Set FIN bit in ack().

[utcp] / utcp.c

diff --git a/utcp.c b/utcp.c
index 454a497428dd0e698db2bdeae92189fda41eb0fb..730f12b98e8102a42d85c2d6f1fb55971728beec 100644 (file)
--- a/utcp.c
+++ b/utcp.c
@@ -233,10 +233,14 @@ void utcp_accept(struct utcp_connection *c, utcp_recv_t recv, void *priv) {
 }
 
 static void ack(struct utcp_connection *c, bool sendatleastone) {
-       uint32_t left = seqdiff(c->snd.last, c->snd.nxt);
+       int32_t left = seqdiff(c->snd.last, c->snd.nxt);
        int32_t cwndleft = c->snd.cwnd - seqdiff(c->snd.nxt, c->snd.una);
        char *data = c->sndbuf + seqdiff(c->snd.nxt, c->snd.una);
 
+       fprintf(stderr, "ack, left=%d, cwndleft=%d, sendatleastone=%d\n", left, cwndleft, sendatleastone);
+       if(left < 0)
+               abort();
+
        if(cwndleft <= 0)
                cwndleft = 0;
 
@@ -267,6 +271,18 @@ static void ack(struct utcp_connection *c, bool sendatleastone) {
                data += 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;
+                       }
+               }
+
                print_packet(c->utcp, "send", &pkt, sizeof pkt.hdr + seglen);
                c->utcp->send(c->utcp, &pkt, sizeof pkt.hdr + seglen);
        } while(left);
@@ -324,6 +340,12 @@ ssize_t utcp_send(struct utcp_connection *c, const void *data, size_t len) {
                        newbufsize = c->maxsndbufsize;
                else
                        newbufsize = c->sndbufsize * 2;
+               if(bufused + len > newbufsize) {
+                       if(bufused + len > c->maxsndbufsize)
+                               newbufsize = c->maxsndbufsize;
+                       else
+                               newbufsize = bufused + len;
+               }
                char *newbuf = realloc(c->sndbuf, newbufsize);
                if(newbuf) {
                        c->sndbuf = newbuf;
@@ -584,6 +606,24 @@ int utcp_recv(struct utcp *utcp, const void *data, size_t len) {
                c->snd.cwnd += utcp->mtu;
                if(c->snd.cwnd > c->maxsndbufsize)
                        c->snd.cwnd = c->maxsndbufsize;
+               debug("%p increasing cwnd to %u\n", utcp, c->snd.cwnd);
+
+               // Check if we have sent a FIN that is now ACKed.
+               switch(c->state) {
+               case FIN_WAIT_1:
+                       if(c->snd.una == c->snd.last)
+                               set_state(c, FIN_WAIT_2);
+                       break;
+               case CLOSING:
+                       if(c->snd.una == c->snd.last) {
+                               gettimeofday(&c->conn_timeout, NULL);
+                               c->conn_timeout.tv_sec += 60;
+                               set_state(c, TIME_WAIT);
+                       }
+                       break;
+               default:
+                       break;
+               }
        } else {
                if(!len) {
                        c->dupack++;
@@ -701,6 +741,8 @@ int utcp_recv(struct utcp *utcp, const void *data, size_t len) {
                        set_state(c, CLOSING);
                        break;
                case FIN_WAIT_2:
+                       gettimeofday(&c->conn_timeout, NULL);
+                       c->conn_timeout.tv_sec += 60;
                        set_state(c, TIME_WAIT);
                        break;
                case CLOSE_WAIT:
@@ -790,21 +832,9 @@ int utcp_shutdown(struct utcp_connection *c, int dir) {
                return 0;
        }
 
-       // Send FIN
+       c->snd.last++;
 
-       struct hdr hdr;
-
-       hdr.src = c->src;
-       hdr.dst = c->dst;
-       hdr.seq = c->snd.nxt;
-       hdr.ack = c->rcv.nxt;
-       hdr.wnd = c->snd.wnd;
-       hdr.ctl = FIN | ACK;
-
-       c->snd.nxt += 1;
-
-       print_packet(c->utcp, "send", &hdr, sizeof hdr);
-       c->utcp->send(c->utcp, &hdr, sizeof hdr);
+       ack(c, false);
        return 0;
 }