squashfs: add support for xattr reading
Add support for listxattr and getxattr. Also add xattr definitions. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
This commit is contained in:
Phillip Lougher
Родитель
4b5397dc24
Коммит
f41d207cbe
|
|
@ -5,5 +5,5 @@
|
|||
obj-$(CONFIG_SQUASHFS) += squashfs.o
|
||||
squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
|
||||
squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o
|
||||
squashfs-y += xattr_id.o
|
||||
squashfs-y += xattr.o xattr_id.o
|
||||
|
||||
|
|
|
|||
|
|
@ -46,6 +46,7 @@
|
|||
#define SQUASHFS_NAME_LEN 256
|
||||
|
||||
#define SQUASHFS_INVALID_FRAG (0xffffffffU)
|
||||
#define SQUASHFS_INVALID_XATTR (0xffffffffU)
|
||||
#define SQUASHFS_INVALID_BLK (-1LL)
|
||||
|
||||
/* Filesystem flags */
|
||||
|
|
@ -96,6 +97,13 @@
|
|||
#define SQUASHFS_LFIFO_TYPE 13
|
||||
#define SQUASHFS_LSOCKET_TYPE 14
|
||||
|
||||
/* Xattr types */
|
||||
#define SQUASHFS_XATTR_USER 0
|
||||
#define SQUASHFS_XATTR_TRUSTED 1
|
||||
#define SQUASHFS_XATTR_SECURITY 2
|
||||
#define SQUASHFS_XATTR_VALUE_OOL 256
|
||||
#define SQUASHFS_XATTR_PREFIX_MASK 0xff
|
||||
|
||||
/* Flag whether block is compressed or uncompressed, bit is set if block is
|
||||
* uncompressed */
|
||||
#define SQUASHFS_COMPRESSED_BIT (1 << 15)
|
||||
|
|
@ -395,6 +403,17 @@ struct squashfs_fragment_entry {
|
|||
unsigned int unused;
|
||||
};
|
||||
|
||||
struct squashfs_xattr_entry {
|
||||
__le16 type;
|
||||
__le16 size;
|
||||
char data[0];
|
||||
};
|
||||
|
||||
struct squashfs_xattr_val {
|
||||
__le32 vsize;
|
||||
char value[0];
|
||||
};
|
||||
|
||||
struct squashfs_xattr_id {
|
||||
__le64 xattr;
|
||||
__le32 count;
|
||||
|
|
|
|||
|
|
@ -26,6 +26,9 @@
|
|||
struct squashfs_inode_info {
|
||||
u64 start;
|
||||
int offset;
|
||||
u64 xattr;
|
||||
unsigned int xattr_size;
|
||||
int xattr_count;
|
||||
union {
|
||||
struct {
|
||||
u64 fragment_block;
|
||||
|
|
|
|||
|
|
@ -0,0 +1,319 @@
|
|||
/*
|
||||
* Squashfs - a compressed read only filesystem for Linux
|
||||
*
|
||||
* Copyright (c) 2010
|
||||
* Phillip Lougher <phillip@lougher.demon.co.uk>
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public License
|
||||
* as published by the Free Software Foundation; either version 2,
|
||||
* or (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
||||
*
|
||||
* xattr_id.c
|
||||
*/
|
||||
|
||||
#include <linux/init.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/string.h>
|
||||
#include <linux/fs.h>
|
||||
#include <linux/vfs.h>
|
||||
#include <linux/xattr.h>
|
||||
#include <linux/slab.h>
|
||||
|
||||
#include "squashfs_fs.h"
|
||||
#include "squashfs_fs_sb.h"
|
||||
#include "squashfs_fs_i.h"
|
||||
#include "squashfs.h"
|
||||
|
||||
static inline struct xattr_handler *squashfs_xattr_handler(int);
|
||||
|
||||
ssize_t squashfs_listxattr(struct dentry *d, char *buffer,
|
||||
size_t buffer_size)
|
||||
{
|
||||
struct inode *inode = d->d_inode;
|
||||
struct super_block *sb = inode->i_sb;
|
||||
struct squashfs_sb_info *msblk = sb->s_fs_info;
|
||||
u64 start = SQUASHFS_XATTR_BLK(squashfs_i(inode)->xattr)
|
||||
+ msblk->xattr_table;
|
||||
int offset = SQUASHFS_XATTR_OFFSET(squashfs_i(inode)->xattr);
|
||||
int count = squashfs_i(inode)->xattr_count;
|
||||
size_t rest = buffer_size;
|
||||
int err;
|
||||
|
||||
/* check that the file system has xattrs */
|
||||
if (msblk->xattr_id_table == NULL)
|
||||
return -EOPNOTSUPP;
|
||||
|
||||
/* loop reading each xattr name */
|
||||
while (count--) {
|
||||
struct squashfs_xattr_entry entry;
|
||||
struct squashfs_xattr_val val;
|
||||
struct xattr_handler *handler;
|
||||
int name_size, prefix_size = 0;
|
||||
|
||||
err = squashfs_read_metadata(sb, &entry, &start, &offset,
|
||||
sizeof(entry));
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
|
||||
name_size = le16_to_cpu(entry.size);
|
||||
handler = squashfs_xattr_handler(le16_to_cpu(entry.type));
|
||||
if (handler)
|
||||
prefix_size = handler->list(d, buffer, rest, NULL,
|
||||
name_size, handler->flags);
|
||||
if (prefix_size) {
|
||||
if (buffer) {
|
||||
if (prefix_size + name_size + 1 > rest) {
|
||||
err = -ERANGE;
|
||||
goto failed;
|
||||
}
|
||||
buffer += prefix_size;
|
||||
}
|
||||
err = squashfs_read_metadata(sb, buffer, &start,
|
||||
&offset, name_size);
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
if (buffer) {
|
||||
buffer[name_size] = '\0';
|
||||
buffer += name_size + 1;
|
||||
}
|
||||
rest -= prefix_size + name_size + 1;
|
||||
} else {
|
||||
/* no handler or insuffficient privileges, so skip */
|
||||
err = squashfs_read_metadata(sb, NULL, &start,
|
||||
&offset, name_size);
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
}
|
||||
|
||||
|
||||
/* skip remaining xattr entry */
|
||||
err = squashfs_read_metadata(sb, &val, &start, &offset,
|
||||
sizeof(val));
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
|
||||
err = squashfs_read_metadata(sb, NULL, &start, &offset,
|
||||
le32_to_cpu(val.vsize));
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
}
|
||||
err = buffer_size - rest;
|
||||
|
||||
failed:
|
||||
return err;
|
||||
}
|
||||
|
||||
|
||||
static int squashfs_xattr_get(struct inode *inode, int name_index,
|
||||
const char *name, void *buffer, size_t buffer_size)
|
||||
{
|
||||
struct super_block *sb = inode->i_sb;
|
||||
struct squashfs_sb_info *msblk = sb->s_fs_info;
|
||||
u64 start = SQUASHFS_XATTR_BLK(squashfs_i(inode)->xattr)
|
||||
+ msblk->xattr_table;
|
||||
int offset = SQUASHFS_XATTR_OFFSET(squashfs_i(inode)->xattr);
|
||||
int count = squashfs_i(inode)->xattr_count;
|
||||
int name_len = strlen(name);
|
||||
int err, vsize;
|
||||
char *target = kmalloc(name_len, GFP_KERNEL);
|
||||
|
||||
if (target == NULL)
|
||||
return -ENOMEM;
|
||||
|
||||
/* loop reading each xattr name */
|
||||
for (; count; count--) {
|
||||
struct squashfs_xattr_entry entry;
|
||||
struct squashfs_xattr_val val;
|
||||
int type, prefix, name_size;
|
||||
|
||||
err = squashfs_read_metadata(sb, &entry, &start, &offset,
|
||||
sizeof(entry));
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
|
||||
name_size = le16_to_cpu(entry.size);
|
||||
type = le16_to_cpu(entry.type);
|
||||
prefix = type & SQUASHFS_XATTR_PREFIX_MASK;
|
||||
|
||||
err = squashfs_read_metadata(sb, target, &start, &offset,
|
||||
name_size);
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
|
||||
if (prefix == name_index && name_size == name_len &&
|
||||
strncmp(target, name, name_size) == 0) {
|
||||
/* found xattr */
|
||||
if (type & SQUASHFS_XATTR_VALUE_OOL) {
|
||||
__le64 xattr;
|
||||
/* val is a reference to the real location */
|
||||
err = squashfs_read_metadata(sb, &val, &start,
|
||||
&offset, sizeof(val));
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
err = squashfs_read_metadata(sb, &xattr, &start,
|
||||
&offset, sizeof(xattr));
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
xattr = le64_to_cpu(xattr);
|
||||
start = SQUASHFS_XATTR_BLK(xattr) +
|
||||
msblk->xattr_table;
|
||||
offset = SQUASHFS_XATTR_OFFSET(xattr);
|
||||
}
|
||||
/* read xattr value */
|
||||
err = squashfs_read_metadata(sb, &val, &start, &offset,
|
||||
sizeof(val));
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
|
||||
vsize = le32_to_cpu(val.vsize);
|
||||
if (buffer) {
|
||||
if (vsize > buffer_size) {
|
||||
err = -ERANGE;
|
||||
goto failed;
|
||||
}
|
||||
err = squashfs_read_metadata(sb, buffer, &start,
|
||||
&offset, vsize);
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
/* no match, skip remaining xattr entry */
|
||||
err = squashfs_read_metadata(sb, &val, &start, &offset,
|
||||
sizeof(val));
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
err = squashfs_read_metadata(sb, NULL, &start, &offset,
|
||||
le32_to_cpu(val.vsize));
|
||||
if (err < 0)
|
||||
goto failed;
|
||||
}
|
||||
err = count ? vsize : -ENODATA;
|
||||
|
||||
failed:
|
||||
kfree(target);
|
||||
return err;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* User namespace support
|
||||
*/
|
||||
static size_t squashfs_user_list(struct dentry *d, char *list, size_t list_size,
|
||||
const char *name, size_t name_len, int type)
|
||||
{
|
||||
if (list && XATTR_USER_PREFIX_LEN <= list_size)
|
||||
memcpy(list, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
|
||||
return XATTR_USER_PREFIX_LEN;
|
||||
}
|
||||
|
||||
static int squashfs_user_get(struct dentry *d, const char *name, void *buffer,
|
||||
size_t size, int type)
|
||||
{
|
||||
if (name[0] == '\0')
|
||||
return -EINVAL;
|
||||
|
||||
return squashfs_xattr_get(d->d_inode, SQUASHFS_XATTR_USER, name,
|
||||
buffer, size);
|
||||
}
|
||||
|
||||
struct xattr_handler squashfs_xattr_user_handler = {
|
||||
.prefix = XATTR_USER_PREFIX,
|
||||
.list = squashfs_user_list,
|
||||
.get = squashfs_user_get
|
||||
};
|
||||
|
||||
/*
|
||||
* Trusted namespace support
|
||||
*/
|
||||
static size_t squashfs_trusted_list(struct dentry *d, char *list,
|
||||
size_t list_size, const char *name, size_t name_len, int type)
|
||||
{
|
||||
if (!capable(CAP_SYS_ADMIN))
|
||||
return 0;
|
||||
|
||||
if (list && XATTR_TRUSTED_PREFIX_LEN <= list_size)
|
||||
memcpy(list, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
|
||||
return XATTR_TRUSTED_PREFIX_LEN;
|
||||
}
|
||||
|
||||
static int squashfs_trusted_get(struct dentry *d, const char *name,
|
||||
void *buffer, size_t size, int type)
|
||||
{
|
||||
if (name[0] == '\0')
|
||||
return -EINVAL;
|
||||
|
||||
return squashfs_xattr_get(d->d_inode, SQUASHFS_XATTR_TRUSTED, name,
|
||||
buffer, size);
|
||||
}
|
||||
|
||||
struct xattr_handler squashfs_xattr_trusted_handler = {
|
||||
.prefix = XATTR_TRUSTED_PREFIX,
|
||||
.list = squashfs_trusted_list,
|
||||
.get = squashfs_trusted_get
|
||||
};
|
||||
|
||||
/*
|
||||
* Security namespace support
|
||||
*/
|
||||
static size_t squashfs_security_list(struct dentry *d, char *list,
|
||||
size_t list_size, const char *name, size_t name_len, int type)
|
||||
{
|
||||
if (list && XATTR_SECURITY_PREFIX_LEN <= list_size)
|
||||
memcpy(list, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN);
|
||||
return XATTR_SECURITY_PREFIX_LEN;
|
||||
}
|
||||
|
||||
static int squashfs_security_get(struct dentry *d, const char *name,
|
||||
void *buffer, size_t size, int type)
|
||||
{
|
||||
if (name[0] == '\0')
|
||||
return -EINVAL;
|
||||
|
||||
return squashfs_xattr_get(d->d_inode, SQUASHFS_XATTR_SECURITY, name,
|
||||
buffer, size);
|
||||
}
|
||||
|
||||
struct xattr_handler squashfs_xattr_security_handler = {
|
||||
.prefix = XATTR_SECURITY_PREFIX,
|
||||
.list = squashfs_security_list,
|
||||
.get = squashfs_security_get
|
||||
};
|
||||
|
||||
static inline struct xattr_handler *squashfs_xattr_handler(int type)
|
||||
{
|
||||
if (type & ~(SQUASHFS_XATTR_PREFIX_MASK | SQUASHFS_XATTR_VALUE_OOL))
|
||||
/* ignore unrecognised type */
|
||||
return NULL;
|
||||
|
||||
switch (type & SQUASHFS_XATTR_PREFIX_MASK) {
|
||||
case SQUASHFS_XATTR_USER:
|
||||
return &squashfs_xattr_user_handler;
|
||||
case SQUASHFS_XATTR_TRUSTED:
|
||||
return &squashfs_xattr_trusted_handler;
|
||||
case SQUASHFS_XATTR_SECURITY:
|
||||
return &squashfs_xattr_security_handler;
|
||||
default:
|
||||
/* ignore unrecognised type */
|
||||
return NULL;
|
||||
}
|
||||
}
|
||||
|
||||
struct xattr_handler *squashfs_xattr_handlers[] = {
|
||||
&squashfs_xattr_user_handler,
|
||||
&squashfs_xattr_trusted_handler,
|
||||
&squashfs_xattr_security_handler,
|
||||
NULL
|
||||
};
|
||||
|
||||
Загрузка…
Ссылка в новой задаче