X-Git-Url: http://git.meshlink.io/?p=utcp;a=blobdiff_plain;f=utcp.c;h=c650ab700ad150fa876b0944a6872ea39298f352;hp=b0ba05428926ba1dd11c7b91c942d27d1fae97e7;hb=5ded633782709710c42648c71154d6062e83b7a6;hpb=7271cf87721ab667a03f50bd40b4a8ec83b989d3

diff --git a/utcp.c b/utcp.c
index b0ba054..c650ab7 100644
--- a/utcp.c
+++ b/utcp.c
@@ -127,6 +127,10 @@ static bool fin_wanted(struct utcp_connection *c, uint32_t seq) {
 	}
 }
 
+static bool is_reliable(struct utcp_connection *c) {
+	return c->flags & UTCP_RELIABLE;
+}
+
 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++)
@@ -142,9 +146,6 @@ static int32_t seqdiff(uint32_t a, uint32_t b) {
 
 // Store data into the buffer
 static ssize_t buffer_put_at(struct buffer *buf, size_t offset, const void *data, size_t len) {
-	if(buf->maxsize <= buf->used)
-		return 0;
-
 	debug("buffer_put_at %lu %lu %lu\n", (unsigned long)buf->used, (unsigned long)offset, (unsigned long)len);
 
 	size_t required = offset + len;
@@ -381,28 +382,38 @@ static void stop_retransmit_timer(struct utcp_connection *c) {
 	debug("timeout cleared\n");
 }
 
-struct utcp_connection *utcp_connect(struct utcp *utcp, uint16_t dst, utcp_recv_t recv, void *priv) {
+struct utcp_connection *utcp_connect_ex(struct utcp *utcp, uint16_t dst, utcp_recv_t recv, void *priv, uint32_t flags) {
 	struct utcp_connection *c = allocate_connection(utcp, 0, dst);
 	if(!c)
 		return NULL;
 
+	assert((flags & ~0xf) == 0);
+
+	c->flags = flags;
 	c->recv = recv;
 	c->priv = priv;
 
-	struct hdr hdr;
-
-	hdr.src = c->src;
-	hdr.dst = c->dst;
-	hdr.seq = c->snd.iss;
-	hdr.ack = 0;
-	hdr.wnd = c->rcv.wnd;
-	hdr.ctl = SYN;
-	hdr.aux = 0;
+	struct {
+		struct hdr hdr;
+		uint8_t init[4];
+	} pkt;
+
+	pkt.hdr.src = c->src;
+	pkt.hdr.dst = c->dst;
+	pkt.hdr.seq = c->snd.iss;
+	pkt.hdr.ack = 0;
+	pkt.hdr.wnd = c->rcv.wnd;
+	pkt.hdr.ctl = SYN;
+	pkt.hdr.aux = 0x0101;
+	pkt.init[0] = 1;
+	pkt.init[1] = 0;
+	pkt.init[2] = 0;
+	pkt.init[3] = flags & 0x7;
 
 	set_state(c, SYN_SENT);
 
-	print_packet(utcp, "send", &hdr, sizeof hdr);
-	utcp->send(utcp, &hdr, sizeof hdr);
+	print_packet(utcp, "send", &pkt, sizeof pkt);
+	utcp->send(utcp, &pkt, sizeof pkt);
 
 	gettimeofday(&c->conn_timeout, NULL);
 	c->conn_timeout.tv_sec += utcp->timeout;
@@ -410,6 +421,10 @@ struct utcp_connection *utcp_connect(struct utcp *utcp, uint16_t dst, utcp_recv_
 	return c;
 }
 
+struct utcp_connection *utcp_connect(struct utcp *utcp, uint16_t dst, utcp_recv_t recv, void *priv) {
+	return utcp_connect_ex(utcp, dst, recv, priv, UTCP_TCP);
+}
+
 void utcp_accept(struct utcp_connection *c, utcp_recv_t recv, void *priv) {
 	if(c->reapable || c->state != SYN_RECEIVED) {
 		debug("Error: accept() called on invalid connection %p in state %s\n", c, strstate[c->state]);
@@ -510,7 +525,7 @@ ssize_t utcp_send(struct utcp_connection *c, const void *data, size_t len) {
 		return -1;
 	}
 
-	// Add data to send buffer
+	// Exit early if we have nothing to send.
 
 	if(!len)
 		return 0;
@@ -520,6 +535,8 @@ ssize_t utcp_send(struct utcp_connection *c, const void *data, size_t len) {
 		return -1;
 	}
 
+	// Add data to send buffer.
+
 	len = buffer_put(&c->sndbuf, data, len);
 	if(len <= 0) {
 		errno = EWOULDBLOCK;
@@ -528,7 +545,11 @@ ssize_t utcp_send(struct utcp_connection *c, const void *data, size_t len) {
 
 	c->snd.last += len;
 	ack(c, false);
-	if(!timerisset(&c->rtrx_timeout))
+	if(!is_reliable(c)) {
+		c->snd.una = c->snd.nxt = c->snd.last;
+		buffer_get(&c->sndbuf, NULL, c->sndbuf.used);
+	}
+	if(is_reliable(c) && !timerisset(&c->rtrx_timeout))
 		start_retransmit_timer(c);
 	return len;
 }
@@ -746,6 +767,12 @@ static void handle_in_order(struct utcp_connection *c, const void *data, size_t
 
 
 static void handle_incoming_data(struct utcp_connection *c, uint32_t seq, const void *data, size_t len) {
+	if(!is_reliable(c)) {
+		c->recv(c, data, len);
+		c->rcv.nxt = seq + len;
+		return;
+	}
+
 	uint32_t offset = seqdiff(seq, c->rcv.nxt);
 	if(offset + len > c->rcvbuf.maxsize)
 		abort();
@@ -822,6 +849,19 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 				goto reset;
 			}
 
+			// Parse auxilliary information
+			if(hdr.aux) {
+				if(hdr.aux != 0x0101 || len < 4 || ((uint8_t *)data)[0] != 1) {
+					len = 1;
+					goto reset;
+				}
+				c->flags = ((uint8_t *)data)[3] & 0x7;
+				data += 4;
+				len -= 4;
+			} else {
+				c->flags = UTCP_TCP;
+			}
+
 			// Return SYN+ACK, go to SYN_RECEIVED state
 			c->snd.wnd = hdr.wnd;
 			c->rcv.irs = hdr.seq;
@@ -893,14 +933,15 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 
 		// cut already accepted front overlapping
 		if(rcv_offset < 0) {
-			acceptable = rcv_offset + len >= 0;
+			acceptable = len > -rcv_offset;
 			if(acceptable) {
 				data -= rcv_offset;
 				len += rcv_offset;
+				hdr.seq -= rcv_offset;
 			}
+		} else {
+			acceptable = seqdiff(hdr.seq, c->rcv.nxt) >= 0 && seqdiff(hdr.seq, c->rcv.nxt) + len <= c->rcvbuf.maxsize;
 		}
-
-		acceptable = seqdiff(hdr.seq, c->rcv.nxt) >= 0 && seqdiff(hdr.seq, c->rcv.nxt) + len <= c->rcvbuf.maxsize;
 	}
 
 	if(!acceptable) {
@@ -908,9 +949,8 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 		// Ignore unacceptable RST packets.
 		if(hdr.ctl & RST)
 			return 0;
-		// Otherwise, send an ACK back in the hope things improve.
-		ack(c, true);
-		return 0;
+		// Otherwise, continue processing.
+		len = 0;
 	}
 
 	c->snd.wnd = hdr.wnd; // TODO: move below
@@ -1048,7 +1088,7 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 			break;
 		}
 	} else {
-		if(!len) {
+		if(!len && is_reliable(c)) {
 			c->dupack++;
 			if(c->dupack == 3) {
 				debug("Triplicate ACK\n");
@@ -1068,7 +1108,7 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 		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);
-		else
+		else if(is_reliable(c))
 			start_retransmit_timer(c);
 	}