1// Copyright 2009 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows
6
7package net
8
9import (
10	"context"
11	"syscall"
12)
13
14func sockaddrToUDP(sa syscall.Sockaddr) Addr {
15	switch sa := sa.(type) {
16	case *syscall.SockaddrInet4:
17		return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
18	case *syscall.SockaddrInet6:
19		return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneCache.name(int(sa.ZoneId))}
20	}
21	return nil
22}
23
24func (a *UDPAddr) family() int {
25	if a == nil || len(a.IP) <= IPv4len {
26		return syscall.AF_INET
27	}
28	if a.IP.To4() != nil {
29		return syscall.AF_INET
30	}
31	return syscall.AF_INET6
32}
33
34func (a *UDPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
35	if a == nil {
36		return nil, nil
37	}
38	return ipToSockaddr(family, a.IP, a.Port, a.Zone)
39}
40
41func (a *UDPAddr) toLocal(net string) sockaddr {
42	return &UDPAddr{loopbackIP(net), a.Port, a.Zone}
43}
44
45func (c *UDPConn) readFrom(b []byte) (int, *UDPAddr, error) {
46	var addr *UDPAddr
47	n, sa, err := c.fd.readFrom(b)
48	switch sa := sa.(type) {
49	case *syscall.SockaddrInet4:
50		addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
51	case *syscall.SockaddrInet6:
52		addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneCache.name(int(sa.ZoneId))}
53	}
54	return n, addr, err
55}
56
57func (c *UDPConn) readMsg(b, oob []byte) (n, oobn, flags int, addr *UDPAddr, err error) {
58	var sa syscall.Sockaddr
59	n, oobn, flags, sa, err = c.fd.readMsg(b, oob)
60	switch sa := sa.(type) {
61	case *syscall.SockaddrInet4:
62		addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
63	case *syscall.SockaddrInet6:
64		addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneCache.name(int(sa.ZoneId))}
65	}
66	return
67}
68
69func (c *UDPConn) writeTo(b []byte, addr *UDPAddr) (int, error) {
70	if c.fd.isConnected {
71		return 0, ErrWriteToConnected
72	}
73	if addr == nil {
74		return 0, errMissingAddress
75	}
76	sa, err := addr.sockaddr(c.fd.family)
77	if err != nil {
78		return 0, err
79	}
80	return c.fd.writeTo(b, sa)
81}
82
83func (c *UDPConn) writeMsg(b, oob []byte, addr *UDPAddr) (n, oobn int, err error) {
84	if c.fd.isConnected && addr != nil {
85		return 0, 0, ErrWriteToConnected
86	}
87	if !c.fd.isConnected && addr == nil {
88		return 0, 0, errMissingAddress
89	}
90	sa, err := addr.sockaddr(c.fd.family)
91	if err != nil {
92		return 0, 0, err
93	}
94	return c.fd.writeMsg(b, oob, sa)
95}
96
97func dialUDP(ctx context.Context, net string, laddr, raddr *UDPAddr) (*UDPConn, error) {
98	fd, err := internetSocket(ctx, net, laddr, raddr, syscall.SOCK_DGRAM, 0, "dial")
99	if err != nil {
100		return nil, err
101	}
102	return newUDPConn(fd), nil
103}
104
105func listenUDP(ctx context.Context, network string, laddr *UDPAddr) (*UDPConn, error) {
106	fd, err := internetSocket(ctx, network, laddr, nil, syscall.SOCK_DGRAM, 0, "listen")
107	if err != nil {
108		return nil, err
109	}
110	return newUDPConn(fd), nil
111}
112
113func listenMulticastUDP(ctx context.Context, network string, ifi *Interface, gaddr *UDPAddr) (*UDPConn, error) {
114	fd, err := internetSocket(ctx, network, gaddr, nil, syscall.SOCK_DGRAM, 0, "listen")
115	if err != nil {
116		return nil, err
117	}
118	c := newUDPConn(fd)
119	if ip4 := gaddr.IP.To4(); ip4 != nil {
120		if err := listenIPv4MulticastUDP(c, ifi, ip4); err != nil {
121			c.Close()
122			return nil, err
123		}
124	} else {
125		if err := listenIPv6MulticastUDP(c, ifi, gaddr.IP); err != nil {
126			c.Close()
127			return nil, err
128		}
129	}
130	return c, nil
131}
132
133func listenIPv4MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
134	if ifi != nil {
135		if err := setIPv4MulticastInterface(c.fd, ifi); err != nil {
136			return err
137		}
138	}
139	if err := setIPv4MulticastLoopback(c.fd, false); err != nil {
140		return err
141	}
142	if err := joinIPv4Group(c.fd, ifi, ip); err != nil {
143		return err
144	}
145	return nil
146}
147
148func listenIPv6MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
149	if ifi != nil {
150		if err := setIPv6MulticastInterface(c.fd, ifi); err != nil {
151			return err
152		}
153	}
154	if err := setIPv6MulticastLoopback(c.fd, false); err != nil {
155		return err
156	}
157	if err := joinIPv6Group(c.fd, ifi, ip); err != nil {
158		return err
159	}
160	return nil
161}
162