Fix pg_upgrade to cope with non-default unix_socket_directory scenarios.

When starting either an old or new postmaster, force it to place its Unix
socket in the current directory.  This makes it even harder for accidental
connections to occur during pg_upgrade, and also works around some
scenarios where the default socket location isn't usable.  (For example,
if the default location is something other than "/tmp", it might not exist
during "make check".)

When checking an already-running old postmaster, find out its actual socket
directory location from postmaster.pid, if possible.  This dodges problems
with an old postmaster having a configured location different from the
default built into pg_upgrade's libpq.  We can't find that out if the old
postmaster is pre-9.1, so also document how to cope with such scenarios
manually.

In support of this, centralize handling of the connection-related command
line options passed to pg_upgrade's subsidiary programs, such as pg_dump.
This should make future changes easier.

Bruce Momjian and Tom Lane

1 files changed, 59 insertions, 8 deletions

diff --git a/contrib/pg_upgrade/server.c b/contrib/pg_upgrade/server.c
index 1fb0d6ccceb..11e7e75d78f 100644
--- a/contrib/pg_upgrade/server.c
+++ b/contrib/pg_upgrade/server.c
@@ -46,22 +46,55 @@ connectToServer(ClusterInfo *cluster, const char *db_name)
 /*
  * get_db_conn()
  *
- * get database connection
+ * get database connection, using named database + standard params for cluster
  */
 static PGconn *
 get_db_conn(ClusterInfo *cluster, const char *db_name)
 {
-	char		conn_opts[MAXPGPATH];
+	char		conn_opts[2 * NAMEDATALEN + MAXPGPATH + 100];
 
-	snprintf(conn_opts, sizeof(conn_opts),
-			 "dbname = '%s' user = '%s' port = %d", db_name, os_info.user,
-			 cluster->port);
+	if (cluster->sockdir)
+		snprintf(conn_opts, sizeof(conn_opts),
+				 "dbname = '%s' user = '%s' host = '%s' port = %d",
+				 db_name, os_info.user, cluster->sockdir, cluster->port);
+	else
+		snprintf(conn_opts, sizeof(conn_opts),
+				 "dbname = '%s' user = '%s' port = %d",
+				 db_name, os_info.user, cluster->port);
 
 	return PQconnectdb(conn_opts);
 }
 
 
 /*
+ * cluster_conn_opts()
+ *
+ * Return standard command-line options for connecting to this cluster when
+ * using psql, pg_dump, etc.  Ideally this would match what get_db_conn()
+ * sets, but the utilities we need aren't very consistent about the treatment
+ * of database name options, so we leave that out.
+ *
+ * Note result is in static storage, so use it right away.
+ */
+char *
+cluster_conn_opts(ClusterInfo *cluster)
+{
+	static char	conn_opts[MAXPGPATH + NAMEDATALEN + 100];
+
+	if (cluster->sockdir)
+		snprintf(conn_opts, sizeof(conn_opts),
+				 "--host \"%s\" --port %d --username \"%s\"",
+				 cluster->sockdir, cluster->port, os_info.user);
+	else
+		snprintf(conn_opts, sizeof(conn_opts),
+				 "--port %d --username \"%s\"",
+				 cluster->port, os_info.user);
+
+	return conn_opts;
+}
+
+
+/*
  * executeQueryOrDie()
  *
  *	Formats a query string from the given arguments and executes the
@@ -140,10 +173,11 @@ stop_postmaster_atexit(void)
 void
 start_postmaster(ClusterInfo *cluster)
 {
-	char		cmd[MAXPGPATH];
+	char		cmd[MAXPGPATH * 4 + 1000];
 	PGconn	   *conn;
 	bool		exit_hook_registered = false;
 	bool		pg_ctl_return = false;
+	char		socket_string[MAXPGPATH + 200];
 
 	if (!exit_hook_registered)
 	{
@@ -151,6 +185,23 @@ start_postmaster(ClusterInfo *cluster)
 		exit_hook_registered = true;
 	}
 
+	socket_string[0] = '\0';
+
+#ifdef HAVE_UNIX_SOCKETS
+	/* prevent TCP/IP connections, restrict socket access */
+	strcat(socket_string,
+		   " -c listen_addresses='' -c unix_socket_permissions=0700");
+
+	/* Have a sockdir?  Tell the postmaster. */
+	if (cluster->sockdir)
+		snprintf(socket_string + strlen(socket_string),
+				 sizeof(socket_string) - strlen(socket_string),
+				 " -c %s='%s'",
+				 (GET_MAJOR_VERSION(cluster->major_version) < 903) ?
+				 "unix_socket_directory" : "unix_socket_directories",
+				 cluster->sockdir);
+#endif
+
 	/*
 	 * Using autovacuum=off disables cleanup vacuum and analyze, but freeze
 	 * vacuums can still happen, so we set autovacuum_freeze_max_age to its
@@ -159,12 +210,12 @@ start_postmaster(ClusterInfo *cluster)
 	 * not touch them.
 	 */
 	snprintf(cmd, sizeof(cmd),
-			 "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" -o \"-p %d %s %s\" start",
+			 "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" -o \"-p %d %s %s%s\" start",
 		  cluster->bindir, SERVER_LOG_FILE, cluster->pgconfig, cluster->port,
 			 (cluster->controldata.cat_ver >=
 			  BINARY_UPGRADE_SERVER_FLAG_CAT_VER) ? "-b" :
 			 "-c autovacuum=off -c autovacuum_freeze_max_age=2000000000",
-			 cluster->pgopts ? cluster->pgopts : "");
+			 cluster->pgopts ? cluster->pgopts : "", socket_string);
 
 	/*
 	 * Don't throw an error right away, let connecting throw the error because