Replace two hardcoded timeout values with utcp->timeout.

[utcp] / utcp.c

diff --git a/utcp.c b/utcp.c
index 7e28f9e27e3aef2a7f0937597eabbd5bd3c36f7a..ac162fe708a0d657abffb4cb62ecd4881a7fc79a 100644 (file)
--- a/utcp.c
+++ b/utcp.c
@@ -1011,6 +1011,8 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
                ptr += 2;
        }
 
+       bool has_data = len || (hdr.ctl & (SYN | FIN));
+
        // Try to match the packet to an existing connection
 
        struct utcp_connection *c = find_connection(utcp, hdr.dst, hdr.src);
@@ -1105,8 +1107,6 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 
        // It is for an existing connection.
 
-       uint32_t prevrcvnxt = c->rcv.nxt;
-
        // 1. Drop invalid packets.
 
        // 1a. Drop packets that should not happen in our current state.
@@ -1130,7 +1130,7 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
                break;
        }
 
-       // 1b. Drop packets with a sequence number not in our receive window.
+       // 1b. Discard data that is not in our receive window.
 
        if(is_reliable(c)) {
                bool acceptable;
@@ -1282,7 +1282,6 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
        // 3. Advance snd.una
 
        advanced = seqdiff(hdr.ack, c->snd.una);
-       prevrcvnxt = c->rcv.nxt;
 
        if(advanced) {
                // RTT measurement
@@ -1347,7 +1346,7 @@ 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);
                        }
 
@@ -1506,7 +1505,7 @@ 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;
 
@@ -1536,13 +1535,13 @@ skip_ack:
        }
 
        // Now we send something back if:
-       // - we advanced rcv.nxt (ie, we got some data that needs to be ACKed)
+       // - we received data, so we have to send back an ACK
        //   -> sendatleastone = true
        // - or we got an ack, so we should maybe send a bit more data
        //   -> sendatleastone = false
 
        if(is_reliable(c) || hdr.ctl & SYN || hdr.ctl & FIN) {
-               ack(c, len || prevrcvnxt != c->rcv.nxt);
+               ack(c, has_data);
        }
 
        return 0;
@@ -1919,8 +1918,14 @@ 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;
        }
 
@@ -2071,19 +2076,24 @@ 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;
                }
        }