OpenFlow switch configuration

The status and configuration of an OpenFlow datapath and its parts (ports, queues) is represented by instances of the classes below. All these classes are named tuple classes (cf. Python’s collections), i.e. configuration objects are also tuples whose elements each correspond to an attribute. To create a configuration object, its attributes can be given in positional order, or using keywords, i.e.:

from openfaucet import ofconfig
port_config = ofconfig.PortConfig(
    port_down=False, no_stp=True, no_recv=True, no_recv_stp=True,
    no_flood=False, no_fwd=False, no_packet_in=False)

is equivalent to:

from openfaucet import ofconfig
port_config = ofconfig.PortConfig(False, True, True, True, False,
                                  False, False)

Likewise, attributes can be accessed by position or by name, i.e.:

no_stp = port_config[1]

is equivalent to:

no_stp = port_config.no_stp

Attribute access by name is recommended for readability. Every configuration object, just like any tuple, is immutable and hashable. A copy of an existing configuration object with some of its attributes modified can be created by calling _replace(), for instance:

new_port_config = port_config._replace(port_down=True, no_packet_in=True)

Datapath configuration

class openfaucet.ofconfig.SwitchFeatures

Describes the features of a datapath.

datapath_id

The datapath’s unique ID, as a binary string.

n_buffers

The maximum number of buffers that can be used at once, each to buffer a packet.

n_tables

The number of tables supported by the datapath.

cap_*: Boolean flags indicating each the support of not of a capability:

cap_flow_stats

A boolean flag which if True indicates that flow statistics are supported by the datapath.

cap_table_stats

A boolean flag which if True indicates that table statistics are supported by the datapath.

cap_port_stats

A boolean flag which if True indicates that port statistics are supported by the datapath.

cap_stp

A boolean flag which if True indicates that the 802.1d Spanning Tree Protocol is supported by the datapath.

cap_ip_reasm

A boolean flag which if True indicates that the datapath can reassemble IP fragments.

cap_queue_stats

A boolean flag which if True indicates that queue statistics are supported by the datapath.

cap_arp_match_ip

A boolean flag which if True indicates that the datapath can match IP addresses in ARP packets.

actions

The frozenset of standard action type codes that is supported by the switch. See ofaction for the list of standard action types.

ports

A tuple of PhyPort objects defining the physical ports of the switch.

class openfaucet.ofconfig.SwitchConfig

The configuration of an OpenFlow switch.

config_frag

Indicates how IP fragments should be treated, either OFPC_FRAG_NORMAL (no special handling for fragments), OFPC_FRAG_DROP (drop fragments), or OFPC_FRAG_REASM (reassemble, only if supported, cf. cap_ip_reasm).

miss_send_len

The maximum number of bytes of new flow packets that the datapath should send to the controller in OFPT_PACKET_IN messages.

Port configuration

class openfaucet.ofconfig.PhyPort

The description of a physical port of an OpenFlow switch.

port_no

The port’s unique number, as a 16-bit unsigned integer. Must be between 1 and OFPP_MAX.

hw_addr

The port’s MAC address, as a binary string.

name

The port’s human-readable name, limited to 16 characters.

config

A PortConfig object indicating the configuration of the port.

state_link_down

A boolean value indicating that no physical link is present.

state_stp

Indicates the Spanning Tree Protocol state, either OFPPS_STP_LISTEN (not learning or relaying frames), OFPPS_STP_LEARN (learning but not relaying frames), OFPPS_STP_FORWARD (learning and relaying frames), or OFPPS_STP_BLOCK (not part of spanning tree).

curr

A PortFeatures object defining the current features of the port.

advertised

A PortFeatures object defining the features being advertised by the port.

supported

A PortFeatures object defining the features supported by the port.

peer

A PortFeatures object defining the features advertised by the peer connected to the port.

class openfaucet.ofconfig.PortConfig

The description of the configuration of a physical port.

port_down

A boolean flag which if True indicates that the port is administratively down.

no_stp

A boolean flag which if True indicates that 802.1D Spanning Tree Protocol is disabled on the port.

no_recv

A boolean flag which if True indicates that all received packets are dropped except 802.1D Spanning Tree Protocol packets.

no_recv_stp

A boolean flag which if True indicates that all received 802.1D STP packets are dropped.

no_flood

A boolean flag which if True indicates that this port is not included when flooding.

no_fwd

A boolean flag which if True indicates that packets forwarded to the port are dropped.

no_packet_in

A boolean flag which if True indicates that no packet-in messages are sent by the datapath for packets received on the port.

class openfaucet.ofconfig.PortFeatures

Boolean attributes describing the features of a physical port.

mode_10mb_hd

If True, 10 Mbps half-duplex rate is supported.

mode_10mb_fd

If True, 10 Mbps full-duplex rate is supported.

mode_100mb_hd

If True, 100 Mbps half-duplex rate is supported.

mode_100mb_fd

If True, 100 Mbps full-duplex rate is supported.

mode_1gb_hd

If True, 1 Gbps half-duplex rate is supported.

mode_1gb_fd

If True, 1 Gbps full-duplex rate is supported.

mode_10gb_fd

If True, 10 Gbps full-duplex rate is supported.

copper

If True, a copper medium is supported as the link type.

fiber

If True, a fiber medium is supported as the link type.

autoneg

If True, the auto-negotiation feature is supported.

pause

If True, the pause feature is supported.

pause_asym

If True, the asymmetric pause feature is supported.

Queue configuration

class openfaucet.ofconfig.PacketQueue

The description of a packet queue.

queue_id

The queue’s ID, as 32-bit unsigned integer.

min_rate

If specified for this queue, the minimum data rate guaranteed, as a 16-bit unsigned integer. This value is given in 1/10 of a percent. If >1000, the queuing is disabled. If None, this property is not available for this queue.