blob: 9608e117fa57bf43361b940984b4e4a366700c51 [file] [log] [blame]
/******************************************************************************
*
* Copyright (C) 2014 Google, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************/
#define LOG_TAG "btif_sock_sco"
#include <assert.h>
#include <hardware/bluetooth.h>
#include <hardware/bt_sock.h>
#include <sys/socket.h>
#include <sys/types.h>
#include "btif_common.h"
#include "list.h"
#include "osi.h"
#include "osi/include/log.h"
#include "socket.h"
#include "thread.h"
// This module provides a socket abstraction for SCO connections to a higher
// layer. It returns file descriptors representing two types of sockets:
// listening (server) and connected (client) sockets. No SCO data is
// transferred across these sockets; instead, they are used to manage SCO
// connection lifecycles while the data routing takes place over the I2S bus.
//
// This code bridges the gap between the BTM layer, which implements SCO
// connections, and the Android HAL. It adapts the BTM representation of SCO
// connections (integer handles) to a file descriptor representation usable by
// Android's LocalSocket implementation.
//
// Sample flow for an incoming connection:
// btsock_sco_listen() - listen for incoming connections
// connection_request_cb() - incoming connection request from remote host
// connect_completed_cb() - connection successfully established
// socket_read_ready_cb() - local host closed SCO socket
// disconnect_completed_cb() - connection terminated
typedef struct {
uint16_t sco_handle;
socket_t *socket;
bool connect_completed;
} sco_socket_t;
// TODO: verify packet types that are being sent OTA.
static tBTM_ESCO_PARAMS sco_parameters = {
BTM_64KBITS_RATE, /* TX Bandwidth (64 kbits/sec) */
BTM_64KBITS_RATE, /* RX Bandwidth (64 kbits/sec) */
0x000a, /* 10 ms (HS/HF can use EV3, 2-EV3, 3-EV3) */
0x0060, /* Inp Linear, Air CVSD, 2s Comp, 16bit */
(BTM_SCO_LINK_ALL_PKT_MASK |
BTM_SCO_PKT_TYPES_MASK_NO_2_EV5 |
BTM_SCO_PKT_TYPES_MASK_NO_3_EV5),
BTM_ESCO_RETRANS_POWER /* Retransmission effort */
};
static sco_socket_t *sco_socket_establish_locked(bool is_listening, const bt_bdaddr_t *bd_addr, int *sock_fd);
static sco_socket_t *sco_socket_new(void);
static void sco_socket_free_locked(sco_socket_t *socket);
static sco_socket_t *sco_socket_find_locked(uint16_t sco_handle);
static void connection_request_cb(tBTM_ESCO_EVT event, tBTM_ESCO_EVT_DATA *data);
static void connect_completed_cb(uint16_t sco_handle);
static void disconnect_completed_cb(uint16_t sco_handle);
static void socket_read_ready_cb(socket_t *socket, void *context);
// |lock| protects all of the static variables below and
// calls into the BTM layer.
static pthread_mutex_t lock;
static list_t *sco_sockets; // Owns a collection of sco_socket_t objects.
static sco_socket_t *listen_sco_socket; // Not owned, do not free.
static thread_t *thread; // Not owned, do not free.
bt_status_t btsock_sco_init(thread_t *thread_) {
assert(thread_ != NULL);
sco_sockets = list_new((list_free_cb)sco_socket_free_locked);
if (!sco_sockets)
return BT_STATUS_FAIL;
pthread_mutex_init(&lock, NULL);
thread = thread_;
BTM_SetEScoMode(BTM_LINK_TYPE_ESCO, &sco_parameters);
return BT_STATUS_SUCCESS;
}
bt_status_t btsock_sco_cleanup(void) {
list_free(sco_sockets);
sco_sockets = NULL;
pthread_mutex_destroy(&lock);
return BT_STATUS_SUCCESS;
}
bt_status_t btsock_sco_listen(int *sock_fd, UNUSED_ATTR int flags) {
assert(sock_fd != NULL);
pthread_mutex_lock(&lock);
sco_socket_t *sco_socket = sco_socket_establish_locked(true, NULL, sock_fd);
if (sco_socket) {
BTM_RegForEScoEvts(sco_socket->sco_handle, connection_request_cb);
listen_sco_socket = sco_socket;
}
pthread_mutex_unlock(&lock);
return sco_socket ? BT_STATUS_SUCCESS : BT_STATUS_FAIL;
}
bt_status_t btsock_sco_connect(const bt_bdaddr_t *bd_addr, int *sock_fd, UNUSED_ATTR int flags) {
assert(bd_addr != NULL);
assert(sock_fd != NULL);
pthread_mutex_lock(&lock);
sco_socket_t *sco_socket = sco_socket_establish_locked(false, bd_addr, sock_fd);
pthread_mutex_unlock(&lock);
return (sco_socket != NULL) ? BT_STATUS_SUCCESS : BT_STATUS_FAIL;
}
// Must be called with |lock| held.
static sco_socket_t *sco_socket_establish_locked(bool is_listening, const bt_bdaddr_t *bd_addr, int *sock_fd) {
int pair[2] = { INVALID_FD, INVALID_FD };
sco_socket_t *sco_socket = NULL;
if (socketpair(AF_LOCAL, SOCK_STREAM, 0, pair) == -1) {
LOG_ERROR("%s unable to allocate socket pair: %s", __func__, strerror(errno));
goto error;
}
sco_socket = sco_socket_new();
if (!sco_socket) {
LOG_ERROR("%s unable to allocate new SCO socket.", __func__);
goto error;
}
tBTM_STATUS status = BTM_CreateSco((uint8_t *)bd_addr, !is_listening, sco_parameters.packet_types, &sco_socket->sco_handle, connect_completed_cb, disconnect_completed_cb);
if (status != BTM_CMD_STARTED) {
LOG_ERROR("%s unable to create SCO socket: %d", __func__, status);
goto error;
}
socket_t *socket = socket_new_from_fd(pair[1]);
if (!socket) {
LOG_ERROR("%s unable to allocate socket from file descriptor %d.", __func__, pair[1]);
goto error;
}
*sock_fd = pair[0]; // Transfer ownership of one end to caller.
sco_socket->socket = socket; // Hang on to the other end.
list_append(sco_sockets, sco_socket);
socket_register(socket, thread_get_reactor(thread), sco_socket, socket_read_ready_cb, NULL);
return sco_socket;
error:;
if (pair[0] != INVALID_FD)
close(pair[0]);
if (pair[1] != INVALID_FD)
close(pair[1]);
sco_socket_free_locked(sco_socket);
return NULL;
}
static sco_socket_t *sco_socket_new(void) {
sco_socket_t *sco_socket = (sco_socket_t *)calloc(1, sizeof(sco_socket_t));
if (sco_socket)
sco_socket->sco_handle = BTM_INVALID_SCO_INDEX;
return sco_socket;
}
// Must be called with |lock| held except during teardown when we know the socket thread
// is no longer alive.
static void sco_socket_free_locked(sco_socket_t *sco_socket) {
if (!sco_socket)
return;
if (sco_socket->sco_handle != BTM_INVALID_SCO_INDEX)
BTM_RemoveSco(sco_socket->sco_handle);
socket_free(sco_socket->socket);
free(sco_socket);
}
// Must be called with |lock| held.
static sco_socket_t *sco_socket_find_locked(uint16_t sco_handle) {
for (const list_node_t *node = list_begin(sco_sockets); node != list_end(sco_sockets); node = list_next(node)) {
sco_socket_t *sco_socket = (sco_socket_t *)list_node(node);
if (sco_socket->sco_handle == sco_handle)
return sco_socket;
}
return NULL;
}
static void connection_request_cb(tBTM_ESCO_EVT event, tBTM_ESCO_EVT_DATA *data) {
assert(data != NULL);
// Don't care about change of link parameters, only connection requests.
if (event != BTM_ESCO_CONN_REQ_EVT)
return;
pthread_mutex_lock(&lock);
const tBTM_ESCO_CONN_REQ_EVT_DATA *conn_data = &data->conn_evt;
sco_socket_t *sco_socket = sco_socket_find_locked(conn_data->sco_inx);
int client_fd = INVALID_FD;
if (!sco_socket) {
LOG_ERROR("%s unable to find sco_socket for handle: %hu", __func__, conn_data->sco_inx);
goto error;
}
if (sco_socket != listen_sco_socket) {
LOG_ERROR("%s received connection request on non-listening socket handle: %hu", __func__, conn_data->sco_inx);
goto error;
}
sco_socket_t *new_sco_socket = sco_socket_establish_locked(true, NULL, &client_fd);
if (!new_sco_socket) {
LOG_ERROR("%s unable to allocate new sco_socket.", __func__);
goto error;
}
// Swap socket->sco_handle and new_socket->sco_handle
uint16_t temp = sco_socket->sco_handle;
sco_socket->sco_handle = new_sco_socket->sco_handle;
new_sco_socket->sco_handle = temp;
sock_connect_signal_t connect_signal;
connect_signal.size = sizeof(connect_signal);
memcpy(&connect_signal.bd_addr, conn_data->bd_addr, sizeof(bt_bdaddr_t));
connect_signal.channel = 0;
connect_signal.status = 0;
if (socket_write_and_transfer_fd(sco_socket->socket, &connect_signal, sizeof(connect_signal), client_fd) != sizeof(connect_signal)) {
LOG_ERROR("%s unable to send new file descriptor to listening socket.", __func__);
goto error;
}
BTM_RegForEScoEvts(listen_sco_socket->sco_handle, connection_request_cb);
BTM_EScoConnRsp(conn_data->sco_inx, HCI_SUCCESS, NULL);
pthread_mutex_unlock(&lock);
return;
error:;
pthread_mutex_unlock(&lock);
if (client_fd != INVALID_FD)
close(client_fd);
BTM_EScoConnRsp(conn_data->sco_inx, HCI_ERR_HOST_REJECT_RESOURCES, NULL);
}
static void connect_completed_cb(uint16_t sco_handle) {
pthread_mutex_lock(&lock);
sco_socket_t *sco_socket = sco_socket_find_locked(sco_handle);
if (!sco_socket) {
LOG_ERROR("%s SCO socket not found on connect for handle: %hu", __func__, sco_handle);
goto out;
}
// If sco_socket->socket was closed, we should tear down because there is no app-level
// interest in the SCO socket.
if (!sco_socket->socket) {
BTM_RemoveSco(sco_socket->sco_handle);
list_remove(sco_sockets, sco_socket);
goto out;
}
sco_socket->connect_completed = true;
out:;
pthread_mutex_unlock(&lock);
}
static void disconnect_completed_cb(uint16_t sco_handle) {
pthread_mutex_lock(&lock);
sco_socket_t *sco_socket = sco_socket_find_locked(sco_handle);
if (!sco_socket) {
LOG_ERROR("%s SCO socket not found on disconnect for handle: %hu", __func__, sco_handle);
goto out;
}
list_remove(sco_sockets, sco_socket);
out:;
pthread_mutex_unlock(&lock);
}
static void socket_read_ready_cb(UNUSED_ATTR socket_t *socket, void *context) {
pthread_mutex_lock(&lock);
sco_socket_t *sco_socket = (sco_socket_t *)context;
socket_free(sco_socket->socket);
sco_socket->socket = NULL;
// Defer the underlying disconnect until the connection completes
// since the BTM code doesn't behave correctly when a disconnect
// request is issued while a connect is in progress. The fact that
// sco_socket->socket == NULL indicates to the connect callback
// routine that the socket is no longer desired and should be torn
// down.
if (sco_socket->connect_completed || sco_socket == listen_sco_socket) {
if (BTM_RemoveSco(sco_socket->sco_handle) == BTM_SUCCESS)
list_remove(sco_sockets, sco_socket);
if (sco_socket == listen_sco_socket)
listen_sco_socket = NULL;
}
pthread_mutex_unlock(&lock);
}