/*-
 * Copyright (c) 2008, 2009 Edward Tomasz Napierała <trasz@FreeBSD.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/malloc.h>
#include <sys/errno.h>
#include <sys/zfs_acl.h>
#include <sys/acl.h>

struct zfs2bsd {
        uint32_t        zb_zfs;
        int             zb_bsd;
};

struct zfs2bsd perms[] = {{ACE_READ_DATA, ACL_READ_DATA},
                        {ACE_WRITE_DATA, ACL_WRITE_DATA},
                        {ACE_EXECUTE, ACL_EXECUTE},
                        {ACE_APPEND_DATA, ACL_APPEND_DATA},
                        {ACE_DELETE_CHILD, ACL_DELETE_CHILD},
                        {ACE_DELETE, ACL_DELETE},
                        {ACE_READ_ATTRIBUTES, ACL_READ_ATTRIBUTES},
                        {ACE_WRITE_ATTRIBUTES, ACL_WRITE_ATTRIBUTES},
                        {ACE_READ_NAMED_ATTRS, ACL_READ_NAMED_ATTRS},
                        {ACE_WRITE_NAMED_ATTRS, ACL_WRITE_NAMED_ATTRS},
                        {ACE_READ_ACL, ACL_READ_ACL},
                        {ACE_WRITE_ACL, ACL_WRITE_ACL},
                        {ACE_WRITE_OWNER, ACL_WRITE_OWNER},
                        {ACE_SYNCHRONIZE, ACL_SYNCHRONIZE},
                        {0, 0}};

struct zfs2bsd flags[] = {{ACE_FILE_INHERIT_ACE,
                            ACL_ENTRY_FILE_INHERIT},
                        {ACE_DIRECTORY_INHERIT_ACE,
                            ACL_ENTRY_DIRECTORY_INHERIT},
                        {ACE_NO_PROPAGATE_INHERIT_ACE,
                            ACL_ENTRY_NO_PROPAGATE_INHERIT},
                        {ACE_INHERIT_ONLY_ACE,
                            ACL_ENTRY_INHERIT_ONLY},
                        {ACE_INHERITED_ACE,
                            ACL_ENTRY_INHERITED},
                        {ACE_SUCCESSFUL_ACCESS_ACE_FLAG,
                            ACL_ENTRY_SUCCESSFUL_ACCESS},
                        {ACE_FAILED_ACCESS_ACE_FLAG,
                            ACL_ENTRY_FAILED_ACCESS},
                        {0, 0}};

static int
_bsd_from_zfs(uint32_t zfs, const struct zfs2bsd *table)
{
        const struct zfs2bsd *tmp;
        int bsd = 0;

        for (tmp = table; tmp->zb_zfs != 0; tmp++) {
                if (zfs & tmp->zb_zfs)
                        bsd |= tmp->zb_bsd;
        }

        return (bsd);
}

static uint32_t
_zfs_from_bsd(int bsd, const struct zfs2bsd *table)
{
        const struct zfs2bsd *tmp;
        uint32_t zfs = 0;

        for (tmp = table; tmp->zb_bsd != 0; tmp++) {
                if (bsd & tmp->zb_bsd)
                        zfs |= tmp->zb_zfs;
        }

        return (zfs);
}

int
acl_from_aces(struct acl *aclp, const ace_t *aces, int nentries)
{
        int i;
        struct acl_entry *entry;
        const ace_t *ace;

        if (nentries < 1) {
                printf("acl_from_aces: empty ZFS ACL; returning EINVAL.\n");
                return (EINVAL);
        }

        if (nentries > ACL_MAX_ENTRIES) {
                /*
                 * I believe it may happen only when moving a pool
                 * from SunOS to FreeBSD.
                 */
                printf("acl_from_aces: ZFS ACL too big to fit "
                    "into 'struct acl'; returning EINVAL.\n");
                return (EINVAL);
        }

        bzero(aclp, sizeof(*aclp));
        aclp->acl_maxcnt = ACL_MAX_ENTRIES;
        aclp->acl_cnt = nentries;

        for (i = 0; i < nentries; i++) {
                entry = &(aclp->acl_entry[i]);
                ace = &(aces[i]);

                if (ace->a_flags & ACE_OWNER)
                        entry->ae_tag = ACL_USER_OBJ;
                else if (ace->a_flags & ACE_GROUP)
                        entry->ae_tag = ACL_GROUP_OBJ;
                else if (ace->a_flags & ACE_EVERYONE)
                        entry->ae_tag = ACL_EVERYONE;
                else if (ace->a_flags & ACE_IDENTIFIER_GROUP)
                        entry->ae_tag = ACL_GROUP;
                else
                        entry->ae_tag = ACL_USER;

                if (entry->ae_tag == ACL_USER || entry->ae_tag == ACL_GROUP)
                        entry->ae_id = ace->a_who;
                else
                        entry->ae_id = ACL_UNDEFINED_ID;

                entry->ae_perm = _bsd_from_zfs(ace->a_access_mask, perms);
                entry->ae_flags = _bsd_from_zfs(ace->a_flags, flags);

                switch (ace->a_type) {
                case ACE_ACCESS_ALLOWED_ACE_TYPE:
                        entry->ae_entry_type = ACL_ENTRY_TYPE_ALLOW;
                        break;
                case ACE_ACCESS_DENIED_ACE_TYPE:
                        entry->ae_entry_type = ACL_ENTRY_TYPE_DENY;
                        break;
                case ACE_SYSTEM_AUDIT_ACE_TYPE:
                        entry->ae_entry_type = ACL_ENTRY_TYPE_AUDIT;
                        break;
                case ACE_SYSTEM_ALARM_ACE_TYPE:
                        entry->ae_entry_type = ACL_ENTRY_TYPE_ALARM;
                        break;
                default:
                        panic("acl_from_aces: a_type is 0x%x", ace->a_type);
                }
        }

        return (0);
}

void
aces_from_acl(ace_t *aces, int *nentries, const struct acl *aclp)
{
        int i;
        const struct acl_entry *entry;
        ace_t *ace;

        bzero(aces, sizeof(*aces) * aclp->acl_cnt);

        *nentries = aclp->acl_cnt;

        for (i = 0; i < aclp->acl_cnt; i++) {
                entry = &(aclp->acl_entry[i]);
                ace = &(aces[i]);

                ace->a_who = entry->ae_id;

                if (entry->ae_tag == ACL_USER_OBJ)
                        ace->a_flags = ACE_OWNER;
                else if (entry->ae_tag == ACL_GROUP_OBJ)
                        ace->a_flags = (ACE_GROUP | ACE_IDENTIFIER_GROUP);
                else if (entry->ae_tag == ACL_GROUP)
                        ace->a_flags = ACE_IDENTIFIER_GROUP;
                else if (entry->ae_tag == ACL_EVERYONE)
                        ace->a_flags = ACE_EVERYONE;
                else /* ACL_USER */
                        ace->a_flags = 0;

                ace->a_access_mask = _zfs_from_bsd(entry->ae_perm, perms);
                ace->a_flags |= _zfs_from_bsd(entry->ae_flags, flags);

                switch (entry->ae_entry_type) {
                case ACL_ENTRY_TYPE_ALLOW:
                        ace->a_type = ACE_ACCESS_ALLOWED_ACE_TYPE;
                        break;
                case ACL_ENTRY_TYPE_DENY:
                        ace->a_type = ACE_ACCESS_DENIED_ACE_TYPE;
                        break;
                case ACL_ENTRY_TYPE_ALARM:
                        ace->a_type = ACE_SYSTEM_ALARM_ACE_TYPE;
                        break;
                case ACL_ENTRY_TYPE_AUDIT:
                        ace->a_type = ACE_SYSTEM_AUDIT_ACE_TYPE;
                        break;
                default:
                        panic("aces_from_acl: ae_entry_type is 0x%x", entry->ae_entry_type);
                }
        }
}