warning: put into main

1 files changed, 41 insertions, 4 deletions

diff --git a/main.go b/main.go
index 4b8299a..41231bf 100644
--- a/main.go
+++ b/main.go
@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"os"
 	"os/signal"
+	"runtime"
 	"strconv"
 )
 
@@ -18,8 +19,8 @@ const (
 )
 
 const (
-	ENV_WG_TUN_FD  = "WG_TUN_FD"
-	ENV_WG_UAPI_FD = "WG_UAPI_FD"
+	ENV_WG_TUN_FD             = "WG_TUN_FD"
+	ENV_WG_UAPI_FD            = "WG_UAPI_FD"
 	ENV_WG_PROCESS_FOREGROUND = "WG_PROCESS_FOREGROUND"
 )
 
@@ -28,9 +29,45 @@ func printUsage() {
 	fmt.Printf("%s [-f/--foreground] INTERFACE-NAME\n", os.Args[0])
 }
 
-func main() {
+func warning() {
+	shouldQuit := false
+
+	fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
+	fmt.Fprintln(os.Stderr, "W                                                     G")
+	fmt.Fprintln(os.Stderr, "W   This is alpha software. It will very likely not   G")
+	fmt.Fprintln(os.Stderr, "W   do what it is supposed to do, and things may go   G")
+	fmt.Fprintln(os.Stderr, "W   horribly wrong. You have been warned. Proceed     G")
+	fmt.Fprintln(os.Stderr, "W   at your own risk.                                 G")
+	if runtime.GOOS == "linux" {
+		shouldQuit = os.Getenv("WG_I_PREFER_BUGGY_USERSPACE_TO_POLISHED_KMOD") != "1"
+
+		fmt.Fprintln(os.Stderr, "W                                                     G")
+		fmt.Fprintln(os.Stderr, "W   Furthermore, you are running this software on a   G")
+		fmt.Fprintln(os.Stderr, "W   Linux kernel, which is probably unnecessary and   G")
+		fmt.Fprintln(os.Stderr, "W   foolish. This is because the Linux kernel has     G")
+		fmt.Fprintln(os.Stderr, "W   built-in first class support for WireGuard, and   G")
+		fmt.Fprintln(os.Stderr, "W   this support is much more refined than this       G")
+		fmt.Fprintln(os.Stderr, "W   program. For more information on installing the   G")
+		fmt.Fprintln(os.Stderr, "W   kernel module, please visit:                      G")
+		fmt.Fprintln(os.Stderr, "W           https://www.wireguard.com/install         G")
+		if shouldQuit {
+			fmt.Fprintln(os.Stderr, "W                                                     G")
+			fmt.Fprintln(os.Stderr, "W   If you still want to use this program, against    G")
+			fmt.Fprintln(os.Stderr, "W   the sage advice here, please first export this    G")
+			fmt.Fprintln(os.Stderr, "W   environment variable:                             G")
+			fmt.Fprintln(os.Stderr, "W   WG_I_PREFER_BUGGY_USERSPACE_TO_POLISHED_KMOD=1    G")
+		}
+	}
+	fmt.Fprintln(os.Stderr, "W                                                     G")
+	fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
 
-	Warning()
+	if shouldQuit {
+		os.Exit(1)
+	}
+}
+
+func main() {
+	warning()
 
 	// parse arguments