We have a bit of a problem with the uid= option. The basic issue is that
it means too many things and has too many side-effects.

It's possible to allow an unprivileged user to mount a filesystem if the
user owns the mountpoint, /bin/mount is setuid root, and the mount is
set up in /etc/fstab with the "user" option.

When doing this though, /bin/mount automatically adds the "uid=" and
"gid=" options to the share. This is fortunate since the correct uid=
option is needed in order to tell the upcall what user's credcache to
use when generating the SPNEGO blob.

On a mount without unix extensions this is fine -- you generally will
want the files to be owned by the "owner" of the mount. The problem
comes in on a mount with unix extensions. With those enabled, the
uid/gid options cause the ownership of files to be overriden even though
the server is sending along the ownership info.

This means that it's not possible to have a mount by an unprivileged
user that shows the server's file ownership info. The result is also
inode permissions that have no reflection at all on the server. You
simply cannot separate ownership from the mode in this fashion.

This behavior also makes MultiuserMount option less usable. Once you
pass in the uid= option for a mount, then you can't use unix ownership
info and allow someone to share the mount.

While I'm not thrilled with it, the only solution I can see is to stop
making uid=/gid= force the overriding of ownership on mounts, and to add
new mount options that turn this behavior on.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

For IPv6 the userspace mount helper sends an address in the "ip="
option.  This check fails if the length is > 35 characters. I have no
idea where the magic 35 character limit came from, but it's clearly not
enough for IPv6. Fix it by making it use the INET6_ADDRSTRLEN #define.

While we're at it, use the same #define for the address length in SPNEGO
upcalls.
Reported-by: NCharles R. Anderson <cra@wpi.edu>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

The current default file mode is 02767 and dir mode is 0777. This is
extremely "loose". Given that CIFS is a single-user protocol, these
permissions allow anyone to use the mount -- in effect, giving anyone on
the machine access to the credentials used to mount the share.

Change this by making the default permissions restrict write access to
the default owner of the mount. Give read and execute permissions to
everyone else. These are the same permissions that VFAT mounts get by
default so there is some precedent here.

Note that this patch also removes the mandatory locking flags from the
default file_mode. After having looked at how these flags are used by
the kernel, I don't think that keeping them as the default offers any
real benefit. That flag combination makes it so that the kernel enforces
mandatory locking.

Since the server is going to do that for us anyway, I don't think we
want the client to enforce this by default on applications that just
want advisory locks. Anyone that does want this behavior can always
enable it by setting the file_mode appropriately.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

On mount, "sec=ntlmssp" can now be specified to allow
"rawntlmssp" security to be enabled during
CIFS session establishment/authentication (ntlmssp used to
require specifying krb5 which was counterintuitive).
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Remove dead NTLMSSP support from connect.c prior to addition of
the new code to replace it.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Removes two sparse CHECK_ENDIAN warnings from Jeffs earlier patch,
and removes the dead readlink code (after noting where in
findfirst we will need to add something like that in the future
to handle the newly discovered unexpected error on FindFirst of NTFS symlinks.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

In most cases, cifs_strndup is converting from Unicode (UCS2 / UTF-32) to
the configured local code page for the Linux mount (usually UTF8), so
Jeff suggested that to make it more clear that cifs_strndup is doing
a conversion not just memory allocation and copy, rename the function
to including "from_ucs" (ie Unicode)
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Added loop check when mounting DFS tree. mount will fail with
ELOOP if referral walks exceed MAX_NESTED_LINK count.
Signed-off-by: NIgor Mammedov <niallain@gmail.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Two years ago, when the session setup code in cifs was rewritten and moved
to fs/cifs/sess.c, we were asked to keep the old code for a release or so
(which could be reenabled at runtime) since it was such a large change and
because the asn (SPNEGO) and NTLMSSP code was not rewritten and needed to
be. This was useful to avoid regressions, but is long overdue to be removed.
Now that the Kerberos (asn/spnego) code is working in fs/cifs/sess.c,
and the NTLMSSP code moved (NTLMSSP blob setup be rewritten with the
next patch in this series) quite a bit of dead code from fs/cifs/connect.c
now can be removed.

This old code should have been removed last year, but the earlier krb5
patches did not move/remove the NTLMSSP code which we had asked to
be done first.  Since no one else volunteered, I am doing it now.

It is extremely important that we continue to examine the documentation
for this area, to make sure our code continues to be uptodate with
changes since Windows 2003.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

This pointer isn't used again after this point. It's also not updated in
the ascii case, so there's no need to update it here.
Pointed-out-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

...to make it easier to find problems in this area in the future.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

The buffer for this was resized recently to fix a bug. It's still
possible however that a malicious server could overflow this field
by sending characters in it that are >2 bytes in the local charset.
Double the size of the buffer to account for this possibility.

Also get rid of some really strange and seemingly pointless NULL
termination. It's NULL terminating the string in the source buffer,
but by the time that happens, we've already copied the string.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

Allows to mount share on a server that returns -EREMOTE
 at the tree connect stage or at the check on a full path
 accessibility.
Signed-off-by: NIgor Mammedov <niallain@gmail.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Remove some pointless conditionals before kfree().
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

CIFS can allocate a few bytes to little for the nativeFileSystem field
during tree connect response processing during mount.  This can result
in a "Redzone overwritten" message to be logged.
Signed-off-by: NSridhar Vinay <vinaysridhar@in.ibm.com>
Acked-by: NShirish Pargaonkar <shirishp@us.ibm.com>
CC: Stable <stable@kernel.org>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

If this mount option is set, when an application does an
fsync call then the cifs client does not send an SMB Flush
to the server (to force the server to write all dirty data
for this file immediately to disk), although cifs still sends
all dirty (cached) file data to the server and waits for the
server to respond to the write write.  Since SMB Flush can be
very slow, and some servers may be reliable enough (to risk
delaying slightly flushing the data to disk on the server),
turning on this option may be useful to improve performance for
applications that fsync too much, at a small risk of server
crash.  If this mount option is not set, by default cifs will
send an SMB flush request (and wait for a response) on every
fsync call.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Fixes OOPs with message 'kernel BUG at fs/cifs/cifs_dfs_ref.c:274!'.
Checks if the prefixpath in an accesible while we are still in cifs_mount
and fails with reporting a error if we can't access the prefixpath

Should fix Samba bugs 6086 and 5861 and kernel bug 12192
Signed-off-by: NIgor Mammedov <niallain@gmail.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

The sockaddr declared on the stack in cifs_get_tcp_session is too small
for IPv6 addresses. Change it from "struct sockaddr" to "struct
sockaddr_storage" to prevent stack corruption when IPv6 is used.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

We have used approximately 15 second timeouts on nonblocking sends in the past, and
also 15 second SMB timeout (waiting for server responses, for most request types).
Now that we can do blocking tcp sends,
make blocking send timeout approximately the same (15 seconds).
Signed-off-by: NSteve French <sfrench@us.ibm.com>

cifs: turn smb_send into a wrapper around smb_sendv

Rename smb_send2 to smb_sendv to make it consistent with kernel naming
conventions for functions that take a vector.

There's no need to have 2 functions to handle sending SMB calls. Turn
smb_send into a wrapper around smb_sendv. This also allows us to
properly mark the socket as needing to be reconnected when there's a
partial send from smb_send.

Also, in practice we always use the address and noblocksnd flag
that's attached to the TCP_Server_Info. There's no need to pass
them in as separate args to smb_sendv.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

cifs: store password in tcon

Each tcon has its own password for share-level security. Store it in
the tcon and wipe it clean and free it when freeing the tcon. When
doing the tree connect with share-level security, use the tcon password
instead of the session password.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

cifs: have calc_lanman_hash take more granular args

We need to use this routine to encrypt passwords associated with the
tcon too. Don't assume that the password will be attached to the
smb_session.

Also, make some of the values in the lower encryption functions
const since they aren't changed.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

Some applications/subsystems require mandatory byte range locks
(as is used for Windows/DOS/OS2 etc). Sending advisory (posix style)
byte range lock requests (instead of mandatory byte range locks) can
lead to problems for these applications (which expect that other
clients be prevented from writing to portions of the file which
they have locked and are updating).  This mount option allows
mounting cifs with the new mount option "forcemand" (or
"forcemandatorylock") in order to have the cifs client use mandatory
byte range locks (ie SMB/CIFS/Windows/NTFS style locks) rather than
posix byte range lock requests, even if the server would support
posix byte range lock requests.  This has no effect if the server
does not support the CIFS Unix Extensions (since posix style locks
require support for the CIFS Unix Extensions), but for mounts
to Samba servers this can be helpful for Wine and applications
that require mandatory byte range locks.
Acked-by: NJeff Layton <jlayton@redhat.com>
CC: Alexander Bokovoy <ab@samba.org>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

In order to unify the smb_send routines, we need to reorganize the
routines that connect the sockets. Have ipv4_connect take a
TCP_Server_Info pointer and get the necessary fields from that.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

struct smb_vol is fairly large, it's probably best to kzalloc it...
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Clean up cifs_mount a bit by moving the code that creates new TCP
sessions into a separate function. Have that function search for an
existing socket and then create a new one if one isn't found.

Also reorganize the initializion of TCP_Server_Info a bit to prepare
for cleanup of the socket connection code.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

The current code for setting the session serverName is IPv4-specific.
Allow it to be an IPv6 address as well. Use NIP* macros to set the
format.

This also entails increasing the length of the serverName field, so
declare a new macro for RFC1001 name length and use it in the
appropriate places.

Finally, drop the unicode_server_Name field from TCP_Server_Info since
it's not used. We can add it back later if needed, but for now it just
wastes memory.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Mutexes are preferred for single-holder semaphores...
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

cifsd can outlive the last cifs mount. We need to hold a module
reference until it exits to prevent someone from unplugging
the module until we're ready.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

set tcon->ses earlier

If the inital tree connect fails, we'll end up calling cifs_put_smb_ses
with a NULL pointer. Fix it by setting the tcon->ses earlier.
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>