Root config: Add version config (min and max) (#4970)

https://github.com/XTLS/Xray-core/pull/4968#issuecomment-3146592323

app/version/version.go

@@ -0,0 +1,77 @@
+package version
+
+import (
+	"context"
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/errors"
+	"strconv"
+	"strings"
+)
+
+type Version struct {
+	config *Config
+	ctx    context.Context
+}
+
+func New(ctx context.Context, config *Config) (*Version, error) {
+	if config.MinVersion != "" {
+		result, err := compareVersions(config.MinVersion, config.CoreVersion)
+		if err != nil {
+			return nil, err
+		}
+		if result > 0 {
+			return nil, errors.New("this config must be run on version ", config.MinVersion, " or higher")
+		}
+	}
+	if config.MaxVersion != "" {
+		result, err := compareVersions(config.MaxVersion, config.CoreVersion)
+		if err != nil {
+			return nil, err
+		}
+		if result < 0 {
+			return nil, errors.New("this config should be run on version ", config.MaxVersion, " or lower")
+		}
+	}
+	return &Version{config: config, ctx: ctx}, nil
+}
+
+func compareVersions(v1, v2 string) (int, error) {
+	// Split version strings into components
+	v1Parts := strings.Split(v1, ".")
+	v2Parts := strings.Split(v2, ".")
+
+	// Pad shorter versions with zeros
+	for len(v1Parts) < len(v2Parts) {
+		v1Parts = append(v1Parts, "0")
+	}
+	for len(v2Parts) < len(v1Parts) {
+		v2Parts = append(v2Parts, "0")
+	}
+
+	// Compare each part
+	for i := 0; i < len(v1Parts); i++ {
+		// Convert parts to integers
+		n1, err := strconv.Atoi(v1Parts[i])
+		if err != nil {
+			return 0, errors.New("invalid version component ", v1Parts[i], " in ", v1)
+		}
+		n2, err := strconv.Atoi(v2Parts[i])
+		if err != nil {
+			return 0, errors.New("invalid version component ", v2Parts[i], " in ", v2)
+		}
+
+		if n1 < n2 {
+			return -1, nil // v1 < v2
+		}
+		if n1 > n2 {
+			return 1, nil // v1 > v2
+		}
+	}
+	return 0, nil // v1 == v2
+}
+
+func init() {
+	common.Must(common.RegisterConfig((*Config)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
+		return New(ctx, config.(*Config))
+	}))
+}