X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=utcp.c;h=95a82c428710ca91f5f2752045eea036bee40c79;hb=05ee8ad65c1c7f1318e1185ddf299a2cce6c6474;hp=c125ce0a04d50414b69f22a9cae4abbf62f5f25a;hpb=ed4df96a87e00d88de755b73d041777615201973;p=utcp

diff --git a/utcp.c b/utcp.c
index c125ce0..95a82c4 100644
--- a/utcp.c
+++ b/utcp.c
@@ -86,11 +86,28 @@ static void print_packet(struct utcp *utcp, const char *dir, const void *pkt, si
 		debug("ACK");
 
 	if(len > sizeof hdr) {
-		debug(" data=");
-		for(int i = sizeof hdr; i < len; i++) {
-			const char *data = pkt;
-			debug("%c", data[i] >= 32 ? data[i] : '.');
+		uint32_t datalen = len - sizeof hdr;
+		uint8_t *str = malloc((datalen << 1) + 7);
+		if(!str) {
+			debug("out of memory");
+			return;
 		}
+		memcpy(str, " data=", 6);
+		uint8_t *strptr = str + 6;
+		const uint8_t *data = pkt;
+		const uint8_t *dataend = data + datalen;
+
+		while(data != dataend) {
+			*strptr = (*data >> 4) > 9? (*data >> 4) + 55 : (*data >> 4) + 48;
+			++strptr;
+			*strptr = (*data & 0xf) > 9? (*data & 0xf) + 55 : (*data & 0xf) + 48;
+			++strptr;
+			++data;
+		}
+		*strptr = 0;
+
+		debug(str);
+		free(str);
 	}
 
 	debug("\n");
@@ -260,6 +277,7 @@ static void free_connection(struct utcp_connection *c) {
 	memmove(cp, cp + 1, (utcp->nconnections - i - 1) * sizeof *cp);
 	utcp->nconnections--;
 
+	buffer_exit(&c->rcvbuf);
 	buffer_exit(&c->sndbuf);
 	free(c);
 }
@@ -305,6 +323,7 @@ static struct utcp_connection *allocate_connection(struct utcp *utcp, uint16_t s
 	}
 
 	if(!buffer_init(&c->rcvbuf, DEFAULT_RCVBUFSIZE, DEFAULT_MAXRCVBUFSIZE)) {
+		buffer_exit(&c->sndbuf);
 		free(c);
 		return NULL;
 	}
@@ -532,8 +551,11 @@ static void swap_ports(struct hdr *hdr) {
 }
 
 static void retransmit(struct utcp_connection *c) {
-	if(c->state == CLOSED || c->snd.nxt == c->snd.una)
+	if(c->state == CLOSED || c->snd.last == c->snd.una) {
+		debug("Retransmit() called but nothing to retransmit!\n");
+		stop_retransmit_timer(c);
 		return;
+	}
 
 	struct utcp *utcp = c->utcp;
 
@@ -548,13 +570,14 @@ static void retransmit(struct utcp_connection *c) {
 
 	pkt->hdr.src = c->src;
 	pkt->hdr.dst = c->dst;
+	pkt->hdr.wnd = c->rcv.wnd;
+	pkt->hdr.aux = 0;
 
 	switch(c->state) {
 		case SYN_SENT:
 			// Send our SYN again
 			pkt->hdr.seq = c->snd.iss;
 			pkt->hdr.ack = 0;
-			pkt->hdr.wnd = c->rcv.wnd;
 			pkt->hdr.ctl = SYN;
 			print_packet(c->utcp, "rtrx", pkt, sizeof pkt->hdr);
 			utcp->send(utcp, pkt, sizeof pkt->hdr);
@@ -614,7 +637,24 @@ cleanup:
 	free(pkt);
 }
 
-// Update receive buffer and SACK entries after consuming data.
+/* Update receive buffer and SACK entries after consuming data.
+ *
+ * Situation:
+ *
+ * |.....0000..1111111111.....22222......3333|
+ * |---------------^
+ *
+ * 0..3 represent the SACK entries. The ^ indicates up to which point we want
+ * to remove data from the receive buffer. The idea is to substract "len"
+ * from the offset of all the SACK entries, and then remove/cut down entries
+ * that are shifted to before the start of the receive buffer.
+ *
+ * There are three cases:
+ * - the SACK entry is ahead of ^, in that case just change the offset.
+ * - the SACK entry starts before and ends after ^, so we have to
+ *   change both its offset and size.
+ * - the SACK entry is completely before ^, in that case delete it.
+ */
 static void sack_consume(struct utcp_connection *c, size_t len) {
 	debug("sack_consume %zu\n", len);
 	if(len > c->rcvbuf.used)
@@ -627,13 +667,13 @@ static void sack_consume(struct utcp_connection *c, size_t len) {
 			c->sacks[i].offset -= len;
 			i++;
 		} else if(len < c->sacks[i].offset + c->sacks[i].len) {
-			c->sacks[i].offset = 0;
 			c->sacks[i].len -= len - c->sacks[i].offset;
+			c->sacks[i].offset = 0;
 			i++;
 		} else {
 			if(i < NSACKS - 1) {
 				memmove(&c->sacks[i], &c->sacks[i + 1], (NSACKS - 1 - i) * sizeof c->sacks[i]);
-				c->sacks[i + 1].len = 0;
+				c->sacks[NSACKS - 1].len = 0;
 			} else {
 				c->sacks[i].len = 0;
 				break;
@@ -1246,6 +1286,8 @@ int utcp_shutdown(struct utcp_connection *c, int dir) {
 	c->snd.last++;
 
 	ack(c, false);
+	if(!timerisset(&c->rtrx_timeout))
+		start_retransmit_timer(c);
 	return 0;
 }
 
@@ -1402,6 +1444,7 @@ void utcp_exit(struct utcp *utcp) {
 	for(int i = 0; i < utcp->nconnections; i++) {
 		if(!utcp->connections[i]->reapable)
 			debug("Warning, freeing unclosed connection %p\n", utcp->connections[i]);
+		buffer_exit(&utcp->connections[i]->rcvbuf);
 		buffer_exit(&utcp->connections[i]->sndbuf);
 		free(utcp->connections[i]);
 	}