tailscale/wgengine/router/router.go
Dmytro Shynkevych 30bbbe9467
wgengine/router: dns: unify on *BSD, multimode on Linux, Magic DNS (#536)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-14 09:12:00 -04:00

88 lines
2.7 KiB
Go

// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package router presents an interface to manipulate the host network
// stack's state.
package router
import (
"github.com/tailscale/wireguard-go/device"
"github.com/tailscale/wireguard-go/tun"
"inet.af/netaddr"
"tailscale.com/types/logger"
)
// Router is responsible for managing the system network stack.
//
// There is typically only one instance of this interface per process.
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
}
// New returns a new Router for the current platform, using the
// provided tun device.
func New(logf logger.Logf, wgdev *device.Device, tundev tun.Device) (Router, error) {
logf = logger.WithPrefix(logf, "router: ")
return newUserspaceRouter(logf, wgdev, tundev)
}
// 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.
func Cleanup(logf logger.Logf, interfaceName string) {
cleanup(logf, interfaceName)
}
// NetfilterMode is the firewall management mode to use when
// programming the Linux network stack.
type NetfilterMode int
const (
NetfilterOff NetfilterMode = iota // remove all tailscale netfilter state
NetfilterNoDivert // manage tailscale chains, but don't call them
NetfilterOn // manage tailscale chains and call them from main chains
)
func (m NetfilterMode) String() string {
switch m {
case NetfilterOff:
return "off"
case NetfilterNoDivert:
return "nodivert"
case NetfilterOn:
return "on"
default:
return "???"
}
}
// Config is the subset of Tailscale configuration that is relevant to
// the OS's network stack.
type Config struct {
LocalAddrs []netaddr.IPPrefix
Routes []netaddr.IPPrefix // routes to point into the Tailscale interface
DNSConfig
// Linux-only things below, ignored on other platforms.
SubnetRoutes []netaddr.IPPrefix // subnets being advertised to other Tailscale nodes
SNATSubnetRoutes bool // SNAT traffic to local subnets
NetfilterMode NetfilterMode // how much to manage netfilter rules
}
// shutdownConfig is a routing configuration that removes all router
// state from the OS. It's the config used when callers pass in a nil
// Config.
var shutdownConfig = Config{}