wpa_supplicant/mbo.c

   1 /*
   2  * wpa_supplicant - MBO
   3  *
   4  * Copyright(c) 2015 Intel Deutschland GmbH
   5  * Contact Information:
   6  * Intel Linux Wireless <ilw@linux.intel.com>
   7  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
   8  *
   9  * This software may be distributed under the terms of the BSD license.
  10  * See README for more details.
  11  */
  12
  13 #include "utils/includes.h"
  14
  15 #include "utils/common.h"
  16 #include "common/ieee802_11_defs.h"
  17 #include "config.h"
  18 #include "wpa_supplicant_i.h"
  19 #include "driver_i.h"
  20 #include "bss.h"
  21
  22 /* type + length + oui + oui type */
  23 #define MBO_IE_HEADER 6
  24
  25
  26 static int wpas_mbo_validate_non_pref_chan(u8 oper_class, u8 chan, u8 reason)
  27 {
  28         if (reason > MBO_NON_PREF_CHAN_REASON_INT_INTERFERENCE)
  29                 return -1;
  30
  31         /* Only checking the validity of the channel and oper_class */
  32         if (ieee80211_chan_to_freq(NULL, oper_class, chan) == -1)
  33                 return -1;
  34
  35         return 0;
  36 }
  37
  38
  39 static void wpas_mbo_non_pref_chan_attr_body(struct wpa_supplicant *wpa_s,
  40                                              struct wpabuf *mbo,
  41                                              u8 start, u8 end)
  42 {
  43         u8 i;
  44
  45         wpabuf_put_u8(mbo, wpa_s->non_pref_chan[start].oper_class);
  46
  47         for (i = start; i < end; i++)
  48                 wpabuf_put_u8(mbo, wpa_s->non_pref_chan[i].chan);
  49
  50         wpabuf_put_u8(mbo, wpa_s->non_pref_chan[start].preference);
  51         wpabuf_put_u8(mbo, wpa_s->non_pref_chan[start].reason);
  52         wpabuf_put_u8(mbo, wpa_s->non_pref_chan[start].reason_detail);
  53 }
  54
  55
  56 static void wpas_mbo_non_pref_chan_attr(struct wpa_supplicant *wpa_s,
  57                                         struct wpabuf *mbo, u8 start, u8 end)
  58 {
  59         size_t size = end - start + 4;
  60
  61         if (size + 2 > wpabuf_tailroom(mbo))
  62                 return;
  63
  64         wpabuf_put_u8(mbo, MBO_ATTR_ID_NON_PREF_CHAN_REPORT);
  65         wpabuf_put_u8(mbo, size); /* Length */
  66
  67         wpas_mbo_non_pref_chan_attr_body(wpa_s, mbo, start, end);
  68 }
  69
  70
  71 static void wpas_mbo_non_pref_chan_subelem_hdr(struct wpabuf *mbo, u8 len)
  72 {
  73         wpabuf_put_u8(mbo, WLAN_EID_VENDOR_SPECIFIC);
  74         wpabuf_put_u8(mbo, len); /* Length */
  75         wpabuf_put_be24(mbo, OUI_WFA);
  76         wpabuf_put_u8(mbo, MBO_ATTR_ID_NON_PREF_CHAN_REPORT);
  77 }
  78
  79
  80 static void wpas_mbo_non_pref_chan_subelement(struct wpa_supplicant *wpa_s,
  81                                               struct wpabuf *mbo, u8 start,
  82                                               u8 end)
  83 {
  84         size_t size = end - start + 8;
  85
  86         if (size + 2 > wpabuf_tailroom(mbo))
  87                 return;
  88
  89         wpas_mbo_non_pref_chan_subelem_hdr(mbo, size);
  90         wpas_mbo_non_pref_chan_attr_body(wpa_s, mbo, start, end);
  91 }
  92
  93
  94 static void wpas_mbo_non_pref_chan_attrs(struct wpa_supplicant *wpa_s,
  95                                          struct wpabuf *mbo, int subelement)
  96 {
  97         u8 i, start = 0;
  98         struct wpa_mbo_non_pref_channel *start_pref;
  99
 100         if (!wpa_s->non_pref_chan || !wpa_s->non_pref_chan_num) {
 101                 if (subelement)
 102                         wpas_mbo_non_pref_chan_subelem_hdr(mbo, 4);
 103                 return;
 104         }
 105         start_pref = &wpa_s->non_pref_chan[0];
 106
 107         for (i = 1; i <= wpa_s->non_pref_chan_num; i++) {
 108                 struct wpa_mbo_non_pref_channel *non_pref = NULL;
 109
 110                 if (i < wpa_s->non_pref_chan_num)
 111                         non_pref = &wpa_s->non_pref_chan[i];
 112                 if (!non_pref ||
 113                     non_pref->oper_class != start_pref->oper_class ||
 114                     non_pref->reason != start_pref->reason ||
 115                     non_pref->reason_detail != start_pref->reason_detail ||
 116                     non_pref->preference != start_pref->preference) {
 117                         if (subelement)
 118                                 wpas_mbo_non_pref_chan_subelement(wpa_s, mbo,
 119                                                                   start, i);
 120                         else
 121                                 wpas_mbo_non_pref_chan_attr(wpa_s, mbo, start,
 122                                                             i);
 123
 124                         if (!non_pref)
 125                                 return;
 126
 127                         start = i;
 128                         start_pref = non_pref;
 129                 }
 130         }
 131 }
 132
 133
 134 int wpas_mbo_ie(struct wpa_supplicant *wpa_s, u8 *buf, size_t len)
 135 {
 136         struct wpabuf *mbo;
 137         int res;
 138
 139         if (!wpa_s->non_pref_chan || !wpa_s->non_pref_chan_num ||
 140             len < MBO_IE_HEADER + 7)
 141                 return 0;
 142
 143         /* Leave room for the MBO IE header */
 144         mbo = wpabuf_alloc(len - MBO_IE_HEADER);
 145         if (!mbo)
 146                 return 0;
 147
 148         /* Add non-preferred channels attribute */
 149         wpas_mbo_non_pref_chan_attrs(wpa_s, mbo, 0);
 150
 151         res = mbo_add_ie(buf, len, wpabuf_head_u8(mbo), wpabuf_len(mbo));
 152         if (!res)
 153                 wpa_printf(MSG_ERROR, "Failed to add MBO IE");
 154
 155         wpabuf_free(mbo);
 156         return res;
 157 }
 158
 159
 160 static void wpas_mbo_send_wnm_notification(struct wpa_supplicant *wpa_s)
 161 {
 162         struct wpabuf *buf;
 163         int res;
 164
 165         /*
 166          * Send WNM-Notification Request frame only in case of a change in
 167          * non-preferred channels list during association, if the AP supports
 168          * MBO.
 169          */
 170         if (wpa_s->wpa_state != WPA_COMPLETED || !wpa_s->current_bss ||
 171             !wpa_bss_get_vendor_ie(wpa_s->current_bss, MBO_IE_VENDOR_TYPE))
 172                 return;
 173
 174         buf = wpabuf_alloc(512);
 175         if (!buf)
 176                 return;
 177
 178         wpabuf_put_u8(buf, WLAN_ACTION_WNM);
 179         wpabuf_put_u8(buf, WNM_NOTIFICATION_REQ);
 180         wpa_s->mbo_wnm_token++;
 181         if (wpa_s->mbo_wnm_token == 0)
 182                 wpa_s->mbo_wnm_token++;
 183         wpabuf_put_u8(buf, wpa_s->mbo_wnm_token);
 184         wpabuf_put_u8(buf, WLAN_EID_VENDOR_SPECIFIC); /* Type */
 185
 186         wpas_mbo_non_pref_chan_attrs(wpa_s, buf, 1);
 187
 188         res = wpa_drv_send_action(wpa_s, wpa_s->assoc_freq, 0, wpa_s->bssid,
 189                                   wpa_s->own_addr, wpa_s->bssid,
 190                                   wpabuf_head(buf), wpabuf_len(buf), 0);
 191         if (res < 0)
 192                 wpa_printf(MSG_DEBUG,
 193                            "Failed to send WNM-Notification Request frame with non-preferred channel list");
 194
 195         wpabuf_free(buf);
 196 }
 197
 198
 199 static int wpa_non_pref_chan_is_eq(struct wpa_mbo_non_pref_channel *a,
 200                                    struct wpa_mbo_non_pref_channel *b)
 201 {
 202         return a->oper_class == b->oper_class && a->chan == b->chan;
 203 }
 204
 205
 206 /*
 207  * wpa_non_pref_chan_cmp - Compare two channels for sorting
 208  *
 209  * In MBO IE non-preferred channel subelement we can put many channels in an
 210  * attribute if they are in the same operating class and have the same
 211  * preference, reason, and reason detail. To make it easy for the functions that
 212  * build the IE attributes and WNM Request subelements, save the channels sorted
 213  * by their oper_class, reason, and reason_detail.
 214  */
 215 static int wpa_non_pref_chan_cmp(const void *_a, const void *_b)
 216 {
 217         const struct wpa_mbo_non_pref_channel *a = _a, *b = _b;
 218
 219         if (a->oper_class != b->oper_class)
 220                 return a->oper_class - b->oper_class;
 221         if (a->reason != b->reason)
 222                 return a->reason - b->reason;
 223         if (a->reason_detail != b->reason_detail)
 224                 return a->reason_detail - b->reason_detail;
 225         return a->preference - b->preference;
 226 }
 227
 228
 229 int wpas_mbo_update_non_pref_chan(struct wpa_supplicant *wpa_s,
 230                                   const char *non_pref_chan)
 231 {
 232         char *cmd, *token, *context = NULL;
 233         struct wpa_mbo_non_pref_channel *chans = NULL, *tmp_chans;
 234         size_t num = 0, size = 0;
 235         unsigned i;
 236
 237         wpa_printf(MSG_DEBUG, "MBO: Update non-preferred channels, non_pref_chan=%s",
 238                    non_pref_chan ? non_pref_chan : "N/A");
 239
 240         /*
 241          * The shortest channel configuration is 10 characters - commas, 3
 242          * colons, and 4 values that one of them (oper_class) is 2 digits or
 243          * more.
 244          */
 245         if (!non_pref_chan || os_strlen(non_pref_chan) < 10)
 246                 goto update;
 247
 248         cmd = os_strdup(non_pref_chan);
 249         if (!cmd)
 250                 return -1;
 251
 252         while ((token = str_token(cmd, " ", &context))) {
 253                 struct wpa_mbo_non_pref_channel *chan;
 254                 int ret;
 255                 unsigned int _oper_class;
 256                 unsigned int _chan;
 257                 unsigned int _preference;
 258                 unsigned int _reason;
 259                 unsigned int _reason_detail;
 260
 261                 if (num == size) {
 262                         size = size ? size * 2 : 1;
 263                         tmp_chans = os_realloc_array(chans, size,
 264                                                      sizeof(*chans));
 265                         if (!tmp_chans) {
 266                                 wpa_printf(MSG_ERROR,
 267                                            "Couldn't reallocate non_pref_chan");
 268                                 goto fail;
 269                         }
 270                         chans = tmp_chans;
 271                 }
 272
 273                 chan = &chans[num];
 274
 275                 ret = sscanf(token, "%u:%u:%u:%u:%u", &_oper_class,
 276                              &_chan, &_preference, &_reason,
 277                              &_reason_detail);
 278                 if ((ret != 4 && ret != 5) ||
 279                     _oper_class > 255 || _chan > 255 ||
 280                     _preference > 255 || _reason > 65535 ||
 281                     (ret == 5 && _reason_detail > 255)) {
 282                         wpa_printf(MSG_ERROR, "Invalid non-pref chan input %s",
 283                                    token);
 284                         goto fail;
 285                 }
 286                 chan->oper_class = _oper_class;
 287                 chan->chan = _chan;
 288                 chan->preference = _preference;
 289                 chan->reason = _reason;
 290                 chan->reason_detail = ret == 4 ? 0 : _reason_detail;
 291
 292                 if (wpas_mbo_validate_non_pref_chan(chan->oper_class,
 293                                                     chan->chan, chan->reason)) {
 294                         wpa_printf(MSG_ERROR,
 295                                    "Invalid non_pref_chan: oper class %d chan %d reason %d",
 296                                    chan->oper_class, chan->chan, chan->reason);
 297                         goto fail;
 298                 }
 299
 300                 for (i = 0; i < num; i++)
 301                         if (wpa_non_pref_chan_is_eq(chan, &chans[i]))
 302                                 break;
 303                 if (i != num) {
 304                         wpa_printf(MSG_ERROR,
 305                                    "oper class %d chan %d is duplicated",
 306                                    chan->oper_class, chan->chan);
 307                         goto fail;
 308                 }
 309
 310                 num++;
 311         }
 312
 313         os_free(cmd);
 314
 315         if (chans) {
 316                 qsort(chans, num, sizeof(struct wpa_mbo_non_pref_channel),
 317                       wpa_non_pref_chan_cmp);
 318         }
 319
 320 update:
 321         os_free(wpa_s->non_pref_chan);
 322         wpa_s->non_pref_chan = chans;
 323         wpa_s->non_pref_chan_num = num;
 324         wpas_mbo_send_wnm_notification(wpa_s);
 325
 326         return 0;
 327
 328 fail:
 329         os_free(chans);
 330         os_free(cmd);
 331         return -1;
 332 }