xref: /kernel/linux/linux-5.10/security/tomoyo/util.c (revision 8c2ecf20) 
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 * @time:  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	const char *const start = string;
438	bool in_repetition = false;
439	unsigned char c;
440	unsigned char d;
441	unsigned char e;
442
443	if (!len)
444		goto out;
445	while (len--) {
446		c = *string++;
447		if (c == '\\') {
448			if (!len--)
449				goto out;
450			c = *string++;
451			switch (c) {
452			case '\\':  /* "\\" */
453				continue;
454			case '$':   /* "\$" */
455			case '+':   /* "\+" */
456			case '?':   /* "\?" */
457			case '*':   /* "\*" */
458			case '@':   /* "\@" */
459			case 'x':   /* "\x" */
460			case 'X':   /* "\X" */
461			case 'a':   /* "\a" */
462			case 'A':   /* "\A" */
463			case '-':   /* "\-" */
464				continue;
465			case '{':   /* "/\{" */
466				if (string - 3 < start || *(string - 3) != '/')
467					break;
468				in_repetition = true;
469				continue;
470			case '}':   /* "\}/" */
471				if (*string != '/')
472					break;
473				if (!in_repetition)
474					break;
475				in_repetition = false;
476				continue;
477			case '0':   /* "\ooo" */
478			case '1':
479			case '2':
480			case '3':
481				if (!len-- || !len--)
482					break;
483				d = *string++;
484				e = *string++;
485				if (d < '0' || d > '7' || e < '0' || e > '7')
486					break;
487				c = tomoyo_make_byte(c, d, e);
488				if (c <= ' ' || c >= 127)
489					continue;
490			}
491			goto out;
492		} else if (in_repetition && c == '/') {
493			goto out;
494		} else if (c <= ' ' || c >= 127) {
495			goto out;
496		}
497	}
498	if (in_repetition)
499		goto out;
500	return true;
501 out:
502	return false;
503}
504
505/**
506 * tomoyo_correct_word - Validate a string.
507 *
508 * @string: The string to check.
509 *
510 * Check whether the given string follows the naming rules.
511 * Returns true if @string follows the naming rules, false otherwise.
512 */
513bool tomoyo_correct_word(const char *string)
514{
515	return tomoyo_correct_word2(string, strlen(string));
516}
517
518/**
519 * tomoyo_correct_path2 - Check whether the given pathname follows the naming rules.
520 *
521 * @filename: The pathname to check.
522 * @len:      Length of @filename.
523 *
524 * Returns true if @filename follows the naming rules, false otherwise.
525 */
526static bool tomoyo_correct_path2(const char *filename, const size_t len)
527{
528	const char *cp1 = memchr(filename, '/', len);
529	const char *cp2 = memchr(filename, '.', len);
530
531	return cp1 && (!cp2 || (cp1 < cp2)) && tomoyo_correct_word2(filename, len);
532}
533
534/**
535 * tomoyo_correct_path - Validate a pathname.
536 *
537 * @filename: The pathname to check.
538 *
539 * Check whether the given pathname follows the naming rules.
540 * Returns true if @filename follows the naming rules, false otherwise.
541 */
542bool tomoyo_correct_path(const char *filename)
543{
544	return tomoyo_correct_path2(filename, strlen(filename));
545}
546
547/**
548 * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.
549 *
550 * @domainname: The domainname to check.
551 *
552 * Returns true if @domainname follows the naming rules, false otherwise.
553 */
554bool tomoyo_correct_domain(const unsigned char *domainname)
555{
556	if (!domainname || !tomoyo_domain_def(domainname))
557		return false;
558	domainname = strchr(domainname, ' ');
559	if (!domainname++)
560		return true;
561	while (1) {
562		const unsigned char *cp = strchr(domainname, ' ');
563
564		if (!cp)
565			break;
566		if (!tomoyo_correct_path2(domainname, cp - domainname))
567			return false;
568		domainname = cp + 1;
569	}
570	return tomoyo_correct_path(domainname);
571}
572
573/**
574 * tomoyo_domain_def - Check whether the given token can be a domainname.
575 *
576 * @buffer: The token to check.
577 *
578 * Returns true if @buffer possibly be a domainname, false otherwise.
579 */
580bool tomoyo_domain_def(const unsigned char *buffer)
581{
582	const unsigned char *cp;
583	int len;
584
585	if (*buffer != '<')
586		return false;
587	cp = strchr(buffer, ' ');
588	if (!cp)
589		len = strlen(buffer);
590	else
591		len = cp - buffer;
592	if (buffer[len - 1] != '>' ||
593	    !tomoyo_correct_word2(buffer + 1, len - 2))
594		return false;
595	return true;
596}
597
598/**
599 * tomoyo_find_domain - Find a domain by the given name.
600 *
601 * @domainname: The domainname to find.
602 *
603 * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
604 *
605 * Caller holds tomoyo_read_lock().
606 */
607struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
608{
609	struct tomoyo_domain_info *domain;
610	struct tomoyo_path_info name;
611
612	name.name = domainname;
613	tomoyo_fill_path_info(&name);
614	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list,
615				srcu_read_lock_held(&tomoyo_ss)) {
616		if (!domain->is_deleted &&
617		    !tomoyo_pathcmp(&name, domain->domainname))
618			return domain;
619	}
620	return NULL;
621}
622
623/**
624 * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
625 *
626 * @filename: The string to evaluate.
627 *
628 * Returns the initial length without a pattern in @filename.
629 */
630static int tomoyo_const_part_length(const char *filename)
631{
632	char c;
633	int len = 0;
634
635	if (!filename)
636		return 0;
637	while ((c = *filename++) != '\0') {
638		if (c != '\\') {
639			len++;
640			continue;
641		}
642		c = *filename++;
643		switch (c) {
644		case '\\':  /* "\\" */
645			len += 2;
646			continue;
647		case '0':   /* "\ooo" */
648		case '1':
649		case '2':
650		case '3':
651			c = *filename++;
652			if (c < '0' || c > '7')
653				break;
654			c = *filename++;
655			if (c < '0' || c > '7')
656				break;
657			len += 4;
658			continue;
659		}
660		break;
661	}
662	return len;
663}
664
665/**
666 * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
667 *
668 * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
669 *
670 * The caller sets "struct tomoyo_path_info"->name.
671 */
672void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
673{
674	const char *name = ptr->name;
675	const int len = strlen(name);
676
677	ptr->const_len = tomoyo_const_part_length(name);
678	ptr->is_dir = len && (name[len - 1] == '/');
679	ptr->is_patterned = (ptr->const_len < len);
680	ptr->hash = full_name_hash(NULL, name, len);
681}
682
683/**
684 * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
685 *
686 * @filename:     The start of string to check.
687 * @filename_end: The end of string to check.
688 * @pattern:      The start of pattern to compare.
689 * @pattern_end:  The end of pattern to compare.
690 *
691 * Returns true if @filename matches @pattern, false otherwise.
692 */
693static bool tomoyo_file_matches_pattern2(const char *filename,
694					 const char *filename_end,
695					 const char *pattern,
696					 const char *pattern_end)
697{
698	while (filename < filename_end && pattern < pattern_end) {
699		char c;
700		int i;
701		int j;
702
703		if (*pattern != '\\') {
704			if (*filename++ != *pattern++)
705				return false;
706			continue;
707		}
708		c = *filename;
709		pattern++;
710		switch (*pattern) {
711		case '?':
712			if (c == '/') {
713				return false;
714			} else if (c == '\\') {
715				if (filename[1] == '\\')
716					filename++;
717				else if (tomoyo_byte_range(filename + 1))
718					filename += 3;
719				else
720					return false;
721			}
722			break;
723		case '\\':
724			if (c != '\\')
725				return false;
726			if (*++filename != '\\')
727				return false;
728			break;
729		case '+':
730			if (!isdigit(c))
731				return false;
732			break;
733		case 'x':
734			if (!isxdigit(c))
735				return false;
736			break;
737		case 'a':
738			if (!tomoyo_alphabet_char(c))
739				return false;
740			break;
741		case '0':
742		case '1':
743		case '2':
744		case '3':
745			if (c == '\\' && tomoyo_byte_range(filename + 1)
746			    && strncmp(filename + 1, pattern, 3) == 0) {
747				filename += 3;
748				pattern += 2;
749				break;
750			}
751			return false; /* Not matched. */
752		case '*':
753		case '@':
754			for (i = 0; i <= filename_end - filename; i++) {
755				if (tomoyo_file_matches_pattern2(
756						    filename + i, filename_end,
757						    pattern + 1, pattern_end))
758					return true;
759				c = filename[i];
760				if (c == '.' && *pattern == '@')
761					break;
762				if (c != '\\')
763					continue;
764				if (filename[i + 1] == '\\')
765					i++;
766				else if (tomoyo_byte_range(filename + i + 1))
767					i += 3;
768				else
769					break; /* Bad pattern. */
770			}
771			return false; /* Not matched. */
772		default:
773			j = 0;
774			c = *pattern;
775			if (c == '$') {
776				while (isdigit(filename[j]))
777					j++;
778			} else if (c == 'X') {
779				while (isxdigit(filename[j]))
780					j++;
781			} else if (c == 'A') {
782				while (tomoyo_alphabet_char(filename[j]))
783					j++;
784			}
785			for (i = 1; i <= j; i++) {
786				if (tomoyo_file_matches_pattern2(
787						    filename + i, filename_end,
788						    pattern + 1, pattern_end))
789					return true;
790			}
791			return false; /* Not matched or bad pattern. */
792		}
793		filename++;
794		pattern++;
795	}
796	while (*pattern == '\\' &&
797	       (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
798		pattern += 2;
799	return filename == filename_end && pattern == pattern_end;
800}
801
802/**
803 * tomoyo_file_matches_pattern - Pattern matching without '/' character.
804 *
805 * @filename:     The start of string to check.
806 * @filename_end: The end of string to check.
807 * @pattern:      The start of pattern to compare.
808 * @pattern_end:  The end of pattern to compare.
809 *
810 * Returns true if @filename matches @pattern, false otherwise.
811 */
812static bool tomoyo_file_matches_pattern(const char *filename,
813					const char *filename_end,
814					const char *pattern,
815					const char *pattern_end)
816{
817	const char *pattern_start = pattern;
818	bool first = true;
819	bool result;
820
821	while (pattern < pattern_end - 1) {
822		/* Split at "\-" pattern. */
823		if (*pattern++ != '\\' || *pattern++ != '-')
824			continue;
825		result = tomoyo_file_matches_pattern2(filename,
826						      filename_end,
827						      pattern_start,
828						      pattern - 2);
829		if (first)
830			result = !result;
831		if (result)
832			return false;
833		first = false;
834		pattern_start = pattern;
835	}
836	result = tomoyo_file_matches_pattern2(filename, filename_end,
837					      pattern_start, pattern_end);
838	return first ? result : !result;
839}
840
841/**
842 * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
843 *
844 * @f: The start of string to check.
845 * @p: The start of pattern to compare.
846 *
847 * Returns true if @f matches @p, false otherwise.
848 */
849static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
850{
851	const char *f_delimiter;
852	const char *p_delimiter;
853
854	while (*f && *p) {
855		f_delimiter = strchr(f, '/');
856		if (!f_delimiter)
857			f_delimiter = f + strlen(f);
858		p_delimiter = strchr(p, '/');
859		if (!p_delimiter)
860			p_delimiter = p + strlen(p);
861		if (*p == '\\' && *(p + 1) == '{')
862			goto recursive;
863		if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
864						 p_delimiter))
865			return false;
866		f = f_delimiter;
867		if (*f)
868			f++;
869		p = p_delimiter;
870		if (*p)
871			p++;
872	}
873	/* Ignore trailing "\*" and "\@" in @pattern. */
874	while (*p == '\\' &&
875	       (*(p + 1) == '*' || *(p + 1) == '@'))
876		p += 2;
877	return !*f && !*p;
878 recursive:
879	/*
880	 * The "\{" pattern is permitted only after '/' character.
881	 * This guarantees that below "*(p - 1)" is safe.
882	 * Also, the "\}" pattern is permitted only before '/' character
883	 * so that "\{" + "\}" pair will not break the "\-" operator.
884	 */
885	if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
886	    *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
887		return false; /* Bad pattern. */
888	do {
889		/* Compare current component with pattern. */
890		if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
891						 p_delimiter - 2))
892			break;
893		/* Proceed to next component. */
894		f = f_delimiter;
895		if (!*f)
896			break;
897		f++;
898		/* Continue comparison. */
899		if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
900			return true;
901		f_delimiter = strchr(f, '/');
902	} while (f_delimiter);
903	return false; /* Not matched. */
904}
905
906/**
907 * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
908 *
909 * @filename: The filename to check.
910 * @pattern:  The pattern to compare.
911 *
912 * Returns true if matches, false otherwise.
913 *
914 * The following patterns are available.
915 *   \\     \ itself.
916 *   \ooo   Octal representation of a byte.
917 *   \*     Zero or more repetitions of characters other than '/'.
918 *   \@     Zero or more repetitions of characters other than '/' or '.'.
919 *   \?     1 byte character other than '/'.
920 *   \$     One or more repetitions of decimal digits.
921 *   \+     1 decimal digit.
922 *   \X     One or more repetitions of hexadecimal digits.
923 *   \x     1 hexadecimal digit.
924 *   \A     One or more repetitions of alphabet characters.
925 *   \a     1 alphabet character.
926 *
927 *   \-     Subtraction operator.
928 *
929 *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
930 *               /dir/dir/dir/ ).
931 */
932bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
933				 const struct tomoyo_path_info *pattern)
934{
935	const char *f = filename->name;
936	const char *p = pattern->name;
937	const int len = pattern->const_len;
938
939	/* If @pattern doesn't contain pattern, I can use strcmp(). */
940	if (!pattern->is_patterned)
941		return !tomoyo_pathcmp(filename, pattern);
942	/* Don't compare directory and non-directory. */
943	if (filename->is_dir != pattern->is_dir)
944		return false;
945	/* Compare the initial length without patterns. */
946	if (strncmp(f, p, len))
947		return false;
948	f += len;
949	p += len;
950	return tomoyo_path_matches_pattern2(f, p);
951}
952
953/**
954 * tomoyo_get_exe - Get tomoyo_realpath() of current process.
955 *
956 * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
957 *
958 * This function uses kzalloc(), so the caller must call kfree()
959 * if this function didn't return NULL.
960 */
961const char *tomoyo_get_exe(void)
962{
963	struct file *exe_file;
964	const char *cp;
965	struct mm_struct *mm = current->mm;
966
967	if (!mm)
968		return NULL;
969	exe_file = get_mm_exe_file(mm);
970	if (!exe_file)
971		return NULL;
972
973	cp = tomoyo_realpath_from_path(&exe_file->f_path);
974	fput(exe_file);
975	return cp;
976}
977
978/**
979 * tomoyo_get_mode - Get MAC mode.
980 *
981 * @ns:      Pointer to "struct tomoyo_policy_namespace".
982 * @profile: Profile number.
983 * @index:   Index number of functionality.
984 *
985 * Returns mode.
986 */
987int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
988		    const u8 index)
989{
990	u8 mode;
991	struct tomoyo_profile *p;
992
993	if (!tomoyo_policy_loaded)
994		return TOMOYO_CONFIG_DISABLED;
995	p = tomoyo_profile(ns, profile);
996	mode = p->config[index];
997	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
998		mode = p->config[tomoyo_index2category[index]
999				 + TOMOYO_MAX_MAC_INDEX];
1000	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
1001		mode = p->default_config;
1002	return mode & 3;
1003}
1004
1005/**
1006 * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
1007 *
1008 * @r:      Pointer to "struct tomoyo_request_info" to initialize.
1009 * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
1010 * @index:  Index number of functionality.
1011 *
1012 * Returns mode.
1013 */
1014int tomoyo_init_request_info(struct tomoyo_request_info *r,
1015			     struct tomoyo_domain_info *domain, const u8 index)
1016{
1017	u8 profile;
1018
1019	memset(r, 0, sizeof(*r));
1020	if (!domain)
1021		domain = tomoyo_domain();
1022	r->domain = domain;
1023	profile = domain->profile;
1024	r->profile = profile;
1025	r->type = index;
1026	r->mode = tomoyo_get_mode(domain->ns, profile, index);
1027	return r->mode;
1028}
1029
1030/**
1031 * tomoyo_domain_quota_is_ok - Check for domain's quota.
1032 *
1033 * @r: Pointer to "struct tomoyo_request_info".
1034 *
1035 * Returns true if the domain is not exceeded quota, false otherwise.
1036 *
1037 * Caller holds tomoyo_read_lock().
1038 */
1039bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
1040{
1041	unsigned int count = 0;
1042	struct tomoyo_domain_info *domain = r->domain;
1043	struct tomoyo_acl_info *ptr;
1044
1045	if (r->mode != TOMOYO_CONFIG_LEARNING)
1046		return false;
1047	if (!domain)
1048		return true;
1049	if (READ_ONCE(domain->flags[TOMOYO_DIF_QUOTA_WARNED]))
1050		return false;
1051	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list,
1052				srcu_read_lock_held(&tomoyo_ss)) {
1053		u16 perm;
1054
1055		if (ptr->is_deleted)
1056			continue;
1057		/*
1058		 * Reading perm bitmap might race with tomoyo_merge_*() because
1059		 * caller does not hold tomoyo_policy_lock mutex. But exceeding
1060		 * max_learning_entry parameter by a few entries does not harm.
1061		 */
1062		switch (ptr->type) {
1063		case TOMOYO_TYPE_PATH_ACL:
1064			perm = data_race(container_of(ptr, struct tomoyo_path_acl, head)->perm);
1065			break;
1066		case TOMOYO_TYPE_PATH2_ACL:
1067			perm = data_race(container_of(ptr, struct tomoyo_path2_acl, head)->perm);
1068			break;
1069		case TOMOYO_TYPE_PATH_NUMBER_ACL:
1070			perm = data_race(container_of(ptr, struct tomoyo_path_number_acl, head)
1071				  ->perm);
1072			break;
1073		case TOMOYO_TYPE_MKDEV_ACL:
1074			perm = data_race(container_of(ptr, struct tomoyo_mkdev_acl, head)->perm);
1075			break;
1076		case TOMOYO_TYPE_INET_ACL:
1077			perm = data_race(container_of(ptr, struct tomoyo_inet_acl, head)->perm);
1078			break;
1079		case TOMOYO_TYPE_UNIX_ACL:
1080			perm = data_race(container_of(ptr, struct tomoyo_unix_acl, head)->perm);
1081			break;
1082		case TOMOYO_TYPE_MANUAL_TASK_ACL:
1083			perm = 0;
1084			break;
1085		default:
1086			perm = 1;
1087		}
1088		count += hweight16(perm);
1089	}
1090	if (count < tomoyo_profile(domain->ns, domain->profile)->
1091	    pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
1092		return true;
1093	WRITE_ONCE(domain->flags[TOMOYO_DIF_QUOTA_WARNED], true);
1094	/* r->granted = false; */
1095	tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
1096#ifndef CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING
1097	pr_warn("WARNING: Domain '%s' has too many ACLs to hold. Stopped learning mode.\n",
1098		domain->domainname->name);
1099#endif
1100	return false;
1101}
1102