freebsd-skq/sys/kern/subr_acl_nfs4.c
Edward Tomasz Napierala c0d345beb1 Add part of NFSv4 ACL kernel support code that is required for the upcoming
libc changes to work.  Not connected to the kernel build yet; for now,
it will be compiled into libc.

Reviewed by:	rwatson
2009-06-09 19:51:22 +00:00

580 lines
16 KiB
C

/*-
* Copyright (c) 2008 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
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]));
}
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 >= 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
*
* 3.16.6.3. 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);
}