1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <dirent.h>
18#include <errno.h>
19#include <fcntl.h>
20#include <linux/input.h>
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <sys/epoll.h>
25#include <sys/ioctl.h>
26#include <unistd.h>
27
28#include <functional>
29
30#include "minui/minui.h"
31
32#define MAX_DEVICES 16
33#define MAX_MISC_FDS 16
34
35#define BITS_PER_LONG (sizeof(unsigned long) * 8)
36#define BITS_TO_LONGS(x) (((x) + BITS_PER_LONG - 1) / BITS_PER_LONG)
37
38struct fd_info {
39  int fd;
40  ev_callback cb;
41};
42
43static int g_epoll_fd;
44static epoll_event polledevents[MAX_DEVICES + MAX_MISC_FDS];
45static int npolledevents;
46
47static fd_info ev_fdinfo[MAX_DEVICES + MAX_MISC_FDS];
48
49static unsigned ev_count = 0;
50static unsigned ev_dev_count = 0;
51static unsigned ev_misc_count = 0;
52
53static bool test_bit(size_t bit, unsigned long* array) { // NOLINT
54    return (array[bit/BITS_PER_LONG] & (1UL << (bit % BITS_PER_LONG))) != 0;
55}
56
57int ev_init(ev_callback input_cb, bool allow_touch_inputs) {
58  g_epoll_fd = epoll_create(MAX_DEVICES + MAX_MISC_FDS);
59  if (g_epoll_fd == -1) {
60    return -1;
61  }
62
63  bool epollctlfail = false;
64  DIR* dir = opendir("/dev/input");
65  if (dir != nullptr) {
66    dirent* de;
67    while ((de = readdir(dir))) {
68      if (strncmp(de->d_name, "event", 5)) continue;
69      int fd = openat(dirfd(dir), de->d_name, O_RDONLY);
70      if (fd == -1) continue;
71
72      // Use unsigned long to match ioctl's parameter type.
73      unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)];  // NOLINT
74
75      // Read the evbits of the input device.
76      if (ioctl(fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
77        close(fd);
78        continue;
79      }
80
81      // We assume that only EV_KEY, EV_REL, and EV_SW event types are ever needed. EV_ABS is also
82      // allowed if allow_touch_inputs is set.
83      if (!test_bit(EV_KEY, ev_bits) && !test_bit(EV_REL, ev_bits) && !test_bit(EV_SW, ev_bits)) {
84        if (!allow_touch_inputs || !test_bit(EV_ABS, ev_bits)) {
85          close(fd);
86          continue;
87        }
88      }
89
90      epoll_event ev;
91      ev.events = EPOLLIN | EPOLLWAKEUP;
92      ev.data.ptr = &ev_fdinfo[ev_count];
93      if (epoll_ctl(g_epoll_fd, EPOLL_CTL_ADD, fd, &ev) == -1) {
94        close(fd);
95        epollctlfail = true;
96        continue;
97      }
98
99      ev_fdinfo[ev_count].fd = fd;
100      ev_fdinfo[ev_count].cb = std::move(input_cb);
101      ev_count++;
102      ev_dev_count++;
103      if (ev_dev_count == MAX_DEVICES) break;
104    }
105
106    closedir(dir);
107  }
108
109  if (epollctlfail && !ev_count) {
110    close(g_epoll_fd);
111    g_epoll_fd = -1;
112    return -1;
113  }
114
115  return 0;
116}
117
118int ev_get_epollfd(void) {
119    return g_epoll_fd;
120}
121
122int ev_add_fd(int fd, ev_callback cb) {
123  if (ev_misc_count == MAX_MISC_FDS || cb == NULL) {
124    return -1;
125  }
126
127  epoll_event ev;
128  ev.events = EPOLLIN | EPOLLWAKEUP;
129  ev.data.ptr = static_cast<void*>(&ev_fdinfo[ev_count]);
130  int ret = epoll_ctl(g_epoll_fd, EPOLL_CTL_ADD, fd, &ev);
131  if (!ret) {
132    ev_fdinfo[ev_count].fd = fd;
133    ev_fdinfo[ev_count].cb = std::move(cb);
134    ev_count++;
135    ev_misc_count++;
136  }
137
138  return ret;
139}
140
141void ev_exit(void) {
142    while (ev_count > 0) {
143        close(ev_fdinfo[--ev_count].fd);
144    }
145    ev_misc_count = 0;
146    ev_dev_count = 0;
147    close(g_epoll_fd);
148}
149
150int ev_wait(int timeout) {
151    npolledevents = epoll_wait(g_epoll_fd, polledevents, ev_count, timeout);
152    if (npolledevents <= 0) {
153        return -1;
154    }
155    return 0;
156}
157
158void ev_dispatch(void) {
159  for (int n = 0; n < npolledevents; n++) {
160    fd_info* fdi = static_cast<fd_info*>(polledevents[n].data.ptr);
161    const ev_callback& cb = fdi->cb;
162    if (cb) {
163      cb(fdi->fd, polledevents[n].events);
164    }
165  }
166}
167
168int ev_get_input(int fd, uint32_t epevents, input_event* ev) {
169    if (epevents & EPOLLIN) {
170        ssize_t r = TEMP_FAILURE_RETRY(read(fd, ev, sizeof(*ev)));
171        if (r == sizeof(*ev)) {
172            return 0;
173        }
174    }
175    return -1;
176}
177
178int ev_sync_key_state(const ev_set_key_callback& set_key_cb) {
179  // Use unsigned long to match ioctl's parameter type.
180  unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)];    // NOLINT
181  unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)];  // NOLINT
182
183  for (size_t i = 0; i < ev_dev_count; ++i) {
184    memset(ev_bits, 0, sizeof(ev_bits));
185    memset(key_bits, 0, sizeof(key_bits));
186
187    if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
188      continue;
189    }
190    if (!test_bit(EV_KEY, ev_bits)) {
191      continue;
192    }
193    if (ioctl(ev_fdinfo[i].fd, EVIOCGKEY(sizeof(key_bits)), key_bits) == -1) {
194      continue;
195    }
196
197    for (int code = 0; code <= KEY_MAX; code++) {
198      if (test_bit(code, key_bits)) {
199        set_key_cb(code, 1);
200      }
201    }
202  }
203
204  return 0;
205}
206
207void ev_iterate_available_keys(const std::function<void(int)>& f) {
208    // Use unsigned long to match ioctl's parameter type.
209    unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)]; // NOLINT
210    unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)]; // NOLINT
211
212    for (size_t i = 0; i < ev_dev_count; ++i) {
213        memset(ev_bits, 0, sizeof(ev_bits));
214        memset(key_bits, 0, sizeof(key_bits));
215
216        // Does this device even have keys?
217        if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
218            continue;
219        }
220        if (!test_bit(EV_KEY, ev_bits)) {
221            continue;
222        }
223
224        int rc = ioctl(ev_fdinfo[i].fd, EVIOCGBIT(EV_KEY, KEY_MAX), key_bits);
225        if (rc == -1) {
226            continue;
227        }
228
229        for (int key_code = 0; key_code <= KEY_MAX; ++key_code) {
230            if (test_bit(key_code, key_bits)) {
231                f(key_code);
232            }
233        }
234    }
235}
236
237void ev_iterate_touch_inputs(const std::function<void(int)>& action) {
238  for (size_t i = 0; i < ev_dev_count; ++i) {
239    // Use unsigned long to match ioctl's parameter type.
240    unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)] = {};  // NOLINT
241    if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
242      continue;
243    }
244    if (!test_bit(EV_ABS, ev_bits)) {
245      continue;
246    }
247
248    unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)] = {};  // NOLINT
249    if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(EV_ABS, KEY_MAX), key_bits) == -1) {
250      continue;
251    }
252
253    for (int key_code = 0; key_code <= KEY_MAX; ++key_code) {
254      if (test_bit(key_code, key_bits)) {
255        action(key_code);
256      }
257    }
258  }
259}
260