Add subscription.process.rewrite_multiplex

docs/configuration/subscription.md

@@ -12,7 +12,8 @@
       "filter_outbound_type": [],
       "exclude_outbound_type": [],
       "rename": {},
-      "remove_emoji": false
+      "remove_emoji": false,
+      "rewrite_multiplex": {}
     }
   ],
   "deduplication": false,
@@ -77,6 +78,10 @@ Regexp rename rules, matching outbounds will be renamed.
 
 Remove emojis in outbound tags.
 
+#### process.rewrite_multiplex
+
+Rewrite [Multiplex](https://sing-box.sagernet.org/configuration/shared/multiplex) options.
+
 #### deduplication
 
 Remove outbounds with duplicate server destinations (Domain will be resolved to compare).

option/options.go

@@ -68,6 +68,7 @@ type OutboundProcessOptions struct {
 	ExcludeOutboundType option.Listable[string]           `json:"exclude_outbound_type,omitempty"`
 	Rename              *badjson.TypedMap[string, string] `json:"rename,omitempty"`
 	RemoveEmoji         bool                              `json:"remove_emoji,omitempty"`
+	RewriteMultiplex    *option.OutboundMultiplexOptions  `json:"rewrite_multiplex,omitempty"`
 }
 
 type Profile struct {

subscription/process.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 
 	"github.com/sagernet/serenity/option"
+	C "github.com/sagernet/sing-box/constant"
 	boxOption "github.com/sagernet/sing-box/option"
 	"github.com/sagernet/sing/common"
 	E "github.com/sagernet/sing/common/exceptions"
@@ -103,6 +104,18 @@ func (o *ProcessOptions) Process(outbounds []boxOption.Outbound) []boxOption.Out
 		if originTag != outbound.Tag {
 			renameResult[originTag] = outbound.Tag
 		}
+		if o.RewriteMultiplex != nil {
+			switch outbound.Type {
+			case C.TypeShadowsocks:
+				outbound.ShadowsocksOptions.Multiplex = o.RewriteMultiplex
+			case C.TypeTrojan:
+				outbound.TrojanOptions.Multiplex = o.RewriteMultiplex
+			case C.TypeVMess:
+				outbound.VMessOptions.Multiplex = o.RewriteMultiplex
+			case C.TypeVLESS:
+				outbound.VLESSOptions.Multiplex = o.RewriteMultiplex
+			}
+		}
 		newOutbounds = append(newOutbounds, outbound)
 	}
 	if len(renameResult) > 0 {