fix(clients): store flow per-inbound for shared clients

A client shared across inbounds (e.g. VLESS+TCP+Reality and VLESS+WS+TLS)
had its `flow` applied globally, so enabling xtls-rprx-vision for Reality
broke the WS+TLS inbound for the same client (#4628).

Gate flow per inbound at every fan-out site via clientWithInboundFlow,
reusing inboundCanEnableTlsFlow (VLESS+TCP+TLS/Reality only), and make
ListForInbound treat flow_override as authoritative so an empty override
means "no flow on this inbound" instead of inheriting the record's global
flow. Also tighten buildTargetClientFromSource (copy-clients) to gate on
transport, not just protocol.

web/service/client.go

@@ -299,9 +299,7 @@ func (s *ClientService) ListForInbound(tx *gorm.DB, inboundId int) ([]model.Clie
 	out := make([]model.Client, 0, len(rows))
 	for i := range rows {
 		c := rows[i].ToClient()
-		if rows[i].FlowOverride != "" {
-			c.Flow = rows[i].FlowOverride
-		}
+		c.Flow = rows[i].FlowOverride
 		out = append(out, *c)
 	}
 	return out, nil
@@ -455,7 +453,7 @@ func (s *ClientService) Create(inboundSvc *InboundService, payload *ClientCreate
 		if err := s.fillProtocolDefaults(&client, inbound); err != nil {
 			return needRestart, err
 		}
-		settingsPayload, mErr := json.Marshal(map[string][]model.Client{"clients": {client}})
+		settingsPayload, mErr := json.Marshal(map[string][]model.Client{"clients": {clientWithInboundFlow(client, inbound)}})
 		if mErr != nil {
 			return needRestart, mErr
 		}
@@ -496,8 +494,13 @@ func (s *ClientService) fillProtocolDefaults(c *model.Client, ib *model.Inbound)
 	return nil
 }
 
-// shadowsocksMethodFromSettings pulls the "method" field out of the inbound's
-// settings JSON. Returns "" when the field is missing or settings is invalid.
+func clientWithInboundFlow(c model.Client, ib *model.Inbound) model.Client {
+	if !inboundCanEnableTlsFlow(string(ib.Protocol), ib.StreamSettings) {
+		c.Flow = ""
+	}
+	return c
+}
+
 func shadowsocksMethodFromSettings(settings string) string {
 	if settings == "" {
 		return ""
@@ -510,11 +513,6 @@ func shadowsocksMethodFromSettings(settings string) string {
 	return method
 }
 
-// randomShadowsocksClientKey returns a per-client key sized to the cipher.
-// The 2022-blake3 ciphers require a base64-encoded key of an exact byte
-// length (16 bytes for aes-128-gcm, 32 bytes for aes-256-gcm and
-// chacha20-poly1305) — anything else fails with "bad key" on xray start.
-// Older ciphers accept arbitrary passwords, so we keep the uuid-style.
 func randomShadowsocksClientKey(method string) string {
 	if n := shadowsocksKeyBytes(method); n > 0 {
 		return random.Base64Bytes(n)
@@ -522,9 +520,6 @@ func randomShadowsocksClientKey(method string) string {
 	return strings.ReplaceAll(uuid.NewString(), "-", "")
 }
 
-// validShadowsocksClientKey reports whether key is acceptable for the cipher.
-// For 2022-blake3 it must decode to the exact byte length the cipher needs;
-// any other method accepts any non-empty string.
 func validShadowsocksClientKey(method, key string) bool {
 	n := shadowsocksKeyBytes(method)
 	if n == 0 {
@@ -547,13 +542,6 @@ func shadowsocksKeyBytes(method string) int {
 	return 0
 }
 
-// applyShadowsocksClientMethod normalises the per-client "method" field
-// when an inbound is created or updated:
-//   - Legacy ciphers: backfill `method` so xray's multi-user code is happy.
-//     "unsupported cipher method:" otherwise.
-//   - 2022-blake3-*: strip the per-client `method` because xray rejects
-//     it with "users must have empty method". This matters after an admin
-//     switches an existing inbound from a legacy cipher to a 2022 one.
 func applyShadowsocksClientMethod(clients []any, settings map[string]any) {
 	method, _ := settings["method"].(string)
 	is2022 := strings.HasPrefix(method, "2022-blake3-")
@@ -604,10 +592,6 @@ func (s *ClientService) Update(inboundSvc *InboundService, id int, updated model
 		updated.CreatedAt = existing.CreatedAt
 	}
 
-	// Rename the ClientRecord row up front when the email changes. SyncInbound
-	// (invoked from UpdateInboundClient below) looks up by email — without
-	// renaming first it would treat the new email as a brand-new client,
-	// insert a duplicate ClientRecord, and leave the original orphaned.
 	if updated.Email != existing.Email {
 		var collisionCount int64
 		if err := database.GetDB().Model(&model.ClientRecord{}).
@@ -646,7 +630,7 @@ func (s *ClientService) Update(inboundSvc *InboundService, id int, updated model
 		if err := s.fillProtocolDefaults(&updated, inbound); err != nil {
 			return needRestart, err
 		}
-		settingsPayload, mErr := json.Marshal(map[string][]model.Client{"clients": {updated}})
+		settingsPayload, mErr := json.Marshal(map[string][]model.Client{"clients": {clientWithInboundFlow(updated, inbound)}})
 		if mErr != nil {
 			return needRestart, mErr
 		}
@@ -752,7 +736,7 @@ func (s *ClientService) Attach(inboundSvc *InboundService, id int, inboundIds []
 		if err := s.fillProtocolDefaults(&copyClient, inbound); err != nil {
 			return needRestart, err
 		}
-		settingsPayload, mErr := json.Marshal(map[string][]model.Client{"clients": {copyClient}})
+		settingsPayload, mErr := json.Marshal(map[string][]model.Client{"clients": {clientWithInboundFlow(copyClient, inbound)}})
 		if mErr != nil {
 			return needRestart, mErr
 		}
@@ -870,7 +854,7 @@ func (s *ClientService) BulkAttach(inboundSvc *InboundService, emails []string,
 				recordErr("%s -> inbound %d: %v", rec.Email, ibId, err)
 				continue
 			}
-			clientsToAdd = append(clientsToAdd, client)
+			clientsToAdd = append(clientsToAdd, clientWithInboundFlow(client, inbound))
 		}
 
 		if len(clientsToAdd) == 0 {

web/service/client_flow_isolation_test.go

@@ -0,0 +1,85 @@
+package service
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/mhsanaei/3x-ui/v3/database"
+	"github.com/mhsanaei/3x-ui/v3/database/model"
+)
+
+func TestClientWithInboundFlow_GatesByInboundCapability(t *testing.T) {
+	const vision = "xtls-rprx-vision"
+	cases := []struct {
+		name           string
+		protocol       model.Protocol
+		streamSettings string
+		wantFlow       string
+	}{
+		{"vless tcp reality keeps flow", model.VLESS, `{"network":"tcp","security":"reality"}`, vision},
+		{"vless tcp tls keeps flow", model.VLESS, `{"network":"tcp","security":"tls"}`, vision},
+		{"vless ws tls clears flow", model.VLESS, `{"network":"ws","security":"tls"}`, ""},
+		{"vless grpc tls clears flow", model.VLESS, `{"network":"grpc","security":"tls"}`, ""},
+		{"vless tcp none clears flow", model.VLESS, `{"network":"tcp","security":"none"}`, ""},
+		{"vmess tcp tls clears flow", model.VMESS, `{"network":"tcp","security":"tls"}`, ""},
+		{"empty stream clears flow", model.VLESS, "", ""},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			ib := &model.Inbound{Protocol: tc.protocol, StreamSettings: tc.streamSettings}
+			got := clientWithInboundFlow(model.Client{Email: "x@example.com", Flow: vision}, ib)
+			if got.Flow != tc.wantFlow {
+				t.Errorf("Flow = %q, want %q", got.Flow, tc.wantFlow)
+			}
+		})
+	}
+}
+
+func TestFlowIsolation_VisionDoesNotLeakToWsInbound(t *testing.T) {
+	dbDir := t.TempDir()
+	t.Setenv("XUI_DB_FOLDER", dbDir)
+	if err := database.InitDB(filepath.Join(dbDir, "3x-ui.db")); err != nil {
+		t.Fatalf("InitDB: %v", err)
+	}
+	t.Cleanup(func() { _ = database.CloseDB() })
+
+	db := database.GetDB()
+
+	wsTls := &model.Inbound{Tag: "vless-ws", Enable: true, Port: 30001, Protocol: model.VLESS, StreamSettings: `{"network":"ws","security":"tls"}`}
+	if err := db.Create(wsTls).Error; err != nil {
+		t.Fatalf("create ws+tls inbound: %v", err)
+	}
+	reality := &model.Inbound{Tag: "vless-reality", Enable: true, Port: 30002, Protocol: model.VLESS, StreamSettings: `{"network":"tcp","security":"reality"}`}
+	if err := db.Create(reality).Error; err != nil {
+		t.Fatalf("create reality inbound: %v", err)
+	}
+
+	svc := ClientService{}
+	const email = "shared@example.com"
+	const uid = "ce8d33df-3a64-4f10-8f9b-91c3a8e0c003"
+	const vision = "xtls-rprx-vision"
+
+	source := model.Client{Email: email, ID: uid, Enable: true, Flow: vision}
+	for _, ib := range []*model.Inbound{wsTls, reality} {
+		gated := clientWithInboundFlow(source, ib)
+		if err := svc.SyncInbound(nil, ib.Id, []model.Client{gated}); err != nil {
+			t.Fatalf("SyncInbound(%s): %v", ib.Tag, err)
+		}
+	}
+
+	realityList, err := svc.ListForInbound(nil, reality.Id)
+	if err != nil {
+		t.Fatalf("ListForInbound(reality): %v", err)
+	}
+	if len(realityList) != 1 || realityList[0].Flow != vision {
+		t.Errorf("Reality inbound should keep flow=%q, got %#v", vision, realityList)
+	}
+
+	wsList, err := svc.ListForInbound(nil, wsTls.Id)
+	if err != nil {
+		t.Fatalf("ListForInbound(ws): %v", err)
+	}
+	if len(wsList) != 1 || wsList[0].Flow != "" {
+		t.Errorf("WS+TLS inbound must not inherit Vision flow (#4628), got %#v", wsList)
+	}
+}

web/service/inbound.go

@@ -1074,7 +1074,7 @@ func (s *InboundService) generateRandomCredential(targetProtocol model.Protocol)
 	}
 }
 
-func (s *InboundService) buildTargetClientFromSource(source model.Client, targetProtocol model.Protocol, email string, flow string) (model.Client, error) {
+func (s *InboundService) buildTargetClientFromSource(source model.Client, targetInbound *model.Inbound, email string, flow string) (model.Client, error) {
 	nowTs := time.Now().UnixMilli()
 	target := source
 	target.Email = email
@@ -1086,12 +1086,14 @@ func (s *InboundService) buildTargetClientFromSource(source model.Client, target
 	target.Auth = ""
 	target.Flow = ""
 
+	targetProtocol := targetInbound.Protocol
 	switch targetProtocol {
 	case model.VMESS:
 		target.ID = s.generateRandomCredential(targetProtocol)
 	case model.VLESS:
 		target.ID = s.generateRandomCredential(targetProtocol)
-		if flow == "xtls-rprx-vision" || flow == "xtls-rprx-vision-udp443" {
+		if (flow == "xtls-rprx-vision" || flow == "xtls-rprx-vision-udp443") &&
+			inboundCanEnableTlsFlow(string(targetProtocol), targetInbound.StreamSettings) {
 			target.Flow = flow
 		}
 	case model.Trojan, model.Shadowsocks:
@@ -1192,7 +1194,7 @@ func (s *InboundService) CopyInboundClients(targetInboundID int, sourceInboundID
 		}
 
 		targetEmail := s.nextAvailableCopiedEmail(originalEmail, targetInboundID, occupiedEmails)
-		targetClient, buildErr := s.buildTargetClientFromSource(sourceClient, targetInbound.Protocol, targetEmail, flow)
+		targetClient, buildErr := s.buildTargetClientFromSource(sourceClient, targetInbound, targetEmail, flow)
 		if buildErr != nil {
 			result.Errors = append(result.Errors, fmt.Sprintf("%s: %v", originalEmail, buildErr))
 			continue