Quality RTOS & Embedded Software

Delta Over-the-Air Updates
December 2021 Releases:
Extended Maintenance Plan (EMP):
FreeRTOS 202111.00 Release:
FreeRTOS LTS libraries:


[FreeRTOS+TCP API Reference]


Note: this hook needs to be defined only when ipconfigPROCESS_CUSTOM_ETHERNET_FRAMES is set to 1 in the FreeRTOSIPConfig.h file.

eFrameProcessingResult_t eApplicationProcessCustomFrameHook( NetworkBufferDescriptor_t * const pxNetworkBuffer );

eApplicationProcessCustomFrameHook is an application defined hook (or *callback*) function that is called by the FreeRTOS+TCP stack when the stack receives a frame which is not handled by the stack which is anything except an ARP frame or an IP packet.

Callback functions are implemented by the application writer, but called by the TCP/IP stack. The prototype of the callback function must exactly match the prototype above (including the function name). The code in an application hook should not call FreeRTOS+TCP API's that are blocking. That could easily lead to a dead-lock.

When an application hook executes, it borrows the task priority and the stack of the IP-task. Therefore, we recommend that you keep application hooks short--it may want to wakeup some application task which will do further processing.

pxNetworkBuffer   The network buffer containing the unsupported frame.

Return value:

The returned value must be of the type eFrameProcessingResult_t. If the frame is to be released then eReleaseBuffer should be returned and the network stack will take care of clean-up. If anything else is returned, then the user/application must release the network buffer by calling vReleaseNetworkBufferAndDescriptor().

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