Add L3 routing support

route/rule_item_user_id.go

@@ -0,0 +1,52 @@
+package route
+
+import (
+	"strings"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/warning"
+	C "github.com/sagernet/sing-box/constant"
+	F "github.com/sagernet/sing/common/format"
+)
+
+var warnUserIDOnNonLinux = warning.New(
+	func() bool { return !C.IsLinux },
+	"rule item `user_id` is only supported on Linux",
+)
+
+var _ RuleItem = (*UserIdItem)(nil)
+
+type UserIdItem struct {
+	userIds   []int32
+	userIdMap map[int32]bool
+}
+
+func NewUserIDItem(userIdList []int32) *UserIdItem {
+	warnUserIDOnNonLinux.Check()
+	rule := &UserIdItem{
+		userIds:   userIdList,
+		userIdMap: make(map[int32]bool),
+	}
+	for _, userId := range userIdList {
+		rule.userIdMap[userId] = true
+	}
+	return rule
+}
+
+func (r *UserIdItem) Match(metadata *adapter.InboundContext) bool {
+	if metadata.ProcessInfo == nil || metadata.ProcessInfo.UserId == -1 {
+		return false
+	}
+	return r.userIdMap[metadata.ProcessInfo.UserId]
+}
+
+func (r *UserIdItem) String() string {
+	var description string
+	pLen := len(r.userIds)
+	if pLen == 1 {
+		description = "user_id=" + F.ToString(r.userIds[0])
+	} else {
+		description = "user_id=[" + strings.Join(F.MapToString(r.userIds), " ") + "]"
+	}
+	return description
+}