linux/fs/nfsd/nfs4acl.c
J.Bruce Fields b66285cee3 [PATCH] knfsd: nfsd4: acls: fix handling of zero-length acls
It is legal to have zero-length NFSv4 acls; they just deny everything.

Also, nfs4_acl_nfsv4_to_posix will always return with pacl and dpacl set on
success, so the caller doesn't need to check this.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04 07:55:20 -07:00

872 lines
22 KiB
C

/*
* fs/nfs4acl/acl.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/string.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/nfs_fs.h>
#include <linux/posix_acl.h>
#include <linux/nfs4.h>
#include <linux/nfs4_acl.h>
/* 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)
/* We don't support these bits; insist they be neither allowed nor denied */
#define NFS4_MASK_UNSUPP (NFS4_ACE_DELETE | NFS4_ACE_WRITE_OWNER \
| NFS4_ACE_READ_NAMED_ATTRS | NFS4_ACE_WRITE_NAMED_ATTRS)
/* flags used to simulate posix default ACLs */
#define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
| NFS4_ACE_DIRECTORY_INHERIT_ACE | NFS4_ACE_INHERIT_ONLY_ACE)
#define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS | NFS4_ACE_IDENTIFIER_GROUP)
#define MASK_EQUAL(mask1, mask2) \
( ((mask1) & NFS4_ACE_MASK_ALL) == ((mask2) & NFS4_ACE_MASK_ALL) )
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(u32 allow_mask, unsigned int flags)
{
u32 ret = ~allow_mask & ~NFS4_MASK_UNSUPP;
if (!(flags & NFS4_ACL_DIR))
ret &= ~NFS4_ACE_DELETE_CHILD;
return ret;
}
/* 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 espect 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;
}
struct ace_container {
struct nfs4_ace *ace;
struct list_head ace_l;
};
static short ace2type(struct nfs4_ace *);
static int _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *, unsigned int);
static struct posix_acl *_nfsv4_to_posix_one(struct nfs4_acl *, unsigned int);
int nfs4_acl_add_ace(struct nfs4_acl *, u32, u32, u32, int, uid_t);
static int nfs4_acl_split(struct nfs4_acl *, struct nfs4_acl *);
struct nfs4_acl *
nfs4_acl_posix_to_nfsv4(struct posix_acl *pacl, struct posix_acl *dpacl,
unsigned int flags)
{
struct nfs4_acl *acl;
int error = -EINVAL;
if ((pacl != NULL &&
(posix_acl_valid(pacl) < 0 || pacl->a_count == 0)) ||
(dpacl != NULL &&
(posix_acl_valid(dpacl) < 0 || dpacl->a_count == 0)))
goto out_err;
acl = nfs4_acl_new();
if (acl == NULL) {
error = -ENOMEM;
goto out_err;
}
if (pacl != NULL) {
error = _posix_to_nfsv4_one(pacl, acl,
flags & ~NFS4_ACL_TYPE_DEFAULT);
if (error < 0)
goto out_acl;
}
if (dpacl != NULL) {
error = _posix_to_nfsv4_one(dpacl, acl,
flags | NFS4_ACL_TYPE_DEFAULT);
if (error < 0)
goto out_acl;
}
return acl;
out_acl:
nfs4_acl_free(acl);
out_err:
acl = ERR_PTR(error);
return acl;
}
static int
nfs4_acl_add_pair(struct nfs4_acl *acl, int eflag, u32 mask, int whotype,
uid_t owner, unsigned int flags)
{
int error;
error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE,
eflag, mask, whotype, owner);
if (error < 0)
return error;
error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
eflag, deny_mask(mask, flags), whotype, owner);
return error;
}
/* We assume the acl has been verified with posix_acl_valid. */
static int
_posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
unsigned int flags)
{
struct posix_acl_entry *pa, *pe, *group_owner_entry;
int error = -EINVAL;
u32 mask, mask_mask;
int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
NFS4_INHERITANCE_FLAGS : 0);
BUG_ON(pacl->a_count < 3);
pe = pacl->a_entries + pacl->a_count;
pa = pe - 2; /* if mask entry exists, it's second from the last. */
if (pa->e_tag == ACL_MASK)
mask_mask = deny_mask(mask_from_posix(pa->e_perm, flags), flags);
else
mask_mask = 0;
pa = pacl->a_entries;
BUG_ON(pa->e_tag != ACL_USER_OBJ);
mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
error = nfs4_acl_add_pair(acl, eflag, mask, NFS4_ACL_WHO_OWNER, 0, flags);
if (error < 0)
goto out;
pa++;
while (pa->e_tag == ACL_USER) {
mask = mask_from_posix(pa->e_perm, flags);
error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
eflag, mask_mask, NFS4_ACL_WHO_NAMED, pa->e_id);
if (error < 0)
goto out;
error = nfs4_acl_add_pair(acl, eflag, mask,
NFS4_ACL_WHO_NAMED, pa->e_id, flags);
if (error < 0)
goto out;
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 */
if (pacl->a_count > 3) {
BUG_ON(pa->e_tag != ACL_GROUP_OBJ);
error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
NFS4_ACE_IDENTIFIER_GROUP | eflag, mask_mask,
NFS4_ACL_WHO_GROUP, 0);
if (error < 0)
goto out;
}
group_owner_entry = pa;
mask = mask_from_posix(pa->e_perm, flags);
error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE,
NFS4_ACE_IDENTIFIER_GROUP | eflag, mask,
NFS4_ACL_WHO_GROUP, 0);
if (error < 0)
goto out;
pa++;
while (pa->e_tag == ACL_GROUP) {
mask = mask_from_posix(pa->e_perm, flags);
error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
NFS4_ACE_IDENTIFIER_GROUP | eflag, mask_mask,
NFS4_ACL_WHO_NAMED, pa->e_id);
if (error < 0)
goto out;
error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE,
NFS4_ACE_IDENTIFIER_GROUP | eflag, mask,
NFS4_ACL_WHO_NAMED, pa->e_id);
if (error < 0)
goto out;
pa++;
}
/* deny ACEs */
pa = group_owner_entry;
mask = mask_from_posix(pa->e_perm, flags);
error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
NFS4_ACE_IDENTIFIER_GROUP | eflag,
deny_mask(mask, flags), NFS4_ACL_WHO_GROUP, 0);
if (error < 0)
goto out;
pa++;
while (pa->e_tag == ACL_GROUP) {
mask = mask_from_posix(pa->e_perm, flags);
error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
NFS4_ACE_IDENTIFIER_GROUP | eflag,
deny_mask(mask, flags), NFS4_ACL_WHO_NAMED, pa->e_id);
if (error < 0)
goto out;
pa++;
}
if (pa->e_tag == ACL_MASK)
pa++;
BUG_ON(pa->e_tag != ACL_OTHER);
mask = mask_from_posix(pa->e_perm, flags);
error = nfs4_acl_add_pair(acl, eflag, mask, NFS4_ACL_WHO_EVERYONE, 0, flags);
out:
return error;
}
static void
sort_pacl_range(struct posix_acl *pacl, int start, int end) {
int sorted = 0, i;
struct posix_acl_entry tmp;
/* 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 (pacl->a_entries[i].e_id
> pacl->a_entries[i+1].e_id) {
sorted = 0;
tmp = pacl->a_entries[i];
pacl->a_entries[i] = pacl->a_entries[i+1];
pacl->a_entries[i+1] = tmp;
}
}
}
}
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;
if (pacl->a_count <= 4)
return; /* no users or groups */
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;
}
int
nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, struct posix_acl **pacl,
struct posix_acl **dpacl, unsigned int flags)
{
struct nfs4_acl *dacl;
int error = -ENOMEM;
*pacl = NULL;
*dpacl = NULL;
dacl = nfs4_acl_new();
if (dacl == NULL)
goto out;
error = nfs4_acl_split(acl, dacl);
if (error)
goto out_acl;
*pacl = _nfsv4_to_posix_one(acl, flags);
if (IS_ERR(*pacl)) {
error = PTR_ERR(*pacl);
*pacl = NULL;
goto out_acl;
}
*dpacl = _nfsv4_to_posix_one(dacl, flags);
if (IS_ERR(*dpacl)) {
error = PTR_ERR(*dpacl);
*dpacl = NULL;
}
out_acl:
if (error) {
posix_acl_release(*pacl);
*pacl = NULL;
}
nfs4_acl_free(dacl);
out:
return error;
}
/*
* 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 {
uid_t uid;
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 {
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));
/*
* In the worst case, each individual acl could be for a distinct
* named user or group, but we don't no which, so we allocate
* enough space for either:
*/
alloc = sizeof(struct posix_ace_state_array)
+ cnt*sizeof(struct posix_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;
}
/*
* Certain bits (SYNCHRONIZE, DELETE, WRITE_OWNER, READ/WRITE_NAMED_ATTRS,
* READ_ATTRIBUTES, READ_ACL) are currently unenforceable and don't translate
* to traditional read/write/execute permissions.
*
* It's problematic to reject acls that use certain mode bits, because it
* places the burden on users to learn the rules about which bits one
* particular server sets, without giving the user a lot of help--we return an
* error that could mean any number of different things. To make matters
* worse, the problematic bits might be introduced by some application that's
* automatically mapping from some other acl model.
*
* So wherever possible we accept anything, possibly erring on the side of
* denying more permissions than necessary.
*
* However we do reject *explicit* DENY's of a few bits representing
* permissions we could never deny:
*/
static inline int check_deny(u32 mask, int isowner)
{
if (mask & (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL))
return -EINVAL;
if (!isowner)
return 0;
if (mask & (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL))
return -EINVAL;
return 0;
}
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, error = 0;
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;
error = check_deny(state->owner.deny, 1);
if (error)
goto out_err;
low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
pace->e_id = ACL_UNDEFINED_ID;
for (i=0; i < state->users->n; i++) {
pace++;
pace->e_tag = ACL_USER;
error = check_deny(state->users->aces[i].perms.deny, 0);
if (error)
goto out_err;
low_mode_from_nfs4(state->users->aces[i].perms.allow,
&pace->e_perm, flags);
pace->e_id = state->users->aces[i].uid;
add_to_mask(state, &state->users->aces[i].perms);
}
pace++;
pace->e_tag = ACL_GROUP_OBJ;
error = check_deny(state->group.deny, 0);
if (error)
goto out_err;
low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
pace->e_id = ACL_UNDEFINED_ID;
add_to_mask(state, &state->group);
for (i=0; i < state->groups->n; i++) {
pace++;
pace->e_tag = ACL_GROUP;
error = check_deny(state->groups->aces[i].perms.deny, 0);
if (error)
goto out_err;
low_mode_from_nfs4(state->groups->aces[i].perms.allow,
&pace->e_perm, flags);
pace->e_id = state->groups->aces[i].uid;
add_to_mask(state, &state->groups->aces[i].perms);
}
pace++;
pace->e_tag = ACL_MASK;
low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
pace->e_id = ACL_UNDEFINED_ID;
pace++;
pace->e_tag = ACL_OTHER;
error = check_deny(state->other.deny, 0);
if (error)
goto out_err;
low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
pace->e_id = ACL_UNDEFINED_ID;
return pacl;
out_err:
posix_acl_release(pacl);
return ERR_PTR(error);
}
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, struct posix_ace_state_array *a, uid_t uid)
{
int i;
for (i = 0; i < a->n; i++)
if (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 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;
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, state->users, ace->who);
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_uid(state, state->groups, ace->who);
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 struct posix_acl *
_nfsv4_to_posix_one(struct nfs4_acl *n4acl, unsigned int flags)
{
struct posix_acl_state state;
struct posix_acl *pacl;
struct nfs4_ace *ace;
int ret;
ret = init_state(&state, n4acl->naces);
if (ret)
return ERR_PTR(ret);
list_for_each_entry(ace, &n4acl->ace_head, l_ace)
process_one_v4_ace(&state, ace);
pacl = posix_state_to_acl(&state, flags);
free_state(&state);
if (!IS_ERR(pacl))
sort_pacl(pacl);
return pacl;
}
static int
nfs4_acl_split(struct nfs4_acl *acl, struct nfs4_acl *dacl)
{
struct list_head *h, *n;
struct nfs4_ace *ace;
int error = 0;
list_for_each_safe(h, n, &acl->ace_head) {
ace = list_entry(h, struct nfs4_ace, l_ace);
if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
return -EINVAL;
if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
return -EINVAL;
switch (ace->flag & NFS4_INHERITANCE_FLAGS) {
case 0:
/* Leave this ace in the effective acl: */
continue;
case NFS4_INHERITANCE_FLAGS:
/* Add this ace to the default acl and remove it
* from the effective acl: */
error = nfs4_acl_add_ace(dacl, ace->type, ace->flag,
ace->access_mask, ace->whotype, ace->who);
if (error)
return error;
list_del(h);
kfree(ace);
acl->naces--;
break;
case NFS4_INHERITANCE_FLAGS & ~NFS4_ACE_INHERIT_ONLY_ACE:
/* Add this ace to the default, but leave it in
* the effective acl as well: */
error = nfs4_acl_add_ace(dacl, ace->type, ace->flag,
ace->access_mask, ace->whotype, ace->who);
if (error)
return error;
break;
default:
return -EINVAL;
}
}
return 0;
}
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;
}
EXPORT_SYMBOL(nfs4_acl_posix_to_nfsv4);
EXPORT_SYMBOL(nfs4_acl_nfsv4_to_posix);
struct nfs4_acl *
nfs4_acl_new(void)
{
struct nfs4_acl *acl;
if ((acl = kmalloc(sizeof(*acl), GFP_KERNEL)) == NULL)
return NULL;
acl->naces = 0;
INIT_LIST_HEAD(&acl->ace_head);
return acl;
}
void
nfs4_acl_free(struct nfs4_acl *acl)
{
struct list_head *h;
struct nfs4_ace *ace;
if (!acl)
return;
while (!list_empty(&acl->ace_head)) {
h = acl->ace_head.next;
list_del(h);
ace = list_entry(h, struct nfs4_ace, l_ace);
kfree(ace);
}
kfree(acl);
return;
}
int
nfs4_acl_add_ace(struct nfs4_acl *acl, u32 type, u32 flag, u32 access_mask,
int whotype, uid_t who)
{
struct nfs4_ace *ace;
if ((ace = kmalloc(sizeof(*ace), GFP_KERNEL)) == NULL)
return -ENOMEM;
ace->type = type;
ace->flag = flag;
ace->access_mask = access_mask;
ace->whotype = whotype;
ace->who = who;
list_add_tail(&ace->l_ace, &acl->ace_head);
acl->naces++;
return 0;
}
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;
}
int
nfs4_acl_write_who(int who, char *p)
{
int i;
for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
if (s2t_map[i].type == who) {
memcpy(p, s2t_map[i].string, s2t_map[i].stringlen);
return s2t_map[i].stringlen;
}
}
BUG();
return -1;
}
EXPORT_SYMBOL(nfs4_acl_new);
EXPORT_SYMBOL(nfs4_acl_free);
EXPORT_SYMBOL(nfs4_acl_add_ace);
EXPORT_SYMBOL(nfs4_acl_get_whotype);
EXPORT_SYMBOL(nfs4_acl_write_who);