fastd MTU-problem-prober

S99z-fastd-MTU-problem-prober

#!/bin/sh
#place in /etc/rc.d/S99z-fastd-MTU-problem-prober
BIGPROBESIZE=1492
GWA=draco.fftr
GWAuciPath=fastd.mesh_vpn_backbone_peer_draco.remote
GWB=elmira.fftr
GWBuciPath=fastd.mesh_vpn_backbone_peer_elmira.remote

waitForNet() {
   while !ping -6 -c 10 $GWA && !ping -6 -c 10 $GWB; do
      echo "Gateways do not ping at all, sleeping 1 minute"
      sleep 60
   done
}

checkConnection() { 
   if ping -6 -c 10 -s $BIGPROBESIZE $GWA || ping -6 -c 10 -s $BIGPROBESIZE $GWB; then
      echo "big testping sucessfully, fastd is configured correctly, exiting."
      uci commit fastd
      exit
   fi
}

setRemotes() {
   echo "Old remotes:"
   GWAremote="$(uci get $GWAuciPath)"
   echo "$GWAremote"
   GWAremote="$(echo "$GWAremote" | sed -E 's/^ipv6 ?//g;s/^ipv4 ?//g;')"

   GWBremote="$(uci get $GWBuciPath)"
   echo "$GWBremote"
   GWBremote="$(echo "$GWBremote" | sed -E 's/^ipv6 ?//g;s/^ipv4 ?//g;')"

   echo "deleting old remotes"
   uci delete "$GWAuciPath"
   uci delete "$GWBuciPath"

   echo "adding new remotes"
   GWAremote="${1}$GWAremote"
   echo "$GWAremote"
   uci add_list "$GWAuciPath=$GWAremote"

   GWBremote="${1}$GWBremote"
   echo "$GWBremote"
   uci add_list "$GWBuciPath=$GWBremote"
}

restartFastd() {
   /etc/init.d/fastd stop;
   /etc/init.d/fastd start
}

sleep 600 #give the box time to boot

{
   #try current configuration
   waitForNet
   checkConnection

   #try ipv6 ony
   setRemotes "ipv6 "
   restartFastd
   waitForNet
   checkConnection

   #try ipv4 ony
   setRemotes "ipv4 "
   restartFastd
   waitForNet
   checkConnection

   #try dualstack
   setRemotes ""
   restartFastd
   waitForNet
   checkConnection

   #ok, we did not find anything working. we will not commit anything causing no permanent change
} 2>&1 | logger -s -t S99z-fastd-MTU-problem-prober #logg all output to syslog, too