When mounting a Windows share that is the root of a drive (eg. C$)
the server does not return . and .. directory entries. This results in
the smb2 code path erroneously skipping the 2 first entries.
Pseudo-code of the readdir() code path:
cifs_readdir(struct file, struct dir_context)
initiate_cifs_search <-- if no reponse cached yet
server->ops->query_dir_first
dir_emit_dots
dir_emit <-- adds "." and ".." if we're at pos=0
find_cifs_entry
initiate_cifs_search <-- if pos < start of current response
(restart search)
server->ops->query_dir_next <-- if pos > end of current response
(fetch next search res)
for(...) <-- loops over cur response entries
starting at pos
cifs_filldir <-- skip . and .., emit entry
cifs_fill_dirent
dir_emit
pos++
A) dir_emit_dots() always adds . & ..
and sets the current dir pos to 2 (0 and 1 are done).
Therefore we always want the index_to_find to be 2 regardless of if
the response has . and ..
B) smb1 code initializes index_of_last_entry with a +2 offset
in cifssmb.c CIFSFindFirst():
psrch_inf->index_of_last_entry = 2 /* skip . and .. */ +
psrch_inf->entries_in_buffer;
Later in find_cifs_entry() we want to find the next dir entry at pos=2
as a result of (A)
first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
cfile->srch_inf.entries_in_buffer;
This var is the dir pos that the first entry in the buffer will
have therefore it must be 2 in the first call.
If we don't offset index_of_last_entry by 2 (like in (B)),
first_entry_in_buffer=0 but we were instructed to get pos=2 so this
code in find_cifs_entry() skips the 2 first which is ok for non-root
shares, as it skips . and .. from the response but is not ok for root
shares where the 2 first are actual files
pos_in_buf = index_to_find - first_entry_in_buffer;
// pos_in_buf=2
// we skip 2 first response entries :(
for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
/* go entry by entry figuring out which is first */
cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
cfile->srch_inf.info_level);
}
C) cifs_filldir() skips . and .. so we can safely ignore them for now.
Sample program:
int main(int argc, char **argv)
{
const char *path = argc >= 2 ? argv[1] : ".";
DIR *dh;
struct dirent *de;
printf("listing path <%s>\n", path);
dh = opendir(path);
if (!dh) {
printf("opendir error %d\n", errno);
return 1;
}
while (1) {
de = readdir(dh);
if (!de) {
if (errno) {
printf("readdir error %d\n", errno);
return 1;
}
printf("end of listing\n");
break;
}
printf("off=%lu <%s>\n", de->d_off, de->d_name);
}
return 0;
}
Before the fix with SMB1 on root shares:
<.> off=1
<..> off=2
<$Recycle.Bin> off=3
<bootmgr> off=4
and on non-root shares:
<.> off=1
<..> off=4 <-- after adding .., the offsets jumps to +2 because
<2536> off=5 we skipped . and .. from response buffer (C)
<411> off=6 but still incremented pos
<file> off=7
<fsx> off=8
Therefore the fix for smb2 is to mimic smb1 behaviour and offset the
index_of_last_entry by 2.
Test results comparing smb1 and smb2 before/after the fix on root
share, non-root shares and on large directories (ie. multi-response
dir listing):
PRE FIX
=======
pre-1-root VS pre-2-root:
ERR pre-2-root is missing [bootmgr, $Recycle.Bin]
pre-1-nonroot VS pre-2-nonroot:
OK~ same files, same order, different offsets
pre-1-nonroot-large VS pre-2-nonroot-large:
OK~ same files, same order, different offsets
POST FIX
========
post-1-root VS post-2-root:
OK same files, same order, same offsets
post-1-nonroot VS post-2-nonroot:
OK same files, same order, same offsets
post-1-nonroot-large VS post-2-nonroot-large:
OK same files, same order, same offsets
REGRESSION?
===========
pre-1-root VS post-1-root:
OK same files, same order, same offsets
pre-1-nonroot VS post-1-nonroot:
OK same files, same order, same offsets
BugLink: https://bugzilla.samba.org/show_bug.cgi?id=13107
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Paulo Alcantara <palcantara@suse.deR>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Although servers will typically ignore unsupported features,
we should advertise the support for directory leases (as
Windows e.g. does) in the negotiate protocol capabilities we
pass to the server, and should check for the server capability
(CAP_DIRECTORY_LEASING) before sending a lease request for an
open of a directory. This will prevent us from accidentally
sending directory leases to SMB2.1 or SMB2 server for example.
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
When "backup intent" is requested on the mount (e.g. backupuid or
backupgid mount options), the corresponding flag needs to be set
on opens of directories (and files) but was missing in some
places causing access denied trying to enumerate and backup
servers.
Fixes kernel bugzilla #200953https://bugzilla.kernel.org/show_bug.cgi?id=200953
Reported-and-tested-by: <whh@rubrik.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
We were missing the methods for get_acl and friends for the 3.11
dialect.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
When enumerating snapshots, the last few bytes of the final
snapshot could be left off since we were miscalculating the
length returned (leaving off the sizeof struct SRV_SNAPSHOT_ARRAY)
See MS-SMB2 section 2.2.32.2. In addition fixup the length used
to allow smaller buffer to be passed in, in order to allow
returning the size of the whole snapshot array more easily.
Sample userspace output with a kernel patched with this
(mounted to a Windows volume with two snapshots).
Before this patch, the second snapshot would be missing a
few bytes at the end.
~/cifs-2.6# ~/enum-snapshots /mnt/file
press enter to issue the ioctl to retrieve snapshot information ...
size of snapshot array = 102
Num snapshots: 2 Num returned: 2 Array Size: 102
Snapshot 0:@GMT-2018.06.30-19.34.17
Snapshot 1:@GMT-2018.06.30-19.33.37
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
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>
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>
These are used for SMB3 encryption and compounded requests.
Update these functions and the other functions related to SMB3 encryption to
take an array of requests.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
We were only displaying bytes_read and bytes_written in cifs
stats, fix smb3 stats to also display them. Sample output
with this patch:
cat /proc/fs/cifs/Stats:
CIFS Session: 1
Share (unique mount targets): 2
SMB Request/Response Buffer: 1 Pool size: 5
SMB Small Req/Resp Buffer: 1 Pool size: 30
Operations (MIDs): 0
0 session 0 share reconnects
Total vfs operations: 94 maximum at one time: 2
1) \\localhost\test
SMBs: 214
Bytes read: 502092 Bytes written: 31457286
TreeConnects: 1 total 0 failed
TreeDisconnects: 0 total 0 failed
Creates: 52 total 3 failed
Closes: 48 total 0 failed
Flushes: 0 total 0 failed
Reads: 17 total 0 failed
Writes: 31 total 0 failed
...
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CONFIG_CIFS_STATS should always be enabled as Pavel recently
noted. Simple statistics are not a significant performance hit,
and removing the ifdef simplifies the code slightly.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
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>
In debugging reconnection problems, want to be able to more easily
trace cases in which the server has marked the SMB3 session
expired or deleted (to distinguish from timeout cases).
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Remove counters from the per-tree connection /proc/fs/cifs/Stats
output that will always be zero (since they are not per-tcon ops)
ie SMB3 Negotiate, SessionSetup, Logoff, Echo, Cancel.
Also clarify "sent" to be "total" per-Pavel's suggestion
(since this "total" includes total for all operations that we try to
send whether or not succesffully sent). Sample output below:
Resources in use
CIFS Session: 1
Share (unique mount targets): 2
SMB Request/Response Buffer: 1 Pool size: 5
SMB Small Req/Resp Buffer: 1 Pool size: 30
Operations (MIDs): 0
1 session 2 share reconnects
Total vfs operations: 23 maximum at one time: 2
1) \\localhost\test
SMBs: 45
TreeConnects: 2 total 0 failed
TreeDisconnects: 0 total 0 failed
Creates: 13 total 2 failed
Closes: 9 total 0 failed
Flushes: 0 total 0 failed
Reads: 0 total 0 failed
Writes: 1 total 0 failed
Locks: 0 total 0 failed
IOCTLs: 3 total 1 failed
QueryDirectories: 4 total 2 failed
ChangeNotifies: 0 total 0 failed
QueryInfos: 10 total 0 failed
SetInfos: 3 total 0 failed
OplockBreaks: 0 sent 0 failed
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Some servers, like Samba, don't support the fsctl for
query_network_interface_info so don't log a noisy warning
message on mount for this by default unless the error is more serious.
Lower the error to an FYI level so it does not get logged by
default.
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
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>
Fil in the correct namelen (typically 255 not 4096) in the
statfs response and also fill in a reasonably unique fsid
(in this case taken from the volume id, and the creation time
of the volume).
In the case of the POSIX statfs all fields are now filled in,
and in the case of non-POSIX mounts, all fields are filled
in which can be.
Signed-off-by: Steve French <stfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
This is not really a runtime issue but Smatch complains that:
fs/cifs/smb2ops.c:1740 smb2_query_symlink()
error: uninitialized symbol 'resp_buftype'.
The warning is right that it can be uninitialized... Also "err_buf"
would be NULL at this point and we're not supposed to pass NULLs to
free_rsp_buf() or it might trigger some extra output if we turn on
debugging.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
This patch fixes a memory leak when doing a setxattr(2) in SMB2+.
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
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>
With protocol version 2.0 mounts we have seen crashes with corrupt mid
entries. Either the server->pending_mid_q list becomes corrupt with a
cyclic reference in one element or a mid object fetched by the
demultiplexer thread becomes overwritten during use.
Code review identified a race between the demultiplexer thread and the
request issuing thread. The demultiplexer thread seems to be written
with the assumption that it is the sole user of the mid object until
it calls the mid callback which either wakes the issuer task or
deletes the mid.
This assumption is not true because the issuer task can be woken up
earlier by a signal. If the demultiplexer thread has proceeded as far
as setting the mid_state to MID_RESPONSE_RECEIVED then the issuer
thread will happily end up calling cifs_delete_mid while the
demultiplexer thread still is using the mid object.
Inserting a delay in the cifs demultiplexer thread widens the race
window and makes reproduction of the race very easy:
if (server->large_buf)
buf = server->bigbuf;
+ usleep_range(500, 4000);
server->lstrp = jiffies;
To resolve this I think the proper solution involves putting a
reference count on the mid object. This patch makes sure that the
demultiplexer thread holds a reference until it has finished
processing the transaction.
Cc: stable@vger.kernel.org
Signed-off-by: Lars Persson <larper@axis.com>
Acked-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
Since the rfc1002 generation was moved down to __smb_send_rqst(),
the transform header is now in rqst->rq_iov[0].
Correctly assign the transform header pointer in crypt_message().
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Move the generation of the 4 byte length field down the stack and
generate it immediately before we start writing the data to the socket.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Use a read lease for the cached root fid so that we can detect
when the content of the directory changes (via a break) at which time
we close the handle. On next access to the root the handle will be reopened
and cached again.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
The smb2 hdr is now in iov 1
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Encryption function needs to read data starting page offset from input
buffer.
This doesn't affect decryption path since it allocates its own page
buffers.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
With offset defined in rdata, transport functions need to look at this
offset when reading data into the correct places in pages.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Since header_preamble_size is 0 for SMB2+ we can remove it in those
code paths that are only invoked from SMB2.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
struct smb2_hdr is now just a wrapper for smb2_sync_hdr.
We can thus get rid of smb2_hdr completely and access the sync header directly.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Handle this additional status in the same way as SESSION_EXPIRED.
Signed-off-by: Mark Syms <mark.syms@citrix.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Separate out all the 4 byte rfc1002 headers so that they are no longer
part of the SMB2 header structures to prepare for future work to add
compounding support.
Update the smb3 transform header processing that we no longer have
a rfc1002 header at the start of this structure.
Update smb2_readv_callback to accommodate that the first iovector in the
response is no the smb2 header and no longer a rfc1002 header.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When loooking at the logs for the new trace-cmd tracepoints for cifs,
it would help to know which tid is for which share (UNC name) so
update /proc/fs/cifs/DebugData to display the tid.
Also display Maximal Access which was missing as well.
Now the entry for typical entry for a tcon (in proc/fs/cifs/) looks
like:
1) \\localhost\test Mounts: 1 DevInfo: 0x20 Attributes: 0x1006f
PathComponentMax: 255 Status: 1 type: DISK
Share Capabilities: None Aligned, Partition Aligned, Share Flags: 0x0
tid: 0xe0632a55 Optimal sector size: 0x200 Maximal Access: 0x1f01ff
Signed-off-by: Steve French <smfrench@gmail.com>
Fix a few cases where we were not freeing the xid which led to
active requests being non-zero at unmount time.
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
In SMB2_open(), if we got a lease we need to store this in the fid structure
or else we will never be able to map a lease break back to which file/fid
it applies to.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Previous patches "cifs: update calc_size to take a server argument"
and
"cifs: add server argument to the dump_detail method"
were broken if CONFIG_CIFS_DEBUG2 enabled
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Ronnie Sahlberg <lsahlber@redhat.com>
We need a struct TCP_Server_Info *server to this method as it calls
calc_size. The calc_size method will soon be changed to also
take a server argument.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
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>
As per listxattr(2):
On success, a nonnegative number is returned indicating the size
of the extended attribute name list. On failure, -1 is returned
and errno is set appropriately.
In SMB1, when the server returns an empty EA list through a listxattr(),
it will correctly return 0 as there are no EAs for the given file.
However, in SMB2+, it returns -ENODATA in listxattr() which is wrong since
the request and response were sent successfully, although there's no actual
EA for the given file.
This patch fixes listxattr() for SMB2+ by returning 0 in cifs_listxattr()
when the server returns an empty list of EAs.
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
SMB server will not sign data transferred through RDMA read/write. When
signing is used, it's a good idea to have all the data signed.
In this case, use RDMA send/recv for all data transfers. This will degrade
performance as this is not generally configured in RDMA environemnt. So
warn the user on signing and RDMA send/recv.
Signed-off-by: Long Li <longli@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <smfrench@gmail.com>
The current code null checks variable err_buf, which is always null
when it is checked, hence utf16_path is free'd and the function
returns -ENOENT everytime it is called, making it impossible for the
execution path to reach the following code:
err_buf = err_iov.iov_base;
Fix this by null checking err_iov.iov_base instead of err_buf. Also,
notice that err_buf no longer needs to be initialized to NULL.
Addresses-Coverity-ID: 1467876 ("Logically dead code")
Fixes: 2d636199e400 ("cifs: Change SMB2_open to return an iov for the error parameter")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
and get rid of some get_rfc1002_length() in smb2
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
This variable is set to 4 for all protocol versions and replaces
the hardcoded constant 4 throughought the code.
This will later be updated to reflect whether a response packet
has a 4 byte length preamble or not once we start removing this
field from the SMB2+ dialects.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
