Source file src/net/udpsock_posix.go
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6
7 package net
8
9 import (
10 "context"
11 "syscall"
12 )
13
14 func 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
24 func (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
34 func (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
41 func (a *UDPAddr) toLocal(net string) sockaddr {
42 return &UDPAddr{loopbackIP(net), a.Port, a.Zone}
43 }
44
45 func (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
57 func (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
69 func (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
83 func (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
97 func (sd *sysDialer) dialUDP(ctx context.Context, laddr, raddr *UDPAddr) (*UDPConn, error) {
98 fd, err := internetSocket(ctx, sd.network, laddr, raddr, syscall.SOCK_DGRAM, 0, "dial", sd.Dialer.Control)
99 if err != nil {
100 return nil, err
101 }
102 return newUDPConn(fd), nil
103 }
104
105 func (sl *sysListener) listenUDP(ctx context.Context, laddr *UDPAddr) (*UDPConn, error) {
106 fd, err := internetSocket(ctx, sl.network, laddr, nil, syscall.SOCK_DGRAM, 0, "listen", sl.ListenConfig.Control)
107 if err != nil {
108 return nil, err
109 }
110 return newUDPConn(fd), nil
111 }
112
113 func (sl *sysListener) listenMulticastUDP(ctx context.Context, ifi *Interface, gaddr *UDPAddr) (*UDPConn, error) {
114 fd, err := internetSocket(ctx, sl.network, gaddr, nil, syscall.SOCK_DGRAM, 0, "listen", sl.ListenConfig.Control)
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
133 func 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
148 func 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
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