btif_config.c revision 47d68ee6229ccec3deeaaf694fa86438d97333a4 
1/******************************************************************************
2 *
3 *  Copyright (C) 2014 Google, Inc.
4 *
5 *  Licensed under the Apache License, Version 2.0 (the "License");
6 *  you may not use this file except in compliance with the License.
7 *  You may obtain a copy of the License at:
8 *
9 *  http://www.apache.org/licenses/LICENSE-2.0
10 *
11 *  Unless required by applicable law or agreed to in writing, software
12 *  distributed under the License is distributed on an "AS IS" BASIS,
13 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 *  See the License for the specific language governing permissions and
15 *  limitations under the License.
16 *
17 ******************************************************************************/
18
19#define LOG_TAG "bt_btif_config"
20
21#include <assert.h>
22#include <ctype.h>
23#include <pthread.h>
24#include <stdio.h>
25#include <string.h>
26
27#include "osi/include/alarm.h"
28#include "btcore/include/bdaddr.h"
29#include "btif_config.h"
30#include "btif_config_transcode.h"
31#include "btif_util.h"
32#include "osi/include/compat.h"
33#include "osi/include/config.h"
34#include "btcore/include/module.h"
35#include "osi/include/osi.h"
36#include "osi/include/log.h"
37
38#include "bt_types.h"
39
40static const char *CONFIG_FILE_PATH = "/data/misc/bluedroid/bt_config.conf";
41static const char *LEGACY_CONFIG_FILE_PATH = "/data/misc/bluedroid/bt_config.xml";
42static const period_ms_t CONFIG_SETTLE_PERIOD_MS = 3000;
43
44static void timer_config_save(void *data);
45
46// TODO(zachoverflow): Move these two functions out, because they are too specific for this file
47// {grumpy-cat/no, monty-python/you-make-me-sad}
48bool btif_get_device_type(const BD_ADDR bd_addr, int *p_device_type)
49{
50    if (p_device_type == NULL)
51        return FALSE;
52
53    bt_bdaddr_t bda;
54    bdcpy(bda.address, bd_addr);
55
56    bdstr_t bd_addr_str;
57    bdaddr_to_string(&bda, bd_addr_str, sizeof(bd_addr_str));
58
59    if (!btif_config_get_int(bd_addr_str, "DevType", p_device_type))
60        return FALSE;
61
62    LOG_DEBUG("%s: Device [%s] type %d", __FUNCTION__, bd_addr_str, *p_device_type);
63    return TRUE;
64}
65
66bool btif_get_address_type(const BD_ADDR bd_addr, int *p_addr_type)
67{
68    if (p_addr_type == NULL)
69        return FALSE;
70
71    bt_bdaddr_t bda;
72    bdcpy(bda.address, bd_addr);
73
74    bdstr_t bd_addr_str;
75    bdaddr_to_string(&bda, bd_addr_str, sizeof(bd_addr_str));
76
77    if (!btif_config_get_int(bd_addr_str, "AddrType", p_addr_type))
78        return FALSE;
79
80    LOG_DEBUG("%s: Device [%s] address type %d", __FUNCTION__, bd_addr_str, *p_addr_type);
81    return TRUE;
82}
83
84static pthread_mutex_t lock;  // protects operations on |config|.
85static config_t *config;
86static alarm_t *alarm_timer;
87
88// Module lifecycle functions
89
90static future_t *init(void) {
91  pthread_mutex_init(&lock, NULL);
92  config = config_new(CONFIG_FILE_PATH);
93  if (!config) {
94    LOG_WARN("%s unable to load config file; attempting to transcode legacy file.", __func__);
95    config = btif_config_transcode(LEGACY_CONFIG_FILE_PATH);
96    if (!config) {
97      LOG_WARN("%s unable to transcode legacy file, starting unconfigured.", __func__);
98      config = config_new_empty();
99      if (!config) {
100        LOG_ERROR("%s unable to allocate a config object.", __func__);
101        goto error;
102      }
103    }
104
105    if (config_save(config, CONFIG_FILE_PATH))
106      unlink(LEGACY_CONFIG_FILE_PATH);
107  }
108
109  // TODO(sharvil): use a non-wake alarm for this once we have
110  // API support for it. There's no need to wake the system to
111  // write back to disk.
112  alarm_timer = alarm_new();
113  if (!alarm_timer) {
114    LOG_ERROR("%s unable to create alarm.", __func__);
115    goto error;
116  }
117
118  return future_new_immediate(FUTURE_SUCCESS);
119
120error:;
121  alarm_free(alarm_timer);
122  config_free(config);
123  pthread_mutex_destroy(&lock);
124  alarm_timer = NULL;
125  config = NULL;
126  return future_new_immediate(FUTURE_FAIL);
127}
128
129static future_t *shut_down(void) {
130  btif_config_flush();
131  return future_new_immediate(FUTURE_SUCCESS);
132}
133
134static future_t *clean_up(void) {
135  btif_config_flush();
136
137  alarm_free(alarm_timer);
138  config_free(config);
139  pthread_mutex_destroy(&lock);
140  alarm_timer = NULL;
141  config = NULL;
142  return future_new_immediate(FUTURE_SUCCESS);
143}
144
145const module_t btif_config_module = {
146  .name = BTIF_CONFIG_MODULE,
147  .init = init,
148  .start_up = NULL,
149  .shut_down = shut_down,
150  .clean_up = clean_up,
151  .dependencies = {
152    NULL
153  }
154};
155
156bool btif_config_has_section(const char *section) {
157  assert(config != NULL);
158  assert(section != NULL);
159
160  pthread_mutex_lock(&lock);
161  bool ret = config_has_section(config, section);
162  pthread_mutex_unlock(&lock);
163
164  return ret;
165}
166
167bool btif_config_exist(const char *section, const char *key) {
168  assert(config != NULL);
169  assert(section != NULL);
170  assert(key != NULL);
171
172  pthread_mutex_lock(&lock);
173  bool ret = config_has_key(config, section, key);
174  pthread_mutex_unlock(&lock);
175
176  return ret;
177}
178
179bool btif_config_get_int(const char *section, const char *key, int *value) {
180  assert(config != NULL);
181  assert(section != NULL);
182  assert(key != NULL);
183  assert(value != NULL);
184
185  pthread_mutex_lock(&lock);
186  bool ret = config_has_key(config, section, key);
187  if (ret)
188    *value = config_get_int(config, section, key, *value);
189  pthread_mutex_unlock(&lock);
190
191  return ret;
192}
193
194bool btif_config_set_int(const char *section, const char *key, int value) {
195  assert(config != NULL);
196  assert(section != NULL);
197  assert(key != NULL);
198
199  pthread_mutex_lock(&lock);
200  config_set_int(config, section, key, value);
201  pthread_mutex_unlock(&lock);
202
203  return true;
204}
205
206bool btif_config_get_str(const char *section, const char *key, char *value, int *size_bytes) {
207  assert(config != NULL);
208  assert(section != NULL);
209  assert(key != NULL);
210  assert(value != NULL);
211  assert(size_bytes != NULL);
212
213  pthread_mutex_lock(&lock);
214  const char *stored_value = config_get_string(config, section, key, NULL);
215  pthread_mutex_unlock(&lock);
216
217  if (!stored_value)
218    return false;
219
220  strlcpy(value, stored_value, *size_bytes);
221  *size_bytes = strlen(value) + 1;
222
223  return true;
224}
225
226bool btif_config_set_str(const char *section, const char *key, const char *value) {
227  assert(config != NULL);
228  assert(section != NULL);
229  assert(key != NULL);
230  assert(value != NULL);
231
232  pthread_mutex_lock(&lock);
233  config_set_string(config, section, key, value);
234  pthread_mutex_unlock(&lock);
235
236  return true;
237}
238
239bool btif_config_get_bin(const char *section, const char *key, uint8_t *value, size_t *length) {
240  assert(config != NULL);
241  assert(section != NULL);
242  assert(key != NULL);
243  assert(value != NULL);
244  assert(length != NULL);
245
246  pthread_mutex_lock(&lock);
247  const char *value_str = config_get_string(config, section, key, NULL);
248  pthread_mutex_unlock(&lock);
249
250  if (!value_str)
251    return false;
252
253  size_t value_len = strlen(value_str);
254  if ((value_len % 2) != 0 || *length < (value_len / 2))
255    return false;
256
257  for (size_t i = 0; i < value_len; ++i)
258    if (!isxdigit(value_str[i]))
259      return false;
260
261  for (*length = 0; *value_str; value_str += 2, *length += 1)
262    sscanf(value_str, "%02hhx", &value[*length]);
263
264  return true;
265}
266
267size_t btif_config_get_bin_length(const char *section, const char *key) {
268  assert(config != NULL);
269  assert(section != NULL);
270  assert(key != NULL);
271
272  pthread_mutex_lock(&lock);
273  const char *value_str = config_get_string(config, section, key, NULL);
274  pthread_mutex_unlock(&lock);
275
276  if (!value_str)
277    return 0;
278
279  size_t value_len = strlen(value_str);
280  return ((value_len % 2) != 0) ? 0 : (value_len / 2);
281}
282
283bool btif_config_set_bin(const char *section, const char *key, const uint8_t *value, size_t length) {
284  static const char *lookup = "0123456789abcdef";
285
286  assert(config != NULL);
287  assert(section != NULL);
288  assert(key != NULL);
289  assert(value != NULL);
290
291  char *str = (char *)calloc(length * 2 + 1, 1);
292  if (!str)
293    return false;
294
295  for (size_t i = 0; i < length; ++i) {
296    str[(i * 2) + 0] = lookup[(value[i] >> 4) & 0x0F];
297    str[(i * 2) + 1] = lookup[(value[i] >> 0) & 0x0F];
298  }
299
300  pthread_mutex_lock(&lock);
301  config_set_string(config, section, key, str);
302  pthread_mutex_unlock(&lock);
303
304  free(str);
305  return true;
306}
307
308const btif_config_section_iter_t *btif_config_section_begin(void) {
309  assert(config != NULL);
310  return (const btif_config_section_iter_t *)config_section_begin(config);
311}
312
313const btif_config_section_iter_t *btif_config_section_end(void) {
314  assert(config != NULL);
315  return (const btif_config_section_iter_t *)config_section_end(config);
316}
317
318const btif_config_section_iter_t *btif_config_section_next(const btif_config_section_iter_t *section) {
319  assert(config != NULL);
320  assert(section != NULL);
321  return (const btif_config_section_iter_t *)config_section_next((const config_section_node_t *)section);
322}
323
324const char *btif_config_section_name(const btif_config_section_iter_t *section) {
325  assert(config != NULL);
326  assert(section != NULL);
327  return config_section_name((const config_section_node_t *)section);
328}
329
330bool btif_config_remove(const char *section, const char *key) {
331  assert(config != NULL);
332  assert(section != NULL);
333  assert(key != NULL);
334
335  pthread_mutex_lock(&lock);
336  bool ret = config_remove_key(config, section, key);
337  pthread_mutex_unlock(&lock);
338
339  return ret;
340}
341
342void btif_config_save(void) {
343  assert(alarm_timer != NULL);
344  assert(config != NULL);
345
346  alarm_set(alarm_timer, CONFIG_SETTLE_PERIOD_MS, timer_config_save, NULL);
347}
348
349void btif_config_flush(void) {
350  assert(config != NULL);
351  assert(alarm_timer != NULL);
352
353  alarm_cancel(alarm_timer);
354
355  pthread_mutex_lock(&lock);
356  config_save(config, CONFIG_FILE_PATH);
357  pthread_mutex_unlock(&lock);
358}
359
360static void timer_config_save(UNUSED_ATTR void *data) {
361  assert(config != NULL);
362  assert(alarm_timer != NULL);
363
364  // Garbage collection process: the config file accumulates
365  // cached information about remote devices during regular
366  // inquiry scans. We remove some of these junk entries
367  // so the file doesn't grow indefinitely. We have to take care
368  // to make sure we don't remove information about bonded
369  // devices (hence the check for link keys).
370  static const size_t CACHE_MAX = 256;
371  const char *keys[CACHE_MAX];
372  size_t num_keys = 0;
373  size_t total_candidates = 0;
374
375  pthread_mutex_lock(&lock);
376  for (const config_section_node_t *snode = config_section_begin(config); snode != config_section_end(config); snode = config_section_next(snode)) {
377    const char *section = config_section_name(snode);
378    if (!string_is_bdaddr(section))
379      continue;
380
381    if (config_has_key(config, section, "LinkKey") ||
382        config_has_key(config, section, "LE_KEY_PENC") ||
383        config_has_key(config, section, "LE_KEY_PID") ||
384        config_has_key(config, section, "LE_KEY_PCSRK") ||
385        config_has_key(config, section, "LE_KEY_LENC") ||
386        config_has_key(config, section, "LE_KEY_LCSRK"))
387      continue;
388
389    if (num_keys < CACHE_MAX)
390      keys[num_keys++] = section;
391
392    ++total_candidates;
393  }
394
395  if (total_candidates > CACHE_MAX * 2)
396    while (num_keys > 0)
397      config_remove_section(config, keys[--num_keys]);
398
399  config_save(config, CONFIG_FILE_PATH);
400  pthread_mutex_unlock(&lock);
401}
402