wpa_supplicant/offchannel.c

   1 /*
   2  * wpa_supplicant - Off-channel Action frame TX/RX
   3  * Copyright (c) 2009-2010, Atheros Communications
   4  * Copyright (c) 2011, Qualcomm Atheros
   5  *
   6  * This software may be distributed under the terms of the BSD license.
   7  * See README for more details.
   8  */
   9
  10 #include "includes.h"
  11
  12 #include "common.h"
  13 #include "utils/eloop.h"
  14 #include "wpa_supplicant_i.h"
  15 #include "driver_i.h"
  16 #include "offchannel.h"
  17
  18
  19
  20 static struct wpa_supplicant *
  21 wpas_get_tx_interface(struct wpa_supplicant *wpa_s, const u8 *src)
  22 {
  23         struct wpa_supplicant *iface;
  24
  25         if (os_memcmp(src, wpa_s->own_addr, ETH_ALEN) == 0)
  26                 return wpa_s;
  27
  28         /*
  29          * Try to find a group interface that matches with the source address.
  30          */
  31         iface = wpa_s->global->ifaces;
  32         while (iface) {
  33                 if (os_memcmp(wpa_s->pending_action_src,
  34                               iface->own_addr, ETH_ALEN) == 0)
  35                         break;
  36                 iface = iface->next;
  37         }
  38         if (iface) {
  39                 wpa_printf(MSG_DEBUG, "P2P: Use group interface %s "
  40                            "instead of interface %s for Action TX",
  41                            iface->ifname, wpa_s->ifname);
  42                 return iface;
  43         }
  44
  45         return wpa_s;
  46 }
  47
  48
  49 static void wpas_send_action_cb(void *eloop_ctx, void *timeout_ctx)
  50 {
  51         struct wpa_supplicant *wpa_s = eloop_ctx;
  52         struct wpa_supplicant *iface;
  53         int res;
  54         int without_roc;
  55
  56         without_roc = wpa_s->pending_action_without_roc;
  57         wpa_s->pending_action_without_roc = 0;
  58         wpa_printf(MSG_DEBUG,
  59                    "Off-channel: Send Action callback (without_roc=%d pending_action_tx=%p pending_action_tx_done=%d)",
  60                    without_roc, wpa_s->pending_action_tx,
  61                    !!wpa_s->pending_action_tx_done);
  62
  63         if (wpa_s->pending_action_tx == NULL || wpa_s->pending_action_tx_done)
  64                 return;
  65
  66         /*
  67          * This call is likely going to be on the P2P device instance if the
  68          * driver uses a separate interface for that purpose. However, some
  69          * Action frames are actually sent within a P2P Group and when that is
  70          * the case, we need to follow power saving (e.g., GO buffering the
  71          * frame for a client in PS mode or a client following the advertised
  72          * NoA from its GO). To make that easier for the driver, select the
  73          * correct group interface here.
  74          */
  75         iface = wpas_get_tx_interface(wpa_s, wpa_s->pending_action_src);
  76
  77         if (wpa_s->off_channel_freq != wpa_s->pending_action_freq &&
  78             wpa_s->pending_action_freq != 0 &&
  79             wpa_s->pending_action_freq != iface->assoc_freq) {
  80                 wpa_printf(MSG_DEBUG, "Off-channel: Pending Action frame TX "
  81                            "waiting for another freq=%u (off_channel_freq=%u "
  82                            "assoc_freq=%u)",
  83                            wpa_s->pending_action_freq,
  84                            wpa_s->off_channel_freq,
  85                            iface->assoc_freq);
  86                 if (without_roc && wpa_s->off_channel_freq == 0) {
  87                         unsigned int duration = 200;
  88                         /*
  89                          * We may get here if wpas_send_action() found us to be
  90                          * on the correct channel, but remain-on-channel cancel
  91                          * event was received before getting here.
  92                          */
  93                         wpa_printf(MSG_DEBUG, "Off-channel: Schedule "
  94                                    "remain-on-channel to send Action frame");
  95 #ifdef CONFIG_TESTING_OPTIONS
  96                         if (wpa_s->extra_roc_dur) {
  97                                 wpa_printf(MSG_DEBUG,
  98                                            "TESTING: Increase ROC duration %u -> %u",
  99                                            duration,
 100                                            duration + wpa_s->extra_roc_dur);
 101                                 duration += wpa_s->extra_roc_dur;
 102         }
 103 #endif /* CONFIG_TESTING_OPTIONS */
 104                         if (wpa_drv_remain_on_channel(
 105                                     wpa_s, wpa_s->pending_action_freq,
 106                                     duration) < 0) {
 107                                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to "
 108                                            "request driver to remain on "
 109                                            "channel (%u MHz) for Action Frame "
 110                                            "TX", wpa_s->pending_action_freq);
 111                         } else {
 112                                 wpa_s->off_channel_freq = 0;
 113                                 wpa_s->roc_waiting_drv_freq =
 114                                         wpa_s->pending_action_freq;
 115                         }
 116                 }
 117                 return;
 118         }
 119
 120         wpa_printf(MSG_DEBUG, "Off-channel: Sending pending Action frame to "
 121                    MACSTR " using interface %s",
 122                    MAC2STR(wpa_s->pending_action_dst), iface->ifname);
 123         res = wpa_drv_send_action(iface, wpa_s->pending_action_freq, 0,
 124                                   wpa_s->pending_action_dst,
 125                                   wpa_s->pending_action_src,
 126                                   wpa_s->pending_action_bssid,
 127                                   wpabuf_head(wpa_s->pending_action_tx),
 128                                   wpabuf_len(wpa_s->pending_action_tx),
 129                                   wpa_s->pending_action_no_cck);
 130         if (res) {
 131                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to send the "
 132                            "pending Action frame");
 133                 /*
 134                  * Use fake TX status event to allow state machines to
 135                  * continue.
 136                  */
 137                 offchannel_send_action_tx_status(
 138                         wpa_s, wpa_s->pending_action_dst,
 139                         wpabuf_head(wpa_s->pending_action_tx),
 140                         wpabuf_len(wpa_s->pending_action_tx),
 141                         OFFCHANNEL_SEND_ACTION_FAILED);
 142         }
 143 }
 144
 145
 146 /**
 147  * offchannel_send_action_tx_status - TX status callback
 148  * @wpa_s: Pointer to wpa_supplicant data
 149  * @dst: Destination MAC address of the transmitted Action frame
 150  * @data: Transmitted frame payload
 151  * @data_len: Length of @data in bytes
 152  * @result: TX status
 153  *
 154  * This function is called whenever the driver indicates a TX status event for
 155  * a frame sent by offchannel_send_action() using wpa_drv_send_action().
 156  */
 157 void offchannel_send_action_tx_status(
 158         struct wpa_supplicant *wpa_s, const u8 *dst, const u8 *data,
 159         size_t data_len, enum offchannel_send_action_result result)
 160 {
 161         if (wpa_s->pending_action_tx == NULL) {
 162                 wpa_printf(MSG_DEBUG, "Off-channel: Ignore Action TX status - "
 163                            "no pending operation");
 164                 return;
 165         }
 166
 167         if (os_memcmp(dst, wpa_s->pending_action_dst, ETH_ALEN) != 0) {
 168                 wpa_printf(MSG_DEBUG, "Off-channel: Ignore Action TX status - "
 169                            "unknown destination address");
 170                 return;
 171         }
 172
 173         /* Accept report only if the contents of the frame matches */
 174         if (data_len - wpabuf_len(wpa_s->pending_action_tx) != 24 ||
 175             os_memcmp(data + 24, wpabuf_head(wpa_s->pending_action_tx),
 176                       wpabuf_len(wpa_s->pending_action_tx)) != 0) {
 177                 wpa_printf(MSG_DEBUG, "Off-channel: Ignore Action TX status - "
 178                                    "mismatching contents with pending frame");
 179                 wpa_hexdump(MSG_MSGDUMP, "TX status frame data",
 180                             data, data_len);
 181                 wpa_hexdump_buf(MSG_MSGDUMP, "Pending TX frame",
 182                                 wpa_s->pending_action_tx);
 183                 return;
 184         }
 185
 186         wpa_printf(MSG_DEBUG, "Off-channel: Delete matching pending action frame");
 187
 188         wpabuf_free(wpa_s->pending_action_tx);
 189         wpa_s->pending_action_tx = NULL;
 190
 191         wpa_printf(MSG_DEBUG, "Off-channel: TX status result=%d cb=%p",
 192                    result, wpa_s->pending_action_tx_status_cb);
 193
 194         if (wpa_s->pending_action_tx_status_cb) {
 195                 wpa_s->pending_action_tx_status_cb(
 196                         wpa_s, wpa_s->pending_action_freq,
 197                         wpa_s->pending_action_dst, wpa_s->pending_action_src,
 198                         wpa_s->pending_action_bssid,
 199                         data, data_len, result);
 200         }
 201 }
 202
 203
 204 /**
 205  * offchannel_send_action - Request off-channel Action frame TX
 206  * @wpa_s: Pointer to wpa_supplicant data
 207  * @freq: The frequency in MHz indicating the channel on which the frame is to
 208  *      transmitted or 0 for the current channel (only if associated)
 209  * @dst: Action frame destination MAC address
 210  * @src: Action frame source MAC address
 211  * @bssid: Action frame BSSID
 212  * @buf: Frame to transmit starting from the Category field
 213  * @len: Length of @buf in bytes
 214  * @wait_time: Wait time for response in milliseconds
 215  * @tx_cb: Callback function for indicating TX status or %NULL for now callback
 216  * @no_cck: Whether CCK rates are to be disallowed for TX rate selection
 217  * Returns: 0 on success or -1 on failure
 218  *
 219  * This function is used to request an Action frame to be transmitted on the
 220  * current operating channel or on another channel (off-channel). The actual
 221  * frame transmission will be delayed until the driver is ready on the specified
 222  * channel. The @wait_time parameter can be used to request the driver to remain
 223  * awake on the channel to wait for a response.
 224  */
 225 int offchannel_send_action(struct wpa_supplicant *wpa_s, unsigned int freq,
 226                            const u8 *dst, const u8 *src, const u8 *bssid,
 227                            const u8 *buf, size_t len, unsigned int wait_time,
 228                            void (*tx_cb)(struct wpa_supplicant *wpa_s,
 229                                          unsigned int freq, const u8 *dst,
 230                                          const u8 *src, const u8 *bssid,
 231                                          const u8 *data, size_t data_len,
 232                                          enum offchannel_send_action_result
 233                                          result),
 234                            int no_cck)
 235 {
 236         wpa_printf(MSG_DEBUG, "Off-channel: Send action frame: freq=%d dst="
 237                    MACSTR " src=" MACSTR " bssid=" MACSTR " len=%d",
 238                    freq, MAC2STR(dst), MAC2STR(src), MAC2STR(bssid),
 239                    (int) len);
 240
 241         wpa_s->pending_action_tx_status_cb = tx_cb;
 242
 243         if (wpa_s->pending_action_tx) {
 244                 wpa_printf(MSG_DEBUG, "Off-channel: Dropped pending Action "
 245                            "frame TX to " MACSTR,
 246                            MAC2STR(wpa_s->pending_action_dst));
 247                 wpabuf_free(wpa_s->pending_action_tx);
 248         }
 249         wpa_s->pending_action_tx_done = 0;
 250         wpa_s->pending_action_tx = wpabuf_alloc(len);
 251         if (wpa_s->pending_action_tx == NULL) {
 252                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to allocate Action "
 253                            "frame TX buffer (len=%llu)",
 254                            (unsigned long long) len);
 255                 return -1;
 256         }
 257         wpabuf_put_data(wpa_s->pending_action_tx, buf, len);
 258         os_memcpy(wpa_s->pending_action_src, src, ETH_ALEN);
 259         os_memcpy(wpa_s->pending_action_dst, dst, ETH_ALEN);
 260         os_memcpy(wpa_s->pending_action_bssid, bssid, ETH_ALEN);
 261         wpa_s->pending_action_freq = freq;
 262         wpa_s->pending_action_no_cck = no_cck;
 263
 264         if (freq != 0 && wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX) {
 265                 struct wpa_supplicant *iface;
 266                 int ret;
 267
 268                 iface = wpas_get_tx_interface(wpa_s,
 269                                               wpa_s->pending_action_src);
 270                 wpa_s->action_tx_wait_time = wait_time;
 271
 272                 ret = wpa_drv_send_action(
 273                         iface, wpa_s->pending_action_freq,
 274                         wait_time, wpa_s->pending_action_dst,
 275                         wpa_s->pending_action_src, wpa_s->pending_action_bssid,
 276                         wpabuf_head(wpa_s->pending_action_tx),
 277                         wpabuf_len(wpa_s->pending_action_tx),
 278                         wpa_s->pending_action_no_cck);
 279                 if (ret == 0)
 280                         wpa_s->pending_action_tx_done = 1;
 281                 return ret;
 282         }
 283
 284         if (freq) {
 285                 struct wpa_supplicant *tx_iface;
 286                 tx_iface = wpas_get_tx_interface(wpa_s, src);
 287                 if (tx_iface->assoc_freq == freq) {
 288                         wpa_printf(MSG_DEBUG, "Off-channel: Already on "
 289                                    "requested channel (TX interface operating "
 290                                    "channel)");
 291                         freq = 0;
 292                 }
 293         }
 294
 295         if (wpa_s->off_channel_freq == freq || freq == 0) {
 296                 wpa_printf(MSG_DEBUG, "Off-channel: Already on requested "
 297                            "channel; send Action frame immediately");
 298                 /* TODO: Would there ever be need to extend the current
 299                  * duration on the channel? */
 300                 wpa_s->pending_action_without_roc = 1;
 301                 eloop_cancel_timeout(wpas_send_action_cb, wpa_s, NULL);
 302                 eloop_register_timeout(0, 0, wpas_send_action_cb, wpa_s, NULL);
 303                 return 0;
 304         }
 305         wpa_s->pending_action_without_roc = 0;
 306
 307         if (wpa_s->roc_waiting_drv_freq == freq) {
 308                 wpa_printf(MSG_DEBUG, "Off-channel: Already waiting for "
 309                            "driver to get to frequency %u MHz; continue "
 310                            "waiting to send the Action frame", freq);
 311                 return 0;
 312         }
 313
 314         wpa_printf(MSG_DEBUG, "Off-channel: Schedule Action frame to be "
 315                    "transmitted once the driver gets to the requested "
 316                    "channel");
 317         if (wait_time > wpa_s->max_remain_on_chan)
 318                 wait_time = wpa_s->max_remain_on_chan;
 319         else if (wait_time == 0)
 320                 wait_time = 20;
 321 #ifdef CONFIG_TESTING_OPTIONS
 322         if (wpa_s->extra_roc_dur) {
 323                 wpa_printf(MSG_DEBUG, "TESTING: Increase ROC duration %u -> %u",
 324                            wait_time, wait_time + wpa_s->extra_roc_dur);
 325                 wait_time += wpa_s->extra_roc_dur;
 326         }
 327 #endif /* CONFIG_TESTING_OPTIONS */
 328         if (wpa_drv_remain_on_channel(wpa_s, freq, wait_time) < 0) {
 329                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to request driver "
 330                            "to remain on channel (%u MHz) for Action "
 331                            "Frame TX", freq);
 332                 return -1;
 333         }
 334         wpa_s->off_channel_freq = 0;
 335         wpa_s->roc_waiting_drv_freq = freq;
 336
 337         return 0;
 338 }
 339
 340
 341 /**
 342  * offchannel_send_send_action_done - Notify completion of Action frame sequence
 343  * @wpa_s: Pointer to wpa_supplicant data
 344  *
 345  * This function can be used to cancel a wait for additional response frames on
 346  * the channel that was used with offchannel_send_action().
 347  */
 348 void offchannel_send_action_done(struct wpa_supplicant *wpa_s)
 349 {
 350         wpa_printf(MSG_DEBUG, "Off-channel: Action frame sequence done "
 351                    "notification");
 352         wpabuf_free(wpa_s->pending_action_tx);
 353         wpa_s->pending_action_tx = NULL;
 354         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX &&
 355             wpa_s->action_tx_wait_time)
 356                 wpa_drv_send_action_cancel_wait(wpa_s);
 357
 358         if (wpa_s->off_channel_freq || wpa_s->roc_waiting_drv_freq) {
 359                 wpa_drv_cancel_remain_on_channel(wpa_s);
 360                 wpa_s->off_channel_freq = 0;
 361                 wpa_s->roc_waiting_drv_freq = 0;
 362         }
 363 }
 364
 365
 366 /**
 367  * offchannel_remain_on_channel_cb - Remain-on-channel callback function
 368  * @wpa_s: Pointer to wpa_supplicant data
 369  * @freq: Frequency (in MHz) of the selected channel
 370  * @duration: Duration of the remain-on-channel operation in milliseconds
 371  *
 372  * This function is called whenever the driver notifies beginning of a
 373  * remain-on-channel operation.
 374  */
 375 void offchannel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
 376                                      unsigned int freq, unsigned int duration)
 377 {
 378         wpa_s->roc_waiting_drv_freq = 0;
 379         wpa_s->off_channel_freq = freq;
 380         wpas_send_action_cb(wpa_s, NULL);
 381 }
 382
 383
 384 /**
 385  * offchannel_cancel_remain_on_channel_cb - Remain-on-channel stopped callback
 386  * @wpa_s: Pointer to wpa_supplicant data
 387  * @freq: Frequency (in MHz) of the selected channel
 388  *
 389  * This function is called whenever the driver notifies termination of a
 390  * remain-on-channel operation.
 391  */
 392 void offchannel_cancel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
 393                                             unsigned int freq)
 394 {
 395         wpa_s->off_channel_freq = 0;
 396 }
 397
 398
 399 /**
 400  * offchannel_pending_action_tx - Check whether there is a pending Action TX
 401  * @wpa_s: Pointer to wpa_supplicant data
 402  * Returns: Pointer to pending frame or %NULL if no pending operation
 403  *
 404  * This function can be used to check whether there is a pending Action frame TX
 405  * operation. The returned pointer should be used only for checking whether it
 406  * is %NULL (no pending frame) or to print the pointer value in debug
 407  * information (i.e., the pointer should not be dereferenced).
 408  */
 409 const void * offchannel_pending_action_tx(struct wpa_supplicant *wpa_s)
 410 {
 411         return wpa_s->pending_action_tx;
 412 }
 413
 414
 415 /**
 416  * offchannel_clear_pending_action_tx - Clear pending Action frame TX
 417  * @wpa_s: Pointer to wpa_supplicant data
 418  */
 419 void offchannel_clear_pending_action_tx(struct wpa_supplicant *wpa_s)
 420 {
 421         wpabuf_free(wpa_s->pending_action_tx);
 422         wpa_s->pending_action_tx = NULL;
 423 }
 424
 425
 426 /**
 427  * offchannel_deinit - Deinit off-channel operations
 428  * @wpa_s: Pointer to wpa_supplicant data
 429  *
 430  * This function is used to free up any allocated resources for off-channel
 431  * operations.
 432  */
 433 void offchannel_deinit(struct wpa_supplicant *wpa_s)
 434 {
 435         offchannel_clear_pending_action_tx(wpa_s);
 436         eloop_cancel_timeout(wpas_send_action_cb, wpa_s, NULL);
 437 }