Add basic WINDNS interface

4 files changed, 273 insertions, 3 deletions

diff --git a/windns/src/windns/windns.cpp b/windns/src/windns/windns.cpp
new file mode 100644
index 0000000000..47d5d53b1f
--- /dev/null
+++ b/windns/src/windns/windns.cpp
@@ -0,0 +1,143 @@
+#include "stdafx.h"
+#include "windns.h"
+#include "windnscontext.h"
+#include <vector>
+#include <string>
+
+namespace
+{
+
+WinDnsErrorSink g_ErrorSink = nullptr;
+void *g_ErrorContext = nullptr;
+
+WinDnsContext *g_Context = nullptr;
+
+std::vector<std::wstring> MakeStringArray(const wchar_t **strings, uint32_t numStrings)
+{
+	std::vector<std::wstring> v;
+
+	while (numStrings--)
+	{
+		v.emplace_back(*strings++);
+	}
+
+	return v;
+}
+
+} // anonymous namespace
+
+WINDNS_LINKAGE
+bool
+WINDNS_API
+WinDns_Initialize(
+	WinDnsErrorSink errorSink,
+	void *errorContext
+)
+{
+	if (nullptr != g_Context)
+	{
+		return false;
+	}
+
+	g_ErrorSink = errorSink;
+	g_ErrorContext = errorContext;
+
+	try
+	{
+		g_Context = new WinDnsContext;
+	}
+	catch (std::exception &err)
+	{
+		if (nullptr != g_ErrorSink)
+		{
+			g_ErrorSink(err.what(), g_ErrorContext);
+		}
+
+		return false;
+	}
+	catch (...)
+	{
+		return false;
+	}
+
+	return true;
+}
+
+WINDNS_LINKAGE
+bool
+WINDNS_API
+WinDns_Deinitialize(
+)
+{
+	if (nullptr == g_Context)
+	{
+		return true;
+	}
+
+	delete g_Context;
+	g_Context = nullptr;
+
+	return true;
+}
+
+WINDNS_LINKAGE
+bool
+WINDNS_API
+WinDns_Set(
+	const wchar_t **servers,
+	uint32_t numServers
+)
+{
+	if (nullptr == g_Context)
+	{
+		return false;
+	}
+
+	try
+	{
+		return g_Context->set(MakeStringArray(servers, numServers), g_ErrorSink, g_ErrorContext);
+	}
+	catch (std::exception &err)
+	{
+		if (nullptr != g_ErrorSink)
+		{
+			g_ErrorSink(err.what(), g_ErrorContext);
+		}
+
+		return false;
+	}
+	catch (...)
+	{
+		return false;
+	}
+}
+
+WINDNS_LINKAGE
+bool
+WINDNS_API
+WinDns_Reset(
+)
+{
+	if (nullptr == g_Context)
+	{
+		return false;
+	}
+
+	try
+	{
+		return g_Context->reset();
+	}
+	catch (std::exception &err)
+	{
+		if (nullptr != g_ErrorSink)
+		{
+			g_ErrorSink(err.what(), g_ErrorContext);
+		}
+
+		return false;
+	}
+	catch (...)
+	{
+		return false;
+	}
+}
diff --git a/windns/src/windns/windns.h b/windns/src/windns/windns.h
index 450685d8a8..000913ad53 100644
--- a/windns/src/windns/windns.h
+++ b/windns/src/windns/windns.h
@@ -1,8 +1,80 @@
 #pragma once
+#include <cstdint>
 
-// simple model:
+//
+// WINDNS public API
+//
 
-bool StartEnforcingDns(const wchar_t *primaryServer);
+#ifdef WINDNS_EXPORTS
+#define WINDNS_LINKAGE __declspec(dllexport)
+#else
+#define WINDNS_LINKAGE __declspec(dllimport)
+#endif
 
-void StopEnforcingDns();
+#define WINDNS_API __stdcall
 
+///////////////////////////////////////////////////////////////////////////////
+// Functions
+///////////////////////////////////////////////////////////////////////////////
+
+typedef void (WINDNS_API *WinDnsErrorSink)(const char *errorMessage, void *context);
+
+//
+// WinDns_Initialize:
+//
+// Call this function once at startup, to acquire resources etc.
+//
+// The OPTIONAL error callback is remembered and used to report exceptions that
+// occur as a direct or indirect result of calling into WINDNS.
+//
+// (Recall that the monitoring provided by WINDNS is threaded.)
+//
+extern "C"
+WINDNS_LINKAGE
+bool
+WINDNS_API
+WinDns_Initialize(
+	WinDnsErrorSink errorSink,
+	void *errorContext
+);
+
+//
+// WinDns_Deinitialize:
+//
+// Call this function once before unloading WINDNS or exiting the process.
+//
+extern "C"
+WINDNS_LINKAGE
+bool
+WINDNS_API
+WinDns_Deinitialize(
+);
+
+//
+// WinDns_Set:
+//
+// Configure which DNS servers should be used and start enforcing these settings.
+//
+extern "C"
+WINDNS_LINKAGE
+bool
+WINDNS_API
+WinDns_Set(
+	const wchar_t **servers,
+	uint32_t numServers
+);
+
+//
+// Windns_Reset:
+//
+// Revert server settings to what they were before calling WinDns_Set.
+//
+// (Also taking into account external changes to DNS settings that have occurred
+// during the period of enforcing specific settings.)
+//
+extern "C"
+WINDNS_LINKAGE
+bool
+WINDNS_API
+WinDns_Reset(
+);
diff --git a/windns/src/windns/windnscontext.cpp b/windns/src/windns/windnscontext.cpp
new file mode 100644
index 0000000000..404c16f5e1
--- /dev/null
+++ b/windns/src/windns/windnscontext.cpp
@@ -0,0 +1,28 @@
+#include "stdafx.h"
+#include "windnscontext.h"
+#include "wmi/connection.h"
+#include <process.h>
+
+WinDnsContext::WinDnsContext()
+{
+	// Create WMI connection and keep it around?
+}
+
+bool WinDnsContext::set(const std::vector<std::wstring> &servers, WinDnsErrorSink errorSink, void *errorContext)
+{
+	ThreadArguments args;
+
+	args.errorSink = errorSink;
+	args.errorContext = errorContext;
+
+//	_beginthreadex(nullptr, 0, )
+
+
+
+	return false;
+}
+
+bool WinDnsContext::reset()
+{
+	return false;
+}
diff --git a/windns/src/windns/windnscontext.h b/windns/src/windns/windnscontext.h
new file mode 100644
index 0000000000..57d00ff530
--- /dev/null
+++ b/windns/src/windns/windnscontext.h
@@ -0,0 +1,27 @@
+#pragma once
+
+#include "windns.h"
+#include <vector>
+#include <string>
+
+class WinDnsContext
+{
+public:
+
+	WinDnsContext();
+
+	bool set(const std::vector<std::wstring> &servers, WinDnsErrorSink errorSink, void *errorContext);
+	bool reset();
+
+//	static unsigned monitoringThread()
+
+private:
+
+	struct ThreadArguments
+	{
+		WinDnsContext *instance;
+		WinDnsErrorSink errorSink;
+		void *errorContext;
+	};
+
+};