/* * Copyright (C) 2009-2012 by Matthias Ringwald * * 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 MATTHIAS RINGWALD 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 btstack@ringwald.ch * */ /* * l2cap.c * * Logical Link Control and Adaption Protocl (L2CAP) * * Created by Matthias Ringwald on 5/16/09. */ #include #include #include #include "l2cap.h" #include "hci.h" #include "hci_dump.h" #include "debug.h" #include "btstack_memory.h" // 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 // 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 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); // 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*/ linked_list_t l2cap_channels; /*static*/ linked_list_t l2cap_services; static void (*packet_handler) (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) = null_packet_handler; static int new_credits_blocked = 0; static btstack_packet_handler_t attribute_protocol_packet_handler; static btstack_packet_handler_t security_protocol_packet_handler; static uint8_t require_security_level2_for_outgoing_sdp; // prototypes static void l2cap_finialize_channel_close(l2cap_channel_t *channel); static 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_connection_request(l2cap_channel_t *channel); static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); void l2cap_init(){ new_credits_blocked = 0; signaling_responses_pending = 0; l2cap_channels = NULL; l2cap_services = NULL; packet_handler = null_packet_handler; attribute_protocol_packet_handler = NULL; security_protocol_packet_handler = NULL; require_security_level2_for_outgoing_sdp = 0; // // register callback with HCI // hci_register_packet_handler(&l2cap_packet_handler); hci_connectable_control(0); // no services yet } /** Register L2CAP packet handlers */ static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ } void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ packet_handler = handler; } // notify client/protocol handler void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ if (channel->packet_handler) { (* (channel->packet_handler))(type, channel->local_cid, data, size); } else { (*packet_handler)(channel->connection, type, channel->local_cid, data, size); } } void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { uint8_t event[23]; 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->handle, channel->psm, channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); event[0] = L2CAP_EVENT_CHANNEL_OPENED; event[1] = sizeof(event) - 2; event[2] = status; bt_flip_addr(&event[3], channel->address); bt_store_16(event, 9, channel->handle); bt_store_16(event, 11, channel->psm); bt_store_16(event, 13, channel->local_cid); bt_store_16(event, 15, channel->remote_cid); bt_store_16(event, 17, channel->local_mtu); bt_store_16(event, 19, channel->remote_mtu); bt_store_16(event, 21, channel->flush_timeout); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); } void l2cap_emit_channel_closed(l2cap_channel_t *channel) { uint8_t event[4]; log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); event[0] = L2CAP_EVENT_CHANNEL_CLOSED; event[1] = sizeof(event) - 2; bt_store_16(event, 2, channel->local_cid); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); } void l2cap_emit_connection_request(l2cap_channel_t *channel) { uint8_t event[16]; 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->handle, channel->psm, channel->local_cid, channel->remote_cid); event[0] = L2CAP_EVENT_INCOMING_CONNECTION; event[1] = sizeof(event) - 2; bt_flip_addr(&event[2], channel->address); bt_store_16(event, 8, channel->handle); bt_store_16(event, 10, channel->psm); bt_store_16(event, 12, channel->local_cid); bt_store_16(event, 14, channel->remote_cid); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); } void l2cap_emit_connection_parameter_update_response(uint16_t handle, uint16_t result){ uint8_t event[6]; event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; event[1] = 4; bt_store_16(event, 2, handle); bt_store_16(event, 4, result); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, event, sizeof(event)); } static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ uint8_t event[5]; log_info("L2CAP_EVENT_SERVICE_REGISTERED status 0x%x psm 0x%x", status, psm); event[0] = L2CAP_EVENT_SERVICE_REGISTERED; event[1] = sizeof(event) - 2; event[2] = status; bt_store_16(event, 3, psm); hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); } void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { uint8_t event[5]; log_info("L2CAP_EVENT_CREDITS local_cid 0x%x credits %u", channel->local_cid, credits); // track credits channel->packets_granted += credits; event[0] = L2CAP_EVENT_CREDITS; event[1] = sizeof(event) - 2; bt_store_16(event, 2, channel->local_cid); event[4] = credits; hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); } void l2cap_block_new_credits(uint8_t blocked){ new_credits_blocked = blocked; } void l2cap_hand_out_credits(void){ linked_list_iterator_t it; if (new_credits_blocked) return; // we're told not to. used by daemon linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); if (!hci_number_free_acl_slots_for_handle(channel->handle)) return; if (channel->state != L2CAP_STATE_OPEN) continue; if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { l2cap_emit_credits(channel, 1); } } } l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ linked_list_iterator_t it; linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); if ( channel->local_cid == local_cid) { return channel; } } return NULL; } 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; if (!channel->packets_granted) return 0; return hci_can_send_acl_packet_now(channel->handle); } // @deprecated int l2cap_can_send_connectionless_packet_now(void){ // TODO provide real handle return l2cap_can_send_fixed_channel_packet_now(0x1234); } int l2cap_can_send_fixed_channel_packet_now(uint16_t handle){ return hci_can_send_acl_packet_now(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(timer_source_t * ts){ linked_list_iterator_t it; linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); if ( &channel->rtx == ts) { return channel; } } return NULL; } static void l2cap_rtx_timeout(timer_source_t * ts){ l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); if (!ts) 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 linked_list_remove(&l2cap_channels, (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); 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); run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 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); run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); run_loop_add_timer(&channel->rtx); } void l2cap_require_security_level_2_for_outgoing_sdp(){ 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); } int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ uint8_t *acl_buffer; va_list argptr; uint16_t len; 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(); acl_buffer = hci_get_outgoing_packet_buffer(); va_start(argptr, identifier); 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); } #ifdef HAVE_BLE 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_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_le(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); } #endif 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(); } int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ l2cap_channel_t * channel; uint8_t *acl_buffer; int pb; int err; if (!hci_is_packet_buffer_reserved()){ log_error("l2cap_send_prepared called without reserving packet first"); return BTSTACK_ACL_BUFFERS_FULL; } 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 (channel->packets_granted == 0){ log_error("l2cap_send_prepared cid 0x%02x, no credits!", local_cid); return -1; // TODO: define error } if (!hci_can_send_prepared_acl_packet_now(channel->handle)){ log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); return BTSTACK_ACL_BUFFERS_FULL; } --channel->packets_granted; log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used, credits left %u;", local_cid, channel->handle, channel->packets_granted); acl_buffer = hci_get_outgoing_packet_buffer(); pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; // 0 - Connection handle : PB=pb : BC=00 bt_store_16(acl_buffer, 0, channel->handle | (pb << 12) | (0 << 14)); // 2 - ACL length bt_store_16(acl_buffer, 2, len + 4); // 4 - L2CAP packet length bt_store_16(acl_buffer, 4, len + 0); // 6 - L2CAP channel DEST bt_store_16(acl_buffer, 6, channel->remote_cid); // send err = hci_send_acl_packet_buffer(len+8); l2cap_hand_out_credits(); return err; } int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ uint8_t *acl_buffer; int pb; int err; 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(handle)){ log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", handle, cid); return BTSTACK_ACL_BUFFERS_FULL; } log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", handle, cid); acl_buffer = hci_get_outgoing_packet_buffer(); pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; // 0 - Connection handle : PB=pb : BC=00 bt_store_16(acl_buffer, 0, handle | (pb << 12) | (0 << 14)); // 2 - ACL length bt_store_16(acl_buffer, 2, len + 4); // 4 - L2CAP packet length bt_store_16(acl_buffer, 4, len + 0); // 6 - L2CAP channel DEST bt_store_16(acl_buffer, 6, cid); // send err = hci_send_acl_packet_buffer(len+8); l2cap_hand_out_credits(); return err; } int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); uint8_t *acl_buffer; if (!channel) { log_error("l2cap_send_internal no channel for cid 0x%02x", local_cid); return -1; // TODO: define error } if (len > channel->remote_mtu){ log_error("l2cap_send_internal 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->handle)){ log_info("l2cap_send_internal cid 0x%02x, cannot send", local_cid); return BTSTACK_ACL_BUFFERS_FULL; } hci_reserve_packet_buffer(); acl_buffer = hci_get_outgoing_packet_buffer(); memcpy(&acl_buffer[8], data, len); return l2cap_send_prepared(local_cid, len); } int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ uint8_t *acl_buffer; if (!hci_can_send_acl_packet_now(handle)){ log_info("l2cap_send_internal cid 0x%02x, cannot send", cid); return BTSTACK_ACL_BUFFERS_FULL; } hci_reserve_packet_buffer(); acl_buffer = hci_get_outgoing_packet_buffer(); memcpy(&acl_buffer[8], data, len); return l2cap_send_prepared_connectionless(handle, cid, len); } int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ return l2cap_send_signaling_packet(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); } // MARK: L2CAP_RUN // process outstanding signaling tasks void l2cap_run(void){ uint8_t config_options[4]; linked_list_iterator_t it; // check pending signaling responses while (signaling_responses_pending){ hci_con_handle_t handle = signaling_responses[0].handle; uint8_t sig_id; uint16_t infoType; uint16_t result; uint8_t response_code; int i; if (!hci_can_send_acl_packet_now(handle)) break; sig_id = signaling_responses[0].sig_id; infoType = signaling_responses[0].data; // INFORMATION_REQUEST result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT response_code = signaling_responses[0].code; // remove first item before sending (to avoid sending response mutliple times) signaling_responses_pending--; for (i=0; i < signaling_responses_pending; i++){ memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); } switch (response_code){ 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, only supporing fixed channel map uint32_t features = 0x80; 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] = 0x01; // L2CAP Signaling Channel 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); #ifdef HAVE_BLE case COMMAND_REJECT_LE: l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); break; #endif default: // should not happen break; } } linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); // log_info("l2cap_run: state %u, var 0x%02x", 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->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->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->handle)) break; l2cap_send_signaling_packet(channel->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); 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->handle)) break; channel->state = L2CAP_STATE_CONFIG; channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); l2cap_send_signaling_packet(channel->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->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->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->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->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 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); l2cap_send_signaling_packet(channel->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->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 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); l2cap_send_signaling_packet(channel->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 l2cap_emit_credits(channel, 1); } break; case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: if (!hci_can_send_acl_packet_now(channel->handle)) break; l2cap_send_signaling_packet( channel->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->handle)) break; channel->local_sig_id = l2cap_next_sig_id(); channel->state = L2CAP_STATE_WAIT_DISCONNECT; l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); break; default: break; } } #ifdef HAVE_BLE // send l2cap con paramter update if necessary hci_connections_get_iterator(&it); while(linked_list_iterator_has_next(&it)){ hci_connection_t * connection = (hci_connection_t *) linked_list_iterator_next(&it); int result; switch (connection->le_con_parameter_update_state){ case CON_PARAMETER_UPDATE_SEND_RESPONSE: result = 0; break; case CON_PARAMETER_UPDATE_DENY: result = 1; break; default: result = -1; break; } if (result < 0) break; if (!hci_can_send_acl_packet_now(connection->con_handle)) break; hci_reserve_packet_buffer(); uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; uint16_t len = l2cap_le_create_connection_parameter_update_response(acl_buffer, connection->con_handle, 0); 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(){ return l2cap_max_mtu(); } static void l2cap_handle_connection_complete(uint16_t 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->handle = handle; channel->local_cid = l2cap_next_local_cid(); // 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 (hci_ssp_supported_on_both_sides(channel->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->handle, LEVEL_2); return; } // fine, go ahead channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; } // open outgoing L2CAP channel void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, uint16_t mtu){ l2cap_channel_t * chan; hci_connection_t * conn; log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); // alloc structure chan = btstack_memory_l2cap_channel_get(); if (!chan) { // emit error event l2cap_channel_t dummy_channel; memset(&dummy_channel, 0, sizeof(dummy_channel)); BD_ADDR_COPY(dummy_channel.address, address); dummy_channel.psm = psm; l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); return; } // Init memory (make valgrind happy) memset(chan, 0, sizeof(l2cap_channel_t)); // limit local mtu to max acl packet length - l2cap header if (mtu > l2cap_max_mtu()) { mtu = l2cap_max_mtu(); } // fill in BD_ADDR_COPY(chan->address, address); chan->psm = psm; chan->handle = 0; chan->connection = connection; chan->packet_handler = packet_handler; chan->remote_mtu = L2CAP_MINIMAL_MTU; chan->local_mtu = mtu; chan->packets_granted = 0; // set initial state chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; chan->remote_sig_id = L2CAP_SIG_ID_INVALID; chan->local_sig_id = L2CAP_SIG_ID_INVALID; chan->required_security_level = LEVEL_0; // add to connections list linked_list_add(&l2cap_channels, (linked_item_t *) chan); // check if hci connection is already usable conn = hci_connection_for_bd_addr_and_type((bd_addr_t*)address, BD_ADDR_TYPE_CLASSIC); if (conn){ log_info("l2cap_create_channel_internal, hci connection already exists"); l2cap_handle_connection_complete(conn->con_handle, chan); // check ir remote supported fearures are already received if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { l2cap_handle_remote_supported_features_received(chan); } } l2cap_run(); } void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ l2cap_channel_t * channel; log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); // find channel for local_cid 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){ linked_list_iterator_t it; linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) 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); 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){ linked_list_iterator_t it; linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); if ( ! BD_ADDR_CMP( channel->address, address) ){ l2cap_handle_connection_complete(handle, channel); } } // process l2cap_run(); } void l2cap_event_handler(uint8_t *packet, uint16_t size){ bd_addr_t address; hci_con_handle_t handle; linked_list_iterator_t it; int hci_con_used; switch(packet[0]){ // handle connection complete events case HCI_EVENT_CONNECTION_COMPLETE: bt_flip_addr(address, &packet[5]); if (packet[2] == 0){ handle = READ_BT_16(packet, 3); l2cap_handle_connection_success_for_addr(address, handle); } else { l2cap_handle_connection_failed_for_addr(address, packet[2]); } break; // handle successful create connection cancel command case HCI_EVENT_COMMAND_COMPLETE: if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { if (packet[5] == 0){ bt_flip_addr(address, &packet[6]); // CONNECTION TERMINATED BY LOCAL HOST (0X16) l2cap_handle_connection_failed_for_addr(address, 0x16); } } l2cap_run(); // try sending signaling packets first break; case HCI_EVENT_COMMAND_STATUS: l2cap_run(); // try sending signaling packets first break; // handle disconnection complete events case HCI_EVENT_DISCONNECTION_COMPLETE: // send l2cap disconnect events for all channels on this handle and free them handle = READ_BT_16(packet, 3); linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); if (channel->handle != handle) continue; l2cap_emit_channel_closed(channel); l2cap_stop_rtx(channel); linked_list_iterator_remove(&it); btstack_memory_l2cap_channel_free(channel); } break; case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: l2cap_run(); // try sending signaling packets first l2cap_hand_out_credits(); break; // HCI Connection Timeouts case L2CAP_EVENT_TIMEOUT_CHECK: handle = READ_BT_16(packet, 2); if (hci_authentication_active_for_handle(handle)) break; hci_con_used = 0; linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); if (channel->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 DAEMON_EVENT_HCI_PACKET_SENT: linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); if (!channel->packet_handler) continue; (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); } if (attribute_protocol_packet_handler) { (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); } if (security_protocol_packet_handler) { (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); } break; case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: handle = READ_BT_16(packet, 3); linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); if (channel->handle != handle) continue; l2cap_handle_remote_supported_features_received(channel); break; } break; case GAP_SECURITY_LEVEL: handle = READ_BT_16(packet, 2); log_info("l2cap - security level update"); linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); gap_security_level_t actual_level; gap_security_level_t required_level; if (channel->handle != handle) continue; log_info("l2cap - state %u", channel->state); actual_level = packet[4]; 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_connection_request(channel); } else { channel->reason = 0x03; // 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; default: break; } // pass on: main packet handler, att and sm packet handlers (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); if (attribute_protocol_packet_handler){ (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); } if (security_protocol_packet_handler) { (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); } l2cap_run(); } 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_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(); } } 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); hci_connection_t * hci_connection; l2cap_channel_t * channel; if (!service) { // 0x0002 PSM not supported l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); return; } hci_connection = hci_connection_for_handle( handle ); if (!hci_connection) { // log_error("no hci_connection for handle %u", handle); return; } // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP if ( hci_ssp_supported_on_both_sides(handle) && gap_security_level(handle) == LEVEL_0 && !l2cap_security_level_0_allowed_for_PSM(psm)){ // 0x0003 Security Block l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); return; } // alloc structure // log_info("l2cap_handle_connection_request register channel"); channel = btstack_memory_l2cap_channel_get(); if (!channel){ // 0x0004 No resources available l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); return; } // Init memory (make valgrind happy) memset(channel, 0, sizeof(l2cap_channel_t)); // fill in BD_ADDR_COPY(channel->address, hci_connection->address); channel->psm = psm; channel->handle = handle; channel->connection = service->connection; channel->packet_handler = service->packet_handler; channel->local_cid = l2cap_next_local_cid(); channel->remote_cid = source_cid; channel->local_mtu = service->mtu; channel->remote_mtu = L2CAP_DEFAULT_MTU; channel->packets_granted = 0; channel->remote_sig_id = sig_id; channel->required_security_level = service->required_security_level; // 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_SEND_CONN_RESP_PEND; // add to connections list linked_list_add(&l2cap_channels, (linked_item_t *) channel); // assert security requirements gap_request_security_level(handle, channel->required_security_level); } void l2cap_accept_connection_internal(uint16_t local_cid){ l2cap_channel_t * channel; log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); channel = l2cap_get_channel_for_local_cid(local_cid); if (!channel) { log_error("l2cap_accept_connection_internal 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_internal(uint16_t local_cid, uint8_t reason){ l2cap_channel_t * channel; log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); channel = l2cap_get_channel_for_local_cid( local_cid); if (!channel) { log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); return; } channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; channel->reason = reason; l2cap_run(); } void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ uint16_t flags; uint16_t end_pos; uint16_t pos; channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; flags = READ_BT_16(command, 6); if (flags & 1) { channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); } // accept the other's configuration options end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); pos = 8; while (pos < end_pos){ uint8_t option_hint = command[pos] >> 7; uint8_t option_type = command[pos] & 0x7f; uint8_t length; log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); pos++; length = command[pos++]; // MTU { type(8): 1, len(8):2, MTU(16) } if (option_type == 1 && length == 2){ channel->remote_mtu = READ_BT_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 = READ_BT_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; return 1; } 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 = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); switch (result) { case 0: // successful connection channel->remote_cid = READ_BT_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){ hci_drop_link_key_for_bd_addr(&channel->address); } // discard channel linked_list_remove(&l2cap_channels, (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 = READ_BT_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); l2cap_emit_credits(channel, 1); } 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); } 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]; uint16_t dest_cid; linked_list_iterator_t it; // 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 = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); uint16_t source_cid = READ_BT_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 = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); l2cap_register_signaling_response(handle, code, sig_id, infoType); return; } default: break; } // Get potential destination CID dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); // Find channel for this sig_id and connection handle linked_list_iterator_init(&it, &l2cap_channels); while (linked_list_iterator_has_next(&it)){ l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); if (channel->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; } } } } void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ // 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) { 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 + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); } break; } case L2CAP_CID_ATTRIBUTE_PROTOCOL: if (attribute_protocol_packet_handler) { (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); } break; case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: if (security_protocol_packet_handler) { (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); } break; case L2CAP_CID_SIGNALING_LE: { switch (packet[8]){ case CONNECTION_PARAMETER_UPDATE_RESPONSE: { uint16_t result = READ_BT_16(packet, 12); l2cap_emit_connection_parameter_update_response(handle, result); break; } case CONNECTION_PARAMETER_UPDATE_REQUEST: { uint8_t event[10]; hci_connection_t * connection; event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; event[1] = 8; memcpy(&event[2], &packet[12], 8); connection = hci_connection_for_handle(handle); if (connection){ int update_parameter = 1; le_connection_parameter_range_t existing_range = gap_le_get_connection_parameter_range(); uint16_t le_conn_interval_min = READ_BT_16(packet,12); uint16_t le_conn_interval_max = READ_BT_16(packet,14); uint16_t le_conn_latency = READ_BT_16(packet,16); uint16_t le_supervision_timeout = READ_BT_16(packet,18); 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; } } hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, event, sizeof(event)); break; } default: { uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); break; } } break; } default: { // Find channel for this channel_id and connection handle l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); if (channel) { l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); } break; } } } static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ switch (packet_type) { case HCI_EVENT_PACKET: l2cap_event_handler(packet, size); break; case HCI_ACL_DATA_PACKET: l2cap_acl_handler(packet, size); break; default: break; } l2cap_run(); } // 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); linked_list_remove(&l2cap_channels, (linked_item_t *) channel); btstack_memory_l2cap_channel_free(channel); } l2cap_service_t * l2cap_get_service(uint16_t psm){ linked_list_iterator_t it; linked_list_iterator_init(&it, &l2cap_services); while (linked_list_iterator_has_next(&it)){ l2cap_service_t * service = (l2cap_service_t *) linked_list_iterator_next(&it); if ( service->psm == psm){ return service; }; } return NULL; } void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ l2cap_service_t *service; log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u connection %p", psm, mtu, connection); // check for alread registered psm // TODO: emit error event service = l2cap_get_service(psm); if (service) { log_error("l2cap_register_service_internal: PSM %u already registered", psm); l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); return; } // alloc structure // TODO: emit error event service = btstack_memory_l2cap_service_get(); if (!service) { log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); return; } // fill in service->psm = psm; service->mtu = mtu; service->connection = connection; service->packet_handler = packet_handler; service->required_security_level = security_level; // add to services list linked_list_add(&l2cap_services, (linked_item_t *) service); // enable page scan hci_connectable_control(1); // done l2cap_emit_service_registered(connection, 0, psm); } void l2cap_unregister_service_internal(void *connection, uint16_t psm){ l2cap_service_t *service; log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); service = l2cap_get_service(psm); if (!service) return; linked_list_remove(&l2cap_services, (linked_item_t *) service); btstack_memory_l2cap_service_free(service); // disable page scan when no services registered if (!linked_list_empty(&l2cap_services)) return; hci_connectable_control(0); } // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { switch(channel_id){ case L2CAP_CID_ATTRIBUTE_PROTOCOL: attribute_protocol_packet_handler = packet_handler; break; case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: security_protocol_packet_handler = packet_handler; break; } } #ifdef HAVE_BLE // Request LE connection parameter update int l2cap_le_request_connection_parameter_update(uint16_t handle, uint16_t interval_min, uint16_t interval_max, uint16_t slave_latency, uint16_t timeout_multiplier){ 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(); uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); return hci_send_acl_packet_buffer(len); } #endif