xref: /linux/security/tomoyo/common.c (revision 97c1cf8fdbce332bfacc3e38aae3fe2af1369906)
1 /*
2  * security/tomoyo/common.c
3  *
4  * Common functions for TOMOYO.
5  *
6  * Copyright (C) 2005-2010  NTT DATA CORPORATION
7  */
8 
9 #include <linux/uaccess.h>
10 #include <linux/slab.h>
11 #include <linux/security.h>
12 #include "common.h"
13 
14 static struct tomoyo_profile tomoyo_default_profile = {
15 	.learning = &tomoyo_default_profile.preference,
16 	.permissive = &tomoyo_default_profile.preference,
17 	.enforcing = &tomoyo_default_profile.preference,
18 	.preference.enforcing_verbose = true,
19 	.preference.learning_max_entry = 2048,
20 	.preference.learning_verbose = false,
21 	.preference.permissive_verbose = true
22 };
23 
24 /* Profile version. Currently only 20090903 is defined. */
25 static unsigned int tomoyo_profile_version;
26 
27 /* Profile table. Memory is allocated as needed. */
28 static struct tomoyo_profile *tomoyo_profile_ptr[TOMOYO_MAX_PROFILES];
29 
30 /* String table for functionality that takes 4 modes. */
31 static const char *tomoyo_mode[4] = {
32 	"disabled", "learning", "permissive", "enforcing"
33 };
34 
35 /* String table for /sys/kernel/security/tomoyo/profile */
36 static const char *tomoyo_mac_keywords[TOMOYO_MAX_MAC_INDEX
37 				       + TOMOYO_MAX_MAC_CATEGORY_INDEX] = {
38 	[TOMOYO_MAC_FILE_EXECUTE]    = "file::execute",
39 	[TOMOYO_MAC_FILE_OPEN]       = "file::open",
40 	[TOMOYO_MAC_FILE_CREATE]     = "file::create",
41 	[TOMOYO_MAC_FILE_UNLINK]     = "file::unlink",
42 	[TOMOYO_MAC_FILE_MKDIR]      = "file::mkdir",
43 	[TOMOYO_MAC_FILE_RMDIR]      = "file::rmdir",
44 	[TOMOYO_MAC_FILE_MKFIFO]     = "file::mkfifo",
45 	[TOMOYO_MAC_FILE_MKSOCK]     = "file::mksock",
46 	[TOMOYO_MAC_FILE_TRUNCATE]   = "file::truncate",
47 	[TOMOYO_MAC_FILE_SYMLINK]    = "file::symlink",
48 	[TOMOYO_MAC_FILE_REWRITE]    = "file::rewrite",
49 	[TOMOYO_MAC_FILE_MKBLOCK]    = "file::mkblock",
50 	[TOMOYO_MAC_FILE_MKCHAR]     = "file::mkchar",
51 	[TOMOYO_MAC_FILE_LINK]       = "file::link",
52 	[TOMOYO_MAC_FILE_RENAME]     = "file::rename",
53 	[TOMOYO_MAC_FILE_CHMOD]      = "file::chmod",
54 	[TOMOYO_MAC_FILE_CHOWN]      = "file::chown",
55 	[TOMOYO_MAC_FILE_CHGRP]      = "file::chgrp",
56 	[TOMOYO_MAC_FILE_IOCTL]      = "file::ioctl",
57 	[TOMOYO_MAC_FILE_CHROOT]     = "file::chroot",
58 	[TOMOYO_MAC_FILE_MOUNT]      = "file::mount",
59 	[TOMOYO_MAC_FILE_UMOUNT]     = "file::umount",
60 	[TOMOYO_MAC_FILE_PIVOT_ROOT] = "file::pivot_root",
61 	[TOMOYO_MAX_MAC_INDEX + TOMOYO_MAC_CATEGORY_FILE] = "file",
62 };
63 
64 /* Permit policy management by non-root user? */
65 static bool tomoyo_manage_by_non_root;
66 
67 /* Utility functions. */
68 
69 /**
70  * tomoyo_yesno - Return "yes" or "no".
71  *
72  * @value: Bool value.
73  */
74 static const char *tomoyo_yesno(const unsigned int value)
75 {
76 	return value ? "yes" : "no";
77 }
78 
79 static void tomoyo_addprintf(char *buffer, int len, const char *fmt, ...)
80 {
81 	va_list args;
82 	const int pos = strlen(buffer);
83 	va_start(args, fmt);
84 	vsnprintf(buffer + pos, len - pos - 1, fmt, args);
85 	va_end(args);
86 }
87 
88 /**
89  * tomoyo_flush - Flush queued string to userspace's buffer.
90  *
91  * @head:   Pointer to "struct tomoyo_io_buffer".
92  *
93  * Returns true if all data was flushed, false otherwise.
94  */
95 static bool tomoyo_flush(struct tomoyo_io_buffer *head)
96 {
97 	while (head->r.w_pos) {
98 		const char *w = head->r.w[0];
99 		int len = strlen(w);
100 		if (len) {
101 			if (len > head->read_user_buf_avail)
102 				len = head->read_user_buf_avail;
103 			if (!len)
104 				return false;
105 			if (copy_to_user(head->read_user_buf, w, len))
106 				return false;
107 			head->read_user_buf_avail -= len;
108 			head->read_user_buf += len;
109 			w += len;
110 		}
111 		if (*w) {
112 			head->r.w[0] = w;
113 			return false;
114 		}
115 		/* Add '\0' for query. */
116 		if (head->poll) {
117 			if (!head->read_user_buf_avail ||
118 			    copy_to_user(head->read_user_buf, "", 1))
119 				return false;
120 			head->read_user_buf_avail--;
121 			head->read_user_buf++;
122 		}
123 		head->r.w_pos--;
124 		for (len = 0; len < head->r.w_pos; len++)
125 			head->r.w[len] = head->r.w[len + 1];
126 	}
127 	head->r.avail = 0;
128 	return true;
129 }
130 
131 /**
132  * tomoyo_set_string - Queue string to "struct tomoyo_io_buffer" structure.
133  *
134  * @head:   Pointer to "struct tomoyo_io_buffer".
135  * @string: String to print.
136  *
137  * Note that @string has to be kept valid until @head is kfree()d.
138  * This means that char[] allocated on stack memory cannot be passed to
139  * this function. Use tomoyo_io_printf() for char[] allocated on stack memory.
140  */
141 static void tomoyo_set_string(struct tomoyo_io_buffer *head, const char *string)
142 {
143 	if (head->r.w_pos < TOMOYO_MAX_IO_READ_QUEUE) {
144 		head->r.w[head->r.w_pos++] = string;
145 		tomoyo_flush(head);
146 	} else
147 		WARN_ON(1);
148 }
149 
150 /**
151  * tomoyo_io_printf - printf() to "struct tomoyo_io_buffer" structure.
152  *
153  * @head: Pointer to "struct tomoyo_io_buffer".
154  * @fmt:  The printf()'s format string, followed by parameters.
155  */
156 void tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
157 {
158 	va_list args;
159 	int len;
160 	int pos = head->r.avail;
161 	int size = head->readbuf_size - pos;
162 	if (size <= 0)
163 		return;
164 	va_start(args, fmt);
165 	len = vsnprintf(head->read_buf + pos, size, fmt, args) + 1;
166 	va_end(args);
167 	if (pos + len >= head->readbuf_size) {
168 		WARN_ON(1);
169 		return;
170 	}
171 	head->r.avail += len;
172 	tomoyo_set_string(head, head->read_buf + pos);
173 }
174 
175 static void tomoyo_set_space(struct tomoyo_io_buffer *head)
176 {
177 	tomoyo_set_string(head, " ");
178 }
179 
180 static bool tomoyo_set_lf(struct tomoyo_io_buffer *head)
181 {
182 	tomoyo_set_string(head, "\n");
183 	return !head->r.w_pos;
184 }
185 
186 /**
187  * tomoyo_print_name_union - Print a tomoyo_name_union.
188  *
189  * @head: Pointer to "struct tomoyo_io_buffer".
190  * @ptr:  Pointer to "struct tomoyo_name_union".
191  */
192 static void tomoyo_print_name_union(struct tomoyo_io_buffer *head,
193 				    const struct tomoyo_name_union *ptr)
194 {
195 	tomoyo_set_space(head);
196 	if (ptr->is_group) {
197 		tomoyo_set_string(head, "@");
198 		tomoyo_set_string(head, ptr->group->group_name->name);
199 	} else {
200 		tomoyo_set_string(head, ptr->filename->name);
201 	}
202 }
203 
204 /**
205  * tomoyo_print_number_union - Print a tomoyo_number_union.
206  *
207  * @head:       Pointer to "struct tomoyo_io_buffer".
208  * @ptr:        Pointer to "struct tomoyo_number_union".
209  */
210 static void tomoyo_print_number_union(struct tomoyo_io_buffer *head,
211 				      const struct tomoyo_number_union *ptr)
212 {
213 	tomoyo_set_space(head);
214 	if (ptr->is_group) {
215 		tomoyo_set_string(head, "@");
216 		tomoyo_set_string(head, ptr->group->group_name->name);
217 	} else {
218 		int i;
219 		unsigned long min = ptr->values[0];
220 		const unsigned long max = ptr->values[1];
221 		u8 min_type = ptr->min_type;
222 		const u8 max_type = ptr->max_type;
223 		char buffer[128];
224 		buffer[0] = '\0';
225 		for (i = 0; i < 2; i++) {
226 			switch (min_type) {
227 			case TOMOYO_VALUE_TYPE_HEXADECIMAL:
228 				tomoyo_addprintf(buffer, sizeof(buffer),
229 						 "0x%lX", min);
230 				break;
231 			case TOMOYO_VALUE_TYPE_OCTAL:
232 				tomoyo_addprintf(buffer, sizeof(buffer),
233 						 "0%lo", min);
234 				break;
235 			default:
236 				tomoyo_addprintf(buffer, sizeof(buffer),
237 						 "%lu", min);
238 				break;
239 			}
240 			if (min == max && min_type == max_type)
241 				break;
242 			tomoyo_addprintf(buffer, sizeof(buffer), "-");
243 			min_type = max_type;
244 			min = max;
245 		}
246 		tomoyo_io_printf(head, "%s", buffer);
247 	}
248 }
249 
250 /**
251  * tomoyo_assign_profile - Create a new profile.
252  *
253  * @profile: Profile number to create.
254  *
255  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
256  */
257 static struct tomoyo_profile *tomoyo_assign_profile(const unsigned int profile)
258 {
259 	struct tomoyo_profile *ptr;
260 	struct tomoyo_profile *entry;
261 	if (profile >= TOMOYO_MAX_PROFILES)
262 		return NULL;
263 	ptr = tomoyo_profile_ptr[profile];
264 	if (ptr)
265 		return ptr;
266 	entry = kzalloc(sizeof(*entry), GFP_NOFS);
267 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
268 		goto out;
269 	ptr = tomoyo_profile_ptr[profile];
270 	if (!ptr && tomoyo_memory_ok(entry)) {
271 		ptr = entry;
272 		ptr->learning = &tomoyo_default_profile.preference;
273 		ptr->permissive = &tomoyo_default_profile.preference;
274 		ptr->enforcing = &tomoyo_default_profile.preference;
275 		ptr->default_config = TOMOYO_CONFIG_DISABLED;
276 		memset(ptr->config, TOMOYO_CONFIG_USE_DEFAULT,
277 		       sizeof(ptr->config));
278 		mb(); /* Avoid out-of-order execution. */
279 		tomoyo_profile_ptr[profile] = ptr;
280 		entry = NULL;
281 	}
282 	mutex_unlock(&tomoyo_policy_lock);
283  out:
284 	kfree(entry);
285 	return ptr;
286 }
287 
288 /**
289  * tomoyo_profile - Find a profile.
290  *
291  * @profile: Profile number to find.
292  *
293  * Returns pointer to "struct tomoyo_profile".
294  */
295 struct tomoyo_profile *tomoyo_profile(const u8 profile)
296 {
297 	struct tomoyo_profile *ptr = tomoyo_profile_ptr[profile];
298 	if (!tomoyo_policy_loaded)
299 		return &tomoyo_default_profile;
300 	BUG_ON(!ptr);
301 	return ptr;
302 }
303 
304 static s8 tomoyo_find_yesno(const char *string, const char *find)
305 {
306 	const char *cp = strstr(string, find);
307 	if (cp) {
308 		cp += strlen(find);
309 		if (!strncmp(cp, "=yes", 4))
310 			return 1;
311 		else if (!strncmp(cp, "=no", 3))
312 			return 0;
313 	}
314 	return -1;
315 }
316 
317 static void tomoyo_set_bool(bool *b, const char *string, const char *find)
318 {
319 	switch (tomoyo_find_yesno(string, find)) {
320 	case 1:
321 		*b = true;
322 		break;
323 	case 0:
324 		*b = false;
325 		break;
326 	}
327 }
328 
329 static void tomoyo_set_uint(unsigned int *i, const char *string,
330 			    const char *find)
331 {
332 	const char *cp = strstr(string, find);
333 	if (cp)
334 		sscanf(cp + strlen(find), "=%u", i);
335 }
336 
337 static void tomoyo_set_pref(const char *name, const char *value,
338 			    const bool use_default,
339 			    struct tomoyo_profile *profile)
340 {
341 	struct tomoyo_preference **pref;
342 	bool *verbose;
343 	if (!strcmp(name, "enforcing")) {
344 		if (use_default) {
345 			pref = &profile->enforcing;
346 			goto set_default;
347 		}
348 		profile->enforcing = &profile->preference;
349 		verbose = &profile->preference.enforcing_verbose;
350 		goto set_verbose;
351 	}
352 	if (!strcmp(name, "permissive")) {
353 		if (use_default) {
354 			pref = &profile->permissive;
355 			goto set_default;
356 		}
357 		profile->permissive = &profile->preference;
358 		verbose = &profile->preference.permissive_verbose;
359 		goto set_verbose;
360 	}
361 	if (!strcmp(name, "learning")) {
362 		if (use_default) {
363 			pref = &profile->learning;
364 			goto set_default;
365 		}
366 		profile->learning = &profile->preference;
367 		tomoyo_set_uint(&profile->preference.learning_max_entry, value,
368 			     "max_entry");
369 		verbose = &profile->preference.learning_verbose;
370 		goto set_verbose;
371 	}
372 	return;
373  set_default:
374 	*pref = &tomoyo_default_profile.preference;
375 	return;
376  set_verbose:
377 	tomoyo_set_bool(verbose, value, "verbose");
378 }
379 
380 static int tomoyo_set_mode(char *name, const char *value,
381 			   const bool use_default,
382 			   struct tomoyo_profile *profile)
383 {
384 	u8 i;
385 	u8 config;
386 	if (!strcmp(name, "CONFIG")) {
387 		i = TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX;
388 		config = profile->default_config;
389 	} else if (tomoyo_str_starts(&name, "CONFIG::")) {
390 		config = 0;
391 		for (i = 0; i < TOMOYO_MAX_MAC_INDEX
392 			     + TOMOYO_MAX_MAC_CATEGORY_INDEX; i++) {
393 			if (strcmp(name, tomoyo_mac_keywords[i]))
394 				continue;
395 			config = profile->config[i];
396 			break;
397 		}
398 		if (i == TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX)
399 			return -EINVAL;
400 	} else {
401 		return -EINVAL;
402 	}
403 	if (use_default) {
404 		config = TOMOYO_CONFIG_USE_DEFAULT;
405 	} else {
406 		u8 mode;
407 		for (mode = 0; mode < 4; mode++)
408 			if (strstr(value, tomoyo_mode[mode]))
409 				/*
410 				 * Update lower 3 bits in order to distinguish
411 				 * 'config' from 'TOMOYO_CONFIG_USE_DEAFULT'.
412 				 */
413 				config = (config & ~7) | mode;
414 	}
415 	if (i < TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX)
416 		profile->config[i] = config;
417 	else if (config != TOMOYO_CONFIG_USE_DEFAULT)
418 		profile->default_config = config;
419 	return 0;
420 }
421 
422 /**
423  * tomoyo_write_profile - Write profile table.
424  *
425  * @head: Pointer to "struct tomoyo_io_buffer".
426  *
427  * Returns 0 on success, negative value otherwise.
428  */
429 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
430 {
431 	char *data = head->write_buf;
432 	unsigned int i;
433 	bool use_default = false;
434 	char *cp;
435 	struct tomoyo_profile *profile;
436 	if (sscanf(data, "PROFILE_VERSION=%u", &tomoyo_profile_version) == 1)
437 		return 0;
438 	i = simple_strtoul(data, &cp, 10);
439 	if (data == cp) {
440 		profile = &tomoyo_default_profile;
441 	} else {
442 		if (*cp != '-')
443 			return -EINVAL;
444 		data = cp + 1;
445 		profile = tomoyo_assign_profile(i);
446 		if (!profile)
447 			return -EINVAL;
448 	}
449 	cp = strchr(data, '=');
450 	if (!cp)
451 		return -EINVAL;
452 	*cp++ = '\0';
453 	if (profile != &tomoyo_default_profile)
454 		use_default = strstr(cp, "use_default") != NULL;
455 	if (tomoyo_str_starts(&data, "PREFERENCE::")) {
456 		tomoyo_set_pref(data, cp, use_default, profile);
457 		return 0;
458 	}
459 	if (profile == &tomoyo_default_profile)
460 		return -EINVAL;
461 	if (!strcmp(data, "COMMENT")) {
462 		const struct tomoyo_path_info *old_comment = profile->comment;
463 		profile->comment = tomoyo_get_name(cp);
464 		tomoyo_put_name(old_comment);
465 		return 0;
466 	}
467 	return tomoyo_set_mode(data, cp, use_default, profile);
468 }
469 
470 static void tomoyo_print_preference(struct tomoyo_io_buffer *head,
471 				    const int idx)
472 {
473 	struct tomoyo_preference *pref = &tomoyo_default_profile.preference;
474 	const struct tomoyo_profile *profile = idx >= 0 ?
475 		tomoyo_profile_ptr[idx] : NULL;
476 	char buffer[16] = "";
477 	if (profile) {
478 		buffer[sizeof(buffer) - 1] = '\0';
479 		snprintf(buffer, sizeof(buffer) - 1, "%u-", idx);
480 	}
481 	if (profile) {
482 		pref = profile->learning;
483 		if (pref == &tomoyo_default_profile.preference)
484 			goto skip1;
485 	}
486 	tomoyo_io_printf(head, "%sPREFERENCE::%s={ "
487 			 "verbose=%s max_entry=%u }\n",
488 			 buffer, "learning",
489 			 tomoyo_yesno(pref->learning_verbose),
490 			 pref->learning_max_entry);
491  skip1:
492 	if (profile) {
493 		pref = profile->permissive;
494 		if (pref == &tomoyo_default_profile.preference)
495 			goto skip2;
496 	}
497 	tomoyo_io_printf(head, "%sPREFERENCE::%s={ verbose=%s }\n",
498 			 buffer, "permissive",
499 			 tomoyo_yesno(pref->permissive_verbose));
500  skip2:
501 	if (profile) {
502 		pref = profile->enforcing;
503 		if (pref == &tomoyo_default_profile.preference)
504 			return;
505 	}
506 	tomoyo_io_printf(head, "%sPREFERENCE::%s={ verbose=%s }\n",
507 			 buffer, "enforcing",
508 			 tomoyo_yesno(pref->enforcing_verbose));
509 }
510 
511 static void tomoyo_print_config(struct tomoyo_io_buffer *head, const u8 config)
512 {
513 	tomoyo_io_printf(head, "={ mode=%s }\n", tomoyo_mode[config & 3]);
514 }
515 
516 /**
517  * tomoyo_read_profile - Read profile table.
518  *
519  * @head: Pointer to "struct tomoyo_io_buffer".
520  */
521 static void tomoyo_read_profile(struct tomoyo_io_buffer *head)
522 {
523 	u8 index;
524 	const struct tomoyo_profile *profile;
525  next:
526 	index = head->r.index;
527 	profile = tomoyo_profile_ptr[index];
528 	switch (head->r.step) {
529 	case 0:
530 		tomoyo_io_printf(head, "PROFILE_VERSION=%s\n", "20090903");
531 		tomoyo_print_preference(head, -1);
532 		head->r.step++;
533 		break;
534 	case 1:
535 		for ( ; head->r.index < TOMOYO_MAX_PROFILES;
536 		      head->r.index++)
537 			if (tomoyo_profile_ptr[head->r.index])
538 				break;
539 		if (head->r.index == TOMOYO_MAX_PROFILES)
540 			return;
541 		head->r.step++;
542 		break;
543 	case 2:
544 		{
545 			const struct tomoyo_path_info *comment =
546 				profile->comment;
547 			tomoyo_io_printf(head, "%u-COMMENT=", index);
548 			tomoyo_set_string(head, comment ? comment->name : "");
549 			tomoyo_set_lf(head);
550 			head->r.step++;
551 		}
552 		break;
553 	case 3:
554 		{
555 			tomoyo_io_printf(head, "%u-%s", index, "CONFIG");
556 			tomoyo_print_config(head, profile->default_config);
557 			head->r.bit = 0;
558 			head->r.step++;
559 		}
560 		break;
561 	case 4:
562 		for ( ; head->r.bit < TOMOYO_MAX_MAC_INDEX
563 			      + TOMOYO_MAX_MAC_CATEGORY_INDEX; head->r.bit++) {
564 			const u8 i = head->r.bit;
565 			const u8 config = profile->config[i];
566 			if (config == TOMOYO_CONFIG_USE_DEFAULT)
567 				continue;
568 			tomoyo_io_printf(head, "%u-%s%s", index, "CONFIG::",
569 					 tomoyo_mac_keywords[i]);
570 			tomoyo_print_config(head, config);
571 			head->r.bit++;
572 			break;
573 		}
574 		if (head->r.bit == TOMOYO_MAX_MAC_INDEX
575 		    + TOMOYO_MAX_MAC_CATEGORY_INDEX) {
576 			tomoyo_print_preference(head, index);
577 			head->r.index++;
578 			head->r.step = 1;
579 		}
580 		break;
581 	}
582 	if (tomoyo_flush(head))
583 		goto next;
584 }
585 
586 static bool tomoyo_same_manager(const struct tomoyo_acl_head *a,
587 				const struct tomoyo_acl_head *b)
588 {
589 	return container_of(a, struct tomoyo_manager, head)->manager ==
590 		container_of(b, struct tomoyo_manager, head)->manager;
591 }
592 
593 /**
594  * tomoyo_update_manager_entry - Add a manager entry.
595  *
596  * @manager:   The path to manager or the domainnamme.
597  * @is_delete: True if it is a delete request.
598  *
599  * Returns 0 on success, negative value otherwise.
600  *
601  * Caller holds tomoyo_read_lock().
602  */
603 static int tomoyo_update_manager_entry(const char *manager,
604 				       const bool is_delete)
605 {
606 	struct tomoyo_manager e = { };
607 	int error;
608 
609 	if (tomoyo_domain_def(manager)) {
610 		if (!tomoyo_correct_domain(manager))
611 			return -EINVAL;
612 		e.is_domain = true;
613 	} else {
614 		if (!tomoyo_correct_path(manager))
615 			return -EINVAL;
616 	}
617 	e.manager = tomoyo_get_name(manager);
618 	if (!e.manager)
619 		return -ENOMEM;
620 	error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
621 				     &tomoyo_policy_list[TOMOYO_ID_MANAGER],
622 				     tomoyo_same_manager);
623 	tomoyo_put_name(e.manager);
624 	return error;
625 }
626 
627 /**
628  * tomoyo_write_manager - Write manager policy.
629  *
630  * @head: Pointer to "struct tomoyo_io_buffer".
631  *
632  * Returns 0 on success, negative value otherwise.
633  *
634  * Caller holds tomoyo_read_lock().
635  */
636 static int tomoyo_write_manager(struct tomoyo_io_buffer *head)
637 {
638 	char *data = head->write_buf;
639 	bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
640 
641 	if (!strcmp(data, "manage_by_non_root")) {
642 		tomoyo_manage_by_non_root = !is_delete;
643 		return 0;
644 	}
645 	return tomoyo_update_manager_entry(data, is_delete);
646 }
647 
648 /**
649  * tomoyo_read_manager - Read manager policy.
650  *
651  * @head: Pointer to "struct tomoyo_io_buffer".
652  *
653  * Caller holds tomoyo_read_lock().
654  */
655 static void tomoyo_read_manager(struct tomoyo_io_buffer *head)
656 {
657 	if (head->r.eof)
658 		return;
659 	list_for_each_cookie(head->r.acl,
660 			     &tomoyo_policy_list[TOMOYO_ID_MANAGER]) {
661 		struct tomoyo_manager *ptr =
662 			list_entry(head->r.acl, typeof(*ptr), head.list);
663 		if (ptr->head.is_deleted)
664 			continue;
665 		if (!tomoyo_flush(head))
666 			return;
667 		tomoyo_set_string(head, ptr->manager->name);
668 		tomoyo_set_lf(head);
669 	}
670 	head->r.eof = true;
671 }
672 
673 /**
674  * tomoyo_manager - Check whether the current process is a policy manager.
675  *
676  * Returns true if the current process is permitted to modify policy
677  * via /sys/kernel/security/tomoyo/ interface.
678  *
679  * Caller holds tomoyo_read_lock().
680  */
681 static bool tomoyo_manager(void)
682 {
683 	struct tomoyo_manager *ptr;
684 	const char *exe;
685 	const struct task_struct *task = current;
686 	const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
687 	bool found = false;
688 
689 	if (!tomoyo_policy_loaded)
690 		return true;
691 	if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
692 		return false;
693 	list_for_each_entry_rcu(ptr, &tomoyo_policy_list[TOMOYO_ID_MANAGER],
694 				head.list) {
695 		if (!ptr->head.is_deleted && ptr->is_domain
696 		    && !tomoyo_pathcmp(domainname, ptr->manager)) {
697 			found = true;
698 			break;
699 		}
700 	}
701 	if (found)
702 		return true;
703 	exe = tomoyo_get_exe();
704 	if (!exe)
705 		return false;
706 	list_for_each_entry_rcu(ptr, &tomoyo_policy_list[TOMOYO_ID_MANAGER],
707 				head.list) {
708 		if (!ptr->head.is_deleted && !ptr->is_domain
709 		    && !strcmp(exe, ptr->manager->name)) {
710 			found = true;
711 			break;
712 		}
713 	}
714 	if (!found) { /* Reduce error messages. */
715 		static pid_t last_pid;
716 		const pid_t pid = current->pid;
717 		if (last_pid != pid) {
718 			printk(KERN_WARNING "%s ( %s ) is not permitted to "
719 			       "update policies.\n", domainname->name, exe);
720 			last_pid = pid;
721 		}
722 	}
723 	kfree(exe);
724 	return found;
725 }
726 
727 /**
728  * tomoyo_select_one - Parse select command.
729  *
730  * @head: Pointer to "struct tomoyo_io_buffer".
731  * @data: String to parse.
732  *
733  * Returns true on success, false otherwise.
734  *
735  * Caller holds tomoyo_read_lock().
736  */
737 static bool tomoyo_select_one(struct tomoyo_io_buffer *head, const char *data)
738 {
739 	unsigned int pid;
740 	struct tomoyo_domain_info *domain = NULL;
741 	bool global_pid = false;
742 
743 	if (!strcmp(data, "allow_execute")) {
744 		head->r.print_execute_only = true;
745 		return true;
746 	}
747 	if (sscanf(data, "pid=%u", &pid) == 1 ||
748 	    (global_pid = true, sscanf(data, "global-pid=%u", &pid) == 1)) {
749 		struct task_struct *p;
750 		rcu_read_lock();
751 		read_lock(&tasklist_lock);
752 		if (global_pid)
753 			p = find_task_by_pid_ns(pid, &init_pid_ns);
754 		else
755 			p = find_task_by_vpid(pid);
756 		if (p)
757 			domain = tomoyo_real_domain(p);
758 		read_unlock(&tasklist_lock);
759 		rcu_read_unlock();
760 	} else if (!strncmp(data, "domain=", 7)) {
761 		if (tomoyo_domain_def(data + 7))
762 			domain = tomoyo_find_domain(data + 7);
763 	} else
764 		return false;
765 	head->write_var1 = domain;
766 	/* Accessing read_buf is safe because head->io_sem is held. */
767 	if (!head->read_buf)
768 		return true; /* Do nothing if open(O_WRONLY). */
769 	memset(&head->r, 0, sizeof(head->r));
770 	head->r.print_this_domain_only = true;
771 	head->r.eof = !domain;
772 	head->r.domain = &domain->list;
773 	tomoyo_io_printf(head, "# select %s\n", data);
774 	if (domain && domain->is_deleted)
775 		tomoyo_io_printf(head, "# This is a deleted domain.\n");
776 	return true;
777 }
778 
779 /**
780  * tomoyo_delete_domain - Delete a domain.
781  *
782  * @domainname: The name of domain.
783  *
784  * Returns 0.
785  *
786  * Caller holds tomoyo_read_lock().
787  */
788 static int tomoyo_delete_domain(char *domainname)
789 {
790 	struct tomoyo_domain_info *domain;
791 	struct tomoyo_path_info name;
792 
793 	name.name = domainname;
794 	tomoyo_fill_path_info(&name);
795 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
796 		return 0;
797 	/* Is there an active domain? */
798 	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
799 		/* Never delete tomoyo_kernel_domain */
800 		if (domain == &tomoyo_kernel_domain)
801 			continue;
802 		if (domain->is_deleted ||
803 		    tomoyo_pathcmp(domain->domainname, &name))
804 			continue;
805 		domain->is_deleted = true;
806 		break;
807 	}
808 	mutex_unlock(&tomoyo_policy_lock);
809 	return 0;
810 }
811 
812 /**
813  * tomoyo_write_domain2 - Write domain policy.
814  *
815  * @head: Pointer to "struct tomoyo_io_buffer".
816  *
817  * Returns 0 on success, negative value otherwise.
818  *
819  * Caller holds tomoyo_read_lock().
820  */
821 static int tomoyo_write_domain2(char *data, struct tomoyo_domain_info *domain,
822 				const bool is_delete)
823 {
824 	if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_MOUNT))
825 		return tomoyo_write_mount(data, domain, is_delete);
826 	return tomoyo_write_file(data, domain, is_delete);
827 }
828 
829 /**
830  * tomoyo_write_domain - Write domain policy.
831  *
832  * @head: Pointer to "struct tomoyo_io_buffer".
833  *
834  * Returns 0 on success, negative value otherwise.
835  *
836  * Caller holds tomoyo_read_lock().
837  */
838 static int tomoyo_write_domain(struct tomoyo_io_buffer *head)
839 {
840 	char *data = head->write_buf;
841 	struct tomoyo_domain_info *domain = head->write_var1;
842 	bool is_delete = false;
843 	bool is_select = false;
844 	unsigned int profile;
845 
846 	if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
847 		is_delete = true;
848 	else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
849 		is_select = true;
850 	if (is_select && tomoyo_select_one(head, data))
851 		return 0;
852 	/* Don't allow updating policies by non manager programs. */
853 	if (!tomoyo_manager())
854 		return -EPERM;
855 	if (tomoyo_domain_def(data)) {
856 		domain = NULL;
857 		if (is_delete)
858 			tomoyo_delete_domain(data);
859 		else if (is_select)
860 			domain = tomoyo_find_domain(data);
861 		else
862 			domain = tomoyo_assign_domain(data, 0);
863 		head->write_var1 = domain;
864 		return 0;
865 	}
866 	if (!domain)
867 		return -EINVAL;
868 
869 	if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
870 	    && profile < TOMOYO_MAX_PROFILES) {
871 		if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
872 			domain->profile = (u8) profile;
873 		return 0;
874 	}
875 	if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
876 		domain->ignore_global_allow_read = !is_delete;
877 		return 0;
878 	}
879 	if (!strcmp(data, TOMOYO_KEYWORD_QUOTA_EXCEEDED)) {
880 		domain->quota_warned = !is_delete;
881 		return 0;
882 	}
883 	if (!strcmp(data, TOMOYO_KEYWORD_TRANSITION_FAILED)) {
884 		domain->transition_failed = !is_delete;
885 		return 0;
886 	}
887 	return tomoyo_write_domain2(data, domain, is_delete);
888 }
889 
890 /**
891  * tomoyo_fns - Find next set bit.
892  *
893  * @perm: 8 bits value.
894  * @bit:  First bit to find.
895  *
896  * Returns next on-bit on success, 8 otherwise.
897  */
898 static u8 tomoyo_fns(const u8 perm, u8 bit)
899 {
900 	for ( ; bit < 8; bit++)
901 		if (perm & (1 << bit))
902 			break;
903 	return bit;
904 }
905 
906 /**
907  * tomoyo_print_entry - Print an ACL entry.
908  *
909  * @head: Pointer to "struct tomoyo_io_buffer".
910  * @acl:  Pointer to an ACL entry.
911  *
912  * Returns true on success, false otherwise.
913  */
914 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
915 			       struct tomoyo_acl_info *acl)
916 {
917 	const u8 acl_type = acl->type;
918 	u8 bit;
919 
920 	if (acl->is_deleted)
921 		return true;
922  next:
923 	bit = head->r.bit;
924 	if (!tomoyo_flush(head))
925 		return false;
926 	else if (acl_type == TOMOYO_TYPE_PATH_ACL) {
927 		struct tomoyo_path_acl *ptr =
928 			container_of(acl, typeof(*ptr), head);
929 		const u16 perm = ptr->perm;
930 		for ( ; bit < TOMOYO_MAX_PATH_OPERATION; bit++) {
931 			if (!(perm & (1 << bit)))
932 				continue;
933 			if (head->r.print_execute_only &&
934 			    bit != TOMOYO_TYPE_EXECUTE)
935 				continue;
936 			/* Print "read/write" instead of "read" and "write". */
937 			if ((bit == TOMOYO_TYPE_READ ||
938 			     bit == TOMOYO_TYPE_WRITE)
939 			    && (perm & (1 << TOMOYO_TYPE_READ_WRITE)))
940 				continue;
941 			break;
942 		}
943 		if (bit >= TOMOYO_MAX_PATH_OPERATION)
944 			goto done;
945 		tomoyo_io_printf(head, "allow_%s", tomoyo_path_keyword[bit]);
946 		tomoyo_print_name_union(head, &ptr->name);
947 	} else if (head->r.print_execute_only) {
948 		return true;
949 	} else if (acl_type == TOMOYO_TYPE_PATH2_ACL) {
950 		struct tomoyo_path2_acl *ptr =
951 			container_of(acl, typeof(*ptr), head);
952 		bit = tomoyo_fns(ptr->perm, bit);
953 		if (bit >= TOMOYO_MAX_PATH2_OPERATION)
954 			goto done;
955 		tomoyo_io_printf(head, "allow_%s", tomoyo_path2_keyword[bit]);
956 		tomoyo_print_name_union(head, &ptr->name1);
957 		tomoyo_print_name_union(head, &ptr->name2);
958 	} else if (acl_type == TOMOYO_TYPE_PATH_NUMBER_ACL) {
959 		struct tomoyo_path_number_acl *ptr =
960 			container_of(acl, typeof(*ptr), head);
961 		bit = tomoyo_fns(ptr->perm, bit);
962 		if (bit >= TOMOYO_MAX_PATH_NUMBER_OPERATION)
963 			goto done;
964 		tomoyo_io_printf(head, "allow_%s",
965 				 tomoyo_path_number_keyword[bit]);
966 		tomoyo_print_name_union(head, &ptr->name);
967 		tomoyo_print_number_union(head, &ptr->number);
968 	} else if (acl_type == TOMOYO_TYPE_MKDEV_ACL) {
969 		struct tomoyo_mkdev_acl *ptr =
970 			container_of(acl, typeof(*ptr), head);
971 		bit = tomoyo_fns(ptr->perm, bit);
972 		if (bit >= TOMOYO_MAX_MKDEV_OPERATION)
973 			goto done;
974 		tomoyo_io_printf(head, "allow_%s", tomoyo_mkdev_keyword[bit]);
975 		tomoyo_print_name_union(head, &ptr->name);
976 		tomoyo_print_number_union(head, &ptr->mode);
977 		tomoyo_print_number_union(head, &ptr->major);
978 		tomoyo_print_number_union(head, &ptr->minor);
979 	} else if (acl_type == TOMOYO_TYPE_MOUNT_ACL) {
980 		struct tomoyo_mount_acl *ptr =
981 			container_of(acl, typeof(*ptr), head);
982 		tomoyo_io_printf(head, "allow_mount");
983 		tomoyo_print_name_union(head, &ptr->dev_name);
984 		tomoyo_print_name_union(head, &ptr->dir_name);
985 		tomoyo_print_name_union(head, &ptr->fs_type);
986 		tomoyo_print_number_union(head, &ptr->flags);
987 	}
988 	head->r.bit = bit + 1;
989 	tomoyo_io_printf(head, "\n");
990 	if (acl_type != TOMOYO_TYPE_MOUNT_ACL)
991 		goto next;
992  done:
993 	head->r.bit = 0;
994 	return true;
995 }
996 
997 /**
998  * tomoyo_read_domain2 - Read domain policy.
999  *
1000  * @head:   Pointer to "struct tomoyo_io_buffer".
1001  * @domain: Pointer to "struct tomoyo_domain_info".
1002  *
1003  * Caller holds tomoyo_read_lock().
1004  *
1005  * Returns true on success, false otherwise.
1006  */
1007 static bool tomoyo_read_domain2(struct tomoyo_io_buffer *head,
1008 				struct tomoyo_domain_info *domain)
1009 {
1010 	list_for_each_cookie(head->r.acl, &domain->acl_info_list) {
1011 		struct tomoyo_acl_info *ptr =
1012 			list_entry(head->r.acl, typeof(*ptr), list);
1013 		if (!tomoyo_print_entry(head, ptr))
1014 			return false;
1015 	}
1016 	head->r.acl = NULL;
1017 	return true;
1018 }
1019 
1020 /**
1021  * tomoyo_read_domain - Read domain policy.
1022  *
1023  * @head: Pointer to "struct tomoyo_io_buffer".
1024  *
1025  * Caller holds tomoyo_read_lock().
1026  */
1027 static void tomoyo_read_domain(struct tomoyo_io_buffer *head)
1028 {
1029 	if (head->r.eof)
1030 		return;
1031 	list_for_each_cookie(head->r.domain, &tomoyo_domain_list) {
1032 		struct tomoyo_domain_info *domain =
1033 			list_entry(head->r.domain, typeof(*domain), list);
1034 		switch (head->r.step) {
1035 		case 0:
1036 			if (domain->is_deleted &&
1037 			    !head->r.print_this_domain_only)
1038 				continue;
1039 			/* Print domainname and flags. */
1040 			tomoyo_set_string(head, domain->domainname->name);
1041 			tomoyo_set_lf(head);
1042 			tomoyo_io_printf(head,
1043 					 TOMOYO_KEYWORD_USE_PROFILE "%u\n",
1044 					 domain->profile);
1045 			if (domain->quota_warned)
1046 				tomoyo_set_string(head, "quota_exceeded\n");
1047 			if (domain->transition_failed)
1048 				tomoyo_set_string(head, "transition_failed\n");
1049 			if (domain->ignore_global_allow_read)
1050 				tomoyo_set_string(head,
1051 				       TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ
1052 						  "\n");
1053 			head->r.step++;
1054 			tomoyo_set_lf(head);
1055 			/* fall through */
1056 		case 1:
1057 			if (!tomoyo_read_domain2(head, domain))
1058 				return;
1059 			head->r.step++;
1060 			if (!tomoyo_set_lf(head))
1061 				return;
1062 			/* fall through */
1063 		case 2:
1064 			head->r.step = 0;
1065 			if (head->r.print_this_domain_only)
1066 				goto done;
1067 		}
1068 	}
1069  done:
1070 	head->r.eof = true;
1071 }
1072 
1073 /**
1074  * tomoyo_write_domain_profile - Assign profile for specified domain.
1075  *
1076  * @head: Pointer to "struct tomoyo_io_buffer".
1077  *
1078  * Returns 0 on success, -EINVAL otherwise.
1079  *
1080  * This is equivalent to doing
1081  *
1082  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1083  *     /usr/sbin/tomoyo-loadpolicy -d
1084  *
1085  * Caller holds tomoyo_read_lock().
1086  */
1087 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1088 {
1089 	char *data = head->write_buf;
1090 	char *cp = strchr(data, ' ');
1091 	struct tomoyo_domain_info *domain;
1092 	unsigned long profile;
1093 
1094 	if (!cp)
1095 		return -EINVAL;
1096 	*cp = '\0';
1097 	domain = tomoyo_find_domain(cp + 1);
1098 	if (strict_strtoul(data, 10, &profile))
1099 		return -EINVAL;
1100 	if (domain && profile < TOMOYO_MAX_PROFILES
1101 	    && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1102 		domain->profile = (u8) profile;
1103 	return 0;
1104 }
1105 
1106 /**
1107  * tomoyo_read_domain_profile - Read only domainname and profile.
1108  *
1109  * @head: Pointer to "struct tomoyo_io_buffer".
1110  *
1111  * Returns list of profile number and domainname pairs.
1112  *
1113  * This is equivalent to doing
1114  *
1115  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1116  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1117  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1118  *     print $2 " " domainname; domainname = ""; } } ; '
1119  *
1120  * Caller holds tomoyo_read_lock().
1121  */
1122 static void tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1123 {
1124 	if (head->r.eof)
1125 		return;
1126 	list_for_each_cookie(head->r.domain, &tomoyo_domain_list) {
1127 		struct tomoyo_domain_info *domain =
1128 			list_entry(head->r.domain, typeof(*domain), list);
1129 		if (domain->is_deleted)
1130 			continue;
1131 		if (!tomoyo_flush(head))
1132 			return;
1133 		tomoyo_io_printf(head, "%u ", domain->profile);
1134 		tomoyo_set_string(head, domain->domainname->name);
1135 		tomoyo_set_lf(head);
1136 	}
1137 	head->r.eof = true;
1138 }
1139 
1140 /**
1141  * tomoyo_write_pid: Specify PID to obtain domainname.
1142  *
1143  * @head: Pointer to "struct tomoyo_io_buffer".
1144  *
1145  * Returns 0.
1146  */
1147 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1148 {
1149 	head->r.eof = false;
1150 	return 0;
1151 }
1152 
1153 /**
1154  * tomoyo_read_pid - Get domainname of the specified PID.
1155  *
1156  * @head: Pointer to "struct tomoyo_io_buffer".
1157  *
1158  * Returns the domainname which the specified PID is in on success,
1159  * empty string otherwise.
1160  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1161  * using read()/write() interface rather than sysctl() interface.
1162  */
1163 static void tomoyo_read_pid(struct tomoyo_io_buffer *head)
1164 {
1165 	char *buf = head->write_buf;
1166 	bool global_pid = false;
1167 	unsigned int pid;
1168 	struct task_struct *p;
1169 	struct tomoyo_domain_info *domain = NULL;
1170 
1171 	/* Accessing write_buf is safe because head->io_sem is held. */
1172 	if (!buf) {
1173 		head->r.eof = true;
1174 		return; /* Do nothing if open(O_RDONLY). */
1175 	}
1176 	if (head->r.w_pos || head->r.eof)
1177 		return;
1178 	head->r.eof = true;
1179 	if (tomoyo_str_starts(&buf, "global-pid "))
1180 		global_pid = true;
1181 	pid = (unsigned int) simple_strtoul(buf, NULL, 10);
1182 	rcu_read_lock();
1183 	read_lock(&tasklist_lock);
1184 	if (global_pid)
1185 		p = find_task_by_pid_ns(pid, &init_pid_ns);
1186 	else
1187 		p = find_task_by_vpid(pid);
1188 	if (p)
1189 		domain = tomoyo_real_domain(p);
1190 	read_unlock(&tasklist_lock);
1191 	rcu_read_unlock();
1192 	if (!domain)
1193 		return;
1194 	tomoyo_io_printf(head, "%u %u ", pid, domain->profile);
1195 	tomoyo_set_string(head, domain->domainname->name);
1196 }
1197 
1198 static const char *tomoyo_transition_type[TOMOYO_MAX_TRANSITION_TYPE] = {
1199 	[TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE]
1200 	= TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN,
1201 	[TOMOYO_TRANSITION_CONTROL_INITIALIZE]
1202 	= TOMOYO_KEYWORD_INITIALIZE_DOMAIN,
1203 	[TOMOYO_TRANSITION_CONTROL_NO_KEEP] = TOMOYO_KEYWORD_NO_KEEP_DOMAIN,
1204 	[TOMOYO_TRANSITION_CONTROL_KEEP] = TOMOYO_KEYWORD_KEEP_DOMAIN
1205 };
1206 
1207 static const char *tomoyo_group_name[TOMOYO_MAX_GROUP] = {
1208 	[TOMOYO_PATH_GROUP] = TOMOYO_KEYWORD_PATH_GROUP,
1209 	[TOMOYO_NUMBER_GROUP] = TOMOYO_KEYWORD_NUMBER_GROUP
1210 };
1211 
1212 /**
1213  * tomoyo_write_exception - Write exception policy.
1214  *
1215  * @head: Pointer to "struct tomoyo_io_buffer".
1216  *
1217  * Returns 0 on success, negative value otherwise.
1218  *
1219  * Caller holds tomoyo_read_lock().
1220  */
1221 static int tomoyo_write_exception(struct tomoyo_io_buffer *head)
1222 {
1223 	char *data = head->write_buf;
1224 	bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1225 	u8 i;
1226 	static const struct {
1227 		const char *keyword;
1228 		int (*write) (char *, const bool);
1229 	} tomoyo_callback[4] = {
1230 		{ TOMOYO_KEYWORD_AGGREGATOR, tomoyo_write_aggregator },
1231 		{ TOMOYO_KEYWORD_FILE_PATTERN, tomoyo_write_pattern },
1232 		{ TOMOYO_KEYWORD_DENY_REWRITE, tomoyo_write_no_rewrite },
1233 		{ TOMOYO_KEYWORD_ALLOW_READ, tomoyo_write_globally_readable },
1234 	};
1235 
1236 	for (i = 0; i < TOMOYO_MAX_TRANSITION_TYPE; i++)
1237 		if (tomoyo_str_starts(&data, tomoyo_transition_type[i]))
1238 			return tomoyo_write_transition_control(data, is_delete,
1239 							       i);
1240 	for (i = 0; i < 4; i++)
1241 		if (tomoyo_str_starts(&data, tomoyo_callback[i].keyword))
1242 			return tomoyo_callback[i].write(data, is_delete);
1243 	for (i = 0; i < TOMOYO_MAX_GROUP; i++)
1244 		if (tomoyo_str_starts(&data, tomoyo_group_name[i]))
1245 			return tomoyo_write_group(data, is_delete, i);
1246 	return -EINVAL;
1247 }
1248 
1249 /**
1250  * tomoyo_read_group - Read "struct tomoyo_path_group"/"struct tomoyo_number_group" list.
1251  *
1252  * @head: Pointer to "struct tomoyo_io_buffer".
1253  * @idx:  Index number.
1254  *
1255  * Returns true on success, false otherwise.
1256  *
1257  * Caller holds tomoyo_read_lock().
1258  */
1259 static bool tomoyo_read_group(struct tomoyo_io_buffer *head, const int idx)
1260 {
1261 	list_for_each_cookie(head->r.group, &tomoyo_group_list[idx]) {
1262 		struct tomoyo_group *group =
1263 			list_entry(head->r.group, typeof(*group), list);
1264 		list_for_each_cookie(head->r.acl, &group->member_list) {
1265 			struct tomoyo_acl_head *ptr =
1266 				list_entry(head->r.acl, typeof(*ptr), list);
1267 			if (ptr->is_deleted)
1268 				continue;
1269 			if (!tomoyo_flush(head))
1270 				return false;
1271 			tomoyo_set_string(head, tomoyo_group_name[idx]);
1272 			tomoyo_set_string(head, group->group_name->name);
1273 			if (idx == TOMOYO_PATH_GROUP) {
1274 				tomoyo_set_space(head);
1275 				tomoyo_set_string(head, container_of
1276 					       (ptr, struct tomoyo_path_group,
1277 						head)->member_name->name);
1278 			} else if (idx == TOMOYO_NUMBER_GROUP) {
1279 				tomoyo_print_number_union(head, &container_of
1280 							  (ptr,
1281 						   struct tomoyo_number_group,
1282 							   head)->number);
1283 			}
1284 			tomoyo_set_lf(head);
1285 		}
1286 		head->r.acl = NULL;
1287 	}
1288 	head->r.group = NULL;
1289 	return true;
1290 }
1291 
1292 /**
1293  * tomoyo_read_policy - Read "struct tomoyo_..._entry" list.
1294  *
1295  * @head: Pointer to "struct tomoyo_io_buffer".
1296  * @idx:  Index number.
1297  *
1298  * Returns true on success, false otherwise.
1299  *
1300  * Caller holds tomoyo_read_lock().
1301  */
1302 static bool tomoyo_read_policy(struct tomoyo_io_buffer *head, const int idx)
1303 {
1304 	list_for_each_cookie(head->r.acl, &tomoyo_policy_list[idx]) {
1305 		struct tomoyo_acl_head *acl =
1306 			container_of(head->r.acl, typeof(*acl), list);
1307 		if (acl->is_deleted)
1308 			continue;
1309 		if (!tomoyo_flush(head))
1310 			return false;
1311 		switch (idx) {
1312 		case TOMOYO_ID_TRANSITION_CONTROL:
1313 			{
1314 				struct tomoyo_transition_control *ptr =
1315 					container_of(acl, typeof(*ptr), head);
1316 				tomoyo_set_string(head,
1317 						  tomoyo_transition_type
1318 						  [ptr->type]);
1319 				if (ptr->program)
1320 					tomoyo_set_string(head,
1321 							  ptr->program->name);
1322 				if (ptr->program && ptr->domainname)
1323 					tomoyo_set_string(head, " from ");
1324 				if (ptr->domainname)
1325 					tomoyo_set_string(head,
1326 							  ptr->domainname->
1327 							  name);
1328 			}
1329 			break;
1330 		case TOMOYO_ID_GLOBALLY_READABLE:
1331 			{
1332 				struct tomoyo_readable_file *ptr =
1333 					container_of(acl, typeof(*ptr), head);
1334 				tomoyo_set_string(head,
1335 						  TOMOYO_KEYWORD_ALLOW_READ);
1336 				tomoyo_set_string(head, ptr->filename->name);
1337 			}
1338 			break;
1339 		case TOMOYO_ID_AGGREGATOR:
1340 			{
1341 				struct tomoyo_aggregator *ptr =
1342 					container_of(acl, typeof(*ptr), head);
1343 				tomoyo_set_string(head,
1344 						  TOMOYO_KEYWORD_AGGREGATOR);
1345 				tomoyo_set_string(head,
1346 						  ptr->original_name->name);
1347 				tomoyo_set_space(head);
1348 				tomoyo_set_string(head,
1349 					       ptr->aggregated_name->name);
1350 			}
1351 			break;
1352 		case TOMOYO_ID_PATTERN:
1353 			{
1354 				struct tomoyo_no_pattern *ptr =
1355 					container_of(acl, typeof(*ptr), head);
1356 				tomoyo_set_string(head,
1357 						  TOMOYO_KEYWORD_FILE_PATTERN);
1358 				tomoyo_set_string(head, ptr->pattern->name);
1359 			}
1360 			break;
1361 		case TOMOYO_ID_NO_REWRITE:
1362 			{
1363 				struct tomoyo_no_rewrite *ptr =
1364 					container_of(acl, typeof(*ptr), head);
1365 				tomoyo_set_string(head,
1366 						  TOMOYO_KEYWORD_DENY_REWRITE);
1367 				tomoyo_set_string(head, ptr->pattern->name);
1368 			}
1369 			break;
1370 		default:
1371 			continue;
1372 		}
1373 		tomoyo_set_lf(head);
1374 	}
1375 	head->r.acl = NULL;
1376 	return true;
1377 }
1378 
1379 /**
1380  * tomoyo_read_exception - Read exception policy.
1381  *
1382  * @head: Pointer to "struct tomoyo_io_buffer".
1383  *
1384  * Caller holds tomoyo_read_lock().
1385  */
1386 static void tomoyo_read_exception(struct tomoyo_io_buffer *head)
1387 {
1388 	if (head->r.eof)
1389 		return;
1390 	while (head->r.step < TOMOYO_MAX_POLICY &&
1391 	       tomoyo_read_policy(head, head->r.step))
1392 		head->r.step++;
1393 	if (head->r.step < TOMOYO_MAX_POLICY)
1394 		return;
1395 	while (head->r.step < TOMOYO_MAX_POLICY + TOMOYO_MAX_GROUP &&
1396 	       tomoyo_read_group(head, head->r.step - TOMOYO_MAX_POLICY))
1397 		head->r.step++;
1398 	if (head->r.step < TOMOYO_MAX_POLICY + TOMOYO_MAX_GROUP)
1399 		return;
1400 	head->r.eof = true;
1401 }
1402 
1403 /**
1404  * tomoyo_print_header - Get header line of audit log.
1405  *
1406  * @r: Pointer to "struct tomoyo_request_info".
1407  *
1408  * Returns string representation.
1409  *
1410  * This function uses kmalloc(), so caller must kfree() if this function
1411  * didn't return NULL.
1412  */
1413 static char *tomoyo_print_header(struct tomoyo_request_info *r)
1414 {
1415 	struct timeval tv;
1416 	const pid_t gpid = task_pid_nr(current);
1417 	static const int tomoyo_buffer_len = 4096;
1418 	char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
1419 	pid_t ppid;
1420 	if (!buffer)
1421 		return NULL;
1422 	do_gettimeofday(&tv);
1423 	rcu_read_lock();
1424 	ppid = task_tgid_vnr(current->real_parent);
1425 	rcu_read_unlock();
1426 	snprintf(buffer, tomoyo_buffer_len - 1,
1427 		 "#timestamp=%lu profile=%u mode=%s (global-pid=%u)"
1428 		 " task={ pid=%u ppid=%u uid=%u gid=%u euid=%u"
1429 		 " egid=%u suid=%u sgid=%u fsuid=%u fsgid=%u }",
1430 		 tv.tv_sec, r->profile, tomoyo_mode[r->mode], gpid,
1431 		 task_tgid_vnr(current), ppid,
1432 		 current_uid(), current_gid(), current_euid(),
1433 		 current_egid(), current_suid(), current_sgid(),
1434 		 current_fsuid(), current_fsgid());
1435 	return buffer;
1436 }
1437 
1438 /**
1439  * tomoyo_init_audit_log - Allocate buffer for audit logs.
1440  *
1441  * @len: Required size.
1442  * @r:   Pointer to "struct tomoyo_request_info".
1443  *
1444  * Returns pointer to allocated memory.
1445  *
1446  * The @len is updated to add the header lines' size on success.
1447  *
1448  * This function uses kzalloc(), so caller must kfree() if this function
1449  * didn't return NULL.
1450  */
1451 static char *tomoyo_init_audit_log(int *len, struct tomoyo_request_info *r)
1452 {
1453 	char *buf = NULL;
1454 	const char *header;
1455 	const char *domainname;
1456 	if (!r->domain)
1457 		r->domain = tomoyo_domain();
1458 	domainname = r->domain->domainname->name;
1459 	header = tomoyo_print_header(r);
1460 	if (!header)
1461 		return NULL;
1462 	*len += strlen(domainname) + strlen(header) + 10;
1463 	buf = kzalloc(*len, GFP_NOFS);
1464 	if (buf)
1465 		snprintf(buf, (*len) - 1, "%s\n%s\n", header, domainname);
1466 	kfree(header);
1467 	return buf;
1468 }
1469 
1470 /* Wait queue for tomoyo_query_list. */
1471 static DECLARE_WAIT_QUEUE_HEAD(tomoyo_query_wait);
1472 
1473 /* Lock for manipulating tomoyo_query_list. */
1474 static DEFINE_SPINLOCK(tomoyo_query_list_lock);
1475 
1476 /* Structure for query. */
1477 struct tomoyo_query {
1478 	struct list_head list;
1479 	char *query;
1480 	int query_len;
1481 	unsigned int serial;
1482 	int timer;
1483 	int answer;
1484 };
1485 
1486 /* The list for "struct tomoyo_query". */
1487 static LIST_HEAD(tomoyo_query_list);
1488 
1489 /*
1490  * Number of "struct file" referring /sys/kernel/security/tomoyo/query
1491  * interface.
1492  */
1493 static atomic_t tomoyo_query_observers = ATOMIC_INIT(0);
1494 
1495 /**
1496  * tomoyo_supervisor - Ask for the supervisor's decision.
1497  *
1498  * @r:       Pointer to "struct tomoyo_request_info".
1499  * @fmt:     The printf()'s format string, followed by parameters.
1500  *
1501  * Returns 0 if the supervisor decided to permit the access request which
1502  * violated the policy in enforcing mode, TOMOYO_RETRY_REQUEST if the
1503  * supervisor decided to retry the access request which violated the policy in
1504  * enforcing mode, 0 if it is not in enforcing mode, -EPERM otherwise.
1505  */
1506 int tomoyo_supervisor(struct tomoyo_request_info *r, const char *fmt, ...)
1507 {
1508 	va_list args;
1509 	int error = -EPERM;
1510 	int pos;
1511 	int len;
1512 	static unsigned int tomoyo_serial;
1513 	struct tomoyo_query *entry = NULL;
1514 	bool quota_exceeded = false;
1515 	char *header;
1516 	switch (r->mode) {
1517 		char *buffer;
1518 	case TOMOYO_CONFIG_LEARNING:
1519 		if (!tomoyo_domain_quota_is_ok(r))
1520 			return 0;
1521 		va_start(args, fmt);
1522 		len = vsnprintf((char *) &pos, sizeof(pos) - 1, fmt, args) + 4;
1523 		va_end(args);
1524 		buffer = kmalloc(len, GFP_NOFS);
1525 		if (!buffer)
1526 			return 0;
1527 		va_start(args, fmt);
1528 		vsnprintf(buffer, len - 1, fmt, args);
1529 		va_end(args);
1530 		tomoyo_normalize_line(buffer);
1531 		tomoyo_write_domain2(buffer, r->domain, false);
1532 		kfree(buffer);
1533 		/* fall through */
1534 	case TOMOYO_CONFIG_PERMISSIVE:
1535 		return 0;
1536 	}
1537 	if (!r->domain)
1538 		r->domain = tomoyo_domain();
1539 	if (!atomic_read(&tomoyo_query_observers))
1540 		return -EPERM;
1541 	va_start(args, fmt);
1542 	len = vsnprintf((char *) &pos, sizeof(pos) - 1, fmt, args) + 32;
1543 	va_end(args);
1544 	header = tomoyo_init_audit_log(&len, r);
1545 	if (!header)
1546 		goto out;
1547 	entry = kzalloc(sizeof(*entry), GFP_NOFS);
1548 	if (!entry)
1549 		goto out;
1550 	entry->query = kzalloc(len, GFP_NOFS);
1551 	if (!entry->query)
1552 		goto out;
1553 	len = ksize(entry->query);
1554 	spin_lock(&tomoyo_query_list_lock);
1555 	if (tomoyo_quota_for_query && tomoyo_query_memory_size + len +
1556 	    sizeof(*entry) >= tomoyo_quota_for_query) {
1557 		quota_exceeded = true;
1558 	} else {
1559 		tomoyo_query_memory_size += len + sizeof(*entry);
1560 		entry->serial = tomoyo_serial++;
1561 	}
1562 	spin_unlock(&tomoyo_query_list_lock);
1563 	if (quota_exceeded)
1564 		goto out;
1565 	pos = snprintf(entry->query, len - 1, "Q%u-%hu\n%s",
1566 		       entry->serial, r->retry, header);
1567 	kfree(header);
1568 	header = NULL;
1569 	va_start(args, fmt);
1570 	vsnprintf(entry->query + pos, len - 1 - pos, fmt, args);
1571 	entry->query_len = strlen(entry->query) + 1;
1572 	va_end(args);
1573 	spin_lock(&tomoyo_query_list_lock);
1574 	list_add_tail(&entry->list, &tomoyo_query_list);
1575 	spin_unlock(&tomoyo_query_list_lock);
1576 	/* Give 10 seconds for supervisor's opinion. */
1577 	for (entry->timer = 0;
1578 	     atomic_read(&tomoyo_query_observers) && entry->timer < 100;
1579 	     entry->timer++) {
1580 		wake_up(&tomoyo_query_wait);
1581 		set_current_state(TASK_INTERRUPTIBLE);
1582 		schedule_timeout(HZ / 10);
1583 		if (entry->answer)
1584 			break;
1585 	}
1586 	spin_lock(&tomoyo_query_list_lock);
1587 	list_del(&entry->list);
1588 	tomoyo_query_memory_size -= len + sizeof(*entry);
1589 	spin_unlock(&tomoyo_query_list_lock);
1590 	switch (entry->answer) {
1591 	case 3: /* Asked to retry by administrator. */
1592 		error = TOMOYO_RETRY_REQUEST;
1593 		r->retry++;
1594 		break;
1595 	case 1:
1596 		/* Granted by administrator. */
1597 		error = 0;
1598 		break;
1599 	case 0:
1600 		/* Timed out. */
1601 		break;
1602 	default:
1603 		/* Rejected by administrator. */
1604 		break;
1605 	}
1606  out:
1607 	if (entry)
1608 		kfree(entry->query);
1609 	kfree(entry);
1610 	kfree(header);
1611 	return error;
1612 }
1613 
1614 /**
1615  * tomoyo_poll_query - poll() for /sys/kernel/security/tomoyo/query.
1616  *
1617  * @file: Pointer to "struct file".
1618  * @wait: Pointer to "poll_table".
1619  *
1620  * Returns POLLIN | POLLRDNORM when ready to read, 0 otherwise.
1621  *
1622  * Waits for access requests which violated policy in enforcing mode.
1623  */
1624 static int tomoyo_poll_query(struct file *file, poll_table *wait)
1625 {
1626 	struct list_head *tmp;
1627 	bool found = false;
1628 	u8 i;
1629 	for (i = 0; i < 2; i++) {
1630 		spin_lock(&tomoyo_query_list_lock);
1631 		list_for_each(tmp, &tomoyo_query_list) {
1632 			struct tomoyo_query *ptr =
1633 				list_entry(tmp, typeof(*ptr), list);
1634 			if (ptr->answer)
1635 				continue;
1636 			found = true;
1637 			break;
1638 		}
1639 		spin_unlock(&tomoyo_query_list_lock);
1640 		if (found)
1641 			return POLLIN | POLLRDNORM;
1642 		if (i)
1643 			break;
1644 		poll_wait(file, &tomoyo_query_wait, wait);
1645 	}
1646 	return 0;
1647 }
1648 
1649 /**
1650  * tomoyo_read_query - Read access requests which violated policy in enforcing mode.
1651  *
1652  * @head: Pointer to "struct tomoyo_io_buffer".
1653  */
1654 static void tomoyo_read_query(struct tomoyo_io_buffer *head)
1655 {
1656 	struct list_head *tmp;
1657 	int pos = 0;
1658 	int len = 0;
1659 	char *buf;
1660 	if (head->r.w_pos)
1661 		return;
1662 	if (head->read_buf) {
1663 		kfree(head->read_buf);
1664 		head->read_buf = NULL;
1665 	}
1666 	spin_lock(&tomoyo_query_list_lock);
1667 	list_for_each(tmp, &tomoyo_query_list) {
1668 		struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
1669 		if (ptr->answer)
1670 			continue;
1671 		if (pos++ != head->r.query_index)
1672 			continue;
1673 		len = ptr->query_len;
1674 		break;
1675 	}
1676 	spin_unlock(&tomoyo_query_list_lock);
1677 	if (!len) {
1678 		head->r.query_index = 0;
1679 		return;
1680 	}
1681 	buf = kzalloc(len, GFP_NOFS);
1682 	if (!buf)
1683 		return;
1684 	pos = 0;
1685 	spin_lock(&tomoyo_query_list_lock);
1686 	list_for_each(tmp, &tomoyo_query_list) {
1687 		struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
1688 		if (ptr->answer)
1689 			continue;
1690 		if (pos++ != head->r.query_index)
1691 			continue;
1692 		/*
1693 		 * Some query can be skipped because tomoyo_query_list
1694 		 * can change, but I don't care.
1695 		 */
1696 		if (len == ptr->query_len)
1697 			memmove(buf, ptr->query, len);
1698 		break;
1699 	}
1700 	spin_unlock(&tomoyo_query_list_lock);
1701 	if (buf[0]) {
1702 		head->read_buf = buf;
1703 		head->r.w[head->r.w_pos++] = buf;
1704 		head->r.query_index++;
1705 	} else {
1706 		kfree(buf);
1707 	}
1708 }
1709 
1710 /**
1711  * tomoyo_write_answer - Write the supervisor's decision.
1712  *
1713  * @head: Pointer to "struct tomoyo_io_buffer".
1714  *
1715  * Returns 0 on success, -EINVAL otherwise.
1716  */
1717 static int tomoyo_write_answer(struct tomoyo_io_buffer *head)
1718 {
1719 	char *data = head->write_buf;
1720 	struct list_head *tmp;
1721 	unsigned int serial;
1722 	unsigned int answer;
1723 	spin_lock(&tomoyo_query_list_lock);
1724 	list_for_each(tmp, &tomoyo_query_list) {
1725 		struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
1726 		ptr->timer = 0;
1727 	}
1728 	spin_unlock(&tomoyo_query_list_lock);
1729 	if (sscanf(data, "A%u=%u", &serial, &answer) != 2)
1730 		return -EINVAL;
1731 	spin_lock(&tomoyo_query_list_lock);
1732 	list_for_each(tmp, &tomoyo_query_list) {
1733 		struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
1734 		if (ptr->serial != serial)
1735 			continue;
1736 		if (!ptr->answer)
1737 			ptr->answer = answer;
1738 		break;
1739 	}
1740 	spin_unlock(&tomoyo_query_list_lock);
1741 	return 0;
1742 }
1743 
1744 /**
1745  * tomoyo_read_version: Get version.
1746  *
1747  * @head: Pointer to "struct tomoyo_io_buffer".
1748  *
1749  * Returns version information.
1750  */
1751 static void tomoyo_read_version(struct tomoyo_io_buffer *head)
1752 {
1753 	if (!head->r.eof) {
1754 		tomoyo_io_printf(head, "2.3.0");
1755 		head->r.eof = true;
1756 	}
1757 }
1758 
1759 /**
1760  * tomoyo_read_self_domain - Get the current process's domainname.
1761  *
1762  * @head: Pointer to "struct tomoyo_io_buffer".
1763  *
1764  * Returns the current process's domainname.
1765  */
1766 static void tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1767 {
1768 	if (!head->r.eof) {
1769 		/*
1770 		 * tomoyo_domain()->domainname != NULL
1771 		 * because every process belongs to a domain and
1772 		 * the domain's name cannot be NULL.
1773 		 */
1774 		tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1775 		head->r.eof = true;
1776 	}
1777 }
1778 
1779 /**
1780  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1781  *
1782  * @type: Type of interface.
1783  * @file: Pointer to "struct file".
1784  *
1785  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1786  *
1787  * Caller acquires tomoyo_read_lock().
1788  */
1789 int tomoyo_open_control(const u8 type, struct file *file)
1790 {
1791 	struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_NOFS);
1792 
1793 	if (!head)
1794 		return -ENOMEM;
1795 	mutex_init(&head->io_sem);
1796 	head->type = type;
1797 	switch (type) {
1798 	case TOMOYO_DOMAINPOLICY:
1799 		/* /sys/kernel/security/tomoyo/domain_policy */
1800 		head->write = tomoyo_write_domain;
1801 		head->read = tomoyo_read_domain;
1802 		break;
1803 	case TOMOYO_EXCEPTIONPOLICY:
1804 		/* /sys/kernel/security/tomoyo/exception_policy */
1805 		head->write = tomoyo_write_exception;
1806 		head->read = tomoyo_read_exception;
1807 		break;
1808 	case TOMOYO_SELFDOMAIN:
1809 		/* /sys/kernel/security/tomoyo/self_domain */
1810 		head->read = tomoyo_read_self_domain;
1811 		break;
1812 	case TOMOYO_DOMAIN_STATUS:
1813 		/* /sys/kernel/security/tomoyo/.domain_status */
1814 		head->write = tomoyo_write_domain_profile;
1815 		head->read = tomoyo_read_domain_profile;
1816 		break;
1817 	case TOMOYO_PROCESS_STATUS:
1818 		/* /sys/kernel/security/tomoyo/.process_status */
1819 		head->write = tomoyo_write_pid;
1820 		head->read = tomoyo_read_pid;
1821 		break;
1822 	case TOMOYO_VERSION:
1823 		/* /sys/kernel/security/tomoyo/version */
1824 		head->read = tomoyo_read_version;
1825 		head->readbuf_size = 128;
1826 		break;
1827 	case TOMOYO_MEMINFO:
1828 		/* /sys/kernel/security/tomoyo/meminfo */
1829 		head->write = tomoyo_write_memory_quota;
1830 		head->read = tomoyo_read_memory_counter;
1831 		head->readbuf_size = 512;
1832 		break;
1833 	case TOMOYO_PROFILE:
1834 		/* /sys/kernel/security/tomoyo/profile */
1835 		head->write = tomoyo_write_profile;
1836 		head->read = tomoyo_read_profile;
1837 		break;
1838 	case TOMOYO_QUERY: /* /sys/kernel/security/tomoyo/query */
1839 		head->poll = tomoyo_poll_query;
1840 		head->write = tomoyo_write_answer;
1841 		head->read = tomoyo_read_query;
1842 		break;
1843 	case TOMOYO_MANAGER:
1844 		/* /sys/kernel/security/tomoyo/manager */
1845 		head->write = tomoyo_write_manager;
1846 		head->read = tomoyo_read_manager;
1847 		break;
1848 	}
1849 	if (!(file->f_mode & FMODE_READ)) {
1850 		/*
1851 		 * No need to allocate read_buf since it is not opened
1852 		 * for reading.
1853 		 */
1854 		head->read = NULL;
1855 		head->poll = NULL;
1856 	} else if (!head->poll) {
1857 		/* Don't allocate read_buf for poll() access. */
1858 		if (!head->readbuf_size)
1859 			head->readbuf_size = 4096 * 2;
1860 		head->read_buf = kzalloc(head->readbuf_size, GFP_NOFS);
1861 		if (!head->read_buf) {
1862 			kfree(head);
1863 			return -ENOMEM;
1864 		}
1865 	}
1866 	if (!(file->f_mode & FMODE_WRITE)) {
1867 		/*
1868 		 * No need to allocate write_buf since it is not opened
1869 		 * for writing.
1870 		 */
1871 		head->write = NULL;
1872 	} else if (head->write) {
1873 		head->writebuf_size = 4096 * 2;
1874 		head->write_buf = kzalloc(head->writebuf_size, GFP_NOFS);
1875 		if (!head->write_buf) {
1876 			kfree(head->read_buf);
1877 			kfree(head);
1878 			return -ENOMEM;
1879 		}
1880 	}
1881 	if (type != TOMOYO_QUERY)
1882 		head->reader_idx = tomoyo_read_lock();
1883 	file->private_data = head;
1884 	/*
1885 	 * Call the handler now if the file is
1886 	 * /sys/kernel/security/tomoyo/self_domain
1887 	 * so that the user can use
1888 	 * cat < /sys/kernel/security/tomoyo/self_domain"
1889 	 * to know the current process's domainname.
1890 	 */
1891 	if (type == TOMOYO_SELFDOMAIN)
1892 		tomoyo_read_control(file, NULL, 0);
1893 	/*
1894 	 * If the file is /sys/kernel/security/tomoyo/query , increment the
1895 	 * observer counter.
1896 	 * The obserber counter is used by tomoyo_supervisor() to see if
1897 	 * there is some process monitoring /sys/kernel/security/tomoyo/query.
1898 	 */
1899 	else if (type == TOMOYO_QUERY)
1900 		atomic_inc(&tomoyo_query_observers);
1901 	return 0;
1902 }
1903 
1904 /**
1905  * tomoyo_poll_control - poll() for /sys/kernel/security/tomoyo/ interface.
1906  *
1907  * @file: Pointer to "struct file".
1908  * @wait: Pointer to "poll_table".
1909  *
1910  * Waits for read readiness.
1911  * /sys/kernel/security/tomoyo/query is handled by /usr/sbin/tomoyo-queryd .
1912  */
1913 int tomoyo_poll_control(struct file *file, poll_table *wait)
1914 {
1915 	struct tomoyo_io_buffer *head = file->private_data;
1916 	if (!head->poll)
1917 		return -ENOSYS;
1918 	return head->poll(file, wait);
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  * Caller holds tomoyo_read_lock().
1931  */
1932 int tomoyo_read_control(struct file *file, char __user *buffer,
1933 			const int buffer_len)
1934 {
1935 	int len;
1936 	struct tomoyo_io_buffer *head = file->private_data;
1937 
1938 	if (!head->read)
1939 		return -ENOSYS;
1940 	if (mutex_lock_interruptible(&head->io_sem))
1941 		return -EINTR;
1942 	head->read_user_buf = buffer;
1943 	head->read_user_buf_avail = buffer_len;
1944 	if (tomoyo_flush(head))
1945 		/* Call the policy handler. */
1946 		head->read(head);
1947 	tomoyo_flush(head);
1948 	len = head->read_user_buf - buffer;
1949 	mutex_unlock(&head->io_sem);
1950 	return len;
1951 }
1952 
1953 /**
1954  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
1955  *
1956  * @file:       Pointer to "struct file".
1957  * @buffer:     Pointer to buffer to read from.
1958  * @buffer_len: Size of @buffer.
1959  *
1960  * Returns @buffer_len on success, negative value otherwise.
1961  *
1962  * Caller holds tomoyo_read_lock().
1963  */
1964 int tomoyo_write_control(struct file *file, const char __user *buffer,
1965 			 const int buffer_len)
1966 {
1967 	struct tomoyo_io_buffer *head = file->private_data;
1968 	int error = buffer_len;
1969 	int avail_len = buffer_len;
1970 	char *cp0 = head->write_buf;
1971 
1972 	if (!head->write)
1973 		return -ENOSYS;
1974 	if (!access_ok(VERIFY_READ, buffer, buffer_len))
1975 		return -EFAULT;
1976 	/* Don't allow updating policies by non manager programs. */
1977 	if (head->write != tomoyo_write_pid &&
1978 	    head->write != tomoyo_write_domain && !tomoyo_manager())
1979 		return -EPERM;
1980 	if (mutex_lock_interruptible(&head->io_sem))
1981 		return -EINTR;
1982 	/* Read a line and dispatch it to the policy handler. */
1983 	while (avail_len > 0) {
1984 		char c;
1985 		if (head->write_avail >= head->writebuf_size - 1) {
1986 			error = -ENOMEM;
1987 			break;
1988 		} else if (get_user(c, buffer)) {
1989 			error = -EFAULT;
1990 			break;
1991 		}
1992 		buffer++;
1993 		avail_len--;
1994 		cp0[head->write_avail++] = c;
1995 		if (c != '\n')
1996 			continue;
1997 		cp0[head->write_avail - 1] = '\0';
1998 		head->write_avail = 0;
1999 		tomoyo_normalize_line(cp0);
2000 		head->write(head);
2001 	}
2002 	mutex_unlock(&head->io_sem);
2003 	return error;
2004 }
2005 
2006 /**
2007  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2008  *
2009  * @file: Pointer to "struct file".
2010  *
2011  * Releases memory and returns 0.
2012  *
2013  * Caller looses tomoyo_read_lock().
2014  */
2015 int tomoyo_close_control(struct file *file)
2016 {
2017 	struct tomoyo_io_buffer *head = file->private_data;
2018 	const bool is_write = !!head->write_buf;
2019 
2020 	/*
2021 	 * If the file is /sys/kernel/security/tomoyo/query , decrement the
2022 	 * observer counter.
2023 	 */
2024 	if (head->type == TOMOYO_QUERY)
2025 		atomic_dec(&tomoyo_query_observers);
2026 	else
2027 		tomoyo_read_unlock(head->reader_idx);
2028 	/* Release memory used for policy I/O. */
2029 	kfree(head->read_buf);
2030 	head->read_buf = NULL;
2031 	kfree(head->write_buf);
2032 	head->write_buf = NULL;
2033 	kfree(head);
2034 	head = NULL;
2035 	file->private_data = NULL;
2036 	if (is_write)
2037 		tomoyo_run_gc();
2038 	return 0;
2039 }
2040 
2041 /**
2042  * tomoyo_check_profile - Check all profiles currently assigned to domains are defined.
2043  */
2044 void tomoyo_check_profile(void)
2045 {
2046 	struct tomoyo_domain_info *domain;
2047 	const int idx = tomoyo_read_lock();
2048 	tomoyo_policy_loaded = true;
2049 	/* Check all profiles currently assigned to domains are defined. */
2050 	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
2051 		const u8 profile = domain->profile;
2052 		if (tomoyo_profile_ptr[profile])
2053 			continue;
2054 		panic("Profile %u (used by '%s') not defined.\n",
2055 		      profile, domain->domainname->name);
2056 	}
2057 	tomoyo_read_unlock(idx);
2058 	if (tomoyo_profile_version != 20090903)
2059 		panic("Profile version %u is not supported.\n",
2060 		      tomoyo_profile_version);
2061 	printk(KERN_INFO "TOMOYO: 2.3.0\n");
2062 	printk(KERN_INFO "Mandatory Access Control activated.\n");
2063 }
2064