blob: 082c36d73e19b725fef5237ad1a34914c71de1fb [file] [log] [blame]
// Copyright 2017 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 go1.9
package ipv4
import (
"net"
"golang.org/x/net/internal/socket"
)
func (c *packetHandler) readFrom(b []byte) (h *Header, p []byte, cm *ControlMessage, err error) {
c.rawOpt.RLock()
m := socket.Message{
Buffers: [][]byte{b},
OOB: NewControlMessage(c.rawOpt.cflags),
}
c.rawOpt.RUnlock()
if err := c.RecvMsg(&m, 0); err != nil {
return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err}
}
var hs []byte
if hs, p, err = slicePacket(b[:m.N]); err != nil {
return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err}
}
if h, err = ParseHeader(hs); err != nil {
return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err}
}
if m.NN > 0 {
cm = new(ControlMessage)
if err := cm.Parse(m.OOB[:m.NN]); err != nil {
return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err}
}
}
if src, ok := m.Addr.(*net.IPAddr); ok && cm != nil {
cm.Src = src.IP
}
return
}
func (c *packetHandler) writeTo(h *Header, p []byte, cm *ControlMessage) error {
m := socket.Message{
OOB: cm.Marshal(),
}
wh, err := h.Marshal()
if err != nil {
return err
}
m.Buffers = [][]byte{wh, p}
dst := new(net.IPAddr)
if cm != nil {
if ip := cm.Dst.To4(); ip != nil {
dst.IP = ip
}
}
if dst.IP == nil {
dst.IP = h.Dst
}
m.Addr = dst
if err := c.SendMsg(&m, 0); err != nil {
return &net.OpError{Op: "write", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Addr: opAddr(dst), Err: err}
}
return nil
}