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freebsd-dev/sys/kern/subr_acl_nfs4.c
Edward Tomasz Napierala 252e4a96e6 Fix uninitialized variable. 
Found with:	Coverity Prevent(tm)
CID:		8632
2010-10-29 19:07:36 +00:00

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/*-
* Copyright (c) 2008-2009 Edward Tomasz Napierała <trasz@FreeBSD.org>
* All rights reserved.
*
* 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.
*/
/*
* ACL support routines specific to NFSv4 access control lists. These are
* utility routines for code common across file systems implementing NFSv4
* ACLs.
*/
#ifdef _KERNEL
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/priv.h>
#include <sys/vnode.h>
#include <sys/errno.h>
#include <sys/stat.h>
#include <sys/acl.h>
#else
#include <errno.h>
#include <assert.h>
#include <sys/acl.h>
#include <sys/stat.h>
#define KASSERT(a, b) assert(a)
#define CTASSERT(a)
#endif /* _KERNEL */
#ifdef _KERNEL
static struct {
accmode_t accmode;
int mask;
} accmode2mask[] = {{VREAD, ACL_READ_DATA},
{VWRITE, ACL_WRITE_DATA},
{VAPPEND, ACL_APPEND_DATA},
{VEXEC, ACL_EXECUTE},
{VREAD_NAMED_ATTRS, ACL_READ_NAMED_ATTRS},
{VWRITE_NAMED_ATTRS, ACL_WRITE_NAMED_ATTRS},
{VDELETE_CHILD, ACL_DELETE_CHILD},
{VREAD_ATTRIBUTES, ACL_READ_ATTRIBUTES},
{VWRITE_ATTRIBUTES, ACL_WRITE_ATTRIBUTES},
{VDELETE, ACL_DELETE},
{VREAD_ACL, ACL_READ_ACL},
{VWRITE_ACL, ACL_WRITE_ACL},
{VWRITE_OWNER, ACL_WRITE_OWNER},
{VSYNCHRONIZE, ACL_SYNCHRONIZE},
{0, 0}};
static int
_access_mask_from_accmode(accmode_t accmode)
{
int access_mask = 0, i;
for (i = 0; accmode2mask[i].accmode != 0; i++) {
if (accmode & accmode2mask[i].accmode)
access_mask |= accmode2mask[i].mask;
}
/*
* VAPPEND is just a modifier for VWRITE; if the caller asked
* for 'VAPPEND | VWRITE', we want to check for ACL_APPEND_DATA only.
*/
if (access_mask & ACL_APPEND_DATA)
access_mask &= ~ACL_WRITE_DATA;
return (access_mask);
}
/*
* Return 0, iff access is allowed, 1 otherwise.
*/
static int
_acl_denies(const struct acl *aclp, int access_mask, struct ucred *cred,
int file_uid, int file_gid, int *denied_explicitly)
{
int i;
const struct acl_entry *entry;
if (denied_explicitly != NULL)
*denied_explicitly = 0;
KASSERT(aclp->acl_cnt > 0, ("aclp->acl_cnt > 0"));
KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
for (i = 0; i < aclp->acl_cnt; i++) {
entry = &(aclp->acl_entry[i]);
if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
continue;
if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
continue;
switch (entry->ae_tag) {
case ACL_USER_OBJ:
if (file_uid != cred->cr_uid)
continue;
break;
case ACL_USER:
if (entry->ae_id != cred->cr_uid)
continue;
break;
case ACL_GROUP_OBJ:
if (!groupmember(file_gid, cred))
continue;
break;
case ACL_GROUP:
if (!groupmember(entry->ae_id, cred))
continue;
break;
default:
KASSERT(entry->ae_tag == ACL_EVERYONE,
("entry->ae_tag == ACL_EVERYONE"));
}
if (entry->ae_entry_type == ACL_ENTRY_TYPE_DENY) {
if (entry->ae_perm & access_mask) {
if (denied_explicitly != NULL)
*denied_explicitly = 1;
return (1);
}
}
access_mask &= ~(entry->ae_perm);
if (access_mask == 0)
return (0);
}
return (1);
}
int
vaccess_acl_nfs4(enum vtype type, uid_t file_uid, gid_t file_gid,
struct acl *aclp, accmode_t accmode, struct ucred *cred, int *privused)
{
accmode_t priv_granted = 0;
int denied, explicitly_denied, access_mask, is_directory,
must_be_owner = 0;
mode_t file_mode = 0;
KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND |
VEXPLICIT_DENY | VREAD_NAMED_ATTRS | VWRITE_NAMED_ATTRS |
VDELETE_CHILD | VREAD_ATTRIBUTES | VWRITE_ATTRIBUTES | VDELETE |
VREAD_ACL | VWRITE_ACL | VWRITE_OWNER | VSYNCHRONIZE)) == 0,
("invalid bit in accmode"));
KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
("VAPPEND without VWRITE"));
if (privused != NULL)
*privused = 0;
if (accmode & VADMIN)
must_be_owner = 1;
/*
* Ignore VSYNCHRONIZE permission.
*/
accmode &= ~VSYNCHRONIZE;
access_mask = _access_mask_from_accmode(accmode);
if (type == VDIR)
is_directory = 1;
else
is_directory = 0;
/*
* File owner is always allowed to read and write the ACL
* and basic attributes. This is to prevent a situation
* where user would change ACL in a way that prevents him
* from undoing the change.
*/
if (file_uid == cred->cr_uid)
access_mask &= ~(ACL_READ_ACL | ACL_WRITE_ACL |
ACL_READ_ATTRIBUTES | ACL_WRITE_ATTRIBUTES);
/*
* Ignore append permission for regular files; use write
* permission instead.
*/
if (!is_directory && (access_mask & ACL_APPEND_DATA)) {
access_mask &= ~ACL_APPEND_DATA;
access_mask |= ACL_WRITE_DATA;
}
denied = _acl_denies(aclp, access_mask, cred, file_uid, file_gid,
&explicitly_denied);
if (must_be_owner) {
if (file_uid != cred->cr_uid)
denied = EPERM;
}
/*
* For VEXEC, ensure that at least one execute bit is set for
* non-directories. We have to check the mode here to stay
* consistent with execve(2). See the test in
* exec_check_permissions().
*/
acl_nfs4_sync_mode_from_acl(&file_mode, aclp);
if (!denied && !is_directory && (accmode & VEXEC) &&
(file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)
denied = EACCES;
if (!denied)
return (0);
/*
* Access failed. Iff it was not denied explicitly and
* VEXPLICIT_DENY flag was specified, allow access.
*/
if ((accmode & VEXPLICIT_DENY) && explicitly_denied == 0)
return (0);
accmode &= ~VEXPLICIT_DENY;
/*
* No match. Try to use privileges, if there are any.
*/
if (is_directory) {
if ((accmode & VEXEC) && !priv_check_cred(cred,
PRIV_VFS_LOOKUP, 0))
priv_granted |= VEXEC;
} else {
/*
* Ensure that at least one execute bit is on. Otherwise,
* a privileged user will always succeed, and we don't want
* this to happen unless the file really is executable.
*/
if ((accmode & VEXEC) && (file_mode &
(S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
!priv_check_cred(cred, PRIV_VFS_EXEC, 0))
priv_granted |= VEXEC;
}
if ((accmode & VREAD) && !priv_check_cred(cred, PRIV_VFS_READ, 0))
priv_granted |= VREAD;
if ((accmode & (VWRITE | VAPPEND | VDELETE_CHILD)) &&
!priv_check_cred(cred, PRIV_VFS_WRITE, 0))
priv_granted |= (VWRITE | VAPPEND | VDELETE_CHILD);
if ((accmode & VADMIN_PERMS) &&
!priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
priv_granted |= VADMIN_PERMS;
if ((accmode & VSTAT_PERMS) &&
!priv_check_cred(cred, PRIV_VFS_STAT, 0))
priv_granted |= VSTAT_PERMS;
if ((accmode & priv_granted) == accmode) {
if (privused != NULL)
*privused = 1;
return (0);
}
if (accmode & (VADMIN_PERMS | VDELETE_CHILD | VDELETE))
denied = EPERM;
else
denied = EACCES;
return (denied);
}
#endif /* _KERNEL */
static int
_acl_entry_matches(struct acl_entry *entry, acl_tag_t tag, acl_perm_t perm,
acl_entry_type_t entry_type)
{
if (entry->ae_tag != tag)
return (0);
if (entry->ae_id != ACL_UNDEFINED_ID)
return (0);
if (entry->ae_perm != perm)
return (0);
if (entry->ae_entry_type != entry_type)
return (0);
if (entry->ae_flags != 0)
return (0);
return (1);
}
static struct acl_entry *
_acl_append(struct acl *aclp, acl_tag_t tag, acl_perm_t perm,
acl_entry_type_t entry_type)
{
struct acl_entry *entry;
KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
entry = &(aclp->acl_entry[aclp->acl_cnt]);
aclp->acl_cnt++;
entry->ae_tag = tag;
entry->ae_id = ACL_UNDEFINED_ID;
entry->ae_perm = perm;
entry->ae_entry_type = entry_type;
entry->ae_flags = 0;
return (entry);
}
static struct acl_entry *
_acl_duplicate_entry(struct acl *aclp, int entry_index)
{
int i;
KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
for (i = aclp->acl_cnt; i > entry_index; i--)
aclp->acl_entry[i] = aclp->acl_entry[i - 1];
aclp->acl_cnt++;
return (&(aclp->acl_entry[entry_index + 1]));
}
/*
* Calculate trivial ACL in a manner compatible with PSARC/2010/029.
* Note that this results in an ACL different from (but semantically
* equal to) the "canonical six" trivial ACL computed using algorithm
* described in draft-ietf-nfsv4-minorversion1-03.txt, 3.16.6.2.
*/
void
acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode)
{
acl_perm_t user_allow_first = 0, user_deny = 0, group_deny = 0;
acl_perm_t user_allow, group_allow, everyone_allow;
KASSERT(aclp->acl_cnt == 0, ("aclp->acl_cnt == 0"));
user_allow = group_allow = everyone_allow = ACL_READ_ACL |
ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS | ACL_SYNCHRONIZE;
user_allow |= ACL_WRITE_ACL | ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
ACL_WRITE_NAMED_ATTRS;
if (mode & S_IRUSR)
user_allow |= ACL_READ_DATA;
if (mode & S_IWUSR)
user_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
if (mode & S_IXUSR)
user_allow |= ACL_EXECUTE;
if (mode & S_IRGRP)
group_allow |= ACL_READ_DATA;
if (mode & S_IWGRP)
group_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
if (mode & S_IXGRP)
group_allow |= ACL_EXECUTE;
if (mode & S_IROTH)
everyone_allow |= ACL_READ_DATA;
if (mode & S_IWOTH)
everyone_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
if (mode & S_IXOTH)
everyone_allow |= ACL_EXECUTE;
user_deny = ((group_allow | everyone_allow) & ~user_allow);
group_deny = everyone_allow & ~group_allow;
user_allow_first = group_deny & ~user_deny;
if (user_allow_first != 0)
_acl_append(aclp, ACL_USER_OBJ, user_allow_first, ACL_ENTRY_TYPE_ALLOW);
if (user_deny != 0)
_acl_append(aclp, ACL_USER_OBJ, user_deny, ACL_ENTRY_TYPE_DENY);
if (group_deny != 0)
_acl_append(aclp, ACL_GROUP_OBJ, group_deny, ACL_ENTRY_TYPE_DENY);
_acl_append(aclp, ACL_USER_OBJ, user_allow, ACL_ENTRY_TYPE_ALLOW);
_acl_append(aclp, ACL_GROUP_OBJ, group_allow, ACL_ENTRY_TYPE_ALLOW);
_acl_append(aclp, ACL_EVERYONE, everyone_allow, ACL_ENTRY_TYPE_ALLOW);
}
void
acl_nfs4_sync_acl_from_mode(struct acl *aclp, mode_t mode, int file_owner_id)
{
int i, meets, must_append;
struct acl_entry *entry, *copy, *previous,
*a1, *a2, *a3, *a4, *a5, *a6;
mode_t amode;
const int READ = 04;
const int WRITE = 02;
const int EXEC = 01;
KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
/*
* NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
*
* 3.16.6.3. Applying a Mode to an Existing ACL
*/
/*
* 1. For each ACE:
*/
for (i = 0; i < aclp->acl_cnt; i++) {
entry = &(aclp->acl_entry[i]);
/*
* 1.1. If the type is neither ALLOW or DENY - skip.
*/
if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
continue;
/*
* 1.2. If ACL_ENTRY_INHERIT_ONLY is set - skip.
*/
if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
continue;
/*
* 1.3. If ACL_ENTRY_FILE_INHERIT or ACL_ENTRY_DIRECTORY_INHERIT
* are set:
*/
if (entry->ae_flags &
(ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT)) {
/*
* 1.3.1. A copy of the current ACE is made, and placed
* in the ACL immediately following the current
* ACE.
*/
copy = _acl_duplicate_entry(aclp, i);
/*
* 1.3.2. In the first ACE, the flag
* ACL_ENTRY_INHERIT_ONLY is set.
*/
entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
/*
* 1.3.3. In the second ACE, the following flags
* are cleared:
* ACL_ENTRY_FILE_INHERIT,
* ACL_ENTRY_DIRECTORY_INHERIT,
* ACL_ENTRY_NO_PROPAGATE_INHERIT.
*/
copy->ae_flags &= ~(ACL_ENTRY_FILE_INHERIT |
ACL_ENTRY_DIRECTORY_INHERIT |
ACL_ENTRY_NO_PROPAGATE_INHERIT);
/*
* The algorithm continues on with the second ACE.
*/
i++;
entry = copy;
}
/*
* 1.4. If it's owner@, group@ or everyone@ entry, clear
* ACL_READ_DATA, ACL_WRITE_DATA, ACL_APPEND_DATA
* and ACL_EXECUTE. Continue to the next entry.
*/
if (entry->ae_tag == ACL_USER_OBJ ||
entry->ae_tag == ACL_GROUP_OBJ ||
entry->ae_tag == ACL_EVERYONE) {
entry->ae_perm &= ~(ACL_READ_DATA | ACL_WRITE_DATA |
ACL_APPEND_DATA | ACL_EXECUTE);
continue;
}
/*
* 1.5. Otherwise, if the "who" field did not match one
* of OWNER@, GROUP@, EVERYONE@:
*
* 1.5.1. If the type is ALLOW, check the preceding ACE.
* If it does not meet all of the following criteria:
*/
if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW)
continue;
meets = 0;
if (i > 0) {
meets = 1;
previous = &(aclp->acl_entry[i - 1]);
/*
* 1.5.1.1. The type field is DENY,
*/
if (previous->ae_entry_type != ACL_ENTRY_TYPE_DENY)
meets = 0;
/*
* 1.5.1.2. The "who" field is the same as the current
* ACE,
*
* 1.5.1.3. The flag bit ACE4_IDENTIFIER_GROUP
* is the same as it is in the current ACE,
* and no other flag bits are set,
*/
if (previous->ae_id != entry->ae_id ||
previous->ae_tag != entry->ae_tag)
meets = 0;
if (previous->ae_flags)
meets = 0;
/*
* 1.5.1.4. The mask bits are a subset of the mask bits
* of the current ACE, and are also subset of
* the following: ACL_READ_DATA,
* ACL_WRITE_DATA, ACL_APPEND_DATA, ACL_EXECUTE
*/
if (previous->ae_perm & ~(entry->ae_perm))
meets = 0;
if (previous->ae_perm & ~(ACL_READ_DATA |
ACL_WRITE_DATA | ACL_APPEND_DATA | ACL_EXECUTE))
meets = 0;
}
if (!meets) {
/*
* Then the ACE of type DENY, with a who equal
* to the current ACE, flag bits equal to
* (<current ACE flags> & <ACE_IDENTIFIER_GROUP>)
* and no mask bits, is prepended.
*/
previous = entry;
entry = _acl_duplicate_entry(aclp, i);
/* Adjust counter, as we've just added an entry. */
i++;
previous->ae_tag = entry->ae_tag;
previous->ae_id = entry->ae_id;
previous->ae_flags = entry->ae_flags;
previous->ae_perm = 0;
previous->ae_entry_type = ACL_ENTRY_TYPE_DENY;
}
/*
* 1.5.2. The following modifications are made to the prepended
* ACE. The intent is to mask the following ACE
* to disallow ACL_READ_DATA, ACL_WRITE_DATA,
* ACL_APPEND_DATA, or ACL_EXECUTE, based upon the group
* permissions of the new mode. As a special case,
* if the ACE matches the current owner of the file,
* the owner bits are used, rather than the group bits.
* This is reflected in the algorithm below.
*/
amode = mode >> 3;
/*
* If ACE4_IDENTIFIER_GROUP is not set, and the "who" field
* in ACE matches the owner of the file, we shift amode three
* more bits, in order to have the owner permission bits
* placed in the three low order bits of amode.
*/
if (entry->ae_tag == ACL_USER && entry->ae_id == file_owner_id)
amode = amode >> 3;
if (entry->ae_perm & ACL_READ_DATA) {
if (amode & READ)
previous->ae_perm &= ~ACL_READ_DATA;
else
previous->ae_perm |= ACL_READ_DATA;
}
if (entry->ae_perm & ACL_WRITE_DATA) {
if (amode & WRITE)
previous->ae_perm &= ~ACL_WRITE_DATA;
else
previous->ae_perm |= ACL_WRITE_DATA;
}
if (entry->ae_perm & ACL_APPEND_DATA) {
if (amode & WRITE)
previous->ae_perm &= ~ACL_APPEND_DATA;
else
previous->ae_perm |= ACL_APPEND_DATA;
}
if (entry->ae_perm & ACL_EXECUTE) {
if (amode & EXEC)
previous->ae_perm &= ~ACL_EXECUTE;
else
previous->ae_perm |= ACL_EXECUTE;
}
/*
* 1.5.3. If ACE4_IDENTIFIER_GROUP is set in the flags
* of the ALLOW ace:
*
* XXX: This point is not there in the Falkner's draft.
*/
if (entry->ae_tag == ACL_GROUP &&
entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) {
mode_t extramode, ownermode;
extramode = (mode >> 3) & 07;
ownermode = mode >> 6;
extramode &= ~ownermode;
if (extramode) {
if (extramode & READ) {
entry->ae_perm &= ~ACL_READ_DATA;
previous->ae_perm &= ~ACL_READ_DATA;
}
if (extramode & WRITE) {
entry->ae_perm &=
~(ACL_WRITE_DATA | ACL_APPEND_DATA);
previous->ae_perm &=
~(ACL_WRITE_DATA | ACL_APPEND_DATA);
}
if (extramode & EXEC) {
entry->ae_perm &= ~ACL_EXECUTE;
previous->ae_perm &= ~ACL_EXECUTE;
}
}
}
}
/*
* 2. If there at least six ACEs, the final six ACEs are examined.
* If they are not equal to what we want, append six ACEs.
*/
must_append = 0;
if (aclp->acl_cnt < 6) {
must_append = 1;
} else {
a6 = &(aclp->acl_entry[aclp->acl_cnt - 1]);
a5 = &(aclp->acl_entry[aclp->acl_cnt - 2]);
a4 = &(aclp->acl_entry[aclp->acl_cnt - 3]);
a3 = &(aclp->acl_entry[aclp->acl_cnt - 4]);
a2 = &(aclp->acl_entry[aclp->acl_cnt - 5]);
a1 = &(aclp->acl_entry[aclp->acl_cnt - 6]);
if (!_acl_entry_matches(a1, ACL_USER_OBJ, 0,
ACL_ENTRY_TYPE_DENY))
must_append = 1;
if (!_acl_entry_matches(a2, ACL_USER_OBJ, ACL_WRITE_ACL |
ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW))
must_append = 1;
if (!_acl_entry_matches(a3, ACL_GROUP_OBJ, 0,
ACL_ENTRY_TYPE_DENY))
must_append = 1;
if (!_acl_entry_matches(a4, ACL_GROUP_OBJ, 0,
ACL_ENTRY_TYPE_ALLOW))
must_append = 1;
if (!_acl_entry_matches(a5, ACL_EVERYONE, ACL_WRITE_ACL |
ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY))
must_append = 1;
if (!_acl_entry_matches(a6, ACL_EVERYONE, ACL_READ_ACL |
ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW))
must_append = 1;
}
if (must_append) {
KASSERT(aclp->acl_cnt + 6 <= ACL_MAX_ENTRIES,
("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
a1 = _acl_append(aclp, ACL_USER_OBJ, 0, ACL_ENTRY_TYPE_DENY);
a2 = _acl_append(aclp, ACL_USER_OBJ, ACL_WRITE_ACL |
ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW);
a3 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_DENY);
a4 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_ALLOW);
a5 = _acl_append(aclp, ACL_EVERYONE, ACL_WRITE_ACL |
ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY);
a6 = _acl_append(aclp, ACL_EVERYONE, ACL_READ_ACL |
ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW);
KASSERT(a1 != NULL && a2 != NULL && a3 != NULL && a4 != NULL &&
a5 != NULL && a6 != NULL, ("couldn't append to ACL."));
}
/*
* 3. The final six ACEs are adjusted according to the incoming mode.
*/
if (mode & S_IRUSR)
a2->ae_perm |= ACL_READ_DATA;
else
a1->ae_perm |= ACL_READ_DATA;
if (mode & S_IWUSR)
a2->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
else
a1->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
if (mode & S_IXUSR)
a2->ae_perm |= ACL_EXECUTE;
else
a1->ae_perm |= ACL_EXECUTE;
if (mode & S_IRGRP)
a4->ae_perm |= ACL_READ_DATA;
else
a3->ae_perm |= ACL_READ_DATA;
if (mode & S_IWGRP)
a4->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
else
a3->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
if (mode & S_IXGRP)
a4->ae_perm |= ACL_EXECUTE;
else
a3->ae_perm |= ACL_EXECUTE;
if (mode & S_IROTH)
a6->ae_perm |= ACL_READ_DATA;
else
a5->ae_perm |= ACL_READ_DATA;
if (mode & S_IWOTH)
a6->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
else
a5->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
if (mode & S_IXOTH)
a6->ae_perm |= ACL_EXECUTE;
else
a5->ae_perm |= ACL_EXECUTE;
}
void
acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp)
{
int i;
mode_t old_mode = *_mode, mode = 0, seen = 0;
const struct acl_entry *entry;
KASSERT(aclp->acl_cnt > 0, ("aclp->acl_cnt > 0"));
KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
/*
* NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
*
* 3.16.6.1. Recomputing mode upon SETATTR of ACL
*/
for (i = 0; i < aclp->acl_cnt; i++) {
entry = &(aclp->acl_entry[i]);
if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
continue;
if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
continue;
if (entry->ae_tag == ACL_USER_OBJ) {
if ((entry->ae_perm & ACL_READ_DATA) &&
((seen & S_IRUSR) == 0)) {
seen |= S_IRUSR;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IRUSR;
}
if ((entry->ae_perm & ACL_WRITE_DATA) &&
((seen & S_IWUSR) == 0)) {
seen |= S_IWUSR;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IWUSR;
}
if ((entry->ae_perm & ACL_EXECUTE) &&
((seen & S_IXUSR) == 0)) {
seen |= S_IXUSR;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IXUSR;
}
} else if (entry->ae_tag == ACL_GROUP_OBJ) {
if ((entry->ae_perm & ACL_READ_DATA) &&
((seen & S_IRGRP) == 0)) {
seen |= S_IRGRP;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IRGRP;
}
if ((entry->ae_perm & ACL_WRITE_DATA) &&
((seen & S_IWGRP) == 0)) {
seen |= S_IWGRP;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IWGRP;
}
if ((entry->ae_perm & ACL_EXECUTE) &&
((seen & S_IXGRP) == 0)) {
seen |= S_IXGRP;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IXGRP;
}
} else if (entry->ae_tag == ACL_EVERYONE) {
if (entry->ae_perm & ACL_READ_DATA) {
if ((seen & S_IRUSR) == 0) {
seen |= S_IRUSR;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IRUSR;
}
if ((seen & S_IRGRP) == 0) {
seen |= S_IRGRP;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IRGRP;
}
if ((seen & S_IROTH) == 0) {
seen |= S_IROTH;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IROTH;
}
}
if (entry->ae_perm & ACL_WRITE_DATA) {
if ((seen & S_IWUSR) == 0) {
seen |= S_IWUSR;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IWUSR;
}
if ((seen & S_IWGRP) == 0) {
seen |= S_IWGRP;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IWGRP;
}
if ((seen & S_IWOTH) == 0) {
seen |= S_IWOTH;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IWOTH;
}
}
if (entry->ae_perm & ACL_EXECUTE) {
if ((seen & S_IXUSR) == 0) {
seen |= S_IXUSR;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IXUSR;
}
if ((seen & S_IXGRP) == 0) {
seen |= S_IXGRP;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IXGRP;
}
if ((seen & S_IXOTH) == 0) {
seen |= S_IXOTH;
if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
mode |= S_IXOTH;
}
}
}
}
*_mode = mode | (old_mode & ACL_PRESERVE_MASK);
}
void
acl_nfs4_compute_inherited_acl(const struct acl *parent_aclp,
struct acl *child_aclp, mode_t mode, int file_owner_id,
int is_directory)
{
int i, flags;
const struct acl_entry *parent_entry;
struct acl_entry *entry, *copy;
KASSERT(child_aclp->acl_cnt == 0, ("child_aclp->acl_cnt == 0"));
KASSERT(parent_aclp->acl_cnt > 0, ("parent_aclp->acl_cnt > 0"));
KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
/*
* NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
*
* 3.16.6.2. Applying the mode given to CREATE or OPEN
* to an inherited ACL
*/
/*
* 1. Form an ACL that is the concatenation of all inheritable ACEs.
*/
for (i = 0; i < parent_aclp->acl_cnt; i++) {
parent_entry = &(parent_aclp->acl_entry[i]);
flags = parent_entry->ae_flags;
/*
* Entry is not inheritable at all.
*/
if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
ACL_ENTRY_FILE_INHERIT)) == 0)
continue;
/*
* We're creating a file, but entry is not inheritable
* by files.
*/
if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
continue;
/*
* Entry is inheritable only by files, but has NO_PROPAGATE
* flag set, and we're creating a directory, so it wouldn't
* propagate to any file in that directory anyway.
*/
if (is_directory &&
(flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
(flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
continue;
KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
child_aclp->acl_entry[child_aclp->acl_cnt] = *parent_entry;
child_aclp->acl_cnt++;
}
/*
* 2. For each entry in the new ACL, adjust its flags, possibly
* creating two entries in place of one.
*/
for (i = 0; i < child_aclp->acl_cnt; i++) {
entry = &(child_aclp->acl_entry[i]);
/*
* This is not in the specification, but SunOS
* apparently does that.
*/
if (((entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT) ||
!is_directory) &&
entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
/*
* 2.A. If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if the object
* being created is not a directory, then clear the
* following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
* ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
* ACL_ENTRY_INHERIT_ONLY.
*/
if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
!is_directory) {
entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
ACL_ENTRY_INHERIT_ONLY);
/*
* Continue on to the next ACE.
*/
continue;
}
/*
* 2.B. If the object is a directory and ACL_ENTRY_FILE_INHERIT
* is set, but ACL_ENTRY_NO_PROPAGATE_INHERIT is not set, ensure
* that ACL_ENTRY_INHERIT_ONLY is set. Continue to the
* next ACE. Otherwise...
*/
/*
* XXX: Read it again and make sure what does the "otherwise"
* apply to.
*/
if (is_directory &&
(entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
continue;
}
/*
* 2.C. If the type of the ACE is neither ALLOW nor deny,
* then continue.
*/
if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
continue;
/*
* 2.D. Copy the original ACE into a second, adjacent ACE.
*/
copy = _acl_duplicate_entry(child_aclp, i);
/*
* 2.E. On the first ACE, ensure that ACL_ENTRY_INHERIT_ONLY
* is set.
*/
entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
/*
* 2.F. On the second ACE, clear the following flags:
* ACL_ENTRY_NO_PROPAGATE_INHERIT, ACL_ENTRY_FILE_INHERIT,
* ACL_ENTRY_DIRECTORY_INHERIT, ACL_ENTRY_INHERIT_ONLY.
*/
copy->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
ACL_ENTRY_INHERIT_ONLY);
/*
* 2.G. On the second ACE, if the type is ALLOW,
* an implementation MAY clear the following
* mask bits: ACL_WRITE_ACL, ACL_WRITE_OWNER.
*/
if (copy->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
copy->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
/*
* Increment the counter to skip the copied entry.
*/
i++;
}
/*
* 3. To ensure that the mode is honored, apply the algorithm describe
* in Section 2.16.6.3, using the mode that is to be used for file
* creation.
*/
acl_nfs4_sync_acl_from_mode(child_aclp, mode, file_owner_id);
}
#ifdef _KERNEL
static int
_acls_are_equal(const struct acl *a, const struct acl *b)
{
int i;
const struct acl_entry *entrya, *entryb;
if (a->acl_cnt != b->acl_cnt)
return (0);
for (i = 0; i < b->acl_cnt; i++) {
entrya = &(a->acl_entry[i]);
entryb = &(b->acl_entry[i]);
if (entrya->ae_tag != entryb->ae_tag ||
entrya->ae_id != entryb->ae_id ||
entrya->ae_perm != entryb->ae_perm ||
entrya->ae_entry_type != entryb->ae_entry_type ||
entrya->ae_flags != entryb->ae_flags)
return (0);
}
return (1);
}
/*
* This routine is used to determine whether to remove extended attribute
* that stores ACL contents.
*/
int
acl_nfs4_is_trivial(const struct acl *aclp, int file_owner_id)
{
int trivial;
mode_t tmpmode = 0;
struct acl *tmpaclp;
if (aclp->acl_cnt != 6)
return (0);
/*
* Compute the mode from the ACL, then compute new ACL from that mode.
* If the ACLs are identical, then the ACL is trivial.
*
* XXX: I guess there is a faster way to do this. However, even
* this slow implementation significantly speeds things up
* for files that don't have non-trivial ACLs - it's critical
* for performance to not use EA when they are not needed.
*/
tmpaclp = acl_alloc(M_WAITOK | M_ZERO);
acl_nfs4_sync_mode_from_acl(&tmpmode, aclp);
acl_nfs4_sync_acl_from_mode(tmpaclp, tmpmode, file_owner_id);
trivial = _acls_are_equal(aclp, tmpaclp);
acl_free(tmpaclp);
return (trivial);
}
#endif /* _KERNEL */
int
acl_nfs4_check(const struct acl *aclp, int is_directory)
{
int i;
const struct acl_entry *entry;
/*
* The spec doesn't seem to say anything about ACL validity.
* It seems there is not much to do here. There is even no need
* to count "owner@" or "everyone@" (ACL_USER_OBJ and ACL_EVERYONE)
* entries, as there can be several of them and that's perfectly
* valid. There can be none of them too. Really.
*/
if (aclp->acl_cnt > ACL_MAX_ENTRIES || aclp->acl_cnt <= 0)
return (EINVAL);
for (i = 0; i < aclp->acl_cnt; i++) {
entry = &(aclp->acl_entry[i]);
switch (entry->ae_tag) {
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_EVERYONE:
if (entry->ae_id != ACL_UNDEFINED_ID)
return (EINVAL);
break;
case ACL_USER:
case ACL_GROUP:
if (entry->ae_id == ACL_UNDEFINED_ID)
return (EINVAL);
break;
default:
return (EINVAL);
}
if ((entry->ae_perm | ACL_NFS4_PERM_BITS) != ACL_NFS4_PERM_BITS)
return (EINVAL);
/*
* Disallow ACL_ENTRY_TYPE_AUDIT and ACL_ENTRY_TYPE_ALARM for now.
*/
if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
return (EINVAL);
if ((entry->ae_flags | ACL_FLAGS_BITS) != ACL_FLAGS_BITS)
return (EINVAL);
/* Disallow unimplemented flags. */
if (entry->ae_flags & (ACL_ENTRY_SUCCESSFUL_ACCESS |
ACL_ENTRY_FAILED_ACCESS))
return (EINVAL);
/* Disallow flags not allowed for ordinary files. */
if (!is_directory) {
if (entry->ae_flags & (ACL_ENTRY_FILE_INHERIT |
ACL_ENTRY_DIRECTORY_INHERIT |
ACL_ENTRY_NO_PROPAGATE_INHERIT | ACL_ENTRY_INHERIT_ONLY))
return (EINVAL);
}
}
return (0);
}
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