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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or https://opensource.org/licenses/CDDL-1.0.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 /*
27 * This file contains the core framework routines for the
28 * kernel cryptographic framework. These routines are at the
29 * layer, between the kernel API/ioctls and the SPI.
30 */
31
32 #include <sys/zfs_context.h>
33 #include <sys/crypto/common.h>
34 #include <sys/crypto/impl.h>
35 #include <sys/crypto/sched_impl.h>
36 #include <sys/crypto/api.h>
37
38 /* kmem caches used by the scheduler */
39 static kmem_cache_t *kcf_context_cache;
40
41 /*
42 * Create a new context.
43 */
44 crypto_ctx_t *
kcf_new_ctx(kcf_provider_desc_t * pd)45 kcf_new_ctx(kcf_provider_desc_t *pd)
46 {
47 crypto_ctx_t *ctx;
48 kcf_context_t *kcf_ctx;
49
50 kcf_ctx = kmem_cache_alloc(kcf_context_cache, KM_SLEEP);
51 if (kcf_ctx == NULL)
52 return (NULL);
53
54 /* initialize the context for the consumer */
55 kcf_ctx->kc_refcnt = 1;
56 KCF_PROV_REFHOLD(pd);
57 kcf_ctx->kc_prov_desc = pd;
58 kcf_ctx->kc_sw_prov_desc = NULL;
59
60 ctx = &kcf_ctx->kc_glbl_ctx;
61 ctx->cc_provider_private = NULL;
62 ctx->cc_framework_private = (void *)kcf_ctx;
63
64 return (ctx);
65 }
66
67 /*
68 * We're done with this framework context, so free it. Note that freeing
69 * framework context (kcf_context) frees the global context (crypto_ctx).
70 *
71 * The provider is responsible for freeing provider private context after a
72 * final or single operation and resetting the cc_provider_private field
73 * to NULL. It should do this before it notifies the framework of the
74 * completion. We still need to call KCF_PROV_FREE_CONTEXT to handle cases
75 * like crypto_cancel_ctx(9f).
76 */
77 void
kcf_free_context(kcf_context_t * kcf_ctx)78 kcf_free_context(kcf_context_t *kcf_ctx)
79 {
80 kcf_provider_desc_t *pd = kcf_ctx->kc_prov_desc;
81 crypto_ctx_t *gctx = &kcf_ctx->kc_glbl_ctx;
82
83 if (gctx->cc_provider_private != NULL) {
84 mutex_enter(&pd->pd_lock);
85 if (!KCF_IS_PROV_REMOVED(pd)) {
86 /*
87 * Increment the provider's internal refcnt so it
88 * doesn't unregister from the framework while
89 * we're calling the entry point.
90 */
91 KCF_PROV_IREFHOLD(pd);
92 mutex_exit(&pd->pd_lock);
93 (void) KCF_PROV_FREE_CONTEXT(pd, gctx);
94 KCF_PROV_IREFRELE(pd);
95 } else {
96 mutex_exit(&pd->pd_lock);
97 }
98 }
99
100 /* kcf_ctx->kc_prov_desc has a hold on pd */
101 KCF_PROV_REFRELE(kcf_ctx->kc_prov_desc);
102
103 kmem_cache_free(kcf_context_cache, kcf_ctx);
104 }
105
106 /*
107 * kmem_cache_alloc constructor for kcf_context structure.
108 */
109 static int
kcf_context_cache_constructor(void * buf,void * cdrarg,int kmflags)110 kcf_context_cache_constructor(void *buf, void *cdrarg, int kmflags)
111 {
112 (void) cdrarg, (void) kmflags;
113 kcf_context_t *kctx = (kcf_context_t *)buf;
114
115 kctx->kc_refcnt = 0;
116
117 return (0);
118 }
119
120 static void
kcf_context_cache_destructor(void * buf,void * cdrarg)121 kcf_context_cache_destructor(void *buf, void *cdrarg)
122 {
123 (void) cdrarg;
124 kcf_context_t *kctx = (kcf_context_t *)buf;
125
126 ASSERT(kctx->kc_refcnt == 0);
127 }
128
129 void
kcf_sched_destroy(void)130 kcf_sched_destroy(void)
131 {
132 if (kcf_context_cache)
133 kmem_cache_destroy(kcf_context_cache);
134 }
135
136 /*
137 * Creates and initializes all the structures needed by the framework.
138 */
139 void
kcf_sched_init(void)140 kcf_sched_init(void)
141 {
142 /*
143 * Create all the kmem caches needed by the framework. We set the
144 * align argument to 64, to get a slab aligned to 64-byte as well as
145 * have the objects (cache_chunksize) to be a 64-byte multiple.
146 * This helps to avoid false sharing as this is the size of the
147 * CPU cache line.
148 */
149 kcf_context_cache = kmem_cache_create("kcf_context_cache",
150 sizeof (struct kcf_context), 64, kcf_context_cache_constructor,
151 kcf_context_cache_destructor, NULL, NULL, NULL, 0);
152 }
153