xref: /openbmc/linux/security/tomoyo/util.c (revision f66501dc) 
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 /**
147  * tomoyo_get_domainname - Read a domainname from a line.
148  *
149  * @param: Pointer to "struct tomoyo_acl_param".
150  *
151  * Returns a domainname on success, NULL otherwise.
152  */
153 const struct tomoyo_path_info *tomoyo_get_domainname
154 (struct tomoyo_acl_param *param)
155 {
156 	char *start = param->data;
157 	char *pos = start;
158 
159 	while (*pos) {
160 		if (*pos++ != ' ' || *pos++ == '/')
161 			continue;
162 		pos -= 2;
163 		*pos++ = '\0';
164 		break;
165 	}
166 	param->data = pos;
167 	if (tomoyo_correct_domain(start))
168 		return tomoyo_get_name(start);
169 	return NULL;
170 }
171 
172 /**
173  * tomoyo_parse_ulong - Parse an "unsigned long" value.
174  *
175  * @result: Pointer to "unsigned long".
176  * @str:    Pointer to string to parse.
177  *
178  * Returns one of values in "enum tomoyo_value_type".
179  *
180  * The @src is updated to point the first character after the value
181  * on success.
182  */
183 u8 tomoyo_parse_ulong(unsigned long *result, char **str)
184 {
185 	const char *cp = *str;
186 	char *ep;
187 	int base = 10;
188 
189 	if (*cp == '0') {
190 		char c = *(cp + 1);
191 
192 		if (c == 'x' || c == 'X') {
193 			base = 16;
194 			cp += 2;
195 		} else if (c >= '0' && c <= '7') {
196 			base = 8;
197 			cp++;
198 		}
199 	}
200 	*result = simple_strtoul(cp, &ep, base);
201 	if (cp == ep)
202 		return TOMOYO_VALUE_TYPE_INVALID;
203 	*str = ep;
204 	switch (base) {
205 	case 16:
206 		return TOMOYO_VALUE_TYPE_HEXADECIMAL;
207 	case 8:
208 		return TOMOYO_VALUE_TYPE_OCTAL;
209 	default:
210 		return TOMOYO_VALUE_TYPE_DECIMAL;
211 	}
212 }
213 
214 /**
215  * tomoyo_print_ulong - Print an "unsigned long" value.
216  *
217  * @buffer:     Pointer to buffer.
218  * @buffer_len: Size of @buffer.
219  * @value:      An "unsigned long" value.
220  * @type:       Type of @value.
221  *
222  * Returns nothing.
223  */
224 void tomoyo_print_ulong(char *buffer, const int buffer_len,
225 			const unsigned long value, const u8 type)
226 {
227 	if (type == TOMOYO_VALUE_TYPE_DECIMAL)
228 		snprintf(buffer, buffer_len, "%lu", value);
229 	else if (type == TOMOYO_VALUE_TYPE_OCTAL)
230 		snprintf(buffer, buffer_len, "0%lo", value);
231 	else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL)
232 		snprintf(buffer, buffer_len, "0x%lX", value);
233 	else
234 		snprintf(buffer, buffer_len, "type(%u)", type);
235 }
236 
237 /**
238  * tomoyo_parse_name_union - Parse a tomoyo_name_union.
239  *
240  * @param: Pointer to "struct tomoyo_acl_param".
241  * @ptr:   Pointer to "struct tomoyo_name_union".
242  *
243  * Returns true on success, false otherwise.
244  */
245 bool tomoyo_parse_name_union(struct tomoyo_acl_param *param,
246 			     struct tomoyo_name_union *ptr)
247 {
248 	char *filename;
249 
250 	if (param->data[0] == '@') {
251 		param->data++;
252 		ptr->group = tomoyo_get_group(param, TOMOYO_PATH_GROUP);
253 		return ptr->group != NULL;
254 	}
255 	filename = tomoyo_read_token(param);
256 	if (!tomoyo_correct_word(filename))
257 		return false;
258 	ptr->filename = tomoyo_get_name(filename);
259 	return ptr->filename != NULL;
260 }
261 
262 /**
263  * tomoyo_parse_number_union - Parse a tomoyo_number_union.
264  *
265  * @param: Pointer to "struct tomoyo_acl_param".
266  * @ptr:   Pointer to "struct tomoyo_number_union".
267  *
268  * Returns true on success, false otherwise.
269  */
270 bool tomoyo_parse_number_union(struct tomoyo_acl_param *param,
271 			       struct tomoyo_number_union *ptr)
272 {
273 	char *data;
274 	u8 type;
275 	unsigned long v;
276 
277 	memset(ptr, 0, sizeof(*ptr));
278 	if (param->data[0] == '@') {
279 		param->data++;
280 		ptr->group = tomoyo_get_group(param, TOMOYO_NUMBER_GROUP);
281 		return ptr->group != NULL;
282 	}
283 	data = tomoyo_read_token(param);
284 	type = tomoyo_parse_ulong(&v, &data);
285 	if (type == TOMOYO_VALUE_TYPE_INVALID)
286 		return false;
287 	ptr->values[0] = v;
288 	ptr->value_type[0] = type;
289 	if (!*data) {
290 		ptr->values[1] = v;
291 		ptr->value_type[1] = type;
292 		return true;
293 	}
294 	if (*data++ != '-')
295 		return false;
296 	type = tomoyo_parse_ulong(&v, &data);
297 	if (type == TOMOYO_VALUE_TYPE_INVALID || *data || ptr->values[0] > v)
298 		return false;
299 	ptr->values[1] = v;
300 	ptr->value_type[1] = type;
301 	return true;
302 }
303 
304 /**
305  * tomoyo_byte_range - Check whether the string is a \ooo style octal value.
306  *
307  * @str: Pointer to the string.
308  *
309  * Returns true if @str is a \ooo style octal value, false otherwise.
310  *
311  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
312  * This function verifies that \ooo is in valid range.
313  */
314 static inline bool tomoyo_byte_range(const char *str)
315 {
316 	return *str >= '0' && *str++ <= '3' &&
317 		*str >= '0' && *str++ <= '7' &&
318 		*str >= '0' && *str <= '7';
319 }
320 
321 /**
322  * tomoyo_alphabet_char - Check whether the character is an alphabet.
323  *
324  * @c: The character to check.
325  *
326  * Returns true if @c is an alphabet character, false otherwise.
327  */
328 static inline bool tomoyo_alphabet_char(const char c)
329 {
330 	return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
331 }
332 
333 /**
334  * tomoyo_make_byte - Make byte value from three octal characters.
335  *
336  * @c1: The first character.
337  * @c2: The second character.
338  * @c3: The third character.
339  *
340  * Returns byte value.
341  */
342 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
343 {
344 	return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
345 }
346 
347 /**
348  * tomoyo_valid - Check whether the character is a valid char.
349  *
350  * @c: The character to check.
351  *
352  * Returns true if @c is a valid character, false otherwise.
353  */
354 static inline bool tomoyo_valid(const unsigned char c)
355 {
356 	return c > ' ' && c < 127;
357 }
358 
359 /**
360  * tomoyo_invalid - Check whether the character is an invalid char.
361  *
362  * @c: The character to check.
363  *
364  * Returns true if @c is an invalid character, false otherwise.
365  */
366 static inline bool tomoyo_invalid(const unsigned char c)
367 {
368 	return c && (c <= ' ' || c >= 127);
369 }
370 
371 /**
372  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
373  *
374  * @src:  Pointer to pointer to the string.
375  * @find: Pointer to the keyword.
376  *
377  * Returns true if @src starts with @find, false otherwise.
378  *
379  * The @src is updated to point the first character after the @find
380  * if @src starts with @find.
381  */
382 bool tomoyo_str_starts(char **src, const char *find)
383 {
384 	const int len = strlen(find);
385 	char *tmp = *src;
386 
387 	if (strncmp(tmp, find, len))
388 		return false;
389 	tmp += len;
390 	*src = tmp;
391 	return true;
392 }
393 
394 /**
395  * tomoyo_normalize_line - Format string.
396  *
397  * @buffer: The line to normalize.
398  *
399  * Leading and trailing whitespaces are removed.
400  * Multiple whitespaces are packed into single space.
401  *
402  * Returns nothing.
403  */
404 void tomoyo_normalize_line(unsigned char *buffer)
405 {
406 	unsigned char *sp = buffer;
407 	unsigned char *dp = buffer;
408 	bool first = true;
409 
410 	while (tomoyo_invalid(*sp))
411 		sp++;
412 	while (*sp) {
413 		if (!first)
414 			*dp++ = ' ';
415 		first = false;
416 		while (tomoyo_valid(*sp))
417 			*dp++ = *sp++;
418 		while (tomoyo_invalid(*sp))
419 			sp++;
420 	}
421 	*dp = '\0';
422 }
423 
424 /**
425  * tomoyo_correct_word2 - Validate a string.
426  *
427  * @string: The string to check. Maybe non-'\0'-terminated.
428  * @len:    Length of @string.
429  *
430  * Check whether the given string follows the naming rules.
431  * Returns true if @string follows the naming rules, false otherwise.
432  */
433 static bool tomoyo_correct_word2(const char *string, size_t len)
434 {
435 	const char *const start = string;
436 	bool in_repetition = false;
437 	unsigned char c;
438 	unsigned char d;
439 	unsigned char e;
440 
441 	if (!len)
442 		goto out;
443 	while (len--) {
444 		c = *string++;
445 		if (c == '\\') {
446 			if (!len--)
447 				goto out;
448 			c = *string++;
449 			switch (c) {
450 			case '\\':  /* "\\" */
451 				continue;
452 			case '$':   /* "\$" */
453 			case '+':   /* "\+" */
454 			case '?':   /* "\?" */
455 			case '*':   /* "\*" */
456 			case '@':   /* "\@" */
457 			case 'x':   /* "\x" */
458 			case 'X':   /* "\X" */
459 			case 'a':   /* "\a" */
460 			case 'A':   /* "\A" */
461 			case '-':   /* "\-" */
462 				continue;
463 			case '{':   /* "/\{" */
464 				if (string - 3 < start || *(string - 3) != '/')
465 					break;
466 				in_repetition = true;
467 				continue;
468 			case '}':   /* "\}/" */
469 				if (*string != '/')
470 					break;
471 				if (!in_repetition)
472 					break;
473 				in_repetition = false;
474 				continue;
475 			case '0':   /* "\ooo" */
476 			case '1':
477 			case '2':
478 			case '3':
479 				if (!len-- || !len--)
480 					break;
481 				d = *string++;
482 				e = *string++;
483 				if (d < '0' || d > '7' || e < '0' || e > '7')
484 					break;
485 				c = tomoyo_make_byte(c, d, e);
486 				if (c <= ' ' || c >= 127)
487 					continue;
488 			}
489 			goto out;
490 		} else if (in_repetition && c == '/') {
491 			goto out;
492 		} else if (c <= ' ' || c >= 127) {
493 			goto out;
494 		}
495 	}
496 	if (in_repetition)
497 		goto out;
498 	return true;
499  out:
500 	return false;
501 }
502 
503 /**
504  * tomoyo_correct_word - Validate a string.
505  *
506  * @string: The string to check.
507  *
508  * Check whether the given string follows the naming rules.
509  * Returns true if @string follows the naming rules, false otherwise.
510  */
511 bool tomoyo_correct_word(const char *string)
512 {
513 	return tomoyo_correct_word2(string, strlen(string));
514 }
515 
516 /**
517  * tomoyo_correct_path - Validate a pathname.
518  *
519  * @filename: The pathname to check.
520  *
521  * Check whether the given pathname follows the naming rules.
522  * Returns true if @filename follows the naming rules, false otherwise.
523  */
524 bool tomoyo_correct_path(const char *filename)
525 {
526 	return *filename == '/' && tomoyo_correct_word(filename);
527 }
528 
529 /**
530  * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.
531  *
532  * @domainname: The domainname to check.
533  *
534  * Returns true if @domainname follows the naming rules, false otherwise.
535  */
536 bool tomoyo_correct_domain(const unsigned char *domainname)
537 {
538 	if (!domainname || !tomoyo_domain_def(domainname))
539 		return false;
540 	domainname = strchr(domainname, ' ');
541 	if (!domainname++)
542 		return true;
543 	while (1) {
544 		const unsigned char *cp = strchr(domainname, ' ');
545 
546 		if (!cp)
547 			break;
548 		if (*domainname != '/' ||
549 		    !tomoyo_correct_word2(domainname, cp - domainname))
550 			return false;
551 		domainname = cp + 1;
552 	}
553 	return tomoyo_correct_path(domainname);
554 }
555 
556 /**
557  * tomoyo_domain_def - Check whether the given token can be a domainname.
558  *
559  * @buffer: The token to check.
560  *
561  * Returns true if @buffer possibly be a domainname, false otherwise.
562  */
563 bool tomoyo_domain_def(const unsigned char *buffer)
564 {
565 	const unsigned char *cp;
566 	int len;
567 
568 	if (*buffer != '<')
569 		return false;
570 	cp = strchr(buffer, ' ');
571 	if (!cp)
572 		len = strlen(buffer);
573 	else
574 		len = cp - buffer;
575 	if (buffer[len - 1] != '>' ||
576 	    !tomoyo_correct_word2(buffer + 1, len - 2))
577 		return false;
578 	return true;
579 }
580 
581 /**
582  * tomoyo_find_domain - Find a domain by the given name.
583  *
584  * @domainname: The domainname to find.
585  *
586  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
587  *
588  * Caller holds tomoyo_read_lock().
589  */
590 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
591 {
592 	struct tomoyo_domain_info *domain;
593 	struct tomoyo_path_info name;
594 
595 	name.name = domainname;
596 	tomoyo_fill_path_info(&name);
597 	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
598 		if (!domain->is_deleted &&
599 		    !tomoyo_pathcmp(&name, domain->domainname))
600 			return domain;
601 	}
602 	return NULL;
603 }
604 
605 /**
606  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
607  *
608  * @filename: The string to evaluate.
609  *
610  * Returns the initial length without a pattern in @filename.
611  */
612 static int tomoyo_const_part_length(const char *filename)
613 {
614 	char c;
615 	int len = 0;
616 
617 	if (!filename)
618 		return 0;
619 	while ((c = *filename++) != '\0') {
620 		if (c != '\\') {
621 			len++;
622 			continue;
623 		}
624 		c = *filename++;
625 		switch (c) {
626 		case '\\':  /* "\\" */
627 			len += 2;
628 			continue;
629 		case '0':   /* "\ooo" */
630 		case '1':
631 		case '2':
632 		case '3':
633 			c = *filename++;
634 			if (c < '0' || c > '7')
635 				break;
636 			c = *filename++;
637 			if (c < '0' || c > '7')
638 				break;
639 			len += 4;
640 			continue;
641 		}
642 		break;
643 	}
644 	return len;
645 }
646 
647 /**
648  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
649  *
650  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
651  *
652  * The caller sets "struct tomoyo_path_info"->name.
653  */
654 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
655 {
656 	const char *name = ptr->name;
657 	const int len = strlen(name);
658 
659 	ptr->const_len = tomoyo_const_part_length(name);
660 	ptr->is_dir = len && (name[len - 1] == '/');
661 	ptr->is_patterned = (ptr->const_len < len);
662 	ptr->hash = full_name_hash(NULL, name, len);
663 }
664 
665 /**
666  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
667  *
668  * @filename:     The start of string to check.
669  * @filename_end: The end of string to check.
670  * @pattern:      The start of pattern to compare.
671  * @pattern_end:  The end of pattern to compare.
672  *
673  * Returns true if @filename matches @pattern, false otherwise.
674  */
675 static bool tomoyo_file_matches_pattern2(const char *filename,
676 					 const char *filename_end,
677 					 const char *pattern,
678 					 const char *pattern_end)
679 {
680 	while (filename < filename_end && pattern < pattern_end) {
681 		char c;
682 		int i;
683 		int j;
684 
685 		if (*pattern != '\\') {
686 			if (*filename++ != *pattern++)
687 				return false;
688 			continue;
689 		}
690 		c = *filename;
691 		pattern++;
692 		switch (*pattern) {
693 		case '?':
694 			if (c == '/') {
695 				return false;
696 			} else if (c == '\\') {
697 				if (filename[1] == '\\')
698 					filename++;
699 				else if (tomoyo_byte_range(filename + 1))
700 					filename += 3;
701 				else
702 					return false;
703 			}
704 			break;
705 		case '\\':
706 			if (c != '\\')
707 				return false;
708 			if (*++filename != '\\')
709 				return false;
710 			break;
711 		case '+':
712 			if (!isdigit(c))
713 				return false;
714 			break;
715 		case 'x':
716 			if (!isxdigit(c))
717 				return false;
718 			break;
719 		case 'a':
720 			if (!tomoyo_alphabet_char(c))
721 				return false;
722 			break;
723 		case '0':
724 		case '1':
725 		case '2':
726 		case '3':
727 			if (c == '\\' && tomoyo_byte_range(filename + 1)
728 			    && strncmp(filename + 1, pattern, 3) == 0) {
729 				filename += 3;
730 				pattern += 2;
731 				break;
732 			}
733 			return false; /* Not matched. */
734 		case '*':
735 		case '@':
736 			for (i = 0; i <= filename_end - filename; i++) {
737 				if (tomoyo_file_matches_pattern2(
738 						    filename + i, filename_end,
739 						    pattern + 1, pattern_end))
740 					return true;
741 				c = filename[i];
742 				if (c == '.' && *pattern == '@')
743 					break;
744 				if (c != '\\')
745 					continue;
746 				if (filename[i + 1] == '\\')
747 					i++;
748 				else if (tomoyo_byte_range(filename + i + 1))
749 					i += 3;
750 				else
751 					break; /* Bad pattern. */
752 			}
753 			return false; /* Not matched. */
754 		default:
755 			j = 0;
756 			c = *pattern;
757 			if (c == '$') {
758 				while (isdigit(filename[j]))
759 					j++;
760 			} else if (c == 'X') {
761 				while (isxdigit(filename[j]))
762 					j++;
763 			} else if (c == 'A') {
764 				while (tomoyo_alphabet_char(filename[j]))
765 					j++;
766 			}
767 			for (i = 1; i <= j; i++) {
768 				if (tomoyo_file_matches_pattern2(
769 						    filename + i, filename_end,
770 						    pattern + 1, pattern_end))
771 					return true;
772 			}
773 			return false; /* Not matched or bad pattern. */
774 		}
775 		filename++;
776 		pattern++;
777 	}
778 	while (*pattern == '\\' &&
779 	       (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
780 		pattern += 2;
781 	return filename == filename_end && pattern == pattern_end;
782 }
783 
784 /**
785  * tomoyo_file_matches_pattern - Pattern matching without '/' character.
786  *
787  * @filename:     The start of string to check.
788  * @filename_end: The end of string to check.
789  * @pattern:      The start of pattern to compare.
790  * @pattern_end:  The end of pattern to compare.
791  *
792  * Returns true if @filename matches @pattern, false otherwise.
793  */
794 static bool tomoyo_file_matches_pattern(const char *filename,
795 					const char *filename_end,
796 					const char *pattern,
797 					const char *pattern_end)
798 {
799 	const char *pattern_start = pattern;
800 	bool first = true;
801 	bool result;
802 
803 	while (pattern < pattern_end - 1) {
804 		/* Split at "\-" pattern. */
805 		if (*pattern++ != '\\' || *pattern++ != '-')
806 			continue;
807 		result = tomoyo_file_matches_pattern2(filename,
808 						      filename_end,
809 						      pattern_start,
810 						      pattern - 2);
811 		if (first)
812 			result = !result;
813 		if (result)
814 			return false;
815 		first = false;
816 		pattern_start = pattern;
817 	}
818 	result = tomoyo_file_matches_pattern2(filename, filename_end,
819 					      pattern_start, pattern_end);
820 	return first ? result : !result;
821 }
822 
823 /**
824  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
825  *
826  * @f: The start of string to check.
827  * @p: The start of pattern to compare.
828  *
829  * Returns true if @f matches @p, false otherwise.
830  */
831 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
832 {
833 	const char *f_delimiter;
834 	const char *p_delimiter;
835 
836 	while (*f && *p) {
837 		f_delimiter = strchr(f, '/');
838 		if (!f_delimiter)
839 			f_delimiter = f + strlen(f);
840 		p_delimiter = strchr(p, '/');
841 		if (!p_delimiter)
842 			p_delimiter = p + strlen(p);
843 		if (*p == '\\' && *(p + 1) == '{')
844 			goto recursive;
845 		if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
846 						 p_delimiter))
847 			return false;
848 		f = f_delimiter;
849 		if (*f)
850 			f++;
851 		p = p_delimiter;
852 		if (*p)
853 			p++;
854 	}
855 	/* Ignore trailing "\*" and "\@" in @pattern. */
856 	while (*p == '\\' &&
857 	       (*(p + 1) == '*' || *(p + 1) == '@'))
858 		p += 2;
859 	return !*f && !*p;
860  recursive:
861 	/*
862 	 * The "\{" pattern is permitted only after '/' character.
863 	 * This guarantees that below "*(p - 1)" is safe.
864 	 * Also, the "\}" pattern is permitted only before '/' character
865 	 * so that "\{" + "\}" pair will not break the "\-" operator.
866 	 */
867 	if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
868 	    *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
869 		return false; /* Bad pattern. */
870 	do {
871 		/* Compare current component with pattern. */
872 		if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
873 						 p_delimiter - 2))
874 			break;
875 		/* Proceed to next component. */
876 		f = f_delimiter;
877 		if (!*f)
878 			break;
879 		f++;
880 		/* Continue comparison. */
881 		if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
882 			return true;
883 		f_delimiter = strchr(f, '/');
884 	} while (f_delimiter);
885 	return false; /* Not matched. */
886 }
887 
888 /**
889  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
890  *
891  * @filename: The filename to check.
892  * @pattern:  The pattern to compare.
893  *
894  * Returns true if matches, false otherwise.
895  *
896  * The following patterns are available.
897  *   \\     \ itself.
898  *   \ooo   Octal representation of a byte.
899  *   \*     Zero or more repetitions of characters other than '/'.
900  *   \@     Zero or more repetitions of characters other than '/' or '.'.
901  *   \?     1 byte character other than '/'.
902  *   \$     One or more repetitions of decimal digits.
903  *   \+     1 decimal digit.
904  *   \X     One or more repetitions of hexadecimal digits.
905  *   \x     1 hexadecimal digit.
906  *   \A     One or more repetitions of alphabet characters.
907  *   \a     1 alphabet character.
908  *
909  *   \-     Subtraction operator.
910  *
911  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
912  *               /dir/dir/dir/ ).
913  */
914 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
915 				 const struct tomoyo_path_info *pattern)
916 {
917 	const char *f = filename->name;
918 	const char *p = pattern->name;
919 	const int len = pattern->const_len;
920 
921 	/* If @pattern doesn't contain pattern, I can use strcmp(). */
922 	if (!pattern->is_patterned)
923 		return !tomoyo_pathcmp(filename, pattern);
924 	/* Don't compare directory and non-directory. */
925 	if (filename->is_dir != pattern->is_dir)
926 		return false;
927 	/* Compare the initial length without patterns. */
928 	if (strncmp(f, p, len))
929 		return false;
930 	f += len;
931 	p += len;
932 	return tomoyo_path_matches_pattern2(f, p);
933 }
934 
935 /**
936  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
937  *
938  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
939  *
940  * This function uses kzalloc(), so the caller must call kfree()
941  * if this function didn't return NULL.
942  */
943 const char *tomoyo_get_exe(void)
944 {
945 	struct file *exe_file;
946 	const char *cp;
947 	struct mm_struct *mm = current->mm;
948 
949 	if (!mm)
950 		return NULL;
951 	exe_file = get_mm_exe_file(mm);
952 	if (!exe_file)
953 		return NULL;
954 
955 	cp = tomoyo_realpath_from_path(&exe_file->f_path);
956 	fput(exe_file);
957 	return cp;
958 }
959 
960 /**
961  * tomoyo_get_mode - Get MAC mode.
962  *
963  * @ns:      Pointer to "struct tomoyo_policy_namespace".
964  * @profile: Profile number.
965  * @index:   Index number of functionality.
966  *
967  * Returns mode.
968  */
969 int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
970 		    const u8 index)
971 {
972 	u8 mode;
973 	struct tomoyo_profile *p;
974 
975 	if (!tomoyo_policy_loaded)
976 		return TOMOYO_CONFIG_DISABLED;
977 	p = tomoyo_profile(ns, profile);
978 	mode = p->config[index];
979 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
980 		mode = p->config[tomoyo_index2category[index]
981 				 + TOMOYO_MAX_MAC_INDEX];
982 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
983 		mode = p->default_config;
984 	return mode & 3;
985 }
986 
987 /**
988  * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
989  *
990  * @r:      Pointer to "struct tomoyo_request_info" to initialize.
991  * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
992  * @index:  Index number of functionality.
993  *
994  * Returns mode.
995  */
996 int tomoyo_init_request_info(struct tomoyo_request_info *r,
997 			     struct tomoyo_domain_info *domain, const u8 index)
998 {
999 	u8 profile;
1000 
1001 	memset(r, 0, sizeof(*r));
1002 	if (!domain)
1003 		domain = tomoyo_domain();
1004 	r->domain = domain;
1005 	profile = domain->profile;
1006 	r->profile = profile;
1007 	r->type = index;
1008 	r->mode = tomoyo_get_mode(domain->ns, profile, index);
1009 	return r->mode;
1010 }
1011 
1012 /**
1013  * tomoyo_domain_quota_is_ok - Check for domain's quota.
1014  *
1015  * @r: Pointer to "struct tomoyo_request_info".
1016  *
1017  * Returns true if the domain is not exceeded quota, false otherwise.
1018  *
1019  * Caller holds tomoyo_read_lock().
1020  */
1021 bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
1022 {
1023 	unsigned int count = 0;
1024 	struct tomoyo_domain_info *domain = r->domain;
1025 	struct tomoyo_acl_info *ptr;
1026 
1027 	if (r->mode != TOMOYO_CONFIG_LEARNING)
1028 		return false;
1029 	if (!domain)
1030 		return true;
1031 	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
1032 		u16 perm;
1033 		u8 i;
1034 
1035 		if (ptr->is_deleted)
1036 			continue;
1037 		switch (ptr->type) {
1038 		case TOMOYO_TYPE_PATH_ACL:
1039 			perm = container_of(ptr, struct tomoyo_path_acl, head)
1040 				->perm;
1041 			break;
1042 		case TOMOYO_TYPE_PATH2_ACL:
1043 			perm = container_of(ptr, struct tomoyo_path2_acl, head)
1044 				->perm;
1045 			break;
1046 		case TOMOYO_TYPE_PATH_NUMBER_ACL:
1047 			perm = container_of(ptr, struct tomoyo_path_number_acl,
1048 					    head)->perm;
1049 			break;
1050 		case TOMOYO_TYPE_MKDEV_ACL:
1051 			perm = container_of(ptr, struct tomoyo_mkdev_acl,
1052 					    head)->perm;
1053 			break;
1054 		case TOMOYO_TYPE_INET_ACL:
1055 			perm = container_of(ptr, struct tomoyo_inet_acl,
1056 					    head)->perm;
1057 			break;
1058 		case TOMOYO_TYPE_UNIX_ACL:
1059 			perm = container_of(ptr, struct tomoyo_unix_acl,
1060 					    head)->perm;
1061 			break;
1062 		case TOMOYO_TYPE_MANUAL_TASK_ACL:
1063 			perm = 0;
1064 			break;
1065 		default:
1066 			perm = 1;
1067 		}
1068 		for (i = 0; i < 16; i++)
1069 			if (perm & (1 << i))
1070 				count++;
1071 	}
1072 	if (count < tomoyo_profile(domain->ns, domain->profile)->
1073 	    pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
1074 		return true;
1075 	if (!domain->flags[TOMOYO_DIF_QUOTA_WARNED]) {
1076 		domain->flags[TOMOYO_DIF_QUOTA_WARNED] = true;
1077 		/* r->granted = false; */
1078 		tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
1079 #ifndef CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING
1080 		pr_warn("WARNING: Domain '%s' has too many ACLs to hold. Stopped learning mode.\n",
1081 			domain->domainname->name);
1082 #endif
1083 	}
1084 	return false;
1085 }
1086