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authorWillian Henrique <wsimanbrazil@yahoo.com.br>2023-11-26 17:46:45 -0300
committerMichael Smith <mikesmiffy128@gmail.com>2023-11-26 21:35:57 +0000
commit44d805746e27c58f906ba73f541abcb363323a75 (patch)
tree0172780432ab3c4b8c3fd7d186daa29fca648525 /src/ac.c
parent852ff29088e08a9f1673a070f5ff151e23e393ec (diff)
Hook Key_Event instead of DispatchInputEvent in AC
This fixes a crash in later L4D2 versions caused by the fact we were unknowingly hooking Key_Event already. Now we hook it all the time on purpose.
Diffstat (limited to 'src/ac.c')
-rw-r--r--src/ac.c57
1 files changed, 33 insertions, 24 deletions
diff --git a/src/ac.c b/src/ac.c
index be7fbba..537ccfc 100644
--- a/src/ac.c
+++ b/src/ac.c
@@ -1,6 +1,6 @@
/*
* Copyright © 2023 Michael Smith <mikesmiffy128@gmail.com>
- * Copyright © 2022 Willian Henrique <wsimanbrazil@yahoo.com.br>
+ * Copyright © 2023 Willian Henrique <wsimanbrazil@yahoo.com.br>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
@@ -277,10 +277,9 @@ struct inputevent {
DECL_VFUNC_DYN(void, GetDesktopResolution, int *, int *)
DECL_VFUNC_DYN(void, DispatchAllStoredGameMessages)
-typedef void (*VCALLCONV DispatchInputEvent_func)(void *, struct inputevent *);
-static DispatchInputEvent_func orig_DispatchInputEvent;
-static void VCALLCONV hook_DispatchInputEvent(void *this,
- struct inputevent *ev) {
+typedef void (*Key_Event_func)(struct inputevent *);
+static Key_Event_func orig_Key_Event;
+static void hook_Key_Event(struct inputevent *ev) {
//const char *desc[] = {"DOWN", "UP", "DBL"};
//const char desclen[] = {4, 2, 3};
switch (ev->type) {
@@ -297,17 +296,17 @@ static void VCALLCONV hook_DispatchInputEvent(void *this,
// msg_putssz5(p++, desclen[idx]);
// memcpy(p, desc[idx], desclen[idx]); p += desclen[idx];
}
- orig_DispatchInputEvent(this, ev);
+ orig_Key_Event(ev);
}
-static bool find_DispatchInputEvent(void) {
+static bool find_Key_Event(void) {
#ifdef _WIN32
// Crazy pointer-chasing path to get to DispatchInputEvent:
// IGameUIFuncs interface
// -> CGameUIFuncs::GetDesktopResolution vfunc
// -> IGame/CGame (first mov into ECX)
// -> CGame::DispatchAllStoredGameMessages vfunc
- // -> DispatchInputEvent (first call instruction)
+ // -> First call instruction (either DispatchInputEvent or Key_Event)
void *gameuifuncs = factory_engine("VENGINE_GAMEUIFUNCS_VERSION005", 0);
if (!gameuifuncs) {
errmsg_errorx("couldn't get engine game UI interface");
@@ -328,17 +327,27 @@ static bool find_DispatchInputEvent(void) {
ok: insns = (const uchar *)VFUNC(cgame, DispatchAllStoredGameMessages);
for (const uchar *p = insns; p - insns < 128;) {
if (p[0] == X86_CALL) {
- orig_DispatchInputEvent = (DispatchInputEvent_func)(p + 5 +
- mem_loadoffset(p + 1));
- // Note: we could go further and dig HandleEngineKey from Key_Event,
- // but it seems like Key_Event isn't directly called from
- // DispatchInputEvent in L4D2 (or has a much different structure,
- // requiring another function call to lead to HandleEngineKey).
- return true;
+ orig_Key_Event = (Key_Event_func)(p + 5 + mem_loadoffset(p + 1));
+ goto ok2;
}
- NEXT_INSN(p, "DispatchInputEvent function");
+ NEXT_INSN(p, "DispatchInputEvent/Key_Event function");
}
- errmsg_errorx("couldn't find DispatchInputEvent function");
+ errmsg_errorx("couldn't find DispatchInputEvent/Key_Event function");
+ return false;
+ok2:
+ insns = (const uchar *)orig_Key_Event;
+ // Depending on compiler inlining decisions, the function we just found can
+ // be either DispatchInputEvent or Key_Event. If another CALL is found at
+ // the start of this function, that means that we actually found
+ // DispatchInputEvent and this CALL points to Key_Event.
+ for (const uchar *p = insns; p - insns < 32;) {
+ if (p[0] == X86_CALL) {
+ orig_Key_Event = (Key_Event_func)(p + 5 + mem_loadoffset(p + 1));
+ break;
+ }
+ NEXT_INSN(p, "Key_Event function");
+ }
+ return true;
#else
#warning TODO(linux): more find-y stuff
#endif
@@ -366,11 +375,11 @@ PREINIT {
}
INIT {
- if (!find_DispatchInputEvent()) return false;
- orig_DispatchInputEvent = (DispatchInputEvent_func)hook_inline(
- (void *)orig_DispatchInputEvent, (void *)&hook_DispatchInputEvent);
- if (!orig_DispatchInputEvent) {
- errmsg_errorsys("couldn't hook DispatchInputEvent function");
+ if (!find_Key_Event()) return false;
+ orig_Key_Event = (Key_Event_func)hook_inline((void *)orig_Key_Event,
+ (void *)&hook_Key_Event);
+ if (!orig_Key_Event) {
+ errmsg_errorsys("couldn't hook Key_Event function");
return false;
}
@@ -423,7 +432,7 @@ e2: VirtualFree(keybox, 4096, MEM_RELEASE);
#else
e: munmap(keybox, 4096);
#endif
- unhook_inline((void *)orig_DispatchInputEvent);
+ unhook_inline((void *)orig_Key_Event);
return false;
}
@@ -438,7 +447,7 @@ END {
munmap(keybox, 4096);
// TODO(linux): call other cleanup things
#endif
- unhook_inline((void *)orig_DispatchInputEvent);
+ unhook_inline((void *)orig_Key_Event);
}
// vi: sw=4 ts=4 noet tw=80 cc=80