Set up hooks for GetProcAddress and LoadLibraryW

mercuryhook/dllmain.c

@@ -12,6 +12,7 @@
 #include "mercuryhook/config.h"
 #include "mercuryhook/io4.h"
 #include "mercuryhook/mercury-dll.h"
+#include "mercuryhook/elisabeth.h"
 
 #include "platform/platform.h"
 
@@ -75,6 +76,9 @@ static DWORD CALLBACK mercury_pre_startup(void)
         goto fail;
     }
 
+    /* Start elisabeth Hooks for the LED and IO Board DLLs */
+    elisabeth_hook_init();
+
     /* Initialize debug helpers */
 
     spike_hook_init(L".\\segatools.ini");

mercuryhook/elisabeth.c

@@ -0,0 +1,135 @@
+#include <windows.h>
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include "mercuryhook/elisabeth.h"
+
+#include "hook/table.h"
+
+#include "hooklib/dll.h"
+#include "hooklib/path.h"
+
+#include "util/dprintf.h"
+
+/* Hooks targeted DLLs dynamically loaded by elisabeth. */
+
+static void dll_hook_insert_hooks(HMODULE target);
+static HMODULE WINAPI my_LoadLibraryW(const wchar_t *name);
+static HMODULE (WINAPI *next_LoadLibraryW)(const wchar_t *name);
+static FARPROC WINAPI my_GetProcAddress(HMODULE hModule, const char *name);
+static FARPROC (WINAPI *next_GetProcAddress)(HMODULE hModule, const char *name);
+
+static const struct hook_symbol elisabeth_hooks[] = {
+    {
+        .name = "LoadLibraryW",
+        .patch = my_LoadLibraryW,
+        .link = (void **) &next_LoadLibraryW,
+    },
+    {
+        .name = "GetProcAddress",
+        .patch = my_GetProcAddress,
+        .link = (void **) &next_GetProcAddress
+    }
+};
+
+static const wchar_t *target_modules[] = {
+    L"USBIntLED.DLL",
+    L"ftd2XX.dll",
+};
+
+static const char *target_functions[] = {
+    "FT_Read",
+    "FT_Write",
+    "USBIntLED_Init",
+};
+
+static const size_t target_modules_len = _countof(target_modules);
+static const size_t target_functions_len = _countof(target_functions);
+
+void elisabeth_hook_init()
+{
+    dll_hook_insert_hooks(NULL);
+}
+
+static void dll_hook_insert_hooks(HMODULE target)
+{
+    hook_table_apply(
+            target,
+            "kernel32.dll",
+            elisabeth_hooks,
+            _countof(elisabeth_hooks));
+}
+
+static HMODULE WINAPI my_LoadLibraryW(const wchar_t *name)
+{
+    const wchar_t *name_end;
+    const wchar_t *target_module;
+    bool already_loaded;
+    HMODULE result;
+    size_t name_len;
+    size_t target_module_len;
+
+    if (name == NULL) {
+        SetLastError(ERROR_INVALID_PARAMETER);
+
+        return NULL;
+    }
+
+    // Check if the module is already loaded
+    already_loaded = GetModuleHandleW(name) != NULL;
+
+    // Must call the next handler so the DLL reference count is incremented
+    result = next_LoadLibraryW(name);
+
+    if (!already_loaded && result != NULL) {
+        name_len = wcslen(name);
+
+        for (size_t i = 0; i < target_modules_len; i++) {
+            target_module = target_modules[i];
+            target_module_len = wcslen(target_module);
+
+            // Check if the newly loaded library is at least the length of
+            // the name of the target module
+            if (name_len < target_module_len) {
+                continue;
+            }
+
+            name_end = &name[name_len - target_module_len];
+
+            // Check if the name of the newly loaded library is one of the
+            // modules the path hooks should be injected into
+            if (_wcsicmp(name_end, target_module) != 0) {
+                continue;
+            }
+
+            dprintf("Elisabeth: Loaded %S\n", target_module);
+
+            dll_hook_insert_hooks(result);
+            path_hook_insert_hooks(result);
+        }
+    }
+
+    return result;
+}
+
+FARPROC WINAPI my_GetProcAddress(HMODULE hModule, const char *name)
+{
+    uintptr_t ordinal;
+
+    FARPROC result = next_GetProcAddress(hModule, name);
+
+
+    for (size_t i = 0; i < target_functions_len; i++) {
+        ordinal = (uintptr_t) name;
+
+        if (ordinal > 0xFFFF) {
+            /* Import by name */
+            if (strcmp(target_functions[i], name) == 0)
+                dprintf("Elisabeth: GetProcAddress %s is %p\n", name, result);
+        }
+    }
+
+    return result;
+}

mercuryhook/elisabeth.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void elisabeth_hook_init();

mercuryhook/meson.build

@@ -24,6 +24,8 @@ shared_library(
         'io4.c',
         'io4.h',
         'mercury-dll.c',
-        'mercury-dll.h'
+        'mercury-dll.h',
+        'elisabeth.h',
+        'elisabeth.c'
     ],
 )