The internal_find_block command searches all entries referring to the given filesystem data block and returns a tsk_dirent structure for each of them. For filesystems such as NTFS which do not delete the block mapping when removing files, it is possible to get multiple non-allocated entries for the same block. 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/tsk.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++ generator/actions.ml | 9 ++++++ src/MAX_PROC_NR | 2 +- 3 files changed, 99 insertions(+), 1 deletion(-) diff --git a/daemon/tsk.c b/daemon/tsk.c index af803d7..6ac3952 100644 --- a/daemon/tsk.c +++ b/daemon/tsk.c @@ -42,9 +42,16 @@ enum tsk_dirent_flags { DIRENT_COMPRESSED = 0x04 }; +typedef struct { + int found; + uint64_t block; +} findblk_data; + static int open_filesystem (const char *, TSK_IMG_INFO **, TSK_FS_INFO **); static TSK_WALK_RET_ENUM fswalk_callback (TSK_FS_FILE *, const char *, void *); static TSK_WALK_RET_ENUM findino_callback (TSK_FS_FILE *, const char *, void *); +static TSK_WALK_RET_ENUM findblk_callback (TSK_FS_FILE *, const char *, void *); +static TSK_WALK_RET_ENUM attrwalk_callback (TSK_FS_FILE *, TSK_OFF_T , TSK_DADDR_T , char *, size_t , TSK_FS_BLOCK_FLAG_ENUM , void *); static int send_dirent_info (TSK_FS_FILE *, const char *); static char file_type (TSK_FS_FILE *); static int file_flags (TSK_FS_FILE *fsfile); @@ -109,6 +116,36 @@ do_internal_find_inode (const mountable_t *mountable, int64_t inode) return ret; } +int +do_internal_find_block (const mountable_t *mountable, int64_t block) +{ + int ret = -1; + TSK_FS_INFO *fs = NULL; + TSK_IMG_INFO *img = NULL; /* Used internally by tsk_fs_dir_walk */ + const 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, + findblk_callback, (void *) &block); + 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. */ @@ -172,6 +209,58 @@ findino_callback (TSK_FS_FILE *fsfile, const char *path, void *data) return (ret == 0) ? TSK_WALK_CONT : TSK_WALK_ERROR; } +/* Find block, it gets called on every FS node. + * + * Return TSK_WALK_CONT on success, TSK_WALK_ERROR on error. + */ +static TSK_WALK_RET_ENUM +findblk_callback (TSK_FS_FILE *fsfile, const char *path, void *data) +{ + findblk_data blkdata; + const TSK_FS_ATTR *fsattr = NULL; + int ret = 0, count = 0, index = 0; + uint64_t *block = (uint64_t *) data; + const int flags = TSK_FS_FILE_WALK_FLAG_AONLY | TSK_FS_FILE_WALK_FLAG_SLACK; + + if (entry_is_dot (fsfile)) + return TSK_WALK_CONT; + + blkdata.found = 0; + blkdata.block = *block; + + /* Retrieve block list */ + count = tsk_fs_file_attr_getsize (fsfile); + + for (index = 0; index < count; index++) { + fsattr = tsk_fs_file_attr_get_idx (fsfile, index); + + if (fsattr != NULL && fsattr->flags & TSK_FS_ATTR_NONRES) + tsk_fs_attr_walk (fsattr, flags, attrwalk_callback, (void*) &blkdata); + } + + if (blkdata.found) + ret = send_dirent_info (fsfile, path); + + return (ret == 0) ? TSK_WALK_CONT : TSK_WALK_ERROR; +} + +/* Attribute walk, searches the given block within the FS node attributes. */ +static TSK_WALK_RET_ENUM +attrwalk_callback (TSK_FS_FILE *fsfile, TSK_OFF_T offset, + TSK_DADDR_T blkaddr, char *buf, size_t size, + TSK_FS_BLOCK_FLAG_ENUM flags, void *data) +{ + findblk_data *blkdata = (findblk_data *) data; + + if (blkaddr == blkdata->block) { + blkdata->found = 1; + + return TSK_WALK_STOP; + } + + return TSK_WALK_CONT; +} + /* Extract the information from the entry, serialize and send it out. * Return 0 on success, -1 on error. */ diff --git a/generator/actions.ml b/generator/actions.ml index 91a1819..b38a30f 100644 --- a/generator/actions.ml +++ b/generator/actions.ml @@ -13253,6 +13253,15 @@ is removed." }; shortdesc = "search the entries associated to the given inode"; longdesc = "Internal function for find_inode." }; + { defaults with + name = "internal_find_block"; added = (1, 35, 6); + style = RErr, [Mountable "device"; Int64 "block"; FileOut "filename";], []; + proc_nr = Some 471; + visibility = VInternal; + optional = Some "libtsk"; + shortdesc = "search the entries associated to the given block"; + longdesc = "Internal function for find_block." }; + ] (* Non-API meta-commands available only in guestfish. diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR index 5f476b6..c305aa5 100644 --- a/src/MAX_PROC_NR +++ b/src/MAX_PROC_NR @@ -1 +1 @@ -470 +471 -- 2.9.3

Library's counterpart of the daemon's internal_find_block 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_find_block command. Signed-off-by: Matteo Cafasso <noxdafox(a)gmail.com&gt; --- generator/actions.ml | 16 ++++++++++++++++ src/tsk.c | 26 ++++++++++++++++++++++++++ 2 files changed, 42 insertions(+) diff --git a/generator/actions.ml b/generator/actions.ml index b38a30f..8947551 100644 --- a/generator/actions.ml +++ b/generator/actions.ml @@ -3729,6 +3729,22 @@ Searches all the entries associated with the given inode. For each entry, a C<tsk_dirent> structure is returned. See C<filesystem_walk> for more information about C<tsk_dirent> structures." }; + { defaults with + name = "find_block"; added = (1, 35, 6); + style = RStructList ("dirents", "tsk_dirent"), [Mountable "device"; Int64 "block";], []; + optional = Some "libtsk"; + progress = true; cancellable = true; + shortdesc = "search the entries referring to the given data block"; + longdesc = "\ +Searches all the entries referring to the given data block. + +Certain filesystems preserve the block mapping when deleting a file. +Therefore, it is possible to see multiple deleted files referring +to the same block. + +For each entry, a C<tsk_dirent> structure is returned. +See C<filesystem_walk> for more information about C<tsk_dirent> structures." }; + ] (* daemon_functions are any functions which cause some action diff --git a/src/tsk.c b/src/tsk.c index d3da834..6b1b29c 100644 --- a/src/tsk.c +++ b/src/tsk.c @@ -89,6 +89,32 @@ guestfs_impl_find_inode (guestfs_h *g, const char *mountable, int64_t inode) return parse_dirent_file (g, fp); /* caller frees */ } +struct guestfs_tsk_dirent_list * +guestfs_impl_find_block (guestfs_h *g, const char *mountable, int64_t block) +{ + int ret = 0; + CLEANUP_FCLOSE FILE *fp = NULL; + CLEANUP_UNLINK_FREE char *tmpfile = NULL; + + ret = guestfs_int_lazy_make_tmpdir (g); + if (ret < 0) + return NULL; + + tmpfile = safe_asprintf (g, "%s/find_block%d", g->tmpdir, ++g->unique); + + ret = guestfs_internal_find_block (g, mountable, block, tmpfile); + if (ret < 0) + return NULL; + + fp = fopen (tmpfile, "r"); + if (fp == NULL) { + perrorf (g, "fopen: %s", tmpfile); + return NULL; + } + + return parse_dirent_file (g, fp); /* caller frees */ +} + /* Parse the file content and return dirents list. * Return a list of tsk_dirent on success, NULL on error. */ -- 2.9.3

Removed duplicated code. Signed-off-by: Matteo Cafasso <noxdafox(a)gmail.com&gt; --- src/tsk.c | 69 ++++++++++++++++++++++++++------------------------------------- 1 file changed, 28 insertions(+), 41 deletions(-) diff --git a/src/tsk.c b/src/tsk.c index 6b1b29c..8e6d266 100644 --- a/src/tsk.c +++ b/src/tsk.c @@ -34,96 +34,71 @@ #include "guestfs-internal-all.h" #include "guestfs-internal-actions.h" -static struct guestfs_tsk_dirent_list *parse_dirent_file (guestfs_h *, FILE *); +static struct guestfs_tsk_dirent_list *parse_dirent_file (guestfs_h *, const char *); static int deserialise_dirent_list (guestfs_h *, FILE *, struct guestfs_tsk_dirent_list *); +static char *make_temp_file (guestfs_h *, const char *); struct guestfs_tsk_dirent_list * guestfs_impl_filesystem_walk (guestfs_h *g, const char *mountable) { int ret = 0; - CLEANUP_FCLOSE FILE *fp = 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); + tmpfile = make_temp_file (g, "filesystem_walk"); ret = guestfs_internal_filesystem_walk (g, mountable, tmpfile); if (ret < 0) return NULL; - fp = fopen (tmpfile, "r"); - if (fp == NULL) { - perrorf (g, "fopen: %s", tmpfile); - return NULL; - } - - return parse_dirent_file (g, fp); /* caller frees */ + return parse_dirent_file (g, tmpfile); /* caller frees */ } struct guestfs_tsk_dirent_list * guestfs_impl_find_inode (guestfs_h *g, const char *mountable, int64_t inode) { int ret = 0; - CLEANUP_FCLOSE FILE *fp = NULL; CLEANUP_UNLINK_FREE char *tmpfile = NULL; - ret = guestfs_int_lazy_make_tmpdir (g); - if (ret < 0) - return NULL; - - tmpfile = safe_asprintf (g, "%s/find_inode%d", g->tmpdir, ++g->unique); + tmpfile = make_temp_file (g, "find_inode"); ret = guestfs_internal_find_inode (g, mountable, inode, tmpfile); if (ret < 0) return NULL; - fp = fopen (tmpfile, "r"); - if (fp == NULL) { - perrorf (g, "fopen: %s", tmpfile); - return NULL; - } - - return parse_dirent_file (g, fp); /* caller frees */ + return parse_dirent_file (g, tmpfile); /* caller frees */ } struct guestfs_tsk_dirent_list * guestfs_impl_find_block (guestfs_h *g, const char *mountable, int64_t block) { int ret = 0; - CLEANUP_FCLOSE FILE *fp = NULL; CLEANUP_UNLINK_FREE char *tmpfile = NULL; - ret = guestfs_int_lazy_make_tmpdir (g); - if (ret < 0) - return NULL; - - tmpfile = safe_asprintf (g, "%s/find_block%d", g->tmpdir, ++g->unique); + tmpfile = make_temp_file (g, "find_block"); ret = guestfs_internal_find_block (g, mountable, block, tmpfile); if (ret < 0) return NULL; - fp = fopen (tmpfile, "r"); - if (fp == NULL) { - perrorf (g, "fopen: %s", tmpfile); - return NULL; - } - - return parse_dirent_file (g, fp); /* caller frees */ + return parse_dirent_file (g, tmpfile); /* caller frees */ } /* Parse the file content and return dirents list. * Return a list of tsk_dirent on success, NULL on error. */ static struct guestfs_tsk_dirent_list * -parse_dirent_file (guestfs_h *g, FILE *fp) +parse_dirent_file (guestfs_h *g, const char *tmpfile) { int ret = 0; + CLEANUP_FCLOSE FILE *fp = NULL; struct guestfs_tsk_dirent_list *dirents = NULL; + fp = fopen (tmpfile, "r"); + if (fp == NULL) { + perrorf (g, "fopen: %s", tmpfile); + return NULL; + } + /* Initialise results array. */ dirents = safe_malloc (g, sizeof (*dirents)); dirents->len = 8; @@ -178,3 +153,15 @@ deserialise_dirent_list (guestfs_h *g, FILE *fp, return ret ? 0 : -1; } + +static char * +make_temp_file (guestfs_h *g, const char *name) +{ + int ret = 0; + + ret = guestfs_int_lazy_make_tmpdir (g); + if (ret < 0) + return NULL; + + return safe_asprintf (g, "%s/%s%d", g->tmpdir, name, ++g->unique); +} -- 2.9.3