/* libguestfs - guestfish and guestmount shared option parsing
 * Copyright (C) 2010 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 <string.h>

#include "c-ctype.h"

#include "guestfs.h"

#include "options.h"

/* Global that saves the root device between inspect_mount and
 * print_inspect_prompt.
 */
static char *root = NULL;

static void
free_strings (char **argv)
{
  int argc;

  for (argc = 0; argv[argc] != NULL; ++argc)
    free (argv[argc]);
  free (argv);
}

static size_t
count_strings (char *const *argv)
{
  size_t i;

  for (i = 0; argv[i]; ++i)
    ;
  return i;
}

static int
compare_keys_len (const void *p1, const void *p2)
{
  const char *key1 = * (char * const *) p1;
  const char *key2 = * (char * const *) p2;
  return strlen (key1) - strlen (key2);
}

static int
compare_keys (const void *p1, const void *p2)
{
  const char *key1 = * (char * const *) p1;
  const char *key2 = * (char * const *) p2;
  return strcasecmp (key1, key2);
}

/* This function implements the -i option. */
void
inspect_mount (void)
{
  if (live) {
    fprintf (stderr, _("%s: don't use --live and -i options together\n"),
             program_name);
    exit (EXIT_FAILURE);
  }

  inspect_do_decrypt ();

  char **roots = guestfs_inspect_os (g);
  if (roots == NULL)
    exit (EXIT_FAILURE);

  if (roots[0] == NULL) {
    fprintf (stderr,
      _("%s: no operating system was found on this disk\n"
        "\n"
        "If using guestfish '-i' option, remove this option and instead\n"
        "use the commands 'run' followed by 'list-filesystems'.\n"
        "You can then mount filesystems you want by hand using the\n"
        "'mount' or 'mount-ro' command.\n"
        "\n"
        "If using guestmount '-i', remove this option and choose the\n"
        "filesystem(s) you want to see by manually adding '-m' option(s).\n"
        "Use 'virt-filesystems' to see what filesystems are available.\n"
        "\n"
        "If using other virt tools, this disk image won't work\n"
        "with these tools.  Use the guestfish equivalent commands\n"
        "(see the virt tool manual page).\n"),
             program_name);
    free_strings (roots);
    exit (EXIT_FAILURE);
  }

  if (roots[1] != NULL) {
    fprintf (stderr,
      _("%s: multi-boot operating systems are not supported\n"
        "\n"
        "If using guestfish '-i' option, remove this option and instead\n"
        "use the commands 'run' followed by 'list-filesystems'.\n"
        "You can then mount filesystems you want by hand using the\n"
        "'mount' or 'mount-ro' command.\n"
        "\n"
        "If using guestmount '-i', remove this option and choose the\n"
        "filesystem(s) you want to see by manually adding '-m' option(s).\n"
        "Use 'virt-filesystems' to see what filesystems are available.\n"
        "\n"
        "If using other virt tools, multi-boot operating systems won't work\n"
        "with these tools.  Use the guestfish equivalent commands\n"
        "(see the virt tool manual page).\n"),
             program_name);
    free_strings (roots);
    exit (EXIT_FAILURE);
  }

  root = roots[0];
  free (roots);

  inspect_mount_root (root);
}

void
inspect_mount_root (const char *root)
{
  char **mountpoints = guestfs_inspect_get_mountpoints (g, root);
  if (mountpoints == NULL)
    exit (EXIT_FAILURE);

  /* Sort by key length, shortest key first, so that we end up
   * mounting the filesystems in the correct order.
   */
  qsort (mountpoints, count_strings (mountpoints) / 2, 2 * sizeof (char *),
         compare_keys_len);

  size_t i;
  size_t mount_errors = 0;
  for (i = 0; mountpoints[i] != NULL; i += 2) {
    int r;
    if (!read_only)
      r = guestfs_mount_options (g, "", mountpoints[i+1], mountpoints[i]);
    else
      r = guestfs_mount_ro (g, mountpoints[i+1], mountpoints[i]);
    if (r == -1) {
      /* If the "/" filesystem could not be mounted, give up, else
       * just count the errors and print a warning.
       */
      if (STREQ (mountpoints[i], "/"))
        exit (EXIT_FAILURE);
      mount_errors++;
    }
  }

  free_strings (mountpoints);

  if (mount_errors)
    fprintf (stderr, _("%s: some filesystems could not be mounted (ignored)\n"),
             program_name);
}

/* This function is called only if the above function was called,
 * and only after we've printed the prompt in interactive mode.
 */
void
print_inspect_prompt (void)
{
  char *name = guestfs_inspect_get_product_name (g, root);
  if (name && STRNEQ (name, "unknown"))
    printf (_("Operating system: %s\n"), name);
  free (name);

  char **mountpoints = guestfs_inspect_get_mountpoints (g, root);
  if (mountpoints == NULL)
    return;

  /* Sort by key. */
  qsort (mountpoints, count_strings (mountpoints) / 2, 2 * sizeof (char *),
         compare_keys);

  size_t i;
  for (i = 0; mountpoints[i] != NULL; i += 2)
    printf (_("%s mounted on %s\n"), mountpoints[i+1], mountpoints[i]);

  free_strings (mountpoints);
}

/* Make a LUKS map name from the partition name,
 * eg "/dev/vda2" => "luksvda2"
 */
static void
make_mapname (const char *device, char *mapname, size_t len)
{
  size_t i = 0;

  if (len < 5)
    abort ();
  strcpy (mapname, "luks");
  mapname += 4;
  len -= 4;

  if (STRPREFIX (device, "/dev/"))
    i = 5;

  for (; device[i] != '\0' && len >= 1; ++i) {
    if (c_isalnum (device[i])) {
      *mapname++ = device[i];
      len--;
    }
  }

  *mapname = '\0';
}

/* Simple implementation of decryption: look for any crypto_LUKS
 * partitions and decrypt them, then rescan for VGs.  This only works
 * for Fedora whole-disk encryption.  WIP to make this work for other
 * encryption schemes.
 */
void
inspect_do_decrypt (void)
{
  char **partitions = guestfs_list_partitions (g);
  if (partitions == NULL)
    exit (EXIT_FAILURE);

  int need_rescan = 0;
  size_t i;
  for (i = 0; partitions[i] != NULL; ++i) {
    char *type = guestfs_vfs_type (g, partitions[i]);
    if (type && STREQ (type, "crypto_LUKS")) {
      char mapname[32];
      make_mapname (partitions[i], mapname, sizeof mapname);

      char *key = read_key (partitions[i]);
      /* XXX Should we call guestfs_luks_open_ro if readonly flag
       * is set?  This might break 'mount_ro'.
       */
      if (guestfs_luks_open (g, partitions[i], key, mapname) == -1)
        exit (EXIT_FAILURE);

      free (key);

      need_rescan = 1;
    }
    free (type);
  }

  free_strings (partitions);

  if (need_rescan) {
    if (guestfs_vgscan (g) == -1)
      exit (EXIT_FAILURE);
    if (guestfs_vg_activate_all (g, 1) == -1)
      exit (EXIT_FAILURE);
  }
}