1 /* vi: set sw=4 ts=4: */
2 /*
3  * simplified modprobe
4  *
5  * Copyright (c) 2008 Vladimir Dronnikov
6  * Copyright (c) 2008 Bernhard Reutner-Fischer (initial depmod code)
7  *
8  * Licensed under GPLv2, see file LICENSE in this source tree.
9  */
10 
11 /* modprobe-small configs are defined in Config.src to ensure better
12  * "make config" order */
13 
14 //applet:IF_LSMOD(   IF_MODPROBE_SMALL(APPLET_NOEXEC( lsmod,    lsmod,    BB_DIR_SBIN, BB_SUID_DROP, lsmod   )))
15 //applet:IF_MODPROBE(IF_MODPROBE_SMALL(APPLET_NOEXEC( modprobe, modprobe, BB_DIR_SBIN, BB_SUID_DROP, modprobe)))
16 //                                     APPLET_ODDNAME:name      main      location     suid_type     help
17 //applet:IF_DEPMOD(  IF_MODPROBE_SMALL(APPLET_ODDNAME(depmod,   modprobe, BB_DIR_SBIN, BB_SUID_DROP, depmod  )))
18 //applet:IF_INSMOD(  IF_MODPROBE_SMALL(APPLET_NOEXEC( insmod,   modprobe, BB_DIR_SBIN, BB_SUID_DROP, insmod  )))
19 //applet:IF_RMMOD(   IF_MODPROBE_SMALL(APPLET_NOEXEC( rmmod,    modprobe, BB_DIR_SBIN, BB_SUID_DROP, rmmod   )))
20 /* noexec speeds up boot with many modules loaded (need SH_STANDALONE=y) */
21 /* I measured about ~5 times faster insmod */
22 /* depmod is not noexec, it runs longer and benefits from memory trimming via exec */
23 
24 //kbuild:lib-$(CONFIG_MODPROBE_SMALL) += modprobe-small.o
25 
26 #include "libbb.h"
27 /* After libbb.h, since it needs sys/types.h on some systems */
28 #include <sys/utsname.h> /* uname() */
29 #include <fnmatch.h>
30 #include <sys/syscall.h>
31 
32 #define init_module(mod, len, opts) syscall(__NR_init_module, mod, len, opts)
33 #define delete_module(mod, flags) syscall(__NR_delete_module, mod, flags)
34 #ifdef __NR_finit_module
35 # define finit_module(fd, uargs, flags) syscall(__NR_finit_module, fd, uargs, flags)
36 #endif
37 /* linux/include/linux/module.h has limit of 64 chars on module names */
38 #undef MODULE_NAME_LEN
39 #define MODULE_NAME_LEN 64
40 
41 
42 #if 1
43 # define dbg1_error_msg(...) ((void)0)
44 # define dbg2_error_msg(...) ((void)0)
45 #else
46 # define dbg1_error_msg(...) bb_error_msg(__VA_ARGS__)
47 # define dbg2_error_msg(...) bb_error_msg(__VA_ARGS__)
48 #endif
49 
50 #define DEPFILE_BB CONFIG_DEFAULT_DEPMOD_FILE".bb"
51 
52 //usage:#if ENABLE_MODPROBE_SMALL
53 
54 //usage:#define lsmod_trivial_usage
55 //usage:       ""
56 //usage:#define lsmod_full_usage "\n\n"
57 //usage:       "List loaded kernel modules"
58 
59 //usage:#endif
60 
61 #if ENABLE_LSMOD
62 int lsmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
lsmod_main(int argc UNUSED_PARAM,char ** argv UNUSED_PARAM)63 int lsmod_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
64 {
65 	xprint_and_close_file(xfopen_for_read("/proc/modules"));
66 	return EXIT_SUCCESS;
67 }
68 #endif
69 
70 /* Num of applets that use modprobe_main() entry point. */
71 /* lsmod is not here. */
72 #define MOD_APPLET_CNT (ENABLE_MODPROBE + ENABLE_DEPMOD + ENABLE_INSMOD + ENABLE_RMMOD)
73 
74 /* Do not bother if MODPROBE_SMALL=y but no applets selected. */
75 /* The rest of the file is in this if block. */
76 #if MOD_APPLET_CNT > 0
77 
78 #define ONLY_APPLET (MOD_APPLET_CNT == 1)
79 #define is_modprobe (ENABLE_MODPROBE && (ONLY_APPLET || applet_name[0] == 'm'))
80 #define is_depmod   (ENABLE_DEPMOD   && (ONLY_APPLET || applet_name[0] == 'd'))
81 #define is_insmod   (ENABLE_INSMOD   && (ONLY_APPLET || applet_name[0] == 'i'))
82 #define is_rmmod    (ENABLE_RMMOD    && (ONLY_APPLET || applet_name[0] == 'r'))
83 
84 enum {
85 	DEPMOD_OPT_n = (1 << 0), /* dry-run, print to stdout */
86 	OPT_q = (1 << 0), /* be quiet */
87 	OPT_r = (1 << 1), /* module removal instead of loading */
88 };
89 
90 typedef struct module_info {
91 	char *pathname;
92 	char *aliases;
93 	char *deps;
94 	smallint open_read_failed;
95 } module_info;
96 
97 /*
98  * GLOBALS
99  */
100 struct globals {
101 	module_info *modinfo;
102 	char *module_load_options;
103 	smallint dep_bb_seen;
104 	smallint wrote_dep_bb_ok;
105 	unsigned module_count;
106 	int module_found_idx;
107 	unsigned stringbuf_idx;
108 	unsigned stringbuf_size;
109 	char *stringbuf; /* some modules have lots of stuff */
110 	/* for example, drivers/media/video/saa7134/saa7134.ko */
111 	/* therefore having a fixed biggish buffer is not wise */
112 };
113 #define G (*ptr_to_globals)
114 #define modinfo             (G.modinfo            )
115 #define dep_bb_seen         (G.dep_bb_seen        )
116 #define wrote_dep_bb_ok     (G.wrote_dep_bb_ok    )
117 #define module_count        (G.module_count       )
118 #define module_found_idx    (G.module_found_idx   )
119 #define module_load_options (G.module_load_options)
120 #define stringbuf_idx       (G.stringbuf_idx      )
121 #define stringbuf_size      (G.stringbuf_size     )
122 #define stringbuf           (G.stringbuf          )
123 #define INIT_G() do { \
124 	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
125 } while (0)
126 
append(const char * s)127 static void append(const char *s)
128 {
129 	unsigned len = strlen(s);
130 	if (stringbuf_idx + len + 15 > stringbuf_size) {
131 		stringbuf_size = stringbuf_idx + len + 127;
132 		dbg2_error_msg("grow stringbuf to %u", stringbuf_size);
133 		stringbuf = xrealloc(stringbuf, stringbuf_size);
134 	}
135 	memcpy(stringbuf + stringbuf_idx, s, len);
136 	stringbuf_idx += len;
137 }
138 
appendc(char c)139 static void appendc(char c)
140 {
141 	/* We appendc() only after append(), + 15 trick in append()
142 	 * makes it unnecessary to check for overflow here */
143 	stringbuf[stringbuf_idx++] = c;
144 }
145 
bksp(void)146 static void bksp(void)
147 {
148 	if (stringbuf_idx)
149 		stringbuf_idx--;
150 }
151 
reset_stringbuf(void)152 static void reset_stringbuf(void)
153 {
154 	stringbuf_idx = 0;
155 }
156 
copy_stringbuf(void)157 static char* copy_stringbuf(void)
158 {
159 	char *copy = xzalloc(stringbuf_idx + 1); /* terminating NUL */
160 	return memcpy(copy, stringbuf, stringbuf_idx);
161 }
162 
find_keyword(char * ptr,size_t len,const char * word)163 static char* find_keyword(char *ptr, size_t len, const char *word)
164 {
165 	if (!ptr) /* happens if xmalloc_open_zipped_read_close cannot read it */
166 		return NULL;
167 
168 	len -= strlen(word) - 1;
169 	while ((ssize_t)len > 0) {
170 		char *old = ptr;
171 		char *after_word;
172 
173 		/* search for the first char in word */
174 		ptr = memchr(ptr, word[0], len);
175 		if (ptr == NULL) /* no occurrence left, done */
176 			break;
177 		after_word = is_prefixed_with(ptr, word);
178 		if (after_word)
179 			return after_word; /* found, return ptr past it */
180 		++ptr;
181 		len -= (ptr - old);
182 	}
183 	return NULL;
184 }
185 
replace(char * s,char what,char with)186 static void replace(char *s, char what, char with)
187 {
188 	while (*s) {
189 		if (what == *s)
190 			*s = with;
191 		++s;
192 	}
193 }
194 
filename2modname(const char * filename,char * modname)195 static char *filename2modname(const char *filename, char *modname)
196 {
197 	int i;
198 	const char *from;
199 
200 	// Disabled since otherwise "modprobe dir/name" would work
201 	// as if it is "modprobe name". It is unclear why
202 	// 'basenamization' was here in the first place.
203 	//from = bb_get_last_path_component_nostrip(filename);
204 	from = filename;
205 	for (i = 0; i < (MODULE_NAME_LEN-1) && from[i] != '\0' && from[i] != '.'; i++)
206 		modname[i] = (from[i] == '-') ? '_' : from[i];
207 	modname[i] = '\0';
208 
209 	return modname;
210 }
211 
pathname_matches_modname(const char * pathname,const char * modname)212 static int pathname_matches_modname(const char *pathname, const char *modname)
213 {
214 	int r;
215 	char name[MODULE_NAME_LEN];
216 	filename2modname(bb_get_last_path_component_nostrip(pathname), name);
217 	r = (strcmp(name, modname) == 0);
218 	return r;
219 }
220 
221 /* Take "word word", return malloced "word",NUL,"word",NUL,NUL */
str_2_list(const char * str)222 static char* str_2_list(const char *str)
223 {
224 	int len = strlen(str) + 1;
225 	char *dst = xmalloc(len + 1);
226 
227 	dst[len] = '\0';
228 	memcpy(dst, str, len);
229 //TODO: protect against 2+ spaces: "word  word"
230 	replace(dst, ' ', '\0');
231 	return dst;
232 }
233 
234 /* We use error numbers in a loose translation... */
moderror(int err)235 static const char *moderror(int err)
236 {
237 	switch (err) {
238 	case ENOEXEC:
239 		return "invalid module format";
240 	case ENOENT:
241 		return "unknown symbol in module or invalid parameter";
242 	case ESRCH:
243 		return "module has wrong symbol version";
244 	case EINVAL: /* "invalid parameter" */
245 		return "unknown symbol in module or invalid parameter"
246 		+ sizeof("unknown symbol in module or");
247 	default:
248 		return strerror(err);
249 	}
250 }
251 
load_module(const char * fname,const char * options)252 static int load_module(const char *fname, const char *options)
253 {
254 #if 1
255 	int r;
256 	size_t len = MAXINT(ssize_t);
257 	char *module_image;
258 
259 	if (!options)
260 		options = "";
261 
262 	dbg1_error_msg("load_module('%s','%s')", fname, options);
263 
264 	/*
265 	 * First we try finit_module if available.  Some kernels are configured
266 	 * to only allow loading of modules off of secure storage (like a read-
267 	 * only rootfs) which needs the finit_module call.  If it fails, we fall
268 	 * back to normal module loading to support compressed modules.
269 	 */
270 	r = 1;
271 # ifdef __NR_finit_module
272 	{
273 		int fd = open(fname, O_RDONLY | O_CLOEXEC);
274 		if (fd >= 0) {
275 			r = finit_module(fd, options, 0) != 0;
276 			close(fd);
277 		}
278 	}
279 # endif
280 	if (r != 0) {
281 		module_image = xmalloc_open_zipped_read_close(fname, &len);
282 		r = (!module_image || init_module(module_image, len, options) != 0);
283 		free(module_image);
284 	}
285 
286 	dbg1_error_msg("load_module:%d", r);
287 	return r; /* 0 = success */
288 #else
289 	/* For testing */
290 	dbg1_error_msg("load_module('%s','%s')", fname, options);
291 	return 1;
292 #endif
293 }
294 
295 /* Returns !0 if open/read was unsuccessful */
parse_module(module_info * info,const char * pathname)296 static int parse_module(module_info *info, const char *pathname)
297 {
298 	char *module_image;
299 	char *ptr;
300 	size_t len;
301 	size_t pos;
302 	dbg1_error_msg("parse_module('%s')", pathname);
303 
304 	/* Read (possibly compressed) module */
305 	errno = 0;
306 	len = 64 * 1024 * 1024; /* 64 Mb at most */
307 	module_image = xmalloc_open_zipped_read_close(pathname, &len);
308 	/* module_image == NULL is ok here, find_keyword handles it */
309 //TODO: optimize redundant module body reads
310 
311 	/* "alias1 symbol:sym1 alias2 symbol:sym2" */
312 	reset_stringbuf();
313 	pos = 0;
314 	while (1) {
315 		unsigned start = stringbuf_idx;
316 		ptr = find_keyword(module_image + pos, len - pos, "alias=");
317 		if (!ptr) {
318 			ptr = find_keyword(module_image + pos, len - pos, "__ksymtab_");
319 			if (!ptr)
320 				break;
321 			/* DOCME: __ksymtab_gpl and __ksymtab_strings occur
322 			 * in many modules. What do they mean? */
323 			if (strcmp(ptr, "gpl") == 0 || strcmp(ptr, "strings") == 0)
324 				goto skip;
325 			dbg2_error_msg("alias:'symbol:%s'", ptr);
326 			append("symbol:");
327 		} else {
328 			dbg2_error_msg("alias:'%s'", ptr);
329 		}
330 		append(ptr);
331 		appendc(' ');
332 		/*
333 		 * Don't add redundant aliases, such as:
334 		 * libcrc32c.ko symbol:crc32c symbol:crc32c
335 		 */
336 		if (start) { /* "if we aren't the first alias" */
337 			char *found, *last;
338 			stringbuf[stringbuf_idx] = '\0';
339 			last = stringbuf + start;
340 			/*
341 			 * String at last-1 is " symbol:crc32c "
342 			 * (with both leading and trailing spaces).
343 			 */
344 			if (strncmp(stringbuf, last, stringbuf_idx - start) == 0)
345 				/* First alias matches us */
346 				found = stringbuf;
347 			else
348 				/* Does any other alias match? */
349 				found = strstr(stringbuf, last-1);
350 			if (found < last-1) {
351 				/* There is absolutely the same string before us */
352 				dbg2_error_msg("redundant:'%s'", last);
353 				stringbuf_idx = start;
354 				goto skip;
355 			}
356 		}
357  skip:
358 		pos = (ptr - module_image);
359 	}
360 	bksp(); /* remove last ' ' */
361 	info->aliases = copy_stringbuf();
362 	replace(info->aliases, '-', '_');
363 
364 	/* "dependency1 depandency2" */
365 	reset_stringbuf();
366 	ptr = find_keyword(module_image, len, "depends=");
367 	if (ptr && *ptr) {
368 		replace(ptr, ',', ' ');
369 		replace(ptr, '-', '_');
370 		dbg2_error_msg("dep:'%s'", ptr);
371 		append(ptr);
372 	}
373 	free(module_image);
374 	info->deps = copy_stringbuf();
375 
376 	info->open_read_failed = (module_image == NULL);
377 	return info->open_read_failed;
378 }
379 
fileAction(struct recursive_state * state,const char * pathname,struct stat * sb UNUSED_PARAM)380 static FAST_FUNC int fileAction(struct recursive_state *state,
381 		const char *pathname,
382 		struct stat *sb UNUSED_PARAM)
383 {
384 	const char *modname_to_match = state->userData;
385 	int cur;
386 	const char *fname;
387 	bool is_remove = (ENABLE_RMMOD && ONLY_APPLET)
388 		|| ((ENABLE_RMMOD || ENABLE_MODPROBE) && (option_mask32 & OPT_r));
389 
390 	pathname += 2; /* skip "./" */
391 	fname = bb_get_last_path_component_nostrip(pathname);
392 	if (!strrstr(fname, ".ko")) {
393 		dbg1_error_msg("'%s' is not a module", pathname);
394 		return TRUE; /* not a module, continue search */
395 	}
396 
397 	cur = module_count++;
398 	modinfo = xrealloc_vector(modinfo, 12, cur);
399 	modinfo[cur].pathname = xstrdup(pathname);
400 	/*modinfo[cur].aliases = NULL; - xrealloc_vector did it */
401 	/*modinfo[cur+1].pathname = NULL;*/
402 
403 	if (!pathname_matches_modname(fname, modname_to_match)) {
404 		dbg1_error_msg("'%s' module name doesn't match", pathname);
405 		return TRUE; /* module name doesn't match, continue search */
406 	}
407 
408 	dbg1_error_msg("'%s' module name matches", pathname);
409 	module_found_idx = cur;
410 	if (parse_module(&modinfo[cur], pathname) != 0)
411 		return TRUE; /* failed to open/read it, no point in trying loading */
412 
413 	if (!is_remove) {
414 		if (load_module(pathname, module_load_options) == 0) {
415 			/* Load was successful, there is nothing else to do.
416 			 * This can happen ONLY for "top-level" module load,
417 			 * not a dep, because deps don't do dirscan. */
418 			exit(EXIT_SUCCESS);
419 		}
420 	}
421 
422 	return TRUE;
423 }
424 
load_dep_bb(void)425 static int load_dep_bb(void)
426 {
427 	char *line;
428 	FILE *fp = fopen_for_read(DEPFILE_BB);
429 
430 	if (!fp)
431 		return 0;
432 
433 	dep_bb_seen = 1;
434 	dbg1_error_msg("loading "DEPFILE_BB);
435 
436 	/* Why? There is a rare scenario: we did not find modprobe.dep.bb,
437 	 * we scanned the dir and found no module by name, then we search
438 	 * for alias (full scan), and we decided to generate modprobe.dep.bb.
439 	 * But we see modprobe.dep.bb.new! Other modprobe is at work!
440 	 * We wait and other modprobe renames it to modprobe.dep.bb.
441 	 * Now we can use it.
442 	 * But we already have modinfo[] filled, and "module_count = 0"
443 	 * makes us start anew. Yes, we leak modinfo[].xxx pointers -
444 	 * there is not much of data there anyway. */
445 	module_count = 0;
446 	memset(&modinfo[0], 0, sizeof(modinfo[0]));
447 
448 	while ((line = xmalloc_fgetline(fp)) != NULL) {
449 		char* space;
450 		char* linebuf;
451 		int cur;
452 
453 		if (!line[0]) {
454 			free(line);
455 			continue;
456 		}
457 		space = strchrnul(line, ' ');
458 		cur = module_count++;
459 		modinfo = xrealloc_vector(modinfo, 12, cur);
460 		/*modinfo[cur+1].pathname = NULL; - xrealloc_vector did it */
461 		modinfo[cur].pathname = line; /* we take ownership of malloced block here */
462 		if (*space)
463 			*space++ = '\0';
464 		modinfo[cur].aliases = space;
465 		linebuf = xmalloc_fgetline(fp);
466 		modinfo[cur].deps = linebuf ? linebuf : xzalloc(1);
467 		if (modinfo[cur].deps[0]) {
468 			/* deps are not "", so next line must be empty */
469 			line = xmalloc_fgetline(fp);
470 			/* Refuse to work with damaged config file */
471 			if (line && line[0])
472 				bb_error_msg_and_die("error in %s at '%s'", DEPFILE_BB, line);
473 			free(line);
474 		}
475 	}
476 	return 1;
477 }
478 
start_dep_bb_writeout(void)479 static int start_dep_bb_writeout(void)
480 {
481 	int fd;
482 
483 	/* depmod -n: write result to stdout */
484 	if (is_depmod && (option_mask32 & DEPMOD_OPT_n))
485 		return STDOUT_FILENO;
486 
487 	fd = open(DEPFILE_BB".new", O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 0644);
488 	if (fd < 0) {
489 		if (errno == EEXIST) {
490 			int count = 5 * 20;
491 			dbg1_error_msg(DEPFILE_BB".new exists, waiting for "DEPFILE_BB);
492 			while (1) {
493 				usleep(1000*1000 / 20);
494 				if (load_dep_bb()) {
495 					dbg1_error_msg(DEPFILE_BB" appeared");
496 					return -2; /* magic number */
497 				}
498 				if (!--count)
499 					break;
500 			}
501 			bb_error_msg("deleting stale %s", DEPFILE_BB".new");
502 			fd = open_or_warn(DEPFILE_BB".new", O_WRONLY | O_CREAT | O_TRUNC);
503 		}
504 	}
505 	dbg1_error_msg("opened "DEPFILE_BB".new:%d", fd);
506 	return fd;
507 }
508 
write_out_dep_bb(int fd)509 static void write_out_dep_bb(int fd)
510 {
511 	int i;
512 	FILE *fp;
513 
514 	/* We want good error reporting. fdprintf is not good enough. */
515 	fp = xfdopen_for_write(fd);
516 	i = 0;
517 	while (modinfo[i].pathname) {
518 		fprintf(fp, "%s%s%s\n" "%s%s\n",
519 			modinfo[i].pathname, modinfo[i].aliases[0] ? " " : "", modinfo[i].aliases,
520 			modinfo[i].deps, modinfo[i].deps[0] ? "\n" : "");
521 		i++;
522 	}
523 	/* Badly formatted depfile is a no-no. Be paranoid. */
524 	errno = 0;
525 	if (ferror(fp) | fclose(fp)) /* | instead of || is intended */
526 		goto err;
527 
528 	if (fd == STDOUT_FILENO) /* it was depmod -n */
529 		goto ok;
530 
531 	if (rename(DEPFILE_BB".new", DEPFILE_BB) != 0) {
532  err:
533 		bb_perror_msg("can't create '%s'", DEPFILE_BB);
534 		unlink(DEPFILE_BB".new");
535 	} else {
536  ok:
537 		wrote_dep_bb_ok = 1;
538 		dbg1_error_msg("created "DEPFILE_BB);
539 	}
540 }
541 
find_alias(const char * alias)542 static module_info** find_alias(const char *alias)
543 {
544 	int i;
545 	int dep_bb_fd;
546 	int infoidx;
547 	module_info **infovec;
548 	dbg1_error_msg("find_alias('%s')", alias);
549 
550  try_again:
551 	/* First try to find by name (cheaper) */
552 	i = 0;
553 	while (modinfo[i].pathname) {
554 		if (pathname_matches_modname(modinfo[i].pathname, alias)) {
555 			dbg1_error_msg("found '%s' in module '%s'",
556 					alias, modinfo[i].pathname);
557 			if (!modinfo[i].aliases) {
558 				parse_module(&modinfo[i], modinfo[i].pathname);
559 			}
560 			infovec = xzalloc(2 * sizeof(infovec[0]));
561 			infovec[0] = &modinfo[i];
562 			return infovec;
563 		}
564 		i++;
565 	}
566 
567 	/* Ok, we definitely have to scan module bodies. This is a good
568 	 * moment to generate modprobe.dep.bb, if it does not exist yet */
569 	dep_bb_fd = dep_bb_seen ? -1 : start_dep_bb_writeout();
570 	if (dep_bb_fd == -2) /* modprobe.dep.bb appeared? */
571 		goto try_again;
572 
573 	/* Scan all module bodies, extract modinfo (it contains aliases) */
574 	i = 0;
575 	infoidx = 0;
576 	infovec = NULL;
577 	while (modinfo[i].pathname) {
578 		char *desc, *s;
579 		if (!modinfo[i].aliases) {
580 			parse_module(&modinfo[i], modinfo[i].pathname);
581 		}
582 		/* "alias1 symbol:sym1 alias2 symbol:sym2" */
583 		desc = str_2_list(modinfo[i].aliases);
584 		/* Does matching substring exist? */
585 		for (s = desc; *s; s += strlen(s) + 1) {
586 			/* Aliases in module bodies can be defined with
587 			 * shell patterns. Example:
588 			 * "pci:v000010DEd000000D9sv*sd*bc*sc*i*".
589 			 * Plain strcmp() won't catch that */
590 			if (fnmatch(s, alias, 0) == 0) {
591 				dbg1_error_msg("found alias '%s' in module '%s'",
592 						alias, modinfo[i].pathname);
593 				infovec = xrealloc_vector(infovec, 1, infoidx);
594 				infovec[infoidx++] = &modinfo[i];
595 				break;
596 			}
597 		}
598 		free(desc);
599 		i++;
600 	}
601 
602 	/* Create module.dep.bb if needed */
603 	if (dep_bb_fd >= 0) {
604 		write_out_dep_bb(dep_bb_fd);
605 	}
606 
607 	dbg1_error_msg("find_alias '%s' returns %d results", alias, infoidx);
608 	return infovec;
609 }
610 
611 #if ENABLE_FEATURE_MODPROBE_SMALL_CHECK_ALREADY_LOADED
612 // TODO: open only once, invent config_rewind()
already_loaded(const char * name)613 static int already_loaded(const char *name)
614 {
615 	int ret;
616 	char *line;
617 	FILE *fp;
618 
619 	ret = 5 * 2;
620  again:
621 	fp = fopen_for_read("/proc/modules");
622 	if (!fp)
623 		return 0;
624 	while ((line = xmalloc_fgetline(fp)) != NULL) {
625 		char *live;
626 		char *after_name;
627 
628 		// Examples from kernel 3.14.6:
629 		//pcspkr 12718 0 - Live 0xffffffffa017e000
630 		//snd_timer 28690 2 snd_seq,snd_pcm, Live 0xffffffffa025e000
631 		//i915 801405 2 - Live 0xffffffffa0096000
632 		after_name = is_prefixed_with(line, name);
633 		if (!after_name || *after_name != ' ') {
634 			free(line);
635 			continue;
636 		}
637 		live = strstr(line, " Live");
638 		free(line);
639 		if (!live) {
640 			/* State can be Unloading, Loading, or Live.
641 			 * modprobe must not return prematurely if we see "Loading":
642 			 * it can cause further programs to assume load completed,
643 			 * but it did not (yet)!
644 			 * Wait up to 5*20 ms for it to resolve.
645 			 */
646 			ret -= 2;
647 			if (ret == 0)
648 				break;  /* huh? report as "not loaded" */
649 			fclose(fp);
650 			usleep(20*1000);
651 			goto again;
652 		}
653 		ret = 1;
654 		break;
655 	}
656 	fclose(fp);
657 
658 	return ret & 1;
659 }
660 #else
661 #define already_loaded(name) 0
662 #endif
663 
rmmod(const char * filename)664 static int rmmod(const char *filename)
665 {
666 	int r;
667 	char modname[MODULE_NAME_LEN];
668 
669 	filename2modname(filename, modname);
670 	r = delete_module(modname, O_NONBLOCK | O_EXCL);
671 	dbg1_error_msg("delete_module('%s', O_NONBLOCK | O_EXCL):%d", modname, r);
672 	if (r != 0 && !(option_mask32 & OPT_q)) {
673 		bb_perror_msg("remove '%s'", modname);
674 	}
675 	return r;
676 }
677 
678 /*
679  * Given modules definition and module name (or alias, or symbol)
680  * load/remove the module respecting dependencies.
681  * NB: also called by depmod with bogus name "/",
682  * just in order to force modprobe.dep.bb creation.
683 */
684 #if !ENABLE_FEATURE_CMDLINE_MODULE_OPTIONS
685 #define process_module(a,b) process_module(a)
686 #define cmdline_options ""
687 #endif
process_module(char * name,const char * cmdline_options)688 static int process_module(char *name, const char *cmdline_options)
689 {
690 	char *s, *deps, *options;
691 	module_info **infovec;
692 	module_info *info;
693 	int infoidx;
694 	bool is_remove = (ENABLE_RMMOD && ONLY_APPLET)
695 		|| ((ENABLE_RMMOD || ENABLE_MODPROBE) && (option_mask32 & OPT_r));
696 	int exitcode = EXIT_SUCCESS;
697 
698 	dbg1_error_msg("process_module('%s','%s')", name, cmdline_options);
699 
700 	replace(name, '-', '_');
701 
702 	dbg1_error_msg("already_loaded:%d is_remove:%d", already_loaded(name), is_remove);
703 
704 	if (is_rmmod) {
705 		/* Does not remove dependencies, no need to scan, just remove.
706 		 * (compat note: this allows and strips .ko suffix)
707 		 */
708 		rmmod(name);
709 		return EXIT_SUCCESS;
710 	}
711 
712 	/*
713 	 * We used to have "is_remove != already_loaded(name)" check here, but
714 	 *  modprobe -r pci:v00008086d00007010sv00000000sd00000000bc01sc01i80
715 	 * won't unload modules (there are more than one)
716 	 * which have this alias.
717 	 */
718 	if (!is_remove && already_loaded(name)) {
719 		dbg1_error_msg("nothing to do for '%s'", name);
720 		return EXIT_SUCCESS;
721 	}
722 
723 	options = NULL;
724 	if (!is_remove) {
725 		char *opt_filename = xasprintf("/etc/modules/%s", name);
726 		options = xmalloc_open_read_close(opt_filename, NULL);
727 		if (options)
728 			replace(options, '\n', ' ');
729 #if ENABLE_FEATURE_CMDLINE_MODULE_OPTIONS
730 		if (cmdline_options) {
731 			/* NB: cmdline_options always have one leading ' '
732 			 * (see main()), we remove it here */
733 			char *op = xasprintf(options ? "%s %s" : "%s %s" + 3,
734 						cmdline_options + 1, options);
735 			free(options);
736 			options = op;
737 		}
738 #endif
739 		free(opt_filename);
740 		module_load_options = options;
741 		dbg1_error_msg("process_module('%s'): options:'%s'", name, options);
742 	}
743 
744 	if (!module_count) {
745 		/* Scan module directory. This is done only once.
746 		 * It will attempt module load, and will exit(EXIT_SUCCESS)
747 		 * on success.
748 		 */
749 		module_found_idx = -1;
750 		recursive_action(".",
751 			ACTION_RECURSE, /* flags */
752 			fileAction, /* file action */
753 			NULL, /* dir action */
754 			name /* user data */
755 		);
756 		dbg1_error_msg("dirscan complete");
757 		/* Module was not found, or load failed, or is_remove */
758 		if (module_found_idx >= 0) { /* module was found */
759 			infovec = xzalloc(2 * sizeof(infovec[0]));
760 			infovec[0] = &modinfo[module_found_idx];
761 		} else { /* search for alias, not a plain module name */
762 			infovec = find_alias(name);
763 		}
764 	} else {
765 		infovec = find_alias(name);
766 	}
767 
768 	if (!infovec) {
769 		/* both dirscan and find_alias found nothing */
770 		if (!is_remove && !is_depmod) { /* it wasn't rmmod or depmod */
771 			bb_error_msg("module '%s' not found", name);
772 //TODO: _and_die()? or should we continue (un)loading modules listed on cmdline?
773 			/* "modprobe non-existing-module; echo $?" must print 1 */
774 			exitcode = EXIT_FAILURE;
775 		}
776 		goto ret;
777 	}
778 
779 	/* There can be more than one module for the given alias. For example,
780 	 * "pci:v00008086d00007010sv00000000sd00000000bc01sc01i80" matches
781 	 * ata_piix because it has alias "pci:v00008086d00007010sv*sd*bc*sc*i*"
782 	 * and ata_generic, it has alias "pci:v*d*sv*sd*bc01sc01i*"
783 	 * Standard modprobe loads them both. We achieve it by returning
784 	 * a *list* of modinfo pointers from find_alias().
785 	 */
786 
787 	/* modprobe -r? unload module(s) */
788 	if (is_remove) {
789 		infoidx = 0;
790 		while ((info = infovec[infoidx++]) != NULL) {
791 			int r = rmmod(bb_get_last_path_component_nostrip(info->pathname));
792 			if (r != 0) {
793 				goto ret; /* error */
794 			}
795 		}
796 		/* modprobe -r: we do not stop here -
797 		 * continue to unload modules on which the module depends:
798 		 * "-r --remove: option causes modprobe to remove a module.
799 		 * If the modules it depends on are also unused, modprobe
800 		 * will try to remove them, too."
801 		 */
802 	}
803 
804 	infoidx = 0;
805 	while ((info = infovec[infoidx++]) != NULL) {
806 		/* Iterate thru dependencies, trying to (un)load them */
807 		deps = str_2_list(info->deps);
808 		for (s = deps; *s; s += strlen(s) + 1) {
809 			//if (strcmp(name, s) != 0) // N.B. do loops exist?
810 			dbg1_error_msg("recurse on dep '%s'", s);
811 			process_module(s, NULL);
812 			dbg1_error_msg("recurse on dep '%s' done", s);
813 		}
814 		free(deps);
815 
816 		if (is_remove)
817 			continue;
818 
819 		/* We are modprobe: load it */
820 		if (options && strstr(options, "blacklist")) {
821 			dbg1_error_msg("'%s': blacklisted", info->pathname);
822 			continue;
823 		}
824 		if (info->open_read_failed) {
825 			/* We already tried it, didn't work. Don't try load again */
826 			exitcode = EXIT_FAILURE;
827 			continue;
828 		}
829 		errno = 0;
830 		if (load_module(info->pathname, options) != 0) {
831 			if (EEXIST != errno) {
832 				bb_error_msg("'%s': %s",
833 					info->pathname,
834 					moderror(errno));
835 			} else {
836 				dbg1_error_msg("'%s': %s",
837 					info->pathname,
838 					moderror(errno));
839 			}
840 			exitcode = EXIT_FAILURE;
841 		}
842 	}
843  ret:
844 	free(infovec);
845 	free(options);
846 
847 	return exitcode;
848 }
849 #undef cmdline_options
850 
851 
852 /* For reference, module-init-tools v3.4 options:
853 
854 # insmod
855 Usage: insmod filename [args]
856 
857 # rmmod --help
858 Usage: rmmod [-fhswvV] modulename ...
859  -f (or --force) forces a module unload, and may crash your
860     machine. This requires the Forced Module Removal option
861     when the kernel was compiled.
862  -h (or --help) prints this help text
863  -s (or --syslog) says use syslog, not stderr
864  -v (or --verbose) enables more messages
865  -V (or --version) prints the version code
866  -w (or --wait) begins module removal even if it is used
867     and will stop new users from accessing the module (so it
868     should eventually fall to zero).
869 
870 # modprobe
871 Usage: modprobe [-v] [-V] [-C config-file] [-d <dirname> ] [-n] [-i] [-q]
872     [-b] [-o <modname>] [ --dump-modversions ] <modname> [parameters...]
873 modprobe -r [-n] [-i] [-v] <modulename> ...
874 modprobe -l -t <dirname> [ -a <modulename> ...]
875 
876 # depmod --help
877 depmod 3.13 -- part of module-init-tools
878 depmod -[aA] [-n -e -v -q -V -r -u -w -m]
879       [-b basedirectory] [forced_version]
880 depmod [-n -e -v -q -r -u -w] [-F kernelsyms] module1.ko module2.ko ...
881 If no arguments (except options) are given, "depmod -a" is assumed.
882 depmod will output a dependency list suitable for the modprobe utility.
883 Options:
884     -a, --all           Probe all modules
885     -A, --quick         Only does the work if there's a new module
886     -e, --errsyms       Report not supplied symbols
887     -m, --map           Create the legacy map files
888     -n, --show          Write the dependency file on stdout only
889     -P, --symbol-prefix Architecture symbol prefix
890     -V, --version       Print the release version
891     -v, --verbose       Enable verbose mode
892     -w, --warn          Warn on duplicates
893     -h, --help          Print this usage message
894 The following options are useful for people managing distributions:
895     -b basedirectory
896     --basedir basedirectory
897                         Use an image of a module tree
898     -F kernelsyms
899     --filesyms kernelsyms
900                         Use the file instead of the current kernel symbols
901     -E Module.symvers
902     --symvers Module.symvers
903                         Use Module.symvers file to check symbol versions
904 */
905 
906 //usage:#if ENABLE_MODPROBE_SMALL
907 
908 //usage:#define depmod_trivial_usage "[-n]"
909 //usage:#define depmod_full_usage "\n\n"
910 //usage:       "Generate modules.dep.bb"
911 //usage:     "\n"
912 //usage:     "\n	-n	Dry run: print file to stdout"
913 
914 //usage:#define insmod_trivial_usage
915 //usage:	"FILE" IF_FEATURE_CMDLINE_MODULE_OPTIONS(" [SYMBOL=VALUE]...")
916 //usage:#define insmod_full_usage "\n\n"
917 //usage:       "Load kernel module"
918 
919 //usage:#define rmmod_trivial_usage
920 //usage:       "MODULE..."
921 //usage:#define rmmod_full_usage "\n\n"
922 //usage:       "Unload kernel modules"
923 
924 //usage:#define modprobe_trivial_usage
925 //usage:	"[-rq] MODULE" IF_FEATURE_CMDLINE_MODULE_OPTIONS(" [SYMBOL=VALUE]...")
926 //usage:#define modprobe_full_usage "\n\n"
927 //usage:       "	-r	Remove MODULE"
928 //usage:     "\n	-q	Quiet"
929 
930 //usage:#endif
931 
932 int modprobe_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
modprobe_main(int argc UNUSED_PARAM,char ** argv)933 int modprobe_main(int argc UNUSED_PARAM, char **argv)
934 {
935 #if ENABLE_MODPROBE || ENABLE_INSMOD || ENABLE_RMMOD
936 	int exitcode;
937 #endif
938 	struct utsname uts;
939 	IF_FEATURE_CMDLINE_MODULE_OPTIONS(char *options = NULL;)
940 
941 	INIT_G();
942 
943 	/* Prevent ugly corner cases with no modules at all */
944 	modinfo = xzalloc(sizeof(modinfo[0]));
945 
946 	if ((MOD_APPLET_CNT == 2 && ENABLE_DEPMOD && ENABLE_MODPROBE)
947 	 || is_depmod || is_modprobe
948 	) {
949 		/* Goto modules directory */
950 		xchdir(CONFIG_DEFAULT_MODULES_DIR);
951 		uname(&uts); /* never fails */
952 	}
953 
954 	/* depmod? */
955 	if (is_depmod) {
956 		/* Supported:
957 		 * -n: print result to stdout
958 		 * -a: process all modules (default)
959 		 * optional VERSION parameter
960 		 * Ignored:
961 		 * -A: do work only if a module is newer than depfile
962 		 * -e: report any symbols which a module needs
963 		 *  which are not supplied by other modules or the kernel
964 		 * -F FILE: System.map (symbols for -e)
965 		 * -q, -r, -u: noop
966 		 * Not supported:
967 		 * -b BASEDIR: (TODO!) modules are in
968 		 *  $BASEDIR/lib/modules/$VERSION
969 		 * -m: create legacy "modules.*map" files (deprecated; in
970 		 *  kmod's depmod, prints a warning message and continues)
971 		 * -v: human readable deps to stdout
972 		 * -V: version (don't want to support it - people may depend
973 		 *  on it as an indicator of "standard" depmod)
974 		 * -h: help (well duh)
975 		 * module1.o module2.o parameters (just ignored for now)
976 		 */
977 		getopt32(argv, "na" "AeF:qru" /* "b:vV", NULL */, NULL);
978 		argv += optind;
979 		/* if (argv[0] && argv[1]) bb_show_usage(); */
980 		/* Goto $VERSION directory */
981 		xchdir(argv[0] ? argv[0] : uts.release);
982 		/* Force full module scan by asking to find a bogus module.
983 		 * This will generate modules.dep.bb as a side effect. */
984 		process_module((char*)"/", NULL);
985 		return !wrote_dep_bb_ok;
986 	}
987 
988 #if ENABLE_MODPROBE || ENABLE_INSMOD || ENABLE_RMMOD
989 	/* modprobe, insmod, rmmod require at least one argument */
990 	/* only -q (quiet) and -r (rmmod),
991 	 * the rest are accepted and ignored (compat) */
992 	getopt32(argv, "^" "qrfsvwb" "\0" "-1");
993 	argv += optind;
994 
995 	if (is_modprobe) {
996 		/* Goto $VERSION directory */
997 		xchdir(uts.release);
998 	}
999 
1000 	/* are we rmmod? -> simulate modprobe -r, but don't bother the flag if
1001 	 * there're no other applets here */
1002 	if (is_rmmod) {
1003 		if (!ONLY_APPLET)
1004 			option_mask32 |= OPT_r;
1005 	} else if (!ENABLE_MODPROBE || !(option_mask32 & OPT_r)) {
1006 # if ENABLE_FEATURE_CMDLINE_MODULE_OPTIONS
1007 	/* If not rmmod/-r, parse possible module options given on command line.
1008 	 * insmod/modprobe takes one module name, the rest are parameters. */
1009 		char **arg = argv;
1010 		while (*++arg) {
1011 			/* Enclose options in quotes */
1012 			char *s = options;
1013 			options = xasprintf("%s \"%s\"", s ? s : "", *arg);
1014 			free(s);
1015 			*arg = NULL;
1016 		}
1017 # else
1018 		argv[1] = NULL;
1019 # endif
1020 	}
1021 
1022 	if (is_insmod) {
1023 		size_t len;
1024 		void *map;
1025 
1026 		len = MAXINT(ssize_t);
1027 		map = xmalloc_open_zipped_read_close(*argv, &len);
1028 		if (!map)
1029 			bb_perror_msg_and_die("can't read '%s'", *argv);
1030 		if (init_module(map, len,
1031 			(IF_FEATURE_CMDLINE_MODULE_OPTIONS(options ? options : ) "")
1032 			) != 0
1033 		) {
1034 			bb_error_msg_and_die("can't insert '%s': %s",
1035 					*argv, moderror(errno));
1036 		}
1037 		return EXIT_SUCCESS;
1038 	}
1039 
1040 	/* Try to load modprobe.dep.bb */
1041 	if (!is_rmmod) {
1042 		load_dep_bb();
1043 	}
1044 
1045 	/* Load/remove modules.
1046 	 * Only rmmod/modprobe -r loops here, insmod/modprobe has only argv[0] */
1047 	exitcode = EXIT_SUCCESS;
1048 	do {
1049 		exitcode |= process_module(*argv, options);
1050 	} while (*++argv);
1051 
1052 	if (ENABLE_FEATURE_CLEAN_UP) {
1053 		IF_FEATURE_CMDLINE_MODULE_OPTIONS(free(options);)
1054 	}
1055 	return exitcode;
1056 #endif /* MODPROBE || INSMOD || RMMOD */
1057 }
1058 
1059 #endif /* MOD_APPLET_CNT > 0 */
1060