From 9590f577b03f621faf35f60e439b87431d293dee Mon Sep 17 00:00:00 2001
From: Denys Otrishko <shishugi@gmail.com>
Date: Mon, 18 Nov 2019 21:44:21 +0200
Subject: [PATCH] http2: allow to configure maximum tolerated invalid frames

PR-URL: https://github.com/nodejs/node/pull/30534
Fixes: https://github.com/nodejs/node/issues/30505
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 doc/api/http2.md                              | 12 +++
 lib/internal/http2/core.js                    | 16 +++-
 src/node_http2.cc                             |  9 +-
 src/node_http2.h                              |  4 +-
 .../test-http2-createsecureserver-options.js  | 31 ++++++-
 .../test-http2-createserver-options.js        | 31 ++++++-
 .../parallel/test-http2-max-invalid-frames.js | 86 +++++++++++++++++++
 7 files changed, 181 insertions(+), 8 deletions(-)
 create mode 100644 test/parallel/test-http2-max-invalid-frames.js

diff --git a/doc/api/http2.md b/doc/api/http2.md
index 53461ac58d4605..7ac4f6ffa129f5 100644
--- a/doc/api/http2.md
+++ b/doc/api/http2.md
@@ -1941,6 +1941,9 @@ error will be thrown.
 <!-- YAML
 added: v8.4.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/30534
+    description: Added `maxSessionInvalidFrames` option with a default of 1000.
   - version: v13.0.0
     pr-url: https://github.com/nodejs/node/pull/29144
     description: The `PADDING_STRATEGY_CALLBACK` has been made equivalent to
@@ -2001,6 +2004,9 @@ changes:
     streams for the remote peer as if a `SETTINGS` frame had been received. Will
     be overridden if the remote peer sets its own value for
     `maxConcurrentStreams`. **Default:** `100`.
+  * `maxSessionInvalidFrames` {integer} Sets the maximum number of invalid
+    frames that will be tolerated before the session is closed.
+    **Default:** `1000`.
   * `settings` {HTTP/2 Settings Object} The initial settings to send to the
     remote peer upon connection.
   * `Http1IncomingMessage` {http.IncomingMessage} Specifies the
@@ -2053,6 +2059,9 @@ server.listen(80);
 <!-- YAML
 added: v8.4.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/30534
+    description: Added `maxSessionInvalidFrames` option with a default of 1000.
   - version: v13.0.0
     pr-url: https://github.com/nodejs/node/pull/29144
     description: The `PADDING_STRATEGY_CALLBACK` has been made equivalent to
@@ -2113,6 +2122,9 @@ changes:
     streams for the remote peer as if a `SETTINGS` frame had been received. Will
     be overridden if the remote peer sets its own value for
     `maxConcurrentStreams`. **Default:** `100`.
+  * `maxSessionInvalidFrames` {integer} Sets the maximum number of invalid
+    frames that will be tolerated before the session is closed.
+    **Default:** `1000`.
   * `settings` {HTTP/2 Settings Object} The initial settings to send to the
     remote peer upon connection.
   * ...: Any [`tls.createServer()`][] options can be provided. For
diff --git a/lib/internal/http2/core.js b/lib/internal/http2/core.js
index 4060aff75e91a3..7eaf1f4e9249b3 100644
--- a/lib/internal/http2/core.js
+++ b/lib/internal/http2/core.js
@@ -90,7 +90,11 @@ const {
   },
   hideStackFrames
 } = require('internal/errors');
-const { validateNumber, validateString } = require('internal/validators');
+const { validateNumber,
+        validateString,
+        validateUint32,
+        isUint32,
+} = require('internal/validators');
 const fsPromisesInternal = require('internal/fs/promises');
 const { utcDate } = require('internal/http');
 const { onServerStream,
@@ -206,6 +210,7 @@ const {
   kBitfield,
   kSessionPriorityListenerCount,
   kSessionFrameErrorListenerCount,
+  kSessionMaxInvalidFrames,
   kSessionUint8FieldCount,
   kSessionHasRemoteSettingsListeners,
   kSessionRemoteSettingsIsUpToDate,
@@ -944,6 +949,12 @@ function setupHandle(socket, type, options) {
     this[kEncrypted] = false;
   }
 
+  if (isUint32(options.maxSessionInvalidFrames)) {
+    const uint32 = new Uint32Array(
+      this[kNativeFields].buffer, kSessionMaxInvalidFrames, 1);
+    uint32[0] = options.maxSessionInvalidFrames;
+  }
+
   const settings = typeof options.settings === 'object' ?
     options.settings : {};
 
@@ -2774,6 +2785,9 @@ function initializeOptions(options) {
   assertIsObject(options.settings, 'options.settings');
   options.settings = { ...options.settings };
 
+  if (options.maxSessionInvalidFrames !== undefined)
+    validateUint32(options.maxSessionInvalidFrames, 'maxSessionInvalidFrames');
+
   // Used only with allowHTTP1
   options.Http1IncomingMessage = options.Http1IncomingMessage ||
     http.IncomingMessage;
diff --git a/src/node_http2.cc b/src/node_http2.cc
index 4c1e5dd5831b81..459cc3b0e605ef 100644
--- a/src/node_http2.cc
+++ b/src/node_http2.cc
@@ -1011,8 +1011,12 @@ int Http2Session::OnInvalidFrame(nghttp2_session* handle,
                                  void* user_data) {
   Http2Session* session = static_cast<Http2Session*>(user_data);
 
-  Debug(session, "invalid frame received, code: %d", lib_error_code);
-  if (session->invalid_frame_count_++ > 1000)
+  Debug(session,
+        "invalid frame received (%u/%u), code: %d",
+        session->invalid_frame_count_,
+        session->js_fields_.max_invalid_frames,
+        lib_error_code);
+  if (session->invalid_frame_count_++ > session->js_fields_.max_invalid_frames)
     return 1;
 
   // If the error is fatal or if error code is ERR_STREAM_CLOSED... emit error
@@ -3057,6 +3061,7 @@ void Initialize(Local<Object> target,
   NODE_DEFINE_CONSTANT(target, kBitfield);
   NODE_DEFINE_CONSTANT(target, kSessionPriorityListenerCount);
   NODE_DEFINE_CONSTANT(target, kSessionFrameErrorListenerCount);
+  NODE_DEFINE_CONSTANT(target, kSessionMaxInvalidFrames);
   NODE_DEFINE_CONSTANT(target, kSessionUint8FieldCount);
 
   NODE_DEFINE_CONSTANT(target, kSessionHasRemoteSettingsListeners);
diff --git a/src/node_http2.h b/src/node_http2.h
index 61092b60c0cb6e..79d648276fe91e 100644
--- a/src/node_http2.h
+++ b/src/node_http2.h
@@ -677,6 +677,7 @@ typedef struct {
   uint8_t bitfield;
   uint8_t priority_listener_count;
   uint8_t frame_error_listener_count;
+  uint32_t max_invalid_frames = 1000;
 } SessionJSFields;
 
 // Indices for js_fields_, which serves as a way to communicate data with JS
@@ -689,6 +690,7 @@ enum SessionUint8Fields {
       offsetof(SessionJSFields, priority_listener_count),
   kSessionFrameErrorListenerCount =
       offsetof(SessionJSFields, frame_error_listener_count),
+  kSessionMaxInvalidFrames = offsetof(SessionJSFields, max_invalid_frames),
   kSessionUint8FieldCount = sizeof(SessionJSFields)
 };
 
@@ -1024,7 +1026,7 @@ class Http2Session : public AsyncWrap, public StreamListener {
   // accepted again.
   int32_t rejected_stream_count_ = 0;
   // Also use the invalid frame count as a measure for rejecting input frames.
-  int32_t invalid_frame_count_ = 0;
+  uint32_t invalid_frame_count_ = 0;
 
   void PushOutgoingBuffer(nghttp2_stream_write&& write);
   void CopyDataIntoOutgoing(const uint8_t* src, size_t src_length);
diff --git a/test/parallel/test-http2-createsecureserver-options.js b/test/parallel/test-http2-createsecureserver-options.js
index 4ef85a45b5b84b..b97d6e5d6c99d5 100644
--- a/test/parallel/test-http2-createsecureserver-options.js
+++ b/test/parallel/test-http2-createsecureserver-options.js
@@ -7,7 +7,7 @@ if (!common.hasCrypto)
 const assert = require('assert');
 const http2 = require('http2');
 
-// Error if invalid options are passed to createSecureServer
+// Error if invalid options are passed to createSecureServer.
 const invalidOptions = [() => {}, 1, 'test', null, Symbol('test')];
 invalidOptions.forEach((invalidOption) => {
   assert.throws(
@@ -21,7 +21,7 @@ invalidOptions.forEach((invalidOption) => {
   );
 });
 
-// Error if invalid options.settings are passed to createSecureServer
+// Error if invalid options.settings are passed to createSecureServer.
 invalidOptions.forEach((invalidSettingsOption) => {
   assert.throws(
     () => http2.createSecureServer({ settings: invalidSettingsOption }),
@@ -33,3 +33,30 @@ invalidOptions.forEach((invalidSettingsOption) => {
     }
   );
 });
+
+// Test that http2.createSecureServer validates input options.
+Object.entries({
+  maxSessionInvalidFrames: [
+    {
+      val: -1,
+      err: {
+        name: 'RangeError',
+        code: 'ERR_OUT_OF_RANGE',
+      },
+    },
+    {
+      val: Number.NEGATIVE_INFINITY,
+      err: {
+        name: 'RangeError',
+        code: 'ERR_OUT_OF_RANGE',
+      },
+    },
+  ],
+}).forEach(([opt, tests]) => {
+  tests.forEach(({ val, err }) => {
+    assert.throws(
+      () => http2.createSecureServer({ [opt]: val }),
+      err
+    );
+  });
+});
diff --git a/test/parallel/test-http2-createserver-options.js b/test/parallel/test-http2-createserver-options.js
index d322506f55e3e0..47504a8a779ea2 100644
--- a/test/parallel/test-http2-createserver-options.js
+++ b/test/parallel/test-http2-createserver-options.js
@@ -7,7 +7,7 @@ if (!common.hasCrypto)
 const assert = require('assert');
 const http2 = require('http2');
 
-// Error if invalid options are passed to createServer
+// Error if invalid options are passed to createServer.
 const invalidOptions = [1, true, 'test', null, Symbol('test')];
 invalidOptions.forEach((invalidOption) => {
   assert.throws(
@@ -21,7 +21,7 @@ invalidOptions.forEach((invalidOption) => {
   );
 });
 
-// Error if invalid options.settings are passed to createServer
+// Error if invalid options.settings are passed to createServer.
 invalidOptions.forEach((invalidSettingsOption) => {
   assert.throws(
     () => http2.createServer({ settings: invalidSettingsOption }),
@@ -33,3 +33,30 @@ invalidOptions.forEach((invalidSettingsOption) => {
     }
   );
 });
+
+// Test that http2.createServer validates input options.
+Object.entries({
+  maxSessionInvalidFrames: [
+    {
+      val: -1,
+      err: {
+        name: 'RangeError',
+        code: 'ERR_OUT_OF_RANGE',
+      },
+    },
+    {
+      val: Number.NEGATIVE_INFINITY,
+      err: {
+        name: 'RangeError',
+        code: 'ERR_OUT_OF_RANGE',
+      },
+    },
+  ],
+}).forEach(([opt, tests]) => {
+  tests.forEach(({ val, err }) => {
+    assert.throws(
+      () => http2.createServer({ [opt]: val }),
+      err
+    );
+  });
+});
diff --git a/test/parallel/test-http2-max-invalid-frames.js b/test/parallel/test-http2-max-invalid-frames.js
new file mode 100644
index 00000000000000..597bd8e81197b5
--- /dev/null
+++ b/test/parallel/test-http2-max-invalid-frames.js
@@ -0,0 +1,86 @@
+'use strict';
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+
+const assert = require('assert');
+const http2 = require('http2');
+const net = require('net');
+
+// Verify that creating a number of invalid HTTP/2 streams will
+// result in the peer closing the session within maxSessionInvalidFrames
+// frames.
+
+const maxSessionInvalidFrames = 100;
+const server = http2.createServer({ maxSessionInvalidFrames });
+server.on('stream', (stream) => {
+  stream.respond({
+    'content-type': 'text/plain',
+    ':status': 200
+  });
+  stream.end('Hello, world!\n');
+});
+
+server.listen(0, () => {
+  const h2header = Buffer.alloc(9);
+  const conn = net.connect(server.address().port);
+
+  conn.write('PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n');
+
+  h2header[3] = 4;  // Send a settings frame.
+  conn.write(Buffer.from(h2header));
+
+  let inbuf = Buffer.alloc(0);
+  let state = 'settingsHeader';
+  let settingsFrameLength;
+  conn.on('data', (chunk) => {
+    inbuf = Buffer.concat([inbuf, chunk]);
+    switch (state) {
+      case 'settingsHeader':
+        if (inbuf.length < 9) return;
+        settingsFrameLength = inbuf.readIntBE(0, 3);
+        inbuf = inbuf.slice(9);
+        state = 'readingSettings';
+        // Fallthrough
+      case 'readingSettings':
+        if (inbuf.length < settingsFrameLength) return;
+        inbuf = inbuf.slice(settingsFrameLength);
+        h2header[3] = 4;  // Send a settings ACK.
+        h2header[4] = 1;
+        conn.write(Buffer.from(h2header));
+        state = 'ignoreInput';
+        writeRequests();
+    }
+  });
+
+  let gotError = false;
+  let streamId = 1;
+  let reqCount = 0;
+
+  function writeRequests() {
+    for (let i = 1; i < 10 && !gotError; i++) {
+      h2header[3] = 1;  // HEADERS
+      h2header[4] = 0x5;  // END_HEADERS|END_STREAM
+      h2header.writeIntBE(1, 0, 3);  // Length: 1
+      h2header.writeIntBE(streamId, 5, 4);  // Stream ID
+      streamId += 2;
+      // 0x88 = :status: 200
+      if (!conn.write(Buffer.concat([h2header, Buffer.from([0x88])]))) {
+        break;
+      }
+      reqCount++;
+    }
+    // Timeout requests to slow down the rate so we get more accurate reqCount.
+    if (!gotError)
+      setTimeout(writeRequests, 10);
+  }
+
+  conn.once('error', common.mustCall(() => {
+    gotError = true;
+    assert.ok(Math.abs(reqCount - maxSessionInvalidFrames) < 100,
+              `Request count (${reqCount}) must be around (±100)` +
+      ` maxSessionInvalidFrames option (${maxSessionInvalidFrames})`);
+    conn.destroy();
+    server.close();
+  }));
+});