summaryrefslogtreecommitdiffhomepage
path: root/src/sst.c
blob: 1d0d18a1052774c7de09dbbd397b1c8995594353 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
/*
 * 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 "autojump.h"
#include "con_.h"
#include "demorec.h"
#include "factory.h"
#include "fixes.h"
#include "gamedata.h"
#include "gameinfo.h"
#include "gametype.h"
#include "hook.h"
#include "os.h"
#include "rinput.h"
#include "vcall.h"
#include "version.h"

#define RGBA(r, g, b, a) (&(struct con_colour){(r), (g), (b), (a)})

u32 _gametype_tag = 0; // spaghetti: no point making a .c file for 1 variable

static int ifacever;
// this is where we start dynamically adding virtual functions, see vtable[]
// array below
static const void **vtable_firstdiff;
static const void *const *const plugin_obj;

// most plugin callbacks are unused - define dummy functions for each signature
static void VCALLCONV nop_v_v(void *this) {}
static void VCALLCONV nop_b_v(void *this, bool b) {}
static void VCALLCONV nop_p_v(void *this, void *p) {}
static void VCALLCONV nop_pp_v(void *this, void *p1, void *p2) {}
static void VCALLCONV nop_pii_v(void *this, void *p, int i1, int i2) {}
static int VCALLCONV nop_p_i(void *this, void *p) { return 0; }
static int VCALLCONV nop_pp_i(void *this, void *p1, void *p2) { return 0; }
static int VCALLCONV nop_5pi_i(void *this, void *p1, void *p2, void *p3,
		void *p4, void *p5, int i) { return 0; }
static void VCALLCONV nop_ipipp_v(void *this, int i1, void *p1, int i2,
		void *p2, void *p3) {}

#ifdef __linux__
// we need to keep this reference to dlclose() it later - see below
static void *clientlib = 0;
#endif

// more source spaghetti wow!
static void VCALLCONV SetCommandClient(void *this, int i) { con_cmdclient = i; }

ifacefactory factory_client = 0, factory_server = 0, factory_engine = 0;

// TODO(featgen): I wanted some nice fancy automatic feature system that
// 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;
static bool has_demorec = false;
static bool has_demorec_custom = false;
#ifdef _WIN32
static bool has_rinput = false;
#endif

// since this is static/global, it only becomes false again when the plugin SO
// is unloaded/reloaded
static bool already_loaded = false;
static bool skip_unload = false;

// HACK: later versions of L4D2 show an annoying dialog on every plugin_load.
// We can suppress this by catching the message string that's passed from
// engine.dll to gameui.dll through KeyValuesSystem in vstdlib.dll and just
// replacing it with some other arbitrary garbage string. This makes gameui fail
// to match the message and thus do nothing. :)
static void **kvsvt;
typedef const char *(*VCALLCONV GetStringForSymbol_func)(void *this, int s);
static GetStringForSymbol_func orig_GetStringForSymbol = 0;
static const char *VCALLCONV GetStringForSymbol_hook(void *this, int s) {
	const char *ret = orig_GetStringForSymbol(this, s);
	if (!strcmp(ret, "OnClientPluginWarning")) ret = "sstBlockedThisEvent";
	return ret;
}

// vstdlib symbol, only currently used in l4d2 but exists everywhere so oh well
IMPORT void *KeyValuesSystem(void);

// XXX: not sure if all this stuff should, like, go somewhere?

struct CUtlMemory {
	void *mem;
	int alloccnt;
	int growsz;
};

struct CUtlVector {
	struct CUtlMemory m;
	int sz;
	void *mem_again_for_some_reason;
};

struct CServerPlugin /* : IServerPluginHelpers */ {
	void **vtable;
	struct CUtlVector plugins;
	/*IPluginHelpersCheck*/ void *pluginhlpchk;
};

struct CPlugin {
	char description[128];
	bool paused;
	void *theplugin; // our own "this" pointer (or whichever other plugin it is)
	int ifacever;
	// should be the plugin library, but in old Source branches it's just null,
	// because CServerPlugin::Load() erroneously shadows this field with a local
	void *module;
};

#ifdef _WIN32
extern long __ImageBase; // this is actually the PE header struct but don't care
#define ownhandle() ((void *)&__ImageBase)
#else
// sigh, _GNU_SOURCE crap. define here instead >:(
typedef struct {
	const char *dli_fname;
	void *dli_fbase;
	const char *dli_sname;
	void *dli_saddr;
} Dl_info;
int dladdr1(const void *addr, Dl_info *info, void **extra_info, int flags);
static inline void *ownhandle(void) {
	Dl_info dontcare;
	void *dl;
	dladdr1((void *)&ownhandle, &dontcare, &dl, /*RTLD_DL_LINKMAP*/ 2);
	return dl;
}
#endif

static bool do_load(ifacefactory enginef, ifacefactory serverf) {
	factory_engine = enginef; factory_server = serverf;
#ifndef __linux__
	void *clientlib = 0;
#endif
	if (!con_init(enginef, ifacever)) return false;
	if (!gameinfo_init(enginef)) { con_disconnect(); return false; }
	const void **p = vtable_firstdiff;
	if (GAMETYPE_MATCHES(Portal2)) *p++ = (void *)&nop_p_v; // ClientFullyConnect
	*p++ = (void *)&nop_p_v;		  // ClientDisconnect
	*p++ = (void *)&nop_pp_v;		  // ClientPutInServer
	*p++ = (void *)&SetCommandClient; // SetCommandClient
	*p++ = (void *)&nop_p_v;		  // ClientSettingsChanged
	*p++ = (void *)&nop_5pi_i;		  // ClientConnect
	*p++ = ifacever > 1 ? (void *)&nop_pp_i : (void *)&nop_p_i; // ClientCommand
	// remaining stuff here is backwards compatible, so added unconditionally
	*p++ = (void *)&nop_pp_i;		  // NetworkIDValidated
	*p++ = (void *)&nop_ipipp_v;	  // OnQueryCvarValueFinished (002+)
	*p++ = (void *)&nop_p_v;		  // OnEdictAllocated
	*p   = (void *)&nop_p_v;		  // OnEdictFreed

#ifdef _WIN32
	//if (gameinfo_serverlib) serverlib = GetModuleHandleW(gameinfo_serverlib);
	if (gameinfo_clientlib) clientlib = GetModuleHandleW(gameinfo_clientlib);
#else
	// Linux Source load order seems to be different to the point where if we
	// +plugin_load or use a vdf then RTLD_NOLOAD won't actually find these, so
	// we have to just dlopen them normally - and then remember to decrement the
	// refcount again later in do_unload() so nothing gets leaked
	//if (gameinfo_serverlib) serverlib = dlopen(gameinfo_serverlib, 0);
	if (gameinfo_clientlib) clientlib = dlopen(gameinfo_clientlib, 0);
#endif
	if (!clientlib) {
		con_warn("sst: warning: couldn't get the game's client library\n");
		goto nc;
	}
	factory_client = (ifacefactory)os_dlsym(clientlib, "CreateInterface");
	if (!factory_client) {
		con_warn("sst: warning: couldn't get client's CreateInterface\n");
	}

nc:	gamedata_init();
	has_autojump = autojump_init();
	has_demorec = demorec_init();
#ifdef _WIN32
	has_rinput = rinput_init();
#endif
	if (has_demorec) has_demorec_custom = demorec_custom_init();
	fixes_apply();

	// NOTE: this is technically redundant for early versions but I CBA writing
	// a version check; it's easier to just do this unilaterally.
	if (GAMETYPE_MATCHES(L4D2x)) {
		void *kvs = KeyValuesSystem();
		kvsvt = *(void ***)kvs;
		if (!os_mprot(kvsvt + 4, sizeof(void *), PAGE_READWRITE)) {
			con_warn("sst: warning: couldn't unprotect KeyValuesSystem "
					"vtable; won't be able to prevent nag message\n");
			goto e;
		}
		orig_GetStringForSymbol = (GetStringForSymbol_func)hook_vtable(kvsvt,
				4, (void *)GetStringForSymbol_hook);
	}

e:	con_colourmsg(RGBA(64, 255, 64, 255),
			LONGNAME " v" VERSION " successfully loaded");
	con_colourmsg(RGBA(255, 255, 255, 255), " for game ");
	con_colourmsg(RGBA(0, 255, 255, 255), "%s\n", gameinfo_title);
	return true;
}

static void do_unload(void) {
	struct CServerPlugin *pluginhandler =
			factory_engine("ISERVERPLUGINHELPERS001", 0);
	if (pluginhandler) { // if not, oh well too bad we tried :^)
		struct CPlugin **plugins = pluginhandler->plugins.m.mem;
		int n = pluginhandler->plugins.sz;
		for (struct CPlugin **pp = plugins; pp - plugins < n; ++pp) {
			if ((*pp)->theplugin = (void *)&plugin_obj) {
				// see comment in CPlugin above. setting this to the real handle
				// right before the engine tries to unload us allows it to
				// actually unload us instead of just doing nothing.
				// in newer branches that don't have this bug, this is still
				// correct anyway so no need to bother checking.
				(*pp)->module = ownhandle();
				break;
			}
		}
	}

	if (has_autojump) autojump_end();
	if (has_demorec) demorec_end();
#ifdef _WIN32
	if (has_rinput) rinput_end();
#endif

#ifdef __linux__
	//if (serverlib) dlclose(serverlib);
	if (clientlib) dlclose(clientlib);
#endif
	con_disconnect();

	if (orig_GetStringForSymbol) {
		unhook_vtable(kvsvt, 4, (void *)orig_GetStringForSymbol);
	}
}

static bool VCALLCONV Load(void *this, ifacefactory enginef,
		ifacefactory serverf) {
	if (already_loaded) {
		con_warn("Already loaded! Doing nothing!\n");
		skip_unload = true;
		return false;
	}
	already_loaded = do_load(enginef, serverf);
	skip_unload = !already_loaded;
	return already_loaded;
}

static void VCALLCONV Unload(void *this) {
	// the game tries to unload on a failed load, for some reason
	if (skip_unload) {
		skip_unload = false;
		return;
	}
	do_unload();
}

static void VCALLCONV Pause(void *this) {
	con_warn(NAME " doesn't support plugin_pause - ignoring\n");
}
static void VCALLCONV UnPause(void *this) {
	con_warn(NAME " doesn't support plugin_unpause - ignoring\n");
}

static const char *VCALLCONV GetPluginDescription(void *this) {
	return LONGNAME " v" VERSION;
}

DEF_CCMD_HERE(sst_printversion, "Display plugin version information", 0) {
	con_msg("v" VERSION "\n");
}

#define MAX_VTABLE_FUNCS 21
static const void *vtable[MAX_VTABLE_FUNCS] = {
	// start off with the members which (thankfully...) are totally stable
	// between interface versions - the *remaining* members get filled in just
	// in time by do_load() once we've figured out what engine branch we're on
	(void *)&Load,
	(void *)&Unload,
	(void *)&Pause,
	(void *)&UnPause,
	(void *)&GetPluginDescription,
	(void *)&nop_p_v,	// LevelInit
	(void *)&nop_pii_v, // ServerActivate
	(void *)&nop_b_v,	// GameFrame
	(void *)&nop_v_v,	// LevelShutdown
	(void *)&nop_p_v	// ClientActive
	// At this point, Alien Swarm and Portal 2 add ClientFullyConnect, so we
	// can't hardcode any more of the layout!
};
// end MUST point AFTER the last of the above entries
static const void **vtable_firstdiff = vtable + 10;
// this is equivalent to a class with no members!
static const void *const *const plugin_obj = vtable;

EXPORT const void *CreateInterface(const char *name, int *ret) {
	if (!strncmp(name, "ISERVERPLUGINCALLBACKS00", 24)) {
		if ((name[24] >= '1' || name[24] <= '3') && name[25] == '\0') {
			if (ret) *ret = 0;
			ifacever = name[24] - '0';
			return &plugin_obj;
		}
	}
	if (ret) *ret = 1;
	return 0;
}

// vi: sw=4 ts=4 noet tw=80 cc=80