* [PATCH v2 1/2] fs/ntfs3: add windows_names mount option
2022-10-10 11:11 [PATCH v2 0/2] fs/ntfs3: Add windows_names mount option Daniel Pinto
@ 2022-10-10 11:14 ` Daniel Pinto
2022-10-10 11:16 ` [PATCH v2 2/2] fs/ntfs3: document " Daniel Pinto
2022-11-12 18:16 ` [PATCH v2 0/2] fs/ntfs3: Add " Konstantin Komarov
2 siblings, 0 replies; 4+ messages in thread
From: Daniel Pinto @ 2022-10-10 11:14 UTC (permalink / raw)
To: Konstantin Komarov, ntfs3, linux-fsdevel, linux-kernel
When enabled, the windows_names mount option prevents the creation
of files or directories with names not allowed by Windows. Use
the same option name as NTFS-3G for compatibility.
Signed-off-by: Daniel Pinto <danielpinto52@gmail.com>
---
fs/ntfs3/frecord.c | 7 ++-
fs/ntfs3/fsntfs.c | 104 +++++++++++++++++++++++++++++++++++++++++++++
fs/ntfs3/inode.c | 7 +++
fs/ntfs3/ntfs_fs.h | 2 +
fs/ntfs3/super.c | 7 +++
5 files changed, 126 insertions(+), 1 deletion(-)
diff --git a/fs/ntfs3/frecord.c b/fs/ntfs3/frecord.c
index 70a80f9412f7..ce5e8f3b1aca 100644
--- a/fs/ntfs3/frecord.c
+++ b/fs/ntfs3/frecord.c
@@ -3011,6 +3011,7 @@ int ni_add_name(struct ntfs_inode *dir_ni, struct ntfs_inode *ni,
struct NTFS_DE *de)
{
int err;
+ struct ntfs_sb_info *sbi = ni->mi.sbi;
struct ATTRIB *attr;
struct ATTR_LIST_ENTRY *le;
struct mft_inode *mi;
@@ -3018,6 +3019,10 @@ int ni_add_name(struct ntfs_inode *dir_ni, struct ntfs_inode *ni,
struct ATTR_FILE_NAME *de_name = (struct ATTR_FILE_NAME *)(de + 1);
u16 de_key_size = le16_to_cpu(de->key_size);
+ if (sbi->options->windows_names &&
+ !valid_windows_name(sbi, (struct le_str *)&de_name->name_len))
+ return -EINVAL;
+
mi_get_ref(&ni->mi, &de->ref);
mi_get_ref(&dir_ni->mi, &de_name->home);
@@ -3036,7 +3041,7 @@ int ni_add_name(struct ntfs_inode *dir_ni, struct ntfs_inode *ni,
memcpy(Add2Ptr(attr, SIZEOF_RESIDENT), de_name, de_key_size);
/* Insert new name into directory. */
- err = indx_insert_entry(&dir_ni->dir, dir_ni, de, ni->mi.sbi, NULL, 0);
+ err = indx_insert_entry(&dir_ni->dir, dir_ni, de, sbi, NULL, 0);
if (err)
ni_remove_attr_le(ni, attr, mi, le);
diff --git a/fs/ntfs3/fsntfs.c b/fs/ntfs3/fsntfs.c
index 4ed15f64b17f..674b644e1070 100644
--- a/fs/ntfs3/fsntfs.c
+++ b/fs/ntfs3/fsntfs.c
@@ -98,6 +98,30 @@ const __le16 WOF_NAME[17] = {
};
#endif
+static const __le16 CON_NAME[3] = {
+ cpu_to_le16('C'), cpu_to_le16('O'), cpu_to_le16('N'),
+};
+
+static const __le16 NUL_NAME[3] = {
+ cpu_to_le16('N'), cpu_to_le16('U'), cpu_to_le16('L'),
+};
+
+static const __le16 AUX_NAME[3] = {
+ cpu_to_le16('A'), cpu_to_le16('U'), cpu_to_le16('X'),
+};
+
+static const __le16 PRN_NAME[3] = {
+ cpu_to_le16('P'), cpu_to_le16('R'), cpu_to_le16('N'),
+};
+
+static const __le16 COM_NAME[3] = {
+ cpu_to_le16('C'), cpu_to_le16('O'), cpu_to_le16('M'),
+};
+
+static const __le16 LPT_NAME[3] = {
+ cpu_to_le16('L'), cpu_to_le16('P'), cpu_to_le16('T'),
+};
+
// clang-format on
/*
@@ -2502,3 +2526,83 @@ int run_deallocate(struct ntfs_sb_info *sbi, struct runs_tree *run, bool trim)
return 0;
}
+
+static inline bool name_has_forbidden_chars(const struct le_str *fname)
+{
+ int i, ch;
+
+ /* check for forbidden chars */
+ for (i = 0; i < fname->len; ++i) {
+ ch = le16_to_cpu(fname->name[i]);
+
+ /* control chars */
+ if (ch < 0x20)
+ return true;
+
+ switch (ch) {
+ /* disallowed by Windows */
+ case '\\':
+ case '/':
+ case ':':
+ case '*':
+ case '?':
+ case '<':
+ case '>':
+ case '|':
+ case '\"':
+ return true;
+
+ default:
+ /* allowed char */
+ break;
+ }
+ }
+
+ /* file names cannot end with space or . */
+ if (fname->len > 0) {
+ ch = le16_to_cpu(fname->name[fname->len - 1]);
+ if (ch == ' ' || ch == '.')
+ return true;
+ }
+
+ return false;
+}
+
+static inline bool is_reserved_name(struct ntfs_sb_info *sbi,
+ const struct le_str *fname)
+{
+ int port_digit;
+ const __le16 *name = fname->name;
+ int len = fname->len;
+ u16 *upcase = sbi->upcase;
+
+ /* check for 3 chars reserved names (device names) */
+ /* name by itself or with any extension is forbidden */
+ if (len == 3 || (len > 3 && le16_to_cpu(name[3]) == '.'))
+ if (!ntfs_cmp_names(name, 3, CON_NAME, 3, upcase, false) ||
+ !ntfs_cmp_names(name, 3, NUL_NAME, 3, upcase, false) ||
+ !ntfs_cmp_names(name, 3, AUX_NAME, 3, upcase, false) ||
+ !ntfs_cmp_names(name, 3, PRN_NAME, 3, upcase, false))
+ return true;
+
+ /* check for 4 chars reserved names (port name followed by 1..9) */
+ /* name by itself or with any extension is forbidden */
+ if (len == 4 || (len > 4 && le16_to_cpu(name[4]) == '.')) {
+ port_digit = le16_to_cpu(name[3]);
+ if (port_digit >= '1' && port_digit <= '9')
+ if (!ntfs_cmp_names(name, 3, COM_NAME, 3, upcase, false) ||
+ !ntfs_cmp_names(name, 3, LPT_NAME, 3, upcase, false))
+ return true;
+ }
+
+ return false;
+}
+
+/*
+ * valid_windows_name - Check if a file name is valid in Windows.
+ */
+bool valid_windows_name(struct ntfs_sb_info *sbi, const struct le_str *fname)
+{
+ return !name_has_forbidden_chars(fname) &&
+ !is_reserved_name(sbi, fname);
+}
diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index e9cf00d14733..4eb298e2ee98 100644
--- a/fs/ntfs3/inode.c
+++ b/fs/ntfs3/inode.c
@@ -1361,6 +1361,13 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns,
mi_get_ref(&ni->mi, &new_de->ref);
fname = (struct ATTR_FILE_NAME *)(new_de + 1);
+
+ if (sbi->options->windows_names &&
+ !valid_windows_name(sbi, (struct le_str *)&fname->name_len)) {
+ err = -EINVAL;
+ goto out4;
+ }
+
mi_get_ref(&dir_ni->mi, &fname->home);
fname->dup.cr_time = fname->dup.m_time = fname->dup.c_time =
fname->dup.a_time = std5->cr_time;
diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index 6c1c7ef3b2d6..ebfb720fc4fd 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -98,6 +98,7 @@ struct ntfs_mount_options {
unsigned showmeta : 1; /* Show meta files. */
unsigned nohidden : 1; /* Do not show hidden files. */
unsigned hide_dot_files : 1; /* Set hidden flag on dot files. */
+ unsigned windows_names : 1; /* Disallow names forbidden by Windows. */
unsigned force : 1; /* RW mount dirty volume. */
unsigned noacsrules : 1; /* Exclude acs rules. */
unsigned prealloc : 1; /* Preallocate space when file is growing. */
@@ -645,6 +646,7 @@ int ntfs_remove_reparse(struct ntfs_sb_info *sbi, __le32 rtag,
const struct MFT_REF *ref);
void mark_as_free_ex(struct ntfs_sb_info *sbi, CLST lcn, CLST len, bool trim);
int run_deallocate(struct ntfs_sb_info *sbi, struct runs_tree *run, bool trim);
+bool valid_windows_name(struct ntfs_sb_info *sbi, const struct le_str *name);
/* Globals from index.c */
int indx_used_bit(struct ntfs_index *indx, struct ntfs_inode *ni, size_t *bit);
diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index 1e2c04e48f98..6f3485fad417 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -248,6 +248,7 @@ enum Opt {
Opt_sparse,
Opt_nohidden,
Opt_hide_dot_files,
+ Opt_windows_names,
Opt_showmeta,
Opt_acl,
Opt_iocharset,
@@ -269,6 +270,7 @@ static const struct fs_parameter_spec ntfs_fs_parameters[] = {
fsparam_flag_no("sparse", Opt_sparse),
fsparam_flag_no("hidden", Opt_nohidden),
fsparam_flag_no("hidedotfiles", Opt_hide_dot_files),
+ fsparam_flag_no("windows_names", Opt_windows_names),
fsparam_flag_no("acl", Opt_acl),
fsparam_flag_no("showmeta", Opt_showmeta),
fsparam_flag_no("prealloc", Opt_prealloc),
@@ -361,6 +363,9 @@ static int ntfs_fs_parse_param(struct fs_context *fc,
case Opt_hide_dot_files:
opts->hide_dot_files = result.negated ? 1 : 0;
break;
+ case Opt_windows_names:
+ opts->windows_names = result.negated ? 0 : 1;
+ break;
case Opt_acl:
if (!result.negated)
#ifdef CONFIG_NTFS3_FS_POSIX_ACL
@@ -561,6 +566,8 @@ static int ntfs_show_options(struct seq_file *m, struct dentry *root)
seq_puts(m, ",showmeta");
if (opts->nohidden)
seq_puts(m, ",nohidden");
+ if (opts->windows_names)
+ seq_puts(m, ",windows_names");
if (opts->force)
seq_puts(m, ",force");
if (opts->noacsrules)
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