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
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
|
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build darwin dragonfly freebsd linux netbsd openbsd windows
package net
import (
"syscall"
"time"
)
func sockaddrToUDP(sa syscall.Sockaddr) Addr {
switch sa := sa.(type) {
case *syscall.SockaddrInet4:
return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
case *syscall.SockaddrInet6:
return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
}
return nil
}
func (a *UDPAddr) family() int {
if a == nil || len(a.IP) <= IPv4len {
return syscall.AF_INET
}
if a.IP.To4() != nil {
return syscall.AF_INET
}
return syscall.AF_INET6
}
func (a *UDPAddr) isWildcard() bool {
if a == nil || a.IP == nil {
return true
}
return a.IP.IsUnspecified()
}
func (a *UDPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
if a == nil {
return nil, nil
}
return ipToSockaddr(family, a.IP, a.Port, a.Zone)
}
// UDPConn is the implementation of the Conn and PacketConn interfaces
// for UDP network connections.
type UDPConn struct {
conn
}
func newUDPConn(fd *netFD) *UDPConn { return &UDPConn{conn{fd}} }
// ReadFromUDP reads a UDP packet from c, copying the payload into b.
// It returns the number of bytes copied into b and the return address
// that was on the packet.
//
// ReadFromUDP can be made to time out and return an error with
// Timeout() == true after a fixed time limit; see SetDeadline and
// SetReadDeadline.
func (c *UDPConn) ReadFromUDP(b []byte) (n int, addr *UDPAddr, err error) {
if !c.ok() {
return 0, nil, syscall.EINVAL
}
n, sa, err := c.fd.ReadFrom(b)
switch sa := sa.(type) {
case *syscall.SockaddrInet4:
addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
case *syscall.SockaddrInet6:
addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
}
return
}
// ReadFrom implements the PacketConn ReadFrom method.
func (c *UDPConn) ReadFrom(b []byte) (int, Addr, error) {
if !c.ok() {
return 0, nil, syscall.EINVAL
}
n, addr, err := c.ReadFromUDP(b)
return n, addr.toAddr(), err
}
// ReadMsgUDP reads a packet from c, copying the payload into b and
// the associated out-of-band data into oob. It returns the number
// of bytes copied into b, the number of bytes copied into oob, the
// flags that were set on the packet and the source address of the
// packet.
func (c *UDPConn) ReadMsgUDP(b, oob []byte) (n, oobn, flags int, addr *UDPAddr, err error) {
if !c.ok() {
return 0, 0, 0, nil, syscall.EINVAL
}
var sa syscall.Sockaddr
n, oobn, flags, sa, err = c.fd.ReadMsg(b, oob)
switch sa := sa.(type) {
case *syscall.SockaddrInet4:
addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
case *syscall.SockaddrInet6:
addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
}
return
}
// WriteToUDP writes a UDP packet to addr via c, copying the payload
// from b.
//
// WriteToUDP can be made to time out and return an error with
// Timeout() == true after a fixed time limit; see SetDeadline and
// SetWriteDeadline. On packet-oriented connections, write timeouts
// are rare.
func (c *UDPConn) WriteToUDP(b []byte, addr *UDPAddr) (int, error) {
if !c.ok() {
return 0, syscall.EINVAL
}
if c.fd.isConnected {
return 0, &OpError{"write", c.fd.net, addr, ErrWriteToConnected}
}
if addr == nil {
return 0, &OpError{Op: "write", Net: c.fd.net, Addr: nil, Err: errMissingAddress}
}
sa, err := addr.sockaddr(c.fd.family)
if err != nil {
return 0, &OpError{"write", c.fd.net, addr, err}
}
return c.fd.WriteTo(b, sa)
}
// WriteTo implements the PacketConn WriteTo method.
func (c *UDPConn) WriteTo(b []byte, addr Addr) (int, error) {
if !c.ok() {
return 0, syscall.EINVAL
}
a, ok := addr.(*UDPAddr)
if !ok {
return 0, &OpError{"write", c.fd.net, addr, syscall.EINVAL}
}
return c.WriteToUDP(b, a)
}
// WriteMsgUDP writes a packet to addr via c, copying the payload from
// b and the associated out-of-band data from oob. It returns the
// number of payload and out-of-band bytes written.
func (c *UDPConn) WriteMsgUDP(b, oob []byte, addr *UDPAddr) (n, oobn int, err error) {
if !c.ok() {
return 0, 0, syscall.EINVAL
}
if c.fd.isConnected {
return 0, 0, &OpError{"write", c.fd.net, addr, ErrWriteToConnected}
}
if addr == nil {
return 0, 0, &OpError{Op: "write", Net: c.fd.net, Addr: nil, Err: errMissingAddress}
}
sa, err := addr.sockaddr(c.fd.family)
if err != nil {
return 0, 0, &OpError{"write", c.fd.net, addr, err}
}
return c.fd.WriteMsg(b, oob, sa)
}
// DialUDP connects to the remote address raddr on the network net,
// which must be "udp", "udp4", or "udp6". If laddr is not nil, it is
// used as the local address for the connection.
func DialUDP(net string, laddr, raddr *UDPAddr) (*UDPConn, error) {
switch net {
case "udp", "udp4", "udp6":
default:
return nil, &OpError{Op: "dial", Net: net, Addr: raddr, Err: UnknownNetworkError(net)}
}
if raddr == nil {
return nil, &OpError{Op: "dial", Net: net, Addr: nil, Err: errMissingAddress}
}
return dialUDP(net, laddr, raddr, noDeadline)
}
func dialUDP(net string, laddr, raddr *UDPAddr, deadline time.Time) (*UDPConn, error) {
fd, err := internetSocket(net, laddr, raddr, deadline, syscall.SOCK_DGRAM, 0, "dial", sockaddrToUDP)
if err != nil {
return nil, &OpError{Op: "dial", Net: net, Addr: raddr, Err: err}
}
return newUDPConn(fd), nil
}
// ListenUDP listens for incoming UDP packets addressed to the local
// address laddr. Net must be "udp", "udp4", or "udp6". If laddr has
// a port of 0, ListenUDP will choose an available port.
// The LocalAddr method of the returned UDPConn can be used to
// discover the port. The returned connection's ReadFrom and WriteTo
// methods can be used to receive and send UDP packets with per-packet
// addressing.
func ListenUDP(net string, laddr *UDPAddr) (*UDPConn, error) {
switch net {
case "udp", "udp4", "udp6":
default:
return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: UnknownNetworkError(net)}
}
if laddr == nil {
laddr = &UDPAddr{}
}
fd, err := internetSocket(net, laddr, nil, noDeadline, syscall.SOCK_DGRAM, 0, "listen", sockaddrToUDP)
if err != nil {
return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: err}
}
return newUDPConn(fd), nil
}
// ListenMulticastUDP listens for incoming multicast UDP packets
// addressed to the group address gaddr on ifi, which specifies the
// interface to join. ListenMulticastUDP uses default multicast
// interface if ifi is nil.
func ListenMulticastUDP(net string, ifi *Interface, gaddr *UDPAddr) (*UDPConn, error) {
switch net {
case "udp", "udp4", "udp6":
default:
return nil, &OpError{Op: "listen", Net: net, Addr: gaddr, Err: UnknownNetworkError(net)}
}
if gaddr == nil || gaddr.IP == nil {
return nil, &OpError{Op: "listen", Net: net, Addr: nil, Err: errMissingAddress}
}
fd, err := internetSocket(net, gaddr, nil, noDeadline, syscall.SOCK_DGRAM, 0, "listen", sockaddrToUDP)
if err != nil {
return nil, &OpError{Op: "listen", Net: net, Addr: gaddr, Err: err}
}
c := newUDPConn(fd)
if ip4 := gaddr.IP.To4(); ip4 != nil {
if err := listenIPv4MulticastUDP(c, ifi, ip4); err != nil {
c.Close()
return nil, &OpError{Op: "listen", Net: net, Addr: &IPAddr{IP: ip4}, Err: err}
}
} else {
if err := listenIPv6MulticastUDP(c, ifi, gaddr.IP); err != nil {
c.Close()
return nil, &OpError{Op: "listen", Net: net, Addr: &IPAddr{IP: gaddr.IP}, Err: err}
}
}
return c, nil
}
func listenIPv4MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
if ifi != nil {
if err := setIPv4MulticastInterface(c.fd, ifi); err != nil {
return err
}
}
if err := setIPv4MulticastLoopback(c.fd, false); err != nil {
return err
}
if err := joinIPv4Group(c.fd, ifi, ip); err != nil {
return err
}
return nil
}
func listenIPv6MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
if ifi != nil {
if err := setIPv6MulticastInterface(c.fd, ifi); err != nil {
return err
}
}
if err := setIPv6MulticastLoopback(c.fd, false); err != nil {
return err
}
if err := joinIPv6Group(c.fd, ifi, ip); err != nil {
return err
}
return nil
}
|
