- 根目录:
- fs
- hfsplus
- xattr.c
/*
* linux/fs/hfsplus/xattr.c
*
* Vyacheslav Dubeyko <slava@dubeyko.com>
*
* Logic of processing extended attributes
*/
#include "hfsplus_fs.h"
#include "xattr.h"
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 inline int 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 int can_set_xattr(struct inode *inode, const char *name,
const void *value, size_t value_len)
{
if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
return -EOPNOTSUPP; /* TODO: implement ACL support */
if (!strncmp(name, XATTR_MAC_OSX_PREFIX, XATTR_MAC_OSX_PREFIX_LEN)) {
/*
* This makes sure that we aren't trying to set an
* attribute in a different namespace by prefixing it
* with "osx."
*/
if (is_known_namespace(name + XATTR_MAC_OSX_PREFIX_LEN))
return -EOPNOTSUPP;
return 0;
}
/*
* Don't allow setting an attribute in an unknown namespace.
*/
if (strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) &&
strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
return -EOPNOTSUPP;
return 0;
}
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;
err = can_set_xattr(inode, name, value, size);
if (err)
return err;
if (strncmp(name, XATTR_MAC_OSX_PREFIX,
XATTR_MAC_OSX_PREFIX_LEN) == 0)
name += XATTR_MAC_OSX_PREFIX_LEN;
if (value == NULL) {
value = "";
size = 0;
}
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 = -EOPNOTSUPP;
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 inline int is_osx_xattr(const char *xattr_name)
{
return !is_known_namespace(xattr_name);
}
static int name_len(const char *xattr_name, int xattr_name_len)
{
int len = xattr_name_len + 1;
if (is_osx_xattr(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_osx_xattr(xattr_name)) {
strncpy(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;
}
static ssize_t hfsplus_getxattr_finder_info(struct dentry *dentry,
void *value, size_t size)
{
ssize_t res = 0;
struct inode *inode = dentry->d_inode;
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 dentry *dentry, const char *name,
void *value, size_t size)
{
struct inode *inode = dentry->d_inode;
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 (strncmp(name, XATTR_MAC_OSX_PREFIX,
XATTR_MAC_OSX_PREFIX_LEN) == 0) {
/* skip "osx." prefix */
name += XATTR_MAC_OSX_PREFIX_LEN;
/*
* Don't allow retrieving properly prefixed attributes
* by prepending them with "osx."
*/
if (is_known_namespace(name))
return -EOPNOTSUPP;
}
if (!strcmp_xattr_finder_info(name))
return hfsplus_getxattr_finder_info(dentry, 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;
}
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 = dentry->d_inode;
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 = dentry->d_inode;
struct hfs_find_data fd;
u16 key_len = 0;
struct hfsplus_attr_key attr_key;
char strbuf[HFSPLUS_ATTR_MAX_STRLEN +
XATTR_MAC_OSX_PREFIX_LEN + 1] = {0};
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;
}
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 = 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:
hfs_find_exit(&fd);
return res;
}
int hfsplus_removexattr(struct dentry *dentry, const char *name)
{
int err = 0;
struct inode *inode = dentry->d_inode;
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 ((!S_ISREG(inode->i_mode) &&
!S_ISDIR(inode->i_mode)) ||
HFSPLUS_IS_RSRC(inode))
return -EOPNOTSUPP;
if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
return -EOPNOTSUPP;
err = can_set_xattr(inode, name, NULL, 0);
if (err)
return err;
if (strncmp(name, XATTR_MAC_OSX_PREFIX,
XATTR_MAC_OSX_PREFIX_LEN) == 0)
name += XATTR_MAC_OSX_PREFIX_LEN;
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(struct dentry *dentry, const char *name,
void *buffer, size_t size, int type)
{
char xattr_name[HFSPLUS_ATTR_MAX_STRLEN +
XATTR_MAC_OSX_PREFIX_LEN + 1] = {0};
size_t len = strlen(name);
if (!strcmp(name, ""))
return -EINVAL;
if (len > HFSPLUS_ATTR_MAX_STRLEN)
return -EOPNOTSUPP;
strcpy(xattr_name, XATTR_MAC_OSX_PREFIX);
strcpy(xattr_name + XATTR_MAC_OSX_PREFIX_LEN, name);
return hfsplus_getxattr(dentry, xattr_name, buffer, size);
}
static int hfsplus_osx_setxattr(struct dentry *dentry, const char *name,
const void *buffer, size_t size, int flags, int type)
{
char xattr_name[HFSPLUS_ATTR_MAX_STRLEN +
XATTR_MAC_OSX_PREFIX_LEN + 1] = {0};
size_t len = strlen(name);
if (!strcmp(name, ""))
return -EINVAL;
if (len > HFSPLUS_ATTR_MAX_STRLEN)
return -EOPNOTSUPP;
strcpy(xattr_name, XATTR_MAC_OSX_PREFIX);
strcpy(xattr_name + XATTR_MAC_OSX_PREFIX_LEN, name);
return hfsplus_setxattr(dentry, xattr_name, buffer, size, flags);
}
static size_t hfsplus_osx_listxattr(struct dentry *dentry, char *list,
size_t list_size, const char *name, size_t name_len, int type)
{
/*
* This method is not used.
* It is used hfsplus_listxattr() instead of generic_listxattr().
*/
return -EOPNOTSUPP;
}
const struct xattr_handler hfsplus_xattr_osx_handler = {
.prefix = XATTR_MAC_OSX_PREFIX,
.list = hfsplus_osx_listxattr,
.get = hfsplus_osx_getxattr,
.set = hfsplus_osx_setxattr,
};