1 /* 2 * Copyright (C) 2009-2012 by Matthias Ringwald 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 MATTHIAS RINGWALD 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 [email protected] 34 * 35 */ 36 37 /* 38 * l2cap.h 39 * 40 * Logical Link Control and Adaption Protocl (L2CAP) 41 * 42 * Created by Matthias Ringwald on 5/16/09. 43 */ 44 45 #pragma once 46 47 #include "hci.h" 48 #include "l2cap_signaling.h" 49 #include <btstack/utils.h> 50 #include <btstack/btstack.h> 51 52 #if defined __cplusplus 53 extern "C" { 54 #endif 55 56 #define L2CAP_SIG_ID_INVALID 0 57 58 #define L2CAP_HEADER_SIZE 4 59 60 // size of HCI ACL + L2CAP Header for regular data packets (8) 61 #define COMPLETE_L2CAP_HEADER (HCI_ACL_HEADER_SIZE + L2CAP_HEADER_SIZE) 62 63 // minimum signaling MTU 64 #define L2CAP_MINIMAL_MTU 48 65 #define L2CAP_DEFAULT_MTU 672 66 67 // check L2CAP MTU 68 #if (L2CAP_MINIMAL_MTU + L2CAP_HEADER_SIZE) > HCI_ACL_PAYLOAD_SIZE 69 #error "HCI_ACL_PAYLOAD_SIZE too small for minimal L2CAP MTU of 48 bytes" 70 #endif 71 72 // L2CAP Fixed Channel IDs 73 #define L2CAP_CID_SIGNALING 0x0001 74 #define L2CAP_CID_CONNECTIONLESS_CHANNEL 0x0002 75 #define L2CAP_CID_ATTRIBUTE_PROTOCOL 0x0004 76 #define L2CAP_CID_SIGNALING_LE 0x0005 77 #define L2CAP_CID_SECURITY_MANAGER_PROTOCOL 0x0006 78 79 // L2CAP Configuration Result Codes 80 #define L2CAP_CONF_RESULT_UNKNOWN_OPTIONS 0x0003 81 82 // L2CAP Reject Result Codes 83 #define L2CAP_REJ_CMD_UNKNOWN 0x0000 84 85 // private structs 86 typedef enum { 87 L2CAP_STATE_CLOSED = 1, // no baseband 88 L2CAP_STATE_WILL_SEND_CREATE_CONNECTION, 89 L2CAP_STATE_WAIT_CONNECTION_COMPLETE, 90 L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT, 91 L2CAP_STATE_WAIT_CONNECT_RSP, // from peer 92 L2CAP_STATE_CONFIG, 93 L2CAP_STATE_OPEN, 94 L2CAP_STATE_WAIT_DISCONNECT, // from application 95 L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST, 96 L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE, 97 L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT, 98 L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST, 99 L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE, 100 } L2CAP_STATE; 101 102 typedef enum { 103 L2CAP_CHANNEL_STATE_VAR_NONE = 0, 104 L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ = 1 << 0, 105 L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP = 1 << 1, 106 L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ = 1 << 2, 107 L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP = 1 << 3, 108 L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ = 1 << 4, 109 L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP = 1 << 5, 110 L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU = 1 << 6, // in CONF RSP, add MTU field 111 L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT = 1 << 7, // in CONF RSP, set CONTINUE flag 112 L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID = 1 << 8, // in CONF RSP, send UNKNOWN OPTIONS 113 L2CAP_CHANNEL_STATE_VAR_SEND_CMD_REJ_UNKNOWN = 1 << 9, // send CMD_REJ with reason unknown 114 } L2CAP_CHANNEL_STATE_VAR; 115 116 // info regarding an actual coneection 117 typedef struct { 118 // linked list - assert: first field 119 linked_item_t item; 120 121 L2CAP_STATE state; 122 L2CAP_CHANNEL_STATE_VAR state_var; 123 124 bd_addr_t address; 125 hci_con_handle_t handle; 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 psm; 137 138 uint8_t packets_granted; // number of L2CAP/ACL packets client is allowed to send 139 140 uint8_t reason; // used in decline internal 141 142 timer_source_t rtx; // also used for ertx 143 144 // client connection 145 void * connection; 146 147 // internal connection 148 btstack_packet_handler_t packet_handler; 149 150 } l2cap_channel_t; 151 152 // info regarding potential connections 153 typedef struct { 154 // linked list - assert: first field 155 linked_item_t item; 156 157 // service id 158 uint16_t psm; 159 160 // incoming MTU 161 uint16_t mtu; 162 163 // client connection 164 void *connection; 165 166 // internal connection 167 btstack_packet_handler_t packet_handler; 168 169 } l2cap_service_t; 170 171 172 typedef struct l2cap_signaling_response { 173 hci_con_handle_t handle; 174 uint8_t sig_id; 175 uint8_t code; 176 uint16_t data; // infoType for INFORMATION REQUEST, result for CONNECTION request and command unknown 177 } l2cap_signaling_response_t; 178 179 180 void l2cap_block_new_credits(uint8_t blocked); 181 int l2cap_can_send_packet_now(uint16_t local_cid); // non-blocking UART write 182 183 // get outgoing buffer and prepare data 184 uint8_t *l2cap_get_outgoing_buffer(void); 185 186 int l2cap_send_prepared(uint16_t local_cid, uint16_t len); 187 188 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len); 189 190 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 191 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id); 192 193 uint16_t l2cap_max_mtu(void); 194 195 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len); 196 197 void l2cap_close_connection(void *connection); 198 199 200 /** Embedded API **/ 201 202 // Set up L2CAP and register L2CAP with HCI layer. 203 void l2cap_init(void); 204 205 // Registers a packet handler that handles HCI and general BTstack events. 206 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)); 207 208 // Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 209 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, uint16_t mtu); 210 211 // Disconencts L2CAP channel with given identifier. 212 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason); 213 214 // Queries the maximal transfer unit (MTU) for L2CAP channel with given identifier. 215 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid); 216 217 // Sends L2CAP data packet to the channel with given identifier. 218 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len); 219 220 // Registers L2CAP service with given PSM and MTU, and assigns a packet handler. On embedded systems, use NULL for connection parameter. 221 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu); 222 223 // Unregisters L2CAP service with given PSM. On embedded systems, use NULL for connection parameter. 224 void l2cap_unregister_service_internal(void *connection, uint16_t psm); 225 226 // Accepts/Deny incoming L2CAP connection. 227 void l2cap_accept_connection_internal(uint16_t local_cid); 228 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason); 229 230 231 #if defined __cplusplus 232 } 233 #endif 234