lwIP pbuf_free() Function: Freeing Memory in the Network Stack

The code 'pbuf_free(p);' is used to free a pbuf structure in the lwIP network stack.

The 'pbuf_free()' function deallocates a pbuf structure and releases its associated memory. It takes a pointer to the pbuf structure as an argument and frees the memory.

Here, 'p' is a pointer to the pbuf structure that needs to be freed. After calling 'pbuf_free(p)', the memory occupied by the pbuf structure will be released and can be reused for other purposes.

It's important to note that 'pbuf_free()' only frees the pbuf structure itself, not the payload data it may be pointing to. If the payload data is dynamically allocated, it needs to be freed separately before calling 'pbuf_free()'.