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.
5 // +build aix darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows
16 // A sockaddr represents a TCP, UDP, IP or Unix network endpoint
17 // address that can be converted into a syscall.Sockaddr.
18 type sockaddr
interface {
21 // family returns the platform-dependent address family
25 // isWildcard reports whether the address is a wildcard
29 // sockaddr returns the address converted into a syscall
30 // sockaddr type that implements syscall.Sockaddr
31 // interface. It returns a nil interface when the address is
33 sockaddr(family
int) (syscall
.Sockaddr
, error
)
35 // toLocal maps the zero address to a local system address (127.0.0.1 or ::1)
36 toLocal(net
string) sockaddr
39 // socket returns a network file descriptor that is ready for
40 // asynchronous I/O using the network poller.
41 func socket(ctx context
.Context
, net
string, family
, sotype
, proto
int, ipv6only
bool, laddr
, raddr sockaddr
) (fd
*netFD
, err error
) {
42 s
, err
:= sysSocket(family
, sotype
, proto
)
46 if err
= setDefaultSockopts(s
, family
, sotype
, ipv6only
); err
!= nil {
50 if fd
, err
= newFD(s
, family
, sotype
, net
); err
!= nil {
55 // This function makes a network file descriptor for the
56 // following applications:
58 // - An endpoint holder that opens a passive stream
59 // connection, known as a stream listener
61 // - An endpoint holder that opens a destination-unspecific
62 // datagram connection, known as a datagram listener
64 // - An endpoint holder that opens an active stream or a
65 // destination-specific datagram connection, known as a
68 // - An endpoint holder that opens the other connection, such
69 // as talking to the protocol stack inside the kernel
71 // For stream and datagram listeners, they will only require
72 // named sockets, so we can assume that it's just a request
73 // from stream or datagram listeners when laddr is not nil but
74 // raddr is nil. Otherwise we assume it's just for dialers or
75 // the other connection holders.
77 if laddr
!= nil && raddr
== nil {
79 case syscall
.SOCK_STREAM
, syscall
.SOCK_SEQPACKET
:
80 if err
:= fd
.listenStream(laddr
, listenerBacklog
); err
!= nil {
85 case syscall
.SOCK_DGRAM
:
86 if err
:= fd
.listenDatagram(laddr
); err
!= nil {
93 if err
:= fd
.dial(ctx
, laddr
, raddr
); err
!= nil {
100 func (fd
*netFD
) addrFunc() func(syscall
.Sockaddr
) Addr
{
102 case syscall
.AF_INET
, syscall
.AF_INET6
:
104 case syscall
.SOCK_STREAM
:
106 case syscall
.SOCK_DGRAM
:
108 case syscall
.SOCK_RAW
:
111 case syscall
.AF_UNIX
:
113 case syscall
.SOCK_STREAM
:
114 return sockaddrToUnix
115 case syscall
.SOCK_DGRAM
:
116 return sockaddrToUnixgram
117 case syscall
.SOCK_SEQPACKET
:
118 return sockaddrToUnixpacket
121 return func(syscall
.Sockaddr
) Addr
{ return nil }
124 func (fd
*netFD
) dial(ctx context
.Context
, laddr
, raddr sockaddr
) error
{
126 var lsa syscall
.Sockaddr
128 if lsa
, err
= laddr
.sockaddr(fd
.family
); err
!= nil {
130 } else if lsa
!= nil {
131 if err
:= syscall
.Bind(fd
.pfd
.Sysfd
, lsa
); err
!= nil {
132 return os
.NewSyscallError("bind", err
)
136 var rsa syscall
.Sockaddr
// remote address from the user
137 var crsa syscall
.Sockaddr
// remote address we actually connected to
139 if rsa
, err
= raddr
.sockaddr(fd
.family
); err
!= nil {
142 if crsa
, err
= fd
.connect(ctx
, lsa
, rsa
); err
!= nil {
145 fd
.isConnected
= true
147 if err
:= fd
.init(); err
!= nil {
151 // Record the local and remote addresses from the actual socket.
152 // Get the local address by calling Getsockname.
153 // For the remote address, use
154 // 1) the one returned by the connect method, if any; or
155 // 2) the one from Getpeername, if it succeeds; or
156 // 3) the one passed to us as the raddr parameter.
157 lsa
, _
= syscall
.Getsockname(fd
.pfd
.Sysfd
)
159 fd
.setAddr(fd
.addrFunc()(lsa
), fd
.addrFunc()(crsa
))
160 } else if rsa
, _
= syscall
.Getpeername(fd
.pfd
.Sysfd
); rsa
!= nil {
161 fd
.setAddr(fd
.addrFunc()(lsa
), fd
.addrFunc()(rsa
))
163 fd
.setAddr(fd
.addrFunc()(lsa
), raddr
)
168 func (fd
*netFD
) listenStream(laddr sockaddr
, backlog
int) error
{
169 if err
:= setDefaultListenerSockopts(fd
.pfd
.Sysfd
); err
!= nil {
172 if lsa
, err
:= laddr
.sockaddr(fd
.family
); err
!= nil {
174 } else if lsa
!= nil {
175 if err
:= syscall
.Bind(fd
.pfd
.Sysfd
, lsa
); err
!= nil {
176 return os
.NewSyscallError("bind", err
)
179 if err
:= listenFunc(fd
.pfd
.Sysfd
, backlog
); err
!= nil {
180 return os
.NewSyscallError("listen", err
)
182 if err
:= fd
.init(); err
!= nil {
185 lsa
, err
:= syscall
.Getsockname(fd
.pfd
.Sysfd
)
187 return os
.NewSyscallError("getsockname", err
)
189 fd
.setAddr(fd
.addrFunc()(lsa
), nil)
193 func (fd
*netFD
) listenDatagram(laddr sockaddr
) error
{
194 switch addr
:= laddr
.(type) {
196 // We provide a socket that listens to a wildcard
197 // address with reusable UDP port when the given laddr
198 // is an appropriate UDP multicast address prefix.
199 // This makes it possible for a single UDP listener to
200 // join multiple different group addresses, for
201 // multiple UDP listeners that listen on the same UDP
202 // port to join the same group address.
203 if addr
.IP
!= nil && addr
.IP
.IsMulticast() {
204 if err
:= setDefaultMulticastSockopts(fd
.pfd
.Sysfd
); err
!= nil {
209 case syscall
.AF_INET
:
211 case syscall
.AF_INET6
:
212 addr
.IP
= IPv6unspecified
217 if lsa
, err
:= laddr
.sockaddr(fd
.family
); err
!= nil {
219 } else if lsa
!= nil {
220 if err
:= syscall
.Bind(fd
.pfd
.Sysfd
, lsa
); err
!= nil {
221 return os
.NewSyscallError("bind", err
)
224 if err
:= fd
.init(); err
!= nil {
227 lsa
, err
:= syscall
.Getsockname(fd
.pfd
.Sysfd
)
229 return os
.NewSyscallError("getsockname", err
)
231 fd
.setAddr(fd
.addrFunc()(lsa
), nil)