fixes #523 dialers could support multiple outstanding dial requests

fixes #179 DNS resolution should be done at connect time
fixes #586 Windows IO completion port work could be better
fixes #339 Windows iocp could use synchronous completions
fixes #280 TCP abstraction improvements

This is a rather monstrous set of changes, which refactors TCP, and
the underlying Windows I/O completion path logic, in order to obtain
a cleaner, simpler API, with support for asynchronous DNS lookups performed
on connect rather than initialization time, the ability to have multiple
connects or accepts pending, as well as fewer extraneous function calls.

The Windows code also benefits from greatly reduced context switching,
fewer lock operations performed, and a reduced number of system calls
on the hot code path.  (We use automatic event resetting instead of manual.)

Some dead code was removed as well, and a few potential edge case leaks
on failure paths (in the websocket code) were plugged.

Note that all TCP based transports benefit from this work. The IPC code
on Windows still uses the legacy IOCP for now, as does the UDP code (used
for ZeroTier.)  We will be converting those soon too.

1 files changed, 0 insertions, 703 deletions

diff --git a/src/platform/windows/win_tcp.c b/src/platform/windows/win_tcp.c
index 33c4a1a5..2ab6be0f 100644
--- a/src/platform/windows/win_tcp.c
+++ b/src/platform/windows/win_tcp.c
@@ -15,709 +15,6 @@
 #include <malloc.h>
 #include <stdio.h>
 
-struct nni_plat_tcp_pipe {
-	SOCKET           s;
-	nni_win_event    rcv_ev;
-	nni_win_event    snd_ev;
-	SOCKADDR_STORAGE sockname;
-	SOCKADDR_STORAGE peername;
-};
-
-struct nni_plat_tcp_ep {
-	SOCKET        s;
-	SOCKET        acc_s;
-	nni_win_event con_ev;
-	nni_win_event acc_ev;
-	int           started;
-	int           bound;
-
-	SOCKADDR_STORAGE remaddr;
-	int              remlen;
-	SOCKADDR_STORAGE locaddr;
-	int              loclen;
-
-	char buf[512]; // to hold acceptex results
-
-	// We have to lookup some function pointers using ioctls.  Winsock,
-	// gotta love it.  Especially I love that asynch accept means that
-	// getsockname and getpeername don't work.
-	LPFN_CONNECTEX            connectex;
-	LPFN_ACCEPTEX             acceptex;
-	LPFN_GETACCEPTEXSOCKADDRS getacceptexsockaddrs;
-};
-
-static int  nni_win_tcp_pipe_start(nni_win_event *, nni_aio *);
-static void nni_win_tcp_pipe_finish(nni_win_event *, nni_aio *);
-static void nni_win_tcp_pipe_cancel(nni_win_event *);
-
-static nni_win_event_ops nni_win_tcp_pipe_ops = {
-	.wev_start  = nni_win_tcp_pipe_start,
-	.wev_finish = nni_win_tcp_pipe_finish,
-	.wev_cancel = nni_win_tcp_pipe_cancel,
-};
-
-static int  nni_win_tcp_acc_start(nni_win_event *, nni_aio *);
-static void nni_win_tcp_acc_finish(nni_win_event *, nni_aio *);
-static void nni_win_tcp_acc_cancel(nni_win_event *);
-
-static nni_win_event_ops nni_win_tcp_acc_ops = {
-	.wev_start  = nni_win_tcp_acc_start,
-	.wev_finish = nni_win_tcp_acc_finish,
-	.wev_cancel = nni_win_tcp_acc_cancel,
-};
-
-static int  nni_win_tcp_con_start(nni_win_event *, nni_aio *);
-static void nni_win_tcp_con_finish(nni_win_event *, nni_aio *);
-static void nni_win_tcp_con_cancel(nni_win_event *);
-
-static nni_win_event_ops nni_win_tcp_con_ops = {
-	.wev_start  = nni_win_tcp_con_start,
-	.wev_finish = nni_win_tcp_con_finish,
-	.wev_cancel = nni_win_tcp_con_cancel,
-};
-
-static void
-nni_win_tcp_sockinit(SOCKET s)
-{
-	BOOL  yes;
-	DWORD no;
-
-	// Don't inherit the handle (CLOEXEC really).
-	SetHandleInformation((HANDLE) s, HANDLE_FLAG_INHERIT, 0);
-
-	no = 0;
-	(void) setsockopt(
-	    s, IPPROTO_IPV6, IPV6_V6ONLY, (char *) &no, sizeof(no));
-
-	// Also disable Nagle.  We are careful to group data with WSASend,
-	// and latency is king for most of our users.  (Consider adding
-	// a method to enable this later.)
-	yes = 1;
-	(void) setsockopt(
-	    s, IPPROTO_TCP, TCP_NODELAY, (char *) &yes, sizeof(yes));
-}
-
-static int
-nni_win_tcp_pipe_start(nni_win_event *evt, nni_aio *aio)
-{
-	int                rv;
-	SOCKET             s;
-	DWORD              niov;
-	DWORD              flags;
-	nni_plat_tcp_pipe *pipe = evt->ptr;
-	unsigned           i;
-	unsigned           naiov;
-	nni_iov *          aiov;
-	WSABUF *           iov;
-
-	nni_aio_get_iov(aio, &naiov, &aiov);
-	iov = _malloca(naiov * sizeof(*iov));
-
-	// Put the AIOs in Windows form.
-	for (niov = 0, i = 0; i < naiov; i++) {
-		if (aiov[i].iov_len != 0) {
-			iov[niov].buf = aiov[i].iov_buf;
-			iov[niov].len = (ULONG) aiov[i].iov_len;
-			niov++;
-		}
-	}
-
-	if ((s = pipe->s) == INVALID_SOCKET) {
-		_freea(iov);
-		evt->status = NNG_ECLOSED;
-		evt->count  = 0;
-		return (1);
-	}
-
-	// Note that the IOVs for the event were prepared on entry already.
-	// The actual aio's iov array we don't touch.
-
-	evt->count = 0;
-	flags      = 0;
-	if (evt == &pipe->snd_ev) {
-		rv = WSASend(s, iov, niov, NULL, flags, &evt->olpd, NULL);
-	} else {
-		rv = WSARecv(s, iov, niov, NULL, &flags, &evt->olpd, NULL);
-	}
-	_freea(iov);
-
-	if ((rv == SOCKET_ERROR) &&
-	    ((rv = GetLastError()) != ERROR_IO_PENDING)) {
-		// Synchronous failure.
-		evt->status = nni_win_error(rv);
-		evt->count  = 0;
-		return (1);
-	}
-
-	// Wait for the I/O completion event.  Note that when an I/O
-	// completes immediately, the I/O completion packet is still
-	// delivered.
-	return (0);
-}
-
-static void
-nni_win_tcp_pipe_cancel(nni_win_event *evt)
-{
-	nni_plat_tcp_pipe *pipe = evt->ptr;
-
-	(void) CancelIoEx((HANDLE) pipe->s, &evt->olpd);
-}
-
-static void
-nni_win_tcp_pipe_finish(nni_win_event *evt, nni_aio *aio)
-{
-	if ((evt->status == 0) && (evt->count == 0)) {
-		// Windows sometimes returns a zero read.  Convert these
-		// into an NNG_ECLOSED.  (We are never supposed to come
-		// back with zero length read.)
-		evt->status = NNG_ECLOSED;
-	}
-	nni_aio_finish(aio, evt->status, evt->count);
-}
-
-static int
-nni_win_tcp_pipe_init(nni_plat_tcp_pipe **pipep, SOCKET s)
-{
-	nni_plat_tcp_pipe *pipe;
-	int                rv;
-
-	if ((pipe = NNI_ALLOC_STRUCT(pipe)) == NULL) {
-		return (NNG_ENOMEM);
-	}
-	rv = nni_win_event_init(&pipe->rcv_ev, &nni_win_tcp_pipe_ops, pipe);
-	if (rv != 0) {
-		nni_plat_tcp_pipe_fini(pipe);
-		return (rv);
-	}
-	rv = nni_win_event_init(&pipe->snd_ev, &nni_win_tcp_pipe_ops, pipe);
-	if (rv != 0) {
-		nni_plat_tcp_pipe_fini(pipe);
-		return (rv);
-	}
-	nni_win_tcp_sockinit(s);
-	pipe->s = s;
-	*pipep  = pipe;
-	return (0);
-}
-
-void
-nni_plat_tcp_pipe_send(nni_plat_tcp_pipe *pipe, nni_aio *aio)
-{
-	nni_win_event_submit(&pipe->snd_ev, aio);
-}
-
-void
-nni_plat_tcp_pipe_recv(nni_plat_tcp_pipe *pipe, nni_aio *aio)
-{
-	nni_win_event_submit(&pipe->rcv_ev, aio);
-}
-
-void
-nni_plat_tcp_pipe_close(nni_plat_tcp_pipe *pipe)
-{
-	SOCKET s;
-
-	nni_win_event_close(&pipe->rcv_ev);
-
-	if ((s = pipe->s) != INVALID_SOCKET) {
-		pipe->s = INVALID_SOCKET;
-		closesocket(s);
-	}
-}
-
-int
-nni_plat_tcp_pipe_peername(nni_plat_tcp_pipe *pipe, nni_sockaddr *sa)
-{
-	if (nni_win_sockaddr2nn(sa, &pipe->peername) < 0) {
-		return (NNG_EADDRINVAL);
-	}
-	return (0);
-}
-
-int
-nni_plat_tcp_pipe_sockname(nni_plat_tcp_pipe *pipe, nni_sockaddr *sa)
-{
-	if (nni_win_sockaddr2nn(sa, &pipe->sockname) < 0) {
-		return (NNG_EADDRINVAL);
-	}
-	return (0);
-}
-
-int
-nni_plat_tcp_pipe_set_nodelay(nni_plat_tcp_pipe *pipe, bool val)
-{
-	BOOL b;
-	b = val ? TRUE : FALSE;
-	if (setsockopt(pipe->s, IPPROTO_TCP, TCP_NODELAY, (void *) &b,
-	        sizeof(b)) != 0) {
-		return (nni_win_error(WSAGetLastError()));
-	}
-	return (0);
-}
-
-int
-nni_plat_tcp_pipe_set_keepalive(nni_plat_tcp_pipe *pipe, bool val)
-{
-	BOOL b;
-	b = val ? TRUE : FALSE;
-	if (setsockopt(pipe->s, SOL_SOCKET, SO_KEEPALIVE, (void *) &b,
-	        sizeof(b)) != 0) {
-		return (nni_win_error(WSAGetLastError()));
-	}
-	return (0);
-}
-
-void
-nni_plat_tcp_pipe_fini(nni_plat_tcp_pipe *pipe)
-{
-	nni_plat_tcp_pipe_close(pipe);
-
-	nni_win_event_fini(&pipe->snd_ev);
-	nni_win_event_fini(&pipe->rcv_ev);
-	NNI_FREE_STRUCT(pipe);
-}
-
-int
-nni_plat_tcp_ep_init(nni_plat_tcp_ep **epp, const nni_sockaddr *lsa,
-    const nni_sockaddr *rsa, int mode)
-{
-	nni_plat_tcp_ep *ep;
-	int              rv;
-	SOCKET           s;
-	DWORD            nbytes;
-	GUID             guid1 = WSAID_CONNECTEX;
-	GUID             guid2 = WSAID_ACCEPTEX;
-	GUID             guid3 = WSAID_GETACCEPTEXSOCKADDRS;
-
-	NNI_ARG_UNUSED(mode);
-
-	if ((ep = NNI_ALLOC_STRUCT(ep)) == NULL) {
-		return (NNG_ENOMEM);
-	}
-	ZeroMemory(ep, sizeof(*ep));
-
-	ep->s = INVALID_SOCKET;
-
-	if ((rsa != NULL) && (rsa->s_family != NNG_AF_UNSPEC)) {
-		ep->remlen = nni_win_nn2sockaddr(&ep->remaddr, rsa);
-	}
-	if ((lsa != NULL) && (lsa->s_family != NNG_AF_UNSPEC)) {
-		ep->loclen = nni_win_nn2sockaddr(&ep->locaddr, lsa);
-	}
-
-	// Create a scratch socket for use with ioctl.
-	s = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
-	if (s == INVALID_SOCKET) {
-		rv = nni_win_error(GetLastError());
-		goto fail;
-	}
-
-	// Look up the function pointer.
-	if (WSAIoctl(s, SIO_GET_EXTENSION_FUNCTION_POINTER, &guid1,
-	        sizeof(guid1), &ep->connectex, sizeof(ep->connectex), &nbytes,
-	        NULL, NULL) == SOCKET_ERROR) {
-		rv = nni_win_error(GetLastError());
-		goto fail;
-	}
-	if (WSAIoctl(s, SIO_GET_EXTENSION_FUNCTION_POINTER, &guid2,
-	        sizeof(guid2), &ep->acceptex, sizeof(ep->acceptex), &nbytes,
-	        NULL, NULL) == SOCKET_ERROR) {
-		rv = nni_win_error(GetLastError());
-		goto fail;
-	}
-	if (WSAIoctl(s, SIO_GET_EXTENSION_FUNCTION_POINTER, &guid3,
-	        sizeof(guid3), &ep->getacceptexsockaddrs,
-	        sizeof(ep->getacceptexsockaddrs), &nbytes, NULL,
-	        NULL) == SOCKET_ERROR) {
-		rv = nni_win_error(GetLastError());
-		goto fail;
-	}
-
-	closesocket(s);
-	s = INVALID_SOCKET;
-
-	// Now initialize the win events for later use.
-	rv = nni_win_event_init(&ep->acc_ev, &nni_win_tcp_acc_ops, ep);
-	if (rv != 0) {
-		goto fail;
-	}
-	rv = nni_win_event_init(&ep->con_ev, &nni_win_tcp_con_ops, ep);
-	if (rv != 0) {
-		goto fail;
-	}
-
-	*epp = ep;
-	return (0);
-
-fail:
-	if (s != INVALID_SOCKET) {
-		closesocket(s);
-	}
-	nni_plat_tcp_ep_fini(ep);
-	return (rv);
-}
-
-void
-nni_plat_tcp_ep_close(nni_plat_tcp_ep *ep)
-{
-	nni_win_event_close(&ep->acc_ev);
-	nni_win_event_close(&ep->con_ev);
-	if (ep->s != INVALID_SOCKET) {
-		closesocket(ep->s);
-		ep->s = INVALID_SOCKET;
-	}
-	if (ep->acc_s != INVALID_SOCKET) {
-		closesocket(ep->acc_s);
-	}
-}
-
-void
-nni_plat_tcp_ep_fini(nni_plat_tcp_ep *ep)
-{
-	nni_plat_tcp_ep_close(ep);
-	NNI_FREE_STRUCT(ep);
-}
-
-static int
-nni_win_tcp_listen(nni_plat_tcp_ep *ep, nni_sockaddr *bsa)
-{
-	int    rv;
-	BOOL   yes;
-	SOCKET s;
-
-	if (ep->started) {
-		return (NNG_EBUSY);
-	}
-
-	s = socket(ep->locaddr.ss_family, SOCK_STREAM, IPPROTO_TCP);
-	if (s == INVALID_SOCKET) {
-		rv = nni_win_error(GetLastError());
-		goto fail;
-	}
-
-	nni_win_tcp_sockinit(s);
-
-	if ((rv = nni_win_iocp_register((HANDLE) s)) != 0) {
-		goto fail;
-	}
-
-	// Make sure that we use the address exclusively.  Windows lets
-	// others hijack us by default.
-	yes = 1;
-
-	rv = setsockopt(
-	    s, SOL_SOCKET, SO_EXCLUSIVEADDRUSE, (char *) &yes, sizeof(yes));
-	if (rv != 0) {
-		rv = nni_win_error(GetLastError());
-		goto fail;
-	}
-	if (bind(s, (struct sockaddr *) &ep->locaddr, ep->loclen) != 0) {
-		rv = nni_win_error(GetLastError());
-		goto fail;
-	}
-
-	if (bsa != NULL) {
-		SOCKADDR_STORAGE bound;
-		int              len = sizeof(bound);
-		rv = getsockname(s, (SOCKADDR *) &bound, &len);
-		if (rv != 0) {
-			rv = nni_win_error(GetLastError());
-			goto fail;
-		}
-		nni_win_sockaddr2nn(bsa, &bound);
-	}
-
-	if (listen(s, SOMAXCONN) != 0) {
-		rv = nni_win_error(GetLastError());
-		goto fail;
-	}
-
-	ep->s       = s;
-	ep->started = 1;
-
-	return (0);
-
-fail:
-	if (s != INVALID_SOCKET) {
-		closesocket(s);
-	}
-	return (rv);
-}
-
-int
-nni_plat_tcp_ep_listen(nni_plat_tcp_ep *ep, nng_sockaddr *bsa)
-{
-	int rv;
-
-	nni_mtx_lock(&ep->acc_ev.mtx);
-	rv = nni_win_tcp_listen(ep, bsa);
-	nni_mtx_unlock(&ep->acc_ev.mtx);
-	return (rv);
-}
-
-static void
-nni_win_tcp_acc_cancel(nni_win_event *evt)
-{
-	nni_plat_tcp_ep *ep = evt->ptr;
-	SOCKET           s  = ep->s;
-
-	if (s != INVALID_SOCKET) {
-		CancelIoEx((HANDLE) s, &evt->olpd);
-	}
-}
-
-static void
-nni_win_tcp_acc_finish(nni_win_event *evt, nni_aio *aio)
-{
-	nni_plat_tcp_ep *  ep = evt->ptr;
-	nni_plat_tcp_pipe *pipe;
-	SOCKET             s;
-	int                rv;
-	int                len1;
-	int                len2;
-	SOCKADDR *         sa1;
-	SOCKADDR *         sa2;
-
-	s         = ep->acc_s;
-	ep->acc_s = INVALID_SOCKET;
-
-	if (s == INVALID_SOCKET) {
-		return;
-	}
-
-	if (((rv = evt->status) != 0) ||
-	    ((rv = nni_win_iocp_register((HANDLE) s)) != 0) ||
-	    ((rv = nni_win_tcp_pipe_init(&pipe, s)) != 0)) {
-		closesocket(s);
-		nni_aio_finish_error(aio, rv);
-		return;
-	}
-
-	// Collect the local and peer addresses, because normal getsockname
-	// and getpeername don't work with AcceptEx.
-	len1 = (int) sizeof(pipe->sockname);
-	len2 = (int) sizeof(pipe->peername);
-	ep->getacceptexsockaddrs(
-	    ep->buf, 0, 256, 256, &sa1, &len1, &sa2, &len2);
-	NNI_ASSERT(len1 > 0);
-	NNI_ASSERT(len1 < (int) sizeof(SOCKADDR_STORAGE));
-	NNI_ASSERT(len2 > 0);
-	NNI_ASSERT(len2 < (int) sizeof(SOCKADDR_STORAGE));
-	memcpy(&pipe->sockname, sa1, len1);
-	memcpy(&pipe->peername, sa2, len2);
-
-	nni_aio_set_output(aio, 0, pipe);
-	nni_aio_finish(aio, 0, 0);
-}
-
-static int
-nni_win_tcp_acc_start(nni_win_event *evt, nni_aio *aio)
-{
-	nni_plat_tcp_ep *ep = evt->ptr;
-	SOCKET           s  = ep->s;
-	SOCKET           acc_s;
-	DWORD            cnt;
-
-	NNI_ARG_UNUSED(aio);
-
-	acc_s = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
-	if (acc_s == INVALID_SOCKET) {
-		evt->status = nni_win_error(GetLastError());
-		evt->count  = 0;
-		return (1);
-	}
-	ep->acc_s = acc_s;
-
-	if (!ep->acceptex(s, acc_s, ep->buf, 0, 256, 256, &cnt, &evt->olpd)) {
-		int rv = GetLastError();
-		switch (rv) {
-		case ERROR_IO_PENDING:
-			// Normal asynchronous operation.  Wait for
-			// completion.
-			return (0);
-
-		default:
-			// Fast-fail (synchronous).
-			evt->status = nni_win_error(rv);
-			evt->count  = 0;
-			return (1);
-		}
-	}
-
-	// Synch completion right now.  I/O completion packet delivered
-	// already.
-	return (0);
-}
-
-void
-nni_plat_tcp_ep_accept(nni_plat_tcp_ep *ep, nni_aio *aio)
-{
-	nni_win_event_submit(&ep->acc_ev, aio);
-}
-
-static void
-nni_win_tcp_con_cancel(nni_win_event *evt)
-{
-	nni_plat_tcp_ep *ep = evt->ptr;
-	SOCKET           s  = ep->s;
-
-	if (s != INVALID_SOCKET) {
-		CancelIoEx((HANDLE) s, &evt->olpd);
-	}
-}
-
-static void
-nni_win_tcp_con_finish(nni_win_event *evt, nni_aio *aio)
-{
-	nni_plat_tcp_ep *  ep = evt->ptr;
-	nni_plat_tcp_pipe *pipe;
-	SOCKET             s;
-	int                rv;
-	DWORD              yes = 1;
-	int                len;
-
-	s     = ep->s;
-	ep->s = INVALID_SOCKET;
-
-	// The socket was already registered with the IOCP.
-
-	if (((rv = evt->status) != 0) ||
-	    ((rv = nni_win_tcp_pipe_init(&pipe, s)) != 0)) {
-		// The new pipe is already fine for us.  Discard
-		// the old one, since failed to be able to use it.
-		closesocket(s);
-		nni_aio_finish_error(aio, rv);
-		return;
-	}
-
-	(void) setsockopt(s, SOL_SOCKET, SO_UPDATE_CONNECT_CONTEXT,
-	    (char *) &yes, sizeof(yes));
-
-	// Windows seems to be unable to get peernames for sockets on
-	// connect - perhaps because we supplied it already with connectex.
-	// Rather than debugging it, just steal the address from the endpoint.
-	memcpy(&pipe->peername, &ep->remaddr, ep->remlen);
-
-	len = sizeof(pipe->sockname);
-	(void) getsockname(s, (SOCKADDR *) &pipe->sockname, &len);
-
-	nni_aio_set_output(aio, 0, pipe);
-	nni_aio_finish(aio, 0, 0);
-}
-
-static int
-nni_win_tcp_con_start(nni_win_event *evt, nni_aio *aio)
-{
-	nni_plat_tcp_ep *ep = evt->ptr;
-	SOCKET           s;
-	SOCKADDR_STORAGE bss;
-	int              len;
-	int              rv;
-	int              family;
-
-	NNI_ARG_UNUSED(aio);
-
-	if (ep->loclen > 0) {
-		family = ep->locaddr.ss_family;
-	} else {
-		family = ep->remaddr.ss_family;
-	}
-
-	s = socket(family, SOCK_STREAM, IPPROTO_TCP);
-	if (s == INVALID_SOCKET) {
-		evt->status = nni_win_error(GetLastError());
-		evt->count  = 0;
-		return (1);
-	}
-
-	nni_win_tcp_sockinit(s);
-
-	// Windows ConnectEx requires the socket to be bound first.
-	if (ep->loclen > 0) {
-		bss = ep->locaddr;
-		len = ep->loclen;
-	} else {
-		ZeroMemory(&bss, sizeof(bss));
-		bss.ss_family = ep->remaddr.ss_family;
-		len           = ep->remlen;
-	}
-	if (bind(s, (struct sockaddr *) &bss, len) < 0) {
-		evt->status = nni_win_error(GetLastError());
-		evt->count  = 0;
-		closesocket(s);
-
-		return (1);
-	}
-	// Register with the I/O completion port so we can get the
-	// events for the next call.
-	if ((rv = nni_win_iocp_register((HANDLE) s)) != 0) {
-		closesocket(s);
-		evt->status = rv;
-		evt->count  = 0;
-		return (1);
-	}
-
-	ep->s = s;
-	if (!ep->connectex(s, (struct sockaddr *) &ep->remaddr, ep->remlen,
-	        NULL, 0, NULL, &evt->olpd)) {
-		if ((rv = GetLastError()) != ERROR_IO_PENDING) {
-			closesocket(s);
-			ep->s       = INVALID_SOCKET;
-			evt->status = nni_win_error(rv);
-			evt->count  = 0;
-			return (1);
-		}
-	}
-	return (0);
-}
-
-extern void
-nni_plat_tcp_ep_connect(nni_plat_tcp_ep *ep, nni_aio *aio)
-{
-	nni_win_event_submit(&ep->con_ev, aio);
-}
-
-int
-nni_plat_tcp_ntop(const nni_sockaddr *sa, char *ipstr, char *portstr)
-{
-	void *   ap;
-	uint16_t port;
-	int      af;
-	switch (sa->s_family) {
-	case NNG_AF_INET:
-		ap   = (void *) &sa->s_in.sa_addr;
-		port = sa->s_in.sa_port;
-		af   = AF_INET;
-		break;
-	case NNG_AF_INET6:
-		ap   = (void *) &sa->s_in6.sa_addr;
-		port = sa->s_in6.sa_port;
-		af   = AF_INET6;
-		break;
-	default:
-		return (NNG_EINVAL);
-	}
-	if (ipstr != NULL) {
-		if (af == AF_INET6) {
-			size_t l;
-			ipstr[0] = '[';
-			InetNtopA(af, ap, ipstr + 1, INET6_ADDRSTRLEN);
-			l          = strlen(ipstr);
-			ipstr[l++] = ']';
-			ipstr[l++] = '\0';
-		} else {
-			InetNtopA(af, ap, ipstr, INET6_ADDRSTRLEN);
-		}
-	}
-	if (portstr != NULL) {
-#ifdef NNG_LITTLE_ENDIAN
-		port = ((port >> 8) & 0xff) | ((port & 0xff) << 8);
-#endif
-		snprintf(portstr, 6, "%u", port);
-	}
-	return (0);
-}
-
 int
 nni_win_tcp_sysinit(void)
 {