xref: /openbmc/linux/security/tomoyo/util.c (revision b96c0546) 
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 /* Has /sbin/init started? */
17 bool tomoyo_policy_loaded;
18 
19 /*
20  * Mapping table from "enum tomoyo_mac_index" to
21  * "enum tomoyo_mac_category_index".
22  */
23 const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = {
24 	/* CONFIG::file group */
25 	[TOMOYO_MAC_FILE_EXECUTE]    = TOMOYO_MAC_CATEGORY_FILE,
26 	[TOMOYO_MAC_FILE_OPEN]       = TOMOYO_MAC_CATEGORY_FILE,
27 	[TOMOYO_MAC_FILE_CREATE]     = TOMOYO_MAC_CATEGORY_FILE,
28 	[TOMOYO_MAC_FILE_UNLINK]     = TOMOYO_MAC_CATEGORY_FILE,
29 	[TOMOYO_MAC_FILE_GETATTR]    = TOMOYO_MAC_CATEGORY_FILE,
30 	[TOMOYO_MAC_FILE_MKDIR]      = TOMOYO_MAC_CATEGORY_FILE,
31 	[TOMOYO_MAC_FILE_RMDIR]      = TOMOYO_MAC_CATEGORY_FILE,
32 	[TOMOYO_MAC_FILE_MKFIFO]     = TOMOYO_MAC_CATEGORY_FILE,
33 	[TOMOYO_MAC_FILE_MKSOCK]     = TOMOYO_MAC_CATEGORY_FILE,
34 	[TOMOYO_MAC_FILE_TRUNCATE]   = TOMOYO_MAC_CATEGORY_FILE,
35 	[TOMOYO_MAC_FILE_SYMLINK]    = TOMOYO_MAC_CATEGORY_FILE,
36 	[TOMOYO_MAC_FILE_MKBLOCK]    = TOMOYO_MAC_CATEGORY_FILE,
37 	[TOMOYO_MAC_FILE_MKCHAR]     = TOMOYO_MAC_CATEGORY_FILE,
38 	[TOMOYO_MAC_FILE_LINK]       = TOMOYO_MAC_CATEGORY_FILE,
39 	[TOMOYO_MAC_FILE_RENAME]     = TOMOYO_MAC_CATEGORY_FILE,
40 	[TOMOYO_MAC_FILE_CHMOD]      = TOMOYO_MAC_CATEGORY_FILE,
41 	[TOMOYO_MAC_FILE_CHOWN]      = TOMOYO_MAC_CATEGORY_FILE,
42 	[TOMOYO_MAC_FILE_CHGRP]      = TOMOYO_MAC_CATEGORY_FILE,
43 	[TOMOYO_MAC_FILE_IOCTL]      = TOMOYO_MAC_CATEGORY_FILE,
44 	[TOMOYO_MAC_FILE_CHROOT]     = TOMOYO_MAC_CATEGORY_FILE,
45 	[TOMOYO_MAC_FILE_MOUNT]      = TOMOYO_MAC_CATEGORY_FILE,
46 	[TOMOYO_MAC_FILE_UMOUNT]     = TOMOYO_MAC_CATEGORY_FILE,
47 	[TOMOYO_MAC_FILE_PIVOT_ROOT] = TOMOYO_MAC_CATEGORY_FILE,
48 	/* CONFIG::network group */
49 	[TOMOYO_MAC_NETWORK_INET_STREAM_BIND]       =
50 	TOMOYO_MAC_CATEGORY_NETWORK,
51 	[TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN]     =
52 	TOMOYO_MAC_CATEGORY_NETWORK,
53 	[TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT]    =
54 	TOMOYO_MAC_CATEGORY_NETWORK,
55 	[TOMOYO_MAC_NETWORK_INET_DGRAM_BIND]        =
56 	TOMOYO_MAC_CATEGORY_NETWORK,
57 	[TOMOYO_MAC_NETWORK_INET_DGRAM_SEND]        =
58 	TOMOYO_MAC_CATEGORY_NETWORK,
59 	[TOMOYO_MAC_NETWORK_INET_RAW_BIND]          =
60 	TOMOYO_MAC_CATEGORY_NETWORK,
61 	[TOMOYO_MAC_NETWORK_INET_RAW_SEND]          =
62 	TOMOYO_MAC_CATEGORY_NETWORK,
63 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND]       =
64 	TOMOYO_MAC_CATEGORY_NETWORK,
65 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN]     =
66 	TOMOYO_MAC_CATEGORY_NETWORK,
67 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT]    =
68 	TOMOYO_MAC_CATEGORY_NETWORK,
69 	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND]        =
70 	TOMOYO_MAC_CATEGORY_NETWORK,
71 	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND]        =
72 	TOMOYO_MAC_CATEGORY_NETWORK,
73 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND]    =
74 	TOMOYO_MAC_CATEGORY_NETWORK,
75 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN]  =
76 	TOMOYO_MAC_CATEGORY_NETWORK,
77 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT] =
78 	TOMOYO_MAC_CATEGORY_NETWORK,
79 	/* CONFIG::misc group */
80 	[TOMOYO_MAC_ENVIRON]         = TOMOYO_MAC_CATEGORY_MISC,
81 };
82 
83 /**
84  * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
85  *
86  * @time:  Seconds since 1970/01/01 00:00:00.
87  * @stamp: Pointer to "struct tomoyo_time".
88  *
89  * Returns nothing.
90  */
91 void tomoyo_convert_time(time64_t time64, struct tomoyo_time *stamp)
92 {
93 	struct tm tm;
94 
95 	time64_to_tm(time64, 0, &tm);
96 	stamp->sec = tm.tm_sec;
97 	stamp->min = tm.tm_min;
98 	stamp->hour = tm.tm_hour;
99 	stamp->day = tm.tm_mday;
100 	stamp->month = tm.tm_mon + 1;
101 	stamp->year = tm.tm_year + 1900;
102 }
103 
104 /**
105  * tomoyo_permstr - Find permission keywords.
106  *
107  * @string: String representation for permissions in foo/bar/buz format.
108  * @keyword: Keyword to find from @string/
109  *
110  * Returns true if @keyword was found in @string, false otherwise.
111  *
112  * This function assumes that strncmp(w1, w2, strlen(w1)) != 0 if w1 != w2.
113  */
114 bool tomoyo_permstr(const char *string, const char *keyword)
115 {
116 	const char *cp = strstr(string, keyword);
117 
118 	if (cp)
119 		return cp == string || *(cp - 1) == '/';
120 	return false;
121 }
122 
123 /**
124  * tomoyo_read_token - Read a word from a line.
125  *
126  * @param: Pointer to "struct tomoyo_acl_param".
127  *
128  * Returns a word on success, "" otherwise.
129  *
130  * To allow the caller to skip NULL check, this function returns "" rather than
131  * NULL if there is no more words to read.
132  */
133 char *tomoyo_read_token(struct tomoyo_acl_param *param)
134 {
135 	char *pos = param->data;
136 	char *del = strchr(pos, ' ');
137 
138 	if (del)
139 		*del++ = '\0';
140 	else
141 		del = pos + strlen(pos);
142 	param->data = del;
143 	return pos;
144 }
145 
146 static bool tomoyo_correct_path2(const char *filename, const size_t len);
147 
148 /**
149  * tomoyo_get_domainname - Read a domainname from a line.
150  *
151  * @param: Pointer to "struct tomoyo_acl_param".
152  *
153  * Returns a domainname on success, NULL otherwise.
154  */
155 const struct tomoyo_path_info *tomoyo_get_domainname
156 (struct tomoyo_acl_param *param)
157 {
158 	char *start = param->data;
159 	char *pos = start;
160 
161 	while (*pos) {
162 		if (*pos++ != ' ' ||
163 		    tomoyo_correct_path2(pos, strchrnul(pos, ' ') - pos))
164 			continue;
165 		*(pos - 1) = '\0';
166 		break;
167 	}
168 	param->data = pos;
169 	if (tomoyo_correct_domain(start))
170 		return tomoyo_get_name(start);
171 	return NULL;
172 }
173 
174 /**
175  * tomoyo_parse_ulong - Parse an "unsigned long" value.
176  *
177  * @result: Pointer to "unsigned long".
178  * @str:    Pointer to string to parse.
179  *
180  * Returns one of values in "enum tomoyo_value_type".
181  *
182  * The @src is updated to point the first character after the value
183  * on success.
184  */
185 u8 tomoyo_parse_ulong(unsigned long *result, char **str)
186 {
187 	const char *cp = *str;
188 	char *ep;
189 	int base = 10;
190 
191 	if (*cp == '0') {
192 		char c = *(cp + 1);
193 
194 		if (c == 'x' || c == 'X') {
195 			base = 16;
196 			cp += 2;
197 		} else if (c >= '0' && c <= '7') {
198 			base = 8;
199 			cp++;
200 		}
201 	}
202 	*result = simple_strtoul(cp, &ep, base);
203 	if (cp == ep)
204 		return TOMOYO_VALUE_TYPE_INVALID;
205 	*str = ep;
206 	switch (base) {
207 	case 16:
208 		return TOMOYO_VALUE_TYPE_HEXADECIMAL;
209 	case 8:
210 		return TOMOYO_VALUE_TYPE_OCTAL;
211 	default:
212 		return TOMOYO_VALUE_TYPE_DECIMAL;
213 	}
214 }
215 
216 /**
217  * tomoyo_print_ulong - Print an "unsigned long" value.
218  *
219  * @buffer:     Pointer to buffer.
220  * @buffer_len: Size of @buffer.
221  * @value:      An "unsigned long" value.
222  * @type:       Type of @value.
223  *
224  * Returns nothing.
225  */
226 void tomoyo_print_ulong(char *buffer, const int buffer_len,
227 			const unsigned long value, const u8 type)
228 {
229 	if (type == TOMOYO_VALUE_TYPE_DECIMAL)
230 		snprintf(buffer, buffer_len, "%lu", value);
231 	else if (type == TOMOYO_VALUE_TYPE_OCTAL)
232 		snprintf(buffer, buffer_len, "0%lo", value);
233 	else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL)
234 		snprintf(buffer, buffer_len, "0x%lX", value);
235 	else
236 		snprintf(buffer, buffer_len, "type(%u)", type);
237 }
238 
239 /**
240  * tomoyo_parse_name_union - Parse a tomoyo_name_union.
241  *
242  * @param: Pointer to "struct tomoyo_acl_param".
243  * @ptr:   Pointer to "struct tomoyo_name_union".
244  *
245  * Returns true on success, false otherwise.
246  */
247 bool tomoyo_parse_name_union(struct tomoyo_acl_param *param,
248 			     struct tomoyo_name_union *ptr)
249 {
250 	char *filename;
251 
252 	if (param->data[0] == '@') {
253 		param->data++;
254 		ptr->group = tomoyo_get_group(param, TOMOYO_PATH_GROUP);
255 		return ptr->group != NULL;
256 	}
257 	filename = tomoyo_read_token(param);
258 	if (!tomoyo_correct_word(filename))
259 		return false;
260 	ptr->filename = tomoyo_get_name(filename);
261 	return ptr->filename != NULL;
262 }
263 
264 /**
265  * tomoyo_parse_number_union - Parse a tomoyo_number_union.
266  *
267  * @param: Pointer to "struct tomoyo_acl_param".
268  * @ptr:   Pointer to "struct tomoyo_number_union".
269  *
270  * Returns true on success, false otherwise.
271  */
272 bool tomoyo_parse_number_union(struct tomoyo_acl_param *param,
273 			       struct tomoyo_number_union *ptr)
274 {
275 	char *data;
276 	u8 type;
277 	unsigned long v;
278 
279 	memset(ptr, 0, sizeof(*ptr));
280 	if (param->data[0] == '@') {
281 		param->data++;
282 		ptr->group = tomoyo_get_group(param, TOMOYO_NUMBER_GROUP);
283 		return ptr->group != NULL;
284 	}
285 	data = tomoyo_read_token(param);
286 	type = tomoyo_parse_ulong(&v, &data);
287 	if (type == TOMOYO_VALUE_TYPE_INVALID)
288 		return false;
289 	ptr->values[0] = v;
290 	ptr->value_type[0] = type;
291 	if (!*data) {
292 		ptr->values[1] = v;
293 		ptr->value_type[1] = type;
294 		return true;
295 	}
296 	if (*data++ != '-')
297 		return false;
298 	type = tomoyo_parse_ulong(&v, &data);
299 	if (type == TOMOYO_VALUE_TYPE_INVALID || *data || ptr->values[0] > v)
300 		return false;
301 	ptr->values[1] = v;
302 	ptr->value_type[1] = type;
303 	return true;
304 }
305 
306 /**
307  * tomoyo_byte_range - Check whether the string is a \ooo style octal value.
308  *
309  * @str: Pointer to the string.
310  *
311  * Returns true if @str is a \ooo style octal value, false otherwise.
312  *
313  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
314  * This function verifies that \ooo is in valid range.
315  */
316 static inline bool tomoyo_byte_range(const char *str)
317 {
318 	return *str >= '0' && *str++ <= '3' &&
319 		*str >= '0' && *str++ <= '7' &&
320 		*str >= '0' && *str <= '7';
321 }
322 
323 /**
324  * tomoyo_alphabet_char - Check whether the character is an alphabet.
325  *
326  * @c: The character to check.
327  *
328  * Returns true if @c is an alphabet character, false otherwise.
329  */
330 static inline bool tomoyo_alphabet_char(const char c)
331 {
332 	return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
333 }
334 
335 /**
336  * tomoyo_make_byte - Make byte value from three octal characters.
337  *
338  * @c1: The first character.
339  * @c2: The second character.
340  * @c3: The third character.
341  *
342  * Returns byte value.
343  */
344 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
345 {
346 	return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
347 }
348 
349 /**
350  * tomoyo_valid - Check whether the character is a valid char.
351  *
352  * @c: The character to check.
353  *
354  * Returns true if @c is a valid character, false otherwise.
355  */
356 static inline bool tomoyo_valid(const unsigned char c)
357 {
358 	return c > ' ' && c < 127;
359 }
360 
361 /**
362  * tomoyo_invalid - Check whether the character is an invalid char.
363  *
364  * @c: The character to check.
365  *
366  * Returns true if @c is an invalid character, false otherwise.
367  */
368 static inline bool tomoyo_invalid(const unsigned char c)
369 {
370 	return c && (c <= ' ' || c >= 127);
371 }
372 
373 /**
374  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
375  *
376  * @src:  Pointer to pointer to the string.
377  * @find: Pointer to the keyword.
378  *
379  * Returns true if @src starts with @find, false otherwise.
380  *
381  * The @src is updated to point the first character after the @find
382  * if @src starts with @find.
383  */
384 bool tomoyo_str_starts(char **src, const char *find)
385 {
386 	const int len = strlen(find);
387 	char *tmp = *src;
388 
389 	if (strncmp(tmp, find, len))
390 		return false;
391 	tmp += len;
392 	*src = tmp;
393 	return true;
394 }
395 
396 /**
397  * tomoyo_normalize_line - Format string.
398  *
399  * @buffer: The line to normalize.
400  *
401  * Leading and trailing whitespaces are removed.
402  * Multiple whitespaces are packed into single space.
403  *
404  * Returns nothing.
405  */
406 void tomoyo_normalize_line(unsigned char *buffer)
407 {
408 	unsigned char *sp = buffer;
409 	unsigned char *dp = buffer;
410 	bool first = true;
411 
412 	while (tomoyo_invalid(*sp))
413 		sp++;
414 	while (*sp) {
415 		if (!first)
416 			*dp++ = ' ';
417 		first = false;
418 		while (tomoyo_valid(*sp))
419 			*dp++ = *sp++;
420 		while (tomoyo_invalid(*sp))
421 			sp++;
422 	}
423 	*dp = '\0';
424 }
425 
426 /**
427  * tomoyo_correct_word2 - Validate a string.
428  *
429  * @string: The string to check. Maybe non-'\0'-terminated.
430  * @len:    Length of @string.
431  *
432  * Check whether the given string follows the naming rules.
433  * Returns true if @string follows the naming rules, false otherwise.
434  */
435 static bool tomoyo_correct_word2(const char *string, size_t len)
436 {
437 	const char *const start = string;
438 	bool in_repetition = false;
439 	unsigned char c;
440 	unsigned char d;
441 	unsigned char e;
442 
443 	if (!len)
444 		goto out;
445 	while (len--) {
446 		c = *string++;
447 		if (c == '\\') {
448 			if (!len--)
449 				goto out;
450 			c = *string++;
451 			switch (c) {
452 			case '\\':  /* "\\" */
453 				continue;
454 			case '$':   /* "\$" */
455 			case '+':   /* "\+" */
456 			case '?':   /* "\?" */
457 			case '*':   /* "\*" */
458 			case '@':   /* "\@" */
459 			case 'x':   /* "\x" */
460 			case 'X':   /* "\X" */
461 			case 'a':   /* "\a" */
462 			case 'A':   /* "\A" */
463 			case '-':   /* "\-" */
464 				continue;
465 			case '{':   /* "/\{" */
466 				if (string - 3 < start || *(string - 3) != '/')
467 					break;
468 				in_repetition = true;
469 				continue;
470 			case '}':   /* "\}/" */
471 				if (*string != '/')
472 					break;
473 				if (!in_repetition)
474 					break;
475 				in_repetition = false;
476 				continue;
477 			case '0':   /* "\ooo" */
478 			case '1':
479 			case '2':
480 			case '3':
481 				if (!len-- || !len--)
482 					break;
483 				d = *string++;
484 				e = *string++;
485 				if (d < '0' || d > '7' || e < '0' || e > '7')
486 					break;
487 				c = tomoyo_make_byte(c, d, e);
488 				if (c <= ' ' || c >= 127)
489 					continue;
490 			}
491 			goto out;
492 		} else if (in_repetition && c == '/') {
493 			goto out;
494 		} else if (c <= ' ' || c >= 127) {
495 			goto out;
496 		}
497 	}
498 	if (in_repetition)
499 		goto out;
500 	return true;
501  out:
502 	return false;
503 }
504 
505 /**
506  * tomoyo_correct_word - Validate a string.
507  *
508  * @string: The string to check.
509  *
510  * Check whether the given string follows the naming rules.
511  * Returns true if @string follows the naming rules, false otherwise.
512  */
513 bool tomoyo_correct_word(const char *string)
514 {
515 	return tomoyo_correct_word2(string, strlen(string));
516 }
517 
518 /**
519  * tomoyo_correct_path2 - Check whether the given pathname follows the naming rules.
520  *
521  * @filename: The pathname to check.
522  * @len:      Length of @filename.
523  *
524  * Returns true if @filename follows the naming rules, false otherwise.
525  */
526 static bool tomoyo_correct_path2(const char *filename, const size_t len)
527 {
528 	const char *cp1 = memchr(filename, '/', len);
529 	const char *cp2 = memchr(filename, '.', len);
530 
531 	return cp1 && (!cp2 || (cp1 < cp2)) && tomoyo_correct_word2(filename, len);
532 }
533 
534 /**
535  * tomoyo_correct_path - Validate a pathname.
536  *
537  * @filename: The pathname to check.
538  *
539  * Check whether the given pathname follows the naming rules.
540  * Returns true if @filename follows the naming rules, false otherwise.
541  */
542 bool tomoyo_correct_path(const char *filename)
543 {
544 	return tomoyo_correct_path2(filename, strlen(filename));
545 }
546 
547 /**
548  * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.
549  *
550  * @domainname: The domainname to check.
551  *
552  * Returns true if @domainname follows the naming rules, false otherwise.
553  */
554 bool tomoyo_correct_domain(const unsigned char *domainname)
555 {
556 	if (!domainname || !tomoyo_domain_def(domainname))
557 		return false;
558 	domainname = strchr(domainname, ' ');
559 	if (!domainname++)
560 		return true;
561 	while (1) {
562 		const unsigned char *cp = strchr(domainname, ' ');
563 
564 		if (!cp)
565 			break;
566 		if (!tomoyo_correct_path2(domainname, cp - domainname))
567 			return false;
568 		domainname = cp + 1;
569 	}
570 	return tomoyo_correct_path(domainname);
571 }
572 
573 /**
574  * tomoyo_domain_def - Check whether the given token can be a domainname.
575  *
576  * @buffer: The token to check.
577  *
578  * Returns true if @buffer possibly be a domainname, false otherwise.
579  */
580 bool tomoyo_domain_def(const unsigned char *buffer)
581 {
582 	const unsigned char *cp;
583 	int len;
584 
585 	if (*buffer != '<')
586 		return false;
587 	cp = strchr(buffer, ' ');
588 	if (!cp)
589 		len = strlen(buffer);
590 	else
591 		len = cp - buffer;
592 	if (buffer[len - 1] != '>' ||
593 	    !tomoyo_correct_word2(buffer + 1, len - 2))
594 		return false;
595 	return true;
596 }
597 
598 /**
599  * tomoyo_find_domain - Find a domain by the given name.
600  *
601  * @domainname: The domainname to find.
602  *
603  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
604  *
605  * Caller holds tomoyo_read_lock().
606  */
607 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
608 {
609 	struct tomoyo_domain_info *domain;
610 	struct tomoyo_path_info name;
611 
612 	name.name = domainname;
613 	tomoyo_fill_path_info(&name);
614 	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list,
615 				srcu_read_lock_held(&tomoyo_ss)) {
616 		if (!domain->is_deleted &&
617 		    !tomoyo_pathcmp(&name, domain->domainname))
618 			return domain;
619 	}
620 	return NULL;
621 }
622 
623 /**
624  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
625  *
626  * @filename: The string to evaluate.
627  *
628  * Returns the initial length without a pattern in @filename.
629  */
630 static int tomoyo_const_part_length(const char *filename)
631 {
632 	char c;
633 	int len = 0;
634 
635 	if (!filename)
636 		return 0;
637 	while ((c = *filename++) != '\0') {
638 		if (c != '\\') {
639 			len++;
640 			continue;
641 		}
642 		c = *filename++;
643 		switch (c) {
644 		case '\\':  /* "\\" */
645 			len += 2;
646 			continue;
647 		case '0':   /* "\ooo" */
648 		case '1':
649 		case '2':
650 		case '3':
651 			c = *filename++;
652 			if (c < '0' || c > '7')
653 				break;
654 			c = *filename++;
655 			if (c < '0' || c > '7')
656 				break;
657 			len += 4;
658 			continue;
659 		}
660 		break;
661 	}
662 	return len;
663 }
664 
665 /**
666  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
667  *
668  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
669  *
670  * The caller sets "struct tomoyo_path_info"->name.
671  */
672 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
673 {
674 	const char *name = ptr->name;
675 	const int len = strlen(name);
676 
677 	ptr->const_len = tomoyo_const_part_length(name);
678 	ptr->is_dir = len && (name[len - 1] == '/');
679 	ptr->is_patterned = (ptr->const_len < len);
680 	ptr->hash = full_name_hash(NULL, name, len);
681 }
682 
683 /**
684  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
685  *
686  * @filename:     The start of string to check.
687  * @filename_end: The end of string to check.
688  * @pattern:      The start of pattern to compare.
689  * @pattern_end:  The end of pattern to compare.
690  *
691  * Returns true if @filename matches @pattern, false otherwise.
692  */
693 static bool tomoyo_file_matches_pattern2(const char *filename,
694 					 const char *filename_end,
695 					 const char *pattern,
696 					 const char *pattern_end)
697 {
698 	while (filename < filename_end && pattern < pattern_end) {
699 		char c;
700 		int i;
701 		int j;
702 
703 		if (*pattern != '\\') {
704 			if (*filename++ != *pattern++)
705 				return false;
706 			continue;
707 		}
708 		c = *filename;
709 		pattern++;
710 		switch (*pattern) {
711 		case '?':
712 			if (c == '/') {
713 				return false;
714 			} else if (c == '\\') {
715 				if (filename[1] == '\\')
716 					filename++;
717 				else if (tomoyo_byte_range(filename + 1))
718 					filename += 3;
719 				else
720 					return false;
721 			}
722 			break;
723 		case '\\':
724 			if (c != '\\')
725 				return false;
726 			if (*++filename != '\\')
727 				return false;
728 			break;
729 		case '+':
730 			if (!isdigit(c))
731 				return false;
732 			break;
733 		case 'x':
734 			if (!isxdigit(c))
735 				return false;
736 			break;
737 		case 'a':
738 			if (!tomoyo_alphabet_char(c))
739 				return false;
740 			break;
741 		case '0':
742 		case '1':
743 		case '2':
744 		case '3':
745 			if (c == '\\' && tomoyo_byte_range(filename + 1)
746 			    && strncmp(filename + 1, pattern, 3) == 0) {
747 				filename += 3;
748 				pattern += 2;
749 				break;
750 			}
751 			return false; /* Not matched. */
752 		case '*':
753 		case '@':
754 			for (i = 0; i <= filename_end - filename; i++) {
755 				if (tomoyo_file_matches_pattern2(
756 						    filename + i, filename_end,
757 						    pattern + 1, pattern_end))
758 					return true;
759 				c = filename[i];
760 				if (c == '.' && *pattern == '@')
761 					break;
762 				if (c != '\\')
763 					continue;
764 				if (filename[i + 1] == '\\')
765 					i++;
766 				else if (tomoyo_byte_range(filename + i + 1))
767 					i += 3;
768 				else
769 					break; /* Bad pattern. */
770 			}
771 			return false; /* Not matched. */
772 		default:
773 			j = 0;
774 			c = *pattern;
775 			if (c == '$') {
776 				while (isdigit(filename[j]))
777 					j++;
778 			} else if (c == 'X') {
779 				while (isxdigit(filename[j]))
780 					j++;
781 			} else if (c == 'A') {
782 				while (tomoyo_alphabet_char(filename[j]))
783 					j++;
784 			}
785 			for (i = 1; i <= j; i++) {
786 				if (tomoyo_file_matches_pattern2(
787 						    filename + i, filename_end,
788 						    pattern + 1, pattern_end))
789 					return true;
790 			}
791 			return false; /* Not matched or bad pattern. */
792 		}
793 		filename++;
794 		pattern++;
795 	}
796 	while (*pattern == '\\' &&
797 	       (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
798 		pattern += 2;
799 	return filename == filename_end && pattern == pattern_end;
800 }
801 
802 /**
803  * tomoyo_file_matches_pattern - Pattern matching without '/' character.
804  *
805  * @filename:     The start of string to check.
806  * @filename_end: The end of string to check.
807  * @pattern:      The start of pattern to compare.
808  * @pattern_end:  The end of pattern to compare.
809  *
810  * Returns true if @filename matches @pattern, false otherwise.
811  */
812 static bool tomoyo_file_matches_pattern(const char *filename,
813 					const char *filename_end,
814 					const char *pattern,
815 					const char *pattern_end)
816 {
817 	const char *pattern_start = pattern;
818 	bool first = true;
819 	bool result;
820 
821 	while (pattern < pattern_end - 1) {
822 		/* Split at "\-" pattern. */
823 		if (*pattern++ != '\\' || *pattern++ != '-')
824 			continue;
825 		result = tomoyo_file_matches_pattern2(filename,
826 						      filename_end,
827 						      pattern_start,
828 						      pattern - 2);
829 		if (first)
830 			result = !result;
831 		if (result)
832 			return false;
833 		first = false;
834 		pattern_start = pattern;
835 	}
836 	result = tomoyo_file_matches_pattern2(filename, filename_end,
837 					      pattern_start, pattern_end);
838 	return first ? result : !result;
839 }
840 
841 /**
842  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
843  *
844  * @f: The start of string to check.
845  * @p: The start of pattern to compare.
846  *
847  * Returns true if @f matches @p, false otherwise.
848  */
849 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
850 {
851 	const char *f_delimiter;
852 	const char *p_delimiter;
853 
854 	while (*f && *p) {
855 		f_delimiter = strchr(f, '/');
856 		if (!f_delimiter)
857 			f_delimiter = f + strlen(f);
858 		p_delimiter = strchr(p, '/');
859 		if (!p_delimiter)
860 			p_delimiter = p + strlen(p);
861 		if (*p == '\\' && *(p + 1) == '{')
862 			goto recursive;
863 		if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
864 						 p_delimiter))
865 			return false;
866 		f = f_delimiter;
867 		if (*f)
868 			f++;
869 		p = p_delimiter;
870 		if (*p)
871 			p++;
872 	}
873 	/* Ignore trailing "\*" and "\@" in @pattern. */
874 	while (*p == '\\' &&
875 	       (*(p + 1) == '*' || *(p + 1) == '@'))
876 		p += 2;
877 	return !*f && !*p;
878  recursive:
879 	/*
880 	 * The "\{" pattern is permitted only after '/' character.
881 	 * This guarantees that below "*(p - 1)" is safe.
882 	 * Also, the "\}" pattern is permitted only before '/' character
883 	 * so that "\{" + "\}" pair will not break the "\-" operator.
884 	 */
885 	if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
886 	    *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
887 		return false; /* Bad pattern. */
888 	do {
889 		/* Compare current component with pattern. */
890 		if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
891 						 p_delimiter - 2))
892 			break;
893 		/* Proceed to next component. */
894 		f = f_delimiter;
895 		if (!*f)
896 			break;
897 		f++;
898 		/* Continue comparison. */
899 		if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
900 			return true;
901 		f_delimiter = strchr(f, '/');
902 	} while (f_delimiter);
903 	return false; /* Not matched. */
904 }
905 
906 /**
907  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
908  *
909  * @filename: The filename to check.
910  * @pattern:  The pattern to compare.
911  *
912  * Returns true if matches, false otherwise.
913  *
914  * The following patterns are available.
915  *   \\     \ itself.
916  *   \ooo   Octal representation of a byte.
917  *   \*     Zero or more repetitions of characters other than '/'.
918  *   \@     Zero or more repetitions of characters other than '/' or '.'.
919  *   \?     1 byte character other than '/'.
920  *   \$     One or more repetitions of decimal digits.
921  *   \+     1 decimal digit.
922  *   \X     One or more repetitions of hexadecimal digits.
923  *   \x     1 hexadecimal digit.
924  *   \A     One or more repetitions of alphabet characters.
925  *   \a     1 alphabet character.
926  *
927  *   \-     Subtraction operator.
928  *
929  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
930  *               /dir/dir/dir/ ).
931  */
932 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
933 				 const struct tomoyo_path_info *pattern)
934 {
935 	const char *f = filename->name;
936 	const char *p = pattern->name;
937 	const int len = pattern->const_len;
938 
939 	/* If @pattern doesn't contain pattern, I can use strcmp(). */
940 	if (!pattern->is_patterned)
941 		return !tomoyo_pathcmp(filename, pattern);
942 	/* Don't compare directory and non-directory. */
943 	if (filename->is_dir != pattern->is_dir)
944 		return false;
945 	/* Compare the initial length without patterns. */
946 	if (strncmp(f, p, len))
947 		return false;
948 	f += len;
949 	p += len;
950 	return tomoyo_path_matches_pattern2(f, p);
951 }
952 
953 /**
954  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
955  *
956  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
957  *
958  * This function uses kzalloc(), so the caller must call kfree()
959  * if this function didn't return NULL.
960  */
961 const char *tomoyo_get_exe(void)
962 {
963 	struct file *exe_file;
964 	const char *cp;
965 	struct mm_struct *mm = current->mm;
966 
967 	if (!mm)
968 		return NULL;
969 	exe_file = get_mm_exe_file(mm);
970 	if (!exe_file)
971 		return NULL;
972 
973 	cp = tomoyo_realpath_from_path(&exe_file->f_path);
974 	fput(exe_file);
975 	return cp;
976 }
977 
978 /**
979  * tomoyo_get_mode - Get MAC mode.
980  *
981  * @ns:      Pointer to "struct tomoyo_policy_namespace".
982  * @profile: Profile number.
983  * @index:   Index number of functionality.
984  *
985  * Returns mode.
986  */
987 int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
988 		    const u8 index)
989 {
990 	u8 mode;
991 	struct tomoyo_profile *p;
992 
993 	if (!tomoyo_policy_loaded)
994 		return TOMOYO_CONFIG_DISABLED;
995 	p = tomoyo_profile(ns, profile);
996 	mode = p->config[index];
997 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
998 		mode = p->config[tomoyo_index2category[index]
999 				 + TOMOYO_MAX_MAC_INDEX];
1000 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
1001 		mode = p->default_config;
1002 	return mode & 3;
1003 }
1004 
1005 /**
1006  * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
1007  *
1008  * @r:      Pointer to "struct tomoyo_request_info" to initialize.
1009  * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
1010  * @index:  Index number of functionality.
1011  *
1012  * Returns mode.
1013  */
1014 int tomoyo_init_request_info(struct tomoyo_request_info *r,
1015 			     struct tomoyo_domain_info *domain, const u8 index)
1016 {
1017 	u8 profile;
1018 
1019 	memset(r, 0, sizeof(*r));
1020 	if (!domain)
1021 		domain = tomoyo_domain();
1022 	r->domain = domain;
1023 	profile = domain->profile;
1024 	r->profile = profile;
1025 	r->type = index;
1026 	r->mode = tomoyo_get_mode(domain->ns, profile, index);
1027 	return r->mode;
1028 }
1029 
1030 /**
1031  * tomoyo_domain_quota_is_ok - Check for domain's quota.
1032  *
1033  * @r: Pointer to "struct tomoyo_request_info".
1034  *
1035  * Returns true if the domain is not exceeded quota, false otherwise.
1036  *
1037  * Caller holds tomoyo_read_lock().
1038  */
1039 bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
1040 {
1041 	unsigned int count = 0;
1042 	struct tomoyo_domain_info *domain = r->domain;
1043 	struct tomoyo_acl_info *ptr;
1044 
1045 	if (r->mode != TOMOYO_CONFIG_LEARNING)
1046 		return false;
1047 	if (!domain)
1048 		return true;
1049 	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list,
1050 				srcu_read_lock_held(&tomoyo_ss)) {
1051 		u16 perm;
1052 		u8 i;
1053 
1054 		if (ptr->is_deleted)
1055 			continue;
1056 		switch (ptr->type) {
1057 		case TOMOYO_TYPE_PATH_ACL:
1058 			perm = container_of(ptr, struct tomoyo_path_acl, head)
1059 				->perm;
1060 			break;
1061 		case TOMOYO_TYPE_PATH2_ACL:
1062 			perm = container_of(ptr, struct tomoyo_path2_acl, head)
1063 				->perm;
1064 			break;
1065 		case TOMOYO_TYPE_PATH_NUMBER_ACL:
1066 			perm = container_of(ptr, struct tomoyo_path_number_acl,
1067 					    head)->perm;
1068 			break;
1069 		case TOMOYO_TYPE_MKDEV_ACL:
1070 			perm = container_of(ptr, struct tomoyo_mkdev_acl,
1071 					    head)->perm;
1072 			break;
1073 		case TOMOYO_TYPE_INET_ACL:
1074 			perm = container_of(ptr, struct tomoyo_inet_acl,
1075 					    head)->perm;
1076 			break;
1077 		case TOMOYO_TYPE_UNIX_ACL:
1078 			perm = container_of(ptr, struct tomoyo_unix_acl,
1079 					    head)->perm;
1080 			break;
1081 		case TOMOYO_TYPE_MANUAL_TASK_ACL:
1082 			perm = 0;
1083 			break;
1084 		default:
1085 			perm = 1;
1086 		}
1087 		for (i = 0; i < 16; i++)
1088 			if (perm & (1 << i))
1089 				count++;
1090 	}
1091 	if (count < tomoyo_profile(domain->ns, domain->profile)->
1092 	    pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
1093 		return true;
1094 	if (!domain->flags[TOMOYO_DIF_QUOTA_WARNED]) {
1095 		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 	}
1103 	return false;
1104 }
1105