X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=utcp.c;h=7624aa576d39c8753c810cea4c4f8643c377d3d4;hb=b1117d6871e6b8babfe8792781480162d7bb6048;hp=d49c4ddcce2cfbf5822efb899b49b4cd186419c4;hpb=56d4c8a695a624dde490d7539f4cd9a4fcea9c06;p=utcp

diff --git a/utcp.c b/utcp.c
index d49c4dd..7624aa5 100644
--- a/utcp.c
+++ b/utcp.c
@@ -103,6 +103,19 @@ static void set_state(struct utcp_connection *c, enum state state) {
 	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++)
@@ -366,16 +379,9 @@ static void ack(struct utcp_connection *c, bool sendatleastone) {
 		c->snd.nxt += seglen;
 		left -= seglen;
 
-		if(c->state != ESTABLISHED && seglen && c->snd.nxt == c->snd.last) {
-			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);
@@ -459,11 +465,8 @@ static void retransmit(struct utcp_connection *c) {
 	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;
@@ -473,6 +476,7 @@ static void retransmit(struct utcp_connection *c) {
 			break;
 
 		case SYN_RECEIVED:
+			// Send SYNACK again
 			pkt->hdr.seq = c->snd.nxt;
 			pkt->hdr.ack = c->rcv.nxt;
 			pkt->hdr.ctl = SYN | ACK;
@@ -482,28 +486,35 @@ static void retransmit(struct utcp_connection *c) {
 
 		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);
-			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;
 			}
+			c->snd.nxt = c->snd.una + len;
 			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;
 	}
 
@@ -978,7 +989,7 @@ reset:
 }
 
 int utcp_shutdown(struct utcp_connection *c, int dir) {
-	debug("%p shutdown %d at %u\n", c ? c->utcp : NULL, dir, c->snd.last);
+	debug("%p shutdown %d at %u\n", c ? c->utcp : NULL, dir, c ? c->snd.last : 0);
 	if(!c) {
 		errno = EFAULT;
 		return -1;
@@ -990,13 +1001,26 @@ int utcp_shutdown(struct utcp_connection *c, int dir) {
 		return -1;
 	}
 
-	// TODO: handle dir
-	// TODO: check that repeated calls with the same parameters should have no effect
+	if(!(dir == UTCP_SHUT_RD || dir == UTCP_SHUT_WR || dir == UTCP_SHUT_RDWR)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	// TCP does not have a provision for stopping incoming packets.
+	// The best we can do is to just ignore them.
+	if(dir == UTCP_SHUT_RD || dir == UTCP_SHUT_RDWR)
+		c->recv = NULL;
+
+	// The rest of the code deals with shutting down writes.
+	if(dir == UTCP_SHUT_RD)
+		return 0;
 
 	switch(c->state) {
 	case CLOSED:
-		return 0;
 	case LISTEN:
+		errno = ENOTCONN;
+		return -1;
+
 	case SYN_SENT:
 		set_state(c, CLOSED);
 		return 0;
@@ -1144,6 +1168,17 @@ struct timeval utcp_timeout(struct utcp *utcp) {
 	return diff;
 }
 
+bool utcp_is_active(struct utcp *utcp) {
+	if(!utcp)
+		return false;
+
+	for(int i = 0; i < utcp->nconnections; i++)
+		if(utcp->connections[i]->state != CLOSED && utcp->connections[i]->state != TIME_WAIT)
+			return true;
+
+	return false;
+}
+
 struct utcp *utcp_init(utcp_accept_t accept, utcp_pre_accept_t pre_accept, utcp_send_t send, void *priv) {
 	struct utcp *utcp = calloc(1, sizeof *utcp);
 	if(!utcp)
@@ -1246,3 +1281,10 @@ void utcp_set_poll_cb(struct utcp_connection *c, utcp_poll_t poll) {
 	if(c)
 		c->poll = poll;
 }
+
+void utcp_set_accept_cb(struct utcp *utcp, utcp_accept_t accept, utcp_pre_accept_t pre_accept) {
+	if(utcp) {
+		utcp->accept = accept;
+		utcp->pre_accept = pre_accept;
+	}
+}