2010-12-30 23:42:52 +11:00
|
|
|
// 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.
|
|
|
|
// Extended and bugfixes by Miek Gieben
|
|
|
|
|
|
|
|
// Package dns implements a full featured interface to the DNS.
|
|
|
|
// Supported RFCs and features include:
|
2011-01-09 05:10:47 +11:00
|
|
|
// * 1034/1035 - DNS standard
|
2010-12-31 00:13:28 +11:00
|
|
|
// * 1982 - Serial Arithmetic
|
2010-12-31 06:50:31 +11:00
|
|
|
// * 1876 - LOC record (incomplete)
|
2011-01-01 00:11:52 +11:00
|
|
|
// * 1995 - IXFR
|
2011-01-02 06:01:49 +11:00
|
|
|
// * 1996 - DNS notify
|
2011-01-09 05:10:47 +11:00
|
|
|
// * 2537 - RSAMD5 DNS keys
|
2010-12-30 23:42:52 +11:00
|
|
|
// * 2671 - EDNS
|
2011-01-01 01:10:42 +11:00
|
|
|
// * 2845 - TSIG
|
2010-12-31 06:50:31 +11:00
|
|
|
// * 2915 - NAPTR record (incomplete)
|
2011-01-09 05:10:47 +11:00
|
|
|
// * 3110 - RSASHA1 DNS keys
|
2010-12-31 04:42:40 +11:00
|
|
|
// * 3225 - DO bit (DNSSEC OK)
|
2010-12-30 23:42:52 +11:00
|
|
|
// * 4033/4034/4035 - DNSSEC + validation functions
|
2010-12-31 00:13:28 +11:00
|
|
|
// * 5011 - NSID
|
2011-01-01 00:11:52 +11:00
|
|
|
// * 5936 - AXFR
|
2010-12-30 23:42:52 +11:00
|
|
|
// * IP6 support
|
2011-01-02 06:01:49 +11:00
|
|
|
//
|
2010-12-30 23:42:52 +11:00
|
|
|
// The package allows full control over what is send out to the DNS.
|
|
|
|
//
|
|
|
|
package dns
|
|
|
|
|
2010-12-31 06:50:31 +11:00
|
|
|
import (
|
|
|
|
"strconv"
|
2011-01-12 09:33:07 +11:00
|
|
|
"os"
|
|
|
|
"net"
|
2010-12-31 06:50:31 +11:00
|
|
|
)
|
2010-12-30 23:42:52 +11:00
|
|
|
|
|
|
|
const Year68 = 2 << (32 - 1)
|
|
|
|
|
2011-01-03 21:29:04 +11:00
|
|
|
type Error struct {
|
2011-01-02 04:47:38 +11:00
|
|
|
Error string
|
|
|
|
Name string
|
|
|
|
Server string
|
2011-01-03 21:29:04 +11:00
|
|
|
Timeout bool
|
2011-01-02 04:47:38 +11:00
|
|
|
}
|
|
|
|
|
2011-01-03 21:29:04 +11:00
|
|
|
func (e *Error) String() string {
|
2011-01-02 04:47:38 +11:00
|
|
|
if e == nil {
|
|
|
|
return "<nil>"
|
|
|
|
}
|
|
|
|
return e.Error
|
|
|
|
}
|
|
|
|
|
2010-12-30 23:42:52 +11:00
|
|
|
type RR interface {
|
2010-12-31 06:50:31 +11:00
|
|
|
Header() *RR_Header
|
|
|
|
String() string
|
2010-12-30 23:42:52 +11:00
|
|
|
}
|
|
|
|
|
|
|
|
// An RRset is a slice of RRs.
|
|
|
|
type RRset []RR
|
|
|
|
|
|
|
|
func (r RRset) Len() int { return len(r) }
|
|
|
|
func (r RRset) Less(i, j int) bool { return r[i].Header().Name < r[j].Header().Name }
|
|
|
|
func (r RRset) Swap(i, j int) { r[i], r[j] = r[j], r[i] }
|
|
|
|
|
|
|
|
// DNS resource records.
|
|
|
|
// There are many types of messages,
|
|
|
|
// but they all share the same header.
|
|
|
|
type RR_Header struct {
|
2010-12-31 06:50:31 +11:00
|
|
|
Name string "domain-name"
|
|
|
|
Rrtype uint16
|
|
|
|
Class uint16
|
|
|
|
Ttl uint32
|
|
|
|
Rdlength uint16 // length of data after header
|
2010-12-30 23:42:52 +11:00
|
|
|
}
|
|
|
|
|
|
|
|
func (h *RR_Header) Header() *RR_Header {
|
2010-12-31 06:50:31 +11:00
|
|
|
return h
|
2010-12-30 23:42:52 +11:00
|
|
|
}
|
|
|
|
|
|
|
|
func (h *RR_Header) String() string {
|
2010-12-31 06:50:31 +11:00
|
|
|
var s string
|
2010-12-30 23:42:52 +11:00
|
|
|
|
2010-12-31 06:50:31 +11:00
|
|
|
if h.Rrtype == TypeOPT {
|
|
|
|
s = ";"
|
|
|
|
// and maybe other things
|
|
|
|
}
|
2010-12-30 23:42:52 +11:00
|
|
|
|
2010-12-31 06:50:31 +11:00
|
|
|
if len(h.Name) == 0 {
|
|
|
|
s += ".\t"
|
|
|
|
} else {
|
|
|
|
s += h.Name + "\t"
|
|
|
|
}
|
|
|
|
s = s + strconv.Itoa(int(h.Ttl)) + "\t"
|
|
|
|
s = s + Class_str[h.Class] + "\t"
|
|
|
|
s = s + Rr_str[h.Rrtype] + "\t"
|
|
|
|
return s
|
2010-12-30 23:42:52 +11:00
|
|
|
}
|
|
|
|
|
2011-01-12 09:33:07 +11:00
|
|
|
func SendTCP(c net.Conn, m []byte) os.Error {
|
|
|
|
l := make([]byte, 2)
|
|
|
|
l[0] = byte(len(m) >> 8)
|
|
|
|
l[1] = byte(len(m))
|
|
|
|
// First we send the length
|
|
|
|
_, err := c.Write(l)
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
// And the the message
|
|
|
|
_, err = c.Write(m)
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
return nil
|
|
|
|
}
|
2010-12-30 23:42:52 +11:00
|
|
|
|
2011-01-12 09:33:07 +11:00
|
|
|
func RecvTCP(c net.Conn) ([]byte, os.Error) {
|
|
|
|
l := make([]byte, 2) // receiver length
|
|
|
|
// The server replies with two bytes length
|
|
|
|
_, err := c.Read(l)
|
|
|
|
if err != nil {
|
|
|
|
return nil,err
|
|
|
|
}
|
|
|
|
length := uint16(l[0])<<8 | uint16(l[1])
|
|
|
|
if length == 0 {
|
|
|
|
return nil, &Error{Error: "received nil msg length", Server: c.RemoteAddr().String()}
|
|
|
|
}
|
|
|
|
m := make([]byte, length)
|
|
|
|
n, cerr := c.Read(m)
|
|
|
|
if cerr != nil {
|
|
|
|
return nil, cerr
|
|
|
|
}
|
|
|
|
i := n
|
|
|
|
if i < int(length) {
|
|
|
|
n, err = c.Read(m[i:])
|
|
|
|
if err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
i += n
|
|
|
|
}
|
|
|
|
return m, nil
|
|
|
|
}
|
|
|
|
|
|
|
|
// Or expose the pack/unpack functions??
|
2011-01-09 20:34:29 +11:00
|
|
|
// These were created for dnssec.go, but now that
|
2011-01-12 09:33:07 +11:00
|
|
|
// that package is included again in dns, they are
|
|
|
|
// not really needed. These will be removed asap.
|
2010-12-31 00:13:28 +11:00
|
|
|
// Return the wiredata of rdata portion of a RR.
|
2010-12-30 23:42:52 +11:00
|
|
|
func WireRdata(r RR) ([]byte, bool) {
|
2010-12-31 06:50:31 +11:00
|
|
|
buf := make([]byte, 4096) // Too large, need to FIX TODO(mg)
|
|
|
|
off1, ok := packRR(r, buf, 0)
|
|
|
|
if !ok {
|
|
|
|
return nil, false
|
|
|
|
}
|
|
|
|
start := off1 - int(r.Header().Rdlength)
|
|
|
|
end := start + int(r.Header().Rdlength)
|
|
|
|
buf = buf[start:end]
|
|
|
|
return buf, true
|
2010-12-30 23:42:52 +11:00
|
|
|
}
|
|
|
|
|
2010-12-31 00:13:28 +11:00
|
|
|
// Return the wiredata of a domainname (sans compressions).
|
2010-12-30 23:42:52 +11:00
|
|
|
func WireDomainName(s string) ([]byte, bool) {
|
2010-12-31 06:50:31 +11:00
|
|
|
buf := make([]byte, 255)
|
|
|
|
off, ok := packDomainName(s, buf, 0)
|
|
|
|
if !ok {
|
|
|
|
return nil, ok
|
|
|
|
}
|
|
|
|
buf = buf[:off]
|
|
|
|
return buf, ok
|
2010-12-30 23:42:52 +11:00
|
|
|
}
|
|
|
|
|
2010-12-31 00:13:28 +11:00
|
|
|
// Return the wiredata of a complete Resource Record.
|
2010-12-30 23:42:52 +11:00
|
|
|
func WireRR(r RR) ([]byte, bool) {
|
2010-12-31 06:50:31 +11:00
|
|
|
buf := make([]byte, 4096)
|
|
|
|
off, ok := packRR(r, buf, 0)
|
|
|
|
if !ok {
|
|
|
|
return nil, false
|
|
|
|
}
|
|
|
|
buf = buf[:off]
|
|
|
|
return buf, ok
|
2010-12-30 23:42:52 +11:00
|
|
|
}
|