go.net/ipv4: make use of net.PacketConn embedding

R=dave
CC=golang-dev
https://golang.org/cl/10319043

ipv4/endpoint.go

@@ -18,15 +18,15 @@ type Conn struct {
 }
 
 type genericOpt struct {
-	c net.Conn
+	net.Conn
 }
 
-func (c *genericOpt) ok() bool { return c != nil && c.c != nil }
+func (c *genericOpt) ok() bool { return c != nil && c.Conn != nil }
 
 // NewConn returns a new Conn.
 func NewConn(c net.Conn) *Conn {
 	return &Conn{
-		genericOpt: genericOpt{c},
+		genericOpt: genericOpt{Conn: c},
 	}
 }
 
@@ -42,10 +42,10 @@ type PacketConn struct {
 }
 
 type dgramOpt struct {
-	c net.PacketConn
+	net.PacketConn
 }
 
-func (c *dgramOpt) ok() bool { return c != nil && c.c != nil }
+func (c *dgramOpt) ok() bool { return c != nil && c.PacketConn != nil }
 
 // SetControlMessage sets the per packet IP-level socket options.
 func (c *PacketConn) SetControlMessage(cf ControlFlags, on bool) error {
@@ -65,7 +65,7 @@ func (c *PacketConn) SetDeadline(t time.Time) error {
 	if !c.payloadHandler.ok() {
 		return syscall.EINVAL
 	}
-	return c.payloadHandler.c.SetDeadline(t)
+	return c.payloadHandler.PacketConn.SetDeadline(t)
 }
 
 // SetReadDeadline sets the read deadline associated with the
@@ -74,7 +74,7 @@ func (c *PacketConn) SetReadDeadline(t time.Time) error {
 	if !c.payloadHandler.ok() {
 		return syscall.EINVAL
 	}
-	return c.payloadHandler.c.SetReadDeadline(t)
+	return c.payloadHandler.PacketConn.SetReadDeadline(t)
 }
 
 // SetWriteDeadline sets the write deadline associated with the
@@ -83,7 +83,7 @@ func (c *PacketConn) SetWriteDeadline(t time.Time) error {
 	if !c.payloadHandler.ok() {
 		return syscall.EINVAL
 	}
-	return c.payloadHandler.c.SetWriteDeadline(t)
+	return c.payloadHandler.PacketConn.SetWriteDeadline(t)
 }
 
 // Close closes the endpoint.
@@ -91,16 +91,16 @@ func (c *PacketConn) Close() error {
 	if !c.payloadHandler.ok() {
 		return syscall.EINVAL
 	}
-	return c.payloadHandler.c.Close()
+	return c.payloadHandler.PacketConn.Close()
 }
 
 // NewPacketConn returns a new PacketConn using c as its underlying
 // transport.
 func NewPacketConn(c net.PacketConn) *PacketConn {
 	return &PacketConn{
-		genericOpt:     genericOpt{c.(net.Conn)},
-		dgramOpt:       dgramOpt{c},
-		payloadHandler: payloadHandler{c: c},
+		genericOpt:     genericOpt{Conn: c.(net.Conn)},
+		dgramOpt:       dgramOpt{PacketConn: c},
+		payloadHandler: payloadHandler{PacketConn: c},
 	}
 }
 
@@ -166,8 +166,8 @@ func (c *RawConn) Close() error {
 // transport.
 func NewRawConn(c net.PacketConn) (*RawConn, error) {
 	r := &RawConn{
-		genericOpt:    genericOpt{c.(net.Conn)},
-		dgramOpt:      dgramOpt{c},
+		genericOpt:    genericOpt{Conn: c.(net.Conn)},
+		dgramOpt:      dgramOpt{PacketConn: c},
 		packetHandler: packetHandler{c: c.(*net.IPConn)},
 	}
 	fd, err := r.packetHandler.sysfd()

ipv4/helper_plan9.go

@@ -4,9 +4,7 @@
 
 package ipv4
 
-import (
-	"syscall"
-)
+import "syscall"
 
 func (c *genericOpt) sysfd() (int, error) {
 	// TODO(mikio): Implement this

ipv4/helper_unix.go

@@ -12,7 +12,7 @@ import (
 )
 
 func (c *genericOpt) sysfd() (int, error) {
-	switch p := c.c.(type) {
+	switch p := c.Conn.(type) {
 	case *net.TCPConn, *net.UDPConn, *net.IPConn:
 		return sysfd(p)
 	}
@@ -20,7 +20,7 @@ func (c *genericOpt) sysfd() (int, error) {
 }
 
 func (c *dgramOpt) sysfd() (int, error) {
-	switch p := c.c.(type) {
+	switch p := c.PacketConn.(type) {
 	case *net.UDPConn, *net.IPConn:
 		return sysfd(p.(net.Conn))
 	}
@@ -28,7 +28,7 @@ func (c *dgramOpt) sysfd() (int, error) {
 }
 
 func (c *payloadHandler) sysfd() (int, error) {
-	return sysfd(c.c.(net.Conn))
+	return sysfd(c.PacketConn.(net.Conn))
 }
 
 func (c *packetHandler) sysfd() (int, error) {

ipv4/helper_windows.go

@@ -11,7 +11,7 @@ import (
 )
 
 func (c *genericOpt) sysfd() (syscall.Handle, error) {
-	switch p := c.c.(type) {
+	switch p := c.Conn.(type) {
 	case *net.TCPConn, *net.UDPConn, *net.IPConn:
 		return sysfd(p)
 	}
@@ -19,7 +19,7 @@ func (c *genericOpt) sysfd() (syscall.Handle, error) {
 }
 
 func (c *dgramOpt) sysfd() (syscall.Handle, error) {
-	switch p := c.c.(type) {
+	switch p := c.PacketConn.(type) {
 	case *net.UDPConn, *net.IPConn:
 		return sysfd(p.(net.Conn))
 	}
@@ -27,7 +27,7 @@ func (c *dgramOpt) sysfd() (syscall.Handle, error) {
 }
 
 func (c *payloadHandler) sysfd() (syscall.Handle, error) {
-	return sysfd(c.c.(net.Conn))
+	return sysfd(c.PacketConn.(net.Conn))
 }
 
 func (c *packetHandler) sysfd() (syscall.Handle, error) {

ipv4/payload.go

@@ -11,11 +11,11 @@ import (
 
 // A payloadHandler represents the IPv4 datagram payload handler.
 type payloadHandler struct {
-	c net.PacketConn
+	net.PacketConn
 	rawOpt
 }
 
-func (c *payloadHandler) ok() bool { return c != nil && c.c != nil }
+func (c *payloadHandler) ok() bool { return c != nil && c.PacketConn != nil }
 
 // ReadFrom reads a payload of the received IPv4 datagram, from the
 // endpoint c, copying the payload into b.  It returns the number of
@@ -27,14 +27,14 @@ func (c *payloadHandler) ReadFrom(b []byte) (n int, cm *ControlMessage, src net.
 	}
 	oob := newControlMessage(&c.rawOpt)
 	var oobn int
-	switch rd := c.c.(type) {
+	switch c := c.PacketConn.(type) {
 	case *net.UDPConn:
-		if n, oobn, _, src, err = rd.ReadMsgUDP(b, oob); err != nil {
+		if n, oobn, _, src, err = c.ReadMsgUDP(b, oob); err != nil {
 			return 0, nil, nil, err
 		}
 	case *net.IPConn:
 		nb := make([]byte, maxHeaderLen+len(b))
-		if n, oobn, _, src, err = rd.ReadMsgIP(nb, oob); err != nil {
+		if n, oobn, _, src, err = c.ReadMsgIP(nb, oob); err != nil {
 			return 0, nil, nil, err
 		}
 		hdrlen := int(nb[0]&0x0f) << 2
@@ -66,11 +66,11 @@ func (c *payloadHandler) WriteTo(b []byte, cm *ControlMessage, dst net.Addr) (n
 	if dst == nil {
 		return 0, errMissingAddress
 	}
-	switch wr := c.c.(type) {
+	switch c := c.PacketConn.(type) {
 	case *net.UDPConn:
-		n, _, err = wr.WriteMsgUDP(b, oob, dst.(*net.UDPAddr))
+		n, _, err = c.WriteMsgUDP(b, oob, dst.(*net.UDPAddr))
 	case *net.IPConn:
-		n, _, err = wr.WriteMsgIP(b, oob, dst.(*net.IPAddr))
+		n, _, err = c.WriteMsgIP(b, oob, dst.(*net.IPAddr))
 	default:
 		return 0, errInvalidConnType
 	}