Support setting flow control limits for individual stream types (#3948)

Author: rzikm

docs/Settings.md

@@ -31,7 +31,10 @@ The following settings are available via registry as well as via [QUIC_SETTINGS]
 | Idle Timeout                       | uint64_t   | IdleTimeoutMs               |            30,000 | How long a connection can go idle before it is silently shut down. 0 to disable timeout                                       |
 | Max TLS Send Buffer (Client)       | uint32_t   | TlsClientMaxSendBuffer      |             4,096 | How much client TLS data to buffer.                                                                                           |
 | Max TLS Send Buffer (Server)       | uint32_t   | TlsServerMaxSendBuffer      |             8,192 | How much server TLS data to buffer.                                                                                           |
-| Stream Receive Window              | uint32_t   | StreamRecvWindowDefault     |            32,768 | Initial stream receive window size.                                                                                           |
+| Stream Receive Window              | uint32_t   | StreamRecvWindowDefault     |            65,536 | Initial stream receive window size for all stream types.                                                                      |
+| Stream Receive Window (Bidirectional, locally created) | uint32_t   | StreamRecvWindowBidiLocalDefault |            - | If set, overrides stream receive window size for locally initiated bidirectional streams.                                     |
+| Stream Receive Window (Bidirectional, remotely created) | uint32_t   | StreamRecvWindowBidiRemoteDefault |            - | If set, overrides stream receive window size for remote initiated bidirectional streams.                                     |
+| Stream Receive Window (Unidirectional) | uint32_t   | StreamRecvWindowUnidiDefault |            - | If set, overrides stream receive window size for remote initiated unidirectional streams.                                     |
 | Stream Receive Buffer              | uint32_t   | StreamRecvBufferDefault     |             4,096 | Stream initial buffer size.                                                                                                   |
 | Flow Control Window                | uint32_t   | ConnFlowControlWindow       |        16,777,216 | Connection-wide flow control window.                                                                                          |
 | Max Stateless Operations           | uint32_t   | MaxStatelessOperations      |                16 | The maximum number of stateless operations that may be queued on a worker at any one time.                                    |

docs/api/QUIC_SETTINGS.md

@@ -45,7 +45,18 @@ typedef struct QUIC_SETTINGS {
             uint64_t DestCidUpdateIdleTimeoutMs             : 1;
             uint64_t GreaseQuicBitEnabled                   : 1;
             uint64_t EcnEnabled                             : 1;
-            uint64_t RESERVED                               : 30;
+            uint64_t HyStartEnabled                         : 1;
+            uint64_t StreamRecvWindowBidiLocalDefault       : 1;
+            uint64_t StreamRecvWindowBidiRemoteDefault      : 1;
+            uint64_t StreamRecvWindowUnidiDefault           : 1;
+#ifdef QUIC_API_ENABLE_PREVIEW_FEATURES
+            uint64_t EncryptionOffloadAllowed               : 1;
+            uint64_t ReliableResetEnabled                   : 1;
+            uint64_t OneWayDelayEnabled                     : 1;
+            uint64_t RESERVED                               : 23;
+#else
+            uint64_t RESERVED                               : 26;
+#endif
         } IsSet;
     };
 
@@ -83,6 +94,23 @@ typedef struct QUIC_SETTINGS {
     uint8_t MaxOperationsPerDrain;
     uint8_t MtuDiscoveryMissingProbeCount;
     uint32_t DestCidUpdateIdleTimeoutMs;
+    union {
+        uint64_t Flags;
+        struct {
+            uint64_t HyStartEnabled            : 1;
+#ifdef QUIC_API_ENABLE_PREVIEW_FEATURES
+            uint64_t EncryptionOffloadAllowed  : 1;
+            uint64_t ReliableResetEnabled      : 1;
+            uint64_t OneWayDelayEnabled        : 1;
+            uint64_t ReservedFlags             : 60;
+#else
+            uint64_t ReservedFlags             : 63;
+#endif
+        };
+    };
+    uint32_t StreamRecvWindowBidiLocalDefault;
+    uint32_t StreamRecvWindowBidiRemoteDefault;
+    uint32_t StreamRecvWindowUnidiDefault;
 
 } QUIC_SETTINGS;
 ```
@@ -125,9 +153,9 @@ How much server TLS data to buffer.  If the application expects very large serve
 
 `StreamRecvWindowDefault`
 
-Initial stream receive window size.
+Initial stream receive flow control window size. This applies to all stream types. Limits for specific stream types can be set using `StreamRecvWindowBidirLocalDefault`, `StreamRecvWindowBidirRemoteDefault` and `StreamRecvWindowUnidirDefault`. The value must be a power of 2.
 
-**Default value:** 32,768
+**Default value:** 65,536
 
 `StreamRecvBufferDefault`
 
@@ -303,6 +331,24 @@ Enable sender-side ECN support. The connection will validate and react to ECN fe
 
 **Default value:** 0 (`FALSE`)
 
+`StreamRecvWindowBidirLocalDefault`
+
+Initial stream receive flow control window size for locally initiated bidirectional streams. If set, this value overwrites the `StreamRecvWindowDefault`.
+
+**Default value:** 0 (no overwrite)
+
+`StreamRecvWindowBidirRemoteDefault`
+
+Initial stream receive flow control window size for remotely initiated bidirectional streams. If set, this value overwrites the `StreamRecvWindowDefault`.
+
+**Default value:** 0 (no overwrite)
+
+`StreamRecvWindowUnidiDefault`
+
+Initial stream receive flow control window size for remotely initiated unidirectional streams. If set, this value overwrites the `StreamRecvWindowDefault`.
+
+**Default value:** 0 (no overwrite)
+
 # Remarks
 
 When setting new values for the settings, the app must set the corresponding `.IsSet.*` parameter for each actual parameter that is being set or updated. For example:

src/core/connection.c

@@ -2198,9 +2198,9 @@ QuicConnRecvResumptionTicket(
         //
         if (ResumedTP.ActiveConnectionIdLimit > QUIC_ACTIVE_CONNECTION_ID_LIMIT ||
             ResumedTP.InitialMaxData > Connection->Send.MaxData ||
-            ResumedTP.InitialMaxStreamDataBidiLocal > Connection->Settings.StreamRecvWindowDefault ||
-            ResumedTP.InitialMaxStreamDataBidiRemote > Connection->Settings.StreamRecvWindowDefault ||
-            ResumedTP.InitialMaxStreamDataUni > Connection->Settings.StreamRecvWindowDefault ||
+            ResumedTP.InitialMaxStreamDataBidiLocal > Connection->Settings.StreamRecvWindowBidiLocalDefault ||
+            ResumedTP.InitialMaxStreamDataBidiRemote > Connection->Settings.StreamRecvWindowBidiRemoteDefault ||
+            ResumedTP.InitialMaxStreamDataUni > Connection->Settings.StreamRecvWindowUnidiDefault ||
             ResumedTP.InitialMaxUniStreams > Connection->Streams.Types[STREAM_ID_FLAG_IS_CLIENT | STREAM_ID_FLAG_IS_UNI_DIR].MaxTotalStreamCount ||
             ResumedTP.InitialMaxBidiStreams > Connection->Streams.Types[STREAM_ID_FLAG_IS_CLIENT | STREAM_ID_FLAG_IS_BI_DIR].MaxTotalStreamCount) {
             //
@@ -2344,9 +2344,9 @@ QuicConnGenerateLocalTransportParameters(
             Link);
 
     LocalTP->InitialMaxData = Connection->Send.MaxData;
-    LocalTP->InitialMaxStreamDataBidiLocal = Connection->Settings.StreamRecvWindowDefault;
-    LocalTP->InitialMaxStreamDataBidiRemote = Connection->Settings.StreamRecvWindowDefault;
-    LocalTP->InitialMaxStreamDataUni = Connection->Settings.StreamRecvWindowDefault;
+    LocalTP->InitialMaxStreamDataBidiLocal = Connection->Settings.StreamRecvWindowBidiLocalDefault;
+    LocalTP->InitialMaxStreamDataBidiRemote = Connection->Settings.StreamRecvWindowBidiRemoteDefault;
+    LocalTP->InitialMaxStreamDataUni = Connection->Settings.StreamRecvWindowUnidiDefault;
     LocalTP->MaxUdpPayloadSize =
         MaxUdpPayloadSizeFromMTU(
             CxPlatSocketGetLocalMtu(

src/core/quicdef.h

@@ -652,6 +652,9 @@ CXPLAT_STATIC_ASSERT(
 #define QUIC_SETTING_MAX_TLS_CLIENT_SEND_BUFFER     "TlsClientMaxSendBuffer"
 #define QUIC_SETTING_MAX_TLS_SERVER_SEND_BUFFER     "TlsServerMaxSendBuffer"
 #define QUIC_SETTING_STREAM_FC_WINDOW_SIZE          "StreamRecvWindowDefault"
+#define QUIC_SETTING_STREAM_FC_BIDI_LOCAL_WINDOW_SIZE "StreamRecvWindowBidiLocalDefault"
+#define QUIC_SETTING_STREAM_FC_BIDI_REMOTE_WINDOW_SIZE "StreamRecvWindowBidiRemoteDefault"
+#define QUIC_SETTING_STREAM_FC_UNIDI_WINDOW_SIZE    "StreamRecvWindowUnidiDefault"
 #define QUIC_SETTING_STREAM_RECV_BUFFER_SIZE        "StreamRecvBufferDefault"
 #define QUIC_SETTING_CONN_FLOW_CONTROL_WINDOW       "ConnFlowControlWindow"
 

src/core/settings.c

@@ -96,6 +96,15 @@ QuicSettingsSetDefault(
     if (!Settings->IsSet.StreamRecvWindowDefault) {
         Settings->StreamRecvWindowDefault = QUIC_DEFAULT_STREAM_FC_WINDOW_SIZE;
     }
+    if (!Settings->IsSet.StreamRecvWindowBidiLocalDefault) {
+        Settings->StreamRecvWindowBidiLocalDefault = QUIC_DEFAULT_STREAM_FC_WINDOW_SIZE;
+    }
+    if (!Settings->IsSet.StreamRecvWindowBidiRemoteDefault) {
+        Settings->StreamRecvWindowBidiRemoteDefault = QUIC_DEFAULT_STREAM_FC_WINDOW_SIZE;
+    }
+    if (!Settings->IsSet.StreamRecvWindowUnidiDefault) {
+        Settings->StreamRecvWindowUnidiDefault = QUIC_DEFAULT_STREAM_FC_WINDOW_SIZE;
+    }
     if (!Settings->IsSet.StreamRecvBufferDefault) {
         Settings->StreamRecvBufferDefault = QUIC_DEFAULT_STREAM_RECV_BUFFER_SIZE;
     }
@@ -231,6 +240,15 @@ QuicSettingsCopy(
     if (!Destination->IsSet.StreamRecvWindowDefault) {
         Destination->StreamRecvWindowDefault = Source->StreamRecvWindowDefault;
     }
+    if (!Destination->IsSet.StreamRecvWindowBidiLocalDefault) {
+        Destination->StreamRecvWindowBidiLocalDefault = Source->StreamRecvWindowBidiLocalDefault;
+    }
+    if (!Destination->IsSet.StreamRecvWindowBidiRemoteDefault) {
+        Destination->StreamRecvWindowBidiRemoteDefault = Source->StreamRecvWindowBidiRemoteDefault;
+    }
+    if (!Destination->IsSet.StreamRecvWindowUnidiDefault) {
+        Destination->StreamRecvWindowUnidiDefault = Source->StreamRecvWindowUnidiDefault;
+    }
     if (!Destination->IsSet.StreamRecvBufferDefault) {
         Destination->StreamRecvBufferDefault = Source->StreamRecvBufferDefault;
     }
@@ -496,6 +514,40 @@ QuicSettingApply(
         }
         Destination->StreamRecvWindowDefault = Source->StreamRecvWindowDefault;
         Destination->IsSet.StreamRecvWindowDefault = TRUE;
+
+        //
+        // Also set window size for individual stream types, they will be overwritten by a more specific settings if set
+        //
+        if (!Destination->IsSet.StreamRecvWindowBidiLocalDefault || OverWrite) {
+            Destination->StreamRecvWindowBidiLocalDefault = Source->StreamRecvWindowDefault;
+        }
+        if (!Destination->IsSet.StreamRecvWindowBidiRemoteDefault || OverWrite) {
+            Destination->StreamRecvWindowBidiRemoteDefault = Source->StreamRecvWindowDefault;
+        }
+        if (!Destination->IsSet.StreamRecvWindowUnidiDefault || OverWrite) {
+            Destination->StreamRecvWindowUnidiDefault = Source->StreamRecvWindowDefault;
+        }
+    }
+    if (Source->IsSet.StreamRecvWindowBidiLocalDefault && (!Destination->IsSet.StreamRecvWindowBidiLocalDefault || OverWrite)) {
+        if (Source->StreamRecvWindowBidiLocalDefault == 0 || (Source->StreamRecvWindowBidiLocalDefault & (Source->StreamRecvWindowBidiLocalDefault - 1)) != 0) {
+            return FALSE; // Must be power of 2
+        }
+        Destination->StreamRecvWindowBidiLocalDefault = Source->StreamRecvWindowBidiLocalDefault;
+        Destination->IsSet.StreamRecvWindowBidiLocalDefault = TRUE;
+    }
+    if (Source->IsSet.StreamRecvWindowBidiRemoteDefault && (!Destination->IsSet.StreamRecvWindowBidiRemoteDefault || OverWrite)) {
+        if (Source->StreamRecvWindowBidiRemoteDefault == 0 || (Source->StreamRecvWindowBidiRemoteDefault & (Source->StreamRecvWindowBidiRemoteDefault - 1)) != 0) {
+            return FALSE; // Must be power of 2
+        }
+        Destination->StreamRecvWindowBidiRemoteDefault = Source->StreamRecvWindowBidiRemoteDefault;
+        Destination->IsSet.StreamRecvWindowBidiRemoteDefault = TRUE;
+    }
+    if (Source->IsSet.StreamRecvWindowUnidiDefault && (!Destination->IsSet.StreamRecvWindowUnidiDefault || OverWrite)) {
+        if (Source->StreamRecvWindowUnidiDefault == 0 || (Source->StreamRecvWindowUnidiDefault & (Source->StreamRecvWindowUnidiDefault - 1)) != 0) {
+            return FALSE; // Must be power of 2
+        }
+        Destination->StreamRecvWindowUnidiDefault = Source->StreamRecvWindowUnidiDefault;
+        Destination->IsSet.StreamRecvWindowUnidiDefault = TRUE;
     }
     if (Source->IsSet.StreamRecvBufferDefault && (!Destination->IsSet.StreamRecvBufferDefault || OverWrite)) {
         if (Source->StreamRecvBufferDefault < QUIC_DEFAULT_STREAM_RECV_BUFFER_SIZE) {
@@ -911,6 +963,33 @@ QuicSettingsLoad(
             &ValueLen);
     }
 
+    if (!Settings->IsSet.StreamRecvWindowBidiLocalDefault) {
+        ValueLen = sizeof(Settings->StreamRecvWindowBidiLocalDefault);
+        CxPlatStorageReadValue(
+            Storage,
+            QUIC_SETTING_STREAM_FC_BIDI_LOCAL_WINDOW_SIZE,
+            (uint8_t*)&Settings->StreamRecvWindowBidiLocalDefault,
+            &ValueLen);
+    }
+
+    if (!Settings->IsSet.StreamRecvWindowBidiRemoteDefault) {
+        ValueLen = sizeof(Settings->StreamRecvWindowBidiRemoteDefault);
+        CxPlatStorageReadValue(
+            Storage,
+            QUIC_SETTING_STREAM_FC_BIDI_REMOTE_WINDOW_SIZE,
+            (uint8_t*)&Settings->StreamRecvWindowBidiRemoteDefault,
+            &ValueLen);
+    }
+
+    if (!Settings->IsSet.StreamRecvWindowUnidiDefault) {
+        ValueLen = sizeof(Settings->StreamRecvWindowUnidiDefault);
+        CxPlatStorageReadValue(
+            Storage,
+            QUIC_SETTING_STREAM_FC_UNIDI_WINDOW_SIZE,
+            (uint8_t*)&Settings->StreamRecvWindowUnidiDefault,
+            &ValueLen);
+    }
+
     if (!Settings->IsSet.StreamRecvBufferDefault) {
         ValueLen = sizeof(Settings->StreamRecvBufferDefault);
         CxPlatStorageReadValue(
@@ -1291,7 +1370,9 @@ QuicSettingsDump(
     QuicTraceLogVerbose(SettingDumpTlsClientMaxSendBuffer,  "[sett] TlsClientMaxSendBuffer = %u", Settings->TlsClientMaxSendBuffer);
     QuicTraceLogVerbose(SettingDumpTlsServerMaxSendBuffer,  "[sett] TlsServerMaxSendBuffer = %u", Settings->TlsServerMaxSendBuffer);
     QuicTraceLogVerbose(SettingDumpStreamRecvWindowDefault, "[sett] StreamRecvWindowDefault= %u", Settings->StreamRecvWindowDefault);
-    QuicTraceLogVerbose(SettingDumpStreamRecvBufferDefault, "[sett] StreamRecvBufferDefault= %u", Settings->StreamRecvBufferDefault);
+    QuicTraceLogVerbose(SettingDumpStreamRecvWindowBidiLocalDefault,  "[sett] StreamRecvWindowBidiLocalDefault  = %u", Settings->StreamRecvWindowBidiLocalDefault);
+    QuicTraceLogVerbose(SettingDumpStreamRecvWindowBidiRemoteDefault, "[sett] StreamRecvWindowBidiRemoteDefault = %u", Settings->StreamRecvWindowBidiRemoteDefault);
+    QuicTraceLogVerbose(SettingDumpStreamRecvWindowUnidiDefault,      "[sett] StreamRecvWindowUnidiDefault      = %u", Settings->StreamRecvWindowUnidiDefault);
     QuicTraceLogVerbose(SettingDumpConnFlowControlWindow,   "[sett] ConnFlowControlWindow  = %u", Settings->ConnFlowControlWindow);
     QuicTraceLogVerbose(SettingDumpMaxBytesPerKey,          "[sett] MaxBytesPerKey         = %llu", Settings->MaxBytesPerKey);
     QuicTraceLogVerbose(SettingDumpServerResumptionLevel,   "[sett] ServerResumptionLevel  = %hhu", Settings->ServerResumptionLevel);
@@ -1402,6 +1483,15 @@ QuicSettingsDumpNew(
     if (Settings->IsSet.StreamRecvWindowDefault) {
         QuicTraceLogVerbose(SettingDumpStreamRecvWindowDefault,     "[sett] StreamRecvWindowDefault= %u", Settings->StreamRecvWindowDefault);
     }
+    if (Settings->IsSet.StreamRecvWindowBidiLocalDefault) {
+        QuicTraceLogVerbose(SettingDumpStreamRecvWindowBidiLocalDefault, "[sett] StreamRecvWindowBidiLocalDefault  = %u", Settings->StreamRecvWindowBidiLocalDefault);
+    }
+    if (Settings->IsSet.StreamRecvWindowBidiRemoteDefault) {
+        QuicTraceLogVerbose(SettingDumpStreamRecvWindowBidiRemoteDefault, "[sett] StreamRecvWindowBidiRemoteDefault = %u", Settings->StreamRecvWindowBidiRemoteDefault);
+    }
+    if (Settings->IsSet.StreamRecvWindowUnidiDefault) {
+        QuicTraceLogVerbose(SettingDumpStreamRecvWindowUnidiDefault,  "[sett] StreamRecvWindowUnidiDefault      = %u", Settings->StreamRecvWindowUnidiDefault);
+    }
     if (Settings->IsSet.StreamRecvBufferDefault) {
         QuicTraceLogVerbose(SettingDumpStreamRecvBufferDefault,     "[sett] StreamRecvBufferDefault= %u", Settings->StreamRecvBufferDefault);
     }
@@ -1700,6 +1790,27 @@ QuicSettingsSettingsToInternal(
         SettingsSize,
         InternalSettings);
 
+    SETTING_COPY_TO_INTERNAL_SIZED(
+        StreamRecvWindowBidiLocalDefault,
+        QUIC_SETTINGS,
+        Settings,
+        SettingsSize,
+        InternalSettings);
+
+    SETTING_COPY_TO_INTERNAL_SIZED(
+        StreamRecvWindowBidiRemoteDefault,
+        QUIC_SETTINGS,
+        Settings,
+        SettingsSize,
+        InternalSettings);
+
+    SETTING_COPY_TO_INTERNAL_SIZED(
+        StreamRecvWindowUnidiDefault,
+        QUIC_SETTINGS,
+        Settings,
+        SettingsSize,
+        InternalSettings);
+
     return QUIC_STATUS_SUCCESS;
 }
 
@@ -1832,6 +1943,26 @@ QuicSettingsGetSettings(
         *SettingsLength,
         InternalSettings);
 
+    SETTING_COPY_FROM_INTERNAL_SIZED(
+        StreamRecvWindowBidiLocalDefault,
+        QUIC_SETTINGS,
+        Settings,
+        *SettingsLength,
+        InternalSettings);
+
+    SETTING_COPY_FROM_INTERNAL_SIZED(
+        StreamRecvWindowBidiRemoteDefault,
+        QUIC_SETTINGS,
+        Settings,
+        *SettingsLength,
+        InternalSettings);
+
+    SETTING_COPY_FROM_INTERNAL_SIZED(StreamRecvWindowUnidiDefault,
+        QUIC_SETTINGS,
+        Settings,
+        *SettingsLength,
+        InternalSettings);
+
     *SettingsLength = CXPLAT_MIN(*SettingsLength, sizeof(QUIC_SETTINGS));
 
     return QUIC_STATUS_SUCCESS;

src/core/settings.h

@@ -20,6 +20,9 @@ typedef struct QUIC_SETTINGS_INTERNAL {
             uint64_t TlsClientMaxSendBuffer                 : 1;
             uint64_t TlsServerMaxSendBuffer                 : 1;
             uint64_t StreamRecvWindowDefault                : 1;
+            uint64_t StreamRecvWindowBidiLocalDefault       : 1;
+            uint64_t StreamRecvWindowBidiRemoteDefault      : 1;
+            uint64_t StreamRecvWindowUnidiDefault           : 1;
             uint64_t StreamRecvBufferDefault                : 1;
             uint64_t ConnFlowControlWindow                  : 1;
             uint64_t MaxWorkerQueueDelayUs                  : 1;
@@ -57,7 +60,7 @@ typedef struct QUIC_SETTINGS_INTERNAL {
             uint64_t EncryptionOffloadAllowed               : 1;
             uint64_t ReliableResetEnabled                   : 1;
             uint64_t OneWayDelayEnabled                     : 1;
-            uint64_t RESERVED                               : 21;
+            uint64_t RESERVED                               : 18;
         } IsSet;
     };
 
@@ -69,6 +72,9 @@ typedef struct QUIC_SETTINGS_INTERNAL {
     uint32_t TlsClientMaxSendBuffer;
     uint32_t TlsServerMaxSendBuffer;
     uint32_t StreamRecvWindowDefault;
+    uint32_t StreamRecvWindowBidiLocalDefault;
+    uint32_t StreamRecvWindowBidiRemoteDefault;
+    uint32_t StreamRecvWindowUnidiDefault;
     uint32_t StreamRecvBufferDefault;
     uint32_t ConnFlowControlWindow;
     uint32_t MaxWorkerQueueDelayUs;

src/core/stream.c

@@ -114,11 +114,17 @@ QuicStreamInitialize(
         }
     }
 
+    const uint32_t FlowControlWindowSize = Stream->Flags.Unidirectional
+        ? Connection->Settings.StreamRecvWindowUnidiDefault
+        : OpenedRemotely
+            ? Connection->Settings.StreamRecvWindowBidiRemoteDefault
+            : Connection->Settings.StreamRecvWindowBidiLocalDefault;
+
     Status =
         QuicRecvBufferInitialize(
             &Stream->RecvBuffer,
             InitialRecvBufferLength,
-            Connection->Settings.StreamRecvWindowDefault,
+            FlowControlWindowSize,
             FALSE,
             PreallocatedRecvBuffer);
     if (QUIC_FAILED(Status)) {