bug fix port forward

SSH-VPN-VNC/connect2jet.sh

 #!/bin/bash
 # By Michael Blaschek
 # Date 18.01.2021
-# CC BY 4.0 International  
+# CC BY 4.0 International
 # University of Vienna, Austria
 
 # Description:
 # Connect to Jet via a gateway server
 
-help(){
-	cat << EOF
-$0 -g [gateway] -p [port] user@remote
+help() {
+	cat <<EOF
+$0 -g [gateway] -p [port] -r [remote-port] user@remote
 Options:
-  -g [gateway]		gateway server, e.g. user@login.univie.ac.at
-  -p [port]			port to forward from jet to local, egv VNC port
+  -g [gateway]      gateway server, e.g. user@login.univie.ac.at
+  -p [port]         port to forward from jet to local, egv VNC port
+  -r [port]        remote port if not the same as port
   
 Example:
    $0 -g [U:Account-Username]@login.univie.ac.at [Jet-Username]@jet01.img.univie.ac.at
@@ -20,15 +21,18 @@ Example:
 EOF
 }
 
-while getopts "g:p:h" flag;
-do
-    case "${flag}" in
-        g ) gateway=${OPTARG}; ;;
-        p ) port=${OPTARG}; ;;
-        h|* ) help; exit 0;;
-    esac
+while getopts "g:p:r:h" flag; do
+	case "${flag}" in
+	g) gateway=${OPTARG} ;;
+	p) port=${OPTARG} ;;
+	r) rport=${OPTARG} ;;
+	h | *)
+		help
+		exit 0
+		;;
+	esac
 done
-shift $((OPTIND-1))
+shift $((OPTIND - 1))
 command=""
 remote=$1
 script=$(basename $0)
@@ -40,25 +44,56 @@ if [ "${remote}" == "" ]; then
 fi
 
 if [ -n "${port}" ]; then
-	echo "Forwarding Port: $port"
-	command="-L ${port}:localhost:${port} "
+	# -L local_port:destination_server_ip:remote_port
+	if [ -n "${rport}" ]; then
+		echo "Forwarding Port: $rport to $port"
+		command="-L ${port}:localhost:${rport} "
+	else
+		echo "Forwarding Port: $port to $port"
+		command="-L ${port}:localhost:${port} "
+		rport=$port # make sure we use this
+	fi
+
+fi
+
+# Check if names are in .ssh/config
+remote_status=false
+gateway_status=false
+if [ -e $HOME/.ssh/config ]; then
+	# check if hosts are there
+	cat $HOME/.ssh/config | grep -i 'Host ${remote}' > /dev/null
+	if [ $? -eq 0 ]; then
+		remote_status=true
+	fi
+	if [ -n ${gateway} ]; then
+		cat $HOME/.ssh/config | grep -i 'Host ${gateway}' > /dev/null
+		if [ $? -eq 0 ]; then
+			gateway_status=true
+		fi
+	fi
 fi
 
 if [ -n "${gateway}" ]; then
-	echo "$gateway" | grep '@' > /dev/null
-	if [ $? -eq 1 ]; then
-		echo "Please give: [user]@[server], not $gateway"
-		exit 1
+	echo "$gateway" | grep '@' >/dev/null
+	if [ $? -eq 1 ] && [ ! $gateway_status ]; then
+		echo "Could fail if not: [user]@[server], trying: $gateway"
+	fi
+	if [ -n "${port}" ]; then
+		echo "Using gateway: $gateway to $remote "
+		echo "Port Forwarding via the gateway: "
+		ssh -L ${port}:localhost:${port} -t $gateway ssh -L ${port}:${gateway}:${rport} ${remote}
+		echo "$(date) | ssh -L $port:localhost:12345 -t $gateway 'ssh -L 12345:${gateway}:${rport} ${remote}'" >>.${script/.sh/.log}
 	else
 		echo "Using gateway: $gateway to $remote "
-		ssh $command -t $gateway 'ssh ${command} ${remote}'
-		echo "$(date) | ssh $command -t $gateway 'ssh ${command} ${remote}'" >> .${script/.sh/.log}		
+		ssh $command -t $gateway ssh ${command} ${remote}
+		echo "$(date) | ssh $command -t $gateway 'ssh ${command} ${remote}'" >>.${script/.sh/.log}
 	fi
 else
+	if [ ! $remote_status ] ; then
+		echo "Could fail if not: [user]@[server]"
+	fi
 	echo "Direct connection to: ${remote}"
 	ssh ${command} ${remote}
-	echo "$(date) | ssh ${command} ${remote}" >> .${script/.sh/.log}
+	echo "$(date) | ssh ${command} ${remote}" >>.${script/.sh/.log}
 fi
-echo "Command Log in  .${script/.sh/.log}"
-
-
+echo "Command Log in  .${script/.sh/.log}"
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