56 lines
1.5 KiB
Go
56 lines
1.5 KiB
Go
package eth
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import (
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"fmt"
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"net"
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natpmp "github.com/jackpal/go-nat-pmp"
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)
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// Adapt the NAT-PMP protocol to the NAT interface
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// TODO:
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// + Register for changes to the external address.
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// + Re-register port mapping when router reboots.
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// + A mechanism for keeping a port mapping registered.
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type natPMPClient struct {
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client *natpmp.Client
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}
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func NewNatPMP(gateway net.IP) (nat NAT) {
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return &natPMPClient{natpmp.NewClient(gateway)}
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}
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func (n *natPMPClient) GetExternalAddress() (addr net.IP, err error) {
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response, err := n.client.GetExternalAddress()
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if err != nil {
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return
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}
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ip := response.ExternalIPAddress
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addr = net.IPv4(ip[0], ip[1], ip[2], ip[3])
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return
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}
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func (n *natPMPClient) AddPortMapping(protocol string, externalPort, internalPort int,
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description string, timeout int) (mappedExternalPort int, err error) {
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if timeout <= 0 {
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err = fmt.Errorf("timeout must not be <= 0")
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return
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}
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// Note order of port arguments is switched between our AddPortMapping and the client's AddPortMapping.
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response, err := n.client.AddPortMapping(protocol, internalPort, externalPort, timeout)
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if err != nil {
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return
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}
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mappedExternalPort = int(response.MappedExternalPort)
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return
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}
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func (n *natPMPClient) DeletePortMapping(protocol string, externalPort, internalPort int) (err error) {
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// To destroy a mapping, send an add-port with
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// an internalPort of the internal port to destroy, an external port of zero and a time of zero.
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_, err = n.client.AddPortMapping(protocol, internalPort, 0, 0)
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return
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}
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