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 * Copyright 2013 Saso Kiselkov. All rights reserved.
23 * Copyright (c) 2016 by Delphix. All rights reserved.
24 */
25 #include <sys/zfs_context.h>
26 #include <sys/zio.h>
27 #include <sys/skein.h>
28 #include <sys/abd.h>
29
30 static int
skein_incremental(void * buf,size_t size,void * arg)31 skein_incremental(void *buf, size_t size, void *arg)
32 {
33 Skein_512_Ctxt_t *ctx = arg;
34 (void) Skein_512_Update(ctx, buf, size);
35 return (0);
36 }
37
38 /*
39 * Computes a native 256-bit skein MAC checksum. Please note that this
40 * function requires the presence of a ctx_template that should be allocated
41 * using abd_checksum_skein_tmpl_init.
42 */
43 /*ARGSUSED*/
44 void
abd_checksum_skein_native(abd_t * abd,uint64_t size,const void * ctx_template,zio_cksum_t * zcp)45 abd_checksum_skein_native(abd_t *abd, uint64_t size,
46 const void *ctx_template, zio_cksum_t *zcp)
47 {
48 Skein_512_Ctxt_t ctx;
49
50 ASSERT(ctx_template != NULL);
51 bcopy(ctx_template, &ctx, sizeof (ctx));
52 (void) abd_iterate_func(abd, 0, size, skein_incremental, &ctx);
53 (void) Skein_512_Final(&ctx, (uint8_t *)zcp);
54 bzero(&ctx, sizeof (ctx));
55 }
56
57 /*
58 * Byteswapped version of abd_checksum_skein_native. This just invokes
59 * the native checksum function and byteswaps the resulting checksum (since
60 * skein is internally endian-insensitive).
61 */
62 void
abd_checksum_skein_byteswap(abd_t * abd,uint64_t size,const void * ctx_template,zio_cksum_t * zcp)63 abd_checksum_skein_byteswap(abd_t *abd, uint64_t size,
64 const void *ctx_template, zio_cksum_t *zcp)
65 {
66 zio_cksum_t tmp;
67
68 abd_checksum_skein_native(abd, size, ctx_template, &tmp);
69 zcp->zc_word[0] = BSWAP_64(tmp.zc_word[0]);
70 zcp->zc_word[1] = BSWAP_64(tmp.zc_word[1]);
71 zcp->zc_word[2] = BSWAP_64(tmp.zc_word[2]);
72 zcp->zc_word[3] = BSWAP_64(tmp.zc_word[3]);
73 }
74
75 /*
76 * Allocates a skein MAC template suitable for using in skein MAC checksum
77 * computations and returns a pointer to it.
78 */
79 void *
abd_checksum_skein_tmpl_init(const zio_cksum_salt_t * salt)80 abd_checksum_skein_tmpl_init(const zio_cksum_salt_t *salt)
81 {
82 Skein_512_Ctxt_t *ctx;
83
84 ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
85 (void) Skein_512_InitExt(ctx, sizeof (zio_cksum_t) * 8, 0,
86 salt->zcs_bytes, sizeof (salt->zcs_bytes));
87 return (ctx);
88 }
89
90 /*
91 * Frees a skein context template previously allocated using
92 * abd_checksum_skein_tmpl_init.
93 */
94 void
abd_checksum_skein_tmpl_free(void * ctx_template)95 abd_checksum_skein_tmpl_free(void *ctx_template)
96 {
97 Skein_512_Ctxt_t *ctx = ctx_template;
98
99 bzero(ctx, sizeof (*ctx));
100 kmem_free(ctx, sizeof (*ctx));
101 }
102