band_steering.c

   1 /*
   2  *   This program is free software; you can redistribute it and/or modify
   3  *   it under the terms of the GNU General Public License as published by
   4  *   the Free Software Foundation; either version 2 of the License.
   5  *
   6  *   This program is distributed in the hope that it will be useful,
   7  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  *   GNU General Public License for more details.
  10  *
  11  *   You should have received a copy of the GNU General Public License
  12  *   along with this program; if not, write to the Free Software
  13  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
  14  *
  15  *   Copyright (C) 2022 David Bauer <mail@david-bauer.net>
  16  */
  17
  18 #include "usteer.h"
  19 #include "node.h"
  20
  21 void usteer_band_steering_sta_update(struct sta_info *si)
  22 {
  23         if (si->signal < usteer_snr_to_signal(si->node, config.band_steering_min_snr))
  24                 si->band_steering.below_snr = true;
  25 }
  26
  27 bool usteer_band_steering_is_target(struct usteer_local_node *ln, struct usteer_node *node)
  28 {
  29         if (&ln->node == node)
  30                 return false;
  31
  32         if (strcmp(ln->node.ssid, node->ssid))
  33                 return false;
  34
  35         if (node->freq < 4000)
  36                 return false;
  37
  38         if (!usteer_policy_node_below_max_assoc(node))
  39                 return false;
  40
  41         /* ToDo: Skip nodes with active load-kick */
  42
  43         return true;
  44  }
  45
  46
  47 static bool usteer_band_steering_has_target_iface(struct usteer_local_node *ln)
  48 {
  49         struct usteer_node *node;
  50
  51         for_each_local_node(node) {
  52                 if (usteer_band_steering_is_target(ln, node))
  53                         return true;
  54         }
  55
  56         return false;
  57 }
  58
  59 void usteer_band_steering_perform_steer(struct usteer_local_node *ln)
  60 {
  61         unsigned int min_count = DIV_ROUND_UP(config.band_steering_interval, config.local_sta_update);
  62         struct sta_info *si;
  63
  64         if (!config.band_steering_interval)
  65                 return;
  66
  67         /* Band-Steering is only available on 2.4 GHz interfaces */
  68         if (ln->node.freq > 4000)
  69                 return;
  70
  71         /* Check if we have an interface we can steer to */
  72         if (!usteer_band_steering_has_target_iface(ln))
  73                 return;
  74
  75         /* Only steer every interval */
  76         if (ln->band_steering_interval < min_count) {
  77                 ln->band_steering_interval++;
  78                 return;
  79         }
  80
  81         ln->band_steering_interval = 0;
  82
  83         list_for_each_entry(si, &ln->node.sta_info, node_list) {
  84                 /* Check if client is eligable to be steerd */
  85                 if (!usteer_policy_can_perform_roam(si))
  86                         continue;
  87
  88                 /* Skip clients with insufficient SNR-state */
  89                 if (si->band_steering.below_snr) {
  90                         si->band_steering.below_snr = false;
  91                         continue;
  92                 }
  93
  94                 if (si->bss_transition)
  95                         usteer_ubus_band_steering_request(si);
  96
  97                 si->band_steering.below_snr = false;
  98         }
  99 }