M tamaki
mbed base bard check program for BlueTooth USB dongle module (3 switches, 6 leds, I2C LCD, A/D)
Fork of
BTstack
by 
Norimasa Okamoto
Diff: BTstack/l2cap.c
- Revision:
- 0:1ed23ab1345f
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/BTstack/l2cap.c Tue Jun 26 14:27:45 2012 +0000
@@ -0,0 +1,1138 @@
+/*
+ * 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 "l2cap.h"
+#include "hci.h"
+#include "hci_dump.h"
+#include "debug.h"
+#include "btstack_memory.h"
+
+#include <stdarg.h>
+#include <string.h>
+
+#include <stdio.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 = NULL;
+static linked_list_t l2cap_services = NULL;
+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 = NULL;
+static btstack_packet_handler_t security_protocol_packet_handler = NULL;
+
+// 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;
+
+ //
+ // 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[21];
+ 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);
+ 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];
+ 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];
+ 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));
+}
+
+static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){
+ uint8_t event[5];
+ 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) {
+ // track credits
+ channel->packets_granted += credits;
+ // log_info("l2cap_emit_credits for cid %u, credits given: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits);
+
+ uint8_t event[5];
+ 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){
+
+ if (new_credits_blocked) return; // we're told not to. used by daemon
+
+ linked_item_t *it;
+ for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){
+ if (!hci_number_free_acl_slots()) return;
+ l2cap_channel_t * channel = (l2cap_channel_t *) it;
+ 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_item_t *it;
+ for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){
+ l2cap_channel_t * channel = (l2cap_channel_t *) 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_packet_now(HCI_ACL_DATA_PACKET);
+}
+
+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;
+}
+
+int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){
+
+ if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){
+ log_info("l2cap_send_signaling_packet, cannot send\n");
+ return BTSTACK_ACL_BUFFERS_FULL;
+ }
+
+ // log_info("l2cap_send_signaling_packet type %u\n", cmd);
+ uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer();
+ va_list argptr;
+ va_start(argptr, identifier);
+ uint16_t len = l2cap_create_signaling_internal(acl_buffer, handle, cmd, identifier, argptr);
+ va_end(argptr);
+ // log_info("l2cap_send_signaling_packet con %u!\n", handle);
+ return hci_send_acl_packet(acl_buffer, len);
+}
+
+uint8_t *l2cap_get_outgoing_buffer(void){
+ return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes
+}
+
+int l2cap_send_prepared(uint16_t local_cid, uint16_t len){
+
+ if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){
+ log_info("l2cap_send_internal cid %u, cannot send\n", local_cid);
+ return BTSTACK_ACL_BUFFERS_FULL;
+ }
+
+ l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid);
+ if (!channel) {
+ log_error("l2cap_send_internal no channel for cid %u\n", local_cid);
+ return -1; // TODO: define error
+ }
+
+ if (channel->packets_granted == 0){
+ log_error("l2cap_send_internal cid %u, no credits!\n", local_cid);
+ return -1; // TODO: define error
+ }
+
+ --channel->packets_granted;
+
+ log_debug("l2cap_send_internal cid %u, handle %u, 1 credit used, credits left %u;\n",
+ local_cid, channel->handle, channel->packets_granted);
+
+ uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer();
+
+ // 0 - Connection handle : PB=10 : BC=00
+ bt_store_16(acl_buffer, 0, channel->handle | (2 << 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
+ int err = hci_send_acl_packet(acl_buffer, len+8);
+
+ l2cap_hand_out_credits();
+
+ return err;
+}
+
+int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){
+
+ if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){
+ log_info("l2cap_send_prepared_to_handle cid %u, cannot send\n", cid);
+ return BTSTACK_ACL_BUFFERS_FULL;
+ }
+
+ log_debug("l2cap_send_prepared_to_handle cid %u, handle %u\n", cid, handle);
+
+ uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer();
+
+ // 0 - Connection handle : PB=10 : BC=00
+ bt_store_16(acl_buffer, 0, handle | (2 << 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
+ int err = hci_send_acl_packet(acl_buffer, len+8);
+
+ l2cap_hand_out_credits();
+
+ return err;
+}
+
+int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){
+
+ if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){
+ log_info("l2cap_send_internal cid %u, cannot send\n", local_cid);
+ return BTSTACK_ACL_BUFFERS_FULL;
+ }
+
+ uint8_t *acl_buffer = hci_get_outgoing_acl_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){
+
+ if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){
+ log_info("l2cap_send_internal cid %u, cannot send\n", cid);
+ return BTSTACK_ACL_BUFFERS_FULL;
+ }
+
+ uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer();
+
+ memcpy(&acl_buffer[8], data, len);
+
+ return l2cap_send_prepared_connectionless(handle, cid, len);
+}
+
+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){
+
+ // check pending signaling responses
+ while (signaling_responses_pending){
+
+ if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break;
+
+ hci_con_handle_t handle = signaling_responses[0].handle;
+ 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
+
+ switch (signaling_responses[0].code){
+ case CONNECTION_REQUEST:
+ l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0);
+ break;
+ case ECHO_REQUEST:
+ l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL);
+ break;
+ case INFORMATION_REQUEST:
+ if (infoType == 2) {
+ uint32_t features = 0;
+ // extended features request supported, however no features present
+ l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features);
+ } else {
+ // all other types are not supported
+ l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL);
+ }
+ break;
+ default:
+ // should not happen
+ break;
+ }
+
+ // remove first item
+ 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));
+ }
+ }
+
+ uint8_t config_options[4];
+ linked_item_t *it;
+ linked_item_t *next;
+ for (it = (linked_item_t *) l2cap_channels; it ; it = next){
+ next = it->next; // cache next item as current item might get freed
+
+ if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break;
+ if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break;
+
+ l2cap_channel_t * channel = (l2cap_channel_t *) it;
+
+ // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var);
+
+
+ switch (channel->state){
+
+ case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION:
+ // 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:
+ l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, channel->reason, 0);
+ // discard channel - l2cap_finialize_channel_close without sending l2cap close event
+ linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list
+ btstack_memory_l2cap_channel_free(channel);
+ break;
+
+ case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT:
+ 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:
+ // 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);
+ break;
+
+ case L2CAP_STATE_CONFIG:
+ if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){
+ channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP);
+ channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP);
+ l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, 0, 0, 0, NULL);
+ }
+ 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);
+ }
+ 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:
+ l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid);
+ l2cap_finialize_channel_close(channel); // -- remove from list
+ break;
+
+ case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST:
+ 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;
+ }
+ }
+}
+
+uint16_t l2cap_max_mtu(void){
+ return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE;
+}
+
+// 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){
+
+ // alloc structure
+ l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get();
+ if (!chan) {
+ // emit error event
+ l2cap_channel_t dummy_channel;
+ BD_ADDR_COPY(dummy_channel.address, address);
+ dummy_channel.psm = psm;
+ l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED);
+ return;
+ }
+ // limit local mtu to max acl packet length
+ 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;
+
+ // add to connections list
+ linked_list_add(&l2cap_channels, (linked_item_t *) chan);
+
+ l2cap_run();
+}
+
+void l2cap_disconnect_internal(uint16_t local_cid, uint8_t 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){
+ linked_item_t *it = (linked_item_t *) &l2cap_channels;
+ while (it->next){
+ l2cap_channel_t * channel = (l2cap_channel_t *) it->next;
+ if ( ! BD_ADDR_CMP( channel->address, address) ){
+ if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) {
+ // failure, forward error code
+ l2cap_emit_channel_opened(channel, status);
+ // discard channel
+ it->next = it->next->next;
+ btstack_memory_l2cap_channel_free(channel);
+ }
+ } else {
+ it = it->next;
+ }
+ }
+}
+
+static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){
+ linked_item_t *it;
+ for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){
+ l2cap_channel_t * channel = (l2cap_channel_t *) it;
+ if ( ! BD_ADDR_CMP( channel->address, address) ){
+ if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) {
+ // success, start l2cap handshake
+ channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST;
+ channel->handle = handle;
+ channel->local_cid = l2cap_next_local_cid();
+ }
+ }
+ }
+ // process
+ l2cap_run();
+}
+
+void l2cap_event_handler( uint8_t *packet, uint16_t size ){
+
+ bd_addr_t address;
+ hci_con_handle_t handle;
+ l2cap_channel_t * channel;
+ linked_item_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
+ handle = READ_BT_16(packet, 3);
+ it = (linked_item_t *) &l2cap_channels;
+ while (it->next){
+ l2cap_channel_t * channel = (l2cap_channel_t *) it->next;
+ if ( channel->handle == handle ){
+ // update prev item before free'ing next element - don't call l2cap_finalize_channel_close
+ it->next = it->next->next;
+ l2cap_emit_channel_closed(channel);
+ btstack_memory_l2cap_channel_free(channel);
+ } else {
+ it = it->next;
+ }
+ }
+ 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;
+ for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){
+ channel = (l2cap_channel_t *) it;
+ if (channel->handle == handle) {
+ hci_con_used = 1;
+ }
+ }
+ if (hci_con_used) break;
+ if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break;
+ hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection
+ break;
+
+ case DAEMON_EVENT_HCI_PACKET_SENT:
+ for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){
+ channel = (l2cap_channel_t *) it;
+ if (channel->packet_handler) {
+ (* (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;
+
+ default:
+ break;
+ }
+
+ // pass on
+ (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size);
+}
+
+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 %u\n", 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 = connection_for_handle( handle );
+ if (!hci_connection) {
+ //
+ log_error("no hci_connection for handle %u\n", handle);
+ return;
+ }
+ // alloc structure
+ // log_info("l2cap_handle_connection_request register channel\n");
+ l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get();
+ if (!channel){
+ // 0x0004 No resources available
+ l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004);
+ return;
+ }
+
+ // 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;
+
+ // limit local mtu to max acl packet length
+ if (channel->local_mtu > l2cap_max_mtu()) {
+ channel->local_mtu = l2cap_max_mtu();
+ }
+
+ // set initial state
+ channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT;
+ channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE;
+
+ // add to connections list
+ linked_list_add(&l2cap_channels, (linked_item_t *) channel);
+
+ // emit incoming connection request
+ l2cap_emit_connection_request(channel);
+}
+
+void l2cap_accept_connection_internal(uint16_t local_cid){
+ l2cap_channel_t * 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 = 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){
+
+ channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET];
+
+ // accept the other's configuration options
+ uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET);
+ uint16_t pos = 8;
+ while (pos < end_pos){
+ uint8_t type = command[pos++];
+ uint8_t length = command[pos++];
+ // MTU { type(8): 1, len(8):2, MTU(16) }
+ if ((type & 0x7f) == 1 && length == 2){
+ channel->remote_mtu = READ_BT_16(command, pos);
+ // log_info("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu);
+ }
+ pos += length;
+ }
+}
+
+static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){
+ // log_info("l2cap_channel_ready_for_open 0x%02x\n", 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\n", 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:
+ 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
+ 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:
+ switch (code) {
+ case CONFIGURE_REQUEST:
+ channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ);
+ channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP);
+ l2cap_signaling_handle_configure_request(channel, command);
+ break;
+ case CONFIGURE_RESPONSE:
+ channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP);
+ 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\n", 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];
+
+ // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST
+ if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){
+ 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
+ uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET);
+
+ // Find channel for this sig_id and connection handle
+ linked_item_t *it;
+ for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){
+ l2cap_channel_t * channel = (l2cap_channel_t *) it;
+ if (channel->handle == handle) {
+ 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;
+
+ 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;
+ }
+ }
+
+ l2cap_run();
+}
+
+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;
+ }
+}
+
+// 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
+ 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_item_t *it;
+
+ // close open channels
+ for (it = (linked_item_t *) l2cap_services; it ; it = it->next){
+ l2cap_service_t * service = ((l2cap_service_t *) 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){
+ // check for alread registered psm
+ // TODO: emit error event
+ l2cap_service_t *service = l2cap_get_service(psm);
+ if (service) {
+ log_error("l2cap_register_service_internal: PSM %u already registered\n", psm);
+ l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm);
+ return;
+ }
+
+ // alloc structure
+ // TODO: emit error event
+ service = (l2cap_service_t *) btstack_memory_l2cap_service_get();
+ if (!service) {
+ log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n");
+ 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;
+
+ // 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 = 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);
+}
+
+//
+void l2cap_close_connection(void *connection){
+ linked_item_t *it;
+
+ // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks
+ l2cap_channel_t * channel;
+ for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){
+ channel = (l2cap_channel_t *) it;
+ if (channel->connection == connection) {
+ channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST;
+ }
+ }
+
+ // unregister services
+ it = (linked_item_t *) &l2cap_services;
+ while (it->next) {
+ l2cap_service_t * service = (l2cap_service_t *) it->next;
+ if (service->connection == connection){
+ it->next = it->next->next;
+ btstack_memory_l2cap_service_free(service);
+ } else {
+ it = it->next;
+ }
+ }
+
+ // process
+ 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 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;
+ }
+}
+