quic: support multiple ALPN negotiation

Signed-off-by: James M Snell <jasnell@gmail.com>
Assisted-by: Opencode:Opus 4.6
PR-URL: #62620
Reviewed-By: Robert Nagy <ronagy@icloud.com>
Reviewed-By: Tim Perry <pimterry@gmail.com>

Author: jasnell

doc/api/quic.md

@@ -1141,12 +1141,26 @@ added: v23.8.0
 #### `sessionOptions.alpn`
 
 <!-- YAML
-added: v23.8.0
+added: REPLACEME
 -->
 
-* Type: {string}
+* Type: {string} (client) | {string\[]} (server)
+
+The ALPN (Application-Layer Protocol Negotiation) identifier(s).
+
+For **client** sessions, this is a single string specifying the protocol
+the client wants to use (e.g. `'h3'`).
+
+For **server** sessions, this is an array of protocol names in preference
+order that the server supports (e.g. `['h3', 'h3-29']`). During the TLS
+handshake, the server selects the first protocol from its list that the
+client also supports.
+
+The negotiated ALPN determines which Application implementation is used
+for the session. `'h3'` and `'h3-*'` variants select the HTTP/3
+application; all other values select the default application.
 
-The ALPN protocol identifier.
+Default: `'h3'`
 
 #### `sessionOptions.ca` (client only)
 

lib/internal/quic/quic.js

@@ -33,7 +33,6 @@ let debug = require('internal/util/debuglog').debuglog('quic', (fn) => {
 
 const{
 Endpoint: Endpoint_,
-Http3Application: Http3,
  setCallbacks,
 
 // The constants to be exposed to end users for various options.
@@ -118,7 +117,6 @@ const {
 constkEmptyObject={__proto__: null};
 
 const{
- kApplicationProvider,
  kBlocked,
  kConnect,
  kDatagram,
@@ -2222,7 +2220,7 @@ function processIdentityOptions(identity, label) {
 functionprocessTlsOptions(tls,forServer){
 const{
  servername,
-protocol,
+alpn,
  ciphers =DEFAULT_CIPHERS,
  groups =DEFAULT_GROUPS,
  keylog =false,
@@ -2240,9 +2238,6 @@ function processTlsOptions(tls, forServer) {
 if(servername!==undefined){
 validateString(servername,'options.servername');
 }
-if(protocol!==undefined){
-validateString(protocol,'options.protocol');
-}
 if(ciphers!==undefined){
 validateString(ciphers,'options.ciphers');
 }
@@ -2253,11 +2248,42 @@ function processTlsOptions(tls, forServer) {
 validateBoolean(verifyClient,'options.verifyClient');
 validateBoolean(tlsTrace,'options.tlsTrace');
 
+// Encode the ALPN option to wire format (length-prefixed protocol names).
+// Server: array of protocol names. Client: single protocol name.
+// If not specified, the C++ default (h3) is used.
+letencodedAlpn;
+if(alpn!==undefined){
+constprotocols=forServer ?
+(ArrayIsArray(alpn) ? alpn : [alpn]) :
+[alpn];
+if(!forServer){
+validateString(alpn,'options.alpn');
+}
+lettotalLen=0;
+for(leti=0;i<protocols.length;i++){
+validateString(protocols[i],`options.alpn[${i}]`);
+if(protocols[i].length===0||protocols[i].length>255){
+thrownewERR_INVALID_ARG_VALUE(`options.alpn[${i}]`,protocols[i],
+'must be between 1 and 255 characters');
+}
+totalLen+=1+protocols[i].length;
+}
+// Build wire format: [len1][name1][len2][name2]...
+constbuf=Buffer.allocUnsafe(totalLen);
+letoffset=0;
+for(leti=0;i<protocols.length;i++){
+buf[offset++]=protocols[i].length;
+buf.write(protocols[i],offset,'ascii');
+offset+=protocols[i].length;
+}
+encodedAlpn=buf.toString('latin1');
+}
+
 // Shared TLS options (same for all identities on the endpoint).
 constshared={
 __proto__: null,
  servername,
-protocol,
+alpn: encodedAlpn,
  ciphers,
  groups,
  keylog,
@@ -2360,17 +2386,12 @@ function processSessionOptions(options, config = {}) {
  maxStreamWindow,
  maxWindow,
  cc,
-[kApplicationProvider]: provider,
 }=options;
 
 const{
  forServer =false,
 }=config;
 
-if(provider!==undefined){
-validateObject(provider,'options[kApplicationProvider]');
-}
-
 if(cc!==undefined){
 validateOneOf(cc,'options.cc',[CC_ALGO_RENO,CC_ALGO_BBR,CC_ALGO_CUBIC]);
 }
@@ -2392,7 +2413,6 @@ function processSessionOptions(options, config = {}) {
  maxStreamWindow,
  maxWindow,
  sessionTicket,
- provider,
  cc,
 };
 }
@@ -2494,7 +2514,6 @@ module.exports = {
  QuicEndpoint,
  QuicSession,
  QuicStream,
- Http3,
 CC_ALGO_RENO,
 CC_ALGO_CUBIC,
 CC_ALGO_BBR,

lib/internal/quic/state.js

@@ -62,6 +62,7 @@ const {
 IDX_STATE_SESSION_STREAM_OPEN_ALLOWED,
 IDX_STATE_SESSION_PRIORITY_SUPPORTED,
 IDX_STATE_SESSION_WRAPPED,
+IDX_STATE_SESSION_APPLICATION_TYPE,
 IDX_STATE_SESSION_LAST_DATAGRAM_ID,
 
 IDX_STATE_ENDPOINT_BOUND,
@@ -99,6 +100,7 @@ assert(IDX_STATE_SESSION_HANDSHAKE_CONFIRMED !== undefined);
 assert(IDX_STATE_SESSION_STREAM_OPEN_ALLOWED!==undefined);
 assert(IDX_STATE_SESSION_PRIORITY_SUPPORTED!==undefined);
 assert(IDX_STATE_SESSION_WRAPPED!==undefined);
+assert(IDX_STATE_SESSION_APPLICATION_TYPE!==undefined);
 assert(IDX_STATE_SESSION_LAST_DATAGRAM_ID!==undefined);
 assert(IDX_STATE_ENDPOINT_BOUND!==undefined);
 assert(IDX_STATE_ENDPOINT_RECEIVING!==undefined);
@@ -347,6 +349,12 @@ class QuicSessionState {
 return!!DataViewPrototypeGetUint8(this.#handle,IDX_STATE_SESSION_WRAPPED);
 }
 
+/** @type {number} */
+getapplicationType(){
+if(this.#handle.byteLength===0)returnundefined;
+returnDataViewPrototypeGetUint8(this.#handle,IDX_STATE_SESSION_APPLICATION_TYPE);
+}
+
 /** @type {bigint} */
 getlastDatagramId(){
 if(this.#handle.byteLength===0)returnundefined;
@@ -407,6 +415,7 @@ class QuicSessionState {
 isStreamOpenAllowed: this.isStreamOpenAllowed,
 isPrioritySupported: this.isPrioritySupported,
 isWrapped: this.isWrapped,
+applicationType: this.applicationType,
 lastDatagramId: this.lastDatagramId,
 },opts)}`;
 }

lib/internal/quic/symbols.js

@@ -23,7 +23,6 @@ const {
 // Symbols used to hide various private properties and methods from the
 // public API.
 
-constkApplicationProvider=Symbol('kApplicationProvider');
 constkBlocked=Symbol('kBlocked');
 constkConnect=Symbol('kConnect');
 constkDatagram=Symbol('kDatagram');
@@ -50,7 +49,6 @@ const kWantsHeaders = Symbol('kWantsHeaders');
 constkWantsTrailers=Symbol('kWantsTrailers');
 
 module.exports={
- kApplicationProvider,
  kBlocked,
  kConnect,
  kDatagram,

src/quic/application.cc

@@ -464,6 +464,10 @@ class DefaultApplication final : public Session::Application {
 // of the namespace.
 using Application::Application; // NOLINT
 
+ Session::Application::Type type() constoverride {
+return Session::Application::Type::DEFAULT;
+ }
+
  error_code GetNoErrorCode() constoverride { return0; }
 
 boolReceiveStreamData(int64_t stream_id,
@@ -601,14 +605,9 @@ class DefaultApplication final : public Session::Application {
  Stream::Queue stream_queue_;
 };
 
-std::unique_ptr<Session::Application> Session::SelectApplication(
- Session* session, const Config& config) {
-if (config.options.application_provider) {
-return config.options.application_provider->Create(session);
- }
-
-return std::make_unique<DefaultApplication>(session,
- Application_Options::kDefault);
+std::unique_ptr<Session::Application> CreateDefaultApplication(
+ Session* session, const Session::Application_Options& options) {
+return std::make_unique<DefaultApplication>(session, options);
 }
 
 } // namespace quic

src/quic/application.h

@@ -17,9 +17,19 @@ class Session::Application : public MemoryRetainer {
 public:
 using Options = Session::Application_Options;
 
+// The type of Application, exposed via the session state so JS
+// can observe which Application was selected after ALPN negotiation.
+enumclassType : uint8_t {
+NONE = 0, // Not yet selected (server pre-negotiation)
+DEFAULT = 1, // DefaultApplication (non-h3 ALPN)
+HTTP3 = 2, // Http3ApplicationImpl (h3 / h3-XX ALPN)
+ };
+
 Application(Session* session, const Options& options);
 DISALLOW_COPY_AND_MOVE(Application)
 
+virtual Type type() const = 0;
+
 virtualboolStart();
 
 virtual error_code GetNoErrorCode() const = 0;
@@ -169,6 +179,10 @@ struct Session::Application::StreamData final {
  std::string ToString() const;
 };
 
+// Create a DefaultApplication for the given session.
+std::unique_ptr<Session::Application> CreateDefaultApplication(
+ Session* session, const Session::Application_Options& options);
+
 } // namespace node::quic
 
 #endif// defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

src/quic/bindingdata.h

@@ -24,7 +24,6 @@ class Packet;
 // The FunctionTemplates the BindingData will store for us.
 #defineQUIC_CONSTRUCTORS(V) \
 V(endpoint) \
-V(http3application) \
 V(logstream) \
 V(session) \
 V(stream) \
@@ -59,7 +58,7 @@ class Packet;
 V(ack_delay_exponent, "ackDelayExponent") \
 V(active_connection_id_limit, "activeConnectionIDLimit") \
 V(address_lru_size, "addressLRUSize") \
-V(application_provider, "provider") \
+V(application, "application")  \
 V(bbr, "bbr") \
 V(ca, "ca") \
 V(cc_algorithm, "cc") \
@@ -78,7 +77,6 @@ class Packet;
 V(groups, "groups") \
 V(handshake_timeout, "handshakeTimeout") \
 V(http3_alpn, &NGHTTP3_ALPN_H3[1]) \
-V(http3application, "Http3Application") \
 V(initial_max_data, "initialMaxData") \
 V(initial_max_stream_data_bidi_local, "initialMaxStreamDataBidiLocal") \
 V(initial_max_stream_data_bidi_remote, "initialMaxStreamDataBidiRemote") \
@@ -105,7 +103,7 @@ class Packet;
 V(max_window, "maxWindow") \
 V(min_version, "minVersion") \
 V(preferred_address_strategy, "preferredAddressPolicy") \
-V(protocol, "protocol") \
+V(alpn, "alpn")  \
 V(qlog, "qlog") \
 V(qpack_blocked_streams, "qpackBlockedStreams") \
 V(qpack_encoder_max_dtable_capacity, "qpackEncoderMaxDTableCapacity") \

src/quic/endpoint.cc

@@ -92,7 +92,7 @@ bool is_diagnostic_packet_loss(double probability) {
 return (static_cast<double>(c) / 255) < probability;
 }
 
-template <typename Opt, double Opt::*member>
+template <typename Opt, double Opt::*member>
 boolSetOption(Environment* env,
  Opt* options,
 const Local<Object>& object,
@@ -113,7 +113,7 @@ bool SetOption(Environment* env,
 }
 #endif// DEBUG
 
-template <typename Opt, uint8_t Opt::*member>
+template <typename Opt, uint8_t Opt::*member>
 boolSetOption(Environment* env,
  Opt* options,
 const Local<Object>& object,
@@ -140,7 +140,7 @@ bool SetOption(Environment* env,
 returntrue;
 }
 
-template <typename Opt, TokenSecret Opt::*member>
+template <typename Opt, TokenSecret Opt::*member>
 boolSetOption(Environment* env,
  Opt* options,
 const Local<Object>& object,
@@ -511,7 +511,6 @@ JS_CONSTRUCTOR_IMPL(Endpoint, endpoint_constructor_template, {
 
 voidEndpoint::InitPerIsolate(IsolateData* data, Local<ObjectTemplate> target) {
 // TODO(@jasnell): Implement the per-isolate state
-Http3Application::InitPerIsolate(data, target);
 }
 
 voidEndpoint::InitPerContext(Realm* realm, Local<Object> target) {
@@ -567,8 +566,6 @@ void Endpoint::InitPerContext(Realm* realm, Local<Object> target) {
 NODE_DEFINE_CONSTANT(target, CLOSECONTEXT_SEND_FAILURE);
 NODE_DEFINE_CONSTANT(target, CLOSECONTEXT_START_FAILURE);
 
-Http3Application::InitPerContext(realm, target);
-
 SetConstructorFunction(realm->context(),
  target,
 "Endpoint",