feat(quic): replace probe UDP data plane with QUIC datagrams

backend/shared/MoShiro.Protocol/Catalog/Kinds/Kinds.cs

@@ -27,10 +27,10 @@ public static class Kinds
 
     public static readonly KindSpec UdpEcho = new(
         "udp_echo",
-        "UDP echo",
-        "Fixed-rate UDP echo with four timestamps per packet.",
+        "QUIC Datagram echo",
+        "Fixed-rate QUIC Datagram echo with four timestamps per packet.",
         Scope.Line,
-        new BlockSet("udp", "fixed", "fixed", "echo", []),
+        new BlockSet("quic_datagram", "fixed", "fixed", "echo", []),
         [
             P.Int("rate_hz", 10, 1, 200, "Hz"),
             P.Int("size", 64, 44, 1400, "B"),
@@ -41,10 +41,10 @@ public static class Kinds
 
     public static readonly KindSpec UdpTrain = new(
         "udp_train",
-        "UDP train",
-        "Fixed-rate or laddered one-way UDP stream (Agent to Probe) for loss and jitter under load.",
+        "QUIC Datagram train",
+        "Fixed-rate or laddered one-way QUIC Datagram stream (Agent to Probe) for loss and delay variation under load.",
         Scope.Line,
-        new BlockSet("udp", "ladder", "fixed", "sink", []),
+        new BlockSet("quic_datagram", "ladder", "fixed", "sink", []),
         [
             P.Number("mbps", 10, 0.1, 1000, "Mbit/s"),
             P.Int("size", 1250, 200, 1400, "B"),

backend/shared/MoShiro.Protocol/Rpc/MoShiroRpc.cs

@@ -146,8 +146,11 @@ public sealed class AgentEndpoint
     [JsonPropertyName("tcp_port")]
     public int TcpPort { get; set; }
 
+    [JsonPropertyName("quic_ports")]
+    public List<int> QuicPorts { get; set; } = [];
+
     [JsonPropertyName("udp_ports")]
-    public List<int> UdpPorts { get; set; } = [];
+    public List<int> LegacyUdpPorts { get; set; } = [];
 
     /// <summary>Agent 面向 Probe 的 TLS 证书公钥（SPKI，base64）：证书按它的 SHA-256 指纹固定，敲门密钥由它和 Probe 的身份密钥派生。</summary>
     [JsonPropertyName("public_key")]
@@ -175,8 +178,11 @@ public sealed class AgentEnrollMeta
     [JsonPropertyName("probe_tcp_port")]
     public int ProbeTcpPort { get; set; } = 7443;
 
+    [JsonPropertyName("probe_quic_ports")]
+    public List<int> ProbeQuicPorts { get; set; } = [];
+
     [JsonPropertyName("probe_udp_ports")]
-    public List<int> ProbeUdpPorts { get; set; } = [7443];
+    public List<int>? LegacyProbeUdpPorts { get; set; }
 
     [JsonPropertyName("public_host")]
     public string? PublicHost { get; set; }
@@ -296,6 +302,9 @@ public sealed class UpdateStatus
 /// <summary>Probe 的 <c>fleet.heartbeat</c> 附加字段：更新器的状态。</summary>
 public sealed class ProbeHeartbeatExtra
 {
+    [JsonPropertyName("quic_links")]
+    public List<ProbeQuicLinkHealth>? QuicLinks { get; set; }
+
     [JsonPropertyName("ipv6")]
     public Ipv6Diagnostic? Ipv6 { get; set; }
 
@@ -303,6 +312,53 @@ public sealed class ProbeHeartbeatExtra
     public UpdateStatus? Update { get; set; }
 }
 
+/// <summary>Probe's rolling QUIC connection health snapshot for one Agent/IP path.</summary>
+public sealed class ProbeQuicLinkHealth
+{
+    [JsonPropertyName("agent_id")]
+    public string AgentId { get; set; } = "";
+
+    [JsonPropertyName("ip_version")]
+    public string IpVersion { get; set; } = IpVersions.V4;
+
+    [JsonPropertyName("connected")]
+    public bool Connected { get; set; }
+
+    [JsonPropertyName("handshake_attempts")]
+    public long HandshakeAttempts { get; set; }
+
+    [JsonPropertyName("handshake_successes")]
+    public long HandshakeSuccesses { get; set; }
+
+    [JsonPropertyName("handshake_failures")]
+    public long HandshakeFailures { get; set; }
+
+    [JsonPropertyName("handshake_timeouts")]
+    public long HandshakeTimeouts { get; set; }
+
+    [JsonPropertyName("handshake_p95_ms")]
+    public double? HandshakeP95Ms { get; set; }
+
+    [JsonPropertyName("handshake_sample_count")]
+    public long HandshakeSampleCount { get; set; }
+
+    /// <summary>QUIC packet-loss estimate from MsQuic's non-spurious loss counters; not Datagram application loss or retransmission.</summary>
+    [JsonPropertyName("transport_packet_loss_rate")]
+    public double? TransportPacketLossRate { get; set; }
+
+    [JsonPropertyName("transport_packets_sent")]
+    public ulong? TransportPacketsSent { get; set; }
+
+    [JsonPropertyName("transport_congestion_events")]
+    public uint? TransportCongestionEvents { get; set; }
+
+    [JsonPropertyName("transport_ecn_congestion_events")]
+    public uint? TransportEcnCongestionEvents { get; set; }
+
+    [JsonPropertyName("path_mtu")]
+    public ushort? PathMtu { get; set; }
+}
+
 /// <summary>Probe 的 <c>fleet.hello</c> 附加字段：系统、架构和构建信息（只用于展示和更新）。</summary>
 public sealed class ProbeHelloMeta
 {
@@ -345,8 +401,11 @@ public sealed class AgentHelloMeta
     [JsonPropertyName("probe_tcp_port")]
     public int? ProbeTcpPort { get; set; }
 
+    [JsonPropertyName("probe_quic_ports")]
+    public List<int>? ProbeQuicPorts { get; set; }
+
     [JsonPropertyName("probe_udp_ports")]
-    public List<int>? ProbeUdpPorts { get; set; }
+    public List<int>? LegacyProbeUdpPorts { get; set; }
 
     [JsonPropertyName("local_limits")]
     public LocalLimits? LocalLimits { get; set; }
@@ -482,8 +541,11 @@ public sealed class LineTaskSet
     public List<LineTask> Tasks { get; set; } = [];
 
     /// <summary>Agent 的数据面端口（Probe 把包发到这里）。</summary>
+    [JsonPropertyName("quic_ports")]
+    public List<int> QuicPorts { get; set; } = [];
+
     [JsonPropertyName("udp_ports")]
-    public List<int> UdpPorts { get; set; } = [];
+    public List<int> LegacyUdpPorts { get; set; } = [];
 
     [JsonPropertyName("tcp_ports")]
     public List<int> TcpPorts { get; set; } = [];

backend/shared/MoShiro.Protocol/Wire/MeasurementDatagram.cs

@@ -3,7 +3,7 @@ using System.Security.Cryptography;
 
 namespace MoShiro.Protocol;
 
-public enum UdpPacketType : byte
+public enum MeasurementDatagramType : byte
 {
     EchoRequest = 1,
     EchoReply = 2,
@@ -12,7 +12,7 @@ public enum UdpPacketType : byte
     Data = 3,
 }
 
-public readonly record struct UdpHeader(UdpPacketType Type, long SessionId, uint StreamId, uint Seq, long SendTsUs);
+public readonly record struct MeasurementDatagramHeader(MeasurementDatagramType Type, long SessionId, uint StreamId, uint Seq, long SendTsUs);
 
 /// <summary>
 /// 数据面的 UDP 包（Fleet 之外的线格式）：
@@ -20,7 +20,7 @@ public readonly record struct UdpHeader(UdpPacketType Type, long SessionId, uint
 /// mac = HMAC-SHA256(session_key, 前面全部字节) 截断到 16 字节。所有整数小端。
 /// 接收方对不合法的包静默丢弃并计数，不回复（防放大）。
 /// </summary>
-public static class UdpPacket
+public static class MeasurementDatagram
 {
     public const ushort Magic = 0x4D4E; // "MN"
     public const byte Version = 1;
@@ -30,19 +30,19 @@ public static class UdpPacket
     public const int MaxBytes = 1472;
 
     /// <summary>检查长度、magic、version、type 并解析头部（不校验 MAC）。</summary>
-    public static bool TryParseHeader(ReadOnlySpan<byte> packet, out UdpHeader header)
+    public static bool TryParseHeader(ReadOnlySpan<byte> packet, out MeasurementDatagramHeader header)
     {
         header = default;
         if (packet.Length is < MinBytes or > MaxBytes
             || BinaryPrimitives.ReadUInt16LittleEndian(packet) != Magic
             || packet[2] != Version
-            || packet[3] is < (byte)UdpPacketType.EchoRequest or > (byte)UdpPacketType.Data)
+            || packet[3] is < (byte)MeasurementDatagramType.EchoRequest or > (byte)MeasurementDatagramType.Data)
         {
             return false;
         }
 
-        header = new UdpHeader(
-            (UdpPacketType)packet[3],
+        header = new MeasurementDatagramHeader(
+            (MeasurementDatagramType)packet[3],
             BinaryPrimitives.ReadInt64LittleEndian(packet[4..]),
             BinaryPrimitives.ReadUInt32LittleEndian(packet[12..]),
             BinaryPrimitives.ReadUInt32LittleEndian(packet[16..]),
@@ -51,7 +51,7 @@ public static class UdpPacket
     }
 
     /// <summary>写入整个包（长度就是 <paramref name="destination"/> 的长度），填充为零，末尾是 MAC。</summary>
-    public static void Write(Span<byte> destination, in UdpHeader header, ReadOnlySpan<byte> key)
+    public static void Write(Span<byte> destination, in MeasurementDatagramHeader header, ReadOnlySpan<byte> key)
     {
         if (destination.Length is < MinBytes or > MaxBytes)
         {

backend/shared/MoShiro.Protocol/Wire/TcpWire.cs

@@ -19,8 +19,8 @@ public static class TcpWire
 
     public static void WriteAuth(Span<byte> destination, long sessionId, uint streamId, ReadOnlySpan<byte> nonce, ReadOnlySpan<byte> key)
     {
-        BinaryPrimitives.WriteUInt16LittleEndian(destination, UdpPacket.Magic);
-        destination[2] = UdpPacket.Version;
+        BinaryPrimitives.WriteUInt16LittleEndian(destination, MeasurementDatagram.Magic);
+        destination[2] = MeasurementDatagram.Version;
         BinaryPrimitives.WriteInt64LittleEndian(destination[3..], sessionId);
         BinaryPrimitives.WriteUInt32LittleEndian(destination[11..], streamId);
         nonce[..NonceBytes].CopyTo(destination[15..]);
@@ -35,7 +35,7 @@ public static class TcpWire
         sessionId = 0;
         streamId = 0;
         nonce = default;
-        if (frame.Length != AuthBytes || BinaryPrimitives.ReadUInt16LittleEndian(frame) != UdpPacket.Magic || frame[2] != UdpPacket.Version)
+        if (frame.Length != AuthBytes || BinaryPrimitives.ReadUInt16LittleEndian(frame) != MeasurementDatagram.Magic || frame[2] != MeasurementDatagram.Version)
         {
             return false;
         }