Merge branch 'master' into next
[linux-3.10.git] / security / tomoyo / common.c
1 /*
2  * security/tomoyo/common.c
3  *
4  * Common functions for TOMOYO.
5  *
6  * Copyright (C) 2005-2009  NTT DATA CORPORATION
7  *
8  * Version: 2.2.0   2009/04/01
9  *
10  */
11
12 #include <linux/uaccess.h>
13 #include <linux/security.h>
14 #include <linux/hardirq.h>
15 #include "common.h"
16
17 /* Lock for protecting policy. */
18 DEFINE_MUTEX(tomoyo_policy_lock);
19
20 /* Has loading policy done? */
21 bool tomoyo_policy_loaded;
22
23 /* String table for functionality that takes 4 modes. */
24 static const char *tomoyo_mode_4[4] = {
25         "disabled", "learning", "permissive", "enforcing"
26 };
27 /* String table for functionality that takes 2 modes. */
28 static const char *tomoyo_mode_2[4] = {
29         "disabled", "enabled", "enabled", "enabled"
30 };
31
32 /*
33  * tomoyo_control_array is a static data which contains
34  *
35  *  (1) functionality name used by /sys/kernel/security/tomoyo/profile .
36  *  (2) initial values for "struct tomoyo_profile".
37  *  (3) max values for "struct tomoyo_profile".
38  */
39 static struct {
40         const char *keyword;
41         unsigned int current_value;
42         const unsigned int max_value;
43 } tomoyo_control_array[TOMOYO_MAX_CONTROL_INDEX] = {
44         [TOMOYO_MAC_FOR_FILE]     = { "MAC_FOR_FILE",        0,       3 },
45         [TOMOYO_MAX_ACCEPT_ENTRY] = { "MAX_ACCEPT_ENTRY", 2048, INT_MAX },
46         [TOMOYO_VERBOSE]          = { "TOMOYO_VERBOSE",      1,       1 },
47 };
48
49 /*
50  * tomoyo_profile is a structure which is used for holding the mode of access
51  * controls. TOMOYO has 4 modes: disabled, learning, permissive, enforcing.
52  * An administrator can define up to 256 profiles.
53  * The ->profile of "struct tomoyo_domain_info" is used for remembering
54  * the profile's number (0 - 255) assigned to that domain.
55  */
56 static struct tomoyo_profile {
57         unsigned int value[TOMOYO_MAX_CONTROL_INDEX];
58         const struct tomoyo_path_info *comment;
59 } *tomoyo_profile_ptr[TOMOYO_MAX_PROFILES];
60
61 /* Permit policy management by non-root user? */
62 static bool tomoyo_manage_by_non_root;
63
64 /* Utility functions. */
65
66 /* Open operation for /sys/kernel/security/tomoyo/ interface. */
67 static int tomoyo_open_control(const u8 type, struct file *file);
68 /* Close /sys/kernel/security/tomoyo/ interface. */
69 static int tomoyo_close_control(struct file *file);
70 /* Read operation for /sys/kernel/security/tomoyo/ interface. */
71 static int tomoyo_read_control(struct file *file, char __user *buffer,
72                                const int buffer_len);
73 /* Write operation for /sys/kernel/security/tomoyo/ interface. */
74 static int tomoyo_write_control(struct file *file, const char __user *buffer,
75                                 const int buffer_len);
76
77 /**
78  * tomoyo_is_byte_range - Check whether the string isa \ooo style octal value.
79  *
80  * @str: Pointer to the string.
81  *
82  * Returns true if @str is a \ooo style octal value, false otherwise.
83  *
84  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
85  * This function verifies that \ooo is in valid range.
86  */
87 static inline bool tomoyo_is_byte_range(const char *str)
88 {
89         return *str >= '0' && *str++ <= '3' &&
90                 *str >= '0' && *str++ <= '7' &&
91                 *str >= '0' && *str <= '7';
92 }
93
94 /**
95  * tomoyo_is_alphabet_char - Check whether the character is an alphabet.
96  *
97  * @c: The character to check.
98  *
99  * Returns true if @c is an alphabet character, false otherwise.
100  */
101 static inline bool tomoyo_is_alphabet_char(const char c)
102 {
103         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
104 }
105
106 /**
107  * tomoyo_make_byte - Make byte value from three octal characters.
108  *
109  * @c1: The first character.
110  * @c2: The second character.
111  * @c3: The third character.
112  *
113  * Returns byte value.
114  */
115 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
116 {
117         return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
118 }
119
120 /**
121  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
122  *
123  * @src:  Pointer to pointer to the string.
124  * @find: Pointer to the keyword.
125  *
126  * Returns true if @src starts with @find, false otherwise.
127  *
128  * The @src is updated to point the first character after the @find
129  * if @src starts with @find.
130  */
131 static bool tomoyo_str_starts(char **src, const char *find)
132 {
133         const int len = strlen(find);
134         char *tmp = *src;
135
136         if (strncmp(tmp, find, len))
137                 return false;
138         tmp += len;
139         *src = tmp;
140         return true;
141 }
142
143 /**
144  * tomoyo_normalize_line - Format string.
145  *
146  * @buffer: The line to normalize.
147  *
148  * Leading and trailing whitespaces are removed.
149  * Multiple whitespaces are packed into single space.
150  *
151  * Returns nothing.
152  */
153 static void tomoyo_normalize_line(unsigned char *buffer)
154 {
155         unsigned char *sp = buffer;
156         unsigned char *dp = buffer;
157         bool first = true;
158
159         while (tomoyo_is_invalid(*sp))
160                 sp++;
161         while (*sp) {
162                 if (!first)
163                         *dp++ = ' ';
164                 first = false;
165                 while (tomoyo_is_valid(*sp))
166                         *dp++ = *sp++;
167                 while (tomoyo_is_invalid(*sp))
168                         sp++;
169         }
170         *dp = '\0';
171 }
172
173 /**
174  * tomoyo_is_correct_path - Validate a pathname.
175  * @filename:     The pathname to check.
176  * @start_type:   Should the pathname start with '/'?
177  *                1 = must / -1 = must not / 0 = don't care
178  * @pattern_type: Can the pathname contain a wildcard?
179  *                1 = must / -1 = must not / 0 = don't care
180  * @end_type:     Should the pathname end with '/'?
181  *                1 = must / -1 = must not / 0 = don't care
182  *
183  * Check whether the given filename follows the naming rules.
184  * Returns true if @filename follows the naming rules, false otherwise.
185  */
186 bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
187                             const s8 pattern_type, const s8 end_type)
188 {
189         const char *const start = filename;
190         bool in_repetition = false;
191         bool contains_pattern = false;
192         unsigned char c;
193         unsigned char d;
194         unsigned char e;
195
196         if (!filename)
197                 goto out;
198         c = *filename;
199         if (start_type == 1) { /* Must start with '/' */
200                 if (c != '/')
201                         goto out;
202         } else if (start_type == -1) { /* Must not start with '/' */
203                 if (c == '/')
204                         goto out;
205         }
206         if (c)
207                 c = *(filename + strlen(filename) - 1);
208         if (end_type == 1) { /* Must end with '/' */
209                 if (c != '/')
210                         goto out;
211         } else if (end_type == -1) { /* Must not end with '/' */
212                 if (c == '/')
213                         goto out;
214         }
215         while (1) {
216                 c = *filename++;
217                 if (!c)
218                         break;
219                 if (c == '\\') {
220                         c = *filename++;
221                         switch (c) {
222                         case '\\':  /* "\\" */
223                                 continue;
224                         case '$':   /* "\$" */
225                         case '+':   /* "\+" */
226                         case '?':   /* "\?" */
227                         case '*':   /* "\*" */
228                         case '@':   /* "\@" */
229                         case 'x':   /* "\x" */
230                         case 'X':   /* "\X" */
231                         case 'a':   /* "\a" */
232                         case 'A':   /* "\A" */
233                         case '-':   /* "\-" */
234                                 if (pattern_type == -1)
235                                         break; /* Must not contain pattern */
236                                 contains_pattern = true;
237                                 continue;
238                         case '{':   /* "/\{" */
239                                 if (filename - 3 < start ||
240                                     *(filename - 3) != '/')
241                                         break;
242                                 if (pattern_type == -1)
243                                         break; /* Must not contain pattern */
244                                 contains_pattern = true;
245                                 in_repetition = true;
246                                 continue;
247                         case '}':   /* "\}/" */
248                                 if (*filename != '/')
249                                         break;
250                                 if (!in_repetition)
251                                         break;
252                                 in_repetition = false;
253                                 continue;
254                         case '0':   /* "\ooo" */
255                         case '1':
256                         case '2':
257                         case '3':
258                                 d = *filename++;
259                                 if (d < '0' || d > '7')
260                                         break;
261                                 e = *filename++;
262                                 if (e < '0' || e > '7')
263                                         break;
264                                 c = tomoyo_make_byte(c, d, e);
265                                 if (tomoyo_is_invalid(c))
266                                         continue; /* pattern is not \000 */
267                         }
268                         goto out;
269                 } else if (in_repetition && c == '/') {
270                         goto out;
271                 } else if (tomoyo_is_invalid(c)) {
272                         goto out;
273                 }
274         }
275         if (pattern_type == 1) { /* Must contain pattern */
276                 if (!contains_pattern)
277                         goto out;
278         }
279         if (in_repetition)
280                 goto out;
281         return true;
282  out:
283         return false;
284 }
285
286 /**
287  * tomoyo_is_correct_domain - Check whether the given domainname follows the naming rules.
288  * @domainname:   The domainname to check.
289  *
290  * Returns true if @domainname follows the naming rules, false otherwise.
291  */
292 bool tomoyo_is_correct_domain(const unsigned char *domainname)
293 {
294         unsigned char c;
295         unsigned char d;
296         unsigned char e;
297
298         if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME,
299                                    TOMOYO_ROOT_NAME_LEN))
300                 goto out;
301         domainname += TOMOYO_ROOT_NAME_LEN;
302         if (!*domainname)
303                 return true;
304         do {
305                 if (*domainname++ != ' ')
306                         goto out;
307                 if (*domainname++ != '/')
308                         goto out;
309                 while ((c = *domainname) != '\0' && c != ' ') {
310                         domainname++;
311                         if (c == '\\') {
312                                 c = *domainname++;
313                                 switch ((c)) {
314                                 case '\\':  /* "\\" */
315                                         continue;
316                                 case '0':   /* "\ooo" */
317                                 case '1':
318                                 case '2':
319                                 case '3':
320                                         d = *domainname++;
321                                         if (d < '0' || d > '7')
322                                                 break;
323                                         e = *domainname++;
324                                         if (e < '0' || e > '7')
325                                                 break;
326                                         c = tomoyo_make_byte(c, d, e);
327                                         if (tomoyo_is_invalid(c))
328                                                 /* pattern is not \000 */
329                                                 continue;
330                                 }
331                                 goto out;
332                         } else if (tomoyo_is_invalid(c)) {
333                                 goto out;
334                         }
335                 }
336         } while (*domainname);
337         return true;
338  out:
339         return false;
340 }
341
342 /**
343  * tomoyo_is_domain_def - Check whether the given token can be a domainname.
344  *
345  * @buffer: The token to check.
346  *
347  * Returns true if @buffer possibly be a domainname, false otherwise.
348  */
349 bool tomoyo_is_domain_def(const unsigned char *buffer)
350 {
351         return !strncmp(buffer, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN);
352 }
353
354 /**
355  * tomoyo_find_domain - Find a domain by the given name.
356  *
357  * @domainname: The domainname to find.
358  *
359  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
360  *
361  * Caller holds tomoyo_read_lock().
362  */
363 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
364 {
365         struct tomoyo_domain_info *domain;
366         struct tomoyo_path_info name;
367
368         name.name = domainname;
369         tomoyo_fill_path_info(&name);
370         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
371                 if (!domain->is_deleted &&
372                     !tomoyo_pathcmp(&name, domain->domainname))
373                         return domain;
374         }
375         return NULL;
376 }
377
378 /**
379  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
380  *
381  * @filename: The string to evaluate.
382  *
383  * Returns the initial length without a pattern in @filename.
384  */
385 static int tomoyo_const_part_length(const char *filename)
386 {
387         char c;
388         int len = 0;
389
390         if (!filename)
391                 return 0;
392         while ((c = *filename++) != '\0') {
393                 if (c != '\\') {
394                         len++;
395                         continue;
396                 }
397                 c = *filename++;
398                 switch (c) {
399                 case '\\':  /* "\\" */
400                         len += 2;
401                         continue;
402                 case '0':   /* "\ooo" */
403                 case '1':
404                 case '2':
405                 case '3':
406                         c = *filename++;
407                         if (c < '0' || c > '7')
408                                 break;
409                         c = *filename++;
410                         if (c < '0' || c > '7')
411                                 break;
412                         len += 4;
413                         continue;
414                 }
415                 break;
416         }
417         return len;
418 }
419
420 /**
421  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
422  *
423  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
424  *
425  * The caller sets "struct tomoyo_path_info"->name.
426  */
427 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
428 {
429         const char *name = ptr->name;
430         const int len = strlen(name);
431
432         ptr->const_len = tomoyo_const_part_length(name);
433         ptr->is_dir = len && (name[len - 1] == '/');
434         ptr->is_patterned = (ptr->const_len < len);
435         ptr->hash = full_name_hash(name, len);
436 }
437
438 /**
439  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character
440  * and "\-" pattern.
441  *
442  * @filename:     The start of string to check.
443  * @filename_end: The end of string to check.
444  * @pattern:      The start of pattern to compare.
445  * @pattern_end:  The end of pattern to compare.
446  *
447  * Returns true if @filename matches @pattern, false otherwise.
448  */
449 static bool tomoyo_file_matches_pattern2(const char *filename,
450                                          const char *filename_end,
451                                          const char *pattern,
452                                          const char *pattern_end)
453 {
454         while (filename < filename_end && pattern < pattern_end) {
455                 char c;
456                 if (*pattern != '\\') {
457                         if (*filename++ != *pattern++)
458                                 return false;
459                         continue;
460                 }
461                 c = *filename;
462                 pattern++;
463                 switch (*pattern) {
464                         int i;
465                         int j;
466                 case '?':
467                         if (c == '/') {
468                                 return false;
469                         } else if (c == '\\') {
470                                 if (filename[1] == '\\')
471                                         filename++;
472                                 else if (tomoyo_is_byte_range(filename + 1))
473                                         filename += 3;
474                                 else
475                                         return false;
476                         }
477                         break;
478                 case '\\':
479                         if (c != '\\')
480                                 return false;
481                         if (*++filename != '\\')
482                                 return false;
483                         break;
484                 case '+':
485                         if (!isdigit(c))
486                                 return false;
487                         break;
488                 case 'x':
489                         if (!isxdigit(c))
490                                 return false;
491                         break;
492                 case 'a':
493                         if (!tomoyo_is_alphabet_char(c))
494                                 return false;
495                         break;
496                 case '0':
497                 case '1':
498                 case '2':
499                 case '3':
500                         if (c == '\\' && tomoyo_is_byte_range(filename + 1)
501                             && strncmp(filename + 1, pattern, 3) == 0) {
502                                 filename += 3;
503                                 pattern += 2;
504                                 break;
505                         }
506                         return false; /* Not matched. */
507                 case '*':
508                 case '@':
509                         for (i = 0; i <= filename_end - filename; i++) {
510                                 if (tomoyo_file_matches_pattern2(
511                                                     filename + i, filename_end,
512                                                     pattern + 1, pattern_end))
513                                         return true;
514                                 c = filename[i];
515                                 if (c == '.' && *pattern == '@')
516                                         break;
517                                 if (c != '\\')
518                                         continue;
519                                 if (filename[i + 1] == '\\')
520                                         i++;
521                                 else if (tomoyo_is_byte_range(filename + i + 1))
522                                         i += 3;
523                                 else
524                                         break; /* Bad pattern. */
525                         }
526                         return false; /* Not matched. */
527                 default:
528                         j = 0;
529                         c = *pattern;
530                         if (c == '$') {
531                                 while (isdigit(filename[j]))
532                                         j++;
533                         } else if (c == 'X') {
534                                 while (isxdigit(filename[j]))
535                                         j++;
536                         } else if (c == 'A') {
537                                 while (tomoyo_is_alphabet_char(filename[j]))
538                                         j++;
539                         }
540                         for (i = 1; i <= j; i++) {
541                                 if (tomoyo_file_matches_pattern2(
542                                                     filename + i, filename_end,
543                                                     pattern + 1, pattern_end))
544                                         return true;
545                         }
546                         return false; /* Not matched or bad pattern. */
547                 }
548                 filename++;
549                 pattern++;
550         }
551         while (*pattern == '\\' &&
552                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
553                 pattern += 2;
554         return filename == filename_end && pattern == pattern_end;
555 }
556
557 /**
558  * tomoyo_file_matches_pattern - Pattern matching without without '/' character.
559  *
560  * @filename:     The start of string to check.
561  * @filename_end: The end of string to check.
562  * @pattern:      The start of pattern to compare.
563  * @pattern_end:  The end of pattern to compare.
564  *
565  * Returns true if @filename matches @pattern, false otherwise.
566  */
567 static bool tomoyo_file_matches_pattern(const char *filename,
568                                            const char *filename_end,
569                                            const char *pattern,
570                                            const char *pattern_end)
571 {
572         const char *pattern_start = pattern;
573         bool first = true;
574         bool result;
575
576         while (pattern < pattern_end - 1) {
577                 /* Split at "\-" pattern. */
578                 if (*pattern++ != '\\' || *pattern++ != '-')
579                         continue;
580                 result = tomoyo_file_matches_pattern2(filename,
581                                                       filename_end,
582                                                       pattern_start,
583                                                       pattern - 2);
584                 if (first)
585                         result = !result;
586                 if (result)
587                         return false;
588                 first = false;
589                 pattern_start = pattern;
590         }
591         result = tomoyo_file_matches_pattern2(filename, filename_end,
592                                               pattern_start, pattern_end);
593         return first ? result : !result;
594 }
595
596 /**
597  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
598  *
599  * @f: The start of string to check.
600  * @p: The start of pattern to compare.
601  *
602  * Returns true if @f matches @p, false otherwise.
603  */
604 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
605 {
606         const char *f_delimiter;
607         const char *p_delimiter;
608
609         while (*f && *p) {
610                 f_delimiter = strchr(f, '/');
611                 if (!f_delimiter)
612                         f_delimiter = f + strlen(f);
613                 p_delimiter = strchr(p, '/');
614                 if (!p_delimiter)
615                         p_delimiter = p + strlen(p);
616                 if (*p == '\\' && *(p + 1) == '{')
617                         goto recursive;
618                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
619                                                  p_delimiter))
620                         return false;
621                 f = f_delimiter;
622                 if (*f)
623                         f++;
624                 p = p_delimiter;
625                 if (*p)
626                         p++;
627         }
628         /* Ignore trailing "\*" and "\@" in @pattern. */
629         while (*p == '\\' &&
630                (*(p + 1) == '*' || *(p + 1) == '@'))
631                 p += 2;
632         return !*f && !*p;
633  recursive:
634         /*
635          * The "\{" pattern is permitted only after '/' character.
636          * This guarantees that below "*(p - 1)" is safe.
637          * Also, the "\}" pattern is permitted only before '/' character
638          * so that "\{" + "\}" pair will not break the "\-" operator.
639          */
640         if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
641             *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
642                 return false; /* Bad pattern. */
643         do {
644                 /* Compare current component with pattern. */
645                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
646                                                  p_delimiter - 2))
647                         break;
648                 /* Proceed to next component. */
649                 f = f_delimiter;
650                 if (!*f)
651                         break;
652                 f++;
653                 /* Continue comparison. */
654                 if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
655                         return true;
656                 f_delimiter = strchr(f, '/');
657         } while (f_delimiter);
658         return false; /* Not matched. */
659 }
660
661 /**
662  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
663  *
664  * @filename: The filename to check.
665  * @pattern:  The pattern to compare.
666  *
667  * Returns true if matches, false otherwise.
668  *
669  * The following patterns are available.
670  *   \\     \ itself.
671  *   \ooo   Octal representation of a byte.
672  *   \*     Zero or more repetitions of characters other than '/'.
673  *   \@     Zero or more repetitions of characters other than '/' or '.'.
674  *   \?     1 byte character other than '/'.
675  *   \$     One or more repetitions of decimal digits.
676  *   \+     1 decimal digit.
677  *   \X     One or more repetitions of hexadecimal digits.
678  *   \x     1 hexadecimal digit.
679  *   \A     One or more repetitions of alphabet characters.
680  *   \a     1 alphabet character.
681  *
682  *   \-     Subtraction operator.
683  *
684  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
685  *               /dir/dir/dir/ ).
686  */
687 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
688                                  const struct tomoyo_path_info *pattern)
689 {
690         const char *f = filename->name;
691         const char *p = pattern->name;
692         const int len = pattern->const_len;
693
694         /* If @pattern doesn't contain pattern, I can use strcmp(). */
695         if (!pattern->is_patterned)
696                 return !tomoyo_pathcmp(filename, pattern);
697         /* Don't compare directory and non-directory. */
698         if (filename->is_dir != pattern->is_dir)
699                 return false;
700         /* Compare the initial length without patterns. */
701         if (strncmp(f, p, len))
702                 return false;
703         f += len;
704         p += len;
705         return tomoyo_path_matches_pattern2(f, p);
706 }
707
708 /**
709  * tomoyo_io_printf - Transactional printf() to "struct tomoyo_io_buffer" structure.
710  *
711  * @head: Pointer to "struct tomoyo_io_buffer".
712  * @fmt:  The printf()'s format string, followed by parameters.
713  *
714  * Returns true if output was written, false otherwise.
715  *
716  * The snprintf() will truncate, but tomoyo_io_printf() won't.
717  */
718 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
719 {
720         va_list args;
721         int len;
722         int pos = head->read_avail;
723         int size = head->readbuf_size - pos;
724
725         if (size <= 0)
726                 return false;
727         va_start(args, fmt);
728         len = vsnprintf(head->read_buf + pos, size, fmt, args);
729         va_end(args);
730         if (pos + len >= head->readbuf_size)
731                 return false;
732         head->read_avail += len;
733         return true;
734 }
735
736 /**
737  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
738  *
739  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
740  *
741  * This function uses kzalloc(), so the caller must call kfree()
742  * if this function didn't return NULL.
743  */
744 static const char *tomoyo_get_exe(void)
745 {
746         struct mm_struct *mm = current->mm;
747         struct vm_area_struct *vma;
748         const char *cp = NULL;
749
750         if (!mm)
751                 return NULL;
752         down_read(&mm->mmap_sem);
753         for (vma = mm->mmap; vma; vma = vma->vm_next) {
754                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
755                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
756                         break;
757                 }
758         }
759         up_read(&mm->mmap_sem);
760         return cp;
761 }
762
763 /**
764  * tomoyo_get_msg - Get warning message.
765  *
766  * @is_enforce: Is it enforcing mode?
767  *
768  * Returns "ERROR" or "WARNING".
769  */
770 const char *tomoyo_get_msg(const bool is_enforce)
771 {
772         if (is_enforce)
773                 return "ERROR";
774         else
775                 return "WARNING";
776 }
777
778 /**
779  * tomoyo_check_flags - Check mode for specified functionality.
780  *
781  * @domain: Pointer to "struct tomoyo_domain_info".
782  * @index:  The functionality to check mode.
783  *
784  * TOMOYO checks only process context.
785  * This code disables TOMOYO's enforcement in case the function is called from
786  * interrupt context.
787  */
788 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
789                                 const u8 index)
790 {
791         const u8 profile = domain->profile;
792
793         if (WARN_ON(in_interrupt()))
794                 return 0;
795         return tomoyo_policy_loaded && index < TOMOYO_MAX_CONTROL_INDEX
796 #if TOMOYO_MAX_PROFILES != 256
797                 && profile < TOMOYO_MAX_PROFILES
798 #endif
799                 && tomoyo_profile_ptr[profile] ?
800                 tomoyo_profile_ptr[profile]->value[index] : 0;
801 }
802
803 /**
804  * tomoyo_verbose_mode - Check whether TOMOYO is verbose mode.
805  *
806  * @domain: Pointer to "struct tomoyo_domain_info".
807  *
808  * Returns true if domain policy violation warning should be printed to
809  * console.
810  */
811 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain)
812 {
813         return tomoyo_check_flags(domain, TOMOYO_VERBOSE) != 0;
814 }
815
816 /**
817  * tomoyo_domain_quota_is_ok - Check for domain's quota.
818  *
819  * @domain: Pointer to "struct tomoyo_domain_info".
820  *
821  * Returns true if the domain is not exceeded quota, false otherwise.
822  *
823  * Caller holds tomoyo_read_lock().
824  */
825 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
826 {
827         unsigned int count = 0;
828         struct tomoyo_acl_info *ptr;
829
830         if (!domain)
831                 return true;
832         list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
833                 switch (ptr->type) {
834                         struct tomoyo_path_acl *acl;
835                         u32 perm;
836                         u8 i;
837                 case TOMOYO_TYPE_PATH_ACL:
838                         acl = container_of(ptr, struct tomoyo_path_acl, head);
839                         perm = acl->perm | (((u32) acl->perm_high) << 16);
840                         for (i = 0; i < TOMOYO_MAX_PATH_OPERATION; i++)
841                                 if (perm & (1 << i))
842                                         count++;
843                         if (perm & (1 << TOMOYO_TYPE_READ_WRITE))
844                                 count -= 2;
845                         break;
846                 case TOMOYO_TYPE_PATH2_ACL:
847                         perm = container_of(ptr, struct tomoyo_path2_acl, head)
848                                 ->perm;
849                         for (i = 0; i < TOMOYO_MAX_PATH2_OPERATION; i++)
850                                 if (perm & (1 << i))
851                                         count++;
852                         break;
853                 }
854         }
855         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
856                 return true;
857         if (!domain->quota_warned) {
858                 domain->quota_warned = true;
859                 printk(KERN_WARNING "TOMOYO-WARNING: "
860                        "Domain '%s' has so many ACLs to hold. "
861                        "Stopped learning mode.\n", domain->domainname->name);
862         }
863         return false;
864 }
865
866 /**
867  * tomoyo_find_or_assign_new_profile - Create a new profile.
868  *
869  * @profile: Profile number to create.
870  *
871  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
872  */
873 static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned
874                                                                 int profile)
875 {
876         static DEFINE_MUTEX(lock);
877         struct tomoyo_profile *ptr = NULL;
878         int i;
879
880         if (profile >= TOMOYO_MAX_PROFILES)
881                 return NULL;
882         mutex_lock(&lock);
883         ptr = tomoyo_profile_ptr[profile];
884         if (ptr)
885                 goto ok;
886         ptr = kmalloc(sizeof(*ptr), GFP_KERNEL);
887         if (!tomoyo_memory_ok(ptr)) {
888                 kfree(ptr);
889                 ptr = NULL;
890                 goto ok;
891         }
892         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
893                 ptr->value[i] = tomoyo_control_array[i].current_value;
894         mb(); /* Avoid out-of-order execution. */
895         tomoyo_profile_ptr[profile] = ptr;
896  ok:
897         mutex_unlock(&lock);
898         return ptr;
899 }
900
901 /**
902  * tomoyo_write_profile - Write to profile table.
903  *
904  * @head: Pointer to "struct tomoyo_io_buffer".
905  *
906  * Returns 0 on success, negative value otherwise.
907  */
908 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
909 {
910         char *data = head->write_buf;
911         unsigned int i;
912         unsigned int value;
913         char *cp;
914         struct tomoyo_profile *profile;
915         unsigned long num;
916
917         cp = strchr(data, '-');
918         if (cp)
919                 *cp = '\0';
920         if (strict_strtoul(data, 10, &num))
921                 return -EINVAL;
922         if (cp)
923                 data = cp + 1;
924         profile = tomoyo_find_or_assign_new_profile(num);
925         if (!profile)
926                 return -EINVAL;
927         cp = strchr(data, '=');
928         if (!cp)
929                 return -EINVAL;
930         *cp = '\0';
931         if (!strcmp(data, "COMMENT")) {
932                 const struct tomoyo_path_info *old_comment = profile->comment;
933                 profile->comment = tomoyo_get_name(cp + 1);
934                 tomoyo_put_name(old_comment);
935                 return 0;
936         }
937         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
938                 if (strcmp(data, tomoyo_control_array[i].keyword))
939                         continue;
940                 if (sscanf(cp + 1, "%u", &value) != 1) {
941                         int j;
942                         const char **modes;
943                         switch (i) {
944                         case TOMOYO_VERBOSE:
945                                 modes = tomoyo_mode_2;
946                                 break;
947                         default:
948                                 modes = tomoyo_mode_4;
949                                 break;
950                         }
951                         for (j = 0; j < 4; j++) {
952                                 if (strcmp(cp + 1, modes[j]))
953                                         continue;
954                                 value = j;
955                                 break;
956                         }
957                         if (j == 4)
958                                 return -EINVAL;
959                 } else if (value > tomoyo_control_array[i].max_value) {
960                         value = tomoyo_control_array[i].max_value;
961                 }
962                 profile->value[i] = value;
963                 return 0;
964         }
965         return -EINVAL;
966 }
967
968 /**
969  * tomoyo_read_profile - Read from profile table.
970  *
971  * @head: Pointer to "struct tomoyo_io_buffer".
972  *
973  * Returns 0.
974  */
975 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
976 {
977         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
978         int step;
979
980         if (head->read_eof)
981                 return 0;
982         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
983              step++) {
984                 const u8 index = step / total;
985                 u8 type = step % total;
986                 const struct tomoyo_profile *profile
987                         = tomoyo_profile_ptr[index];
988                 head->read_step = step;
989                 if (!profile)
990                         continue;
991                 if (!type) { /* Print profile' comment tag. */
992                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
993                                               index, profile->comment ?
994                                               profile->comment->name : ""))
995                                 break;
996                         continue;
997                 }
998                 type--;
999                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
1000                         const unsigned int value = profile->value[type];
1001                         const char **modes = NULL;
1002                         const char *keyword
1003                                 = tomoyo_control_array[type].keyword;
1004                         switch (tomoyo_control_array[type].max_value) {
1005                         case 3:
1006                                 modes = tomoyo_mode_4;
1007                                 break;
1008                         case 1:
1009                                 modes = tomoyo_mode_2;
1010                                 break;
1011                         }
1012                         if (modes) {
1013                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
1014                                                       keyword, modes[value]))
1015                                         break;
1016                         } else {
1017                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1018                                                       keyword, value))
1019                                         break;
1020                         }
1021                 }
1022         }
1023         if (step == TOMOYO_MAX_PROFILES * total)
1024                 head->read_eof = true;
1025         return 0;
1026 }
1027
1028 /*
1029  * tomoyo_policy_manager_list is used for holding list of domainnames or
1030  * programs which are permitted to modify configuration via
1031  * /sys/kernel/security/tomoyo/ interface.
1032  *
1033  * An entry is added by
1034  *
1035  * # echo '<kernel> /sbin/mingetty /bin/login /bin/bash' > \
1036  *                                        /sys/kernel/security/tomoyo/manager
1037  *  (if you want to specify by a domainname)
1038  *
1039  *  or
1040  *
1041  * # echo '/usr/lib/ccs/editpolicy' > /sys/kernel/security/tomoyo/manager
1042  *  (if you want to specify by a program's location)
1043  *
1044  * and is deleted by
1045  *
1046  * # echo 'delete <kernel> /sbin/mingetty /bin/login /bin/bash' > \
1047  *                                        /sys/kernel/security/tomoyo/manager
1048  *
1049  *  or
1050  *
1051  * # echo 'delete /usr/lib/ccs/editpolicy' > \
1052  *                                        /sys/kernel/security/tomoyo/manager
1053  *
1054  * and all entries are retrieved by
1055  *
1056  * # cat /sys/kernel/security/tomoyo/manager
1057  */
1058 LIST_HEAD(tomoyo_policy_manager_list);
1059
1060 /**
1061  * tomoyo_update_manager_entry - Add a manager entry.
1062  *
1063  * @manager:   The path to manager or the domainnamme.
1064  * @is_delete: True if it is a delete request.
1065  *
1066  * Returns 0 on success, negative value otherwise.
1067  *
1068  * Caller holds tomoyo_read_lock().
1069  */
1070 static int tomoyo_update_manager_entry(const char *manager,
1071                                        const bool is_delete)
1072 {
1073         struct tomoyo_policy_manager_entry *entry = NULL;
1074         struct tomoyo_policy_manager_entry *ptr;
1075         const struct tomoyo_path_info *saved_manager;
1076         int error = is_delete ? -ENOENT : -ENOMEM;
1077         bool is_domain = false;
1078
1079         if (tomoyo_is_domain_def(manager)) {
1080                 if (!tomoyo_is_correct_domain(manager))
1081                         return -EINVAL;
1082                 is_domain = true;
1083         } else {
1084                 if (!tomoyo_is_correct_path(manager, 1, -1, -1))
1085                         return -EINVAL;
1086         }
1087         saved_manager = tomoyo_get_name(manager);
1088         if (!saved_manager)
1089                 return -ENOMEM;
1090         if (!is_delete)
1091                 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1092         mutex_lock(&tomoyo_policy_lock);
1093         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1094                 if (ptr->manager != saved_manager)
1095                         continue;
1096                 ptr->is_deleted = is_delete;
1097                 error = 0;
1098                 break;
1099         }
1100         if (!is_delete && error && tomoyo_memory_ok(entry)) {
1101                 entry->manager = saved_manager;
1102                 saved_manager = NULL;
1103                 entry->is_domain = is_domain;
1104                 list_add_tail_rcu(&entry->list, &tomoyo_policy_manager_list);
1105                 entry = NULL;
1106                 error = 0;
1107         }
1108         mutex_unlock(&tomoyo_policy_lock);
1109         tomoyo_put_name(saved_manager);
1110         kfree(entry);
1111         return error;
1112 }
1113
1114 /**
1115  * tomoyo_write_manager_policy - Write manager policy.
1116  *
1117  * @head: Pointer to "struct tomoyo_io_buffer".
1118  *
1119  * Returns 0 on success, negative value otherwise.
1120  *
1121  * Caller holds tomoyo_read_lock().
1122  */
1123 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1124 {
1125         char *data = head->write_buf;
1126         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1127
1128         if (!strcmp(data, "manage_by_non_root")) {
1129                 tomoyo_manage_by_non_root = !is_delete;
1130                 return 0;
1131         }
1132         return tomoyo_update_manager_entry(data, is_delete);
1133 }
1134
1135 /**
1136  * tomoyo_read_manager_policy - Read manager policy.
1137  *
1138  * @head: Pointer to "struct tomoyo_io_buffer".
1139  *
1140  * Returns 0.
1141  *
1142  * Caller holds tomoyo_read_lock().
1143  */
1144 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1145 {
1146         struct list_head *pos;
1147         bool done = true;
1148
1149         if (head->read_eof)
1150                 return 0;
1151         list_for_each_cookie(pos, head->read_var2,
1152                              &tomoyo_policy_manager_list) {
1153                 struct tomoyo_policy_manager_entry *ptr;
1154                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1155                                  list);
1156                 if (ptr->is_deleted)
1157                         continue;
1158                 done = tomoyo_io_printf(head, "%s\n", ptr->manager->name);
1159                 if (!done)
1160                         break;
1161         }
1162         head->read_eof = done;
1163         return 0;
1164 }
1165
1166 /**
1167  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1168  *
1169  * Returns true if the current process is permitted to modify policy
1170  * via /sys/kernel/security/tomoyo/ interface.
1171  *
1172  * Caller holds tomoyo_read_lock().
1173  */
1174 static bool tomoyo_is_policy_manager(void)
1175 {
1176         struct tomoyo_policy_manager_entry *ptr;
1177         const char *exe;
1178         const struct task_struct *task = current;
1179         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1180         bool found = false;
1181
1182         if (!tomoyo_policy_loaded)
1183                 return true;
1184         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1185                 return false;
1186         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1187                 if (!ptr->is_deleted && ptr->is_domain
1188                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1189                         found = true;
1190                         break;
1191                 }
1192         }
1193         if (found)
1194                 return true;
1195         exe = tomoyo_get_exe();
1196         if (!exe)
1197                 return false;
1198         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1199                 if (!ptr->is_deleted && !ptr->is_domain
1200                     && !strcmp(exe, ptr->manager->name)) {
1201                         found = true;
1202                         break;
1203                 }
1204         }
1205         if (!found) { /* Reduce error messages. */
1206                 static pid_t last_pid;
1207                 const pid_t pid = current->pid;
1208                 if (last_pid != pid) {
1209                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1210                                "update policies.\n", domainname->name, exe);
1211                         last_pid = pid;
1212                 }
1213         }
1214         kfree(exe);
1215         return found;
1216 }
1217
1218 /**
1219  * tomoyo_is_select_one - Parse select command.
1220  *
1221  * @head: Pointer to "struct tomoyo_io_buffer".
1222  * @data: String to parse.
1223  *
1224  * Returns true on success, false otherwise.
1225  *
1226  * Caller holds tomoyo_read_lock().
1227  */
1228 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1229                                  const char *data)
1230 {
1231         unsigned int pid;
1232         struct tomoyo_domain_info *domain = NULL;
1233
1234         if (sscanf(data, "pid=%u", &pid) == 1) {
1235                 struct task_struct *p;
1236                 rcu_read_lock();
1237                 read_lock(&tasklist_lock);
1238                 p = find_task_by_vpid(pid);
1239                 if (p)
1240                         domain = tomoyo_real_domain(p);
1241                 read_unlock(&tasklist_lock);
1242                 rcu_read_unlock();
1243         } else if (!strncmp(data, "domain=", 7)) {
1244                 if (tomoyo_is_domain_def(data + 7))
1245                         domain = tomoyo_find_domain(data + 7);
1246         } else
1247                 return false;
1248         head->write_var1 = domain;
1249         /* Accessing read_buf is safe because head->io_sem is held. */
1250         if (!head->read_buf)
1251                 return true; /* Do nothing if open(O_WRONLY). */
1252         head->read_avail = 0;
1253         tomoyo_io_printf(head, "# select %s\n", data);
1254         head->read_single_domain = true;
1255         head->read_eof = !domain;
1256         if (domain) {
1257                 struct tomoyo_domain_info *d;
1258                 head->read_var1 = NULL;
1259                 list_for_each_entry_rcu(d, &tomoyo_domain_list, list) {
1260                         if (d == domain)
1261                                 break;
1262                         head->read_var1 = &d->list;
1263                 }
1264                 head->read_var2 = NULL;
1265                 head->read_bit = 0;
1266                 head->read_step = 0;
1267                 if (domain->is_deleted)
1268                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1269         }
1270         return true;
1271 }
1272
1273 /**
1274  * tomoyo_delete_domain - Delete a domain.
1275  *
1276  * @domainname: The name of domain.
1277  *
1278  * Returns 0.
1279  *
1280  * Caller holds tomoyo_read_lock().
1281  */
1282 static int tomoyo_delete_domain(char *domainname)
1283 {
1284         struct tomoyo_domain_info *domain;
1285         struct tomoyo_path_info name;
1286
1287         name.name = domainname;
1288         tomoyo_fill_path_info(&name);
1289         mutex_lock(&tomoyo_policy_lock);
1290         /* Is there an active domain? */
1291         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1292                 /* Never delete tomoyo_kernel_domain */
1293                 if (domain == &tomoyo_kernel_domain)
1294                         continue;
1295                 if (domain->is_deleted ||
1296                     tomoyo_pathcmp(domain->domainname, &name))
1297                         continue;
1298                 domain->is_deleted = true;
1299                 break;
1300         }
1301         mutex_unlock(&tomoyo_policy_lock);
1302         return 0;
1303 }
1304
1305 /**
1306  * tomoyo_write_domain_policy - Write domain policy.
1307  *
1308  * @head: Pointer to "struct tomoyo_io_buffer".
1309  *
1310  * Returns 0 on success, negative value otherwise.
1311  *
1312  * Caller holds tomoyo_read_lock().
1313  */
1314 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1315 {
1316         char *data = head->write_buf;
1317         struct tomoyo_domain_info *domain = head->write_var1;
1318         bool is_delete = false;
1319         bool is_select = false;
1320         unsigned int profile;
1321
1322         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1323                 is_delete = true;
1324         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1325                 is_select = true;
1326         if (is_select && tomoyo_is_select_one(head, data))
1327                 return 0;
1328         /* Don't allow updating policies by non manager programs. */
1329         if (!tomoyo_is_policy_manager())
1330                 return -EPERM;
1331         if (tomoyo_is_domain_def(data)) {
1332                 domain = NULL;
1333                 if (is_delete)
1334                         tomoyo_delete_domain(data);
1335                 else if (is_select)
1336                         domain = tomoyo_find_domain(data);
1337                 else
1338                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1339                 head->write_var1 = domain;
1340                 return 0;
1341         }
1342         if (!domain)
1343                 return -EINVAL;
1344
1345         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1346             && profile < TOMOYO_MAX_PROFILES) {
1347                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1348                         domain->profile = (u8) profile;
1349                 return 0;
1350         }
1351         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1352                 domain->ignore_global_allow_read = !is_delete;
1353                 return 0;
1354         }
1355         return tomoyo_write_file_policy(data, domain, is_delete);
1356 }
1357
1358 /**
1359  * tomoyo_print_path_acl - Print a single path ACL entry.
1360  *
1361  * @head: Pointer to "struct tomoyo_io_buffer".
1362  * @ptr:  Pointer to "struct tomoyo_path_acl".
1363  *
1364  * Returns true on success, false otherwise.
1365  */
1366 static bool tomoyo_print_path_acl(struct tomoyo_io_buffer *head,
1367                                   struct tomoyo_path_acl *ptr)
1368 {
1369         int pos;
1370         u8 bit;
1371         const char *filename;
1372         const u32 perm = ptr->perm | (((u32) ptr->perm_high) << 16);
1373
1374         filename = ptr->filename->name;
1375         for (bit = head->read_bit; bit < TOMOYO_MAX_PATH_OPERATION; bit++) {
1376                 const char *msg;
1377                 if (!(perm & (1 << bit)))
1378                         continue;
1379                 /* Print "read/write" instead of "read" and "write". */
1380                 if ((bit == TOMOYO_TYPE_READ || bit == TOMOYO_TYPE_WRITE)
1381                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE)))
1382                         continue;
1383                 msg = tomoyo_path2keyword(bit);
1384                 pos = head->read_avail;
1385                 if (!tomoyo_io_printf(head, "allow_%s %s\n", msg, filename))
1386                         goto out;
1387         }
1388         head->read_bit = 0;
1389         return true;
1390  out:
1391         head->read_bit = bit;
1392         head->read_avail = pos;
1393         return false;
1394 }
1395
1396 /**
1397  * tomoyo_print_path2_acl - Print a double path ACL entry.
1398  *
1399  * @head: Pointer to "struct tomoyo_io_buffer".
1400  * @ptr:  Pointer to "struct tomoyo_path2_acl".
1401  *
1402  * Returns true on success, false otherwise.
1403  */
1404 static bool tomoyo_print_path2_acl(struct tomoyo_io_buffer *head,
1405                                    struct tomoyo_path2_acl *ptr)
1406 {
1407         int pos;
1408         const char *filename1;
1409         const char *filename2;
1410         const u8 perm = ptr->perm;
1411         u8 bit;
1412
1413         filename1 = ptr->filename1->name;
1414         filename2 = ptr->filename2->name;
1415         for (bit = head->read_bit; bit < TOMOYO_MAX_PATH2_OPERATION; bit++) {
1416                 const char *msg;
1417                 if (!(perm & (1 << bit)))
1418                         continue;
1419                 msg = tomoyo_path22keyword(bit);
1420                 pos = head->read_avail;
1421                 if (!tomoyo_io_printf(head, "allow_%s %s %s\n", msg,
1422                                       filename1, filename2))
1423                         goto out;
1424         }
1425         head->read_bit = 0;
1426         return true;
1427  out:
1428         head->read_bit = bit;
1429         head->read_avail = pos;
1430         return false;
1431 }
1432
1433 /**
1434  * tomoyo_print_entry - Print an ACL entry.
1435  *
1436  * @head: Pointer to "struct tomoyo_io_buffer".
1437  * @ptr:  Pointer to an ACL entry.
1438  *
1439  * Returns true on success, false otherwise.
1440  */
1441 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1442                                struct tomoyo_acl_info *ptr)
1443 {
1444         const u8 acl_type = ptr->type;
1445
1446         if (acl_type == TOMOYO_TYPE_PATH_ACL) {
1447                 struct tomoyo_path_acl *acl
1448                         = container_of(ptr, struct tomoyo_path_acl, head);
1449                 return tomoyo_print_path_acl(head, acl);
1450         }
1451         if (acl_type == TOMOYO_TYPE_PATH2_ACL) {
1452                 struct tomoyo_path2_acl *acl
1453                         = container_of(ptr, struct tomoyo_path2_acl, head);
1454                 return tomoyo_print_path2_acl(head, acl);
1455         }
1456         BUG(); /* This must not happen. */
1457         return false;
1458 }
1459
1460 /**
1461  * tomoyo_read_domain_policy - Read domain policy.
1462  *
1463  * @head: Pointer to "struct tomoyo_io_buffer".
1464  *
1465  * Returns 0.
1466  *
1467  * Caller holds tomoyo_read_lock().
1468  */
1469 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1470 {
1471         struct list_head *dpos;
1472         struct list_head *apos;
1473         bool done = true;
1474
1475         if (head->read_eof)
1476                 return 0;
1477         if (head->read_step == 0)
1478                 head->read_step = 1;
1479         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1480                 struct tomoyo_domain_info *domain;
1481                 const char *quota_exceeded = "";
1482                 const char *transition_failed = "";
1483                 const char *ignore_global_allow_read = "";
1484                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1485                 if (head->read_step != 1)
1486                         goto acl_loop;
1487                 if (domain->is_deleted && !head->read_single_domain)
1488                         continue;
1489                 /* Print domainname and flags. */
1490                 if (domain->quota_warned)
1491                         quota_exceeded = "quota_exceeded\n";
1492                 if (domain->transition_failed)
1493                         transition_failed = "transition_failed\n";
1494                 if (domain->ignore_global_allow_read)
1495                         ignore_global_allow_read
1496                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1497                 done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
1498                                         "%u\n%s%s%s\n",
1499                                         domain->domainname->name,
1500                                         domain->profile, quota_exceeded,
1501                                         transition_failed,
1502                                         ignore_global_allow_read);
1503                 if (!done)
1504                         break;
1505                 head->read_step = 2;
1506 acl_loop:
1507                 if (head->read_step == 3)
1508                         goto tail_mark;
1509                 /* Print ACL entries in the domain. */
1510                 list_for_each_cookie(apos, head->read_var2,
1511                                      &domain->acl_info_list) {
1512                         struct tomoyo_acl_info *ptr
1513                                 = list_entry(apos, struct tomoyo_acl_info,
1514                                              list);
1515                         done = tomoyo_print_entry(head, ptr);
1516                         if (!done)
1517                                 break;
1518                 }
1519                 if (!done)
1520                         break;
1521                 head->read_step = 3;
1522 tail_mark:
1523                 done = tomoyo_io_printf(head, "\n");
1524                 if (!done)
1525                         break;
1526                 head->read_step = 1;
1527                 if (head->read_single_domain)
1528                         break;
1529         }
1530         head->read_eof = done;
1531         return 0;
1532 }
1533
1534 /**
1535  * tomoyo_write_domain_profile - Assign profile for specified domain.
1536  *
1537  * @head: Pointer to "struct tomoyo_io_buffer".
1538  *
1539  * Returns 0 on success, -EINVAL otherwise.
1540  *
1541  * This is equivalent to doing
1542  *
1543  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1544  *     /usr/lib/ccs/loadpolicy -d
1545  *
1546  * Caller holds tomoyo_read_lock().
1547  */
1548 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1549 {
1550         char *data = head->write_buf;
1551         char *cp = strchr(data, ' ');
1552         struct tomoyo_domain_info *domain;
1553         unsigned long profile;
1554
1555         if (!cp)
1556                 return -EINVAL;
1557         *cp = '\0';
1558         domain = tomoyo_find_domain(cp + 1);
1559         if (strict_strtoul(data, 10, &profile))
1560                 return -EINVAL;
1561         if (domain && profile < TOMOYO_MAX_PROFILES
1562             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1563                 domain->profile = (u8) profile;
1564         return 0;
1565 }
1566
1567 /**
1568  * tomoyo_read_domain_profile - Read only domainname and profile.
1569  *
1570  * @head: Pointer to "struct tomoyo_io_buffer".
1571  *
1572  * Returns list of profile number and domainname pairs.
1573  *
1574  * This is equivalent to doing
1575  *
1576  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1577  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1578  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1579  *     print $2 " " domainname; domainname = ""; } } ; '
1580  *
1581  * Caller holds tomoyo_read_lock().
1582  */
1583 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1584 {
1585         struct list_head *pos;
1586         bool done = true;
1587
1588         if (head->read_eof)
1589                 return 0;
1590         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1591                 struct tomoyo_domain_info *domain;
1592                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1593                 if (domain->is_deleted)
1594                         continue;
1595                 done = tomoyo_io_printf(head, "%u %s\n", domain->profile,
1596                                         domain->domainname->name);
1597                 if (!done)
1598                         break;
1599         }
1600         head->read_eof = done;
1601         return 0;
1602 }
1603
1604 /**
1605  * tomoyo_write_pid: Specify PID to obtain domainname.
1606  *
1607  * @head: Pointer to "struct tomoyo_io_buffer".
1608  *
1609  * Returns 0.
1610  */
1611 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1612 {
1613         unsigned long pid;
1614         /* No error check. */
1615         strict_strtoul(head->write_buf, 10, &pid);
1616         head->read_step = (int) pid;
1617         head->read_eof = false;
1618         return 0;
1619 }
1620
1621 /**
1622  * tomoyo_read_pid - Get domainname of the specified PID.
1623  *
1624  * @head: Pointer to "struct tomoyo_io_buffer".
1625  *
1626  * Returns the domainname which the specified PID is in on success,
1627  * empty string otherwise.
1628  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1629  * using read()/write() interface rather than sysctl() interface.
1630  */
1631 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1632 {
1633         if (head->read_avail == 0 && !head->read_eof) {
1634                 const int pid = head->read_step;
1635                 struct task_struct *p;
1636                 struct tomoyo_domain_info *domain = NULL;
1637                 rcu_read_lock();
1638                 read_lock(&tasklist_lock);
1639                 p = find_task_by_vpid(pid);
1640                 if (p)
1641                         domain = tomoyo_real_domain(p);
1642                 read_unlock(&tasklist_lock);
1643                 rcu_read_unlock();
1644                 if (domain)
1645                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1646                                          domain->domainname->name);
1647                 head->read_eof = true;
1648         }
1649         return 0;
1650 }
1651
1652 /**
1653  * tomoyo_write_exception_policy - Write exception policy.
1654  *
1655  * @head: Pointer to "struct tomoyo_io_buffer".
1656  *
1657  * Returns 0 on success, negative value otherwise.
1658  *
1659  * Caller holds tomoyo_read_lock().
1660  */
1661 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1662 {
1663         char *data = head->write_buf;
1664         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1665
1666         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1667                 return tomoyo_write_domain_keeper_policy(data, false,
1668                                                          is_delete);
1669         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1670                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1671         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1672                 return tomoyo_write_domain_initializer_policy(data, false,
1673                                                               is_delete);
1674         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1675                 return tomoyo_write_domain_initializer_policy(data, true,
1676                                                               is_delete);
1677         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1678                 return tomoyo_write_alias_policy(data, is_delete);
1679         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1680                 return tomoyo_write_globally_readable_policy(data, is_delete);
1681         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1682                 return tomoyo_write_pattern_policy(data, is_delete);
1683         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1684                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1685         return -EINVAL;
1686 }
1687
1688 /**
1689  * tomoyo_read_exception_policy - Read exception policy.
1690  *
1691  * @head: Pointer to "struct tomoyo_io_buffer".
1692  *
1693  * Returns 0 on success, -EINVAL otherwise.
1694  *
1695  * Caller holds tomoyo_read_lock().
1696  */
1697 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1698 {
1699         if (!head->read_eof) {
1700                 switch (head->read_step) {
1701                 case 0:
1702                         head->read_var2 = NULL;
1703                         head->read_step = 1;
1704                 case 1:
1705                         if (!tomoyo_read_domain_keeper_policy(head))
1706                                 break;
1707                         head->read_var2 = NULL;
1708                         head->read_step = 2;
1709                 case 2:
1710                         if (!tomoyo_read_globally_readable_policy(head))
1711                                 break;
1712                         head->read_var2 = NULL;
1713                         head->read_step = 3;
1714                 case 3:
1715                         head->read_var2 = NULL;
1716                         head->read_step = 4;
1717                 case 4:
1718                         if (!tomoyo_read_domain_initializer_policy(head))
1719                                 break;
1720                         head->read_var2 = NULL;
1721                         head->read_step = 5;
1722                 case 5:
1723                         if (!tomoyo_read_alias_policy(head))
1724                                 break;
1725                         head->read_var2 = NULL;
1726                         head->read_step = 6;
1727                 case 6:
1728                         head->read_var2 = NULL;
1729                         head->read_step = 7;
1730                 case 7:
1731                         if (!tomoyo_read_file_pattern(head))
1732                                 break;
1733                         head->read_var2 = NULL;
1734                         head->read_step = 8;
1735                 case 8:
1736                         if (!tomoyo_read_no_rewrite_policy(head))
1737                                 break;
1738                         head->read_var2 = NULL;
1739                         head->read_step = 9;
1740                 case 9:
1741                         head->read_eof = true;
1742                         break;
1743                 default:
1744                         return -EINVAL;
1745                 }
1746         }
1747         return 0;
1748 }
1749
1750 /* path to policy loader */
1751 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1752
1753 /**
1754  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1755  *
1756  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1757  */
1758 static bool tomoyo_policy_loader_exists(void)
1759 {
1760         /*
1761          * Don't activate MAC if the policy loader doesn't exist.
1762          * If the initrd includes /sbin/init but real-root-dev has not
1763          * mounted on / yet, activating MAC will block the system since
1764          * policies are not loaded yet.
1765          * Thus, let do_execve() call this function everytime.
1766          */
1767         struct path path;
1768
1769         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
1770                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1771                        "since %s doesn't exist.\n", tomoyo_loader);
1772                 return false;
1773         }
1774         path_put(&path);
1775         return true;
1776 }
1777
1778 /**
1779  * tomoyo_load_policy - Run external policy loader to load policy.
1780  *
1781  * @filename: The program about to start.
1782  *
1783  * This function checks whether @filename is /sbin/init , and if so
1784  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1785  * and then continues invocation of /sbin/init.
1786  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1787  * writes to /sys/kernel/security/tomoyo/ interfaces.
1788  *
1789  * Returns nothing.
1790  */
1791 void tomoyo_load_policy(const char *filename)
1792 {
1793         char *argv[2];
1794         char *envp[3];
1795
1796         if (tomoyo_policy_loaded)
1797                 return;
1798         /*
1799          * Check filename is /sbin/init or /sbin/tomoyo-start.
1800          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1801          * be passed.
1802          * You can create /sbin/tomoyo-start by
1803          * "ln -s /bin/true /sbin/tomoyo-start".
1804          */
1805         if (strcmp(filename, "/sbin/init") &&
1806             strcmp(filename, "/sbin/tomoyo-start"))
1807                 return;
1808         if (!tomoyo_policy_loader_exists())
1809                 return;
1810
1811         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1812                tomoyo_loader);
1813         argv[0] = (char *) tomoyo_loader;
1814         argv[1] = NULL;
1815         envp[0] = "HOME=/";
1816         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1817         envp[2] = NULL;
1818         call_usermodehelper(argv[0], argv, envp, 1);
1819
1820         printk(KERN_INFO "TOMOYO: 2.2.0   2009/04/01\n");
1821         printk(KERN_INFO "Mandatory Access Control activated.\n");
1822         tomoyo_policy_loaded = true;
1823         { /* Check all profiles currently assigned to domains are defined. */
1824                 struct tomoyo_domain_info *domain;
1825                 list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1826                         const u8 profile = domain->profile;
1827                         if (tomoyo_profile_ptr[profile])
1828                                 continue;
1829                         panic("Profile %u (used by '%s') not defined.\n",
1830                               profile, domain->domainname->name);
1831                 }
1832         }
1833 }
1834
1835 /**
1836  * tomoyo_read_version: Get version.
1837  *
1838  * @head: Pointer to "struct tomoyo_io_buffer".
1839  *
1840  * Returns version information.
1841  */
1842 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1843 {
1844         if (!head->read_eof) {
1845                 tomoyo_io_printf(head, "2.2.0");
1846                 head->read_eof = true;
1847         }
1848         return 0;
1849 }
1850
1851 /**
1852  * tomoyo_read_self_domain - Get the current process's domainname.
1853  *
1854  * @head: Pointer to "struct tomoyo_io_buffer".
1855  *
1856  * Returns the current process's domainname.
1857  */
1858 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1859 {
1860         if (!head->read_eof) {
1861                 /*
1862                  * tomoyo_domain()->domainname != NULL
1863                  * because every process belongs to a domain and
1864                  * the domain's name cannot be NULL.
1865                  */
1866                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1867                 head->read_eof = true;
1868         }
1869         return 0;
1870 }
1871
1872 /**
1873  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1874  *
1875  * @type: Type of interface.
1876  * @file: Pointer to "struct file".
1877  *
1878  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1879  *
1880  * Caller acquires tomoyo_read_lock().
1881  */
1882 static int tomoyo_open_control(const u8 type, struct file *file)
1883 {
1884         struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_KERNEL);
1885
1886         if (!head)
1887                 return -ENOMEM;
1888         mutex_init(&head->io_sem);
1889         switch (type) {
1890         case TOMOYO_DOMAINPOLICY:
1891                 /* /sys/kernel/security/tomoyo/domain_policy */
1892                 head->write = tomoyo_write_domain_policy;
1893                 head->read = tomoyo_read_domain_policy;
1894                 break;
1895         case TOMOYO_EXCEPTIONPOLICY:
1896                 /* /sys/kernel/security/tomoyo/exception_policy */
1897                 head->write = tomoyo_write_exception_policy;
1898                 head->read = tomoyo_read_exception_policy;
1899                 break;
1900         case TOMOYO_SELFDOMAIN:
1901                 /* /sys/kernel/security/tomoyo/self_domain */
1902                 head->read = tomoyo_read_self_domain;
1903                 break;
1904         case TOMOYO_DOMAIN_STATUS:
1905                 /* /sys/kernel/security/tomoyo/.domain_status */
1906                 head->write = tomoyo_write_domain_profile;
1907                 head->read = tomoyo_read_domain_profile;
1908                 break;
1909         case TOMOYO_PROCESS_STATUS:
1910                 /* /sys/kernel/security/tomoyo/.process_status */
1911                 head->write = tomoyo_write_pid;
1912                 head->read = tomoyo_read_pid;
1913                 break;
1914         case TOMOYO_VERSION:
1915                 /* /sys/kernel/security/tomoyo/version */
1916                 head->read = tomoyo_read_version;
1917                 head->readbuf_size = 128;
1918                 break;
1919         case TOMOYO_MEMINFO:
1920                 /* /sys/kernel/security/tomoyo/meminfo */
1921                 head->write = tomoyo_write_memory_quota;
1922                 head->read = tomoyo_read_memory_counter;
1923                 head->readbuf_size = 512;
1924                 break;
1925         case TOMOYO_PROFILE:
1926                 /* /sys/kernel/security/tomoyo/profile */
1927                 head->write = tomoyo_write_profile;
1928                 head->read = tomoyo_read_profile;
1929                 break;
1930         case TOMOYO_MANAGER:
1931                 /* /sys/kernel/security/tomoyo/manager */
1932                 head->write = tomoyo_write_manager_policy;
1933                 head->read = tomoyo_read_manager_policy;
1934                 break;
1935         }
1936         if (!(file->f_mode & FMODE_READ)) {
1937                 /*
1938                  * No need to allocate read_buf since it is not opened
1939                  * for reading.
1940                  */
1941                 head->read = NULL;
1942         } else {
1943                 if (!head->readbuf_size)
1944                         head->readbuf_size = 4096 * 2;
1945                 head->read_buf = kzalloc(head->readbuf_size, GFP_KERNEL);
1946                 if (!head->read_buf) {
1947                         kfree(head);
1948                         return -ENOMEM;
1949                 }
1950         }
1951         if (!(file->f_mode & FMODE_WRITE)) {
1952                 /*
1953                  * No need to allocate write_buf since it is not opened
1954                  * for writing.
1955                  */
1956                 head->write = NULL;
1957         } else if (head->write) {
1958                 head->writebuf_size = 4096 * 2;
1959                 head->write_buf = kzalloc(head->writebuf_size, GFP_KERNEL);
1960                 if (!head->write_buf) {
1961                         kfree(head->read_buf);
1962                         kfree(head);
1963                         return -ENOMEM;
1964                 }
1965         }
1966         head->reader_idx = tomoyo_read_lock();
1967         file->private_data = head;
1968         /*
1969          * Call the handler now if the file is
1970          * /sys/kernel/security/tomoyo/self_domain
1971          * so that the user can use
1972          * cat < /sys/kernel/security/tomoyo/self_domain"
1973          * to know the current process's domainname.
1974          */
1975         if (type == TOMOYO_SELFDOMAIN)
1976                 tomoyo_read_control(file, NULL, 0);
1977         return 0;
1978 }
1979
1980 /**
1981  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
1982  *
1983  * @file:       Pointer to "struct file".
1984  * @buffer:     Poiner to buffer to write to.
1985  * @buffer_len: Size of @buffer.
1986  *
1987  * Returns bytes read on success, negative value otherwise.
1988  *
1989  * Caller holds tomoyo_read_lock().
1990  */
1991 static int tomoyo_read_control(struct file *file, char __user *buffer,
1992                                const int buffer_len)
1993 {
1994         int len = 0;
1995         struct tomoyo_io_buffer *head = file->private_data;
1996         char *cp;
1997
1998         if (!head->read)
1999                 return -ENOSYS;
2000         if (mutex_lock_interruptible(&head->io_sem))
2001                 return -EINTR;
2002         /* Call the policy handler. */
2003         len = head->read(head);
2004         if (len < 0)
2005                 goto out;
2006         /* Write to buffer. */
2007         len = head->read_avail;
2008         if (len > buffer_len)
2009                 len = buffer_len;
2010         if (!len)
2011                 goto out;
2012         /* head->read_buf changes by some functions. */
2013         cp = head->read_buf;
2014         if (copy_to_user(buffer, cp, len)) {
2015                 len = -EFAULT;
2016                 goto out;
2017         }
2018         head->read_avail -= len;
2019         memmove(cp, cp + len, head->read_avail);
2020  out:
2021         mutex_unlock(&head->io_sem);
2022         return len;
2023 }
2024
2025 /**
2026  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
2027  *
2028  * @file:       Pointer to "struct file".
2029  * @buffer:     Pointer to buffer to read from.
2030  * @buffer_len: Size of @buffer.
2031  *
2032  * Returns @buffer_len on success, negative value otherwise.
2033  *
2034  * Caller holds tomoyo_read_lock().
2035  */
2036 static int tomoyo_write_control(struct file *file, const char __user *buffer,
2037                                 const int buffer_len)
2038 {
2039         struct tomoyo_io_buffer *head = file->private_data;
2040         int error = buffer_len;
2041         int avail_len = buffer_len;
2042         char *cp0 = head->write_buf;
2043
2044         if (!head->write)
2045                 return -ENOSYS;
2046         if (!access_ok(VERIFY_READ, buffer, buffer_len))
2047                 return -EFAULT;
2048         /* Don't allow updating policies by non manager programs. */
2049         if (head->write != tomoyo_write_pid &&
2050             head->write != tomoyo_write_domain_policy &&
2051             !tomoyo_is_policy_manager())
2052                 return -EPERM;
2053         if (mutex_lock_interruptible(&head->io_sem))
2054                 return -EINTR;
2055         /* Read a line and dispatch it to the policy handler. */
2056         while (avail_len > 0) {
2057                 char c;
2058                 if (head->write_avail >= head->writebuf_size - 1) {
2059                         error = -ENOMEM;
2060                         break;
2061                 } else if (get_user(c, buffer)) {
2062                         error = -EFAULT;
2063                         break;
2064                 }
2065                 buffer++;
2066                 avail_len--;
2067                 cp0[head->write_avail++] = c;
2068                 if (c != '\n')
2069                         continue;
2070                 cp0[head->write_avail - 1] = '\0';
2071                 head->write_avail = 0;
2072                 tomoyo_normalize_line(cp0);
2073                 head->write(head);
2074         }
2075         mutex_unlock(&head->io_sem);
2076         return error;
2077 }
2078
2079 /**
2080  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2081  *
2082  * @file: Pointer to "struct file".
2083  *
2084  * Releases memory and returns 0.
2085  *
2086  * Caller looses tomoyo_read_lock().
2087  */
2088 static int tomoyo_close_control(struct file *file)
2089 {
2090         struct tomoyo_io_buffer *head = file->private_data;
2091         const bool is_write = !!head->write_buf;
2092
2093         tomoyo_read_unlock(head->reader_idx);
2094         /* Release memory used for policy I/O. */
2095         kfree(head->read_buf);
2096         head->read_buf = NULL;
2097         kfree(head->write_buf);
2098         head->write_buf = NULL;
2099         kfree(head);
2100         head = NULL;
2101         file->private_data = NULL;
2102         if (is_write)
2103                 tomoyo_run_gc();
2104         return 0;
2105 }
2106
2107 /**
2108  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2109  *
2110  * @inode: Pointer to "struct inode".
2111  * @file:  Pointer to "struct file".
2112  *
2113  * Returns 0 on success, negative value otherwise.
2114  */
2115 static int tomoyo_open(struct inode *inode, struct file *file)
2116 {
2117         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2118                 - ((u8 *) NULL);
2119         return tomoyo_open_control(key, file);
2120 }
2121
2122 /**
2123  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2124  *
2125  * @inode: Pointer to "struct inode".
2126  * @file:  Pointer to "struct file".
2127  *
2128  * Returns 0 on success, negative value otherwise.
2129  */
2130 static int tomoyo_release(struct inode *inode, struct file *file)
2131 {
2132         return tomoyo_close_control(file);
2133 }
2134
2135 /**
2136  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2137  *
2138  * @file:  Pointer to "struct file".
2139  * @buf:   Pointer to buffer.
2140  * @count: Size of @buf.
2141  * @ppos:  Unused.
2142  *
2143  * Returns bytes read on success, negative value otherwise.
2144  */
2145 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2146                            loff_t *ppos)
2147 {
2148         return tomoyo_read_control(file, buf, count);
2149 }
2150
2151 /**
2152  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2153  *
2154  * @file:  Pointer to "struct file".
2155  * @buf:   Pointer to buffer.
2156  * @count: Size of @buf.
2157  * @ppos:  Unused.
2158  *
2159  * Returns @count on success, negative value otherwise.
2160  */
2161 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2162                             size_t count, loff_t *ppos)
2163 {
2164         return tomoyo_write_control(file, buf, count);
2165 }
2166
2167 /*
2168  * tomoyo_operations is a "struct file_operations" which is used for handling
2169  * /sys/kernel/security/tomoyo/ interface.
2170  *
2171  * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR).
2172  * See tomoyo_io_buffer for internals.
2173  */
2174 static const struct file_operations tomoyo_operations = {
2175         .open    = tomoyo_open,
2176         .release = tomoyo_release,
2177         .read    = tomoyo_read,
2178         .write   = tomoyo_write,
2179 };
2180
2181 /**
2182  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2183  *
2184  * @name:   The name of the interface file.
2185  * @mode:   The permission of the interface file.
2186  * @parent: The parent directory.
2187  * @key:    Type of interface.
2188  *
2189  * Returns nothing.
2190  */
2191 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2192                                        struct dentry *parent, const u8 key)
2193 {
2194         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2195                                &tomoyo_operations);
2196 }
2197
2198 /**
2199  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2200  *
2201  * Returns 0.
2202  */
2203 static int __init tomoyo_initerface_init(void)
2204 {
2205         struct dentry *tomoyo_dir;
2206
2207         /* Don't create securityfs entries unless registered. */
2208         if (current_cred()->security != &tomoyo_kernel_domain)
2209                 return 0;
2210
2211         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2212         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2213                             TOMOYO_DOMAINPOLICY);
2214         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2215                             TOMOYO_EXCEPTIONPOLICY);
2216         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2217                             TOMOYO_SELFDOMAIN);
2218         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2219                             TOMOYO_DOMAIN_STATUS);
2220         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2221                             TOMOYO_PROCESS_STATUS);
2222         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2223                             TOMOYO_MEMINFO);
2224         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2225                             TOMOYO_PROFILE);
2226         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2227                             TOMOYO_MANAGER);
2228         tomoyo_create_entry("version",          0400, tomoyo_dir,
2229                             TOMOYO_VERSION);
2230         return 0;
2231 }
2232
2233 fs_initcall(tomoyo_initerface_init);