The tsk_dirent struct contains the information gathered via TSK APIs. The struct contains the following fields: * tsk_inode: inode of a file * tsk_type: type of file such as for readdir command * tsk_size: file size in bytes * tsk_name: path relative to its disk partition * tsk_allocated: whether the file has been deleted Signed-off-by: Matteo Cafasso <noxdafox(a)gmail.com&gt; --- generator/structs.ml | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/generator/structs.ml b/generator/structs.ml index 6017ba6..d986fd9 100644 --- a/generator/structs.ml +++ b/generator/structs.ml @@ -442,8 +442,20 @@ let structs = [ "im_device", FString; "im_volume", FString; ]; - s_camel_name = "InternalMountable"; - }; + s_camel_name = "InternalMountable" }; + + (* The Sleuth Kit directory entry information. *) + { defaults with + s_name = "tsk_dirent"; + s_cols = [ + "tsk_inode", FUInt64; + "tsk_type", FChar; + "tsk_size", FInt64; + "tsk_name", FString; + "tsk_allocated", FUInt32; + ]; + s_camel_name = "TSKDirent" }; + ] (* end of structs *) let lookup_struct name = -- 2.8.0.rc3

The internal_filesystem_walk command walks through the FS structure of a disk partition and returns all the files or directories which could be found. The command is able to retrieve information regarding deleted or unaccessible files as well where other commands such as stat or find would fail. The gathered list of tsk_dirent structs is serialised into XDR format and written to a file by the appliance. Signed-off-by: Matteo Cafasso <noxdafox(a)gmail.com&gt; --- daemon/Makefile.am | 4 +- daemon/tsk.c | 225 +++++++++++++++++++++++++++++++++++++++++++++++++++ generator/actions.ml | 25 ++++++ src/MAX_PROC_NR | 2 +- 4 files changed, 254 insertions(+), 2 deletions(-) create mode 100644 daemon/tsk.c diff --git a/daemon/Makefile.am b/daemon/Makefile.am index beb7962..03bf71f 100644 --- a/daemon/Makefile.am +++ b/daemon/Makefile.am @@ -179,6 +179,7 @@ guestfsd_SOURCES = \ sync.c \ syslinux.c \ tar.c \ + tsk.c \ truncate.c \ umask.c \ upload.c \ @@ -209,7 +210,8 @@ guestfsd_LDADD = \ $(LIB_CLOCK_GETTIME) \ $(LIBINTL) \ $(SERVENT_LIB) \ - $(PCRE_LIBS) + $(PCRE_LIBS) \ + $(TSK_LIBS) guestfsd_CPPFLAGS = \ -I$(top_srcdir)/gnulib/lib \ diff --git a/daemon/tsk.c b/daemon/tsk.c new file mode 100644 index 0000000..ac44106 --- /dev/null +++ b/daemon/tsk.c @@ -0,0 +1,225 @@ +/* libguestfs - the guestfsd daemon + * Copyright (C) 2016 Red Hat Inc. + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <inttypes.h> +#include <string.h> +#include <unistd.h> +#include <rpc/xdr.h> +#include <rpc/types.h> + +#include "guestfs_protocol.h" +#include "daemon.h" +#include "actions.h" +#include "optgroups.h" + +#ifdef HAVE_LIBTSK + +#include <tsk/libtsk.h> + +/* File types map similar to dirent. */ +#define TSK_FILE_TYPE_NUM 10 +char TSK_FILE_TYPE[TSK_FILE_TYPE_NUM] = { + 'u', 'f', 'c', 'd', 'b', 'r', 'l', 's', 'h', 'w' +}; + +static int open_filesystem (const char *device, + TSK_IMG_INFO **img, TSK_FS_INFO **fs); +static TSK_WALK_RET_ENUM fswalk_callback (TSK_FS_FILE *fsfile, + const char *path, void *data); +static char file_type (TSK_FS_FILE *fsfile); +static int send_dirent_info (guestfs_int_tsk_dirent *dirent); +static void reply_with_tsk_error (const char *funcname); + +int +do_internal_filesystem_walk (const mountable_t *mountable) +{ + int ret = -1; + TSK_FS_INFO *fs = NULL; + TSK_IMG_INFO *img = NULL; /* Used internally by tsk_fs_dir_walk */ + int flags = TSK_FS_DIR_WALK_FLAG_ALLOC | TSK_FS_DIR_WALK_FLAG_UNALLOC | + TSK_FS_DIR_WALK_FLAG_RECURSE | TSK_FS_DIR_WALK_FLAG_NOORPHAN; + + ret = open_filesystem (mountable->device, &img, &fs); + if (ret < 0) + return ret; + + reply (NULL, NULL); /* Reply message. */ + + ret = tsk_fs_dir_walk (fs, fs->root_inum, flags, fswalk_callback, NULL); + if (ret == 0) + ret = send_file_end (0); /* File transfer end. */ + else + send_file_end (1); /* Cancel file transfer. */ + + fs->close (fs); + img->close (img); + + return ret; +} + +/* Inspect the device and initialises the img and fs structures. + * Return 0 on success, -1 on error. + */ +static int +open_filesystem (const char *device, TSK_IMG_INFO **img, TSK_FS_INFO **fs) +{ + const char *images[] = { device }; + + *img = tsk_img_open (1, images, TSK_IMG_TYPE_DETECT , 0); + if (*img == NULL) { + reply_with_tsk_error ("tsk_image_open"); + return -1; + } + + *fs = tsk_fs_open_img (*img, 0, TSK_FS_TYPE_DETECT); + if (*fs == NULL) { + reply_with_tsk_error ("tsk_fs_open_img"); + (*img)->close (*img); + return -1; + } + + return 0; +} + +/* Filesystem walk callback, it gets called on every FS node. + * Parse the node, encode it into an XDR structure and send it to the appliance. + * Return TSK_WALK_CONT on success, TSK_WALK_ERROR on error. + */ +static TSK_WALK_RET_ENUM +fswalk_callback (TSK_FS_FILE *fsfile, const char *path, void *data) +{ + int ret = 0; + CLEANUP_FREE char *fname = NULL; + struct guestfs_int_tsk_dirent dirent; + + /* Ignore ./ and ../ */ + ret = TSK_FS_ISDOT (fsfile->name->name); + if (ret != 0) + return TSK_WALK_CONT; + + /* Build the full relative path of the entry */ + ret = asprintf_nowarn (&fname, "%Q%Q", path, fsfile->name->name); + if (ret < 0) { + fprintf (stderr, "asprintf: %m"); + return TSK_WALK_ERROR; + } + + dirent.tsk_inode = fsfile->name->meta_addr; + dirent.tsk_type = file_type (fsfile); + dirent.tsk_size = (fsfile->meta != NULL) ? fsfile->meta->size : 0; + dirent.tsk_name = fname; + dirent.tsk_allocated = !(fsfile->name->flags & TSK_FS_NAME_FLAG_UNALLOC); + + ret = send_dirent_info (&dirent); + ret = (ret == 0) ? TSK_WALK_CONT : TSK_WALK_ERROR; + + return ret; +} + +/* Inspect fsfile to identify its type. */ +static char +file_type(TSK_FS_FILE *fsfile) +{ + if (fsfile->name->type < TSK_FILE_TYPE_NUM) + return TSK_FILE_TYPE[fsfile->name->type]; + else if (fsfile->meta != NULL && fsfile->meta->type < TSK_FILE_TYPE_NUM) + return TSK_FILE_TYPE[fsfile->meta->type]; + else + return 'u'; +} + +/* Serialise dirent into XDR stream and send it to the appliance. + * Return 0 on success, -1 on error. + */ +static int +send_dirent_info (guestfs_int_tsk_dirent *dirent) +{ + XDR xdr; + size_t len = 0; + CLEANUP_FREE char *buf; + + buf = malloc (GUESTFS_MAX_CHUNK_SIZE); + if (buf == NULL) { + fprintf (stderr, "malloc: %m"); + return -1; + } + + /* Serialise tsk_dirent struct. */ + xdrmem_create (&xdr, buf, GUESTFS_MAX_CHUNK_SIZE, XDR_ENCODE); + + if (!xdr_uint64_t (&xdr, &dirent->tsk_inode)) + return -1; + if (!xdr_char (&xdr, &dirent->tsk_type)) + return -1; + if (!xdr_int64_t (&xdr, &dirent->tsk_size)) + return -1; + + /* Serialise filename. */ + len = strlen (dirent->tsk_name) + 1; + if (!xdr_u_long (&xdr, &len)) + return -1; + if (!xdr_string (&xdr, &dirent->tsk_name, len)) + return -1; + + if (!xdr_uint32_t (&xdr, &dirent->tsk_allocated)) + return -1; + + /* Resize buffer to actual length. */ + len = xdr_getpos (&xdr); + xdr_destroy (&xdr); + buf = realloc (buf, len); + if (buf == NULL) { + fprintf (stderr, "realloc: %m"); + return -1; + } + + /* Send serialised tsk_dirent out. */ + return send_file_write (buf, len); +} + +/* Parse TSK error and send it to the appliance. */ +static void +reply_with_tsk_error (const char *funcname) +{ + int ret = 0; + const char *buf = NULL; + + ret = tsk_error_get_errno (); + if (ret != 0) { + buf = tsk_error_get (); + reply_with_error ("TSK function %s error: %s", funcname, buf); + } + else + reply_with_error ("TSK function %s: unknown error", funcname); +} + +int +optgroup_libtsk_available (void) +{ + return 1; +} + +#else /* !HAVE_LIBTSK */ + +OPTGROUP_LIBTSK_NOT_AVAILABLE + +#endif /* !HAVE_LIBTSK */ diff --git a/generator/actions.ml b/generator/actions.ml index e5cb939..449ffa0 100644 --- a/generator/actions.ml +++ b/generator/actions.ml @@ -12958,6 +12958,31 @@ and save it as F<filename> on the local machine. This allows to download deleted or inaccessible files." }; + { defaults with + name = "internal_filesystem_walk"; added = (1, 33, 17); + style = RErr, [Mountable "device"; FileOut "filename"], []; + proc_nr = Some 465; + visibility = VInternal; + optional = Some "libtsk"; + shortdesc = "walk through the filesystem content"; + longdesc = "Walk through the internal structures of a disk partition +(eg. F</dev/sda1>) in order to return a list of all the files +and directories stored within. + +It is not necessary to mount the disk partition to run this command. + +All entries in the filesystem are returned, excluding C<.> and +C<..>. This function can list deleted or unaccessible files. +The entries are I<not> sorted. + +If the entry is not allocated (ex: it has been deleted), +its inode, type or size might not be recovered correctly. +In such case, the inode and the size will be 0 while the type +will be unidentified 'u'. + +This call returns basic file type information about each +file." }; + ] (* Non-API meta-commands available only in guestfish. diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR index 3bb8a49..073c57b 100644 --- a/src/MAX_PROC_NR +++ b/src/MAX_PROC_NR @@ -1 +1 @@ -464 +465 -- 2.8.0.rc3

2016-04-04 12:48 GMT+03:00 Pino Toscano <ptoscano(a)redhat.com&gt;: Good spot! I'll fix it thanks! Even if they are longer than 80 chars? I didn't understand this one. I checked daemon/readdir.c and I found no asprintf examples there. The issue is that even if 'meta' is non-null, yet the value could be 0. In cases where the file has been deleted, TSK does its best to retrieve as much as it can and set to 0 the rest (same applies with inode for example, the inode is set to 0 instead of -1). The command documentation reports this "issue" (or feature?). Anyway I'll triple-check in order to be sure about it. I'll fix it thanks! I'll take a look at those. Saw the same thing with some other API, I'll remove the duplicate. Thanks for the comments.

The filesystem_walk command is the appliance's counterpart of the daemon's internal_filesystem_walk command. It writes the daemon's command output on a temporary file and parses it, deserialising the XDR formatted tsk_dirent structs. It returns to the caller the list of tsk_dirent structs generated by the internal_filesystem_walk command. Signed-off-by: Matteo Cafasso <noxdafox(a)gmail.com&gt; --- generator/actions.ml | 69 ++++++++++++++++++++++ src/Makefile.am | 1 + src/tsk.c | 162 +++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 232 insertions(+) create mode 100644 src/tsk.c diff --git a/generator/actions.ml b/generator/actions.ml index 449ffa0..9457c3f 100644 --- a/generator/actions.ml +++ b/generator/actions.ml @@ -3546,6 +3546,75 @@ The environment variable C<XDG_RUNTIME_DIR> controls the default value: If C<XDG_RUNTIME_DIR> is set, then that is the default. Else F</tmp> is the default." }; + { defaults with + name = "filesystem_walk"; added = (1, 33, 17); + style = RStructList ("dirents", "tsk_dirent"), [Mountable "device";], []; + optional = Some "libtsk"; + progress = true; cancellable = true; + shortdesc = "walk through the filesystem content"; + longdesc = "\ +Walk through the internal structures of a disk partition +(eg. F</dev/sda1>) in order to return a list of all the files +and directories stored within. + +It is not necessary to mount the disk partition to run this command. + +All entries in the filesystem are returned, excluding C<.> and +C<..>. This function can list deleted or unaccessible files. +The entries are I<not> sorted. + +If the entry is not allocated (ex: it has been deleted), +its inode, type or size might not be recovered correctly. +In such case, the inode and the size will be 0 while the type +will be unidentified 'u'. + +This call returns as well basic file type information about each +file. The C<tsk_type> field will contain one of the following characters: + +=over 4 + +=item 'b' + +Block special + +=item 'c' + +Char special + +=item 'd' + +Directory + +=item 'f' + +FIFO (named pipe) + +=item 'l' + +Symbolic link + +=item 'r' + +Regular file + +=item 's' + +Socket + +=item 'h' + +Shadow inode (Solaris) + +=item 'w' + +Whiteout inode (BSD) + +=item 'u' + +Unknown file type + +=back" }; + ] (* daemon_functions are any functions which cause some action diff --git a/src/Makefile.am b/src/Makefile.am index 3b4cd10..9f8af4c 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -130,6 +130,7 @@ libguestfs_la_SOURCES = \ structs-copy.c \ structs-free.c \ tmpdirs.c \ + tsk.c \ whole-file.c \ libguestfs.syms diff --git a/src/tsk.c b/src/tsk.c new file mode 100644 index 0000000..d77bc0a --- /dev/null +++ b/src/tsk.c @@ -0,0 +1,162 @@ +/* libguestfs + * Copyright (C) 2016 Red Hat Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <string.h> +#include <rpc/xdr.h> +#include <rpc/types.h> + +#include "full-read.h" + +#include "guestfs.h" +#include "guestfs_protocol.h" +#include "guestfs-internal.h" +#include "guestfs-internal-all.h" +#include "guestfs-internal-actions.h" + +static struct guestfs_tsk_dirent_list *parse_filesystem_walk +(guestfs_h *g, char *buf, size_t bufsize); +int deserialise_dirent_list (guestfs_h *g, char *buf, size_t bufsize, + struct guestfs_tsk_dirent_list **dirents); +static int deserialise_dirent (guestfs_h *g, XDR *xdrs, + struct guestfs_tsk_dirent *dirent); + +struct guestfs_tsk_dirent_list * +guestfs_impl_filesystem_walk (guestfs_h *g, const char *mountable) +{ + int ret = 0; + size_t size = 0; + CLEANUP_FREE char *buf = NULL; + CLEANUP_UNLINK_FREE char *tmpfile = NULL; + + ret = guestfs_int_lazy_make_tmpdir (g); + if (ret < 0) + return NULL; + + tmpfile = safe_asprintf (g, "%s/filesystem_walk%d", g->tmpdir, ++g->unique); + + ret = guestfs_internal_filesystem_walk (g, mountable, tmpfile); + if (ret < 0) + return NULL; + + ret = guestfs_int_read_whole_file (g, tmpfile, &buf, &size); + if (ret < 0) + return NULL; + + return parse_filesystem_walk (g, buf, size); /* caller frees */ +} + +/* Parse buf content and return dirents list. + * Return a list of tsk_dirent on success, NULL on error. + */ +static struct guestfs_tsk_dirent_list * +parse_filesystem_walk (guestfs_h *g, char *buf, size_t bufsize) +{ + int ret = 0; + struct guestfs_tsk_dirent_list *dirents = NULL; + + /* Initialise results array. */ + dirents = safe_malloc (g, sizeof (struct guestfs_tsk_dirent_list)); + dirents->len = 8; + dirents->val = safe_malloc (g, dirents->len * + sizeof (struct guestfs_tsk_dirent)); + + /* Deserialise buffer into dirent list. */ + ret = deserialise_dirent_list (g, buf, bufsize, &dirents); + if (ret < 0) { + guestfs_free_tsk_dirent_list (dirents); + return NULL; + } + + /* Resize the array to correct number of entries. */ + dirents->len = ret; + dirents->val = safe_realloc (g, dirents->val, + dirents->len * + sizeof (struct guestfs_tsk_dirent)); + + return dirents; +} + +/* Deserialise buf content and populate the dirent list. + * Return the number of deserialised dirents, -1 on error. + */ +int +deserialise_dirent_list (guestfs_h *g, char *buf, size_t bufsize, + struct guestfs_tsk_dirent_list **dirents) +{ + XDR xdr; + int ret = 0; + uint32_t index = 0; + + xdrmem_create (&xdr, buf, bufsize, XDR_DECODE); + + for (index = 0; xdr_getpos (&xdr) < bufsize; index++) { + if (index == (*dirents)->len) { + (*dirents)->len = 2 * (*dirents)->len; + (*dirents)->val = safe_realloc (g, (*dirents)->val, + (*dirents)->len * + sizeof (struct guestfs_tsk_dirent)); + } + + ret = deserialise_dirent (g, &xdr, &(*dirents)->val[index]); + if (ret < 0) + break; + } + + xdr_destroy (&xdr); + + return index; +} + +/* Parse a single XDR encoded tsk_dirent. + * Return 0 on success, -1 on error. + */ +static int +deserialise_dirent (guestfs_h *g, XDR *xdrs, struct guestfs_tsk_dirent *dirent) +{ + size_t len = 0; + CLEANUP_FREE char *buf = NULL; + + /* Deserialise tsk_dirent struct. */ + if (!xdr_uint64_t (xdrs, &dirent->tsk_inode)) + return -1; + if (!xdr_char (xdrs, &dirent->tsk_type)) + return -1; + if (!xdr_int64_t (xdrs, &dirent->tsk_size)) + return -1; + + /* Deserialise filename. */ + if (!xdr_u_long (xdrs, &len)) + return -1; + buf = safe_malloc (g, len); + if (!xdr_string (xdrs, &buf, len)) + return -1; + dirent->tsk_name = safe_strndup(g, buf, len); + + if (!xdr_uint32_t (xdrs, &dirent->tsk_allocated)) + return -1; + + return 0; +} -- 2.8.0.rc3

2016-04-04 13:09 GMT+03:00 Pino Toscano <ptoscano(a)redhat.com&gt;: If I then run the command in guestfish I get plenty of empty structs.

The tests check that the filesystem_walk command is able to retrieve information regarding both existing and deleted files. A NTFS image is used as Ext3+ filesystems deletion is more aggressive in terms of metadata removal. Signed-off-by: Matteo Cafasso <noxdafox(a)gmail.com&gt; --- tests/tsk/Makefile.am | 3 +- tests/tsk/test-filesystem-walk.sh | 62 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 64 insertions(+), 1 deletion(-) create mode 100755 tests/tsk/test-filesystem-walk.sh diff --git a/tests/tsk/Makefile.am b/tests/tsk/Makefile.am index 0cd7c03..f9b2fef 100644 --- a/tests/tsk/Makefile.am +++ b/tests/tsk/Makefile.am @@ -18,7 +18,8 @@ include $(top_srcdir)/subdir-rules.mk TESTS = \ - test-download-inode.sh + test-download-inode.sh \ + test-filesystem-walk.sh TESTS_ENVIRONMENT = $(top_builddir)/run --test diff --git a/tests/tsk/test-filesystem-walk.sh b/tests/tsk/test-filesystem-walk.sh new file mode 100755 index 0000000..8df1d0f --- /dev/null +++ b/tests/tsk/test-filesystem-walk.sh @@ -0,0 +1,62 @@ +#!/bin/bash - +# libguestfs +# Copyright (C) 2016 Red Hat Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +# Test the filesystem-walk command. + +if [ -n "$SKIP_TEST_FILESYSTEM_WALK_SH" ]; then + echo "$0: test skipped because environment variable is set." + exit 77 +fi + +# Skip if TSK is not supported by the appliance. +if ! guestfish add /dev/null : run : available "libtsk"; then + echo "$0: skipped because TSK is not available in the appliance" + exit 77 +fi + +if [ ! -s ../../test-data/phony-guests/windows.img ]; then + echo "$0: skipped because windows.img is zero-sized" + exit 77 +fi + +# create and delete a file then list the filesystem content +output=$(guestfish --ro -a ../../test-data/phony-guests/windows.img \ + run : \ + mount /dev/sda2 / : \ + write /test.txt "foobar" : \ + rm /test.txt : \ + umount / : \ + filesystem-walk /dev/sda2) + +# test $MFT is in the list +echo $output | grep -q "{ tsk_inode: 0 tsk_type: r tsk_size: .* tsk_name: ..MFT tsk_allocated: 1 }" +if [ $? != 0 ]; then + echo "$0: \$MFT not found in files list." + echo "File list:" + echo $output + exit 1 +fi + +# test deleted file is in the list +echo $output | grep -q "{ tsk_inode: .* tsk_type: [ru] tsk_size: [06] tsk_name: test.txt tsk_allocated: 0 }" +if [ $? != 0 ]; then + echo "$0: /test.txt not found in files list." + echo "File list:" + echo $output + exit 1 +fi -- 2.8.0.rc3