修复局域网连接出错问题

backend/internal/handler/http.go

@@ -2,7 +2,11 @@ package handler
 
 import (
 	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
 	"net/http"
+	"net/netip"
 	"net/url"
 	"path/filepath"
 	"strings"
@@ -118,6 +122,14 @@ func (h *HTTPHandler) registerDevice(c *gin.Context) {
 		return
 	}
 
+	networkGroupKey, publicIPHash := deriveClientNetworkIdentity(c.ClientIP())
+	if networkGroupKey != "" {
+		input.NetworkGroupKey = networkGroupKey
+	}
+	if publicIPHash != "" {
+		input.PublicIPHash = publicIPHash
+	}
+
 	device, session := h.deps.DeviceService.Register(input, c.Request.UserAgent(), c.GetHeader("X-Device-Token"))
 	c.JSON(http.StatusOK, gin.H{"data": gin.H{
 		"id":                device.ID,
@@ -611,6 +623,46 @@ func decodeDownloadFilename(filename string) string {
 	return strings.TrimSpace(decoded)
 }
 
+func deriveClientNetworkIdentity(clientIP string) (string, string) {
+	addr, err := netip.ParseAddr(strings.TrimSpace(clientIP))
+	if err != nil {
+		return "", ""
+	}
+
+	addr = addr.Unmap()
+	hash := hashIP(addr.String())
+
+	if addr.IsLoopback() {
+		return "loopback", hash
+	}
+
+	if addr.Is4() {
+		bytes := addr.As4()
+		switch {
+		case bytes[0] == 10 || bytes[0] == 127:
+			return fmt.Sprintf("v4:%d.%d.%d", bytes[0], bytes[1], bytes[2]), hash
+		case bytes[0] == 192 && bytes[1] == 168:
+			return fmt.Sprintf("v4:%d.%d.%d", bytes[0], bytes[1], bytes[2]), hash
+		case bytes[0] == 172 && bytes[1] >= 16 && bytes[1] <= 31:
+			return fmt.Sprintf("v4:%d.%d.%d", bytes[0], bytes[1], bytes[2]), hash
+		default:
+			return "pub4:" + hash[:16], hash
+		}
+	}
+
+	prefix := netip.PrefixFrom(addr, 64).Masked()
+	if addr.IsPrivate() {
+		return "v6:" + prefix.Addr().String(), hash
+	}
+
+	return "pub6:" + hash[:16], hash
+}
+
+func hashIP(value string) string {
+	sum := sha256.Sum256([]byte(strings.TrimSpace(value)))
+	return hex.EncodeToString(sum[:])
+}
+
 func (h *HTTPHandler) ensureFallbackBucket(ctx context.Context, transferID string) error {
 	if h.deps.MinIOClient == nil {
 		return nil