From 84c3799e21d61d677965715fe09f8209660b4009 Mon Sep 17 00:00:00 2001
From: Stephen Guo <stephen.fire@gmail.com>
Date: Wed, 17 May 2023 18:27:51 +0800
Subject: [PATCH] rpc: more accurate checking of handler method signatures
 (#27287)

This changes the RPC server to ignore methods using *context.Context as parameter
and *error as return value type. Methods with such types would crash the server when
called.
---
 rpc/service.go | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/rpc/service.go b/rpc/service.go
index cfdfba023a..8485cab3aa 100644
--- a/rpc/service.go
+++ b/rpc/service.go
@@ -214,19 +214,8 @@ func (c *callback) call(ctx context.Context, method string, args []reflect.Value
 	return results[0].Interface(), nil
 }
 
-// Is t context.Context or *context.Context?
-func isContextType(t reflect.Type) bool {
-	for t.Kind() == reflect.Ptr {
-		t = t.Elem()
-	}
-	return t == contextType
-}
-
 // Does t satisfy the error interface?
 func isErrorType(t reflect.Type) bool {
-	for t.Kind() == reflect.Ptr {
-		t = t.Elem()
-	}
 	return t.Implements(errorType)
 }
 
@@ -245,7 +234,7 @@ func isPubSub(methodType reflect.Type) bool {
 	if methodType.NumIn() < 2 || methodType.NumOut() != 2 {
 		return false
 	}
-	return isContextType(methodType.In(1)) &&
+	return methodType.In(1) == contextType &&
 		isSubscriptionType(methodType.Out(0)) &&
 		isErrorType(methodType.Out(1))
 }