Re: [Libguestfs] [PATCH] added ntfscat_i api

On Mon, Feb 22, 2016 at 07:23:45PM +0200, noxdafox wrote: > On 22/02/16 17:26, Richard W.M. Jones wrote: >> On Sun, Feb 21, 2016 at 11:22:23PM +0200, Matteo Cafasso wrote: >>> Adding ntfscat_i command for downloading files based on their inode number. >>> >>> This allows the dowload of files unaccessible otherwise from a NTFS guest disk image. >> The patch seems fine, but it really needs a test otherwise this >> feature could silently break. > I was thinking the same but I stumbled over an issue which prevented > me from running the tests. > I'm not sure this is the right place where to discuss the problem > but here's few lines about it. > > make blank-disk.img blank-part.img blank-fs.img blank-bootroot.img > blank-bootrootlv.img debian.img fedora.img fedora-md1.img > fedora-md2.img fedora-btrfs.img ubuntu.img archlinux.img coreos.img > windows.img guests-all-good.xml > make[3]: Entering directory > '/home/noxdafox/development/libguestfs/test-data/phony-guests' > make[3]: 'blank-disk.img' is up to date. > make[3]: 'blank-part.img' is up to date. > make[3]: 'blank-fs.img' is up to date. > make[3]: 'blank-bootroot.img' is up to date. > make[3]: 'blank-bootrootlv.img' is up to date. > make[3]: 'debian.img' is up to date. > rm -f fedora-name.db fedora-name.db-t > no fedora-name.db-t < fedora-name.db.txt > /bin/bash: no: command not found What happens here is it's trying to run ``$(DB_LOAD) fedora-name.db-t'' but the db_load program wasn't found by your configure. I think you need to install whatever is the db4-utils (Berkeley DB 4) on your OS. Alternately you can grab the pre-built databases from a recent tarball, since we distribute this stuff in the tarball so it doesn't need to be rebuilt for most end users. Rich.

> Makefile:1793: recipe for target 'fedora-name.db' failed > make[3]: *** [fedora-name.db] Error 127 > > Searching around it seems some dependency is missing but ./configure > is not helping me to find which one. > >> Have a look at the tests/ntfsclone/ subdirectory for the general idea. > This was also another issue, I was not sure ntfs was supported by > the test suite and I didn't find any documentation about it. I'll > take a look at these ones. >> One problem with writing the test (indeed, with the general idea) is >> how do you discover which inode numbers can be downloaded? Does NTFS >> have some standard inode numbers for things like the MFT? > The $MFT file has alway 0 as index number. >> Rich. >> >>> --- >>> daemon/ntfs.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++ >>> generator/actions.ml | 15 +++++++++++++ >>> 2 files changed, 77 insertions(+) >>> >>> diff --git a/daemon/ntfs.c b/daemon/ntfs.c >>> index 568899e..58f62fa 100644 >>> --- a/daemon/ntfs.c >>> +++ b/daemon/ntfs.c >>> @@ -266,3 +266,65 @@ do_ntfsfix (const char *device, int clearbadsectors) >>> >>> return 0; >>> } >>> + >>> +int >>> +do_ntfscat_i (const mountable_t *mountable, int64_t inode) >>> +{ >>> + int r; >>> + FILE *fp; >>> + CLEANUP_FREE char *cmd = NULL; >>> + char buffer[GUESTFS_MAX_CHUNK_SIZE]; >>> + >>> + /* Inode must be greater than 0 */ >>> + if (inode < 0) { >>> + reply_with_error("Inode must be greater than 0"); >>> + return -1; >>> + } >>> + >>> + /* Construct the command. */ >>> + if (asprintf_nowarn (&cmd, "ntfscat -i %ld %s", >>> + inode, mountable->device) == -1) { >>> + reply_with_perror ("asprintf"); >>> + return -1; >>> + } >>> + >>> + if (verbose) >>> + fprintf (stderr, "%s\n", cmd); >>> + >>> + fp = popen (cmd, "r"); >>> + if (fp == NULL) { >>> + reply_with_perror ("%s", cmd); >>> + return -1; >>> + } >>> + >>> + /* Now we must send the reply message, before the file contents. After >>> + * this there is no opportunity in the protocol to send any error >>> + * message back. Instead we can only cancel the transfer. >>> + */ >>> + reply (NULL, NULL); >>> + >>> + while ((r = fread (buffer, 1, sizeof buffer, fp)) > 0) { >>> + if (send_file_write (buffer, r) < 0) { >>> + pclose (fp); >>> + return -1; >>> + } >>> + } >>> + >>> + if (ferror (fp)) { >>> + fprintf (stderr, "fread: %ld: %m\n", inode); >>> + send_file_end (1); /* Cancel. */ >>> + pclose (fp); >>> + return -1; >>> + } >>> + >>> + if (pclose (fp) != 0) { >>> + fprintf (stderr, "pclose: %ld: %m\n", inode); >>> + send_file_end (1); /* Cancel. */ >>> + return -1; >>> + } >>> + >>> + if (send_file_end (0)) /* Normal end of file. */ >>> + return -1; >>> + >>> + return 0; >>> +} >>> diff --git a/generator/actions.ml b/generator/actions.ml >>> index eb45392..18418aa 100644 >>> --- a/generator/actions.ml >>> +++ b/generator/actions.ml >>> @@ -12891,6 +12891,21 @@ This is equivalent to C<sgdisk -e>. >>> >>> See also L<sgdisk(8)>." }; >>> >>> + { defaults with >>> + name = "ntfscat_i"; added = (1, 33, 12); >>> + style = RErr, [Mountable "device"; Int64 "inode"; FileOut "filename"], []; >>> + proc_nr = Some 463; >>> + progress = true; cancellable = true; >>> + shortdesc = "download a file to the local machine given its inode"; >>> + longdesc = "\ >>> +Download a file given its inode from a NTFS filesystem and save it as F<filename> >>> +on the local machine. >>> + >>> +This allows to download some otherwise unaccessible files such as the ones >>> +within the $Extend folder. >>> + >>> +F<filename> can also be a named pipe." }; >>> + >>> ] >>> >>> (* Non-API meta-commands available only in guestfish. >>> -- >>> 2.7.0