Merge branch 'fix-for-dns-candidate-queries' into 'master'

fix: native resolver only tries candidate names when server indicates

See merge request os85/httpx!236

lib/httpx/resolver.rb

@@ -108,7 +108,15 @@ module HTTPX
 
     def decode_dns_answer(payload)
       message = Resolv::DNS::Message.decode(payload)
+
+      # no domain was found
+      return if message.rcode == Resolv::DNS::RCode::NXDomain
+
       addresses = []
+
+      # TODO: raise an "other dns OtherResolvError" type of error
+      return addresses if message.rcode != Resolv::DNS::RCode::NoError
+
       message.each_answer do |question, _, value|
         case value
         when Resolv::DNS::Resource::IN::CNAME

lib/httpx/resolver/https.rb

@@ -136,9 +136,22 @@ module HTTPX
         emit_resolve_error(connection, connection.origin.host, e)
         return
       end
-      if answers.nil? || answers.empty?
+
+      if answers.nil?
+        # Indicates no such domain was found.
+
         host = @requests.delete(request)
         connection = @queries.delete(host)
+
+        emit_resolve_error(connection) unless @queries.value?(connection)
+      elsif answers.empty?
+        # no address found, eliminate candidates
+        host = @requests.delete(request)
+        connection = @queries.delete(host)
+
+        # eliminate other candidates
+        @queries.delete_if { |_, conn| connection == conn }
+
         emit_resolve_error(connection)
         return
 

lib/httpx/resolver/native.rb

@@ -215,7 +215,8 @@ module HTTPX
         raise ex
       end
 
-      if addresses.nil? || addresses.empty?
+      if addresses.nil?
+        # Indicates no such domain was found.
         hostname, connection = @queries.first
         @queries.delete(hostname)
         @timeouts.delete(hostname)
@@ -224,6 +225,14 @@ module HTTPX
           @connections.delete(connection)
           raise NativeResolveError.new(connection, connection.origin.host)
         end
+      elsif addresses.empty?
+        # no address found, eliminate candidates
+        _, connection = @queries.first
+        candidates = @queries.select { |_, conn| connection == conn }.keys
+        @queries.delete_if { |hs, _| candidates.include?(hs) }
+        @timeouts.delete_if { |hs, _| candidates.include?(hs) }
+        @connections.delete(connection)
+        raise NativeResolveError.new(connection, connection.origin.host)
       else
         address = addresses.first
         name = address["name"]

sig/resolver.rbs

@@ -30,6 +30,6 @@ module HTTPX
 
     def self?.encode_dns_query: (String hostname, ?type: dns_resource) -> String
 
-    def self?.decode_dns_answer: (String) -> Array[dns_result]
+    def self?.decode_dns_answer: (String) -> Array[dns_result]?
   end
 end

sig/resolver/https.rbs

@@ -34,7 +34,7 @@ module HTTPX
 
       def build_request: (String hostname) -> Request
 
-      def decode_response_body: (Response) -> Array[dns_result]
+      def decode_response_body: (Response) -> Array[dns_result]?
     end
   end
 end