xref: /linux/security/tomoyo/common.c (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * security/tomoyo/common.c
4  *
5  * Copyright (C) 2005-2011  NTT DATA CORPORATION
6  */
7 
8 #include <linux/uaccess.h>
9 #include <linux/slab.h>
10 #include <linux/security.h>
11 #include <linux/string_helpers.h>
12 #include "common.h"
13 
14 /* String table for operation mode. */
15 const char * const tomoyo_mode[TOMOYO_CONFIG_MAX_MODE] = {
16 	[TOMOYO_CONFIG_DISABLED]   = "disabled",
17 	[TOMOYO_CONFIG_LEARNING]   = "learning",
18 	[TOMOYO_CONFIG_PERMISSIVE] = "permissive",
19 	[TOMOYO_CONFIG_ENFORCING]  = "enforcing"
20 };
21 
22 /* String table for /sys/kernel/security/tomoyo/profile */
23 const char * const tomoyo_mac_keywords[TOMOYO_MAX_MAC_INDEX
24 				       + TOMOYO_MAX_MAC_CATEGORY_INDEX] = {
25 	/* CONFIG::file group */
26 	[TOMOYO_MAC_FILE_EXECUTE]    = "execute",
27 	[TOMOYO_MAC_FILE_OPEN]       = "open",
28 	[TOMOYO_MAC_FILE_CREATE]     = "create",
29 	[TOMOYO_MAC_FILE_UNLINK]     = "unlink",
30 	[TOMOYO_MAC_FILE_GETATTR]    = "getattr",
31 	[TOMOYO_MAC_FILE_MKDIR]      = "mkdir",
32 	[TOMOYO_MAC_FILE_RMDIR]      = "rmdir",
33 	[TOMOYO_MAC_FILE_MKFIFO]     = "mkfifo",
34 	[TOMOYO_MAC_FILE_MKSOCK]     = "mksock",
35 	[TOMOYO_MAC_FILE_TRUNCATE]   = "truncate",
36 	[TOMOYO_MAC_FILE_SYMLINK]    = "symlink",
37 	[TOMOYO_MAC_FILE_MKBLOCK]    = "mkblock",
38 	[TOMOYO_MAC_FILE_MKCHAR]     = "mkchar",
39 	[TOMOYO_MAC_FILE_LINK]       = "link",
40 	[TOMOYO_MAC_FILE_RENAME]     = "rename",
41 	[TOMOYO_MAC_FILE_CHMOD]      = "chmod",
42 	[TOMOYO_MAC_FILE_CHOWN]      = "chown",
43 	[TOMOYO_MAC_FILE_CHGRP]      = "chgrp",
44 	[TOMOYO_MAC_FILE_IOCTL]      = "ioctl",
45 	[TOMOYO_MAC_FILE_CHROOT]     = "chroot",
46 	[TOMOYO_MAC_FILE_MOUNT]      = "mount",
47 	[TOMOYO_MAC_FILE_UMOUNT]     = "unmount",
48 	[TOMOYO_MAC_FILE_PIVOT_ROOT] = "pivot_root",
49 	/* CONFIG::network group */
50 	[TOMOYO_MAC_NETWORK_INET_STREAM_BIND]       = "inet_stream_bind",
51 	[TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN]     = "inet_stream_listen",
52 	[TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT]    = "inet_stream_connect",
53 	[TOMOYO_MAC_NETWORK_INET_DGRAM_BIND]        = "inet_dgram_bind",
54 	[TOMOYO_MAC_NETWORK_INET_DGRAM_SEND]        = "inet_dgram_send",
55 	[TOMOYO_MAC_NETWORK_INET_RAW_BIND]          = "inet_raw_bind",
56 	[TOMOYO_MAC_NETWORK_INET_RAW_SEND]          = "inet_raw_send",
57 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND]       = "unix_stream_bind",
58 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN]     = "unix_stream_listen",
59 	[TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT]    = "unix_stream_connect",
60 	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND]        = "unix_dgram_bind",
61 	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND]        = "unix_dgram_send",
62 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND]    = "unix_seqpacket_bind",
63 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN]  = "unix_seqpacket_listen",
64 	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT] = "unix_seqpacket_connect",
65 	/* CONFIG::misc group */
66 	[TOMOYO_MAC_ENVIRON] = "env",
67 	/* CONFIG group */
68 	[TOMOYO_MAX_MAC_INDEX + TOMOYO_MAC_CATEGORY_FILE] = "file",
69 	[TOMOYO_MAX_MAC_INDEX + TOMOYO_MAC_CATEGORY_NETWORK] = "network",
70 	[TOMOYO_MAX_MAC_INDEX + TOMOYO_MAC_CATEGORY_MISC] = "misc",
71 };
72 
73 /* String table for conditions. */
74 const char * const tomoyo_condition_keyword[TOMOYO_MAX_CONDITION_KEYWORD] = {
75 	[TOMOYO_TASK_UID]             = "task.uid",
76 	[TOMOYO_TASK_EUID]            = "task.euid",
77 	[TOMOYO_TASK_SUID]            = "task.suid",
78 	[TOMOYO_TASK_FSUID]           = "task.fsuid",
79 	[TOMOYO_TASK_GID]             = "task.gid",
80 	[TOMOYO_TASK_EGID]            = "task.egid",
81 	[TOMOYO_TASK_SGID]            = "task.sgid",
82 	[TOMOYO_TASK_FSGID]           = "task.fsgid",
83 	[TOMOYO_TASK_PID]             = "task.pid",
84 	[TOMOYO_TASK_PPID]            = "task.ppid",
85 	[TOMOYO_EXEC_ARGC]            = "exec.argc",
86 	[TOMOYO_EXEC_ENVC]            = "exec.envc",
87 	[TOMOYO_TYPE_IS_SOCKET]       = "socket",
88 	[TOMOYO_TYPE_IS_SYMLINK]      = "symlink",
89 	[TOMOYO_TYPE_IS_FILE]         = "file",
90 	[TOMOYO_TYPE_IS_BLOCK_DEV]    = "block",
91 	[TOMOYO_TYPE_IS_DIRECTORY]    = "directory",
92 	[TOMOYO_TYPE_IS_CHAR_DEV]     = "char",
93 	[TOMOYO_TYPE_IS_FIFO]         = "fifo",
94 	[TOMOYO_MODE_SETUID]          = "setuid",
95 	[TOMOYO_MODE_SETGID]          = "setgid",
96 	[TOMOYO_MODE_STICKY]          = "sticky",
97 	[TOMOYO_MODE_OWNER_READ]      = "owner_read",
98 	[TOMOYO_MODE_OWNER_WRITE]     = "owner_write",
99 	[TOMOYO_MODE_OWNER_EXECUTE]   = "owner_execute",
100 	[TOMOYO_MODE_GROUP_READ]      = "group_read",
101 	[TOMOYO_MODE_GROUP_WRITE]     = "group_write",
102 	[TOMOYO_MODE_GROUP_EXECUTE]   = "group_execute",
103 	[TOMOYO_MODE_OTHERS_READ]     = "others_read",
104 	[TOMOYO_MODE_OTHERS_WRITE]    = "others_write",
105 	[TOMOYO_MODE_OTHERS_EXECUTE]  = "others_execute",
106 	[TOMOYO_EXEC_REALPATH]        = "exec.realpath",
107 	[TOMOYO_SYMLINK_TARGET]       = "symlink.target",
108 	[TOMOYO_PATH1_UID]            = "path1.uid",
109 	[TOMOYO_PATH1_GID]            = "path1.gid",
110 	[TOMOYO_PATH1_INO]            = "path1.ino",
111 	[TOMOYO_PATH1_MAJOR]          = "path1.major",
112 	[TOMOYO_PATH1_MINOR]          = "path1.minor",
113 	[TOMOYO_PATH1_PERM]           = "path1.perm",
114 	[TOMOYO_PATH1_TYPE]           = "path1.type",
115 	[TOMOYO_PATH1_DEV_MAJOR]      = "path1.dev_major",
116 	[TOMOYO_PATH1_DEV_MINOR]      = "path1.dev_minor",
117 	[TOMOYO_PATH2_UID]            = "path2.uid",
118 	[TOMOYO_PATH2_GID]            = "path2.gid",
119 	[TOMOYO_PATH2_INO]            = "path2.ino",
120 	[TOMOYO_PATH2_MAJOR]          = "path2.major",
121 	[TOMOYO_PATH2_MINOR]          = "path2.minor",
122 	[TOMOYO_PATH2_PERM]           = "path2.perm",
123 	[TOMOYO_PATH2_TYPE]           = "path2.type",
124 	[TOMOYO_PATH2_DEV_MAJOR]      = "path2.dev_major",
125 	[TOMOYO_PATH2_DEV_MINOR]      = "path2.dev_minor",
126 	[TOMOYO_PATH1_PARENT_UID]     = "path1.parent.uid",
127 	[TOMOYO_PATH1_PARENT_GID]     = "path1.parent.gid",
128 	[TOMOYO_PATH1_PARENT_INO]     = "path1.parent.ino",
129 	[TOMOYO_PATH1_PARENT_PERM]    = "path1.parent.perm",
130 	[TOMOYO_PATH2_PARENT_UID]     = "path2.parent.uid",
131 	[TOMOYO_PATH2_PARENT_GID]     = "path2.parent.gid",
132 	[TOMOYO_PATH2_PARENT_INO]     = "path2.parent.ino",
133 	[TOMOYO_PATH2_PARENT_PERM]    = "path2.parent.perm",
134 };
135 
136 /* String table for PREFERENCE keyword. */
137 static const char * const tomoyo_pref_keywords[TOMOYO_MAX_PREF] = {
138 	[TOMOYO_PREF_MAX_AUDIT_LOG]      = "max_audit_log",
139 	[TOMOYO_PREF_MAX_LEARNING_ENTRY] = "max_learning_entry",
140 };
141 
142 /* String table for path operation. */
143 const char * const tomoyo_path_keyword[TOMOYO_MAX_PATH_OPERATION] = {
144 	[TOMOYO_TYPE_EXECUTE]    = "execute",
145 	[TOMOYO_TYPE_READ]       = "read",
146 	[TOMOYO_TYPE_WRITE]      = "write",
147 	[TOMOYO_TYPE_APPEND]     = "append",
148 	[TOMOYO_TYPE_UNLINK]     = "unlink",
149 	[TOMOYO_TYPE_GETATTR]    = "getattr",
150 	[TOMOYO_TYPE_RMDIR]      = "rmdir",
151 	[TOMOYO_TYPE_TRUNCATE]   = "truncate",
152 	[TOMOYO_TYPE_SYMLINK]    = "symlink",
153 	[TOMOYO_TYPE_CHROOT]     = "chroot",
154 	[TOMOYO_TYPE_UMOUNT]     = "unmount",
155 };
156 
157 /* String table for socket's operation. */
158 const char * const tomoyo_socket_keyword[TOMOYO_MAX_NETWORK_OPERATION] = {
159 	[TOMOYO_NETWORK_BIND]    = "bind",
160 	[TOMOYO_NETWORK_LISTEN]  = "listen",
161 	[TOMOYO_NETWORK_CONNECT] = "connect",
162 	[TOMOYO_NETWORK_SEND]    = "send",
163 };
164 
165 /* String table for categories. */
166 static const char * const tomoyo_category_keywords
167 [TOMOYO_MAX_MAC_CATEGORY_INDEX] = {
168 	[TOMOYO_MAC_CATEGORY_FILE]    = "file",
169 	[TOMOYO_MAC_CATEGORY_NETWORK] = "network",
170 	[TOMOYO_MAC_CATEGORY_MISC]    = "misc",
171 };
172 
173 /* Permit policy management by non-root user? */
174 static bool tomoyo_manage_by_non_root;
175 
176 /* Utility functions. */
177 
178 /**
179  * tomoyo_addprintf - strncat()-like-snprintf().
180  *
181  * @buffer: Buffer to write to. Must be '\0'-terminated.
182  * @len:    Size of @buffer.
183  * @fmt:    The printf()'s format string, followed by parameters.
184  *
185  * Returns nothing.
186  */
187 __printf(3, 4)
188 static void tomoyo_addprintf(char *buffer, int len, const char *fmt, ...)
189 {
190 	va_list args;
191 	const int pos = strlen(buffer);
192 
193 	va_start(args, fmt);
194 	vsnprintf(buffer + pos, len - pos - 1, fmt, args);
195 	va_end(args);
196 }
197 
198 /**
199  * tomoyo_flush - Flush queued string to userspace's buffer.
200  *
201  * @head:   Pointer to "struct tomoyo_io_buffer".
202  *
203  * Returns true if all data was flushed, false otherwise.
204  */
205 static bool tomoyo_flush(struct tomoyo_io_buffer *head)
206 {
207 	while (head->r.w_pos) {
208 		const char *w = head->r.w[0];
209 		size_t len = strlen(w);
210 
211 		if (len) {
212 			if (len > head->read_user_buf_avail)
213 				len = head->read_user_buf_avail;
214 			if (!len)
215 				return false;
216 			if (copy_to_user(head->read_user_buf, w, len))
217 				return false;
218 			head->read_user_buf_avail -= len;
219 			head->read_user_buf += len;
220 			w += len;
221 		}
222 		head->r.w[0] = w;
223 		if (*w)
224 			return false;
225 		/* Add '\0' for audit logs and query. */
226 		if (head->poll) {
227 			if (!head->read_user_buf_avail ||
228 			    copy_to_user(head->read_user_buf, "", 1))
229 				return false;
230 			head->read_user_buf_avail--;
231 			head->read_user_buf++;
232 		}
233 		head->r.w_pos--;
234 		for (len = 0; len < head->r.w_pos; len++)
235 			head->r.w[len] = head->r.w[len + 1];
236 	}
237 	head->r.avail = 0;
238 	return true;
239 }
240 
241 /**
242  * tomoyo_set_string - Queue string to "struct tomoyo_io_buffer" structure.
243  *
244  * @head:   Pointer to "struct tomoyo_io_buffer".
245  * @string: String to print.
246  *
247  * Note that @string has to be kept valid until @head is kfree()d.
248  * This means that char[] allocated on stack memory cannot be passed to
249  * this function. Use tomoyo_io_printf() for char[] allocated on stack memory.
250  */
251 static void tomoyo_set_string(struct tomoyo_io_buffer *head, const char *string)
252 {
253 	if (head->r.w_pos < TOMOYO_MAX_IO_READ_QUEUE) {
254 		head->r.w[head->r.w_pos++] = string;
255 		tomoyo_flush(head);
256 	} else
257 		WARN_ON(1);
258 }
259 
260 static void tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt,
261 			     ...) __printf(2, 3);
262 
263 /**
264  * tomoyo_io_printf - printf() to "struct tomoyo_io_buffer" structure.
265  *
266  * @head: Pointer to "struct tomoyo_io_buffer".
267  * @fmt:  The printf()'s format string, followed by parameters.
268  */
269 static void tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt,
270 			     ...)
271 {
272 	va_list args;
273 	size_t len;
274 	size_t pos = head->r.avail;
275 	int size = head->readbuf_size - pos;
276 
277 	if (size <= 0)
278 		return;
279 	va_start(args, fmt);
280 	len = vsnprintf(head->read_buf + pos, size, fmt, args) + 1;
281 	va_end(args);
282 	if (pos + len >= head->readbuf_size) {
283 		WARN_ON(1);
284 		return;
285 	}
286 	head->r.avail += len;
287 	tomoyo_set_string(head, head->read_buf + pos);
288 }
289 
290 /**
291  * tomoyo_set_space - Put a space to "struct tomoyo_io_buffer" structure.
292  *
293  * @head: Pointer to "struct tomoyo_io_buffer".
294  *
295  * Returns nothing.
296  */
297 static void tomoyo_set_space(struct tomoyo_io_buffer *head)
298 {
299 	tomoyo_set_string(head, " ");
300 }
301 
302 /**
303  * tomoyo_set_lf - Put a line feed to "struct tomoyo_io_buffer" structure.
304  *
305  * @head: Pointer to "struct tomoyo_io_buffer".
306  *
307  * Returns nothing.
308  */
309 static bool tomoyo_set_lf(struct tomoyo_io_buffer *head)
310 {
311 	tomoyo_set_string(head, "\n");
312 	return !head->r.w_pos;
313 }
314 
315 /**
316  * tomoyo_set_slash - Put a shash to "struct tomoyo_io_buffer" structure.
317  *
318  * @head: Pointer to "struct tomoyo_io_buffer".
319  *
320  * Returns nothing.
321  */
322 static void tomoyo_set_slash(struct tomoyo_io_buffer *head)
323 {
324 	tomoyo_set_string(head, "/");
325 }
326 
327 /* List of namespaces. */
328 LIST_HEAD(tomoyo_namespace_list);
329 /* True if namespace other than tomoyo_kernel_namespace is defined. */
330 static bool tomoyo_namespace_enabled;
331 
332 /**
333  * tomoyo_init_policy_namespace - Initialize namespace.
334  *
335  * @ns: Pointer to "struct tomoyo_policy_namespace".
336  *
337  * Returns nothing.
338  */
339 void tomoyo_init_policy_namespace(struct tomoyo_policy_namespace *ns)
340 {
341 	unsigned int idx;
342 
343 	for (idx = 0; idx < TOMOYO_MAX_ACL_GROUPS; idx++)
344 		INIT_LIST_HEAD(&ns->acl_group[idx]);
345 	for (idx = 0; idx < TOMOYO_MAX_GROUP; idx++)
346 		INIT_LIST_HEAD(&ns->group_list[idx]);
347 	for (idx = 0; idx < TOMOYO_MAX_POLICY; idx++)
348 		INIT_LIST_HEAD(&ns->policy_list[idx]);
349 	ns->profile_version = 20150505;
350 	tomoyo_namespace_enabled = !list_empty(&tomoyo_namespace_list);
351 	list_add_tail_rcu(&ns->namespace_list, &tomoyo_namespace_list);
352 }
353 
354 /**
355  * tomoyo_print_namespace - Print namespace header.
356  *
357  * @head: Pointer to "struct tomoyo_io_buffer".
358  *
359  * Returns nothing.
360  */
361 static void tomoyo_print_namespace(struct tomoyo_io_buffer *head)
362 {
363 	if (!tomoyo_namespace_enabled)
364 		return;
365 	tomoyo_set_string(head,
366 			  container_of(head->r.ns,
367 				       struct tomoyo_policy_namespace,
368 				       namespace_list)->name);
369 	tomoyo_set_space(head);
370 }
371 
372 /**
373  * tomoyo_print_name_union - Print a tomoyo_name_union.
374  *
375  * @head: Pointer to "struct tomoyo_io_buffer".
376  * @ptr:  Pointer to "struct tomoyo_name_union".
377  */
378 static void tomoyo_print_name_union(struct tomoyo_io_buffer *head,
379 				    const struct tomoyo_name_union *ptr)
380 {
381 	tomoyo_set_space(head);
382 	if (ptr->group) {
383 		tomoyo_set_string(head, "@");
384 		tomoyo_set_string(head, ptr->group->group_name->name);
385 	} else {
386 		tomoyo_set_string(head, ptr->filename->name);
387 	}
388 }
389 
390 /**
391  * tomoyo_print_name_union_quoted - Print a tomoyo_name_union with a quote.
392  *
393  * @head: Pointer to "struct tomoyo_io_buffer".
394  * @ptr:  Pointer to "struct tomoyo_name_union".
395  *
396  * Returns nothing.
397  */
398 static void tomoyo_print_name_union_quoted(struct tomoyo_io_buffer *head,
399 					   const struct tomoyo_name_union *ptr)
400 {
401 	if (ptr->group) {
402 		tomoyo_set_string(head, "@");
403 		tomoyo_set_string(head, ptr->group->group_name->name);
404 	} else {
405 		tomoyo_set_string(head, "\"");
406 		tomoyo_set_string(head, ptr->filename->name);
407 		tomoyo_set_string(head, "\"");
408 	}
409 }
410 
411 /**
412  * tomoyo_print_number_union_nospace - Print a tomoyo_number_union without a space.
413  *
414  * @head: Pointer to "struct tomoyo_io_buffer".
415  * @ptr:  Pointer to "struct tomoyo_number_union".
416  *
417  * Returns nothing.
418  */
419 static void tomoyo_print_number_union_nospace
420 (struct tomoyo_io_buffer *head, const struct tomoyo_number_union *ptr)
421 {
422 	if (ptr->group) {
423 		tomoyo_set_string(head, "@");
424 		tomoyo_set_string(head, ptr->group->group_name->name);
425 	} else {
426 		int i;
427 		unsigned long min = ptr->values[0];
428 		const unsigned long max = ptr->values[1];
429 		u8 min_type = ptr->value_type[0];
430 		const u8 max_type = ptr->value_type[1];
431 		char buffer[128];
432 
433 		buffer[0] = '\0';
434 		for (i = 0; i < 2; i++) {
435 			switch (min_type) {
436 			case TOMOYO_VALUE_TYPE_HEXADECIMAL:
437 				tomoyo_addprintf(buffer, sizeof(buffer),
438 						 "0x%lX", min);
439 				break;
440 			case TOMOYO_VALUE_TYPE_OCTAL:
441 				tomoyo_addprintf(buffer, sizeof(buffer),
442 						 "0%lo", min);
443 				break;
444 			default:
445 				tomoyo_addprintf(buffer, sizeof(buffer), "%lu",
446 						 min);
447 				break;
448 			}
449 			if (min == max && min_type == max_type)
450 				break;
451 			tomoyo_addprintf(buffer, sizeof(buffer), "-");
452 			min_type = max_type;
453 			min = max;
454 		}
455 		tomoyo_io_printf(head, "%s", buffer);
456 	}
457 }
458 
459 /**
460  * tomoyo_print_number_union - Print a tomoyo_number_union.
461  *
462  * @head: Pointer to "struct tomoyo_io_buffer".
463  * @ptr:  Pointer to "struct tomoyo_number_union".
464  *
465  * Returns nothing.
466  */
467 static void tomoyo_print_number_union(struct tomoyo_io_buffer *head,
468 				      const struct tomoyo_number_union *ptr)
469 {
470 	tomoyo_set_space(head);
471 	tomoyo_print_number_union_nospace(head, ptr);
472 }
473 
474 /**
475  * tomoyo_assign_profile - Create a new profile.
476  *
477  * @ns:      Pointer to "struct tomoyo_policy_namespace".
478  * @profile: Profile number to create.
479  *
480  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
481  */
482 static struct tomoyo_profile *tomoyo_assign_profile
483 (struct tomoyo_policy_namespace *ns, const unsigned int profile)
484 {
485 	struct tomoyo_profile *ptr;
486 	struct tomoyo_profile *entry;
487 
488 	if (profile >= TOMOYO_MAX_PROFILES)
489 		return NULL;
490 	ptr = ns->profile_ptr[profile];
491 	if (ptr)
492 		return ptr;
493 	entry = kzalloc(sizeof(*entry), GFP_NOFS | __GFP_NOWARN);
494 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
495 		goto out;
496 	ptr = ns->profile_ptr[profile];
497 	if (!ptr && tomoyo_memory_ok(entry)) {
498 		ptr = entry;
499 		ptr->default_config = TOMOYO_CONFIG_DISABLED |
500 			TOMOYO_CONFIG_WANT_GRANT_LOG |
501 			TOMOYO_CONFIG_WANT_REJECT_LOG;
502 		memset(ptr->config, TOMOYO_CONFIG_USE_DEFAULT,
503 		       sizeof(ptr->config));
504 		ptr->pref[TOMOYO_PREF_MAX_AUDIT_LOG] =
505 			CONFIG_SECURITY_TOMOYO_MAX_AUDIT_LOG;
506 		ptr->pref[TOMOYO_PREF_MAX_LEARNING_ENTRY] =
507 			CONFIG_SECURITY_TOMOYO_MAX_ACCEPT_ENTRY;
508 		mb(); /* Avoid out-of-order execution. */
509 		ns->profile_ptr[profile] = ptr;
510 		entry = NULL;
511 	}
512 	mutex_unlock(&tomoyo_policy_lock);
513  out:
514 	kfree(entry);
515 	return ptr;
516 }
517 
518 /**
519  * tomoyo_profile - Find a profile.
520  *
521  * @ns:      Pointer to "struct tomoyo_policy_namespace".
522  * @profile: Profile number to find.
523  *
524  * Returns pointer to "struct tomoyo_profile".
525  */
526 struct tomoyo_profile *tomoyo_profile(const struct tomoyo_policy_namespace *ns,
527 				      const u8 profile)
528 {
529 	static struct tomoyo_profile tomoyo_null_profile;
530 	struct tomoyo_profile *ptr = ns->profile_ptr[profile];
531 
532 	if (!ptr)
533 		ptr = &tomoyo_null_profile;
534 	return ptr;
535 }
536 
537 /**
538  * tomoyo_find_yesno - Find values for specified keyword.
539  *
540  * @string: String to check.
541  * @find:   Name of keyword.
542  *
543  * Returns 1 if "@find=yes" was found, 0 if "@find=no" was found, -1 otherwise.
544  */
545 static s8 tomoyo_find_yesno(const char *string, const char *find)
546 {
547 	const char *cp = strstr(string, find);
548 
549 	if (cp) {
550 		cp += strlen(find);
551 		if (!strncmp(cp, "=yes", 4))
552 			return 1;
553 		else if (!strncmp(cp, "=no", 3))
554 			return 0;
555 	}
556 	return -1;
557 }
558 
559 /**
560  * tomoyo_set_uint - Set value for specified preference.
561  *
562  * @i:      Pointer to "unsigned int".
563  * @string: String to check.
564  * @find:   Name of keyword.
565  *
566  * Returns nothing.
567  */
568 static void tomoyo_set_uint(unsigned int *i, const char *string,
569 			    const char *find)
570 {
571 	const char *cp = strstr(string, find);
572 
573 	if (cp)
574 		sscanf(cp + strlen(find), "=%u", i);
575 }
576 
577 /**
578  * tomoyo_set_mode - Set mode for specified profile.
579  *
580  * @name:    Name of functionality.
581  * @value:   Mode for @name.
582  * @profile: Pointer to "struct tomoyo_profile".
583  *
584  * Returns 0 on success, negative value otherwise.
585  */
586 static int tomoyo_set_mode(char *name, const char *value,
587 			   struct tomoyo_profile *profile)
588 {
589 	u8 i;
590 	u8 config;
591 
592 	if (!strcmp(name, "CONFIG")) {
593 		i = TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX;
594 		config = profile->default_config;
595 	} else if (tomoyo_str_starts(&name, "CONFIG::")) {
596 		config = 0;
597 		for (i = 0; i < TOMOYO_MAX_MAC_INDEX
598 			     + TOMOYO_MAX_MAC_CATEGORY_INDEX; i++) {
599 			int len = 0;
600 
601 			if (i < TOMOYO_MAX_MAC_INDEX) {
602 				const u8 c = tomoyo_index2category[i];
603 				const char *category =
604 					tomoyo_category_keywords[c];
605 
606 				len = strlen(category);
607 				if (strncmp(name, category, len) ||
608 				    name[len++] != ':' || name[len++] != ':')
609 					continue;
610 			}
611 			if (strcmp(name + len, tomoyo_mac_keywords[i]))
612 				continue;
613 			config = profile->config[i];
614 			break;
615 		}
616 		if (i == TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX)
617 			return -EINVAL;
618 	} else {
619 		return -EINVAL;
620 	}
621 	if (strstr(value, "use_default")) {
622 		config = TOMOYO_CONFIG_USE_DEFAULT;
623 	} else {
624 		u8 mode;
625 
626 		for (mode = 0; mode < 4; mode++)
627 			if (strstr(value, tomoyo_mode[mode]))
628 				/*
629 				 * Update lower 3 bits in order to distinguish
630 				 * 'config' from 'TOMOYO_CONFIG_USE_DEFAULT'.
631 				 */
632 				config = (config & ~7) | mode;
633 		if (config != TOMOYO_CONFIG_USE_DEFAULT) {
634 			switch (tomoyo_find_yesno(value, "grant_log")) {
635 			case 1:
636 				config |= TOMOYO_CONFIG_WANT_GRANT_LOG;
637 				break;
638 			case 0:
639 				config &= ~TOMOYO_CONFIG_WANT_GRANT_LOG;
640 				break;
641 			}
642 			switch (tomoyo_find_yesno(value, "reject_log")) {
643 			case 1:
644 				config |= TOMOYO_CONFIG_WANT_REJECT_LOG;
645 				break;
646 			case 0:
647 				config &= ~TOMOYO_CONFIG_WANT_REJECT_LOG;
648 				break;
649 			}
650 		}
651 	}
652 	if (i < TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX)
653 		profile->config[i] = config;
654 	else if (config != TOMOYO_CONFIG_USE_DEFAULT)
655 		profile->default_config = config;
656 	return 0;
657 }
658 
659 /**
660  * tomoyo_write_profile - Write profile table.
661  *
662  * @head: Pointer to "struct tomoyo_io_buffer".
663  *
664  * Returns 0 on success, negative value otherwise.
665  */
666 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
667 {
668 	char *data = head->write_buf;
669 	unsigned int i;
670 	char *cp;
671 	struct tomoyo_profile *profile;
672 
673 	if (sscanf(data, "PROFILE_VERSION=%u", &head->w.ns->profile_version)
674 	    == 1)
675 		return 0;
676 	i = simple_strtoul(data, &cp, 10);
677 	if (*cp != '-')
678 		return -EINVAL;
679 	data = cp + 1;
680 	profile = tomoyo_assign_profile(head->w.ns, i);
681 	if (!profile)
682 		return -EINVAL;
683 	cp = strchr(data, '=');
684 	if (!cp)
685 		return -EINVAL;
686 	*cp++ = '\0';
687 	if (!strcmp(data, "COMMENT")) {
688 		static DEFINE_SPINLOCK(lock);
689 		const struct tomoyo_path_info *new_comment
690 			= tomoyo_get_name(cp);
691 		const struct tomoyo_path_info *old_comment;
692 
693 		if (!new_comment)
694 			return -ENOMEM;
695 		spin_lock(&lock);
696 		old_comment = profile->comment;
697 		profile->comment = new_comment;
698 		spin_unlock(&lock);
699 		tomoyo_put_name(old_comment);
700 		return 0;
701 	}
702 	if (!strcmp(data, "PREFERENCE")) {
703 		for (i = 0; i < TOMOYO_MAX_PREF; i++)
704 			tomoyo_set_uint(&profile->pref[i], cp,
705 					tomoyo_pref_keywords[i]);
706 		return 0;
707 	}
708 	return tomoyo_set_mode(data, cp, profile);
709 }
710 
711 /**
712  * tomoyo_print_config - Print mode for specified functionality.
713  *
714  * @head:   Pointer to "struct tomoyo_io_buffer".
715  * @config: Mode for that functionality.
716  *
717  * Returns nothing.
718  *
719  * Caller prints functionality's name.
720  */
721 static void tomoyo_print_config(struct tomoyo_io_buffer *head, const u8 config)
722 {
723 	tomoyo_io_printf(head, "={ mode=%s grant_log=%s reject_log=%s }\n",
724 			 tomoyo_mode[config & 3],
725 			 str_yes_no(config & TOMOYO_CONFIG_WANT_GRANT_LOG),
726 			 str_yes_no(config & TOMOYO_CONFIG_WANT_REJECT_LOG));
727 }
728 
729 /**
730  * tomoyo_read_profile - Read profile table.
731  *
732  * @head: Pointer to "struct tomoyo_io_buffer".
733  *
734  * Returns nothing.
735  */
736 static void tomoyo_read_profile(struct tomoyo_io_buffer *head)
737 {
738 	u8 index;
739 	struct tomoyo_policy_namespace *ns =
740 		container_of(head->r.ns, typeof(*ns), namespace_list);
741 	const struct tomoyo_profile *profile;
742 
743 	if (head->r.eof)
744 		return;
745  next:
746 	index = head->r.index;
747 	profile = ns->profile_ptr[index];
748 	switch (head->r.step) {
749 	case 0:
750 		tomoyo_print_namespace(head);
751 		tomoyo_io_printf(head, "PROFILE_VERSION=%u\n",
752 				 ns->profile_version);
753 		head->r.step++;
754 		break;
755 	case 1:
756 		for ( ; head->r.index < TOMOYO_MAX_PROFILES;
757 		      head->r.index++)
758 			if (ns->profile_ptr[head->r.index])
759 				break;
760 		if (head->r.index == TOMOYO_MAX_PROFILES) {
761 			head->r.eof = true;
762 			return;
763 		}
764 		head->r.step++;
765 		break;
766 	case 2:
767 		{
768 			u8 i;
769 			const struct tomoyo_path_info *comment =
770 				profile->comment;
771 
772 			tomoyo_print_namespace(head);
773 			tomoyo_io_printf(head, "%u-COMMENT=", index);
774 			tomoyo_set_string(head, comment ? comment->name : "");
775 			tomoyo_set_lf(head);
776 			tomoyo_print_namespace(head);
777 			tomoyo_io_printf(head, "%u-PREFERENCE={ ", index);
778 			for (i = 0; i < TOMOYO_MAX_PREF; i++)
779 				tomoyo_io_printf(head, "%s=%u ",
780 						 tomoyo_pref_keywords[i],
781 						 profile->pref[i]);
782 			tomoyo_set_string(head, "}\n");
783 			head->r.step++;
784 		}
785 		break;
786 	case 3:
787 		{
788 			tomoyo_print_namespace(head);
789 			tomoyo_io_printf(head, "%u-%s", index, "CONFIG");
790 			tomoyo_print_config(head, profile->default_config);
791 			head->r.bit = 0;
792 			head->r.step++;
793 		}
794 		break;
795 	case 4:
796 		for ( ; head->r.bit < TOMOYO_MAX_MAC_INDEX
797 			      + TOMOYO_MAX_MAC_CATEGORY_INDEX; head->r.bit++) {
798 			const u8 i = head->r.bit;
799 			const u8 config = profile->config[i];
800 
801 			if (config == TOMOYO_CONFIG_USE_DEFAULT)
802 				continue;
803 			tomoyo_print_namespace(head);
804 			if (i < TOMOYO_MAX_MAC_INDEX)
805 				tomoyo_io_printf(head, "%u-CONFIG::%s::%s",
806 						 index,
807 						 tomoyo_category_keywords
808 						 [tomoyo_index2category[i]],
809 						 tomoyo_mac_keywords[i]);
810 			else
811 				tomoyo_io_printf(head, "%u-CONFIG::%s", index,
812 						 tomoyo_mac_keywords[i]);
813 			tomoyo_print_config(head, config);
814 			head->r.bit++;
815 			break;
816 		}
817 		if (head->r.bit == TOMOYO_MAX_MAC_INDEX
818 		    + TOMOYO_MAX_MAC_CATEGORY_INDEX) {
819 			head->r.index++;
820 			head->r.step = 1;
821 		}
822 		break;
823 	}
824 	if (tomoyo_flush(head))
825 		goto next;
826 }
827 
828 /**
829  * tomoyo_same_manager - Check for duplicated "struct tomoyo_manager" entry.
830  *
831  * @a: Pointer to "struct tomoyo_acl_head".
832  * @b: Pointer to "struct tomoyo_acl_head".
833  *
834  * Returns true if @a == @b, false otherwise.
835  */
836 static bool tomoyo_same_manager(const struct tomoyo_acl_head *a,
837 				const struct tomoyo_acl_head *b)
838 {
839 	return container_of(a, struct tomoyo_manager, head)->manager ==
840 		container_of(b, struct tomoyo_manager, head)->manager;
841 }
842 
843 /**
844  * tomoyo_update_manager_entry - Add a manager entry.
845  *
846  * @manager:   The path to manager or the domainnamme.
847  * @is_delete: True if it is a delete request.
848  *
849  * Returns 0 on success, negative value otherwise.
850  *
851  * Caller holds tomoyo_read_lock().
852  */
853 static int tomoyo_update_manager_entry(const char *manager,
854 				       const bool is_delete)
855 {
856 	struct tomoyo_manager e = { };
857 	struct tomoyo_acl_param param = {
858 		/* .ns = &tomoyo_kernel_namespace, */
859 		.is_delete = is_delete,
860 		.list = &tomoyo_kernel_namespace.policy_list[TOMOYO_ID_MANAGER],
861 	};
862 	int error = is_delete ? -ENOENT : -ENOMEM;
863 
864 	if (!tomoyo_correct_domain(manager) &&
865 	    !tomoyo_correct_word(manager))
866 		return -EINVAL;
867 	e.manager = tomoyo_get_name(manager);
868 	if (e.manager) {
869 		error = tomoyo_update_policy(&e.head, sizeof(e), &param,
870 					     tomoyo_same_manager);
871 		tomoyo_put_name(e.manager);
872 	}
873 	return error;
874 }
875 
876 /**
877  * tomoyo_write_manager - Write manager policy.
878  *
879  * @head: Pointer to "struct tomoyo_io_buffer".
880  *
881  * Returns 0 on success, negative value otherwise.
882  *
883  * Caller holds tomoyo_read_lock().
884  */
885 static int tomoyo_write_manager(struct tomoyo_io_buffer *head)
886 {
887 	char *data = head->write_buf;
888 
889 	if (!strcmp(data, "manage_by_non_root")) {
890 		tomoyo_manage_by_non_root = !head->w.is_delete;
891 		return 0;
892 	}
893 	return tomoyo_update_manager_entry(data, head->w.is_delete);
894 }
895 
896 /**
897  * tomoyo_read_manager - Read manager policy.
898  *
899  * @head: Pointer to "struct tomoyo_io_buffer".
900  *
901  * Caller holds tomoyo_read_lock().
902  */
903 static void tomoyo_read_manager(struct tomoyo_io_buffer *head)
904 {
905 	if (head->r.eof)
906 		return;
907 	list_for_each_cookie(head->r.acl, &tomoyo_kernel_namespace.policy_list[TOMOYO_ID_MANAGER]) {
908 		struct tomoyo_manager *ptr =
909 			list_entry(head->r.acl, typeof(*ptr), head.list);
910 
911 		if (ptr->head.is_deleted)
912 			continue;
913 		if (!tomoyo_flush(head))
914 			return;
915 		tomoyo_set_string(head, ptr->manager->name);
916 		tomoyo_set_lf(head);
917 	}
918 	head->r.eof = true;
919 }
920 
921 /**
922  * tomoyo_manager - Check whether the current process is a policy manager.
923  *
924  * Returns true if the current process is permitted to modify policy
925  * via /sys/kernel/security/tomoyo/ interface.
926  *
927  * Caller holds tomoyo_read_lock().
928  */
929 static bool tomoyo_manager(void)
930 {
931 	struct tomoyo_manager *ptr;
932 	const char *exe;
933 	const struct task_struct *task = current;
934 	const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
935 	bool found = IS_ENABLED(CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING);
936 
937 	if (!tomoyo_policy_loaded)
938 		return true;
939 	if (!tomoyo_manage_by_non_root &&
940 	    (!uid_eq(task->cred->uid,  GLOBAL_ROOT_UID) ||
941 	     !uid_eq(task->cred->euid, GLOBAL_ROOT_UID)))
942 		return false;
943 	exe = tomoyo_get_exe();
944 	if (!exe)
945 		return false;
946 	list_for_each_entry_rcu(ptr, &tomoyo_kernel_namespace.policy_list[TOMOYO_ID_MANAGER], head.list,
947 				srcu_read_lock_held(&tomoyo_ss)) {
948 		if (!ptr->head.is_deleted &&
949 		    (!tomoyo_pathcmp(domainname, ptr->manager) ||
950 		     !strcmp(exe, ptr->manager->name))) {
951 			found = true;
952 			break;
953 		}
954 	}
955 	if (!found) { /* Reduce error messages. */
956 		static pid_t last_pid;
957 		const pid_t pid = current->pid;
958 
959 		if (last_pid != pid) {
960 			pr_warn("%s ( %s ) is not permitted to update policies.\n",
961 				domainname->name, exe);
962 			last_pid = pid;
963 		}
964 	}
965 	kfree(exe);
966 	return found;
967 }
968 
969 static struct tomoyo_domain_info *tomoyo_find_domain_by_qid
970 (unsigned int serial);
971 
972 /**
973  * tomoyo_select_domain - Parse select command.
974  *
975  * @head: Pointer to "struct tomoyo_io_buffer".
976  * @data: String to parse.
977  *
978  * Returns true on success, false otherwise.
979  *
980  * Caller holds tomoyo_read_lock().
981  */
982 static bool tomoyo_select_domain(struct tomoyo_io_buffer *head,
983 				 const char *data)
984 {
985 	unsigned int pid;
986 	struct tomoyo_domain_info *domain = NULL;
987 	bool global_pid = false;
988 
989 	if (strncmp(data, "select ", 7))
990 		return false;
991 	data += 7;
992 	if (sscanf(data, "pid=%u", &pid) == 1 ||
993 	    (global_pid = true, sscanf(data, "global-pid=%u", &pid) == 1)) {
994 		struct task_struct *p;
995 
996 		rcu_read_lock();
997 		if (global_pid)
998 			p = find_task_by_pid_ns(pid, &init_pid_ns);
999 		else
1000 			p = find_task_by_vpid(pid);
1001 		if (p)
1002 			domain = tomoyo_task(p)->domain_info;
1003 		rcu_read_unlock();
1004 	} else if (!strncmp(data, "domain=", 7)) {
1005 		if (tomoyo_domain_def(data + 7))
1006 			domain = tomoyo_find_domain(data + 7);
1007 	} else if (sscanf(data, "Q=%u", &pid) == 1) {
1008 		domain = tomoyo_find_domain_by_qid(pid);
1009 	} else
1010 		return false;
1011 	head->w.domain = domain;
1012 	/* Accessing read_buf is safe because head->io_sem is held. */
1013 	if (!head->read_buf)
1014 		return true; /* Do nothing if open(O_WRONLY). */
1015 	memset(&head->r, 0, sizeof(head->r));
1016 	head->r.print_this_domain_only = true;
1017 	if (domain)
1018 		head->r.domain = &domain->list;
1019 	else
1020 		head->r.eof = true;
1021 	tomoyo_io_printf(head, "# select %s\n", data);
1022 	if (domain && domain->is_deleted)
1023 		tomoyo_io_printf(head, "# This is a deleted domain.\n");
1024 	return true;
1025 }
1026 
1027 /**
1028  * tomoyo_same_task_acl - Check for duplicated "struct tomoyo_task_acl" entry.
1029  *
1030  * @a: Pointer to "struct tomoyo_acl_info".
1031  * @b: Pointer to "struct tomoyo_acl_info".
1032  *
1033  * Returns true if @a == @b, false otherwise.
1034  */
1035 static bool tomoyo_same_task_acl(const struct tomoyo_acl_info *a,
1036 				 const struct tomoyo_acl_info *b)
1037 {
1038 	const struct tomoyo_task_acl *p1 = container_of(a, typeof(*p1), head);
1039 	const struct tomoyo_task_acl *p2 = container_of(b, typeof(*p2), head);
1040 
1041 	return p1->domainname == p2->domainname;
1042 }
1043 
1044 /**
1045  * tomoyo_write_task - Update task related list.
1046  *
1047  * @param: Pointer to "struct tomoyo_acl_param".
1048  *
1049  * Returns 0 on success, negative value otherwise.
1050  *
1051  * Caller holds tomoyo_read_lock().
1052  */
1053 static int tomoyo_write_task(struct tomoyo_acl_param *param)
1054 {
1055 	int error = -EINVAL;
1056 
1057 	if (tomoyo_str_starts(&param->data, "manual_domain_transition ")) {
1058 		struct tomoyo_task_acl e = {
1059 			.head.type = TOMOYO_TYPE_MANUAL_TASK_ACL,
1060 			.domainname = tomoyo_get_domainname(param),
1061 		};
1062 
1063 		if (e.domainname)
1064 			error = tomoyo_update_domain(&e.head, sizeof(e), param,
1065 						     tomoyo_same_task_acl,
1066 						     NULL);
1067 		tomoyo_put_name(e.domainname);
1068 	}
1069 	return error;
1070 }
1071 
1072 /**
1073  * tomoyo_delete_domain - Delete a domain.
1074  *
1075  * @domainname: The name of domain.
1076  *
1077  * Returns 0 on success, negative value otherwise.
1078  *
1079  * Caller holds tomoyo_read_lock().
1080  */
1081 static int tomoyo_delete_domain(char *domainname)
1082 {
1083 	struct tomoyo_domain_info *domain;
1084 	struct tomoyo_path_info name;
1085 
1086 	name.name = domainname;
1087 	tomoyo_fill_path_info(&name);
1088 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
1089 		return -EINTR;
1090 	/* Is there an active domain? */
1091 	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list,
1092 				srcu_read_lock_held(&tomoyo_ss)) {
1093 		/* Never delete tomoyo_kernel_domain */
1094 		if (domain == &tomoyo_kernel_domain)
1095 			continue;
1096 		if (domain->is_deleted ||
1097 		    tomoyo_pathcmp(domain->domainname, &name))
1098 			continue;
1099 		domain->is_deleted = true;
1100 		break;
1101 	}
1102 	mutex_unlock(&tomoyo_policy_lock);
1103 	return 0;
1104 }
1105 
1106 /**
1107  * tomoyo_write_domain2 - Write domain policy.
1108  *
1109  * @ns:        Pointer to "struct tomoyo_policy_namespace".
1110  * @list:      Pointer to "struct list_head".
1111  * @data:      Policy to be interpreted.
1112  * @is_delete: True if it is a delete request.
1113  *
1114  * Returns 0 on success, negative value otherwise.
1115  *
1116  * Caller holds tomoyo_read_lock().
1117  */
1118 static int tomoyo_write_domain2(struct tomoyo_policy_namespace *ns,
1119 				struct list_head *list, char *data,
1120 				const bool is_delete)
1121 {
1122 	struct tomoyo_acl_param param = {
1123 		.ns = ns,
1124 		.list = list,
1125 		.data = data,
1126 		.is_delete = is_delete,
1127 	};
1128 	static const struct {
1129 		const char *keyword;
1130 		int (*write)(struct tomoyo_acl_param *param);
1131 	} tomoyo_callback[5] = {
1132 		{ "file ", tomoyo_write_file },
1133 		{ "network inet ", tomoyo_write_inet_network },
1134 		{ "network unix ", tomoyo_write_unix_network },
1135 		{ "misc ", tomoyo_write_misc },
1136 		{ "task ", tomoyo_write_task },
1137 	};
1138 	u8 i;
1139 
1140 	for (i = 0; i < ARRAY_SIZE(tomoyo_callback); i++) {
1141 		if (!tomoyo_str_starts(&param.data,
1142 				       tomoyo_callback[i].keyword))
1143 			continue;
1144 		return tomoyo_callback[i].write(&param);
1145 	}
1146 	return -EINVAL;
1147 }
1148 
1149 /* String table for domain flags. */
1150 const char * const tomoyo_dif[TOMOYO_MAX_DOMAIN_INFO_FLAGS] = {
1151 	[TOMOYO_DIF_QUOTA_WARNED]      = "quota_exceeded\n",
1152 	[TOMOYO_DIF_TRANSITION_FAILED] = "transition_failed\n",
1153 };
1154 
1155 /**
1156  * tomoyo_write_domain - Write domain policy.
1157  *
1158  * @head: Pointer to "struct tomoyo_io_buffer".
1159  *
1160  * Returns 0 on success, negative value otherwise.
1161  *
1162  * Caller holds tomoyo_read_lock().
1163  */
1164 static int tomoyo_write_domain(struct tomoyo_io_buffer *head)
1165 {
1166 	char *data = head->write_buf;
1167 	struct tomoyo_policy_namespace *ns;
1168 	struct tomoyo_domain_info *domain = head->w.domain;
1169 	const bool is_delete = head->w.is_delete;
1170 	bool is_select = !is_delete && tomoyo_str_starts(&data, "select ");
1171 	unsigned int idx;
1172 
1173 	if (*data == '<') {
1174 		int ret = 0;
1175 
1176 		domain = NULL;
1177 		if (is_delete)
1178 			ret = tomoyo_delete_domain(data);
1179 		else if (is_select)
1180 			domain = tomoyo_find_domain(data);
1181 		else
1182 			domain = tomoyo_assign_domain(data, false);
1183 		head->w.domain = domain;
1184 		return ret;
1185 	}
1186 	if (!domain)
1187 		return -EINVAL;
1188 	ns = domain->ns;
1189 	if (sscanf(data, "use_profile %u", &idx) == 1
1190 	    && idx < TOMOYO_MAX_PROFILES) {
1191 		if (!tomoyo_policy_loaded || ns->profile_ptr[idx])
1192 			if (!is_delete)
1193 				domain->profile = (u8) idx;
1194 		return 0;
1195 	}
1196 	if (sscanf(data, "use_group %u\n", &idx) == 1
1197 	    && idx < TOMOYO_MAX_ACL_GROUPS) {
1198 		if (!is_delete)
1199 			set_bit(idx, domain->group);
1200 		else
1201 			clear_bit(idx, domain->group);
1202 		return 0;
1203 	}
1204 	for (idx = 0; idx < TOMOYO_MAX_DOMAIN_INFO_FLAGS; idx++) {
1205 		const char *cp = tomoyo_dif[idx];
1206 
1207 		if (strncmp(data, cp, strlen(cp) - 1))
1208 			continue;
1209 		domain->flags[idx] = !is_delete;
1210 		return 0;
1211 	}
1212 	return tomoyo_write_domain2(ns, &domain->acl_info_list, data,
1213 				    is_delete);
1214 }
1215 
1216 /**
1217  * tomoyo_print_condition - Print condition part.
1218  *
1219  * @head: Pointer to "struct tomoyo_io_buffer".
1220  * @cond: Pointer to "struct tomoyo_condition".
1221  *
1222  * Returns true on success, false otherwise.
1223  */
1224 static bool tomoyo_print_condition(struct tomoyo_io_buffer *head,
1225 				   const struct tomoyo_condition *cond)
1226 {
1227 	switch (head->r.cond_step) {
1228 	case 0:
1229 		head->r.cond_index = 0;
1230 		head->r.cond_step++;
1231 		if (cond->transit) {
1232 			tomoyo_set_space(head);
1233 			tomoyo_set_string(head, cond->transit->name);
1234 		}
1235 		fallthrough;
1236 	case 1:
1237 		{
1238 			const u16 condc = cond->condc;
1239 			const struct tomoyo_condition_element *condp =
1240 				(typeof(condp)) (cond + 1);
1241 			const struct tomoyo_number_union *numbers_p =
1242 				(typeof(numbers_p)) (condp + condc);
1243 			const struct tomoyo_name_union *names_p =
1244 				(typeof(names_p))
1245 				(numbers_p + cond->numbers_count);
1246 			const struct tomoyo_argv *argv =
1247 				(typeof(argv)) (names_p + cond->names_count);
1248 			const struct tomoyo_envp *envp =
1249 				(typeof(envp)) (argv + cond->argc);
1250 			u16 skip;
1251 
1252 			for (skip = 0; skip < head->r.cond_index; skip++) {
1253 				const u8 left = condp->left;
1254 				const u8 right = condp->right;
1255 
1256 				condp++;
1257 				switch (left) {
1258 				case TOMOYO_ARGV_ENTRY:
1259 					argv++;
1260 					continue;
1261 				case TOMOYO_ENVP_ENTRY:
1262 					envp++;
1263 					continue;
1264 				case TOMOYO_NUMBER_UNION:
1265 					numbers_p++;
1266 					break;
1267 				}
1268 				switch (right) {
1269 				case TOMOYO_NAME_UNION:
1270 					names_p++;
1271 					break;
1272 				case TOMOYO_NUMBER_UNION:
1273 					numbers_p++;
1274 					break;
1275 				}
1276 			}
1277 			while (head->r.cond_index < condc) {
1278 				const u8 match = condp->equals;
1279 				const u8 left = condp->left;
1280 				const u8 right = condp->right;
1281 
1282 				if (!tomoyo_flush(head))
1283 					return false;
1284 				condp++;
1285 				head->r.cond_index++;
1286 				tomoyo_set_space(head);
1287 				switch (left) {
1288 				case TOMOYO_ARGV_ENTRY:
1289 					tomoyo_io_printf(head,
1290 							 "exec.argv[%lu]%s=\"",
1291 							 argv->index, argv->is_not ? "!" : "");
1292 					tomoyo_set_string(head,
1293 							  argv->value->name);
1294 					tomoyo_set_string(head, "\"");
1295 					argv++;
1296 					continue;
1297 				case TOMOYO_ENVP_ENTRY:
1298 					tomoyo_set_string(head,
1299 							  "exec.envp[\"");
1300 					tomoyo_set_string(head,
1301 							  envp->name->name);
1302 					tomoyo_io_printf(head, "\"]%s=", envp->is_not ? "!" : "");
1303 					if (envp->value) {
1304 						tomoyo_set_string(head, "\"");
1305 						tomoyo_set_string(head, envp->value->name);
1306 						tomoyo_set_string(head, "\"");
1307 					} else {
1308 						tomoyo_set_string(head,
1309 								  "NULL");
1310 					}
1311 					envp++;
1312 					continue;
1313 				case TOMOYO_NUMBER_UNION:
1314 					tomoyo_print_number_union_nospace
1315 						(head, numbers_p++);
1316 					break;
1317 				default:
1318 					tomoyo_set_string(head,
1319 					       tomoyo_condition_keyword[left]);
1320 					break;
1321 				}
1322 				tomoyo_set_string(head, match ? "=" : "!=");
1323 				switch (right) {
1324 				case TOMOYO_NAME_UNION:
1325 					tomoyo_print_name_union_quoted
1326 						(head, names_p++);
1327 					break;
1328 				case TOMOYO_NUMBER_UNION:
1329 					tomoyo_print_number_union_nospace
1330 						(head, numbers_p++);
1331 					break;
1332 				default:
1333 					tomoyo_set_string(head,
1334 					  tomoyo_condition_keyword[right]);
1335 					break;
1336 				}
1337 			}
1338 		}
1339 		head->r.cond_step++;
1340 		fallthrough;
1341 	case 2:
1342 		if (!tomoyo_flush(head))
1343 			break;
1344 		head->r.cond_step++;
1345 		fallthrough;
1346 	case 3:
1347 		if (cond->grant_log != TOMOYO_GRANTLOG_AUTO)
1348 			tomoyo_io_printf(head, " grant_log=%s",
1349 					 str_yes_no(cond->grant_log ==
1350 						    TOMOYO_GRANTLOG_YES));
1351 		tomoyo_set_lf(head);
1352 		return true;
1353 	}
1354 	return false;
1355 }
1356 
1357 /**
1358  * tomoyo_set_group - Print "acl_group " header keyword and category name.
1359  *
1360  * @head:     Pointer to "struct tomoyo_io_buffer".
1361  * @category: Category name.
1362  *
1363  * Returns nothing.
1364  */
1365 static void tomoyo_set_group(struct tomoyo_io_buffer *head,
1366 			     const char *category)
1367 {
1368 	if (head->type == TOMOYO_EXCEPTIONPOLICY) {
1369 		tomoyo_print_namespace(head);
1370 		tomoyo_io_printf(head, "acl_group %u ",
1371 				 head->r.acl_group_index);
1372 	}
1373 	tomoyo_set_string(head, category);
1374 }
1375 
1376 /**
1377  * tomoyo_print_entry - Print an ACL entry.
1378  *
1379  * @head: Pointer to "struct tomoyo_io_buffer".
1380  * @acl:  Pointer to an ACL entry.
1381  *
1382  * Returns true on success, false otherwise.
1383  */
1384 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1385 			       struct tomoyo_acl_info *acl)
1386 {
1387 	const u8 acl_type = acl->type;
1388 	bool first = true;
1389 	u8 bit;
1390 
1391 	if (head->r.print_cond_part)
1392 		goto print_cond_part;
1393 	if (acl->is_deleted)
1394 		return true;
1395 	if (!tomoyo_flush(head))
1396 		return false;
1397 	else if (acl_type == TOMOYO_TYPE_PATH_ACL) {
1398 		struct tomoyo_path_acl *ptr =
1399 			container_of(acl, typeof(*ptr), head);
1400 		const u16 perm = ptr->perm;
1401 
1402 		for (bit = 0; bit < TOMOYO_MAX_PATH_OPERATION; bit++) {
1403 			if (!(perm & (1 << bit)))
1404 				continue;
1405 			if (head->r.print_transition_related_only &&
1406 			    bit != TOMOYO_TYPE_EXECUTE)
1407 				continue;
1408 			if (first) {
1409 				tomoyo_set_group(head, "file ");
1410 				first = false;
1411 			} else {
1412 				tomoyo_set_slash(head);
1413 			}
1414 			tomoyo_set_string(head, tomoyo_path_keyword[bit]);
1415 		}
1416 		if (first)
1417 			return true;
1418 		tomoyo_print_name_union(head, &ptr->name);
1419 	} else if (acl_type == TOMOYO_TYPE_MANUAL_TASK_ACL) {
1420 		struct tomoyo_task_acl *ptr =
1421 			container_of(acl, typeof(*ptr), head);
1422 
1423 		tomoyo_set_group(head, "task ");
1424 		tomoyo_set_string(head, "manual_domain_transition ");
1425 		tomoyo_set_string(head, ptr->domainname->name);
1426 	} else if (head->r.print_transition_related_only) {
1427 		return true;
1428 	} else if (acl_type == TOMOYO_TYPE_PATH2_ACL) {
1429 		struct tomoyo_path2_acl *ptr =
1430 			container_of(acl, typeof(*ptr), head);
1431 		const u8 perm = ptr->perm;
1432 
1433 		for (bit = 0; bit < TOMOYO_MAX_PATH2_OPERATION; bit++) {
1434 			if (!(perm & (1 << bit)))
1435 				continue;
1436 			if (first) {
1437 				tomoyo_set_group(head, "file ");
1438 				first = false;
1439 			} else {
1440 				tomoyo_set_slash(head);
1441 			}
1442 			tomoyo_set_string(head, tomoyo_mac_keywords
1443 					  [tomoyo_pp2mac[bit]]);
1444 		}
1445 		if (first)
1446 			return true;
1447 		tomoyo_print_name_union(head, &ptr->name1);
1448 		tomoyo_print_name_union(head, &ptr->name2);
1449 	} else if (acl_type == TOMOYO_TYPE_PATH_NUMBER_ACL) {
1450 		struct tomoyo_path_number_acl *ptr =
1451 			container_of(acl, typeof(*ptr), head);
1452 		const u8 perm = ptr->perm;
1453 
1454 		for (bit = 0; bit < TOMOYO_MAX_PATH_NUMBER_OPERATION; bit++) {
1455 			if (!(perm & (1 << bit)))
1456 				continue;
1457 			if (first) {
1458 				tomoyo_set_group(head, "file ");
1459 				first = false;
1460 			} else {
1461 				tomoyo_set_slash(head);
1462 			}
1463 			tomoyo_set_string(head, tomoyo_mac_keywords
1464 					  [tomoyo_pn2mac[bit]]);
1465 		}
1466 		if (first)
1467 			return true;
1468 		tomoyo_print_name_union(head, &ptr->name);
1469 		tomoyo_print_number_union(head, &ptr->number);
1470 	} else if (acl_type == TOMOYO_TYPE_MKDEV_ACL) {
1471 		struct tomoyo_mkdev_acl *ptr =
1472 			container_of(acl, typeof(*ptr), head);
1473 		const u8 perm = ptr->perm;
1474 
1475 		for (bit = 0; bit < TOMOYO_MAX_MKDEV_OPERATION; bit++) {
1476 			if (!(perm & (1 << bit)))
1477 				continue;
1478 			if (first) {
1479 				tomoyo_set_group(head, "file ");
1480 				first = false;
1481 			} else {
1482 				tomoyo_set_slash(head);
1483 			}
1484 			tomoyo_set_string(head, tomoyo_mac_keywords
1485 					  [tomoyo_pnnn2mac[bit]]);
1486 		}
1487 		if (first)
1488 			return true;
1489 		tomoyo_print_name_union(head, &ptr->name);
1490 		tomoyo_print_number_union(head, &ptr->mode);
1491 		tomoyo_print_number_union(head, &ptr->major);
1492 		tomoyo_print_number_union(head, &ptr->minor);
1493 	} else if (acl_type == TOMOYO_TYPE_INET_ACL) {
1494 		struct tomoyo_inet_acl *ptr =
1495 			container_of(acl, typeof(*ptr), head);
1496 		const u8 perm = ptr->perm;
1497 
1498 		for (bit = 0; bit < TOMOYO_MAX_NETWORK_OPERATION; bit++) {
1499 			if (!(perm & (1 << bit)))
1500 				continue;
1501 			if (first) {
1502 				tomoyo_set_group(head, "network inet ");
1503 				tomoyo_set_string(head, tomoyo_proto_keyword
1504 						  [ptr->protocol]);
1505 				tomoyo_set_space(head);
1506 				first = false;
1507 			} else {
1508 				tomoyo_set_slash(head);
1509 			}
1510 			tomoyo_set_string(head, tomoyo_socket_keyword[bit]);
1511 		}
1512 		if (first)
1513 			return true;
1514 		tomoyo_set_space(head);
1515 		if (ptr->address.group) {
1516 			tomoyo_set_string(head, "@");
1517 			tomoyo_set_string(head, ptr->address.group->group_name
1518 					  ->name);
1519 		} else {
1520 			char buf[128];
1521 
1522 			tomoyo_print_ip(buf, sizeof(buf), &ptr->address);
1523 			tomoyo_io_printf(head, "%s", buf);
1524 		}
1525 		tomoyo_print_number_union(head, &ptr->port);
1526 	} else if (acl_type == TOMOYO_TYPE_UNIX_ACL) {
1527 		struct tomoyo_unix_acl *ptr =
1528 			container_of(acl, typeof(*ptr), head);
1529 		const u8 perm = ptr->perm;
1530 
1531 		for (bit = 0; bit < TOMOYO_MAX_NETWORK_OPERATION; bit++) {
1532 			if (!(perm & (1 << bit)))
1533 				continue;
1534 			if (first) {
1535 				tomoyo_set_group(head, "network unix ");
1536 				tomoyo_set_string(head, tomoyo_proto_keyword
1537 						  [ptr->protocol]);
1538 				tomoyo_set_space(head);
1539 				first = false;
1540 			} else {
1541 				tomoyo_set_slash(head);
1542 			}
1543 			tomoyo_set_string(head, tomoyo_socket_keyword[bit]);
1544 		}
1545 		if (first)
1546 			return true;
1547 		tomoyo_print_name_union(head, &ptr->name);
1548 	} else if (acl_type == TOMOYO_TYPE_MOUNT_ACL) {
1549 		struct tomoyo_mount_acl *ptr =
1550 			container_of(acl, typeof(*ptr), head);
1551 
1552 		tomoyo_set_group(head, "file mount");
1553 		tomoyo_print_name_union(head, &ptr->dev_name);
1554 		tomoyo_print_name_union(head, &ptr->dir_name);
1555 		tomoyo_print_name_union(head, &ptr->fs_type);
1556 		tomoyo_print_number_union(head, &ptr->flags);
1557 	} else if (acl_type == TOMOYO_TYPE_ENV_ACL) {
1558 		struct tomoyo_env_acl *ptr =
1559 			container_of(acl, typeof(*ptr), head);
1560 
1561 		tomoyo_set_group(head, "misc env ");
1562 		tomoyo_set_string(head, ptr->env->name);
1563 	}
1564 	if (acl->cond) {
1565 		head->r.print_cond_part = true;
1566 		head->r.cond_step = 0;
1567 		if (!tomoyo_flush(head))
1568 			return false;
1569 print_cond_part:
1570 		if (!tomoyo_print_condition(head, acl->cond))
1571 			return false;
1572 		head->r.print_cond_part = false;
1573 	} else {
1574 		tomoyo_set_lf(head);
1575 	}
1576 	return true;
1577 }
1578 
1579 /**
1580  * tomoyo_read_domain2 - Read domain policy.
1581  *
1582  * @head: Pointer to "struct tomoyo_io_buffer".
1583  * @list: Pointer to "struct list_head".
1584  *
1585  * Caller holds tomoyo_read_lock().
1586  *
1587  * Returns true on success, false otherwise.
1588  */
1589 static bool tomoyo_read_domain2(struct tomoyo_io_buffer *head,
1590 				struct list_head *list)
1591 {
1592 	list_for_each_cookie(head->r.acl, list) {
1593 		struct tomoyo_acl_info *ptr =
1594 			list_entry(head->r.acl, typeof(*ptr), list);
1595 
1596 		if (!tomoyo_print_entry(head, ptr))
1597 			return false;
1598 	}
1599 	head->r.acl = NULL;
1600 	return true;
1601 }
1602 
1603 /**
1604  * tomoyo_read_domain - Read domain policy.
1605  *
1606  * @head: Pointer to "struct tomoyo_io_buffer".
1607  *
1608  * Caller holds tomoyo_read_lock().
1609  */
1610 static void tomoyo_read_domain(struct tomoyo_io_buffer *head)
1611 {
1612 	if (head->r.eof)
1613 		return;
1614 	list_for_each_cookie(head->r.domain, &tomoyo_domain_list) {
1615 		struct tomoyo_domain_info *domain =
1616 			list_entry(head->r.domain, typeof(*domain), list);
1617 		u8 i;
1618 
1619 		switch (head->r.step) {
1620 		case 0:
1621 			if (domain->is_deleted &&
1622 			    !head->r.print_this_domain_only)
1623 				continue;
1624 			/* Print domainname and flags. */
1625 			tomoyo_set_string(head, domain->domainname->name);
1626 			tomoyo_set_lf(head);
1627 			tomoyo_io_printf(head, "use_profile %u\n",
1628 					 domain->profile);
1629 			for (i = 0; i < TOMOYO_MAX_DOMAIN_INFO_FLAGS; i++)
1630 				if (domain->flags[i])
1631 					tomoyo_set_string(head, tomoyo_dif[i]);
1632 			head->r.index = 0;
1633 			head->r.step++;
1634 			fallthrough;
1635 		case 1:
1636 			while (head->r.index < TOMOYO_MAX_ACL_GROUPS) {
1637 				i = head->r.index++;
1638 				if (!test_bit(i, domain->group))
1639 					continue;
1640 				tomoyo_io_printf(head, "use_group %u\n", i);
1641 				if (!tomoyo_flush(head))
1642 					return;
1643 			}
1644 			head->r.index = 0;
1645 			head->r.step++;
1646 			tomoyo_set_lf(head);
1647 			fallthrough;
1648 		case 2:
1649 			if (!tomoyo_read_domain2(head, &domain->acl_info_list))
1650 				return;
1651 			head->r.step++;
1652 			if (!tomoyo_set_lf(head))
1653 				return;
1654 			fallthrough;
1655 		case 3:
1656 			head->r.step = 0;
1657 			if (head->r.print_this_domain_only)
1658 				goto done;
1659 		}
1660 	}
1661  done:
1662 	head->r.eof = true;
1663 }
1664 
1665 /**
1666  * tomoyo_write_pid: Specify PID to obtain domainname.
1667  *
1668  * @head: Pointer to "struct tomoyo_io_buffer".
1669  *
1670  * Returns 0.
1671  */
1672 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1673 {
1674 	head->r.eof = false;
1675 	return 0;
1676 }
1677 
1678 /**
1679  * tomoyo_read_pid - Get domainname of the specified PID.
1680  *
1681  * @head: Pointer to "struct tomoyo_io_buffer".
1682  *
1683  * Returns the domainname which the specified PID is in on success,
1684  * empty string otherwise.
1685  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1686  * using read()/write() interface rather than sysctl() interface.
1687  */
1688 static void tomoyo_read_pid(struct tomoyo_io_buffer *head)
1689 {
1690 	char *buf = head->write_buf;
1691 	bool global_pid = false;
1692 	unsigned int pid;
1693 	struct task_struct *p;
1694 	struct tomoyo_domain_info *domain = NULL;
1695 
1696 	/* Accessing write_buf is safe because head->io_sem is held. */
1697 	if (!buf) {
1698 		head->r.eof = true;
1699 		return; /* Do nothing if open(O_RDONLY). */
1700 	}
1701 	if (head->r.w_pos || head->r.eof)
1702 		return;
1703 	head->r.eof = true;
1704 	if (tomoyo_str_starts(&buf, "global-pid "))
1705 		global_pid = true;
1706 	if (kstrtouint(buf, 10, &pid))
1707 		return;
1708 	rcu_read_lock();
1709 	if (global_pid)
1710 		p = find_task_by_pid_ns(pid, &init_pid_ns);
1711 	else
1712 		p = find_task_by_vpid(pid);
1713 	if (p)
1714 		domain = tomoyo_task(p)->domain_info;
1715 	rcu_read_unlock();
1716 	if (!domain)
1717 		return;
1718 	tomoyo_io_printf(head, "%u %u ", pid, domain->profile);
1719 	tomoyo_set_string(head, domain->domainname->name);
1720 }
1721 
1722 /* String table for domain transition control keywords. */
1723 static const char *tomoyo_transition_type[TOMOYO_MAX_TRANSITION_TYPE] = {
1724 	[TOMOYO_TRANSITION_CONTROL_NO_RESET]      = "no_reset_domain ",
1725 	[TOMOYO_TRANSITION_CONTROL_RESET]         = "reset_domain ",
1726 	[TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE] = "no_initialize_domain ",
1727 	[TOMOYO_TRANSITION_CONTROL_INITIALIZE]    = "initialize_domain ",
1728 	[TOMOYO_TRANSITION_CONTROL_NO_KEEP]       = "no_keep_domain ",
1729 	[TOMOYO_TRANSITION_CONTROL_KEEP]          = "keep_domain ",
1730 };
1731 
1732 /* String table for grouping keywords. */
1733 static const char *tomoyo_group_name[TOMOYO_MAX_GROUP] = {
1734 	[TOMOYO_PATH_GROUP]    = "path_group ",
1735 	[TOMOYO_NUMBER_GROUP]  = "number_group ",
1736 	[TOMOYO_ADDRESS_GROUP] = "address_group ",
1737 };
1738 
1739 /**
1740  * tomoyo_write_exception - Write exception policy.
1741  *
1742  * @head: Pointer to "struct tomoyo_io_buffer".
1743  *
1744  * Returns 0 on success, negative value otherwise.
1745  *
1746  * Caller holds tomoyo_read_lock().
1747  */
1748 static int tomoyo_write_exception(struct tomoyo_io_buffer *head)
1749 {
1750 	const bool is_delete = head->w.is_delete;
1751 	struct tomoyo_acl_param param = {
1752 		.ns = head->w.ns,
1753 		.is_delete = is_delete,
1754 		.data = head->write_buf,
1755 	};
1756 	u8 i;
1757 
1758 	if (tomoyo_str_starts(&param.data, "aggregator "))
1759 		return tomoyo_write_aggregator(&param);
1760 	for (i = 0; i < TOMOYO_MAX_TRANSITION_TYPE; i++)
1761 		if (tomoyo_str_starts(&param.data, tomoyo_transition_type[i]))
1762 			return tomoyo_write_transition_control(&param, i);
1763 	for (i = 0; i < TOMOYO_MAX_GROUP; i++)
1764 		if (tomoyo_str_starts(&param.data, tomoyo_group_name[i]))
1765 			return tomoyo_write_group(&param, i);
1766 	if (tomoyo_str_starts(&param.data, "acl_group ")) {
1767 		unsigned int group;
1768 		char *data;
1769 
1770 		group = simple_strtoul(param.data, &data, 10);
1771 		if (group < TOMOYO_MAX_ACL_GROUPS && *data++ == ' ')
1772 			return tomoyo_write_domain2
1773 				(head->w.ns, &head->w.ns->acl_group[group],
1774 				 data, is_delete);
1775 	}
1776 	return -EINVAL;
1777 }
1778 
1779 /**
1780  * tomoyo_read_group - Read "struct tomoyo_path_group"/"struct tomoyo_number_group"/"struct tomoyo_address_group" list.
1781  *
1782  * @head: Pointer to "struct tomoyo_io_buffer".
1783  * @idx:  Index number.
1784  *
1785  * Returns true on success, false otherwise.
1786  *
1787  * Caller holds tomoyo_read_lock().
1788  */
1789 static bool tomoyo_read_group(struct tomoyo_io_buffer *head, const int idx)
1790 {
1791 	struct tomoyo_policy_namespace *ns =
1792 		container_of(head->r.ns, typeof(*ns), namespace_list);
1793 	struct list_head *list = &ns->group_list[idx];
1794 
1795 	list_for_each_cookie(head->r.group, list) {
1796 		struct tomoyo_group *group =
1797 			list_entry(head->r.group, typeof(*group), head.list);
1798 
1799 		list_for_each_cookie(head->r.acl, &group->member_list) {
1800 			struct tomoyo_acl_head *ptr =
1801 				list_entry(head->r.acl, typeof(*ptr), list);
1802 
1803 			if (ptr->is_deleted)
1804 				continue;
1805 			if (!tomoyo_flush(head))
1806 				return false;
1807 			tomoyo_print_namespace(head);
1808 			tomoyo_set_string(head, tomoyo_group_name[idx]);
1809 			tomoyo_set_string(head, group->group_name->name);
1810 			if (idx == TOMOYO_PATH_GROUP) {
1811 				tomoyo_set_space(head);
1812 				tomoyo_set_string(head, container_of
1813 					       (ptr, struct tomoyo_path_group,
1814 						head)->member_name->name);
1815 			} else if (idx == TOMOYO_NUMBER_GROUP) {
1816 				tomoyo_print_number_union(head, &container_of
1817 							  (ptr,
1818 						   struct tomoyo_number_group,
1819 							   head)->number);
1820 			} else if (idx == TOMOYO_ADDRESS_GROUP) {
1821 				char buffer[128];
1822 				struct tomoyo_address_group *member =
1823 					container_of(ptr, typeof(*member),
1824 						     head);
1825 
1826 				tomoyo_print_ip(buffer, sizeof(buffer),
1827 						&member->address);
1828 				tomoyo_io_printf(head, " %s", buffer);
1829 			}
1830 			tomoyo_set_lf(head);
1831 		}
1832 		head->r.acl = NULL;
1833 	}
1834 	head->r.group = NULL;
1835 	return true;
1836 }
1837 
1838 /**
1839  * tomoyo_read_policy - Read "struct tomoyo_..._entry" list.
1840  *
1841  * @head: Pointer to "struct tomoyo_io_buffer".
1842  * @idx:  Index number.
1843  *
1844  * Returns true on success, false otherwise.
1845  *
1846  * Caller holds tomoyo_read_lock().
1847  */
1848 static bool tomoyo_read_policy(struct tomoyo_io_buffer *head, const int idx)
1849 {
1850 	struct tomoyo_policy_namespace *ns =
1851 		container_of(head->r.ns, typeof(*ns), namespace_list);
1852 	struct list_head *list = &ns->policy_list[idx];
1853 
1854 	list_for_each_cookie(head->r.acl, list) {
1855 		struct tomoyo_acl_head *acl =
1856 			container_of(head->r.acl, typeof(*acl), list);
1857 		if (acl->is_deleted)
1858 			continue;
1859 		if (!tomoyo_flush(head))
1860 			return false;
1861 		switch (idx) {
1862 		case TOMOYO_ID_TRANSITION_CONTROL:
1863 			{
1864 				struct tomoyo_transition_control *ptr =
1865 					container_of(acl, typeof(*ptr), head);
1866 
1867 				tomoyo_print_namespace(head);
1868 				tomoyo_set_string(head, tomoyo_transition_type
1869 						  [ptr->type]);
1870 				tomoyo_set_string(head, ptr->program ?
1871 						  ptr->program->name : "any");
1872 				tomoyo_set_string(head, " from ");
1873 				tomoyo_set_string(head, ptr->domainname ?
1874 						  ptr->domainname->name :
1875 						  "any");
1876 			}
1877 			break;
1878 		case TOMOYO_ID_AGGREGATOR:
1879 			{
1880 				struct tomoyo_aggregator *ptr =
1881 					container_of(acl, typeof(*ptr), head);
1882 
1883 				tomoyo_print_namespace(head);
1884 				tomoyo_set_string(head, "aggregator ");
1885 				tomoyo_set_string(head,
1886 						  ptr->original_name->name);
1887 				tomoyo_set_space(head);
1888 				tomoyo_set_string(head,
1889 					       ptr->aggregated_name->name);
1890 			}
1891 			break;
1892 		default:
1893 			continue;
1894 		}
1895 		tomoyo_set_lf(head);
1896 	}
1897 	head->r.acl = NULL;
1898 	return true;
1899 }
1900 
1901 /**
1902  * tomoyo_read_exception - Read exception policy.
1903  *
1904  * @head: Pointer to "struct tomoyo_io_buffer".
1905  *
1906  * Caller holds tomoyo_read_lock().
1907  */
1908 static void tomoyo_read_exception(struct tomoyo_io_buffer *head)
1909 {
1910 	struct tomoyo_policy_namespace *ns =
1911 		container_of(head->r.ns, typeof(*ns), namespace_list);
1912 
1913 	if (head->r.eof)
1914 		return;
1915 	while (head->r.step < TOMOYO_MAX_POLICY &&
1916 	       tomoyo_read_policy(head, head->r.step))
1917 		head->r.step++;
1918 	if (head->r.step < TOMOYO_MAX_POLICY)
1919 		return;
1920 	while (head->r.step < TOMOYO_MAX_POLICY + TOMOYO_MAX_GROUP &&
1921 	       tomoyo_read_group(head, head->r.step - TOMOYO_MAX_POLICY))
1922 		head->r.step++;
1923 	if (head->r.step < TOMOYO_MAX_POLICY + TOMOYO_MAX_GROUP)
1924 		return;
1925 	while (head->r.step < TOMOYO_MAX_POLICY + TOMOYO_MAX_GROUP
1926 	       + TOMOYO_MAX_ACL_GROUPS) {
1927 		head->r.acl_group_index = head->r.step - TOMOYO_MAX_POLICY
1928 			- TOMOYO_MAX_GROUP;
1929 		if (!tomoyo_read_domain2(head, &ns->acl_group
1930 					 [head->r.acl_group_index]))
1931 			return;
1932 		head->r.step++;
1933 	}
1934 	head->r.eof = true;
1935 }
1936 
1937 /* Wait queue for kernel -> userspace notification. */
1938 static DECLARE_WAIT_QUEUE_HEAD(tomoyo_query_wait);
1939 /* Wait queue for userspace -> kernel notification. */
1940 static DECLARE_WAIT_QUEUE_HEAD(tomoyo_answer_wait);
1941 
1942 /* Structure for query. */
1943 struct tomoyo_query {
1944 	struct list_head list;
1945 	struct tomoyo_domain_info *domain;
1946 	char *query;
1947 	size_t query_len;
1948 	unsigned int serial;
1949 	u8 timer;
1950 	u8 answer;
1951 	u8 retry;
1952 };
1953 
1954 /* The list for "struct tomoyo_query". */
1955 static LIST_HEAD(tomoyo_query_list);
1956 
1957 /* Lock for manipulating tomoyo_query_list. */
1958 static DEFINE_SPINLOCK(tomoyo_query_list_lock);
1959 
1960 /*
1961  * Number of "struct file" referring /sys/kernel/security/tomoyo/query
1962  * interface.
1963  */
1964 static atomic_t tomoyo_query_observers = ATOMIC_INIT(0);
1965 
1966 /**
1967  * tomoyo_truncate - Truncate a line.
1968  *
1969  * @str: String to truncate.
1970  *
1971  * Returns length of truncated @str.
1972  */
1973 static int tomoyo_truncate(char *str)
1974 {
1975 	char *start = str;
1976 
1977 	while (*(unsigned char *) str > (unsigned char) ' ')
1978 		str++;
1979 	*str = '\0';
1980 	return strlen(start) + 1;
1981 }
1982 
1983 /**
1984  * tomoyo_add_entry - Add an ACL to current thread's domain. Used by learning mode.
1985  *
1986  * @domain: Pointer to "struct tomoyo_domain_info".
1987  * @header: Lines containing ACL.
1988  *
1989  * Returns nothing.
1990  */
1991 static void tomoyo_add_entry(struct tomoyo_domain_info *domain, char *header)
1992 {
1993 	char *buffer;
1994 	char *realpath = NULL;
1995 	char *argv0 = NULL;
1996 	char *symlink = NULL;
1997 	char *cp = strchr(header, '\n');
1998 	int len;
1999 
2000 	if (!cp)
2001 		return;
2002 	cp = strchr(cp + 1, '\n');
2003 	if (!cp)
2004 		return;
2005 	*cp++ = '\0';
2006 	len = strlen(cp) + 1;
2007 	/* strstr() will return NULL if ordering is wrong. */
2008 	if (*cp == 'f') {
2009 		argv0 = strstr(header, " argv[]={ \"");
2010 		if (argv0) {
2011 			argv0 += 10;
2012 			len += tomoyo_truncate(argv0) + 14;
2013 		}
2014 		realpath = strstr(header, " exec={ realpath=\"");
2015 		if (realpath) {
2016 			realpath += 8;
2017 			len += tomoyo_truncate(realpath) + 6;
2018 		}
2019 		symlink = strstr(header, " symlink.target=\"");
2020 		if (symlink)
2021 			len += tomoyo_truncate(symlink + 1) + 1;
2022 	}
2023 	buffer = kmalloc(len, GFP_NOFS);
2024 	if (!buffer)
2025 		return;
2026 	snprintf(buffer, len - 1, "%s", cp);
2027 	if (realpath)
2028 		tomoyo_addprintf(buffer, len, " exec.%s", realpath);
2029 	if (argv0)
2030 		tomoyo_addprintf(buffer, len, " exec.argv[0]=%s", argv0);
2031 	if (symlink)
2032 		tomoyo_addprintf(buffer, len, "%s", symlink);
2033 	tomoyo_normalize_line(buffer);
2034 	if (!tomoyo_write_domain2(domain->ns, &domain->acl_info_list, buffer,
2035 				  false))
2036 		tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES);
2037 	kfree(buffer);
2038 }
2039 
2040 /**
2041  * tomoyo_supervisor - Ask for the supervisor's decision.
2042  *
2043  * @r:   Pointer to "struct tomoyo_request_info".
2044  * @fmt: The printf()'s format string, followed by parameters.
2045  *
2046  * Returns 0 if the supervisor decided to permit the access request which
2047  * violated the policy in enforcing mode, TOMOYO_RETRY_REQUEST if the
2048  * supervisor decided to retry the access request which violated the policy in
2049  * enforcing mode, 0 if it is not in enforcing mode, -EPERM otherwise.
2050  */
2051 int tomoyo_supervisor(struct tomoyo_request_info *r, const char *fmt, ...)
2052 {
2053 	va_list args;
2054 	int error;
2055 	int len;
2056 	static unsigned int tomoyo_serial;
2057 	struct tomoyo_query entry = { };
2058 	bool quota_exceeded = false;
2059 
2060 	va_start(args, fmt);
2061 	len = vsnprintf(NULL, 0, fmt, args) + 1;
2062 	va_end(args);
2063 	/* Write /sys/kernel/security/tomoyo/audit. */
2064 	va_start(args, fmt);
2065 	tomoyo_write_log2(r, len, fmt, args);
2066 	va_end(args);
2067 	/* Nothing more to do if granted. */
2068 	if (r->granted)
2069 		return 0;
2070 	if (r->mode)
2071 		tomoyo_update_stat(r->mode);
2072 	switch (r->mode) {
2073 	case TOMOYO_CONFIG_ENFORCING:
2074 		error = -EPERM;
2075 		if (atomic_read(&tomoyo_query_observers))
2076 			break;
2077 		goto out;
2078 	case TOMOYO_CONFIG_LEARNING:
2079 		error = 0;
2080 		/* Check max_learning_entry parameter. */
2081 		if (tomoyo_domain_quota_is_ok(r))
2082 			break;
2083 		fallthrough;
2084 	default:
2085 		return 0;
2086 	}
2087 	/* Get message. */
2088 	va_start(args, fmt);
2089 	entry.query = tomoyo_init_log(r, len, fmt, args);
2090 	va_end(args);
2091 	if (!entry.query)
2092 		goto out;
2093 	entry.query_len = strlen(entry.query) + 1;
2094 	if (!error) {
2095 		tomoyo_add_entry(r->domain, entry.query);
2096 		goto out;
2097 	}
2098 	len = kmalloc_size_roundup(entry.query_len);
2099 	entry.domain = r->domain;
2100 	spin_lock(&tomoyo_query_list_lock);
2101 	if (tomoyo_memory_quota[TOMOYO_MEMORY_QUERY] &&
2102 	    tomoyo_memory_used[TOMOYO_MEMORY_QUERY] + len
2103 	    >= tomoyo_memory_quota[TOMOYO_MEMORY_QUERY]) {
2104 		quota_exceeded = true;
2105 	} else {
2106 		entry.serial = tomoyo_serial++;
2107 		entry.retry = r->retry;
2108 		tomoyo_memory_used[TOMOYO_MEMORY_QUERY] += len;
2109 		list_add_tail(&entry.list, &tomoyo_query_list);
2110 	}
2111 	spin_unlock(&tomoyo_query_list_lock);
2112 	if (quota_exceeded)
2113 		goto out;
2114 	/* Give 10 seconds for supervisor's opinion. */
2115 	while (entry.timer < 10) {
2116 		wake_up_all(&tomoyo_query_wait);
2117 		if (wait_event_interruptible_timeout
2118 		    (tomoyo_answer_wait, entry.answer ||
2119 		     !atomic_read(&tomoyo_query_observers), HZ))
2120 			break;
2121 		entry.timer++;
2122 	}
2123 	spin_lock(&tomoyo_query_list_lock);
2124 	list_del(&entry.list);
2125 	tomoyo_memory_used[TOMOYO_MEMORY_QUERY] -= len;
2126 	spin_unlock(&tomoyo_query_list_lock);
2127 	switch (entry.answer) {
2128 	case 3: /* Asked to retry by administrator. */
2129 		error = TOMOYO_RETRY_REQUEST;
2130 		r->retry++;
2131 		break;
2132 	case 1:
2133 		/* Granted by administrator. */
2134 		error = 0;
2135 		break;
2136 	default:
2137 		/* Timed out or rejected by administrator. */
2138 		break;
2139 	}
2140 out:
2141 	kfree(entry.query);
2142 	return error;
2143 }
2144 
2145 /**
2146  * tomoyo_find_domain_by_qid - Get domain by query id.
2147  *
2148  * @serial: Query ID assigned by tomoyo_supervisor().
2149  *
2150  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
2151  */
2152 static struct tomoyo_domain_info *tomoyo_find_domain_by_qid
2153 (unsigned int serial)
2154 {
2155 	struct tomoyo_query *ptr;
2156 	struct tomoyo_domain_info *domain = NULL;
2157 
2158 	spin_lock(&tomoyo_query_list_lock);
2159 	list_for_each_entry(ptr, &tomoyo_query_list, list) {
2160 		if (ptr->serial != serial)
2161 			continue;
2162 		domain = ptr->domain;
2163 		break;
2164 	}
2165 	spin_unlock(&tomoyo_query_list_lock);
2166 	return domain;
2167 }
2168 
2169 /**
2170  * tomoyo_poll_query - poll() for /sys/kernel/security/tomoyo/query.
2171  *
2172  * @file: Pointer to "struct file".
2173  * @wait: Pointer to "poll_table".
2174  *
2175  * Returns EPOLLIN | EPOLLRDNORM when ready to read, 0 otherwise.
2176  *
2177  * Waits for access requests which violated policy in enforcing mode.
2178  */
2179 static __poll_t tomoyo_poll_query(struct file *file, poll_table *wait)
2180 {
2181 	if (!list_empty(&tomoyo_query_list))
2182 		return EPOLLIN | EPOLLRDNORM;
2183 	poll_wait(file, &tomoyo_query_wait, wait);
2184 	if (!list_empty(&tomoyo_query_list))
2185 		return EPOLLIN | EPOLLRDNORM;
2186 	return 0;
2187 }
2188 
2189 /**
2190  * tomoyo_read_query - Read access requests which violated policy in enforcing mode.
2191  *
2192  * @head: Pointer to "struct tomoyo_io_buffer".
2193  */
2194 static void tomoyo_read_query(struct tomoyo_io_buffer *head)
2195 {
2196 	struct list_head *tmp;
2197 	unsigned int pos = 0;
2198 	size_t len = 0;
2199 	char *buf;
2200 
2201 	if (head->r.w_pos)
2202 		return;
2203 	kfree(head->read_buf);
2204 	head->read_buf = NULL;
2205 	spin_lock(&tomoyo_query_list_lock);
2206 	list_for_each(tmp, &tomoyo_query_list) {
2207 		struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
2208 
2209 		if (pos++ != head->r.query_index)
2210 			continue;
2211 		len = ptr->query_len;
2212 		break;
2213 	}
2214 	spin_unlock(&tomoyo_query_list_lock);
2215 	if (!len) {
2216 		head->r.query_index = 0;
2217 		return;
2218 	}
2219 	buf = kzalloc(len + 32, GFP_NOFS);
2220 	if (!buf)
2221 		return;
2222 	pos = 0;
2223 	spin_lock(&tomoyo_query_list_lock);
2224 	list_for_each(tmp, &tomoyo_query_list) {
2225 		struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
2226 
2227 		if (pos++ != head->r.query_index)
2228 			continue;
2229 		/*
2230 		 * Some query can be skipped because tomoyo_query_list
2231 		 * can change, but I don't care.
2232 		 */
2233 		if (len == ptr->query_len)
2234 			snprintf(buf, len + 31, "Q%u-%hu\n%s", ptr->serial,
2235 				 ptr->retry, ptr->query);
2236 		break;
2237 	}
2238 	spin_unlock(&tomoyo_query_list_lock);
2239 	if (buf[0]) {
2240 		head->read_buf = buf;
2241 		head->r.w[head->r.w_pos++] = buf;
2242 		head->r.query_index++;
2243 	} else {
2244 		kfree(buf);
2245 	}
2246 }
2247 
2248 /**
2249  * tomoyo_write_answer - Write the supervisor's decision.
2250  *
2251  * @head: Pointer to "struct tomoyo_io_buffer".
2252  *
2253  * Returns 0 on success, -EINVAL otherwise.
2254  */
2255 static int tomoyo_write_answer(struct tomoyo_io_buffer *head)
2256 {
2257 	char *data = head->write_buf;
2258 	struct list_head *tmp;
2259 	unsigned int serial;
2260 	unsigned int answer;
2261 
2262 	spin_lock(&tomoyo_query_list_lock);
2263 	list_for_each(tmp, &tomoyo_query_list) {
2264 		struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
2265 
2266 		ptr->timer = 0;
2267 	}
2268 	spin_unlock(&tomoyo_query_list_lock);
2269 	if (sscanf(data, "A%u=%u", &serial, &answer) != 2)
2270 		return -EINVAL;
2271 	spin_lock(&tomoyo_query_list_lock);
2272 	list_for_each(tmp, &tomoyo_query_list) {
2273 		struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
2274 
2275 		if (ptr->serial != serial)
2276 			continue;
2277 		ptr->answer = answer;
2278 		/* Remove from tomoyo_query_list. */
2279 		if (ptr->answer)
2280 			list_del_init(&ptr->list);
2281 		break;
2282 	}
2283 	spin_unlock(&tomoyo_query_list_lock);
2284 	return 0;
2285 }
2286 
2287 /**
2288  * tomoyo_read_version: Get version.
2289  *
2290  * @head: Pointer to "struct tomoyo_io_buffer".
2291  *
2292  * Returns version information.
2293  */
2294 static void tomoyo_read_version(struct tomoyo_io_buffer *head)
2295 {
2296 	if (!head->r.eof) {
2297 		tomoyo_io_printf(head, "2.6.0");
2298 		head->r.eof = true;
2299 	}
2300 }
2301 
2302 /* String table for /sys/kernel/security/tomoyo/stat interface. */
2303 static const char * const tomoyo_policy_headers[TOMOYO_MAX_POLICY_STAT] = {
2304 	[TOMOYO_STAT_POLICY_UPDATES]    = "update:",
2305 	[TOMOYO_STAT_POLICY_LEARNING]   = "violation in learning mode:",
2306 	[TOMOYO_STAT_POLICY_PERMISSIVE] = "violation in permissive mode:",
2307 	[TOMOYO_STAT_POLICY_ENFORCING]  = "violation in enforcing mode:",
2308 };
2309 
2310 /* String table for /sys/kernel/security/tomoyo/stat interface. */
2311 static const char * const tomoyo_memory_headers[TOMOYO_MAX_MEMORY_STAT] = {
2312 	[TOMOYO_MEMORY_POLICY] = "policy:",
2313 	[TOMOYO_MEMORY_AUDIT]  = "audit log:",
2314 	[TOMOYO_MEMORY_QUERY]  = "query message:",
2315 };
2316 
2317 /* Counter for number of updates. */
2318 static atomic_t tomoyo_stat_updated[TOMOYO_MAX_POLICY_STAT];
2319 /* Timestamp counter for last updated. */
2320 static time64_t tomoyo_stat_modified[TOMOYO_MAX_POLICY_STAT];
2321 
2322 /**
2323  * tomoyo_update_stat - Update statistic counters.
2324  *
2325  * @index: Index for policy type.
2326  *
2327  * Returns nothing.
2328  */
2329 void tomoyo_update_stat(const u8 index)
2330 {
2331 	atomic_inc(&tomoyo_stat_updated[index]);
2332 	tomoyo_stat_modified[index] = ktime_get_real_seconds();
2333 }
2334 
2335 /**
2336  * tomoyo_read_stat - Read statistic data.
2337  *
2338  * @head: Pointer to "struct tomoyo_io_buffer".
2339  *
2340  * Returns nothing.
2341  */
2342 static void tomoyo_read_stat(struct tomoyo_io_buffer *head)
2343 {
2344 	u8 i;
2345 	unsigned int total = 0;
2346 
2347 	if (head->r.eof)
2348 		return;
2349 	for (i = 0; i < TOMOYO_MAX_POLICY_STAT; i++) {
2350 		tomoyo_io_printf(head, "Policy %-30s %10u",
2351 				 tomoyo_policy_headers[i],
2352 				 atomic_read(&tomoyo_stat_updated[i]));
2353 		if (tomoyo_stat_modified[i]) {
2354 			struct tomoyo_time stamp;
2355 
2356 			tomoyo_convert_time(tomoyo_stat_modified[i], &stamp);
2357 			tomoyo_io_printf(head, " (Last: %04u/%02u/%02u %02u:%02u:%02u)",
2358 					 stamp.year, stamp.month, stamp.day,
2359 					 stamp.hour, stamp.min, stamp.sec);
2360 		}
2361 		tomoyo_set_lf(head);
2362 	}
2363 	for (i = 0; i < TOMOYO_MAX_MEMORY_STAT; i++) {
2364 		unsigned int used = tomoyo_memory_used[i];
2365 
2366 		total += used;
2367 		tomoyo_io_printf(head, "Memory used by %-22s %10u",
2368 				 tomoyo_memory_headers[i], used);
2369 		used = tomoyo_memory_quota[i];
2370 		if (used)
2371 			tomoyo_io_printf(head, " (Quota: %10u)", used);
2372 		tomoyo_set_lf(head);
2373 	}
2374 	tomoyo_io_printf(head, "Total memory used:                    %10u\n",
2375 			 total);
2376 	head->r.eof = true;
2377 }
2378 
2379 /**
2380  * tomoyo_write_stat - Set memory quota.
2381  *
2382  * @head: Pointer to "struct tomoyo_io_buffer".
2383  *
2384  * Returns 0.
2385  */
2386 static int tomoyo_write_stat(struct tomoyo_io_buffer *head)
2387 {
2388 	char *data = head->write_buf;
2389 	u8 i;
2390 
2391 	if (tomoyo_str_starts(&data, "Memory used by "))
2392 		for (i = 0; i < TOMOYO_MAX_MEMORY_STAT; i++)
2393 			if (tomoyo_str_starts(&data, tomoyo_memory_headers[i]))
2394 				sscanf(data, "%u", &tomoyo_memory_quota[i]);
2395 	return 0;
2396 }
2397 
2398 /**
2399  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
2400  *
2401  * @type: Type of interface.
2402  * @file: Pointer to "struct file".
2403  *
2404  * Returns 0 on success, negative value otherwise.
2405  */
2406 int tomoyo_open_control(const u8 type, struct file *file)
2407 {
2408 	struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_NOFS);
2409 
2410 	if (!head)
2411 		return -ENOMEM;
2412 	mutex_init(&head->io_sem);
2413 	head->type = type;
2414 	switch (type) {
2415 	case TOMOYO_DOMAINPOLICY:
2416 		/* /sys/kernel/security/tomoyo/domain_policy */
2417 		head->write = tomoyo_write_domain;
2418 		head->read = tomoyo_read_domain;
2419 		break;
2420 	case TOMOYO_EXCEPTIONPOLICY:
2421 		/* /sys/kernel/security/tomoyo/exception_policy */
2422 		head->write = tomoyo_write_exception;
2423 		head->read = tomoyo_read_exception;
2424 		break;
2425 	case TOMOYO_AUDIT:
2426 		/* /sys/kernel/security/tomoyo/audit */
2427 		head->poll = tomoyo_poll_log;
2428 		head->read = tomoyo_read_log;
2429 		break;
2430 	case TOMOYO_PROCESS_STATUS:
2431 		/* /sys/kernel/security/tomoyo/.process_status */
2432 		head->write = tomoyo_write_pid;
2433 		head->read = tomoyo_read_pid;
2434 		break;
2435 	case TOMOYO_VERSION:
2436 		/* /sys/kernel/security/tomoyo/version */
2437 		head->read = tomoyo_read_version;
2438 		head->readbuf_size = 128;
2439 		break;
2440 	case TOMOYO_STAT:
2441 		/* /sys/kernel/security/tomoyo/stat */
2442 		head->write = tomoyo_write_stat;
2443 		head->read = tomoyo_read_stat;
2444 		head->readbuf_size = 1024;
2445 		break;
2446 	case TOMOYO_PROFILE:
2447 		/* /sys/kernel/security/tomoyo/profile */
2448 		head->write = tomoyo_write_profile;
2449 		head->read = tomoyo_read_profile;
2450 		break;
2451 	case TOMOYO_QUERY: /* /sys/kernel/security/tomoyo/query */
2452 		head->poll = tomoyo_poll_query;
2453 		head->write = tomoyo_write_answer;
2454 		head->read = tomoyo_read_query;
2455 		break;
2456 	case TOMOYO_MANAGER:
2457 		/* /sys/kernel/security/tomoyo/manager */
2458 		head->write = tomoyo_write_manager;
2459 		head->read = tomoyo_read_manager;
2460 		break;
2461 	}
2462 	if (!(file->f_mode & FMODE_READ)) {
2463 		/*
2464 		 * No need to allocate read_buf since it is not opened
2465 		 * for reading.
2466 		 */
2467 		head->read = NULL;
2468 		head->poll = NULL;
2469 	} else if (!head->poll) {
2470 		/* Don't allocate read_buf for poll() access. */
2471 		if (!head->readbuf_size)
2472 			head->readbuf_size = 4096 * 2;
2473 		head->read_buf = kzalloc(head->readbuf_size, GFP_NOFS);
2474 		if (!head->read_buf) {
2475 			kfree(head);
2476 			return -ENOMEM;
2477 		}
2478 	}
2479 	if (!(file->f_mode & FMODE_WRITE)) {
2480 		/*
2481 		 * No need to allocate write_buf since it is not opened
2482 		 * for writing.
2483 		 */
2484 		head->write = NULL;
2485 	} else if (head->write) {
2486 		head->writebuf_size = 4096 * 2;
2487 		head->write_buf = kzalloc(head->writebuf_size, GFP_NOFS);
2488 		if (!head->write_buf) {
2489 			kfree(head->read_buf);
2490 			kfree(head);
2491 			return -ENOMEM;
2492 		}
2493 	}
2494 	/*
2495 	 * If the file is /sys/kernel/security/tomoyo/query , increment the
2496 	 * observer counter.
2497 	 * The obserber counter is used by tomoyo_supervisor() to see if
2498 	 * there is some process monitoring /sys/kernel/security/tomoyo/query.
2499 	 */
2500 	if (type == TOMOYO_QUERY)
2501 		atomic_inc(&tomoyo_query_observers);
2502 	file->private_data = head;
2503 	tomoyo_notify_gc(head, true);
2504 	return 0;
2505 }
2506 
2507 /**
2508  * tomoyo_poll_control - poll() for /sys/kernel/security/tomoyo/ interface.
2509  *
2510  * @file: Pointer to "struct file".
2511  * @wait: Pointer to "poll_table". Maybe NULL.
2512  *
2513  * Returns EPOLLIN | EPOLLRDNORM | EPOLLOUT | EPOLLWRNORM if ready to read/write,
2514  * EPOLLOUT | EPOLLWRNORM otherwise.
2515  */
2516 __poll_t tomoyo_poll_control(struct file *file, poll_table *wait)
2517 {
2518 	struct tomoyo_io_buffer *head = file->private_data;
2519 
2520 	if (head->poll)
2521 		return head->poll(file, wait) | EPOLLOUT | EPOLLWRNORM;
2522 	return EPOLLIN | EPOLLRDNORM | EPOLLOUT | EPOLLWRNORM;
2523 }
2524 
2525 /**
2526  * tomoyo_set_namespace_cursor - Set namespace to read.
2527  *
2528  * @head: Pointer to "struct tomoyo_io_buffer".
2529  *
2530  * Returns nothing.
2531  */
2532 static inline void tomoyo_set_namespace_cursor(struct tomoyo_io_buffer *head)
2533 {
2534 	struct list_head *ns;
2535 
2536 	if (head->type != TOMOYO_EXCEPTIONPOLICY &&
2537 	    head->type != TOMOYO_PROFILE)
2538 		return;
2539 	/*
2540 	 * If this is the first read, or reading previous namespace finished
2541 	 * and has more namespaces to read, update the namespace cursor.
2542 	 */
2543 	ns = head->r.ns;
2544 	if (!ns || (head->r.eof && ns->next != &tomoyo_namespace_list)) {
2545 		/* Clearing is OK because tomoyo_flush() returned true. */
2546 		memset(&head->r, 0, sizeof(head->r));
2547 		head->r.ns = ns ? ns->next : tomoyo_namespace_list.next;
2548 	}
2549 }
2550 
2551 /**
2552  * tomoyo_has_more_namespace - Check for unread namespaces.
2553  *
2554  * @head: Pointer to "struct tomoyo_io_buffer".
2555  *
2556  * Returns true if we have more entries to print, false otherwise.
2557  */
2558 static inline bool tomoyo_has_more_namespace(struct tomoyo_io_buffer *head)
2559 {
2560 	return (head->type == TOMOYO_EXCEPTIONPOLICY ||
2561 		head->type == TOMOYO_PROFILE) && head->r.eof &&
2562 		head->r.ns->next != &tomoyo_namespace_list;
2563 }
2564 
2565 /**
2566  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
2567  *
2568  * @head:       Pointer to "struct tomoyo_io_buffer".
2569  * @buffer:     Pointer to buffer to write to.
2570  * @buffer_len: Size of @buffer.
2571  *
2572  * Returns bytes read on success, negative value otherwise.
2573  */
2574 ssize_t tomoyo_read_control(struct tomoyo_io_buffer *head, char __user *buffer,
2575 			    const int buffer_len)
2576 {
2577 	int len;
2578 	int idx;
2579 
2580 	if (!head->read)
2581 		return -EINVAL;
2582 	if (mutex_lock_interruptible(&head->io_sem))
2583 		return -EINTR;
2584 	head->read_user_buf = buffer;
2585 	head->read_user_buf_avail = buffer_len;
2586 	idx = tomoyo_read_lock();
2587 	if (tomoyo_flush(head))
2588 		/* Call the policy handler. */
2589 		do {
2590 			tomoyo_set_namespace_cursor(head);
2591 			head->read(head);
2592 		} while (tomoyo_flush(head) &&
2593 			 tomoyo_has_more_namespace(head));
2594 	tomoyo_read_unlock(idx);
2595 	len = head->read_user_buf - buffer;
2596 	mutex_unlock(&head->io_sem);
2597 	return len;
2598 }
2599 
2600 /**
2601  * tomoyo_parse_policy - Parse a policy line.
2602  *
2603  * @head: Pointer to "struct tomoyo_io_buffer".
2604  * @line: Line to parse.
2605  *
2606  * Returns 0 on success, negative value otherwise.
2607  *
2608  * Caller holds tomoyo_read_lock().
2609  */
2610 static int tomoyo_parse_policy(struct tomoyo_io_buffer *head, char *line)
2611 {
2612 	/* Delete request? */
2613 	head->w.is_delete = !strncmp(line, "delete ", 7);
2614 	if (head->w.is_delete)
2615 		memmove(line, line + 7, strlen(line + 7) + 1);
2616 	/* Selecting namespace to update. */
2617 	if (head->type == TOMOYO_EXCEPTIONPOLICY ||
2618 	    head->type == TOMOYO_PROFILE) {
2619 		if (*line == '<') {
2620 			char *cp = strchr(line, ' ');
2621 
2622 			if (cp) {
2623 				*cp++ = '\0';
2624 				head->w.ns = tomoyo_assign_namespace(line);
2625 				memmove(line, cp, strlen(cp) + 1);
2626 			} else
2627 				head->w.ns = NULL;
2628 		} else
2629 			head->w.ns = &tomoyo_kernel_namespace;
2630 		/* Don't allow updating if namespace is invalid. */
2631 		if (!head->w.ns)
2632 			return -ENOENT;
2633 	}
2634 	/* Do the update. */
2635 	return head->write(head);
2636 }
2637 
2638 /**
2639  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
2640  *
2641  * @head:       Pointer to "struct tomoyo_io_buffer".
2642  * @buffer:     Pointer to buffer to read from.
2643  * @buffer_len: Size of @buffer.
2644  *
2645  * Returns @buffer_len on success, negative value otherwise.
2646  */
2647 ssize_t tomoyo_write_control(struct tomoyo_io_buffer *head,
2648 			     const char __user *buffer, const int buffer_len)
2649 {
2650 	int error = buffer_len;
2651 	size_t avail_len = buffer_len;
2652 	char *cp0 = head->write_buf;
2653 	int idx;
2654 
2655 	if (!head->write)
2656 		return -EINVAL;
2657 	if (mutex_lock_interruptible(&head->io_sem))
2658 		return -EINTR;
2659 	head->read_user_buf_avail = 0;
2660 	idx = tomoyo_read_lock();
2661 	/* Read a line and dispatch it to the policy handler. */
2662 	while (avail_len > 0) {
2663 		char c;
2664 
2665 		if (head->w.avail >= head->writebuf_size - 1) {
2666 			const int len = head->writebuf_size * 2;
2667 			char *cp = kzalloc(len, GFP_NOFS);
2668 
2669 			if (!cp) {
2670 				error = -ENOMEM;
2671 				break;
2672 			}
2673 			memmove(cp, cp0, head->w.avail);
2674 			kfree(cp0);
2675 			head->write_buf = cp;
2676 			cp0 = cp;
2677 			head->writebuf_size = len;
2678 		}
2679 		if (get_user(c, buffer)) {
2680 			error = -EFAULT;
2681 			break;
2682 		}
2683 		buffer++;
2684 		avail_len--;
2685 		cp0[head->w.avail++] = c;
2686 		if (c != '\n')
2687 			continue;
2688 		cp0[head->w.avail - 1] = '\0';
2689 		head->w.avail = 0;
2690 		tomoyo_normalize_line(cp0);
2691 		if (!strcmp(cp0, "reset")) {
2692 			head->w.ns = &tomoyo_kernel_namespace;
2693 			head->w.domain = NULL;
2694 			memset(&head->r, 0, sizeof(head->r));
2695 			continue;
2696 		}
2697 		/* Don't allow updating policies by non manager programs. */
2698 		switch (head->type) {
2699 		case TOMOYO_PROCESS_STATUS:
2700 			/* This does not write anything. */
2701 			break;
2702 		case TOMOYO_DOMAINPOLICY:
2703 			if (tomoyo_select_domain(head, cp0))
2704 				continue;
2705 			fallthrough;
2706 		case TOMOYO_EXCEPTIONPOLICY:
2707 			if (!strcmp(cp0, "select transition_only")) {
2708 				head->r.print_transition_related_only = true;
2709 				continue;
2710 			}
2711 			fallthrough;
2712 		default:
2713 			if (!tomoyo_manager()) {
2714 				error = -EPERM;
2715 				goto out;
2716 			}
2717 		}
2718 		switch (tomoyo_parse_policy(head, cp0)) {
2719 		case -EPERM:
2720 			error = -EPERM;
2721 			goto out;
2722 		case 0:
2723 			switch (head->type) {
2724 			case TOMOYO_DOMAINPOLICY:
2725 			case TOMOYO_EXCEPTIONPOLICY:
2726 			case TOMOYO_STAT:
2727 			case TOMOYO_PROFILE:
2728 			case TOMOYO_MANAGER:
2729 				tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES);
2730 				break;
2731 			default:
2732 				break;
2733 			}
2734 			break;
2735 		}
2736 	}
2737 out:
2738 	tomoyo_read_unlock(idx);
2739 	mutex_unlock(&head->io_sem);
2740 	return error;
2741 }
2742 
2743 /**
2744  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2745  *
2746  * @head: Pointer to "struct tomoyo_io_buffer".
2747  */
2748 void tomoyo_close_control(struct tomoyo_io_buffer *head)
2749 {
2750 	/*
2751 	 * If the file is /sys/kernel/security/tomoyo/query , decrement the
2752 	 * observer counter.
2753 	 */
2754 	if (head->type == TOMOYO_QUERY &&
2755 	    atomic_dec_and_test(&tomoyo_query_observers))
2756 		wake_up_all(&tomoyo_answer_wait);
2757 	tomoyo_notify_gc(head, false);
2758 }
2759 
2760 /**
2761  * tomoyo_check_profile - Check all profiles currently assigned to domains are defined.
2762  */
2763 void tomoyo_check_profile(void)
2764 {
2765 	struct tomoyo_domain_info *domain;
2766 	const int idx = tomoyo_read_lock();
2767 
2768 	tomoyo_policy_loaded = true;
2769 	pr_info("TOMOYO: 2.6.0\n");
2770 	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list,
2771 				srcu_read_lock_held(&tomoyo_ss)) {
2772 		const u8 profile = domain->profile;
2773 		struct tomoyo_policy_namespace *ns = domain->ns;
2774 
2775 		if (ns->profile_version == 20110903) {
2776 			pr_info_once("Converting profile version from %u to %u.\n",
2777 				     20110903, 20150505);
2778 			ns->profile_version = 20150505;
2779 		}
2780 		if (ns->profile_version != 20150505)
2781 			pr_err("Profile version %u is not supported.\n",
2782 			       ns->profile_version);
2783 		else if (!ns->profile_ptr[profile])
2784 			pr_err("Profile %u (used by '%s') is not defined.\n",
2785 			       profile, domain->domainname->name);
2786 		else
2787 			continue;
2788 		pr_err("Userland tools for TOMOYO 2.6 must be installed and policy must be initialized.\n");
2789 		pr_err("Please see https://tomoyo.osdn.jp/2.6/ for more information.\n");
2790 		panic("STOP!");
2791 	}
2792 	tomoyo_read_unlock(idx);
2793 	pr_info("Mandatory Access Control activated.\n");
2794 }
2795 
2796 /**
2797  * tomoyo_load_builtin_policy - Load built-in policy.
2798  *
2799  * Returns nothing.
2800  */
2801 void __init tomoyo_load_builtin_policy(void)
2802 {
2803 #ifdef CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING
2804 	static char tomoyo_builtin_profile[] __initdata =
2805 		"PROFILE_VERSION=20150505\n"
2806 		"0-CONFIG={ mode=learning grant_log=no reject_log=yes }\n";
2807 	static char tomoyo_builtin_exception_policy[] __initdata =
2808 		"aggregator proc:/self/exe /proc/self/exe\n";
2809 	static char tomoyo_builtin_domain_policy[] __initdata = "";
2810 	static char tomoyo_builtin_manager[] __initdata = "";
2811 	static char tomoyo_builtin_stat[] __initdata = "";
2812 #else
2813 	/*
2814 	 * This include file is manually created and contains built-in policy
2815 	 * named "tomoyo_builtin_profile", "tomoyo_builtin_exception_policy",
2816 	 * "tomoyo_builtin_domain_policy", "tomoyo_builtin_manager",
2817 	 * "tomoyo_builtin_stat" in the form of "static char [] __initdata".
2818 	 */
2819 #include "builtin-policy.h"
2820 #endif
2821 	u8 i;
2822 	const int idx = tomoyo_read_lock();
2823 
2824 	for (i = 0; i < 5; i++) {
2825 		struct tomoyo_io_buffer head = { };
2826 		char *start = "";
2827 
2828 		switch (i) {
2829 		case 0:
2830 			start = tomoyo_builtin_profile;
2831 			head.type = TOMOYO_PROFILE;
2832 			head.write = tomoyo_write_profile;
2833 			break;
2834 		case 1:
2835 			start = tomoyo_builtin_exception_policy;
2836 			head.type = TOMOYO_EXCEPTIONPOLICY;
2837 			head.write = tomoyo_write_exception;
2838 			break;
2839 		case 2:
2840 			start = tomoyo_builtin_domain_policy;
2841 			head.type = TOMOYO_DOMAINPOLICY;
2842 			head.write = tomoyo_write_domain;
2843 			break;
2844 		case 3:
2845 			start = tomoyo_builtin_manager;
2846 			head.type = TOMOYO_MANAGER;
2847 			head.write = tomoyo_write_manager;
2848 			break;
2849 		case 4:
2850 			start = tomoyo_builtin_stat;
2851 			head.type = TOMOYO_STAT;
2852 			head.write = tomoyo_write_stat;
2853 			break;
2854 		}
2855 		while (1) {
2856 			char *end = strchr(start, '\n');
2857 
2858 			if (!end)
2859 				break;
2860 			*end = '\0';
2861 			tomoyo_normalize_line(start);
2862 			head.write_buf = start;
2863 			tomoyo_parse_policy(&head, start);
2864 			start = end + 1;
2865 		}
2866 	}
2867 	tomoyo_read_unlock(idx);
2868 #ifdef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
2869 	tomoyo_check_profile();
2870 #endif
2871 }
2872