99 lines
2.3 KiB
C
99 lines
2.3 KiB
C
/*
|
|
* linux/fs/xattr_acl.c
|
|
*
|
|
* Almost all from linux/fs/ext2/acl.c:
|
|
* Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/posix_acl_xattr.h>
|
|
#include <linux/gfp.h>
|
|
|
|
|
|
/*
|
|
* Convert from extended attribute to in-memory representation.
|
|
*/
|
|
struct posix_acl *
|
|
posix_acl_from_xattr(const void *value, size_t size)
|
|
{
|
|
posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
|
|
posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
|
|
int count;
|
|
struct posix_acl *acl;
|
|
struct posix_acl_entry *acl_e;
|
|
|
|
if (!value)
|
|
return NULL;
|
|
if (size < sizeof(posix_acl_xattr_header))
|
|
return ERR_PTR(-EINVAL);
|
|
if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
|
|
return ERR_PTR(-EOPNOTSUPP);
|
|
|
|
count = posix_acl_xattr_count(size);
|
|
if (count < 0)
|
|
return ERR_PTR(-EINVAL);
|
|
if (count == 0)
|
|
return NULL;
|
|
|
|
acl = posix_acl_alloc(count, GFP_NOFS);
|
|
if (!acl)
|
|
return ERR_PTR(-ENOMEM);
|
|
acl_e = acl->a_entries;
|
|
|
|
for (end = entry + count; entry != end; acl_e++, entry++) {
|
|
acl_e->e_tag = le16_to_cpu(entry->e_tag);
|
|
acl_e->e_perm = le16_to_cpu(entry->e_perm);
|
|
|
|
switch(acl_e->e_tag) {
|
|
case ACL_USER_OBJ:
|
|
case ACL_GROUP_OBJ:
|
|
case ACL_MASK:
|
|
case ACL_OTHER:
|
|
acl_e->e_id = ACL_UNDEFINED_ID;
|
|
break;
|
|
|
|
case ACL_USER:
|
|
case ACL_GROUP:
|
|
acl_e->e_id = le32_to_cpu(entry->e_id);
|
|
break;
|
|
|
|
default:
|
|
goto fail;
|
|
}
|
|
}
|
|
return acl;
|
|
|
|
fail:
|
|
posix_acl_release(acl);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
EXPORT_SYMBOL (posix_acl_from_xattr);
|
|
|
|
/*
|
|
* Convert from in-memory to extended attribute representation.
|
|
*/
|
|
int
|
|
posix_acl_to_xattr(const struct posix_acl *acl, void *buffer, size_t size)
|
|
{
|
|
posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer;
|
|
posix_acl_xattr_entry *ext_entry = ext_acl->a_entries;
|
|
int real_size, n;
|
|
|
|
real_size = posix_acl_xattr_size(acl->a_count);
|
|
if (!buffer)
|
|
return real_size;
|
|
if (real_size > size)
|
|
return -ERANGE;
|
|
|
|
ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
|
|
|
|
for (n=0; n < acl->a_count; n++, ext_entry++) {
|
|
ext_entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
|
|
ext_entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
|
|
ext_entry->e_id = cpu_to_le32(acl->a_entries[n].e_id);
|
|
}
|
|
return real_size;
|
|
}
|
|
EXPORT_SYMBOL (posix_acl_to_xattr);
|