From 851ea656097ccfa2e114f1848b680bb294389891 Mon Sep 17 00:00:00 2001
From: Tau <tau@nowhere>
Date: Thu, 8 Nov 2018 15:57:01 -0500
Subject: [PATCH] util/clock.c: Add hook to prevent date/time changes

---
 util/clock.c     | 39 +++++++++++++++++++++++++++++++++++++++
 util/clock.h     |  3 +++
 util/meson.build |  2 ++
 3 files changed, 44 insertions(+)
 create mode 100644 util/clock.c
 create mode 100644 util/clock.h

diff --git a/util/clock.c b/util/clock.c
new file mode 100644
index 0000000..60e623a
--- /dev/null
+++ b/util/clock.c
@@ -0,0 +1,39 @@
+#include "hook/table.h"
+
+#include "util/dprintf.h"
+
+static BOOL WINAPI my_SetSystemTime(void *whatever);
+static BOOL WINAPI my_SetTimeZoneInformation(void *whatever);
+
+static const struct hook_symbol clock_hook_syms[] = {
+    {
+        .name   = "SetSystemTime",
+        .patch  = my_SetSystemTime,
+    }, {
+        .name   = "SetTimeZoneInformation",
+        .patch  = my_SetTimeZoneInformation,
+    }
+};
+
+void clock_hook_init(void)
+{
+    hook_table_apply(
+            NULL,
+            "kernel32.dll",
+            clock_hook_syms,
+            _countof(clock_hook_syms));
+}
+
+static BOOL WINAPI my_SetSystemTime(void *whatever)
+{
+    dprintf("Prevented application from screwing with the system clock\n");
+
+    return TRUE;
+}
+
+static BOOL WINAPI my_SetTimeZoneInformation(void *whatever)
+{
+    dprintf("Prevented application from screwing with the timezone\n");
+
+    return TRUE;
+}
diff --git a/util/clock.h b/util/clock.h
new file mode 100644
index 0000000..f3d242e
--- /dev/null
+++ b/util/clock.h
@@ -0,0 +1,3 @@
+#pragma once
+
+void clock_hook_init(void);
diff --git a/util/meson.build b/util/meson.build
index 0fa3470..7a8d6fa 100644
--- a/util/meson.build
+++ b/util/meson.build
@@ -7,6 +7,8 @@ util_lib = static_library(
         capnhook.get_variable('hook_dep'),
     ],
     sources : [
+        'clock.c',
+        'clock.h',
         'crc.c',
         'crc.h',
         'dprintf.c',