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-rw-r--r--fs/ntfs3/dir.c593
1 files changed, 593 insertions, 0 deletions
diff --git a/fs/ntfs3/dir.c b/fs/ntfs3/dir.c
new file mode 100644
index 000000000000..fb438d604040
--- /dev/null
+++ b/fs/ntfs3/dir.c
@@ -0,0 +1,593 @@
+// 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(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;
+}
+
+static inline int ntfs_filldir(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 0;
+
+ if (!mi_is_ref(&ni->mi, &fname->home))
+ return 0;
+
+ ino = ino_get(&e->ref);
+
+ if (ino == MFT_REC_ROOT)
+ return 0;
+
+ /* Skip meta files. Unless option to show metafiles is set. */
+ if (!sbi->options->showmeta && ntfs_is_meta_file(sbi, ino))
+ return 0;
+
+ if (sbi->options->nohidden && (fname->dup.fa & FILE_ATTRIBUTE_HIDDEN))
+ return 0;
+
+ 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 0;
+ }
+
+ dt_type = (fname->dup.fa & FILE_ATTRIBUTE_DIRECTORY) ? DT_DIR : DT_REG;
+
+ return !dir_emit(ctx, (s8 *)name, name_len, ino, dt_type);
+}
+
+/*
+ * ntfs_read_hdr - Helper function for ntfs_readdir().
+ */
+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)
+{
+ int err;
+ 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 -1;
+
+ e = Add2Ptr(hdr, off);
+ e_size = le16_to_cpu(e->size);
+ if (e_size < sizeof(struct NTFS_DE) || off + e_size > end)
+ return -1;
+
+ 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 -1;
+
+ ctx->pos = vbo + off;
+
+ /* Submit the name to the filldir callback. */
+ err = ntfs_filldir(sbi, ni, e, name, ctx);
+ if (err)
+ return err;
+ }
+}
+
+/*
+ * 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) {
+ ntfs_inode_err(dir, "Looks like your dir is corrupt");
+ 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 == -ENOENT) {
+ err = 0;
+ ctx->pos = pos;
+ }
+
+ 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;
+ u64 vbo = 0;
+ size_t drs = 0, fles = 0, bit = 0;
+ loff_t i_size = ni->vfs_inode.i_size;
+ struct indx_node *node = NULL;
+ u8 index_bits = 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)
+ 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 (vbo >= i_size)
+ goto out;
+
+ err = indx_used_bit(&ni->dir, ni, &bit);
+ if (err)
+ goto out;
+
+ if (bit == MINUS_ONE_T)
+ goto out;
+
+ vbo = (u64)bit << index_bits;
+ if (vbo >= i_size)
+ goto out;
+
+ err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits,
+ &node);
+ if (err)
+ goto out;
+
+ hdr = &node->index->ihdr;
+ bit += 1;
+ vbo = (u64)bit << ni->dir.idx2vbn_bits;
+ }
+
+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,
+};
+// clang-format on
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.