a44f655b3913cc2e9c0938a9e0e44399c6181564
[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->const_len = tomoyo_const_part_length(name);
432         ptr->is_dir = len && (name[len - 1] == '/');
433         ptr->is_patterned = (ptr->const_len < len);
434         ptr->hash = full_name_hash(name, len);
435         ptr->depth = tomoyo_path_depth(name);
436 }
437
438 /**
439  * tomoyo_file_matches_to_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_to_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_to_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_to_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_to_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_to_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_to_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_to_pattern2(filename, filename_end,
592                                                  pattern_start, pattern_end);
593         return first ? result : !result;
594 }
595
596 /**
597  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
598  * @filename: The filename to check.
599  * @pattern:  The pattern to compare.
600  *
601  * Returns true if matches, false otherwise.
602  *
603  * The following patterns are available.
604  *   \\     \ itself.
605  *   \ooo   Octal representation of a byte.
606  *   \*     More than or equals to 0 character other than '/'.
607  *   \@     More than or equals to 0 character other than '/' or '.'.
608  *   \?     1 byte character other than '/'.
609  *   \$     More than or equals to 1 decimal digit.
610  *   \+     1 decimal digit.
611  *   \X     More than or equals to 1 hexadecimal digit.
612  *   \x     1 hexadecimal digit.
613  *   \A     More than or equals to 1 alphabet character.
614  *   \a     1 alphabet character.
615  *   \-     Subtraction operator.
616  */
617 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
618                                  const struct tomoyo_path_info *pattern)
619 {
620         /*
621           if (!filename || !pattern)
622           return false;
623         */
624         const char *f = filename->name;
625         const char *p = pattern->name;
626         const int len = pattern->const_len;
627
628         /* If @pattern doesn't contain pattern, I can use strcmp(). */
629         if (!pattern->is_patterned)
630                 return !tomoyo_pathcmp(filename, pattern);
631         /* Dont compare if the number of '/' differs. */
632         if (filename->depth != pattern->depth)
633                 return false;
634         /* Compare the initial length without patterns. */
635         if (strncmp(f, p, len))
636                 return false;
637         f += len;
638         p += len;
639         /* Main loop. Compare each directory component. */
640         while (*f && *p) {
641                 const char *f_delimiter = strchr(f, '/');
642                 const char *p_delimiter = strchr(p, '/');
643                 if (!f_delimiter)
644                         f_delimiter = f + strlen(f);
645                 if (!p_delimiter)
646                         p_delimiter = p + strlen(p);
647                 if (!tomoyo_file_matches_to_pattern(f, f_delimiter,
648                                                     p, p_delimiter))
649                         return false;
650                 f = f_delimiter;
651                 if (*f)
652                         f++;
653                 p = p_delimiter;
654                 if (*p)
655                         p++;
656         }
657         /* Ignore trailing "\*" and "\@" in @pattern. */
658         while (*p == '\\' &&
659                (*(p + 1) == '*' || *(p + 1) == '@'))
660                 p += 2;
661         return !*f && !*p;
662 }
663
664 /**
665  * tomoyo_io_printf - Transactional printf() to "struct tomoyo_io_buffer" structure.
666  *
667  * @head: Pointer to "struct tomoyo_io_buffer".
668  * @fmt:  The printf()'s format string, followed by parameters.
669  *
670  * Returns true if output was written, false otherwise.
671  *
672  * The snprintf() will truncate, but tomoyo_io_printf() won't.
673  */
674 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
675 {
676         va_list args;
677         int len;
678         int pos = head->read_avail;
679         int size = head->readbuf_size - pos;
680
681         if (size <= 0)
682                 return false;
683         va_start(args, fmt);
684         len = vsnprintf(head->read_buf + pos, size, fmt, args);
685         va_end(args);
686         if (pos + len >= head->readbuf_size)
687                 return false;
688         head->read_avail += len;
689         return true;
690 }
691
692 /**
693  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
694  *
695  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
696  *
697  * This function uses tomoyo_alloc(), so the caller must call tomoyo_free()
698  * if this function didn't return NULL.
699  */
700 static const char *tomoyo_get_exe(void)
701 {
702         struct mm_struct *mm = current->mm;
703         struct vm_area_struct *vma;
704         const char *cp = NULL;
705
706         if (!mm)
707                 return NULL;
708         down_read(&mm->mmap_sem);
709         for (vma = mm->mmap; vma; vma = vma->vm_next) {
710                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
711                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
712                         break;
713                 }
714         }
715         up_read(&mm->mmap_sem);
716         return cp;
717 }
718
719 /**
720  * tomoyo_get_msg - Get warning message.
721  *
722  * @is_enforce: Is it enforcing mode?
723  *
724  * Returns "ERROR" or "WARNING".
725  */
726 const char *tomoyo_get_msg(const bool is_enforce)
727 {
728         if (is_enforce)
729                 return "ERROR";
730         else
731                 return "WARNING";
732 }
733
734 /**
735  * tomoyo_check_flags - Check mode for specified functionality.
736  *
737  * @domain: Pointer to "struct tomoyo_domain_info".
738  * @index:  The functionality to check mode.
739  *
740  * TOMOYO checks only process context.
741  * This code disables TOMOYO's enforcement in case the function is called from
742  * interrupt context.
743  */
744 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
745                                 const u8 index)
746 {
747         const u8 profile = domain->profile;
748
749         if (WARN_ON(in_interrupt()))
750                 return 0;
751         return tomoyo_policy_loaded && index < TOMOYO_MAX_CONTROL_INDEX
752 #if TOMOYO_MAX_PROFILES != 256
753                 && profile < TOMOYO_MAX_PROFILES
754 #endif
755                 && tomoyo_profile_ptr[profile] ?
756                 tomoyo_profile_ptr[profile]->value[index] : 0;
757 }
758
759 /**
760  * tomoyo_verbose_mode - Check whether TOMOYO is verbose mode.
761  *
762  * @domain: Pointer to "struct tomoyo_domain_info".
763  *
764  * Returns true if domain policy violation warning should be printed to
765  * console.
766  */
767 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain)
768 {
769         return tomoyo_check_flags(domain, TOMOYO_VERBOSE) != 0;
770 }
771
772 /**
773  * tomoyo_domain_quota_is_ok - Check for domain's quota.
774  *
775  * @domain: Pointer to "struct tomoyo_domain_info".
776  *
777  * Returns true if the domain is not exceeded quota, false otherwise.
778  */
779 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
780 {
781         unsigned int count = 0;
782         struct tomoyo_acl_info *ptr;
783
784         if (!domain)
785                 return true;
786         down_read(&tomoyo_domain_acl_info_list_lock);
787         list_for_each_entry(ptr, &domain->acl_info_list, list) {
788                 if (ptr->type & TOMOYO_ACL_DELETED)
789                         continue;
790                 switch (tomoyo_acl_type2(ptr)) {
791                         struct tomoyo_single_path_acl_record *acl1;
792                         struct tomoyo_double_path_acl_record *acl2;
793                         u16 perm;
794                 case TOMOYO_TYPE_SINGLE_PATH_ACL:
795                         acl1 = container_of(ptr,
796                                     struct tomoyo_single_path_acl_record,
797                                             head);
798                         perm = acl1->perm;
799                         if (perm & (1 << TOMOYO_TYPE_EXECUTE_ACL))
800                                 count++;
801                         if (perm &
802                             ((1 << TOMOYO_TYPE_READ_ACL) |
803                              (1 << TOMOYO_TYPE_WRITE_ACL)))
804                                 count++;
805                         if (perm & (1 << TOMOYO_TYPE_CREATE_ACL))
806                                 count++;
807                         if (perm & (1 << TOMOYO_TYPE_UNLINK_ACL))
808                                 count++;
809                         if (perm & (1 << TOMOYO_TYPE_MKDIR_ACL))
810                                 count++;
811                         if (perm & (1 << TOMOYO_TYPE_RMDIR_ACL))
812                                 count++;
813                         if (perm & (1 << TOMOYO_TYPE_MKFIFO_ACL))
814                                 count++;
815                         if (perm & (1 << TOMOYO_TYPE_MKSOCK_ACL))
816                                 count++;
817                         if (perm & (1 << TOMOYO_TYPE_MKBLOCK_ACL))
818                                 count++;
819                         if (perm & (1 << TOMOYO_TYPE_MKCHAR_ACL))
820                                 count++;
821                         if (perm & (1 << TOMOYO_TYPE_TRUNCATE_ACL))
822                                 count++;
823                         if (perm & (1 << TOMOYO_TYPE_SYMLINK_ACL))
824                                 count++;
825                         if (perm & (1 << TOMOYO_TYPE_REWRITE_ACL))
826                                 count++;
827                         break;
828                 case TOMOYO_TYPE_DOUBLE_PATH_ACL:
829                         acl2 = container_of(ptr,
830                                     struct tomoyo_double_path_acl_record,
831                                             head);
832                         perm = acl2->perm;
833                         if (perm & (1 << TOMOYO_TYPE_LINK_ACL))
834                                 count++;
835                         if (perm & (1 << TOMOYO_TYPE_RENAME_ACL))
836                                 count++;
837                         break;
838                 }
839         }
840         up_read(&tomoyo_domain_acl_info_list_lock);
841         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
842                 return true;
843         if (!domain->quota_warned) {
844                 domain->quota_warned = true;
845                 printk(KERN_WARNING "TOMOYO-WARNING: "
846                        "Domain '%s' has so many ACLs to hold. "
847                        "Stopped learning mode.\n", domain->domainname->name);
848         }
849         return false;
850 }
851
852 /**
853  * tomoyo_find_or_assign_new_profile - Create a new profile.
854  *
855  * @profile: Profile number to create.
856  *
857  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
858  */
859 static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned
860                                                                 int profile)
861 {
862         static DEFINE_MUTEX(lock);
863         struct tomoyo_profile *ptr = NULL;
864         int i;
865
866         if (profile >= TOMOYO_MAX_PROFILES)
867                 return NULL;
868         mutex_lock(&lock);
869         ptr = tomoyo_profile_ptr[profile];
870         if (ptr)
871                 goto ok;
872         ptr = tomoyo_alloc_element(sizeof(*ptr));
873         if (!ptr)
874                 goto ok;
875         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
876                 ptr->value[i] = tomoyo_control_array[i].current_value;
877         mb(); /* Avoid out-of-order execution. */
878         tomoyo_profile_ptr[profile] = ptr;
879  ok:
880         mutex_unlock(&lock);
881         return ptr;
882 }
883
884 /**
885  * tomoyo_write_profile - Write to profile table.
886  *
887  * @head: Pointer to "struct tomoyo_io_buffer".
888  *
889  * Returns 0 on success, negative value otherwise.
890  */
891 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
892 {
893         char *data = head->write_buf;
894         unsigned int i;
895         unsigned int value;
896         char *cp;
897         struct tomoyo_profile *profile;
898         unsigned long num;
899
900         cp = strchr(data, '-');
901         if (cp)
902                 *cp = '\0';
903         if (strict_strtoul(data, 10, &num))
904                 return -EINVAL;
905         if (cp)
906                 data = cp + 1;
907         profile = tomoyo_find_or_assign_new_profile(num);
908         if (!profile)
909                 return -EINVAL;
910         cp = strchr(data, '=');
911         if (!cp)
912                 return -EINVAL;
913         *cp = '\0';
914         if (!strcmp(data, "COMMENT")) {
915                 profile->comment = tomoyo_save_name(cp + 1);
916                 return 0;
917         }
918         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
919                 if (strcmp(data, tomoyo_control_array[i].keyword))
920                         continue;
921                 if (sscanf(cp + 1, "%u", &value) != 1) {
922                         int j;
923                         const char **modes;
924                         switch (i) {
925                         case TOMOYO_VERBOSE:
926                                 modes = tomoyo_mode_2;
927                                 break;
928                         default:
929                                 modes = tomoyo_mode_4;
930                                 break;
931                         }
932                         for (j = 0; j < 4; j++) {
933                                 if (strcmp(cp + 1, modes[j]))
934                                         continue;
935                                 value = j;
936                                 break;
937                         }
938                         if (j == 4)
939                                 return -EINVAL;
940                 } else if (value > tomoyo_control_array[i].max_value) {
941                         value = tomoyo_control_array[i].max_value;
942                 }
943                 profile->value[i] = value;
944                 return 0;
945         }
946         return -EINVAL;
947 }
948
949 /**
950  * tomoyo_read_profile - Read from profile table.
951  *
952  * @head: Pointer to "struct tomoyo_io_buffer".
953  *
954  * Returns 0.
955  */
956 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
957 {
958         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
959         int step;
960
961         if (head->read_eof)
962                 return 0;
963         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
964              step++) {
965                 const u8 index = step / total;
966                 u8 type = step % total;
967                 const struct tomoyo_profile *profile
968                         = tomoyo_profile_ptr[index];
969                 head->read_step = step;
970                 if (!profile)
971                         continue;
972                 if (!type) { /* Print profile' comment tag. */
973                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
974                                               index, profile->comment ?
975                                               profile->comment->name : ""))
976                                 break;
977                         continue;
978                 }
979                 type--;
980                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
981                         const unsigned int value = profile->value[type];
982                         const char **modes = NULL;
983                         const char *keyword
984                                 = tomoyo_control_array[type].keyword;
985                         switch (tomoyo_control_array[type].max_value) {
986                         case 3:
987                                 modes = tomoyo_mode_4;
988                                 break;
989                         case 1:
990                                 modes = tomoyo_mode_2;
991                                 break;
992                         }
993                         if (modes) {
994                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
995                                                       keyword, modes[value]))
996                                         break;
997                         } else {
998                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
999                                                       keyword, value))
1000                                         break;
1001                         }
1002                 }
1003         }
1004         if (step == TOMOYO_MAX_PROFILES * total)
1005                 head->read_eof = true;
1006         return 0;
1007 }
1008
1009 /* Structure for policy manager. */
1010 struct tomoyo_policy_manager_entry {
1011         struct list_head list;
1012         /* A path to program or a domainname. */
1013         const struct tomoyo_path_info *manager;
1014         bool is_domain;  /* True if manager is a domainname. */
1015         bool is_deleted; /* True if this entry is deleted. */
1016 };
1017
1018 /* The list for "struct tomoyo_policy_manager_entry". */
1019 static LIST_HEAD(tomoyo_policy_manager_list);
1020 static DECLARE_RWSEM(tomoyo_policy_manager_list_lock);
1021
1022 /**
1023  * tomoyo_update_manager_entry - Add a manager entry.
1024  *
1025  * @manager:   The path to manager or the domainnamme.
1026  * @is_delete: True if it is a delete request.
1027  *
1028  * Returns 0 on success, negative value otherwise.
1029  */
1030 static int tomoyo_update_manager_entry(const char *manager,
1031                                        const bool is_delete)
1032 {
1033         struct tomoyo_policy_manager_entry *new_entry;
1034         struct tomoyo_policy_manager_entry *ptr;
1035         const struct tomoyo_path_info *saved_manager;
1036         int error = -ENOMEM;
1037         bool is_domain = false;
1038
1039         if (tomoyo_is_domain_def(manager)) {
1040                 if (!tomoyo_is_correct_domain(manager, __func__))
1041                         return -EINVAL;
1042                 is_domain = true;
1043         } else {
1044                 if (!tomoyo_is_correct_path(manager, 1, -1, -1, __func__))
1045                         return -EINVAL;
1046         }
1047         saved_manager = tomoyo_save_name(manager);
1048         if (!saved_manager)
1049                 return -ENOMEM;
1050         down_write(&tomoyo_policy_manager_list_lock);
1051         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1052                 if (ptr->manager != saved_manager)
1053                         continue;
1054                 ptr->is_deleted = is_delete;
1055                 error = 0;
1056                 goto out;
1057         }
1058         if (is_delete) {
1059                 error = -ENOENT;
1060                 goto out;
1061         }
1062         new_entry = tomoyo_alloc_element(sizeof(*new_entry));
1063         if (!new_entry)
1064                 goto out;
1065         new_entry->manager = saved_manager;
1066         new_entry->is_domain = is_domain;
1067         list_add_tail(&new_entry->list, &tomoyo_policy_manager_list);
1068         error = 0;
1069  out:
1070         up_write(&tomoyo_policy_manager_list_lock);
1071         return error;
1072 }
1073
1074 /**
1075  * tomoyo_write_manager_policy - Write manager policy.
1076  *
1077  * @head: Pointer to "struct tomoyo_io_buffer".
1078  *
1079  * Returns 0 on success, negative value otherwise.
1080  */
1081 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1082 {
1083         char *data = head->write_buf;
1084         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1085
1086         if (!strcmp(data, "manage_by_non_root")) {
1087                 tomoyo_manage_by_non_root = !is_delete;
1088                 return 0;
1089         }
1090         return tomoyo_update_manager_entry(data, is_delete);
1091 }
1092
1093 /**
1094  * tomoyo_read_manager_policy - Read manager policy.
1095  *
1096  * @head: Pointer to "struct tomoyo_io_buffer".
1097  *
1098  * Returns 0.
1099  */
1100 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1101 {
1102         struct list_head *pos;
1103         bool done = true;
1104
1105         if (head->read_eof)
1106                 return 0;
1107         down_read(&tomoyo_policy_manager_list_lock);
1108         list_for_each_cookie(pos, head->read_var2,
1109                              &tomoyo_policy_manager_list) {
1110                 struct tomoyo_policy_manager_entry *ptr;
1111                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1112                                  list);
1113                 if (ptr->is_deleted)
1114                         continue;
1115                 done = tomoyo_io_printf(head, "%s\n", ptr->manager->name);
1116                 if (!done)
1117                         break;
1118         }
1119         up_read(&tomoyo_policy_manager_list_lock);
1120         head->read_eof = done;
1121         return 0;
1122 }
1123
1124 /**
1125  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1126  *
1127  * Returns true if the current process is permitted to modify policy
1128  * via /sys/kernel/security/tomoyo/ interface.
1129  */
1130 static bool tomoyo_is_policy_manager(void)
1131 {
1132         struct tomoyo_policy_manager_entry *ptr;
1133         const char *exe;
1134         const struct task_struct *task = current;
1135         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1136         bool found = false;
1137
1138         if (!tomoyo_policy_loaded)
1139                 return true;
1140         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1141                 return false;
1142         down_read(&tomoyo_policy_manager_list_lock);
1143         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1144                 if (!ptr->is_deleted && ptr->is_domain
1145                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1146                         found = true;
1147                         break;
1148                 }
1149         }
1150         up_read(&tomoyo_policy_manager_list_lock);
1151         if (found)
1152                 return true;
1153         exe = tomoyo_get_exe();
1154         if (!exe)
1155                 return false;
1156         down_read(&tomoyo_policy_manager_list_lock);
1157         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1158                 if (!ptr->is_deleted && !ptr->is_domain
1159                     && !strcmp(exe, ptr->manager->name)) {
1160                         found = true;
1161                         break;
1162                 }
1163         }
1164         up_read(&tomoyo_policy_manager_list_lock);
1165         if (!found) { /* Reduce error messages. */
1166                 static pid_t last_pid;
1167                 const pid_t pid = current->pid;
1168                 if (last_pid != pid) {
1169                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1170                                "update policies.\n", domainname->name, exe);
1171                         last_pid = pid;
1172                 }
1173         }
1174         tomoyo_free(exe);
1175         return found;
1176 }
1177
1178 /**
1179  * tomoyo_is_select_one - Parse select command.
1180  *
1181  * @head: Pointer to "struct tomoyo_io_buffer".
1182  * @data: String to parse.
1183  *
1184  * Returns true on success, false otherwise.
1185  */
1186 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1187                                  const char *data)
1188 {
1189         unsigned int pid;
1190         struct tomoyo_domain_info *domain = NULL;
1191
1192         if (sscanf(data, "pid=%u", &pid) == 1) {
1193                 struct task_struct *p;
1194                 read_lock(&tasklist_lock);
1195                 p = find_task_by_vpid(pid);
1196                 if (p)
1197                         domain = tomoyo_real_domain(p);
1198                 read_unlock(&tasklist_lock);
1199         } else if (!strncmp(data, "domain=", 7)) {
1200                 if (tomoyo_is_domain_def(data + 7)) {
1201                         down_read(&tomoyo_domain_list_lock);
1202                         domain = tomoyo_find_domain(data + 7);
1203                         up_read(&tomoyo_domain_list_lock);
1204                 }
1205         } else
1206                 return false;
1207         head->write_var1 = domain;
1208         /* Accessing read_buf is safe because head->io_sem is held. */
1209         if (!head->read_buf)
1210                 return true; /* Do nothing if open(O_WRONLY). */
1211         head->read_avail = 0;
1212         tomoyo_io_printf(head, "# select %s\n", data);
1213         head->read_single_domain = true;
1214         head->read_eof = !domain;
1215         if (domain) {
1216                 struct tomoyo_domain_info *d;
1217                 head->read_var1 = NULL;
1218                 down_read(&tomoyo_domain_list_lock);
1219                 list_for_each_entry(d, &tomoyo_domain_list, list) {
1220                         if (d == domain)
1221                                 break;
1222                         head->read_var1 = &d->list;
1223                 }
1224                 up_read(&tomoyo_domain_list_lock);
1225                 head->read_var2 = NULL;
1226                 head->read_bit = 0;
1227                 head->read_step = 0;
1228                 if (domain->is_deleted)
1229                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1230         }
1231         return true;
1232 }
1233
1234 /**
1235  * tomoyo_write_domain_policy - Write domain policy.
1236  *
1237  * @head: Pointer to "struct tomoyo_io_buffer".
1238  *
1239  * Returns 0 on success, negative value otherwise.
1240  */
1241 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1242 {
1243         char *data = head->write_buf;
1244         struct tomoyo_domain_info *domain = head->write_var1;
1245         bool is_delete = false;
1246         bool is_select = false;
1247         unsigned int profile;
1248
1249         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1250                 is_delete = true;
1251         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1252                 is_select = true;
1253         if (is_select && tomoyo_is_select_one(head, data))
1254                 return 0;
1255         /* Don't allow updating policies by non manager programs. */
1256         if (!tomoyo_is_policy_manager())
1257                 return -EPERM;
1258         if (tomoyo_is_domain_def(data)) {
1259                 domain = NULL;
1260                 if (is_delete)
1261                         tomoyo_delete_domain(data);
1262                 else if (is_select) {
1263                         down_read(&tomoyo_domain_list_lock);
1264                         domain = tomoyo_find_domain(data);
1265                         up_read(&tomoyo_domain_list_lock);
1266                 } else
1267                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1268                 head->write_var1 = domain;
1269                 return 0;
1270         }
1271         if (!domain)
1272                 return -EINVAL;
1273
1274         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1275             && profile < TOMOYO_MAX_PROFILES) {
1276                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1277                         domain->profile = (u8) profile;
1278                 return 0;
1279         }
1280         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1281                 tomoyo_set_domain_flag(domain, is_delete,
1282                                TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ);
1283                 return 0;
1284         }
1285         return tomoyo_write_file_policy(data, domain, is_delete);
1286 }
1287
1288 /**
1289  * tomoyo_print_single_path_acl - Print a single path ACL entry.
1290  *
1291  * @head: Pointer to "struct tomoyo_io_buffer".
1292  * @ptr:  Pointer to "struct tomoyo_single_path_acl_record".
1293  *
1294  * Returns true on success, false otherwise.
1295  */
1296 static bool tomoyo_print_single_path_acl(struct tomoyo_io_buffer *head,
1297                                          struct tomoyo_single_path_acl_record *
1298                                          ptr)
1299 {
1300         int pos;
1301         u8 bit;
1302         const char *atmark = "";
1303         const char *filename;
1304         const u16 perm = ptr->perm;
1305
1306         filename = ptr->filename->name;
1307         for (bit = head->read_bit; bit < TOMOYO_MAX_SINGLE_PATH_OPERATION;
1308              bit++) {
1309                 const char *msg;
1310                 if (!(perm & (1 << bit)))
1311                         continue;
1312                 /* Print "read/write" instead of "read" and "write". */
1313                 if ((bit == TOMOYO_TYPE_READ_ACL ||
1314                      bit == TOMOYO_TYPE_WRITE_ACL)
1315                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL)))
1316                         continue;
1317                 msg = tomoyo_sp2keyword(bit);
1318                 pos = head->read_avail;
1319                 if (!tomoyo_io_printf(head, "allow_%s %s%s\n", msg,
1320                                       atmark, filename))
1321                         goto out;
1322         }
1323         head->read_bit = 0;
1324         return true;
1325  out:
1326         head->read_bit = bit;
1327         head->read_avail = pos;
1328         return false;
1329 }
1330
1331 /**
1332  * tomoyo_print_double_path_acl - Print a double path ACL entry.
1333  *
1334  * @head: Pointer to "struct tomoyo_io_buffer".
1335  * @ptr:  Pointer to "struct tomoyo_double_path_acl_record".
1336  *
1337  * Returns true on success, false otherwise.
1338  */
1339 static bool tomoyo_print_double_path_acl(struct tomoyo_io_buffer *head,
1340                                          struct tomoyo_double_path_acl_record *
1341                                          ptr)
1342 {
1343         int pos;
1344         const char *atmark1 = "";
1345         const char *atmark2 = "";
1346         const char *filename1;
1347         const char *filename2;
1348         const u8 perm = ptr->perm;
1349         u8 bit;
1350
1351         filename1 = ptr->filename1->name;
1352         filename2 = ptr->filename2->name;
1353         for (bit = head->read_bit; bit < TOMOYO_MAX_DOUBLE_PATH_OPERATION;
1354              bit++) {
1355                 const char *msg;
1356                 if (!(perm & (1 << bit)))
1357                         continue;
1358                 msg = tomoyo_dp2keyword(bit);
1359                 pos = head->read_avail;
1360                 if (!tomoyo_io_printf(head, "allow_%s %s%s %s%s\n", msg,
1361                                       atmark1, filename1, atmark2, filename2))
1362                         goto out;
1363         }
1364         head->read_bit = 0;
1365         return true;
1366  out:
1367         head->read_bit = bit;
1368         head->read_avail = pos;
1369         return false;
1370 }
1371
1372 /**
1373  * tomoyo_print_entry - Print an ACL entry.
1374  *
1375  * @head: Pointer to "struct tomoyo_io_buffer".
1376  * @ptr:  Pointer to an ACL entry.
1377  *
1378  * Returns true on success, false otherwise.
1379  */
1380 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1381                                struct tomoyo_acl_info *ptr)
1382 {
1383         const u8 acl_type = tomoyo_acl_type2(ptr);
1384
1385         if (acl_type & TOMOYO_ACL_DELETED)
1386                 return true;
1387         if (acl_type == TOMOYO_TYPE_SINGLE_PATH_ACL) {
1388                 struct tomoyo_single_path_acl_record *acl
1389                         = container_of(ptr,
1390                                        struct tomoyo_single_path_acl_record,
1391                                        head);
1392                 return tomoyo_print_single_path_acl(head, acl);
1393         }
1394         if (acl_type == TOMOYO_TYPE_DOUBLE_PATH_ACL) {
1395                 struct tomoyo_double_path_acl_record *acl
1396                         = container_of(ptr,
1397                                        struct tomoyo_double_path_acl_record,
1398                                        head);
1399                 return tomoyo_print_double_path_acl(head, acl);
1400         }
1401         BUG(); /* This must not happen. */
1402         return false;
1403 }
1404
1405 /**
1406  * tomoyo_read_domain_policy - Read domain policy.
1407  *
1408  * @head: Pointer to "struct tomoyo_io_buffer".
1409  *
1410  * Returns 0.
1411  */
1412 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1413 {
1414         struct list_head *dpos;
1415         struct list_head *apos;
1416         bool done = true;
1417
1418         if (head->read_eof)
1419                 return 0;
1420         if (head->read_step == 0)
1421                 head->read_step = 1;
1422         down_read(&tomoyo_domain_list_lock);
1423         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1424                 struct tomoyo_domain_info *domain;
1425                 const char *quota_exceeded = "";
1426                 const char *transition_failed = "";
1427                 const char *ignore_global_allow_read = "";
1428                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1429                 if (head->read_step != 1)
1430                         goto acl_loop;
1431                 if (domain->is_deleted && !head->read_single_domain)
1432                         continue;
1433                 /* Print domainname and flags. */
1434                 if (domain->quota_warned)
1435                         quota_exceeded = "quota_exceeded\n";
1436                 if (domain->flags & TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED)
1437                         transition_failed = "transition_failed\n";
1438                 if (domain->flags &
1439                     TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ)
1440                         ignore_global_allow_read
1441                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1442                 done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
1443                                         "%u\n%s%s%s\n",
1444                                         domain->domainname->name,
1445                                         domain->profile, quota_exceeded,
1446                                         transition_failed,
1447                                         ignore_global_allow_read);
1448                 if (!done)
1449                         break;
1450                 head->read_step = 2;
1451 acl_loop:
1452                 if (head->read_step == 3)
1453                         goto tail_mark;
1454                 /* Print ACL entries in the domain. */
1455                 down_read(&tomoyo_domain_acl_info_list_lock);
1456                 list_for_each_cookie(apos, head->read_var2,
1457                                      &domain->acl_info_list) {
1458                         struct tomoyo_acl_info *ptr
1459                                 = list_entry(apos, struct tomoyo_acl_info,
1460                                              list);
1461                         done = tomoyo_print_entry(head, ptr);
1462                         if (!done)
1463                                 break;
1464                 }
1465                 up_read(&tomoyo_domain_acl_info_list_lock);
1466                 if (!done)
1467                         break;
1468                 head->read_step = 3;
1469 tail_mark:
1470                 done = tomoyo_io_printf(head, "\n");
1471                 if (!done)
1472                         break;
1473                 head->read_step = 1;
1474                 if (head->read_single_domain)
1475                         break;
1476         }
1477         up_read(&tomoyo_domain_list_lock);
1478         head->read_eof = done;
1479         return 0;
1480 }
1481
1482 /**
1483  * tomoyo_write_domain_profile - Assign profile for specified domain.
1484  *
1485  * @head: Pointer to "struct tomoyo_io_buffer".
1486  *
1487  * Returns 0 on success, -EINVAL otherwise.
1488  *
1489  * This is equivalent to doing
1490  *
1491  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1492  *     /usr/lib/ccs/loadpolicy -d
1493  */
1494 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1495 {
1496         char *data = head->write_buf;
1497         char *cp = strchr(data, ' ');
1498         struct tomoyo_domain_info *domain;
1499         unsigned long profile;
1500
1501         if (!cp)
1502                 return -EINVAL;
1503         *cp = '\0';
1504         down_read(&tomoyo_domain_list_lock);
1505         domain = tomoyo_find_domain(cp + 1);
1506         up_read(&tomoyo_domain_list_lock);
1507         if (strict_strtoul(data, 10, &profile))
1508                 return -EINVAL;
1509         if (domain && profile < TOMOYO_MAX_PROFILES
1510             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1511                 domain->profile = (u8) profile;
1512         return 0;
1513 }
1514
1515 /**
1516  * tomoyo_read_domain_profile - Read only domainname and profile.
1517  *
1518  * @head: Pointer to "struct tomoyo_io_buffer".
1519  *
1520  * Returns list of profile number and domainname pairs.
1521  *
1522  * This is equivalent to doing
1523  *
1524  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1525  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1526  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1527  *     print $2 " " domainname; domainname = ""; } } ; '
1528  */
1529 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1530 {
1531         struct list_head *pos;
1532         bool done = true;
1533
1534         if (head->read_eof)
1535                 return 0;
1536         down_read(&tomoyo_domain_list_lock);
1537         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1538                 struct tomoyo_domain_info *domain;
1539                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1540                 if (domain->is_deleted)
1541                         continue;
1542                 done = tomoyo_io_printf(head, "%u %s\n", domain->profile,
1543                                         domain->domainname->name);
1544                 if (!done)
1545                         break;
1546         }
1547         up_read(&tomoyo_domain_list_lock);
1548         head->read_eof = done;
1549         return 0;
1550 }
1551
1552 /**
1553  * tomoyo_write_pid: Specify PID to obtain domainname.
1554  *
1555  * @head: Pointer to "struct tomoyo_io_buffer".
1556  *
1557  * Returns 0.
1558  */
1559 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1560 {
1561         unsigned long pid;
1562         /* No error check. */
1563         strict_strtoul(head->write_buf, 10, &pid);
1564         head->read_step = (int) pid;
1565         head->read_eof = false;
1566         return 0;
1567 }
1568
1569 /**
1570  * tomoyo_read_pid - Get domainname of the specified PID.
1571  *
1572  * @head: Pointer to "struct tomoyo_io_buffer".
1573  *
1574  * Returns the domainname which the specified PID is in on success,
1575  * empty string otherwise.
1576  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1577  * using read()/write() interface rather than sysctl() interface.
1578  */
1579 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1580 {
1581         if (head->read_avail == 0 && !head->read_eof) {
1582                 const int pid = head->read_step;
1583                 struct task_struct *p;
1584                 struct tomoyo_domain_info *domain = NULL;
1585                 read_lock(&tasklist_lock);
1586                 p = find_task_by_vpid(pid);
1587                 if (p)
1588                         domain = tomoyo_real_domain(p);
1589                 read_unlock(&tasklist_lock);
1590                 if (domain)
1591                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1592                                          domain->domainname->name);
1593                 head->read_eof = true;
1594         }
1595         return 0;
1596 }
1597
1598 /**
1599  * tomoyo_write_exception_policy - Write exception policy.
1600  *
1601  * @head: Pointer to "struct tomoyo_io_buffer".
1602  *
1603  * Returns 0 on success, negative value otherwise.
1604  */
1605 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1606 {
1607         char *data = head->write_buf;
1608         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1609
1610         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1611                 return tomoyo_write_domain_keeper_policy(data, false,
1612                                                          is_delete);
1613         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1614                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1615         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1616                 return tomoyo_write_domain_initializer_policy(data, false,
1617                                                               is_delete);
1618         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1619                 return tomoyo_write_domain_initializer_policy(data, true,
1620                                                               is_delete);
1621         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1622                 return tomoyo_write_alias_policy(data, is_delete);
1623         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1624                 return tomoyo_write_globally_readable_policy(data, is_delete);
1625         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1626                 return tomoyo_write_pattern_policy(data, is_delete);
1627         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1628                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1629         return -EINVAL;
1630 }
1631
1632 /**
1633  * tomoyo_read_exception_policy - Read exception policy.
1634  *
1635  * @head: Pointer to "struct tomoyo_io_buffer".
1636  *
1637  * Returns 0 on success, -EINVAL otherwise.
1638  */
1639 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1640 {
1641         if (!head->read_eof) {
1642                 switch (head->read_step) {
1643                 case 0:
1644                         head->read_var2 = NULL;
1645                         head->read_step = 1;
1646                 case 1:
1647                         if (!tomoyo_read_domain_keeper_policy(head))
1648                                 break;
1649                         head->read_var2 = NULL;
1650                         head->read_step = 2;
1651                 case 2:
1652                         if (!tomoyo_read_globally_readable_policy(head))
1653                                 break;
1654                         head->read_var2 = NULL;
1655                         head->read_step = 3;
1656                 case 3:
1657                         head->read_var2 = NULL;
1658                         head->read_step = 4;
1659                 case 4:
1660                         if (!tomoyo_read_domain_initializer_policy(head))
1661                                 break;
1662                         head->read_var2 = NULL;
1663                         head->read_step = 5;
1664                 case 5:
1665                         if (!tomoyo_read_alias_policy(head))
1666                                 break;
1667                         head->read_var2 = NULL;
1668                         head->read_step = 6;
1669                 case 6:
1670                         head->read_var2 = NULL;
1671                         head->read_step = 7;
1672                 case 7:
1673                         if (!tomoyo_read_file_pattern(head))
1674                                 break;
1675                         head->read_var2 = NULL;
1676                         head->read_step = 8;
1677                 case 8:
1678                         if (!tomoyo_read_no_rewrite_policy(head))
1679                                 break;
1680                         head->read_var2 = NULL;
1681                         head->read_step = 9;
1682                 case 9:
1683                         head->read_eof = true;
1684                         break;
1685                 default:
1686                         return -EINVAL;
1687                 }
1688         }
1689         return 0;
1690 }
1691
1692 /* path to policy loader */
1693 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1694
1695 /**
1696  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1697  *
1698  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1699  */
1700 static bool tomoyo_policy_loader_exists(void)
1701 {
1702         /*
1703          * Don't activate MAC if the policy loader doesn't exist.
1704          * If the initrd includes /sbin/init but real-root-dev has not
1705          * mounted on / yet, activating MAC will block the system since
1706          * policies are not loaded yet.
1707          * Thus, let do_execve() call this function everytime.
1708          */
1709         struct path path;
1710
1711         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
1712                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1713                        "since %s doesn't exist.\n", tomoyo_loader);
1714                 return false;
1715         }
1716         path_put(&path);
1717         return true;
1718 }
1719
1720 /**
1721  * tomoyo_load_policy - Run external policy loader to load policy.
1722  *
1723  * @filename: The program about to start.
1724  *
1725  * This function checks whether @filename is /sbin/init , and if so
1726  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1727  * and then continues invocation of /sbin/init.
1728  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1729  * writes to /sys/kernel/security/tomoyo/ interfaces.
1730  *
1731  * Returns nothing.
1732  */
1733 void tomoyo_load_policy(const char *filename)
1734 {
1735         char *argv[2];
1736         char *envp[3];
1737
1738         if (tomoyo_policy_loaded)
1739                 return;
1740         /*
1741          * Check filename is /sbin/init or /sbin/tomoyo-start.
1742          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1743          * be passed.
1744          * You can create /sbin/tomoyo-start by
1745          * "ln -s /bin/true /sbin/tomoyo-start".
1746          */
1747         if (strcmp(filename, "/sbin/init") &&
1748             strcmp(filename, "/sbin/tomoyo-start"))
1749                 return;
1750         if (!tomoyo_policy_loader_exists())
1751                 return;
1752
1753         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1754                tomoyo_loader);
1755         argv[0] = (char *) tomoyo_loader;
1756         argv[1] = NULL;
1757         envp[0] = "HOME=/";
1758         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1759         envp[2] = NULL;
1760         call_usermodehelper(argv[0], argv, envp, 1);
1761
1762         printk(KERN_INFO "TOMOYO: 2.2.0   2009/04/01\n");
1763         printk(KERN_INFO "Mandatory Access Control activated.\n");
1764         tomoyo_policy_loaded = true;
1765         { /* Check all profiles currently assigned to domains are defined. */
1766                 struct tomoyo_domain_info *domain;
1767                 down_read(&tomoyo_domain_list_lock);
1768                 list_for_each_entry(domain, &tomoyo_domain_list, list) {
1769                         const u8 profile = domain->profile;
1770                         if (tomoyo_profile_ptr[profile])
1771                                 continue;
1772                         panic("Profile %u (used by '%s') not defined.\n",
1773                               profile, domain->domainname->name);
1774                 }
1775                 up_read(&tomoyo_domain_list_lock);
1776         }
1777 }
1778
1779 /**
1780  * tomoyo_read_version: Get version.
1781  *
1782  * @head: Pointer to "struct tomoyo_io_buffer".
1783  *
1784  * Returns version information.
1785  */
1786 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1787 {
1788         if (!head->read_eof) {
1789                 tomoyo_io_printf(head, "2.2.0");
1790                 head->read_eof = true;
1791         }
1792         return 0;
1793 }
1794
1795 /**
1796  * tomoyo_read_self_domain - Get the current process's domainname.
1797  *
1798  * @head: Pointer to "struct tomoyo_io_buffer".
1799  *
1800  * Returns the current process's domainname.
1801  */
1802 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1803 {
1804         if (!head->read_eof) {
1805                 /*
1806                  * tomoyo_domain()->domainname != NULL
1807                  * because every process belongs to a domain and
1808                  * the domain's name cannot be NULL.
1809                  */
1810                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1811                 head->read_eof = true;
1812         }
1813         return 0;
1814 }
1815
1816 /**
1817  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1818  *
1819  * @type: Type of interface.
1820  * @file: Pointer to "struct file".
1821  *
1822  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1823  */
1824 static int tomoyo_open_control(const u8 type, struct file *file)
1825 {
1826         struct tomoyo_io_buffer *head = tomoyo_alloc(sizeof(*head));
1827
1828         if (!head)
1829                 return -ENOMEM;
1830         mutex_init(&head->io_sem);
1831         switch (type) {
1832         case TOMOYO_DOMAINPOLICY:
1833                 /* /sys/kernel/security/tomoyo/domain_policy */
1834                 head->write = tomoyo_write_domain_policy;
1835                 head->read = tomoyo_read_domain_policy;
1836                 break;
1837         case TOMOYO_EXCEPTIONPOLICY:
1838                 /* /sys/kernel/security/tomoyo/exception_policy */
1839                 head->write = tomoyo_write_exception_policy;
1840                 head->read = tomoyo_read_exception_policy;
1841                 break;
1842         case TOMOYO_SELFDOMAIN:
1843                 /* /sys/kernel/security/tomoyo/self_domain */
1844                 head->read = tomoyo_read_self_domain;
1845                 break;
1846         case TOMOYO_DOMAIN_STATUS:
1847                 /* /sys/kernel/security/tomoyo/.domain_status */
1848                 head->write = tomoyo_write_domain_profile;
1849                 head->read = tomoyo_read_domain_profile;
1850                 break;
1851         case TOMOYO_PROCESS_STATUS:
1852                 /* /sys/kernel/security/tomoyo/.process_status */
1853                 head->write = tomoyo_write_pid;
1854                 head->read = tomoyo_read_pid;
1855                 break;
1856         case TOMOYO_VERSION:
1857                 /* /sys/kernel/security/tomoyo/version */
1858                 head->read = tomoyo_read_version;
1859                 head->readbuf_size = 128;
1860                 break;
1861         case TOMOYO_MEMINFO:
1862                 /* /sys/kernel/security/tomoyo/meminfo */
1863                 head->write = tomoyo_write_memory_quota;
1864                 head->read = tomoyo_read_memory_counter;
1865                 head->readbuf_size = 512;
1866                 break;
1867         case TOMOYO_PROFILE:
1868                 /* /sys/kernel/security/tomoyo/profile */
1869                 head->write = tomoyo_write_profile;
1870                 head->read = tomoyo_read_profile;
1871                 break;
1872         case TOMOYO_MANAGER:
1873                 /* /sys/kernel/security/tomoyo/manager */
1874                 head->write = tomoyo_write_manager_policy;
1875                 head->read = tomoyo_read_manager_policy;
1876                 break;
1877         }
1878         if (!(file->f_mode & FMODE_READ)) {
1879                 /*
1880                  * No need to allocate read_buf since it is not opened
1881                  * for reading.
1882                  */
1883                 head->read = NULL;
1884         } else {
1885                 if (!head->readbuf_size)
1886                         head->readbuf_size = 4096 * 2;
1887                 head->read_buf = tomoyo_alloc(head->readbuf_size);
1888                 if (!head->read_buf) {
1889                         tomoyo_free(head);
1890                         return -ENOMEM;
1891                 }
1892         }
1893         if (!(file->f_mode & FMODE_WRITE)) {
1894                 /*
1895                  * No need to allocate write_buf since it is not opened
1896                  * for writing.
1897                  */
1898                 head->write = NULL;
1899         } else if (head->write) {
1900                 head->writebuf_size = 4096 * 2;
1901                 head->write_buf = tomoyo_alloc(head->writebuf_size);
1902                 if (!head->write_buf) {
1903                         tomoyo_free(head->read_buf);
1904                         tomoyo_free(head);
1905                         return -ENOMEM;
1906                 }
1907         }
1908         file->private_data = head;
1909         /*
1910          * Call the handler now if the file is
1911          * /sys/kernel/security/tomoyo/self_domain
1912          * so that the user can use
1913          * cat < /sys/kernel/security/tomoyo/self_domain"
1914          * to know the current process's domainname.
1915          */
1916         if (type == TOMOYO_SELFDOMAIN)
1917                 tomoyo_read_control(file, NULL, 0);
1918         return 0;
1919 }
1920
1921 /**
1922  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
1923  *
1924  * @file:       Pointer to "struct file".
1925  * @buffer:     Poiner to buffer to write to.
1926  * @buffer_len: Size of @buffer.
1927  *
1928  * Returns bytes read on success, negative value otherwise.
1929  */
1930 static int tomoyo_read_control(struct file *file, char __user *buffer,
1931                                const int buffer_len)
1932 {
1933         int len = 0;
1934         struct tomoyo_io_buffer *head = file->private_data;
1935         char *cp;
1936
1937         if (!head->read)
1938                 return -ENOSYS;
1939         if (mutex_lock_interruptible(&head->io_sem))
1940                 return -EINTR;
1941         /* Call the policy handler. */
1942         len = head->read(head);
1943         if (len < 0)
1944                 goto out;
1945         /* Write to buffer. */
1946         len = head->read_avail;
1947         if (len > buffer_len)
1948                 len = buffer_len;
1949         if (!len)
1950                 goto out;
1951         /* head->read_buf changes by some functions. */
1952         cp = head->read_buf;
1953         if (copy_to_user(buffer, cp, len)) {
1954                 len = -EFAULT;
1955                 goto out;
1956         }
1957         head->read_avail -= len;
1958         memmove(cp, cp + len, head->read_avail);
1959  out:
1960         mutex_unlock(&head->io_sem);
1961         return len;
1962 }
1963
1964 /**
1965  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
1966  *
1967  * @file:       Pointer to "struct file".
1968  * @buffer:     Pointer to buffer to read from.
1969  * @buffer_len: Size of @buffer.
1970  *
1971  * Returns @buffer_len on success, negative value otherwise.
1972  */
1973 static int tomoyo_write_control(struct file *file, const char __user *buffer,
1974                                 const int buffer_len)
1975 {
1976         struct tomoyo_io_buffer *head = file->private_data;
1977         int error = buffer_len;
1978         int avail_len = buffer_len;
1979         char *cp0 = head->write_buf;
1980
1981         if (!head->write)
1982                 return -ENOSYS;
1983         if (!access_ok(VERIFY_READ, buffer, buffer_len))
1984                 return -EFAULT;
1985         /* Don't allow updating policies by non manager programs. */
1986         if (head->write != tomoyo_write_pid &&
1987             head->write != tomoyo_write_domain_policy &&
1988             !tomoyo_is_policy_manager())
1989                 return -EPERM;
1990         if (mutex_lock_interruptible(&head->io_sem))
1991                 return -EINTR;
1992         /* Read a line and dispatch it to the policy handler. */
1993         while (avail_len > 0) {
1994                 char c;
1995                 if (head->write_avail >= head->writebuf_size - 1) {
1996                         error = -ENOMEM;
1997                         break;
1998                 } else if (get_user(c, buffer)) {
1999                         error = -EFAULT;
2000                         break;
2001                 }
2002                 buffer++;
2003                 avail_len--;
2004                 cp0[head->write_avail++] = c;
2005                 if (c != '\n')
2006                         continue;
2007                 cp0[head->write_avail - 1] = '\0';
2008                 head->write_avail = 0;
2009                 tomoyo_normalize_line(cp0);
2010                 head->write(head);
2011         }
2012         mutex_unlock(&head->io_sem);
2013         return error;
2014 }
2015
2016 /**
2017  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2018  *
2019  * @file: Pointer to "struct file".
2020  *
2021  * Releases memory and returns 0.
2022  */
2023 static int tomoyo_close_control(struct file *file)
2024 {
2025         struct tomoyo_io_buffer *head = file->private_data;
2026
2027         /* Release memory used for policy I/O. */
2028         tomoyo_free(head->read_buf);
2029         head->read_buf = NULL;
2030         tomoyo_free(head->write_buf);
2031         head->write_buf = NULL;
2032         tomoyo_free(head);
2033         head = NULL;
2034         file->private_data = NULL;
2035         return 0;
2036 }
2037
2038 /**
2039  * tomoyo_alloc_acl_element - Allocate permanent memory for ACL entry.
2040  *
2041  * @acl_type:  Type of ACL entry.
2042  *
2043  * Returns pointer to the ACL entry on success, NULL otherwise.
2044  */
2045 void *tomoyo_alloc_acl_element(const u8 acl_type)
2046 {
2047         int len;
2048         struct tomoyo_acl_info *ptr;
2049
2050         switch (acl_type) {
2051         case TOMOYO_TYPE_SINGLE_PATH_ACL:
2052                 len = sizeof(struct tomoyo_single_path_acl_record);
2053                 break;
2054         case TOMOYO_TYPE_DOUBLE_PATH_ACL:
2055                 len = sizeof(struct tomoyo_double_path_acl_record);
2056                 break;
2057         default:
2058                 return NULL;
2059         }
2060         ptr = tomoyo_alloc_element(len);
2061         if (!ptr)
2062                 return NULL;
2063         ptr->type = acl_type;
2064         return ptr;
2065 }
2066
2067 /**
2068  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2069  *
2070  * @inode: Pointer to "struct inode".
2071  * @file:  Pointer to "struct file".
2072  *
2073  * Returns 0 on success, negative value otherwise.
2074  */
2075 static int tomoyo_open(struct inode *inode, struct file *file)
2076 {
2077         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2078                 - ((u8 *) NULL);
2079         return tomoyo_open_control(key, file);
2080 }
2081
2082 /**
2083  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2084  *
2085  * @inode: Pointer to "struct inode".
2086  * @file:  Pointer to "struct file".
2087  *
2088  * Returns 0 on success, negative value otherwise.
2089  */
2090 static int tomoyo_release(struct inode *inode, struct file *file)
2091 {
2092         return tomoyo_close_control(file);
2093 }
2094
2095 /**
2096  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2097  *
2098  * @file:  Pointer to "struct file".
2099  * @buf:   Pointer to buffer.
2100  * @count: Size of @buf.
2101  * @ppos:  Unused.
2102  *
2103  * Returns bytes read on success, negative value otherwise.
2104  */
2105 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2106                            loff_t *ppos)
2107 {
2108         return tomoyo_read_control(file, buf, count);
2109 }
2110
2111 /**
2112  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2113  *
2114  * @file:  Pointer to "struct file".
2115  * @buf:   Pointer to buffer.
2116  * @count: Size of @buf.
2117  * @ppos:  Unused.
2118  *
2119  * Returns @count on success, negative value otherwise.
2120  */
2121 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2122                             size_t count, loff_t *ppos)
2123 {
2124         return tomoyo_write_control(file, buf, count);
2125 }
2126
2127 /* Operations for /sys/kernel/security/tomoyo/ interface. */
2128 static const struct file_operations tomoyo_operations = {
2129         .open    = tomoyo_open,
2130         .release = tomoyo_release,
2131         .read    = tomoyo_read,
2132         .write   = tomoyo_write,
2133 };
2134
2135 /**
2136  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2137  *
2138  * @name:   The name of the interface file.
2139  * @mode:   The permission of the interface file.
2140  * @parent: The parent directory.
2141  * @key:    Type of interface.
2142  *
2143  * Returns nothing.
2144  */
2145 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2146                                        struct dentry *parent, const u8 key)
2147 {
2148         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2149                                &tomoyo_operations);
2150 }
2151
2152 /**
2153  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2154  *
2155  * Returns 0.
2156  */
2157 static int __init tomoyo_initerface_init(void)
2158 {
2159         struct dentry *tomoyo_dir;
2160
2161         /* Don't create securityfs entries unless registered. */
2162         if (current_cred()->security != &tomoyo_kernel_domain)
2163                 return 0;
2164
2165         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2166         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2167                             TOMOYO_DOMAINPOLICY);
2168         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2169                             TOMOYO_EXCEPTIONPOLICY);
2170         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2171                             TOMOYO_SELFDOMAIN);
2172         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2173                             TOMOYO_DOMAIN_STATUS);
2174         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2175                             TOMOYO_PROCESS_STATUS);
2176         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2177                             TOMOYO_MEMINFO);
2178         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2179                             TOMOYO_PROFILE);
2180         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2181                             TOMOYO_MANAGER);
2182         tomoyo_create_entry("version",          0400, tomoyo_dir,
2183                             TOMOYO_VERSION);
2184         return 0;
2185 }
2186
2187 fs_initcall(tomoyo_initerface_init);