zabov/vendor/golang.org/x/net/ipv6/payload_cmsg.go

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2020-10-08 16:14:07 -04:00
// Copyright 2013 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 aix darwin dragonfly freebsd linux netbsd openbsd solaris
package ipv6
import (
"net"
"golang.org/x/net/internal/socket"
)
// ReadFrom reads a payload of the received IPv6 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, errInvalidConn
}
c.rawOpt.RLock()
m := socket.Message{
Buffers: [][]byte{b},
OOB: NewControlMessage(c.rawOpt.cflags),
}
c.rawOpt.RUnlock()
switch c.PacketConn.(type) {
case *net.UDPConn:
if err := c.RecvMsg(&m, 0); err != nil {
return 0, nil, nil, &net.OpError{Op: "read", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: err}
}
case *net.IPConn:
if err := c.RecvMsg(&m, 0); err != nil {
return 0, nil, nil, &net.OpError{Op: "read", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: err}
}
default:
return 0, nil, nil, &net.OpError{Op: "read", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: errInvalidConnType}
}
if m.NN > 0 {
cm = new(ControlMessage)
if err := cm.Parse(m.OOB[:m.NN]); err != nil {
return 0, nil, nil, &net.OpError{Op: "read", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: err}
}
cm.Src = netAddrToIP16(m.Addr)
}
return m.N, cm, m.Addr, nil
}
// WriteTo writes a payload of the IPv6 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 IPv6 header fields and the datagram path to be specified. 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, errInvalidConn
}
m := socket.Message{
Buffers: [][]byte{b},
OOB: cm.Marshal(),
Addr: dst,
}
err = c.SendMsg(&m, 0)
if err != nil {
err = &net.OpError{Op: "write", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Addr: opAddr(dst), Err: err}
}
return m.N, err
}