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/*
* Copyright © 2023 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 "con_.h"
#include "errmsg.h"
#include "feature.h"
#include "gamedata.h"
#include "intdefs.h"
#include "mem.h"
#include "x86.h"
#include "vcall.h"
#include "x86util.h"
FEATURE()
REQUIRE_GAMEDATA(vtidx_GetSpawnCount)
DECL_VFUNC_DYN(int, GetSpawnCount)
static void *sv;
int gameserver_spawncount(void) { return GetSpawnCount(sv); }
static bool find_sv(con_cmdcb pause_cb) {
#ifdef _WIN32
// The last thing pause does is call BroadcastPrintf with 4 args including
// `this`, all on the stack since it's varargs. 2 of the args are pushed
// immediately before `this`, so we can just look for 3 back-to-back pushes
// and a call.
const uchar *insns = (const uchar *)pause_cb;
int pushes = 0;
for (const uchar *p = insns; p - insns < 256;) {
if (*p == X86_PUSHIW || *p >= X86_PUSHEAX && *p <= X86_PUSHEDI) {
if (++pushes == 3) {
if (*p != X86_PUSHIW || p[5] != X86_CALL) {
// it'd be super weird to have this many pushes anywhere
// else in the function, so give up here
return false;
}
sv = mem_loadptr(p + 1);
return true;
}
}
else {
pushes = 0;
}
NEXT_INSN(p, "load of sv pointer");
}
#else
#warning TODO(linux): the usual x86 stuff
#endif
return false;
}
INIT {
struct con_cmd *pause = con_findcmd("pause");
if (!find_sv(pause->cb)) {
errmsg_errorx("couldn't find game server object\n");
return false;
}
return true;
}
// vi: sw=4 ts=4 noet tw=80 cc=80
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