From b570e123128f3fafa583bae186fd61429dcb49a7 Mon Sep 17 00:00:00 2001
From: Guus Sliepen <guus@meshlink.io>
Date: Wed, 10 Dec 2014 11:11:09 +0100
Subject: [PATCH] Handle retransmissions in CLOSE_WAIT, CLOSING and LAST_ACK
states.
---
utcp.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/utcp.c b/utcp.c
index f062319..e8755ed 100644
--- a/utcp.c
+++ b/utcp.c
@@ -465,11 +465,8 @@ static void retransmit(struct utcp_connection *c) {
pkt->hdr.dst = c->dst;
switch(c->state) {
- case LISTEN:
- // TODO: this should not happen
- break;
-
case SYN_SENT:
+ // Send our SYN again
pkt->hdr.seq = c->snd.iss;
pkt->hdr.ack = 0;
pkt->hdr.wnd = c->rcv.wnd;
@@ -479,6 +476,7 @@ static void retransmit(struct utcp_connection *c) {
break;
case SYN_RECEIVED:
+ // Send SYNACK again
pkt->hdr.seq = c->snd.nxt;
pkt->hdr.ack = c->rcv.nxt;
pkt->hdr.ctl = SYN | ACK;
@@ -488,28 +486,34 @@ static void retransmit(struct utcp_connection *c) {
case ESTABLISHED:
case FIN_WAIT_1:
+ case CLOSE_WAIT:
+ case CLOSING:
+ case LAST_ACK:
+ // Send unacked data again.
pkt->hdr.seq = c->snd.una;
pkt->hdr.ack = c->rcv.nxt;
pkt->hdr.ctl = ACK;
- uint32_t len = seqdiff(c->snd.nxt, c->snd.una);
- if(c->state == FIN_WAIT_1)
- len--;
+ uint32_t len = seqdiff(c->snd.last, c->snd.una);
if(len > utcp->mtu)
len = utcp->mtu;
- else {
- if(c->state == FIN_WAIT_1)
- pkt->hdr.ctl |= FIN;
+ if(fin_wanted(c, c->snd.una + len)) {
+ len--;
+ pkt->hdr.ctl |= FIN;
}
buffer_copy(&c->sndbuf, pkt->data, 0, len);
print_packet(c->utcp, "rtrx", pkt, sizeof pkt->hdr + len);
utcp->send(utcp, pkt, sizeof pkt->hdr + len);
break;
- default:
- // TODO: implement
+ case CLOSED:
+ case LISTEN:
+ case TIME_WAIT:
+ case FIN_WAIT_2:
+ // We shouldn't need to retransmit anything in this state.
#ifdef UTCP_DEBUG
abort();
#endif
+ timerclear(&c->rtrx_timeout);
break;
}
--
2.39.5