module/zfs/skein_zfs.c

   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/zio_checksum.h>
  28 #include <sys/skein.h>
  29
  30 #include <sys/abd.h>
  31
  32 static int
  33 skein_incremental(void *buf, size_t size, void *arg)
  34 {
  35         Skein_512_Ctxt_t *ctx = arg;
  36         (void) Skein_512_Update(ctx, buf, size);
  37         return (0);
  38 }
  39 /*
  40  * Computes a native 256-bit skein MAC checksum. Please note that this
  41  * function requires the presence of a ctx_template that should be allocated
  42  * using abd_checksum_skein_tmpl_init.
  43  */
  44 void
  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         memcpy(&ctx, ctx_template, sizeof (ctx));
  52         (void) abd_iterate_func(abd, 0, size, skein_incremental, &ctx);
  53         (void) Skein_512_Final(&ctx, (uint8_t *)zcp);
  54         memset(&ctx, 0, 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
  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 *
  80 abd_checksum_skein_tmpl_init(const zio_cksum_salt_t *salt)
  81 {
  82         Skein_512_Ctxt_t *ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
  83
  84         (void) Skein_512_InitExt(ctx, sizeof (zio_cksum_t) * 8, 0,
  85             salt->zcs_bytes, sizeof (salt->zcs_bytes));
  86         return (ctx);
  87 }
  88
  89 /*
  90  * Frees a skein context template previously allocated using
  91  * zio_checksum_skein_tmpl_init.
  92  */
  93 void
  94 abd_checksum_skein_tmpl_free(void *ctx_template)
  95 {
  96         Skein_512_Ctxt_t *ctx = ctx_template;
  97
  98         memset(ctx, 0, sizeof (*ctx));
  99         kmem_free(ctx, sizeof (*ctx));
 100 }