Family net-shaper netlink specification

Summary

Networking HW rate limiting configuration.

This API allows configuring HW shapers available on the network devices at different levels (queues, network device) and allows arbitrary manipulation of the scheduling tree of the involved shapers.

Each @shaper is identified within the given device, by a @handle, comprising both a @scope and an @id.

Depending on the @scope value, the shapers are attached to specific HW objects (queues, devices) or, for @node scope, represent a scheduling group, that can be placed in an arbitrary location of the scheduling tree.

Shapers can be created with two different operations: the @set operation, to create and update a single “attached” shaper, and the @group operation, to create and update a scheduling group. Only the @group operation can create @node scope shapers.

Existing shapers can be deleted/reset via the @delete operation.

The user can query the running configuration via the @get operation.

Different devices can provide different feature sets, e.g. with no support for complex scheduling hierarchy, or for some shaping parameters. The user can introspect the HW capabilities via the @cap-get operation.

Operations

get

Get information about a shaper for a given device.

attribute-set:

net-shaper

do:

pre

net-shaper-nl-pre-doit

post

net-shaper-nl-post-doit

request

attributes:

[ifindex, handle]

reply

attributes:

[ifindex, parent, handle, metric, bw-min, bw-max, burst, priority, weight]

dump:

pre

net-shaper-nl-pre-dumpit

post

net-shaper-nl-post-dumpit

request

attributes:

[ifindex]

reply

attributes:

[ifindex, parent, handle, metric, bw-min, bw-max, burst, priority, weight]

set

Create or update the specified shaper. The set operation can’t be used to create a @node scope shaper, use the @group operation instead.

attribute-set:

net-shaper

flags:

[admin-perm]

do:

pre

net-shaper-nl-pre-doit

post

net-shaper-nl-post-doit

request

attributes:

[ifindex, handle, metric, bw-min, bw-max, burst, priority, weight]

delete

Clear (remove) the specified shaper. When deleting a @node shaper, reattach all the node’s leaves to the deleted node’s parent. If, after the removal, the parent shaper has no more leaves and the parent shaper scope is @node, the parent node is deleted, recursively. When deleting a @queue shaper or a @netdev shaper, the shaper disappears from the hierarchy, but the queue/device can still send traffic: it has an implicit node with infinite bandwidth. The queue’s implicit node feeds an implicit RR node at the root of the hierarchy.

attribute-set:

net-shaper

flags:

[admin-perm]

do:

pre

net-shaper-nl-pre-doit

post

net-shaper-nl-post-doit

request

attributes:

[ifindex, handle]

group

Create or update a scheduling group, attaching the specified @leaves shapers under the specified node identified by @handle. The @leaves shapers scope must be @queue and the node shaper scope must be either @node or @netdev. When the node shaper has @node scope, if the @handle @id is not specified, a new shaper of such scope is created, otherwise the specified node must already exist. When updating an existing node shaper, the specified @leaves are added to the existing node; such node will also retain any preexisting leave. The @parent handle for a new node shaper defaults to the parent of all the leaves, provided all the leaves share the same parent. Otherwise @parent handle must be specified. The user can optionally provide shaping attributes for the node shaper. The operation is atomic, on failure no change is applied to the device shaping configuration, otherwise the @node shaper full identifier, comprising @binding and @handle, is provided as the reply.

attribute-set:

net-shaper

flags:

[admin-perm]

do:

pre

net-shaper-nl-pre-doit

post

net-shaper-nl-post-doit

request

attributes:

[ifindex, parent, handle, metric, bw-min, bw-max, burst, priority, weight, leaves]

reply

attributes:

[ifindex, handle]

cap-get

Get the shaper capabilities supported by the given device for the specified scope.

attribute-set:

caps

do:

pre

net-shaper-nl-cap-pre-doit

post

net-shaper-nl-cap-post-doit

request

attributes:

[ifindex, scope]

reply

attributes:

[ifindex, scope, support-metric-bps, support-metric-pps, support-nesting, support-bw-min, support-bw-max, support-burst, support-priority, support-weight]

dump:

pre

net-shaper-nl-cap-pre-dumpit

post

net-shaper-nl-cap-post-dumpit

request

attributes:

[ifindex]

reply

attributes:

[ifindex, scope, support-metric-bps, support-metric-pps, support-nesting, support-bw-min, support-bw-max, support-burst, support-priority, support-weight]

Definitions

scope

type:

enum

doc:

Defines the shaper @id interpretation.

entries:

unspec:

The scope is not specified.

netdev:

The main shaper for the given network device.

queue:

The shaper is attached to the given device queue, the @id represents the queue number.

node:

The shaper allows grouping of queues or other node shapers; can be nested in either @netdev shapers or other @node shapers, allowing placement in any location of the scheduling tree, except leaves and root.

metric

type:

enum

doc:

Different metric supported by the shaper.

entries:

bps:

Shaper operates on a bits per second basis.

pps:

Shaper operates on a packets per second basis.

Attribute sets

net-shaper

handle (nest)

nested-attributes:

handle

doc:

Unique identifier for the given shaper inside the owning device.

metric (u32)

enum:

metric

doc:

Metric used by the given shaper for bw-min, bw-max and burst.

bw-min (uint)

doc:

Guaranteed bandwidth for the given shaper.

bw-max (uint)

doc:

Maximum bandwidth for the given shaper or 0 when unlimited.

burst (uint)

doc:

Maximum burst-size for shaping. Should not be interpreted as a quantum.

priority (u32)

doc:

Scheduling priority for the given shaper. The priority scheduling is applied to sibling shapers.

weight (u32)

doc:

Relative weight for round robin scheduling of the given shaper. The scheduling is applied to all sibling shapers with the same priority.

ifindex (u32)

doc:

Interface index owning the specified shaper.

parent (nest)

nested-attributes:

handle

doc:

Identifier for the parent of the affected shaper. Only needed for @group operation.

leaves (nest)

multi-attr:

True

nested-attributes:

leaf-info

doc:

Describes a set of leaves shapers for a @group operation.

handle

scope (u32)

enum:

scope

doc:

Defines the shaper @id interpretation.

id (u32)

doc:

Numeric identifier of a shaper. The id semantic depends on the scope. For @queue scope it’s the queue id and for @node scope it’s the node identifier.

leaf-info

handle

priority

weight

caps

ifindex (u32)

doc:

Interface index queried for shapers capabilities.

scope (u32)

enum:

scope

doc:

The scope to which the queried capabilities apply.

support-metric-bps (flag)

doc:

The device accepts ‘bps’ metric for bw-min, bw-max and burst.

support-metric-pps (flag)

doc:

The device accepts ‘pps’ metric for bw-min, bw-max and burst.

support-nesting (flag)

doc:

The device supports nesting shaper belonging to this scope below ‘node’ scoped shapers. Only ‘queue’ and ‘node’ scope can have flag ‘support-nesting’.

support-bw-min (flag)

doc:

The device supports a minimum guaranteed B/W.

support-bw-max (flag)

doc:

The device supports maximum B/W shaping.

support-burst (flag)

doc:

The device supports a maximum burst size.

support-priority (flag)

doc:

The device supports priority scheduling.

support-weight (flag)

doc:

The device supports weighted round robin scheduling.