From 6d89b8674f2d854286fb672e4f634c89794ad74d Mon Sep 17 00:00:00 2001
From: wjqserver <114663932+WJQSERVER@users.noreply.github.com>
Date: Sun, 29 Mar 2026 01:39:09 +0800
Subject: [PATCH] fix: tighten reverse proxy safety handling

Avoid HTTP error writes after hijacking upgraded connections, document ModifyResponse constraints for 101 responses, and normalize forwarded query strings consistently to reduce parsing ambiguity across proxy chains.
---
 docs/reverse-proxy.md | 7 +++++++
 reverseproxy.go       | 9 +++++----
 reverseproxy_test.go  | 2 +-
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/docs/reverse-proxy.md b/docs/reverse-proxy.md
index e495a19..1f8a353 100644
--- a/docs/reverse-proxy.md
+++ b/docs/reverse-proxy.md
@@ -168,10 +168,17 @@ r.ANY("/api/*path", touka.ReverseProxy(touka.ReverseProxyConfig{
 
 在后端返回响应后、写回客户端前，对响应做额外处理。
 
+注意：`ModifyResponse` 也会作用于 `101 Switching Protocols` 响应。
+如果该代理路由需要转发 WebSocket 或其他 Upgrade 流量，请不要在这里消费、完全缓冲，或替换 `resp.Body` 为只读对象；后续升级流程仍然要求它保留 `io.ReadWriteCloser` 能力。
+更稳妥的做法是对 `101` 响应直接跳过这类处理。
+
 ```go
 r.ANY("/api/*path", touka.ReverseProxy(touka.ReverseProxyConfig{
     Target: target,
     ModifyResponse: func(resp *http.Response) error {
+        if resp.StatusCode == http.StatusSwitchingProtocols {
+            return nil
+        }
         resp.Header.Set("X-Proxy", "touka")
         return nil
     },
diff --git a/reverseproxy.go b/reverseproxy.go
index f486364..c635a1f 100644
--- a/reverseproxy.go
+++ b/reverseproxy.go
@@ -472,6 +472,10 @@ func (p *reverseProxyHandler) handleError(c *Context, err error) {
 		return
 	}
 	c.AddError(err)
+	if c.Writer.IsHijacked() {
+		p.logf(c, "reverse proxy error after hijack: %v", err)
+		return
+	}
 	if p.config.ErrorHandler != nil {
 		p.config.ErrorHandler(c.Writer, c.Request, err)
 		if c.Writer.Written() || c.Writer.IsHijacked() {
@@ -906,10 +910,7 @@ func cleanReverseProxyQueryParams(rawQuery string) string {
 	if rawQuery == "" {
 		return ""
 	}
-	values, err := url.ParseQuery(rawQuery)
-	if err == nil {
-		return rawQuery
-	}
+	values, _ := url.ParseQuery(rawQuery)
 	return values.Encode()
 }
 
diff --git a/reverseproxy_test.go b/reverseproxy_test.go
index 1b643ef..f82aff9 100644
--- a/reverseproxy_test.go
+++ b/reverseproxy_test.go
@@ -74,7 +74,7 @@ func TestReverseProxyForwardingAndHopHeaders(t *testing.T) {
 		Via:              "proxy.test",
 	}))
 
-	req := httptest.NewRequest(http.MethodGet, "http://client.example/api/ping?q=2", nil)
+	req := httptest.NewRequest(http.MethodGet, "http://client.example/api/ping?bad=1;smuggle=2&q=2", nil)
 	req.Host = "client.example"
 	req.RemoteAddr = "198.51.100.10:4567"
 	req.Header.Set("Connection", "X-Remove-Me")