xref: /freebsd/sys/contrib/openzfs/module/icp/illumos-crypto.c (revision ebacd8013fe5f7fdf9f6a5b286f6680dd2891036)
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 	skein_mod_fini();
111 	sha2_mod_fini();
112 	aes_mod_fini();
113 	kcf_sched_destroy();
114 	kcf_prov_tab_destroy();
115 	kcf_destroy_mech_tabs();
116 }
117 
118 /* roughly equivalent to kcf.c: _init() */
119 int __init
120 icp_init(void)
121 {
122 	/* initialize the mechanisms tables supported out-of-the-box */
123 	kcf_init_mech_tabs();
124 
125 	/* initialize the providers tables */
126 	kcf_prov_tab_init();
127 
128 	/*
129 	 * Initialize scheduling structures. Note that this does NOT
130 	 * start any threads since it might not be safe to do so.
131 	 */
132 	kcf_sched_init();
133 
134 	/* initialize algorithms */
135 	aes_mod_init();
136 	sha2_mod_init();
137 	skein_mod_init();
138 
139 	return (0);
140 }
141 
142 #if defined(_KERNEL) && defined(__FreeBSD__)
143 module_exit(icp_fini);
144 module_init(icp_init);
145 #endif
146