boo/lib/inputdev/HIDListenerUdev.cpp

#include "boo/inputdev/IHIDListener.hpp"
#include "boo/inputdev/DeviceFinder.hpp"
#include "boo/inputdev/HIDParser.hpp"
#include "logvisor/logvisor.hpp"
#include <libudev.h>
#include <cstring>
#include <cstdio>
#include <signal.h>
#include <fcntl.h>
#include <linux/hidraw.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <thread>

namespace boo {

static udev* UDEV_INST = nullptr;
udev* GetUdev() {
  if (!UDEV_INST)
    UDEV_INST = udev_new();
  return UDEV_INST;
}

class HIDListenerUdev final : public IHIDListener {
  DeviceFinder& m_finder;

  udev_monitor* m_udevMon;
  std::thread m_udevThread;
  bool m_scanningEnabled;

  void deviceConnected(udev_device* device) {
    if (!m_scanningEnabled)
      return;

    /* Prevent redundant registration */
    const char* devPath = udev_device_get_syspath(device);
    if (m_finder._hasToken(devPath))
      return;

    /* Filter to USB/BT */
    const char* dt = udev_device_get_devtype(device);
    DeviceType type;
    int vid = 0, pid = 0;
    const char* manuf = nullptr;
    const char* product = nullptr;
    if (dt) {
      if (!strcmp(dt, "usb_device"))
        type = DeviceType::USB;
      else if (!strcmp(dt, "bluetooth_device"))
        type = DeviceType::Bluetooth;
      else
        return;

      udev_list_entry* attrs = udev_device_get_properties_list_entry(device);
      udev_list_entry* vide = udev_list_entry_get_by_name(attrs, "ID_VENDOR_ID");
      if (vide)
        vid = strtol(udev_list_entry_get_value(vide), nullptr, 16);

      udev_list_entry* pide = udev_list_entry_get_by_name(attrs, "ID_MODEL_ID");
      if (pide)
        pid = strtol(udev_list_entry_get_value(pide), nullptr, 16);

      udev_list_entry* manufe = udev_list_entry_get_by_name(attrs, "ID_VENDOR");
      if (manufe)
        manuf = udev_list_entry_get_value(manufe);

      udev_list_entry* producte = udev_list_entry_get_by_name(attrs, "ID_MODEL");
      if (producte)
        product = udev_list_entry_get_value(producte);
    } else if (!strcmp(udev_device_get_subsystem(device), "hidraw")) {
      type = DeviceType::HID;
      udev_device* parent = udev_device_get_parent(device);
      udev_list_entry* attrs = udev_device_get_properties_list_entry(parent);

      udev_list_entry* hidide = udev_list_entry_get_by_name(attrs, "HID_ID");
      if (hidide) {
        const char* hidid = udev_list_entry_get_value(hidide);
        const char* vids = strchr(hidid, ':') + 1;
        const char* pids = strchr(vids, ':') + 1;
        vid = strtol(vids, nullptr, 16);
        pid = strtol(pids, nullptr, 16);
      }

      udev_list_entry* hidnamee = udev_list_entry_get_by_name(attrs, "HID_NAME");
      if (hidnamee) {
        product = udev_list_entry_get_value(hidnamee);
        manuf = product;
      }

      /* Get device file */
      const char* dp = udev_device_get_devnode(device);
      int fd = open(dp, O_RDWR);
      if (fd < 0)
        return;

      /* Report descriptor size */
      int reportDescSize;
      if (ioctl(fd, HIDIOCGRDESCSIZE, &reportDescSize) == -1) {
        // const char* err = strerror(errno);
        close(fd);
        return;
      }

      /* Get report descriptor */
      hidraw_report_descriptor reportDesc;
      reportDesc.size = reportDescSize;
      if (ioctl(fd, HIDIOCGRDESC, &reportDesc) == -1) {
        // const char* err = strerror(errno);
        close(fd);
        return;
      }
      close(fd);

      std::pair<HIDUsagePage, HIDUsage> usage = HIDParser::GetApplicationUsage(reportDesc.value, reportDesc.size);
      if (usage.first != HIDUsagePage::GenericDesktop ||
          (usage.second != HIDUsage::Joystick && usage.second != HIDUsage::GamePad))
        return;
    }

#if 0
    udev_list_entry* att = nullptr;
    udev_list_entry_foreach(att, attrs)
    {
      const char* name = udev_list_entry_get_name(att);
      const char* val = udev_list_entry_get_value(att);
      fmt::print(stderr, fmt("{} {}\n"), name, val);
    }
    std::fputs("\n\n", stderr);
#endif

    m_finder._insertToken(std::make_unique<DeviceToken>(type, vid, pid, manuf, product, devPath));
  }

  void deviceDisconnected(udev_device* device) {
    const char* devPath = udev_device_get_syspath(device);
    m_finder._removeToken(devPath);
  }

  void _udevProc() {
    logvisor::RegisterThreadName("Boo udev");
    udev_monitor_enable_receiving(m_udevMon);
    int fd = udev_monitor_get_fd(m_udevMon);
    while (true) {
      fd_set fds;
      FD_ZERO(&fds);
      FD_SET(fd, &fds);
      if (pselect(fd + 1, &fds, nullptr, nullptr, nullptr, nullptr) < 0) {
        /* SIGTERM handled here */
        if (errno == EINTR)
          break;
      }
      int oldtype;
      pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldtype);
      udev_device* dev = udev_monitor_receive_device(m_udevMon);
      if (dev) {
        const char* action = udev_device_get_action(dev);
        if (!strcmp(action, "add"))
          deviceConnected(dev);
        else if (!strcmp(action, "remove"))
          deviceDisconnected(dev);
        udev_device_unref(dev);
      }
      pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldtype);
      pthread_testcancel();
    }
  }

public:
  HIDListenerUdev(DeviceFinder& finder) : m_finder(finder) {
    /* Setup hotplug events */
    m_udevMon = udev_monitor_new_from_netlink(GetUdev(), "udev");
    if (!m_udevMon) {
      fmt::print(stderr, fmt("unable to init udev_monitor"));
      abort();
    }
    udev_monitor_filter_add_match_subsystem_devtype(m_udevMon, "usb", "usb_device");
    udev_monitor_filter_add_match_subsystem_devtype(m_udevMon, "bluetooth", "bluetooth_device");
    udev_monitor_filter_add_match_subsystem_devtype(m_udevMon, "hidraw", nullptr);
    udev_monitor_filter_update(m_udevMon);

    /* Initial HID Device Add */
    m_scanningEnabled = true;
    scanNow();
    m_scanningEnabled = false;

    /* Start hotplug thread */
    m_udevThread = std::thread(std::bind(&HIDListenerUdev::_udevProc, this), this);
  }

  ~HIDListenerUdev() override {
    pthread_cancel(m_udevThread.native_handle());
    if (m_udevThread.joinable())
      m_udevThread.join();
    udev_monitor_unref(m_udevMon);
  }

  /* Automatic device scanning */
  bool startScanning() override {
    m_scanningEnabled = true;
    return true;
  }
  bool stopScanning() override {
    m_scanningEnabled = false;
    return true;
  }

  /* Manual device scanning */
  bool scanNow() override {
    udev_enumerate* uenum = udev_enumerate_new(GetUdev());
    udev_enumerate_add_match_subsystem(uenum, "usb");
    udev_enumerate_add_match_subsystem(uenum, "bluetooth");
    udev_enumerate_add_match_subsystem(uenum, "hidraw");
    udev_enumerate_scan_devices(uenum);
    udev_list_entry* uenumList = udev_enumerate_get_list_entry(uenum);
    udev_list_entry* uenumItem;
    udev_list_entry_foreach(uenumItem, uenumList) {
      const char* devPath = udev_list_entry_get_name(uenumItem);
      udev_device* dev = udev_device_new_from_syspath(UDEV_INST, devPath);
      if (dev)
        deviceConnected(dev);
      udev_device_unref(dev);
    }
    udev_enumerate_unref(uenum);
    return true;
  }
};

std::unique_ptr<IHIDListener> IHIDListenerNew(DeviceFinder& finder) {
  return std::make_unique<HIDListenerUdev>(finder);
}

} // namespace boo