PostgreSQL Source Code  git master
server.c
Go to the documentation of this file.
1 /*
2  * server.c
3  *
4  * database server functions
5  *
6  * Copyright (c) 2010-2021, 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 "pg_upgrade.h"
15 
16 static PGconn *get_db_conn(ClusterInfo *cluster, const char *db_name);
17 
18 
19 /*
20  * connectToServer()
21  *
22  * Connects to the desired database on the designated server.
23  * If the connection attempt fails, this function logs an error
24  * message and calls exit() to kill the program.
25  */
26 PGconn *
27 connectToServer(ClusterInfo *cluster, const char *db_name)
28 {
29  PGconn *conn = get_db_conn(cluster, db_name);
30 
31  if (conn == NULL || PQstatus(conn) != CONNECTION_OK)
32  {
33  pg_log(PG_REPORT, "%s", PQerrorMessage(conn));
34 
35  if (conn)
36  PQfinish(conn);
37 
38  printf(_("Failure, exiting\n"));
39  exit(1);
40  }
41 
43 
44  return conn;
45 }
46 
47 
48 /*
49  * get_db_conn()
50  *
51  * get database connection, using named database + standard params for cluster
52  *
53  * Caller must check for connection failure!
54  */
55 static PGconn *
56 get_db_conn(ClusterInfo *cluster, const char *db_name)
57 {
58  PQExpBufferData conn_opts;
59  PGconn *conn;
60 
61  /* Build connection string with proper quoting */
62  initPQExpBuffer(&conn_opts);
63  appendPQExpBufferStr(&conn_opts, "dbname=");
64  appendConnStrVal(&conn_opts, db_name);
65  appendPQExpBufferStr(&conn_opts, " user=");
66  appendConnStrVal(&conn_opts, os_info.user);
67  appendPQExpBuffer(&conn_opts, " port=%d", cluster->port);
68  if (cluster->sockdir)
69  {
70  appendPQExpBufferStr(&conn_opts, " host=");
71  appendConnStrVal(&conn_opts, cluster->sockdir);
72  }
73 
74  conn = PQconnectdb(conn_opts.data);
75  termPQExpBuffer(&conn_opts);
76  return conn;
77 }
78 
79 
80 /*
81  * cluster_conn_opts()
82  *
83  * Return standard command-line options for connecting to this cluster when
84  * using psql, pg_dump, etc. Ideally this would match what get_db_conn()
85  * sets, but the utilities we need aren't very consistent about the treatment
86  * of database name options, so we leave that out.
87  *
88  * Result is valid until the next call to this function.
89  */
90 char *
92 {
93  static PQExpBuffer buf;
94 
95  if (buf == NULL)
96  buf = createPQExpBuffer();
97  else
98  resetPQExpBuffer(buf);
99 
100  if (cluster->sockdir)
101  {
102  appendPQExpBufferStr(buf, "--host ");
103  appendShellString(buf, cluster->sockdir);
104  appendPQExpBufferChar(buf, ' ');
105  }
106  appendPQExpBuffer(buf, "--port %d --username ", cluster->port);
108 
109  return buf->data;
110 }
111 
112 
113 /*
114  * executeQueryOrDie()
115  *
116  * Formats a query string from the given arguments and executes the
117  * resulting query. If the query fails, this function logs an error
118  * message and calls exit() to kill the program.
119  */
120 PGresult *
121 executeQueryOrDie(PGconn *conn, const char *fmt,...)
122 {
123  static char query[QUERY_ALLOC];
124  va_list args;
125  PGresult *result;
127 
128  va_start(args, fmt);
129  vsnprintf(query, sizeof(query), fmt, args);
130  va_end(args);
131 
132  pg_log(PG_VERBOSE, "executing: %s\n", query);
133  result = PQexec(conn, query);
134  status = PQresultStatus(result);
135 
136  if ((status != PGRES_TUPLES_OK) && (status != PGRES_COMMAND_OK))
137  {
138  pg_log(PG_REPORT, "SQL command failed\n%s\n%s", query,
139  PQerrorMessage(conn));
140  PQclear(result);
141  PQfinish(conn);
142  printf(_("Failure, exiting\n"));
143  exit(1);
144  }
145  else
146  return result;
147 }
148 
149 
150 /*
151  * get_major_server_version()
152  *
153  * gets the version (in unsigned int form) for the given datadir. Assumes
154  * that datadir is an absolute path to a valid pgdata directory. The version
155  * is retrieved by reading the PG_VERSION file.
156  */
157 uint32
159 {
160  FILE *version_fd;
161  char ver_filename[MAXPGPATH];
162  int v1 = 0,
163  v2 = 0;
164 
165  snprintf(ver_filename, sizeof(ver_filename), "%s/PG_VERSION",
166  cluster->pgdata);
167  if ((version_fd = fopen(ver_filename, "r")) == NULL)
168  pg_fatal("could not open version file \"%s\": %m\n", ver_filename);
169 
170  if (fscanf(version_fd, "%63s", cluster->major_version_str) == 0 ||
171  sscanf(cluster->major_version_str, "%d.%d", &v1, &v2) < 1)
172  pg_fatal("could not parse version file \"%s\"\n", ver_filename);
173 
174  fclose(version_fd);
175 
176  if (v1 < 10)
177  {
178  /* old style, e.g. 9.6.1 */
179  return v1 * 10000 + v2 * 100;
180  }
181  else
182  {
183  /* new style, e.g. 10.1 */
184  return v1 * 10000;
185  }
186 }
187 
188 
189 static void
191 {
192  stop_postmaster(true);
193 }
194 
195 
196 bool
197 start_postmaster(ClusterInfo *cluster, bool report_and_exit_on_error)
198 {
199  char cmd[MAXPGPATH * 4 + 1000];
200  PGconn *conn;
201  bool pg_ctl_return = false;
202  char socket_string[MAXPGPATH + 200];
203 
204  static bool exit_hook_registered = false;
205 
206  if (!exit_hook_registered)
207  {
208  atexit(stop_postmaster_atexit);
209  exit_hook_registered = true;
210  }
211 
212  socket_string[0] = '\0';
213 
214 #if defined(HAVE_UNIX_SOCKETS) && !defined(WIN32)
215  /* prevent TCP/IP connections, restrict socket access */
216  strcat(socket_string,
217  " -c listen_addresses='' -c unix_socket_permissions=0700");
218 
219  /* Have a sockdir? Tell the postmaster. */
220  if (cluster->sockdir)
221  snprintf(socket_string + strlen(socket_string),
222  sizeof(socket_string) - strlen(socket_string),
223  " -c %s='%s'",
224  (GET_MAJOR_VERSION(cluster->major_version) <= 902) ?
225  "unix_socket_directory" : "unix_socket_directories",
226  cluster->sockdir);
227 #endif
228 
229  /*
230  * Since PG 9.1, we have used -b to disable autovacuum. For earlier
231  * releases, setting autovacuum=off disables cleanup vacuum and analyze,
232  * but freeze vacuums can still happen, so we set
233  * autovacuum_freeze_max_age to its maximum.
234  * (autovacuum_multixact_freeze_max_age was introduced after 9.1, so there
235  * is no need to set that.) We assume all datfrozenxid and relfrozenxid
236  * values are less than a gap of 2000000000 from the current xid counter,
237  * so autovacuum will not touch them.
238  *
239  * Turn off durability requirements to improve object creation speed, and
240  * we only modify the new cluster, so only use it there. If there is a
241  * crash, the new cluster has to be recreated anyway. fsync=off is a big
242  * win on ext4.
243  *
244  * Force vacuum_defer_cleanup_age to 0 on the new cluster, so that
245  * vacuumdb --freeze actually freezes the tuples.
246  */
247  snprintf(cmd, sizeof(cmd),
248  "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" -o \"-p %d%s%s %s%s\" start",
249  cluster->bindir, SERVER_LOG_FILE, cluster->pgconfig, cluster->port,
250  (cluster->controldata.cat_ver >=
252  " -c autovacuum=off -c autovacuum_freeze_max_age=2000000000",
253  (cluster == &new_cluster) ?
254  " -c synchronous_commit=off -c fsync=off -c full_page_writes=off -c vacuum_defer_cleanup_age=0" : "",
255  cluster->pgopts ? cluster->pgopts : "", socket_string);
256 
257  /*
258  * Don't throw an error right away, let connecting throw the error because
259  * it might supply a reason for the failure.
260  */
261  pg_ctl_return = exec_prog(SERVER_START_LOG_FILE,
262  /* pass both file names if they differ */
263  (strcmp(SERVER_LOG_FILE,
264  SERVER_START_LOG_FILE) != 0) ?
265  SERVER_LOG_FILE : NULL,
266  report_and_exit_on_error, false,
267  "%s", cmd);
268 
269  /* Did it fail and we are just testing if the server could be started? */
270  if (!pg_ctl_return && !report_and_exit_on_error)
271  return false;
272 
273  /*
274  * We set this here to make sure atexit() shuts down the server, but only
275  * if we started the server successfully. We do it before checking for
276  * connectivity in case the server started but there is a connectivity
277  * failure. If pg_ctl did not return success, we will exit below.
278  *
279  * Pre-9.1 servers do not have PQping(), so we could be leaving the server
280  * running if authentication was misconfigured, so someday we might went
281  * to be more aggressive about doing server shutdowns even if pg_ctl
282  * fails, but now (2013-08-14) it seems prudent to be cautious. We don't
283  * want to shutdown a server that might have been accidentally started
284  * during the upgrade.
285  */
286  if (pg_ctl_return)
288 
289  /*
290  * pg_ctl -w might have failed because the server couldn't be started, or
291  * there might have been a connection problem in _checking_ if the server
292  * has started. Therefore, even if pg_ctl failed, we continue and test
293  * for connectivity in case we get a connection reason for the failure.
294  */
295  if ((conn = get_db_conn(cluster, "template1")) == NULL ||
296  PQstatus(conn) != CONNECTION_OK)
297  {
298  pg_log(PG_REPORT, "\n%s", PQerrorMessage(conn));
299  if (conn)
300  PQfinish(conn);
301  if (cluster == &old_cluster)
302  pg_fatal("could not connect to source postmaster started with the command:\n"
303  "%s\n",
304  cmd);
305  else
306  pg_fatal("could not connect to target postmaster started with the command:\n"
307  "%s\n",
308  cmd);
309  }
310  PQfinish(conn);
311 
312  /*
313  * If pg_ctl failed, and the connection didn't fail, and
314  * report_and_exit_on_error is enabled, fail now. This could happen if
315  * the server was already running.
316  */
317  if (!pg_ctl_return)
318  {
319  if (cluster == &old_cluster)
320  pg_fatal("pg_ctl failed to start the source server, or connection failed\n");
321  else
322  pg_fatal("pg_ctl failed to start the target server, or connection failed\n");
323  }
324 
325  return true;
326 }
327 
328 
329 void
330 stop_postmaster(bool in_atexit)
331 {
333 
335  cluster = &old_cluster;
336  else if (os_info.running_cluster == &new_cluster)
337  cluster = &new_cluster;
338  else
339  return; /* no cluster running */
340 
341  exec_prog(SERVER_STOP_LOG_FILE, NULL, !in_atexit, !in_atexit,
342  "\"%s/pg_ctl\" -w -D \"%s\" -o \"%s\" %s stop",
343  cluster->bindir, cluster->pgconfig,
344  cluster->pgopts ? cluster->pgopts : "",
345  in_atexit ? "-m fast" : "-m smart");
346 
347  os_info.running_cluster = NULL;
348 }
349 
350 
351 /*
352  * check_pghost_envvar()
353  *
354  * Tests that PGHOST does not point to a non-local server
355  */
356 void
358 {
360  PQconninfoOption *start;
361 
362  /* Get valid libpq env vars from the PQconndefaults function */
363 
364  start = PQconndefaults();
365 
366  if (!start)
367  pg_fatal("out of memory\n");
368 
369  for (option = start; option->keyword != NULL; option++)
370  {
371  if (option->envvar && (strcmp(option->envvar, "PGHOST") == 0 ||
372  strcmp(option->envvar, "PGHOSTADDR") == 0))
373  {
374  const char *value = getenv(option->envvar);
375 
376  if (value && strlen(value) > 0 &&
377  /* check for 'local' host values */
378  (strcmp(value, "localhost") != 0 && strcmp(value, "127.0.0.1") != 0 &&
379  strcmp(value, "::1") != 0 && value[0] != '/'))
380  pg_fatal("libpq environment variable %s has a non-local server value: %s\n",
381  option->envvar, value);
382  }
383  }
384 
385  /* Free the memory that libpq allocated on our behalf */
386  PQconninfoFree(start);
387 }
char * cluster_conn_opts(ClusterInfo *cluster)
Definition: server.c:91
char * PQerrorMessage(const PGconn *conn)
Definition: fe-connect.c:6735
uint32 major_version
Definition: pg_upgrade.h:267
void cluster(ParseState *pstate, ClusterStmt *stmt, bool isTopLevel)
Definition: cluster.c:103
static struct @142 value
ControlData controldata
Definition: pg_upgrade.h:257
void termPQExpBuffer(PQExpBuffer str)
Definition: pqexpbuffer.c:131
void stop_postmaster(bool in_atexit)
Definition: server.c:330
void appendPQExpBufferStr(PQExpBuffer str, const char *data)
Definition: pqexpbuffer.c:369
#define GET_MAJOR_VERSION(v)
Definition: pg_upgrade.h:23
void appendConnStrVal(PQExpBuffer buf, const char *str)
Definition: string_utils.c:545
#define pg_fatal(...)
Definition: pg_rewind.h:37
void PQfinish(PGconn *conn)
Definition: fe-connect.c:4229
unsigned short port
Definition: pg_upgrade.h:266
#define printf(...)
Definition: port.h:222
ExecStatusType
Definition: libpq-fe.h:83
#define SERVER_STOP_LOG_FILE
Definition: pg_upgrade.h:54
PGconn * connectToServer(ClusterInfo *cluster, const char *db_name)
Definition: server.c:27
ExecStatusType PQresultStatus(const PGresult *res)
Definition: fe-exec.c:3097
char * pgopts
Definition: pg_upgrade.h:263
char major_version_str[64]
Definition: pg_upgrade.h:268
ClusterInfo new_cluster
Definition: pg_upgrade.c:59
char * pgconfig
Definition: pg_upgrade.h:260
bool start_postmaster(ClusterInfo *cluster, bool report_and_exit_on_error)
Definition: server.c:197
PGconn * conn
Definition: streamutil.c:54
#define vsnprintf
Definition: port.h:215
#define MAXPGPATH
void appendPQExpBuffer(PQExpBuffer str, const char *fmt,...)
Definition: pqexpbuffer.c:267
static char * buf
Definition: pg_test_fsync.c:68
void PQconninfoFree(PQconninfoOption *connOptions)
Definition: fe-connect.c:6563
ClusterInfo old_cluster
Definition: pg_upgrade.c:59
unsigned int uint32
Definition: c.h:441
PGresult * executeQueryOrDie(PGconn *conn, const char *fmt,...)
Definition: server.c:121
void check_pghost_envvar(void)
Definition: server.c:357
char * bindir
Definition: pg_upgrade.h:262
uint32 cat_ver
Definition: pg_upgrade.h:202
static void stop_postmaster_atexit(void)
Definition: server.c:190
PQExpBuffer createPQExpBuffer(void)
Definition: pqexpbuffer.c:74
void appendPQExpBufferChar(PQExpBuffer str, char ch)
Definition: pqexpbuffer.c:380
void PQclear(PGresult *res)
Definition: fe-exec.c:680
void appendShellString(PQExpBuffer buf, const char *str)
Definition: string_utils.c:429
#define SERVER_LOG_FILE
Definition: pg_upgrade.h:30
void void pg_log(eLogType type, const char *fmt,...) pg_attribute_printf(2
PQconninfoOption * PQconndefaults(void)
Definition: fe-connect.c:1477
#define ALWAYS_SECURE_SEARCH_PATH_SQL
Definition: connect.h:25
ClusterInfo * running_cluster
Definition: pg_upgrade.h:315
#define SERVER_START_LOG_FILE
Definition: pg_upgrade.h:53
char * pgdata
Definition: pg_upgrade.h:259
char * sockdir
Definition: pg_upgrade.h:265
OSInfo os_info
Definition: pg_upgrade.c:61
PGresult * PQexec(PGconn *conn, const char *query)
Definition: fe-exec.c:2142
#define BINARY_UPGRADE_SERVER_FLAG_CAT_VER
Definition: pg_upgrade.h:94
bool exec_prog(const char *log_file, const char *opt_log_file, bool report_error, bool exit_on_error, const char *fmt,...)
Definition: exec.c:81
void resetPQExpBuffer(PQExpBuffer str)
Definition: pqexpbuffer.c:148
static void static void status(const char *fmt,...) pg_attribute_printf(1
Definition: pg_regress.c:227
ConnStatusType PQstatus(const PGconn *conn)
Definition: fe-connect.c:6682
uint32 get_major_server_version(ClusterInfo *cluster)
Definition: server.c:158
#define snprintf
Definition: port.h:216
char * user
Definition: pg_upgrade.h:309
static PGconn * get_db_conn(ClusterInfo *cluster, const char *db_name)
Definition: server.c:56
#define _(x)
Definition: elog.c:89
#define QUERY_ALLOC
Definition: pg_upgrade.h:19
void initPQExpBuffer(PQExpBuffer str)
Definition: pqexpbuffer.c:92
PGconn * PQconnectdb(const char *conninfo)
Definition: fe-connect.c:718