d9deef0a3f
With the change to ignore the unc= and prefixpath= mount options, there
is no longer any need to add them to the options string when mounting.
By the same token, we now need to build a device name that includes the
prefixpath when mounting.
To make things neater, the delimiters on the devicename are changed
to '/' since that's preferred when mounting anyway.
v2: fix some comments and don't bother looking at whether there is
a prepath in the ref->node_name when deciding whether to pass
a prepath to cifs_build_devname.
v3: rebase on top of potential buffer overrun fix for stable
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
99 lines
2.8 KiB
C
99 lines
2.8 KiB
C
/*
|
|
* fs/cifs/dns_resolve.c
|
|
*
|
|
* Copyright (c) 2007 Igor Mammedov
|
|
* Author(s): Igor Mammedov (niallain@gmail.com)
|
|
* Steve French (sfrench@us.ibm.com)
|
|
* Wang Lei (wang840925@gmail.com)
|
|
* David Howells (dhowells@redhat.com)
|
|
*
|
|
* Contains the CIFS DFS upcall routines used for hostname to
|
|
* IP address translation.
|
|
*
|
|
* This library is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU Lesser General Public License as published
|
|
* by the Free Software Foundation; either version 2.1 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
|
|
* the GNU Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public License
|
|
* along with this library; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <linux/slab.h>
|
|
#include <linux/dns_resolver.h>
|
|
#include "dns_resolve.h"
|
|
#include "cifsglob.h"
|
|
#include "cifsproto.h"
|
|
#include "cifs_debug.h"
|
|
|
|
/**
|
|
* dns_resolve_server_name_to_ip - Resolve UNC server name to ip address.
|
|
* @unc: UNC path specifying the server (with '/' as delimiter)
|
|
* @ip_addr: Where to return the IP address.
|
|
*
|
|
* The IP address will be returned in string form, and the caller is
|
|
* responsible for freeing it.
|
|
*
|
|
* Returns length of result on success, -ve on error.
|
|
*/
|
|
int
|
|
dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
|
|
{
|
|
struct sockaddr_storage ss;
|
|
const char *hostname, *sep;
|
|
char *name;
|
|
int len, rc;
|
|
|
|
if (!ip_addr || !unc)
|
|
return -EINVAL;
|
|
|
|
len = strlen(unc);
|
|
if (len < 3) {
|
|
cifs_dbg(FYI, "%s: unc is too short: %s\n", __func__, unc);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Discount leading slashes for cifs */
|
|
len -= 2;
|
|
hostname = unc + 2;
|
|
|
|
/* Search for server name delimiter */
|
|
sep = memchr(hostname, '/', len);
|
|
if (sep)
|
|
len = sep - hostname;
|
|
else
|
|
cifs_dbg(FYI, "%s: probably server name is whole unc: %s\n",
|
|
__func__, unc);
|
|
|
|
/* Try to interpret hostname as an IPv4 or IPv6 address */
|
|
rc = cifs_convert_address((struct sockaddr *)&ss, hostname, len);
|
|
if (rc > 0)
|
|
goto name_is_IP_address;
|
|
|
|
/* Perform the upcall */
|
|
rc = dns_query(NULL, hostname, len, NULL, ip_addr, NULL);
|
|
if (rc < 0)
|
|
cifs_dbg(FYI, "%s: unable to resolve: %*.*s\n",
|
|
__func__, len, len, hostname);
|
|
else
|
|
cifs_dbg(FYI, "%s: resolved: %*.*s to %s\n",
|
|
__func__, len, len, hostname, *ip_addr);
|
|
return rc;
|
|
|
|
name_is_IP_address:
|
|
name = kmalloc(len + 1, GFP_KERNEL);
|
|
if (!name)
|
|
return -ENOMEM;
|
|
memcpy(name, hostname, len);
|
|
name[len] = 0;
|
|
cifs_dbg(FYI, "%s: unc is IP, skipping dns upcall: %s\n",
|
|
__func__, name);
|
|
*ip_addr = name;
|
|
return 0;
|
|
}
|