Implement CAA

TODO.markdown

@@ -14,3 +14,18 @@
 * Speed, we can always go faster. A simple reflect server now hits 45/50K qps
 * go test; only works correct on my machine
 * privatekey.Precompute() when signing? 
+
+## RR not implemented
+
+These are deprecated, or rarely used (or just a bitch to implement).
+
+NSAP
+NSAP-PTR
+PX
+GPOS
+NIMLOC
+ATMA
+A6
+KEY
+SIG
+(maybe more)

types.go

@@ -491,7 +491,7 @@ type TXT struct {
 }
 
 func (rr *TXT) Header() *RR_Header { return &rr.Hdr }
-func (rr *TXT) copy() RR           { return &TXT{*rr.Hdr.copyHeader(), rr.Txt} }
+func (rr *TXT) copy() RR           { return &TXT{*rr.Hdr.copyHeader(), rr.Txt} } // this doesn't really copy Txt does it? (TODO?(mg))
 
 func (rr *TXT) String() string {
 	s := rr.Hdr.String()
@@ -1408,6 +1408,36 @@ func (rr *EUI64) len() int {
 	return rr.Hdr.len() + 8
 }
 
+type CAA struct {
+	Hdr   RR_Header
+	Flag  uint8
+	Tag   string
+	Value []string `dns:"txt"`
+}
+
+func (rr *CAA) Header() *RR_Header { return &rr.Hdr }
+func (rr *CAA) copy() RR           { return &CAA{*rr.Hdr.copyHeader(), rr.Flag, rr.Tag, rr.Value} }
+
+func (rr *CAA) String() string {
+	s := rr.Hdr.String() + strconv.FormatInt(int64(rr.Flag), 10) + " " + rr.Tag
+	for i, s1 := range rr.Value {
+		if i > 0 {
+			s += " " + strconv.QuoteToASCII(s1)
+		} else {
+			s += strconv.QuoteToASCII(s1)
+		}
+	}
+	return s
+}
+
+func (rr *CAA) len() int {
+	l := rr.Hdr.len() + 1 + len(rr.Tag)
+	for _, t := range rr.Value {
+		l += len(t)
+	}
+	return l
+}
+
 // TimeToString translates the RRSIG's incep. and expir. times to the
 // string representation used when printing the record.
 // It takes serial arithmetic (RFC 1982) into account.
@@ -1530,4 +1560,5 @@ var rr_mk = map[uint16]func() RR{
 	TypeLP:         func() RR { return new(LP) },
 	TypeEUI48:      func() RR { return new(EUI48) },
 	TypeEUI64:      func() RR { return new(EUI64) },
+	TypeCAA:        func() RR { return new(CAA) },
 }