keychords.c revision ed8a7d84428ec945c48b6b53dc5a3a18fabaf683 
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 <sys/stat.h>
21#include <sys/types.h>
22#include <linux/keychord.h>
23
24#include "init.h"
25#include "log.h"
26#include "property_service.h"
27
28static struct input_keychord *keychords = 0;
29static int keychords_count = 0;
30static int keychords_length = 0;
31static int keychord_fd = -1;
32
33void add_service_keycodes(struct service *svc)
34{
35    struct input_keychord *keychord;
36    int i, size;
37
38    if (svc->keycodes) {
39        /* add a new keychord to the list */
40        size = sizeof(*keychord) + svc->nkeycodes * sizeof(keychord->keycodes[0]);
41        keychords = realloc(keychords, keychords_length + size);
42        if (!keychords) {
43            ERROR("could not allocate keychords\n");
44            keychords_length = 0;
45            keychords_count = 0;
46            return;
47        }
48
49        keychord = (struct input_keychord *)((char *)keychords + keychords_length);
50        keychord->version = KEYCHORD_VERSION;
51        keychord->id = keychords_count + 1;
52        keychord->count = svc->nkeycodes;
53        svc->keychord_id = keychord->id;
54
55        for (i = 0; i < svc->nkeycodes; i++) {
56            keychord->keycodes[i] = svc->keycodes[i];
57        }
58        keychords_count++;
59        keychords_length += size;
60    }
61}
62
63void keychord_init()
64{
65    int fd, ret;
66
67    service_for_each(add_service_keycodes);
68
69    /* nothing to do if no services require keychords */
70    if (!keychords)
71        return;
72
73    fd = open("/dev/keychord", O_RDWR);
74    if (fd < 0) {
75        ERROR("could not open /dev/keychord\n");
76        return;
77    }
78    fcntl(fd, F_SETFD, FD_CLOEXEC);
79
80    ret = write(fd, keychords, keychords_length);
81    if (ret != keychords_length) {
82        ERROR("could not configure /dev/keychord %d (%d)\n", ret, errno);
83        close(fd);
84        fd = -1;
85    }
86
87    free(keychords);
88    keychords = 0;
89
90    keychord_fd = fd;
91}
92
93void handle_keychord()
94{
95    struct service *svc;
96    const char* debuggable;
97    const char* adb_enabled;
98    int ret;
99    __u16 id;
100
101    // only handle keychords if ro.debuggable is set or adb is enabled.
102    // the logic here is that bugreports should be enabled in userdebug or eng builds
103    // and on user builds for users that are developers.
104    debuggable = property_get("ro.debuggable");
105    adb_enabled = property_get("init.svc.adbd");
106    if ((debuggable && !strcmp(debuggable, "1")) ||
107        (adb_enabled && !strcmp(adb_enabled, "running"))) {
108        ret = read(keychord_fd, &id, sizeof(id));
109        if (ret != sizeof(id)) {
110            ERROR("could not read keychord id\n");
111            return;
112        }
113
114        svc = service_find_by_keychord(id);
115        if (svc) {
116            INFO("starting service %s from keychord\n", svc->name);
117            service_start(svc, NULL);
118        } else {
119            ERROR("service for keychord %d not found\n", id);
120        }
121    }
122}
123
124int get_keychord_fd()
125{
126    return keychord_fd;
127}
128