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tailscale/wgengine/router/router_userspace_bsd.go

171 lines
4.0 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.
// +build darwin freebsd
package router
import (
"errors"
"fmt"
"log"
"os/exec"
"github.com/tailscale/wireguard-go/device"
"github.com/tailscale/wireguard-go/tun"
"inet.af/netaddr"
"tailscale.com/types/logger"
"tailscale.com/version"
"tailscale.com/wgengine/router/dns"
)
type userspaceBSDRouter struct {
logf logger.Logf
tunname string
local netaddr.IPPrefix
routes map[netaddr.IPPrefix]struct{}
dns *dns.Manager
}
func newUserspaceBSDRouter(logf logger.Logf, _ *device.Device, tundev tun.Device) (Router, error) {
tunname, err := tundev.Name()
if err != nil {
return nil, err
}
mconfig := dns.ManagerConfig{
Logf: logf,
InterfaceName: tunname,
}
return &userspaceBSDRouter{
logf: logf,
tunname: tunname,
dns: dns.NewManager(mconfig),
}, nil
}
func cmd(args ...string) *exec.Cmd {
if len(args) == 0 {
log.Fatalf("exec.Cmd(%#v) invalid; need argv[0]\n", args)
}
return exec.Command(args[0], args[1:]...)
}
func (r *userspaceBSDRouter) Up() error {
ifup := []string{"ifconfig", r.tunname, "up"}
if out, err := cmd(ifup...).CombinedOutput(); err != nil {
r.logf("running ifconfig failed: %v\n%s", err, out)
return err
}
return nil
}
func (r *userspaceBSDRouter) Set(cfg *Config) error {
if cfg == nil {
cfg = &shutdownConfig
}
if len(cfg.LocalAddrs) == 0 {
return nil
}
// TODO: support configuring multiple local addrs on interface.
if len(cfg.LocalAddrs) != 1 {
return errors.New("freebsd doesn't support setting multiple local addrs yet")
}
localAddr := cfg.LocalAddrs[0]
var errq error
// Update the address.
if localAddr != r.local {
// If the interface is already set, remove it.
if r.local != (netaddr.IPPrefix{}) {
addrdel := []string{"ifconfig", r.tunname,
"inet", r.local.String(), "-alias"}
out, err := cmd(addrdel...).CombinedOutput()
if err != nil {
r.logf("addr del failed: %v: %v\n%s", addrdel, err, out)
if errq == nil {
errq = err
}
}
}
// Add the interface.
addradd := []string{"ifconfig", r.tunname,
"inet", localAddr.String(), localAddr.IP.String()}
out, err := cmd(addradd...).CombinedOutput()
if err != nil {
r.logf("addr add failed: %v: %v\n%s", addradd, err, out)
if errq == nil {
errq = err
}
}
}
newRoutes := make(map[netaddr.IPPrefix]struct{})
for _, route := range cfg.Routes {
newRoutes[route] = struct{}{}
}
// Delete any pre-existing routes.
for route := range r.routes {
if _, keep := newRoutes[route]; !keep {
net := route.IPNet()
nip := net.IP.Mask(net.Mask)
nstr := fmt.Sprintf("%v/%d", nip, route.Bits)
del := "del"
if version.OS() == "macOS" {
del = "delete"
}
routedel := []string{"route", "-q", "-n",
del, "-inet", nstr,
"-iface", r.tunname}
out, err := cmd(routedel...).CombinedOutput()
if err != nil {
r.logf("route del failed: %v: %v\n%s", routedel, err, out)
if errq == nil {
errq = err
}
}
}
}
// Add the routes.
for route := range newRoutes {
if _, exists := r.routes[route]; !exists {
net := route.IPNet()
nip := net.IP.Mask(net.Mask)
nstr := fmt.Sprintf("%v/%d", nip, route.Bits)
routeadd := []string{"route", "-q", "-n",
"add", "-inet", nstr,
"-iface", r.tunname}
out, err := cmd(routeadd...).CombinedOutput()
if err != nil {
r.logf("addr add failed: %v: %v\n%s", routeadd, err, out)
if errq == nil {
errq = err
}
}
}
}
// Store the interface and routes so we know what to change on an update.
r.local = localAddr
r.routes = newRoutes
if err := r.dns.Set(cfg.DNS); err != nil {
errq = fmt.Errorf("dns set: %v", err)
}
return errq
}
func (r *userspaceBSDRouter) Close() error {
if err := r.dns.Down(); err != nil {
r.logf("dns down: %v", err)
}
// No interface cleanup is necessary during normal shutdown.
return nil
}