From 395a2076b4064f97d3fce03af15210ff2a7bb7f9 Mon Sep 17 00:00:00 2001
From: Thomas Werschlein <thomas.werschlein@geo.uzh.ch>
Date: Thu, 30 Aug 2018 18:29:20 +0200
Subject: [PATCH] cifs: connect to servername instead of IP for IPC$ share
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Git-commit: 395a2076b4064f97d3fce03af15210ff2a7bb7f9
Patch-mainline: v4.19-rc3
References: bsc#1051510, bsc#1144333

This patch is required allows access to a Microsoft fileserver failover
cluster behind a 1:1 NAT firewall.

The change also provides stronger context for authentication and share
connection (see MS-SMB2 3.3.5.7 and MS-SRVS 3.1.6.8) as noted by
Tom Talpey, and addresses comments about the buffer size for the UNC
made by Aurélien Aptel.

Signed-off-by: Thomas Werschlein <thomas.werschlein@geo.uzh.ch>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Tom Talpey <ttalpey@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Acked-by: Paulo Alcantara <palcantara@suse.de>
---
 fs/cifs/connect.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index c832a8a1970a..7aa08dba4719 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2547,7 +2547,7 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb_vol *volume_info)
 	if (tcon == NULL)
 		return -ENOMEM;
 
-	snprintf(unc, sizeof(unc), "\\\\%s\\IPC$", ses->serverName);
+	snprintf(unc, sizeof(unc), "\\\\%s\\IPC$", ses->server->hostname);
 
 	/* cannot fail */
 	nls_codepage = load_nls_default();
-- 
2.16.4