Use a status bit to track which nodes use SPTPS.

src/graph.c

@@ -226,6 +226,9 @@ static void check_reachability(void) {
 					   n->name, n->hostname);
 			}
 
+			if(experimental && OPTION_VERSION(n->options) >= 2)
+				n->status.sptps = true;
+
 			/* TODO: only clear status.validkey if node is unreachable? */
 
 			n->status.validkey = false;
@@ -266,7 +269,7 @@ static void check_reachability(void) {
 			if(!n->status.reachable) {
 				update_node_udp(n, NULL);
 			} else if(n->connection) {
-				if(experimental && OPTION_VERSION(n->options) >= 2) {
+				if(n->status.sptps) {
 					if(n->connection->outgoing)
 						send_req_key(n);
 				} else {

src/info.c

@@ -104,6 +104,8 @@ static int info_node(int fd, const char *item) {
 		printf(" reachable");
 	if(status.indirect)
 		printf(" indirect");
+	if(status.sptps)
+		printf(" sptps");
 	printf("\n");
 	printf("Options:     ");
 	if(options & OPTION_INDIRECT)

src/net_packet.c

@@ -252,7 +252,7 @@ static void receive_packet(node_t *n, vpn_packet_t *packet) {
 }
 
 static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
-	if(experimental && OPTION_VERSION(n->options) >= 2)
+	if(n->status.sptps)
 		return sptps_verify_datagram(&n->sptps, (char *)inpkt->data - 4, inpkt->len);
 
 	if(!digest_active(&n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest))
@@ -268,7 +268,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 	vpn_packet_t *outpkt = pkt[0];
 	size_t outlen;
 
-	if(experimental && OPTION_VERSION(n->options) >= 2) {
+	if(n->status.sptps) {
 		sptps_receive_data(&n->sptps, (char *)inpkt->data - 4, inpkt->len);
 		return;
 	}
@@ -438,7 +438,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 		return;
 	}
 
-	if(experimental && OPTION_VERSION(n->options) >= 2) {
+	if(n->status.sptps) {
 		uint8_t type = 0;
 		if(!(inpkt->data[12] | inpkt->data[13]))
 			type = PKT_PROBE;

src/net_setup.c

@@ -709,6 +709,7 @@ static bool setup_myself(void) {
 	myself->nexthop = myself;
 	myself->via = myself;
 	myself->status.reachable = true;
+	myself->status.sptps = experimental;
 	node_add(myself);
 
 	graph();

src/node.h

@@ -34,7 +34,8 @@ typedef struct node_status_t {
 	unsigned int visited:1;			/* 1 if this node has been visited by one of the graph algorithms */
 	unsigned int reachable:1;		/* 1 if this node is reachable in the graph */
 	unsigned int indirect:1;		/* 1 if this node is not directly reachable by us */
-	unsigned int unused:26;
+	unsigned int sptps:1;                   /* 1 if this node supports SPTPS */
+	unsigned int unused:25;
 } node_status_t;
 
 typedef struct node_t {

src/protocol_auth.c

@@ -506,7 +506,7 @@ bool send_ack(connection_t *c) {
 
 	get_config_int(lookup_config(c->config_tree, "Weight"), &c->estimated_weight);
 
-	return send_request(c, "%d %s %d %x", ACK, myport, c->estimated_weight, (c->options & 0xffffff) | (PROT_MINOR << 24));
+	return send_request(c, "%d %s %d %x", ACK, myport, c->estimated_weight, (c->options & 0xffffff) | (experimental ? (PROT_MINOR << 24) : 0));
 }
 
 static void send_everything(connection_t *c) {

src/protocol_key.c

@@ -47,7 +47,7 @@ void send_key_changed(void) {
 	for(node = connection_tree->head; node; node = node->next) {
 		c = node->data;
 		if(c->status.active && c->node && c->node->status.reachable) {
-			if(!experimental || OPTION_VERSION(c->node->options) < 2)
+			if(!c->node->status.sptps)
 				send_ans_key(c->node);
 		}
 	}
@@ -57,7 +57,7 @@ void send_key_changed(void) {
 	if(experimental) {
 		for(node = node_tree->head; node; node = node->next) {
 			node_t *n = node->data;
-			if(n->status.reachable && n->status.validkey && OPTION_VERSION(n->options) >= 2)
+			if(n->status.reachable && n->status.validkey && n->status.sptps)
 				sptps_force_kex(&n->sptps);
 		}
 	}
@@ -84,7 +84,7 @@ bool key_changed_h(connection_t *c, const char *request) {
 		return true;
 	}
 
-	if(OPTION_VERSION(n->options) < 2) {
+	if(!n->status.sptps) {
 		n->status.validkey = false;
 		n->last_req_key = 0;
 	}
@@ -106,7 +106,7 @@ static bool send_initial_sptps_data(void *handle, uint8_t type, const char *data
 }
 
 bool send_req_key(node_t *to) {
-	if(experimental && OPTION_VERSION(to->options) >= 2) {
+	if(to->status.sptps) {
 		if(!node_read_ecdsa_public_key(to)) {
 			logger(DEBUG_ALWAYS, LOG_DEBUG, "No ECDSA key known for %s (%s)", to->name, to->hostname);
 			send_request(to->nexthop->connection, "%d %s %s %d", REQ_KEY, myself->name, to->name, REQ_PUBKEY);
@@ -213,10 +213,12 @@ bool req_key_h(connection_t *c, const char *request) {
 
 	/* Check if this key request is for us */
 
-	if(to == myself) {			/* Yes, send our own key back */
+	if(to == myself) {			/* Yes */
+		/* Is this an extended REQ_KEY message? */
 		if(experimental && reqno)
 			return req_key_ext_h(c, request, from, reqno);
 
+		/* No, just send our key back */
 		send_ans_key(from);
 	} else {
 		if(tunnelserver)
@@ -235,7 +237,7 @@ bool req_key_h(connection_t *c, const char *request) {
 }
 
 bool send_ans_key(node_t *to) {
-	if(experimental && OPTION_VERSION(to->options) >= 2)
+	if(to->status.sptps)
 		abort();
 
 	size_t keylen = cipher_keylength(&myself->incipher);
@@ -329,7 +331,7 @@ bool ans_key_h(connection_t *c, const char *request) {
 
 	/* SPTPS or old-style key exchange? */
 
-	if(experimental && OPTION_VERSION(from->options) >= 2) {
+	if(from->status.sptps) {
 		char buf[strlen(key)];
 		int len = b64decode(key, buf, strlen(key));