mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-08 20:55:01 +00:00
275 lines
7.3 KiB
Go
275 lines
7.3 KiB
Go
// Copyright 2011 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.
|
|
|
|
// +build cgo,!netgo
|
|
// +build darwin dragonfly freebsd linux netbsd openbsd solaris
|
|
|
|
package net
|
|
|
|
/*
|
|
#include <sys/types.h>
|
|
#include <sys/socket.h>
|
|
#include <netinet/in.h>
|
|
#include <netdb.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <string.h>
|
|
*/
|
|
|
|
import (
|
|
"syscall"
|
|
"unsafe"
|
|
)
|
|
|
|
//extern getaddrinfo
|
|
func libc_getaddrinfo(node *byte, service *byte, hints *syscall.Addrinfo, res **syscall.Addrinfo) int
|
|
|
|
//extern freeaddrinfo
|
|
func libc_freeaddrinfo(res *syscall.Addrinfo)
|
|
|
|
//extern gai_strerror
|
|
func libc_gai_strerror(errcode int) *byte
|
|
|
|
// bytePtrToString takes a NUL-terminated array of bytes and convert
|
|
// it to a Go string.
|
|
func bytePtrToString(p *byte) string {
|
|
a := (*[10000]byte)(unsafe.Pointer(p))
|
|
i := 0
|
|
for a[i] != 0 {
|
|
i++
|
|
}
|
|
return string(a[:i])
|
|
}
|
|
|
|
// An addrinfoErrno represents a getaddrinfo, getnameinfo-specific
|
|
// error number. It's a signed number and a zero value is a non-error
|
|
// by convention.
|
|
type addrinfoErrno int
|
|
|
|
func (eai addrinfoErrno) Error() string { return bytePtrToString(libc_gai_strerror(int(eai))) }
|
|
func (eai addrinfoErrno) Temporary() bool { return eai == syscall.EAI_AGAIN }
|
|
func (eai addrinfoErrno) Timeout() bool { return false }
|
|
|
|
func cgoLookupHost(name string) (hosts []string, err error, completed bool) {
|
|
addrs, err, completed := cgoLookupIP(name)
|
|
for _, addr := range addrs {
|
|
hosts = append(hosts, addr.String())
|
|
}
|
|
return
|
|
}
|
|
|
|
func cgoLookupPort(network, service string) (port int, err error, completed bool) {
|
|
acquireThread()
|
|
defer releaseThread()
|
|
|
|
var hints syscall.Addrinfo
|
|
switch network {
|
|
case "": // no hints
|
|
case "tcp", "tcp4", "tcp6":
|
|
hints.Ai_socktype = syscall.SOCK_STREAM
|
|
hints.Ai_protocol = syscall.IPPROTO_TCP
|
|
case "udp", "udp4", "udp6":
|
|
hints.Ai_socktype = syscall.SOCK_DGRAM
|
|
hints.Ai_protocol = syscall.IPPROTO_UDP
|
|
default:
|
|
return 0, &DNSError{Err: "unknown network", Name: network + "/" + service}, true
|
|
}
|
|
if len(network) >= 4 {
|
|
switch network[3] {
|
|
case '4':
|
|
hints.Ai_family = syscall.AF_INET
|
|
case '6':
|
|
hints.Ai_family = syscall.AF_INET6
|
|
}
|
|
}
|
|
|
|
s := syscall.StringBytePtr(service)
|
|
var res *syscall.Addrinfo
|
|
syscall.Entersyscall()
|
|
gerrno := libc_getaddrinfo(nil, s, &hints, &res)
|
|
syscall.Exitsyscall()
|
|
if gerrno != 0 {
|
|
switch gerrno {
|
|
case syscall.EAI_SYSTEM:
|
|
errno := syscall.GetErrno()
|
|
if errno == 0 { // see golang.org/issue/6232
|
|
errno = syscall.EMFILE
|
|
}
|
|
err = errno
|
|
default:
|
|
err = addrinfoErrno(gerrno)
|
|
}
|
|
return 0, &DNSError{Err: err.Error(), Name: network + "/" + service}, true
|
|
}
|
|
defer libc_freeaddrinfo(res)
|
|
|
|
for r := res; r != nil; r = r.Ai_next {
|
|
switch r.Ai_family {
|
|
case syscall.AF_INET:
|
|
sa := (*syscall.RawSockaddrInet4)(unsafe.Pointer(r.Ai_addr))
|
|
p := (*[2]byte)(unsafe.Pointer(&sa.Port))
|
|
return int(p[0])<<8 | int(p[1]), nil, true
|
|
case syscall.AF_INET6:
|
|
sa := (*syscall.RawSockaddrInet6)(unsafe.Pointer(r.Ai_addr))
|
|
p := (*[2]byte)(unsafe.Pointer(&sa.Port))
|
|
return int(p[0])<<8 | int(p[1]), nil, true
|
|
}
|
|
}
|
|
return 0, &DNSError{Err: "unknown port", Name: network + "/" + service}, true
|
|
}
|
|
|
|
func cgoLookupIPCNAME(name string) (addrs []IPAddr, cname string, err error, completed bool) {
|
|
acquireThread()
|
|
defer releaseThread()
|
|
|
|
var hints syscall.Addrinfo
|
|
hints.Ai_flags = int32(cgoAddrInfoFlags)
|
|
hints.Ai_socktype = syscall.SOCK_STREAM
|
|
|
|
h := syscall.StringBytePtr(name)
|
|
var res *syscall.Addrinfo
|
|
syscall.Entersyscall()
|
|
gerrno := libc_getaddrinfo(h, nil, &hints, &res)
|
|
syscall.Exitsyscall()
|
|
if gerrno != 0 {
|
|
switch gerrno {
|
|
case syscall.EAI_SYSTEM:
|
|
errno := syscall.GetErrno()
|
|
if errno == 0 {
|
|
// err should not be nil, but sometimes getaddrinfo returns
|
|
// gerrno == C.EAI_SYSTEM with err == nil on Linux.
|
|
// The report claims that it happens when we have too many
|
|
// open files, so use syscall.EMFILE (too many open files in system).
|
|
// Most system calls would return ENFILE (too many open files),
|
|
// so at the least EMFILE should be easy to recognize if this
|
|
// comes up again. golang.org/issue/6232.
|
|
errno = syscall.EMFILE
|
|
}
|
|
err = errno
|
|
case syscall.EAI_NONAME:
|
|
err = errNoSuchHost
|
|
default:
|
|
err = addrinfoErrno(gerrno)
|
|
}
|
|
return nil, "", &DNSError{Err: err.Error(), Name: name}, true
|
|
}
|
|
defer libc_freeaddrinfo(res)
|
|
|
|
if res != nil {
|
|
cname = bytePtrToString((*byte)(unsafe.Pointer(res.Ai_canonname)))
|
|
if cname == "" {
|
|
cname = name
|
|
}
|
|
if len(cname) > 0 && cname[len(cname)-1] != '.' {
|
|
cname += "."
|
|
}
|
|
}
|
|
for r := res; r != nil; r = r.Ai_next {
|
|
// We only asked for SOCK_STREAM, but check anyhow.
|
|
if r.Ai_socktype != syscall.SOCK_STREAM {
|
|
continue
|
|
}
|
|
switch r.Ai_family {
|
|
case syscall.AF_INET:
|
|
sa := (*syscall.RawSockaddrInet4)(unsafe.Pointer(r.Ai_addr))
|
|
addr := IPAddr{IP: copyIP(sa.Addr[:])}
|
|
addrs = append(addrs, addr)
|
|
case syscall.AF_INET6:
|
|
sa := (*syscall.RawSockaddrInet6)(unsafe.Pointer(r.Ai_addr))
|
|
addr := IPAddr{IP: copyIP(sa.Addr[:]), Zone: zoneToString(int(sa.Scope_id))}
|
|
addrs = append(addrs, addr)
|
|
}
|
|
}
|
|
return addrs, cname, nil, true
|
|
}
|
|
|
|
func cgoLookupIP(name string) (addrs []IPAddr, err error, completed bool) {
|
|
addrs, _, err, completed = cgoLookupIPCNAME(name)
|
|
return
|
|
}
|
|
|
|
func cgoLookupCNAME(name string) (cname string, err error, completed bool) {
|
|
_, cname, err, completed = cgoLookupIPCNAME(name)
|
|
return
|
|
}
|
|
|
|
// These are roughly enough for the following:
|
|
//
|
|
// Source Encoding Maximum length of single name entry
|
|
// Unicast DNS ASCII or <=253 + a NUL terminator
|
|
// Unicode in RFC 5892 252 * total number of labels + delimiters + a NUL terminator
|
|
// Multicast DNS UTF-8 in RFC 5198 or <=253 + a NUL terminator
|
|
// the same as unicast DNS ASCII <=253 + a NUL terminator
|
|
// Local database various depends on implementation
|
|
const (
|
|
nameinfoLen = 64
|
|
maxNameinfoLen = 4096
|
|
)
|
|
|
|
func cgoLookupPTR(addr string) ([]string, error, bool) {
|
|
acquireThread()
|
|
defer releaseThread()
|
|
|
|
var zone string
|
|
ip := parseIPv4(addr)
|
|
if ip == nil {
|
|
ip, zone = parseIPv6(addr, true)
|
|
}
|
|
if ip == nil {
|
|
return nil, &DNSError{Err: "invalid address", Name: addr}, true
|
|
}
|
|
sa, salen := cgoSockaddr(ip, zone)
|
|
if sa == nil {
|
|
return nil, &DNSError{Err: "invalid address " + ip.String(), Name: addr}, true
|
|
}
|
|
var err error
|
|
var b []byte
|
|
var gerrno int
|
|
for l := nameinfoLen; l <= maxNameinfoLen; l *= 2 {
|
|
b = make([]byte, l)
|
|
gerrno, err = cgoNameinfoPTR(b, sa, salen)
|
|
if gerrno == 0 || gerrno != syscall.EAI_OVERFLOW {
|
|
break
|
|
}
|
|
}
|
|
if gerrno != 0 {
|
|
switch gerrno {
|
|
case syscall.EAI_SYSTEM:
|
|
if err == nil { // see golang.org/issue/6232
|
|
err = syscall.EMFILE
|
|
}
|
|
default:
|
|
err = addrinfoErrno(gerrno)
|
|
}
|
|
return nil, &DNSError{Err: err.Error(), Name: addr}, true
|
|
}
|
|
|
|
for i := 0; i < len(b); i++ {
|
|
if b[i] == 0 {
|
|
b = b[:i]
|
|
break
|
|
}
|
|
}
|
|
return []string{absDomainName(b)}, nil, true
|
|
}
|
|
|
|
func cgoSockaddr(ip IP, zone string) (*syscall.RawSockaddr, syscall.Socklen_t) {
|
|
if ip4 := ip.To4(); ip4 != nil {
|
|
return cgoSockaddrInet4(ip4), syscall.Socklen_t(syscall.SizeofSockaddrInet4)
|
|
}
|
|
if ip6 := ip.To16(); ip6 != nil {
|
|
return cgoSockaddrInet6(ip6, zoneToInt(zone)), syscall.Socklen_t(syscall.SizeofSockaddrInet6)
|
|
}
|
|
return nil, 0
|
|
}
|
|
|
|
func copyIP(x IP) IP {
|
|
if len(x) < 16 {
|
|
return x.To16()
|
|
}
|
|
y := make(IP, len(x))
|
|
copy(y, x)
|
|
return y
|
|
}
|