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Merge branch 'master' of github.com:miekg/dns

This commit is contained in:
Miek Gieben 2014-10-06 10:58:03 +00:00
parent ce9b1fdbf8 d05369e629
commit 06e7420b3e
12 changed files with 500 additions and 58 deletions
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1
CONTRIBUTORS
View File

@ -6,3 +6,4 @@ Dusty Wilson
Marek Majkowski
Peter van Dijk
Omri Bahumi
Alex Sergeyev

3
README.md
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@ -34,7 +34,8 @@ A not-so-up-to-date-list-that-may-be-actually-current:
* https://github.com/skynetservices/skydns
* https://github.com/DevelopersPL/godnsagent
* https://github.com/duedil-ltd/discodns
* ... (send pull request if you want to be listed here)
Send pull request if you want to be listed here.
# Features

33
edns.go
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@ -35,16 +35,16 @@ import (
// EDNS0 Option codes.
const (
EDNS0LLQ = 0x1 // long lived queries: http://tools.ietf.org/html/draft-sekar-dns-llq-01
EDNS0UL = 0x2 // update lease draft: http://files.dns-sd.org/draft-sekar-dns-ul.txt
EDNS0NSID = 0x3 // nsid (RFC5001)
EDNS0DAU = 0x5 // DNSSEC Algorithm Understood
EDNS0DHU = 0x6 // DS Hash Understood
EDNS0N3U = 0x7 // NSEC3 Hash Understood
EDNS0SUBNET = 0x8 // client-subnet (RFC6891)
EDNS0EXPIRE = 0x9 // EDNS0 expire
EDNS0SUBNETDRAFT = 0x50fa // Don't use! Use EDNS0SUBNET
_DO = 1 << 7 // dnssec ok
EDNS0LLQ = 0x1 // long lived queries: http://tools.ietf.org/html/draft-sekar-dns-llq-01
EDNS0UL = 0x2 // update lease draft: http://files.dns-sd.org/draft-sekar-dns-ul.txt
EDNS0NSID = 0x3 // nsid (RFC5001)
EDNS0DAU = 0x5 // DNSSEC Algorithm Understood
EDNS0DHU = 0x6 // DS Hash Understood
EDNS0N3U = 0x7 // NSEC3 Hash Understood
EDNS0SUBNET = 0x8 // client-subnet (RFC6891)
EDNS0EXPIRE = 0x9 // EDNS0 expire
EDNS0SUBNETDRAFT = 0x50fa // Don't use! Use EDNS0SUBNET
_DO = 1 << 15 // dnssec ok
)
type OPT struct {
@ -114,12 +114,12 @@ func (rr *OPT) copy() RR {
// Version returns the EDNS version used. Only zero is defined.
func (rr *OPT) Version() uint8 {
return uint8(rr.Hdr.Ttl & 0x00FF00FFFF)
return uint8((rr.Hdr.Ttl & 0x00FF0000) >> 16)
}
// SetVersion sets the version of EDNS. This is usually zero.
func (rr *OPT) SetVersion(v uint8) {
rr.Hdr.Ttl = rr.Hdr.Ttl&0xFF00FFFF | uint32(v)
rr.Hdr.Ttl = rr.Hdr.Ttl&0xFF00FFFF | (uint32(v) << 16)
}
// UDPSize returns the UDP buffer size.
@ -134,17 +134,12 @@ func (rr *OPT) SetUDPSize(size uint16) {
// Do returns the value of the DO (DNSSEC OK) bit.
func (rr *OPT) Do() bool {
return byte(rr.Hdr.Ttl>>8)&_DO == _DO
return rr.Hdr.Ttl&_DO == _DO
}
// SetDo sets the DO (DNSSEC OK) bit.
func (rr *OPT) SetDo() {
b1 := byte(rr.Hdr.Ttl >> 24)
b2 := byte(rr.Hdr.Ttl >> 16)
b3 := byte(rr.Hdr.Ttl >> 8)
b4 := byte(rr.Hdr.Ttl)
b3 |= _DO // Set it
rr.Hdr.Ttl = uint32(b1)<<24 | uint32(b2)<<16 | uint32(b3)<<8 | uint32(b4)
rr.Hdr.Ttl |= _DO
}
// EDNS0 defines an EDNS0 Option. An OPT RR can have multiple options appended to

34
edns_test.go Normal file
View File

@ -0,0 +1,34 @@
package dns
import "testing"
func TestOPTTtl(t *testing.T) {
e := &OPT{}
e.Hdr.Name = "."
e.Hdr.Rrtype = TypeOPT
if e.Do() {
t.Fail()
}
e.SetDo()
if !e.Do() {
t.Fail()
}
oldTtl := e.Hdr.Ttl
if e.Version() != 0 {
t.Fail()
}
e.SetVersion(42)
if e.Version() != 42 {
t.Fail()
}
e.SetVersion(0)
if e.Hdr.Ttl != oldTtl {
t.Fail()
}
}

122
example_test.go
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@ -1,25 +1,29 @@
package dns
package dns_test
import (
"errors"
"fmt"
"github.com/miekg/dns"
"log"
"net"
)
// Retrieve the MX records for miek.nl.
func ExampleMX() {
config, _ := ClientConfigFromFile("/etc/resolv.conf")
c := new(Client)
m := new(Msg)
m.SetQuestion("miek.nl.", TypeMX)
config, _ := dns.ClientConfigFromFile("/etc/resolv.conf")
c := new(dns.Client)
m := new(dns.Msg)
m.SetQuestion("miek.nl.", dns.TypeMX)
m.RecursionDesired = true
r, _, err := c.Exchange(m, config.Servers[0]+":"+config.Port)
if err != nil {
return
}
if r.Rcode != RcodeSuccess {
if r.Rcode != dns.RcodeSuccess {
return
}
for _, a := range r.Answer {
if mx, ok := a.(*MX); ok {
if mx, ok := a.(*dns.MX); ok {
fmt.Printf("%s\n", mx.String())
}
}
@ -28,26 +32,116 @@ func ExampleMX() {
// Retrieve the DNSKEY records of a zone and convert them
// to DS records for SHA1, SHA256 and SHA384.
func ExampleDS(zone string) {
config, _ := ClientConfigFromFile("/etc/resolv.conf")
c := new(Client)
m := new(Msg)
config, _ := dns.ClientConfigFromFile("/etc/resolv.conf")
c := new(dns.Client)
m := new(dns.Msg)
if zone == "" {
zone = "miek.nl"
}
m.SetQuestion(Fqdn(zone), TypeDNSKEY)
m.SetQuestion(dns.Fqdn(zone), dns.TypeDNSKEY)
m.SetEdns0(4096, true)
r, _, err := c.Exchange(m, config.Servers[0]+":"+config.Port)
if err != nil {
return
}
if r.Rcode != RcodeSuccess {
if r.Rcode != dns.RcodeSuccess {
return
}
for _, k := range r.Answer {
if key, ok := k.(*DNSKEY); ok {
for _, alg := range []int{SHA1, SHA256, SHA384} {
if key, ok := k.(*dns.DNSKEY); ok {
for _, alg := range []int{dns.SHA1, dns.SHA256, dns.SHA384} {
fmt.Printf("%s; %d\n", key.ToDS(alg).String(), key.Flags)
}
}
}
}
const TypeAPAIR = 0x0F99
type APAIR struct {
addr [2]net.IP
}
func NewAPAIR() dns.PrivateRdata { return new(APAIR) }
func (rd *APAIR) String() string { return rd.addr[0].String() + " " + rd.addr[1].String() }
func (rd *APAIR) Parse(txt []string) error {
if len(txt) != 2 {
return errors.New("two addresses required for APAIR")
}
for i, s := range txt {
ip := net.ParseIP(s)
if ip == nil {
return errors.New("invalid IP in APAIR text representation")
}
rd.addr[i] = ip
}
return nil
}
func (rd *APAIR) Pack(buf []byte) (int, error) {
b := append([]byte(rd.addr[0]), []byte(rd.addr[1])...)
n := copy(buf, b)
if n != len(b) {
return n, dns.ErrBuf
}
return n, nil
}
func (rd *APAIR) Unpack(buf []byte) (int, error) {
ln := net.IPv4len * 2
if len(buf) != ln {
return 0, errors.New("invalid length of APAIR rdata")
}
cp := make([]byte, ln)
copy(cp, buf) // clone bytes to use them in IPs
rd.addr[0] = net.IP(cp[:3])
rd.addr[1] = net.IP(cp[4:])
return len(buf), nil
}
func (rd *APAIR) Copy(dest dns.PrivateRdata) error {
cp := make([]byte, rd.Len())
_, err := rd.Pack(cp)
if err != nil {
return err
}
d := dest.(*APAIR)
d.addr[0] = net.IP(cp[:3])
d.addr[1] = net.IP(cp[4:])
return nil
}
func (rd *APAIR) Len() int {
return net.IPv4len * 2
}
func ExamplePrivateHandle() {
dns.PrivateHandle("APAIR", TypeAPAIR, NewAPAIR)
defer dns.PrivateHandleRemove(TypeAPAIR)
rr, err := dns.NewRR("miek.nl. APAIR (1.2.3.4 1.2.3.5)")
if err != nil {
log.Fatal("could not parse APAIR record: ", err)
}
fmt.Println(rr)
// Output: miek.nl. 3600 IN APAIR 1.2.3.4 1.2.3.5
m := new(dns.Msg)
m.Id = 12345
m.SetQuestion("miek.nl.", TypeAPAIR)
m.Answer = append(m.Answer, rr)
fmt.Println(m)
// ;; opcode: QUERY, status: NOERROR, id: 12345
// ;; flags: rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
//
// ;; QUESTION SECTION:
// ;miek.nl. IN APAIR
//
// ;; ANSWER SECTION:
// miek.nl. 3600 IN APAIR 1.2.3.4 1.2.3.5
}

6
labels.go
View File

@ -4,7 +4,9 @@ package dns
// SplitDomainName splits a name string into it's labels.
// www.miek.nl. returns []string{"www", "miek", "nl"}
// The root label (.) returns nil.
// The root label (.) returns nil. Note that using
// strings.Split(s) will work in most cases, but does not handle
// escaped dots (\.) for instance.
func SplitDomainName(s string) (labels []string) {
if len(s) == 0 {
return nil
@ -101,7 +103,7 @@ func CountLabel(s string) (labels int) {
// Split splits a name s into its label indexes.
// www.miek.nl. returns []int{0, 4, 9}, www.miek.nl also returns []int{0, 4, 9}.
// The root name (.) returns nil.
// The root name (.) returns nil. Also see dns.SplitDomainName.
func Split(s string) []int {
if s == "." {
return nil

26
msg.go
View File

@ -576,6 +576,19 @@ func packStructValue(val reflect.Value, msg []byte, off int, compression map[str
switch fv := val.Field(i); fv.Kind() {
default:
return lenmsg, &Error{err: "bad kind packing"}
case reflect.Interface:
// PrivateRR is the only RR implementation that has interface field.
// therefore it's expected that this interface would be PrivateRdata
switch data := fv.Interface().(type) {
case PrivateRdata:
n, err := data.Pack(msg[off:])
if err != nil {
return lenmsg, err
}
off += n
default:
return lenmsg, &Error{err: "bad kind interface packing"}
}
case reflect.Slice:
switch typefield.Tag {
default:
@ -869,6 +882,19 @@ func unpackStructValue(val reflect.Value, msg []byte, off int) (off1 int, err er
switch fv := val.Field(i); fv.Kind() {
default:
return lenmsg, &Error{err: "bad kind unpacking"}
case reflect.Interface:
// PrivateRR is the only RR implementation that has interface field.
// therefore it's expected that this interface would be PrivateRdata
switch data := fv.Interface().(type) {
case PrivateRdata:
n, err := data.Unpack(msg[off:rdend])
if err != nil {
return lenmsg, err
}
off += n
default:
return lenmsg, &Error{err: "bad kind interface unpacking"}
}
case reflect.Slice:
switch val.Type().Field(i).Tag {
default:

2
parse_test.db
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@ -1,2 +0,0 @@
a.example.com. IN A 127.0.0.1
8db7._openpgpkey.example.com. IN OPENPGPKEY mQCNAzIG

17
parse_test.go
View File

@ -7,7 +7,6 @@ import (
"fmt"
"math/rand"
"net"
"os"
"reflect"
"strconv"
"strings"
@ -563,13 +562,17 @@ func TestParseFailure(t *testing.T) {
}
func TestZoneParsing(t *testing.T) {
f, err := os.Open("parse_test.db")
if err != nil {
return
}
defer f.Close()
// parse_test.db
db := `
a.example.com. IN A 127.0.0.1
8db7._openpgpkey.example.com. IN OPENPGPKEY mQCNAzIG
$ORIGIN a.example.com.
test IN A 127.0.0.1
$ORIGIN b.example.com.
test IN CNAME test.a.example.com.
`
start := time.Now().UnixNano()
to := ParseZone(f, "", "parse_test.db")
to := ParseZone(strings.NewReader(db), "", "parse_test.db")
var i int
for x := range to {
i++

122
privaterr.go Normal file
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@ -0,0 +1,122 @@
/*
PRIVATE RR
RFC 6895 sets aside a range of type codes for private use. This range
is 65,280 - 65,534 (0xFF00 - 0xFFFE). When experimenting with new Resource Records these
can be used, before requesting an official type code from IANA.
*/
package dns
import (
"fmt"
"strings"
)
// PrivateRdata is an interface used for implementing "Private Use" RR types, see
// RFC 6895. This allows one to experiment with new RR types, without requesting an
// official type code. Also see dns.PrivateHandle and dns.PrivateHandleRemove.
type PrivateRdata interface {
// String returns the text presentaton of the Rdata of the Private RR.
String() string
// Parse parses the Rdata of the private RR.
Parse([]string) error
// Pack is used when packing a private RR into a buffer.
Pack([]byte) (int, error)
// Unpack is used when unpacking a private RR from a buffer.
// TODO(miek): diff. signature than Pack, see edns0.go for instance.
Unpack([]byte) (int, error)
// Copy copies the Rdata.
Copy(PrivateRdata) error
// Len returns the length in octets of the Rdata.
Len() int
}
// PrivateRR represents an RR that uses a PrivateRdata user-defined type.
// It mocks normal RRs and implements dns.RR interface.
type PrivateRR struct {
Hdr RR_Header
Data PrivateRdata
}
func mkPrivateRR(rrtype uint16) *PrivateRR {
// Panics if RR is not an instance of PrivateRR.
rrfunc, ok := typeToRR[rrtype]
if !ok {
panic(fmt.Sprintf("dns: invalid operation with Private RR type %d", rrtype))
}
anyrr := rrfunc()
switch rr := anyrr.(type) {
case *PrivateRR:
return rr
}
panic(fmt.Sprintf("dns: RR is not a PrivateRR, typeToRR[%d] generator returned %T", rrtype, anyrr))
}
func (r *PrivateRR) Header() *RR_Header { return &r.Hdr }
func (r *PrivateRR) String() string { return r.Hdr.String() + r.Data.String() }
// Private len and copy parts to satisfy RR interface.
func (r *PrivateRR) len() int { return r.Hdr.len() + r.Data.Len() }
func (r *PrivateRR) copy() RR {
// make new RR like this:
rr := mkPrivateRR(r.Hdr.Rrtype)
newh := r.Hdr.copyHeader()
rr.Hdr = *newh
err := r.Data.Copy(rr.Data)
if err != nil {
panic("dns: got value that could not be used to copy Private rdata")
}
return rr
}
// PrivateHandle registers a private resource record type. It requires
// string and numeric representation of private RR type and generator function as argument.
func PrivateHandle(rtypestr string, rtype uint16, generator func() PrivateRdata) {
rtypestr = strings.ToUpper(rtypestr)
typeToRR[rtype] = func() RR { return &PrivateRR{RR_Header{}, generator()} }
TypeToString[rtype] = rtypestr
StringToType[rtypestr] = rtype
setPrivateRR := func(h RR_Header, c chan lex, o, f string) (RR, *ParseError, string) {
rr := mkPrivateRR(h.Rrtype)
rr.Hdr = h
var l lex
text := make([]string, 0, 2) // could be 0..N elements, median is probably 1
FETCH:
for {
// TODO(miek): we could also be returning _QUOTE, this might or might not
// be an issue (basically parsing TXT becomes hard)
switch l = <-c; l.value {
case _NEWLINE, _EOF:
break FETCH
case _STRING:
text = append(text, l.token)
}
}
err := rr.Data.Parse(text)
if err != nil {
return nil, &ParseError{f, err.Error(), l}, ""
}
return rr, nil, ""
}
typeToparserFunc[rtype] = parserFunc{setPrivateRR, true}
}
// PrivateHandleRemove removes defenitions required to support private RR type.
func PrivateHandleRemove(rtype uint16) {
rtypestr, ok := TypeToString[rtype]
if ok {
delete(typeToRR, rtype)
delete(TypeToString, rtype)
delete(typeToparserFunc, rtype)
delete(StringToType, rtypestr)
}
return
}

169
privaterr_test.go Normal file
View File

@ -0,0 +1,169 @@
package dns_test
import (
"github.com/miekg/dns"
"strings"
"testing"
)
const TypeISBN uint16 = 0x0F01
// A crazy new RR type :)
type ISBN struct {
x string // rdata with 10 or 13 numbers, dashes or spaces allowed
}
func NewISBN() dns.PrivateRdata { return &ISBN{""} }
func (rd *ISBN) Len() int { return len([]byte(rd.x)) }
func (rd *ISBN) String() string { return rd.x }
func (rd *ISBN) Parse(txt []string) error {
rd.x = strings.TrimSpace(strings.Join(txt, " "))
return nil
}
func (rd *ISBN) Pack(buf []byte) (int, error) {
b := []byte(rd.x)
n := copy(buf, b)
if n != len(b) {
return n, dns.ErrBuf
}
return n, nil
}
func (rd *ISBN) Unpack(buf []byte) (int, error) {
rd.x = string(buf)
return len(buf), nil
}
func (rd *ISBN) Copy(dest dns.PrivateRdata) error {
isbn, ok := dest.(*ISBN)
if !ok {
return dns.ErrRdata
}
isbn.x = rd.x
return nil
}
var testrecord = strings.Join([]string{"example.org.", "3600", "IN", "ISBN", "12-3 456789-0-123"}, "\t")
func TestPrivateText(t *testing.T) {
dns.PrivateHandle("ISBN", TypeISBN, NewISBN)
defer dns.PrivateHandleRemove(TypeISBN)
rr, err := dns.NewRR(testrecord)
if err != nil {
t.Fatal(err)
}
if rr.String() != testrecord {
t.Errorf("record string representation did not match original %#v != %#v", rr.String(), testrecord)
} else {
t.Log(rr.String())
}
}
func TestPrivateByteSlice(t *testing.T) {
dns.PrivateHandle("ISBN", TypeISBN, NewISBN)
defer dns.PrivateHandleRemove(TypeISBN)
rr, err := dns.NewRR(testrecord)
if err != nil {
t.Fatal(err)
}
buf := make([]byte, 100)
off, err := dns.PackRR(rr, buf, 0, nil, false)
if err != nil {
t.Errorf("got error packing ISBN: %s", err)
}
custrr := rr.(*dns.PrivateRR)
if ln := custrr.Data.Len() + len(custrr.Header().Name) + 11; ln != off {
t.Errorf("offset is not matching to length of Private RR: %d!=%d", off, ln)
}
rr1, off1, err := dns.UnpackRR(buf[:off], 0)
if err != nil {
t.Errorf("got error unpacking ISBN: %s", err)
}
if off1 != off {
t.Errorf("Offset after unpacking differs: %d != %d", off1, off)
}
if rr1.String() != testrecord {
t.Errorf("Record string representation did not match original %#v != %#v", rr1.String(), testrecord)
} else {
t.Log(rr1.String())
}
}
const TypeVERSION uint16 = 0x0F02
type VERSION struct {
x string
}
func NewVersion() dns.PrivateRdata { return &VERSION{""} }
func (rd *VERSION) String() string { return rd.x }
func (rd *VERSION) Parse(txt []string) error {
rd.x = strings.TrimSpace(strings.Join(txt, " "))
return nil
}
func (rd *VERSION) Pack(buf []byte) (int, error) {
b := []byte(rd.x)
n := copy(buf, b)
if n != len(b) {
return n, dns.ErrBuf
}
return n, nil
}
func (rd *VERSION) Unpack(buf []byte) (int, error) {
rd.x = string(buf)
return len(buf), nil
}
func (rd *VERSION) Copy(dest dns.PrivateRdata) error {
isbn, ok := dest.(*VERSION)
if !ok {
return dns.ErrRdata
}
isbn.x = rd.x
return nil
}
func (rd *VERSION) Len() int {
return len([]byte(rd.x))
}
var smallzone = `$ORIGIN example.org.
@ SOA sns.dns.icann.org. noc.dns.icann.org. (
2014091518 7200 3600 1209600 3600
)
A 1.2.3.4
ok ISBN 1231-92110-12
go VERSION (
1.3.1 ; comment
)
www ISBN 1231-92110-16
* CNAME @
`
func TestPrivateZoneParser(t *testing.T) {
dns.PrivateHandle("ISBN", TypeISBN, NewISBN)
dns.PrivateHandle("VERSION", TypeVERSION, NewVersion)
defer dns.PrivateHandleRemove(TypeISBN)
defer dns.PrivateHandleRemove(TypeVERSION)
r := strings.NewReader(smallzone)
for x := range dns.ParseZone(r, ".", "") {
if err := x.Error; err != nil {
t.Fatal(err)
}
t.Log(x.RR)
}
}

23
zscan_rr.go
View File

@ -24,23 +24,20 @@ type parserFunc struct {
// or immediately a _NEWLINE. If this is not the case we flag
// an *ParseError: garbage after rdata.
func setRR(h RR_Header, c chan lex, o, f string) (RR, *ParseError, string) {
var r RR
e := new(ParseError)
parserfunc, ok := typeToparserFunc[h.Rrtype]
if ok {
r, e, cm := parserfunc.Func(h, c, o, f)
if parserfunc.Variable {
r, e, _ = parserfunc.Func(h, c, o, f)
if e != nil {
return nil, e, ""
}
se, com := slurpRemainder(c, f)
if se != nil {
return nil, se, ""
}
return r, e, com
return r, e, cm
}
return parserfunc.Func(h, c, o, f)
if e != nil {
return nil, e, ""
}
e, cm = slurpRemainder(c, f)
if e != nil {
return nil, e, ""
}
return r, nil, cm
}
// RFC3957 RR (Unknown RR handling)
return setRFC3597(h, c, o, f)