Subversion Repositories openrisc

// 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 darwin freebsd linux

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])
}

func cgoLookupHost(name string) (addrs []string, err error, completed bool) {
        ip, err, completed := cgoLookupIP(name)
        for _, p := range ip {
                addrs = append(addrs, p.String())
        }
        return
}

func cgoLookupPort(net, service string) (port int, err error, completed bool) {
        var res *syscall.Addrinfo
        var hints syscall.Addrinfo

        switch net {
        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, UnknownNetworkError(net), true
        }
        if len(net) >= 4 {
                switch net[3] {
                case '4':
                        hints.Ai_family = syscall.AF_INET
                case '6':
                        hints.Ai_family = syscall.AF_INET6
                }
        }

        s := syscall.StringBytePtr(service)
        if libc_getaddrinfo(nil, s, &hints, &res) == 0 {
                defer libc_freeaddrinfo(res)
                for r := res; r != nil; r = r.Ai_next {
                        switch r.Ai_family {
                        default:
                                continue
                        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, &AddrError{"unknown port", net + "/" + service}, true
}

func cgoLookupIPCNAME(name string) (addrs []IP, cname string, err error, completed bool) {
        var res *syscall.Addrinfo
        var hints syscall.Addrinfo

        // NOTE(rsc): In theory there are approximately balanced
        // arguments for and against including AI_ADDRCONFIG
        // in the flags (it includes IPv4 results only on IPv4 systems,
        // and similarly for IPv6), but in practice setting it causes
        // getaddrinfo to return the wrong canonical name on Linux.
        // So definitely leave it out.
        hints.Ai_flags = int32((syscall.AI_ALL | syscall.AI_V4MAPPED | syscall.AI_CANONNAME) & cgoAddrInfoMask())

        h := syscall.StringBytePtr(name)
        gerrno := libc_getaddrinfo(h, nil, &hints, &res)
        if gerrno != 0 {
                var str string
                if gerrno == syscall.EAI_NONAME {
                        str = noSuchHost
                } else if gerrno == syscall.EAI_SYSTEM {
                        str = syscall.GetErrno().Error()
                } else {
                        str = bytePtrToString(libc_gai_strerror(gerrno))
                }
                return nil, "", &DNSError{Err: str, 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 {
                // Everything comes back twice, once for UDP and once for TCP.
                if r.Ai_socktype != syscall.SOCK_STREAM {
                        continue
                }
                switch r.Ai_family {
                default:
                        continue
                case syscall.AF_INET:
                        sa := (*syscall.RawSockaddrInet4)(unsafe.Pointer(r.Ai_addr))
                        addrs = append(addrs, copyIP(sa.Addr[:]))
                case syscall.AF_INET6:
                        sa := (*syscall.RawSockaddrInet6)(unsafe.Pointer(r.Ai_addr))
                        addrs = append(addrs, copyIP(sa.Addr[:]))
                }
        }
        return addrs, cname, nil, true
}

func cgoLookupIP(name string) (addrs []IP, 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
}

func copyIP(x IP) IP {
        y := make(IP, len(x))
        copy(y, x)
        return y
}