fix: netlink race condition (#48)

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Toby 2024-02-05 19:32:52 -08:00 committed by GitHub
parent 6871244809
commit 843f17896c
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GPG Key ID: B5690EEEBB952194

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@ -41,10 +41,11 @@ var _ PacketIO = (*nfqueuePacketIO)(nil)
var errNotNFQueuePacket = errors.New("not an NFQueue packet")
type nfqueuePacketIO struct {
n *nfqueue.Nfqueue
local bool
ipt4 *iptables.IPTables
ipt6 *iptables.IPTables
n *nfqueue.Nfqueue
local bool
ipt4 *iptables.IPTables
ipt6 *iptables.IPTables
iptSet bool // whether iptables rules are set
}
type NFQueuePacketIOConfig struct {
@ -74,22 +75,16 @@ func NewNFQueuePacketIO(config NFQueuePacketIOConfig) (PacketIO, error) {
if err != nil {
return nil, err
}
io := &nfqueuePacketIO{
return &nfqueuePacketIO{
n: n,
local: config.Local,
ipt4: ipt4,
ipt6: ipt6,
}
err = io.setupIpt(config.Local, false)
if err != nil {
_ = n.Close()
return nil, err
}
return io, nil
}, nil
}
func (n *nfqueuePacketIO) Register(ctx context.Context, cb PacketCallback) error {
return n.n.RegisterWithErrorFunc(ctx,
err := n.n.RegisterWithErrorFunc(ctx,
func(a nfqueue.Attribute) int {
if a.PacketID == nil || a.Ct == nil || a.Payload == nil || len(*a.Payload) < 20 {
// Invalid packet, ignore
@ -106,6 +101,17 @@ func (n *nfqueuePacketIO) Register(ctx context.Context, cb PacketCallback) error
func(e error) int {
return okBoolToInt(cb(nil, e))
})
if err != nil {
return err
}
if !n.iptSet {
err = n.setupIpt(n.local, false)
if err != nil {
return err
}
n.iptSet = true
}
return nil
}
func (n *nfqueuePacketIO) SetVerdict(p Packet, v Verdict, newPacket []byte) error {
@ -150,9 +156,13 @@ func (n *nfqueuePacketIO) setupIpt(local, remove bool) error {
}
func (n *nfqueuePacketIO) Close() error {
err := n.setupIpt(n.local, true)
_ = n.n.Close()
return err
if n.iptSet {
err := n.setupIpt(n.local, true)
if err != nil {
return err
}
}
return n.n.Close()
}
var _ Packet = (*nfqueuePacket)(nil)