| #!/usr/bin/python2.7 |
| |
| '''This script generates the wifi and bluetooth MAC addresses assigned to a |
| board, given the MAC address of it's primary ethernet interface. It's primary |
| purpose is to store the MAC addresses in files on the root filesystem after |
| system first start because we cannot burn these addresses into the peripherals, |
| other than the ethernet PHY. |
| |
| This script only works in the case where the MAC addresses have been allocated |
| in a monotonically adjacent style for all devices, and that wifi/bluetooth |
| follows the ethernet MAC in series. |
| ''' |
| |
| |
| import struct |
| import sys |
| |
| |
| MAC_VENDOR_PREFIX_STR = '70:20:84' |
| |
| BD_ADDR_PATH = '/etc/bluetooth/.bt_nv.bin' |
| WIFI_ADDR_PATH = '/lib/firmware/wlan/wlan_mac.bin' |
| |
| BD_NVITEM = 0x02 |
| BD_RDWR_PROT = 0x00 |
| BD_NVITEM_SIZE = 0x06 |
| BD_ADDR_HEADER_STRUCT = r'BBB' |
| BD_ADDR_MAC_STRUCT = r'BBBBBB' |
| |
| WIFI_CONFIG_TEMPLATE = '''\ |
| Intf0MacAddress={0} |
| Intf1MacAddress={0} |
| Intf2MacAddress={0} |
| Intf3MacAddress={0} |
| END |
| ''' |
| |
| ETHERNET_DEVICE = 'eth0' |
| |
| |
| def GenerateNextMac(mac_address_str): |
| '''Given a MAC address string, generate the next MAC address in sequence. |
| |
| Note: this strips off the vendor prefix and increments as though the suffix |
| was an integer. If the device suffix rolls over, there is no error thrown or |
| any other checking done. |
| |
| Parameters: |
| mac_address_str: string. Colon-separated six-octet hexidecimal MAC address. |
| |
| Returns: |
| string. The next MAC address in the sequence. |
| ''' |
| device_suffix = GetMacDeviceSuffixString(mac_address_str) |
| suffix_number = MacDeviceSuffixToNumber(device_suffix) |
| suffix_string = MacDeviceSuffixNumberToString(suffix_number + 1) |
| next_mac = MAC_VENDOR_PREFIX_STR + ':' + suffix_string |
| return next_mac |
| |
| |
| def MacDeviceSuffixNumberToString(device_suffix_number): |
| '''Given a device suffix number, generate a colon-separated hexidecimal |
| representation. |
| |
| Parameters: |
| device_suffix_number: integer. The number to convert into a MAC suffix. |
| |
| Returns: |
| string. The colon-separated hexidecimal version of the number passed in. |
| ''' |
| suffix_string = '%06x' % device_suffix_number |
| suffix_array = [] |
| |
| for idx in range(0, len(suffix_string), 2): |
| suffix_array.append(suffix_string[idx] + suffix_string[idx + 1]) |
| |
| return ':'.join(suffix_array) |
| |
| |
| def MacDeviceSuffixToNumber(mac_suffix): |
| '''Converts a given a three-octet colon separated hexidecimal MAC device suffix |
| into an integer.''' |
| mac_array = mac_suffix.split(':') |
| flatmac = ''.join(mac_array) |
| return int(flatmac, 16) |
| |
| |
| def GetMacDeviceSuffixString(mac_address): |
| '''Strip the vendor prefix from a given a full six-octet colon separated |
| hexidecimal MAC.''' |
| mac_array = mac_address.split(':') |
| return ':'.join(mac_array[3:]) |
| |
| |
| def FindEthernetMacString(device): |
| '''Returns the MAC address string for a given network device from sysfs. |
| |
| If an error occurs attempting to read from sysfs, or runs into an EOF |
| prematurely, returns None. |
| ''' |
| sysfs_path = '/sys/class/net/%s/address' % (device) |
| |
| try: |
| with open(sysfs_path, 'r') as fp: |
| address = fp.readline() |
| if len(address) == 0: |
| return None |
| address = address[:-1] |
| return address |
| except Exception as e: |
| print('Error reading %s: %s' % (sysfs_path, e)) |
| return None |
| |
| |
| def WriteWifiMacAddress(next_mac): |
| '''Writes the given MAC address string to the wifi configuration files.''' |
| try: |
| with open(WIFI_ADDR_PATH, 'w') as fp: |
| fp.write(WIFI_CONFIG_TEMPLATE.format(next_mac)) |
| return True |
| except Exception as e: |
| print('Error writing wifi configuration to %s: %s' % (WIFI_ADDR_PATH, e)) |
| return False |
| |
| |
| def WriteBluetoothMacAddress(next_mac): |
| '''Writes the given MAC address string to a binary file readable by Bluez.''' |
| mac_bytes = [int(x, 16) for x in next_mac.split(':')] |
| |
| try: |
| with open(BD_ADDR_PATH, 'w') as fp: |
| fp.write(struct.pack(BD_ADDR_HEADER_STRUCT, BD_NVITEM, BD_RDWR_PROT, |
| BD_NVITEM_SIZE)) |
| fp.write(struct.pack(BD_ADDR_MAC_STRUCT, *mac_bytes)) |
| return True |
| except Exception as e: |
| print('Error writing bluetooth configuration to %s: %s' % (BD_ADDR_PATH, e)) |
| |
| |
| def Main(): |
| base_mac_address = FindEthernetMacString(ETHERNET_DEVICE) |
| |
| if base_mac_address == None: |
| sys.stderr.write('Unable to find MAC address for device %s\n' % (ETHERNET_DEVICE)) |
| sys.exit(1) |
| |
| next_mac = GenerateNextMac(base_mac_address) |
| print('Wifi/Bt MAC address will be %s' % next_mac) |
| |
| WriteWifiMacAddress(next_mac) |
| WriteBluetoothMacAddress(next_mac) |
| |
| |
| if __name__ == '__main__': |
| Main() |