Commit Graph

36 Commits

Author SHA1 Message Date
Mark Johnston
68f6800ce0 opencrypto: Introduce crypto_dispatch_async()
Currently, OpenCrypto consumers can request asynchronous dispatch by
setting a flag in the cryptop.  (Currently only IPSec may do this.)   I
think this is a bit confusing: we (conditionally) set cryptop flags to
request async dispatch, and then crypto_dispatch() immediately examines
those flags to see if the consumer wants async dispatch. The flag names
are also confusing since they don't specify what "async" applies to:
dispatch or completion.

Add a new KPI, crypto_dispatch_async(), rather than encoding the
requested dispatch type in each cryptop. crypto_dispatch_async() falls
back to crypto_dispatch() if the session's driver provides asynchronous
dispatch. Get rid of CRYPTOP_ASYNC() and CRYPTOP_ASYNC_KEEPORDER().

Similarly, add crypto_dispatch_batch() to request processing of a tailq
of cryptops, rather than encoding the scheduling policy using cryptop
flags.  Convert GELI, the only user of this interface (disabled by
default) to use the new interface.

Add CRYPTO_SESS_SYNC(), which can be used by consumers to determine
whether crypto requests will be dispatched synchronously. This is just
a helper macro. Use it instead of looking at cap flags directly.

Fix style in crypto_done(). Also get rid of CRYPTO_RETW_EMPTY() and
just check the relevant queues directly. This could result in some
unnecessary wakeups but I think it's very uncommon to be using more than
one queue per worker in a given workload, so checking all three queues
is a waste of cycles.

Reviewed by:	jhb
Sponsored by:	Ampere Computing
Submitted by:	Klara, Inc.
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D28194
2021-02-08 09:19:19 -05:00
Konstantin Belousov
294c24b194 State kgssapi dependency on xdr.
Submitted by:	Dmitry Afanasiev
PR:	249378
MFC after:	3 days
2020-09-17 22:29:38 +00:00
Mateusz Guzik
b4a5336039 kgssapi: clean up empty lines in .c and .h files 2020-09-01 22:15:02 +00:00
John Baldwin
9c0e3d3a53 Add support for optional separate output buffers to in-kernel crypto.
Some crypto consumers such as GELI and KTLS for file-backed sendfile
need to store their output in a separate buffer from the input.
Currently these consumers copy the contents of the input buffer into
the output buffer and queue an in-place crypto operation on the output
buffer.  Using a separate output buffer avoids this copy.

- Create a new 'struct crypto_buffer' describing a crypto buffer
  containing a type and type-specific fields.  crp_ilen is gone,
  instead buffers that use a flat kernel buffer have a cb_buf_len
  field for their length.  The length of other buffer types is
  inferred from the backing store (e.g. uio_resid for a uio).
  Requests now have two such structures: crp_buf for the input buffer,
  and crp_obuf for the output buffer.

- Consumers now use helper functions (crypto_use_*,
  e.g. crypto_use_mbuf()) to configure the input buffer.  If an output
  buffer is not configured, the request still modifies the input
  buffer in-place.  A consumer uses a second set of helper functions
  (crypto_use_output_*) to configure an output buffer.

- Consumers must request support for separate output buffers when
  creating a crypto session via the CSP_F_SEPARATE_OUTPUT flag and are
  only permitted to queue a request with a separate output buffer on
  sessions with this flag set.  Existing drivers already reject
  sessions with unknown flags, so this permits drivers to be modified
  to support this extension without requiring all drivers to change.

- Several data-related functions now have matching versions that
  operate on an explicit buffer (e.g. crypto_apply_buf,
  crypto_contiguous_subsegment_buf, bus_dma_load_crp_buf).

- Most of the existing data-related functions operate on the input
  buffer.  However crypto_copyback always writes to the output buffer
  if a request uses a separate output buffer.

- For the regions in input/output buffers, the following conventions
  are followed:
  - AAD and IV are always present in input only and their
    fields are offsets into the input buffer.
  - payload is always present in both buffers.  If a request uses a
    separate output buffer, it must set a new crp_payload_start_output
    field to the offset of the payload in the output buffer.
  - digest is in the input buffer for verify operations, and in the
    output buffer for compute operations.  crp_digest_start is relative
    to the appropriate buffer.

- Add a crypto buffer cursor abstraction.  This is a more general form
  of some bits in the cryptosoft driver that tried to always use uio's.
  However, compared to the original code, this avoids rewalking the uio
  iovec array for requests with multiple vectors.  It also avoids
  allocate an iovec array for mbufs and populating it by instead walking
  the mbuf chain directly.

- Update the cryptosoft(4) driver to support separate output buffers
  making use of the cursor abstraction.

Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D24545
2020-05-25 22:12:04 +00:00
John Baldwin
dee3aa83d1 Remove support for Kernel GSS algorithms deprecated in r348875.
This removes support for using DES, Triple DES, and RC4.

Reviewed by:	cem, kp
Tested by:	kp
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D24344
2020-04-10 23:08:41 +00:00
John Baldwin
02cb5b4be8 Set crp_ilen for crypto requests.
Assertions in crypto_dispatch() depend on this value being set to
verify that payload and AAD regions are in bounds.  Also, requests
that use a single kernel buffer rely on this to know how long the
buffer is for bus_dma, etc.

Reported by:	kp
2020-04-01 17:09:21 +00:00
John Baldwin
c034143269 Refactor driver and consumer interfaces for OCF (in-kernel crypto).
- The linked list of cryptoini structures used in session
  initialization is replaced with a new flat structure: struct
  crypto_session_params.  This session includes a new mode to define
  how the other fields should be interpreted.  Available modes
  include:

  - COMPRESS (for compression/decompression)
  - CIPHER (for simply encryption/decryption)
  - DIGEST (computing and verifying digests)
  - AEAD (combined auth and encryption such as AES-GCM and AES-CCM)
  - ETA (combined auth and encryption using encrypt-then-authenticate)

  Additional modes could be added in the future (e.g. if we wanted to
  support TLS MtE for AES-CBC in the kernel we could add a new mode
  for that.  TLS modes might also affect how AAD is interpreted, etc.)

  The flat structure also includes the key lengths and algorithms as
  before.  However, code doesn't have to walk the linked list and
  switch on the algorithm to determine which key is the auth key vs
  encryption key.  The 'csp_auth_*' fields are always used for auth
  keys and settings and 'csp_cipher_*' for cipher.  (Compression
  algorithms are stored in csp_cipher_alg.)

- Drivers no longer register a list of supported algorithms.  This
  doesn't quite work when you factor in modes (e.g. a driver might
  support both AES-CBC and SHA2-256-HMAC separately but not combined
  for ETA).  Instead, a new 'crypto_probesession' method has been
  added to the kobj interface for symmteric crypto drivers.  This
  method returns a negative value on success (similar to how
  device_probe works) and the crypto framework uses this value to pick
  the "best" driver.  There are three constants for hardware
  (e.g. ccr), accelerated software (e.g. aesni), and plain software
  (cryptosoft) that give preference in that order.  One effect of this
  is that if you request only hardware when creating a new session,
  you will no longer get a session using accelerated software.
  Another effect is that the default setting to disallow software
  crypto via /dev/crypto now disables accelerated software.

  Once a driver is chosen, 'crypto_newsession' is invoked as before.

- Crypto operations are now solely described by the flat 'cryptop'
  structure.  The linked list of descriptors has been removed.

  A separate enum has been added to describe the type of data buffer
  in use instead of using CRYPTO_F_* flags to make it easier to add
  more types in the future if needed (e.g. wired userspace buffers for
  zero-copy).  It will also make it easier to re-introduce separate
  input and output buffers (in-kernel TLS would benefit from this).

  Try to make the flags related to IV handling less insane:

  - CRYPTO_F_IV_SEPARATE means that the IV is stored in the 'crp_iv'
    member of the operation structure.  If this flag is not set, the
    IV is stored in the data buffer at the 'crp_iv_start' offset.

  - CRYPTO_F_IV_GENERATE means that a random IV should be generated
    and stored into the data buffer.  This cannot be used with
    CRYPTO_F_IV_SEPARATE.

  If a consumer wants to deal with explicit vs implicit IVs, etc. it
  can always generate the IV however it needs and store partial IVs in
  the buffer and the full IV/nonce in crp_iv and set
  CRYPTO_F_IV_SEPARATE.

  The layout of the buffer is now described via fields in cryptop.
  crp_aad_start and crp_aad_length define the boundaries of any AAD.
  Previously with GCM and CCM you defined an auth crd with this range,
  but for ETA your auth crd had to span both the AAD and plaintext
  (and they had to be adjacent).

  crp_payload_start and crp_payload_length define the boundaries of
  the plaintext/ciphertext.  Modes that only do a single operation
  (COMPRESS, CIPHER, DIGEST) should only use this region and leave the
  AAD region empty.

  If a digest is present (or should be generated), it's starting
  location is marked by crp_digest_start.

  Instead of using the CRD_F_ENCRYPT flag to determine the direction
  of the operation, cryptop now includes an 'op' field defining the
  operation to perform.  For digests I've added a new VERIFY digest
  mode which assumes a digest is present in the input and fails the
  request with EBADMSG if it doesn't match the internally-computed
  digest.  GCM and CCM already assumed this, and the new AEAD mode
  requires this for decryption.  The new ETA mode now also requires
  this for decryption, so IPsec and GELI no longer do their own
  authentication verification.  Simple DIGEST operations can also do
  this, though there are no in-tree consumers.

  To eventually support some refcounting to close races, the session
  cookie is now passed to crypto_getop() and clients should no longer
  set crp_sesssion directly.

- Assymteric crypto operation structures should be allocated via
  crypto_getkreq() and freed via crypto_freekreq().  This permits the
  crypto layer to track open asym requests and close races with a
  driver trying to unregister while asym requests are in flight.

- crypto_copyback, crypto_copydata, crypto_apply, and
  crypto_contiguous_subsegment now accept the 'crp' object as the
  first parameter instead of individual members.  This makes it easier
  to deal with different buffer types in the future as well as
  separate input and output buffers.  It's also simpler for driver
  writers to use.

- bus_dmamap_load_crp() loads a DMA mapping for a crypto buffer.
  This understands the various types of buffers so that drivers that
  use DMA do not have to be aware of different buffer types.

- Helper routines now exist to build an auth context for HMAC IPAD
  and OPAD.  This reduces some duplicated work among drivers.

- Key buffers are now treated as const throughout the framework and in
  device drivers.  However, session key buffers provided when a session
  is created are expected to remain alive for the duration of the
  session.

- GCM and CCM sessions now only specify a cipher algorithm and a cipher
  key.  The redundant auth information is not needed or used.

- For cryptosoft, split up the code a bit such that the 'process'
  callback now invokes a function pointer in the session.  This
  function pointer is set based on the mode (in effect) though it
  simplifies a few edge cases that would otherwise be in the switch in
  'process'.

  It does split up GCM vs CCM which I think is more readable even if there
  is some duplication.

- I changed /dev/crypto to support GMAC requests using CRYPTO_AES_NIST_GMAC
  as an auth algorithm and updated cryptocheck to work with it.

- Combined cipher and auth sessions via /dev/crypto now always use ETA
  mode.  The COP_F_CIPHER_FIRST flag is now a no-op that is ignored.
  This was actually documented as being true in crypto(4) before, but
  the code had not implemented this before I added the CIPHER_FIRST
  flag.

- I have not yet updated /dev/crypto to be aware of explicit modes for
  sessions.  I will probably do that at some point in the future as well
  as teach it about IV/nonce and tag lengths for AEAD so we can support
  all of the NIST KAT tests for GCM and CCM.

- I've split up the exising crypto.9 manpage into several pages
  of which many are written from scratch.

- I have converted all drivers and consumers in the tree and verified
  that they compile, but I have not tested all of them.  I have tested
  the following drivers:

  - cryptosoft
  - aesni (AES only)
  - blake2
  - ccr

  and the following consumers:

  - cryptodev
  - IPsec
  - ktls_ocf
  - GELI (lightly)

  I have not tested the following:

  - ccp
  - aesni with sha
  - hifn
  - kgssapi_krb5
  - ubsec
  - padlock
  - safe
  - armv8_crypto (aarch64)
  - glxsb (i386)
  - sec (ppc)
  - cesa (armv7)
  - cryptocteon (mips64)
  - nlmsec (mips64)

Discussed with:	cem
Relnotes:	yes
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D23677
2020-03-27 18:25:23 +00:00
John Baldwin
87210a0c6d Stop using des_cblock * for arguments to DES functions.
This amounts to a char ** since it is a char[8] *.  Evil casts mostly
resolved the fact that what was actually passed in were plain char *.
Instead, change the DES functions to use 'unsigned char *' for keys
and for input and output buffers.

Reviewed by:	cem, imp
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D21389
2019-08-26 17:25:07 +00:00
John Baldwin
0f70218343 Make the warning intervals for deprecated crypto algorithms tunable.
New sysctl/tunables can now set the interval (in seconds) between
rate-limited crypto warnings.  The new sysctls are:
- kern.cryptodev_warn_interval for /dev/crypto
- net.inet.ipsec.crypto_warn_interval for IPsec
- kern.kgssapi_warn_interval for KGSSAPI

Reviewed by:	cem
MFC after:	1 month
Relnotes:	yes
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D20555
2019-06-11 23:00:55 +00:00
John Baldwin
db4709c579 Add warnings for Kerberos GSS algorithms deprecated in RFCs 6649 and 8429.
All of these algorithms are explicitly marked SHOULD NOT in one of these
RFCs.

Specifically, RFC 6649 deprecates all algorithms using DES as well as
the "export-friendly" variant of RC4.  RFC 8429 deprecates Triple DES
and the remaining RC4 algorithms.

Reviewed by:	cem
MFC after:	1 month
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D20343
2019-06-10 19:22:36 +00:00
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
1b0909d51a OpenCrypto: Convert sessions to opaque handles instead of integers
Track session objects in the framework, and pass handles between the
framework (OCF), consumers, and drivers.  Avoid redundancy and complexity in
individual drivers by allocating session memory in the framework and
providing it to drivers in ::newsession().

Session handles are no longer integers with information encoded in various
high bits.  Use of the CRYPTO_SESID2FOO() macros should be replaced with the
appropriate crypto_ses2foo() function on the opaque session handle.

Convert OCF drivers (in particular, cryptosoft, as well as myriad others) to
the opaque handle interface.  Discard existing session tracking as much as
possible (quick pass).  There may be additional code ripe for deletion.

Convert OCF consumers (ipsec, geom_eli, krb5, cryptodev) to handle-style
interface.  The conversion is largely mechnical.

The change is documented in crypto.9.

Inspired by
https://lists.freebsd.org/pipermail/freebsd-arch/2018-January/018835.html .

No objection from:	ae (ipsec portion)
Reported by:	jhb
2018-07-18 00:56:25 +00:00
Conrad Meyer
1df7f41560 OCF: Convert consumers to the session id typedef
These were missed in the earlier r336269.

No functional change.

Sponsored by:	Dell EMC Isilon
2018-07-16 19:01:05 +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
Pedro F. Giffuni
696efc839c kgssapi: insignificant spelling fix.
No functional change.
2016-05-03 22:05:03 +00:00
Conrad Meyer
be0edef163 kgssapi: Don't leak memory in error cases
Reported by:	Coverity
CIDs:		1007046, 1007047, 1007048
Sponsored by:	EMC / Isilon Storage Division
2016-04-26 18:11:45 +00:00
Pedro F. Giffuni
55e0987aea sys: extend use of the howmany() macro when available.
We have a howmany() macro in the <sys/param.h> header that is
convenient to re-use as it makes things easier to read.
2016-04-26 15:38:17 +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
Conrad Meyer
92deafc3a3 kcrypto_aes: Use separate sessions for AES and SHA1
Some hardware supports AES acceleration but not SHA1, e.g., AES-NI
extensions.  It is useful to have accelerated AES even if SHA1 must be
software.

Suggested by:	asomers
Reviewed by:	asomers, dfr
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D5146
2016-02-02 00:14:51 +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
58217793a2 Isilon reported that sec=krb5p NFS mounts had a problem when m_len == 0
for the last mbuf of the list with an encrypted message. This patch replaces
the KASSERT() with code that handles this case.

Reported by:	john.gemignani@isilon.com
Reviewed by:	jhb
MFC after:	2 weeks
2013-05-01 22:07:55 +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
Christian Brueffer
e275052c56 Add missing break statement to make sure all 3DES etypes really are treated
the same.

CID:		3624
Found with:	Coverity Prevent(tm)
Reviewed by:	dfr
MFC after:	1 week
2011-10-10 09:13:07 +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
Rick Macklem
f0557704cf When the KOBJMETHOD() macro was updated, it resulted in the
compiler doing argument type checking. Since the prototypes in
kgss_if.h used the generic gss_ctx_id_t for the context argument,
but the functions in sys/kgssapi/krb5/krb5_mech.c used the
KerberosV specific context argument, the file would no longer build.
This patch fixes it so it will build by replacing the argument with
a gss_ctx_id_t one and setting a local "struct krb5_context *" variable
to it for use by the function.

Reviewed by:	dfr
Approved by:	kib (mentor)
2009-06-14 17:33:46 +00:00
Jamie Gritton
76ca6f88da Place hostnames and similar information fully under the prison system.
The system hostname is now stored in prison0, and the global variable
"hostname" has been removed, as has the hostname_mtx mutex.  Jails may
have their own host information, or they may inherit it from the
parent/system.  The proper way to read the hostname is via
getcredhostname(), which will copy either the hostname associated with
the passed cred, or the system hostname if you pass NULL.  The system
hostname can still be accessed directly (and without locking) at
prison0.pr_host, but that should be avoided where possible.

The "similar information" referred to is domainname, hostid, and
hostuuid, which have also become prison parameters and had their
associated global variables removed.

Approved by:	bz (mentor)
2009-05-29 21:27:12 +00:00
Doug Rabson
57d8181b40 Fix build of KGSSAPI bits post-vimage. 2009-05-24 11:10:27 +00:00
Doug Rabson
44ab20591b Call svc_freereq() before returning from the service proc. 2008-11-12 15:31:05 +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