1package dns
2
3import (
4	"net"
5)
6
7func setUDPSocketOptions(conn *net.UDPConn) error { return nil }
8
9// SessionUDP holds the remote address and the associated
10// out-of-band data.
11type SessionUDP struct {
12	raddr   *net.UDPAddr
13	context []byte
14}
15
16// RemoteAddr returns the remote network address.
17func (s *SessionUDP) RemoteAddr() net.Addr { return s.raddr }
18
19// ReadFromSessionUDP acts just like net.UDPConn.ReadFrom(), but returns a session object instead of a
20// net.UDPAddr.
21func ReadFromSessionUDP(conn *net.UDPConn, b []byte) (int, *SessionUDP, error) {
22	oob := make([]byte, 40)
23	n, oobn, _, raddr, err := conn.ReadMsgUDP(b, oob)
24	if err != nil {
25		return n, nil, err
26	}
27	return n, &SessionUDP{raddr, oob[:oobn]}, err
28}
29
30// WriteToSessionUDP acts just like net.UDPConn.WritetTo(), but uses a *SessionUDP instead of a net.Addr.
31func WriteToSessionUDP(conn *net.UDPConn, b []byte, session *SessionUDP) (int, error) {
32	n, _, err := conn.WriteMsgUDP(b, session.context, session.raddr)
33	return n, err
34}
35