This is an old revision of the document!
==== Several TCP fixes ==== === Separating the xfer interface closing routines from tcp_close === The original Receive flow of TCP stack pass the data to upper layer while the TCP state transition and response still in progress. But when upper layer received some specific data, it might send data through the current TCP connection, or close the current TCP connection. This issue makes the TCP state hard to maintain. After we separating the xfer interface closing routines from tcp_close, we have the opportunity to handle the TCP state, and shutdown the deliver interface at different but more suitable place. While receiving data, we deliver the data to upper layer after we FULLY updated/handled the TCP state. So that any actions that the upper layer might do to the TCP stack would be at safer timing. === Distinguish passive and active close with proper actions === The original design of TCP stack dose not distinguish passive and active close, support is to make close action more compatible with ''RFC 793'' and having the ability to take the advantage of release all resources when passive closing. === Fix possible misjudged SYN/FIN ACKed status === gPXE did not check the ACK number while receiving a response from remote server with ACK flag set. gPXE assumes the remote server ACKed the SYN/FIN sent by gPXE if *ANY* received a packet from remote server with ACK flag set. The error might occur when the packet is out-of-order. === Update the rule for ignore xmit while timer was fired == If the retransmit timer was fired due to ACK to remote host and without data, we should send the latest ACK(force_send) update to remote host instead of ignoring it. ==== gPXE scheduling and program flow documentation ==== Doing a note.
