/* A worker thread that monitors host connections, and registers a transport for
* every new host connection. This thread replaces server_socket_thread on
* condition that adbd daemon runs inside the emulator, and emulator uses QEMUD
* pipe to communicate with adbd daemon inside the guest. This is done in order
* to provide more robust communication channel between ADB host and guest. The
* main issue with server_socket_thread approach is that it runs on top of TCP,
* and thus is sensitive to network disruptions. For instance, the
* ConnectionManager may decide to reset all network connections, in which case
* the connection between ADB host and guest will be lost. To make ADB traffic
* independent from the network, we use here 'adb' QEMUD service to transfer data
* between the host, and the guest. See external/qemu/android/adb-*.* that
* implements the emulator's side of the protocol. Another advantage of using
* QEMUD approach is that ADB will be up much sooner, since it doesn't depend
* anymore on network being set up.
* The guest side of the protocol contains the following phases:
* - Connect with adb QEMUD service. In this phase a handle to 'adb' QEMUD service
* is opened, and it becomes clear whether or not emulator supports that
* protocol.
* - Wait for the ADB host to create connection with the guest. This is done by
* sending an 'accept' request to the adb QEMUD service, and waiting on
* response.
* - When new ADB host connection is accepted, the connection with adb QEMUD
* service is registered as the transport, and a 'start' request is sent to the
* adb QEMUD service, indicating that the guest is ready to receive messages.
* Note that the guest will ignore messages sent down from the emulator before
* the transport registration is completed. That's why we need to send the
* 'start' request after the transport is registered.
*/
static void qemu_socket_thread(void* arg) {
/* 'accept' request to the adb QEMUD service. */
static const char _accept_req[] = "accept";
/* 'start' request to the adb QEMUD service. */
static const char _start_req[] = "start";
/* 'ok' reply from the adb QEMUD service. */
static const char _ok_resp[] = "ok";
const int port = (int) (uintptr_t) arg;
int fd;
char tmp[256];
char con_name[32];
adb_thread_setname("qemu socket");
D("transport: qemu_socket_thread() starting");
/* adb QEMUD service connection request. */
snprintf(con_name, sizeof(con_name), "pipe:qemud:adb:%d", port);
/* Connect to the adb QEMUD service. */
fd = qemu_pipe_open(con_name);
if (fd < 0) {
/* This could be an older version of the emulator, that doesn't
* implement adb QEMUD service. Fall back to the old TCP way. */
D("adb service is not available. Falling back to TCP socket.");
adb_thread_create(server_socket_thread, arg);
return;
}
for(;;) {
/*
* Wait till the host creates a new connection.
*/
/* Send the 'accept' request. */
if (WriteFdExactly(fd, _accept_req, strlen(_accept_req))) {
/* Wait for the response. In the response we expect 'ok' on success,
* or 'ko' on failure. */
if (!ReadFdExactly(fd, tmp, 2) || memcmp(tmp, _ok_resp, 2)) {
D("Accepting ADB host connection has failed.");
adb_close(fd);
} else {
/* Host is connected. Register the transport, and start the
* exchange. */
std::string serial = android::base::StringPrintf("host-%d", fd);
if (register_socket_transport(fd, serial.c_str(), port, 1) != 0 ||
!WriteFdExactly(fd, _start_req, strlen(_start_req))) {
adb_close(fd);
}
}
/* Prepare for accepting of the next ADB host connection. */
fd = qemu_pipe_open(con_name);
if (fd < 0) {
D("adb service become unavailable.");
return;
}
} else {
D("Unable to send the '%s' request to ADB service.", _accept_req);
return;
}
}
D("transport: qemu_socket_thread() exiting");
return;
}
static void transport_registration_func(int _fd, unsigned ev, void *data)
{
tmsg m;
adb_thread_t output_thread_ptr;
adb_thread_t input_thread_ptr;
int s[2];
atransport *t;
if(!(ev & FDE_READ)) {
return;
}
if(transport_read_action(_fd, &m)) {
fatal_errno("cannot read transport registration socket");
}
t = m.transport;
if(m.action == 0){
D("transport: %s removing and free'ing %d\n", t->serial, t->transport_socket);
/* IMPORTANT: the remove closes one half of the
** socket pair. The close closes the other half.
*/
fdevent_remove(&(t->transport_fde));
adb_close(t->fd);
adb_mutex_lock(&transport_lock);
t->next->prev = t->prev;
t->prev->next = t->next;
adb_mutex_unlock(&transport_lock);
run_transport_disconnects(t);
if (t->product)
free(t->product);
if (t->serial)
free(t->serial);
memset(t,0xee,sizeof(atransport));
free(t);
update_transports();
return;
}
/* don't create transport threads for inaccessible devices */
if (t->connection_state != CS_NOPERM) {
/* initial references are the two threads */
t->ref_count = 2;
if(adb_socketpair(s)) {
fatal_errno("cannot open transport socketpair");
}
D("transport: %s (%d,%d) starting\n", t->serial, s[0], s[1]);
t->transport_socket = s[0];
t->fd = s[1];
fdevent_install(&(t->transport_fde),
t->transport_socket,
transport_socket_events,
t);
fdevent_set(&(t->transport_fde), FDE_READ);
if(adb_thread_create(&input_thread_ptr, input_thread, t)){
fatal_errno("cannot create input thread");
}
if(adb_thread_create(&output_thread_ptr, output_thread, t)){
fatal_errno("cannot create output thread");
}
}
/* put us on the master device list */
adb_mutex_lock(&transport_lock);
t->next = &transport_list;
t->prev = transport_list.prev;
t->next->prev = t;
t->prev->next = t;
adb_mutex_unlock(&transport_lock);
t->disconnects.next = t->disconnects.prev = &t->disconnects;
update_transports();
}
static void transport_registration_func(int _fd, unsigned ev, void *data)
{
tmsg m;
int s[2];
atransport *t;
if(!(ev & FDE_READ)) {
return;
}
if(transport_read_action(_fd, &m)) {
fatal_errno("cannot read transport registration socket");
}
t = m.transport;
if (m.action == 0) {
D("transport: %s removing and free'ing %d", t->serial, t->transport_socket);
/* IMPORTANT: the remove closes one half of the
** socket pair. The close closes the other half.
*/
fdevent_remove(&(t->transport_fde));
adb_close(t->fd);
adb_mutex_lock(&transport_lock);
transport_list.remove(t);
adb_mutex_unlock(&transport_lock);
if (t->product)
free(t->product);
if (t->serial)
free(t->serial);
if (t->model)
free(t->model);
if (t->device)
free(t->device);
if (t->devpath)
free(t->devpath);
delete t;
update_transports();
return;
}
/* don't create transport threads for inaccessible devices */
if (t->connection_state != kCsNoPerm) {
/* initial references are the two threads */
t->ref_count = 2;
if (adb_socketpair(s)) {
fatal_errno("cannot open transport socketpair");
}
D("transport: %s socketpair: (%d,%d) starting", t->serial, s[0], s[1]);
t->transport_socket = s[0];
t->fd = s[1];
fdevent_install(&(t->transport_fde),
t->transport_socket,
transport_socket_events,
t);
fdevent_set(&(t->transport_fde), FDE_READ);
if (!adb_thread_create(write_transport_thread, t)) {
fatal_errno("cannot create write_transport thread");
}
if (!adb_thread_create(read_transport_thread, t)) {
fatal_errno("cannot create read_transport thread");
}
}
adb_mutex_lock(&transport_lock);
pending_list.remove(t);
transport_list.push_front(t);
adb_mutex_unlock(&transport_lock);
update_transports();
}
/* A worker thread that monitors host connections, and registers a transport for
* every new host connection. This thread replaces server_socket_thread on
* condition that adbd daemon runs inside the emulator, and emulator uses QEMUD
* pipe to communicate with adbd daemon inside the guest. This is done in order
* to provide more robust communication channel between ADB host and guest. The
* main issue with server_socket_thread approach is that it runs on top of TCP,
* and thus is sensitive to network disruptions. For instance, the
* ConnectionManager may decide to reset all network connections, in which case
* the connection between ADB host and guest will be lost. To make ADB traffic
* independent from the network, we use here 'adb' QEMUD service to transfer data
* between the host, and the guest. See external/qemu/android/adb-*.* that
* implements the emulator's side of the protocol. Another advantage of using
* QEMUD approach is that ADB will be up much sooner, since it doesn't depend
* anymore on network being set up.
* The guest side of the protocol contains the following phases:
* - Connect with adb QEMUD service. In this phase a handle to 'adb' QEMUD service
* is opened, and it becomes clear whether or not emulator supports that
* protocol.
* - Wait for the ADB host to create connection with the guest. This is done by
* sending an 'accept' request to the adb QEMUD service, and waiting on
* response.
* - When new ADB host connection is accepted, the connection with adb QEMUD
* service is registered as the transport, and a 'start' request is sent to the
* adb QEMUD service, indicating that the guest is ready to receive messages.
* Note that the guest will ignore messages sent down from the emulator before
* the transport registration is completed. That's why we need to send the
* 'start' request after the transport is registered.
*/
static void *qemu_socket_thread(void * arg)
{
/* 'accept' request to the adb QEMUD service. */
static const char _accept_req[] = "accept";
/* 'start' request to the adb QEMUD service. */
static const char _start_req[] = "start";
/* 'ok' reply from the adb QEMUD service. */
static const char _ok_resp[] = "ok";
const int port = ((intptr_t)arg);
int res, fd;
char tmp[256];
char con_name[32];
D("transport: qemu_socket_thread() starting\n");
/* adb QEMUD service connection request. */
snprintf(con_name, sizeof(con_name), "qemud:adb:%d", port);
/* Connect to the adb QEMUD service. */
fd = qemu_pipe_open(con_name);
if (fd < 0) {
/* This could be an older version of the emulator, that doesn't
* implement adb QEMUD service. Fall back to the old TCP way. */
adb_thread_t thr;
D("adb service is not available. Falling back to TCP socket.\n");
adb_thread_create(&thr, server_socket_thread, arg);
return 0;
}
for(;;) {
/*
* Wait till the host creates a new connection.
*/
/* Send the 'accept' request. */
res = adb_write(fd, _accept_req, strlen(_accept_req));
if (res == (int)strlen(_accept_req)) {
/* Wait for the response. In the response we expect 'ok' on success,
* or 'ko' on failure. */
res = adb_read(fd, tmp, sizeof(tmp));
if (res != 2 || memcmp(tmp, _ok_resp, 2)) {
D("Accepting ADB host connection has failed.\n");
adb_close(fd);
} else {
/* Host is connected. Register the transport, and start the
* exchange. */
register_socket_transport(fd, "host", port, 1);
adb_write(fd, _start_req, strlen(_start_req));
}
/* Prepare for accepting of the next ADB host connection. */
fd = qemu_pipe_open(con_name);
if (fd < 0) {
D("adb service become unavailable.\n");
return 0;
}
} else {
D("Unable to send the '%s' request to ADB service.\n", _accept_req);
return 0;
}
}
D("transport: qemu_socket_thread() exiting\n");
return 0;
}
void reconnect_device(reconnector *recon)
{
recon->reconnect_bail = 0;
D("creating reconnect thread\n");
adb_thread_create(&recon->reconnect_thread, reconnect_thread, recon);
}