92cea656ad2162e07fef90ef71fb08d3cfe01878
[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-pre   2009/02/01
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         /***** EXCLUSIVE SECTION START *****/
870         mutex_lock(&lock);
871         ptr = tomoyo_profile_ptr[profile];
872         if (ptr)
873                 goto ok;
874         ptr = tomoyo_alloc_element(sizeof(*ptr));
875         if (!ptr)
876                 goto ok;
877         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
878                 ptr->value[i] = tomoyo_control_array[i].current_value;
879         mb(); /* Avoid out-of-order execution. */
880         tomoyo_profile_ptr[profile] = ptr;
881  ok:
882         mutex_unlock(&lock);
883         /***** EXCLUSIVE SECTION END *****/
884         return ptr;
885 }
886
887 /**
888  * tomoyo_write_profile - Write to profile table.
889  *
890  * @head: Pointer to "struct tomoyo_io_buffer".
891  *
892  * Returns 0 on success, negative value otherwise.
893  */
894 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
895 {
896         char *data = head->write_buf;
897         unsigned int i;
898         unsigned int value;
899         char *cp;
900         struct tomoyo_profile *profile;
901         unsigned long num;
902
903         cp = strchr(data, '-');
904         if (cp)
905                 *cp = '\0';
906         if (strict_strtoul(data, 10, &num))
907                 return -EINVAL;
908         if (cp)
909                 data = cp + 1;
910         profile = tomoyo_find_or_assign_new_profile(num);
911         if (!profile)
912                 return -EINVAL;
913         cp = strchr(data, '=');
914         if (!cp)
915                 return -EINVAL;
916         *cp = '\0';
917         if (!strcmp(data, "COMMENT")) {
918                 profile->comment = tomoyo_save_name(cp + 1);
919                 return 0;
920         }
921         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
922                 if (strcmp(data, tomoyo_control_array[i].keyword))
923                         continue;
924                 if (sscanf(cp + 1, "%u", &value) != 1) {
925                         int j;
926                         const char **modes;
927                         switch (i) {
928                         case TOMOYO_VERBOSE:
929                                 modes = tomoyo_mode_2;
930                                 break;
931                         default:
932                                 modes = tomoyo_mode_4;
933                                 break;
934                         }
935                         for (j = 0; j < 4; j++) {
936                                 if (strcmp(cp + 1, modes[j]))
937                                         continue;
938                                 value = j;
939                                 break;
940                         }
941                         if (j == 4)
942                                 return -EINVAL;
943                 } else if (value > tomoyo_control_array[i].max_value) {
944                         value = tomoyo_control_array[i].max_value;
945                 }
946                 profile->value[i] = value;
947                 return 0;
948         }
949         return -EINVAL;
950 }
951
952 /**
953  * tomoyo_read_profile - Read from profile table.
954  *
955  * @head: Pointer to "struct tomoyo_io_buffer".
956  *
957  * Returns 0.
958  */
959 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
960 {
961         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
962         int step;
963
964         if (head->read_eof)
965                 return 0;
966         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
967              step++) {
968                 const u8 index = step / total;
969                 u8 type = step % total;
970                 const struct tomoyo_profile *profile
971                         = tomoyo_profile_ptr[index];
972                 head->read_step = step;
973                 if (!profile)
974                         continue;
975                 if (!type) { /* Print profile' comment tag. */
976                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
977                                               index, profile->comment ?
978                                               profile->comment->name : ""))
979                                 break;
980                         continue;
981                 }
982                 type--;
983                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
984                         const unsigned int value = profile->value[type];
985                         const char **modes = NULL;
986                         const char *keyword
987                                 = tomoyo_control_array[type].keyword;
988                         switch (tomoyo_control_array[type].max_value) {
989                         case 3:
990                                 modes = tomoyo_mode_4;
991                                 break;
992                         case 1:
993                                 modes = tomoyo_mode_2;
994                                 break;
995                         }
996                         if (modes) {
997                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
998                                                       keyword, modes[value]))
999                                         break;
1000                         } else {
1001                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1002                                                       keyword, value))
1003                                         break;
1004                         }
1005                 }
1006         }
1007         if (step == TOMOYO_MAX_PROFILES * total)
1008                 head->read_eof = true;
1009         return 0;
1010 }
1011
1012 /* Structure for policy manager. */
1013 struct tomoyo_policy_manager_entry {
1014         struct list_head list;
1015         /* A path to program or a domainname. */
1016         const struct tomoyo_path_info *manager;
1017         bool is_domain;  /* True if manager is a domainname. */
1018         bool is_deleted; /* True if this entry is deleted. */
1019 };
1020
1021 /* The list for "struct tomoyo_policy_manager_entry". */
1022 static LIST_HEAD(tomoyo_policy_manager_list);
1023 static DECLARE_RWSEM(tomoyo_policy_manager_list_lock);
1024
1025 /**
1026  * tomoyo_update_manager_entry - Add a manager entry.
1027  *
1028  * @manager:   The path to manager or the domainnamme.
1029  * @is_delete: True if it is a delete request.
1030  *
1031  * Returns 0 on success, negative value otherwise.
1032  */
1033 static int tomoyo_update_manager_entry(const char *manager,
1034                                        const bool is_delete)
1035 {
1036         struct tomoyo_policy_manager_entry *new_entry;
1037         struct tomoyo_policy_manager_entry *ptr;
1038         const struct tomoyo_path_info *saved_manager;
1039         int error = -ENOMEM;
1040         bool is_domain = false;
1041
1042         if (tomoyo_is_domain_def(manager)) {
1043                 if (!tomoyo_is_correct_domain(manager, __func__))
1044                         return -EINVAL;
1045                 is_domain = true;
1046         } else {
1047                 if (!tomoyo_is_correct_path(manager, 1, -1, -1, __func__))
1048                         return -EINVAL;
1049         }
1050         saved_manager = tomoyo_save_name(manager);
1051         if (!saved_manager)
1052                 return -ENOMEM;
1053         /***** EXCLUSIVE SECTION START *****/
1054         down_write(&tomoyo_policy_manager_list_lock);
1055         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1056                 if (ptr->manager != saved_manager)
1057                         continue;
1058                 ptr->is_deleted = is_delete;
1059                 error = 0;
1060                 goto out;
1061         }
1062         if (is_delete) {
1063                 error = -ENOENT;
1064                 goto out;
1065         }
1066         new_entry = tomoyo_alloc_element(sizeof(*new_entry));
1067         if (!new_entry)
1068                 goto out;
1069         new_entry->manager = saved_manager;
1070         new_entry->is_domain = is_domain;
1071         list_add_tail(&new_entry->list, &tomoyo_policy_manager_list);
1072         error = 0;
1073  out:
1074         up_write(&tomoyo_policy_manager_list_lock);
1075         /***** EXCLUSIVE SECTION END *****/
1076         return error;
1077 }
1078
1079 /**
1080  * tomoyo_write_manager_policy - Write manager policy.
1081  *
1082  * @head: Pointer to "struct tomoyo_io_buffer".
1083  *
1084  * Returns 0 on success, negative value otherwise.
1085  */
1086 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1087 {
1088         char *data = head->write_buf;
1089         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1090
1091         if (!strcmp(data, "manage_by_non_root")) {
1092                 tomoyo_manage_by_non_root = !is_delete;
1093                 return 0;
1094         }
1095         return tomoyo_update_manager_entry(data, is_delete);
1096 }
1097
1098 /**
1099  * tomoyo_read_manager_policy - Read manager policy.
1100  *
1101  * @head: Pointer to "struct tomoyo_io_buffer".
1102  *
1103  * Returns 0.
1104  */
1105 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1106 {
1107         struct list_head *pos;
1108         bool done = true;
1109
1110         if (head->read_eof)
1111                 return 0;
1112         down_read(&tomoyo_policy_manager_list_lock);
1113         list_for_each_cookie(pos, head->read_var2,
1114                              &tomoyo_policy_manager_list) {
1115                 struct tomoyo_policy_manager_entry *ptr;
1116                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1117                                  list);
1118                 if (ptr->is_deleted)
1119                         continue;
1120                 if (!tomoyo_io_printf(head, "%s\n", ptr->manager->name)) {
1121                         done = false;
1122                         break;
1123                 }
1124         }
1125         up_read(&tomoyo_policy_manager_list_lock);
1126         head->read_eof = done;
1127         return 0;
1128 }
1129
1130 /**
1131  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1132  *
1133  * Returns true if the current process is permitted to modify policy
1134  * via /sys/kernel/security/tomoyo/ interface.
1135  */
1136 static bool tomoyo_is_policy_manager(void)
1137 {
1138         struct tomoyo_policy_manager_entry *ptr;
1139         const char *exe;
1140         const struct task_struct *task = current;
1141         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1142         bool found = false;
1143
1144         if (!tomoyo_policy_loaded)
1145                 return true;
1146         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1147                 return false;
1148         down_read(&tomoyo_policy_manager_list_lock);
1149         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1150                 if (!ptr->is_deleted && ptr->is_domain
1151                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1152                         found = true;
1153                         break;
1154                 }
1155         }
1156         up_read(&tomoyo_policy_manager_list_lock);
1157         if (found)
1158                 return true;
1159         exe = tomoyo_get_exe();
1160         if (!exe)
1161                 return false;
1162         down_read(&tomoyo_policy_manager_list_lock);
1163         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1164                 if (!ptr->is_deleted && !ptr->is_domain
1165                     && !strcmp(exe, ptr->manager->name)) {
1166                         found = true;
1167                         break;
1168                 }
1169         }
1170         up_read(&tomoyo_policy_manager_list_lock);
1171         if (!found) { /* Reduce error messages. */
1172                 static pid_t last_pid;
1173                 const pid_t pid = current->pid;
1174                 if (last_pid != pid) {
1175                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1176                                "update policies.\n", domainname->name, exe);
1177                         last_pid = pid;
1178                 }
1179         }
1180         tomoyo_free(exe);
1181         return found;
1182 }
1183
1184 /**
1185  * tomoyo_is_select_one - Parse select command.
1186  *
1187  * @head: Pointer to "struct tomoyo_io_buffer".
1188  * @data: String to parse.
1189  *
1190  * Returns true on success, false otherwise.
1191  */
1192 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1193                                  const char *data)
1194 {
1195         unsigned int pid;
1196         struct tomoyo_domain_info *domain = NULL;
1197
1198         if (sscanf(data, "pid=%u", &pid) == 1) {
1199                 struct task_struct *p;
1200                 /***** CRITICAL SECTION START *****/
1201                 read_lock(&tasklist_lock);
1202                 p = find_task_by_vpid(pid);
1203                 if (p)
1204                         domain = tomoyo_real_domain(p);
1205                 read_unlock(&tasklist_lock);
1206                 /***** CRITICAL SECTION END *****/
1207         } else if (!strncmp(data, "domain=", 7)) {
1208                 if (tomoyo_is_domain_def(data + 7)) {
1209                         down_read(&tomoyo_domain_list_lock);
1210                         domain = tomoyo_find_domain(data + 7);
1211                         up_read(&tomoyo_domain_list_lock);
1212                 }
1213         } else
1214                 return false;
1215         head->write_var1 = domain;
1216         /* Accessing read_buf is safe because head->io_sem is held. */
1217         if (!head->read_buf)
1218                 return true; /* Do nothing if open(O_WRONLY). */
1219         head->read_avail = 0;
1220         tomoyo_io_printf(head, "# select %s\n", data);
1221         head->read_single_domain = true;
1222         head->read_eof = !domain;
1223         if (domain) {
1224                 struct tomoyo_domain_info *d;
1225                 head->read_var1 = NULL;
1226                 down_read(&tomoyo_domain_list_lock);
1227                 list_for_each_entry(d, &tomoyo_domain_list, list) {
1228                         if (d == domain)
1229                                 break;
1230                         head->read_var1 = &d->list;
1231                 }
1232                 up_read(&tomoyo_domain_list_lock);
1233                 head->read_var2 = NULL;
1234                 head->read_bit = 0;
1235                 head->read_step = 0;
1236                 if (domain->is_deleted)
1237                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1238         }
1239         return true;
1240 }
1241
1242 /**
1243  * tomoyo_write_domain_policy - Write domain policy.
1244  *
1245  * @head: Pointer to "struct tomoyo_io_buffer".
1246  *
1247  * Returns 0 on success, negative value otherwise.
1248  */
1249 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1250 {
1251         char *data = head->write_buf;
1252         struct tomoyo_domain_info *domain = head->write_var1;
1253         bool is_delete = false;
1254         bool is_select = false;
1255         bool is_undelete = false;
1256         unsigned int profile;
1257
1258         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1259                 is_delete = true;
1260         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1261                 is_select = true;
1262         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_UNDELETE))
1263                 is_undelete = true;
1264         if (is_select && tomoyo_is_select_one(head, data))
1265                 return 0;
1266         /* Don't allow updating policies by non manager programs. */
1267         if (!tomoyo_is_policy_manager())
1268                 return -EPERM;
1269         if (tomoyo_is_domain_def(data)) {
1270                 domain = NULL;
1271                 if (is_delete)
1272                         tomoyo_delete_domain(data);
1273                 else if (is_select) {
1274                         down_read(&tomoyo_domain_list_lock);
1275                         domain = tomoyo_find_domain(data);
1276                         up_read(&tomoyo_domain_list_lock);
1277                 } else if (is_undelete)
1278                         domain = tomoyo_undelete_domain(data);
1279                 else
1280                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1281                 head->write_var1 = domain;
1282                 return 0;
1283         }
1284         if (!domain)
1285                 return -EINVAL;
1286
1287         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1288             && profile < TOMOYO_MAX_PROFILES) {
1289                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1290                         domain->profile = (u8) profile;
1291                 return 0;
1292         }
1293         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1294                 tomoyo_set_domain_flag(domain, is_delete,
1295                                TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ);
1296                 return 0;
1297         }
1298         return tomoyo_write_file_policy(data, domain, is_delete);
1299 }
1300
1301 /**
1302  * tomoyo_print_single_path_acl - Print a single path ACL entry.
1303  *
1304  * @head: Pointer to "struct tomoyo_io_buffer".
1305  * @ptr:  Pointer to "struct tomoyo_single_path_acl_record".
1306  *
1307  * Returns true on success, false otherwise.
1308  */
1309 static bool tomoyo_print_single_path_acl(struct tomoyo_io_buffer *head,
1310                                          struct tomoyo_single_path_acl_record *
1311                                          ptr)
1312 {
1313         int pos;
1314         u8 bit;
1315         const char *atmark = "";
1316         const char *filename;
1317         const u16 perm = ptr->perm;
1318
1319         filename = ptr->filename->name;
1320         for (bit = head->read_bit; bit < TOMOYO_MAX_SINGLE_PATH_OPERATION;
1321              bit++) {
1322                 const char *msg;
1323                 if (!(perm & (1 << bit)))
1324                         continue;
1325                 /* Print "read/write" instead of "read" and "write". */
1326                 if ((bit == TOMOYO_TYPE_READ_ACL ||
1327                      bit == TOMOYO_TYPE_WRITE_ACL)
1328                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL)))
1329                         continue;
1330                 msg = tomoyo_sp2keyword(bit);
1331                 pos = head->read_avail;
1332                 if (!tomoyo_io_printf(head, "allow_%s %s%s\n", msg,
1333                                       atmark, filename))
1334                         goto out;
1335         }
1336         head->read_bit = 0;
1337         return true;
1338  out:
1339         head->read_bit = bit;
1340         head->read_avail = pos;
1341         return false;
1342 }
1343
1344 /**
1345  * tomoyo_print_double_path_acl - Print a double path ACL entry.
1346  *
1347  * @head: Pointer to "struct tomoyo_io_buffer".
1348  * @ptr:  Pointer to "struct tomoyo_double_path_acl_record".
1349  *
1350  * Returns true on success, false otherwise.
1351  */
1352 static bool tomoyo_print_double_path_acl(struct tomoyo_io_buffer *head,
1353                                          struct tomoyo_double_path_acl_record *
1354                                          ptr)
1355 {
1356         int pos;
1357         const char *atmark1 = "";
1358         const char *atmark2 = "";
1359         const char *filename1;
1360         const char *filename2;
1361         const u8 perm = ptr->perm;
1362         u8 bit;
1363
1364         filename1 = ptr->filename1->name;
1365         filename2 = ptr->filename2->name;
1366         for (bit = head->read_bit; bit < TOMOYO_MAX_DOUBLE_PATH_OPERATION;
1367              bit++) {
1368                 const char *msg;
1369                 if (!(perm & (1 << bit)))
1370                         continue;
1371                 msg = tomoyo_dp2keyword(bit);
1372                 pos = head->read_avail;
1373                 if (!tomoyo_io_printf(head, "allow_%s %s%s %s%s\n", msg,
1374                                       atmark1, filename1, atmark2, filename2))
1375                         goto out;
1376         }
1377         head->read_bit = 0;
1378         return true;
1379  out:
1380         head->read_bit = bit;
1381         head->read_avail = pos;
1382         return false;
1383 }
1384
1385 /**
1386  * tomoyo_print_entry - Print an ACL entry.
1387  *
1388  * @head: Pointer to "struct tomoyo_io_buffer".
1389  * @ptr:  Pointer to an ACL entry.
1390  *
1391  * Returns true on success, false otherwise.
1392  */
1393 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1394                                struct tomoyo_acl_info *ptr)
1395 {
1396         const u8 acl_type = tomoyo_acl_type2(ptr);
1397
1398         if (acl_type & TOMOYO_ACL_DELETED)
1399                 return true;
1400         if (acl_type == TOMOYO_TYPE_SINGLE_PATH_ACL) {
1401                 struct tomoyo_single_path_acl_record *acl
1402                         = container_of(ptr,
1403                                        struct tomoyo_single_path_acl_record,
1404                                        head);
1405                 return tomoyo_print_single_path_acl(head, acl);
1406         }
1407         if (acl_type == TOMOYO_TYPE_DOUBLE_PATH_ACL) {
1408                 struct tomoyo_double_path_acl_record *acl
1409                         = container_of(ptr,
1410                                        struct tomoyo_double_path_acl_record,
1411                                        head);
1412                 return tomoyo_print_double_path_acl(head, acl);
1413         }
1414         BUG(); /* This must not happen. */
1415         return false;
1416 }
1417
1418 /**
1419  * tomoyo_read_domain_policy - Read domain policy.
1420  *
1421  * @head: Pointer to "struct tomoyo_io_buffer".
1422  *
1423  * Returns 0.
1424  */
1425 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1426 {
1427         struct list_head *dpos;
1428         struct list_head *apos;
1429         bool done = true;
1430
1431         if (head->read_eof)
1432                 return 0;
1433         if (head->read_step == 0)
1434                 head->read_step = 1;
1435         down_read(&tomoyo_domain_list_lock);
1436         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1437                 struct tomoyo_domain_info *domain;
1438                 const char *quota_exceeded = "";
1439                 const char *transition_failed = "";
1440                 const char *ignore_global_allow_read = "";
1441                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1442                 if (head->read_step != 1)
1443                         goto acl_loop;
1444                 if (domain->is_deleted && !head->read_single_domain)
1445                         continue;
1446                 /* Print domainname and flags. */
1447                 if (domain->quota_warned)
1448                         quota_exceeded = "quota_exceeded\n";
1449                 if (domain->flags & TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED)
1450                         transition_failed = "transition_failed\n";
1451                 if (domain->flags &
1452                     TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ)
1453                         ignore_global_allow_read
1454                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1455                 if (!tomoyo_io_printf(head,
1456                                       "%s\n" TOMOYO_KEYWORD_USE_PROFILE "%u\n"
1457                                       "%s%s%s\n", domain->domainname->name,
1458                                       domain->profile, quota_exceeded,
1459                                       transition_failed,
1460                                       ignore_global_allow_read)) {
1461                         done = false;
1462                         break;
1463                 }
1464                 head->read_step = 2;
1465 acl_loop:
1466                 if (head->read_step == 3)
1467                         goto tail_mark;
1468                 /* Print ACL entries in the domain. */
1469                 down_read(&tomoyo_domain_acl_info_list_lock);
1470                 list_for_each_cookie(apos, head->read_var2,
1471                                       &domain->acl_info_list) {
1472                         struct tomoyo_acl_info *ptr
1473                                 = list_entry(apos, struct tomoyo_acl_info,
1474                                               list);
1475                         if (!tomoyo_print_entry(head, ptr)) {
1476                                 done = false;
1477                                 break;
1478                         }
1479                 }
1480                 up_read(&tomoyo_domain_acl_info_list_lock);
1481                 if (!done)
1482                         break;
1483                 head->read_step = 3;
1484 tail_mark:
1485                 if (!tomoyo_io_printf(head, "\n")) {
1486                         done = false;
1487                         break;
1488                 }
1489                 head->read_step = 1;
1490                 if (head->read_single_domain)
1491                         break;
1492         }
1493         up_read(&tomoyo_domain_list_lock);
1494         head->read_eof = done;
1495         return 0;
1496 }
1497
1498 /**
1499  * tomoyo_write_domain_profile - Assign profile for specified domain.
1500  *
1501  * @head: Pointer to "struct tomoyo_io_buffer".
1502  *
1503  * Returns 0 on success, -EINVAL otherwise.
1504  *
1505  * This is equivalent to doing
1506  *
1507  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1508  *     /usr/lib/ccs/loadpolicy -d
1509  */
1510 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1511 {
1512         char *data = head->write_buf;
1513         char *cp = strchr(data, ' ');
1514         struct tomoyo_domain_info *domain;
1515         unsigned long profile;
1516
1517         if (!cp)
1518                 return -EINVAL;
1519         *cp = '\0';
1520         down_read(&tomoyo_domain_list_lock);
1521         domain = tomoyo_find_domain(cp + 1);
1522         up_read(&tomoyo_domain_list_lock);
1523         if (strict_strtoul(data, 10, &profile))
1524                 return -EINVAL;
1525         if (domain && profile < TOMOYO_MAX_PROFILES
1526             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1527                 domain->profile = (u8) profile;
1528         return 0;
1529 }
1530
1531 /**
1532  * tomoyo_read_domain_profile - Read only domainname and profile.
1533  *
1534  * @head: Pointer to "struct tomoyo_io_buffer".
1535  *
1536  * Returns list of profile number and domainname pairs.
1537  *
1538  * This is equivalent to doing
1539  *
1540  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1541  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1542  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1543  *     print $2 " " domainname; domainname = ""; } } ; '
1544  */
1545 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1546 {
1547         struct list_head *pos;
1548         bool done = true;
1549
1550         if (head->read_eof)
1551                 return 0;
1552         down_read(&tomoyo_domain_list_lock);
1553         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1554                 struct tomoyo_domain_info *domain;
1555                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1556                 if (domain->is_deleted)
1557                         continue;
1558                 if (!tomoyo_io_printf(head, "%u %s\n", domain->profile,
1559                                       domain->domainname->name)) {
1560                         done = false;
1561                         break;
1562                 }
1563         }
1564         up_read(&tomoyo_domain_list_lock);
1565         head->read_eof = done;
1566         return 0;
1567 }
1568
1569 /**
1570  * tomoyo_write_pid: Specify PID to obtain domainname.
1571  *
1572  * @head: Pointer to "struct tomoyo_io_buffer".
1573  *
1574  * Returns 0.
1575  */
1576 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1577 {
1578         unsigned long pid;
1579         /* No error check. */
1580         strict_strtoul(head->write_buf, 10, &pid);
1581         head->read_step = (int) pid;
1582         head->read_eof = false;
1583         return 0;
1584 }
1585
1586 /**
1587  * tomoyo_read_pid - Get domainname of the specified PID.
1588  *
1589  * @head: Pointer to "struct tomoyo_io_buffer".
1590  *
1591  * Returns the domainname which the specified PID is in on success,
1592  * empty string otherwise.
1593  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1594  * using read()/write() interface rather than sysctl() interface.
1595  */
1596 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1597 {
1598         if (head->read_avail == 0 && !head->read_eof) {
1599                 const int pid = head->read_step;
1600                 struct task_struct *p;
1601                 struct tomoyo_domain_info *domain = NULL;
1602                 /***** CRITICAL SECTION START *****/
1603                 read_lock(&tasklist_lock);
1604                 p = find_task_by_vpid(pid);
1605                 if (p)
1606                         domain = tomoyo_real_domain(p);
1607                 read_unlock(&tasklist_lock);
1608                 /***** CRITICAL SECTION END *****/
1609                 if (domain)
1610                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1611                                          domain->domainname->name);
1612                 head->read_eof = true;
1613         }
1614         return 0;
1615 }
1616
1617 /**
1618  * tomoyo_write_exception_policy - Write exception policy.
1619  *
1620  * @head: Pointer to "struct tomoyo_io_buffer".
1621  *
1622  * Returns 0 on success, negative value otherwise.
1623  */
1624 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1625 {
1626         char *data = head->write_buf;
1627         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1628
1629         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1630                 return tomoyo_write_domain_keeper_policy(data, false,
1631                                                          is_delete);
1632         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1633                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1634         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1635                 return tomoyo_write_domain_initializer_policy(data, false,
1636                                                               is_delete);
1637         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1638                 return tomoyo_write_domain_initializer_policy(data, true,
1639                                                               is_delete);
1640         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1641                 return tomoyo_write_alias_policy(data, is_delete);
1642         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1643                 return tomoyo_write_globally_readable_policy(data, is_delete);
1644         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1645                 return tomoyo_write_pattern_policy(data, is_delete);
1646         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1647                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1648         return -EINVAL;
1649 }
1650
1651 /**
1652  * tomoyo_read_exception_policy - Read exception policy.
1653  *
1654  * @head: Pointer to "struct tomoyo_io_buffer".
1655  *
1656  * Returns 0 on success, -EINVAL otherwise.
1657  */
1658 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1659 {
1660         if (!head->read_eof) {
1661                 switch (head->read_step) {
1662                 case 0:
1663                         head->read_var2 = NULL;
1664                         head->read_step = 1;
1665                 case 1:
1666                         if (!tomoyo_read_domain_keeper_policy(head))
1667                                 break;
1668                         head->read_var2 = NULL;
1669                         head->read_step = 2;
1670                 case 2:
1671                         if (!tomoyo_read_globally_readable_policy(head))
1672                                 break;
1673                         head->read_var2 = NULL;
1674                         head->read_step = 3;
1675                 case 3:
1676                         head->read_var2 = NULL;
1677                         head->read_step = 4;
1678                 case 4:
1679                         if (!tomoyo_read_domain_initializer_policy(head))
1680                                 break;
1681                         head->read_var2 = NULL;
1682                         head->read_step = 5;
1683                 case 5:
1684                         if (!tomoyo_read_alias_policy(head))
1685                                 break;
1686                         head->read_var2 = NULL;
1687                         head->read_step = 6;
1688                 case 6:
1689                         head->read_var2 = NULL;
1690                         head->read_step = 7;
1691                 case 7:
1692                         if (!tomoyo_read_file_pattern(head))
1693                                 break;
1694                         head->read_var2 = NULL;
1695                         head->read_step = 8;
1696                 case 8:
1697                         if (!tomoyo_read_no_rewrite_policy(head))
1698                                 break;
1699                         head->read_var2 = NULL;
1700                         head->read_step = 9;
1701                 case 9:
1702                         head->read_eof = true;
1703                         break;
1704                 default:
1705                         return -EINVAL;
1706                 }
1707         }
1708         return 0;
1709 }
1710
1711 /* path to policy loader */
1712 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1713
1714 /**
1715  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1716  *
1717  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1718  */
1719 static bool tomoyo_policy_loader_exists(void)
1720 {
1721         /*
1722          * Don't activate MAC if the policy loader doesn't exist.
1723          * If the initrd includes /sbin/init but real-root-dev has not
1724          * mounted on / yet, activating MAC will block the system since
1725          * policies are not loaded yet.
1726          * Thus, let do_execve() call this function everytime.
1727          */
1728         struct nameidata nd;
1729
1730         if (path_lookup(tomoyo_loader, LOOKUP_FOLLOW, &nd)) {
1731                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1732                        "since %s doesn't exist.\n", tomoyo_loader);
1733                 return false;
1734         }
1735         path_put(&nd.path);
1736         return true;
1737 }
1738
1739 /**
1740  * tomoyo_load_policy - Run external policy loader to load policy.
1741  *
1742  * @filename: The program about to start.
1743  *
1744  * This function checks whether @filename is /sbin/init , and if so
1745  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1746  * and then continues invocation of /sbin/init.
1747  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1748  * writes to /sys/kernel/security/tomoyo/ interfaces.
1749  *
1750  * Returns nothing.
1751  */
1752 void tomoyo_load_policy(const char *filename)
1753 {
1754         char *argv[2];
1755         char *envp[3];
1756
1757         if (tomoyo_policy_loaded)
1758                 return;
1759         /*
1760          * Check filename is /sbin/init or /sbin/tomoyo-start.
1761          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1762          * be passed.
1763          * You can create /sbin/tomoyo-start by
1764          * "ln -s /bin/true /sbin/tomoyo-start".
1765          */
1766         if (strcmp(filename, "/sbin/init") &&
1767             strcmp(filename, "/sbin/tomoyo-start"))
1768                 return;
1769         if (!tomoyo_policy_loader_exists())
1770                 return;
1771
1772         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1773                tomoyo_loader);
1774         argv[0] = (char *) tomoyo_loader;
1775         argv[1] = NULL;
1776         envp[0] = "HOME=/";
1777         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1778         envp[2] = NULL;
1779         call_usermodehelper(argv[0], argv, envp, 1);
1780
1781         printk(KERN_INFO "TOMOYO: 2.2.0-pre   2009/02/01\n");
1782         printk(KERN_INFO "Mandatory Access Control activated.\n");
1783         tomoyo_policy_loaded = true;
1784         { /* Check all profiles currently assigned to domains are defined. */
1785                 struct tomoyo_domain_info *domain;
1786                 down_read(&tomoyo_domain_list_lock);
1787                 list_for_each_entry(domain, &tomoyo_domain_list, list) {
1788                         const u8 profile = domain->profile;
1789                         if (tomoyo_profile_ptr[profile])
1790                                 continue;
1791                         panic("Profile %u (used by '%s') not defined.\n",
1792                               profile, domain->domainname->name);
1793                 }
1794                 up_read(&tomoyo_domain_list_lock);
1795         }
1796 }
1797
1798 /**
1799  * tomoyo_read_version: Get version.
1800  *
1801  * @head: Pointer to "struct tomoyo_io_buffer".
1802  *
1803  * Returns version information.
1804  */
1805 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1806 {
1807         if (!head->read_eof) {
1808                 tomoyo_io_printf(head, "2.2.0-pre");
1809                 head->read_eof = true;
1810         }
1811         return 0;
1812 }
1813
1814 /**
1815  * tomoyo_read_self_domain - Get the current process's domainname.
1816  *
1817  * @head: Pointer to "struct tomoyo_io_buffer".
1818  *
1819  * Returns the current process's domainname.
1820  */
1821 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1822 {
1823         if (!head->read_eof) {
1824                 /*
1825                  * tomoyo_domain()->domainname != NULL
1826                  * because every process belongs to a domain and
1827                  * the domain's name cannot be NULL.
1828                  */
1829                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1830                 head->read_eof = true;
1831         }
1832         return 0;
1833 }
1834
1835 /**
1836  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1837  *
1838  * @type: Type of interface.
1839  * @file: Pointer to "struct file".
1840  *
1841  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1842  */
1843 static int tomoyo_open_control(const u8 type, struct file *file)
1844 {
1845         struct tomoyo_io_buffer *head = tomoyo_alloc(sizeof(*head));
1846
1847         if (!head)
1848                 return -ENOMEM;
1849         mutex_init(&head->io_sem);
1850         switch (type) {
1851         case TOMOYO_DOMAINPOLICY:
1852                 /* /sys/kernel/security/tomoyo/domain_policy */
1853                 head->write = tomoyo_write_domain_policy;
1854                 head->read = tomoyo_read_domain_policy;
1855                 break;
1856         case TOMOYO_EXCEPTIONPOLICY:
1857                 /* /sys/kernel/security/tomoyo/exception_policy */
1858                 head->write = tomoyo_write_exception_policy;
1859                 head->read = tomoyo_read_exception_policy;
1860                 break;
1861         case TOMOYO_SELFDOMAIN:
1862                 /* /sys/kernel/security/tomoyo/self_domain */
1863                 head->read = tomoyo_read_self_domain;
1864                 break;
1865         case TOMOYO_DOMAIN_STATUS:
1866                 /* /sys/kernel/security/tomoyo/.domain_status */
1867                 head->write = tomoyo_write_domain_profile;
1868                 head->read = tomoyo_read_domain_profile;
1869                 break;
1870         case TOMOYO_PROCESS_STATUS:
1871                 /* /sys/kernel/security/tomoyo/.process_status */
1872                 head->write = tomoyo_write_pid;
1873                 head->read = tomoyo_read_pid;
1874                 break;
1875         case TOMOYO_VERSION:
1876                 /* /sys/kernel/security/tomoyo/version */
1877                 head->read = tomoyo_read_version;
1878                 head->readbuf_size = 128;
1879                 break;
1880         case TOMOYO_MEMINFO:
1881                 /* /sys/kernel/security/tomoyo/meminfo */
1882                 head->write = tomoyo_write_memory_quota;
1883                 head->read = tomoyo_read_memory_counter;
1884                 head->readbuf_size = 512;
1885                 break;
1886         case TOMOYO_PROFILE:
1887                 /* /sys/kernel/security/tomoyo/profile */
1888                 head->write = tomoyo_write_profile;
1889                 head->read = tomoyo_read_profile;
1890                 break;
1891         case TOMOYO_MANAGER:
1892                 /* /sys/kernel/security/tomoyo/manager */
1893                 head->write = tomoyo_write_manager_policy;
1894                 head->read = tomoyo_read_manager_policy;
1895                 break;
1896         }
1897         if (!(file->f_mode & FMODE_READ)) {
1898                 /*
1899                  * No need to allocate read_buf since it is not opened
1900                  * for reading.
1901                  */
1902                 head->read = NULL;
1903         } else {
1904                 if (!head->readbuf_size)
1905                         head->readbuf_size = 4096 * 2;
1906                 head->read_buf = tomoyo_alloc(head->readbuf_size);
1907                 if (!head->read_buf) {
1908                         tomoyo_free(head);
1909                         return -ENOMEM;
1910                 }
1911         }
1912         if (!(file->f_mode & FMODE_WRITE)) {
1913                 /*
1914                  * No need to allocate write_buf since it is not opened
1915                  * for writing.
1916                  */
1917                 head->write = NULL;
1918         } else if (head->write) {
1919                 head->writebuf_size = 4096 * 2;
1920                 head->write_buf = tomoyo_alloc(head->writebuf_size);
1921                 if (!head->write_buf) {
1922                         tomoyo_free(head->read_buf);
1923                         tomoyo_free(head);
1924                         return -ENOMEM;
1925                 }
1926         }
1927         file->private_data = head;
1928         /*
1929          * Call the handler now if the file is
1930          * /sys/kernel/security/tomoyo/self_domain
1931          * so that the user can use
1932          * cat < /sys/kernel/security/tomoyo/self_domain"
1933          * to know the current process's domainname.
1934          */
1935         if (type == TOMOYO_SELFDOMAIN)
1936                 tomoyo_read_control(file, NULL, 0);
1937         return 0;
1938 }
1939
1940 /**
1941  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
1942  *
1943  * @file:       Pointer to "struct file".
1944  * @buffer:     Poiner to buffer to write to.
1945  * @buffer_len: Size of @buffer.
1946  *
1947  * Returns bytes read on success, negative value otherwise.
1948  */
1949 static int tomoyo_read_control(struct file *file, char __user *buffer,
1950                                const int buffer_len)
1951 {
1952         int len = 0;
1953         struct tomoyo_io_buffer *head = file->private_data;
1954         char *cp;
1955
1956         if (!head->read)
1957                 return -ENOSYS;
1958         if (mutex_lock_interruptible(&head->io_sem))
1959                 return -EINTR;
1960         /* Call the policy handler. */
1961         len = head->read(head);
1962         if (len < 0)
1963                 goto out;
1964         /* Write to buffer. */
1965         len = head->read_avail;
1966         if (len > buffer_len)
1967                 len = buffer_len;
1968         if (!len)
1969                 goto out;
1970         /* head->read_buf changes by some functions. */
1971         cp = head->read_buf;
1972         if (copy_to_user(buffer, cp, len)) {
1973                 len = -EFAULT;
1974                 goto out;
1975         }
1976         head->read_avail -= len;
1977         memmove(cp, cp + len, head->read_avail);
1978  out:
1979         mutex_unlock(&head->io_sem);
1980         return len;
1981 }
1982
1983 /**
1984  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
1985  *
1986  * @file:       Pointer to "struct file".
1987  * @buffer:     Pointer to buffer to read from.
1988  * @buffer_len: Size of @buffer.
1989  *
1990  * Returns @buffer_len on success, negative value otherwise.
1991  */
1992 static int tomoyo_write_control(struct file *file, const char __user *buffer,
1993                                 const int buffer_len)
1994 {
1995         struct tomoyo_io_buffer *head = file->private_data;
1996         int error = buffer_len;
1997         int avail_len = buffer_len;
1998         char *cp0 = head->write_buf;
1999
2000         if (!head->write)
2001                 return -ENOSYS;
2002         if (!access_ok(VERIFY_READ, buffer, buffer_len))
2003                 return -EFAULT;
2004         /* Don't allow updating policies by non manager programs. */
2005         if (head->write != tomoyo_write_pid &&
2006             head->write != tomoyo_write_domain_policy &&
2007             !tomoyo_is_policy_manager())
2008                 return -EPERM;
2009         if (mutex_lock_interruptible(&head->io_sem))
2010                 return -EINTR;
2011         /* Read a line and dispatch it to the policy handler. */
2012         while (avail_len > 0) {
2013                 char c;
2014                 if (head->write_avail >= head->writebuf_size - 1) {
2015                         error = -ENOMEM;
2016                         break;
2017                 } else if (get_user(c, buffer)) {
2018                         error = -EFAULT;
2019                         break;
2020                 }
2021                 buffer++;
2022                 avail_len--;
2023                 cp0[head->write_avail++] = c;
2024                 if (c != '\n')
2025                         continue;
2026                 cp0[head->write_avail - 1] = '\0';
2027                 head->write_avail = 0;
2028                 tomoyo_normalize_line(cp0);
2029                 head->write(head);
2030         }
2031         mutex_unlock(&head->io_sem);
2032         return error;
2033 }
2034
2035 /**
2036  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2037  *
2038  * @file: Pointer to "struct file".
2039  *
2040  * Releases memory and returns 0.
2041  */
2042 static int tomoyo_close_control(struct file *file)
2043 {
2044         struct tomoyo_io_buffer *head = file->private_data;
2045
2046         /* Release memory used for policy I/O. */
2047         tomoyo_free(head->read_buf);
2048         head->read_buf = NULL;
2049         tomoyo_free(head->write_buf);
2050         head->write_buf = NULL;
2051         tomoyo_free(head);
2052         head = NULL;
2053         file->private_data = NULL;
2054         return 0;
2055 }
2056
2057 /**
2058  * tomoyo_alloc_acl_element - Allocate permanent memory for ACL entry.
2059  *
2060  * @acl_type:  Type of ACL entry.
2061  *
2062  * Returns pointer to the ACL entry on success, NULL otherwise.
2063  */
2064 void *tomoyo_alloc_acl_element(const u8 acl_type)
2065 {
2066         int len;
2067         struct tomoyo_acl_info *ptr;
2068
2069         switch (acl_type) {
2070         case TOMOYO_TYPE_SINGLE_PATH_ACL:
2071                 len = sizeof(struct tomoyo_single_path_acl_record);
2072                 break;
2073         case TOMOYO_TYPE_DOUBLE_PATH_ACL:
2074                 len = sizeof(struct tomoyo_double_path_acl_record);
2075                 break;
2076         default:
2077                 return NULL;
2078         }
2079         ptr = tomoyo_alloc_element(len);
2080         if (!ptr)
2081                 return NULL;
2082         ptr->type = acl_type;
2083         return ptr;
2084 }
2085
2086 /**
2087  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2088  *
2089  * @inode: Pointer to "struct inode".
2090  * @file:  Pointer to "struct file".
2091  *
2092  * Returns 0 on success, negative value otherwise.
2093  */
2094 static int tomoyo_open(struct inode *inode, struct file *file)
2095 {
2096         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2097                 - ((u8 *) NULL);
2098         return tomoyo_open_control(key, file);
2099 }
2100
2101 /**
2102  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2103  *
2104  * @inode: Pointer to "struct inode".
2105  * @file:  Pointer to "struct file".
2106  *
2107  * Returns 0 on success, negative value otherwise.
2108  */
2109 static int tomoyo_release(struct inode *inode, struct file *file)
2110 {
2111         return tomoyo_close_control(file);
2112 }
2113
2114 /**
2115  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2116  *
2117  * @file:  Pointer to "struct file".
2118  * @buf:   Pointer to buffer.
2119  * @count: Size of @buf.
2120  * @ppos:  Unused.
2121  *
2122  * Returns bytes read on success, negative value otherwise.
2123  */
2124 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2125                            loff_t *ppos)
2126 {
2127         return tomoyo_read_control(file, buf, count);
2128 }
2129
2130 /**
2131  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2132  *
2133  * @file:  Pointer to "struct file".
2134  * @buf:   Pointer to buffer.
2135  * @count: Size of @buf.
2136  * @ppos:  Unused.
2137  *
2138  * Returns @count on success, negative value otherwise.
2139  */
2140 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2141                             size_t count, loff_t *ppos)
2142 {
2143         return tomoyo_write_control(file, buf, count);
2144 }
2145
2146 /* Operations for /sys/kernel/security/tomoyo/ interface. */
2147 static const struct file_operations tomoyo_operations = {
2148         .open    = tomoyo_open,
2149         .release = tomoyo_release,
2150         .read    = tomoyo_read,
2151         .write   = tomoyo_write,
2152 };
2153
2154 /**
2155  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2156  *
2157  * @name:   The name of the interface file.
2158  * @mode:   The permission of the interface file.
2159  * @parent: The parent directory.
2160  * @key:    Type of interface.
2161  *
2162  * Returns nothing.
2163  */
2164 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2165                                        struct dentry *parent, const u8 key)
2166 {
2167         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2168                                &tomoyo_operations);
2169 }
2170
2171 /**
2172  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2173  *
2174  * Returns 0.
2175  */
2176 static int __init tomoyo_initerface_init(void)
2177 {
2178         struct dentry *tomoyo_dir;
2179
2180         /* Don't create securityfs entries unless registered. */
2181         if (current_cred()->security != &tomoyo_kernel_domain)
2182                 return 0;
2183
2184         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2185         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2186                             TOMOYO_DOMAINPOLICY);
2187         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2188                             TOMOYO_EXCEPTIONPOLICY);
2189         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2190                             TOMOYO_SELFDOMAIN);
2191         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2192                             TOMOYO_DOMAIN_STATUS);
2193         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2194                             TOMOYO_PROCESS_STATUS);
2195         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2196                             TOMOYO_MEMINFO);
2197         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2198                             TOMOYO_PROFILE);
2199         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2200                             TOMOYO_MANAGER);
2201         tomoyo_create_entry("version",          0400, tomoyo_dir,
2202                             TOMOYO_VERSION);
2203         return 0;
2204 }
2205
2206 fs_initcall(tomoyo_initerface_init);