On V4ROOT exports, only accept filehandles that are the *root* of some
export. This allows mountd to allow or deny access to individual
directories and symlinks on the pseudofilesystem.
Note that the checks in readdir and lookup are not enough, since a
malicious host with access to the network could guess filehandles that
they weren't able to obtain through lookup or readdir.
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
We want to allow exports of symlinks, to allow mountd to communicate to
the kernel which symlinks lead to exports, and hence which symlinks need
to be visible on the pseudofilesystem.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
As with lookup, we treat every boject as a mountpoint and pretend it
doesn't exist if it isn't exported.
The preexisting code here is confusing, but I haven't yet figured out
how to make it clearer.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
If /A/mount/point/ has filesystem "B" mounted on top of it, and if "A"
is exported, but not "B", then the nfs server has always returned to the
client a filehandle for the mountpoint, instead of for the root of "B",
allowing the client to see the subtree of "A" that would otherwise be
hidden by B.
Disable this behavior in the case of V4ROOT exports; we implement the
path restrictions of V4ROOT exports by treating *every* directory as if
it were a mountpoint, and allowing traversal *only* if the new directory
is exported.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
NFSv4 differs from v2 and v3 in that it presents a single unified
filesystem tree, whereas v2 and v3 exported multiple filesystem (whose
roots could be found using a separate mount protocol).
Our original NFSv4 server implementation asked the administrator to
designate a single filesystem as the NFSv4 root, then to mount
filesystems they wished to export underneath. (Often using bind mounts
of already-existing filesystems.)
This was conceptually simple, and allowed easy implementation, but
created a serious obstacle to upgrading between v2/v3: since the paths
to v4 filesystems were different, administrators would have to adjust
all the paths in client-side mount commands when switching to v4.
Various workarounds are possible. For example, the administrator could
export "/" and designate it as the v4 root. However, the security risks
of that approach are obvious, and in any case we shouldn't be requiring
the administrator to take extra steps to fix this problem; instead, the
server should present consistent paths across different versions by
default.
These patches take a modified version of that approach: we provide a new
export option which exports only a subset of a filesystem. With this
flag, it becomes safe for mountd to export "/" by default, with no need
for additional configuration.
We begin just by defining the new flag.
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This was an oversight; it should be among the export flags that can be
allowed to vary by pseudoflavor. This allows an administrator to (for
example) allow auth_sys mounts only from low ports, but allow auth_krb5
mounts to use any port.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Soon we will add the new V4ROOT flag, and allow the INSECURE flag to
vary by pseudoflavor. It would be useful for nfs-utils (for example,
for improved exportfs error reporting) to be able to know when this
happens. Use this new interface for that purpose.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Lots of include/linux/nfsd/* headers are only used by
nfsd module. Move them to the source directory
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Now that the headers are fixed and carry their own wait, all fs/nfsd/
source files can include a minimal set of headers. and still compile just
fine.
This patch should improve the compilation speed of the nfsd module.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
NFSv4 opens may function as locks denying other NFSv4 users the rights
to open a file.
We're requiring a user to have write permissions before they can deny
write. We're *not* requiring a user to have write permissions to deny
read, which is if anything a more drastic denial.
What was intended was to require write permissions for DENY_READ.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
All nfsd security depends on the security checks in fh_verify, and
especially on nfsd_setuser().
It therefore bothers me that the nfsd_setuser call may be made from
three different places, depending on whether the filehandle has already
been mapped to a dentry, and on whether subtreechecking is in force.
Instead, make an unconditional call in fh_verify(), so it's trivial to
verify that the call always occurs.
That leaves us with a redundant nfsd_setuser() call in the subtreecheck
case--it needs the correct user set earlier in order to check execute
permissions on the path to this filehandle--but I'm willing to accept
that minor inefficiency in the subtreecheck case in return for more
straightforward permission checking.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Commit 8177e6d6df ("nfsd: clean up
readdirplus encoding") introduced single character typo in nfs3 readdir+
implementation. Unfortunately that typo has quite bad side effects:
random memory corruption, followed (on my box) with immediate
spontaneous box reboot.
Using 'p1' instead of 'p' fixes my Linux box rebooting whenever VMware
ESXi box tries to list contents of my home directory.
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
None of this stuff is used outside nfsd, so move it out of the common
linux include directory.
Actually, probably none of the stuff in include/linux/nfsd/nfsd.h really
belongs there, so later we may remove that file entirely.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Modify the NFS server to register the NFS_ACL services with the rpcbind
daemon. This allows the client to ping for the existence of the NFS_ACL
support via commands such as "rpcinfo -t <server> nfs_acl".
This patch also modifies the NFS_ACL support so that responses to
version 2 NULLPROC requests can be made.
The changelog for the patch which turned off this functionality
mentioned something about not registering the NFS_ACL as being part of
some tradition. I can't find this tradition and the only other
implementation which supports NFS_ACL does register them with the
rpcbind daemon.
Signed-off-by: Peter Staubach <staubach@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
We have been doing some extensive testing of Linux support for ACLs on
NFDS v4. We have noticed that the server rejects ACLs where the groups
are out of order, for example, the following ACL is rejected:
A::OWNER@:rwaxtTcCy
A::user101@domain:rwaxtcy
A::GROUP@:rwaxtcy
A:g:group102@domain:rwaxtcy
A:g:group101@domain:rwaxtcy
A::EVERYONE@:rwaxtcy
Examining the server code, I found that after converting an NFS v4 ACL
to POSIX, sort_pacl is called to sort the user ACEs and group ACEs.
Unfortunately, a minor bug causes the group sort to be skipped.
Signed-off-by: Frank Filz <ffilzlnx@us.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
We do the same calculation in a couple places; use a helper function,
and add a little documentation, in the hopes of preventing bugs like
that fixed in the last patch.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Unbalanced calculations on creation and destruction of sessions could
cause our estimate of cache memory used to become negative, sometimes
resulting in spurious SERVERFAULT returns to client CREATE_SESSION
requests.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
ca_maxresponsesize and ca_maxrequest size include the RPC header.
sv_max_mesg is sv_max_payolad plus a page for overhead and is used in
svc_init_buffer to allocate server buffer space for both the request and reply.
Note that this means we can service an RPC compound that requires
ca_maxrequestsize (MAXWRITE) or ca_max_responsesize (MAXREAD) but that we do
not support an RPC compound that requires both ca_maxrequestsize and
ca_maxresponsesize.
Signed-off-by: Andy Adamson <andros@netapp.com>
[bfields@citi.umich.edu: more documentation updates]
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
We really shouldn't hit this case at all, and forthcoming kernel and
nfs-utils changes should eliminate this case; if it does happen,
consider it a bug rather than reporting an error that doesn't really
make sense for the operation (since there's no reason for a server to be
accepting v4 traffic yet have no root filehandle).
Also move some exp_pseudoroot code into a helper function while we're
here.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
3c394ddaa7 "nfsd4: nfsv4 clients should
cross mountpoints" forgot to handle lookups of parents directories.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* remove asm/atomic.h inclusion from linux/utsname.h --
not needed after kref conversion
* remove linux/utsname.h inclusion from files which do not need it
NOTE: it looks like fs/binfmt_elf.c do not need utsname.h, however
due to some personality stuff it _is_ needed -- cowardly leave ELF-related
headers and files alone.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make all seq_operations structs const, to help mitigate against
revectoring user-triggerable function pointers.
This is derived from the grsecurity patch, although generated from scratch
because it's simpler than extracting the changes from there.
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-2.6.32' of git://linux-nfs.org/~bfields/linux: (68 commits)
nfsd4: nfsv4 clients should cross mountpoints
nfsd: revise 4.1 status documentation
sunrpc/cache: avoid variable over-loading in cache_defer_req
sunrpc/cache: use list_del_init for the list_head entries in cache_deferred_req
nfsd: return success for non-NFS4 nfs4_state_start
nfsd41: Refactor create_client()
nfsd41: modify nfsd4.1 backchannel to use new xprt class
nfsd41: Backchannel: Implement cb_recall over NFSv4.1
nfsd41: Backchannel: cb_sequence callback
nfsd41: Backchannel: Setup sequence information
nfsd41: Backchannel: Server backchannel RPC wait queue
nfsd41: Backchannel: Add sequence arguments to callback RPC arguments
nfsd41: Backchannel: callback infrastructure
nfsd4: use common rpc_cred for all callbacks
nfsd4: allow nfs4 state startup to fail
SUNRPC: Defer the auth_gss upcall when the RPC call is asynchronous
nfsd4: fix null dereference creating nfsv4 callback client
nfsd4: fix whitespace in NFSPROC4_CLNT_CB_NULL definition
nfsd41: sunrpc: add new xprt class for nfsv4.1 backchannel
sunrpc/cache: simplify cache_fresh_locked and cache_fresh_unlocked.
...
Allow NFS v4 clients to seamlessly cross mount point without
have to set either the 'crossmnt' or the 'nohide' export
options.
Signed-Off-By: Steve Dickson <steved@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Move common initialization of 'struct nfs4_client' inside create_client().
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[nfsd41: Remember the auth flavor to use for callbacks]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This patch enables the use of the nfsv4.1 backchannel.
Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
[initialize rpc_create_args.bc_xprt too]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Implement the cb_sequence callback conforming to draft-ietf-nfsv4-minorversion1
Note: highest slot id and target highest slot id do not have to be 0
as was previously implemented. They can be greater than what the
nfs server sent if the client supports a larger slot table on the
backchannel. At this point we just ignore that.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[Rework the back channel xdr using the shared v4.0 and v4.1 framework.]
Signed-off-by: Andy Adamson <andros@netapp.com>
[fixed indentation]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: use nfsd4_cb_sequence for callback minorversion]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: fix verification of CB_SEQUENCE highest slot id[
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: Backchannel: Remove old backchannel serialization]
[nfsd41: Backchannel: First callback sequence ID should be 1]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: decode_cb_sequence does not need to actually decode ignored fields]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Follows the model used by the NFS client. Setup the RPC prepare and done
function pointers so that we can populate the sequence information if
minorversion == 1. rpc_run_task() is then invoked directly just like
existing NFS client operations do.
nfsd4_cb_prepare() determines if the sequence information needs to be setup.
If the slot is in use, it adds itself to the wait queue.
nfsd4_cb_done() wakes anyone sleeping on the callback channel wait queue
after our RPC reply has been received. It also sets the task message
result pointer to NULL to clearly indicate we're done using it.
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[define and initialize cl_cb_seq_nr here]
[pulled out unused defintion of nfsd4_cb_done]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
RPC callback requests will wait on this wait queue if the backchannel
is out of slots.
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Follow the model we use in the client. Make the sequence arguments
part of the regular RPC arguments. None of the callbacks that are
soon to be implemented expect results that need to be passed back
to the caller, so we don't define a separate RPC results structure.
For session validation, the cb_sequence decoding will use a pointer
to the sequence arguments that are part of the RPC argument.
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[define struct nfsd4_cb_sequence here]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Keep the xprt used for create_session in cl_cb_xprt.
Mark cl_callback.cb_minorversion = 1 and remember
the client provided cl_callback.cb_prog rpc program number.
Use it to probe the callback path.
Use the client's network address to initialize as the
callback's address as expected by the xprt creation
routines.
Define xdr sizes and code nfs4_cb_compound header to be able
to send a null callback rpc.
Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[get callback minorversion from fore channel's]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: change bc_sock to bc_xprt]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[pulled definition for cl_cb_xprt]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: set up backchannel's cb_addr]
[moved rpc_create_args init to "nfsd: modify nfsd4.1 backchannel to use new xprt class"]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Callbacks are always made using the machine's identity, so we can use a
single auth_generic credential shared among callbacks to all clients and
let the rpc code take care of the rest.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
On setting up the callback to the client, we attempt to use the same
authentication flavor the client did. We find an rpc cred to use by
calling rpcauth_lookup_credcache(), which assumes that the given
authentication flavor has a credentials cache. However, this is not
required to be true--in particular, auth_null does not use one.
Instead, we should call the auth's lookup_cred() method.
Without this, a client attempting to mount using nfsv4 and auth_null
triggers a null dereference.
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Make the return from compose_entry_fh() zero or an error, even though
the returned error isn't used, just to make the meaning of the return
immediately obvious.
Move some repeated code out of main function into helper.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
A number of callers (nfsd4_encode_fattr(), at least) don't bother to
release the filehandle returned to fh_compose() if fh_compose() returns
an error. So, modify fh_compose() to release the filehandle before
returning an error.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
nfsd4_path() allocates a temporary filehandle and then fails to free it
before the function exits, leaking reference counts to the dentry and
export that it refers to.
Also, nfsd4_lookupp() puts the result of exp_pseudoroot() in a temporary
filehandle which it releases on success of exp_pseudoroot() but not on
failure; fix exp_pseudoroot to ensure that on failure it releases the
filehandle before returning.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
J. Bruce Fields
Steve Dickson
Boaz Harrosh
Petr Vandrovec
Benny Halevy
Peter Staubach
Frank Filz
Alexey Dobriyan
Andy Adamson
James Morris
Linus Torvalds
Ricardo Labiaga
Alexandros Batsakis
Trond Myklebust