fix #322: add option general.find-process-mode, user can turn off findProcess feature in router

findProcess slow down connection due to repeat call to FindProcessName in router environment
this option has 3 values: always, strict, off
- always, equal to enable-process: true. Just try to merge all process related option into one
- strict, as default value, behavior remains unchanged
- off, turn off findProcess, useful in router environment

component/process/find_process_mode.go

@@ -0,0 +1,57 @@
+package process
+
+import (
+	"encoding/json"
+	"errors"
+	"strings"
+)
+
+const (
+	FindProcessAlways = "always"
+	FindProcessStrict = "strict"
+	FindProcessOff    = "off"
+)
+
+var (
+	validModes = map[string]struct{}{
+		FindProcessAlways: {},
+		FindProcessOff:    {},
+		FindProcessStrict: {},
+	}
+)
+
+type FindProcessMode string
+
+func (m FindProcessMode) Always() bool {
+	return m == FindProcessAlways
+}
+
+func (m FindProcessMode) Off() bool {
+	return m == FindProcessOff
+}
+
+func (m *FindProcessMode) UnmarshalYAML(unmarshal func(any) error) error {
+	var tp string
+	if err := unmarshal(&tp); err != nil {
+		return err
+	}
+	return m.Set(tp)
+}
+
+func (m *FindProcessMode) UnmarshalJSON(data []byte) error {
+	var tp string
+	if err := json.Unmarshal(data, &tp); err != nil {
+		return err
+	}
+	return m.Set(tp)
+}
+
+func (m *FindProcessMode) Set(value string) error {
+	mode := strings.ToLower(value)
+	_, exist := validModes[mode]
+	if !exist {
+		return errors.New("invalid find process mode")
+	}
+	*m = FindProcessMode(mode)
+	return nil
+}

config/config.go

@@ -4,6 +4,7 @@ import (
 	"container/list"
 	"errors"
 	"fmt"
+	P "github.com/Dreamacro/clash/component/process"
 	"net"
 	"net/netip"
 	"net/url"
@@ -52,6 +53,7 @@ type General struct {
 	GeodataLoader   string            `json:"geodata-loader"`
 	TCPConcurrent   bool              `json:"tcp-concurrent"`
 	EnableProcess   bool              `json:"enable-process"`
+	FindProcessMode P.FindProcessMode `json:"find-process-mode"`
 	Sniffing        bool              `json:"sniffing"`
 	EBpf            EBpf              `json:"-"`
 }
@@ -252,6 +254,7 @@ type RawConfig struct {
 	GeodataLoader         string            `yaml:"geodata-loader"`
 	TCPConcurrent         bool              `yaml:"tcp-concurrent" json:"tcp-concurrent"`
 	EnableProcess         bool              `yaml:"enable-process" json:"enable-process"`
+	FindProcessMode       P.FindProcessMode `yaml:"find-process-mode" json:"find-process-mode"`
 
 	Sniffer       RawSniffer                `yaml:"sniffer"`
 	ProxyProvider map[string]map[string]any `yaml:"proxy-providers"`
@@ -329,6 +332,7 @@ func UnmarshalRawConfig(buf []byte) (*RawConfig, error) {
 		ProxyGroup:      []map[string]any{},
 		TCPConcurrent:   false,
 		EnableProcess:   false,
+		FindProcessMode: P.FindProcessStrict,
 		Tun: RawTun{
 			Enable:              false,
 			Device:              "",
@@ -546,6 +550,7 @@ func parseGeneral(cfg *RawConfig) (*General, error) {
 		GeodataLoader:   cfg.GeodataLoader,
 		TCPConcurrent:   cfg.TCPConcurrent,
 		EnableProcess:   cfg.EnableProcess,
+		FindProcessMode: cfg.FindProcessMode,
 		EBpf:            cfg.EBpf,
 	}, nil
 }

hub/executor/executor.go

@@ -309,7 +309,7 @@ func updateTunnels(tunnels []LC.Tunnel) {
 
 func updateGeneral(general *config.General, force bool) {
 	tunnel.SetMode(general.Mode)
-	tunnel.SetAlwaysFindProcess(general.EnableProcess)
+	tunnel.SetFindProcessMode(general.EnableProcess, general.FindProcessMode)
 	dialer.DisableIPv6 = !general.IPv6
 	if !dialer.DisableIPv6 {
 		log.Infoln("Use IPv6")

tunnel/tunnel.go

@@ -43,7 +43,7 @@ var (
 	// default timeout for UDP session
 	udpTimeout = 60 * time.Second
 
-	alwaysFindProcess = false
+	findProcessMode P.FindProcessMode
 
 	fakeIPRange netip.Prefix
 )
@@ -146,9 +146,14 @@ func SetMode(m TunnelMode) {
 	mode = m
 }
 
-// SetAlwaysFindProcess set always find process info, may be increase many memory
-func SetAlwaysFindProcess(findProcess bool) {
-	alwaysFindProcess = findProcess
+// SetFindProcessMode replace SetAlwaysFindProcess
+// always find process info if legacyAlways = true or mode.Always() = true, may be increase many memory
+func SetFindProcessMode(legacyAlways bool, mode P.FindProcessMode) {
+	if legacyAlways {
+		findProcessMode = P.FindProcessAlways
+	} else {
+		findProcessMode = mode
+	}
 }
 
 // processUDP starts a loop to handle udp packet
@@ -463,7 +468,7 @@ func match(metadata *C.Metadata) (C.Proxy, C.Rule, error) {
 			}()
 		}
 
-		if !processFound && (alwaysFindProcess || rule.ShouldFindProcess()) {
+		if !findProcessMode.Off() && !processFound && (findProcessMode.Always() || rule.ShouldFindProcess()) {
 			srcPort, err := strconv.ParseUint(metadata.SrcPort, 10, 16)
 			uid, path, err := P.FindProcessName(metadata.NetWork.String(), metadata.SrcIP, int(srcPort))
 			if err != nil {