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 tarball for details.
9 */
10
11/* Note that unlike older versions of modules.dep/depmod (busybox and m-i-t),
12 * we expect the full dependency list to be specified in modules.dep.
13 * Older versions would only export the direct dependency list.
14 */
15#include "libbb.h"
16#include "modutils.h"
17#include <sys/utsname.h>
18#include <fnmatch.h>
19
20//#define DBG(fmt, ...) bb_error_msg("%s: " fmt, __func__, ## __VA_ARGS__)
21#define DBG(...) ((void)0)
22
23//usage:#if !ENABLE_MODPROBE_SMALL
24//usage:#define modprobe_notes_usage
25//usage:	"modprobe can (un)load a stack of modules, passing each module options (when\n"
26//usage:	"loading). modprobe uses a configuration file to determine what option(s) to\n"
27//usage:	"pass each module it loads.\n"
28//usage:	"\n"
29//usage:	"The configuration file is searched (in this order):\n"
30//usage:	"\n"
31//usage:	"    /etc/modprobe.conf (2.6 only)\n"
32//usage:	"    /etc/modules.conf\n"
33//usage:	"    /etc/conf.modules (deprecated)\n"
34//usage:	"\n"
35//usage:	"They all have the same syntax (see below). If none is present, it is\n"
36//usage:	"_not_ an error; each loaded module is then expected to load without\n"
37//usage:	"options. Once a file is found, the others are tested for.\n"
38//usage:	"\n"
39//usage:	"/etc/modules.conf entry format:\n"
40//usage:	"\n"
41//usage:	"  alias <alias_name> <mod_name>\n"
42//usage:	"    Makes it possible to modprobe alias_name, when there is no such module.\n"
43//usage:	"    It makes sense if your mod_name is long, or you want a more representative\n"
44//usage:	"    name for that module (eg. 'scsi' in place of 'aha7xxx').\n"
45//usage:	"    This makes it also possible to use a different set of options (below) for\n"
46//usage:	"    the module and the alias.\n"
47//usage:	"    A module can be aliased more than once.\n"
48//usage:	"\n"
49//usage:	"  options <mod_name|alias_name> <symbol=value...>\n"
50//usage:	"    When loading module mod_name (or the module aliased by alias_name), pass\n"
51//usage:	"    the \"symbol=value\" pairs as option to that module.\n"
52//usage:	"\n"
53//usage:	"Sample /etc/modules.conf file:\n"
54//usage:	"\n"
55//usage:	"  options tulip irq=3\n"
56//usage:	"  alias tulip tulip2\n"
57//usage:	"  options tulip2 irq=4 io=0x308\n"
58//usage:	"\n"
59//usage:	"Other functionality offered by 'classic' modprobe is not available in\n"
60//usage:	"this implementation.\n"
61//usage:	"\n"
62//usage:	"If module options are present both in the config file, and on the command line,\n"
63//usage:	"then the options from the command line will be passed to the module _after_\n"
64//usage:	"the options from the config file. That way, you can have defaults in the config\n"
65//usage:	"file, and override them for a specific usage from the command line.\n"
66//usage:#define modprobe_example_usage
67//usage:       "(with the above /etc/modules.conf):\n\n"
68//usage:       "$ modprobe tulip\n"
69//usage:       "   will load the module 'tulip' with default option 'irq=3'\n\n"
70//usage:       "$ modprobe tulip irq=5\n"
71//usage:       "   will load the module 'tulip' with option 'irq=5', thus overriding the default\n\n"
72//usage:       "$ modprobe tulip2\n"
73//usage:       "   will load the module 'tulip' with default options 'irq=4 io=0x308',\n"
74//usage:       "   which are the default for alias 'tulip2'\n\n"
75//usage:       "$ modprobe tulip2 irq=8\n"
76//usage:       "   will load the module 'tulip' with default options 'irq=4 io=0x308 irq=8',\n"
77//usage:       "   which are the default for alias 'tulip2' overridden by the option 'irq=8'\n\n"
78//usage:       "   from the command line\n\n"
79//usage:       "$ modprobe tulip2 irq=2 io=0x210\n"
80//usage:       "   will load the module 'tulip' with default options 'irq=4 io=0x308 irq=4 io=0x210',\n"
81//usage:       "   which are the default for alias 'tulip2' overridden by the options 'irq=2 io=0x210'\n\n"
82//usage:       "   from the command line\n"
83//usage:
84//usage:#define modprobe_trivial_usage
85//usage:	"[-alrqvs"
86//usage:	IF_FEATURE_MODPROBE_BLACKLIST("b")
87//usage:	"] MODULE [symbol=value]..."
88//usage:#define modprobe_full_usage "\n\n"
89//usage:       "Options:"
90//usage:     "\n	-a	Load multiple MODULEs"
91//usage:     "\n	-l	List (MODULE is a pattern)"
92//usage:     "\n	-r	Remove MODULE (stacks) or do autoclean"
93//usage:     "\n	-q	Quiet"
94//usage:     "\n	-v	Verbose"
95//usage:     "\n	-s	Log to syslog"
96//usage:	IF_FEATURE_MODPROBE_BLACKLIST(
97//usage:     "\n	-b	Apply blacklist to module names too"
98//usage:	)
99//usage:#endif /* !ENABLE_MODPROBE_SMALL */
100
101/* Note that usage text doesn't document various 2.4 options
102 * we pull in through INSMOD_OPTS define */
103
104#define MODPROBE_COMPLEMENTARY "q-v:v-q:l--ar:a--lr:r--al"
105#define MODPROBE_OPTS  "alr" IF_FEATURE_MODPROBE_BLACKLIST("b")
106//#define MODPROBE_COMPLEMENTARY "q-v:v-q:l--acr:a--lr:r--al"
107//#define MODPROBE_OPTS  "acd:lnrt:C:" IF_FEATURE_MODPROBE_BLACKLIST("b")
108enum {
109	MODPROBE_OPT_INSERT_ALL = (INSMOD_OPT_UNUSED << 0), /* a */
110	//MODPROBE_OPT_DUMP_ONLY= (INSMOD_OPT_UNUSED << x), /* c */
111	//MODPROBE_OPT_DIRNAME  = (INSMOD_OPT_UNUSED << x), /* d */
112	MODPROBE_OPT_LIST_ONLY  = (INSMOD_OPT_UNUSED << 1), /* l */
113	//MODPROBE_OPT_SHOW_ONLY= (INSMOD_OPT_UNUSED << x), /* n */
114	MODPROBE_OPT_REMOVE     = (INSMOD_OPT_UNUSED << 2), /* r */
115	//MODPROBE_OPT_RESTRICT = (INSMOD_OPT_UNUSED << x), /* t */
116	//MODPROBE_OPT_VERONLY  = (INSMOD_OPT_UNUSED << x), /* V */
117	//MODPROBE_OPT_CONFIGFILE=(INSMOD_OPT_UNUSED << x), /* C */
118	MODPROBE_OPT_BLACKLIST  = (INSMOD_OPT_UNUSED << 3) * ENABLE_FEATURE_MODPROBE_BLACKLIST,
119};
120
121#define MODULE_FLAG_LOADED              0x0001
122#define MODULE_FLAG_NEED_DEPS           0x0002
123/* "was seen in modules.dep": */
124#define MODULE_FLAG_FOUND_IN_MODDEP     0x0004
125#define MODULE_FLAG_BLACKLISTED         0x0008
126
127struct module_entry { /* I'll call it ME. */
128	unsigned flags;
129	char *modname; /* stripped of /path/, .ext and s/-/_/g */
130	const char *probed_name; /* verbatim as seen on cmdline */
131	char *options; /* options from config files */
132	llist_t *realnames; /* strings. if this module is an alias, */
133	/* real module name is one of these. */
134//Can there really be more than one? Example from real kernel?
135	llist_t *deps; /* strings. modules we depend on */
136};
137
138struct globals {
139	llist_t *db; /* MEs of all modules ever seen (caching for speed) */
140	llist_t *probes; /* MEs of module(s) requested on cmdline */
141	char *cmdline_mopts; /* module options from cmdline */
142	int num_unresolved_deps;
143	/* bool. "Did we have 'symbol:FOO' requested on cmdline?" */
144	smallint need_symbols;
145} FIX_ALIASING;
146#define G (*(struct globals*)&bb_common_bufsiz1)
147#define INIT_G() do { } while (0)
148
149
150static int read_config(const char *path);
151
152static char *gather_options_str(char *opts, const char *append)
153{
154	/* Speed-optimized. We call gather_options_str many times. */
155	if (append) {
156		if (opts == NULL) {
157			opts = xstrdup(append);
158		} else {
159			int optlen = strlen(opts);
160			opts = xrealloc(opts, optlen + strlen(append) + 2);
161			sprintf(opts + optlen, " %s", append);
162		}
163	}
164	return opts;
165}
166
167static struct module_entry *helper_get_module(const char *module, int create)
168{
169	char modname[MODULE_NAME_LEN];
170	struct module_entry *e;
171	llist_t *l;
172
173	filename2modname(module, modname);
174	for (l = G.db; l != NULL; l = l->link) {
175		e = (struct module_entry *) l->data;
176		if (strcmp(e->modname, modname) == 0)
177			return e;
178	}
179	if (!create)
180		return NULL;
181
182	e = xzalloc(sizeof(*e));
183	e->modname = xstrdup(modname);
184	llist_add_to(&G.db, e);
185
186	return e;
187}
188static struct module_entry *get_or_add_modentry(const char *module)
189{
190	return helper_get_module(module, 1);
191}
192static struct module_entry *get_modentry(const char *module)
193{
194	return helper_get_module(module, 0);
195}
196
197static void add_probe(const char *name)
198{
199	struct module_entry *m;
200
201	m = get_or_add_modentry(name);
202	if (!(option_mask32 & MODPROBE_OPT_REMOVE)
203	 && (m->flags & MODULE_FLAG_LOADED)
204	) {
205		DBG("skipping %s, it is already loaded", name);
206		return;
207	}
208
209	DBG("queuing %s", name);
210	m->probed_name = name;
211	m->flags |= MODULE_FLAG_NEED_DEPS;
212	llist_add_to_end(&G.probes, m);
213	G.num_unresolved_deps++;
214	if (ENABLE_FEATURE_MODUTILS_SYMBOLS
215	 && strncmp(m->modname, "symbol:", 7) == 0
216	) {
217		G.need_symbols = 1;
218	}
219}
220
221static int FAST_FUNC config_file_action(const char *filename,
222					struct stat *statbuf UNUSED_PARAM,
223					void *userdata UNUSED_PARAM,
224					int depth UNUSED_PARAM)
225{
226	char *tokens[3];
227	parser_t *p;
228	struct module_entry *m;
229	int rc = TRUE;
230
231	if (bb_basename(filename)[0] == '.')
232		goto error;
233
234	p = config_open2(filename, fopen_for_read);
235	if (p == NULL) {
236		rc = FALSE;
237		goto error;
238	}
239
240	while (config_read(p, tokens, 3, 2, "# \t", PARSE_NORMAL)) {
241//Use index_in_strings?
242		if (strcmp(tokens[0], "alias") == 0) {
243			/* alias <wildcard> <modulename> */
244			llist_t *l;
245			char wildcard[MODULE_NAME_LEN];
246			char *rmod;
247
248			if (tokens[2] == NULL)
249				continue;
250			filename2modname(tokens[1], wildcard);
251
252			for (l = G.probes; l != NULL; l = l->link) {
253				m = (struct module_entry *) l->data;
254				if (fnmatch(wildcard, m->modname, 0) != 0)
255					continue;
256				rmod = filename2modname(tokens[2], NULL);
257				llist_add_to(&m->realnames, rmod);
258
259				if (m->flags & MODULE_FLAG_NEED_DEPS) {
260					m->flags &= ~MODULE_FLAG_NEED_DEPS;
261					G.num_unresolved_deps--;
262				}
263
264				m = get_or_add_modentry(rmod);
265				if (!(m->flags & MODULE_FLAG_NEED_DEPS)) {
266					m->flags |= MODULE_FLAG_NEED_DEPS;
267					G.num_unresolved_deps++;
268				}
269			}
270		} else if (strcmp(tokens[0], "options") == 0) {
271			/* options <modulename> <option...> */
272			if (tokens[2] == NULL)
273				continue;
274			m = get_or_add_modentry(tokens[1]);
275			m->options = gather_options_str(m->options, tokens[2]);
276		} else if (strcmp(tokens[0], "include") == 0) {
277			/* include <filename> */
278			read_config(tokens[1]);
279		} else if (ENABLE_FEATURE_MODPROBE_BLACKLIST
280		 && strcmp(tokens[0], "blacklist") == 0
281		) {
282			/* blacklist <modulename> */
283			get_or_add_modentry(tokens[1])->flags |= MODULE_FLAG_BLACKLISTED;
284		}
285	}
286	config_close(p);
287 error:
288	return rc;
289}
290
291static int read_config(const char *path)
292{
293	return recursive_action(path, ACTION_RECURSE | ACTION_QUIET,
294				config_file_action, NULL, NULL, 1);
295}
296
297static const char *humanly_readable_name(struct module_entry *m)
298{
299	/* probed_name may be NULL. modname always exists. */
300	return m->probed_name ? m->probed_name : m->modname;
301}
302
303static char *parse_and_add_kcmdline_module_options(char *options, const char *modulename)
304{
305	char *kcmdline_buf;
306	char *kcmdline;
307	char *kptr;
308	int len;
309
310	kcmdline_buf = xmalloc_open_read_close("/proc/cmdline", NULL);
311	if (!kcmdline_buf)
312		return options;
313
314	kcmdline = kcmdline_buf;
315	len = strlen(modulename);
316	while ((kptr = strsep(&kcmdline, "\n\t ")) != NULL) {
317		if (strncmp(modulename, kptr, len) != 0)
318			continue;
319		kptr += len;
320		if (*kptr != '.')
321			continue;
322		/* It is "modulename.xxxx" */
323		kptr++;
324		if (strchr(kptr, '=') != NULL) {
325			/* It is "modulename.opt=[val]" */
326			options = gather_options_str(options, kptr);
327		}
328	}
329	free(kcmdline_buf);
330
331	return options;
332}
333
334/* Return: similar to bb_init_module:
335 * 0 on success,
336 * -errno on open/read error,
337 * errno on init_module() error
338 */
339/* NB: INSMOD_OPT_SILENT bit suppresses ONLY non-existent modules,
340 * not deleted ones (those are still listed in modules.dep).
341 * module-init-tools version 3.4:
342 * # modprobe bogus
343 * FATAL: Module bogus not found. [exitcode 1]
344 * # modprobe -q bogus            [silent, exitcode still 1]
345 * but:
346 * # rm kernel/drivers/net/dummy.ko
347 * # modprobe -q dummy
348 * FATAL: Could not open '/lib/modules/xxx/kernel/drivers/net/dummy.ko': No such file or directory
349 * [exitcode 1]
350 */
351static int do_modprobe(struct module_entry *m)
352{
353	struct module_entry *m2 = m2; /* for compiler */
354	char *fn, *options;
355	int rc, first;
356	llist_t *l;
357
358	if (!(m->flags & MODULE_FLAG_FOUND_IN_MODDEP)) {
359		if (!(option_mask32 & INSMOD_OPT_SILENT))
360			bb_error_msg("module %s not found in modules.dep",
361				humanly_readable_name(m));
362		return -ENOENT;
363	}
364	DBG("do_modprob'ing %s", m->modname);
365
366	if (!(option_mask32 & MODPROBE_OPT_REMOVE))
367		m->deps = llist_rev(m->deps);
368
369	for (l = m->deps; l != NULL; l = l->link)
370		DBG("dep: %s", l->data);
371
372	first = 1;
373	rc = 0;
374	while (m->deps) {
375		rc = 0;
376		fn = llist_pop(&m->deps); /* we leak it */
377		m2 = get_or_add_modentry(fn);
378
379		if (option_mask32 & MODPROBE_OPT_REMOVE) {
380			/* modprobe -r */
381			if (m2->flags & MODULE_FLAG_LOADED) {
382				rc = bb_delete_module(m2->modname, O_NONBLOCK | O_EXCL);
383				if (rc) {
384					if (first) {
385						bb_error_msg("can't unload module %s: %s",
386							humanly_readable_name(m2),
387							moderror(rc));
388						break;
389					}
390				} else {
391					m2->flags &= ~MODULE_FLAG_LOADED;
392				}
393			}
394			/* do not error out if *deps* fail to unload */
395			first = 0;
396			continue;
397		}
398
399		if (m2->flags & MODULE_FLAG_LOADED) {
400			DBG("%s is already loaded, skipping", fn);
401			continue;
402		}
403
404		options = m2->options;
405		m2->options = NULL;
406		options = parse_and_add_kcmdline_module_options(options, m2->modname);
407		if (m == m2)
408			options = gather_options_str(options, G.cmdline_mopts);
409		rc = bb_init_module(fn, options);
410		DBG("loaded %s '%s', rc:%d", fn, options, rc);
411		if (rc == EEXIST)
412			rc = 0;
413		free(options);
414		if (rc) {
415			bb_error_msg("can't load module %s (%s): %s",
416				humanly_readable_name(m2),
417				fn,
418				moderror(rc)
419			);
420			break;
421		}
422		m2->flags |= MODULE_FLAG_LOADED;
423	}
424
425	return rc;
426}
427
428static void load_modules_dep(void)
429{
430	struct module_entry *m;
431	char *colon, *tokens[2];
432	parser_t *p;
433
434	/* Modprobe does not work at all without modules.dep,
435	 * even if the full module name is given. Returning error here
436	 * was making us later confuse user with this message:
437	 * "module /full/path/to/existing/file/module.ko not found".
438	 * It's better to die immediately, with good message.
439	 * xfopen_for_read provides that. */
440	p = config_open2(CONFIG_DEFAULT_DEPMOD_FILE, xfopen_for_read);
441
442	while (G.num_unresolved_deps
443	 && config_read(p, tokens, 2, 1, "# \t", PARSE_NORMAL)
444	) {
445		colon = last_char_is(tokens[0], ':');
446		if (colon == NULL)
447			continue;
448		*colon = 0;
449
450		m = get_modentry(tokens[0]);
451		if (m == NULL)
452			continue;
453
454		/* Optimization... */
455		if ((m->flags & MODULE_FLAG_LOADED)
456		 && !(option_mask32 & MODPROBE_OPT_REMOVE)
457		) {
458			DBG("skip deps of %s, it's already loaded", tokens[0]);
459			continue;
460		}
461
462		m->flags |= MODULE_FLAG_FOUND_IN_MODDEP;
463		if ((m->flags & MODULE_FLAG_NEED_DEPS) && (m->deps == NULL)) {
464			G.num_unresolved_deps--;
465			llist_add_to(&m->deps, xstrdup(tokens[0]));
466			if (tokens[1])
467				string_to_llist(tokens[1], &m->deps, " \t");
468		} else
469			DBG("skipping dep line");
470	}
471	config_close(p);
472}
473
474int modprobe_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
475int modprobe_main(int argc UNUSED_PARAM, char **argv)
476{
477	struct utsname uts;
478	int rc;
479	unsigned opt;
480	struct module_entry *me;
481
482	opt_complementary = MODPROBE_COMPLEMENTARY;
483	opt = getopt32(argv, INSMOD_OPTS MODPROBE_OPTS INSMOD_ARGS);
484	argv += optind;
485
486	/* Goto modules location */
487	xchdir(CONFIG_DEFAULT_MODULES_DIR);
488	uname(&uts);
489	xchdir(uts.release);
490
491	if (opt & MODPROBE_OPT_LIST_ONLY) {
492		char name[MODULE_NAME_LEN];
493		char *colon, *tokens[2];
494		parser_t *p = config_open2(CONFIG_DEFAULT_DEPMOD_FILE, xfopen_for_read);
495
496		while (config_read(p, tokens, 2, 1, "# \t", PARSE_NORMAL)) {
497			colon = last_char_is(tokens[0], ':');
498			if (!colon)
499				continue;
500			*colon = '\0';
501			filename2modname(tokens[0], name);
502			if (!argv[0])
503				puts(tokens[0]);
504			else {
505				int i;
506				for (i = 0; argv[i]; i++) {
507					if (fnmatch(argv[i], name, 0) == 0) {
508						puts(tokens[0]);
509					}
510				}
511			}
512		}
513		return EXIT_SUCCESS;
514	}
515
516	/* Yes, for some reason -l ignores -s... */
517	if (opt & INSMOD_OPT_SYSLOG)
518		logmode = LOGMODE_SYSLOG;
519
520	if (!argv[0]) {
521		if (opt & MODPROBE_OPT_REMOVE) {
522			/* "modprobe -r" (w/o params).
523			 * "If name is NULL, all unused modules marked
524			 * autoclean will be removed".
525			 */
526			if (bb_delete_module(NULL, O_NONBLOCK | O_EXCL) != 0)
527				bb_perror_msg_and_die("rmmod");
528		}
529		return EXIT_SUCCESS;
530	}
531
532	/* Retrieve module names of already loaded modules */
533	{
534		char *s;
535		parser_t *parser = config_open2("/proc/modules", fopen_for_read);
536		while (config_read(parser, &s, 1, 1, "# \t", PARSE_NORMAL & ~PARSE_GREEDY))
537			get_or_add_modentry(s)->flags |= MODULE_FLAG_LOADED;
538		config_close(parser);
539	}
540
541	if (opt & (MODPROBE_OPT_INSERT_ALL | MODPROBE_OPT_REMOVE)) {
542		/* Each argument is a module name */
543		do {
544			DBG("adding module %s", *argv);
545			add_probe(*argv++);
546		} while (*argv);
547	} else {
548		/* First argument is module name, rest are parameters */
549		DBG("probing just module %s", *argv);
550		add_probe(argv[0]);
551		G.cmdline_mopts = parse_cmdline_module_options(argv);
552	}
553
554	/* Happens if all requested modules are already loaded */
555	if (G.probes == NULL)
556		return EXIT_SUCCESS;
557
558	read_config("/etc/modprobe.conf");
559	read_config("/etc/modprobe.d");
560	if (ENABLE_FEATURE_MODUTILS_SYMBOLS && G.need_symbols)
561		read_config("modules.symbols");
562	load_modules_dep();
563	if (ENABLE_FEATURE_MODUTILS_ALIAS && G.num_unresolved_deps) {
564		read_config("modules.alias");
565		load_modules_dep();
566	}
567
568	rc = 0;
569	while ((me = llist_pop(&G.probes)) != NULL) {
570		if (me->realnames == NULL) {
571			DBG("probing by module name");
572			/* This is not an alias. Literal names are blacklisted
573			 * only if '-b' is given.
574			 */
575			if (!(opt & MODPROBE_OPT_BLACKLIST)
576			 || !(me->flags & MODULE_FLAG_BLACKLISTED)
577			) {
578				rc |= do_modprobe(me);
579			}
580			continue;
581		}
582
583		/* Probe all real names for the alias */
584		do {
585			char *realname = llist_pop(&me->realnames);
586			struct module_entry *m2;
587
588			DBG("probing alias %s by realname %s", me->modname, realname);
589			m2 = get_or_add_modentry(realname);
590			if (!(m2->flags & MODULE_FLAG_BLACKLISTED)
591			 && (!(m2->flags & MODULE_FLAG_LOADED)
592			    || (opt & MODPROBE_OPT_REMOVE))
593			) {
594//TODO: we can pass "me" as 2nd param to do_modprobe,
595//and make do_modprobe emit more meaningful error messages
596//with alias name included, not just module name alias resolves to.
597				rc |= do_modprobe(m2);
598			}
599			free(realname);
600		} while (me->realnames != NULL);
601	}
602
603	return (rc != 0);
604}
605