Add a flag to prevent partial writes on a UTCP connection.

[utcp] / utcp.c

diff --git a/utcp.c b/utcp.c
index d09b9e7d526e80c4ce39590c19c718904fe32590..5938ea5bcea6af1a99b9d2e885b8fd68bdf70435 100644 (file)
--- a/utcp.c
+++ b/utcp.c
@@ -611,6 +611,20 @@ ssize_t utcp_send(struct utcp_connection *c, const void *data, size_t len) {
                return -1;
        }
 
+       // Check if we need to be able to buffer all data
+
+       if(c->flags & UTCP_NO_PARTIAL) {
+               if(len > buffer_free(&c->sndbuf)) {
+                       if(len > c->sndbuf.maxsize) {
+                               errno = EMSGSIZE;
+                               return -1;
+                       } else {
+                               errno = EWOULDBLOCK;
+                               return 0;
+                       }
+               }
+       }
+
        // Add data to send buffer.
 
        len = buffer_put(&c->sndbuf, data, len);
@@ -639,6 +653,11 @@ ssize_t utcp_send(struct utcp_connection *c, const void *data, size_t len) {
                start_retransmit_timer(c);
        }
 
+       if(is_reliable(c) && !timerisset(&c->conn_timeout)) {
+               gettimeofday(&c->conn_timeout, NULL);
+               c->conn_timeout.tv_sec += c->utcp->timeout;
+       }
+
        return len;
 }
 
@@ -1334,12 +1353,13 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
        // 4. Update timers
 
        if(advanced) {
-               timerclear(&c->conn_timeout); // It will be set anew in utcp_timeout() if c->snd.una != c->snd.nxt.
-
                if(c->snd.una == c->snd.last) {
                        stop_retransmit_timer(c);
+                       timerclear(&c->conn_timeout);
                } else if(is_reliable(c)) {
                        start_retransmit_timer(c);
+                       gettimeofday(&c->conn_timeout, NULL);
+                       c->conn_timeout.tv_sec += utcp->timeout;
                }
        }
 
@@ -1664,11 +1684,13 @@ void utcp_abort_all_connections(struct utcp *utcp) {
                        continue;
                }
 
+               utcp_recv_t old_recv = c->recv;
+
                reset_connection(c);
 
-               if(c->recv) {
+               if(old_recv) {
                        errno = 0;
-                       c->recv(c, NULL, 0);
+                       old_recv(c, NULL, 0);
                }
        }
 
@@ -1732,6 +1754,10 @@ struct timeval utcp_timeout(struct utcp *utcp) {
                                c->recv(c, NULL, 0);
                        }
 
+                       if(c->poll) {
+                               c->poll(c, 0);
+                       }
+
                        continue;
                }
 
@@ -1851,9 +1877,15 @@ void utcp_reset_timers(struct utcp *utcp) {
        then.tv_sec += utcp->timeout;
 
        for(int i = 0; i < utcp->nconnections; i++) {
-               utcp->connections[i]->rtrx_timeout = now;
-               utcp->connections[i]->conn_timeout = then;
-               utcp->connections[i]->rtt_start.tv_sec = 0;
+               struct utcp_connection *c = utcp->connections[i];
+
+               if(c->reapable) {
+                       continue;
+               }
+
+               c->rtrx_timeout = now;
+               c->conn_timeout = then;
+               c->rtt_start.tv_sec = 0;
        }
 
        if(utcp->rto > START_RTO) {
@@ -1928,6 +1960,14 @@ void utcp_set_rcvbuf(struct utcp_connection *c, size_t size) {
        }
 }
 
+size_t utcp_get_sendq(struct utcp_connection *c) {
+       return c->sndbuf.used;
+}
+
+size_t utcp_get_recvq(struct utcp_connection *c) {
+       return c->rcvbuf.used;
+}
+
 bool utcp_get_nodelay(struct utcp_connection *c) {
        return c ? c->nodelay : false;
 }
@@ -1970,3 +2010,48 @@ void utcp_set_accept_cb(struct utcp *utcp, utcp_accept_t accept, utcp_pre_accept
                utcp->pre_accept = pre_accept;
        }
 }
+
+void utcp_expect_data(struct utcp_connection *c, bool expect) {
+       if(!c || c->reapable) {
+               return;
+       }
+
+       if(!(c->state == ESTABLISHED || c->state == FIN_WAIT_1 || c->state == FIN_WAIT_2)) {
+               return;
+       }
+
+       if(expect) {
+               // If we expect data, start the connection timer.
+               if(!timerisset(&c->conn_timeout)) {
+                       gettimeofday(&c->conn_timeout, NULL);
+                       c->conn_timeout.tv_sec += c->utcp->timeout;
+               }
+       } else {
+               // If we want to cancel expecting data, only clear the timer when there is no unACKed data.
+               if(c->snd.una == c->snd.last) {
+                       timerclear(&c->conn_timeout);
+               }
+       }
+}
+
+void utcp_offline(struct utcp *utcp, bool offline) {
+       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(!offline && utcp->rto > START_RTO) {
+               utcp->rto = START_RTO;
+       }
+}