1 /*
2  modules-load.c : irssi
3 
4     Copyright (C) 1999-2001 Timo Sirainen
5 
6     This program is free software; you can redistribute it and/or modify
7     it under the terms of the GNU General Public License as published by
8     the Free Software Foundation; either version 2 of the License, or
9     (at your option) any later version.
10 
11     This program is distributed in the hope that it will be useful,
12     but WITHOUT ANY WARRANTY; without even the implied warranty of
13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14     GNU General Public License for more details.
15 
16     You should have received a copy of the GNU General Public License along
17     with this program; if not, write to the Free Software Foundation, Inc.,
18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20 
21 #include "module.h"
22 #include "modules.h"
23 #include "modules-load.h"
24 #include "signals.h"
25 
26 #include "settings.h"
27 #include "commands.h"
28 #include "misc.h"
29 
30 #ifdef HAVE_GMODULE
31 
32 /* Returns the module name without path, "lib" prefix or ".so" suffix */
module_get_name(const char * path,int * start,int * end)33 static char *module_get_name(const char *path, int *start, int *end)
34 {
35 	const char *name;
36 	char *module_name, *ptr;
37 
38         name = NULL;
39 	if (*path == '~' || g_path_is_absolute(path)) {
40 		name = strrchr(path, G_DIR_SEPARATOR);
41                 if (name != NULL) name++;
42 	}
43 
44 	if (name == NULL)
45 		name = path;
46 
47 	if (strncmp(name, "lib", 3) == 0)
48 		name += 3;
49 
50 	module_name = g_strdup(name);
51 	ptr = strchr(module_name, '.');
52 	if (ptr != NULL) *ptr = '\0';
53 
54 	*start = (int) (name-path);
55 	*end = *start + (ptr == NULL ? strlen(name) :
56 			 (int) (ptr-module_name));
57 
58 	return module_name;
59 }
60 
61 /* Returns the root module name for given submodule (eg. perl_core -> perl) */
module_get_root(const char * name,char ** prefixes)62 static char *module_get_root(const char *name, char **prefixes)
63 {
64 	int len;
65 
66 	/* skip any of the prefixes.. */
67 	if (prefixes != NULL) {
68 		while (*prefixes != NULL) {
69 			len = strlen(*prefixes);
70 			if (strncmp(name, *prefixes, len) == 0 &&
71 			    name[len] == '_') {
72 				name += len+1;
73 				break;
74 			}
75 			prefixes++;
76 		}
77 	}
78 
79 	/* skip the _core part */
80         len = strlen(name);
81 	if (len > 5 && g_strcmp0(name+len-5, "_core") == 0)
82 		return g_strndup(name, len-5);
83 
84         return g_strdup(name);
85 }
86 
87 /* Returns the sub module name for given submodule (eg. perl_core -> core) */
module_get_sub(const char * name,const char * root)88 static char *module_get_sub(const char *name, const char *root)
89 {
90 	int rootlen, namelen;
91 
92         namelen = strlen(name);
93 	rootlen = strlen(root);
94         g_return_val_if_fail(namelen >= rootlen, g_strdup(name));
95 
96 	if (strncmp(name, root, rootlen) == 0 &&
97 	    g_strcmp0(name+rootlen, "_core") == 0)
98                 return g_strdup("core");
99 
100 	if (namelen > rootlen && name[namelen-rootlen-1] == '_' &&
101 	    g_strcmp0(name+namelen-rootlen, root) == 0)
102                 return g_strndup(name, namelen-rootlen-1);
103 
104         return g_strdup(name);
105 }
106 
module_open(const char * name,int * found)107 static GModule *module_open(const char *name, int *found)
108 {
109 	struct stat statbuf;
110 	GModule *module;
111 	char *path, *str;
112 
113 	if (g_path_is_absolute(name) || *name == '~' ||
114 	    (*name == '.' && name[1] == G_DIR_SEPARATOR))
115 		path = g_strdup(name);
116 	else {
117 		/* first try from home dir */
118 		str = g_strdup_printf("%s/modules", get_irssi_dir());
119 		path = g_module_build_path(str, name);
120 		g_free(str);
121 
122 		if (stat(path, &statbuf) == 0) {
123 			module = g_module_open(path, (GModuleFlags) 0);
124 			g_free(path);
125 			*found = TRUE;
126 			return module;
127 		}
128 
129 		/* module not found from home dir, try global module dir */
130 		g_free(path);
131 		path = g_module_build_path(MODULEDIR, name);
132 	}
133 
134 	*found = stat(path, &statbuf) == 0;
135 	module = g_module_open(path, (GModuleFlags) 0);
136 	g_free(path);
137 	return module;
138 }
139 
module_get_func(const char * rootmodule,const char * submodule,const char * function)140 static char *module_get_func(const char *rootmodule, const char *submodule,
141 			     const char *function)
142 {
143 	if (g_strcmp0(submodule, "core") == 0)
144 		return g_strconcat(rootmodule, "_core_", function, NULL);
145 
146 	if (g_strcmp0(rootmodule, submodule) == 0)
147 		return g_strconcat(rootmodule, "_", function, NULL);
148 
149 	return g_strconcat(submodule, "_", rootmodule, "_", function, NULL);
150 }
151 
152 #define module_error(error, text, rootmodule, submodule) \
153 	signal_emit("module error", 4, GINT_TO_POINTER(error), text, \
154 		    rootmodule, submodule)
155 
156 /* Returns 1 if ok, 0 if error in module and
157    -1 if module wasn't found */
module_load_name(const char * path,const char * rootmodule,const char * submodule,int silent)158 static int module_load_name(const char *path, const char *rootmodule,
159 			    const char *submodule, int silent)
160 {
161 	void (*module_init) (void);
162 	void (*module_deinit) (void);
163 	void (*module_version) (int *);
164 	GModule *gmodule;
165         MODULE_REC *module;
166 	MODULE_FILE_REC *rec;
167 	gpointer value_version = NULL;
168 	gpointer value1, value2 = NULL;
169 	char *versionfunc, *initfunc, *deinitfunc;
170 	int module_abi_version = 0;
171         int found;
172 
173 	gmodule = module_open(path, &found);
174 	if (gmodule == NULL) {
175 		if (!silent || found) {
176 			module_error(MODULE_ERROR_LOAD, g_module_error(),
177 				     rootmodule, submodule);
178 		}
179 		return found ? 0 : -1;
180 	}
181 
182 	/* get the module's irssi abi version and bail out on mismatch */
183 	versionfunc = module_get_func(rootmodule, submodule, "abicheck");
184 	if (!g_module_symbol(gmodule, versionfunc, &value_version)) {
185 		g_free(versionfunc);
186 		module_error(MODULE_ERROR_VERSION_MISMATCH, "0",
187 			     rootmodule, submodule);
188 		g_module_close(gmodule);
189 		return 0;
190 	}
191 	g_free(versionfunc);
192 	module_version = value_version;
193 	module_version(&module_abi_version);
194 	if (module_abi_version != IRSSI_ABI_VERSION) {
195 		char *module_abi_versionstr = g_strdup_printf("%d", module_abi_version);
196 		module_error(MODULE_ERROR_VERSION_MISMATCH, module_abi_versionstr,
197 			     rootmodule, submodule);
198 		g_free(module_abi_versionstr);
199 		g_module_close(gmodule);
200 		return 0;
201 	}
202 
203 	/* get the module's init() and deinit() functions */
204 	initfunc = module_get_func(rootmodule, submodule, "init");
205 	deinitfunc = module_get_func(rootmodule, submodule, "deinit");
206 	found = g_module_symbol(gmodule, initfunc, &value1) &&
207 		g_module_symbol(gmodule, deinitfunc, &value2);
208 	g_free(initfunc);
209 	g_free(deinitfunc);
210 
211 	if (!found) {
212 		module_error(MODULE_ERROR_INVALID, NULL,
213 			     rootmodule, submodule);
214 		g_module_close(gmodule);
215 		return 0;
216 	}
217 
218 	module_init = value1;
219 	module_deinit = value2;
220 
221 	/* Call the module's init() function - it should register itself
222 	   with module_register() function, abort if it doesn't. */
223 	module_init();
224 
225 	module = module_find(rootmodule);
226 	rec = module == NULL ? NULL :
227                 g_strcmp0(rootmodule, submodule) == 0 ?
228 		module_file_find(module, "core") :
229 		module_file_find(module, submodule);
230 	if (rec == NULL) {
231 		rec = module_register_full(rootmodule, submodule, NULL);
232 		rec->gmodule = gmodule;
233 		module_file_unload(rec);
234 
235 		module_error(MODULE_ERROR_INVALID, NULL,
236 			     rootmodule, submodule);
237                 return 0;
238 	}
239 
240         rec->module_deinit = module_deinit;
241 	rec->gmodule = gmodule;
242         rec->initialized = TRUE;
243 
244 	settings_check_module(rec->defined_module_name);
245 
246 	signal_emit("module loaded", 2, rec->root, rec);
247 	return 1;
248 }
249 
module_load_prefixes(const char * path,const char * module,int start,int end,char ** prefixes)250 static int module_load_prefixes(const char *path, const char *module,
251 				int start, int end, char **prefixes)
252 {
253         GString *realpath;
254         int status, ok;
255 
256         /* load module_core */
257 	realpath = g_string_new(path);
258 	g_string_insert(realpath, end, "_core");
259 
260 	/* Don't print the error message the first time, since the module
261 	   may not have the core part at all. */
262 	status = module_load_name(realpath->str, module, "core", TRUE);
263         ok = status > 0;
264 
265 	if (prefixes != NULL) {
266 		/* load all the "prefix modules", like the fe-common, irc,
267 		   etc. part of the module */
268 		while (*prefixes != NULL) {
269                         g_string_assign(realpath, path);
270 			g_string_insert_c(realpath, start, '_');
271 			g_string_insert(realpath, start, *prefixes);
272 
273 			status = module_load_name(realpath->str, module,
274 						  *prefixes, TRUE);
275 			if (status > 0)
276 				ok = TRUE;
277 
278                         prefixes++;
279 		}
280 	}
281 
282 	if (!ok) {
283                 /* error loading module, print the error message */
284 		g_string_assign(realpath, path);
285 		g_string_insert(realpath, end, "_core");
286 		module_load_name(realpath->str, module, "core", FALSE);
287 	}
288 
289 	g_string_free(realpath, TRUE);
290         return ok;
291 }
292 
module_load_full(const char * path,const char * rootmodule,const char * submodule,int start,int end,char ** prefixes)293 static int module_load_full(const char *path, const char *rootmodule,
294 			    const char *submodule, int start, int end,
295 			    char **prefixes)
296 {
297 	MODULE_REC *module;
298         int status, try_prefixes;
299 
300 	if (!g_module_supported())
301 		return FALSE;
302 
303 	module = module_find(rootmodule);
304 	if (module != NULL && (g_strcmp0(submodule, rootmodule) == 0 ||
305 			       module_file_find(module, submodule) != NULL)) {
306                 /* module is already loaded */
307 		module_error(MODULE_ERROR_ALREADY_LOADED, NULL,
308 			     rootmodule, submodule);
309                 return FALSE;
310 	}
311 
312 	/* check if the given module exists.. */
313 	try_prefixes = g_strcmp0(rootmodule, submodule) == 0;
314 	status = module_load_name(path, rootmodule, submodule, try_prefixes);
315 	if (status == -1 && try_prefixes) {
316 		/* nope, try loading the module_core,
317 		   fe_module, etc. */
318 		status = module_load_prefixes(path, rootmodule,
319 					      start, end, prefixes);
320 	}
321 
322 	return status > 0;
323 }
324 
325 /* Load module - automatically tries to load also the related non-core
326    modules given in `prefixes' (like irc, fe, fe_text, ..) */
module_load(const char * path,char ** prefixes)327 int module_load(const char *path, char **prefixes)
328 {
329 	char *exppath, *name, *submodule, *rootmodule;
330         int start, end, ret;
331 
332 	g_return_val_if_fail(path != NULL, FALSE);
333 
334 	exppath = convert_home(path);
335 
336 	name = module_get_name(exppath, &start, &end);
337 	rootmodule = module_get_root(name, prefixes);
338 	submodule = module_get_sub(name, rootmodule);
339 	g_free(name);
340 
341 	ret = module_load_full(exppath, rootmodule, submodule,
342 			       start, end, prefixes);
343 
344 	g_free(rootmodule);
345 	g_free(submodule);
346         g_free(exppath);
347         return ret;
348 }
349 
350 /* Load a sub module. */
module_load_sub(const char * path,const char * submodule,char ** prefixes)351 int module_load_sub(const char *path, const char *submodule, char **prefixes)
352 {
353         GString *full_path;
354 	char *exppath, *name, *rootmodule;
355         int start, end, ret;
356 
357 	g_return_val_if_fail(path != NULL, FALSE);
358 	g_return_val_if_fail(submodule != NULL, FALSE);
359 
360         exppath = convert_home(path);
361 
362 	name = module_get_name(exppath, &start, &end);
363 	rootmodule = module_get_root(name, prefixes);
364 	g_free(name);
365 
366         full_path = g_string_new(exppath);
367 	if (g_strcmp0(submodule, "core") == 0)
368 		g_string_insert(full_path, end, "_core");
369 	else {
370 		g_string_insert_c(full_path, start, '_');
371 		g_string_insert(full_path, start, submodule);
372 	}
373 
374 	ret = module_load_full(full_path->str, rootmodule, submodule,
375 			       start, end, NULL);
376 
377 	g_string_free(full_path, TRUE);
378 	g_free(rootmodule);
379 	g_free(exppath);
380         return ret;
381 }
382 
module_file_deinit_gmodule(MODULE_FILE_REC * file)383 static void module_file_deinit_gmodule(MODULE_FILE_REC *file)
384 {
385 	/* call the module's deinit() function */
386         if (file->module_deinit != NULL)
387 		file->module_deinit();
388 
389 	if (file->defined_module_name != NULL) {
390 		settings_remove_module(file->defined_module_name);
391 		commands_remove_module(file->defined_module_name);
392 		signals_remove_module(file->defined_module_name);
393 	}
394 
395 	g_module_close(file->gmodule);
396 }
397 
398 #else /* !HAVE_GMODULE - modules are not supported */
399 
module_load(const char * path,char ** prefixes)400 int module_load(const char *path, char **prefixes)
401 {
402         return FALSE;
403 }
404 
405 #endif
406 
module_file_unload(MODULE_FILE_REC * file)407 void module_file_unload(MODULE_FILE_REC *file)
408 {
409 	MODULE_REC *root;
410 
411         root = file->root;
412 	root->files = g_slist_remove(root->files, file);
413 
414         if (file->initialized)
415 		signal_emit("module unloaded", 2, file->root, file);
416 
417 #ifdef HAVE_GMODULE
418 	if (file->gmodule != NULL)
419                 module_file_deinit_gmodule(file);
420 #endif
421 
422 	g_free(file->name);
423 	g_free(file->defined_module_name);
424 	g_free(file);
425 
426 	if (root->files == NULL && g_slist_find(modules, root) != NULL)
427                 module_unload(root);
428 }
429 
module_unload(MODULE_REC * module)430 void module_unload(MODULE_REC *module)
431 {
432 	g_return_if_fail(module != NULL);
433 
434 	modules = g_slist_remove(modules, module);
435 
436 	signal_emit("module unloaded", 1, module);
437 
438 	while (module->files != NULL)
439                 module_file_unload(module->files->data);
440 
441         g_free(module->name);
442 	g_free(module);
443 }
444