1 // Copyright 2011 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.
5 // +build darwin freebsd linux
10 #include <sys/types.h>
11 #include <sys/socket.h>
12 #include <netinet/in.h>
25 func libc_getaddrinfo(node *byte, service *byte, hints *syscall.Addrinfo, res **syscall.Addrinfo) int
28 func libc_freeaddrinfo(res *syscall.Addrinfo)
31 func libc_gai_strerror(errcode int) *byte
33 // bytePtrToString takes a NUL-terminated array of bytes and convert
35 func bytePtrToString(p *byte) string {
36 a := (*[10000]byte)(unsafe.Pointer(p))
44 func cgoLookupHost(name string) (addrs []string, err error, completed bool) {
45 ip, err, completed := cgoLookupIP(name)
46 for _, p := range ip {
47 addrs = append(addrs, p.String())
52 func cgoLookupPort(net, service string) (port int, err error, completed bool) {
53 var res *syscall.Addrinfo
54 var hints syscall.Addrinfo
59 case "tcp", "tcp4", "tcp6":
60 hints.Ai_socktype = syscall.SOCK_STREAM
61 hints.Ai_protocol = syscall.IPPROTO_TCP
62 case "udp", "udp4", "udp6":
63 hints.Ai_socktype = syscall.SOCK_DGRAM
64 hints.Ai_protocol = syscall.IPPROTO_UDP
66 return 0, UnknownNetworkError(net), true
71 hints.Ai_family = syscall.AF_INET
73 hints.Ai_family = syscall.AF_INET6
77 s := syscall.StringBytePtr(service)
78 syscall.Entersyscall()
79 gerrno := libc_getaddrinfo(nil, s, &hints, &res)
82 defer libc_freeaddrinfo(res)
83 for r := res; r != nil; r = r.Ai_next {
88 sa := (*syscall.RawSockaddrInet4)(unsafe.Pointer(r.Ai_addr))
89 p := (*[2]byte)(unsafe.Pointer(&sa.Port))
90 return int(p[0])<<8 | int(p[1]), nil, true
91 case syscall.AF_INET6:
92 sa := (*syscall.RawSockaddrInet6)(unsafe.Pointer(r.Ai_addr))
93 p := (*[2]byte)(unsafe.Pointer(&sa.Port))
94 return int(p[0])<<8 | int(p[1]), nil, true
98 return 0, &AddrError{"unknown port", net + "/" + service}, true
101 func cgoLookupIPCNAME(name string) (addrs []IP, cname string, err error, completed bool) {
102 var res *syscall.Addrinfo
103 var hints syscall.Addrinfo
105 // NOTE(rsc): In theory there are approximately balanced
106 // arguments for and against including AI_ADDRCONFIG
107 // in the flags (it includes IPv4 results only on IPv4 systems,
108 // and similarly for IPv6), but in practice setting it causes
109 // getaddrinfo to return the wrong canonical name on Linux.
110 // So definitely leave it out.
111 hints.Ai_flags = int32((syscall.AI_ALL | syscall.AI_V4MAPPED | syscall.AI_CANONNAME) & cgoAddrInfoMask())
113 h := syscall.StringBytePtr(name)
114 syscall.Entersyscall()
115 gerrno := libc_getaddrinfo(h, nil, &hints, &res)
116 syscall.Exitsyscall()
119 if gerrno == syscall.EAI_NONAME {
121 } else if gerrno == syscall.EAI_SYSTEM {
122 str = syscall.GetErrno().Error()
124 str = bytePtrToString(libc_gai_strerror(gerrno))
126 return nil, "", &DNSError{Err: str, Name: name}, true
128 defer libc_freeaddrinfo(res)
130 cname = bytePtrToString((*byte)(unsafe.Pointer(res.Ai_canonname)))
134 if len(cname) > 0 && cname[len(cname)-1] != '.' {
138 for r := res; r != nil; r = r.Ai_next {
139 // Everything comes back twice, once for UDP and once for TCP.
140 if r.Ai_socktype != syscall.SOCK_STREAM {
146 case syscall.AF_INET:
147 sa := (*syscall.RawSockaddrInet4)(unsafe.Pointer(r.Ai_addr))
148 addrs = append(addrs, copyIP(sa.Addr[:]))
149 case syscall.AF_INET6:
150 sa := (*syscall.RawSockaddrInet6)(unsafe.Pointer(r.Ai_addr))
151 addrs = append(addrs, copyIP(sa.Addr[:]))
154 return addrs, cname, nil, true
157 func cgoLookupIP(name string) (addrs []IP, err error, completed bool) {
158 addrs, _, err, completed = cgoLookupIPCNAME(name)
162 func cgoLookupCNAME(name string) (cname string, err error, completed bool) {
163 _, cname, err, completed = cgoLookupIPCNAME(name)
167 func copyIP(x IP) IP {
168 y := make(IP, len(x))