[lwip-devel] One question about codes of tcp_input in tcp_in.c
From:
mud dog
Subject:
[lwip-devel] One question about codes of tcp_input in tcp_in.c
Date:
Sun, 23 Oct 2005 14:43:47 +0800
Hi all:
When reading the tcp codes of lwIP, I made a question.
After calling the tcp_process in tcp_input, we determine
the return status and flags of tcp_process, when err != ERR_ABRT
and recv_flags' TF_RESET,TF_CLOSED is not set, call the tcp_output(pcb)
to send what? why do this?
err = tcp_process(pcb); if (err != ERR_ABRT) { if (recv_flags & TF_RESET) { ................. } else if (recv_flags & TF_CLOSED) { ............... } else { err = ERR_OK; ............ if (err == ERR_OK) { tcp_output(pcb); ~~~~~~~~~~~~why this line? to send what? } } }