]> git.meshlink.io Git - meshlink/commitdiff
Make code to detect two nodes with the same Name less triggerhappy.
authorGuus Sliepen <guus@tinc-vpn.org>
Sat, 16 Jul 2011 08:47:35 +0000 (10:47 +0200)
committerGuus Sliepen <guus@tinc-vpn.org>
Sat, 16 Jul 2011 08:47:35 +0000 (10:47 +0200)
First of all, if there really are two nodes with the same name, much
more than 10 contradicting ADD_EDGE and DEL_EDGE messages will be sent.
Also, we forgot to reset the counters when nothing happened.

In case there is a ADD_EDGE/DEL_EDGE storm, we do not shut down, but
sleep an increasing amount of time, allowing tinc to recover gracefully
from temporary failures.

src/net.c

index c5193c5d67a3726213eac3c6971b712c674865bc..b3f924ad661232312427abf929aadc6b4af1e361 100644 (file)
--- a/src/net.c
+++ b/src/net.c
@@ -50,6 +50,7 @@ bool graph_dump = false;
 time_t now = 0;
 int contradicting_add_edge = 0;
 int contradicting_del_edge = 0;
+static int sleeptime = 10;
 
 /* Purge edges and subnets of unreachable nodes. Use carefully. */
 
@@ -464,18 +465,25 @@ int main_loop(void) {
                                keyexpires = now + keylifetime;
                        }
 
-                       if(contradicting_del_edge > 10 && contradicting_add_edge > 10) {
-                               logger(LOG_WARNING, "Possible node with same Name as us!");
-
-                               if(rand() % 3 == 0) {
-                                       logger(LOG_ERR, "Shutting down, check configuration of all nodes for duplicate Names!");
-                                       running = false;
-                                       break;
-                               }
-
-                               contradicting_add_edge = 0;
-                               contradicting_del_edge = 0;
+                       /* Detect ADD_EDGE/DEL_EDGE storms that are caused when
+                        * two tinc daemons with the same name are on the VPN.
+                        * If so, sleep a while. If this happens multiple times
+                        * in a row, sleep longer. */
+
+                       if(contradicting_del_edge > 100 && contradicting_add_edge > 100) {
+                               logger(LOG_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", sleeptime);
+                               sleep(sleeptime);
+                               sleeptime *= 2;
+                               if(sleeptime < 0)
+                                       sleeptime = 3600;
+                       } else {
+                               sleeptime /= 2;
+                               if(sleeptime < 10)
+                                       sleeptime = 10;
                        }
+
+                       contradicting_add_edge = 0;
+                       contradicting_del_edge = 0;
                }
 
                if(sigalrm) {