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      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 	else if (wait_time == 0)
    289 		wait_time = 20;
    290 	if (wpa_drv_remain_on_channel(wpa_s, freq, wait_time) < 0) {
    291 		wpa_printf(MSG_DEBUG, "Off-channel: Failed to request driver "
    292 			   "to remain on channel (%u MHz) for Action "
    293 			   "Frame TX", freq);
    294 		return -1;
    295 	}
    296 	wpa_s->off_channel_freq = 0;
    297 	wpa_s->roc_waiting_drv_freq = freq;
    298 
    299 	return 0;
    300 }
    301 
    302 
    303 /**
    304  * offchannel_send_send_action_done - Notify completion of Action frame sequence
    305  * @wpa_s: Pointer to wpa_supplicant data
    306  *
    307  * This function can be used to cancel a wait for additional response frames on
    308  * the channel that was used with offchannel_send_action().
    309  */
    310 void offchannel_send_action_done(struct wpa_supplicant *wpa_s)
    311 {
    312 	wpa_printf(MSG_DEBUG, "Off-channel: Action frame sequence done "
    313 		   "notification");
    314 	wpabuf_free(wpa_s->pending_action_tx);
    315 	wpa_s->pending_action_tx = NULL;
    316 	if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX &&
    317 	    wpa_s->action_tx_wait_time)
    318 		wpa_drv_send_action_cancel_wait(wpa_s);
    319 
    320 	if (wpa_s->off_channel_freq || wpa_s->roc_waiting_drv_freq) {
    321 		wpa_drv_cancel_remain_on_channel(wpa_s);
    322 		wpa_s->off_channel_freq = 0;
    323 		wpa_s->roc_waiting_drv_freq = 0;
    324 	}
    325 }
    326 
    327 
    328 /**
    329  * offchannel_remain_on_channel_cb - Remain-on-channel callback function
    330  * @wpa_s: Pointer to wpa_supplicant data
    331  * @freq: Frequency (in MHz) of the selected channel
    332  * @duration: Duration of the remain-on-channel operation in milliseconds
    333  *
    334  * This function is called whenever the driver notifies beginning of a
    335  * remain-on-channel operation.
    336  */
    337 void offchannel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
    338 				     unsigned int freq, unsigned int duration)
    339 {
    340 	wpa_s->roc_waiting_drv_freq = 0;
    341 	wpa_s->off_channel_freq = freq;
    342 	wpas_send_action_cb(wpa_s, NULL);
    343 }
    344 
    345 
    346 /**
    347  * offchannel_cancel_remain_on_channel_cb - Remain-on-channel stopped callback
    348  * @wpa_s: Pointer to wpa_supplicant data
    349  * @freq: Frequency (in MHz) of the selected channel
    350  *
    351  * This function is called whenever the driver notifies termination of a
    352  * remain-on-channel operation.
    353  */
    354 void offchannel_cancel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
    355 					    unsigned int freq)
    356 {
    357 	wpa_s->off_channel_freq = 0;
    358 }
    359 
    360 
    361 /**
    362  * offchannel_pending_action_tx - Check whether there is a pending Action TX
    363  * @wpa_s: Pointer to wpa_supplicant data
    364  * Returns: Pointer to pending frame or %NULL if no pending operation
    365  *
    366  * This function can be used to check whether there is a pending Action frame TX
    367  * operation. The returned pointer should be used only for checking whether it
    368  * is %NULL (no pending frame) or to print the pointer value in debug
    369  * information (i.e., the pointer should not be dereferenced).
    370  */
    371 const void * offchannel_pending_action_tx(struct wpa_supplicant *wpa_s)
    372 {
    373 	return wpa_s->pending_action_tx;
    374 }
    375 
    376 
    377 /**
    378  * offchannel_clear_pending_action_tx - Clear pending Action frame TX
    379  * @wpa_s: Pointer to wpa_supplicant data
    380  */
    381 void offchannel_clear_pending_action_tx(struct wpa_supplicant *wpa_s)
    382 {
    383 	wpabuf_free(wpa_s->pending_action_tx);
    384 	wpa_s->pending_action_tx = NULL;
    385 }
    386 
    387 
    388 /**
    389  * offchannel_deinit - Deinit off-channel operations
    390  * @wpa_s: Pointer to wpa_supplicant data
    391  *
    392  * This function is used to free up any allocated resources for off-channel
    393  * operations.
    394  */
    395 void offchannel_deinit(struct wpa_supplicant *wpa_s)
    396 {
    397 	offchannel_clear_pending_action_tx(wpa_s);
    398 	eloop_cancel_timeout(wpas_send_action_cb, wpa_s, NULL);
    399 }
    400