From df5aa13029153bf9711e202cf4e8a6d3ff6f4d4a Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Tue, 28 Nov 2017 11:13:46 +1100
Subject: [PATCH] [host] Added a crash handler to write out mini dumps

---
 host/CrashHandler.cpp | 79 +++++++++++++++++++++++++++++++++++++++++++
 host/CrashHandler.h   | 29 ++++++++++++++++
 host/main.cpp         |  3 ++
 3 files changed, 111 insertions(+)
 create mode 100644 host/CrashHandler.cpp
 create mode 100644 host/CrashHandler.h

diff --git a/host/CrashHandler.cpp b/host/CrashHandler.cpp
new file mode 100644
index 00000000..4ba819c2
--- /dev/null
+++ b/host/CrashHandler.cpp
@@ -0,0 +1,79 @@
+/*
+KVMGFX Client - A KVM Client for VGA Passthrough
+Copyright (C) 2017 Geoffrey McRae <geoff@hostfission.com>
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; either version 2 of the License, or (at your option) any later
+version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include "CrashHandler.h"
+
+typedef BOOL (WINAPI * PMiniDumpWriteDump)(
+    _In_ HANDLE hProcess,
+    _In_ DWORD ProcessId,
+    _In_ HANDLE hFile,
+    _In_ MINIDUMP_TYPE DumpType,
+    _In_opt_ PMINIDUMP_EXCEPTION_INFORMATION ExceptionParam,
+    _In_opt_ PMINIDUMP_USER_STREAM_INFORMATION UserStreamParam,
+    _In_opt_ PMINIDUMP_CALLBACK_INFORMATION CallbackParam
+  );
+
+void CrashHandler::Initialize()
+{
+  SetUnhandledExceptionFilter(CrashHandler::ExceptionFilter);
+}
+
+LONG WINAPI CrashHandler::ExceptionFilter(struct _EXCEPTION_POINTERS * apExceptionInfo)
+{
+  HMODULE lib;
+  PMiniDumpWriteDump fn_MiniDumpWriteDump;
+
+  lib = LoadLibraryA("dbghelp.dll");
+  if (!lib)
+    return EXCEPTION_CONTINUE_SEARCH;
+
+  fn_MiniDumpWriteDump = (PMiniDumpWriteDump)GetProcAddress(lib, "MiniDumpWriteDump");
+  if (!fn_MiniDumpWriteDump)
+    return EXCEPTION_CONTINUE_SEARCH;
+
+  HANDLE hFile = CreateFileA(
+    "kvm-ivshmem-host.dump",
+    GENERIC_WRITE,
+    FILE_SHARE_WRITE,
+    NULL,
+    CREATE_ALWAYS,
+    FILE_ATTRIBUTE_NORMAL,
+    NULL
+  );
+
+  if (hFile == INVALID_HANDLE_VALUE)
+    return EXCEPTION_CONTINUE_SEARCH;
+
+  _MINIDUMP_EXCEPTION_INFORMATION info;
+  info.ThreadId          = GetCurrentThreadId();
+  info.ExceptionPointers = apExceptionInfo;
+  info.ClientPointers    = FALSE;
+
+  fn_MiniDumpWriteDump(
+    GetCurrentProcess(),
+    GetCurrentProcessId(),
+    hFile,
+    MiniDumpNormal,
+    &info,
+    NULL,
+    NULL
+  );
+
+  CloseHandle(hFile);
+  return EXCEPTION_CONTINUE_SEARCH;
+}
\ No newline at end of file
diff --git a/host/CrashHandler.h b/host/CrashHandler.h
new file mode 100644
index 00000000..eb984ce1
--- /dev/null
+++ b/host/CrashHandler.h
@@ -0,0 +1,29 @@
+/*
+KVMGFX Client - A KVM Client for VGA Passthrough
+Copyright (C) 2017 Geoffrey McRae <geoff@hostfission.com>
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; either version 2 of the License, or (at your option) any later
+version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#pragma once
+#include <Windows.h>
+#include <DbgHelp.h>
+
+class CrashHandler
+{
+public:
+  static void Initialize();
+private:
+  static LONG WINAPI ExceptionFilter(struct _EXCEPTION_POINTERS * apExceptionInfo);
+};
\ No newline at end of file
diff --git a/host/main.cpp b/host/main.cpp
index b5d75427..b24d47c4 100644
--- a/host/main.cpp
+++ b/host/main.cpp
@@ -22,6 +22,7 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #include "common\debug.h"
 #include "vendor\getopt\getopt.h"
 
+#include "CrashHandler.h"
 #include "CaptureFactory.h"
 #include "Service.h"
 
@@ -47,6 +48,8 @@ struct StartupArgs
 
 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdParam, int iCmdShow)
 {
+  CrashHandler::Initialize();
+
   struct StartupArgs args;
   ZeroMemory(&args, sizeof(struct StartupArgs));
   int ret = parseArgs(args);