evdev: Fix crashing with touch devices

ui/events/ozone/evdev/event_device_info.cc

Index: ui/events/ozone/evdev/event_device_info.cc
diff --git a/ui/events/ozone/evdev/event_device_info.cc b/ui/events/ozone/evdev/event_device_info.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9621646d26b9b22445d58d43ceadc1e50afb634a
--- /dev/null
+++ b/ui/events/ozone/evdev/event_device_info.cc
@@ -0,0 +1,134 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/events/ozone/evdev/event_device_info.h"
+
+#include <linux/input.h>
+
+#include "base/logging.h"
+#include "base/threading/thread_restrictions.h"
+
+namespace ui {
+
+namespace {
+
+bool GetEventBits(int fd, unsigned int type, void* buf, unsigned int size) {
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  if (ioctl(fd, EVIOCGBIT(type, size), buf) < 0) {
+    DLOG(ERROR) << "failed EVIOCGBIT(" << type << ", " << size << ") on fd "
+                << fd;
+    return false;
+  }
+
+  return true;
+}
+
+bool GetPropBits(int fd, void* buf, unsigned int size) {
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  if (ioctl(fd, EVIOCGPROP(size), buf) < 0) {
+    DLOG(ERROR) << "failed EVIOCGPROP(" << size << ") on fd " << fd;
+    return false;
+  }
+
+  return true;
+}
+
+bool BitIsSet(const unsigned long* bits, unsigned int bit) {
+  return (bits[bit / EVDEV_LONG_BITS] & (1UL << (bit % EVDEV_LONG_BITS)));
+}
+
+}  // namespace
+
+EventDeviceInfo::EventDeviceInfo() {
+  memset(ev_bits_, 0, sizeof(ev_bits_));
+  memset(key_bits_, 0, sizeof(key_bits_));
+  memset(rel_bits_, 0, sizeof(rel_bits_));
+  memset(abs_bits_, 0, sizeof(abs_bits_));
+  memset(msc_bits_, 0, sizeof(msc_bits_));
+  memset(sw_bits_, 0, sizeof(sw_bits_));
+  memset(led_bits_, 0, sizeof(led_bits_));
+  memset(prop_bits_, 0, sizeof(prop_bits_));
+}
+
+EventDeviceInfo::~EventDeviceInfo() {}
+
+bool EventDeviceInfo::Initialize(int fd) {
+  if (!GetEventBits(fd, 0, ev_bits_, sizeof(ev_bits_)))
+    return false;
+
+  if (!GetEventBits(fd, EV_KEY, key_bits_, sizeof(key_bits_)))
+    return false;
+
+  if (!GetEventBits(fd, EV_REL, rel_bits_, sizeof(rel_bits_)))
+    return false;
+
+  if (!GetEventBits(fd, EV_ABS, abs_bits_, sizeof(abs_bits_)))
+    return false;
+
+  if (!GetEventBits(fd, EV_MSC, msc_bits_, sizeof(msc_bits_)))
+    return false;
+
+  if (!GetEventBits(fd, EV_SW, sw_bits_, sizeof(sw_bits_)))
+    return false;
+
+  if (!GetEventBits(fd, EV_LED, led_bits_, sizeof(led_bits_)))
+    return false;
+
+  if (!GetPropBits(fd, prop_bits_, sizeof(prop_bits_)))
+    return false;
+
+  return true;
+}
+
+bool EventDeviceInfo::HasEventType(unsigned int type) const {
+  if (type > EV_MAX)
+    return false;
+  return BitIsSet(ev_bits_, type);
+}
+
+bool EventDeviceInfo::HasKeyEvent(unsigned int code) const {
+  if (code > KEY_MAX)
+    return false;
+  return BitIsSet(key_bits_, code);
+}
+
+bool EventDeviceInfo::HasRelEvent(unsigned int code) const {
+  if (code > REL_MAX)
+    return false;
+  return BitIsSet(rel_bits_, code);
+}
+
+bool EventDeviceInfo::HasAbsEvent(unsigned int code) const {
+  if (code > ABS_MAX)
+    return false;
+  return BitIsSet(abs_bits_, code);
+}
+
+bool EventDeviceInfo::HasMscEvent(unsigned int code) const {
+  if (code > MSC_MAX)
+    return false;
+  return BitIsSet(msc_bits_, code);
+}
+
+bool EventDeviceInfo::HasSwEvent(unsigned int code) const {
+  if (code > SW_MAX)
+    return false;
+  return BitIsSet(sw_bits_, code);
+}
+
+bool EventDeviceInfo::HasLedEvent(unsigned int code) const {
+  if (code > LED_MAX)
+    return false;
+  return BitIsSet(led_bits_, code);
+}
+
+bool EventDeviceInfo::HasProp(unsigned int code) const {
+  if (code > INPUT_PROP_MAX)
+    return false;
+  return BitIsSet(prop_bits_, code);
+}
+
+}  // namespace ui