fix(sub): close a deleted host binding only on the inbound it served

Deleting the only host a client was bound to blanked that client on every
inbound. Once the host row was gone, the binding could no longer say which
inbound it guarded, so it failed closed everywhere: a client on inbounds A
and B, bound to one host on A, lost B's link the moment that host was
deleted, and nothing in the panel hinted at it.

Every host delete (host groups, the externalProxy sync, inbound deletion,
the depleted-inbound sweep and the orphan prune) now goes through
database.DeleteHosts, which keeps each deleted host's inbound in
host_tombstones in the same transaction. A binding to a deleted host closes
only that inbound; ids that resolve to no host at all still fail closed
everywhere. The Postgres Host step now runs the deletion cases as well.

.github/workflows/ci.yml

@@ -102,13 +102,13 @@ jobs:
             exit 1
           fi
 
-      - name: PostgreSQL subscription Host ordering tests
+      - name: PostgreSQL subscription Host tests
         run: |
           set -o pipefail
-          go test ./internal/sub -run '^TestSubHostOrder_Postgres$' -count=1 -v | tee /tmp/postgres-host-order.log
+          go test ./internal/sub -run '^TestSubHosts_Postgres$' -count=1 -v | tee /tmp/postgres-hosts.log
-          passed=$(grep -c -- '^--- PASS' /tmp/postgres-host-order.log || true)
+          passed=$(grep -c -- '^--- PASS' /tmp/postgres-hosts.log || true)
           if [ "$passed" -ne 1 ]; then
-            echo "expected passing PostgreSQL Host ordering coverage, got $passed" >&2
+            echo "expected passing PostgreSQL Host coverage, got $passed" >&2
             exit 1
           fi
 

internal/database/db.go

@@ -32,6 +32,7 @@ import (
 	"gorm.io/driver/postgres"
 	"gorm.io/driver/sqlite"
 	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
 	"gorm.io/gorm/logger"
 )
 
@@ -78,6 +79,7 @@ func allModels() []any {
 		&model.ClientGroup{},
 		&model.InboundFallback{},
 		&model.Host{},
+		&model.HostTombstone{},
 		&model.NodeClientTraffic{},
 		&model.NodeClientIp{},
 		&model.ClientGlobalTraffic{},
@@ -873,7 +875,7 @@ func SyncHostsFromExternalProxy(tx *gorm.DB, inboundId int, oldStreamSettings, n
 			continue
 		}
 		if i >= len(added) {
-			if err := tx.Delete(host).Error; err != nil {
+			if _, err := DeleteHosts(tx, "id = ?", host.Id); err != nil {
 				return err
 			}
 			continue
@@ -1048,17 +1050,43 @@ func anyToNonEmptyStrings(v any) []string {
 }
 
 func pruneOrphanedHosts() error {
-	res := db.Exec("DELETE FROM hosts WHERE inbound_id NOT IN (SELECT id FROM inbounds)")
+	var pruned int64
-	if res.Error != nil {
+	err := db.Transaction(func(tx *gorm.DB) error {
-		log.Printf("Error pruning orphaned hosts rows: %v", res.Error)
+		var err error
-		return res.Error
+		pruned, err = DeleteHosts(tx, "inbound_id NOT IN (SELECT id FROM inbounds)")
+		return err
+	})
+	if err != nil {
+		log.Printf("Error pruning orphaned hosts rows: %v", err)
+		return err
 	}
-	if res.RowsAffected > 0 {
+	if pruned > 0 {
-		log.Printf("Pruned %d orphaned hosts row(s)", res.RowsAffected)
+		log.Printf("Pruned %d orphaned hosts row(s)", pruned)
 	}
 	return nil
 }
 
+// DeleteHosts deletes the hosts matching query and keeps each one's inbound in host_tombstones, in
+// the caller's transaction, so a client still bound to one fails closed on that inbound alone.
+func DeleteHosts(tx *gorm.DB, query any, args ...any) (int64, error) {
+	var tombstones []model.HostTombstone
+	if err := tx.Model(&model.Host{}).Select("id AS host_id, inbound_id").Where(query, args...).Scan(&tombstones).Error; err != nil {
+		return 0, err
+	}
+	if len(tombstones) == 0 {
+		return 0, nil
+	}
+	// migrate-db resyncs the hosts sequence to MAX(id), so a deleted id can return; keep its latest inbound.
+	if err := tx.Clauses(clause.OnConflict{
+		Columns:   []clause.Column{{Name: "host_id"}},
+		DoUpdates: clause.AssignmentColumns([]string{"inbound_id"}),
+	}).CreateInBatches(&tombstones, 500).Error; err != nil {
+		return 0, err
+	}
+	res := tx.Where(query, args...).Delete(&model.Host{})
+	return res.RowsAffected, res.Error
+}
+
 func pruneOrphanedClientInbounds() error {
 	res := db.Exec("DELETE FROM client_inbounds WHERE inbound_id NOT IN (SELECT id FROM inbounds)")
 	if res.Error != nil {

internal/database/migrate_data.go

@@ -53,6 +53,7 @@ func migrationModels() []any {
 		&model.ClientGroup{},
 		&model.InboundFallback{},
 		&model.Host{},
+		&model.HostTombstone{},
 		&model.NodeClientTraffic{},
 		&model.NodeClientIp{},
 		&model.ClientGlobalTraffic{},

internal/database/model/model.go

@@ -1221,6 +1221,15 @@ type Host struct {
 
 func (Host) TableName() string { return "hosts" }
 
+// HostTombstone keeps the inbound a deleted host served, so a client still bound to that host
+// fails closed on that inbound alone.
+type HostTombstone struct {
+	HostId    int `json:"hostId" gorm:"primaryKey;autoIncrement:false;column:host_id"`
+	InboundId int `json:"inboundId" gorm:"not null;column:inbound_id"`
+}
+
+func (HostTombstone) TableName() string { return "host_tombstones" }
+
 // KeepAliveSeconds returns a scalar value; ranges are emitted by native AWG config.
 func (c Client) KeepAliveSeconds() int {
 	if c.KeepAlive == nil {

internal/sub/host_order_test.go

@@ -22,7 +22,7 @@ import (
 	"github.com/mhsanaei/3x-ui/v3/internal/web/service"
 )
 
-func TestSubHostOrder_Postgres(t *testing.T) {
+func TestSubHosts_Postgres(t *testing.T) {
 	if os.Getenv("XUI_DB_TYPE") != "postgres" || os.Getenv("XUI_DB_DSN") == "" {
 		t.Skip("requires a disposable PostgreSQL database")
 	}
@@ -34,6 +34,7 @@ func TestSubHostOrder_Postgres(t *testing.T) {
 		{"filters", TestSub_HostOrderFiltersAndFallbacks},
 		{"base64", TestSub_HostOrderBase64AndInfoNode},
 		{"balancer", TestSub_HostOrderBalancerSlots},
+		{"deleted binding", TestSub_ClientHostRule_DeletedHostClosesOnlyItsInbound},
 	} {
 		t.Run(scenario.name, func(t *testing.T) {
 			cleanup, err := testpg.IsolatePackage("host_order")

internal/sub/host_sub.go

@@ -20,35 +20,54 @@ const (
 	hostBindingBound                     // render only the returned bound hosts of this inbound
 )
 
-// clientHostBinding resolves the client's bound host rules against one inbound. A binding whose
+// clientHostBinding resolves the client's bound host rules against one inbound. A deleted bound host
-// every id is gone fails closed; a missing id beside a live one never silences other inbounds.
+// closes only the inbound it served; ids that resolve to no inbound at all fail closed everywhere.
 func (s *SubService) clientHostBinding(inbound *model.Inbound, client model.Client) (hostBinding, []*model.Host) {
 	ids := model.EffectiveClientHostRuleIds(client)
-	if len(ids) == 0 || database.GetDB() == nil {
+	db := database.GetDB()
+	if len(ids) == 0 || db == nil {
 		return hostBindingNone, nil
 	}
 	var rows []model.Host
-	if err := database.GetDB().Where("id IN ?", ids).Find(&rows).Error; err != nil {
+	if err := db.Where("id IN ?", ids).Find(&rows).Error; err != nil {
 		logger.Warning("SubService - clientHostBinding:", err)
 		return hostBindingClosed, nil
 	}
-	if len(rows) == 0 {
-		return hostBindingClosed, nil
-	}
 	byId := make(map[int]*model.Host, len(rows))
 	for i := range rows {
 		byId[rows[i].Id] = &rows[i]
 	}
 	var here []*model.Host
+	var gone []int
 	for _, id := range ids {
-		if h, ok := byId[id]; ok && h.InboundId == inbound.Id {
+		h, ok := byId[id]
+		switch {
+		case !ok:
+			gone = append(gone, id)
+		case h.InboundId == inbound.Id:
 			here = append(here, h)
 		}
 	}
-	if len(here) == 0 {
+	if len(here) > 0 {
+		return hostBindingBound, here
+	}
+	if len(gone) == 0 {
 		return hostBindingNone, nil
 	}
-	return hostBindingBound, here
+	var tombstones []model.HostTombstone
+	if err := db.Where("host_id IN ?", gone).Find(&tombstones).Error; err != nil {
+		logger.Warning("SubService - clientHostBinding:", err)
+		return hostBindingClosed, nil
+	}
+	if len(rows) == 0 && len(tombstones) == 0 {
+		return hostBindingClosed, nil
+	}
+	for _, tomb := range tombstones {
+		if tomb.InboundId == inbound.Id {
+			return hostBindingClosed, nil
+		}
+	}
+	return hostBindingNone, nil
 }
 
 // clientHostEndpoints returns the endpoints of the client's usable bound hosts on this inbound, or

internal/sub/host_sub_test.go

@@ -1160,8 +1160,8 @@ func TestSub_ClientHostRule_MultipleBindings(t *testing.T) {
 	}
 }
 
-// A deleted binding is skipped; with no valid binding left the client fails closed with zero
+// A deleted binding is skipped; a binding that resolves to no inbound fails closed with zero links
-// links (no fallback, no dummy link) but stays in traffic accounting.
+// (no fallback, no dummy link) but stays in traffic accounting.
 func TestSub_ClientHostRule_DeletedFallsBack(t *testing.T) {
 	t.Run("deleted and valid binding renders only the valid host", func(t *testing.T) {
 		seedSubDB(t)
@@ -1191,7 +1191,7 @@ func TestSub_ClientHostRule_DeletedFallsBack(t *testing.T) {
 		}
 	})
 
-	t.Run("deleted-only binding fails closed with zero links", func(t *testing.T) {
+	t.Run("binding that resolves to no inbound fails closed with zero links", func(t *testing.T) {
 		seedSubDB(t)
 		ib := seedSubInbound(t, "s1", "fb", 445, 1, tcpTLSStream)
 		seedHost(t, &model.Host{InboundId: ib.Id, SortOrder: 1, Remark: "A", Address: "a.cdn.com", Port: 443, Security: "tls", Sni: "a.sni"})
@@ -1228,8 +1228,8 @@ func TestSub_ClientHostRule_DeletedFallsBack(t *testing.T) {
 		}
 	})
 
-	// A deleted host id must not silence an inbound without the client's other bound hosts:
+	// An unknown host id must not silence an inbound without the client's other bound hosts: the
-	// relevance comes from rows that still exist, fail-closed only when every bound id is gone.
+	// live and deleted hosts the ids resolve to decide which inbounds the binding guards.
 	t.Run("deleted id on one inbound does not silence an unrelated inbound", func(t *testing.T) {
 		seedSubDB(t)
 		ibA := seedSubInbound(t, "s1", "xa", 4471, 1, tcpTLSStream)
@@ -1267,6 +1267,65 @@ func TestSub_ClientHostRule_DeletedFallsBack(t *testing.T) {
 	})
 }
 
+// Deleting a client's only bound host blanked it on every inbound, since the gone rows no longer
+// said which inbound the binding guarded; only the inbound the host served may close.
+func TestSub_ClientHostRule_DeletedHostClosesOnlyItsInbound(t *testing.T) {
+	for _, tc := range []struct {
+		name   string
+		subId  string
+		portA  int
+		remove func(t *testing.T, ibA *model.Inbound, groupId string) error
+	}{
+		{"by its host group", "dg", 4481, func(_ *testing.T, _ *model.Inbound, groupId string) error {
+			return (&service.HostService{}).DeleteHostGroup(groupId)
+		}},
+		{"with its inbound", "di", 4483, func(t *testing.T, ibA *model.Inbound, _ string) error {
+			if err := database.GetDB().Model(ibA).Update("enable", false).Error; err != nil {
+				t.Fatalf("disable inbound A: %v", err)
+			}
+			_, err := (&service.InboundService{}).DelInbound(ibA.Id)
+			return err
+		}},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			seedSubDB(t)
+			ibA := seedSubInbound(t, tc.subId, tc.subId+"a", tc.portA, 1, tcpTLSStream)
+			ibB := seedSubInbound(t, tc.subId, tc.subId+"b", tc.portA+1, 2, tcpTLSStream)
+			email, groupId := tc.subId+"b@e", tc.subId+"-grp"
+
+			db := database.GetDB()
+			var client model.ClientRecord
+			if err := db.Where("email = ?", email).First(&client).Error; err != nil {
+				t.Fatalf("load client %s: %v", email, err)
+			}
+			if err := db.Create(&model.ClientInbound{ClientId: client.Id, InboundId: ibA.Id}).Error; err != nil {
+				t.Fatalf("link client to inbound A: %v", err)
+			}
+			hostA := seedHost(t, &model.Host{GroupId: groupId, InboundId: ibA.Id, SortOrder: 1, Remark: "A", Address: "a.cdn.com", Port: 443, Security: "tls", Sni: "a.sni"})
+			if err := db.Model(&model.ClientRecord{}).Where("email = ?", email).
+				Update("client_host_rule_ids", model.EncodeClientHostRuleIds([]int{hostA.Id})).Error; err != nil {
+				t.Fatalf("bind host rule: %v", err)
+			}
+			if err := tc.remove(t, ibA, groupId); err != nil {
+				t.Fatalf("delete the bound host: %v", err)
+			}
+
+			links, _, _, _, err := NewSubService("").GetSubs(tc.subId, "req.example.com")
+			if err != nil {
+				t.Fatalf("GetSubs: %v", err)
+			}
+			joined := strings.Join(links, "\n")
+			uuid := "11111111-2222-4333-8444-" + fmt.Sprintf("%012d", ibB.Port)
+			if strings.Contains(joined, "a.cdn.com") || strings.Contains(joined, fmt.Sprintf("%s@203.0.113.5:%d", uuid, ibA.Port)) {
+				t.Fatalf("inbound A lost the client's bound host and must render nothing for it: %s", joined)
+			}
+			if !strings.Contains(joined, fmt.Sprintf("%s@203.0.113.5:%d", uuid, ibB.Port)) {
+				t.Fatalf("inbound B never had a binding and must keep the client's link: %s", joined)
+			}
+		})
+	}
+}
+
 // A client bound to a disabled host fails closed on every format (no links, outbounds or proxies)
 // but stays in traffic accounting, so quota and expiry headers stay correct.
 func TestSub_ClientHostRule_DisabledFailsClosed(t *testing.T) {

internal/web/service/host.go

@@ -337,7 +337,7 @@ func (s *HostService) UpdateHostGroup(groupId string, req *entity.HostGroup) ([]
 			}
 		}
 		if len(toDelete) > 0 {
-			if err := tx.Where("id IN ?", toDelete).Delete(&model.Host{}).Error; err != nil {
+			if _, err := database.DeleteHosts(tx, "id IN ?", toDelete); err != nil {
 				return err
 			}
 		}
@@ -360,7 +360,10 @@ func (s *HostService) UpdateHostGroup(groupId string, req *entity.HostGroup) ([]
 }
 
 func (s *HostService) DeleteHostGroup(groupId string) error {
-	return database.GetDB().Where("group_id = ?", groupId).Delete(&model.Host{}).Error
+	return database.GetDB().Transaction(func(tx *gorm.DB) error {
+		_, err := database.DeleteHosts(tx, "group_id = ?", groupId)
+		return err
+	})
 }
 
 func (s *HostService) SetHostGroupEnable(groupId string, enable bool) error {
@@ -378,7 +381,10 @@ func (s *HostService) DeleteHostsGroup(groupIds []string) error {
 	if len(groupIds) == 0 {
 		return nil
 	}
-	return database.GetDB().Where("group_id IN ?", groupIds).Delete(&model.Host{}).Error
+	return database.GetDB().Transaction(func(tx *gorm.DB) error {
+		_, err := database.DeleteHosts(tx, "group_id IN ?", groupIds)
+		return err
+	})
 }
 
 func (s *HostService) ReorderHostGroups(groupIds []string) error {

internal/web/service/inbound.go

@@ -1665,7 +1665,7 @@ func (s *InboundService) delInbound(id int) (bool, func(), error) {
 		if err := tx.Delete(model.Inbound{}, id).Error; err != nil {
 			return err
 		}
-		if err := tx.Where("inbound_id = ?", id).Delete(&model.Host{}).Error; err != nil {
+		if _, err := database.DeleteHosts(tx, "inbound_id = ?", id); err != nil {
 			return err
 		}
 		// Drop the deleted inbound from any sub-balancer that selects it; a

internal/web/service/inbound_traffic.go

@@ -964,7 +964,7 @@ func (s *InboundService) DelDepletedClients(id int) (err error) {
 				if err := s.clientService.DetachInbound(tx, inbound.Id); err != nil {
 					return err
 				}
-				if err := tx.Where("inbound_id = ?", inbound.Id).Delete(&model.Host{}).Error; err != nil {
+				if _, err := database.DeleteHosts(tx, "inbound_id = ?", inbound.Id); err != nil {
 					return err
 				}
 				if err := tx.Delete(model.Inbound{}, inbound.Id).Error; err != nil {