TOMOYO: Simplify policy reader.
[linux-2.6.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 "realpath.h"
16 #include "common.h"
17 #include "tomoyo.h"
18
19 /* Has loading policy done? */
20 bool tomoyo_policy_loaded;
21
22 /* String table for functionality that takes 4 modes. */
23 static const char *tomoyo_mode_4[4] = {
24         "disabled", "learning", "permissive", "enforcing"
25 };
26 /* String table for functionality that takes 2 modes. */
27 static const char *tomoyo_mode_2[4] = {
28         "disabled", "enabled", "enabled", "enabled"
29 };
30
31 /* Table for profile. */
32 static struct {
33         const char *keyword;
34         unsigned int current_value;
35         const unsigned int max_value;
36 } tomoyo_control_array[TOMOYO_MAX_CONTROL_INDEX] = {
37         [TOMOYO_MAC_FOR_FILE]     = { "MAC_FOR_FILE",        0,       3 },
38         [TOMOYO_MAX_ACCEPT_ENTRY] = { "MAX_ACCEPT_ENTRY", 2048, INT_MAX },
39         [TOMOYO_VERBOSE]          = { "TOMOYO_VERBOSE",      1,       1 },
40 };
41
42 /* Profile table. Memory is allocated as needed. */
43 static struct tomoyo_profile {
44         unsigned int value[TOMOYO_MAX_CONTROL_INDEX];
45         const struct tomoyo_path_info *comment;
46 } *tomoyo_profile_ptr[TOMOYO_MAX_PROFILES];
47
48 /* Permit policy management by non-root user? */
49 static bool tomoyo_manage_by_non_root;
50
51 /* Utility functions. */
52
53 /* Open operation for /sys/kernel/security/tomoyo/ interface. */
54 static int tomoyo_open_control(const u8 type, struct file *file);
55 /* Close /sys/kernel/security/tomoyo/ interface. */
56 static int tomoyo_close_control(struct file *file);
57 /* Read operation for /sys/kernel/security/tomoyo/ interface. */
58 static int tomoyo_read_control(struct file *file, char __user *buffer,
59                                const int buffer_len);
60 /* Write operation for /sys/kernel/security/tomoyo/ interface. */
61 static int tomoyo_write_control(struct file *file, const char __user *buffer,
62                                 const int buffer_len);
63
64 /**
65  * tomoyo_is_byte_range - Check whether the string isa \ooo style octal value.
66  *
67  * @str: Pointer to the string.
68  *
69  * Returns true if @str is a \ooo style octal value, false otherwise.
70  *
71  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
72  * This function verifies that \ooo is in valid range.
73  */
74 static inline bool tomoyo_is_byte_range(const char *str)
75 {
76         return *str >= '0' && *str++ <= '3' &&
77                 *str >= '0' && *str++ <= '7' &&
78                 *str >= '0' && *str <= '7';
79 }
80
81 /**
82  * tomoyo_is_alphabet_char - Check whether the character is an alphabet.
83  *
84  * @c: The character to check.
85  *
86  * Returns true if @c is an alphabet character, false otherwise.
87  */
88 static inline bool tomoyo_is_alphabet_char(const char c)
89 {
90         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
91 }
92
93 /**
94  * tomoyo_make_byte - Make byte value from three octal characters.
95  *
96  * @c1: The first character.
97  * @c2: The second character.
98  * @c3: The third character.
99  *
100  * Returns byte value.
101  */
102 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
103 {
104         return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
105 }
106
107 /**
108  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
109  *
110  * @src:  Pointer to pointer to the string.
111  * @find: Pointer to the keyword.
112  *
113  * Returns true if @src starts with @find, false otherwise.
114  *
115  * The @src is updated to point the first character after the @find
116  * if @src starts with @find.
117  */
118 static bool tomoyo_str_starts(char **src, const char *find)
119 {
120         const int len = strlen(find);
121         char *tmp = *src;
122
123         if (strncmp(tmp, find, len))
124                 return false;
125         tmp += len;
126         *src = tmp;
127         return true;
128 }
129
130 /**
131  * tomoyo_normalize_line - Format string.
132  *
133  * @buffer: The line to normalize.
134  *
135  * Leading and trailing whitespaces are removed.
136  * Multiple whitespaces are packed into single space.
137  *
138  * Returns nothing.
139  */
140 static void tomoyo_normalize_line(unsigned char *buffer)
141 {
142         unsigned char *sp = buffer;
143         unsigned char *dp = buffer;
144         bool first = true;
145
146         while (tomoyo_is_invalid(*sp))
147                 sp++;
148         while (*sp) {
149                 if (!first)
150                         *dp++ = ' ';
151                 first = false;
152                 while (tomoyo_is_valid(*sp))
153                         *dp++ = *sp++;
154                 while (tomoyo_is_invalid(*sp))
155                         sp++;
156         }
157         *dp = '\0';
158 }
159
160 /**
161  * tomoyo_is_correct_path - Validate a pathname.
162  * @filename:     The pathname to check.
163  * @start_type:   Should the pathname start with '/'?
164  *                1 = must / -1 = must not / 0 = don't care
165  * @pattern_type: Can the pathname contain a wildcard?
166  *                1 = must / -1 = must not / 0 = don't care
167  * @end_type:     Should the pathname end with '/'?
168  *                1 = must / -1 = must not / 0 = don't care
169  * @function:     The name of function calling me.
170  *
171  * Check whether the given filename follows the naming rules.
172  * Returns true if @filename follows the naming rules, false otherwise.
173  */
174 bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
175                             const s8 pattern_type, const s8 end_type,
176                             const char *function)
177 {
178         bool contains_pattern = false;
179         unsigned char c;
180         unsigned char d;
181         unsigned char e;
182         const char *original_filename = filename;
183
184         if (!filename)
185                 goto out;
186         c = *filename;
187         if (start_type == 1) { /* Must start with '/' */
188                 if (c != '/')
189                         goto out;
190         } else if (start_type == -1) { /* Must not start with '/' */
191                 if (c == '/')
192                         goto out;
193         }
194         if (c)
195                 c = *(filename + strlen(filename) - 1);
196         if (end_type == 1) { /* Must end with '/' */
197                 if (c != '/')
198                         goto out;
199         } else if (end_type == -1) { /* Must not end with '/' */
200                 if (c == '/')
201                         goto out;
202         }
203         while ((c = *filename++) != '\0') {
204                 if (c == '\\') {
205                         switch ((c = *filename++)) {
206                         case '\\':  /* "\\" */
207                                 continue;
208                         case '$':   /* "\$" */
209                         case '+':   /* "\+" */
210                         case '?':   /* "\?" */
211                         case '*':   /* "\*" */
212                         case '@':   /* "\@" */
213                         case 'x':   /* "\x" */
214                         case 'X':   /* "\X" */
215                         case 'a':   /* "\a" */
216                         case 'A':   /* "\A" */
217                         case '-':   /* "\-" */
218                                 if (pattern_type == -1)
219                                         break; /* Must not contain pattern */
220                                 contains_pattern = true;
221                                 continue;
222                         case '0':   /* "\ooo" */
223                         case '1':
224                         case '2':
225                         case '3':
226                                 d = *filename++;
227                                 if (d < '0' || d > '7')
228                                         break;
229                                 e = *filename++;
230                                 if (e < '0' || e > '7')
231                                         break;
232                                 c = tomoyo_make_byte(c, d, e);
233                                 if (tomoyo_is_invalid(c))
234                                         continue; /* pattern is not \000 */
235                         }
236                         goto out;
237                 } else if (tomoyo_is_invalid(c)) {
238                         goto out;
239                 }
240         }
241         if (pattern_type == 1) { /* Must contain pattern */
242                 if (!contains_pattern)
243                         goto out;
244         }
245         return true;
246  out:
247         printk(KERN_DEBUG "%s: Invalid pathname '%s'\n", function,
248                original_filename);
249         return false;
250 }
251
252 /**
253  * tomoyo_is_correct_domain - Check whether the given domainname follows the naming rules.
254  * @domainname:   The domainname to check.
255  * @function:     The name of function calling me.
256  *
257  * Returns true if @domainname follows the naming rules, false otherwise.
258  */
259 bool tomoyo_is_correct_domain(const unsigned char *domainname,
260                               const char *function)
261 {
262         unsigned char c;
263         unsigned char d;
264         unsigned char e;
265         const char *org_domainname = domainname;
266
267         if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME,
268                                    TOMOYO_ROOT_NAME_LEN))
269                 goto out;
270         domainname += TOMOYO_ROOT_NAME_LEN;
271         if (!*domainname)
272                 return true;
273         do {
274                 if (*domainname++ != ' ')
275                         goto out;
276                 if (*domainname++ != '/')
277                         goto out;
278                 while ((c = *domainname) != '\0' && c != ' ') {
279                         domainname++;
280                         if (c == '\\') {
281                                 c = *domainname++;
282                                 switch ((c)) {
283                                 case '\\':  /* "\\" */
284                                         continue;
285                                 case '0':   /* "\ooo" */
286                                 case '1':
287                                 case '2':
288                                 case '3':
289                                         d = *domainname++;
290                                         if (d < '0' || d > '7')
291                                                 break;
292                                         e = *domainname++;
293                                         if (e < '0' || e > '7')
294                                                 break;
295                                         c = tomoyo_make_byte(c, d, e);
296                                         if (tomoyo_is_invalid(c))
297                                                 /* pattern is not \000 */
298                                                 continue;
299                                 }
300                                 goto out;
301                         } else if (tomoyo_is_invalid(c)) {
302                                 goto out;
303                         }
304                 }
305         } while (*domainname);
306         return true;
307  out:
308         printk(KERN_DEBUG "%s: Invalid domainname '%s'\n", function,
309                org_domainname);
310         return false;
311 }
312
313 /**
314  * tomoyo_is_domain_def - Check whether the given token can be a domainname.
315  *
316  * @buffer: The token to check.
317  *
318  * Returns true if @buffer possibly be a domainname, false otherwise.
319  */
320 bool tomoyo_is_domain_def(const unsigned char *buffer)
321 {
322         return !strncmp(buffer, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN);
323 }
324
325 /**
326  * tomoyo_find_domain - Find a domain by the given name.
327  *
328  * @domainname: The domainname to find.
329  *
330  * Caller must call down_read(&tomoyo_domain_list_lock); or
331  * down_write(&tomoyo_domain_list_lock); .
332  *
333  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
334  */
335 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
336 {
337         struct tomoyo_domain_info *domain;
338         struct tomoyo_path_info name;
339
340         name.name = domainname;
341         tomoyo_fill_path_info(&name);
342         list_for_each_entry(domain, &tomoyo_domain_list, list) {
343                 if (!domain->is_deleted &&
344                     !tomoyo_pathcmp(&name, domain->domainname))
345                         return domain;
346         }
347         return NULL;
348 }
349
350 /**
351  * tomoyo_path_depth - Evaluate the number of '/' in a string.
352  *
353  * @pathname: The string to evaluate.
354  *
355  * Returns path depth of the string.
356  *
357  * I score 2 for each of the '/' in the @pathname
358  * and score 1 if the @pathname ends with '/'.
359  */
360 static int tomoyo_path_depth(const char *pathname)
361 {
362         int i = 0;
363
364         if (pathname) {
365                 const char *ep = pathname + strlen(pathname);
366                 if (pathname < ep--) {
367                         if (*ep != '/')
368                                 i++;
369                         while (pathname <= ep)
370                                 if (*ep-- == '/')
371                                         i += 2;
372                 }
373         }
374         return i;
375 }
376
377 /**
378  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
379  *
380  * @filename: The string to evaluate.
381  *
382  * Returns the initial length without a pattern in @filename.
383  */
384 static int tomoyo_const_part_length(const char *filename)
385 {
386         char c;
387         int len = 0;
388
389         if (!filename)
390                 return 0;
391         while ((c = *filename++) != '\0') {
392                 if (c != '\\') {
393                         len++;
394                         continue;
395                 }
396                 c = *filename++;
397                 switch (c) {
398                 case '\\':  /* "\\" */
399                         len += 2;
400                         continue;
401                 case '0':   /* "\ooo" */
402                 case '1':
403                 case '2':
404                 case '3':
405                         c = *filename++;
406                         if (c < '0' || c > '7')
407                                 break;
408                         c = *filename++;
409                         if (c < '0' || c > '7')
410                                 break;
411                         len += 4;
412                         continue;
413                 }
414                 break;
415         }
416         return len;
417 }
418
419 /**
420  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
421  *
422  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
423  *
424  * The caller sets "struct tomoyo_path_info"->name.
425  */
426 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
427 {
428         const char *name = ptr->name;
429         const int len = strlen(name);
430
431         ptr->total_len = len;
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         ptr->depth = tomoyo_path_depth(name);
437 }
438
439 /**
440  * tomoyo_file_matches_to_pattern2 - Pattern matching without '/' character
441  * and "\-" pattern.
442  *
443  * @filename:     The start of string to check.
444  * @filename_end: The end of string to check.
445  * @pattern:      The start of pattern to compare.
446  * @pattern_end:  The end of pattern to compare.
447  *
448  * Returns true if @filename matches @pattern, false otherwise.
449  */
450 static bool tomoyo_file_matches_to_pattern2(const char *filename,
451                                             const char *filename_end,
452                                             const char *pattern,
453                                             const char *pattern_end)
454 {
455         while (filename < filename_end && pattern < pattern_end) {
456                 char c;
457                 if (*pattern != '\\') {
458                         if (*filename++ != *pattern++)
459                                 return false;
460                         continue;
461                 }
462                 c = *filename;
463                 pattern++;
464                 switch (*pattern) {
465                         int i;
466                         int j;
467                 case '?':
468                         if (c == '/') {
469                                 return false;
470                         } else if (c == '\\') {
471                                 if (filename[1] == '\\')
472                                         filename++;
473                                 else if (tomoyo_is_byte_range(filename + 1))
474                                         filename += 3;
475                                 else
476                                         return false;
477                         }
478                         break;
479                 case '\\':
480                         if (c != '\\')
481                                 return false;
482                         if (*++filename != '\\')
483                                 return false;
484                         break;
485                 case '+':
486                         if (!isdigit(c))
487                                 return false;
488                         break;
489                 case 'x':
490                         if (!isxdigit(c))
491                                 return false;
492                         break;
493                 case 'a':
494                         if (!tomoyo_is_alphabet_char(c))
495                                 return false;
496                         break;
497                 case '0':
498                 case '1':
499                 case '2':
500                 case '3':
501                         if (c == '\\' && tomoyo_is_byte_range(filename + 1)
502                             && strncmp(filename + 1, pattern, 3) == 0) {
503                                 filename += 3;
504                                 pattern += 2;
505                                 break;
506                         }
507                         return false; /* Not matched. */
508                 case '*':
509                 case '@':
510                         for (i = 0; i <= filename_end - filename; i++) {
511                                 if (tomoyo_file_matches_to_pattern2(
512                                                     filename + i, filename_end,
513                                                     pattern + 1, pattern_end))
514                                         return true;
515                                 c = filename[i];
516                                 if (c == '.' && *pattern == '@')
517                                         break;
518                                 if (c != '\\')
519                                         continue;
520                                 if (filename[i + 1] == '\\')
521                                         i++;
522                                 else if (tomoyo_is_byte_range(filename + i + 1))
523                                         i += 3;
524                                 else
525                                         break; /* Bad pattern. */
526                         }
527                         return false; /* Not matched. */
528                 default:
529                         j = 0;
530                         c = *pattern;
531                         if (c == '$') {
532                                 while (isdigit(filename[j]))
533                                         j++;
534                         } else if (c == 'X') {
535                                 while (isxdigit(filename[j]))
536                                         j++;
537                         } else if (c == 'A') {
538                                 while (tomoyo_is_alphabet_char(filename[j]))
539                                         j++;
540                         }
541                         for (i = 1; i <= j; i++) {
542                                 if (tomoyo_file_matches_to_pattern2(
543                                                     filename + i, filename_end,
544                                                     pattern + 1, pattern_end))
545                                         return true;
546                         }
547                         return false; /* Not matched or bad pattern. */
548                 }
549                 filename++;
550                 pattern++;
551         }
552         while (*pattern == '\\' &&
553                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
554                 pattern += 2;
555         return filename == filename_end && pattern == pattern_end;
556 }
557
558 /**
559  * tomoyo_file_matches_to_pattern - Pattern matching without without '/' character.
560  *
561  * @filename:     The start of string to check.
562  * @filename_end: The end of string to check.
563  * @pattern:      The start of pattern to compare.
564  * @pattern_end:  The end of pattern to compare.
565  *
566  * Returns true if @filename matches @pattern, false otherwise.
567  */
568 static bool tomoyo_file_matches_to_pattern(const char *filename,
569                                            const char *filename_end,
570                                            const char *pattern,
571                                            const char *pattern_end)
572 {
573         const char *pattern_start = pattern;
574         bool first = true;
575         bool result;
576
577         while (pattern < pattern_end - 1) {
578                 /* Split at "\-" pattern. */
579                 if (*pattern++ != '\\' || *pattern++ != '-')
580                         continue;
581                 result = tomoyo_file_matches_to_pattern2(filename,
582                                                          filename_end,
583                                                          pattern_start,
584                                                          pattern - 2);
585                 if (first)
586                         result = !result;
587                 if (result)
588                         return false;
589                 first = false;
590                 pattern_start = pattern;
591         }
592         result = tomoyo_file_matches_to_pattern2(filename, filename_end,
593                                                  pattern_start, pattern_end);
594         return first ? result : !result;
595 }
596
597 /**
598  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
599  * @filename: The filename to check.
600  * @pattern:  The pattern to compare.
601  *
602  * Returns true if matches, false otherwise.
603  *
604  * The following patterns are available.
605  *   \\     \ itself.
606  *   \ooo   Octal representation of a byte.
607  *   \*     More than or equals to 0 character other than '/'.
608  *   \@     More than or equals to 0 character other than '/' or '.'.
609  *   \?     1 byte character other than '/'.
610  *   \$     More than or equals to 1 decimal digit.
611  *   \+     1 decimal digit.
612  *   \X     More than or equals to 1 hexadecimal digit.
613  *   \x     1 hexadecimal digit.
614  *   \A     More than or equals to 1 alphabet character.
615  *   \a     1 alphabet character.
616  *   \-     Subtraction operator.
617  */
618 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
619                                  const struct tomoyo_path_info *pattern)
620 {
621         /*
622           if (!filename || !pattern)
623           return false;
624         */
625         const char *f = filename->name;
626         const char *p = pattern->name;
627         const int len = pattern->const_len;
628
629         /* If @pattern doesn't contain pattern, I can use strcmp(). */
630         if (!pattern->is_patterned)
631                 return !tomoyo_pathcmp(filename, pattern);
632         /* Dont compare if the number of '/' differs. */
633         if (filename->depth != pattern->depth)
634                 return false;
635         /* Compare the initial length without patterns. */
636         if (strncmp(f, p, len))
637                 return false;
638         f += len;
639         p += len;
640         /* Main loop. Compare each directory component. */
641         while (*f && *p) {
642                 const char *f_delimiter = strchr(f, '/');
643                 const char *p_delimiter = strchr(p, '/');
644                 if (!f_delimiter)
645                         f_delimiter = f + strlen(f);
646                 if (!p_delimiter)
647                         p_delimiter = p + strlen(p);
648                 if (!tomoyo_file_matches_to_pattern(f, f_delimiter,
649                                                     p, p_delimiter))
650                         return false;
651                 f = f_delimiter;
652                 if (*f)
653                         f++;
654                 p = p_delimiter;
655                 if (*p)
656                         p++;
657         }
658         /* Ignore trailing "\*" and "\@" in @pattern. */
659         while (*p == '\\' &&
660                (*(p + 1) == '*' || *(p + 1) == '@'))
661                 p += 2;
662         return !*f && !*p;
663 }
664
665 /**
666  * tomoyo_io_printf - Transactional printf() to "struct tomoyo_io_buffer" structure.
667  *
668  * @head: Pointer to "struct tomoyo_io_buffer".
669  * @fmt:  The printf()'s format string, followed by parameters.
670  *
671  * Returns true if output was written, false otherwise.
672  *
673  * The snprintf() will truncate, but tomoyo_io_printf() won't.
674  */
675 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
676 {
677         va_list args;
678         int len;
679         int pos = head->read_avail;
680         int size = head->readbuf_size - pos;
681
682         if (size <= 0)
683                 return false;
684         va_start(args, fmt);
685         len = vsnprintf(head->read_buf + pos, size, fmt, args);
686         va_end(args);
687         if (pos + len >= head->readbuf_size)
688                 return false;
689         head->read_avail += len;
690         return true;
691 }
692
693 /**
694  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
695  *
696  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
697  *
698  * This function uses tomoyo_alloc(), so the caller must call tomoyo_free()
699  * if this function didn't return NULL.
700  */
701 static const char *tomoyo_get_exe(void)
702 {
703         struct mm_struct *mm = current->mm;
704         struct vm_area_struct *vma;
705         const char *cp = NULL;
706
707         if (!mm)
708                 return NULL;
709         down_read(&mm->mmap_sem);
710         for (vma = mm->mmap; vma; vma = vma->vm_next) {
711                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
712                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
713                         break;
714                 }
715         }
716         up_read(&mm->mmap_sem);
717         return cp;
718 }
719
720 /**
721  * tomoyo_get_msg - Get warning message.
722  *
723  * @is_enforce: Is it enforcing mode?
724  *
725  * Returns "ERROR" or "WARNING".
726  */
727 const char *tomoyo_get_msg(const bool is_enforce)
728 {
729         if (is_enforce)
730                 return "ERROR";
731         else
732                 return "WARNING";
733 }
734
735 /**
736  * tomoyo_check_flags - Check mode for specified functionality.
737  *
738  * @domain: Pointer to "struct tomoyo_domain_info".
739  * @index:  The functionality to check mode.
740  *
741  * TOMOYO checks only process context.
742  * This code disables TOMOYO's enforcement in case the function is called from
743  * interrupt context.
744  */
745 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
746                                 const u8 index)
747 {
748         const u8 profile = domain->profile;
749
750         if (WARN_ON(in_interrupt()))
751                 return 0;
752         return tomoyo_policy_loaded && index < TOMOYO_MAX_CONTROL_INDEX
753 #if TOMOYO_MAX_PROFILES != 256
754                 && profile < TOMOYO_MAX_PROFILES
755 #endif
756                 && tomoyo_profile_ptr[profile] ?
757                 tomoyo_profile_ptr[profile]->value[index] : 0;
758 }
759
760 /**
761  * tomoyo_verbose_mode - Check whether TOMOYO is verbose mode.
762  *
763  * @domain: Pointer to "struct tomoyo_domain_info".
764  *
765  * Returns true if domain policy violation warning should be printed to
766  * console.
767  */
768 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain)
769 {
770         return tomoyo_check_flags(domain, TOMOYO_VERBOSE) != 0;
771 }
772
773 /**
774  * tomoyo_domain_quota_is_ok - Check for domain's quota.
775  *
776  * @domain: Pointer to "struct tomoyo_domain_info".
777  *
778  * Returns true if the domain is not exceeded quota, false otherwise.
779  */
780 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
781 {
782         unsigned int count = 0;
783         struct tomoyo_acl_info *ptr;
784
785         if (!domain)
786                 return true;
787         down_read(&tomoyo_domain_acl_info_list_lock);
788         list_for_each_entry(ptr, &domain->acl_info_list, list) {
789                 if (ptr->type & TOMOYO_ACL_DELETED)
790                         continue;
791                 switch (tomoyo_acl_type2(ptr)) {
792                         struct tomoyo_single_path_acl_record *acl1;
793                         struct tomoyo_double_path_acl_record *acl2;
794                         u16 perm;
795                 case TOMOYO_TYPE_SINGLE_PATH_ACL:
796                         acl1 = container_of(ptr,
797                                     struct tomoyo_single_path_acl_record,
798                                             head);
799                         perm = acl1->perm;
800                         if (perm & (1 << TOMOYO_TYPE_EXECUTE_ACL))
801                                 count++;
802                         if (perm &
803                             ((1 << TOMOYO_TYPE_READ_ACL) |
804                              (1 << TOMOYO_TYPE_WRITE_ACL)))
805                                 count++;
806                         if (perm & (1 << TOMOYO_TYPE_CREATE_ACL))
807                                 count++;
808                         if (perm & (1 << TOMOYO_TYPE_UNLINK_ACL))
809                                 count++;
810                         if (perm & (1 << TOMOYO_TYPE_MKDIR_ACL))
811                                 count++;
812                         if (perm & (1 << TOMOYO_TYPE_RMDIR_ACL))
813                                 count++;
814                         if (perm & (1 << TOMOYO_TYPE_MKFIFO_ACL))
815                                 count++;
816                         if (perm & (1 << TOMOYO_TYPE_MKSOCK_ACL))
817                                 count++;
818                         if (perm & (1 << TOMOYO_TYPE_MKBLOCK_ACL))
819                                 count++;
820                         if (perm & (1 << TOMOYO_TYPE_MKCHAR_ACL))
821                                 count++;
822                         if (perm & (1 << TOMOYO_TYPE_TRUNCATE_ACL))
823                                 count++;
824                         if (perm & (1 << TOMOYO_TYPE_SYMLINK_ACL))
825                                 count++;
826                         if (perm & (1 << TOMOYO_TYPE_REWRITE_ACL))
827                                 count++;
828                         break;
829                 case TOMOYO_TYPE_DOUBLE_PATH_ACL:
830                         acl2 = container_of(ptr,
831                                     struct tomoyo_double_path_acl_record,
832                                             head);
833                         perm = acl2->perm;
834                         if (perm & (1 << TOMOYO_TYPE_LINK_ACL))
835                                 count++;
836                         if (perm & (1 << TOMOYO_TYPE_RENAME_ACL))
837                                 count++;
838                         break;
839                 }
840         }
841         up_read(&tomoyo_domain_acl_info_list_lock);
842         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
843                 return true;
844         if (!domain->quota_warned) {
845                 domain->quota_warned = true;
846                 printk(KERN_WARNING "TOMOYO-WARNING: "
847                        "Domain '%s' has so many ACLs to hold. "
848                        "Stopped learning mode.\n", domain->domainname->name);
849         }
850         return false;
851 }
852
853 /**
854  * tomoyo_find_or_assign_new_profile - Create a new profile.
855  *
856  * @profile: Profile number to create.
857  *
858  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
859  */
860 static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned
861                                                                 int profile)
862 {
863         static DEFINE_MUTEX(lock);
864         struct tomoyo_profile *ptr = NULL;
865         int i;
866
867         if (profile >= TOMOYO_MAX_PROFILES)
868                 return NULL;
869         mutex_lock(&lock);
870         ptr = tomoyo_profile_ptr[profile];
871         if (ptr)
872                 goto ok;
873         ptr = tomoyo_alloc_element(sizeof(*ptr));
874         if (!ptr)
875                 goto ok;
876         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
877                 ptr->value[i] = tomoyo_control_array[i].current_value;
878         mb(); /* Avoid out-of-order execution. */
879         tomoyo_profile_ptr[profile] = ptr;
880  ok:
881         mutex_unlock(&lock);
882         return ptr;
883 }
884
885 /**
886  * tomoyo_write_profile - Write to profile table.
887  *
888  * @head: Pointer to "struct tomoyo_io_buffer".
889  *
890  * Returns 0 on success, negative value otherwise.
891  */
892 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
893 {
894         char *data = head->write_buf;
895         unsigned int i;
896         unsigned int value;
897         char *cp;
898         struct tomoyo_profile *profile;
899         unsigned long num;
900
901         cp = strchr(data, '-');
902         if (cp)
903                 *cp = '\0';
904         if (strict_strtoul(data, 10, &num))
905                 return -EINVAL;
906         if (cp)
907                 data = cp + 1;
908         profile = tomoyo_find_or_assign_new_profile(num);
909         if (!profile)
910                 return -EINVAL;
911         cp = strchr(data, '=');
912         if (!cp)
913                 return -EINVAL;
914         *cp = '\0';
915         if (!strcmp(data, "COMMENT")) {
916                 profile->comment = tomoyo_save_name(cp + 1);
917                 return 0;
918         }
919         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
920                 if (strcmp(data, tomoyo_control_array[i].keyword))
921                         continue;
922                 if (sscanf(cp + 1, "%u", &value) != 1) {
923                         int j;
924                         const char **modes;
925                         switch (i) {
926                         case TOMOYO_VERBOSE:
927                                 modes = tomoyo_mode_2;
928                                 break;
929                         default:
930                                 modes = tomoyo_mode_4;
931                                 break;
932                         }
933                         for (j = 0; j < 4; j++) {
934                                 if (strcmp(cp + 1, modes[j]))
935                                         continue;
936                                 value = j;
937                                 break;
938                         }
939                         if (j == 4)
940                                 return -EINVAL;
941                 } else if (value > tomoyo_control_array[i].max_value) {
942                         value = tomoyo_control_array[i].max_value;
943                 }
944                 profile->value[i] = value;
945                 return 0;
946         }
947         return -EINVAL;
948 }
949
950 /**
951  * tomoyo_read_profile - Read from profile table.
952  *
953  * @head: Pointer to "struct tomoyo_io_buffer".
954  *
955  * Returns 0.
956  */
957 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
958 {
959         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
960         int step;
961
962         if (head->read_eof)
963                 return 0;
964         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
965              step++) {
966                 const u8 index = step / total;
967                 u8 type = step % total;
968                 const struct tomoyo_profile *profile
969                         = tomoyo_profile_ptr[index];
970                 head->read_step = step;
971                 if (!profile)
972                         continue;
973                 if (!type) { /* Print profile' comment tag. */
974                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
975                                               index, profile->comment ?
976                                               profile->comment->name : ""))
977                                 break;
978                         continue;
979                 }
980                 type--;
981                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
982                         const unsigned int value = profile->value[type];
983                         const char **modes = NULL;
984                         const char *keyword
985                                 = tomoyo_control_array[type].keyword;
986                         switch (tomoyo_control_array[type].max_value) {
987                         case 3:
988                                 modes = tomoyo_mode_4;
989                                 break;
990                         case 1:
991                                 modes = tomoyo_mode_2;
992                                 break;
993                         }
994                         if (modes) {
995                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
996                                                       keyword, modes[value]))
997                                         break;
998                         } else {
999                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1000                                                       keyword, value))
1001                                         break;
1002                         }
1003                 }
1004         }
1005         if (step == TOMOYO_MAX_PROFILES * total)
1006                 head->read_eof = true;
1007         return 0;
1008 }
1009
1010 /* Structure for policy manager. */
1011 struct tomoyo_policy_manager_entry {
1012         struct list_head list;
1013         /* A path to program or a domainname. */
1014         const struct tomoyo_path_info *manager;
1015         bool is_domain;  /* True if manager is a domainname. */
1016         bool is_deleted; /* True if this entry is deleted. */
1017 };
1018
1019 /* The list for "struct tomoyo_policy_manager_entry". */
1020 static LIST_HEAD(tomoyo_policy_manager_list);
1021 static DECLARE_RWSEM(tomoyo_policy_manager_list_lock);
1022
1023 /**
1024  * tomoyo_update_manager_entry - Add a manager entry.
1025  *
1026  * @manager:   The path to manager or the domainnamme.
1027  * @is_delete: True if it is a delete request.
1028  *
1029  * Returns 0 on success, negative value otherwise.
1030  */
1031 static int tomoyo_update_manager_entry(const char *manager,
1032                                        const bool is_delete)
1033 {
1034         struct tomoyo_policy_manager_entry *new_entry;
1035         struct tomoyo_policy_manager_entry *ptr;
1036         const struct tomoyo_path_info *saved_manager;
1037         int error = -ENOMEM;
1038         bool is_domain = false;
1039
1040         if (tomoyo_is_domain_def(manager)) {
1041                 if (!tomoyo_is_correct_domain(manager, __func__))
1042                         return -EINVAL;
1043                 is_domain = true;
1044         } else {
1045                 if (!tomoyo_is_correct_path(manager, 1, -1, -1, __func__))
1046                         return -EINVAL;
1047         }
1048         saved_manager = tomoyo_save_name(manager);
1049         if (!saved_manager)
1050                 return -ENOMEM;
1051         down_write(&tomoyo_policy_manager_list_lock);
1052         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1053                 if (ptr->manager != saved_manager)
1054                         continue;
1055                 ptr->is_deleted = is_delete;
1056                 error = 0;
1057                 goto out;
1058         }
1059         if (is_delete) {
1060                 error = -ENOENT;
1061                 goto out;
1062         }
1063         new_entry = tomoyo_alloc_element(sizeof(*new_entry));
1064         if (!new_entry)
1065                 goto out;
1066         new_entry->manager = saved_manager;
1067         new_entry->is_domain = is_domain;
1068         list_add_tail(&new_entry->list, &tomoyo_policy_manager_list);
1069         error = 0;
1070  out:
1071         up_write(&tomoyo_policy_manager_list_lock);
1072         return error;
1073 }
1074
1075 /**
1076  * tomoyo_write_manager_policy - Write manager policy.
1077  *
1078  * @head: Pointer to "struct tomoyo_io_buffer".
1079  *
1080  * Returns 0 on success, negative value otherwise.
1081  */
1082 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1083 {
1084         char *data = head->write_buf;
1085         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1086
1087         if (!strcmp(data, "manage_by_non_root")) {
1088                 tomoyo_manage_by_non_root = !is_delete;
1089                 return 0;
1090         }
1091         return tomoyo_update_manager_entry(data, is_delete);
1092 }
1093
1094 /**
1095  * tomoyo_read_manager_policy - Read manager policy.
1096  *
1097  * @head: Pointer to "struct tomoyo_io_buffer".
1098  *
1099  * Returns 0.
1100  */
1101 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1102 {
1103         struct list_head *pos;
1104         bool done = true;
1105
1106         if (head->read_eof)
1107                 return 0;
1108         down_read(&tomoyo_policy_manager_list_lock);
1109         list_for_each_cookie(pos, head->read_var2,
1110                              &tomoyo_policy_manager_list) {
1111                 struct tomoyo_policy_manager_entry *ptr;
1112                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1113                                  list);
1114                 if (ptr->is_deleted)
1115                         continue;
1116                 done = tomoyo_io_printf(head, "%s\n", ptr->manager->name);
1117                 if (!done)
1118                         break;
1119         }
1120         up_read(&tomoyo_policy_manager_list_lock);
1121         head->read_eof = done;
1122         return 0;
1123 }
1124
1125 /**
1126  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1127  *
1128  * Returns true if the current process is permitted to modify policy
1129  * via /sys/kernel/security/tomoyo/ interface.
1130  */
1131 static bool tomoyo_is_policy_manager(void)
1132 {
1133         struct tomoyo_policy_manager_entry *ptr;
1134         const char *exe;
1135         const struct task_struct *task = current;
1136         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1137         bool found = false;
1138
1139         if (!tomoyo_policy_loaded)
1140                 return true;
1141         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1142                 return false;
1143         down_read(&tomoyo_policy_manager_list_lock);
1144         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1145                 if (!ptr->is_deleted && ptr->is_domain
1146                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1147                         found = true;
1148                         break;
1149                 }
1150         }
1151         up_read(&tomoyo_policy_manager_list_lock);
1152         if (found)
1153                 return true;
1154         exe = tomoyo_get_exe();
1155         if (!exe)
1156                 return false;
1157         down_read(&tomoyo_policy_manager_list_lock);
1158         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1159                 if (!ptr->is_deleted && !ptr->is_domain
1160                     && !strcmp(exe, ptr->manager->name)) {
1161                         found = true;
1162                         break;
1163                 }
1164         }
1165         up_read(&tomoyo_policy_manager_list_lock);
1166         if (!found) { /* Reduce error messages. */
1167                 static pid_t last_pid;
1168                 const pid_t pid = current->pid;
1169                 if (last_pid != pid) {
1170                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1171                                "update policies.\n", domainname->name, exe);
1172                         last_pid = pid;
1173                 }
1174         }
1175         tomoyo_free(exe);
1176         return found;
1177 }
1178
1179 /**
1180  * tomoyo_is_select_one - Parse select command.
1181  *
1182  * @head: Pointer to "struct tomoyo_io_buffer".
1183  * @data: String to parse.
1184  *
1185  * Returns true on success, false otherwise.
1186  */
1187 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1188                                  const char *data)
1189 {
1190         unsigned int pid;
1191         struct tomoyo_domain_info *domain = NULL;
1192
1193         if (sscanf(data, "pid=%u", &pid) == 1) {
1194                 struct task_struct *p;
1195                 read_lock(&tasklist_lock);
1196                 p = find_task_by_vpid(pid);
1197                 if (p)
1198                         domain = tomoyo_real_domain(p);
1199                 read_unlock(&tasklist_lock);
1200         } else if (!strncmp(data, "domain=", 7)) {
1201                 if (tomoyo_is_domain_def(data + 7)) {
1202                         down_read(&tomoyo_domain_list_lock);
1203                         domain = tomoyo_find_domain(data + 7);
1204                         up_read(&tomoyo_domain_list_lock);
1205                 }
1206         } else
1207                 return false;
1208         head->write_var1 = domain;
1209         /* Accessing read_buf is safe because head->io_sem is held. */
1210         if (!head->read_buf)
1211                 return true; /* Do nothing if open(O_WRONLY). */
1212         head->read_avail = 0;
1213         tomoyo_io_printf(head, "# select %s\n", data);
1214         head->read_single_domain = true;
1215         head->read_eof = !domain;
1216         if (domain) {
1217                 struct tomoyo_domain_info *d;
1218                 head->read_var1 = NULL;
1219                 down_read(&tomoyo_domain_list_lock);
1220                 list_for_each_entry(d, &tomoyo_domain_list, list) {
1221                         if (d == domain)
1222                                 break;
1223                         head->read_var1 = &d->list;
1224                 }
1225                 up_read(&tomoyo_domain_list_lock);
1226                 head->read_var2 = NULL;
1227                 head->read_bit = 0;
1228                 head->read_step = 0;
1229                 if (domain->is_deleted)
1230                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1231         }
1232         return true;
1233 }
1234
1235 /**
1236  * tomoyo_write_domain_policy - Write domain policy.
1237  *
1238  * @head: Pointer to "struct tomoyo_io_buffer".
1239  *
1240  * Returns 0 on success, negative value otherwise.
1241  */
1242 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1243 {
1244         char *data = head->write_buf;
1245         struct tomoyo_domain_info *domain = head->write_var1;
1246         bool is_delete = false;
1247         bool is_select = false;
1248         unsigned int profile;
1249
1250         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1251                 is_delete = true;
1252         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1253                 is_select = true;
1254         if (is_select && tomoyo_is_select_one(head, data))
1255                 return 0;
1256         /* Don't allow updating policies by non manager programs. */
1257         if (!tomoyo_is_policy_manager())
1258                 return -EPERM;
1259         if (tomoyo_is_domain_def(data)) {
1260                 domain = NULL;
1261                 if (is_delete)
1262                         tomoyo_delete_domain(data);
1263                 else if (is_select) {
1264                         down_read(&tomoyo_domain_list_lock);
1265                         domain = tomoyo_find_domain(data);
1266                         up_read(&tomoyo_domain_list_lock);
1267                 } else
1268                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1269                 head->write_var1 = domain;
1270                 return 0;
1271         }
1272         if (!domain)
1273                 return -EINVAL;
1274
1275         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1276             && profile < TOMOYO_MAX_PROFILES) {
1277                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1278                         domain->profile = (u8) profile;
1279                 return 0;
1280         }
1281         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1282                 tomoyo_set_domain_flag(domain, is_delete,
1283                                TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ);
1284                 return 0;
1285         }
1286         return tomoyo_write_file_policy(data, domain, is_delete);
1287 }
1288
1289 /**
1290  * tomoyo_print_single_path_acl - Print a single path ACL entry.
1291  *
1292  * @head: Pointer to "struct tomoyo_io_buffer".
1293  * @ptr:  Pointer to "struct tomoyo_single_path_acl_record".
1294  *
1295  * Returns true on success, false otherwise.
1296  */
1297 static bool tomoyo_print_single_path_acl(struct tomoyo_io_buffer *head,
1298                                          struct tomoyo_single_path_acl_record *
1299                                          ptr)
1300 {
1301         int pos;
1302         u8 bit;
1303         const char *atmark = "";
1304         const char *filename;
1305         const u16 perm = ptr->perm;
1306
1307         filename = ptr->filename->name;
1308         for (bit = head->read_bit; bit < TOMOYO_MAX_SINGLE_PATH_OPERATION;
1309              bit++) {
1310                 const char *msg;
1311                 if (!(perm & (1 << bit)))
1312                         continue;
1313                 /* Print "read/write" instead of "read" and "write". */
1314                 if ((bit == TOMOYO_TYPE_READ_ACL ||
1315                      bit == TOMOYO_TYPE_WRITE_ACL)
1316                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL)))
1317                         continue;
1318                 msg = tomoyo_sp2keyword(bit);
1319                 pos = head->read_avail;
1320                 if (!tomoyo_io_printf(head, "allow_%s %s%s\n", msg,
1321                                       atmark, filename))
1322                         goto out;
1323         }
1324         head->read_bit = 0;
1325         return true;
1326  out:
1327         head->read_bit = bit;
1328         head->read_avail = pos;
1329         return false;
1330 }
1331
1332 /**
1333  * tomoyo_print_double_path_acl - Print a double path ACL entry.
1334  *
1335  * @head: Pointer to "struct tomoyo_io_buffer".
1336  * @ptr:  Pointer to "struct tomoyo_double_path_acl_record".
1337  *
1338  * Returns true on success, false otherwise.
1339  */
1340 static bool tomoyo_print_double_path_acl(struct tomoyo_io_buffer *head,
1341                                          struct tomoyo_double_path_acl_record *
1342                                          ptr)
1343 {
1344         int pos;
1345         const char *atmark1 = "";
1346         const char *atmark2 = "";
1347         const char *filename1;
1348         const char *filename2;
1349         const u8 perm = ptr->perm;
1350         u8 bit;
1351
1352         filename1 = ptr->filename1->name;
1353         filename2 = ptr->filename2->name;
1354         for (bit = head->read_bit; bit < TOMOYO_MAX_DOUBLE_PATH_OPERATION;
1355              bit++) {
1356                 const char *msg;
1357                 if (!(perm & (1 << bit)))
1358                         continue;
1359                 msg = tomoyo_dp2keyword(bit);
1360                 pos = head->read_avail;
1361                 if (!tomoyo_io_printf(head, "allow_%s %s%s %s%s\n", msg,
1362                                       atmark1, filename1, atmark2, filename2))
1363                         goto out;
1364         }
1365         head->read_bit = 0;
1366         return true;
1367  out:
1368         head->read_bit = bit;
1369         head->read_avail = pos;
1370         return false;
1371 }
1372
1373 /**
1374  * tomoyo_print_entry - Print an ACL entry.
1375  *
1376  * @head: Pointer to "struct tomoyo_io_buffer".
1377  * @ptr:  Pointer to an ACL entry.
1378  *
1379  * Returns true on success, false otherwise.
1380  */
1381 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1382                                struct tomoyo_acl_info *ptr)
1383 {
1384         const u8 acl_type = tomoyo_acl_type2(ptr);
1385
1386         if (acl_type & TOMOYO_ACL_DELETED)
1387                 return true;
1388         if (acl_type == TOMOYO_TYPE_SINGLE_PATH_ACL) {
1389                 struct tomoyo_single_path_acl_record *acl
1390                         = container_of(ptr,
1391                                        struct tomoyo_single_path_acl_record,
1392                                        head);
1393                 return tomoyo_print_single_path_acl(head, acl);
1394         }
1395         if (acl_type == TOMOYO_TYPE_DOUBLE_PATH_ACL) {
1396                 struct tomoyo_double_path_acl_record *acl
1397                         = container_of(ptr,
1398                                        struct tomoyo_double_path_acl_record,
1399                                        head);
1400                 return tomoyo_print_double_path_acl(head, acl);
1401         }
1402         BUG(); /* This must not happen. */
1403         return false;
1404 }
1405
1406 /**
1407  * tomoyo_read_domain_policy - Read domain policy.
1408  *
1409  * @head: Pointer to "struct tomoyo_io_buffer".
1410  *
1411  * Returns 0.
1412  */
1413 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1414 {
1415         struct list_head *dpos;
1416         struct list_head *apos;
1417         bool done = true;
1418
1419         if (head->read_eof)
1420                 return 0;
1421         if (head->read_step == 0)
1422                 head->read_step = 1;
1423         down_read(&tomoyo_domain_list_lock);
1424         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1425                 struct tomoyo_domain_info *domain;
1426                 const char *quota_exceeded = "";
1427                 const char *transition_failed = "";
1428                 const char *ignore_global_allow_read = "";
1429                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1430                 if (head->read_step != 1)
1431                         goto acl_loop;
1432                 if (domain->is_deleted && !head->read_single_domain)
1433                         continue;
1434                 /* Print domainname and flags. */
1435                 if (domain->quota_warned)
1436                         quota_exceeded = "quota_exceeded\n";
1437                 if (domain->flags & TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED)
1438                         transition_failed = "transition_failed\n";
1439                 if (domain->flags &
1440                     TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ)
1441                         ignore_global_allow_read
1442                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1443                 done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
1444                                         "%u\n%s%s%s\n",
1445                                         domain->domainname->name,
1446                                         domain->profile, quota_exceeded,
1447                                         transition_failed,
1448                                         ignore_global_allow_read);
1449                 if (!done)
1450                         break;
1451                 head->read_step = 2;
1452 acl_loop:
1453                 if (head->read_step == 3)
1454                         goto tail_mark;
1455                 /* Print ACL entries in the domain. */
1456                 down_read(&tomoyo_domain_acl_info_list_lock);
1457                 list_for_each_cookie(apos, head->read_var2,
1458                                      &domain->acl_info_list) {
1459                         struct tomoyo_acl_info *ptr
1460                                 = list_entry(apos, struct tomoyo_acl_info,
1461                                              list);
1462                         done = tomoyo_print_entry(head, ptr);
1463                         if (!done)
1464                                 break;
1465                 }
1466                 up_read(&tomoyo_domain_acl_info_list_lock);
1467                 if (!done)
1468                         break;
1469                 head->read_step = 3;
1470 tail_mark:
1471                 done = tomoyo_io_printf(head, "\n");
1472                 if (!done)
1473                         break;
1474                 head->read_step = 1;
1475                 if (head->read_single_domain)
1476                         break;
1477         }
1478         up_read(&tomoyo_domain_list_lock);
1479         head->read_eof = done;
1480         return 0;
1481 }
1482
1483 /**
1484  * tomoyo_write_domain_profile - Assign profile for specified domain.
1485  *
1486  * @head: Pointer to "struct tomoyo_io_buffer".
1487  *
1488  * Returns 0 on success, -EINVAL otherwise.
1489  *
1490  * This is equivalent to doing
1491  *
1492  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1493  *     /usr/lib/ccs/loadpolicy -d
1494  */
1495 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1496 {
1497         char *data = head->write_buf;
1498         char *cp = strchr(data, ' ');
1499         struct tomoyo_domain_info *domain;
1500         unsigned long profile;
1501
1502         if (!cp)
1503                 return -EINVAL;
1504         *cp = '\0';
1505         down_read(&tomoyo_domain_list_lock);
1506         domain = tomoyo_find_domain(cp + 1);
1507         up_read(&tomoyo_domain_list_lock);
1508         if (strict_strtoul(data, 10, &profile))
1509                 return -EINVAL;
1510         if (domain && profile < TOMOYO_MAX_PROFILES
1511             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1512                 domain->profile = (u8) profile;
1513         return 0;
1514 }
1515
1516 /**
1517  * tomoyo_read_domain_profile - Read only domainname and profile.
1518  *
1519  * @head: Pointer to "struct tomoyo_io_buffer".
1520  *
1521  * Returns list of profile number and domainname pairs.
1522  *
1523  * This is equivalent to doing
1524  *
1525  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1526  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1527  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1528  *     print $2 " " domainname; domainname = ""; } } ; '
1529  */
1530 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1531 {
1532         struct list_head *pos;
1533         bool done = true;
1534
1535         if (head->read_eof)
1536                 return 0;
1537         down_read(&tomoyo_domain_list_lock);
1538         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1539                 struct tomoyo_domain_info *domain;
1540                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1541                 if (domain->is_deleted)
1542                         continue;
1543                 done = tomoyo_io_printf(head, "%u %s\n", domain->profile,
1544                                         domain->domainname->name);
1545                 if (!done)
1546                         break;
1547         }
1548         up_read(&tomoyo_domain_list_lock);
1549         head->read_eof = done;
1550         return 0;
1551 }
1552
1553 /**
1554  * tomoyo_write_pid: Specify PID to obtain domainname.
1555  *
1556  * @head: Pointer to "struct tomoyo_io_buffer".
1557  *
1558  * Returns 0.
1559  */
1560 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1561 {
1562         unsigned long pid;
1563         /* No error check. */
1564         strict_strtoul(head->write_buf, 10, &pid);
1565         head->read_step = (int) pid;
1566         head->read_eof = false;
1567         return 0;
1568 }
1569
1570 /**
1571  * tomoyo_read_pid - Get domainname of the specified PID.
1572  *
1573  * @head: Pointer to "struct tomoyo_io_buffer".
1574  *
1575  * Returns the domainname which the specified PID is in on success,
1576  * empty string otherwise.
1577  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1578  * using read()/write() interface rather than sysctl() interface.
1579  */
1580 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1581 {
1582         if (head->read_avail == 0 && !head->read_eof) {
1583                 const int pid = head->read_step;
1584                 struct task_struct *p;
1585                 struct tomoyo_domain_info *domain = NULL;
1586                 read_lock(&tasklist_lock);
1587                 p = find_task_by_vpid(pid);
1588                 if (p)
1589                         domain = tomoyo_real_domain(p);
1590                 read_unlock(&tasklist_lock);
1591                 if (domain)
1592                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1593                                          domain->domainname->name);
1594                 head->read_eof = true;
1595         }
1596         return 0;
1597 }
1598
1599 /**
1600  * tomoyo_write_exception_policy - Write exception policy.
1601  *
1602  * @head: Pointer to "struct tomoyo_io_buffer".
1603  *
1604  * Returns 0 on success, negative value otherwise.
1605  */
1606 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1607 {
1608         char *data = head->write_buf;
1609         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1610
1611         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1612                 return tomoyo_write_domain_keeper_policy(data, false,
1613                                                          is_delete);
1614         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1615                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1616         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1617                 return tomoyo_write_domain_initializer_policy(data, false,
1618                                                               is_delete);
1619         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1620                 return tomoyo_write_domain_initializer_policy(data, true,
1621                                                               is_delete);
1622         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1623                 return tomoyo_write_alias_policy(data, is_delete);
1624         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1625                 return tomoyo_write_globally_readable_policy(data, is_delete);
1626         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1627                 return tomoyo_write_pattern_policy(data, is_delete);
1628         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1629                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1630         return -EINVAL;
1631 }
1632
1633 /**
1634  * tomoyo_read_exception_policy - Read exception policy.
1635  *
1636  * @head: Pointer to "struct tomoyo_io_buffer".
1637  *
1638  * Returns 0 on success, -EINVAL otherwise.
1639  */
1640 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1641 {
1642         if (!head->read_eof) {
1643                 switch (head->read_step) {
1644                 case 0:
1645                         head->read_var2 = NULL;
1646                         head->read_step = 1;
1647                 case 1:
1648                         if (!tomoyo_read_domain_keeper_policy(head))
1649                                 break;
1650                         head->read_var2 = NULL;
1651                         head->read_step = 2;
1652                 case 2:
1653                         if (!tomoyo_read_globally_readable_policy(head))
1654                                 break;
1655                         head->read_var2 = NULL;
1656                         head->read_step = 3;
1657                 case 3:
1658                         head->read_var2 = NULL;
1659                         head->read_step = 4;
1660                 case 4:
1661                         if (!tomoyo_read_domain_initializer_policy(head))
1662                                 break;
1663                         head->read_var2 = NULL;
1664                         head->read_step = 5;
1665                 case 5:
1666                         if (!tomoyo_read_alias_policy(head))
1667                                 break;
1668                         head->read_var2 = NULL;
1669                         head->read_step = 6;
1670                 case 6:
1671                         head->read_var2 = NULL;
1672                         head->read_step = 7;
1673                 case 7:
1674                         if (!tomoyo_read_file_pattern(head))
1675                                 break;
1676                         head->read_var2 = NULL;
1677                         head->read_step = 8;
1678                 case 8:
1679                         if (!tomoyo_read_no_rewrite_policy(head))
1680                                 break;
1681                         head->read_var2 = NULL;
1682                         head->read_step = 9;
1683                 case 9:
1684                         head->read_eof = true;
1685                         break;
1686                 default:
1687                         return -EINVAL;
1688                 }
1689         }
1690         return 0;
1691 }
1692
1693 /* path to policy loader */
1694 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1695
1696 /**
1697  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1698  *
1699  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1700  */
1701 static bool tomoyo_policy_loader_exists(void)
1702 {
1703         /*
1704          * Don't activate MAC if the policy loader doesn't exist.
1705          * If the initrd includes /sbin/init but real-root-dev has not
1706          * mounted on / yet, activating MAC will block the system since
1707          * policies are not loaded yet.
1708          * Thus, let do_execve() call this function everytime.
1709          */
1710         struct path path;
1711
1712         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
1713                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1714                        "since %s doesn't exist.\n", tomoyo_loader);
1715                 return false;
1716         }
1717         path_put(&path);
1718         return true;
1719 }
1720
1721 /**
1722  * tomoyo_load_policy - Run external policy loader to load policy.
1723  *
1724  * @filename: The program about to start.
1725  *
1726  * This function checks whether @filename is /sbin/init , and if so
1727  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1728  * and then continues invocation of /sbin/init.
1729  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1730  * writes to /sys/kernel/security/tomoyo/ interfaces.
1731  *
1732  * Returns nothing.
1733  */
1734 void tomoyo_load_policy(const char *filename)
1735 {
1736         char *argv[2];
1737         char *envp[3];
1738
1739         if (tomoyo_policy_loaded)
1740                 return;
1741         /*
1742          * Check filename is /sbin/init or /sbin/tomoyo-start.
1743          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1744          * be passed.
1745          * You can create /sbin/tomoyo-start by
1746          * "ln -s /bin/true /sbin/tomoyo-start".
1747          */
1748         if (strcmp(filename, "/sbin/init") &&
1749             strcmp(filename, "/sbin/tomoyo-start"))
1750                 return;
1751         if (!tomoyo_policy_loader_exists())
1752                 return;
1753
1754         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1755                tomoyo_loader);
1756         argv[0] = (char *) tomoyo_loader;
1757         argv[1] = NULL;
1758         envp[0] = "HOME=/";
1759         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1760         envp[2] = NULL;
1761         call_usermodehelper(argv[0], argv, envp, 1);
1762
1763         printk(KERN_INFO "TOMOYO: 2.2.0   2009/04/01\n");
1764         printk(KERN_INFO "Mandatory Access Control activated.\n");
1765         tomoyo_policy_loaded = true;
1766         { /* Check all profiles currently assigned to domains are defined. */
1767                 struct tomoyo_domain_info *domain;
1768                 down_read(&tomoyo_domain_list_lock);
1769                 list_for_each_entry(domain, &tomoyo_domain_list, list) {
1770                         const u8 profile = domain->profile;
1771                         if (tomoyo_profile_ptr[profile])
1772                                 continue;
1773                         panic("Profile %u (used by '%s') not defined.\n",
1774                               profile, domain->domainname->name);
1775                 }
1776                 up_read(&tomoyo_domain_list_lock);
1777         }
1778 }
1779
1780 /**
1781  * tomoyo_read_version: Get version.
1782  *
1783  * @head: Pointer to "struct tomoyo_io_buffer".
1784  *
1785  * Returns version information.
1786  */
1787 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1788 {
1789         if (!head->read_eof) {
1790                 tomoyo_io_printf(head, "2.2.0");
1791                 head->read_eof = true;
1792         }
1793         return 0;
1794 }
1795
1796 /**
1797  * tomoyo_read_self_domain - Get the current process's domainname.
1798  *
1799  * @head: Pointer to "struct tomoyo_io_buffer".
1800  *
1801  * Returns the current process's domainname.
1802  */
1803 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1804 {
1805         if (!head->read_eof) {
1806                 /*
1807                  * tomoyo_domain()->domainname != NULL
1808                  * because every process belongs to a domain and
1809                  * the domain's name cannot be NULL.
1810                  */
1811                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1812                 head->read_eof = true;
1813         }
1814         return 0;
1815 }
1816
1817 /**
1818  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1819  *
1820  * @type: Type of interface.
1821  * @file: Pointer to "struct file".
1822  *
1823  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1824  */
1825 static int tomoyo_open_control(const u8 type, struct file *file)
1826 {
1827         struct tomoyo_io_buffer *head = tomoyo_alloc(sizeof(*head));
1828
1829         if (!head)
1830                 return -ENOMEM;
1831         mutex_init(&head->io_sem);
1832         switch (type) {
1833         case TOMOYO_DOMAINPOLICY:
1834                 /* /sys/kernel/security/tomoyo/domain_policy */
1835                 head->write = tomoyo_write_domain_policy;
1836                 head->read = tomoyo_read_domain_policy;
1837                 break;
1838         case TOMOYO_EXCEPTIONPOLICY:
1839                 /* /sys/kernel/security/tomoyo/exception_policy */
1840                 head->write = tomoyo_write_exception_policy;
1841                 head->read = tomoyo_read_exception_policy;
1842                 break;
1843         case TOMOYO_SELFDOMAIN:
1844                 /* /sys/kernel/security/tomoyo/self_domain */
1845                 head->read = tomoyo_read_self_domain;
1846                 break;
1847         case TOMOYO_DOMAIN_STATUS:
1848                 /* /sys/kernel/security/tomoyo/.domain_status */
1849                 head->write = tomoyo_write_domain_profile;
1850                 head->read = tomoyo_read_domain_profile;
1851                 break;
1852         case TOMOYO_PROCESS_STATUS:
1853                 /* /sys/kernel/security/tomoyo/.process_status */
1854                 head->write = tomoyo_write_pid;
1855                 head->read = tomoyo_read_pid;
1856                 break;
1857         case TOMOYO_VERSION:
1858                 /* /sys/kernel/security/tomoyo/version */
1859                 head->read = tomoyo_read_version;
1860                 head->readbuf_size = 128;
1861                 break;
1862         case TOMOYO_MEMINFO:
1863                 /* /sys/kernel/security/tomoyo/meminfo */
1864                 head->write = tomoyo_write_memory_quota;
1865                 head->read = tomoyo_read_memory_counter;
1866                 head->readbuf_size = 512;
1867                 break;
1868         case TOMOYO_PROFILE:
1869                 /* /sys/kernel/security/tomoyo/profile */
1870                 head->write = tomoyo_write_profile;
1871                 head->read = tomoyo_read_profile;
1872                 break;
1873         case TOMOYO_MANAGER:
1874                 /* /sys/kernel/security/tomoyo/manager */
1875                 head->write = tomoyo_write_manager_policy;
1876                 head->read = tomoyo_read_manager_policy;
1877                 break;
1878         }
1879         if (!(file->f_mode & FMODE_READ)) {
1880                 /*
1881                  * No need to allocate read_buf since it is not opened
1882                  * for reading.
1883                  */
1884                 head->read = NULL;
1885         } else {
1886                 if (!head->readbuf_size)
1887                         head->readbuf_size = 4096 * 2;
1888                 head->read_buf = tomoyo_alloc(head->readbuf_size);
1889                 if (!head->read_buf) {
1890                         tomoyo_free(head);
1891                         return -ENOMEM;
1892                 }
1893         }
1894         if (!(file->f_mode & FMODE_WRITE)) {
1895                 /*
1896                  * No need to allocate write_buf since it is not opened
1897                  * for writing.
1898                  */
1899                 head->write = NULL;
1900         } else if (head->write) {
1901                 head->writebuf_size = 4096 * 2;
1902                 head->write_buf = tomoyo_alloc(head->writebuf_size);
1903                 if (!head->write_buf) {
1904                         tomoyo_free(head->read_buf);
1905                         tomoyo_free(head);
1906                         return -ENOMEM;
1907                 }
1908         }
1909         file->private_data = head;
1910         /*
1911          * Call the handler now if the file is
1912          * /sys/kernel/security/tomoyo/self_domain
1913          * so that the user can use
1914          * cat < /sys/kernel/security/tomoyo/self_domain"
1915          * to know the current process's domainname.
1916          */
1917         if (type == TOMOYO_SELFDOMAIN)
1918                 tomoyo_read_control(file, NULL, 0);
1919         return 0;
1920 }
1921
1922 /**
1923  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
1924  *
1925  * @file:       Pointer to "struct file".
1926  * @buffer:     Poiner to buffer to write to.
1927  * @buffer_len: Size of @buffer.
1928  *
1929  * Returns bytes read on success, negative value otherwise.
1930  */
1931 static int tomoyo_read_control(struct file *file, char __user *buffer,
1932                                const int buffer_len)
1933 {
1934         int len = 0;
1935         struct tomoyo_io_buffer *head = file->private_data;
1936         char *cp;
1937
1938         if (!head->read)
1939                 return -ENOSYS;
1940         if (mutex_lock_interruptible(&head->io_sem))
1941                 return -EINTR;
1942         /* Call the policy handler. */
1943         len = head->read(head);
1944         if (len < 0)
1945                 goto out;
1946         /* Write to buffer. */
1947         len = head->read_avail;
1948         if (len > buffer_len)
1949                 len = buffer_len;
1950         if (!len)
1951                 goto out;
1952         /* head->read_buf changes by some functions. */
1953         cp = head->read_buf;
1954         if (copy_to_user(buffer, cp, len)) {
1955                 len = -EFAULT;
1956                 goto out;
1957         }
1958         head->read_avail -= len;
1959         memmove(cp, cp + len, head->read_avail);
1960  out:
1961         mutex_unlock(&head->io_sem);
1962         return len;
1963 }
1964
1965 /**
1966  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
1967  *
1968  * @file:       Pointer to "struct file".
1969  * @buffer:     Pointer to buffer to read from.
1970  * @buffer_len: Size of @buffer.
1971  *
1972  * Returns @buffer_len on success, negative value otherwise.
1973  */
1974 static int tomoyo_write_control(struct file *file, const char __user *buffer,
1975                                 const int buffer_len)
1976 {
1977         struct tomoyo_io_buffer *head = file->private_data;
1978         int error = buffer_len;
1979         int avail_len = buffer_len;
1980         char *cp0 = head->write_buf;
1981
1982         if (!head->write)
1983                 return -ENOSYS;
1984         if (!access_ok(VERIFY_READ, buffer, buffer_len))
1985                 return -EFAULT;
1986         /* Don't allow updating policies by non manager programs. */
1987         if (head->write != tomoyo_write_pid &&
1988             head->write != tomoyo_write_domain_policy &&
1989             !tomoyo_is_policy_manager())
1990                 return -EPERM;
1991         if (mutex_lock_interruptible(&head->io_sem))
1992                 return -EINTR;
1993         /* Read a line and dispatch it to the policy handler. */
1994         while (avail_len > 0) {
1995                 char c;
1996                 if (head->write_avail >= head->writebuf_size - 1) {
1997                         error = -ENOMEM;
1998                         break;
1999                 } else if (get_user(c, buffer)) {
2000                         error = -EFAULT;
2001                         break;
2002                 }
2003                 buffer++;
2004                 avail_len--;
2005                 cp0[head->write_avail++] = c;
2006                 if (c != '\n')
2007                         continue;
2008                 cp0[head->write_avail - 1] = '\0';
2009                 head->write_avail = 0;
2010                 tomoyo_normalize_line(cp0);
2011                 head->write(head);
2012         }
2013         mutex_unlock(&head->io_sem);
2014         return error;
2015 }
2016
2017 /**
2018  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2019  *
2020  * @file: Pointer to "struct file".
2021  *
2022  * Releases memory and returns 0.
2023  */
2024 static int tomoyo_close_control(struct file *file)
2025 {
2026         struct tomoyo_io_buffer *head = file->private_data;
2027
2028         /* Release memory used for policy I/O. */
2029         tomoyo_free(head->read_buf);
2030         head->read_buf = NULL;
2031         tomoyo_free(head->write_buf);
2032         head->write_buf = NULL;
2033         tomoyo_free(head);
2034         head = NULL;
2035         file->private_data = NULL;
2036         return 0;
2037 }
2038
2039 /**
2040  * tomoyo_alloc_acl_element - Allocate permanent memory for ACL entry.
2041  *
2042  * @acl_type:  Type of ACL entry.
2043  *
2044  * Returns pointer to the ACL entry on success, NULL otherwise.
2045  */
2046 void *tomoyo_alloc_acl_element(const u8 acl_type)
2047 {
2048         int len;
2049         struct tomoyo_acl_info *ptr;
2050
2051         switch (acl_type) {
2052         case TOMOYO_TYPE_SINGLE_PATH_ACL:
2053                 len = sizeof(struct tomoyo_single_path_acl_record);
2054                 break;
2055         case TOMOYO_TYPE_DOUBLE_PATH_ACL:
2056                 len = sizeof(struct tomoyo_double_path_acl_record);
2057                 break;
2058         default:
2059                 return NULL;
2060         }
2061         ptr = tomoyo_alloc_element(len);
2062         if (!ptr)
2063                 return NULL;
2064         ptr->type = acl_type;
2065         return ptr;
2066 }
2067
2068 /**
2069  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2070  *
2071  * @inode: Pointer to "struct inode".
2072  * @file:  Pointer to "struct file".
2073  *
2074  * Returns 0 on success, negative value otherwise.
2075  */
2076 static int tomoyo_open(struct inode *inode, struct file *file)
2077 {
2078         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2079                 - ((u8 *) NULL);
2080         return tomoyo_open_control(key, file);
2081 }
2082
2083 /**
2084  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2085  *
2086  * @inode: Pointer to "struct inode".
2087  * @file:  Pointer to "struct file".
2088  *
2089  * Returns 0 on success, negative value otherwise.
2090  */
2091 static int tomoyo_release(struct inode *inode, struct file *file)
2092 {
2093         return tomoyo_close_control(file);
2094 }
2095
2096 /**
2097  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2098  *
2099  * @file:  Pointer to "struct file".
2100  * @buf:   Pointer to buffer.
2101  * @count: Size of @buf.
2102  * @ppos:  Unused.
2103  *
2104  * Returns bytes read on success, negative value otherwise.
2105  */
2106 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2107                            loff_t *ppos)
2108 {
2109         return tomoyo_read_control(file, buf, count);
2110 }
2111
2112 /**
2113  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2114  *
2115  * @file:  Pointer to "struct file".
2116  * @buf:   Pointer to buffer.
2117  * @count: Size of @buf.
2118  * @ppos:  Unused.
2119  *
2120  * Returns @count on success, negative value otherwise.
2121  */
2122 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2123                             size_t count, loff_t *ppos)
2124 {
2125         return tomoyo_write_control(file, buf, count);
2126 }
2127
2128 /* Operations for /sys/kernel/security/tomoyo/ interface. */
2129 static const struct file_operations tomoyo_operations = {
2130         .open    = tomoyo_open,
2131         .release = tomoyo_release,
2132         .read    = tomoyo_read,
2133         .write   = tomoyo_write,
2134 };
2135
2136 /**
2137  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2138  *
2139  * @name:   The name of the interface file.
2140  * @mode:   The permission of the interface file.
2141  * @parent: The parent directory.
2142  * @key:    Type of interface.
2143  *
2144  * Returns nothing.
2145  */
2146 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2147                                        struct dentry *parent, const u8 key)
2148 {
2149         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2150                                &tomoyo_operations);
2151 }
2152
2153 /**
2154  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2155  *
2156  * Returns 0.
2157  */
2158 static int __init tomoyo_initerface_init(void)
2159 {
2160         struct dentry *tomoyo_dir;
2161
2162         /* Don't create securityfs entries unless registered. */
2163         if (current_cred()->security != &tomoyo_kernel_domain)
2164                 return 0;
2165
2166         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2167         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2168                             TOMOYO_DOMAINPOLICY);
2169         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2170                             TOMOYO_EXCEPTIONPOLICY);
2171         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2172                             TOMOYO_SELFDOMAIN);
2173         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2174                             TOMOYO_DOMAIN_STATUS);
2175         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2176                             TOMOYO_PROCESS_STATUS);
2177         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2178                             TOMOYO_MEMINFO);
2179         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2180                             TOMOYO_PROFILE);
2181         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2182                             TOMOYO_MANAGER);
2183         tomoyo_create_entry("version",          0400, tomoyo_dir,
2184                             TOMOYO_VERSION);
2185         return 0;
2186 }
2187
2188 fs_initcall(tomoyo_initerface_init);