include/compat: Add win32 compatibility layer

Windows provides socket and other related structures that are mostly
following the Posix standards, but using different headers.

Rather than adding lots of platform checks and require future commits
to do so as well, we're adding headers with the same names, which
in turn include the required Windows headers.

In a few cases, some functions declared by unistd.h are actually
defined by different Windows headers, so we'll need additional includes.

One thing to note here is that boost requires us to include aio.hpp
before the Windows socket headers.

Signed-off-by: Lucian Petrut <lpetrut@cloudbasesolutions.com>

CMakeLists.txt

@@ -69,6 +69,13 @@ include_directories(
   ${PROJECT_BINARY_DIR}/src/include
   ${PROJECT_SOURCE_DIR}/src)
 
+if(WIN32)
+  include_directories(
+  ${PROJECT_SOURCE_DIR}/src/include/win32)
+  # Boost complains if winsock2.h (or windows.h) is included before asio.hpp.
+  add_definitions(-include winsock_wrapper.h)
+endif()
+
 if(OFED_PREFIX)
   include_directories(SYSTEM ${OFED_PREFIX}/include)
   link_directories(${OFED_PREFIX}/lib)

src/common/admin_socket_client.cc

@@ -16,6 +16,7 @@
 #include <fcntl.h>
 #include <sys/socket.h>
 #include <sys/un.h>
+#include <unistd.h>
 
 #include "common/admin_socket.h"
 #include "common/errno.h"

src/common/hostname.cc

@@ -16,6 +16,8 @@
 
 #include <unistd.h>
 
+#include "include/compat.h"
+
 std::string ceph_get_hostname()
 {
   // are we in a container?  if so we would prefer the *real* hostname.

src/include/compat.h

@@ -206,6 +206,8 @@ char *ceph_strerror_r(int errnum, char *buf, size_t buflen);
 
 #if defined(_WIN32)
 
+#include "include/win32/winsock_compat.h"
+
 typedef _sigset_t sigset_t;
 
 typedef int uid_t;

src/include/win32/arpa/inet.h

@@ -0,0 +1 @@
+#include "winsock_compat.h"

src/include/win32/netdb.h

@@ -0,0 +1 @@
+#include "winsock_compat.h"

src/include/win32/netinet/in.h

@@ -0,0 +1 @@
+#include "winsock_compat.h"

src/include/win32/poll.h

@@ -0,0 +1 @@
+#include "winsock_compat.h"

src/include/win32/sys/errno.h

@@ -0,0 +1 @@
+#include <errno.h>

src/include/win32/sys/socket.h

@@ -0,0 +1 @@
+#include "winsock_compat.h"

src/include/win32/sys/un.h

@@ -0,0 +1 @@
+#include "include/win32/winsock_compat.h"

src/include/win32/winsock_compat.h

@@ -0,0 +1,39 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (c) 2019 SUSE LLC
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#ifndef WINSOCK_COMPAT_H
+#define WINSOCK_COMPAT_H 1
+
+#include "winsock_wrapper.h"
+
+#ifndef poll
+#define poll WSAPoll
+#endif
+
+// afunix.h is available starting with Windows SDK 17063. Still, it wasn't
+// picked up by mingw yet, for which reason we're going to define sockaddr_un
+// here.
+#ifndef _AFUNIX_
+#define UNIX_PATH_MAX 108
+
+typedef struct sockaddr_un
+{
+     ADDRESS_FAMILY sun_family;     /* AF_UNIX */
+     char sun_path[UNIX_PATH_MAX];  /* pathname */
+} SOCKADDR_UN, *PSOCKADDR_UN;
+
+#define SIO_AF_UNIX_GETPEERPID _WSAIOR(IOC_VENDOR, 256)
+#endif /* _AFUNIX */
+
+#endif /* WINSOCK_COMPAT_H */

src/include/win32/winsock_wrapper.h

@@ -0,0 +1,27 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (c) 2020 SUSE LLC
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#ifndef WINSOCK_WRAPPER_H
+#define WINSOCK_WRAPPER_H 1
+
+#ifdef __cplusplus
+// Boost complains if winsock2.h (or windows.h) is included before asio.hpp.
+#include <boost/asio.hpp>
+#endif
+
+#include <winsock2.h>
+#include <ws2ipdef.h>
+#include <ws2tcpip.h>
+
+#endif /* WINSOCK_WRAPPER_H */