FreeBSD/Linux Kernel Cross Reference
sys/contrib/openzfs/module/zfs/skein_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 2013 Saso Kiselkov.  All rights reserved.
     * Copyright (c) 2016 by Delphix. All rights reserved.
     */
    #include <sys/zfs_context.h>
    #include <sys/zio.h>
    #include <sys/zio_checksum.h>
    #include <sys/skein.h>
    
    #include <sys/abd.h>
    
    static int
    skein_incremental(void *buf, size_t size, void *arg)
    {
            Skein_512_Ctxt_t *ctx = arg;
            (void) Skein_512_Update(ctx, buf, size);
            return (0);
    }
    /*
     * Computes a native 256-bit skein MAC checksum. Please note that this
     * function requires the presence of a ctx_template that should be allocated
     * using abd_checksum_skein_tmpl_init.
     */
    void
    abd_checksum_skein_native(abd_t *abd, uint64_t size,
        const void *ctx_template, zio_cksum_t *zcp)
    {
            Skein_512_Ctxt_t ctx;
    
            ASSERT(ctx_template != NULL);
            memcpy(&ctx, ctx_template, sizeof (ctx));
            (void) abd_iterate_func(abd, 0, size, skein_incremental, &ctx);
            (void) Skein_512_Final(&ctx, (uint8_t *)zcp);
            memset(&ctx, 0, sizeof (ctx));
    }
    
    /*
     * Byteswapped version of abd_checksum_skein_native. This just invokes
     * the native checksum function and byteswaps the resulting checksum (since
     * skein is internally endian-insensitive).
     */
    void
    abd_checksum_skein_byteswap(abd_t *abd, uint64_t size,
        const void *ctx_template, zio_cksum_t *zcp)
    {
            zio_cksum_t     tmp;
    
            abd_checksum_skein_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 skein MAC template suitable for using in skein MAC checksum
     * computations and returns a pointer to it.
     */
    void *
    abd_checksum_skein_tmpl_init(const zio_cksum_salt_t *salt)
    {
            Skein_512_Ctxt_t *ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
    
            (void) Skein_512_InitExt(ctx, sizeof (zio_cksum_t) * 8, 0,
                salt->zcs_bytes, sizeof (salt->zcs_bytes));
            return (ctx);
    }
    
    /*
     * Frees a skein context template previously allocated using
     * zio_checksum_skein_tmpl_init.
     */
    void
    abd_checksum_skein_tmpl_free(void *ctx_template)
    {
            Skein_512_Ctxt_t *ctx = ctx_template;
    
            memset(ctx, 0, sizeof (*ctx));
            kmem_free(ctx, sizeof (*ctx));
   }

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