xref: /openbmc/linux/security/tomoyo/util.c (revision f9834f18) 
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 				srcu_read_lock_held(&tomoyo_ss)) {
599 		if (!domain->is_deleted &&
600 		    !tomoyo_pathcmp(&name, domain->domainname))
601 			return domain;
602 	}
603 	return NULL;
604 }
605 
606 /**
607  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
608  *
609  * @filename: The string to evaluate.
610  *
611  * Returns the initial length without a pattern in @filename.
612  */
613 static int tomoyo_const_part_length(const char *filename)
614 {
615 	char c;
616 	int len = 0;
617 
618 	if (!filename)
619 		return 0;
620 	while ((c = *filename++) != '\0') {
621 		if (c != '\\') {
622 			len++;
623 			continue;
624 		}
625 		c = *filename++;
626 		switch (c) {
627 		case '\\':  /* "\\" */
628 			len += 2;
629 			continue;
630 		case '0':   /* "\ooo" */
631 		case '1':
632 		case '2':
633 		case '3':
634 			c = *filename++;
635 			if (c < '0' || c > '7')
636 				break;
637 			c = *filename++;
638 			if (c < '0' || c > '7')
639 				break;
640 			len += 4;
641 			continue;
642 		}
643 		break;
644 	}
645 	return len;
646 }
647 
648 /**
649  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
650  *
651  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
652  *
653  * The caller sets "struct tomoyo_path_info"->name.
654  */
655 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
656 {
657 	const char *name = ptr->name;
658 	const int len = strlen(name);
659 
660 	ptr->const_len = tomoyo_const_part_length(name);
661 	ptr->is_dir = len && (name[len - 1] == '/');
662 	ptr->is_patterned = (ptr->const_len < len);
663 	ptr->hash = full_name_hash(NULL, name, len);
664 }
665 
666 /**
667  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
668  *
669  * @filename:     The start of string to check.
670  * @filename_end: The end of string to check.
671  * @pattern:      The start of pattern to compare.
672  * @pattern_end:  The end of pattern to compare.
673  *
674  * Returns true if @filename matches @pattern, false otherwise.
675  */
676 static bool tomoyo_file_matches_pattern2(const char *filename,
677 					 const char *filename_end,
678 					 const char *pattern,
679 					 const char *pattern_end)
680 {
681 	while (filename < filename_end && pattern < pattern_end) {
682 		char c;
683 		int i;
684 		int j;
685 
686 		if (*pattern != '\\') {
687 			if (*filename++ != *pattern++)
688 				return false;
689 			continue;
690 		}
691 		c = *filename;
692 		pattern++;
693 		switch (*pattern) {
694 		case '?':
695 			if (c == '/') {
696 				return false;
697 			} else if (c == '\\') {
698 				if (filename[1] == '\\')
699 					filename++;
700 				else if (tomoyo_byte_range(filename + 1))
701 					filename += 3;
702 				else
703 					return false;
704 			}
705 			break;
706 		case '\\':
707 			if (c != '\\')
708 				return false;
709 			if (*++filename != '\\')
710 				return false;
711 			break;
712 		case '+':
713 			if (!isdigit(c))
714 				return false;
715 			break;
716 		case 'x':
717 			if (!isxdigit(c))
718 				return false;
719 			break;
720 		case 'a':
721 			if (!tomoyo_alphabet_char(c))
722 				return false;
723 			break;
724 		case '0':
725 		case '1':
726 		case '2':
727 		case '3':
728 			if (c == '\\' && tomoyo_byte_range(filename + 1)
729 			    && strncmp(filename + 1, pattern, 3) == 0) {
730 				filename += 3;
731 				pattern += 2;
732 				break;
733 			}
734 			return false; /* Not matched. */
735 		case '*':
736 		case '@':
737 			for (i = 0; i <= filename_end - filename; i++) {
738 				if (tomoyo_file_matches_pattern2(
739 						    filename + i, filename_end,
740 						    pattern + 1, pattern_end))
741 					return true;
742 				c = filename[i];
743 				if (c == '.' && *pattern == '@')
744 					break;
745 				if (c != '\\')
746 					continue;
747 				if (filename[i + 1] == '\\')
748 					i++;
749 				else if (tomoyo_byte_range(filename + i + 1))
750 					i += 3;
751 				else
752 					break; /* Bad pattern. */
753 			}
754 			return false; /* Not matched. */
755 		default:
756 			j = 0;
757 			c = *pattern;
758 			if (c == '$') {
759 				while (isdigit(filename[j]))
760 					j++;
761 			} else if (c == 'X') {
762 				while (isxdigit(filename[j]))
763 					j++;
764 			} else if (c == 'A') {
765 				while (tomoyo_alphabet_char(filename[j]))
766 					j++;
767 			}
768 			for (i = 1; i <= j; i++) {
769 				if (tomoyo_file_matches_pattern2(
770 						    filename + i, filename_end,
771 						    pattern + 1, pattern_end))
772 					return true;
773 			}
774 			return false; /* Not matched or bad pattern. */
775 		}
776 		filename++;
777 		pattern++;
778 	}
779 	while (*pattern == '\\' &&
780 	       (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
781 		pattern += 2;
782 	return filename == filename_end && pattern == pattern_end;
783 }
784 
785 /**
786  * tomoyo_file_matches_pattern - Pattern matching without '/' character.
787  *
788  * @filename:     The start of string to check.
789  * @filename_end: The end of string to check.
790  * @pattern:      The start of pattern to compare.
791  * @pattern_end:  The end of pattern to compare.
792  *
793  * Returns true if @filename matches @pattern, false otherwise.
794  */
795 static bool tomoyo_file_matches_pattern(const char *filename,
796 					const char *filename_end,
797 					const char *pattern,
798 					const char *pattern_end)
799 {
800 	const char *pattern_start = pattern;
801 	bool first = true;
802 	bool result;
803 
804 	while (pattern < pattern_end - 1) {
805 		/* Split at "\-" pattern. */
806 		if (*pattern++ != '\\' || *pattern++ != '-')
807 			continue;
808 		result = tomoyo_file_matches_pattern2(filename,
809 						      filename_end,
810 						      pattern_start,
811 						      pattern - 2);
812 		if (first)
813 			result = !result;
814 		if (result)
815 			return false;
816 		first = false;
817 		pattern_start = pattern;
818 	}
819 	result = tomoyo_file_matches_pattern2(filename, filename_end,
820 					      pattern_start, pattern_end);
821 	return first ? result : !result;
822 }
823 
824 /**
825  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
826  *
827  * @f: The start of string to check.
828  * @p: The start of pattern to compare.
829  *
830  * Returns true if @f matches @p, false otherwise.
831  */
832 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
833 {
834 	const char *f_delimiter;
835 	const char *p_delimiter;
836 
837 	while (*f && *p) {
838 		f_delimiter = strchr(f, '/');
839 		if (!f_delimiter)
840 			f_delimiter = f + strlen(f);
841 		p_delimiter = strchr(p, '/');
842 		if (!p_delimiter)
843 			p_delimiter = p + strlen(p);
844 		if (*p == '\\' && *(p + 1) == '{')
845 			goto recursive;
846 		if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
847 						 p_delimiter))
848 			return false;
849 		f = f_delimiter;
850 		if (*f)
851 			f++;
852 		p = p_delimiter;
853 		if (*p)
854 			p++;
855 	}
856 	/* Ignore trailing "\*" and "\@" in @pattern. */
857 	while (*p == '\\' &&
858 	       (*(p + 1) == '*' || *(p + 1) == '@'))
859 		p += 2;
860 	return !*f && !*p;
861  recursive:
862 	/*
863 	 * The "\{" pattern is permitted only after '/' character.
864 	 * This guarantees that below "*(p - 1)" is safe.
865 	 * Also, the "\}" pattern is permitted only before '/' character
866 	 * so that "\{" + "\}" pair will not break the "\-" operator.
867 	 */
868 	if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
869 	    *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
870 		return false; /* Bad pattern. */
871 	do {
872 		/* Compare current component with pattern. */
873 		if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
874 						 p_delimiter - 2))
875 			break;
876 		/* Proceed to next component. */
877 		f = f_delimiter;
878 		if (!*f)
879 			break;
880 		f++;
881 		/* Continue comparison. */
882 		if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
883 			return true;
884 		f_delimiter = strchr(f, '/');
885 	} while (f_delimiter);
886 	return false; /* Not matched. */
887 }
888 
889 /**
890  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
891  *
892  * @filename: The filename to check.
893  * @pattern:  The pattern to compare.
894  *
895  * Returns true if matches, false otherwise.
896  *
897  * The following patterns are available.
898  *   \\     \ itself.
899  *   \ooo   Octal representation of a byte.
900  *   \*     Zero or more repetitions of characters other than '/'.
901  *   \@     Zero or more repetitions of characters other than '/' or '.'.
902  *   \?     1 byte character other than '/'.
903  *   \$     One or more repetitions of decimal digits.
904  *   \+     1 decimal digit.
905  *   \X     One or more repetitions of hexadecimal digits.
906  *   \x     1 hexadecimal digit.
907  *   \A     One or more repetitions of alphabet characters.
908  *   \a     1 alphabet character.
909  *
910  *   \-     Subtraction operator.
911  *
912  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
913  *               /dir/dir/dir/ ).
914  */
915 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
916 				 const struct tomoyo_path_info *pattern)
917 {
918 	const char *f = filename->name;
919 	const char *p = pattern->name;
920 	const int len = pattern->const_len;
921 
922 	/* If @pattern doesn't contain pattern, I can use strcmp(). */
923 	if (!pattern->is_patterned)
924 		return !tomoyo_pathcmp(filename, pattern);
925 	/* Don't compare directory and non-directory. */
926 	if (filename->is_dir != pattern->is_dir)
927 		return false;
928 	/* Compare the initial length without patterns. */
929 	if (strncmp(f, p, len))
930 		return false;
931 	f += len;
932 	p += len;
933 	return tomoyo_path_matches_pattern2(f, p);
934 }
935 
936 /**
937  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
938  *
939  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
940  *
941  * This function uses kzalloc(), so the caller must call kfree()
942  * if this function didn't return NULL.
943  */
944 const char *tomoyo_get_exe(void)
945 {
946 	struct file *exe_file;
947 	const char *cp;
948 	struct mm_struct *mm = current->mm;
949 
950 	if (!mm)
951 		return NULL;
952 	exe_file = get_mm_exe_file(mm);
953 	if (!exe_file)
954 		return NULL;
955 
956 	cp = tomoyo_realpath_from_path(&exe_file->f_path);
957 	fput(exe_file);
958 	return cp;
959 }
960 
961 /**
962  * tomoyo_get_mode - Get MAC mode.
963  *
964  * @ns:      Pointer to "struct tomoyo_policy_namespace".
965  * @profile: Profile number.
966  * @index:   Index number of functionality.
967  *
968  * Returns mode.
969  */
970 int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
971 		    const u8 index)
972 {
973 	u8 mode;
974 	struct tomoyo_profile *p;
975 
976 	if (!tomoyo_policy_loaded)
977 		return TOMOYO_CONFIG_DISABLED;
978 	p = tomoyo_profile(ns, profile);
979 	mode = p->config[index];
980 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
981 		mode = p->config[tomoyo_index2category[index]
982 				 + TOMOYO_MAX_MAC_INDEX];
983 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
984 		mode = p->default_config;
985 	return mode & 3;
986 }
987 
988 /**
989  * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
990  *
991  * @r:      Pointer to "struct tomoyo_request_info" to initialize.
992  * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
993  * @index:  Index number of functionality.
994  *
995  * Returns mode.
996  */
997 int tomoyo_init_request_info(struct tomoyo_request_info *r,
998 			     struct tomoyo_domain_info *domain, const u8 index)
999 {
1000 	u8 profile;
1001 
1002 	memset(r, 0, sizeof(*r));
1003 	if (!domain)
1004 		domain = tomoyo_domain();
1005 	r->domain = domain;
1006 	profile = domain->profile;
1007 	r->profile = profile;
1008 	r->type = index;
1009 	r->mode = tomoyo_get_mode(domain->ns, profile, index);
1010 	return r->mode;
1011 }
1012 
1013 /**
1014  * tomoyo_domain_quota_is_ok - Check for domain's quota.
1015  *
1016  * @r: Pointer to "struct tomoyo_request_info".
1017  *
1018  * Returns true if the domain is not exceeded quota, false otherwise.
1019  *
1020  * Caller holds tomoyo_read_lock().
1021  */
1022 bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
1023 {
1024 	unsigned int count = 0;
1025 	struct tomoyo_domain_info *domain = r->domain;
1026 	struct tomoyo_acl_info *ptr;
1027 
1028 	if (r->mode != TOMOYO_CONFIG_LEARNING)
1029 		return false;
1030 	if (!domain)
1031 		return true;
1032 	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list,
1033 				srcu_read_lock_held(&tomoyo_ss)) {
1034 		u16 perm;
1035 		u8 i;
1036 
1037 		if (ptr->is_deleted)
1038 			continue;
1039 		switch (ptr->type) {
1040 		case TOMOYO_TYPE_PATH_ACL:
1041 			perm = container_of(ptr, struct tomoyo_path_acl, head)
1042 				->perm;
1043 			break;
1044 		case TOMOYO_TYPE_PATH2_ACL:
1045 			perm = container_of(ptr, struct tomoyo_path2_acl, head)
1046 				->perm;
1047 			break;
1048 		case TOMOYO_TYPE_PATH_NUMBER_ACL:
1049 			perm = container_of(ptr, struct tomoyo_path_number_acl,
1050 					    head)->perm;
1051 			break;
1052 		case TOMOYO_TYPE_MKDEV_ACL:
1053 			perm = container_of(ptr, struct tomoyo_mkdev_acl,
1054 					    head)->perm;
1055 			break;
1056 		case TOMOYO_TYPE_INET_ACL:
1057 			perm = container_of(ptr, struct tomoyo_inet_acl,
1058 					    head)->perm;
1059 			break;
1060 		case TOMOYO_TYPE_UNIX_ACL:
1061 			perm = container_of(ptr, struct tomoyo_unix_acl,
1062 					    head)->perm;
1063 			break;
1064 		case TOMOYO_TYPE_MANUAL_TASK_ACL:
1065 			perm = 0;
1066 			break;
1067 		default:
1068 			perm = 1;
1069 		}
1070 		for (i = 0; i < 16; i++)
1071 			if (perm & (1 << i))
1072 				count++;
1073 	}
1074 	if (count < tomoyo_profile(domain->ns, domain->profile)->
1075 	    pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
1076 		return true;
1077 	if (!domain->flags[TOMOYO_DIF_QUOTA_WARNED]) {
1078 		domain->flags[TOMOYO_DIF_QUOTA_WARNED] = true;
1079 		/* r->granted = false; */
1080 		tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
1081 #ifndef CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING
1082 		pr_warn("WARNING: Domain '%s' has too many ACLs to hold. Stopped learning mode.\n",
1083 			domain->domainname->name);
1084 #endif
1085 	}
1086 	return false;
1087 }
1088