wgengine: don't create duplicate iptables rules on Linux, clean up

Fixes #131

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick
2020-03-03 12:38:51 -08:00
committed by Brad Fitzpatrick
parent 21fc5ec371
commit 89a2c3eb04
3 changed files with 44 additions and 17 deletions

View File

@ -14,6 +14,7 @@ import (
"path/filepath"
"strings"
"github.com/coreos/go-iptables/iptables"
"github.com/tailscale/wireguard-go/device"
"github.com/tailscale/wireguard-go/tun"
"github.com/tailscale/wireguard-go/wgcfg"
@ -26,6 +27,8 @@ type linuxRouter struct {
tunname string
local wgcfg.CIDR
routes map[wgcfg.CIDR]struct{}
ipt4 *iptables.IPTables
}
func newUserspaceRouter(logf logger.Logf, _ *device.Device, tunDev tun.Device) (Router, error) {
@ -34,9 +37,15 @@ func newUserspaceRouter(logf logger.Logf, _ *device.Device, tunDev tun.Device) (
return nil, err
}
ipt4, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
if err != nil {
return nil, err
}
return &linuxRouter{
logf: logf,
tunname: tunname,
ipt4: ipt4,
}, nil
}
@ -55,22 +64,13 @@ func (r *linuxRouter) Up() error {
log.Fatalf("running ip link failed: %v\n%s", err, out)
}
// TODO(apenwarr): This never cleans up after itself!
out, err = cmd("iptables",
"-A", "FORWARD",
"-i", r.tunname,
"-j", "ACCEPT").CombinedOutput()
err = r.ipt4.AppendUnique("filter", "FORWARD", r.forwardRule()...)
if err != nil {
r.logf("iptables forward failed: %v\n%s", err, out)
r.logf("iptables forward failed: %v", err)
}
// TODO(apenwarr): hardcoded eth0 interface is obviously not right.
out, err = cmd("iptables",
"-t", "nat",
"-A", "POSTROUTING",
"-o", "eth0",
"-j", "MASQUERADE").CombinedOutput()
err = r.ipt4.AppendUnique("nat", "POSTROUTING", r.natRule()...)
if err != nil {
r.logf("iptables nat failed: %v\n%s", err, out)
r.logf("iptables nat failed: %v", err)
}
return nil
}
@ -158,15 +158,39 @@ func (r *linuxRouter) SetRoutes(rs RouteSettings) error {
return errq
}
func (r *linuxRouter) forwardRule() []string {
return []string{
"-m", "comment", "--comment", "tailscale",
"-i", r.tunname,
"-j", "ACCEPT",
}
}
func (r *linuxRouter) natRule() []string {
// TODO(apenwarr): hardcoded eth0 interface is obviously not right.
return []string{
"-m", "comment", "--comment", "tailscale",
"-o", "eth0",
"-j", "MASQUERADE",
}
}
func (r *linuxRouter) Close() error {
var ret error
if err := r.restoreResolvConf(); err != nil {
r.logf("failed to restore system resolv.conf: %v", err)
if ret == nil {
set := func(err error) {
if ret == nil && err != nil {
ret = err
}
}
// TODO(apenwarr): clean up iptables etc.
if err := r.restoreResolvConf(); err != nil {
r.logf("failed to restore system resolv.conf: %v", err)
set(err)
}
set(r.ipt4.Delete("filter", "FORWARD", r.forwardRule()...))
set(r.ipt4.Delete("nat", "POSTROUTING", r.natRule()...))
// TODO(apenwarr): clean up routes etc.
return ret
}