quic: implement keepAlive option and ping support

Signed-off-by: James M Snell <jasnell@gmail.com>

Author: jasnell

doc/api/quic.md

@@ -1403,6 +1403,20 @@ added: v23.8.0
 Specifies the maximum number of milliseconds a TLS handshake is permitted to take
 to complete before timing out.
 
+#### `sessionOptions.keepAlive`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+* Type: {bigint|number}
+* **Default:** `0` (disabled)
+
+Specifies the keep-alive timeout in milliseconds. When set to a non-zero
+value, PING frames will be sent automatically to keep the connection alive
+before the idle timeout fires. The value should be less than the effective
+idle timeout (`maxIdleTimeout` transport parameter) to be useful.
+
 #### `sessionOptions.servername` (client only)
 
 <!-- YAML

lib/internal/quic/quic.js

@@ -271,6 +271,8 @@ const onSessionHandshakeChannel = dc.channel('quic.session.handshake');
  * @property {boolean} [qlog] Enable qlog
  * @property {ArrayBufferView} [sessionTicket] The session ticket
  * @property {bigint|number} [handshakeTimeout] The handshake timeout
+ * @property {bigint|number} [keepAlive] The keep-alive timeout in milliseconds. When set,
+ *   PING frames will be sent automatically to prevent idle timeout.
  * @property {bigint|number} [maxStreamWindow] The maximum stream window
  * @property {bigint|number} [maxWindow] The maximum window
  * @property {bigint|number} [maxPayloadSize] The maximum payload size
@@ -2480,6 +2482,7 @@ function processSessionOptions(options, config = { __proto__: null }) {
     maxPayloadSize,
     unacknowledgedPacketThreshold = 0,
     handshakeTimeout,
+    keepAlive,
     maxStreamWindow,
     maxWindow,
     cc,
@@ -2514,6 +2517,7 @@ function processSessionOptions(options, config = { __proto__: null }) {
     maxPayloadSize,
     unacknowledgedPacketThreshold,
     handshakeTimeout,
+    keepAlive,
     maxStreamWindow,
     maxWindow,
     sessionTicket,

src/quic/bindingdata.h

@@ -77,6 +77,7 @@ class Packet;
   V(groups, "groups")                                                          \
   V(handshake_timeout, "handshakeTimeout")                                     \
   V(http3_alpn, &NGHTTP3_ALPN_H3[1])                                           \
+  V(keep_alive_timeout, "keepAlive")                                           \
   V(initial_max_data, "initialMaxData")                                        \
   V(initial_max_stream_data_bidi_local, "initialMaxStreamDataBidiLocal")       \
   V(initial_max_stream_data_bidi_remote, "initialMaxStreamDataBidiRemote")     \

src/quic/session.cc

@@ -209,7 +209,7 @@ void ngtcp2_debug_log(void* user_data, const char* fmt, ...) {
   va_end(ap);
 }
 
-template <typename Opt, PreferredAddress::Policy Opt::*member>
+template <typename Opt, PreferredAddress::Policy Opt::* member>
 bool SetOption(Environment* env,
                Opt* options,
                const Local<Object>& object,
@@ -224,7 +224,7 @@ bool SetOption(Environment* env,
   return true;
 }
 
-template <typename Opt, TLSContext::Options Opt::*member>
+template <typename Opt, TLSContext::Options Opt::* member>
 bool SetOption(Environment* env,
                Opt* options,
                const Local<Object>& object,
@@ -239,7 +239,7 @@ bool SetOption(Environment* env,
   return true;
 }
 
-template <typename Opt, TransportParams::Options Opt::*member>
+template <typename Opt, TransportParams::Options Opt::* member>
 bool SetOption(Environment* env,
                Opt* options,
                const Local<Object>& object,
@@ -254,7 +254,7 @@ bool SetOption(Environment* env,
   return true;
 }
 
-template <typename Opt, ngtcp2_cc_algo Opt::*member>
+template <typename Opt, ngtcp2_cc_algo Opt::* member>
 bool SetOption(Environment* env,
                Opt* options,
                const Local<Object>& object,
@@ -437,9 +437,9 @@ Maybe<Session::Options> Session::Options::From(Environment* env,
 
   if (!SET(version) || !SET(min_version) || !SET(preferred_address_strategy) ||
       !SET(transport_params) || !SET(tls_options) || !SET(qlog) ||
-      !SET(handshake_timeout) || !SET(max_stream_window) || !SET(max_window) ||
-      !SET(max_payload_size) || !SET(unacknowledged_packet_threshold) ||
-      !SET(cc_algorithm)) {
+      !SET(handshake_timeout) || !SET(keep_alive_timeout) ||
+      !SET(max_stream_window) || !SET(max_window) || !SET(max_payload_size) ||
+      !SET(unacknowledged_packet_threshold) || !SET(cc_algorithm)) {
     return Nothing<Options>();
   }
 
@@ -1321,6 +1321,11 @@ Session::Session(Endpoint* endpoint,
     if (app) SetApplication(std::move(app));
   }
 
+  if (config.options.keep_alive_timeout > 0) {
+    ngtcp2_conn_set_keep_alive_timeout(
+        *this, config.options.keep_alive_timeout * NGTCP2_MILLISECONDS);
+  }
+
   MakeWeak();
   Debug(this, "Session created.");
   auto& binding = BindingData::Get(env());

src/quic/session.h

@@ -151,6 +151,11 @@ class Session final : public AsyncWrap, private SessionTicket::AppData::Source {
     // completion of the tls handshake.
     uint64_t handshake_timeout = UINT64_MAX;
 
+    // The keep-alive timeout in milliseconds. When set to a non-zero value,
+    // ngtcp2 will automatically send PING frames to keep the connection alive
+    // before the idle timeout fires. Set to 0 to disable (default).
+    uint64_t keep_alive_timeout = 0;
+
     // Maximum initial flow control window size for a stream.
     uint64_t max_stream_window = 0;