`strings.h` and `resolv.h` are not available on MSVC, and some POSIX functions are renamed or deprecated

For all of those missing/deprecated POSIX functions, we just add a macro mapping to the _underscored version of MSVC.

libvncclient/rfbproto.c

@@ -53,7 +53,12 @@
 #endif
 #include <jpeglib.h>
 #endif
+
+#ifndef _MSC_VER
+/* Strings.h is not available in MSVC */
 #include <strings.h>
+#endif
+
 #include <stdarg.h>
 #include <time.h>
 
@@ -65,7 +70,7 @@
 #include "tls.h"
 
 #ifdef _MSC_VER
-#  define snprintf _snprintf
+#  define snprintf _snprintf /* MSVC went straight to the underscored syntax */
 #endif
 
 /*

libvncclient/vncviewer.c

@@ -26,6 +26,10 @@
 #include <winsock2.h>
 #endif
 
+#ifdef _MSC_VER
+#define strdup _strdup /* Prevent POSIX deprecation warnings */
+#endif
+
 #ifdef __STRICT_ANSI__
 #define _BSD_SOURCE
 #define _POSIX_SOURCE

libvncserver/rfbserver.c

@@ -83,6 +83,13 @@
 #include "rfbssl.h"
 #endif
 
+#ifdef _MSC_VER
+#define snprintf _snprintf /* Missing in MSVC */
+/* Prevent POSIX deprecation warnings */
+#define close _close
+#define strdup _strdup 
+#endif
+
 #ifdef __MINGW32__
 static int compat_mkdir(const char *path, int mode)
 {

libvncserver/sockets.c

@@ -109,6 +109,10 @@ int deny_severity=LOG_WARNING;
 #define closesocket close
 #endif
 
+#ifdef _MSC_VER
+#define snprintf _snprintf /* Missing in MSVC */
+#endif
+
 int rfbMaxClientWait = 20000;   /* time (ms) after which we decide client has
                                    gone away - needed to stop us hanging */
 

libvncserver/stats.c

@@ -26,6 +26,10 @@
 
 #include <rfb/rfb.h>
 
+#ifdef _MSC_VER
+#define snprintf _snprintf /* Missing in MSVC */
+#endif
+
 char *messageNameServer2Client(uint32_t type, char *buf, int len);
 char *messageNameClient2Server(uint32_t type, char *buf, int len);
 char *encodingName(uint32_t enc, char *buf, int len);

libvncserver/websockets.c

@@ -31,10 +31,13 @@
 #endif
 
 #include <rfb/rfb.h>
-#include <resolv.h> /* __b64_ntop */
 /* errno */
 #include <errno.h>
 
+#ifndef _MSC_VER
+#include <resolv.h> /* __b64_ntop */
+#endif
+
 #ifdef LIBVNCSERVER_HAVE_ENDIAN_H
 #include <endian.h>
 #elif LIBVNCSERVER_HAVE_SYS_ENDIAN_H