sub: add custom subscription headers and enable gzip compression (#1289)

* sub: add support for custom subscription headers

* sub: gzip for subs

* sub: load and apply custom headers as middleware in initRouter

* sub: move header parsing to sub.go, empty default, validate header names and values

---------

Co-authored-by: Alireza Ahmadi <alireza7@gmail.com>

frontend

@@ -1 +1 @@
-Subproject commit e4525297b002c1c3be234cc1c9695ef84be741a0
+Subproject commit 80de052a45835b2edb1110ce83e2a947555138f1

go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/sagernet/sing-vmess v0.2.9-0.20260929152519-9b95ab8c9478
 	github.com/shirou/gopsutil/v4 v4.26.9
 	golang.org/x/crypto v0.57.0
+	golang.org/x/net v0.58.0
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20241231184526-a9ab2273dd10
 	gopkg.in/yaml.v3 v3.0.1
 	gorm.io/driver/sqlite v1.6.0
@@ -209,7 +210,6 @@ require (
 	golang.org/x/arch v0.29.0 // indirect
 	golang.org/x/exp v0.0.0-20260410095643-746e56fc9e2f // indirect
 	golang.org/x/mod v0.41.0 // indirect
-	golang.org/x/net v0.58.0 // indirect
 	golang.org/x/oauth2 v0.36.0 // indirect
 	golang.org/x/sync v0.23.0 // indirect
 	golang.org/x/sys v0.48.0 // indirect

service/setting.go

@@ -91,6 +91,7 @@ var defaultValueMap = map[string]string{
 	"subURI":             "",
 	"subJsonExt":         "",
 	"subClashExt":        "",
+	"subCustomHeaders":   "",
 	"subClashNoDefGrp":   "false",
 	"subClashSprtAll":    "false",
 	"subClashUdp":        "false",
@@ -540,6 +541,10 @@ func (s *SettingService) GetSubClashExt() (string, error) {
 	return s.getString("subClashExt")
 }
 
+func (s *SettingService) GetSubCustomHeaders() (string, error) {
+	return s.getString("subCustomHeaders")
+}
+
 // GetSubClashNoDefGrp reports whether the default "Proxy"/"Auto" proxy-groups
 // should never be injected into a Clash subscription. When true, the config is
 // left with exactly the groups the user defined.

sub/sub.go

@@ -7,6 +7,7 @@ import (
 	"net"
 	"net/http"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/alireza0/s-ui/config"
@@ -16,7 +17,9 @@ import (
 	"github.com/alireza0/s-ui/service"
 	"github.com/alireza0/s-ui/util/common"
 
+	"github.com/gin-contrib/gzip"
 	"github.com/gin-gonic/gin"
+	"golang.org/x/net/http/httpguts"
 )
 
 type Server struct {
@@ -46,6 +49,20 @@ func (s *Server) initRouter() (*gin.Engine, error) {
 	}
 
 	engine := gin.Default()
+	engine.Use(gzip.Gzip(gzip.DefaultCompression))
+
+	customHeadersStr, err := s.SettingService.GetSubCustomHeaders()
+	if err != nil {
+		return nil, err
+	}
+	if customHeaders := parseCustomHeaders(customHeadersStr); len(customHeaders) > 0 {
+		engine.Use(func(c *gin.Context) {
+			for _, h := range customHeaders {
+				c.Writer.Header().Set(h.key, h.value)
+			}
+			c.Next()
+		})
+	}
 
 	subPath, err := s.SettingService.GetSubPath()
 	if err != nil {
@@ -67,6 +84,32 @@ func (s *Server) initRouter() (*gin.Engine, error) {
 	return engine, nil
 }
 
+type customHeader struct {
+	key   string
+	value string
+}
+
+func parseCustomHeaders(raw string) []customHeader {
+	var headers []customHeader
+	for _, line := range strings.Split(raw, "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" || strings.HasPrefix(line, "#") || strings.HasPrefix(line, "//") {
+			continue
+		}
+		key, value, ok := strings.Cut(line, ":")
+		if !ok {
+			continue
+		}
+		key = strings.TrimSpace(key)
+		value = strings.TrimSpace(value)
+		if value == "" || !httpguts.ValidHeaderFieldName(key) || !httpguts.ValidHeaderFieldValue(value) {
+			continue
+		}
+		headers = append(headers, customHeader{key: key, value: value})
+	}
+	return headers
+}
+
 func (s *Server) Start() (err error) {
 	//This is an anonymous function, no function name
 	defer func() {

sub/sub_test.go

@@ -0,0 +1,52 @@
+package sub
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestParseCustomHeaders(t *testing.T) {
+	testCases := []struct {
+		name string
+		in   string
+		want []customHeader
+	}{
+		{"empty string", "", nil},
+		{"whitespace only", "   \n\t  \r\n   ", nil},
+		{"comment", "# 424242", nil},
+		{
+			"extra spaces",
+			"\n\tannounce :  42! \n\tannounce-url: t.me/4242\n\t",
+			[]customHeader{{"announce", "42!"}, {"announce-url", "t.me/4242"}},
+		},
+		{
+			"values keep their colons",
+			"Profile-Web-Page-Url: https://sub.example.com:8443/login?redirect=https://a.com",
+			[]customHeader{{"Profile-Web-Page-Url", "https://sub.example.com:8443/login?redirect=https://a.com"}},
+		},
+		{
+			"crlf line endings and comments",
+			"# header 1\r\nX-Custom: value1\r\n// comment 2\r\nX-Other: value2\r\n",
+			[]customHeader{{"X-Custom", "value1"}, {"X-Other", "value2"}},
+		},
+		{
+			"malformed lines are skipped",
+			"random text without colon\n: missing key\nempty value: \n:\nvalid-key: ok\n",
+			[]customHeader{{"valid-key", "ok"}},
+		},
+		{
+			// A name an HTTP header cannot carry would go out malformed.
+			"invalid names are skipped",
+			"Bad Name: x\nBad(Name): x\nGood-Name: x\n",
+			[]customHeader{{"Good-Name", "x"}},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := parseCustomHeaders(tc.in); !reflect.DeepEqual(got, tc.want) {
+				t.Errorf("got %+v, want %+v", got, tc.want)
+			}
+		})
+	}
+}