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 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 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 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
