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 nacl plan9 windows |
| 6 | |
| 7 | package ipv4 |
| 8 | |
| 9 | import ( |
| 10 | "net" |
| 11 | "syscall" |
| 12 | ) |
| 13 | |
| 14 | // ReadFrom reads a payload of the received IPv4 datagram, from the |
| 15 | // endpoint c, copying the payload into b. It returns the number of |
| 16 | // bytes copied into b, the control message cm and the source address |
| 17 | // src of the received datagram. |
| 18 | func (c *payloadHandler) ReadFrom(b []byte) (n int, cm *ControlMessage, src net.Addr, err error) { |
| 19 | if !c.ok() { |
| 20 | return 0, nil, nil, syscall.EINVAL |
| 21 | } |
| 22 | if n, src, err = c.PacketConn.ReadFrom(b); err != nil { |
| 23 | return 0, nil, nil, err |
| 24 | } |
| 25 | return |
| 26 | } |
| 27 | |
| 28 | // WriteTo writes a payload of the IPv4 datagram, to the destination |
| 29 | // address dst through the endpoint c, copying the payload from b. It |
| 30 | // returns the number of bytes written. The control message cm allows |
| 31 | // the datagram path and the outgoing interface to be specified. |
| 32 | // Currently only Darwin and Linux support this. The cm may be nil if |
| 33 | // control of the outgoing datagram is not required. |
| 34 | func (c *payloadHandler) WriteTo(b []byte, cm *ControlMessage, dst net.Addr) (n int, err error) { |
| 35 | if !c.ok() { |
| 36 | return 0, syscall.EINVAL |
| 37 | } |
| 38 | if dst == nil { |
| 39 | return 0, errMissingAddress |
| 40 | } |
| 41 | return c.PacketConn.WriteTo(b, dst) |
| 42 | } |