X-Git-Url: http://git.meshlink.io/?p=utcp;a=blobdiff_plain;f=utcp.c;h=04d2b194c20f193aa44f2d4006b9afc1bd356b29;hp=19f6cfaf098377bc748de022bdfe506912796482;hb=HEAD;hpb=29d79607fc285618f8441c8810632aa79ceade15

diff --git a/utcp.c b/utcp.c
index 19f6cfa..04d2b19 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;
 	}
@@ -322,7 +322,11 @@ static ssize_t buffer_copy(struct buffer *buf, void *data, size_t offset, size_t
 }
 
 // Copy data from the buffer without removing it.
-static ssize_t buffer_call(struct buffer *buf, utcp_recv_t cb, void *arg, size_t offset, size_t len) {
+static ssize_t buffer_call(struct utcp_connection *c, struct buffer *buf, size_t offset, size_t len) {
+	if(!c->recv) {
+		return len;
+	}
+
 	// Ensure we don't copy more than is actually stored in the buffer
 	if(offset >= buf->used) {
 		return 0;
@@ -334,20 +338,25 @@ 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;
 	}
 
 	if(buf->size - realoffset < len) {
 		// The data is wrapped
-		ssize_t rx1 = cb(arg, buf->data + realoffset, buf->size - realoffset);
+		ssize_t rx1 = c->recv(c, buf->data + realoffset, buf->size - realoffset);
 
 		if(rx1 < buf->size - realoffset) {
 			return rx1;
 		}
 
-		ssize_t rx2 = cb(arg, buf->data, len - (buf->size - realoffset));
+		// The channel might have been closed by the previous callback
+		if(!c->recv) {
+			return len;
+		}
+
+		ssize_t rx2 = c->recv(c, buf->data, len - (buf->size - realoffset));
 
 		if(rx2 < 0) {
 			return rx2;
@@ -355,7 +364,7 @@ static ssize_t buffer_call(struct buffer *buf, utcp_recv_t cb, void *arg, size_t
 			return rx1 + rx2;
 		}
 	} else {
-		return cb(arg, buf->data + realoffset, len);
+		return c->recv(c, buf->data + realoffset, len);
 	}
 }
 
@@ -365,7 +374,7 @@ 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;
 	}
 
@@ -890,6 +899,10 @@ 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[];
@@ -1106,13 +1119,11 @@ static void handle_in_order(struct utcp_connection *c, const void *data, size_t
 			len = c->sacks[0].offset + c->sacks[0].len;
 			size_t remainder = len - offset;
 
-			if(c->recv) {
-				ssize_t rxd = buffer_call(&c->rcvbuf, c->recv, c, offset, remainder);
+			ssize_t rxd = buffer_call(c, &c->rcvbuf, offset, remainder);
 
-				if(rxd != (ssize_t)remainder) {
-					// TODO: handle the application not accepting all data.
-					abort();
-				}
+			if(rxd != (ssize_t)remainder) {
+				// TODO: handle the application not accepting all data.
+				abort();
 			}
 		}
 	}
@@ -1157,8 +1168,8 @@ 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) && c->recv) {
-		buffer_call(&c->rcvbuf, c->recv, c, 0, hdr->wnd + len);
+	if(!(hdr->ctl & MF)) {
+		buffer_call(c, &c->rcvbuf, 0, hdr->wnd + len);
 	}
 
 	c->rcv.nxt = hdr->seq + len;
@@ -1348,6 +1359,8 @@ 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;
@@ -1709,7 +1722,7 @@ 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++;
@@ -1718,7 +1731,6 @@ skip_ack:
 				set_state(c, ESTABLISHED);
 			}
 
-			// TODO: notify application of this somehow.
 			break;
 
 		case SYN_RECEIVED:
@@ -1732,8 +1744,8 @@ 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
@@ -1741,9 +1753,6 @@ skip_ack:
 #endif
 			return 0;
 		}
-
-		// SYN counts as one sequence number
-		c->rcv.nxt++;
 	}
 
 	// 6. Process new data
@@ -2165,6 +2174,13 @@ 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);
@@ -2175,7 +2191,6 @@ 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;
@@ -2447,6 +2462,10 @@ 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;
 }