/*
* Copyright (C) 2016 The Android Open Source Project
*
* 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.
*/
#include "usb.h"
#include "sysdeps.h"
#include <stdint.h>
#include <atomic>
#include <chrono>
#include <memory>
#include <mutex>
#include <string>
#include <thread>
#include <unordered_map>
#include <libusb/libusb.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/quick_exit.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include "adb.h"
#include "transport.h"
#include "usb.h"
using namespace std::literals;
using android::base::StringPrintf;
// RAII wrappers for libusb.
struct ConfigDescriptorDeleter {
void operator()(libusb_config_descriptor* desc) {
libusb_free_config_descriptor(desc);
}
};
using unique_config_descriptor = std::unique_ptr<libusb_config_descriptor, ConfigDescriptorDeleter>;
struct DeviceHandleDeleter {
void operator()(libusb_device_handle* h) {
libusb_close(h);
}
};
using unique_device_handle = std::unique_ptr<libusb_device_handle, DeviceHandleDeleter>;
struct transfer_info {
transfer_info(const char* name, uint16_t zero_mask) :
name(name),
transfer(libusb_alloc_transfer(0)),
zero_mask(zero_mask)
{
}
~transfer_info() {
libusb_free_transfer(transfer);
}
const char* name;
libusb_transfer* transfer;
bool transfer_complete;
std::condition_variable cv;
std::mutex mutex;
uint16_t zero_mask;
void Notify() {
LOG(DEBUG) << "notifying " << name << " transfer complete";
transfer_complete = true;
cv.notify_one();
}
};
namespace libusb {
struct usb_handle : public ::usb_handle {
usb_handle(const std::string& device_address, const std::string& serial,
unique_device_handle&& device_handle, uint8_t interface, uint8_t bulk_in,
uint8_t bulk_out, size_t zero_mask)
: device_address(device_address),
serial(serial),
closing(false),
device_handle(device_handle.release()),
read("read", zero_mask),
write("write", zero_mask),
interface(interface),
bulk_in(bulk_in),
bulk_out(bulk_out) {
}
~usb_handle() {
Close();
}
void Close() {
std::unique_lock<std::mutex> lock(device_handle_mutex);
// Cancelling transfers will trigger more Closes, so make sure this only happens once.
if (closing) {
return;
}
closing = true;
// Make sure that no new transfers come in.
libusb_device_handle* handle = device_handle;
if (!handle) {
return;
}
device_handle = nullptr;
// Cancel already dispatched transfers.
libusb_cancel_transfer(read.transfer);
libusb_cancel_transfer(write.transfer);
libusb_release_interface(handle, interface);
libusb_close(handle);
}
std::string device_address;
std::string serial;
std::atomic<bool> closing;
std::mutex device_handle_mutex;
libusb_device_handle* device_handle;
transfer_info read;
transfer_info write;
uint8_t interface;
uint8_t bulk_in;
uint8_t bulk_out;
};
static auto& usb_handles = *new std::unordered_map<std::string, std::unique_ptr<usb_handle>>();
static auto& usb_handles_mutex = *new std::mutex();
static std::thread* device_poll_thread = nullptr;
static std::atomic<bool> terminate_device_poll_thread(false);
static std::string get_device_address(libusb_device* device) {
return StringPrintf("usb:%d:%d", libusb_get_bus_number(device),
libusb_get_device_address(device));
}
static bool endpoint_is_output(uint8_t endpoint) {
return (endpoint & LIBUSB_ENDPOINT_DIR_MASK) == LIBUSB_ENDPOINT_OUT;
}
static bool should_perform_zero_transfer(uint8_t endpoint, size_t write_length, uint16_t zero_mask) {
return endpoint_is_output(endpoint) && write_length != 0 && zero_mask != 0 &&
(write_length & zero_mask) == 0;
}
static void poll_for_devices() {
libusb_device** list;
adb_thread_setname("device poll");
while (!terminate_device_poll_thread) {
const ssize_t device_count = libusb_get_device_list(nullptr, &list);
LOG(VERBOSE) << "found " << device_count << " attached devices";
for (ssize_t i = 0; i < device_count; ++i) {
libusb_device* device = list[i];
std::string device_address = get_device_address(device);
std::string device_serial;
// Figure out if we want to open the device.
libusb_device_descriptor device_desc;
int rc = libusb_get_device_descriptor(device, &device_desc);
if (rc != 0) {
LOG(WARNING) << "failed to get device descriptor for device at " << device_address
<< ": " << libusb_error_name(rc);
}
if (device_desc.bDeviceClass != LIBUSB_CLASS_PER_INTERFACE) {
// Assume that all Android devices have the device class set to per interface.
// TODO: Is this assumption valid?
LOG(VERBOSE) << "skipping device with incorrect class at " << device_address;
continue;
}
libusb_config_descriptor* config_raw;
rc = libusb_get_active_config_descriptor(device, &config_raw);
if (rc != 0) {
LOG(WARNING) << "failed to get active config descriptor for device at "
<< device_address << ": " << libusb_error_name(rc);
continue;
}
const unique_config_descriptor config(config_raw);
// Use size_t for interface_num so <iostream>s don't mangle it.
size_t interface_num;
uint16_t zero_mask;
uint8_t bulk_in = 0, bulk_out = 0;
bool found_adb = false;
for (interface_num = 0; interface_num < config->bNumInterfaces; ++interface_num) {
const libusb_interface& interface = config->interface[interface_num];
if (interface.num_altsetting != 1) {
// Assume that interfaces with alternate settings aren't adb interfaces.
// TODO: Is this assumption valid?
LOG(VERBOSE) << "skipping interface with incorrect num_altsetting at "
<< device_address << " (interface " << interface_num << ")";
continue;
}
const libusb_interface_descriptor& interface_desc = interface.altsetting[0];
if (!is_adb_interface(interface_desc.bInterfaceClass,
interface_desc.bInterfaceSubClass,
interface_desc.bInterfaceProtocol)) {
LOG(VERBOSE) << "skipping non-adb interface at " << device_address
<< " (interface " << interface_num << ")";
continue;
}
LOG(VERBOSE) << "found potential adb interface at " << device_address
<< " (interface " << interface_num << ")";
bool found_in = false;
bool found_out = false;
for (size_t endpoint_num = 0; endpoint_num < interface_desc.bNumEndpoints;
++endpoint_num) {
const auto& endpoint_desc = interface_desc.endpoint[endpoint_num];
const uint8_t endpoint_addr = endpoint_desc.bEndpointAddress;
const uint8_t endpoint_attr = endpoint_desc.bmAttributes;
const uint8_t transfer_type = endpoint_attr & LIBUSB_TRANSFER_TYPE_MASK;
if (transfer_type != LIBUSB_TRANSFER_TYPE_BULK) {
continue;
}
if (endpoint_is_output(endpoint_addr) && !found_out) {
found_out = true;
bulk_out = endpoint_addr;
zero_mask = endpoint_desc.wMaxPacketSize - 1;
} else if (!endpoint_is_output(endpoint_addr) && !found_in) {
found_in = true;
bulk_in = endpoint_addr;
}
}
if (found_in && found_out) {
found_adb = true;
break;
} else {
LOG(VERBOSE) << "rejecting potential adb interface at " << device_address
<< "(interface " << interface_num << "): missing bulk endpoints "
<< "(found_in = " << found_in << ", found_out = " << found_out
<< ")";
}
}
if (!found_adb) {
LOG(VERBOSE) << "skipping device with no adb interfaces at " << device_address;
continue;
}
{
std::unique_lock<std::mutex> lock(usb_handles_mutex);
if (usb_handles.find(device_address) != usb_handles.end()) {
LOG(VERBOSE) << "device at " << device_address
<< " has already been registered, skipping";
continue;
}
}
libusb_device_handle* handle_raw;
rc = libusb_open(list[i], &handle_raw);
if (rc != 0) {
LOG(WARNING) << "failed to open usb device at " << device_address << ": "
<< libusb_error_name(rc);
continue;
}
unique_device_handle handle(handle_raw);
LOG(DEBUG) << "successfully opened adb device at " << device_address << ", "
<< StringPrintf("bulk_in = %#x, bulk_out = %#x", bulk_in, bulk_out);
device_serial.resize(255);
rc = libusb_get_string_descriptor_ascii(
handle_raw, device_desc.iSerialNumber,
reinterpret_cast<unsigned char*>(&device_serial[0]), device_serial.length());
if (rc == 0) {
LOG(WARNING) << "received empty serial from device at " << device_address;
continue;
} else if (rc < 0) {
LOG(WARNING) << "failed to get serial from device at " << device_address
<< libusb_error_name(rc);
continue;
}
device_serial.resize(rc);
// Try to reset the device.
rc = libusb_reset_device(handle_raw);
if (rc != 0) {
LOG(WARNING) << "failed to reset opened device '" << device_serial
<< "': " << libusb_error_name(rc);
continue;
}
// WARNING: this isn't released via RAII.
rc = libusb_claim_interface(handle.get(), interface_num);
if (rc != 0) {
LOG(WARNING) << "failed to claim adb interface for device '" << device_serial << "'"
<< libusb_error_name(rc);
continue;
}
for (uint8_t endpoint : {bulk_in, bulk_out}) {
rc = libusb_clear_halt(handle.get(), endpoint);
if (rc != 0) {
LOG(WARNING) << "failed to clear halt on device '" << device_serial
<< "' endpoint 0x" << std::hex << endpoint << ": "
<< libusb_error_name(rc);
libusb_release_interface(handle.get(), interface_num);
continue;
}
}
auto result =
std::make_unique<usb_handle>(device_address, device_serial, std::move(handle),
interface_num, bulk_in, bulk_out, zero_mask);
usb_handle* usb_handle_raw = result.get();
{
std::unique_lock<std::mutex> lock(usb_handles_mutex);
usb_handles[device_address] = std::move(result);
}
register_usb_transport(usb_handle_raw, device_serial.c_str(), device_address.c_str(), 1);
LOG(INFO) << "registered new usb device '" << device_serial << "'";
}
libusb_free_device_list(list, 1);
std::this_thread::sleep_for(500ms);
}
}
void usb_init() {
LOG(DEBUG) << "initializing libusb...";
int rc = libusb_init(nullptr);
if (rc != 0) {
LOG(FATAL) << "failed to initialize libusb: " << libusb_error_name(rc);
}
// Spawn a thread for libusb_handle_events.
std::thread([]() {
adb_thread_setname("libusb");
while (true) {
libusb_handle_events(nullptr);
}
}).detach();
// Spawn a thread to do device enumeration.
// TODO: Use libusb_hotplug_* instead?
device_poll_thread = new std::thread(poll_for_devices);
android::base::at_quick_exit([]() {
terminate_device_poll_thread = true;
std::unique_lock<std::mutex> lock(usb_handles_mutex);
for (auto& it : usb_handles) {
it.second->Close();
}
lock.unlock();
device_poll_thread->join();
});
}
// Dispatch a libusb transfer, unlock |device_lock|, and then wait for the result.
static int perform_usb_transfer(usb_handle* h, transfer_info* info,
std::unique_lock<std::mutex> device_lock) {
libusb_transfer* transfer = info->transfer;
transfer->user_data = info;
transfer->callback = [](libusb_transfer* transfer) {
transfer_info* info = static_cast<transfer_info*>(transfer->user_data);
LOG(DEBUG) << info->name << " transfer callback entered";
// Make sure that the original submitter has made it to the condition_variable wait.
std::unique_lock<std::mutex> lock(info->mutex);
LOG(DEBUG) << info->name << " callback successfully acquired lock";
if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
LOG(WARNING) << info->name
<< " transfer failed: " << libusb_error_name(transfer->status);
info->Notify();
return;
}
if (transfer->actual_length != transfer->length) {
LOG(DEBUG) << info->name << " transfer incomplete, resubmitting";
transfer->length -= transfer->actual_length;
transfer->buffer += transfer->actual_length;
int rc = libusb_submit_transfer(transfer);
if (rc != 0) {
LOG(WARNING) << "failed to submit " << info->name
<< " transfer: " << libusb_error_name(rc);
transfer->status = LIBUSB_TRANSFER_ERROR;
info->Notify();
}
return;
}
if (should_perform_zero_transfer(transfer->endpoint, transfer->length, info->zero_mask)) {
LOG(DEBUG) << "submitting zero-length write";
transfer->length = 0;
int rc = libusb_submit_transfer(transfer);
if (rc != 0) {
LOG(WARNING) << "failed to submit zero-length write: " << libusb_error_name(rc);
transfer->status = LIBUSB_TRANSFER_ERROR;
info->Notify();
}
return;
}
LOG(VERBOSE) << info->name << "transfer fully complete";
info->Notify();
};
LOG(DEBUG) << "locking " << info->name << " transfer_info mutex";
std::unique_lock<std::mutex> lock(info->mutex);
info->transfer_complete = false;
LOG(DEBUG) << "submitting " << info->name << " transfer";
int rc = libusb_submit_transfer(transfer);
if (rc != 0) {
LOG(WARNING) << "failed to submit " << info->name << " transfer: " << libusb_error_name(rc);
errno = EIO;
return -1;
}
LOG(DEBUG) << info->name << " transfer successfully submitted";
device_lock.unlock();
info->cv.wait(lock, [info]() { return info->transfer_complete; });
if (transfer->status != 0) {
errno = EIO;
return -1;
}
return 0;
}
int usb_write(usb_handle* h, const void* d, int len) {
LOG(DEBUG) << "usb_write of length " << len;
std::unique_lock<std::mutex> lock(h->device_handle_mutex);
if (!h->device_handle) {
errno = EIO;
return -1;
}
transfer_info* info = &h->write;
info->transfer->dev_handle = h->device_handle;
info->transfer->flags = 0;
info->transfer->endpoint = h->bulk_out;
info->transfer->type = LIBUSB_TRANSFER_TYPE_BULK;
info->transfer->length = len;
info->transfer->buffer = reinterpret_cast<unsigned char*>(const_cast<void*>(d));
info->transfer->num_iso_packets = 0;
int rc = perform_usb_transfer(h, info, std::move(lock));
LOG(DEBUG) << "usb_write(" << len << ") = " << rc;
return rc;
}
int usb_read(usb_handle* h, void* d, int len) {
LOG(DEBUG) << "usb_read of length " << len;
std::unique_lock<std::mutex> lock(h->device_handle_mutex);
if (!h->device_handle) {
errno = EIO;
return -1;
}
transfer_info* info = &h->read;
info->transfer->dev_handle = h->device_handle;
info->transfer->flags = 0;
info->transfer->endpoint = h->bulk_in;
info->transfer->type = LIBUSB_TRANSFER_TYPE_BULK;
info->transfer->length = len;
info->transfer->buffer = reinterpret_cast<unsigned char*>(d);
info->transfer->num_iso_packets = 0;
int rc = perform_usb_transfer(h, info, std::move(lock));
LOG(DEBUG) << "usb_read(" << len << ") = " << rc;
return rc;
}
int usb_close(usb_handle* h) {
std::unique_lock<std::mutex> lock(usb_handles_mutex);
auto it = usb_handles.find(h->device_address);
if (it == usb_handles.end()) {
LOG(FATAL) << "attempted to close unregistered usb_handle for '" << h->serial << "'";
}
usb_handles.erase(h->device_address);
return 0;
}
void usb_kick(usb_handle* h) {
h->Close();
}
} // namespace libusb