--- badi/public_scripts/switchgate/switchgate	2009/12/17 11:55:02	1.4
+++ badi/public_scripts/switchgate/switchgate	2010/01/09 04:25:42	1.5
@@ -36,7 +36,7 @@ ALIVE_ANSWER="is alive"
 # set to an empty string to avoid debug output
 # to "low" for a few output and to anything else
 # for verbose output
-DEBUG=
+DEBUG=low
 
 
 # -------- Do not edit below this line --------
@@ -47,6 +47,61 @@ PINGARGS="-A -p25 -t100"
 ## Function declarations
 #
 
+# parse commandline switches
+function parse_commandline {
+	
+	# check rest
+	while [ "$#" -gt 0 ]; do
+
+	   case "$1" in
+
+	   -d|--debug)
+   		# debug switch (another hidden feature)
+		shift
+		if [ "$1" != "low" ]; then
+			DEBUG="choke"
+			echo "Debug mode on."
+		else
+			#echo "Info mode on."
+			DEBUG="low"
+			shift
+		fi
+		;;
+
+	   -C)
+   		# Parse writeable dir request (hidden feature)
+		echo "$DHCP_TMP_DIR"
+		exit 0
+		;;
+
+	   -q|--query)
+		# Parse query for current gw  (yet another hidden feature)
+		shift
+		parse_commandline "$@"
+		getcurrentgw
+		echo "$CURRENTGW"
+		exit 0
+		;;
+
+	   -s|--set)
+   		# Set gateway to number n (yet another hidden feature)
+		shift
+		set_to_gw="$1"
+		shift
+		parse_commandline "$@"
+		set_gw
+		exit 0
+		;;
+
+	   *)
+		echo "Invalid argument \"$1\"."
+		exit 1
+		;;
+
+	   esac
+	done
+}
+
 # Read gateways from file
 function readgwlist {
 	if [ -f "$GATEWAYS_FILE" ]; then
@@ -141,6 +196,7 @@ function checkgw {
    fi
 }
 
+# Get the current default gateway (or set it, if there was none set) 
 function getcurrentgw {
    iproute_default_gw_txt="$(ip route show scope global)"
    if [ `echo $iproute_default_gw_txt | grep -c default` -gt 1 ]; then
@@ -153,13 +209,16 @@ function getcurrentgw {
       # no default gateway currently set, set to the highest index, to land on GW0
       CURRENTGW_ID=0
       CURRENTGW=${GW[$CURRENTGW_ID]}
-      CURRENTGW_DEV="unknown"
       echo "No default gateway currently set. Setting it now to $CURRENTGW."
       ip route add default via $CURRENTGW
+      if [ $? -eq 2 ]; then
+	echo "Not able to switch default gateway. Is your interface up?"
+	exit 1
+      fi
    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/"`
    fi
+   CURRENTGW_DEV=`echo $iproute_default_gw_txt | sed "s/^default via .* dev \(eth[0-9]\+\).*\$/\1/"`
 
    # get index of current gateway
    index=-1
@@ -201,7 +260,7 @@ function getnextgw {
 function getnewgw {
    getnextgw
    # Check wheter all gateways are already tested and failed
-   if [ "$NEWGW_ID" -eq "$CURRENTGW_ID" ]; then
+   if [[ "$NEWGW_ID" -eq "$CURRENTGW_ID" &&  -z $set_to_gw ]]; then
       if [ -n "$DEBUG" ]; then
          echo "All gateways tried."
       fi
@@ -227,6 +286,33 @@ function getnewgw {
    fi
 }
 
+# Switch the gateway to a desired gateway
+function set_gw {
+
+   # get name of gateway
+   if [[ ! "$set_to_gw" =~ ^[0-9]{1,}$ ]]; then
+	echo "Only positive numbers allowed. Invalid value \"$set_to_gw\"."
+	exit 1   
+   fi
+   
+   NEWGW=${GW[$set_to_gw]}
+   if [ -z "$NEWGW" ]; then
+      echo "The gateway number $set_to_gw is not in the list of available gateways."
+      echo "Valid gateways are:"
+      for ((gw=0; gw<${#GW[*]}; gw++)); do
+      	  echo -e "\t$gw (${GW[$gw]})"
+      done 
+      exit 1
+   fi
+   if [ -n "$DEBUG" -a "$DEBUG" != "low" ]; then
+      echo "Default gateway desired: $NEWGW ($set_to_gw)"
+   fi
+   
+   getcurrentgw
+   NEWGW_ID=$[ $set_to_gw - 1 ]
+   switchgw
+}
+
 function switchgw {
    getnewgw
    if [ -n "$NEWGW" ]; then
@@ -274,22 +360,6 @@ function switchgw {
 ## MAIN
 #
 
-# Parse writeable dir request (hidden feature)
-if [ "$1" = "-C" ]; then
-	echo "$DHCP_TMP_DIR"
-	exit 0
-fi
-
-# Parse debug switch (another hidden feature)
-if [ "$1" = "-d" ]; then
-	if [ "$2" != "low" ]; then
-		echo "Debug mode on."
-		DEBUG="choke"
-	else
-		#echo "Info mode on."
-		DEBUG="low"
-	fi 
-fi
 
 # Check fping existence
 if [ ! -x "$PING" ]; then
@@ -300,13 +370,8 @@ fi
 # Get all gateways, we can forward traffic
 readgwlist
 
-# Parse query for current gw  (yet another hidden feature)
-if [ "$1" = "-q" ]; then
-	DEBUG=
-	getcurrentgw
-	echo "$CURRENTGW"
-	exit 0
-fi
+# parse commandline switches
+parse_commandline "$@"
 
 # get current gw
 getcurrentgw