Family ovs_packet netlink specification

Contents

• Family ovs_packet netlink specification

  • Summary

  • Operations

    • miss

    • action

    • execute

  • Definitions

    • ovs-header

  • Attribute sets

    • packet

Summary

OVS packet execution over generic netlink.

Only OVS_PACKET_CMD_EXECUTE is exposed as a genl operation. OVS_PACKET_CMD_MISS and OVS_PACKET_CMD_ACTION are kernel-to-userspace upcalls sent via genlmsg_unicast() to the vport’s upcall_pid and have no associated genl_ops or multicast group.

Several attributes in the attribute set (userdata, egress-tun-key, len) exist for the upcall path and are not used by the EXECUTE operation. For EXECUTE, packet, key, and actions are mandatory (kernel returns -EINVAL without them).

Operations

miss

Notify userspace of a flow table miss for a received packet.

value

1

attribute-set

packet

event

attributes

[packet, key, userdata, actions, egress-tun-key, mru, len, hash]

action

Notify userspace as requested by an OVS_ACTION_ATTR_USERSPACE action.

value

2

attribute-set

packet

event

attributes

[packet, key, userdata, actions, egress-tun-key, mru, len, hash]

execute

Apply actions to a packet.

value

3

attribute-set

packet

do

request

attributes

[packet, key, actions, probe, mru, hash, upcall-pid]

Definitions

ovs-header

type

struct

members

dp-ifindex (u32)

Attribute sets

packet

packet (binary)

doc

Packet data, from the start of the Ethernet header.

key (binary)

doc

Nested OVS_KEY_ATTR_* attributes, extracted flow key. Defined as binary because the key attribute-set belongs to the ovs_flow family spec; cross-spec references are not supported.

actions (binary)

doc

Nested OVS_ACTION_ATTR_* attributes. Defined as binary for the same reason as key.

userdata (binary)

doc

Opaque userspace cookie from OVS_USERSPACE_ATTR_USERDATA.

egress-tun-key (binary)

doc

Nested OVS_TUNNEL_KEY_ATTR_* for output tunnel metadata.

unused1 (unused)

unused2 (unused)

probe (flag)

doc

Packet operation is a feature probe, error logging suppressed.

mru (u16)

doc

Maximum received IP fragment size.

len (u32)

doc

Packet size before truncation.

hash (u64)

doc

Packet hash, low 32 bits are skb hash, upper bits are flags.

upcall-pid (u32)

doc

Netlink PID to use for upcalls during EXECUTE processing.