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Commit 6790325e authored by Marie Janssen's avatar Marie Janssen Committed by android-build-merger
Browse files

Fix crashes with lots of discovered LE devices 

am: 24777604

* commit '24777604':
  Fix crashes with lots of discovered LE devices
parents e078a622 24777604

system/btif/src/btif_config.c

+44 −36
Original line number Diff line number Diff line
@@ -42,7 +42,9 @@ static const char *CONFIG_FILE_PATH = "/data/misc/bluedroid/bt_config.conf"; 
static const char *LEGACY_CONFIG_FILE_PATH = "/data/misc/bluedroid/bt_config.xml";

static const period_ms_t CONFIG_SETTLE_PERIOD_MS = 3000;



static void timer_config_save(void *data);

static void timer_config_save_cb(void *data);

static void btif_config_write(void);

static void btif_config_devcache_cleanup(void);



// TODO(zachoverflow): Move these two functions out, because they are too specific for this file

// {grumpy-cat/no, monty-python/you-make-me-sad}
@@ -107,6 +109,8 @@ static future_t *init(void) { 
      unlink(LEGACY_CONFIG_FILE_PATH);

  }



  btif_config_devcache_cleanup();



  // TODO(sharvil): use a non-wake alarm for this once we have

  // API support for it. There's no need to wake the system to

  // write back to disk.
@@ -346,7 +350,7 @@ void btif_config_save(void) { 
  assert(alarm_timer != NULL);

  assert(config != NULL);



  alarm_set(alarm_timer, CONFIG_SETTLE_PERIOD_MS, timer_config_save, NULL);

  alarm_set(alarm_timer, CONFIG_SETTLE_PERIOD_MS, timer_config_save_cb, NULL);

}



void btif_config_flush(void) {
@@ -355,9 +359,7 @@ void btif_config_flush(void) { 


  alarm_cancel(alarm_timer);



  pthread_mutex_lock(&lock);

  config_save(config, CONFIG_FILE_PATH);

  pthread_mutex_unlock(&lock);

  btif_config_write();

}



int btif_config_clear(void){
@@ -380,45 +382,51 @@ int btif_config_clear(void){ 
  return ret;

}



static void timer_config_save(UNUSED_ATTR void *data) {

static void timer_config_save_cb(UNUSED_ATTR void *data) {

  btif_config_write();

}



static void btif_config_write(void) {

  assert(config != NULL);

  assert(alarm_timer != NULL);



  // Garbage collection process: the config file accumulates

  // cached information about remote devices during regular

  // inquiry scans. We remove some of these junk entries

  // so the file doesn't grow indefinitely. We have to take care

  // to make sure we don't remove information about bonded

  // devices (hence the check for link keys).

  static const size_t CACHE_MAX = 256;

  const char *keys[CACHE_MAX];

  size_t num_keys = 0;

  size_t total_candidates = 0;

  btif_config_devcache_cleanup();



  pthread_mutex_lock(&lock);

  for (const config_section_node_t *snode = config_section_begin(config); snode != config_section_end(config); snode = config_section_next(snode)) {

    const char *section = config_section_name(snode);

    if (!string_is_bdaddr(section))

      continue;

  config_save(config, CONFIG_FILE_PATH);

  pthread_mutex_unlock(&lock);

}



    if (config_has_key(config, section, "LinkKey") ||

        config_has_key(config, section, "LE_KEY_PENC") ||

        config_has_key(config, section, "LE_KEY_PID") ||

        config_has_key(config, section, "LE_KEY_PCSRK") ||

        config_has_key(config, section, "LE_KEY_LENC") ||

        config_has_key(config, section, "LE_KEY_LCSRK"))

      continue;

static void btif_config_devcache_cleanup(void) {

  assert(config != NULL);



    if (num_keys < CACHE_MAX)

      keys[num_keys++] = section;

  // The config accumulates cached information about remote

  // devices during regular inquiry scans. We remove some of these

  // so the cache doesn't grow indefinitely.

  // We don't remove information about bonded devices (which have link keys).

  static const size_t ADDRS_MAX = 512;

  size_t total_addrs = 0;



    ++total_candidates;

  pthread_mutex_lock(&lock);

  const config_section_node_t *snode = config_section_begin(config);

  while (snode != config_section_end(config)) {

    const char *section = config_section_name(snode);

    if (string_is_bdaddr(section)) {

      ++total_addrs;



      if ((total_addrs > ADDRS_MAX) &&

          !config_has_key(config, section, "LinkKey") &&

          !config_has_key(config, section, "LE_KEY_PENC") &&

          !config_has_key(config, section, "LE_KEY_PID") &&

          !config_has_key(config, section, "LE_KEY_PCSRK") &&

          !config_has_key(config, section, "LE_KEY_LENC") &&

          !config_has_key(config, section, "LE_KEY_LCSRK")) {

        snode = config_section_next(snode);

        config_remove_section(config, section);

        continue;

      }

    }

    snode = config_section_next(snode);

  }



  if (total_candidates > CACHE_MAX * 2)

    while (num_keys > 0)

      config_remove_section(config, keys[--num_keys]);



  config_save(config, CONFIG_FILE_PATH);

  pthread_mutex_unlock(&lock);

}