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 <fcntl.h>
19 #include <linux/input.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <sys/epoll.h>
24 #include <sys/ioctl.h>
25 #include <unistd.h>
26 
27 #include <functional>
28 
29 #include "minui/minui.h"
30 
31 #define MAX_DEVICES 16
32 #define MAX_MISC_FDS 16
33 
34 #define BITS_PER_LONG (sizeof(unsigned long) * 8)
35 #define BITS_TO_LONGS(x) (((x) + BITS_PER_LONG - 1) / BITS_PER_LONG)
36 
37 struct fd_info {
38   int fd;
39   ev_callback cb;
40 };
41 
42 static int g_epoll_fd;
43 static epoll_event polledevents[MAX_DEVICES + MAX_MISC_FDS];
44 static int npolledevents;
45 
46 static fd_info ev_fdinfo[MAX_DEVICES + MAX_MISC_FDS];
47 
48 static unsigned ev_count = 0;
49 static unsigned ev_dev_count = 0;
50 static unsigned ev_misc_count = 0;
51 
test_bit(size_t bit,unsigned long * array)52 static bool test_bit(size_t bit, unsigned long* array) { // NOLINT
53     return (array[bit/BITS_PER_LONG] & (1UL << (bit % BITS_PER_LONG))) != 0;
54 }
55 
ev_init(ev_callback input_cb)56 int ev_init(ev_callback input_cb) {
57   bool epollctlfail = false;
58 
59   g_epoll_fd = epoll_create(MAX_DEVICES + MAX_MISC_FDS);
60   if (g_epoll_fd == -1) {
61     return -1;
62   }
63 
64   DIR* dir = opendir("/dev/input");
65   if (dir != NULL) {
66     dirent* de;
67     while ((de = readdir(dir))) {
68       // Use unsigned long to match ioctl's parameter type.
69       unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)];  // NOLINT
70 
71       //            fprintf(stderr,"/dev/input/%s\n", de->d_name);
72       if (strncmp(de->d_name, "event", 5)) continue;
73       int fd = openat(dirfd(dir), de->d_name, O_RDONLY);
74       if (fd == -1) continue;
75 
76       // Read the evbits of the input device.
77       if (ioctl(fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
78         close(fd);
79         continue;
80       }
81 
82       // We assume that only EV_KEY, EV_REL, and EV_SW event types are ever needed.
83       if (!test_bit(EV_KEY, ev_bits) && !test_bit(EV_REL, ev_bits) && !test_bit(EV_SW, ev_bits)) {
84         close(fd);
85         continue;
86       }
87 
88       epoll_event ev;
89       ev.events = EPOLLIN | EPOLLWAKEUP;
90       ev.data.ptr = &ev_fdinfo[ev_count];
91       if (epoll_ctl(g_epoll_fd, EPOLL_CTL_ADD, fd, &ev) == -1) {
92         close(fd);
93         epollctlfail = true;
94         continue;
95       }
96 
97       ev_fdinfo[ev_count].fd = fd;
98       ev_fdinfo[ev_count].cb = std::move(input_cb);
99       ev_count++;
100       ev_dev_count++;
101       if (ev_dev_count == MAX_DEVICES) break;
102     }
103 
104     closedir(dir);
105   }
106 
107   if (epollctlfail && !ev_count) {
108     close(g_epoll_fd);
109     g_epoll_fd = -1;
110     return -1;
111   }
112 
113   return 0;
114 }
115 
ev_get_epollfd(void)116 int ev_get_epollfd(void) {
117     return g_epoll_fd;
118 }
119 
ev_add_fd(int fd,ev_callback cb)120 int ev_add_fd(int fd, ev_callback cb) {
121   if (ev_misc_count == MAX_MISC_FDS || cb == NULL) {
122     return -1;
123   }
124 
125   epoll_event ev;
126   ev.events = EPOLLIN | EPOLLWAKEUP;
127   ev.data.ptr = static_cast<void*>(&ev_fdinfo[ev_count]);
128   int ret = epoll_ctl(g_epoll_fd, EPOLL_CTL_ADD, fd, &ev);
129   if (!ret) {
130     ev_fdinfo[ev_count].fd = fd;
131     ev_fdinfo[ev_count].cb = std::move(cb);
132     ev_count++;
133     ev_misc_count++;
134   }
135 
136   return ret;
137 }
138 
ev_exit(void)139 void ev_exit(void) {
140     while (ev_count > 0) {
141         close(ev_fdinfo[--ev_count].fd);
142     }
143     ev_misc_count = 0;
144     ev_dev_count = 0;
145     close(g_epoll_fd);
146 }
147 
ev_wait(int timeout)148 int ev_wait(int timeout) {
149     npolledevents = epoll_wait(g_epoll_fd, polledevents, ev_count, timeout);
150     if (npolledevents <= 0) {
151         return -1;
152     }
153     return 0;
154 }
155 
ev_dispatch(void)156 void ev_dispatch(void) {
157   for (int n = 0; n < npolledevents; n++) {
158     fd_info* fdi = static_cast<fd_info*>(polledevents[n].data.ptr);
159     const ev_callback& cb = fdi->cb;
160     if (cb) {
161       cb(fdi->fd, polledevents[n].events);
162     }
163   }
164 }
165 
ev_get_input(int fd,uint32_t epevents,input_event * ev)166 int ev_get_input(int fd, uint32_t epevents, input_event* ev) {
167     if (epevents & EPOLLIN) {
168         ssize_t r = TEMP_FAILURE_RETRY(read(fd, ev, sizeof(*ev)));
169         if (r == sizeof(*ev)) {
170             return 0;
171         }
172     }
173     return -1;
174 }
175 
ev_sync_key_state(const ev_set_key_callback & set_key_cb)176 int ev_sync_key_state(const ev_set_key_callback& set_key_cb) {
177   // Use unsigned long to match ioctl's parameter type.
178   unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)];    // NOLINT
179   unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)];  // NOLINT
180 
181   for (size_t i = 0; i < ev_dev_count; ++i) {
182     memset(ev_bits, 0, sizeof(ev_bits));
183     memset(key_bits, 0, sizeof(key_bits));
184 
185     if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
186       continue;
187     }
188     if (!test_bit(EV_KEY, ev_bits)) {
189       continue;
190     }
191     if (ioctl(ev_fdinfo[i].fd, EVIOCGKEY(sizeof(key_bits)), key_bits) == -1) {
192       continue;
193     }
194 
195     for (int code = 0; code <= KEY_MAX; code++) {
196       if (test_bit(code, key_bits)) {
197         set_key_cb(code, 1);
198       }
199     }
200   }
201 
202   return 0;
203 }
204 
ev_iterate_available_keys(const std::function<void (int)> & f)205 void ev_iterate_available_keys(const std::function<void(int)>& f) {
206     // Use unsigned long to match ioctl's parameter type.
207     unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)]; // NOLINT
208     unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)]; // NOLINT
209 
210     for (size_t i = 0; i < ev_dev_count; ++i) {
211         memset(ev_bits, 0, sizeof(ev_bits));
212         memset(key_bits, 0, sizeof(key_bits));
213 
214         // Does this device even have keys?
215         if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
216             continue;
217         }
218         if (!test_bit(EV_KEY, ev_bits)) {
219             continue;
220         }
221 
222         int rc = ioctl(ev_fdinfo[i].fd, EVIOCGBIT(EV_KEY, KEY_MAX), key_bits);
223         if (rc == -1) {
224             continue;
225         }
226 
227         for (int key_code = 0; key_code <= KEY_MAX; ++key_code) {
228             if (test_bit(key_code, key_bits)) {
229                 f(key_code);
230             }
231         }
232     }
233 }
234