[PATCH net] net/smc: sync err code when tcp connection was refused

From: liuyacan@corp.netease.com
To: kgraul@linux.ibm.com, davem@davemloft.net, kuba@kernel.org,
	pabeni@redhat.com
Cc: linux-s390@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	liuyacan <liuyacan@corp.netease.com>,
	Tony Lu <tonylu@linux.alibaba.com>
Subject: [PATCH net] net/smc: sync err code when tcp connection was refused
Date: Thu, 21 Apr 2022 17:40:27 +0800	[thread overview]
Message-ID: <20220421094027.683992-1-liuyacan@corp.netease.com> (raw)

From: liuyacan <liuyacan@corp.netease.com>

In the current implementation, when TCP initiates a connection
to an unavailable [ip,port], ECONNREFUSED will be stored in the
TCP socket, but SMC will not. However, some apps (like curl) use
getsockopt(,,SO_ERROR,,) to get the error information, which makes
them miss the error message and behave strangely.

Fixes: 50717a37db03 ("net/smc: nonblocking connect rework")
Signed-off-by: liuyacan <liuyacan@corp.netease.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
---
 net/smc/af_smc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index fc7b6eb22..bbb1a4ce5 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1475,6 +1475,8 @@ static void smc_connect_work(struct work_struct *work)
 		smc->sk.sk_state = SMC_CLOSED;
 		if (rc == -EPIPE || rc == -EAGAIN)
 			smc->sk.sk_err = EPIPE;
+		else if (rc == -ECONNREFUSED)
+			smc->sk.sk_err = ECONNREFUSED;
 		else if (signal_pending(current))
 			smc->sk.sk_err = -sock_intr_errno(timeo);
 		sock_put(&smc->sk); /* passive closing */
-- 
2.20.1

