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// 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) (cname string, addrs []string, err os.Error) {
hostentLock.Lock()
defer hostentLock.Unlock()
h, e := syscall.GetHostByName(name)
if e != 0 {
return "", nil, os.NewSyscallError("GetHostByName", e)
}
cname = name
switch h.AddrType {
case syscall.AF_INET:
i := 0
addrs = make([]string, 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]).String()
}
addrs = addrs[0:i]
default: // TODO(vcc): Implement non IPv4 address lookups.
return "", nil, os.NewSyscallError("LookupHost", syscall.EWINDOWS)
}
return cname, addrs, nil
}
type SRV struct {
Target string
Port uint16
Priority uint16
Weight uint16
}
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, 100)
i := 0
for p := r; p != nil && p.Type == syscall.DNS_TYPE_SRV; p = p.Next {
v := (*syscall.DNSSRVData)(unsafe.Pointer(&p.Data[0]))
addrs[i] = &SRV{syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Target))[:]), v.Port, v.Priority, v.Weight}
i++
}
addrs = addrs[0:i]
return name, 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
}
// TODO(brainman): Following code is only to get tests running.
func isDomainName(s string) bool {
panic("unimplemented")
}
func reverseaddr(addr string) (arpa string, err os.Error) {
panic("unimplemented")
}
// DNSError represents a DNS lookup error.
type DNSError struct {
Error string // description of the error
Name string // name looked for
Server string // server used
IsTimeout bool
}
func (e *DNSError) String() string {
if e == nil {
return "<nil>"
}
s := "lookup " + e.Name
if e.Server != "" {
s += " on " + e.Server
}
s += ": " + e.Error
return s
}
func (e *DNSError) Timeout() bool { return e.IsTimeout }
func (e *DNSError) Temporary() bool { return e.IsTimeout }
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