Merge branch 'spectre' of git://git.armlinux.org.uk/~rmk/linux-arm
[sfrench/cifs-2.6.git] / security / tomoyo / network.c
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         switch (addr->sa_family) {
509         case AF_INET6:
510                 if (addr_len < SIN6_LEN_RFC2133)
511                         goto skip;
512                 i->is_ipv6 = true;
513                 i->address = (__be32 *)
514                         ((struct sockaddr_in6 *) addr)->sin6_addr.s6_addr;
515                 i->port = ((struct sockaddr_in6 *) addr)->sin6_port;
516                 break;
517         case AF_INET:
518                 if (addr_len < sizeof(struct sockaddr_in))
519                         goto skip;
520                 i->is_ipv6 = false;
521                 i->address = (__be32 *)
522                         &((struct sockaddr_in *) addr)->sin_addr;
523                 i->port = ((struct sockaddr_in *) addr)->sin_port;
524                 break;
525         default:
526                 goto skip;
527         }
528         if (address->protocol == SOCK_RAW)
529                 i->port = htons(port);
530         return tomoyo_inet_entry(address);
531 skip:
532         return 0;
533 }
534
535 /**
536  * tomoyo_unix_entry - Check permission for UNIX network operation.
537  *
538  * @address: Pointer to "struct tomoyo_addr_info".
539  *
540  * Returns 0 on success, negative value otherwise.
541  */
542 static int tomoyo_unix_entry(const struct tomoyo_addr_info *address)
543 {
544         const int idx = tomoyo_read_lock();
545         struct tomoyo_request_info r;
546         int error = 0;
547         const u8 type = tomoyo_unix2mac[address->protocol][address->operation];
548
549         if (type && tomoyo_init_request_info(&r, NULL, type)
550             != TOMOYO_CONFIG_DISABLED) {
551                 char *buf = address->unix0.addr;
552                 int len = address->unix0.addr_len - sizeof(sa_family_t);
553
554                 if (len <= 0) {
555                         buf = "anonymous";
556                         len = 9;
557                 } else if (buf[0]) {
558                         len = strnlen(buf, len);
559                 }
560                 buf = tomoyo_encode2(buf, len);
561                 if (buf) {
562                         struct tomoyo_path_info addr;
563
564                         addr.name = buf;
565                         tomoyo_fill_path_info(&addr);
566                         r.param_type = TOMOYO_TYPE_UNIX_ACL;
567                         r.param.unix_network.protocol = address->protocol;
568                         r.param.unix_network.operation = address->operation;
569                         r.param.unix_network.address = &addr;
570                         do {
571                                 tomoyo_check_acl(&r, tomoyo_check_unix_acl);
572                                 error = tomoyo_audit_unix_log(&r);
573                         } while (error == TOMOYO_RETRY_REQUEST);
574                         kfree(buf);
575                 } else
576                         error = -ENOMEM;
577         }
578         tomoyo_read_unlock(idx);
579         return error;
580 }
581
582 /**
583  * tomoyo_check_unix_address - Check permission for unix domain socket's operation.
584  *
585  * @addr:     Pointer to "struct sockaddr".
586  * @addr_len: Size of @addr.
587  * @address:  Pointer to "struct tomoyo_addr_info".
588  *
589  * Returns 0 on success, negative value otherwise.
590  */
591 static int tomoyo_check_unix_address(struct sockaddr *addr,
592                                      const unsigned int addr_len,
593                                      struct tomoyo_addr_info *address)
594 {
595         struct tomoyo_unix_addr_info *u = &address->unix0;
596
597         if (addr->sa_family != AF_UNIX)
598                 return 0;
599         u->addr = ((struct sockaddr_un *) addr)->sun_path;
600         u->addr_len = addr_len;
601         return tomoyo_unix_entry(address);
602 }
603
604 /**
605  * tomoyo_kernel_service - Check whether I'm kernel service or not.
606  *
607  * Returns true if I'm kernel service, false otherwise.
608  */
609 static bool tomoyo_kernel_service(void)
610 {
611         /* Nothing to do if I am a kernel service. */
612         return uaccess_kernel();
613 }
614
615 /**
616  * tomoyo_sock_family - Get socket's family.
617  *
618  * @sk: Pointer to "struct sock".
619  *
620  * Returns one of PF_INET, PF_INET6, PF_UNIX or 0.
621  */
622 static u8 tomoyo_sock_family(struct sock *sk)
623 {
624         u8 family;
625
626         if (tomoyo_kernel_service())
627                 return 0;
628         family = sk->sk_family;
629         switch (family) {
630         case PF_INET:
631         case PF_INET6:
632         case PF_UNIX:
633                 return family;
634         default:
635                 return 0;
636         }
637 }
638
639 /**
640  * tomoyo_socket_listen_permission - Check permission for listening a socket.
641  *
642  * @sock: Pointer to "struct socket".
643  *
644  * Returns 0 on success, negative value otherwise.
645  */
646 int tomoyo_socket_listen_permission(struct socket *sock)
647 {
648         struct tomoyo_addr_info address;
649         const u8 family = tomoyo_sock_family(sock->sk);
650         const unsigned int type = sock->type;
651         struct sockaddr_storage addr;
652         int addr_len;
653
654         if (!family || (type != SOCK_STREAM && type != SOCK_SEQPACKET))
655                 return 0;
656         {
657                 const int error = sock->ops->getname(sock, (struct sockaddr *)
658                                                      &addr, 0);
659
660                 if (error < 0)
661                         return error;
662                 addr_len = error;
663         }
664         address.protocol = type;
665         address.operation = TOMOYO_NETWORK_LISTEN;
666         if (family == PF_UNIX)
667                 return tomoyo_check_unix_address((struct sockaddr *) &addr,
668                                                  addr_len, &address);
669         return tomoyo_check_inet_address((struct sockaddr *) &addr, addr_len,
670                                          0, &address);
671 }
672
673 /**
674  * tomoyo_socket_connect_permission - Check permission for setting the remote address of a socket.
675  *
676  * @sock:     Pointer to "struct socket".
677  * @addr:     Pointer to "struct sockaddr".
678  * @addr_len: Size of @addr.
679  *
680  * Returns 0 on success, negative value otherwise.
681  */
682 int tomoyo_socket_connect_permission(struct socket *sock,
683                                      struct sockaddr *addr, int addr_len)
684 {
685         struct tomoyo_addr_info address;
686         const u8 family = tomoyo_sock_family(sock->sk);
687         const unsigned int type = sock->type;
688
689         if (!family)
690                 return 0;
691         address.protocol = type;
692         switch (type) {
693         case SOCK_DGRAM:
694         case SOCK_RAW:
695                 address.operation = TOMOYO_NETWORK_SEND;
696                 break;
697         case SOCK_STREAM:
698         case SOCK_SEQPACKET:
699                 address.operation = TOMOYO_NETWORK_CONNECT;
700                 break;
701         default:
702                 return 0;
703         }
704         if (family == PF_UNIX)
705                 return tomoyo_check_unix_address(addr, addr_len, &address);
706         return tomoyo_check_inet_address(addr, addr_len, sock->sk->sk_protocol,
707                                          &address);
708 }
709
710 /**
711  * tomoyo_socket_bind_permission - Check permission for setting the local address of a socket.
712  *
713  * @sock:     Pointer to "struct socket".
714  * @addr:     Pointer to "struct sockaddr".
715  * @addr_len: Size of @addr.
716  *
717  * Returns 0 on success, negative value otherwise.
718  */
719 int tomoyo_socket_bind_permission(struct socket *sock, struct sockaddr *addr,
720                                   int addr_len)
721 {
722         struct tomoyo_addr_info address;
723         const u8 family = tomoyo_sock_family(sock->sk);
724         const unsigned int type = sock->type;
725
726         if (!family)
727                 return 0;
728         switch (type) {
729         case SOCK_STREAM:
730         case SOCK_DGRAM:
731         case SOCK_RAW:
732         case SOCK_SEQPACKET:
733                 address.protocol = type;
734                 address.operation = TOMOYO_NETWORK_BIND;
735                 break;
736         default:
737                 return 0;
738         }
739         if (family == PF_UNIX)
740                 return tomoyo_check_unix_address(addr, addr_len, &address);
741         return tomoyo_check_inet_address(addr, addr_len, sock->sk->sk_protocol,
742                                          &address);
743 }
744
745 /**
746  * tomoyo_socket_sendmsg_permission - Check permission for sending a datagram.
747  *
748  * @sock: Pointer to "struct socket".
749  * @msg:  Pointer to "struct msghdr".
750  * @size: Unused.
751  *
752  * Returns 0 on success, negative value otherwise.
753  */
754 int tomoyo_socket_sendmsg_permission(struct socket *sock, struct msghdr *msg,
755                                      int size)
756 {
757         struct tomoyo_addr_info address;
758         const u8 family = tomoyo_sock_family(sock->sk);
759         const unsigned int type = sock->type;
760
761         if (!msg->msg_name || !family ||
762             (type != SOCK_DGRAM && type != SOCK_RAW))
763                 return 0;
764         address.protocol = type;
765         address.operation = TOMOYO_NETWORK_SEND;
766         if (family == PF_UNIX)
767                 return tomoyo_check_unix_address((struct sockaddr *)
768                                                  msg->msg_name,
769                                                  msg->msg_namelen, &address);
770         return tomoyo_check_inet_address((struct sockaddr *) msg->msg_name,
771                                          msg->msg_namelen,
772                                          sock->sk->sk_protocol, &address);
773 }