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
21static struct wpa_supplicant *
22wpas_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
50static 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 */
148void 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 */
222int 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 */
338void 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 */
365void 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 */
382void 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 */
399const 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 */
409void 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 */
423void 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