diff options
Diffstat (limited to 'src/vfs/undelfs/undelfs.c')
| -rw-r--r-- | src/vfs/undelfs/undelfs.c | 844 |
1 files changed, 844 insertions, 0 deletions
diff --git a/src/vfs/undelfs/undelfs.c b/src/vfs/undelfs/undelfs.c new file mode 100644 index 0000000..de54440 --- /dev/null +++ b/src/vfs/undelfs/undelfs.c @@ -0,0 +1,844 @@ +/* + UnDel File System: Midnight Commander file system. + + This file system is intended to be used together with the + ext2fs library to recover files from ext2fs file systems. + + Parts of this program were taken from the lsdel.c and dump.c files + written by Ted Ts'o (tytso@mit.edu) for the ext2fs package. + + Copyright (C) 1995-2023 + Free Software Foundation, Inc. + + Written by: + Miguel de Icaza, 1995 + Norbert Warmuth, 1997 + Pavel Machek, 2000 + + This file is part of the Midnight Commander. + + The Midnight Commander is free software: you can redistribute it + and/or modify it under the terms of the GNU General Public License as + published by the Free Software Foundation, either version 3 of the License, + or (at your option) any later version. + + The Midnight Commander is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/** + * \file + * \brief Source: UnDel File System + * + * Assumptions: + * + * 1. We don't handle directories (thus undelfs_get_path is easy to write). + * 2. Files are on the local file system (we do not support vfs files + * because we would have to provide an io_manager for the ext2fs tools, + * and I don't think it would be too useful to undelete files + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> /* memset() */ +#include <ext2fs/ext2_fs.h> +#include <ext2fs/ext2fs.h> +#include <ctype.h> + +#include "lib/global.h" + +#include "lib/util.h" +#include "lib/widget.h" /* message() */ +#include "lib/vfs/xdirentry.h" +#include "lib/vfs/utilvfs.h" +#include "lib/vfs/vfs.h" + +#include "undelfs.h" + +/*** global variables ****************************************************************************/ + +/*** file scope macro definitions ****************************************************************/ + +/* To generate the . and .. entries use -2 */ +#define READDIR_PTR_INIT 0 + +#define undelfs_stat undelfs_lstat + +/*** file scope type declarations ****************************************************************/ + +struct deleted_info +{ + ext2_ino_t ino; + unsigned short mode; + unsigned short uid; + unsigned short gid; + unsigned long size; + time_t dtime; + int num_blocks; + int free_blocks; +}; + +struct lsdel_struct +{ + ext2_ino_t inode; + int num_blocks; + int free_blocks; + int bad_blocks; +}; + +typedef struct +{ + int f_index; /* file index into delarray */ + char *buf; + int error_code; /* */ + off_t pos; /* file position */ + off_t current; /* used to determine current position in itereate */ + gboolean finished; + ext2_ino_t inode; + int bytes_read; + off_t size; + + /* Used by undelfs_read: */ + char *dest_buffer; /* destination buffer */ + size_t count; /* bytes to read */ +} undelfs_file; + +/*** forward declarations (file scope functions) *************************************************/ + +/*** file scope variables ************************************************************************/ + +/* We only allow one opened ext2fs */ +static char *ext2_fname; +static ext2_filsys fs = NULL; +static struct lsdel_struct lsd; +static struct deleted_info *delarray; +static int num_delarray, max_delarray; +static char *block_buf; +static const char *undelfserr = N_("undelfs: error"); +static int readdir_ptr; +static int undelfs_usage; + +static struct vfs_s_subclass undelfs_subclass; +static struct vfs_class *vfs_undelfs_ops = VFS_CLASS (&undelfs_subclass); + +/* --------------------------------------------------------------------------------------------- */ +/*** file scope functions ************************************************************************/ +/* --------------------------------------------------------------------------------------------- */ + +static void +undelfs_shutdown (void) +{ + if (fs) + ext2fs_close (fs); + fs = NULL; + MC_PTR_FREE (ext2_fname); + MC_PTR_FREE (delarray); + MC_PTR_FREE (block_buf); +} + +/* --------------------------------------------------------------------------------------------- */ + +static void +undelfs_get_path (const vfs_path_t * vpath, char **fsname, char **file) +{ + const char *p, *dirname; + + dirname = vfs_path_get_last_path_str (vpath); + + /* To look like filesystem, we have virtual directories + undel://XXX, which have no subdirectories. XXX is replaced with + hda5, sdb8 etc, which is assumed to live under /dev. + -- pavel@ucw.cz */ + + *fsname = NULL; + + if (strncmp (dirname, "undel://", 8) != 0) + return; + + dirname += 8; + + /* Since we don't allow subdirectories, it's easy to get a filename, + * just scan backwards for a slash */ + if (*dirname == '\0') + return; + + p = dirname + strlen (dirname); +#if 0 + /* Strip trailing ./ + */ + if (p - dirname > 2 && IS_PATH_SEP (p[-1]) && p[-2] == '.') + *(p = p - 2) = 0; +#endif + + while (p > dirname) + { + if (IS_PATH_SEP (*p)) + { + char *tmp; + + *file = g_strdup (p + 1); + tmp = g_strndup (dirname, p - dirname); + *fsname = g_strconcat ("/dev/", tmp, (char *) NULL); + g_free (tmp); + return; + } + p--; + } + *file = g_strdup (""); + *fsname = g_strconcat ("/dev/", dirname, (char *) NULL); +} + +/* --------------------------------------------------------------------------------------------- */ + +static int +undelfs_lsdel_proc (ext2_filsys _fs, blk_t * block_nr, int blockcnt, void *private) +{ + struct lsdel_struct *_lsd = (struct lsdel_struct *) private; + (void) blockcnt; + _lsd->num_blocks++; + + if (*block_nr < _fs->super->s_first_data_block || *block_nr >= _fs->super->s_blocks_count) + { + _lsd->bad_blocks++; + return BLOCK_ABORT; + } + + if (!ext2fs_test_block_bitmap (_fs->block_map, *block_nr)) + _lsd->free_blocks++; + + return 0; +} + +/* --------------------------------------------------------------------------------------------- */ +/** + * Load information about deleted files. + * Don't abort if there is not enough memory - load as much as we can. + */ + +static int +undelfs_loaddel (void) +{ + int retval, count; + ext2_ino_t ino; + struct ext2_inode inode; + ext2_inode_scan scan; + + max_delarray = 100; + num_delarray = 0; + delarray = g_try_malloc (sizeof (struct deleted_info) * max_delarray); + if (!delarray) + { + message (D_ERROR, undelfserr, "%s", _("not enough memory")); + return 0; + } + block_buf = g_try_malloc (fs->blocksize * 3); + if (!block_buf) + { + message (D_ERROR, undelfserr, "%s", _("while allocating block buffer")); + goto free_delarray; + } + retval = ext2fs_open_inode_scan (fs, 0, &scan); + if (retval != 0) + { + message (D_ERROR, undelfserr, _("open_inode_scan: %d"), retval); + goto free_block_buf; + } + retval = ext2fs_get_next_inode (scan, &ino, &inode); + if (retval != 0) + { + message (D_ERROR, undelfserr, _("while starting inode scan %d"), retval); + goto error_out; + } + count = 0; + while (ino) + { + if ((count++ % 1024) == 0) + vfs_print_message (_("undelfs: loading deleted files information %d inodes"), count); + if (inode.i_dtime == 0) + goto next; + + if (S_ISDIR (inode.i_mode)) + goto next; + + lsd.inode = ino; + lsd.num_blocks = 0; + lsd.free_blocks = 0; + lsd.bad_blocks = 0; + + retval = ext2fs_block_iterate (fs, ino, 0, block_buf, undelfs_lsdel_proc, &lsd); + if (retval) + { + message (D_ERROR, undelfserr, _("while calling ext2_block_iterate %d"), retval); + goto next; + } + if (lsd.free_blocks && !lsd.bad_blocks) + { + if (num_delarray >= max_delarray) + { + struct deleted_info *delarray_new = g_try_realloc (delarray, + sizeof (struct deleted_info) * + (max_delarray + 50)); + if (!delarray_new) + { + message (D_ERROR, undelfserr, "%s", + _("no more memory while reallocating array")); + goto error_out; + } + delarray = delarray_new; + max_delarray += 50; + } + + delarray[num_delarray].ino = ino; + delarray[num_delarray].mode = inode.i_mode; + delarray[num_delarray].uid = inode.i_uid; + delarray[num_delarray].gid = inode.i_gid; + delarray[num_delarray].size = inode.i_size; + delarray[num_delarray].dtime = inode.i_dtime; + delarray[num_delarray].num_blocks = lsd.num_blocks; + delarray[num_delarray].free_blocks = lsd.free_blocks; + num_delarray++; + } + + next: + retval = ext2fs_get_next_inode (scan, &ino, &inode); + if (retval) + { + message (D_ERROR, undelfserr, _("while doing inode scan %d"), retval); + goto error_out; + } + } + readdir_ptr = READDIR_PTR_INIT; + ext2fs_close_inode_scan (scan); + return 1; + + error_out: + ext2fs_close_inode_scan (scan); + free_block_buf: + MC_PTR_FREE (block_buf); + free_delarray: + MC_PTR_FREE (delarray); + return 0; +} + +/* --------------------------------------------------------------------------------------------- */ + +static void * +undelfs_opendir (const vfs_path_t * vpath) +{ + char *file, *f = NULL; + const char *class_name; + + class_name = vfs_path_get_last_path_vfs (vpath)->name; + undelfs_get_path (vpath, &file, &f); + if (file == NULL) + { + g_free (f); + return 0; + } + + /* We don't use the file name */ + g_free (f); + + if (!ext2_fname || strcmp (ext2_fname, file)) + { + undelfs_shutdown (); + ext2_fname = file; + } + else + { + /* To avoid expensive re-scannings */ + readdir_ptr = READDIR_PTR_INIT; + g_free (file); + return fs; + } + + if (ext2fs_open (ext2_fname, 0, 0, 0, unix_io_manager, &fs)) + { + message (D_ERROR, undelfserr, _("Cannot open file %s"), ext2_fname); + return 0; + } + vfs_print_message ("%s", _("undelfs: reading inode bitmap...")); + if (ext2fs_read_inode_bitmap (fs)) + { + message (D_ERROR, undelfserr, _("Cannot load inode bitmap from:\n%s"), ext2_fname); + goto quit_opendir; + } + vfs_print_message ("%s", _("undelfs: reading block bitmap...")); + if (ext2fs_read_block_bitmap (fs)) + { + message (D_ERROR, undelfserr, _("Cannot load block bitmap from:\n%s"), ext2_fname); + goto quit_opendir; + } + /* Now load the deleted information */ + if (!undelfs_loaddel ()) + goto quit_opendir; + vfs_print_message (_("%s: done."), class_name); + return fs; + quit_opendir: + vfs_print_message (_("%s: failure"), class_name); + ext2fs_close (fs); + fs = NULL; + return 0; +} + +/* --------------------------------------------------------------------------------------------- */ + +static struct vfs_dirent * +undelfs_readdir (void *vfs_info) +{ + struct vfs_dirent *dirent; + + if (vfs_info != fs) + { + message (D_ERROR, undelfserr, "%s", _("vfs_info is not fs!")); + return NULL; + } + if (readdir_ptr == num_delarray) + return NULL; + if (readdir_ptr < 0) + dirent = vfs_dirent_init (NULL, readdir_ptr == -2 ? "." : "..", 0); /* FIXME: inode */ + else + { + char dirent_dest[MC_MAXPATHLEN]; + + g_snprintf (dirent_dest, MC_MAXPATHLEN, "%ld:%d", + (long) delarray[readdir_ptr].ino, delarray[readdir_ptr].num_blocks); + dirent = vfs_dirent_init (NULL, dirent_dest, 0); /* FIXME: inode */ + } + readdir_ptr++; + + return dirent; +} + +/* --------------------------------------------------------------------------------------------- */ + +static int +undelfs_closedir (void *vfs_info) +{ + (void) vfs_info; + return 0; +} + +/* --------------------------------------------------------------------------------------------- */ +/* We do not support lseek */ + +static void * +undelfs_open (const vfs_path_t * vpath, int flags, mode_t mode) +{ + char *file, *f = NULL; + ext2_ino_t inode, i; + undelfs_file *p = NULL; + (void) flags; + (void) mode; + + /* Only allow reads on this file system */ + undelfs_get_path (vpath, &file, &f); + if (file == NULL) + { + g_free (f); + return 0; + } + + if (!ext2_fname || strcmp (ext2_fname, file)) + { + message (D_ERROR, undelfserr, "%s", _("You have to chdir to extract files first")); + g_free (file); + g_free (f); + return 0; + } + inode = atol (f); + + /* Search the file into delarray */ + for (i = 0; i < (ext2_ino_t) num_delarray; i++) + { + if (inode != delarray[i].ino) + continue; + + /* Found: setup all the structures needed by read */ + p = (undelfs_file *) g_try_malloc (((gsize) sizeof (undelfs_file))); + if (!p) + { + g_free (file); + g_free (f); + return 0; + } + p->buf = g_try_malloc (fs->blocksize); + if (!p->buf) + { + g_free (p); + g_free (file); + g_free (f); + return 0; + } + p->inode = inode; + p->finished = FALSE; + p->f_index = i; + p->error_code = 0; + p->pos = 0; + p->size = delarray[i].size; + } + g_free (file); + g_free (f); + undelfs_usage++; + return p; +} + +/* --------------------------------------------------------------------------------------------- */ + +static int +undelfs_close (void *vfs_info) +{ + undelfs_file *p = vfs_info; + g_free (p->buf); + g_free (p); + undelfs_usage--; + return 0; +} + +/* --------------------------------------------------------------------------------------------- */ + +static int +undelfs_dump_read (ext2_filsys param_fs, blk_t * blocknr, int blockcnt, void *private) +{ + int copy_count; + undelfs_file *p = (undelfs_file *) private; + + if (blockcnt < 0) + return 0; + + if (*blocknr) + { + p->error_code = io_channel_read_blk (param_fs->io, *blocknr, 1, p->buf); + if (p->error_code) + return BLOCK_ABORT; + } + else + memset (p->buf, 0, param_fs->blocksize); + + if (p->pos + (off_t) p->count < p->current) + { + p->finished = TRUE; + return BLOCK_ABORT; + } + if (p->pos > p->current + param_fs->blocksize) + { + p->current += param_fs->blocksize; + return 0; /* we have not arrived yet */ + } + + /* Now, we know we have to extract some data */ + if (p->pos >= p->current) + { + + /* First case: starting pointer inside this block */ + if (p->pos + (off_t) p->count <= p->current + param_fs->blocksize) + { + /* Fully contained */ + copy_count = p->count; + p->finished = (p->count != 0); + } + else + { + /* Still some more data */ + copy_count = param_fs->blocksize - (p->pos - p->current); + } + memcpy (p->dest_buffer, p->buf + (p->pos - p->current), copy_count); + } + else + { + /* Second case: we already have passed p->pos */ + if (p->pos + (off_t) p->count < p->current + param_fs->blocksize) + { + copy_count = (p->pos + p->count) - p->current; + p->finished = (p->count != 0); + } + else + { + copy_count = param_fs->blocksize; + } + memcpy (p->dest_buffer, p->buf, copy_count); + } + p->dest_buffer += copy_count; + p->current += param_fs->blocksize; + if (p->finished) + { + return BLOCK_ABORT; + } + return 0; +} + +/* --------------------------------------------------------------------------------------------- */ + +static ssize_t +undelfs_read (void *vfs_info, char *buffer, size_t count) +{ + undelfs_file *p = vfs_info; + int retval; + + p->dest_buffer = buffer; + p->current = 0; + p->finished = FALSE; + p->count = count; + + if (p->pos + (off_t) p->count > p->size) + { + p->count = p->size - p->pos; + } + retval = ext2fs_block_iterate (fs, p->inode, 0, NULL, undelfs_dump_read, p); + if (retval) + { + message (D_ERROR, undelfserr, "%s", _("while iterating over blocks")); + return -1; + } + if (p->error_code && !p->finished) + return 0; + p->pos = p->pos + (p->dest_buffer - buffer); + return p->dest_buffer - buffer; +} + +/* --------------------------------------------------------------------------------------------- */ + +static long +undelfs_getindex (char *path) +{ + ext2_ino_t inode = atol (path); + int i; + + for (i = 0; i < num_delarray; i++) + { + if (delarray[i].ino == inode) + return i; + } + return -1; +} + +/* --------------------------------------------------------------------------------------------- */ + +static int +undelfs_stat_int (int inode_index, struct stat *buf) +{ + buf->st_dev = 0; + buf->st_ino = delarray[inode_index].ino; + buf->st_mode = delarray[inode_index].mode; + buf->st_nlink = 1; + buf->st_uid = delarray[inode_index].uid; + buf->st_gid = delarray[inode_index].gid; + buf->st_size = delarray[inode_index].size; + buf->st_atime = delarray[inode_index].dtime; + buf->st_ctime = delarray[inode_index].dtime; + buf->st_mtime = delarray[inode_index].dtime; +#ifdef HAVE_STRUCT_STAT_ST_MTIM + buf->st_atim.tv_nsec = buf->st_mtim.tv_nsec = buf->st_ctim.tv_nsec = 0; +#endif + return 0; +} + +/* --------------------------------------------------------------------------------------------- */ + +static int +undelfs_lstat (const vfs_path_t * vpath, struct stat *buf) +{ + int inode_index; + char *file, *f = NULL; + + undelfs_get_path (vpath, &file, &f); + if (file == NULL) + { + g_free (f); + return 0; + } + + /* When called from save_cwd_stats we get an incorrect file and f here: + e.g. incorrect correct + path = "undel:/dev/sda1" path="undel:/dev/sda1/401:1" + file = "/dev" file="/dev/sda1" + f = "sda1" f ="401:1" + If the first char in f is no digit -> return error */ + if (!isdigit (*f)) + { + g_free (file); + g_free (f); + return -1; + } + + if (!ext2_fname || strcmp (ext2_fname, file)) + { + g_free (file); + g_free (f); + message (D_ERROR, undelfserr, "%s", _("You have to chdir to extract files first")); + return 0; + } + inode_index = undelfs_getindex (f); + g_free (file); + g_free (f); + + if (inode_index == -1) + return -1; + + return undelfs_stat_int (inode_index, buf); +} + +/* --------------------------------------------------------------------------------------------- */ + +static int +undelfs_fstat (void *vfs_info, struct stat *buf) +{ + undelfs_file *p = vfs_info; + + return undelfs_stat_int (p->f_index, buf); +} + +/* --------------------------------------------------------------------------------------------- */ + +static int +undelfs_chdir (const vfs_path_t * vpath) +{ + char *file, *f = NULL; + int fd; + + undelfs_get_path (vpath, &file, &f); + if (file == NULL) + { + g_free (f); + return (-1); + } + + /* We may use access because ext2 file systems are local */ + /* this could be fixed by making an ext2fs io manager to use */ + /* our vfs, but that is left as an exercise for the reader */ + fd = open (file, O_RDONLY); + if (fd == -1) + { + message (D_ERROR, undelfserr, _("Cannot open file \"%s\""), file); + g_free (f); + g_free (file); + return -1; + } + close (fd); + g_free (f); + g_free (file); + return 0; +} + +/* --------------------------------------------------------------------------------------------- */ + +/* this has to stay here for now: vfs layer does not know how to emulate it */ +static off_t +undelfs_lseek (void *vfs_info, off_t offset, int whence) +{ + (void) vfs_info; + (void) offset; + (void) whence; + + return -1; +} + +/* --------------------------------------------------------------------------------------------- */ + +static vfsid +undelfs_getid (const vfs_path_t * vpath) +{ + char *fname = NULL, *fsname; + gboolean ok; + + undelfs_get_path (vpath, &fsname, &fname); + ok = fsname != NULL; + + g_free (fname); + g_free (fsname); + + return ok ? (vfsid) fs : NULL; +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +undelfs_nothingisopen (vfsid id) +{ + (void) id; + + return (undelfs_usage == 0); +} + +/* --------------------------------------------------------------------------------------------- */ + +static void +undelfs_free (vfsid id) +{ + (void) id; + + undelfs_shutdown (); +} + +/* --------------------------------------------------------------------------------------------- */ + +#ifdef ENABLE_NLS +static int +undelfs_init (struct vfs_class *me) +{ + (void) me; + + undelfserr = _(undelfserr); + return 1; +} +#else +#define undelfs_init NULL +#endif + +/* --------------------------------------------------------------------------------------------- */ +/*** public functions ****************************************************************************/ +/* --------------------------------------------------------------------------------------------- */ +/** + * This function overrides com_err() from libcom_err library. + * It is used in libext2fs to report errors. + */ + +void +com_err (const char *whoami, long err_code, const char *fmt, ...) +{ + va_list ap; + char *str; + + va_start (ap, fmt); + str = g_strdup_vprintf (fmt, ap); + va_end (ap); + + message (D_ERROR, _("Ext2lib error"), "%s (%s: %ld)", str, whoami, err_code); + g_free (str); +} + +/* --------------------------------------------------------------------------------------------- */ + +void +vfs_init_undelfs (void) +{ + /* NULLize vfs_s_subclass members */ + memset (&undelfs_subclass, 0, sizeof (undelfs_subclass)); + + vfs_init_class (vfs_undelfs_ops, "undelfs", VFSF_UNKNOWN, "undel"); + vfs_undelfs_ops->init = undelfs_init; + vfs_undelfs_ops->open = undelfs_open; + vfs_undelfs_ops->close = undelfs_close; + vfs_undelfs_ops->read = undelfs_read; + vfs_undelfs_ops->opendir = undelfs_opendir; + vfs_undelfs_ops->readdir = undelfs_readdir; + vfs_undelfs_ops->closedir = undelfs_closedir; + vfs_undelfs_ops->stat = undelfs_stat; + vfs_undelfs_ops->lstat = undelfs_lstat; + vfs_undelfs_ops->fstat = undelfs_fstat; + vfs_undelfs_ops->chdir = undelfs_chdir; + vfs_undelfs_ops->lseek = undelfs_lseek; + vfs_undelfs_ops->getid = undelfs_getid; + vfs_undelfs_ops->nothingisopen = undelfs_nothingisopen; + vfs_undelfs_ops->free = undelfs_free; + vfs_register_class (vfs_undelfs_ops); +} + +/* --------------------------------------------------------------------------------------------- */ |