linux/fs/nfsd/nfs4acl.c
Christian Brauner cac2f8b8d8
fs: rename current get acl method
The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].

The current inode operation for getting posix acls takes an inode
argument but various filesystems (e.g., 9p, cifs, overlayfs) need access
to the dentry. In contrast to the ->set_acl() inode operation we cannot
simply extend ->get_acl() to take a dentry argument. The ->get_acl()
inode operation is called from:

acl_permission_check()
-> check_acl()
   -> get_acl()

which is part of generic_permission() which in turn is part of
inode_permission(). Both generic_permission() and inode_permission() are
called in the ->permission() handler of various filesystems (e.g.,
overlayfs). So simply passing a dentry argument to ->get_acl() would
amount to also having to pass a dentry argument to ->permission(). We
should avoid this unnecessary change.

So instead of extending the existing inode operation rename it from
->get_acl() to ->get_inode_acl() and add a ->get_acl() method later that
passes a dentry argument and which filesystems that need access to the
dentry can implement instead of ->get_inode_acl(). Filesystems like cifs
which allow setting and getting posix acls but not using them for
permission checking during lookup can simply not implement
->get_inode_acl().

This is intended to be a non-functional change.

Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1]
Suggested-by/Inspired-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-10-20 10:13:27 +02:00

854 lines
21 KiB
C

/*
* Common NFSv4 ACL handling code.
*
* Copyright (c) 2002, 2003 The Regents of the University of Michigan.
* All rights reserved.
*
* Marius Aamodt Eriksen <marius@umich.edu>
* Jeff Sedlak <jsedlak@umich.edu>
* J. Bruce Fields <bfields@umich.edu>
*
* 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.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``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 REGENTS 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 <linux/fs.h>
#include <linux/slab.h>
#include <linux/posix_acl.h>
#include "nfsfh.h"
#include "nfsd.h"
#include "acl.h"
#include "vfs.h"
#define NFS4_ACL_TYPE_DEFAULT 0x01
#define NFS4_ACL_DIR 0x02
#define NFS4_ACL_OWNER 0x04
/* mode bit translations: */
#define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
#define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
#define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
#define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
#define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
/* flags used to simulate posix default ACLs */
#define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
| NFS4_ACE_DIRECTORY_INHERIT_ACE)
#define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
| NFS4_ACE_INHERIT_ONLY_ACE \
| NFS4_ACE_IDENTIFIER_GROUP)
static u32
mask_from_posix(unsigned short perm, unsigned int flags)
{
int mask = NFS4_ANYONE_MODE;
if (flags & NFS4_ACL_OWNER)
mask |= NFS4_OWNER_MODE;
if (perm & ACL_READ)
mask |= NFS4_READ_MODE;
if (perm & ACL_WRITE)
mask |= NFS4_WRITE_MODE;
if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
mask |= NFS4_ACE_DELETE_CHILD;
if (perm & ACL_EXECUTE)
mask |= NFS4_EXECUTE_MODE;
return mask;
}
static u32
deny_mask_from_posix(unsigned short perm, u32 flags)
{
u32 mask = 0;
if (perm & ACL_READ)
mask |= NFS4_READ_MODE;
if (perm & ACL_WRITE)
mask |= NFS4_WRITE_MODE;
if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
mask |= NFS4_ACE_DELETE_CHILD;
if (perm & ACL_EXECUTE)
mask |= NFS4_EXECUTE_MODE;
return mask;
}
/* XXX: modify functions to return NFS errors; they're only ever
* used by nfs code, after all.... */
/* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the
* side of being more restrictive, so the mode bit mapping below is
* pessimistic. An optimistic version would be needed to handle DENY's,
* but we expect to coalesce all ALLOWs and DENYs before mapping to mode
* bits. */
static void
low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
{
u32 write_mode = NFS4_WRITE_MODE;
if (flags & NFS4_ACL_DIR)
write_mode |= NFS4_ACE_DELETE_CHILD;
*mode = 0;
if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
*mode |= ACL_READ;
if ((perm & write_mode) == write_mode)
*mode |= ACL_WRITE;
if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
*mode |= ACL_EXECUTE;
}
static short ace2type(struct nfs4_ace *);
static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
unsigned int);
int
nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
struct nfs4_acl **acl)
{
struct inode *inode = d_inode(dentry);
int error = 0;
struct posix_acl *pacl = NULL, *dpacl = NULL;
unsigned int flags = 0;
int size = 0;
pacl = get_inode_acl(inode, ACL_TYPE_ACCESS);
if (!pacl)
pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
if (IS_ERR(pacl))
return PTR_ERR(pacl);
/* allocate for worst case: one (deny, allow) pair each: */
size += 2 * pacl->a_count;
if (S_ISDIR(inode->i_mode)) {
flags = NFS4_ACL_DIR;
dpacl = get_inode_acl(inode, ACL_TYPE_DEFAULT);
if (IS_ERR(dpacl)) {
error = PTR_ERR(dpacl);
goto rel_pacl;
}
if (dpacl)
size += 2 * dpacl->a_count;
}
*acl = kmalloc(nfs4_acl_bytes(size), GFP_KERNEL);
if (*acl == NULL) {
error = -ENOMEM;
goto out;
}
(*acl)->naces = 0;
_posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
if (dpacl)
_posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT);
out:
posix_acl_release(dpacl);
rel_pacl:
posix_acl_release(pacl);
return error;
}
struct posix_acl_summary {
unsigned short owner;
unsigned short users;
unsigned short group;
unsigned short groups;
unsigned short other;
unsigned short mask;
};
static void
summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas)
{
struct posix_acl_entry *pa, *pe;
/*
* Only pas.users and pas.groups need initialization; previous
* posix_acl_valid() calls ensure that the other fields will be
* initialized in the following loop. But, just to placate gcc:
*/
memset(pas, 0, sizeof(*pas));
pas->mask = 07;
pe = acl->a_entries + acl->a_count;
FOREACH_ACL_ENTRY(pa, acl, pe) {
switch (pa->e_tag) {
case ACL_USER_OBJ:
pas->owner = pa->e_perm;
break;
case ACL_GROUP_OBJ:
pas->group = pa->e_perm;
break;
case ACL_USER:
pas->users |= pa->e_perm;
break;
case ACL_GROUP:
pas->groups |= pa->e_perm;
break;
case ACL_OTHER:
pas->other = pa->e_perm;
break;
case ACL_MASK:
pas->mask = pa->e_perm;
break;
}
}
/* We'll only care about effective permissions: */
pas->users &= pas->mask;
pas->group &= pas->mask;
pas->groups &= pas->mask;
}
/* We assume the acl has been verified with posix_acl_valid. */
static void
_posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
unsigned int flags)
{
struct posix_acl_entry *pa, *group_owner_entry;
struct nfs4_ace *ace;
struct posix_acl_summary pas;
unsigned short deny;
int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0);
BUG_ON(pacl->a_count < 3);
summarize_posix_acl(pacl, &pas);
pa = pacl->a_entries;
ace = acl->aces + acl->naces;
/* We could deny everything not granted by the owner: */
deny = ~pas.owner;
/*
* but it is equivalent (and simpler) to deny only what is not
* granted by later entries:
*/
deny &= pas.users | pas.group | pas.groups | pas.other;
if (deny) {
ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
ace->flag = eflag;
ace->access_mask = deny_mask_from_posix(deny, flags);
ace->whotype = NFS4_ACL_WHO_OWNER;
ace++;
acl->naces++;
}
ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
ace->flag = eflag;
ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
ace->whotype = NFS4_ACL_WHO_OWNER;
ace++;
acl->naces++;
pa++;
while (pa->e_tag == ACL_USER) {
deny = ~(pa->e_perm & pas.mask);
deny &= pas.groups | pas.group | pas.other;
if (deny) {
ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
ace->flag = eflag;
ace->access_mask = deny_mask_from_posix(deny, flags);
ace->whotype = NFS4_ACL_WHO_NAMED;
ace->who_uid = pa->e_uid;
ace++;
acl->naces++;
}
ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
ace->flag = eflag;
ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
flags);
ace->whotype = NFS4_ACL_WHO_NAMED;
ace->who_uid = pa->e_uid;
ace++;
acl->naces++;
pa++;
}
/* In the case of groups, we apply allow ACEs first, then deny ACEs,
* since a user can be in more than one group. */
/* allow ACEs */
group_owner_entry = pa;
ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
ace->flag = eflag;
ace->access_mask = mask_from_posix(pas.group, flags);
ace->whotype = NFS4_ACL_WHO_GROUP;
ace++;
acl->naces++;
pa++;
while (pa->e_tag == ACL_GROUP) {
ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
flags);
ace->whotype = NFS4_ACL_WHO_NAMED;
ace->who_gid = pa->e_gid;
ace++;
acl->naces++;
pa++;
}
/* deny ACEs */
pa = group_owner_entry;
deny = ~pas.group & pas.other;
if (deny) {
ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
ace->flag = eflag;
ace->access_mask = deny_mask_from_posix(deny, flags);
ace->whotype = NFS4_ACL_WHO_GROUP;
ace++;
acl->naces++;
}
pa++;
while (pa->e_tag == ACL_GROUP) {
deny = ~(pa->e_perm & pas.mask);
deny &= pas.other;
if (deny) {
ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
ace->access_mask = deny_mask_from_posix(deny, flags);
ace->whotype = NFS4_ACL_WHO_NAMED;
ace->who_gid = pa->e_gid;
ace++;
acl->naces++;
}
pa++;
}
if (pa->e_tag == ACL_MASK)
pa++;
ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
ace->flag = eflag;
ace->access_mask = mask_from_posix(pa->e_perm, flags);
ace->whotype = NFS4_ACL_WHO_EVERYONE;
acl->naces++;
}
static bool
pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2)
{
if (pace1->e_tag != pace2->e_tag)
return pace1->e_tag > pace2->e_tag;
if (pace1->e_tag == ACL_USER)
return uid_gt(pace1->e_uid, pace2->e_uid);
if (pace1->e_tag == ACL_GROUP)
return gid_gt(pace1->e_gid, pace2->e_gid);
return false;
}
static void
sort_pacl_range(struct posix_acl *pacl, int start, int end) {
int sorted = 0, i;
/* We just do a bubble sort; easy to do in place, and we're not
* expecting acl's to be long enough to justify anything more. */
while (!sorted) {
sorted = 1;
for (i = start; i < end; i++) {
if (pace_gt(&pacl->a_entries[i],
&pacl->a_entries[i+1])) {
sorted = 0;
swap(pacl->a_entries[i],
pacl->a_entries[i + 1]);
}
}
}
}
static void
sort_pacl(struct posix_acl *pacl)
{
/* posix_acl_valid requires that users and groups be in order
* by uid/gid. */
int i, j;
/* no users or groups */
if (!pacl || pacl->a_count <= 4)
return;
i = 1;
while (pacl->a_entries[i].e_tag == ACL_USER)
i++;
sort_pacl_range(pacl, 1, i-1);
BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
j = ++i;
while (pacl->a_entries[j].e_tag == ACL_GROUP)
j++;
sort_pacl_range(pacl, i, j-1);
return;
}
/*
* While processing the NFSv4 ACE, this maintains bitmasks representing
* which permission bits have been allowed and which denied to a given
* entity: */
struct posix_ace_state {
u32 allow;
u32 deny;
};
struct posix_user_ace_state {
union {
kuid_t uid;
kgid_t gid;
};
struct posix_ace_state perms;
};
struct posix_ace_state_array {
int n;
struct posix_user_ace_state aces[];
};
/*
* While processing the NFSv4 ACE, this maintains the partial permissions
* calculated so far: */
struct posix_acl_state {
int empty;
struct posix_ace_state owner;
struct posix_ace_state group;
struct posix_ace_state other;
struct posix_ace_state everyone;
struct posix_ace_state mask; /* Deny unused in this case */
struct posix_ace_state_array *users;
struct posix_ace_state_array *groups;
};
static int
init_state(struct posix_acl_state *state, int cnt)
{
int alloc;
memset(state, 0, sizeof(struct posix_acl_state));
state->empty = 1;
/*
* In the worst case, each individual acl could be for a distinct
* named user or group, but we don't know which, so we allocate
* enough space for either:
*/
alloc = sizeof(struct posix_ace_state_array)
+ cnt*sizeof(struct posix_user_ace_state);
state->users = kzalloc(alloc, GFP_KERNEL);
if (!state->users)
return -ENOMEM;
state->groups = kzalloc(alloc, GFP_KERNEL);
if (!state->groups) {
kfree(state->users);
return -ENOMEM;
}
return 0;
}
static void
free_state(struct posix_acl_state *state) {
kfree(state->users);
kfree(state->groups);
}
static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
{
state->mask.allow |= astate->allow;
}
static struct posix_acl *
posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
{
struct posix_acl_entry *pace;
struct posix_acl *pacl;
int nace;
int i;
/*
* ACLs with no ACEs are treated differently in the inheritable
* and effective cases: when there are no inheritable ACEs,
* calls ->set_acl with a NULL ACL structure.
*/
if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT))
return NULL;
/*
* When there are no effective ACEs, the following will end
* up setting a 3-element effective posix ACL with all
* permissions zero.
*/
if (!state->users->n && !state->groups->n)
nace = 3;
else /* Note we also include a MASK ACE in this case: */
nace = 4 + state->users->n + state->groups->n;
pacl = posix_acl_alloc(nace, GFP_KERNEL);
if (!pacl)
return ERR_PTR(-ENOMEM);
pace = pacl->a_entries;
pace->e_tag = ACL_USER_OBJ;
low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
for (i=0; i < state->users->n; i++) {
pace++;
pace->e_tag = ACL_USER;
low_mode_from_nfs4(state->users->aces[i].perms.allow,
&pace->e_perm, flags);
pace->e_uid = state->users->aces[i].uid;
add_to_mask(state, &state->users->aces[i].perms);
}
pace++;
pace->e_tag = ACL_GROUP_OBJ;
low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
add_to_mask(state, &state->group);
for (i=0; i < state->groups->n; i++) {
pace++;
pace->e_tag = ACL_GROUP;
low_mode_from_nfs4(state->groups->aces[i].perms.allow,
&pace->e_perm, flags);
pace->e_gid = state->groups->aces[i].gid;
add_to_mask(state, &state->groups->aces[i].perms);
}
if (state->users->n || state->groups->n) {
pace++;
pace->e_tag = ACL_MASK;
low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
}
pace++;
pace->e_tag = ACL_OTHER;
low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
return pacl;
}
static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
{
/* Allow all bits in the mask not already denied: */
astate->allow |= mask & ~astate->deny;
}
static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
{
/* Deny all bits in the mask not already allowed: */
astate->deny |= mask & ~astate->allow;
}
static int find_uid(struct posix_acl_state *state, kuid_t uid)
{
struct posix_ace_state_array *a = state->users;
int i;
for (i = 0; i < a->n; i++)
if (uid_eq(a->aces[i].uid, uid))
return i;
/* Not found: */
a->n++;
a->aces[i].uid = uid;
a->aces[i].perms.allow = state->everyone.allow;
a->aces[i].perms.deny = state->everyone.deny;
return i;
}
static int find_gid(struct posix_acl_state *state, kgid_t gid)
{
struct posix_ace_state_array *a = state->groups;
int i;
for (i = 0; i < a->n; i++)
if (gid_eq(a->aces[i].gid, gid))
return i;
/* Not found: */
a->n++;
a->aces[i].gid = gid;
a->aces[i].perms.allow = state->everyone.allow;
a->aces[i].perms.deny = state->everyone.deny;
return i;
}
static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
{
int i;
for (i=0; i < a->n; i++)
deny_bits(&a->aces[i].perms, mask);
}
static void allow_bits_array(struct posix_ace_state_array *a, u32 mask)
{
int i;
for (i=0; i < a->n; i++)
allow_bits(&a->aces[i].perms, mask);
}
static void process_one_v4_ace(struct posix_acl_state *state,
struct nfs4_ace *ace)
{
u32 mask = ace->access_mask;
int i;
state->empty = 0;
switch (ace2type(ace)) {
case ACL_USER_OBJ:
if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
allow_bits(&state->owner, mask);
} else {
deny_bits(&state->owner, mask);
}
break;
case ACL_USER:
i = find_uid(state, ace->who_uid);
if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
allow_bits(&state->users->aces[i].perms, mask);
} else {
deny_bits(&state->users->aces[i].perms, mask);
mask = state->users->aces[i].perms.deny;
deny_bits(&state->owner, mask);
}
break;
case ACL_GROUP_OBJ:
if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
allow_bits(&state->group, mask);
} else {
deny_bits(&state->group, mask);
mask = state->group.deny;
deny_bits(&state->owner, mask);
deny_bits(&state->everyone, mask);
deny_bits_array(state->users, mask);
deny_bits_array(state->groups, mask);
}
break;
case ACL_GROUP:
i = find_gid(state, ace->who_gid);
if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
allow_bits(&state->groups->aces[i].perms, mask);
} else {
deny_bits(&state->groups->aces[i].perms, mask);
mask = state->groups->aces[i].perms.deny;
deny_bits(&state->owner, mask);
deny_bits(&state->group, mask);
deny_bits(&state->everyone, mask);
deny_bits_array(state->users, mask);
deny_bits_array(state->groups, mask);
}
break;
case ACL_OTHER:
if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
allow_bits(&state->owner, mask);
allow_bits(&state->group, mask);
allow_bits(&state->other, mask);
allow_bits(&state->everyone, mask);
allow_bits_array(state->users, mask);
allow_bits_array(state->groups, mask);
} else {
deny_bits(&state->owner, mask);
deny_bits(&state->group, mask);
deny_bits(&state->other, mask);
deny_bits(&state->everyone, mask);
deny_bits_array(state->users, mask);
deny_bits_array(state->groups, mask);
}
}
}
static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
struct posix_acl **pacl, struct posix_acl **dpacl,
unsigned int flags)
{
struct posix_acl_state effective_acl_state, default_acl_state;
struct nfs4_ace *ace;
int ret;
ret = init_state(&effective_acl_state, acl->naces);
if (ret)
return ret;
ret = init_state(&default_acl_state, acl->naces);
if (ret)
goto out_estate;
ret = -EINVAL;
for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
goto out_dstate;
if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
goto out_dstate;
if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) {
process_one_v4_ace(&effective_acl_state, ace);
continue;
}
if (!(flags & NFS4_ACL_DIR))
goto out_dstate;
/*
* Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT
* is set, we're effectively turning on the other. That's OK,
* according to rfc 3530.
*/
process_one_v4_ace(&default_acl_state, ace);
if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
process_one_v4_ace(&effective_acl_state, ace);
}
*pacl = posix_state_to_acl(&effective_acl_state, flags);
if (IS_ERR(*pacl)) {
ret = PTR_ERR(*pacl);
*pacl = NULL;
goto out_dstate;
}
*dpacl = posix_state_to_acl(&default_acl_state,
flags | NFS4_ACL_TYPE_DEFAULT);
if (IS_ERR(*dpacl)) {
ret = PTR_ERR(*dpacl);
*dpacl = NULL;
posix_acl_release(*pacl);
*pacl = NULL;
goto out_dstate;
}
sort_pacl(*pacl);
sort_pacl(*dpacl);
ret = 0;
out_dstate:
free_state(&default_acl_state);
out_estate:
free_state(&effective_acl_state);
return ret;
}
__be32 nfsd4_acl_to_attr(enum nfs_ftype4 type, struct nfs4_acl *acl,
struct nfsd_attrs *attr)
{
int host_error;
unsigned int flags = 0;
if (!acl)
return nfs_ok;
if (type == NF4DIR)
flags = NFS4_ACL_DIR;
host_error = nfs4_acl_nfsv4_to_posix(acl, &attr->na_pacl,
&attr->na_dpacl, flags);
if (host_error == -EINVAL)
return nfserr_attrnotsupp;
else
return nfserrno(host_error);
}
static short
ace2type(struct nfs4_ace *ace)
{
switch (ace->whotype) {
case NFS4_ACL_WHO_NAMED:
return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
ACL_GROUP : ACL_USER);
case NFS4_ACL_WHO_OWNER:
return ACL_USER_OBJ;
case NFS4_ACL_WHO_GROUP:
return ACL_GROUP_OBJ;
case NFS4_ACL_WHO_EVERYONE:
return ACL_OTHER;
}
BUG();
return -1;
}
/*
* return the size of the struct nfs4_acl required to represent an acl
* with @entries entries.
*/
int nfs4_acl_bytes(int entries)
{
return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace);
}
static struct {
char *string;
int stringlen;
int type;
} s2t_map[] = {
{
.string = "OWNER@",
.stringlen = sizeof("OWNER@") - 1,
.type = NFS4_ACL_WHO_OWNER,
},
{
.string = "GROUP@",
.stringlen = sizeof("GROUP@") - 1,
.type = NFS4_ACL_WHO_GROUP,
},
{
.string = "EVERYONE@",
.stringlen = sizeof("EVERYONE@") - 1,
.type = NFS4_ACL_WHO_EVERYONE,
},
};
int
nfs4_acl_get_whotype(char *p, u32 len)
{
int i;
for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
if (s2t_map[i].stringlen == len &&
0 == memcmp(s2t_map[i].string, p, len))
return s2t_map[i].type;
}
return NFS4_ACL_WHO_NAMED;
}
__be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who)
{
__be32 *p;
int i;
for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
if (s2t_map[i].type != who)
continue;
p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4);
if (!p)
return nfserr_resource;
p = xdr_encode_opaque(p, s2t_map[i].string,
s2t_map[i].stringlen);
return 0;
}
WARN_ON_ONCE(1);
return nfserr_serverfault;
}