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. 4 5// +build darwin freebsd linux netbsd openbsd 6 7package net 8 9/* 10#include <sys/types.h> 11#include <sys/socket.h> 12#include <netinet/in.h> 13#include <netdb.h> 14#include <stdlib.h> 15#include <unistd.h> 16#include <string.h> 17*/ 18 19import ( 20 "syscall" 21 "unsafe" 22) 23 24//extern getaddrinfo 25func libc_getaddrinfo(node *byte, service *byte, hints *syscall.Addrinfo, res **syscall.Addrinfo) int 26 27//extern freeaddrinfo 28func libc_freeaddrinfo(res *syscall.Addrinfo) 29 30//extern gai_strerror 31func libc_gai_strerror(errcode int) *byte 32 33// bytePtrToString takes a NUL-terminated array of bytes and convert 34// it to a Go string. 35func bytePtrToString(p *byte) string { 36 a := (*[10000]byte)(unsafe.Pointer(p)) 37 i := 0 38 for a[i] != 0 { 39 i++ 40 } 41 return string(a[:i]) 42} 43 44func 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()) 48 } 49 return 50} 51 52func cgoLookupPort(net, service string) (port int, err error, completed bool) { 53 var res *syscall.Addrinfo 54 var hints syscall.Addrinfo 55 56 switch net { 57 case "": 58 // no hints 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 65 default: 66 return 0, UnknownNetworkError(net), true 67 } 68 if len(net) >= 4 { 69 switch net[3] { 70 case '4': 71 hints.Ai_family = syscall.AF_INET 72 case '6': 73 hints.Ai_family = syscall.AF_INET6 74 } 75 } 76 77 s := syscall.StringBytePtr(service) 78 syscall.Entersyscall() 79 gerrno := libc_getaddrinfo(nil, s, &hints, &res) 80 syscall.Exitsyscall() 81 if gerrno == 0 { 82 defer libc_freeaddrinfo(res) 83 for r := res; r != nil; r = r.Ai_next { 84 switch r.Ai_family { 85 default: 86 continue 87 case syscall.AF_INET: 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 95 } 96 } 97 } 98 return 0, &AddrError{"unknown port", net + "/" + service}, true 99} 100 101func cgoLookupIPCNAME(name string) (addrs []IP, cname string, err error, completed bool) { 102 var res *syscall.Addrinfo 103 var hints syscall.Addrinfo 104 105 hints.Ai_flags = int32(cgoAddrInfoFlags()) 106 hints.Ai_socktype = syscall.SOCK_STREAM 107 108 h := syscall.StringBytePtr(name) 109 syscall.Entersyscall() 110 gerrno := libc_getaddrinfo(h, nil, &hints, &res) 111 syscall.Exitsyscall() 112 if gerrno != 0 { 113 var str string 114 if gerrno == syscall.EAI_NONAME { 115 str = noSuchHost 116 } else if gerrno == syscall.EAI_SYSTEM { 117 str = syscall.GetErrno().Error() 118 } else { 119 str = bytePtrToString(libc_gai_strerror(gerrno)) 120 } 121 return nil, "", &DNSError{Err: str, Name: name}, true 122 } 123 defer libc_freeaddrinfo(res) 124 if res != nil { 125 cname = bytePtrToString((*byte)(unsafe.Pointer(res.Ai_canonname))) 126 if cname == "" { 127 cname = name 128 } 129 if len(cname) > 0 && cname[len(cname)-1] != '.' { 130 cname += "." 131 } 132 } 133 for r := res; r != nil; r = r.Ai_next { 134 // We only asked for SOCK_STREAM, but check anyhow. 135 if r.Ai_socktype != syscall.SOCK_STREAM { 136 continue 137 } 138 switch r.Ai_family { 139 default: 140 continue 141 case syscall.AF_INET: 142 sa := (*syscall.RawSockaddrInet4)(unsafe.Pointer(r.Ai_addr)) 143 addrs = append(addrs, copyIP(sa.Addr[:])) 144 case syscall.AF_INET6: 145 sa := (*syscall.RawSockaddrInet6)(unsafe.Pointer(r.Ai_addr)) 146 addrs = append(addrs, copyIP(sa.Addr[:])) 147 } 148 } 149 return addrs, cname, nil, true 150} 151 152func cgoLookupIP(name string) (addrs []IP, err error, completed bool) { 153 addrs, _, err, completed = cgoLookupIPCNAME(name) 154 return 155} 156 157func cgoLookupCNAME(name string) (cname string, err error, completed bool) { 158 _, cname, err, completed = cgoLookupIPCNAME(name) 159 return 160} 161 162func copyIP(x IP) IP { 163 y := make(IP, len(x)) 164 copy(y, x) 165 return y 166} 167