From 57337531b75b38c57247ea4cfa40f8cdb188370c Mon Sep 17 00:00:00 2001
From: ningmingxiao <ning.mingxiao@zte.com.cn>
Date: Fri, 12 Dec 2025 16:52:20 +0800
Subject: [PATCH] fix: catch discard error and return

Signed-off-by: ningmingxiao <ning.mingxiao@zte.com.cn>
---
 channel.go | 4 +++-
 errors.go  | 8 ++++++++
 server.go  | 5 +++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/channel.go b/channel.go
index 872261e6d..33553746b 100644
--- a/channel.go
+++ b/channel.go
@@ -125,7 +125,9 @@ func (ch *channel) recv() (messageHeader, []byte, error) {
 
 	if mh.Length > uint32(messageLengthMax) {
 		if _, err := ch.br.Discard(int(mh.Length)); err != nil {
-			return mh, nil, fmt.Errorf("failed to discard after receiving oversized message: %w", err)
+			return mh, nil, &discardError{
+				error: fmt.Errorf("failed to discard oversized message (length %d exceeds maximum message size %d): %w", mh.Length, messageLengthMax, err),
+			}
 		}
 
 		return mh, nil, status.Errorf(codes.ResourceExhausted, "message length %v exceed maximum message size of %v", mh.Length, messageLengthMax)
diff --git a/errors.go b/errors.go
index 1e6f6b9c9..bf2072fd3 100644
--- a/errors.go
+++ b/errors.go
@@ -84,3 +84,11 @@ func (e *OversizedMessageErr) RejectedLength() int {
 func (*OversizedMessageErr) MaximumLength() int {
 	return messageLengthMax
 }
+
+type discardError struct {
+	error
+}
+
+func (e *discardError) Unwrap() error {
+	return e.error
+}
diff --git a/server.go b/server.go
index b8c0689cc..05f61c0da 100644
--- a/server.go
+++ b/server.go
@@ -560,6 +560,11 @@ func (c *serverConn) run(sctx context.Context) {
 				// requests, so that the client connection is closed
 				return
 			}
+			var discardErr *discardError
+			if errors.As(err, &discardErr) {
+				log.G(ctx).WithError(err).Error("discard failed")
+				return
+			}
 			log.G(ctx).WithError(err).Error("error receiving message")
 			// else, initiate shutdown
 		case <-shutdown: