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 https://opensource.org/licenses/CDDL-1.0.
  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/crypto/icp.h>
  40
  41 /*
  42  * Changes made to the original Illumos Crypto Layer for the ICP:
  43  *
  44  * Several changes were needed to allow the Illumos Crypto Layer
  45  * to work in the Linux kernel. Almost all of the changes fall into
  46  * one of the following categories:
  47  *
  48  * 1) Moving the syntax to the C90: This was mostly a matter of
  49  * changing func() definitions to func(void). In a few cases,
  50  * initializations of structs with unions needed to have brackets
  51  * added.
  52  *
  53  * 2) Changes to allow userspace compilation: The ICP is meant to be
  54  * compiled and used in both userspace and kernel space (for ztest and
  55  * libzfs), so the _KERNEL macros did not make sense anymore. For the
  56  * same reason, many header includes were also changed to use
  57  * sys/zfs_context.h
  58  *
  59  * 3) Moving to a statically compiled architecture: At some point in
  60  * the future it may make sense to have encryption algorithms that are
  61  * loadable into the ICP at runtime via separate kernel modules.
  62  * However, considering that this code will probably not see much use
  63  * outside of zfs and zfs encryption only requires a select few
  64  * algorithms it seemed like more trouble than it was worth to port over
  65  * Illumos's kernel module structure to a Linux kernel module. In
  66  * addition, The Illumos code related to keeping track of kernel modules
  67  * is very much tied to the Illumos OS and proved difficult to port.
  68  * Therefore, the structure of the ICP was simplified to work
  69  * statically and all the Illumos kernel module loading subsystem was removed.
  70  * All module initialization and destruction is now called in this file
  71  * during kernel module loading and unloading.
  72  *
  73  * 4) Adding destructors: The Illumos Crypto Layer is built into
  74  * the Illumos kernel and is not meant to be unloaded. Some destructors
  75  * were added to allow the ICP to be unloaded without leaking
  76  * structures.
  77  *
  78  * 5) Removing CRYPTO_DATA_MBLK related structures and code:
  79  * crypto_data_t can have 3 formats, CRYPTO_DATA_RAW, CRYPTO_DATA_UIO,
  80  * and CRYPTO_DATA_MBLK. ZFS only requires the first 2 formats, as the
  81  * last one is related to streamed data. To simplify the port, code
  82  * related to this format was removed.
  83  *
  84  * 6) Changes for architecture specific code: Some changes were needed
  85  * to make architecture specific assembly compile. The biggest change
  86  * here was to functions related to detecting CPU capabilities for amd64.
  87  * The Illumos Crypto Layer used called into the Illumos kernel's API
  88  * to discover these. They have been converted to instead use the
  89  * 'cpuid' instruction as per the Intel spec. In addition, references to
  90  * the sun4u' and sparc architectures have been removed so that these
  91  * will use the generic implementation.
  92  *
  93  * 7) Removing sha384 and sha512 code: The sha code was actually very
  94  * easy to port. However, the generic sha384 and sha512 code actually
  95  * exceeds the stack size on arm and powerpc architectures. In an effort
  96  * to remove warnings, this code was removed.
  97  *
  98  * 8) Change large allocations from kmem_alloc() to vmem_alloc(): In
  99  * testing the ICP with the ZFS encryption code, a few allocations were
 100  * found that could potentially be very large. These caused the SPL to
 101  * throw warnings and so they were changed to use vmem_alloc().
 102  *
 103  * 9) Makefiles: Makefiles were added that would work with the existing
 104  * ZFS Makefiles.
 105  */
 106
 107 void
 108 icp_fini(void)
 109 {
 110         sha2_mod_fini();
 111         aes_mod_fini();
 112         kcf_sched_destroy();
 113         kcf_prov_tab_destroy();
 114         kcf_destroy_mech_tabs();
 115 }
 116
 117 /* roughly equivalent to kcf.c: _init() */
 118 int __init
 119 icp_init(void)
 120 {
 121         /* initialize the mechanisms tables supported out-of-the-box */
 122         kcf_init_mech_tabs();
 123
 124         /* initialize the providers tables */
 125         kcf_prov_tab_init();
 126
 127         /*
 128          * Initialize scheduling structures. Note that this does NOT
 129          * start any threads since it might not be safe to do so.
 130          */
 131         kcf_sched_init();
 132
 133         /* initialize algorithms */
 134         aes_mod_init();
 135         sha2_mod_init();
 136
 137         return (0);
 138 }