linux/fs/hfsplus/xattr.c
Christian Brauner e65ce2a50c
acl: handle idmapped mounts
The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it possible to handle acls on idmapped
mounts.

The vfs and the filesystems targeted by this first iteration make use of
posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to
translate basic posix access and default permissions such as the
ACL_USER and ACL_GROUP type according to the initial user namespace (or
the superblock's user namespace) to and from the caller's current user
namespace. Adapt these two helpers to handle idmapped mounts whereby we
either map from or into the mount's user namespace depending on in which
direction we're translating.
Similarly, cap_convert_nscap() is used by the vfs to translate user
namespace and non-user namespace aware filesystem capabilities from the
superblock's user namespace to the caller's user namespace. Enable it to
handle idmapped mounts by accounting for the mount's user namespace.

In addition the fileystems targeted in the first iteration of this patch
series make use of the posix_acl_chmod() and, posix_acl_update_mode()
helpers. Both helpers perform permission checks on the target inode. Let
them handle idmapped mounts. These two helpers are called when posix
acls are set by the respective filesystems to handle this case we extend
the ->set() method to take an additional user namespace argument to pass
the mount's user namespace down.

Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:17 +01:00

887 lines
23 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/hfsplus/xattr.c
*
* Vyacheslav Dubeyko <slava@dubeyko.com>
*
* Logic of processing extended attributes
*/
#include "hfsplus_fs.h"
#include <linux/nls.h>
#include "xattr.h"
static int hfsplus_removexattr(struct inode *inode, const char *name);
const struct xattr_handler *hfsplus_xattr_handlers[] = {
&hfsplus_xattr_osx_handler,
&hfsplus_xattr_user_handler,
&hfsplus_xattr_trusted_handler,
&hfsplus_xattr_security_handler,
NULL
};
static int strcmp_xattr_finder_info(const char *name)
{
if (name) {
return strncmp(name, HFSPLUS_XATTR_FINDER_INFO_NAME,
sizeof(HFSPLUS_XATTR_FINDER_INFO_NAME));
}
return -1;
}
static int strcmp_xattr_acl(const char *name)
{
if (name) {
return strncmp(name, HFSPLUS_XATTR_ACL_NAME,
sizeof(HFSPLUS_XATTR_ACL_NAME));
}
return -1;
}
static bool is_known_namespace(const char *name)
{
if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
return false;
return true;
}
static void hfsplus_init_header_node(struct inode *attr_file,
u32 clump_size,
char *buf, u16 node_size)
{
struct hfs_bnode_desc *desc;
struct hfs_btree_header_rec *head;
u16 offset;
__be16 *rec_offsets;
u32 hdr_node_map_rec_bits;
char *bmp;
u32 used_nodes;
u32 used_bmp_bytes;
u64 tmp;
hfs_dbg(ATTR_MOD, "init_hdr_attr_file: clump %u, node_size %u\n",
clump_size, node_size);
/* The end of the node contains list of record offsets */
rec_offsets = (__be16 *)(buf + node_size);
desc = (struct hfs_bnode_desc *)buf;
desc->type = HFS_NODE_HEADER;
desc->num_recs = cpu_to_be16(HFSPLUS_BTREE_HDR_NODE_RECS_COUNT);
offset = sizeof(struct hfs_bnode_desc);
*--rec_offsets = cpu_to_be16(offset);
head = (struct hfs_btree_header_rec *)(buf + offset);
head->node_size = cpu_to_be16(node_size);
tmp = i_size_read(attr_file);
do_div(tmp, node_size);
head->node_count = cpu_to_be32(tmp);
head->free_nodes = cpu_to_be32(be32_to_cpu(head->node_count) - 1);
head->clump_size = cpu_to_be32(clump_size);
head->attributes |= cpu_to_be32(HFS_TREE_BIGKEYS | HFS_TREE_VARIDXKEYS);
head->max_key_len = cpu_to_be16(HFSPLUS_ATTR_KEYLEN - sizeof(u16));
offset += sizeof(struct hfs_btree_header_rec);
*--rec_offsets = cpu_to_be16(offset);
offset += HFSPLUS_BTREE_HDR_USER_BYTES;
*--rec_offsets = cpu_to_be16(offset);
hdr_node_map_rec_bits = 8 * (node_size - offset - (4 * sizeof(u16)));
if (be32_to_cpu(head->node_count) > hdr_node_map_rec_bits) {
u32 map_node_bits;
u32 map_nodes;
desc->next = cpu_to_be32(be32_to_cpu(head->leaf_tail) + 1);
map_node_bits = 8 * (node_size - sizeof(struct hfs_bnode_desc) -
(2 * sizeof(u16)) - 2);
map_nodes = (be32_to_cpu(head->node_count) -
hdr_node_map_rec_bits +
(map_node_bits - 1)) / map_node_bits;
be32_add_cpu(&head->free_nodes, 0 - map_nodes);
}
bmp = buf + offset;
used_nodes =
be32_to_cpu(head->node_count) - be32_to_cpu(head->free_nodes);
used_bmp_bytes = used_nodes / 8;
if (used_bmp_bytes) {
memset(bmp, 0xFF, used_bmp_bytes);
bmp += used_bmp_bytes;
used_nodes %= 8;
}
*bmp = ~(0xFF >> used_nodes);
offset += hdr_node_map_rec_bits / 8;
*--rec_offsets = cpu_to_be16(offset);
}
static int hfsplus_create_attributes_file(struct super_block *sb)
{
int err = 0;
struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
struct inode *attr_file;
struct hfsplus_inode_info *hip;
u32 clump_size;
u16 node_size = HFSPLUS_ATTR_TREE_NODE_SIZE;
char *buf;
int index, written;
struct address_space *mapping;
struct page *page;
int old_state = HFSPLUS_EMPTY_ATTR_TREE;
hfs_dbg(ATTR_MOD, "create_attr_file: ino %d\n", HFSPLUS_ATTR_CNID);
check_attr_tree_state_again:
switch (atomic_read(&sbi->attr_tree_state)) {
case HFSPLUS_EMPTY_ATTR_TREE:
if (old_state != atomic_cmpxchg(&sbi->attr_tree_state,
old_state,
HFSPLUS_CREATING_ATTR_TREE))
goto check_attr_tree_state_again;
break;
case HFSPLUS_CREATING_ATTR_TREE:
/*
* This state means that another thread is in process
* of AttributesFile creation. Theoretically, it is
* possible to be here. But really __setxattr() method
* first of all calls hfs_find_init() for lookup in
* B-tree of CatalogFile. This method locks mutex of
* CatalogFile's B-tree. As a result, if some thread
* is inside AttributedFile creation operation then
* another threads will be waiting unlocking of
* CatalogFile's B-tree's mutex. However, if code will
* change then we will return error code (-EAGAIN) from
* here. Really, it means that first try to set of xattr
* fails with error but second attempt will have success.
*/
return -EAGAIN;
case HFSPLUS_VALID_ATTR_TREE:
return 0;
case HFSPLUS_FAILED_ATTR_TREE:
return -EOPNOTSUPP;
default:
BUG();
}
attr_file = hfsplus_iget(sb, HFSPLUS_ATTR_CNID);
if (IS_ERR(attr_file)) {
pr_err("failed to load attributes file\n");
return PTR_ERR(attr_file);
}
BUG_ON(i_size_read(attr_file) != 0);
hip = HFSPLUS_I(attr_file);
clump_size = hfsplus_calc_btree_clump_size(sb->s_blocksize,
node_size,
sbi->sect_count,
HFSPLUS_ATTR_CNID);
mutex_lock(&hip->extents_lock);
hip->clump_blocks = clump_size >> sbi->alloc_blksz_shift;
mutex_unlock(&hip->extents_lock);
if (sbi->free_blocks <= (hip->clump_blocks << 1)) {
err = -ENOSPC;
goto end_attr_file_creation;
}
while (hip->alloc_blocks < hip->clump_blocks) {
err = hfsplus_file_extend(attr_file, false);
if (unlikely(err)) {
pr_err("failed to extend attributes file\n");
goto end_attr_file_creation;
}
hip->phys_size = attr_file->i_size =
(loff_t)hip->alloc_blocks << sbi->alloc_blksz_shift;
hip->fs_blocks = hip->alloc_blocks << sbi->fs_shift;
inode_set_bytes(attr_file, attr_file->i_size);
}
buf = kzalloc(node_size, GFP_NOFS);
if (!buf) {
pr_err("failed to allocate memory for header node\n");
err = -ENOMEM;
goto end_attr_file_creation;
}
hfsplus_init_header_node(attr_file, clump_size, buf, node_size);
mapping = attr_file->i_mapping;
index = 0;
written = 0;
for (; written < node_size; index++, written += PAGE_SIZE) {
void *kaddr;
page = read_mapping_page(mapping, index, NULL);
if (IS_ERR(page)) {
err = PTR_ERR(page);
goto failed_header_node_init;
}
kaddr = kmap_atomic(page);
memcpy(kaddr, buf + written,
min_t(size_t, PAGE_SIZE, node_size - written));
kunmap_atomic(kaddr);
set_page_dirty(page);
put_page(page);
}
hfsplus_mark_inode_dirty(attr_file, HFSPLUS_I_ATTR_DIRTY);
sbi->attr_tree = hfs_btree_open(sb, HFSPLUS_ATTR_CNID);
if (!sbi->attr_tree)
pr_err("failed to load attributes file\n");
failed_header_node_init:
kfree(buf);
end_attr_file_creation:
iput(attr_file);
if (!err)
atomic_set(&sbi->attr_tree_state, HFSPLUS_VALID_ATTR_TREE);
else if (err == -ENOSPC)
atomic_set(&sbi->attr_tree_state, HFSPLUS_EMPTY_ATTR_TREE);
else
atomic_set(&sbi->attr_tree_state, HFSPLUS_FAILED_ATTR_TREE);
return err;
}
int __hfsplus_setxattr(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
int err = 0;
struct hfs_find_data cat_fd;
hfsplus_cat_entry entry;
u16 cat_entry_flags, cat_entry_type;
u16 folder_finderinfo_len = sizeof(struct DInfo) +
sizeof(struct DXInfo);
u16 file_finderinfo_len = sizeof(struct FInfo) +
sizeof(struct FXInfo);
if ((!S_ISREG(inode->i_mode) &&
!S_ISDIR(inode->i_mode)) ||
HFSPLUS_IS_RSRC(inode))
return -EOPNOTSUPP;
if (value == NULL)
return hfsplus_removexattr(inode, name);
err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &cat_fd);
if (err) {
pr_err("can't init xattr find struct\n");
return err;
}
err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &cat_fd);
if (err) {
pr_err("catalog searching failed\n");
goto end_setxattr;
}
if (!strcmp_xattr_finder_info(name)) {
if (flags & XATTR_CREATE) {
pr_err("xattr exists yet\n");
err = -EOPNOTSUPP;
goto end_setxattr;
}
hfs_bnode_read(cat_fd.bnode, &entry, cat_fd.entryoffset,
sizeof(hfsplus_cat_entry));
if (be16_to_cpu(entry.type) == HFSPLUS_FOLDER) {
if (size == folder_finderinfo_len) {
memcpy(&entry.folder.user_info, value,
folder_finderinfo_len);
hfs_bnode_write(cat_fd.bnode, &entry,
cat_fd.entryoffset,
sizeof(struct hfsplus_cat_folder));
hfsplus_mark_inode_dirty(inode,
HFSPLUS_I_CAT_DIRTY);
} else {
err = -ERANGE;
goto end_setxattr;
}
} else if (be16_to_cpu(entry.type) == HFSPLUS_FILE) {
if (size == file_finderinfo_len) {
memcpy(&entry.file.user_info, value,
file_finderinfo_len);
hfs_bnode_write(cat_fd.bnode, &entry,
cat_fd.entryoffset,
sizeof(struct hfsplus_cat_file));
hfsplus_mark_inode_dirty(inode,
HFSPLUS_I_CAT_DIRTY);
} else {
err = -ERANGE;
goto end_setxattr;
}
} else {
err = -EOPNOTSUPP;
goto end_setxattr;
}
goto end_setxattr;
}
if (!HFSPLUS_SB(inode->i_sb)->attr_tree) {
err = hfsplus_create_attributes_file(inode->i_sb);
if (unlikely(err))
goto end_setxattr;
}
if (hfsplus_attr_exists(inode, name)) {
if (flags & XATTR_CREATE) {
pr_err("xattr exists yet\n");
err = -EOPNOTSUPP;
goto end_setxattr;
}
err = hfsplus_delete_attr(inode, name);
if (err)
goto end_setxattr;
err = hfsplus_create_attr(inode, name, value, size);
if (err)
goto end_setxattr;
} else {
if (flags & XATTR_REPLACE) {
pr_err("cannot replace xattr\n");
err = -EOPNOTSUPP;
goto end_setxattr;
}
err = hfsplus_create_attr(inode, name, value, size);
if (err)
goto end_setxattr;
}
cat_entry_type = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset);
if (cat_entry_type == HFSPLUS_FOLDER) {
cat_entry_flags = hfs_bnode_read_u16(cat_fd.bnode,
cat_fd.entryoffset +
offsetof(struct hfsplus_cat_folder, flags));
cat_entry_flags |= HFSPLUS_XATTR_EXISTS;
if (!strcmp_xattr_acl(name))
cat_entry_flags |= HFSPLUS_ACL_EXISTS;
hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
offsetof(struct hfsplus_cat_folder, flags),
cat_entry_flags);
hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
} else if (cat_entry_type == HFSPLUS_FILE) {
cat_entry_flags = hfs_bnode_read_u16(cat_fd.bnode,
cat_fd.entryoffset +
offsetof(struct hfsplus_cat_file, flags));
cat_entry_flags |= HFSPLUS_XATTR_EXISTS;
if (!strcmp_xattr_acl(name))
cat_entry_flags |= HFSPLUS_ACL_EXISTS;
hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
offsetof(struct hfsplus_cat_file, flags),
cat_entry_flags);
hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
} else {
pr_err("invalid catalog entry type\n");
err = -EIO;
goto end_setxattr;
}
end_setxattr:
hfs_find_exit(&cat_fd);
return err;
}
static int name_len(const char *xattr_name, int xattr_name_len)
{
int len = xattr_name_len + 1;
if (!is_known_namespace(xattr_name))
len += XATTR_MAC_OSX_PREFIX_LEN;
return len;
}
static int copy_name(char *buffer, const char *xattr_name, int name_len)
{
int len = name_len;
int offset = 0;
if (!is_known_namespace(xattr_name)) {
memcpy(buffer, XATTR_MAC_OSX_PREFIX, XATTR_MAC_OSX_PREFIX_LEN);
offset += XATTR_MAC_OSX_PREFIX_LEN;
len += XATTR_MAC_OSX_PREFIX_LEN;
}
strncpy(buffer + offset, xattr_name, name_len);
memset(buffer + offset + name_len, 0, 1);
len += 1;
return len;
}
int hfsplus_setxattr(struct inode *inode, const char *name,
const void *value, size_t size, int flags,
const char *prefix, size_t prefixlen)
{
char *xattr_name;
int res;
xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
GFP_KERNEL);
if (!xattr_name)
return -ENOMEM;
strcpy(xattr_name, prefix);
strcpy(xattr_name + prefixlen, name);
res = __hfsplus_setxattr(inode, xattr_name, value, size, flags);
kfree(xattr_name);
return res;
}
static ssize_t hfsplus_getxattr_finder_info(struct inode *inode,
void *value, size_t size)
{
ssize_t res = 0;
struct hfs_find_data fd;
u16 entry_type;
u16 folder_rec_len = sizeof(struct DInfo) + sizeof(struct DXInfo);
u16 file_rec_len = sizeof(struct FInfo) + sizeof(struct FXInfo);
u16 record_len = max(folder_rec_len, file_rec_len);
u8 folder_finder_info[sizeof(struct DInfo) + sizeof(struct DXInfo)];
u8 file_finder_info[sizeof(struct FInfo) + sizeof(struct FXInfo)];
if (size >= record_len) {
res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
if (res) {
pr_err("can't init xattr find struct\n");
return res;
}
res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
if (res)
goto end_getxattr_finder_info;
entry_type = hfs_bnode_read_u16(fd.bnode, fd.entryoffset);
if (entry_type == HFSPLUS_FOLDER) {
hfs_bnode_read(fd.bnode, folder_finder_info,
fd.entryoffset +
offsetof(struct hfsplus_cat_folder, user_info),
folder_rec_len);
memcpy(value, folder_finder_info, folder_rec_len);
res = folder_rec_len;
} else if (entry_type == HFSPLUS_FILE) {
hfs_bnode_read(fd.bnode, file_finder_info,
fd.entryoffset +
offsetof(struct hfsplus_cat_file, user_info),
file_rec_len);
memcpy(value, file_finder_info, file_rec_len);
res = file_rec_len;
} else {
res = -EOPNOTSUPP;
goto end_getxattr_finder_info;
}
} else
res = size ? -ERANGE : record_len;
end_getxattr_finder_info:
if (size >= record_len)
hfs_find_exit(&fd);
return res;
}
ssize_t __hfsplus_getxattr(struct inode *inode, const char *name,
void *value, size_t size)
{
struct hfs_find_data fd;
hfsplus_attr_entry *entry;
__be32 xattr_record_type;
u32 record_type;
u16 record_length = 0;
ssize_t res = 0;
if ((!S_ISREG(inode->i_mode) &&
!S_ISDIR(inode->i_mode)) ||
HFSPLUS_IS_RSRC(inode))
return -EOPNOTSUPP;
if (!strcmp_xattr_finder_info(name))
return hfsplus_getxattr_finder_info(inode, value, size);
if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
return -EOPNOTSUPP;
entry = hfsplus_alloc_attr_entry();
if (!entry) {
pr_err("can't allocate xattr entry\n");
return -ENOMEM;
}
res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->attr_tree, &fd);
if (res) {
pr_err("can't init xattr find struct\n");
goto failed_getxattr_init;
}
res = hfsplus_find_attr(inode->i_sb, inode->i_ino, name, &fd);
if (res) {
if (res == -ENOENT)
res = -ENODATA;
else
pr_err("xattr searching failed\n");
goto out;
}
hfs_bnode_read(fd.bnode, &xattr_record_type,
fd.entryoffset, sizeof(xattr_record_type));
record_type = be32_to_cpu(xattr_record_type);
if (record_type == HFSPLUS_ATTR_INLINE_DATA) {
record_length = hfs_bnode_read_u16(fd.bnode,
fd.entryoffset +
offsetof(struct hfsplus_attr_inline_data,
length));
if (record_length > HFSPLUS_MAX_INLINE_DATA_SIZE) {
pr_err("invalid xattr record size\n");
res = -EIO;
goto out;
}
} else if (record_type == HFSPLUS_ATTR_FORK_DATA ||
record_type == HFSPLUS_ATTR_EXTENTS) {
pr_err("only inline data xattr are supported\n");
res = -EOPNOTSUPP;
goto out;
} else {
pr_err("invalid xattr record\n");
res = -EIO;
goto out;
}
if (size) {
hfs_bnode_read(fd.bnode, entry, fd.entryoffset,
offsetof(struct hfsplus_attr_inline_data,
raw_bytes) + record_length);
}
if (size >= record_length) {
memcpy(value, entry->inline_data.raw_bytes, record_length);
res = record_length;
} else
res = size ? -ERANGE : record_length;
out:
hfs_find_exit(&fd);
failed_getxattr_init:
hfsplus_destroy_attr_entry(entry);
return res;
}
ssize_t hfsplus_getxattr(struct inode *inode, const char *name,
void *value, size_t size,
const char *prefix, size_t prefixlen)
{
int res;
char *xattr_name;
xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
GFP_KERNEL);
if (!xattr_name)
return -ENOMEM;
strcpy(xattr_name, prefix);
strcpy(xattr_name + prefixlen, name);
res = __hfsplus_getxattr(inode, xattr_name, value, size);
kfree(xattr_name);
return res;
}
static inline int can_list(const char *xattr_name)
{
if (!xattr_name)
return 0;
return strncmp(xattr_name, XATTR_TRUSTED_PREFIX,
XATTR_TRUSTED_PREFIX_LEN) ||
capable(CAP_SYS_ADMIN);
}
static ssize_t hfsplus_listxattr_finder_info(struct dentry *dentry,
char *buffer, size_t size)
{
ssize_t res = 0;
struct inode *inode = d_inode(dentry);
struct hfs_find_data fd;
u16 entry_type;
u8 folder_finder_info[sizeof(struct DInfo) + sizeof(struct DXInfo)];
u8 file_finder_info[sizeof(struct FInfo) + sizeof(struct FXInfo)];
unsigned long len, found_bit;
int xattr_name_len, symbols_count;
res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
if (res) {
pr_err("can't init xattr find struct\n");
return res;
}
res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
if (res)
goto end_listxattr_finder_info;
entry_type = hfs_bnode_read_u16(fd.bnode, fd.entryoffset);
if (entry_type == HFSPLUS_FOLDER) {
len = sizeof(struct DInfo) + sizeof(struct DXInfo);
hfs_bnode_read(fd.bnode, folder_finder_info,
fd.entryoffset +
offsetof(struct hfsplus_cat_folder, user_info),
len);
found_bit = find_first_bit((void *)folder_finder_info, len*8);
} else if (entry_type == HFSPLUS_FILE) {
len = sizeof(struct FInfo) + sizeof(struct FXInfo);
hfs_bnode_read(fd.bnode, file_finder_info,
fd.entryoffset +
offsetof(struct hfsplus_cat_file, user_info),
len);
found_bit = find_first_bit((void *)file_finder_info, len*8);
} else {
res = -EOPNOTSUPP;
goto end_listxattr_finder_info;
}
if (found_bit >= (len*8))
res = 0;
else {
symbols_count = sizeof(HFSPLUS_XATTR_FINDER_INFO_NAME) - 1;
xattr_name_len =
name_len(HFSPLUS_XATTR_FINDER_INFO_NAME, symbols_count);
if (!buffer || !size) {
if (can_list(HFSPLUS_XATTR_FINDER_INFO_NAME))
res = xattr_name_len;
} else if (can_list(HFSPLUS_XATTR_FINDER_INFO_NAME)) {
if (size < xattr_name_len)
res = -ERANGE;
else {
res = copy_name(buffer,
HFSPLUS_XATTR_FINDER_INFO_NAME,
symbols_count);
}
}
}
end_listxattr_finder_info:
hfs_find_exit(&fd);
return res;
}
ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
ssize_t err;
ssize_t res = 0;
struct inode *inode = d_inode(dentry);
struct hfs_find_data fd;
u16 key_len = 0;
struct hfsplus_attr_key attr_key;
char *strbuf;
int xattr_name_len;
if ((!S_ISREG(inode->i_mode) &&
!S_ISDIR(inode->i_mode)) ||
HFSPLUS_IS_RSRC(inode))
return -EOPNOTSUPP;
res = hfsplus_listxattr_finder_info(dentry, buffer, size);
if (res < 0)
return res;
else if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
return (res == 0) ? -EOPNOTSUPP : res;
err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->attr_tree, &fd);
if (err) {
pr_err("can't init xattr find struct\n");
return err;
}
strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN +
XATTR_MAC_OSX_PREFIX_LEN + 1, GFP_KERNEL);
if (!strbuf) {
res = -ENOMEM;
goto out;
}
err = hfsplus_find_attr(inode->i_sb, inode->i_ino, NULL, &fd);
if (err) {
if (err == -ENOENT) {
if (res == 0)
res = -ENODATA;
goto end_listxattr;
} else {
res = err;
goto end_listxattr;
}
}
for (;;) {
key_len = hfs_bnode_read_u16(fd.bnode, fd.keyoffset);
if (key_len == 0 || key_len > fd.tree->max_key_len) {
pr_err("invalid xattr key length: %d\n", key_len);
res = -EIO;
goto end_listxattr;
}
hfs_bnode_read(fd.bnode, &attr_key,
fd.keyoffset, key_len + sizeof(key_len));
if (be32_to_cpu(attr_key.cnid) != inode->i_ino)
goto end_listxattr;
xattr_name_len = NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN;
if (hfsplus_uni2asc(inode->i_sb,
(const struct hfsplus_unistr *)&fd.key->attr.key_name,
strbuf, &xattr_name_len)) {
pr_err("unicode conversion failed\n");
res = -EIO;
goto end_listxattr;
}
if (!buffer || !size) {
if (can_list(strbuf))
res += name_len(strbuf, xattr_name_len);
} else if (can_list(strbuf)) {
if (size < (res + name_len(strbuf, xattr_name_len))) {
res = -ERANGE;
goto end_listxattr;
} else
res += copy_name(buffer + res,
strbuf, xattr_name_len);
}
if (hfs_brec_goto(&fd, 1))
goto end_listxattr;
}
end_listxattr:
kfree(strbuf);
out:
hfs_find_exit(&fd);
return res;
}
static int hfsplus_removexattr(struct inode *inode, const char *name)
{
int err = 0;
struct hfs_find_data cat_fd;
u16 flags;
u16 cat_entry_type;
int is_xattr_acl_deleted = 0;
int is_all_xattrs_deleted = 0;
if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
return -EOPNOTSUPP;
if (!strcmp_xattr_finder_info(name))
return -EOPNOTSUPP;
err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &cat_fd);
if (err) {
pr_err("can't init xattr find struct\n");
return err;
}
err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &cat_fd);
if (err) {
pr_err("catalog searching failed\n");
goto end_removexattr;
}
err = hfsplus_delete_attr(inode, name);
if (err)
goto end_removexattr;
is_xattr_acl_deleted = !strcmp_xattr_acl(name);
is_all_xattrs_deleted = !hfsplus_attr_exists(inode, NULL);
if (!is_xattr_acl_deleted && !is_all_xattrs_deleted)
goto end_removexattr;
cat_entry_type = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset);
if (cat_entry_type == HFSPLUS_FOLDER) {
flags = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset +
offsetof(struct hfsplus_cat_folder, flags));
if (is_xattr_acl_deleted)
flags &= ~HFSPLUS_ACL_EXISTS;
if (is_all_xattrs_deleted)
flags &= ~HFSPLUS_XATTR_EXISTS;
hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
offsetof(struct hfsplus_cat_folder, flags),
flags);
hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
} else if (cat_entry_type == HFSPLUS_FILE) {
flags = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset +
offsetof(struct hfsplus_cat_file, flags));
if (is_xattr_acl_deleted)
flags &= ~HFSPLUS_ACL_EXISTS;
if (is_all_xattrs_deleted)
flags &= ~HFSPLUS_XATTR_EXISTS;
hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
offsetof(struct hfsplus_cat_file, flags),
flags);
hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
} else {
pr_err("invalid catalog entry type\n");
err = -EIO;
goto end_removexattr;
}
end_removexattr:
hfs_find_exit(&cat_fd);
return err;
}
static int hfsplus_osx_getxattr(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
const char *name, void *buffer, size_t size)
{
/*
* Don't allow retrieving properly prefixed attributes
* by prepending them with "osx."
*/
if (is_known_namespace(name))
return -EOPNOTSUPP;
/*
* osx is the namespace we use to indicate an unprefixed
* attribute on the filesystem (like the ones that OS X
* creates), so we pass the name through unmodified (after
* ensuring it doesn't conflict with another namespace).
*/
return __hfsplus_getxattr(inode, name, buffer, size);
}
static int hfsplus_osx_setxattr(const struct xattr_handler *handler,
struct user_namespace *mnt_userns,
struct dentry *unused, struct inode *inode,
const char *name, const void *buffer,
size_t size, int flags)
{
/*
* Don't allow setting properly prefixed attributes
* by prepending them with "osx."
*/
if (is_known_namespace(name))
return -EOPNOTSUPP;
/*
* osx is the namespace we use to indicate an unprefixed
* attribute on the filesystem (like the ones that OS X
* creates), so we pass the name through unmodified (after
* ensuring it doesn't conflict with another namespace).
*/
return __hfsplus_setxattr(inode, name, buffer, size, flags);
}
const struct xattr_handler hfsplus_xattr_osx_handler = {
.prefix = XATTR_MAC_OSX_PREFIX,
.get = hfsplus_osx_getxattr,
.set = hfsplus_osx_setxattr,
};