ceremonyclient/go-libp2p/p2p/host/autonat/dialpolicy.go
2023-08-20 23:07:43 -05:00

96 lines
2.2 KiB
Go

package autonat
import (
"net"
"github.com/libp2p/go-libp2p/core/host"
ma "github.com/multiformats/go-multiaddr"
manet "github.com/multiformats/go-multiaddr/net"
)
type dialPolicy struct {
allowSelfDials bool
host host.Host
}
// skipDial indicates that a multiaddress isn't worth attempted dialing.
// The same logic is used when the autonat client is considering if
// a remote peer is worth using as a server, and when the server is
// considering if a requested client is worth dialing back.
func (d *dialPolicy) skipDial(addr ma.Multiaddr) bool {
// skip relay addresses
_, err := addr.ValueForProtocol(ma.P_CIRCUIT)
if err == nil {
return true
}
if d.allowSelfDials {
return false
}
// skip private network (unroutable) addresses
if !manet.IsPublicAddr(addr) {
return true
}
candidateIP, err := manet.ToIP(addr)
if err != nil {
return true
}
// Skip dialing addresses we believe are the local node's
for _, localAddr := range d.host.Addrs() {
localIP, err := manet.ToIP(localAddr)
if err != nil {
continue
}
if localIP.Equal(candidateIP) {
return true
}
}
return false
}
// skipPeer indicates that the collection of multiaddresses representing a peer
// isn't worth attempted dialing. If one of the addresses matches an address
// we believe is ours, we exclude the peer, even if there are other valid
// public addresses in the list.
func (d *dialPolicy) skipPeer(addrs []ma.Multiaddr) bool {
localAddrs := d.host.Addrs()
localHosts := make([]net.IP, 0)
for _, lAddr := range localAddrs {
if _, err := lAddr.ValueForProtocol(ma.P_CIRCUIT); err != nil && manet.IsPublicAddr(lAddr) {
lIP, err := manet.ToIP(lAddr)
if err != nil {
continue
}
localHosts = append(localHosts, lIP)
}
}
// if a public IP of the peer is one of ours: skip the peer.
goodPublic := false
for _, addr := range addrs {
if _, err := addr.ValueForProtocol(ma.P_CIRCUIT); err != nil && manet.IsPublicAddr(addr) {
aIP, err := manet.ToIP(addr)
if err != nil {
continue
}
for _, lIP := range localHosts {
if lIP.Equal(aIP) {
return true
}
}
goodPublic = true
}
}
if d.allowSelfDials {
return false
}
return !goodPublic
}