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
|
package turn
import (
"fmt"
"net"
"github.com/pion/randutil"
"github.com/pion/transport/vnet"
)
// RelayAddressGeneratorPortRange can be used to only allocate connections inside a defined port range.
// Similar to the RelayAddressGeneratorStatic a static ip address can be set.
type RelayAddressGeneratorPortRange struct {
// RelayAddress is the IP returned to the user when the relay is created
RelayAddress net.IP
// MinPort the minimum port to allocate
MinPort uint16
// MaxPort the maximum (inclusive) port to allocate
MaxPort uint16
// MaxRetries the amount of tries to allocate a random port in the defined range
MaxRetries int
// Rand the random source of numbers
Rand randutil.MathRandomGenerator
// Address is passed to Listen/ListenPacket when creating the Relay
Address string
Net *vnet.Net
}
// Validate is called on server startup and confirms the RelayAddressGenerator is properly configured
func (r *RelayAddressGeneratorPortRange) Validate() error {
if r.Net == nil {
r.Net = vnet.NewNet(nil)
}
if r.Rand == nil {
r.Rand = randutil.NewMathRandomGenerator()
}
if r.MaxRetries == 0 {
r.MaxRetries = 10
}
switch {
case r.MinPort == 0:
return errMinPortNotZero
case r.MaxPort == 0:
return errMaxPortNotZero
case r.RelayAddress == nil:
return errRelayAddressInvalid
case r.Address == "":
return errListeningAddressInvalid
default:
return nil
}
}
// AllocatePacketConn generates a new PacketConn to receive traffic on and the IP/Port to populate the allocation response with
func (r *RelayAddressGeneratorPortRange) AllocatePacketConn(network string, requestedPort int) (net.PacketConn, net.Addr, error) {
if requestedPort != 0 {
conn, err := r.Net.ListenPacket(network, fmt.Sprintf("%s:%d", r.Address, requestedPort))
if err != nil {
return nil, nil, err
}
relayAddr := conn.LocalAddr().(*net.UDPAddr)
relayAddr.IP = r.RelayAddress
return conn, relayAddr, nil
}
for try := 0; try < r.MaxRetries; try++ {
port := r.MinPort + uint16(r.Rand.Intn(int((r.MaxPort+1)-r.MinPort)))
conn, err := r.Net.ListenPacket(network, fmt.Sprintf("%s:%d", r.Address, port))
if err != nil {
continue
}
relayAddr := conn.LocalAddr().(*net.UDPAddr)
relayAddr.IP = r.RelayAddress
return conn, relayAddr, nil
}
return nil, nil, errMaxRetriesExceeded
}
// AllocateConn generates a new Conn to receive traffic on and the IP/Port to populate the allocation response with
func (r *RelayAddressGeneratorPortRange) AllocateConn(network string, requestedPort int) (net.Conn, net.Addr, error) {
return nil, nil, errTODO
}
|
