From 77bd80fbbd4b874770da1f9060f7246ea6b40890 Mon Sep 17 00:00:00 2001
From: octeep <github@bandersnatch.anonaddy.com>
Date: Wed, 30 Mar 2022 18:27:52 +0100
Subject: [PATCH] add configtest flag

---
 README.md             |  9 ++++++---
 cmd/wireproxy/main.go | 18 ++++++++++++------
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/README.md b/README.md
index deef06e..12583f6 100644
--- a/README.md
+++ b/README.md
@@ -27,14 +27,17 @@ anything.
 
 ```
 usage: wireproxy [-h|--help] -c|--config "<value>" [-d|--daemon]
+                 [-n|--configtest]
 
                  Userspace wireguard client for proxying
 
 Arguments:
 
-  -h  --help    Print help information
-  -c  --config  Path of configuration file
-  -d  --daemon  Make wireproxy run in background
+  -h  --help        Print help information
+  -c  --config      Path of configuration file
+  -d  --daemon      Make wireproxy run in background
+  -n  --configtest  Configtest mode. Only check the configuration file for
+                    validity.
 ```
 
 # Sample config file
diff --git a/cmd/wireproxy/main.go b/cmd/wireproxy/main.go
index d56d33f..c668e9d 100644
--- a/cmd/wireproxy/main.go
+++ b/cmd/wireproxy/main.go
@@ -13,7 +13,7 @@ import (
 const daemonProcess = "daemon-process"
 
 func main() {
-	isDaemonProcess := os.Args[1] == daemonProcess
+	isDaemonProcess := len(os.Args) > 1 && os.Args[1] == daemonProcess
 	args := os.Args
 	if isDaemonProcess {
 		args = []string{args[0]}
@@ -24,6 +24,7 @@ func main() {
 
 	config := parser.String("c", "config", &argparse.Options{Required: true, Help: "Path of configuration file"})
 	daemon := parser.Flag("d", "daemon", &argparse.Options{Help: "Make wireproxy run in background"})
+	configTest := parser.Flag("n", "configtest", &argparse.Options{Help: "Configtest mode. Only check the configuration file for validity."})
 
 	err := parser.Parse(args)
 	if err != nil {
@@ -31,6 +32,16 @@ func main() {
 		return
 	}
 
+	conf, err := wireproxy.ParseConfig(*config)
+	if err != nil {
+		log.Panic(err)
+	}
+
+	if *configTest {
+		fmt.Println("Config OK")
+		return
+	}
+
 	if isDaemonProcess {
 		os.Stdout, _ = os.Open(os.DevNull)
 		os.Stderr, _ = os.Open(os.DevNull)
@@ -53,11 +64,6 @@ func main() {
 		return
 	}
 
-	conf, err := wireproxy.ParseConfig(*config)
-	if err != nil {
-		log.Panic(err)
-	}
-
 	tnet, err := wireproxy.StartWireguard(conf.Device)
 	if err != nil {
 		log.Panic(err)