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 (len < MBO_IE_HEADER + 3 + 7)
 140                 return 0;
 141
 142         /* Leave room for the MBO IE header */
 143         mbo = wpabuf_alloc(len - MBO_IE_HEADER);
 144         if (!mbo)
 145                 return 0;
 146
 147         /* Add non-preferred channels attribute */
 148         wpas_mbo_non_pref_chan_attrs(wpa_s, mbo, 0);
 149
 150         /*
 151          * Send cellular capabilities attribute even if AP does not advertise
 152          * cellular capabilities.
 153          */
 154         wpabuf_put_u8(mbo, MBO_ATTR_ID_CELL_DATA_CAPA);
 155         wpabuf_put_u8(mbo, 1);
 156         wpabuf_put_u8(mbo, wpa_s->conf->mbo_cell_capa);
 157
 158         res = mbo_add_ie(buf, len, wpabuf_head_u8(mbo), wpabuf_len(mbo));
 159         if (!res)
 160                 wpa_printf(MSG_ERROR, "Failed to add MBO IE");
 161
 162         wpabuf_free(mbo);
 163         return res;
 164 }
 165
 166
 167 static void wpas_mbo_send_wnm_notification(struct wpa_supplicant *wpa_s)
 168 {
 169         struct wpabuf *buf;
 170         int res;
 171
 172         /*
 173          * Send WNM-Notification Request frame only in case of a change in
 174          * non-preferred channels list during association, if the AP supports
 175          * MBO.
 176          */
 177         if (wpa_s->wpa_state != WPA_COMPLETED || !wpa_s->current_bss ||
 178             !wpa_bss_get_vendor_ie(wpa_s->current_bss, MBO_IE_VENDOR_TYPE))
 179                 return;
 180
 181         buf = wpabuf_alloc(512);
 182         if (!buf)
 183                 return;
 184
 185         wpabuf_put_u8(buf, WLAN_ACTION_WNM);
 186         wpabuf_put_u8(buf, WNM_NOTIFICATION_REQ);
 187         wpa_s->mbo_wnm_token++;
 188         if (wpa_s->mbo_wnm_token == 0)
 189                 wpa_s->mbo_wnm_token++;
 190         wpabuf_put_u8(buf, wpa_s->mbo_wnm_token);
 191         wpabuf_put_u8(buf, WLAN_EID_VENDOR_SPECIFIC); /* Type */
 192
 193         wpas_mbo_non_pref_chan_attrs(wpa_s, buf, 1);
 194
 195         res = wpa_drv_send_action(wpa_s, wpa_s->assoc_freq, 0, wpa_s->bssid,
 196                                   wpa_s->own_addr, wpa_s->bssid,
 197                                   wpabuf_head(buf), wpabuf_len(buf), 0);
 198         if (res < 0)
 199                 wpa_printf(MSG_DEBUG,
 200                            "Failed to send WNM-Notification Request frame with non-preferred channel list");
 201
 202         wpabuf_free(buf);
 203 }
 204
 205
 206 static int wpa_non_pref_chan_is_eq(struct wpa_mbo_non_pref_channel *a,
 207                                    struct wpa_mbo_non_pref_channel *b)
 208 {
 209         return a->oper_class == b->oper_class && a->chan == b->chan;
 210 }
 211
 212
 213 /*
 214  * wpa_non_pref_chan_cmp - Compare two channels for sorting
 215  *
 216  * In MBO IE non-preferred channel subelement we can put many channels in an
 217  * attribute if they are in the same operating class and have the same
 218  * preference, reason, and reason detail. To make it easy for the functions that
 219  * build the IE attributes and WNM Request subelements, save the channels sorted
 220  * by their oper_class, reason, and reason_detail.
 221  */
 222 static int wpa_non_pref_chan_cmp(const void *_a, const void *_b)
 223 {
 224         const struct wpa_mbo_non_pref_channel *a = _a, *b = _b;
 225
 226         if (a->oper_class != b->oper_class)
 227                 return a->oper_class - b->oper_class;
 228         if (a->reason != b->reason)
 229                 return a->reason - b->reason;
 230         if (a->reason_detail != b->reason_detail)
 231                 return a->reason_detail - b->reason_detail;
 232         return a->preference - b->preference;
 233 }
 234
 235
 236 int wpas_mbo_update_non_pref_chan(struct wpa_supplicant *wpa_s,
 237                                   const char *non_pref_chan)
 238 {
 239         char *cmd, *token, *context = NULL;
 240         struct wpa_mbo_non_pref_channel *chans = NULL, *tmp_chans;
 241         size_t num = 0, size = 0;
 242         unsigned i;
 243
 244         wpa_printf(MSG_DEBUG, "MBO: Update non-preferred channels, non_pref_chan=%s",
 245                    non_pref_chan ? non_pref_chan : "N/A");
 246
 247         /*
 248          * The shortest channel configuration is 10 characters - commas, 3
 249          * colons, and 4 values that one of them (oper_class) is 2 digits or
 250          * more.
 251          */
 252         if (!non_pref_chan || os_strlen(non_pref_chan) < 10)
 253                 goto update;
 254
 255         cmd = os_strdup(non_pref_chan);
 256         if (!cmd)
 257                 return -1;
 258
 259         while ((token = str_token(cmd, " ", &context))) {
 260                 struct wpa_mbo_non_pref_channel *chan;
 261                 int ret;
 262                 unsigned int _oper_class;
 263                 unsigned int _chan;
 264                 unsigned int _preference;
 265                 unsigned int _reason;
 266                 unsigned int _reason_detail;
 267
 268                 if (num == size) {
 269                         size = size ? size * 2 : 1;
 270                         tmp_chans = os_realloc_array(chans, size,
 271                                                      sizeof(*chans));
 272                         if (!tmp_chans) {
 273                                 wpa_printf(MSG_ERROR,
 274                                            "Couldn't reallocate non_pref_chan");
 275                                 goto fail;
 276                         }
 277                         chans = tmp_chans;
 278                 }
 279
 280                 chan = &chans[num];
 281
 282                 ret = sscanf(token, "%u:%u:%u:%u:%u", &_oper_class,
 283                              &_chan, &_preference, &_reason,
 284                              &_reason_detail);
 285                 if ((ret != 4 && ret != 5) ||
 286                     _oper_class > 255 || _chan > 255 ||
 287                     _preference > 255 || _reason > 65535 ||
 288                     (ret == 5 && _reason_detail > 255)) {
 289                         wpa_printf(MSG_ERROR, "Invalid non-pref chan input %s",
 290                                    token);
 291                         goto fail;
 292                 }
 293                 chan->oper_class = _oper_class;
 294                 chan->chan = _chan;
 295                 chan->preference = _preference;
 296                 chan->reason = _reason;
 297                 chan->reason_detail = ret == 4 ? 0 : _reason_detail;
 298
 299                 if (wpas_mbo_validate_non_pref_chan(chan->oper_class,
 300                                                     chan->chan, chan->reason)) {
 301                         wpa_printf(MSG_ERROR,
 302                                    "Invalid non_pref_chan: oper class %d chan %d reason %d",
 303                                    chan->oper_class, chan->chan, chan->reason);
 304                         goto fail;
 305                 }
 306
 307                 for (i = 0; i < num; i++)
 308                         if (wpa_non_pref_chan_is_eq(chan, &chans[i]))
 309                                 break;
 310                 if (i != num) {
 311                         wpa_printf(MSG_ERROR,
 312                                    "oper class %d chan %d is duplicated",
 313                                    chan->oper_class, chan->chan);
 314                         goto fail;
 315                 }
 316
 317                 num++;
 318         }
 319
 320         os_free(cmd);
 321
 322         if (chans) {
 323                 qsort(chans, num, sizeof(struct wpa_mbo_non_pref_channel),
 324                       wpa_non_pref_chan_cmp);
 325         }
 326
 327 update:
 328         os_free(wpa_s->non_pref_chan);
 329         wpa_s->non_pref_chan = chans;
 330         wpa_s->non_pref_chan_num = num;
 331         wpas_mbo_send_wnm_notification(wpa_s);
 332
 333         return 0;
 334
 335 fail:
 336         os_free(chans);
 337         os_free(cmd);
 338         return -1;
 339 }
 340
 341
 342 void wpas_mbo_scan_ie(struct wpa_supplicant *wpa_s, struct wpabuf *ie)
 343 {
 344         wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
 345         wpabuf_put_u8(ie, 7);
 346         wpabuf_put_be24(ie, OUI_WFA);
 347         wpabuf_put_u8(ie, MBO_OUI_TYPE);
 348
 349         wpabuf_put_u8(ie, MBO_ATTR_ID_CELL_DATA_CAPA);
 350         wpabuf_put_u8(ie, 1);
 351         wpabuf_put_u8(ie, wpa_s->conf->mbo_cell_capa);
 352 }