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                         /*
  88                          * We may get here if wpas_send_action() found us to be
  89                          * on the correct channel, but remain-on-channel cancel
  90                          * event was received before getting here.
  91                          */
  92                         wpa_printf(MSG_DEBUG, "Off-channel: Schedule "
  93                                    "remain-on-channel to send Action frame");
  94                         if (wpa_drv_remain_on_channel(
  95                                     wpa_s, wpa_s->pending_action_freq, 200) <
  96                             0) {
  97                                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to "
  98                                            "request driver to remain on "
  99                                            "channel (%u MHz) for Action Frame "
 100                                            "TX", wpa_s->pending_action_freq);
 101                         } else {
 102                                 wpa_s->off_channel_freq = 0;
 103                                 wpa_s->roc_waiting_drv_freq =
 104                                         wpa_s->pending_action_freq;
 105                         }
 106                 }
 107                 return;
 108         }
 109
 110         wpa_printf(MSG_DEBUG, "Off-channel: Sending pending Action frame to "
 111                    MACSTR " using interface %s",
 112                    MAC2STR(wpa_s->pending_action_dst), iface->ifname);
 113         res = wpa_drv_send_action(iface, wpa_s->pending_action_freq, 0,
 114                                   wpa_s->pending_action_dst,
 115                                   wpa_s->pending_action_src,
 116                                   wpa_s->pending_action_bssid,
 117                                   wpabuf_head(wpa_s->pending_action_tx),
 118                                   wpabuf_len(wpa_s->pending_action_tx),
 119                                   wpa_s->pending_action_no_cck);
 120         if (res) {
 121                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to send the "
 122                            "pending Action frame");
 123                 /*
 124                  * Use fake TX status event to allow state machines to
 125                  * continue.
 126                  */
 127                 offchannel_send_action_tx_status(
 128                         wpa_s, wpa_s->pending_action_dst,
 129                         wpabuf_head(wpa_s->pending_action_tx),
 130                         wpabuf_len(wpa_s->pending_action_tx),
 131                         OFFCHANNEL_SEND_ACTION_FAILED);
 132         }
 133 }
 134
 135
 136 /**
 137  * offchannel_send_action_tx_status - TX status callback
 138  * @wpa_s: Pointer to wpa_supplicant data
 139  * @dst: Destination MAC address of the transmitted Action frame
 140  * @data: Transmitted frame payload
 141  * @data_len: Length of @data in bytes
 142  * @result: TX status
 143  *
 144  * This function is called whenever the driver indicates a TX status event for
 145  * a frame sent by offchannel_send_action() using wpa_drv_send_action().
 146  */
 147 void offchannel_send_action_tx_status(
 148         struct wpa_supplicant *wpa_s, const u8 *dst, const u8 *data,
 149         size_t data_len, enum offchannel_send_action_result result)
 150 {
 151         if (wpa_s->pending_action_tx == NULL) {
 152                 wpa_printf(MSG_DEBUG, "Off-channel: Ignore Action TX status - "
 153                            "no pending operation");
 154                 return;
 155         }
 156
 157         if (os_memcmp(dst, wpa_s->pending_action_dst, ETH_ALEN) != 0) {
 158                 wpa_printf(MSG_DEBUG, "Off-channel: Ignore Action TX status - "
 159                            "unknown destination address");
 160                 return;
 161         }
 162
 163         /* Accept report only if the contents of the frame matches */
 164         if (data_len - wpabuf_len(wpa_s->pending_action_tx) != 24 ||
 165             os_memcmp(data + 24, wpabuf_head(wpa_s->pending_action_tx),
 166                       wpabuf_len(wpa_s->pending_action_tx)) != 0) {
 167                 wpa_printf(MSG_DEBUG, "Off-channel: Ignore Action TX status - "
 168                                    "mismatching contents with pending frame");
 169                 wpa_hexdump(MSG_MSGDUMP, "TX status frame data",
 170                             data, data_len);
 171                 wpa_hexdump_buf(MSG_MSGDUMP, "Pending TX frame",
 172                                 wpa_s->pending_action_tx);
 173                 return;
 174         }
 175
 176         wpa_printf(MSG_DEBUG, "Off-channel: Delete matching pending action frame");
 177
 178         wpabuf_free(wpa_s->pending_action_tx);
 179         wpa_s->pending_action_tx = NULL;
 180
 181         wpa_printf(MSG_DEBUG, "Off-channel: TX status result=%d cb=%p",
 182                    result, wpa_s->pending_action_tx_status_cb);
 183
 184         if (wpa_s->pending_action_tx_status_cb) {
 185                 wpa_s->pending_action_tx_status_cb(
 186                         wpa_s, wpa_s->pending_action_freq,
 187                         wpa_s->pending_action_dst, wpa_s->pending_action_src,
 188                         wpa_s->pending_action_bssid,
 189                         data, data_len, result);
 190         }
 191 }
 192
 193
 194 /**
 195  * offchannel_send_action - Request off-channel Action frame TX
 196  * @wpa_s: Pointer to wpa_supplicant data
 197  * @freq: The frequency in MHz indicating the channel on which the frame is to
 198  *      transmitted or 0 for the current channel (only if associated)
 199  * @dst: Action frame destination MAC address
 200  * @src: Action frame source MAC address
 201  * @bssid: Action frame BSSID
 202  * @buf: Frame to transmit starting from the Category field
 203  * @len: Length of @buf in bytes
 204  * @wait_time: Wait time for response in milliseconds
 205  * @tx_cb: Callback function for indicating TX status or %NULL for now callback
 206  * @no_cck: Whether CCK rates are to be disallowed for TX rate selection
 207  * Returns: 0 on success or -1 on failure
 208  *
 209  * This function is used to request an Action frame to be transmitted on the
 210  * current operating channel or on another channel (off-channel). The actual
 211  * frame transmission will be delayed until the driver is ready on the specified
 212  * channel. The @wait_time parameter can be used to request the driver to remain
 213  * awake on the channel to wait for a response.
 214  */
 215 int offchannel_send_action(struct wpa_supplicant *wpa_s, unsigned int freq,
 216                            const u8 *dst, const u8 *src, const u8 *bssid,
 217                            const u8 *buf, size_t len, unsigned int wait_time,
 218                            void (*tx_cb)(struct wpa_supplicant *wpa_s,
 219                                          unsigned int freq, const u8 *dst,
 220                                          const u8 *src, const u8 *bssid,
 221                                          const u8 *data, size_t data_len,
 222                                          enum offchannel_send_action_result
 223                                          result),
 224                            int no_cck)
 225 {
 226         wpa_printf(MSG_DEBUG, "Off-channel: Send action frame: freq=%d dst="
 227                    MACSTR " src=" MACSTR " bssid=" MACSTR " len=%d",
 228                    freq, MAC2STR(dst), MAC2STR(src), MAC2STR(bssid),
 229                    (int) len);
 230
 231         wpa_s->pending_action_tx_status_cb = tx_cb;
 232
 233         if (wpa_s->pending_action_tx) {
 234                 wpa_printf(MSG_DEBUG, "Off-channel: Dropped pending Action "
 235                            "frame TX to " MACSTR,
 236                            MAC2STR(wpa_s->pending_action_dst));
 237                 wpabuf_free(wpa_s->pending_action_tx);
 238         }
 239         wpa_s->pending_action_tx_done = 0;
 240         wpa_s->pending_action_tx = wpabuf_alloc(len);
 241         if (wpa_s->pending_action_tx == NULL) {
 242                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to allocate Action "
 243                            "frame TX buffer (len=%llu)",
 244                            (unsigned long long) len);
 245                 return -1;
 246         }
 247         wpabuf_put_data(wpa_s->pending_action_tx, buf, len);
 248         os_memcpy(wpa_s->pending_action_src, src, ETH_ALEN);
 249         os_memcpy(wpa_s->pending_action_dst, dst, ETH_ALEN);
 250         os_memcpy(wpa_s->pending_action_bssid, bssid, ETH_ALEN);
 251         wpa_s->pending_action_freq = freq;
 252         wpa_s->pending_action_no_cck = no_cck;
 253
 254         if (freq != 0 && wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX) {
 255                 struct wpa_supplicant *iface;
 256                 int ret;
 257
 258                 iface = wpas_get_tx_interface(wpa_s,
 259                                               wpa_s->pending_action_src);
 260                 wpa_s->action_tx_wait_time = wait_time;
 261
 262                 ret = wpa_drv_send_action(
 263                         iface, wpa_s->pending_action_freq,
 264                         wait_time, wpa_s->pending_action_dst,
 265                         wpa_s->pending_action_src, wpa_s->pending_action_bssid,
 266                         wpabuf_head(wpa_s->pending_action_tx),
 267                         wpabuf_len(wpa_s->pending_action_tx),
 268                         wpa_s->pending_action_no_cck);
 269                 if (ret == 0)
 270                         wpa_s->pending_action_tx_done = 1;
 271                 return ret;
 272         }
 273
 274         if (freq) {
 275                 struct wpa_supplicant *tx_iface;
 276                 tx_iface = wpas_get_tx_interface(wpa_s, src);
 277                 if (tx_iface->assoc_freq == freq) {
 278                         wpa_printf(MSG_DEBUG, "Off-channel: Already on "
 279                                    "requested channel (TX interface operating "
 280                                    "channel)");
 281                         freq = 0;
 282                 }
 283         }
 284
 285         if (wpa_s->off_channel_freq == freq || freq == 0) {
 286                 wpa_printf(MSG_DEBUG, "Off-channel: Already on requested "
 287                            "channel; send Action frame immediately");
 288                 /* TODO: Would there ever be need to extend the current
 289                  * duration on the channel? */
 290                 wpa_s->pending_action_without_roc = 1;
 291                 eloop_cancel_timeout(wpas_send_action_cb, wpa_s, NULL);
 292                 eloop_register_timeout(0, 0, wpas_send_action_cb, wpa_s, NULL);
 293                 return 0;
 294         }
 295         wpa_s->pending_action_without_roc = 0;
 296
 297         if (wpa_s->roc_waiting_drv_freq == freq) {
 298                 wpa_printf(MSG_DEBUG, "Off-channel: Already waiting for "
 299                            "driver to get to frequency %u MHz; continue "
 300                            "waiting to send the Action frame", freq);
 301                 return 0;
 302         }
 303
 304         wpa_printf(MSG_DEBUG, "Off-channel: Schedule Action frame to be "
 305                    "transmitted once the driver gets to the requested "
 306                    "channel");
 307         if (wait_time > wpa_s->max_remain_on_chan)
 308                 wait_time = wpa_s->max_remain_on_chan;
 309         else if (wait_time == 0)
 310                 wait_time = 20;
 311         if (wpa_drv_remain_on_channel(wpa_s, freq, wait_time) < 0) {
 312                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to request driver "
 313                            "to remain on channel (%u MHz) for Action "
 314                            "Frame TX", freq);
 315                 return -1;
 316         }
 317         wpa_s->off_channel_freq = 0;
 318         wpa_s->roc_waiting_drv_freq = freq;
 319
 320         return 0;
 321 }
 322
 323
 324 /**
 325  * offchannel_send_send_action_done - Notify completion of Action frame sequence
 326  * @wpa_s: Pointer to wpa_supplicant data
 327  *
 328  * This function can be used to cancel a wait for additional response frames on
 329  * the channel that was used with offchannel_send_action().
 330  */
 331 void offchannel_send_action_done(struct wpa_supplicant *wpa_s)
 332 {
 333         wpa_printf(MSG_DEBUG, "Off-channel: Action frame sequence done "
 334                    "notification");
 335         wpabuf_free(wpa_s->pending_action_tx);
 336         wpa_s->pending_action_tx = NULL;
 337         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX &&
 338             wpa_s->action_tx_wait_time)
 339                 wpa_drv_send_action_cancel_wait(wpa_s);
 340
 341         if (wpa_s->off_channel_freq || wpa_s->roc_waiting_drv_freq) {
 342                 wpa_drv_cancel_remain_on_channel(wpa_s);
 343                 wpa_s->off_channel_freq = 0;
 344                 wpa_s->roc_waiting_drv_freq = 0;
 345         }
 346 }
 347
 348
 349 /**
 350  * offchannel_remain_on_channel_cb - Remain-on-channel callback function
 351  * @wpa_s: Pointer to wpa_supplicant data
 352  * @freq: Frequency (in MHz) of the selected channel
 353  * @duration: Duration of the remain-on-channel operation in milliseconds
 354  *
 355  * This function is called whenever the driver notifies beginning of a
 356  * remain-on-channel operation.
 357  */
 358 void offchannel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
 359                                      unsigned int freq, unsigned int duration)
 360 {
 361         wpa_s->roc_waiting_drv_freq = 0;
 362         wpa_s->off_channel_freq = freq;
 363         wpas_send_action_cb(wpa_s, NULL);
 364 }
 365
 366
 367 /**
 368  * offchannel_cancel_remain_on_channel_cb - Remain-on-channel stopped callback
 369  * @wpa_s: Pointer to wpa_supplicant data
 370  * @freq: Frequency (in MHz) of the selected channel
 371  *
 372  * This function is called whenever the driver notifies termination of a
 373  * remain-on-channel operation.
 374  */
 375 void offchannel_cancel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
 376                                             unsigned int freq)
 377 {
 378         wpa_s->off_channel_freq = 0;
 379 }
 380
 381
 382 /**
 383  * offchannel_pending_action_tx - Check whether there is a pending Action TX
 384  * @wpa_s: Pointer to wpa_supplicant data
 385  * Returns: Pointer to pending frame or %NULL if no pending operation
 386  *
 387  * This function can be used to check whether there is a pending Action frame TX
 388  * operation. The returned pointer should be used only for checking whether it
 389  * is %NULL (no pending frame) or to print the pointer value in debug
 390  * information (i.e., the pointer should not be dereferenced).
 391  */
 392 const void * offchannel_pending_action_tx(struct wpa_supplicant *wpa_s)
 393 {
 394         return wpa_s->pending_action_tx;
 395 }
 396
 397
 398 /**
 399  * offchannel_clear_pending_action_tx - Clear pending Action frame TX
 400  * @wpa_s: Pointer to wpa_supplicant data
 401  */
 402 void offchannel_clear_pending_action_tx(struct wpa_supplicant *wpa_s)
 403 {
 404         wpabuf_free(wpa_s->pending_action_tx);
 405         wpa_s->pending_action_tx = NULL;
 406 }
 407
 408
 409 /**
 410  * offchannel_deinit - Deinit off-channel operations
 411  * @wpa_s: Pointer to wpa_supplicant data
 412  *
 413  * This function is used to free up any allocated resources for off-channel
 414  * operations.
 415  */
 416 void offchannel_deinit(struct wpa_supplicant *wpa_s)
 417 {
 418         offchannel_clear_pending_action_tx(wpa_s);
 419         eloop_cancel_timeout(wpas_send_action_cb, wpa_s, NULL);
 420 }