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