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 data; // infoType for INFORMATION REQUEST, result for CONNECTION request and command unknown 199 } l2cap_signaling_response_t; 200 201 202 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id); 203 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id); 204 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id); 205 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len); 206 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len); 207 208 // PTS Testing 209 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len); 210 void l2cap_require_security_level_2_for_outgoing_sdp(void); 211 212 // Used by RFCOMM - similar to l2cap_can-send_packet_now but does not check if outgoing buffer is reserved 213 int l2cap_can_send_prepared_packet_now(uint16_t local_cid); 214 215 /* API_START */ 216 217 /** 218 * @brief Set up L2CAP and register L2CAP with HCI layer. 219 */ 220 void l2cap_init(void); 221 222 /** 223 * @brief Registers packet handler for LE Connection Parameter Update events 224 */ 225 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)); 226 227 /** 228 * @brief Get max MTU for Classic connections based on btstack configuration 229 */ 230 uint16_t l2cap_max_mtu(void); 231 232 /** 233 * @brief Get max MTU for LE connections based on btstack configuration 234 */ 235 uint16_t l2cap_max_le_mtu(void); 236 237 /** 238 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 239 * @param packet_handler 240 * @param address 241 * @param psm 242 * @param mtu 243 * @param local_cid 244 * @param status 245 */ 246 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); 247 248 /** 249 * @brief Disconnects L2CAP channel with given identifier. 250 */ 251 void l2cap_disconnect(uint16_t local_cid, uint8_t reason); 252 253 /** 254 * @brief Queries the maximal transfer unit (MTU) for L2CAP channel with given identifier. 255 */ 256 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid); 257 258 /** 259 * @brief Sends L2CAP data packet to the channel with given identifier. 260 */ 261 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len); 262 263 /** 264 * @brief Registers L2CAP service with given PSM and MTU, and assigns a packet handler. 265 */ 266 uint8_t l2cap_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level); 267 268 /** 269 * @brief Unregisters L2CAP service with given PSM. On embedded systems, use NULL for connection parameter. 270 */ 271 uint8_t l2cap_unregister_service(uint16_t psm); 272 273 /** 274 * @brief Accepts incoming L2CAP connection. 275 */ 276 void l2cap_accept_connection(uint16_t local_cid); 277 278 /** 279 * @brief Deny incoming L2CAP connection. 280 */ 281 void l2cap_decline_connection(uint16_t local_cid); 282 283 /** 284 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 285 */ 286 int l2cap_can_send_packet_now(uint16_t local_cid); 287 288 /** 289 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 290 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 291 * so packet handler should be ready to handle it 292 * @param local_cid 293 */ 294 void l2cap_request_can_send_now_event(uint16_t local_cid); 295 296 /** 297 * @brief Reserve outgoing buffer 298 */ 299 int l2cap_reserve_packet_buffer(void); 300 301 /** 302 * @brief Get outgoing buffer and prepare data. 303 */ 304 uint8_t *l2cap_get_outgoing_buffer(void); 305 306 /** 307 * @brief Send L2CAP packet prepared in outgoing buffer to channel 308 */ 309 int l2cap_send_prepared(uint16_t local_cid, uint16_t len); 310 311 /** 312 * @brief Release outgoing buffer (only needed if l2cap_send_prepared is not called) 313 */ 314 void l2cap_release_packet_buffer(void); 315 316 317 // 318 // LE Connection Oriented Channels feature with the LE Credit Based Flow Control Mode == LE Data Channel 319 // 320 321 322 /** 323 * @brief Register L2CAP LE Data Channel service 324 * @note MTU and initial credits are specified in l2cap_le_accept_connection(..) call 325 * @param packet_handler 326 * @param psm 327 * @param security_level 328 */ 329 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level); 330 331 /** 332 * @brief Unregister L2CAP LE Data Channel service 333 * @param psm 334 */ 335 336 uint8_t l2cap_le_unregister_service(uint16_t psm); 337 338 /* 339 * @brief Accept incoming LE Data Channel connection 340 * @param local_cid L2CAP LE Data Channel Identifier 341 * @param receive_buffer buffer used for reassembly of L2CAP LE Information Frames into service data unit (SDU) with given MTU 342 * @param receive_buffer_size buffer size equals MTU 343 * @param initial_credits Number of initial credits provided to peer or L2CAP_LE_AUTOMATIC_CREDITS to enable automatic credits 344 */ 345 346 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits); 347 348 /** 349 * @brief Deny incoming LE Data Channel connection due to resource constraints 350 * @param local_cid L2CAP LE Data Channel Identifier 351 */ 352 353 uint8_t l2cap_le_decline_connection(uint16_t local_cid); 354 355 /** 356 * @brief Create LE Data Channel 357 * @param packet_handler Packet handler for this connection 358 * @param con_handle ACL-LE HCI Connction Handle 359 * @param psm Service PSM to connect to 360 * @param receive_buffer buffer used for reassembly of L2CAP LE Information Frames into service data unit (SDU) with given MTU 361 * @param receive_buffer_size buffer size equals MTU 362 * @param initial_credits Number of initial credits provided to peer or L2CAP_LE_AUTOMATIC_CREDITS to enable automatic credits 363 * @param security_level Minimum required security level 364 * @param out_local_cid L2CAP LE Channel Identifier is stored here 365 */ 366 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 367 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 368 uint16_t * out_local_cid); 369 370 /** 371 * @brief Provide credtis for LE Data Channel 372 * @param local_cid L2CAP LE Data Channel Identifier 373 * @param credits Number additional credits for peer 374 */ 375 uint8_t l2cap_le_provide_credits(uint16_t cid, uint16_t credits); 376 377 /** 378 * @brief Check if packet can be scheduled for transmission 379 * @param local_cid L2CAP LE Data Channel Identifier 380 */ 381 int l2cap_le_can_send_now(uint16_t cid); 382 383 /** 384 * @brief Request emission of L2CAP_EVENT_LE_CAN_SEND_NOW as soon as possible 385 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 386 * so packet handler should be ready to handle it 387 * @param local_cid L2CAP LE Data Channel Identifier 388 */ 389 uint8_t l2cap_le_request_can_send_now_event(uint16_t cid); 390 391 /** 392 * @brief Send data via LE Data Channel 393 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 394 * @param local_cid L2CAP LE Data Channel Identifier 395 * @param data data to send 396 * @param size data size 397 */ 398 uint8_t l2cap_le_send_data(uint16_t cid, uint8_t * data, uint16_t size); 399 400 /** 401 * @brief Disconnect from LE Data Channel 402 * @param local_cid L2CAP LE Data Channel Identifier 403 */ 404 uint8_t l2cap_le_disconnect(uint16_t cid); 405 406 /* API_END */ 407 408 #if defined __cplusplus 409 } 410 #endif 411 412 #endif // __L2CAP_H 413