From: Etienne Dechamps <etienne@edechamps.fr>
Date: Mon, 18 May 2015 19:48:45 +0000 (+0100)
Subject: Don't parse node IDs if the sending node doesn't support them.
X-Git-Tag: release-1.1pre12~150
X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=commitdiff_plain;h=fef29d0193afc7e0a9dc766ef75b79cd4dc6fa37

Don't parse node IDs if the sending node doesn't support them.

Currently, tinc tries to parse node IDs for all SPTPS packets, including
ones sent from older, pre-node-IDs tinc-1.1 nodes, and therefore doesn't
recognize packets from these nodes. This commit fixes that.

It also makes code slightly clearer by reducing the amount of fiddling
around packet offset/length.
---

diff --git a/src/net_packet.c b/src/net_packet.c
index e169e2cd..4c060453 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -282,9 +282,8 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 			}
 			return false;
 		}
-		inpkt->offset += 2 * sizeof(node_id_t);
 		n->status.udppacket = true;
-		bool result = sptps_receive_data(&n->sptps, DATA(inpkt), inpkt->len - 2 * sizeof(node_id_t));
+		bool result = sptps_receive_data(&n->sptps, DATA(inpkt), inpkt->len);
 		n->status.udppacket = false;
 
 		if(!result) {
@@ -1440,10 +1439,16 @@ skip_harder:
 		return;
 	}
 
+	pkt.offset = 0;
+
 	if(n->status.sptps) {
-		pkt.offset = 2 * sizeof(node_id_t);
+		bool relay_enabled = (n->options >> 24) >= 4;
+		if (relay_enabled) {
+			pkt.offset = 2 * sizeof(node_id_t);
+			pkt.len -= pkt.offset;
+		}
 
-		if(!memcmp(DSTID(&pkt), &nullid, sizeof nullid)) {
+		if(!memcmp(DSTID(&pkt), &nullid, sizeof nullid) || !relay_enabled) {
 			direct = true;
 			from = n;
 			to = myself;
@@ -1468,7 +1473,7 @@ skip_harder:
 		/* If we're not the final recipient, relay the packet. */
 
 		if(to != myself) {
-			send_sptps_data(to, from, 0, DATA(&pkt), pkt.len - 2 * sizeof(node_id_t));
+			send_sptps_data(to, from, 0, DATA(&pkt), pkt.len);
 			try_tx_sptps(to, true);
 			return;
 		}
@@ -1477,7 +1482,6 @@ skip_harder:
 		from = n;
 	}
 
-	pkt.offset = 0;
 	if(!receive_udppacket(from, &pkt))
 		return;