Added support for expandEnv, createDir & cpu_seconds on Windows

- expandEnv on Windows uses POCO C++ Libraries implementation of Glob
  - Paths of matched files are adjusted to preserve UNIX path
  separators for consistency with the rest of the code.
  - Minor change to code shared with other platforms that removes
  allocation of std::ifstream on the heap to check whether the file can
  be opened, which can be done with local stack variable that closes
  the file when out of scope.
- createDir uses _mkdir on Windows, which doesn't support configuring
  the new directory's mode.
- added public domain implementation of clock_gettime for clock_id
  CLOCK_PROCESS_CPUTIME_ID from mingw-w64's winpthreads to support
  cpu_seconds on Windows.
- Updated included headers to support compilation on Windows (using
  Visual C++)

src/utils/system.cc

@@ -19,6 +19,9 @@
 #include <string.h>
 #ifdef __OpenBSD__
 #include <glob.h>
+#elif defined(WIN32)
+#include "Poco/Glob.h"
+#include <algorithm>
 #else
 #include <wordexp.h>
 #endif
@@ -31,6 +34,7 @@
 #include <vector>
 
 #if defined _MSC_VER
+#include "src/compat/msvc.h"
 #include <direct.h>
 #elif defined __GNUC__
 #include <sys/types.h>
@@ -40,6 +44,36 @@
 #include "src/utils/system.h"
 #include "src/config.h"
 
+#ifdef WIN32
+
+// Public domain code from mingw-w64's winpthreads
+// https://sourceforge.net/p/mingw-w64/code/HEAD/tree/trunk/mingw-w64-libraries/winpthreads/src/clock.c
+// 
+
+#define CLOCK_PROCESS_CPUTIME_ID    2
+#define POW10_7                 10000000
+
+// NOTE: includes only CLOCK_PROCESS_CPUTIME_ID implementation, ignores clock_id argument
+static int clock_gettime(int clock_id, struct timespec *tp)
+{
+    unsigned __int64 t;
+    LARGE_INTEGER pf, pc;
+    union {
+        unsigned __int64 u64;
+        FILETIME ft;
+    }  ct, et, kt, ut;
+
+    if(0 == GetProcessTimes(GetCurrentProcess(), &ct.ft, &et.ft, &kt.ft, &ut.ft))
+        return -1;
+    t = kt.u64 + ut.u64;
+    tp->tv_sec = t / POW10_7;
+    tp->tv_nsec = ((int) (t % POW10_7)) * 100;
+
+    return 0;
+}
+
+#endif
+
 namespace modsecurity {
 namespace utils {
 
@@ -122,8 +156,16 @@ std::string get_path(const std::string& file) {
 
 std::list<std::string> expandEnv(const std::string& var, int flags) {
     std::list<std::string> vars;
-
-#ifdef __OpenBSD__
+#ifdef WIN32
+    // NOTE: align scopes with if & if in other versions
+    {
+        {
+            std::set<std::string> files;
+            Poco::Glob::glob(var, files);
+            for(auto file : files) {
+                std::replace(file.begin(), file.end(), '\\', '/');  // preserve unix-like paths
+                const char* exp[] = { file.c_str() };
+#elif defined(__OpenBSD__)
     glob_t p;
     if (glob(var.c_str(), flags, NULL, &p) == false) {
         if (p.gl_pathc) {
@@ -135,15 +177,13 @@ std::list<std::string> expandEnv(const std::string& var, int flags) {
         if (p.we_wordc) {
             for (char** exp = p.we_wordv; *exp; ++exp) {
 #endif
-                std::ifstream *iss = new std::ifstream(exp[0], std::ios::in);
-                if (iss->is_open()) {
-                    iss->close();
+                auto iss = std::ifstream(exp[0], std::ios::in);
+                if (iss.is_open())
                     vars.push_back(exp[0]);
-                }
-                delete iss;
             }
         }
-#ifdef __OpenBSD__
+#ifdef WIN32
+#elif defined(__OpenBSD__)
         globfree(&p);
 #else
         wordfree(&p);
@@ -153,7 +193,13 @@ std::list<std::string> expandEnv(const std::string& var, int flags) {
 }
 
 bool createDir(const std::string& dir, int mode, std::string *error) {
+#ifndef WIN32
     int ret = mkdir(dir.data(), mode);
+#else
+    if (dir == ".")
+        return true;
+    int ret = _mkdir(dir.c_str());
+#endif
     if (ret != 0 && errno != EEXIST) {
         error->assign("Not able to create directory: " + dir + ": " \
             + strerror(errno) + ".");