--- badi/public_scripts/switchgate/switchgate	2009/04/24 00:12:49	1.1.1.1
+++ badi/public_scripts/switchgate/switchgate	2009/12/17 11:44:47	1.3
@@ -16,6 +16,10 @@ CONFIG_PATH="/etc/switchgate"
 # the dhclient-exit-hook helper program
 DHCP_TMP_DIR=/tmp/switchgate
 
+# eMail address to send alert messages, if not operating on the
+# standard default gateway
+ALERT_EMAIL="adi@ente.limmat.ch"
+
 # Host set to ping. A file containing IP addresses, each on a single line.
 # Do not include any local hosts, list only hosts located behind your gateways.
 HOSTSET_FILE="$CONFIG_PATH/hostset"
@@ -24,7 +28,7 @@ HOSTSET_FILE="$CONFIG_PATH/hostset"
 GATEWAYS_FILE="$CONFIG_PATH/gateways"
 
 # path to fping
-PING=/usr/sbin/fping
+PING=/usr/bin/fping
 
 # answer of fping to reachable hosts
 ALIVE_ANSWER="is alive"
@@ -81,7 +85,7 @@ function readgwlist {
 			unset alldhcpgates
 		done
 	fi
-	
+
 	if [ "$number_of_gws" -eq 0 ]; then
 		echo "No gateways configured. Please edit $GATEWAYS_FILE."
 		exit 1
@@ -117,7 +121,7 @@ function checkconnection {
    if [ -n "$DEBUG" ]; then
       if [ -n "$UP" ]; then
          echo "The connection is up."
-      else 
+      else
          echo "The connection is down."
       fi
    fi
@@ -130,7 +134,7 @@ function checkgw {
          echo "$NEWGW is reachable."
       fi
     else
-      if [ -n "$DEBUG" ]; then 
+      if [ -n "$DEBUG" ]; then
           echo "$NEWGW is not reachable."
       fi
       NEWGW=""
@@ -144,7 +148,7 @@ function getcurrentgw {
       exit 1
    else
       iproute_default_gw_txt="$(echo "$iproute_default_gw_txt" | grep "default via")"
-   fi  
+   fi
    if [ -z "$iproute_default_gw_txt" ]; then
       # no default gateway currently set, set to the highest index, to land on GW0
       CURRENTGW_ID=0
@@ -153,8 +157,8 @@ function getcurrentgw {
       echo "No default gateway currently set. Setting it now to $CURRENTGW."
       ip route add default via $CURRENTGW
    else
-      CURRENTGW=`echo $iproute_default_gw_txt | sed "s/^default via \(\([0-9]\+\.\?\)\{4\}\).*\$/\1/"` 
-      CURRENTGW_DEV=`echo $iproute_default_gw_txt | sed "s/^default via .* dev \(eth[0-9]\+\).*\$/\1/"` 
+      CURRENTGW=`echo $iproute_default_gw_txt | sed "s/^default via \(\([0-9]\+\.\?\)\{4\}\).*\$/\1/"`
+      CURRENTGW_DEV=`echo $iproute_default_gw_txt | sed "s/^default via .* dev \(eth[0-9]\+\).*\$/\1/"`
    fi
 
    # get index of current gateway
@@ -228,8 +232,8 @@ function switchgw {
    if [ -n "$NEWGW" ]; then
       if [ "$DEBUG" = "low" ]; then
          echo -n "Switching default gateway now to $NEWGW ($NEWGW_ID)..."
-      fi 
-      
+      fi
+
       iproute_msg="$(ip route change default via $NEWGW 2>&1 )"
       iproute_exit=$?
 
@@ -237,7 +241,7 @@ function switchgw {
       sleep 1
       GARBAGE=`$PING -q -c 5 -t100 -p50 -A -f $HOSTSET_FILE 2> /dev/null`
       sleep 1
-      
+
       if [ "$DEBUG" = "low" ]; then
          echo "done."
       fi
@@ -287,6 +291,12 @@ if [ "$1" = "-d" ]; then
 	fi 
 fi
 
+# Check fping existence
+if [ ! -x "$PING" ]; then
+	echo -e "Error: Ping program not executable or not found at $PING.\nPlease configure the full path in $0."
+	exit 1
+fi
+
 # Get all gateways, we can forward traffic
 readgwlist
 
@@ -317,13 +327,13 @@ if [ -z "$UP" ]; then
    checkgw
    if [ -z "$NEWGW" ]; then
       echo "Gateway $CURRENTGW is down."
-   else 
+   else
       echo "No connection through gateway $CURRENTGW." 
    fi
-  
+
    NEWGW_ID=$CURRENTGW_ID
    switchgw
-   
+
 else
    # If the current gateway is not the standard default gateway, try if the connection 
    # through the standard default gateway is back
@@ -341,6 +351,23 @@ else
    fi
 fi
 
+# send an eMail if the connection is down or limited
+if [ -z "$UP" ]; then
+	EMAIL_BODY="Switchgate on $(hostname -f) reports: No connection!\n\n\nTime:\t\t$(date)\nGateway:\t$CURRENTGW ($CURRENTGW_ID)"
+	EMAIL_SUBJECT="Attention: $(hostname -f) has no connection!"
+	echo -e "$EMAIL_BODY" | mail -s "$EMAIL_SUBJECT" "$ALERT_EMAIL"
+	if [[ -n "$DEBUG" && "$DEBUG" != "low" ]]; then
+		echo "Alert message sent to $ALERT_EMAIL."
+	fi
+elif [ "$CURRENTGW_ID" != 0 ]; then
+	EMAIL_BODY="Switchgate on $(hostname -f) reports: Not operating on standard default gateway!\n\n\nTime:\t\t$(date)\nGateway:\t$CURRENTGW ($CURRENTGW_ID)"
+	EMAIL_SUBJECT="Attention: $(hostname -f) Not operating on standard default gateway!"
+	echo -e "$EMAIL_BODY" | mail -s "$EMAIL_SUBJECT" "$ALERT_EMAIL"
+	if [[ -n "$DEBUG" && "$DEBUG" != "low" ]]; then
+		echo "Alert message sent to $ALERT_EMAIL."
+	fi
+fi
+
 if [ "$DEBUG" = "low" ]; then
    echo
    echo "Default Gateway: $CURRENTGW ($CURRENTGW_ID)"