1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
|
// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris
// +build aix darwin dragonfly freebsd hurd linux netbsd openbsd solaris
package net
import (
"errors"
"syscall"
)
func readRawConn(c syscall.RawConn, b []byte) (int, error) {
var operr error
var n int
err := c.Read(func(s uintptr) bool {
n, operr = syscall.Read(int(s), b)
if operr == syscall.EAGAIN {
return false
}
return true
})
if err != nil {
return n, err
}
return n, operr
}
func writeRawConn(c syscall.RawConn, b []byte) error {
var operr error
err := c.Write(func(s uintptr) bool {
_, operr = syscall.Write(int(s), b)
if operr == syscall.EAGAIN {
return false
}
return true
})
if err != nil {
return err
}
return operr
}
func controlRawConn(c syscall.RawConn, addr Addr) error {
var operr error
fn := func(s uintptr) {
_, operr = syscall.GetsockoptInt(int(s), syscall.SOL_SOCKET, syscall.SO_REUSEADDR)
if operr != nil {
return
}
switch addr := addr.(type) {
case *TCPAddr:
// There's no guarantee that IP-level socket
// options work well with dual stack sockets.
// A simple solution would be to take a look
// at the bound address to the raw connection
// and to classify the address family of the
// underlying socket by the bound address:
//
// - When IP.To16() != nil and IP.To4() == nil,
// we can assume that the raw connection
// consists of an IPv6 socket using only
// IPv6 addresses.
//
// - When IP.To16() == nil and IP.To4() != nil,
// the raw connection consists of an IPv4
// socket using only IPv4 addresses.
//
// - Otherwise, the raw connection is a dual
// stack socket, an IPv6 socket using IPv6
// addresses including IPv4-mapped or
// IPv4-embedded IPv6 addresses.
if addr.IP.To16() != nil && addr.IP.To4() == nil {
operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IPV6, syscall.IPV6_UNICAST_HOPS, 1)
} else if addr.IP.To16() == nil && addr.IP.To4() != nil {
operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IP, syscall.IP_TTL, 1)
}
}
}
if err := c.Control(fn); err != nil {
return err
}
return operr
}
func controlOnConnSetup(network string, address string, c syscall.RawConn) error {
var operr error
var fn func(uintptr)
switch network {
case "tcp", "udp", "ip":
return errors.New("ambiguous network: " + network)
case "unix", "unixpacket", "unixgram":
fn = func(s uintptr) {
_, operr = syscall.GetsockoptInt(int(s), syscall.SOL_SOCKET, syscall.SO_ERROR)
}
default:
switch network[len(network)-1] {
case '4':
fn = func(s uintptr) {
operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IP, syscall.IP_TTL, 1)
}
case '6':
fn = func(s uintptr) {
operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IPV6, syscall.IPV6_UNICAST_HOPS, 1)
}
default:
return errors.New("unknown network: " + network)
}
}
if err := c.Control(fn); err != nil {
return err
}
return operr
}
|