1 files changed, 43 insertions, 0 deletions
diff --git a/contrib/examples/wg-config/tungate b/contrib/examples/wg-config/tungate
new file mode 100755
index 0000000..b537b81
--- /dev/null
+++ b/contrib/examples/wg-config/tungate
@@ -0,0 +1,43 @@
+#!/bin/bash
+
+unwind() {
+	ip route del "$1/32" 2>/dev/null
+	exit
+}
+
+short_route() {
+	ip route | sed -n "s/$1 \\(.* dev [^ ]\\+\\).*/\\1/p" | head -n 1
+}
+
+resolve_ip() {
+	local filter='/^[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}$/{p;q;}'
+	[[ $(sed -n "$filter" <<<"$1") == "$1" ]] && echo "$1" ||
+		host -t a "$1" | cut -d ' ' -f 4 | sed -n "$filter"
+}
+
+set_route() {
+	local default_route="$(short_route default)"
+	[[ -n $default_route ]] || { echo "[-] Could not determine default route"; return; }
+	echo "[+] Adding route for $1 to be $default_route"
+	ip route del "$1/32" 2>/dev/null
+	ip route add "$1/32" $default_route
+}
+
+check_loop() {
+	local ip="$(resolve_ip "$1")"
+	[[ -n $ip ]] || { echo "[-] Could not determine IP of '$1'" && return 1; }
+	echo "[+] Making sure $ip goes over the default (non-0/1,128/1) route"
+
+	set_route "$ip"
+	trap unwind INT TERM EXIT
+
+	while read; do
+		[[ $(short_route "$ip") != "$(short_route default)" ]] && set_route "$ip"
+	done < <(exec ip monitor route)
+}
+
+[[ $# -ne 1 ]] && { echo "Usage: $0 IP|HOST" >&2; exit 1; }
+[[ $UID -ne 0 ]] && exec sudo "$(readlink -f "$0")" "$@"
+
+check_loop "$1"
+exit $?