module/icp/illumos-crypto.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2017, Datto, Inc. All rights reserved.
  24  */
  25
  26 #ifdef _KERNEL
  27 #include <linux/module.h>
  28 #include <linux/kernel.h>
  29 #include <linux/init.h>
  30 #else
  31 #define __exit
  32 #define __init
  33 #endif
  34
  35 #include <sys/crypto/common.h>
  36 #include <sys/crypto/api.h>
  37 #include <sys/crypto/impl.h>
  38 #include <sys/crypto/sched_impl.h>
  39 #include <sys/modhash_impl.h>
  40 #include <sys/crypto/icp.h>
  41
  42 /*
  43  * Changes made to the original Illumos Crypto Layer for the ICP:
  44  *
  45  * Several changes were needed to allow the Illumos Crypto Layer
  46  * to work in the Linux kernel. Almost all of the changes fall into
  47  * one of the following categories:
  48  *
  49  * 1) Moving the syntax to the C90: This was mostly a matter of
  50  * changing func() definitions to func(void). In a few cases,
  51  * initializations of structs with unions needed to have brackets
  52  * added.
  53  *
  54  * 2) Changes to allow userspace compilation: The ICP is meant to be
  55  * compiled and used in both userspace and kernel space (for ztest and
  56  * libzfs), so the _KERNEL macros did not make sense anymore. For the
  57  * same reason, many header includes were also changed to use
  58  * sys/zfs_context.h
  59  *
  60  * 3) Moving to a statically compiled architecture: At some point in
  61  * the future it may make sense to have encryption algorithms that are
  62  * loadable into the ICP at runtime via separate kernel modules.
  63  * However, considering that this code will probably not see much use
  64  * outside of zfs and zfs encryption only requires aes and sha256
  65  * algorithms it seemed like more trouble than it was worth to port over
  66  * Illumos's kernel module structure to a Linux kernel module. In
  67  * addition, The Illumos code related to keeping track of kernel modules
  68  * is very much tied to the Illumos OS and proved difficult to port to
  69  * Linux. Therefore, the structure of the ICP was simplified to work
  70  * statically and several pieces of code responsible for keeping track
  71  * of Illumos kernel modules were removed and simplified. All module
  72  * initialization and destruction is now called in this file during
  73  * Linux kernel module loading and unloading.
  74  *
  75  * 4) Adding destructors: The Illumos Crypto Layer is built into
  76  * the Illumos kernel and is not meant to be unloaded. Some destructors
  77  * were added to allow the ICP to be unloaded without leaking
  78  * structures.
  79  *
  80  * 5) Removing CRYPTO_DATA_MBLK related structures and code:
  81  * crypto_data_t can have 3 formats, CRYPTO_DATA_RAW, CRYPTO_DATA_UIO,
  82  * and CRYPTO_DATA_MBLK. ZFS only requires the first 2 formats, as the
  83  * last one is related to streamed data. To simplify the port, code
  84  * related to this format was removed.
  85  *
  86  * 6) Changes for architecture specific code: Some changes were needed
  87  * to make architecture specific assembly compile. The biggest change
  88  * here was to functions related to detecting CPU capabilities for amd64.
  89  * The Illumos Crypto Layer used called into the Illumos kernel's API
  90  * to discover these. They have been converted to instead use the
  91  * 'cpuid' instruction as per the Intel spec. In addition, references to
  92  * the sun4u' and sparc architectures have been removed so that these
  93  * will use the generic implementation.
  94  *
  95  * 7) Removing sha384 and sha512 code: The sha code was actually very
  96  * wasy to port. However, the generic sha384 and sha512 code actually
  97  * exceeds the stack size on arm and powerpc architectures. In an effort
  98  * to remove warnings, this code was removed.
  99  *
 100  * 8) Change large allocations from kmem_alloc() to vmem_alloc(): In
 101  * testing the ICP with the ZFS encryption code, a few allocations were
 102  * found that could potentially be very large. These caused the SPL to
 103  * throw warnings and so they were changed to use vmem_alloc().
 104  *
 105  * 9) Makefiles: Makefiles were added that would work with the existing
 106  * ZFS Makefiles.
 107  */
 108
 109 void __exit
 110 icp_fini(void)
 111 {
 112         skein_mod_fini();
 113         sha2_mod_fini();
 114         sha1_mod_fini();
 115         edonr_mod_fini();
 116         aes_mod_fini();
 117         kcf_sched_destroy();
 118         kcf_prov_tab_destroy();
 119         kcf_destroy_mech_tabs();
 120         mod_hash_fini();
 121 }
 122
 123 /* roughly equivalent to kcf.c: _init() */
 124 int __init
 125 icp_init(void)
 126 {
 127         /* initialize the mod hash module */
 128         mod_hash_init();
 129
 130         /* initialize the mechanisms tables supported out-of-the-box */
 131         kcf_init_mech_tabs();
 132
 133         /* initialize the providers tables */
 134         kcf_prov_tab_init();
 135
 136         /*
 137          * Initialize scheduling structures. Note that this does NOT
 138          * start any threads since it might not be safe to do so.
 139          */
 140         kcf_sched_init();
 141
 142         /* initialize algorithms */
 143         aes_mod_init();
 144         edonr_mod_init();
 145         sha1_mod_init();
 146         sha2_mod_init();
 147         skein_mod_init();
 148
 149         return (0);
 150 }
 151
 152 #if defined(_KERNEL)
 153 module_exit(icp_fini);
 154 module_init(icp_init);
 155 MODULE_AUTHOR(ZFS_META_AUTHOR);
 156 MODULE_LICENSE(ZFS_META_LICENSE);
 157 MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE);
 158 #endif