1 /*
2  * Copyright (C) 2011 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 <errno.h>
18 #include <fcntl.h>
19 #include <linux/input.h>
20 #include <pthread.h>
21 #include <stdarg.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <sys/stat.h>
26 #include <sys/time.h>
27 #include <sys/types.h>
28 #include <time.h>
29 #include <unistd.h>
30 
31 #include <cutils/properties.h>
32 #include <cutils/android_reboot.h>
33 
34 #include "common.h"
35 #include "roots.h"
36 #include "device.h"
37 #include "minui/minui.h"
38 #include "screen_ui.h"
39 #include "ui.h"
40 
41 #define UI_WAIT_KEY_TIMEOUT_SEC    120
42 
RecoveryUI()43 RecoveryUI::RecoveryUI()
44         : key_queue_len(0),
45           key_last_down(-1),
46           key_long_press(false),
47           key_down_count(0),
48           enable_reboot(true),
49           consecutive_power_keys(0),
50           last_key(-1),
51           has_power_key(false),
52           has_up_key(false),
53           has_down_key(false) {
54     pthread_mutex_init(&key_queue_mutex, nullptr);
55     pthread_cond_init(&key_queue_cond, nullptr);
56     memset(key_pressed, 0, sizeof(key_pressed));
57 }
58 
OnKeyDetected(int key_code)59 void RecoveryUI::OnKeyDetected(int key_code) {
60     if (key_code == KEY_POWER) {
61         has_power_key = true;
62     } else if (key_code == KEY_DOWN || key_code == KEY_VOLUMEDOWN) {
63         has_down_key = true;
64     } else if (key_code == KEY_UP || key_code == KEY_VOLUMEUP) {
65         has_up_key = true;
66     }
67 }
68 
InputCallback(int fd,uint32_t epevents,void * data)69 int RecoveryUI::InputCallback(int fd, uint32_t epevents, void* data) {
70     return reinterpret_cast<RecoveryUI*>(data)->OnInputEvent(fd, epevents);
71 }
72 
73 // Reads input events, handles special hot keys, and adds to the key queue.
InputThreadLoop(void *)74 static void* InputThreadLoop(void*) {
75     while (true) {
76         if (!ev_wait(-1)) {
77             ev_dispatch();
78         }
79     }
80     return nullptr;
81 }
82 
Init()83 void RecoveryUI::Init() {
84     ev_init(InputCallback, this);
85 
86     ev_iterate_available_keys(std::bind(&RecoveryUI::OnKeyDetected, this, std::placeholders::_1));
87 
88     pthread_create(&input_thread_, nullptr, InputThreadLoop, nullptr);
89 }
90 
OnInputEvent(int fd,uint32_t epevents)91 int RecoveryUI::OnInputEvent(int fd, uint32_t epevents) {
92     struct input_event ev;
93     if (ev_get_input(fd, epevents, &ev) == -1) {
94         return -1;
95     }
96 
97     if (ev.type == EV_SYN) {
98         return 0;
99     } else if (ev.type == EV_REL) {
100         if (ev.code == REL_Y) {
101             // accumulate the up or down motion reported by
102             // the trackball.  When it exceeds a threshold
103             // (positive or negative), fake an up/down
104             // key event.
105             rel_sum += ev.value;
106             if (rel_sum > 3) {
107                 ProcessKey(KEY_DOWN, 1);   // press down key
108                 ProcessKey(KEY_DOWN, 0);   // and release it
109                 rel_sum = 0;
110             } else if (rel_sum < -3) {
111                 ProcessKey(KEY_UP, 1);     // press up key
112                 ProcessKey(KEY_UP, 0);     // and release it
113                 rel_sum = 0;
114             }
115         }
116     } else {
117         rel_sum = 0;
118     }
119 
120     if (ev.type == EV_KEY && ev.code <= KEY_MAX) {
121         ProcessKey(ev.code, ev.value);
122     }
123 
124     return 0;
125 }
126 
127 // Process a key-up or -down event.  A key is "registered" when it is
128 // pressed and then released, with no other keypresses or releases in
129 // between.  Registered keys are passed to CheckKey() to see if it
130 // should trigger a visibility toggle, an immediate reboot, or be
131 // queued to be processed next time the foreground thread wants a key
132 // (eg, for the menu).
133 //
134 // We also keep track of which keys are currently down so that
135 // CheckKey can call IsKeyPressed to see what other keys are held when
136 // a key is registered.
137 //
138 // updown == 1 for key down events; 0 for key up events
ProcessKey(int key_code,int updown)139 void RecoveryUI::ProcessKey(int key_code, int updown) {
140     bool register_key = false;
141     bool long_press = false;
142     bool reboot_enabled;
143 
144     pthread_mutex_lock(&key_queue_mutex);
145     key_pressed[key_code] = updown;
146     if (updown) {
147         ++key_down_count;
148         key_last_down = key_code;
149         key_long_press = false;
150         key_timer_t* info = new key_timer_t;
151         info->ui = this;
152         info->key_code = key_code;
153         info->count = key_down_count;
154         pthread_t thread;
155         pthread_create(&thread, nullptr, &RecoveryUI::time_key_helper, info);
156         pthread_detach(thread);
157     } else {
158         if (key_last_down == key_code) {
159             long_press = key_long_press;
160             register_key = true;
161         }
162         key_last_down = -1;
163     }
164     reboot_enabled = enable_reboot;
165     pthread_mutex_unlock(&key_queue_mutex);
166 
167     if (register_key) {
168         switch (CheckKey(key_code, long_press)) {
169           case RecoveryUI::IGNORE:
170             break;
171 
172           case RecoveryUI::TOGGLE:
173             ShowText(!IsTextVisible());
174             break;
175 
176           case RecoveryUI::REBOOT:
177             if (reboot_enabled) {
178                 property_set(ANDROID_RB_PROPERTY, "reboot,");
179                 while (true) { pause(); }
180             }
181             break;
182 
183           case RecoveryUI::ENQUEUE:
184             EnqueueKey(key_code);
185             break;
186         }
187     }
188 }
189 
time_key_helper(void * cookie)190 void* RecoveryUI::time_key_helper(void* cookie) {
191     key_timer_t* info = (key_timer_t*) cookie;
192     info->ui->time_key(info->key_code, info->count);
193     delete info;
194     return nullptr;
195 }
196 
time_key(int key_code,int count)197 void RecoveryUI::time_key(int key_code, int count) {
198     usleep(750000);  // 750 ms == "long"
199     bool long_press = false;
200     pthread_mutex_lock(&key_queue_mutex);
201     if (key_last_down == key_code && key_down_count == count) {
202         long_press = key_long_press = true;
203     }
204     pthread_mutex_unlock(&key_queue_mutex);
205     if (long_press) KeyLongPress(key_code);
206 }
207 
EnqueueKey(int key_code)208 void RecoveryUI::EnqueueKey(int key_code) {
209     pthread_mutex_lock(&key_queue_mutex);
210     const int queue_max = sizeof(key_queue) / sizeof(key_queue[0]);
211     if (key_queue_len < queue_max) {
212         key_queue[key_queue_len++] = key_code;
213         pthread_cond_signal(&key_queue_cond);
214     }
215     pthread_mutex_unlock(&key_queue_mutex);
216 }
217 
WaitKey()218 int RecoveryUI::WaitKey() {
219     pthread_mutex_lock(&key_queue_mutex);
220 
221     // Time out after UI_WAIT_KEY_TIMEOUT_SEC, unless a USB cable is
222     // plugged in.
223     do {
224         struct timeval now;
225         struct timespec timeout;
226         gettimeofday(&now, nullptr);
227         timeout.tv_sec = now.tv_sec;
228         timeout.tv_nsec = now.tv_usec * 1000;
229         timeout.tv_sec += UI_WAIT_KEY_TIMEOUT_SEC;
230 
231         int rc = 0;
232         while (key_queue_len == 0 && rc != ETIMEDOUT) {
233             rc = pthread_cond_timedwait(&key_queue_cond, &key_queue_mutex, &timeout);
234         }
235     } while (IsUsbConnected() && key_queue_len == 0);
236 
237     int key = -1;
238     if (key_queue_len > 0) {
239         key = key_queue[0];
240         memcpy(&key_queue[0], &key_queue[1], sizeof(int) * --key_queue_len);
241     }
242     pthread_mutex_unlock(&key_queue_mutex);
243     return key;
244 }
245 
IsUsbConnected()246 bool RecoveryUI::IsUsbConnected() {
247     int fd = open("/sys/class/android_usb/android0/state", O_RDONLY);
248     if (fd < 0) {
249         printf("failed to open /sys/class/android_usb/android0/state: %s\n",
250                strerror(errno));
251         return 0;
252     }
253 
254     char buf;
255     // USB is connected if android_usb state is CONNECTED or CONFIGURED.
256     int connected = (TEMP_FAILURE_RETRY(read(fd, &buf, 1)) == 1) && (buf == 'C');
257     if (close(fd) < 0) {
258         printf("failed to close /sys/class/android_usb/android0/state: %s\n",
259                strerror(errno));
260     }
261     return connected;
262 }
263 
IsKeyPressed(int key)264 bool RecoveryUI::IsKeyPressed(int key) {
265     pthread_mutex_lock(&key_queue_mutex);
266     int pressed = key_pressed[key];
267     pthread_mutex_unlock(&key_queue_mutex);
268     return pressed;
269 }
270 
IsLongPress()271 bool RecoveryUI::IsLongPress() {
272     pthread_mutex_lock(&key_queue_mutex);
273     bool result = key_long_press;
274     pthread_mutex_unlock(&key_queue_mutex);
275     return result;
276 }
277 
HasThreeButtons()278 bool RecoveryUI::HasThreeButtons() {
279     return has_power_key && has_up_key && has_down_key;
280 }
281 
FlushKeys()282 void RecoveryUI::FlushKeys() {
283     pthread_mutex_lock(&key_queue_mutex);
284     key_queue_len = 0;
285     pthread_mutex_unlock(&key_queue_mutex);
286 }
287 
CheckKey(int key,bool is_long_press)288 RecoveryUI::KeyAction RecoveryUI::CheckKey(int key, bool is_long_press) {
289     pthread_mutex_lock(&key_queue_mutex);
290     key_long_press = false;
291     pthread_mutex_unlock(&key_queue_mutex);
292 
293     // If we have power and volume up keys, that chord is the signal to toggle the text display.
294     if (HasThreeButtons()) {
295         if (key == KEY_VOLUMEUP && IsKeyPressed(KEY_POWER)) {
296             return TOGGLE;
297         }
298     } else {
299         // Otherwise long press of any button toggles to the text display,
300         // and there's no way to toggle back (but that's pretty useless anyway).
301         if (is_long_press && !IsTextVisible()) {
302             return TOGGLE;
303         }
304 
305         // Also, for button-limited devices, a long press is translated to KEY_ENTER.
306         if (is_long_press && IsTextVisible()) {
307             EnqueueKey(KEY_ENTER);
308             return IGNORE;
309         }
310     }
311 
312     // Press power seven times in a row to reboot.
313     if (key == KEY_POWER) {
314         pthread_mutex_lock(&key_queue_mutex);
315         bool reboot_enabled = enable_reboot;
316         pthread_mutex_unlock(&key_queue_mutex);
317 
318         if (reboot_enabled) {
319             ++consecutive_power_keys;
320             if (consecutive_power_keys >= 7) {
321                 return REBOOT;
322             }
323         }
324     } else {
325         consecutive_power_keys = 0;
326     }
327 
328     last_key = key;
329     return IsTextVisible() ? ENQUEUE : IGNORE;
330 }
331 
KeyLongPress(int)332 void RecoveryUI::KeyLongPress(int) {
333 }
334 
SetEnableReboot(bool enabled)335 void RecoveryUI::SetEnableReboot(bool enabled) {
336     pthread_mutex_lock(&key_queue_mutex);
337     enable_reboot = enabled;
338     pthread_mutex_unlock(&key_queue_mutex);
339 }
340