X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=utcp.c;h=ce056904169c6923baa95a0e5435626e5da75fd5;hb=f268b8518415a5cf896e1b3518c2a0141d1364d4;hp=f5484ab82b92e53e5365f7de75a822881218a7f4;hpb=aef3cad25ea81f727608689ef97fce9e0dbe5285;p=utcp

diff --git a/utcp.c b/utcp.c
index f5484ab..ce05690 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++)
@@ -269,7 +282,12 @@ static struct utcp_connection *allocate_connection(struct utcp *utcp, uint16_t s
 
 	c->src = src;
 	c->dst = dst;
+#ifdef UTCP_DEBUG
+#warning debugging
+	c->snd.iss = 0;
+#else
 	c->snd.iss = rand();
+#endif
 	c->snd.una = c->snd.iss;
 	c->snd.nxt = c->snd.iss + 1;
 	c->rcv.wnd = utcp->mtu;
@@ -347,7 +365,7 @@ static void ack(struct utcp_connection *c, bool sendatleastone) {
 	} *pkt;
 
 	pkt = malloc(sizeof pkt->hdr + c->utcp->mtu);
-	if(!pkt->data)
+	if(!pkt)
 		return;
 
 	pkt->hdr.src = c->src;
@@ -366,16 +384,9 @@ static void ack(struct utcp_connection *c, bool sendatleastone) {
 		c->snd.nxt += 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;
-			}
+		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 +470,8 @@ 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 +481,7 @@ 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;
@@ -482,26 +491,36 @@ 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;
 	}
 
 	free(pkt);
@@ -623,7 +642,10 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 	case TIME_WAIT:
 		break;
 	default:
+#ifdef UTCP_DEBUG
 		abort();
+#endif
+		break;
 	}
 
 	// 1b. Drop packets with a sequence number not in our receive window.
@@ -723,7 +745,10 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 			set_state(c, CLOSED);
 			return 0;
 		default:
+#ifdef UTCP_DEBUG
 			abort();
+#endif
+			break;
 		}
 	}
 
@@ -822,7 +847,10 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 			// Ehm, no. We should never receive a second SYN.
 			goto reset;
 		default:
+#ifdef UTCP_DEBUG
 			abort();
+#endif
+			return 0;
 		}
 
 		// SYN counts as one sequence number
@@ -852,7 +880,10 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 		case SYN_SENT:
 		case SYN_RECEIVED:
 			// This should never happen.
+#ifdef UTCP_DEBUG
 			abort();
+#endif
+			return 0;
 		case ESTABLISHED:
 		case FIN_WAIT_1:
 		case FIN_WAIT_2:
@@ -864,7 +895,10 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 			// Ehm no, We should never receive more data after a FIN.
 			goto reset;
 		default:
+#ifdef UTCP_DEBUG
 			abort();
+#endif
+			return 0;
 		}
 
 		ssize_t rxd;
@@ -893,7 +927,10 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 		case SYN_SENT:
 		case SYN_RECEIVED:
 			// This should never happen.
+#ifdef UTCP_DEBUG
 			abort();
+#endif
+			break;
 		case ESTABLISHED:
 			set_state(c, CLOSE_WAIT);
 			break;
@@ -912,7 +949,10 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 			// Ehm, no. We should never receive a second FIN.
 			goto reset;
 		default:
+#ifdef UTCP_DEBUG
 			abort();
+#endif
+			break;
 		}
 
 		// FIN counts as one sequence number
@@ -954,7 +994,7 @@ reset:
 }
 
 int utcp_shutdown(struct utcp_connection *c, int dir) {
-	debug("%p shutdown %d\n", c ? c->utcp : NULL, dir);
+	debug("%p shutdown %d at %u\n", c ? c->utcp : NULL, dir, c ? c->snd.last : 0);
 	if(!c) {
 		errno = EFAULT;
 		return -1;
@@ -966,12 +1006,26 @@ int utcp_shutdown(struct utcp_connection *c, int dir) {
 		return -1;
 	}
 
-	// TODO: handle dir
+	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;
@@ -1119,6 +1173,17 @@ 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)
@@ -1153,60 +1218,78 @@ void utcp_exit(struct utcp *utcp) {
 }
 
 uint16_t utcp_get_mtu(struct utcp *utcp) {
-	return utcp->mtu;
+	return utcp ? utcp->mtu : 0;
 }
 
 void utcp_set_mtu(struct utcp *utcp, uint16_t mtu) {
 	// TODO: handle overhead of the header
-	utcp->mtu = mtu;
+	if(utcp)
+		utcp->mtu = mtu;
 }
 
 int utcp_get_user_timeout(struct utcp *u) {
-	return u->timeout;
+	return u ? u->timeout : 0;
 }
 
 void utcp_set_user_timeout(struct utcp *u, int timeout) {
-	u->timeout = timeout;
+	if(u)
+		u->timeout = timeout;
 }
 
 size_t utcp_get_sndbuf(struct utcp_connection *c) {
-	return c->sndbuf.maxsize;
+	return c ? c->sndbuf.maxsize : 0;
 }
 
 size_t utcp_get_sndbuf_free(struct utcp_connection *c) {
-	return buffer_free(&c->sndbuf);
+	if(c && (c->state == ESTABLISHED || c->state == CLOSE_WAIT))
+		return buffer_free(&c->sndbuf);
+	else
+		return 0;
 }
 
 void utcp_set_sndbuf(struct utcp_connection *c, size_t size) {
+	if(!c)
+		return;
 	c->sndbuf.maxsize = size;
 	if(c->sndbuf.maxsize != size)
 		c->sndbuf.maxsize = -1;
 }
 
 bool utcp_get_nodelay(struct utcp_connection *c) {
-	return c->nodelay;
+	return c ? c->nodelay : false;
 }
 
 void utcp_set_nodelay(struct utcp_connection *c, bool nodelay) {
-	c->nodelay = nodelay;
+	if(c)
+		c->nodelay = nodelay;
 }
 
 bool utcp_get_keepalive(struct utcp_connection *c) {
-	return c->keepalive;
+	return c ? c->keepalive : false;
 }
 
 void utcp_set_keepalive(struct utcp_connection *c, bool keepalive) {
-	c->keepalive = keepalive;
+	if(c)
+		c->keepalive = keepalive;
 }
 
 size_t utcp_get_outq(struct utcp_connection *c) {
-	return seqdiff(c->snd.nxt, c->snd.una);
+	return c ? seqdiff(c->snd.nxt, c->snd.una) : 0;
 }
 
 void utcp_set_recv_cb(struct utcp_connection *c, utcp_recv_t recv) {
-	c->recv = recv;
+	if(c)
+		c->recv = recv;
 }
 
 void utcp_set_poll_cb(struct utcp_connection *c, utcp_poll_t poll) {
-	c->poll = 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;
+	}
 }