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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.
*/
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/input.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/epoll.h>
#include <sys/inotify.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <unistd.h>
#include <functional>
#include <memory>
#include <android-base/unique_fd.h>
#include "minui/minui.h"
constexpr const char* INPUT_DEV_DIR = "/dev/input";
constexpr size_t MAX_DEVICES = 16;
constexpr size_t MAX_MISC_FDS = 16;
constexpr size_t BITS_PER_LONG = sizeof(unsigned long) * 8;
constexpr size_t BITS_TO_LONGS(size_t bits) {
return ((bits + BITS_PER_LONG - 1) / BITS_PER_LONG);
}
struct FdInfo {
android::base::unique_fd fd;
ev_callback cb;
};
static bool g_allow_touch_inputs = true;
static ev_callback g_saved_input_cb;
static android::base::unique_fd g_epoll_fd;
static epoll_event g_polled_events[MAX_DEVICES + MAX_MISC_FDS];
static int g_polled_events_count;
static FdInfo ev_fdinfo[MAX_DEVICES + MAX_MISC_FDS];
static size_t g_ev_count = 0;
static size_t g_ev_dev_count = 0;
static size_t g_ev_misc_count = 0;
static bool test_bit(size_t bit, unsigned long* array) { // NOLINT
return (array[bit / BITS_PER_LONG] & (1UL << (bit % BITS_PER_LONG))) != 0;
}
static bool should_add_input_device(int fd, bool allow_touch_inputs) {
// Use unsigned long to match ioctl's parameter type.
unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)]; // NOLINT
// Read the evbits of the input device.
if (ioctl(fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
return false;
}
// We assume that only EV_KEY, EV_REL, and EV_SW event types are ever needed. EV_ABS is also
// allowed if allow_touch_inputs is set.
if (!test_bit(EV_KEY, ev_bits) && !test_bit(EV_REL, ev_bits) && !test_bit(EV_SW, ev_bits)) {
if (!allow_touch_inputs || !test_bit(EV_ABS, ev_bits)) {
return false;
}
}
return true;
}
static int inotify_cb(int fd, __unused uint32_t epevents) {
if (g_saved_input_cb == nullptr) return -1;
// The inotify will put one or several complete events.
// Should not read part of one event.
int event_len_int;
int ret = ioctl(fd, FIONREAD, &event_len_int);
if (ret != 0) return -1;
if (event_len_int < 0) return -1;
size_t event_len = event_len_int;
std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(INPUT_DEV_DIR), closedir);
if (!dir) {
return -1;
}
std::vector<int8_t> buf(event_len);
ssize_t r = TEMP_FAILURE_RETRY(read(fd, buf.data(), event_len));
if (r != event_len) {
return -1;
}
size_t offset = 0;
while (offset < event_len) {
struct inotify_event* pevent = reinterpret_cast<struct inotify_event*>(buf.data() + offset);
if (offset + sizeof(inotify_event) + pevent->len > event_len) {
// The pevent->len is too large and buffer will over flow.
// In general, should not happen, just make more stable.
return -1;
}
offset += sizeof(inotify_event) + pevent->len;
pevent->name[pevent->len] = '\0';
if (strncmp(pevent->name, "event", 5)) {
continue;
}
android::base::unique_fd dfd(openat(dirfd(dir.get()), pevent->name, O_RDONLY));
if (dfd == -1) {
break;
}
if (!should_add_input_device(dfd, g_allow_touch_inputs)) {
continue;
}
// Only add, we assume the user will not plug out and plug in USB device again and again :)
ev_add_fd(std::move(dfd), g_saved_input_cb);
}
return 0;
}
int ev_init(ev_callback input_cb, bool allow_touch_inputs) {
g_epoll_fd.reset();
android::base::unique_fd epoll_fd(epoll_create1(EPOLL_CLOEXEC));
if (epoll_fd == -1) {
return -1;
}
android::base::unique_fd inotify_fd(inotify_init1(IN_CLOEXEC));
if (inotify_fd.get() == -1) {
return -1;
}
if (inotify_add_watch(inotify_fd, INPUT_DEV_DIR, IN_CREATE) < 0) {
return -1;
}
std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(INPUT_DEV_DIR), closedir);
if (!dir) {
return -1;
}
bool epoll_ctl_failed = false;
dirent* de;
while ((de = readdir(dir.get())) != nullptr) {
if (strncmp(de->d_name, "event", 5)) continue;
android::base::unique_fd fd(openat(dirfd(dir.get()), de->d_name, O_RDONLY | O_CLOEXEC));
if (fd == -1) continue;
if (!should_add_input_device(fd, allow_touch_inputs)) {
continue;
}
epoll_event ev;
ev.events = EPOLLIN | EPOLLWAKEUP;
ev.data.ptr = &ev_fdinfo[g_ev_count];
if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev) == -1) {
epoll_ctl_failed = true;
continue;
}
ev_fdinfo[g_ev_count].fd.reset(fd.release());
ev_fdinfo[g_ev_count].cb = input_cb;
g_ev_count++;
g_ev_dev_count++;
if (g_ev_dev_count == MAX_DEVICES) break;
}
if (epoll_ctl_failed && !g_ev_count) {
return -1;
}
g_epoll_fd.reset(epoll_fd.release());
g_saved_input_cb = input_cb;
g_allow_touch_inputs = allow_touch_inputs;
ev_add_fd(std::move(inotify_fd), inotify_cb);
return 0;
}
int ev_get_epollfd(void) {
return g_epoll_fd.get();
}
int ev_add_fd(android::base::unique_fd&& fd, ev_callback cb) {
if (g_ev_misc_count == MAX_MISC_FDS || cb == nullptr) {
return -1;
}
epoll_event ev;
ev.events = EPOLLIN | EPOLLWAKEUP;
ev.data.ptr = static_cast<void*>(&ev_fdinfo[g_ev_count]);
int ret = epoll_ctl(g_epoll_fd, EPOLL_CTL_ADD, fd, &ev);
if (!ret) {
ev_fdinfo[g_ev_count].fd.reset(fd.release());
ev_fdinfo[g_ev_count].cb = std::move(cb);
g_ev_count++;
g_ev_misc_count++;
}
return ret;
}
void ev_exit(void) {
while (g_ev_count > 0) {
ev_fdinfo[--g_ev_count].fd.reset();
}
g_ev_misc_count = 0;
g_ev_dev_count = 0;
g_saved_input_cb = nullptr;
g_epoll_fd.reset();
}
int ev_wait(int timeout) {
g_polled_events_count = epoll_wait(g_epoll_fd, g_polled_events, g_ev_count, timeout);
if (g_polled_events_count <= 0) {
return -1;
}
return 0;
}
void ev_dispatch(void) {
for (int n = 0; n < g_polled_events_count; n++) {
FdInfo* fdi = static_cast<FdInfo*>(g_polled_events[n].data.ptr);
const ev_callback& cb = fdi->cb;
if (cb) {
cb(fdi->fd, g_polled_events[n].events);
}
}
}
int ev_get_input(int fd, uint32_t epevents, input_event* ev) {
if (epevents & EPOLLIN) {
ssize_t r = TEMP_FAILURE_RETRY(read(fd, ev, sizeof(*ev)));
if (r == sizeof(*ev)) {
return 0;
}
}
if (epevents & EPOLLHUP) {
// Delete this watch
epoll_ctl(g_epoll_fd, EPOLL_CTL_DEL, fd, nullptr);
}
return -1;
}
int ev_sync_key_state(const ev_set_key_callback& set_key_cb) {
// Use unsigned long to match ioctl's parameter type.
unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)]; // NOLINT
unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)]; // NOLINT
for (size_t i = 0; i < g_ev_dev_count; ++i) {
memset(ev_bits, 0, sizeof(ev_bits));
memset(key_bits, 0, sizeof(key_bits));
if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
continue;
}
if (!test_bit(EV_KEY, ev_bits)) {
continue;
}
if (ioctl(ev_fdinfo[i].fd, EVIOCGKEY(sizeof(key_bits)), key_bits) == -1) {
continue;
}
for (int code = 0; code <= KEY_MAX; code++) {
if (test_bit(code, key_bits)) {
set_key_cb(code, 1);
}
}
}
return 0;
}
void ev_iterate_available_keys(const std::function<void(int)>& f) {
// Use unsigned long to match ioctl's parameter type.
unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)]; // NOLINT
unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)]; // NOLINT
for (size_t i = 0; i < g_ev_dev_count; ++i) {
memset(ev_bits, 0, sizeof(ev_bits));
memset(key_bits, 0, sizeof(key_bits));
// Does this device even have keys?
if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
continue;
}
if (!test_bit(EV_KEY, ev_bits)) {
continue;
}
if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(EV_KEY, KEY_MAX), key_bits) == -1) {
continue;
}
for (int key_code = 0; key_code <= KEY_MAX; ++key_code) {
if (test_bit(key_code, key_bits)) {
f(key_code);
}
}
}
}
void ev_iterate_touch_inputs(const std::function<void(int)>& action) {
for (size_t i = 0; i < g_ev_dev_count; ++i) {
// Use unsigned long to match ioctl's parameter type.
unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)] = {}; // NOLINT
if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
continue;
}
if (!test_bit(EV_ABS, ev_bits)) {
continue;
}
unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)] = {}; // NOLINT
if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(EV_ABS, KEY_MAX), key_bits) == -1) {
continue;
}
for (int key_code = 0; key_code <= KEY_MAX; ++key_code) {
if (test_bit(key_code, key_bits)) {
action(key_code);
}
}
}
}