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
|
// Copyright (c) 2025, Přemysl Eric Janouch <p@janouch.name>
// SPDX-License-Identifier: 0BSD
package main
import (
"encoding/binary"
"encoding/json"
"errors"
"flag"
"fmt"
"io"
"log"
"net"
"os"
"time"
)
var (
debug = flag.Bool("debug", false, "enable debug output")
version = flag.Bool("version", false, "show version and exit")
projectName = "xR"
projectVersion = "?"
)
func now() string {
return time.Now().UTC().Format(time.RFC3339Nano)
}
func relayReadFrame(r io.Reader) bool {
var length uint32
if err := binary.Read(
r, binary.BigEndian, &length); errors.Is(err, io.EOF) {
return false
} else if err != nil {
log.Fatalln("Event receive failed: " + err.Error())
}
b := make([]byte, length)
if _, err := io.ReadFull(r, b); errors.Is(err, io.EOF) {
return false
} else if err != nil {
log.Fatalln("Event receive failed: " + err.Error())
}
m := struct {
When string `json:"when"`
Binary []byte `json:"raw"`
RelayEventMessage
}{
When: now(),
Binary: b,
}
if after, ok := m.RelayEventMessage.ConsumeFrom(b); !ok {
log.Println("Event deserialization failed")
} else if len(after) != 0 {
log.Println("Event deserialization failed: trailing data")
return true
}
j, err := json.Marshal(m)
if err != nil {
log.Fatalln("Event marshalling failed: " + err.Error())
}
fmt.Printf("%s\n", j)
return true
}
func run(addressConnect string) {
conn, err := net.Dial("tcp", addressConnect)
if err != nil {
log.Println("Connection failed: " + err.Error())
return
}
defer conn.Close()
// We can only support this one protocol version
// that proto.go has been generated for.
m := RelayCommandMessage{CommandSeq: 0, Data: RelayCommandData{
Variant: &RelayCommandDataHello{Version: RelayVersion},
}}
b, ok := m.AppendTo(make([]byte, 4))
if !ok {
log.Fatalln("Command serialization failed")
}
binary.BigEndian.PutUint32(b[:4], uint32(len(b)-4))
if _, err := conn.Write(b); err != nil {
log.Fatalln("Command send failed: " + err.Error())
}
// You can differentiate the direction by the presence
// of .data.command or .data.event.
if *debug {
j, err := json.Marshal(struct {
When string `json:"when"`
Binary []byte `json:"raw"`
RelayCommandMessage
}{
When: now(),
Binary: b,
RelayCommandMessage: m,
})
if err != nil {
log.Fatalln("Command marshalling failed: " + err.Error())
}
fmt.Printf("%s\n", j)
}
for relayReadFrame(conn) {
}
}
func main() {
flag.Usage = func() {
fmt.Fprintf(flag.CommandLine.Output(),
"Usage: %s [OPTION...] CONNECT\n\n", os.Args[0])
flag.PrintDefaults()
}
flag.Parse()
if *version {
fmt.Printf("%s %s (relay protocol version %d)\n",
projectName, projectVersion, RelayVersion)
return
}
if flag.NArg() != 1 {
flag.Usage()
os.Exit(1)
}
// TODO(p): This program should be able to run as a filter as well.
run(flag.Arg(0))
}
|
