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
}