Line data Source code
1 : /*
2 : * server.c
3 : *
4 : * database server functions
5 : *
6 : * Copyright (c) 2010-2026, PostgreSQL Global Development Group
7 : * src/bin/pg_upgrade/server.c
8 : */
9 :
10 : #include "postgres_fe.h"
11 :
12 : #include "common/connect.h"
13 : #include "fe_utils/string_utils.h"
14 : #include "libpq/pqcomm.h"
15 : #include "pg_upgrade.h"
16 :
17 : static PGconn *get_db_conn(ClusterInfo *cluster, const char *db_name);
18 :
19 :
20 : /*
21 : * connectToServer()
22 : *
23 : * Connects to the desired database on the designated server.
24 : * If the connection attempt fails, this function logs an error
25 : * message and calls exit() to kill the program.
26 : */
27 : PGconn *
28 0 : connectToServer(ClusterInfo *cluster, const char *db_name)
29 : {
30 0 : PGconn *conn = get_db_conn(cluster, db_name);
31 :
32 0 : if (conn == NULL || PQstatus(conn) != CONNECTION_OK)
33 : {
34 0 : pg_log(PG_REPORT, "%s", PQerrorMessage(conn));
35 :
36 0 : if (conn)
37 0 : PQfinish(conn);
38 :
39 0 : printf(_("Failure, exiting\n"));
40 0 : exit(1);
41 : }
42 :
43 0 : PQclear(executeQueryOrDie(conn, ALWAYS_SECURE_SEARCH_PATH_SQL));
44 :
45 0 : return conn;
46 0 : }
47 :
48 :
49 : /*
50 : * get_db_conn()
51 : *
52 : * get database connection, using named database + standard params for cluster
53 : *
54 : * Caller must check for connection failure!
55 : */
56 : static PGconn *
57 0 : get_db_conn(ClusterInfo *cluster, const char *db_name)
58 : {
59 0 : PQExpBufferData conn_opts;
60 0 : PGconn *conn;
61 :
62 : /* Build connection string with proper quoting */
63 0 : initPQExpBuffer(&conn_opts);
64 0 : appendPQExpBufferStr(&conn_opts, "dbname=");
65 0 : appendConnStrVal(&conn_opts, db_name);
66 0 : appendPQExpBufferStr(&conn_opts, " user=");
67 0 : appendConnStrVal(&conn_opts, os_info.user);
68 0 : appendPQExpBuffer(&conn_opts, " port=%d", cluster->port);
69 0 : if (cluster->sockdir)
70 : {
71 0 : appendPQExpBufferStr(&conn_opts, " host=");
72 0 : appendConnStrVal(&conn_opts, cluster->sockdir);
73 0 : }
74 :
75 0 : conn = PQconnectdb(conn_opts.data);
76 0 : termPQExpBuffer(&conn_opts);
77 0 : return conn;
78 0 : }
79 :
80 :
81 : /*
82 : * cluster_conn_opts()
83 : *
84 : * Return standard command-line options for connecting to this cluster when
85 : * using psql, pg_dump, etc. Ideally this would match what get_db_conn()
86 : * sets, but the utilities we need aren't very consistent about the treatment
87 : * of database name options, so we leave that out.
88 : *
89 : * Result is valid until the next call to this function.
90 : */
91 : char *
92 0 : cluster_conn_opts(ClusterInfo *cluster)
93 : {
94 : static PQExpBuffer buf;
95 :
96 0 : if (buf == NULL)
97 0 : buf = createPQExpBuffer();
98 : else
99 0 : resetPQExpBuffer(buf);
100 :
101 0 : if (cluster->sockdir)
102 : {
103 0 : appendPQExpBufferStr(buf, "--host ");
104 0 : appendShellString(buf, cluster->sockdir);
105 0 : appendPQExpBufferChar(buf, ' ');
106 0 : }
107 0 : appendPQExpBuffer(buf, "--port %d --username ", cluster->port);
108 0 : appendShellString(buf, os_info.user);
109 :
110 0 : return buf->data;
111 : }
112 :
113 :
114 : /*
115 : * executeQueryOrDie()
116 : *
117 : * Formats a query string from the given arguments and executes the
118 : * resulting query. If the query fails, this function logs an error
119 : * message and calls exit() to kill the program.
120 : */
121 : PGresult *
122 0 : executeQueryOrDie(PGconn *conn, const char *fmt,...)
123 : {
124 : static char query[QUERY_ALLOC];
125 0 : va_list args;
126 0 : PGresult *result;
127 0 : ExecStatusType status;
128 :
129 0 : va_start(args, fmt);
130 0 : vsnprintf(query, sizeof(query), fmt, args);
131 0 : va_end(args);
132 :
133 0 : pg_log(PG_VERBOSE, "executing: %s", query);
134 0 : result = PQexec(conn, query);
135 0 : status = PQresultStatus(result);
136 :
137 0 : if ((status != PGRES_TUPLES_OK) && (status != PGRES_COMMAND_OK))
138 : {
139 0 : pg_log(PG_REPORT, "SQL command failed\n%s\n%s", query,
140 0 : PQerrorMessage(conn));
141 0 : PQclear(result);
142 0 : PQfinish(conn);
143 0 : printf(_("Failure, exiting\n"));
144 0 : exit(1);
145 : }
146 : else
147 0 : return result;
148 0 : }
149 :
150 :
151 : static void
152 0 : stop_postmaster_atexit(void)
153 : {
154 0 : stop_postmaster(true);
155 0 : }
156 :
157 :
158 : bool
159 0 : start_postmaster(ClusterInfo *cluster, bool report_and_exit_on_error)
160 : {
161 0 : char cmd[MAXPGPATH * 4 + 1000];
162 0 : PGconn *conn;
163 0 : bool pg_ctl_return = false;
164 0 : char socket_string[MAXPGPATH + 200];
165 0 : PQExpBufferData pgoptions;
166 :
167 : static bool exit_hook_registered = false;
168 :
169 0 : if (!exit_hook_registered)
170 : {
171 0 : atexit(stop_postmaster_atexit);
172 0 : exit_hook_registered = true;
173 0 : }
174 :
175 0 : socket_string[0] = '\0';
176 :
177 : #if !defined(WIN32)
178 : /* prevent TCP/IP connections, restrict socket access */
179 0 : strcat(socket_string,
180 : " -c listen_addresses='' -c unix_socket_permissions=0700");
181 :
182 : /* Have a sockdir? Tell the postmaster. */
183 0 : if (cluster->sockdir)
184 0 : snprintf(socket_string + strlen(socket_string),
185 0 : sizeof(socket_string) - strlen(socket_string),
186 : " -c %s='%s'",
187 0 : (GET_MAJOR_VERSION(cluster->major_version) <= 902) ?
188 : "unix_socket_directory" : "unix_socket_directories",
189 0 : cluster->sockdir);
190 : #endif
191 :
192 0 : initPQExpBuffer(&pgoptions);
193 :
194 : /*
195 : * Construct a parameter string which is passed to the server process.
196 : *
197 : * Turn off durability requirements to improve object creation speed, and
198 : * we only modify the new cluster, so only use it there. If there is a
199 : * crash, the new cluster has to be recreated anyway. fsync=off is a big
200 : * win on ext4.
201 : */
202 0 : if (cluster == &new_cluster)
203 0 : appendPQExpBufferStr(&pgoptions, " -c synchronous_commit=off -c fsync=off -c full_page_writes=off");
204 :
205 : /*
206 : * Use -b to disable autovacuum and logical replication launcher
207 : * (effective in PG17 or later for the latter).
208 : */
209 0 : snprintf(cmd, sizeof(cmd),
210 : "\"%s/pg_ctl\" -w -l \"%s/%s\" -D \"%s\" -o \"-p %d -b%s %s%s\" start",
211 0 : cluster->bindir,
212 0 : log_opts.logdir,
213 0 : SERVER_LOG_FILE, cluster->pgconfig, cluster->port,
214 0 : pgoptions.data,
215 0 : cluster->pgopts ? cluster->pgopts : "", socket_string);
216 :
217 0 : termPQExpBuffer(&pgoptions);
218 :
219 : /*
220 : * Don't throw an error right away, let connecting throw the error because
221 : * it might supply a reason for the failure.
222 : */
223 0 : pg_ctl_return = exec_prog(SERVER_START_LOG_FILE,
224 : /* pass both file names if they differ */
225 : (strcmp(SERVER_LOG_FILE,
226 : SERVER_START_LOG_FILE) != 0) ?
227 : SERVER_LOG_FILE : NULL,
228 0 : report_and_exit_on_error, false,
229 0 : "%s", cmd);
230 :
231 : /* Did it fail and we are just testing if the server could be started? */
232 0 : if (!pg_ctl_return && !report_and_exit_on_error)
233 0 : return false;
234 :
235 : /*
236 : * We set this here to make sure atexit() shuts down the server, but only
237 : * if we started the server successfully. We do it before checking for
238 : * connectivity in case the server started but there is a connectivity
239 : * failure. If pg_ctl did not return success, we will exit below.
240 : *
241 : * Pre-9.1 servers do not have PQping(), so we could be leaving the server
242 : * running if authentication was misconfigured, so someday we might went
243 : * to be more aggressive about doing server shutdowns even if pg_ctl
244 : * fails, but now (2013-08-14) it seems prudent to be cautious. We don't
245 : * want to shutdown a server that might have been accidentally started
246 : * during the upgrade.
247 : */
248 0 : if (pg_ctl_return)
249 0 : os_info.running_cluster = cluster;
250 :
251 : /*
252 : * pg_ctl -w might have failed because the server couldn't be started, or
253 : * there might have been a connection problem in _checking_ if the server
254 : * has started. Therefore, even if pg_ctl failed, we continue and test
255 : * for connectivity in case we get a connection reason for the failure.
256 : */
257 0 : if ((conn = get_db_conn(cluster, "template1")) == NULL ||
258 0 : PQstatus(conn) != CONNECTION_OK)
259 : {
260 0 : pg_log(PG_REPORT, "\n%s", PQerrorMessage(conn));
261 0 : if (conn)
262 0 : PQfinish(conn);
263 0 : if (cluster == &old_cluster)
264 0 : pg_fatal("could not connect to source postmaster started with the command:\n"
265 : "%s",
266 0 : cmd);
267 : else
268 0 : pg_fatal("could not connect to target postmaster started with the command:\n"
269 : "%s",
270 0 : cmd);
271 : }
272 0 : PQfinish(conn);
273 :
274 : /*
275 : * If pg_ctl failed, and the connection didn't fail, and
276 : * report_and_exit_on_error is enabled, fail now. This could happen if
277 : * the server was already running.
278 : */
279 0 : if (!pg_ctl_return)
280 : {
281 0 : if (cluster == &old_cluster)
282 0 : pg_fatal("pg_ctl failed to start the source server, or connection failed");
283 : else
284 0 : pg_fatal("pg_ctl failed to start the target server, or connection failed");
285 : }
286 :
287 0 : return true;
288 0 : }
289 :
290 :
291 : void
292 0 : stop_postmaster(bool in_atexit)
293 : {
294 0 : ClusterInfo *cluster;
295 :
296 0 : if (os_info.running_cluster == &old_cluster)
297 0 : cluster = &old_cluster;
298 0 : else if (os_info.running_cluster == &new_cluster)
299 0 : cluster = &new_cluster;
300 : else
301 0 : return; /* no cluster running */
302 :
303 0 : exec_prog(SERVER_STOP_LOG_FILE, NULL, !in_atexit, !in_atexit,
304 : "\"%s/pg_ctl\" -w -D \"%s\" -o \"%s\" %s stop",
305 0 : cluster->bindir, cluster->pgconfig,
306 0 : cluster->pgopts ? cluster->pgopts : "",
307 0 : in_atexit ? "-m fast" : "-m smart");
308 :
309 0 : os_info.running_cluster = NULL;
310 0 : }
311 :
312 :
313 : /*
314 : * check_pghost_envvar()
315 : *
316 : * Tests that PGHOST does not point to a non-local server
317 : */
318 : void
319 0 : check_pghost_envvar(void)
320 : {
321 0 : PQconninfoOption *option;
322 0 : PQconninfoOption *start;
323 :
324 : /* Get valid libpq env vars from the PQconndefaults function */
325 :
326 0 : start = PQconndefaults();
327 :
328 0 : if (!start)
329 0 : pg_fatal("out of memory");
330 :
331 0 : for (option = start; option->keyword != NULL; option++)
332 : {
333 0 : if (option->envvar && (strcmp(option->envvar, "PGHOST") == 0 ||
334 0 : strcmp(option->envvar, "PGHOSTADDR") == 0))
335 : {
336 0 : const char *value = getenv(option->envvar);
337 :
338 0 : if (value && strlen(value) > 0 &&
339 : /* check for 'local' host values */
340 0 : (strcmp(value, "localhost") != 0 && strcmp(value, "127.0.0.1") != 0 &&
341 0 : strcmp(value, "::1") != 0 && !is_unixsock_path(value)))
342 0 : pg_fatal("libpq environment variable %s has a non-local server value: %s",
343 0 : option->envvar, value);
344 0 : }
345 0 : }
346 :
347 : /* Free the memory that libpq allocated on our behalf */
348 0 : PQconninfoFree(start);
349 0 : }
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