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) 1996-2026, 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 0 : sanitize_line(const char *str, bool want_hyphen)
53 : {
54 0 : char *result;
55 0 : char *s;
56 :
57 0 : if (!str)
58 0 : return pg_strdup(want_hyphen ? "-" : "");
59 :
60 0 : result = pg_strdup(str);
61 :
62 0 : for (s = result; *s != '\0'; s++)
63 : {
64 0 : if (*s == '\n' || *s == '\r')
65 0 : *s = ' ';
66 0 : }
67 :
68 0 : return result;
69 0 : }
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 0 : 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 0 : bool ok = true;
110 0 : char **aclitems = NULL;
111 0 : char **baseitems = NULL;
112 0 : char **grantitems = NULL;
113 0 : char **revokeitems = NULL;
114 0 : int naclitems = 0;
115 0 : int nbaseitems = 0;
116 0 : int ngrantitems = 0;
117 0 : int nrevokeitems = 0;
118 0 : int i;
119 0 : PQExpBuffer grantee,
120 : grantor,
121 : privs,
122 : privswgo;
123 0 : 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 0 : if (acls == NULL || *acls == '\0')
132 0 : return true; /* object has default permissions */
133 :
134 : /* treat empty-string owner same as NULL */
135 0 : if (owner && *owner == '\0')
136 0 : owner = NULL;
137 :
138 : /* Parse the acls array */
139 0 : if (!parsePGArray(acls, &aclitems, &naclitems))
140 : {
141 0 : free(aclitems);
142 0 : return false;
143 : }
144 :
145 : /* Parse the baseacls too */
146 0 : 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 0 : grantitems = (char **) pg_malloc(naclitems * sizeof(char *));
164 0 : for (i = 0; i < naclitems; i++)
165 : {
166 0 : bool found = false;
167 :
168 0 : for (int j = 0; j < nbaseitems; j++)
169 : {
170 0 : if (strcmp(aclitems[i], baseitems[j]) == 0)
171 : {
172 0 : found = true;
173 0 : break;
174 : }
175 0 : }
176 0 : if (!found)
177 0 : grantitems[ngrantitems++] = aclitems[i];
178 0 : }
179 0 : revokeitems = (char **) pg_malloc(nbaseitems * sizeof(char *));
180 0 : for (i = 0; i < nbaseitems; i++)
181 : {
182 0 : bool found = false;
183 :
184 0 : for (int j = 0; j < naclitems; j++)
185 : {
186 0 : if (strcmp(baseitems[i], aclitems[j]) == 0)
187 : {
188 0 : found = true;
189 0 : break;
190 : }
191 0 : }
192 0 : if (!found)
193 0 : revokeitems[nrevokeitems++] = baseitems[i];
194 0 : }
195 :
196 : /* Prepare working buffers */
197 0 : grantee = createPQExpBuffer();
198 0 : grantor = createPQExpBuffer();
199 0 : privs = createPQExpBuffer();
200 0 : privswgo = createPQExpBuffer();
201 :
202 : /*
203 : * At the end, these two will be pasted together to form the result.
204 : */
205 0 : firstsql = createPQExpBuffer();
206 0 : secondsql = createPQExpBuffer();
207 :
208 : /*
209 : * Build REVOKE statements for ACLs listed in revokeitems[].
210 : */
211 0 : for (i = 0; i < nrevokeitems; i++)
212 : {
213 0 : if (!parseAclItem(revokeitems[i],
214 0 : type, name, subname, remoteVersion,
215 0 : grantee, grantor, privs, NULL))
216 : {
217 0 : ok = false;
218 0 : break;
219 : }
220 :
221 0 : if (privs->len > 0)
222 : {
223 0 : appendPQExpBuffer(firstsql, "%sREVOKE %s ON %s ",
224 0 : prefix, privs->data, type);
225 0 : if (nspname && *nspname)
226 0 : appendPQExpBuffer(firstsql, "%s.", fmtId(nspname));
227 0 : if (name && *name)
228 0 : appendPQExpBuffer(firstsql, "%s ", name);
229 0 : appendPQExpBufferStr(firstsql, "FROM ");
230 0 : if (grantee->len == 0)
231 0 : appendPQExpBufferStr(firstsql, "PUBLIC;\n");
232 : else
233 0 : appendPQExpBuffer(firstsql, "%s;\n",
234 0 : fmtId(grantee->data));
235 0 : }
236 0 : }
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 0 : for (i = 0; i < ngrantitems; i++)
262 : {
263 0 : if (parseAclItem(grantitems[i], type, name, subname, remoteVersion,
264 0 : 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 0 : if (privs->len > 0 || privswgo->len > 0)
272 : {
273 0 : PQExpBuffer thissql;
274 :
275 : /* Set owner as grantor if that's not explicit in the ACL */
276 0 : if (grantor->len == 0 && owner)
277 0 : printfPQExpBuffer(grantor, "%s", owner);
278 :
279 : /* Make sure owner's own grants are output before others */
280 0 : if (owner &&
281 0 : strcmp(grantee->data, owner) == 0 &&
282 0 : strcmp(grantor->data, owner) == 0)
283 0 : thissql = firstsql;
284 : else
285 0 : thissql = secondsql;
286 :
287 0 : if (grantor->len > 0
288 0 : && (!owner || strcmp(owner, grantor->data) != 0))
289 0 : appendPQExpBuffer(thissql, "SET SESSION AUTHORIZATION %s;\n",
290 0 : fmtId(grantor->data));
291 :
292 0 : if (privs->len > 0)
293 : {
294 0 : appendPQExpBuffer(thissql, "%sGRANT %s ON %s ",
295 0 : prefix, privs->data, type);
296 0 : if (nspname && *nspname)
297 0 : appendPQExpBuffer(thissql, "%s.", fmtId(nspname));
298 0 : if (name && *name)
299 0 : appendPQExpBuffer(thissql, "%s ", name);
300 0 : appendPQExpBufferStr(thissql, "TO ");
301 0 : if (grantee->len == 0)
302 0 : appendPQExpBufferStr(thissql, "PUBLIC;\n");
303 : else
304 0 : appendPQExpBuffer(thissql, "%s;\n", fmtId(grantee->data));
305 0 : }
306 0 : if (privswgo->len > 0)
307 : {
308 0 : appendPQExpBuffer(thissql, "%sGRANT %s ON %s ",
309 0 : prefix, privswgo->data, type);
310 0 : if (nspname && *nspname)
311 0 : appendPQExpBuffer(thissql, "%s.", fmtId(nspname));
312 0 : if (name && *name)
313 0 : appendPQExpBuffer(thissql, "%s ", name);
314 0 : appendPQExpBufferStr(thissql, "TO ");
315 0 : if (grantee->len == 0)
316 0 : appendPQExpBufferStr(thissql, "PUBLIC");
317 : else
318 0 : appendPQExpBufferStr(thissql, fmtId(grantee->data));
319 0 : appendPQExpBufferStr(thissql, " WITH GRANT OPTION;\n");
320 0 : }
321 :
322 0 : if (grantor->len > 0
323 0 : && (!owner || strcmp(owner, grantor->data) != 0))
324 0 : appendPQExpBufferStr(thissql, "RESET SESSION AUTHORIZATION;\n");
325 0 : }
326 0 : }
327 : else
328 : {
329 : /* parseAclItem failed, give up */
330 0 : ok = false;
331 0 : break;
332 : }
333 0 : }
334 :
335 0 : destroyPQExpBuffer(grantee);
336 0 : destroyPQExpBuffer(grantor);
337 0 : destroyPQExpBuffer(privs);
338 0 : destroyPQExpBuffer(privswgo);
339 :
340 0 : appendPQExpBuffer(sql, "%s%s", firstsql->data, secondsql->data);
341 0 : destroyPQExpBuffer(firstsql);
342 0 : destroyPQExpBuffer(secondsql);
343 :
344 0 : free(aclitems);
345 0 : free(baseitems);
346 0 : free(grantitems);
347 0 : free(revokeitems);
348 :
349 0 : return ok;
350 0 : }
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 0 : 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 0 : PQExpBuffer prefix;
373 :
374 0 : 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 0 : appendPQExpBuffer(prefix, "ALTER DEFAULT PRIVILEGES FOR ROLE %s ",
383 0 : fmtId(owner));
384 0 : if (nspname)
385 0 : 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 0 : if (!buildACLCommands("", NULL, NULL, type,
392 0 : acls, acldefault, owner,
393 0 : prefix->data, remoteVersion, sql))
394 : {
395 0 : destroyPQExpBuffer(prefix);
396 0 : return false;
397 : }
398 :
399 0 : destroyPQExpBuffer(prefix);
400 :
401 0 : return true;
402 0 : }
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 0 : 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 0 : char *buf;
429 0 : bool all_with_go = true;
430 0 : bool all_without_go = true;
431 0 : char *eqpos;
432 0 : char *slpos;
433 0 : char *pos;
434 :
435 0 : buf = pg_strdup(item);
436 :
437 : /* user or group name is string up to = */
438 0 : eqpos = dequoteAclUserName(grantee, buf);
439 0 : if (*eqpos != '=')
440 : {
441 0 : pg_free(buf);
442 0 : return false;
443 : }
444 :
445 : /* grantor should appear after / */
446 0 : slpos = strchr(eqpos + 1, '/');
447 0 : if (slpos)
448 : {
449 0 : *slpos++ = '\0';
450 0 : slpos = dequoteAclUserName(grantor, slpos);
451 0 : if (*slpos != '\0')
452 : {
453 0 : pg_free(buf);
454 0 : return false;
455 : }
456 0 : }
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 0 : resetPQExpBuffer(privs);
484 0 : resetPQExpBuffer(privswgo);
485 :
486 0 : if (strcmp(type, "TABLE") == 0 || strcmp(type, "SEQUENCE") == 0 ||
487 0 : strcmp(type, "TABLES") == 0 || strcmp(type, "SEQUENCES") == 0)
488 : {
489 0 : CONVERT_PRIV('r', "SELECT");
490 :
491 0 : if (strcmp(type, "SEQUENCE") == 0 ||
492 0 : strcmp(type, "SEQUENCES") == 0)
493 : /* sequence only */
494 0 : CONVERT_PRIV('U', "USAGE");
495 : else
496 : {
497 : /* table only */
498 0 : CONVERT_PRIV('a', "INSERT");
499 0 : CONVERT_PRIV('x', "REFERENCES");
500 : /* rest are not applicable to columns */
501 0 : if (subname == NULL)
502 : {
503 0 : CONVERT_PRIV('d', "DELETE");
504 0 : CONVERT_PRIV('t', "TRIGGER");
505 0 : CONVERT_PRIV('D', "TRUNCATE");
506 0 : CONVERT_PRIV('m', "MAINTAIN");
507 0 : }
508 : }
509 :
510 : /* UPDATE */
511 0 : CONVERT_PRIV('w', "UPDATE");
512 0 : }
513 0 : else if (strcmp(type, "FUNCTION") == 0 ||
514 0 : strcmp(type, "FUNCTIONS") == 0)
515 0 : CONVERT_PRIV('X', "EXECUTE");
516 0 : else if (strcmp(type, "PROCEDURE") == 0 ||
517 0 : strcmp(type, "PROCEDURES") == 0)
518 0 : CONVERT_PRIV('X', "EXECUTE");
519 0 : else if (strcmp(type, "LANGUAGE") == 0)
520 0 : CONVERT_PRIV('U', "USAGE");
521 0 : else if (strcmp(type, "SCHEMA") == 0 ||
522 0 : strcmp(type, "SCHEMAS") == 0)
523 : {
524 0 : CONVERT_PRIV('C', "CREATE");
525 0 : CONVERT_PRIV('U', "USAGE");
526 0 : }
527 0 : else if (strcmp(type, "DATABASE") == 0)
528 : {
529 0 : CONVERT_PRIV('C', "CREATE");
530 0 : CONVERT_PRIV('c', "CONNECT");
531 0 : CONVERT_PRIV('T', "TEMPORARY");
532 0 : }
533 0 : else if (strcmp(type, "TABLESPACE") == 0)
534 0 : CONVERT_PRIV('C', "CREATE");
535 0 : else if (strcmp(type, "TYPE") == 0 ||
536 0 : strcmp(type, "TYPES") == 0)
537 0 : CONVERT_PRIV('U', "USAGE");
538 0 : else if (strcmp(type, "FOREIGN DATA WRAPPER") == 0)
539 0 : CONVERT_PRIV('U', "USAGE");
540 0 : else if (strcmp(type, "FOREIGN SERVER") == 0)
541 0 : CONVERT_PRIV('U', "USAGE");
542 0 : else if (strcmp(type, "FOREIGN TABLE") == 0)
543 0 : CONVERT_PRIV('r', "SELECT");
544 0 : else if (strcmp(type, "PARAMETER") == 0)
545 : {
546 0 : CONVERT_PRIV('s', "SET");
547 0 : CONVERT_PRIV('A', "ALTER SYSTEM");
548 0 : }
549 0 : else if (strcmp(type, "LARGE OBJECT") == 0 ||
550 0 : strcmp(type, "LARGE OBJECTS") == 0)
551 : {
552 0 : CONVERT_PRIV('r', "SELECT");
553 0 : CONVERT_PRIV('w', "UPDATE");
554 0 : }
555 : else
556 0 : abort();
557 :
558 : #undef CONVERT_PRIV
559 :
560 0 : if (all_with_go)
561 : {
562 0 : resetPQExpBuffer(privs);
563 0 : printfPQExpBuffer(privswgo, "ALL");
564 0 : if (subname)
565 0 : appendPQExpBuffer(privswgo, "(%s)", subname);
566 0 : }
567 0 : else if (all_without_go)
568 : {
569 0 : resetPQExpBuffer(privswgo);
570 0 : printfPQExpBuffer(privs, "ALL");
571 0 : if (subname)
572 0 : appendPQExpBuffer(privs, "(%s)", subname);
573 0 : }
574 :
575 0 : pg_free(buf);
576 :
577 0 : return true;
578 0 : }
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 0 : quoteAclUserName(PQExpBuffer output, const char *input)
586 : {
587 0 : const char *src;
588 0 : bool safe = true;
589 :
590 0 : for (src = input; *src; src++)
591 : {
592 : /* This test had better match what putid() does */
593 0 : if (!isalnum((unsigned char) *src) && *src != '_')
594 : {
595 0 : safe = false;
596 0 : break;
597 : }
598 0 : }
599 0 : if (!safe)
600 0 : appendPQExpBufferChar(output, '"');
601 0 : for (src = input; *src; src++)
602 : {
603 : /* A double quote character in a username is encoded as "" */
604 0 : if (*src == '"')
605 0 : appendPQExpBufferChar(output, '"');
606 0 : appendPQExpBufferChar(output, *src);
607 0 : }
608 0 : if (!safe)
609 0 : appendPQExpBufferChar(output, '"');
610 0 : }
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 0 : dequoteAclUserName(PQExpBuffer output, char *input)
620 : {
621 0 : resetPQExpBuffer(output);
622 :
623 0 : while (*input && *input != '=')
624 : {
625 : /*
626 : * If user name isn't quoted, then just add it to the output buffer
627 : */
628 0 : if (*input != '"')
629 0 : appendPQExpBufferChar(output, *input++);
630 : else
631 : {
632 : /* Otherwise, it's a quoted username */
633 0 : input++;
634 : /* Loop until we come across an unescaped quote */
635 0 : while (!(*input == '"' && *(input + 1) != '"'))
636 : {
637 0 : 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 0 : if (*input == '"' && *(input + 1) == '"')
645 0 : input++;
646 0 : appendPQExpBufferChar(output, *input++);
647 : }
648 0 : input++;
649 : }
650 : }
651 0 : return input;
652 0 : }
653 :
654 : /*
655 : * Append a privilege keyword to a keyword list, inserting comma if needed.
656 : */
657 : static void
658 0 : AddAcl(PQExpBuffer aclbuf, const char *keyword, const char *subname)
659 : {
660 0 : if (aclbuf->len > 0)
661 0 : appendPQExpBufferChar(aclbuf, ',');
662 0 : appendPQExpBufferStr(aclbuf, keyword);
663 0 : if (subname)
664 0 : appendPQExpBuffer(aclbuf, "(%s)", subname);
665 0 : }
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 0 : buildShSecLabelQuery(const char *catalog_name, Oid objectId,
679 : PQExpBuffer sql)
680 : {
681 0 : appendPQExpBuffer(sql,
682 : "SELECT provider, label FROM pg_catalog.pg_shseclabel "
683 : "WHERE classoid = 'pg_catalog.%s'::pg_catalog.regclass "
684 0 : "AND objoid = '%u'", catalog_name, objectId);
685 0 : }
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 0 : emitShSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
697 : const char *objtype, const char *objname)
698 : {
699 0 : int i;
700 :
701 0 : 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 0 : fmtId(provider), objtype);
710 0 : appendPQExpBuffer(buffer,
711 : " %s IS ",
712 0 : fmtId(objname));
713 0 : appendStringLiteralConn(buffer, label, conn);
714 0 : appendPQExpBufferStr(buffer, ";\n");
715 0 : }
716 0 : }
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_parameters.dat.
728 : */
729 : bool
730 0 : variable_is_guc_list_quote(const char *name)
731 : {
732 0 : if (pg_strcasecmp(name, "local_preload_libraries") == 0 ||
733 0 : pg_strcasecmp(name, "oauth_validator_libraries") == 0 ||
734 0 : pg_strcasecmp(name, "search_path") == 0 ||
735 0 : pg_strcasecmp(name, "session_preload_libraries") == 0 ||
736 0 : pg_strcasecmp(name, "shared_preload_libraries") == 0 ||
737 0 : pg_strcasecmp(name, "temp_tablespaces") == 0 ||
738 0 : pg_strcasecmp(name, "unix_socket_directories") == 0)
739 0 : return true;
740 : else
741 0 : return false;
742 0 : }
743 :
744 : /*
745 : * SplitGUCList --- parse a string containing identifiers or file names
746 : *
747 : * This is used to split the value of a GUC_LIST_QUOTE GUC variable, without
748 : * presuming whether the elements will be taken as identifiers or file names.
749 : * See comparable code in src/backend/utils/adt/varlena.c.
750 : *
751 : * Inputs:
752 : * rawstring: the input string; must be overwritable! On return, it's
753 : * been modified to contain the separated identifiers.
754 : * separator: the separator punctuation expected between identifiers
755 : * (typically '.' or ','). Whitespace may also appear around
756 : * identifiers.
757 : * Outputs:
758 : * namelist: receives a malloc'd, null-terminated array of pointers to
759 : * identifiers within rawstring. Caller should free this
760 : * even on error return.
761 : *
762 : * Returns true if okay, false if there is a syntax error in the string.
763 : */
764 : bool
765 0 : SplitGUCList(char *rawstring, char separator,
766 : char ***namelist)
767 : {
768 0 : char *nextp = rawstring;
769 0 : bool done = false;
770 0 : char **nextptr;
771 :
772 : /*
773 : * Since we disallow empty identifiers, this is a conservative
774 : * overestimate of the number of pointers we could need. Allow one for
775 : * list terminator.
776 : */
777 0 : *namelist = nextptr = (char **)
778 0 : pg_malloc((strlen(rawstring) / 2 + 2) * sizeof(char *));
779 0 : *nextptr = NULL;
780 :
781 0 : while (isspace((unsigned char) *nextp))
782 0 : nextp++; /* skip leading whitespace */
783 :
784 0 : if (*nextp == '\0')
785 0 : return true; /* empty string represents empty list */
786 :
787 : /* At the top of the loop, we are at start of a new identifier. */
788 0 : do
789 : {
790 0 : char *curname;
791 0 : char *endp;
792 :
793 0 : if (*nextp == '"')
794 : {
795 : /* Quoted name --- collapse quote-quote pairs */
796 0 : curname = nextp + 1;
797 0 : for (;;)
798 : {
799 0 : endp = strchr(nextp + 1, '"');
800 0 : if (endp == NULL)
801 0 : return false; /* mismatched quotes */
802 0 : if (endp[1] != '"')
803 0 : break; /* found end of quoted name */
804 : /* Collapse adjacent quotes into one quote, and look again */
805 0 : memmove(endp, endp + 1, strlen(endp));
806 0 : nextp = endp;
807 : }
808 : /* endp now points at the terminating quote */
809 0 : nextp = endp + 1;
810 0 : }
811 : else
812 : {
813 : /* Unquoted name --- extends to separator or whitespace */
814 0 : curname = nextp;
815 0 : while (*nextp && *nextp != separator &&
816 0 : !isspace((unsigned char) *nextp))
817 0 : nextp++;
818 0 : endp = nextp;
819 0 : if (curname == nextp)
820 0 : return false; /* empty unquoted name not allowed */
821 : }
822 :
823 0 : while (isspace((unsigned char) *nextp))
824 0 : nextp++; /* skip trailing whitespace */
825 :
826 0 : if (*nextp == separator)
827 : {
828 0 : nextp++;
829 0 : while (isspace((unsigned char) *nextp))
830 0 : nextp++; /* skip leading whitespace for next */
831 : /* we expect another name, so done remains false */
832 0 : }
833 0 : else if (*nextp == '\0')
834 0 : done = true;
835 : else
836 0 : return false; /* invalid syntax */
837 :
838 : /* Now safe to overwrite separator with a null */
839 0 : *endp = '\0';
840 :
841 : /*
842 : * Finished isolating current name --- add it to output array
843 : */
844 0 : *nextptr++ = curname;
845 :
846 : /* Loop back if we didn't reach end of string */
847 0 : } while (!done);
848 :
849 0 : *nextptr = NULL;
850 0 : return true;
851 0 : }
852 :
853 : /*
854 : * Helper function for dumping "ALTER DATABASE/ROLE SET ..." commands.
855 : *
856 : * Parse the contents of configitem (a "name=value" string), wrap it in
857 : * a complete ALTER command, and append it to buf.
858 : *
859 : * type is DATABASE or ROLE, and name is the name of the database or role.
860 : * If we need an "IN" clause, type2 and name2 similarly define what to put
861 : * there; otherwise they should be NULL.
862 : * conn is used only to determine string-literal quoting conventions.
863 : */
864 : void
865 0 : makeAlterConfigCommand(PGconn *conn, const char *configitem,
866 : const char *type, const char *name,
867 : const char *type2, const char *name2,
868 : PQExpBuffer buf)
869 : {
870 0 : char *mine;
871 0 : char *pos;
872 :
873 : /* Parse the configitem. If we can't find an "=", silently do nothing. */
874 0 : mine = pg_strdup(configitem);
875 0 : pos = strchr(mine, '=');
876 0 : if (pos == NULL)
877 : {
878 0 : pg_free(mine);
879 0 : return;
880 : }
881 0 : *pos++ = '\0';
882 :
883 : /* Build the command, with suitable quoting for everything. */
884 0 : appendPQExpBuffer(buf, "ALTER %s %s ", type, fmtId(name));
885 0 : if (type2 != NULL && name2 != NULL)
886 0 : appendPQExpBuffer(buf, "IN %s %s ", type2, fmtId(name2));
887 0 : appendPQExpBuffer(buf, "SET %s TO ", fmtId(mine));
888 :
889 : /*
890 : * Variables that are marked GUC_LIST_QUOTE were already fully quoted by
891 : * flatten_set_variable_args() before they were put into the setconfig
892 : * array. However, because the quoting rules used there aren't exactly
893 : * like SQL's, we have to break the list value apart and then quote the
894 : * elements as string literals. (The elements may be double-quoted as-is,
895 : * but we can't just feed them to the SQL parser; it would do the wrong
896 : * thing with elements that are zero-length or longer than NAMEDATALEN.)
897 : * Also, we need a special case for empty lists.
898 : *
899 : * Variables that are not so marked should just be emitted as simple
900 : * string literals. If the variable is not known to
901 : * variable_is_guc_list_quote(), we'll do that; this makes it unsafe to
902 : * use GUC_LIST_QUOTE for extension variables.
903 : */
904 0 : if (variable_is_guc_list_quote(mine))
905 : {
906 0 : char **namelist;
907 0 : char **nameptr;
908 :
909 : /* Parse string into list of identifiers */
910 : /* this shouldn't fail really */
911 0 : if (SplitGUCList(pos, ',', &namelist))
912 : {
913 : /* Special case: represent an empty list as NULL */
914 0 : if (*namelist == NULL)
915 0 : appendPQExpBufferStr(buf, "NULL");
916 0 : for (nameptr = namelist; *nameptr; nameptr++)
917 : {
918 0 : if (nameptr != namelist)
919 0 : appendPQExpBufferStr(buf, ", ");
920 0 : appendStringLiteralConn(buf, *nameptr, conn);
921 0 : }
922 0 : }
923 0 : pg_free(namelist);
924 0 : }
925 : else
926 0 : appendStringLiteralConn(buf, pos, conn);
927 :
928 0 : appendPQExpBufferStr(buf, ";\n");
929 :
930 0 : pg_free(mine);
931 0 : }
932 :
933 : /*
934 : * create_or_open_dir
935 : *
936 : * This will create a new directory with the given dirname. If there is
937 : * already an empty directory with that name, then use it.
938 : */
939 : void
940 0 : create_or_open_dir(const char *dirname)
941 : {
942 0 : int ret;
943 :
944 0 : switch ((ret = pg_check_dir(dirname)))
945 : {
946 : case -1:
947 : /* opendir failed but not with ENOENT */
948 0 : pg_fatal("could not open directory \"%s\": %m", dirname);
949 0 : break;
950 : case 0:
951 : /* directory does not exist */
952 0 : if (mkdir(dirname, pg_dir_create_mode) < 0)
953 0 : pg_fatal("could not create directory \"%s\": %m", dirname);
954 0 : break;
955 : case 1:
956 : /* exists and is empty, fix perms */
957 0 : if (chmod(dirname, pg_dir_create_mode) != 0)
958 0 : pg_fatal("could not change permissions of directory \"%s\": %m",
959 : dirname);
960 0 : break;
961 : default:
962 : /* exists and is not empty */
963 0 : pg_fatal("directory \"%s\" is not empty", dirname);
964 0 : }
965 0 : }
966 :
967 : /*
968 : * Generates a valid restrict key (i.e., an alphanumeric string) for use with
969 : * psql's \restrict and \unrestrict meta-commands. For safety, the value is
970 : * chosen at random.
971 : */
972 : char *
973 0 : generate_restrict_key(void)
974 : {
975 0 : uint8 buf[64];
976 0 : char *ret = palloc(sizeof(buf));
977 :
978 0 : if (!pg_strong_random(buf, sizeof(buf)))
979 0 : return NULL;
980 :
981 0 : for (int i = 0; i < sizeof(buf) - 1; i++)
982 : {
983 0 : uint8 idx = buf[i] % strlen(restrict_chars);
984 :
985 0 : ret[i] = restrict_chars[idx];
986 0 : }
987 0 : ret[sizeof(buf) - 1] = '\0';
988 :
989 0 : return ret;
990 0 : }
991 :
992 : /*
993 : * Checks that a given restrict key (intended for use with psql's \restrict and
994 : * \unrestrict meta-commands) contains only alphanumeric characters.
995 : */
996 : bool
997 0 : valid_restrict_key(const char *restrict_key)
998 : {
999 0 : return restrict_key != NULL &&
1000 0 : restrict_key[0] != '\0' &&
1001 0 : strspn(restrict_key, restrict_chars) == strlen(restrict_key);
1002 : }
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