Commit Graph

97 Commits

Author SHA1 Message Date
Steve French
c3ca78e217 smb3: pass mode bits into create calls
We need to populate an ACL (security descriptor open context)
on file and directory correct.  This patch passes in the
mode.  Followon patch will build the open context and the
security descriptor (from the mode) that goes in the open
context.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2019-09-26 02:06:42 -05:00
Ronnie Sahlberg
86e14e1205 cifs: prepare SMB2_Flush to be usable in compounds
Create smb2_flush_init() and smb2_flush_free() so we can use the flush command
in compounds.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Steve French
89a5bfa350 smb3: optimize open to not send query file internal info
We can cut one third of the traffic on open by not querying the
inode number explicitly via SMB3 query_info since it is now
returned on open in the qfid context.

This is better in multiple ways, and
speeds up file open about 10% (more if network is slow).

Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-07-18 17:44:13 -05:00
Steve French
153322f753 smb3: Fix enumerating snapshots to Azure
Some servers (see MS-SMB2 protocol specification
section 3.3.5.15.1) expect that the FSCTL enumerate snapshots
is done twice, with the first query having EXACTLY the minimum
size response buffer requested (16 bytes) which refreshes
the snapshot list (otherwise that and subsequent queries get
an empty list returned).  So had to add code to set
the maximum response size differently for the first snapshot
query (which gets the size needed for the second query which
contains the actual list of snapshots).

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org> # 4.19+
2019-04-01 14:33:34 -05:00
Ronnie Sahlberg
ccdc77a305 cifs: add SMB2_ioctl_init/free helpers to be used with compounding
Define an _init() and a _free() function for SMB2_init so that we will
be able to use it with compounds.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-14 19:32:35 -05:00
Ronnie Sahlberg
b0f6df737a cifs: cache FILE_ALL_INFO for the shared root handle
When we open the shared root handle also ask for FILE_ALL_INFORMATION since
we can do this at zero cost as part of a compound.
Cache this information as long as the lease is held and return and serve any
future requests from cache.

This allows us to serve "stat /<mountpoint>" directly from cache and avoid
a network roundtrip.  Since clients often want to do this quite a lot
this improve performance slightly.

As an example: xfstest generic/533 performs 43 stat operations on the root
of the share while it is run. Which are eliminated with this patch.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-03-14 19:32:35 -05:00
Ronnie Sahlberg
e77fe73c7e cifs: we can not use small padding iovs together with encryption
We can not append small padding buffers as separate iovs when encryption is
used. For this case we must flatten the request into a single buffer
containing both the data from all the iovs as well as the padding bytes.

This is at least needed for 4.20 as well due to compounding changes.

CC: Stable <stable@vger.kernel.org>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-12-31 00:58:52 -06:00
Ronnie Sahlberg
f9793b6fcc cifs: change smb2_query_eas to use the compound query-info helper
Reducing the number of network roundtrips improves the performance
of query xattrs

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-12-23 22:40:17 -06:00
Ronnie Sahlberg
271b9c0c80 smb3: Fix rmdir compounding regression to strict servers
Some servers require that the setinfo matches the exact size,
and in this case compounding changes introduced by
commit c2e0fe3f5a ("cifs: make rmdir() use compounding")
caused us to send 8 bytes (padded length) instead of 1 byte
(the size of the structure).  See MS-FSCC section 2.4.11.

Fixing this when we send a SET_INFO command for delete file
disposition, then ends up as an iov of a single byte but this
causes problems with SMB3 and encryption.

To avoid this, instead of creating a one byte iov for the disposition value
and then appending an additional iov with a 7 byte padding we now handle
this as a single 8 byte iov containing both the disposition byte as well as
the padding in one single buffer.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Paulo Alcantara <palcantara@suse.de>
2018-12-19 07:55:32 -06:00
Ronnie Sahlberg
f5b05d622a cifs: add IOCTL for QUERY_INFO passthrough to userspace
This allows userspace tools to query the raw info levels for cifs files
and process the response in userspace.
In particular this is useful for many of those data where there is no
corresponding native data structure in linux.
For example querying the security descriptor for a file and extract the
SIDs.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-10-23 21:16:05 -05:00
Ronnie Sahlberg
bb435512ce cifs: change SMB2_OP_RENAME and SMB2_OP_HARDLINK to use compounding
Get rid of smb2_open_op_close() as all operations are now migrated
to smb2_compound_op().

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-10-23 21:16:04 -05:00
Ronnie Sahlberg
3764cbd179 cifs: remove the is_falloc argument to SMB2_set_eof
We never pass is_falloc==true here anyway and if we ever need to support
is_falloc in the future, SMB2_set_eof is such a trivial wrapper around
send_set_info() that we can/should just create a differently named wrapper
for that new functionality.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-10-23 21:16:04 -05:00
Ronnie Sahlberg
dcbf910357 cifs: change SMB2_OP_SET_INFO to use compounding
Cuts number of network roundtrips significantly for some common syscalls

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-10-23 21:16:04 -05:00
Ronnie Sahlberg
c2e0fe3f5a cifs: make rmdir() use compounding
This and previous patches drop the number of roundtrips we need for rmdir()
from 6 to 2.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-10-23 21:16:04 -05:00
Ronnie Sahlberg
ba8ca11685 cifs: create helpers for SMB2_set_info_init/free()
so that we can use these later for compounded set-info calls.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-10-23 21:16:04 -05:00
Ronnie Sahlberg
c5a5f38f07 cifs: add a smb2_compound_op and change QUERY_INFO to use it
This turns most open/query-info/close patterns in cifs.ko
to become compounds.

This changes stat from using 3 roundtrips to just a single one.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-10-23 21:16:04 -05:00
Ronnie Sahlberg
730928c8f4 cifs: update smb2_queryfs() to use compounding
Change smb2_queryfs() to use a Create/QueryInfo/Close compound request.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2018-08-09 21:19:56 -05:00
Ronnie Sahlberg
1eb9fb5204 cifs: create SMB2_open_init()/SMB2_open_free() helpers.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2018-08-08 18:10:26 -05:00
Ronnie Sahlberg
296ecbae7f cifs: add SMB2_query_info_[init|free]()
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.com>
2018-08-08 18:08:47 -05:00
Ronnie Sahlberg
8eb4ecfab0 cifs: add SMB2_close_init()/SMB2_close_free()
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.com>
2018-08-08 16:49:08 -05:00
Ronnie Sahlberg
9da6ec7775 cifs: use a refcount to protect open/closing the cached file handle
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Cc: <stable@vger.kernel.org>
2018-08-07 14:20:22 -05:00
Steve French
0fdfef9aa7 smb3: simplify code by removing CONFIG_CIFS_SMB311
We really, really want to be encouraging use of secure dialects,
and SMB3.1.1 offers useful security features, and will soon
be the recommended dialect for many use cases. Simplify the code
by removing the CONFIG_CIFS_SMB311 ifdef so users don't disable
it in the build, and create compatibility and/or security issues
with modern servers - many of which have been supporting this
dialect for multiple years.

Also clarify some of the Kconfig text for cifs.ko about
SMB3.1.1 and current supported features in the module.

Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-08-07 14:15:56 -05:00
Steve French
2d30421783 smb3: add support for statfs for smb3.1.1 posix extensions
Output now matches expected stat -f output for all fields
except for Namelen and ID which were addressed in a companion
patch (which retrieves them from existing SMB3 mechanisms
and works whether POSIX enabled or not)

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2018-08-07 14:15:41 -05:00
Ronnie Sahlberg
81f39f951b cifs: fix SMB1 breakage
SMB1 mounting broke in commit 35e2cc1ba7
("cifs: Use correct packet length in SMB2_TRANSFORM header")
Fix it and also rename smb2_rqst_len to smb_rqst_len
to make it less unobvious that the function is also called from
CIFS/SMB1

Good job by Paulo reviewing and cleaning up Ronnie's original patch.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-07-05 13:48:24 -05:00
Paulo Alcantara
35e2cc1ba7 cifs: Use correct packet length in SMB2_TRANSFORM header
In smb3_init_transform_rq(), 'orig_len' was only counting the request
length, but forgot to count any data pages in the request.

Writing or creating files with the 'seal' mount option was broken.

In addition, do some code refactoring by exporting smb2_rqst_len() to
calculate the appropriate packet size and avoid duplicating the same
calculation all over the code.

The start of the io vector is either the rfc1002 length (4 bytes) or a
SMB2 header which is always > 4. Use this fact to check and skip the
rfc1002 length if requested.

Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-06-15 19:17:40 -05:00
Steve French
bea851b8ba smb3: Fix mode on mkdir on smb311 mounts
mkdir was not passing the mode on smb3.11 mounts with posix extensions

Signed-off-by: Steve French <stfrench@microsoft.com>
2018-06-15 02:38:08 -05:00
Ronnie Sahlberg
9d874c3655 cifs: fix a buffer leak in smb2_query_symlink
This leak was introduced in 91cb74f514 and caused us
to leak one small buffer for every symlink query.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-06-07 23:39:41 -05:00
Ronnie Sahlberg
e4dc31fe9a cifs: change smb2_get_data_area_len to take a smb2_sync_hdr as argument
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-05-31 21:30:51 -05:00
Ronnie Sahlberg
97ca176224 cifs: add a new SMB2_close_flags function
And make SMB2_close just a wrapper for SMB2_close_flags.
We need this as we will start to send SMB2_CLOSE pdus using special
flags.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-27 17:56:35 -05:00
Ronnie Sahlberg
9ec672bd17 cifs: update calc_size to take a server argument
and change the smb2 version to take heder_preamble_size into account
instead of hardcoding it as 4 bytes.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-27 17:56:35 -05:00
Steve French
3d4ef9a153 smb3: fix redundant opens on root
In SMB2/SMB3 unlike in cifs we unnecessarily open the root of the share
over and over again in various places during mount and path revalidation
and also in statfs.  This patch cuts redundant traffic (opens and closes)
by simply keeping the directory handle for the root around (and reopening
it as needed on reconnect), so query calls don't require three round
trips to copmlete - just one, and eases load on network, client and
server (on mount alone, cuts network traffic by more than a third).

Also add a new cifs mount parm "nohandlecache" to allow users whose
servers might have resource constraints (eg in case they have a server
with so many users connecting to it that this extra handle per mount
could possibly be a resource concern).

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-05-27 17:56:35 -05:00
Ronnie Sahlberg
91cb74f514 cifs: Change SMB2_open to return an iov for the error parameter
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2018-04-12 20:32:50 -05:00
Aurelien Aptel
8bd68c6e47 CIFS: implement v3.11 preauth integrity
SMB3.11 clients must implement pre-authentification integrity.

* new mechanism to certify requests/responses happening before Tree
  Connect.
* supersedes VALIDATE_NEGOTIATE
* fixes signing for SMB3.11

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-04-01 20:24:40 -05:00
Aurelien Aptel
5fcd7f3f96 CIFS: add sha512 secmech
* prepare for SMB3.11 pre-auth integrity
* enable sha512 when SMB311 is enabled in Kconfig
* add sha512 as a soft dependency

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-04-01 20:24:39 -05:00
Aurelien Aptel
63a83b861c CIFS: use tcon_ipc instead of use_ipc parameter of SMB2_ioctl
Since IPC now has a tcon object, the caller can just pass it. This
allows domain-based DFS requests to work with smb2+.

Link: https://bugzilla.samba.org/show_bug.cgi?id=12917
Fixes: 9d49640a21 ("CIFS: implement get_dfs_refer for SMB2+")
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2018-01-26 17:03:00 -06:00
Ronnie Sahlberg
7cb3def44c cifs: handle large EA requests more gracefully in smb2+
Update reading the EA using increasingly larger buffer sizes
until the response will fit in the buffer, or we exceed the
(arbitrary) maximum set to 64kb.

Without this change, a user is able to add more and more EAs using
setfattr until the point where the total space of all EAs exceed 2kb
at which point the user can no longer list the EAs at all
and getfattr will abort with an error.

The same issue still exists for EAs in SMB1.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reported-by: Xiaoli Feng <xifeng@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2017-10-18 11:52:39 -05:00
Ronnie Sahlberg
5517554e43 cifs: Add support for writing attributes on SMB2+
This adds support for writing extended attributes on SMB2+ shares.
Attributes can be written using the setfattr command.

RH-bz: 1110709

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2017-09-04 14:03:45 -05:00
Ronnie Sahlberg
95907fea4f cifs: Add support for reading attributes on SMB2+
SMB1 already has support to read attributes. This adds similar support
to SMB2+.

With this patch, tools such as 'getfattr' will now work with SMB2+ shares.

RH-bz: 1110709

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2017-09-04 14:03:41 -05:00
Shirish Pargaonkar
dac953401c cifs: prototype declaration and definition to set acl for smb 2 - 3 and cifsacl mount options
Modified current set info function to accommodate multiple info types and
additional information.

Added cifs acl specific function to invoke set info functionality.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2017-07-08 15:08:38 -05:00
Shirish Pargaonkar
42c493c16f cifs: prototype declaration and definition for smb 2 - 3 and cifsacl mount options
Add definition and declaration of function to get cifs acls when
mounting with smb version 2 onwards to 3.

Extend/Alter query info function to allocate and return
security descriptors within the response.

Not yet handling the error case when the size of security descriptors
in response to query exceeds SMB2_MAX_BUFFER_SIZE.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2017-07-05 19:51:04 -05:00
Sachin Prabhu
38bd49064a Handle mismatched open calls
A signal can interrupt a SendReceive call which result in incoming
responses to the call being ignored. This is a problem for calls such as
open which results in the successful response being ignored. This
results in an open file resource on the server.

The patch looks into responses which were cancelled after being sent and
in case of successful open closes the open fids.

For this patch, the check is only done in SendReceive2()

RH-bz: 1403319

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Cc: Stable <stable@vger.kernel.org>
2017-04-07 08:04:40 -05:00
Sachin Prabhu
ef65aaede2 smb2: Enforce sec= mount option
If the security type specified using a mount option is not supported,
the SMB2 session setup code changes the security type to RawNTLMSSP. We
should instead fail the mount and return an error.

The patch changes the code for SMB2 to make it similar to the code used
for SMB1. Like in SMB1, we now use the global security flags to select
the security method to be used when no security method is specified and
to return an error when the requested auth method is not available.

For SMB2, we also use ntlmv2 as a synonym for nltmssp.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2017-03-02 23:13:37 -06:00
Aurelien Aptel
51146625f3 CIFS: add use_ipc flag to SMB2_ioctl()
when set, use the session IPC tree id instead of the tid in the provided
tcon.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2017-03-01 22:26:11 -06:00
Pavel Shilovsky
4326ed2f6a CIFS: Decrypt and process small encrypted packets
Allow to decrypt transformed packets, find a corresponding mid
and process as usual further.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
2017-02-01 16:46:36 -06:00
Pavel Shilovsky
026e93dc0a CIFS: Encrypt SMB3 requests before sending
This change allows to encrypt packets if it is required by a server
for SMB sessions or tree connections.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
2017-02-01 16:46:36 -06:00
Pavel Shilovsky
53e0e11efe CIFS: Fix a possible memory corruption during reconnect
We can not unlock/lock cifs_tcp_ses_lock while walking through ses
and tcon lists because it can corrupt list iterator pointers and
a tcon structure can be released if we don't hold an extra reference.
Fix it by moving a reconnect process to a separate delayed work
and acquiring a reference to every tcon that needs to be reconnected.
Also do not send an echo request on newly established connections.

CC: Stable <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
2016-12-05 12:08:33 -08:00
Steve French
897fba1172 remove directory incorrectly tries to set delete on close on non-empty directories
Wrong return code was being returned on SMB3 rmdir of
non-empty directory.

For SMB3 (unlike for cifs), we attempt to delete a directory by
set of delete on close flag on the open. Windows clients set
this flag via a set info (SET_FILE_DISPOSITION to set this flag)
which properly checks if the directory is empty.

With this patch on smb3 mounts we correctly return
 "DIRECTORY NOT EMPTY"
on attempts to remove a non-empty directory.

Signed-off-by: Steve French <steve.french@primarydata.com>
CC: Stable <stable@vger.kernel.org>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
2016-05-17 14:09:44 -05:00
Steve French
373512ec5c Prepare for encryption support (first part). Add decryption and encryption key generation. Thanks to Metze for helping with this.
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <steve.french@primarydata.com>
2016-01-14 14:29:42 -06:00
Steve French
c22870ea2d mfsymlinks support for SMB2.1/SMB3. Part 2 query symlink
Adds support on SMB2.1 and SMB3 mounts for emulation of symlinks
via the "Minshall/French" symlink format already used for cifs
mounts when mfsymlinks mount option is used (and also used by Apple).
  http://wiki.samba.org/index.php/UNIX_Extensions#Minshall.2BFrench_symlinks
This second patch adds support to query them (recognize them as symlinks
and read them).  Third version of patch makes minor corrections
to error handling.

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
2014-10-16 15:20:20 -05:00
Steve French
5ab97578cb Add mfsymlinks support for SMB2.1/SMB3. Part 1 create symlink
Adds support on SMB2.1 and SMB3 mounts for emulation of symlinks
via the "Minshall/French" symlink format already used for cifs
mounts when mfsymlinks mount option is used (and also used by Apple).
http://wiki.samba.org/index.php/UNIX_Extensions#Minshall.2BFrench_symlinks
This first patch adds support to create them.  The next patch will
add support for recognizing them and reading them.  Although CIFS/SMB3
have other types of symlinks, in the many use cases they aren't
practical (e.g. either require cifs only mounts with unix extensions
to Samba, or require the user to be Administrator to Windows for SMB3).
This also helps enable running additional xfstests over SMB3 (since some
xfstests directly or indirectly require symlink support).

Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stefan Metzmacher <metze@samba.org>
2014-10-16 15:20:20 -05:00