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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 "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 		if (wait_time)
    314 			wpa_s->action_tx_wait_time_used = 1;
    315 
    316 		ret = wpa_drv_send_action(
    317 			iface, wpa_s->pending_action_freq,
    318 			wait_time, wpa_s->pending_action_dst,
    319 			wpa_s->pending_action_src, wpa_s->pending_action_bssid,
    320 			wpabuf_head(wpa_s->pending_action_tx),
    321 			wpabuf_len(wpa_s->pending_action_tx),
    322 			wpa_s->pending_action_no_cck);
    323 		if (ret == 0)
    324 			wpa_s->pending_action_tx_done = 1;
    325 		return ret;
    326 	}
    327 
    328 	if (freq) {
    329 		struct wpa_supplicant *tx_iface;
    330 		tx_iface = wpas_get_tx_interface(wpa_s, src);
    331 		if (tx_iface->assoc_freq == freq) {
    332 			wpa_printf(MSG_DEBUG, "Off-channel: Already on "
    333 				   "requested channel (TX interface operating "
    334 				   "channel)");
    335 			freq = 0;
    336 		}
    337 	}
    338 
    339 	if (wpa_s->off_channel_freq == freq || freq == 0) {
    340 		wpa_printf(MSG_DEBUG, "Off-channel: Already on requested "
    341 			   "channel; send Action frame immediately");
    342 		/* TODO: Would there ever be need to extend the current
    343 		 * duration on the channel? */
    344 		wpa_s->pending_action_without_roc = 1;
    345 		eloop_cancel_timeout(wpas_send_action_cb, wpa_s, NULL);
    346 		eloop_register_timeout(0, 0, wpas_send_action_cb, wpa_s, NULL);
    347 		return 0;
    348 	}
    349 	wpa_s->pending_action_without_roc = 0;
    350 
    351 	if (wpa_s->roc_waiting_drv_freq == freq) {
    352 		wpa_printf(MSG_DEBUG, "Off-channel: Already waiting for "
    353 			   "driver to get to frequency %u MHz; continue "
    354 			   "waiting to send the Action frame", freq);
    355 		return 0;
    356 	}
    357 
    358 	wpa_printf(MSG_DEBUG, "Off-channel: Schedule Action frame to be "
    359 		   "transmitted once the driver gets to the requested "
    360 		   "channel");
    361 	if (wait_time > wpa_s->max_remain_on_chan)
    362 		wait_time = wpa_s->max_remain_on_chan;
    363 	else if (wait_time == 0)
    364 		wait_time = 20;
    365 #ifdef CONFIG_TESTING_OPTIONS
    366 	if (wpa_s->extra_roc_dur) {
    367 		wpa_printf(MSG_DEBUG, "TESTING: Increase ROC duration %u -> %u",
    368 			   wait_time, wait_time + wpa_s->extra_roc_dur);
    369 		wait_time += wpa_s->extra_roc_dur;
    370 	}
    371 #endif /* CONFIG_TESTING_OPTIONS */
    372 	if (wpa_drv_remain_on_channel(wpa_s, freq, wait_time) < 0) {
    373 		wpa_printf(MSG_DEBUG, "Off-channel: Failed to request driver "
    374 			   "to remain on channel (%u MHz) for Action "
    375 			   "Frame TX", freq);
    376 		return -1;
    377 	}
    378 	wpa_s->off_channel_freq = 0;
    379 	wpa_s->roc_waiting_drv_freq = freq;
    380 
    381 	return 0;
    382 }
    383 
    384 
    385 /**
    386  * offchannel_send_send_action_done - Notify completion of Action frame sequence
    387  * @wpa_s: Pointer to wpa_supplicant data
    388  *
    389  * This function can be used to cancel a wait for additional response frames on
    390  * the channel that was used with offchannel_send_action().
    391  */
    392 void offchannel_send_action_done(struct wpa_supplicant *wpa_s)
    393 {
    394 	wpa_printf(MSG_DEBUG,
    395 		   "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",
    396 		   wpa_s->pending_action_tx,
    397 		   !!(wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX),
    398 		   wpa_s->action_tx_wait_time, wpa_s->off_channel_freq,
    399 		   wpa_s->roc_waiting_drv_freq);
    400 	wpabuf_free(wpa_s->pending_action_tx);
    401 	wpa_s->pending_action_tx = NULL;
    402 	if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX &&
    403 	    (wpa_s->action_tx_wait_time || wpa_s->action_tx_wait_time_used))
    404 		wpa_drv_send_action_cancel_wait(wpa_s);
    405 	else if (wpa_s->off_channel_freq || wpa_s->roc_waiting_drv_freq) {
    406 		wpa_drv_cancel_remain_on_channel(wpa_s);
    407 		wpa_s->off_channel_freq = 0;
    408 		wpa_s->roc_waiting_drv_freq = 0;
    409 	}
    410 	wpa_s->action_tx_wait_time_used = 0;
    411 }
    412 
    413 
    414 /**
    415  * offchannel_remain_on_channel_cb - Remain-on-channel callback function
    416  * @wpa_s: Pointer to wpa_supplicant data
    417  * @freq: Frequency (in MHz) of the selected channel
    418  * @duration: Duration of the remain-on-channel operation in milliseconds
    419  *
    420  * This function is called whenever the driver notifies beginning of a
    421  * remain-on-channel operation.
    422  */
    423 void offchannel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
    424 				     unsigned int freq, unsigned int duration)
    425 {
    426 	wpa_s->roc_waiting_drv_freq = 0;
    427 	wpa_s->off_channel_freq = freq;
    428 	wpas_send_action_cb(wpa_s, NULL);
    429 }
    430 
    431 
    432 /**
    433  * offchannel_cancel_remain_on_channel_cb - Remain-on-channel stopped callback
    434  * @wpa_s: Pointer to wpa_supplicant data
    435  * @freq: Frequency (in MHz) of the selected channel
    436  *
    437  * This function is called whenever the driver notifies termination of a
    438  * remain-on-channel operation.
    439  */
    440 void offchannel_cancel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
    441 					    unsigned int freq)
    442 {
    443 	wpa_s->off_channel_freq = 0;
    444 }
    445 
    446 
    447 /**
    448  * offchannel_pending_action_tx - Check whether there is a pending Action TX
    449  * @wpa_s: Pointer to wpa_supplicant data
    450  * Returns: Pointer to pending frame or %NULL if no pending operation
    451  *
    452  * This function can be used to check whether there is a pending Action frame TX
    453  * operation. The returned pointer should be used only for checking whether it
    454  * is %NULL (no pending frame) or to print the pointer value in debug
    455  * information (i.e., the pointer should not be dereferenced).
    456  */
    457 const void * offchannel_pending_action_tx(struct wpa_supplicant *wpa_s)
    458 {
    459 	return wpa_s->pending_action_tx;
    460 }
    461 
    462 
    463 /**
    464  * offchannel_clear_pending_action_tx - Clear pending Action frame TX
    465  * @wpa_s: Pointer to wpa_supplicant data
    466  */
    467 void offchannel_clear_pending_action_tx(struct wpa_supplicant *wpa_s)
    468 {
    469 	wpa_printf(MSG_DEBUG,
    470 		   "Off-channel: Clear pending Action frame TX (pending_action_tx=%p",
    471 		   wpa_s->pending_action_tx);
    472 	wpabuf_free(wpa_s->pending_action_tx);
    473 	wpa_s->pending_action_tx = NULL;
    474 }
    475 
    476 
    477 /**
    478  * offchannel_deinit - Deinit off-channel operations
    479  * @wpa_s: Pointer to wpa_supplicant data
    480  *
    481  * This function is used to free up any allocated resources for off-channel
    482  * operations.
    483  */
    484 void offchannel_deinit(struct wpa_supplicant *wpa_s)
    485 {
    486 	offchannel_clear_pending_action_tx(wpa_s);
    487 	eloop_cancel_timeout(wpas_send_action_cb, wpa_s, NULL);
    488 }
    489