1 | /* $NetBSD: in6_src.c,v 1.74 2016/11/10 04:13:53 ozaki-r Exp $ */ |
2 | /* $KAME: in6_src.c,v 1.159 2005/10/19 01:40:32 t-momose Exp $ */ |
3 | |
4 | /* |
5 | * Copyright (C) 1995, 1996, 1997, and 1998 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 | /* |
34 | * Copyright (c) 1982, 1986, 1991, 1993 |
35 | * The Regents of the University of California. All rights reserved. |
36 | * |
37 | * Redistribution and use in source and binary forms, with or without |
38 | * modification, are permitted provided that the following conditions |
39 | * are met: |
40 | * 1. Redistributions of source code must retain the above copyright |
41 | * notice, this list of conditions and the following disclaimer. |
42 | * 2. Redistributions in binary form must reproduce the above copyright |
43 | * notice, this list of conditions and the following disclaimer in the |
44 | * documentation and/or other materials provided with the distribution. |
45 | * 3. All advertising materials mentioning features or use of this software |
46 | * must display the following acknowledgement: |
47 | * This product includes software developed by the University of |
48 | * California, Berkeley and its contributors. |
49 | * 4. Neither the name of the University nor the names of its contributors |
50 | * may be used to endorse or promote products derived from this software |
51 | * without specific prior written permission. |
52 | * |
53 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
54 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
55 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
56 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
57 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
58 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
59 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
60 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
61 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
62 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
63 | * SUCH DAMAGE. |
64 | * |
65 | * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94 |
66 | */ |
67 | |
68 | #include <sys/cdefs.h> |
69 | __KERNEL_RCSID(0, "$NetBSD: in6_src.c,v 1.74 2016/11/10 04:13:53 ozaki-r Exp $" ); |
70 | |
71 | #ifdef _KERNEL_OPT |
72 | #include "opt_inet.h" |
73 | #endif |
74 | |
75 | #include <sys/param.h> |
76 | #include <sys/systm.h> |
77 | #include <sys/malloc.h> |
78 | #include <sys/mbuf.h> |
79 | #include <sys/protosw.h> |
80 | #include <sys/socket.h> |
81 | #include <sys/socketvar.h> |
82 | #include <sys/ioctl.h> |
83 | #include <sys/errno.h> |
84 | #include <sys/time.h> |
85 | #include <sys/kernel.h> |
86 | #include <sys/proc.h> |
87 | #include <sys/kauth.h> |
88 | |
89 | #include <net/if.h> |
90 | #include <net/if_types.h> |
91 | #include <net/route.h> |
92 | |
93 | #include <netinet/in.h> |
94 | #include <netinet/in_var.h> |
95 | #include <netinet/in_systm.h> |
96 | #include <netinet/ip.h> |
97 | #include <netinet/in_pcb.h> |
98 | #include <netinet/portalgo.h> |
99 | #include <netinet6/in6_var.h> |
100 | #include <netinet/ip6.h> |
101 | #include <netinet6/in6_pcb.h> |
102 | #include <netinet6/ip6_var.h> |
103 | #include <netinet6/ip6_private.h> |
104 | #include <netinet6/nd6.h> |
105 | #include <netinet6/scope6_var.h> |
106 | |
107 | #include <net/net_osdep.h> |
108 | |
109 | #ifdef MIP6 |
110 | #include <netinet6/mip6.h> |
111 | #include <netinet6/mip6_var.h> |
112 | #include "mip.h" |
113 | #if NMIP > 0 |
114 | #include <net/if_mip.h> |
115 | #endif /* NMIP > 0 */ |
116 | #endif /* MIP6 */ |
117 | |
118 | #include <netinet/tcp_vtw.h> |
119 | |
120 | #define ADDR_LABEL_NOTAPP (-1) |
121 | struct in6_addrpolicy defaultaddrpolicy; |
122 | |
123 | int ip6_prefer_tempaddr = 0; |
124 | |
125 | static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, |
126 | struct ip6_moptions *, struct route *, struct ifnet **, struct psref *); |
127 | |
128 | static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *); |
129 | |
130 | static void init_policy_queue(void); |
131 | static int add_addrsel_policyent(struct in6_addrpolicy *); |
132 | static int delete_addrsel_policyent(struct in6_addrpolicy *); |
133 | static int walk_addrsel_policy(int (*)(struct in6_addrpolicy *, void *), |
134 | void *); |
135 | static int dump_addrsel_policyent(struct in6_addrpolicy *, void *); |
136 | static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *); |
137 | |
138 | /* |
139 | * Return an IPv6 address, which is the most appropriate for a given |
140 | * destination and user specified options. |
141 | * If necessary, this function lookups the routing table and returns |
142 | * an entry to the caller for later use. |
143 | */ |
144 | #if 0 /* diabled ad-hoc */ |
145 | #define REPLACE(r) do {\ |
146 | if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ |
147 | sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ |
148 | ip6stat.ip6s_sources_rule[(r)]++; \ |
149 | /* printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \ |
150 | goto replace; \ |
151 | } while(0) |
152 | #define NEXT(r) do {\ |
153 | if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ |
154 | sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ |
155 | ip6stat.ip6s_sources_rule[(r)]++; \ |
156 | /* printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \ |
157 | goto next; /* XXX: we can't use 'continue' here */ \ |
158 | } while(0) |
159 | #define BREAK(r) do { \ |
160 | if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ |
161 | sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ |
162 | ip6stat.ip6s_sources_rule[(r)]++; \ |
163 | goto out; /* XXX: we can't use 'break' here */ \ |
164 | } while(0) |
165 | #else |
166 | #define REPLACE(r) goto replace |
167 | #define NEXT(r) goto next |
168 | #define BREAK(r) goto out |
169 | #endif |
170 | |
171 | /* |
172 | * Called inside pserialize critical section. Don't sleep/block. |
173 | */ |
174 | static struct in6_ifaddr * |
175 | in6_select_best_ia(struct sockaddr_in6 *dstsock, struct in6_addr *dst, |
176 | const struct ifnet *ifp, const struct ip6_pktopts *opts, |
177 | const u_int32_t odstzone) |
178 | { |
179 | struct in6_ifaddr *ia, *ia_best = NULL; |
180 | int dst_scope = -1, best_scope = -1, best_matchlen = -1; |
181 | struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL; |
182 | |
183 | IN6_ADDRLIST_READER_FOREACH(ia) { |
184 | int new_scope = -1, new_matchlen = -1; |
185 | struct in6_addrpolicy *new_policy = NULL; |
186 | u_int32_t srczone, osrczone, dstzone; |
187 | struct in6_addr src; |
188 | struct ifnet *ifp1 = ia->ia_ifp; |
189 | int prefer_tempaddr; |
190 | |
191 | /* |
192 | * We'll never take an address that breaks the scope zone |
193 | * of the destination. We also skip an address if its zone |
194 | * does not contain the outgoing interface. |
195 | * XXX: we should probably use sin6_scope_id here. |
196 | */ |
197 | if (in6_setscope(dst, ifp1, &dstzone) || |
198 | odstzone != dstzone) { |
199 | continue; |
200 | } |
201 | src = ia->ia_addr.sin6_addr; |
202 | if (in6_setscope(&src, ifp, &osrczone) || |
203 | in6_setscope(&src, ifp1, &srczone) || |
204 | osrczone != srczone) { |
205 | continue; |
206 | } |
207 | |
208 | /* avoid unusable addresses */ |
209 | if ((ia->ia6_flags & |
210 | (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) { |
211 | continue; |
212 | } |
213 | if (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia)) |
214 | continue; |
215 | |
216 | #if defined(MIP6) && NMIP > 0 |
217 | /* avoid unusable home addresses. */ |
218 | if ((ia->ia6_flags & IN6_IFF_HOME) && |
219 | !mip6_ifa6_is_addr_valid_hoa(ia)) |
220 | continue; |
221 | #endif /* MIP6 && NMIP > 0 */ |
222 | |
223 | /* Rule 1: Prefer same address */ |
224 | if (IN6_ARE_ADDR_EQUAL(dst, &ia->ia_addr.sin6_addr)) { |
225 | ia_best = ia; |
226 | BREAK(1); /* there should be no better candidate */ |
227 | } |
228 | |
229 | if (ia_best == NULL) |
230 | REPLACE(0); |
231 | |
232 | /* Rule 2: Prefer appropriate scope */ |
233 | if (dst_scope < 0) |
234 | dst_scope = in6_addrscope(dst); |
235 | new_scope = in6_addrscope(&ia->ia_addr.sin6_addr); |
236 | if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) { |
237 | if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0) |
238 | REPLACE(2); |
239 | NEXT(2); |
240 | } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) { |
241 | if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) |
242 | NEXT(2); |
243 | REPLACE(2); |
244 | } |
245 | |
246 | /* |
247 | * Rule 3: Avoid deprecated addresses. Note that the case of |
248 | * !ip6_use_deprecated is already rejected above. |
249 | */ |
250 | if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia)) |
251 | NEXT(3); |
252 | if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia)) |
253 | REPLACE(3); |
254 | |
255 | /* Rule 4: Prefer home addresses */ |
256 | #if defined(MIP6) && NMIP > 0 |
257 | if (!MIP6_IS_MN) |
258 | goto skip_rule4; |
259 | |
260 | if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 && |
261 | (ia->ia6_flags & IN6_IFF_HOME) == 0) { |
262 | /* both address are not home addresses. */ |
263 | goto skip_rule4; |
264 | } |
265 | |
266 | /* |
267 | * If SA is simultaneously a home address and care-of |
268 | * address and SB is not, then prefer SA. Similarly, |
269 | * if SB is simultaneously a home address and care-of |
270 | * address and SA is not, then prefer SB. |
271 | */ |
272 | if (((ia_best->ia6_flags & IN6_IFF_HOME) != 0 && |
273 | ia_best->ia_ifp->if_type != IFT_MIP) |
274 | && |
275 | ((ia->ia6_flags & IN6_IFF_HOME) != 0 && |
276 | ia->ia_ifp->if_type == IFT_MIP)) |
277 | NEXT(4); |
278 | if (((ia_best->ia6_flags & IN6_IFF_HOME) != 0 && |
279 | ia_best->ia_ifp->if_type == IFT_MIP) |
280 | && |
281 | ((ia->ia6_flags & IN6_IFF_HOME) != 0 && |
282 | ia->ia_ifp->if_type != IFT_MIP)) |
283 | REPLACE(4); |
284 | if (ip6po_usecoa == 0) { |
285 | /* |
286 | * If SA is just a home address and SB is just |
287 | * a care-of address, then prefer |
288 | * SA. Similarly, if SB is just a home address |
289 | * and SA is just a care-of address, then |
290 | * prefer SB. |
291 | */ |
292 | if ((ia_best->ia6_flags & IN6_IFF_HOME) != 0 && |
293 | (ia->ia6_flags & IN6_IFF_HOME) == 0) { |
294 | NEXT(4); |
295 | } |
296 | if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 && |
297 | (ia->ia6_flags & IN6_IFF_HOME) != 0) { |
298 | REPLACE(4); |
299 | } |
300 | } else { |
301 | /* |
302 | * a sender don't want to use a home address |
303 | * because: |
304 | * |
305 | * 1) we cannot use. (ex. NS or NA to global |
306 | * addresses.) |
307 | * |
308 | * 2) a user specified not to use. |
309 | * (ex. mip6control -u) |
310 | */ |
311 | if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 && |
312 | (ia->ia6_flags & IN6_IFF_HOME) != 0) { |
313 | /* XXX breaks stat */ |
314 | NEXT(0); |
315 | } |
316 | if ((ia_best->ia6_flags & IN6_IFF_HOME) != 0 && |
317 | (ia->ia6_flags & IN6_IFF_HOME) == 0) { |
318 | /* XXX breaks stat */ |
319 | REPLACE(0); |
320 | } |
321 | } |
322 | skip_rule4: |
323 | #endif /* MIP6 && NMIP > 0 */ |
324 | |
325 | /* Rule 5: Prefer outgoing interface */ |
326 | if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) |
327 | NEXT(5); |
328 | if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) |
329 | REPLACE(5); |
330 | |
331 | /* |
332 | * Rule 6: Prefer matching label |
333 | * Note that best_policy should be non-NULL here. |
334 | */ |
335 | if (dst_policy == NULL) |
336 | dst_policy = lookup_addrsel_policy(dstsock); |
337 | if (dst_policy->label != ADDR_LABEL_NOTAPP) { |
338 | new_policy = lookup_addrsel_policy(&ia->ia_addr); |
339 | if (dst_policy->label == best_policy->label && |
340 | dst_policy->label != new_policy->label) |
341 | NEXT(6); |
342 | if (dst_policy->label != best_policy->label && |
343 | dst_policy->label == new_policy->label) |
344 | REPLACE(6); |
345 | } |
346 | |
347 | /* |
348 | * Rule 7: Prefer public addresses. |
349 | * We allow users to reverse the logic by configuring |
350 | * a sysctl variable, so that privacy conscious users can |
351 | * always prefer temporary addresses. |
352 | */ |
353 | if (opts == NULL || |
354 | opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) { |
355 | prefer_tempaddr = ip6_prefer_tempaddr; |
356 | } else if (opts->ip6po_prefer_tempaddr == |
357 | IP6PO_TEMPADDR_NOTPREFER) { |
358 | prefer_tempaddr = 0; |
359 | } else |
360 | prefer_tempaddr = 1; |
361 | if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) && |
362 | (ia->ia6_flags & IN6_IFF_TEMPORARY)) { |
363 | if (prefer_tempaddr) |
364 | REPLACE(7); |
365 | else |
366 | NEXT(7); |
367 | } |
368 | if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) && |
369 | !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { |
370 | if (prefer_tempaddr) |
371 | NEXT(7); |
372 | else |
373 | REPLACE(7); |
374 | } |
375 | |
376 | /* |
377 | * Rule 8: prefer addresses on alive interfaces. |
378 | * This is a KAME specific rule. |
379 | */ |
380 | if ((ia_best->ia_ifp->if_flags & IFF_UP) && |
381 | !(ia->ia_ifp->if_flags & IFF_UP)) |
382 | NEXT(8); |
383 | if (!(ia_best->ia_ifp->if_flags & IFF_UP) && |
384 | (ia->ia_ifp->if_flags & IFF_UP)) |
385 | REPLACE(8); |
386 | |
387 | /* |
388 | * Rule 9: prefer addresses on "preferred" interfaces. |
389 | * This is a KAME specific rule. |
390 | */ |
391 | #ifdef notyet /* until introducing address selection */ |
392 | #define NDI_BEST ND_IFINFO(ia_best->ia_ifp) |
393 | #define NDI_NEW ND_IFINFO(ia->ia_ifp) |
394 | if ((NDI_BEST->flags & ND6_IFF_PREFER_SOURCE) && |
395 | !(NDI_NEW->flags & ND6_IFF_PREFER_SOURCE)) |
396 | NEXT(9); |
397 | if (!(NDI_BEST->flags & ND6_IFF_PREFER_SOURCE) && |
398 | (NDI_NEW->flags & ND6_IFF_PREFER_SOURCE)) |
399 | REPLACE(9); |
400 | #undef NDI_BEST |
401 | #undef NDI_NEW |
402 | #endif |
403 | |
404 | /* |
405 | * Rule 14: Use longest matching prefix. |
406 | * Note: in the address selection draft, this rule is |
407 | * documented as "Rule 8". However, since it is also |
408 | * documented that this rule can be overridden, we assign |
409 | * a large number so that it is easy to assign smaller numbers |
410 | * to more preferred rules. |
411 | */ |
412 | new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, dst); |
413 | if (best_matchlen < new_matchlen) |
414 | REPLACE(14); |
415 | if (new_matchlen < best_matchlen) |
416 | NEXT(14); |
417 | |
418 | /* Rule 15 is reserved. */ |
419 | |
420 | /* |
421 | * Last resort: just keep the current candidate. |
422 | * Or, do we need more rules? |
423 | */ |
424 | continue; |
425 | |
426 | replace: |
427 | ia_best = ia; |
428 | best_scope = (new_scope >= 0 ? new_scope : |
429 | in6_addrscope(&ia_best->ia_addr.sin6_addr)); |
430 | best_policy = (new_policy ? new_policy : |
431 | lookup_addrsel_policy(&ia_best->ia_addr)); |
432 | best_matchlen = (new_matchlen >= 0 ? new_matchlen : |
433 | in6_matchlen(&ia_best->ia_addr.sin6_addr, |
434 | dst)); |
435 | |
436 | next: |
437 | continue; |
438 | |
439 | out: |
440 | break; |
441 | } |
442 | |
443 | return ia_best; |
444 | } |
445 | #undef REPLACE |
446 | #undef BREAK |
447 | #undef NEXT |
448 | |
449 | int |
450 | in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, |
451 | struct ip6_moptions *mopts, struct route *ro, struct in6_addr *laddr, |
452 | struct ifnet **ifpp, struct psref *psref, struct in6_addr *ret_ia6) |
453 | { |
454 | struct in6_addr dst; |
455 | struct ifnet *ifp = NULL; |
456 | struct in6_ifaddr *ia = NULL; |
457 | struct in6_pktinfo *pi = NULL; |
458 | u_int32_t odstzone; |
459 | int error; |
460 | #if defined(MIP6) && NMIP > 0 |
461 | u_int8_t ip6po_usecoa = 0; |
462 | #endif /* MIP6 && NMIP > 0 */ |
463 | struct psref local_psref; |
464 | int bound = curlwp_bind(); |
465 | #define PSREF (psref == NULL) ? &local_psref : psref |
466 | int s; |
467 | |
468 | KASSERT((ifpp != NULL && psref != NULL) || |
469 | (ifpp == NULL && psref == NULL)); |
470 | |
471 | dst = dstsock->sin6_addr; /* make a copy for local operation */ |
472 | if (ifpp) |
473 | *ifpp = NULL; |
474 | |
475 | /* |
476 | * Try to determine the outgoing interface for the given destination. |
477 | * We do this regardless of whether the socket is bound, since the |
478 | * caller may need this information as a side effect of the call |
479 | * to this function (e.g., for identifying the appropriate scope zone |
480 | * ID). |
481 | */ |
482 | error = in6_selectif(dstsock, opts, mopts, ro, &ifp, PSREF); |
483 | if (ifpp != NULL) |
484 | *ifpp = ifp; |
485 | |
486 | /* |
487 | * If the source address is explicitly specified by the caller, |
488 | * check if the requested source address is indeed a unicast address |
489 | * assigned to the node, and can be used as the packet's source |
490 | * address. If everything is okay, use the address as source. |
491 | */ |
492 | if (opts && (pi = opts->ip6po_pktinfo) && |
493 | !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { |
494 | struct sockaddr_in6 srcsock; |
495 | struct in6_ifaddr *ia6; |
496 | int _s; |
497 | struct ifaddr *ifa; |
498 | |
499 | /* |
500 | * Determine the appropriate zone id of the source based on |
501 | * the zone of the destination and the outgoing interface. |
502 | * If the specified address is ambiguous wrt the scope zone, |
503 | * the interface must be specified; otherwise, ifa_ifwithaddr() |
504 | * will fail matching the address. |
505 | */ |
506 | memset(&srcsock, 0, sizeof(srcsock)); |
507 | srcsock.sin6_family = AF_INET6; |
508 | srcsock.sin6_len = sizeof(srcsock); |
509 | srcsock.sin6_addr = pi->ipi6_addr; |
510 | if (ifp) { |
511 | error = in6_setscope(&srcsock.sin6_addr, ifp, NULL); |
512 | if (error != 0) |
513 | goto exit; |
514 | } |
515 | |
516 | _s = pserialize_read_enter(); |
517 | ifa = ifa_ifwithaddr(sin6tosa(&srcsock)); |
518 | if ((ia6 = ifatoia6(ifa)) == NULL || |
519 | ia6->ia6_flags & |
520 | (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY)) { |
521 | pserialize_read_exit(_s); |
522 | error = EADDRNOTAVAIL; |
523 | goto exit; |
524 | } |
525 | pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */ |
526 | if (ifpp) |
527 | *ifpp = ifp; |
528 | *ret_ia6 = ia6->ia_addr.sin6_addr; |
529 | pserialize_read_exit(_s); |
530 | goto exit; |
531 | } |
532 | |
533 | /* |
534 | * If the socket has already bound the source, just use it. We don't |
535 | * care at the moment whether in6_selectif() succeeded above, even |
536 | * though it would eventually cause an error. |
537 | */ |
538 | if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) { |
539 | *ret_ia6 = *laddr; |
540 | goto exit; |
541 | } |
542 | |
543 | /* |
544 | * The outgoing interface is crucial in the general selection procedure |
545 | * below. If it is not known at this point, we fail. |
546 | */ |
547 | if (ifp == NULL) |
548 | goto exit; |
549 | |
550 | /* |
551 | * If the address is not yet determined, choose the best one based on |
552 | * the outgoing interface and the destination address. |
553 | */ |
554 | |
555 | #if defined(MIP6) && NMIP > 0 |
556 | /* |
557 | * a caller can specify IP6PO_USECOA to not to use a home |
558 | * address. for example, the case that the neighbour |
559 | * unreachability detection to the global address. |
560 | */ |
561 | if (opts != NULL && |
562 | (opts->ip6po_flags & IP6PO_USECOA) != 0) { |
563 | ip6po_usecoa = 1; |
564 | } |
565 | #endif /* MIP6 && NMIP > 0 */ |
566 | |
567 | error = in6_setscope(&dst, ifp, &odstzone); |
568 | if (error != 0) |
569 | goto exit; |
570 | |
571 | s = pserialize_read_enter(); |
572 | |
573 | ia = in6_select_best_ia(dstsock, &dst, ifp, opts, odstzone); |
574 | if (ia == NULL) { |
575 | pserialize_read_exit(s); |
576 | error = EADDRNOTAVAIL; |
577 | goto exit; |
578 | } |
579 | *ret_ia6 = ia->ia_addr.sin6_addr; |
580 | |
581 | pserialize_read_exit(s); |
582 | exit: |
583 | if (ifpp == NULL) |
584 | if_put(ifp, PSREF); |
585 | curlwp_bindx(bound); |
586 | return error; |
587 | #undef PSREF |
588 | } |
589 | |
590 | int |
591 | in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, |
592 | struct route **ro, struct rtentry **retrt, bool count_discard) |
593 | { |
594 | int error = 0; |
595 | struct rtentry *rt = NULL; |
596 | union { |
597 | struct sockaddr dst; |
598 | struct sockaddr_in6 dst6; |
599 | } u; |
600 | |
601 | KASSERT(ro != NULL); |
602 | KASSERT(retrt != NULL); |
603 | |
604 | #if 0 |
605 | if (dstsock->sin6_addr.s6_addr32[0] == 0 && |
606 | dstsock->sin6_addr.s6_addr32[1] == 0 && |
607 | !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { |
608 | printf("in6_selectroute: strange destination %s\n" , |
609 | ip6_sprintf(&dstsock->sin6_addr)); |
610 | } else { |
611 | printf("in6_selectroute: destination = %s%%%d\n" , |
612 | ip6_sprintf(&dstsock->sin6_addr), |
613 | dstsock->sin6_scope_id); /* for debug */ |
614 | } |
615 | #endif |
616 | |
617 | /* |
618 | * If the next hop address for the packet is specified by the caller, |
619 | * use it as the gateway. |
620 | */ |
621 | if (opts && opts->ip6po_nexthop) { |
622 | struct route *ron; |
623 | struct sockaddr_in6 *sin6_next; |
624 | |
625 | sin6_next = satosin6(opts->ip6po_nexthop); |
626 | |
627 | /* at this moment, we only support AF_INET6 next hops */ |
628 | if (sin6_next->sin6_family != AF_INET6) { |
629 | error = EAFNOSUPPORT; /* or should we proceed? */ |
630 | goto done; |
631 | } |
632 | |
633 | /* |
634 | * If the next hop is an IPv6 address, then the node identified |
635 | * by that address must be a neighbor of the sending host. |
636 | */ |
637 | ron = &opts->ip6po_nextroute; |
638 | rt = rtcache_lookup(ron, sin6tosa(sin6_next)); |
639 | if (rt == NULL || (rt->rt_flags & RTF_GATEWAY) != 0 || |
640 | !nd6_is_addr_neighbor(sin6_next, rt->rt_ifp)) { |
641 | rtcache_free(ron); |
642 | if (rt != NULL && count_discard) |
643 | in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); |
644 | rt = NULL; |
645 | error = EHOSTUNREACH; |
646 | goto done; |
647 | } |
648 | *ro = ron; |
649 | |
650 | goto done; |
651 | } |
652 | |
653 | /* |
654 | * Use a cached route if it exists and is valid, else try to allocate |
655 | * a new one. Note that we should check the address family of the |
656 | * cached destination, in case of sharing the cache with IPv4. |
657 | */ |
658 | u.dst6 = *dstsock; |
659 | u.dst6.sin6_scope_id = 0; |
660 | rt = rtcache_lookup1(*ro, &u.dst, 1); |
661 | |
662 | if (rt == NULL) |
663 | error = EHOSTUNREACH; |
664 | |
665 | /* |
666 | * Check if the outgoing interface conflicts with |
667 | * the interface specified by ipi6_ifindex (if specified). |
668 | * Note that loopback interface is always okay. |
669 | * (this may happen when we are sending a packet to one of |
670 | * our own addresses.) |
671 | */ |
672 | if (opts && opts->ip6po_pktinfo && opts->ip6po_pktinfo->ipi6_ifindex) { |
673 | if (!(rt->rt_ifp->if_flags & IFF_LOOPBACK) && |
674 | rt->rt_ifp->if_index != opts->ip6po_pktinfo->ipi6_ifindex) { |
675 | if (rt != NULL && count_discard) |
676 | in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); |
677 | error = EHOSTUNREACH; |
678 | rt = NULL; |
679 | } |
680 | } |
681 | |
682 | done: |
683 | if (error == EHOSTUNREACH) |
684 | IP6_STATINC(IP6_STAT_NOROUTE); |
685 | *retrt = rt; |
686 | return error; |
687 | } |
688 | |
689 | static int |
690 | in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, |
691 | struct ip6_moptions *mopts, struct route *ro, struct ifnet **retifp, |
692 | struct psref *psref) |
693 | { |
694 | int error; |
695 | struct rtentry *rt = NULL; |
696 | struct in6_addr *dst; |
697 | struct in6_pktinfo *pi = NULL; |
698 | |
699 | KASSERT(retifp != NULL); |
700 | *retifp = NULL; |
701 | dst = &dstsock->sin6_addr; |
702 | |
703 | /* If the caller specify the outgoing interface explicitly, use it. */ |
704 | if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { |
705 | /* XXX boundary check is assumed to be already done. */ |
706 | *retifp = if_get_byindex(pi->ipi6_ifindex, psref); |
707 | if (*retifp != NULL) |
708 | return 0; |
709 | goto getroute; |
710 | } |
711 | |
712 | /* |
713 | * If the destination address is a multicast address and the outgoing |
714 | * interface for the address is specified by the caller, use it. |
715 | */ |
716 | if (IN6_IS_ADDR_MULTICAST(dst) && mopts != NULL) { |
717 | *retifp = if_get_byindex(mopts->im6o_multicast_if_index, psref); |
718 | if (*retifp != NULL) |
719 | return 0; /* we do not need a route for multicast. */ |
720 | } |
721 | |
722 | getroute: |
723 | error = in6_selectroute(dstsock, opts, &ro, &rt, false); |
724 | if (error != 0) |
725 | return error; |
726 | |
727 | *retifp = if_get_byindex(rt->rt_ifp->if_index, psref); |
728 | |
729 | /* |
730 | * do not use a rejected or black hole route. |
731 | * XXX: this check should be done in the L2 output routine. |
732 | * However, if we skipped this check here, we'd see the following |
733 | * scenario: |
734 | * - install a rejected route for a scoped address prefix |
735 | * (like fe80::/10) |
736 | * - send a packet to a destination that matches the scoped prefix, |
737 | * with ambiguity about the scope zone. |
738 | * - pick the outgoing interface from the route, and disambiguate the |
739 | * scope zone with the interface. |
740 | * - ip6_output() would try to get another route with the "new" |
741 | * destination, which may be valid. |
742 | * - we'd see no error on output. |
743 | * Although this may not be very harmful, it should still be confusing. |
744 | * We thus reject the case here. |
745 | */ |
746 | if ((rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) |
747 | return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); |
748 | |
749 | /* |
750 | * Adjust the "outgoing" interface. If we're going to loop the packet |
751 | * back to ourselves, the ifp would be the loopback interface. |
752 | * However, we'd rather know the interface associated to the |
753 | * destination address (which should probably be one of our own |
754 | * addresses.) |
755 | */ |
756 | if (rt->rt_ifa && rt->rt_ifa->ifa_ifp && |
757 | rt->rt_ifa->ifa_ifp != *retifp && |
758 | !if_is_deactivated(rt->rt_ifa->ifa_ifp)) { |
759 | if_put(*retifp, psref); |
760 | *retifp = rt->rt_ifa->ifa_ifp; |
761 | if_acquire_NOMPSAFE(*retifp, psref); |
762 | } |
763 | |
764 | return (0); |
765 | } |
766 | |
767 | /* |
768 | * Default hop limit selection. The precedence is as follows: |
769 | * 1. Hoplimit value specified via ioctl. |
770 | * 2. (If the outgoing interface is detected) the current |
771 | * hop limit of the interface specified by router advertisement. |
772 | * 3. The system default hoplimit. |
773 | */ |
774 | int |
775 | in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp) |
776 | { |
777 | if (in6p && in6p->in6p_hops >= 0) |
778 | return (in6p->in6p_hops); |
779 | else if (ifp) |
780 | return (ND_IFINFO(ifp)->chlim); |
781 | else |
782 | return (ip6_defhlim); |
783 | } |
784 | |
785 | int |
786 | in6_selecthlim_rt(struct in6pcb *in6p) |
787 | { |
788 | struct rtentry *rt; |
789 | |
790 | if (in6p == NULL) |
791 | return in6_selecthlim(in6p, NULL); |
792 | |
793 | rt = rtcache_validate(&in6p->in6p_route); |
794 | if (rt != NULL) |
795 | return in6_selecthlim(in6p, rt->rt_ifp); |
796 | else |
797 | return in6_selecthlim(in6p, NULL); |
798 | } |
799 | |
800 | /* |
801 | * Find an empty port and set it to the specified PCB. |
802 | */ |
803 | int |
804 | in6_pcbsetport(struct sockaddr_in6 *sin6, struct in6pcb *in6p, struct lwp *l) |
805 | { |
806 | struct socket *so = in6p->in6p_socket; |
807 | struct inpcbtable *table = in6p->in6p_table; |
808 | u_int16_t lport, *lastport; |
809 | enum kauth_network_req req; |
810 | int error = 0; |
811 | |
812 | if (in6p->in6p_flags & IN6P_LOWPORT) { |
813 | #ifndef IPNOPRIVPORTS |
814 | req = KAUTH_REQ_NETWORK_BIND_PRIVPORT; |
815 | #else |
816 | req = KAUTH_REQ_NETWORK_BIND_PORT; |
817 | #endif |
818 | lastport = &table->inpt_lastlow; |
819 | } else { |
820 | req = KAUTH_REQ_NETWORK_BIND_PORT; |
821 | |
822 | lastport = &table->inpt_lastport; |
823 | } |
824 | |
825 | /* XXX-kauth: KAUTH_REQ_NETWORK_BIND_AUTOASSIGN_{,PRIV}PORT */ |
826 | error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_BIND, req, so, |
827 | sin6, NULL); |
828 | if (error) |
829 | return (EACCES); |
830 | |
831 | /* |
832 | * Use RFC6056 randomized port selection |
833 | */ |
834 | error = portalgo_randport(&lport, &in6p->in6p_head, l->l_cred); |
835 | if (error) |
836 | return error; |
837 | |
838 | in6p->in6p_flags |= IN6P_ANONPORT; |
839 | *lastport = lport; |
840 | in6p->in6p_lport = htons(lport); |
841 | in6_pcbstate(in6p, IN6P_BOUND); |
842 | return (0); /* success */ |
843 | } |
844 | |
845 | void |
846 | addrsel_policy_init(void) |
847 | { |
848 | init_policy_queue(); |
849 | |
850 | /* initialize the "last resort" policy */ |
851 | memset(&defaultaddrpolicy, 0, sizeof(defaultaddrpolicy)); |
852 | defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; |
853 | } |
854 | |
855 | static struct in6_addrpolicy * |
856 | lookup_addrsel_policy(struct sockaddr_in6 *key) |
857 | { |
858 | struct in6_addrpolicy *match = NULL; |
859 | |
860 | match = match_addrsel_policy(key); |
861 | |
862 | if (match == NULL) |
863 | match = &defaultaddrpolicy; |
864 | else |
865 | match->use++; |
866 | |
867 | return (match); |
868 | } |
869 | |
870 | /* |
871 | * Subroutines to manage the address selection policy table via sysctl. |
872 | */ |
873 | struct sel_walkarg { |
874 | size_t w_total; |
875 | size_t w_given; |
876 | void * w_where; |
877 | void *w_limit; |
878 | }; |
879 | |
880 | int sysctl_net_inet6_addrctlpolicy(SYSCTLFN_ARGS); |
881 | int |
882 | sysctl_net_inet6_addrctlpolicy(SYSCTLFN_ARGS) |
883 | { |
884 | int error = 0; |
885 | int s; |
886 | |
887 | s = splsoftnet(); |
888 | |
889 | if (newp) { |
890 | error = EPERM; |
891 | goto end; |
892 | } |
893 | if (oldp && oldlenp == NULL) { |
894 | error = EINVAL; |
895 | goto end; |
896 | } |
897 | if (oldp || oldlenp) { |
898 | struct sel_walkarg w; |
899 | size_t oldlen = *oldlenp; |
900 | |
901 | memset(&w, 0, sizeof(w)); |
902 | w.w_given = oldlen; |
903 | w.w_where = oldp; |
904 | if (oldp) |
905 | w.w_limit = (char *)oldp + oldlen; |
906 | |
907 | error = walk_addrsel_policy(dump_addrsel_policyent, &w); |
908 | |
909 | *oldlenp = w.w_total; |
910 | if (oldp && w.w_total > oldlen && error == 0) |
911 | error = ENOMEM; |
912 | } |
913 | |
914 | end: |
915 | splx(s); |
916 | |
917 | return (error); |
918 | } |
919 | |
920 | int |
921 | in6_src_ioctl(u_long cmd, void *data) |
922 | { |
923 | int i; |
924 | struct in6_addrpolicy ent0; |
925 | |
926 | if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) |
927 | return (EOPNOTSUPP); /* check for safety */ |
928 | |
929 | ent0 = *(struct in6_addrpolicy *)data; |
930 | |
931 | if (ent0.label == ADDR_LABEL_NOTAPP) |
932 | return (EINVAL); |
933 | /* check if the prefix mask is consecutive. */ |
934 | if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) |
935 | return (EINVAL); |
936 | /* clear trailing garbages (if any) of the prefix address. */ |
937 | for (i = 0; i < 4; i++) { |
938 | ent0.addr.sin6_addr.s6_addr32[i] &= |
939 | ent0.addrmask.sin6_addr.s6_addr32[i]; |
940 | } |
941 | ent0.use = 0; |
942 | |
943 | switch (cmd) { |
944 | case SIOCAADDRCTL_POLICY: |
945 | return (add_addrsel_policyent(&ent0)); |
946 | case SIOCDADDRCTL_POLICY: |
947 | return (delete_addrsel_policyent(&ent0)); |
948 | } |
949 | |
950 | return (0); /* XXX: compromise compilers */ |
951 | } |
952 | |
953 | /* |
954 | * The followings are implementation of the policy table using a |
955 | * simple tail queue. |
956 | * XXX such details should be hidden. |
957 | * XXX implementation using binary tree should be more efficient. |
958 | */ |
959 | struct addrsel_policyent { |
960 | TAILQ_ENTRY(addrsel_policyent) ape_entry; |
961 | struct in6_addrpolicy ape_policy; |
962 | }; |
963 | |
964 | TAILQ_HEAD(addrsel_policyhead, addrsel_policyent); |
965 | |
966 | struct addrsel_policyhead addrsel_policytab; |
967 | |
968 | static void |
969 | init_policy_queue(void) |
970 | { |
971 | TAILQ_INIT(&addrsel_policytab); |
972 | } |
973 | |
974 | static int |
975 | add_addrsel_policyent(struct in6_addrpolicy *newpolicy) |
976 | { |
977 | struct addrsel_policyent *newpol, *pol; |
978 | |
979 | /* duplication check */ |
980 | TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) { |
981 | if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr, |
982 | &pol->ape_policy.addr.sin6_addr) && |
983 | IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr, |
984 | &pol->ape_policy.addrmask.sin6_addr)) { |
985 | return (EEXIST); /* or override it? */ |
986 | } |
987 | } |
988 | |
989 | newpol = malloc(sizeof(*newpol), M_IFADDR, M_WAITOK|M_ZERO); |
990 | |
991 | /* XXX: should validate entry */ |
992 | newpol->ape_policy = *newpolicy; |
993 | |
994 | TAILQ_INSERT_TAIL(&addrsel_policytab, newpol, ape_entry); |
995 | |
996 | return (0); |
997 | } |
998 | |
999 | static int |
1000 | delete_addrsel_policyent(struct in6_addrpolicy *key) |
1001 | { |
1002 | struct addrsel_policyent *pol; |
1003 | |
1004 | /* search for the entry in the table */ |
1005 | for (pol = TAILQ_FIRST(&addrsel_policytab); pol; |
1006 | pol = TAILQ_NEXT(pol, ape_entry)) { |
1007 | if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr, |
1008 | &pol->ape_policy.addr.sin6_addr) && |
1009 | IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr, |
1010 | &pol->ape_policy.addrmask.sin6_addr)) { |
1011 | break; |
1012 | } |
1013 | } |
1014 | if (pol == NULL) { |
1015 | return (ESRCH); |
1016 | } |
1017 | |
1018 | TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry); |
1019 | |
1020 | return (0); |
1021 | } |
1022 | |
1023 | static int |
1024 | walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w) |
1025 | { |
1026 | struct addrsel_policyent *pol; |
1027 | int error = 0; |
1028 | |
1029 | TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) { |
1030 | if ((error = (*callback)(&pol->ape_policy, w)) != 0) |
1031 | return error; |
1032 | } |
1033 | |
1034 | return error; |
1035 | } |
1036 | |
1037 | static int |
1038 | dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg) |
1039 | { |
1040 | int error = 0; |
1041 | struct sel_walkarg *w = arg; |
1042 | |
1043 | if (w->w_where && (char *)w->w_where + sizeof(*pol) <= (char *)w->w_limit) { |
1044 | if ((error = copyout(pol, w->w_where, sizeof(*pol))) != 0) |
1045 | return error; |
1046 | w->w_where = (char *)w->w_where + sizeof(*pol); |
1047 | } |
1048 | w->w_total += sizeof(*pol); |
1049 | |
1050 | return error; |
1051 | } |
1052 | |
1053 | static struct in6_addrpolicy * |
1054 | match_addrsel_policy(struct sockaddr_in6 *key) |
1055 | { |
1056 | struct addrsel_policyent *pent; |
1057 | struct in6_addrpolicy *bestpol = NULL, *pol; |
1058 | int matchlen, bestmatchlen = -1; |
1059 | u_char *mp, *ep, *k, *p, m; |
1060 | |
1061 | for (pent = TAILQ_FIRST(&addrsel_policytab); pent; |
1062 | pent = TAILQ_NEXT(pent, ape_entry)) { |
1063 | matchlen = 0; |
1064 | |
1065 | pol = &pent->ape_policy; |
1066 | mp = (u_char *)&pol->addrmask.sin6_addr; |
1067 | ep = mp + 16; /* XXX: scope field? */ |
1068 | k = (u_char *)&key->sin6_addr; |
1069 | p = (u_char *)&pol->addr.sin6_addr; |
1070 | for (; mp < ep && *mp; mp++, k++, p++) { |
1071 | m = *mp; |
1072 | if ((*k & m) != *p) |
1073 | goto next; /* not match */ |
1074 | if (m == 0xff) /* short cut for a typical case */ |
1075 | matchlen += 8; |
1076 | else { |
1077 | while (m >= 0x80) { |
1078 | matchlen++; |
1079 | m <<= 1; |
1080 | } |
1081 | } |
1082 | } |
1083 | |
1084 | /* matched. check if this is better than the current best. */ |
1085 | if (bestpol == NULL || |
1086 | matchlen > bestmatchlen) { |
1087 | bestpol = pol; |
1088 | bestmatchlen = matchlen; |
1089 | } |
1090 | |
1091 | next: |
1092 | continue; |
1093 | } |
1094 | |
1095 | return (bestpol); |
1096 | } |
1097 | |