1/*
2 * function.c
3 *
4 * server-side function support
5 *
6 * Copyright (c) 2010-2019, PostgreSQL Global Development Group
7 * src/bin/pg_upgrade/function.c
8 */
9
10#include "postgres_fe.h"
11
12#include "pg_upgrade.h"
13
14#include "access/transam.h"
15#include "catalog/pg_language_d.h"
16
17
18/*
19 * qsort comparator for pointers to library names
20 *
21 * We sort first by name length, then alphabetically for names of the
22 * same length, then database array index. This is to ensure that, eg,
23 * "hstore_plpython" sorts after both "hstore" and "plpython"; otherwise
24 * transform modules will probably fail their LOAD tests. (The backend
25 * ought to cope with that consideration, but it doesn't yet, and even
26 * when it does it'll still be a good idea to have a predictable order of
27 * probing here.)
28 */
29static int
30library_name_compare(const void *p1, const void *p2)
31{
32 const char *str1 = ((const LibraryInfo *) p1)->name;
33 const char *str2 = ((const LibraryInfo *) p2)->name;
34 int slen1 = strlen(str1);
35 int slen2 = strlen(str2);
36 int cmp = strcmp(str1, str2);
37
38 if (slen1 != slen2)
39 return slen1 - slen2;
40 if (cmp != 0)
41 return cmp;
42 else
43 return ((const LibraryInfo *) p1)->dbnum -
44 ((const LibraryInfo *) p2)->dbnum;
45}
46
47
48/*
49 * get_loadable_libraries()
50 *
51 * Fetch the names of all old libraries containing C-language functions.
52 * We will later check that they all exist in the new installation.
53 */
54void
55get_loadable_libraries(void)
56{
57 PGresult **ress;
58 int totaltups;
59 int dbnum;
60 bool found_public_plpython_handler = false;
61
62 ress = (PGresult **) pg_malloc(old_cluster.dbarr.ndbs * sizeof(PGresult *));
63 totaltups = 0;
64
65 /* Fetch all library names, removing duplicates within each DB */
66 for (dbnum = 0; dbnum < old_cluster.dbarr.ndbs; dbnum++)
67 {
68 DbInfo *active_db = &old_cluster.dbarr.dbs[dbnum];
69 PGconn *conn = connectToServer(&old_cluster, active_db->db_name);
70
71 /*
72 * Fetch all libraries containing non-built-in C functions in this DB.
73 */
74 ress[dbnum] = executeQueryOrDie(conn,
75 "SELECT DISTINCT probin "
76 "FROM pg_catalog.pg_proc "
77 "WHERE prolang = %u AND "
78 "probin IS NOT NULL AND "
79 "oid >= %u;",
80 ClanguageId,
81 FirstNormalObjectId);
82 totaltups += PQntuples(ress[dbnum]);
83
84 /*
85 * Systems that install plpython before 8.1 have
86 * plpython_call_handler() defined in the "public" schema, causing
87 * pg_dump to dump it. However that function still references
88 * "plpython" (no "2"), so it throws an error on restore. This code
89 * checks for the problem function, reports affected databases to the
90 * user and explains how to remove them. 8.1 git commit:
91 * e0dedd0559f005d60c69c9772163e69c204bac69
92 * http://archives.postgresql.org/pgsql-hackers/2012-03/msg01101.php
93 * http://archives.postgresql.org/pgsql-bugs/2012-05/msg00206.php
94 */
95 if (GET_MAJOR_VERSION(old_cluster.major_version) < 901)
96 {
97 PGresult *res;
98
99 res = executeQueryOrDie(conn,
100 "SELECT 1 "
101 "FROM pg_catalog.pg_proc p "
102 " JOIN pg_catalog.pg_namespace n "
103 " ON pronamespace = n.oid "
104 "WHERE proname = 'plpython_call_handler' AND "
105 "nspname = 'public' AND "
106 "prolang = %u AND "
107 "probin = '$libdir/plpython' AND "
108 "p.oid >= %u;",
109 ClanguageId,
110 FirstNormalObjectId);
111 if (PQntuples(res) > 0)
112 {
113 if (!found_public_plpython_handler)
114 {
115 pg_log(PG_WARNING,
116 "\nThe old cluster has a \"plpython_call_handler\" function defined\n"
117 "in the \"public\" schema which is a duplicate of the one defined\n"
118 "in the \"pg_catalog\" schema. You can confirm this by executing\n"
119 "in psql:\n"
120 "\n"
121 " \\df *.plpython_call_handler\n"
122 "\n"
123 "The \"public\" schema version of this function was created by a\n"
124 "pre-8.1 install of plpython, and must be removed for pg_upgrade\n"
125 "to complete because it references a now-obsolete \"plpython\"\n"
126 "shared object file. You can remove the \"public\" schema version\n"
127 "of this function by running the following command:\n"
128 "\n"
129 " DROP FUNCTION public.plpython_call_handler()\n"
130 "\n"
131 "in each affected database:\n"
132 "\n");
133 }
134 pg_log(PG_WARNING, " %s\n", active_db->db_name);
135 found_public_plpython_handler = true;
136 }
137 PQclear(res);
138 }
139
140 PQfinish(conn);
141 }
142
143 if (found_public_plpython_handler)
144 pg_fatal("Remove the problem functions from the old cluster to continue.\n");
145
146 os_info.libraries = (LibraryInfo *) pg_malloc(totaltups * sizeof(LibraryInfo));
147 totaltups = 0;
148
149 for (dbnum = 0; dbnum < old_cluster.dbarr.ndbs; dbnum++)
150 {
151 PGresult *res = ress[dbnum];
152 int ntups;
153 int rowno;
154
155 ntups = PQntuples(res);
156 for (rowno = 0; rowno < ntups; rowno++)
157 {
158 char *lib = PQgetvalue(res, rowno, 0);
159
160 os_info.libraries[totaltups].name = pg_strdup(lib);
161 os_info.libraries[totaltups].dbnum = dbnum;
162
163 totaltups++;
164 }
165 PQclear(res);
166 }
167
168 pg_free(ress);
169
170 os_info.num_libraries = totaltups;
171}
172
173
174/*
175 * check_loadable_libraries()
176 *
177 * Check that the new cluster contains all required libraries.
178 * We do this by actually trying to LOAD each one, thereby testing
179 * compatibility as well as presence.
180 */
181void
182check_loadable_libraries(void)
183{
184 PGconn *conn = connectToServer(&new_cluster, "template1");
185 int libnum;
186 int was_load_failure = false;
187 FILE *script = NULL;
188 bool found = false;
189 char output_path[MAXPGPATH];
190
191 prep_status("Checking for presence of required libraries");
192
193 snprintf(output_path, sizeof(output_path), "loadable_libraries.txt");
194
195 /*
196 * Now we want to sort the library names into order. This avoids multiple
197 * probes of the same library, and ensures that libraries are probed in a
198 * consistent order, which is important for reproducible behavior if one
199 * library depends on another.
200 */
201 qsort((void *) os_info.libraries, os_info.num_libraries,
202 sizeof(LibraryInfo), library_name_compare);
203
204 for (libnum = 0; libnum < os_info.num_libraries; libnum++)
205 {
206 char *lib = os_info.libraries[libnum].name;
207 int llen = strlen(lib);
208 char cmd[7 + 2 * MAXPGPATH + 1];
209 PGresult *res;
210
211 /* Did the library name change? Probe it. */
212 if (libnum == 0 || strcmp(lib, os_info.libraries[libnum - 1].name) != 0)
213 {
214 /*
215 * In Postgres 9.0, Python 3 support was added, and to do that, a
216 * plpython2u language was created with library name plpython2.so
217 * as a symbolic link to plpython.so. In Postgres 9.1, only the
218 * plpython2.so library was created, and both plpythonu and
219 * plpython2u pointing to it. For this reason, any reference to
220 * library name "plpython" in an old PG <= 9.1 cluster must look
221 * for "plpython2" in the new cluster.
222 *
223 * For this case, we could check pg_pltemplate, but that only
224 * works for languages, and does not help with function shared
225 * objects, so we just do a general fix.
226 */
227 if (GET_MAJOR_VERSION(old_cluster.major_version) < 901 &&
228 strcmp(lib, "$libdir/plpython") == 0)
229 {
230 lib = "$libdir/plpython2";
231 llen = strlen(lib);
232 }
233
234 strcpy(cmd, "LOAD '");
235 PQescapeStringConn(conn, cmd + strlen(cmd), lib, llen, NULL);
236 strcat(cmd, "'");
237
238 res = PQexec(conn, cmd);
239
240 if (PQresultStatus(res) != PGRES_COMMAND_OK)
241 {
242 found = true;
243 was_load_failure = true;
244
245 if (script == NULL && (script = fopen_priv(output_path, "w")) == NULL)
246 pg_fatal("could not open file \"%s\": %s\n",
247 output_path, strerror(errno));
248 fprintf(script, _("could not load library \"%s\": %s"),
249 lib,
250 PQerrorMessage(conn));
251 }
252 else
253 was_load_failure = false;
254
255 PQclear(res);
256 }
257
258 if (was_load_failure)
259 fprintf(script, _("Database: %s\n"),
260 old_cluster.dbarr.dbs[os_info.libraries[libnum].dbnum].db_name);
261 }
262
263 PQfinish(conn);
264
265 if (found)
266 {
267 fclose(script);
268 pg_log(PG_REPORT, "fatal\n");
269 pg_fatal("Your installation references loadable libraries that are missing from the\n"
270 "new installation. You can add these libraries to the new installation,\n"
271 "or remove the functions using them from the old installation. A list of\n"
272 "problem libraries is in the file:\n"
273 " %s\n\n", output_path);
274 }
275 else
276 check_ok();
277}
278