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 72 go = p2p_get_device(p2p, dev->member_in_go_dev); 73 if (go == NULL || dev->oper_freq <= 0) { 74 p2p_dbg(p2p, "Could not find peer entry for GO and frequency to send Device Discoverability Request"); 75 return -1; 76 } 77 78 req = p2p_build_dev_disc_req(p2p, go, dev->info.p2p_device_addr); 79 if (req == NULL) 80 return -1; 81 82 p2p_dbg(p2p, "Sending Device Discoverability Request to GO " MACSTR 83 " for client " MACSTR, 84 MAC2STR(go->info.p2p_device_addr), 85 MAC2STR(dev->info.p2p_device_addr)); 86 87 p2p->pending_client_disc_go = go; 88 os_memcpy(p2p->pending_client_disc_addr, dev->info.p2p_device_addr, 89 ETH_ALEN); 90 p2p->pending_action_state = P2P_PENDING_DEV_DISC_REQUEST; 91 if (p2p_send_action(p2p, dev->oper_freq, go->info.p2p_device_addr, 92 p2p->cfg->dev_addr, go->info.p2p_device_addr, 93 wpabuf_head(req), wpabuf_len(req), 1000) < 0) { 94 p2p_dbg(p2p, "Failed to send Action frame"); 95 wpabuf_free(req); 96 /* TODO: how to recover from failure? */ 97 return -1; 98 } 99 100 wpabuf_free(req); 101 102 return 0; 103 } 104 105 106 static struct wpabuf * p2p_build_dev_disc_resp(u8 dialog_token, u8 status) 107 { 108 struct wpabuf *buf; 109 u8 *len; 110 111 buf = wpabuf_alloc(100); 112 if (buf == NULL) 113 return NULL; 114 115 p2p_buf_add_public_action_hdr(buf, P2P_DEV_DISC_RESP, dialog_token); 116 117 len = p2p_buf_add_ie_hdr(buf); 118 p2p_buf_add_status(buf, status); 119 p2p_buf_update_ie_hdr(buf, len); 120 121 return buf; 122 } 123 124 125 void p2p_dev_disc_resp_cb(struct p2p_data *p2p, int success) 126 { 127 p2p_dbg(p2p, "Device Discoverability Response TX callback: success=%d", 128 success); 129 p2p->cfg->send_action_done(p2p->cfg->cb_ctx); 130 } 131 132 133 static void p2p_send_dev_disc_resp(struct p2p_data *p2p, u8 dialog_token, 134 const u8 *addr, int freq, u8 status) 135 { 136 struct wpabuf *resp; 137 138 resp = p2p_build_dev_disc_resp(dialog_token, status); 139 if (resp == NULL) 140 return; 141 142 p2p_dbg(p2p, "Sending Device Discoverability Response to " MACSTR 143 " (status %u freq %d)", 144 MAC2STR(addr), status, freq); 145 146 p2p->pending_action_state = P2P_PENDING_DEV_DISC_RESPONSE; 147 if (p2p_send_action(p2p, freq, addr, p2p->cfg->dev_addr, 148 p2p->cfg->dev_addr, 149 wpabuf_head(resp), wpabuf_len(resp), 200) < 0) { 150 p2p_dbg(p2p, "Failed to send Action frame"); 151 } 152 153 wpabuf_free(resp); 154 } 155 156 157 void p2p_process_dev_disc_req(struct p2p_data *p2p, const u8 *sa, 158 const u8 *data, size_t len, int rx_freq) 159 { 160 struct p2p_message msg; 161 size_t g; 162 163 p2p_dbg(p2p, "Received Device Discoverability Request from " MACSTR 164 " (freq=%d)", MAC2STR(sa), rx_freq); 165 166 if (p2p_parse(data, len, &msg)) 167 return; 168 169 if (msg.dialog_token == 0) { 170 p2p_dbg(p2p, "Invalid Dialog Token 0 (must be nonzero) in Device Discoverability Request"); 171 p2p_send_dev_disc_resp(p2p, msg.dialog_token, sa, rx_freq, 172 P2P_SC_FAIL_INVALID_PARAMS); 173 p2p_parse_free(&msg); 174 return; 175 } 176 177 if (msg.device_id == NULL) { 178 p2p_dbg(p2p, "P2P Device ID attribute missing from Device Discoverability Request"); 179 p2p_send_dev_disc_resp(p2p, msg.dialog_token, sa, rx_freq, 180 P2P_SC_FAIL_INVALID_PARAMS); 181 p2p_parse_free(&msg); 182 return; 183 } 184 185 for (g = 0; g < p2p->num_groups; g++) { 186 if (p2p_group_go_discover(p2p->groups[g], msg.device_id, sa, 187 rx_freq) == 0) { 188 p2p_dbg(p2p, "Scheduled GO Discoverability Request for the target device"); 189 /* 190 * P2P group code will use a callback to indicate TX 191 * status, so that we can reply to the request once the 192 * target client has acknowledged the request or it has 193 * timed out. 194 */ 195 p2p->pending_dev_disc_dialog_token = msg.dialog_token; 196 os_memcpy(p2p->pending_dev_disc_addr, sa, ETH_ALEN); 197 p2p->pending_dev_disc_freq = rx_freq; 198 p2p_parse_free(&msg); 199 return; 200 } 201 } 202 203 p2p_dbg(p2p, "Requested client was not found in any group or did not support client discoverability"); 204 p2p_send_dev_disc_resp(p2p, msg.dialog_token, sa, rx_freq, 205 P2P_SC_FAIL_UNABLE_TO_ACCOMMODATE); 206 p2p_parse_free(&msg); 207 } 208 209 210 void p2p_process_dev_disc_resp(struct p2p_data *p2p, const u8 *sa, 211 const u8 *data, size_t len) 212 { 213 struct p2p_message msg; 214 struct p2p_device *go; 215 u8 status; 216 217 p2p_dbg(p2p, "Received Device Discoverability Response from " MACSTR, 218 MAC2STR(sa)); 219 220 go = p2p->pending_client_disc_go; 221 if (go == NULL || 222 os_memcmp(sa, go->info.p2p_device_addr, ETH_ALEN) != 0) { 223 p2p_dbg(p2p, "Ignore unexpected Device Discoverability Response"); 224 return; 225 } 226 227 if (p2p_parse(data, len, &msg)) 228 return; 229 230 if (msg.status == NULL) { 231 p2p_parse_free(&msg); 232 return; 233 } 234 235 if (msg.dialog_token != go->dialog_token) { 236 p2p_dbg(p2p, "Ignore Device Discoverability Response with unexpected dialog token %u (expected %u)", 237 msg.dialog_token, go->dialog_token); 238 p2p_parse_free(&msg); 239 return; 240 } 241 242 status = *msg.status; 243 p2p_parse_free(&msg); 244 245 p2p_dbg(p2p, "Device Discoverability Response status %u", status); 246 247 if (p2p->go_neg_peer == NULL || 248 os_memcmp(p2p->pending_client_disc_addr, 249 p2p->go_neg_peer->info.p2p_device_addr, ETH_ALEN) != 0 || 250 os_memcmp(p2p->go_neg_peer->member_in_go_dev, 251 go->info.p2p_device_addr, ETH_ALEN) != 0) { 252 p2p_dbg(p2p, "No pending operation with the client discoverability peer anymore"); 253 return; 254 } 255 256 if (status == 0) { 257 /* 258 * Peer is expected to be awake for at least 100 TU; try to 259 * connect immediately. 260 */ 261 p2p_dbg(p2p, "Client discoverability request succeeded"); 262 if (p2p->state == P2P_CONNECT) { 263 /* 264 * Change state to force the timeout to start in 265 * P2P_CONNECT again without going through the short 266 * Listen state. 267 */ 268 p2p_set_state(p2p, P2P_CONNECT_LISTEN); 269 p2p->cfg->send_action_done(p2p->cfg->cb_ctx); 270 } 271 p2p_set_timeout(p2p, 0, 0); 272 } else { 273 /* 274 * Client discoverability request failed; try to connect from 275 * timeout. 276 */ 277 p2p_dbg(p2p, "Client discoverability request failed"); 278 p2p_set_timeout(p2p, 0, 500000); 279 } 280 281 } 282 283 284 void p2p_go_disc_req_cb(struct p2p_data *p2p, int success) 285 { 286 p2p_dbg(p2p, "GO Discoverability Request TX callback: success=%d", 287 success); 288 p2p->cfg->send_action_done(p2p->cfg->cb_ctx); 289 290 if (p2p->pending_dev_disc_dialog_token == 0) { 291 p2p_dbg(p2p, "No pending Device Discoverability Request"); 292 return; 293 } 294 295 p2p_send_dev_disc_resp(p2p, p2p->pending_dev_disc_dialog_token, 296 p2p->pending_dev_disc_addr, 297 p2p->pending_dev_disc_freq, 298 success ? P2P_SC_SUCCESS : 299 P2P_SC_FAIL_UNABLE_TO_ACCOMMODATE); 300 301 p2p->pending_dev_disc_dialog_token = 0; 302 } 303 304 305 void p2p_process_go_disc_req(struct p2p_data *p2p, const u8 *da, const u8 *sa, 306 const u8 *data, size_t len, int rx_freq) 307 { 308 unsigned int tu; 309 struct wpabuf *ies; 310 311 p2p_dbg(p2p, "Received GO Discoverability Request - remain awake for 100 TU"); 312 313 ies = p2p_build_probe_resp_ies(p2p); 314 if (ies == NULL) 315 return; 316 317 /* Remain awake 100 TU on operating channel */ 318 p2p->pending_client_disc_freq = rx_freq; 319 tu = 100; 320 if (p2p->cfg->start_listen(p2p->cfg->cb_ctx, rx_freq, 1024 * tu / 1000, 321 ies) < 0) { 322 p2p_dbg(p2p, "Failed to start listen mode for client discoverability"); 323 } 324 wpabuf_free(ies); 325 } 326
