path: root/ryu/ofproto/ofproto_v1_2.py

# Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
# Copyright (C) 2012 Isaku Yamahata <yamahata at valinux co jp>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from struct import calcsize


MAX_XID = 0xffffffff

# define constants
OFP_VERSION = 0x03
OFP_MAX_TABLE_NAME_LEN = 32
OFP_MAX_TABLE_NAME_LEN_STR = str(OFP_MAX_TABLE_NAME_LEN)
OFP_MAX_PORT_NAME_LEN = 16
OFP_TCP_PORT = 6633
OFP_SSL_PORT = 6633
OFP_ETH_ALEN = 6
OFP_ETH_ALEN_STR = str(OFP_ETH_ALEN)

# enum ofp_port_no
OFPP_MAX = 0xffffff00
OFPP_IN_PORT = 0xfffffff8       # Send the packet out the input port. This
                                # virtual port must be explicitly used
                                # in order to send back out of the input
                                # port.
OFPP_TABLE = 0xfffffff9         # Perform actions in flow table.
                                # NB: This can only be the destination
                                # port for packet-out messages.
OFPP_NORMAL = 0xfffffffa        # Process with normal L2/L3 switching.
OFPP_FLOOD = 0xfffffffb         # All physical ports except input port and
                                # those disabled by STP.
OFPP_ALL = 0xfffffffc           # All physical ports except input port.
OFPP_CONTROLLER = 0xfffffffd    # Send to controller.
OFPP_LOCAL = 0xfffffffe         # Local openflow "port".
OFPP_NONE = 0xffffffff 	        # Not associated with a physical port.

# enum ofp_type
OFPT_HELLO = 0    # Symmetric message
OFPT_ERROR = 1    # Symmetric message
OFPT_ECHO_REQUEST = 2    # Symmetric message
OFPT_ECHO_REPLY = 3    # Symmetric message
OFPT_EXPERIMENTER = 4    # Symmetric message
OFPT_FEATURES_REQUEST = 5    # Controller/switch message
OFPT_FEATURES_REPLY = 6    # Controller/switch message
OFPT_GET_CONFIG_REQUEST = 7    # Controller/switch message
OFPT_GET_CONFIG_REPLY = 8    # Controller/switch message
OFPT_SET_CONFIG = 9    # Controller/switch message
OFPT_PACKET_IN = 10    # Async message
OFPT_FLOW_REMOVED = 11    # Async message
OFPT_PORT_STATUS = 12    # Async message
OFPT_PACKET_OUT = 13    # Controller/switch message
OFPT_FLOW_MOD = 14    # Controller/switch message
OFPT_GROUP_MOD = 15    # Controller/switch message
OFPT_PORT_MOD = 16    # Controller/switch message
OFPT_TABLE_MOD = 17    # Controller/switch message
OFPT_STATS_REQUEST = 18    # Controller/switch message
OFPT_STATS_REPLY = 19    # Controller/switch message
OFPT_BARRIER_REQUEST = 20    # Controller/switch message
OFPT_BARRIER_REPLY = 21    # Controller/switch message
OFPT_QUEUE_GET_CONFIG_REQUEST = 22    # Controller/switch message
OFPT_QUEUE_GET_CONFIG_REPLY = 23    # Controller/switch message
OFPT_ROLE_REQUEST = 24    # Controller/switch message
OFPT_ROLE_REPLY = 25    # Controller/switch message

OFP_HEADER_PACK_STR = '!BBHI'
OFP_HEADER_SIZE = 8
OFP_MSG_SIZE_MAX = 65535
assert calcsize(OFP_HEADER_PACK_STR) == OFP_HEADER_SIZE

# define constants
OFP_DEFAULT_MISS_SEND_LEN = 128

# enum ofp_config_flags
OFPC_FRAG_NORMAL = 0    # No special handling for fragments.
OFPC_FRAG_DROP = 1      # Drop fragments.
OFPC_FRAG_REASM = 2     # Reassemble (only if OFPC_IP_REASM set).
OFPC_FRAG_MASK = 3
OFPC_INVALID_TTL_TO_CONTROLLER = 1 << 2  # Send packets with invalid
                                         # TTL to the controller.

# enum ofp_table
OFPTT_MAX = 0xfe
OFPTT_ALL = 0xff

# enum ofp_table_config
OFPTC_TABLE_MISS_CONTROLLER = 0
OFPTC_TABLE_MISS_CONTINUE = 1 << 0
OFPTC_TABLE_MISS_DROP = 1 << 1
OFPTC_TABLE_MISS_MASK = 3

OFP_SWITCH_CONFIG_PACK_STR = '!HH'
OFP_SWITCH_CONFIG_SIZE = 12
assert (calcsize(OFP_SWITCH_CONFIG_PACK_STR) + OFP_HEADER_SIZE ==
        OFP_SWITCH_CONFIG_SIZE)

# enum ofp_capabilities
OFPC_FLOW_STATS = 1 << 0    # Flow statistics.
OFPC_TABLE_STATS = 1 << 1    # Table statistics.
OFPC_PORT_STATS = 1 << 2    # Port statistics.
OFPC_GROUP_STATS = 1 << 3    # 802.1d spanning tree.
OFPC_IP_REASM = 1 << 5        # Can reassemble IP fragments.
OFPC_QUEUE_STATS = 1 << 6    # Queue statistics.
OFPC_PORT_BLOCKED = 1 << 8    # Match IP addresses in ARP pkts.

# enum ofp_port_config
OFPPC_PORT_DOWN = 1 << 0    # Port is administratively down.
OFPPC_NO_RECV = 1 << 2        # Drop all packets recieved by port.
OFPPC_NO_FWD = 1 << 5        # Drop packets forwarded to port.
OFPPC_NO_PACKET_IN = 1 << 6    # Do not send packet-in msgs for port.

# enum ofp_port_state
OFPPS_LINK_DOWN = 1 << 0    # No physical link present.
OFPPS_BLOCKED = 1 << 1        # Port is blocked.
OFPPS_LIVE = 1 << 2        # Live for Fast Failover Group.

# enum ofp_port_features
OFPPF_10MB_HD = 1 << 0    # 10 Mb half-duplex rate support.
OFPPF_10MB_FD = 1 << 1    # 10 Mb full-duplex rate support.
OFPPF_100MB_HD = 1 << 2    # 100 Mb half-duplex rate support.
OFPPF_100MB_FD = 1 << 3    # 100 Mb full-duplex rate support.
OFPPF_1GB_HD = 1 << 4    # 1 Gb half-duplex rate support.
OFPPF_1GB_FD = 1 << 5    # 1 Gb full-duplex rate support.
OFPPF_10GB_FD = 1 << 6    # 10 Gb full-duplex rate support.
OFPPF_40GB_FD = 1 << 7    # 40 Gb full-duplex rate support.
OFPPF_100GB_FD = 1 << 8    # 100 Gb full-duplex rate support.
OFPPF_1TB_FD = 1 << 9    # 1 Tb full-duplex rate support.
OFPPF_OTHER = 1 << 10    # Other rate, not in the list.
OFPPF_COPPER = 1 << 11    # Copper medium.
OFPPF_FIBER = 1 << 12    # Fiber medium.
OFPPF_AUTONEG = 1 << 13    # Auto-negotiation.
OFPPF_PAUSE = 1 << 14    # Pause.
OFPPF_PAUSE_ASYM = 1 << 15    # Asymmetric pause.

_OFP_PORT_PACK_STR = 'I4x' + OFP_ETH_ALEN_STR + 's' + '2x' + \
                     str(OFP_MAX_PORT_NAME_LEN) + 's' + 'IIIIIIII'
OFP_PORT_PACK_STR = '!' + _OFP_PORT_PACK_STR
OFP_PORT_SIZE = 64
assert calcsize(OFP_PORT_PACK_STR) == OFP_PORT_SIZE

OFP_SWITCH_FEATURES_PACK_STR = '!QIB3xII'
OFP_SWITCH_FEATURES_SIZE = 32
assert (calcsize(OFP_SWITCH_FEATURES_PACK_STR) + OFP_HEADER_SIZE ==
        OFP_SWITCH_FEATURES_SIZE)

# enum ofp_port_reason
OFPPR_ADD = 0    # The port was added.
OFPPR_DELETE = 1    # The port was removed.
OFPPR_MODIFY = 2    # Some attribute of the port has changed.

OFP_PORT_STATUS_PACK_STR = '!B7x' + _OFP_PORT_PACK_STR
OFP_PORT_STATUS_DESC_OFFSET = OFP_HEADER_SIZE + 8
OFP_PORT_STATUS_SIZE = 80
assert (calcsize(OFP_PORT_STATUS_PACK_STR) + OFP_HEADER_SIZE ==
        OFP_PORT_STATUS_SIZE)

OFP_PORT_MOD_PACK_STR = '!I4x' + OFP_ETH_ALEN_STR + 'B2xIII4x'
OFP_PORT_MOD_SIZE = 40
assert calcsize(OFP_PORT_MOD_PACK_STR) + OFP_HEADER_SIZE == OFP_PORT_MOD_SIZE

# enum ofp_packet_in_reason
OFPR_NO_MATCH = 0    # No matching flow.
OFPR_ACTION = 1        # Action explicitly output to controller.
OFPR_INVALID_TTL = 2    # Packet has invalid TTL.

_OFP_MATCH_PACK_STR = 'HHBBBB'
OFP_MATCH_PACK_STR = '!' + _OFP_MATCH_PACK_STR
OFP_MATCH_SIZE = 8
assert calcsize(OFP_MATCH_PACK_STR) == OFP_MATCH_SIZE

OFP_PACKET_IN_PACK_STR = '!IHBB'  # the last 2x is for ofp_packet_in::data
OFP_PACKET_IN_SIZE = 24
OFP_PACKET_IN_DATA_OFFSET = 18
assert calcsize(OFP_PACKET_IN_PACK_STR) + OFP_MATCH_SIZE + OFP_HEADER_SIZE ==\
       OFP_PACKET_IN_SIZE

# enum ofp_action_type
OFPAT_OUTPUT = 0    # Output to switch port.
OFPAT_COPY_TTL_OUT = 11  # Copy TTL "outwards" -- from
                         # next-to-outermost to outermost
OFPAT_COPY_TTL_IN = 12  # Copy TTL "inwards" -- from outermost to
                        # next-to-outermost
OFPAT_SET_MPLS_TTL = 15  # MPLS TTL.
OFPAT_DEC_MPLS_TTL = 16  # Decrement MPLS TTL
OFPAT_PUSH_VLAN = 17  # Push a new VLAN tag
OFPAT_POP_VLAN = 18  # Pop the outer VLAN tag
OFPAT_PUSH_MPLS = 19  # Push a new MPLS tag
OFPAT_POP_MPLS = 20  # Pop the outer MPLS tag
OFPAT_SET_QUEUE = 21  # Set queue id when outputting to a port
OFPAT_GROUP = 22  # Apply group
OFPAT_SET_NW_TTL = 23  # IP TTL.
OFPAT_DEC_NW_TTL = 24  # Decrement IP TTL.
OFPAT_SET_FIELD = 25  # Set a header field using OXM TLV format.
OFPAT_EXPERIMENTER = 0xffff

OFP_ACTION_OUTPUT_PACK_STR = '!HHIH6x'
OFP_ACTION_OUTPUT_SIZE = 16
assert calcsize(OFP_ACTION_OUTPUT_PACK_STR) == OFP_ACTION_OUTPUT_SIZE
OFP_ACTION_OUTPUT_LEN = 16

# enum ofp_controller_max_len
OFPCML_MAX = 0xffe5  # maximum max_len value which can be used to
                     # request a specific byte length.
OFPCML_NO_BUFFER = 0xffff  # indicates that no buffering should be
                           # applied and the whole packet is to be
                           # sent to the controller.

OFP_ACTION_EXPERIMENTER_HEADER_PACK_STR = '!HHI'
OFP_ACTION_EXPERIMENTER_HEADER_SIZE = 8
assert (calcsize(OFP_ACTION_EXPERIMENTER_HEADER_PACK_STR) ==
        OFP_ACTION_EXPERIMENTER_HEADER_SIZE)

OFP_ACTION_HEADER_PACK_STR = '!HH4x'
OFP_ACTION_HEADER_SIZE = 8
assert calcsize(OFP_ACTION_HEADER_PACK_STR) == OFP_ACTION_HEADER_SIZE

OFP_PACKET_OUT_PACK_STR = '!IIH6x'
OFP_PACKET_OUT_SIZE = 24
assert (calcsize(OFP_PACKET_OUT_PACK_STR) + OFP_HEADER_SIZE ==
        OFP_PACKET_OUT_SIZE)

# enum ofp_flow_mod_command
OFPFC_ADD = 0    # New flow.
OFPFC_MODIFY = 1    # Modify all matching flows.
OFPFC_MODIFY_STRICT = 2    # Modify entry strictly matching wildcards
OFPFC_DELETE = 3    # Delete all matching flows.
OFPFC_DELETE_STRICT = 4    # Strictly match wildcards and priority.

# enum ofp_group_mod_command
OFPGC_ADD = 0  # New group.
OFPGC_MODIFY = 1  # Modify all matching groups.
FPGC_DELETE = 2  # Delete all matching groups.

# enum ofp_match_type
OFPMT_STANDARD = 0  # Deprecated
OFPMT_OXM = 1  # OpenFlow Extensible Match

# enum ofp_mxm_class
OFPXMC_NXM_0 = 0x0000  # Backward compatibility with NXM
OFPXMC_NXM_1 = 0x0001  # Backward compatibility with NXM
OFPXMC_OPENFLOW_BASIC = 0x8000  # Basic class for OpenFlow
OFPXMC_EXPERIMENTER = 0xFFFF  # Experimenter class

# enmu oxm_ofb_match_fields
OFPXMT_OFB_IN_PORT = 0  # Switch input port.
OFPXMT_OFB_IN_PHY_PORT = 1  # Switch physical input port.
OFPXMT_OFB_METADATA = 2  # Metadata passed between tables.
OFPXMT_OFB_ETH_DST = 3  # Ethernet destination address.
OFPXMT_OFB_ETH_SRC = 4  # Ethernet source address.
OFPXMT_OFB_ETH_TYPE = 5  # Ethernet frame type.
OFPXMT_OFB_VLAN_VID = 6  # VLAN id.
OFPXMT_OFB_VLAN_PCP = 7  # VLAN priority.
OFPXMT_OFB_IP_DSCP = 8  # IP DSCP (6 bits in ToS field).
OFPXMT_OFB_IP_ECN = 9  # IP ECN (2 bits in ToS field).
OFPXMT_OFB_IP_PROTO = 10  # IP protocol.
OFPXMT_OFB_IPV4_SRC = 11  # IPv4 source address.
OFPXMT_OFB_IPV4_DST = 12  # IPv4 destination address.
OFPXMT_OFB_TCP_SRC = 13  # TCP source port.
OFPXMT_OFB_TCP_DST = 14  # TCP destination port.
OFPXMT_OFB_UDP_SRC = 15  # UDP source port.
OFPXMT_OFB_UDP_DST = 16  # UDP destination port.
OFPXMT_OFB_SCTP_SRC = 17  # SCTP source port.
OFPXMT_OFB_SCTP_DST = 18  # SCTP destination port.
OFPXMT_OFB_ICMPV4_TYPE = 19  # ICMP type.
OFPXMT_OFB_ICMPV4_CODE = 20  # ICMP code.
OFPXMT_OFB_ARP_OP = 21  # ARP opcode.
OFPXMT_OFB_ARP_SPA = 22  # ARP source IPv4 address.
OFPXMT_OFB_ARP_TPA = 23  # ARP target IPv4 address.
OFPXMT_OFB_ARP_SHA = 24  # ARP source hardware address.
OFPXMT_OFB_ARP_THA = 25  # ARP target hardware address.
OFPXMT_OFB_IPV6_SRC = 26  # IPv6 source address.
OFPXMT_OFB_IPV6_DST = 27  # IPv6 destination address.
OFPXMT_OFB_IPV6_FLABEL = 28  # IPv6 Flow Label
OFPXMT_OFB_ICMPV6_TYPE = 29  # ICMPv6 type.
OFPXMT_OFB_ICMPV6_CODE = 30  # ICMPv6 code.
OFPXMT_OFB_IPV6_ND_TARGET = 31  # Target address for ND.
OFPXMT_OFB_IPV6_ND_SLL = 32  # Source link-layer for ND.
OFPXMT_OFB_IPV6_ND_TLL = 33  # Target link-layer for ND.
OFPXMT_OFB_MPLS_LABEL = 34  # MPLS label.
OFPXMT_OFB_MPLS_TC = 35  # MPLS TC.

# enum ofp_vlan_id
OFPVID_PRESENT = 0x1000  # bit that indicate that a VLAN id is set.
OFPVID_NONE = 0x0000  # No VLAN id was set.

# enum ofp_instruction_type
OFPID_GOTO_TABLE = 1  # Setup the next table in the lookup pipeline.
OFPIT_WRITE_METADATA = 2  # Setup the metadata field for use later in
                          # pipeline.
OFPIT_WRITE_ACTIONS = 3  # Write the action(s) onto the datapath
                         # action set
OFPIT_APPLY_ACTIONS = 4  # Applies the action(s) immediately
OFPIT_CLEAR_ACTIONS = 5  # Clears all actions from the datapath action
                         # set
OFPIT_EXPERIMENTER = 0xFFFF   # Experimenter instruction


OFP_FLOW_PERMANENT = 0
OFP_DEFAULT_PRIORITY = 0x8000

# enum ofp_flow_mod_flags
OFPFF_SEND_FLOW_REM = 1 << 0    # Send flow removed message when flow
                                # expires or is deleted.
OFPFF_CHECK_OVERLAP = 1 << 1    # Check for overlapping entries first.
OFPFF_RESET_COUNT = 1 << 2    # Reset flow packet and byte counts.

_OFP_FLOW_MOD_PACK_STR0 = 'QQBBHHHIIIH2x'
OFP_FLOW_MOD_PACK_STR = '!' + _OFP_FLOW_MOD_PACK_STR0 + _OFP_MATCH_PACK_STR
OFP_FLOW_MOD_PACK_STR0 = '!' + _OFP_FLOW_MOD_PACK_STR0
OFP_FLOW_MOD_SIZE = 56
assert (calcsize(OFP_FLOW_MOD_PACK_STR) + OFP_HEADER_SIZE == OFP_FLOW_MOD_SIZE)

# enum ofp_flow_removed_reason
OFPRR_IDLE_TIMEOUT = 0    # Flow idle time exceeded idle_timeout.
OFPRR_HARD_TIMEOUT = 1    # Time exceeded hard_timeout.
OFPRR_DELETE = 2    # Evicted by a DELETE flow mod.
OFPRR_GROUP_DELETE = 3  # Group was removed.

_OFP_FLOW_REMOVED_PACK_STR0 = 'QHBBIIHHQQ'
OFP_FLOW_REMOVED_PACK_STR = '!' + _OFP_FLOW_REMOVED_PACK_STR0 + \
                            _OFP_MATCH_PACK_STR
OFP_FLOW_REMOVED_PACK_STR0 = '!' + _OFP_FLOW_REMOVED_PACK_STR0
OFP_FLOW_REMOVED_SIZE = 56
assert (calcsize(OFP_FLOW_REMOVED_PACK_STR) + OFP_HEADER_SIZE ==
        OFP_FLOW_REMOVED_SIZE)

# enum ofp_group_mod_command
OFPGC_ADD = 0  # New group.
OFPGC_MODIFY = 1  # Modify all matching groups.
OFPGC_DELETE = 2  # Deletes all matching groups.

# enum ofp_group_type
OFPGT_ALL = 0  # All (multicast/broadcast) group.
OFPGT_SELECT = 1  # Select group.
OFPGT_INDIRECT = 2  # Indirect group.
OFPGT_FF = 3  # Fast failover group.

# enum ofp_error_type
OFPET_HELLO_FAILED = 0        # Hello protocol failed.
OFPET_BAD_REQUEST = 1        # Request was not understood.
OFPET_BAD_ACTION = 2        # Error in action description.
OFPET_BAD_INSTRUCTION = 3    # Error in instruction list.
OFPET_BAD_MATCH = 4        # Error in match.
OFPET_FLOW_MOD_FAILED = 5    # Problem modifying flow entry.
OFPET_GROUP_MOD_FAILED = 6    # Problem modifying group entry.
OFPET_PORT_MOD_FAILED = 7    # OFPT_PORT_MOD failed.
OFPET_TABLE_MOD_FAILED = 8    # Table mod request failed.
OFPET_QUEUE_OP_FAILED = 9    # Queue operation failed.
OFPET_SWITCH_CONFIG_FAILED = 10    # Switch config request failed.
OFPET_ROLE_REQUEST_FAILED = 11    # Controller Role request failed.
OFPET_EXPERIMENTER = 0xffff    # Experimenter error messages.

# enum ofp_hello_failed_code
OFPHFC_INCOMPATIBLE = 0        # No compatible version.
OFPHFC_EPERM = 1        # Permissions error.

# enum ofp_bad_request_code
OFPBRC_BAD_VERSION = 0        # ofp_header.version not supported.
OFPBRC_BAD_TYPE = 1        # ofp_header.type not supported.
OFPBRC_BAD_STAT = 2        # ofp_stats_msg.type not supported.
OFPBRC_BAD_EXPERIMENTER = 3    # Experimenter id not supported
                # (in ofp_experimenter_header
                            # or ofp_stats_request or ofp_stats_reply).
OFPBRC_BAD_EXP_TYPE = 4        # Experimenter type not supported.
OFPBRC_EPERM = 5        # Permissions error.
OFPBRC_BAD_LEN = 6        # Wrong request length for type.
OFPBRC_BUFFER_EMPTY = 7        # Specified buffer has already been used.
OFPBRC_BUFFER_UNKNOWN = 8    # Specified buffer does not exist.
OFPBRC_BAD_TABLE_ID = 9        # Specified table-id invalid or does not exist.
OFPBRC_IS_SLAVE = 10        # Denied because controller is slave.
OFPBRC_BAD_PORT = 11        # Invalid port.
OFBRC_BAD_PACKET = 12        # Invalid packet in packet-out

# enum ofp_bad_action_code
OFPBAC_BAD_TYPE = 0        # Unknown action type.
OFPBAC_BAD_LEN = 1        # Length problem in actions.
OFPBAC_BAD_EXPERIMENTER = 2    # Unknown experimenter id specified.
OFPBAC_BAD_EXP_TYPE = 3        # Unknown action type for experimenter id.
OFPBAC_BAD_OUT_PORT = 4        # Problem validating output action.
OFPBAC_BAD_ARGUMENT = 5        # Bad action argument.
OFPBAC_EPERM = 6        # Permissions error.
OFPBAC_TOO_MANY = 7        # Can't handle this many actions.
OFPBAC_BAD_QUEUE = 8        # Problem validating output queue.
OFPBAC_BAD_OUT_GROUP = 9    # Invalid group id in forward action.
OFPBAC_MATCH_INCONSISTENT = 10    # Action can't apply for this match,
                # or Set-Field missing prerequisite.
OFPBAC_UNSUPPORTED_ORDER = 11    # Action order is unsupported for
                # the action list in an Apply-Actions
                # instruction
OFPBAC_BAD_TAG = 12        # Actions uses an unsupported tag/encap.
OFBAC_BAD_SET_TYPE = 13        # Unsupported type in SET_FIELD action.
OFPBAC_BAD_SET_LEN = 14        # Length problem in SET_FIELD action.
OFPBAC_BAD_SET_ARGUMENT = 15    # Bad arguement in SET_FIELD action.

# enum ofp_bad_instruction_code
OFPBIC_UNKNOWN_INST = 0        # Unknown instruction.
OFPBIC_UNSUP_INST = 1        # Switch or table does not support
                # the instruction.
OFPBIC_BAD_TABLE_ID = 2        # Invalid Table-Id specified
OFPBIC_UNSUP_METADATA = 3    # Metadata value unsupported by datapath.
OFPBIC_UNSUP_METADATA_MASK = 4    # Metadata mask value unsupported by
                # datapath.
OFPBIC_BAD_EXPERIMENTER = 5    # Unknown experimenter id specified.
OFPBIC_BAD_EXP_TYPE = 6        # Unknown instruction for experimenter id.
OFPBIC_BAD_EXP_LEN = 7        # Length problem in instrucitons.
OFPBIC_EPERM = 8        # Permissions error.

# enum ofp_bad_match_code
OFPBMC_BAD_TYPE = 0        # Unsupported match type apecified by
                                # the match.
OFPBMC_BAD_LEN = 1        # Length problem in math.
OFPBMC_BAD_TAG = 2        # Match uses an unsupported tag/encap.
OFPBMC_BAD_DL_ADDR_MASK = 3    # Unsupported datalink addr mask -
                                # switch does not support arbitrary
                                # datalink address mask.
OFPBMC_BAD_NW_ADDR_MASK = 4    # Unsupported network addr mask -
                                # switch does not support arbitrary
                                # network addres mask.
OFPBMC_BAD_WILDCARDS = 5    # Unsupported combination of fields
                                # masked or omitted in the match.
OFPBMC_BAD_FIELD = 6        # Unsupported field type in the match.
OFPBMC_BAD_VALUE = 7        # Unsupported value in a match field.
OFPBMC_BAD_MASK = 8        # Unsupported mask specified in the
                                # match.
OFPBMC_BAD_PREREQ = 9        # A prerequisite was not met.
OFPBMC_DUP_FIELD = 10        # A field type was duplicated.
OFPBMC_EPERM = 11         # Permissions error.

# enum ofp_flow_mod_failed_code
OFPFMFC_UNKNOWN = 0        # Unspecified error.
OFPFMFC_TABLES_FULL = 1        # Flow not added because table was full.
OFPFMFC_BAD_TABLE_ID = 2    # Table does not exist
OFPFMFC_OVERLAP = 3        # Attempted to add overlapping flow
                                # with CHECK_OVERLAP flag set.
OFPFMFC_EPERM = 4        # Permissions error.
OFPFMFC_BAD_TIMEOUT = 5        # Flow not added because of
                                # unsupported idle/hard timeout.
OFPFMFC_BAD_COMMAND = 6        # Unsupported or unknown command.
OFPFMFC_BAD_FLAGS = 7        # Unsupported or unknown flags.

# enum ofp_group_mod_failed_code
OFPGMFC_GROUP_EXISTS = 0
OFPGMFC_INVALID_GROUP = 1
OFPGMFC_WEIGHT_UNSUPPORTED = 2    # Switch does not support unequal load
                                  # sharing with select groups.
OFPGMFC_OUT_OF_GROUPS = 3         # The group table is full.
OFPGMFC_OUT_OF_BUCKETS = 4        # The maximum number of action buckets
                                  # for a group has been exceeded.
OFPGMFC_CHAINING_UNSUPPORTED = 5  # Switch does not support groups that
                                  # forward to groups.
OFPGMFC_WATCH_UNSUPPORTED = 6     # This group cannot watch the
                                  # watch_port or watch_group specified.
OFPGMFC_LOOP = 7                  # Group entry would cause a loop.
OFPGMFC_UNKNOWN_GROUP = 8         # Group not modified because a group
                                  # MODIFY attempted to modify a
                                  # non-existent group.
OFPGMFC_CHAINED_GROUP = 9         # Group not deleted because another
                                  # group is forwarding to it.
OFPGMFC_BAD_TYPE = 10             # Unsupported or unknown group type.
OFPGMFC_BAD_COMMAND = 11          # Unsupported or unknown command.
OFPGMFC_BAD_BUCKET = 12           # Error in bucket.
OFPGMFC_BAD_WATCH = 13            # Error in watch port/group.
OFPGMFC_EPERM = 14                # Permissions error.

# enum ofp_port_mod_failed_code
OFPPMFC_BAD_PORT = 0        # Specified port does not exist.
OFPPMFC_BAD_HW_ADDR = 1        # Specified hardware address does not
                                # match the port number.
OFPPMFC_BAD_CONFIG = 2        # Specified config is invalid.
OFPPMFC_BAD_ADVERTISE = 3    # Specified advertise is invalid.
OFPPMFC_EPERM = 4        # Permissions error.

# enum ofp_table_mod_failed_code
OFPTMFC_BAD_TABLE = 0        # Specified table does not exist.
OFPTMFC_BAD_CONFIG = 1        # Specified config is invalid.
OFPTMFC_EPERM = 2        # Permissions error

# enum ofp_queue_op_failed_code
OFPQOFC_BAD_PORT = 0        # Invalid port (or port does not exist).
OFPQOFC_BAD_QUEUE = 1        # Queue does not exist.
OFPQOFC_EPERM = 2        # Permissions error.

# enum ofp_switch_config_failed_code
OFPSCFC_BAD_FLAGS = 0        # Specified flags is invalid.
OFPSCFC_BAD_LEN = 1        # Specified len is invalid.
OFPQCFC_EPERM = 2        # Permissions error.

# enum ofp_role_request_failed_code
OFPRRFC_STALE = 0        # Stale Message: old generation_id.
OFPRRFC_UNSUP = 1        # Controller role change unsupported.
OFPRRFC_BAD_ROLE = 2        # Invalid role.

# enum ofp_queue_properties
OFPQT_MIN_RATE = 1        # Minimum datarate guaranteed.
OFPQT_MAX_RATE = 2        # Maximum datarate.
OFPQT_EXPERIMENTER = 0xffff     # Experimenter defined property.

OFP_ERROR_MSG_PACK_STR = '!HH'
OFP_ERROR_MSG_SIZE = 12
assert calcsize(OFP_ERROR_MSG_PACK_STR) + OFP_HEADER_SIZE == OFP_ERROR_MSG_SIZE

# enum ofp_stats_types
OFPST_DESC = 0
OFPST_FLOW = 1
OFPST_AGGREGATE = 2
OFPST_TABLE = 3
OFPST_PORT = 4
OFPST_QUEUE = 5
OFPST_GROUP = 6
OFPST_GROUP_DESC = 7
OFPST_GROUP_FEATURES = 8
OFPST_EXPERIMENTER = 0xffff

# enmu ofp_group_capabilities
OFPGFC_SELECT_WEIGHT = 1 << 0  # Support weight for select groups.
OFPGFC_SELECT_LIVENESS = 1 << 1  # Support liveness for select groups.
OFPGFC_CHAINING = 1 << 2  # Support chaining groups.
OFPGFC_CHAINING_CHECKS = 1 << 3  # Check chaining for loops and delete

_OFP_STATS_MSG_PACK_STR = 'HH4x'
OFP_STATS_MSG_PACK_STR = '!' + _OFP_STATS_MSG_PACK_STR
OFP_STATS_MSG_SIZE = 16
assert calcsize(OFP_STATS_MSG_PACK_STR) + OFP_HEADER_SIZE == OFP_STATS_MSG_SIZE

# enum ofp_controller_role
OFPCR_ROLE_NOCHANGE = 0  # Don't change current role.
OFPCR_ROLE_EQUAL = 1  # Default role, full access.
OFPCR_ROLE_MASTER = 2  # Full access, at most one master.
OFPCR_ROLE_SLAVE = 3  # Read-only access.

# define constants
DESC_STR_LEN = 256
DESC_STR_LEN_STR = str(DESC_STR_LEN)
SERIAL_NUM_LEN = 32
SERIAL_NUM_LEN_STR = str(SERIAL_NUM_LEN)

OFP_DESC_STATS_PACK_STR = '!' + \
                          DESC_STR_LEN_STR + 'c' + \
                          DESC_STR_LEN_STR + 'c' + \
                          DESC_STR_LEN_STR + 'c' + \
                          SERIAL_NUM_LEN_STR + 'c' + \
                          DESC_STR_LEN_STR + 'c'
OFP_DESC_STATS_SIZE = 1056
assert calcsize(OFP_DESC_STATS_PACK_STR) == OFP_DESC_STATS_SIZE

OFP_FLOW_STATS_REQUEST_PACK_STR = '!B3xII4xQQ' + _OFP_MATCH_PACK_STR
OFP_FLOW_STATS_REQUEST_SIZE = 40
assert calcsize(OFP_FLOW_STATS_REQUEST_PACK_STR) == OFP_FLOW_STATS_REQUEST_SIZE

OFP_FLOW_STATS_PACK_STR = '!HBxIIHHH6xQQQ' + _OFP_MATCH_PACK_STR
OFP_FLOW_STATS_SIZE = 56
assert calcsize(OFP_FLOW_STATS_PACK_STR) == OFP_FLOW_STATS_SIZE

OFP_AGGREGATE_STATS_REPLY_PACK_STR = '!QQI4x'
OFP_AGGREGATE_STATS_REPLY_SIZE = 24
assert calcsize(OFP_AGGREGATE_STATS_REPLY_PACK_STR) == \
       OFP_AGGREGATE_STATS_REPLY_SIZE

OFP_TABLE_STATS_PACK_STR = '!B7x' + OFP_MAX_TABLE_NAME_LEN_STR + \
                           'cQQIIQQQQIIIIQQ'
OFP_TABLE_STATS_SIZE = 128
assert calcsize(OFP_TABLE_STATS_PACK_STR) == OFP_TABLE_STATS_SIZE

OFP_PORT_STATS_REQUEST_PACK_STR = '!I4x'
OFP_PORT_STATS_REQUEST_SIZE = 8
assert calcsize(OFP_PORT_STATS_REQUEST_PACK_STR) == OFP_PORT_STATS_REQUEST_SIZE

OFP_PORT_STATS_PACK_STR = '!H6xQQQQQQQQQQQQ'
OFP_PORT_STATS_SIZE = 104
assert calcsize(OFP_PORT_STATS_PACK_STR) == OFP_PORT_STATS_SIZE

OFPQ_ALL = 0xffffffff

OFP_QUEUE_STATS_PACK_STR = '!IIQQQ'
OFP_QUEUE_STATS_SIZE = 32
assert calcsize(OFP_QUEUE_STATS_PACK_STR) == OFP_QUEUE_STATS_SIZE

OFP_EXPERIMENTER_STATS_PACK_STR = '!II'
OFP_EXPERIMENTER_STATS_SIZE = 8
assert calcsize(OFP_EXPERIMENTER_STATS_PACK_STR) == OFP_EXPERIMENTER_STATS_SIZE