/*

 * wpa_supplicant - List of temporarily ignored BSSIDs

 * Copyright (c) 2003-2021, Jouni Malinen <j@w1.fi>

 *

 * This software may be distributed under the terms of the BSD license.

 * See README for more details.

 */

#include "includes.h"

#include "common.h"

#include "wpa_supplicant_i.h"

#include "bssid_ignore.h"

/**

 * wpa_bssid_ignore_get - Get the ignore list entry for a BSSID

 * @wpa_s: Pointer to wpa_supplicant data

 * @bssid: BSSID

 * Returns: Matching entry for the BSSID or %NULL if not found

 */

struct wpa_bssid_ignore * wpa_bssid_ignore_get(struct wpa_supplicant *wpa_s,

                 const u8 *bssid)

{

  struct wpa_bssid_ignore *e;

  if (wpa_s == NULL || bssid == NULL)

    return NULL;

  if (wpa_s->current_ssid &&

      wpa_s->current_ssid->was_recently_reconfigured) {

    wpa_bssid_ignore_clear(wpa_s);

    wpa_s->current_ssid->was_recently_reconfigured = false;

    return NULL;

  }

  wpa_bssid_ignore_update(wpa_s);

  e = wpa_s->bssid_ignore;

  while (e) {

    if (ether_addr_equal(e->bssid, bssid))

      return e;

    e = e->next;

  }

  return NULL;

}

/**

 * wpa_bssid_ignore_add - Add an BSSID to the ignore list

 * @wpa_s: Pointer to wpa_supplicant data

 * @bssid: BSSID to be added to the ignore list

 * Returns: Current ignore list count on success, -1 on failure

 *

 * This function adds the specified BSSID to the ignore list or increases the

 * ignore count if the BSSID was already listed. It should be called when

 * an association attempt fails either due to the selected BSS rejecting

 * association or due to timeout.

 *

 * This ignore list is used to force %wpa_supplicant to go through all available

 * BSSes before retrying to associate with an BSS that rejected or timed out

 * association. It does not prevent the listed BSS from being used; it only

 * changes the order in which they are tried.

 */

int wpa_bssid_ignore_add(struct wpa_supplicant *wpa_s, const u8 *bssid)

{

  struct wpa_bssid_ignore *e;

  struct os_reltime now;

  if (wpa_s == NULL || bssid == NULL)

    return -1;

  e = wpa_bssid_ignore_get(wpa_s, bssid);

  os_get_reltime(&now);

  if (e) {

    e->start = now;

    e->count++;

    if (e->count > 5)

      e->timeout_secs = 1800;

    else if (e->count == 5)

      e->timeout_secs = 600;

    else if (e->count == 4)

      e->timeout_secs = 120;

    else if (e->count == 3)

      e->timeout_secs = 60;

    else

      e->timeout_secs = 10;

    wpa_msg(wpa_s, MSG_INFO, "BSSID " MACSTR

      " ignore list count incremented to %d, ignoring for %d seconds",

      MAC2STR(bssid), e->count, e->timeout_secs);

    return e->count;

  }

  e = os_zalloc(sizeof(*e));

  if (e == NULL)

    return -1;

  os_memcpy(e->bssid, bssid, ETH_ALEN);

  e->count = 1;

  e->timeout_secs = 10;

  e->start = now;

  e->next = wpa_s->bssid_ignore;

  wpa_s->bssid_ignore = e;

  wpa_msg(wpa_s, MSG_INFO, "Added BSSID " MACSTR

    " into ignore list, ignoring for %d seconds",

    MAC2STR(bssid), e->timeout_secs);

  return e->count;

}

/**

 * wpa_bssid_ignore_del - Remove an BSSID from the ignore list

 * @wpa_s: Pointer to wpa_supplicant data

 * @bssid: BSSID to be removed from the ignore list

 * Returns: 0 on success, -1 on failure

 */

int wpa_bssid_ignore_del(struct wpa_supplicant *wpa_s, const u8 *bssid)

{

  struct wpa_bssid_ignore *e, *prev = NULL;

  if (wpa_s == NULL || bssid == NULL)

    return -1;

  e = wpa_s->bssid_ignore;

  while (e) {

    if (ether_addr_equal(e->bssid, bssid)) {

      if (prev == NULL) {

        wpa_s->bssid_ignore = e->next;

      } else {

        prev->next = e->next;

      }

      wpa_msg(wpa_s, MSG_INFO, "Removed BSSID " MACSTR

        " from ignore list", MAC2STR(bssid));

      os_free(e);

      return 0;

    }

    prev = e;

    e = e->next;

  }

  return -1;

}

/**

 * wpa_bssid_ignore_is_listed - Check whether a BSSID is ignored temporarily

 * @wpa_s: Pointer to wpa_supplicant data

 * @bssid: BSSID to be checked

 * Returns: count if BSS is currently considered to be ignored, 0 otherwise

 */

int wpa_bssid_ignore_is_listed(struct wpa_supplicant *wpa_s, const u8 *bssid)

{

  struct wpa_bssid_ignore *e;

  struct os_reltime now;

  e = wpa_bssid_ignore_get(wpa_s, bssid);

  if (!e)

    return 0;

  os_get_reltime(&now);

  if (os_reltime_expired(&now, &e->start, e->timeout_secs))

    return 0;

  return e->count;

}

/**

 * wpa_bssid_ignore_clear - Clear the ignore list of all entries

 * @wpa_s: Pointer to wpa_supplicant data

 */

void wpa_bssid_ignore_clear(struct wpa_supplicant *wpa_s)

{

  struct wpa_bssid_ignore *e, *prev;

  e = wpa_s->bssid_ignore;

  wpa_s->bssid_ignore = NULL;

  while (e) {

    prev = e;

    e = e->next;

    wpa_msg(wpa_s, MSG_INFO, "Removed BSSID " MACSTR

      " from ignore list (clear)", MAC2STR(prev->bssid));

    os_free(prev);

  }

}

/**

 * wpa_bssid_ignore_update - Update the entries in the ignore list,

 * deleting entries that have been expired for over an hour.

 * @wpa_s: Pointer to wpa_supplicant data

 */

void wpa_bssid_ignore_update(struct wpa_supplicant *wpa_s)

{

  struct wpa_bssid_ignore *e, *prev = NULL;

  struct os_reltime now;

  if (!wpa_s)

    return;

  e = wpa_s->bssid_ignore;

  os_get_reltime(&now);

  while (e) {

    if (os_reltime_expired(&now, &e->start,

               e->timeout_secs + 3600)) {

      struct wpa_bssid_ignore *to_delete = e;

      if (prev) {

        prev->next = e->next;

        e = prev->next;

      } else {

        wpa_s->bssid_ignore = e->next;

        e = wpa_s->bssid_ignore;

      }

      wpa_msg(wpa_s, MSG_INFO, "Removed BSSID " MACSTR

        " from ignore list (expired)",

        MAC2STR(to_delete->bssid));

      os_free(to_delete);

    } else {

      prev = e;

      e = e->next;

    }

  }

}