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Skip reflection for most types (#369) 

Make the reflection types a black list (these types use (or should use)
the tag 'size-xxx' in their struct definition.s

HIP, IPSECKEY, NSEC3, TSIG

All other types don't use reflection anymore.

* Return a pointer to the header when there is no rdata, this restores old
  behavior. The rest of the conversion mostly hangs on getting size-hex
  right, but then packStruct and packStructValue and the unpack variant
  can be killed.
* Generate pack and unpack for all embedded types as well.
* Fix PrivateRRs, register an unpack function as well, when you register
  a new PrivateRR.
* Add the tag octet, nsec, []domains and more  to msg_helper.go
This commit is contained in:
Miek Gieben 2016-06-12 16:09:37 +01:00 committed by GitHub
parent 331ecbbc51
commit 6ae3b9f061
6 changed files with 966 additions and 254 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

176
msg.go
View File

@ -588,35 +588,6 @@ func packStructValue(val reflect.Value, msg []byte, off int, compression map[str
return lenmsg, err
}
}
case `dns:"txt"`:
if txtTmp == nil {
txtTmp = make([]byte, 256*4+1)
}
off, err = packTxt(fv.Interface().([]string), msg, off, txtTmp)
if err != nil {
return lenmsg, err
}
case `dns:"opt"`: // edns
for j := 0; j < val.Field(i).Len(); j++ {
element := val.Field(i).Index(j).Interface()
b, err := element.(EDNS0).pack()
if err != nil || off+3 > lenmsg {
return lenmsg, &Error{err: "overflow packing opt"}
}
// Option code
binary.BigEndian.PutUint16(msg[off:], element.(EDNS0).Option())
// Length
binary.BigEndian.PutUint16(msg[off+2:], uint16(len(b)))
off += 4
if off+len(b) > lenmsg {
copy(msg[off:], b)
off = lenmsg
continue
}
// Actual data
copy(msg[off:off+len(b)], b)
off += len(b)
}
case `dns:"a"`:
if val.Type().String() == "dns.IPSECKEY" {
// Field(2) is GatewayType, must be 1
@ -899,108 +870,6 @@ func unpackStructValue(val reflect.Value, msg []byte, off int) (off1 int, err er
servers = append(servers, s)
}
fv.Set(reflect.ValueOf(servers))
case `dns:"txt"`:
if off == lenmsg {
break
}
var txt []string
txt, off, err = unpackTxt(msg, off)
if err != nil {
return lenmsg, err
}
fv.Set(reflect.ValueOf(txt))
case `dns:"opt"`: // edns0
if off == lenmsg {
// This is an EDNS0 (OPT Record) with no rdata
// We can safely return here.
break
}
var edns []EDNS0
Option:
code := uint16(0)
if off+4 > lenmsg {
return lenmsg, &Error{err: "overflow unpacking opt"}
}
code = binary.BigEndian.Uint16(msg[off:])
off += 2
optlen := binary.BigEndian.Uint16(msg[off:])
off1 := off + 2
if off1+int(optlen) > lenmsg {
return lenmsg, &Error{err: "overflow unpacking opt"}
}
switch code {
case EDNS0NSID:
e := new(EDNS0_NSID)
if err := e.unpack(msg[off1 : off1+int(optlen)]); err != nil {
return lenmsg, err
}
edns = append(edns, e)
off = off1 + int(optlen)
case EDNS0SUBNET, EDNS0SUBNETDRAFT:
e := new(EDNS0_SUBNET)
if err := e.unpack(msg[off1 : off1+int(optlen)]); err != nil {
return lenmsg, err
}
edns = append(edns, e)
off = off1 + int(optlen)
if code == EDNS0SUBNETDRAFT {
e.DraftOption = true
}
case EDNS0COOKIE:
e := new(EDNS0_COOKIE)
if err := e.unpack(msg[off1 : off1+int(optlen)]); err != nil {
return lenmsg, err
}
edns = append(edns, e)
off = off1 + int(optlen)
case EDNS0UL:
e := new(EDNS0_UL)
if err := e.unpack(msg[off1 : off1+int(optlen)]); err != nil {
return lenmsg, err
}
edns = append(edns, e)
off = off1 + int(optlen)
case EDNS0LLQ:
e := new(EDNS0_LLQ)
if err := e.unpack(msg[off1 : off1+int(optlen)]); err != nil {
return lenmsg, err
}
edns = append(edns, e)
off = off1 + int(optlen)
case EDNS0DAU:
e := new(EDNS0_DAU)
if err := e.unpack(msg[off1 : off1+int(optlen)]); err != nil {
return lenmsg, err
}
edns = append(edns, e)
off = off1 + int(optlen)
case EDNS0DHU:
e := new(EDNS0_DHU)
if err := e.unpack(msg[off1 : off1+int(optlen)]); err != nil {
return lenmsg, err
}
edns = append(edns, e)
off = off1 + int(optlen)
case EDNS0N3U:
e := new(EDNS0_N3U)
if err := e.unpack(msg[off1 : off1+int(optlen)]); err != nil {
return lenmsg, err
}
edns = append(edns, e)
off = off1 + int(optlen)
default:
e := new(EDNS0_LOCAL)
e.Code = code
if err := e.unpack(msg[off1 : off1+int(optlen)]); err != nil {
return lenmsg, err
}
edns = append(edns, e)
off = off1 + int(optlen)
}
if off < lenmsg {
goto Option
}
fv.Set(reflect.ValueOf(edns))
case `dns:"a"`:
if val.Type().String() == "dns.IPSECKEY" {
// Field(2) is GatewayType, must be 1
@ -1296,11 +1165,10 @@ func PackRR(rr RR, msg []byte, off int, compression map[string]int, compress boo
return len(msg), &Error{err: "nil rr"}
}
_, ok := typeToUnpack[rr.Header().Rrtype]
_, ok := blacklist[rr.Header().Rrtype]
switch ok {
case true:
case false:
off1, err = rr.pack(msg, off, compression, compress)
// TODO(miek): revert the logic and make a blacklist for types that still use reflection. Kill typeToUnpack.
default:
off1, err = packStructCompress(rr, msg, off, compression, compress)
}
@ -1322,14 +1190,17 @@ func UnpackRR(msg []byte, off int) (rr RR, off1 int, err error) {
}
end := off + int(h.Rdlength)
fn, ok := typeToUnpack[h.Rrtype]
_, ok := blacklist[h.Rrtype]
switch ok {
case true:
case false:
// Shortcut reflection.
rr, off, err = fn(h, msg, off)
if fn, known := typeToUnpack[h.Rrtype]; !known {
rr, off, err = unpackRFC3597(h, msg, off)
} else {
rr, off, err = fn(h, msg, off)
}
default:
mk, known := TypeToRR[h.Rrtype]
if !known {
if mk, known := TypeToRR[h.Rrtype]; !known {
rr = new(RFC3597)
} else {
rr = mk()
@ -1982,25 +1853,10 @@ func unpackMsgHdr(msg []byte, off int) (Header, int, error) {
return dh, off, err
}
// Which types have type specific unpack functions.
var typeToUnpack = map[uint16]func(RR_Header, []byte, int) (RR, int, error){
TypeAAAA: unpackAAAA,
TypeA: unpackA,
TypeCNAME: unpackCNAME,
TypeDNAME: unpackDNAME,
TypeL32: unpackL32,
TypeLOC: unpackLOC,
TypeMB: unpackMB,
TypeMD: unpackMD,
TypeMF: unpackMF,
TypeMG: unpackMG,
TypeMR: unpackMR,
TypeMX: unpackMX,
TypeNID: unpackNID,
TypeNS: unpackNS,
TypePTR: unpackPTR,
TypeRP: unpackRP,
TypeSRV: unpackSRV,
TypeHINFO: unpackHINFO,
TypeDNSKEY: unpackDNSKEY,
// Which types do no work reflectionless yet.
var blacklist = map[uint16]bool{
TypeHIP: true,
TypeIPSECKEY: true,
TypeNSEC3: true,
TypeTSIG: true,
}

71
msg_generate.go
View File

@ -16,17 +16,11 @@ import (
"os"
)
// All RR pack and unpack functions should be generated, currently RR that present some
// problems
// * NSEC/NSEC3 - type bitmap
// * TXT/SPF - string slice
// * URI - weird octet thing there
// * NSEC3/TSIG - size hex
// * OPT RR - EDNS0 parsing - needs to some looking at
// All RR pack and unpack functions should be generated, currently RR that present some problems
// * NSEC3 - size hex
// * TSIG - size hex
// * HIP - uses "hex", but is actually size-hex - might drop size-hex?
// * Z
// * NINFO
// * PrivateRR
// * IPSECKEY -
var packageHdr = `
// *** DO NOT MODIFY ***
@ -90,10 +84,7 @@ func main() {
fmt.Fprint(b, "// pack*() functions\n\n")
for _, name := range namedTypes {
o := scope.Lookup(name)
st, isEmbedded := getTypeStruct(o.Type(), scope)
if isEmbedded {
continue
}
st, _ := getTypeStruct(o.Type(), scope)
fmt.Fprintf(b, "func (rr *%s) pack(msg []byte, off int, compression map[string]int, compress bool) (int, error) {\n", name)
fmt.Fprint(b, `off, err := rr.Hdr.pack(msg, off, compression, compress)
@ -113,19 +104,23 @@ return off, err
if _, ok := st.Field(i).Type().(*types.Slice); ok {
switch st.Tag(i) {
case `dns:"-"`:
// ignored
case `dns:"-"`: // ignored
case `dns:"txt"`:
o("off, err = packStringTxt(rr.%s, msg, off)\n")
case `dns:"opt"`:
o("off, err = packDataOpt(rr.%s, msg, off)\n")
case `dns:"nsec"`:
o("off, err = packDataNsec(rr.%s, msg, off)\n")
case `dns:"domain-name"`:
o("off, err = packDataDomainNames(rr.%s, msg, off, compression, compress)\n")
default:
//log.Fatalln(name, st.Field(i).Name(), st.Tag(i))
log.Fatalln(name, st.Field(i).Name(), st.Tag(i))
}
continue
}
switch st.Tag(i) {
case `dns:"-"`:
// ignored
case `dns:"-"`: // ignored
case `dns:"cdomain-name"`:
fallthrough
case `dns:"domain-name"`:
@ -142,6 +137,10 @@ return off, err
o("off, err = packStringBase32(rr.%s, msg, off)\n")
case `dns:"base64"`:
o("off, err = packStringBase64(rr.%s, msg, off)\n")
case `dns:"hex"`:
o("off, err = packStringHex(rr.%s, msg, off)\n")
case `dns:"octet"`:
o("off, err = packStringOctet(rr.%s, msg, off)\n")
case "":
switch st.Field(i).Type().(*types.Basic).Kind() {
case types.Uint8:
@ -169,14 +168,11 @@ return off, err
fmt.Fprint(b, "// unpack*() functions\n\n")
for _, name := range namedTypes {
o := scope.Lookup(name)
st, isEmbedded := getTypeStruct(o.Type(), scope)
if isEmbedded {
continue
}
st, _ := getTypeStruct(o.Type(), scope)
fmt.Fprintf(b, "func unpack%s(h RR_Header, msg []byte, off int) (RR, int, error) {\n", name)
fmt.Fprint(b, `if noRdata(h) {
return nil, off, nil
return &h, off, nil
}
var err error
rdStart := off
@ -196,19 +192,23 @@ return rr, off, err
if _, ok := st.Field(i).Type().(*types.Slice); ok {
switch st.Tag(i) {
case `dns:"-"`:
// ignored
case `dns:"-"`: // ignored
case `dns:"txt"`:
o("rr.%s, off, err = unpackStringTxt(msg, off)\n")
case `dns:"opt"`:
o("rr.%s, off, err = unpackDataOpt(msg, off)\n")
case `dns:"nsec"`:
o("rr.%s, off, err = unpackDataNsec(msg, off)\n")
case `dns:"domain-name"`:
o("rr.%s, off, err = unpackDataDomainNames(msg, off, rdStart + int(rr.Hdr.Rdlength))\n")
default:
//log.Fatalln(name, st.Field(i).Name(), st.Tag(i))
log.Fatalln(name, st.Field(i).Name(), st.Tag(i))
}
continue
}
switch st.Tag(i) {
case `dns:"-"`:
// ignored
case `dns:"-"`: // ignored
case `dns:"cdomain-name"`:
fallthrough
case `dns:"domain-name"`:
@ -225,6 +225,10 @@ return rr, off, err
o("rr.%s, off, err = unpackStringBase32(msg, off, rdStart + int(rr.Hdr.Rdlength))\n")
case `dns:"base64"`:
o("rr.%s, off, err = unpackStringBase64(msg, off, rdStart + int(rr.Hdr.Rdlength))\n")
case `dns:"hex"`:
o("rr.%s, off, err = unpackStringHex(msg, off, rdStart + int(rr.Hdr.Rdlength))\n")
case `dns:"octet"`:
o("rr.%s, off, err = unpackStringOctet(msg, off)\n")
case "":
switch st.Field(i).Type().(*types.Basic).Kind() {
case types.Uint8:
@ -253,6 +257,15 @@ return rr, off, nil
}
fmt.Fprintf(b, "return rr, off, err }\n\n")
}
// Generate typeToUnpack map
fmt.Fprintln(b, "var typeToUnpack = map[uint16]func(RR_Header, []byte, int) (RR, int, error){")
for _, name := range namedTypes {
if name == "RFC3597" {
continue
}
fmt.Fprintf(b, "Type%s: unpack%s,\n", name, name)
}
fmt.Fprintln(b, "}\n")
// gofmt
res, err := format.Source(b.Bytes())

248
msg_helpers.go
View File

@ -359,3 +359,251 @@ func packStringTxt(s []string, msg []byte, off int) (int, error) {
}
return off, nil
}
func unpackDataOpt(msg []byte, off int) ([]EDNS0, int, error) {
var edns []EDNS0
Option:
code := uint16(0)
if off+4 > len(msg) {
return nil, len(msg), &Error{err: "overflow unpacking opt"}
}
code = binary.BigEndian.Uint16(msg[off:])
off += 2
optlen := binary.BigEndian.Uint16(msg[off:])
off += 2
if off+int(optlen) > len(msg) {
return nil, len(msg), &Error{err: "overflow unpacking opt"}
}
switch code {
case EDNS0NSID:
e := new(EDNS0_NSID)
if err := e.unpack(msg[off : off+int(optlen)]); err != nil {
return nil, len(msg), err
}
edns = append(edns, e)
off += int(optlen)
case EDNS0SUBNET, EDNS0SUBNETDRAFT:
e := new(EDNS0_SUBNET)
if err := e.unpack(msg[off : off+int(optlen)]); err != nil {
return nil, len(msg), err
}
edns = append(edns, e)
off += int(optlen)
if code == EDNS0SUBNETDRAFT {
e.DraftOption = true
}
case EDNS0COOKIE:
e := new(EDNS0_COOKIE)
if err := e.unpack(msg[off : off+int(optlen)]); err != nil {
return nil, len(msg), err
}
edns = append(edns, e)
off += int(optlen)
case EDNS0UL:
e := new(EDNS0_UL)
if err := e.unpack(msg[off : off+int(optlen)]); err != nil {
return nil, len(msg), err
}
edns = append(edns, e)
off += int(optlen)
case EDNS0LLQ:
e := new(EDNS0_LLQ)
if err := e.unpack(msg[off : off+int(optlen)]); err != nil {
return nil, len(msg), err
}
edns = append(edns, e)
off += int(optlen)
case EDNS0DAU:
e := new(EDNS0_DAU)
if err := e.unpack(msg[off : off+int(optlen)]); err != nil {
return nil, len(msg), err
}
edns = append(edns, e)
off += int(optlen)
case EDNS0DHU:
e := new(EDNS0_DHU)
if err := e.unpack(msg[off : off+int(optlen)]); err != nil {
return nil, len(msg), err
}
edns = append(edns, e)
off += int(optlen)
case EDNS0N3U:
e := new(EDNS0_N3U)
if err := e.unpack(msg[off : off+int(optlen)]); err != nil {
return nil, len(msg), err
}
edns = append(edns, e)
off += int(optlen)
default:
e := new(EDNS0_LOCAL)
e.Code = code
if err := e.unpack(msg[off : off+int(optlen)]); err != nil {
return nil, len(msg), err
}
edns = append(edns, e)
off += int(optlen)
}
if off < len(msg) {
goto Option
}
return edns, off, nil
}
func packDataOpt(options []EDNS0, msg []byte, off int) (int, error) {
for _, el := range options {
b, err := el.pack()
if err != nil || off+3 > len(msg) {
return len(msg), &Error{err: "overflow packing opt"}
}
binary.BigEndian.PutUint16(msg[off:], el.Option()) // Option code
binary.BigEndian.PutUint16(msg[off+2:], uint16(len(b))) // Length
off += 4
if off+len(b) > len(msg) {
copy(msg[off:], b)
off = len(msg)
continue
}
// Actual data
copy(msg[off:off+len(b)], b)
off += len(b)
}
return off, nil
}
func unpackStringOctet(msg []byte, off int) (string, int, error) {
s := string(msg[off:])
return s, len(msg), nil
}
func packStringOctet(s string, msg []byte, off int) (int, error) {
txtTmp := make([]byte, 256*4+1)
off, err := packOctetString(s, msg, off, txtTmp)
if err != nil {
return len(msg), err
}
return off, nil
}
func unpackDataNsec(msg []byte, off int) ([]uint16, int, error) {
var nsec []uint16
length, window, lastwindow := 0, 0, -1
for off < len(msg) {
if off+2 > len(msg) {
return nsec, len(msg), &Error{err: "overflow unpacking nsecx"}
}
window = int(msg[off])
length = int(msg[off+1])
off += 2
if window <= lastwindow {
// RFC 4034: Blocks are present in the NSEC RR RDATA in
// increasing numerical order.
return nsec, len(msg), &Error{err: "out of order NSEC block"}
}
if length == 0 {
// RFC 4034: Blocks with no types present MUST NOT be included.
return nsec, len(msg), &Error{err: "empty NSEC block"}
}
if length > 32 {
return nsec, len(msg), &Error{err: "NSEC block too long"}
}
if off+length > len(msg) {
return nsec, len(msg), &Error{err: "overflowing NSEC block"}
}
// Walk the bytes in the window and extract the type bits
for j := 0; j < length; j++ {
b := msg[off+j]
// Check the bits one by one, and set the type
if b&0x80 == 0x80 {
nsec = append(nsec, uint16(window*256+j*8+0))
}
if b&0x40 == 0x40 {
nsec = append(nsec, uint16(window*256+j*8+1))
}
if b&0x20 == 0x20 {
nsec = append(nsec, uint16(window*256+j*8+2))
}
if b&0x10 == 0x10 {
nsec = append(nsec, uint16(window*256+j*8+3))
}
if b&0x8 == 0x8 {
nsec = append(nsec, uint16(window*256+j*8+4))
}
if b&0x4 == 0x4 {
nsec = append(nsec, uint16(window*256+j*8+5))
}
if b&0x2 == 0x2 {
nsec = append(nsec, uint16(window*256+j*8+6))
}
if b&0x1 == 0x1 {
nsec = append(nsec, uint16(window*256+j*8+7))
}
}
off += length
lastwindow = window
}
return nsec, off, nil
}
func packDataNsec(bitmap []uint16, msg []byte, off int) (int, error) {
if len(bitmap) == 0 {
return off, nil
}
var lastwindow, lastlength uint16
for j := 0; j < len(bitmap); j++ {
t := bitmap[j]
window := t / 256
length := (t-window*256)/8 + 1
if window > lastwindow && lastlength != 0 { // New window, jump to the new offset
off += int(lastlength) + 2
lastlength = 0
}
if window < lastwindow || length < lastlength {
return len(msg), &Error{err: "nsec bits out of order"}
}
if off+2+int(length) > len(msg) {
return len(msg), &Error{err: "overflow packing nsec"}
}
// Setting the window #
msg[off] = byte(window)
// Setting the octets length
msg[off+1] = byte(length)
// Setting the bit value for the type in the right octet
msg[off+1+int(length)] |= byte(1 << (7 - (t % 8)))
lastwindow, lastlength = window, length
}
off += int(lastlength) + 2
return off, nil
}
func unpackDataDomainNames(msg []byte, off, end int) ([]string, int, error) {
var (
servers []string
s string
err error
)
if end > len(msg) {
return nil, len(msg), &Error{err: "overflow unpacking domain names"}
}
for off < end {
s, off, err = UnpackDomainName(msg, off)
if err != nil {
return servers, len(msg), err
}
servers = append(servers, s)
}
return servers, off, nil
}
func packDataDomainNames(names []string, msg []byte, off int, compression map[string]int, compress bool) (int, error) {
var err error
for j := 0; j < len(names); j++ {
off, err = PackDomainName(names[j], msg, off, compression, false && compress)
if err != nil {
return len(msg), err
}
}
return off, nil
}

28
privaterr.go
View File

@ -66,11 +66,17 @@ func (r *PrivateRR) copy() RR {
return rr
}
func (r *PrivateRR) pack(msg []byte, off int, compression map[string]int, compress bool) (int, error) {
off, err := r.Hdr.pack(msg, off, compression, compress)
if err != nil {
return off, err
}
headerEnd := off
n, err := r.Data.Pack(msg[off:])
if err != nil {
return len(msg), err
}
off += n
r.Header().Rdlength = uint16(off - headerEnd)
return off, nil
}
@ -83,19 +89,36 @@ func PrivateHandle(rtypestr string, rtype uint16, generator func() PrivateRdata)
TypeToString[rtype] = rtypestr
StringToType[rtypestr] = rtype
typeToUnpack[rtype] = func(h RR_Header, msg []byte, off int) (RR, int, error) {
if noRdata(h) {
return &h, off, nil
}
var err error
rr := mkPrivateRR(h.Rrtype)
rr.Hdr = h
off1, err := rr.Data.Unpack(msg[off:])
off += off1
if err != nil {
return rr, off, err
}
return rr, off, err
}
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:
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 zNewline, zEOF:
break FETCH
break Fetch
case zString:
text = append(text, l.token)
}
@ -120,6 +143,7 @@ func PrivateHandleRemove(rtype uint16) {
delete(TypeToString, rtype)
delete(typeToparserFunc, rtype)
delete(StringToType, rtypestr)
delete(typeToUnpack, rtype)
}
return
}

1
privaterr_test.go
View File

@ -87,6 +87,7 @@ func TestPrivateByteSlice(t *testing.T) {
rr1, off1, err := dns.UnpackRR(buf[:off], 0)
if err != nil {
t.Errorf("got error unpacking ISBN: %v", err)
return
}
if off1 != off {

696
zmsg.go
View File

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