From d77ba5e1e872c0d9612d57f9ea59aed644c4ffed Mon Sep 17 00:00:00 2001
From: Dave Burke <dburke84@gmail.com>
Date: Sat, 28 May 2016 21:36:02 -0500
Subject: [PATCH] Combine user args with generated args

Generated arguments will be added only if matching arguments were not
specified by the user. User arguments will be placed after generated
arguments. This allows the user to override any generated configuration
values.
---
 bin/ovpn_run | 36 ++++++++++++++++++++++++++++--------
 1 file changed, 28 insertions(+), 8 deletions(-)

diff --git a/bin/ovpn_run b/bin/ovpn_run
index f848780..7ba16b1 100755
--- a/bin/ovpn_run
+++ b/bin/ovpn_run
@@ -13,7 +13,29 @@ set -e
 cd $OPENVPN
 
 # Build runtime arguments array based on environment
-ARGS=("--config" "$OPENVPN/openvpn.conf")
+USER_ARGS=("${@}")
+ARGS=()
+
+# Checks if ARGS already contains the given value
+function hasArg {
+    local element
+    for element in "${@:2}"; do
+        [ "${element}" == "${1}" ] && return 0
+    done
+    return 1
+}
+
+# Adds the given argument if it's not already specified.
+function addArg {
+    local arg="${1}"
+    [ $# -ge 1 ] && local val="${2}"
+    if ! hasArg "${arg}" "${USER_ARGS[@]}"; then
+        ARGS+=("${arg}")
+        [ $# -ge 1 ] && ARGS+=("${val}")
+    fi
+}
+
+addArg "--config" "$OPENVPN/openvpn.conf"
 
 source "$OPENVPN/ovpn_env.sh"
 
@@ -23,7 +45,7 @@ if [ ! -c /dev/net/tun ]; then
 fi
 
 if [ -d "$OPENVPN/ccd" ]; then
-    ARGS+=("--client-config-dir" "$OPENVPN/ccd")
+    addArg "--client-config-dir" "$OPENVPN/ccd"
 fi
 
 # When using --net=host, use this to specify nat device.
@@ -48,7 +70,7 @@ if [ -r "$EASYRSA_PKI/crl.pem" ]; then
         ln "$EASYRSA_PKI/crl.pem" "$OPENVPN/crl.pem"
         chmod 644 "$OPENVPN/crl.pem"
     fi
-    ARGS+=("--crl-verify" "$OPENVPN/crl.pem")
+    addArg "--crl-verify" "$OPENVPN/crl.pem"
 fi
 
 ip -6 route show default 2>/dev/null
@@ -61,8 +83,6 @@ if [ $? = 0 ]; then
     sysctl -w net.ipv6.conf.all.forwarding=1 || echo "Failed to enable IPv6 Forwarding"
 fi
 
-if [ "$#" -gt 0 ]; then
-    exec openvpn "$@"
-else
-    exec openvpn ${ARGS[@]}
-fi
+echo "Running 'openvpn ${ARGS[@]} ${USER_ARGS[@]}'"
+exec openvpn ${ARGS[@]} ${USER_ARGS[@]}
+