Support KCP as a network typekcp

Signed-off-by: Sam Whited <sam@samwhited.com>

1 files changed, 14 insertions, 2 deletions

diff --git a/listener.go b/listener.go
index 4163cb9..86f1470 100644
--- a/listener.go
+++ b/listener.go
@@ -7,7 +7,8 @@ import (
 	"encoding/hex"
 	"net"
 
-	pt "git.torproject.org/pluggable-transports/goptlib.git"
+	"git.torproject.org/pluggable-transports/goptlib.git"
+	"github.com/xtaci/kcp-go/v5"
 	"gitlab.com/yawning/obfs4.git/common/ntor"
 	"gitlab.com/yawning/obfs4.git/transports/base"
 	"gitlab.com/yawning/obfs4.git/transports/obfs4"
@@ -41,8 +42,19 @@ func NewListenConfigCert(cert string) (*ListenConfig, error) {
 // Listen announces on the local network address.
 //
 // See func net.Dial for a description of the network and address parameters.
+// In addition to the networks supported by net.Dial, Listen supports the
+// network string "kcp" which creates a reliable UDP connection.
+// If the kcp network is used, the underlying ListenConfig is ignored and
+// options set on it do not apply.
 func (lc *ListenConfig) Listen(ctx context.Context, network, address string) (*Listener, error) {
-	ln, err := lc.ListenConfig.Listen(ctx, network, address)
+	var ln net.Listener
+	var err error
+	switch network {
+	case netKCP:
+		ln, err = kcp.Listen(address)
+	default:
+		ln, err = lc.ListenConfig.Listen(ctx, network, address)
+	}
 	if err != nil {
 		return nil, err
 	}