openvpn: add generic hotplug mechanism

Pass a default --up and --down executable to each started OpenVPN instance
which triggers /etc/hotplug.d/openvpn/ scripts whenever an instance
goes up or down.

User-configured up and down scripts are invoked by the default shipped
01-user hotplug handler to ensure that existing setups continue to work
as before.

As a consequence of this change, the up, down and script_security OpenVPN
options are removed from the option file, since we're always passing them
via the command line, they do not need to get included into the generated
configuration.

Signed-off-by: Florian Eckert <fe@dev.tdt.de>
[reword commit message, move hotplug executable to /usr/libexec]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>

1 files changed, 32 insertions, 0 deletions

diff --git a/package/network/services/openvpn/files/etc/hotplug.d/openvpn/01-user b/package/network/services/openvpn/files/etc/hotplug.d/openvpn/01-user
new file mode 100644
index 0000000000..6d45f0b7c6
--- /dev/null
+++ b/package/network/services/openvpn/files/etc/hotplug.d/openvpn/01-user
@@ -0,0 +1,32 @@
+#!/bin/sh
+
+get_option() {
+	local variable="$1"
+	local option="$2"
+
+	local value="$(sed -rne 's/^[ \t]*'"$option"'[ \t]+(([^ \t\\]|\\.)+)[ \t]*$/\1/p' "$config" | tail -n1 | sed -re 's/\\(.)/\1/g')"
+	[ -n "$value" ] || value="$(sed -rne 's/^[ \t]*'"$option"'[ \t]+'"'([^']+)'"'[ \t]*$/\1/p' "$config" | tail -n1)"
+	[ -n "$value" ] || value="$(sed -rne 's/^[ \t]*'"$option"'[ \t]+"(([^"\\]|\\.)+)"[ \t]*$/\1/p' "$config" | tail -n1 | sed -re 's/\\(.)/\1/g')"
+	[ -n "$value" ] || return 1
+
+	export -n "$variable=$value"
+	return 0
+}
+
+[ -e "/etc/openvpn.user" ] && {
+	env -i ACTION="$ACTION" INSTANCE="$INSTANCE" \
+		/bin/sh \
+		/etc/openvpn.user \
+		$*
+}
+
+# Wrap user defined scripts on up/down events
+case "$ACTION" in
+	up|down)
+		if get_option command "$ACTION"; then
+			exec /bin/sh -c "$command $ACTION $INSTANCE $*"
+		fi
+	;;
+esac
+
+exit 0