interfaces

Documentation

Overview

Package interfaces contains helpers for looking up system network interfaces.

Index

• Variables
• func DefaultRouteInterface() (string, error)
• func FilterAll(i Interface, ips []netaddr.IPPrefix) bool
• func FilterInteresting(i Interface, ips []netaddr.IPPrefix) bool
• func ForeachInterface(fn func(Interface, []netaddr.IPPrefix)) error
• func ForeachInterfaceAddress(fn func(Interface, netaddr.IPPrefix)) error
• func HTTPOfListener(ln net.Listener) string
• func LikelyHomeRouterIP() (gateway, myIP netaddr.IP, ok bool)
• func LocalAddresses() (regular, loopback []netaddr.IP, err error)
• func RegisterInterfaceGetter(getInterfaces func() ([]Interface, error))
• func Tailscale() ([]netaddr.IP, *net.Interface, error)
• type Interface
  • func (i Interface) Addrs() ([]net.Addr, error)
  • func (i Interface) IsLoopback() bool
  • func (i Interface) IsUp() bool
• type State
  • func GetState() (*State, error)
  • func (s *State) AnyInterfaceUp() bool
  • func (s *State) EqualFiltered(s2 *State, filter func(i Interface, ips []netaddr.IPPrefix) bool) bool
  • func (s *State) HasPAC() bool
  • func (s *State) String() string

Variables

var LoginEndpointForProxyDetermination = "https://controlplane.tailscale.com/"

LoginEndpointForProxyDetermination is the URL used for testing which HTTP proxy the system should use.

Functions

func DefaultRouteInterface

func DefaultRouteInterface() (string, error)

DefaultRouteInterface returns the name of the network interface that owns the default route, not including any tailscale interfaces.

func FilterAll

func FilterAll(i Interface, ips []netaddr.IPPrefix) bool

FilterAll always returns true, to use EqualFiltered against all interfaces.

func FilterInteresting

func FilterInteresting(i Interface, ips []netaddr.IPPrefix) bool

FilterInteresting reports whether i is an interesting non-Tailscale interface.

func ForeachInterface

func ForeachInterface(fn func(Interface, []netaddr.IPPrefix)) error

ForeachInterface calls fn for each interface on the machine, with all its addresses. The IPPrefix's IP is the IP address assigned to the interface, and Bits are the subnet mask.

func ForeachInterfaceAddress

func ForeachInterfaceAddress(fn func(Interface, netaddr.IPPrefix)) error

ForeachInterfaceAddress calls fn for each interface's address on the machine. The IPPrefix's IP is the IP address assigned to the interface, and Bits are the subnet mask.

func HTTPOfListener

func HTTPOfListener(ln net.Listener) string

HTTPOfListener returns the HTTP address to ln. If the listener is listening on the unspecified address, it it tries to find a reasonable interface address on the machine to use.

func LikelyHomeRouterIP

func LikelyHomeRouterIP() (gateway, myIP netaddr.IP, ok bool)

LikelyHomeRouterIP returns the likely IP of the residential router, which will always be an IPv4 private address, if found. In addition, it returns the IP address of the current machine on the LAN using that gateway. This is used as the destination for UPnP, NAT-PMP, PCP, etc queries.

func LocalAddresses

func LocalAddresses() (regular, loopback []netaddr.IP, err error)

LocalAddresses returns the machine's IP addresses, separated by whether they're loopback addresses. If there are no regular addresses it will return any IPv4 linklocal or IPv6 unique local addresses because we know of environments where these are used with NAT to provide connectivity.

func RegisterInterfaceGetter

func RegisterInterfaceGetter(getInterfaces func() ([]Interface, error))

RegisterInterfaceGetter sets the function that's used to query the system network interfaces.

func Tailscale

func Tailscale() ([]netaddr.IP, *net.Interface, error)

Tailscale returns the current machine's Tailscale interface, if any. If none is found, all zero values are returned. A non-nil error is only returned on a problem listing the system interfaces.

Types

type Interface

type Interface struct {
	*net.Interface
	AltAddrs []net.Addr // if non-nil, returned by Addrs
}

Interface is a wrapper around Go's net.Interface with some extra methods.

func (Interface) Addrs

func (i Interface) Addrs() ([]net.Addr, error)

func (Interface) IsLoopback

func (i Interface) IsLoopback() bool

func (Interface) IsUp

func (i Interface) IsUp() bool

type State

type State struct {
	// InterfaceIPs maps from an interface name to the IP addresses
	// configured on that interface. Each address is represented as an
	// IPPrefix, where the IP is the interface IP address and Bits is
	// the subnet mask.
	InterfaceIPs map[string][]netaddr.IPPrefix
	Interface    map[string]Interface

	// HaveV6 is whether this machine has an IPv6 Global or Unique Local Address
	// which might provide connectivity on a non-Tailscale interface that's up.
	HaveV6 bool

	// HaveV4 is whether the machine has some non-localhost,
	// non-link-local IPv4 address on a non-Tailscale interface that's up.
	HaveV4 bool

	// IsExpensive is whether the current network interface is
	// considered "expensive", which currently means LTE/etc
	// instead of Wifi. This field is not populated by GetState.
	IsExpensive bool

	// DefaultRouteInterface is the interface name for the machine's default route.
	// It is not yet populated on all OSes.
	// Its exact value should not be assumed to be a map key for
	// the Interface maps above; it's only used for debugging.
	DefaultRouteInterface string

	// HTTPProxy is the HTTP proxy to use.
	HTTPProxy string

	// PAC is the URL to the Proxy Autoconfig URL, if applicable.
	PAC string
}

State is intended to store the state of the machine's network interfaces, routing table, and other network configuration. For now it's pretty basic.

func GetState

func GetState() (*State, error)

GetState returns the state of all the current machine's network interfaces.

It does not set the returned State.IsExpensive. The caller can populate that.

func (*State) AnyInterfaceUp

func (s *State) AnyInterfaceUp() bool

AnyInterfaceUp reports whether any interface seems like it has Internet access.

func (*State) EqualFiltered

func (s *State) EqualFiltered(s2 *State, filter func(i Interface, ips []netaddr.IPPrefix) bool) bool

EqualFiltered reports whether s and s2 are equal, considering only interfaces in s for which filter returns true.

func (*State) HasPAC

func (s *State) HasPAC() bool

func (*State) String

func (s *State) String() string