1 files changed, 81 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/ipv4/payload_cmsg.go b/vendor/golang.org/x/net/ipv4/payload_cmsg.go
new file mode 100644
index 000000000..d358fc3ac
--- /dev/null
+++ b/vendor/golang.org/x/net/ipv4/payload_cmsg.go
@@ -0,0 +1,81 @@
+// Copyright 2012 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !plan9,!solaris,!windows
+
+package ipv4
+
+import (
+	"net"
+	"syscall"
+)
+
+// ReadFrom reads a payload of the received IPv4 datagram, from the
+// endpoint c, copying the payload into b.  It returns the number of
+// bytes copied into b, the control message cm and the source address
+// src of the received datagram.
+func (c *payloadHandler) ReadFrom(b []byte) (n int, cm *ControlMessage, src net.Addr, err error) {
+	if !c.ok() {
+		return 0, nil, nil, syscall.EINVAL
+	}
+	oob := newControlMessage(&c.rawOpt)
+	var oobn int
+	switch c := c.PacketConn.(type) {
+	case *net.UDPConn:
+		if n, oobn, _, src, err = c.ReadMsgUDP(b, oob); err != nil {
+			return 0, nil, nil, err
+		}
+	case *net.IPConn:
+		if sockOpts[ssoStripHeader].name > 0 {
+			if n, oobn, _, src, err = c.ReadMsgIP(b, oob); err != nil {
+				return 0, nil, nil, err
+			}
+		} else {
+			nb := make([]byte, maxHeaderLen+len(b))
+			if n, oobn, _, src, err = c.ReadMsgIP(nb, oob); err != nil {
+				return 0, nil, nil, err
+			}
+			hdrlen := int(nb[0]&0x0f) << 2
+			copy(b, nb[hdrlen:])
+			n -= hdrlen
+		}
+	default:
+		return 0, nil, nil, errInvalidConnType
+	}
+	if cm, err = parseControlMessage(oob[:oobn]); err != nil {
+		return 0, nil, nil, err
+	}
+	if cm != nil {
+		cm.Src = netAddrToIP4(src)
+	}
+	return
+}
+
+// WriteTo writes a payload of the IPv4 datagram, to the destination
+// address dst through the endpoint c, copying the payload from b.  It
+// returns the number of bytes written.  The control message cm allows
+// the datagram path and the outgoing interface to be specified.
+// Currently only Darwin and Linux support this.  The cm may be nil if
+// control of the outgoing datagram is not required.
+func (c *payloadHandler) WriteTo(b []byte, cm *ControlMessage, dst net.Addr) (n int, err error) {
+	if !c.ok() {
+		return 0, syscall.EINVAL
+	}
+	oob := marshalControlMessage(cm)
+	if dst == nil {
+		return 0, errMissingAddress
+	}
+	switch c := c.PacketConn.(type) {
+	case *net.UDPConn:
+		n, _, err = c.WriteMsgUDP(b, oob, dst.(*net.UDPAddr))
+	case *net.IPConn:
+		n, _, err = c.WriteMsgIP(b, oob, dst.(*net.IPAddr))
+	default:
+		return 0, errInvalidConnType
+	}
+	if err != nil {
+		return 0, err
+	}
+	return
+}