* lib/resolv.rb (Resolv::DNS::Resource::IN::SRV): Added RFC2782 SRV

  resource record for specifying location of services.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@7848 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 58 insertions, 0 deletions

diff --git a/lib/resolv.rb b/lib/resolv.rb
index 769ebe34f5..fb92c638fb 100644
--- a/lib/resolv.rb
+++ b/lib/resolv.rb
@@ -1600,6 +1600,64 @@ class Resolv
             return self.new(IPv6.new(msg.get_bytes(16)))
           end
         end
+
+        # SRV resource record defined in RFC 2782
+        # 
+        # These records identify the hostname and port that a service is
+        # available at.
+        # 
+        # The format is:
+        #   _Service._Proto.Name TTL Class SRV Priority Weight Port Target
+        #
+        # The fields specific to SRV are defined in RFC 2782 as meaning:
+        # - +priority+ The priority of this target host.  A client MUST attempt
+        #   to contact the target host with the lowest-numbered priority it can
+        #   reach; target hosts with the same priority SHOULD be tried in an
+        #   order defined by the weight field.  The range is 0-65535.  Note that
+        #   it is not widely implemented and should be set to zero.
+        # 
+        # - +weight+ A server selection mechanism.  The weight field specifies
+        #   a relative weight for entries with the same priority. Larger weights
+        #   SHOULD be given a proportionately higher probability of being
+        #   selected. The range of this number is 0-65535.  Domain administrators
+        #   SHOULD use Weight 0 when there isn't any server selection to do, to
+        #   make the RR easier to read for humans (less noisy). Note that it is
+        #   not widely implemented and should be set to zero.
+        #
+        # - +port+  The port on this target host of this service.  The range is 0-
+        #   65535.
+        # 
+        # - +target+ The domain name of the target host. A target of "." means
+        #   that the service is decidedly not available at this domain.
+        class SRV < Resource
+          ClassHash[[TypeValue = 33, ClassValue = ClassValue]] = self
+
+          # Create a SRV resource record.
+          def initialize(priority, weight, port, target)
+            @priority = priority.to_int
+            @weight = weight.to_int
+            @port = port.to_int
+            @target = Name.create(target)
+          end
+
+          attr_reader :priority, :weight, :port, :target
+
+          def encode_rdata(msg)
+            msg.put_pack("n", @priority)
+            msg.put_pack("n", @weight)
+            msg.put_pack("n", @port)
+            msg.put_name(@target)
+          end
+
+          def self.decode_rdata(msg)
+            priority, = msg.get_unpack("n")
+            weight,   = msg.get_unpack("n")
+            port,     = msg.get_unpack("n")
+            target    = msg.get_name
+            return self.new(priority, weight, port, target)
+          end
+        end
+
       end
     end
   end