From 1ad785cc023fc33f8a4fd0fdc3f0177992afde84 Mon Sep 17 00:00:00 2001
From: vyzo <vyzo@hackzen.org>
Date: Sat, 5 May 2018 16:45:58 +0300
Subject: [PATCH] basic client

---
 p2p/host/autonat/client.go | 83 ++++++++++++++++++++++++++++++++++++++
 p2p/host/autonat/proto.go  | 23 +++++++++++
 2 files changed, 106 insertions(+)
 create mode 100644 p2p/host/autonat/client.go
 create mode 100644 p2p/host/autonat/proto.go

diff --git a/p2p/host/autonat/client.go b/p2p/host/autonat/client.go
new file mode 100644
index 00000000..6709abcd
--- /dev/null
+++ b/p2p/host/autonat/client.go
@@ -0,0 +1,83 @@
+package autonat
+
+import (
+	"context"
+	"fmt"
+
+	pb "github.com/libp2p/go-libp2p-autonat/pb"
+
+	ggio "github.com/gogo/protobuf/io"
+	host "github.com/libp2p/go-libp2p-host"
+	inet "github.com/libp2p/go-libp2p-net"
+	peer "github.com/libp2p/go-libp2p-peer"
+	pstore "github.com/libp2p/go-libp2p-peerstore"
+	ma "github.com/multiformats/go-multiaddr"
+)
+
+type AutoNATClient interface {
+	Dial(ctx context.Context) (ma.Multiaddr, error)
+}
+
+type AutoNATError struct {
+	Status pb.Message_ResponseStatus
+	Text   string
+}
+
+func NewAutoNATClient(h host.Host, p peer.ID) AutoNATClient {
+	return &client{h: h, p: p}
+}
+
+type client struct {
+	h host.Host
+	p peer.ID
+}
+
+func (c *client) Dial(ctx context.Context) (ma.Multiaddr, error) {
+	s, err := c.h.NewStream(ctx, c.p, AutoNATProto)
+	if err != nil {
+		return nil, err
+	}
+	defer s.Close()
+
+	r := ggio.NewDelimitedReader(s, inet.MessageSizeMax)
+	w := ggio.NewDelimitedWriter(s)
+
+	req := newDialMessage(pstore.PeerInfo{ID: c.h.ID(), Addrs: c.h.Addrs()})
+	err = w.WriteMsg(req)
+	if err != nil {
+		return nil, err
+	}
+
+	var res pb.Message
+	err = r.ReadMsg(&res)
+	if err != nil {
+		return nil, err
+	}
+
+	if res.GetType() != pb.Message_DIAL_RESPONSE {
+		return nil, fmt.Errorf("Unexpected response: %s", res.GetType().String())
+	}
+
+	status := res.GetDialResponse().GetStatus()
+	switch status {
+	case pb.Message_OK:
+		addr := res.GetDialResponse().GetAddr()
+		return ma.NewMultiaddrBytes(addr)
+
+	default:
+		return nil, AutoNATError{Status: status, Text: res.GetDialResponse().GetStatusText()}
+	}
+}
+
+func (e AutoNATError) Error() string {
+	return fmt.Sprintf("AutoNAT error: %s (%s)", e.Text, e.Status.String())
+}
+
+func (e AutoNATError) IsDialError() bool {
+	return e.Status == pb.Message_E_DIAL_ERROR
+}
+
+func IsDialError(e error) bool {
+	ae, ok := e.(AutoNATError)
+	return ok && ae.IsDialError()
+}
diff --git a/p2p/host/autonat/proto.go b/p2p/host/autonat/proto.go
new file mode 100644
index 00000000..142469ce
--- /dev/null
+++ b/p2p/host/autonat/proto.go
@@ -0,0 +1,23 @@
+package autonat
+
+import (
+	pb "github.com/libp2p/go-libp2p-autonat/pb"
+
+	pstore "github.com/libp2p/go-libp2p-peerstore"
+)
+
+const AutoNATProto = "/autonat/1.0.0"
+
+func newDialMessage(pi pstore.PeerInfo) *pb.Message {
+	msg := new(pb.Message)
+	msg.Type = pb.Message_DIAL.Enum()
+	msg.Dial = new(pb.Message_Dial)
+	msg.Dial.Peer = new(pb.Message_PeerInfo)
+	msg.Dial.Peer.Id = []byte(pi.ID)
+	msg.Dial.Peer.Addrs = make([][]byte, len(pi.Addrs))
+	for i, addr := range pi.Addrs {
+		msg.Dial.Peer.Addrs[i] = addr.Bytes()
+	}
+
+	return msg
+}