Create check_routes.sh

wireguard/check_routes.sh

@@ -0,0 +1,95 @@
+#!/bin/bash
+
+INTERFACE=wg0
+METRIC=31
+TIMEOUT=180
+INTERVAL=2
+
+readarray -t ROUTES < <(echo "$WG_ROUTES" | tr , '\n')
+
+netenclose () {
+    local o1 o2 o3 o4 p1 p2 p3 p4 m1 m2 ip1 ip2 min
+    IFS=./ read o1 o2 o3 o4 m1 <<< "$1"
+    IFS=./ read p1 p2 p3 p4 m2 <<< "$2"
+
+    ((min = m1 > m2 ? m2 : m1))
+    ip1=$(((o1 << 24) + (o2 << 16) + (o3 << 8) + o4))
+    ip2=$(((p1 << 24) + (p2 << 16) + (p3 << 8) + p4))
+
+    if (( (ip1 >> (32 - min)) == (ip2 >> (32 - min)) )); then
+        if ((m1 > m2)); then
+            echo "$2"
+        else
+            echo "$1"
+        fi
+    else
+        echo "0.0.0.0/0"
+    fi
+}
+
+
+while true
+do
+  current_time=`date +%s`
+  readarray -t peers < <(wg show wg0 dump)
+  for peer in "${peers[@]}"
+  do
+   args=($(echo $peer))
+   public_key=${args[0]}
+   private_key=${args[1]}
+   endpoint=${args[2]}
+   route_list=${args[3]}
+   handshake=${args[4]}
+   bytes_recv=${args[5]}
+   bytes_sent=${args[6]}
+   keep_alive=${args[7]}
+
+   # If it's a remote peer, the private key should be '(none)'
+   # Otherwise, it's us
+   if [ "$private_key" != "(none)" ]; then
+    continue
+   fi
+    
+   # The following checks ensure this peer is reachable and set the 'up'
+   # flag accordingly
+   if [ "$endpoint" == "(none)" ]; then
+    up=false
+   elif [ "$handshake" == "0" ]; then
+    up=false
+   else
+    delta="$((current_time - handshake))"
+    if [ $delta -gt $TIMEOUT ]; then
+     up=false
+    else
+     up=true
+    fi
+   fi
+
+   readarray -t routes < <(echo "$route_list" | tr , '\n')
+   for route in "${routes[@]}"
+   do
+    in_network=false
+    for ROUTE in "${ROUTES[@]}"
+    do
+      parent_route=`netenclose $route $ROUTE`
+      if [ "$parent_route" == "$ROUTE" ]; then
+        in_network=true
+        break
+      fi
+    done
+    
+    # Only manipulate routes that are in the global WG_ROUTES variable
+    if [ $in_network == false ]; then
+      continue
+    fi
+    
+    if [ "$up" == "true" ]; then
+      ip route add $route dev $INTERFACE metric $METRIC 2> /dev/null && echo "Added route $route from peer $public_key ($endpoint)"
+    else
+      ip route delete $route dev $INTERFACE 2> /dev/null && echo "Removed route $route from peer $public_key"
+    fi
+   done
+
+  done
+  sleep $INTERVAL
+done