1 /* $NetBSD: scope6.c,v 1.23 2020/06/16 17:12:18 maxv Exp $ */
2 /* $KAME$ */
3
4 /*
5 * Copyright (C) 2000 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: scope6.c,v 1.23 2020/06/16 17:12:18 maxv Exp $");
35
36 #include <sys/param.h>
37 #include <sys/malloc.h>
38 #include <sys/mbuf.h>
39 #include <sys/socket.h>
40 #include <sys/systm.h>
41 #include <sys/queue.h>
42 #include <sys/syslog.h>
43
44 #include <net/if.h>
45
46 #include <netinet/in.h>
47
48 #include <netinet6/in6_var.h>
49 #include <netinet6/scope6_var.h>
50
51 #ifdef ENABLE_DEFAULT_SCOPE
52 int ip6_use_defzone = 1;
53 #else
54 int ip6_use_defzone = 0;
55 #endif
56
57 static struct scope6_id sid_default;
58 #define SID(ifp) \
59 ((ifp)->if_afdata[AF_INET6] == NULL ? NULL : \
60 ((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
61
62 void
scope6_init(void)63 scope6_init(void)
64 {
65
66 memset(&sid_default, 0, sizeof(sid_default));
67 }
68
69 struct scope6_id *
scope6_ifattach(struct ifnet * ifp)70 scope6_ifattach(struct ifnet *ifp)
71 {
72 struct scope6_id *sid;
73
74 sid = malloc(sizeof(*sid), M_IFADDR, M_WAITOK | M_ZERO);
75
76 /*
77 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
78 * Should we rather hardcode here?
79 */
80 sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
81 sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
82 #ifdef MULTI_SCOPE
83 /* by default, we don't care about scope boundary for these scopes. */
84 sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
85 sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
86 #endif
87
88 return sid;
89 }
90
91 void
scope6_ifdetach(struct scope6_id * sid)92 scope6_ifdetach(struct scope6_id *sid)
93 {
94
95 free(sid, M_IFADDR);
96 }
97
98 /*
99 * Get a scope of the address. Interface-local, link-local, site-local
100 * or global.
101 */
102 int
in6_addrscope(const struct in6_addr * addr)103 in6_addrscope(const struct in6_addr *addr)
104 {
105 int scope;
106
107 if (addr->s6_addr[0] == 0xfe) {
108 scope = addr->s6_addr[1] & 0xc0;
109
110 switch (scope) {
111 case 0x80:
112 return IPV6_ADDR_SCOPE_LINKLOCAL;
113 case 0xc0:
114 return IPV6_ADDR_SCOPE_SITELOCAL;
115 default:
116 return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
117 }
118 }
119
120 if (addr->s6_addr[0] == 0xff) {
121 scope = addr->s6_addr[1] & 0x0f;
122
123 /*
124 * due to other scope such as reserved,
125 * return scope doesn't work.
126 */
127 switch (scope) {
128 case IPV6_ADDR_SCOPE_INTFACELOCAL:
129 return IPV6_ADDR_SCOPE_INTFACELOCAL;
130 case IPV6_ADDR_SCOPE_LINKLOCAL:
131 return IPV6_ADDR_SCOPE_LINKLOCAL;
132 case IPV6_ADDR_SCOPE_SITELOCAL:
133 return IPV6_ADDR_SCOPE_SITELOCAL;
134 default:
135 return IPV6_ADDR_SCOPE_GLOBAL;
136 }
137 }
138
139 if (memcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
140 if (addr->s6_addr[15] == 1) /* loopback */
141 return IPV6_ADDR_SCOPE_LINKLOCAL;
142 if (addr->s6_addr[15] == 0) {
143 /*
144 * Regard the unspecified addresses as global,
145 * since it has no ambiguity.
146 * XXX: not sure if it's correct...
147 */
148 return IPV6_ADDR_SCOPE_GLOBAL;
149 }
150 }
151
152 return IPV6_ADDR_SCOPE_GLOBAL;
153 }
154
155 uint32_t
scope6_addr2default(const struct in6_addr * addr)156 scope6_addr2default(const struct in6_addr *addr)
157 {
158 uint32_t id;
159
160 /*
161 * special case: The loopback address should be considered as
162 * link-local, but there's no ambiguity in the syntax.
163 */
164 if (IN6_IS_ADDR_LOOPBACK(addr))
165 return 0;
166
167 /*
168 * XXX: 32-bit read is atomic on all our platforms, is it OK
169 * not to lock here?
170 */
171 id = sid_default.s6id_list[in6_addrscope(addr)];
172
173 return id;
174 }
175
176 /*
177 * Validate the specified scope zone ID in the sin6_scope_id field. If the ID
178 * is unspecified (=0), needs to be specified, and the default zone ID can be
179 * used, the default value will be used.
180 * This routine then generates the kernel-internal form: if the address scope
181 * of is interface-local or link-local, embed the interface index in the
182 * address.
183 */
184 int
sa6_embedscope(struct sockaddr_in6 * sin6,int defaultok)185 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
186 {
187 struct ifnet *ifp;
188 uint32_t zoneid;
189
190 if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
191 zoneid = scope6_addr2default(&sin6->sin6_addr);
192
193 if (zoneid != 0 &&
194 (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
195 IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
196 int s;
197 /*
198 * At this moment, we only check interface-local and
199 * link-local scope IDs, and use interface indices as the
200 * zone IDs assuming a one-to-one mapping between interfaces
201 * and links.
202 */
203 s = pserialize_read_enter();
204 ifp = if_byindex(zoneid);
205 if (ifp == NULL) {
206 pserialize_read_exit(s);
207 return ENXIO;
208 }
209 pserialize_read_exit(s);
210
211 /* XXX assignment to 16bit from 32bit variable */
212 sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
213
214 sin6->sin6_scope_id = 0;
215 }
216
217 return 0;
218 }
219
220 struct sockaddr *
sockaddr_in6_externalize(struct sockaddr * dst,socklen_t socklen,const struct sockaddr * src)221 sockaddr_in6_externalize(struct sockaddr *dst, socklen_t socklen,
222 const struct sockaddr *src)
223 {
224 struct sockaddr_in6 *sin6;
225
226 sin6 = satosin6(sockaddr_copy(dst, socklen, src));
227
228 if (sin6 == NULL || sa6_recoverscope(sin6) != 0)
229 return NULL;
230
231 return dst;
232 }
233
234 /*
235 * generate standard sockaddr_in6 from embedded form.
236 */
237 int
sa6_recoverscope(struct sockaddr_in6 * sin6)238 sa6_recoverscope(struct sockaddr_in6 *sin6)
239 {
240 uint32_t zoneid;
241 char ip6buf[INET6_ADDRSTRLEN];
242
243 if (sin6->sin6_scope_id != 0) {
244 log(LOG_NOTICE,
245 "%s: assumption failure (non 0 ID): %s%%%d\n", __func__,
246 IN6_PRINT(ip6buf, &sin6->sin6_addr), sin6->sin6_scope_id);
247 /* XXX: proceed anyway... */
248 }
249 if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
250 IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
251 /*
252 * KAME assumption: link id == interface id
253 */
254 zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
255 if (zoneid) {
256 int s = pserialize_read_enter();
257 if (!if_byindex(zoneid)) {
258 pserialize_read_exit(s);
259 return ENXIO;
260 }
261 pserialize_read_exit(s);
262 sin6->sin6_addr.s6_addr16[1] = 0;
263 sin6->sin6_scope_id = zoneid;
264 }
265 }
266
267 return 0;
268 }
269
270 int
in6_setzoneid(struct in6_addr * in6,uint32_t zoneid)271 in6_setzoneid(struct in6_addr *in6, uint32_t zoneid)
272 {
273 if (IN6_IS_SCOPE_EMBEDDABLE(in6))
274 in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
275
276 return 0;
277 }
278
279 /*
280 * Determine the appropriate scope zone ID for in6 and ifp. If ret_id is
281 * non NULL, it is set to the zone ID. If the zone ID needs to be embedded
282 * in the in6_addr structure, in6 will be modified.
283 */
284 int
in6_setscope(struct in6_addr * in6,const struct ifnet * ifp,uint32_t * ret_id)285 in6_setscope(struct in6_addr *in6, const struct ifnet *ifp, uint32_t *ret_id)
286 {
287 int scope;
288 uint32_t zoneid = 0;
289 const struct scope6_id *sid = SID(ifp);
290
291 if (sid == NULL) {
292 log(LOG_NOTICE, "%s: no scope id for %s\n", __func__,
293 if_name(ifp));
294 return EINVAL;
295 }
296
297 /*
298 * special case: the loopback address can only belong to a loopback
299 * interface.
300 */
301 if (IN6_IS_ADDR_LOOPBACK(in6)) {
302 if (!(ifp->if_flags & IFF_LOOPBACK)) {
303 char ip6buf[INET6_ADDRSTRLEN];
304 log(LOG_NOTICE, "%s: can't set scope for not loopback "
305 "interface %s and loopback address %s\n",
306 __func__, if_name(ifp), IN6_PRINT(ip6buf, in6));
307 return EINVAL;
308 } else {
309 if (ret_id != NULL)
310 *ret_id = 0; /* there's no ambiguity */
311 return 0;
312 }
313 }
314
315 scope = in6_addrscope(in6);
316
317 switch (scope) {
318 case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
319 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
320 break;
321
322 case IPV6_ADDR_SCOPE_LINKLOCAL:
323 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
324 break;
325
326 case IPV6_ADDR_SCOPE_SITELOCAL:
327 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
328 break;
329
330 case IPV6_ADDR_SCOPE_ORGLOCAL:
331 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
332 break;
333
334 default:
335 zoneid = 0; /* XXX: treat as global. */
336 break;
337 }
338
339 if (ret_id != NULL)
340 *ret_id = zoneid;
341
342 return in6_setzoneid(in6, zoneid);
343 }
344
345 const char *
in6_getscopename(const struct in6_addr * addr)346 in6_getscopename(const struct in6_addr *addr)
347 {
348 switch (in6_addrscope(addr)) {
349 case IPV6_ADDR_SCOPE_INTFACELOCAL:
350 return "interface";
351 #if IPV6_ADDR_SCOPE_INTFACELOCAL != IPV6_ADDR_SCOPE_NODELOCAL
352 case IPV6_ADDR_SCOPE_NODELOCAL:
353 return "node";
354 #endif
355 case IPV6_ADDR_SCOPE_LINKLOCAL:
356 return "link";
357 case IPV6_ADDR_SCOPE_SITELOCAL:
358 return "site";
359 case IPV6_ADDR_SCOPE_ORGLOCAL:
360 return "organization";
361 case IPV6_ADDR_SCOPE_GLOBAL:
362 return "global";
363 default:
364 return "unknown";
365 }
366 }
367
368 /*
369 * Just clear the embedded scope identifier. Return 0 if the original address
370 * is intact; return non 0 if the address is modified.
371 */
372 int
in6_clearscope(struct in6_addr * in6)373 in6_clearscope(struct in6_addr *in6)
374 {
375 int modified = 0;
376
377 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
378 if (in6->s6_addr16[1] != 0)
379 modified = 1;
380 in6->s6_addr16[1] = 0;
381 }
382
383 return modified;
384 }
385