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 e169e2c..4c06045 100644 (file)
--- 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;