route

Documentation

Overview

Package route provides the Cilium specific abstraction and useful helpers to manage network routes

Index

• Constants
• func Delete(route Route) error
• func DeleteRule(spec Rule) error
• func DeleteRuleIPv6(spec Rule) error
• func NodeDeviceWithDefaultRoute() (netlink.Link, error)
• func ReplaceRule(spec Rule) error
• func ReplaceRuleIPv6(spec Rule) error
• func Upsert(route Route) (bool, error)
• type ByMask
  • func (a ByMask) Len() int
  • func (a ByMask) Less(i, j int) bool
  • func (a ByMask) Swap(i, j int)
• type Route
  • func Lookup(route Route) (*Route, error)
  • func (r *Route) LogFields() logrus.Fields
  • func (r *Route) ToIPCommand(dev string) []string
• type Rule

Constants

const (
	// RouteReplaceMaxTries is the number of attempts the route will be
	// attempted to be added or updated in case the kernel returns an error
	RouteReplaceMaxTries = 10

	// RouteReplaceRetryInterval is the interval in which
	// RouteReplaceMaxTries attempts are attempted
	RouteReplaceRetryInterval = 100 * time.Millisecond

	// RTN_LOCAL is a route type used to indicate packet should be "routed"
	// locally and passed up the stack. Is used by IPSec to force encrypted
	// packets to pass through XFRM layer.
	RTN_LOCAL = 0x2

	// MainTable is Linux's default routing table
	MainTable = 254

	// EncryptRouteProtocol for Encryption specific routes
	EncryptRouteProtocol = 192
)

Functions

func Delete

func Delete(route Route) error

Delete deletes a Linux route. An error is returned if the route does not exist or if the route could not be deleted.

func DeleteRule

func DeleteRule(spec Rule) error

DeleteRule delete a mark based rule from the routing table.

func DeleteRuleIPv6

func DeleteRuleIPv6(spec Rule) error

DeleteRuleIPv6 delete a mark based IPv6 rule from the routing table.

func NodeDeviceWithDefaultRoute

func NodeDeviceWithDefaultRoute() (netlink.Link, error)

NodeDeviceWithDefaultRoute returns the node's device which handles the default route in the current namespace

func ReplaceRule

func ReplaceRule(spec Rule) error

ReplaceRule add or replace rule in the routing table using a mark to indicate table. Used with BPF datapath to set mark and direct packets to route table.

func ReplaceRuleIPv6

func ReplaceRuleIPv6(spec Rule) error

ReplaceRuleIPv6 add or replace IPv6 rule in the routing table using a mark to indicate table.

func Upsert

func Upsert(route Route) (bool, error)

Upsert adds or updates a Linux kernel route. The route described can be in the following two forms:

direct:

prefix dev foo

nexthop:

prefix via nexthop dev foo

If a nexthop route is specified, this function will check whether a direct route to the nexthop exists and add if required. This means that the following two routes will exist afterwards:

nexthop dev foo
prefix via nexthop dev foo

Due to a bug in the Linux kernel, the prefix route is attempted to be updated RouteReplaceMaxTries with an interval of RouteReplaceRetryInterval. This is a workaround for a race condition in which the direct route to the nexthop is not available immediately and the prefix route can fail with EINVAL if the Netlink calls are issued in short order.

An error is returned if the route can not be added or updated.

Types

type ByMask

type ByMask []Route

ByMask is used to sort an array of routes by mask, narrow first.

func (ByMask) Len

func (a ByMask) Len() int

func (ByMask) Less

func (a ByMask) Less(i, j int) bool

func (ByMask) Swap

func (a ByMask) Swap(i, j int)

type Route

type Route struct {
	Prefix  net.IPNet
	Nexthop *net.IP
	Local   net.IP
	Device  string
	MTU     int
	Proto   int
	Scope   netlink.Scope
	Table   int
	Type    int
}

func Lookup

func Lookup(route Route) (*Route, error)

Lookup attempts to find the linux route based on the route specification. If the route exists, the route is returned, otherwise an error is returned.

func (*Route) LogFields

func (r *Route) LogFields() logrus.Fields

LogFields returns the route attributes as logrus.Fields map

func (*Route) ToIPCommand

func (r *Route) ToIPCommand(dev string) []string

ToIPCommand converts the route into a full "ip route ..." command

type Rule

type Rule struct {
	// Priority is the routing rule priority
	Priority int

	// Mark is the skb mark that needs to match
	Mark int

	// Mask is the mask to apply to the skb mark before matching the Mark
	// field
	Mask int

	// From is the source address selector
	From *net.IPNet

	// To is the destination address selector
	To *net.IPNet

	// Table is the routing table to look up if the rule matches
	Table int
}

Rule is the specification of an IP routing rule