From 0d3fa54316fe24e041480026bf75b5f6668ae220 Mon Sep 17 00:00:00 2001
From: Will Xyen <willxinc@users.noreply.github.com>
Date: Sat, 4 Apr 2020 23:37:10 -0700
Subject: [PATCH] launcher: Add before-hook support

Required to hook certain things that happen on module load / avs boot:
 - network adapter hooking for avs
 - envvar setting

Note: the logging facilities are NOT setup yet at this point
so these hooks cannot use avs for logging
---
 src/main/launcher/main.c    | 52 +++++++++++++++++++++----------------
 src/main/launcher/options.c | 14 ++++++++++
 src/main/launcher/options.h |  1 +
 3 files changed, 44 insertions(+), 23 deletions(-)

diff --git a/src/main/launcher/main.c b/src/main/launcher/main.c
index 5f6f469..5330504 100644
--- a/src/main/launcher/main.c
+++ b/src/main/launcher/main.c
@@ -93,10 +93,34 @@ static AVS_LOG_WRITER(log_callback, chars, nchars, ctx)
     free(utf16);
 }
 
+static void load_hook_dlls(struct array* hook_dlls) {
+    const char *hook_dll;
+
+    for (size_t i = 0; i < hook_dlls->nitems; i++) {
+        hook_dll = *array_item(char *, hook_dlls, i);
+
+        if (LoadLibraryA(hook_dll) == NULL) {
+            LPSTR buffer;
+
+            FormatMessageA(
+                FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
+                    FORMAT_MESSAGE_IGNORE_INSERTS,
+                NULL,
+                GetLastError(),
+                MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                (LPSTR) &buffer,
+                0,
+                NULL);
+
+            log_fatal("%s: Failed to load hook DLL: %s", hook_dll, buffer);
+
+            LocalFree(buffer);
+        }
+    }
+}
+
 int main(int argc, const char **argv)
 {
-    int i;
-    const char *hook_dll;
     bool ok;
     HANDLE logfile;
 
@@ -170,6 +194,8 @@ int main(int argc, const char **argv)
         log_fatal("%s: /config missing", options.avs_config_path);
     }
 
+    load_hook_dlls(&options.before_hook_dlls);
+
     avs_context_init(
         avs_config_root,
         options.avs_heap_size,
@@ -188,27 +214,7 @@ int main(int argc, const char **argv)
 
     /* Load hook DLLs */
 
-    for (i = 0; i < options.hook_dlls.nitems; i++) {
-        hook_dll = *array_item(char *, &options.hook_dlls, i);
-
-        if (LoadLibraryA(hook_dll) == NULL) {
-            LPSTR buffer;
-
-            FormatMessageA(
-                FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
-                    FORMAT_MESSAGE_IGNORE_INSERTS,
-                NULL,
-                GetLastError(),
-                MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-                (LPSTR) &buffer,
-                0,
-                NULL);
-
-            log_fatal("%s: Failed to load hook DLL: %s", hook_dll, buffer);
-
-            LocalFree(buffer);
-        }
-    }
+    load_hook_dlls(&options.hook_dlls);
 
     /* Inject GetModuleHandle hooks */
 
diff --git a/src/main/launcher/options.c b/src/main/launcher/options.c
index 11c1b51..91be9c0 100644
--- a/src/main/launcher/options.c
+++ b/src/main/launcher/options.c
@@ -23,6 +23,7 @@ void options_init(struct options *options)
     options->logfile = NULL;
     options->remote_debugger = false;
     array_init(&options->hook_dlls);
+    array_init(&options->before_hook_dlls);
 }
 
 bool options_read_cmdline(struct options *options, int argc, const char **argv)
@@ -115,6 +116,16 @@ bool options_read_cmdline(struct options *options, int argc, const char **argv)
 
                     break;
 
+                case 'B':
+                    if (i + 1 >= argc) {
+                        return false;
+                    }
+
+                    *array_append(const char *, &options->before_hook_dlls) =
+                        argv[++i];
+
+                    break;
+
                 case 'Y':
                     if (i + 1 >= argc) {
                         return false;
@@ -170,6 +181,8 @@ void options_print_usage(void)
         "       -R [pcbid]      Specify Soft ID (default: use ea3 config)\n"
         "       -K [filename]   Load hook DLL (can be specified multiple "
         "times)\n"
+        "       -B [filename]   Load pre-hook DLL loaded before avs boot "
+        "(can be specified multiple times)\n"
         "       -Y [filename]   Log to a file in addition to the console\n"
         "       -D              Halt the launcher before bootstrapping AVS "
         "until a"
@@ -179,4 +192,5 @@ void options_print_usage(void)
 void options_fini(struct options *options)
 {
     array_fini(&options->hook_dlls);
+    array_fini(&options->before_hook_dlls);
 }
diff --git a/src/main/launcher/options.h b/src/main/launcher/options.h
index 30ebe5b..b7f0c01 100644
--- a/src/main/launcher/options.h
+++ b/src/main/launcher/options.h
@@ -17,6 +17,7 @@ struct options {
     const char *module;
     const char *logfile;
     struct array hook_dlls;
+    struct array before_hook_dlls;
     bool remote_debugger;
 };