summaryrefslogtreecommitdiffstats
path: root/security/tomoyo/util.c
blob: a1c3d9ccebfa4572a05f3a1a3952f8d1a8af7113 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
/*
 * security/tomoyo/util.c
 *
 * Copyright (C) 2005-2011  NTT DATA CORPORATION
 */

#include <linux/slab.h>
#include "common.h"

/* Lock for protecting policy. */
DEFINE_MUTEX(tomoyo_policy_lock);

/* Has /sbin/init started? */
bool tomoyo_policy_loaded;

/*
 * Mapping table from "enum tomoyo_mac_index" to
 * "enum tomoyo_mac_category_index".
 */
const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = {
	/* CONFIG::file group */
	[TOMOYO_MAC_FILE_EXECUTE]    = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_OPEN]       = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_CREATE]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_UNLINK]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_GETATTR]    = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MKDIR]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_RMDIR]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MKFIFO]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MKSOCK]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_TRUNCATE]   = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_SYMLINK]    = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MKBLOCK]    = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MKCHAR]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_LINK]       = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_RENAME]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_CHMOD]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_CHOWN]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_CHGRP]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_IOCTL]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_CHROOT]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MOUNT]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_UMOUNT]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_PIVOT_ROOT] = TOMOYO_MAC_CATEGORY_FILE,
	/* CONFIG::network group */
	[TOMOYO_MAC_NETWORK_INET_STREAM_BIND]       =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN]     =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT]    =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_INET_DGRAM_BIND]        =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_INET_DGRAM_SEND]        =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_INET_RAW_BIND]          =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_INET_RAW_SEND]          =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND]       =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN]     =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT]    =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND]        =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND]        =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND]    =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN]  =
	TOMOYO_MAC_CATEGORY_NETWORK,
	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT] =
	TOMOYO_MAC_CATEGORY_NETWORK,
	/* CONFIG::misc group */
	[TOMOYO_MAC_ENVIRON]         = TOMOYO_MAC_CATEGORY_MISC,
};

/**
 * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
 *
 * @time:  Seconds since 1970/01/01 00:00:00.
 * @stamp: Pointer to "struct tomoyo_time".
 *
 * Returns nothing.
 *
 * This function does not handle Y2038 problem.
 */
void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
{
	static const u16 tomoyo_eom[2][12] = {
		{ 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
		{ 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
	};
	u16 y;
	u8 m;
	bool r;
	stamp->sec = time % 60;
	time /= 60;
	stamp->min = time % 60;
	time /= 60;
	stamp->hour = time % 24;
	time /= 24;
	for (y = 1970; ; y++) {
		const unsigned short days = (y & 3) ? 365 : 366;
		if (time < days)
			break;
		time -= days;
	}
	r = (y & 3) == 0;
	for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
		;
	if (m)
		time -= tomoyo_eom[r][m - 1];
	stamp->year = y;
	stamp->month = ++m;
	stamp->day = ++time;
}

/**
 * tomoyo_permstr - Find permission keywords.
 *
 * @string: String representation for permissions in foo/bar/buz format.
 * @keyword: Keyword to find from @string/
 *
 * Returns ture if @keyword was found in @string, false otherwise.
 *
 * This function assumes that strncmp(w1, w2, strlen(w1)) != 0 if w1 != w2.
 */
bool tomoyo_permstr(const char *string, const char *keyword)
{
	const char *cp = strstr(string, keyword);
	if (cp)
		return cp == string || *(cp - 1) == '/';
	return false;
}

/**
 * tomoyo_read_token - Read a word from a line.
 *
 * @param: Pointer to "struct tomoyo_acl_param".
 *
 * Returns a word on success, "" otherwise.
 *
 * To allow the caller to skip NULL check, this function returns "" rather than
 * NULL if there is no more words to read.
 */
char *tomoyo_read_token(struct tomoyo_acl_param *param)
{
	char *pos = param->data;
	char *del = strchr(pos, ' ');
	if (del)
		*del++ = '\0';
	else
		del = pos + strlen(pos);
	param->data = del;
	return pos;
}

/**
 * tomoyo_parse_ulong - Parse an "unsigned long" value.
 *
 * @result: Pointer to "unsigned long".
 * @str:    Pointer to string to parse.
 *
 * Returns one of values in "enum tomoyo_value_type".
 *
 * The @src is updated to point the first character after the value
 * on success.
 */
u8 tomoyo_parse_ulong(unsigned long *result, char **str)
{
	const char *cp = *str;
	char *ep;
	int base = 10;
	if (*cp == '0') {
		char c = *(cp + 1);
		if (c == 'x' || c == 'X') {
			base = 16;
			cp += 2;
		} else if (c >= '0' && c <= '7') {
			base = 8;
			cp++;
		}
	}
	*result = simple_strtoul(cp, &ep, base);
	if (cp == ep)
		return TOMOYO_VALUE_TYPE_INVALID;
	*str = ep;
	switch (base) {
	case 16:
		return TOMOYO_VALUE_TYPE_HEXADECIMAL;
	case 8:
		return TOMOYO_VALUE_TYPE_OCTAL;
	default:
		return TOMOYO_VALUE_TYPE_DECIMAL;
	}
}

/**
 * tomoyo_print_ulong - Print an "unsigned long" value.
 *
 * @buffer:     Pointer to buffer.
 * @buffer_len: Size of @buffer.
 * @value:      An "unsigned long" value.
 * @type:       Type of @value.
 *
 * Returns nothing.
 */
void tomoyo_print_ulong(char *buffer, const int buffer_len,
			const unsigned long value, const u8 type)
{
	if (type == TOMOYO_VALUE_TYPE_DECIMAL)
		snprintf(buffer, buffer_len, "%lu", value);
	else if (type == TOMOYO_VALUE_TYPE_OCTAL)
		snprintf(buffer, buffer_len, "0%lo", value);
	else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL)
		snprintf(buffer, buffer_len, "0x%lX", value);
	else
		snprintf(buffer, buffer_len, "type(%u)", type);
}

/**
 * tomoyo_parse_name_union - Parse a tomoyo_name_union.
 *
 * @param: Pointer to "struct tomoyo_acl_param".
 * @ptr:   Pointer to "struct tomoyo_name_union".
 *
 * Returns true on success, false otherwise.
 */
bool tomoyo_parse_name_union(struct tomoyo_acl_param *param,
			     struct tomoyo_name_union *ptr)
{
	char *filename;
	if (param->data[0] == '@') {
		param->data++;
		ptr->group = tomoyo_get_group(param, TOMOYO_PATH_GROUP);
		return ptr->group != NULL;
	}
	filename = tomoyo_read_token(param);
	if (!tomoyo_correct_word(filename))
		return false;
	ptr->filename = tomoyo_get_name(filename);
	return ptr->filename != NULL;
}

/**
 * tomoyo_parse_number_union - Parse a tomoyo_number_union.
 *
 * @param: Pointer to "struct tomoyo_acl_param".
 * @ptr:   Pointer to "struct tomoyo_number_union".
 *
 * Returns true on success, false otherwise.
 */
bool tomoyo_parse_number_union(struct tomoyo_acl_param *param,
			       struct tomoyo_number_union *ptr)
{
	char *data;
	u8 type;
	unsigned long v;
	memset(ptr, 0, sizeof(*ptr));
	if (param->data[0] == '@') {
		param->data++;
		ptr->group = tomoyo_get_group(param, TOMOYO_NUMBER_GROUP);
		return ptr->group != NULL;
	}
	data = tomoyo_read_token(param);
	type = tomoyo_parse_ulong(&v, &data);
	if (type == TOMOYO_VALUE_TYPE_INVALID)
		return false;
	ptr->values[0] = v;
	ptr->value_type[0] = type;
	if (!*data) {
		ptr->values[1] = v;
		ptr->value_type[1] = type;
		return true;
	}
	if (*data++ != '-')
		return false;
	type = tomoyo_parse_ulong(&v, &data);
	if (type == TOMOYO_VALUE_TYPE_INVALID || *data || ptr->values[0] > v)
		return false;
	ptr->values[1] = v;
	ptr->value_type[1] = type;
	return true;
}

/**
 * tomoyo_byte_range - Check whether the string is a \ooo style octal value.
 *
 * @str: Pointer to the string.
 *
 * Returns true if @str is a \ooo style octal value, false otherwise.
 *
 * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
 * This function verifies that \ooo is in valid range.
 */
static inline bool tomoyo_byte_range(const char *str)
{
	return *str >= '0' && *str++ <= '3' &&
		*str >= '0' && *str++ <= '7' &&
		*str >= '0' && *str <= '7';
}

/**
 * tomoyo_alphabet_char - Check whether the character is an alphabet.
 *
 * @c: The character to check.
 *
 * Returns true if @c is an alphabet character, false otherwise.
 */
static inline bool tomoyo_alphabet_char(const char c)
{
	return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
}

/**
 * tomoyo_make_byte - Make byte value from three octal characters.
 *
 * @c1: The first character.
 * @c2: The second character.
 * @c3: The third character.
 *
 * Returns byte value.
 */
static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
{
	return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
}

/**
 * tomoyo_valid - Check whether the character is a valid char.
 *
 * @c: The character to check.
 *
 * Returns true if @c is a valid character, false otherwise.
 */
static inline bool tomoyo_valid(const unsigned char c)
{
	return c > ' ' && c < 127;
}

/**
 * tomoyo_invalid - Check whether the character is an invalid char.
 *
 * @c: The character to check.
 *
 * Returns true if @c is an invalid character, false otherwise.
 */
static inline bool tomoyo_invalid(const unsigned char c)
{
	return c && (c <= ' ' || c >= 127);
}

/**
 * tomoyo_str_starts - Check whether the given string starts with the given keyword.
 *
 * @src:  Pointer to pointer to the string.
 * @find: Pointer to the keyword.
 *
 * Returns true if @src starts with @find, false otherwise.
 *
 * The @src is updated to point the first character after the @find
 * if @src starts with @find.
 */
bool tomoyo_str_starts(char **src, const char *find)
{
	const int len = strlen(find);
	char *tmp = *src;

	if (strncmp(tmp, find, len))
		return false;
	tmp += len;
	*src = tmp;
	return true;
}

/**
 * tomoyo_normalize_line - Format string.
 *
 * @buffer: The line to normalize.
 *
 * Leading and trailing whitespaces are removed.
 * Multiple whitespaces are packed into single space.
 *
 * Returns nothing.
 */
void tomoyo_normalize_line(unsigned char *buffer)
{
	unsigned char *sp = buffer;
	unsigned char *dp = buffer;
	bool first = true;

	while (tomoyo_invalid(*sp))
		sp++;
	while (*sp) {
		if (!first)
			*dp++ = ' ';
		first = false;
		while (tomoyo_valid(*sp))
			*dp++ = *sp++;
		while (tomoyo_invalid(*sp))
			sp++;
	}
	*dp = '\0';
}

/**
 * tomoyo_correct_word2 - Validate a string.
 *
 * @string: The string to check. Maybe non-'\0'-terminated.
 * @len:    Length of @string.
 *
 * Check whether the given string follows the naming rules.
 * Returns true if @string follows the naming rules, false otherwise.
 */
static bool tomoyo_correct_word2(const char *string, size_t len)
{
	const char *const start = string;
	bool in_repetition = false;
	unsigned char c;
	unsigned char d;
	unsigned char e;
	if (!len)
		goto out;
	while (len--) {
		c = *string++;
		if (c == '\\') {
			if (!len--)
				goto out;
			c = *string++;
			switch (c) {
			case '\\':  /* "\\" */
				continue;
			case '$':   /* "\$" */
			case '+':   /* "\+" */
			case '?':   /* "\?" */
			case '*':   /* "\*" */
			case '@':   /* "\@" */
			case 'x':   /* "\x" */
			case 'X':   /* "\X" */
			case 'a':   /* "\a" */
			case 'A':   /* "\A" */
			case '-':   /* "\-" */
				continue;
			case '{':   /* "/\{" */
				if (string - 3 < start || *(string - 3) != '/')
					break;
				in_repetition = true;
				continue;
			case '}':   /* "\}/" */
				if (*string != '/')
					break;
				if (!in_repetition)
					break;
				in_repetition = false;
				continue;
			case '0':   /* "\ooo" */
			case '1':
			case '2':
			case '3':
				if (!len-- || !len--)
					break;
				d = *string++;
				e = *string++;
				if (d < '0' || d > '7' || e < '0' || e > '7')
					break;
				c = tomoyo_make_byte(c, d, e);
				if (tomoyo_invalid(c))
					continue; /* pattern is not \000 */
			}
			goto out;
		} else if (in_repetition && c == '/') {
			goto out;
		} else if (tomoyo_invalid(c)) {
			goto out;
		}
	}
	if (in_repetition)
		goto out;
	return true;
 out:
	return false;
}

/**
 * tomoyo_correct_word - Validate a string.
 *
 * @string: The string to check.
 *
 * Check whether the given string follows the naming rules.
 * Returns true if @string follows the naming rules, false otherwise.
 */
bool tomoyo_correct_word(const char *string)
{
	return tomoyo_correct_word2(string, strlen(string));
}

/**
 * tomoyo_correct_path - Validate a pathname.
 *
 * @filename: The pathname to check.
 *
 * Check whether the given pathname follows the naming rules.
 * Returns true if @filename follows the naming rules, false otherwise.
 */
bool tomoyo_correct_path(const char *filename)
{
	return *filename == '/' && tomoyo_correct_word(filename);
}

/**
 * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.
 *
 * @domainname: The domainname to check.
 *
 * Returns true if @domainname follows the naming rules, false otherwise.
 */
bool tomoyo_correct_domain(const unsigned char *domainname)
{
	if (!domainname || !tomoyo_domain_def(domainname))
		return false;
	domainname = strchr(domainname, ' ');
	if (!domainname++)
		return true;
	while (1) {
		const unsigned char *cp = strchr(domainname, ' ');
		if (!cp)
			break;
		if (*domainname != '/' ||
		    !tomoyo_correct_word2(domainname, cp - domainname))
			return false;
		domainname = cp + 1;
	}
	return tomoyo_correct_path(domainname);
}

/**
 * tomoyo_domain_def - Check whether the given token can be a domainname.
 *
 * @buffer: The token to check.
 *
 * Returns true if @buffer possibly be a domainname, false otherwise.
 */
bool tomoyo_domain_def(const unsigned char *buffer)
{
	const unsigned char *cp;
	int len;
	if (*buffer != '<')
		return false;
	cp = strchr(buffer, ' ');
	if (!cp)
		len = strlen(buffer);
	else
		len = cp - buffer;
	if (buffer[len - 1] != '>' ||
	    !tomoyo_correct_word2(buffer + 1, len - 2))
		return false;
	return true;
}

/**
 * tomoyo_find_domain - Find a domain by the given name.
 *
 * @domainname: The domainname to find.
 *
 * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
{
	struct tomoyo_domain_info *domain;
	struct tomoyo_path_info name;

	name.name = domainname;
	tomoyo_fill_path_info(&name);
	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
		if (!domain->is_deleted &&
		    !tomoyo_pathcmp(&name, domain->domainname))
			return domain;
	}
	return NULL;
}

/**
 * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
 *
 * @filename: The string to evaluate.
 *
 * Returns the initial length without a pattern in @filename.
 */
static int tomoyo_const_part_length(const char *filename)
{
	char c;
	int len = 0;

	if (!filename)
		return 0;
	while ((c = *filename++) != '\0') {
		if (c != '\\') {
			len++;
			continue;
		}
		c = *filename++;
		switch (c) {
		case '\\':  /* "\\" */
			len += 2;
			continue;
		case '0':   /* "\ooo" */
		case '1':
		case '2':
		case '3':
			c = *filename++;
			if (c < '0' || c > '7')
				break;
			c = *filename++;
			if (c < '0' || c > '7')
				break;
			len += 4;
			continue;
		}
		break;
	}
	return len;
}

/**
 * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
 *
 * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
 *
 * The caller sets "struct tomoyo_path_info"->name.
 */
void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
{
	const char *name = ptr->name;
	const int len = strlen(name);

	ptr->const_len = tomoyo_const_part_length(name);
	ptr->is_dir = len && (name[len - 1] == '/');
	ptr->is_patterned = (ptr->const_len < len);
	ptr->hash = full_name_hash(name, len);
}

/**
 * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
 *
 * @filename:     The start of string to check.
 * @filename_end: The end of string to check.
 * @pattern:      The start of pattern to compare.
 * @pattern_end:  The end of pattern to compare.
 *
 * Returns true if @filename matches @pattern, false otherwise.
 */
static bool tomoyo_file_matches_pattern2(const char *filename,
					 const char *filename_end,
					 const char *pattern,
					 const char *pattern_end)
{
	while (filename < filename_end && pattern < pattern_end) {
		char c;
		if (*pattern != '\\') {
			if (*filename++ != *pattern++)
				return false;
			continue;
		}
		c = *filename;
		pattern++;
		switch (*pattern) {
			int i;
			int j;
		case '?':
			if (c == '/') {
				return false;
			} else if (c == '\\') {
				if (filename[1] == '\\')
					filename++;
				else if (tomoyo_byte_range(filename + 1))
					filename += 3;
				else
					return false;
			}
			break;
		case '\\':
			if (c != '\\')
				return false;
			if (*++filename != '\\')
				return false;
			break;
		case '+':
			if (!isdigit(c))
				return false;
			break;
		case 'x':
			if (!isxdigit(c))
				return false;
			break;
		case 'a':
			if (!tomoyo_alphabet_char(c))
				return false;
			break;
		case '0':
		case '1':
		case '2':
		case '3':
			if (c == '\\' && tomoyo_byte_range(filename + 1)
			    && strncmp(filename + 1, pattern, 3) == 0) {
				filename += 3;
				pattern += 2;
				break;
			}
			return false; /* Not matched. */
		case '*':
		case '@':
			for (i = 0; i <= filename_end - filename; i++) {
				if (tomoyo_file_matches_pattern2(
						    filename + i, filename_end,
						    pattern + 1, pattern_end))
					return true;
				c = filename[i];
				if (c == '.' && *pattern == '@')
					break;
				if (c != '\\')
					continue;
				if (filename[i + 1] == '\\')
					i++;
				else if (tomoyo_byte_range(filename + i + 1))
					i += 3;
				else
					break; /* Bad pattern. */
			}
			return false; /* Not matched. */
		default:
			j = 0;
			c = *pattern;
			if (c == '$') {
				while (isdigit(filename[j]))
					j++;
			} else if (c == 'X') {
				while (isxdigit(filename[j]))
					j++;
			} else if (c == 'A') {
				while (tomoyo_alphabet_char(filename[j]))
					j++;
			}
			for (i = 1; i <= j; i++) {
				if (tomoyo_file_matches_pattern2(
						    filename + i, filename_end,
						    pattern + 1, pattern_end))
					return true;
			}
			return false; /* Not matched or bad pattern. */
		}
		filename++;
		pattern++;
	}
	while (*pattern == '\\' &&
	       (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
		pattern += 2;
	return filename == filename_end && pattern == pattern_end;
}

/**
 * tomoyo_file_matches_pattern - Pattern matching without '/' character.
 *
 * @filename:     The start of string to check.
 * @filename_end: The end of string to check.
 * @pattern:      The start of pattern to compare.
 * @pattern_end:  The end of pattern to compare.
 *
 * Returns true if @filename matches @pattern, false otherwise.
 */
static bool tomoyo_file_matches_pattern(const char *filename,
					const char *filename_end,
					const char *pattern,
					const char *pattern_end)
{
	const char *pattern_start = pattern;
	bool first = true;
	bool result;

	while (pattern < pattern_end - 1) {
		/* Split at "\-" pattern. */
		if (*pattern++ != '\\' || *pattern++ != '-')
			continue;
		result = tomoyo_file_matches_pattern2(filename,
						      filename_end,
						      pattern_start,
						      pattern - 2);
		if (first)
			result = !result;
		if (result)
			return false;
		first = false;
		pattern_start = pattern;
	}
	result = tomoyo_file_matches_pattern2(filename, filename_end,
					      pattern_start, pattern_end);
	return first ? result : !result;
}

/**
 * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
 *
 * @f: The start of string to check.
 * @p: The start of pattern to compare.
 *
 * Returns true if @f matches @p, false otherwise.
 */
static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
{
	const char *f_delimiter;
	const char *p_delimiter;

	while (*f && *p) {
		f_delimiter = strchr(f, '/');
		if (!f_delimiter)
			f_delimiter = f + strlen(f);
		p_delimiter = strchr(p, '/');
		if (!p_delimiter)
			p_delimiter = p + strlen(p);
		if (*p == '\\' && *(p + 1) == '{')
			goto recursive;
		if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
						 p_delimiter))
			return false;
		f = f_delimiter;
		if (*f)
			f++;
		p = p_delimiter;
		if (*p)
			p++;
	}
	/* Ignore trailing "\*" and "\@" in @pattern. */
	while (*p == '\\' &&
	       (*(p + 1) == '*' || *(p + 1) == '@'))
		p += 2;
	return !*f && !*p;
 recursive:
	/*
	 * The "\{" pattern is permitted only after '/' character.
	 * This guarantees that below "*(p - 1)" is safe.
	 * Also, the "\}" pattern is permitted only before '/' character
	 * so that "\{" + "\}" pair will not break the "\-" operator.
	 */
	if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
	    *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
		return false; /* Bad pattern. */
	do {
		/* Compare current component with pattern. */
		if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
						 p_delimiter - 2))
			break;
		/* Proceed to next component. */
		f = f_delimiter;
		if (!*f)
			break;
		f++;
		/* Continue comparison. */
		if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
			return true;
		f_delimiter = strchr(f, '/');
	} while (f_delimiter);
	return false; /* Not matched. */
}

/**
 * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
 *
 * @filename: The filename to check.
 * @pattern:  The pattern to compare.
 *
 * Returns true if matches, false otherwise.
 *
 * The following patterns are available.
 *   \\     \ itself.
 *   \ooo   Octal representation of a byte.
 *   \*     Zero or more repetitions of characters other than '/'.
 *   \@     Zero or more repetitions of characters other than '/' or '.'.
 *   \?     1 byte character other than '/'.
 *   \$     One or more repetitions of decimal digits.
 *   \+     1 decimal digit.
 *   \X     One or more repetitions of hexadecimal digits.
 *   \x     1 hexadecimal digit.
 *   \A     One or more repetitions of alphabet characters.
 *   \a     1 alphabet character.
 *
 *   \-     Subtraction operator.
 *
 *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
 *               /dir/dir/dir/ ).
 */
bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
				 const struct tomoyo_path_info *pattern)
{
	const char *f = filename->name;
	const char *p = pattern->name;
	const int len = pattern->const_len;

	/* If @pattern doesn't contain pattern, I can use strcmp(). */
	if (!pattern->is_patterned)
		return !tomoyo_pathcmp(filename, pattern);
	/* Don't compare directory and non-directory. */
	if (filename->is_dir != pattern->is_dir)
		return false;
	/* Compare the initial length without patterns. */
	if (strncmp(f, p, len))
		return false;
	f += len;
	p += len;
	return tomoyo_path_matches_pattern2(f, p);
}

/**
 * tomoyo_get_exe - Get tomoyo_realpath() of current process.
 *
 * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
 *
 * This function uses kzalloc(), so the caller must call kfree()
 * if this function didn't return NULL.
 */
const char *tomoyo_get_exe(void)
{
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma;
	const char *cp = NULL;

	if (!mm)
		return NULL;
	down_read(&mm->mmap_sem);
	for (vma = mm->mmap; vma; vma = vma->vm_next) {
		if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
			cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
			break;
		}
	}
	up_read(&mm->mmap_sem);
	return cp;
}

/**
 * tomoyo_get_mode - Get MAC mode.
 *
 * @ns:      Pointer to "struct tomoyo_policy_namespace".
 * @profile: Profile number.
 * @index:   Index number of functionality.
 *
 * Returns mode.
 */
int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
		    const u8 index)
{
	u8 mode;
	struct tomoyo_profile *p;

	if (!tomoyo_policy_loaded)
		return TOMOYO_CONFIG_DISABLED;
	p = tomoyo_profile(ns, profile);
	mode = p->config[index];
	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
		mode = p->config[tomoyo_index2category[index]
				 + TOMOYO_MAX_MAC_INDEX];
	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
		mode = p->default_config;
	return mode & 3;
}

/**
 * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
 *
 * @r:      Pointer to "struct tomoyo_request_info" to initialize.
 * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
 * @index:  Index number of functionality.
 *
 * Returns mode.
 */
int tomoyo_init_request_info(struct tomoyo_request_info *r,
			     struct tomoyo_domain_info *domain, const u8 index)
{
	u8 profile;
	memset(r, 0, sizeof(*r));
	if (!domain)
		domain = tomoyo_domain();
	r->domain = domain;
	profile = domain->profile;
	r->profile = profile;
	r->type = index;
	r->mode = tomoyo_get_mode(domain->ns, profile, index);
	return r->mode;
}

/**
 * tomoyo_domain_quota_is_ok - Check for domain's quota.
 *
 * @r: Pointer to "struct tomoyo_request_info".
 *
 * Returns true if the domain is not exceeded quota, false otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
{
	unsigned int count = 0;
	struct tomoyo_domain_info *domain = r->domain;
	struct tomoyo_acl_info *ptr;

	if (r->mode != TOMOYO_CONFIG_LEARNING)
		return false;
	if (!domain)
		return true;
	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
		u16 perm;
		u8 i;
		if (ptr->is_deleted)
			continue;
		switch (ptr->type) {
		case TOMOYO_TYPE_PATH_ACL:
			perm = container_of(ptr, struct tomoyo_path_acl, head)
				->perm;
			break;
		case TOMOYO_TYPE_PATH2_ACL:
			perm = container_of(ptr, struct tomoyo_path2_acl, head)
				->perm;
			break;
		case TOMOYO_TYPE_PATH_NUMBER_ACL:
			perm = container_of(ptr, struct tomoyo_path_number_acl,
					    head)->perm;
			break;
		case TOMOYO_TYPE_MKDEV_ACL:
			perm = container_of(ptr, struct tomoyo_mkdev_acl,
					    head)->perm;
			break;
		default:
			perm = 1;
		}
		for (i = 0; i < 16; i++)
			if (perm & (1 << i))
				count++;
	}
	if (count < tomoyo_profile(domain->ns, domain->profile)->
	    pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
		return true;
	if (!domain->flags[TOMOYO_DIF_QUOTA_WARNED]) {
		domain->flags[TOMOYO_DIF_QUOTA_WARNED] = true;
		/* r->granted = false; */
		tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
		printk(KERN_WARNING "WARNING: "
		       "Domain '%s' has too many ACLs to hold. "
		       "Stopped learning mode.\n", domain->domainname->name);
	}
	return false;
}
OpenPOWER on IntegriCloud