cleanup

transport/internet/udp/source_forging_linux.go

@@ -0,0 +1,55 @@
+// +build linux
+
+package udp
+
+import (
+	"net"
+	"os"
+	"syscall"
+)
+
+//Currently, Only IPv4 Forge is supported
+func TransmitSocket(src net.Addr, dst net.Addr) (net.Conn, error) {
+	var fd int
+	var err error
+	fd, err = syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, 0)
+	if err != nil {
+		return nil, newError("failed to create fd").Base(err).AtWarning()
+	}
+	err = syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
+	if err != nil {
+		return nil, newError("failed to set resuse_addr").Base(err).AtWarning()
+	}
+
+	err = syscall.SetsockoptInt(fd, syscall.SOL_IP, syscall.IP_TRANSPARENT, 1)
+	if err != nil {
+		return nil, newError("failed to set transparent").Base(err).AtWarning()
+	}
+
+	ip := src.(*net.UDPAddr).IP.To4()
+	var ip2 [4]byte
+	copy(ip2[:], ip)
+	srcaddr := syscall.SockaddrInet4{}
+	srcaddr.Addr = ip2
+	srcaddr.Port = src.(*net.UDPAddr).Port
+	err = syscall.Bind(fd, &srcaddr)
+	if err != nil {
+		return nil, newError("failed to bind source address").Base(err).AtWarning()
+	}
+	ipd := dst.(*net.UDPAddr).IP.To4()
+	var ip2d [4]byte
+	copy(ip2d[:], ipd)
+	dstaddr := syscall.SockaddrInet4{}
+	dstaddr.Addr = ip2d
+	dstaddr.Port = dst.(*net.UDPAddr).Port
+	err = syscall.Connect(fd, &dstaddr)
+	if err != nil {
+		return nil, newError("failed to connect to source address").Base(err).AtWarning()
+	}
+	fdf := os.NewFile(uintptr(fd), "/dev/udp/")
+	c, err := net.FileConn(fdf)
+	if err != nil {
+		return nil, newError("failed to create file conn").Base(err).AtWarning()
+	}
+	return c, nil
+}