contrib/wpa/src/ap/bss_load.c

   1 /*
   2  * BSS Load Element / Channel Utilization
   3  * Copyright (c) 2014, Qualcomm Atheros, Inc.
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "utils/includes.h"
  10
  11 #include "utils/common.h"
  12 #include "utils/eloop.h"
  13 #include "hostapd.h"
  14 #include "bss_load.h"
  15 #include "ap_drv_ops.h"
  16 #include "beacon.h"
  17
  18
  19 static int get_bss_load_update_timeout(struct hostapd_data *hapd,
  20                                        unsigned int *sec, unsigned int *usec)
  21 {
  22         unsigned int update_period = hapd->conf->bss_load_update_period;
  23         unsigned int beacon_int = hapd->iconf->beacon_int;
  24         unsigned int update_timeout;
  25
  26         if (!update_period || !beacon_int) {
  27                 wpa_printf(MSG_ERROR,
  28                            "BSS Load: Invalid BSS load update configuration (period=%u beacon_int=%u)",
  29                            update_period, beacon_int);
  30                 return -1;
  31         }
  32
  33         update_timeout = update_period * beacon_int;
  34
  35         *sec = ((update_timeout / 1000) * 1024) / 1000;
  36         *usec = (update_timeout % 1000) * 1024;
  37
  38         return 0;
  39 }
  40
  41
  42 static void update_channel_utilization(void *eloop_data, void *user_data)
  43 {
  44         struct hostapd_data *hapd = eloop_data;
  45         unsigned int sec, usec;
  46         int err;
  47         struct hostapd_iface *iface = hapd->iface;
  48
  49         if (!(hapd->beacon_set_done && hapd->started))
  50                 return;
  51
  52         err = hostapd_drv_get_survey(hapd, hapd->iface->freq);
  53         if (err) {
  54                 wpa_printf(MSG_ERROR, "BSS Load: Failed to get survey data");
  55                 return;
  56         }
  57
  58         ieee802_11_set_beacon(hapd);
  59
  60         if (get_bss_load_update_timeout(hapd, &sec, &usec) < 0)
  61                 return;
  62
  63         if (hapd->conf->chan_util_avg_period) {
  64                 iface->chan_util_samples_sum += iface->channel_utilization;
  65                 iface->chan_util_num_sample_periods +=
  66                         hapd->conf->bss_load_update_period;
  67                 if (iface->chan_util_num_sample_periods >=
  68                     hapd->conf->chan_util_avg_period) {
  69                         iface->chan_util_average =
  70                                 iface->chan_util_samples_sum /
  71                                 (iface->chan_util_num_sample_periods /
  72                                  hapd->conf->bss_load_update_period);
  73                         iface->chan_util_samples_sum = 0;
  74                         iface->chan_util_num_sample_periods = 0;
  75                 }
  76         }
  77
  78         eloop_register_timeout(sec, usec, update_channel_utilization, hapd,
  79                                NULL);
  80 }
  81
  82
  83 int bss_load_update_init(struct hostapd_data *hapd)
  84 {
  85         unsigned int sec, usec;
  86
  87         if (get_bss_load_update_timeout(hapd, &sec, &usec) < 0)
  88                 return -1;
  89
  90         eloop_register_timeout(sec, usec, update_channel_utilization, hapd,
  91                                NULL);
  92         return 0;
  93 }
  94
  95
  96 void bss_load_update_deinit(struct hostapd_data *hapd)
  97 {
  98         eloop_cancel_timeout(update_channel_utilization, hapd, NULL);
  99 }