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
|
package server6
import (
"fmt"
"log"
"net"
"sync"
"time"
"github.com/insomniacslk/dhcp/dhcpv6"
)
// Handler is a type that defines the handler function to be called every time a
// valid DHCPv6 message is received
type Handler func(conn net.PacketConn, peer net.Addr, m dhcpv6.DHCPv6)
// Server represents a DHCPv6 server object
type Server struct {
conn net.PacketConn
connMutex sync.Mutex
shouldStop chan bool
Handler Handler
localAddr net.UDPAddr
}
// LocalAddr returns the local address of the listening socket, or nil if not
// listening
func (s *Server) LocalAddr() net.Addr {
s.connMutex.Lock()
defer s.connMutex.Unlock()
if s.conn == nil {
return nil
}
return s.conn.LocalAddr()
}
// ActivateAndServe starts the DHCPv6 server. The listener will run in
// background, and can be interrupted with `Server.Close`.
func (s *Server) ActivateAndServe() error {
s.connMutex.Lock()
if s.conn != nil {
// this may panic if s.conn is closed but not reset properly. For that
// you should use `Server.Close`.
s.Close()
}
conn, err := net.ListenUDP("udp6", &s.localAddr)
if err != nil {
s.connMutex.Unlock()
return err
}
s.conn = conn
s.connMutex.Unlock()
var (
pc *net.UDPConn
ok bool
)
if pc, ok = s.conn.(*net.UDPConn); !ok {
return fmt.Errorf("error: not an UDPConn")
}
if pc == nil {
return fmt.Errorf("ActivateAndServe: invalid nil PacketConn")
}
log.Printf("Server listening on %s", pc.LocalAddr())
log.Print("Ready to handle requests")
for {
select {
case <-s.shouldStop:
break
case <-time.After(time.Millisecond):
}
pc.SetReadDeadline(time.Now().Add(time.Second))
rbuf := make([]byte, 4096) // FIXME this is bad
n, peer, err := pc.ReadFrom(rbuf)
if err != nil {
switch err.(type) {
case net.Error:
if !err.(net.Error).Timeout() {
return err
}
// if timeout, silently skip and continue
default:
// complain and continue
log.Printf("Error reading from packet conn: %v", err)
}
continue
}
log.Printf("Handling request from %v", peer)
m, err := dhcpv6.FromBytes(rbuf[:n])
if err != nil {
log.Printf("Error parsing DHCPv6 request: %v", err)
continue
}
go s.Handler(pc, peer, m)
}
}
// Close sends a termination request to the server, and closes the UDP listener
func (s *Server) Close() error {
s.shouldStop <- true
s.connMutex.Lock()
defer s.connMutex.Unlock()
if s.conn != nil {
ret := s.conn.Close()
s.conn = nil
return ret
}
return nil
}
// NewServer initializes and returns a new Server object
func NewServer(addr net.UDPAddr, handler Handler) *Server {
return &Server{
localAddr: addr,
Handler: handler,
shouldStop: make(chan bool, 1),
}
}
|
