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 | package icmp |
| 6 | |
| 7 | import ( |
| 8 | "net" |
| 9 | "runtime" |
| 10 | "syscall" |
| 11 | "time" |
| 12 | |
| 13 | "golang.org/x/net/ipv4" |
| 14 | "golang.org/x/net/ipv6" |
| 15 | ) |
| 16 | |
| 17 | var _ net.PacketConn = &PacketConn{} |
| 18 | |
| 19 | // A PacketConn represents a packet network endpoint that uses either |
| 20 | // ICMPv4 or ICMPv6. |
| 21 | type PacketConn struct { |
| 22 | c net.PacketConn |
| 23 | p4 *ipv4.PacketConn |
| 24 | p6 *ipv6.PacketConn |
| 25 | } |
| 26 | |
| 27 | func (c *PacketConn) ok() bool { return c != nil && c.c != nil } |
| 28 | |
| 29 | // IPv4PacketConn returns the ipv4.PacketConn of c. |
| 30 | // It returns nil when c is not created as the endpoint for ICMPv4. |
| 31 | func (c *PacketConn) IPv4PacketConn() *ipv4.PacketConn { |
| 32 | if !c.ok() { |
| 33 | return nil |
| 34 | } |
| 35 | return c.p4 |
| 36 | } |
| 37 | |
| 38 | // IPv6PacketConn returns the ipv6.PacketConn of c. |
| 39 | // It returns nil when c is not created as the endpoint for ICMPv6. |
| 40 | func (c *PacketConn) IPv6PacketConn() *ipv6.PacketConn { |
| 41 | if !c.ok() { |
| 42 | return nil |
| 43 | } |
| 44 | return c.p6 |
| 45 | } |
| 46 | |
| 47 | // ReadFrom reads an ICMP message from the connection. |
| 48 | func (c *PacketConn) ReadFrom(b []byte) (int, net.Addr, error) { |
| 49 | if !c.ok() { |
| 50 | return 0, nil, syscall.EINVAL |
| 51 | } |
| 52 | // Please be informed that ipv4.NewPacketConn enables |
| 53 | // IP_STRIPHDR option by default on Darwin. |
| 54 | // See golang.org/issue/9395 for further information. |
| 55 | if runtime.GOOS == "darwin" && c.p4 != nil { |
| 56 | n, _, peer, err := c.p4.ReadFrom(b) |
| 57 | return n, peer, err |
| 58 | } |
| 59 | return c.c.ReadFrom(b) |
| 60 | } |
| 61 | |
| 62 | // WriteTo writes the ICMP message b to dst. |
| 63 | // Dst must be net.UDPAddr when c is a non-privileged |
| 64 | // datagram-oriented ICMP endpoint. Otherwise it must be net.IPAddr. |
| 65 | func (c *PacketConn) WriteTo(b []byte, dst net.Addr) (int, error) { |
| 66 | if !c.ok() { |
| 67 | return 0, syscall.EINVAL |
| 68 | } |
| 69 | return c.c.WriteTo(b, dst) |
| 70 | } |
| 71 | |
| 72 | // Close closes the endpoint. |
| 73 | func (c *PacketConn) Close() error { |
| 74 | if !c.ok() { |
| 75 | return syscall.EINVAL |
| 76 | } |
| 77 | return c.c.Close() |
| 78 | } |
| 79 | |
| 80 | // LocalAddr returns the local network address. |
| 81 | func (c *PacketConn) LocalAddr() net.Addr { |
| 82 | if !c.ok() { |
| 83 | return nil |
| 84 | } |
| 85 | return c.c.LocalAddr() |
| 86 | } |
| 87 | |
| 88 | // SetDeadline sets the read and write deadlines associated with the |
| 89 | // endpoint. |
| 90 | func (c *PacketConn) SetDeadline(t time.Time) error { |
| 91 | if !c.ok() { |
| 92 | return syscall.EINVAL |
| 93 | } |
| 94 | return c.c.SetDeadline(t) |
| 95 | } |
| 96 | |
| 97 | // SetReadDeadline sets the read deadline associated with the |
| 98 | // endpoint. |
| 99 | func (c *PacketConn) SetReadDeadline(t time.Time) error { |
| 100 | if !c.ok() { |
| 101 | return syscall.EINVAL |
| 102 | } |
| 103 | return c.c.SetReadDeadline(t) |
| 104 | } |
| 105 | |
| 106 | // SetWriteDeadline sets the write deadline associated with the |
| 107 | // endpoint. |
| 108 | func (c *PacketConn) SetWriteDeadline(t time.Time) error { |
| 109 | if !c.ok() { |
| 110 | return syscall.EINVAL |
| 111 | } |
| 112 | return c.c.SetWriteDeadline(t) |
| 113 | } |