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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. */
11 DEFINE_MUTEX(tomoyo_policy_lock);
12 
13 /* Has /sbin/init started? */
14 bool tomoyo_policy_loaded;
15 
16 /*
17  * Mapping table from "enum tomoyo_mac_index" to
18  * "enum tomoyo_mac_category_index".
19  */
20 const 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  */
tomoyo_convert_time(time_t time,struct tomoyo_time * stamp)90 void 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  */
tomoyo_permstr(const char * string,const char * keyword)131 bool 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  */
tomoyo_read_token(struct tomoyo_acl_param * param)149 char *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  */
tomoyo_get_domainname(struct tomoyo_acl_param * param)168 const 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  */
tomoyo_parse_ulong(unsigned long * result,char ** str)197 u8 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  */
tomoyo_print_ulong(char * buffer,const int buffer_len,const unsigned long value,const u8 type)236 void 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  */
tomoyo_parse_name_union(struct tomoyo_acl_param * param,struct tomoyo_name_union * ptr)257 bool 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  */
tomoyo_parse_number_union(struct tomoyo_acl_param * param,struct tomoyo_number_union * ptr)281 bool 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  */
tomoyo_byte_range(const char * str)324 static 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  */
tomoyo_alphabet_char(const char c)338 static 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  */
tomoyo_make_byte(const u8 c1,const u8 c2,const u8 c3)352 static 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  */
tomoyo_valid(const unsigned char c)364 static 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  */
tomoyo_invalid(const unsigned char c)376 static 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  */
tomoyo_str_starts(char ** src,const char * find)392 bool 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  */
tomoyo_normalize_line(unsigned char * buffer)414 void 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  */
tomoyo_correct_word2(const char * string,size_t len)443 static 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  */
tomoyo_correct_word(const char * string)520 bool 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  */
tomoyo_correct_path(const char * filename)533 bool 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  */
tomoyo_correct_domain(const unsigned char * domainname)545 bool 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  */
tomoyo_domain_def(const unsigned char * buffer)571 bool 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  */
tomoyo_find_domain(const char * domainname)597 struct 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  */
tomoyo_const_part_length(const char * filename)619 static 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  */
tomoyo_fill_path_info(struct tomoyo_path_info * ptr)661 void 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  */
tomoyo_file_matches_pattern2(const char * filename,const char * filename_end,const char * pattern,const char * pattern_end)682 static 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  */
tomoyo_file_matches_pattern(const char * filename,const char * filename_end,const char * pattern,const char * pattern_end)800 static 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  */
tomoyo_path_matches_pattern2(const char * f,const char * p)837 static 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  */
tomoyo_path_matches_pattern(const struct tomoyo_path_info * filename,const struct tomoyo_path_info * pattern)920 bool 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  */
tomoyo_get_exe(void)949 const char *tomoyo_get_exe(void)
950 {
951 	struct mm_struct *mm = current->mm;
952 	const char *cp = NULL;
953 
954 	if (!mm)
955 		return NULL;
956 	down_read(&mm->mmap_sem);
957 	if (mm->exe_file)
958 		cp = tomoyo_realpath_from_path(&mm->exe_file->f_path);
959 	up_read(&mm->mmap_sem);
960 	return cp;
961 }
962 
963 /**
964  * tomoyo_get_mode - Get MAC mode.
965  *
966  * @ns:      Pointer to "struct tomoyo_policy_namespace".
967  * @profile: Profile number.
968  * @index:   Index number of functionality.
969  *
970  * Returns mode.
971  */
tomoyo_get_mode(const struct tomoyo_policy_namespace * ns,const u8 profile,const u8 index)972 int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
973 		    const u8 index)
974 {
975 	u8 mode;
976 	struct tomoyo_profile *p;
977 
978 	if (!tomoyo_policy_loaded)
979 		return TOMOYO_CONFIG_DISABLED;
980 	p = tomoyo_profile(ns, profile);
981 	mode = p->config[index];
982 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
983 		mode = p->config[tomoyo_index2category[index]
984 				 + TOMOYO_MAX_MAC_INDEX];
985 	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
986 		mode = p->default_config;
987 	return mode & 3;
988 }
989 
990 /**
991  * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
992  *
993  * @r:      Pointer to "struct tomoyo_request_info" to initialize.
994  * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
995  * @index:  Index number of functionality.
996  *
997  * Returns mode.
998  */
tomoyo_init_request_info(struct tomoyo_request_info * r,struct tomoyo_domain_info * domain,const u8 index)999 int tomoyo_init_request_info(struct tomoyo_request_info *r,
1000 			     struct tomoyo_domain_info *domain, const u8 index)
1001 {
1002 	u8 profile;
1003 	memset(r, 0, sizeof(*r));
1004 	if (!domain)
1005 		domain = tomoyo_domain();
1006 	r->domain = domain;
1007 	profile = domain->profile;
1008 	r->profile = profile;
1009 	r->type = index;
1010 	r->mode = tomoyo_get_mode(domain->ns, profile, index);
1011 	return r->mode;
1012 }
1013 
1014 /**
1015  * tomoyo_domain_quota_is_ok - Check for domain's quota.
1016  *
1017  * @r: Pointer to "struct tomoyo_request_info".
1018  *
1019  * Returns true if the domain is not exceeded quota, false otherwise.
1020  *
1021  * Caller holds tomoyo_read_lock().
1022  */
tomoyo_domain_quota_is_ok(struct tomoyo_request_info * r)1023 bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
1024 {
1025 	unsigned int count = 0;
1026 	struct tomoyo_domain_info *domain = r->domain;
1027 	struct tomoyo_acl_info *ptr;
1028 
1029 	if (r->mode != TOMOYO_CONFIG_LEARNING)
1030 		return false;
1031 	if (!domain)
1032 		return true;
1033 	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
1034 		u16 perm;
1035 		u8 i;
1036 		if (ptr->is_deleted)
1037 			continue;
1038 		switch (ptr->type) {
1039 		case TOMOYO_TYPE_PATH_ACL:
1040 			perm = container_of(ptr, struct tomoyo_path_acl, head)
1041 				->perm;
1042 			break;
1043 		case TOMOYO_TYPE_PATH2_ACL:
1044 			perm = container_of(ptr, struct tomoyo_path2_acl, head)
1045 				->perm;
1046 			break;
1047 		case TOMOYO_TYPE_PATH_NUMBER_ACL:
1048 			perm = container_of(ptr, struct tomoyo_path_number_acl,
1049 					    head)->perm;
1050 			break;
1051 		case TOMOYO_TYPE_MKDEV_ACL:
1052 			perm = container_of(ptr, struct tomoyo_mkdev_acl,
1053 					    head)->perm;
1054 			break;
1055 		case TOMOYO_TYPE_INET_ACL:
1056 			perm = container_of(ptr, struct tomoyo_inet_acl,
1057 					    head)->perm;
1058 			break;
1059 		case TOMOYO_TYPE_UNIX_ACL:
1060 			perm = container_of(ptr, struct tomoyo_unix_acl,
1061 					    head)->perm;
1062 			break;
1063 		case TOMOYO_TYPE_MANUAL_TASK_ACL:
1064 			perm = 0;
1065 			break;
1066 		default:
1067 			perm = 1;
1068 		}
1069 		for (i = 0; i < 16; i++)
1070 			if (perm & (1 << i))
1071 				count++;
1072 	}
1073 	if (count < tomoyo_profile(domain->ns, domain->profile)->
1074 	    pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
1075 		return true;
1076 	if (!domain->flags[TOMOYO_DIF_QUOTA_WARNED]) {
1077 		domain->flags[TOMOYO_DIF_QUOTA_WARNED] = true;
1078 		/* r->granted = false; */
1079 		tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
1080 		printk(KERN_WARNING "WARNING: "
1081 		       "Domain '%s' has too many ACLs to hold. "
1082 		       "Stopped learning mode.\n", domain->domainname->name);
1083 	}
1084 	return false;
1085 }
1086