code review 3136042: net: add ReadFrom and WriteTo windows version.

src/pkg/syscall/syscall_windows.go

 // 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.
 
 // Windows system calls.
 
 package syscall
 
 import (
         "unsafe"
@@ skipping 449 matching lines @@
 //sys   bind(s int32, name uintptr, namelen int32) (errno int) [failretval=-1] = wsock32.bind
 //sys   connect(s int32, name uintptr, namelen int32) (errno int) [failretval=-1] = wsock32.connect
 //sys   getsockname(s int32, rsa *RawSockaddrAny, addrlen *int32) (errno int) [failretval=-1] = wsock32.getsockname
 //sys   getpeername(s int32, rsa *RawSockaddrAny, addrlen *int32) (errno int) [failretval=-1] = wsock32.getpeername
 //sys   listen(s int32, backlog int32) (errno int) [failretval=-1] = wsock32.listen
 //sys   shutdown(s int32, how int32) (errno int) [failretval=-1] = wsock32.shutdown
 //sys   AcceptEx(ls uint32, as uint32, buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, recvd *uint32, overlapped *Overlapped) (ok bool, errno int) = wsock32.AcceptEx
 //sys   GetAcceptExSockaddrs(buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, lrsa **RawSockaddrAny, lrsalen *int32, rrsa **RawSockaddrAny, rrsalen *int32) = wsock32.GetAcceptExSockaddrs
 //sys   WSARecv(s uint32, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32, overlapped *Overlapped, croutine *byte) (errno int) [failretval=-1] = ws2_32.WSARecv
 //sys   WSASend(s uint32, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, overlapped *Overlapped, croutine *byte) (errno int) [failretval=-1] = ws2_32.WSASend
+//sys   WSARecvFrom(s uint32, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32,  from *RawSockaddrAny, fromlen *int32, overlapped *Overlapped, croutine *byte) (errno int) [failretval=-1] = ws2_32.WSARecvFrom
+//sys   _WSASendTo(s uint32, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *RawSockaddrAny, tolen int32,  overlapped *Overlapped, croutine *byte) (errno int) [failretval=-1] = ws2_32.WSASendTo

[brainman, 2010/11/19 05:22:00]

Please, do not rename API function name if possible, let's call it WSASendTo
(not _WSASendTo).

[vcc, 2010/11/20 03:14:58]

Done.

 //sys   GetHostByName(name string) (h *Hostent, errno int) [failretval=nil] = ws2_32.gethostbyname
 //sys   GetServByName(name string, proto string) (s *Servent, errno int) [failretval=nil] = ws2_32.getservbyname
 //sys   Ntohs(netshort uint16) (u uint16) = ws2_32.ntohs
 //sys   DnsQuery(name string, qtype uint16, options uint32, extra *byte, qrs **DNSRecord, pr *byte) (status uint32) = dnsapi.DnsQuery_W
 //sys   DnsRecordListFree(rl *DNSRecord, freetype uint32) = dnsapi.DnsRecordListFree
 
 // For testing: clients can set this flag to force
 // creation of IPv6 sockets to return EAFNOSUPPORT.
 var SocketDisableIPv6 bool
 
@@ skipping 146 matching lines @@
 func GetAcceptIOCPSockaddrs(attrs *byte) (lsa, rsa Sockaddr) {
         var lrsa, rrsa *RawSockaddrAny
         var llen, rlen int32
         alen := uint32(unsafe.Sizeof(*lrsa))
         GetAcceptExSockaddrs(attrs, 0, alen, alen, &lrsa, &llen, &rrsa, &rlen)
         lsa, _ = lrsa.Sockaddr()
         rsa, _ = rrsa.Sockaddr()
         return
 }
 
+func WSASendTo(s uint32, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to Sockaddr, overlapped *Overlapped, croutine *byte) (errno int) {

[brainman, 2010/11/19 05:22:00]

You would have to rename this into something else. I suggest Sendto() for now.

[vcc, 2010/11/20 03:14:58]

Already has Sendto, 
func Sendto(fd int, p []byte, flags int, to Sockaddr) (errno int)            {
return EWINDOWS }

rename it to WSASendto.

+        rsa, l, _ := to.sockaddr()

[brainman, 2010/11/19 05:22:00]

Should check for errors. See Bind() or Connect() for example.

[vcc, 2010/11/20 03:14:58]

Done.

+        errno = _WSASendTo(s, bufs, bufcnt, sent, flags, (*RawSockaddrAny)(unsafe.Pointer(rsa)), l, overlapped, croutine)
+        return
+}
+
 // TODO(brainman): fix all needed for net
 
 func Accept(fd int) (nfd int, sa Sockaddr, errno int)                        { return 0, nil, EWINDOWS }
 func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, errno int) { return 0, nil, EWINDOWS }
 func Sendto(fd int, p []byte, flags int, to Sockaddr) (errno int)            { return EWINDOWS }
 func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (errno int)          { return EWINDOWS }
 
 type Linger struct {
         Onoff  int32
         Linger int32
@@ skipping 102 matching lines @@
 
 func (WaitStatus) Stopped() bool { return false }
 
 func (WaitStatus) Continued() bool { return false }
 
 func (WaitStatus) StopSignal() int { return -1 }
 
 func (w WaitStatus) Signaled() bool { return w.Status == WAIT_OBJECT_0 }
 
 func (WaitStatus) TrapCause() int { return -1 }