From: Thomas Werschlein <thomas.werschlein@geo.uzh.ch>
Date: Thu, 30 Aug 2018 16:29:20 +0000 (+0200)
Subject: cifs: connect to servername instead of IP for IPC$ share
X-Git-Tag: v4.19~232^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=395a2076b4064f97d3fce03af15210ff2a7bb7f9;p=platform%2Fkernel%2Flinux-rpi.git

cifs: connect to servername instead of IP for IPC$ share

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>
---

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index c832a8a..7aa08db 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();