forked from tbrandon/mbserver
/
servetcp.go
65 lines (60 loc) · 1.6 KB
/
servetcp.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
package mbserver
import (
"io"
"log"
"net"
"strings"
)
func (s *Server) accept(listen net.Listener) error {
for {
conn, err := listen.Accept()
if err != nil {
if strings.Contains(err.Error(), "use of closed network connection") {
return nil
}
log.Printf("Unable to accept connections: %#v\n", err)
return err
}
go func(conn net.Conn) {
log.Printf("connected: %v<->%v\n", conn.LocalAddr(), conn.RemoteAddr())
packet_count := 0
packet := make([]byte, 512)
defer func() {
conn.Close()
log.Printf("closed: %v<->%v,packet_count:%d\n", conn.LocalAddr(), conn.RemoteAddr(), packet_count)
}()
for {
bytesRead, err := conn.Read(packet)
if err != nil {
if err != io.EOF {
log.Printf("read error %v<->%v, %v\n", conn.LocalAddr(), conn.RemoteAddr(), err)
}
return
}
// log.Printf("packet %v,%d [% x]\n", conn.RemoteAddr(), bytesRead, packet[:bytesRead])
// Set the length of the packet to the number of read bytes.
frame, err := NewTCPFrame(packet[:bytesRead])
if err != nil {
log.Printf("bad packet error %v\n", err)
return
}
packet_count++
request := &Request{conn, frame}
// s.requestChan <- request
response := s.handle(request)
conn.Write(response.Bytes())
}
}(conn)
}
}
// ListenTCP starts the Modbus server listening on "address:port".
func (s *Server) ListenTCP(addressPort string) (err error) {
listen, err := net.Listen("tcp", addressPort)
if err != nil {
log.Printf("Failed to Listen: %v\n", err)
return err
}
s.listeners = append(s.listeners, listen)
go s.accept(listen)
return err
}