From ecee4e448268c58aea552f521c3166be03c5c236 Mon Sep 17 00:00:00 2001
From: Alireza Ahmadi <alireza7@gmail.com>
Date: Mon, 22 May 2023 23:29:25 +0200
Subject: [PATCH] [feature] fallback link calculation #323

---
 sub/subService.go          | 28 ++++++++++++++++++++++++++++
 web/html/xui/inbounds.html | 28 +++++++++++++++++++++++++---
 2 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/sub/subService.go b/sub/subService.go
index 69000860..9e6ad158 100644
--- a/sub/subService.go
+++ b/sub/subService.go
@@ -38,6 +38,21 @@ func (s *SubService) GetSubs(subId string, host string) ([]string, []string, err
 		if clients == nil {
 			continue
 		}
+		if len(inbound.Listen) > 0 && inbound.Listen[0] == '@' {
+			fallbackMaster, err := s.getFallbackMaster(inbound.Listen)
+			if err == nil {
+				inbound.Listen = fallbackMaster.Listen
+				inbound.Port = fallbackMaster.Port
+				var stream map[string]interface{}
+				json.Unmarshal([]byte(inbound.StreamSettings), &stream)
+				var masterStream map[string]interface{}
+				json.Unmarshal([]byte(fallbackMaster.StreamSettings), &masterStream)
+				stream["security"] = masterStream["security"]
+				stream["tlsSettings"] = masterStream["tlsSettings"]
+				modifiedStream, _ := json.MarshalIndent(stream, "", "  ")
+				inbound.StreamSettings = string(modifiedStream)
+			}
+		}
 		for _, client := range clients {
 			if client.Enable && client.SubID == subId {
 				link := s.getLink(inbound, client.Email)
@@ -93,6 +108,19 @@ func (s *SubService) getClientTraffics(traffics []xray.ClientTraffic, email stri
 	return xray.ClientTraffic{}
 }
 
+func (s *SubService) getFallbackMaster(dest string) (*model.Inbound, error) {
+	db := database.GetDB()
+	var inbound *model.Inbound
+	err := db.Model(model.Inbound{}).
+		Where("JSON_TYPE(settings, '$.fallbacks') = 'array'").
+		Where("EXISTS (SELECT * FROM json_each(settings, '$.fallbacks') WHERE json_extract(value, '$.dest') = ?)", dest).
+		Find(&inbound).Error
+	if err != nil {
+		return nil, err
+	}
+	return inbound, nil
+}
+
 func (s *SubService) getLink(inbound *model.Inbound, email string) string {
 	switch inbound.Protocol {
 	case "vmess":
diff --git a/web/html/xui/inbounds.html b/web/html/xui/inbounds.html
index a9fce618..08d0b112 100644
--- a/web/html/xui/inbounds.html
+++ b/web/html/xui/inbounds.html
@@ -760,11 +760,32 @@
                     default: return client.id;
                 }
             },
+            checkFallback(dbInbound) {
+                newDbInbound = new DBInbound(dbInbound);
+                if (dbInbound.listen.startsWith("@")){
+                    rootInbound = this.inbounds.find((i) => 
+                        i.tls && 
+                        ['trojan','vless'].includes(i.protocol) &&
+                        i.settings.fallbacks.find(f => f.dest === dbInbound.listen)
+                    );
+                    if (rootInbound) {
+                        newDbInbound.listen = rootInbound.listen;
+                        newDbInbound.port = rootInbound.port;
+                        newInbound = newDbInbound.toInbound();
+                        newInbound.stream.security = 'tls';
+                        newInbound.stream.tls = rootInbound.stream.tls;
+                        newDbInbound.streamSettings = newInbound.stream.toString();
+                    }
+                }
+                return newDbInbound;
+            },
             showQrcode(dbInbound, clientIndex) {
-                qrModal.show('{{ i18n "qrCode"}}', dbInbound, clientIndex);
+                newDbInbound = this.checkFallback(dbInbound);
+                qrModal.show('{{ i18n "qrCode"}}', newDbInbound, clientIndex);
             },
             showInfo(dbInbound, index) {
-                infoModal.show(dbInbound, index);
+                newDbInbound = this.checkFallback(dbInbound);
+                infoModal.show(newDbInbound, index);
             },
             switchEnable(dbInboundId) {
                 dbInbound = this.dbInbounds.find(row => row.id === dbInboundId);
@@ -865,7 +886,8 @@
             },
             inboundLinks(dbInboundId) {
                 dbInbound = this.dbInbounds.find(row => row.id === dbInboundId);
-                txtModal.show('{{ i18n "pages.inbounds.export"}}', dbInbound.genInboundLinks, dbInbound.remark);
+                newDbInbound = this.checkFallback(dbInbound);
+                txtModal.show('{{ i18n "pages.inbounds.export"}}', newDbInbound.genInboundLinks, newDbInbound.remark);
             },
 			exportAllLinks() {
                 let copyText = '';