1 /*
2 * Linux INET6 implementation
3 * FIB front-end.
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * $Id: route.c,v 1.56 2001/10/31 21:55:55 davem Exp $
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 */
15
16 /* Changes:
17 *
18 * YOSHIFUJI Hideaki @USAGI
19 * reworked default router selection.
20 * - respect outgoing interface
21 * - select from (probably) reachable routers (i.e.
22 * routers in REACHABLE, STALE, DELAY or PROBE states).
23 * - always select the same router if it is (probably)
24 * reachable. otherwise, round-robin the list.
25 * Ville Nuorvala
26 * Fixed routing subtrees.
27 */
28
29 #include <linux/capability.h>
30 #include <linux/errno.h>
31 #include <linux/types.h>
32 #include <linux/times.h>
33 #include <linux/socket.h>
34 #include <linux/sockios.h>
35 #include <linux/net.h>
36 #include <linux/route.h>
37 #include <linux/netdevice.h>
38 #include <linux/in6.h>
39 #include <linux/init.h>
40 #include <linux/if_arp.h>
41 #include <linux/proc_fs.h>
42 #include <linux/seq_file.h>
43 #include <net/net_namespace.h>
44 #include <net/snmp.h>
45 #include <net/ipv6.h>
46 #include <net/ip6_fib.h>
47 #include <net/ip6_route.h>
48 #include <net/ndisc.h>
49 #include <net/addrconf.h>
50 #include <net/tcp.h>
51 #include <linux/rtnetlink.h>
52 #include <net/dst.h>
53 #include <net/xfrm.h>
54 #include <net/netevent.h>
55 #include <net/netlink.h>
56
57 #include <asm/uaccess.h>
58
59 #ifdef CONFIG_SYSCTL
60 #include <linux/sysctl.h>
61 #endif
62
63 /* Set to 3 to get tracing. */
64 #define RT6_DEBUG 2
65
66 #if RT6_DEBUG >= 3
67 #define RDBG(x) printk x
68 #define RT6_TRACE(x...) printk(KERN_DEBUG x)
69 #else
70 #define RDBG(x)
71 #define RT6_TRACE(x...) do { ; } while (0)
72 #endif
73
74 #define CLONE_OFFLINK_ROUTE 0
75
76 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort);
77 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie);
78 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
79 static void ip6_dst_destroy(struct dst_entry *);
80 static void ip6_dst_ifdown(struct dst_entry *,
81 struct net_device *dev, int how);
82 static int ip6_dst_gc(struct dst_ops *ops);
83
84 static int ip6_pkt_discard(struct sk_buff *skb);
85 static int ip6_pkt_discard_out(struct sk_buff *skb);
86 static void ip6_link_failure(struct sk_buff *skb);
87 static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
88
89 #ifdef CONFIG_IPV6_ROUTE_INFO
90 static struct rt6_info *rt6_add_route_info(struct in6_addr *prefix, int prefixlen,
91 struct in6_addr *gwaddr, int ifindex,
92 unsigned pref);
93 static struct rt6_info *rt6_get_route_info(struct in6_addr *prefix, int prefixlen,
94 struct in6_addr *gwaddr, int ifindex);
95 #endif
96
97 static struct dst_ops ip6_dst_ops = {
98 .family = AF_INET6,
99 .protocol = __constant_htons(ETH_P_IPV6),
100 .gc = ip6_dst_gc,
101 .gc_thresh = 1024,
102 .check = ip6_dst_check,
103 .destroy = ip6_dst_destroy,
104 .ifdown = ip6_dst_ifdown,
105 .negative_advice = ip6_negative_advice,
106 .link_failure = ip6_link_failure,
107 .update_pmtu = ip6_rt_update_pmtu,
108 .local_out = __ip6_local_out,
109 .entry_size = sizeof(struct rt6_info),
110 .entries = ATOMIC_INIT(0),
111 };
112
113 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
114 {
115 }
116
117 static struct dst_ops ip6_dst_blackhole_ops = {
118 .family = AF_INET6,
119 .protocol = __constant_htons(ETH_P_IPV6),
120 .destroy = ip6_dst_destroy,
121 .check = ip6_dst_check,
122 .update_pmtu = ip6_rt_blackhole_update_pmtu,
123 .entry_size = sizeof(struct rt6_info),
124 .entries = ATOMIC_INIT(0),
125 };
126
127 struct rt6_info ip6_null_entry = {
128 .u = {
129 .dst = {
130 .__refcnt = ATOMIC_INIT(1),
131 .__use = 1,
132 .obsolete = -1,
133 .error = -ENETUNREACH,
134 .metrics = { [RTAX_HOPLIMIT - 1] = 255, },
135 .input = ip6_pkt_discard,
136 .output = ip6_pkt_discard_out,
137 .ops = &ip6_dst_ops,
138 .path = (struct dst_entry*)&ip6_null_entry,
139 }
140 },
141 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP),
142 .rt6i_metric = ~(u32) 0,
143 .rt6i_ref = ATOMIC_INIT(1),
144 };
145
146 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
147
148 static int ip6_pkt_prohibit(struct sk_buff *skb);
149 static int ip6_pkt_prohibit_out(struct sk_buff *skb);
150
151 struct rt6_info ip6_prohibit_entry = {
152 .u = {
153 .dst = {
154 .__refcnt = ATOMIC_INIT(1),
155 .__use = 1,
156 .obsolete = -1,
157 .error = -EACCES,
158 .metrics = { [RTAX_HOPLIMIT - 1] = 255, },
159 .input = ip6_pkt_prohibit,
160 .output = ip6_pkt_prohibit_out,
161 .ops = &ip6_dst_ops,
162 .path = (struct dst_entry*)&ip6_prohibit_entry,
163 }
164 },
165 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP),
166 .rt6i_metric = ~(u32) 0,
167 .rt6i_ref = ATOMIC_INIT(1),
168 };
169
170 struct rt6_info ip6_blk_hole_entry = {
171 .u = {
172 .dst = {
173 .__refcnt = ATOMIC_INIT(1),
174 .__use = 1,
175 .obsolete = -1,
176 .error = -EINVAL,
177 .metrics = { [RTAX_HOPLIMIT - 1] = 255, },
178 .input = dst_discard,
179 .output = dst_discard,
180 .ops = &ip6_dst_ops,
181 .path = (struct dst_entry*)&ip6_blk_hole_entry,
182 }
183 },
184 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP),
185 .rt6i_metric = ~(u32) 0,
186 .rt6i_ref = ATOMIC_INIT(1),
187 };
188
189 #endif
190
191 /* allocate dst with ip6_dst_ops */
192 static __inline__ struct rt6_info *ip6_dst_alloc(void)
193 {
194 return (struct rt6_info *)dst_alloc(&ip6_dst_ops);
195 }
196
197 static void ip6_dst_destroy(struct dst_entry *dst)
198 {
199 struct rt6_info *rt = (struct rt6_info *)dst;
200 struct inet6_dev *idev = rt->rt6i_idev;
201
202 if (idev != NULL) {
203 rt->rt6i_idev = NULL;
204 in6_dev_put(idev);
205 }
206 }
207
208 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
209 int how)
210 {
211 struct rt6_info *rt = (struct rt6_info *)dst;
212 struct inet6_dev *idev = rt->rt6i_idev;
213 struct net_device *loopback_dev =
214 dev->nd_net->loopback_dev;
215
216 if (dev != loopback_dev && idev != NULL && idev->dev == dev) {
217 struct inet6_dev *loopback_idev =
218 in6_dev_get(loopback_dev);
219 if (loopback_idev != NULL) {
220 rt->rt6i_idev = loopback_idev;
221 in6_dev_put(idev);
222 }
223 }
224 }
225
226 static __inline__ int rt6_check_expired(const struct rt6_info *rt)
227 {
228 return (rt->rt6i_flags & RTF_EXPIRES &&
229 time_after(jiffies, rt->rt6i_expires));
230 }
231
232 static inline int rt6_need_strict(struct in6_addr *daddr)
233 {
234 return (ipv6_addr_type(daddr) &
235 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
236 }
237
238 /*
239 * Route lookup. Any table->tb6_lock is implied.
240 */
241
242 static __inline__ struct rt6_info *rt6_device_match(struct rt6_info *rt,
243 int oif,
244 int strict)
245 {
246 struct rt6_info *local = NULL;
247 struct rt6_info *sprt;
248
249 if (oif) {
250 for (sprt = rt; sprt; sprt = sprt->u.dst.rt6_next) {
251 struct net_device *dev = sprt->rt6i_dev;
252 if (dev->ifindex == oif)
253 return sprt;
254 if (dev->flags & IFF_LOOPBACK) {
255 if (sprt->rt6i_idev == NULL ||
256 sprt->rt6i_idev->dev->ifindex != oif) {
257 if (strict && oif)
258 continue;
259 if (local && (!oif ||
260 local->rt6i_idev->dev->ifindex == oif))
261 continue;
262 }
263 local = sprt;
264 }
265 }
266
267 if (local)
268 return local;
269
270 if (strict)
271 return &ip6_null_entry;
272 }
273 return rt;
274 }
275
276 #ifdef CONFIG_IPV6_ROUTER_PREF
277 static void rt6_probe(struct rt6_info *rt)
278 {
279 struct neighbour *neigh = rt ? rt->rt6i_nexthop : NULL;
280 /*
281 * Okay, this does not seem to be appropriate
282 * for now, however, we need to check if it
283 * is really so; aka Router Reachability Probing.
284 *
285 * Router Reachability Probe MUST be rate-limited
286 * to no more than one per minute.
287 */
288 if (!neigh || (neigh->nud_state & NUD_VALID))
289 return;
290 read_lock_bh(&neigh->lock);
291 if (!(neigh->nud_state & NUD_VALID) &&
292 time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
293 struct in6_addr mcaddr;
294 struct in6_addr *target;
295
296 neigh->updated = jiffies;
297 read_unlock_bh(&neigh->lock);
298
299 target = (struct in6_addr *)&neigh->primary_key;
300 addrconf_addr_solict_mult(target, &mcaddr);
301 ndisc_send_ns(rt->rt6i_dev, NULL, target, &mcaddr, NULL);
302 } else
303 read_unlock_bh(&neigh->lock);
304 }
305 #else
306 static inline void rt6_probe(struct rt6_info *rt)
307 {
308 return;
309 }
310 #endif
311
312 /*
313 * Default Router Selection (RFC 2461 6.3.6)
314 */
315 static inline int rt6_check_dev(struct rt6_info *rt, int oif)
316 {
317 struct net_device *dev = rt->rt6i_dev;
318 if (!oif || dev->ifindex == oif)
319 return 2;
320 if ((dev->flags & IFF_LOOPBACK) &&
321 rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif)
322 return 1;
323 return 0;
324 }
325
326 static inline int rt6_check_neigh(struct rt6_info *rt)
327 {
328 struct neighbour *neigh = rt->rt6i_nexthop;
329 int m;
330 if (rt->rt6i_flags & RTF_NONEXTHOP ||
331 !(rt->rt6i_flags & RTF_GATEWAY))
332 m = 1;
333 else if (neigh) {
334 read_lock_bh(&neigh->lock);
335 if (neigh->nud_state & NUD_VALID)
336 m = 2;
337 #ifdef CONFIG_IPV6_ROUTER_PREF
338 else if (neigh->nud_state & NUD_FAILED)
339 m = 0;
340 #endif
341 else
342 m = 1;
343 read_unlock_bh(&neigh->lock);
344 } else
345 m = 0;
346 return m;
347 }
348
349 static int rt6_score_route(struct rt6_info *rt, int oif,
350 int strict)
351 {
352 int m, n;
353
354 m = rt6_check_dev(rt, oif);
355 if (!m && (strict & RT6_LOOKUP_F_IFACE))
356 return -1;
357 #ifdef CONFIG_IPV6_ROUTER_PREF
358 m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2;
359 #endif
360 n = rt6_check_neigh(rt);
361 if (!n && (strict & RT6_LOOKUP_F_REACHABLE))
362 return -1;
363 return m;
364 }
365
366 static struct rt6_info *find_match(struct rt6_info *rt, int oif, int strict,
367 int *mpri, struct rt6_info *match)
368 {
369 int m;
370
371 if (rt6_check_expired(rt))
372 goto out;
373
374 m = rt6_score_route(rt, oif, strict);
375 if (m < 0)
376 goto out;
377
378 if (m > *mpri) {
379 if (strict & RT6_LOOKUP_F_REACHABLE)
380 rt6_probe(match);
381 *mpri = m;
382 match = rt;
383 } else if (strict & RT6_LOOKUP_F_REACHABLE) {
384 rt6_probe(rt);
385 }
386
387 out:
388 return match;
389 }
390
391 static struct rt6_info *find_rr_leaf(struct fib6_node *fn,
392 struct rt6_info *rr_head,
393 u32 metric, int oif, int strict)
394 {
395 struct rt6_info *rt, *match;
396 int mpri = -1;
397
398 match = NULL;
399 for (rt = rr_head; rt && rt->rt6i_metric == metric;
400 rt = rt->u.dst.rt6_next)
401 match = find_match(rt, oif, strict, &mpri, match);
402 for (rt = fn->leaf; rt && rt != rr_head && rt->rt6i_metric == metric;
403 rt = rt->u.dst.rt6_next)
404 match = find_match(rt, oif, strict, &mpri, match);
405
406 return match;
407 }
408
409 static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict)
410 {
411 struct rt6_info *match, *rt0;
412
413 RT6_TRACE("%s(fn->leaf=%p, oif=%d)\n",
414 __FUNCTION__, fn->leaf, oif);
415
416 rt0 = fn->rr_ptr;
417 if (!rt0)
418 fn->rr_ptr = rt0 = fn->leaf;
419
420 match = find_rr_leaf(fn, rt0, rt0->rt6i_metric, oif, strict);
421
422 if (!match &&
423 (strict & RT6_LOOKUP_F_REACHABLE)) {
424 struct rt6_info *next = rt0->u.dst.rt6_next;
425
426 /* no entries matched; do round-robin */
427 if (!next || next->rt6i_metric != rt0->rt6i_metric)
428 next = fn->leaf;
429
430 if (next != rt0)
431 fn->rr_ptr = next;
432 }
433
434 RT6_TRACE("%s() => %p\n",
435 __FUNCTION__, match);
436
437 return (match ? match : &ip6_null_entry);
438 }
439
440 #ifdef CONFIG_IPV6_ROUTE_INFO
441 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
442 struct in6_addr *gwaddr)
443 {
444 struct route_info *rinfo = (struct route_info *) opt;
445 struct in6_addr prefix_buf, *prefix;
446 unsigned int pref;
447 u32 lifetime;
448 struct rt6_info *rt;
449
450 if (len < sizeof(struct route_info)) {
451 return -EINVAL;
452 }
453
454 /* Sanity check for prefix_len and length */
455 if (rinfo->length > 3) {
456 return -EINVAL;
457 } else if (rinfo->prefix_len > 128) {
458 return -EINVAL;
459 } else if (rinfo->prefix_len > 64) {
460 if (rinfo->length < 2) {
461 return -EINVAL;
462 }
463 } else if (rinfo->prefix_len > 0) {
464 if (rinfo->length < 1) {
465 return -EINVAL;
466 }
467 }
468
469 pref = rinfo->route_pref;
470 if (pref == ICMPV6_ROUTER_PREF_INVALID)
471 pref = ICMPV6_ROUTER_PREF_MEDIUM;
472
473 lifetime = ntohl(rinfo->lifetime);
474 if (lifetime == 0xffffffff) {
475 /* infinity */
476 } else if (lifetime > 0x7fffffff/HZ) {
477 /* Avoid arithmetic overflow */
478 lifetime = 0x7fffffff/HZ - 1;
479 }
480
481 if (rinfo->length == 3)
482 prefix = (struct in6_addr *)rinfo->prefix;
483 else {
484 /* this function is safe */
485 ipv6_addr_prefix(&prefix_buf,
486 (struct in6_addr *)rinfo->prefix,
487 rinfo->prefix_len);
488 prefix = &prefix_buf;
489 }
490
491 rt = rt6_get_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex);
492
493 if (rt && !lifetime) {
494 ip6_del_rt(rt);
495 rt = NULL;
496 }
497
498 if (!rt && lifetime)
499 rt = rt6_add_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex,
500 pref);
501 else if (rt)
502 rt->rt6i_flags = RTF_ROUTEINFO |
503 (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
504
505 if (rt) {
506 if (lifetime == 0xffffffff) {
507 rt->rt6i_flags &= ~RTF_EXPIRES;
508 } else {
509 rt->rt6i_expires = jiffies + HZ * lifetime;
510 rt->rt6i_flags |= RTF_EXPIRES;
511 }
512 dst_release(&rt->u.dst);
513 }
514 return 0;
515 }
516 #endif
517
518 #define BACKTRACK(saddr) \
519 do { \
520 if (rt == &ip6_null_entry) { \
521 struct fib6_node *pn; \
522 while (1) { \
523 if (fn->fn_flags & RTN_TL_ROOT) \
524 goto out; \
525 pn = fn->parent; \
526 if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn) \
527 fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr); \
528 else \
529 fn = pn; \
530 if (fn->fn_flags & RTN_RTINFO) \
531 goto restart; \
532 } \
533 } \
534 } while(0)
535
536 static struct rt6_info *ip6_pol_route_lookup(struct fib6_table *table,
537 struct flowi *fl, int flags)
538 {
539 struct fib6_node *fn;
540 struct rt6_info *rt;
541
542 read_lock_bh(&table->tb6_lock);
543 fn = fib6_lookup(&table->tb6_root, &fl->fl6_dst, &fl->fl6_src);
544 restart:
545 rt = fn->leaf;
546 rt = rt6_device_match(rt, fl->oif, flags);
547 BACKTRACK(&fl->fl6_src);
548 out:
549 dst_use(&rt->u.dst, jiffies);
550 read_unlock_bh(&table->tb6_lock);
551 return rt;
552
553 }
554
555 struct rt6_info *rt6_lookup(struct in6_addr *daddr, struct in6_addr *saddr,
556 int oif, int strict)
557 {
558 struct flowi fl = {
559 .oif = oif,
560 .nl_u = {
561 .ip6_u = {
562 .daddr = *daddr,
563 },
564 },
565 };
566 struct dst_entry *dst;
567 int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
568
569 if (saddr) {
570 memcpy(&fl.fl6_src, saddr, sizeof(*saddr));
571 flags |= RT6_LOOKUP_F_HAS_SADDR;
572 }
573
574 dst = fib6_rule_lookup(&fl, flags, ip6_pol_route_lookup);
575 if (dst->error == 0)
576 return (struct rt6_info *) dst;
577
578 dst_release(dst);
579
580 return NULL;
581 }
582
583 EXPORT_SYMBOL(rt6_lookup);
584
585 /* ip6_ins_rt is called with FREE table->tb6_lock.
586 It takes new route entry, the addition fails by any reason the
587 route is freed. In any case, if caller does not hold it, it may
588 be destroyed.
589 */
590
591 static int __ip6_ins_rt(struct rt6_info *rt, struct nl_info *info)
592 {
593 int err;
594 struct fib6_table *table;
595
596 table = rt->rt6i_table;
597 write_lock_bh(&table->tb6_lock);
598 err = fib6_add(&table->tb6_root, rt, info);
599 write_unlock_bh(&table->tb6_lock);
600
601 return err;
602 }
603
604 int ip6_ins_rt(struct rt6_info *rt)
605 {
606 struct nl_info info = {
607 .nl_net = &init_net,
608 };
609 return __ip6_ins_rt(rt, &info);
610 }
611
612 static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, struct in6_addr *daddr,
613 struct in6_addr *saddr)
614 {
615 struct rt6_info *rt;
616
617 /*
618 * Clone the route.
619 */
620
621 rt = ip6_rt_copy(ort);
622
623 if (rt) {
624 if (!(rt->rt6i_flags&RTF_GATEWAY)) {
625 if (rt->rt6i_dst.plen != 128 &&
626 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr))
627 rt->rt6i_flags |= RTF_ANYCAST;
628 ipv6_addr_copy(&rt->rt6i_gateway, daddr);
629 }
630
631 ipv6_addr_copy(&rt->rt6i_dst.addr, daddr);
632 rt->rt6i_dst.plen = 128;
633 rt->rt6i_flags |= RTF_CACHE;
634 rt->u.dst.flags |= DST_HOST;
635
636 #ifdef CONFIG_IPV6_SUBTREES
637 if (rt->rt6i_src.plen && saddr) {
638 ipv6_addr_copy(&rt->rt6i_src.addr, saddr);
639 rt->rt6i_src.plen = 128;
640 }
641 #endif
642
643 rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway);
644
645 }
646
647 return rt;
648 }
649
650 static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort, struct in6_addr *daddr)
651 {
652 struct rt6_info *rt = ip6_rt_copy(ort);
653 if (rt) {
654 ipv6_addr_copy(&rt->rt6i_dst.addr, daddr);
655 rt->rt6i_dst.plen = 128;
656 rt->rt6i_flags |= RTF_CACHE;
657 rt->u.dst.flags |= DST_HOST;
658 rt->rt6i_nexthop = neigh_clone(ort->rt6i_nexthop);
659 }
660 return rt;
661 }
662
663 static struct rt6_info *ip6_pol_route(struct fib6_table *table, int oif,
664 struct flowi *fl, int flags)
665 {
666 struct fib6_node *fn;
667 struct rt6_info *rt, *nrt;
668 int strict = 0;
669 int attempts = 3;
670 int err;
671 int reachable = ipv6_devconf.forwarding ? 0 : RT6_LOOKUP_F_REACHABLE;
672
673 strict |= flags & RT6_LOOKUP_F_IFACE;
674
675 relookup:
676 read_lock_bh(&table->tb6_lock);
677
678 restart_2:
679 fn = fib6_lookup(&table->tb6_root, &fl->fl6_dst, &fl->fl6_src);
680
681 restart:
682 rt = rt6_select(fn, oif, strict | reachable);
683 BACKTRACK(&fl->fl6_src);
684 if (rt == &ip6_null_entry ||
685 rt->rt6i_flags & RTF_CACHE)
686 goto out;
687
688 dst_hold(&rt->u.dst);
689 read_unlock_bh(&table->tb6_lock);
690
691 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
692 nrt = rt6_alloc_cow(rt, &fl->fl6_dst, &fl->fl6_src);
693 else {
694 #if CLONE_OFFLINK_ROUTE
695 nrt = rt6_alloc_clone(rt, &fl->fl6_dst);
696 #else
697 goto out2;
698 #endif
699 }
700
701 dst_release(&rt->u.dst);
702 rt = nrt ? : &ip6_null_entry;
703
704 dst_hold(&rt->u.dst);
705 if (nrt) {
706 err = ip6_ins_rt(nrt);
707 if (!err)
708 goto out2;
709 }
710
711 if (--attempts <= 0)
712 goto out2;
713
714 /*
715 * Race condition! In the gap, when table->tb6_lock was
716 * released someone could insert this route. Relookup.
717 */
718 dst_release(&rt->u.dst);
719 goto relookup;
720
721 out:
722 if (reachable) {
723 reachable = 0;
724 goto restart_2;
725 }
726 dst_hold(&rt->u.dst);
727 read_unlock_bh(&table->tb6_lock);
728 out2:
729 rt->u.dst.lastuse = jiffies;
730 rt->u.dst.__use++;
731
732 return rt;
733 }
734
735 static struct rt6_info *ip6_pol_route_input(struct fib6_table *table,
736 struct flowi *fl, int flags)
737 {
738 return ip6_pol_route(table, fl->iif, fl, flags);
739 }
740
741 void ip6_route_input(struct sk_buff *skb)
742 {
743 struct ipv6hdr *iph = ipv6_hdr(skb);
744 int flags = RT6_LOOKUP_F_HAS_SADDR;
745 struct flowi fl = {
746 .iif = skb->dev->ifindex,
747 .nl_u = {
748 .ip6_u = {
749 .daddr = iph->daddr,
750 .saddr = iph->saddr,
751 .flowlabel = (* (__be32 *) iph)&IPV6_FLOWINFO_MASK,
752 },
753 },
754 .mark = skb->mark,
755 .proto = iph->nexthdr,
756 };
757
758 if (rt6_need_strict(&iph->daddr))
759 flags |= RT6_LOOKUP_F_IFACE;
760
761 skb->dst = fib6_rule_lookup(&fl, flags, ip6_pol_route_input);
762 }
763
764 static struct rt6_info *ip6_pol_route_output(struct fib6_table *table,
765 struct flowi *fl, int flags)
766 {
767 return ip6_pol_route(table, fl->oif, fl, flags);
768 }
769
770 struct dst_entry * ip6_route_output(struct sock *sk, struct flowi *fl)
771 {
772 int flags = 0;
773
774 if (rt6_need_strict(&fl->fl6_dst))
775 flags |= RT6_LOOKUP_F_IFACE;
776
777 if (!ipv6_addr_any(&fl->fl6_src))
778 flags |= RT6_LOOKUP_F_HAS_SADDR;
779
780 return fib6_rule_lookup(fl, flags, ip6_pol_route_output);
781 }
782
783 EXPORT_SYMBOL(ip6_route_output);
784
785 int ip6_dst_blackhole(struct sock *sk, struct dst_entry **dstp, struct flowi *fl)
786 {
787 struct rt6_info *ort = (struct rt6_info *) *dstp;
788 struct rt6_info *rt = (struct rt6_info *)
789 dst_alloc(&ip6_dst_blackhole_ops);
790 struct dst_entry *new = NULL;
791
792 if (rt) {
793 new = &rt->u.dst;
794
795 atomic_set(&new->__refcnt, 1);
796 new->__use = 1;
797 new->input = dst_discard;
798 new->output = dst_discard;
799
800 memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
801 new->dev = ort->u.dst.dev;
802 if (new->dev)
803 dev_hold(new->dev);
804 rt->rt6i_idev = ort->rt6i_idev;
805 if (rt->rt6i_idev)
806 in6_dev_hold(rt->rt6i_idev);
807 rt->rt6i_expires = 0;
808
809 ipv6_addr_copy(&rt->rt6i_gateway, &ort->rt6i_gateway);
810 rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES;
811 rt->rt6i_metric = 0;
812
813 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
814 #ifdef CONFIG_IPV6_SUBTREES
815 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
816 #endif
817
818 dst_free(new);
819 }
820
821 dst_release(*dstp);
822 *dstp = new;
823 return (new ? 0 : -ENOMEM);
824 }
825 EXPORT_SYMBOL_GPL(ip6_dst_blackhole);
826
827 /*
828 * Destination cache support functions
829 */
830
831 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
832 {
833 struct rt6_info *rt;
834
835 rt = (struct rt6_info *) dst;
836
837 if (rt && rt->rt6i_node && (rt->rt6i_node->fn_sernum == cookie))
838 return dst;
839
840 return NULL;
841 }
842
843 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
844 {
845 struct rt6_info *rt = (struct rt6_info *) dst;
846
847 if (rt) {
848 if (rt->rt6i_flags & RTF_CACHE)
849 ip6_del_rt(rt);
850 else
851 dst_release(dst);
852 }
853 return NULL;
854 }
855
856 static void ip6_link_failure(struct sk_buff *skb)
857 {
858 struct rt6_info *rt;
859
860 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0, skb->dev);
861
862 rt = (struct rt6_info *) skb->dst;
863 if (rt) {
864 if (rt->rt6i_flags&RTF_CACHE) {
865 dst_set_expires(&rt->u.dst, 0);
866 rt->rt6i_flags |= RTF_EXPIRES;
867 } else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT))
868 rt->rt6i_node->fn_sernum = -1;
869 }
870 }
871
872 static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
873 {
874 struct rt6_info *rt6 = (struct rt6_info*)dst;
875
876 if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) {
877 rt6->rt6i_flags |= RTF_MODIFIED;
878 if (mtu < IPV6_MIN_MTU) {
879 mtu = IPV6_MIN_MTU;
880 dst->metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
881 }
882 dst->metrics[RTAX_MTU-1] = mtu;
883 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
884 }
885 }
886
887 static int ipv6_get_mtu(struct net_device *dev);
888
889 static inline unsigned int ipv6_advmss(unsigned int mtu)
890 {
891 mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
892
893 if (mtu < init_net.ipv6.sysctl.ip6_rt_min_advmss)
894 mtu = init_net.ipv6.sysctl.ip6_rt_min_advmss;
895
896 /*
897 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
898 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
899 * IPV6_MAXPLEN is also valid and means: "any MSS,
900 * rely only on pmtu discovery"
901 */
902 if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
903 mtu = IPV6_MAXPLEN;
904 return mtu;
905 }
906
907 static struct dst_entry *ndisc_dst_gc_list;
908 static DEFINE_SPINLOCK(ndisc_lock);
909
910 struct dst_entry *ndisc_dst_alloc(struct net_device *dev,
911 struct neighbour *neigh,
912 struct in6_addr *addr,
913 int (*output)(struct sk_buff *))
914 {
915 struct rt6_info *rt;
916 struct inet6_dev *idev = in6_dev_get(dev);
917
918 if (unlikely(idev == NULL))
919 return NULL;
920
921 rt = ip6_dst_alloc();
922 if (unlikely(rt == NULL)) {
923 in6_dev_put(idev);
924 goto out;
925 }
926
927 dev_hold(dev);
928 if (neigh)
929 neigh_hold(neigh);
930 else
931 neigh = ndisc_get_neigh(dev, addr);
932
933 rt->rt6i_dev = dev;
934 rt->rt6i_idev = idev;
935 rt->rt6i_nexthop = neigh;
936 atomic_set(&rt->u.dst.__refcnt, 1);
937 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = 255;
938 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev);
939 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst));
940 rt->u.dst.output = output;
941
942 #if 0 /* there's no chance to use these for ndisc */
943 rt->u.dst.flags = ipv6_addr_type(addr) & IPV6_ADDR_UNICAST
944 ? DST_HOST
945 : 0;
946 ipv6_addr_copy(&rt->rt6i_dst.addr, addr);
947 rt->rt6i_dst.plen = 128;
948 #endif
949
950 spin_lock_bh(&ndisc_lock);
951 rt->u.dst.next = ndisc_dst_gc_list;
952 ndisc_dst_gc_list = &rt->u.dst;
953 spin_unlock_bh(&ndisc_lock);
954
955 fib6_force_start_gc();
956
957 out:
958 return &rt->u.dst;
959 }
960
961 int ndisc_dst_gc(int *more)
962 {
963 struct dst_entry *dst, *next, **pprev;
964 int freed;
965
966 next = NULL;
967 freed = 0;
968
969 spin_lock_bh(&ndisc_lock);
970 pprev = &ndisc_dst_gc_list;
971
972 while ((dst = *pprev) != NULL) {
973 if (!atomic_read(&dst->__refcnt)) {
974 *pprev = dst->next;
975 dst_free(dst);
976 freed++;
977 } else {
978 pprev = &dst->next;
979 (*more)++;
980 }
981 }
982
983 spin_unlock_bh(&ndisc_lock);
984
985 return freed;
986 }
987
988 static int ip6_dst_gc(struct dst_ops *ops)
989 {
990 static unsigned expire = 30*HZ;
991 static unsigned long last_gc;
992 unsigned long now = jiffies;
993
994 if (time_after(last_gc + init_net.ipv6.sysctl.ip6_rt_gc_min_interval, now) &&
995 atomic_read(&ip6_dst_ops.entries) <= init_net.ipv6.sysctl.ip6_rt_max_size)
996 goto out;
997
998 expire++;
999 fib6_run_gc(expire);
1000 last_gc = now;
1001 if (atomic_read(&ip6_dst_ops.entries) < ip6_dst_ops.gc_thresh)
1002 expire = init_net.ipv6.sysctl.ip6_rt_gc_timeout>>1;
1003
1004 out:
1005 expire -= expire>>init_net.ipv6.sysctl.ip6_rt_gc_elasticity;
1006 return (atomic_read(&ip6_dst_ops.entries) > init_net.ipv6.sysctl.ip6_rt_max_size);
1007 }
1008
1009 /* Clean host part of a prefix. Not necessary in radix tree,
1010 but results in cleaner routing tables.
1011
1012 Remove it only when all the things will work!
1013 */
1014
1015 static int ipv6_get_mtu(struct net_device *dev)
1016 {
1017 int mtu = IPV6_MIN_MTU;
1018 struct inet6_dev *idev;
1019
1020 idev = in6_dev_get(dev);
1021 if (idev) {
1022 mtu = idev->cnf.mtu6;
1023 in6_dev_put(idev);
1024 }
1025 return mtu;
1026 }
1027
1028 int ipv6_get_hoplimit(struct net_device *dev)
1029 {
1030 int hoplimit = ipv6_devconf.hop_limit;
1031 struct inet6_dev *idev;
1032
1033 idev = in6_dev_get(dev);
1034 if (idev) {
1035 hoplimit = idev->cnf.hop_limit;
1036 in6_dev_put(idev);
1037 }
1038 return hoplimit;
1039 }
1040
1041 /*
1042 *
1043 */
1044
1045 int ip6_route_add(struct fib6_config *cfg)
1046 {
1047 int err;
1048 struct rt6_info *rt = NULL;
1049 struct net_device *dev = NULL;
1050 struct inet6_dev *idev = NULL;
1051 struct fib6_table *table;
1052 int addr_type;
1053
1054 if (cfg->fc_dst_len > 128 || cfg->fc_src_len > 128)
1055 return -EINVAL;
1056 #ifndef CONFIG_IPV6_SUBTREES
1057 if (cfg->fc_src_len)
1058 return -EINVAL;
1059 #endif
1060 if (cfg->fc_ifindex) {
1061 err = -ENODEV;
1062 dev = dev_get_by_index(&init_net, cfg->fc_ifindex);
1063 if (!dev)
1064 goto out;
1065 idev = in6_dev_get(dev);
1066 if (!idev)
1067 goto out;
1068 }
1069
1070 if (cfg->fc_metric == 0)
1071 cfg->fc_metric = IP6_RT_PRIO_USER;
1072
1073 table = fib6_new_table(cfg->fc_table);
1074 if (table == NULL) {
1075 err = -ENOBUFS;
1076 goto out;
1077 }
1078
1079 rt = ip6_dst_alloc();
1080
1081 if (rt == NULL) {
1082 err = -ENOMEM;
1083 goto out;
1084 }
1085
1086 rt->u.dst.obsolete = -1;
1087 rt->rt6i_expires = jiffies + clock_t_to_jiffies(cfg->fc_expires);
1088
1089 if (cfg->fc_protocol == RTPROT_UNSPEC)
1090 cfg->fc_protocol = RTPROT_BOOT;
1091 rt->rt6i_protocol = cfg->fc_protocol;
1092
1093 addr_type = ipv6_addr_type(&cfg->fc_dst);
1094
1095 if (addr_type & IPV6_ADDR_MULTICAST)
1096 rt->u.dst.input = ip6_mc_input;
1097 else
1098 rt->u.dst.input = ip6_forward;
1099
1100 rt->u.dst.output = ip6_output;
1101
1102 ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
1103 rt->rt6i_dst.plen = cfg->fc_dst_len;
1104 if (rt->rt6i_dst.plen == 128)
1105 rt->u.dst.flags = DST_HOST;
1106
1107 #ifdef CONFIG_IPV6_SUBTREES
1108 ipv6_addr_prefix(&rt->rt6i_src.addr, &cfg->fc_src, cfg->fc_src_len);
1109 rt->rt6i_src.plen = cfg->fc_src_len;
1110 #endif
1111
1112 rt->rt6i_metric = cfg->fc_metric;
1113
1114 /* We cannot add true routes via loopback here,
1115 they would result in kernel looping; promote them to reject routes
1116 */
1117 if ((cfg->fc_flags & RTF_REJECT) ||
1118 (dev && (dev->flags&IFF_LOOPBACK) && !(addr_type&IPV6_ADDR_LOOPBACK))) {
1119 /* hold loopback dev/idev if we haven't done so. */
1120 if (dev != init_net.loopback_dev) {
1121 if (dev) {
1122 dev_put(dev);
1123 in6_dev_put(idev);
1124 }
1125 dev = init_net.loopback_dev;
1126 dev_hold(dev);
1127 idev = in6_dev_get(dev);
1128 if (!idev) {
1129 err = -ENODEV;
1130 goto out;
1131 }
1132 }
1133 rt->u.dst.output = ip6_pkt_discard_out;
1134 rt->u.dst.input = ip6_pkt_discard;
1135 rt->u.dst.error = -ENETUNREACH;
1136 rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP;
1137 goto install_route;
1138 }
1139
1140 if (cfg->fc_flags & RTF_GATEWAY) {
1141 struct in6_addr *gw_addr;
1142 int gwa_type;
1143
1144 gw_addr = &cfg->fc_gateway;
1145 ipv6_addr_copy(&rt->rt6i_gateway, gw_addr);
1146 gwa_type = ipv6_addr_type(gw_addr);
1147
1148 if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
1149 struct rt6_info *grt;
1150
1151 /* IPv6 strictly inhibits using not link-local
1152 addresses as nexthop address.
1153 Otherwise, router will not able to send redirects.
1154 It is very good, but in some (rare!) circumstances
1155 (SIT, PtP, NBMA NOARP links) it is handy to allow
1156 some exceptions. --ANK
1157 */
1158 err = -EINVAL;
1159 if (!(gwa_type&IPV6_ADDR_UNICAST))
1160 goto out;
1161
1162 grt = rt6_lookup(gw_addr, NULL, cfg->fc_ifindex, 1);
1163
1164 err = -EHOSTUNREACH;
1165 if (grt == NULL)
1166 goto out;
1167 if (dev) {
1168 if (dev != grt->rt6i_dev) {
1169 dst_release(&grt->u.dst);
1170 goto out;
1171 }
1172 } else {
1173 dev = grt->rt6i_dev;
1174 idev = grt->rt6i_idev;
1175 dev_hold(dev);
1176 in6_dev_hold(grt->rt6i_idev);
1177 }
1178 if (!(grt->rt6i_flags&RTF_GATEWAY))
1179 err = 0;
1180 dst_release(&grt->u.dst);
1181
1182 if (err)
1183 goto out;
1184 }
1185 err = -EINVAL;
1186 if (dev == NULL || (dev->flags&IFF_LOOPBACK))
1187 goto out;
1188 }
1189
1190 err = -ENODEV;
1191 if (dev == NULL)
1192 goto out;
1193
1194 if (cfg->fc_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) {
1195 rt->rt6i_nexthop = __neigh_lookup_errno(&nd_tbl, &rt->rt6i_gateway, dev);
1196 if (IS_ERR(rt->rt6i_nexthop)) {
1197 err = PTR_ERR(rt->rt6i_nexthop);
1198 rt->rt6i_nexthop = NULL;
1199 goto out;
1200 }
1201 }
1202
1203 rt->rt6i_flags = cfg->fc_flags;
1204
1205 install_route:
1206 if (cfg->fc_mx) {
1207 struct nlattr *nla;
1208 int remaining;
1209
1210 nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
1211 int type = nla_type(nla);
1212
1213 if (type) {
1214 if (type > RTAX_MAX) {
1215 err = -EINVAL;
1216 goto out;
1217 }
1218
1219 rt->u.dst.metrics[type - 1] = nla_get_u32(nla);
1220 }
1221 }
1222 }
1223
1224 if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0)
1225 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = -1;
1226 if (!rt->u.dst.metrics[RTAX_MTU-1])
1227 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(dev);
1228 if (!rt->u.dst.metrics[RTAX_ADVMSS-1])
1229 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst));
1230 rt->u.dst.dev = dev;
1231 rt->rt6i_idev = idev;
1232 rt->rt6i_table = table;
1233 return __ip6_ins_rt(rt, &cfg->fc_nlinfo);
1234
1235 out:
1236 if (dev)
1237 dev_put(dev);
1238 if (idev)
1239 in6_dev_put(idev);
1240 if (rt)
1241 dst_free(&rt->u.dst);
1242 return err;
1243 }
1244
1245 static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info)
1246 {
1247 int err;
1248 struct fib6_table *table;
1249
1250 if (rt == &ip6_null_entry)
1251 return -ENOENT;
1252
1253 table = rt->rt6i_table;
1254 write_lock_bh(&table->tb6_lock);
1255
1256 err = fib6_del(rt, info);
1257 dst_release(&rt->u.dst);
1258
1259 write_unlock_bh(&table->tb6_lock);
1260
1261 return err;
1262 }
1263
1264 int ip6_del_rt(struct rt6_info *rt)
1265 {
1266 struct nl_info info = {
1267 .nl_net = &init_net,
1268 };
1269 return __ip6_del_rt(rt, &info);
1270 }
1271
1272 static int ip6_route_del(struct fib6_config *cfg)
1273 {
1274 struct fib6_table *table;
1275 struct fib6_node *fn;
1276 struct rt6_info *rt;
1277 int err = -ESRCH;
1278
1279 table = fib6_get_table(cfg->fc_table);
1280 if (table == NULL)
1281 return err;
1282
1283 read_lock_bh(&table->tb6_lock);
1284
1285 fn = fib6_locate(&table->tb6_root,
1286 &cfg->fc_dst, cfg->fc_dst_len,
1287 &cfg->fc_src, cfg->fc_src_len);
1288
1289 if (fn) {
1290 for (rt = fn->leaf; rt; rt = rt->u.dst.rt6_next) {
1291 if (cfg->fc_ifindex &&
1292 (rt->rt6i_dev == NULL ||
1293 rt->rt6i_dev->ifindex != cfg->fc_ifindex))
1294 continue;
1295 if (cfg->fc_flags & RTF_GATEWAY &&
1296 !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
1297 continue;
1298 if (cfg->fc_metric && cfg->fc_metric != rt->rt6i_metric)
1299 continue;
1300 dst_hold(&rt->u.dst);
1301 read_unlock_bh(&table->tb6_lock);
1302
1303 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
1304 }
1305 }
1306 read_unlock_bh(&table->tb6_lock);
1307
1308 return err;
1309 }
1310
1311 /*
1312 * Handle redirects
1313 */
1314 struct ip6rd_flowi {
1315 struct flowi fl;
1316 struct in6_addr gateway;
1317 };
1318
1319 static struct rt6_info *__ip6_route_redirect(struct fib6_table *table,
1320 struct flowi *fl,
1321 int flags)
1322 {
1323 struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl;
1324 struct rt6_info *rt;
1325 struct fib6_node *fn;
1326
1327 /*
1328 * Get the "current" route for this destination and
1329 * check if the redirect has come from approriate router.
1330 *
1331 * RFC 2461 specifies that redirects should only be
1332 * accepted if they come from the nexthop to the target.
1333 * Due to the way the routes are chosen, this notion
1334 * is a bit fuzzy and one might need to check all possible
1335 * routes.
1336 */
1337
1338 read_lock_bh(&table->tb6_lock);
1339 fn = fib6_lookup(&table->tb6_root, &fl->fl6_dst, &fl->fl6_src);
1340 restart:
1341 for (rt = fn->leaf; rt; rt = rt->u.dst.rt6_next) {
1342 /*
1343 * Current route is on-link; redirect is always invalid.
1344 *
1345 * Seems, previous statement is not true. It could
1346 * be node, which looks for us as on-link (f.e. proxy ndisc)
1347 * But then router serving it might decide, that we should
1348 * know truth 8)8) --ANK (980726).
1349 */
1350 if (rt6_check_expired(rt))
1351 continue;
1352 if (!(rt->rt6i_flags & RTF_GATEWAY))
1353 continue;
1354 if (fl->oif != rt->rt6i_dev->ifindex)
1355 continue;
1356 if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway))
1357 continue;
1358 break;
1359 }
1360
1361 if (!rt)
1362 rt = &ip6_null_entry;
1363 BACKTRACK(&fl->fl6_src);
1364 out:
1365 dst_hold(&rt->u.dst);
1366
1367 read_unlock_bh(&table->tb6_lock);
1368
1369 return rt;
1370 };
1371
1372 static struct rt6_info *ip6_route_redirect(struct in6_addr *dest,
1373 struct in6_addr *src,
1374 struct in6_addr *gateway,
1375 struct net_device *dev)
1376 {
1377 int flags = RT6_LOOKUP_F_HAS_SADDR;
1378 struct ip6rd_flowi rdfl = {
1379 .fl = {
1380 .oif = dev->ifindex,
1381 .nl_u = {
1382 .ip6_u = {
1383 .daddr = *dest,
1384 .saddr = *src,
1385 },
1386 },
1387 },
1388 .gateway = *gateway,
1389 };
1390
1391 if (rt6_need_strict(dest))
1392 flags |= RT6_LOOKUP_F_IFACE;
1393
1394 return (struct rt6_info *)fib6_rule_lookup((struct flowi *)&rdfl, flags, __ip6_route_redirect);
1395 }
1396
1397 void rt6_redirect(struct in6_addr *dest, struct in6_addr *src,
1398 struct in6_addr *saddr,
1399 struct neighbour *neigh, u8 *lladdr, int on_link)
1400 {
1401 struct rt6_info *rt, *nrt = NULL;
1402 struct netevent_redirect netevent;
1403
1404 rt = ip6_route_redirect(dest, src, saddr, neigh->dev);
1405
1406 if (rt == &ip6_null_entry) {
1407 if (net_ratelimit())
1408 printk(KERN_DEBUG "rt6_redirect: source isn't a valid nexthop "
1409 "for redirect target\n");
1410 goto out;
1411 }
1412
1413 /*
1414 * We have finally decided to accept it.
1415 */
1416
1417 neigh_update(neigh, lladdr, NUD_STALE,
1418 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1419 NEIGH_UPDATE_F_OVERRIDE|
1420 (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1421 NEIGH_UPDATE_F_ISROUTER))
1422 );
1423
1424 /*
1425 * Redirect received -> path was valid.
1426 * Look, redirects are sent only in response to data packets,
1427 * so that this nexthop apparently is reachable. --ANK
1428 */
1429 dst_confirm(&rt->u.dst);
1430
1431 /* Duplicate redirect: silently ignore. */
1432 if (neigh == rt->u.dst.neighbour)
1433 goto out;
1434
1435 nrt = ip6_rt_copy(rt);
1436 if (nrt == NULL)
1437 goto out;
1438
1439 nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
1440 if (on_link)
1441 nrt->rt6i_flags &= ~RTF_GATEWAY;
1442
1443 ipv6_addr_copy(&nrt->rt6i_dst.addr, dest);
1444 nrt->rt6i_dst.plen = 128;
1445 nrt->u.dst.flags |= DST_HOST;
1446
1447 ipv6_addr_copy(&nrt->rt6i_gateway, (struct in6_addr*)neigh->primary_key);
1448 nrt->rt6i_nexthop = neigh_clone(neigh);
1449 /* Reset pmtu, it may be better */
1450 nrt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(neigh->dev);
1451 nrt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&nrt->u.dst));
1452
1453 if (ip6_ins_rt(nrt))
1454 goto out;
1455
1456 netevent.old = &rt->u.dst;
1457 netevent.new = &nrt->u.dst;
1458 call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
1459
1460 if (rt->rt6i_flags&RTF_CACHE) {
1461 ip6_del_rt(rt);
1462 return;
1463 }
1464
1465 out:
1466 dst_release(&rt->u.dst);
1467 return;
1468 }
1469
1470 /*
1471 * Handle ICMP "packet too big" messages
1472 * i.e. Path MTU discovery
1473 */
1474
1475 void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr,
1476 struct net_device *dev, u32 pmtu)
1477 {
1478 struct rt6_info *rt, *nrt;
1479 int allfrag = 0;
1480
1481 rt = rt6_lookup(daddr, saddr, dev->ifindex, 0);
1482 if (rt == NULL)
1483 return;
1484
1485 if (pmtu >= dst_mtu(&rt->u.dst))
1486 goto out;
1487
1488 if (pmtu < IPV6_MIN_MTU) {
1489 /*
1490 * According to RFC2460, PMTU is set to the IPv6 Minimum Link
1491 * MTU (1280) and a fragment header should always be included
1492 * after a node receiving Too Big message reporting PMTU is
1493 * less than the IPv6 Minimum Link MTU.
1494 */
1495 pmtu = IPV6_MIN_MTU;
1496 allfrag = 1;
1497 }
1498
1499 /* New mtu received -> path was valid.
1500 They are sent only in response to data packets,
1501 so that this nexthop apparently is reachable. --ANK
1502 */
1503 dst_confirm(&rt->u.dst);
1504
1505 /* Host route. If it is static, it would be better
1506 not to override it, but add new one, so that
1507 when cache entry will expire old pmtu
1508 would return automatically.
1509 */
1510 if (rt->rt6i_flags & RTF_CACHE) {
1511 rt->u.dst.metrics[RTAX_MTU-1] = pmtu;
1512 if (allfrag)
1513 rt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
1514 dst_set_expires(&rt->u.dst, init_net.ipv6.sysctl.ip6_rt_mtu_expires);
1515 rt->rt6i_flags |= RTF_MODIFIED|RTF_EXPIRES;
1516 goto out;
1517 }
1518
1519 /* Network route.
1520 Two cases are possible:
1521 1. It is connected route. Action: COW
1522 2. It is gatewayed route or NONEXTHOP route. Action: clone it.
1523 */
1524 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
1525 nrt = rt6_alloc_cow(rt, daddr, saddr);
1526 else
1527 nrt = rt6_alloc_clone(rt, daddr);
1528
1529 if (nrt) {
1530 nrt->u.dst.metrics[RTAX_MTU-1] = pmtu;
1531 if (allfrag)
1532 nrt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
1533
1534 /* According to RFC 1981, detecting PMTU increase shouldn't be
1535 * happened within 5 mins, the recommended timer is 10 mins.
1536 * Here this route expiration time is set to ip6_rt_mtu_expires
1537 * which is 10 mins. After 10 mins the decreased pmtu is expired
1538 * and detecting PMTU increase will be automatically happened.
1539 */
1540 dst_set_expires(&nrt->u.dst, init_net.ipv6.sysctl.ip6_rt_mtu_expires);
1541 nrt->rt6i_flags |= RTF_DYNAMIC|RTF_EXPIRES;
1542
1543 ip6_ins_rt(nrt);
1544 }
1545 out:
1546 dst_release(&rt->u.dst);
1547 }
1548
1549 /*
1550 * Misc support functions
1551 */
1552
1553 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort)
1554 {
1555 struct rt6_info *rt = ip6_dst_alloc();
1556
1557 if (rt) {
1558 rt->u.dst.input = ort->u.dst.input;
1559 rt->u.dst.output = ort->u.dst.output;
1560
1561 memcpy(rt->u.dst.metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
1562 rt->u.dst.error = ort->u.dst.error;
1563 rt->u.dst.dev = ort->u.dst.dev;
1564 if (rt->u.dst.dev)
1565 dev_hold(rt->u.dst.dev);
1566 rt->rt6i_idev = ort->rt6i_idev;
1567 if (rt->rt6i_idev)
1568 in6_dev_hold(rt->rt6i_idev);
1569 rt->u.dst.lastuse = jiffies;
1570 rt->rt6i_expires = 0;
1571
1572 ipv6_addr_copy(&rt->rt6i_gateway, &ort->rt6i_gateway);
1573 rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES;
1574 rt->rt6i_metric = 0;
1575
1576 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
1577 #ifdef CONFIG_IPV6_SUBTREES
1578 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
1579 #endif
1580 rt->rt6i_table = ort->rt6i_table;
1581 }
1582 return rt;
1583 }
1584
1585 #ifdef CONFIG_IPV6_ROUTE_INFO
1586 static struct rt6_info *rt6_get_route_info(struct in6_addr *prefix, int prefixlen,
1587 struct in6_addr *gwaddr, int ifindex)
1588 {
1589 struct fib6_node *fn;
1590 struct rt6_info *rt = NULL;
1591 struct fib6_table *table;
1592
1593 table = fib6_get_table(RT6_TABLE_INFO);
1594 if (table == NULL)
1595 return NULL;
1596
1597 write_lock_bh(&table->tb6_lock);
1598 fn = fib6_locate(&table->tb6_root, prefix ,prefixlen, NULL, 0);
1599 if (!fn)
1600 goto out;
1601
1602 for (rt = fn->leaf; rt; rt = rt->u.dst.rt6_next) {
1603 if (rt->rt6i_dev->ifindex != ifindex)
1604 continue;
1605 if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
1606 continue;
1607 if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr))
1608 continue;
1609 dst_hold(&rt->u.dst);
1610 break;
1611 }
1612 out:
1613 write_unlock_bh(&table->tb6_lock);
1614 return rt;
1615 }
1616
1617 static struct rt6_info *rt6_add_route_info(struct in6_addr *prefix, int prefixlen,
1618 struct in6_addr *gwaddr, int ifindex,
1619 unsigned pref)
1620 {
1621 struct fib6_config cfg = {
1622 .fc_table = RT6_TABLE_INFO,
1623 .fc_metric = IP6_RT_PRIO_USER,
1624 .fc_ifindex = ifindex,
1625 .fc_dst_len = prefixlen,
1626 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
1627 RTF_UP | RTF_PREF(pref),
1628 };
1629
1630 ipv6_addr_copy(&cfg.fc_dst, prefix);
1631 ipv6_addr_copy(&cfg.fc_gateway, gwaddr);
1632
1633 /* We should treat it as a default route if prefix length is 0. */
1634 if (!prefixlen)
1635 cfg.fc_flags |= RTF_DEFAULT;
1636
1637 ip6_route_add(&cfg);
1638
1639 return rt6_get_route_info(prefix, prefixlen, gwaddr, ifindex);
1640 }
1641 #endif
1642
1643 struct rt6_info *rt6_get_dflt_router(struct in6_addr *addr, struct net_device *dev)
1644 {
1645 struct rt6_info *rt;
1646 struct fib6_table *table;
1647
1648 table = fib6_get_table(RT6_TABLE_DFLT);
1649 if (table == NULL)
1650 return NULL;
1651
1652 write_lock_bh(&table->tb6_lock);
1653 for (rt = table->tb6_root.leaf; rt; rt=rt->u.dst.rt6_next) {
1654 if (dev == rt->rt6i_dev &&
1655 ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
1656 ipv6_addr_equal(&rt->rt6i_gateway, addr))
1657 break;
1658 }
1659 if (rt)
1660 dst_hold(&rt->u.dst);
1661 write_unlock_bh(&table->tb6_lock);
1662 return rt;
1663 }
1664
1665 EXPORT_SYMBOL(rt6_get_dflt_router);
1666
1667 struct rt6_info *rt6_add_dflt_router(struct in6_addr *gwaddr,
1668 struct net_device *dev,
1669 unsigned int pref)
1670 {
1671 struct fib6_config cfg = {
1672 .fc_table = RT6_TABLE_DFLT,
1673 .fc_metric = IP6_RT_PRIO_USER,
1674 .fc_ifindex = dev->ifindex,
1675 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
1676 RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
1677 };
1678
1679 ipv6_addr_copy(&cfg.fc_gateway, gwaddr);
1680
1681 ip6_route_add(&cfg);
1682
1683 return rt6_get_dflt_router(gwaddr, dev);
1684 }
1685
1686 void rt6_purge_dflt_routers(void)
1687 {
1688 struct rt6_info *rt;
1689 struct fib6_table *table;
1690
1691 /* NOTE: Keep consistent with rt6_get_dflt_router */
1692 table = fib6_get_table(RT6_TABLE_DFLT);
1693 if (table == NULL)
1694 return;
1695
1696 restart:
1697 read_lock_bh(&table->tb6_lock);
1698 for (rt = table->tb6_root.leaf; rt; rt = rt->u.dst.rt6_next) {
1699 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) {
1700 dst_hold(&rt->u.dst);
1701 read_unlock_bh(&table->tb6_lock);
1702 ip6_del_rt(rt);
1703 goto restart;
1704 }
1705 }
1706 read_unlock_bh(&table->tb6_lock);
1707 }
1708
1709 static void rtmsg_to_fib6_config(struct in6_rtmsg *rtmsg,
1710 struct fib6_config *cfg)
1711 {
1712 memset(cfg, 0, sizeof(*cfg));
1713
1714 cfg->fc_table = RT6_TABLE_MAIN;
1715 cfg->fc_ifindex = rtmsg->rtmsg_ifindex;
1716 cfg->fc_metric = rtmsg->rtmsg_metric;
1717 cfg->fc_expires = rtmsg->rtmsg_info;
1718 cfg->fc_dst_len = rtmsg->rtmsg_dst_len;
1719 cfg->fc_src_len = rtmsg->rtmsg_src_len;
1720 cfg->fc_flags = rtmsg->rtmsg_flags;
1721
1722 cfg->fc_nlinfo.nl_net = &init_net;
1723
1724 ipv6_addr_copy(&cfg->fc_dst, &rtmsg->rtmsg_dst);
1725 ipv6_addr_copy(&cfg->fc_src, &rtmsg->rtmsg_src);
1726 ipv6_addr_copy(&cfg->fc_gateway, &rtmsg->rtmsg_gateway);
1727 }
1728
1729 int ipv6_route_ioctl(unsigned int cmd, void __user *arg)
1730 {
1731 struct fib6_config cfg;
1732 struct in6_rtmsg rtmsg;
1733 int err;
1734
1735 switch(cmd) {
1736 case SIOCADDRT: /* Add a route */
1737 case SIOCDELRT: /* Delete a route */
1738 if (!capable(CAP_NET_ADMIN))
1739 return -EPERM;
1740 err = copy_from_user(&rtmsg, arg,
1741 sizeof(struct in6_rtmsg));
1742 if (err)
1743 return -EFAULT;
1744
1745 rtmsg_to_fib6_config(&rtmsg, &cfg);
1746
1747 rtnl_lock();
1748 switch (cmd) {
1749 case SIOCADDRT:
1750 err = ip6_route_add(&cfg);
1751 break;
1752 case SIOCDELRT:
1753 err = ip6_route_del(&cfg);
1754 break;
1755 default:
1756 err = -EINVAL;
1757 }
1758 rtnl_unlock();
1759
1760 return err;
1761 }
1762
1763 return -EINVAL;
1764 }
1765
1766 /*
1767 * Drop the packet on the floor
1768 */
1769
1770 static int ip6_pkt_drop(struct sk_buff *skb, int code, int ipstats_mib_noroutes)
1771 {
1772 int type;
1773 switch (ipstats_mib_noroutes) {
1774 case IPSTATS_MIB_INNOROUTES:
1775 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
1776 if (type == IPV6_ADDR_ANY || type == IPV6_ADDR_RESERVED) {
1777 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INADDRERRORS);
1778 break;
1779 }
1780 /* FALLTHROUGH */
1781 case IPSTATS_MIB_OUTNOROUTES:
1782 IP6_INC_STATS(ip6_dst_idev(skb->dst), ipstats_mib_noroutes);
1783 break;
1784 }
1785 icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0, skb->dev);
1786 kfree_skb(skb);
1787 return 0;
1788 }
1789
1790 static int ip6_pkt_discard(struct sk_buff *skb)
1791 {
1792 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
1793 }
1794
1795 static int ip6_pkt_discard_out(struct sk_buff *skb)
1796 {
1797 skb->dev = skb->dst->dev;
1798 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
1799 }
1800
1801 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1802
1803 static int ip6_pkt_prohibit(struct sk_buff *skb)
1804 {
1805 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
1806 }
1807
1808 static int ip6_pkt_prohibit_out(struct sk_buff *skb)
1809 {
1810 skb->dev = skb->dst->dev;
1811 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
1812 }
1813
1814 #endif
1815
1816 /*
1817 * Allocate a dst for local (unicast / anycast) address.
1818 */
1819
1820 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
1821 const struct in6_addr *addr,
1822 int anycast)
1823 {
1824 struct rt6_info *rt = ip6_dst_alloc();
1825
1826 if (rt == NULL)
1827 return ERR_PTR(-ENOMEM);
1828
1829 dev_hold(init_net.loopback_dev);
1830 in6_dev_hold(idev);
1831
1832 rt->u.dst.flags = DST_HOST;
1833 rt->u.dst.input = ip6_input;
1834 rt->u.dst.output = ip6_output;
1835 rt->rt6i_dev = init_net.loopback_dev;
1836 rt->rt6i_idev = idev;
1837 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev);
1838 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst));
1839 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = -1;
1840 rt->u.dst.obsolete = -1;
1841
1842 rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP;
1843 if (anycast)
1844 rt->rt6i_flags |= RTF_ANYCAST;
1845 else
1846 rt->rt6i_flags |= RTF_LOCAL;
1847 rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway);
1848 if (rt->rt6i_nexthop == NULL) {
1849 dst_free(&rt->u.dst);
1850 return ERR_PTR(-ENOMEM);
1851 }
1852
1853 ipv6_addr_copy(&rt->rt6i_dst.addr, addr);
1854 rt->rt6i_dst.plen = 128;
1855 rt->rt6i_table = fib6_get_table(RT6_TABLE_LOCAL);
1856
1857 atomic_set(&rt->u.dst.__refcnt, 1);
1858
1859 return rt;
1860 }
1861
1862 static int fib6_ifdown(struct rt6_info *rt, void *arg)
1863 {
1864 if (((void*)rt->rt6i_dev == arg || arg == NULL) &&
1865 rt != &ip6_null_entry) {
1866 RT6_TRACE("deleted by ifdown %p\n", rt);
1867 return -1;
1868 }
1869 return 0;
1870 }
1871
1872 void rt6_ifdown(struct net_device *dev)
1873 {
1874 fib6_clean_all(fib6_ifdown, 0, dev);
1875 }
1876
1877 struct rt6_mtu_change_arg
1878 {
1879 struct net_device *dev;
1880 unsigned mtu;
1881 };
1882
1883 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg)
1884 {
1885 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
1886 struct inet6_dev *idev;
1887
1888 /* In IPv6 pmtu discovery is not optional,
1889 so that RTAX_MTU lock cannot disable it.
1890 We still use this lock to block changes
1891 caused by addrconf/ndisc.
1892 */
1893
1894 idev = __in6_dev_get(arg->dev);
1895 if (idev == NULL)
1896 return 0;
1897
1898 /* For administrative MTU increase, there is no way to discover
1899 IPv6 PMTU increase, so PMTU increase should be updated here.
1900 Since RFC 1981 doesn't include administrative MTU increase
1901 update PMTU increase is a MUST. (i.e. jumbo frame)
1902 */
1903 /*
1904 If new MTU is less than route PMTU, this new MTU will be the
1905 lowest MTU in the path, update the route PMTU to reflect PMTU
1906 decreases; if new MTU is greater than route PMTU, and the
1907 old MTU is the lowest MTU in the path, update the route PMTU
1908 to reflect the increase. In this case if the other nodes' MTU
1909 also have the lowest MTU, TOO BIG MESSAGE will be lead to
1910 PMTU discouvery.
1911 */
1912 if (rt->rt6i_dev == arg->dev &&
1913 !dst_metric_locked(&rt->u.dst, RTAX_MTU) &&
1914 (dst_mtu(&rt->u.dst) >= arg->mtu ||
1915 (dst_mtu(&rt->u.dst) < arg->mtu &&
1916 dst_mtu(&rt->u.dst) == idev->cnf.mtu6))) {
1917 rt->u.dst.metrics[RTAX_MTU-1] = arg->mtu;
1918 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(arg->mtu);
1919 }
1920 return 0;
1921 }
1922
1923 void rt6_mtu_change(struct net_device *dev, unsigned mtu)
1924 {
1925 struct rt6_mtu_change_arg arg = {
1926 .dev = dev,
1927 .mtu = mtu,
1928 };
1929
1930 fib6_clean_all(rt6_mtu_change_route, 0, &arg);
1931 }
1932
1933 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
1934 [RTA_GATEWAY] = { .len = sizeof(struct in6_addr) },
1935 [RTA_OIF] = { .type = NLA_U32 },
1936 [RTA_IIF] = { .type = NLA_U32 },
1937 [RTA_PRIORITY] = { .type = NLA_U32 },
1938 [RTA_METRICS] = { .type = NLA_NESTED },
1939 };
1940
1941 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
1942 struct fib6_config *cfg)
1943 {
1944 struct rtmsg *rtm;
1945 struct nlattr *tb[RTA_MAX+1];
1946 int err;
1947
1948 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
1949 if (err < 0)
1950 goto errout;
1951
1952 err = -EINVAL;
1953 rtm = nlmsg_data(nlh);
1954 memset(cfg, 0, sizeof(*cfg));
1955
1956 cfg->fc_table = rtm->rtm_table;
1957 cfg->fc_dst_len = rtm->rtm_dst_len;
1958 cfg->fc_src_len = rtm->rtm_src_len;
1959 cfg->fc_flags = RTF_UP;
1960 cfg->fc_protocol = rtm->rtm_protocol;
1961
1962 if (rtm->rtm_type == RTN_UNREACHABLE)
1963 cfg->fc_flags |= RTF_REJECT;
1964
1965 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
1966 cfg->fc_nlinfo.nlh = nlh;
1967 cfg->fc_nlinfo.nl_net = skb->sk->sk_net;
1968
1969 if (tb[RTA_GATEWAY]) {
1970 nla_memcpy(&cfg->fc_gateway, tb[RTA_GATEWAY], 16);
1971 cfg->fc_flags |= RTF_GATEWAY;
1972 }
1973
1974 if (tb[RTA_DST]) {
1975 int plen = (rtm->rtm_dst_len + 7) >> 3;
1976
1977 if (nla_len(tb[RTA_DST]) < plen)
1978 goto errout;
1979
1980 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
1981 }
1982
1983 if (tb[RTA_SRC]) {
1984 int plen = (rtm->rtm_src_len + 7) >> 3;
1985
1986 if (nla_len(tb[RTA_SRC]) < plen)
1987 goto errout;
1988
1989 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
1990 }
1991
1992 if (tb[RTA_OIF])
1993 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
1994
1995 if (tb[RTA_PRIORITY])
1996 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
1997
1998 if (tb[RTA_METRICS]) {
1999 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
2000 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
2001 }
2002
2003 if (tb[RTA_TABLE])
2004 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
2005
2006 err = 0;
2007 errout:
2008 return err;
2009 }
2010
2011 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
2012 {
2013 struct net *net = skb->sk->sk_net;
2014 struct fib6_config cfg;
2015 int err;
2016
2017 if (net != &init_net)
2018 return -EINVAL;
2019
2020 err = rtm_to_fib6_config(skb, nlh, &cfg);
2021 if (err < 0)
2022 return err;
2023
2024 return ip6_route_del(&cfg);
2025 }
2026
2027 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
2028 {
2029 struct net *net = skb->sk->sk_net;
2030 struct fib6_config cfg;
2031 int err;
2032
2033 if (net != &init_net)
2034 return -EINVAL;
2035
2036 err = rtm_to_fib6_config(skb, nlh, &cfg);
2037 if (err < 0)
2038 return err;
2039
2040 return ip6_route_add(&cfg);
2041 }
2042
2043 static inline size_t rt6_nlmsg_size(void)
2044 {
2045 return NLMSG_ALIGN(sizeof(struct rtmsg))
2046 + nla_total_size(16) /* RTA_SRC */
2047 + nla_total_size(16) /* RTA_DST */
2048 + nla_total_size(16) /* RTA_GATEWAY */
2049 + nla_total_size(16) /* RTA_PREFSRC */
2050 + nla_total_size(4) /* RTA_TABLE */
2051 + nla_total_size(4) /* RTA_IIF */
2052 + nla_total_size(4) /* RTA_OIF */
2053 + nla_total_size(4) /* RTA_PRIORITY */
2054 + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
2055 + nla_total_size(sizeof(struct rta_cacheinfo));
2056 }
2057
2058 static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
2059 struct in6_addr *dst, struct in6_addr *src,
2060 int iif, int type, u32 pid, u32 seq,
2061 int prefix, unsigned int flags)
2062 {
2063 struct rtmsg *rtm;
2064 struct nlmsghdr *nlh;
2065 long expires;
2066 u32 table;
2067
2068 if (prefix) { /* user wants prefix routes only */
2069 if (!(rt->rt6i_flags & RTF_PREFIX_RT)) {
2070 /* success since this is not a prefix route */
2071 return 1;
2072 }
2073 }
2074
2075 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtm), flags);
2076 if (nlh == NULL)
2077 return -EMSGSIZE;
2078
2079 rtm = nlmsg_data(nlh);
2080 rtm->rtm_family = AF_INET6;
2081 rtm->rtm_dst_len = rt->rt6i_dst.plen;
2082 rtm->rtm_src_len = rt->rt6i_src.plen;
2083 rtm->rtm_tos = 0;
2084 if (rt->rt6i_table)
2085 table = rt->rt6i_table->tb6_id;
2086 else
2087 table = RT6_TABLE_UNSPEC;
2088 rtm->rtm_table = table;
2089 NLA_PUT_U32(skb, RTA_TABLE, table);
2090 if (rt->rt6i_flags&RTF_REJECT)
2091 rtm->rtm_type = RTN_UNREACHABLE;
2092 else if (rt->rt6i_dev && (rt->rt6i_dev->flags&IFF_LOOPBACK))
2093 rtm->rtm_type = RTN_LOCAL;
2094 else
2095 rtm->rtm_type = RTN_UNICAST;
2096 rtm->rtm_flags = 0;
2097 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
2098 rtm->rtm_protocol = rt->rt6i_protocol;
2099 if (rt->rt6i_flags&RTF_DYNAMIC)
2100 rtm->rtm_protocol = RTPROT_REDIRECT;
2101 else if (rt->rt6i_flags & RTF_ADDRCONF)
2102 rtm->rtm_protocol = RTPROT_KERNEL;
2103 else if (rt->rt6i_flags&RTF_DEFAULT)
2104 rtm->rtm_protocol = RTPROT_RA;
2105
2106 if (rt->rt6i_flags&RTF_CACHE)
2107 rtm->rtm_flags |= RTM_F_CLONED;
2108
2109 if (dst) {
2110 NLA_PUT(skb, RTA_DST, 16, dst);
2111 rtm->rtm_dst_len = 128;
2112 } else if (rtm->rtm_dst_len)
2113 NLA_PUT(skb, RTA_DST, 16, &rt->rt6i_dst.addr);
2114 #ifdef CONFIG_IPV6_SUBTREES
2115 if (src) {
2116 NLA_PUT(skb, RTA_SRC, 16, src);
2117 rtm->rtm_src_len = 128;
2118 } else if (rtm->rtm_src_len)
2119 NLA_PUT(skb, RTA_SRC, 16, &rt->rt6i_src.addr);
2120 #endif
2121 if (iif)
2122 NLA_PUT_U32(skb, RTA_IIF, iif);
2123 else if (dst) {
2124 struct in6_addr saddr_buf;
2125 if (ipv6_get_saddr(&rt->u.dst, dst, &saddr_buf) == 0)
2126 NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);
2127 }
2128
2129 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2130 goto nla_put_failure;
2131
2132 if (rt->u.dst.neighbour)
2133 NLA_PUT(skb, RTA_GATEWAY, 16, &rt->u.dst.neighbour->primary_key);
2134
2135 if (rt->u.dst.dev)
2136 NLA_PUT_U32(skb, RTA_OIF, rt->rt6i_dev->ifindex);
2137
2138 NLA_PUT_U32(skb, RTA_PRIORITY, rt->rt6i_metric);
2139
2140 expires = rt->rt6i_expires ? rt->rt6i_expires - jiffies : 0;
2141 if (rtnl_put_cacheinfo(skb, &rt->u.dst, 0, 0, 0,
2142 expires, rt->u.dst.error) < 0)
2143 goto nla_put_failure;
2144
2145 return nlmsg_end(skb, nlh);
2146
2147 nla_put_failure:
2148 nlmsg_cancel(skb, nlh);
2149 return -EMSGSIZE;
2150 }
2151
2152 int rt6_dump_route(struct rt6_info *rt, void *p_arg)
2153 {
2154 struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
2155 int prefix;
2156
2157 if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) {
2158 struct rtmsg *rtm = nlmsg_data(arg->cb->nlh);
2159 prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0;
2160 } else
2161 prefix = 0;
2162
2163 return rt6_fill_node(arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
2164 NETLINK_CB(arg->cb->skb).pid, arg->cb->nlh->nlmsg_seq,
2165 prefix, NLM_F_MULTI);
2166 }
2167
2168 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2169 {
2170 struct net *net = in_skb->sk->sk_net;
2171 struct nlattr *tb[RTA_MAX+1];
2172 struct rt6_info *rt;
2173 struct sk_buff *skb;
2174 struct rtmsg *rtm;
2175 struct flowi fl;
2176 int err, iif = 0;
2177
2178 if (net != &init_net)
2179 return -EINVAL;
2180
2181 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
2182 if (err < 0)
2183 goto errout;
2184
2185 err = -EINVAL;
2186 memset(&fl, 0, sizeof(fl));
2187
2188 if (tb[RTA_SRC]) {
2189 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
2190 goto errout;
2191
2192 ipv6_addr_copy(&fl.fl6_src, nla_data(tb[RTA_SRC]));
2193 }
2194
2195 if (tb[RTA_DST]) {
2196 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
2197 goto errout;
2198
2199 ipv6_addr_copy(&fl.fl6_dst, nla_data(tb[RTA_DST]));
2200 }
2201
2202 if (tb[RTA_IIF])
2203 iif = nla_get_u32(tb[RTA_IIF]);
2204
2205 if (tb[RTA_OIF])
2206 fl.oif = nla_get_u32(tb[RTA_OIF]);
2207
2208 if (iif) {
2209 struct net_device *dev;
2210 dev = __dev_get_by_index(&init_net, iif);
2211 if (!dev) {
2212 err = -ENODEV;
2213 goto errout;
2214 }
2215 }
2216
2217 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2218 if (skb == NULL) {
2219 err = -ENOBUFS;
2220 goto errout;
2221 }
2222
2223 /* Reserve room for dummy headers, this skb can pass
2224 through good chunk of routing engine.
2225 */
2226 skb_reset_mac_header(skb);
2227 skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr));
2228
2229 rt = (struct rt6_info*) ip6_route_output(NULL, &fl);
2230 skb->dst = &rt->u.dst;
2231
2232 err = rt6_fill_node(skb, rt, &fl.fl6_dst, &fl.fl6_src, iif,
2233 RTM_NEWROUTE, NETLINK_CB(in_skb).pid,
2234 nlh->nlmsg_seq, 0, 0);
2235 if (err < 0) {
2236 kfree_skb(skb);
2237 goto errout;
2238 }
2239
2240 err = rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).pid);
2241 errout:
2242 return err;
2243 }
2244
2245 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info)
2246 {
2247 struct sk_buff *skb;
2248 u32 seq;
2249 int err;
2250
2251 err = -ENOBUFS;
2252 seq = info->nlh != NULL ? info->nlh->nlmsg_seq : 0;
2253
2254 skb = nlmsg_new(rt6_nlmsg_size(), gfp_any());
2255 if (skb == NULL)
2256 goto errout;
2257
2258 err = rt6_fill_node(skb, rt, NULL, NULL, 0,
2259 event, info->pid, seq, 0, 0);
2260 if (err < 0) {
2261 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
2262 WARN_ON(err == -EMSGSIZE);
2263 kfree_skb(skb);
2264 goto errout;
2265 }
2266 err = rtnl_notify(skb, &init_net, info->pid,
2267 RTNLGRP_IPV6_ROUTE, info->nlh, gfp_any());
2268 errout:
2269 if (err < 0)
2270 rtnl_set_sk_err(&init_net, RTNLGRP_IPV6_ROUTE, err);
2271 }
2272
2273 /*
2274 * /proc
2275 */
2276
2277 #ifdef CONFIG_PROC_FS
2278
2279 #define RT6_INFO_LEN (32 + 4 + 32 + 4 + 32 + 40 + 5 + 1)
2280
2281 struct rt6_proc_arg
2282 {
2283 char *buffer;
2284 int offset;
2285 int length;
2286 int skip;
2287 int len;
2288 };
2289
2290 static int rt6_info_route(struct rt6_info *rt, void *p_arg)
2291 {
2292 struct seq_file *m = p_arg;
2293
2294 seq_printf(m, NIP6_SEQFMT " %02x ", NIP6(rt->rt6i_dst.addr),
2295 rt->rt6i_dst.plen);
2296
2297 #ifdef CONFIG_IPV6_SUBTREES
2298 seq_printf(m, NIP6_SEQFMT " %02x ", NIP6(rt->rt6i_src.addr),
2299 rt->rt6i_src.plen);
2300 #else
2301 seq_puts(m, "00000000000000000000000000000000 00 ");
2302 #endif
2303
2304 if (rt->rt6i_nexthop) {
2305 seq_printf(m, NIP6_SEQFMT,
2306 NIP6(*((struct in6_addr *)rt->rt6i_nexthop->primary_key)));
2307 } else {
2308 seq_puts(m, "00000000000000000000000000000000");
2309 }
2310 seq_printf(m, " %08x %08x %08x %08x %8s\n",
2311 rt->rt6i_metric, atomic_read(&rt->u.dst.__refcnt),
2312 rt->u.dst.__use, rt->rt6i_flags,
2313 rt->rt6i_dev ? rt->rt6i_dev->name : "");
2314 return 0;
2315 }
2316
2317 static int ipv6_route_show(struct seq_file *m, void *v)
2318 {
2319 fib6_clean_all(rt6_info_route, 0, m);
2320 return 0;
2321 }
2322
2323 static int ipv6_route_open(struct inode *inode, struct file *file)
2324 {
2325 return single_open(file, ipv6_route_show, NULL);
2326 }
2327
2328 static const struct file_operations ipv6_route_proc_fops = {
2329 .owner = THIS_MODULE,
2330 .open = ipv6_route_open,
2331 .read = seq_read,
2332 .llseek = seq_lseek,
2333 .release = single_release,
2334 };
2335
2336 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
2337 {
2338 seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
2339 rt6_stats.fib_nodes, rt6_stats.fib_route_nodes,
2340 rt6_stats.fib_rt_alloc, rt6_stats.fib_rt_entries,
2341 rt6_stats.fib_rt_cache,
2342 atomic_read(&ip6_dst_ops.entries),
2343 rt6_stats.fib_discarded_routes);
2344
2345 return 0;
2346 }
2347
2348 static int rt6_stats_seq_open(struct inode *inode, struct file *file)
2349 {
2350 return single_open(file, rt6_stats_seq_show, NULL);
2351 }
2352
2353 static const struct file_operations rt6_stats_seq_fops = {
2354 .owner = THIS_MODULE,
2355 .open = rt6_stats_seq_open,
2356 .read = seq_read,
2357 .llseek = seq_lseek,
2358 .release = single_release,
2359 };
2360
2361 static int ipv6_route_proc_init(struct net *net)
2362 {
2363 int ret = -ENOMEM;
2364 if (!proc_net_fops_create(net, "ipv6_route",
2365 0, &ipv6_route_proc_fops))
2366 goto out;
2367
2368 if (!proc_net_fops_create(net, "rt6_stats",
2369 S_IRUGO, &rt6_stats_seq_fops))
2370 goto out_ipv6_route;
2371
2372 ret = 0;
2373 out:
2374 return ret;
2375 out_ipv6_route:
2376 proc_net_remove(net, "ipv6_route");
2377 goto out;
2378 }
2379
2380 static void ipv6_route_proc_fini(struct net *net)
2381 {
2382 proc_net_remove(net, "ipv6_route");
2383 proc_net_remove(net, "rt6_stats");
2384 }
2385 #else
2386 static inline int ipv6_route_proc_init(struct net *net)
2387 {
2388 return 0;
2389 }
2390 static inline void ipv6_route_proc_fini(struct net *net)
2391 {
2392 return ;
2393 }
2394 #endif /* CONFIG_PROC_FS */
2395
2396 #ifdef CONFIG_SYSCTL
2397
2398 static
2399 int ipv6_sysctl_rtcache_flush(ctl_table *ctl, int write, struct file * filp,
2400 void __user *buffer, size_t *lenp, loff_t *ppos)
2401 {
2402 int delay = init_net.ipv6.sysctl.flush_delay;
2403 if (write) {
2404 proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
2405 fib6_run_gc(delay <= 0 ? ~0UL : (unsigned long)delay);
2406 return 0;
2407 } else
2408 return -EINVAL;
2409 }
2410
2411 ctl_table ipv6_route_table_template[] = {
2412 {
2413 .procname = "flush",
2414 .data = &init_net.ipv6.sysctl.flush_delay,
2415 .maxlen = sizeof(int),
2416 .mode = 0200,
2417 .proc_handler = &ipv6_sysctl_rtcache_flush
2418 },
2419 {
2420 .ctl_name = NET_IPV6_ROUTE_GC_THRESH,
2421 .procname = "gc_thresh",
2422 .data = &ip6_dst_ops.gc_thresh,
2423 .maxlen = sizeof(int),
2424 .mode = 0644,
2425 .proc_handler = &proc_dointvec,
2426 },
2427 {
2428 .ctl_name = NET_IPV6_ROUTE_MAX_SIZE,
2429 .procname = "max_size",
2430 .data = &init_net.ipv6.sysctl.ip6_rt_max_size,
2431 .maxlen = sizeof(int),
2432 .mode = 0644,
2433 .proc_handler = &proc_dointvec,
2434 },
2435 {
2436 .ctl_name = NET_IPV6_ROUTE_GC_MIN_INTERVAL,
2437 .procname = "gc_min_interval",
2438 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
2439 .maxlen = sizeof(int),
2440 .mode = 0644,
2441 .proc_handler = &proc_dointvec_jiffies,
2442 .strategy = &sysctl_jiffies,
2443 },
2444 {
2445 .ctl_name = NET_IPV6_ROUTE_GC_TIMEOUT,
2446 .procname = "gc_timeout",
2447 .data = &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
2448 .maxlen = sizeof(int),
2449 .mode = 0644,
2450 .proc_handler = &proc_dointvec_jiffies,
2451 .strategy = &sysctl_jiffies,
2452 },
2453 {
2454 .ctl_name = NET_IPV6_ROUTE_GC_INTERVAL,
2455 .procname = "gc_interval",
2456 .data = &init_net.ipv6.sysctl.ip6_rt_gc_interval,
2457 .maxlen = sizeof(int),
2458 .mode = 0644,
2459 .proc_handler = &proc_dointvec_jiffies,
2460 .strategy = &sysctl_jiffies,
2461 },
2462 {
2463 .ctl_name = NET_IPV6_ROUTE_GC_ELASTICITY,
2464 .procname = "gc_elasticity",
2465 .data = &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
2466 .maxlen = sizeof(int),
2467 .mode = 0644,
2468 .proc_handler = &proc_dointvec_jiffies,
2469 .strategy = &sysctl_jiffies,
2470 },
2471 {
2472 .ctl_name = NET_IPV6_ROUTE_MTU_EXPIRES,
2473 .procname = "mtu_expires",
2474 .data = &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
2475 .maxlen = sizeof(int),
2476 .mode = 0644,
2477 .proc_handler = &proc_dointvec_jiffies,
2478 .strategy = &sysctl_jiffies,
2479 },
2480 {
2481 .ctl_name = NET_IPV6_ROUTE_MIN_ADVMSS,
2482 .procname = "min_adv_mss",
2483 .data = &init_net.ipv6.sysctl.ip6_rt_min_advmss,
2484 .maxlen = sizeof(int),
2485 .mode = 0644,
2486 .proc_handler = &proc_dointvec_jiffies,
2487 .strategy = &sysctl_jiffies,
2488 },
2489 {
2490 .ctl_name = NET_IPV6_ROUTE_GC_MIN_INTERVAL_MS,
2491 .procname = "gc_min_interval_ms",
2492 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
2493 .maxlen = sizeof(int),
2494 .mode = 0644,
2495 .proc_handler = &proc_dointvec_ms_jiffies,
2496 .strategy = &sysctl_ms_jiffies,
2497 },
2498 { .ctl_name = 0 }
2499 };
2500
2501 struct ctl_table *ipv6_route_sysctl_init(struct net *net)
2502 {
2503 struct ctl_table *table;
2504
2505 table = kmemdup(ipv6_route_table_template,
2506 sizeof(ipv6_route_table_template),
2507 GFP_KERNEL);
2508 return table;
2509 }
2510 #endif
2511
2512 int __init ip6_route_init(void)
2513 {
2514 int ret;
2515
2516 ip6_dst_ops.kmem_cachep =
2517 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
2518 SLAB_HWCACHE_ALIGN, NULL);
2519 if (!ip6_dst_ops.kmem_cachep)
2520 return -ENOMEM;
2521
2522 ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops.kmem_cachep;
2523
2524 ret = fib6_init();
2525 if (ret)
2526 goto out_kmem_cache;
2527
2528 ret = ipv6_route_proc_init(&init_net);
2529 if (ret)
2530 goto out_fib6_init;
2531
2532 ret = xfrm6_init();
2533 if (ret)
2534 goto out_proc_init;
2535
2536 ret = fib6_rules_init();
2537 if (ret)
2538 goto xfrm6_init;
2539
2540 ret = -ENOBUFS;
2541 if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL) ||
2542 __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL) ||
2543 __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL))
2544 goto fib6_rules_init;
2545
2546 ret = 0;
2547 out:
2548 return ret;
2549
2550 fib6_rules_init:
2551 fib6_rules_cleanup();
2552 xfrm6_init:
2553 xfrm6_fini();
2554 out_proc_init:
2555 ipv6_route_proc_fini(&init_net);
2556 out_fib6_init:
2557 rt6_ifdown(NULL);
2558 fib6_gc_cleanup();
2559 out_kmem_cache:
2560 kmem_cache_destroy(ip6_dst_ops.kmem_cachep);
2561 goto out;
2562 }
2563
2564 void ip6_route_cleanup(void)
2565 {
2566 fib6_rules_cleanup();
2567 ipv6_route_proc_fini(&init_net);
2568 xfrm6_fini();
2569 rt6_ifdown(NULL);
2570 fib6_gc_cleanup();
2571 kmem_cache_destroy(ip6_dst_ops.kmem_cachep);
2572 }
2573
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