http2: Receive customsettings

doc/api/http2.md

@@ -2498,6 +2498,11 @@ changes:
     **Default:** `100`.
   * `settings` {HTTP/2 Settings Object} The initial settings to send to the
     remote peer upon connection.
+  * `remoteCustomSettings` {Array} The array of integer values determines the
+    settings types, which are included in the `CustomSettings`-property of
+    the received remoteSettings. Please see the `CustomSettings`-property of
+    the `Http2Settings` object for more information,
+    on the allowed setting types.
   * `Http1IncomingMessage` {http.IncomingMessage} Specifies the
     `IncomingMessage` class to used for HTTP/1 fallback. Useful for extending
     the original `http.IncomingMessage`. **Default:** `http.IncomingMessage`.
@@ -2652,6 +2657,10 @@ changes:
     **Default:** `100`.
   * `settings` {HTTP/2 Settings Object} The initial settings to send to the
     remote peer upon connection.
+  * `remoteCustomSettings` {Array} The array of integer values determines the
+    settings types, which are included in the `customSettings`-property of the
+    received remoteSettings. Please see the `customSettings`-property of the
+    `Http2Settings` object for more information, on the allowed setting types.
   * ...: Any [`tls.createServer()`][] options can be provided. For
     servers, the identity options (`pfx` or `key`/`cert`) are usually required.
   * `origins` {string\[]} An array of origin strings to send within an `ORIGIN`
@@ -2780,6 +2789,10 @@ changes:
     `'https:'`
   * `settings` {HTTP/2 Settings Object} The initial settings to send to the
     remote peer upon connection.
+  * `remoteCustomSettings` {Array} The array of integer values determines the
+    settings types, which are included in the `CustomSettings`-property of the
+    received remoteSettings. Please see the `CustomSettings`-property of the
+    `Http2Settings` object for more information, on the allowed setting types.
   * `createConnection` {Function} An optional callback that receives the `URL`
     instance passed to `connect` and the `options` object, and returns any
     [`Duplex`][] stream that is to be used as the connection for this session.
@@ -3022,9 +3035,11 @@ properties.
   it should be greater than 6, although it is not an error.
   The values need to be unsigned integers in the range from 0 to 2^32-1.
   Currently, a maximum of up 10 custom settings is supported.
-  It is only supported for sending SETTINGS.
-  Custom settings are not supported for the functions retrieving remote and
-  local settings as nghttp2 does not pass unknown HTTP/2 settings to Node.js.
+  It is only supported for sending SETTINGS, or for receiving settings values
+  specified in the `remoteCustomSettings` options of the server or client
+  object. Do not mix the `customSettings`-mechanism for a settings id with
+  interfaces for the natively handled settings, in case a setting becomes
+  natively supported in a future node version.
 
 All additional properties on the settings object are ignored.
 

lib/internal/http2/core.js

@@ -9,9 +9,11 @@ const {
   FunctionPrototypeBind,
   FunctionPrototypeCall,
   MathMin,
+  Number,
   ObjectAssign,
   ObjectKeys,
   ObjectDefineProperty,
+  ObjectEntries,
   ObjectPrototypeHasOwnProperty,
   Promise,
   PromisePrototypeThen,
@@ -105,6 +107,7 @@ const {
     ERR_HTTP2_STREAM_CANCEL,
     ERR_HTTP2_STREAM_ERROR,
     ERR_HTTP2_STREAM_SELF_DEPENDENCY,
+    ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS,
     ERR_HTTP2_TRAILERS_ALREADY_SENT,
     ERR_HTTP2_TRAILERS_NOT_READY,
     ERR_HTTP2_UNSUPPORTED_PROTOCOL,
@@ -140,6 +143,7 @@ const {
 
 const {
   assertIsObject,
+  assertIsArray,
   assertValidPseudoHeader,
   assertValidPseudoHeaderResponse,
   assertValidPseudoHeaderTrailer,
@@ -155,7 +159,9 @@ const {
   kRequest,
   kProxySocket,
   mapToHeaders,
+  MAX_ADDITIONAL_SETTINGS,
   NghttpError,
+  remoteCustomSettingsToBuffer,
   sessionName,
   toHeaderObject,
   updateOptionsBuffer,
@@ -947,6 +953,15 @@ function pingCallback(cb) {
 const validateSettings = hideStackFrames((settings) => {
   if (settings === undefined) return;
   assertIsObject.withoutStackTrace(settings.customSettings, 'customSettings', 'Number');
+  if (settings.customSettings) {
+    const entries = ObjectEntries(settings.customSettings);
+    if (entries.length > MAX_ADDITIONAL_SETTINGS)
+      throw new ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS();
+    for (const { 0: key, 1: value } of entries) {
+      assertWithinRange.withoutStackTrace('customSettings:id', Number(key), 0, 0xffff);
+      assertWithinRange.withoutStackTrace('customSettings:value', Number(value), 0, kMaxInt);
+    }
+  }
 
   assertWithinRange.withoutStackTrace('headerTableSize',
                                       settings.headerTableSize,
@@ -1031,6 +1046,9 @@ function setupHandle(socket, type, options) {
   this[kState].flags |= SESSION_FLAGS_READY;
 
   updateOptionsBuffer(options);
+  if (options.remoteCustomSettings) {
+    remoteCustomSettingsToBuffer(options.remoteCustomSettings);
+  }
   const handle = new binding.Http2Session(type);
   handle[kOwner] = this;
 
@@ -3103,6 +3121,13 @@ function initializeOptions(options) {
   assertIsObject(options.settings, 'options.settings');
   options.settings = { ...options.settings };
 
+  assertIsArray(options.remoteCustomSettings, 'options.remoteCustomSettings');
+  if (options.remoteCustomSettings) {
+    options.remoteCustomSettings = [ ...options.remoteCustomSettings ];
+    if (options.remoteCustomSettings.length > MAX_ADDITIONAL_SETTINGS)
+      throw new ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS();
+  }
+
   if (options.maxSessionInvalidFrames !== undefined)
     validateUint32(options.maxSessionInvalidFrames, 'maxSessionInvalidFrames');
 
@@ -3277,6 +3302,13 @@ function connect(authority, options, listener) {
   assertIsObject(options, 'options');
   options = { ...options };
 
+  assertIsArray(options.remoteCustomSettings, 'options.remoteCustomSettings');
+  if (options.remoteCustomSettings) {
+    options.remoteCustomSettings = [ ...options.remoteCustomSettings ];
+    if (options.remoteCustomSettings.length > MAX_ADDITIONAL_SETTINGS)
+      throw new ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS();
+  }
+
   if (typeof authority === 'string')
     authority = new URL(authority);
 

lib/internal/http2/util.js

@@ -278,8 +278,19 @@ function updateOptionsBuffer(options) {
   optionsBuffer[IDX_OPTIONS_FLAGS] = flags;
 }
 
+function addCustomSettingsToObj() {
+  const toRet = {};
+  const num = settingsBuffer[IDX_SETTINGS_FLAGS + 1];
+  for (let i = 0; i < num; i++) {
+    toRet[settingsBuffer[IDX_SETTINGS_FLAGS + 1 + 2 * i + 1].toString()] =
+       Number(settingsBuffer[IDX_SETTINGS_FLAGS + 1 + 2 * i + 2]);
+  }
+  return toRet;
+}
+
 function getDefaultSettings() {
   settingsBuffer[IDX_SETTINGS_FLAGS] = 0;
+  settingsBuffer[IDX_SETTINGS_FLAGS + 1] = 0; // Length of custom settings
   binding.refreshDefaultSettings();
   const holder = { __proto__: null };
 
@@ -327,6 +338,8 @@ function getDefaultSettings() {
       settingsBuffer[IDX_SETTINGS_ENABLE_CONNECT_PROTOCOL] === 1;
   }
 
+  if (settingsBuffer[IDX_SETTINGS_FLAGS + 1]) holder.customSettings = addCustomSettingsToObj();
+
   return holder;
 }
 
@@ -338,7 +351,7 @@ function getSettings(session, remote) {
   else
     session.localSettings();
 
-  return {
+  const toRet = {
     headerTableSize: settingsBuffer[IDX_SETTINGS_HEADER_TABLE_SIZE],
     enablePush: !!settingsBuffer[IDX_SETTINGS_ENABLE_PUSH],
     initialWindowSize: settingsBuffer[IDX_SETTINGS_INITIAL_WINDOW_SIZE],
@@ -349,6 +362,8 @@ function getSettings(session, remote) {
     enableConnectProtocol:
       !!settingsBuffer[IDX_SETTINGS_ENABLE_CONNECT_PROTOCOL],
   };
+  if (settingsBuffer[IDX_SETTINGS_FLAGS + 1]) toRet.customSettings = addCustomSettingsToObj();
+  return toRet;
 }
 
 function updateSettingsBuffer(settings) {
@@ -415,12 +430,22 @@ function updateSettingsBuffer(settings) {
           }
         }
         if (!set) { // not supported
-          if (numCustomSettings === MAX_ADDITIONAL_SETTINGS)
-            throw new ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS();
+          let i = 0;
+          while (i < numCustomSettings) {
+            if (settingsBuffer[IDX_SETTINGS_FLAGS + 1 + 2 * i + 1] === nsetting) {
+              settingsBuffer[IDX_SETTINGS_FLAGS + 1 + 2 * i + 2] = val;
+              break;
+            }
+            i++;
+          }
+          if (i === numCustomSettings) {
+            if (numCustomSettings === MAX_ADDITIONAL_SETTINGS)
+              throw new ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS();
 
-          settingsBuffer[IDX_SETTINGS_FLAGS + 1 + 2 * numCustomSettings + 1] = nsetting;
-          settingsBuffer[IDX_SETTINGS_FLAGS + 1 + 2 * numCustomSettings + 2] = val;
-          numCustomSettings++;
+            settingsBuffer[IDX_SETTINGS_FLAGS + 1 + 2 * numCustomSettings + 1] = nsetting;
+            settingsBuffer[IDX_SETTINGS_FLAGS + 1 + 2 * numCustomSettings + 2] = val;
+            numCustomSettings++;
+          }
         }
       }
     }
@@ -475,6 +500,24 @@ function updateSettingsBuffer(settings) {
   settingsBuffer[IDX_SETTINGS_FLAGS] = flags;
 }
 
+function remoteCustomSettingsToBuffer(remoteCustomSettings) {
+  if (remoteCustomSettings.length > MAX_ADDITIONAL_SETTINGS)
+    throw new ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS();
+  let numCustomSettings = 0;
+  for (let i = 0; i < remoteCustomSettings.length; i++) {
+    const nsetting = remoteCustomSettings[i];
+    if (typeof nsetting === 'number' && nsetting <= 0xffff &&
+        nsetting >= 0) {
+      settingsBuffer[IDX_SETTINGS_FLAGS + 1 + 2 * numCustomSettings + 1] = nsetting;
+      numCustomSettings++;
+    } else
+      throw new ERR_HTTP2_INVALID_SETTING_VALUE.RangeError(
+        'Range Error', nsetting, 0, 0xffff);
+
+  }
+  settingsBuffer[IDX_SETTINGS_FLAGS + 1] = numCustomSettings;
+}
+
 function getSessionState(session) {
   session.refreshState();
   return {
@@ -649,6 +692,14 @@ const assertIsObject = hideStackFrames((value, name, types) => {
   }
 });
 
+const assertIsArray = hideStackFrames((value, name, types) => {
+  if (value !== undefined &&
+      (value === null ||
+       !ArrayIsArray(value))) {
+    throw new ERR_INVALID_ARG_TYPE.HideStackFramesError(name, types || 'Array', value);
+  }
+});
+
 const assertWithinRange = hideStackFrames(
   (name, value, min = 0, max = Infinity) => {
     if (value !== undefined &&
@@ -732,6 +783,7 @@ function getAuthority(headers) {
 
 module.exports = {
   assertIsObject,
+  assertIsArray,
   assertValidPseudoHeader,
   assertValidPseudoHeaderResponse,
   assertValidPseudoHeaderTrailer,
@@ -747,7 +799,9 @@ module.exports = {
   kProxySocket,
   kRequest,
   mapToHeaders,
+  MAX_ADDITIONAL_SETTINGS,
   NghttpError,
+  remoteCustomSettingsToBuffer,
   sessionName,
   toHeaderObject,
   updateOptionsBuffer,