1 /* vi: set sw=4 ts=4: */
2 /*
3  * Modprobe written from scratch for BusyBox
4  *
5  * Copyright (c) 2008 Timo Teras <timo.teras@iki.fi>
6  * Copyright (c) 2008 Vladimir Dronnikov
7  *
8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
9  */
10 //config:config MODPROBE
11 //config:	bool "modprobe (28 kb)"
12 //config:	default y
13 //config:	help
14 //config:	Handle the loading of modules, and their dependencies on a high
15 //config:	level.
16 //config:
17 //config:config FEATURE_MODPROBE_BLACKLIST
18 //config:	bool "Blacklist support"
19 //config:	default y
20 //config:	depends on MODPROBE && !MODPROBE_SMALL
21 //config:	help
22 //config:	Say 'y' here to enable support for the 'blacklist' command in
23 //config:	modprobe.conf. This prevents the alias resolver to resolve
24 //config:	blacklisted modules. This is useful if you want to prevent your
25 //config:	hardware autodetection scripts to load modules like evdev, frame
26 //config:	buffer drivers etc.
27 
28 //applet:IF_MODPROBE(IF_NOT_MODPROBE_SMALL(APPLET_NOEXEC(modprobe, modprobe, BB_DIR_SBIN, BB_SUID_DROP, modprobe)))
29 
30 //kbuild:ifneq ($(CONFIG_MODPROBE_SMALL),y)
31 //kbuild:lib-$(CONFIG_MODPROBE) += modprobe.o modutils.o
32 //kbuild:endif
33 
34 #include "libbb.h"
35 #include "modutils.h"
36 #include <sys/utsname.h>
37 #include <fnmatch.h>
38 
39 #if 1
40 #define DBG(...) ((void)0)
41 #else
42 #define DBG(fmt, ...) bb_error_msg("%s: " fmt, __func__, ## __VA_ARGS__)
43 #endif
44 
45 /* Note that unlike older versions of modules.dep/depmod (busybox and m-i-t),
46  * we expect the full dependency list to be specified in modules.dep.
47  * Older versions would only export the direct dependency list.
48  */
49 
50 
51 //usage:#if !ENABLE_MODPROBE_SMALL
52 //usage:#define modprobe_notes_usage
53 //usage:	"modprobe can (un)load a stack of modules, passing each module options (when\n"
54 //usage:	"loading). modprobe uses a configuration file to determine what option(s) to\n"
55 //usage:	"pass each module it loads.\n"
56 //usage:	"\n"
57 //usage:	"The configuration file is searched (in this order):\n"
58 //usage:	"\n"
59 //usage:	"    /etc/modprobe.conf (2.6 only)\n"
60 //usage:	"    /etc/modules.conf\n"
61 //usage:	"    /etc/conf.modules (deprecated)\n"
62 //usage:	"\n"
63 //usage:	"They all have the same syntax (see below). If none is present, it is\n"
64 //usage:	"_not_ an error; each loaded module is then expected to load without\n"
65 //usage:	"options. Once a file is found, the others are tested for.\n"
66 //usage:	"\n"
67 //usage:	"/etc/modules.conf entry format:\n"
68 //usage:	"\n"
69 //usage:	"  alias <alias_name> <mod_name>\n"
70 //usage:	"    Makes it possible to modprobe alias_name, when there is no such module.\n"
71 //usage:	"    It makes sense if your mod_name is long, or you want a more representative\n"
72 //usage:	"    name for that module (eg. 'scsi' in place of 'aha7xxx').\n"
73 //usage:	"    This makes it also possible to use a different set of options (below) for\n"
74 //usage:	"    the module and the alias.\n"
75 //usage:	"    A module can be aliased more than once.\n"
76 //usage:	"\n"
77 //usage:	"  options <mod_name|alias_name> <symbol=value...>\n"
78 //usage:	"    When loading module mod_name (or the module aliased by alias_name), pass\n"
79 //usage:	"    the \"symbol=value\" pairs as option to that module.\n"
80 //usage:	"\n"
81 //usage:	"Sample /etc/modules.conf file:\n"
82 //usage:	"\n"
83 //usage:	"  options tulip irq=3\n"
84 //usage:	"  alias tulip tulip2\n"
85 //usage:	"  options tulip2 irq=4 io=0x308\n"
86 //usage:	"\n"
87 //usage:	"Other functionality offered by 'classic' modprobe is not available in\n"
88 //usage:	"this implementation.\n"
89 //usage:	"\n"
90 //usage:	"If module options are present both in the config file, and on the command line,\n"
91 //usage:	"then the options from the command line will be passed to the module _after_\n"
92 //usage:	"the options from the config file. That way, you can have defaults in the config\n"
93 //usage:	"file, and override them for a specific usage from the command line.\n"
94 //usage:#define modprobe_example_usage
95 //usage:       "(with the above /etc/modules.conf):\n\n"
96 //usage:       "$ modprobe tulip\n"
97 //usage:       "   will load the module 'tulip' with default option 'irq=3'\n\n"
98 //usage:       "$ modprobe tulip irq=5\n"
99 //usage:       "   will load the module 'tulip' with option 'irq=5', thus overriding the default\n\n"
100 //usage:       "$ modprobe tulip2\n"
101 //usage:       "   will load the module 'tulip' with default options 'irq=4 io=0x308',\n"
102 //usage:       "   which are the default for alias 'tulip2'\n\n"
103 //usage:       "$ modprobe tulip2 irq=8\n"
104 //usage:       "   will load the module 'tulip' with default options 'irq=4 io=0x308 irq=8',\n"
105 //usage:       "   which are the default for alias 'tulip2' overridden by the option 'irq=8'\n\n"
106 //usage:       "   from the command line\n\n"
107 //usage:       "$ modprobe tulip2 irq=2 io=0x210\n"
108 //usage:       "   will load the module 'tulip' with default options 'irq=4 io=0x308 irq=4 io=0x210',\n"
109 //usage:       "   which are the default for alias 'tulip2' overridden by the options 'irq=2 io=0x210'\n\n"
110 //usage:       "   from the command line\n"
111 //usage:
112 //usage:#define modprobe_trivial_usage
113 //usage:	"[-alrqvsD" IF_FEATURE_MODPROBE_BLACKLIST("b") "]"
114 //usage:	" MODULE" IF_FEATURE_CMDLINE_MODULE_OPTIONS(" [SYMBOL=VALUE]...")
115 //usage:#define modprobe_full_usage "\n\n"
116 //usage:       "	-a	Load multiple MODULEs"
117 //usage:     "\n	-l	List (MODULE is a pattern)"
118 //usage:     "\n	-r	Remove MODULE (stacks) or do autoclean"
119 //usage:     "\n	-q	Quiet"
120 //usage:     "\n	-v	Verbose"
121 //usage:     "\n	-s	Log to syslog"
122 //usage:     "\n	-D	Show dependencies"
123 //usage:	IF_FEATURE_MODPROBE_BLACKLIST(
124 //usage:     "\n	-b	Apply blacklist to module names too"
125 //usage:	)
126 //usage:#endif /* !ENABLE_MODPROBE_SMALL */
127 
128 /* Note: usage text doesn't document various 2.4 options
129  * we pull in through INSMOD_OPTS define
130  * Note2: -b is always accepted, but if !FEATURE_MODPROBE_BLACKLIST,
131  * it is a no-op.
132  */
133 #define MODPROBE_OPTS  "alrDb"
134 /* -a and -D _are_ in fact compatible */
135 #define MODPROBE_COMPLEMENTARY "q-v:v-q:l--arD:r--alD:a--lr:D--rl"
136 //#define MODPROBE_OPTS  "acd:lnrt:C:b"
137 //#define MODPROBE_COMPLEMENTARY "q-v:v-q:l--acr:a--lr:r--al"
138 enum {
139 	OPT_INSERT_ALL   = (INSMOD_OPT_UNUSED << 0), /* a */
140 	//OPT_DUMP_ONLY  = (INSMOD_OPT_UNUSED << x), /* c */
141 	//OPT_DIRNAME    = (INSMOD_OPT_UNUSED << x), /* d */
142 	OPT_LIST_ONLY    = (INSMOD_OPT_UNUSED << 1), /* l */
143 	//OPT_SHOW_ONLY  = (INSMOD_OPT_UNUSED << x), /* n */
144 	OPT_REMOVE       = (INSMOD_OPT_UNUSED << 2), /* r */
145 	//OPT_RESTRICT   = (INSMOD_OPT_UNUSED << x), /* t */
146 	//OPT_VERONLY    = (INSMOD_OPT_UNUSED << x), /* V */
147 	//OPT_CONFIGFILE = (INSMOD_OPT_UNUSED << x), /* C */
148 	OPT_SHOW_DEPS    = (INSMOD_OPT_UNUSED << 3), /* D */
149 	OPT_BLACKLIST    = (INSMOD_OPT_UNUSED << 4) * ENABLE_FEATURE_MODPROBE_BLACKLIST,
150 };
151 #if ENABLE_LONG_OPTS
152 static const char modprobe_longopts[] ALIGN1 =
153 	/* nobody asked for long opts (yet) */
154 	// "all\0"          No_argument "a"
155 	// "list\0"         No_argument "l"
156 	// "remove\0"       No_argument "r"
157 	// "quiet\0"        No_argument "q"
158 	// "verbose\0"      No_argument "v"
159 	// "syslog\0"       No_argument "s"
160 	/* module-init-tools 3.11.1 has only long opt --show-depends
161 	 * but no short -D, we provide long opt for scripts which
162 	 * were written for 3.11.1: */
163 	"show-depends\0"     No_argument "D"
164 	// "use-blacklist\0" No_argument "b"
165 	;
166 #endif
167 
168 #define MODULE_FLAG_LOADED              0x0001
169 #define MODULE_FLAG_NEED_DEPS           0x0002
170 /* "was seen in modules.dep": */
171 #define MODULE_FLAG_FOUND_IN_MODDEP     0x0004
172 #define MODULE_FLAG_BLACKLISTED         0x0008
173 #define MODULE_FLAG_BUILTIN             0x0010
174 
175 struct globals {
176 	llist_t *probes; /* MEs of module(s) requested on cmdline */
177 #if ENABLE_FEATURE_CMDLINE_MODULE_OPTIONS
178 	char *cmdline_mopts; /* module options from cmdline */
179 #endif
180 	int num_unresolved_deps;
181 	/* bool. "Did we have 'symbol:FOO' requested on cmdline?" */
182 	smallint need_symbols;
183 	struct utsname uts;
184 	module_db db;
185 } FIX_ALIASING;
186 #define G (*ptr_to_globals)
187 #define INIT_G() do { \
188 	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
189 } while (0)
190 
191 
192 static int read_config(const char *path);
193 
gather_options_str(char * opts,const char * append)194 static char *gather_options_str(char *opts, const char *append)
195 {
196 	/* Speed-optimized. We call gather_options_str many times. */
197 	if (append) {
198 		if (opts == NULL) {
199 			opts = xstrdup(append);
200 		} else {
201 			int optlen = strlen(opts);
202 			opts = xrealloc(opts, optlen + strlen(append) + 2);
203 			sprintf(opts + optlen, " %s", append);
204 		}
205 	}
206 	return opts;
207 }
208 
get_or_add_modentry(const char * module)209 static struct module_entry *get_or_add_modentry(const char *module)
210 {
211 	return moddb_get_or_create(&G.db, module);
212 }
213 
add_probe(const char * name)214 static void add_probe(const char *name)
215 {
216 	struct module_entry *m;
217 
218 	m = get_or_add_modentry(name);
219 	if (!(option_mask32 & (OPT_REMOVE | OPT_SHOW_DEPS))
220 	 && (m->flags & (MODULE_FLAG_LOADED | MODULE_FLAG_BUILTIN))
221 	) {
222 		DBG("skipping %s, it is already loaded", name);
223 		return;
224 	}
225 
226 	DBG("queuing %s", name);
227 	m->probed_name = name;
228 	m->flags |= MODULE_FLAG_NEED_DEPS;
229 	llist_add_to_end(&G.probes, m);
230 	G.num_unresolved_deps++;
231 	if (ENABLE_FEATURE_MODUTILS_SYMBOLS
232 	 && is_prefixed_with(m->modname, "symbol:")
233 	) {
234 		G.need_symbols = 1;
235 	}
236 }
237 
config_file_action(struct recursive_state * state,const char * filename,struct stat * statbuf UNUSED_PARAM)238 static int FAST_FUNC config_file_action(struct recursive_state *state,
239 		const char *filename,
240 		struct stat *statbuf UNUSED_PARAM)
241 {
242 	char *tokens[3];
243 	parser_t *p;
244 	struct module_entry *m;
245 	int rc = TRUE;
246 	const char *base;
247 
248 	/* Skip files that begin with a "." */
249 	base = bb_basename(filename);
250 	if (base[0] == '.')
251 		goto error;
252 
253 	/* "man modprobe.d" from kmod version 22 suggests
254 	 * that we shouldn't recurse into /etc/modprobe.d/dir/
255 	 * _subdirectories_:
256 	 */
257 	if (state->depth > 1)
258 		return SKIP; /* stop recursing */
259 //TODO: instead, can use dirAction in recursive_action() to SKIP dirs
260 //on depth == 1 level. But that's more code...
261 
262 	/* In dir recursion, skip files that do not end with a ".conf"
263 	 * depth==0: read_config("modules.{symbols,alias}") must work,
264 	 * "include FILE_NOT_ENDING_IN_CONF" must work too.
265 	 */
266 	if (state->depth != 0) {
267 		if (!is_suffixed_with(base, ".conf"))
268 			goto error;
269 	}
270 
271 	p = config_open2(filename, fopen_for_read);
272 	if (p == NULL) {
273 		rc = FALSE;
274 		goto error;
275 	}
276 
277 	while (config_read(p, tokens, 3, 2, "# \t", PARSE_NORMAL)) {
278 //Use index_in_strings?
279 		if (strcmp(tokens[0], "alias") == 0) {
280 			/* alias <wildcard> <modulename> */
281 			llist_t *l;
282 			char wildcard[MODULE_NAME_LEN];
283 			char *rmod;
284 
285 			if (tokens[2] == NULL)
286 				continue;
287 			filename2modname(tokens[1], wildcard);
288 
289 			for (l = G.probes; l; l = l->link) {
290 				m = (struct module_entry *) l->data;
291 				if (fnmatch(wildcard, m->modname, 0) != 0)
292 					continue;
293 				rmod = filename2modname(tokens[2], NULL);
294 				llist_add_to(&m->realnames, rmod);
295 
296 				if (m->flags & MODULE_FLAG_NEED_DEPS) {
297 					m->flags &= ~MODULE_FLAG_NEED_DEPS;
298 					G.num_unresolved_deps--;
299 				}
300 
301 				m = get_or_add_modentry(rmod);
302 				if (!(m->flags & MODULE_FLAG_NEED_DEPS)) {
303 					m->flags |= MODULE_FLAG_NEED_DEPS;
304 					G.num_unresolved_deps++;
305 				}
306 			}
307 		} else if (strcmp(tokens[0], "options") == 0) {
308 			/* options <modulename> <option...> */
309 			if (tokens[2] == NULL)
310 				continue;
311 			m = get_or_add_modentry(tokens[1]);
312 			m->options = gather_options_str(m->options, tokens[2]);
313 		} else if (strcmp(tokens[0], "include") == 0) {
314 			/* include <filename>/<dirname> (yes, directories also must work) */
315 			read_config(tokens[1]);
316 		} else if (ENABLE_FEATURE_MODPROBE_BLACKLIST
317 		 && strcmp(tokens[0], "blacklist") == 0
318 		) {
319 			/* blacklist <modulename> */
320 			get_or_add_modentry(tokens[1])->flags |= MODULE_FLAG_BLACKLISTED;
321 		}
322 	}
323 	config_close(p);
324  error:
325 	return rc;
326 }
327 
read_config(const char * path)328 static int read_config(const char *path)
329 {
330 	return recursive_action(path, ACTION_RECURSE | ACTION_QUIET,
331 				config_file_action, NULL, NULL);
332 }
333 
humanly_readable_name(struct module_entry * m)334 static const char *humanly_readable_name(struct module_entry *m)
335 {
336 	/* probed_name may be NULL. modname always exists. */
337 	return m->probed_name ? m->probed_name : m->modname;
338 }
339 
340 /* Like strsep(&stringp, "\n\t ") but quoted text goes to single token
341  * even if it contains whitespace.
342  */
strsep_quotes(char ** stringp)343 static char *strsep_quotes(char **stringp)
344 {
345 	char *s, *start = *stringp;
346 
347 	if (!start)
348 		return NULL;
349 
350 	for (s = start; ; s++) {
351 		switch (*s) {
352 		case '"':
353 			s = strchrnul(s + 1, '"'); /* find trailing quote */
354 			if (*s != '\0')
355 				s++; /* skip trailing quote */
356 			/* fall through */
357 		case '\0':
358 		case '\n':
359 		case '\t':
360 		case ' ':
361 			if (*s != '\0') {
362 				*s = '\0';
363 				*stringp = s + 1;
364 			} else {
365 				*stringp = NULL;
366 			}
367 			return start;
368 		}
369 	}
370 }
371 
parse_and_add_kcmdline_module_options(char * options,const char * modulename)372 static char *parse_and_add_kcmdline_module_options(char *options, const char *modulename)
373 {
374 	char *kcmdline_buf;
375 	char *kcmdline;
376 	char *kptr;
377 
378 	kcmdline_buf = xmalloc_open_read_close("/proc/cmdline", NULL);
379 	if (!kcmdline_buf)
380 		return options;
381 
382 	kcmdline = kcmdline_buf;
383 	while ((kptr = strsep_quotes(&kcmdline)) != NULL) {
384 		char *after_modulename = is_prefixed_with(kptr, modulename);
385 		if (!after_modulename || *after_modulename != '.')
386 			continue;
387 		/* It is "modulename.xxxx" */
388 		kptr = after_modulename + 1;
389 		if (strchr(kptr, '=') != NULL) {
390 			/* It is "modulename.opt=[val]" */
391 			options = gather_options_str(options, kptr);
392 		}
393 	}
394 	free(kcmdline_buf);
395 
396 	return options;
397 }
398 
399 /* Return: similar to bb_init_module:
400  * 0 on success,
401  * -errno on open/read error,
402  * errno on init_module() error
403  */
404 /* NB: INSMOD_OPT_SILENT bit suppresses ONLY non-existent modules,
405  * not deleted ones (those are still listed in modules.dep).
406  * module-init-tools version 3.4:
407  * # modprobe bogus
408  * FATAL: Module bogus not found. [exitcode 1]
409  * # modprobe -q bogus            [silent, exitcode still 1]
410  * but:
411  * # rm kernel/drivers/net/dummy.ko
412  * # modprobe -q dummy
413  * FATAL: Could not open '/lib/modules/xxx/kernel/drivers/net/dummy.ko': No such file or directory
414  * [exitcode 1]
415  */
do_modprobe(struct module_entry * m)416 static int do_modprobe(struct module_entry *m)
417 {
418 	int rc, first;
419 
420 	if (!(m->flags & MODULE_FLAG_FOUND_IN_MODDEP)) {
421 		if (!(option_mask32 & INSMOD_OPT_SILENT))
422 			bb_error_msg((m->flags & MODULE_FLAG_BUILTIN) ?
423 				     "module %s is builtin" :
424 				     "module %s not found in modules.dep",
425 				     humanly_readable_name(m));
426 		return -ENOENT;
427 	}
428 	DBG("do_modprob'ing %s", m->modname);
429 
430 	if (!(option_mask32 & OPT_REMOVE))
431 		m->deps = llist_rev(m->deps);
432 
433 	if (0) {
434 		llist_t *l;
435 		for (l = m->deps; l; l = l->link)
436 			DBG("dep: %s", l->data);
437 	}
438 
439 	first = 1;
440 	rc = 0;
441 	while (m->deps) {
442 		struct module_entry *m2;
443 		char *fn, *options;
444 
445 		rc = 0;
446 		fn = llist_pop(&m->deps); /* we leak it */
447 		m2 = get_or_add_modentry(bb_get_last_path_component_nostrip(fn));
448 
449 		if (option_mask32 & OPT_REMOVE) {
450 			/* modprobe -r */
451 			if (m2->flags & MODULE_FLAG_LOADED) {
452 				rc = bb_delete_module(m2->modname, O_EXCL);
453 				if (rc) {
454 					if (first) {
455 						bb_perror_msg("can't unload module '%s'",
456 							humanly_readable_name(m2));
457 						break;
458 					}
459 				} else {
460 					m2->flags &= ~MODULE_FLAG_LOADED;
461 				}
462 			}
463 			/* do not error out if *deps* fail to unload */
464 			first = 0;
465 			continue;
466 		}
467 
468 		options = m2->options;
469 		m2->options = NULL;
470 		options = parse_and_add_kcmdline_module_options(options, m2->modname);
471 #if ENABLE_FEATURE_CMDLINE_MODULE_OPTIONS
472 		if (m == m2)
473 			options = gather_options_str(options, G.cmdline_mopts);
474 #endif
475 
476 		if (option_mask32 & OPT_SHOW_DEPS) {
477 			printf(options ? "insmod %s/%s/%s %s\n"
478 					: "insmod %s/%s/%s\n",
479 				CONFIG_DEFAULT_MODULES_DIR, G.uts.release, fn,
480 				options);
481 			free(options);
482 			continue;
483 		}
484 
485 		if (m2->flags & MODULE_FLAG_LOADED) {
486 			DBG("%s is already loaded, skipping", fn);
487 			free(options);
488 			continue;
489 		}
490 
491 		rc = bb_init_module(fn, options);
492 		DBG("loaded %s '%s', rc:%d", fn, options, rc);
493 		if (rc == EEXIST)
494 			rc = 0;
495 		free(options);
496 		if (rc) {
497 			bb_error_msg("can't load module %s (%s): %s",
498 				humanly_readable_name(m2),
499 				fn,
500 				moderror(rc)
501 			);
502 			break;
503 		}
504 		m2->flags |= MODULE_FLAG_LOADED;
505 	}
506 
507 	return rc;
508 }
509 
load_modules_dep(void)510 static void load_modules_dep(void)
511 {
512 	struct module_entry *m;
513 	char *colon, *tokens[2];
514 	parser_t *p;
515 
516 	/* Modprobe does not work at all without modules.dep,
517 	 * even if the full module name is given. Returning error here
518 	 * was making us later confuse user with this message:
519 	 * "module /full/path/to/existing/file/module.ko not found".
520 	 * It's better to die immediately, with good message.
521 	 * xfopen_for_read provides that. */
522 	p = config_open2(CONFIG_DEFAULT_DEPMOD_FILE, xfopen_for_read);
523 
524 	while (G.num_unresolved_deps
525 	 && config_read(p, tokens, 2, 1, "# \t", PARSE_NORMAL)
526 	) {
527 		colon = last_char_is(tokens[0], ':');
528 		if (colon == NULL)
529 			continue;
530 		*colon = '\0';
531 
532 		m = moddb_get(&G.db, bb_get_last_path_component_nostrip(tokens[0]));
533 		if (m == NULL)
534 			continue;
535 
536 		/* Optimization... */
537 		if ((m->flags & MODULE_FLAG_LOADED)
538 		 && !(option_mask32 & (OPT_REMOVE | OPT_SHOW_DEPS))
539 		) {
540 			DBG("skip deps of %s, it's already loaded", tokens[0]);
541 			continue;
542 		}
543 
544 		m->flags |= MODULE_FLAG_FOUND_IN_MODDEP;
545 		if ((m->flags & MODULE_FLAG_NEED_DEPS) && (m->deps == NULL)) {
546 			G.num_unresolved_deps--;
547 			llist_add_to(&m->deps, xstrdup(tokens[0]));
548 			if (tokens[1])
549 				string_to_llist(tokens[1], &m->deps, " \t");
550 		} else
551 			DBG("skipping dep line");
552 	}
553 	config_close(p);
554 }
555 
556 int modprobe_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
modprobe_main(int argc UNUSED_PARAM,char ** argv)557 int modprobe_main(int argc UNUSED_PARAM, char **argv)
558 {
559 	int rc;
560 	unsigned opt;
561 	struct module_entry *me;
562 
563 	INIT_G();
564 
565 	opt = getopt32long(argv, "^" INSMOD_OPTS MODPROBE_OPTS "\0" MODPROBE_COMPLEMENTARY,
566 			modprobe_longopts
567 			INSMOD_ARGS
568 	);
569 	argv += optind;
570 
571 	/* Goto modules location */
572 	xchdir(CONFIG_DEFAULT_MODULES_DIR);
573 	uname(&G.uts);
574 	xchdir(G.uts.release);
575 
576 	if (opt & OPT_LIST_ONLY) {
577 		int i;
578 		char *colon, *tokens[2];
579 		parser_t *p = config_open2(CONFIG_DEFAULT_DEPMOD_FILE, xfopen_for_read);
580 
581 		for (i = 0; argv[i]; i++)
582 			replace(argv[i], '-', '_');
583 
584 		while (config_read(p, tokens, 2, 1, "# \t", PARSE_NORMAL)) {
585 			colon = last_char_is(tokens[0], ':');
586 			if (!colon)
587 				continue;
588 			*colon = '\0';
589 			if (!argv[0])
590 				puts(tokens[0]);
591 			else {
592 				char name[MODULE_NAME_LEN];
593 				filename2modname(
594 					bb_get_last_path_component_nostrip(tokens[0]),
595 					name
596 				);
597 				for (i = 0; argv[i]; i++) {
598 					if (fnmatch(argv[i], name, 0) == 0) {
599 						puts(tokens[0]);
600 					}
601 				}
602 			}
603 		}
604 		return EXIT_SUCCESS;
605 	}
606 
607 	/* Yes, for some reason -l ignores -s... */
608 	if (opt & INSMOD_OPT_SYSLOG)
609 		logmode = LOGMODE_SYSLOG;
610 
611 	if (!argv[0]) {
612 		if (opt & OPT_REMOVE) {
613 			/* "modprobe -r" (w/o params).
614 			 * "If name is NULL, all unused modules marked
615 			 * autoclean will be removed".
616 			 */
617 			if (bb_delete_module(NULL, O_NONBLOCK | O_EXCL) != 0)
618 				bb_perror_nomsg_and_die();
619 		}
620 		return EXIT_SUCCESS;
621 	}
622 
623 	/* Retrieve module names of already loaded modules */
624 	{
625 		char *s;
626 		parser_t *parser = config_open2("/proc/modules", fopen_for_read);
627 		while (config_read(parser, &s, 1, 1, "# \t", PARSE_NORMAL & ~PARSE_GREEDY))
628 			get_or_add_modentry(s)->flags |= MODULE_FLAG_LOADED;
629 		config_close(parser);
630 
631 		parser = config_open2("modules.builtin", fopen_for_read);
632 		/* this file contains lines like "kernel/fs/binfmt_script.ko" */
633 		while (config_read(parser, &s, 1, 1, "# \t", PARSE_NORMAL))
634 			get_or_add_modentry(bb_basename(s))->flags |= MODULE_FLAG_BUILTIN;
635 		config_close(parser);
636 	}
637 
638 	if (opt & (OPT_INSERT_ALL | OPT_REMOVE)) {
639 		/* Each argument is a module name */
640 		do {
641 			DBG("adding module %s", *argv);
642 			add_probe(*argv++);
643 		} while (*argv);
644 	} else {
645 		/* First argument is module name, rest are parameters */
646 		DBG("probing just module %s", *argv);
647 		add_probe(argv[0]);
648 #if ENABLE_FEATURE_CMDLINE_MODULE_OPTIONS
649 		G.cmdline_mopts = parse_cmdline_module_options(argv, /*quote_spaces:*/ 1);
650 #endif
651 	}
652 
653 	/* Happens if all requested modules are already loaded */
654 	if (G.probes == NULL)
655 		return EXIT_SUCCESS;
656 
657 	read_config("/etc/modprobe.conf");
658 	read_config("/etc/modprobe.d");
659 	if (ENABLE_FEATURE_MODUTILS_SYMBOLS && G.need_symbols)
660 		read_config("modules.symbols");
661 	load_modules_dep();
662 	if (ENABLE_FEATURE_MODUTILS_ALIAS && G.num_unresolved_deps) {
663 		read_config("modules.alias");
664 		load_modules_dep();
665 	}
666 
667 	/* Handle modprobe.blacklist=module1,module2,... */
668 	if (ENABLE_FEATURE_MODPROBE_BLACKLIST) {
669 		char *options;
670 		char *substr;
671 
672 		options = parse_and_add_kcmdline_module_options(NULL, "modprobe");
673 		while ((substr = strsep(&options, " ")) != NULL) {
674 			char *fn = is_prefixed_with(substr, "blacklist=");
675 			if (!fn)
676 				continue;
677 			while ((substr = strsep(&fn, ",")) != NULL) {
678 				/* blacklist <modulename> */
679 				get_or_add_modentry(substr)->flags |= MODULE_FLAG_BLACKLISTED;
680 				DBG("blacklist: %s", substr);
681 			}
682 		}
683 		/*free(options); - WRONG, strsep may have advanced it */
684 	}
685 
686 	rc = 0;
687 	while ((me = llist_pop(&G.probes)) != NULL) {
688 		if (me->realnames == NULL) {
689 			DBG("probing by module name");
690 			/* This is not an alias. Literal names are blacklisted
691 			 * only if '-b' is given.
692 			 */
693 			if (!(opt & OPT_BLACKLIST)
694 			 || !(me->flags & MODULE_FLAG_BLACKLISTED)
695 			) {
696 				rc |= do_modprobe(me);
697 			}
698 			continue;
699 		}
700 
701 		/* Probe all real names for the alias */
702 		do {
703 			char *realname = llist_pop(&me->realnames);
704 			struct module_entry *m2;
705 
706 			DBG("probing alias %s by realname %s", me->modname, realname);
707 			m2 = get_or_add_modentry(realname);
708 			if (!(m2->flags & MODULE_FLAG_BLACKLISTED)
709 			 && (!(m2->flags & MODULE_FLAG_LOADED)
710 			    || (opt & (OPT_REMOVE | OPT_SHOW_DEPS)))
711 			) {
712 //TODO: we can pass "me" as 2nd param to do_modprobe,
713 //and make do_modprobe emit more meaningful error messages
714 //with alias name included, not just module name alias resolves to.
715 				rc |= do_modprobe(m2);
716 			}
717 			free(realname);
718 		} while (me->realnames != NULL);
719 	}
720 
721 	if (ENABLE_FEATURE_CLEAN_UP)
722 		moddb_free(&G.db);
723 
724 	return (rc != 0);
725 }
726