FreeBSD/Linux Kernel Cross Reference
sys/contrib/openzfs/module/zfs/blake3_zfs.c

     /*
      * CDDL HEADER START
      *
      * The contents of this file are subject to the terms of the
      * Common Development and Distribution License (the "License").
      * You may not use this file except in compliance with the License.
      *
      * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      * or http://opensource.org/licenses/CDDL-1.0.
     * See the License for the specific language governing permissions
     * and limitations under the License.
     *
     * When distributing Covered Code, include this CDDL HEADER in each
     * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     * If applicable, add the following below this CDDL HEADER, with the
     * fields enclosed by brackets "[]" replaced with your own identifying
     * information: Portions Copyright [yyyy] [name of copyright owner]
     *
     * CDDL HEADER END
     */
    
    /*
     * Copyright 2022 Tino Reichardt <milky-zfs@mcmilk.de>
     */
    
    #include <sys/zfs_context.h>
    #include <sys/zio_checksum.h>
    #include <sys/blake3.h>
    #include <sys/abd.h>
    
    static int
    blake3_incremental(void *buf, size_t size, void *arg)
    {
            BLAKE3_CTX *ctx = arg;
    
            Blake3_Update(ctx, buf, size);
    
            return (0);
    }
    
    /*
     * Computes a native 256-bit BLAKE3 MAC checksum. Please note that this
     * function requires the presence of a ctx_template that should be allocated
     * using abd_checksum_blake3_tmpl_init.
     */
    void
    abd_checksum_blake3_native(abd_t *abd, uint64_t size, const void *ctx_template,
        zio_cksum_t *zcp)
    {
            ASSERT(ctx_template != NULL);
    
    #if defined(_KERNEL)
            BLAKE3_CTX *ctx = blake3_per_cpu_ctx[CPU_SEQID_UNSTABLE];
    #else
            BLAKE3_CTX *ctx = kmem_alloc(sizeof (*ctx), KM_SLEEP);
    #endif
    
            memcpy(ctx, ctx_template, sizeof (*ctx));
            (void) abd_iterate_func(abd, 0, size, blake3_incremental, ctx);
            Blake3_Final(ctx, (uint8_t *)zcp);
    
    #if !defined(_KERNEL)
            memset(ctx, 0, sizeof (*ctx));
            kmem_free(ctx, sizeof (*ctx));
    #endif
    }
    
    /*
     * Byteswapped version of abd_checksum_blake3_native. This just invokes
     * the native checksum function and byteswaps the resulting checksum (since
     * BLAKE3 is internally endian-insensitive).
     */
    void
    abd_checksum_blake3_byteswap(abd_t *abd, uint64_t size,
        const void *ctx_template, zio_cksum_t *zcp)
    {
            zio_cksum_t tmp;
    
            ASSERT(ctx_template != NULL);
    
            abd_checksum_blake3_native(abd, size, ctx_template, &tmp);
            zcp->zc_word[0] = BSWAP_64(tmp.zc_word[0]);
            zcp->zc_word[1] = BSWAP_64(tmp.zc_word[1]);
            zcp->zc_word[2] = BSWAP_64(tmp.zc_word[2]);
            zcp->zc_word[3] = BSWAP_64(tmp.zc_word[3]);
    }
    
    /*
     * Allocates a BLAKE3 MAC template suitable for using in BLAKE3 MAC checksum
     * computations and returns a pointer to it.
     */
    void *
    abd_checksum_blake3_tmpl_init(const zio_cksum_salt_t *salt)
    {
            BLAKE3_CTX *ctx;
    
            ASSERT(sizeof (salt->zcs_bytes) == 32);
    
            /* init reference object */
           ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
           Blake3_InitKeyed(ctx, salt->zcs_bytes);
   
           return (ctx);
   }
   
   /*
    * Frees a BLAKE3 context template previously allocated using
    * zio_checksum_blake3_tmpl_init.
    */
   void
   abd_checksum_blake3_tmpl_free(void *ctx_template)
   {
           BLAKE3_CTX *ctx = ctx_template;
   
           memset(ctx, 0, sizeof (*ctx));
           kmem_free(ctx, sizeof (*ctx));
   }

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