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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2016, Datto, Inc. All rights reserved.
*/
#ifdef _KERNEL
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#else
#define __exit
#define __init
#endif
#include <sys/crypto/common.h>
#include <sys/crypto/api.h>
#include <sys/crypto/impl.h>
#include <sys/crypto/sched_impl.h>
#include <sys/modhash_impl.h>
#include <sys/crypto/icp.h>
/*
* Changes made to the original Illumos Crypto Layer for the ICP:
*
* Several changes were needed to allow the Illumos Crypto Layer
* to work in the Linux kernel. Almost all of the changes fall into
* one of the following categories:
*
* 1) Moving the syntax to the C90: This was mostly a matter of
* changing func() definitions to func(void). In a few cases,
* initializations of structs with unions needed to have brackets
* added.
*
* 2) Changes to allow userspace compilation: The ICP is meant to be
* compiled and used in both userspace and kernel space (for ztest and
* libzfs), so the _KERNEL macros did not make sense anymore. For the
* same reason, many header includes were also changed to use
* sys/zfs_context.h
*
* 3) Moving to a statically compiled architecture: At some point in
* the future it may make sense to have encryption algorithms that are
* loadable into the ICP at runtime via separate kernel modules.
* However, considering that this code will probably not see much use
* outside of zfs and zfs encryption only requires aes and sha256
* algorithms it seemed like more trouble than it was worth to port over
* Illumos's kernel module structure to a Linux kernel module. In
* addition, The Illumos code related to keeping track of kernel modules
* is very much tied to the Illumos OS and proved difficult to port to
* Linux. Therefore, the structure of the ICP was simplified to work
* statically and several pieces of code responsible for keeping track
* of Illumos kernel modules were removed and simplified. All module
* initialization and destruction is now called in this file during
* Linux kernel module loading and unloading.
*
* 4) Adding destructors: The Illumos Crypto Layer is built into
* the Illumos kernel and is not meant to be unloaded. Some destructors
* were added to allow the ICP to be unloaded without leaking
* structures.
*
* 5) Removing CRYPTO_DATA_MBLK related structures and code:
* crypto_data_t can have 3 formats, CRYPTO_DATA_RAW, CRYPTO_DATA_UIO,
* and CRYPTO_DATA_MBLK. ZFS only requires the first 2 formats, as the
* last one is related to streamed data. To simplify the port, code
* related to this format was removed.
*
* 6) Changes for architecture specific code: Some changes were needed
* to make architecture specific assembly compile. The biggest change
* here was to functions related to detecting CPU capabilities for amd64.
* The Illumos Crypto Layer used called into the Illumos kernel's API
* to discover these. They have been converted to instead use the
* 'cpuid' instruction as per the Intel spec. In addition, references to
* the sun4u' and sparc architectures have been removed so that these
* will use the generic implementation.
*
* 7) Removing sha384 and sha512 code: The sha code was actually very
* wasy to port. However, the generic sha384 and sha512 code actually
* exceeds the stack size on arm and powerpc architectures. In an effort
* to remove warnings, this code was removed.
*
* 8) Change large allocations from kmem_alloc() to vmem_alloc(): In
* testing the ICP with the ZFS encryption code, a few allocations were
* found that could potentially be very large. These caused the SPL to
* throw warnings and so they were changed to use vmem_alloc().
*
* 9) Makefiles: Makefiles were added that would work with the existing
* ZFS Makefiles.
*/
void __exit
icp_fini(void)
{
sha2_mod_fini();
sha1_mod_fini();
aes_mod_fini();
kcf_sched_destroy();
kcf_prov_tab_destroy();
kcf_destroy_mech_tabs();
mod_hash_fini();
}
/* roughly equivalent to kcf.c: _init() */
int __init
icp_init(void)
{
/* initialize the mod hash module */
mod_hash_init();
/* initialize the mechanisms tables supported out-of-the-box */
kcf_init_mech_tabs();
/* initialize the providers tables */
kcf_prov_tab_init();
/*
* Initialize scheduling structures. Note that this does NOT
* start any threads since it might not be safe to do so.
*/
kcf_sched_init();
/* initialize algorithms */
aes_mod_init();
sha1_mod_init();
sha2_mod_init();
return (0);
}
#if defined(_KERNEL) && defined(HAVE_SPL)
module_exit(icp_fini);
module_init(icp_init);
MODULE_LICENSE(ZFS_META_LICENSE);
#endif
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