l2cap.h

00001 /*
00002  * Copyright (C) 2009-2012 by Matthias Ringwald
00003  *
00004  * Redistribution and use in source and binary forms, with or without
00005  * modification, are permitted provided that the following conditions
00006  * are met:
00007  *
00008  * 1. Redistributions of source code must retain the above copyright
00009  *    notice, this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright
00011  *    notice, this list of conditions and the following disclaimer in the
00012  *    documentation and/or other materials provided with the distribution.
00013  * 3. Neither the name of the copyright holders nor the names of
00014  *    contributors may be used to endorse or promote products derived
00015  *    from this software without specific prior written permission.
00016  * 4. Any redistribution, use, or modification is done solely for
00017  *    personal benefit and not for any commercial purpose or for
00018  *    monetary gain.
00019  *
00020  * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS
00021  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00022  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00023  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
00024  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00025  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00026  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
00027  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
00028  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
00029  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
00030  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00031  * SUCH DAMAGE.
00032  *
00033  * Please inquire about commercial licensing options at btstack@ringwald.ch
00034  *
00035  */
00036 
00037 /*
00038  *  l2cap.h
00039  *
00040  *  Logical Link Control and Adaption Protocl (L2CAP)
00041  *
00042  *  Created by Matthias Ringwald on 5/16/09.
00043  */
00044 
00045 #pragma once
00046 
00047 #include "hci.h"
00048 #include "l2cap_signaling.h"
00049 #include <btstack/utils.h>
00050 #include <btstack/btstack.h>
00051 
00052 #if defined __cplusplus
00053 extern "C" {
00054 #endif
00055     
00056 #define L2CAP_SIG_ID_INVALID 0
00057 
00058 #define L2CAP_HEADER_SIZE 4
00059 
00060 // size of HCI ACL + L2CAP Header for regular data packets (8)
00061 #define COMPLETE_L2CAP_HEADER (HCI_ACL_HEADER_SIZE + L2CAP_HEADER_SIZE)
00062     
00063 // minimum signaling MTU
00064 #define L2CAP_MINIMAL_MTU 48
00065 #define L2CAP_DEFAULT_MTU 672
00066     
00067 // check L2CAP MTU
00068 #if (L2CAP_MINIMAL_MTU + L2CAP_HEADER_SIZE) > HCI_ACL_PAYLOAD_SIZE
00069 #error "HCI_ACL_PAYLOAD_SIZE too small for minimal L2CAP MTU of 48 bytes"
00070 #endif    
00071     
00072 // L2CAP Fixed Channel IDs    
00073 #define L2CAP_CID_SIGNALING                 0x0001
00074 #define L2CAP_CID_CONNECTIONLESS_CHANNEL    0x0002
00075 #define L2CAP_CID_ATTRIBUTE_PROTOCOL        0x0004
00076 #define L2CAP_CID_SIGNALING_LE              0x0005
00077 #define L2CAP_CID_SECURITY_MANAGER_PROTOCOL 0x0006
00078     
00079 void l2cap_init(void);
00080 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size));
00081 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, uint16_t mtu);
00082 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason);
00083 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid);
00084 uint16_t l2cap_max_mtu(void);
00085 
00086 void l2cap_block_new_credits(uint8_t blocked);
00087 int  l2cap_can_send_packet_now(uint16_t local_cid);    // non-blocking UART write
00088 
00089 // get outgoing buffer and prepare data
00090 uint8_t *l2cap_get_outgoing_buffer(void);
00091 
00092 int  l2cap_send_prepared(uint16_t local_cid, uint16_t len);
00093 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len);
00094 
00095 int  l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len);
00096 int  l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len);
00097     
00098 void l2cap_close_connection(void *connection);
00099 
00100 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu);
00101 void l2cap_unregister_service_internal(void *connection, uint16_t psm);
00102 
00103 void l2cap_accept_connection_internal(uint16_t local_cid);
00104 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason);
00105 
00106 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol
00107 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id);
00108 
00109 
00110 // private structs
00111 typedef enum {
00112     L2CAP_STATE_CLOSED = 1,           // no baseband
00113     L2CAP_STATE_WILL_SEND_CREATE_CONNECTION,
00114     L2CAP_STATE_WAIT_CONNECTION_COMPLETE,
00115     L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT,
00116     L2CAP_STATE_WAIT_CONNECT_RSP, // from peer
00117     L2CAP_STATE_CONFIG,
00118     L2CAP_STATE_OPEN,
00119     L2CAP_STATE_WAIT_DISCONNECT,  // from application
00120     L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST,
00121     L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE,
00122     L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT,   
00123     L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST,
00124     L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE,
00125 } L2CAP_STATE;
00126 
00127 typedef enum {
00128     L2CAP_CHANNEL_STATE_VAR_NONE          = 0,
00129     L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ = 1 << 0,
00130     L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP = 1 << 1,
00131     L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ = 1 << 2,
00132     L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP = 1 << 3,
00133     L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ = 1 << 4,
00134     L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP = 1 << 5,
00135 } L2CAP_CHANNEL_STATE_VAR;
00136 
00137 // info regarding an actual coneection
00138 typedef struct {
00139     // linked list - assert: first field
00140     linked_item_t    item;
00141     
00142     L2CAP_STATE state;
00143     L2CAP_CHANNEL_STATE_VAR state_var;
00144     
00145     bd_addr_t address;
00146     hci_con_handle_t handle;
00147     
00148     uint8_t   remote_sig_id;    // used by other side, needed for delayed response
00149     uint8_t   local_sig_id;     // own signaling identifier
00150     
00151     uint16_t  local_cid;
00152     uint16_t  remote_cid;
00153     
00154     uint16_t  local_mtu;
00155     uint16_t  remote_mtu;
00156     
00157     uint16_t  psm;
00158     
00159     uint8_t   packets_granted;    // number of L2CAP/ACL packets client is allowed to send
00160     
00161     uint8_t   reason; // used in decline internal
00162     
00163     // client connection
00164     void * connection;
00165     
00166     // internal connection
00167     btstack_packet_handler_t packet_handler;
00168     
00169 } l2cap_channel_t;
00170 
00171 // info regarding potential connections
00172 typedef struct {
00173     // linked list - assert: first field
00174     linked_item_t    item;
00175     
00176     // service id
00177     uint16_t  psm;
00178     
00179     // incoming MTU
00180     uint16_t mtu;
00181     
00182     // client connection
00183     void *connection;    
00184     
00185     // internal connection
00186     btstack_packet_handler_t packet_handler;
00187     
00188 } l2cap_service_t;
00189 
00190 
00191 typedef struct l2cap_signaling_response {
00192     hci_con_handle_t handle;
00193     uint8_t  sig_id;
00194     uint8_t  code;
00195     uint16_t data; // infoType for INFORMATION REQUEST, result for CONNECTION request
00196 } l2cap_signaling_response_t;
00197     
00198     
00199 #if defined __cplusplus
00200 }
00201 #endif