Mux server: Clone the session.Content attached on ctx as well

https://github.com/XTLS/Xray-core/pull/3908#issuecomment-2696911994

Fixes https://github.com/XTLS/Xray-core/pull/3904 for good

app/proxyman/inbound/worker.go

@@ -324,6 +324,7 @@ func (w *udpWorker) callback(b *buf.Buffer, source net.Destination, originalDest
 			if w.sniffingConfig != nil {
 				content.SniffingRequest.Enabled = w.sniffingConfig.Enabled
 				content.SniffingRequest.OverrideDestinationForProtocol = w.sniffingConfig.DestinationOverride
+				content.SniffingRequest.ExcludeForDomain = w.sniffingConfig.DomainsExcluded
 				content.SniffingRequest.MetadataOnly = w.sniffingConfig.MetadataOnly
 				content.SniffingRequest.RouteOnly = w.sniffingConfig.RouteOnly
 			}

common/mux/server.go

@@ -120,7 +120,7 @@ func (w *ServerWorker) handleStatusKeepAlive(meta *FrameMetadata, reader *buf.Bu
 func (w *ServerWorker) handleStatusNew(ctx context.Context, meta *FrameMetadata, reader *buf.BufferedReader) error {
 	// deep-clone outbounds because it is going to be mutated concurrently
 	// (Target and OriginalTarget)
-	ctx = session.ContextCloneOutbounds(ctx)
+	ctx = session.ContextCloneOutboundsAndContent(ctx)
 	errors.LogInfo(ctx, "received request for ", meta.Target)
 	{
 		msg := &log.AccessMessage{

common/protocol/http/sniff.go

@@ -63,7 +63,7 @@ func SniffHTTP(b []byte, c context.Context) (*SniffHeader, error) {
 	ShouldSniffAttr := true
 	// If content.Attributes have information, that means it comes from HTTP inbound PlainHTTP mode.
 	// It will set attributes, so skip it.
-	if content == nil || content.AttributeLen() != 0 {
+	if content == nil || len(content.Attributes) != 0 {
 		ShouldSniffAttr = false
 	}
 	if err := beginWithHTTPMethod(b); err != nil {

common/session/context.go

@@ -42,7 +42,7 @@ func ContextWithOutbounds(ctx context.Context, outbounds []*Outbound) context.Co
 	return context.WithValue(ctx, outboundSessionKey, outbounds)
 }
 
-func ContextCloneOutbounds(ctx context.Context) context.Context {
+func ContextCloneOutboundsAndContent(ctx context.Context) context.Context {
 	outbounds := OutboundsFromContext(ctx)
 	newOutbounds := make([]*Outbound, len(outbounds))
 	for i, ob := range outbounds {
@@ -55,7 +55,15 @@ func ContextCloneOutbounds(ctx context.Context) context.Context {
 		newOutbounds[i] = &v
 	}
 
-	return ContextWithOutbounds(ctx, newOutbounds)
+	content := ContentFromContext(ctx)
+	newContent := Content{}
+	if content != nil {
+		newContent = *content
+		if content.Attributes != nil {
+			panic("content.Attributes != nil")
+		}
+	}
+	return ContextWithContent(ContextWithOutbounds(ctx, newOutbounds), &newContent)
 }
 
 func OutboundsFromContext(ctx context.Context) []*Outbound {

common/session/session.go

@@ -4,7 +4,6 @@ package session // import "github.com/xtls/xray-core/common/session"
 import (
 	"context"
 	"math/rand"
-	"sync"
 
 	c "github.com/xtls/xray-core/common/ctx"
 	"github.com/xtls/xray-core/common/errors"
@@ -75,8 +74,8 @@ type Outbound struct {
 
 // SniffingRequest controls the behavior of content sniffing.
 type SniffingRequest struct {
-	ExcludeForDomain               []string
+	ExcludeForDomain               []string // read-only once set
-	OverrideDestinationForProtocol []string
+	OverrideDestinationForProtocol []string // read-only once set
 	Enabled                        bool
 	MetadataOnly                   bool
 	RouteOnly                      bool
@@ -92,10 +91,6 @@ type Content struct {
 	Attributes map[string]string
 
 	SkipDNSResolve bool
-
-	mu sync.Mutex
-
-	isLocked bool
 }
 
 // Sockopt is the settings for socket connection.
@@ -104,22 +99,8 @@ type Sockopt struct {
 	Mark int32
 }
 
-// Some how when using mux, there will be a same ctx between different requests
-// This will cause problem as it's designed for single request, like concurrent map writes
-// Add a Mutex as a temp solution
-
 // SetAttribute attaches additional string attributes to content.
 func (c *Content) SetAttribute(name string, value string) {
-	if c.isLocked {
-		errors.LogError(context.Background(), "Multiple goroutines are tring to access one routing content, tring to write ", name, ":", value)
-	}
-	c.mu.Lock()
-	c.isLocked = true
-	defer func() {
-		c.isLocked = false
-		c.mu.Unlock()
-	}()
-
 	if c.Attributes == nil {
 		c.Attributes = make(map[string]string)
 	}
@@ -128,24 +109,8 @@ func (c *Content) SetAttribute(name string, value string) {
 
 // Attribute retrieves additional string attributes from content.
 func (c *Content) Attribute(name string) string {
-	c.mu.Lock()
-	c.isLocked = true
-	defer func() {
-		c.isLocked = false
-		c.mu.Unlock()
-	}()
 	if c.Attributes == nil {
 		return ""
 	}
 	return c.Attributes[name]
 }
-
-func (c *Content) AttributeLen() int {
-	c.mu.Lock()
-	c.isLocked = true
-	defer func() {
-		c.isLocked = false
-		c.mu.Unlock()
-	}()
-	return len(c.Attributes)
-}