Add support for SVCB and HTTPS resource records (RFC 9460)

README.md

@@ -20,8 +20,8 @@ The following is a (non-exhaustive) list of features :
 
 - Implemented RRs :  A, AAAA, AFSDB, ANY, CAA, CERT, CNAME, DNAME,
      GPOS, HINFO, ISDN, LOC, MB, MG, MINFO, MR, MX, NAPTR, NS, NSAP,
-     NXT, OPT, PTR, PX, RP, RT, SOA, SPF, SRV, TKEY, TSIG, TXT,
-     WKS, X25, DNSKEY, RRSIG, NSEC, NSEC3, NSEC3PARAM, DS, DLV
+     NXT, OPT, PTR, PX, RP, RT, SOA, SPF, SRV, SVCB, HTTPS, TKEY,
+     TSIG, TXT, WKS, X25, DNSKEY, RRSIG, NSEC, NSEC3, NSEC3PARAM, DS, DLV
 
 - Generic RR types supported (RFC3597)
 

RELEASE_NOTES.md

@@ -1,5 +1,14 @@
 # Release Notes
 
+## Unreleased
+
+* Add support for SVCB (type 64) and HTTPS (type 65) resource records - RFC 9460, including zone file parsing with TargetName origin resolution
+  * Recognises the registered SvcParamKey mnemonics `mandatory`, `alpn`, `no-default-alpn`, `port`, `ipv4hint`, `ipv6hint` (RFC 9460), `ech` (RFC 9848), `dohpath` (RFC 9461), `ohttp` (RFC 9540) and `docpath` (RFC 9953). Any other key reads and writes as `keyNNNNN`
+* **Breaking (text output only)** - `Dnsruby::IPv6#to_s` and `#inspect` now emit the RFC 5952 canonical form: lowercase hex, no leading zeros, and `::` for the longest run of all-zero fields (never a single field)
+  * Affects `AAAA`, `IPSECKEY` and `APL` records and log output; code that string-compares the old uppercase form needs updating. Parsing and wire format are unchanged
+  * `::ffff:0:0/96` now uses the mixed notation (`::ffff:192.0.2.1`); the deprecated IPv4-compatible `::/96` range keeps the hexadecimal form, unlike `IPAddr#to_s` and `inet_ntop`
+* Fix `Dnsruby::ZoneReader` splitting an unquoted character-string in two at a backslash-escaped quote - RFC 1035 Section 5.1 makes `\"` a literal quote, so `TXT \"escaped` is one string and was previously read as `"", "\"escaped"`
+
 ## v1.74.0
 
 * Resolve all configured nameservers in parallel

lib/dnsruby/code_mappers.rb

@@ -165,6 +165,8 @@ class Types < CodeMapper
     HIP       = 55      # RFC 5205
     CDS       = 59      # RFC 7344
     CDNSKEY   = 60      # RFC 7344
+    SVCB      = 64      # RFC 9460
+    HTTPS     = 65      # RFC 9460
     SPF       = 99      # RFC 4408
     UINFO     = 100     # non-standard
     UID       = 101     # non-standard

lib/dnsruby/ipv6.rb

@@ -108,12 +108,40 @@ def initialize(address) #:nodoc:
     #  The raw IPv6 address as a String
     attr_reader :address
 
+    #  The RFC 5952 canonical text representation of the address
     def to_s
-      address = sprintf("%X:%X:%X:%X:%X:%X:%X:%X", *@address.unpack("nnnnnnnn"))
-      unless address.sub!(/(^|:)0(:0)+(:|$)/, '::')
-        address.sub!(/(^|:)0(:|$)/, '::')
+      fields = @address.unpack("n8")
+
+      #  RFC 5952 section 5: an address carrying an embedded IPv4 address
+      #  under the well-known ::ffff:0:0/96 prefix is written in the mixed
+      #  hexadecimal / dotted decimal notation.
+      if fields[0, 5].all?(&:zero?) && fields[5] == 0xffff
+        return "::ffff:" + fields[6, 2].pack("n2").unpack("C4").join(".")
+      end
+
+      #  RFC 5952 section 4.2.3: "::" replaces the longest run of consecutive
+      #  all-zero fields, and the first such run when several are equally long.
+      #  Section 4.2.2: a run of a single all-zero field is never replaced.
+      run_start = nil
+      best_start, best_length = nil, 1
+      fields.each_with_index do |field, i|
+        if field == 0
+          run_start ||= i
+          length = i - run_start + 1
+          best_start, best_length = run_start, length if length > best_length
+        else
+          run_start = nil
+        end
+      end
+
+      #  RFC 5952 sections 4.1 and 4.3: no leading zeros, and lowercase hex
+      strings = fields.map {|field| field.to_s(16)}
+      if best_start
+        strings[best_start, best_length] = ['']
+        strings.unshift('') if best_start == 0
+        strings.push('') if best_start + best_length == fields.length
       end
-      return address
+      return strings.join(':')
     end
 
     def inspect #:nodoc:
@@ -141,4 +169,4 @@ def hash
       return @address.hash
     end
   end
-end
+end

lib/dnsruby/resource/HTTPS.rb

@@ -0,0 +1,16 @@
+require 'dnsruby/resource/SVCB'
+
+module Dnsruby
+  class RR
+    # Class for DNS HTTPS resource records.
+    #
+    # RFC 9460 sec 9
+    #
+    # The HTTPS-specific instantiation of the SVCB record, sharing its wire and
+    # presentation formats, for the "https" and "http" URI schemes.
+    class HTTPS < SVCB
+      ClassValue = nil #:nodoc: all
+      TypeValue = Types::HTTPS #:nodoc: all
+    end
+  end
+end

lib/dnsruby/resource/IN.rb

@@ -59,6 +59,8 @@ class RR
       Types::GPOS => GPOS,
       Types::NXT => NXT,
       Types::CAA => CAA,
+      Types::SVCB => SVCB,
+      Types::HTTPS => HTTPS,
     } #:nodoc: all
 
     #  module IN contains ARPA Internet specific RRs