xref: /linux/security/tomoyo/util.c (revision ba33a49fcd42a94d405221cd0677388db1b69ed2) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * security/tomoyo/util.c
4  *
5  * Copyright (C) 2005-2011  NTT DATA CORPORATION
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/rculist.h>
10 
11 #include "common.h"
12 
13 /* Lock for protecting policy. */
14 DEFINE_MUTEX(tomoyo_policy_lock);
15 
16 /*
17  * Mapping table from "enum tomoyo_mac_index" to
18  * "enum tomoyo_mac_category_index".
19  */
20 const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = {
21 	/* CONFIG::file group */
22 	[TOMOYO_MAC_FILE_EXECUTE]    = TOMOYO_MAC_CATEGORY_FILE,
23 	[TOMOYO_MAC_FILE_OPEN]       = TOMOYO_MAC_CATEGORY_FILE,
24 	[TOMOYO_MAC_FILE_CREATE]     = TOMOYO_MAC_CATEGORY_FILE,
25 	[TOMOYO_MAC_FILE_UNLINK]     = TOMOYO_MAC_CATEGORY_FILE,
26 	[TOMOYO_MAC_FILE_GETATTR]    = TOMOYO_MAC_CATEGORY_FILE,
27 	[TOMOYO_MAC_FILE_MKDIR]      = TOMOYO_MAC_CATEGORY_FILE,
28 	[TOMOYO_MAC_FILE_RMDIR]      = TOMOYO_MAC_CATEGORY_FILE,
29 	[TOMOYO_MAC_FILE_MKFIFO]     = TOMOYO_MAC_CATEGORY_FILE,
30 	[TOMOYO_MAC_FILE_MKSOCK]     = TOMOYO_MAC_CATEGORY_FILE,
31 	[TOMOYO_MAC_FILE_TRUNCATE]   = TOMOYO_MAC_CATEGORY_FILE,
32 	[TOMOYO_MAC_FILE_SYMLINK]    = TOMOYO_MAC_CATEGORY_FILE,
33 	[TOMOYO_MAC_FILE_MKBLOCK]    = TOMOYO_MAC_CATEGORY_FILE,
34 	[TOMOYO_MAC_FILE_MKCHAR]     = TOMOYO_MAC_CATEGORY_FILE,
35 	[TOMOYO_MAC_FILE_LINK]       = TOMOYO_MAC_CATEGORY_FILE,
36 	[TOMOYO_MAC_FILE_RENAME]     = TOMOYO_MAC_CATEGORY_FILE,
37 	[TOMOYO_MAC_FILE_CHMOD]      = TOMOYO_MAC_CATEGORY_FILE,
38 	[TOMOYO_MAC_FILE_CHOWN]      = TOMOYO_MAC_CATEGORY_FILE,
39 	[TOMOYO_MAC_FILE_CHGRP]      = TOMOYO_MAC_CATEGORY_FILE,
40 	[TOMOYO_MAC_FILE_IOCTL]      = TOMOYO_MAC_CATEGORY_FILE,
41 	[TOMOYO_MAC_FILE_CHROOT]     = TOMOYO_MAC_CATEGORY_FILE,
42 	[TOMOYO_MAC_FILE_MOUNT]      = TOMOYO_MAC_CATEGORY_FILE,
43 	[TOMOYO_MAC_FILE_UMOUNT]     = TOMOYO_MAC_CATEGORY_FILE,
44 	[TOMOYO_MAC_FILE_PIVOT_ROOT] = TOMOYO_MAC_CATEGORY_FILE,
45 	/* CONFIG::network group */
46 	[TOMOYO_MAC_NETWORK_INET_STREAM_BIND]       =
47 	TOMOYO_MAC_CATEGORY_NETWORK,
48 	[TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN]     =
49 	TOMOYO_MAC_CATEGORY_NETWORK,
50 	[TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT]    =
51 	TOMOYO_MAC_CATEGORY_NETWORK,
52 	[TOMOYO_MAC_NETWORK_INET_DGRAM_BIND]        =
53 	TOMOYO_MAC_CATEGORY_NETWORK,
54 	[TOMOYO_MAC_NETWORK_INET_DGRAM_SEND]        =
55 	TOMOYO_MAC_CATEGORY_NETWORK,
56 	[TOMOYO_MAC_NETWORK_INET_RAW_BIND]          =
57 	TOMOYO_MAC_CATEGORY_NETWORK,
58 	[TOMOYO_MAC_NETWORK_INET_RAW_SEND]          =
59 	TOMOYO_MAC_CATEGORY_NETWORK,
60 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND]       =
61 	TOMOYO_MAC_CATEGORY_NETWORK,
62 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN]     =
63 	TOMOYO_MAC_CATEGORY_NETWORK,
64 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT]    =
65 	TOMOYO_MAC_CATEGORY_NETWORK,
66 	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND]        =
67 	TOMOYO_MAC_CATEGORY_NETWORK,
68 	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND]        =
69 	TOMOYO_MAC_CATEGORY_NETWORK,
70 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND]    =
71 	TOMOYO_MAC_CATEGORY_NETWORK,
72 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN]  =
73 	TOMOYO_MAC_CATEGORY_NETWORK,
74 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT] =
75 	TOMOYO_MAC_CATEGORY_NETWORK,
76 	/* CONFIG::misc group */
77 	[TOMOYO_MAC_ENVIRON]         = TOMOYO_MAC_CATEGORY_MISC,
78 };
79 
80 /**
81  * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
82  *
83  * @time64: Seconds since 1970/01/01 00:00:00.
84  * @stamp:  Pointer to "struct tomoyo_time".
85  *
86  * Returns nothing.
87  */
88 void tomoyo_convert_time(time64_t time64, struct tomoyo_time *stamp)
89 {
90 	struct tm tm;
91 
92 	time64_to_tm(time64, 0, &tm);
93 	stamp->sec = tm.tm_sec;
94 	stamp->min = tm.tm_min;
95 	stamp->hour = tm.tm_hour;
96 	stamp->day = tm.tm_mday;
97 	stamp->month = tm.tm_mon + 1;
98 	stamp->year = tm.tm_year + 1900;
99 }
100 
101 /**
102  * tomoyo_permstr - Find permission keywords.
103  *
104  * @string: String representation for permissions in foo/bar/buz format.
105  * @keyword: Keyword to find from @string/
106  *
107  * Returns true if @keyword was found in @string, false otherwise.
108  *
109  * This function assumes that strncmp(w1, w2, strlen(w1)) != 0 if w1 != w2.
110  */
111 bool tomoyo_permstr(const char *string, const char *keyword)
112 {
113 	const char *cp = strstr(string, keyword);
114 
115 	if (cp)
116 		return cp == string || *(cp - 1) == '/';
117 	return false;
118 }
119 
120 /**
121  * tomoyo_read_token - Read a word from a line.
122  *
123  * @param: Pointer to "struct tomoyo_acl_param".
124  *
125  * Returns a word on success, "" otherwise.
126  *
127  * To allow the caller to skip NULL check, this function returns "" rather than
128  * NULL if there is no more words to read.
129  */
130 char *tomoyo_read_token(struct tomoyo_acl_param *param)
131 {
132 	char *pos = param->data;
133 	char *del = strchr(pos, ' ');
134 
135 	if (del)
136 		*del++ = '\0';
137 	else
138 		del = pos + strlen(pos);
139 	param->data = del;
140 	return pos;
141 }
142 
143 static bool tomoyo_correct_path2(const char *filename, const size_t len);
144 
145 /**
146  * tomoyo_get_domainname - Read a domainname from a line.
147  *
148  * @param: Pointer to "struct tomoyo_acl_param".
149  *
150  * Returns a domainname on success, NULL otherwise.
151  */
152 const struct tomoyo_path_info *tomoyo_get_domainname
153 (struct tomoyo_acl_param *param)
154 {
155 	char *start = param->data;
156 	char *pos = start;
157 
158 	while (*pos) {
159 		if (*pos++ != ' ' ||
160 		    tomoyo_correct_path2(pos, strchrnul(pos, ' ') - pos))
161 			continue;
162 		*(pos - 1) = '\0';
163 		break;
164 	}
165 	param->data = pos;
166 	if (tomoyo_correct_domain(start))
167 		return tomoyo_get_name(start);
168 	return NULL;
169 }
170 
171 /**
172  * tomoyo_parse_ulong - Parse an "unsigned long" value.
173  *
174  * @result: Pointer to "unsigned long".
175  * @str:    Pointer to string to parse.
176  *
177  * Returns one of values in "enum tomoyo_value_type".
178  *
179  * The @src is updated to point the first character after the value
180  * on success.
181  */
182 u8 tomoyo_parse_ulong(unsigned long *result, char **str)
183 {
184 	const char *cp = *str;
185 	char *ep;
186 	int base = 10;
187 
188 	if (*cp == '0') {
189 		char c = *(cp + 1);
190 
191 		if (c == 'x' || c == 'X') {
192 			base = 16;
193 			cp += 2;
194 		} else if (c >= '0' && c <= '7') {
195 			base = 8;
196 			cp++;
197 		}
198 	}
199 	*result = simple_strtoul(cp, &ep, base);
200 	if (cp == ep)
201 		return TOMOYO_VALUE_TYPE_INVALID;
202 	*str = ep;
203 	switch (base) {
204 	case 16:
205 		return TOMOYO_VALUE_TYPE_HEXADECIMAL;
206 	case 8:
207 		return TOMOYO_VALUE_TYPE_OCTAL;
208 	default:
209 		return TOMOYO_VALUE_TYPE_DECIMAL;
210 	}
211 }
212 
213 /**
214  * tomoyo_print_ulong - Print an "unsigned long" value.
215  *
216  * @buffer:     Pointer to buffer.
217  * @buffer_len: Size of @buffer.
218  * @value:      An "unsigned long" value.
219  * @type:       Type of @value.
220  *
221  * Returns nothing.
222  */
223 void tomoyo_print_ulong(char *buffer, const int buffer_len,
224 			const unsigned long value, const u8 type)
225 {
226 	if (type == TOMOYO_VALUE_TYPE_DECIMAL)
227 		snprintf(buffer, buffer_len, "%lu", value);
228 	else if (type == TOMOYO_VALUE_TYPE_OCTAL)
229 		snprintf(buffer, buffer_len, "0%lo", value);
230 	else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL)
231 		snprintf(buffer, buffer_len, "0x%lX", value);
232 	else
233 		snprintf(buffer, buffer_len, "type(%u)", type);
234 }
235 
236 /**
237  * tomoyo_parse_name_union - Parse a tomoyo_name_union.
238  *
239  * @param: Pointer to "struct tomoyo_acl_param".
240  * @ptr:   Pointer to "struct tomoyo_name_union".
241  *
242  * Returns true on success, false otherwise.
243  */
244 bool tomoyo_parse_name_union(struct tomoyo_acl_param *param,
245 			     struct tomoyo_name_union *ptr)
246 {
247 	char *filename;
248 
249 	if (param->data[0] == '@') {
250 		param->data++;
251 		ptr->group = tomoyo_get_group(param, TOMOYO_PATH_GROUP);
252 		return ptr->group != NULL;
253 	}
254 	filename = tomoyo_read_token(param);
255 	if (!tomoyo_correct_word(filename))
256 		return false;
257 	ptr->filename = tomoyo_get_name(filename);
258 	return ptr->filename != NULL;
259 }
260 
261 /**
262  * tomoyo_parse_number_union - Parse a tomoyo_number_union.
263  *
264  * @param: Pointer to "struct tomoyo_acl_param".
265  * @ptr:   Pointer to "struct tomoyo_number_union".
266  *
267  * Returns true on success, false otherwise.
268  */
269 bool tomoyo_parse_number_union(struct tomoyo_acl_param *param,
270 			       struct tomoyo_number_union *ptr)
271 {
272 	char *data;
273 	u8 type;
274 	unsigned long v;
275 
276 	memset(ptr, 0, sizeof(*ptr));
277 	if (param->data[0] == '@') {
278 		param->data++;
279 		ptr->group = tomoyo_get_group(param, TOMOYO_NUMBER_GROUP);
280 		return ptr->group != NULL;
281 	}
282 	data = tomoyo_read_token(param);
283 	type = tomoyo_parse_ulong(&v, &data);
284 	if (type == TOMOYO_VALUE_TYPE_INVALID)
285 		return false;
286 	ptr->values[0] = v;
287 	ptr->value_type[0] = type;
288 	if (!*data) {
289 		ptr->values[1] = v;
290 		ptr->value_type[1] = type;
291 		return true;
292 	}
293 	if (*data++ != '-')
294 		return false;
295 	type = tomoyo_parse_ulong(&v, &data);
296 	if (type == TOMOYO_VALUE_TYPE_INVALID || *data || ptr->values[0] > v)
297 		return false;
298 	ptr->values[1] = v;
299 	ptr->value_type[1] = type;
300 	return true;
301 }
302 
303 /**
304  * tomoyo_byte_range - Check whether the string is a \ooo style octal value.
305  *
306  * @str: Pointer to the string.
307  *
308  * Returns true if @str is a \ooo style octal value, false otherwise.
309  *
310  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
311  * This function verifies that \ooo is in valid range.
312  */
313 static inline bool tomoyo_byte_range(const char *str)
314 {
315 	return *str >= '0' && *str++ <= '3' &&
316 		*str >= '0' && *str++ <= '7' &&
317 		*str >= '0' && *str <= '7';
318 }
319 
320 /**
321  * tomoyo_alphabet_char - Check whether the character is an alphabet.
322  *
323  * @c: The character to check.
324  *
325  * Returns true if @c is an alphabet character, false otherwise.
326  */
327 static inline bool tomoyo_alphabet_char(const char c)
328 {
329 	return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
330 }
331 
332 /**
333  * tomoyo_make_byte - Make byte value from three octal characters.
334  *
335  * @c1: The first character.
336  * @c2: The second character.
337  * @c3: The third character.
338  *
339  * Returns byte value.
340  */
341 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
342 {
343 	return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
344 }
345 
346 /**
347  * tomoyo_valid - Check whether the character is a valid char.
348  *
349  * @c: The character to check.
350  *
351  * Returns true if @c is a valid character, false otherwise.
352  */
353 static inline bool tomoyo_valid(const unsigned char c)
354 {
355 	return c > ' ' && c < 127;
356 }
357 
358 /**
359  * tomoyo_invalid - Check whether the character is an invalid char.
360  *
361  * @c: The character to check.
362  *
363  * Returns true if @c is an invalid character, false otherwise.
364  */
365 static inline bool tomoyo_invalid(const unsigned char c)
366 {
367 	return c && (c <= ' ' || c >= 127);
368 }
369 
370 /**
371  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
372  *
373  * @src:  Pointer to pointer to the string.
374  * @find: Pointer to the keyword.
375  *
376  * Returns true if @src starts with @find, false otherwise.
377  *
378  * The @src is updated to point the first character after the @find
379  * if @src starts with @find.
380  */
381 bool tomoyo_str_starts(char **src, const char *find)
382 {
383 	const int len = strlen(find);
384 	char *tmp = *src;
385 
386 	if (strncmp(tmp, find, len))
387 		return false;
388 	tmp += len;
389 	*src = tmp;
390 	return true;
391 }
392 
393 /**
394  * tomoyo_normalize_line - Format string.
395  *
396  * @buffer: The line to normalize.
397  *
398  * Leading and trailing whitespaces are removed.
399  * Multiple whitespaces are packed into single space.
400  *
401  * Returns nothing.
402  */
403 void tomoyo_normalize_line(unsigned char *buffer)
404 {
405 	unsigned char *sp = buffer;
406 	unsigned char *dp = buffer;
407 	bool first = true;
408 
409 	while (tomoyo_invalid(*sp))
410 		sp++;
411 	while (*sp) {
412 		if (!first)
413 			*dp++ = ' ';
414 		first = false;
415 		while (tomoyo_valid(*sp))
416 			*dp++ = *sp++;
417 		while (tomoyo_invalid(*sp))
418 			sp++;
419 	}
420 	*dp = '\0';
421 }
422 
423 /**
424  * tomoyo_correct_word2 - Validate a string.
425  *
426  * @string: The string to check. Maybe non-'\0'-terminated.
427  * @len:    Length of @string.
428  *
429  * Check whether the given string follows the naming rules.
430  * Returns true if @string follows the naming rules, false otherwise.
431  */
432 static bool tomoyo_correct_word2(const char *string, size_t len)
433 {
434 	u8 recursion = 20;
435 	const char *const start = string;
436 	bool in_repetition = false;
437 
438 	if (!len)
439 		goto out;
440 	while (len--) {
441 		unsigned char c = *string++;
442 
443 		if (c == '\\') {
444 			if (!len--)
445 				goto out;
446 			c = *string++;
447 			if (c >= '0' && c <= '3') {
448 				unsigned char d;
449 				unsigned char e;
450 
451 				if (!len-- || !len--)
452 					goto out;
453 				d = *string++;
454 				e = *string++;
455 				if (d < '0' || d > '7' || e < '0' || e > '7')
456 					goto out;
457 				c = tomoyo_make_byte(c, d, e);
458 				if (c <= ' ' || c >= 127)
459 					continue;
460 				goto out;
461 			}
462 			switch (c) {
463 			case '\\':  /* "\\" */
464 			case '+':   /* "\+" */
465 			case '?':   /* "\?" */
466 			case 'x':   /* "\x" */
467 			case 'a':   /* "\a" */
468 			case '-':   /* "\-" */
469 				continue;
470 			}
471 			if (!recursion--)
472 				goto out;
473 			switch (c) {
474 			case '*':   /* "\*" */
475 			case '@':   /* "\@" */
476 			case '$':   /* "\$" */
477 			case 'X':   /* "\X" */
478 			case 'A':   /* "\A" */
479 				continue;
480 			case '{':   /* "/\{" */
481 				if (string - 3 < start || *(string - 3) != '/')
482 					goto out;
483 				in_repetition = true;
484 				continue;
485 			case '}':   /* "\}/" */
486 				if (*string != '/')
487 					goto out;
488 				if (!in_repetition)
489 					goto out;
490 				in_repetition = false;
491 				continue;
492 			}
493 			goto out;
494 		} else if (in_repetition && c == '/') {
495 			goto out;
496 		} else if (c <= ' ' || c >= 127) {
497 			goto out;
498 		}
499 	}
500 	if (in_repetition)
501 		goto out;
502 	return true;
503  out:
504 	return false;
505 }
506 
507 /**
508  * tomoyo_correct_word - Validate a string.
509  *
510  * @string: The string to check.
511  *
512  * Check whether the given string follows the naming rules.
513  * Returns true if @string follows the naming rules, false otherwise.
514  */
515 bool tomoyo_correct_word(const char *string)
516 {
517 	return tomoyo_correct_word2(string, strlen(string));
518 }
519 
520 /**
521  * tomoyo_correct_path2 - Check whether the given pathname follows the naming rules.
522  *
523  * @filename: The pathname to check.
524  * @len:      Length of @filename.
525  *
526  * Returns true if @filename follows the naming rules, false otherwise.
527  */
528 static bool tomoyo_correct_path2(const char *filename, const size_t len)
529 {
530 	const char *cp1 = memchr(filename, '/', len);
531 	const char *cp2 = memchr(filename, '.', len);
532 
533 	return cp1 && (!cp2 || (cp1 < cp2)) && tomoyo_correct_word2(filename, len);
534 }
535 
536 /**
537  * tomoyo_correct_path - Validate a pathname.
538  *
539  * @filename: The pathname to check.
540  *
541  * Check whether the given pathname follows the naming rules.
542  * Returns true if @filename follows the naming rules, false otherwise.
543  */
544 bool tomoyo_correct_path(const char *filename)
545 {
546 	return tomoyo_correct_path2(filename, strlen(filename));
547 }
548 
549 /**
550  * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.
551  *
552  * @domainname: The domainname to check.
553  *
554  * Returns true if @domainname follows the naming rules, false otherwise.
555  */
556 bool tomoyo_correct_domain(const unsigned char *domainname)
557 {
558 	if (!domainname || !tomoyo_domain_def(domainname))
559 		return false;
560 	domainname = strchr(domainname, ' ');
561 	if (!domainname++)
562 		return true;
563 	while (1) {
564 		const unsigned char *cp = strchr(domainname, ' ');
565 
566 		if (!cp)
567 			break;
568 		if (!tomoyo_correct_path2(domainname, cp - domainname))
569 			return false;
570 		domainname = cp + 1;
571 	}
572 	return tomoyo_correct_path(domainname);
573 }
574 
575 /**
576  * tomoyo_domain_def - Check whether the given token can be a domainname.
577  *
578  * @buffer: The token to check.
579  *
580  * Returns true if @buffer possibly be a domainname, false otherwise.
581  */
582 bool tomoyo_domain_def(const unsigned char *buffer)
583 {
584 	const unsigned char *cp;
585 	int len;
586 
587 	if (*buffer != '<')
588 		return false;
589 	cp = strchr(buffer, ' ');
590 	if (!cp)
591 		len = strlen(buffer);
592 	else
593 		len = cp - buffer;
594 	if (buffer[len - 1] != '>' ||
595 	    !tomoyo_correct_word2(buffer + 1, len - 2))
596 		return false;
597 	return true;
598 }
599 
600 /**
601  * tomoyo_find_domain - Find a domain by the given name.
602  *
603  * @domainname: The domainname to find.
604  *
605  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
606  *
607  * Caller holds tomoyo_read_lock().
608  */
609 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
610 {
611 	struct tomoyo_domain_info *domain;
612 	struct tomoyo_path_info name;
613 
614 	name.name = domainname;
615 	tomoyo_fill_path_info(&name);
616 	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list,
617 				srcu_read_lock_held(&tomoyo_ss)) {
618 		if (!domain->is_deleted &&
619 		    !tomoyo_pathcmp(&name, domain->domainname))
620 			return domain;
621 	}
622 	return NULL;
623 }
624 
625 /**
626  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
627  *
628  * @filename: The string to evaluate.
629  *
630  * Returns the initial length without a pattern in @filename.
631  */
632 static int tomoyo_const_part_length(const char *filename)
633 {
634 	char c;
635 	int len = 0;
636 
637 	if (!filename)
638 		return 0;
639 	while ((c = *filename++) != '\0') {
640 		if (c != '\\') {
641 			len++;
642 			continue;
643 		}
644 		c = *filename++;
645 		switch (c) {
646 		case '\\':  /* "\\" */
647 			len += 2;
648 			continue;
649 		case '0':   /* "\ooo" */
650 		case '1':
651 		case '2':
652 		case '3':
653 			c = *filename++;
654 			if (c < '0' || c > '7')
655 				break;
656 			c = *filename++;
657 			if (c < '0' || c > '7')
658 				break;
659 			len += 4;
660 			continue;
661 		}
662 		break;
663 	}
664 	return len;
665 }
666 
667 /**
668  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
669  *
670  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
671  *
672  * The caller sets "struct tomoyo_path_info"->name.
673  */
674 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
675 {
676 	const char *name = ptr->name;
677 	const int len = strlen(name);
678 
679 	ptr->const_len = tomoyo_const_part_length(name);
680 	ptr->is_dir = len && (name[len - 1] == '/');
681 	ptr->is_patterned = (ptr->const_len < len);
682 	ptr->hash = full_name_hash(NULL, name, len);
683 }
684 
685 /**
686  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
687  *
688  * @filename:     The start of string to check.
689  * @filename_end: The end of string to check.
690  * @pattern:      The start of pattern to compare.
691  * @pattern_end:  The end of pattern to compare.
692  *
693  * Returns true if @filename matches @pattern, false otherwise.
694  */
695 static bool tomoyo_file_matches_pattern2(const char *filename,
696 					 const char *filename_end,
697 					 const char *pattern,
698 					 const char *pattern_end)
699 {
700 	while (filename < filename_end && pattern < pattern_end) {
701 		char c;
702 		int i;
703 		int j;
704 
705 		if (*pattern != '\\') {
706 			if (*filename++ != *pattern++)
707 				return false;
708 			continue;
709 		}
710 		c = *filename;
711 		pattern++;
712 		switch (*pattern) {
713 		case '?':
714 			if (c == '/') {
715 				return false;
716 			} else if (c == '\\') {
717 				if (filename[1] == '\\')
718 					filename++;
719 				else if (tomoyo_byte_range(filename + 1))
720 					filename += 3;
721 				else
722 					return false;
723 			}
724 			break;
725 		case '\\':
726 			if (c != '\\')
727 				return false;
728 			if (*++filename != '\\')
729 				return false;
730 			break;
731 		case '+':
732 			if (!isdigit(c))
733 				return false;
734 			break;
735 		case 'x':
736 			if (!isxdigit(c))
737 				return false;
738 			break;
739 		case 'a':
740 			if (!tomoyo_alphabet_char(c))
741 				return false;
742 			break;
743 		case '0':
744 		case '1':
745 		case '2':
746 		case '3':
747 			if (c == '\\' && tomoyo_byte_range(filename + 1)
748 			    && strncmp(filename + 1, pattern, 3) == 0) {
749 				filename += 3;
750 				pattern += 2;
751 				break;
752 			}
753 			return false; /* Not matched. */
754 		case '*':
755 		case '@':
756 			for (i = 0; i <= filename_end - filename; i++) {
757 				if (tomoyo_file_matches_pattern2(
758 						    filename + i, filename_end,
759 						    pattern + 1, pattern_end))
760 					return true;
761 				c = filename[i];
762 				if (c == '.' && *pattern == '@')
763 					break;
764 				if (c != '\\')
765 					continue;
766 				if (filename[i + 1] == '\\')
767 					i++;
768 				else if (tomoyo_byte_range(filename + i + 1))
769 					i += 3;
770 				else
771 					break; /* Bad pattern. */
772 			}
773 			return false; /* Not matched. */
774 		default:
775 			j = 0;
776 			c = *pattern;
777 			if (c == '$') {
778 				while (isdigit(filename[j]))
779 					j++;
780 			} else if (c == 'X') {
781 				while (isxdigit(filename[j]))
782 					j++;
783 			} else if (c == 'A') {
784 				while (tomoyo_alphabet_char(filename[j]))
785 					j++;
786 			}
787 			for (i = 1; i <= j; i++) {
788 				if (tomoyo_file_matches_pattern2(
789 						    filename + i, filename_end,
790 						    pattern + 1, pattern_end))
791 					return true;
792 			}
793 			return false; /* Not matched or bad pattern. */
794 		}
795 		filename++;
796 		pattern++;
797 	}
798 	while (*pattern == '\\' &&
799 	       (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
800 		pattern += 2;
801 	return filename == filename_end && pattern == pattern_end;
802 }
803 
804 /**
805  * tomoyo_file_matches_pattern - Pattern matching without '/' character.
806  *
807  * @filename:     The start of string to check.
808  * @filename_end: The end of string to check.
809  * @pattern:      The start of pattern to compare.
810  * @pattern_end:  The end of pattern to compare.
811  *
812  * Returns true if @filename matches @pattern, false otherwise.
813  */
814 static bool tomoyo_file_matches_pattern(const char *filename,
815 					const char *filename_end,
816 					const char *pattern,
817 					const char *pattern_end)
818 {
819 	const char *pattern_start = pattern;
820 	bool first = true;
821 	bool result;
822 
823 	while (pattern < pattern_end - 1) {
824 		/* Split at "\-" pattern. */
825 		if (*pattern++ != '\\' || *pattern++ != '-')
826 			continue;
827 		result = tomoyo_file_matches_pattern2(filename,
828 						      filename_end,
829 						      pattern_start,
830 						      pattern - 2);
831 		if (first)
832 			result = !result;
833 		if (result)
834 			return false;
835 		first = false;
836 		pattern_start = pattern;
837 	}
838 	result = tomoyo_file_matches_pattern2(filename, filename_end,
839 					      pattern_start, pattern_end);
840 	return first ? result : !result;
841 }
842 
843 /**
844  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
845  *
846  * @f: The start of string to check.
847  * @p: The start of pattern to compare.
848  *
849  * Returns true if @f matches @p, false otherwise.
850  */
851 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
852 {
853 	const char *f_delimiter;
854 	const char *p_delimiter;
855 
856 	while (*f && *p) {
857 		f_delimiter = strchr(f, '/');
858 		if (!f_delimiter)
859 			f_delimiter = f + strlen(f);
860 		p_delimiter = strchr(p, '/');
861 		if (!p_delimiter)
862 			p_delimiter = p + strlen(p);
863 		if (*p == '\\' && *(p + 1) == '{')
864 			goto recursive;
865 		if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
866 						 p_delimiter))
867 			return false;
868 		f = f_delimiter;
869 		if (*f)
870 			f++;
871 		p = p_delimiter;
872 		if (*p)
873 			p++;
874 	}
875 	/* Ignore trailing "\*" and "\@" in @pattern. */
876 	while (*p == '\\' &&
877 	       (*(p + 1) == '*' || *(p + 1) == '@'))
878 		p += 2;
879 	return !*f && !*p;
880  recursive:
881 	/*
882 	 * The "\{" pattern is permitted only after '/' character.
883 	 * This guarantees that below "*(p - 1)" is safe.
884 	 * Also, the "\}" pattern is permitted only before '/' character
885 	 * so that "\{" + "\}" pair will not break the "\-" operator.
886 	 */
887 	if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
888 	    *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
889 		return false; /* Bad pattern. */
890 	do {
891 		/* Compare current component with pattern. */
892 		if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
893 						 p_delimiter - 2))
894 			break;
895 		/* Proceed to next component. */
896 		f = f_delimiter;
897 		if (!*f)
898 			break;
899 		f++;
900 		/* Continue comparison. */
901 		if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
902 			return true;
903 		f_delimiter = strchr(f, '/');
904 	} while (f_delimiter);
905 	return false; /* Not matched. */
906 }
907 
908 /**
909  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
910  *
911  * @filename: The filename to check.
912  * @pattern:  The pattern to compare.
913  *
914  * Returns true if matches, false otherwise.
915  *
916  * The following patterns are available.
917  *   \\     \ itself.
918  *   \ooo   Octal representation of a byte.
919  *   \*     Zero or more repetitions of characters other than '/'.
920  *   \@     Zero or more repetitions of characters other than '/' or '.'.
921  *   \?     1 byte character other than '/'.
922  *   \$     One or more repetitions of decimal digits.
923  *   \+     1 decimal digit.
924  *   \X     One or more repetitions of hexadecimal digits.
925  *   \x     1 hexadecimal digit.
926  *   \A     One or more repetitions of alphabet characters.
927  *   \a     1 alphabet character.
928  *
929  *   \-     Subtraction operator.
930  *
931  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
932  *               /dir/dir/dir/ ).
933  */
934 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
935 				 const struct tomoyo_path_info *pattern)
936 {
937 	const char *f = filename->name;
938 	const char *p = pattern->name;
939 	const int len = pattern->const_len;
940 
941 	/* If @pattern doesn't contain pattern, I can use strcmp(). */
942 	if (!pattern->is_patterned)
943 		return !tomoyo_pathcmp(filename, pattern);
944 	/* Don't compare directory and non-directory. */
945 	if (filename->is_dir != pattern->is_dir)
946 		return false;
947 	/* Compare the initial length without patterns. */
948 	if (strncmp(f, p, len))
949 		return false;
950 	f += len;
951 	p += len;
952 	return tomoyo_path_matches_pattern2(f, p);
953 }
954 
955 /**
956  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
957  *
958  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
959  *
960  * This function uses kzalloc(), so the caller must call kfree()
961  * if this function didn't return NULL.
962  */
963 const char *tomoyo_get_exe(void)
964 {
965 	struct file *exe_file;
966 	const char *cp;
967 	struct mm_struct *mm = current->mm;
968 
969 	if (!mm)
970 		return NULL;
971 	exe_file = get_mm_exe_file(mm);
972 	if (!exe_file)
973 		return NULL;
974 
975 	cp = tomoyo_realpath_from_path(&exe_file->f_path);
976 	fput(exe_file);
977 	return cp;
978 }
979 
980 /**
981  * tomoyo_get_mode - Get MAC mode.
982  *
983  * @ns:      Pointer to "struct tomoyo_policy_namespace".
984  * @profile: Profile number.
985  * @index:   Index number of functionality.
986  *
987  * Returns mode.
988  */
989 int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
990 		    const u8 index)
991 {
992 	u8 mode;
993 	struct tomoyo_profile *p;
994 
995 	if (!tomoyo_policy_loaded)
996 		return TOMOYO_CONFIG_DISABLED;
997 	p = tomoyo_profile(ns, profile);
998 	mode = p->config[index];
999 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
1000 		mode = p->config[tomoyo_index2category[index]
1001 				 + TOMOYO_MAX_MAC_INDEX];
1002 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
1003 		mode = p->default_config;
1004 	return mode & 3;
1005 }
1006 
1007 /**
1008  * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
1009  *
1010  * @r:      Pointer to "struct tomoyo_request_info" to initialize.
1011  * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
1012  * @index:  Index number of functionality.
1013  *
1014  * Returns mode.
1015  */
1016 int tomoyo_init_request_info(struct tomoyo_request_info *r,
1017 			     struct tomoyo_domain_info *domain, const u8 index)
1018 {
1019 	u8 profile;
1020 
1021 	memset(r, 0, sizeof(*r));
1022 	if (!domain)
1023 		domain = tomoyo_domain();
1024 	r->domain = domain;
1025 	profile = domain->profile;
1026 	r->profile = profile;
1027 	r->type = index;
1028 	r->mode = tomoyo_get_mode(domain->ns, profile, index);
1029 	return r->mode;
1030 }
1031 
1032 /**
1033  * tomoyo_domain_quota_is_ok - Check for domain's quota.
1034  *
1035  * @r: Pointer to "struct tomoyo_request_info".
1036  *
1037  * Returns true if the domain is not exceeded quota, false otherwise.
1038  *
1039  * Caller holds tomoyo_read_lock().
1040  */
1041 bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
1042 {
1043 	unsigned int count = 0;
1044 	struct tomoyo_domain_info *domain = r->domain;
1045 	struct tomoyo_acl_info *ptr;
1046 
1047 	if (r->mode != TOMOYO_CONFIG_LEARNING)
1048 		return false;
1049 	if (!domain)
1050 		return true;
1051 	if (READ_ONCE(domain->flags[TOMOYO_DIF_QUOTA_WARNED]))
1052 		return false;
1053 	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list,
1054 				srcu_read_lock_held(&tomoyo_ss)) {
1055 		u16 perm;
1056 
1057 		if (ptr->is_deleted)
1058 			continue;
1059 		/*
1060 		 * Reading perm bitmap might race with tomoyo_merge_*() because
1061 		 * caller does not hold tomoyo_policy_lock mutex. But exceeding
1062 		 * max_learning_entry parameter by a few entries does not harm.
1063 		 */
1064 		switch (ptr->type) {
1065 		case TOMOYO_TYPE_PATH_ACL:
1066 			perm = data_race(container_of(ptr, struct tomoyo_path_acl, head)->perm);
1067 			break;
1068 		case TOMOYO_TYPE_PATH2_ACL:
1069 			perm = data_race(container_of(ptr, struct tomoyo_path2_acl, head)->perm);
1070 			break;
1071 		case TOMOYO_TYPE_PATH_NUMBER_ACL:
1072 			perm = data_race(container_of(ptr, struct tomoyo_path_number_acl, head)
1073 				  ->perm);
1074 			break;
1075 		case TOMOYO_TYPE_MKDEV_ACL:
1076 			perm = data_race(container_of(ptr, struct tomoyo_mkdev_acl, head)->perm);
1077 			break;
1078 		case TOMOYO_TYPE_INET_ACL:
1079 			perm = data_race(container_of(ptr, struct tomoyo_inet_acl, head)->perm);
1080 			break;
1081 		case TOMOYO_TYPE_UNIX_ACL:
1082 			perm = data_race(container_of(ptr, struct tomoyo_unix_acl, head)->perm);
1083 			break;
1084 		case TOMOYO_TYPE_MANUAL_TASK_ACL:
1085 			perm = 0;
1086 			break;
1087 		default:
1088 			perm = 1;
1089 		}
1090 		count += hweight16(perm);
1091 	}
1092 	if (count < tomoyo_profile(domain->ns, domain->profile)->
1093 	    pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
1094 		return true;
1095 	WRITE_ONCE(domain->flags[TOMOYO_DIF_QUOTA_WARNED], true);
1096 	/* r->granted = false; */
1097 	tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
1098 #ifndef CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING
1099 	pr_warn("WARNING: Domain '%s' has too many ACLs to hold. Stopped learning mode.\n",
1100 		domain->domainname->name);
1101 #endif
1102 	return false;
1103 }
1104