mismatch value for datapath_epoll CXPLAT_DATAPATH_FEATURE_SEND_SEGMENTATION · microsoft/msquic#5215

(3 评论) (0 反应) (0 负责人)C (671 fork)github user discovery

Bug: PlatformTriagedexternalhelp wanted

仓库指标

Star: (4,712 star)
PR 合并指标: (PR 指标待抓取)

描述

Describe the bug

The code snippet shows two different initialization approaches for SendDataSize and SendIoVecCount based on whether send segmentation is supported: datapath_epoll.c 311-320

if (Datapath->Features & CXPLAT_DATAPATH_FEATURE_SEND_SEGMENTATION) {
        Datapath->SendDataSize = sizeof(CXPLAT_SEND_DATA);
        Datapath->SendIoVecCount = 1;
    } else {
        const uint32_t SendDataSize =
            sizeof(CXPLAT_SEND_DATA) + (CXPLAT_MAX_IO_BATCH_SIZE - 1) * sizeof(struct iovec);
        Datapath->SendDataSize = SendDataSize;
        Datapath->SendIoVecCount = CXPLAT_MAX_IO_BATCH_SIZE;
    }

These parameters are initialized by DataPathInitialize. However, when CxPlatSendDataSend encounters an EIO error, the code disables the segmentation feature but doesn't reinitialize SendDataSize and SendIoVecCount:

if (Status == EIO &&
                SocketContext->Binding->Datapath->Features & CXPLAT_DATAPATH_FEATURE_SEND_SEGMENTATION) {
                //
                // EIO generally indicates the GSO isn't supported by the NIC,
                // so disable segmentation on the datapath globally.
                //
                QuicTraceEvent(
                    LibraryError,
                    "[ lib] ERROR, %s.",
                    "Disabling segmentation support globally");
                SocketContext->Binding->Datapath->Features &=
                    ~CXPLAT_DATAPATH_FEATURE_SEND_SEGMENTATION;
            }

Affected OS

Windows
Linux
macOS
Other (specify below)

Additional OS information

No response

MsQuic version

main

Steps taken to reproduce bug

find by code reading.

Expected behavior

should have correct value

Actual outcome

find by code reading

Additional details