/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1999-2006 Robert N. M. Watson
* All rights reserved.
*
* This software was developed by Robert Watson for the TrustedBSD Project.
*
* 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.
*/
/*
* Developed by the TrustedBSD Project.
*
* ACL support routines specific to POSIX.1e access control lists. These are
* utility routines for code common across file systems implementing POSIX.1e
* ACLs.
*/
/*
* For the purposes of filesystems maintaining the _OBJ entries in an inode
* with a mode_t field, this routine converts a mode_t entry to an
* acl_perm_t.
*/
acl_perm_t
acl_posix1e_mode_to_perm(acl_tag_t tag, mode_t mode)
{
acl_perm_t perm = 0;
switch(tag) {
case ACL_USER_OBJ:
if (mode & S_IXUSR)
perm |= ACL_EXECUTE;
if (mode & S_IRUSR)
perm |= ACL_READ;
if (mode & S_IWUSR)
perm |= ACL_WRITE;
return (perm);
case ACL_GROUP_OBJ:
if (mode & S_IXGRP)
perm |= ACL_EXECUTE;
if (mode & S_IRGRP)
perm |= ACL_READ;
if (mode & S_IWGRP)
perm |= ACL_WRITE;
return (perm);
case ACL_OTHER:
if (mode & S_IXOTH)
perm |= ACL_EXECUTE;
if (mode & S_IROTH)
perm |= ACL_READ;
if (mode & S_IWOTH)
perm |= ACL_WRITE;
return (perm);
case ACL_OTHER:
acl_entry.ae_id = ACL_UNDEFINED_ID;
break;
default:
acl_entry.ae_id = ACL_UNDEFINED_ID;
printf("acl_posix1e_mode_to_entry: invalid tag (%d)\n", tag);
}
return (acl_entry);
}
/*
* Utility function to generate a file mode given appropriate ACL entries.
*/
mode_t
acl_posix1e_perms_to_mode(struct acl_entry *acl_user_obj_entry,
struct acl_entry *acl_group_obj_entry, struct acl_entry *acl_other_entry)
{
mode_t mode;
mode = 0;
if (acl_user_obj_entry->ae_perm & ACL_EXECUTE)
mode |= S_IXUSR;
if (acl_user_obj_entry->ae_perm & ACL_READ)
mode |= S_IRUSR;
if (acl_user_obj_entry->ae_perm & ACL_WRITE)
mode |= S_IWUSR;
if (acl_group_obj_entry->ae_perm & ACL_EXECUTE)
mode |= S_IXGRP;
if (acl_group_obj_entry->ae_perm & ACL_READ)
mode |= S_IRGRP;
if (acl_group_obj_entry->ae_perm & ACL_WRITE)
mode |= S_IWGRP;
if (acl_other_entry->ae_perm & ACL_EXECUTE)
mode |= S_IXOTH;
if (acl_other_entry->ae_perm & ACL_READ)
mode |= S_IROTH;
if (acl_other_entry->ae_perm & ACL_WRITE)
mode |= S_IWOTH;
return (mode);
}
/*
* Utility function to generate a file mode given a complete POSIX.1e access
* ACL. Note that if the ACL is improperly formed, this may result in a
* panic.
*/
mode_t
acl_posix1e_acl_to_mode(struct acl *acl)
{
struct acl_entry *acl_mask, *acl_user_obj, *acl_group_obj, *acl_other;
int i;
/*
* Find the ACL entries relevant to a POSIX permission mode.
*/
acl_user_obj = acl_group_obj = acl_other = acl_mask = NULL;
for (i = 0; i < acl->acl_cnt; i++) {
switch (acl->acl_entry[i].ae_tag) {
case ACL_USER_OBJ:
acl_user_obj = &acl->acl_entry[i];
break;
case ACL_GROUP_OBJ:
acl_group_obj = &acl->acl_entry[i];
break;
case ACL_OTHER:
acl_other = &acl->acl_entry[i];
break;
case ACL_MASK:
acl_mask = &acl->acl_entry[i];
break;
case ACL_USER:
case ACL_GROUP:
break;
default:
panic("acl_posix1e_acl_to_mode: bad ae_tag");
}
}
if (acl_user_obj == NULL || acl_group_obj == NULL || acl_other == NULL)
panic("acl_posix1e_acl_to_mode: missing base ae_tags");
/*
* POSIX.1e specifies that if there is an ACL_MASK entry, we replace
* the mode "group" bits with its permissions. If there isn't, we
* use the ACL_GROUP_OBJ permissions.
*/
if (acl_mask != NULL)
return (acl_posix1e_perms_to_mode(acl_user_obj, acl_mask,
acl_other));
else
return (acl_posix1e_perms_to_mode(acl_user_obj, acl_group_obj,
acl_other));
}
/*
* Perform a syntactic check of the ACL, sufficient to allow an implementing
* filesystem to determine if it should accept this and rely on the POSIX.1e
* ACL properties.
*/
int
acl_posix1e_check(struct acl *acl)
{
int num_acl_user_obj, num_acl_user, num_acl_group_obj, num_acl_group;
int num_acl_mask, num_acl_other, i;
/*
* Verify that the number of entries does not exceed the maximum
* defined for acl_t.
*
* Verify that the correct number of various sorts of ae_tags are
* present:
* Exactly one ACL_USER_OBJ
* Exactly one ACL_GROUP_OBJ
* Exactly one ACL_OTHER
* If any ACL_USER or ACL_GROUP entries appear, then exactly one
* ACL_MASK entry must also appear.
*
* Verify that all ae_perm entries are in ACL_PERM_BITS.
*
* Verify all ae_tag entries are understood by this implementation.
*
* Note: Does not check for uniqueness of qualifier (ae_id) field.
*/
num_acl_user_obj = num_acl_user = num_acl_group_obj = num_acl_group =
num_acl_mask = num_acl_other = 0;
if (acl->acl_cnt > ACL_MAX_ENTRIES)
return (EINVAL);
for (i = 0; i < acl->acl_cnt; i++) {
struct acl_entry *ae = &acl->acl_entry[i];
/*
* Check for a valid tag.
*/
switch(ae->ae_tag) {
case ACL_USER_OBJ:
ae->ae_id = ACL_UNDEFINED_ID; /* XXX */
if (ae->ae_id != ACL_UNDEFINED_ID)
return (EINVAL);
num_acl_user_obj++;
break;
case ACL_GROUP_OBJ:
ae->ae_id = ACL_UNDEFINED_ID; /* XXX */
if (ae->ae_id != ACL_UNDEFINED_ID)
return (EINVAL);
num_acl_group_obj++;
break;
case ACL_USER:
if (ae->ae_id == ACL_UNDEFINED_ID)
return (EINVAL);
num_acl_user++;
break;
case ACL_GROUP:
if (ae->ae_id == ACL_UNDEFINED_ID)
return (EINVAL);
num_acl_group++;
break;
case ACL_OTHER:
ae->ae_id = ACL_UNDEFINED_ID; /* XXX */
if (ae->ae_id != ACL_UNDEFINED_ID)
return (EINVAL);
num_acl_other++;
break;
case ACL_MASK:
ae->ae_id = ACL_UNDEFINED_ID; /* XXX */
if (ae->ae_id != ACL_UNDEFINED_ID)
return (EINVAL);
num_acl_mask++;
break;
default:
return (EINVAL);
}
/*
* Check for valid perm entries.
*/
if ((acl->acl_entry[i].ae_perm | ACL_PERM_BITS) !=
ACL_PERM_BITS)
return (EINVAL);
}
if ((num_acl_user_obj != 1) || (num_acl_group_obj != 1) ||
(num_acl_other != 1) || (num_acl_mask != 0 && num_acl_mask != 1))
return (EINVAL);
if (((num_acl_group != 0) || (num_acl_user != 0)) &&
(num_acl_mask != 1))
return (EINVAL);
return (0);
}
/*
* Given a requested mode for a new object, and a default ACL, combine the
* two to produce a new mode. Be careful not to clear any bits that aren't
* intended to be affected by the POSIX.1e ACL. Eventually, this might also
* take the cmask as an argument, if we push that down into
* per-filesystem-code.
*/
mode_t
acl_posix1e_newfilemode(mode_t cmode, struct acl *dacl)
{
mode_t mode;
mode = cmode;
/*
* The current composition policy is that a permission bit must be
* set in *both* the ACL and the requested creation mode for it to
* appear in the resulting mode/ACL. First clear any possibly
* effected bits, then reconstruct.
*/
mode &= ACL_PRESERVE_MASK;
mode |= (ACL_OVERRIDE_MASK & cmode & acl_posix1e_acl_to_mode(dacl));
