Add tcpMaxSeg to sockopt (XTLS#2002)

ohbaby30 · Apr 30, 2023 · dd81ad5 · dd81ad5
1 parent 18e5b09
commit dd81ad5
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Showing 4 changed files with 29 additions and 2 deletions.
diff --git a/infra/conf/transport_internet.go b/infra/conf/transport_internet.go
@@ -617,6 +617,7 @@ type SocketConfig struct {
 	TCPKeepAliveIdle     int32       `json:"tcpKeepAliveIdle"`
 	TCPCongestion        string      `json:"tcpCongestion"`
 	TCPWindowClamp       int32       `json:"tcpWindowClamp"`
+	TCPMaxSeg	     int32	 `json:"tcpMaxSeg"`
 	TCPUserTimeout       int32       `json:"tcpUserTimeout"`
 	V6only               bool        `json:"v6only"`
 	Interface            string      `json:"interface"`
@@ -670,6 +671,7 @@ func (c *SocketConfig) Build() (*internet.SocketConfig, error) {
 		TcpKeepAliveIdle:     c.TCPKeepAliveIdle,
 		TcpCongestion:        c.TCPCongestion,
 		TcpWindowClamp:       c.TCPWindowClamp,
+		TcpMaxSeg:	      c.TCPMaxSeg,
 		TcpUserTimeout:       c.TCPUserTimeout,
 		V6Only:               c.V6only,
 		Interface:            c.Interface,

diff --git a/transport/internet/config.pb.go b/transport/internet/config.pb.go
diff --git a/transport/internet/config.proto b/transport/internet/config.proto
@@ -106,4 +106,6 @@ message SocketConfig {
   int32 tcp_window_clamp = 15;
 
   int32 tcp_user_timeout = 16;
+
+  int32 tcp_max_seg = 17;
 }
diff --git a/transport/internet/sockopt_linux.go b/transport/internet/sockopt_linux.go
@@ -94,6 +94,13 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 				return newError("failed to set TCP_USER_TIMEOUT", err)
 			}
 		}
+
+		if config.TcpMaxSeg > 0 {
+			if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, unix.TCP_MAXSEG, int(config.TcpMaxSeg)); err != nil {
+				return newError("failed to set TCP_MAXSEG", err)
+			}
+		}
+
 	}
 
 	if config.Tproxy.IsEnabled() {
@@ -156,6 +163,12 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 				return newError("failed to set TCP_USER_TIMEOUT", err)
 			}
 		}
+
+		if config.TcpMaxSeg > 0 {
+			if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, unix.TCP_MAXSEG, int(config.TcpMaxSeg)); err != nil {
+				return newError("failed to set TCP_MAXSEG", err)
+			}
+		}
 	}
 
 	if config.Tproxy.IsEnabled() {