1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN 24 * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define BTSTACK_FILE__ "att_dispatch.c" 39 40 41 /** 42 * Dispatcher for independent implementation of ATT client and server 43 */ 44 45 #include "ble/att_dispatch.h" 46 #include "ble/core.h" 47 #include "btstack_debug.h" 48 #include "l2cap.h" 49 #include "btstack_event.h" 50 51 #define ATT_SERVER 0u 52 #define ATT_CLIENT 1u 53 #define ATT_MAX 2u 54 55 struct { 56 btstack_packet_handler_t packet_handler; 57 bool waiting_for_can_send; 58 } subscriptions[ATT_MAX]; 59 60 // index of subscription that will get can send now first if waiting for it 61 static uint8_t att_round_robin; 62 63 // track can send now requests 64 static bool can_send_now_pending; 65 66 #ifdef ENABLE_GATT_OVER_CLASSIC 67 static att_server_t * att_dispatch_att_server_for_l2cap_cid(uint16_t l2cap_cid){ 68 btstack_linked_list_iterator_t it; 69 hci_connections_get_iterator(&it); 70 while(btstack_linked_list_iterator_has_next(&it)) { 71 hci_connection_t *hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 72 att_server_t *att_server = &hci_connection->att_server; 73 if (att_server->l2cap_cid == l2cap_cid){ 74 return att_server; 75 } 76 } 77 return NULL; 78 } 79 #endif 80 81 static void att_dispatch_handle_can_send_now(uint8_t *packet, uint16_t size){ 82 uint8_t i; 83 uint8_t index; 84 uint16_t l2cap_cid = l2cap_event_can_send_now_get_local_cid(packet); 85 #ifdef ENABLE_GATT_OVER_CLASSIC 86 if (l2cap_cid != L2CAP_CID_ATTRIBUTE_PROTOCOL){ 87 att_server_t * att_server = att_dispatch_att_server_for_l2cap_cid(l2cap_cid); 88 if (att_server != NULL){ 89 for (i = 0u; i < ATT_MAX; i++) { 90 index = (att_round_robin + i) & 1u; 91 if (att_server->send_requests[index]) { 92 att_server->send_requests[index] = false; 93 // registered packet handlers from Unenhanced LE 94 subscriptions[index].packet_handler(HCI_EVENT_PACKET, l2cap_cid, packet, size); 95 // fairness: prioritize next service 96 att_round_robin = (index + 1u) % ATT_MAX; 97 // stop if client cannot send anymore 98 if (!l2cap_can_send_packet_now(l2cap_cid)) break; 99 } 100 } 101 // check if more can send now events are needed 102 bool send_request_pending = att_server->send_requests[ATT_CLIENT] 103 || att_server->send_requests[ATT_SERVER]; 104 if (send_request_pending){ 105 l2cap_request_can_send_now_event(att_server->l2cap_cid); 106 } 107 return; 108 } 109 } 110 #endif 111 can_send_now_pending = false; 112 for (i = 0u; i < ATT_MAX; i++){ 113 index = (att_round_robin + i) & 1u; 114 if ( (subscriptions[index].packet_handler != NULL) && subscriptions[index].waiting_for_can_send){ 115 subscriptions[index].waiting_for_can_send = false; 116 subscriptions[index].packet_handler(HCI_EVENT_PACKET, l2cap_cid, packet, size); 117 // fairness: prioritize next service 118 att_round_robin = (index + 1u) % ATT_MAX; 119 // stop if client cannot send anymore 120 if (!hci_can_send_acl_le_packet_now()) break; 121 } 122 } 123 // check if more can send now events are needed 124 if (!can_send_now_pending){ 125 for (i = 0u; i < ATT_MAX; i++){ 126 if ((subscriptions[i].packet_handler != NULL) && subscriptions[i].waiting_for_can_send){ 127 can_send_now_pending = true; 128 // note: con_handle is not used, so we can pass in anything 129 l2cap_request_can_send_fix_channel_now_event(0, L2CAP_CID_ATTRIBUTE_PROTOCOL); 130 break; 131 } 132 } 133 } 134 } 135 136 static void att_dispatch_handle_att_pdu(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 137 uint8_t index; 138 uint8_t opcode; 139 uint8_t method; 140 bool for_server; 141 bool invalid; 142 143 // parse opcode 144 opcode = packet[0u]; 145 method = opcode & 0x03fu; 146 invalid = method > ATT_MULTIPLE_HANDLE_VALUE_NTF; 147 // odd PDUs are sent from server to client - even PDUs are sent from client to server, also let server handle invalid ones 148 for_server = ((method & 1u) == 0u) || invalid; 149 index = for_server ? ATT_SERVER : ATT_CLIENT; 150 if (!subscriptions[index].packet_handler) return; 151 subscriptions[index].packet_handler(packet_type, channel, packet, size); 152 } 153 154 static void att_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 155 #ifdef ENABLE_GATT_OVER_CLASSIC 156 hci_connection_t * hci_connection; 157 att_server_t * att_server; 158 hci_con_handle_t con_handle; 159 bool outgoing_active; 160 uint8_t index; 161 bd_addr_t address; 162 uint16_t l2cap_cid; 163 uint8_t status; 164 #endif 165 switch (packet_type){ 166 case ATT_DATA_PACKET: 167 att_dispatch_handle_att_pdu(packet_type, channel, packet, size); 168 break; 169 #ifdef ENABLE_GATT_OVER_CLASSIC 170 case L2CAP_DATA_PACKET: 171 att_dispatch_handle_att_pdu(packet_type, channel, packet, size); 172 break; 173 #endif 174 case HCI_EVENT_PACKET: 175 switch (hci_event_packet_get_type(packet)) { 176 case L2CAP_EVENT_CAN_SEND_NOW: 177 att_dispatch_handle_can_send_now(packet, size); 178 break; 179 #ifdef ENABLE_GATT_OVER_CLASSIC 180 case L2CAP_EVENT_INCOMING_CONNECTION: 181 l2cap_event_incoming_connection_get_address(packet, address); 182 l2cap_cid = l2cap_event_incoming_connection_get_local_cid(packet); 183 // reject if outgoing l2cap connection active, L2CAP/TIM/BV-01-C 184 con_handle = l2cap_event_incoming_connection_get_handle(packet); 185 hci_connection = hci_connection_for_handle(con_handle); 186 btstack_assert(hci_connection != NULL); 187 outgoing_active = hci_connection->att_server.l2cap_cid != 0; 188 if (outgoing_active) { 189 hci_connection->att_server.incoming_connection_request = true; 190 l2cap_decline_connection(l2cap_cid); 191 log_info("Decline incoming connection from %s", bd_addr_to_str(address)); 192 } else { 193 l2cap_accept_connection(l2cap_cid); 194 log_info("Accept incoming connection from %s", bd_addr_to_str(address)); 195 } 196 break; 197 case L2CAP_EVENT_CHANNEL_OPENED: 198 // store l2cap_cid in att_server 199 status = l2cap_event_channel_opened_get_status(packet); 200 con_handle = l2cap_event_channel_opened_get_handle(packet); 201 hci_connection = hci_connection_for_handle(con_handle); 202 if (status == ERROR_CODE_SUCCESS){ 203 btstack_assert(hci_connection != NULL); 204 hci_connection->att_server.l2cap_cid = l2cap_event_channel_opened_get_local_cid(packet); 205 } else { 206 if (hci_connection != NULL){ 207 hci_connection->att_server.l2cap_cid = 0; 208 } 209 } 210 // dispatch to all roles 211 for (index = 0; index < ATT_MAX; index++){ 212 if (subscriptions[index].packet_handler != NULL){ 213 subscriptions[index].packet_handler(packet_type, channel, packet, size); 214 } 215 } 216 break; 217 case L2CAP_EVENT_CHANNEL_CLOSED: 218 // clear l2cap_cid in att_server 219 l2cap_cid = l2cap_event_channel_closed_get_local_cid(packet); 220 att_server = att_dispatch_att_server_for_l2cap_cid(l2cap_cid); 221 att_server->l2cap_cid = 0; 222 // dispatch to all roles 223 for (index = 0; index < ATT_MAX; index++){ 224 if (subscriptions[index].packet_handler != NULL){ 225 subscriptions[index].packet_handler(packet_type, channel, packet, size); 226 } 227 } 228 break; 229 #endif 230 default: 231 break; 232 } 233 break; 234 default: 235 break; 236 } 237 } 238 239 void att_dispatch_register_client(btstack_packet_handler_t packet_handler){ 240 subscriptions[ATT_CLIENT].packet_handler = packet_handler; 241 l2cap_register_fixed_channel(att_packet_handler, L2CAP_CID_ATTRIBUTE_PROTOCOL); 242 } 243 244 void att_dispatch_register_server(btstack_packet_handler_t packet_handler){ 245 subscriptions[ATT_SERVER].packet_handler = packet_handler; 246 l2cap_register_fixed_channel(att_packet_handler, L2CAP_CID_ATTRIBUTE_PROTOCOL); 247 } 248 249 #ifdef ENABLE_GATT_OVER_CLASSIC 250 static uint16_t att_dispatch_classic_get_l2cap_cid(hci_con_handle_t con_handle){ 251 // get l2cap_cid from att_server in hci_connection 252 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 253 if (hci_connection != NULL) { 254 return hci_connection->att_server.l2cap_cid; 255 } else { 256 return 0; 257 } 258 } 259 #endif 260 261 262 static bool att_dispatch_can_send_now(hci_con_handle_t con_handle) { 263 #ifdef ENABLE_GATT_OVER_CLASSIC 264 uint16_t l2cap_cid = att_dispatch_classic_get_l2cap_cid(con_handle); 265 if (l2cap_cid != 0){ 266 return l2cap_can_send_packet_now(l2cap_cid); 267 } 268 #endif 269 return l2cap_can_send_fixed_channel_packet_now(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL); 270 } 271 272 bool att_dispatch_client_can_send_now(hci_con_handle_t con_handle){ 273 return att_dispatch_can_send_now(con_handle); 274 } 275 276 bool att_dispatch_server_can_send_now(hci_con_handle_t con_handle){ 277 return att_dispatch_can_send_now(con_handle); 278 } 279 280 static void att_dispatch_request_can_send_now_event(hci_con_handle_t con_handle, uint8_t type) { 281 #ifdef ENABLE_GATT_OVER_CLASSIC 282 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 283 if (hci_connection != NULL) { 284 att_server_t * att_server = &hci_connection->att_server; 285 if (att_server->l2cap_cid != 0){ 286 bool send_request_pending = att_server->send_requests[ATT_CLIENT] 287 || att_server->send_requests[ATT_SERVER]; 288 att_server->send_requests[type] = true; 289 if (send_request_pending == false){ 290 l2cap_request_can_send_now_event(att_server->l2cap_cid); 291 } 292 return; 293 } 294 } 295 #endif 296 subscriptions[type].waiting_for_can_send = true; 297 if (can_send_now_pending == false) { 298 can_send_now_pending = true; 299 l2cap_request_can_send_fix_channel_now_event(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL); 300 } 301 } 302 303 void att_dispatch_client_request_can_send_now_event(hci_con_handle_t con_handle){ 304 att_dispatch_request_can_send_now_event(con_handle, ATT_CLIENT); 305 } 306 307 void att_dispatch_server_request_can_send_now_event(hci_con_handle_t con_handle){ 308 att_dispatch_request_can_send_now_event(con_handle, ATT_SERVER); 309 } 310 311 static void emit_mtu_exchange_complete(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, uint16_t new_mtu){ 312 if (!packet_handler) return; 313 uint8_t packet[6]; 314 packet[0] = ATT_EVENT_MTU_EXCHANGE_COMPLETE; 315 packet[1] = sizeof(packet) - 2u; 316 little_endian_store_16(packet, 2, con_handle); 317 little_endian_store_16(packet, 4, new_mtu); 318 packet_handler(HCI_EVENT_PACKET, con_handle, packet, 6); 319 } 320 321 void att_dispatch_server_mtu_exchanged(hci_con_handle_t con_handle, uint16_t new_mtu){ 322 emit_mtu_exchange_complete(subscriptions[ATT_CLIENT].packet_handler, con_handle, new_mtu); 323 } 324 325 void att_dispatch_client_mtu_exchanged(hci_con_handle_t con_handle, uint16_t new_mtu){ 326 emit_mtu_exchange_complete(subscriptions[ATT_SERVER].packet_handler, con_handle, new_mtu); 327 } 328 329 #ifdef ENABLE_GATT_OVER_CLASSIC 330 void att_dispatch_classic_register_service(void){ 331 l2cap_register_service(&att_packet_handler, PSM_ATT, 0xffff, gap_get_security_level()); 332 } 333 uint8_t att_dispatch_classic_connect(bd_addr_t address, uint16_t l2cap_psm, uint16_t *out_cid) { 334 uint16_t l2cap_cid; 335 uint8_t status = l2cap_create_channel(&att_packet_handler, address, l2cap_psm, 0xffff, &l2cap_cid); 336 // store l2cap_cid in hci_connection 337 if (status == ERROR_CODE_SUCCESS){ 338 hci_connection_t * hci_connection = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_ACL); 339 if (hci_connection != NULL) { 340 hci_connection->att_server.l2cap_cid = l2cap_cid; 341 hci_connection->att_server.incoming_connection_request = false; 342 } 343 } 344 *out_cid = l2cap_cid; 345 return status; 346 } 347 348 #endif 349