xref: /linux/security/tomoyo/network.c (revision d257f9bf06129613de539ea71ecea60848b662cd)
1 /*
2  * security/tomoyo/network.c
3  *
4  * Copyright (C) 2005-2011  NTT DATA CORPORATION
5  */
6 
7 #include "common.h"
8 #include <linux/slab.h>
9 
10 /* Structure for holding inet domain socket's address. */
11 struct tomoyo_inet_addr_info {
12 	__be16 port;           /* In network byte order. */
13 	const __be32 *address; /* In network byte order. */
14 	bool is_ipv6;
15 };
16 
17 /* Structure for holding unix domain socket's address. */
18 struct tomoyo_unix_addr_info {
19 	u8 *addr; /* This may not be '\0' terminated string. */
20 	unsigned int addr_len;
21 };
22 
23 /* Structure for holding socket address. */
24 struct tomoyo_addr_info {
25 	u8 protocol;
26 	u8 operation;
27 	struct tomoyo_inet_addr_info inet;
28 	struct tomoyo_unix_addr_info unix0;
29 };
30 
31 /* String table for socket's protocols. */
32 const char * const tomoyo_proto_keyword[TOMOYO_SOCK_MAX] = {
33 	[SOCK_STREAM]    = "stream",
34 	[SOCK_DGRAM]     = "dgram",
35 	[SOCK_RAW]       = "raw",
36 	[SOCK_SEQPACKET] = "seqpacket",
37 	[0] = " ", /* Dummy for avoiding NULL pointer dereference. */
38 	[4] = " ", /* Dummy for avoiding NULL pointer dereference. */
39 };
40 
41 /**
42  * tomoyo_parse_ipaddr_union - Parse an IP address.
43  *
44  * @param: Pointer to "struct tomoyo_acl_param".
45  * @ptr:   Pointer to "struct tomoyo_ipaddr_union".
46  *
47  * Returns true on success, false otherwise.
48  */
49 bool tomoyo_parse_ipaddr_union(struct tomoyo_acl_param *param,
50 			       struct tomoyo_ipaddr_union *ptr)
51 {
52 	u8 * const min = ptr->ip[0].in6_u.u6_addr8;
53 	u8 * const max = ptr->ip[1].in6_u.u6_addr8;
54 	char *address = tomoyo_read_token(param);
55 	const char *end;
56 
57 	if (!strchr(address, ':') &&
58 	    in4_pton(address, -1, min, '-', &end) > 0) {
59 		ptr->is_ipv6 = false;
60 		if (!*end)
61 			ptr->ip[1].s6_addr32[0] = ptr->ip[0].s6_addr32[0];
62 		else if (*end++ != '-' ||
63 			 in4_pton(end, -1, max, '\0', &end) <= 0 || *end)
64 			return false;
65 		return true;
66 	}
67 	if (in6_pton(address, -1, min, '-', &end) > 0) {
68 		ptr->is_ipv6 = true;
69 		if (!*end)
70 			memmove(max, min, sizeof(u16) * 8);
71 		else if (*end++ != '-' ||
72 			 in6_pton(end, -1, max, '\0', &end) <= 0 || *end)
73 			return false;
74 		return true;
75 	}
76 	return false;
77 }
78 
79 /**
80  * tomoyo_print_ipv4 - Print an IPv4 address.
81  *
82  * @buffer:     Buffer to write to.
83  * @buffer_len: Size of @buffer.
84  * @min_ip:     Pointer to __be32.
85  * @max_ip:     Pointer to __be32.
86  *
87  * Returns nothing.
88  */
89 static void tomoyo_print_ipv4(char *buffer, const unsigned int buffer_len,
90 			      const __be32 *min_ip, const __be32 *max_ip)
91 {
92 	snprintf(buffer, buffer_len, "%pI4%c%pI4", min_ip,
93 		 *min_ip == *max_ip ? '\0' : '-', max_ip);
94 }
95 
96 /**
97  * tomoyo_print_ipv6 - Print an IPv6 address.
98  *
99  * @buffer:     Buffer to write to.
100  * @buffer_len: Size of @buffer.
101  * @min_ip:     Pointer to "struct in6_addr".
102  * @max_ip:     Pointer to "struct in6_addr".
103  *
104  * Returns nothing.
105  */
106 static void tomoyo_print_ipv6(char *buffer, const unsigned int buffer_len,
107 			      const struct in6_addr *min_ip,
108 			      const struct in6_addr *max_ip)
109 {
110 	snprintf(buffer, buffer_len, "%pI6c%c%pI6c", min_ip,
111 		 !memcmp(min_ip, max_ip, 16) ? '\0' : '-', max_ip);
112 }
113 
114 /**
115  * tomoyo_print_ip - Print an IP address.
116  *
117  * @buf:  Buffer to write to.
118  * @size: Size of @buf.
119  * @ptr:  Pointer to "struct ipaddr_union".
120  *
121  * Returns nothing.
122  */
123 void tomoyo_print_ip(char *buf, const unsigned int size,
124 		     const struct tomoyo_ipaddr_union *ptr)
125 {
126 	if (ptr->is_ipv6)
127 		tomoyo_print_ipv6(buf, size, &ptr->ip[0], &ptr->ip[1]);
128 	else
129 		tomoyo_print_ipv4(buf, size, &ptr->ip[0].s6_addr32[0],
130 				  &ptr->ip[1].s6_addr32[0]);
131 }
132 
133 /*
134  * Mapping table from "enum tomoyo_network_acl_index" to
135  * "enum tomoyo_mac_index" for inet domain socket.
136  */
137 static const u8 tomoyo_inet2mac
138 [TOMOYO_SOCK_MAX][TOMOYO_MAX_NETWORK_OPERATION] = {
139 	[SOCK_STREAM] = {
140 		[TOMOYO_NETWORK_BIND]    = TOMOYO_MAC_NETWORK_INET_STREAM_BIND,
141 		[TOMOYO_NETWORK_LISTEN]  =
142 		TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN,
143 		[TOMOYO_NETWORK_CONNECT] =
144 		TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT,
145 	},
146 	[SOCK_DGRAM] = {
147 		[TOMOYO_NETWORK_BIND]    = TOMOYO_MAC_NETWORK_INET_DGRAM_BIND,
148 		[TOMOYO_NETWORK_SEND]    = TOMOYO_MAC_NETWORK_INET_DGRAM_SEND,
149 	},
150 	[SOCK_RAW]    = {
151 		[TOMOYO_NETWORK_BIND]    = TOMOYO_MAC_NETWORK_INET_RAW_BIND,
152 		[TOMOYO_NETWORK_SEND]    = TOMOYO_MAC_NETWORK_INET_RAW_SEND,
153 	},
154 };
155 
156 /*
157  * Mapping table from "enum tomoyo_network_acl_index" to
158  * "enum tomoyo_mac_index" for unix domain socket.
159  */
160 static const u8 tomoyo_unix2mac
161 [TOMOYO_SOCK_MAX][TOMOYO_MAX_NETWORK_OPERATION] = {
162 	[SOCK_STREAM] = {
163 		[TOMOYO_NETWORK_BIND]    = TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND,
164 		[TOMOYO_NETWORK_LISTEN]  =
165 		TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN,
166 		[TOMOYO_NETWORK_CONNECT] =
167 		TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT,
168 	},
169 	[SOCK_DGRAM] = {
170 		[TOMOYO_NETWORK_BIND]    = TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND,
171 		[TOMOYO_NETWORK_SEND]    = TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND,
172 	},
173 	[SOCK_SEQPACKET] = {
174 		[TOMOYO_NETWORK_BIND]    =
175 		TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND,
176 		[TOMOYO_NETWORK_LISTEN]  =
177 		TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN,
178 		[TOMOYO_NETWORK_CONNECT] =
179 		TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT,
180 	},
181 };
182 
183 /**
184  * tomoyo_same_inet_acl - Check for duplicated "struct tomoyo_inet_acl" entry.
185  *
186  * @a: Pointer to "struct tomoyo_acl_info".
187  * @b: Pointer to "struct tomoyo_acl_info".
188  *
189  * Returns true if @a == @b except permission bits, false otherwise.
190  */
191 static bool tomoyo_same_inet_acl(const struct tomoyo_acl_info *a,
192 				 const struct tomoyo_acl_info *b)
193 {
194 	const struct tomoyo_inet_acl *p1 = container_of(a, typeof(*p1), head);
195 	const struct tomoyo_inet_acl *p2 = container_of(b, typeof(*p2), head);
196 
197 	return p1->protocol == p2->protocol &&
198 		tomoyo_same_ipaddr_union(&p1->address, &p2->address) &&
199 		tomoyo_same_number_union(&p1->port, &p2->port);
200 }
201 
202 /**
203  * tomoyo_same_unix_acl - Check for duplicated "struct tomoyo_unix_acl" entry.
204  *
205  * @a: Pointer to "struct tomoyo_acl_info".
206  * @b: Pointer to "struct tomoyo_acl_info".
207  *
208  * Returns true if @a == @b except permission bits, false otherwise.
209  */
210 static bool tomoyo_same_unix_acl(const struct tomoyo_acl_info *a,
211 				 const struct tomoyo_acl_info *b)
212 {
213 	const struct tomoyo_unix_acl *p1 = container_of(a, typeof(*p1), head);
214 	const struct tomoyo_unix_acl *p2 = container_of(b, typeof(*p2), head);
215 
216 	return p1->protocol == p2->protocol &&
217 		tomoyo_same_name_union(&p1->name, &p2->name);
218 }
219 
220 /**
221  * tomoyo_merge_inet_acl - Merge duplicated "struct tomoyo_inet_acl" entry.
222  *
223  * @a:         Pointer to "struct tomoyo_acl_info".
224  * @b:         Pointer to "struct tomoyo_acl_info".
225  * @is_delete: True for @a &= ~@b, false for @a |= @b.
226  *
227  * Returns true if @a is empty, false otherwise.
228  */
229 static bool tomoyo_merge_inet_acl(struct tomoyo_acl_info *a,
230 				  struct tomoyo_acl_info *b,
231 				  const bool is_delete)
232 {
233 	u8 * const a_perm =
234 		&container_of(a, struct tomoyo_inet_acl, head)->perm;
235 	u8 perm = *a_perm;
236 	const u8 b_perm = container_of(b, struct tomoyo_inet_acl, head)->perm;
237 
238 	if (is_delete)
239 		perm &= ~b_perm;
240 	else
241 		perm |= b_perm;
242 	*a_perm = perm;
243 	return !perm;
244 }
245 
246 /**
247  * tomoyo_merge_unix_acl - Merge duplicated "struct tomoyo_unix_acl" entry.
248  *
249  * @a:         Pointer to "struct tomoyo_acl_info".
250  * @b:         Pointer to "struct tomoyo_acl_info".
251  * @is_delete: True for @a &= ~@b, false for @a |= @b.
252  *
253  * Returns true if @a is empty, false otherwise.
254  */
255 static bool tomoyo_merge_unix_acl(struct tomoyo_acl_info *a,
256 				  struct tomoyo_acl_info *b,
257 				  const bool is_delete)
258 {
259 	u8 * const a_perm =
260 		&container_of(a, struct tomoyo_unix_acl, head)->perm;
261 	u8 perm = *a_perm;
262 	const u8 b_perm = container_of(b, struct tomoyo_unix_acl, head)->perm;
263 
264 	if (is_delete)
265 		perm &= ~b_perm;
266 	else
267 		perm |= b_perm;
268 	*a_perm = perm;
269 	return !perm;
270 }
271 
272 /**
273  * tomoyo_write_inet_network - Write "struct tomoyo_inet_acl" list.
274  *
275  * @param: Pointer to "struct tomoyo_acl_param".
276  *
277  * Returns 0 on success, negative value otherwise.
278  *
279  * Caller holds tomoyo_read_lock().
280  */
281 int tomoyo_write_inet_network(struct tomoyo_acl_param *param)
282 {
283 	struct tomoyo_inet_acl e = { .head.type = TOMOYO_TYPE_INET_ACL };
284 	int error = -EINVAL;
285 	u8 type;
286 	const char *protocol = tomoyo_read_token(param);
287 	const char *operation = tomoyo_read_token(param);
288 
289 	for (e.protocol = 0; e.protocol < TOMOYO_SOCK_MAX; e.protocol++)
290 		if (!strcmp(protocol, tomoyo_proto_keyword[e.protocol]))
291 			break;
292 	for (type = 0; type < TOMOYO_MAX_NETWORK_OPERATION; type++)
293 		if (tomoyo_permstr(operation, tomoyo_socket_keyword[type]))
294 			e.perm |= 1 << type;
295 	if (e.protocol == TOMOYO_SOCK_MAX || !e.perm)
296 		return -EINVAL;
297 	if (param->data[0] == '@') {
298 		param->data++;
299 		e.address.group =
300 			tomoyo_get_group(param, TOMOYO_ADDRESS_GROUP);
301 		if (!e.address.group)
302 			return -ENOMEM;
303 	} else {
304 		if (!tomoyo_parse_ipaddr_union(param, &e.address))
305 			goto out;
306 	}
307 	if (!tomoyo_parse_number_union(param, &e.port) ||
308 	    e.port.values[1] > 65535)
309 		goto out;
310 	error = tomoyo_update_domain(&e.head, sizeof(e), param,
311 				     tomoyo_same_inet_acl,
312 				     tomoyo_merge_inet_acl);
313 out:
314 	tomoyo_put_group(e.address.group);
315 	tomoyo_put_number_union(&e.port);
316 	return error;
317 }
318 
319 /**
320  * tomoyo_write_unix_network - Write "struct tomoyo_unix_acl" list.
321  *
322  * @param: Pointer to "struct tomoyo_acl_param".
323  *
324  * Returns 0 on success, negative value otherwise.
325  */
326 int tomoyo_write_unix_network(struct tomoyo_acl_param *param)
327 {
328 	struct tomoyo_unix_acl e = { .head.type = TOMOYO_TYPE_UNIX_ACL };
329 	int error;
330 	u8 type;
331 	const char *protocol = tomoyo_read_token(param);
332 	const char *operation = tomoyo_read_token(param);
333 
334 	for (e.protocol = 0; e.protocol < TOMOYO_SOCK_MAX; e.protocol++)
335 		if (!strcmp(protocol, tomoyo_proto_keyword[e.protocol]))
336 			break;
337 	for (type = 0; type < TOMOYO_MAX_NETWORK_OPERATION; type++)
338 		if (tomoyo_permstr(operation, tomoyo_socket_keyword[type]))
339 			e.perm |= 1 << type;
340 	if (e.protocol == TOMOYO_SOCK_MAX || !e.perm)
341 		return -EINVAL;
342 	if (!tomoyo_parse_name_union(param, &e.name))
343 		return -EINVAL;
344 	error = tomoyo_update_domain(&e.head, sizeof(e), param,
345 				     tomoyo_same_unix_acl,
346 				     tomoyo_merge_unix_acl);
347 	tomoyo_put_name_union(&e.name);
348 	return error;
349 }
350 
351 /**
352  * tomoyo_audit_net_log - Audit network log.
353  *
354  * @r:         Pointer to "struct tomoyo_request_info".
355  * @family:    Name of socket family ("inet" or "unix").
356  * @protocol:  Name of protocol in @family.
357  * @operation: Name of socket operation.
358  * @address:   Name of address.
359  *
360  * Returns 0 on success, negative value otherwise.
361  */
362 static int tomoyo_audit_net_log(struct tomoyo_request_info *r,
363 				const char *family, const u8 protocol,
364 				const u8 operation, const char *address)
365 {
366 	return tomoyo_supervisor(r, "network %s %s %s %s\n", family,
367 				 tomoyo_proto_keyword[protocol],
368 				 tomoyo_socket_keyword[operation], address);
369 }
370 
371 /**
372  * tomoyo_audit_inet_log - Audit INET network log.
373  *
374  * @r: Pointer to "struct tomoyo_request_info".
375  *
376  * Returns 0 on success, negative value otherwise.
377  */
378 static int tomoyo_audit_inet_log(struct tomoyo_request_info *r)
379 {
380 	char buf[128];
381 	int len;
382 	const __be32 *address = r->param.inet_network.address;
383 
384 	if (r->param.inet_network.is_ipv6)
385 		tomoyo_print_ipv6(buf, sizeof(buf), (const struct in6_addr *)
386 				  address, (const struct in6_addr *) address);
387 	else
388 		tomoyo_print_ipv4(buf, sizeof(buf), address, address);
389 	len = strlen(buf);
390 	snprintf(buf + len, sizeof(buf) - len, " %u",
391 		 r->param.inet_network.port);
392 	return tomoyo_audit_net_log(r, "inet", r->param.inet_network.protocol,
393 				    r->param.inet_network.operation, buf);
394 }
395 
396 /**
397  * tomoyo_audit_unix_log - Audit UNIX network log.
398  *
399  * @r: Pointer to "struct tomoyo_request_info".
400  *
401  * Returns 0 on success, negative value otherwise.
402  */
403 static int tomoyo_audit_unix_log(struct tomoyo_request_info *r)
404 {
405 	return tomoyo_audit_net_log(r, "unix", r->param.unix_network.protocol,
406 				    r->param.unix_network.operation,
407 				    r->param.unix_network.address->name);
408 }
409 
410 /**
411  * tomoyo_check_inet_acl - Check permission for inet domain socket operation.
412  *
413  * @r:   Pointer to "struct tomoyo_request_info".
414  * @ptr: Pointer to "struct tomoyo_acl_info".
415  *
416  * Returns true if granted, false otherwise.
417  */
418 static bool tomoyo_check_inet_acl(struct tomoyo_request_info *r,
419 				  const struct tomoyo_acl_info *ptr)
420 {
421 	const struct tomoyo_inet_acl *acl =
422 		container_of(ptr, typeof(*acl), head);
423 	const u8 size = r->param.inet_network.is_ipv6 ? 16 : 4;
424 
425 	if (!(acl->perm & (1 << r->param.inet_network.operation)) ||
426 	    !tomoyo_compare_number_union(r->param.inet_network.port,
427 					 &acl->port))
428 		return false;
429 	if (acl->address.group)
430 		return tomoyo_address_matches_group
431 			(r->param.inet_network.is_ipv6,
432 			 r->param.inet_network.address, acl->address.group);
433 	return acl->address.is_ipv6 == r->param.inet_network.is_ipv6 &&
434 		memcmp(&acl->address.ip[0],
435 		       r->param.inet_network.address, size) <= 0 &&
436 		memcmp(r->param.inet_network.address,
437 		       &acl->address.ip[1], size) <= 0;
438 }
439 
440 /**
441  * tomoyo_check_unix_acl - Check permission for unix domain socket operation.
442  *
443  * @r:   Pointer to "struct tomoyo_request_info".
444  * @ptr: Pointer to "struct tomoyo_acl_info".
445  *
446  * Returns true if granted, false otherwise.
447  */
448 static bool tomoyo_check_unix_acl(struct tomoyo_request_info *r,
449 				  const struct tomoyo_acl_info *ptr)
450 {
451 	const struct tomoyo_unix_acl *acl =
452 		container_of(ptr, typeof(*acl), head);
453 
454 	return (acl->perm & (1 << r->param.unix_network.operation)) &&
455 		tomoyo_compare_name_union(r->param.unix_network.address,
456 					  &acl->name);
457 }
458 
459 /**
460  * tomoyo_inet_entry - Check permission for INET network operation.
461  *
462  * @address: Pointer to "struct tomoyo_addr_info".
463  *
464  * Returns 0 on success, negative value otherwise.
465  */
466 static int tomoyo_inet_entry(const struct tomoyo_addr_info *address)
467 {
468 	const int idx = tomoyo_read_lock();
469 	struct tomoyo_request_info r;
470 	int error = 0;
471 	const u8 type = tomoyo_inet2mac[address->protocol][address->operation];
472 
473 	if (type && tomoyo_init_request_info(&r, NULL, type)
474 	    != TOMOYO_CONFIG_DISABLED) {
475 		r.param_type = TOMOYO_TYPE_INET_ACL;
476 		r.param.inet_network.protocol = address->protocol;
477 		r.param.inet_network.operation = address->operation;
478 		r.param.inet_network.is_ipv6 = address->inet.is_ipv6;
479 		r.param.inet_network.address = address->inet.address;
480 		r.param.inet_network.port = ntohs(address->inet.port);
481 		do {
482 			tomoyo_check_acl(&r, tomoyo_check_inet_acl);
483 			error = tomoyo_audit_inet_log(&r);
484 		} while (error == TOMOYO_RETRY_REQUEST);
485 	}
486 	tomoyo_read_unlock(idx);
487 	return error;
488 }
489 
490 /**
491  * tomoyo_check_inet_address - Check permission for inet domain socket's operation.
492  *
493  * @addr:     Pointer to "struct sockaddr".
494  * @addr_len: Size of @addr.
495  * @port:     Port number.
496  * @address:  Pointer to "struct tomoyo_addr_info".
497  *
498  * Returns 0 on success, negative value otherwise.
499  */
500 static int tomoyo_check_inet_address(const struct sockaddr *addr,
501 				     const unsigned int addr_len,
502 				     const u16 port,
503 				     struct tomoyo_addr_info *address)
504 {
505 	struct tomoyo_inet_addr_info *i = &address->inet;
506 
507 	switch (addr->sa_family) {
508 	case AF_INET6:
509 		if (addr_len < SIN6_LEN_RFC2133)
510 			goto skip;
511 		i->is_ipv6 = true;
512 		i->address = (__be32 *)
513 			((struct sockaddr_in6 *) addr)->sin6_addr.s6_addr;
514 		i->port = ((struct sockaddr_in6 *) addr)->sin6_port;
515 		break;
516 	case AF_INET:
517 		if (addr_len < sizeof(struct sockaddr_in))
518 			goto skip;
519 		i->is_ipv6 = false;
520 		i->address = (__be32 *)
521 			&((struct sockaddr_in *) addr)->sin_addr;
522 		i->port = ((struct sockaddr_in *) addr)->sin_port;
523 		break;
524 	default:
525 		goto skip;
526 	}
527 	if (address->protocol == SOCK_RAW)
528 		i->port = htons(port);
529 	return tomoyo_inet_entry(address);
530 skip:
531 	return 0;
532 }
533 
534 /**
535  * tomoyo_unix_entry - Check permission for UNIX network operation.
536  *
537  * @address: Pointer to "struct tomoyo_addr_info".
538  *
539  * Returns 0 on success, negative value otherwise.
540  */
541 static int tomoyo_unix_entry(const struct tomoyo_addr_info *address)
542 {
543 	const int idx = tomoyo_read_lock();
544 	struct tomoyo_request_info r;
545 	int error = 0;
546 	const u8 type = tomoyo_unix2mac[address->protocol][address->operation];
547 
548 	if (type && tomoyo_init_request_info(&r, NULL, type)
549 	    != TOMOYO_CONFIG_DISABLED) {
550 		char *buf = address->unix0.addr;
551 		int len = address->unix0.addr_len - sizeof(sa_family_t);
552 
553 		if (len <= 0) {
554 			buf = "anonymous";
555 			len = 9;
556 		} else if (buf[0]) {
557 			len = strnlen(buf, len);
558 		}
559 		buf = tomoyo_encode2(buf, len);
560 		if (buf) {
561 			struct tomoyo_path_info addr;
562 
563 			addr.name = buf;
564 			tomoyo_fill_path_info(&addr);
565 			r.param_type = TOMOYO_TYPE_UNIX_ACL;
566 			r.param.unix_network.protocol = address->protocol;
567 			r.param.unix_network.operation = address->operation;
568 			r.param.unix_network.address = &addr;
569 			do {
570 				tomoyo_check_acl(&r, tomoyo_check_unix_acl);
571 				error = tomoyo_audit_unix_log(&r);
572 			} while (error == TOMOYO_RETRY_REQUEST);
573 			kfree(buf);
574 		} else
575 			error = -ENOMEM;
576 	}
577 	tomoyo_read_unlock(idx);
578 	return error;
579 }
580 
581 /**
582  * tomoyo_check_unix_address - Check permission for unix domain socket's operation.
583  *
584  * @addr:     Pointer to "struct sockaddr".
585  * @addr_len: Size of @addr.
586  * @address:  Pointer to "struct tomoyo_addr_info".
587  *
588  * Returns 0 on success, negative value otherwise.
589  */
590 static int tomoyo_check_unix_address(struct sockaddr *addr,
591 				     const unsigned int addr_len,
592 				     struct tomoyo_addr_info *address)
593 {
594 	struct tomoyo_unix_addr_info *u = &address->unix0;
595 
596 	if (addr->sa_family != AF_UNIX)
597 		return 0;
598 	u->addr = ((struct sockaddr_un *) addr)->sun_path;
599 	u->addr_len = addr_len;
600 	return tomoyo_unix_entry(address);
601 }
602 
603 /**
604  * tomoyo_kernel_service - Check whether I'm kernel service or not.
605  *
606  * Returns true if I'm kernel service, false otherwise.
607  */
608 static bool tomoyo_kernel_service(void)
609 {
610 	/* Nothing to do if I am a kernel service. */
611 	return uaccess_kernel();
612 }
613 
614 /**
615  * tomoyo_sock_family - Get socket's family.
616  *
617  * @sk: Pointer to "struct sock".
618  *
619  * Returns one of PF_INET, PF_INET6, PF_UNIX or 0.
620  */
621 static u8 tomoyo_sock_family(struct sock *sk)
622 {
623 	u8 family;
624 
625 	if (tomoyo_kernel_service())
626 		return 0;
627 	family = sk->sk_family;
628 	switch (family) {
629 	case PF_INET:
630 	case PF_INET6:
631 	case PF_UNIX:
632 		return family;
633 	default:
634 		return 0;
635 	}
636 }
637 
638 /**
639  * tomoyo_socket_listen_permission - Check permission for listening a socket.
640  *
641  * @sock: Pointer to "struct socket".
642  *
643  * Returns 0 on success, negative value otherwise.
644  */
645 int tomoyo_socket_listen_permission(struct socket *sock)
646 {
647 	struct tomoyo_addr_info address;
648 	const u8 family = tomoyo_sock_family(sock->sk);
649 	const unsigned int type = sock->type;
650 	struct sockaddr_storage addr;
651 	int addr_len;
652 
653 	if (!family || (type != SOCK_STREAM && type != SOCK_SEQPACKET))
654 		return 0;
655 	{
656 		const int error = sock->ops->getname(sock, (struct sockaddr *)
657 						     &addr, &addr_len, 0);
658 
659 		if (error)
660 			return error;
661 	}
662 	address.protocol = type;
663 	address.operation = TOMOYO_NETWORK_LISTEN;
664 	if (family == PF_UNIX)
665 		return tomoyo_check_unix_address((struct sockaddr *) &addr,
666 						 addr_len, &address);
667 	return tomoyo_check_inet_address((struct sockaddr *) &addr, addr_len,
668 					 0, &address);
669 }
670 
671 /**
672  * tomoyo_socket_connect_permission - Check permission for setting the remote address of a socket.
673  *
674  * @sock:     Pointer to "struct socket".
675  * @addr:     Pointer to "struct sockaddr".
676  * @addr_len: Size of @addr.
677  *
678  * Returns 0 on success, negative value otherwise.
679  */
680 int tomoyo_socket_connect_permission(struct socket *sock,
681 				     struct sockaddr *addr, int addr_len)
682 {
683 	struct tomoyo_addr_info address;
684 	const u8 family = tomoyo_sock_family(sock->sk);
685 	const unsigned int type = sock->type;
686 
687 	if (!family)
688 		return 0;
689 	address.protocol = type;
690 	switch (type) {
691 	case SOCK_DGRAM:
692 	case SOCK_RAW:
693 		address.operation = TOMOYO_NETWORK_SEND;
694 		break;
695 	case SOCK_STREAM:
696 	case SOCK_SEQPACKET:
697 		address.operation = TOMOYO_NETWORK_CONNECT;
698 		break;
699 	default:
700 		return 0;
701 	}
702 	if (family == PF_UNIX)
703 		return tomoyo_check_unix_address(addr, addr_len, &address);
704 	return tomoyo_check_inet_address(addr, addr_len, sock->sk->sk_protocol,
705 					 &address);
706 }
707 
708 /**
709  * tomoyo_socket_bind_permission - Check permission for setting the local address of a socket.
710  *
711  * @sock:     Pointer to "struct socket".
712  * @addr:     Pointer to "struct sockaddr".
713  * @addr_len: Size of @addr.
714  *
715  * Returns 0 on success, negative value otherwise.
716  */
717 int tomoyo_socket_bind_permission(struct socket *sock, struct sockaddr *addr,
718 				  int addr_len)
719 {
720 	struct tomoyo_addr_info address;
721 	const u8 family = tomoyo_sock_family(sock->sk);
722 	const unsigned int type = sock->type;
723 
724 	if (!family)
725 		return 0;
726 	switch (type) {
727 	case SOCK_STREAM:
728 	case SOCK_DGRAM:
729 	case SOCK_RAW:
730 	case SOCK_SEQPACKET:
731 		address.protocol = type;
732 		address.operation = TOMOYO_NETWORK_BIND;
733 		break;
734 	default:
735 		return 0;
736 	}
737 	if (family == PF_UNIX)
738 		return tomoyo_check_unix_address(addr, addr_len, &address);
739 	return tomoyo_check_inet_address(addr, addr_len, sock->sk->sk_protocol,
740 					 &address);
741 }
742 
743 /**
744  * tomoyo_socket_sendmsg_permission - Check permission for sending a datagram.
745  *
746  * @sock: Pointer to "struct socket".
747  * @msg:  Pointer to "struct msghdr".
748  * @size: Unused.
749  *
750  * Returns 0 on success, negative value otherwise.
751  */
752 int tomoyo_socket_sendmsg_permission(struct socket *sock, struct msghdr *msg,
753 				     int size)
754 {
755 	struct tomoyo_addr_info address;
756 	const u8 family = tomoyo_sock_family(sock->sk);
757 	const unsigned int type = sock->type;
758 
759 	if (!msg->msg_name || !family ||
760 	    (type != SOCK_DGRAM && type != SOCK_RAW))
761 		return 0;
762 	address.protocol = type;
763 	address.operation = TOMOYO_NETWORK_SEND;
764 	if (family == PF_UNIX)
765 		return tomoyo_check_unix_address((struct sockaddr *)
766 						 msg->msg_name,
767 						 msg->msg_namelen, &address);
768 	return tomoyo_check_inet_address((struct sockaddr *) msg->msg_name,
769 					 msg->msg_namelen,
770 					 sock->sk->sk_protocol, &address);
771 }
772