90 lines
2.0 KiB
Go
90 lines
2.0 KiB
Go
package relay
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import (
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"context"
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"fmt"
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"math/rand"
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peer "github.com/libp2p/go-libp2p-peer"
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pstore "github.com/libp2p/go-libp2p-peerstore"
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tpt "github.com/libp2p/go-libp2p-transport"
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ma "github.com/multiformats/go-multiaddr"
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)
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func (d *RelayTransport) Dial(ctx context.Context, a ma.Multiaddr, p peer.ID) (tpt.Conn, error) {
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c, err := d.Relay().Dial(ctx, a)
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if err != nil {
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return nil, err
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}
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return d.upgrader.UpgradeOutbound(ctx, d, c, p)
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}
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func (r *Relay) Dial(ctx context.Context, a ma.Multiaddr) (*Conn, error) {
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if !r.Matches(a) {
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return nil, fmt.Errorf("%s is not a relay address", a)
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}
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parts := ma.Split(a)
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spl, _ := ma.NewMultiaddr("/p2p-circuit")
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var relayaddr, destaddr ma.Multiaddr
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for i, p := range parts {
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if p.Equal(spl) {
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relayaddr = ma.Join(parts[:i]...)
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destaddr = ma.Join(parts[i+1:]...)
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break
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}
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}
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dinfo, err := pstore.InfoFromP2pAddr(destaddr)
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if err != nil {
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return nil, err
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}
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if len(relayaddr.Bytes()) == 0 {
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// unspecific relay address, try dialing using known hop relays
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return r.tryDialRelays(ctx, *dinfo)
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}
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var rinfo *pstore.PeerInfo
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rinfo, err = pstore.InfoFromP2pAddr(relayaddr)
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if err != nil {
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return nil, err
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}
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return r.DialPeer(ctx, *rinfo, *dinfo)
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}
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func (r *Relay) tryDialRelays(ctx context.Context, dinfo pstore.PeerInfo) (*Conn, error) {
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var relays []peer.ID
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r.mx.Lock()
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for p := range r.relays {
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relays = append(relays, p)
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}
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r.mx.Unlock()
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// shuffle list of relays, avoid overloading a specific relay
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for i := range relays {
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j := rand.Intn(i + 1)
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relays[i], relays[j] = relays[j], relays[i]
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}
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for _, relay := range relays {
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if len(r.host.Network().ConnsToPeer(relay)) == 0 {
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continue
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}
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rctx, cancel := context.WithTimeout(ctx, HopConnectTimeout)
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c, err := r.DialPeer(rctx, pstore.PeerInfo{ID: relay}, dinfo)
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cancel()
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if err == nil {
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return c, nil
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}
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log.Debugf("error opening relay connection through %s: %s", dinfo.ID, err.Error())
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}
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return nil, fmt.Errorf("Failed to dial through %d known relay hosts", len(relays))
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}
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