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
235
236
237
238
239
240
|
package network
import (
"bufio"
"encoding/json"
"fmt"
"log/slog"
"math/rand"
"net"
"sync"
"time"
"go.uber.org/zap"
)
var logger *zap.Logger
// PeerInfo represents a peer's ID and IP.
type PeerInfo struct {
ID string `json:"id"`
IP string `json:"ip"`
Port int `json:"port"`
}
// Message represents a structured message.
type Message struct {
Type string `json:"type"`
Payload []byte `json:"payload"`
Source PeerInfo `json:"source"`
Target PeerInfo `json:"target"`
Timestamp int64 `json:"timestamp"`
}
type NetworkCallback func(msg Message)
// TCPNetwork represents a full-duplex TCP peer.
type TCPNetwork struct {
localPeer PeerInfo
connections map[string]net.Conn
listener net.Listener
callbacks map[string]NetworkCallback
callbacksMu sync.RWMutex
isConnected bool
retryDelay time.Duration
sync.Mutex
}
// initializes a TCP peer
func NewTCPNetwork(localID, localIP string, localPort int) *TCPNetwork {
n := &TCPNetwork{
localPeer: PeerInfo{ID: localID, IP: localIP, Port: localPort},
connections: make(map[string]net.Conn),
callbacks: make(map[string]NetworkCallback),
isConnected: false,
retryDelay: 2 * time.Second,
}
go n.startServer()
logger, _ = zap.NewProduction()
return n
}
// Add a new peer connection to the local peer
func (n *TCPNetwork) AddPeer(remoteID string, remoteIP string, remotePort int) {
go n.retryConnect(remoteID, remoteIP, remotePort)
}
// startServer starts a TCP server to accept connections.
func (n *TCPNetwork) startServer() {
address := fmt.Sprintf("%s:%d", n.localPeer.IP, n.localPeer.Port)
listener, err := net.Listen("tcp", address)
if err != nil {
logger.Sugar().Errorf("failed to start server: %v", err)
}
n.listener = listener
logger.Sugar().Infof("server started on %s\n", address)
for {
conn, err := listener.Accept()
if err != nil {
logger.Sugar().Errorf("failed to accept connection: %v\n", err)
continue
}
remoteAddr := conn.RemoteAddr().String()
n.Lock()
n.connections[remoteAddr] = conn
n.Unlock()
n.isConnected = true
n.retryDelay = 2 * time.Second
logger.Sugar().Infof("connected to remote peer %s\n", remoteAddr)
go n.listenForMessages(conn)
}
}
// retryConnect attempts to connect to a remote peer.
func (n *TCPNetwork) retryConnect(remoteID, remoteIP string, remotePort int) {
for {
n.Lock()
_, exists := n.connections[remoteID]
n.Unlock()
if exists {
time.Sleep(5 * time.Second)
continue
}
address := fmt.Sprintf("%s:%d", remoteIP, remotePort)
conn, err := net.Dial("tcp", address)
if err != nil {
logger.Sugar().Errorf("failed to connect to %s: %v. Retrying in %v...", remoteID, err, n.retryDelay)
time.Sleep(n.retryDelay)
if n.retryDelay < 30*time.Second {
n.retryDelay *= 2
}
continue
}
n.Lock()
n.connections[remoteID] = conn
n.Unlock()
logger.Sugar().Infof("successfully connected to peer %s!", remoteID)
go n.listenForMessages(conn)
}
}
// Send sends a message to a specified remote peer.
func (n *TCPNetwork) Send(remoteID, messageType string, payload []byte) error {
n.Lock()
conn, exists := n.connections[remoteID]
n.Unlock()
if !exists {
return fmt.Errorf("not connected to peer %s", remoteID)
}
msg := Message{
Type: messageType,
Payload: payload,
Source: n.localPeer,
Target: PeerInfo{ID: remoteID},
Timestamp: time.Now().Unix(),
}
data, err := json.Marshal(msg)
if err != nil {
return fmt.Errorf("failed to marshal message: %v", err)
}
_, err = conn.Write(append(data, '\n'))
if err != nil {
logger.Sugar().Errorf("failed to send message to %s: %v. Reconnecting...", remoteID, err)
n.Lock()
delete(n.connections, remoteID)
n.Unlock()
go n.retryConnect(remoteID, "", 0)
return fmt.Errorf("failed to send message: %v", err)
}
return nil
}
// RegisterHandler registers a callback for a message type.
func (n *TCPNetwork) RegisterHandler(messageType string, callback NetworkCallback) {
n.callbacksMu.Lock()
n.callbacks[messageType] = callback
n.callbacksMu.Unlock()
}
// listenForMessages listens for incoming messages.
func (n *TCPNetwork) listenForMessages(conn net.Conn) {
reader := bufio.NewReader(conn)
for {
data, err := reader.ReadBytes('\n')
if err != nil {
logger.Debug("connection lost. Reconnecting...")
n.Lock()
for id, c := range n.connections {
if c == conn {
delete(n.connections, id)
go n.retryConnect(id, "", 0)
break
}
}
n.Unlock()
return
}
var message Message
if err := json.Unmarshal(data, &message); err != nil {
logger.Sugar().Errorf("failed to unmarshal message: %v\n", err)
continue
}
n.callbacksMu.RLock()
callback, exists := n.callbacks[message.Type]
n.callbacksMu.RUnlock()
if exists {
go callback(message)
}
}
}
func (n *TCPNetwork) IsConnected() bool {
n.Lock()
defer n.Unlock()
return n.isConnected
}
func GetOutboundIP() net.IP {
conn, err := net.Dial("udp", "8.8.8.8:80")
if err != nil {
slog.Error("err", err)
}
defer conn.Close()
localAddr := conn.LocalAddr().(*net.UDPAddr)
return localAddr.IP
}
func GetRandomAvailablePort() (int, error) {
for i := 0; i < 100; i += 1 {
port := rand.Intn(65535-1024) + 1024
addr := fmt.Sprintf(":%d", port)
ln, err := net.Listen("tcp", addr)
if err == nil {
defer ln.Close()
return port, nil
}
}
return 0, fmt.Errorf("failed to find an available port after multiple attempts")
}
|
