diff --git a/contrib/win32/w32-posix-prototype/win32posix/Tests/unittest1.cpp b/contrib/win32/w32-posix-prototype/win32posix/Tests/unittest1.cpp
index 9cdeabf..8f42ebb 100644
--- a/contrib/win32/w32-posix-prototype/win32posix/Tests/unittest1.cpp
+++ b/contrib/win32/w32-posix-prototype/win32posix/Tests/unittest1.cpp
@@ -87,6 +87,22 @@ namespace UnitTests
                 exit(1);
             }
 
+            fcntl(sockfd, F_SETFL, O_NONBLOCK);
+
+            fd_set read_set, write_set, except_set;
+
+            ZeroMemory(&read_set, sizeof(fd_set));
+            ZeroMemory(&write_set, sizeof(fd_set));
+            ZeroMemory(&except_set, sizeof(fd_set));
+
+            FD_SET(sockfd, &read_set);
+            struct timeval timeout;
+            timeout.tv_sec = 30;
+            timeout.tv_usec = 0;
+            int ret = select(sockfd, &read_set, &write_set, &except_set, &timeout);
+
+            new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size);
+
         }
 
 
diff --git a/contrib/win32/w32-posix-prototype/win32posix/win32posix/socketio.c b/contrib/win32/w32-posix-prototype/win32posix/win32posix/socketio.c
index b9b578a..d0590fe 100644
--- a/contrib/win32/w32-posix-prototype/win32posix/win32posix/socketio.c
+++ b/contrib/win32/w32-posix-prototype/win32posix/win32posix/socketio.c
@@ -3,6 +3,7 @@
 #include <mswsock.h>
 #include <errno.h>
 #include "w32fd.h"
+#include <stddef.h>
 
 
 static int getWSAErrno()
@@ -64,28 +65,6 @@ struct w32_io* socketio_socket(int domain, int type, int protocol) {
 	return pio;
 }
 
-struct w32_io* socketio_accept(struct w32_io* pio, struct sockaddr* addr, int* addrlen) {
-    struct w32_io *accept_io = NULL;
-    
-    accept_io = (struct w32_io*)malloc(sizeof(struct w32_io));
-    if (!accept_io)
-    {
-        errno = ENOMEM;
-        return NULL;
-    }
-
-    accept_io->sock = accept(pio->sock, addr, addrlen);
-    if (accept_io->sock == INVALID_SOCKET) {
-        errno = getWSAErrno();
-        free(accept_io);
-        return NULL;
-    }
-
-    pio->type = SOCK_FD;
-    return accept_io;
-}
-
-
 int socketio_setsockopt(struct w32_io* pio, int level, int optname, const char* optval, int optlen) {
     return set_errno_on_error(setsockopt(pio->sock, level, optname, optval, optlen));
 }
@@ -115,6 +94,147 @@ int socketio_connect(struct w32_io* pio, const struct sockaddr* name, int namele
     return set_errno_on_error(connect(pio->sock, name, namelen));
 }
 
+void CALLBACK WSARecvCompletionRoutine(
+    IN DWORD dwError,
+    IN DWORD cbTransferred,
+    IN LPWSAOVERLAPPED lpOverlapped,
+    IN DWORD dwFlags
+    )
+{
+    struct w32_io* pio = lpOverlapped - offsetof(struct w32_io, read_overlapped);
+    pio->read_details.error = dwError;
+    pio->read_details.remaining = cbTransferred;
+    pio->read_details.completed = 0;
+    pio->read_details.pending = FALSE;
+}
+
+int socketio_recv(struct w32_io* pio, void *buf, size_t len, int flags) {
+    int ret = 0;
+    DWORD bytes_received;
+
+    //if io is already pending
+    if (pio->read_details.pending)
+    {
+        errno = EAGAIN;
+        return -1;
+    }
+
+    //initialize recv buffers if needed
+    if (pio->read_overlapped.hEvent == NULL)
+    {
+        WSABUF* wsabuf = malloc(sizeof(WSABUF));
+        if (wsabuf) {
+            wsabuf->len = 1024;
+            wsabuf->buf = malloc(wsabuf->len);
+        }
+    
+        if (!wsabuf || !wsabuf->buf)
+        {
+            if (wsabuf)
+                free(wsabuf);
+            errno = ENOMEM;
+            return -1;
+        }
+
+        pio->read_overlapped.hEvent = (HANDLE)wsabuf;
+    }
+
+    //if we have some buffer copy it and retun #bytes copied
+    if (pio->read_details.remaining)
+    {
+        int num_bytes_copied = min(len, pio->read_details.remaining);
+        memcpy(buf, pio->read_overlapped.hEvent, num_bytes_copied);
+        pio->read_details.remaining -= num_bytes_copied;
+        return num_bytes_copied;
+    }
+
+    //TODO - implement flags if any needed for OpenSSH
+    ret = WSARecv(pio->sock, (WSABUF*)pio->read_overlapped.hEvent, 1, &bytes_received, 0, &pio->read_overlapped, &WSARecvCompletionRoutine);
+    if (ret == 0)
+    {   
+        //receive has completed and APC is scheduled, let it run
+        pio->read_details.pending = TRUE;
+        SleepEx(1, TRUE);
+        if ((pio->read_details.pending == FALSE) || (pio->read_details.remaining == 0)) {
+            errno = EOTHER;
+            return -1;
+        }
+
+        //we should have some bytes copied to internal buffer
+    }
+    else if (ret == WSA_IO_PENDING) {
+        //io is initiated and pending
+        pio->read_details.pending = TRUE;
+
+        if (w32_io_is_blocking(pio))
+        {
+            //wait until io is done
+            while (pio->read_details.pending)
+                SleepEx(INFINITE, TRUE);
+        }
+        else {
+            errno = EAGAIN;
+            return -1;
+        }
+    }
+    else { //failed 
+        errno = getWSAErrno();
+        return -1;
+    }
+
+    //by this time we should have some bytes in internal buffer
+    //if we have some buffer copy it and retun #bytes copied
+    if (pio->read_details.remaining)
+    {
+        int num_bytes_copied = min(len, pio->read_details.remaining);
+        memcpy(buf, pio->read_overlapped.hEvent, num_bytes_copied);
+        pio->read_details.remaining -= num_bytes_copied;
+        return num_bytes_copied;
+    }
+    else {
+        errno = EOTHER;
+        return -1;
+    }
+
+}
+
+void CALLBACK WSASendCompletionRoutine(
+    IN DWORD dwError,
+    IN DWORD cbTransferred,
+    IN LPWSAOVERLAPPED lpOverlapped,
+    IN DWORD dwFlags
+    )
+{
+    struct w32_io* pio = lpOverlapped - offsetof(struct w32_io, write_overlapped);
+    pio->write_details.error = dwError;
+    //assert that remaining == cbTransferred
+    pio->write_details.remaining -= cbTransferred;
+    pio->write_details.pending = FALSE;
+}
+
+int socketio_send(struct w32_io* pio, const void *buf, size_t len, int flags) {
+    
+    if (pio->write_overlapped.hEvent == NULL)
+    {
+        WSABUF* wsabuf = malloc(sizeof(WSABUF));
+        if (wsabuf) {
+            wsabuf->len = 1024;
+            wsabuf->buf = malloc(wsabuf->len);
+        }
+
+        if (!wsabuf || !wsabuf->buf)
+        {
+            if (wsabuf)
+                free(wsabuf);
+            errno = ENOMEM;
+            return -1;
+        }
+
+        pio->write_overlapped.hEvent = (HANDLE)wsabuf;
+    }
+}
+
+
 int socketio_shutdown(struct w32_io* pio, int how) {
     return set_errno_on_error(shutdown(pio->sock, how));
 }
@@ -133,7 +253,77 @@ struct acceptEx_context {
     DWORD bytes_received;
 };
 
-int socketio_start_asyncio(struct w32_io* pio, BOOL read) {
+
+struct w32_io* socketio_accept(struct w32_io* pio, struct sockaddr* addr, int* addrlen) {
+    struct w32_io *accept_io = NULL;
+
+    accept_io = (struct w32_io*)malloc(sizeof(struct w32_io));
+    if (!accept_io)
+    {
+        errno = ENOMEM;
+        return NULL;
+    }
+
+    if (w32_io_is_blocking(pio)) {
+        accept_io->sock = accept(pio->sock, addr, addrlen);
+        if (accept_io->sock == INVALID_SOCKET) {
+            errno = getWSAErrno();
+            free(accept_io);
+            return NULL;
+        }
+    }
+    else {
+        //ensure i/o is ready
+        if (FALSE == socketio_is_ioready(pio, TRUE)) {
+            free(accept_io);
+            errno = EAGAIN;
+            return -1;
+        }
+
+        struct acceptEx_context* context = (struct acceptEx_context*)pio->context;
+
+        accept_io->sock = context->accept_socket;
+        context->accept_socket = INVALID_SOCKET;
+        pio->read_details.pending = FALSE;
+        ResetEvent(pio->read_overlapped.hEvent);
+    }
+
+    pio->type = SOCK_FD;
+    return accept_io;
+}
+
+BOOL socketio_is_ioready(struct w32_io* pio, BOOL rd) {
+    struct acceptEx_context* context = (struct acceptEx_context*)pio->context;
+
+    if (w32_io_is_blocking(pio))
+        return FALSE;
+
+    if (pio->type == LISTEN_FD) {
+        DWORD numBytes = 0;
+        if (pio->read_details.pending && GetOverlappedResult(pio->read_overlapped.hEvent, &pio->read_overlapped, &numBytes, FALSE)) {
+            return TRUE;
+        }
+        else {
+            if (pio->read_details.pending && GetLastError() != ERROR_IO_INCOMPLETE) {
+                //unexpected error;
+            }
+            return FALSE;
+        }
+    }
+    else { //regular socket
+        //todo
+        return FALSE;
+    }
+    
+}
+
+int socketio_start_asyncio(struct w32_io* pio, BOOL rd) {
+
+    if (w32_io_is_blocking(pio)) {
+        errno = EPERM;
+        return -1;
+    }
+
     if (pio->type == LISTEN_FD) {
         if (!pio->read_details.pending) {
             struct acceptEx_context *context;
@@ -181,7 +371,7 @@ int socketio_start_asyncio(struct w32_io* pio, BOOL read) {
                 return -1;
             }
 
-            if (FALSE == context->lpfnAcceptEx(pio->sock,
+            if (TRUE == context->lpfnAcceptEx(pio->sock,
                 context->accept_socket,
                 context->lpOutputBuf,
                 0,
@@ -190,9 +380,15 @@ int socketio_start_asyncio(struct w32_io* pio, BOOL read) {
                 &context->bytes_received,
                 &pio->read_overlapped))
             {
-
-                errno = getWSAErrno();
-                return -1;
+                //we are already connected. Set event so subsequent select will catch
+                SetEvent(pio->read_overlapped.hEvent);
+            }
+            else {
+                //if overlapped io is in progress, we are good
+                if (WSAGetLastError() != ERROR_IO_PENDING) {
+                    errno = getWSAErrno();
+                    return -1;
+                }
             }
 
             pio->read_details.pending = TRUE;
diff --git a/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32fd.c b/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32fd.c
index ba61e0c..b837c0a 100644
--- a/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32fd.c
+++ b/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32fd.c
@@ -1,6 +1,7 @@
 #include "w32posix.h"
 #include "w32fd.h"
 #include <stdarg.h>
+#include <errno.h>
 
 struct w32fd_table {
     w32_fd_set occupied;
@@ -24,8 +25,10 @@ int fd_table_get_min_index() {
     {
         bitmap++;
         min_index += 8;
-        if (min_index >= MAX_FDS)
+        if (min_index >= MAX_FDS) {
+            errno = ENOMEM;
             return -1;
+        }
     }
 
     tmp = *bitmap;
@@ -54,6 +57,7 @@ void fd_table_clear(int index)
 }
 
 void w32posix_initialize() {
+    fd_table_initialize();
     socketio_initialize();
 }
 
@@ -63,7 +67,30 @@ void w32posix_done() {
 
 BOOL w32_io_is_blocking(struct w32_io* pio)
 {
-    return (pio->fd_status_flags & O_NONBLOCK) ? TRUE : FALSE;
+    return (pio->fd_status_flags & O_NONBLOCK) ? FALSE : TRUE;
+}
+
+BOOL w32_io_is_ioready(struct w32_io* pio, BOOL rd) {
+    if ((pio->type == LISTEN_FD) || (pio->type == SOCK_FD)) {
+        return socketio_is_ioready(pio, rd);
+    }
+    else {
+        //return fileio_is_ready(pio);
+        return FALSE;
+    }
+
+}
+
+int w32_io_start_asyncio(struct w32_io* pio, BOOL rd)
+{
+    if ((pio->type == LISTEN_FD) || (pio->type == SOCK_FD)) {
+        return socketio_start_asyncio(pio, rd);
+    }
+    else {
+        //return fileio_is_ready(pio);
+        return -1;
+    }
+
 }
 
 int w32_socket(int domain, int type, int protocol) {
@@ -71,9 +98,7 @@ int w32_socket(int domain, int type, int protocol) {
     struct w32_io* pio = NULL;
 
     if (min_index == -1)
-    {
         return -1;
-    }
 
     pio = socketio_socket(domain, type, protocol);
     if (!pio) {
@@ -90,9 +115,7 @@ int w32_accept(int fd, struct sockaddr* addr, int* addrlen)
     struct w32_io* pio = NULL;
 
     if (min_index == -1)
-    {
         return -1;
-    }
 
     pio = socketio_accept(fd_table.w32_ios[fd], addr, addrlen);
     if (!pio) {
@@ -131,6 +154,15 @@ int w32_connect(int fd, const struct sockaddr* name, int namelen) {
     return socketio_connect(fd_table.w32_ios[fd], name, namelen);
 }
 
+int w32_recv(int fd, void *buf, size_t len, int flags) {
+    return socketio_recv(fd_table.w32_ios[fd], buf, len, flags);
+}
+
+int w32_send(int fd, const void *buf, size_t len, int flags) {
+    return socketio_send(fd_table.w32_ios[fd], buf, len, flags);
+}
+
+
 int w32_shutdown(int fd, int how) {
     return socketio_shutdown(fd_table.w32_ios[fd], how);
 }
@@ -140,8 +172,7 @@ int w32_close(int fd) {
 
     fd_table_clear(pio->table_index);
     if ((pio->type == LISTEN_FD) || (pio->type == SOCK_FD)) {
-        socketio_close(pio);
-        return 0;
+        return socketio_close(pio);
     }
     else
         return -1;
@@ -159,10 +190,158 @@ int w32_fcntl(int fd, int cmd, ... /* arg */) {
         return 0;
     case F_GETFD:
         return fd_table.w32_ios[fd]->fd_flags;
-        break;
+        return 0;
     case F_SETFD:
         fd_table.w32_ios[fd]->fd_flags = va_arg(valist, int);
         return 0;
+    default:
+        errno = EINVAL;
+        return -1;
     }
 }
 
+int w32_select(int fds, fd_set* readfds, fd_set* writefds, fd_set* exceptfds, const struct timeval *timeout) {
+    int in_ready_fds = 0, out_ready_fds = 0;
+    fd_set read_ready_fds, write_ready_fds;
+    HANDLE events[10];
+    int num_events = 0;
+
+    memset(&read_ready_fds, 0, sizeof(fd_set));
+    memset(&write_ready_fds, 0, sizeof(fd_set));
+
+    if (fds > MAX_FDS - 1) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    //see if any io is ready
+    for (int i = 0; i <= fds; i++) {
+
+        if FD_ISSET(i, readfds) {
+            if (fd_table.w32_ios[i] == NULL) {
+                errno = EPERM;
+                return -1;
+            }
+
+            in_ready_fds++;
+            if (w32_io_is_ioready(fd_table.w32_ios[i], TRUE)) {
+                FD_SET(i, &read_ready_fds);
+                out_ready_fds++;
+            }
+        }
+
+        if FD_ISSET(i, writefds) {
+            if (fd_table.w32_ios[i] == NULL) {
+                errno = EPERM;
+                return -1;
+            }
+
+            in_ready_fds++;
+            if (w32_io_is_ioready(fd_table.w32_ios[i], FALSE)) {
+                FD_SET(i, &write_ready_fds);
+                out_ready_fds++;
+            }
+        }
+
+    }
+
+    //if none of input fds are set return error
+    if (in_ready_fds == 0) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    //if some fds are already ready, return
+    if (out_ready_fds)
+    {
+        *readfds = read_ready_fds;
+        *writefds = write_ready_fds;
+        return out_ready_fds;
+    }
+
+    //start async io on selected fds
+    for (int i = 0; i <= fds; i++) {
+
+        if FD_ISSET(i, readfds) {
+            if (w32_io_start_asyncio(fd_table.w32_ios[i], TRUE) == -1)
+                return -1;
+            if (fd_table.w32_ios[i]->type == LISTEN_FD) {
+                events[num_events++] = fd_table.w32_ios[i]->read_overlapped.hEvent;
+            }
+        }
+
+        if FD_ISSET(i, writefds) {
+            if (w32_io_start_asyncio(fd_table.w32_ios[i], FALSE) == -1)
+                return -1;
+        }
+    }
+
+    //wait for any io to complete
+    if (num_events)
+    {
+        DWORD ret = WaitForMultipleObjectsEx(num_events, events, FALSE, ((timeout->tv_sec) * 1000) + ((timeout->tv_usec) / 1000), TRUE);
+        if ((ret >= WAIT_OBJECT_0) && (ret <= WAIT_OBJECT_0 + num_events - 1)) {
+            //woken up by event signalled
+        }
+        else if (ret == WAIT_IO_COMPLETION) {
+            //woken up by APC from IO completion
+        }
+        else if (ret == WAIT_TIMEOUT) {
+            errno = ETIMEDOUT;
+            return -1;
+        }
+        else { //some other error
+            errno = EOTHER;
+            return -1;
+        }
+    }
+    else
+    {
+        DWORD ret = SleepEx(((timeout->tv_sec) * 1000) + ((timeout->tv_usec) / 1000), TRUE);
+        if (ret == WAIT_IO_COMPLETION) {
+            //worken up by APC from IO completion
+        }
+        else if (ret == 0) {
+            //timed out
+            errno = ETIMEDOUT;
+            return -1;
+        }
+        else { //some other error
+            errno = EOTHER;
+            return -1;
+        }
+    }
+
+    //check on fd status
+    out_ready_fds = 0;
+    for (int i = 0; i <= fds; i++) {
+
+        if FD_ISSET(i, readfds) {
+            in_ready_fds++;
+            if (w32_io_is_ioready(fd_table.w32_ios[i], TRUE)) {
+                FD_SET(i, &read_ready_fds);
+                out_ready_fds++;
+            }
+        }
+
+        if FD_ISSET(i, writefds) {
+            in_ready_fds++;
+            if (w32_io_is_ioready(fd_table.w32_ios[i], FALSE)) {
+                FD_SET(i, &write_ready_fds);
+                out_ready_fds++;
+            }
+        }
+
+    }
+
+    if (out_ready_fds)
+    {
+        *readfds = read_ready_fds;
+        *writefds = write_ready_fds;
+        return out_ready_fds;
+    }
+ 
+    errno = EOTHER;
+    return -1;
+}
+
diff --git a/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32fd.h b/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32fd.h
index 81aecce..04a3ad1 100644
--- a/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32fd.h
+++ b/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32fd.h
@@ -41,6 +41,7 @@ struct w32_io {
 };
 
 BOOL w32_io_is_blocking(struct w32_io*);
+BOOL w32_io_is_ioready(struct w32_io* pio, BOOL rd);
 
 int fd_table_initialize();
 int fd_table_add(struct w32_io*);
@@ -48,6 +49,8 @@ int fd_table_delete(struct w32_io*);
 
 int socketio_initialize();
 int socketio_done();
+BOOL socketio_is_ioready(struct w32_io* pio, BOOL rd);
+int socketio_start_asyncio(struct w32_io* pio, BOOL rd);
 struct w32_io* socketio_socket(int domain, int type, int protocol);
 struct w32_io* socketio_accept(struct w32_io* pio, struct sockaddr* addr, int* addrlen);
 int socketio_setsockopt(struct w32_io* pio, int level, int optname, const char* optval, int optlen);
@@ -57,22 +60,8 @@ int socketio_getpeername(struct w32_io* pio, struct sockaddr* name, int* namelen
 int socketio_listen(struct w32_io* pio, int backlog);
 int socketio_bind(struct w32_io* pio, const struct sockaddr *name, int namelen);
 int socketio_connect(struct w32_io* pio, const struct sockaddr* name, int namelen);
+int socketio_recv(struct w32_io* pio, void *buf, size_t len, int flags);
+int socketio_send(struct w32_io* pio, const void *buf, size_t len, int flags);
 int socketio_shutdown(struct w32_io* pio, int how);
 int socketio_close(struct w32_io* pio);
 
-/*non-network i/o*/
-int w32_pipe(int *pfds);
-int w32_open(const char *pathname, int flags, ...);
-int w32_wopen(const wchar_t *pathname, int flags, ...);
-int w32_creat(const char *pathname, int mode);
-int w32_read(int fd, void *dst, unsigned int max);
-int w32_write(int fd, const void *buf, unsigned int max);
-int w32_close(int fd);
-
-/*operations on fds*/
-int w32_ioctl(int d, int request, ...);
-int w32_select(int fds, fd_set* readfds, fd_set* writefds, fd_set* exceptfds, const struct timeval *timeout);
-int w32_fcntl(int fd, int cmd, ... /* arg */);
-int w32_dup(int oldfd);
-int w32_dup2(int oldfd, int newfd);
-
diff --git a/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32posix.h b/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32posix.h
index e3f5630..06ccca5 100644
--- a/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32posix.h
+++ b/contrib/win32/w32-posix-prototype/win32posix/win32posix/w32posix.h
@@ -53,6 +53,8 @@ void w32posix_done();
 #define listen w32_listen
 #define bind w32_bind
 #define connect w32_connect
+#define recv w32_recv
+#define send w32_send
 #define shutdown w32_shutdown
 int w32_socket(int domain, int type, int protocol);
 int w32_accept(int fd, struct sockaddr* addr, int* addrlen);
@@ -63,6 +65,8 @@ int w32_getpeername(int fd, struct sockaddr* name, int* namelen);
 int w32_listen(int fd, int backlog);
 int w32_bind(int fd, const struct sockaddr *name, int namelen);
 int w32_connect(int fd, const struct sockaddr* name, int namelen);
+int w32_recv(int fd, void *buf, size_t len, int flags);
+int w32_send(int fd, const void *buf, size_t len, int flags);
 int w32_shutdown(int fd, int how);
 
 /*non-network i/o*/