From cc567c9beace114554f7e7f50c3a5181cc44a07d Mon Sep 17 00:00:00 2001 From: Susant Sahani Date: Thu, 14 Aug 2014 23:06:12 +0530 Subject: socket: Add support for TCP defer accept TCP_DEFER_ACCEPT Allow a listener to be awakened only when data arrives on the socket. If TCP_DEFER_ACCEPT set on a server-side listening socket, the TCP/IP stack will not to wait for the final ACK packet and not to initiate the process until the first packet of real data has arrived. After sending the SYN/ACK, the server will then wait for a data packet from a client. Now, only three packets will be sent over the network, and the connection establishment delay will be significantly reduced. --- src/core/dbus-socket.c | 1 + src/core/load-fragment-gperf.gperf.m4 | 1 + src/core/socket.c | 12 ++++++++++++ src/core/socket.h | 1 + 4 files changed, 15 insertions(+) (limited to 'src/core') diff --git a/src/core/dbus-socket.c b/src/core/dbus-socket.c index bdf111c9e3..cc55b8d71b 100644 --- a/src/core/dbus-socket.c +++ b/src/core/dbus-socket.c @@ -100,6 +100,7 @@ const sd_bus_vtable bus_socket_vtable[] = { SD_BUS_PROPERTY("KeepAliveTime", "t", bus_property_get_usec, offsetof(Socket, keep_alive_time), SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("KeepAliveInterval", "t", bus_property_get_usec, offsetof(Socket, keep_alive_interval), SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("KeepAliveProbes", "u", bus_property_get_unsigned, offsetof(Socket, keep_alive_cnt), SD_BUS_VTABLE_PROPERTY_CONST), + SD_BUS_PROPERTY("DeferAccept" , "t", bus_property_get_usec, offsetof(Socket, defer_accept), SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("Priority", "i", bus_property_get_int, offsetof(Socket, priority), SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("ReceiveBuffer", "t", bus_property_get_size, offsetof(Socket, receive_buffer), SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("SendBuffer", "t", bus_property_get_size, offsetof(Socket, send_buffer), SD_BUS_VTABLE_PROPERTY_CONST), diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4 index 67bd0e5209..b4e2b25743 100644 --- a/src/core/load-fragment-gperf.gperf.m4 +++ b/src/core/load-fragment-gperf.gperf.m4 @@ -234,6 +234,7 @@ Socket.KeepAlive, config_parse_bool, 0, Socket.KeepAliveTime, config_parse_sec, 0, offsetof(Socket, keep_alive_time) Socket.KeepAliveInterval, config_parse_sec, 0, offsetof(Socket, keep_alive_interval) Socket.KeepAliveProbes, config_parse_unsigned, 0, offsetof(Socket, keep_alive_cnt) +Socket.DeferAccept, config_parse_sec, 0, offsetof(Socket, defer_accept) Socket.NoDelay, config_parse_bool, 0, offsetof(Socket, no_delay) Socket.Priority, config_parse_int, 0, offsetof(Socket, priority) Socket.ReceiveBuffer, config_parse_iec_size, 0, offsetof(Socket, receive_buffer) diff --git a/src/core/socket.c b/src/core/socket.c index d6d9821f57..a16b20d739 100644 --- a/src/core/socket.c +++ b/src/core/socket.c @@ -613,6 +613,12 @@ static void socket_dump(Unit *u, FILE *f, const char *prefix) { "%sKeepAliveProbes: %u\n", prefix, s->keep_alive_cnt); + if(s->defer_accept) + fprintf(f, + "%sDeferAccept: %s\n", + prefix, format_timespan(time_string, FORMAT_TIMESPAN_MAX, + s->defer_accept, USEC_PER_SEC)); + LIST_FOREACH(port, p, s->ports) { if (p->type == SOCKET_SOCKET) { @@ -828,6 +834,12 @@ static void socket_apply_socket_options(Socket *s, int fd) { log_warning_unit(UNIT(s)->id, "TCP_KEEPCNT failed: %m"); } + if (s->defer_accept) { + int value = s->defer_accept / USEC_PER_SEC; + if (setsockopt(fd, SOL_TCP, TCP_DEFER_ACCEPT, &value, sizeof(value)) < 0) + log_warning_unit(UNIT(s)->id, "TCP_DEFER_ACCEPT failed: %m"); + } + if (s->no_delay) { int b = s->no_delay; if (setsockopt(fd, SOL_TCP, TCP_NODELAY, &b, sizeof(b)) < 0) diff --git a/src/core/socket.h b/src/core/socket.h index 8871eb1ca3..eede70564a 100644 --- a/src/core/socket.h +++ b/src/core/socket.h @@ -105,6 +105,7 @@ struct Socket { usec_t timeout_usec; usec_t keep_alive_time; usec_t keep_alive_interval; + usec_t defer_accept; ExecCommand* exec_command[_SOCKET_EXEC_COMMAND_MAX]; ExecContext exec_context; -- cgit v1.2.3-54-g00ecf