From b20acf2cbeb55d305faece6fe9959a02e8913a3d Mon Sep 17 00:00:00 2001
From: SunBK201 <sunbk201gm@gmail.com>
Date: Sat, 29 Nov 2025 16:37:41 +0800
Subject: [PATCH] feat: add packet modification configuration with environment
 variables

---
 openwrt/files/ua3f.init                      |  9 +++------
 src/internal/config/config.go                | 14 +++++++++++++-
 src/internal/server/netlink/netlink_linux.go |  2 +-
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/openwrt/files/ua3f.init b/openwrt/files/ua3f.init
index b011e9a..d41d7cc 100755
--- a/openwrt/files/ua3f.init
+++ b/openwrt/files/ua3f.init
@@ -32,11 +32,6 @@ start_service() {
     config_get_bool set_ipid "main" "set_ipid" 0
     config_get_bool del_tcpts "main" "del_tcpts" 0
 
-    local others=","
-    [ "$set_ipid" -eq "1" ] && others="${others}ipid,"
-    [ "$del_tcpts" -eq "1" ] && others="${others}tcpts,"
-    [ "$set_ttl" -eq "1" ] && others="${others}ttl,"
-
     procd_open_instance "$NAME"
     procd_set_param command "$PROG"
     procd_append_param command -m "$server_mode"
@@ -47,8 +42,10 @@ start_service() {
     procd_append_param command -l "$log_level"
     procd_append_param command -x "$rewrite_mode"
     procd_append_param command -z "$rewrite_rules"
-    procd_append_param command -o "$others"
     [ "$partial_replace" = "1" ] && procd_append_param command -s
+    procd_append_param env UA3F_TTL="$set_ttl"
+    procd_append_param env UA3F_IPID="$set_ipid"
+    procd_append_param env UA3F_TCPTS="$del_tcpts"
 
     procd_set_param respawn
     procd_set_param stdout 1
diff --git a/src/internal/config/config.go b/src/internal/config/config.go
index 0f31163..7d6f8d4 100644
--- a/src/internal/config/config.go
+++ b/src/internal/config/config.go
@@ -4,6 +4,7 @@ import (
 	"flag"
 	"fmt"
 	"log/slog"
+	"os"
 	"strings"
 )
 
@@ -86,7 +87,18 @@ func Parse() (*Config, bool) {
 		cfg.ListenAddr = fmt.Sprintf("0.0.0.0:%d", port)
 	}
 
-	// Parse other options
+	// Parse other options from environment variables
+	if os.Getenv("UA3F_TCPTS") == "1" {
+		cfg.DelTCPTimestamp = true
+	}
+	if os.Getenv("UA3F_TTL") == "1" {
+		cfg.SetTTL = true
+	}
+	if os.Getenv("UA3F_IPID") == "1" {
+		cfg.SetIPID = true
+	}
+
+	// Parse other options from -o flag
 	opts := strings.Split(others, ",")
 	for _, opt := range opts {
 		switch strings.ToLower(strings.TrimSpace(opt)) {
diff --git a/src/internal/server/netlink/netlink_linux.go b/src/internal/server/netlink/netlink_linux.go
index c299713..fc62d80 100644
--- a/src/internal/server/netlink/netlink_linux.go
+++ b/src/internal/server/netlink/netlink_linux.go
@@ -45,8 +45,8 @@ func (s *Server) Start() (err error) {
 		slog.Error("s.Firewall.Setup", slog.Any("error", err))
 		return err
 	}
+	slog.Info("Packet modification configuration", slog.Bool("ttl", s.cfg.SetTTL), slog.Bool("tcpts", s.cfg.DelTCPTimestamp), slog.Bool("ipid", s.cfg.SetIPID))
 	if s.cfg.DelTCPTimestamp || s.cfg.SetIPID {
-		slog.Info("Packet modification features enabled")
 		return s.nfqServer.Start()
 	}
 	return nil