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