X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=utcp.c;h=fb93f2f62f4cc5e8bbb1d122701a45009dcad131;hb=a4a40a3d8b3b8e62853823afa34e6f4a0b40c1de;hp=aa1c50f79c965709276951f992fd3e681c6feb94;hpb=955836e332b42d9152f6a6b594b1cfd038e639fa;p=utcp

diff --git a/utcp.c b/utcp.c
index aa1c50f..fb93f2f 100644
--- a/utcp.c
+++ b/utcp.c
@@ -268,7 +268,7 @@ static ssize_t buffer_put_at(struct buffer *buf, size_t offset, const void *data
 
 	uint32_t realoffset = buf->offset + offset;
 
-	if(buf->size - buf->offset < offset) {
+	if(buf->size - buf->offset <= offset) {
 		// The offset wrapped
 		realoffset -= buf->size;
 	}
@@ -305,7 +305,7 @@ static ssize_t buffer_copy(struct buffer *buf, void *data, size_t offset, size_t
 
 	uint32_t realoffset = buf->offset + offset;
 
-	if(buf->size - buf->offset < offset) {
+	if(buf->size - buf->offset <= offset) {
 		// The offset wrapped
 		realoffset -= buf->size;
 	}
@@ -334,7 +334,7 @@ static ssize_t buffer_call(struct buffer *buf, utcp_recv_t cb, void *arg, size_t
 
 	uint32_t realoffset = buf->offset + offset;
 
-	if(buf->size - buf->offset < offset) {
+	if(buf->size - buf->offset <= offset) {
 		// The offset wrapped
 		realoffset -= buf->size;
 	}
@@ -365,7 +365,7 @@ static ssize_t buffer_discard(struct buffer *buf, size_t len) {
 		len = buf->used;
 	}
 
-	if(buf->size - buf->offset < len) {
+	if(buf->size - buf->offset <= len) {
 		buf->offset -= buf->size;
 	}
 
@@ -847,13 +847,7 @@ static void fast_retransmit(struct utcp_connection *c) {
 	struct {
 		struct hdr hdr;
 		uint8_t data[];
-	} *pkt;
-
-	pkt = malloc(c->utcp->mtu);
-
-	if(!pkt) {
-		return;
-	}
+	} *pkt = c->utcp->pkt;
 
 	pkt->hdr.src = c->src;
 	pkt->hdr.dst = c->dst;
@@ -885,8 +879,6 @@ static void fast_retransmit(struct utcp_connection *c) {
 	default:
 		break;
 	}
-
-	free(pkt);
 }
 
 static void retransmit(struct utcp_connection *c) {
@@ -898,6 +890,10 @@ static void retransmit(struct utcp_connection *c) {
 
 	struct utcp *utcp = c->utcp;
 
+	if(utcp->retransmit) {
+		utcp->retransmit(c);
+	}
+
 	struct {
 		struct hdr hdr;
 		uint8_t data[];
@@ -1113,11 +1109,14 @@ static void handle_in_order(struct utcp_connection *c, const void *data, size_t
 			size_t offset = len;
 			len = c->sacks[0].offset + c->sacks[0].len;
 			size_t remainder = len - offset;
-			ssize_t rxd = buffer_call(&c->rcvbuf, c->recv, c, offset, remainder);
 
-			if(rxd != (ssize_t)remainder) {
-				// TODO: handle the application not accepting all data.
-				abort();
+			if(c->recv) {
+				ssize_t rxd = buffer_call(&c->rcvbuf, c->recv, c, offset, remainder);
+
+				if(rxd != (ssize_t)remainder) {
+					// TODO: handle the application not accepting all data.
+					abort();
+				}
 			}
 		}
 	}
@@ -1132,7 +1131,10 @@ static void handle_in_order(struct utcp_connection *c, const void *data, size_t
 static void handle_unreliable(struct utcp_connection *c, const struct hdr *hdr, const void *data, size_t len) {
 	// Fast path for unfragmented packets
 	if(!hdr->wnd && !(hdr->ctl & MF)) {
-		c->recv(c, data, len);
+		if(c->recv) {
+			c->recv(c, data, len);
+		}
+
 		c->rcv.nxt = hdr->seq + len;
 		return;
 	}
@@ -1159,7 +1161,7 @@ static void handle_unreliable(struct utcp_connection *c, const struct hdr *hdr,
 	}
 
 	// Send the packet if it's the final fragment
-	if(!(hdr->ctl & MF)) {
+	if(!(hdr->ctl & MF) && c->recv) {
 		buffer_call(&c->rcvbuf, c->recv, c, 0, hdr->wnd + len);
 	}
 
@@ -1350,6 +1352,8 @@ synack:
 				print_packet(c, "send", &pkt, sizeof(hdr));
 				utcp->send(utcp, &pkt, sizeof(hdr));
 			}
+
+			start_retransmit_timer(c);
 		} else {
 			// No, we don't want your packets, send a RST back
 			len = 1;
@@ -1711,7 +1715,7 @@ skip_ack:
 			}
 
 			c->rcv.irs = hdr.seq;
-			c->rcv.nxt = hdr.seq;
+			c->rcv.nxt = hdr.seq + 1;
 
 			if(c->shut_wr) {
 				c->snd.last++;
@@ -1720,7 +1724,6 @@ skip_ack:
 				set_state(c, ESTABLISHED);
 			}
 
-			// TODO: notify application of this somehow.
 			break;
 
 		case SYN_RECEIVED:
@@ -1734,8 +1737,8 @@ skip_ack:
 		case CLOSING:
 		case LAST_ACK:
 		case TIME_WAIT:
-			// Ehm, no. We should never receive a second SYN.
-			return 0;
+			// This could be a retransmission. Ignore the SYN flag, but send an ACK back.
+			break;
 
 		default:
 #ifdef UTCP_DEBUG
@@ -1743,9 +1746,6 @@ skip_ack:
 #endif
 			return 0;
 		}
-
-		// SYN counts as one sequence number
-		c->rcv.nxt++;
 	}
 
 	// 6. Process new data
@@ -2167,6 +2167,13 @@ struct utcp *utcp_init(utcp_accept_t accept, utcp_pre_accept_t pre_accept, utcp_
 		return NULL;
 	}
 
+	utcp_set_mtu(utcp, DEFAULT_MTU);
+
+	if(!utcp->pkt) {
+		free(utcp);
+		return NULL;
+	}
+
 	if(!CLOCK_GRANULARITY) {
 		struct timespec res;
 		clock_getres(UTCP_CLOCK, &res);
@@ -2177,7 +2184,6 @@ struct utcp *utcp_init(utcp_accept_t accept, utcp_pre_accept_t pre_accept, utcp_
 	utcp->pre_accept = pre_accept;
 	utcp->send = send;
 	utcp->priv = priv;
-	utcp_set_mtu(utcp, DEFAULT_MTU);
 	utcp->timeout = DEFAULT_USER_TIMEOUT; // sec
 
 	return utcp;
@@ -2449,6 +2455,10 @@ void utcp_offline(struct utcp *utcp, bool offline) {
 	}
 }
 
+void utcp_set_retransmit_cb(struct utcp *utcp, utcp_retransmit_t retransmit) {
+	utcp->retransmit = retransmit;
+}
+
 void utcp_set_clock_granularity(long granularity) {
 	CLOCK_GRANULARITY = granularity;
 }