inted RE: Timeout parameters

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index c1d1b6b2db..7b070263ff 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1249,6 +1249,18 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
       </listitem>
      </varlistentry>
 
+     <varlistentry id="socket_timeout" xreflabel="socket_timeout">
+      <term><literal>socket_timeout</literal></term>
+      <listitem>
+       <para>
+        Controls the number of second of client's waiting time for individual
+        socket read/write operations. If the specified time passed, the connectoin
+        would be terminated. This can be used both as a force
+        global query timeout and network problems detector.
+        A value of zero (the default) turns this off.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="libpq-connect-tty" xreflabel="tty">
       <term><literal>tty</literal></term>
       <listitem>
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index c96a52bb1b..9045da5e4e 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -208,6 +208,10 @@ static const internalPQconninfoOption PQconninfoOptions[] = {
 		"Connect-timeout", "", 10,	/* strlen(INT32_MAX) == 10 */
 	offsetof(struct pg_conn, connect_timeout)},
 
+	{"socket_timeout", NULL, NULL, NULL,
+		"Socket-timeout", "", 10,   /* strlen(INT32_MAX) == 10 */
+	offsetof(struct pg_conn, pgsocket_timeout)},
+
 	{"dbname", "PGDATABASE", NULL, NULL,
 		"Database-Name", "", 20,
 	offsetof(struct pg_conn, dbName)},
@@ -405,6 +409,8 @@ static char *passwordFromFile(const char *hostname, const char *port, const char
 				 const char *username, const char *pgpassfile);
 static void pgpassfileWarning(PGconn *conn);
 static void default_threadlock(int acquire);
+static bool parse_int_param(const char *value, int *result, PGconn *conn,
+				 const char *context);
 
 
 /* global variable because fe-auth.c needs to access it */
@@ -1234,6 +1240,19 @@ connectOptions2(PGconn *conn)
 			goto oom_error;
 	}
 
+	if (conn->pgsocket_timeout)
+	{
+		if (parse_int_param(conn->pgsocket_timeout,
+			&conn->socket_timeout, conn, "socket_timeout"))
+		{
+			/*
+			 * Rounding could cause communication to fail; need at least 2 secs
+			 */
+			if(conn->socket_timeout > 0 && conn->socket_timeout < 2)
+				conn->socket_timeout = 2;
+		}
+	}
+
 	/*
 	 * Validate target_session_attrs option.
 	 */
@@ -3651,6 +3670,8 @@ freePGconn(PGconn *conn)
 		free(conn->pgtty);
 	if (conn->connect_timeout)
 		free(conn->connect_timeout);
+	if (conn->pgsocket_timeout)
+		free(conn->pgsocket_timeout);
 	if (conn->pgoptions)
 		free(conn->pgoptions);
 	if (conn->appname)
diff --git a/src/interfaces/libpq/fe-misc.c b/src/interfaces/libpq/fe-misc.c
index e5ef8d44bd..59f047e732 100644
--- a/src/interfaces/libpq/fe-misc.c
+++ b/src/interfaces/libpq/fe-misc.c
@@ -983,6 +983,33 @@ pqFlush(PGconn *conn)
 int
 pqWait(int forRead, int forWrite, PGconn *conn)
 {
+	int result;
+
+	if (conn->socket_timeout > 0)
+	{
+		time_t		finish_time;
+
+		/* calculate the finish time based on start + timeout */
+		finish_time = time(NULL) + conn->socket_timeout;
+		result = pqSocketCheck(conn, forRead, forWrite, finish_time);
+
+		if (result < 0)
+			return EOF;
+
+		if (result == 0)
+		{
+			printfPQExpBuffer(&conn->errorMessage,
+					libpq_gettext("timeout expired\n"));
+			conn->status = CONNECTION_BAD;
+			pqsecure_close(conn);
+			closesocket(conn->sock);
+			conn->sock = -1;
+			return EOF;
+		}
+
+		return 0;
+	}
+
 	return pqWaitTimed(forRead, forWrite, conn, (time_t) -1);
 }
 
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 4a93d8edbc..816ebda4dc 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -336,6 +336,7 @@ struct pg_conn
 	char	   *pgtty;			/* tty on which the backend messages is
 								 * displayed (OBSOLETE, NOT USED) */
 	char	   *connect_timeout;	/* connection timeout (numeric string) */
+	char	   *pgsocket_timeout;	/* socket timeout (numeric string) */
 	char	   *client_encoding_initial;	/* encoding to use */
 	char	   *pgoptions;		/* options to start the backend with */
 	char	   *appname;		/* application name */
@@ -500,6 +501,7 @@ struct pg_conn
 
 	/* Buffer for receiving various parts of messages */
 	PQExpBufferData workBuffer; /* expansible string */
+	int			socket_timeout;		/* socket timeout (numeric)*/
 };
 
 /* PGcancel stores all data necessary to cancel a connection. A copy of this

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 8bd57f376b..cb509a710a 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -923,6 +923,49 @@ include_dir 'conf.d'
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-tcp-user-timeout" xreflabel="tcp_user_timeout">
+      <term><varname>tcp_user_timeout</varname> (<type>integer</type>)
+      <indexterm>
+       <primary><varname>tcp_user_timeout</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+       <listitem>
+       <para>
+       Define a wrapper for TCP_USER_TIMEOUT socket option of libpq connection.
+       </para>
+       <para>
+       Specifies the number of milliseconds after which a TCP connection can be
+       aborted by the operation system due to network problems when the data is
+       transmitting through this connection (sending/receiving). A value of 0 uses
+       the system default. This parameter is supported only on systems that support
+       TCP_USER_TIMEOUT or an equivalent socket option, and on Windows; on other
+       systems, it must be zero. In sessions connected via a Unix-domain socket,
+       this parameter is ignored and always reads as zero.
+       </para>
+       <note>
+       <para>
+       This parameter is not supported on Windows, and must be zero.
+       </para>
+       <para>
+       To enable full control under TCP connection use this option together with
+       keepalive.
+       </para>
+       </note>
+      </listitem>
+      <listitem>
+       <para>
+        Specify in milliseconds the time to disconnect to the client
+        when there is no ack packet from the client to the server's data transmission.
+        This parameter is supported on linux version 2.6.37 or later.
+       </para>
+       <note>
+        <para>
+         This parameter is not supported on Windows.
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      </variablelist>
      </sect2>
 
diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
index c39617a430..b649237051 100644
--- a/src/backend/libpq/pqcomm.c
+++ b/src/backend/libpq/pqcomm.c
@@ -825,6 +825,7 @@ StreamConnection(pgsocket server_fd, Port *port)
 		(void) pq_setkeepalivesidle(tcp_keepalives_idle, port);
 		(void) pq_setkeepalivesinterval(tcp_keepalives_interval, port);
 		(void) pq_setkeepalivescount(tcp_keepalives_count, port);
+		(void) pq_settcpusertimeout(tcp_user_timeout, port);
 	}
 
 	return STATUS_OK;
@@ -1926,3 +1927,20 @@ pq_setkeepalivescount(int count, Port *port)
 
 	return STATUS_OK;
 }
+
+int
+pq_settcpusertimeout(int timeout, Port *port)
+{
+#ifdef TCP_USER_TIMEOUT
+	if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
+		return STATUS_OK;
+
+	if (setsockopt(port->sock, IPPROTO_TCP, 18,
+					(char *) &timeout, sizeof(timeout)) << 0 && errno != ENOPROTOOPT)
+	{
+		elog(LOG, "setsockopt(TCP_USER_TIMEOUT) failed: %m");
+		return STATUS_ERROR;
+	}
+#endif
+	return STATUS_OK;
+}
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 156d147c85..a3a96a3b16 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -181,9 +181,11 @@ static const char *show_archive_command(void);
 static void assign_tcp_keepalives_idle(int newval, void *extra);
 static void assign_tcp_keepalives_interval(int newval, void *extra);
 static void assign_tcp_keepalives_count(int newval, void *extra);
+static void assign_tcp_user_timeout(int newval, void *extra);
 static const char *show_tcp_keepalives_idle(void);
 static const char *show_tcp_keepalives_interval(void);
 static const char *show_tcp_keepalives_count(void);
+static const char *show_tcp_user_timeout(void);
 static bool check_maxconnections(int *newval, void **extra, GucSource source);
 static bool check_max_worker_processes(int *newval, void **extra, GucSource source);
 static bool check_autovacuum_max_workers(int *newval, void **extra, GucSource source);
@@ -528,6 +530,7 @@ char	   *application_name;
 int			tcp_keepalives_idle;
 int			tcp_keepalives_interval;
 int			tcp_keepalives_count;
+int			tcp_user_timeout;
 
 /*
  * SSL renegotiation was been removed in PostgreSQL 9.5, but we tolerate it
@@ -3157,6 +3160,17 @@ static struct config_int ConfigureNamesInt[] =
 		NULL, NULL, NULL
 	},
 
+	{
+		{"tcp_user_timeout", PGC_USERSET, CLIENT_CONN_OTHER,
+			gettext_noop("TCP user timeout."),
+			gettext_noop("A value of 0 uses the system default."),
+			GUC_UNIT_MS | GUC_NOT_IN_SAMPLE
+		},
+		&tcp_user_timeout,
+		12000, 0, INT_MAX,
+		NULL, assign_tcp_user_timeout, show_tcp_user_timeout
+	},
+
 	/* End-of-list marker */
 	{
 		{NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL
@@ -10908,6 +10922,23 @@ show_tcp_keepalives_count(void)
 	return nbuf;
 }
 
+static void
+assign_tcp_user_timeout(int newval, void *extra)
+{
+	/* See comments in assign_tcp_keepalives_idle */
+	(void) pq_settcpusertimeout(newval, MyProcPort);
+}
+
+static const char*
+show_tcp_user_timeout(void)
+{
+	/* See comments in assign_tcp_keepalives_idle */
+	static char nbuf[16];
+
+	snprintf(nbuf, sizeof(nbuf), "%d", tcp_user_timeout);
+	return nbuf;
+}
+
 static bool
 check_maxconnections(int *newval, void **extra, GucSource source)
 {
diff --git a/src/include/libpq/libpq-be.h b/src/include/libpq/libpq-be.h
index 248055f10b..2e8b2c34a9 100644
--- a/src/include/libpq/libpq-be.h
+++ b/src/include/libpq/libpq-be.h
@@ -290,5 +290,6 @@ extern int	pq_getkeepalivescount(Port *port);
 extern int	pq_setkeepalivesidle(int idle, Port *port);
 extern int	pq_setkeepalivesinterval(int interval, Port *port);
 extern int	pq_setkeepalivescount(int count, Port *port);
+extern int	pq_settcpusertimeout(int timeout, Port *port);
 
 #endif							/* LIBPQ_BE_H */
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index c07e7b945e..0d023965b2 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -268,6 +268,7 @@ extern PGDLLIMPORT char *application_name;
 extern int	tcp_keepalives_idle;
 extern int	tcp_keepalives_interval;
 extern int	tcp_keepalives_count;
+extern int	tcp_user_timeout;
 
 #ifdef TRACE_SORT
 extern bool trace_sort;

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index c1d1b6b2db..ac4ac5e978 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1249,6 +1249,33 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
       </listitem>
      </varlistentry>
 
+     <varlistentry id="libpq-tcp-user-timeout" xreflabel="libpq_tcp_user_timeout">
+      <term><literal>tcp_user_timeout</literal></term>
+      <listitem>
+       <para>
+        Define a wrapper for TCP_USER_TIMEOUT socket option of libpq connection.
+       </para>
+       <para>
+        Specifies the number of milliseconds after which a TCP connection can be
+        aborted by the operation system due to network problems when the data is
+        transmitting through this connection (sending/receiving). A value of 0 uses
+        the system default. This parameter is supported only on systems that support
+        TCP_USER_TIMEOUT or an equivalent socket option, and on Windows; on other
+        systems, it must be zero. In sessions connected via a Unix-domain socket,
+        this parameter is ignored and always reads as zero.
+       </para>
+       <note>
+        <para>
+         This parameter is not supported on Windows, and must be zero.
+        </para>
+        <para>
+         To enable full control under TCP connection use this option together with
+         keepalive.
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="libpq-connect-tty" xreflabel="tty">
       <term><literal>tty</literal></term>
       <listitem>
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index c96a52bb1b..bc0baf820c 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -325,6 +325,11 @@ static const internalPQconninfoOption PQconninfoOptions[] = {
 		"Target-Session-Attrs", "", 11, /* sizeof("read-write") = 11 */
 	offsetof(struct pg_conn, target_session_attrs)},
 
+	/* TCP USER TIMEOUT */
+	{"tcp_user_timeout", NULL, NULL, NULL,
+		"TCP_user_timeout", "", 10,	/* strlen(INT32_MAX) == 10 */
+		offsetof(struct pg_conn, pgtcp_user_timeout)},
+
 	/* Terminating entry --- MUST BE LAST */
 	{NULL, NULL, NULL, NULL,
 	NULL, NULL, 0}
@@ -1782,6 +1787,40 @@ setKeepalivesWin32(PGconn *conn)
 #endif							/* SIO_KEEPALIVE_VALS */
 #endif							/* WIN32 */
 
+/*
+ * Set the TCP user timeout.
+ */
+static int
+setTCPUserTimeout(PGconn *conn)
+{
+	int			timeout;
+
+	if (conn->pgtcp_user_timeout == NULL)
+		return 1;
+
+	if (!parse_int_param(conn->pgtcp_user_timeout,
+					&timeout, conn,	"tcp_user_timeout"))
+		return 0;
+
+	if (timeout < 0)
+		timeout = 0;
+
+#ifdef TCP_USER_TIMEOUT
+	if (setsockopt(conn->sock, IPPROTO_TCP, 18,
+					(char *) &timeout, sizeof(timeout)) < 0 && errno != ENOPROTOOPT)
+	{
+		char		sebuf[256];
+
+		appendPQExpBuffer(&conn->errorMessage,
+					libpq_gettext("setsockopt(TCP_USER_TIMEOUT) failed: %s\n"),
+						SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+		return 0;
+	}
+#endif
+
+	return 1;
+}
+
 /* ----------
  * connectDBStart -
  *		Begin the process of making a connection to the backend.
@@ -2373,6 +2412,17 @@ keep_going:						/* We will come back to here until there is
 						goto keep_going;
 					}
 
+					if (!IS_AF_UNIX(addr_cur->ai_family))
+					{
+						if (!setTCPUserTimeout(conn))
+						{
+							closesocket(conn->sock);
+							conn->sock = -1;
+							conn->addr_cur = addr_cur->ai_next;
+							goto keep_going;
+						}
+					}
+
 #ifdef F_SETFD
 					if (fcntl(conn->sock, F_SETFD, FD_CLOEXEC) == -1)
 					{
@@ -3651,6 +3701,8 @@ freePGconn(PGconn *conn)
 		free(conn->pgtty);
 	if (conn->connect_timeout)
 		free(conn->connect_timeout);
+	if (conn->pgtcp_user_timeout)
+		free(conn->pgtcp_user_timeout);
 	if (conn->pgoptions)
 		free(conn->pgoptions);
 	if (conn->appname)
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 4a93d8edbc..729342c4cc 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -336,6 +336,7 @@ struct pg_conn
 	char	   *pgtty;			/* tty on which the backend messages is
 								 * displayed (OBSOLETE, NOT USED) */
 	char	   *connect_timeout;	/* connection timeout (numeric string) */
+	char	   *pgtcp_user_timeout;	/* tcp user timeout (numeric string) */
 	char	   *client_encoding_initial;	/* encoding to use */
 	char	   *pgoptions;		/* options to start the backend with */
 	char	   *appname;		/* application name */
@@ -351,6 +352,7 @@ struct pg_conn
 										 * retransmits */
 	char	   *keepalives_count;	/* maximum number of TCP keepalive
 									 * retransmits */
+	char	   *tcp_user_timeout;	/* tcp user timeout */
 	char	   *sslmode;		/* SSL mode (require,prefer,allow,disable) */
 	char	   *sslcompression; /* SSL compression (0 or 1) */
 	char	   *sslkey;			/* client key filename */