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 MATTHIAS 24 * RINGWALD 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 /* 39 * l2cap.h 40 * 41 * Logical Link Control and Adaption Protocol (L2CAP) 42 * 43 * Created by Matthias Ringwald on 5/16/09. 44 */ 45 46 #ifndef __L2CAP_H 47 #define __L2CAP_H 48 49 #include "hci.h" 50 #include "l2cap_signaling.h" 51 #include "btstack_util.h" 52 #include "bluetooth.h" 53 54 #if defined __cplusplus 55 extern "C" { 56 #endif 57 58 // check L2CAP MTU 59 #ifdef ENABLE_CLASSIC 60 #if (L2CAP_HEADER_SIZE + L2CAP_MINIMAL_MTU) > HCI_ACL_PAYLOAD_SIZE 61 #error "HCI_ACL_PAYLOAD_SIZE too small for minimal L2CAP MTU of 48 bytes" 62 #endif 63 #endif 64 #ifdef ENABLE_BLE 65 #if (L2CAP_HEADER_SIZE + L2CAP_LE_DEFAULT_MTU) > HCI_ACL_PAYLOAD_SIZE 66 #error "HCI_ACL_PAYLOAD_SIZE too small for minimal L2CAP LE MTU of 23 bytes" 67 #endif 68 #endif 69 70 #define L2CAP_LE_AUTOMATIC_CREDITS 0xffff 71 72 // private structs 73 typedef enum { 74 L2CAP_STATE_CLOSED = 1, // no baseband 75 L2CAP_STATE_WILL_SEND_CREATE_CONNECTION, 76 L2CAP_STATE_WAIT_CONNECTION_COMPLETE, 77 L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES, 78 L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE, 79 L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE, 80 L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT, 81 L2CAP_STATE_WAIT_CONNECT_RSP, // from peer 82 L2CAP_STATE_CONFIG, 83 L2CAP_STATE_OPEN, 84 L2CAP_STATE_WAIT_DISCONNECT, // from application 85 L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST, 86 L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_INSUFFICIENT_SECURITY, 87 L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE, 88 L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT, 89 L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST, 90 L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE, 91 L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST, 92 L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE, 93 L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT, 94 L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE, 95 L2CAP_STATE_INVALID, 96 } L2CAP_STATE; 97 98 typedef enum { 99 L2CAP_CHANNEL_STATE_VAR_NONE = 0, 100 L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ = 1 << 0, 101 L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP = 1 << 1, 102 L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ = 1 << 2, 103 L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP = 1 << 3, 104 L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ = 1 << 4, 105 L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP = 1 << 5, 106 L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU = 1 << 6, // in CONF RSP, add MTU field 107 L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT = 1 << 7, // in CONF RSP, set CONTINUE flag 108 L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID = 1 << 8, // in CONF RSP, send UNKNOWN OPTIONS 109 L2CAP_CHANNEL_STATE_VAR_SEND_CMD_REJ_UNKNOWN = 1 << 9, // send CMD_REJ with reason unknown 110 L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND = 1 << 10, // send Connection Respond with pending 111 L2CAP_CHANNEL_STATE_VAR_INCOMING = 1 << 15, // channel is incoming 112 } L2CAP_CHANNEL_STATE_VAR; 113 114 // info regarding an actual connection 115 typedef struct { 116 // linked list - assert: first field 117 btstack_linked_item_t item; 118 119 // packet handler 120 btstack_packet_handler_t packet_handler; 121 122 // timer 123 btstack_timer_source_t rtx; // also used for ertx 124 125 L2CAP_STATE state; 126 L2CAP_CHANNEL_STATE_VAR state_var; 127 128 // info 129 hci_con_handle_t con_handle; 130 131 bd_addr_t address; 132 bd_addr_type_t address_type; 133 134 uint8_t remote_sig_id; // used by other side, needed for delayed response 135 uint8_t local_sig_id; // own signaling identifier 136 137 uint16_t local_cid; 138 uint16_t remote_cid; 139 140 uint16_t local_mtu; 141 uint16_t remote_mtu; 142 143 uint16_t flush_timeout; // default 0xffff 144 145 uint16_t psm; 146 147 gap_security_level_t required_security_level; 148 149 uint8_t reason; // used in decline internal 150 uint8_t waiting_for_can_send_now; 151 152 // LE Data Channels 153 154 // incoming SDU 155 uint8_t * receive_sdu_buffer; 156 uint16_t receive_sdu_len; 157 uint16_t receive_sdu_pos; 158 159 // outgoing SDU 160 uint8_t * send_sdu_buffer; 161 uint16_t send_sdu_len; 162 uint16_t send_sdu_pos; 163 164 // max PDU size 165 uint16_t remote_mps; 166 167 // credits for outgoing traffic 168 uint16_t credits_outgoing; 169 170 // number of packets remote will be granted 171 uint16_t new_credits_incoming; 172 173 // credits for incoming traffic 174 uint16_t credits_incoming; 175 176 // automatic credits incoming 177 uint16_t automatic_credits; 178 179 } l2cap_channel_t; 180 181 // info regarding potential connections 182 typedef struct { 183 // linked list - assert: first field 184 btstack_linked_item_t item; 185 186 // service id 187 uint16_t psm; 188 189 // incoming MTU 190 uint16_t mtu; 191 192 // internal connection 193 btstack_packet_handler_t packet_handler; 194 195 // required security level 196 gap_security_level_t required_security_level; 197 198 } l2cap_service_t; 199 200 201 typedef struct l2cap_signaling_response { 202 hci_con_handle_t handle; 203 uint8_t sig_id; 204 uint8_t code; 205 uint16_t cid; // source cid for CONNECTION REQUEST 206 uint16_t data; // infoType for INFORMATION REQUEST, result for CONNECTION REQUEST and COMMAND UNKNOWN 207 } l2cap_signaling_response_t; 208 209 210 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id); 211 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id); 212 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id); 213 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len); 214 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len); 215 216 // PTS Testing 217 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len); 218 void l2cap_require_security_level_2_for_outgoing_sdp(void); 219 220 // Used by RFCOMM - similar to l2cap_can-send_packet_now but does not check if outgoing buffer is reserved 221 int l2cap_can_send_prepared_packet_now(uint16_t local_cid); 222 223 /* API_START */ 224 225 /** 226 * @brief Set up L2CAP and register L2CAP with HCI layer. 227 */ 228 void l2cap_init(void); 229 230 /** 231 * @brief Registers packet handler for LE Connection Parameter Update events 232 */ 233 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)); 234 235 /** 236 * @brief Get max MTU for Classic connections based on btstack configuration 237 */ 238 uint16_t l2cap_max_mtu(void); 239 240 /** 241 * @brief Get max MTU for LE connections based on btstack configuration 242 */ 243 uint16_t l2cap_max_le_mtu(void); 244 245 /** 246 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 247 * @param packet_handler 248 * @param address 249 * @param psm 250 * @param mtu 251 * @param local_cid 252 * @return status 253 */ 254 uint8_t l2cap_create_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, uint16_t mtu, uint16_t * out_local_cid); 255 256 /** 257 * @brief Disconnects L2CAP channel with given identifier. 258 */ 259 void l2cap_disconnect(uint16_t local_cid, uint8_t reason); 260 261 /** 262 * @brief Queries the maximal transfer unit (MTU) for L2CAP channel with given identifier. 263 */ 264 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid); 265 266 /** 267 * @brief Sends L2CAP data packet to the channel with given identifier. 268 */ 269 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len); 270 271 /** 272 * @brief Registers L2CAP service with given PSM and MTU, and assigns a packet handler. 273 */ 274 uint8_t l2cap_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level); 275 276 /** 277 * @brief Unregisters L2CAP service with given PSM. On embedded systems, use NULL for connection parameter. 278 */ 279 uint8_t l2cap_unregister_service(uint16_t psm); 280 281 /** 282 * @brief Accepts incoming L2CAP connection. 283 */ 284 void l2cap_accept_connection(uint16_t local_cid); 285 286 /** 287 * @brief Deny incoming L2CAP connection. 288 */ 289 void l2cap_decline_connection(uint16_t local_cid); 290 291 /** 292 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 293 */ 294 int l2cap_can_send_packet_now(uint16_t local_cid); 295 296 /** 297 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 298 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 299 * so packet handler should be ready to handle it 300 * @param local_cid 301 */ 302 void l2cap_request_can_send_now_event(uint16_t local_cid); 303 304 /** 305 * @brief Reserve outgoing buffer 306 */ 307 int l2cap_reserve_packet_buffer(void); 308 309 /** 310 * @brief Get outgoing buffer and prepare data. 311 */ 312 uint8_t *l2cap_get_outgoing_buffer(void); 313 314 /** 315 * @brief Send L2CAP packet prepared in outgoing buffer to channel 316 */ 317 int l2cap_send_prepared(uint16_t local_cid, uint16_t len); 318 319 /** 320 * @brief Release outgoing buffer (only needed if l2cap_send_prepared is not called) 321 */ 322 void l2cap_release_packet_buffer(void); 323 324 325 // 326 // LE Connection Oriented Channels feature with the LE Credit Based Flow Control Mode == LE Data Channel 327 // 328 329 330 /** 331 * @brief Register L2CAP LE Data Channel service 332 * @note MTU and initial credits are specified in l2cap_le_accept_connection(..) call 333 * @param packet_handler 334 * @param psm 335 * @param security_level 336 */ 337 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level); 338 339 /** 340 * @brief Unregister L2CAP LE Data Channel service 341 * @param psm 342 */ 343 344 uint8_t l2cap_le_unregister_service(uint16_t psm); 345 346 /* 347 * @brief Accept incoming LE Data Channel connection 348 * @param local_cid L2CAP LE Data Channel Identifier 349 * @param receive_buffer buffer used for reassembly of L2CAP LE Information Frames into service data unit (SDU) with given MTU 350 * @param receive_buffer_size buffer size equals MTU 351 * @param initial_credits Number of initial credits provided to peer or L2CAP_LE_AUTOMATIC_CREDITS to enable automatic credits 352 */ 353 354 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits); 355 356 /** 357 * @brief Deny incoming LE Data Channel connection due to resource constraints 358 * @param local_cid L2CAP LE Data Channel Identifier 359 */ 360 361 uint8_t l2cap_le_decline_connection(uint16_t local_cid); 362 363 /** 364 * @brief Create LE Data Channel 365 * @param packet_handler Packet handler for this connection 366 * @param con_handle ACL-LE HCI Connction Handle 367 * @param psm Service PSM to connect to 368 * @param receive_buffer buffer used for reassembly of L2CAP LE Information Frames into service data unit (SDU) with given MTU 369 * @param receive_buffer_size buffer size equals MTU 370 * @param initial_credits Number of initial credits provided to peer or L2CAP_LE_AUTOMATIC_CREDITS to enable automatic credits 371 * @param security_level Minimum required security level 372 * @param out_local_cid L2CAP LE Channel Identifier is stored here 373 */ 374 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 375 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 376 uint16_t * out_local_cid); 377 378 /** 379 * @brief Provide credtis for LE Data Channel 380 * @param local_cid L2CAP LE Data Channel Identifier 381 * @param credits Number additional credits for peer 382 */ 383 uint8_t l2cap_le_provide_credits(uint16_t cid, uint16_t credits); 384 385 /** 386 * @brief Check if packet can be scheduled for transmission 387 * @param local_cid L2CAP LE Data Channel Identifier 388 */ 389 int l2cap_le_can_send_now(uint16_t cid); 390 391 /** 392 * @brief Request emission of L2CAP_EVENT_LE_CAN_SEND_NOW as soon as possible 393 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 394 * so packet handler should be ready to handle it 395 * @param local_cid L2CAP LE Data Channel Identifier 396 */ 397 uint8_t l2cap_le_request_can_send_now_event(uint16_t cid); 398 399 /** 400 * @brief Send data via LE Data Channel 401 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 402 * @param local_cid L2CAP LE Data Channel Identifier 403 * @param data data to send 404 * @param size data size 405 */ 406 uint8_t l2cap_le_send_data(uint16_t cid, uint8_t * data, uint16_t size); 407 408 /** 409 * @brief Disconnect from LE Data Channel 410 * @param local_cid L2CAP LE Data Channel Identifier 411 */ 412 uint8_t l2cap_le_disconnect(uint16_t cid); 413 414 /* API_END */ 415 416 #if defined __cplusplus 417 } 418 #endif 419 420 #endif // __L2CAP_H 421