/*

 * Copyright (C) 2008 Karel Zak <kzak@redhat.com>

 *

 * This file may be redistributed under the terms of the

 * GNU Lesser General Public License.

 */

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <unistd.h>

#include <fcntl.h>

#include <time.h>

#include <sys/time.h>

#include <sys/types.h>

#ifdef HAVE_SYS_STAT_H

#include <sys/stat.h>

#endif

#ifdef HAVE_ERRNO_H

#include <errno.h>

#endif

#include "blkidP.h"

#include "sysfs.h"

static void blkid_probe_to_tags(blkid_probe pr, blkid_dev dev)

{

  const char *data;

  const char *name;

  int nvals, n;

  size_t len;

  nvals = blkid_probe_numof_values(pr);

  for (n = 0; n < nvals; n++) {

    if (blkid_probe_get_value(pr, n, &name, &data, &len) != 0)

      continue;

    if (strncmp(name, "PART_ENTRY_", 11) == 0) {

      if (strcmp(name, "PART_ENTRY_UUID") == 0)

        blkid_set_tag(dev, "PARTUUID", data, len);

      else if (strcmp(name, "PART_ENTRY_NAME") == 0)

        blkid_set_tag(dev, "PARTLABEL", data, len);

    } else if (!strstr(name, "_ID")) {

      /* superblock UUID, LABEL, ...

       * but not {SYSTEM,APPLICATION,..._ID} */

      blkid_set_tag(dev, name, data, len);

    }

  }

}

/*

 * Verify that the data in dev is consistent with what is on the actual

 * block device (using the devname field only).  Normally this will be

 * called when finding items in the cache, but for long running processes

 * is also desirable to revalidate an item before use.

 *

 * If we are unable to revalidate the data, we return the old data and

 * do not set the BLKID_BID_FL_VERIFIED flag on it.

 */

blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)

{

  blkid_tag_iterate iter;

  const char *type, *value;

  struct stat st;

  time_t diff, now;

  int fd;

  if (!dev || !cache)

    return NULL;

  now = time(NULL);

  diff = (uintmax_t)now - dev->bid_time;

  if (stat(dev->bid_name, &st) < 0) {

    DBG(PROBE, ul_debug("blkid_verify: error %m (%d) while "

         "trying to stat %s", errno,

         dev->bid_name));

  open_err:

    if ((errno == EPERM) || (errno == EACCES) || (errno == ENOENT)) {

      /* We don't have read permission, just return cache data. */

      DBG(PROBE, ul_debug("returning unverified data for %s",

            dev->bid_name));

      return dev;

    }

    blkid_free_dev(dev);

    return NULL;

  }

  if (now >= dev->bid_time &&

#ifdef HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC

      (st.st_mtime < dev->bid_time ||

          (st.st_mtime == dev->bid_time &&

     st.st_mtim.tv_nsec / 1000 <= dev->bid_utime)) &&

#else

      st.st_mtime <= dev->bid_time &&

#endif

      diff >= 0 && diff < BLKID_PROBE_MIN) {

    dev->bid_flags |= BLKID_BID_FL_VERIFIED;

    return dev;

  }

#ifndef HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC

  DBG(PROBE, ul_debug("need to revalidate %s (cache time %lld, stat time %lld,\t"

       "time since last check %lld)",

       dev->bid_name, (long long)dev->bid_time,

       (long long)st.st_mtime, (long long)diff));

#else

  DBG(PROBE, ul_debug("need to revalidate %s (cache time %lld.%lld, stat time %lld.%lld,\t"

       "time since last check %lld)",

       dev->bid_name,

       (long long)dev->bid_time, (long long)dev->bid_utime,

       (long long)st.st_mtime, (long long)st.st_mtim.tv_nsec / 1000,

       (long long)diff));

#endif

  if (sysfs_devno_is_dm_private(st.st_rdev, NULL)) {

    blkid_free_dev(dev);

    return NULL;

  }

  if (!cache->probe) {

    cache->probe = blkid_new_probe();

    if (!cache->probe) {

      blkid_free_dev(dev);

      return NULL;

    }

  }

  fd = open(dev->bid_name, O_RDONLY|O_CLOEXEC|O_NONBLOCK);

  if (fd < 0) {

    DBG(PROBE, ul_debug("blkid_verify: error %m (%d) while "

          "opening %s", errno,

          dev->bid_name));

    goto open_err;

  }

  if (blkid_probe_set_device(cache->probe, fd, 0, 0)) {

    /* failed to read the device */

    close(fd);

    blkid_free_dev(dev);

    return NULL;

  }

  /* remove old cache info */

  iter = blkid_tag_iterate_begin(dev);

  while (blkid_tag_next(iter, &type, &value) == 0)

    blkid_set_tag(dev, type, NULL, 0);

  blkid_tag_iterate_end(iter);

  /* enable superblocks probing */

  blkid_probe_enable_superblocks(cache->probe, TRUE);

  blkid_probe_set_superblocks_flags(cache->probe,

    BLKID_SUBLKS_LABEL | BLKID_SUBLKS_UUID |

    BLKID_SUBLKS_TYPE | BLKID_SUBLKS_SECTYPE);

  /* enable partitions probing */

  blkid_probe_enable_partitions(cache->probe, TRUE);

  blkid_probe_set_partitions_flags(cache->probe, BLKID_PARTS_ENTRY_DETAILS);

  /* probe */

  if (blkid_do_safeprobe(cache->probe)) {

    /* found nothing or error */

    blkid_free_dev(dev);

    dev = NULL;

  }

  if (dev) {

#ifdef HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC

    struct timeval tv;

    if (!gettimeofday(&tv, NULL)) {

      dev->bid_time = tv.tv_sec;

      dev->bid_utime = tv.tv_usec;

    } else

#endif

      dev->bid_time = time(NULL);

    dev->bid_devno = st.st_rdev;

    dev->bid_flags |= BLKID_BID_FL_VERIFIED;

    cache->bic_flags |= BLKID_BIC_FL_CHANGED;

    blkid_probe_to_tags(cache->probe, dev);

    DBG(PROBE, ul_debug("%s: devno 0x%04llx, type %s",

         dev->bid_name, (long long)st.st_rdev, dev->bid_type));

  }

  /* reset prober */

  blkid_probe_reset_superblocks_filter(cache->probe);

  blkid_probe_set_device(cache->probe, -1, 0, 0);

  close(fd);

  return dev;

}

#ifdef TEST_PROGRAM

int main(int argc, char **argv)

{

  blkid_dev dev;

  blkid_cache cache;

  int ret;

  if (argc != 2) {

    fprintf(stderr, "Usage: %s device\n"

      "Probe a single device to determine type\n", argv[0]);

    exit(1);

  }

  if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {

    fprintf(stderr, "%s: error creating cache (%d)\n",

      argv[0], ret);

    exit(1);

  }

  dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);

  if (!dev) {

    printf("%s: %s has an unsupported type\n", argv[0], argv[1]);

    return (1);

  }

  printf("TYPE='%s'\n", dev->bid_type ? dev->bid_type : "(null)");

  if (dev->bid_label)

    printf("LABEL='%s'\n", dev->bid_label);

  if (dev->bid_uuid)

    printf("UUID='%s'\n", dev->bid_uuid);

  blkid_free_dev(dev);

  return (0);

}

#endif