feat: nftables support (#50)

* feat: nftables support

* fix: format
This commit is contained in:
Toby 2024-02-11 13:04:49 -08:00 committed by GitHub
parent 36bb4b796d
commit 27c9b91a61
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@ -4,7 +4,10 @@ import (
"context"
"encoding/binary"
"errors"
"fmt"
"os/exec"
"strconv"
"strings"
"github.com/coreos/go-iptables/iptables"
"github.com/florianl/go-nfqueue"
@ -18,8 +21,50 @@ const (
nfqueueConnMarkAccept = 1001
nfqueueConnMarkDrop = 1002
nftFamily = "inet"
nftTable = "opengfw"
)
var nftRulesForward = fmt.Sprintf(`
define ACCEPT_CTMARK=%d
define DROP_CTMARK=%d
define QUEUE_NUM=%d
table %s %s {
chain FORWARD {
type filter hook forward priority filter; policy accept;
ct mark $ACCEPT_CTMARK counter accept
ct mark $DROP_CTMARK counter drop
counter queue num $QUEUE_NUM bypass
}
}
`, nfqueueConnMarkAccept, nfqueueConnMarkDrop, nfqueueNum, nftFamily, nftTable)
var nftRulesLocal = fmt.Sprintf(`
define ACCEPT_CTMARK=%d
define DROP_CTMARK=%d
define QUEUE_NUM=%d
table %s %s {
chain INPUT {
type filter hook input priority filter; policy accept;
ct mark $ACCEPT_CTMARK counter accept
ct mark $DROP_CTMARK counter drop
counter queue num $QUEUE_NUM bypass
}
chain OUTPUT {
type filter hook output priority filter; policy accept;
ct mark $ACCEPT_CTMARK counter accept
ct mark $DROP_CTMARK counter drop
counter queue num $QUEUE_NUM bypass
}
}
`, nfqueueConnMarkAccept, nfqueueConnMarkDrop, nfqueueNum, nftFamily, nftTable)
var iptRulesForward = []iptRule{
{"filter", "FORWARD", []string{"-m", "connmark", "--mark", strconv.Itoa(nfqueueConnMarkAccept), "-j", "ACCEPT"}},
{"filter", "FORWARD", []string{"-m", "connmark", "--mark", strconv.Itoa(nfqueueConnMarkDrop), "-j", "DROP"}},
@ -43,9 +88,11 @@ var errNotNFQueuePacket = errors.New("not an NFQueue packet")
type nfqueuePacketIO struct {
n *nfqueue.Nfqueue
local bool
rSet bool // whether the nftables/iptables rules have been set
// iptables not nil = use iptables instead of nftables
ipt4 *iptables.IPTables
ipt6 *iptables.IPTables
iptSet bool // whether iptables rules are set
}
type NFQueuePacketIOConfig struct {
@ -57,14 +104,19 @@ func NewNFQueuePacketIO(config NFQueuePacketIOConfig) (PacketIO, error) {
if config.QueueSize == 0 {
config.QueueSize = nfqueueDefaultQueueSize
}
ipt4, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
var ipt4, ipt6 *iptables.IPTables
var err error
if nftCheck() != nil {
// We prefer nftables, but if it's not available, fall back to iptables
ipt4, err = iptables.NewWithProtocol(iptables.ProtocolIPv4)
if err != nil {
return nil, err
}
ipt6, err := iptables.NewWithProtocol(iptables.ProtocolIPv6)
ipt6, err = iptables.NewWithProtocol(iptables.ProtocolIPv6)
if err != nil {
return nil, err
}
}
n, err := nfqueue.Open(&nfqueue.Config{
NfQueue: nfqueueNum,
MaxPacketLen: nfqueueMaxPacketLen,
@ -104,12 +156,16 @@ func (n *nfqueuePacketIO) Register(ctx context.Context, cb PacketCallback) error
if err != nil {
return err
}
if !n.iptSet {
if !n.rSet {
if n.ipt4 != nil {
err = n.setupIpt(n.local, false)
} else {
err = n.setupNft(n.local, false)
}
if err != nil {
return err
}
n.iptSet = true
n.rSet = true
}
return nil
}
@ -136,6 +192,39 @@ func (n *nfqueuePacketIO) SetVerdict(p Packet, v Verdict, newPacket []byte) erro
}
}
func (n *nfqueuePacketIO) Close() error {
if n.rSet {
if n.ipt4 != nil {
_ = n.setupIpt(n.local, true)
} else {
_ = n.setupNft(n.local, true)
}
n.rSet = false
}
return n.n.Close()
}
func (n *nfqueuePacketIO) setupNft(local, remove bool) error {
var rules string
if local {
rules = nftRulesLocal
} else {
rules = nftRulesForward
}
var err error
if remove {
err = nftDelete(nftFamily, nftTable)
} else {
// Delete first to make sure no leftover rules
_ = nftDelete(nftFamily, nftTable)
err = nftAdd(rules)
}
if err != nil {
return err
}
return nil
}
func (n *nfqueuePacketIO) setupIpt(local, remove bool) error {
var rules []iptRule
if local {
@ -155,16 +244,6 @@ func (n *nfqueuePacketIO) setupIpt(local, remove bool) error {
return nil
}
func (n *nfqueuePacketIO) Close() error {
if n.iptSet {
err := n.setupIpt(n.local, true)
if err != nil {
return err
}
}
return n.n.Close()
}
var _ Packet = (*nfqueuePacket)(nil)
type nfqueuePacket struct {
@ -189,6 +268,25 @@ func okBoolToInt(ok bool) int {
}
}
func nftCheck() error {
_, err := exec.LookPath("nft")
if err != nil {
return err
}
return nil
}
func nftAdd(input string) error {
cmd := exec.Command("nft", "-f", "-")
cmd.Stdin = strings.NewReader(input)
return cmd.Run()
}
func nftDelete(family, table string) error {
cmd := exec.Command("nft", "delete", "table", family, table)
return cmd.Run()
}
type iptRule struct {
Table, Chain string
RuleSpec []string