452 2926 : strcmp(type, "SEQUENCES") == 0)
453 : /* sequence only */
454 110 : CONVERT_PRIV('U', "USAGE");
455 : else
456 : {
457 : /* table only */
458 2926 : CONVERT_PRIV('a', "INSERT");
459 2926 : CONVERT_PRIV('x', "REFERENCES");
460 : /* rest are not applicable to columns */
461 2926 : if (subname == NULL)
462 : {
463 766 : CONVERT_PRIV('d', "DELETE");
464 766 : CONVERT_PRIV('t', "TRIGGER");
465 766 : CONVERT_PRIV('D', "TRUNCATE");
466 766 : CONVERT_PRIV('m', "MAINTAIN");
467 : }
468 : }
469 :
470 : /* UPDATE */
471 3036 : CONVERT_PRIV('w', "UPDATE");
472 : }
473 1142 : else if (strcmp(type, "FUNCTION") == 0 ||
474 842 : strcmp(type, "FUNCTIONS") == 0)
475 426 : CONVERT_PRIV('X', "EXECUTE");
476 716 : else if (strcmp(type, "PROCEDURE") == 0 ||
477 716 : strcmp(type, "PROCEDURES") == 0)
478 0 : CONVERT_PRIV('X', "EXECUTE");
479 716 : else if (strcmp(type, "LANGUAGE") == 0)
480 76 : CONVERT_PRIV('U', "USAGE");
481 640 : else if (strcmp(type, "SCHEMA") == 0 ||
482 482 : strcmp(type, "SCHEMAS") == 0)
483 : {
484 158 : CONVERT_PRIV('C', "CREATE");
485 158 : CONVERT_PRIV('U', "USAGE");
486 : }
487 482 : else if (strcmp(type, "DATABASE") == 0)
488 : {
489 28 : CONVERT_PRIV('C', "CREATE");
490 28 : CONVERT_PRIV('c', "CONNECT");
491 28 : CONVERT_PRIV('T', "TEMPORARY");
492 : }
493 454 : else if (strcmp(type, "TABLESPACE") == 0)
494 0 : CONVERT_PRIV('C', "CREATE");
495 454 : else if (strcmp(type, "TYPE") == 0 ||
496 196 : strcmp(type, "TYPES") == 0)
497 258 : CONVERT_PRIV('U', "USAGE");
498 196 : else if (strcmp(type, "FOREIGN DATA WRAPPER") == 0)
499 62 : CONVERT_PRIV('U', "USAGE");
500 134 : else if (strcmp(type, "FOREIGN SERVER") == 0)
501 62 : CONVERT_PRIV('U', "USAGE");
502 72 : else if (strcmp(type, "FOREIGN TABLE") == 0)
503 0 : CONVERT_PRIV('r', "SELECT");
504 72 : else if (strcmp(type, "PARAMETER") == 0)
505 : {
506 6 : CONVERT_PRIV('s', "SET");
507 6 : CONVERT_PRIV('A', "ALTER SYSTEM");
508 : }
509 66 : else if (strcmp(type, "LARGE OBJECT") == 0)
510 : {
511 66 : CONVERT_PRIV('r', "SELECT");
512 66 : CONVERT_PRIV('w', "UPDATE");
513 : }
514 : else
515 0 : abort();
516 :
517 : #undef CONVERT_PRIV
518 :
519 4178 : if (all_with_go)
520 : {
521 4 : resetPQExpBuffer(privs);
522 4 : printfPQExpBuffer(privswgo, "ALL");
523 4 : if (subname)
524 0 : appendPQExpBuffer(privswgo, "(%s)", subname);
525 : }
526 4174 : else if (all_without_go)
527 : {
528 1128 : resetPQExpBuffer(privswgo);
529 1128 : printfPQExpBuffer(privs, "ALL");
530 1128 : if (subname)
531 0 : appendPQExpBuffer(privs, "(%s)", subname);
532 : }
533 :
534 4178 : pg_free(buf);
535 :
536 4178 : return true;
537 : }
538 :
539 : /*
540 : * Transfer the role name at *input into the output buffer, adding
541 : * quoting according to the same rules as putid() in backend's acl.c.
542 : */
543 : void
544 906 : quoteAclUserName(PQExpBuffer output, const char *input)
545 : {
546 : const char *src;
547 906 : bool safe = true;
548 :
549 15444 : for (src = input; *src; src++)
550 : {
551 : /* This test had better match what putid() does */
552 14826 : if (!isalnum((unsigned char) *src) && *src != '_')
553 : {
554 288 : safe = false;
555 288 : break;
556 : }
557 : }
558 906 : if (!safe)
559 288 : appendPQExpBufferChar(output, '"');
560 18036 : for (src = input; *src; src++)
561 : {
562 : /* A double quote character in a username is encoded as "" */
563 17130 : if (*src == '"')
564 288 : appendPQExpBufferChar(output, '"');
565 17130 : appendPQExpBufferChar(output, *src);
566 : }
567 906 : if (!safe)
568 288 : appendPQExpBufferChar(output, '"');
569 906 : }
570 :
571 : /*
572 : * Transfer a user or group name starting at *input into the output buffer,
573 : * dequoting if needed. Returns a pointer to just past the input name.
574 : * The name is taken to end at an unquoted '=' or end of string.
575 : * Note: unlike quoteAclUserName(), this first clears the output buffer.
576 : */
577 : static char *
578 8356 : dequoteAclUserName(PQExpBuffer output, char *input)
579 : {
580 8356 : resetPQExpBuffer(output);
581 :
582 80554 : while (*input && *input != '=')
583 : {
584 : /*
585 : * If user name isn't quoted, then just add it to the output buffer
586 : */
587 72198 : if (*input != '"')
588 72010 : appendPQExpBufferChar(output, *input++);
589 : else
590 : {
591 : /* Otherwise, it's a quoted username */
592 188 : input++;
593 : /* Loop until we come across an unescaped quote */
594 4512 : while (!(*input == '"' && *(input + 1) != '"'))
595 : {
596 4324 : if (*input == '\0')
597 0 : return input; /* really a syntax error... */
598 :
599 : /*
600 : * Quoting convention is to escape " as "". Keep this code in
601 : * sync with putid() in backend's acl.c.
602 : */
603 4324 : if (*input == '"' && *(input + 1) == '"')
604 188 : input++;
605 4324 : appendPQExpBufferChar(output, *input++);
606 : }
607 188 : input++;
608 : }
609 : }
610 8356 : return input;
611 : }
612 :
613 : /*
614 : * Append a privilege keyword to a keyword list, inserting comma if needed.
615 : */
616 : static void
617 5408 : AddAcl(PQExpBuffer aclbuf, const char *keyword, const char *subname)
618 : {
619 5408 : if (aclbuf->len > 0)
620 1194 : appendPQExpBufferChar(aclbuf, ',');
621 5408 : appendPQExpBufferStr(aclbuf, keyword);
622 5408 : if (subname)
623 2160 : appendPQExpBuffer(aclbuf, "(%s)", subname);
624 5408 : }
625 :
626 :
627 : /*
628 : * buildShSecLabelQuery
629 : *
630 : * Build a query to retrieve security labels for a shared object.
631 : * The object is identified by its OID plus the name of the catalog
632 : * it can be found in (e.g., "pg_database" for database names).
633 : * The query is appended to "sql". (We don't execute it here so as to
634 : * keep this file free of assumptions about how to deal with SQL errors.)
635 : */
636 : void
637 262 : buildShSecLabelQuery(const char *catalog_name, Oid objectId,
638 : PQExpBuffer sql)
639 : {
640 262 : appendPQExpBuffer(sql,
641 : "SELECT provider, label FROM pg_catalog.pg_shseclabel "
642 : "WHERE classoid = 'pg_catalog.%s'::pg_catalog.regclass "
643 : "AND objoid = '%u'", catalog_name, objectId);
644 262 : }
645 :
646 : /*
647 : * emitShSecLabels
648 : *
649 : * Construct SECURITY LABEL commands using the data retrieved by the query
650 : * generated by buildShSecLabelQuery, and append them to "buffer".
651 : * Here, the target object is identified by its type name (e.g. "DATABASE")
652 : * and its name (not pre-quoted).
653 : */
654 : void
655 262 : emitShSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
656 : const char *objtype, const char *objname)
657 : {
658 : int i;
659 :
660 262 : for (i = 0; i < PQntuples(res); i++)
661 : {
662 0 : char *provider = PQgetvalue(res, i, 0);
663 0 : char *label = PQgetvalue(res, i, 1);
664 :
665 : /* must use fmtId result before calling it again */
666 0 : appendPQExpBuffer(buffer,
667 : "SECURITY LABEL FOR %s ON %s",
668 : fmtId(provider), objtype);
669 0 : appendPQExpBuffer(buffer,
670 : " %s IS ",
671 : fmtId(objname));
672 0 : appendStringLiteralConn(buffer, label, conn);
673 0 : appendPQExpBufferStr(buffer, ";\n");
674 : }
675 262 : }
676 :
677 :
678 : /*
679 : * Detect whether the given GUC variable is of GUC_LIST_QUOTE type.
680 : *
681 : * It'd be better if we could inquire this directly from the backend; but even
682 : * if there were a function for that, it could only tell us about variables
683 : * currently known to guc.c, so that it'd be unsafe for extensions to declare
684 : * GUC_LIST_QUOTE variables anyway. Lacking a solution for that, it doesn't
685 : * seem worth the work to do more than have this list, which must be kept in
686 : * sync with the variables actually marked GUC_LIST_QUOTE in guc_tables.c.
687 : */
688 : bool
689 130 : variable_is_guc_list_quote(const char *name)
690 : {
691 250 : if (pg_strcasecmp(name, "local_preload_libraries") == 0 ||
692 230 : pg_strcasecmp(name, "search_path") == 0 ||
693 220 : pg_strcasecmp(name, "session_preload_libraries") == 0 ||
694 220 : pg_strcasecmp(name, "shared_preload_libraries") == 0 ||
695 220 : pg_strcasecmp(name, "temp_tablespaces") == 0 ||
696 110 : pg_strcasecmp(name, "unix_socket_directories") == 0)
697 20 : return true;
698 : else
699 110 : return false;
700 : }
701 :
702 : /*
703 : * SplitGUCList --- parse a string containing identifiers or file names
704 : *
705 : * This is used to split the value of a GUC_LIST_QUOTE GUC variable, without
706 : * presuming whether the elements will be taken as identifiers or file names.
707 : * See comparable code in src/backend/utils/adt/varlena.c.
708 : *
709 : * Inputs:
710 : * rawstring: the input string; must be overwritable! On return, it's
711 : * been modified to contain the separated identifiers.
712 : * separator: the separator punctuation expected between identifiers
713 : * (typically '.' or ','). Whitespace may also appear around
714 : * identifiers.
715 : * Outputs:
716 : * namelist: receives a malloc'd, null-terminated array of pointers to
717 : * identifiers within rawstring. Caller should free this
718 : * even on error return.
719 : *
720 : * Returns true if okay, false if there is a syntax error in the string.
721 : */
722 : bool
723 20 : SplitGUCList(char *rawstring, char separator,
724 : char ***namelist)
725 : {
726 20 : char *nextp = rawstring;
727 20 : bool done = false;
728 : char **nextptr;
729 :
730 : /*
731 : * Since we disallow empty identifiers, this is a conservative
732 : * overestimate of the number of pointers we could need. Allow one for
733 : * list terminator.
734 : */
735 20 : *namelist = nextptr = (char **)
736 20 : pg_malloc((strlen(rawstring) / 2 + 2) * sizeof(char *));
737 20 : *nextptr = NULL;
738 :
739 20 : while (isspace((unsigned char) *nextp))
740 0 : nextp++; /* skip leading whitespace */
741 :
742 20 : if (*nextp == '\0')
743 0 : return true; /* allow empty string */
744 :
745 : /* At the top of the loop, we are at start of a new identifier. */
746 : do
747 : {
748 : char *curname;
749 : char *endp;
750 :
751 50 : if (*nextp == '"')
752 : {
753 : /* Quoted name --- collapse quote-quote pairs */
754 40 : curname = nextp + 1;
755 : for (;;)
756 : {
757 60 : endp = strchr(nextp + 1, '"');
758 50 : if (endp == NULL)
759 0 : return false; /* mismatched quotes */
760 50 : if (endp[1] != '"')
761 40 : break; /* found end of quoted name */
762 : /* Collapse adjacent quotes into one quote, and look again */
763 10 : memmove(endp, endp + 1, strlen(endp));
764 10 : nextp = endp;
765 : }
766 : /* endp now points at the terminating quote */
767 40 : nextp = endp + 1;
768 : }
769 : else
770 : {
771 : /* Unquoted name --- extends to separator or whitespace */
772 10 : curname = nextp;
773 110 : while (*nextp && *nextp != separator &&
774 100 : !isspace((unsigned char) *nextp))
775 100 : nextp++;
776 10 : endp = nextp;
777 10 : if (curname == nextp)
778 0 : return false; /* empty unquoted name not allowed */
779 : }
780 :
781 50 : while (isspace((unsigned char) *nextp))
782 0 : nextp++; /* skip trailing whitespace */
783 :
784 50 : if (*nextp == separator)
785 : {
786 30 : nextp++;
787 60 : while (isspace((unsigned char) *nextp))
788 30 : nextp++; /* skip leading whitespace for next */
789 : /* we expect another name, so done remains false */
790 : }
791 20 : else if (*nextp == '\0')
792 20 : done = true;
793 : else
794 0 : return false; /* invalid syntax */
795 :
796 : /* Now safe to overwrite separator with a null */
797 50 : *endp = '\0';
798 :
799 : /*
800 : * Finished isolating current name --- add it to output array
801 : */
802 50 : *nextptr++ = curname;
803 :
804 : /* Loop back if we didn't reach end of string */
805 50 : } while (!done);
806 :
807 20 : *nextptr = NULL;
808 20 : return true;
809 : }
810 :
811 : /*
812 : * Helper function for dumping "ALTER DATABASE/ROLE SET ..." commands.
813 : *
814 : * Parse the contents of configitem (a "name=value" string), wrap it in
815 : * a complete ALTER command, and append it to buf.
816 : *
817 : * type is DATABASE or ROLE, and name is the name of the database or role.
818 : * If we need an "IN" clause, type2 and name2 similarly define what to put
819 : * there; otherwise they should be NULL.
820 : * conn is used only to determine string-literal quoting conventions.
821 : */
822 : void
823 60 : makeAlterConfigCommand(PGconn *conn, const char *configitem,
824 : const char *type, const char *name,
825 : const char *type2, const char *name2,
826 : PQExpBuffer buf)
827 : {
828 : char *mine;
829 : char *pos;
830 :
831 : /* Parse the configitem. If we can't find an "=", silently do nothing. */
832 60 : mine = pg_strdup(configitem);
833 60 : pos = strchr(mine, '=');
834 60 : if (pos == NULL)
835 : {
836 0 : pg_free(mine);
837 0 : return;
838 : }
839 60 : *pos++ = '\0';
840 :
841 : /* Build the command, with suitable quoting for everything. */
842 60 : appendPQExpBuffer(buf, "ALTER %s %s ", type, fmtId(name));
843 60 : if (type2 != NULL && name2 != NULL)
844 0 : appendPQExpBuffer(buf, "IN %s %s ", type2, fmtId(name2));
845 60 : appendPQExpBuffer(buf, "SET %s TO ", fmtId(mine));
846 :
847 : /*
848 : * Variables that are marked GUC_LIST_QUOTE were already fully quoted by
849 : * flatten_set_variable_args() before they were put into the setconfig
850 : * array. However, because the quoting rules used there aren't exactly
851 : * like SQL's, we have to break the list value apart and then quote the
852 : * elements as string literals. (The elements may be double-quoted as-is,
853 : * but we can't just feed them to the SQL parser; it would do the wrong
854 : * thing with elements that are zero-length or longer than NAMEDATALEN.)
855 : *
856 : * Variables that are not so marked should just be emitted as simple
857 : * string literals. If the variable is not known to
858 : * variable_is_guc_list_quote(), we'll do that; this makes it unsafe to
859 : * use GUC_LIST_QUOTE for extension variables.
860 : */
861 60 : if (variable_is_guc_list_quote(mine))
862 : {
863 : char **namelist;
864 : char **nameptr;
865 :
866 : /* Parse string into list of identifiers */
867 : /* this shouldn't fail really */
868 0 : if (SplitGUCList(pos, ',', &namelist))
869 : {
870 0 : for (nameptr = namelist; *nameptr; nameptr++)
871 : {
872 0 : if (nameptr != namelist)
873 0 : appendPQExpBufferStr(buf, ", ");
874 0 : appendStringLiteralConn(buf, *nameptr, conn);
875 : }
876 : }
877 0 : pg_free(namelist);
878 : }
879 : else
880 60 : appendStringLiteralConn(buf, pos, conn);
881 :
882 60 : appendPQExpBufferStr(buf, ";\n");
883 :
884 60 : pg_free(mine);
885 : }
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