xref: /openbmc/linux/security/tomoyo/network.c (revision 37744fee)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * security/tomoyo/network.c
4  *
5  * Copyright (C) 2005-2011  NTT DATA CORPORATION
6  */
7 
8 #include "common.h"
9 #include <linux/slab.h>
10 
11 /* Structure for holding inet domain socket's address. */
12 struct tomoyo_inet_addr_info {
13 	__be16 port;           /* In network byte order. */
14 	const __be32 *address; /* In network byte order. */
15 	bool is_ipv6;
16 };
17 
18 /* Structure for holding unix domain socket's address. */
19 struct tomoyo_unix_addr_info {
20 	u8 *addr; /* This may not be '\0' terminated string. */
21 	unsigned int addr_len;
22 };
23 
24 /* Structure for holding socket address. */
25 struct tomoyo_addr_info {
26 	u8 protocol;
27 	u8 operation;
28 	struct tomoyo_inet_addr_info inet;
29 	struct tomoyo_unix_addr_info unix0;
30 };
31 
32 /* String table for socket's protocols. */
33 const char * const tomoyo_proto_keyword[TOMOYO_SOCK_MAX] = {
34 	[SOCK_STREAM]    = "stream",
35 	[SOCK_DGRAM]     = "dgram",
36 	[SOCK_RAW]       = "raw",
37 	[SOCK_SEQPACKET] = "seqpacket",
38 	[0] = " ", /* Dummy for avoiding NULL pointer dereference. */
39 	[4] = " ", /* Dummy for avoiding NULL pointer dereference. */
40 };
41 
42 /**
43  * tomoyo_parse_ipaddr_union - Parse an IP address.
44  *
45  * @param: Pointer to "struct tomoyo_acl_param".
46  * @ptr:   Pointer to "struct tomoyo_ipaddr_union".
47  *
48  * Returns true on success, false otherwise.
49  */
50 bool tomoyo_parse_ipaddr_union(struct tomoyo_acl_param *param,
51 			       struct tomoyo_ipaddr_union *ptr)
52 {
53 	u8 * const min = ptr->ip[0].in6_u.u6_addr8;
54 	u8 * const max = ptr->ip[1].in6_u.u6_addr8;
55 	char *address = tomoyo_read_token(param);
56 	const char *end;
57 
58 	if (!strchr(address, ':') &&
59 	    in4_pton(address, -1, min, '-', &end) > 0) {
60 		ptr->is_ipv6 = false;
61 		if (!*end)
62 			ptr->ip[1].s6_addr32[0] = ptr->ip[0].s6_addr32[0];
63 		else if (*end++ != '-' ||
64 			 in4_pton(end, -1, max, '\0', &end) <= 0 || *end)
65 			return false;
66 		return true;
67 	}
68 	if (in6_pton(address, -1, min, '-', &end) > 0) {
69 		ptr->is_ipv6 = true;
70 		if (!*end)
71 			memmove(max, min, sizeof(u16) * 8);
72 		else if (*end++ != '-' ||
73 			 in6_pton(end, -1, max, '\0', &end) <= 0 || *end)
74 			return false;
75 		return true;
76 	}
77 	return false;
78 }
79 
80 /**
81  * tomoyo_print_ipv4 - Print an IPv4 address.
82  *
83  * @buffer:     Buffer to write to.
84  * @buffer_len: Size of @buffer.
85  * @min_ip:     Pointer to __be32.
86  * @max_ip:     Pointer to __be32.
87  *
88  * Returns nothing.
89  */
90 static void tomoyo_print_ipv4(char *buffer, const unsigned int buffer_len,
91 			      const __be32 *min_ip, const __be32 *max_ip)
92 {
93 	snprintf(buffer, buffer_len, "%pI4%c%pI4", min_ip,
94 		 *min_ip == *max_ip ? '\0' : '-', max_ip);
95 }
96 
97 /**
98  * tomoyo_print_ipv6 - Print an IPv6 address.
99  *
100  * @buffer:     Buffer to write to.
101  * @buffer_len: Size of @buffer.
102  * @min_ip:     Pointer to "struct in6_addr".
103  * @max_ip:     Pointer to "struct in6_addr".
104  *
105  * Returns nothing.
106  */
107 static void tomoyo_print_ipv6(char *buffer, const unsigned int buffer_len,
108 			      const struct in6_addr *min_ip,
109 			      const struct in6_addr *max_ip)
110 {
111 	snprintf(buffer, buffer_len, "%pI6c%c%pI6c", min_ip,
112 		 !memcmp(min_ip, max_ip, 16) ? '\0' : '-', max_ip);
113 }
114 
115 /**
116  * tomoyo_print_ip - Print an IP address.
117  *
118  * @buf:  Buffer to write to.
119  * @size: Size of @buf.
120  * @ptr:  Pointer to "struct ipaddr_union".
121  *
122  * Returns nothing.
123  */
124 void tomoyo_print_ip(char *buf, const unsigned int size,
125 		     const struct tomoyo_ipaddr_union *ptr)
126 {
127 	if (ptr->is_ipv6)
128 		tomoyo_print_ipv6(buf, size, &ptr->ip[0], &ptr->ip[1]);
129 	else
130 		tomoyo_print_ipv4(buf, size, &ptr->ip[0].s6_addr32[0],
131 				  &ptr->ip[1].s6_addr32[0]);
132 }
133 
134 /*
135  * Mapping table from "enum tomoyo_network_acl_index" to
136  * "enum tomoyo_mac_index" for inet domain socket.
137  */
138 static const u8 tomoyo_inet2mac
139 [TOMOYO_SOCK_MAX][TOMOYO_MAX_NETWORK_OPERATION] = {
140 	[SOCK_STREAM] = {
141 		[TOMOYO_NETWORK_BIND]    = TOMOYO_MAC_NETWORK_INET_STREAM_BIND,
142 		[TOMOYO_NETWORK_LISTEN]  =
143 		TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN,
144 		[TOMOYO_NETWORK_CONNECT] =
145 		TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT,
146 	},
147 	[SOCK_DGRAM] = {
148 		[TOMOYO_NETWORK_BIND]    = TOMOYO_MAC_NETWORK_INET_DGRAM_BIND,
149 		[TOMOYO_NETWORK_SEND]    = TOMOYO_MAC_NETWORK_INET_DGRAM_SEND,
150 	},
151 	[SOCK_RAW]    = {
152 		[TOMOYO_NETWORK_BIND]    = TOMOYO_MAC_NETWORK_INET_RAW_BIND,
153 		[TOMOYO_NETWORK_SEND]    = TOMOYO_MAC_NETWORK_INET_RAW_SEND,
154 	},
155 };
156 
157 /*
158  * Mapping table from "enum tomoyo_network_acl_index" to
159  * "enum tomoyo_mac_index" for unix domain socket.
160  */
161 static const u8 tomoyo_unix2mac
162 [TOMOYO_SOCK_MAX][TOMOYO_MAX_NETWORK_OPERATION] = {
163 	[SOCK_STREAM] = {
164 		[TOMOYO_NETWORK_BIND]    = TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND,
165 		[TOMOYO_NETWORK_LISTEN]  =
166 		TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN,
167 		[TOMOYO_NETWORK_CONNECT] =
168 		TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT,
169 	},
170 	[SOCK_DGRAM] = {
171 		[TOMOYO_NETWORK_BIND]    = TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND,
172 		[TOMOYO_NETWORK_SEND]    = TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND,
173 	},
174 	[SOCK_SEQPACKET] = {
175 		[TOMOYO_NETWORK_BIND]    =
176 		TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND,
177 		[TOMOYO_NETWORK_LISTEN]  =
178 		TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN,
179 		[TOMOYO_NETWORK_CONNECT] =
180 		TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT,
181 	},
182 };
183 
184 /**
185  * tomoyo_same_inet_acl - Check for duplicated "struct tomoyo_inet_acl" entry.
186  *
187  * @a: Pointer to "struct tomoyo_acl_info".
188  * @b: Pointer to "struct tomoyo_acl_info".
189  *
190  * Returns true if @a == @b except permission bits, false otherwise.
191  */
192 static bool tomoyo_same_inet_acl(const struct tomoyo_acl_info *a,
193 				 const struct tomoyo_acl_info *b)
194 {
195 	const struct tomoyo_inet_acl *p1 = container_of(a, typeof(*p1), head);
196 	const struct tomoyo_inet_acl *p2 = container_of(b, typeof(*p2), head);
197 
198 	return p1->protocol == p2->protocol &&
199 		tomoyo_same_ipaddr_union(&p1->address, &p2->address) &&
200 		tomoyo_same_number_union(&p1->port, &p2->port);
201 }
202 
203 /**
204  * tomoyo_same_unix_acl - Check for duplicated "struct tomoyo_unix_acl" entry.
205  *
206  * @a: Pointer to "struct tomoyo_acl_info".
207  * @b: Pointer to "struct tomoyo_acl_info".
208  *
209  * Returns true if @a == @b except permission bits, false otherwise.
210  */
211 static bool tomoyo_same_unix_acl(const struct tomoyo_acl_info *a,
212 				 const struct tomoyo_acl_info *b)
213 {
214 	const struct tomoyo_unix_acl *p1 = container_of(a, typeof(*p1), head);
215 	const struct tomoyo_unix_acl *p2 = container_of(b, typeof(*p2), head);
216 
217 	return p1->protocol == p2->protocol &&
218 		tomoyo_same_name_union(&p1->name, &p2->name);
219 }
220 
221 /**
222  * tomoyo_merge_inet_acl - Merge duplicated "struct tomoyo_inet_acl" entry.
223  *
224  * @a:         Pointer to "struct tomoyo_acl_info".
225  * @b:         Pointer to "struct tomoyo_acl_info".
226  * @is_delete: True for @a &= ~@b, false for @a |= @b.
227  *
228  * Returns true if @a is empty, false otherwise.
229  */
230 static bool tomoyo_merge_inet_acl(struct tomoyo_acl_info *a,
231 				  struct tomoyo_acl_info *b,
232 				  const bool is_delete)
233 {
234 	u8 * const a_perm =
235 		&container_of(a, struct tomoyo_inet_acl, head)->perm;
236 	u8 perm = *a_perm;
237 	const u8 b_perm = container_of(b, struct tomoyo_inet_acl, head)->perm;
238 
239 	if (is_delete)
240 		perm &= ~b_perm;
241 	else
242 		perm |= b_perm;
243 	*a_perm = perm;
244 	return !perm;
245 }
246 
247 /**
248  * tomoyo_merge_unix_acl - Merge duplicated "struct tomoyo_unix_acl" entry.
249  *
250  * @a:         Pointer to "struct tomoyo_acl_info".
251  * @b:         Pointer to "struct tomoyo_acl_info".
252  * @is_delete: True for @a &= ~@b, false for @a |= @b.
253  *
254  * Returns true if @a is empty, false otherwise.
255  */
256 static bool tomoyo_merge_unix_acl(struct tomoyo_acl_info *a,
257 				  struct tomoyo_acl_info *b,
258 				  const bool is_delete)
259 {
260 	u8 * const a_perm =
261 		&container_of(a, struct tomoyo_unix_acl, head)->perm;
262 	u8 perm = *a_perm;
263 	const u8 b_perm = container_of(b, struct tomoyo_unix_acl, head)->perm;
264 
265 	if (is_delete)
266 		perm &= ~b_perm;
267 	else
268 		perm |= b_perm;
269 	*a_perm = perm;
270 	return !perm;
271 }
272 
273 /**
274  * tomoyo_write_inet_network - Write "struct tomoyo_inet_acl" list.
275  *
276  * @param: Pointer to "struct tomoyo_acl_param".
277  *
278  * Returns 0 on success, negative value otherwise.
279  *
280  * Caller holds tomoyo_read_lock().
281  */
282 int tomoyo_write_inet_network(struct tomoyo_acl_param *param)
283 {
284 	struct tomoyo_inet_acl e = { .head.type = TOMOYO_TYPE_INET_ACL };
285 	int error = -EINVAL;
286 	u8 type;
287 	const char *protocol = tomoyo_read_token(param);
288 	const char *operation = tomoyo_read_token(param);
289 
290 	for (e.protocol = 0; e.protocol < TOMOYO_SOCK_MAX; e.protocol++)
291 		if (!strcmp(protocol, tomoyo_proto_keyword[e.protocol]))
292 			break;
293 	for (type = 0; type < TOMOYO_MAX_NETWORK_OPERATION; type++)
294 		if (tomoyo_permstr(operation, tomoyo_socket_keyword[type]))
295 			e.perm |= 1 << type;
296 	if (e.protocol == TOMOYO_SOCK_MAX || !e.perm)
297 		return -EINVAL;
298 	if (param->data[0] == '@') {
299 		param->data++;
300 		e.address.group =
301 			tomoyo_get_group(param, TOMOYO_ADDRESS_GROUP);
302 		if (!e.address.group)
303 			return -ENOMEM;
304 	} else {
305 		if (!tomoyo_parse_ipaddr_union(param, &e.address))
306 			goto out;
307 	}
308 	if (!tomoyo_parse_number_union(param, &e.port) ||
309 	    e.port.values[1] > 65535)
310 		goto out;
311 	error = tomoyo_update_domain(&e.head, sizeof(e), param,
312 				     tomoyo_same_inet_acl,
313 				     tomoyo_merge_inet_acl);
314 out:
315 	tomoyo_put_group(e.address.group);
316 	tomoyo_put_number_union(&e.port);
317 	return error;
318 }
319 
320 /**
321  * tomoyo_write_unix_network - Write "struct tomoyo_unix_acl" list.
322  *
323  * @param: Pointer to "struct tomoyo_acl_param".
324  *
325  * Returns 0 on success, negative value otherwise.
326  */
327 int tomoyo_write_unix_network(struct tomoyo_acl_param *param)
328 {
329 	struct tomoyo_unix_acl e = { .head.type = TOMOYO_TYPE_UNIX_ACL };
330 	int error;
331 	u8 type;
332 	const char *protocol = tomoyo_read_token(param);
333 	const char *operation = tomoyo_read_token(param);
334 
335 	for (e.protocol = 0; e.protocol < TOMOYO_SOCK_MAX; e.protocol++)
336 		if (!strcmp(protocol, tomoyo_proto_keyword[e.protocol]))
337 			break;
338 	for (type = 0; type < TOMOYO_MAX_NETWORK_OPERATION; type++)
339 		if (tomoyo_permstr(operation, tomoyo_socket_keyword[type]))
340 			e.perm |= 1 << type;
341 	if (e.protocol == TOMOYO_SOCK_MAX || !e.perm)
342 		return -EINVAL;
343 	if (!tomoyo_parse_name_union(param, &e.name))
344 		return -EINVAL;
345 	error = tomoyo_update_domain(&e.head, sizeof(e), param,
346 				     tomoyo_same_unix_acl,
347 				     tomoyo_merge_unix_acl);
348 	tomoyo_put_name_union(&e.name);
349 	return error;
350 }
351 
352 /**
353  * tomoyo_audit_net_log - Audit network log.
354  *
355  * @r:         Pointer to "struct tomoyo_request_info".
356  * @family:    Name of socket family ("inet" or "unix").
357  * @protocol:  Name of protocol in @family.
358  * @operation: Name of socket operation.
359  * @address:   Name of address.
360  *
361  * Returns 0 on success, negative value otherwise.
362  */
363 static int tomoyo_audit_net_log(struct tomoyo_request_info *r,
364 				const char *family, const u8 protocol,
365 				const u8 operation, const char *address)
366 {
367 	return tomoyo_supervisor(r, "network %s %s %s %s\n", family,
368 				 tomoyo_proto_keyword[protocol],
369 				 tomoyo_socket_keyword[operation], address);
370 }
371 
372 /**
373  * tomoyo_audit_inet_log - Audit INET network log.
374  *
375  * @r: Pointer to "struct tomoyo_request_info".
376  *
377  * Returns 0 on success, negative value otherwise.
378  */
379 static int tomoyo_audit_inet_log(struct tomoyo_request_info *r)
380 {
381 	char buf[128];
382 	int len;
383 	const __be32 *address = r->param.inet_network.address;
384 
385 	if (r->param.inet_network.is_ipv6)
386 		tomoyo_print_ipv6(buf, sizeof(buf), (const struct in6_addr *)
387 				  address, (const struct in6_addr *) address);
388 	else
389 		tomoyo_print_ipv4(buf, sizeof(buf), address, address);
390 	len = strlen(buf);
391 	snprintf(buf + len, sizeof(buf) - len, " %u",
392 		 r->param.inet_network.port);
393 	return tomoyo_audit_net_log(r, "inet", r->param.inet_network.protocol,
394 				    r->param.inet_network.operation, buf);
395 }
396 
397 /**
398  * tomoyo_audit_unix_log - Audit UNIX network log.
399  *
400  * @r: Pointer to "struct tomoyo_request_info".
401  *
402  * Returns 0 on success, negative value otherwise.
403  */
404 static int tomoyo_audit_unix_log(struct tomoyo_request_info *r)
405 {
406 	return tomoyo_audit_net_log(r, "unix", r->param.unix_network.protocol,
407 				    r->param.unix_network.operation,
408 				    r->param.unix_network.address->name);
409 }
410 
411 /**
412  * tomoyo_check_inet_acl - Check permission for inet domain socket operation.
413  *
414  * @r:   Pointer to "struct tomoyo_request_info".
415  * @ptr: Pointer to "struct tomoyo_acl_info".
416  *
417  * Returns true if granted, false otherwise.
418  */
419 static bool tomoyo_check_inet_acl(struct tomoyo_request_info *r,
420 				  const struct tomoyo_acl_info *ptr)
421 {
422 	const struct tomoyo_inet_acl *acl =
423 		container_of(ptr, typeof(*acl), head);
424 	const u8 size = r->param.inet_network.is_ipv6 ? 16 : 4;
425 
426 	if (!(acl->perm & (1 << r->param.inet_network.operation)) ||
427 	    !tomoyo_compare_number_union(r->param.inet_network.port,
428 					 &acl->port))
429 		return false;
430 	if (acl->address.group)
431 		return tomoyo_address_matches_group
432 			(r->param.inet_network.is_ipv6,
433 			 r->param.inet_network.address, acl->address.group);
434 	return acl->address.is_ipv6 == r->param.inet_network.is_ipv6 &&
435 		memcmp(&acl->address.ip[0],
436 		       r->param.inet_network.address, size) <= 0 &&
437 		memcmp(r->param.inet_network.address,
438 		       &acl->address.ip[1], size) <= 0;
439 }
440 
441 /**
442  * tomoyo_check_unix_acl - Check permission for unix domain socket operation.
443  *
444  * @r:   Pointer to "struct tomoyo_request_info".
445  * @ptr: Pointer to "struct tomoyo_acl_info".
446  *
447  * Returns true if granted, false otherwise.
448  */
449 static bool tomoyo_check_unix_acl(struct tomoyo_request_info *r,
450 				  const struct tomoyo_acl_info *ptr)
451 {
452 	const struct tomoyo_unix_acl *acl =
453 		container_of(ptr, typeof(*acl), head);
454 
455 	return (acl->perm & (1 << r->param.unix_network.operation)) &&
456 		tomoyo_compare_name_union(r->param.unix_network.address,
457 					  &acl->name);
458 }
459 
460 /**
461  * tomoyo_inet_entry - Check permission for INET network operation.
462  *
463  * @address: Pointer to "struct tomoyo_addr_info".
464  *
465  * Returns 0 on success, negative value otherwise.
466  */
467 static int tomoyo_inet_entry(const struct tomoyo_addr_info *address)
468 {
469 	const int idx = tomoyo_read_lock();
470 	struct tomoyo_request_info r;
471 	int error = 0;
472 	const u8 type = tomoyo_inet2mac[address->protocol][address->operation];
473 
474 	if (type && tomoyo_init_request_info(&r, NULL, type)
475 	    != TOMOYO_CONFIG_DISABLED) {
476 		r.param_type = TOMOYO_TYPE_INET_ACL;
477 		r.param.inet_network.protocol = address->protocol;
478 		r.param.inet_network.operation = address->operation;
479 		r.param.inet_network.is_ipv6 = address->inet.is_ipv6;
480 		r.param.inet_network.address = address->inet.address;
481 		r.param.inet_network.port = ntohs(address->inet.port);
482 		do {
483 			tomoyo_check_acl(&r, tomoyo_check_inet_acl);
484 			error = tomoyo_audit_inet_log(&r);
485 		} while (error == TOMOYO_RETRY_REQUEST);
486 	}
487 	tomoyo_read_unlock(idx);
488 	return error;
489 }
490 
491 /**
492  * tomoyo_check_inet_address - Check permission for inet domain socket's operation.
493  *
494  * @addr:     Pointer to "struct sockaddr".
495  * @addr_len: Size of @addr.
496  * @port:     Port number.
497  * @address:  Pointer to "struct tomoyo_addr_info".
498  *
499  * Returns 0 on success, negative value otherwise.
500  */
501 static int tomoyo_check_inet_address(const struct sockaddr *addr,
502 				     const unsigned int addr_len,
503 				     const u16 port,
504 				     struct tomoyo_addr_info *address)
505 {
506 	struct tomoyo_inet_addr_info *i = &address->inet;
507 
508 	if (addr_len < offsetofend(struct sockaddr, sa_family))
509 		return 0;
510 	switch (addr->sa_family) {
511 	case AF_INET6:
512 		if (addr_len < SIN6_LEN_RFC2133)
513 			goto skip;
514 		i->is_ipv6 = true;
515 		i->address = (__be32 *)
516 			((struct sockaddr_in6 *) addr)->sin6_addr.s6_addr;
517 		i->port = ((struct sockaddr_in6 *) addr)->sin6_port;
518 		break;
519 	case AF_INET:
520 		if (addr_len < sizeof(struct sockaddr_in))
521 			goto skip;
522 		i->is_ipv6 = false;
523 		i->address = (__be32 *)
524 			&((struct sockaddr_in *) addr)->sin_addr;
525 		i->port = ((struct sockaddr_in *) addr)->sin_port;
526 		break;
527 	default:
528 		goto skip;
529 	}
530 	if (address->protocol == SOCK_RAW)
531 		i->port = htons(port);
532 	return tomoyo_inet_entry(address);
533 skip:
534 	return 0;
535 }
536 
537 /**
538  * tomoyo_unix_entry - Check permission for UNIX network operation.
539  *
540  * @address: Pointer to "struct tomoyo_addr_info".
541  *
542  * Returns 0 on success, negative value otherwise.
543  */
544 static int tomoyo_unix_entry(const struct tomoyo_addr_info *address)
545 {
546 	const int idx = tomoyo_read_lock();
547 	struct tomoyo_request_info r;
548 	int error = 0;
549 	const u8 type = tomoyo_unix2mac[address->protocol][address->operation];
550 
551 	if (type && tomoyo_init_request_info(&r, NULL, type)
552 	    != TOMOYO_CONFIG_DISABLED) {
553 		char *buf = address->unix0.addr;
554 		int len = address->unix0.addr_len - sizeof(sa_family_t);
555 
556 		if (len <= 0) {
557 			buf = "anonymous";
558 			len = 9;
559 		} else if (buf[0]) {
560 			len = strnlen(buf, len);
561 		}
562 		buf = tomoyo_encode2(buf, len);
563 		if (buf) {
564 			struct tomoyo_path_info addr;
565 
566 			addr.name = buf;
567 			tomoyo_fill_path_info(&addr);
568 			r.param_type = TOMOYO_TYPE_UNIX_ACL;
569 			r.param.unix_network.protocol = address->protocol;
570 			r.param.unix_network.operation = address->operation;
571 			r.param.unix_network.address = &addr;
572 			do {
573 				tomoyo_check_acl(&r, tomoyo_check_unix_acl);
574 				error = tomoyo_audit_unix_log(&r);
575 			} while (error == TOMOYO_RETRY_REQUEST);
576 			kfree(buf);
577 		} else
578 			error = -ENOMEM;
579 	}
580 	tomoyo_read_unlock(idx);
581 	return error;
582 }
583 
584 /**
585  * tomoyo_check_unix_address - Check permission for unix domain socket's operation.
586  *
587  * @addr:     Pointer to "struct sockaddr".
588  * @addr_len: Size of @addr.
589  * @address:  Pointer to "struct tomoyo_addr_info".
590  *
591  * Returns 0 on success, negative value otherwise.
592  */
593 static int tomoyo_check_unix_address(struct sockaddr *addr,
594 				     const unsigned int addr_len,
595 				     struct tomoyo_addr_info *address)
596 {
597 	struct tomoyo_unix_addr_info *u = &address->unix0;
598 
599 	if (addr_len < offsetofend(struct sockaddr, sa_family))
600 		return 0;
601 	if (addr->sa_family != AF_UNIX)
602 		return 0;
603 	u->addr = ((struct sockaddr_un *) addr)->sun_path;
604 	u->addr_len = addr_len;
605 	return tomoyo_unix_entry(address);
606 }
607 
608 /**
609  * tomoyo_kernel_service - Check whether I'm kernel service or not.
610  *
611  * Returns true if I'm kernel service, false otherwise.
612  */
613 static bool tomoyo_kernel_service(void)
614 {
615 	/* Nothing to do if I am a kernel service. */
616 	return uaccess_kernel();
617 }
618 
619 /**
620  * tomoyo_sock_family - Get socket's family.
621  *
622  * @sk: Pointer to "struct sock".
623  *
624  * Returns one of PF_INET, PF_INET6, PF_UNIX or 0.
625  */
626 static u8 tomoyo_sock_family(struct sock *sk)
627 {
628 	u8 family;
629 
630 	if (tomoyo_kernel_service())
631 		return 0;
632 	family = sk->sk_family;
633 	switch (family) {
634 	case PF_INET:
635 	case PF_INET6:
636 	case PF_UNIX:
637 		return family;
638 	default:
639 		return 0;
640 	}
641 }
642 
643 /**
644  * tomoyo_socket_listen_permission - Check permission for listening a socket.
645  *
646  * @sock: Pointer to "struct socket".
647  *
648  * Returns 0 on success, negative value otherwise.
649  */
650 int tomoyo_socket_listen_permission(struct socket *sock)
651 {
652 	struct tomoyo_addr_info address;
653 	const u8 family = tomoyo_sock_family(sock->sk);
654 	const unsigned int type = sock->type;
655 	struct sockaddr_storage addr;
656 	int addr_len;
657 
658 	if (!family || (type != SOCK_STREAM && type != SOCK_SEQPACKET))
659 		return 0;
660 	{
661 		const int error = sock->ops->getname(sock, (struct sockaddr *)
662 						     &addr, 0);
663 
664 		if (error < 0)
665 			return error;
666 		addr_len = error;
667 	}
668 	address.protocol = type;
669 	address.operation = TOMOYO_NETWORK_LISTEN;
670 	if (family == PF_UNIX)
671 		return tomoyo_check_unix_address((struct sockaddr *) &addr,
672 						 addr_len, &address);
673 	return tomoyo_check_inet_address((struct sockaddr *) &addr, addr_len,
674 					 0, &address);
675 }
676 
677 /**
678  * tomoyo_socket_connect_permission - Check permission for setting the remote address of a socket.
679  *
680  * @sock:     Pointer to "struct socket".
681  * @addr:     Pointer to "struct sockaddr".
682  * @addr_len: Size of @addr.
683  *
684  * Returns 0 on success, negative value otherwise.
685  */
686 int tomoyo_socket_connect_permission(struct socket *sock,
687 				     struct sockaddr *addr, int addr_len)
688 {
689 	struct tomoyo_addr_info address;
690 	const u8 family = tomoyo_sock_family(sock->sk);
691 	const unsigned int type = sock->type;
692 
693 	if (!family)
694 		return 0;
695 	address.protocol = type;
696 	switch (type) {
697 	case SOCK_DGRAM:
698 	case SOCK_RAW:
699 		address.operation = TOMOYO_NETWORK_SEND;
700 		break;
701 	case SOCK_STREAM:
702 	case SOCK_SEQPACKET:
703 		address.operation = TOMOYO_NETWORK_CONNECT;
704 		break;
705 	default:
706 		return 0;
707 	}
708 	if (family == PF_UNIX)
709 		return tomoyo_check_unix_address(addr, addr_len, &address);
710 	return tomoyo_check_inet_address(addr, addr_len, sock->sk->sk_protocol,
711 					 &address);
712 }
713 
714 /**
715  * tomoyo_socket_bind_permission - Check permission for setting the local address of a socket.
716  *
717  * @sock:     Pointer to "struct socket".
718  * @addr:     Pointer to "struct sockaddr".
719  * @addr_len: Size of @addr.
720  *
721  * Returns 0 on success, negative value otherwise.
722  */
723 int tomoyo_socket_bind_permission(struct socket *sock, struct sockaddr *addr,
724 				  int addr_len)
725 {
726 	struct tomoyo_addr_info address;
727 	const u8 family = tomoyo_sock_family(sock->sk);
728 	const unsigned int type = sock->type;
729 
730 	if (!family)
731 		return 0;
732 	switch (type) {
733 	case SOCK_STREAM:
734 	case SOCK_DGRAM:
735 	case SOCK_RAW:
736 	case SOCK_SEQPACKET:
737 		address.protocol = type;
738 		address.operation = TOMOYO_NETWORK_BIND;
739 		break;
740 	default:
741 		return 0;
742 	}
743 	if (family == PF_UNIX)
744 		return tomoyo_check_unix_address(addr, addr_len, &address);
745 	return tomoyo_check_inet_address(addr, addr_len, sock->sk->sk_protocol,
746 					 &address);
747 }
748 
749 /**
750  * tomoyo_socket_sendmsg_permission - Check permission for sending a datagram.
751  *
752  * @sock: Pointer to "struct socket".
753  * @msg:  Pointer to "struct msghdr".
754  * @size: Unused.
755  *
756  * Returns 0 on success, negative value otherwise.
757  */
758 int tomoyo_socket_sendmsg_permission(struct socket *sock, struct msghdr *msg,
759 				     int size)
760 {
761 	struct tomoyo_addr_info address;
762 	const u8 family = tomoyo_sock_family(sock->sk);
763 	const unsigned int type = sock->type;
764 
765 	if (!msg->msg_name || !family ||
766 	    (type != SOCK_DGRAM && type != SOCK_RAW))
767 		return 0;
768 	address.protocol = type;
769 	address.operation = TOMOYO_NETWORK_SEND;
770 	if (family == PF_UNIX)
771 		return tomoyo_check_unix_address((struct sockaddr *)
772 						 msg->msg_name,
773 						 msg->msg_namelen, &address);
774 	return tomoyo_check_inet_address((struct sockaddr *) msg->msg_name,
775 					 msg->msg_namelen,
776 					 sock->sk->sk_protocol, &address);
777 }
778