David K. Bainbridge | 215e024 | 2017-09-05 23:18:24 -0700 | [diff] [blame] | 1 | // Copyright 2012 The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | // +build !go1.9 |
| 6 | // +build !nacl,!plan9,!windows |
| 7 | |
| 8 | package ipv4 |
| 9 | |
| 10 | import "net" |
| 11 | |
| 12 | func (c *payloadHandler) readFrom(b []byte) (n int, cm *ControlMessage, src net.Addr, err error) { |
| 13 | c.rawOpt.RLock() |
| 14 | oob := NewControlMessage(c.rawOpt.cflags) |
| 15 | c.rawOpt.RUnlock() |
| 16 | var nn int |
| 17 | switch c := c.PacketConn.(type) { |
| 18 | case *net.UDPConn: |
| 19 | if n, nn, _, src, err = c.ReadMsgUDP(b, oob); err != nil { |
| 20 | return 0, nil, nil, err |
| 21 | } |
| 22 | case *net.IPConn: |
| 23 | nb := make([]byte, maxHeaderLen+len(b)) |
| 24 | if n, nn, _, src, err = c.ReadMsgIP(nb, oob); err != nil { |
| 25 | return 0, nil, nil, err |
| 26 | } |
| 27 | hdrlen := int(nb[0]&0x0f) << 2 |
| 28 | copy(b, nb[hdrlen:]) |
| 29 | n -= hdrlen |
| 30 | default: |
| 31 | return 0, nil, nil, &net.OpError{Op: "read", Net: c.LocalAddr().Network(), Source: c.LocalAddr(), Err: errInvalidConnType} |
| 32 | } |
| 33 | if nn > 0 { |
| 34 | cm = new(ControlMessage) |
| 35 | if err = cm.Parse(oob[:nn]); err != nil { |
| 36 | return 0, nil, nil, &net.OpError{Op: "read", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: err} |
| 37 | } |
| 38 | } |
| 39 | if cm != nil { |
| 40 | cm.Src = netAddrToIP4(src) |
| 41 | } |
| 42 | return |
| 43 | } |
| 44 | |
| 45 | func (c *payloadHandler) writeTo(b []byte, cm *ControlMessage, dst net.Addr) (n int, err error) { |
| 46 | oob := cm.Marshal() |
| 47 | if dst == nil { |
| 48 | return 0, &net.OpError{Op: "write", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: errMissingAddress} |
| 49 | } |
| 50 | switch c := c.PacketConn.(type) { |
| 51 | case *net.UDPConn: |
| 52 | n, _, err = c.WriteMsgUDP(b, oob, dst.(*net.UDPAddr)) |
| 53 | case *net.IPConn: |
| 54 | n, _, err = c.WriteMsgIP(b, oob, dst.(*net.IPAddr)) |
| 55 | default: |
| 56 | return 0, &net.OpError{Op: "write", Net: c.LocalAddr().Network(), Source: c.LocalAddr(), Addr: opAddr(dst), Err: errInvalidConnType} |
| 57 | } |
| 58 | return |
| 59 | } |