router

Documentation

Overview

Package router presents an interface to manipulate the host network stack's state.

Index

• func Cleanup(logf logger.Logf, interfaceName string)
• type CallbackRouter
  • func (r *CallbackRouter) Close() error
  • func (r *CallbackRouter) GetBaseConfig() (dns.OSConfig, error)
  • func (r *CallbackRouter) Set(rcfg *Config) error
  • func (r *CallbackRouter) SetDNS(dcfg dns.OSConfig) error
  • func (r *CallbackRouter) SupportsSplitDNS() bool
  • func (r *CallbackRouter) Up() error
• type Config
  • func (a *Config) Equal(b *Config) bool
• type RouteTable
• type Router
  • func New(logf logger.Logf, tundev tun.Device, netMon *netmon.Monitor) (Router, error)
  • func NewFake(logf logger.Logf) Router

Functions

func Cleanup

func Cleanup(logf logger.Logf, interfaceName string)

Cleanup restores the system network configuration to its original state in case the Tailscale daemon terminated without closing the router. No other state needs to be instantiated before this runs.

Types

type CallbackRouter

type CallbackRouter struct {
	SetBoth  func(rcfg *Config, dcfg *dns.OSConfig) error
	SplitDNS bool

	// GetBaseConfigFunc optionally specifies a function to return the current DNS
	// config in response to GetBaseConfig.
	//
	// If nil, reading the current config isn't supported and GetBaseConfig()
	// will return ErrGetBaseConfigNotSupported.
	GetBaseConfigFunc func() (dns.OSConfig, error)

	// InitialMTU is the MTU the tun should be initialized with.
	// Zero means don't change the MTU from the default. This MTU
	// is applied only once, shortly after the TUN is created, and
	// ignored thereafter.
	InitialMTU uint32
	// contains filtered or unexported fields
}

CallbackRouter is an implementation of both Router and dns.OSConfigurator. When either network or DNS settings are changed, SetBoth is called with both configs. Mainly used as a shim for OSes that want to set both network and DNS configuration simultaneously (Mac, iOS, Android).

func (*CallbackRouter) Close

func (r *CallbackRouter) Close() error

func (*CallbackRouter) GetBaseConfig

func (r *CallbackRouter) GetBaseConfig() (dns.OSConfig, error)

func (*CallbackRouter) Set

func (r *CallbackRouter) Set(rcfg *Config) error

Set implements Router.

func (*CallbackRouter) SetDNS

func (r *CallbackRouter) SetDNS(dcfg dns.OSConfig) error

SetDNS implements dns.OSConfigurator.

func (*CallbackRouter) SupportsSplitDNS

func (r *CallbackRouter) SupportsSplitDNS() bool

SupportsSplitDNS implements dns.OSConfigurator.

func (*CallbackRouter) Up

func (r *CallbackRouter) Up() error

Up implements Router.

type Config

type Config struct {
	// LocalAddrs are the address(es) for this node. This is
	// typically one IPv4/32 (the 100.x.y.z CGNAT) and one
	// IPv6/128 (Tailscale ULA).
	LocalAddrs []netip.Prefix

	// Routes are the routes that point into the Tailscale
	// interface.  These are the /32 and /128 routes to peers, as
	// well as any other subnets that peers are advertising and
	// this node has chosen to use.
	Routes []netip.Prefix

	// LocalRoutes are the routes that should not be routed through Tailscale.
	// There are no priorities set in how these routes are added, normal
	// routing rules apply.
	LocalRoutes []netip.Prefix

	// NewMTU is currently only used by the MacOS network extension
	// app to set the MTU of the tun in the router configuration
	// callback. If zero, the MTU is unchanged.
	NewMTU int

	// Linux-only things below, ignored on other platforms.
	SubnetRoutes     []netip.Prefix         // subnets being advertised to other Tailscale nodes
	SNATSubnetRoutes bool                   // SNAT traffic to local subnets
	NetfilterMode    preftype.NetfilterMode // how much to manage netfilter rules
}

Config is the subset of Tailscale configuration that is relevant to the OS's network stack.

func (*Config) Equal

func (a *Config) Equal(b *Config) bool

type RouteTable

type RouteTable struct {
	Name string
	Num  int
}

RouteTable is a Linux routing table: both its name and number. See /etc/iproute2/rt_tables.

type Router

type Router interface {
	// Up brings the router up.
	Up() error

	// Set updates the OS network stack with a new Config. It may be
	// called multiple times with identical Configs, which the
	// implementation should handle gracefully.
	Set(*Config) error

	// Close closes the router.
	Close() error
}

Router is responsible for managing the system network stack.

There is typically only one instance of this interface per process.

func New

func New(logf logger.Logf, tundev tun.Device, netMon *netmon.Monitor) (Router, error)

New returns a new Router for the current platform, using the provided tun device.

If netMon is nil, it's not used. It's currently (2021-07-20) only used on Linux in some situations.

func NewFake

func NewFake(logf logger.Logf) Router

NewFake returns a Router that does nothing when called and always returns nil errors.