PowerDNS JSON handler

src/pdns-dhcp/PowerDns/Methods.cs

@@ -1,4 +1,3 @@
-using System.Text.Json;
 using System.Text.Json.Serialization;
 
 namespace pdns_dhcp.PowerDns;
@@ -8,19 +7,21 @@ public interface IMethod;
 [JsonPolymorphic(TypeDiscriminatorPropertyName = "method")]
 [JsonDerivedType(typeof(InitializeMethod), "initialize")]
 [JsonDerivedType(typeof(LookupMethod), "lookup")]
-public abstract class Method
+public class Method;
-{
-	[JsonExtensionData]
-	public Dictionary<string, JsonElement> ExtensionData { get; } = [];
-}
 
-public abstract class Method<TSelf> : Method where TSelf : Method<TSelf>, IMethod;
+[JsonSerializable(typeof(Method)), JsonSourceGenerationOptions(
+	GenerationMode = JsonSourceGenerationMode.Metadata,
+	NumberHandling = JsonNumberHandling.AllowReadingFromString,
+	UseStringEnumConverter = true
+)]
+internal partial class MethodContext : JsonSerializerContext;
 
-public abstract class Method<TSelf, TParam>(TParam parameters) : Method<TSelf> where TSelf : Method<TSelf, TParam>, IMethod
+public abstract class Method<TParam>(TParam parameters) : Method
+	where TParam : MethodParameters
 {
 	public TParam Parameters => parameters;
 }
 
-public class InitializeMethod : Method<InitializeMethod>, IMethod;
+public class InitializeMethod(InitializeMethodParameters parameters) : Method<InitializeMethodParameters>(parameters), IMethod;
 
-public class LookupMethod : Method<LookupMethod>, IMethod;
+public class LookupMethod(LookupMethodParameters parameters) : Method<LookupMethodParameters>(parameters), IMethod;

src/pdns-dhcp/PowerDns/Parameters.cs

@@ -0,0 +1,26 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace pdns_dhcp.PowerDns;
+
+public record class Parameters;
+
+public record class MethodParameters : Parameters
+{
+	[JsonExtensionData]
+	public Dictionary<string, JsonElement> AdditionalProperties { get; set; } = [];
+}
+
+public record class InitializeMethodParameters(
+	[property: JsonPropertyName("command")] string Command,
+	[property: JsonPropertyName("timeout")] int Timeout
+) : MethodParameters;
+
+public record class LookupMethodParameters(
+	[property: JsonPropertyName("qtype")] string Qtype,
+	[property: JsonPropertyName("qname")] string Qname,
+	[property: JsonPropertyName("remote")] string Remote,
+	[property: JsonPropertyName("local")] string Local,
+	[property: JsonPropertyName("real-remote")] string RealRemote,
+	[property: JsonPropertyName("zone-id")] int ZoneId
+) : MethodParameters;

src/pdns-dhcp/PowerDns/PowerDnsHandler.cs

@@ -15,6 +15,7 @@ public class PowerDnsHandler : ConnectionHandler
 		JsonReaderState state = default;
 		using ArrayPoolBufferWriter<byte> json = new();
 		using ArrayPoolBufferWriter<byte> buffer = new();
+		using var writer = connection.Transport.Output.AsStream();
 		while (!connection.ConnectionClosed.IsCancellationRequested)
 		{
 			var read = await input.ReadAsync(connection.ConnectionClosed).ConfigureAwait(false);
@@ -28,9 +29,19 @@ public class PowerDnsHandler : ConnectionHandler
 				buffer.Write(memory.Span);
 				if (ConsumeJson(buffer, json, ref state))
 				{
-					var method = JsonSerializer.Deserialize<Method>(json.WrittenSpan);
+					var method = JsonSerializer.Deserialize(json.WrittenSpan, MethodContext.Default.Method)!;
 					json.Clear();
 					state = default;
+
+					Reply reply = BoolReply.False;
+					try
+					{
+						reply = await Handle(method, connection.ConnectionClosed).ConfigureAwait(false);
+					}
+					catch (Exception e) { }
+
+					await JsonSerializer.SerializeAsync(writer, reply, ReplyContext.Default.Reply, connection.ConnectionClosed)
+						.ConfigureAwait(ConfigureAwaitOptions.SuppressThrowing);
 				}
 			}
 
@@ -75,4 +86,25 @@ public class PowerDnsHandler : ConnectionHandler
 			return final;
 		}
 	}
+
+	private ValueTask<Reply> Handle(Method method, CancellationToken cancellationToken = default)
+	{
+		return method switch
+		{
+			InitializeMethod init => HandleInitializeMethod(init),
+			LookupMethod lookup => HandleLookupMethod(lookup),
+
+			_ => ValueTask.FromResult<Reply>(new BoolReply(false))
+		};
+	}
+
+	private ValueTask<Reply> HandleInitializeMethod(InitializeMethod method)
+	{
+		return ValueTask.FromResult(BoolReply.True);
+	}
+
+	private ValueTask<Reply> HandleLookupMethod(LookupMethod method)
+	{
+		return ValueTask.FromResult(BoolReply.False);
+	}
 }

src/pdns-dhcp/PowerDns/Replies.cs

@@ -1,10 +1,46 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
 namespace pdns_dhcp.PowerDns;
 
+[JsonDerivedType(typeof(BoolReply))]
+[JsonDerivedType(typeof(LookupReply))]
 public abstract class Reply;
 
+[JsonSerializable(typeof(Reply)), JsonSourceGenerationOptions(
+	GenerationMode = JsonSourceGenerationMode.Serialization,
+	PropertyNamingPolicy = JsonKnownNamingPolicy.KebabCaseLower,
+	WriteIndented = false
+)]
+internal partial class ReplyContext : JsonSerializerContext;
+
 public abstract class Reply<T>(T result) : Reply
 {
 	public T Result => result;
 }
 
-public class BoolReply(bool result) : Reply<bool>(result);
+public class BoolReply(bool result) : Reply<bool>(result)
+{
+	public static Reply False { get; } = new BoolReply(false);
+
+	public static Reply True { get; } = new BoolReply(true);
+}
+
+public class LookupReply(QueryResult[] result) : Reply<QueryResult[]>(result);
+
+public record QueryResult(
+	[property: JsonPropertyName("qtype")] string QType,
+	[property: JsonPropertyName("qname")] string QName,
+	[property: JsonPropertyName("content")] string Content,
+	[property: JsonPropertyName("ttl")] int TTL
+)
+{
+	[JsonPropertyName("auth")]
+	public bool? Auth { get; init; } = default;
+
+	[JsonPropertyName("domain_id")]
+	public int? DomainId { get; init; } = default;
+
+	[JsonPropertyName("scopeMask")]
+	public int? ScopeMask { get; init; } = default;
+}