netns

Documentation

Overview

Package netns contains the common code for using the Go net package in a logical "network namespace" to avoid routing loops where Tailscale-created packets would otherwise loop back through Tailscale routes.

Despite the name netns, the exact mechanism used differs by operating system, and perhaps even by version of the OS.

The netns package also handles connecting via SOCKS proxies when configured by the environment.

Index

• func IsSOCKSDialer(d Dialer) bool
• func Listener(logf logger.Logf, netMon *netmon.Monitor) *net.ListenConfig
• func SetBindToInterfaceByRoute(v bool)
• func SetDisableBindConnToInterface(v bool)
• func SetEnabled(on bool)
• func UseSocketMark() bool
• type Dialer
  • func FromDialer(logf logger.Logf, netMon *netmon.Monitor, d *net.Dialer) Dialer
  • func NewDialer(logf logger.Logf, netMon *netmon.Monitor) Dialer

Functions

func IsSOCKSDialer

func IsSOCKSDialer(d Dialer) bool

IsSOCKSDialer reports whether d is SOCKS-proxying dialer as returned by NewDialer or FromDialer.

func Listener

func Listener(logf logger.Logf, netMon *netmon.Monitor) *net.ListenConfig

Listener returns a new net.Listener with its Control hook func initialized as necessary to run in logical network namespace that doesn't route back into Tailscale. The netMon parameter is optional; if non-nil it's used to do faster interface lookups.

func SetBindToInterfaceByRoute

func SetBindToInterfaceByRoute(v bool)

SetBindToInterfaceByRoute enables or disables whether we use the system's route information to bind to a particular interface. It is the same as setting the TS_BIND_TO_INTERFACE_BY_ROUTE.

Currently, this only changes the behaviour on macOS.

func SetDisableBindConnToInterface

func SetDisableBindConnToInterface(v bool)

SetDisableBindConnToInterface disables the (normal) behavior of binding connections to the default network interface.

Currently, this only has an effect on Darwin.

func SetEnabled

func SetEnabled(on bool)

SetEnabled enables or disables netns for the process. It defaults to being enabled.

func UseSocketMark

func UseSocketMark() bool

UseSocketMark reports whether SO_MARK is in use. If it doesn't, we have to use SO_BINDTODEVICE on our sockets instead.

Types

type Dialer

type Dialer interface {
	Dial(network, address string) (net.Conn, error)
	DialContext(ctx context.Context, network, address string) (net.Conn, error)
}

Dialer is the interface for a dialer that can dial with or without a context. It's the type implemented both by net.Dialer and the Go SOCKS dialer.

func FromDialer

func FromDialer(logf logger.Logf, netMon *netmon.Monitor, d *net.Dialer) Dialer

FromDialer returns sets d.Control as necessary to run in a logical network namespace that doesn't route back into Tailscale. It also handles using a SOCKS if configured in the environment with ALL_PROXY. The netMon parameter is optional; if non-nil it's used to do faster interface lookups.

func NewDialer

func NewDialer(logf logger.Logf, netMon *netmon.Monitor) Dialer

NewDialer returns a new Dialer using a net.Dialer with its Control hook func initialized as necessary to run in a logical network namespace that doesn't route back into Tailscale. It also handles using a SOCKS if configured in the environment with ALL_PROXY. The netMon parameter is optional; if non-nil it's used to do faster interface lookups.