1 /*
2  * Copyright (C) 2010 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 <stdlib.h>
20 #include <string.h>
21 #include <sys/stat.h>
22 #include <sys/types.h>
23 #include <linux/keychord.h>
24 #include <unistd.h>
25 
26 #include "init.h"
27 #include "log.h"
28 #include "property_service.h"
29 
30 static struct input_keychord *keychords = 0;
31 static int keychords_count = 0;
32 static int keychords_length = 0;
33 static int keychord_fd = -1;
34 
add_service_keycodes(struct service * svc)35 void add_service_keycodes(struct service *svc)
36 {
37     struct input_keychord *keychord;
38     int i, size;
39 
40     if (svc->keycodes) {
41         /* add a new keychord to the list */
42         size = sizeof(*keychord) + svc->nkeycodes * sizeof(keychord->keycodes[0]);
43         keychords = (input_keychord*) realloc(keychords, keychords_length + size);
44         if (!keychords) {
45             ERROR("could not allocate keychords\n");
46             keychords_length = 0;
47             keychords_count = 0;
48             return;
49         }
50 
51         keychord = (struct input_keychord *)((char *)keychords + keychords_length);
52         keychord->version = KEYCHORD_VERSION;
53         keychord->id = keychords_count + 1;
54         keychord->count = svc->nkeycodes;
55         svc->keychord_id = keychord->id;
56 
57         for (i = 0; i < svc->nkeycodes; i++) {
58             keychord->keycodes[i] = svc->keycodes[i];
59         }
60         keychords_count++;
61         keychords_length += size;
62     }
63 }
64 
handle_keychord()65 static void handle_keychord() {
66     struct service *svc;
67     char adb_enabled[PROP_VALUE_MAX];
68     int ret;
69     __u16 id;
70 
71     // Only handle keychords if adb is enabled.
72     property_get("init.svc.adbd", adb_enabled);
73     ret = read(keychord_fd, &id, sizeof(id));
74     if (ret != sizeof(id)) {
75         ERROR("could not read keychord id\n");
76         return;
77     }
78 
79     if (!strcmp(adb_enabled, "running")) {
80         svc = service_find_by_keychord(id);
81         if (svc) {
82             INFO("Starting service %s from keychord\n", svc->name);
83             service_start(svc, NULL);
84         } else {
85             ERROR("service for keychord %d not found\n", id);
86         }
87     }
88 }
89 
keychord_init()90 void keychord_init() {
91     service_for_each(add_service_keycodes);
92 
93     // Nothing to do if no services require keychords.
94     if (!keychords) {
95         return;
96     }
97 
98     keychord_fd = TEMP_FAILURE_RETRY(open("/dev/keychord", O_RDWR | O_CLOEXEC));
99     if (keychord_fd == -1) {
100         ERROR("could not open /dev/keychord: %s\n", strerror(errno));
101         return;
102     }
103 
104     int ret = write(keychord_fd, keychords, keychords_length);
105     if (ret != keychords_length) {
106         ERROR("could not configure /dev/keychord %d: %s\n", ret, strerror(errno));
107         close(keychord_fd);
108     }
109 
110     free(keychords);
111     keychords = nullptr;
112 
113     register_epoll_handler(keychord_fd, handle_keychord);
114 }
115