debug("%p new state: %s\n", c->utcp, strstate[state]);
}
+static bool fin_wanted(struct utcp_connection *c, uint32_t seq) {
+ if(seq != c->snd.last)
+ return false;
+ switch(c->state) {
+ case FIN_WAIT_1:
+ case CLOSING:
+ case LAST_ACK:
+ return true;
+ default:
+ return false;
+ }
+}
+
static inline void list_connections(struct utcp *utcp) {
debug("%p has %d connections:\n", utcp, utcp->nconnections);
for(int i = 0; i < utcp->nconnections; i++)
c->snd.nxt += seglen;
left -= seglen;
- if(c->state != ESTABLISHED && !left && seglen) {
- switch(c->state) {
- case FIN_WAIT_1:
- case CLOSING:
- seglen--;
- pkt->hdr.ctl |= FIN;
- break;
- default:
- break;
- }
+ if(seglen && fin_wanted(c, c->snd.nxt)) {
+ seglen--;
+ pkt->hdr.ctl |= FIN;
}
print_packet(c->utcp, "send", pkt, sizeof pkt->hdr + seglen);
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;
break;
case SYN_RECEIVED:
+ // Send SYNACK again
pkt->hdr.seq = c->snd.nxt;
pkt->hdr.ack = c->rcv.nxt;
pkt->hdr.ctl = SYN | ACK;
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);
- fprintf(stderr, "retransmit %u %u %u\n", pkt->hdr.seq, pkt->hdr.ack, len);
- 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;
}
free(pkt);
case TIME_WAIT:
break;
default:
+#ifdef UTCP_DEBUG
abort();
+#endif
+ break;
}
// 1b. Drop packets with a sequence number not in our receive window.
set_state(c, CLOSED);
return 0;
default:
+#ifdef UTCP_DEBUG
abort();
+#endif
+ break;
}
}
c->dupack++;
if(c->dupack == 3) {
debug("Triplicate ACK\n");
- fprintf(stderr, "Triplicate ACK\n");
//TODO: Resend one packet and go to fast recovery mode. See RFC 6582.
//We do a very simple variant here; reset the nxt pointer to the last acknowledged packet from the peer.
//This will cause us to start retransmitting, but at the same speed as the incoming ACKs arrive,
// Ehm, no. We should never receive a second SYN.
goto reset;
default:
+#ifdef UTCP_DEBUG
abort();
+#endif
+ return 0;
}
// SYN counts as one sequence number
case SYN_SENT:
case SYN_RECEIVED:
// This should never happen.
+#ifdef UTCP_DEBUG
abort();
+#endif
+ return 0;
case ESTABLISHED:
case FIN_WAIT_1:
case FIN_WAIT_2:
// Ehm no, We should never receive more data after a FIN.
goto reset;
default:
+#ifdef UTCP_DEBUG
abort();
+#endif
+ return 0;
}
ssize_t rxd;
case SYN_SENT:
case SYN_RECEIVED:
// This should never happen.
+#ifdef UTCP_DEBUG
abort();
+#endif
+ break;
case ESTABLISHED:
set_state(c, CLOSE_WAIT);
break;
// Ehm, no. We should never receive a second FIN.
goto reset;
default:
+#ifdef UTCP_DEBUG
abort();
+#endif
+ break;
}
// FIN counts as one sequence number
}
int utcp_shutdown(struct utcp_connection *c, int dir) {
- debug("%p shutdown %d\n", c ? c->utcp : NULL, dir);
+ debug("%p shutdown %d at %u\n", c ? c->utcp : NULL, dir, c->snd.last);
if(!c) {
errno = EFAULT;
return -1;
}
// TODO: handle dir
+ // TODO: check that repeated calls with the same parameters should have no effect
switch(c->state) {
case CLOSED:
}
uint16_t utcp_get_mtu(struct utcp *utcp) {
- return utcp->mtu;
+ return utcp ? utcp->mtu : 0;
}
void utcp_set_mtu(struct utcp *utcp, uint16_t mtu) {
// TODO: handle overhead of the header
- utcp->mtu = mtu;
+ if(utcp)
+ utcp->mtu = mtu;
}
int utcp_get_user_timeout(struct utcp *u) {
- return u->timeout;
+ return u ? u->timeout : 0;
}
void utcp_set_user_timeout(struct utcp *u, int timeout) {
- u->timeout = timeout;
+ if(u)
+ u->timeout = timeout;
}
size_t utcp_get_sndbuf(struct utcp_connection *c) {
- return c->sndbuf.maxsize;
+ return c ? c->sndbuf.maxsize : 0;
}
size_t utcp_get_sndbuf_free(struct utcp_connection *c) {
- return buffer_free(&c->sndbuf);
+ if(c && (c->state == ESTABLISHED || c->state == CLOSE_WAIT))
+ return buffer_free(&c->sndbuf);
+ else
+ return 0;
}
void utcp_set_sndbuf(struct utcp_connection *c, size_t size) {
+ if(!c)
+ return;
c->sndbuf.maxsize = size;
if(c->sndbuf.maxsize != size)
c->sndbuf.maxsize = -1;
}
bool utcp_get_nodelay(struct utcp_connection *c) {
- return c->nodelay;
+ return c ? c->nodelay : false;
}
void utcp_set_nodelay(struct utcp_connection *c, bool nodelay) {
- c->nodelay = nodelay;
+ if(c)
+ c->nodelay = nodelay;
}
bool utcp_get_keepalive(struct utcp_connection *c) {
- return c->keepalive;
+ return c ? c->keepalive : false;
}
void utcp_set_keepalive(struct utcp_connection *c, bool keepalive) {
- c->keepalive = keepalive;
+ if(c)
+ c->keepalive = keepalive;
}
size_t utcp_get_outq(struct utcp_connection *c) {
- return seqdiff(c->snd.nxt, c->snd.una);
+ return c ? seqdiff(c->snd.nxt, c->snd.una) : 0;
}
void utcp_set_recv_cb(struct utcp_connection *c, utcp_recv_t recv) {
- c->recv = recv;
+ if(c)
+ c->recv = recv;
}
void utcp_set_poll_cb(struct utcp_connection *c, utcp_poll_t poll) {
- c->poll = poll;
+ if(c)
+ c->poll = poll;
}
projects / utcp / blobdiff