// SPDX-License-Identifier: GPL-2.0
/*
*
* Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
*
* Directory handling functions for NTFS-based filesystems.
*
*/
#include <linux/fs.h>
#include <linux/nls.h>
#include "debug.h"
#include "ntfs.h"
#include "ntfs_fs.h"
/* Convert little endian UTF-16 to NLS string. */
int ntfs_utf16_to_nls(struct ntfs_sb_info *sbi, const __le16 *name, u32 len,
u8 *buf, int buf_len)
{
int ret, warn;
u8 *op;
struct nls_table *nls = sbi->options->nls;
static_assert(sizeof(wchar_t) == sizeof(__le16));
if (!nls) {
/* UTF-16 -> UTF-8 */
ret = utf16s_to_utf8s((wchar_t *)name, len, UTF16_LITTLE_ENDIAN,
buf, buf_len);
buf[ret] = '\0';
return ret;
}
op = buf;
warn = 0;
while (len--) {
u16 ec;
int charlen;
char dump[5];
if (buf_len < NLS_MAX_CHARSET_SIZE) {
ntfs_warn(sbi->sb,
"filename was truncated while converting.");
break;
}
ec = le16_to_cpu(*name++);
charlen = nls->uni2char(ec, op, buf_len);
if (charlen > 0) {
op += charlen;
buf_len -= charlen;
continue;
}
*op++ = '_';
buf_len -= 1;
if (warn)
continue;
warn = 1;
hex_byte_pack(&dump[0], ec >> 8);
hex_byte_pack(&dump[2], ec);
dump[4] = 0;
ntfs_err(sbi->sb, "failed to convert \"%s\" to %s", dump,
nls->charset);
}
*op = '\0';
return op - buf;
}
// clang-format off
#define PLANE_SIZE 0x00010000
#define SURROGATE_PAIR 0x0000d800
#define SURROGATE_LOW 0x00000400
#define SURROGATE_BITS 0x000003ff
// clang-format on
/*
* put_utf16 - Modified version of put_utf16 from fs/nls/nls_base.c
*
* Function is sparse warnings free.
*/
static inline void put_utf16(wchar_t *s, unsigned int c,
enum utf16_endian endian)
{
static_assert(sizeof(wchar_t) == sizeof(__le16));
static_assert(sizeof(wchar_t) == sizeof(__be16));
switch (endian) {
default:
*s = (wchar_t)c;
break;
case UTF16_LITTLE_ENDIAN:
*(__le16 *)s = __cpu_to_le16(c);
break;
case UTF16_BIG_ENDIAN:
*(__be16 *)s = __cpu_to_be16(c);
break;
}
}
/*
* _utf8s_to_utf16s
*
* Modified version of 'utf8s_to_utf16s' allows to
* detect -ENAMETOOLONG without writing out of expected maximum.
*/
static int _utf8s_to_utf16s(const u8 *s, int inlen, enum utf16_endian endian,
wchar_t *pwcs, int maxout)
{
u16 *op;
int size;
unicode_t u;
op = pwcs;
while (inlen > 0 && *s) {
if (*s & 0x80) {
size = utf8_to_utf32(s, inlen, &u);
if (size < 0)
return -EINVAL;
s += size;
inlen -= size;
if (u >= PLANE_SIZE) {
if (maxout < 2)
return -ENAMETOOLONG;
u -= PLANE_SIZE;
put_utf16(op++,
SURROGATE_PAIR |
((u >> 10) & SURROGATE_BITS),
endian);
put_utf16(op++,
SURROGATE_PAIR | SURROGATE_LOW |
(u & SURROGATE_BITS),
endian);
maxout -= 2;
} else {
if (maxout < 1)
return -ENAMETOOLONG;
put_utf16(op++, u, endian);
maxout--;
}
} else {
if (maxout < 1)
return -ENAMETOOLONG;
put_utf16(op++, *s++, endian);
inlen--;
maxout--;
}
}
return op - pwcs;
}
/*
* ntfs_nls_to_utf16 - Convert input string to UTF-16.
* @name: Input name.
* @name_len: Input name length.
* @uni: Destination memory.
* @max_ulen: Destination memory.
* @endian: Endian of target UTF-16 string.
*
* This function is called:
* - to create NTFS name
* - to create symlink
*
* Return: UTF-16 string length or error (if negative).
*/
int ntfs_nls_to_utf16(struct ntfs_sb_info *sbi, const u8 *name, u32 name_len,
struct cpu_str *uni, u32 max_ulen,
enum utf16_endian endian)
{
int ret, slen;
const u8 *end;
struct nls_table *nls = sbi->options->nls;
u16 *uname = uni->name;
static_assert(sizeof(wchar_t) == sizeof(u16));
if (!nls) {
/* utf8 -> utf16 */
ret = _utf8s_to_utf16s(name, name_len, endian, uname, max_ulen);
uni->len = ret;
return ret;
}
for (ret = 0, end = name + name_len; name < end; ret++, name += slen) {
if (ret >= max_ulen)
return -ENAMETOOLONG;
slen = nls->char2uni(name, end - name, uname + ret);
if (!slen)
return -EINVAL;
if (slen < 0)
return slen;
}
#ifdef __BIG_ENDIAN
if (endian == UTF16_LITTLE_ENDIAN) {
int i = ret;
while (i--) {
__cpu_to_le16s(uname);
uname++;
}
}
#else
if (endian == UTF16_BIG_ENDIAN) {
int i = ret;
while (i--) {
__cpu_to_be16s(uname);
uname++;
}
}
#endif
uni->len = ret;
return ret;
}
/*
* dir_search_u - Helper function.
*/
struct inode *dir_search_u(struct inode *dir, const struct cpu_str *uni,
struct ntfs_fnd *fnd)
{
int err = 0;
struct super_block *sb = dir->i_sb;
struct ntfs_sb_info *sbi = sb->s_fs_info;
struct ntfs_inode *ni = ntfs_i(dir);
struct NTFS_DE *e;
int diff;
struct inode *inode = NULL;
struct ntfs_fnd *fnd_a = NULL;
if (!fnd) {
fnd_a = fnd_get();
if (!fnd_a) {
err = -ENOMEM;
goto out;
}
fnd = fnd_a;
}
err = indx_find(&ni->dir, ni, NULL, uni, 0, sbi, &diff, &e, fnd);
if (err)
goto out;
if (diff) {
err = -ENOENT;
goto out;
}
inode = ntfs_iget5(sb, &e->ref, uni);
if (!IS_ERR(inode) && is_bad_inode(inode)) {
iput(inode);
err = -EINVAL;
}
out:
fnd_put(fnd_a);
return err == -ENOENT ? NULL : err ? ERR_PTR(err) : inode;
}
/*
* returns false if 'ctx' if full
*/
static inline bool ntfs_dir_emit(struct ntfs_sb_info *sbi,
struct ntfs_inode *ni, const struct NTFS_DE *e,
u8 *name, struct dir_context *ctx)
{
const struct ATTR_FILE_NAME *fname;
unsigned long ino;
int name_len;
u32 dt_type;
fname = Add2Ptr(e, sizeof(struct NTFS_DE));
if (fname->type == FILE_NAME_DOS)
return true;
if (!mi_is_ref(&ni->mi, &fname->home))
return true;
ino = ino_get(&e->ref);
if (ino == MFT_REC_ROOT)
return true;
/* Skip meta files. Unless option to show metafiles is set. */
if (!sbi->options->showmeta && ntfs_is_meta_file(sbi, ino))
return true;
if (sbi->options->nohidden && (fname->dup.fa & FILE_ATTRIBUTE_HIDDEN))
return true;
name_len = ntfs_utf16_to_nls(sbi, fname->name, fname->name_len, name,
PATH_MAX);
if (name_len <= 0) {
ntfs_warn(sbi->sb, "failed to convert name for inode %lx.",
ino);
return true;
}
/*
* NTFS: symlinks are "dir + reparse" or "file + reparse"
* Unfortunately reparse attribute is used for many purposes (several dozens).
* It is not possible here to know is this name symlink or not.
* To get exactly the type of name we should to open inode (read mft).
* getattr for opened file (fstat) correctly returns symlink.
*/
dt_type = (fname->dup.fa & FILE_ATTRIBUTE_DIRECTORY) ? DT_DIR : DT_REG;
/*
* It is not reliable to detect the type of name using duplicated information
* stored in parent directory.
* The only correct way to get the type of name - read MFT record and find ATTR_STD.
* The code below is not good idea.
* It does additional locks/reads just to get the type of name.
* Should we use additional mount option to enable branch below?
*/
if (((fname->dup.fa & FILE_ATTRIBUTE_REPARSE_POINT) ||
fname->dup.ea_size) &&
ino != ni->mi.rno) {
struct inode *inode = ntfs_iget5(sbi->sb, &e->ref, NULL);
if (!IS_ERR_OR_NULL(inode)) {
dt_type = fs_umode_to_dtype(inode->i_mode);
iput(inode);
}
}
return dir_emit(ctx, (s8 *)name, name_len, ino, dt_type);
}
/*
* ntfs_read_hdr - Helper function for ntfs_readdir().
*
* returns 0 if ok.
* returns -EINVAL if directory is corrupted.
* returns +1 if 'ctx' is full.
*/
static int ntfs_read_hdr(struct ntfs_sb_info *sbi, struct ntfs_inode *ni,
const struct INDEX_HDR *hdr, u64 vbo, u64 pos,
u8 *name, struct dir_context *ctx)
{
const struct NTFS_DE *e;
u32 e_size;
u32 end = le32_to_cpu(hdr->used);
u32 off = le32_to_cpu(hdr->de_off);
for (;; off += e_size) {
if (off + sizeof(struct NTFS_DE) > end)
return -EINVAL;
e = Add2Ptr(hdr, off);
e_size = le16_to_cpu(e->size);
if (e_size < sizeof(struct NTFS_DE) || off + e_size > end)
return -EINVAL;
if (de_is_last(e))
return 0;
/* Skip already enumerated. */
if (vbo + off < pos)
continue;
if (le16_to_cpu(e->key_size) < SIZEOF_ATTRIBUTE_FILENAME)
return -EINVAL;
ctx->pos = vbo + off;
/* Submit the name to the filldir callback. */
if (!ntfs_dir_emit(sbi, ni, e, name, ctx)) {
/* ctx is full. */
return +1;
}
}
}
/*
* ntfs_readdir - file_operations::iterate_shared
*
* Use non sorted enumeration.
* We have an example of broken volume where sorted enumeration
* counts each name twice.
*/
static int ntfs_readdir(struct file *file, struct dir_context *ctx)
{
const struct INDEX_ROOT *root;
u64 vbo;
size_t bit;
loff_t eod;
int err = 0;
struct inode *dir = file_inode(file);
struct ntfs_inode *ni = ntfs_i(dir);
struct super_block *sb = dir->i_sb;
struct ntfs_sb_info *sbi = sb->s_fs_info;
loff_t i_size = i_size_read(dir);
u32 pos = ctx->pos;
u8 *name = NULL;
struct indx_node *node = NULL;
u8 index_bits = ni->dir.index_bits;
/* Name is a buffer of PATH_MAX length. */
static_assert(NTFS_NAME_LEN * 4 < PATH_MAX);
eod = i_size + sbi->record_size;
if (pos >= eod)
return 0;
if (!dir_emit_dots(file, ctx))
return 0;
/* Allocate PATH_MAX bytes. */
name = __getname();
if (!name)
return -ENOMEM;
if (!ni->mi_loaded && ni->attr_list.size) {
/*
* Directory inode is locked for read.
* Load all subrecords to avoid 'write' access to 'ni' during
* directory reading.
*/
ni_lock(ni);
if (!ni->mi_loaded && ni->attr_list.size) {
err = ni_load_all_mi(ni);
if (!err)
ni->mi_loaded = true;
}
ni_unlock(ni);
if (err)
goto out;
}
root = indx_get_root(&ni->dir, ni, NULL, NULL);
if (!root) {
err = -EINVAL;
goto out;
}
if (pos >= sbi->record_size) {
bit = (pos - sbi->record_size) >> index_bits;
} else {
err = ntfs_read_hdr(sbi, ni, &root->ihdr, 0, pos, name, ctx);
if (err)
goto out;
bit = 0;
}
if (!i_size) {
ctx->pos = eod;
goto out;
}
for (;;) {
vbo = (u64)bit << index_bits;
if (vbo >= i_size) {
ctx->pos = eod;
goto out;
}
err = indx_used_bit(&ni->dir, ni, &bit);
if (err)
goto out;
if (bit == MINUS_ONE_T) {
ctx->pos = eod;
goto out;
}
vbo = (u64)bit << index_bits;
if (vbo >= i_size) {
err = -EINVAL;
goto out;
}
err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits,
&node);
if (err)
goto out;
err = ntfs_read_hdr(sbi, ni, &node->index->ihdr,
vbo + sbi->record_size, pos, name, ctx);
if (err)
goto out;
bit += 1;
}
out:
__putname(name);
put_indx_node(node);
if (err == 1) {
/* 'ctx' is full. */
err = 0;
} else if (err == -ENOENT) {
err = 0;
ctx->pos = pos;
} else if (err < 0) {
if (err == -EINVAL)
ntfs_inode_err(dir, "directory corrupted");
ctx->pos = eod;
}
return err;
}
static int ntfs_dir_count(struct inode *dir, bool *is_empty, size_t *dirs,
size_t *files)
{
int err = 0;
struct ntfs_inode *ni = ntfs_i(dir);
struct NTFS_DE *e = NULL;
struct INDEX_ROOT *root;
struct INDEX_HDR *hdr;
const struct ATTR_FILE_NAME *fname;
u32 e_size, off, end;
size_t drs = 0, fles = 0, bit = 0;
struct indx_node *node = NULL;
size_t max_indx = i_size_read(&ni->vfs_inode) >> ni->dir.index_bits;
if (is_empty)
*is_empty = true;
root = indx_get_root(&ni->dir, ni, NULL, NULL);
if (!root)
return -EINVAL;
hdr = &root->ihdr;
for (;;) {
end = le32_to_cpu(hdr->used);
off = le32_to_cpu(hdr->de_off);
for (; off + sizeof(struct NTFS_DE) <= end; off += e_size) {
e = Add2Ptr(hdr, off);
e_size = le16_to_cpu(e->size);
if (e_size < sizeof(struct NTFS_DE) ||
off + e_size > end) {
/* Looks like corruption. */
break;
}
if (de_is_last(e))
break;
fname = de_get_fname(e);
if (!fname)
continue;
if (fname->type == FILE_NAME_DOS)
continue;
if (is_empty) {
*is_empty = false;
if (!dirs && !files)
goto out;
}
if (fname->dup.fa & FILE_ATTRIBUTE_DIRECTORY)
drs += 1;
else
fles += 1;
}
if (bit >= max_indx)
goto out;
err = indx_used_bit(&ni->dir, ni, &bit);
if (err)
goto out;
if (bit == MINUS_ONE_T)
goto out;
if (bit >= max_indx)
goto out;
err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits,
&node);
if (err)
goto out;
hdr = &node->index->ihdr;
bit += 1;
}
out:
put_indx_node(node);
if (dirs)
*dirs = drs;
if (files)
*files = fles;
return err;
}
bool dir_is_empty(struct inode *dir)
{
bool is_empty = false;
ntfs_dir_count(dir, &is_empty, NULL, NULL);
return is_empty;
}
// clang-format off
const struct file_operations ntfs_dir_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate_shared = ntfs_readdir,
.fsync = generic_file_fsync,
.open = ntfs_file_open,
.unlocked_ioctl = ntfs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ntfs_compat_ioctl,
#endif
};
#if IS_ENABLED(CONFIG_NTFS_FS)
const struct file_operations ntfs_legacy_dir_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate_shared = ntfs_readdir,
.open = ntfs_file_open,
};
#endif
// clang-format on
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