1 //
2 // Copyright 2016 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 "bluetooth_address.h"
18
19 #include <android-base/logging.h>
20 #include <cutils/properties.h>
21 #include <fcntl.h>
22 #include <utils/Log.h>
23
24 namespace android {
25 namespace hardware {
26 namespace bluetooth {
27 namespace V1_0 {
28 namespace implementation {
29
bytes_to_string(const uint8_t * addr,char * addr_str)30 void BluetoothAddress::bytes_to_string(const uint8_t* addr, char* addr_str) {
31 sprintf(addr_str, "%02x:%02x:%02x:%02x:%02x:%02x", addr[0], addr[1], addr[2],
32 addr[3], addr[4], addr[5]);
33 }
34
string_to_bytes(const char * addr_str,uint8_t * addr)35 bool BluetoothAddress::string_to_bytes(const char* addr_str, uint8_t* addr) {
36 if (addr_str == NULL) return false;
37 if (strnlen(addr_str, kStringLength) != kStringLength) return false;
38 unsigned char trailing_char = '\0';
39
40 return (sscanf(addr_str, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx%1c",
41 &addr[0], &addr[1], &addr[2], &addr[3], &addr[4], &addr[5],
42 &trailing_char) == kBytes);
43 }
44
get_local_address(uint8_t * local_addr)45 bool BluetoothAddress::get_local_address(uint8_t* local_addr) {
46 char property[PROPERTY_VALUE_MAX] = {0};
47 bool valid_bda = false;
48
49 // Get local bdaddr storage path from a system property.
50 if (property_get(PROPERTY_BT_BDADDR_PATH, property, NULL)) {
51 int addr_fd;
52
53 ALOGD("%s: Trying %s", __func__, property);
54
55 addr_fd = open(property, O_RDONLY);
56 if (addr_fd != -1) {
57 int bytes_read = read(addr_fd, property, kStringLength);
58 CHECK(bytes_read == kStringLength);
59 close(addr_fd);
60
61 // Null terminate the string.
62 property[kStringLength] = '\0';
63
64 // If the address is not all zeros, then use it.
65 const uint8_t zero_bdaddr[kBytes] = {0, 0, 0, 0, 0, 0};
66 if ((string_to_bytes(property, local_addr)) &&
67 (memcmp(local_addr, zero_bdaddr, kBytes) != 0)) {
68 valid_bda = true;
69 ALOGD("%s: Got Factory BDA %s", __func__, property);
70 }
71 }
72 }
73
74 // No BDADDR found in the file. Look for BDA in a factory property.
75 if (!valid_bda && property_get(FACTORY_BDADDR_PROPERTY, property, NULL) &&
76 string_to_bytes(property, local_addr)) {
77 valid_bda = true;
78 }
79
80 // No factory BDADDR found. Look for a previously stored BDA.
81 if (!valid_bda && property_get(PERSIST_BDADDR_PROPERTY, property, NULL) &&
82 string_to_bytes(property, local_addr)) {
83 valid_bda = true;
84 }
85
86 /* Generate new BDA if necessary */
87 if (!valid_bda) {
88 char bdstr[kStringLength + 1];
89
90 /* No autogen BDA. Generate one now. */
91 local_addr[0] = 0x22;
92 local_addr[1] = 0x22;
93 local_addr[2] = (uint8_t)rand();
94 local_addr[3] = (uint8_t)rand();
95 local_addr[4] = (uint8_t)rand();
96 local_addr[5] = (uint8_t)rand();
97
98 /* Convert to ascii, and store as a persistent property */
99 bytes_to_string(local_addr, bdstr);
100
101 ALOGE("%s: No preset BDA! Generating BDA: %s for prop %s", __func__,
102 (char*)bdstr, PERSIST_BDADDR_PROPERTY);
103 ALOGE("%s: This is a bug in the platform! Please fix!", __func__);
104
105 if (property_set(PERSIST_BDADDR_PROPERTY, (char*)bdstr) < 0) {
106 ALOGE("%s: Failed to set random BDA in prop %s", __func__,
107 PERSIST_BDADDR_PROPERTY);
108 valid_bda = false;
109 } else {
110 valid_bda = true;
111 }
112 }
113
114 return valid_bda;
115 }
116
117 } // namespace implementation
118 } // namespace V1_0
119 } // namespace bluetooth
120 } // namespace hardware
121 } // namespace android
122