If the admin has specified the "noresvport" option for an NFS mount
point, the kernel's NFS client uses an unprivileged source port for
the main NFS transport. The kernel's mountd client should use an
unprivileged port in this case as well.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The standard default security setting for NFS is AUTH_SYS. An NFS
client connects to NFS servers via a privileged source port and a
fixed standard destination port (2049). The client sends raw uid and
gid numbers to identify users making NFS requests, and the server
assumes an appropriate authority on the client has vetted these
values because the source port is privileged.
On Linux, by default in-kernel RPC services use a privileged port in
the range between 650 and 1023 to avoid using source ports of well-
known IP services. Using such a small range limits the number of NFS
mount points and the number of unique NFS servers to which a client
can connect concurrently.
An NFS client can use unprivileged source ports to expand the range of
source port numbers, allowing more concurrent server connections and
more NFS mount points. Servers must explicitly allow NFS connections
from unprivileged ports for this to work.
In the past, bumping the value of the sunrpc.max_resvport sysctl on
the client would permit the NFS client to use unprivileged ports.
Bumping this setting also changes the maximum port number used by
other in-kernel RPC services, some of which still required a port
number less than 1023.
This is exacerbated by the way source port numbers are chosen by the
Linux RPC client, which starts at the top of the range and works
downwards. It means that bumping the maximum means all RPC services
requesting a source port will likely get an unprivileged port instead
of a privileged one.
Changing this setting effects all NFS mount points on a client. A
sysadmin could not selectively choose which mount points would use
non-privileged ports and which could not.
Lastly, this mechanism of expanding the limit on the number of NFS
mount points was entirely undocumented.
To address the need for the NFS client to use a large range of source
ports without interfering with the activity of other in-kernel RPC
services, we introduce a new NFS mount option. This option explicitly
tells only the NFS client to use a non-privileged source port when
communicating with the NFS server for one specific mount point.
This new mount option is called "resvport," like the similar NFS mount
option on FreeBSD and Mac OS X. A sister patch for nfs-utils will be
submitted that documents this new option in nfs(5).
The default setting for this new mount option requires the NFS client
to use a privileged port, as before. Explicitly specifying the
"noresvport" mount option allows the NFS client to use an unprivileged
source port for this mount point when connecting to the NFS server
port.
This mount option is supported only for text-based NFS mounts.
[ Sidebar: it is widely known that security mechanisms based on the
use of privileged source ports are ineffective. However, the NFS
client can combine the use of unprivileged ports with the use of
secure authentication mechanisms, such as Kerberos. This allows a
large number of connections and mount points while ensuring a useful
level of security.
Eventually we may change the default setting for this option
depending on the security flavor used for the mount. For example,
if the mount is using only AUTH_SYS, then the default setting will
be "resvport;" if the mount is using a strong security flavor such
as krb5, the default setting will be "noresvport." ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
[Trond.Myklebust@netapp.com: Fixed a bug whereby nfs4_init_client()
was being called with incorrect arguments.]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: convert nfs_mount() to take a single data structure argument to make
it simpler to add more arguments.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.
This was posted for review some time ago and I believe its been in -mm
since then.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bruce observed that nfs_parse_ip_address() will successfully parse an
IPv6 address that looks like this:
"::1%"
A scope delimiter is present, but there is no scope ID following it.
This is harmless, as it would simply set the scope ID to zero. However,
in some cases we would like to flag this as an improperly formed
address.
We are now also careful to reject addresses where garbage follows the
address (up to the length of the string), instead of ignoring the
non-address characters; and where the scope ID is nonsense (not a valid
device name, but also not numeric). Before, both of these cases would
result in a harmless zero scope ID.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The code incorrectly assumes here that the server name (or ip address)
is null-terminated. This can cause referrals to fail in some cases.
Also support ipv6 addresses.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We plan to use this function elsewhere.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The point of introducing text-based mounts was to allow us to add
functionality without having to worry about legacy binary mount formats.
The mask should be there in order to ensure that binary formats don't start
enabling features that they cannot support. There is no justification for
applying it to the text mount path.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Instead of causing umount requests to block on server->active_wq while the
asynchronous sillyrename deletes are executing, we can use the sb->s_active
counter to obtain a reference to the super_block, and then release that
reference in nfs_async_unlink_release().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Automounter maps can contain mount options valid for other NFS
implementations but not for Linux. The Linux automounter uses the
mount command's "-s" command line option ("s" for "sloppy") so that
mount requests containing such options are not rejected.
Commit f45663ce5f attempted to address a
known regression with text-based NFS mount option parsing. Unrecognized
mount options would cause mount requests to fail, even if the "-s"
option was used on the mount command line.
Unfortunately, this commit was not complete as submitted. It adds a
new mount option, "sloppy". But it is missing a hunk, so it now allows
NFS mounts with unrecognized mount options, even if the "sloppy" option
is not present. This could be a problem if a required critical mount
option such as "sync" is misspelled, for example, and is considered a
regression from 2.6.26.
This patch restores the missing hunk. Now, the default behavior of
text-based NFS mount options is as before: any unrecognized mount option
will cause the mount to fail.
Please include this in 2.6.27-rc.
Thanks to Neil Brown for reporting this.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel's NFS client mount option parser currently doesn't allow
unrecognized or incorrect mount options. This prevents misspellings or
incorrectly specified mount options from possibly causing silent data
corruption.
However, NFS mount options are not standardized, so different operating
systems can use differently spelled mount options to support similar
features, or can support mount options which no other operating system
supports.
"Sloppy" mount option parsing, which allows the parser to ignore any
option it doesn't recognize, is needed to support automounters that often
use maps that are shared between heterogenous operating systems.
The legacy mount command ignores the validity of the values of mount
options entirely, except for the "sec=" and "proto=" options. If an
incorrect value is specified, the out-of-range value is passed to the
kernel; if a value is specified that contains non-numeric characters,
it appears as though the legacy mount command sets that option to zero
(probably incorrect behavior in general).
In any case, this sets a precedent which we will partially follow for
the kernel mount option parser:
+ if "sloppy" is not set, the parser will be strict about both
unrecognized options (same as legacy) and invalid option
values (stricter than legacy)
+ if "sloppy" is set, the parser will ignore unrecognized
options and invalid option values (same as legacy)
An "invalid" option value in this case means that either the type
(integer, short, or string) or sign (for integer values) of the specified
value is incorrect.
This patch does two things: it changes the NFS client's mount option
parsing loop so that it parses the whole string instead of failing at
the first unrecognized option or invalid option value. An unrecognized
option or an invalid option value cause the option to be skipped.
Then, the patch adds a "sloppy" mount option that allows the parsing
to succeed anyway if there were any problems during parsing. When
parsing a set of options is complete, if there are errors and "sloppy"
was specified, return success anyway. Otherwise, only return success
if there are no errors.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Set the default security flavor when we set the other mount option
default values for NFSv4. This cleans up the NFSv4 mount option parsing
path to look like the NFSv2/v3 one.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Set the default security flavor when we set the other mount option default
values. After this change, only the legacy user-space mount path needs to
set the NFS_MOUNT_SECFLAVOUR flag.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: Refactor the NFS mount option parsing function to extract the
security flavor parsing logic into a separate function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The remount path does not need to set the port in the server address.
Since it's not really a part of option parsing, move the nfs_set_port()
call to nfs_parse_mount_options()'s callers.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Move the UDP/TCP default timeo/retrans settings for text mounts to
nfs_init_timeout_values(), which was were they were always being
initialised (and sanity checked) for binary mounts.
Document the default timeout values using appropriate #defines.
Ensure that we initialise and sanity check the transport protocols that
may have been specified by the user.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Add support in the kernel NFS client's address parser for interface
identifiers.
IPv6 link-local addresses require an additional "interface identifier",
which is a network device name or an integer that indexes the array of
local network interfaces. They are suffixed to the address with a '%'.
For example:
fe80::215:c5ff:fe3b:e1b2%2
indicates an interface index of 2. Or
fe80::215:c5ff:fe3b:e1b2%eth0
indicates that requests should be routed through the eth0 device.
Without the interface ID, link-local addresses are not usable for NFS.
Both the kernel NFS client mount option parser and the mount.nfs command
can take either form. The mount.nfs command always passes the address
through getnameinfo(3), which usually re-writes interface indices as
device names.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
To make nfs_parse_server_address() more generally useful, allow it to
accept input strings that are not terminated with '\0'.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Traditionally the mount command has looked for a ":" to separate the
server's hostname from the export path in the mounted on device name,
like this:
mount server:/export /mounted/on/dir
The server's hostname is "server" and the export path is "/export".
You can also substitute a specific IPv4 network address for the server
hostname, like this:
mount 192.168.0.55:/export /mounted/on/dir
Raw IPv6 addresses present a problem, however, because they look
something like this:
fe80::200:5aff:fe00:30b
Note the use of colons.
To get around the presence of colons, copy the Solaris convention used for
mounting IPv6 servers by address: wrap a raw IPv6 address with square
brackets.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
To support passing a raw IPv6 address as a server hostname, we need to
expand the logic that handles splitting the passed-in device name into
a server hostname and export path
Start by pulling device name parsing out of the mount option validation
functions and into separate helper functions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix the 'nfs4_fs_type' undeclared error in nfs_remount when compiling sans
NFSv4...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Jeff Layton <jlayton@redhat.com>
Clean up: the "intr" and "nointr" mount options were recently retired.
Document this in the NFS mount option parser.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The kernel NFS mount option parser should ignore the retry= mount option
since it is meaningful only in user space. Today it expects a number
rather than arbitrary text, so it ignores the option if the value is
numeric, but chokes if there are other characters in the value.
Change it to allow any text (except ",") as its value.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When remounting an NFS or NFS4 filesystem, the new NFS options are not
respected, yet the remount will still return success. This patch adds
a remount_fs sb op for NFS that checks any new nfs mount options against
the existing ones and fails the mount if any have changed.
This is only implemented for string-based mount options since doing
this with binary options isn't really feasible.
This is essentially the same as the original patch I sent out, but
adds a check to see if the addr= option has changed.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix a sign issue in xdr_decode_fhstatus3()
Fix incorrect comparison in nfs_validate_mount_data()
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFSv3 get_sb operations call into the LSM layer to set security options passed
from userspace. NFSv4 hooks were not originally added since it was reasonably
late in the merge window and NFSv3 was the only thing that had regressed (v4
has never supported any LSM options)
This patch makes NFSv4 call into the LSM to set security options rather than
just blindly dropping them with no notice to the user as happens today. This
patch was tested in a simple NFSv4 environment with the context= option and
appeared to work as expected.
Signed-off-by: Eric Paris <eparis@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Register NFS' backing_dev_info under sysfs with the name "nfs-MAJOR:MINOR"
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is possible NULL pointer dereference if kstr[n]dup failed.
So fix them for safety.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
... and take it out of ->umount_begin() instances. Call with all locks
already taken (by do_umount()) and leave calling release_mounts() to
caller (it will do release_mounts() anyway, so we can just put into
the same list).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Display all mount options in /proc/mount which may be needed to reconstruct
a previous mount.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
During a remount based on the mount options displayed in /proc/mounts, we
want to preserve the original behavior of the mount request. Let's save
the original setting of the "port=" mount option in the mount's nfs_server
structure.
This allows us to simplify the default behavior of port setting for NFSv4
mounts: by default, NFSv2/3 mounts first try an RPC bind to determine the
NFS server's port, unless the user specified the "port=" mount option;
Users can force the client to skip the RPC bind by explicitly specifying
"port=<value>".
NFSv4, by contrast, assumes the NFS server port is 2049 and skips the RPC
bind, unless the user specifies "port=". Users can force an RPC bind for
NFSv4 by explicitly specifying "port=0".
I added a couple of extra comments to clarify this behavior.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: use %u instead of %d when displaying NFS mount options.
Nit: Fix reporting of "namlen=" option in nfs_show_mount_stats. The mount
option is called "namlen" without the "e".
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS and SELinux worked together previously because SELinux had NFS
specific knowledge built in. This design was approved by both groups
back in 2004 but the recent NFS changes to use nfs_parsed_mount_data and
the usage of nfs_clone_mount_data showed this to be a poor fragile
solution. This patch fixes the NFS functionality regression by making
use of the new LSM interfaces to allow an FS to explicitly set its own
mount options.
The explicit setting of mount options is done in the nfs get_sb
functions which are called before the generic vfs hooks try to set mount
options for filesystems which use text mount data.
This does not currently support NFSv4 as that functionality did not
exist in previous kernels and thus there is no regression. I will be
adding the needed code, which I believe to be the exact same as the v3
code, in nfs4_get_sb for 2.6.26.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: James Morris <jmorris@namei.org>
* 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc: (22 commits)
Remove commented-out code copied from NFS
NFS: Switch from intr mount option to TASK_KILLABLE
Add wait_for_completion_killable
Add wait_event_killable
Add schedule_timeout_killable
Use mutex_lock_killable in vfs_readdir
Add mutex_lock_killable
Use lock_page_killable
Add lock_page_killable
Add fatal_signal_pending
Add TASK_WAKEKILL
exit: Use task_is_*
signal: Use task_is_*
sched: Use task_contributes_to_load, TASK_ALL and TASK_NORMAL
ptrace: Use task_is_*
power: Use task_is_*
wait: Use TASK_NORMAL
proc/base.c: Use task_is_*
proc/array.c: Use TASK_REPORT
perfmon: Use task_is_*
...
Fixed up conflicts in NFS/sunrpc manually..
