zfs_byteswap.c

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/*
 * 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://www.opensolaris.org/os/licensing.
 * 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 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/zfs_context.h>
#include <sys/vfs.h>
#include <sys/fs/zfs.h>
#include <sys/zfs_znode.h>
#include <sys/zfs_sa.h>
#include <sys/zfs_acl.h>

void
zfs_oldace_byteswap(ace_t *ace, int ace_cnt)
{
        int i;

        for (i = 0; i != ace_cnt; i++, ace++) {
                ace->a_who = BSWAP_32(ace->a_who);
                ace->a_access_mask = BSWAP_32(ace->a_access_mask);
                ace->a_flags = BSWAP_16(ace->a_flags);
                ace->a_type = BSWAP_16(ace->a_type);
        }
}

void
zfs_ace_byteswap(void *buf, size_t size, boolean_t zfs_layout)
{
        caddr_t end;
        caddr_t ptr;
        zfs_ace_t *zacep;
        ace_t *acep;
        uint16_t entry_type;
        size_t entry_size;
        int ace_type;

        end = (caddr_t)buf + size;
        ptr = buf;

        while (ptr < end) {
                if (zfs_layout) {
                        /*
                         * Avoid overrun.  Embedded aces can have one
                         * of several sizes.  We don't know exactly
                         * how many our present, only the size of the
                         * buffer containing them.  That size may be
                         * larger than needed to hold the aces
                         * present.  As long as we do not do any
                         * swapping beyond the end of our block we are
                         * okay.  It it safe to swap any non-ace data
                         * within the block since it is just zeros.
                         */
                        if (ptr + sizeof (zfs_ace_hdr_t) > end) {
                                break;
                        }
                        zacep = (zfs_ace_t *)ptr;
                        zacep->z_hdr.z_access_mask =
                            BSWAP_32(zacep->z_hdr.z_access_mask);
                        zacep->z_hdr.z_flags = BSWAP_16(zacep->z_hdr.z_flags);
                        ace_type = zacep->z_hdr.z_type =
                            BSWAP_16(zacep->z_hdr.z_type);
                        entry_type = zacep->z_hdr.z_flags & ACE_TYPE_FLAGS;
                } else {
                        /* Overrun avoidance */
                        if (ptr + sizeof (ace_t) > end) {
                                break;
                        }
                        acep = (ace_t *)ptr;
                        acep->a_access_mask = BSWAP_32(acep->a_access_mask);
                        acep->a_flags = BSWAP_16(acep->a_flags);
                        ace_type = acep->a_type = BSWAP_16(acep->a_type);
                        acep->a_who = BSWAP_32(acep->a_who);
                        entry_type = acep->a_flags & ACE_TYPE_FLAGS;
                }
                switch (entry_type) {
                case ACE_OWNER:
                case ACE_EVERYONE:
                case (ACE_IDENTIFIER_GROUP | ACE_GROUP):
                        entry_size = zfs_layout ?
                            sizeof (zfs_ace_hdr_t) : sizeof (ace_t);
                        break;
                case ACE_IDENTIFIER_GROUP:
                default:
                        /* Overrun avoidance */
                        if (zfs_layout) {
                                if (ptr + sizeof (zfs_ace_t) <= end) {
                                        zacep->z_fuid = BSWAP_64(zacep->z_fuid);
                                } else {
                                        entry_size = sizeof (zfs_ace_t);
                                        break;
                                }
                        }
                        switch (ace_type) {
                        case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
                        case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
                        case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
                        case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
                                entry_size = zfs_layout ?
                                    sizeof (zfs_object_ace_t) :
                                    sizeof (ace_object_t);
                                break;
                        default:
                                entry_size = zfs_layout ? sizeof (zfs_ace_t) :
                                    sizeof (ace_t);
                                break;
                        }
                }
                ptr = ptr + entry_size;
        }
}

/* ARGSUSED */
void
zfs_oldacl_byteswap(void *buf, size_t size)
{
        int cnt;

        /*
         * Arggh, since we don't know how many ACEs are in
         * the array, we have to swap the entire block
         */

        cnt = size / sizeof (ace_t);

        zfs_oldace_byteswap((ace_t *)buf, cnt);
}

/* ARGSUSED */
void
zfs_acl_byteswap(void *buf, size_t size)
{
        zfs_ace_byteswap(buf, size, B_TRUE);
}

void
zfs_znode_byteswap(void *buf, size_t size)
{
        znode_phys_t *zp = buf;

        ASSERT(size >= sizeof (znode_phys_t));

        zp->zp_crtime[0] = BSWAP_64(zp->zp_crtime[0]);
        zp->zp_crtime[1] = BSWAP_64(zp->zp_crtime[1]);
        zp->zp_atime[0] = BSWAP_64(zp->zp_atime[0]);
        zp->zp_atime[1] = BSWAP_64(zp->zp_atime[1]);
        zp->zp_mtime[0] = BSWAP_64(zp->zp_mtime[0]);
        zp->zp_mtime[1] = BSWAP_64(zp->zp_mtime[1]);
        zp->zp_ctime[0] = BSWAP_64(zp->zp_ctime[0]);
        zp->zp_ctime[1] = BSWAP_64(zp->zp_ctime[1]);
        zp->zp_gen = BSWAP_64(zp->zp_gen);
        zp->zp_mode = BSWAP_64(zp->zp_mode);
        zp->zp_size = BSWAP_64(zp->zp_size);
        zp->zp_parent = BSWAP_64(zp->zp_parent);
        zp->zp_links = BSWAP_64(zp->zp_links);
        zp->zp_xattr = BSWAP_64(zp->zp_xattr);
        zp->zp_rdev = BSWAP_64(zp->zp_rdev);
        zp->zp_flags = BSWAP_64(zp->zp_flags);
        zp->zp_uid = BSWAP_64(zp->zp_uid);
        zp->zp_gid = BSWAP_64(zp->zp_gid);
        zp->zp_zap = BSWAP_64(zp->zp_zap);
        zp->zp_pad[0] = BSWAP_64(zp->zp_pad[0]);
        zp->zp_pad[1] = BSWAP_64(zp->zp_pad[1]);
        zp->zp_pad[2] = BSWAP_64(zp->zp_pad[2]);

        zp->zp_acl.z_acl_extern_obj = BSWAP_64(zp->zp_acl.z_acl_extern_obj);
        zp->zp_acl.z_acl_size = BSWAP_32(zp->zp_acl.z_acl_size);
        zp->zp_acl.z_acl_version = BSWAP_16(zp->zp_acl.z_acl_version);
        zp->zp_acl.z_acl_count = BSWAP_16(zp->zp_acl.z_acl_count);
        if (zp->zp_acl.z_acl_version == ZFS_ACL_VERSION) {
                zfs_acl_byteswap((void *)&zp->zp_acl.z_ace_data[0],
                    ZFS_ACE_SPACE);
        } else {
                zfs_oldace_byteswap((ace_t *)&zp->zp_acl.z_ace_data[0],
                    ACE_SLOT_CNT);
        }
}