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