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
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
// Copyright 2009 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.
package net
import (
"syscall"
"unsafe"
"os"
"sync"
)
var hostentLock sync.Mutex
var serventLock sync.Mutex
func LookupHost(name string) (addrs []string, err os.Error) {
ips, err := LookupIP(name)
if err != nil {
return
}
addrs = make([]string, 0, len(ips))
for _, ip := range ips {
addrs = append(addrs, ip.String())
}
return
}
func LookupIP(name string) (addrs []IP, err os.Error) {
hostentLock.Lock()
defer hostentLock.Unlock()
h, e := syscall.GetHostByName(name)
if e != 0 {
return nil, os.NewSyscallError("GetHostByName", e)
}
switch h.AddrType {
case syscall.AF_INET:
i := 0
addrs = make([]IP, 100) // plenty of room to grow
for p := (*[100](*[4]byte))(unsafe.Pointer(h.AddrList)); i < cap(addrs) && p[i] != nil; i++ {
addrs[i] = IPv4(p[i][0], p[i][1], p[i][2], p[i][3])
}
addrs = addrs[0:i]
default: // TODO(vcc): Implement non IPv4 address lookups.
return nil, os.NewSyscallError("LookupHost", syscall.EWINDOWS)
}
return addrs, nil
}
func LookupPort(network, service string) (port int, err os.Error) {
switch network {
case "tcp4", "tcp6":
network = "tcp"
case "udp4", "udp6":
network = "udp"
}
serventLock.Lock()
defer serventLock.Unlock()
s, e := syscall.GetServByName(service, network)
if e != 0 {
return 0, os.NewSyscallError("GetServByName", e)
}
return int(syscall.Ntohs(s.Port)), nil
}
func LookupCNAME(name string) (cname string, err os.Error) {
var r *syscall.DNSRecord
e := syscall.DnsQuery(name, syscall.DNS_TYPE_CNAME, 0, nil, &r, nil)
if int(e) != 0 {
return "", os.NewSyscallError("LookupCNAME", int(e))
}
defer syscall.DnsRecordListFree(r, 1)
if r != nil && r.Type == syscall.DNS_TYPE_CNAME {
v := (*syscall.DNSPTRData)(unsafe.Pointer(&r.Data[0]))
cname = syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:]) + "."
}
return
}
func LookupSRV(service, proto, name string) (cname string, addrs []*SRV, err os.Error) {
var r *syscall.DNSRecord
target := "_" + service + "._" + proto + "." + name
e := syscall.DnsQuery(target, syscall.DNS_TYPE_SRV, 0, nil, &r, nil)
if int(e) != 0 {
return "", nil, os.NewSyscallError("LookupSRV", int(e))
}
defer syscall.DnsRecordListFree(r, 1)
addrs = make([]*SRV, 0, 10)
for p := r; p != nil && p.Type == syscall.DNS_TYPE_SRV; p = p.Next {
v := (*syscall.DNSSRVData)(unsafe.Pointer(&p.Data[0]))
addrs = append(addrs, &SRV{syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Target))[:]), v.Port, v.Priority, v.Weight})
}
byPriorityWeight(addrs).sort()
return name, addrs, nil
}
func LookupMX(name string) (mx []*MX, err os.Error) {
var r *syscall.DNSRecord
e := syscall.DnsQuery(name, syscall.DNS_TYPE_MX, 0, nil, &r, nil)
if int(e) != 0 {
return nil, os.NewSyscallError("LookupMX", int(e))
}
defer syscall.DnsRecordListFree(r, 1)
mx = make([]*MX, 0, 10)
for p := r; p != nil && p.Type == syscall.DNS_TYPE_MX; p = p.Next {
v := (*syscall.DNSMXData)(unsafe.Pointer(&p.Data[0]))
mx = append(mx, &MX{syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.NameExchange))[:]) + ".", v.Preference})
}
byPref(mx).sort()
return mx, nil
}
func LookupAddr(addr string) (name []string, err os.Error) {
arpa, err := reverseaddr(addr)
if err != nil {
return nil, err
}
var r *syscall.DNSRecord
e := syscall.DnsQuery(arpa, syscall.DNS_TYPE_PTR, 0, nil, &r, nil)
if int(e) != 0 {
return nil, os.NewSyscallError("LookupAddr", int(e))
}
defer syscall.DnsRecordListFree(r, 1)
name = make([]string, 0, 10)
for p := r; p != nil && p.Type == syscall.DNS_TYPE_PTR; p = p.Next {
v := (*syscall.DNSPTRData)(unsafe.Pointer(&p.Data[0]))
name = append(name, syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:]))
}
return name, nil
}
|
