Fix for revproxy; adding simple-web script.

Admin/Makefile

@@ -1,4 +1,4 @@
-LIST=arch-update clean-exim clean-exim-input close-guest fix-sound log-guest open-guest restart-service silent-guardian proxy
+LIST=arch-update clean-exim clean-exim-input close-guest fix-sound log-guest open-guest restart-service silent-guardian proxy simple-web
 LOCATION=/root/bin
 PERMISSION=0700
 compile: 

Admin/revproxy

@@ -2,6 +2,10 @@
 
 # Establish iptables-based reverse proxy
 
+# Thanks to user55518 in http://unix.stackexchange.com/questions/111841/regular-expression-in-bash-to-validate-ip-address#111843
+re='^[1-2]\{0,1\}[0-9]\{0,1\}[0-9]\{1\}\.[1-2]\{0,1\}[0-9]\{0,1\}[0-9]\{1\}\.[1-2]\{0,1\}[0-9]\{0,1\}[0-9]\{1\}\.[1-2]\{0,1\}[0-9]\{0,1\}[0-9]\{1\}$'
+
+
 if [ ! -z "$1" ] && [ "$1" == "--reset" ]; then
     iptables -F -t nat
     exit $?
@@ -12,8 +16,8 @@ if [ ! -z "$1" ] && [ "$1" == "--list" ]; then
     exit $?
 fi
 
-if [ -z "$1" ] || [ -z "$2" ] || [ -z "$3" ]; then
-    printf "Usage: $0 localport remotehost remoteport [ --local ]\n"
+if [ -z "$1" ] || [ -z "$2" ] || ! (echo "$2" | grep -x "$re" &> /dev/null) || [ -z "$3" ]; then
+    printf "Usage: $0 localport remoteIP remoteport [ --local ]\n"
     printf "       $0 --reset\n"
     printf "       $0 --list\n"
     exit 1
@@ -22,9 +26,6 @@ fi
 # Tell the kernel to allow forwarding packets.
 echo 1 > /proc/sys/net/ipv4/ip_forward
 
-# Default forwarding rule
-iptables -t nat -A PREROUTING -p tcp -m tcp --dport "$1" -j DNAT --to-destination "$2":"$3"
-
 # Set up masquerading if not already done
 if [ `iptables -S -t nat | grep -c '\-A POSTROUTING -j MASQUERADE'` -ne 1 ]; then
     iptables -t nat -A POSTROUTING -j MASQUERADE;
@@ -33,4 +34,9 @@ fi
 # Handle local forwarding.
 if [ "$4" == "--local" ] || [ "$2" == "127.0.0.1" ]; then
     iptables -t nat -I OUTPUT -p tcp -o lo --dport "$1" -j REDIRECT --to-ports "$3"
+    iptables -t nat -A PREROUTING -p tcp --dport "$1" -j REDIRECT --to "$3"
+else  # Handle remote
+    iptables -t nat -A PREROUTING -p tcp -m tcp --dport "$1" -j DNAT --to-destination "$2":"$3"
 fi
+
+echo Done -- all traffic connecting to port "$1" will be redirected to "$2":"$3"

Admin/simple-web

@@ -0,0 +1,2 @@
+#!/bin/bash
+python3 -m http.server 8000