added icat API to retrieve deleted or inaccessible files

Signed-off-by: Matteo Cafasso <noxdafox@gmail.com>

daemon/Makefile.am

@@ -179,6 +179,7 @@ guestfsd_SOURCES = \
 	syslinux.c \
 	tar.c \
 	truncate.c \
+	tsk.c \
 	umask.c \
 	upload.c \
 	utimens.c \

daemon/tsk.c

@@ -0,0 +1,114 @@
+/* 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 "guestfs_protocol.h"
+#include "daemon.h"
+#include "actions.h"
+#include "optgroups.h"
+
+static int file_out (const char *cmd);
+
+GUESTFSD_EXT_CMD(str_tsk_probe, icat);
+
+int
+optgroup_icat_available (void)
+{
+  return prog_exists (str_tsk_probe);
+}
+
+int
+do_icat (const mountable_t *mountable, int64_t inode)
+{
+  CLEANUP_FREE char *cmd = NULL;
+
+  /* Inode must be greater than 0 */
+  if (inode < 0) {
+    reply_with_error ("inode must be >= 0");
+    return -1;
+  }
+
+  /* Construct the command. */
+  if (asprintf (&cmd, "icat -r %s %" PRIi64, mountable->device, inode) == -1) {
+    reply_with_perror ("asprintf");
+    return -1;
+  }
+
+  return file_out (cmd);
+}
+
+static int
+file_out (const char *cmd)
+{
+  int r;
+  FILE *fp;
+  CLEANUP_FREE char *buffer = NULL;
+
+  if (verbose)
+    fprintf (stderr, "%s\n", cmd);
+
+  buffer = malloc (GUESTFS_MAX_CHUNK_SIZE);
+  if (buffer == NULL) {
+    reply_with_perror ("malloc");
+    return -1;
+  }
+
+  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: %m");
+    send_file_end (1);		/* Cancel. */
+    pclose (fp);
+    return -1;
+  }
+
+  if (pclose (fp) != 0) {
+    fprintf (stderr, "pclose: %m");
+    send_file_end (1);		/* Cancel. */
+    return -1;
+  }
+
+  if (send_file_end (0))	/* Normal end of file. */
+    return -1;
+
+  return 0;
+}

generator/actions.ml

@@ -12919,6 +12919,19 @@ within the C<$Extend> folder.
 The filesystem from which to extract the file must be unmounted,
 otherwise the call will fail." };
 
+  { defaults with
+    name = "icat"; added = (1, 33, 14);
+    style = RErr, [Mountable "device"; Int64 "inode"; FileOut "filename"], [];
+    proc_nr = Some 464;
+    optional = Some "icat";
+    progress = true; cancellable = true;
+    shortdesc = "download a file to the local machine given its inode";
+    longdesc = "\
+Download a file given its inode from the disk partition (eg. F</dev/sda1>)
+and save it as F<filename> on the local machine.
+
+This allows to download deleted or inaccessible files." };
+
 ]
 
 (* Non-API meta-commands available only in guestfish.

po/POTFILES

@@ -108,6 +108,7 @@ daemon/sync.c
 daemon/syslinux.c
 daemon/tar.c
 daemon/truncate.c
+daemon/tsk.c
 daemon/umask.c
 daemon/upload.c
 daemon/utimens.c

src/MAX_PROC_NR

@@ -1 +1 @@
-463
+464