Now build security descriptor to change either owner or group at the
server. Initially security descriptor was built to change only
(D)ACL, that functionality has been extended.
When either an Owner or a Group of a file object at the server is changed,
rest of security descriptor remains same (DACL etc.).
To set security descriptor, it is necessary to open that file
with permission bits of either WRITE_DAC if DACL is being modified or
WRITE_OWNER (Take Ownership) if Owner or Group is being changed.
It is the server that decides whether a set security descriptor with
either owner or group change succeeds or not.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Add data structures and functions necessary to map a uid and gid to SID.
These functions are very similar to the ones used to map a SID to uid and gid.
This time, instead of storing sid to id mapping sorted on a sid value,
id to sid is stored, sorted on an id.
A cifs upcall sends an id (uid or gid) and expects a SID structure
in return, if mapping was done successfully.
A failed id to sid mapping to EINVAL.
This patchset aims to enable chown and chgrp commands when
cifsacl mount option is specified, especially to Windows SMB servers.
Currently we can't do that. So now along with chmod command,
chown and chgrp work.
Winbind is used to map id to a SID. chown and chgrp use an upcall
to provide an id to winbind and upcall returns with corrosponding
SID if any exists. That SID is used to build security descriptor.
The DACL part of a security descriptor is not changed by either
chown or chgrp functionality.
cifs client maintains a separate caches for uid to SID and
gid to SID mapping. This is similar to the one used earlier
to map SID to id (as part of ID mapping code).
I tested it by mounting shares from a Windows (2003) server by
authenticating as two users, one at a time, as Administrator and
as a ordinary user.
And then attempting to change owner of a file on the share.
Depending on the permissions/privileges at the server for that file,
chown request fails to either open a file (to change the ownership)
or to set security descriptor.
So it all depends on privileges on the file at the server and what
user you are authenticated as at the server, cifs client is just a
conduit.
I compared the security descriptor during chown command to that
what smbcacls sends when it is used with -M OWNNER: option
and they are similar.
This patchset aim to enable chown and chgrp commands when
cifsacl mount option is specified, especially to Windows SMB servers.
Currently we can't do that. So now along with chmod command,
chown and chgrp work.
I tested it by mounting shares from a Windows (2003) server by
authenticating as two users, one at a time, as Administrator and
as a ordinary user.
And then attempting to change owner of a file on the share.
Depending on the permissions/privileges at the server for that file,
chown request fails to either open a file (to change the ownership)
or to set security descriptor.
So it all depends on privileges on the file at the server and what
user you are authenticated as at the server, cifs client is just a
conduit.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Add mount options backupuid and backugid.
It allows an authenticated user to access files with the intent to back them
up including their ACLs, who may not have access permission but has
"Backup files and directories user right" on them (by virtue of being part
of the built-in group Backup Operators.
When mount options backupuid is specified, cifs client restricts the
use of backup intents to the user whose effective user id is specified
along with the mount option.
When mount options backupgid is specified, cifs client restricts the
use of backup intents to the users whose effective user id belongs to the
group id specified along with the mount option.
If an authenticated user is not part of the built-in group Backup Operators
at the server, access to such files is denied, even if allowed by the client.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Set security descriptor using path name instead of a file handle.
We can't be sure that the file handle has adequate permission to
set a security descriptor (to modify DACL).
Function set_cifs_acl_by_fid() has been removed since we can't be
sure how a file was opened for writing, a valid request can fail
if the file was not opened with two above mentioned permissions.
We could have opted to add on WRITE_DAC and WRITE_OWNER permissions
to file opens and then use that file handle but adding addtional
permissions such as WRITE_DAC and WRITE_OWNER could cause an
any open to fail.
And it was incorrect to look for read file handle to set a
security descriptor anyway.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Commit 1495f230fa ("vmscan: change shrinker API by passing
shrink_control struct") changed the API of ->shrink(), but missed ubifs
and cifs instances.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As Jeff just pointed out, __constant_cpu_to_le32 was required instead of
cpu_to_le32 in previous patch to cifsacl.c 383c55350f
(Fix endian error comparing authusers when cifsacl enabled)
CC: Stable <stable@kernel.org>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Fix sparse warning:
CHECK fs/cifs/cifsacl.c
fs/cifs/cifsacl.c:41:36: warning: incorrect type in initializer
(different base types)
fs/cifs/cifsacl.c:41:36: expected restricted __le32
fs/cifs/cifsacl.c:41:36: got int
fs/cifs/cifsacl.c:461:52: warning: restricted __le32 degrades to integer
fs/cifs/cifsacl.c:461:73: warning: restricted __le32 degrades to integer
The second one looks harmless but the first one (sid_authusers)
was added in commit 2fbc2f1729
and only affects 2.6.38/2.6.39
CC: Stable <stable@kernel.org>
Reviewed-and-Tested-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Change idmap key name from cifs.cifs_idmap to cifs.idmap.
Removed unused structure wksidarr and function match_sid().
Handle errors correctly in function init_cifs().
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
fs/cifs/cifsacl.c: In function ‘id_rb_search’:
fs/cifs/cifsacl.c:215:19: warning: variable ‘linkto’ set but not used
[-Wunused-but-set-variable]
fs/cifs/cifsacl.c:214:18: warning: variable ‘parent’ set but not used
[-Wunused-but-set-variable]
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
rb tree search and insertion routines.
A SID which needs to be mapped, is looked up in one of the rb trees
depending on whether SID is either owner or group SID.
If found in the tree, a (mapped) id from that node is assigned to
uid or gid as appropriate. If unmapped, an upcall is attempted to
map the SID to an id. If upcall is successful, node is marked as
mapped. If upcall fails, node stays marked as unmapped and a mapping
is attempted again only after an arbitrary time period has passed.
To map a SID, which can be either a Owner SID or a Group SID, key
description starts with the string "os" or "gs" followed by SID converted
to a string. Without "os" or "gs", cifs.upcall does not know whether
SID needs to be mapped to either an uid or a gid.
Nodes in rb tree have fields to prevent multiple upcalls for
a SID. Searching, adding, and removing nodes is done within global locks.
Whenever a node is either found or inserted in a tree, a reference
is taken on that node.
Shrinker routine prunes a node if it has expired but does not prune
an expired node if its refcount is not zero (i.e. sid/id of that node
is_being/will_be accessed).
Thus a node, if its SID needs to be mapped by making an upcall,
can safely stay and its fields accessed without shrinker pruning it.
A reference (refcount) is put on the node without holding the spinlock
but a reference is get on the node by holding the spinlock.
Every time an existing mapped node is accessed or mapping is attempted,
its timestamp is updated to prevent it from getting erased or a
to prevent multiple unnecessary repeat mapping retries respectively.
For now, cifs.upcall is only used to map a SID to an id (uid or gid) but
it would be used to obtain an SID for an id.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Define (global) data structures to store ids, uids and gids, to which a
SID maps. There are two separate trees, one for SID/uid and another one
for SID/gid.
A new type of key, cifs_idmap_key_type, is used.
Keys are instantiated and searched using credential of the root by
overriding and restoring the credentials of the caller requesting the key.
Id mapping functions are invoked under config option of cifs acl.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Allow setting cifs_acl on the server.
Pass on to the server the ACL blob generated by an application.
cifs is just a pass-through, it does not monitor or inspect the contents
of the blob, server decides whether to enforce/apply the ACL blob composed
by an application.
If setting of ACL is succeessful, mark the inode for revalidation.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Exit from parse_dacl if no memory returned from the call to kmalloc.
Signed-off-by: Stanislav Fomichev <kernel@fomichev.me>
Signed-off-by: Steve French <sfrench@us.ibm.com>
If a DACL has entries for ACEs for SID Everyone and Authenticated Users,
factor in mask in respective entries during calculation of permissions
for all three, user, group, and other.
http://technet.microsoft.com/en-us/library/bb463216.aspx
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Some of the code under CONFIG_CIFS_ACL is dependent upon code under
CONFIG_CIFS_EXPERIMENTAL, but the Kconfig options don't reflect that
dependency. Move more of the ACL code out from under
CONFIG_CIFS_EXPERIMENTAL and under CONFIG_CIFS_ACL.
Also move find_readable_file out from other any sort of Kconfig
option and make it a function normally compiled in.
Reported-and-Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Add extended attribute name system.cifs_acl
Get/generate cifs/ntfs acl blob and hand over to the invoker however
it wants to parse/process it under experimental configurable option CIFS_ACL.
Do not get CIFS/NTFS ACL for xattr for attribute system.posix_acl_access
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Change the name of function mode_to_acl to mode_to_cifs_acl.
Handle return code in functions mode_to_cifs_acl and
cifs_acl_to_fattr.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Modify get/set_cifs_acl* calls to reutrn error code and percolate the
error code up to the caller.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When we implement multiuser mounts, we'll need to filter filehandles
by fsuid. Add a flag for multiuser mounts and code to filter by
fsuid when it's set.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Eventually, we'll need to track the use of tcons on a per-sb basis, so that
we know when it's ok to tear them down. Begin this conversion by adding a
new "tcon_link" struct and accessors that get it. For now, the core data
structures are untouched -- cifs_sb still just points to a single tcon and
the pointers are just cast to deal with the accessor functions. A later
patch will flesh this out.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When we convert cifs to do multiple sessions per mount, we'll need more
than one tcon per superblock. At that point "cifs_sb->tcon" will make
no sense. Add a new accessor function that gets a tcon given a cifs_sb.
For now, it just returns cifs_sb->tcon. Later it'll do more.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Neaten cERROR and cFYI macros, reduce text space
~2.5K
Convert '__FILE__ ": " fmt' to '"%s: " fmt', __FILE__' to save text space
Surround macros with do {} while
Add parentheses to macros
Make statement expression macro from macro with assign
Remove now unnecessary parentheses from cFYI and cERROR uses
defconfig with CIFS support old
$ size fs/cifs/built-in.o
text data bss dec hex filename
156012 1760 148 157920 268e0 fs/cifs/built-in.o
defconfig with CIFS support old
$ size fs/cifs/built-in.o
text data bss dec hex filename
153508 1760 148 155416 25f18 fs/cifs/built-in.o
allyesconfig old:
$ size fs/cifs/built-in.o
text data bss dec hex filename
309138 3864 74824 387826 5eaf2 fs/cifs/built-in.o
allyesconfig new
$ size fs/cifs/built-in.o
text data bss dec hex filename
305655 3864 74824 384343 5dd57 fs/cifs/built-in.o
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Currently, cifs_close() tries to wait until all I/O is complete and then
frees the file private data. If I/O does not completely in a reasonable
amount of time it frees the structure anyway, leaving a potential use-
after-free situation.
This patch changes the wrtPending counter to a complete reference count and
lets the last user free the structure.
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: convert cifs_get_inode_info and non-posix readdir to use cifs_iget
Rather than allocating an inode and filling it out, have
cifs_get_inode_info fill out a cifs_fattr and call cifs_iget. This means
a pretty hefty reorganization of cifs_get_inode_info.
For the readdir codepath, add a couple of new functions for filling out
cifs_fattr's from different FindFile response infolevels.
Finally, remove cifs_new_inode since there are no more callers.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Thus spake Christoph:
"But this whole set_cifs_acl function is a real mess anyway and needs
some splitting up."
With this change too, it's possible to call acl_to_uid_mode() with a
NULL inode pointer. That (or something close to it) will eventually be
necessary when cifs_get_inode_info is reorganized.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
In mode_to_acl when converting a Unix mode to a Windows ACL
the subauth fields of the SID in the ACL were translated
incorrectly on bigendian architectures
Signed-off-by: Steve French <sfrench@us.ibm.com>
The current definition of wksidarr works fine on little endian arches
(since cpu_to_le32 is a no-op there), but on big-endian arches, it fails
to compile with this error:
error: braced-group within expression allowed only inside a function
The problem is that this static declaration has cpu_to_le32 embedded
within it, and that expands into a function macro. We need to use
__constant_cpu_to_le32() instead.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shirish Pargaonkar noted:
With cifsacl mount option, when a file is created on the Windows server,
exclusive oplock is broken right away because the get cifs acl code
again opens the file to obtain security descriptor.
The client does not have the newly created file handle or inode in any
of its lists yet so it does not respond to oplock break and server waits for
its duration and then responds to the second open. This slows down file
creation signficantly. The fix is to pass the file descriptor to the get
cifsacl code wherever available so that get cifs acl code does not send
second open (NT Create ANDX) and oplock is not broken.
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This patch fixes an error in the experimental cifs acl code. During chmod,
set security descriptor data (num aces) is not sent with little-endian encoding.
Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Christoph had noticed too many ifdefs in the CIFS code making it
hard to read. This patch removes about a quarter of them from
the C files in cifs by improving a few key ifdefs in the .h files.
Signed-off-by: Steve French <sfrench@us.ibm.com>
Requires cifsacl mount flag to be on and CIFS_EXPERIMENTAL enabled
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
access_flags_to_mode() gets on-the-wire data (little-endian) and treats
it as host-endian.
Introduced in commit e01b640013 ("[CIFS]
enable get mode from ACL when cifsacl mount option specified")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When mounted with the cifsacl mount option, we were
treating any deny ACEs found like allow ACEs and it turns out for
SFU and SUA Windows set these type of access control entries often.
The order of ACEs is important too. The canonical order that most
ACL tools and Windows explorer consruct ACLs with is to begin with
DENY entries then follow with ALLOW, otherwise an allow entry
could be encountered first, making the subsequent deny entry like "dead
code which would be superflous since Windows stops when a match is
made for the operation you are trying to perform for your user
We start with no permissions in the mode and build up as we find
permissions (ie allow ACEs). This fixes deny ACEs so they affect
the mask used to set the subsequent allow ACEs.
Acked-by: Shirish Pargaonkar <shirishp@us.ibm.com>
CC: Alexander Bokovoy <ab@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We were requesting GENERIC_READ but that fails when we do not have
read permission on the file (even if we could read the ACL).
Also move the dump access control entry code into debug ifdef.
Signed-off-by: Steve French <sfrench@us.ibm.com>
Part 9 of ACL patch series. getting mode from ACL now works in
some cases (and requires CIFS_EXPERIMENTAL config option).
Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Now GetACL in getinodeinfo path when cifsacl mount option used, and
ACL is parsed for SIDs. Missing only one piece now to be able
to retrieve the mode
Signed-off-by: Steve French <sfrench@us.ibm.com>
Shirish Pargaonkar
Al Viro
Steve French
Jeff Layton
Stanislav Fomichev
Joe Perches
Tejun Heo
Dave Kleikamp
Christoph Hellwig
Shirish Pargaonkar
Al Viro
Shirish Pargaonkar