Commit Graph

38 Commits

Author SHA1 Message Date
Herbert Xu
1822793a52 crypto: algif_skcipher - Fix race condition in skcipher_check_key
We need to lock the child socket in skcipher_check_key as otherwise
two simultaneous calls can cause the parent socket to be freed.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-01-18 18:16:34 +08:00
Herbert Xu
d7b65aee1e crypto: algif_skcipher - Remove custom release parent function
This patch removes the custom release parent function as the
generic af_alg_release_parent now works for nokey sockets too.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-01-18 18:16:33 +08:00
Herbert Xu
6e8d8ecf43 crypto: algif_skcipher - Add key check exception for cipher_null
This patch adds an exception to the key check so that cipher_null
users may continue to use algif_skcipher without setting a key.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-01-18 18:16:12 +08:00
Herbert Xu
a0fa2d0371 crypto: algif_skcipher - Add nokey compatibility path
This patch adds a compatibility path to support old applications
that do acept(2) before setkey.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-01-18 18:16:11 +08:00
Herbert Xu
dd50458957 crypto: algif_skcipher - Require setkey before accept(2)
Some cipher implementations will crash if you try to use them
without calling setkey first.  This patch adds a check so that
the accept(2) call will fail with -ENOKEY if setkey hasn't been
done on the socket yet.

Cc: stable@vger.kernel.org
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
2016-01-18 18:16:07 +08:00
Linus Torvalds
c597b6bcd5 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu:
 "Algorithms:
   - Add RSA padding algorithm

  Drivers:
   - Add GCM mode support to atmel
   - Add atmel support for SAMA5D2 devices
   - Add cipher modes to talitos
   - Add rockchip driver for rk3288
   - Add qat support for C3XXX and C62X"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (103 commits)
  crypto: hifn_795x, picoxcell - use ablkcipher_request_cast
  crypto: qat - fix SKU definiftion for c3xxx dev
  crypto: qat - Fix random config build issue
  crypto: ccp - use to_pci_dev and to_platform_device
  crypto: qat - Rename dh895xcc mmp firmware
  crypto: 842 - remove WARN inside printk
  crypto: atmel-aes - add debug facilities to monitor register accesses.
  crypto: atmel-aes - add support to GCM mode
  crypto: atmel-aes - change the DMA threshold
  crypto: atmel-aes - fix the counter overflow in CTR mode
  crypto: atmel-aes - fix atmel-ctr-aes driver for RFC 3686
  crypto: atmel-aes - create sections to regroup functions by usage
  crypto: atmel-aes - fix typo and indentation
  crypto: atmel-aes - use SIZE_IN_WORDS() helper macro
  crypto: atmel-aes - improve performances of data transfer
  crypto: atmel-aes - fix atmel_aes_remove()
  crypto: atmel-aes - remove useless AES_FLAGS_DMA flag
  crypto: atmel-aes - reduce latency of DMA completion
  crypto: atmel-aes - remove unused 'err' member of struct atmel_aes_dev
  crypto: atmel-aes - rework crypto request completion
  ...
2016-01-12 18:51:14 -08:00
Linus Torvalds
8513342170 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fix from Herbert Xu:
 "This fixes a bug in the algif_skcipher interface that can trigger a
  kernel WARN_ON from user-space.  It does so by using the new skcipher
  interface which unlike the previous ablkcipher does not need to create
  extra geniv objects which is what was used to trigger the WARN_ON"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: algif_skcipher - Use new skcipher interface
2015-12-28 10:44:41 -08:00
Herbert Xu
0d96e4bab2 crypto: algif_skcipher - Use new skcipher interface
This patch replaces uses of ablkcipher with the new skcipher
interface.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: <smueller@chronox.de>
2015-12-22 20:40:01 +08:00
Eric Dumazet
9cd3e072b0 net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA
This patch is a cleanup to make following patch easier to
review.

Goal is to move SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA
from (struct socket)->flags to a (struct socket_wq)->flags
to benefit from RCU protection in sock_wake_async()

To ease backports, we rename both constants.

Two new helpers, sk_set_bit(int nr, struct sock *sk)
and sk_clear_bit(int net, struct sock *sk) are added so that
following patch can change their implementation.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01 15:45:05 -05:00
LABBE Corentin
652d5b8a8d crypto: algif - Change some variable to size_t
Some variable are set as int but store only positive values.
Furthermore there are used in operation/function that wait for unsigned
value.
This patch set them as size_t.

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-11-17 21:58:37 +08:00
Dan Williams
c56f6d1270 crypto: replace scatterwalk_sg_chain with sg_chain
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
[hch: split from a larger patch by Dan]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-17 08:12:54 -06:00
Al Viro
01e97e6517 new helper: msg_data_left()
convert open-coded instances

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 15:53:35 -04:00
Al Viro
237dae8890 Merge branch 'iocb' into for-davem
trivial conflict in net/socket.c and non-trivial one in crypto -
that one had evaded aio_complete() removal.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-09 00:01:38 -04:00
tadeusz.struk@intel.com
033f46b3c1 crypto: algif - explicitly mark end of data
After the TX sgl is expanded we need to explicitly mark end of data
at the last buffer that contains data.

Changes in v2
 - use type 'bool' and true/false for 'mark'.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-01 22:59:28 -04:00
Tadeusz Struk
82d929207a crypto: algif - use kmalloc instead of kzalloc
No need to use kzalloc to allocate sgls as the structure is initialized anyway.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-01 15:32:35 -04:00
tadeusz.struk@intel.com
ac110f4954 crypto: algif - fix warn: unsigned 'used' is never less than zero
Change type from unsigned long to int to fix an issue reported by kbuild robot:
crypto/algif_skcipher.c:596 skcipher_recvmsg_async() warn: unsigned 'used' is
never less than zero.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-25 11:44:18 -04:00
Tadeusz Struk
a596999b7d crypto: algif - change algif_skcipher to be asynchronous
The way the algif_skcipher works currently is that on sendmsg/sendpage it
builds an sgl for the input data and then on read/recvmsg it sends the job
for encryption putting the user to sleep till the data is processed.
This way it can only handle one job at a given time.
This patch changes it to be asynchronous by adding AIO support.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23 16:41:37 -04:00
Ying Xue
1b78414047 net: Remove iocb argument from sendmsg and recvmsg
After TIPC doesn't depend on iocb argument in its internal
implementations of sendmsg() and recvmsg() hooks defined in proto
structure, no any user is using iocb argument in them at all now.
Then we can drop the redundant iocb argument completely from kinds of
implementations of both sendmsg() and recvmsg() in the entire
networking stack.

Cc: Christoph Hellwig <hch@lst.de>
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-02 13:06:31 -05:00
Linus Torvalds
fee5429e02 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu:
 "Here is the crypto update for 3.20:

   - Added 192/256-bit key support to aesni GCM.
   - Added MIPS OCTEON MD5 support.
   - Fixed hwrng starvation and race conditions.
   - Added note that memzero_explicit is not a subsitute for memset.
   - Added user-space interface for crypto_rng.
   - Misc fixes"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (71 commits)
  crypto: tcrypt - do not allocate iv on stack for aead speed tests
  crypto: testmgr - limit IV copy length in aead tests
  crypto: tcrypt - fix buflen reminder calculation
  crypto: testmgr - mark rfc4106(gcm(aes)) as fips_allowed
  crypto: caam - fix resource clean-up on error path for caam_jr_init
  crypto: caam - pair irq map and dispose in the same function
  crypto: ccp - terminate ccp_support array with empty element
  crypto: caam - remove unused local variable
  crypto: caam - remove dead code
  crypto: caam - don't emit ICV check failures to dmesg
  hwrng: virtio - drop extra empty line
  crypto: replace scatterwalk_sg_next with sg_next
  crypto: atmel - Free memory in error path
  crypto: doc - remove colons in comments
  crypto: seqiv - Ensure that IV size is at least 8 bytes
  crypto: cts - Weed out non-CBC algorithms
  MAINTAINERS: add linux-crypto to hw random
  crypto: cts - Remove bogus use of seqiv
  crypto: qat - don't need qat_auth_state struct
  crypto: algif_rng - fix sparse non static symbol warning
  ...
2015-02-14 09:47:01 -08:00
Linus Torvalds
9399f0c514 crypto: fix af_alg_make_sg() conversion to iov_iter
Commit 1d10eb2f15 ("crypto: switch af_alg_make_sg() to iov_iter")
broke af_alg_make_sg() and skcipher_recvmsg() in the process of moving
them to the iov_iter interfaces.  The 'npages' calculation in the formar
calculated the number of *bytes* in the pages, and in the latter case
the conversion didn't re-read the value of 'ctx->used' after waiting for
it to become non-zero.

This reverts to the original code for both these cases.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10 19:55:45 -08:00
Al Viro
1d10eb2f15 crypto: switch af_alg_make_sg() to iov_iter
With that, all ->sendmsg() instances are converted to iov_iter primitives
and are agnostic wrt the kind of iov_iter they are working with.
So's the last remaining ->recvmsg() instance that wasn't kind-agnostic yet.
All ->sendmsg() and ->recvmsg() advance ->msg_iter by the amount actually
copied and none of them modifies the underlying iovec, etc.

Cc: linux-crypto@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-04 01:34:15 -05:00
Tadeusz Struk
0f477b655a crypto: algif - Mark sgl end at the end of data
algif_skcipher sends 127 sgl buffers for encryption regardless of how
many buffers acctually have data to process, where the few first with
valid len and the rest with zero len. This is not very eficient.
This patch marks the last one with data as the last one to process.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-12-22 23:02:41 +11:00
Linus Torvalds
e3aa91a7cb Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu:
 - The crypto API is now documented :)
 - Disallow arbitrary module loading through crypto API.
 - Allow get request with empty driver name through crypto_user.
 - Allow speed testing of arbitrary hash functions.
 - Add caam support for ctr(aes), gcm(aes) and their derivatives.
 - nx now supports concurrent hashing properly.
 - Add sahara support for SHA1/256.
 - Add ARM64 version of CRC32.
 - Misc fixes.

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (77 commits)
  crypto: tcrypt - Allow speed testing of arbitrary hash functions
  crypto: af_alg - add user space interface for AEAD
  crypto: qat - fix problem with coalescing enable logic
  crypto: sahara - add support for SHA1/256
  crypto: sahara - replace tasklets with kthread
  crypto: sahara - add support for i.MX53
  crypto: sahara - fix spinlock initialization
  crypto: arm - replace memset by memzero_explicit
  crypto: powerpc - replace memset by memzero_explicit
  crypto: sha - replace memset by memzero_explicit
  crypto: sparc - replace memset by memzero_explicit
  crypto: algif_skcipher - initialize upon init request
  crypto: algif_skcipher - removed unneeded code
  crypto: algif_skcipher - Fixed blocking recvmsg
  crypto: drbg - use memzero_explicit() for clearing sensitive data
  crypto: drbg - use MODULE_ALIAS_CRYPTO
  crypto: include crypto- module prefix in template
  crypto: user - add MODULE_ALIAS
  crypto: sha-mb - remove a bogus NULL check
  crytpo: qat - Fix 64 bytes requests
  ...
2014-12-13 13:33:26 -08:00
Al Viro
c0371da604 put iov_iter into msghdr
Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-09 16:29:03 -05:00
Stephan Mueller
f26b7b8052 crypto: algif_skcipher - initialize upon init request
When using the algif_skcipher, the following call sequence causess a
re-initialization:

1. sendmsg with ALG_SET_OP and iov == NULL, iovlen == 0 (i.e
initializing the cipher, but not sending data)

2. sendmsg with msg->msg-controllen == 0 and iov != NULL (using the initalized
cipher handle by sending data)

In step 2, the cipher operation type (encryption or decryption) is reset
to always decryption, because the local variable of enc is put into
ctx->enc as ctx->user is still zero.

The same applies when all send data is processed and ctx->used falls to
zero followed by user space to send new data.

This patch changes the behavior to only reset the cipher operation type
(and the IV) if such configuration request is received.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-12-02 22:55:46 +08:00
Struk, Tadeusz
9ba0905f17 crypto: algif_skcipher - removed unneeded code
Remover unneeded code.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-12-01 22:42:48 +08:00
Herbert Xu
1e104f9a25 crypto: algif_skcipher - Fixed blocking recvmsg
As most (all?) users of algif_skcipher are single-threaded and
therefore always write before reading from an algif_skcipher
socket, they never block and exercise that code-path.

It turns out that code path doesn't even work because we never
reload ctx->used after waking up so we never even see the new
data and immediately return an error (and a loud WARN_ON).

This patch fixes this by always reloading ctx->used.

Reported-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Stephan Mueller <smueller@chronox.de>
2014-11-28 23:33:18 +08:00
Daniel Borkmann
79e886599e crypto: algif - add and use sock_kzfree_s() instead of memzero_explicit()
Commit e1bd95bf7c ("crypto: algif - zeroize IV buffer") and
2a6af25bef ("crypto: algif - zeroize message digest buffer")
added memzero_explicit() calls on buffers that are later on
passed back to sock_kfree_s().

This is a discussed follow-up that, instead, extends the sock
API and adds sock_kzfree_s(), which internally uses kzfree()
instead of kfree() for passing the buffers back to slab.

Having sock_kzfree_s() allows to keep the changes more minimal
by just having a drop-in replacement instead of adding
memzero_explicit() calls everywhere before sock_kfree_s().

In kzfree(), the compiler is not allowed to optimize the memset()
away and thus there's no need for memzero_explicit(). Both,
sock_kfree_s() and sock_kzfree_s() are wrappers for
__sock_kfree_s() and call into kfree() resp. kzfree(); here,
__sock_kfree_s() needs to be explicitly inlined as we want the
compiler to optimize the call and condition away and thus it
produces e.g. on x86_64 the _same_ assembler output for
sock_kfree_s() before and after, and thus also allows for
avoiding code duplication.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-11-25 22:50:39 +08:00
Al Viro
6ce8e9ce59 new helper: memcpy_from_msg()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-24 04:28:48 -05:00
Stephan Mueller
e1bd95bf7c crypto: algif - zeroize IV buffer
Zeroize the buffer holding the IV used for the completed
cipher operation before the buffer is released by the
skcipher AF_ALG interface handler.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-11-12 22:14:31 +08:00
Ondrej Kozina
e2cffb5f49 crypto: algif - avoid excessive use of socket buffer in skcipher
On archs with PAGE_SIZE >= 64 KiB the function skcipher_alloc_sgl()
fails with -ENOMEM no matter what user space actually requested.
This is caused by the fact sock_kmalloc call inside the function tried
to allocate more memory than allowed by the default kernel socket buffer
size (kernel param net.core.optmem_max).

Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-09-04 15:07:10 +08:00
Shawn Landden
d3f7d56a7a net: update consumers of MSG_MORE to recognize MSG_SENDPAGE_NOTLAST
Commit 35f9c09fe (tcp: tcp_sendpages() should call tcp_push() once)
added an internal flag MSG_SENDPAGE_NOTLAST, similar to
MSG_MORE.

algif_hash, algif_skcipher, and udp used MSG_MORE from tcp_sendpages()
and need to see the new flag as identical to MSG_MORE.

This fixes sendfile() on AF_ALG.

v3: also fix udp

Cc: Tom Herbert <therbert@google.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org> # 3.4.x + 3.2.x
Reported-and-tested-by: Shawn Landden <shawnlandden@gmail.com>
Original-patch: Richard Weinberger <richard@nod.at>
Signed-off-by: Shawn Landden <shawn@churchofgit.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-29 16:32:54 -05:00
Hannes Frederic Sowa
f3d3342602 net: rework recvmsg handler msg_name and msg_namelen logic
This patch now always passes msg->msg_namelen as 0. recvmsg handlers must
set msg_namelen to the proper size <= sizeof(struct sockaddr_storage)
to return msg_name to the user.

This prevents numerous uninitialized memory leaks we had in the
recvmsg handlers and makes it harder for new code to accidentally leak
uninitialized memory.

Optimize for the case recvfrom is called with NULL as address. We don't
need to copy the address at all, so set it to NULL before invoking the
recvmsg handler. We can do so, because all the recvmsg handlers must
cope with the case a plain read() is called on them. read() also sets
msg_name to NULL.

Also document these changes in include/linux/net.h as suggested by David
Miller.

Changes since RFC:

Set msg->msg_name = NULL if user specified a NULL in msg_name but had a
non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't
affect sendto as it would bail out earlier while trying to copy-in the
address. It also more naturally reflects the logic by the callers of
verify_iovec.

With this change in place I could remove "
if (!uaddr || msg_sys->msg_namelen == 0)
	msg->msg_name = NULL
".

This change does not alter the user visible error logic as we ignore
msg_namelen as long as msg_name is NULL.

Also remove two unnecessary curly brackets in ___sys_recvmsg and change
comments to netdev style.

Cc: David Miller <davem@davemloft.net>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-20 21:52:30 -05:00
Mathias Krause
72a763d805 crypto: algif - suppress sending source address information in recvmsg
The current code does not set the msg_namelen member to 0 and therefore
makes net/socket.c leak the local sockaddr_storage variable to userland
-- 128 bytes of kernel stack memory. Fix that.

Cc: <stable@vger.kernel.org> # 2.6.38
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-04-10 14:26:06 +08:00
Herbert Xu
bc97e57eb2 crypto: algif_skcipher - Handle unaligned receive buffer
As it is if user-space passes through a receive buffer that's not
aligned to to the cipher block size, we'll end up encrypting or
decrypting a partial block which causes a spurious EINVAL to be
returned.

This patch fixes this by moving the partial block test after the
af_alg_make_sg call.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-11-30 17:04:31 +08:00
Herbert Xu
0f6bb83cb1 crypto: algif_skcipher - Fixed overflow when sndbuf is page aligned
When sk_sndbuf is not a multiple of PAGE_SIZE, the limit tests
in sendmsg fail as the limit variable becomes negative and we're
using an unsigned comparison.

The same thing can happen if sk_sndbuf is lowered after a sendmsg
call.

This patch fixes this by always taking the signed maximum of limit
and 0 before we perform the comparison.

It also rounds the value of sk_sndbuf down to a multiple of PAGE_SIZE
so that we don't end up allocating a page only to use a small number
of bytes in it because we're bound by sk_sndbuf.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-11-30 16:49:02 +08:00
Herbert Xu
c762be6375 crypto: algif_skcipher - Pass on error from af_alg_make_sg
The error returned from af_alg_make_sg is currently lost and we
always pass on -EINVAL.  This patch pases on the underlying error.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-11-28 16:28:01 +08:00
Herbert Xu
8ff590903d crypto: algif_skcipher - User-space interface for skcipher operations
This patch adds the af_alg plugin for symmetric key ciphers,
corresponding to the ablkcipher kernel operation type.

Keys can optionally be set through the setsockopt interface.

Once a sendmsg call occurs without MSG_MORE no further writes
may be made to the socket until all previous data has been read.

IVs and and whether encryption/decryption is performed can be
set through the setsockopt interface or as a control message
to sendmsg.

The interface is completely synchronous, all operations are
carried out in recvmsg(2) and will complete prior to the system
call returning.

The splice(2) interface support reading the user-space data directly
without copying (except that the Crypto API itself may copy the data
if alignment is off).

The recvmsg(2) interface supports directly writing to user-space
without additional copying, i.e., the kernel crypto interface will
receive the user-space address as its output SG list.

Thakns to Miloslav Trmac for reviewing this and contributing
fixes and improvements.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: David S. Miller <davem@davemloft.net>
2010-11-26 20:53:59 +08:00