X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=utcp.c;h=5d630694df96100f57e780f855a32cc63f7674bc;hb=f97e64bcb266c37a8eb24c3e8286272c02756e6e;hp=2ed32175dc0f98c9b2bc045f7a62fb43caeb5089;hpb=7baf55a28cf48163c007ee2ff56678371d78c990;p=utcp

diff --git a/utcp.c b/utcp.c
index 2ed3217..5d63069 100644
--- a/utcp.c
+++ b/utcp.c
@@ -415,13 +415,13 @@ static void update_rtt(struct utcp_connection *c, uint32_t rtt) {
 	if(!utcp->srtt) {
 		utcp->srtt = rtt;
 		utcp->rttvar = rtt / 2;
-		utcp->rto = rtt + max(2 * rtt, CLOCK_GRANULARITY);
 	} else {
 		utcp->rttvar = (utcp->rttvar * 3 + absdiff(utcp->srtt, rtt)) / 4;
 		utcp->srtt = (utcp->srtt * 7 + rtt) / 8;
-		utcp->rto = utcp->srtt + max(utcp->rttvar, CLOCK_GRANULARITY);
 	}
 
+	utcp->rto = utcp->srtt + max(4 * utcp->rttvar, CLOCK_GRANULARITY);
+
 	if(utcp->rto > MAX_RTO) {
 		utcp->rto = MAX_RTO;
 	}
@@ -629,6 +629,8 @@ ssize_t utcp_send(struct utcp_connection *c, const void *data, size_t len) {
 
 	if(is_reliable(c) || (c->state != SYN_SENT && c->state != SYN_RECEIVED)) {
 		len = buffer_put(&c->sndbuf, data, len);
+	} else {
+		return 0;
 	}
 
 	if(len <= 0) {
@@ -1055,6 +1057,7 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 				c->flags = UTCP_TCP;
 			}
 
+synack:
 			// Return SYN+ACK, go to SYN_RECEIVED state
 			c->snd.wnd = hdr.wnd;
 			c->rcv.irs = hdr.seq;
@@ -1313,8 +1316,10 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 
 		assert(data_acked >= 0);
 
+#ifndef NDEBUG
 		int32_t bufused = seqdiff(c->snd.last, c->snd.una);
 		assert(data_acked <= bufused);
+#endif
 
 		if(data_acked) {
 			buffer_get(&c->sndbuf, NULL, data_acked);
@@ -1346,7 +1351,7 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 		case CLOSING:
 			if(c->snd.una == c->snd.last) {
 				gettimeofday(&c->conn_timeout, NULL);
-				c->conn_timeout.tv_sec += 60;
+				c->conn_timeout.tv_sec += utcp->timeout;
 				set_state(c, TIME_WAIT);
 			}
 
@@ -1410,6 +1415,9 @@ skip_ack:
 			break;
 
 		case SYN_RECEIVED:
+			// This is a retransmit of a SYN, send back the SYNACK.
+			goto synack;
+
 		case ESTABLISHED:
 		case FIN_WAIT_1:
 		case FIN_WAIT_2:
@@ -1505,7 +1513,7 @@ skip_ack:
 
 		case FIN_WAIT_2:
 			gettimeofday(&c->conn_timeout, NULL);
-			c->conn_timeout.tv_sec += 60;
+			c->conn_timeout.tv_sec += utcp->timeout;
 			set_state(c, TIME_WAIT);
 			break;
 
@@ -1918,8 +1926,14 @@ void utcp_reset_timers(struct utcp *utcp) {
 			continue;
 		}
 
-		c->rtrx_timeout = now;
-		c->conn_timeout = then;
+		if(timerisset(&c->rtrx_timeout)) {
+			c->rtrx_timeout = now;
+		}
+
+		if(timerisset(&c->conn_timeout)) {
+			c->conn_timeout = then;
+		}
+
 		c->rtt_start.tv_sec = 0;
 	}
 
@@ -2070,19 +2084,24 @@ void utcp_expect_data(struct utcp_connection *c, bool expect) {
 }
 
 void utcp_offline(struct utcp *utcp, bool offline) {
+	struct timeval now;
+	gettimeofday(&now, NULL);
+
 	for(int i = 0; i < utcp->nconnections; i++) {
 		struct utcp_connection *c = utcp->connections[i];
 
-		if(!c->reapable) {
-			utcp_expect_data(c, offline);
-
-			// If we are online again, reset the retransmission timers, but keep the connection timeout as it is,
-			// to prevent peers toggling online/offline state frequently from keeping connections alive
-			// if there is no progress in sending actual data.
-			if(!offline) {
-				gettimeofday(&utcp->connections[i]->rtrx_timeout, NULL);
-				utcp->connections[i]->rtt_start.tv_sec = 0;
+		if(c->reapable) {
+			continue;
+		}
+
+		utcp_expect_data(c, offline);
+
+		if(!offline) {
+			if(timerisset(&c->rtrx_timeout)) {
+				c->rtrx_timeout = now;
 			}
+
+			utcp->connections[i]->rtt_start.tv_sec = 0;
 		}
 	}