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android_system_core/adb/client/usb_linux.cpp
Daniel Colascione 3aef5c82f7 Properly finish daemon init when initial USB scan complete 
Call adb_notify_device_scan_complete when we finish enumerating USB
devices. The original intent of the code appears to have been to have
adb_wait_for_device_initialization return as soon as we've finished
looking around at the system USB environment on daemon startup, but at
some point, we forgot to actually notify the init thread that we
finished scanning all the USB devices, forcing the wait on init_cv to
time out after three seconds on every daemon initialization.

After this change, the daemon starts in a few milliseconds on my Linux
machine

Test: killall adb && sleep 1 && time adb server && adb shell ls
Change-Id: I0bc1da7a597d2077dd2b591560d03798b05905b7
2019-11-04 11:43:20 -08:00

631 lines
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/*
* Copyright (C) 2007 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.
*/
#define TRACE_TAG USB
#include "sysdeps.h"
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/usb/ch9.h>
#include <linux/usbdevice_fs.h>
#include <linux/version.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <unistd.h>
#include <chrono>
#include <condition_variable>
#include <list>
#include <mutex>
#include <string>
#include <string_view>
#include <thread>
#include <android-base/file.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include "adb.h"
#include "transport.h"
#include "usb.h"
using namespace std::chrono_literals;
using namespace std::literals;
/* usb scan debugging is waaaay too verbose */
#define DBGX(x...)
namespace native {
struct usb_handle : public ::usb_handle {
~usb_handle() {
if (fd != -1) unix_close(fd);
}
std::string path;
int fd = -1;
unsigned char ep_in;
unsigned char ep_out;
size_t max_packet_size;
unsigned zero_mask;
unsigned writeable = 1;
usbdevfs_urb urb_in;
usbdevfs_urb urb_out;
bool urb_in_busy = false;
bool urb_out_busy = false;
bool dead = false;
std::condition_variable cv;
std::mutex mutex;
// for garbage collecting disconnected devices
bool mark;
// ID of thread currently in REAPURB
pthread_t reaper_thread = 0;
};
static auto& g_usb_handles_mutex = *new std::mutex();
static auto& g_usb_handles = *new std::list<usb_handle*>();
static int is_known_device(std::string_view dev_name) {
std::lock_guard<std::mutex> lock(g_usb_handles_mutex);
for (usb_handle* usb : g_usb_handles) {
if (usb->path == dev_name) {
// set mark flag to indicate this device is still alive
usb->mark = true;
return 1;
}
}
return 0;
}
static void kick_disconnected_devices() {
std::lock_guard<std::mutex> lock(g_usb_handles_mutex);
// kick any devices in the device list that were not found in the device scan
for (usb_handle* usb : g_usb_handles) {
if (!usb->mark) {
usb_kick(usb);
} else {
usb->mark = false;
}
}
}
static inline bool contains_non_digit(const char* name) {
while (*name) {
if (!isdigit(*name++)) return true;
}
return false;
}
static void find_usb_device(const std::string& base,
void (*register_device_callback)(const char*, const char*,
unsigned char, unsigned char, int, int,
unsigned, size_t)) {
std::unique_ptr<DIR, int(*)(DIR*)> bus_dir(opendir(base.c_str()), closedir);
if (!bus_dir) return;
dirent* de;
while ((de = readdir(bus_dir.get())) != nullptr) {
if (contains_non_digit(de->d_name)) continue;
std::string bus_name = base + "/" + de->d_name;
std::unique_ptr<DIR, int(*)(DIR*)> dev_dir(opendir(bus_name.c_str()), closedir);
if (!dev_dir) continue;
while ((de = readdir(dev_dir.get()))) {
unsigned char devdesc[4096];
unsigned char* bufptr = devdesc;
unsigned char* bufend;
struct usb_device_descriptor* device;
struct usb_config_descriptor* config;
struct usb_interface_descriptor* interface;
struct usb_endpoint_descriptor *ep1, *ep2;
unsigned zero_mask = 0;
size_t max_packet_size = 0;
unsigned vid, pid;
if (contains_non_digit(de->d_name)) continue;
std::string dev_name = bus_name + "/" + de->d_name;
if (is_known_device(dev_name)) {
continue;
}
int fd = unix_open(dev_name, O_RDONLY | O_CLOEXEC);
if (fd == -1) {
continue;
}
size_t desclength = unix_read(fd, devdesc, sizeof(devdesc));
bufend = bufptr + desclength;
// should have device and configuration descriptors, and atleast two endpoints
if (desclength < USB_DT_DEVICE_SIZE + USB_DT_CONFIG_SIZE) {
D("desclength %zu is too small", desclength);
unix_close(fd);
continue;
}
device = (struct usb_device_descriptor*)bufptr;
bufptr += USB_DT_DEVICE_SIZE;
if((device->bLength != USB_DT_DEVICE_SIZE) || (device->bDescriptorType != USB_DT_DEVICE)) {
unix_close(fd);
continue;
}
vid = device->idVendor;
pid = device->idProduct;
DBGX("[ %s is V:%04x P:%04x ]\n", dev_name.c_str(), vid, pid);
// should have config descriptor next
config = (struct usb_config_descriptor *)bufptr;
bufptr += USB_DT_CONFIG_SIZE;
if (config->bLength != USB_DT_CONFIG_SIZE || config->bDescriptorType != USB_DT_CONFIG) {
D("usb_config_descriptor not found");
unix_close(fd);
continue;
}
// loop through all the descriptors and look for the ADB interface
while (bufptr < bufend) {
unsigned char length = bufptr[0];
unsigned char type = bufptr[1];
if (type == USB_DT_INTERFACE) {
interface = (struct usb_interface_descriptor *)bufptr;
bufptr += length;
if (length != USB_DT_INTERFACE_SIZE) {
D("interface descriptor has wrong size");
break;
}
DBGX("bInterfaceClass: %d, bInterfaceSubClass: %d,"
"bInterfaceProtocol: %d, bNumEndpoints: %d\n",
interface->bInterfaceClass, interface->bInterfaceSubClass,
interface->bInterfaceProtocol, interface->bNumEndpoints);
if (interface->bNumEndpoints == 2 &&
is_adb_interface(interface->bInterfaceClass, interface->bInterfaceSubClass,
interface->bInterfaceProtocol)) {
struct stat st;
char pathbuf[128];
char link[256];
char *devpath = nullptr;
DBGX("looking for bulk endpoints\n");
// looks like ADB...
ep1 = (struct usb_endpoint_descriptor *)bufptr;
bufptr += USB_DT_ENDPOINT_SIZE;
// For USB 3.0 SuperSpeed devices, skip potential
// USB 3.0 SuperSpeed Endpoint Companion descriptor
if (bufptr+2 <= devdesc + desclength &&
bufptr[0] == USB_DT_SS_EP_COMP_SIZE &&
bufptr[1] == USB_DT_SS_ENDPOINT_COMP) {
bufptr += USB_DT_SS_EP_COMP_SIZE;
}
ep2 = (struct usb_endpoint_descriptor *)bufptr;
bufptr += USB_DT_ENDPOINT_SIZE;
if (bufptr+2 <= devdesc + desclength &&
bufptr[0] == USB_DT_SS_EP_COMP_SIZE &&
bufptr[1] == USB_DT_SS_ENDPOINT_COMP) {
bufptr += USB_DT_SS_EP_COMP_SIZE;
}
if (bufptr > devdesc + desclength ||
ep1->bLength != USB_DT_ENDPOINT_SIZE ||
ep1->bDescriptorType != USB_DT_ENDPOINT ||
ep2->bLength != USB_DT_ENDPOINT_SIZE ||
ep2->bDescriptorType != USB_DT_ENDPOINT) {
D("endpoints not found");
break;
}
// both endpoints should be bulk
if (ep1->bmAttributes != USB_ENDPOINT_XFER_BULK ||
ep2->bmAttributes != USB_ENDPOINT_XFER_BULK) {
D("bulk endpoints not found");
continue;
}
/* aproto 01 needs 0 termination */
if (interface->bInterfaceProtocol == ADB_PROTOCOL) {
max_packet_size = ep1->wMaxPacketSize;
zero_mask = ep1->wMaxPacketSize - 1;
}
// we have a match. now we just need to figure out which is in and which is out.
unsigned char local_ep_in, local_ep_out;
if (ep1->bEndpointAddress & USB_ENDPOINT_DIR_MASK) {
local_ep_in = ep1->bEndpointAddress;
local_ep_out = ep2->bEndpointAddress;
} else {
local_ep_in = ep2->bEndpointAddress;
local_ep_out = ep1->bEndpointAddress;
}
// Determine the device path
if (!fstat(fd, &st) && S_ISCHR(st.st_mode)) {
snprintf(pathbuf, sizeof(pathbuf), "/sys/dev/char/%d:%d",
major(st.st_rdev), minor(st.st_rdev));
ssize_t link_len = readlink(pathbuf, link, sizeof(link) - 1);
if (link_len > 0) {
link[link_len] = '\0';
const char* slash = strrchr(link, '/');
if (slash) {
snprintf(pathbuf, sizeof(pathbuf),
"usb:%s", slash + 1);
devpath = pathbuf;
}
}
}
register_device_callback(dev_name.c_str(), devpath, local_ep_in,
local_ep_out, interface->bInterfaceNumber,
device->iSerialNumber, zero_mask, max_packet_size);
break;
}
} else {
bufptr += length;
}
} // end of while
unix_close(fd);
}
}
}
static int usb_bulk_write(usb_handle* h, const void* data, int len) {
std::unique_lock<std::mutex> lock(h->mutex);
D("++ usb_bulk_write ++");
usbdevfs_urb* urb = &h->urb_out;
memset(urb, 0, sizeof(*urb));
urb->type = USBDEVFS_URB_TYPE_BULK;
urb->endpoint = h->ep_out;
urb->status = -1;
urb->buffer = const_cast<void*>(data);
urb->buffer_length = len;
if (h->dead) {
errno = EINVAL;
return -1;
}
if (TEMP_FAILURE_RETRY(ioctl(h->fd, USBDEVFS_SUBMITURB, urb)) == -1) {
return -1;
}
h->urb_out_busy = true;
while (true) {
auto now = std::chrono::steady_clock::now();
if (h->cv.wait_until(lock, now + 5s) == std::cv_status::timeout || h->dead) {
// TODO: call USBDEVFS_DISCARDURB?
errno = ETIMEDOUT;
return -1;
}
if (!h->urb_out_busy) {
if (urb->status != 0) {
errno = -urb->status;
return -1;
}
return urb->actual_length;
}
}
}
static int usb_bulk_read(usb_handle* h, void* data, int len) {
std::unique_lock<std::mutex> lock(h->mutex);
D("++ usb_bulk_read ++");
usbdevfs_urb* urb = &h->urb_in;
memset(urb, 0, sizeof(*urb));
urb->type = USBDEVFS_URB_TYPE_BULK;
urb->endpoint = h->ep_in;
urb->status = -1;
urb->buffer = data;
urb->buffer_length = len;
if (h->dead) {
errno = EINVAL;
return -1;
}
if (TEMP_FAILURE_RETRY(ioctl(h->fd, USBDEVFS_SUBMITURB, urb)) == -1) {
return -1;
}
h->urb_in_busy = true;
while (true) {
D("[ reap urb - wait ]");
h->reaper_thread = pthread_self();
int fd = h->fd;
lock.unlock();
// This ioctl must not have TEMP_FAILURE_RETRY because we send SIGALRM to break out.
usbdevfs_urb* out = nullptr;
int res = ioctl(fd, USBDEVFS_REAPURB, &out);
int saved_errno = errno;
lock.lock();
h->reaper_thread = 0;
if (h->dead) {
errno = EINVAL;
return -1;
}
if (res < 0) {
if (saved_errno == EINTR) {
continue;
}
D("[ reap urb - error ]");
errno = saved_errno;
return -1;
}
D("[ urb @%p status = %d, actual = %d ]", out, out->status, out->actual_length);
if (out == &h->urb_in) {
D("[ reap urb - IN complete ]");
h->urb_in_busy = false;
if (urb->status != 0) {
errno = -urb->status;
return -1;
}
return urb->actual_length;
}
if (out == &h->urb_out) {
D("[ reap urb - OUT compelete ]");
h->urb_out_busy = false;
h->cv.notify_all();
}
}
}
static int usb_write_split(usb_handle* h, unsigned char* data, int len) {
for (int i = 0; i < len; i += 16384) {
int chunk_size = (i + 16384 > len) ? len - i : 16384;
int n = usb_bulk_write(h, data + i, chunk_size);
if (n != chunk_size) {
D("ERROR: n = %d, errno = %d (%s)", n, errno, strerror(errno));
return -1;
}
}
return len;
}
int usb_write(usb_handle* h, const void* _data, int len) {
D("++ usb_write ++");
unsigned char* data = (unsigned char*)_data;
// The kernel will attempt to allocate a contiguous buffer for each write we submit.
// This might fail due to heap fragmentation, so attempt a contiguous write once, and if that
// fails, retry after having split the data into 16kB chunks to avoid allocation failure.
int n = usb_bulk_write(h, data, len);
if (n == -1 && errno == ENOMEM) {
n = usb_write_split(h, data, len);
}
if (n == -1) {
return -1;
}
if (h->zero_mask && !(len & h->zero_mask)) {
// If we need 0-markers and our transfer is an even multiple of the packet size,
// then send a zero marker.
return usb_bulk_write(h, _data, 0) == 0 ? len : -1;
}
D("-- usb_write --");
return len;
}
int usb_read(usb_handle *h, void *_data, int len)
{
unsigned char *data = (unsigned char*) _data;
int n;
D("++ usb_read ++");
int orig_len = len;
while (len == orig_len) {
int xfer = len;
D("[ usb read %d fd = %d], path=%s", xfer, h->fd, h->path.c_str());
n = usb_bulk_read(h, data, xfer);
D("[ usb read %d ] = %d, path=%s", xfer, n, h->path.c_str());
if (n <= 0) {
if((errno == ETIMEDOUT) && (h->fd != -1)) {
D("[ timeout ]");
continue;
}
D("ERROR: n = %d, errno = %d (%s)",
n, errno, strerror(errno));
return -1;
}
len -= n;
data += n;
}
D("-- usb_read --");
return orig_len - len;
}
void usb_reset(usb_handle* h) {
ioctl(h->fd, USBDEVFS_RESET);
usb_kick(h);
}
void usb_kick(usb_handle* h) {
std::lock_guard<std::mutex> lock(h->mutex);
D("[ kicking %p (fd = %d) ]", h, h->fd);
if (!h->dead) {
h->dead = true;
if (h->writeable) {
/* HACK ALERT!
** Sometimes we get stuck in ioctl(USBDEVFS_REAPURB).
** This is a workaround for that problem.
*/
if (h->reaper_thread) {
pthread_kill(h->reaper_thread, SIGALRM);
}
/* cancel any pending transactions
** these will quietly fail if the txns are not active,
** but this ensures that a reader blocked on REAPURB
** will get unblocked
*/
ioctl(h->fd, USBDEVFS_DISCARDURB, &h->urb_in);
ioctl(h->fd, USBDEVFS_DISCARDURB, &h->urb_out);
h->urb_in.status = -ENODEV;
h->urb_out.status = -ENODEV;
h->urb_in_busy = false;
h->urb_out_busy = false;
h->cv.notify_all();
} else {
unregister_usb_transport(h);
}
}
}
int usb_close(usb_handle* h) {
std::lock_guard<std::mutex> lock(g_usb_handles_mutex);
g_usb_handles.remove(h);
D("-- usb close %p (fd = %d) --", h, h->fd);
delete h;
return 0;
}
size_t usb_get_max_packet_size(usb_handle* h) {
return h->max_packet_size;
}
static void register_device(const char* dev_name, const char* dev_path, unsigned char ep_in,
unsigned char ep_out, int interface, int serial_index,
unsigned zero_mask, size_t max_packet_size) {
// Since Linux will not reassign the device ID (and dev_name) as long as the
// device is open, we can add to the list here once we open it and remove
// from the list when we're finally closed and everything will work out
// fine.
//
// If we have a usb_handle on the list of handles with a matching name, we
// have no further work to do.
{
std::lock_guard<std::mutex> lock(g_usb_handles_mutex);
for (usb_handle* usb: g_usb_handles) {
if (usb->path == dev_name) {
return;
}
}
}
D("[ usb located new device %s (%d/%d/%d) ]", dev_name, ep_in, ep_out, interface);
std::unique_ptr<usb_handle> usb(new usb_handle);
usb->path = dev_name;
usb->ep_in = ep_in;
usb->ep_out = ep_out;
usb->zero_mask = zero_mask;
usb->max_packet_size = max_packet_size;
// Initialize mark so we don't get garbage collected after the device scan.
usb->mark = true;
usb->fd = unix_open(usb->path, O_RDWR | O_CLOEXEC);
if (usb->fd == -1) {
// Opening RW failed, so see if we have RO access.
usb->fd = unix_open(usb->path, O_RDONLY | O_CLOEXEC);
if (usb->fd == -1) {
D("[ usb open %s failed: %s]", usb->path.c_str(), strerror(errno));
return;
}
usb->writeable = 0;
}
D("[ usb opened %s%s, fd=%d]",
usb->path.c_str(), (usb->writeable ? "" : " (read-only)"), usb->fd);
if (usb->writeable) {
if (ioctl(usb->fd, USBDEVFS_CLAIMINTERFACE, &interface) != 0) {
D("[ usb ioctl(%d, USBDEVFS_CLAIMINTERFACE) failed: %s]", usb->fd, strerror(errno));
return;
}
}
// Read the device's serial number.
std::string serial_path = android::base::StringPrintf(
"/sys/bus/usb/devices/%s/serial", dev_path + 4);
std::string serial;
if (!android::base::ReadFileToString(serial_path, &serial)) {
D("[ usb read %s failed: %s ]", serial_path.c_str(), strerror(errno));
// We don't actually want to treat an unknown serial as an error because
// devices aren't able to communicate a serial number in early bringup.
// http://b/20883914
serial = "";
}
serial = android::base::Trim(serial);
// Add to the end of the active handles.
usb_handle* done_usb = usb.release();
{
std::lock_guard<std::mutex> lock(g_usb_handles_mutex);
g_usb_handles.push_back(done_usb);
}
register_usb_transport(done_usb, serial.c_str(), dev_path, done_usb->writeable);
}
static void device_poll_thread() {
adb_thread_setname("device poll");
D("Created device thread");
while (true) {
// TODO: Use inotify.
find_usb_device("/dev/bus/usb", register_device);
adb_notify_device_scan_complete();
kick_disconnected_devices();
std::this_thread::sleep_for(1s);
}
}
void usb_init() {
struct sigaction actions;
memset(&actions, 0, sizeof(actions));
sigemptyset(&actions.sa_mask);
actions.sa_flags = 0;
actions.sa_handler = [](int) {};
sigaction(SIGALRM, &actions, nullptr);
std::thread(device_poll_thread).detach();
}
void usb_cleanup() {}
} // namespace native
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