keychords.c revision b93e5812faffd3b6c5fb349072413aace31918d8 
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
30static struct input_keychord *keychords = 0;
31static int keychords_count = 0;
32static int keychords_length = 0;
33static int keychord_fd = -1;
34
35void 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 = 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
65void keychord_init()
66{
67    int fd, ret;
68
69    service_for_each(add_service_keycodes);
70
71    /* nothing to do if no services require keychords */
72    if (!keychords)
73        return;
74
75    fd = open("/dev/keychord", O_RDWR);
76    if (fd < 0) {
77        ERROR("could not open /dev/keychord\n");
78        return;
79    }
80    fcntl(fd, F_SETFD, FD_CLOEXEC);
81
82    ret = write(fd, keychords, keychords_length);
83    if (ret != keychords_length) {
84        ERROR("could not configure /dev/keychord %d (%d)\n", ret, errno);
85        close(fd);
86        fd = -1;
87    }
88
89    free(keychords);
90    keychords = 0;
91
92    keychord_fd = fd;
93}
94
95void handle_keychord()
96{
97    struct service *svc;
98    const char* debuggable;
99    const char* adb_enabled;
100    int ret;
101    __u16 id;
102
103    // only handle keychords if ro.debuggable is set or adb is enabled.
104    // the logic here is that bugreports should be enabled in userdebug or eng builds
105    // and on user builds for users that are developers.
106    debuggable = property_get("ro.debuggable");
107    adb_enabled = property_get("init.svc.adbd");
108    if ((debuggable && !strcmp(debuggable, "1")) ||
109        (adb_enabled && !strcmp(adb_enabled, "running"))) {
110        ret = read(keychord_fd, &id, sizeof(id));
111        if (ret != sizeof(id)) {
112            ERROR("could not read keychord id\n");
113            return;
114        }
115
116        svc = service_find_by_keychord(id);
117        if (svc) {
118            INFO("starting service %s from keychord\n", svc->name);
119            service_start(svc, NULL);
120        } else {
121            ERROR("service for keychord %d not found\n", id);
122        }
123    }
124}
125
126int get_keychord_fd()
127{
128    return keychord_fd;
129}
130