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. */
14DEFINE_MUTEX(tomoyo_policy_lock);
15
16/* Has /sbin/init started? */
17bool tomoyo_policy_loaded;
18
19/*
20 * Mapping table from "enum tomoyo_mac_index" to
21 * "enum tomoyo_mac_category_index".
22 */
23const 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 * @time64: Seconds since 1970/01/01 00:00:00.
87 * @stamp:  Pointer to "struct tomoyo_time".
88 *
89 * Returns nothing.
90 */
91void 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 */
114bool 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 */
133char *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
146static 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 */
155const 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 */
185u8 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 */
226void 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 */
247bool 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 */
272bool 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 */
316static 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 */
330static 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 */
344static 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 */
356static 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 */
368static 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 */
384bool 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 */
406void 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 */
435static bool tomoyo_correct_word2(const char *string, size_t len)
436{
437	u8 recursion = 20;
438	const char *const start = string;
439	bool in_repetition = false;
440
441	if (!len)
442		goto out;
443	while (len--) {
444		unsigned char c = *string++;
445
446		if (c == '\\') {
447			if (!len--)
448				goto out;
449			c = *string++;
450			if (c >= '0' && c <= '3') {
451				unsigned char d;
452				unsigned char e;
453
454				if (!len-- || !len--)
455					goto out;
456				d = *string++;
457				e = *string++;
458				if (d < '0' || d > '7' || e < '0' || e > '7')
459					goto out;
460				c = tomoyo_make_byte(c, d, e);
461				if (c <= ' ' || c >= 127)
462					continue;
463				goto out;
464			}
465			switch (c) {
466			case '\\':  /* "\\" */
467			case '+':   /* "\+" */
468			case '?':   /* "\?" */
469			case 'x':   /* "\x" */
470			case 'a':   /* "\a" */
471			case '-':   /* "\-" */
472				continue;
473			}
474			if (!recursion--)
475				goto out;
476			switch (c) {
477			case '*':   /* "\*" */
478			case '@':   /* "\@" */
479			case '$':   /* "\$" */
480			case 'X':   /* "\X" */
481			case 'A':   /* "\A" */
482				continue;
483			case '{':   /* "/\{" */
484				if (string - 3 < start || *(string - 3) != '/')
485					goto out;
486				in_repetition = true;
487				continue;
488			case '}':   /* "\}/" */
489				if (*string != '/')
490					goto out;
491				if (!in_repetition)
492					goto out;
493				in_repetition = false;
494				continue;
495			}
496			goto out;
497		} else if (in_repetition && c == '/') {
498			goto out;
499		} else if (c <= ' ' || c >= 127) {
500			goto out;
501		}
502	}
503	if (in_repetition)
504		goto out;
505	return true;
506 out:
507	return false;
508}
509
510/**
511 * tomoyo_correct_word - Validate a string.
512 *
513 * @string: The string to check.
514 *
515 * Check whether the given string follows the naming rules.
516 * Returns true if @string follows the naming rules, false otherwise.
517 */
518bool tomoyo_correct_word(const char *string)
519{
520	return tomoyo_correct_word2(string, strlen(string));
521}
522
523/**
524 * tomoyo_correct_path2 - Check whether the given pathname follows the naming rules.
525 *
526 * @filename: The pathname to check.
527 * @len:      Length of @filename.
528 *
529 * Returns true if @filename follows the naming rules, false otherwise.
530 */
531static bool tomoyo_correct_path2(const char *filename, const size_t len)
532{
533	const char *cp1 = memchr(filename, '/', len);
534	const char *cp2 = memchr(filename, '.', len);
535
536	return cp1 && (!cp2 || (cp1 < cp2)) && tomoyo_correct_word2(filename, len);
537}
538
539/**
540 * tomoyo_correct_path - Validate a pathname.
541 *
542 * @filename: The pathname to check.
543 *
544 * Check whether the given pathname follows the naming rules.
545 * Returns true if @filename follows the naming rules, false otherwise.
546 */
547bool tomoyo_correct_path(const char *filename)
548{
549	return tomoyo_correct_path2(filename, strlen(filename));
550}
551
552/**
553 * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.
554 *
555 * @domainname: The domainname to check.
556 *
557 * Returns true if @domainname follows the naming rules, false otherwise.
558 */
559bool tomoyo_correct_domain(const unsigned char *domainname)
560{
561	if (!domainname || !tomoyo_domain_def(domainname))
562		return false;
563	domainname = strchr(domainname, ' ');
564	if (!domainname++)
565		return true;
566	while (1) {
567		const unsigned char *cp = strchr(domainname, ' ');
568
569		if (!cp)
570			break;
571		if (!tomoyo_correct_path2(domainname, cp - domainname))
572			return false;
573		domainname = cp + 1;
574	}
575	return tomoyo_correct_path(domainname);
576}
577
578/**
579 * tomoyo_domain_def - Check whether the given token can be a domainname.
580 *
581 * @buffer: The token to check.
582 *
583 * Returns true if @buffer possibly be a domainname, false otherwise.
584 */
585bool tomoyo_domain_def(const unsigned char *buffer)
586{
587	const unsigned char *cp;
588	int len;
589
590	if (*buffer != '<')
591		return false;
592	cp = strchr(buffer, ' ');
593	if (!cp)
594		len = strlen(buffer);
595	else
596		len = cp - buffer;
597	if (buffer[len - 1] != '>' ||
598	    !tomoyo_correct_word2(buffer + 1, len - 2))
599		return false;
600	return true;
601}
602
603/**
604 * tomoyo_find_domain - Find a domain by the given name.
605 *
606 * @domainname: The domainname to find.
607 *
608 * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
609 *
610 * Caller holds tomoyo_read_lock().
611 */
612struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
613{
614	struct tomoyo_domain_info *domain;
615	struct tomoyo_path_info name;
616
617	name.name = domainname;
618	tomoyo_fill_path_info(&name);
619	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list,
620				srcu_read_lock_held(&tomoyo_ss)) {
621		if (!domain->is_deleted &&
622		    !tomoyo_pathcmp(&name, domain->domainname))
623			return domain;
624	}
625	return NULL;
626}
627
628/**
629 * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
630 *
631 * @filename: The string to evaluate.
632 *
633 * Returns the initial length without a pattern in @filename.
634 */
635static int tomoyo_const_part_length(const char *filename)
636{
637	char c;
638	int len = 0;
639
640	if (!filename)
641		return 0;
642	while ((c = *filename++) != '\0') {
643		if (c != '\\') {
644			len++;
645			continue;
646		}
647		c = *filename++;
648		switch (c) {
649		case '\\':  /* "\\" */
650			len += 2;
651			continue;
652		case '0':   /* "\ooo" */
653		case '1':
654		case '2':
655		case '3':
656			c = *filename++;
657			if (c < '0' || c > '7')
658				break;
659			c = *filename++;
660			if (c < '0' || c > '7')
661				break;
662			len += 4;
663			continue;
664		}
665		break;
666	}
667	return len;
668}
669
670/**
671 * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
672 *
673 * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
674 *
675 * The caller sets "struct tomoyo_path_info"->name.
676 */
677void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
678{
679	const char *name = ptr->name;
680	const int len = strlen(name);
681
682	ptr->const_len = tomoyo_const_part_length(name);
683	ptr->is_dir = len && (name[len - 1] == '/');
684	ptr->is_patterned = (ptr->const_len < len);
685	ptr->hash = full_name_hash(NULL, name, len);
686}
687
688/**
689 * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
690 *
691 * @filename:     The start of string to check.
692 * @filename_end: The end of string to check.
693 * @pattern:      The start of pattern to compare.
694 * @pattern_end:  The end of pattern to compare.
695 *
696 * Returns true if @filename matches @pattern, false otherwise.
697 */
698static bool tomoyo_file_matches_pattern2(const char *filename,
699					 const char *filename_end,
700					 const char *pattern,
701					 const char *pattern_end)
702{
703	while (filename < filename_end && pattern < pattern_end) {
704		char c;
705		int i;
706		int j;
707
708		if (*pattern != '\\') {
709			if (*filename++ != *pattern++)
710				return false;
711			continue;
712		}
713		c = *filename;
714		pattern++;
715		switch (*pattern) {
716		case '?':
717			if (c == '/') {
718				return false;
719			} else if (c == '\\') {
720				if (filename[1] == '\\')
721					filename++;
722				else if (tomoyo_byte_range(filename + 1))
723					filename += 3;
724				else
725					return false;
726			}
727			break;
728		case '\\':
729			if (c != '\\')
730				return false;
731			if (*++filename != '\\')
732				return false;
733			break;
734		case '+':
735			if (!isdigit(c))
736				return false;
737			break;
738		case 'x':
739			if (!isxdigit(c))
740				return false;
741			break;
742		case 'a':
743			if (!tomoyo_alphabet_char(c))
744				return false;
745			break;
746		case '0':
747		case '1':
748		case '2':
749		case '3':
750			if (c == '\\' && tomoyo_byte_range(filename + 1)
751			    && strncmp(filename + 1, pattern, 3) == 0) {
752				filename += 3;
753				pattern += 2;
754				break;
755			}
756			return false; /* Not matched. */
757		case '*':
758		case '@':
759			for (i = 0; i <= filename_end - filename; i++) {
760				if (tomoyo_file_matches_pattern2(
761						    filename + i, filename_end,
762						    pattern + 1, pattern_end))
763					return true;
764				c = filename[i];
765				if (c == '.' && *pattern == '@')
766					break;
767				if (c != '\\')
768					continue;
769				if (filename[i + 1] == '\\')
770					i++;
771				else if (tomoyo_byte_range(filename + i + 1))
772					i += 3;
773				else
774					break; /* Bad pattern. */
775			}
776			return false; /* Not matched. */
777		default:
778			j = 0;
779			c = *pattern;
780			if (c == '$') {
781				while (isdigit(filename[j]))
782					j++;
783			} else if (c == 'X') {
784				while (isxdigit(filename[j]))
785					j++;
786			} else if (c == 'A') {
787				while (tomoyo_alphabet_char(filename[j]))
788					j++;
789			}
790			for (i = 1; i <= j; i++) {
791				if (tomoyo_file_matches_pattern2(
792						    filename + i, filename_end,
793						    pattern + 1, pattern_end))
794					return true;
795			}
796			return false; /* Not matched or bad pattern. */
797		}
798		filename++;
799		pattern++;
800	}
801	while (*pattern == '\\' &&
802	       (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
803		pattern += 2;
804	return filename == filename_end && pattern == pattern_end;
805}
806
807/**
808 * tomoyo_file_matches_pattern - Pattern matching without '/' character.
809 *
810 * @filename:     The start of string to check.
811 * @filename_end: The end of string to check.
812 * @pattern:      The start of pattern to compare.
813 * @pattern_end:  The end of pattern to compare.
814 *
815 * Returns true if @filename matches @pattern, false otherwise.
816 */
817static bool tomoyo_file_matches_pattern(const char *filename,
818					const char *filename_end,
819					const char *pattern,
820					const char *pattern_end)
821{
822	const char *pattern_start = pattern;
823	bool first = true;
824	bool result;
825
826	while (pattern < pattern_end - 1) {
827		/* Split at "\-" pattern. */
828		if (*pattern++ != '\\' || *pattern++ != '-')
829			continue;
830		result = tomoyo_file_matches_pattern2(filename,
831						      filename_end,
832						      pattern_start,
833						      pattern - 2);
834		if (first)
835			result = !result;
836		if (result)
837			return false;
838		first = false;
839		pattern_start = pattern;
840	}
841	result = tomoyo_file_matches_pattern2(filename, filename_end,
842					      pattern_start, pattern_end);
843	return first ? result : !result;
844}
845
846/**
847 * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
848 *
849 * @f: The start of string to check.
850 * @p: The start of pattern to compare.
851 *
852 * Returns true if @f matches @p, false otherwise.
853 */
854static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
855{
856	const char *f_delimiter;
857	const char *p_delimiter;
858
859	while (*f && *p) {
860		f_delimiter = strchr(f, '/');
861		if (!f_delimiter)
862			f_delimiter = f + strlen(f);
863		p_delimiter = strchr(p, '/');
864		if (!p_delimiter)
865			p_delimiter = p + strlen(p);
866		if (*p == '\\' && *(p + 1) == '{')
867			goto recursive;
868		if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
869						 p_delimiter))
870			return false;
871		f = f_delimiter;
872		if (*f)
873			f++;
874		p = p_delimiter;
875		if (*p)
876			p++;
877	}
878	/* Ignore trailing "\*" and "\@" in @pattern. */
879	while (*p == '\\' &&
880	       (*(p + 1) == '*' || *(p + 1) == '@'))
881		p += 2;
882	return !*f && !*p;
883 recursive:
884	/*
885	 * The "\{" pattern is permitted only after '/' character.
886	 * This guarantees that below "*(p - 1)" is safe.
887	 * Also, the "\}" pattern is permitted only before '/' character
888	 * so that "\{" + "\}" pair will not break the "\-" operator.
889	 */
890	if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
891	    *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
892		return false; /* Bad pattern. */
893	do {
894		/* Compare current component with pattern. */
895		if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
896						 p_delimiter - 2))
897			break;
898		/* Proceed to next component. */
899		f = f_delimiter;
900		if (!*f)
901			break;
902		f++;
903		/* Continue comparison. */
904		if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
905			return true;
906		f_delimiter = strchr(f, '/');
907	} while (f_delimiter);
908	return false; /* Not matched. */
909}
910
911/**
912 * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
913 *
914 * @filename: The filename to check.
915 * @pattern:  The pattern to compare.
916 *
917 * Returns true if matches, false otherwise.
918 *
919 * The following patterns are available.
920 *   \\     \ itself.
921 *   \ooo   Octal representation of a byte.
922 *   \*     Zero or more repetitions of characters other than '/'.
923 *   \@     Zero or more repetitions of characters other than '/' or '.'.
924 *   \?     1 byte character other than '/'.
925 *   \$     One or more repetitions of decimal digits.
926 *   \+     1 decimal digit.
927 *   \X     One or more repetitions of hexadecimal digits.
928 *   \x     1 hexadecimal digit.
929 *   \A     One or more repetitions of alphabet characters.
930 *   \a     1 alphabet character.
931 *
932 *   \-     Subtraction operator.
933 *
934 *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
935 *               /dir/dir/dir/ ).
936 */
937bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
938				 const struct tomoyo_path_info *pattern)
939{
940	const char *f = filename->name;
941	const char *p = pattern->name;
942	const int len = pattern->const_len;
943
944	/* If @pattern doesn't contain pattern, I can use strcmp(). */
945	if (!pattern->is_patterned)
946		return !tomoyo_pathcmp(filename, pattern);
947	/* Don't compare directory and non-directory. */
948	if (filename->is_dir != pattern->is_dir)
949		return false;
950	/* Compare the initial length without patterns. */
951	if (strncmp(f, p, len))
952		return false;
953	f += len;
954	p += len;
955	return tomoyo_path_matches_pattern2(f, p);
956}
957
958/**
959 * tomoyo_get_exe - Get tomoyo_realpath() of current process.
960 *
961 * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
962 *
963 * This function uses kzalloc(), so the caller must call kfree()
964 * if this function didn't return NULL.
965 */
966const char *tomoyo_get_exe(void)
967{
968	struct file *exe_file;
969	const char *cp;
970	struct mm_struct *mm = current->mm;
971
972	if (!mm)
973		return NULL;
974	exe_file = get_mm_exe_file(mm);
975	if (!exe_file)
976		return NULL;
977
978	cp = tomoyo_realpath_from_path(&exe_file->f_path);
979	fput(exe_file);
980	return cp;
981}
982
983/**
984 * tomoyo_get_mode - Get MAC mode.
985 *
986 * @ns:      Pointer to "struct tomoyo_policy_namespace".
987 * @profile: Profile number.
988 * @index:   Index number of functionality.
989 *
990 * Returns mode.
991 */
992int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
993		    const u8 index)
994{
995	u8 mode;
996	struct tomoyo_profile *p;
997
998	if (!tomoyo_policy_loaded)
999		return TOMOYO_CONFIG_DISABLED;
1000	p = tomoyo_profile(ns, profile);
1001	mode = p->config[index];
1002	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
1003		mode = p->config[tomoyo_index2category[index]
1004				 + TOMOYO_MAX_MAC_INDEX];
1005	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
1006		mode = p->default_config;
1007	return mode & 3;
1008}
1009
1010/**
1011 * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
1012 *
1013 * @r:      Pointer to "struct tomoyo_request_info" to initialize.
1014 * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
1015 * @index:  Index number of functionality.
1016 *
1017 * Returns mode.
1018 */
1019int tomoyo_init_request_info(struct tomoyo_request_info *r,
1020			     struct tomoyo_domain_info *domain, const u8 index)
1021{
1022	u8 profile;
1023
1024	memset(r, 0, sizeof(*r));
1025	if (!domain)
1026		domain = tomoyo_domain();
1027	r->domain = domain;
1028	profile = domain->profile;
1029	r->profile = profile;
1030	r->type = index;
1031	r->mode = tomoyo_get_mode(domain->ns, profile, index);
1032	return r->mode;
1033}
1034
1035/**
1036 * tomoyo_domain_quota_is_ok - Check for domain's quota.
1037 *
1038 * @r: Pointer to "struct tomoyo_request_info".
1039 *
1040 * Returns true if the domain is not exceeded quota, false otherwise.
1041 *
1042 * Caller holds tomoyo_read_lock().
1043 */
1044bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
1045{
1046	unsigned int count = 0;
1047	struct tomoyo_domain_info *domain = r->domain;
1048	struct tomoyo_acl_info *ptr;
1049
1050	if (r->mode != TOMOYO_CONFIG_LEARNING)
1051		return false;
1052	if (!domain)
1053		return true;
1054	if (READ_ONCE(domain->flags[TOMOYO_DIF_QUOTA_WARNED]))
1055		return false;
1056	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list,
1057				srcu_read_lock_held(&tomoyo_ss)) {
1058		u16 perm;
1059
1060		if (ptr->is_deleted)
1061			continue;
1062		/*
1063		 * Reading perm bitmap might race with tomoyo_merge_*() because
1064		 * caller does not hold tomoyo_policy_lock mutex. But exceeding
1065		 * max_learning_entry parameter by a few entries does not harm.
1066		 */
1067		switch (ptr->type) {
1068		case TOMOYO_TYPE_PATH_ACL:
1069			perm = data_race(container_of(ptr, struct tomoyo_path_acl, head)->perm);
1070			break;
1071		case TOMOYO_TYPE_PATH2_ACL:
1072			perm = data_race(container_of(ptr, struct tomoyo_path2_acl, head)->perm);
1073			break;
1074		case TOMOYO_TYPE_PATH_NUMBER_ACL:
1075			perm = data_race(container_of(ptr, struct tomoyo_path_number_acl, head)
1076				  ->perm);
1077			break;
1078		case TOMOYO_TYPE_MKDEV_ACL:
1079			perm = data_race(container_of(ptr, struct tomoyo_mkdev_acl, head)->perm);
1080			break;
1081		case TOMOYO_TYPE_INET_ACL:
1082			perm = data_race(container_of(ptr, struct tomoyo_inet_acl, head)->perm);
1083			break;
1084		case TOMOYO_TYPE_UNIX_ACL:
1085			perm = data_race(container_of(ptr, struct tomoyo_unix_acl, head)->perm);
1086			break;
1087		case TOMOYO_TYPE_MANUAL_TASK_ACL:
1088			perm = 0;
1089			break;
1090		default:
1091			perm = 1;
1092		}
1093		count += hweight16(perm);
1094	}
1095	if (count < tomoyo_profile(domain->ns, domain->profile)->
1096	    pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
1097		return true;
1098	WRITE_ONCE(domain->flags[TOMOYO_DIF_QUOTA_WARNED], true);
1099	/* r->granted = false; */
1100	tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
1101#ifndef CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING
1102	pr_warn("WARNING: Domain '%s' has too many ACLs to hold. Stopped learning mode.\n",
1103		domain->domainname->name);
1104#endif
1105	return false;
1106}
1107