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 darwin dragonfly freebsd netbsd openbsd solaris windows |
| 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) setIPMreq(c *socket.Conn, ifi *net.Interface, grp net.IP) error { |
| 17 | mreq := ipMreq{Multiaddr: [4]byte{grp[0], grp[1], grp[2], grp[3]}} |
| 18 | if err := setIPMreqInterface(&mreq, ifi); err != nil { |
| 19 | return err |
| 20 | } |
| 21 | b := (*[sizeofIPMreq]byte)(unsafe.Pointer(&mreq))[:sizeofIPMreq] |
| 22 | return so.Set(c, b) |
| 23 | } |
| 24 | |
| 25 | func (so *sockOpt) getMulticastIf(c *socket.Conn) (*net.Interface, error) { |
| 26 | var b [4]byte |
| 27 | if _, err := so.Get(c, b[:]); err != nil { |
| 28 | return nil, err |
| 29 | } |
| 30 | ifi, err := netIP4ToInterface(net.IPv4(b[0], b[1], b[2], b[3])) |
| 31 | if err != nil { |
| 32 | return nil, err |
| 33 | } |
| 34 | return ifi, nil |
| 35 | } |
| 36 | |
| 37 | func (so *sockOpt) setMulticastIf(c *socket.Conn, ifi *net.Interface) error { |
| 38 | ip, err := netInterfaceToIP4(ifi) |
| 39 | if err != nil { |
| 40 | return err |
| 41 | } |
| 42 | var b [4]byte |
| 43 | copy(b[:], ip) |
| 44 | return so.Set(c, b[:]) |
| 45 | } |
| 46 | |
| 47 | func setIPMreqInterface(mreq *ipMreq, ifi *net.Interface) error { |
| 48 | if ifi == nil { |
| 49 | return nil |
| 50 | } |
| 51 | ifat, err := ifi.Addrs() |
| 52 | if err != nil { |
| 53 | return err |
| 54 | } |
| 55 | for _, ifa := range ifat { |
| 56 | switch ifa := ifa.(type) { |
| 57 | case *net.IPAddr: |
| 58 | if ip := ifa.IP.To4(); ip != nil { |
| 59 | copy(mreq.Interface[:], ip) |
| 60 | return nil |
| 61 | } |
| 62 | case *net.IPNet: |
| 63 | if ip := ifa.IP.To4(); ip != nil { |
| 64 | copy(mreq.Interface[:], ip) |
| 65 | return nil |
| 66 | } |
| 67 | } |
| 68 | } |
| 69 | return errNoSuchInterface |
| 70 | } |
| 71 | |
| 72 | func netIP4ToInterface(ip net.IP) (*net.Interface, error) { |
| 73 | ift, err := net.Interfaces() |
| 74 | if err != nil { |
| 75 | return nil, err |
| 76 | } |
| 77 | for _, ifi := range ift { |
| 78 | ifat, err := ifi.Addrs() |
| 79 | if err != nil { |
| 80 | return nil, err |
| 81 | } |
| 82 | for _, ifa := range ifat { |
| 83 | switch ifa := ifa.(type) { |
| 84 | case *net.IPAddr: |
| 85 | if ip.Equal(ifa.IP) { |
| 86 | return &ifi, nil |
| 87 | } |
| 88 | case *net.IPNet: |
| 89 | if ip.Equal(ifa.IP) { |
| 90 | return &ifi, nil |
| 91 | } |
| 92 | } |
| 93 | } |
| 94 | } |
| 95 | return nil, errNoSuchInterface |
| 96 | } |
| 97 | |
| 98 | func netInterfaceToIP4(ifi *net.Interface) (net.IP, error) { |
| 99 | if ifi == nil { |
| 100 | return net.IPv4zero.To4(), nil |
| 101 | } |
| 102 | ifat, err := ifi.Addrs() |
| 103 | if err != nil { |
| 104 | return nil, err |
| 105 | } |
| 106 | for _, ifa := range ifat { |
| 107 | switch ifa := ifa.(type) { |
| 108 | case *net.IPAddr: |
| 109 | if ip := ifa.IP.To4(); ip != nil { |
| 110 | return ip, nil |
| 111 | } |
| 112 | case *net.IPNet: |
| 113 | if ip := ifa.IP.To4(); ip != nil { |
| 114 | return ip, nil |
| 115 | } |
| 116 | } |
| 117 | } |
| 118 | return nil, errNoSuchInterface |
| 119 | } |