예제 #1
0
 def get_if_mac(self, ifname):
     """
     Return the mac-address bound to the socket.
     """
     sock = socket.socket(socket.AF_INET,
                          socket.SOCK_DGRAM,
                          socket.IPPROTO_UDP)
     param = struct.pack('256s', (ifname[:15]+('\0'*241)).encode('latin-1'))
     info = fcntl.ioctl(sock.fileno(), 0x8927, param)
     return ''.join(['%02X' % textutil.str_to_ord(char) for char in info[18:24]])
예제 #2
0
def parse_dhcp_resp(response):
    """
    Parse DHCP response:
    Returns endpoint server or None on error.
    """
    logger.verbose("parse Dhcp Response")
    bytes_recv = len(response)
    endpoint = None
    gateway = None
    routes = None

    # Walk all the returned options, parsing out what we need, ignoring the
    # others. We need the custom option 245 to find the the endpoint we talk to
    # as well as to handle some Linux DHCP client incompatibilities;
    # options 3 for default gateway and 249 for routes; 255 is end.

    i = 0xF0  # offset to first option
    while i < bytes_recv:
        option = str_to_ord(response[i])
        length = 0
        if (i + 1) < bytes_recv:
            length = str_to_ord(response[i + 1])
        logger.verbose("DHCP option {0} at offset:{1} with length:{2}",
                       hex(option), hex(i), hex(length))
        if option == 255:
            logger.verbose("DHCP packet ended at offset:{0}", hex(i))
            break
        elif option == 249:
            routes = parse_route(response, option, i, length, bytes_recv)
        elif option == 3:
            gateway = parse_ip_addr(response, option, i, length, bytes_recv)
            logger.verbose("Default gateway:{0}, at {1}", gateway, hex(i))
        elif option == 245:
            endpoint = parse_ip_addr(response, option, i, length, bytes_recv)
            logger.verbose("Azure wire protocol endpoint:{0}, at {1}",
                           endpoint,
                           hex(i))
        else:
            logger.verbose("Skipping DHCP option:{0} at {1} with length {2}",
                           hex(option), hex(i), hex(length))
        i += length + 2
    return endpoint, gateway, routes
예제 #3
0
 def get_if_mac(self, ifname):
     """
     Return the mac-address bound to the socket.
     """
     sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM,
                          socket.IPPROTO_UDP)
     param = struct.pack('256s',
                         (ifname[:15] + ('\0' * 241)).encode('latin-1'))
     info = fcntl.ioctl(sock.fileno(), 0x8927, param)
     return ''.join(
         ['%02X' % textutil.str_to_ord(char) for char in info[18:24]])
예제 #4
0
def parse_route(response, option, i, length, bytes_recv):  # pylint: disable=W0613
    # http://msdn.microsoft.com/en-us/library/cc227282%28PROT.10%29.aspx
    logger.verbose("Routes at offset: {0} with length:{1}", hex(i),
                   hex(length))
    routes = []
    if length < 5:
        logger.error("Data too small for option:{0}", option)
    j = i + 2
    while j < (i + length + 2):
        mask_len_bits = str_to_ord(response[j])
        mask_len_bytes = (((mask_len_bits + 7) & ~7) >> 3)
        mask = 0xFFFFFFFF & (0xFFFFFFFF << (32 - mask_len_bits))
        j += 1
        net = unpack_big_endian(response, j, mask_len_bytes)
        net <<= (32 - mask_len_bytes * 8)
        net &= mask
        j += mask_len_bytes
        gateway = unpack_big_endian(response, j, 4)
        j += 4
        routes.append((net, mask, gateway))
    if j != (i + length + 2):
        logger.error("Unable to parse routes")
    return routes
예제 #5
0
파일: dhcp.py 프로젝트: Azure/WALinuxAgent
def parse_route(response, option, i, length, bytes_recv):
    # http://msdn.microsoft.com/en-us/library/cc227282%28PROT.10%29.aspx
    logger.verbose("Routes at offset: {0} with length:{1}", hex(i),
                   hex(length))
    routes = []
    if length < 5:
        logger.error("Data too small for option:{0}", option)
    j = i + 2
    while j < (i + length + 2):
        mask_len_bits = str_to_ord(response[j])
        mask_len_bytes = (((mask_len_bits + 7) & ~7) >> 3)
        mask = 0xFFFFFFFF & (0xFFFFFFFF << (32 - mask_len_bits))
        j += 1
        net = unpack_big_endian(response, j, mask_len_bytes)
        net <<= (32 - mask_len_bytes * 8)
        net &= mask
        j += mask_len_bytes
        gateway = unpack_big_endian(response, j, 4)
        j += 4
        routes.append((net, mask, gateway))
    if j != (i + length + 2):
        logger.error("Unable to parse routes")
    return routes
예제 #6
0
def build_dhcp_request(mac_addr, request_broadcast):
    """
    Build DHCP request string.
    """
    #
    # typedef struct _DHCP {
    #  UINT8   Opcode;                    /* op:    BOOTREQUEST or BOOTREPLY */
    #  UINT8   HardwareAddressType;       /* htype: ethernet */
    #  UINT8   HardwareAddressLength;     /* hlen:  6 (48 bit mac address) */
    #  UINT8   Hops;                      /* hops:  0 */
    #  UINT8   TransactionID[4];          /* xid:   random */
    #  UINT8   Seconds[2];                /* secs:  0 */
    #  UINT8   Flags[2];                  /* flags: 0 or 0x8000 for broadcast*/
    #  UINT8   ClientIpAddress[4];        /* ciaddr: 0 */
    #  UINT8   YourIpAddress[4];          /* yiaddr: 0 */
    #  UINT8   ServerIpAddress[4];        /* siaddr: 0 */
    #  UINT8   RelayAgentIpAddress[4];    /* giaddr: 0 */
    #  UINT8   ClientHardwareAddress[16]; /* chaddr: 6 byte eth MAC address */
    #  UINT8   ServerName[64];            /* sname:  0 */
    #  UINT8   BootFileName[128];         /* file:   0  */
    #  UINT8   MagicCookie[4];            /*   99  130   83   99 */
    #                                        /* 0x63 0x82 0x53 0x63 */
    #     /* options -- hard code ours */
    #
    #     UINT8 MessageTypeCode;              /* 53 */
    #     UINT8 MessageTypeLength;            /* 1 */
    #     UINT8 MessageType;                  /* 1 for DISCOVER */
    #     UINT8 End;                          /* 255 */
    # } DHCP;
    #

    # tuple of 244 zeros
    # (struct.pack_into would be good here, but requires Python 2.5)
    request = [0] * 244

    trans_id = gen_trans_id()

    # Opcode = 1
    # HardwareAddressType = 1 (ethernet/MAC)
    # HardwareAddressLength = 6 (ethernet/MAC/48 bits)
    for a in range(0, 3):
        request[a] = [1, 1, 6][a]

    # fill in transaction id (random number to ensure response matches request)
    for a in range(0, 4):
        request[4 + a] = str_to_ord(trans_id[a])

    logger.verbose("BuildDhcpRequest: transactionId:%s,%04X" %
                   (hex_dump2(trans_id), unpack_big_endian(request, 4, 4)))

    if request_broadcast:
        # set broadcast flag to true to request the dhcp server
        # to respond to a boradcast address,
        # this is useful when user dhclient fails.
        request[0x0A] = 0x80

    # fill in ClientHardwareAddress
    for a in range(0, 6):
        request[0x1C + a] = str_to_ord(mac_addr[a])

    # DHCP Magic Cookie: 99, 130, 83, 99
    # MessageTypeCode = 53 DHCP Message Type
    # MessageTypeLength = 1
    # MessageType = DHCPDISCOVER
    # End = 255 DHCP_END
    for a in range(0, 8):
        request[0xEC + a] = [99, 130, 83, 99, 53, 1, 1, 255][a]
    return array.array("B", request)
예제 #7
0
파일: dhcp.py 프로젝트: Azure/WALinuxAgent
def build_dhcp_request(mac_addr, request_broadcast):
    """
    Build DHCP request string.
    """
    #
    # typedef struct _DHCP {
    #  UINT8   Opcode;                    /* op:    BOOTREQUEST or BOOTREPLY */
    #  UINT8   HardwareAddressType;       /* htype: ethernet */
    #  UINT8   HardwareAddressLength;     /* hlen:  6 (48 bit mac address) */
    #  UINT8   Hops;                      /* hops:  0 */
    #  UINT8   TransactionID[4];          /* xid:   random */
    #  UINT8   Seconds[2];                /* secs:  0 */
    #  UINT8   Flags[2];                  /* flags: 0 or 0x8000 for broadcast*/
    #  UINT8   ClientIpAddress[4];        /* ciaddr: 0 */
    #  UINT8   YourIpAddress[4];          /* yiaddr: 0 */
    #  UINT8   ServerIpAddress[4];        /* siaddr: 0 */
    #  UINT8   RelayAgentIpAddress[4];    /* giaddr: 0 */
    #  UINT8   ClientHardwareAddress[16]; /* chaddr: 6 byte eth MAC address */
    #  UINT8   ServerName[64];            /* sname:  0 */
    #  UINT8   BootFileName[128];         /* file:   0  */
    #  UINT8   MagicCookie[4];            /*   99  130   83   99 */
    #                                        /* 0x63 0x82 0x53 0x63 */
    #     /* options -- hard code ours */
    #
    #     UINT8 MessageTypeCode;              /* 53 */
    #     UINT8 MessageTypeLength;            /* 1 */
    #     UINT8 MessageType;                  /* 1 for DISCOVER */
    #     UINT8 End;                          /* 255 */
    # } DHCP;
    #

    # tuple of 244 zeros
    # (struct.pack_into would be good here, but requires Python 2.5)
    request = [0] * 244

    trans_id = gen_trans_id()

    # Opcode = 1
    # HardwareAddressType = 1 (ethernet/MAC)
    # HardwareAddressLength = 6 (ethernet/MAC/48 bits)
    for a in range(0, 3):
        request[a] = [1, 1, 6][a]

    # fill in transaction id (random number to ensure response matches request)
    for a in range(0, 4):
        request[4 + a] = str_to_ord(trans_id[a])

    logger.verbose("BuildDhcpRequest: transactionId:%s,%04X" % (
        hex_dump2(trans_id),
        unpack_big_endian(request, 4, 4)))

    if request_broadcast:
        # set broadcast flag to true to request the dhcp server
        # to respond to a boradcast address,
        # this is useful when user dhclient fails.
        request[0x0A] = 0x80;

    # fill in ClientHardwareAddress
    for a in range(0, 6):
        request[0x1C + a] = str_to_ord(mac_addr[a])

    # DHCP Magic Cookie: 99, 130, 83, 99
    # MessageTypeCode = 53 DHCP Message Type
    # MessageTypeLength = 1
    # MessageType = DHCPDISCOVER
    # End = 255 DHCP_END
    for a in range(0, 8):
        request[0xEC + a] = [99, 130, 83, 99, 53, 1, 1, 255][a]
    return array.array("B", request)