diff options
Diffstat (limited to 'vendor/github.com/miekg/dns/dns.go')
-rw-r--r-- | vendor/github.com/miekg/dns/dns.go | 99 |
1 files changed, 75 insertions, 24 deletions
diff --git a/vendor/github.com/miekg/dns/dns.go b/vendor/github.com/miekg/dns/dns.go index 5133eac..a88484b 100644 --- a/vendor/github.com/miekg/dns/dns.go +++ b/vendor/github.com/miekg/dns/dns.go @@ -1,6 +1,9 @@ package dns -import "strconv" +import ( + "encoding/hex" + "strconv" +) const ( year68 = 1 << 31 // For RFC1982 (Serial Arithmetic) calculations in 32 bits. @@ -34,10 +37,30 @@ type RR interface { // copy returns a copy of the RR copy() RR - // len returns the length (in octets) of the uncompressed RR in wire format. - len() int - // pack packs an RR into wire format. - pack([]byte, int, map[string]int, bool) (int, error) + + // len returns the length (in octets) of the compressed or uncompressed RR in wire format. + // + // If compression is nil, the uncompressed size will be returned, otherwise the compressed + // size will be returned and domain names will be added to the map for future compression. + len(off int, compression map[string]struct{}) int + + // pack packs the records RDATA into wire format. The header will + // already have been packed into msg. + pack(msg []byte, off int, compression compressionMap, compress bool) (off1 int, err error) + + // unpack unpacks an RR from wire format. + // + // This will only be called on a new and empty RR type with only the header populated. It + // will only be called if the record's RDATA is non-empty. + unpack(msg []byte, off int) (off1 int, err error) + + // parse parses an RR from zone file format. + // + // This will only be called on a new and empty RR type with only the header populated. + parse(c *zlexer, origin string) *ParseError + + // isDuplicate returns whether the two RRs are duplicates. + isDuplicate(r2 RR) bool } // RR_Header is the header all DNS resource records share. @@ -55,16 +78,6 @@ func (h *RR_Header) Header() *RR_Header { return h } // Just to implement the RR interface. func (h *RR_Header) copy() RR { return nil } -func (h *RR_Header) copyHeader() *RR_Header { - r := new(RR_Header) - r.Name = h.Name - r.Rrtype = h.Rrtype - r.Class = h.Class - r.Ttl = h.Ttl - r.Rdlength = h.Rdlength - return r -} - func (h *RR_Header) String() string { var s string @@ -80,28 +93,66 @@ func (h *RR_Header) String() string { return s } -func (h *RR_Header) len() int { - l := len(h.Name) + 1 +func (h *RR_Header) len(off int, compression map[string]struct{}) int { + l := domainNameLen(h.Name, off, compression, true) l += 10 // rrtype(2) + class(2) + ttl(4) + rdlength(2) return l } +func (h *RR_Header) pack(msg []byte, off int, compression compressionMap, compress bool) (off1 int, err error) { + // RR_Header has no RDATA to pack. + return off, nil +} + +func (h *RR_Header) unpack(msg []byte, off int) (int, error) { + panic("dns: internal error: unpack should never be called on RR_Header") +} + +func (h *RR_Header) parse(c *zlexer, origin string) *ParseError { + panic("dns: internal error: parse should never be called on RR_Header") +} + // ToRFC3597 converts a known RR to the unknown RR representation from RFC 3597. func (rr *RFC3597) ToRFC3597(r RR) error { - buf := make([]byte, r.len()*2) - off, err := PackRR(r, buf, 0, nil, false) + buf := make([]byte, Len(r)) + headerEnd, off, err := packRR(r, buf, 0, compressionMap{}, false) if err != nil { return err } buf = buf[:off] - if int(r.Header().Rdlength) > off { - return ErrBuf + + *rr = RFC3597{Hdr: *r.Header()} + rr.Hdr.Rdlength = uint16(off - headerEnd) + + if noRdata(rr.Hdr) { + return nil } - rfc3597, _, err := unpackRFC3597(*r.Header(), buf, off-int(r.Header().Rdlength)) + _, err = rr.unpack(buf, headerEnd) + return err +} + +// fromRFC3597 converts an unknown RR representation from RFC 3597 to the known RR type. +func (rr *RFC3597) fromRFC3597(r RR) error { + hdr := r.Header() + *hdr = rr.Hdr + + // Can't overflow uint16 as the length of Rdata is validated in (*RFC3597).parse. + // We can only get here when rr was constructed with that method. + hdr.Rdlength = uint16(hex.DecodedLen(len(rr.Rdata))) + + if noRdata(*hdr) { + // Dynamic update. + return nil + } + + // rr.pack requires an extra allocation and a copy so we just decode Rdata + // manually, it's simpler anyway. + msg, err := hex.DecodeString(rr.Rdata) if err != nil { return err } - *rr = *rfc3597.(*RFC3597) - return nil + + _, err = r.unpack(msg, 0) + return err } |