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 http://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 /*
23 * Copyright 2022 Tino Reichardt <milky-zfs@mcmilk.de>
24 */
25
26 #include <sys/zfs_context.h>
27 #include <sys/zio_checksum.h>
28 #include <sys/blake3.h>
29 #include <sys/abd.h>
30
31 static int
blake3_incremental(void * buf,size_t size,void * arg)32 blake3_incremental(void *buf, size_t size, void *arg)
33 {
34 BLAKE3_CTX *ctx = arg;
35
36 Blake3_Update(ctx, buf, size);
37
38 return (0);
39 }
40
41 /*
42 * Computes a native 256-bit BLAKE3 MAC checksum. Please note that this
43 * function requires the presence of a ctx_template that should be allocated
44 * using abd_checksum_blake3_tmpl_init.
45 */
46 void
abd_checksum_blake3_native(abd_t * abd,uint64_t size,const void * ctx_template,zio_cksum_t * zcp)47 abd_checksum_blake3_native(abd_t *abd, uint64_t size, const void *ctx_template,
48 zio_cksum_t *zcp)
49 {
50 ASSERT(ctx_template != NULL);
51
52 #if defined(_KERNEL)
53 kpreempt_disable();
54 BLAKE3_CTX *ctx = blake3_per_cpu_ctx[CPU_SEQID];
55 #else
56 BLAKE3_CTX *ctx = kmem_alloc(sizeof (*ctx), KM_SLEEP);
57 #endif
58
59 memcpy(ctx, ctx_template, sizeof (*ctx));
60 (void) abd_iterate_func(abd, 0, size, blake3_incremental, ctx);
61 Blake3_Final(ctx, (uint8_t *)zcp);
62
63 #if defined(_KERNEL)
64 kpreempt_enable();
65 #else
66 memset(ctx, 0, sizeof (*ctx));
67 kmem_free(ctx, sizeof (*ctx));
68 #endif
69 }
70
71 /*
72 * Byteswapped version of abd_checksum_blake3_native. This just invokes
73 * the native checksum function and byteswaps the resulting checksum (since
74 * BLAKE3 is internally endian-insensitive).
75 */
76 void
abd_checksum_blake3_byteswap(abd_t * abd,uint64_t size,const void * ctx_template,zio_cksum_t * zcp)77 abd_checksum_blake3_byteswap(abd_t *abd, uint64_t size,
78 const void *ctx_template, zio_cksum_t *zcp)
79 {
80 zio_cksum_t tmp;
81
82 ASSERT(ctx_template != NULL);
83
84 abd_checksum_blake3_native(abd, size, ctx_template, &tmp);
85 zcp->zc_word[0] = BSWAP_64(tmp.zc_word[0]);
86 zcp->zc_word[1] = BSWAP_64(tmp.zc_word[1]);
87 zcp->zc_word[2] = BSWAP_64(tmp.zc_word[2]);
88 zcp->zc_word[3] = BSWAP_64(tmp.zc_word[3]);
89 }
90
91 /*
92 * Allocates a BLAKE3 MAC template suitable for using in BLAKE3 MAC checksum
93 * computations and returns a pointer to it.
94 */
95 void *
abd_checksum_blake3_tmpl_init(const zio_cksum_salt_t * salt)96 abd_checksum_blake3_tmpl_init(const zio_cksum_salt_t *salt)
97 {
98 BLAKE3_CTX *ctx;
99
100 ASSERT(sizeof (salt->zcs_bytes) == 32);
101
102 /* init reference object */
103 ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
104 Blake3_InitKeyed(ctx, salt->zcs_bytes);
105
106 return (ctx);
107 }
108
109 /*
110 * Frees a BLAKE3 context template previously allocated using
111 * zio_checksum_blake3_tmpl_init.
112 */
113 void
abd_checksum_blake3_tmpl_free(void * ctx_template)114 abd_checksum_blake3_tmpl_free(void *ctx_template)
115 {
116 BLAKE3_CTX *ctx = ctx_template;
117
118 memset(ctx, 0, sizeof (*ctx));
119 kmem_free(ctx, sizeof (*ctx));
120 }
121