X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=utcp.c;h=13f46584484bef5fd71ae74a77792671c1fb7637;hb=16ecd6d75bfabb97193581bcc8095652759cdb8e;hp=7c577018888b0fd99b7cac6f9d66e29b9a0fd91c;hpb=64ef5642d83fc13829262ec6c1bddb6a20d9aa7a;p=utcp

diff --git a/utcp.c b/utcp.c
index 7c57701..13f4658 100644
--- a/utcp.c
+++ b/utcp.c
@@ -49,13 +49,13 @@
 	(r)->tv_sec = (a)->tv_sec - (b)->tv_sec;\
 	(r)->tv_usec = (a)->tv_usec - (b)->tv_usec;\
 	if((r)->tv_usec < 0)\
-		(r)->tv_sec--, (r)->tv_usec += 1000000;\
+		(r)->tv_sec--, (r)->tv_usec += USEC_PER_SEC;\
 } while (0)
 #endif
 
-#ifndef max
-#define max(a, b) ((a) > (b) ? (a) : (b))
-#endif
+static inline size_t max(size_t a, size_t b) {
+	return a > b ? a : b;
+}
 
 #ifdef UTCP_DEBUG
 #include <stdarg.h>
@@ -88,6 +88,10 @@ static void print_packet(struct utcp *utcp, const char *dir, const void *pkt, si
 	if(len > sizeof hdr) {
 		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;
@@ -169,7 +173,7 @@ static ssize_t buffer_put_at(struct buffer *buf, size_t offset, const void *data
 		} else {
 			do {
 				newsize *= 2;
-			} while(newsize < buf->used + len);
+			} while(newsize < required);
 		}
 		if(newsize > buf->maxsize)
 			newsize = buf->maxsize;
@@ -633,7 +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 after ^, 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)
@@ -646,13 +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;
@@ -685,6 +706,8 @@ static void handle_out_of_order(struct utcp_connection *c, uint32_t offset, cons
 					memmove(&c->sacks[i + 1], &c->sacks[i], (NSACKS - i - 1) * sizeof c->sacks[i]);
 					c->sacks[i].offset = offset;
 					c->sacks[i].len = rxd;
+				} else {
+					debug("SACK entries full, dropping packet\n");
 				}
 				break;
 			} else { // merge
@@ -834,8 +857,10 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 	// In case this is for a CLOSED connection, ignore the packet.
 	// TODO: make it so incoming packets can never match a CLOSED connection.
 
-	if(c->state == CLOSED)
+	if(c->state == CLOSED) {
+		debug("Got packet for closed connection\n");
 		return 0;
+	}
 
 	// It is for an existing connection.
 
@@ -1271,7 +1296,7 @@ int utcp_shutdown(struct utcp_connection *c, int dir) {
 }
 
 int utcp_close(struct utcp_connection *c) {
-	if(utcp_shutdown(c, SHUT_RDWR))
+	if(utcp_shutdown(c, SHUT_RDWR) && errno != ENOTCONN)
 		return -1;
 	c->recv = NULL;
 	c->poll = NULL;
@@ -1411,8 +1436,8 @@ struct utcp *utcp_init(utcp_accept_t accept, utcp_pre_accept_t pre_accept, utcp_
 	utcp->send = send;
 	utcp->priv = priv;
 	utcp->mtu = DEFAULT_MTU;
-	utcp->timeout = DEFAULT_USER_TIMEOUT; // s
-	utcp->rto = START_RTO; // us
+	utcp->timeout = DEFAULT_USER_TIMEOUT; // sec
+	utcp->rto = START_RTO; // usec
 
 	return utcp;
 }