Subversion Repositories openrisc

// 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 (

        "os"

        "sync"

        "syscall"

        "unsafe"

)

var (

        protoentLock sync.Mutex

        hostentLock  sync.Mutex

        serventLock  sync.Mutex

)

// lookupProtocol looks up IP protocol name and returns correspondent protocol number.

func lookupProtocol(name string) (proto int, err error) {

        protoentLock.Lock()

        defer protoentLock.Unlock()

        p, err := syscall.GetProtoByName(name)

        if err != nil {

                return 0, os.NewSyscallError("GetProtoByName", err)

        }

        return int(p.Proto), nil

}

func lookupHost(name string) (addrs []string, err error) {

        ips, err := LookupIP(name)

        if err != nil {

                return

        }

        addrs = make([]string, 0, len(ips))

        for _, ip := range ips {

                addrs = append(addrs, ip.String())

        }

        return

}

func lookupIP(name string) (addrs []IP, err error) {

        hostentLock.Lock()

        defer hostentLock.Unlock()

        h, err := syscall.GetHostByName(name)

        if err != nil {

                return nil, os.NewSyscallError("GetHostByName", err)

        }

        switch h.AddrType {

        case syscall.AF_INET:

                i := 0

                addrs = make([]IP, 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])

                }

                addrs = addrs[0:i]

        default: // TODO(vcc): Implement non IPv4 address lookups.

                return nil, os.NewSyscallError("LookupHost", syscall.EWINDOWS)

        }

        return addrs, nil

}

func lookupPort(network, service string) (port int, err error) {

        switch network {

        case "tcp4", "tcp6":

                network = "tcp"

        case "udp4", "udp6":

                network = "udp"

        }

        serventLock.Lock()

        defer serventLock.Unlock()

        s, err := syscall.GetServByName(service, network)

        if err != nil {

                return 0, os.NewSyscallError("GetServByName", err)

        }

        return int(syscall.Ntohs(s.Port)), nil

}

func lookupCNAME(name string) (cname string, err error) {

        var r *syscall.DNSRecord

        e := syscall.DnsQuery(name, syscall.DNS_TYPE_CNAME, 0, nil, &r, nil)

        if e != nil {

                return "", os.NewSyscallError("LookupCNAME", e)

        }

        defer syscall.DnsRecordListFree(r, 1)

        if r != nil && r.Type == syscall.DNS_TYPE_CNAME {

                v := (*syscall.DNSPTRData)(unsafe.Pointer(&r.Data[0]))

                cname = syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:]) + "."

        }

        return

}

func lookupSRV(service, proto, name string) (cname string, addrs []*SRV, err error) {

        var target string

        if service == "" && proto == "" {

                target = name

        } else {

                target = "_" + service + "._" + proto + "." + name

        }

        var r *syscall.DNSRecord

        e := syscall.DnsQuery(target, syscall.DNS_TYPE_SRV, 0, nil, &r, nil)

        if e != nil {

                return "", nil, os.NewSyscallError("LookupSRV", e)

        }

        defer syscall.DnsRecordListFree(r, 1)

        addrs = make([]*SRV, 0, 10)

        for p := r; p != nil && p.Type == syscall.DNS_TYPE_SRV; p = p.Next {

                v := (*syscall.DNSSRVData)(unsafe.Pointer(&p.Data[0]))

                addrs = append(addrs, &SRV{syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Target))[:]), v.Port, v.Priority, v.Weight})

        }

        byPriorityWeight(addrs).sort()

        return name, addrs, nil

}

func lookupMX(name string) (mx []*MX, err error) {

        var r *syscall.DNSRecord

        e := syscall.DnsQuery(name, syscall.DNS_TYPE_MX, 0, nil, &r, nil)

        if e != nil {

                return nil, os.NewSyscallError("LookupMX", e)

        }

        defer syscall.DnsRecordListFree(r, 1)

        mx = make([]*MX, 0, 10)

        for p := r; p != nil && p.Type == syscall.DNS_TYPE_MX; p = p.Next {

                v := (*syscall.DNSMXData)(unsafe.Pointer(&p.Data[0]))

                mx = append(mx, &MX{syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.NameExchange))[:]) + ".", v.Preference})

        }

        byPref(mx).sort()

        return mx, nil

}

func lookupTXT(name string) (txt []string, err error) {

        var r *syscall.DNSRecord

        e := syscall.DnsQuery(name, syscall.DNS_TYPE_TEXT, 0, nil, &r, nil)

        if e != nil {

                return nil, os.NewSyscallError("LookupTXT", e)

        }

        defer syscall.DnsRecordListFree(r, 1)

        txt = make([]string, 0, 10)

        if r != nil && r.Type == syscall.DNS_TYPE_TEXT {

                d := (*syscall.DNSTXTData)(unsafe.Pointer(&r.Data[0]))

                for _, v := range (*[1 << 10]*uint16)(unsafe.Pointer(&(d.StringArray[0])))[:d.StringCount] {

                        s := syscall.UTF16ToString((*[1 << 20]uint16)(unsafe.Pointer(v))[:])

                        txt = append(txt, s)

                }

        }

        return

}

func lookupAddr(addr string) (name []string, err error) {

        arpa, err := reverseaddr(addr)

        if err != nil {

                return nil, err

        }

        var r *syscall.DNSRecord

        e := syscall.DnsQuery(arpa, syscall.DNS_TYPE_PTR, 0, nil, &r, nil)

        if e != nil {

                return nil, os.NewSyscallError("LookupAddr", e)

        }

        defer syscall.DnsRecordListFree(r, 1)

        name = make([]string, 0, 10)

        for p := r; p != nil && p.Type == syscall.DNS_TYPE_PTR; p = p.Next {

                v := (*syscall.DNSPTRData)(unsafe.Pointer(&p.Data[0]))

                name = append(name, syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:]))

        }

        return name, nil

}