X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=utcp.c;h=57b98135ad482b5cb29dbe6f9549db6ac6adaeaa;hb=1d8aa0d5a55bb871ce56bca355ade80b08a7c1e5;hp=a8ea8272972650a773b45009f83e23ec02da4d05;hpb=b2e5de6b537188f77e1889853f6ba919bf35c77c;p=utcp

diff --git a/utcp.c b/utcp.c
index a8ea827..57b9813 100644
--- a/utcp.c
+++ b/utcp.c
@@ -75,7 +75,7 @@ static void print_packet(struct utcp *utcp, const char *dir, const void *pkt, si
 	}
 
 	memcpy(&hdr, pkt, sizeof hdr);
-	debug("%p %s: len=%lu, src=%u dst=%u seq=%u ack=%u wnd=%u ctl=", utcp, dir, (unsigned long)len, hdr.src, hdr.dst, hdr.seq, hdr.ack, hdr.wnd);
+	debug("%p %s: len=%lu, src=%u dst=%u seq=%u ack=%u wnd=%u aux=%x ctl=", utcp, dir, (unsigned long)len, hdr.src, hdr.dst, hdr.seq, hdr.ack, hdr.wnd, hdr.aux);
 	if(hdr.ctl & SYN)
 		debug("SYN");
 	if(hdr.ctl & RST)
@@ -457,7 +457,7 @@ static void ack(struct utcp_connection *c, bool sendatleastone) {
 
 	struct {
 		struct hdr hdr;
-		char data[];
+		uint8_t data[];
 	} *pkt;
 
 	pkt = malloc(sizeof pkt->hdr + c->utcp->mtu);
@@ -573,7 +573,7 @@ static void retransmit(struct utcp_connection *c) {
 
 	struct {
 		struct hdr hdr;
-		char data[];
+		uint8_t data[];
 	} *pkt;
 
 	pkt = malloc(sizeof pkt->hdr + c->utcp->mtu);
@@ -587,7 +587,6 @@ static void retransmit(struct utcp_connection *c) {
 
 	switch(c->state) {
 		case SYN_SENT:
-			fprintf(stderr, "Retransmitting SYN\n");
 			// Send our SYN again
 			pkt->hdr.seq = c->snd.iss;
 			pkt->hdr.ack = 0;
@@ -829,6 +828,49 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 		return -1;
 	}
 
+	// Check for auxiliary headers
+
+	const uint8_t *init = NULL;
+
+	uint16_t aux = hdr.aux;
+	while(aux) {
+		size_t auxlen = 4 * (aux >> 8) & 0xf;
+		uint8_t auxtype = aux & 0xff;
+
+		if(len < auxlen) {
+			errno = EBADMSG;
+			return -1;
+		}
+
+		switch(auxtype) {
+		case AUX_INIT:
+			if(!(hdr.ctl & SYN) || auxlen != 4) {
+				errno = EBADMSG;
+				return -1;
+			}
+			init = data;
+			break;
+		default:
+			errno = EBADMSG;
+			return -1;
+		}
+
+		len -= auxlen;
+		data += auxlen;
+
+		if(!(aux & 0x800))
+			break;
+
+		if(len < 2) {
+			errno = EBADMSG;
+			return -1;
+		}
+
+		memcpy(&aux, data, 2);
+		len -= 2;
+		data += 2;
+	}
+
 	// Try to match the packet to an existing connection
 
 	struct utcp_connection *c = find_connection(utcp, hdr.dst, hdr.src);
@@ -858,14 +900,12 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 			}
 
 			// Parse auxilliary information
-			if(hdr.aux) {
-				if(hdr.aux != 0x0101 || len < 4 || ((uint8_t *)data)[0] != 1) {
+			if(init) {
+				if(init[0] < 1) {
 					len = 1;
 					goto reset;
 				}
-				c->flags = ((uint8_t *)data)[3] & 0x7;
-				data += 4;
-				len -= 4;
+				c->flags = init[3] & 0x7;
 			} else {
 				c->flags = UTCP_TCP;
 			}
@@ -876,13 +916,30 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 			c->rcv.nxt = c->rcv.irs + 1;
 			set_state(c, SYN_RECEIVED);
 
-			hdr.dst = c->dst;
-			hdr.src = c->src;
-			hdr.ack = c->rcv.irs + 1;
-			hdr.seq = c->snd.iss;
-			hdr.ctl = SYN | ACK;
-			print_packet(c->utcp, "send", &hdr, sizeof hdr);
-			utcp->send(utcp, &hdr, sizeof hdr);
+			struct {
+				struct hdr hdr;
+				uint8_t data[4];
+			} pkt;
+
+			pkt.hdr.src = c->src;
+			pkt.hdr.dst = c->dst;
+			pkt.hdr.ack = c->rcv.irs + 1;
+			pkt.hdr.seq = c->snd.iss;
+			pkt.hdr.wnd = c->rcv.wnd;
+			pkt.hdr.ctl = SYN | ACK;
+			if(init) {
+				pkt.hdr.aux = 0x0101;
+				pkt.data[0] = 1;
+				pkt.data[1] = 0;
+				pkt.data[2] = 0;
+				pkt.data[3] = c->flags & 0x7;
+				print_packet(c->utcp, "send", &pkt, sizeof hdr + 4);
+				utcp->send(utcp, &pkt, sizeof hdr + 4);
+			} else {
+				pkt.hdr.aux = 0;
+				print_packet(c->utcp, "send", &pkt, sizeof hdr);
+				utcp->send(utcp, &pkt, sizeof hdr);
+			}
 		} else {
 			// No, we don't want your packets, send a RST back
 			len = 1;
@@ -1028,6 +1085,9 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 		}
 	}
 
+	if(!(hdr.ctl & ACK))
+		goto skip_ack;
+
 	// 3. Advance snd.una
 
 	uint32_t advanced = seqdiff(hdr.ack, c->snd.una);
@@ -1120,6 +1180,7 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 			start_retransmit_timer(c);
 	}
 
+skip_ack:
 	// 5. Process SYN stuff
 
 	if(hdr.ctl & SYN) {
@@ -1142,7 +1203,7 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 		case LAST_ACK:
 		case TIME_WAIT:
 			// Ehm, no. We should never receive a second SYN.
-			goto reset;
+			return 0;
 		default:
 #ifdef UTCP_DEBUG
 			abort();
@@ -1259,6 +1320,7 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) {
 reset:
 	swap_ports(&hdr);
 	hdr.wnd = 0;
+	hdr.aux = 0;
 	if(hdr.ctl & ACK) {
 		hdr.seq = hdr.ack;
 		hdr.ctl = RST;
@@ -1493,11 +1555,13 @@ void utcp_exit(struct utcp *utcp) {
 	if(!utcp)
 		return;
 	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]);
+		struct utcp_connection *c = utcp->connections[i];
+		if(!c->reapable)
+			if(c->recv)
+				c->recv(c, NULL, 0);
+		buffer_exit(&c->rcvbuf);
+		buffer_exit(&c->sndbuf);
+		free(c);
 	}
 	free(utcp->connections);
 	free(utcp);
@@ -1513,6 +1577,22 @@ void utcp_set_mtu(struct utcp *utcp, uint16_t mtu) {
 		utcp->mtu = mtu;
 }
 
+void utcp_reset_timers(struct utcp *utcp) {
+	if(!utcp)
+		return;
+	struct timeval now, then;
+	gettimeofday(&now, NULL);
+	then = now;
+	then.tv_sec += utcp->timeout;
+	for(int i = 0; i < utcp->nconnections; i++) {
+		utcp->connections[i]->rtrx_timeout = now;
+		utcp->connections[i]->conn_timeout = then;
+		utcp->connections[i]->rtt_start.tv_sec = 0;
+	}
+	if(utcp->rto > START_RTO)
+		utcp->rto = START_RTO;
+}
+
 int utcp_get_user_timeout(struct utcp *u) {
 	return u ? u->timeout : 0;
 }