http2: add origin frame support

v8.x Backport Note -- as V8 doesn't expose an overload of String::WriteOneByte
in Node 8 that accepts an isolate argument, the Origins constructor has been
changed to not accept an isolate.

Backport-PR-URL: #22850
PR-URL: #22956
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

doc/api/errors.md

@@ -737,6 +737,11 @@ An invalid HTTP/2 header value was specified.
 An invalid HTTP informational status code has been specified. Informational
 status codes must be an integer between `100` and `199` (inclusive).
 
+<a id="ERR_HTTP2_INVALID_ORIGIN"></a>
+### ERR_HTTP2_INVALID_ORIGIN
+
+HTTP/2 `ORIGIN` frames require a valid origin.
+
 <a id="ERR_HTTP2_INVALID_PACKED_SETTINGS_LENGTH"></a>
 ### ERR_HTTP2_INVALID_PACKED_SETTINGS_LENGTH
 
@@ -787,6 +792,11 @@ Nested push streams are not permitted.
 An attempt was made to directly manipulate (read, write, pause, resume, etc.) a
 socket attached to an `Http2Session`.
 
+<a id="ERR_HTTP2_ORIGIN_LENGTH"></a>
+### ERR_HTTP2_ORIGIN_LENGTH
+
+HTTP/2 `ORIGIN` frames are limited to a length of 16382 bytes.
+
 <a id="ERR_HTTP2_OUT_OF_STREAMS"></a>
 ### ERR_HTTP2_OUT_OF_STREAMS
 

doc/api/http2.md

@@ -423,6 +423,8 @@ If the `Http2Session` is connected to a `TLSSocket`, the `originSet` property
 will return an Array of origins for which the `Http2Session` may be
 considered authoritative.
 
+The `originSet` property is only available when using a secure TLS connection.
+
 #### http2session.pendingSettingsAck
 <!-- YAML
 added: v8.4.0
@@ -662,6 +664,56 @@ The protocol identifier (`'h2'` in the examples) may be any valid
 The syntax of these values is not validated by the Node.js implementation and
 are passed through as provided by the user or received from the peer.
 
+#### serverhttp2session.origin(...origins)
+<!-- YAML
+added: REPLACEME
+-->
+
+* `origins` { string | URL | Object } One or more URL Strings passed as
+  separate arguments.
+
+Submits an `ORIGIN` frame (as defined by [RFC 8336][]) to the connected client
+to advertise the set of origins for which the server is capable of providing
+authoritative responses.
+
+```js
+const http2 = require('http2');
+const options = getSecureOptionsSomehow();
+const server = http2.createSecureServer(options);
+server.on('stream', (stream) => {
+  stream.respond();
+  stream.end('ok');
+});
+server.on('session', (session) => {
+  session.origin('https://example.com', 'https://example.org');
+});
+```
+
+When a string is passed as an `origin`, it will be parsed as a URL and the
+origin will be derived. For instance, the origin for the HTTP URL
+`'https://example.org/foo/bar'` is the ASCII string
+`'https://example.org'`. An error will be thrown if either the given string
+cannot be parsed as a URL or if a valid origin cannot be derived.
+
+A `URL` object, or any object with an `origin` property, may be passed as
+an `origin`, in which case the value of the `origin` property will be
+used. The value of the `origin` property *must* be a properly serialized
+ASCII origin.
+
+Alternatively, the `origins` option may be used when creating a new HTTP/2
+server using the `http2.createSecureServer()` method:
+
+```js
+const http2 = require('http2');
+const options = getSecureOptionsSomehow();
+options.origins = ['https://example.com', 'https://example.org'];
+const server = http2.createSecureServer(options);
+server.on('stream', (stream) => {
+  stream.respond();
+  stream.end('ok');
+});
+```
+
 ### Class: ClientHttp2Session
 <!-- YAML
 added: v8.4.0
@@ -692,6 +744,30 @@ client.on('altsvc', (alt, origin, streamId) => {
 });
 ```
 
+#### Event: 'origin'
+<!-- YAML
+added: REPLACEME
+-->
+
+* `origins` {string[]}
+
+The `'origin'`  event is emitted whenever an `ORIGIN` frame is received by
+the client. The event is emitted with an array of `origin` strings. The
+`http2session.originSet` will be updated to include the received
+origins.
+
+```js
+const http2 = require('http2');
+const client = http2.connect('https://example.org');
+
+client.on('origin', (origins) => {
+  for (let n = 0; n < origins.length; n++)
+    console.log(origins[n]);
+});
+```
+
+The `'origin'` event is only emitted when using a secure TLS connection.
+
 #### clienthttp2session.request(headers[, options])
 <!-- YAML
 added: v8.4.0
@@ -1903,6 +1979,10 @@ server.listen(80);
 <!-- YAML
 added: v8.4.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/22956
+    description: Added the `origins` option to automatically send an `ORIGIN`
+                 frame on `Http2Session` startup.
   - version: v8.9.3
     pr-url: https://github.com/nodejs/node/pull/17105
     description: Added the `maxOutstandingPings` option with a default limit of
@@ -1966,6 +2046,8 @@ changes:
     remote peer upon connection.
   * ...: 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`
+    frame immediately following creation of a new server `Http2Session`.
 * `onRequestHandler` {Function} See [Compatibility API][]
 * Returns: {Http2SecureServer}
 
@@ -3282,6 +3364,7 @@ following additional properties:
 [Performance Observer]: perf_hooks.html
 [Readable Stream]: stream.html#stream_class_stream_readable
 [RFC 7838]: https://tools.ietf.org/html/rfc7838
+[RFC 8336]: https://tools.ietf.org/html/rfc8336
 [Using options.selectPadding]: #http2_using_options_selectpadding
 [Writable Stream]: stream.html#stream_writable_streams
 [`'checkContinue'`]: #http2_event_checkcontinue

lib/internal/errors.js

@@ -311,6 +311,7 @@ E('ERR_HTTP2_INVALID_CONNECTION_HEADERS',
 E('ERR_HTTP2_INVALID_HEADER_VALUE', 'Invalid value "%s" for header "%s"');
 E('ERR_HTTP2_INVALID_INFO_STATUS',
   (code) => `Invalid informational status code: ${code}`);
+E('ERR_HTTP2_INVALID_ORIGIN', 'HTTP/2 ORIGIN frames require a valid origin');
 E('ERR_HTTP2_INVALID_PACKED_SETTINGS_LENGTH',
   'Packed settings length must be a multiple of six');
 E('ERR_HTTP2_INVALID_PSEUDOHEADER',
@@ -325,6 +326,8 @@ E('ERR_HTTP2_NESTED_PUSH',
   'A push stream cannot initiate another push stream.', Error);
 E('ERR_HTTP2_NO_SOCKET_MANIPULATION',
   'HTTP/2 sockets should not be directly manipulated (e.g. read and written)');
+E('ERR_HTTP2_ORIGIN_LENGTH',
+  'HTTP/2 ORIGIN frames are limited to 16382 bytes');
 E('ERR_HTTP2_OUT_OF_STREAMS',
   'No stream ID is available because maximum stream ID has been reached');
 E('ERR_HTTP2_PAYLOAD_FORBIDDEN',

lib/internal/http2/core.js

@@ -90,6 +90,7 @@ const kMaybeDestroy = Symbol('maybe-destroy');
 const kLocalSettings = Symbol('local-settings');
 const kOptions = Symbol('options');
 const kOwner = Symbol('owner');
+const kOrigin = Symbol('origin');
 const kProceed = Symbol('proceed');
 const kProtocol = Symbol('protocol');
 const kProxySocket = Symbol('proxy-socket');
@@ -152,6 +153,7 @@ const {
   HTTP_STATUS_NO_CONTENT,
   HTTP_STATUS_NOT_MODIFIED,
   HTTP_STATUS_SWITCHING_PROTOCOLS,
+  HTTP_STATUS_MISDIRECTED_REQUEST,
 
   STREAM_OPTION_EMPTY_PAYLOAD,
   STREAM_OPTION_GET_TRAILERS
@@ -242,6 +244,11 @@ function onSessionHeaders(handle, id, cat, flags, headers) {
     } else {
       event = endOfStream ? 'trailers' : 'headers';
     }
+    const session = stream.session;
+    if (status === HTTP_STATUS_MISDIRECTED_REQUEST) {
+      const originSet = session[kState].originSet = initOriginSet(session);
+      originSet.delete(stream[kOrigin]);
+    }
     debug(`Http2Stream ${id} [Http2Session ` +
           `${sessionName(type)}]: emitting stream '${event}' event`);
     process.nextTick(emit, stream, event, obj, flags, headers);
@@ -404,6 +411,39 @@ function onAltSvc(stream, origin, alt) {
   session.emit('altsvc', alt, origin, stream);
 }
 
+function initOriginSet(session) {
+  let originSet = session[kState].originSet;
+  if (originSet === undefined) {
+    const socket = session[kSocket];
+    session[kState].originSet = originSet = new Set();
+    if (socket.servername != null) {
+      let originString = `https://${socket.servername}`;
+      if (socket.remotePort != null)
+        originString += `:${socket.remotePort}`;
+      // We have to ensure that it is a properly serialized
+      // ASCII origin string. The socket.servername might not
+      // be properly ASCII encoded.
+      originSet.add((new URL(originString)).origin);
+    }
+  }
+  return originSet;
+}
+
+function onOrigin(origins) {
+  const session = this[kOwner];
+  if (session.destroyed)
+    return;
+  debug(`Http2Session ${sessionName(session[kType])}: origin received: ` +
+        `${origins.join(', ')}`);
+  session[kUpdateTimer]();
+  if (!session.encrypted || session.destroyed)
+    return undefined;
+  const originSet = initOriginSet(session);
+  for (var n = 0; n < origins.length; n++)
+    originSet.add(origins[n]);
+  session.emit('origin', origins);
+}
+
 // Receiving a GOAWAY frame from the connected peer is a signal that no
 // new streams should be created. If the code === NGHTTP2_NO_ERROR, we
 // are going to send our close, but allow existing frames to close
@@ -766,6 +806,7 @@ function setupHandle(socket, type, options) {
   handle.onframeerror = onFrameError;
   handle.ongoawaydata = onGoawayData;
   handle.onaltsvc = onAltSvc;
+  handle.onorigin = onOrigin;
 
   if (typeof options.selectPadding === 'function')
     handle.ongetpadding = onSelectPadding(options.selectPadding);
@@ -792,6 +833,12 @@ function setupHandle(socket, type, options) {
     options.settings : {};
 
   this.settings(settings);
+
+  if (type === NGHTTP2_SESSION_SERVER &&
+      Array.isArray(options.origins)) {
+    this.origin(...options.origins);
+  }
+
   process.nextTick(emit, this, 'connect', this, socket);
 }
 
@@ -930,23 +977,7 @@ class Http2Session extends EventEmitter {
   get originSet() {
     if (!this.encrypted || this.destroyed)
       return undefined;
-
-    let originSet = this[kState].originSet;
-    if (originSet === undefined) {
-      const socket = this[kSocket];
-      this[kState].originSet = originSet = new Set();
-      if (socket.servername != null) {
-        let originString = `https://${socket.servername}`;
-        if (socket.remotePort != null)
-          originString += `:${socket.remotePort}`;
-        // We have to ensure that it is a properly serialized
-        // ASCII origin string. The socket.servername might not
-        // be properly ASCII encoded.
-        originSet.add((new URL(originString)).origin);
-      }
-    }
-
-    return Array.from(originSet);
+    return Array.from(initOriginSet(this));
   }
 
   // True if the Http2Session is still waiting for the socket to connect
@@ -1324,6 +1355,41 @@ class ServerHttp2Session extends Http2Session {
 
     this[kHandle].altsvc(stream, origin || '', alt);
   }
+
+  // Submits an origin frame to be sent.
+  origin(...origins) {
+    if (this.destroyed)
+      throw new errors.Error('ERR_HTTP2_INVALID_SESSION');
+
+    if (origins.length === 0)
+      return;
+
+    let arr = '';
+    let len = 0;
+    const count = origins.length;
+    for (var i = 0; i < count; i++) {
+      let origin = origins[i];
+      if (typeof origin === 'string') {
+        origin = (new URL(origin)).origin;
+      } else if (origin != null && typeof origin === 'object') {
+        origin = origin.origin;
+      }
+      if (typeof origin !== 'string')
+        throw new errors.Error('ERR_INVALID_ARG_TYPE', 'origin', 'string',
+                               origin);
+      if (origin === 'null')
+        throw new errors.Error('ERR_HTTP2_INVALID_ORIGIN');
+
+      arr += `${origin}\0`;
+      len += origin.length;
+    }
+
+    if (len > 16382)
+      throw new errors.Error('ERR_HTTP2_ORIGIN_LENGTH');
+
+    this[kHandle].origin(arr, count);
+  }
+
 }
 
 // ClientHttp2Session instances have to wait for the socket to connect after
@@ -1394,6 +1460,8 @@ class ClientHttp2Session extends Http2Session {
 
     const stream = new ClientHttp2Stream(this, undefined, undefined, {});
     stream[kSentHeaders] = headers;
+    stream[kOrigin] = `${headers[HTTP2_HEADER_SCHEME]}://` +
+                      `${headers[HTTP2_HEADER_AUTHORITY]}`;
 
     // Close the writable side of the stream if options.endStream is set.
     if (options.endStream)

src/env.h

@@ -219,6 +219,7 @@ class ModuleWrap;
   V(onnewsessiondone_string, "onnewsessiondone")                              \
   V(onocspresponse_string, "onocspresponse")                                  \
   V(ongoawaydata_string, "ongoawaydata")                                      \
+  V(onorigin_string, "onorigin")                                              \
   V(onpriority_string, "onpriority")                                          \
   V(onread_string, "onread")                                                  \
   V(onreadstart_string, "onreadstart")                                        \