2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * $KAME: in6_src.c,v 1.132 2003/08/26 04:42:27 keiichi Exp $
35 * Copyright (c) 1982, 1986, 1991, 1993
36 * The Regents of the University of California. All rights reserved.
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
41 * 1. Redistributions of source code must retain the above copyright
42 * notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 * notice, this list of conditions and the following disclaimer in the
45 * documentation and/or other materials provided with the distribution.
46 * 3. Neither the name of the University nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
65 #include <sys/cdefs.h>
66 __FBSDID("$FreeBSD$");
69 #include "opt_inet6.h"
70 #include <sys/param.h>
71 #include <sys/systm.h>
73 #include <sys/malloc.h>
76 #include <sys/protosw.h>
77 #include <sys/socket.h>
78 #include <sys/socketvar.h>
79 #include <sys/sockio.h>
80 #include <sys/sysctl.h>
81 #include <sys/errno.h>
84 #include <sys/kernel.h>
85 #include <sys/rmlock.h>
89 #include <net/if_var.h>
90 #include <net/if_dl.h>
91 #include <net/route.h>
92 #include <net/route/nhop.h>
93 #include <net/if_llatbl.h>
95 #include <netinet/in.h>
96 #include <netinet/in_var.h>
97 #include <netinet/in_systm.h>
98 #include <netinet/ip.h>
99 #include <netinet/in_pcb.h>
100 #include <netinet/ip_var.h>
101 #include <netinet/udp.h>
102 #include <netinet/udp_var.h>
104 #include <netinet6/in6_var.h>
105 #include <netinet/ip6.h>
106 #include <netinet6/in6_fib.h>
107 #include <netinet6/in6_pcb.h>
108 #include <netinet6/ip6_var.h>
109 #include <netinet6/scope6_var.h>
110 #include <netinet6/nd6.h>
112 static struct mtx addrsel_lock;
113 #define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF)
114 #define ADDRSEL_LOCK() mtx_lock(&addrsel_lock)
115 #define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock)
116 #define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED)
118 static struct sx addrsel_sxlock;
119 #define ADDRSEL_SXLOCK_INIT() sx_init(&addrsel_sxlock, "addrsel_sxlock")
120 #define ADDRSEL_SLOCK() sx_slock(&addrsel_sxlock)
121 #define ADDRSEL_SUNLOCK() sx_sunlock(&addrsel_sxlock)
122 #define ADDRSEL_XLOCK() sx_xlock(&addrsel_sxlock)
123 #define ADDRSEL_XUNLOCK() sx_xunlock(&addrsel_sxlock)
125 #define ADDR_LABEL_NOTAPP (-1)
126 VNET_DEFINE_STATIC(struct in6_addrpolicy, defaultaddrpolicy);
127 #define V_defaultaddrpolicy VNET(defaultaddrpolicy)
129 VNET_DEFINE(int, ip6_prefer_tempaddr) = 0;
131 static int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *,
132 struct ip6_moptions *, struct route_in6 *, struct ifnet **,
133 struct nhop_object **, int, u_int, uint32_t);
134 static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *,
135 struct ip6_moptions *, struct ifnet **,
136 struct ifnet *, u_int);
137 static int in6_selectsrc(uint32_t, struct sockaddr_in6 *,
138 struct ip6_pktopts *, struct inpcb *, struct ucred *,
139 struct ifnet **, struct in6_addr *);
141 static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *);
143 static void init_policy_queue(void);
144 static int add_addrsel_policyent(struct in6_addrpolicy *);
145 static int delete_addrsel_policyent(struct in6_addrpolicy *);
146 static int walk_addrsel_policy(int (*)(struct in6_addrpolicy *, void *),
148 static int dump_addrsel_policyent(struct in6_addrpolicy *, void *);
149 static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *);
152 * Return an IPv6 address, which is the most appropriate for a given
153 * destination and user specified options.
154 * If necessary, this function lookups the routing table and returns
155 * an entry to the caller for later use.
157 #define REPLACE(r) do {\
158 IP6STAT_INC(ip6s_sources_rule[(r)]); \
160 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \
161 printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \
165 #define NEXT(r) do {\
167 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \
168 printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \
170 goto next; /* XXX: we can't use 'continue' here */ \
172 #define BREAK(r) do { \
173 IP6STAT_INC(ip6s_sources_rule[(r)]); \
174 goto out; /* XXX: we can't use 'break' here */ \
178 in6_selectsrc(uint32_t fibnum, struct sockaddr_in6 *dstsock,
179 struct ip6_pktopts *opts, struct inpcb *inp, struct ucred *cred,
180 struct ifnet **ifpp, struct in6_addr *srcp)
182 struct rm_priotracker in6_ifa_tracker;
183 struct in6_addr dst, tmp;
184 struct ifnet *ifp = NULL, *oifp = NULL;
185 struct in6_ifaddr *ia = NULL, *ia_best = NULL;
186 struct in6_pktinfo *pi = NULL;
187 int dst_scope = -1, best_scope = -1, best_matchlen = -1;
188 struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
192 struct ip6_moptions *mopts;
195 KASSERT(srcp != NULL, ("%s: srcp is NULL", __func__));
197 dst = dstsock->sin6_addr; /* make a copy for local operation */
200 * Save a possibly passed in ifp for in6_selectsrc. Only
201 * neighbor discovery code should use this feature, where
202 * we may know the interface but not the FIB number holding
203 * the connected subnet in case someone deleted it from the
204 * default FIB and we need to check the interface.
212 INP_LOCK_ASSERT(inp);
213 mopts = inp->in6p_moptions;
219 * If the source address is explicitly specified by the caller,
220 * check if the requested source address is indeed a unicast address
221 * assigned to the node, and can be used as the packet's source
222 * address. If everything is okay, use the address as source.
224 if (opts && (pi = opts->ip6po_pktinfo) &&
225 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) {
226 /* get the outgoing interface */
227 if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp,
233 * determine the appropriate zone id of the source based on
234 * the zone of the destination and the outgoing interface.
235 * If the specified address is ambiguous wrt the scope zone,
236 * the interface must be specified; otherwise, ifa_ifwithaddr()
237 * will fail matching the address.
241 error = in6_setscope(&tmp, ifp, &odstzone);
245 if (cred != NULL && (error = prison_local_ip6(cred,
246 &tmp, (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0)
250 * If IPV6_BINDANY socket option is set, we allow to specify
251 * non local addresses as source address in IPV6_PKTINFO
254 if ((inp->inp_flags & INP_BINDANY) == 0) {
255 ia = in6ifa_ifwithaddr(&tmp, 0 /* XXX */, false);
256 if (ia == NULL || (ia->ia6_flags & (IN6_IFF_ANYCAST |
258 return (EADDRNOTAVAIL);
259 bcopy(&ia->ia_addr.sin6_addr, srcp, sizeof(*srcp));
261 bcopy(&tmp, srcp, sizeof(*srcp));
262 pi->ipi6_addr = tmp; /* XXX: this overrides pi */
269 * Otherwise, if the socket has already bound the source, just use it.
271 if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
273 (error = prison_local_ip6(cred, &inp->in6p_laddr,
274 ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0)
276 bcopy(&inp->in6p_laddr, srcp, sizeof(*srcp));
281 * Bypass source address selection and use the primary jail IP
284 if (cred != NULL && !prison_saddrsel_ip6(cred, srcp))
288 * If the address is not specified, choose the best one based on
289 * the outgoing interface and the destination address.
291 /* get the outgoing interface */
292 if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp,
293 (inp != NULL) ? inp->inp_inc.inc_fibnum : fibnum)) != 0)
297 if (ifp == NULL) /* this should not happen */
298 panic("in6_selectsrc: NULL ifp");
300 error = in6_setscope(&dst, ifp, &odstzone);
304 IN6_IFADDR_RLOCK(&in6_ifa_tracker);
305 CK_STAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
306 int new_scope = -1, new_matchlen = -1;
307 struct in6_addrpolicy *new_policy = NULL;
308 u_int32_t srczone, osrczone, dstzone;
310 struct ifnet *ifp1 = ia->ia_ifp;
313 * We'll never take an address that breaks the scope zone
314 * of the destination. We also skip an address if its zone
315 * does not contain the outgoing interface.
316 * XXX: we should probably use sin6_scope_id here.
318 if (in6_setscope(&dst, ifp1, &dstzone) ||
319 odstzone != dstzone) {
322 src = ia->ia_addr.sin6_addr;
323 if (in6_setscope(&src, ifp, &osrczone) ||
324 in6_setscope(&src, ifp1, &srczone) ||
325 osrczone != srczone) {
329 /* avoid unusable addresses */
331 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) {
334 if (!V_ip6_use_deprecated && IFA6_IS_DEPRECATED(ia))
337 /* If jailed only take addresses of the jail into account. */
339 prison_check_ip6(cred, &ia->ia_addr.sin6_addr) != 0)
342 /* Rule 1: Prefer same address */
343 if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) {
345 BREAK(1); /* there should be no better candidate */
351 /* Rule 2: Prefer appropriate scope */
353 dst_scope = in6_addrscope(&dst);
354 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr);
355 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) {
356 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0)
359 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) {
360 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0)
366 * Rule 3: Avoid deprecated addresses. Note that the case of
367 * !ip6_use_deprecated is already rejected above.
369 if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia))
371 if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia))
374 /* Rule 4: Prefer home addresses */
376 * XXX: This is a TODO. We should probably merge the MIP6
380 /* Rule 5: Prefer outgoing interface */
381 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_NO_PREFER_IFACE)) {
382 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp)
384 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp)
389 * Rule 6: Prefer matching label
390 * Note that best_policy should be non-NULL here.
392 if (dst_policy == NULL)
393 dst_policy = lookup_addrsel_policy(dstsock);
394 if (dst_policy->label != ADDR_LABEL_NOTAPP) {
395 new_policy = lookup_addrsel_policy(&ia->ia_addr);
396 if (dst_policy->label == best_policy->label &&
397 dst_policy->label != new_policy->label)
399 if (dst_policy->label != best_policy->label &&
400 dst_policy->label == new_policy->label)
405 * Rule 7: Prefer public addresses.
406 * We allow users to reverse the logic by configuring
407 * a sysctl variable, so that privacy conscious users can
408 * always prefer temporary addresses.
411 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) {
412 prefer_tempaddr = V_ip6_prefer_tempaddr;
413 } else if (opts->ip6po_prefer_tempaddr ==
414 IP6PO_TEMPADDR_NOTPREFER) {
418 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
419 (ia->ia6_flags & IN6_IFF_TEMPORARY)) {
425 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
426 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
434 * Rule 8: prefer addresses on alive interfaces.
435 * This is a KAME specific rule.
437 if ((ia_best->ia_ifp->if_flags & IFF_UP) &&
438 !(ia->ia_ifp->if_flags & IFF_UP))
440 if (!(ia_best->ia_ifp->if_flags & IFF_UP) &&
441 (ia->ia_ifp->if_flags & IFF_UP))
445 * Rule 9: prefer address with better virtual status.
447 if (ifa_preferred(&ia_best->ia_ifa, &ia->ia_ifa))
449 if (ifa_preferred(&ia->ia_ifa, &ia_best->ia_ifa))
453 * Rule 10: prefer address with `prefer_source' flag.
455 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0 &&
456 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0)
458 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0 &&
459 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0)
463 * Rule 14: Use longest matching prefix.
464 * Note: in the address selection draft, this rule is
465 * documented as "Rule 8". However, since it is also
466 * documented that this rule can be overridden, we assign
467 * a large number so that it is easy to assign smaller numbers
468 * to more preferred rules.
470 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst);
471 if (best_matchlen < new_matchlen)
473 if (new_matchlen < best_matchlen)
476 /* Rule 15 is reserved. */
479 * Last resort: just keep the current candidate.
480 * Or, do we need more rules?
486 best_scope = (new_scope >= 0 ? new_scope :
487 in6_addrscope(&ia_best->ia_addr.sin6_addr));
488 best_policy = (new_policy ? new_policy :
489 lookup_addrsel_policy(&ia_best->ia_addr));
490 best_matchlen = (new_matchlen >= 0 ? new_matchlen :
491 in6_matchlen(&ia_best->ia_addr.sin6_addr,
501 if ((ia = ia_best) == NULL) {
502 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
503 IP6STAT_INC(ip6s_sources_none);
504 return (EADDRNOTAVAIL);
508 * At this point at least one of the addresses belonged to the jail
509 * but it could still be, that we want to further restrict it, e.g.
510 * theoratically IN6_IS_ADDR_LOOPBACK.
511 * It must not be IN6_IS_ADDR_UNSPECIFIED anymore.
512 * prison_local_ip6() will fix an IN6_IS_ADDR_LOOPBACK but should
513 * let all others previously selected pass.
514 * Use tmp to not change ::1 on lo0 to the primary jail address.
516 tmp = ia->ia_addr.sin6_addr;
517 if (cred != NULL && prison_local_ip6(cred, &tmp, (inp != NULL &&
518 (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) {
519 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
520 IP6STAT_INC(ip6s_sources_none);
521 return (EADDRNOTAVAIL);
527 bcopy(&tmp, srcp, sizeof(*srcp));
528 if (ia->ia_ifp == ifp)
529 IP6STAT_INC(ip6s_sources_sameif[best_scope]);
531 IP6STAT_INC(ip6s_sources_otherif[best_scope]);
532 if (dst_scope == best_scope)
533 IP6STAT_INC(ip6s_sources_samescope[best_scope]);
535 IP6STAT_INC(ip6s_sources_otherscope[best_scope]);
536 if (IFA6_IS_DEPRECATED(ia))
537 IP6STAT_INC(ip6s_sources_deprecated[best_scope]);
538 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
543 * Select source address based on @inp, @dstsock and @opts.
544 * Stores selected address to @srcp. If @scope_ambiguous is set,
545 * embed scope from selected outgoing interface. If @hlim pointer
546 * is provided, stores calculated hop limit there.
547 * Returns 0 on success.
550 in6_selectsrc_socket(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
551 struct inpcb *inp, struct ucred *cred, int scope_ambiguous,
552 struct in6_addr *srcp, int *hlim)
554 struct ifnet *retifp;
558 fibnum = inp->inp_inc.inc_fibnum;
561 error = in6_selectsrc(fibnum, dstsock, opts, inp, cred, &retifp, srcp);
566 *hlim = in6_selecthlim(inp, retifp);
568 if (retifp == NULL || scope_ambiguous == 0)
572 * Application should provide a proper zone ID or the use of
573 * default zone IDs should be enabled. Unfortunately, some
574 * applications do not behave as it should, so we need a
575 * workaround. Even if an appropriate ID is not determined
576 * (when it's required), if we can determine the outgoing
577 * interface. determine the zone ID based on the interface.
579 error = in6_setscope(&dstsock->sin6_addr, retifp, NULL);
585 * Select source address based on @fibnum, @dst and @scopeid.
586 * Stores selected address to @srcp.
587 * Returns 0 on success.
589 * Used by non-socket based consumers (ND code mostly)
592 in6_selectsrc_addr(uint32_t fibnum, const struct in6_addr *dst,
593 uint32_t scopeid, struct ifnet *ifp, struct in6_addr *srcp,
596 struct ifnet *retifp;
597 struct sockaddr_in6 dst_sa;
601 bzero(&dst_sa, sizeof(dst_sa));
602 dst_sa.sin6_family = AF_INET6;
603 dst_sa.sin6_len = sizeof(dst_sa);
604 dst_sa.sin6_addr = *dst;
605 dst_sa.sin6_scope_id = scopeid;
606 sa6_embedscope(&dst_sa, 0);
608 error = in6_selectsrc(fibnum, &dst_sa, NULL, NULL, NULL, &retifp, srcp);
610 *hlim = in6_selecthlim(NULL, retifp);
615 static struct nhop_object *
616 cache_route(uint32_t fibnum, const struct sockaddr_in6 *dst, struct route_in6 *ro,
620 * Use a cached route if it exists and is valid, else try to allocate
621 * a new one. Note that we should check the address family of the
622 * cached destination, in case of sharing the cache with IPv4.
623 * Assumes that 'struct route_in6' is exclusively locked.
625 if (ro->ro_nh != NULL && (
626 !NH_IS_VALID(ro->ro_nh) || ro->ro_dst.sin6_family != AF_INET6 ||
627 !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &dst->sin6_addr)))
630 if (ro->ro_nh == NULL) {
633 const struct in6_addr *paddr;
634 struct in6_addr unscoped_addr;
635 uint32_t scopeid = 0;
636 if (IN6_IS_SCOPE_LINKLOCAL(&dst->sin6_addr)) {
637 in6_splitscope(&dst->sin6_addr, &unscoped_addr, &scopeid);
638 paddr = &unscoped_addr;
640 paddr = &dst->sin6_addr;
641 ro->ro_nh = fib6_lookup(fibnum, paddr, scopeid, NHR_REF, flowid);
646 static struct nhop_object *
647 lookup_route(uint32_t fibnum, struct sockaddr_in6 *dst, struct route_in6 *ro,
648 struct ip6_pktopts *opts, uint32_t flowid)
650 struct nhop_object *nh = NULL;
653 * If the next hop address for the packet is specified by the caller,
654 * use it as the gateway.
656 if (opts && opts->ip6po_nexthop) {
657 struct route_in6 *ron = &opts->ip6po_nextroute;
658 struct sockaddr_in6 *sin6_next = satosin6(opts->ip6po_nexthop);
660 nh = cache_route(fibnum, sin6_next, ron, flowid);
663 * The node identified by that address must be a
664 * neighbor of the sending host.
666 if (nh != NULL && (nh->nh_flags & NHF_GATEWAY) != 0)
668 } else if (ro != NULL) {
669 nh = cache_route(fibnum, dst, ro, flowid);
674 * Check if the outgoing interface conflicts with
675 * the interface specified by ipi6_ifindex (if specified).
677 struct in6_pktinfo *pi;
678 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) {
679 if (nh->nh_aifp->if_index != pi->ipi6_ifindex)
688 * Finds outgoing nexthop or the outgoing interface for the
690 * Return 0 on success and stores the lookup result in @retnh and @retifp
693 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
694 struct ip6_moptions *mopts, struct route_in6 *ro,
695 struct ifnet **retifp, struct nhop_object **retnh, int norouteok,
696 u_int fibnum, uint32_t flowid)
699 struct ifnet *ifp = NULL;
700 struct in6_pktinfo *pi = NULL;
701 struct in6_addr *dst = &dstsock->sin6_addr;
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 ifp = ifnet_byindex(pi->ipi6_ifindex);
707 if (ifp != NULL && (norouteok || IN6_IS_ADDR_MULTICAST(dst))) {
709 * we do not have to check or get the route for
717 * If the destination address is a multicast address and the outgoing
718 * interface for the address is specified by the caller, use it.
720 if (IN6_IS_ADDR_MULTICAST(dst) &&
721 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) {
722 goto done; /* we do not need a route for multicast. */
725 * If destination address is LLA or link- or node-local multicast,
726 * use it's embedded scope zone id to determine outgoing interface.
728 if (IN6_IS_ADDR_MC_LINKLOCAL(dst) ||
729 IN6_IS_ADDR_MC_NODELOCAL(dst)) {
730 uint32_t zoneid = ntohs(in6_getscope(dst));
732 ifp = in6_getlinkifnet(zoneid);
738 struct nhop_object *nh = lookup_route(fibnum, dstsock, ro, opts, flowid);
740 *retifp = nh->nh_aifp;
744 IP6STAT_INC(ip6s_noroute);
745 error = EHOSTUNREACH;
753 * This can happen if the caller did not pass a cached route
754 * nor any other hints. We treat this case an error.
756 error = EHOSTUNREACH;
758 if (error == EHOSTUNREACH)
759 IP6STAT_INC(ip6s_noroute);
768 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
769 struct ip6_moptions *mopts, struct ifnet **retifp,
770 struct ifnet *oifp, u_int fibnum)
773 struct route_in6 sro;
774 struct nhop_object *nh = NULL;
777 KASSERT(retifp != NULL, ("%s: retifp is NULL", __func__));
779 bzero(&sro, sizeof(sro));
782 error = selectroute(dstsock, opts, mopts, &sro, retifp, &nh, 1, fibnum, 0);
785 nh_flags = nh->nh_flags;
786 if (nh != NULL && nh == sro.ro_nh)
790 /* Help ND. See oifp comment in in6_selectsrc(). */
791 if (oifp != NULL && fibnum == RT_DEFAULT_FIB) {
799 * do not use a rejected or black hole route.
800 * XXX: this check should be done in the L2 output routine.
801 * However, if we skipped this check here, we'd see the following
803 * - install a rejected route for a scoped address prefix
805 * - send a packet to a destination that matches the scoped prefix,
806 * with ambiguity about the scope zone.
807 * - pick the outgoing interface from the route, and disambiguate the
808 * scope zone with the interface.
809 * - ip6_output() would try to get another route with the "new"
810 * destination, which may be valid.
811 * - we'd see no error on output.
812 * Although this may not be very harmful, it should still be confusing.
813 * We thus reject the case here.
816 if (nh_flags & (NHF_REJECT | NHF_BLACKHOLE)) {
817 error = (nh_flags & NHF_HOST ? EHOSTUNREACH : ENETUNREACH);
824 /* Public wrapper function to selectroute(). */
826 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
827 struct ip6_moptions *mopts, struct route_in6 *ro,
828 struct ifnet **retifp, struct nhop_object **retnh, u_int fibnum, uint32_t flowid)
830 MPASS(retifp != NULL);
831 MPASS(retnh != NULL);
833 return (selectroute(dstsock, opts, mopts, ro, retifp,
834 retnh, 0, fibnum, flowid));
838 * Default hop limit selection. The precedence is as follows:
839 * 1. Hoplimit value specified via ioctl.
840 * 2. (If the outgoing interface is detected) the current
841 * hop limit of the interface specified by router advertisement.
842 * 3. The system default hoplimit.
845 in6_selecthlim(struct inpcb *inp, struct ifnet *ifp)
848 if (inp && inp->in6p_hops >= 0)
849 return (inp->in6p_hops);
851 return (ND_IFINFO(ifp)->chlim);
852 else if (inp && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
853 struct nhop_object *nh;
855 uint32_t fibnum, scopeid;
858 fibnum = inp->inp_inc.inc_fibnum;
859 in6_splitscope(&inp->in6p_faddr, &dst, &scopeid);
860 nh = fib6_lookup(fibnum, &dst, scopeid, 0, 0);
862 hlim = ND_IFINFO(nh->nh_ifp)->chlim;
866 return (V_ip6_defhlim);
870 addrsel_policy_init(void)
875 /* initialize the "last resort" policy */
876 bzero(&V_defaultaddrpolicy, sizeof(V_defaultaddrpolicy));
877 V_defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
879 if (!IS_DEFAULT_VNET(curvnet))
883 ADDRSEL_SXLOCK_INIT();
886 static struct in6_addrpolicy *
887 lookup_addrsel_policy(struct sockaddr_in6 *key)
889 struct in6_addrpolicy *match = NULL;
892 match = match_addrsel_policy(key);
895 match = &V_defaultaddrpolicy;
904 * Subroutines to manage the address selection policy table via sysctl.
907 struct sysctl_req *w_req;
910 static int in6_src_sysctl(SYSCTL_HANDLER_ARGS);
911 SYSCTL_DECL(_net_inet6_ip6);
912 static SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy,
913 CTLFLAG_RD | CTLFLAG_MPSAFE, in6_src_sysctl,
917 in6_src_sysctl(SYSCTL_HANDLER_ARGS)
924 bzero(&w, sizeof(w));
927 return (walk_addrsel_policy(dump_addrsel_policyent, &w));
931 in6_src_ioctl(u_long cmd, caddr_t data)
933 struct in6_addrpolicy ent0;
935 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY)
936 return (EOPNOTSUPP); /* check for safety */
938 ent0 = *(struct in6_addrpolicy *)data;
940 if (ent0.label == ADDR_LABEL_NOTAPP)
942 /* check if the prefix mask is consecutive. */
943 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0)
945 /* clear trailing garbages (if any) of the prefix address. */
946 IN6_MASK_ADDR(&ent0.addr.sin6_addr, &ent0.addrmask.sin6_addr);
950 case SIOCAADDRCTL_POLICY:
951 return (add_addrsel_policyent(&ent0));
952 case SIOCDADDRCTL_POLICY:
953 return (delete_addrsel_policyent(&ent0));
956 return (0); /* XXX: compromise compilers */
960 * The followings are implementation of the policy table using a
962 * XXX such details should be hidden.
963 * XXX implementation using binary tree should be more efficient.
965 struct addrsel_policyent {
966 TAILQ_ENTRY(addrsel_policyent) ape_entry;
967 struct in6_addrpolicy ape_policy;
970 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent);
972 VNET_DEFINE_STATIC(struct addrsel_policyhead, addrsel_policytab);
973 #define V_addrsel_policytab VNET(addrsel_policytab)
976 init_policy_queue(void)
979 TAILQ_INIT(&V_addrsel_policytab);
983 add_addrsel_policyent(struct in6_addrpolicy *newpolicy)
985 struct addrsel_policyent *new, *pol;
987 new = malloc(sizeof(*new), M_IFADDR,
992 /* duplication check */
993 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
994 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr,
995 &pol->ape_policy.addr.sin6_addr) &&
996 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr,
997 &pol->ape_policy.addrmask.sin6_addr)) {
1000 free(new, M_IFADDR);
1001 return (EEXIST); /* or override it? */
1005 bzero(new, sizeof(*new));
1007 /* XXX: should validate entry */
1008 new->ape_policy = *newpolicy;
1010 TAILQ_INSERT_TAIL(&V_addrsel_policytab, new, ape_entry);
1018 delete_addrsel_policyent(struct in6_addrpolicy *key)
1020 struct addrsel_policyent *pol;
1025 /* search for the entry in the table */
1026 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
1027 if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr,
1028 &pol->ape_policy.addr.sin6_addr) &&
1029 IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr,
1030 &pol->ape_policy.addrmask.sin6_addr)) {
1040 TAILQ_REMOVE(&V_addrsel_policytab, pol, ape_entry);
1043 free(pol, M_IFADDR);
1049 walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w)
1051 struct addrsel_policyent *pol;
1055 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
1056 if ((error = (*callback)(&pol->ape_policy, w)) != 0) {
1066 dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg)
1069 struct walkarg *w = arg;
1071 error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol));
1076 static struct in6_addrpolicy *
1077 match_addrsel_policy(struct sockaddr_in6 *key)
1079 struct addrsel_policyent *pent;
1080 struct in6_addrpolicy *bestpol = NULL, *pol;
1081 int matchlen, bestmatchlen = -1;
1082 u_char *mp, *ep, *k, *p, m;
1084 TAILQ_FOREACH(pent, &V_addrsel_policytab, ape_entry) {
1087 pol = &pent->ape_policy;
1088 mp = (u_char *)&pol->addrmask.sin6_addr;
1089 ep = mp + 16; /* XXX: scope field? */
1090 k = (u_char *)&key->sin6_addr;
1091 p = (u_char *)&pol->addr.sin6_addr;
1092 for (; mp < ep && *mp; mp++, k++, p++) {
1095 goto next; /* not match */
1096 if (m == 0xff) /* short cut for a typical case */
1106 /* matched. check if this is better than the current best. */
1107 if (bestpol == NULL ||
1108 matchlen > bestmatchlen) {
1110 bestmatchlen = matchlen;