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) 1996-2017, 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 *copyAclUserName(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, LANGUAGE, SCHEMA, DATABASE, TABLESPACE,
40 * FOREIGN DATA WRAPPER, SERVER, or LARGE OBJECT)
41 * acls: the ACL string fetched from the database
42 * racls: the ACL string of any initial-but-now-revoked privileges
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 * Note: when processing a default ACL, prefix is "ALTER DEFAULT PRIVILEGES "
52 * or something similar, and name is an empty string.
53 *
54 * Note: beware of passing a fmtId() result directly as 'name' or 'subname',
55 * since this routine uses fmtId() internally.
56 */
57 bool
buildACLCommands(const char * name,const char * subname,const char * nspname,const char * type,const char * acls,const char * racls,const char * owner,const char * prefix,int remoteVersion,PQExpBuffer sql)58 buildACLCommands(const char *name, const char *subname, const char *nspname,
59 const char *type, const char *acls, const char *racls,
60 const char *owner, const char *prefix, int remoteVersion,
61 PQExpBuffer sql)
62 {
63 bool ok = true;
64 char **aclitems = NULL;
65 char **raclitems = NULL;
66 int naclitems = 0;
67 int nraclitems = 0;
68 int i;
69 PQExpBuffer grantee,
70 grantor,
71 privs,
72 privswgo;
73 PQExpBuffer firstsql,
74 secondsql;
75 bool found_owner_privs = false;
76
77 if (strlen(acls) == 0 && strlen(racls) == 0)
78 return true; /* object has default permissions */
79
80 /* treat empty-string owner same as NULL */
81 if (owner && *owner == '\0')
82 owner = NULL;
83
84 if (strlen(acls) != 0)
85 {
86 if (!parsePGArray(acls, &aclitems, &naclitems))
87 {
88 if (aclitems)
89 free(aclitems);
90 return false;
91 }
92 }
93
94 if (strlen(racls) != 0)
95 {
96 if (!parsePGArray(racls, &raclitems, &nraclitems))
97 {
98 if (raclitems)
99 free(raclitems);
100 return false;
101 }
102 }
103
104 grantee = createPQExpBuffer();
105 grantor = createPQExpBuffer();
106 privs = createPQExpBuffer();
107 privswgo = createPQExpBuffer();
108
109 /*
110 * At the end, these two will be pasted together to form the result.
111 *
112 * For older systems we use these to ensure that the owner privileges go
113 * before the other ones, as a GRANT could create the default entry for
114 * the object, which generally includes all rights for the owner. In more
115 * recent versions we normally handle this because the owner rights come
116 * first in the ACLs, but older versions might have them after the PUBLIC
117 * privileges.
118 *
119 * For 9.6 and later systems, much of this changes. With 9.6, we check
120 * the default privileges for the objects at dump time and create two sets
121 * of ACLs- "racls" which are the ACLs to REVOKE from the object (as the
122 * object may have initial privileges on it, along with any default ACLs
123 * which are not part of the current set of privileges), and regular
124 * "acls", which are the ACLs to GRANT to the object. We handle the
125 * REVOKEs first, followed by the GRANTs.
126 */
127 firstsql = createPQExpBuffer();
128 secondsql = createPQExpBuffer();
129
130 /*
131 * For pre-9.6 systems, we always start with REVOKE ALL FROM PUBLIC, as we
132 * don't wish to make any assumptions about what the default ACLs are, and
133 * we do not collect them during the dump phase (and racls will always be
134 * the empty set, see above).
135 *
136 * For 9.6 and later, if any revoke ACLs have been provided, then include
137 * them in 'firstsql'.
138 *
139 * Revoke ACLs happen when an object starts out life with a set of
140 * privileges (eg: GRANT SELECT ON pg_class TO PUBLIC;) and the user has
141 * decided to revoke those rights. Since those objects come into being
142 * with those default privileges, we have to revoke them to match what the
143 * current state of affairs is. Note that we only started explicitly
144 * tracking such initial rights in 9.6, and prior to that all initial
145 * rights are actually handled by the simple 'REVOKE ALL .. FROM PUBLIC'
146 * case, for initdb-created objects. Prior to 9.6, we didn't handle
147 * extensions correctly, but we do now by tracking their initial
148 * privileges, in the same way we track initdb initial privileges, see
149 * pg_init_privs.
150 */
151 if (remoteVersion < 90600)
152 {
153 Assert(nraclitems == 0);
154
155 appendPQExpBuffer(firstsql, "%sREVOKE ALL", prefix);
156 if (subname)
157 appendPQExpBuffer(firstsql, "(%s)", subname);
158 appendPQExpBuffer(firstsql, " ON %s ", type);
159 if (nspname && *nspname)
160 appendPQExpBuffer(firstsql, "%s.", fmtId(nspname));
161 appendPQExpBuffer(firstsql, "%s FROM PUBLIC;\n", name);
162 }
163 else
164 {
165 /* Scan individual REVOKE ACL items */
166 for (i = 0; i < nraclitems; i++)
167 {
168 if (!parseAclItem(raclitems[i], type, name, subname, remoteVersion,
169 grantee, grantor, privs, NULL))
170 {
171 ok = false;
172 break;
173 }
174
175 if (privs->len > 0)
176 {
177 appendPQExpBuffer(firstsql, "%sREVOKE %s ON %s ",
178 prefix, privs->data, type);
179 if (nspname && *nspname)
180 appendPQExpBuffer(firstsql, "%s.", fmtId(nspname));
181 appendPQExpBuffer(firstsql, "%s FROM ", name);
182 if (grantee->len == 0)
183 appendPQExpBufferStr(firstsql, "PUBLIC;\n");
184 else if (strncmp(grantee->data, "group ",
185 strlen("group ")) == 0)
186 appendPQExpBuffer(firstsql, "GROUP %s;\n",
187 fmtId(grantee->data + strlen("group ")));
188 else
189 appendPQExpBuffer(firstsql, "%s;\n",
190 fmtId(grantee->data));
191 }
192 }
193 }
194
195 /*
196 * We still need some hacking though to cover the case where new default
197 * public privileges are added in new versions: the REVOKE ALL will revoke
198 * them, leading to behavior different from what the old version had,
199 * which is generally not what's wanted. So add back default privs if the
200 * source database is too old to have had that particular priv.
201 */
202 if (remoteVersion < 80200 && strcmp(type, "DATABASE") == 0)
203 {
204 /* database CONNECT priv didn't exist before 8.2 */
205 appendPQExpBuffer(firstsql, "%sGRANT CONNECT ON %s %s TO PUBLIC;\n",
206 prefix, type, name);
207 }
208
209 /* Scan individual ACL items */
210 for (i = 0; i < naclitems; i++)
211 {
212 if (!parseAclItem(aclitems[i], type, name, subname, remoteVersion,
213 grantee, grantor, privs, privswgo))
214 {
215 ok = false;
216 break;
217 }
218
219 if (grantor->len == 0 && owner)
220 printfPQExpBuffer(grantor, "%s", owner);
221
222 if (privs->len > 0 || privswgo->len > 0)
223 {
224 /*
225 * Prior to 9.6, we had to handle owner privileges in a special
226 * manner by first REVOKE'ing the rights and then GRANT'ing them
227 * after. With 9.6 and above, what we need to REVOKE and what we
228 * need to GRANT is figured out when we dump and stashed into
229 * "racls" and "acls", respectively. See above.
230 */
231 if (remoteVersion < 90600 && owner
232 && strcmp(grantee->data, owner) == 0
233 && strcmp(grantor->data, owner) == 0)
234 {
235 found_owner_privs = true;
236
237 /*
238 * For the owner, the default privilege level is ALL WITH
239 * GRANT OPTION.
240 */
241 if (strcmp(privswgo->data, "ALL") != 0)
242 {
243 appendPQExpBuffer(firstsql, "%sREVOKE ALL", prefix);
244 if (subname)
245 appendPQExpBuffer(firstsql, "(%s)", subname);
246 appendPQExpBuffer(firstsql, " ON %s ", type);
247 if (nspname && *nspname)
248 appendPQExpBuffer(firstsql, "%s.", fmtId(nspname));
249 appendPQExpBuffer(firstsql, "%s FROM %s;\n",
250 name, fmtId(grantee->data));
251 if (privs->len > 0)
252 {
253 appendPQExpBuffer(firstsql,
254 "%sGRANT %s ON %s ",
255 prefix, privs->data, type);
256 if (nspname && *nspname)
257 appendPQExpBuffer(firstsql, "%s.", fmtId(nspname));
258 appendPQExpBuffer(firstsql,
259 "%s TO %s;\n",
260 name, fmtId(grantee->data));
261 }
262 if (privswgo->len > 0)
263 {
264 appendPQExpBuffer(firstsql,
265 "%sGRANT %s ON %s ",
266 prefix, privswgo->data, type);
267 if (nspname && *nspname)
268 appendPQExpBuffer(firstsql, "%s.", fmtId(nspname));
269 appendPQExpBuffer(firstsql,
270 "%s TO %s WITH GRANT OPTION;\n",
271 name, fmtId(grantee->data));
272 }
273 }
274 }
275 else
276 {
277 /*
278 * For systems prior to 9.6, we can assume we are starting
279 * from no privs at this point.
280 *
281 * For 9.6 and above, at this point we have issued REVOKE
282 * statements for all initial and default privileges which are
283 * no longer present on the object (as they were passed in as
284 * 'racls') and we can simply GRANT the rights which are in
285 * 'acls'.
286 */
287 if (grantor->len > 0
288 && (!owner || strcmp(owner, grantor->data) != 0))
289 appendPQExpBuffer(secondsql, "SET SESSION AUTHORIZATION %s;\n",
290 fmtId(grantor->data));
291
292 if (privs->len > 0)
293 {
294 appendPQExpBuffer(secondsql, "%sGRANT %s ON %s ",
295 prefix, privs->data, type);
296 if (nspname && *nspname)
297 appendPQExpBuffer(secondsql, "%s.", fmtId(nspname));
298 appendPQExpBuffer(secondsql, "%s TO ", name);
299 if (grantee->len == 0)
300 appendPQExpBufferStr(secondsql, "PUBLIC;\n");
301 else if (strncmp(grantee->data, "group ",
302 strlen("group ")) == 0)
303 appendPQExpBuffer(secondsql, "GROUP %s;\n",
304 fmtId(grantee->data + strlen("group ")));
305 else
306 appendPQExpBuffer(secondsql, "%s;\n", fmtId(grantee->data));
307 }
308 if (privswgo->len > 0)
309 {
310 appendPQExpBuffer(secondsql, "%sGRANT %s ON %s ",
311 prefix, privswgo->data, type);
312 if (nspname && *nspname)
313 appendPQExpBuffer(secondsql, "%s.", fmtId(nspname));
314 appendPQExpBuffer(secondsql, "%s TO ", name);
315 if (grantee->len == 0)
316 appendPQExpBufferStr(secondsql, "PUBLIC");
317 else if (strncmp(grantee->data, "group ",
318 strlen("group ")) == 0)
319 appendPQExpBuffer(secondsql, "GROUP %s",
320 fmtId(grantee->data + strlen("group ")));
321 else
322 appendPQExpBufferStr(secondsql, fmtId(grantee->data));
323 appendPQExpBufferStr(secondsql, " WITH GRANT OPTION;\n");
324 }
325
326 if (grantor->len > 0
327 && (!owner || strcmp(owner, grantor->data) != 0))
328 appendPQExpBufferStr(secondsql, "RESET SESSION AUTHORIZATION;\n");
329 }
330 }
331 }
332
333 /*
334 * For systems prior to 9.6, if we didn't find any owner privs, the owner
335 * must have revoked 'em all.
336 *
337 * For 9.6 and above, we handle this through the 'racls'. See above.
338 */
339 if (remoteVersion < 90600 && !found_owner_privs && owner)
340 {
341 appendPQExpBuffer(firstsql, "%sREVOKE ALL", prefix);
342 if (subname)
343 appendPQExpBuffer(firstsql, "(%s)", subname);
344 appendPQExpBuffer(firstsql, " ON %s ", type);
345 if (nspname && *nspname)
346 appendPQExpBuffer(firstsql, "%s.", fmtId(nspname));
347 appendPQExpBuffer(firstsql, "%s FROM %s;\n",
348 name, fmtId(owner));
349 }
350
351 destroyPQExpBuffer(grantee);
352 destroyPQExpBuffer(grantor);
353 destroyPQExpBuffer(privs);
354 destroyPQExpBuffer(privswgo);
355
356 appendPQExpBuffer(sql, "%s%s", firstsql->data, secondsql->data);
357 destroyPQExpBuffer(firstsql);
358 destroyPQExpBuffer(secondsql);
359
360 if (aclitems)
361 free(aclitems);
362
363 if (raclitems)
364 free(raclitems);
365
366 return ok;
367 }
368
369 /*
370 * Build ALTER DEFAULT PRIVILEGES command(s) for single pg_default_acl entry.
371 *
372 * type: the object type (TABLES, FUNCTIONS, etc)
373 * nspname: schema name, or NULL for global default privileges
374 * acls: the ACL string fetched from the database
375 * owner: username of privileges owner (will be passed through fmtId)
376 * remoteVersion: version of database
377 *
378 * Returns TRUE if okay, FALSE if could not parse the acl string.
379 * The resulting commands (if any) are appended to the contents of 'sql'.
380 */
381 bool
buildDefaultACLCommands(const char * type,const char * nspname,const char * acls,const char * racls,const char * initacls,const char * initracls,const char * owner,int remoteVersion,PQExpBuffer sql)382 buildDefaultACLCommands(const char *type, const char *nspname,
383 const char *acls, const char *racls,
384 const char *initacls, const char *initracls,
385 const char *owner,
386 int remoteVersion,
387 PQExpBuffer sql)
388 {
389 PQExpBuffer prefix;
390
391 prefix = createPQExpBuffer();
392
393 /*
394 * We incorporate the target role directly into the command, rather than
395 * playing around with SET ROLE or anything like that. This is so that a
396 * permissions error leads to nothing happening, rather than changing
397 * default privileges for the wrong user.
398 */
399 appendPQExpBuffer(prefix, "ALTER DEFAULT PRIVILEGES FOR ROLE %s ",
400 fmtId(owner));
401 if (nspname)
402 appendPQExpBuffer(prefix, "IN SCHEMA %s ", fmtId(nspname));
403
404 if (strlen(initacls) != 0 || strlen(initracls) != 0)
405 {
406 appendPQExpBuffer(sql, "SELECT pg_catalog.binary_upgrade_set_record_init_privs(true);\n");
407 if (!buildACLCommands("", NULL, NULL, type,
408 initacls, initracls, owner,
409 prefix->data, remoteVersion, sql))
410 {
411 destroyPQExpBuffer(prefix);
412 return false;
413 }
414 appendPQExpBuffer(sql, "SELECT pg_catalog.binary_upgrade_set_record_init_privs(false);\n");
415 }
416
417 if (!buildACLCommands("", NULL, NULL, type,
418 acls, racls, owner,
419 prefix->data, remoteVersion, sql))
420 {
421 destroyPQExpBuffer(prefix);
422 return false;
423 }
424
425 destroyPQExpBuffer(prefix);
426
427 return true;
428 }
429
430 /*
431 * This will parse an aclitem string, having the general form
432 * username=privilegecodes/grantor
433 * or
434 * group groupname=privilegecodes/grantor
435 * (the "group" case occurs only with servers before 8.1).
436 *
437 * Returns true on success, false on parse error. On success, the components
438 * of the string are returned in the PQExpBuffer parameters.
439 *
440 * The returned grantee string will be the dequoted username or groupname
441 * (preceded with "group " in the latter case). Note that a grant to PUBLIC
442 * is represented by an empty grantee string. The returned grantor is the
443 * dequoted grantor name. Privilege characters are translated to GRANT/REVOKE
444 * comma-separated privileges lists. If "privswgo" is non-NULL, the result is
445 * separate lists for privileges with grant option ("privswgo") and without
446 * ("privs"). Otherwise, "privs" bears every relevant privilege, ignoring the
447 * grant option distinction.
448 *
449 * Note: for cross-version compatibility, it's important to use ALL to
450 * represent the privilege sets whenever appropriate.
451 */
452 static bool
parseAclItem(const char * item,const char * type,const char * name,const char * subname,int remoteVersion,PQExpBuffer grantee,PQExpBuffer grantor,PQExpBuffer privs,PQExpBuffer privswgo)453 parseAclItem(const char *item, const char *type,
454 const char *name, const char *subname, int remoteVersion,
455 PQExpBuffer grantee, PQExpBuffer grantor,
456 PQExpBuffer privs, PQExpBuffer privswgo)
457 {
458 char *buf;
459 bool all_with_go = true;
460 bool all_without_go = true;
461 char *eqpos;
462 char *slpos;
463 char *pos;
464
465 buf = strdup(item);
466 if (!buf)
467 return false;
468
469 /* user or group name is string up to = */
470 eqpos = copyAclUserName(grantee, buf);
471 if (*eqpos != '=')
472 {
473 free(buf);
474 return false;
475 }
476
477 /* grantor should appear after / */
478 slpos = strchr(eqpos + 1, '/');
479 if (slpos)
480 {
481 *slpos++ = '\0';
482 slpos = copyAclUserName(grantor, slpos);
483 if (*slpos != '\0')
484 {
485 free(buf);
486 return false;
487 }
488 }
489 else
490 {
491 free(buf);
492 return false;
493 }
494
495 /* privilege codes */
496 #define CONVERT_PRIV(code, keywd) \
497 do { \
498 if ((pos = strchr(eqpos + 1, code))) \
499 { \
500 if (*(pos + 1) == '*' && privswgo != NULL) \
501 { \
502 AddAcl(privswgo, keywd, subname); \
503 all_without_go = false; \
504 } \
505 else \
506 { \
507 AddAcl(privs, keywd, subname); \
508 all_with_go = false; \
509 } \
510 } \
511 else \
512 all_with_go = all_without_go = false; \
513 } while (0)
514
515 resetPQExpBuffer(privs);
516 resetPQExpBuffer(privswgo);
517
518 if (strcmp(type, "TABLE") == 0 || strcmp(type, "SEQUENCE") == 0 ||
519 strcmp(type, "TABLES") == 0 || strcmp(type, "SEQUENCES") == 0)
520 {
521 CONVERT_PRIV('r', "SELECT");
522
523 if (strcmp(type, "SEQUENCE") == 0 ||
524 strcmp(type, "SEQUENCES") == 0)
525 /* sequence only */
526 CONVERT_PRIV('U', "USAGE");
527 else
528 {
529 /* table only */
530 CONVERT_PRIV('a', "INSERT");
531 CONVERT_PRIV('x', "REFERENCES");
532 /* rest are not applicable to columns */
533 if (subname == NULL)
534 {
535 CONVERT_PRIV('d', "DELETE");
536 CONVERT_PRIV('t', "TRIGGER");
537 if (remoteVersion >= 80400)
538 CONVERT_PRIV('D', "TRUNCATE");
539 }
540 }
541
542 /* UPDATE */
543 CONVERT_PRIV('w', "UPDATE");
544 }
545 else if (strcmp(type, "FUNCTION") == 0 ||
546 strcmp(type, "FUNCTIONS") == 0)
547 CONVERT_PRIV('X', "EXECUTE");
548 else if (strcmp(type, "LANGUAGE") == 0)
549 CONVERT_PRIV('U', "USAGE");
550 else if (strcmp(type, "SCHEMA") == 0 ||
551 strcmp(type, "SCHEMAS") == 0)
552 {
553 CONVERT_PRIV('C', "CREATE");
554 CONVERT_PRIV('U', "USAGE");
555 }
556 else if (strcmp(type, "DATABASE") == 0)
557 {
558 CONVERT_PRIV('C', "CREATE");
559 CONVERT_PRIV('c', "CONNECT");
560 CONVERT_PRIV('T', "TEMPORARY");
561 }
562 else if (strcmp(type, "TABLESPACE") == 0)
563 CONVERT_PRIV('C', "CREATE");
564 else if (strcmp(type, "TYPE") == 0 ||
565 strcmp(type, "TYPES") == 0)
566 CONVERT_PRIV('U', "USAGE");
567 else if (strcmp(type, "FOREIGN DATA WRAPPER") == 0)
568 CONVERT_PRIV('U', "USAGE");
569 else if (strcmp(type, "FOREIGN SERVER") == 0)
570 CONVERT_PRIV('U', "USAGE");
571 else if (strcmp(type, "FOREIGN TABLE") == 0)
572 CONVERT_PRIV('r', "SELECT");
573 else if (strcmp(type, "LARGE OBJECT") == 0)
574 {
575 CONVERT_PRIV('r', "SELECT");
576 CONVERT_PRIV('w', "UPDATE");
577 }
578 else
579 abort();
580
581 #undef CONVERT_PRIV
582
583 if (all_with_go)
584 {
585 resetPQExpBuffer(privs);
586 printfPQExpBuffer(privswgo, "ALL");
587 if (subname)
588 appendPQExpBuffer(privswgo, "(%s)", subname);
589 }
590 else if (all_without_go)
591 {
592 resetPQExpBuffer(privswgo);
593 printfPQExpBuffer(privs, "ALL");
594 if (subname)
595 appendPQExpBuffer(privs, "(%s)", subname);
596 }
597
598 free(buf);
599
600 return true;
601 }
602
603 /*
604 * Transfer a user or group name starting at *input into the output buffer,
605 * dequoting if needed. Returns a pointer to just past the input name.
606 * The name is taken to end at an unquoted '=' or end of string.
607 */
608 static char *
copyAclUserName(PQExpBuffer output,char * input)609 copyAclUserName(PQExpBuffer output, char *input)
610 {
611 resetPQExpBuffer(output);
612
613 while (*input && *input != '=')
614 {
615 /*
616 * If user name isn't quoted, then just add it to the output buffer
617 */
618 if (*input != '"')
619 appendPQExpBufferChar(output, *input++);
620 else
621 {
622 /* Otherwise, it's a quoted username */
623 input++;
624 /* Loop until we come across an unescaped quote */
625 while (!(*input == '"' && *(input + 1) != '"'))
626 {
627 if (*input == '\0')
628 return input; /* really a syntax error... */
629
630 /*
631 * Quoting convention is to escape " as "". Keep this code in
632 * sync with putid() in backend's acl.c.
633 */
634 if (*input == '"' && *(input + 1) == '"')
635 input++;
636 appendPQExpBufferChar(output, *input++);
637 }
638 input++;
639 }
640 }
641 return input;
642 }
643
644 /*
645 * Append a privilege keyword to a keyword list, inserting comma if needed.
646 */
647 static void
AddAcl(PQExpBuffer aclbuf,const char * keyword,const char * subname)648 AddAcl(PQExpBuffer aclbuf, const char *keyword, const char *subname)
649 {
650 if (aclbuf->len > 0)
651 appendPQExpBufferChar(aclbuf, ',');
652 appendPQExpBufferStr(aclbuf, keyword);
653 if (subname)
654 appendPQExpBuffer(aclbuf, "(%s)", subname);
655 }
656
657
658 /*
659 * buildShSecLabelQuery
660 *
661 * Build a query to retrieve security labels for a shared object.
662 * The object is identified by its OID plus the name of the catalog
663 * it can be found in (e.g., "pg_database" for database names).
664 * The query is appended to "sql". (We don't execute it here so as to
665 * keep this file free of assumptions about how to deal with SQL errors.)
666 */
667 void
buildShSecLabelQuery(PGconn * conn,const char * catalog_name,Oid objectId,PQExpBuffer sql)668 buildShSecLabelQuery(PGconn *conn, const char *catalog_name, Oid objectId,
669 PQExpBuffer sql)
670 {
671 appendPQExpBuffer(sql,
672 "SELECT provider, label FROM pg_catalog.pg_shseclabel "
673 "WHERE classoid = 'pg_catalog.%s'::pg_catalog.regclass "
674 "AND objoid = '%u'", catalog_name, objectId);
675 }
676
677 /*
678 * emitShSecLabels
679 *
680 * Construct SECURITY LABEL commands using the data retrieved by the query
681 * generated by buildShSecLabelQuery, and append them to "buffer".
682 * Here, the target object is identified by its type name (e.g. "DATABASE")
683 * and its name (not pre-quoted).
684 */
685 void
emitShSecLabels(PGconn * conn,PGresult * res,PQExpBuffer buffer,const char * objtype,const char * objname)686 emitShSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
687 const char *objtype, const char *objname)
688 {
689 int i;
690
691 for (i = 0; i < PQntuples(res); i++)
692 {
693 char *provider = PQgetvalue(res, i, 0);
694 char *label = PQgetvalue(res, i, 1);
695
696 /* must use fmtId result before calling it again */
697 appendPQExpBuffer(buffer,
698 "SECURITY LABEL FOR %s ON %s",
699 fmtId(provider), objtype);
700 appendPQExpBuffer(buffer,
701 " %s IS ",
702 fmtId(objname));
703 appendStringLiteralConn(buffer, label, conn);
704 appendPQExpBufferStr(buffer, ";\n");
705 }
706 }
707
708 /*
709 * buildACLQueries
710 *
711 * Build the subqueries to extract out the correct set of ACLs to be
712 * GRANT'd and REVOKE'd for the specific kind of object, accounting for any
713 * initial privileges (from pg_init_privs) and based on if we are in binary
714 * upgrade mode or not.
715 *
716 * Also builds subqueries to extract out the set of ACLs to go from the object
717 * default privileges to the privileges in pg_init_privs, if we are in binary
718 * upgrade mode, so that those privileges can be set up and recorded in the new
719 * cluster before the regular privileges are added on top of those.
720 */
721 void
buildACLQueries(PQExpBuffer acl_subquery,PQExpBuffer racl_subquery,PQExpBuffer init_acl_subquery,PQExpBuffer init_racl_subquery,const char * acl_column,const char * acl_owner,const char * obj_kind,bool binary_upgrade)722 buildACLQueries(PQExpBuffer acl_subquery, PQExpBuffer racl_subquery,
723 PQExpBuffer init_acl_subquery, PQExpBuffer init_racl_subquery,
724 const char *acl_column, const char *acl_owner,
725 const char *obj_kind, bool binary_upgrade)
726 {
727 /*
728 * To get the delta from what the permissions were at creation time
729 * (either initdb or CREATE EXTENSION) vs. what they are now, we have to
730 * look at two things:
731 *
732 * What privileges have been added, which we calculate by extracting all
733 * the current privileges (using the set of default privileges for the
734 * object type if current privileges are NULL) and then removing those
735 * which existed at creation time (again, using the set of default
736 * privileges for the object type if there were no creation time
737 * privileges).
738 *
739 * What privileges have been removed, which we calculate by extracting the
740 * privileges as they were at creation time (or the default privileges, as
741 * above), and then removing the current privileges (or the default
742 * privileges, if current privileges are NULL).
743 *
744 * As a good cross-check, both directions of these checks should result in
745 * the empty set if both the current ACL and the initial privs are NULL
746 * (meaning, in practice, that the default ACLs were there at init time
747 * and is what the current privileges are).
748 *
749 * We always perform this delta on all ACLs and expect that by the time
750 * these are run the initial privileges will be in place, even in a binary
751 * upgrade situation (see below).
752 *
753 * Finally, the order in which privileges are in the ACL string (the order
754 * they been GRANT'd in, which the backend maintains) must be preserved to
755 * ensure that GRANTs WITH GRANT OPTION and subsequent GRANTs based on
756 * those are dumped in the correct order.
757 */
758 printfPQExpBuffer(acl_subquery,
759 "(SELECT pg_catalog.array_agg(acl ORDER BY row_n) FROM "
760 "(SELECT acl, row_n FROM "
761 "pg_catalog.unnest(coalesce(%s,pg_catalog.acldefault(%s,%s))) "
762 "WITH ORDINALITY AS perm(acl,row_n) "
763 "WHERE NOT EXISTS ( "
764 "SELECT 1 FROM "
765 "pg_catalog.unnest(coalesce(pip.initprivs,pg_catalog.acldefault(%s,%s))) "
766 "AS init(init_acl) WHERE acl = init_acl)) as foo)",
767 acl_column,
768 obj_kind,
769 acl_owner,
770 obj_kind,
771 acl_owner);
772
773 printfPQExpBuffer(racl_subquery,
774 "(SELECT pg_catalog.array_agg(acl ORDER BY row_n) FROM "
775 "(SELECT acl, row_n FROM "
776 "pg_catalog.unnest(coalesce(pip.initprivs,pg_catalog.acldefault(%s,%s))) "
777 "WITH ORDINALITY AS initp(acl,row_n) "
778 "WHERE NOT EXISTS ( "
779 "SELECT 1 FROM "
780 "pg_catalog.unnest(coalesce(%s,pg_catalog.acldefault(%s,%s))) "
781 "AS permp(orig_acl) WHERE acl = orig_acl)) as foo)",
782 obj_kind,
783 acl_owner,
784 acl_column,
785 obj_kind,
786 acl_owner);
787
788 /*
789 * In binary upgrade mode we don't run the extension script but instead
790 * dump out the objects independently and then recreate them. To preserve
791 * the initial privileges which were set on extension objects, we need to
792 * grab the set of GRANT and REVOKE commands necessary to get from the
793 * default privileges of an object to the initial privileges as recorded
794 * in pg_init_privs.
795 *
796 * These will then be run ahead of the regular ACL commands, which were
797 * calculated using the queries above, inside of a block which sets a flag
798 * to indicate that the backend should record the results of these GRANT
799 * and REVOKE statements into pg_init_privs. This is how we preserve the
800 * contents of that catalog across binary upgrades.
801 */
802 if (binary_upgrade)
803 {
804 printfPQExpBuffer(init_acl_subquery,
805 "CASE WHEN privtype = 'e' THEN "
806 "(SELECT pg_catalog.array_agg(acl ORDER BY row_n) FROM "
807 "(SELECT acl, row_n FROM pg_catalog.unnest(pip.initprivs) "
808 "WITH ORDINALITY AS initp(acl,row_n) "
809 "WHERE NOT EXISTS ( "
810 "SELECT 1 FROM "
811 "pg_catalog.unnest(pg_catalog.acldefault(%s,%s)) "
812 "AS privm(orig_acl) WHERE acl = orig_acl)) as foo) END",
813 obj_kind,
814 acl_owner);
815
816 printfPQExpBuffer(init_racl_subquery,
817 "CASE WHEN privtype = 'e' THEN "
818 "(SELECT pg_catalog.array_agg(acl) FROM "
819 "(SELECT acl, row_n FROM "
820 "pg_catalog.unnest(pg_catalog.acldefault(%s,%s)) "
821 "WITH ORDINALITY AS privp(acl,row_n) "
822 "WHERE NOT EXISTS ( "
823 "SELECT 1 FROM pg_catalog.unnest(pip.initprivs) "
824 "AS initp(init_acl) WHERE acl = init_acl)) as foo) END",
825 obj_kind,
826 acl_owner);
827 }
828 else
829 {
830 printfPQExpBuffer(init_acl_subquery, "NULL");
831 printfPQExpBuffer(init_racl_subquery, "NULL");
832 }
833 }
834
835 /*
836 * Detect whether the given GUC variable is of GUC_LIST_QUOTE type.
837 *
838 * It'd be better if we could inquire this directly from the backend; but even
839 * if there were a function for that, it could only tell us about variables
840 * currently known to guc.c, so that it'd be unsafe for extensions to declare
841 * GUC_LIST_QUOTE variables anyway. Lacking a solution for that, it doesn't
842 * seem worth the work to do more than have this list, which must be kept in
843 * sync with the variables actually marked GUC_LIST_QUOTE in guc.c.
844 */
845 bool
variable_is_guc_list_quote(const char * name)846 variable_is_guc_list_quote(const char *name)
847 {
848 if (pg_strcasecmp(name, "temp_tablespaces") == 0 ||
849 pg_strcasecmp(name, "session_preload_libraries") == 0 ||
850 pg_strcasecmp(name, "shared_preload_libraries") == 0 ||
851 pg_strcasecmp(name, "local_preload_libraries") == 0 ||
852 pg_strcasecmp(name, "search_path") == 0)
853 return true;
854 else
855 return false;
856 }
857
858 /*
859 * SplitGUCList --- parse a string containing identifiers or file names
860 *
861 * This is used to split the value of a GUC_LIST_QUOTE GUC variable, without
862 * presuming whether the elements will be taken as identifiers or file names.
863 * See comparable code in src/backend/utils/adt/varlena.c.
864 *
865 * Inputs:
866 * rawstring: the input string; must be overwritable! On return, it's
867 * been modified to contain the separated identifiers.
868 * separator: the separator punctuation expected between identifiers
869 * (typically '.' or ','). Whitespace may also appear around
870 * identifiers.
871 * Outputs:
872 * namelist: receives a malloc'd, null-terminated array of pointers to
873 * identifiers within rawstring. Caller should free this
874 * even on error return.
875 *
876 * Returns true if okay, false if there is a syntax error in the string.
877 */
878 bool
SplitGUCList(char * rawstring,char separator,char *** namelist)879 SplitGUCList(char *rawstring, char separator,
880 char ***namelist)
881 {
882 char *nextp = rawstring;
883 bool done = false;
884 char **nextptr;
885
886 /*
887 * Since we disallow empty identifiers, this is a conservative
888 * overestimate of the number of pointers we could need. Allow one for
889 * list terminator.
890 */
891 *namelist = nextptr = (char **)
892 pg_malloc((strlen(rawstring) / 2 + 2) * sizeof(char *));
893 *nextptr = NULL;
894
895 while (isspace((unsigned char) *nextp))
896 nextp++; /* skip leading whitespace */
897
898 if (*nextp == '\0')
899 return true; /* allow empty string */
900
901 /* At the top of the loop, we are at start of a new identifier. */
902 do
903 {
904 char *curname;
905 char *endp;
906
907 if (*nextp == '"')
908 {
909 /* Quoted name --- collapse quote-quote pairs */
910 curname = nextp + 1;
911 for (;;)
912 {
913 endp = strchr(nextp + 1, '"');
914 if (endp == NULL)
915 return false; /* mismatched quotes */
916 if (endp[1] != '"')
917 break; /* found end of quoted name */
918 /* Collapse adjacent quotes into one quote, and look again */
919 memmove(endp, endp + 1, strlen(endp));
920 nextp = endp;
921 }
922 /* endp now points at the terminating quote */
923 nextp = endp + 1;
924 }
925 else
926 {
927 /* Unquoted name --- extends to separator or whitespace */
928 curname = nextp;
929 while (*nextp && *nextp != separator &&
930 !isspace((unsigned char) *nextp))
931 nextp++;
932 endp = nextp;
933 if (curname == nextp)
934 return false; /* empty unquoted name not allowed */
935 }
936
937 while (isspace((unsigned char) *nextp))
938 nextp++; /* skip trailing whitespace */
939
940 if (*nextp == separator)
941 {
942 nextp++;
943 while (isspace((unsigned char) *nextp))
944 nextp++; /* skip leading whitespace for next */
945 /* we expect another name, so done remains false */
946 }
947 else if (*nextp == '\0')
948 done = true;
949 else
950 return false; /* invalid syntax */
951
952 /* Now safe to overwrite separator with a null */
953 *endp = '\0';
954
955 /*
956 * Finished isolating current name --- add it to output array
957 */
958 *nextptr++ = curname;
959
960 /* Loop back if we didn't reach end of string */
961 } while (!done);
962
963 *nextptr = NULL;
964 return true;
965 }
966