/* * Copyright (C) 2014 BlueKitchen GmbH * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the copyright holders nor the names of * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * 4. Any redistribution, use, or modification is done solely for * personal benefit and not for any commercial purpose or for * monetary gain. * * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * Please inquire about commercial licensing options at * contact@bluekitchen-gmbh.com * */ #define BTSTACK_FILE__ "att_dispatch.c" /** * Dispatcher for independent implementation of ATT client and server */ #include "ble/att_dispatch.h" #include "ble/core.h" #include "btstack_debug.h" #include "l2cap.h" #include "btstack_event.h" #define ATT_SERVER 0u #define ATT_CLIENT 1u #define ATT_MAX 2u struct { btstack_packet_handler_t packet_handler; bool waiting_for_can_send; } subscriptions[ATT_MAX]; // index of subscription that will get can send now first if waiting for it static uint8_t att_round_robin; // track can send now requests static bool can_send_now_pending; #ifdef ENABLE_GATT_OVER_CLASSIC static att_server_t * att_dispatch_att_server_for_l2cap_cid(uint16_t l2cap_cid){ btstack_linked_list_iterator_t it; hci_connections_get_iterator(&it); while(btstack_linked_list_iterator_has_next(&it)) { hci_connection_t *hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); att_server_t *att_server = &hci_connection->att_server; if (att_server->l2cap_cid == l2cap_cid){ return att_server; } } return NULL; } #endif static void att_dispatch_handle_can_send_now(uint8_t *packet, uint16_t size){ uint8_t i; uint8_t index; uint16_t l2cap_cid = l2cap_event_can_send_now_get_local_cid(packet); #ifdef ENABLE_GATT_OVER_CLASSIC if (l2cap_cid != L2CAP_CID_ATTRIBUTE_PROTOCOL){ att_server_t * att_server = att_dispatch_att_server_for_l2cap_cid(l2cap_cid); if (att_server != NULL){ for (i = 0u; i < ATT_MAX; i++) { index = (att_round_robin + i) & 1u; if (att_server->send_requests[index]) { att_server->send_requests[index] = false; // registered packet handlers from Unenhanced LE subscriptions[index].packet_handler(HCI_EVENT_PACKET, l2cap_cid, packet, size); // fairness: prioritize next service att_round_robin = (index + 1u) % ATT_MAX; // stop if client cannot send anymore if (!l2cap_can_send_packet_now(l2cap_cid)) break; } } // check if more can send now events are needed bool send_request_pending = att_server->send_requests[ATT_CLIENT] || att_server->send_requests[ATT_SERVER]; if (send_request_pending){ l2cap_request_can_send_now_event(att_server->l2cap_cid); } return; } } #endif can_send_now_pending = false; for (i = 0u; i < ATT_MAX; i++){ index = (att_round_robin + i) & 1u; if ( (subscriptions[index].packet_handler != NULL) && subscriptions[index].waiting_for_can_send){ subscriptions[index].waiting_for_can_send = false; subscriptions[index].packet_handler(HCI_EVENT_PACKET, l2cap_cid, packet, size); // fairness: prioritize next service att_round_robin = (index + 1u) % ATT_MAX; // stop if client cannot send anymore if (!hci_can_send_acl_le_packet_now()) break; } } // check if more can send now events are needed if (!can_send_now_pending){ for (i = 0u; i < ATT_MAX; i++){ if ((subscriptions[i].packet_handler != NULL) && subscriptions[i].waiting_for_can_send){ can_send_now_pending = true; // note: con_handle is not used, so we can pass in anything l2cap_request_can_send_fix_channel_now_event(0, L2CAP_CID_ATTRIBUTE_PROTOCOL); break; } } } } static void att_dispatch_handle_att_pdu(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ uint8_t index; uint8_t opcode; uint8_t method; bool for_server; bool invalid; // parse opcode opcode = packet[0u]; method = opcode & 0x03fu; invalid = method > ATT_MULTIPLE_HANDLE_VALUE_NTF; // odd PDUs are sent from server to client - even PDUs are sent from client to server, also let server handle invalid ones for_server = ((method & 1u) == 0u) || invalid; index = for_server ? ATT_SERVER : ATT_CLIENT; if (!subscriptions[index].packet_handler) return; subscriptions[index].packet_handler(packet_type, channel, packet, size); } static void att_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ #ifdef ENABLE_GATT_OVER_CLASSIC hci_connection_t * hci_connection; att_server_t * att_server; hci_con_handle_t con_handle; bool outgoing_active; uint8_t index; bd_addr_t address; uint16_t l2cap_cid; uint8_t status; #endif switch (packet_type){ case ATT_DATA_PACKET: att_dispatch_handle_att_pdu(packet_type, channel, packet, size); break; #ifdef ENABLE_GATT_OVER_CLASSIC case L2CAP_DATA_PACKET: att_dispatch_handle_att_pdu(packet_type, channel, packet, size); break; #endif case HCI_EVENT_PACKET: switch (hci_event_packet_get_type(packet)) { case L2CAP_EVENT_CAN_SEND_NOW: att_dispatch_handle_can_send_now(packet, size); break; #ifdef ENABLE_GATT_OVER_CLASSIC case L2CAP_EVENT_INCOMING_CONNECTION: l2cap_event_incoming_connection_get_address(packet, address); l2cap_cid = l2cap_event_incoming_connection_get_local_cid(packet); // reject if outgoing l2cap connection active, L2CAP/TIM/BV-01-C con_handle = l2cap_event_incoming_connection_get_handle(packet); hci_connection = hci_connection_for_handle(con_handle); btstack_assert(hci_connection != NULL); outgoing_active = hci_connection->att_server.l2cap_cid != 0; if (outgoing_active) { hci_connection->att_server.incoming_connection_request = true; l2cap_decline_connection(l2cap_cid); log_info("Decline incoming connection from %s", bd_addr_to_str(address)); } else { l2cap_accept_connection(l2cap_cid); log_info("Accept incoming connection from %s", bd_addr_to_str(address)); } break; case L2CAP_EVENT_CHANNEL_OPENED: // store l2cap_cid in att_server status = l2cap_event_channel_opened_get_status(packet); con_handle = l2cap_event_channel_opened_get_handle(packet); hci_connection = hci_connection_for_handle(con_handle); if (status == ERROR_CODE_SUCCESS){ btstack_assert(hci_connection != NULL); hci_connection->att_server.l2cap_cid = l2cap_event_channel_opened_get_local_cid(packet); } else { if (hci_connection != NULL){ hci_connection->att_server.l2cap_cid = 0; } } // dispatch to all roles for (index = 0; index < ATT_MAX; index++){ if (subscriptions[index].packet_handler != NULL){ subscriptions[index].packet_handler(packet_type, channel, packet, size); } } break; case L2CAP_EVENT_CHANNEL_CLOSED: // clear l2cap_cid in att_server l2cap_cid = l2cap_event_channel_closed_get_local_cid(packet); att_server = att_dispatch_att_server_for_l2cap_cid(l2cap_cid); att_server->l2cap_cid = 0; // dispatch to all roles for (index = 0; index < ATT_MAX; index++){ if (subscriptions[index].packet_handler != NULL){ subscriptions[index].packet_handler(packet_type, channel, packet, size); } } break; #endif default: break; } break; default: break; } } void att_dispatch_register_client(btstack_packet_handler_t packet_handler){ subscriptions[ATT_CLIENT].packet_handler = packet_handler; l2cap_register_fixed_channel(att_packet_handler, L2CAP_CID_ATTRIBUTE_PROTOCOL); } void att_dispatch_register_server(btstack_packet_handler_t packet_handler){ subscriptions[ATT_SERVER].packet_handler = packet_handler; l2cap_register_fixed_channel(att_packet_handler, L2CAP_CID_ATTRIBUTE_PROTOCOL); } #ifdef ENABLE_GATT_OVER_CLASSIC static uint16_t att_dispatch_classic_get_l2cap_cid(hci_con_handle_t con_handle){ // get l2cap_cid from att_server in hci_connection hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if (hci_connection != NULL) { return hci_connection->att_server.l2cap_cid; } else { return 0; } } #endif static bool att_dispatch_can_send_now(hci_con_handle_t con_handle) { #ifdef ENABLE_GATT_OVER_CLASSIC uint16_t l2cap_cid = att_dispatch_classic_get_l2cap_cid(con_handle); if (l2cap_cid != 0){ return l2cap_can_send_packet_now(l2cap_cid); } #endif return l2cap_can_send_fixed_channel_packet_now(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL); } bool att_dispatch_client_can_send_now(hci_con_handle_t con_handle){ return att_dispatch_can_send_now(con_handle); } bool att_dispatch_server_can_send_now(hci_con_handle_t con_handle){ return att_dispatch_can_send_now(con_handle); } static void att_dispatch_request_can_send_now_event(hci_con_handle_t con_handle, uint8_t type) { #ifdef ENABLE_GATT_OVER_CLASSIC hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if (hci_connection != NULL) { att_server_t * att_server = &hci_connection->att_server; if (att_server->l2cap_cid != 0){ bool send_request_pending = att_server->send_requests[ATT_CLIENT] || att_server->send_requests[ATT_SERVER]; att_server->send_requests[type] = true; if (send_request_pending == false){ l2cap_request_can_send_now_event(att_server->l2cap_cid); } return; } } #endif subscriptions[type].waiting_for_can_send = true; if (can_send_now_pending == false) { can_send_now_pending = true; l2cap_request_can_send_fix_channel_now_event(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL); } } void att_dispatch_client_request_can_send_now_event(hci_con_handle_t con_handle){ att_dispatch_request_can_send_now_event(con_handle, ATT_CLIENT); } void att_dispatch_server_request_can_send_now_event(hci_con_handle_t con_handle){ att_dispatch_request_can_send_now_event(con_handle, ATT_SERVER); } static void emit_mtu_exchange_complete(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, uint16_t new_mtu){ if (!packet_handler) return; uint8_t packet[6]; packet[0] = ATT_EVENT_MTU_EXCHANGE_COMPLETE; packet[1] = sizeof(packet) - 2u; little_endian_store_16(packet, 2, con_handle); little_endian_store_16(packet, 4, new_mtu); packet_handler(HCI_EVENT_PACKET, con_handle, packet, 6); } void att_dispatch_server_mtu_exchanged(hci_con_handle_t con_handle, uint16_t new_mtu){ emit_mtu_exchange_complete(subscriptions[ATT_CLIENT].packet_handler, con_handle, new_mtu); } void att_dispatch_client_mtu_exchanged(hci_con_handle_t con_handle, uint16_t new_mtu){ emit_mtu_exchange_complete(subscriptions[ATT_SERVER].packet_handler, con_handle, new_mtu); } #ifdef ENABLE_GATT_OVER_CLASSIC void att_dispatch_classic_register_service(void){ l2cap_register_service(&att_packet_handler, PSM_ATT, 0xffff, gap_get_security_level()); } uint8_t att_dispatch_classic_connect(bd_addr_t address, uint16_t l2cap_psm, uint16_t *out_cid) { uint16_t l2cap_cid; uint8_t status = l2cap_create_channel(&att_packet_handler, address, l2cap_psm, 0xffff, &l2cap_cid); // store l2cap_cid in hci_connection if (status == ERROR_CODE_SUCCESS){ hci_connection_t * hci_connection = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_ACL); if (hci_connection != NULL) { hci_connection->att_server.l2cap_cid = l2cap_cid; hci_connection->att_server.incoming_connection_request = false; } } *out_cid = l2cap_cid; return status; } #endif