1 /*
2 * Wi-Fi Direct - P2P Device Discoverability procedure
3 * Copyright (c) 2010, Atheros Communications
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #include "includes.h"
10
11 #include "common.h"
12 #include "common/ieee802_11_defs.h"
13 #include "p2p_i.h"
14 #include "p2p.h"
15
16
p2p_build_dev_disc_req(struct p2p_data * p2p,struct p2p_device * go,const u8 * dev_id)17 static struct wpabuf * p2p_build_dev_disc_req(struct p2p_data *p2p,
18 struct p2p_device *go,
19 const u8 *dev_id)
20 {
21 struct wpabuf *buf;
22 u8 *len;
23
24 buf = wpabuf_alloc(100);
25 if (buf == NULL)
26 return NULL;
27
28 go->dialog_token++;
29 if (go->dialog_token == 0)
30 go->dialog_token = 1;
31 p2p_buf_add_public_action_hdr(buf, P2P_DEV_DISC_REQ, go->dialog_token);
32
33 len = p2p_buf_add_ie_hdr(buf);
34 p2p_buf_add_device_id(buf, dev_id);
35 p2p_buf_add_group_id(buf, go->info.p2p_device_addr, go->oper_ssid,
36 go->oper_ssid_len);
37 p2p_buf_update_ie_hdr(buf, len);
38
39 return buf;
40 }
41
42
p2p_dev_disc_req_cb(struct p2p_data * p2p,int success)43 void p2p_dev_disc_req_cb(struct p2p_data *p2p, int success)
44 {
45 p2p_dbg(p2p, "Device Discoverability Request TX callback: success=%d",
46 success);
47
48 if (!success) {
49 /*
50 * Use P2P find, if needed, to find the other device or to
51 * retry device discoverability.
52 */
53 p2p_set_state(p2p, P2P_CONNECT);
54 p2p_set_timeout(p2p, 0, 100000);
55 return;
56 }
57
58 p2p_dbg(p2p, "GO acknowledged Device Discoverability Request - wait for response");
59 /*
60 * TODO: is the remain-on-channel from Action frame TX long enough for
61 * most cases or should we try to increase its duration and/or start
62 * another remain-on-channel if needed once the previous one expires?
63 */
64 }
65
66
p2p_send_dev_disc_req(struct p2p_data * p2p,struct p2p_device * dev)67 int p2p_send_dev_disc_req(struct p2p_data *p2p, struct p2p_device *dev)
68 {
69 struct p2p_device *go;
70 struct wpabuf *req;
71 unsigned int wait_time;
72
73 go = p2p_get_device(p2p, dev->member_in_go_dev);
74 if (go == NULL || dev->oper_freq <= 0) {
75 p2p_dbg(p2p, "Could not find peer entry for GO and frequency to send Device Discoverability Request");
76 return -1;
77 }
78
79 req = p2p_build_dev_disc_req(p2p, go, dev->info.p2p_device_addr);
80 if (req == NULL)
81 return -1;
82
83 p2p_dbg(p2p, "Sending Device Discoverability Request to GO " MACSTR
84 " for client " MACSTR,
85 MAC2STR(go->info.p2p_device_addr),
86 MAC2STR(dev->info.p2p_device_addr));
87
88 p2p->pending_client_disc_go = go;
89 os_memcpy(p2p->pending_client_disc_addr, dev->info.p2p_device_addr,
90 ETH_ALEN);
91 p2p->pending_action_state = P2P_PENDING_DEV_DISC_REQUEST;
92 wait_time = 1000;
93 if (p2p->cfg->max_listen && wait_time > p2p->cfg->max_listen)
94 wait_time = p2p->cfg->max_listen;
95 if (p2p_send_action(p2p, dev->oper_freq, go->info.p2p_device_addr,
96 p2p->cfg->dev_addr, go->info.p2p_device_addr,
97 wpabuf_head(req), wpabuf_len(req), wait_time) < 0) {
98 p2p_dbg(p2p, "Failed to send Action frame");
99 wpabuf_free(req);
100 /* TODO: how to recover from failure? */
101 return -1;
102 }
103
104 wpabuf_free(req);
105
106 return 0;
107 }
108
109
p2p_build_dev_disc_resp(u8 dialog_token,u8 status)110 static struct wpabuf * p2p_build_dev_disc_resp(u8 dialog_token, u8 status)
111 {
112 struct wpabuf *buf;
113 u8 *len;
114
115 buf = wpabuf_alloc(100);
116 if (buf == NULL)
117 return NULL;
118
119 p2p_buf_add_public_action_hdr(buf, P2P_DEV_DISC_RESP, dialog_token);
120
121 len = p2p_buf_add_ie_hdr(buf);
122 p2p_buf_add_status(buf, status);
123 p2p_buf_update_ie_hdr(buf, len);
124
125 return buf;
126 }
127
128
p2p_dev_disc_resp_cb(struct p2p_data * p2p,int success)129 void p2p_dev_disc_resp_cb(struct p2p_data *p2p, int success)
130 {
131 p2p_dbg(p2p, "Device Discoverability Response TX callback: success=%d",
132 success);
133 p2p->cfg->send_action_done(p2p->cfg->cb_ctx);
134 }
135
136
p2p_send_dev_disc_resp(struct p2p_data * p2p,u8 dialog_token,const u8 * addr,int freq,u8 status)137 static void p2p_send_dev_disc_resp(struct p2p_data *p2p, u8 dialog_token,
138 const u8 *addr, int freq, u8 status)
139 {
140 struct wpabuf *resp;
141
142 resp = p2p_build_dev_disc_resp(dialog_token, status);
143 if (resp == NULL)
144 return;
145
146 p2p_dbg(p2p, "Sending Device Discoverability Response to " MACSTR
147 " (status %u freq %d)",
148 MAC2STR(addr), status, freq);
149
150 p2p->pending_action_state = P2P_PENDING_DEV_DISC_RESPONSE;
151 if (p2p_send_action(p2p, freq, addr, p2p->cfg->dev_addr,
152 p2p->cfg->dev_addr,
153 wpabuf_head(resp), wpabuf_len(resp), 200) < 0) {
154 p2p_dbg(p2p, "Failed to send Action frame");
155 }
156
157 wpabuf_free(resp);
158 }
159
160
p2p_process_dev_disc_req(struct p2p_data * p2p,const u8 * sa,const u8 * data,size_t len,int rx_freq)161 void p2p_process_dev_disc_req(struct p2p_data *p2p, const u8 *sa,
162 const u8 *data, size_t len, int rx_freq)
163 {
164 struct p2p_message msg;
165 size_t g;
166
167 p2p_dbg(p2p, "Received Device Discoverability Request from " MACSTR
168 " (freq=%d)", MAC2STR(sa), rx_freq);
169
170 if (p2p_parse(data, len, &msg))
171 return;
172
173 if (msg.dialog_token == 0) {
174 p2p_dbg(p2p, "Invalid Dialog Token 0 (must be nonzero) in Device Discoverability Request");
175 p2p_send_dev_disc_resp(p2p, msg.dialog_token, sa, rx_freq,
176 P2P_SC_FAIL_INVALID_PARAMS);
177 p2p_parse_free(&msg);
178 return;
179 }
180
181 if (msg.device_id == NULL) {
182 p2p_dbg(p2p, "P2P Device ID attribute missing from Device Discoverability Request");
183 p2p_send_dev_disc_resp(p2p, msg.dialog_token, sa, rx_freq,
184 P2P_SC_FAIL_INVALID_PARAMS);
185 p2p_parse_free(&msg);
186 return;
187 }
188
189 for (g = 0; g < p2p->num_groups; g++) {
190 if (p2p_group_go_discover(p2p->groups[g], msg.device_id, sa,
191 rx_freq) == 0) {
192 p2p_dbg(p2p, "Scheduled GO Discoverability Request for the target device");
193 /*
194 * P2P group code will use a callback to indicate TX
195 * status, so that we can reply to the request once the
196 * target client has acknowledged the request or it has
197 * timed out.
198 */
199 p2p->pending_dev_disc_dialog_token = msg.dialog_token;
200 os_memcpy(p2p->pending_dev_disc_addr, sa, ETH_ALEN);
201 p2p->pending_dev_disc_freq = rx_freq;
202 p2p_parse_free(&msg);
203 return;
204 }
205 }
206
207 p2p_dbg(p2p, "Requested client was not found in any group or did not support client discoverability");
208 p2p_send_dev_disc_resp(p2p, msg.dialog_token, sa, rx_freq,
209 P2P_SC_FAIL_UNABLE_TO_ACCOMMODATE);
210 p2p_parse_free(&msg);
211 }
212
213
p2p_process_dev_disc_resp(struct p2p_data * p2p,const u8 * sa,const u8 * data,size_t len)214 void p2p_process_dev_disc_resp(struct p2p_data *p2p, const u8 *sa,
215 const u8 *data, size_t len)
216 {
217 struct p2p_message msg;
218 struct p2p_device *go;
219 u8 status;
220
221 p2p_dbg(p2p, "Received Device Discoverability Response from " MACSTR,
222 MAC2STR(sa));
223
224 go = p2p->pending_client_disc_go;
225 if (go == NULL ||
226 os_memcmp(sa, go->info.p2p_device_addr, ETH_ALEN) != 0) {
227 p2p_dbg(p2p, "Ignore unexpected Device Discoverability Response");
228 return;
229 }
230
231 if (p2p_parse(data, len, &msg))
232 return;
233
234 if (msg.status == NULL) {
235 p2p_parse_free(&msg);
236 return;
237 }
238
239 if (msg.dialog_token != go->dialog_token) {
240 p2p_dbg(p2p, "Ignore Device Discoverability Response with unexpected dialog token %u (expected %u)",
241 msg.dialog_token, go->dialog_token);
242 p2p_parse_free(&msg);
243 return;
244 }
245
246 status = *msg.status;
247 p2p_parse_free(&msg);
248
249 p2p_dbg(p2p, "Device Discoverability Response status %u", status);
250
251 if (p2p->go_neg_peer == NULL ||
252 os_memcmp(p2p->pending_client_disc_addr,
253 p2p->go_neg_peer->info.p2p_device_addr, ETH_ALEN) != 0 ||
254 os_memcmp(p2p->go_neg_peer->member_in_go_dev,
255 go->info.p2p_device_addr, ETH_ALEN) != 0) {
256 p2p_dbg(p2p, "No pending operation with the client discoverability peer anymore");
257 return;
258 }
259
260 if (status == 0) {
261 /*
262 * Peer is expected to be awake for at least 100 TU; try to
263 * connect immediately.
264 */
265 p2p_dbg(p2p, "Client discoverability request succeeded");
266 if (p2p->state == P2P_CONNECT) {
267 /*
268 * Change state to force the timeout to start in
269 * P2P_CONNECT again without going through the short
270 * Listen state.
271 */
272 p2p_set_state(p2p, P2P_CONNECT_LISTEN);
273 p2p->cfg->send_action_done(p2p->cfg->cb_ctx);
274 }
275 p2p_set_timeout(p2p, 0, 0);
276 } else {
277 /*
278 * Client discoverability request failed; try to connect from
279 * timeout.
280 */
281 p2p_dbg(p2p, "Client discoverability request failed");
282 p2p_set_timeout(p2p, 0, 500000);
283 }
284
285 }
286
287
p2p_go_disc_req_cb(struct p2p_data * p2p,int success)288 void p2p_go_disc_req_cb(struct p2p_data *p2p, int success)
289 {
290 p2p_dbg(p2p, "GO Discoverability Request TX callback: success=%d",
291 success);
292 p2p->cfg->send_action_done(p2p->cfg->cb_ctx);
293
294 if (p2p->pending_dev_disc_dialog_token == 0) {
295 p2p_dbg(p2p, "No pending Device Discoverability Request");
296 return;
297 }
298
299 p2p_send_dev_disc_resp(p2p, p2p->pending_dev_disc_dialog_token,
300 p2p->pending_dev_disc_addr,
301 p2p->pending_dev_disc_freq,
302 success ? P2P_SC_SUCCESS :
303 P2P_SC_FAIL_UNABLE_TO_ACCOMMODATE);
304
305 p2p->pending_dev_disc_dialog_token = 0;
306 }
307
308
p2p_process_go_disc_req(struct p2p_data * p2p,const u8 * da,const u8 * sa,const u8 * data,size_t len,int rx_freq)309 void p2p_process_go_disc_req(struct p2p_data *p2p, const u8 *da, const u8 *sa,
310 const u8 *data, size_t len, int rx_freq)
311 {
312 unsigned int tu;
313 struct wpabuf *ies;
314
315 p2p_dbg(p2p, "Received GO Discoverability Request - remain awake for 100 TU");
316
317 ies = p2p_build_probe_resp_ies(p2p, NULL, 0);
318 if (ies == NULL)
319 return;
320
321 /* Remain awake 100 TU on operating channel */
322 p2p->pending_client_disc_freq = rx_freq;
323 tu = 100;
324 if (p2p->cfg->start_listen(p2p->cfg->cb_ctx, rx_freq, 1024 * tu / 1000,
325 ies) < 0) {
326 p2p_dbg(p2p, "Failed to start listen mode for client discoverability");
327 }
328 wpabuf_free(ies);
329 }
330