John R Levine <jo...@taugh.com> wrote: > > That's the eventual plan, although there is a long tail of funky field types > found only in RRs that nobody uses any more.
When I looked at this in 2012 I concluded that the best approach would be to keep the generic language REALLY simple, and that RDATA with special needs would have to have a custom-coded parser/serializer. There were three memorable problems: (1) RDATA where the field order was not consistent between wire format and presentation format, e.g. LOC (2) RDATA with variable format, e.g. IPSECKEY (3) RDATA with variable number of fields, e.g. APL, NSEC It's MUCH easier to define an abstract syntax if the RDATA has a fixed number of fields in a fixed order, which is consistent in all formats. > I have some funding to implement it, so I'm doing the useful parts first to > see if I run into unexpected problems. It took about 15 minutes to realize > that it needs to let you name the fields as well as describe them, if you want > to refer to the fields from other code. Yes! And field names are really crucial if you want to be able to auto-generate user interfaces from the abstract syntax, because you can use the field names as a key for localization and for help text. Very sketchy dump of old ideas after the break.... Tony. -- f.anthony.n.finch <d...@dotat.at> http://dotat.at/ - I xn--zr8h punycode Humber, Thames, Dover, Wight: Variable 3 or 4. Smooth or slight. Fog patches. Moderate, occasionally very poor. The following includes a failed attempt to incorporate enumerations into the abstract syntax, which makes it more complicated than I would like, but I think enums are vital for autogenerated user interfaces. ; types ; ; name ; text ; uint8 ; uint16 ; uint32 ; time (uint32 with variant presentation format) ; ipv4 ; ipv6 ; flags16 ; base64 (whitespace allowed) ; hex (no whitespace allowed) ; unknown ; rrtype ; bitlist ; qualifiers ; ; name ; host ; mail ; compressed ; decompress ; additional ; uint32 ; interval (BIND extension) ; bitlist ; port ; rrtype ; text ; multiple define uint8 algo [http://www.iana.org/assignments/dns-sec-alg-numbers/dns-sec-alg-numbers.xml] 1 RSAMD5 - 2 DH - 3 DSA - 5 RSASHA1 - 6 DSA-NSEC3-SHA1 - 7 RSASHA1-NSEC3-SHA1 - 8 RSASHA256 - 10 RSASHA512 - 12 ECC-GOST - 13 ECDSAP256SHA256 - 14 ECDSAP384SHA384 - 252 INDIRECT - 252 PRIVATEDNS - 253 PRIVATEOID - TYPE1 A IPv4 address [RFC1035] ipv4 ADDRESS - TYPE2 NS Name server [RFC1035] name NSDNAME Host name host additional compressed TYPE3 MD Mail destination (OBSOLETE - use MX) [RFC1035] name MADNAME Mail agent host name host additional compressed TYPE4 MF Mail forwarder (OBSOLETE - use MX) [RFC1035] name MADNAME Mail agent host name host additional compressed TYPE5 CNAME Alias [RFC1035] name CNAME Canonical name compressed TYPE6 SOA Start of zone of authority [RFC1035] name MNAME Master name server host compressed name RNAME Hostmaster email address mail compressed uint32 SERIAL Zone serial number uint32 REFRESH Refresh interval interval uint32 RETRY Retry interval interval uint32 EXPIRE Slave copy lifetime interval uint32 MINIMUM Negative response TTL interval TYPE7 MB Mailbox (OBSOLETE - use MX) [RFC1035] name MADNAME Mail agent host name host additional compressed TYPE8 MG Mail group (OBSOLETE - use MX) [RFC1035] name MGNAME Group member email address mail compressed TYPE9 MR Mail rename (OBSOLETE - use MX) [RFC1035] name NEWNAME Replacement email address mail compressed TYPE10 NULL Meaningless data [RFC1035] TYPE11 WKS Well known service (OBSOLETE) [RFC1035] ipv4 ADDRESS Host address uint16 PROTOCOL Protocol 6 TCP - 17 UDP - bitlist - Bit map of open ports TYPE12 PTR Pointer from reverse DNS [RFC1035] name PTRDNAME Forward DNS name host compressed ; is host flag correct? TYPE13 HINFO Host information [RFC1035] text CPU - text OS - TYPE14 MINFO Mail information (OBSOLETE - use MX) [RFC1035] name RMAILBX Responsible person email address mail compressed name EMAILBX Error email address mail compressed TYPE15 MX Mail exchanger [RFC1035] uint16 PREFERENCE Preference (lower values tried first) name EXCHANGE Mail exchange host name host additional compressed TYPE16 TXT Text [RFC1035] text TXT-DATA - multiple TYPE17 RP Responsible person [RFC1183] name MBOX-DNAME Email address mail decompress name TXT-DNAME Pointer to TXT records decompress TYPE18 AFSDB AFS database location [RFC1183] uint16 SUBTYPE - 1 - AFSv3 volume location server 2 - cell root directory node name HOSTNAME - host additional decompress TYPE19 X25 X.25 PSDN address (OBSOLETE) [RFC1183] text PSDN-ADDRESS - TYPE20 ISDN ISDN address (OBSOLETE) [RFC1183] text ISDN-ADDRESS Telephone number text SA Subaddress optional TYPE21 RT Route through [RFC1183] uint16 PREFERENCE Preference (lower values tried first) name INTERMEDIATE-HOST Intermediate host name host additional decompress TYPE22 NSAP ISO NSAP address (OBSOLETE) [RFC1706] ; hex NSAP-ADDRESS - ; with 0x prefix and optional dots TYPE23 NSAP-PTR ISO NSAP reverse pointer (OBSOLETE - use PTR) [RFC1348] name OWNER - decompress TYPE24 SIG Cryptographic signature (OBSOLETE) [RFC2535] rrtype TYPE-COVERED Type covered algo ALGORITHM Signature algorithm uint8 LABELS Non-wildcard label count uint32 ORIG-TTL Original TTL interval time EXPIRATION Expiration time time INCEPTION Inception time uint16 KEY-TAG Key tag name SIGNER Key name decompress base64 SIGNATURE Signature data TYPE25 KEY Cryptographic key [RFC2535] flags16 FLAGS Flags 49152 A-C Key restrictions 49152 NOKEY No key present 32769 NOAUTH Not for authentication 16384 NOCONF Not for encryption 4096 EXTEND Extended flags 768 NAMTYP Owner type 768 OTHER - 512 HOST - 256 ZONE - 0 USER - 15 SIG Signatory [RFC2137] 8 ZONE Zone control 4 STRONG Strong update 2 UNIQUE Unique name update 1 GENERAL General update uint8 PROTOCOL Protocol 1 TLS - 2 EMAIL - 3 DNSSEC - 4 IPSEC - 255 ALL - algo ALGORITHM Algorithm base64 PUBLIC-KEY Public key data TYPE26 PX X.400 mail gateway [RFC2163] uint16 PREFERENCE Preference (lower values tried first) name MAP822 - decompress name MAPX400 - decompress TYPE27 GPOS Geographical Position [RFC1712] text LONGITUDE - text LATITUDE - text ALTITUDE - TYPE28 AAAA IPv6 address [RFC3596] ipv6 ADDRESS - TYPE29 LOC Location [RFC1876] ; uint8 VERSION Must be 0 ; float8 SIZE Diameter ; float8 HORIZ-PRE Horizontal precision ; float8 VERT-PRE Vertical precision ; angle LATITUDE Latitude ; N,S ; angle LONGITURE Longitude ; E,W ; altitude ALTITUDE Altitude ; ; angle is uint32 thousandths of a second of arc plus 2^31 ; presented as degrees, minutes, seconds ; altitude is uint32 centimetres plus 10,000,000 ; presented as metres ; ; presentation order is ; latitude ; longitude ; altitude ; size (default 1m) ; horiz-pre (default 10000m) ; vert-pre (default 10m) TYPE30 NXT Next domain (OBSOLETE) [RFC2535] name NEXT Next domain name decompress bitlist rrtype TYPE31 EID Endpoint Identifier TYPE32 NIMLOC Nimrod Locator TYPE33 SRV Service location [RFC2782] uint16 PRIORITY Preference (lower values tried first) uint16 WEIGHT - uint16 PORT - name TARGET - host additional decompress TYPE34 ATMA ATM address TYPE35 NAPTR Naming authority pointer [RFC3403] uint16 ORDER Order (lower values processed first) uint16 PREFERENCE Preference (lower values tried first) text FLAGS - text SERVICES - text REGEXP Regular expression name REPLACEMENT - decompress TYPE36 KX Key exchanger [RFC2230] uint16 PREFERENCE Preference (lower values tried first) name EXCHANGER Host name host additional TYPE37 CERT Cryptographic certificate [RFC4398] uint16 TYPE - 1 PKIX X.509 as per PKIX 2 SPKI SPKI certificate 3 PGP OpenPGP packet 4 IPKIX The URL of an X.509 data object 5 ISPKI The URL of an SPKI certificate 6 IPGP The fingerprint and URL of an OpenPGP packet 7 ACPKIX Attribute Certificate 8 IACPKIX The URL of an Attribute Certificate 253 URI Type described by URI 254 OID Type described by OID uint16 KEY-TAG Key tag algo ALGORITHM Algorithm base64 - Certificate or CRL data TYPE38 A6 Partial IPv6 address (OBSOLETE - use AAAA) [RFC2874] a6 ADDRESS Prefix length and address suffix name PREFIX-NAME Prefix name optional TYPE39 DNAME Subdomain redirect [RFC2672] name DNAME Target domain TYPE40 SINK Kitchen sink uint16 CODING - uint16 SUBCODING - base64 DATA - TYPE41 OPT Extension pseudo-record [RFC2671] TYPE42 APL Address prefix list [RFC3123] ; Complicated syntax ; repeat ; uint16 ADDRESSFAMILY ; 1 - IPv4 ; 2 - IPv6 ; flags16 - - ; 65280 PREFIX - ; 128 N - ; 12 7 AFDLENGTH - ; ipv4/ipv6 AFDPART - TYPE43 DS Delegation signer [RFC4034] uint16 KEY-TAG Key tag algo ALGORITHM Algorithm uint8 DIGEST-TYPE Digest type 1 SHA-1 - 2 SHA-256 - 3 GOST - 4 SHA-384 - base64 DIGEST Key digest TYPE44 SSHFP Secure shell key fingerprint [RFC4255] uint8 ALGORITHM Algorithm 1 RSA - 2 DSS - uint8 FP-TYPE Fingerprint type 1 SHA-1 - hex FINGERPRINT Fingerprint TYPE45 IPSECKEY IPSEC public key [RFC4025] ; uint8 PRECEDENCE Preference (lower values tried first) ; uint8 GATEWAY-TYPE - ; 1 - IPv4 address ; 2 - IPv6 address ; 3 - Domain name ; uint8 ALGORITHM - ; 1 DSA - [RFC2536] ; 2 RSA - [RFC3110] ; ipv4/ipv6/name GATEWAY - ; base64 PUBLIC-KEY - TYPE46 RRSIG DNSSEC resource record signature [RFC4034] rrtype TYPE-COVERED Type covered algo ALGORITHM Signature algorithm uint8 LABELS Non-wildcard label count uint32 ORIG-TTL Original TTL interval time EXPIRATION Expiration time time INCEPTION Inception time uint16 KEY-TAG Key tag name SIGNER Key name base64 SIGNATURE Signature data TYPE47 NSEC DNSSEC next resource record [RFC4034] name NEXT Next domain name nsec TYPES Resource record types present TYPE48 DNSKEY DNSSEC public key [RFC4034] flags16 FLAGS Flags 256 - Zone key 128 - Revoked 1 - Secure entry point (KSK) uint8 PROTOCOL Protocol 3 - DNSSEC algo ALGORITHM Algorithm base64 PUBLIC-KEY Public key data TYPE49 DHCID DHCP client identifier [RFC4701] base64 - - TYPE50 NSEC3 DNSSEC hashed resource record existence [RFC5155] ; uint8 - Hash algorithm ; 1 - SHA-1 ; flags8 - Flags ; uint16 - Iterations ; uint8 - Salt length ; hex - Salt ; uint8 - Hash length ; base32 - Next hashed owner name ; nsec - Resource record types present TYPE51 NSEC3PARAM NSEC3 parameters [RFC5155] ; uint8 - Hash algorithm ; 1 - SHA-1 ; flags8 - Flags ; uint16 - Iterations ; uint8 - Salt length ; hex - Salt TYPE55 HIP Host Identity Protocol [RFC5205] ; uint8 HIT-LEN HIT length (missing in presentation format) ; uint8 PK-ALGO Public key algorithm ; uint16 PK-LEN Public key length (missing in presentation format) ; hex HIT - ; base64 PK Public key (no whitespace allowed) ; name - Rendezvous servers ; multiple TYPE99 SPF Mail sender policy framework [RFC4408] text TXT-DATA - multiple _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
