Add alias management plus input filtering skeleton

Some of the alias stuff was kind of stolen from earlier figuring-out
Bill did. More Bill code is also on the way. :^)

6 files changed, 337 insertions, 6 deletions

diff --git a/src/ac.c b/src/ac.c
new file mode 100644
index 0000000..f5451de
--- /dev/null
+++ b/src/ac.c
@@ -0,0 +1,150 @@
+/*
+ * Copyright © 2022 Michael Smith <mikesmiffy128@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include "con_.h"
+#include "hook.h"
+#include "engineapi.h"
+#include "errmsg.h"
+#include "intdefs.h"
+#include "mem.h"
+#include "os.h"
+#include "ppmagic.h"
+
+static bool lockdown = false;
+
+#ifdef _WIN32
+
+static void *gamewin, *inhookwin, *inhookthr;
+static ulong inhooktid;
+
+// UINT_PTR is a **stupid** typedef, but whatever.
+static ssize __stdcall kproc(int code, UINT_PTR wp, ssize lp) {
+	KBDLLHOOKSTRUCT *data = (KBDLLHOOKSTRUCT *)lp;
+	if (lockdown && data->flags & LLKHF_INJECTED &&
+			GetForegroundWindow() == gamewin) {
+		return 1;
+	}
+	return CallNextHookEx(0, code, wp, lp);
+}
+
+static ssize __stdcall mproc(int code, UINT_PTR wp, ssize lp) {
+	MSLLHOOKSTRUCT *data = (MSLLHOOKSTRUCT *)lp;
+	if (lockdown && data->flags & LLMHF_INJECTED &&
+			GetForegroundWindow() == gamewin) {
+		return 1;
+	}
+	return CallNextHookEx(0, code, wp, lp);
+}
+
+// this is its own thread to meet the strict timing deadline, otherwise the
+// hook gets silently removed. plus, we don't wanna incur latency anyway.
+static ulong __stdcall inhookthrmain(void *unused) {
+	if (!SetWindowsHookExW(WH_KEYBOARD_LL, &kproc, 0, 0) ||
+			!SetWindowsHookExW(WH_MOUSE_LL, &mproc, 0, 0)) {
+		// intentionally vague message
+		con_warn("sst: RTA mode is unavailable due to an error\n");
+		return -1;
+	}
+	MSG m; int ret;
+	while ((ret = GetMessageW(&m, inhookwin, 0, 0)) > 0) DispatchMessage(&m);
+	if (ret == -1) {
+		// XXX: if this ever happens, it's a disaster! users might not notice
+		// their run just dying all of a sudden. with any luck it won't matter
+		// in practice but... this kind of sucks.
+		con_warn("** sst: ERROR in message loop, abandoning RTA mode! **");
+	}
+	return ret;
+}
+
+static bool win32_init(void) {
+	gamewin = FindWindowW(L"Valve001", 0);
+	if (!gamewin) {
+		errmsg_errorsys("failed to get game window handle");
+		return false;
+	}
+	return true;
+}
+
+static void inhook_start(void) {
+	inhookwin = CreateWindowW(L"sst-eventloop", L"sst-eventloop",
+			WS_DISABLED, 0, 0, 0, 0, HWND_MESSAGE, 0, 0, 0);
+	inhookthr = CreateThread(0, 0, &inhookthrmain, 0, 0, &inhooktid);
+}
+
+// TODO(rta): run this check every tick (or at least X amount of time)
+static void inhook_check(void) {
+	if (WaitForSingleObject(inhookthr, 0) == WAIT_OBJECT_0) {
+		ulong status;
+		GetExitCodeThread(inhookthr, &status);
+		if (status != 0) {
+			// TODO(rta): stop demos, and stuff.
+			lockdown = false;
+		}
+	}
+}
+
+static void inhook_stop(void) {
+	PostThreadMessageW(inhooktid, WM_QUIT, 0, 0);
+	if (WaitForSingleObject(inhookthr, INFINITE) == WAIT_FAILED) {
+		errmsg_warnsys("couldn't wait for thread, status unknown");
+		// XXX: now what!?
+	}
+}
+
+#else
+
+// TODO(linux): do some stuff, I guess...
+
+#endif
+
+// TODO(rta): call these functions as part of the run lifecycle
+
+static void startlockdown(void) {
+	if (lockdown) return;
+#ifdef _WIN32
+	inhook_start();
+#endif
+	// FIXME: should really have some semaphore to make sure inhook thread got
+	// going okay...
+	lockdown = true;
+	// TODO(rta): start demos, etc
+}
+
+static void endlockdown(void) {
+	if (!lockdown) return;
+#ifdef _WIN32
+	inhook_stop();
+#endif
+	lockdown = false;
+}
+
+bool ac_init(void) {
+#if defined(_WIN32)
+	if (!win32_init()) return false;
+#elif defined(__linux__)
+	// TODO(linux): call init things
+#endif
+	return true;
+}
+
+void ac_end(void) {
+	endlockdown();
+}
+
+// vi: sw=4 ts=4 noet tw=80 cc=80
diff --git a/src/ac.h b/src/ac.h
new file mode 100644
index 0000000..638b01f
--- /dev/null
+++ b/src/ac.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright © 2022 Michael Smith <mikesmiffy128@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef INC_AC_H
+#define INC_AC_H
+
+#include <stdbool.h>
+
+bool ac_init(void);
+void ac_end(void);
+
+#endif
+
+// vi: sw=4 ts=4 noet tw=80 cc=80
diff --git a/src/alias.c b/src/alias.c
new file mode 100644
index 0000000..7db5907
--- /dev/null
+++ b/src/alias.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright © 2022 Michael Smith <mikesmiffy128@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdbool.h>
+#include <string.h>
+
+#include "alias.h"
+#include "con_.h"
+#include "dbg.h"
+#include "errmsg.h"
+#include "extmalloc.h"
+#include "mem.h"
+#include "x86.h"
+
+struct alias **_alias_head;
+
+void alias_rm(const char *name) {
+	for (struct alias **p = _alias_head; *p; p = &(*p)->next) {
+		if (!strcmp((*p)->name, name)) {
+			struct alias *next = (*p)->next;
+			extfree((*p)->value); extfree(*p);
+			*p = next;
+			return;
+		}
+	}
+}
+
+DEF_CCMD_HERE(sst_alias_remove, "Remove a command alias", 0) {
+	if (cmd->argc != 2) {
+		con_warn("usage: sst_alias_remove name");
+		return;
+	}
+	if (strlen(cmd->argv[1]) > 31) {
+		con_warn("invalid alias name (too long)");
+		return;
+	}
+	alias_rm(cmd->argv[1]);
+}
+
+void alias_nuke(void) {
+	for (struct alias *p = alias_head; p;) {
+		struct alias *next = p->next;
+		extfree(p->value); extfree(p);
+		p = next;
+	}
+	alias_head = 0;
+}
+
+DEF_CCMD_HERE(sst_alias_clear, "Remove all command aliases", 0) {
+	if (cmd->argc != 1) {
+		con_warn("usage: sst_alias_clear");
+		return;
+	}
+	alias_nuke();
+}
+
+// XXX: same as in demorec, might want some abstraction for this
+#define NEXT_INSN(p, tgt) do { \
+	int _len = x86_len(p); \
+	if (_len == -1) { \
+		errmsg_errorx("unknown or invalid instruction looking for %s", tgt); \
+		return false; \
+	} \
+	(p) += _len; \
+} while (0)
+
+static bool find_alias_head(con_cmdcb alias_cb) {
+#ifdef _WIN32
+	for (uchar *p = (uchar *)alias_cb; p - (uchar *)alias_cb < 64;) {
+		// alias command with no args calls ConMsg() then loads the head pointer
+		// that asm looks like: call <reg>; mov <reg>, dword ptr [x]
+		// (we don't care about the exact registers)
+		if (p[0] == X86_MISCMW && (p[1] & 0xF0) == 0xD0 &&
+				p[2] == X86_MOVRMW && (p[3] & 0xC7) == 0x05) {
+			_alias_head = mem_loadptr(p + 4);
+			return true;
+		}
+		NEXT_INSN(p, "load of alias list");
+	}
+#else
+#warning TODO(linux): check whether linux is equivalent!
+#endif
+	return false;
+}
+
+bool alias_init(void) {
+	struct con_cmd *cmd_alias = con_findcmd("alias");
+	if (!cmd_alias) {
+		errmsg_warnx("couldn't find \"alias\" command");
+		return false;
+	}
+	if (!find_alias_head(con_getcmdcb(cmd_alias))) {
+		errmsg_warnx("couldn't find alias list");
+		return false;
+	};
+	return true;
+}
+
+// vi: sw=4 ts=4 noet tw=80 cc=80
diff --git a/src/alias.h b/src/alias.h
new file mode 100644
index 0000000..3e417d9
--- /dev/null
+++ b/src/alias.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright © 2022 Michael Smith <mikesmiffy128@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef INC_ALIAS_H
+#define INC_ALIAS_H
+
+#include <stdbool.h>
+
+struct alias {
+	struct alias *next;
+	char name[32]; // TIL this has a hard limit :^)
+	char *value;
+};
+extern struct alias **_alias_head;
+#define alias_head (*_alias_head) // act as a global
+
+void alias_rm(const char *name);
+void alias_nuke(void);
+
+bool alias_init(void);
+
+#endif
+
+// vi: sw=4 ts=4 noet tw=80 cc=80
diff --git a/src/demorec.c b/src/demorec.c
index 156e7c6..a0c85a1 100644
--- a/src/demorec.c
+++ b/src/demorec.c
@@ -165,7 +165,7 @@ static void hook_stop_cb(const struct con_cmdargs *args) {
 
 // This finds the "demorecorder" global variable (the engine-wide CDemoRecorder
 // instance).
-static inline bool find_demorecorder(struct con_cmd *cmd_stop) {
+static inline bool find_demorecorder(void) {
 #ifdef _WIN32
 	// The "stop" command calls the virtual function demorecorder.IsRecording(),
 	// so just look for the load of the "this" pointer into ECX
@@ -224,7 +224,7 @@ bool demorec_init(void) {
 		return false;
 	}
 	orig_stop_cb = con_getcmdcb(cmd_stop);
-	if (!find_demorecorder(cmd_stop)) {
+	if (!find_demorecorder()) {
 		errmsg_errorx("couldn't find demo recorder instance");
 		return false;
 	}
@@ -245,8 +245,8 @@ bool demorec_init(void) {
 	orig_StopRecording = (StopRecording_func)hook_vtable(vtable,
 			vtidx_StopRecording, (void *)&hook_StopRecording);
 
-	orig_record_cb = cmd_record->cb; cmd_record->cb = &hook_record_cb;
-	orig_stop_cb = cmd_stop->cb; cmd_stop->cb = &hook_stop_cb;
+	cmd_record->cb = &hook_record_cb;
+	cmd_stop->cb = &hook_stop_cb;
 
 	sst_autorecord->base.flags &= ~CON_HIDDEN;
 	return true;
diff --git a/src/sst.c b/src/sst.c
index b7298ef..1321d03 100644
--- a/src/sst.c
+++ b/src/sst.c
@@ -21,6 +21,8 @@
 #include <shlwapi.h>
 #endif
 
+#include "ac.h"
+#include "alias.h"
 #include "autojump.h"
 #include "con_.h"
 #include "demorec.h"
@@ -188,8 +190,8 @@ static const void *const *const plugin_obj;
 // figures out the dependencies at build time and generates all the init glue
 // but we want to actually release the plugin this decade so for now I'm just
 // plonking some bools here and worrying about it later. :^)
-static bool has_autojump = false, has_demorec = false, has_fov = false,
-		has_nosleep = false, has_portalcolours = false;
+static bool has_ac = false,  has_autojump = false, has_demorec = false,
+		has_fov = false, has_nosleep = false, has_portalcolours = false;
 #ifdef _WIN32
 static bool has_rinput = false;
 #endif
@@ -204,6 +206,8 @@ static const char *updatenotes = "\
 ";
 
 static void do_featureinit(void) {
+	has_ac = ac_init();
+	bool has_alias = alias_init();
 	has_autojump = autojump_init();
 	has_demorec = demorec_init();
 	// not enabling demorec_custom yet - kind of incomplete and currently unused
@@ -409,6 +413,7 @@ static void do_unload(void) {
 	}
 #endif
 
+	if (has_ac) ac_end();
 	if (has_autojump) autojump_end();
 	if (has_demorec) demorec_end();
 	if (has_fov) fov_end(); // dep on ent