1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3 * CDDL HEADER START
4 *
5 * The contents of this file are subject to the terms of the
6 * Common Development and Distribution License (the "License").
7 * You may not use this file except in compliance with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://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 /*
24 * Copyright 2022 Tino Reichardt <milky-zfs@mcmilk.de>
25 */
26
27 #include <sys/zfs_context.h>
28 #include <sys/zio_checksum.h>
29 #include <sys/blake3.h>
30 #include <sys/abd.h>
31
32 static int
blake3_incremental(void * buf,size_t size,void * arg)33 blake3_incremental(void *buf, size_t size, void *arg)
34 {
35 BLAKE3_CTX *ctx = arg;
36
37 Blake3_Update(ctx, buf, size);
38
39 return (0);
40 }
41
42 /*
43 * Computes a native 256-bit BLAKE3 MAC checksum. Please note that this
44 * function requires the presence of a ctx_template that should be allocated
45 * using abd_checksum_blake3_tmpl_init.
46 */
47 void
abd_checksum_blake3_native(abd_t * abd,uint64_t size,const void * ctx_template,zio_cksum_t * zcp)48 abd_checksum_blake3_native(abd_t *abd, uint64_t size, const void *ctx_template,
49 zio_cksum_t *zcp)
50 {
51 ASSERT(ctx_template != NULL);
52
53 #if defined(_KERNEL)
54 kpreempt_disable();
55 BLAKE3_CTX *ctx = blake3_per_cpu_ctx[CPU_SEQID];
56 #else
57 BLAKE3_CTX *ctx = kmem_alloc(sizeof (*ctx), KM_SLEEP);
58 #endif
59
60 memcpy(ctx, ctx_template, sizeof (*ctx));
61 (void) abd_iterate_func(abd, 0, size, blake3_incremental, ctx);
62 Blake3_Final(ctx, (uint8_t *)zcp);
63
64 #if defined(_KERNEL)
65 kpreempt_enable();
66 #else
67 memset(ctx, 0, sizeof (*ctx));
68 kmem_free(ctx, sizeof (*ctx));
69 #endif
70 }
71
72 /*
73 * Byteswapped version of abd_checksum_blake3_native. This just invokes
74 * the native checksum function and byteswaps the resulting checksum (since
75 * BLAKE3 is internally endian-insensitive).
76 */
77 void
abd_checksum_blake3_byteswap(abd_t * abd,uint64_t size,const void * ctx_template,zio_cksum_t * zcp)78 abd_checksum_blake3_byteswap(abd_t *abd, uint64_t size,
79 const void *ctx_template, zio_cksum_t *zcp)
80 {
81 zio_cksum_t tmp;
82
83 ASSERT(ctx_template != NULL);
84
85 abd_checksum_blake3_native(abd, size, ctx_template, &tmp);
86 zcp->zc_word[0] = BSWAP_64(tmp.zc_word[0]);
87 zcp->zc_word[1] = BSWAP_64(tmp.zc_word[1]);
88 zcp->zc_word[2] = BSWAP_64(tmp.zc_word[2]);
89 zcp->zc_word[3] = BSWAP_64(tmp.zc_word[3]);
90 }
91
92 /*
93 * Allocates a BLAKE3 MAC template suitable for using in BLAKE3 MAC checksum
94 * computations and returns a pointer to it.
95 */
96 void *
abd_checksum_blake3_tmpl_init(const zio_cksum_salt_t * salt)97 abd_checksum_blake3_tmpl_init(const zio_cksum_salt_t *salt)
98 {
99 BLAKE3_CTX *ctx;
100
101 ASSERT(sizeof (salt->zcs_bytes) == 32);
102
103 /* init reference object */
104 ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
105 Blake3_InitKeyed(ctx, salt->zcs_bytes);
106
107 return (ctx);
108 }
109
110 /*
111 * Frees a BLAKE3 context template previously allocated using
112 * zio_checksum_blake3_tmpl_init.
113 */
114 void
abd_checksum_blake3_tmpl_free(void * ctx_template)115 abd_checksum_blake3_tmpl_free(void *ctx_template)
116 {
117 BLAKE3_CTX *ctx = ctx_template;
118
119 memset(ctx, 0, sizeof (*ctx));
120 kmem_free(ctx, sizeof (*ctx));
121 }
122