Commit Graph

14 Commits

Author SHA1 Message Date
Sean Eric Fagan
c6da8eb21f * Handle SIGPIPE in gssd
We've got some cases where the other end of gssd's AF_LOCAL socket gets
closed, resulting in an error (and SIGPIPE) when it tries to do I/O to it.
Closing without cleaning up means the next time nfsd starts up, it hangs,
unkillably; this allows gssd to handle that particular error.

* Limit the retry cound in gssd_syscall to 5.
The default is INT_MAX, which effectively means forever.  And it's an
uninterruptable RPC call, so it will never stop.

The two changes mitigate the problem.

Reviewed by:	macklem
MFC after:	2 weeks
Sponsored by:	iXsystems Inc.
Differential Revision:	https://reviews.freebsd.org/D19153
2019-02-21 01:30:37 +00:00
Conrad Meyer
a4f2dfa6fa kgssapi: Remove trivial deadcode
CID:		1385956
Reported by:	Coverity
Sponsored by:	Dell EMC Isilon
2018-02-14 00:12:03 +00:00
Brooks Davis
ad704a34bc Use syscall_helper_register(9) rather than syscall_register().
The usage is simpler, documented, and more common.

Reviewed by:	cem
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14227
2018-02-11 18:37:08 +00:00
Pedro F. Giffuni
4de8ade94c sys/kgssapi: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.
2017-11-27 15:49:00 +00:00
Conrad Meyer
9d77679a40 kgssapi(4): Don't allow user-provided arguments to overrun stack buffer
An over-long path argument to gssd_syscall could overrun the stack sockaddr_un
buffer.  Fix gssd_syscall to not permit that.

If an over-long path is provided, gssd_syscall now returns EINVAL.

It looks like PRIV_NFS_DAEMON isn't granted anywhere, so my best guess is that
this is likely only triggerable by root.

Reported by:	Coverity
CID:		1006751
Sponsored by:	EMC / Isilon Storage Division
2016-04-20 05:02:13 +00:00
Pedro F. Giffuni
74b8d63dcc Cleanup unnecessary semicolons from the kernel.
Found with devel/coccinelle.
2016-04-10 23:07:00 +00:00
Josh Paetzel
21d7e927b5 Unset the gss kernel state when gssd exits
When gssd exits it leaves the kernel state set by
gssd_syscall().  nfsd sees this and waits endlessly
in an unkillable state for gssd to come back.  If you
had acidentally started gssd then stopped it, then
started nfsd you'd be in a bad way until you either
restarted gssd or rebooted the system.  This change
fixes that by setting the kernel state to "" when
gssd exits.
Reviewed by:	rmacklem
MFC after:	1 week
Sponsored by:	iXsystems
2016-01-01 17:06:16 +00:00
Mateusz Guzik
e015b1ab0a Avoid dynamic syscall overhead for statically compiled modules.
The kernel tracks syscall users so that modules can safely unregister them.

But if the module is not unloadable or was compiled into the kernel, there is
no need to do this.

Achieve this by adding SY_THR_STATIC_KLD macro which expands to SY_THR_STATIC
during kernel build and 0 otherwise.

Reviewed by:	kib (previous version)
MFC after:	2 weeks
2014-10-26 19:42:44 +00:00
Rick Macklem
88a2437a65 Add support for host-based (Kerberos 5 service principal) initiator
credentials to the kernel rpc. Modify the NFSv4 client to add
support for the gssname and allgssname mount options to use this
capability. Requires the gssd daemon to be running with the "-h" option.

Reviewed by:	jhb
2013-07-09 01:05:28 +00:00
Rick Macklem
13870d5d7b Piete.Brooks at cl.cam.ac.uk reported via email a crash which was
caused by use of an invalid kgss_gssd_handle during an upcall to
the gssd daemon when it has exited. This patch seems to avoid the
crashes by holding a reference count on the kgss_gssd_handle until
the upcall is done. It also adds a new mutex kgss_gssd_lock used to
make manipulation of kgss_gssd_handle SMP safe.

Tested by:	Illias A. Marinos, Herbert Poeckl
Reviewed by:	jhb
MFC after:	2 weeks
2012-12-18 00:25:48 +00:00
Kip Macy
8451d0dd78 In order to maximize the re-usability of kernel code in user space this
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.

Reviewed by:	rwatson
Approved by:	re (bz)
2011-09-16 13:58:51 +00:00
Zack Kirsch
dcded131e1 Add a small comment about unloading the kgsappi module.
Reviewed by:    rmacklem
Approved by:    zml (mentor)
MFC after:      2 weeks
2011-07-16 08:05:49 +00:00
Rick Macklem
7e7fd7d177 Fix the kgssapi so that it can be loaded as a module. Currently
the NFS subsystems use five of the rpcsec_gss/kgssapi entry points,
but since it was not obvious which others might be useful, all
nineteen were included. Basically the nineteen entry points are
set in a structure called rpc_gss_entries and inline functions
defined in sys/rpc/rpcsec_gss.h check for the entry points being
non-NULL and then call them. A default value is returned otherwise.
Requested by rwatson.

Reviewed by:	jhb
MFC after:	2 weeks
2011-06-19 22:08:55 +00:00
Doug Rabson
a9148abd9d Implement support for RPCSEC_GSS authentication to both the NFS client
and server. This replaces the RPC implementation of the NFS client and
server with the newer RPC implementation originally developed
(actually ported from the userland sunrpc code) to support the NFS
Lock Manager.  I have tested this code extensively and I believe it is
stable and that performance is at least equal to the legacy RPC
implementation.

The NFS code currently contains support for both the new RPC
implementation and the older legacy implementation inherited from the
original NFS codebase. The default is to use the new implementation -
add the NFS_LEGACYRPC option to fall back to the old code. When I
merge this support back to RELENG_7, I will probably change this so
that users have to 'opt in' to get the new code.

To use RPCSEC_GSS on either client or server, you must build a kernel
which includes the KGSSAPI option and the crypto device. On the
userland side, you must build at least a new libc, mountd, mount_nfs
and gssd. You must install new versions of /etc/rc.d/gssd and
/etc/rc.d/nfsd and add 'gssd_enable=YES' to /etc/rc.conf.

As long as gssd is running, you should be able to mount an NFS
filesystem from a server that requires RPCSEC_GSS authentication. The
mount itself can happen without any kerberos credentials but all
access to the filesystem will be denied unless the accessing user has
a valid ticket file in the standard place (/tmp/krb5cc_<uid>). There
is currently no support for situations where the ticket file is in a
different place, such as when the user logged in via SSH and has
delegated credentials from that login. This restriction is also
present in Solaris and Linux. In theory, we could improve this in
future, possibly using Brooks Davis' implementation of variant
symlinks.

Supporting RPCSEC_GSS on a server is nearly as simple. You must create
service creds for the server in the form 'nfs/<fqdn>@<REALM>' and
install them in /etc/krb5.keytab. The standard heimdal utility ktutil
makes this fairly easy. After the service creds have been created, you
can add a '-sec=krb5' option to /etc/exports and restart both mountd
and nfsd.

The only other difference an administrator should notice is that nfsd
doesn't fork to create service threads any more. In normal operation,
there will be two nfsd processes, one in userland waiting for TCP
connections and one in the kernel handling requests. The latter
process will create as many kthreads as required - these should be
visible via 'top -H'. The code has some support for varying the number
of service threads according to load but initially at least, nfsd uses
a fixed number of threads according to the value supplied to its '-n'
option.

Sponsored by:	Isilon Systems
MFC after:	1 month
2008-11-03 10:38:00 +00:00