linux/fs/nfsd/nfs4acl.c
Kinglong Mee aa07c713ec NFSD: Call ->set_acl with a NULL ACL structure if no entries
After setting ACL for directory, I got two problems that caused
by the cached zero-length default posix acl.

This patch make sure nfsd4_set_nfs4_acl calls ->set_acl
with a NULL ACL structure if there are no entries.

Thanks for Christoph Hellwig's advice.

First problem:
............ hang ...........

Second problem:
[ 1610.167668] ------------[ cut here ]------------
[ 1610.168320] kernel BUG at /root/nfs/linux/fs/nfsd/nfs4acl.c:239!
[ 1610.168320] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 1610.168320] Modules linked in: nfsv4(OE) nfs(OE) nfsd(OE)
rpcsec_gss_krb5 fscache ip6t_rpfilter ip6t_REJECT cfg80211 xt_conntrack
rfkill ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables
ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6
ip6table_mangle ip6table_security ip6table_raw ip6table_filter
ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4
nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw
auth_rpcgss nfs_acl snd_intel8x0 ppdev lockd snd_ac97_codec ac97_bus
snd_pcm snd_timer e1000 pcspkr parport_pc snd parport serio_raw joydev
i2c_piix4 sunrpc(OE) microcode soundcore i2c_core ata_generic pata_acpi
[last unloaded: nfsd]
[ 1610.168320] CPU: 0 PID: 27397 Comm: nfsd Tainted: G           OE
3.15.0-rc1+ #15
[ 1610.168320] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS
VirtualBox 12/01/2006
[ 1610.168320] task: ffff88005ab653d0 ti: ffff88005a944000 task.ti:
ffff88005a944000
[ 1610.168320] RIP: 0010:[<ffffffffa034d5ed>]  [<ffffffffa034d5ed>]
_posix_to_nfsv4_one+0x3cd/0x3d0 [nfsd]
[ 1610.168320] RSP: 0018:ffff88005a945b00  EFLAGS: 00010293
[ 1610.168320] RAX: 0000000000000001 RBX: ffff88006700bac0 RCX:
0000000000000000
[ 1610.168320] RDX: 0000000000000000 RSI: ffff880067c83f00 RDI:
ffff880068233300
[ 1610.168320] RBP: ffff88005a945b48 R08: ffffffff81c64830 R09:
0000000000000000
[ 1610.168320] R10: ffff88004ea85be0 R11: 000000000000f475 R12:
ffff880068233300
[ 1610.168320] R13: 0000000000000003 R14: 0000000000000002 R15:
ffff880068233300
[ 1610.168320] FS:  0000000000000000(0000) GS:ffff880077800000(0000)
knlGS:0000000000000000
[ 1610.168320] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1610.168320] CR2: 00007f5bcbd3b0b9 CR3: 0000000001c0f000 CR4:
00000000000006f0
[ 1610.168320] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 1610.168320] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[ 1610.168320] Stack:
[ 1610.168320]  ffffffff00000000 0000000b67c83500 000000076700bac0
0000000000000000
[ 1610.168320]  ffff88006700bac0 ffff880068233300 ffff88005a945c08
0000000000000002
[ 1610.168320]  0000000000000000 ffff88005a945b88 ffffffffa034e2d5
000000065a945b68
[ 1610.168320] Call Trace:
[ 1610.168320]  [<ffffffffa034e2d5>] nfsd4_get_nfs4_acl+0x95/0x150 [nfsd]
[ 1610.168320]  [<ffffffffa03400d6>] nfsd4_encode_fattr+0x646/0x1e70 [nfsd]
[ 1610.168320]  [<ffffffff816a6e6e>] ? kmemleak_alloc+0x4e/0xb0
[ 1610.168320]  [<ffffffffa0327962>] ?
nfsd_setuser_and_check_port+0x52/0x80 [nfsd]
[ 1610.168320]  [<ffffffff812cd4bb>] ? selinux_cred_prepare+0x1b/0x30
[ 1610.168320]  [<ffffffffa0341caa>] nfsd4_encode_getattr+0x5a/0x60 [nfsd]
[ 1610.168320]  [<ffffffffa0341e07>] nfsd4_encode_operation+0x67/0x110
[nfsd]
[ 1610.168320]  [<ffffffffa033844d>] nfsd4_proc_compound+0x21d/0x810 [nfsd]
[ 1610.168320]  [<ffffffffa0324d9b>] nfsd_dispatch+0xbb/0x200 [nfsd]
[ 1610.168320]  [<ffffffffa00850cd>] svc_process_common+0x46d/0x6d0 [sunrpc]
[ 1610.168320]  [<ffffffffa0085433>] svc_process+0x103/0x170 [sunrpc]
[ 1610.168320]  [<ffffffffa032472f>] nfsd+0xbf/0x130 [nfsd]
[ 1610.168320]  [<ffffffffa0324670>] ? nfsd_destroy+0x80/0x80 [nfsd]
[ 1610.168320]  [<ffffffff810a5202>] kthread+0xd2/0xf0
[ 1610.168320]  [<ffffffff810a5130>] ? insert_kthread_work+0x40/0x40
[ 1610.168320]  [<ffffffff816c1ebc>] ret_from_fork+0x7c/0xb0
[ 1610.168320]  [<ffffffff810a5130>] ? insert_kthread_work+0x40/0x40
[ 1610.168320] Code: 78 02 e9 e7 fc ff ff 31 c0 31 d2 31 c9 66 89 45 ce
41 8b 04 24 66 89 55 d0 66 89 4d d2 48 8d 04 80 49 8d 5c 84 04 e9 37 fd
ff ff <0f> 0b 90 0f 1f 44 00 00 55 8b 56 08 c7 07 00 00 00 00 8b 46 0c
[ 1610.168320] RIP  [<ffffffffa034d5ed>] _posix_to_nfsv4_one+0x3cd/0x3d0
[nfsd]
[ 1610.168320]  RSP <ffff88005a945b00>
[ 1610.257313] ---[ end trace 838254e3e352285b ]---

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-08 12:42:21 -04:00

942 lines
24 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/slab.h>
#include <linux/nfs_fs.h>
#include <linux/export.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)
/* 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)
#define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
| NFS4_ACE_INHERIT_ONLY_ACE \
| 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_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 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 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 = dentry->d_inode;
int error = 0;
struct posix_acl *pacl = NULL, *dpacl = NULL;
unsigned int flags = 0;
int size = 0;
pacl = get_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_acl(inode, ACL_TYPE_DEFAULT);
if (dpacl)
size += 2 * dpacl->a_count;
}
*acl = nfs4_acl_new(size);
if (*acl == NULL) {
error = -ENOMEM;
goto out;
}
_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(pacl);
posix_acl_release(dpacl);
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;
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 (pace_gt(&pacl->a_entries[i],
&pacl->a_entries[i+1])) {
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;
/* 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 no 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;
}
/*
* 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;
/*
* 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;
error = check_deny(state->owner.deny, 1);
if (error)
goto out_err;
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;
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_uid = 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);
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_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;
error = check_deny(state->other.deny, 0);
if (error)
goto out_err;
low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
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, 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_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
struct nfs4_acl *acl)
{
__be32 error;
int host_error;
struct dentry *dentry;
struct inode *inode;
struct posix_acl *pacl = NULL, *dpacl = NULL;
unsigned int flags = 0;
/* Get inode */
error = fh_verify(rqstp, fhp, 0, NFSD_MAY_SATTR);
if (error)
return error;
dentry = fhp->fh_dentry;
inode = dentry->d_inode;
if (!inode->i_op->set_acl || !IS_POSIXACL(inode))
return nfserr_attrnotsupp;
if (S_ISDIR(inode->i_mode))
flags = NFS4_ACL_DIR;
host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
if (host_error == -EINVAL)
return nfserr_attrnotsupp;
if (host_error < 0)
goto out_nfserr;
host_error = inode->i_op->set_acl(inode, pacl, ACL_TYPE_ACCESS);
if (host_error < 0)
goto out_release;
if (S_ISDIR(inode->i_mode)) {
host_error = inode->i_op->set_acl(inode, dpacl,
ACL_TYPE_DEFAULT);
}
out_release:
posix_acl_release(pacl);
posix_acl_release(dpacl);
out_nfserr:
if (host_error == -EOPNOTSUPP)
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;
}
struct nfs4_acl *
nfs4_acl_new(int n)
{
struct nfs4_acl *acl;
acl = kmalloc(sizeof(*acl) + n*sizeof(struct nfs4_ace), GFP_KERNEL);
if (acl == NULL)
return NULL;
acl->naces = 0;
return acl;
}
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(int who, __be32 **p, int *len)
{
int i;
int bytes;
for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
if (s2t_map[i].type != who)
continue;
bytes = 4 + (XDR_QUADLEN(s2t_map[i].stringlen) << 2);
if (bytes > *len)
return nfserr_resource;
*p = xdr_encode_opaque(*p, s2t_map[i].string,
s2t_map[i].stringlen);
*len -= bytes;
return 0;
}
WARN_ON_ONCE(1);
return -1;
}