forked from libp2p/go-libp2p
-
Notifications
You must be signed in to change notification settings - Fork 0
/
chat.go
234 lines (196 loc) · 6.52 KB
/
chat.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
/*
*
* The MIT License (MIT)
*
* Copyright (c) 2014 Juan Batiz-Benet
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* This program demonstrate a simple chat application using p2p communication.
*
*/
package main
import (
"bufio"
"context"
"crypto/rand"
"flag"
"fmt"
"io"
"log"
mrand "math/rand"
"os"
"github.com/libp2p/go-libp2p"
"github.com/libp2p/go-libp2p/core/crypto"
"github.com/libp2p/go-libp2p/core/host"
"github.com/libp2p/go-libp2p/core/network"
"github.com/libp2p/go-libp2p/core/peer"
"github.com/libp2p/go-libp2p/core/peerstore"
"github.com/multiformats/go-multiaddr"
)
func handleStream(s network.Stream) {
log.Println("Got a new stream!")
// Create a buffer stream for non-blocking read and write.
rw := bufio.NewReadWriter(bufio.NewReader(s), bufio.NewWriter(s))
go readData(rw)
go writeData(rw)
// stream 's' will stay open until you close it (or the other side closes it).
}
func readData(rw *bufio.ReadWriter) {
for {
str, _ := rw.ReadString('\n')
if str == "" {
return
}
if str != "\n" {
// Green console colour: \x1b[32m
// Reset console colour: \x1b[0m
fmt.Printf("\x1b[32m%s\x1b[0m> ", str)
}
}
}
func writeData(rw *bufio.ReadWriter) {
stdReader := bufio.NewReader(os.Stdin)
for {
fmt.Print("> ")
sendData, err := stdReader.ReadString('\n')
if err != nil {
log.Println(err)
return
}
rw.WriteString(fmt.Sprintf("%s\n", sendData))
rw.Flush()
}
}
func main() {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
sourcePort := flag.Int("sp", 0, "Source port number")
dest := flag.String("d", "", "Destination multiaddr string")
help := flag.Bool("help", false, "Display help")
debug := flag.Bool("debug", false, "Debug generates the same node ID on every execution")
flag.Parse()
if *help {
fmt.Printf("This program demonstrates a simple p2p chat application using libp2p\n\n")
fmt.Println("Usage: Run './chat -sp <SOURCE_PORT>' where <SOURCE_PORT> can be any port number.")
fmt.Println("Now run './chat -d <MULTIADDR>' where <MULTIADDR> is multiaddress of previous listener host.")
os.Exit(0)
}
// If debug is enabled, use a constant random source to generate the peer ID. Only useful for debugging,
// off by default. Otherwise, it uses rand.Reader.
var r io.Reader
if *debug {
// Use the port number as the randomness source.
// This will always generate the same host ID on multiple executions, if the same port number is used.
// Never do this in production code.
r = mrand.New(mrand.NewSource(int64(*sourcePort)))
} else {
r = rand.Reader
}
h, err := makeHost(*sourcePort, r)
if err != nil {
log.Println(err)
return
}
if *dest == "" {
startPeer(ctx, h, handleStream)
} else {
rw, err := startPeerAndConnect(ctx, h, *dest)
if err != nil {
log.Println(err)
return
}
// Create a thread to read and write data.
go writeData(rw)
go readData(rw)
}
// Wait forever
select {}
}
func makeHost(port int, randomness io.Reader) (host.Host, error) {
// Creates a new RSA key pair for this host.
prvKey, _, err := crypto.GenerateKeyPairWithReader(crypto.RSA, 2048, randomness)
if err != nil {
log.Println(err)
return nil, err
}
// 0.0.0.0 will listen on any interface device.
sourceMultiAddr, _ := multiaddr.NewMultiaddr(fmt.Sprintf("/ip4/0.0.0.0/tcp/%d", port))
// libp2p.New constructs a new libp2p Host.
// Other options can be added here.
return libp2p.New(
libp2p.ListenAddrs(sourceMultiAddr),
libp2p.Identity(prvKey),
)
}
func startPeer(ctx context.Context, h host.Host, streamHandler network.StreamHandler) {
// Set a function as stream handler.
// This function is called when a peer connects, and starts a stream with this protocol.
// Only applies on the receiving side.
h.SetStreamHandler("/chat/1.0.0", streamHandler)
// Let's get the actual TCP port from our listen multiaddr, in case we're using 0 (default; random available port).
var port string
for _, la := range h.Network().ListenAddresses() {
if p, err := la.ValueForProtocol(multiaddr.P_TCP); err == nil {
port = p
break
}
}
if port == "" {
log.Println("was not able to find actual local port")
return
}
log.Printf("Run './chat -d /ip4/127.0.0.1/tcp/%v/p2p/%s' on another console.\n", port, h.ID())
log.Println("You can replace 127.0.0.1 with public IP as well.")
log.Println("Waiting for incoming connection")
log.Println()
}
func startPeerAndConnect(ctx context.Context, h host.Host, destination string) (*bufio.ReadWriter, error) {
log.Println("This node's multiaddresses:")
for _, la := range h.Addrs() {
log.Printf(" - %v\n", la)
}
log.Println()
// Turn the destination into a multiaddr.
maddr, err := multiaddr.NewMultiaddr(destination)
if err != nil {
log.Println(err)
return nil, err
}
// Extract the peer ID from the multiaddr.
info, err := peer.AddrInfoFromP2pAddr(maddr)
if err != nil {
log.Println(err)
return nil, err
}
// Add the destination's peer multiaddress in the peerstore.
// This will be used during connection and stream creation by libp2p.
h.Peerstore().AddAddrs(info.ID, info.Addrs, peerstore.PermanentAddrTTL)
// Start a stream with the destination.
// Multiaddress of the destination peer is fetched from the peerstore using 'peerId'.
s, err := h.NewStream(context.Background(), info.ID, "/chat/1.0.0")
if err != nil {
log.Println(err)
return nil, err
}
log.Println("Established connection to destination")
// Create a buffered stream so that read and writes are non-blocking.
rw := bufio.NewReadWriter(bufio.NewReader(s), bufio.NewWriter(s))
return rw, nil
}