/* * 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 MATTHIAS * RINGWALD 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 * */ /* * l2cap.c * * Logical Link Control and Adaption Protocl (L2CAP) * * Created by Matthias Ringwald on 5/16/09. */ #include "l2cap.h" #include "hci.h" #include "hci_dump.h" #include "btstack_debug.h" #include "btstack_event.h" #include "btstack_memory.h" #ifdef ENABLE_LE_DATA_CHANNELS #include "ble/sm.h" #endif #include #include #include // nr of buffered acl packets in outgoing queue to get max performance #define NR_BUFFERED_ACL_PACKETS 3 // used to cache l2cap rejects, echo, and informational requests #define NR_PENDING_SIGNALING_RESPONSES 3 // nr of credits provided to remote if credits fall below watermark #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 // offsets for L2CAP SIGNALING COMMANDS #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 // internal table #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) #if defined(ENABLE_LE_DATA_CHANNELS) || defined(ENABLE_CLASSIC) #define L2CAP_USES_CHANNELS #endif // prototypes static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); static void l2cap_notify_channel_can_send(void); static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); #ifdef ENABLE_CLASSIC static void l2cap_finialize_channel_close(l2cap_channel_t *channel); static inline l2cap_service_t * l2cap_get_service(uint16_t psm); static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); static void l2cap_emit_channel_closed(l2cap_channel_t *channel); static void l2cap_emit_incoming_connection(l2cap_channel_t *channel); static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); #endif #ifdef ENABLE_LE_DATA_CHANNELS static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status); static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel); static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid); static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel); static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); #endif typedef struct l2cap_fixed_channel { btstack_packet_handler_t callback; uint8_t waiting_for_can_send_now; } l2cap_fixed_channel_t; #ifdef ENABLE_CLASSIC static btstack_linked_list_t l2cap_channels; static btstack_linked_list_t l2cap_services; static uint8_t require_security_level2_for_outgoing_sdp; #endif #ifdef ENABLE_LE_DATA_CHANNELS static btstack_linked_list_t l2cap_le_channels; static btstack_linked_list_t l2cap_le_services; #endif // used to cache l2cap rejects, echo, and informational requests static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; static int signaling_responses_pending; static btstack_packet_callback_registration_t hci_event_callback_registration; static btstack_packet_handler_t l2cap_event_packet_handler; static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ switch (index){ case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: return L2CAP_CID_ATTRIBUTE_PROTOCOL; case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: return L2CAP_CID_CONNECTIONLESS_CHANNEL; default: return 0; } } static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ switch (channel_id){ case L2CAP_CID_ATTRIBUTE_PROTOCOL: return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; case L2CAP_CID_CONNECTIONLESS_CHANNEL: return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; default: return -1; } } static int l2cap_fixed_channel_table_index_is_le(int index){ if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; return 1; } void l2cap_init(void){ signaling_responses_pending = 0; #ifdef ENABLE_CLASSIC l2cap_channels = NULL; l2cap_services = NULL; require_security_level2_for_outgoing_sdp = 0; #endif #ifdef ENABLE_LE_DATA_CHANNELS l2cap_le_services = NULL; l2cap_le_channels = NULL; #endif l2cap_event_packet_handler = NULL; memset(fixed_channels, 0, sizeof(fixed_channels)); // // register callback with HCI // hci_event_callback_registration.callback = &l2cap_hci_event_handler; hci_add_event_handler(&hci_event_callback_registration); hci_register_acl_packet_handler(&l2cap_acl_handler); #ifdef ENABLE_CLASSIC gap_connectable_control(0); // no services yet #endif } void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ l2cap_event_packet_handler = handler; } void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ UNUSED(con_handle); int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); if (index < 0) return; fixed_channels[index].waiting_for_can_send_now = 1; l2cap_notify_channel_can_send(); } int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ UNUSED(channel_id); return hci_can_send_acl_packet_now(con_handle); } uint8_t *l2cap_get_outgoing_buffer(void){ return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes } int l2cap_reserve_packet_buffer(void){ return hci_reserve_packet_buffer(); } void l2cap_release_packet_buffer(void){ hci_release_packet_buffer(); } static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint8_t packet_boundary, uint16_t remote_cid, uint16_t len){ // 0 - Connection handle : PB=pb : BC=00 little_endian_store_16(acl_buffer, 0, con_handle | (packet_boundary << 12) | (0 << 14)); // 2 - ACL length little_endian_store_16(acl_buffer, 2, len + 4); // 4 - L2CAP packet length little_endian_store_16(acl_buffer, 4, len + 0); // 6 - L2CAP channel DEST little_endian_store_16(acl_buffer, 6, remote_cid); } // assumption - only on LE connections int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ if (!hci_is_packet_buffer_reserved()){ log_error("l2cap_send_prepared_connectionless called without reserving packet first"); return BTSTACK_ACL_BUFFERS_FULL; } if (!hci_can_send_prepared_acl_packet_now(con_handle)){ log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); return BTSTACK_ACL_BUFFERS_FULL; } log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); l2cap_setup_header(acl_buffer, con_handle, 0, cid, len); // send return hci_send_acl_packet_buffer(len+8); } // assumption - only on LE connections int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ if (!hci_can_send_acl_packet_now(con_handle)){ log_info("l2cap_send cid 0x%02x, cannot send", cid); return BTSTACK_ACL_BUFFERS_FULL; } hci_reserve_packet_buffer(); uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); memcpy(&acl_buffer[8], data, len); return l2cap_send_prepared_connectionless(con_handle, cid, len); } static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { log_info("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); uint8_t event[4]; event[0] = L2CAP_EVENT_CAN_SEND_NOW; event[1] = sizeof(event) - 2; little_endian_store_16(event, 2, channel); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); } #ifdef L2CAP_USES_CHANNELS static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ (* (channel->packet_handler))(type, channel->local_cid, data, size); } static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ uint8_t event[4]; event[0] = event_code; event[1] = sizeof(event) - 2; little_endian_store_16(event, 2, channel->local_cid); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); } #endif #ifdef ENABLE_CLASSIC void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { log_info("L2CAP_EVENT_CHANNEL_OPENED status 0x%x addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u, flush_timeout %u", status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); uint8_t event[24]; event[0] = L2CAP_EVENT_CHANNEL_OPENED; event[1] = sizeof(event) - 2; event[2] = status; reverse_bd_addr(channel->address, &event[3]); little_endian_store_16(event, 9, channel->con_handle); little_endian_store_16(event, 11, channel->psm); little_endian_store_16(event, 13, channel->local_cid); little_endian_store_16(event, 15, channel->remote_cid); little_endian_store_16(event, 17, channel->local_mtu); little_endian_store_16(event, 19, channel->remote_mtu); little_endian_store_16(event, 21, channel->flush_timeout); event[23] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); } static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); } static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); uint8_t event[16]; event[0] = L2CAP_EVENT_INCOMING_CONNECTION; event[1] = sizeof(event) - 2; reverse_bd_addr(channel->address, &event[2]); little_endian_store_16(event, 8, channel->con_handle); little_endian_store_16(event, 10, channel->psm); little_endian_store_16(event, 12, channel->local_cid); little_endian_store_16(event, 14, channel->remote_cid); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); } static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &l2cap_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if ( channel->local_cid == local_cid) { return channel; } } return NULL; } /// void l2cap_request_can_send_now_event(uint16_t local_cid){ l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); if (!channel) return; channel->waiting_for_can_send_now = 1; l2cap_notify_channel_can_send(); } int l2cap_can_send_packet_now(uint16_t local_cid){ l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); if (!channel) return 0; return hci_can_send_acl_packet_now(channel->con_handle); } int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); if (!channel) return 0; return hci_can_send_prepared_acl_packet_now(channel->con_handle); } uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); if (channel) { return channel->remote_mtu; } return 0; } static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &l2cap_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if ( &channel->rtx == ts) { return channel; } } return NULL; } static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); if (!channel) return; log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." // notify client l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); // discard channel // no need to stop timer here, it is removed from list during timer callback btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); btstack_memory_l2cap_channel_free(channel); } static void l2cap_stop_rtx(l2cap_channel_t * channel){ log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); btstack_run_loop_remove_timer(&channel->rtx); } static void l2cap_start_rtx(l2cap_channel_t * channel){ l2cap_stop_rtx(channel); log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); btstack_run_loop_add_timer(&channel->rtx); } static void l2cap_start_ertx(l2cap_channel_t * channel){ log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); l2cap_stop_rtx(channel); btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); btstack_run_loop_add_timer(&channel->rtx); } void l2cap_require_security_level_2_for_outgoing_sdp(void){ require_security_level2_for_outgoing_sdp = 1; } static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); } static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ if (!hci_can_send_acl_packet_now(handle)){ log_info("l2cap_send_signaling_packet, cannot send"); return BTSTACK_ACL_BUFFERS_FULL; } // log_info("l2cap_send_signaling_packet type %u", cmd); hci_reserve_packet_buffer(); uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); va_list argptr; va_start(argptr, identifier); uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); va_end(argptr); // log_info("l2cap_send_signaling_packet con %u!", handle); return hci_send_acl_packet_buffer(len); } // assumption - only on Classic connections int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ if (!hci_is_packet_buffer_reserved()){ log_error("l2cap_send_prepared called without reserving packet first"); return BTSTACK_ACL_BUFFERS_FULL; } l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); if (!channel) { log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); return -1; // TODO: define error } if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); return BTSTACK_ACL_BUFFERS_FULL; } log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); // set non-flushable packet boundary flag if supported on Controller uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); uint8_t packet_boundary_flag = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; l2cap_setup_header(acl_buffer, channel->con_handle, packet_boundary_flag, channel->remote_cid, len); // send return hci_send_acl_packet_buffer(len+8); } // assumption - only on Classic connections int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); if (!channel) { log_error("l2cap_send no channel for cid 0x%02x", local_cid); return -1; // TODO: define error } if (len > channel->remote_mtu){ log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; } if (!hci_can_send_acl_packet_now(channel->con_handle)){ log_info("l2cap_send cid 0x%02x, cannot send", local_cid); return BTSTACK_ACL_BUFFERS_FULL; } hci_reserve_packet_buffer(); uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); memcpy(&acl_buffer[8], data, len); return l2cap_send_prepared(local_cid, len); } int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); } static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); } static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); } #endif #ifdef ENABLE_BLE static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ if (!hci_can_send_acl_packet_now(handle)){ log_info("l2cap_send_le_signaling_packet, cannot send"); return BTSTACK_ACL_BUFFERS_FULL; } // log_info("l2cap_send_le_signaling_packet type %u", cmd); hci_reserve_packet_buffer(); uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); va_list argptr; va_start(argptr, identifier); uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); va_end(argptr); // log_info("l2cap_send_le_signaling_packet con %u!", handle); return hci_send_acl_packet_buffer(len); } #endif uint16_t l2cap_max_mtu(void){ return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; } uint16_t l2cap_max_le_mtu(void){ return l2cap_max_mtu(); } // MARK: L2CAP_RUN // process outstanding signaling tasks static void l2cap_run(void){ // log_info("l2cap_run: entered"); // check pending signaling responses while (signaling_responses_pending){ hci_con_handle_t handle = signaling_responses[0].handle; if (!hci_can_send_acl_packet_now(handle)) break; uint8_t sig_id = signaling_responses[0].sig_id; uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT uint8_t response_code = signaling_responses[0].code; UNUSED(infoType); // remove first item before sending (to avoid sending response mutliple times) signaling_responses_pending--; int i; for (i=0; i < signaling_responses_pending; i++){ memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); } switch (response_code){ #ifdef ENABLE_CLASSIC case CONNECTION_REQUEST: l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); // also disconnect if result is 0x0003 - security blocked if (result == 0x0003){ hci_disconnect_security_block(handle); } break; case ECHO_REQUEST: l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); break; case INFORMATION_REQUEST: switch (infoType){ case 1: { // Connectionless MTU uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); } break; case 2: { // Extended Features Supported // extended features request supported, features: fixed channels, unicast connectionless data reception uint32_t features = 0x280; l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); } break; case 3: { // Fixed Channels Supported uint8_t map[8]; memset(map, 0, 8); map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); } break; default: // all other types are not supported l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); break; } break; case COMMAND_REJECT: l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); break; #endif #ifdef ENABLE_BLE case LE_CREDIT_BASED_CONNECTION_REQUEST: l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); break; case COMMAND_REJECT_LE: l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); break; #endif default: // should not happen break; } } btstack_linked_list_iterator_t it; UNUSED(it); #ifdef ENABLE_CLASSIC uint8_t config_options[4]; btstack_linked_list_iterator_init(&it, &l2cap_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); switch (channel->state){ case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); } break; case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: if (!hci_can_send_command_packet_now()) break; // send connection request - set state first channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); break; case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; channel->state = L2CAP_STATE_INVALID; l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); // discard channel - l2cap_finialize_channel_close without sending l2cap close event l2cap_stop_rtx(channel); btstack_linked_list_iterator_remove(&it); btstack_memory_l2cap_channel_free(channel); break; case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; channel->state = L2CAP_STATE_CONFIG; channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); break; case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; // success, start l2cap handshake channel->local_sig_id = l2cap_next_sig_id(); channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); l2cap_start_rtx(channel); break; case L2CAP_STATE_CONFIG: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ uint16_t flags = 0; channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { flags = 1; } else { channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); } if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ config_options[0] = 1; // MTU config_options[1] = 2; // len param little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); } else { l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); } channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); channel->local_sig_id = l2cap_next_sig_id(); config_options[0] = 1; // MTU config_options[1] = 2; // len param little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); l2cap_start_rtx(channel); } if (l2cap_channel_ready_for_open(channel)){ channel->state = L2CAP_STATE_OPEN; l2cap_emit_channel_opened(channel, 0); // success } break; case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; channel->state = L2CAP_STATE_INVALID; l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); // we don't start an RTX timer for a disconnect - there's no point in closing the channel if the other side doesn't respond :) l2cap_finialize_channel_close(channel); // -- remove from list break; case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; channel->local_sig_id = l2cap_next_sig_id(); channel->state = L2CAP_STATE_WAIT_DISCONNECT; l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); break; default: break; } } #endif #ifdef ENABLE_LE_DATA_CHANNELS btstack_linked_list_iterator_init(&it, &l2cap_le_channels); while (btstack_linked_list_iterator_has_next(&it)){ uint8_t * acl_buffer; uint8_t * l2cap_payload; uint16_t pos; uint16_t payload_size; l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); switch (channel->state){ case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; // le psm, source cid, mtu, mps, initial credits channel->local_sig_id = l2cap_next_sig_id(); channel->credits_incoming = channel->new_credits_incoming; channel->new_credits_incoming = 0; l2cap_send_le_signaling_packet( channel->con_handle, LE_CREDIT_BASED_CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid, channel->local_mtu, 23, channel->credits_incoming); break; case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; // TODO: support larger MPS channel->state = L2CAP_STATE_OPEN; channel->credits_incoming = channel->new_credits_incoming; channel->new_credits_incoming = 0; l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->local_mtu, 23, channel->credits_incoming, 0); // notify client l2cap_emit_le_channel_opened(channel, 0); break; case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; channel->state = L2CAP_STATE_INVALID; l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); // discard channel - l2cap_finialize_channel_close without sending l2cap close event l2cap_stop_rtx(channel); btstack_linked_list_iterator_remove(&it); btstack_memory_l2cap_channel_free(channel); break; case L2CAP_STATE_OPEN: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; // send credits if (channel->new_credits_incoming){ log_info("l2cap: sending %u credits", channel->new_credits_incoming); channel->local_sig_id = l2cap_next_sig_id(); uint16_t new_credits = channel->new_credits_incoming; channel->new_credits_incoming = 0; channel->credits_incoming += new_credits; l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); break; } // send data if (!channel->send_sdu_buffer) break; if (!channel->credits_outgoing) break; // send part of SDU hci_reserve_packet_buffer(); acl_buffer = hci_get_outgoing_packet_buffer(); l2cap_payload = acl_buffer + 8; pos = 0; if (!channel->send_sdu_pos){ // store SDU len channel->send_sdu_pos += 2; little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); pos += 2; } payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len pos += payload_size; channel->send_sdu_pos += payload_size; l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); // done channel->credits_outgoing--; if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ channel->send_sdu_buffer = NULL; // send done event l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); // inform about can send now l2cap_le_notify_channel_can_send(channel); } hci_send_acl_packet_buffer(8 + pos); break; case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; channel->local_sig_id = l2cap_next_sig_id(); channel->state = L2CAP_STATE_WAIT_DISCONNECT; l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); break; case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: if (!hci_can_send_acl_packet_now(channel->con_handle)) break; channel->state = L2CAP_STATE_INVALID; l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); l2cap_le_finialize_channel_close(channel); // -- remove from list break; default: break; } } #endif #ifdef ENABLE_BLE // send l2cap con paramter update if necessary hci_connections_get_iterator(&it); while(btstack_linked_list_iterator_has_next(&it)){ hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; switch (connection->le_con_parameter_update_state){ case CON_PARAMETER_UPDATE_SEND_REQUEST: connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); break; case CON_PARAMETER_UPDATE_SEND_RESPONSE: connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); break; case CON_PARAMETER_UPDATE_DENY: connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); break; default: break; } } #endif // log_info("l2cap_run: exit"); } #ifdef ENABLE_CLASSIC static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { log_info("l2cap_handle_connection_complete expected state"); // success, start l2cap handshake channel->con_handle = con_handle; // check remote SSP feature first channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; } } static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; // we have been waiting for remote supported features, if both support SSP, log_info("l2cap received remote supported features, sec_level_0_allowed for psm %u = %u", channel->psm, l2cap_security_level_0_allowed_for_PSM(channel->psm)); if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ // request security level 2 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; gap_request_security_level(channel->con_handle, LEVEL_2); return; } // fine, go ahead channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; } #endif #ifdef L2CAP_USES_CHANNELS static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); if (!channel) { return NULL; } // Init memory (make valgrind happy) memset(channel, 0, sizeof(l2cap_channel_t)); // fill in channel->packet_handler = packet_handler; bd_addr_copy(channel->address, address); channel->address_type = address_type; channel->psm = psm; channel->local_mtu = local_mtu; channel->remote_mtu = L2CAP_MINIMAL_MTU; channel->required_security_level = security_level; // channel->local_cid = l2cap_next_local_cid(); channel->con_handle = 0; // set initial state channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; channel->remote_sig_id = L2CAP_SIG_ID_INVALID; channel->local_sig_id = L2CAP_SIG_ID_INVALID; return channel; } #endif #ifdef ENABLE_CLASSIC /** * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. * @param packet_handler * @param address * @param psm * @param mtu * @param local_cid */ uint8_t l2cap_create_channel(btstack_packet_handler_t channel_packet_handler, bd_addr_t address, uint16_t psm, uint16_t local_mtu, uint16_t * out_local_cid){ log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); if (local_mtu > l2cap_max_mtu()) { local_mtu = l2cap_max_mtu(); } l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); if (!channel) { return BTSTACK_MEMORY_ALLOC_FAILED; } // add to connections list btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); // store local_cid if (out_local_cid){ *out_local_cid = channel->local_cid; } // check if hci connection is already usable hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); if (conn){ log_info("l2cap_create_channel, hci connection already exists"); l2cap_handle_connection_complete(conn->con_handle, channel); // check if remote supported fearures are already received if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { l2cap_handle_remote_supported_features_received(channel); } } l2cap_run(); return 0; } void l2cap_disconnect(uint16_t local_cid, uint8_t reason){ log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); // find channel for local_cid l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); if (channel) { channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; } // process l2cap_run(); } static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &l2cap_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if ( bd_addr_cmp( channel->address, address) != 0) continue; // channel for this address found switch (channel->state){ case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: // failure, forward error code l2cap_emit_channel_opened(channel, status); // discard channel l2cap_stop_rtx(channel); btstack_linked_list_iterator_remove(&it); btstack_memory_l2cap_channel_free(channel); break; default: break; } } } static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &l2cap_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if ( ! bd_addr_cmp( channel->address, address) ){ l2cap_handle_connection_complete(handle, channel); } } // process l2cap_run(); } #endif static void l2cap_notify_channel_can_send(void){ #ifdef ENABLE_CLASSIC btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &l2cap_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if (!channel->waiting_for_can_send_now) continue; if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; channel->waiting_for_can_send_now = 0; l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); } #endif int i; for (i=0;icon_handle != handle) continue; l2cap_emit_channel_closed(channel); l2cap_stop_rtx(channel); btstack_linked_list_iterator_remove(&it); btstack_memory_l2cap_channel_free(channel); } #endif #ifdef ENABLE_LE_DATA_CHANNELS handle = little_endian_read_16(packet, 3); btstack_linked_list_iterator_init(&it, &l2cap_le_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if (channel->con_handle != handle) continue; l2cap_emit_channel_closed(channel); btstack_linked_list_iterator_remove(&it); btstack_memory_l2cap_channel_free(channel); } #endif break; // HCI Connection Timeouts #ifdef ENABLE_CLASSIC case L2CAP_EVENT_TIMEOUT_CHECK: handle = little_endian_read_16(packet, 2); if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; if (hci_authentication_active_for_handle(handle)) break; hci_con_used = 0; btstack_linked_list_iterator_init(&it, &l2cap_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if (channel->con_handle != handle) continue; hci_con_used = 1; break; } if (hci_con_used) break; if (!hci_can_send_command_packet_now()) break; hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection break; case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: handle = little_endian_read_16(packet, 3); btstack_linked_list_iterator_init(&it, &l2cap_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if (channel->con_handle != handle) continue; l2cap_handle_remote_supported_features_received(channel); break; } break; case GAP_EVENT_SECURITY_LEVEL: handle = little_endian_read_16(packet, 2); log_info("l2cap - security level update"); btstack_linked_list_iterator_init(&it, &l2cap_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if (channel->con_handle != handle) continue; log_info("l2cap - state %u", channel->state); gap_security_level_t actual_level = (gap_security_level_t) packet[4]; gap_security_level_t required_level = channel->required_security_level; switch (channel->state){ case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: if (actual_level >= required_level){ channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; l2cap_emit_incoming_connection(channel); } else { channel->reason = 0x0003; // security block channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; } break; case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: if (actual_level >= required_level){ channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; } else { // disconnnect, authentication not good enough hci_disconnect_security_block(handle); } break; default: break; } } break; #endif default: break; } l2cap_run(); } static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { signaling_responses[signaling_responses_pending].handle = handle; signaling_responses[signaling_responses_pending].code = code; signaling_responses[signaling_responses_pending].sig_id = sig_id; signaling_responses[signaling_responses_pending].data = data; signaling_responses_pending++; l2cap_run(); } } #ifdef ENABLE_CLASSIC static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ channel->remote_sig_id = identifier; channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; l2cap_run(); } static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); l2cap_service_t *service = l2cap_get_service(psm); if (!service) { // 0x0002 PSM not supported l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); return; } hci_connection_t * hci_connection = hci_connection_for_handle( handle ); if (!hci_connection) { // log_error("no hci_connection for handle %u", handle); return; } // alloc structure // log_info("l2cap_handle_connection_request register channel"); l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, psm, service->mtu, service->required_security_level); if (!channel){ // 0x0004 No resources available l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); return; } channel->con_handle = handle; channel->remote_cid = source_cid; channel->remote_sig_id = sig_id; // limit local mtu to max acl packet length - l2cap header if (channel->local_mtu > l2cap_max_mtu()) { channel->local_mtu = l2cap_max_mtu(); } // set initial state channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); // add to connections list btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); // assert security requirements gap_request_security_level(handle, channel->required_security_level); } void l2cap_accept_connection(uint16_t local_cid){ log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); if (!channel) { log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); return; } channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; // process l2cap_run(); } void l2cap_decline_connection(uint16_t local_cid){ log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); if (!channel) { log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); return; } channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; channel->reason = 0x04; // no resources available l2cap_run(); } static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; uint16_t flags = little_endian_read_16(command, 6); if (flags & 1) { channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); } // accept the other's configuration options uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); uint16_t pos = 8; while (pos < end_pos){ uint8_t option_hint = command[pos] >> 7; uint8_t option_type = command[pos] & 0x7f; log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); pos++; uint8_t length = command[pos++]; // MTU { type(8): 1, len(8):2, MTU(16) } if (option_type == 1 && length == 2){ channel->remote_mtu = little_endian_read_16(command, pos); // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); } // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} if (option_type == 2 && length == 2){ channel->flush_timeout = little_endian_read_16(command, pos); } // check for unknown options if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ log_info("l2cap cid %u, unknown options", channel->local_cid); channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); } pos += length; } } static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; // addition check that fixes re-entrance issue causing l2cap event channel opened twice if (channel->state == L2CAP_STATE_OPEN) return 0; return 1; } static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; uint16_t result = 0; log_info("L2CAP signaling handler code %u, state %u", code, channel->state); // handle DISCONNECT REQUESTS seperately if (code == DISCONNECTION_REQUEST){ switch (channel->state){ case L2CAP_STATE_CONFIG: case L2CAP_STATE_OPEN: case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: case L2CAP_STATE_WAIT_DISCONNECT: l2cap_handle_disconnect_request(channel, identifier); break; default: // ignore in other states break; } return; } // @STATEMACHINE(l2cap) switch (channel->state) { case L2CAP_STATE_WAIT_CONNECT_RSP: switch (code){ case CONNECTION_RESPONSE: l2cap_stop_rtx(channel); result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); switch (result) { case 0: // successful connection channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); channel->state = L2CAP_STATE_CONFIG; channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); break; case 1: // connection pending. get some coffee, but start the ERTX l2cap_start_ertx(channel); break; default: // channel closed channel->state = L2CAP_STATE_CLOSED; // map l2cap connection response result to BTstack status enumeration l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); // drop link key if security block if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ gap_drop_link_key_for_bd_addr(channel->address); } // discard channel btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); btstack_memory_l2cap_channel_free(channel); break; } break; default: //@TODO: implement other signaling packets break; } break; case L2CAP_STATE_CONFIG: result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); switch (code) { case CONFIGURE_REQUEST: channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); l2cap_signaling_handle_configure_request(channel, command); if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ // only done if continuation not set channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); } break; case CONFIGURE_RESPONSE: l2cap_stop_rtx(channel); switch (result){ case 0: // success channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); break; case 4: // pending l2cap_start_ertx(channel); break; default: // retry on negative result channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); break; } break; default: break; } if (l2cap_channel_ready_for_open(channel)){ // for open: channel->state = L2CAP_STATE_OPEN; l2cap_emit_channel_opened(channel, 0); } break; case L2CAP_STATE_WAIT_DISCONNECT: switch (code) { case DISCONNECTION_RESPONSE: l2cap_finialize_channel_close(channel); break; default: //@TODO: implement other signaling packets break; } break; case L2CAP_STATE_CLOSED: // @TODO handle incoming requests break; case L2CAP_STATE_OPEN: //@TODO: implement other signaling packets, e.g. re-configure break; default: break; } // log_info("new state %u", channel->state); } static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ // get code, signalind identifier and command len uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); return; } // general commands without an assigned channel switch(code) { case CONNECTION_REQUEST: { uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); l2cap_handle_connection_request(handle, sig_id, psm, source_cid); return; } case ECHO_REQUEST: l2cap_register_signaling_response(handle, code, sig_id, 0); return; case INFORMATION_REQUEST: { uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); l2cap_register_signaling_response(handle, code, sig_id, infoType); return; } default: break; } // Get potential destination CID uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); // Find channel for this sig_id and connection handle btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &l2cap_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if (channel->con_handle != handle) continue; if (code & 1) { // match odd commands (responses) by previous signaling identifier if (channel->local_sig_id == sig_id) { l2cap_signaling_handler_channel(channel, command); break; } } else { // match even commands (requests) by local channel id if (channel->local_cid == dest_cid) { l2cap_signaling_handler_channel(channel, command); break; } } } } #endif #ifdef ENABLE_BLE static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ uint8_t event[6]; event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; event[1] = 4; little_endian_store_16(event, 2, con_handle); little_endian_store_16(event, 4, result); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); if (!l2cap_event_packet_handler) return; (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); } // @returns valid static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ hci_connection_t * connection; uint16_t result; uint8_t event[10]; #ifdef ENABLE_LE_DATA_CHANNELS btstack_linked_list_iterator_t it; l2cap_channel_t * channel; uint16_t local_cid; uint16_t le_psm; uint16_t new_credits; uint16_t credits_before; l2cap_service_t * service; #endif uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); switch (code){ case CONNECTION_PARAMETER_UPDATE_RESPONSE: result = little_endian_read_16(command, 4); l2cap_emit_connection_parameter_update_response(handle, result); break; case CONNECTION_PARAMETER_UPDATE_REQUEST: connection = hci_connection_for_handle(handle); if (connection){ if (connection->role != HCI_ROLE_MASTER){ // reject command without notifying upper layer when not in master role return 0; } int update_parameter = 1; le_connection_parameter_range_t existing_range; gap_get_connection_parameter_range(&existing_range); uint16_t le_conn_interval_min = little_endian_read_16(command,8); uint16_t le_conn_interval_max = little_endian_read_16(command,10); uint16_t le_conn_latency = little_endian_read_16(command,12); uint16_t le_supervision_timeout = little_endian_read_16(command,14); if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; if (update_parameter){ connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; connection->le_conn_interval_min = le_conn_interval_min; connection->le_conn_interval_max = le_conn_interval_max; connection->le_conn_latency = le_conn_latency; connection->le_supervision_timeout = le_supervision_timeout; } else { connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; } connection->le_con_param_update_identifier = sig_id; } if (!l2cap_event_packet_handler) break; event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; event[1] = 8; memcpy(&event[2], &command[4], 8); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); break; #ifdef ENABLE_LE_DATA_CHANNELS case COMMAND_REJECT: // Find channel for this sig_id and connection handle channel = NULL; btstack_linked_list_iterator_init(&it, &l2cap_le_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if (a_channel->con_handle != handle) continue; if (a_channel->local_sig_id != sig_id) continue; channel = a_channel; break; } if (!channel) break; // if received while waiting for le connection response, assume legacy device if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ channel->state = L2CAP_STATE_CLOSED; // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 l2cap_emit_le_channel_opened(channel, 0x0002); // discard channel btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); btstack_memory_l2cap_channel_free(channel); break; } break; case LE_CREDIT_BASED_CONNECTION_REQUEST: // get hci connection, bail if not found (must not happen) connection = hci_connection_for_handle(handle); if (!connection) return 0; // check if service registered le_psm = little_endian_read_16(command, 4); service = l2cap_le_get_service(le_psm); if (service){ uint16_t source_cid = little_endian_read_16(command, 6); if (source_cid < 0x40){ // 0x0009 Connection refused - Invalid Source CID l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); return 1; } // go through list of channels for this ACL connection and check if we get a match btstack_linked_list_iterator_init(&it, &l2cap_le_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if (a_channel->con_handle != handle) continue; if (a_channel->remote_cid != source_cid) continue; // 0x000a Connection refused - Source CID already allocated l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); return 1; } // security: check encryption if (service->required_security_level >= LEVEL_2){ if (sm_encryption_key_size(handle) == 0){ // 0x0008 Connection refused - insufficient encryption l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0008); return 1; } // anything less than 16 byte key size is insufficient if (sm_encryption_key_size(handle) < 16){ // 0x0007 Connection refused – insufficient encryption key size l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0007); return 1; } } // security: check authencation if (service->required_security_level >= LEVEL_3){ if (!sm_authenticated(handle)){ // 0x0005 Connection refused – insufficient authentication l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0005); return 1; } } // security: check authorization if (service->required_security_level >= LEVEL_4){ if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ // 0x0006 Connection refused – insufficient authorization l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0006); return 1; } } // allocate channel channel = l2cap_create_channel_entry(service->packet_handler, connection->address, BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); if (!channel){ // 0x0004 Connection refused – no resources available l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); return 1; } channel->con_handle = handle; channel->remote_cid = source_cid; channel->remote_sig_id = sig_id; channel->remote_mtu = little_endian_read_16(command, 8); channel->remote_mps = little_endian_read_16(command, 10); channel->credits_outgoing = little_endian_read_16(command, 12); // set initial state channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; // add to connections list btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); // post connection request event l2cap_emit_le_incoming_connection(channel); } else { // Connection refused – LE_PSM not supported l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); } break; case LE_CREDIT_BASED_CONNECTION_RESPONSE: // Find channel for this sig_id and connection handle channel = NULL; btstack_linked_list_iterator_init(&it, &l2cap_le_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if (a_channel->con_handle != handle) continue; if (a_channel->local_sig_id != sig_id) continue; channel = a_channel; break; } if (!channel) break; // cid + 0 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); if (result){ channel->state = L2CAP_STATE_CLOSED; // map l2cap connection response result to BTstack status enumeration l2cap_emit_le_channel_opened(channel, result); // discard channel btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); btstack_memory_l2cap_channel_free(channel); break; } // success channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); channel->state = L2CAP_STATE_OPEN; l2cap_emit_le_channel_opened(channel, result); break; case LE_FLOW_CONTROL_CREDIT: // find channel local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); channel = l2cap_le_get_channel_for_local_cid(local_cid); if (!channel) { log_error("l2cap: no channel for cid 0x%02x", local_cid); break; } new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); credits_before = channel->credits_outgoing; channel->credits_outgoing += new_credits; // check for credit overrun if (credits_before > channel->credits_outgoing){ log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; break; } log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); break; case DISCONNECTION_REQUEST: // find channel local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); channel = l2cap_le_get_channel_for_local_cid(local_cid); if (!channel) { log_error("l2cap: no channel for cid 0x%02x", local_cid); break; } channel->remote_sig_id = sig_id; channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; break; #endif case DISCONNECTION_RESPONSE: break; default: // command unknown -> reject command return 0; } return 1; } #endif static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ UNUSED(packet_type); UNUSED(channel); l2cap_channel_t * l2cap_channel; UNUSED(l2cap_channel); // Get Channel ID uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); switch (channel_id) { #ifdef ENABLE_CLASSIC case L2CAP_CID_SIGNALING: { uint16_t command_offset = 8; while (command_offset < size) { // handle signaling commands l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); // increment command_offset command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); } break; } #endif #ifdef ENABLE_BLE case L2CAP_CID_SIGNALING_LE: { uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); if (!valid){ l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); } break; } #endif case L2CAP_CID_ATTRIBUTE_PROTOCOL: if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); } break; case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); } break; case L2CAP_CID_CONNECTIONLESS_CHANNEL: if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); } break; default: #ifdef ENABLE_CLASSIC // Find channel for this channel_id and connection handle l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); if (l2cap_channel) { l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); } #endif #ifdef ENABLE_LE_DATA_CHANNELS l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); if (l2cap_channel) { // credit counting if (l2cap_channel->credits_incoming == 0){ log_error("LE Data Channel packet received but no incoming credits"); l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; break; } l2cap_channel->credits_incoming--; // automatic credits if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; } // first fragment uint16_t pos = 0; if (!l2cap_channel->receive_sdu_len){ l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); l2cap_channel->receive_sdu_pos = 0; pos += 2; size -= 2; } memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; // done? log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); l2cap_channel->receive_sdu_len = 0; } } else { log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); } #endif break; } l2cap_run(); } // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); if (index < 0) return; fixed_channels[index].callback = the_packet_handler; } #ifdef ENABLE_CLASSIC // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE void l2cap_finialize_channel_close(l2cap_channel_t * channel){ channel->state = L2CAP_STATE_CLOSED; l2cap_emit_channel_closed(channel); // discard channel l2cap_stop_rtx(channel); btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); btstack_memory_l2cap_channel_free(channel); } static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, services); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); if ( service->psm == psm){ return service; }; } return NULL; } static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ return l2cap_get_service_internal(&l2cap_services, psm); } uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); // check for alread registered psm l2cap_service_t *service = l2cap_get_service(psm); if (service) { log_error("l2cap_register_service: PSM %u already registered", psm); return L2CAP_SERVICE_ALREADY_REGISTERED; } // alloc structure service = btstack_memory_l2cap_service_get(); if (!service) { log_error("l2cap_register_service: no memory for l2cap_service_t"); return BTSTACK_MEMORY_ALLOC_FAILED; } // fill in service->psm = psm; service->mtu = mtu; service->packet_handler = service_packet_handler; service->required_security_level = security_level; // add to services list btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); // enable page scan gap_connectable_control(1); return 0; } uint8_t l2cap_unregister_service(uint16_t psm){ log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); l2cap_service_t *service = l2cap_get_service(psm); if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); btstack_memory_l2cap_service_free(service); // disable page scan when no services registered if (btstack_linked_list_empty(&l2cap_services)) { gap_connectable_control(0); } return 0; } #endif #ifdef ENABLE_LE_DATA_CHANNELS static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ if (!channel->waiting_for_can_send_now) return; if (channel->send_sdu_buffer) return; channel->waiting_for_can_send_now = 0; log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); } // 1BH2222 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { log_info("L2CAP_EVENT_LE_INCOMING_CONNECTION addr_type %u, addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x, remote_mtu %u", channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); uint8_t event[19]; event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; event[1] = sizeof(event) - 2; event[2] = channel->address_type; reverse_bd_addr(channel->address, &event[3]); little_endian_store_16(event, 9, channel->con_handle); little_endian_store_16(event, 11, channel->psm); little_endian_store_16(event, 13, channel->local_cid); little_endian_store_16(event, 15, channel->remote_cid); little_endian_store_16(event, 17, channel->remote_mtu); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); } // 11BH22222 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { log_info("L2CAP_EVENT_LE_CHANNEL_OPENED status 0x%x addr_type %u addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u", status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); uint8_t event[23]; event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; event[1] = sizeof(event) - 2; event[2] = status; event[3] = channel->address_type; reverse_bd_addr(channel->address, &event[4]); little_endian_store_16(event, 10, channel->con_handle); event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; little_endian_store_16(event, 13, channel->psm); little_endian_store_16(event, 15, channel->local_cid); little_endian_store_16(event, 17, channel->remote_cid); little_endian_store_16(event, 19, channel->local_mtu); little_endian_store_16(event, 21, channel->remote_mtu); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); } static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &l2cap_le_channels); while (btstack_linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); if ( channel->local_cid == local_cid) { return channel; } } return NULL; } // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ channel->state = L2CAP_STATE_CLOSED; l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); // discard channel btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); btstack_memory_l2cap_channel_free(channel); } static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ return l2cap_get_service_internal(&l2cap_le_services, le_psm); } uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); // check for alread registered psm l2cap_service_t *service = l2cap_le_get_service(psm); if (service) { return L2CAP_SERVICE_ALREADY_REGISTERED; } // alloc structure service = btstack_memory_l2cap_service_get(); if (!service) { log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); return BTSTACK_MEMORY_ALLOC_FAILED; } // fill in service->psm = psm; service->mtu = 0; service->packet_handler = packet_handler; service->required_security_level = security_level; // add to services list btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); // done return 0; } uint8_t l2cap_le_unregister_service(uint16_t psm) { log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); l2cap_service_t *service = l2cap_le_get_service(psm); if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); btstack_memory_l2cap_service_free(service); return 0; } uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ // get channel l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; // validate state if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ return ERROR_CODE_COMMAND_DISALLOWED; } // set state accept connection channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; channel->receive_sdu_buffer = receive_sdu_buffer; channel->local_mtu = mtu; channel->new_credits_incoming = initial_credits; channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; // test // channel->new_credits_incoming = 1; // go l2cap_run(); return 0; } /** * @brief Deny incoming LE Data Channel connection due to resource constraints * @param local_cid L2CAP LE Data Channel Identifier */ uint8_t l2cap_le_decline_connection(uint16_t local_cid){ // get channel l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; // validate state if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ return ERROR_CODE_COMMAND_DISALLOWED; } // set state decline connection channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; channel->reason = 0x04; // no resources available l2cap_run(); return 0; } uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, uint16_t * out_local_cid) { log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); hci_connection_t * connection = hci_connection_for_handle(con_handle); if (!connection) { log_error("no hci_connection for handle 0x%04x", con_handle); return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; } l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); if (!channel) { return BTSTACK_MEMORY_ALLOC_FAILED; } log_info("l2cap_le_create_channel %p", channel); // store local_cid if (out_local_cid){ *out_local_cid = channel->local_cid; } // provide buffer channel->con_handle = con_handle; channel->receive_sdu_buffer = receive_sdu_buffer; channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; channel->new_credits_incoming = initial_credits; channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; // add to connections list btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); // go l2cap_run(); return 0; } /** * @brief Provide credtis for LE Data Channel * @param local_cid L2CAP LE Data Channel Identifier * @param credits Number additional credits for peer */ uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); if (!channel) { log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); return L2CAP_LOCAL_CID_DOES_NOT_EXIST; } // check state if (channel->state != L2CAP_STATE_OPEN){ log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); } // assert incoming credits + credits <= 0xffff uint32_t total_credits = channel->credits_incoming; total_credits += channel->new_credits_incoming; total_credits += credits; if (total_credits > 0xffff){ log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, channel->new_credits_incoming, credits); } // set credits_granted channel->new_credits_incoming += credits; // go l2cap_run(); return 0; } /** * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module * @param local_cid L2CAP LE Data Channel Identifier */ int l2cap_le_can_send_now(uint16_t local_cid){ l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); if (!channel) { log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); return 0; } // check state if (channel->state != L2CAP_STATE_OPEN) return 0; // check queue if (channel->send_sdu_buffer) return 0; // fine, go ahead return 1; } /** * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function * so packet handler should be ready to handle it * @param local_cid L2CAP LE Data Channel Identifier */ uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); if (!channel) { log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); return 0; } channel->waiting_for_can_send_now = 1; l2cap_le_notify_channel_can_send(channel); return 0; } /** * @brief Send data via LE Data Channel * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event * @param local_cid L2CAP LE Data Channel Identifier * @param data data to send * @param size data size */ uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); if (!channel) { log_error("l2cap_send no channel for cid 0x%02x", local_cid); return L2CAP_LOCAL_CID_DOES_NOT_EXIST; } if (len > channel->remote_mtu){ log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; } if (channel->send_sdu_buffer){ log_info("l2cap_send cid 0x%02x, cannot send", local_cid); return BTSTACK_ACL_BUFFERS_FULL; } channel->send_sdu_buffer = data; channel->send_sdu_len = len; channel->send_sdu_pos = 0; l2cap_run(); return 0; } /** * @brief Disconnect from LE Data Channel * @param local_cid L2CAP LE Data Channel Identifier */ uint8_t l2cap_le_disconnect(uint16_t local_cid) { l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); if (!channel) { log_error("l2cap_send no channel for cid 0x%02x", local_cid); return L2CAP_LOCAL_CID_DOES_NOT_EXIST; } channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; l2cap_run(); return 0; } #endif