From 4b45465282a4624cf39876842a017334f13b8aff Mon Sep 17 00:00:00 2001
From: Aman Gupta <aman@tmm1.net>
Date: Tue, 7 Nov 2017 22:02:11 -0800
Subject: [PATCH] windows: add WSA{Send,Recv}Msg

Change-Id: Id71df85e55e586b33fac66c5494291e11db8ed14
Reviewed-on: https://go-review.googlesource.com/76471
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
---
 windows/syscall_windows.go | 69 ++++++++++++++++++++++++++++++++++++++
 windows/types_windows.go   | 34 +++++++++++++++++++
 2 files changed, 103 insertions(+)

diff --git a/windows/syscall_windows.go b/windows/syscall_windows.go
index bb778dbd..f48fec60 100644
--- a/windows/syscall_windows.go
+++ b/windows/syscall_windows.go
@@ -796,6 +796,75 @@ func ConnectEx(fd Handle, sa Sockaddr, sendBuf *byte, sendDataLen uint32, bytesS
 	return connectEx(fd, ptr, n, sendBuf, sendDataLen, bytesSent, overlapped)
 }
 
+var sendRecvMsgFunc struct {
+	once     sync.Once
+	sendAddr uintptr
+	recvAddr uintptr
+	err      error
+}
+
+func loadWSASendRecvMsg() error {
+	sendRecvMsgFunc.once.Do(func() {
+		var s Handle
+		s, sendRecvMsgFunc.err = Socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)
+		if sendRecvMsgFunc.err != nil {
+			return
+		}
+		defer CloseHandle(s)
+		var n uint32
+		sendRecvMsgFunc.err = WSAIoctl(s,
+			SIO_GET_EXTENSION_FUNCTION_POINTER,
+			(*byte)(unsafe.Pointer(&WSAID_WSARECVMSG)),
+			uint32(unsafe.Sizeof(WSAID_WSARECVMSG)),
+			(*byte)(unsafe.Pointer(&sendRecvMsgFunc.recvAddr)),
+			uint32(unsafe.Sizeof(sendRecvMsgFunc.recvAddr)),
+			&n, nil, 0)
+		if sendRecvMsgFunc.err != nil {
+			return
+		}
+		sendRecvMsgFunc.err = WSAIoctl(s,
+			SIO_GET_EXTENSION_FUNCTION_POINTER,
+			(*byte)(unsafe.Pointer(&WSAID_WSASENDMSG)),
+			uint32(unsafe.Sizeof(WSAID_WSASENDMSG)),
+			(*byte)(unsafe.Pointer(&sendRecvMsgFunc.sendAddr)),
+			uint32(unsafe.Sizeof(sendRecvMsgFunc.sendAddr)),
+			&n, nil, 0)
+	})
+	return sendRecvMsgFunc.err
+}
+
+func WSASendMsg(fd Handle, msg *WSAMsg, flags uint32, bytesSent *uint32, overlapped *Overlapped, croutine *byte) error {
+	err := loadWSASendRecvMsg()
+	if err != nil {
+		return err
+	}
+	r1, _, e1 := syscall.Syscall6(sendRecvMsgFunc.sendAddr, 6, uintptr(fd), uintptr(unsafe.Pointer(msg)), uintptr(flags), uintptr(unsafe.Pointer(bytesSent)), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(croutine)))
+	if r1 == socket_error {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return err
+}
+
+func WSARecvMsg(fd Handle, msg *WSAMsg, bytesReceived *uint32, overlapped *Overlapped, croutine *byte) error {
+	err := loadWSASendRecvMsg()
+	if err != nil {
+		return err
+	}
+	r1, _, e1 := syscall.Syscall6(sendRecvMsgFunc.recvAddr, 5, uintptr(fd), uintptr(unsafe.Pointer(msg)), uintptr(unsafe.Pointer(bytesReceived)), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(croutine)), 0)
+	if r1 == socket_error {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return err
+}
+
 // Invented structures to support what package os expects.
 type Rusage struct {
 	CreationTime Filetime
diff --git a/windows/types_windows.go b/windows/types_windows.go
index 0229f79c..78b714c0 100644
--- a/windows/types_windows.go
+++ b/windows/types_windows.go
@@ -29,6 +29,7 @@ const (
 	ERROR_NOT_FOUND              syscall.Errno = 1168
 	ERROR_PRIVILEGE_NOT_HELD     syscall.Errno = 1314
 	WSAEACCES                    syscall.Errno = 10013
+	WSAEMSGSIZE                  syscall.Errno = 10040
 	WSAECONNRESET                syscall.Errno = 10054
 )
 
@@ -567,6 +568,16 @@ const (
 	IPV6_JOIN_GROUP     = 0xc
 	IPV6_LEAVE_GROUP    = 0xd
 
+	MSG_OOB       = 0x1
+	MSG_PEEK      = 0x2
+	MSG_DONTROUTE = 0x4
+	MSG_WAITALL   = 0x8
+
+	MSG_TRUNC  = 0x0100
+	MSG_CTRUNC = 0x0200
+	MSG_BCAST  = 0x0400
+	MSG_MCAST  = 0x0800
+
 	SOMAXCONN = 0x7fffffff
 
 	TCP_NODELAY = 1
@@ -584,6 +595,15 @@ type WSABuf struct {
 	Buf *byte
 }
 
+type WSAMsg struct {
+	Name        *syscall.RawSockaddrAny
+	Namelen     int32
+	Buffers     *WSABuf
+	BufferCount uint32
+	Control     WSABuf
+	Flags       uint32
+}
+
 // Invented values to support what package os expects.
 const (
 	S_IFMT   = 0x1f000
@@ -1011,6 +1031,20 @@ var WSAID_CONNECTEX = GUID{
 	[8]byte{0x8e, 0xe9, 0x76, 0xe5, 0x8c, 0x74, 0x06, 0x3e},
 }
 
+var WSAID_WSASENDMSG = GUID{
+	0xa441e712,
+	0x754f,
+	0x43ca,
+	[8]byte{0x84, 0xa7, 0x0d, 0xee, 0x44, 0xcf, 0x60, 0x6d},
+}
+
+var WSAID_WSARECVMSG = GUID{
+	0xf689d7c8,
+	0x6f1f,
+	0x436b,
+	[8]byte{0x8a, 0x53, 0xe5, 0x4f, 0xe3, 0x51, 0xc3, 0x22},
+}
+
 const (
 	FILE_SKIP_COMPLETION_PORT_ON_SUCCESS = 1
 	FILE_SKIP_SET_EVENT_ON_HANDLE        = 2