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 "p2p_supplicant.h"
  16 #include "driver_i.h"
  17 #include "offchannel.h"
  18
  19
  20
  21 static struct wpa_supplicant *
  22 wpas_get_tx_interface(struct wpa_supplicant *wpa_s, const u8 *src)
  23 {
  24         struct wpa_supplicant *iface;
  25
  26         if (os_memcmp(src, wpa_s->own_addr, ETH_ALEN) == 0) {
  27 #ifdef CONFIG_P2P
  28                 if (wpa_s->p2p_mgmt && wpa_s != wpa_s->parent &&
  29                     wpa_s->parent->ap_iface &&
  30                     os_memcmp(wpa_s->parent->own_addr,
  31                               wpa_s->own_addr, ETH_ALEN) == 0 &&
  32                     wpabuf_len(wpa_s->pending_action_tx) >= 2 &&
  33                     *wpabuf_head_u8(wpa_s->pending_action_tx) !=
  34                     WLAN_ACTION_PUBLIC) {
  35                         /*
  36                          * When P2P Device interface has same MAC address as
  37                          * the GO interface, make sure non-Public Action frames
  38                          * are sent through the GO interface. The P2P Device
  39                          * interface can only send Public Action frames.
  40                          */
  41                         wpa_printf(MSG_DEBUG,
  42                                    "P2P: Use GO interface %s instead of interface %s for Action TX",
  43                                    wpa_s->parent->ifname, wpa_s->ifname);
  44                         return wpa_s->parent;
  45                 }
  46 #endif /* CONFIG_P2P */
  47                 return wpa_s;
  48         }
  49
  50         /*
  51          * Try to find a group interface that matches with the source address.
  52          */
  53         iface = wpa_s->global->ifaces;
  54         while (iface) {
  55                 if (os_memcmp(src, iface->own_addr, ETH_ALEN) == 0)
  56                         break;
  57                 iface = iface->next;
  58         }
  59         if (iface) {
  60                 wpa_printf(MSG_DEBUG, "P2P: Use group interface %s "
  61                            "instead of interface %s for Action TX",
  62                            iface->ifname, wpa_s->ifname);
  63                 return iface;
  64         }
  65
  66         return wpa_s;
  67 }
  68
  69
  70 static void wpas_send_action_cb(void *eloop_ctx, void *timeout_ctx)
  71 {
  72         struct wpa_supplicant *wpa_s = eloop_ctx;
  73         struct wpa_supplicant *iface;
  74         int res;
  75         int without_roc;
  76
  77         without_roc = wpa_s->pending_action_without_roc;
  78         wpa_s->pending_action_without_roc = 0;
  79         wpa_printf(MSG_DEBUG,
  80                    "Off-channel: Send Action callback (without_roc=%d pending_action_tx=%p pending_action_tx_done=%d)",
  81                    without_roc, wpa_s->pending_action_tx,
  82                    !!wpa_s->pending_action_tx_done);
  83
  84         if (wpa_s->pending_action_tx == NULL || wpa_s->pending_action_tx_done)
  85                 return;
  86
  87         /*
  88          * This call is likely going to be on the P2P device instance if the
  89          * driver uses a separate interface for that purpose. However, some
  90          * Action frames are actually sent within a P2P Group and when that is
  91          * the case, we need to follow power saving (e.g., GO buffering the
  92          * frame for a client in PS mode or a client following the advertised
  93          * NoA from its GO). To make that easier for the driver, select the
  94          * correct group interface here.
  95          */
  96         iface = wpas_get_tx_interface(wpa_s, wpa_s->pending_action_src);
  97
  98         if (wpa_s->off_channel_freq != wpa_s->pending_action_freq &&
  99             wpa_s->pending_action_freq != 0 &&
 100             wpa_s->pending_action_freq != iface->assoc_freq) {
 101                 wpa_printf(MSG_DEBUG, "Off-channel: Pending Action frame TX "
 102                            "waiting for another freq=%u (off_channel_freq=%u "
 103                            "assoc_freq=%u)",
 104                            wpa_s->pending_action_freq,
 105                            wpa_s->off_channel_freq,
 106                            iface->assoc_freq);
 107                 if (without_roc && wpa_s->off_channel_freq == 0) {
 108                         unsigned int duration = 200;
 109                         /*
 110                          * We may get here if wpas_send_action() found us to be
 111                          * on the correct channel, but remain-on-channel cancel
 112                          * event was received before getting here.
 113                          */
 114                         wpa_printf(MSG_DEBUG, "Off-channel: Schedule "
 115                                    "remain-on-channel to send Action frame");
 116 #ifdef CONFIG_TESTING_OPTIONS
 117                         if (wpa_s->extra_roc_dur) {
 118                                 wpa_printf(MSG_DEBUG,
 119                                            "TESTING: Increase ROC duration %u -> %u",
 120                                            duration,
 121                                            duration + wpa_s->extra_roc_dur);
 122                                 duration += wpa_s->extra_roc_dur;
 123         }
 124 #endif /* CONFIG_TESTING_OPTIONS */
 125                         if (wpa_drv_remain_on_channel(
 126                                     wpa_s, wpa_s->pending_action_freq,
 127                                     duration) < 0) {
 128                                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to "
 129                                            "request driver to remain on "
 130                                            "channel (%u MHz) for Action Frame "
 131                                            "TX", wpa_s->pending_action_freq);
 132                         } else {
 133                                 wpa_s->off_channel_freq = 0;
 134                                 wpa_s->roc_waiting_drv_freq =
 135                                         wpa_s->pending_action_freq;
 136                         }
 137                 }
 138                 return;
 139         }
 140
 141         wpa_printf(MSG_DEBUG, "Off-channel: Sending pending Action frame to "
 142                    MACSTR " using interface %s (pending_action_tx=%p)",
 143                    MAC2STR(wpa_s->pending_action_dst), iface->ifname,
 144                    wpa_s->pending_action_tx);
 145         res = wpa_drv_send_action(iface, wpa_s->pending_action_freq, 0,
 146                                   wpa_s->pending_action_dst,
 147                                   wpa_s->pending_action_src,
 148                                   wpa_s->pending_action_bssid,
 149                                   wpabuf_head(wpa_s->pending_action_tx),
 150                                   wpabuf_len(wpa_s->pending_action_tx),
 151                                   wpa_s->pending_action_no_cck);
 152         if (res) {
 153                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to send the "
 154                            "pending Action frame");
 155                 /*
 156                  * Use fake TX status event to allow state machines to
 157                  * continue.
 158                  */
 159                 offchannel_send_action_tx_status(
 160                         wpa_s, wpa_s->pending_action_dst,
 161                         wpabuf_head(wpa_s->pending_action_tx),
 162                         wpabuf_len(wpa_s->pending_action_tx),
 163                         OFFCHANNEL_SEND_ACTION_FAILED);
 164         }
 165 }
 166
 167
 168 /**
 169  * offchannel_send_action_tx_status - TX status callback
 170  * @wpa_s: Pointer to wpa_supplicant data
 171  * @dst: Destination MAC address of the transmitted Action frame
 172  * @data: Transmitted frame payload
 173  * @data_len: Length of @data in bytes
 174  * @result: TX status
 175  *
 176  * This function is called whenever the driver indicates a TX status event for
 177  * a frame sent by offchannel_send_action() using wpa_drv_send_action().
 178  */
 179 void offchannel_send_action_tx_status(
 180         struct wpa_supplicant *wpa_s, const u8 *dst, const u8 *data,
 181         size_t data_len, enum offchannel_send_action_result result)
 182 {
 183         if (wpa_s->pending_action_tx == NULL) {
 184                 wpa_printf(MSG_DEBUG, "Off-channel: Ignore Action TX status - "
 185                            "no pending operation");
 186                 return;
 187         }
 188
 189         if (os_memcmp(dst, wpa_s->pending_action_dst, ETH_ALEN) != 0) {
 190                 wpa_printf(MSG_DEBUG, "Off-channel: Ignore Action TX status - "
 191                            "unknown destination address");
 192                 return;
 193         }
 194
 195         /* Accept report only if the contents of the frame matches */
 196         if (data_len - wpabuf_len(wpa_s->pending_action_tx) != 24 ||
 197             os_memcmp(data + 24, wpabuf_head(wpa_s->pending_action_tx),
 198                       wpabuf_len(wpa_s->pending_action_tx)) != 0) {
 199                 wpa_printf(MSG_DEBUG, "Off-channel: Ignore Action TX status - "
 200                                    "mismatching contents with pending frame");
 201                 wpa_hexdump(MSG_MSGDUMP, "TX status frame data",
 202                             data, data_len);
 203                 wpa_hexdump_buf(MSG_MSGDUMP, "Pending TX frame",
 204                                 wpa_s->pending_action_tx);
 205                 return;
 206         }
 207
 208         wpa_printf(MSG_DEBUG,
 209                    "Off-channel: Delete matching pending action frame (dst="
 210                    MACSTR " pending_action_tx=%p)", MAC2STR(dst),
 211                    wpa_s->pending_action_tx);
 212         wpa_hexdump_buf(MSG_MSGDUMP, "Pending TX frame",
 213                         wpa_s->pending_action_tx);
 214         wpabuf_free(wpa_s->pending_action_tx);
 215         wpa_s->pending_action_tx = NULL;
 216
 217         wpa_printf(MSG_DEBUG, "Off-channel: TX status result=%d cb=%p",
 218                    result, wpa_s->pending_action_tx_status_cb);
 219
 220         if (wpa_s->pending_action_tx_status_cb) {
 221                 wpa_s->pending_action_tx_status_cb(
 222                         wpa_s, wpa_s->pending_action_freq,
 223                         wpa_s->pending_action_dst, wpa_s->pending_action_src,
 224                         wpa_s->pending_action_bssid,
 225                         data, data_len, result);
 226         }
 227
 228 #ifdef CONFIG_P2P
 229         if (wpa_s->p2p_long_listen > 0) {
 230                 /* Continue the listen */
 231                 wpa_printf(MSG_DEBUG, "P2P: Continuing long Listen state");
 232                 wpas_p2p_listen_start(wpa_s, wpa_s->p2p_long_listen);
 233         }
 234 #endif /* CONFIG_P2P */
 235 }
 236
 237
 238 /**
 239  * offchannel_send_action - Request off-channel Action frame TX
 240  * @wpa_s: Pointer to wpa_supplicant data
 241  * @freq: The frequency in MHz indicating the channel on which the frame is to
 242  *      transmitted or 0 for the current channel (only if associated)
 243  * @dst: Action frame destination MAC address
 244  * @src: Action frame source MAC address
 245  * @bssid: Action frame BSSID
 246  * @buf: Frame to transmit starting from the Category field
 247  * @len: Length of @buf in bytes
 248  * @wait_time: Wait time for response in milliseconds
 249  * @tx_cb: Callback function for indicating TX status or %NULL for now callback
 250  * @no_cck: Whether CCK rates are to be disallowed for TX rate selection
 251  * Returns: 0 on success or -1 on failure
 252  *
 253  * This function is used to request an Action frame to be transmitted on the
 254  * current operating channel or on another channel (off-channel). The actual
 255  * frame transmission will be delayed until the driver is ready on the specified
 256  * channel. The @wait_time parameter can be used to request the driver to remain
 257  * awake on the channel to wait for a response.
 258  */
 259 int offchannel_send_action(struct wpa_supplicant *wpa_s, unsigned int freq,
 260                            const u8 *dst, const u8 *src, const u8 *bssid,
 261                            const u8 *buf, size_t len, unsigned int wait_time,
 262                            void (*tx_cb)(struct wpa_supplicant *wpa_s,
 263                                          unsigned int freq, const u8 *dst,
 264                                          const u8 *src, const u8 *bssid,
 265                                          const u8 *data, size_t data_len,
 266                                          enum offchannel_send_action_result
 267                                          result),
 268                            int no_cck)
 269 {
 270         wpa_printf(MSG_DEBUG, "Off-channel: Send action frame: freq=%d dst="
 271                    MACSTR " src=" MACSTR " bssid=" MACSTR " len=%d",
 272                    freq, MAC2STR(dst), MAC2STR(src), MAC2STR(bssid),
 273                    (int) len);
 274
 275         wpa_s->pending_action_tx_status_cb = tx_cb;
 276
 277         if (wpa_s->pending_action_tx) {
 278                 wpa_printf(MSG_DEBUG, "Off-channel: Dropped pending Action "
 279                            "frame TX to " MACSTR " (pending_action_tx=%p)",
 280                            MAC2STR(wpa_s->pending_action_dst),
 281                            wpa_s->pending_action_tx);
 282                 wpa_hexdump_buf(MSG_MSGDUMP, "Pending TX frame",
 283                                 wpa_s->pending_action_tx);
 284                 wpabuf_free(wpa_s->pending_action_tx);
 285         }
 286         wpa_s->pending_action_tx_done = 0;
 287         wpa_s->pending_action_tx = wpabuf_alloc(len);
 288         if (wpa_s->pending_action_tx == NULL) {
 289                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to allocate Action "
 290                            "frame TX buffer (len=%llu)",
 291                            (unsigned long long) len);
 292                 return -1;
 293         }
 294         wpabuf_put_data(wpa_s->pending_action_tx, buf, len);
 295         os_memcpy(wpa_s->pending_action_src, src, ETH_ALEN);
 296         os_memcpy(wpa_s->pending_action_dst, dst, ETH_ALEN);
 297         os_memcpy(wpa_s->pending_action_bssid, bssid, ETH_ALEN);
 298         wpa_s->pending_action_freq = freq;
 299         wpa_s->pending_action_no_cck = no_cck;
 300         wpa_printf(MSG_DEBUG,
 301                    "Off-channel: Stored pending action frame (dst=" MACSTR
 302                    " pending_action_tx=%p)",
 303                    MAC2STR(dst), wpa_s->pending_action_tx);
 304         wpa_hexdump_buf(MSG_MSGDUMP, "Pending TX frame",
 305                         wpa_s->pending_action_tx);
 306
 307         if (freq != 0 && wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX) {
 308                 struct wpa_supplicant *iface;
 309                 int ret;
 310
 311                 iface = wpas_get_tx_interface(wpa_s, src);
 312                 wpa_s->action_tx_wait_time = wait_time;
 313
 314                 ret = wpa_drv_send_action(
 315                         iface, wpa_s->pending_action_freq,
 316                         wait_time, wpa_s->pending_action_dst,
 317                         wpa_s->pending_action_src, wpa_s->pending_action_bssid,
 318                         wpabuf_head(wpa_s->pending_action_tx),
 319                         wpabuf_len(wpa_s->pending_action_tx),
 320                         wpa_s->pending_action_no_cck);
 321                 if (ret == 0)
 322                         wpa_s->pending_action_tx_done = 1;
 323                 return ret;
 324         }
 325
 326         if (freq) {
 327                 struct wpa_supplicant *tx_iface;
 328                 tx_iface = wpas_get_tx_interface(wpa_s, src);
 329                 if (tx_iface->assoc_freq == freq) {
 330                         wpa_printf(MSG_DEBUG, "Off-channel: Already on "
 331                                    "requested channel (TX interface operating "
 332                                    "channel)");
 333                         freq = 0;
 334                 }
 335         }
 336
 337         if (wpa_s->off_channel_freq == freq || freq == 0) {
 338                 wpa_printf(MSG_DEBUG, "Off-channel: Already on requested "
 339                            "channel; send Action frame immediately");
 340                 /* TODO: Would there ever be need to extend the current
 341                  * duration on the channel? */
 342                 wpa_s->pending_action_without_roc = 1;
 343                 eloop_cancel_timeout(wpas_send_action_cb, wpa_s, NULL);
 344                 eloop_register_timeout(0, 0, wpas_send_action_cb, wpa_s, NULL);
 345                 return 0;
 346         }
 347         wpa_s->pending_action_without_roc = 0;
 348
 349         if (wpa_s->roc_waiting_drv_freq == freq) {
 350                 wpa_printf(MSG_DEBUG, "Off-channel: Already waiting for "
 351                            "driver to get to frequency %u MHz; continue "
 352                            "waiting to send the Action frame", freq);
 353                 return 0;
 354         }
 355
 356         wpa_printf(MSG_DEBUG, "Off-channel: Schedule Action frame to be "
 357                    "transmitted once the driver gets to the requested "
 358                    "channel");
 359         if (wait_time > wpa_s->max_remain_on_chan)
 360                 wait_time = wpa_s->max_remain_on_chan;
 361         else if (wait_time == 0)
 362                 wait_time = 20;
 363 #ifdef CONFIG_TESTING_OPTIONS
 364         if (wpa_s->extra_roc_dur) {
 365                 wpa_printf(MSG_DEBUG, "TESTING: Increase ROC duration %u -> %u",
 366                            wait_time, wait_time + wpa_s->extra_roc_dur);
 367                 wait_time += wpa_s->extra_roc_dur;
 368         }
 369 #endif /* CONFIG_TESTING_OPTIONS */
 370         if (wpa_drv_remain_on_channel(wpa_s, freq, wait_time) < 0) {
 371                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to request driver "
 372                            "to remain on channel (%u MHz) for Action "
 373                            "Frame TX", freq);
 374                 return -1;
 375         }
 376         wpa_s->off_channel_freq = 0;
 377         wpa_s->roc_waiting_drv_freq = freq;
 378
 379         return 0;
 380 }
 381
 382
 383 /**
 384  * offchannel_send_send_action_done - Notify completion of Action frame sequence
 385  * @wpa_s: Pointer to wpa_supplicant data
 386  *
 387  * This function can be used to cancel a wait for additional response frames on
 388  * the channel that was used with offchannel_send_action().
 389  */
 390 void offchannel_send_action_done(struct wpa_supplicant *wpa_s)
 391 {
 392         wpa_printf(MSG_DEBUG,
 393                    "Off-channel: Action frame sequence done notification: pending_action_tx=%p drv_offchan_tx=%d action_tx_wait_time=%d off_channel_freq=%d roc_waiting_drv_freq=%d",
 394                    wpa_s->pending_action_tx,
 395                    !!(wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX),
 396                    wpa_s->action_tx_wait_time, wpa_s->off_channel_freq,
 397                    wpa_s->roc_waiting_drv_freq);
 398         wpabuf_free(wpa_s->pending_action_tx);
 399         wpa_s->pending_action_tx = NULL;
 400         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX &&
 401             wpa_s->action_tx_wait_time)
 402                 wpa_drv_send_action_cancel_wait(wpa_s);
 403         else if (wpa_s->off_channel_freq || wpa_s->roc_waiting_drv_freq) {
 404                 wpa_drv_cancel_remain_on_channel(wpa_s);
 405                 wpa_s->off_channel_freq = 0;
 406                 wpa_s->roc_waiting_drv_freq = 0;
 407         }
 408 }
 409
 410
 411 /**
 412  * offchannel_remain_on_channel_cb - Remain-on-channel callback function
 413  * @wpa_s: Pointer to wpa_supplicant data
 414  * @freq: Frequency (in MHz) of the selected channel
 415  * @duration: Duration of the remain-on-channel operation in milliseconds
 416  *
 417  * This function is called whenever the driver notifies beginning of a
 418  * remain-on-channel operation.
 419  */
 420 void offchannel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
 421                                      unsigned int freq, unsigned int duration)
 422 {
 423         wpa_s->roc_waiting_drv_freq = 0;
 424         wpa_s->off_channel_freq = freq;
 425         wpas_send_action_cb(wpa_s, NULL);
 426 }
 427
 428
 429 /**
 430  * offchannel_cancel_remain_on_channel_cb - Remain-on-channel stopped callback
 431  * @wpa_s: Pointer to wpa_supplicant data
 432  * @freq: Frequency (in MHz) of the selected channel
 433  *
 434  * This function is called whenever the driver notifies termination of a
 435  * remain-on-channel operation.
 436  */
 437 void offchannel_cancel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
 438                                             unsigned int freq)
 439 {
 440         wpa_s->off_channel_freq = 0;
 441 }
 442
 443
 444 /**
 445  * offchannel_pending_action_tx - Check whether there is a pending Action TX
 446  * @wpa_s: Pointer to wpa_supplicant data
 447  * Returns: Pointer to pending frame or %NULL if no pending operation
 448  *
 449  * This function can be used to check whether there is a pending Action frame TX
 450  * operation. The returned pointer should be used only for checking whether it
 451  * is %NULL (no pending frame) or to print the pointer value in debug
 452  * information (i.e., the pointer should not be dereferenced).
 453  */
 454 const void * offchannel_pending_action_tx(struct wpa_supplicant *wpa_s)
 455 {
 456         return wpa_s->pending_action_tx;
 457 }
 458
 459
 460 /**
 461  * offchannel_clear_pending_action_tx - Clear pending Action frame TX
 462  * @wpa_s: Pointer to wpa_supplicant data
 463  */
 464 void offchannel_clear_pending_action_tx(struct wpa_supplicant *wpa_s)
 465 {
 466         wpa_printf(MSG_DEBUG,
 467                    "Off-channel: Clear pending Action frame TX (pending_action_tx=%p",
 468                    wpa_s->pending_action_tx);
 469         wpabuf_free(wpa_s->pending_action_tx);
 470         wpa_s->pending_action_tx = NULL;
 471 }
 472
 473
 474 /**
 475  * offchannel_deinit - Deinit off-channel operations
 476  * @wpa_s: Pointer to wpa_supplicant data
 477  *
 478  * This function is used to free up any allocated resources for off-channel
 479  * operations.
 480  */
 481 void offchannel_deinit(struct wpa_supplicant *wpa_s)
 482 {
 483         offchannel_clear_pending_action_tx(wpa_s);
 484         eloop_cancel_timeout(wpas_send_action_cb, wpa_s, NULL);
 485 }