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ipv6: annotate accesses to fn->fn_sernum
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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Linux INET6 implementation
4 * FIB front-end.
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 */
9
10 /* Changes:
11 *
12 * YOSHIFUJI Hideaki @USAGI
13 * reworked default router selection.
14 * - respect outgoing interface
15 * - select from (probably) reachable routers (i.e.
16 * routers in REACHABLE, STALE, DELAY or PROBE states).
17 * - always select the same router if it is (probably)
18 * reachable. otherwise, round-robin the list.
19 * Ville Nuorvala
20 * Fixed routing subtrees.
21 */
22
23 #define pr_fmt(fmt) "IPv6: " fmt
24
25 #include <linux/capability.h>
26 #include <linux/errno.h>
27 #include <linux/export.h>
28 #include <linux/types.h>
29 #include <linux/times.h>
30 #include <linux/socket.h>
31 #include <linux/sockios.h>
32 #include <linux/net.h>
33 #include <linux/route.h>
34 #include <linux/netdevice.h>
35 #include <linux/in6.h>
36 #include <linux/mroute6.h>
37 #include <linux/init.h>
38 #include <linux/if_arp.h>
39 #include <linux/proc_fs.h>
40 #include <linux/seq_file.h>
41 #include <linux/nsproxy.h>
42 #include <linux/slab.h>
43 #include <linux/jhash.h>
44 #include <linux/siphash.h>
45 #include <net/net_namespace.h>
46 #include <net/snmp.h>
47 #include <net/ipv6.h>
48 #include <net/ip6_fib.h>
49 #include <net/ip6_route.h>
50 #include <net/ndisc.h>
51 #include <net/addrconf.h>
52 #include <net/tcp.h>
53 #include <linux/rtnetlink.h>
54 #include <net/dst.h>
55 #include <net/dst_metadata.h>
56 #include <net/xfrm.h>
57 #include <net/netevent.h>
58 #include <net/netlink.h>
59 #include <net/rtnh.h>
60 #include <net/lwtunnel.h>
61 #include <net/ip_tunnels.h>
62 #include <net/l3mdev.h>
63 #include <net/ip.h>
64 #include <linux/uaccess.h>
65 #include <linux/btf_ids.h>
66
67 #ifdef CONFIG_SYSCTL
68 #include <linux/sysctl.h>
69 #endif
70
71 static int ip6_rt_type_to_error(u8 fib6_type);
72
73 #define CREATE_TRACE_POINTS
74 #include <trace/events/fib6.h>
75 EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup);
76 #undef CREATE_TRACE_POINTS
77
78 enum rt6_nud_state {
79 RT6_NUD_FAIL_HARD = -3,
80 RT6_NUD_FAIL_PROBE = -2,
81 RT6_NUD_FAIL_DO_RR = -1,
82 RT6_NUD_SUCCEED = 1
83 };
84
85 INDIRECT_CALLABLE_SCOPE
86 struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie);
87 static unsigned int ip6_default_advmss(const struct dst_entry *dst);
88 INDIRECT_CALLABLE_SCOPE
89 unsigned int ip6_mtu(const struct dst_entry *dst);
90 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
91 static void ip6_dst_destroy(struct dst_entry *);
92 static void ip6_dst_ifdown(struct dst_entry *,
93 struct net_device *dev, int how);
94 static int ip6_dst_gc(struct dst_ops *ops);
95
96 static int ip6_pkt_discard(struct sk_buff *skb);
97 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
98 static int ip6_pkt_prohibit(struct sk_buff *skb);
99 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb);
100 static void ip6_link_failure(struct sk_buff *skb);
101 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
102 struct sk_buff *skb, u32 mtu,
103 bool confirm_neigh);
104 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
105 struct sk_buff *skb);
106 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
107 int strict);
108 static size_t rt6_nlmsg_size(struct fib6_info *f6i);
109 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
110 struct fib6_info *rt, struct dst_entry *dst,
111 struct in6_addr *dest, struct in6_addr *src,
112 int iif, int type, u32 portid, u32 seq,
113 unsigned int flags);
114 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
115 const struct in6_addr *daddr,
116 const struct in6_addr *saddr);
117
118 #ifdef CONFIG_IPV6_ROUTE_INFO
119 static struct fib6_info *rt6_add_route_info(struct net *net,
120 const struct in6_addr *prefix, int prefixlen,
121 const struct in6_addr *gwaddr,
122 struct net_device *dev,
123 unsigned int pref);
124 static struct fib6_info *rt6_get_route_info(struct net *net,
125 const struct in6_addr *prefix, int prefixlen,
126 const struct in6_addr *gwaddr,
127 struct net_device *dev);
128 #endif
129
130 struct uncached_list {
131 spinlock_t lock;
132 struct list_head head;
133 };
134
135 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
136
137 void rt6_uncached_list_add(struct rt6_info *rt)
138 {
139 struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
140
141 rt->rt6i_uncached_list = ul;
142
143 spin_lock_bh(&ul->lock);
144 list_add_tail(&rt->rt6i_uncached, &ul->head);
145 spin_unlock_bh(&ul->lock);
146 }
147
148 void rt6_uncached_list_del(struct rt6_info *rt)
149 {
150 if (!list_empty(&rt->rt6i_uncached)) {
151 struct uncached_list *ul = rt->rt6i_uncached_list;
152 struct net *net = dev_net(rt->dst.dev);
153
154 spin_lock_bh(&ul->lock);
155 list_del(&rt->rt6i_uncached);
156 atomic_dec(&net->ipv6.rt6_stats->fib_rt_uncache);
157 spin_unlock_bh(&ul->lock);
158 }
159 }
160
161 static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev)
162 {
163 struct net_device *loopback_dev = net->loopback_dev;
164 int cpu;
165
166 if (dev == loopback_dev)
167 return;
168
169 for_each_possible_cpu(cpu) {
170 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
171 struct rt6_info *rt;
172
173 spin_lock_bh(&ul->lock);
174 list_for_each_entry(rt, &ul->head, rt6i_uncached) {
175 struct inet6_dev *rt_idev = rt->rt6i_idev;
176 struct net_device *rt_dev = rt->dst.dev;
177
178 if (rt_idev->dev == dev) {
179 rt->rt6i_idev = in6_dev_get(loopback_dev);
180 in6_dev_put(rt_idev);
181 }
182
183 if (rt_dev == dev) {
184 rt->dst.dev = blackhole_netdev;
185 dev_hold(rt->dst.dev);
186 dev_put(rt_dev);
187 }
188 }
189 spin_unlock_bh(&ul->lock);
190 }
191 }
192
193 static inline const void *choose_neigh_daddr(const struct in6_addr *p,
194 struct sk_buff *skb,
195 const void *daddr)
196 {
197 if (!ipv6_addr_any(p))
198 return (const void *) p;
199 else if (skb)
200 return &ipv6_hdr(skb)->daddr;
201 return daddr;
202 }
203
204 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
205 struct net_device *dev,
206 struct sk_buff *skb,
207 const void *daddr)
208 {
209 struct neighbour *n;
210
211 daddr = choose_neigh_daddr(gw, skb, daddr);
212 n = __ipv6_neigh_lookup(dev, daddr);
213 if (n)
214 return n;
215
216 n = neigh_create(&nd_tbl, daddr, dev);
217 return IS_ERR(n) ? NULL : n;
218 }
219
220 static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst,
221 struct sk_buff *skb,
222 const void *daddr)
223 {
224 const struct rt6_info *rt = container_of(dst, struct rt6_info, dst);
225
226 return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any),
227 dst->dev, skb, daddr);
228 }
229
230 static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr)
231 {
232 struct net_device *dev = dst->dev;
233 struct rt6_info *rt = (struct rt6_info *)dst;
234
235 daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr);
236 if (!daddr)
237 return;
238 if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
239 return;
240 if (ipv6_addr_is_multicast((const struct in6_addr *)daddr))
241 return;
242 __ipv6_confirm_neigh(dev, daddr);
243 }
244
245 static struct dst_ops ip6_dst_ops_template = {
246 .family = AF_INET6,
247 .gc = ip6_dst_gc,
248 .gc_thresh = 1024,
249 .check = ip6_dst_check,
250 .default_advmss = ip6_default_advmss,
251 .mtu = ip6_mtu,
252 .cow_metrics = dst_cow_metrics_generic,
253 .destroy = ip6_dst_destroy,
254 .ifdown = ip6_dst_ifdown,
255 .negative_advice = ip6_negative_advice,
256 .link_failure = ip6_link_failure,
257 .update_pmtu = ip6_rt_update_pmtu,
258 .redirect = rt6_do_redirect,
259 .local_out = __ip6_local_out,
260 .neigh_lookup = ip6_dst_neigh_lookup,
261 .confirm_neigh = ip6_confirm_neigh,
262 };
263
264 static struct dst_ops ip6_dst_blackhole_ops = {
265 .family = AF_INET6,
266 .default_advmss = ip6_default_advmss,
267 .neigh_lookup = ip6_dst_neigh_lookup,
268 .check = ip6_dst_check,
269 .destroy = ip6_dst_destroy,
270 .cow_metrics = dst_cow_metrics_generic,
271 .update_pmtu = dst_blackhole_update_pmtu,
272 .redirect = dst_blackhole_redirect,
273 .mtu = dst_blackhole_mtu,
274 };
275
276 static const u32 ip6_template_metrics[RTAX_MAX] = {
277 [RTAX_HOPLIMIT - 1] = 0,
278 };
279
280 static const struct fib6_info fib6_null_entry_template = {
281 .fib6_flags = (RTF_REJECT | RTF_NONEXTHOP),
282 .fib6_protocol = RTPROT_KERNEL,
283 .fib6_metric = ~(u32)0,
284 .fib6_ref = REFCOUNT_INIT(1),
285 .fib6_type = RTN_UNREACHABLE,
286 .fib6_metrics = (struct dst_metrics *)&dst_default_metrics,
287 };
288
289 static const struct rt6_info ip6_null_entry_template = {
290 .dst = {
291 .__refcnt = ATOMIC_INIT(1),
292 .__use = 1,
293 .obsolete = DST_OBSOLETE_FORCE_CHK,
294 .error = -ENETUNREACH,
295 .input = ip6_pkt_discard,
296 .output = ip6_pkt_discard_out,
297 },
298 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP),
299 };
300
301 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
302
303 static const struct rt6_info ip6_prohibit_entry_template = {
304 .dst = {
305 .__refcnt = ATOMIC_INIT(1),
306 .__use = 1,
307 .obsolete = DST_OBSOLETE_FORCE_CHK,
308 .error = -EACCES,
309 .input = ip6_pkt_prohibit,
310 .output = ip6_pkt_prohibit_out,
311 },
312 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP),
313 };
314
315 static const struct rt6_info ip6_blk_hole_entry_template = {
316 .dst = {
317 .__refcnt = ATOMIC_INIT(1),
318 .__use = 1,
319 .obsolete = DST_OBSOLETE_FORCE_CHK,
320 .error = -EINVAL,
321 .input = dst_discard,
322 .output = dst_discard_out,
323 },
324 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP),
325 };
326
327 #endif
328
329 static void rt6_info_init(struct rt6_info *rt)
330 {
331 struct dst_entry *dst = &rt->dst;
332
333 memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));
334 INIT_LIST_HEAD(&rt->rt6i_uncached);
335 }
336
337 /* allocate dst with ip6_dst_ops */
338 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
339 int flags)
340 {
341 struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
342 1, DST_OBSOLETE_FORCE_CHK, flags);
343
344 if (rt) {
345 rt6_info_init(rt);
346 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
347 }
348
349 return rt;
350 }
351 EXPORT_SYMBOL(ip6_dst_alloc);
352
353 static void ip6_dst_destroy(struct dst_entry *dst)
354 {
355 struct rt6_info *rt = (struct rt6_info *)dst;
356 struct fib6_info *from;
357 struct inet6_dev *idev;
358
359 ip_dst_metrics_put(dst);
360 rt6_uncached_list_del(rt);
361
362 idev = rt->rt6i_idev;
363 if (idev) {
364 rt->rt6i_idev = NULL;
365 in6_dev_put(idev);
366 }
367
368 from = xchg((__force struct fib6_info **)&rt->from, NULL);
369 fib6_info_release(from);
370 }
371
372 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
373 int how)
374 {
375 struct rt6_info *rt = (struct rt6_info *)dst;
376 struct inet6_dev *idev = rt->rt6i_idev;
377 struct net_device *loopback_dev =
378 dev_net(dev)->loopback_dev;
379
380 if (idev && idev->dev != loopback_dev) {
381 struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
382 if (loopback_idev) {
383 rt->rt6i_idev = loopback_idev;
384 in6_dev_put(idev);
385 }
386 }
387 }
388
389 static bool __rt6_check_expired(const struct rt6_info *rt)
390 {
391 if (rt->rt6i_flags & RTF_EXPIRES)
392 return time_after(jiffies, rt->dst.expires);
393 else
394 return false;
395 }
396
397 static bool rt6_check_expired(const struct rt6_info *rt)
398 {
399 struct fib6_info *from;
400
401 from = rcu_dereference(rt->from);
402
403 if (rt->rt6i_flags & RTF_EXPIRES) {
404 if (time_after(jiffies, rt->dst.expires))
405 return true;
406 } else if (from) {
407 return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
408 fib6_check_expired(from);
409 }
410 return false;
411 }
412
413 void fib6_select_path(const struct net *net, struct fib6_result *res,
414 struct flowi6 *fl6, int oif, bool have_oif_match,
415 const struct sk_buff *skb, int strict)
416 {
417 struct fib6_info *sibling, *next_sibling;
418 struct fib6_info *match = res->f6i;
419
420 if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
421 goto out;
422
423 if (match->nh && have_oif_match && res->nh)
424 return;
425
426 /* We might have already computed the hash for ICMPv6 errors. In such
427 * case it will always be non-zero. Otherwise now is the time to do it.
428 */
429 if (!fl6->mp_hash &&
430 (!match->nh || nexthop_is_multipath(match->nh)))
431 fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
432
433 if (unlikely(match->nh)) {
434 nexthop_path_fib6_result(res, fl6->mp_hash);
435 return;
436 }
437
438 if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
439 goto out;
440
441 list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
442 fib6_siblings) {
443 const struct fib6_nh *nh = sibling->fib6_nh;
444 int nh_upper_bound;
445
446 nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
447 if (fl6->mp_hash > nh_upper_bound)
448 continue;
449 if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
450 break;
451 match = sibling;
452 break;
453 }
454
455 out:
456 res->f6i = match;
457 res->nh = match->fib6_nh;
458 }
459
460 /*
461 * Route lookup. rcu_read_lock() should be held.
462 */
463
464 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
465 const struct in6_addr *saddr, int oif, int flags)
466 {
467 const struct net_device *dev;
468
469 if (nh->fib_nh_flags & RTNH_F_DEAD)
470 return false;
471
472 dev = nh->fib_nh_dev;
473 if (oif) {
474 if (dev->ifindex == oif)
475 return true;
476 } else {
477 if (ipv6_chk_addr(net, saddr, dev,
478 flags & RT6_LOOKUP_F_IFACE))
479 return true;
480 }
481
482 return false;
483 }
484
485 struct fib6_nh_dm_arg {
486 struct net *net;
487 const struct in6_addr *saddr;
488 int oif;
489 int flags;
490 struct fib6_nh *nh;
491 };
492
493 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
494 {
495 struct fib6_nh_dm_arg *arg = _arg;
496
497 arg->nh = nh;
498 return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
499 arg->flags);
500 }
501
502 /* returns fib6_nh from nexthop or NULL */
503 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
504 struct fib6_result *res,
505 const struct in6_addr *saddr,
506 int oif, int flags)
507 {
508 struct fib6_nh_dm_arg arg = {
509 .net = net,
510 .saddr = saddr,
511 .oif = oif,
512 .flags = flags,
513 };
514
515 if (nexthop_is_blackhole(nh))
516 return NULL;
517
518 if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
519 return arg.nh;
520
521 return NULL;
522 }
523
524 static void rt6_device_match(struct net *net, struct fib6_result *res,
525 const struct in6_addr *saddr, int oif, int flags)
526 {
527 struct fib6_info *f6i = res->f6i;
528 struct fib6_info *spf6i;
529 struct fib6_nh *nh;
530
531 if (!oif && ipv6_addr_any(saddr)) {
532 if (unlikely(f6i->nh)) {
533 nh = nexthop_fib6_nh(f6i->nh);
534 if (nexthop_is_blackhole(f6i->nh))
535 goto out_blackhole;
536 } else {
537 nh = f6i->fib6_nh;
538 }
539 if (!(nh->fib_nh_flags & RTNH_F_DEAD))
540 goto out;
541 }
542
543 for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
544 bool matched = false;
545
546 if (unlikely(spf6i->nh)) {
547 nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
548 oif, flags);
549 if (nh)
550 matched = true;
551 } else {
552 nh = spf6i->fib6_nh;
553 if (__rt6_device_match(net, nh, saddr, oif, flags))
554 matched = true;
555 }
556 if (matched) {
557 res->f6i = spf6i;
558 goto out;
559 }
560 }
561
562 if (oif && flags & RT6_LOOKUP_F_IFACE) {
563 res->f6i = net->ipv6.fib6_null_entry;
564 nh = res->f6i->fib6_nh;
565 goto out;
566 }
567
568 if (unlikely(f6i->nh)) {
569 nh = nexthop_fib6_nh(f6i->nh);
570 if (nexthop_is_blackhole(f6i->nh))
571 goto out_blackhole;
572 } else {
573 nh = f6i->fib6_nh;
574 }
575
576 if (nh->fib_nh_flags & RTNH_F_DEAD) {
577 res->f6i = net->ipv6.fib6_null_entry;
578 nh = res->f6i->fib6_nh;
579 }
580 out:
581 res->nh = nh;
582 res->fib6_type = res->f6i->fib6_type;
583 res->fib6_flags = res->f6i->fib6_flags;
584 return;
585
586 out_blackhole:
587 res->fib6_flags |= RTF_REJECT;
588 res->fib6_type = RTN_BLACKHOLE;
589 res->nh = nh;
590 }
591
592 #ifdef CONFIG_IPV6_ROUTER_PREF
593 struct __rt6_probe_work {
594 struct work_struct work;
595 struct in6_addr target;
596 struct net_device *dev;
597 };
598
599 static void rt6_probe_deferred(struct work_struct *w)
600 {
601 struct in6_addr mcaddr;
602 struct __rt6_probe_work *work =
603 container_of(w, struct __rt6_probe_work, work);
604
605 addrconf_addr_solict_mult(&work->target, &mcaddr);
606 ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
607 dev_put(work->dev);
608 kfree(work);
609 }
610
611 static void rt6_probe(struct fib6_nh *fib6_nh)
612 {
613 struct __rt6_probe_work *work = NULL;
614 const struct in6_addr *nh_gw;
615 unsigned long last_probe;
616 struct neighbour *neigh;
617 struct net_device *dev;
618 struct inet6_dev *idev;
619
620 /*
621 * Okay, this does not seem to be appropriate
622 * for now, however, we need to check if it
623 * is really so; aka Router Reachability Probing.
624 *
625 * Router Reachability Probe MUST be rate-limited
626 * to no more than one per minute.
627 */
628 if (!fib6_nh->fib_nh_gw_family)
629 return;
630
631 nh_gw = &fib6_nh->fib_nh_gw6;
632 dev = fib6_nh->fib_nh_dev;
633 rcu_read_lock_bh();
634 last_probe = READ_ONCE(fib6_nh->last_probe);
635 idev = __in6_dev_get(dev);
636 neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
637 if (neigh) {
638 if (neigh->nud_state & NUD_VALID)
639 goto out;
640
641 write_lock(&neigh->lock);
642 if (!(neigh->nud_state & NUD_VALID) &&
643 time_after(jiffies,
644 neigh->updated + idev->cnf.rtr_probe_interval)) {
645 work = kmalloc(sizeof(*work), GFP_ATOMIC);
646 if (work)
647 __neigh_set_probe_once(neigh);
648 }
649 write_unlock(&neigh->lock);
650 } else if (time_after(jiffies, last_probe +
651 idev->cnf.rtr_probe_interval)) {
652 work = kmalloc(sizeof(*work), GFP_ATOMIC);
653 }
654
655 if (!work || cmpxchg(&fib6_nh->last_probe,
656 last_probe, jiffies) != last_probe) {
657 kfree(work);
658 } else {
659 INIT_WORK(&work->work, rt6_probe_deferred);
660 work->target = *nh_gw;
661 dev_hold(dev);
662 work->dev = dev;
663 schedule_work(&work->work);
664 }
665
666 out:
667 rcu_read_unlock_bh();
668 }
669 #else
670 static inline void rt6_probe(struct fib6_nh *fib6_nh)
671 {
672 }
673 #endif
674
675 /*
676 * Default Router Selection (RFC 2461 6.3.6)
677 */
678 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
679 {
680 enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
681 struct neighbour *neigh;
682
683 rcu_read_lock_bh();
684 neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
685 &fib6_nh->fib_nh_gw6);
686 if (neigh) {
687 read_lock(&neigh->lock);
688 if (neigh->nud_state & NUD_VALID)
689 ret = RT6_NUD_SUCCEED;
690 #ifdef CONFIG_IPV6_ROUTER_PREF
691 else if (!(neigh->nud_state & NUD_FAILED))
692 ret = RT6_NUD_SUCCEED;
693 else
694 ret = RT6_NUD_FAIL_PROBE;
695 #endif
696 read_unlock(&neigh->lock);
697 } else {
698 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
699 RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
700 }
701 rcu_read_unlock_bh();
702
703 return ret;
704 }
705
706 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
707 int strict)
708 {
709 int m = 0;
710
711 if (!oif || nh->fib_nh_dev->ifindex == oif)
712 m = 2;
713
714 if (!m && (strict & RT6_LOOKUP_F_IFACE))
715 return RT6_NUD_FAIL_HARD;
716 #ifdef CONFIG_IPV6_ROUTER_PREF
717 m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
718 #endif
719 if ((strict & RT6_LOOKUP_F_REACHABLE) &&
720 !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
721 int n = rt6_check_neigh(nh);
722 if (n < 0)
723 return n;
724 }
725 return m;
726 }
727
728 static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
729 int oif, int strict, int *mpri, bool *do_rr)
730 {
731 bool match_do_rr = false;
732 bool rc = false;
733 int m;
734
735 if (nh->fib_nh_flags & RTNH_F_DEAD)
736 goto out;
737
738 if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
739 nh->fib_nh_flags & RTNH_F_LINKDOWN &&
740 !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
741 goto out;
742
743 m = rt6_score_route(nh, fib6_flags, oif, strict);
744 if (m == RT6_NUD_FAIL_DO_RR) {
745 match_do_rr = true;
746 m = 0; /* lowest valid score */
747 } else if (m == RT6_NUD_FAIL_HARD) {
748 goto out;
749 }
750
751 if (strict & RT6_LOOKUP_F_REACHABLE)
752 rt6_probe(nh);
753
754 /* note that m can be RT6_NUD_FAIL_PROBE at this point */
755 if (m > *mpri) {
756 *do_rr = match_do_rr;
757 *mpri = m;
758 rc = true;
759 }
760 out:
761 return rc;
762 }
763
764 struct fib6_nh_frl_arg {
765 u32 flags;
766 int oif;
767 int strict;
768 int *mpri;
769 bool *do_rr;
770 struct fib6_nh *nh;
771 };
772
773 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
774 {
775 struct fib6_nh_frl_arg *arg = _arg;
776
777 arg->nh = nh;
778 return find_match(nh, arg->flags, arg->oif, arg->strict,
779 arg->mpri, arg->do_rr);
780 }
781
782 static void __find_rr_leaf(struct fib6_info *f6i_start,
783 struct fib6_info *nomatch, u32 metric,
784 struct fib6_result *res, struct fib6_info **cont,
785 int oif, int strict, bool *do_rr, int *mpri)
786 {
787 struct fib6_info *f6i;
788
789 for (f6i = f6i_start;
790 f6i && f6i != nomatch;
791 f6i = rcu_dereference(f6i->fib6_next)) {
792 bool matched = false;
793 struct fib6_nh *nh;
794
795 if (cont && f6i->fib6_metric != metric) {
796 *cont = f6i;
797 return;
798 }
799
800 if (fib6_check_expired(f6i))
801 continue;
802
803 if (unlikely(f6i->nh)) {
804 struct fib6_nh_frl_arg arg = {
805 .flags = f6i->fib6_flags,
806 .oif = oif,
807 .strict = strict,
808 .mpri = mpri,
809 .do_rr = do_rr
810 };
811
812 if (nexthop_is_blackhole(f6i->nh)) {
813 res->fib6_flags = RTF_REJECT;
814 res->fib6_type = RTN_BLACKHOLE;
815 res->f6i = f6i;
816 res->nh = nexthop_fib6_nh(f6i->nh);
817 return;
818 }
819 if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
820 &arg)) {
821 matched = true;
822 nh = arg.nh;
823 }
824 } else {
825 nh = f6i->fib6_nh;
826 if (find_match(nh, f6i->fib6_flags, oif, strict,
827 mpri, do_rr))
828 matched = true;
829 }
830 if (matched) {
831 res->f6i = f6i;
832 res->nh = nh;
833 res->fib6_flags = f6i->fib6_flags;
834 res->fib6_type = f6i->fib6_type;
835 }
836 }
837 }
838
839 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
840 struct fib6_info *rr_head, int oif, int strict,
841 bool *do_rr, struct fib6_result *res)
842 {
843 u32 metric = rr_head->fib6_metric;
844 struct fib6_info *cont = NULL;
845 int mpri = -1;
846
847 __find_rr_leaf(rr_head, NULL, metric, res, &cont,
848 oif, strict, do_rr, &mpri);
849
850 __find_rr_leaf(leaf, rr_head, metric, res, &cont,
851 oif, strict, do_rr, &mpri);
852
853 if (res->f6i || !cont)
854 return;
855
856 __find_rr_leaf(cont, NULL, metric, res, NULL,
857 oif, strict, do_rr, &mpri);
858 }
859
860 static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
861 struct fib6_result *res, int strict)
862 {
863 struct fib6_info *leaf = rcu_dereference(fn->leaf);
864 struct fib6_info *rt0;
865 bool do_rr = false;
866 int key_plen;
867
868 /* make sure this function or its helpers sets f6i */
869 res->f6i = NULL;
870
871 if (!leaf || leaf == net->ipv6.fib6_null_entry)
872 goto out;
873
874 rt0 = rcu_dereference(fn->rr_ptr);
875 if (!rt0)
876 rt0 = leaf;
877
878 /* Double check to make sure fn is not an intermediate node
879 * and fn->leaf does not points to its child's leaf
880 * (This might happen if all routes under fn are deleted from
881 * the tree and fib6_repair_tree() is called on the node.)
882 */
883 key_plen = rt0->fib6_dst.plen;
884 #ifdef CONFIG_IPV6_SUBTREES
885 if (rt0->fib6_src.plen)
886 key_plen = rt0->fib6_src.plen;
887 #endif
888 if (fn->fn_bit != key_plen)
889 goto out;
890
891 find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
892 if (do_rr) {
893 struct fib6_info *next = rcu_dereference(rt0->fib6_next);
894
895 /* no entries matched; do round-robin */
896 if (!next || next->fib6_metric != rt0->fib6_metric)
897 next = leaf;
898
899 if (next != rt0) {
900 spin_lock_bh(&leaf->fib6_table->tb6_lock);
901 /* make sure next is not being deleted from the tree */
902 if (next->fib6_node)
903 rcu_assign_pointer(fn->rr_ptr, next);
904 spin_unlock_bh(&leaf->fib6_table->tb6_lock);
905 }
906 }
907
908 out:
909 if (!res->f6i) {
910 res->f6i = net->ipv6.fib6_null_entry;
911 res->nh = res->f6i->fib6_nh;
912 res->fib6_flags = res->f6i->fib6_flags;
913 res->fib6_type = res->f6i->fib6_type;
914 }
915 }
916
917 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
918 {
919 return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
920 res->nh->fib_nh_gw_family;
921 }
922
923 #ifdef CONFIG_IPV6_ROUTE_INFO
924 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
925 const struct in6_addr *gwaddr)
926 {
927 struct net *net = dev_net(dev);
928 struct route_info *rinfo = (struct route_info *) opt;
929 struct in6_addr prefix_buf, *prefix;
930 unsigned int pref;
931 unsigned long lifetime;
932 struct fib6_info *rt;
933
934 if (len < sizeof(struct route_info)) {
935 return -EINVAL;
936 }
937
938 /* Sanity check for prefix_len and length */
939 if (rinfo->length > 3) {
940 return -EINVAL;
941 } else if (rinfo->prefix_len > 128) {
942 return -EINVAL;
943 } else if (rinfo->prefix_len > 64) {
944 if (rinfo->length < 2) {
945 return -EINVAL;
946 }
947 } else if (rinfo->prefix_len > 0) {
948 if (rinfo->length < 1) {
949 return -EINVAL;
950 }
951 }
952
953 pref = rinfo->route_pref;
954 if (pref == ICMPV6_ROUTER_PREF_INVALID)
955 return -EINVAL;
956
957 lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
958
959 if (rinfo->length == 3)
960 prefix = (struct in6_addr *)rinfo->prefix;
961 else {
962 /* this function is safe */
963 ipv6_addr_prefix(&prefix_buf,
964 (struct in6_addr *)rinfo->prefix,
965 rinfo->prefix_len);
966 prefix = &prefix_buf;
967 }
968
969 if (rinfo->prefix_len == 0)
970 rt = rt6_get_dflt_router(net, gwaddr, dev);
971 else
972 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
973 gwaddr, dev);
974
975 if (rt && !lifetime) {
976 ip6_del_rt(net, rt, false);
977 rt = NULL;
978 }
979
980 if (!rt && lifetime)
981 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
982 dev, pref);
983 else if (rt)
984 rt->fib6_flags = RTF_ROUTEINFO |
985 (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
986
987 if (rt) {
988 if (!addrconf_finite_timeout(lifetime))
989 fib6_clean_expires(rt);
990 else
991 fib6_set_expires(rt, jiffies + HZ * lifetime);
992
993 fib6_info_release(rt);
994 }
995 return 0;
996 }
997 #endif
998
999 /*
1000 * Misc support functions
1001 */
1002
1003 /* called with rcu_lock held */
1004 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
1005 {
1006 struct net_device *dev = res->nh->fib_nh_dev;
1007
1008 if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
1009 /* for copies of local routes, dst->dev needs to be the
1010 * device if it is a master device, the master device if
1011 * device is enslaved, and the loopback as the default
1012 */
1013 if (netif_is_l3_slave(dev) &&
1014 !rt6_need_strict(&res->f6i->fib6_dst.addr))
1015 dev = l3mdev_master_dev_rcu(dev);
1016 else if (!netif_is_l3_master(dev))
1017 dev = dev_net(dev)->loopback_dev;
1018 /* last case is netif_is_l3_master(dev) is true in which
1019 * case we want dev returned to be dev
1020 */
1021 }
1022
1023 return dev;
1024 }
1025
1026 static const int fib6_prop[RTN_MAX + 1] = {
1027 [RTN_UNSPEC] = 0,
1028 [RTN_UNICAST] = 0,
1029 [RTN_LOCAL] = 0,
1030 [RTN_BROADCAST] = 0,
1031 [RTN_ANYCAST] = 0,
1032 [RTN_MULTICAST] = 0,
1033 [RTN_BLACKHOLE] = -EINVAL,
1034 [RTN_UNREACHABLE] = -EHOSTUNREACH,
1035 [RTN_PROHIBIT] = -EACCES,
1036 [RTN_THROW] = -EAGAIN,
1037 [RTN_NAT] = -EINVAL,
1038 [RTN_XRESOLVE] = -EINVAL,
1039 };
1040
1041 static int ip6_rt_type_to_error(u8 fib6_type)
1042 {
1043 return fib6_prop[fib6_type];
1044 }
1045
1046 static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
1047 {
1048 unsigned short flags = 0;
1049
1050 if (rt->dst_nocount)
1051 flags |= DST_NOCOUNT;
1052 if (rt->dst_nopolicy)
1053 flags |= DST_NOPOLICY;
1054
1055 return flags;
1056 }
1057
1058 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
1059 {
1060 rt->dst.error = ip6_rt_type_to_error(fib6_type);
1061
1062 switch (fib6_type) {
1063 case RTN_BLACKHOLE:
1064 rt->dst.output = dst_discard_out;
1065 rt->dst.input = dst_discard;
1066 break;
1067 case RTN_PROHIBIT:
1068 rt->dst.output = ip6_pkt_prohibit_out;
1069 rt->dst.input = ip6_pkt_prohibit;
1070 break;
1071 case RTN_THROW:
1072 case RTN_UNREACHABLE:
1073 default:
1074 rt->dst.output = ip6_pkt_discard_out;
1075 rt->dst.input = ip6_pkt_discard;
1076 break;
1077 }
1078 }
1079
1080 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
1081 {
1082 struct fib6_info *f6i = res->f6i;
1083
1084 if (res->fib6_flags & RTF_REJECT) {
1085 ip6_rt_init_dst_reject(rt, res->fib6_type);
1086 return;
1087 }
1088
1089 rt->dst.error = 0;
1090 rt->dst.output = ip6_output;
1091
1092 if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
1093 rt->dst.input = ip6_input;
1094 } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
1095 rt->dst.input = ip6_mc_input;
1096 } else {
1097 rt->dst.input = ip6_forward;
1098 }
1099
1100 if (res->nh->fib_nh_lws) {
1101 rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
1102 lwtunnel_set_redirect(&rt->dst);
1103 }
1104
1105 rt->dst.lastuse = jiffies;
1106 }
1107
1108 /* Caller must already hold reference to @from */
1109 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
1110 {
1111 rt->rt6i_flags &= ~RTF_EXPIRES;
1112 rcu_assign_pointer(rt->from, from);
1113 ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
1114 }
1115
1116 /* Caller must already hold reference to f6i in result */
1117 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
1118 {
1119 const struct fib6_nh *nh = res->nh;
1120 const struct net_device *dev = nh->fib_nh_dev;
1121 struct fib6_info *f6i = res->f6i;
1122
1123 ip6_rt_init_dst(rt, res);
1124
1125 rt->rt6i_dst = f6i->fib6_dst;
1126 rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
1127 rt->rt6i_flags = res->fib6_flags;
1128 if (nh->fib_nh_gw_family) {
1129 rt->rt6i_gateway = nh->fib_nh_gw6;
1130 rt->rt6i_flags |= RTF_GATEWAY;
1131 }
1132 rt6_set_from(rt, f6i);
1133 #ifdef CONFIG_IPV6_SUBTREES
1134 rt->rt6i_src = f6i->fib6_src;
1135 #endif
1136 }
1137
1138 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
1139 struct in6_addr *saddr)
1140 {
1141 struct fib6_node *pn, *sn;
1142 while (1) {
1143 if (fn->fn_flags & RTN_TL_ROOT)
1144 return NULL;
1145 pn = rcu_dereference(fn->parent);
1146 sn = FIB6_SUBTREE(pn);
1147 if (sn && sn != fn)
1148 fn = fib6_node_lookup(sn, NULL, saddr);
1149 else
1150 fn = pn;
1151 if (fn->fn_flags & RTN_RTINFO)
1152 return fn;
1153 }
1154 }
1155
1156 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
1157 {
1158 struct rt6_info *rt = *prt;
1159
1160 if (dst_hold_safe(&rt->dst))
1161 return true;
1162 if (net) {
1163 rt = net->ipv6.ip6_null_entry;
1164 dst_hold(&rt->dst);
1165 } else {
1166 rt = NULL;
1167 }
1168 *prt = rt;
1169 return false;
1170 }
1171
1172 /* called with rcu_lock held */
1173 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
1174 {
1175 struct net_device *dev = res->nh->fib_nh_dev;
1176 struct fib6_info *f6i = res->f6i;
1177 unsigned short flags;
1178 struct rt6_info *nrt;
1179
1180 if (!fib6_info_hold_safe(f6i))
1181 goto fallback;
1182
1183 flags = fib6_info_dst_flags(f6i);
1184 nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
1185 if (!nrt) {
1186 fib6_info_release(f6i);
1187 goto fallback;
1188 }
1189
1190 ip6_rt_copy_init(nrt, res);
1191 return nrt;
1192
1193 fallback:
1194 nrt = dev_net(dev)->ipv6.ip6_null_entry;
1195 dst_hold(&nrt->dst);
1196 return nrt;
1197 }
1198
1199 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
1200 struct fib6_table *table,
1201 struct flowi6 *fl6,
1202 const struct sk_buff *skb,
1203 int flags)
1204 {
1205 struct fib6_result res = {};
1206 struct fib6_node *fn;
1207 struct rt6_info *rt;
1208
1209 if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
1210 flags &= ~RT6_LOOKUP_F_IFACE;
1211
1212 rcu_read_lock();
1213 fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1214 restart:
1215 res.f6i = rcu_dereference(fn->leaf);
1216 if (!res.f6i)
1217 res.f6i = net->ipv6.fib6_null_entry;
1218 else
1219 rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
1220 flags);
1221
1222 if (res.f6i == net->ipv6.fib6_null_entry) {
1223 fn = fib6_backtrack(fn, &fl6->saddr);
1224 if (fn)
1225 goto restart;
1226
1227 rt = net->ipv6.ip6_null_entry;
1228 dst_hold(&rt->dst);
1229 goto out;
1230 } else if (res.fib6_flags & RTF_REJECT) {
1231 goto do_create;
1232 }
1233
1234 fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
1235 fl6->flowi6_oif != 0, skb, flags);
1236
1237 /* Search through exception table */
1238 rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
1239 if (rt) {
1240 if (ip6_hold_safe(net, &rt))
1241 dst_use_noref(&rt->dst, jiffies);
1242 } else {
1243 do_create:
1244 rt = ip6_create_rt_rcu(&res);
1245 }
1246
1247 out:
1248 trace_fib6_table_lookup(net, &res, table, fl6);
1249
1250 rcu_read_unlock();
1251
1252 return rt;
1253 }
1254
1255 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
1256 const struct sk_buff *skb, int flags)
1257 {
1258 return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
1259 }
1260 EXPORT_SYMBOL_GPL(ip6_route_lookup);
1261
1262 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
1263 const struct in6_addr *saddr, int oif,
1264 const struct sk_buff *skb, int strict)
1265 {
1266 struct flowi6 fl6 = {
1267 .flowi6_oif = oif,
1268 .daddr = *daddr,
1269 };
1270 struct dst_entry *dst;
1271 int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
1272
1273 if (saddr) {
1274 memcpy(&fl6.saddr, saddr, sizeof(*saddr));
1275 flags |= RT6_LOOKUP_F_HAS_SADDR;
1276 }
1277
1278 dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
1279 if (dst->error == 0)
1280 return (struct rt6_info *) dst;
1281
1282 dst_release(dst);
1283
1284 return NULL;
1285 }
1286 EXPORT_SYMBOL(rt6_lookup);
1287
1288 /* ip6_ins_rt is called with FREE table->tb6_lock.
1289 * It takes new route entry, the addition fails by any reason the
1290 * route is released.
1291 * Caller must hold dst before calling it.
1292 */
1293
1294 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
1295 struct netlink_ext_ack *extack)
1296 {
1297 int err;
1298 struct fib6_table *table;
1299
1300 table = rt->fib6_table;
1301 spin_lock_bh(&table->tb6_lock);
1302 err = fib6_add(&table->tb6_root, rt, info, extack);
1303 spin_unlock_bh(&table->tb6_lock);
1304
1305 return err;
1306 }
1307
1308 int ip6_ins_rt(struct net *net, struct fib6_info *rt)
1309 {
1310 struct nl_info info = { .nl_net = net, };
1311
1312 return __ip6_ins_rt(rt, &info, NULL);
1313 }
1314
1315 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
1316 const struct in6_addr *daddr,
1317 const struct in6_addr *saddr)
1318 {
1319 struct fib6_info *f6i = res->f6i;
1320 struct net_device *dev;
1321 struct rt6_info *rt;
1322
1323 /*
1324 * Clone the route.
1325 */
1326
1327 if (!fib6_info_hold_safe(f6i))
1328 return NULL;
1329
1330 dev = ip6_rt_get_dev_rcu(res);
1331 rt = ip6_dst_alloc(dev_net(dev), dev, 0);
1332 if (!rt) {
1333 fib6_info_release(f6i);
1334 return NULL;
1335 }
1336
1337 ip6_rt_copy_init(rt, res);
1338 rt->rt6i_flags |= RTF_CACHE;
1339 rt->rt6i_dst.addr = *daddr;
1340 rt->rt6i_dst.plen = 128;
1341
1342 if (!rt6_is_gw_or_nonexthop(res)) {
1343 if (f6i->fib6_dst.plen != 128 &&
1344 ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
1345 rt->rt6i_flags |= RTF_ANYCAST;
1346 #ifdef CONFIG_IPV6_SUBTREES
1347 if (rt->rt6i_src.plen && saddr) {
1348 rt->rt6i_src.addr = *saddr;
1349 rt->rt6i_src.plen = 128;
1350 }
1351 #endif
1352 }
1353
1354 return rt;
1355 }
1356
1357 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
1358 {
1359 struct fib6_info *f6i = res->f6i;
1360 unsigned short flags = fib6_info_dst_flags(f6i);
1361 struct net_device *dev;
1362 struct rt6_info *pcpu_rt;
1363
1364 if (!fib6_info_hold_safe(f6i))
1365 return NULL;
1366
1367 rcu_read_lock();
1368 dev = ip6_rt_get_dev_rcu(res);
1369 pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT);
1370 rcu_read_unlock();
1371 if (!pcpu_rt) {
1372 fib6_info_release(f6i);
1373 return NULL;
1374 }
1375 ip6_rt_copy_init(pcpu_rt, res);
1376 pcpu_rt->rt6i_flags |= RTF_PCPU;
1377
1378 if (f6i->nh)
1379 pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev));
1380
1381 return pcpu_rt;
1382 }
1383
1384 static bool rt6_is_valid(const struct rt6_info *rt6)
1385 {
1386 return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev));
1387 }
1388
1389 /* It should be called with rcu_read_lock() acquired */
1390 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
1391 {
1392 struct rt6_info *pcpu_rt;
1393
1394 pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
1395
1396 if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) {
1397 struct rt6_info *prev, **p;
1398
1399 p = this_cpu_ptr(res->nh->rt6i_pcpu);
1400 prev = xchg(p, NULL);
1401 if (prev) {
1402 dst_dev_put(&prev->dst);
1403 dst_release(&prev->dst);
1404 }
1405
1406 pcpu_rt = NULL;
1407 }
1408
1409 return pcpu_rt;
1410 }
1411
1412 static struct rt6_info *rt6_make_pcpu_route(struct net *net,
1413 const struct fib6_result *res)
1414 {
1415 struct rt6_info *pcpu_rt, *prev, **p;
1416
1417 pcpu_rt = ip6_rt_pcpu_alloc(res);
1418 if (!pcpu_rt)
1419 return NULL;
1420
1421 p = this_cpu_ptr(res->nh->rt6i_pcpu);
1422 prev = cmpxchg(p, NULL, pcpu_rt);
1423 BUG_ON(prev);
1424
1425 if (res->f6i->fib6_destroying) {
1426 struct fib6_info *from;
1427
1428 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
1429 fib6_info_release(from);
1430 }
1431
1432 return pcpu_rt;
1433 }
1434
1435 /* exception hash table implementation
1436 */
1437 static DEFINE_SPINLOCK(rt6_exception_lock);
1438
1439 /* Remove rt6_ex from hash table and free the memory
1440 * Caller must hold rt6_exception_lock
1441 */
1442 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
1443 struct rt6_exception *rt6_ex)
1444 {
1445 struct fib6_info *from;
1446 struct net *net;
1447
1448 if (!bucket || !rt6_ex)
1449 return;
1450
1451 net = dev_net(rt6_ex->rt6i->dst.dev);
1452 net->ipv6.rt6_stats->fib_rt_cache--;
1453
1454 /* purge completely the exception to allow releasing the held resources:
1455 * some [sk] cache may keep the dst around for unlimited time
1456 */
1457 from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL);
1458 fib6_info_release(from);
1459 dst_dev_put(&rt6_ex->rt6i->dst);
1460
1461 hlist_del_rcu(&rt6_ex->hlist);
1462 dst_release(&rt6_ex->rt6i->dst);
1463 kfree_rcu(rt6_ex, rcu);
1464 WARN_ON_ONCE(!bucket->depth);
1465 bucket->depth--;
1466 }
1467
1468 /* Remove oldest rt6_ex in bucket and free the memory
1469 * Caller must hold rt6_exception_lock
1470 */
1471 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
1472 {
1473 struct rt6_exception *rt6_ex, *oldest = NULL;
1474
1475 if (!bucket)
1476 return;
1477
1478 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1479 if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
1480 oldest = rt6_ex;
1481 }
1482 rt6_remove_exception(bucket, oldest);
1483 }
1484
1485 static u32 rt6_exception_hash(const struct in6_addr *dst,
1486 const struct in6_addr *src)
1487 {
1488 static siphash_key_t rt6_exception_key __read_mostly;
1489 struct {
1490 struct in6_addr dst;
1491 struct in6_addr src;
1492 } __aligned(SIPHASH_ALIGNMENT) combined = {
1493 .dst = *dst,
1494 };
1495 u64 val;
1496
1497 net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key));
1498
1499 #ifdef CONFIG_IPV6_SUBTREES
1500 if (src)
1501 combined.src = *src;
1502 #endif
1503 val = siphash(&combined, sizeof(combined), &rt6_exception_key);
1504
1505 return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
1506 }
1507
1508 /* Helper function to find the cached rt in the hash table
1509 * and update bucket pointer to point to the bucket for this
1510 * (daddr, saddr) pair
1511 * Caller must hold rt6_exception_lock
1512 */
1513 static struct rt6_exception *
1514 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
1515 const struct in6_addr *daddr,
1516 const struct in6_addr *saddr)
1517 {
1518 struct rt6_exception *rt6_ex;
1519 u32 hval;
1520
1521 if (!(*bucket) || !daddr)
1522 return NULL;
1523
1524 hval = rt6_exception_hash(daddr, saddr);
1525 *bucket += hval;
1526
1527 hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
1528 struct rt6_info *rt6 = rt6_ex->rt6i;
1529 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1530
1531 #ifdef CONFIG_IPV6_SUBTREES
1532 if (matched && saddr)
1533 matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1534 #endif
1535 if (matched)
1536 return rt6_ex;
1537 }
1538 return NULL;
1539 }
1540
1541 /* Helper function to find the cached rt in the hash table
1542 * and update bucket pointer to point to the bucket for this
1543 * (daddr, saddr) pair
1544 * Caller must hold rcu_read_lock()
1545 */
1546 static struct rt6_exception *
1547 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
1548 const struct in6_addr *daddr,
1549 const struct in6_addr *saddr)
1550 {
1551 struct rt6_exception *rt6_ex;
1552 u32 hval;
1553
1554 WARN_ON_ONCE(!rcu_read_lock_held());
1555
1556 if (!(*bucket) || !daddr)
1557 return NULL;
1558
1559 hval = rt6_exception_hash(daddr, saddr);
1560 *bucket += hval;
1561
1562 hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
1563 struct rt6_info *rt6 = rt6_ex->rt6i;
1564 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1565
1566 #ifdef CONFIG_IPV6_SUBTREES
1567 if (matched && saddr)
1568 matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1569 #endif
1570 if (matched)
1571 return rt6_ex;
1572 }
1573 return NULL;
1574 }
1575
1576 static unsigned int fib6_mtu(const struct fib6_result *res)
1577 {
1578 const struct fib6_nh *nh = res->nh;
1579 unsigned int mtu;
1580
1581 if (res->f6i->fib6_pmtu) {
1582 mtu = res->f6i->fib6_pmtu;
1583 } else {
1584 struct net_device *dev = nh->fib_nh_dev;
1585 struct inet6_dev *idev;
1586
1587 rcu_read_lock();
1588 idev = __in6_dev_get(dev);
1589 mtu = idev->cnf.mtu6;
1590 rcu_read_unlock();
1591 }
1592
1593 mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
1594
1595 return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
1596 }
1597
1598 #define FIB6_EXCEPTION_BUCKET_FLUSHED 0x1UL
1599
1600 /* used when the flushed bit is not relevant, only access to the bucket
1601 * (ie., all bucket users except rt6_insert_exception);
1602 *
1603 * called under rcu lock; sometimes called with rt6_exception_lock held
1604 */
1605 static
1606 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
1607 spinlock_t *lock)
1608 {
1609 struct rt6_exception_bucket *bucket;
1610
1611 if (lock)
1612 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1613 lockdep_is_held(lock));
1614 else
1615 bucket = rcu_dereference(nh->rt6i_exception_bucket);
1616
1617 /* remove bucket flushed bit if set */
1618 if (bucket) {
1619 unsigned long p = (unsigned long)bucket;
1620
1621 p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
1622 bucket = (struct rt6_exception_bucket *)p;
1623 }
1624
1625 return bucket;
1626 }
1627
1628 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
1629 {
1630 unsigned long p = (unsigned long)bucket;
1631
1632 return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
1633 }
1634
1635 /* called with rt6_exception_lock held */
1636 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
1637 spinlock_t *lock)
1638 {
1639 struct rt6_exception_bucket *bucket;
1640 unsigned long p;
1641
1642 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1643 lockdep_is_held(lock));
1644
1645 p = (unsigned long)bucket;
1646 p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
1647 bucket = (struct rt6_exception_bucket *)p;
1648 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1649 }
1650
1651 static int rt6_insert_exception(struct rt6_info *nrt,
1652 const struct fib6_result *res)
1653 {
1654 struct net *net = dev_net(nrt->dst.dev);
1655 struct rt6_exception_bucket *bucket;
1656 struct fib6_info *f6i = res->f6i;
1657 struct in6_addr *src_key = NULL;
1658 struct rt6_exception *rt6_ex;
1659 struct fib6_nh *nh = res->nh;
1660 int max_depth;
1661 int err = 0;
1662
1663 spin_lock_bh(&rt6_exception_lock);
1664
1665 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1666 lockdep_is_held(&rt6_exception_lock));
1667 if (!bucket) {
1668 bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
1669 GFP_ATOMIC);
1670 if (!bucket) {
1671 err = -ENOMEM;
1672 goto out;
1673 }
1674 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1675 } else if (fib6_nh_excptn_bucket_flushed(bucket)) {
1676 err = -EINVAL;
1677 goto out;
1678 }
1679
1680 #ifdef CONFIG_IPV6_SUBTREES
1681 /* fib6_src.plen != 0 indicates f6i is in subtree
1682 * and exception table is indexed by a hash of
1683 * both fib6_dst and fib6_src.
1684 * Otherwise, the exception table is indexed by
1685 * a hash of only fib6_dst.
1686 */
1687 if (f6i->fib6_src.plen)
1688 src_key = &nrt->rt6i_src.addr;
1689 #endif
1690 /* rt6_mtu_change() might lower mtu on f6i.
1691 * Only insert this exception route if its mtu
1692 * is less than f6i's mtu value.
1693 */
1694 if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
1695 err = -EINVAL;
1696 goto out;
1697 }
1698
1699 rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
1700 src_key);
1701 if (rt6_ex)
1702 rt6_remove_exception(bucket, rt6_ex);
1703
1704 rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
1705 if (!rt6_ex) {
1706 err = -ENOMEM;
1707 goto out;
1708 }
1709 rt6_ex->rt6i = nrt;
1710 rt6_ex->stamp = jiffies;
1711 hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
1712 bucket->depth++;
1713 net->ipv6.rt6_stats->fib_rt_cache++;
1714
1715 /* Randomize max depth to avoid some side channels attacks. */
1716 max_depth = FIB6_MAX_DEPTH + prandom_u32_max(FIB6_MAX_DEPTH);
1717 while (bucket->depth > max_depth)
1718 rt6_exception_remove_oldest(bucket);
1719
1720 out:
1721 spin_unlock_bh(&rt6_exception_lock);
1722
1723 /* Update fn->fn_sernum to invalidate all cached dst */
1724 if (!err) {
1725 spin_lock_bh(&f6i->fib6_table->tb6_lock);
1726 fib6_update_sernum(net, f6i);
1727 spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1728 fib6_force_start_gc(net);
1729 }
1730
1731 return err;
1732 }
1733
1734 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
1735 {
1736 struct rt6_exception_bucket *bucket;
1737 struct rt6_exception *rt6_ex;
1738 struct hlist_node *tmp;
1739 int i;
1740
1741 spin_lock_bh(&rt6_exception_lock);
1742
1743 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1744 if (!bucket)
1745 goto out;
1746
1747 /* Prevent rt6_insert_exception() to recreate the bucket list */
1748 if (!from)
1749 fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
1750
1751 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1752 hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
1753 if (!from ||
1754 rcu_access_pointer(rt6_ex->rt6i->from) == from)
1755 rt6_remove_exception(bucket, rt6_ex);
1756 }
1757 WARN_ON_ONCE(!from && bucket->depth);
1758 bucket++;
1759 }
1760 out:
1761 spin_unlock_bh(&rt6_exception_lock);
1762 }
1763
1764 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
1765 {
1766 struct fib6_info *f6i = arg;
1767
1768 fib6_nh_flush_exceptions(nh, f6i);
1769
1770 return 0;
1771 }
1772
1773 void rt6_flush_exceptions(struct fib6_info *f6i)
1774 {
1775 if (f6i->nh)
1776 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
1777 f6i);
1778 else
1779 fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
1780 }
1781
1782 /* Find cached rt in the hash table inside passed in rt
1783 * Caller has to hold rcu_read_lock()
1784 */
1785 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
1786 const struct in6_addr *daddr,
1787 const struct in6_addr *saddr)
1788 {
1789 const struct in6_addr *src_key = NULL;
1790 struct rt6_exception_bucket *bucket;
1791 struct rt6_exception *rt6_ex;
1792 struct rt6_info *ret = NULL;
1793
1794 #ifdef CONFIG_IPV6_SUBTREES
1795 /* fib6i_src.plen != 0 indicates f6i is in subtree
1796 * and exception table is indexed by a hash of
1797 * both fib6_dst and fib6_src.
1798 * However, the src addr used to create the hash
1799 * might not be exactly the passed in saddr which
1800 * is a /128 addr from the flow.
1801 * So we need to use f6i->fib6_src to redo lookup
1802 * if the passed in saddr does not find anything.
1803 * (See the logic in ip6_rt_cache_alloc() on how
1804 * rt->rt6i_src is updated.)
1805 */
1806 if (res->f6i->fib6_src.plen)
1807 src_key = saddr;
1808 find_ex:
1809 #endif
1810 bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
1811 rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
1812
1813 if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
1814 ret = rt6_ex->rt6i;
1815
1816 #ifdef CONFIG_IPV6_SUBTREES
1817 /* Use fib6_src as src_key and redo lookup */
1818 if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
1819 src_key = &res->f6i->fib6_src.addr;
1820 goto find_ex;
1821 }
1822 #endif
1823
1824 return ret;
1825 }
1826
1827 /* Remove the passed in cached rt from the hash table that contains it */
1828 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
1829 const struct rt6_info *rt)
1830 {
1831 const struct in6_addr *src_key = NULL;
1832 struct rt6_exception_bucket *bucket;
1833 struct rt6_exception *rt6_ex;
1834 int err;
1835
1836 if (!rcu_access_pointer(nh->rt6i_exception_bucket))
1837 return -ENOENT;
1838
1839 spin_lock_bh(&rt6_exception_lock);
1840 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1841
1842 #ifdef CONFIG_IPV6_SUBTREES
1843 /* rt6i_src.plen != 0 indicates 'from' is in subtree
1844 * and exception table is indexed by a hash of
1845 * both rt6i_dst and rt6i_src.
1846 * Otherwise, the exception table is indexed by
1847 * a hash of only rt6i_dst.
1848 */
1849 if (plen)
1850 src_key = &rt->rt6i_src.addr;
1851 #endif
1852 rt6_ex = __rt6_find_exception_spinlock(&bucket,
1853 &rt->rt6i_dst.addr,
1854 src_key);
1855 if (rt6_ex) {
1856 rt6_remove_exception(bucket, rt6_ex);
1857 err = 0;
1858 } else {
1859 err = -ENOENT;
1860 }
1861
1862 spin_unlock_bh(&rt6_exception_lock);
1863 return err;
1864 }
1865
1866 struct fib6_nh_excptn_arg {
1867 struct rt6_info *rt;
1868 int plen;
1869 };
1870
1871 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
1872 {
1873 struct fib6_nh_excptn_arg *arg = _arg;
1874 int err;
1875
1876 err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
1877 if (err == 0)
1878 return 1;
1879
1880 return 0;
1881 }
1882
1883 static int rt6_remove_exception_rt(struct rt6_info *rt)
1884 {
1885 struct fib6_info *from;
1886
1887 from = rcu_dereference(rt->from);
1888 if (!from || !(rt->rt6i_flags & RTF_CACHE))
1889 return -EINVAL;
1890
1891 if (from->nh) {
1892 struct fib6_nh_excptn_arg arg = {
1893 .rt = rt,
1894 .plen = from->fib6_src.plen
1895 };
1896 int rc;
1897
1898 /* rc = 1 means an entry was found */
1899 rc = nexthop_for_each_fib6_nh(from->nh,
1900 rt6_nh_remove_exception_rt,
1901 &arg);
1902 return rc ? 0 : -ENOENT;
1903 }
1904
1905 return fib6_nh_remove_exception(from->fib6_nh,
1906 from->fib6_src.plen, rt);
1907 }
1908
1909 /* Find rt6_ex which contains the passed in rt cache and
1910 * refresh its stamp
1911 */
1912 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
1913 const struct rt6_info *rt)
1914 {
1915 const struct in6_addr *src_key = NULL;
1916 struct rt6_exception_bucket *bucket;
1917 struct rt6_exception *rt6_ex;
1918
1919 bucket = fib6_nh_get_excptn_bucket(nh, NULL);
1920 #ifdef CONFIG_IPV6_SUBTREES
1921 /* rt6i_src.plen != 0 indicates 'from' is in subtree
1922 * and exception table is indexed by a hash of
1923 * both rt6i_dst and rt6i_src.
1924 * Otherwise, the exception table is indexed by
1925 * a hash of only rt6i_dst.
1926 */
1927 if (plen)
1928 src_key = &rt->rt6i_src.addr;
1929 #endif
1930 rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
1931 if (rt6_ex)
1932 rt6_ex->stamp = jiffies;
1933 }
1934
1935 struct fib6_nh_match_arg {
1936 const struct net_device *dev;
1937 const struct in6_addr *gw;
1938 struct fib6_nh *match;
1939 };
1940
1941 /* determine if fib6_nh has given device and gateway */
1942 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
1943 {
1944 struct fib6_nh_match_arg *arg = _arg;
1945
1946 if (arg->dev != nh->fib_nh_dev ||
1947 (arg->gw && !nh->fib_nh_gw_family) ||
1948 (!arg->gw && nh->fib_nh_gw_family) ||
1949 (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
1950 return 0;
1951
1952 arg->match = nh;
1953
1954 /* found a match, break the loop */
1955 return 1;
1956 }
1957
1958 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
1959 {
1960 struct fib6_info *from;
1961 struct fib6_nh *fib6_nh;
1962
1963 rcu_read_lock();
1964
1965 from = rcu_dereference(rt->from);
1966 if (!from || !(rt->rt6i_flags & RTF_CACHE))
1967 goto unlock;
1968
1969 if (from->nh) {
1970 struct fib6_nh_match_arg arg = {
1971 .dev = rt->dst.dev,
1972 .gw = &rt->rt6i_gateway,
1973 };
1974
1975 nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
1976
1977 if (!arg.match)
1978 goto unlock;
1979 fib6_nh = arg.match;
1980 } else {
1981 fib6_nh = from->fib6_nh;
1982 }
1983 fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
1984 unlock:
1985 rcu_read_unlock();
1986 }
1987
1988 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
1989 struct rt6_info *rt, int mtu)
1990 {
1991 /* If the new MTU is lower than the route PMTU, this new MTU will be the
1992 * lowest MTU in the path: always allow updating the route PMTU to
1993 * reflect PMTU decreases.
1994 *
1995 * If the new MTU is higher, and the route PMTU is equal to the local
1996 * MTU, this means the old MTU is the lowest in the path, so allow
1997 * updating it: if other nodes now have lower MTUs, PMTU discovery will
1998 * handle this.
1999 */
2000
2001 if (dst_mtu(&rt->dst) >= mtu)
2002 return true;
2003
2004 if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
2005 return true;
2006
2007 return false;
2008 }
2009
2010 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
2011 const struct fib6_nh *nh, int mtu)
2012 {
2013 struct rt6_exception_bucket *bucket;
2014 struct rt6_exception *rt6_ex;
2015 int i;
2016
2017 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2018 if (!bucket)
2019 return;
2020
2021 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2022 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
2023 struct rt6_info *entry = rt6_ex->rt6i;
2024
2025 /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
2026 * route), the metrics of its rt->from have already
2027 * been updated.
2028 */
2029 if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
2030 rt6_mtu_change_route_allowed(idev, entry, mtu))
2031 dst_metric_set(&entry->dst, RTAX_MTU, mtu);
2032 }
2033 bucket++;
2034 }
2035 }
2036
2037 #define RTF_CACHE_GATEWAY (RTF_GATEWAY | RTF_CACHE)
2038
2039 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
2040 const struct in6_addr *gateway)
2041 {
2042 struct rt6_exception_bucket *bucket;
2043 struct rt6_exception *rt6_ex;
2044 struct hlist_node *tmp;
2045 int i;
2046
2047 if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2048 return;
2049
2050 spin_lock_bh(&rt6_exception_lock);
2051 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2052 if (bucket) {
2053 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2054 hlist_for_each_entry_safe(rt6_ex, tmp,
2055 &bucket->chain, hlist) {
2056 struct rt6_info *entry = rt6_ex->rt6i;
2057
2058 if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
2059 RTF_CACHE_GATEWAY &&
2060 ipv6_addr_equal(gateway,
2061 &entry->rt6i_gateway)) {
2062 rt6_remove_exception(bucket, rt6_ex);
2063 }
2064 }
2065 bucket++;
2066 }
2067 }
2068
2069 spin_unlock_bh(&rt6_exception_lock);
2070 }
2071
2072 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
2073 struct rt6_exception *rt6_ex,
2074 struct fib6_gc_args *gc_args,
2075 unsigned long now)
2076 {
2077 struct rt6_info *rt = rt6_ex->rt6i;
2078
2079 /* we are pruning and obsoleting aged-out and non gateway exceptions
2080 * even if others have still references to them, so that on next
2081 * dst_check() such references can be dropped.
2082 * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
2083 * expired, independently from their aging, as per RFC 8201 section 4
2084 */
2085 if (!(rt->rt6i_flags & RTF_EXPIRES)) {
2086 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
2087 RT6_TRACE("aging clone %p\n", rt);
2088 rt6_remove_exception(bucket, rt6_ex);
2089 return;
2090 }
2091 } else if (time_after(jiffies, rt->dst.expires)) {
2092 RT6_TRACE("purging expired route %p\n", rt);
2093 rt6_remove_exception(bucket, rt6_ex);
2094 return;
2095 }
2096
2097 if (rt->rt6i_flags & RTF_GATEWAY) {
2098 struct neighbour *neigh;
2099
2100 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
2101
2102 if (!(neigh && (neigh->flags & NTF_ROUTER))) {
2103 RT6_TRACE("purging route %p via non-router but gateway\n",
2104 rt);
2105 rt6_remove_exception(bucket, rt6_ex);
2106 return;
2107 }
2108 }
2109
2110 gc_args->more++;
2111 }
2112
2113 static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
2114 struct fib6_gc_args *gc_args,
2115 unsigned long now)
2116 {
2117 struct rt6_exception_bucket *bucket;
2118 struct rt6_exception *rt6_ex;
2119 struct hlist_node *tmp;
2120 int i;
2121
2122 if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2123 return;
2124
2125 rcu_read_lock_bh();
2126 spin_lock(&rt6_exception_lock);
2127 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2128 if (bucket) {
2129 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2130 hlist_for_each_entry_safe(rt6_ex, tmp,
2131 &bucket->chain, hlist) {
2132 rt6_age_examine_exception(bucket, rt6_ex,
2133 gc_args, now);
2134 }
2135 bucket++;
2136 }
2137 }
2138 spin_unlock(&rt6_exception_lock);
2139 rcu_read_unlock_bh();
2140 }
2141
2142 struct fib6_nh_age_excptn_arg {
2143 struct fib6_gc_args *gc_args;
2144 unsigned long now;
2145 };
2146
2147 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
2148 {
2149 struct fib6_nh_age_excptn_arg *arg = _arg;
2150
2151 fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
2152 return 0;
2153 }
2154
2155 void rt6_age_exceptions(struct fib6_info *f6i,
2156 struct fib6_gc_args *gc_args,
2157 unsigned long now)
2158 {
2159 if (f6i->nh) {
2160 struct fib6_nh_age_excptn_arg arg = {
2161 .gc_args = gc_args,
2162 .now = now
2163 };
2164
2165 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
2166 &arg);
2167 } else {
2168 fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
2169 }
2170 }
2171
2172 /* must be called with rcu lock held */
2173 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
2174 struct flowi6 *fl6, struct fib6_result *res, int strict)
2175 {
2176 struct fib6_node *fn, *saved_fn;
2177
2178 fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2179 saved_fn = fn;
2180
2181 if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
2182 oif = 0;
2183
2184 redo_rt6_select:
2185 rt6_select(net, fn, oif, res, strict);
2186 if (res->f6i == net->ipv6.fib6_null_entry) {
2187 fn = fib6_backtrack(fn, &fl6->saddr);
2188 if (fn)
2189 goto redo_rt6_select;
2190 else if (strict & RT6_LOOKUP_F_REACHABLE) {
2191 /* also consider unreachable route */
2192 strict &= ~RT6_LOOKUP_F_REACHABLE;
2193 fn = saved_fn;
2194 goto redo_rt6_select;
2195 }
2196 }
2197
2198 trace_fib6_table_lookup(net, res, table, fl6);
2199
2200 return 0;
2201 }
2202
2203 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
2204 int oif, struct flowi6 *fl6,
2205 const struct sk_buff *skb, int flags)
2206 {
2207 struct fib6_result res = {};
2208 struct rt6_info *rt = NULL;
2209 int strict = 0;
2210
2211 WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
2212 !rcu_read_lock_held());
2213
2214 strict |= flags & RT6_LOOKUP_F_IFACE;
2215 strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
2216 if (net->ipv6.devconf_all->forwarding == 0)
2217 strict |= RT6_LOOKUP_F_REACHABLE;
2218
2219 rcu_read_lock();
2220
2221 fib6_table_lookup(net, table, oif, fl6, &res, strict);
2222 if (res.f6i == net->ipv6.fib6_null_entry)
2223 goto out;
2224
2225 fib6_select_path(net, &res, fl6, oif, false, skb, strict);
2226
2227 /*Search through exception table */
2228 rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
2229 if (rt) {
2230 goto out;
2231 } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
2232 !res.nh->fib_nh_gw_family)) {
2233 /* Create a RTF_CACHE clone which will not be
2234 * owned by the fib6 tree. It is for the special case where
2235 * the daddr in the skb during the neighbor look-up is different
2236 * from the fl6->daddr used to look-up route here.
2237 */
2238 rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
2239
2240 if (rt) {
2241 /* 1 refcnt is taken during ip6_rt_cache_alloc().
2242 * As rt6_uncached_list_add() does not consume refcnt,
2243 * this refcnt is always returned to the caller even
2244 * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
2245 */
2246 rt6_uncached_list_add(rt);
2247 atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
2248 rcu_read_unlock();
2249
2250 return rt;
2251 }
2252 } else {
2253 /* Get a percpu copy */
2254 local_bh_disable();
2255 rt = rt6_get_pcpu_route(&res);
2256
2257 if (!rt)
2258 rt = rt6_make_pcpu_route(net, &res);
2259
2260 local_bh_enable();
2261 }
2262 out:
2263 if (!rt)
2264 rt = net->ipv6.ip6_null_entry;
2265 if (!(flags & RT6_LOOKUP_F_DST_NOREF))
2266 ip6_hold_safe(net, &rt);
2267 rcu_read_unlock();
2268
2269 return rt;
2270 }
2271 EXPORT_SYMBOL_GPL(ip6_pol_route);
2272
2273 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net,
2274 struct fib6_table *table,
2275 struct flowi6 *fl6,
2276 const struct sk_buff *skb,
2277 int flags)
2278 {
2279 return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
2280 }
2281
2282 struct dst_entry *ip6_route_input_lookup(struct net *net,
2283 struct net_device *dev,
2284 struct flowi6 *fl6,
2285 const struct sk_buff *skb,
2286 int flags)
2287 {
2288 if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
2289 flags |= RT6_LOOKUP_F_IFACE;
2290
2291 return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
2292 }
2293 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
2294
2295 static void ip6_multipath_l3_keys(const struct sk_buff *skb,
2296 struct flow_keys *keys,
2297 struct flow_keys *flkeys)
2298 {
2299 const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
2300 const struct ipv6hdr *key_iph = outer_iph;
2301 struct flow_keys *_flkeys = flkeys;
2302 const struct ipv6hdr *inner_iph;
2303 const struct icmp6hdr *icmph;
2304 struct ipv6hdr _inner_iph;
2305 struct icmp6hdr _icmph;
2306
2307 if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
2308 goto out;
2309
2310 icmph = skb_header_pointer(skb, skb_transport_offset(skb),
2311 sizeof(_icmph), &_icmph);
2312 if (!icmph)
2313 goto out;
2314
2315 if (!icmpv6_is_err(icmph->icmp6_type))
2316 goto out;
2317
2318 inner_iph = skb_header_pointer(skb,
2319 skb_transport_offset(skb) + sizeof(*icmph),
2320 sizeof(_inner_iph), &_inner_iph);
2321 if (!inner_iph)
2322 goto out;
2323
2324 key_iph = inner_iph;
2325 _flkeys = NULL;
2326 out:
2327 if (_flkeys) {
2328 keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
2329 keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
2330 keys->tags.flow_label = _flkeys->tags.flow_label;
2331 keys->basic.ip_proto = _flkeys->basic.ip_proto;
2332 } else {
2333 keys->addrs.v6addrs.src = key_iph->saddr;
2334 keys->addrs.v6addrs.dst = key_iph->daddr;
2335 keys->tags.flow_label = ip6_flowlabel(key_iph);
2336 keys->basic.ip_proto = key_iph->nexthdr;
2337 }
2338 }
2339
2340 static u32 rt6_multipath_custom_hash_outer(const struct net *net,
2341 const struct sk_buff *skb,
2342 bool *p_has_inner)
2343 {
2344 u32 hash_fields = ip6_multipath_hash_fields(net);
2345 struct flow_keys keys, hash_keys;
2346
2347 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2348 return 0;
2349
2350 memset(&hash_keys, 0, sizeof(hash_keys));
2351 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
2352
2353 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2354 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2355 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2356 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2357 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2358 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2359 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2360 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2361 hash_keys.tags.flow_label = keys.tags.flow_label;
2362 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2363 hash_keys.ports.src = keys.ports.src;
2364 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2365 hash_keys.ports.dst = keys.ports.dst;
2366
2367 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
2368 return flow_hash_from_keys(&hash_keys);
2369 }
2370
2371 static u32 rt6_multipath_custom_hash_inner(const struct net *net,
2372 const struct sk_buff *skb,
2373 bool has_inner)
2374 {
2375 u32 hash_fields = ip6_multipath_hash_fields(net);
2376 struct flow_keys keys, hash_keys;
2377
2378 /* We assume the packet carries an encapsulation, but if none was
2379 * encountered during dissection of the outer flow, then there is no
2380 * point in calling the flow dissector again.
2381 */
2382 if (!has_inner)
2383 return 0;
2384
2385 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
2386 return 0;
2387
2388 memset(&hash_keys, 0, sizeof(hash_keys));
2389 skb_flow_dissect_flow_keys(skb, &keys, 0);
2390
2391 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
2392 return 0;
2393
2394 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2395 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2396 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2397 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2398 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2399 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2400 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2401 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2402 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2403 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2404 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2405 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2406 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
2407 hash_keys.tags.flow_label = keys.tags.flow_label;
2408 }
2409
2410 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
2411 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2412 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
2413 hash_keys.ports.src = keys.ports.src;
2414 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
2415 hash_keys.ports.dst = keys.ports.dst;
2416
2417 return flow_hash_from_keys(&hash_keys);
2418 }
2419
2420 static u32 rt6_multipath_custom_hash_skb(const struct net *net,
2421 const struct sk_buff *skb)
2422 {
2423 u32 mhash, mhash_inner;
2424 bool has_inner = true;
2425
2426 mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner);
2427 mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner);
2428
2429 return jhash_2words(mhash, mhash_inner, 0);
2430 }
2431
2432 static u32 rt6_multipath_custom_hash_fl6(const struct net *net,
2433 const struct flowi6 *fl6)
2434 {
2435 u32 hash_fields = ip6_multipath_hash_fields(net);
2436 struct flow_keys hash_keys;
2437
2438 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2439 return 0;
2440
2441 memset(&hash_keys, 0, sizeof(hash_keys));
2442 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2443 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2444 hash_keys.addrs.v6addrs.src = fl6->saddr;
2445 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2446 hash_keys.addrs.v6addrs.dst = fl6->daddr;
2447 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2448 hash_keys.basic.ip_proto = fl6->flowi6_proto;
2449 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2450 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2451 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2452 hash_keys.ports.src = fl6->fl6_sport;
2453 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2454 hash_keys.ports.dst = fl6->fl6_dport;
2455
2456 return flow_hash_from_keys(&hash_keys);
2457 }
2458
2459 /* if skb is set it will be used and fl6 can be NULL */
2460 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
2461 const struct sk_buff *skb, struct flow_keys *flkeys)
2462 {
2463 struct flow_keys hash_keys;
2464 u32 mhash = 0;
2465
2466 switch (ip6_multipath_hash_policy(net)) {
2467 case 0:
2468 memset(&hash_keys, 0, sizeof(hash_keys));
2469 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2470 if (skb) {
2471 ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2472 } else {
2473 hash_keys.addrs.v6addrs.src = fl6->saddr;
2474 hash_keys.addrs.v6addrs.dst = fl6->daddr;
2475 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2476 hash_keys.basic.ip_proto = fl6->flowi6_proto;
2477 }
2478 mhash = flow_hash_from_keys(&hash_keys);
2479 break;
2480 case 1:
2481 if (skb) {
2482 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2483 struct flow_keys keys;
2484
2485 /* short-circuit if we already have L4 hash present */
2486 if (skb->l4_hash)
2487 return skb_get_hash_raw(skb) >> 1;
2488
2489 memset(&hash_keys, 0, sizeof(hash_keys));
2490
2491 if (!flkeys) {
2492 skb_flow_dissect_flow_keys(skb, &keys, flag);
2493 flkeys = &keys;
2494 }
2495 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2496 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2497 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2498 hash_keys.ports.src = flkeys->ports.src;
2499 hash_keys.ports.dst = flkeys->ports.dst;
2500 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2501 } else {
2502 memset(&hash_keys, 0, sizeof(hash_keys));
2503 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2504 hash_keys.addrs.v6addrs.src = fl6->saddr;
2505 hash_keys.addrs.v6addrs.dst = fl6->daddr;
2506 hash_keys.ports.src = fl6->fl6_sport;
2507 hash_keys.ports.dst = fl6->fl6_dport;
2508 hash_keys.basic.ip_proto = fl6->flowi6_proto;
2509 }
2510 mhash = flow_hash_from_keys(&hash_keys);
2511 break;
2512 case 2:
2513 memset(&hash_keys, 0, sizeof(hash_keys));
2514 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2515 if (skb) {
2516 struct flow_keys keys;
2517
2518 if (!flkeys) {
2519 skb_flow_dissect_flow_keys(skb, &keys, 0);
2520 flkeys = &keys;
2521 }
2522
2523 /* Inner can be v4 or v6 */
2524 if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2525 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2526 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2527 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2528 } else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2529 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2530 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2531 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2532 hash_keys.tags.flow_label = flkeys->tags.flow_label;
2533 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2534 } else {
2535 /* Same as case 0 */
2536 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2537 ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2538 }
2539 } else {
2540 /* Same as case 0 */
2541 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2542 hash_keys.addrs.v6addrs.src = fl6->saddr;
2543 hash_keys.addrs.v6addrs.dst = fl6->daddr;
2544 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2545 hash_keys.basic.ip_proto = fl6->flowi6_proto;
2546 }
2547 mhash = flow_hash_from_keys(&hash_keys);
2548 break;
2549 case 3:
2550 if (skb)
2551 mhash = rt6_multipath_custom_hash_skb(net, skb);
2552 else
2553 mhash = rt6_multipath_custom_hash_fl6(net, fl6);
2554 break;
2555 }
2556
2557 return mhash >> 1;
2558 }
2559
2560 /* Called with rcu held */
2561 void ip6_route_input(struct sk_buff *skb)
2562 {
2563 const struct ipv6hdr *iph = ipv6_hdr(skb);
2564 struct net *net = dev_net(skb->dev);
2565 int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
2566 struct ip_tunnel_info *tun_info;
2567 struct flowi6 fl6 = {
2568 .flowi6_iif = skb->dev->ifindex,
2569 .daddr = iph->daddr,
2570 .saddr = iph->saddr,
2571 .flowlabel = ip6_flowinfo(iph),
2572 .flowi6_mark = skb->mark,
2573 .flowi6_proto = iph->nexthdr,
2574 };
2575 struct flow_keys *flkeys = NULL, _flkeys;
2576
2577 tun_info = skb_tunnel_info(skb);
2578 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2579 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
2580
2581 if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
2582 flkeys = &_flkeys;
2583
2584 if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
2585 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
2586 skb_dst_drop(skb);
2587 skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
2588 &fl6, skb, flags));
2589 }
2590
2591 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net,
2592 struct fib6_table *table,
2593 struct flowi6 *fl6,
2594 const struct sk_buff *skb,
2595 int flags)
2596 {
2597 return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
2598 }
2599
2600 struct dst_entry *ip6_route_output_flags_noref(struct net *net,
2601 const struct sock *sk,
2602 struct flowi6 *fl6, int flags)
2603 {
2604 bool any_src;
2605
2606 if (ipv6_addr_type(&fl6->daddr) &
2607 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
2608 struct dst_entry *dst;
2609
2610 /* This function does not take refcnt on the dst */
2611 dst = l3mdev_link_scope_lookup(net, fl6);
2612 if (dst)
2613 return dst;
2614 }
2615
2616 fl6->flowi6_iif = LOOPBACK_IFINDEX;
2617
2618 flags |= RT6_LOOKUP_F_DST_NOREF;
2619 any_src = ipv6_addr_any(&fl6->saddr);
2620 if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
2621 (fl6->flowi6_oif && any_src))
2622 flags |= RT6_LOOKUP_F_IFACE;
2623
2624 if (!any_src)
2625 flags |= RT6_LOOKUP_F_HAS_SADDR;
2626 else if (sk)
2627 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
2628
2629 return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
2630 }
2631 EXPORT_SYMBOL_GPL(ip6_route_output_flags_noref);
2632
2633 struct dst_entry *ip6_route_output_flags(struct net *net,
2634 const struct sock *sk,
2635 struct flowi6 *fl6,
2636 int flags)
2637 {
2638 struct dst_entry *dst;
2639 struct rt6_info *rt6;
2640
2641 rcu_read_lock();
2642 dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
2643 rt6 = (struct rt6_info *)dst;
2644 /* For dst cached in uncached_list, refcnt is already taken. */
2645 if (list_empty(&rt6->rt6i_uncached) && !dst_hold_safe(dst)) {
2646 dst = &net->ipv6.ip6_null_entry->dst;
2647 dst_hold(dst);
2648 }
2649 rcu_read_unlock();
2650
2651 return dst;
2652 }
2653 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
2654
2655 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2656 {
2657 struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
2658 struct net_device *loopback_dev = net->loopback_dev;
2659 struct dst_entry *new = NULL;
2660
2661 rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
2662 DST_OBSOLETE_DEAD, 0);
2663 if (rt) {
2664 rt6_info_init(rt);
2665 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
2666
2667 new = &rt->dst;
2668 new->__use = 1;
2669 new->input = dst_discard;
2670 new->output = dst_discard_out;
2671
2672 dst_copy_metrics(new, &ort->dst);
2673
2674 rt->rt6i_idev = in6_dev_get(loopback_dev);
2675 rt->rt6i_gateway = ort->rt6i_gateway;
2676 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
2677
2678 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
2679 #ifdef CONFIG_IPV6_SUBTREES
2680 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
2681 #endif
2682 }
2683
2684 dst_release(dst_orig);
2685 return new ? new : ERR_PTR(-ENOMEM);
2686 }
2687
2688 /*
2689 * Destination cache support functions
2690 */
2691
2692 static bool fib6_check(struct fib6_info *f6i, u32 cookie)
2693 {
2694 u32 rt_cookie = 0;
2695
2696 if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
2697 return false;
2698
2699 if (fib6_check_expired(f6i))
2700 return false;
2701
2702 return true;
2703 }
2704
2705 static struct dst_entry *rt6_check(struct rt6_info *rt,
2706 struct fib6_info *from,
2707 u32 cookie)
2708 {
2709 u32 rt_cookie = 0;
2710
2711 if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
2712 rt_cookie != cookie)
2713 return NULL;
2714
2715 if (rt6_check_expired(rt))
2716 return NULL;
2717
2718 return &rt->dst;
2719 }
2720
2721 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
2722 struct fib6_info *from,
2723 u32 cookie)
2724 {
2725 if (!__rt6_check_expired(rt) &&
2726 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
2727 fib6_check(from, cookie))
2728 return &rt->dst;
2729 else
2730 return NULL;
2731 }
2732
2733 INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
2734 u32 cookie)
2735 {
2736 struct dst_entry *dst_ret;
2737 struct fib6_info *from;
2738 struct rt6_info *rt;
2739
2740 rt = container_of(dst, struct rt6_info, dst);
2741
2742 if (rt->sernum)
2743 return rt6_is_valid(rt) ? dst : NULL;
2744
2745 rcu_read_lock();
2746
2747 /* All IPV6 dsts are created with ->obsolete set to the value
2748 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
2749 * into this function always.
2750 */
2751
2752 from = rcu_dereference(rt->from);
2753
2754 if (from && (rt->rt6i_flags & RTF_PCPU ||
2755 unlikely(!list_empty(&rt->rt6i_uncached))))
2756 dst_ret = rt6_dst_from_check(rt, from, cookie);
2757 else
2758 dst_ret = rt6_check(rt, from, cookie);
2759
2760 rcu_read_unlock();
2761
2762 return dst_ret;
2763 }
2764 EXPORT_INDIRECT_CALLABLE(ip6_dst_check);
2765
2766 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
2767 {
2768 struct rt6_info *rt = (struct rt6_info *) dst;
2769
2770 if (rt) {
2771 if (rt->rt6i_flags & RTF_CACHE) {
2772 rcu_read_lock();
2773 if (rt6_check_expired(rt)) {
2774 rt6_remove_exception_rt(rt);
2775 dst = NULL;
2776 }
2777 rcu_read_unlock();
2778 } else {
2779 dst_release(dst);
2780 dst = NULL;
2781 }
2782 }
2783 return dst;
2784 }
2785
2786 static void ip6_link_failure(struct sk_buff *skb)
2787 {
2788 struct rt6_info *rt;
2789
2790 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
2791
2792 rt = (struct rt6_info *) skb_dst(skb);
2793 if (rt) {
2794 rcu_read_lock();
2795 if (rt->rt6i_flags & RTF_CACHE) {
2796 rt6_remove_exception_rt(rt);
2797 } else {
2798 struct fib6_info *from;
2799 struct fib6_node *fn;
2800
2801 from = rcu_dereference(rt->from);
2802 if (from) {
2803 fn = rcu_dereference(from->fib6_node);
2804 if (fn && (rt->rt6i_flags & RTF_DEFAULT))
2805 WRITE_ONCE(fn->fn_sernum, -1);
2806 }
2807 }
2808 rcu_read_unlock();
2809 }
2810 }
2811
2812 static void rt6_update_expires(struct rt6_info *rt0, int timeout)
2813 {
2814 if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
2815 struct fib6_info *from;
2816
2817 rcu_read_lock();
2818 from = rcu_dereference(rt0->from);
2819 if (from)
2820 rt0->dst.expires = from->expires;
2821 rcu_read_unlock();
2822 }
2823
2824 dst_set_expires(&rt0->dst, timeout);
2825 rt0->rt6i_flags |= RTF_EXPIRES;
2826 }
2827
2828 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
2829 {
2830 struct net *net = dev_net(rt->dst.dev);
2831
2832 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
2833 rt->rt6i_flags |= RTF_MODIFIED;
2834 rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
2835 }
2836
2837 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
2838 {
2839 return !(rt->rt6i_flags & RTF_CACHE) &&
2840 (rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
2841 }
2842
2843 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
2844 const struct ipv6hdr *iph, u32 mtu,
2845 bool confirm_neigh)
2846 {
2847 const struct in6_addr *daddr, *saddr;
2848 struct rt6_info *rt6 = (struct rt6_info *)dst;
2849
2850 /* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU)
2851 * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it.
2852 * [see also comment in rt6_mtu_change_route()]
2853 */
2854
2855 if (iph) {
2856 daddr = &iph->daddr;
2857 saddr = &iph->saddr;
2858 } else if (sk) {
2859 daddr = &sk->sk_v6_daddr;
2860 saddr = &inet6_sk(sk)->saddr;
2861 } else {
2862 daddr = NULL;
2863 saddr = NULL;
2864 }
2865
2866 if (confirm_neigh)
2867 dst_confirm_neigh(dst, daddr);
2868
2869 if (mtu < IPV6_MIN_MTU)
2870 return;
2871 if (mtu >= dst_mtu(dst))
2872 return;
2873
2874 if (!rt6_cache_allowed_for_pmtu(rt6)) {
2875 rt6_do_update_pmtu(rt6, mtu);
2876 /* update rt6_ex->stamp for cache */
2877 if (rt6->rt6i_flags & RTF_CACHE)
2878 rt6_update_exception_stamp_rt(rt6);
2879 } else if (daddr) {
2880 struct fib6_result res = {};
2881 struct rt6_info *nrt6;
2882
2883 rcu_read_lock();
2884 res.f6i = rcu_dereference(rt6->from);
2885 if (!res.f6i)
2886 goto out_unlock;
2887
2888 res.fib6_flags = res.f6i->fib6_flags;
2889 res.fib6_type = res.f6i->fib6_type;
2890
2891 if (res.f6i->nh) {
2892 struct fib6_nh_match_arg arg = {
2893 .dev = dst->dev,
2894 .gw = &rt6->rt6i_gateway,
2895 };
2896
2897 nexthop_for_each_fib6_nh(res.f6i->nh,
2898 fib6_nh_find_match, &arg);
2899
2900 /* fib6_info uses a nexthop that does not have fib6_nh
2901 * using the dst->dev + gw. Should be impossible.
2902 */
2903 if (!arg.match)
2904 goto out_unlock;
2905
2906 res.nh = arg.match;
2907 } else {
2908 res.nh = res.f6i->fib6_nh;
2909 }
2910
2911 nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
2912 if (nrt6) {
2913 rt6_do_update_pmtu(nrt6, mtu);
2914 if (rt6_insert_exception(nrt6, &res))
2915 dst_release_immediate(&nrt6->dst);
2916 }
2917 out_unlock:
2918 rcu_read_unlock();
2919 }
2920 }
2921
2922 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
2923 struct sk_buff *skb, u32 mtu,
2924 bool confirm_neigh)
2925 {
2926 __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
2927 confirm_neigh);
2928 }
2929
2930 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
2931 int oif, u32 mark, kuid_t uid)
2932 {
2933 const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2934 struct dst_entry *dst;
2935 struct flowi6 fl6 = {
2936 .flowi6_oif = oif,
2937 .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
2938 .daddr = iph->daddr,
2939 .saddr = iph->saddr,
2940 .flowlabel = ip6_flowinfo(iph),
2941 .flowi6_uid = uid,
2942 };
2943
2944 dst = ip6_route_output(net, NULL, &fl6);
2945 if (!dst->error)
2946 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
2947 dst_release(dst);
2948 }
2949 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
2950
2951 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
2952 {
2953 int oif = sk->sk_bound_dev_if;
2954 struct dst_entry *dst;
2955
2956 if (!oif && skb->dev)
2957 oif = l3mdev_master_ifindex(skb->dev);
2958
2959 ip6_update_pmtu(skb, sock_net(sk), mtu, oif, sk->sk_mark, sk->sk_uid);
2960
2961 dst = __sk_dst_get(sk);
2962 if (!dst || !dst->obsolete ||
2963 dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
2964 return;
2965
2966 bh_lock_sock(sk);
2967 if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
2968 ip6_datagram_dst_update(sk, false);
2969 bh_unlock_sock(sk);
2970 }
2971 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
2972
2973 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
2974 const struct flowi6 *fl6)
2975 {
2976 #ifdef CONFIG_IPV6_SUBTREES
2977 struct ipv6_pinfo *np = inet6_sk(sk);
2978 #endif
2979
2980 ip6_dst_store(sk, dst,
2981 ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
2982 &sk->sk_v6_daddr : NULL,
2983 #ifdef CONFIG_IPV6_SUBTREES
2984 ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
2985 &np->saddr :
2986 #endif
2987 NULL);
2988 }
2989
2990 static bool ip6_redirect_nh_match(const struct fib6_result *res,
2991 struct flowi6 *fl6,
2992 const struct in6_addr *gw,
2993 struct rt6_info **ret)
2994 {
2995 const struct fib6_nh *nh = res->nh;
2996
2997 if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
2998 fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
2999 return false;
3000
3001 /* rt_cache's gateway might be different from its 'parent'
3002 * in the case of an ip redirect.
3003 * So we keep searching in the exception table if the gateway
3004 * is different.
3005 */
3006 if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
3007 struct rt6_info *rt_cache;
3008
3009 rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
3010 if (rt_cache &&
3011 ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
3012 *ret = rt_cache;
3013 return true;
3014 }
3015 return false;
3016 }
3017 return true;
3018 }
3019
3020 struct fib6_nh_rd_arg {
3021 struct fib6_result *res;
3022 struct flowi6 *fl6;
3023 const struct in6_addr *gw;
3024 struct rt6_info **ret;
3025 };
3026
3027 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
3028 {
3029 struct fib6_nh_rd_arg *arg = _arg;
3030
3031 arg->res->nh = nh;
3032 return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
3033 }
3034
3035 /* Handle redirects */
3036 struct ip6rd_flowi {
3037 struct flowi6 fl6;
3038 struct in6_addr gateway;
3039 };
3040
3041 INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
3042 struct fib6_table *table,
3043 struct flowi6 *fl6,
3044 const struct sk_buff *skb,
3045 int flags)
3046 {
3047 struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
3048 struct rt6_info *ret = NULL;
3049 struct fib6_result res = {};
3050 struct fib6_nh_rd_arg arg = {
3051 .res = &res,
3052 .fl6 = fl6,
3053 .gw = &rdfl->gateway,
3054 .ret = &ret
3055 };
3056 struct fib6_info *rt;
3057 struct fib6_node *fn;
3058
3059 /* l3mdev_update_flow overrides oif if the device is enslaved; in
3060 * this case we must match on the real ingress device, so reset it
3061 */
3062 if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
3063 fl6->flowi6_oif = skb->dev->ifindex;
3064
3065 /* Get the "current" route for this destination and
3066 * check if the redirect has come from appropriate router.
3067 *
3068 * RFC 4861 specifies that redirects should only be
3069 * accepted if they come from the nexthop to the target.
3070 * Due to the way the routes are chosen, this notion
3071 * is a bit fuzzy and one might need to check all possible
3072 * routes.
3073 */
3074
3075 rcu_read_lock();
3076 fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
3077 restart:
3078 for_each_fib6_node_rt_rcu(fn) {
3079 res.f6i = rt;
3080 if (fib6_check_expired(rt))
3081 continue;
3082 if (rt->fib6_flags & RTF_REJECT)
3083 break;
3084 if (unlikely(rt->nh)) {
3085 if (nexthop_is_blackhole(rt->nh))
3086 continue;
3087 /* on match, res->nh is filled in and potentially ret */
3088 if (nexthop_for_each_fib6_nh(rt->nh,
3089 fib6_nh_redirect_match,
3090 &arg))
3091 goto out;
3092 } else {
3093 res.nh = rt->fib6_nh;
3094 if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
3095 &ret))
3096 goto out;
3097 }
3098 }
3099
3100 if (!rt)
3101 rt = net->ipv6.fib6_null_entry;
3102 else if (rt->fib6_flags & RTF_REJECT) {
3103 ret = net->ipv6.ip6_null_entry;
3104 goto out;
3105 }
3106
3107 if (rt == net->ipv6.fib6_null_entry) {
3108 fn = fib6_backtrack(fn, &fl6->saddr);
3109 if (fn)
3110 goto restart;
3111 }
3112
3113 res.f6i = rt;
3114 res.nh = rt->fib6_nh;
3115 out:
3116 if (ret) {
3117 ip6_hold_safe(net, &ret);
3118 } else {
3119 res.fib6_flags = res.f6i->fib6_flags;
3120 res.fib6_type = res.f6i->fib6_type;
3121 ret = ip6_create_rt_rcu(&res);
3122 }
3123
3124 rcu_read_unlock();
3125
3126 trace_fib6_table_lookup(net, &res, table, fl6);
3127 return ret;
3128 };
3129
3130 static struct dst_entry *ip6_route_redirect(struct net *net,
3131 const struct flowi6 *fl6,
3132 const struct sk_buff *skb,
3133 const struct in6_addr *gateway)
3134 {
3135 int flags = RT6_LOOKUP_F_HAS_SADDR;
3136 struct ip6rd_flowi rdfl;
3137
3138 rdfl.fl6 = *fl6;
3139 rdfl.gateway = *gateway;
3140
3141 return fib6_rule_lookup(net, &rdfl.fl6, skb,
3142 flags, __ip6_route_redirect);
3143 }
3144
3145 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
3146 kuid_t uid)
3147 {
3148 const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
3149 struct dst_entry *dst;
3150 struct flowi6 fl6 = {
3151 .flowi6_iif = LOOPBACK_IFINDEX,
3152 .flowi6_oif = oif,
3153 .flowi6_mark = mark,
3154 .daddr = iph->daddr,
3155 .saddr = iph->saddr,
3156 .flowlabel = ip6_flowinfo(iph),
3157 .flowi6_uid = uid,
3158 };
3159
3160 dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
3161 rt6_do_redirect(dst, NULL, skb);
3162 dst_release(dst);
3163 }
3164 EXPORT_SYMBOL_GPL(ip6_redirect);
3165
3166 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
3167 {
3168 const struct ipv6hdr *iph = ipv6_hdr(skb);
3169 const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
3170 struct dst_entry *dst;
3171 struct flowi6 fl6 = {
3172 .flowi6_iif = LOOPBACK_IFINDEX,
3173 .flowi6_oif = oif,
3174 .daddr = msg->dest,
3175 .saddr = iph->daddr,
3176 .flowi6_uid = sock_net_uid(net, NULL),
3177 };
3178
3179 dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
3180 rt6_do_redirect(dst, NULL, skb);
3181 dst_release(dst);
3182 }
3183
3184 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
3185 {
3186 ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark,
3187 sk->sk_uid);
3188 }
3189 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
3190
3191 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
3192 {
3193 struct net_device *dev = dst->dev;
3194 unsigned int mtu = dst_mtu(dst);
3195 struct net *net = dev_net(dev);
3196
3197 mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
3198
3199 if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
3200 mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
3201
3202 /*
3203 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
3204 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
3205 * IPV6_MAXPLEN is also valid and means: "any MSS,
3206 * rely only on pmtu discovery"
3207 */
3208 if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
3209 mtu = IPV6_MAXPLEN;
3210 return mtu;
3211 }
3212
3213 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
3214 {
3215 return ip6_dst_mtu_maybe_forward(dst, false);
3216 }
3217 EXPORT_INDIRECT_CALLABLE(ip6_mtu);
3218
3219 /* MTU selection:
3220 * 1. mtu on route is locked - use it
3221 * 2. mtu from nexthop exception
3222 * 3. mtu from egress device
3223 *
3224 * based on ip6_dst_mtu_forward and exception logic of
3225 * rt6_find_cached_rt; called with rcu_read_lock
3226 */
3227 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
3228 const struct in6_addr *daddr,
3229 const struct in6_addr *saddr)
3230 {
3231 const struct fib6_nh *nh = res->nh;
3232 struct fib6_info *f6i = res->f6i;
3233 struct inet6_dev *idev;
3234 struct rt6_info *rt;
3235 u32 mtu = 0;
3236
3237 if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
3238 mtu = f6i->fib6_pmtu;
3239 if (mtu)
3240 goto out;
3241 }
3242
3243 rt = rt6_find_cached_rt(res, daddr, saddr);
3244 if (unlikely(rt)) {
3245 mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
3246 } else {
3247 struct net_device *dev = nh->fib_nh_dev;
3248
3249 mtu = IPV6_MIN_MTU;
3250 idev = __in6_dev_get(dev);
3251 if (idev && idev->cnf.mtu6 > mtu)
3252 mtu = idev->cnf.mtu6;
3253 }
3254
3255 mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
3256 out:
3257 return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
3258 }
3259
3260 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
3261 struct flowi6 *fl6)
3262 {
3263 struct dst_entry *dst;
3264 struct rt6_info *rt;
3265 struct inet6_dev *idev = in6_dev_get(dev);
3266 struct net *net = dev_net(dev);
3267
3268 if (unlikely(!idev))
3269 return ERR_PTR(-ENODEV);
3270
3271 rt = ip6_dst_alloc(net, dev, 0);
3272 if (unlikely(!rt)) {
3273 in6_dev_put(idev);
3274 dst = ERR_PTR(-ENOMEM);
3275 goto out;
3276 }
3277
3278 rt->dst.input = ip6_input;
3279 rt->dst.output = ip6_output;
3280 rt->rt6i_gateway = fl6->daddr;
3281 rt->rt6i_dst.addr = fl6->daddr;
3282 rt->rt6i_dst.plen = 128;
3283 rt->rt6i_idev = idev;
3284 dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
3285
3286 /* Add this dst into uncached_list so that rt6_disable_ip() can
3287 * do proper release of the net_device
3288 */
3289 rt6_uncached_list_add(rt);
3290 atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
3291
3292 dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
3293
3294 out:
3295 return dst;
3296 }
3297
3298 static int ip6_dst_gc(struct dst_ops *ops)
3299 {
3300 struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
3301 int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
3302 int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
3303 int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
3304 int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
3305 unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
3306 int entries;
3307
3308 entries = dst_entries_get_fast(ops);
3309 if (entries > rt_max_size)
3310 entries = dst_entries_get_slow(ops);
3311
3312 if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
3313 entries <= rt_max_size)
3314 goto out;
3315
3316 net->ipv6.ip6_rt_gc_expire++;
3317 fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net, true);
3318 entries = dst_entries_get_slow(ops);
3319 if (entries < ops->gc_thresh)
3320 net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
3321 out:
3322 net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
3323 return entries > rt_max_size;
3324 }
3325
3326 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
3327 const struct in6_addr *gw_addr, u32 tbid,
3328 int flags, struct fib6_result *res)
3329 {
3330 struct flowi6 fl6 = {
3331 .flowi6_oif = cfg->fc_ifindex,
3332 .daddr = *gw_addr,
3333 .saddr = cfg->fc_prefsrc,
3334 };
3335 struct fib6_table *table;
3336 int err;
3337
3338 table = fib6_get_table(net, tbid);
3339 if (!table)
3340 return -EINVAL;
3341
3342 if (!ipv6_addr_any(&cfg->fc_prefsrc))
3343 flags |= RT6_LOOKUP_F_HAS_SADDR;
3344
3345 flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
3346
3347 err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
3348 if (!err && res->f6i != net->ipv6.fib6_null_entry)
3349 fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
3350 cfg->fc_ifindex != 0, NULL, flags);
3351
3352 return err;
3353 }
3354
3355 static int ip6_route_check_nh_onlink(struct net *net,
3356 struct fib6_config *cfg,
3357 const struct net_device *dev,
3358 struct netlink_ext_ack *extack)
3359 {
3360 u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
3361 const struct in6_addr *gw_addr = &cfg->fc_gateway;
3362 struct fib6_result res = {};
3363 int err;
3364
3365 err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
3366 if (!err && !(res.fib6_flags & RTF_REJECT) &&
3367 /* ignore match if it is the default route */
3368 !ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
3369 (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
3370 NL_SET_ERR_MSG(extack,
3371 "Nexthop has invalid gateway or device mismatch");
3372 err = -EINVAL;
3373 }
3374
3375 return err;
3376 }
3377
3378 static int ip6_route_check_nh(struct net *net,
3379 struct fib6_config *cfg,
3380 struct net_device **_dev,
3381 struct inet6_dev **idev)
3382 {
3383 const struct in6_addr *gw_addr = &cfg->fc_gateway;
3384 struct net_device *dev = _dev ? *_dev : NULL;
3385 int flags = RT6_LOOKUP_F_IFACE;
3386 struct fib6_result res = {};
3387 int err = -EHOSTUNREACH;
3388
3389 if (cfg->fc_table) {
3390 err = ip6_nh_lookup_table(net, cfg, gw_addr,
3391 cfg->fc_table, flags, &res);
3392 /* gw_addr can not require a gateway or resolve to a reject
3393 * route. If a device is given, it must match the result.
3394 */
3395 if (err || res.fib6_flags & RTF_REJECT ||
3396 res.nh->fib_nh_gw_family ||
3397 (dev && dev != res.nh->fib_nh_dev))
3398 err = -EHOSTUNREACH;
3399 }
3400
3401 if (err < 0) {
3402 struct flowi6 fl6 = {
3403 .flowi6_oif = cfg->fc_ifindex,
3404 .daddr = *gw_addr,
3405 };
3406
3407 err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
3408 if (err || res.fib6_flags & RTF_REJECT ||
3409 res.nh->fib_nh_gw_family)
3410 err = -EHOSTUNREACH;
3411
3412 if (err)
3413 return err;
3414
3415 fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
3416 cfg->fc_ifindex != 0, NULL, flags);
3417 }
3418
3419 err = 0;
3420 if (dev) {
3421 if (dev != res.nh->fib_nh_dev)
3422 err = -EHOSTUNREACH;
3423 } else {
3424 *_dev = dev = res.nh->fib_nh_dev;
3425 dev_hold(dev);
3426 *idev = in6_dev_get(dev);
3427 }
3428
3429 return err;
3430 }
3431
3432 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
3433 struct net_device **_dev, struct inet6_dev **idev,
3434 struct netlink_ext_ack *extack)
3435 {
3436 const struct in6_addr *gw_addr = &cfg->fc_gateway;
3437 int gwa_type = ipv6_addr_type(gw_addr);
3438 bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
3439 const struct net_device *dev = *_dev;
3440 bool need_addr_check = !dev;
3441 int err = -EINVAL;
3442
3443 /* if gw_addr is local we will fail to detect this in case
3444 * address is still TENTATIVE (DAD in progress). rt6_lookup()
3445 * will return already-added prefix route via interface that
3446 * prefix route was assigned to, which might be non-loopback.
3447 */
3448 if (dev &&
3449 ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3450 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3451 goto out;
3452 }
3453
3454 if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
3455 /* IPv6 strictly inhibits using not link-local
3456 * addresses as nexthop address.
3457 * Otherwise, router will not able to send redirects.
3458 * It is very good, but in some (rare!) circumstances
3459 * (SIT, PtP, NBMA NOARP links) it is handy to allow
3460 * some exceptions. --ANK
3461 * We allow IPv4-mapped nexthops to support RFC4798-type
3462 * addressing
3463 */
3464 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
3465 NL_SET_ERR_MSG(extack, "Invalid gateway address");
3466 goto out;
3467 }
3468
3469 rcu_read_lock();
3470
3471 if (cfg->fc_flags & RTNH_F_ONLINK)
3472 err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
3473 else
3474 err = ip6_route_check_nh(net, cfg, _dev, idev);
3475
3476 rcu_read_unlock();
3477
3478 if (err)
3479 goto out;
3480 }
3481
3482 /* reload in case device was changed */
3483 dev = *_dev;
3484
3485 err = -EINVAL;
3486 if (!dev) {
3487 NL_SET_ERR_MSG(extack, "Egress device not specified");
3488 goto out;
3489 } else if (dev->flags & IFF_LOOPBACK) {
3490 NL_SET_ERR_MSG(extack,
3491 "Egress device can not be loopback device for this route");
3492 goto out;
3493 }
3494
3495 /* if we did not check gw_addr above, do so now that the
3496 * egress device has been resolved.
3497 */
3498 if (need_addr_check &&
3499 ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3500 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3501 goto out;
3502 }
3503
3504 err = 0;
3505 out:
3506 return err;
3507 }
3508
3509 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
3510 {
3511 if ((flags & RTF_REJECT) ||
3512 (dev && (dev->flags & IFF_LOOPBACK) &&
3513 !(addr_type & IPV6_ADDR_LOOPBACK) &&
3514 !(flags & (RTF_ANYCAST | RTF_LOCAL))))
3515 return true;
3516
3517 return false;
3518 }
3519
3520 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
3521 struct fib6_config *cfg, gfp_t gfp_flags,
3522 struct netlink_ext_ack *extack)
3523 {
3524 struct net_device *dev = NULL;
3525 struct inet6_dev *idev = NULL;
3526 int addr_type;
3527 int err;
3528
3529 fib6_nh->fib_nh_family = AF_INET6;
3530 #ifdef CONFIG_IPV6_ROUTER_PREF
3531 fib6_nh->last_probe = jiffies;
3532 #endif
3533 if (cfg->fc_is_fdb) {
3534 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3535 fib6_nh->fib_nh_gw_family = AF_INET6;
3536 return 0;
3537 }
3538
3539 err = -ENODEV;
3540 if (cfg->fc_ifindex) {
3541 dev = dev_get_by_index(net, cfg->fc_ifindex);
3542 if (!dev)
3543 goto out;
3544 idev = in6_dev_get(dev);
3545 if (!idev)
3546 goto out;
3547 }
3548
3549 if (cfg->fc_flags & RTNH_F_ONLINK) {
3550 if (!dev) {
3551 NL_SET_ERR_MSG(extack,
3552 "Nexthop device required for onlink");
3553 goto out;
3554 }
3555
3556 if (!(dev->flags & IFF_UP)) {
3557 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3558 err = -ENETDOWN;
3559 goto out;
3560 }
3561
3562 fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
3563 }
3564
3565 fib6_nh->fib_nh_weight = 1;
3566
3567 /* We cannot add true routes via loopback here,
3568 * they would result in kernel looping; promote them to reject routes
3569 */
3570 addr_type = ipv6_addr_type(&cfg->fc_dst);
3571 if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
3572 /* hold loopback dev/idev if we haven't done so. */
3573 if (dev != net->loopback_dev) {
3574 if (dev) {
3575 dev_put(dev);
3576 in6_dev_put(idev);
3577 }
3578 dev = net->loopback_dev;
3579 dev_hold(dev);
3580 idev = in6_dev_get(dev);
3581 if (!idev) {
3582 err = -ENODEV;
3583 goto out;
3584 }
3585 }
3586 goto pcpu_alloc;
3587 }
3588
3589 if (cfg->fc_flags & RTF_GATEWAY) {
3590 err = ip6_validate_gw(net, cfg, &dev, &idev, extack);
3591 if (err)
3592 goto out;
3593
3594 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3595 fib6_nh->fib_nh_gw_family = AF_INET6;
3596 }
3597
3598 err = -ENODEV;
3599 if (!dev)
3600 goto out;
3601
3602 if (idev->cnf.disable_ipv6) {
3603 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3604 err = -EACCES;
3605 goto out;
3606 }
3607
3608 if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
3609 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3610 err = -ENETDOWN;
3611 goto out;
3612 }
3613
3614 if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3615 !netif_carrier_ok(dev))
3616 fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
3617
3618 err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap,
3619 cfg->fc_encap_type, cfg, gfp_flags, extack);
3620 if (err)
3621 goto out;
3622
3623 pcpu_alloc:
3624 fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
3625 if (!fib6_nh->rt6i_pcpu) {
3626 err = -ENOMEM;
3627 goto out;
3628 }
3629
3630 fib6_nh->fib_nh_dev = dev;
3631 fib6_nh->fib_nh_oif = dev->ifindex;
3632 err = 0;
3633 out:
3634 if (idev)
3635 in6_dev_put(idev);
3636
3637 if (err) {
3638 lwtstate_put(fib6_nh->fib_nh_lws);
3639 fib6_nh->fib_nh_lws = NULL;
3640 dev_put(dev);
3641 }
3642
3643 return err;
3644 }
3645
3646 void fib6_nh_release(struct fib6_nh *fib6_nh)
3647 {
3648 struct rt6_exception_bucket *bucket;
3649
3650 rcu_read_lock();
3651
3652 fib6_nh_flush_exceptions(fib6_nh, NULL);
3653 bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL);
3654 if (bucket) {
3655 rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL);
3656 kfree(bucket);
3657 }
3658
3659 rcu_read_unlock();
3660
3661 if (fib6_nh->rt6i_pcpu) {
3662 int cpu;
3663
3664 for_each_possible_cpu(cpu) {
3665 struct rt6_info **ppcpu_rt;
3666 struct rt6_info *pcpu_rt;
3667
3668 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
3669 pcpu_rt = *ppcpu_rt;
3670 if (pcpu_rt) {
3671 dst_dev_put(&pcpu_rt->dst);
3672 dst_release(&pcpu_rt->dst);
3673 *ppcpu_rt = NULL;
3674 }
3675 }
3676
3677 free_percpu(fib6_nh->rt6i_pcpu);
3678 }
3679
3680 fib_nh_common_release(&fib6_nh->nh_common);
3681 }
3682
3683 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh)
3684 {
3685 int cpu;
3686
3687 if (!fib6_nh->rt6i_pcpu)
3688 return;
3689
3690 for_each_possible_cpu(cpu) {
3691 struct rt6_info *pcpu_rt, **ppcpu_rt;
3692
3693 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
3694 pcpu_rt = xchg(ppcpu_rt, NULL);
3695 if (pcpu_rt) {
3696 dst_dev_put(&pcpu_rt->dst);
3697 dst_release(&pcpu_rt->dst);
3698 }
3699 }
3700 }
3701
3702 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
3703 gfp_t gfp_flags,
3704 struct netlink_ext_ack *extack)
3705 {
3706 struct net *net = cfg->fc_nlinfo.nl_net;
3707 struct fib6_info *rt = NULL;
3708 struct nexthop *nh = NULL;
3709 struct fib6_table *table;
3710 struct fib6_nh *fib6_nh;
3711 int err = -EINVAL;
3712 int addr_type;
3713
3714 /* RTF_PCPU is an internal flag; can not be set by userspace */
3715 if (cfg->fc_flags & RTF_PCPU) {
3716 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
3717 goto out;
3718 }
3719
3720 /* RTF_CACHE is an internal flag; can not be set by userspace */
3721 if (cfg->fc_flags & RTF_CACHE) {
3722 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
3723 goto out;
3724 }
3725
3726 if (cfg->fc_type > RTN_MAX) {
3727 NL_SET_ERR_MSG(extack, "Invalid route type");
3728 goto out;
3729 }
3730
3731 if (cfg->fc_dst_len > 128) {
3732 NL_SET_ERR_MSG(extack, "Invalid prefix length");
3733 goto out;
3734 }
3735 if (cfg->fc_src_len > 128) {
3736 NL_SET_ERR_MSG(extack, "Invalid source address length");
3737 goto out;
3738 }
3739 #ifndef CONFIG_IPV6_SUBTREES
3740 if (cfg->fc_src_len) {
3741 NL_SET_ERR_MSG(extack,
3742 "Specifying source address requires IPV6_SUBTREES to be enabled");
3743 goto out;
3744 }
3745 #endif
3746 if (cfg->fc_nh_id) {
3747 nh = nexthop_find_by_id(net, cfg->fc_nh_id);
3748 if (!nh) {
3749 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
3750 goto out;
3751 }
3752 err = fib6_check_nexthop(nh, cfg, extack);
3753 if (err)
3754 goto out;
3755 }
3756
3757 err = -ENOBUFS;
3758 if (cfg->fc_nlinfo.nlh &&
3759 !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
3760 table = fib6_get_table(net, cfg->fc_table);
3761 if (!table) {
3762 pr_warn("NLM_F_CREATE should be specified when creating new route\n");
3763 table = fib6_new_table(net, cfg->fc_table);
3764 }
3765 } else {
3766 table = fib6_new_table(net, cfg->fc_table);
3767 }
3768
3769 if (!table)
3770 goto out;
3771
3772 err = -ENOMEM;
3773 rt = fib6_info_alloc(gfp_flags, !nh);
3774 if (!rt)
3775 goto out;
3776
3777 rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len,
3778 extack);
3779 if (IS_ERR(rt->fib6_metrics)) {
3780 err = PTR_ERR(rt->fib6_metrics);
3781 /* Do not leave garbage there. */
3782 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
3783 goto out_free;
3784 }
3785
3786 if (cfg->fc_flags & RTF_ADDRCONF)
3787 rt->dst_nocount = true;
3788
3789 if (cfg->fc_flags & RTF_EXPIRES)
3790 fib6_set_expires(rt, jiffies +
3791 clock_t_to_jiffies(cfg->fc_expires));
3792 else
3793 fib6_clean_expires(rt);
3794
3795 if (cfg->fc_protocol == RTPROT_UNSPEC)
3796 cfg->fc_protocol = RTPROT_BOOT;
3797 rt->fib6_protocol = cfg->fc_protocol;
3798
3799 rt->fib6_table = table;
3800 rt->fib6_metric = cfg->fc_metric;
3801 rt->fib6_type = cfg->fc_type ? : RTN_UNICAST;
3802 rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;
3803
3804 ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
3805 rt->fib6_dst.plen = cfg->fc_dst_len;
3806
3807 #ifdef CONFIG_IPV6_SUBTREES
3808 ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
3809 rt->fib6_src.plen = cfg->fc_src_len;
3810 #endif
3811 if (nh) {
3812 if (rt->fib6_src.plen) {
3813 NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
3814 goto out_free;
3815 }
3816 if (!nexthop_get(nh)) {
3817 NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
3818 goto out_free;
3819 }
3820 rt->nh = nh;
3821 fib6_nh = nexthop_fib6_nh(rt->nh);
3822 } else {
3823 err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
3824 if (err)
3825 goto out;
3826
3827 fib6_nh = rt->fib6_nh;
3828
3829 /* We cannot add true routes via loopback here, they would
3830 * result in kernel looping; promote them to reject routes
3831 */
3832 addr_type = ipv6_addr_type(&cfg->fc_dst);
3833 if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev,
3834 addr_type))
3835 rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
3836 }
3837
3838 if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
3839 struct net_device *dev = fib6_nh->fib_nh_dev;
3840
3841 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
3842 NL_SET_ERR_MSG(extack, "Invalid source address");
3843 err = -EINVAL;
3844 goto out;
3845 }
3846 rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
3847 rt->fib6_prefsrc.plen = 128;
3848 } else
3849 rt->fib6_prefsrc.plen = 0;
3850
3851 return rt;
3852 out:
3853 fib6_info_release(rt);
3854 return ERR_PTR(err);
3855 out_free:
3856 ip_fib_metrics_put(rt->fib6_metrics);
3857 kfree(rt);
3858 return ERR_PTR(err);
3859 }
3860
3861 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
3862 struct netlink_ext_ack *extack)
3863 {
3864 struct fib6_info *rt;
3865 int err;
3866
3867 rt = ip6_route_info_create(cfg, gfp_flags, extack);
3868 if (IS_ERR(rt))
3869 return PTR_ERR(rt);
3870
3871 err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
3872 fib6_info_release(rt);
3873
3874 return err;
3875 }
3876
3877 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
3878 {
3879 struct net *net = info->nl_net;
3880 struct fib6_table *table;
3881 int err;
3882
3883 if (rt == net->ipv6.fib6_null_entry) {
3884 err = -ENOENT;
3885 goto out;
3886 }
3887
3888 table = rt->fib6_table;
3889 spin_lock_bh(&table->tb6_lock);
3890 err = fib6_del(rt, info);
3891 spin_unlock_bh(&table->tb6_lock);
3892
3893 out:
3894 fib6_info_release(rt);
3895 return err;
3896 }
3897
3898 int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify)
3899 {
3900 struct nl_info info = {
3901 .nl_net = net,
3902 .skip_notify = skip_notify
3903 };
3904
3905 return __ip6_del_rt(rt, &info);
3906 }
3907
3908 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
3909 {
3910 struct nl_info *info = &cfg->fc_nlinfo;
3911 struct net *net = info->nl_net;
3912 struct sk_buff *skb = NULL;
3913 struct fib6_table *table;
3914 int err = -ENOENT;
3915
3916 if (rt == net->ipv6.fib6_null_entry)
3917 goto out_put;
3918 table = rt->fib6_table;
3919 spin_lock_bh(&table->tb6_lock);
3920
3921 if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
3922 struct fib6_info *sibling, *next_sibling;
3923 struct fib6_node *fn;
3924
3925 /* prefer to send a single notification with all hops */
3926 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3927 if (skb) {
3928 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3929
3930 if (rt6_fill_node(net, skb, rt, NULL,
3931 NULL, NULL, 0, RTM_DELROUTE,
3932 info->portid, seq, 0) < 0) {
3933 kfree_skb(skb);
3934 skb = NULL;
3935 } else
3936 info->skip_notify = 1;
3937 }
3938
3939 /* 'rt' points to the first sibling route. If it is not the
3940 * leaf, then we do not need to send a notification. Otherwise,
3941 * we need to check if the last sibling has a next route or not
3942 * and emit a replace or delete notification, respectively.
3943 */
3944 info->skip_notify_kernel = 1;
3945 fn = rcu_dereference_protected(rt->fib6_node,
3946 lockdep_is_held(&table->tb6_lock));
3947 if (rcu_access_pointer(fn->leaf) == rt) {
3948 struct fib6_info *last_sibling, *replace_rt;
3949
3950 last_sibling = list_last_entry(&rt->fib6_siblings,
3951 struct fib6_info,
3952 fib6_siblings);
3953 replace_rt = rcu_dereference_protected(
3954 last_sibling->fib6_next,
3955 lockdep_is_held(&table->tb6_lock));
3956 if (replace_rt)
3957 call_fib6_entry_notifiers_replace(net,
3958 replace_rt);
3959 else
3960 call_fib6_multipath_entry_notifiers(net,
3961 FIB_EVENT_ENTRY_DEL,
3962 rt, rt->fib6_nsiblings,
3963 NULL);
3964 }
3965 list_for_each_entry_safe(sibling, next_sibling,
3966 &rt->fib6_siblings,
3967 fib6_siblings) {
3968 err = fib6_del(sibling, info);
3969 if (err)
3970 goto out_unlock;
3971 }
3972 }
3973
3974 err = fib6_del(rt, info);
3975 out_unlock:
3976 spin_unlock_bh(&table->tb6_lock);
3977 out_put:
3978 fib6_info_release(rt);
3979
3980 if (skb) {
3981 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3982 info->nlh, gfp_any());
3983 }
3984 return err;
3985 }
3986
3987 static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
3988 {
3989 int rc = -ESRCH;
3990
3991 if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
3992 goto out;
3993
3994 if (cfg->fc_flags & RTF_GATEWAY &&
3995 !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
3996 goto out;
3997
3998 rc = rt6_remove_exception_rt(rt);
3999 out:
4000 return rc;
4001 }
4002
4003 static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt,
4004 struct fib6_nh *nh)
4005 {
4006 struct fib6_result res = {
4007 .f6i = rt,
4008 .nh = nh,
4009 };
4010 struct rt6_info *rt_cache;
4011
4012 rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src);
4013 if (rt_cache)
4014 return __ip6_del_cached_rt(rt_cache, cfg);
4015
4016 return 0;
4017 }
4018
4019 struct fib6_nh_del_cached_rt_arg {
4020 struct fib6_config *cfg;
4021 struct fib6_info *f6i;
4022 };
4023
4024 static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)
4025 {
4026 struct fib6_nh_del_cached_rt_arg *arg = _arg;
4027 int rc;
4028
4029 rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);
4030 return rc != -ESRCH ? rc : 0;
4031 }
4032
4033 static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)
4034 {
4035 struct fib6_nh_del_cached_rt_arg arg = {
4036 .cfg = cfg,
4037 .f6i = f6i
4038 };
4039
4040 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);
4041 }
4042
4043 static int ip6_route_del(struct fib6_config *cfg,
4044 struct netlink_ext_ack *extack)
4045 {
4046 struct fib6_table *table;
4047 struct fib6_info *rt;
4048 struct fib6_node *fn;
4049 int err = -ESRCH;
4050
4051 table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
4052 if (!table) {
4053 NL_SET_ERR_MSG(extack, "FIB table does not exist");
4054 return err;
4055 }
4056
4057 rcu_read_lock();
4058
4059 fn = fib6_locate(&table->tb6_root,
4060 &cfg->fc_dst, cfg->fc_dst_len,
4061 &cfg->fc_src, cfg->fc_src_len,
4062 !(cfg->fc_flags & RTF_CACHE));
4063
4064 if (fn) {
4065 for_each_fib6_node_rt_rcu(fn) {
4066 struct fib6_nh *nh;
4067
4068 if (rt->nh && cfg->fc_nh_id &&
4069 rt->nh->id != cfg->fc_nh_id)
4070 continue;
4071
4072 if (cfg->fc_flags & RTF_CACHE) {
4073 int rc = 0;
4074
4075 if (rt->nh) {
4076 rc = ip6_del_cached_rt_nh(cfg, rt);
4077 } else if (cfg->fc_nh_id) {
4078 continue;
4079 } else {
4080 nh = rt->fib6_nh;
4081 rc = ip6_del_cached_rt(cfg, rt, nh);
4082 }
4083 if (rc != -ESRCH) {
4084 rcu_read_unlock();
4085 return rc;
4086 }
4087 continue;
4088 }
4089
4090 if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
4091 continue;
4092 if (cfg->fc_protocol &&
4093 cfg->fc_protocol != rt->fib6_protocol)
4094 continue;
4095
4096 if (rt->nh) {
4097 if (!fib6_info_hold_safe(rt))
4098 continue;
4099 rcu_read_unlock();
4100
4101 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4102 }
4103 if (cfg->fc_nh_id)
4104 continue;
4105
4106 nh = rt->fib6_nh;
4107 if (cfg->fc_ifindex &&
4108 (!nh->fib_nh_dev ||
4109 nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
4110 continue;
4111 if (cfg->fc_flags & RTF_GATEWAY &&
4112 !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))
4113 continue;
4114 if (!fib6_info_hold_safe(rt))
4115 continue;
4116 rcu_read_unlock();
4117
4118 /* if gateway was specified only delete the one hop */
4119 if (cfg->fc_flags & RTF_GATEWAY)
4120 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4121
4122 return __ip6_del_rt_siblings(rt, cfg);
4123 }
4124 }
4125 rcu_read_unlock();
4126
4127 return err;
4128 }
4129
4130 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
4131 {
4132 struct netevent_redirect netevent;
4133 struct rt6_info *rt, *nrt = NULL;
4134 struct fib6_result res = {};
4135 struct ndisc_options ndopts;
4136 struct inet6_dev *in6_dev;
4137 struct neighbour *neigh;
4138 struct rd_msg *msg;
4139 int optlen, on_link;
4140 u8 *lladdr;
4141
4142 optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
4143 optlen -= sizeof(*msg);
4144
4145 if (optlen < 0) {
4146 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
4147 return;
4148 }
4149
4150 msg = (struct rd_msg *)icmp6_hdr(skb);
4151
4152 if (ipv6_addr_is_multicast(&msg->dest)) {
4153 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
4154 return;
4155 }
4156
4157 on_link = 0;
4158 if (ipv6_addr_equal(&msg->dest, &msg->target)) {
4159 on_link = 1;
4160 } else if (ipv6_addr_type(&msg->target) !=
4161 (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
4162 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
4163 return;
4164 }
4165
4166 in6_dev = __in6_dev_get(skb->dev);
4167 if (!in6_dev)
4168 return;
4169 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
4170 return;
4171
4172 /* RFC2461 8.1:
4173 * The IP source address of the Redirect MUST be the same as the current
4174 * first-hop router for the specified ICMP Destination Address.
4175 */
4176
4177 if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
4178 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
4179 return;
4180 }
4181
4182 lladdr = NULL;
4183 if (ndopts.nd_opts_tgt_lladdr) {
4184 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
4185 skb->dev);
4186 if (!lladdr) {
4187 net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
4188 return;
4189 }
4190 }
4191
4192 rt = (struct rt6_info *) dst;
4193 if (rt->rt6i_flags & RTF_REJECT) {
4194 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
4195 return;
4196 }
4197
4198 /* Redirect received -> path was valid.
4199 * Look, redirects are sent only in response to data packets,
4200 * so that this nexthop apparently is reachable. --ANK
4201 */
4202 dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
4203
4204 neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
4205 if (!neigh)
4206 return;
4207
4208 /*
4209 * We have finally decided to accept it.
4210 */
4211
4212 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
4213 NEIGH_UPDATE_F_WEAK_OVERRIDE|
4214 NEIGH_UPDATE_F_OVERRIDE|
4215 (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
4216 NEIGH_UPDATE_F_ISROUTER)),
4217 NDISC_REDIRECT, &ndopts);
4218
4219 rcu_read_lock();
4220 res.f6i = rcu_dereference(rt->from);
4221 if (!res.f6i)
4222 goto out;
4223
4224 if (res.f6i->nh) {
4225 struct fib6_nh_match_arg arg = {
4226 .dev = dst->dev,
4227 .gw = &rt->rt6i_gateway,
4228 };
4229
4230 nexthop_for_each_fib6_nh(res.f6i->nh,
4231 fib6_nh_find_match, &arg);
4232
4233 /* fib6_info uses a nexthop that does not have fib6_nh
4234 * using the dst->dev. Should be impossible
4235 */
4236 if (!arg.match)
4237 goto out;
4238 res.nh = arg.match;
4239 } else {
4240 res.nh = res.f6i->fib6_nh;
4241 }
4242
4243 res.fib6_flags = res.f6i->fib6_flags;
4244 res.fib6_type = res.f6i->fib6_type;
4245 nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
4246 if (!nrt)
4247 goto out;
4248
4249 nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
4250 if (on_link)
4251 nrt->rt6i_flags &= ~RTF_GATEWAY;
4252
4253 nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
4254
4255 /* rt6_insert_exception() will take care of duplicated exceptions */
4256 if (rt6_insert_exception(nrt, &res)) {
4257 dst_release_immediate(&nrt->dst);
4258 goto out;
4259 }
4260
4261 netevent.old = &rt->dst;
4262 netevent.new = &nrt->dst;
4263 netevent.daddr = &msg->dest;
4264 netevent.neigh = neigh;
4265 call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
4266
4267 out:
4268 rcu_read_unlock();
4269 neigh_release(neigh);
4270 }
4271
4272 #ifdef CONFIG_IPV6_ROUTE_INFO
4273 static struct fib6_info *rt6_get_route_info(struct net *net,
4274 const struct in6_addr *prefix, int prefixlen,
4275 const struct in6_addr *gwaddr,
4276 struct net_device *dev)
4277 {
4278 u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4279 int ifindex = dev->ifindex;
4280 struct fib6_node *fn;
4281 struct fib6_info *rt = NULL;
4282 struct fib6_table *table;
4283
4284 table = fib6_get_table(net, tb_id);
4285 if (!table)
4286 return NULL;
4287
4288 rcu_read_lock();
4289 fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
4290 if (!fn)
4291 goto out;
4292
4293 for_each_fib6_node_rt_rcu(fn) {
4294 /* these routes do not use nexthops */
4295 if (rt->nh)
4296 continue;
4297 if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
4298 continue;
4299 if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
4300 !rt->fib6_nh->fib_nh_gw_family)
4301 continue;
4302 if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
4303 continue;
4304 if (!fib6_info_hold_safe(rt))
4305 continue;
4306 break;
4307 }
4308 out:
4309 rcu_read_unlock();
4310 return rt;
4311 }
4312
4313 static struct fib6_info *rt6_add_route_info(struct net *net,
4314 const struct in6_addr *prefix, int prefixlen,
4315 const struct in6_addr *gwaddr,
4316 struct net_device *dev,
4317 unsigned int pref)
4318 {
4319 struct fib6_config cfg = {
4320 .fc_metric = IP6_RT_PRIO_USER,
4321 .fc_ifindex = dev->ifindex,
4322 .fc_dst_len = prefixlen,
4323 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
4324 RTF_UP | RTF_PREF(pref),
4325 .fc_protocol = RTPROT_RA,
4326 .fc_type = RTN_UNICAST,
4327 .fc_nlinfo.portid = 0,
4328 .fc_nlinfo.nlh = NULL,
4329 .fc_nlinfo.nl_net = net,
4330 };
4331
4332 cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4333 cfg.fc_dst = *prefix;
4334 cfg.fc_gateway = *gwaddr;
4335
4336 /* We should treat it as a default route if prefix length is 0. */
4337 if (!prefixlen)
4338 cfg.fc_flags |= RTF_DEFAULT;
4339
4340 ip6_route_add(&cfg, GFP_ATOMIC, NULL);
4341
4342 return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
4343 }
4344 #endif
4345
4346 struct fib6_info *rt6_get_dflt_router(struct net *net,
4347 const struct in6_addr *addr,
4348 struct net_device *dev)
4349 {
4350 u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
4351 struct fib6_info *rt;
4352 struct fib6_table *table;
4353
4354 table = fib6_get_table(net, tb_id);
4355 if (!table)
4356 return NULL;
4357
4358 rcu_read_lock();
4359 for_each_fib6_node_rt_rcu(&table->tb6_root) {
4360 struct fib6_nh *nh;
4361
4362 /* RA routes do not use nexthops */
4363 if (rt->nh)
4364 continue;
4365
4366 nh = rt->fib6_nh;
4367 if (dev == nh->fib_nh_dev &&
4368 ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
4369 ipv6_addr_equal(&nh->fib_nh_gw6, addr))
4370 break;
4371 }
4372 if (rt && !fib6_info_hold_safe(rt))
4373 rt = NULL;
4374 rcu_read_unlock();
4375 return rt;
4376 }
4377
4378 struct fib6_info *rt6_add_dflt_router(struct net *net,
4379 const struct in6_addr *gwaddr,
4380 struct net_device *dev,
4381 unsigned int pref,
4382 u32 defrtr_usr_metric)
4383 {
4384 struct fib6_config cfg = {
4385 .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
4386 .fc_metric = defrtr_usr_metric,
4387 .fc_ifindex = dev->ifindex,
4388 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
4389 RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
4390 .fc_protocol = RTPROT_RA,
4391 .fc_type = RTN_UNICAST,
4392 .fc_nlinfo.portid = 0,
4393 .fc_nlinfo.nlh = NULL,
4394 .fc_nlinfo.nl_net = net,
4395 };
4396
4397 cfg.fc_gateway = *gwaddr;
4398
4399 if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
4400 struct fib6_table *table;
4401
4402 table = fib6_get_table(dev_net(dev), cfg.fc_table);
4403 if (table)
4404 table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
4405 }
4406
4407 return rt6_get_dflt_router(net, gwaddr, dev);
4408 }
4409
4410 static void __rt6_purge_dflt_routers(struct net *net,
4411 struct fib6_table *table)
4412 {
4413 struct fib6_info *rt;
4414
4415 restart:
4416 rcu_read_lock();
4417 for_each_fib6_node_rt_rcu(&table->tb6_root) {
4418 struct net_device *dev = fib6_info_nh_dev(rt);
4419 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
4420
4421 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
4422 (!idev || idev->cnf.accept_ra != 2) &&
4423 fib6_info_hold_safe(rt)) {
4424 rcu_read_unlock();
4425 ip6_del_rt(net, rt, false);
4426 goto restart;
4427 }
4428 }
4429 rcu_read_unlock();
4430
4431 table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
4432 }
4433
4434 void rt6_purge_dflt_routers(struct net *net)
4435 {
4436 struct fib6_table *table;
4437 struct hlist_head *head;
4438 unsigned int h;
4439
4440 rcu_read_lock();
4441
4442 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
4443 head = &net->ipv6.fib_table_hash[h];
4444 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
4445 if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
4446 __rt6_purge_dflt_routers(net, table);
4447 }
4448 }
4449
4450 rcu_read_unlock();
4451 }
4452
4453 static void rtmsg_to_fib6_config(struct net *net,
4454 struct in6_rtmsg *rtmsg,
4455 struct fib6_config *cfg)
4456 {
4457 *cfg = (struct fib6_config){
4458 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
4459 : RT6_TABLE_MAIN,
4460 .fc_ifindex = rtmsg->rtmsg_ifindex,
4461 .fc_metric = rtmsg->rtmsg_metric ? : IP6_RT_PRIO_USER,
4462 .fc_expires = rtmsg->rtmsg_info,
4463 .fc_dst_len = rtmsg->rtmsg_dst_len,
4464 .fc_src_len = rtmsg->rtmsg_src_len,
4465 .fc_flags = rtmsg->rtmsg_flags,
4466 .fc_type = rtmsg->rtmsg_type,
4467
4468 .fc_nlinfo.nl_net = net,
4469
4470 .fc_dst = rtmsg->rtmsg_dst,
4471 .fc_src = rtmsg->rtmsg_src,
4472 .fc_gateway = rtmsg->rtmsg_gateway,
4473 };
4474 }
4475
4476 int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg)
4477 {
4478 struct fib6_config cfg;
4479 int err;
4480
4481 if (cmd != SIOCADDRT && cmd != SIOCDELRT)
4482 return -EINVAL;
4483 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
4484 return -EPERM;
4485
4486 rtmsg_to_fib6_config(net, rtmsg, &cfg);
4487
4488 rtnl_lock();
4489 switch (cmd) {
4490 case SIOCADDRT:
4491 err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
4492 break;
4493 case SIOCDELRT:
4494 err = ip6_route_del(&cfg, NULL);
4495 break;
4496 }
4497 rtnl_unlock();
4498 return err;
4499 }
4500
4501 /*
4502 * Drop the packet on the floor
4503 */
4504
4505 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
4506 {
4507 struct dst_entry *dst = skb_dst(skb);
4508 struct net *net = dev_net(dst->dev);
4509 struct inet6_dev *idev;
4510 int type;
4511
4512 if (netif_is_l3_master(skb->dev) &&
4513 dst->dev == net->loopback_dev)
4514 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
4515 else
4516 idev = ip6_dst_idev(dst);
4517
4518 switch (ipstats_mib_noroutes) {
4519 case IPSTATS_MIB_INNOROUTES:
4520 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
4521 if (type == IPV6_ADDR_ANY) {
4522 IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
4523 break;
4524 }
4525 fallthrough;
4526 case IPSTATS_MIB_OUTNOROUTES:
4527 IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
4528 break;
4529 }
4530
4531 /* Start over by dropping the dst for l3mdev case */
4532 if (netif_is_l3_master(skb->dev))
4533 skb_dst_drop(skb);
4534
4535 icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
4536 kfree_skb(skb);
4537 return 0;
4538 }
4539
4540 static int ip6_pkt_discard(struct sk_buff *skb)
4541 {
4542 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
4543 }
4544
4545 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4546 {
4547 skb->dev = skb_dst(skb)->dev;
4548 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
4549 }
4550
4551 static int ip6_pkt_prohibit(struct sk_buff *skb)
4552 {
4553 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
4554 }
4555
4556 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4557 {
4558 skb->dev = skb_dst(skb)->dev;
4559 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
4560 }
4561
4562 /*
4563 * Allocate a dst for local (unicast / anycast) address.
4564 */
4565
4566 struct fib6_info *addrconf_f6i_alloc(struct net *net,
4567 struct inet6_dev *idev,
4568 const struct in6_addr *addr,
4569 bool anycast, gfp_t gfp_flags)
4570 {
4571 struct fib6_config cfg = {
4572 .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
4573 .fc_ifindex = idev->dev->ifindex,
4574 .fc_flags = RTF_UP | RTF_NONEXTHOP,
4575 .fc_dst = *addr,
4576 .fc_dst_len = 128,
4577 .fc_protocol = RTPROT_KERNEL,
4578 .fc_nlinfo.nl_net = net,
4579 .fc_ignore_dev_down = true,
4580 };
4581 struct fib6_info *f6i;
4582
4583 if (anycast) {
4584 cfg.fc_type = RTN_ANYCAST;
4585 cfg.fc_flags |= RTF_ANYCAST;
4586 } else {
4587 cfg.fc_type = RTN_LOCAL;
4588 cfg.fc_flags |= RTF_LOCAL;
4589 }
4590
4591 f6i = ip6_route_info_create(&cfg, gfp_flags, NULL);
4592 if (!IS_ERR(f6i))
4593 f6i->dst_nocount = true;
4594 return f6i;
4595 }
4596
4597 /* remove deleted ip from prefsrc entries */
4598 struct arg_dev_net_ip {
4599 struct net_device *dev;
4600 struct net *net;
4601 struct in6_addr *addr;
4602 };
4603
4604 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
4605 {
4606 struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
4607 struct net *net = ((struct arg_dev_net_ip *)arg)->net;
4608 struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
4609
4610 if (!rt->nh &&
4611 ((void *)rt->fib6_nh->fib_nh_dev == dev || !dev) &&
4612 rt != net->ipv6.fib6_null_entry &&
4613 ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr)) {
4614 spin_lock_bh(&rt6_exception_lock);
4615 /* remove prefsrc entry */
4616 rt->fib6_prefsrc.plen = 0;
4617 spin_unlock_bh(&rt6_exception_lock);
4618 }
4619 return 0;
4620 }
4621
4622 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
4623 {
4624 struct net *net = dev_net(ifp->idev->dev);
4625 struct arg_dev_net_ip adni = {
4626 .dev = ifp->idev->dev,
4627 .net = net,
4628 .addr = &ifp->addr,
4629 };
4630 fib6_clean_all(net, fib6_remove_prefsrc, &adni);
4631 }
4632
4633 #define RTF_RA_ROUTER (RTF_ADDRCONF | RTF_DEFAULT)
4634
4635 /* Remove routers and update dst entries when gateway turn into host. */
4636 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
4637 {
4638 struct in6_addr *gateway = (struct in6_addr *)arg;
4639 struct fib6_nh *nh;
4640
4641 /* RA routes do not use nexthops */
4642 if (rt->nh)
4643 return 0;
4644
4645 nh = rt->fib6_nh;
4646 if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
4647 nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
4648 return -1;
4649
4650 /* Further clean up cached routes in exception table.
4651 * This is needed because cached route may have a different
4652 * gateway than its 'parent' in the case of an ip redirect.
4653 */
4654 fib6_nh_exceptions_clean_tohost(nh, gateway);
4655
4656 return 0;
4657 }
4658
4659 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
4660 {
4661 fib6_clean_all(net, fib6_clean_tohost, gateway);
4662 }
4663
4664 struct arg_netdev_event {
4665 const struct net_device *dev;
4666 union {
4667 unsigned char nh_flags;
4668 unsigned long event;
4669 };
4670 };
4671
4672 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
4673 {
4674 struct fib6_info *iter;
4675 struct fib6_node *fn;
4676
4677 fn = rcu_dereference_protected(rt->fib6_node,
4678 lockdep_is_held(&rt->fib6_table->tb6_lock));
4679 iter = rcu_dereference_protected(fn->leaf,
4680 lockdep_is_held(&rt->fib6_table->tb6_lock));
4681 while (iter) {
4682 if (iter->fib6_metric == rt->fib6_metric &&
4683 rt6_qualify_for_ecmp(iter))
4684 return iter;
4685 iter = rcu_dereference_protected(iter->fib6_next,
4686 lockdep_is_held(&rt->fib6_table->tb6_lock));
4687 }
4688
4689 return NULL;
4690 }
4691
4692 /* only called for fib entries with builtin fib6_nh */
4693 static bool rt6_is_dead(const struct fib6_info *rt)
4694 {
4695 if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
4696 (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
4697 ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
4698 return true;
4699
4700 return false;
4701 }
4702
4703 static int rt6_multipath_total_weight(const struct fib6_info *rt)
4704 {
4705 struct fib6_info *iter;
4706 int total = 0;
4707
4708 if (!rt6_is_dead(rt))
4709 total += rt->fib6_nh->fib_nh_weight;
4710
4711 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
4712 if (!rt6_is_dead(iter))
4713 total += iter->fib6_nh->fib_nh_weight;
4714 }
4715
4716 return total;
4717 }
4718
4719 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
4720 {
4721 int upper_bound = -1;
4722
4723 if (!rt6_is_dead(rt)) {
4724 *weight += rt->fib6_nh->fib_nh_weight;
4725 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
4726 total) - 1;
4727 }
4728 atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
4729 }
4730
4731 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
4732 {
4733 struct fib6_info *iter;
4734 int weight = 0;
4735
4736 rt6_upper_bound_set(rt, &weight, total);
4737
4738 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4739 rt6_upper_bound_set(iter, &weight, total);
4740 }
4741
4742 void rt6_multipath_rebalance(struct fib6_info *rt)
4743 {
4744 struct fib6_info *first;
4745 int total;
4746
4747 /* In case the entire multipath route was marked for flushing,
4748 * then there is no need to rebalance upon the removal of every
4749 * sibling route.
4750 */
4751 if (!rt->fib6_nsiblings || rt->should_flush)
4752 return;
4753
4754 /* During lookup routes are evaluated in order, so we need to
4755 * make sure upper bounds are assigned from the first sibling
4756 * onwards.
4757 */
4758 first = rt6_multipath_first_sibling(rt);
4759 if (WARN_ON_ONCE(!first))
4760 return;
4761
4762 total = rt6_multipath_total_weight(first);
4763 rt6_multipath_upper_bound_set(first, total);
4764 }
4765
4766 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
4767 {
4768 const struct arg_netdev_event *arg = p_arg;
4769 struct net *net = dev_net(arg->dev);
4770
4771 if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
4772 rt->fib6_nh->fib_nh_dev == arg->dev) {
4773 rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
4774 fib6_update_sernum_upto_root(net, rt);
4775 rt6_multipath_rebalance(rt);
4776 }
4777
4778 return 0;
4779 }
4780
4781 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
4782 {
4783 struct arg_netdev_event arg = {
4784 .dev = dev,
4785 {
4786 .nh_flags = nh_flags,
4787 },
4788 };
4789
4790 if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
4791 arg.nh_flags |= RTNH_F_LINKDOWN;
4792
4793 fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
4794 }
4795
4796 /* only called for fib entries with inline fib6_nh */
4797 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
4798 const struct net_device *dev)
4799 {
4800 struct fib6_info *iter;
4801
4802 if (rt->fib6_nh->fib_nh_dev == dev)
4803 return true;
4804 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4805 if (iter->fib6_nh->fib_nh_dev == dev)
4806 return true;
4807
4808 return false;
4809 }
4810
4811 static void rt6_multipath_flush(struct fib6_info *rt)
4812 {
4813 struct fib6_info *iter;
4814
4815 rt->should_flush = 1;
4816 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4817 iter->should_flush = 1;
4818 }
4819
4820 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
4821 const struct net_device *down_dev)
4822 {
4823 struct fib6_info *iter;
4824 unsigned int dead = 0;
4825
4826 if (rt->fib6_nh->fib_nh_dev == down_dev ||
4827 rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4828 dead++;
4829 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4830 if (iter->fib6_nh->fib_nh_dev == down_dev ||
4831 iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4832 dead++;
4833
4834 return dead;
4835 }
4836
4837 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
4838 const struct net_device *dev,
4839 unsigned char nh_flags)
4840 {
4841 struct fib6_info *iter;
4842
4843 if (rt->fib6_nh->fib_nh_dev == dev)
4844 rt->fib6_nh->fib_nh_flags |= nh_flags;
4845 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4846 if (iter->fib6_nh->fib_nh_dev == dev)
4847 iter->fib6_nh->fib_nh_flags |= nh_flags;
4848 }
4849
4850 /* called with write lock held for table with rt */
4851 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
4852 {
4853 const struct arg_netdev_event *arg = p_arg;
4854 const struct net_device *dev = arg->dev;
4855 struct net *net = dev_net(dev);
4856
4857 if (rt == net->ipv6.fib6_null_entry || rt->nh)
4858 return 0;
4859
4860 switch (arg->event) {
4861 case NETDEV_UNREGISTER:
4862 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4863 case NETDEV_DOWN:
4864 if (rt->should_flush)
4865 return -1;
4866 if (!rt->fib6_nsiblings)
4867 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4868 if (rt6_multipath_uses_dev(rt, dev)) {
4869 unsigned int count;
4870
4871 count = rt6_multipath_dead_count(rt, dev);
4872 if (rt->fib6_nsiblings + 1 == count) {
4873 rt6_multipath_flush(rt);
4874 return -1;
4875 }
4876 rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4877 RTNH_F_LINKDOWN);
4878 fib6_update_sernum(net, rt);
4879 rt6_multipath_rebalance(rt);
4880 }
4881 return -2;
4882 case NETDEV_CHANGE:
4883 if (rt->fib6_nh->fib_nh_dev != dev ||
4884 rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4885 break;
4886 rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
4887 rt6_multipath_rebalance(rt);
4888 break;
4889 }
4890
4891 return 0;
4892 }
4893
4894 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4895 {
4896 struct arg_netdev_event arg = {
4897 .dev = dev,
4898 {
4899 .event = event,
4900 },
4901 };
4902 struct net *net = dev_net(dev);
4903
4904 if (net->ipv6.sysctl.skip_notify_on_dev_down)
4905 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4906 else
4907 fib6_clean_all(net, fib6_ifdown, &arg);
4908 }
4909
4910 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4911 {
4912 rt6_sync_down_dev(dev, event);
4913 rt6_uncached_list_flush_dev(dev_net(dev), dev);
4914 neigh_ifdown(&nd_tbl, dev);
4915 }
4916
4917 struct rt6_mtu_change_arg {
4918 struct net_device *dev;
4919 unsigned int mtu;
4920 struct fib6_info *f6i;
4921 };
4922
4923 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
4924 {
4925 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
4926 struct fib6_info *f6i = arg->f6i;
4927
4928 /* For administrative MTU increase, there is no way to discover
4929 * IPv6 PMTU increase, so PMTU increase should be updated here.
4930 * Since RFC 1981 doesn't include administrative MTU increase
4931 * update PMTU increase is a MUST. (i.e. jumbo frame)
4932 */
4933 if (nh->fib_nh_dev == arg->dev) {
4934 struct inet6_dev *idev = __in6_dev_get(arg->dev);
4935 u32 mtu = f6i->fib6_pmtu;
4936
4937 if (mtu >= arg->mtu ||
4938 (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4939 fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
4940
4941 spin_lock_bh(&rt6_exception_lock);
4942 rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
4943 spin_unlock_bh(&rt6_exception_lock);
4944 }
4945
4946 return 0;
4947 }
4948
4949 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
4950 {
4951 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4952 struct inet6_dev *idev;
4953
4954 /* In IPv6 pmtu discovery is not optional,
4955 so that RTAX_MTU lock cannot disable it.
4956 We still use this lock to block changes
4957 caused by addrconf/ndisc.
4958 */
4959
4960 idev = __in6_dev_get(arg->dev);
4961 if (!idev)
4962 return 0;
4963
4964 if (fib6_metric_locked(f6i, RTAX_MTU))
4965 return 0;
4966
4967 arg->f6i = f6i;
4968 if (f6i->nh) {
4969 /* fib6_nh_mtu_change only returns 0, so this is safe */
4970 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
4971 arg);
4972 }
4973
4974 return fib6_nh_mtu_change(f6i->fib6_nh, arg);
4975 }
4976
4977 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4978 {
4979 struct rt6_mtu_change_arg arg = {
4980 .dev = dev,
4981 .mtu = mtu,
4982 };
4983
4984 fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4985 }
4986
4987 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4988 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 },
4989 [RTA_GATEWAY] = { .len = sizeof(struct in6_addr) },
4990 [RTA_PREFSRC] = { .len = sizeof(struct in6_addr) },
4991 [RTA_OIF] = { .type = NLA_U32 },
4992 [RTA_IIF] = { .type = NLA_U32 },
4993 [RTA_PRIORITY] = { .type = NLA_U32 },
4994 [RTA_METRICS] = { .type = NLA_NESTED },
4995 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
4996 [RTA_PREF] = { .type = NLA_U8 },
4997 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
4998 [RTA_ENCAP] = { .type = NLA_NESTED },
4999 [RTA_EXPIRES] = { .type = NLA_U32 },
5000 [RTA_UID] = { .type = NLA_U32 },
5001 [RTA_MARK] = { .type = NLA_U32 },
5002 [RTA_TABLE] = { .type = NLA_U32 },
5003 [RTA_IP_PROTO] = { .type = NLA_U8 },
5004 [RTA_SPORT] = { .type = NLA_U16 },
5005 [RTA_DPORT] = { .type = NLA_U16 },
5006 [RTA_NH_ID] = { .type = NLA_U32 },
5007 };
5008
5009 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
5010 struct fib6_config *cfg,
5011 struct netlink_ext_ack *extack)
5012 {
5013 struct rtmsg *rtm;
5014 struct nlattr *tb[RTA_MAX+1];
5015 unsigned int pref;
5016 int err;
5017
5018 err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5019 rtm_ipv6_policy, extack);
5020 if (err < 0)
5021 goto errout;
5022
5023 err = -EINVAL;
5024 rtm = nlmsg_data(nlh);
5025
5026 *cfg = (struct fib6_config){
5027 .fc_table = rtm->rtm_table,
5028 .fc_dst_len = rtm->rtm_dst_len,
5029 .fc_src_len = rtm->rtm_src_len,
5030 .fc_flags = RTF_UP,
5031 .fc_protocol = rtm->rtm_protocol,
5032 .fc_type = rtm->rtm_type,
5033
5034 .fc_nlinfo.portid = NETLINK_CB(skb).portid,
5035 .fc_nlinfo.nlh = nlh,
5036 .fc_nlinfo.nl_net = sock_net(skb->sk),
5037 };
5038
5039 if (rtm->rtm_type == RTN_UNREACHABLE ||
5040 rtm->rtm_type == RTN_BLACKHOLE ||
5041 rtm->rtm_type == RTN_PROHIBIT ||
5042 rtm->rtm_type == RTN_THROW)
5043 cfg->fc_flags |= RTF_REJECT;
5044
5045 if (rtm->rtm_type == RTN_LOCAL)
5046 cfg->fc_flags |= RTF_LOCAL;
5047
5048 if (rtm->rtm_flags & RTM_F_CLONED)
5049 cfg->fc_flags |= RTF_CACHE;
5050
5051 cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
5052
5053 if (tb[RTA_NH_ID]) {
5054 if (tb[RTA_GATEWAY] || tb[RTA_OIF] ||
5055 tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
5056 NL_SET_ERR_MSG(extack,
5057 "Nexthop specification and nexthop id are mutually exclusive");
5058 goto errout;
5059 }
5060 cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
5061 }
5062
5063 if (tb[RTA_GATEWAY]) {
5064 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
5065 cfg->fc_flags |= RTF_GATEWAY;
5066 }
5067 if (tb[RTA_VIA]) {
5068 NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
5069 goto errout;
5070 }
5071
5072 if (tb[RTA_DST]) {
5073 int plen = (rtm->rtm_dst_len + 7) >> 3;
5074
5075 if (nla_len(tb[RTA_DST]) < plen)
5076 goto errout;
5077
5078 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
5079 }
5080
5081 if (tb[RTA_SRC]) {
5082 int plen = (rtm->rtm_src_len + 7) >> 3;
5083
5084 if (nla_len(tb[RTA_SRC]) < plen)
5085 goto errout;
5086
5087 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
5088 }
5089
5090 if (tb[RTA_PREFSRC])
5091 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
5092
5093 if (tb[RTA_OIF])
5094 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
5095
5096 if (tb[RTA_PRIORITY])
5097 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
5098
5099 if (tb[RTA_METRICS]) {
5100 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
5101 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
5102 }
5103
5104 if (tb[RTA_TABLE])
5105 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
5106
5107 if (tb[RTA_MULTIPATH]) {
5108 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
5109 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
5110
5111 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
5112 cfg->fc_mp_len, extack);
5113 if (err < 0)
5114 goto errout;
5115 }
5116
5117 if (tb[RTA_PREF]) {
5118 pref = nla_get_u8(tb[RTA_PREF]);
5119 if (pref != ICMPV6_ROUTER_PREF_LOW &&
5120 pref != ICMPV6_ROUTER_PREF_HIGH)
5121 pref = ICMPV6_ROUTER_PREF_MEDIUM;
5122 cfg->fc_flags |= RTF_PREF(pref);
5123 }
5124
5125 if (tb[RTA_ENCAP])
5126 cfg->fc_encap = tb[RTA_ENCAP];
5127
5128 if (tb[RTA_ENCAP_TYPE]) {
5129 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
5130
5131 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
5132 if (err < 0)
5133 goto errout;
5134 }
5135
5136 if (tb[RTA_EXPIRES]) {
5137 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
5138
5139 if (addrconf_finite_timeout(timeout)) {
5140 cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
5141 cfg->fc_flags |= RTF_EXPIRES;
5142 }
5143 }
5144
5145 err = 0;
5146 errout:
5147 return err;
5148 }
5149
5150 struct rt6_nh {
5151 struct fib6_info *fib6_info;
5152 struct fib6_config r_cfg;
5153 struct list_head next;
5154 };
5155
5156 static int ip6_route_info_append(struct net *net,
5157 struct list_head *rt6_nh_list,
5158 struct fib6_info *rt,
5159 struct fib6_config *r_cfg)
5160 {
5161 struct rt6_nh *nh;
5162 int err = -EEXIST;
5163
5164 list_for_each_entry(nh, rt6_nh_list, next) {
5165 /* check if fib6_info already exists */
5166 if (rt6_duplicate_nexthop(nh->fib6_info, rt))
5167 return err;
5168 }
5169
5170 nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5171 if (!nh)
5172 return -ENOMEM;
5173 nh->fib6_info = rt;
5174 memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
5175 list_add_tail(&nh->next, rt6_nh_list);
5176
5177 return 0;
5178 }
5179
5180 static void ip6_route_mpath_notify(struct fib6_info *rt,
5181 struct fib6_info *rt_last,
5182 struct nl_info *info,
5183 __u16 nlflags)
5184 {
5185 /* if this is an APPEND route, then rt points to the first route
5186 * inserted and rt_last points to last route inserted. Userspace
5187 * wants a consistent dump of the route which starts at the first
5188 * nexthop. Since sibling routes are always added at the end of
5189 * the list, find the first sibling of the last route appended
5190 */
5191 if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
5192 rt = list_first_entry(&rt_last->fib6_siblings,
5193 struct fib6_info,
5194 fib6_siblings);
5195 }
5196
5197 if (rt)
5198 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
5199 }
5200
5201 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
5202 {
5203 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
5204 bool should_notify = false;
5205 struct fib6_info *leaf;
5206 struct fib6_node *fn;
5207
5208 rcu_read_lock();
5209 fn = rcu_dereference(rt->fib6_node);
5210 if (!fn)
5211 goto out;
5212
5213 leaf = rcu_dereference(fn->leaf);
5214 if (!leaf)
5215 goto out;
5216
5217 if (rt == leaf ||
5218 (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
5219 rt6_qualify_for_ecmp(leaf)))
5220 should_notify = true;
5221 out:
5222 rcu_read_unlock();
5223
5224 return should_notify;
5225 }
5226
5227 static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla,
5228 struct netlink_ext_ack *extack)
5229 {
5230 if (nla_len(nla) < sizeof(*gw)) {
5231 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY");
5232 return -EINVAL;
5233 }
5234
5235 *gw = nla_get_in6_addr(nla);
5236
5237 return 0;
5238 }
5239
5240 static int ip6_route_multipath_add(struct fib6_config *cfg,
5241 struct netlink_ext_ack *extack)
5242 {
5243 struct fib6_info *rt_notif = NULL, *rt_last = NULL;
5244 struct nl_info *info = &cfg->fc_nlinfo;
5245 struct fib6_config r_cfg;
5246 struct rtnexthop *rtnh;
5247 struct fib6_info *rt;
5248 struct rt6_nh *err_nh;
5249 struct rt6_nh *nh, *nh_safe;
5250 __u16 nlflags;
5251 int remaining;
5252 int attrlen;
5253 int err = 1;
5254 int nhn = 0;
5255 int replace = (cfg->fc_nlinfo.nlh &&
5256 (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5257 LIST_HEAD(rt6_nh_list);
5258
5259 nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
5260 if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
5261 nlflags |= NLM_F_APPEND;
5262
5263 remaining = cfg->fc_mp_len;
5264 rtnh = (struct rtnexthop *)cfg->fc_mp;
5265
5266 /* Parse a Multipath Entry and build a list (rt6_nh_list) of
5267 * fib6_info structs per nexthop
5268 */
5269 while (rtnh_ok(rtnh, remaining)) {
5270 memcpy(&r_cfg, cfg, sizeof(*cfg));
5271 if (rtnh->rtnh_ifindex)
5272 r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5273
5274 attrlen = rtnh_attrlen(rtnh);
5275 if (attrlen > 0) {
5276 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5277
5278 nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5279 if (nla) {
5280 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5281 extack);
5282 if (err)
5283 goto cleanup;
5284
5285 r_cfg.fc_flags |= RTF_GATEWAY;
5286 }
5287 r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5288
5289 /* RTA_ENCAP_TYPE length checked in
5290 * lwtunnel_valid_encap_type_attr
5291 */
5292 nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5293 if (nla)
5294 r_cfg.fc_encap_type = nla_get_u16(nla);
5295 }
5296
5297 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5298 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5299 if (IS_ERR(rt)) {
5300 err = PTR_ERR(rt);
5301 rt = NULL;
5302 goto cleanup;
5303 }
5304 if (!rt6_qualify_for_ecmp(rt)) {
5305 err = -EINVAL;
5306 NL_SET_ERR_MSG(extack,
5307 "Device only routes can not be added for IPv6 using the multipath API.");
5308 fib6_info_release(rt);
5309 goto cleanup;
5310 }
5311
5312 rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
5313
5314 err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
5315 rt, &r_cfg);
5316 if (err) {
5317 fib6_info_release(rt);
5318 goto cleanup;
5319 }
5320
5321 rtnh = rtnh_next(rtnh, &remaining);
5322 }
5323
5324 if (list_empty(&rt6_nh_list)) {
5325 NL_SET_ERR_MSG(extack,
5326 "Invalid nexthop configuration - no valid nexthops");
5327 return -EINVAL;
5328 }
5329
5330 /* for add and replace send one notification with all nexthops.
5331 * Skip the notification in fib6_add_rt2node and send one with
5332 * the full route when done
5333 */
5334 info->skip_notify = 1;
5335
5336 /* For add and replace, send one notification with all nexthops. For
5337 * append, send one notification with all appended nexthops.
5338 */
5339 info->skip_notify_kernel = 1;
5340
5341 err_nh = NULL;
5342 list_for_each_entry(nh, &rt6_nh_list, next) {
5343 err = __ip6_ins_rt(nh->fib6_info, info, extack);
5344 fib6_info_release(nh->fib6_info);
5345
5346 if (!err) {
5347 /* save reference to last route successfully inserted */
5348 rt_last = nh->fib6_info;
5349
5350 /* save reference to first route for notification */
5351 if (!rt_notif)
5352 rt_notif = nh->fib6_info;
5353 }
5354
5355 /* nh->fib6_info is used or freed at this point, reset to NULL*/
5356 nh->fib6_info = NULL;
5357 if (err) {
5358 if (replace && nhn)
5359 NL_SET_ERR_MSG_MOD(extack,
5360 "multipath route replace failed (check consistency of installed routes)");
5361 err_nh = nh;
5362 goto add_errout;
5363 }
5364
5365 /* Because each route is added like a single route we remove
5366 * these flags after the first nexthop: if there is a collision,
5367 * we have already failed to add the first nexthop:
5368 * fib6_add_rt2node() has rejected it; when replacing, old
5369 * nexthops have been replaced by first new, the rest should
5370 * be added to it.
5371 */
5372 if (cfg->fc_nlinfo.nlh) {
5373 cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
5374 NLM_F_REPLACE);
5375 cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
5376 }
5377 nhn++;
5378 }
5379
5380 /* An in-kernel notification should only be sent in case the new
5381 * multipath route is added as the first route in the node, or if
5382 * it was appended to it. We pass 'rt_notif' since it is the first
5383 * sibling and might allow us to skip some checks in the replace case.
5384 */
5385 if (ip6_route_mpath_should_notify(rt_notif)) {
5386 enum fib_event_type fib_event;
5387
5388 if (rt_notif->fib6_nsiblings != nhn - 1)
5389 fib_event = FIB_EVENT_ENTRY_APPEND;
5390 else
5391 fib_event = FIB_EVENT_ENTRY_REPLACE;
5392
5393 err = call_fib6_multipath_entry_notifiers(info->nl_net,
5394 fib_event, rt_notif,
5395 nhn - 1, extack);
5396 if (err) {
5397 /* Delete all the siblings that were just added */
5398 err_nh = NULL;
5399 goto add_errout;
5400 }
5401 }
5402
5403 /* success ... tell user about new route */
5404 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5405 goto cleanup;
5406
5407 add_errout:
5408 /* send notification for routes that were added so that
5409 * the delete notifications sent by ip6_route_del are
5410 * coherent
5411 */
5412 if (rt_notif)
5413 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5414
5415 /* Delete routes that were already added */
5416 list_for_each_entry(nh, &rt6_nh_list, next) {
5417 if (err_nh == nh)
5418 break;
5419 ip6_route_del(&nh->r_cfg, extack);
5420 }
5421
5422 cleanup:
5423 list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
5424 if (nh->fib6_info)
5425 fib6_info_release(nh->fib6_info);
5426 list_del(&nh->next);
5427 kfree(nh);
5428 }
5429
5430 return err;
5431 }
5432
5433 static int ip6_route_multipath_del(struct fib6_config *cfg,
5434 struct netlink_ext_ack *extack)
5435 {
5436 struct fib6_config r_cfg;
5437 struct rtnexthop *rtnh;
5438 int last_err = 0;
5439 int remaining;
5440 int attrlen;
5441 int err;
5442
5443 remaining = cfg->fc_mp_len;
5444 rtnh = (struct rtnexthop *)cfg->fc_mp;
5445
5446 /* Parse a Multipath Entry */
5447 while (rtnh_ok(rtnh, remaining)) {
5448 memcpy(&r_cfg, cfg, sizeof(*cfg));
5449 if (rtnh->rtnh_ifindex)
5450 r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5451
5452 attrlen = rtnh_attrlen(rtnh);
5453 if (attrlen > 0) {
5454 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5455
5456 nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5457 if (nla) {
5458 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5459 extack);
5460 if (err) {
5461 last_err = err;
5462 goto next_rtnh;
5463 }
5464
5465 r_cfg.fc_flags |= RTF_GATEWAY;
5466 }
5467 }
5468 err = ip6_route_del(&r_cfg, extack);
5469 if (err)
5470 last_err = err;
5471
5472 next_rtnh:
5473 rtnh = rtnh_next(rtnh, &remaining);
5474 }
5475
5476 return last_err;
5477 }
5478
5479 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5480 struct netlink_ext_ack *extack)
5481 {
5482 struct fib6_config cfg;
5483 int err;
5484
5485 err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5486 if (err < 0)
5487 return err;
5488
5489 if (cfg.fc_nh_id &&
5490 !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
5491 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
5492 return -EINVAL;
5493 }
5494
5495 if (cfg.fc_mp)
5496 return ip6_route_multipath_del(&cfg, extack);
5497 else {
5498 cfg.fc_delete_all_nh = 1;
5499 return ip6_route_del(&cfg, extack);
5500 }
5501 }
5502
5503 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5504 struct netlink_ext_ack *extack)
5505 {
5506 struct fib6_config cfg;
5507 int err;
5508
5509 err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5510 if (err < 0)
5511 return err;
5512
5513 if (cfg.fc_metric == 0)
5514 cfg.fc_metric = IP6_RT_PRIO_USER;
5515
5516 if (cfg.fc_mp)
5517 return ip6_route_multipath_add(&cfg, extack);
5518 else
5519 return ip6_route_add(&cfg, GFP_KERNEL, extack);
5520 }
5521
5522 /* add the overhead of this fib6_nh to nexthop_len */
5523 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
5524 {
5525 int *nexthop_len = arg;
5526
5527 *nexthop_len += nla_total_size(0) /* RTA_MULTIPATH */
5528 + NLA_ALIGN(sizeof(struct rtnexthop))
5529 + nla_total_size(16); /* RTA_GATEWAY */
5530
5531 if (nh->fib_nh_lws) {
5532 /* RTA_ENCAP_TYPE */
5533 *nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5534 /* RTA_ENCAP */
5535 *nexthop_len += nla_total_size(2);
5536 }
5537
5538 return 0;
5539 }
5540
5541 static size_t rt6_nlmsg_size(struct fib6_info *f6i)
5542 {
5543 int nexthop_len;
5544
5545 if (f6i->nh) {
5546 nexthop_len = nla_total_size(4); /* RTA_NH_ID */
5547 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
5548 &nexthop_len);
5549 } else {
5550 struct fib6_nh *nh = f6i->fib6_nh;
5551
5552 nexthop_len = 0;
5553 if (f6i->fib6_nsiblings) {
5554 nexthop_len = nla_total_size(0) /* RTA_MULTIPATH */
5555 + NLA_ALIGN(sizeof(struct rtnexthop))
5556 + nla_total_size(16) /* RTA_GATEWAY */
5557 + lwtunnel_get_encap_size(nh->fib_nh_lws);
5558
5559 nexthop_len *= f6i->fib6_nsiblings;
5560 }
5561 nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5562 }
5563
5564 return NLMSG_ALIGN(sizeof(struct rtmsg))
5565 + nla_total_size(16) /* RTA_SRC */
5566 + nla_total_size(16) /* RTA_DST */
5567 + nla_total_size(16) /* RTA_GATEWAY */
5568 + nla_total_size(16) /* RTA_PREFSRC */
5569 + nla_total_size(4) /* RTA_TABLE */
5570 + nla_total_size(4) /* RTA_IIF */
5571 + nla_total_size(4) /* RTA_OIF */
5572 + nla_total_size(4) /* RTA_PRIORITY */
5573 + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
5574 + nla_total_size(sizeof(struct rta_cacheinfo))
5575 + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
5576 + nla_total_size(1) /* RTA_PREF */
5577 + nexthop_len;
5578 }
5579
5580 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
5581 unsigned char *flags)
5582 {
5583 if (nexthop_is_multipath(nh)) {
5584 struct nlattr *mp;
5585
5586 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5587 if (!mp)
5588 goto nla_put_failure;
5589
5590 if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
5591 goto nla_put_failure;
5592
5593 nla_nest_end(skb, mp);
5594 } else {
5595 struct fib6_nh *fib6_nh;
5596
5597 fib6_nh = nexthop_fib6_nh(nh);
5598 if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
5599 flags, false) < 0)
5600 goto nla_put_failure;
5601 }
5602
5603 return 0;
5604
5605 nla_put_failure:
5606 return -EMSGSIZE;
5607 }
5608
5609 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
5610 struct fib6_info *rt, struct dst_entry *dst,
5611 struct in6_addr *dest, struct in6_addr *src,
5612 int iif, int type, u32 portid, u32 seq,
5613 unsigned int flags)
5614 {
5615 struct rt6_info *rt6 = (struct rt6_info *)dst;
5616 struct rt6key *rt6_dst, *rt6_src;
5617 u32 *pmetrics, table, rt6_flags;
5618 unsigned char nh_flags = 0;
5619 struct nlmsghdr *nlh;
5620 struct rtmsg *rtm;
5621 long expires = 0;
5622
5623 nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
5624 if (!nlh)
5625 return -EMSGSIZE;
5626
5627 if (rt6) {
5628 rt6_dst = &rt6->rt6i_dst;
5629 rt6_src = &rt6->rt6i_src;
5630 rt6_flags = rt6->rt6i_flags;
5631 } else {
5632 rt6_dst = &rt->fib6_dst;
5633 rt6_src = &rt->fib6_src;
5634 rt6_flags = rt->fib6_flags;
5635 }
5636
5637 rtm = nlmsg_data(nlh);
5638 rtm->rtm_family = AF_INET6;
5639 rtm->rtm_dst_len = rt6_dst->plen;
5640 rtm->rtm_src_len = rt6_src->plen;
5641 rtm->rtm_tos = 0;
5642 if (rt->fib6_table)
5643 table = rt->fib6_table->tb6_id;
5644 else
5645 table = RT6_TABLE_UNSPEC;
5646 rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
5647 if (nla_put_u32(skb, RTA_TABLE, table))
5648 goto nla_put_failure;
5649
5650 rtm->rtm_type = rt->fib6_type;
5651 rtm->rtm_flags = 0;
5652 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
5653 rtm->rtm_protocol = rt->fib6_protocol;
5654
5655 if (rt6_flags & RTF_CACHE)
5656 rtm->rtm_flags |= RTM_F_CLONED;
5657
5658 if (dest) {
5659 if (nla_put_in6_addr(skb, RTA_DST, dest))
5660 goto nla_put_failure;
5661 rtm->rtm_dst_len = 128;
5662 } else if (rtm->rtm_dst_len)
5663 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
5664 goto nla_put_failure;
5665 #ifdef CONFIG_IPV6_SUBTREES
5666 if (src) {
5667 if (nla_put_in6_addr(skb, RTA_SRC, src))
5668 goto nla_put_failure;
5669 rtm->rtm_src_len = 128;
5670 } else if (rtm->rtm_src_len &&
5671 nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
5672 goto nla_put_failure;
5673 #endif
5674 if (iif) {
5675 #ifdef CONFIG_IPV6_MROUTE
5676 if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
5677 int err = ip6mr_get_route(net, skb, rtm, portid);
5678
5679 if (err == 0)
5680 return 0;
5681 if (err < 0)
5682 goto nla_put_failure;
5683 } else
5684 #endif
5685 if (nla_put_u32(skb, RTA_IIF, iif))
5686 goto nla_put_failure;
5687 } else if (dest) {
5688 struct in6_addr saddr_buf;
5689 if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
5690 nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5691 goto nla_put_failure;
5692 }
5693
5694 if (rt->fib6_prefsrc.plen) {
5695 struct in6_addr saddr_buf;
5696 saddr_buf = rt->fib6_prefsrc.addr;
5697 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5698 goto nla_put_failure;
5699 }
5700
5701 pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
5702 if (rtnetlink_put_metrics(skb, pmetrics) < 0)
5703 goto nla_put_failure;
5704
5705 if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
5706 goto nla_put_failure;
5707
5708 /* For multipath routes, walk the siblings list and add
5709 * each as a nexthop within RTA_MULTIPATH.
5710 */
5711 if (rt6) {
5712 if (rt6_flags & RTF_GATEWAY &&
5713 nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
5714 goto nla_put_failure;
5715
5716 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
5717 goto nla_put_failure;
5718
5719 if (dst->lwtstate &&
5720 lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
5721 goto nla_put_failure;
5722 } else if (rt->fib6_nsiblings) {
5723 struct fib6_info *sibling, *next_sibling;
5724 struct nlattr *mp;
5725
5726 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5727 if (!mp)
5728 goto nla_put_failure;
5729
5730 if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
5731 rt->fib6_nh->fib_nh_weight, AF_INET6,
5732 0) < 0)
5733 goto nla_put_failure;
5734
5735 list_for_each_entry_safe(sibling, next_sibling,
5736 &rt->fib6_siblings, fib6_siblings) {
5737 if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
5738 sibling->fib6_nh->fib_nh_weight,
5739 AF_INET6, 0) < 0)
5740 goto nla_put_failure;
5741 }
5742
5743 nla_nest_end(skb, mp);
5744 } else if (rt->nh) {
5745 if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
5746 goto nla_put_failure;
5747
5748 if (nexthop_is_blackhole(rt->nh))
5749 rtm->rtm_type = RTN_BLACKHOLE;
5750
5751 if (net->ipv4.sysctl_nexthop_compat_mode &&
5752 rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
5753 goto nla_put_failure;
5754
5755 rtm->rtm_flags |= nh_flags;
5756 } else {
5757 if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
5758 &nh_flags, false) < 0)
5759 goto nla_put_failure;
5760
5761 rtm->rtm_flags |= nh_flags;
5762 }
5763
5764 if (rt6_flags & RTF_EXPIRES) {
5765 expires = dst ? dst->expires : rt->expires;
5766 expires -= jiffies;
5767 }
5768
5769 if (!dst) {
5770 if (rt->offload)
5771 rtm->rtm_flags |= RTM_F_OFFLOAD;
5772 if (rt->trap)
5773 rtm->rtm_flags |= RTM_F_TRAP;
5774 if (rt->offload_failed)
5775 rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
5776 }
5777
5778 if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
5779 goto nla_put_failure;
5780
5781 if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
5782 goto nla_put_failure;
5783
5784
5785 nlmsg_end(skb, nlh);
5786 return 0;
5787
5788 nla_put_failure:
5789 nlmsg_cancel(skb, nlh);
5790 return -EMSGSIZE;
5791 }
5792
5793 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
5794 {
5795 const struct net_device *dev = arg;
5796
5797 if (nh->fib_nh_dev == dev)
5798 return 1;
5799
5800 return 0;
5801 }
5802
5803 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
5804 const struct net_device *dev)
5805 {
5806 if (f6i->nh) {
5807 struct net_device *_dev = (struct net_device *)dev;
5808
5809 return !!nexthop_for_each_fib6_nh(f6i->nh,
5810 fib6_info_nh_uses_dev,
5811 _dev);
5812 }
5813
5814 if (f6i->fib6_nh->fib_nh_dev == dev)
5815 return true;
5816
5817 if (f6i->fib6_nsiblings) {
5818 struct fib6_info *sibling, *next_sibling;
5819
5820 list_for_each_entry_safe(sibling, next_sibling,
5821 &f6i->fib6_siblings, fib6_siblings) {
5822 if (sibling->fib6_nh->fib_nh_dev == dev)
5823 return true;
5824 }
5825 }
5826
5827 return false;
5828 }
5829
5830 struct fib6_nh_exception_dump_walker {
5831 struct rt6_rtnl_dump_arg *dump;
5832 struct fib6_info *rt;
5833 unsigned int flags;
5834 unsigned int skip;
5835 unsigned int count;
5836 };
5837
5838 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
5839 {
5840 struct fib6_nh_exception_dump_walker *w = arg;
5841 struct rt6_rtnl_dump_arg *dump = w->dump;
5842 struct rt6_exception_bucket *bucket;
5843 struct rt6_exception *rt6_ex;
5844 int i, err;
5845
5846 bucket = fib6_nh_get_excptn_bucket(nh, NULL);
5847 if (!bucket)
5848 return 0;
5849
5850 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
5851 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
5852 if (w->skip) {
5853 w->skip--;
5854 continue;
5855 }
5856
5857 /* Expiration of entries doesn't bump sernum, insertion
5858 * does. Removal is triggered by insertion, so we can
5859 * rely on the fact that if entries change between two
5860 * partial dumps, this node is scanned again completely,
5861 * see rt6_insert_exception() and fib6_dump_table().
5862 *
5863 * Count expired entries we go through as handled
5864 * entries that we'll skip next time, in case of partial
5865 * node dump. Otherwise, if entries expire meanwhile,
5866 * we'll skip the wrong amount.
5867 */
5868 if (rt6_check_expired(rt6_ex->rt6i)) {
5869 w->count++;
5870 continue;
5871 }
5872
5873 err = rt6_fill_node(dump->net, dump->skb, w->rt,
5874 &rt6_ex->rt6i->dst, NULL, NULL, 0,
5875 RTM_NEWROUTE,
5876 NETLINK_CB(dump->cb->skb).portid,
5877 dump->cb->nlh->nlmsg_seq, w->flags);
5878 if (err)
5879 return err;
5880
5881 w->count++;
5882 }
5883 bucket++;
5884 }
5885
5886 return 0;
5887 }
5888
5889 /* Return -1 if done with node, number of handled routes on partial dump */
5890 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
5891 {
5892 struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
5893 struct fib_dump_filter *filter = &arg->filter;
5894 unsigned int flags = NLM_F_MULTI;
5895 struct net *net = arg->net;
5896 int count = 0;
5897
5898 if (rt == net->ipv6.fib6_null_entry)
5899 return -1;
5900
5901 if ((filter->flags & RTM_F_PREFIX) &&
5902 !(rt->fib6_flags & RTF_PREFIX_RT)) {
5903 /* success since this is not a prefix route */
5904 return -1;
5905 }
5906 if (filter->filter_set &&
5907 ((filter->rt_type && rt->fib6_type != filter->rt_type) ||
5908 (filter->dev && !fib6_info_uses_dev(rt, filter->dev)) ||
5909 (filter->protocol && rt->fib6_protocol != filter->protocol))) {
5910 return -1;
5911 }
5912
5913 if (filter->filter_set ||
5914 !filter->dump_routes || !filter->dump_exceptions) {
5915 flags |= NLM_F_DUMP_FILTERED;
5916 }
5917
5918 if (filter->dump_routes) {
5919 if (skip) {
5920 skip--;
5921 } else {
5922 if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
5923 0, RTM_NEWROUTE,
5924 NETLINK_CB(arg->cb->skb).portid,
5925 arg->cb->nlh->nlmsg_seq, flags)) {
5926 return 0;
5927 }
5928 count++;
5929 }
5930 }
5931
5932 if (filter->dump_exceptions) {
5933 struct fib6_nh_exception_dump_walker w = { .dump = arg,
5934 .rt = rt,
5935 .flags = flags,
5936 .skip = skip,
5937 .count = 0 };
5938 int err;
5939
5940 rcu_read_lock();
5941 if (rt->nh) {
5942 err = nexthop_for_each_fib6_nh(rt->nh,
5943 rt6_nh_dump_exceptions,
5944 &w);
5945 } else {
5946 err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
5947 }
5948 rcu_read_unlock();
5949
5950 if (err)
5951 return count += w.count;
5952 }
5953
5954 return -1;
5955 }
5956
5957 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
5958 const struct nlmsghdr *nlh,
5959 struct nlattr **tb,
5960 struct netlink_ext_ack *extack)
5961 {
5962 struct rtmsg *rtm;
5963 int i, err;
5964
5965 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
5966 NL_SET_ERR_MSG_MOD(extack,
5967 "Invalid header for get route request");
5968 return -EINVAL;
5969 }
5970
5971 if (!netlink_strict_get_check(skb))
5972 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5973 rtm_ipv6_policy, extack);
5974
5975 rtm = nlmsg_data(nlh);
5976 if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
5977 (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
5978 rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
5979 rtm->rtm_type) {
5980 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
5981 return -EINVAL;
5982 }
5983 if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
5984 NL_SET_ERR_MSG_MOD(extack,
5985 "Invalid flags for get route request");
5986 return -EINVAL;
5987 }
5988
5989 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
5990 rtm_ipv6_policy, extack);
5991 if (err)
5992 return err;
5993
5994 if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
5995 (tb[RTA_DST] && !rtm->rtm_dst_len)) {
5996 NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
5997 return -EINVAL;
5998 }
5999
6000 for (i = 0; i <= RTA_MAX; i++) {
6001 if (!tb[i])
6002 continue;
6003
6004 switch (i) {
6005 case RTA_SRC:
6006 case RTA_DST:
6007 case RTA_IIF:
6008 case RTA_OIF:
6009 case RTA_MARK:
6010 case RTA_UID:
6011 case RTA_SPORT:
6012 case RTA_DPORT:
6013 case RTA_IP_PROTO:
6014 break;
6015 default:
6016 NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
6017 return -EINVAL;
6018 }
6019 }
6020
6021 return 0;
6022 }
6023
6024 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
6025 struct netlink_ext_ack *extack)
6026 {
6027 struct net *net = sock_net(in_skb->sk);
6028 struct nlattr *tb[RTA_MAX+1];
6029 int err, iif = 0, oif = 0;
6030 struct fib6_info *from;
6031 struct dst_entry *dst;
6032 struct rt6_info *rt;
6033 struct sk_buff *skb;
6034 struct rtmsg *rtm;
6035 struct flowi6 fl6 = {};
6036 bool fibmatch;
6037
6038 err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
6039 if (err < 0)
6040 goto errout;
6041
6042 err = -EINVAL;
6043 rtm = nlmsg_data(nlh);
6044 fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
6045 fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
6046
6047 if (tb[RTA_SRC]) {
6048 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
6049 goto errout;
6050
6051 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
6052 }
6053
6054 if (tb[RTA_DST]) {
6055 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
6056 goto errout;
6057
6058 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
6059 }
6060
6061 if (tb[RTA_IIF])
6062 iif = nla_get_u32(tb[RTA_IIF]);
6063
6064 if (tb[RTA_OIF])
6065 oif = nla_get_u32(tb[RTA_OIF]);
6066
6067 if (tb[RTA_MARK])
6068 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
6069
6070 if (tb[RTA_UID])
6071 fl6.flowi6_uid = make_kuid(current_user_ns(),
6072 nla_get_u32(tb[RTA_UID]));
6073 else
6074 fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
6075
6076 if (tb[RTA_SPORT])
6077 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
6078
6079 if (tb[RTA_DPORT])
6080 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
6081
6082 if (tb[RTA_IP_PROTO]) {
6083 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
6084 &fl6.flowi6_proto, AF_INET6,
6085 extack);
6086 if (err)
6087 goto errout;
6088 }
6089
6090 if (iif) {
6091 struct net_device *dev;
6092 int flags = 0;
6093
6094 rcu_read_lock();
6095
6096 dev = dev_get_by_index_rcu(net, iif);
6097 if (!dev) {
6098 rcu_read_unlock();
6099 err = -ENODEV;
6100 goto errout;
6101 }
6102
6103 fl6.flowi6_iif = iif;
6104
6105 if (!ipv6_addr_any(&fl6.saddr))
6106 flags |= RT6_LOOKUP_F_HAS_SADDR;
6107
6108 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
6109
6110 rcu_read_unlock();
6111 } else {
6112 fl6.flowi6_oif = oif;
6113
6114 dst = ip6_route_output(net, NULL, &fl6);
6115 }
6116
6117
6118 rt = container_of(dst, struct rt6_info, dst);
6119 if (rt->dst.error) {
6120 err = rt->dst.error;
6121 ip6_rt_put(rt);
6122 goto errout;
6123 }
6124
6125 if (rt == net->ipv6.ip6_null_entry) {
6126 err = rt->dst.error;
6127 ip6_rt_put(rt);
6128 goto errout;
6129 }
6130
6131 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
6132 if (!skb) {
6133 ip6_rt_put(rt);
6134 err = -ENOBUFS;
6135 goto errout;
6136 }
6137
6138 skb_dst_set(skb, &rt->dst);
6139
6140 rcu_read_lock();
6141 from = rcu_dereference(rt->from);
6142 if (from) {
6143 if (fibmatch)
6144 err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
6145 iif, RTM_NEWROUTE,
6146 NETLINK_CB(in_skb).portid,
6147 nlh->nlmsg_seq, 0);
6148 else
6149 err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
6150 &fl6.saddr, iif, RTM_NEWROUTE,
6151 NETLINK_CB(in_skb).portid,
6152 nlh->nlmsg_seq, 0);
6153 } else {
6154 err = -ENETUNREACH;
6155 }
6156 rcu_read_unlock();
6157
6158 if (err < 0) {
6159 kfree_skb(skb);
6160 goto errout;
6161 }
6162
6163 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
6164 errout:
6165 return err;
6166 }
6167
6168 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
6169 unsigned int nlm_flags)
6170 {
6171 struct sk_buff *skb;
6172 struct net *net = info->nl_net;
6173 u32 seq;
6174 int err;
6175
6176 err = -ENOBUFS;
6177 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6178
6179 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6180 if (!skb)
6181 goto errout;
6182
6183 err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6184 event, info->portid, seq, nlm_flags);
6185 if (err < 0) {
6186 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6187 WARN_ON(err == -EMSGSIZE);
6188 kfree_skb(skb);
6189 goto errout;
6190 }
6191 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6192 info->nlh, gfp_any());
6193 return;
6194 errout:
6195 if (err < 0)
6196 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6197 }
6198
6199 void fib6_rt_update(struct net *net, struct fib6_info *rt,
6200 struct nl_info *info)
6201 {
6202 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6203 struct sk_buff *skb;
6204 int err = -ENOBUFS;
6205
6206 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6207 if (!skb)
6208 goto errout;
6209
6210 err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6211 RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
6212 if (err < 0) {
6213 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6214 WARN_ON(err == -EMSGSIZE);
6215 kfree_skb(skb);
6216 goto errout;
6217 }
6218 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6219 info->nlh, gfp_any());
6220 return;
6221 errout:
6222 if (err < 0)
6223 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6224 }
6225
6226 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
6227 bool offload, bool trap, bool offload_failed)
6228 {
6229 struct sk_buff *skb;
6230 int err;
6231
6232 if (f6i->offload == offload && f6i->trap == trap &&
6233 f6i->offload_failed == offload_failed)
6234 return;
6235
6236 f6i->offload = offload;
6237 f6i->trap = trap;
6238
6239 /* 2 means send notifications only if offload_failed was changed. */
6240 if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 &&
6241 f6i->offload_failed == offload_failed)
6242 return;
6243
6244 f6i->offload_failed = offload_failed;
6245
6246 if (!rcu_access_pointer(f6i->fib6_node))
6247 /* The route was removed from the tree, do not send
6248 * notification.
6249 */
6250 return;
6251
6252 if (!net->ipv6.sysctl.fib_notify_on_flag_change)
6253 return;
6254
6255 skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL);
6256 if (!skb) {
6257 err = -ENOBUFS;
6258 goto errout;
6259 }
6260
6261 err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0,
6262 0, 0);
6263 if (err < 0) {
6264 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6265 WARN_ON(err == -EMSGSIZE);
6266 kfree_skb(skb);
6267 goto errout;
6268 }
6269
6270 rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL);
6271 return;
6272
6273 errout:
6274 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6275 }
6276 EXPORT_SYMBOL(fib6_info_hw_flags_set);
6277
6278 static int ip6_route_dev_notify(struct notifier_block *this,
6279 unsigned long event, void *ptr)
6280 {
6281 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
6282 struct net *net = dev_net(dev);
6283
6284 if (!(dev->flags & IFF_LOOPBACK))
6285 return NOTIFY_OK;
6286
6287 if (event == NETDEV_REGISTER) {
6288 net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
6289 net->ipv6.ip6_null_entry->dst.dev = dev;
6290 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
6291 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6292 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
6293 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
6294 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
6295 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
6296 #endif
6297 } else if (event == NETDEV_UNREGISTER &&
6298 dev->reg_state != NETREG_UNREGISTERED) {
6299 /* NETDEV_UNREGISTER could be fired for multiple times by
6300 * netdev_wait_allrefs(). Make sure we only call this once.
6301 */
6302 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
6303 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6304 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
6305 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
6306 #endif
6307 }
6308
6309 return NOTIFY_OK;
6310 }
6311
6312 /*
6313 * /proc
6314 */
6315
6316 #ifdef CONFIG_PROC_FS
6317 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
6318 {
6319 struct net *net = (struct net *)seq->private;
6320 seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
6321 net->ipv6.rt6_stats->fib_nodes,
6322 net->ipv6.rt6_stats->fib_route_nodes,
6323 atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
6324 net->ipv6.rt6_stats->fib_rt_entries,
6325 net->ipv6.rt6_stats->fib_rt_cache,
6326 dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
6327 net->ipv6.rt6_stats->fib_discarded_routes);
6328
6329 return 0;
6330 }
6331 #endif /* CONFIG_PROC_FS */
6332
6333 #ifdef CONFIG_SYSCTL
6334
6335 static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
6336 void *buffer, size_t *lenp, loff_t *ppos)
6337 {
6338 struct net *net;
6339 int delay;
6340 int ret;
6341 if (!write)
6342 return -EINVAL;
6343
6344 net = (struct net *)ctl->extra1;
6345 delay = net->ipv6.sysctl.flush_delay;
6346 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
6347 if (ret)
6348 return ret;
6349
6350 fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
6351 return 0;
6352 }
6353
6354 static struct ctl_table ipv6_route_table_template[] = {
6355 {
6356 .procname = "flush",
6357 .data = &init_net.ipv6.sysctl.flush_delay,
6358 .maxlen = sizeof(int),
6359 .mode = 0200,
6360 .proc_handler = ipv6_sysctl_rtcache_flush
6361 },
6362 {
6363 .procname = "gc_thresh",
6364 .data = &ip6_dst_ops_template.gc_thresh,
6365 .maxlen = sizeof(int),
6366 .mode = 0644,
6367 .proc_handler = proc_dointvec,
6368 },
6369 {
6370 .procname = "max_size",
6371 .data = &init_net.ipv6.sysctl.ip6_rt_max_size,
6372 .maxlen = sizeof(int),
6373 .mode = 0644,
6374 .proc_handler = proc_dointvec,
6375 },
6376 {
6377 .procname = "gc_min_interval",
6378 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6379 .maxlen = sizeof(int),
6380 .mode = 0644,
6381 .proc_handler = proc_dointvec_jiffies,
6382 },
6383 {
6384 .procname = "gc_timeout",
6385 .data = &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
6386 .maxlen = sizeof(int),
6387 .mode = 0644,
6388 .proc_handler = proc_dointvec_jiffies,
6389 },
6390 {
6391 .procname = "gc_interval",
6392 .data = &init_net.ipv6.sysctl.ip6_rt_gc_interval,
6393 .maxlen = sizeof(int),
6394 .mode = 0644,
6395 .proc_handler = proc_dointvec_jiffies,
6396 },
6397 {
6398 .procname = "gc_elasticity",
6399 .data = &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
6400 .maxlen = sizeof(int),
6401 .mode = 0644,
6402 .proc_handler = proc_dointvec,
6403 },
6404 {
6405 .procname = "mtu_expires",
6406 .data = &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
6407 .maxlen = sizeof(int),
6408 .mode = 0644,
6409 .proc_handler = proc_dointvec_jiffies,
6410 },
6411 {
6412 .procname = "min_adv_mss",
6413 .data = &init_net.ipv6.sysctl.ip6_rt_min_advmss,
6414 .maxlen = sizeof(int),
6415 .mode = 0644,
6416 .proc_handler = proc_dointvec,
6417 },
6418 {
6419 .procname = "gc_min_interval_ms",
6420 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6421 .maxlen = sizeof(int),
6422 .mode = 0644,
6423 .proc_handler = proc_dointvec_ms_jiffies,
6424 },
6425 {
6426 .procname = "skip_notify_on_dev_down",
6427 .data = &init_net.ipv6.sysctl.skip_notify_on_dev_down,
6428 .maxlen = sizeof(int),
6429 .mode = 0644,
6430 .proc_handler = proc_dointvec_minmax,
6431 .extra1 = SYSCTL_ZERO,
6432 .extra2 = SYSCTL_ONE,
6433 },
6434 { }
6435 };
6436
6437 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
6438 {
6439 struct ctl_table *table;
6440
6441 table = kmemdup(ipv6_route_table_template,
6442 sizeof(ipv6_route_table_template),
6443 GFP_KERNEL);
6444
6445 if (table) {
6446 table[0].data = &net->ipv6.sysctl.flush_delay;
6447 table[0].extra1 = net;
6448 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
6449 table[2].data = &net->ipv6.sysctl.ip6_rt_max_size;
6450 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6451 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
6452 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
6453 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
6454 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
6455 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
6456 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6457 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
6458
6459 /* Don't export sysctls to unprivileged users */
6460 if (net->user_ns != &init_user_ns)
6461 table[0].procname = NULL;
6462 }
6463
6464 return table;
6465 }
6466 #endif
6467
6468 static int __net_init ip6_route_net_init(struct net *net)
6469 {
6470 int ret = -ENOMEM;
6471
6472 memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
6473 sizeof(net->ipv6.ip6_dst_ops));
6474
6475 if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
6476 goto out_ip6_dst_ops;
6477
6478 net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
6479 if (!net->ipv6.fib6_null_entry)
6480 goto out_ip6_dst_entries;
6481 memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
6482 sizeof(*net->ipv6.fib6_null_entry));
6483
6484 net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
6485 sizeof(*net->ipv6.ip6_null_entry),
6486 GFP_KERNEL);
6487 if (!net->ipv6.ip6_null_entry)
6488 goto out_fib6_null_entry;
6489 net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6490 dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
6491 ip6_template_metrics, true);
6492 INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->rt6i_uncached);
6493
6494 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6495 net->ipv6.fib6_has_custom_rules = false;
6496 net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
6497 sizeof(*net->ipv6.ip6_prohibit_entry),
6498 GFP_KERNEL);
6499 if (!net->ipv6.ip6_prohibit_entry)
6500 goto out_ip6_null_entry;
6501 net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6502 dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
6503 ip6_template_metrics, true);
6504 INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->rt6i_uncached);
6505
6506 net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
6507 sizeof(*net->ipv6.ip6_blk_hole_entry),
6508 GFP_KERNEL);
6509 if (!net->ipv6.ip6_blk_hole_entry)
6510 goto out_ip6_prohibit_entry;
6511 net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6512 dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
6513 ip6_template_metrics, true);
6514 INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->rt6i_uncached);
6515 #ifdef CONFIG_IPV6_SUBTREES
6516 net->ipv6.fib6_routes_require_src = 0;
6517 #endif
6518 #endif
6519
6520 net->ipv6.sysctl.flush_delay = 0;
6521 net->ipv6.sysctl.ip6_rt_max_size = 4096;
6522 net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
6523 net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
6524 net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
6525 net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
6526 net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
6527 net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
6528 net->ipv6.sysctl.skip_notify_on_dev_down = 0;
6529
6530 net->ipv6.ip6_rt_gc_expire = 30*HZ;
6531
6532 ret = 0;
6533 out:
6534 return ret;
6535
6536 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6537 out_ip6_prohibit_entry:
6538 kfree(net->ipv6.ip6_prohibit_entry);
6539 out_ip6_null_entry:
6540 kfree(net->ipv6.ip6_null_entry);
6541 #endif
6542 out_fib6_null_entry:
6543 kfree(net->ipv6.fib6_null_entry);
6544 out_ip6_dst_entries:
6545 dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6546 out_ip6_dst_ops:
6547 goto out;
6548 }
6549
6550 static void __net_exit ip6_route_net_exit(struct net *net)
6551 {
6552 kfree(net->ipv6.fib6_null_entry);
6553 kfree(net->ipv6.ip6_null_entry);
6554 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6555 kfree(net->ipv6.ip6_prohibit_entry);
6556 kfree(net->ipv6.ip6_blk_hole_entry);
6557 #endif
6558 dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6559 }
6560
6561 static int __net_init ip6_route_net_init_late(struct net *net)
6562 {
6563 #ifdef CONFIG_PROC_FS
6564 proc_create_net("ipv6_route", 0, net->proc_net, &ipv6_route_seq_ops,
6565 sizeof(struct ipv6_route_iter));
6566 proc_create_net_single("rt6_stats", 0444, net->proc_net,
6567 rt6_stats_seq_show, NULL);
6568 #endif
6569 return 0;
6570 }
6571
6572 static void __net_exit ip6_route_net_exit_late(struct net *net)
6573 {
6574 #ifdef CONFIG_PROC_FS
6575 remove_proc_entry("ipv6_route", net->proc_net);
6576 remove_proc_entry("rt6_stats", net->proc_net);
6577 #endif
6578 }
6579
6580 static struct pernet_operations ip6_route_net_ops = {
6581 .init = ip6_route_net_init,
6582 .exit = ip6_route_net_exit,
6583 };
6584
6585 static int __net_init ipv6_inetpeer_init(struct net *net)
6586 {
6587 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
6588
6589 if (!bp)
6590 return -ENOMEM;
6591 inet_peer_base_init(bp);
6592 net->ipv6.peers = bp;
6593 return 0;
6594 }
6595
6596 static void __net_exit ipv6_inetpeer_exit(struct net *net)
6597 {
6598 struct inet_peer_base *bp = net->ipv6.peers;
6599
6600 net->ipv6.peers = NULL;
6601 inetpeer_invalidate_tree(bp);
6602 kfree(bp);
6603 }
6604
6605 static struct pernet_operations ipv6_inetpeer_ops = {
6606 .init = ipv6_inetpeer_init,
6607 .exit = ipv6_inetpeer_exit,
6608 };
6609
6610 static struct pernet_operations ip6_route_net_late_ops = {
6611 .init = ip6_route_net_init_late,
6612 .exit = ip6_route_net_exit_late,
6613 };
6614
6615 static struct notifier_block ip6_route_dev_notifier = {
6616 .notifier_call = ip6_route_dev_notify,
6617 .priority = ADDRCONF_NOTIFY_PRIORITY - 10,
6618 };
6619
6620 void __init ip6_route_init_special_entries(void)
6621 {
6622 /* Registering of the loopback is done before this portion of code,
6623 * the loopback reference in rt6_info will not be taken, do it
6624 * manually for init_net */
6625 init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
6626 init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
6627 init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6628 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6629 init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
6630 init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6631 init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
6632 init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6633 #endif
6634 }
6635
6636 #if IS_BUILTIN(CONFIG_IPV6)
6637 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6638 DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt)
6639
6640 BTF_ID_LIST(btf_fib6_info_id)
6641 BTF_ID(struct, fib6_info)
6642
6643 static const struct bpf_iter_seq_info ipv6_route_seq_info = {
6644 .seq_ops = &ipv6_route_seq_ops,
6645 .init_seq_private = bpf_iter_init_seq_net,
6646 .fini_seq_private = bpf_iter_fini_seq_net,
6647 .seq_priv_size = sizeof(struct ipv6_route_iter),
6648 };
6649
6650 static struct bpf_iter_reg ipv6_route_reg_info = {
6651 .target = "ipv6_route",
6652 .ctx_arg_info_size = 1,
6653 .ctx_arg_info = {
6654 { offsetof(struct bpf_iter__ipv6_route, rt),
6655 PTR_TO_BTF_ID_OR_NULL },
6656 },
6657 .seq_info = &ipv6_route_seq_info,
6658 };
6659
6660 static int __init bpf_iter_register(void)
6661 {
6662 ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id;
6663 return bpf_iter_reg_target(&ipv6_route_reg_info);
6664 }
6665
6666 static void bpf_iter_unregister(void)
6667 {
6668 bpf_iter_unreg_target(&ipv6_route_reg_info);
6669 }
6670 #endif
6671 #endif
6672
6673 int __init ip6_route_init(void)
6674 {
6675 int ret;
6676 int cpu;
6677
6678 ret = -ENOMEM;
6679 ip6_dst_ops_template.kmem_cachep =
6680 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
6681 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
6682 if (!ip6_dst_ops_template.kmem_cachep)
6683 goto out;
6684
6685 ret = dst_entries_init(&ip6_dst_blackhole_ops);
6686 if (ret)
6687 goto out_kmem_cache;
6688
6689 ret = register_pernet_subsys(&ipv6_inetpeer_ops);
6690 if (ret)
6691 goto out_dst_entries;
6692
6693 ret = register_pernet_subsys(&ip6_route_net_ops);
6694 if (ret)
6695 goto out_register_inetpeer;
6696
6697 ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
6698
6699 ret = fib6_init();
6700 if (ret)
6701 goto out_register_subsys;
6702
6703 ret = xfrm6_init();
6704 if (ret)
6705 goto out_fib6_init;
6706
6707 ret = fib6_rules_init();
6708 if (ret)
6709 goto xfrm6_init;
6710
6711 ret = register_pernet_subsys(&ip6_route_net_late_ops);
6712 if (ret)
6713 goto fib6_rules_init;
6714
6715 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
6716 inet6_rtm_newroute, NULL, 0);
6717 if (ret < 0)
6718 goto out_register_late_subsys;
6719
6720 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
6721 inet6_rtm_delroute, NULL, 0);
6722 if (ret < 0)
6723 goto out_register_late_subsys;
6724
6725 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
6726 inet6_rtm_getroute, NULL,
6727 RTNL_FLAG_DOIT_UNLOCKED);
6728 if (ret < 0)
6729 goto out_register_late_subsys;
6730
6731 ret = register_netdevice_notifier(&ip6_route_dev_notifier);
6732 if (ret)
6733 goto out_register_late_subsys;
6734
6735 #if IS_BUILTIN(CONFIG_IPV6)
6736 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6737 ret = bpf_iter_register();
6738 if (ret)
6739 goto out_register_late_subsys;
6740 #endif
6741 #endif
6742
6743 for_each_possible_cpu(cpu) {
6744 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
6745
6746 INIT_LIST_HEAD(&ul->head);
6747 spin_lock_init(&ul->lock);
6748 }
6749
6750 out:
6751 return ret;
6752
6753 out_register_late_subsys:
6754 rtnl_unregister_all(PF_INET6);
6755 unregister_pernet_subsys(&ip6_route_net_late_ops);
6756 fib6_rules_init:
6757 fib6_rules_cleanup();
6758 xfrm6_init:
6759 xfrm6_fini();
6760 out_fib6_init:
6761 fib6_gc_cleanup();
6762 out_register_subsys:
6763 unregister_pernet_subsys(&ip6_route_net_ops);
6764 out_register_inetpeer:
6765 unregister_pernet_subsys(&ipv6_inetpeer_ops);
6766 out_dst_entries:
6767 dst_entries_destroy(&ip6_dst_blackhole_ops);
6768 out_kmem_cache:
6769 kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6770 goto out;
6771 }
6772
6773 void ip6_route_cleanup(void)
6774 {
6775 #if IS_BUILTIN(CONFIG_IPV6)
6776 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6777 bpf_iter_unregister();
6778 #endif
6779 #endif
6780 unregister_netdevice_notifier(&ip6_route_dev_notifier);
6781 unregister_pernet_subsys(&ip6_route_net_late_ops);
6782 fib6_rules_cleanup();
6783 xfrm6_fini();
6784 fib6_gc_cleanup();
6785 unregister_pernet_subsys(&ipv6_inetpeer_ops);
6786 unregister_pernet_subsys(&ip6_route_net_ops);
6787 dst_entries_destroy(&ip6_dst_blackhole_ops);
6788 kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6789 }
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