Merge pull request #9 from shadowy-pycoder/fixesfeatures

Support of `SO_MARK` in auto configuration

Author: shadowy-pycoder

README.md

@@ -97,7 +97,7 @@ You can download the binary for your platform from [Releases](https://github.com
 Example:
 
 ```shell
-HPTS_RELEASE=v1.8.1; wget -v https://github.com/shadowy-pycoder/go-http-proxy-to-socks/releases/download/$HPTS_RELEASE/gohpts-$HPTS_RELEASE-linux-amd64.tar.gz -O gohpts && tar xvzf gohpts && mv -f gohpts-$HPTS_RELEASE-linux-amd64 gohpts && ./gohpts -h
+HPTS_RELEASE=v1.8.2; wget -v https://github.com/shadowy-pycoder/go-http-proxy-to-socks/releases/download/$HPTS_RELEASE/gohpts-$HPTS_RELEASE-linux-amd64.tar.gz -O gohpts && tar xvzf gohpts && mv -f gohpts-$HPTS_RELEASE-linux-amd64 gohpts && ./gohpts -h
 ```
 
 Alternatively, you can install it using `go install` command (requires Go [1.24](https://go.dev/doc/install) or later):
@@ -159,6 +159,8 @@ Options:
         Address of HTTP proxy server (default "127.0.0.1:8080")
   -logfile string
         Log file path (Default: stdout)
+  -mark uint
+        Set the mark for each packet sent through transparent proxy
   -nocolor
         Disable colored output for logs (no effect if -j flag specified)
   -s string
@@ -387,6 +389,12 @@ sudo env PATH=$PATH gohpts -d -T 8888 -M redirect -auto
 
 Please note, automatic configuration requires `sudo` and is very generic, which might not be suitable for your needs.
 
+You can optionally specify `-mark <value>` to prevent possible proxy loops
+
+```shell
+sudo env PATH=$PATH gohpts -d -T 8888 -M redirect -auto -mark 100
+```
+
 ## `tproxy` (via _MANGLE_ and _IP_TRANSPARENT_)
 
 [[Back]](#table-of-contents)

cmd/gohpts/cli.go

@@ -55,6 +55,7 @@ func root(args []string) error {
 			return nil
 		})
 		flags.BoolVar(&conf.Auto, "auto", false, "Automatically setup iptables for transparent proxy (requires elevated privileges)")
+		flags.UintVar(&conf.Mark, "mark", 0, "Set the mark for each packet sent through transparent proxy")
 	}
 	flags.StringVar(&conf.LogFilePath, "logfile", "", "Log file path (Default: stdout)")
 	flags.BoolVar(&conf.Debug, "d", false, "Show logs in DEBUG mode")
@@ -110,6 +111,11 @@ func root(args []string) error {
 			return fmt.Errorf("-auto is available only for -M redirect")
 		}
 	}
+	if seen["mark"] {
+		if !seen["t"] && !seen["T"] {
+			return fmt.Errorf("-mark requires -t or -T flag")
+		}
+	}
 	if seen["f"] {
 		for _, da := range []string{"s", "u", "U", "c", "k", "l"} {
 			if seen[da] {