1/*
2 * security/tomoyo/util.c
3 *
4 * Copyright (C) 2005-2011  NTT DATA CORPORATION
5 */
6
7#include <linux/slab.h>
8#include "common.h"
9
10/* Lock for protecting policy. */
11DEFINE_MUTEX(tomoyo_policy_lock);
12
13/* Has /sbin/init started? */
14bool tomoyo_policy_loaded;
15
16/*
17 * Mapping table from "enum tomoyo_mac_index" to
18 * "enum tomoyo_mac_category_index".
19 */
20const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = {
21	/* CONFIG::file group */
22	[TOMOYO_MAC_FILE_EXECUTE]    = TOMOYO_MAC_CATEGORY_FILE,
23	[TOMOYO_MAC_FILE_OPEN]       = TOMOYO_MAC_CATEGORY_FILE,
24	[TOMOYO_MAC_FILE_CREATE]     = TOMOYO_MAC_CATEGORY_FILE,
25	[TOMOYO_MAC_FILE_UNLINK]     = TOMOYO_MAC_CATEGORY_FILE,
26	[TOMOYO_MAC_FILE_GETATTR]    = TOMOYO_MAC_CATEGORY_FILE,
27	[TOMOYO_MAC_FILE_MKDIR]      = TOMOYO_MAC_CATEGORY_FILE,
28	[TOMOYO_MAC_FILE_RMDIR]      = TOMOYO_MAC_CATEGORY_FILE,
29	[TOMOYO_MAC_FILE_MKFIFO]     = TOMOYO_MAC_CATEGORY_FILE,
30	[TOMOYO_MAC_FILE_MKSOCK]     = TOMOYO_MAC_CATEGORY_FILE,
31	[TOMOYO_MAC_FILE_TRUNCATE]   = TOMOYO_MAC_CATEGORY_FILE,
32	[TOMOYO_MAC_FILE_SYMLINK]    = TOMOYO_MAC_CATEGORY_FILE,
33	[TOMOYO_MAC_FILE_MKBLOCK]    = TOMOYO_MAC_CATEGORY_FILE,
34	[TOMOYO_MAC_FILE_MKCHAR]     = TOMOYO_MAC_CATEGORY_FILE,
35	[TOMOYO_MAC_FILE_LINK]       = TOMOYO_MAC_CATEGORY_FILE,
36	[TOMOYO_MAC_FILE_RENAME]     = TOMOYO_MAC_CATEGORY_FILE,
37	[TOMOYO_MAC_FILE_CHMOD]      = TOMOYO_MAC_CATEGORY_FILE,
38	[TOMOYO_MAC_FILE_CHOWN]      = TOMOYO_MAC_CATEGORY_FILE,
39	[TOMOYO_MAC_FILE_CHGRP]      = TOMOYO_MAC_CATEGORY_FILE,
40	[TOMOYO_MAC_FILE_IOCTL]      = TOMOYO_MAC_CATEGORY_FILE,
41	[TOMOYO_MAC_FILE_CHROOT]     = TOMOYO_MAC_CATEGORY_FILE,
42	[TOMOYO_MAC_FILE_MOUNT]      = TOMOYO_MAC_CATEGORY_FILE,
43	[TOMOYO_MAC_FILE_UMOUNT]     = TOMOYO_MAC_CATEGORY_FILE,
44	[TOMOYO_MAC_FILE_PIVOT_ROOT] = TOMOYO_MAC_CATEGORY_FILE,
45	/* CONFIG::network group */
46	[TOMOYO_MAC_NETWORK_INET_STREAM_BIND]       =
47	TOMOYO_MAC_CATEGORY_NETWORK,
48	[TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN]     =
49	TOMOYO_MAC_CATEGORY_NETWORK,
50	[TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT]    =
51	TOMOYO_MAC_CATEGORY_NETWORK,
52	[TOMOYO_MAC_NETWORK_INET_DGRAM_BIND]        =
53	TOMOYO_MAC_CATEGORY_NETWORK,
54	[TOMOYO_MAC_NETWORK_INET_DGRAM_SEND]        =
55	TOMOYO_MAC_CATEGORY_NETWORK,
56	[TOMOYO_MAC_NETWORK_INET_RAW_BIND]          =
57	TOMOYO_MAC_CATEGORY_NETWORK,
58	[TOMOYO_MAC_NETWORK_INET_RAW_SEND]          =
59	TOMOYO_MAC_CATEGORY_NETWORK,
60	[TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND]       =
61	TOMOYO_MAC_CATEGORY_NETWORK,
62	[TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN]     =
63	TOMOYO_MAC_CATEGORY_NETWORK,
64	[TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT]    =
65	TOMOYO_MAC_CATEGORY_NETWORK,
66	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND]        =
67	TOMOYO_MAC_CATEGORY_NETWORK,
68	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND]        =
69	TOMOYO_MAC_CATEGORY_NETWORK,
70	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND]    =
71	TOMOYO_MAC_CATEGORY_NETWORK,
72	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN]  =
73	TOMOYO_MAC_CATEGORY_NETWORK,
74	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT] =
75	TOMOYO_MAC_CATEGORY_NETWORK,
76	/* CONFIG::misc group */
77	[TOMOYO_MAC_ENVIRON]         = TOMOYO_MAC_CATEGORY_MISC,
78};
79
80/**
81 * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
82 *
83 * @time:  Seconds since 1970/01/01 00:00:00.
84 * @stamp: Pointer to "struct tomoyo_time".
85 *
86 * Returns nothing.
87 *
88 * This function does not handle Y2038 problem.
89 */
90void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
91{
92	static const u16 tomoyo_eom[2][12] = {
93		{ 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
94		{ 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
95	};
96	u16 y;
97	u8 m;
98	bool r;
99	stamp->sec = time % 60;
100	time /= 60;
101	stamp->min = time % 60;
102	time /= 60;
103	stamp->hour = time % 24;
104	time /= 24;
105	for (y = 1970; ; y++) {
106		const unsigned short days = (y & 3) ? 365 : 366;
107		if (time < days)
108			break;
109		time -= days;
110	}
111	r = (y & 3) == 0;
112	for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
113		;
114	if (m)
115		time -= tomoyo_eom[r][m - 1];
116	stamp->year = y;
117	stamp->month = ++m;
118	stamp->day = ++time;
119}
120
121/**
122 * tomoyo_permstr - Find permission keywords.
123 *
124 * @string: String representation for permissions in foo/bar/buz format.
125 * @keyword: Keyword to find from @string/
126 *
127 * Returns ture if @keyword was found in @string, false otherwise.
128 *
129 * This function assumes that strncmp(w1, w2, strlen(w1)) != 0 if w1 != w2.
130 */
131bool tomoyo_permstr(const char *string, const char *keyword)
132{
133	const char *cp = strstr(string, keyword);
134	if (cp)
135		return cp == string || *(cp - 1) == '/';
136	return false;
137}
138
139/**
140 * tomoyo_read_token - Read a word from a line.
141 *
142 * @param: Pointer to "struct tomoyo_acl_param".
143 *
144 * Returns a word on success, "" otherwise.
145 *
146 * To allow the caller to skip NULL check, this function returns "" rather than
147 * NULL if there is no more words to read.
148 */
149char *tomoyo_read_token(struct tomoyo_acl_param *param)
150{
151	char *pos = param->data;
152	char *del = strchr(pos, ' ');
153	if (del)
154		*del++ = '\0';
155	else
156		del = pos + strlen(pos);
157	param->data = del;
158	return pos;
159}
160
161/**
162 * tomoyo_get_domainname - Read a domainname from a line.
163 *
164 * @param: Pointer to "struct tomoyo_acl_param".
165 *
166 * Returns a domainname on success, NULL otherwise.
167 */
168const struct tomoyo_path_info *tomoyo_get_domainname
169(struct tomoyo_acl_param *param)
170{
171	char *start = param->data;
172	char *pos = start;
173	while (*pos) {
174		if (*pos++ != ' ' || *pos++ == '/')
175			continue;
176		pos -= 2;
177		*pos++ = '\0';
178		break;
179	}
180	param->data = pos;
181	if (tomoyo_correct_domain(start))
182		return tomoyo_get_name(start);
183	return NULL;
184}
185
186/**
187 * tomoyo_parse_ulong - Parse an "unsigned long" value.
188 *
189 * @result: Pointer to "unsigned long".
190 * @str:    Pointer to string to parse.
191 *
192 * Returns one of values in "enum tomoyo_value_type".
193 *
194 * The @src is updated to point the first character after the value
195 * on success.
196 */
197u8 tomoyo_parse_ulong(unsigned long *result, char **str)
198{
199	const char *cp = *str;
200	char *ep;
201	int base = 10;
202	if (*cp == '0') {
203		char c = *(cp + 1);
204		if (c == 'x' || c == 'X') {
205			base = 16;
206			cp += 2;
207		} else if (c >= '0' && c <= '7') {
208			base = 8;
209			cp++;
210		}
211	}
212	*result = simple_strtoul(cp, &ep, base);
213	if (cp == ep)
214		return TOMOYO_VALUE_TYPE_INVALID;
215	*str = ep;
216	switch (base) {
217	case 16:
218		return TOMOYO_VALUE_TYPE_HEXADECIMAL;
219	case 8:
220		return TOMOYO_VALUE_TYPE_OCTAL;
221	default:
222		return TOMOYO_VALUE_TYPE_DECIMAL;
223	}
224}
225
226/**
227 * tomoyo_print_ulong - Print an "unsigned long" value.
228 *
229 * @buffer:     Pointer to buffer.
230 * @buffer_len: Size of @buffer.
231 * @value:      An "unsigned long" value.
232 * @type:       Type of @value.
233 *
234 * Returns nothing.
235 */
236void tomoyo_print_ulong(char *buffer, const int buffer_len,
237			const unsigned long value, const u8 type)
238{
239	if (type == TOMOYO_VALUE_TYPE_DECIMAL)
240		snprintf(buffer, buffer_len, "%lu", value);
241	else if (type == TOMOYO_VALUE_TYPE_OCTAL)
242		snprintf(buffer, buffer_len, "0%lo", value);
243	else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL)
244		snprintf(buffer, buffer_len, "0x%lX", value);
245	else
246		snprintf(buffer, buffer_len, "type(%u)", type);
247}
248
249/**
250 * tomoyo_parse_name_union - Parse a tomoyo_name_union.
251 *
252 * @param: Pointer to "struct tomoyo_acl_param".
253 * @ptr:   Pointer to "struct tomoyo_name_union".
254 *
255 * Returns true on success, false otherwise.
256 */
257bool tomoyo_parse_name_union(struct tomoyo_acl_param *param,
258			     struct tomoyo_name_union *ptr)
259{
260	char *filename;
261	if (param->data[0] == '@') {
262		param->data++;
263		ptr->group = tomoyo_get_group(param, TOMOYO_PATH_GROUP);
264		return ptr->group != NULL;
265	}
266	filename = tomoyo_read_token(param);
267	if (!tomoyo_correct_word(filename))
268		return false;
269	ptr->filename = tomoyo_get_name(filename);
270	return ptr->filename != NULL;
271}
272
273/**
274 * tomoyo_parse_number_union - Parse a tomoyo_number_union.
275 *
276 * @param: Pointer to "struct tomoyo_acl_param".
277 * @ptr:   Pointer to "struct tomoyo_number_union".
278 *
279 * Returns true on success, false otherwise.
280 */
281bool tomoyo_parse_number_union(struct tomoyo_acl_param *param,
282			       struct tomoyo_number_union *ptr)
283{
284	char *data;
285	u8 type;
286	unsigned long v;
287	memset(ptr, 0, sizeof(*ptr));
288	if (param->data[0] == '@') {
289		param->data++;
290		ptr->group = tomoyo_get_group(param, TOMOYO_NUMBER_GROUP);
291		return ptr->group != NULL;
292	}
293	data = tomoyo_read_token(param);
294	type = tomoyo_parse_ulong(&v, &data);
295	if (type == TOMOYO_VALUE_TYPE_INVALID)
296		return false;
297	ptr->values[0] = v;
298	ptr->value_type[0] = type;
299	if (!*data) {
300		ptr->values[1] = v;
301		ptr->value_type[1] = type;
302		return true;
303	}
304	if (*data++ != '-')
305		return false;
306	type = tomoyo_parse_ulong(&v, &data);
307	if (type == TOMOYO_VALUE_TYPE_INVALID || *data || ptr->values[0] > v)
308		return false;
309	ptr->values[1] = v;
310	ptr->value_type[1] = type;
311	return true;
312}
313
314/**
315 * tomoyo_byte_range - Check whether the string is a \ooo style octal value.
316 *
317 * @str: Pointer to the string.
318 *
319 * Returns true if @str is a \ooo style octal value, false otherwise.
320 *
321 * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
322 * This function verifies that \ooo is in valid range.
323 */
324static inline bool tomoyo_byte_range(const char *str)
325{
326	return *str >= '0' && *str++ <= '3' &&
327		*str >= '0' && *str++ <= '7' &&
328		*str >= '0' && *str <= '7';
329}
330
331/**
332 * tomoyo_alphabet_char - Check whether the character is an alphabet.
333 *
334 * @c: The character to check.
335 *
336 * Returns true if @c is an alphabet character, false otherwise.
337 */
338static inline bool tomoyo_alphabet_char(const char c)
339{
340	return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
341}
342
343/**
344 * tomoyo_make_byte - Make byte value from three octal characters.
345 *
346 * @c1: The first character.
347 * @c2: The second character.
348 * @c3: The third character.
349 *
350 * Returns byte value.
351 */
352static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
353{
354	return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
355}
356
357/**
358 * tomoyo_valid - Check whether the character is a valid char.
359 *
360 * @c: The character to check.
361 *
362 * Returns true if @c is a valid character, false otherwise.
363 */
364static inline bool tomoyo_valid(const unsigned char c)
365{
366	return c > ' ' && c < 127;
367}
368
369/**
370 * tomoyo_invalid - Check whether the character is an invalid char.
371 *
372 * @c: The character to check.
373 *
374 * Returns true if @c is an invalid character, false otherwise.
375 */
376static inline bool tomoyo_invalid(const unsigned char c)
377{
378	return c && (c <= ' ' || c >= 127);
379}
380
381/**
382 * tomoyo_str_starts - Check whether the given string starts with the given keyword.
383 *
384 * @src:  Pointer to pointer to the string.
385 * @find: Pointer to the keyword.
386 *
387 * Returns true if @src starts with @find, false otherwise.
388 *
389 * The @src is updated to point the first character after the @find
390 * if @src starts with @find.
391 */
392bool tomoyo_str_starts(char **src, const char *find)
393{
394	const int len = strlen(find);
395	char *tmp = *src;
396
397	if (strncmp(tmp, find, len))
398		return false;
399	tmp += len;
400	*src = tmp;
401	return true;
402}
403
404/**
405 * tomoyo_normalize_line - Format string.
406 *
407 * @buffer: The line to normalize.
408 *
409 * Leading and trailing whitespaces are removed.
410 * Multiple whitespaces are packed into single space.
411 *
412 * Returns nothing.
413 */
414void tomoyo_normalize_line(unsigned char *buffer)
415{
416	unsigned char *sp = buffer;
417	unsigned char *dp = buffer;
418	bool first = true;
419
420	while (tomoyo_invalid(*sp))
421		sp++;
422	while (*sp) {
423		if (!first)
424			*dp++ = ' ';
425		first = false;
426		while (tomoyo_valid(*sp))
427			*dp++ = *sp++;
428		while (tomoyo_invalid(*sp))
429			sp++;
430	}
431	*dp = '\0';
432}
433
434/**
435 * tomoyo_correct_word2 - Validate a string.
436 *
437 * @string: The string to check. Maybe non-'\0'-terminated.
438 * @len:    Length of @string.
439 *
440 * Check whether the given string follows the naming rules.
441 * Returns true if @string follows the naming rules, false otherwise.
442 */
443static bool tomoyo_correct_word2(const char *string, size_t len)
444{
445	const char *const start = string;
446	bool in_repetition = false;
447	unsigned char c;
448	unsigned char d;
449	unsigned char e;
450	if (!len)
451		goto out;
452	while (len--) {
453		c = *string++;
454		if (c == '\\') {
455			if (!len--)
456				goto out;
457			c = *string++;
458			switch (c) {
459			case '\\':  /* "\\" */
460				continue;
461			case '$':   /* "\$" */
462			case '+':   /* "\+" */
463			case '?':   /* "\?" */
464			case '*':   /* "\*" */
465			case '@':   /* "\@" */
466			case 'x':   /* "\x" */
467			case 'X':   /* "\X" */
468			case 'a':   /* "\a" */
469			case 'A':   /* "\A" */
470			case '-':   /* "\-" */
471				continue;
472			case '{':   /* "/\{" */
473				if (string - 3 < start || *(string - 3) != '/')
474					break;
475				in_repetition = true;
476				continue;
477			case '}':   /* "\}/" */
478				if (*string != '/')
479					break;
480				if (!in_repetition)
481					break;
482				in_repetition = false;
483				continue;
484			case '0':   /* "\ooo" */
485			case '1':
486			case '2':
487			case '3':
488				if (!len-- || !len--)
489					break;
490				d = *string++;
491				e = *string++;
492				if (d < '0' || d > '7' || e < '0' || e > '7')
493					break;
494				c = tomoyo_make_byte(c, d, e);
495				if (c <= ' ' || c >= 127)
496					continue;
497			}
498			goto out;
499		} else if (in_repetition && c == '/') {
500			goto out;
501		} else if (c <= ' ' || c >= 127) {
502			goto out;
503		}
504	}
505	if (in_repetition)
506		goto out;
507	return true;
508 out:
509	return false;
510}
511
512/**
513 * tomoyo_correct_word - Validate a string.
514 *
515 * @string: The string to check.
516 *
517 * Check whether the given string follows the naming rules.
518 * Returns true if @string follows the naming rules, false otherwise.
519 */
520bool tomoyo_correct_word(const char *string)
521{
522	return tomoyo_correct_word2(string, strlen(string));
523}
524
525/**
526 * tomoyo_correct_path - Validate a pathname.
527 *
528 * @filename: The pathname to check.
529 *
530 * Check whether the given pathname follows the naming rules.
531 * Returns true if @filename follows the naming rules, false otherwise.
532 */
533bool tomoyo_correct_path(const char *filename)
534{
535	return *filename == '/' && tomoyo_correct_word(filename);
536}
537
538/**
539 * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.
540 *
541 * @domainname: The domainname to check.
542 *
543 * Returns true if @domainname follows the naming rules, false otherwise.
544 */
545bool tomoyo_correct_domain(const unsigned char *domainname)
546{
547	if (!domainname || !tomoyo_domain_def(domainname))
548		return false;
549	domainname = strchr(domainname, ' ');
550	if (!domainname++)
551		return true;
552	while (1) {
553		const unsigned char *cp = strchr(domainname, ' ');
554		if (!cp)
555			break;
556		if (*domainname != '/' ||
557		    !tomoyo_correct_word2(domainname, cp - domainname))
558			return false;
559		domainname = cp + 1;
560	}
561	return tomoyo_correct_path(domainname);
562}
563
564/**
565 * tomoyo_domain_def - Check whether the given token can be a domainname.
566 *
567 * @buffer: The token to check.
568 *
569 * Returns true if @buffer possibly be a domainname, false otherwise.
570 */
571bool tomoyo_domain_def(const unsigned char *buffer)
572{
573	const unsigned char *cp;
574	int len;
575	if (*buffer != '<')
576		return false;
577	cp = strchr(buffer, ' ');
578	if (!cp)
579		len = strlen(buffer);
580	else
581		len = cp - buffer;
582	if (buffer[len - 1] != '>' ||
583	    !tomoyo_correct_word2(buffer + 1, len - 2))
584		return false;
585	return true;
586}
587
588/**
589 * tomoyo_find_domain - Find a domain by the given name.
590 *
591 * @domainname: The domainname to find.
592 *
593 * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
594 *
595 * Caller holds tomoyo_read_lock().
596 */
597struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
598{
599	struct tomoyo_domain_info *domain;
600	struct tomoyo_path_info name;
601
602	name.name = domainname;
603	tomoyo_fill_path_info(&name);
604	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
605		if (!domain->is_deleted &&
606		    !tomoyo_pathcmp(&name, domain->domainname))
607			return domain;
608	}
609	return NULL;
610}
611
612/**
613 * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
614 *
615 * @filename: The string to evaluate.
616 *
617 * Returns the initial length without a pattern in @filename.
618 */
619static int tomoyo_const_part_length(const char *filename)
620{
621	char c;
622	int len = 0;
623
624	if (!filename)
625		return 0;
626	while ((c = *filename++) != '\0') {
627		if (c != '\\') {
628			len++;
629			continue;
630		}
631		c = *filename++;
632		switch (c) {
633		case '\\':  /* "\\" */
634			len += 2;
635			continue;
636		case '0':   /* "\ooo" */
637		case '1':
638		case '2':
639		case '3':
640			c = *filename++;
641			if (c < '0' || c > '7')
642				break;
643			c = *filename++;
644			if (c < '0' || c > '7')
645				break;
646			len += 4;
647			continue;
648		}
649		break;
650	}
651	return len;
652}
653
654/**
655 * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
656 *
657 * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
658 *
659 * The caller sets "struct tomoyo_path_info"->name.
660 */
661void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
662{
663	const char *name = ptr->name;
664	const int len = strlen(name);
665
666	ptr->const_len = tomoyo_const_part_length(name);
667	ptr->is_dir = len && (name[len - 1] == '/');
668	ptr->is_patterned = (ptr->const_len < len);
669	ptr->hash = full_name_hash(name, len);
670}
671
672/**
673 * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
674 *
675 * @filename:     The start of string to check.
676 * @filename_end: The end of string to check.
677 * @pattern:      The start of pattern to compare.
678 * @pattern_end:  The end of pattern to compare.
679 *
680 * Returns true if @filename matches @pattern, false otherwise.
681 */
682static bool tomoyo_file_matches_pattern2(const char *filename,
683					 const char *filename_end,
684					 const char *pattern,
685					 const char *pattern_end)
686{
687	while (filename < filename_end && pattern < pattern_end) {
688		char c;
689		if (*pattern != '\\') {
690			if (*filename++ != *pattern++)
691				return false;
692			continue;
693		}
694		c = *filename;
695		pattern++;
696		switch (*pattern) {
697			int i;
698			int j;
699		case '?':
700			if (c == '/') {
701				return false;
702			} else if (c == '\\') {
703				if (filename[1] == '\\')
704					filename++;
705				else if (tomoyo_byte_range(filename + 1))
706					filename += 3;
707				else
708					return false;
709			}
710			break;
711		case '\\':
712			if (c != '\\')
713				return false;
714			if (*++filename != '\\')
715				return false;
716			break;
717		case '+':
718			if (!isdigit(c))
719				return false;
720			break;
721		case 'x':
722			if (!isxdigit(c))
723				return false;
724			break;
725		case 'a':
726			if (!tomoyo_alphabet_char(c))
727				return false;
728			break;
729		case '0':
730		case '1':
731		case '2':
732		case '3':
733			if (c == '\\' && tomoyo_byte_range(filename + 1)
734			    && strncmp(filename + 1, pattern, 3) == 0) {
735				filename += 3;
736				pattern += 2;
737				break;
738			}
739			return false; /* Not matched. */
740		case '*':
741		case '@':
742			for (i = 0; i <= filename_end - filename; i++) {
743				if (tomoyo_file_matches_pattern2(
744						    filename + i, filename_end,
745						    pattern + 1, pattern_end))
746					return true;
747				c = filename[i];
748				if (c == '.' && *pattern == '@')
749					break;
750				if (c != '\\')
751					continue;
752				if (filename[i + 1] == '\\')
753					i++;
754				else if (tomoyo_byte_range(filename + i + 1))
755					i += 3;
756				else
757					break; /* Bad pattern. */
758			}
759			return false; /* Not matched. */
760		default:
761			j = 0;
762			c = *pattern;
763			if (c == '$') {
764				while (isdigit(filename[j]))
765					j++;
766			} else if (c == 'X') {
767				while (isxdigit(filename[j]))
768					j++;
769			} else if (c == 'A') {
770				while (tomoyo_alphabet_char(filename[j]))
771					j++;
772			}
773			for (i = 1; i <= j; i++) {
774				if (tomoyo_file_matches_pattern2(
775						    filename + i, filename_end,
776						    pattern + 1, pattern_end))
777					return true;
778			}
779			return false; /* Not matched or bad pattern. */
780		}
781		filename++;
782		pattern++;
783	}
784	while (*pattern == '\\' &&
785	       (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
786		pattern += 2;
787	return filename == filename_end && pattern == pattern_end;
788}
789
790/**
791 * tomoyo_file_matches_pattern - Pattern matching without '/' character.
792 *
793 * @filename:     The start of string to check.
794 * @filename_end: The end of string to check.
795 * @pattern:      The start of pattern to compare.
796 * @pattern_end:  The end of pattern to compare.
797 *
798 * Returns true if @filename matches @pattern, false otherwise.
799 */
800static bool tomoyo_file_matches_pattern(const char *filename,
801					const char *filename_end,
802					const char *pattern,
803					const char *pattern_end)
804{
805	const char *pattern_start = pattern;
806	bool first = true;
807	bool result;
808
809	while (pattern < pattern_end - 1) {
810		/* Split at "\-" pattern. */
811		if (*pattern++ != '\\' || *pattern++ != '-')
812			continue;
813		result = tomoyo_file_matches_pattern2(filename,
814						      filename_end,
815						      pattern_start,
816						      pattern - 2);
817		if (first)
818			result = !result;
819		if (result)
820			return false;
821		first = false;
822		pattern_start = pattern;
823	}
824	result = tomoyo_file_matches_pattern2(filename, filename_end,
825					      pattern_start, pattern_end);
826	return first ? result : !result;
827}
828
829/**
830 * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
831 *
832 * @f: The start of string to check.
833 * @p: The start of pattern to compare.
834 *
835 * Returns true if @f matches @p, false otherwise.
836 */
837static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
838{
839	const char *f_delimiter;
840	const char *p_delimiter;
841
842	while (*f && *p) {
843		f_delimiter = strchr(f, '/');
844		if (!f_delimiter)
845			f_delimiter = f + strlen(f);
846		p_delimiter = strchr(p, '/');
847		if (!p_delimiter)
848			p_delimiter = p + strlen(p);
849		if (*p == '\\' && *(p + 1) == '{')
850			goto recursive;
851		if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
852						 p_delimiter))
853			return false;
854		f = f_delimiter;
855		if (*f)
856			f++;
857		p = p_delimiter;
858		if (*p)
859			p++;
860	}
861	/* Ignore trailing "\*" and "\@" in @pattern. */
862	while (*p == '\\' &&
863	       (*(p + 1) == '*' || *(p + 1) == '@'))
864		p += 2;
865	return !*f && !*p;
866 recursive:
867	/*
868	 * The "\{" pattern is permitted only after '/' character.
869	 * This guarantees that below "*(p - 1)" is safe.
870	 * Also, the "\}" pattern is permitted only before '/' character
871	 * so that "\{" + "\}" pair will not break the "\-" operator.
872	 */
873	if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
874	    *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
875		return false; /* Bad pattern. */
876	do {
877		/* Compare current component with pattern. */
878		if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
879						 p_delimiter - 2))
880			break;
881		/* Proceed to next component. */
882		f = f_delimiter;
883		if (!*f)
884			break;
885		f++;
886		/* Continue comparison. */
887		if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
888			return true;
889		f_delimiter = strchr(f, '/');
890	} while (f_delimiter);
891	return false; /* Not matched. */
892}
893
894/**
895 * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
896 *
897 * @filename: The filename to check.
898 * @pattern:  The pattern to compare.
899 *
900 * Returns true if matches, false otherwise.
901 *
902 * The following patterns are available.
903 *   \\     \ itself.
904 *   \ooo   Octal representation of a byte.
905 *   \*     Zero or more repetitions of characters other than '/'.
906 *   \@     Zero or more repetitions of characters other than '/' or '.'.
907 *   \?     1 byte character other than '/'.
908 *   \$     One or more repetitions of decimal digits.
909 *   \+     1 decimal digit.
910 *   \X     One or more repetitions of hexadecimal digits.
911 *   \x     1 hexadecimal digit.
912 *   \A     One or more repetitions of alphabet characters.
913 *   \a     1 alphabet character.
914 *
915 *   \-     Subtraction operator.
916 *
917 *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
918 *               /dir/dir/dir/ ).
919 */
920bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
921				 const struct tomoyo_path_info *pattern)
922{
923	const char *f = filename->name;
924	const char *p = pattern->name;
925	const int len = pattern->const_len;
926
927	/* If @pattern doesn't contain pattern, I can use strcmp(). */
928	if (!pattern->is_patterned)
929		return !tomoyo_pathcmp(filename, pattern);
930	/* Don't compare directory and non-directory. */
931	if (filename->is_dir != pattern->is_dir)
932		return false;
933	/* Compare the initial length without patterns. */
934	if (strncmp(f, p, len))
935		return false;
936	f += len;
937	p += len;
938	return tomoyo_path_matches_pattern2(f, p);
939}
940
941/**
942 * tomoyo_get_exe - Get tomoyo_realpath() of current process.
943 *
944 * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
945 *
946 * This function uses kzalloc(), so the caller must call kfree()
947 * if this function didn't return NULL.
948 */
949const char *tomoyo_get_exe(void)
950{
951	struct file *exe_file;
952	const char *cp;
953	struct mm_struct *mm = current->mm;
954
955	if (!mm)
956		return NULL;
957	exe_file = get_mm_exe_file(mm);
958	if (!exe_file)
959		return NULL;
960
961	cp = tomoyo_realpath_from_path(&exe_file->f_path);
962	fput(exe_file);
963	return cp;
964}
965
966/**
967 * tomoyo_get_mode - Get MAC mode.
968 *
969 * @ns:      Pointer to "struct tomoyo_policy_namespace".
970 * @profile: Profile number.
971 * @index:   Index number of functionality.
972 *
973 * Returns mode.
974 */
975int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
976		    const u8 index)
977{
978	u8 mode;
979	struct tomoyo_profile *p;
980
981	if (!tomoyo_policy_loaded)
982		return TOMOYO_CONFIG_DISABLED;
983	p = tomoyo_profile(ns, profile);
984	mode = p->config[index];
985	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
986		mode = p->config[tomoyo_index2category[index]
987				 + TOMOYO_MAX_MAC_INDEX];
988	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
989		mode = p->default_config;
990	return mode & 3;
991}
992
993/**
994 * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
995 *
996 * @r:      Pointer to "struct tomoyo_request_info" to initialize.
997 * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
998 * @index:  Index number of functionality.
999 *
1000 * Returns mode.
1001 */
1002int tomoyo_init_request_info(struct tomoyo_request_info *r,
1003			     struct tomoyo_domain_info *domain, const u8 index)
1004{
1005	u8 profile;
1006	memset(r, 0, sizeof(*r));
1007	if (!domain)
1008		domain = tomoyo_domain();
1009	r->domain = domain;
1010	profile = domain->profile;
1011	r->profile = profile;
1012	r->type = index;
1013	r->mode = tomoyo_get_mode(domain->ns, profile, index);
1014	return r->mode;
1015}
1016
1017/**
1018 * tomoyo_domain_quota_is_ok - Check for domain's quota.
1019 *
1020 * @r: Pointer to "struct tomoyo_request_info".
1021 *
1022 * Returns true if the domain is not exceeded quota, false otherwise.
1023 *
1024 * Caller holds tomoyo_read_lock().
1025 */
1026bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
1027{
1028	unsigned int count = 0;
1029	struct tomoyo_domain_info *domain = r->domain;
1030	struct tomoyo_acl_info *ptr;
1031
1032	if (r->mode != TOMOYO_CONFIG_LEARNING)
1033		return false;
1034	if (!domain)
1035		return true;
1036	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
1037		u16 perm;
1038		u8 i;
1039		if (ptr->is_deleted)
1040			continue;
1041		switch (ptr->type) {
1042		case TOMOYO_TYPE_PATH_ACL:
1043			perm = container_of(ptr, struct tomoyo_path_acl, head)
1044				->perm;
1045			break;
1046		case TOMOYO_TYPE_PATH2_ACL:
1047			perm = container_of(ptr, struct tomoyo_path2_acl, head)
1048				->perm;
1049			break;
1050		case TOMOYO_TYPE_PATH_NUMBER_ACL:
1051			perm = container_of(ptr, struct tomoyo_path_number_acl,
1052					    head)->perm;
1053			break;
1054		case TOMOYO_TYPE_MKDEV_ACL:
1055			perm = container_of(ptr, struct tomoyo_mkdev_acl,
1056					    head)->perm;
1057			break;
1058		case TOMOYO_TYPE_INET_ACL:
1059			perm = container_of(ptr, struct tomoyo_inet_acl,
1060					    head)->perm;
1061			break;
1062		case TOMOYO_TYPE_UNIX_ACL:
1063			perm = container_of(ptr, struct tomoyo_unix_acl,
1064					    head)->perm;
1065			break;
1066		case TOMOYO_TYPE_MANUAL_TASK_ACL:
1067			perm = 0;
1068			break;
1069		default:
1070			perm = 1;
1071		}
1072		for (i = 0; i < 16; i++)
1073			if (perm & (1 << i))
1074				count++;
1075	}
1076	if (count < tomoyo_profile(domain->ns, domain->profile)->
1077	    pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
1078		return true;
1079	if (!domain->flags[TOMOYO_DIF_QUOTA_WARNED]) {
1080		domain->flags[TOMOYO_DIF_QUOTA_WARNED] = true;
1081		/* r->granted = false; */
1082		tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
1083		printk(KERN_WARNING "WARNING: "
1084		       "Domain '%s' has too many ACLs to hold. "
1085		       "Stopped learning mode.\n", domain->domainname->name);
1086	}
1087	return false;
1088}
1089