http2: addtl http/2 settings

Currently, node.js http/2 is limited in sending SETTINGs, that are currently implemented by nghttp2. However, nghttp2 has the ability to send arbitary SETTINGs, that are not known beforehand. This patch adds this feature including a fall back mechanism, if a SETTING is implemented in a later nghttp2 or node version. Fixes: #1337 PR-URL: #49025 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Marco Ippolito <[email protected]>

Author: martenrichter

doc/api/errors.md

@@ -1710,6 +1710,12 @@ When setting the priority for an HTTP/2 stream, the stream may be marked as
 a dependency for a parent stream. This error code is used when an attempt is
 made to mark a stream and dependent of itself.
 
+<aid="ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS"></a>
+
+### `ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS`
+
+The number of supported custom settings (10) has been exceeded.
+
 <aid="ERR_HTTP2_TOO_MANY_INVALID_FRAMES"></a>
 
 ### `ERR_HTTP2_TOO_MANY_INVALID_FRAMES`

doc/api/http2.md

@@ -3010,6 +3010,19 @@ properties.
  meaningful if sent by the server. Once the `enableConnectProtocol` setting
  has been enabled for a given `Http2Session`, it cannot be disabled.
 **Default:**`false`.
+*`customSettings`{Object} Specifies additional settings, yet not implemented
+ in node and the underlying libraries. The key of the object defines the
+ numeric value of the settings type (as defined in the "HTTP/2 SETTINGS"
+ registry established by \[RFC 7540]) and the values the actual numeric value
+ of the settings.
+ The settings type has to be an integer in the range from 1 to 2^16-1.
+ It should not be a settings type already handled by node, i.e. currently
+ 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.
 
 All additional properties on the settings object are ignored.
 

lib/internal/errors.js

@@ -1279,6 +1279,8 @@ E('ERR_HTTP2_STREAM_CANCEL', function(error){
 E('ERR_HTTP2_STREAM_ERROR','Stream closed with error code %s',Error);
 E('ERR_HTTP2_STREAM_SELF_DEPENDENCY',
 'A stream cannot depend on itself',Error);
+E('ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS',
+'Number of custom settings exceeds MAX_ADDITIONAL_SETTINGS',Error);
 E('ERR_HTTP2_TOO_MANY_INVALID_FRAMES','Too many invalid HTTP/2 frames',Error);
 E('ERR_HTTP2_TRAILERS_ALREADY_SENT',
 'Trailing headers have already been sent',Error);

lib/internal/http2/core.js

@@ -946,6 +946,8 @@ function pingCallback(cb){
 // All settings are optional and may be left undefined
 constvalidateSettings=hideStackFrames((settings)=>{
 if(settings===undefined)return;
+assertIsObject.withoutStackTrace(settings.customSettings,'customSettings','Number');
+
 assertWithinRange.withoutStackTrace('headerTableSize',
 settings.headerTableSize,
 0,kMaxInt);
@@ -3387,6 +3389,10 @@ function getUnpackedSettings(buf, options = kEmptyObject){
 break;
 caseNGHTTP2_SETTINGS_ENABLE_CONNECT_PROTOCOL:
 settings.enableConnectProtocol=value!==0;
+break;
+default:
+if(!settings.customSettings)settings.customSettings={};
+settings.customSettings[id]=value;
 }
 offset+=4;
 }

lib/internal/http2/util.js

@@ -8,6 +8,7 @@ const{
  Error,
  MathMax,
  Number,
+ NumberIsNaN,
  ObjectKeys,
  SafeSet,
  String,
@@ -24,6 +25,7 @@ const{
 ERR_HTTP2_INVALID_CONNECTION_HEADERS,
 ERR_HTTP2_INVALID_PSEUDOHEADER: {HideStackFramesError: ERR_HTTP2_INVALID_PSEUDOHEADER},
 ERR_HTTP2_INVALID_SETTING_VALUE,
+ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS,
 ERR_INVALID_ARG_TYPE,
 ERR_INVALID_HTTP_TOKEN,
 },
@@ -190,6 +192,9 @@ const IDX_SETTINGS_MAX_HEADER_LIST_SIZE = 5;
 constIDX_SETTINGS_ENABLE_CONNECT_PROTOCOL=6;
 constIDX_SETTINGS_FLAGS=7;
 
+// Maximum number of allowed additional settings
+constMAX_ADDITIONAL_SETTINGS=10;
+
 constIDX_SESSION_STATE_EFFECTIVE_LOCAL_WINDOW_SIZE=0;
 constIDX_SESSION_STATE_EFFECTIVE_RECV_DATA_LENGTH=1;
 constIDX_SESSION_STATE_NEXT_STREAM_ID=2;
@@ -348,6 +353,80 @@ function getSettings(session, remote){
 
 functionupdateSettingsBuffer(settings){
 letflags=0;
+letnumCustomSettings=0;
+
+if(typeofsettings.customSettings==='object'){
+constcustomSettings=settings.customSettings;
+for(constsettingincustomSettings){
+constval=customSettings[setting];
+if(typeofval==='number'){
+letset=false;
+constnsetting=Number(setting);
+if(NumberIsNaN(nsetting)||
+typeofnsetting!=='number'||
+0>=nsetting||
+nsetting>0xffff)
+thrownewERR_HTTP2_INVALID_SETTING_VALUE.RangeError(
+'Range Error',nsetting,0,0xffff);
+if(NumberIsNaN(val)||
+typeofval!=='number'||
+0>=val||
+val>0xffffffff)
+thrownewERR_HTTP2_INVALID_SETTING_VALUE.RangeError(
+'Range Error',val,0,0xffffffff);
+if(nsetting<IDX_SETTINGS_FLAGS){
+set=true;
+switch(nsetting){
+caseIDX_SETTINGS_HEADER_TABLE_SIZE:
+flags|=(1<<IDX_SETTINGS_HEADER_TABLE_SIZE);
+settingsBuffer[IDX_SETTINGS_HEADER_TABLE_SIZE]=
+val;
+break;
+caseIDX_SETTINGS_ENABLE_PUSH:
+flags|=(1<<IDX_SETTINGS_ENABLE_PUSH);
+settingsBuffer[IDX_SETTINGS_ENABLE_PUSH]=val;
+break;
+caseIDX_SETTINGS_INITIAL_WINDOW_SIZE:
+flags|=(1<<IDX_SETTINGS_INITIAL_WINDOW_SIZE);
+settingsBuffer[IDX_SETTINGS_INITIAL_WINDOW_SIZE]=
+val;
+break;
+caseIDX_SETTINGS_MAX_FRAME_SIZE:
+flags|=(1<<IDX_SETTINGS_MAX_FRAME_SIZE);
+settingsBuffer[IDX_SETTINGS_MAX_FRAME_SIZE]=
+val;
+break;
+caseIDX_SETTINGS_MAX_CONCURRENT_STREAMS:
+flags|=(1<<IDX_SETTINGS_MAX_CONCURRENT_STREAMS);
+settingsBuffer[IDX_SETTINGS_MAX_CONCURRENT_STREAMS]=val;
+break;
+caseIDX_SETTINGS_MAX_HEADER_LIST_SIZE:
+flags|=(1<<IDX_SETTINGS_MAX_HEADER_LIST_SIZE);
+settingsBuffer[IDX_SETTINGS_MAX_HEADER_LIST_SIZE]=
+val;
+break;
+caseIDX_SETTINGS_ENABLE_CONNECT_PROTOCOL:
+flags|=(1<<IDX_SETTINGS_ENABLE_CONNECT_PROTOCOL);
+settingsBuffer[IDX_SETTINGS_ENABLE_CONNECT_PROTOCOL]=val;
+break;
+default:
+set=false;
+break;
+}
+}
+if(!set){// not supported
+if(numCustomSettings===MAX_ADDITIONAL_SETTINGS)
+thrownewERR_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]=numCustomSettings;
+
 if(typeofsettings.headerTableSize==='number'){
 flags|=(1<<IDX_SETTINGS_HEADER_TABLE_SIZE);
 settingsBuffer[IDX_SETTINGS_HEADER_TABLE_SIZE]=

src/node_http2.cc

@@ -228,6 +228,16 @@ size_t Http2Settings::Init(
 HTTP2_SETTINGS(V)
 #undef V
 
+uint32_t numAddSettings = buffer[IDX_SETTINGS_COUNT + 1];
+if (numAddSettings > 0){
+uint32_t offset = IDX_SETTINGS_COUNT + 1 + 1;
+for (uint32_t i = 0; i < numAddSettings; i++){
+uint32_t key = buffer[offset + i * 2 + 0];
+uint32_t val = buffer[offset + i * 2 + 1];
+ entries[count++] = nghttp2_settings_entry{(int32_t)key, val};
+ }
+ }
+
 return count;
 }
 #undef GRABSETTING
@@ -262,7 +272,7 @@ Local<Value> Http2Settings::Pack(){
 }
 
 Local<Value> Http2Settings::Pack(Http2State* state){
- nghttp2_settings_entry entries[IDX_SETTINGS_COUNT];
+ nghttp2_settings_entry entries[IDX_SETTINGS_COUNT + MAX_ADDITIONAL_SETTINGS];
 size_t count = Init(state, entries);
 returnPack(state->env(), count, entries);
 }
@@ -298,6 +308,8 @@ void Http2Settings::Update(Http2Session* session, get_setting fn){
 fn(session->session(), NGHTTP2_SETTINGS_ ## name);
 HTTP2_SETTINGS(V)
 #undef V
+ buffer[IDX_SETTINGS_COUNT + 1] =
+0; // no additional settings are coming, clear them
 }
 
 // Initializes the shared TypedArray with the default settings values.
@@ -314,6 +326,7 @@ void Http2Settings::RefreshDefaults(Http2State* http2_state){
 #undef V
 
  buffer[IDX_SETTINGS_COUNT] = flags;
+ buffer[IDX_SETTINGS_COUNT + 1] = 0; // no additional settings
 }
 
 

src/node_http2.h

@@ -1035,7 +1035,7 @@ class Http2Settings : public AsyncWrap{
  v8::Global<v8::Function> callback_;
 uint64_t startTime_;
 size_t count_ = 0;
- nghttp2_settings_entry entries_[IDX_SETTINGS_COUNT];
+ nghttp2_settings_entry entries_[IDX_SETTINGS_COUNT + MAX_ADDITIONAL_SETTINGS];
 };
 
 classOrigins{

src/node_http2_state.h

@@ -21,6 +21,9 @@ namespace http2{
  IDX_SETTINGS_COUNT
  };
 
+// number of max additional settings, thus settings not implemented by nghttp2
+constsize_t MAX_ADDITIONAL_SETTINGS = 10;
+
 enum Http2SessionStateIndex{
  IDX_SESSION_STATE_EFFECTIVE_LOCAL_WINDOW_SIZE,
  IDX_SESSION_STATE_EFFECTIVE_RECV_DATA_LENGTH,
@@ -108,10 +111,11 @@ class Http2State : public BaseObject{
  offsetof(http2_state_internal, options_buffer),
  IDX_OPTIONS_FLAGS + 1,
  root_buffer),
- settings_buffer(realm->isolate(),
- offsetof(http2_state_internal, settings_buffer),
- IDX_SETTINGS_COUNT + 1,
- root_buffer){}
+ settings_buffer(
+ realm->isolate(),
+ offsetof(http2_state_internal, settings_buffer),
+ IDX_SETTINGS_COUNT + 1 + 1 + 2 * MAX_ADDITIONAL_SETTINGS,
+ root_buffer){}
 
  AliasedUint8Array root_buffer;
  AliasedFloat64Array session_state_buffer;
@@ -135,7 +139,12 @@ class Http2State : public BaseObject{
 double stream_stats_buffer[IDX_STREAM_STATS_COUNT];
 double session_stats_buffer[IDX_SESSION_STATS_COUNT];
 uint32_t options_buffer[IDX_OPTIONS_FLAGS + 1];
-uint32_t settings_buffer[IDX_SETTINGS_COUNT + 1];
+// first + 1: number of actual nghttp2 supported settings
+// second + 1: number of additional settings not suppoted by nghttp2
+// 2 * MAX_ADDITIONAL_SETTINGS: settings id and value for each
+// additional setting
+uint32_t settings_buffer[IDX_SETTINGS_COUNT + 1 + 1 +
+2 * MAX_ADDITIONAL_SETTINGS];
  };
 };
 

test/parallel/test-http2-getpackedsettings.js

@@ -29,6 +29,7 @@ assert.deepStrictEqual(val, check);
 ['maxHeaderListSize',2**32-1],
 ['maxHeaderSize',0],
 ['maxHeaderSize',2**32-1],
+['customSettings',{'9999': 301}],
 ].forEach((i)=>{
 // Valid options should not throw.
 http2.getPackedSettings({[i[0]]: i[1]});
@@ -93,6 +94,7 @@ http2.getPackedSettings({enablePush: false });
 0x00,0x05,0x00,0x00,0x4e,0x20,
 0x00,0x06,0x00,0x00,0x00,0x64,
 0x00,0x08,0x00,0x00,0x00,0x00,
+0x27,0x0F,0x00,0x00,0x01,0x2d,
 ]);
 
 constpacked=http2.getPackedSettings({
@@ -104,12 +106,90 @@ http2.getPackedSettings({enablePush: false });
 maxHeaderSize: 100,
 enablePush: true,
 enableConnectProtocol: false,
-foo: 'ignored'
+foo: 'ignored',
+customSettings: {'9999': 301}
 });
-assert.strictEqual(packed.length,42);
+assert.strictEqual(packed.length,48);
 assert.deepStrictEqual(packed,check);
 }
 
+// Check if multiple custom settings can be set
+{
+constcheck=Buffer.from([
+0x00,0x01,0x00,0x00,0x00,0x64,
+0x00,0x02,0x00,0x00,0x00,0x01,
+0x00,0x03,0x00,0x00,0x00,0xc8,
+0x00,0x04,0x00,0x00,0x00,0x64,
+0x00,0x05,0x00,0x00,0x4e,0x20,
+0x00,0x06,0x00,0x00,0x00,0x64,
+0x00,0x08,0x00,0x00,0x00,0x00,
+0x03,0xf3,0x00,0x00,0x07,0x9F,
+0x0a,0x2e,0x00,0x00,0x00,0x58,
+]);
+
+constpacked=http2.getPackedSettings({
+headerTableSize: 100,
+initialWindowSize: 100,
+maxFrameSize: 20000,
+maxConcurrentStreams: 200,
+maxHeaderListSize: 100,
+maxHeaderSize: 100,
+enablePush: true,
+enableConnectProtocol: false,
+customSettings: {'2606': 88,'1011': 1951}
+});
+assert.strictEqual(packed.length,54);
+assert.deepStrictEqual(packed,check);
+}
+
+{
+// Check if wrong custom settings cause an error
+
+assert.throws(()=>{
+http2.getPackedSettings({
+customSettings: {'-1': 659685}
+});
+},{
+code: 'ERR_HTTP2_INVALID_SETTING_VALUE',
+name: 'RangeError'
+});
+
+assert.throws(()=>{
+http2.getPackedSettings({
+customSettings: {'10': 34577577777}
+});
+},{
+code: 'ERR_HTTP2_INVALID_SETTING_VALUE',
+name: 'RangeError'
+});
+
+assert.throws(()=>{
+http2.getPackedSettings({
+customSettings: {'notvalid': -777}
+});
+},{
+code: 'ERR_HTTP2_INVALID_SETTING_VALUE',
+name: 'RangeError'
+});
+
+assert.throws(()=>{
+http2.getPackedSettings({
+customSettings: {'11': 11,'12': 12,'13': 13,'14': 14,'15': 15,'16': 16,
+'17': 17,'18': 18,'19': 19,'20': 20,'21': 21}
+});
+},{
+code: 'ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS'
+});
+assert.throws(()=>{
+http2.getPackedSettings({
+customSettings: {'11': 11,'12': 12,'13': 13,'14': 14,'15': 15,'16': 16,
+'17': 17,'18': 18,'19': 19,'20': 20,'21': 21,'22': 22}
+});
+},{
+code: 'ERR_HTTP2_TOO_MANY_CUSTOM_SETTINGS'
+});
+}
+
 // Check for not passing settings.
 {
 constpacked=http2.getPackedSettings();
@@ -124,7 +204,8 @@ http2.getPackedSettings({enablePush: false });
 0x00,0x04,0x00,0x00,0x00,0x64,
 0x00,0x06,0x00,0x00,0x00,0x64,
 0x00,0x02,0x00,0x00,0x00,0x01,
-0x00,0x08,0x00,0x00,0x00,0x00]);
+0x00,0x08,0x00,0x00,0x00,0x00,
+0x27,0x0F,0x00,0x00,0x01,0x2d]);
 
 [1,true,'',[],{},NaN].forEach((input)=>{
 assert.throws(()=>{
@@ -157,6 +238,7 @@ http2.getPackedSettings({enablePush: false });
 assert.strictEqual(settings.maxHeaderSize,100);
 assert.strictEqual(settings.enablePush,true);
 assert.strictEqual(settings.enableConnectProtocol,false);
+assert.deepStrictEqual(settings.customSettings,{'9999': 301});
 }
 
 {

test/parallel/test-http2-update-settings.js

@@ -19,7 +19,8 @@ testUpdateSettingsWith({
 'maxHeaderListSize': 1,
 'maxFrameSize': 16385,
 'enablePush': false,
-'enableConnectProtocol': true
+'enableConnectProtocol': true,
+'customSettings': {'9999': 301}
 }
 });
 testUpdateSettingsWith({