http2: support non-empty DATA frame with END_STREAM flag

Adds support for reading from a stream where the final frame is a
non-empty DATA frame with the END_STREAM flag set, instead of hanging
waiting for another frame.

Fixes: #31309
Refs: https://nghttp2.org/documentation/types.html#c.nghttp2_on_data_chunk_recv_callback

PR-URL: #33875
Backport-PR-URL: #34857
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: clshortfuse

src/node_http2.cc

@@ -882,7 +882,7 @@ ssize_t Http2Session::OnCallbackPadding(size_t frameLen,
 // quite expensive. This is a potential performance optimization target later.
 ssize_t Http2Session::ConsumeHTTP2Data() {
   CHECK_NOT_NULL(stream_buf_.base);
-  CHECK_LT(stream_buf_offset_, stream_buf_.len);
+  CHECK_LE(stream_buf_offset_, stream_buf_.len);
   size_t read_len = stream_buf_.len - stream_buf_offset_;
 
   // multiple side effects.
@@ -903,11 +903,11 @@ ssize_t Http2Session::ConsumeHTTP2Data() {
     CHECK_GT(ret, 0);
     CHECK_LE(static_cast<size_t>(ret), read_len);
 
-    if (static_cast<size_t>(ret) < read_len) {
-      // Mark the remainder of the data as available for later consumption.
-      stream_buf_offset_ += ret;
-      return ret;
-    }
+    // Mark the remainder of the data as available for later consumption.
+    // Even if all bytes were received, a paused stream may delay the
+    // nghttp2_on_frame_recv_callback which may have an END_STREAM flag.
+    stream_buf_offset_ += ret;
+    return ret;
   }
 
   // We are done processing the current input chunk.
@@ -1241,6 +1241,7 @@ int Http2Session::OnDataChunkReceived(nghttp2_session* handle,
   if (session->flags_ & SESSION_STATE_WRITE_IN_PROGRESS) {
     CHECK_NE(session->flags_ & SESSION_STATE_READING_STOPPED, 0);
     session->flags_ |= SESSION_STATE_NGHTTP2_RECV_PAUSED;
+    Debug(session, "receive paused");
     return NGHTTP2_ERR_PAUSE;
   }
 

test/parallel/test-http2-misbehaving-multiplex.js

@@ -2,6 +2,7 @@
 // Flags: --expose-internals
 
 const common = require('../common');
+const assert = require('assert');
 
 if (!common.hasCrypto)
   common.skip('missing crypto');
@@ -13,16 +14,36 @@ const h2test = require('../common/http2');
 let client;
 
 const server = h2.createServer();
+let gotFirstStreamId1;
 server.on('stream', common.mustCall((stream) => {
   stream.respond();
   stream.end('ok');
 
-  // the error will be emitted asynchronously
-  stream.on('error', common.expectsError({
-    type: NghttpError,
-    code: 'ERR_HTTP2_ERROR',
-    message: 'Stream was already closed or invalid'
-  }));
+  // Http2Server should be fast enough to respond to and close
+  // the first streams with ID 1 and ID 3 without errors.
+
+  // Test for errors in 'close' event to ensure no errors on some streams.
+  stream.on('error', () => {});
+  stream.on('close', (err) => {
+    if (stream.id === 1) {
+      if (gotFirstStreamId1) {
+        // We expect our outgoing frames to fail on Stream ID 1 the second time
+        // because a stream with ID 1 was already closed before.
+        common.expectsError({
+          constructor: NghttpError,
+          code: 'ERR_HTTP2_ERROR',
+          message: 'Stream was already closed or invalid'
+        });
+        return;
+      }
+      gotFirstStreamId1 = true;
+    }
+    assert.strictEqual(err, undefined);
+  });
+
+  // Stream ID 5 should never reach the server
+  assert.notStrictEqual(stream.id, 5);
+
 }, 2));
 
 server.on('session', common.mustCall((session) => {
@@ -35,26 +56,27 @@ server.on('session', common.mustCall((session) => {
 
 const settings = new h2test.SettingsFrame();
 const settingsAck = new h2test.SettingsFrame(true);
-const head1 = new h2test.HeadersFrame(1, h2test.kFakeRequestHeaders, 0, true);
-const head2 = new h2test.HeadersFrame(3, h2test.kFakeRequestHeaders, 0, true);
-const head3 = new h2test.HeadersFrame(1, h2test.kFakeRequestHeaders, 0, true);
-const head4 = new h2test.HeadersFrame(5, h2test.kFakeRequestHeaders, 0, true);
+// HeadersFrame(id, payload, padding, END_STREAM)
+const id1 = new h2test.HeadersFrame(1, h2test.kFakeRequestHeaders, 0, true);
+const id3 = new h2test.HeadersFrame(3, h2test.kFakeRequestHeaders, 0, true);
+const id5 = new h2test.HeadersFrame(5, h2test.kFakeRequestHeaders, 0, true);
 
 server.listen(0, () => {
   client = net.connect(server.address().port, () => {
     client.write(h2test.kClientMagic, () => {
       client.write(settings.data, () => {
         client.write(settingsAck.data);
-        // This will make it ok.
-        client.write(head1.data, () => {
-          // This will make it ok.
-          client.write(head2.data, () => {
+        // Stream ID 1 frame will make it OK.
+        client.write(id1.data, () => {
+          // Stream ID 3 frame will make it OK.
+          client.write(id3.data, () => {
+            // A second Stream ID 1 frame should fail.
             // This will cause an error to occur because the client is
             // attempting to reuse an already closed stream. This must
             // cause the server session to be torn down.
-            client.write(head3.data, () => {
-              // This won't ever make it to the server
-              client.write(head4.data);
+            client.write(id1.data, () => {
+              // This Stream ID 5 frame will never make it to the server
+              client.write(id5.data);
             });
           });
         });

test/parallel/test-http2-pack-end-stream-flag.js

@@ -0,0 +1,65 @@
+'use strict';
+
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+const assert = require('assert');
+const http2 = require('http2');
+
+const { PerformanceObserver } = require('perf_hooks');
+
+const server = http2.createServer();
+
+server.on('stream', (stream, headers) => {
+  stream.respond({
+    'content-type': 'text/html',
+    ':status': 200
+  });
+  switch (headers[':path']) {
+    case '/singleEnd':
+      stream.end('OK');
+      // Backport v10.x: Manually pack END_STREAM flag
+      stream._final(() => {});
+      break;
+    case '/sequentialEnd':
+      stream.write('OK');
+      stream.end();
+      // Backport v10.x: Manually pack END_STREAM flag
+      stream._final(() => {});
+      break;
+    case '/delayedEnd':
+      stream.write('OK', () => stream.end());
+      break;
+  }
+});
+
+function testRequest(path, targetFrameCount, callback) {
+  const obs = new PerformanceObserver((list, observer) => {
+    const entry = list.getEntries()[0];
+    if (entry.name !== 'Http2Session') return;
+    if (entry.type !== 'client') return;
+    assert.strictEqual(entry.framesReceived, targetFrameCount);
+    observer.disconnect();
+    callback();
+  });
+  obs.observe({ entryTypes: ['http2'] });
+  const client = http2.connect(`http://localhost:${server.address().port}`, () => {
+    const req = client.request({ ':path': path });
+    req.resume();
+    req.end();
+    req.on('end', () => client.close());
+  });
+}
+
+// SETTINGS => SETTINGS => HEADERS => DATA
+const MIN_FRAME_COUNT = 4;
+
+server.listen(0, () => {
+  testRequest('/singleEnd', MIN_FRAME_COUNT, () => {
+    testRequest('/sequentialEnd', MIN_FRAME_COUNT, () => {
+      testRequest('/delayedEnd', MIN_FRAME_COUNT + 1, () => {
+        server.close();
+      });
+    });
+  });
+});