initial commit

vendor/golang.org/x/net/ipv4/control_pktinfo.go

@@ -0,0 +1,37 @@
+// Copyright 2014 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 darwin linux
+
+package ipv4
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/net/internal/iana"
+)
+
+func marshalPacketInfo(b []byte, cm *ControlMessage) []byte {
+	m := (*syscall.Cmsghdr)(unsafe.Pointer(&b[0]))
+	m.Level = iana.ProtocolIP
+	m.Type = sysIP_PKTINFO
+	m.SetLen(syscall.CmsgLen(sysSizeofInetPktinfo))
+	if cm != nil {
+		pi := (*sysInetPktinfo)(unsafe.Pointer(&b[syscall.CmsgLen(0)]))
+		if ip := cm.Src.To4(); ip != nil {
+			copy(pi.Spec_dst[:], ip)
+		}
+		if cm.IfIndex > 0 {
+			pi.setIfindex(cm.IfIndex)
+		}
+	}
+	return b[syscall.CmsgSpace(sysSizeofInetPktinfo):]
+}
+
+func parsePacketInfo(cm *ControlMessage, b []byte) {
+	pi := (*sysInetPktinfo)(unsafe.Pointer(&b[0]))
+	cm.IfIndex = int(pi.Ifindex)
+	cm.Dst = pi.Addr[:]
+}