David K. Bainbridge | 215e024 | 2017-09-05 23:18:24 -0700 | [diff] [blame] | 1 | // Copyright 2014 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 darwin freebsd linux |
| 6 | |
| 7 | package ipv4 |
| 8 | |
| 9 | import ( |
| 10 | "net" |
| 11 | "unsafe" |
| 12 | |
| 13 | "golang.org/x/net/internal/socket" |
| 14 | ) |
| 15 | |
| 16 | func (so *sockOpt) getIPMreqn(c *socket.Conn) (*net.Interface, error) { |
| 17 | b := make([]byte, so.Len) |
| 18 | if _, err := so.Get(c, b); err != nil { |
| 19 | return nil, err |
| 20 | } |
| 21 | mreqn := (*ipMreqn)(unsafe.Pointer(&b[0])) |
| 22 | if mreqn.Ifindex == 0 { |
| 23 | return nil, nil |
| 24 | } |
| 25 | ifi, err := net.InterfaceByIndex(int(mreqn.Ifindex)) |
| 26 | if err != nil { |
| 27 | return nil, err |
| 28 | } |
| 29 | return ifi, nil |
| 30 | } |
| 31 | |
| 32 | func (so *sockOpt) setIPMreqn(c *socket.Conn, ifi *net.Interface, grp net.IP) error { |
| 33 | var mreqn ipMreqn |
| 34 | if ifi != nil { |
| 35 | mreqn.Ifindex = int32(ifi.Index) |
| 36 | } |
| 37 | if grp != nil { |
| 38 | mreqn.Multiaddr = [4]byte{grp[0], grp[1], grp[2], grp[3]} |
| 39 | } |
| 40 | b := (*[sizeofIPMreqn]byte)(unsafe.Pointer(&mreqn))[:sizeofIPMreqn] |
| 41 | return so.Set(c, b) |
| 42 | } |