module/zfs/blake3_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 /*
  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
  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
  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
  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 *
  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
 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 }