If we negotiate SMB 2.1 and higher version of the protocol and
a server supports large write buffer size, we need to consume 1
credit per 65536 bytes. So, we need to know how many credits
we have and obtain the required number of them before constructing
a writedata structure in writepages and iovec write.
Reviewed-by: NShirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

If a server change maximum buffer size for write (wsize) requests
on reconnect we can fail on repeating with a big size buffer on
-EAGAIN error in iovec write. Fix this by checking wsize all the
time before repeating request in iovec write.
Reviewed-by: NShirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

The functionality provided by free_rsp_buf() is duplicated in a number
of places. Replace these instances with a call to free_rsp_buf().
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NShirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Reviewed-by: NShirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Clarify comments for create contexts which we do send,
and fix typo in one create context definition and add
newer SMB3 create contexts to the list.
Signed-off-by: NSteve French <smfrench@gmail.com>

ClientGUID must be zero for SMB2.02 dialect.  See section 2.2.3
of MS-SMB2. For SMB2.1 and later it must be non-zero.
Signed-off-by: NSteve French <smfrench@gmail.com>
CC: Sachin Prabhu <sprabhu@redhat.com>

When mounting from a Windows 2012R2 server, we hit the following
problem:
1) Mount with any of the following versions - 2.0, 2.1 or 3.0
2) unmount
3) Attempt a mount again using a different SMB version >= 2.0.

You end up with the following failure:
Status code returned 0xc0000203 STATUS_USER_SESSION_DELETED
CIFS VFS: Send error in SessSetup = -5
CIFS VFS: cifs_mount failed w/return code = -5

I cannot reproduce this issue using a Windows 2008 R2 server.

This appears to be caused because we use the same client guid for the
connection on first mount which we then disconnect and attempt to mount
again using a different protocol version. By generating a new guid each
time a new connection is Negotiated, we avoid hitting this problem.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

In SMB2_set_compression(), the "res_key" variable is only initialized to NULL
and later kfreed. It is therefore useless and should be removed.

Found with the following semantic patch:

<smpl>
@@
identifier foo;
identifier f;
type T;
@@
* f(...) {
...
* T *foo = NULL;
... when forall
    when != foo
* kfree(foo);
...
}
</smpl>
Signed-off-by: NCyril Roelandt <tipecaml@gmail.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

SMB3 servers can respond with MaxTransactSize of more than 4M
that can cause a memory allocation error returned from kmalloc
in a lock codepath. Also the client doesn't support multicredit
requests now and allows buffer sizes of 65536 bytes only. Set
MaxTransactSize to this maximum supported value.

Cc: stable@vger.kernel.org # 3.7+
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

In the event that a send fails in an uncached write, or we end up
needing to reissue it (-EAGAIN case), we'll kfree the wdata but
the pages currently leak.

Fix this by adding a new kref release routine for uncached writedata
that releases the pages, and have the uncached codepaths use that.

[original patch by Jeff modified to fix minor formatting problems]
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <smfrench@gmail.com>

When we are running SMB3 or SMB3.02 connections which are signed
we need to validate the protocol negotiation information,
to ensure that the negotiate protocol response was not tampered with.

Add the missing FSCTL which is sent at mount time (immediately after
the SMB3 Tree Connect) to validate that the capabilities match
what we think the server sent.

"Secure dialect negotiation is introduced in SMB3 to protect against
man-in-the-middle attempt to downgrade dialect negotiation.
The idea is to prevent an eavesdropper from downgrading the initially
negotiated dialect and capabilities between the client and the server."

For more explanation see 2.2.31.4 of MS-SMB2 or
http://blogs.msdn.com/b/openspecification/archive/2012/06/28/smb3-secure-dialect-negotiation.aspxReviewed-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <smfrench@gmail.com>

Remove an unneeded goto (and also was duplicated goto target name).
Signed-off-by: NSteve French <smfrench@gmail.com>

This third version of the patch, incorparating feedback from David Disseldorp
extends the ability of copychunk (refcopy) over smb2/smb3 mounts to
handle servers with smaller than usual maximum chunk sizes
and also fixes it to handle files bigger than the maximum chunk sizes

In the future this can be extended further to handle sending
multiple chunk requests in on SMB2 ioctl request which will
further improve performance, but even with one 1MB chunk per
request the speedup on cp is quite large.
Reviewed-by: NDavid Disseldorp <ddiss@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

We do not support SMB3 encryption yet, warn if server responds
that SMB3 encryption is mandatory.
Signed-off-by: NSteve French <smfrench@gmail.com>

Patch 2 of the copy chunk series (the final patch will
use these to handle copies of files larger than the chunk size.

We set the same defaults that Windows and Samba expect for
CopyChunk.
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NDavid Disseldorp <ddiss@samba.org>

In SMB3 it is now possible to query the file system
alignment info, and the preferred (for performance)
sector size and whether the underlying disk
has no seek penalty (like SSD).

Query this information at mount time for SMB3,
and make it visible in /proc/fs/cifs/DebugData
for debugging purposes.

This alignment information and preferred sector
size info will be helpful for the copy offload
patches to setup the right chunks in the CopyChunk
requests.   Presumably the knowledge that the
underlying disk is SSD could also help us
make better readahead and writebehind
decisions (something to look at in the future).
Signed-off-by: NSteve French <smfrench@gmail.com>

Currently SMB2 and SMB3 mounts do not query the device information at mount time
from the server as is done for cifs.  These can be useful for debugging.
This is a minor patch, that extends the previous one (which added ability to
query file system attributes at mount time - this returns the device
characteristics - also via in /proc/fs/cifs/DebugData)
Signed-off-by: NSteve French <smfrench@gmail.com>

Currently SMB2 and SMB3 mounts do not query the file system attributes
from the server at mount time as is done for cifs.  These can be useful for debugging.
Signed-off-by: NSteve French <smfrench@gmail.com>

Allow cifs/smb2/smb3 to return whether or not a file is compressed
via lsattr, and allow SMB2/SMB3 to set the per-file compression
flag ("chattr +c filename" on an smb3 mount).

Windows users often set the compressed flag (it can be
done from the desktop and file manager).  David Disseldorp
has patches to Samba server to support this (at least on btrfs)
which are complementary to this
Signed-off-by: NSteve French <smfrench@gmail.com>

We were off by one calculating the length of ioctls in some cases
because the protocol specification for SMB2 ioctl includes a mininum
one byte payload but not all SMB2 ioctl requests actually have
a data buffer to send. We were also not zeroing out the
return buffer (in case of error this is helpful).
Signed-off-by: NSteve French <smfrench@gmail.com>

Do not send SMB2 Logoff command when reconnecting, the way smb1
code base works.

Also, no need to wait for a credit for an echo command when one is already
in flight.

Without these changes, umount command hangs if the server is unresponsive
e.g. hibernating.
Signed-off-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@us.ibm.com>

that force a client to purge cache pages when a server requests it.
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

to make adding new types of lease buffers easier.
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

and separate smb20_operations struct.
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

    Switch smb2 code to use per session session key and smb3 code to
    use per session signing key instead of per connection key to
    generate signatures.

    For that, we need to find a session to fetch the session key to
    generate signature to match for every request and response packet.

    We also forgo checking signature for a session setup response
    from the server.
Acked-by: NJeff Layton <jlayton@samba.org>
Signed-off-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Add a variable specific to NTLMSSP authentication to determine
whether to exchange keys during negotiation and authentication phases.

Since session key for smb1 is per smb connection, once a very first
sesion is established, there is no need for key exchange during
subsequent session setups. As a result, smb1 session setup code sets this
variable as false.

Since session key for smb2 and smb3 is per smb connection, we need to
exchange keys to generate session key for every sesion being established.
As a result, smb2/3 session setup code sets this variable as true.
Acked-by: NJeff Layton <jlayton@samba.org>
Signed-off-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Move the post (successful) session setup code to respective dialect routines.

For smb1, session key is per smb connection.
For smb2/smb3, session key is per smb session.

If client and server do not require signing, free session key for smb1/2/3.

If client and server require signing
  smb1 - Copy (kmemdup) session key for the first session to connection.
         Free session key of that and subsequent sessions on this connection.
  smb2 - For every session, keep the session key and free it when the
         session is being shutdown.
  smb3 - For every session, generate the smb3 signing key using the session key
         and then free the session key.

There are two unrelated line formatting changes as well.
Reviewed-by: NJeff Layton <jlayton@samba.org>
Signed-off-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Convert cpu_to_le32(le32_to_cpu(E1) + E2) to use le32_add_cpu().
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

that allows to access files through symlink created on a server.
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

Fix endian warning:

  CHECK   fs/cifs/smb2pdu.c
fs/cifs/smb2pdu.c:1068:40: warning: incorrect type in assignment (different base types)
fs/cifs/smb2pdu.c:1068:40:    expected restricted __le32 [usertype] Next
fs/cifs/smb2pdu.c:1068:40:    got unsigned long
Signed-off-by: NSteve French <smfrench@gmail.com>

On reconnects, we need to reopen file and then obtain all byte-range
locks held by the client. SMB2 protocol provides feature to make
this process atomic by reconnecting to the same file handle
with all it's byte-range locks. This patch adds this capability
for SMB2 shares.
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteven French <steven@steven-GA-970A-DS3.(none)>

to prepare it for further durable handle reconnect processing.
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteven French <steven@steven-GA-970A-DS3.(none)>

by passing durable context together with a handle caching lease or
batch oplock.
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteven French <steven@steven-GA-970A-DS3.(none)>

to make it easier to add other create context further.
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteven French <steven@steven-GA-970A-DS3.(none)>

by passing a filename to a separate iovec regardless of its length.
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteven French <steven@steven-GA-970A-DS3.(none)>

and eliminated unused file_attribute parms of SMB2_open.
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteven French <steven@steven-GA-970A-DS3.(none)>

to prevent missing RqLs context if it's not the first one.
Signed-off-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteven French <steven@steven-GA-970A-DS3.(none)>

If we would set SMB2_FLAGS_DFS_OPERATIONS on open we also would have
to pass the path on the Open SMB prefixed by \\server\share.
Not sure when we would need to do the augmented path (if ever) and
setting this flag breaks the SMB2 open operation since it is
illegal to send an empty path name (without \\server\share prefix)
when the DFS flag is set in the SMB open header. We could
consider setting the flag on all operations other than open
but it is safer to net set it for now.
Signed-off-by: NSteve French <smfrench@gmail.com>

Dan Carpenter wrote:

The patch 7f420cee8bd6: "[CIFS] Charge at least one credit, if server
says that it supports multicredit" from Jun 23, 2013, leads to the
following Smatch complaint:

fs/cifs/smb2pdu.c:120 smb2_hdr_assemble()
         warn: variable dereferenced before check 'tcon->ses' (see line 115)

CC: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NSteve French <smfrench@gmail.com>