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 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 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 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 } 108 109 110 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 } 127 128 129 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 } 135 136 137 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 } 159 160 161 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 } 212 213 214 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 } 286 287 288 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 } 307 308 309 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); 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
