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Merge branch 'upstream' into pata-drivers
[mirror_ubuntu-bionic-kernel.git] / net / ipv6 / route.c
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 */
26
27 #include <linux/capability.h>
28 #include <linux/errno.h>
29 #include <linux/types.h>
30 #include <linux/times.h>
31 #include <linux/socket.h>
32 #include <linux/sockios.h>
33 #include <linux/net.h>
34 #include <linux/route.h>
35 #include <linux/netdevice.h>
36 #include <linux/in6.h>
37 #include <linux/init.h>
38 #include <linux/netlink.h>
39 #include <linux/if_arp.h>
40
41 #ifdef CONFIG_PROC_FS
42 #include <linux/proc_fs.h>
43 #include <linux/seq_file.h>
44 #endif
45
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/xfrm.h>
56 #include <net/netevent.h>
57
58 #include <asm/uaccess.h>
59
60 #ifdef CONFIG_SYSCTL
61 #include <linux/sysctl.h>
62 #endif
63
64 /* Set to 3 to get tracing. */
65 #define RT6_DEBUG 2
66
67 #if RT6_DEBUG >= 3
68 #define RDBG(x) printk x
69 #define RT6_TRACE(x...) printk(KERN_DEBUG x)
70 #else
71 #define RDBG(x)
72 #define RT6_TRACE(x...) do { ; } while (0)
73 #endif
74
75 #define CLONE_OFFLINK_ROUTE 0
76
77 #define RT6_SELECT_F_IFACE 0x1
78 #define RT6_SELECT_F_REACHABLE 0x2
79
80 static int ip6_rt_max_size = 4096;
81 static int ip6_rt_gc_min_interval = HZ / 2;
82 static int ip6_rt_gc_timeout = 60*HZ;
83 int ip6_rt_gc_interval = 30*HZ;
84 static int ip6_rt_gc_elasticity = 9;
85 static int ip6_rt_mtu_expires = 10*60*HZ;
86 static int ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
87
88 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort);
89 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie);
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(void);
95
96 static int ip6_pkt_discard(struct sk_buff *skb);
97 static int ip6_pkt_discard_out(struct sk_buff *skb);
98 static void ip6_link_failure(struct sk_buff *skb);
99 static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
100
101 #ifdef CONFIG_IPV6_ROUTE_INFO
102 static struct rt6_info *rt6_add_route_info(struct in6_addr *prefix, int prefixlen,
103 struct in6_addr *gwaddr, int ifindex,
104 unsigned pref);
105 static struct rt6_info *rt6_get_route_info(struct in6_addr *prefix, int prefixlen,
106 struct in6_addr *gwaddr, int ifindex);
107 #endif
108
109 static struct dst_ops ip6_dst_ops = {
110 .family = AF_INET6,
111 .protocol = __constant_htons(ETH_P_IPV6),
112 .gc = ip6_dst_gc,
113 .gc_thresh = 1024,
114 .check = ip6_dst_check,
115 .destroy = ip6_dst_destroy,
116 .ifdown = ip6_dst_ifdown,
117 .negative_advice = ip6_negative_advice,
118 .link_failure = ip6_link_failure,
119 .update_pmtu = ip6_rt_update_pmtu,
120 .entry_size = sizeof(struct rt6_info),
121 };
122
123 struct rt6_info ip6_null_entry = {
124 .u = {
125 .dst = {
126 .__refcnt = ATOMIC_INIT(1),
127 .__use = 1,
128 .dev = &loopback_dev,
129 .obsolete = -1,
130 .error = -ENETUNREACH,
131 .metrics = { [RTAX_HOPLIMIT - 1] = 255, },
132 .input = ip6_pkt_discard,
133 .output = ip6_pkt_discard_out,
134 .ops = &ip6_dst_ops,
135 .path = (struct dst_entry*)&ip6_null_entry,
136 }
137 },
138 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP),
139 .rt6i_metric = ~(u32) 0,
140 .rt6i_ref = ATOMIC_INIT(1),
141 };
142
143 struct fib6_node ip6_routing_table = {
144 .leaf = &ip6_null_entry,
145 .fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO,
146 };
147
148 /* Protects all the ip6 fib */
149
150 DEFINE_RWLOCK(rt6_lock);
151
152
153 /* allocate dst with ip6_dst_ops */
154 static __inline__ struct rt6_info *ip6_dst_alloc(void)
155 {
156 return (struct rt6_info *)dst_alloc(&ip6_dst_ops);
157 }
158
159 static void ip6_dst_destroy(struct dst_entry *dst)
160 {
161 struct rt6_info *rt = (struct rt6_info *)dst;
162 struct inet6_dev *idev = rt->rt6i_idev;
163
164 if (idev != NULL) {
165 rt->rt6i_idev = NULL;
166 in6_dev_put(idev);
167 }
168 }
169
170 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
171 int how)
172 {
173 struct rt6_info *rt = (struct rt6_info *)dst;
174 struct inet6_dev *idev = rt->rt6i_idev;
175
176 if (dev != &loopback_dev && idev != NULL && idev->dev == dev) {
177 struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev);
178 if (loopback_idev != NULL) {
179 rt->rt6i_idev = loopback_idev;
180 in6_dev_put(idev);
181 }
182 }
183 }
184
185 static __inline__ int rt6_check_expired(const struct rt6_info *rt)
186 {
187 return (rt->rt6i_flags & RTF_EXPIRES &&
188 time_after(jiffies, rt->rt6i_expires));
189 }
190
191 /*
192 * Route lookup. Any rt6_lock is implied.
193 */
194
195 static __inline__ struct rt6_info *rt6_device_match(struct rt6_info *rt,
196 int oif,
197 int strict)
198 {
199 struct rt6_info *local = NULL;
200 struct rt6_info *sprt;
201
202 if (oif) {
203 for (sprt = rt; sprt; sprt = sprt->u.next) {
204 struct net_device *dev = sprt->rt6i_dev;
205 if (dev->ifindex == oif)
206 return sprt;
207 if (dev->flags & IFF_LOOPBACK) {
208 if (sprt->rt6i_idev == NULL ||
209 sprt->rt6i_idev->dev->ifindex != oif) {
210 if (strict && oif)
211 continue;
212 if (local && (!oif ||
213 local->rt6i_idev->dev->ifindex == oif))
214 continue;
215 }
216 local = sprt;
217 }
218 }
219
220 if (local)
221 return local;
222
223 if (strict)
224 return &ip6_null_entry;
225 }
226 return rt;
227 }
228
229 #ifdef CONFIG_IPV6_ROUTER_PREF
230 static void rt6_probe(struct rt6_info *rt)
231 {
232 struct neighbour *neigh = rt ? rt->rt6i_nexthop : NULL;
233 /*
234 * Okay, this does not seem to be appropriate
235 * for now, however, we need to check if it
236 * is really so; aka Router Reachability Probing.
237 *
238 * Router Reachability Probe MUST be rate-limited
239 * to no more than one per minute.
240 */
241 if (!neigh || (neigh->nud_state & NUD_VALID))
242 return;
243 read_lock_bh(&neigh->lock);
244 if (!(neigh->nud_state & NUD_VALID) &&
245 time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
246 struct in6_addr mcaddr;
247 struct in6_addr *target;
248
249 neigh->updated = jiffies;
250 read_unlock_bh(&neigh->lock);
251
252 target = (struct in6_addr *)&neigh->primary_key;
253 addrconf_addr_solict_mult(target, &mcaddr);
254 ndisc_send_ns(rt->rt6i_dev, NULL, target, &mcaddr, NULL);
255 } else
256 read_unlock_bh(&neigh->lock);
257 }
258 #else
259 static inline void rt6_probe(struct rt6_info *rt)
260 {
261 return;
262 }
263 #endif
264
265 /*
266 * Default Router Selection (RFC 2461 6.3.6)
267 */
268 static int inline rt6_check_dev(struct rt6_info *rt, int oif)
269 {
270 struct net_device *dev = rt->rt6i_dev;
271 if (!oif || dev->ifindex == oif)
272 return 2;
273 if ((dev->flags & IFF_LOOPBACK) &&
274 rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif)
275 return 1;
276 return 0;
277 }
278
279 static int inline rt6_check_neigh(struct rt6_info *rt)
280 {
281 struct neighbour *neigh = rt->rt6i_nexthop;
282 int m = 0;
283 if (rt->rt6i_flags & RTF_NONEXTHOP ||
284 !(rt->rt6i_flags & RTF_GATEWAY))
285 m = 1;
286 else if (neigh) {
287 read_lock_bh(&neigh->lock);
288 if (neigh->nud_state & NUD_VALID)
289 m = 2;
290 read_unlock_bh(&neigh->lock);
291 }
292 return m;
293 }
294
295 static int rt6_score_route(struct rt6_info *rt, int oif,
296 int strict)
297 {
298 int m, n;
299
300 m = rt6_check_dev(rt, oif);
301 if (!m && (strict & RT6_SELECT_F_IFACE))
302 return -1;
303 #ifdef CONFIG_IPV6_ROUTER_PREF
304 m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2;
305 #endif
306 n = rt6_check_neigh(rt);
307 if (n > 1)
308 m |= 16;
309 else if (!n && strict & RT6_SELECT_F_REACHABLE)
310 return -1;
311 return m;
312 }
313
314 static struct rt6_info *rt6_select(struct rt6_info **head, int oif,
315 int strict)
316 {
317 struct rt6_info *match = NULL, *last = NULL;
318 struct rt6_info *rt, *rt0 = *head;
319 u32 metric;
320 int mpri = -1;
321
322 RT6_TRACE("%s(head=%p(*head=%p), oif=%d)\n",
323 __FUNCTION__, head, head ? *head : NULL, oif);
324
325 for (rt = rt0, metric = rt0->rt6i_metric;
326 rt && rt->rt6i_metric == metric && (!last || rt != rt0);
327 rt = rt->u.next) {
328 int m;
329
330 if (rt6_check_expired(rt))
331 continue;
332
333 last = rt;
334
335 m = rt6_score_route(rt, oif, strict);
336 if (m < 0)
337 continue;
338
339 if (m > mpri) {
340 rt6_probe(match);
341 match = rt;
342 mpri = m;
343 } else {
344 rt6_probe(rt);
345 }
346 }
347
348 if (!match &&
349 (strict & RT6_SELECT_F_REACHABLE) &&
350 last && last != rt0) {
351 /* no entries matched; do round-robin */
352 static DEFINE_SPINLOCK(lock);
353 spin_lock(&lock);
354 *head = rt0->u.next;
355 rt0->u.next = last->u.next;
356 last->u.next = rt0;
357 spin_unlock(&lock);
358 }
359
360 RT6_TRACE("%s() => %p, score=%d\n",
361 __FUNCTION__, match, mpri);
362
363 return (match ? match : &ip6_null_entry);
364 }
365
366 #ifdef CONFIG_IPV6_ROUTE_INFO
367 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
368 struct in6_addr *gwaddr)
369 {
370 struct route_info *rinfo = (struct route_info *) opt;
371 struct in6_addr prefix_buf, *prefix;
372 unsigned int pref;
373 u32 lifetime;
374 struct rt6_info *rt;
375
376 if (len < sizeof(struct route_info)) {
377 return -EINVAL;
378 }
379
380 /* Sanity check for prefix_len and length */
381 if (rinfo->length > 3) {
382 return -EINVAL;
383 } else if (rinfo->prefix_len > 128) {
384 return -EINVAL;
385 } else if (rinfo->prefix_len > 64) {
386 if (rinfo->length < 2) {
387 return -EINVAL;
388 }
389 } else if (rinfo->prefix_len > 0) {
390 if (rinfo->length < 1) {
391 return -EINVAL;
392 }
393 }
394
395 pref = rinfo->route_pref;
396 if (pref == ICMPV6_ROUTER_PREF_INVALID)
397 pref = ICMPV6_ROUTER_PREF_MEDIUM;
398
399 lifetime = htonl(rinfo->lifetime);
400 if (lifetime == 0xffffffff) {
401 /* infinity */
402 } else if (lifetime > 0x7fffffff/HZ) {
403 /* Avoid arithmetic overflow */
404 lifetime = 0x7fffffff/HZ - 1;
405 }
406
407 if (rinfo->length == 3)
408 prefix = (struct in6_addr *)rinfo->prefix;
409 else {
410 /* this function is safe */
411 ipv6_addr_prefix(&prefix_buf,
412 (struct in6_addr *)rinfo->prefix,
413 rinfo->prefix_len);
414 prefix = &prefix_buf;
415 }
416
417 rt = rt6_get_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex);
418
419 if (rt && !lifetime) {
420 ip6_del_rt(rt, NULL, NULL, NULL);
421 rt = NULL;
422 }
423
424 if (!rt && lifetime)
425 rt = rt6_add_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex,
426 pref);
427 else if (rt)
428 rt->rt6i_flags = RTF_ROUTEINFO |
429 (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
430
431 if (rt) {
432 if (lifetime == 0xffffffff) {
433 rt->rt6i_flags &= ~RTF_EXPIRES;
434 } else {
435 rt->rt6i_expires = jiffies + HZ * lifetime;
436 rt->rt6i_flags |= RTF_EXPIRES;
437 }
438 dst_release(&rt->u.dst);
439 }
440 return 0;
441 }
442 #endif
443
444 struct rt6_info *rt6_lookup(struct in6_addr *daddr, struct in6_addr *saddr,
445 int oif, int strict)
446 {
447 struct fib6_node *fn;
448 struct rt6_info *rt;
449
450 read_lock_bh(&rt6_lock);
451 fn = fib6_lookup(&ip6_routing_table, daddr, saddr);
452 rt = rt6_device_match(fn->leaf, oif, strict);
453 dst_hold(&rt->u.dst);
454 rt->u.dst.__use++;
455 read_unlock_bh(&rt6_lock);
456
457 rt->u.dst.lastuse = jiffies;
458 if (rt->u.dst.error == 0)
459 return rt;
460 dst_release(&rt->u.dst);
461 return NULL;
462 }
463
464 /* ip6_ins_rt is called with FREE rt6_lock.
465 It takes new route entry, the addition fails by any reason the
466 route is freed. In any case, if caller does not hold it, it may
467 be destroyed.
468 */
469
470 int ip6_ins_rt(struct rt6_info *rt, struct nlmsghdr *nlh,
471 void *_rtattr, struct netlink_skb_parms *req)
472 {
473 int err;
474
475 write_lock_bh(&rt6_lock);
476 err = fib6_add(&ip6_routing_table, rt, nlh, _rtattr, req);
477 write_unlock_bh(&rt6_lock);
478
479 return err;
480 }
481
482 static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, struct in6_addr *daddr,
483 struct in6_addr *saddr)
484 {
485 struct rt6_info *rt;
486
487 /*
488 * Clone the route.
489 */
490
491 rt = ip6_rt_copy(ort);
492
493 if (rt) {
494 if (!(rt->rt6i_flags&RTF_GATEWAY)) {
495 if (rt->rt6i_dst.plen != 128 &&
496 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr))
497 rt->rt6i_flags |= RTF_ANYCAST;
498 ipv6_addr_copy(&rt->rt6i_gateway, daddr);
499 }
500
501 ipv6_addr_copy(&rt->rt6i_dst.addr, daddr);
502 rt->rt6i_dst.plen = 128;
503 rt->rt6i_flags |= RTF_CACHE;
504 rt->u.dst.flags |= DST_HOST;
505
506 #ifdef CONFIG_IPV6_SUBTREES
507 if (rt->rt6i_src.plen && saddr) {
508 ipv6_addr_copy(&rt->rt6i_src.addr, saddr);
509 rt->rt6i_src.plen = 128;
510 }
511 #endif
512
513 rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway);
514
515 }
516
517 return rt;
518 }
519
520 static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort, struct in6_addr *daddr)
521 {
522 struct rt6_info *rt = ip6_rt_copy(ort);
523 if (rt) {
524 ipv6_addr_copy(&rt->rt6i_dst.addr, daddr);
525 rt->rt6i_dst.plen = 128;
526 rt->rt6i_flags |= RTF_CACHE;
527 if (rt->rt6i_flags & RTF_REJECT)
528 rt->u.dst.error = ort->u.dst.error;
529 rt->u.dst.flags |= DST_HOST;
530 rt->rt6i_nexthop = neigh_clone(ort->rt6i_nexthop);
531 }
532 return rt;
533 }
534
535 #define BACKTRACK() \
536 if (rt == &ip6_null_entry) { \
537 while ((fn = fn->parent) != NULL) { \
538 if (fn->fn_flags & RTN_ROOT) { \
539 goto out; \
540 } \
541 if (fn->fn_flags & RTN_RTINFO) \
542 goto restart; \
543 } \
544 }
545
546
547 void ip6_route_input(struct sk_buff *skb)
548 {
549 struct fib6_node *fn;
550 struct rt6_info *rt, *nrt;
551 int strict;
552 int attempts = 3;
553 int err;
554 int reachable = RT6_SELECT_F_REACHABLE;
555
556 strict = ipv6_addr_type(&skb->nh.ipv6h->daddr) & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL) ? RT6_SELECT_F_IFACE : 0;
557
558 relookup:
559 read_lock_bh(&rt6_lock);
560
561 restart_2:
562 fn = fib6_lookup(&ip6_routing_table, &skb->nh.ipv6h->daddr,
563 &skb->nh.ipv6h->saddr);
564
565 restart:
566 rt = rt6_select(&fn->leaf, skb->dev->ifindex, strict | reachable);
567 BACKTRACK();
568 if (rt == &ip6_null_entry ||
569 rt->rt6i_flags & RTF_CACHE)
570 goto out;
571
572 dst_hold(&rt->u.dst);
573 read_unlock_bh(&rt6_lock);
574
575 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
576 nrt = rt6_alloc_cow(rt, &skb->nh.ipv6h->daddr, &skb->nh.ipv6h->saddr);
577 else {
578 #if CLONE_OFFLINK_ROUTE
579 nrt = rt6_alloc_clone(rt, &skb->nh.ipv6h->daddr);
580 #else
581 goto out2;
582 #endif
583 }
584
585 dst_release(&rt->u.dst);
586 rt = nrt ? : &ip6_null_entry;
587
588 dst_hold(&rt->u.dst);
589 if (nrt) {
590 err = ip6_ins_rt(nrt, NULL, NULL, &NETLINK_CB(skb));
591 if (!err)
592 goto out2;
593 }
594
595 if (--attempts <= 0)
596 goto out2;
597
598 /*
599 * Race condition! In the gap, when rt6_lock was
600 * released someone could insert this route. Relookup.
601 */
602 dst_release(&rt->u.dst);
603 goto relookup;
604
605 out:
606 if (reachable) {
607 reachable = 0;
608 goto restart_2;
609 }
610 dst_hold(&rt->u.dst);
611 read_unlock_bh(&rt6_lock);
612 out2:
613 rt->u.dst.lastuse = jiffies;
614 rt->u.dst.__use++;
615 skb->dst = (struct dst_entry *) rt;
616 return;
617 }
618
619 struct dst_entry * ip6_route_output(struct sock *sk, struct flowi *fl)
620 {
621 struct fib6_node *fn;
622 struct rt6_info *rt, *nrt;
623 int strict;
624 int attempts = 3;
625 int err;
626 int reachable = RT6_SELECT_F_REACHABLE;
627
628 strict = ipv6_addr_type(&fl->fl6_dst) & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL) ? RT6_SELECT_F_IFACE : 0;
629
630 relookup:
631 read_lock_bh(&rt6_lock);
632
633 restart_2:
634 fn = fib6_lookup(&ip6_routing_table, &fl->fl6_dst, &fl->fl6_src);
635
636 restart:
637 rt = rt6_select(&fn->leaf, fl->oif, strict | reachable);
638 BACKTRACK();
639 if (rt == &ip6_null_entry ||
640 rt->rt6i_flags & RTF_CACHE)
641 goto out;
642
643 dst_hold(&rt->u.dst);
644 read_unlock_bh(&rt6_lock);
645
646 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
647 nrt = rt6_alloc_cow(rt, &fl->fl6_dst, &fl->fl6_src);
648 else {
649 #if CLONE_OFFLINK_ROUTE
650 nrt = rt6_alloc_clone(rt, &fl->fl6_dst);
651 #else
652 goto out2;
653 #endif
654 }
655
656 dst_release(&rt->u.dst);
657 rt = nrt ? : &ip6_null_entry;
658
659 dst_hold(&rt->u.dst);
660 if (nrt) {
661 err = ip6_ins_rt(nrt, NULL, NULL, NULL);
662 if (!err)
663 goto out2;
664 }
665
666 if (--attempts <= 0)
667 goto out2;
668
669 /*
670 * Race condition! In the gap, when rt6_lock was
671 * released someone could insert this route. Relookup.
672 */
673 dst_release(&rt->u.dst);
674 goto relookup;
675
676 out:
677 if (reachable) {
678 reachable = 0;
679 goto restart_2;
680 }
681 dst_hold(&rt->u.dst);
682 read_unlock_bh(&rt6_lock);
683 out2:
684 rt->u.dst.lastuse = jiffies;
685 rt->u.dst.__use++;
686 return &rt->u.dst;
687 }
688
689
690 /*
691 * Destination cache support functions
692 */
693
694 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
695 {
696 struct rt6_info *rt;
697
698 rt = (struct rt6_info *) dst;
699
700 if (rt && rt->rt6i_node && (rt->rt6i_node->fn_sernum == cookie))
701 return dst;
702
703 return NULL;
704 }
705
706 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
707 {
708 struct rt6_info *rt = (struct rt6_info *) dst;
709
710 if (rt) {
711 if (rt->rt6i_flags & RTF_CACHE)
712 ip6_del_rt(rt, NULL, NULL, NULL);
713 else
714 dst_release(dst);
715 }
716 return NULL;
717 }
718
719 static void ip6_link_failure(struct sk_buff *skb)
720 {
721 struct rt6_info *rt;
722
723 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0, skb->dev);
724
725 rt = (struct rt6_info *) skb->dst;
726 if (rt) {
727 if (rt->rt6i_flags&RTF_CACHE) {
728 dst_set_expires(&rt->u.dst, 0);
729 rt->rt6i_flags |= RTF_EXPIRES;
730 } else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT))
731 rt->rt6i_node->fn_sernum = -1;
732 }
733 }
734
735 static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
736 {
737 struct rt6_info *rt6 = (struct rt6_info*)dst;
738
739 if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) {
740 rt6->rt6i_flags |= RTF_MODIFIED;
741 if (mtu < IPV6_MIN_MTU) {
742 mtu = IPV6_MIN_MTU;
743 dst->metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
744 }
745 dst->metrics[RTAX_MTU-1] = mtu;
746 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
747 }
748 }
749
750 /* Protected by rt6_lock. */
751 static struct dst_entry *ndisc_dst_gc_list;
752 static int ipv6_get_mtu(struct net_device *dev);
753
754 static inline unsigned int ipv6_advmss(unsigned int mtu)
755 {
756 mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
757
758 if (mtu < ip6_rt_min_advmss)
759 mtu = ip6_rt_min_advmss;
760
761 /*
762 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
763 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
764 * IPV6_MAXPLEN is also valid and means: "any MSS,
765 * rely only on pmtu discovery"
766 */
767 if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
768 mtu = IPV6_MAXPLEN;
769 return mtu;
770 }
771
772 struct dst_entry *ndisc_dst_alloc(struct net_device *dev,
773 struct neighbour *neigh,
774 struct in6_addr *addr,
775 int (*output)(struct sk_buff *))
776 {
777 struct rt6_info *rt;
778 struct inet6_dev *idev = in6_dev_get(dev);
779
780 if (unlikely(idev == NULL))
781 return NULL;
782
783 rt = ip6_dst_alloc();
784 if (unlikely(rt == NULL)) {
785 in6_dev_put(idev);
786 goto out;
787 }
788
789 dev_hold(dev);
790 if (neigh)
791 neigh_hold(neigh);
792 else
793 neigh = ndisc_get_neigh(dev, addr);
794
795 rt->rt6i_dev = dev;
796 rt->rt6i_idev = idev;
797 rt->rt6i_nexthop = neigh;
798 atomic_set(&rt->u.dst.__refcnt, 1);
799 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = 255;
800 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev);
801 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst));
802 rt->u.dst.output = output;
803
804 #if 0 /* there's no chance to use these for ndisc */
805 rt->u.dst.flags = ipv6_addr_type(addr) & IPV6_ADDR_UNICAST
806 ? DST_HOST
807 : 0;
808 ipv6_addr_copy(&rt->rt6i_dst.addr, addr);
809 rt->rt6i_dst.plen = 128;
810 #endif
811
812 write_lock_bh(&rt6_lock);
813 rt->u.dst.next = ndisc_dst_gc_list;
814 ndisc_dst_gc_list = &rt->u.dst;
815 write_unlock_bh(&rt6_lock);
816
817 fib6_force_start_gc();
818
819 out:
820 return (struct dst_entry *)rt;
821 }
822
823 int ndisc_dst_gc(int *more)
824 {
825 struct dst_entry *dst, *next, **pprev;
826 int freed;
827
828 next = NULL;
829 pprev = &ndisc_dst_gc_list;
830 freed = 0;
831 while ((dst = *pprev) != NULL) {
832 if (!atomic_read(&dst->__refcnt)) {
833 *pprev = dst->next;
834 dst_free(dst);
835 freed++;
836 } else {
837 pprev = &dst->next;
838 (*more)++;
839 }
840 }
841
842 return freed;
843 }
844
845 static int ip6_dst_gc(void)
846 {
847 static unsigned expire = 30*HZ;
848 static unsigned long last_gc;
849 unsigned long now = jiffies;
850
851 if (time_after(last_gc + ip6_rt_gc_min_interval, now) &&
852 atomic_read(&ip6_dst_ops.entries) <= ip6_rt_max_size)
853 goto out;
854
855 expire++;
856 fib6_run_gc(expire);
857 last_gc = now;
858 if (atomic_read(&ip6_dst_ops.entries) < ip6_dst_ops.gc_thresh)
859 expire = ip6_rt_gc_timeout>>1;
860
861 out:
862 expire -= expire>>ip6_rt_gc_elasticity;
863 return (atomic_read(&ip6_dst_ops.entries) > ip6_rt_max_size);
864 }
865
866 /* Clean host part of a prefix. Not necessary in radix tree,
867 but results in cleaner routing tables.
868
869 Remove it only when all the things will work!
870 */
871
872 static int ipv6_get_mtu(struct net_device *dev)
873 {
874 int mtu = IPV6_MIN_MTU;
875 struct inet6_dev *idev;
876
877 idev = in6_dev_get(dev);
878 if (idev) {
879 mtu = idev->cnf.mtu6;
880 in6_dev_put(idev);
881 }
882 return mtu;
883 }
884
885 int ipv6_get_hoplimit(struct net_device *dev)
886 {
887 int hoplimit = ipv6_devconf.hop_limit;
888 struct inet6_dev *idev;
889
890 idev = in6_dev_get(dev);
891 if (idev) {
892 hoplimit = idev->cnf.hop_limit;
893 in6_dev_put(idev);
894 }
895 return hoplimit;
896 }
897
898 /*
899 *
900 */
901
902 int ip6_route_add(struct in6_rtmsg *rtmsg, struct nlmsghdr *nlh,
903 void *_rtattr, struct netlink_skb_parms *req)
904 {
905 int err;
906 struct rtmsg *r;
907 struct rtattr **rta;
908 struct rt6_info *rt = NULL;
909 struct net_device *dev = NULL;
910 struct inet6_dev *idev = NULL;
911 int addr_type;
912
913 rta = (struct rtattr **) _rtattr;
914
915 if (rtmsg->rtmsg_dst_len > 128 || rtmsg->rtmsg_src_len > 128)
916 return -EINVAL;
917 #ifndef CONFIG_IPV6_SUBTREES
918 if (rtmsg->rtmsg_src_len)
919 return -EINVAL;
920 #endif
921 if (rtmsg->rtmsg_ifindex) {
922 err = -ENODEV;
923 dev = dev_get_by_index(rtmsg->rtmsg_ifindex);
924 if (!dev)
925 goto out;
926 idev = in6_dev_get(dev);
927 if (!idev)
928 goto out;
929 }
930
931 if (rtmsg->rtmsg_metric == 0)
932 rtmsg->rtmsg_metric = IP6_RT_PRIO_USER;
933
934 rt = ip6_dst_alloc();
935
936 if (rt == NULL) {
937 err = -ENOMEM;
938 goto out;
939 }
940
941 rt->u.dst.obsolete = -1;
942 rt->rt6i_expires = jiffies + clock_t_to_jiffies(rtmsg->rtmsg_info);
943 if (nlh && (r = NLMSG_DATA(nlh))) {
944 rt->rt6i_protocol = r->rtm_protocol;
945 } else {
946 rt->rt6i_protocol = RTPROT_BOOT;
947 }
948
949 addr_type = ipv6_addr_type(&rtmsg->rtmsg_dst);
950
951 if (addr_type & IPV6_ADDR_MULTICAST)
952 rt->u.dst.input = ip6_mc_input;
953 else
954 rt->u.dst.input = ip6_forward;
955
956 rt->u.dst.output = ip6_output;
957
958 ipv6_addr_prefix(&rt->rt6i_dst.addr,
959 &rtmsg->rtmsg_dst, rtmsg->rtmsg_dst_len);
960 rt->rt6i_dst.plen = rtmsg->rtmsg_dst_len;
961 if (rt->rt6i_dst.plen == 128)
962 rt->u.dst.flags = DST_HOST;
963
964 #ifdef CONFIG_IPV6_SUBTREES
965 ipv6_addr_prefix(&rt->rt6i_src.addr,
966 &rtmsg->rtmsg_src, rtmsg->rtmsg_src_len);
967 rt->rt6i_src.plen = rtmsg->rtmsg_src_len;
968 #endif
969
970 rt->rt6i_metric = rtmsg->rtmsg_metric;
971
972 /* We cannot add true routes via loopback here,
973 they would result in kernel looping; promote them to reject routes
974 */
975 if ((rtmsg->rtmsg_flags&RTF_REJECT) ||
976 (dev && (dev->flags&IFF_LOOPBACK) && !(addr_type&IPV6_ADDR_LOOPBACK))) {
977 /* hold loopback dev/idev if we haven't done so. */
978 if (dev != &loopback_dev) {
979 if (dev) {
980 dev_put(dev);
981 in6_dev_put(idev);
982 }
983 dev = &loopback_dev;
984 dev_hold(dev);
985 idev = in6_dev_get(dev);
986 if (!idev) {
987 err = -ENODEV;
988 goto out;
989 }
990 }
991 rt->u.dst.output = ip6_pkt_discard_out;
992 rt->u.dst.input = ip6_pkt_discard;
993 rt->u.dst.error = -ENETUNREACH;
994 rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP;
995 goto install_route;
996 }
997
998 if (rtmsg->rtmsg_flags & RTF_GATEWAY) {
999 struct in6_addr *gw_addr;
1000 int gwa_type;
1001
1002 gw_addr = &rtmsg->rtmsg_gateway;
1003 ipv6_addr_copy(&rt->rt6i_gateway, &rtmsg->rtmsg_gateway);
1004 gwa_type = ipv6_addr_type(gw_addr);
1005
1006 if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
1007 struct rt6_info *grt;
1008
1009 /* IPv6 strictly inhibits using not link-local
1010 addresses as nexthop address.
1011 Otherwise, router will not able to send redirects.
1012 It is very good, but in some (rare!) circumstances
1013 (SIT, PtP, NBMA NOARP links) it is handy to allow
1014 some exceptions. --ANK
1015 */
1016 err = -EINVAL;
1017 if (!(gwa_type&IPV6_ADDR_UNICAST))
1018 goto out;
1019
1020 grt = rt6_lookup(gw_addr, NULL, rtmsg->rtmsg_ifindex, 1);
1021
1022 err = -EHOSTUNREACH;
1023 if (grt == NULL)
1024 goto out;
1025 if (dev) {
1026 if (dev != grt->rt6i_dev) {
1027 dst_release(&grt->u.dst);
1028 goto out;
1029 }
1030 } else {
1031 dev = grt->rt6i_dev;
1032 idev = grt->rt6i_idev;
1033 dev_hold(dev);
1034 in6_dev_hold(grt->rt6i_idev);
1035 }
1036 if (!(grt->rt6i_flags&RTF_GATEWAY))
1037 err = 0;
1038 dst_release(&grt->u.dst);
1039
1040 if (err)
1041 goto out;
1042 }
1043 err = -EINVAL;
1044 if (dev == NULL || (dev->flags&IFF_LOOPBACK))
1045 goto out;
1046 }
1047
1048 err = -ENODEV;
1049 if (dev == NULL)
1050 goto out;
1051
1052 if (rtmsg->rtmsg_flags & (RTF_GATEWAY|RTF_NONEXTHOP)) {
1053 rt->rt6i_nexthop = __neigh_lookup_errno(&nd_tbl, &rt->rt6i_gateway, dev);
1054 if (IS_ERR(rt->rt6i_nexthop)) {
1055 err = PTR_ERR(rt->rt6i_nexthop);
1056 rt->rt6i_nexthop = NULL;
1057 goto out;
1058 }
1059 }
1060
1061 rt->rt6i_flags = rtmsg->rtmsg_flags;
1062
1063 install_route:
1064 if (rta && rta[RTA_METRICS-1]) {
1065 int attrlen = RTA_PAYLOAD(rta[RTA_METRICS-1]);
1066 struct rtattr *attr = RTA_DATA(rta[RTA_METRICS-1]);
1067
1068 while (RTA_OK(attr, attrlen)) {
1069 unsigned flavor = attr->rta_type;
1070 if (flavor) {
1071 if (flavor > RTAX_MAX) {
1072 err = -EINVAL;
1073 goto out;
1074 }
1075 rt->u.dst.metrics[flavor-1] =
1076 *(u32 *)RTA_DATA(attr);
1077 }
1078 attr = RTA_NEXT(attr, attrlen);
1079 }
1080 }
1081
1082 if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0)
1083 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = -1;
1084 if (!rt->u.dst.metrics[RTAX_MTU-1])
1085 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(dev);
1086 if (!rt->u.dst.metrics[RTAX_ADVMSS-1])
1087 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst));
1088 rt->u.dst.dev = dev;
1089 rt->rt6i_idev = idev;
1090 return ip6_ins_rt(rt, nlh, _rtattr, req);
1091
1092 out:
1093 if (dev)
1094 dev_put(dev);
1095 if (idev)
1096 in6_dev_put(idev);
1097 if (rt)
1098 dst_free((struct dst_entry *) rt);
1099 return err;
1100 }
1101
1102 int ip6_del_rt(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req)
1103 {
1104 int err;
1105
1106 write_lock_bh(&rt6_lock);
1107
1108 err = fib6_del(rt, nlh, _rtattr, req);
1109 dst_release(&rt->u.dst);
1110
1111 write_unlock_bh(&rt6_lock);
1112
1113 return err;
1114 }
1115
1116 static int ip6_route_del(struct in6_rtmsg *rtmsg, struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req)
1117 {
1118 struct fib6_node *fn;
1119 struct rt6_info *rt;
1120 int err = -ESRCH;
1121
1122 read_lock_bh(&rt6_lock);
1123
1124 fn = fib6_locate(&ip6_routing_table,
1125 &rtmsg->rtmsg_dst, rtmsg->rtmsg_dst_len,
1126 &rtmsg->rtmsg_src, rtmsg->rtmsg_src_len);
1127
1128 if (fn) {
1129 for (rt = fn->leaf; rt; rt = rt->u.next) {
1130 if (rtmsg->rtmsg_ifindex &&
1131 (rt->rt6i_dev == NULL ||
1132 rt->rt6i_dev->ifindex != rtmsg->rtmsg_ifindex))
1133 continue;
1134 if (rtmsg->rtmsg_flags&RTF_GATEWAY &&
1135 !ipv6_addr_equal(&rtmsg->rtmsg_gateway, &rt->rt6i_gateway))
1136 continue;
1137 if (rtmsg->rtmsg_metric &&
1138 rtmsg->rtmsg_metric != rt->rt6i_metric)
1139 continue;
1140 dst_hold(&rt->u.dst);
1141 read_unlock_bh(&rt6_lock);
1142
1143 return ip6_del_rt(rt, nlh, _rtattr, req);
1144 }
1145 }
1146 read_unlock_bh(&rt6_lock);
1147
1148 return err;
1149 }
1150
1151 /*
1152 * Handle redirects
1153 */
1154 void rt6_redirect(struct in6_addr *dest, struct in6_addr *saddr,
1155 struct neighbour *neigh, u8 *lladdr, int on_link)
1156 {
1157 struct rt6_info *rt, *nrt = NULL;
1158 int strict;
1159 struct fib6_node *fn;
1160 struct netevent_redirect netevent;
1161
1162 /*
1163 * Get the "current" route for this destination and
1164 * check if the redirect has come from approriate router.
1165 *
1166 * RFC 2461 specifies that redirects should only be
1167 * accepted if they come from the nexthop to the target.
1168 * Due to the way the routes are chosen, this notion
1169 * is a bit fuzzy and one might need to check all possible
1170 * routes.
1171 */
1172 strict = ipv6_addr_type(dest) & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL);
1173
1174 read_lock_bh(&rt6_lock);
1175 fn = fib6_lookup(&ip6_routing_table, dest, NULL);
1176 restart:
1177 for (rt = fn->leaf; rt; rt = rt->u.next) {
1178 /*
1179 * Current route is on-link; redirect is always invalid.
1180 *
1181 * Seems, previous statement is not true. It could
1182 * be node, which looks for us as on-link (f.e. proxy ndisc)
1183 * But then router serving it might decide, that we should
1184 * know truth 8)8) --ANK (980726).
1185 */
1186 if (rt6_check_expired(rt))
1187 continue;
1188 if (!(rt->rt6i_flags & RTF_GATEWAY))
1189 continue;
1190 if (neigh->dev != rt->rt6i_dev)
1191 continue;
1192 if (!ipv6_addr_equal(saddr, &rt->rt6i_gateway))
1193 continue;
1194 break;
1195 }
1196 if (rt)
1197 dst_hold(&rt->u.dst);
1198 else if (strict) {
1199 while ((fn = fn->parent) != NULL) {
1200 if (fn->fn_flags & RTN_ROOT)
1201 break;
1202 if (fn->fn_flags & RTN_RTINFO)
1203 goto restart;
1204 }
1205 }
1206 read_unlock_bh(&rt6_lock);
1207
1208 if (!rt) {
1209 if (net_ratelimit())
1210 printk(KERN_DEBUG "rt6_redirect: source isn't a valid nexthop "
1211 "for redirect target\n");
1212 return;
1213 }
1214
1215 /*
1216 * We have finally decided to accept it.
1217 */
1218
1219 neigh_update(neigh, lladdr, NUD_STALE,
1220 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1221 NEIGH_UPDATE_F_OVERRIDE|
1222 (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1223 NEIGH_UPDATE_F_ISROUTER))
1224 );
1225
1226 /*
1227 * Redirect received -> path was valid.
1228 * Look, redirects are sent only in response to data packets,
1229 * so that this nexthop apparently is reachable. --ANK
1230 */
1231 dst_confirm(&rt->u.dst);
1232
1233 /* Duplicate redirect: silently ignore. */
1234 if (neigh == rt->u.dst.neighbour)
1235 goto out;
1236
1237 nrt = ip6_rt_copy(rt);
1238 if (nrt == NULL)
1239 goto out;
1240
1241 nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
1242 if (on_link)
1243 nrt->rt6i_flags &= ~RTF_GATEWAY;
1244
1245 ipv6_addr_copy(&nrt->rt6i_dst.addr, dest);
1246 nrt->rt6i_dst.plen = 128;
1247 nrt->u.dst.flags |= DST_HOST;
1248
1249 ipv6_addr_copy(&nrt->rt6i_gateway, (struct in6_addr*)neigh->primary_key);
1250 nrt->rt6i_nexthop = neigh_clone(neigh);
1251 /* Reset pmtu, it may be better */
1252 nrt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(neigh->dev);
1253 nrt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&nrt->u.dst));
1254
1255 if (ip6_ins_rt(nrt, NULL, NULL, NULL))
1256 goto out;
1257
1258 netevent.old = &rt->u.dst;
1259 netevent.new = &nrt->u.dst;
1260 call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
1261
1262 if (rt->rt6i_flags&RTF_CACHE) {
1263 ip6_del_rt(rt, NULL, NULL, NULL);
1264 return;
1265 }
1266
1267 out:
1268 dst_release(&rt->u.dst);
1269 return;
1270 }
1271
1272 /*
1273 * Handle ICMP "packet too big" messages
1274 * i.e. Path MTU discovery
1275 */
1276
1277 void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr,
1278 struct net_device *dev, u32 pmtu)
1279 {
1280 struct rt6_info *rt, *nrt;
1281 int allfrag = 0;
1282
1283 rt = rt6_lookup(daddr, saddr, dev->ifindex, 0);
1284 if (rt == NULL)
1285 return;
1286
1287 if (pmtu >= dst_mtu(&rt->u.dst))
1288 goto out;
1289
1290 if (pmtu < IPV6_MIN_MTU) {
1291 /*
1292 * According to RFC2460, PMTU is set to the IPv6 Minimum Link
1293 * MTU (1280) and a fragment header should always be included
1294 * after a node receiving Too Big message reporting PMTU is
1295 * less than the IPv6 Minimum Link MTU.
1296 */
1297 pmtu = IPV6_MIN_MTU;
1298 allfrag = 1;
1299 }
1300
1301 /* New mtu received -> path was valid.
1302 They are sent only in response to data packets,
1303 so that this nexthop apparently is reachable. --ANK
1304 */
1305 dst_confirm(&rt->u.dst);
1306
1307 /* Host route. If it is static, it would be better
1308 not to override it, but add new one, so that
1309 when cache entry will expire old pmtu
1310 would return automatically.
1311 */
1312 if (rt->rt6i_flags & RTF_CACHE) {
1313 rt->u.dst.metrics[RTAX_MTU-1] = pmtu;
1314 if (allfrag)
1315 rt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
1316 dst_set_expires(&rt->u.dst, ip6_rt_mtu_expires);
1317 rt->rt6i_flags |= RTF_MODIFIED|RTF_EXPIRES;
1318 goto out;
1319 }
1320
1321 /* Network route.
1322 Two cases are possible:
1323 1. It is connected route. Action: COW
1324 2. It is gatewayed route or NONEXTHOP route. Action: clone it.
1325 */
1326 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
1327 nrt = rt6_alloc_cow(rt, daddr, saddr);
1328 else
1329 nrt = rt6_alloc_clone(rt, daddr);
1330
1331 if (nrt) {
1332 nrt->u.dst.metrics[RTAX_MTU-1] = pmtu;
1333 if (allfrag)
1334 nrt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
1335
1336 /* According to RFC 1981, detecting PMTU increase shouldn't be
1337 * happened within 5 mins, the recommended timer is 10 mins.
1338 * Here this route expiration time is set to ip6_rt_mtu_expires
1339 * which is 10 mins. After 10 mins the decreased pmtu is expired
1340 * and detecting PMTU increase will be automatically happened.
1341 */
1342 dst_set_expires(&nrt->u.dst, ip6_rt_mtu_expires);
1343 nrt->rt6i_flags |= RTF_DYNAMIC|RTF_EXPIRES;
1344
1345 ip6_ins_rt(nrt, NULL, NULL, NULL);
1346 }
1347 out:
1348 dst_release(&rt->u.dst);
1349 }
1350
1351 /*
1352 * Misc support functions
1353 */
1354
1355 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort)
1356 {
1357 struct rt6_info *rt = ip6_dst_alloc();
1358
1359 if (rt) {
1360 rt->u.dst.input = ort->u.dst.input;
1361 rt->u.dst.output = ort->u.dst.output;
1362
1363 memcpy(rt->u.dst.metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
1364 rt->u.dst.dev = ort->u.dst.dev;
1365 if (rt->u.dst.dev)
1366 dev_hold(rt->u.dst.dev);
1367 rt->rt6i_idev = ort->rt6i_idev;
1368 if (rt->rt6i_idev)
1369 in6_dev_hold(rt->rt6i_idev);
1370 rt->u.dst.lastuse = jiffies;
1371 rt->rt6i_expires = 0;
1372
1373 ipv6_addr_copy(&rt->rt6i_gateway, &ort->rt6i_gateway);
1374 rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES;
1375 rt->rt6i_metric = 0;
1376
1377 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
1378 #ifdef CONFIG_IPV6_SUBTREES
1379 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
1380 #endif
1381 }
1382 return rt;
1383 }
1384
1385 #ifdef CONFIG_IPV6_ROUTE_INFO
1386 static struct rt6_info *rt6_get_route_info(struct in6_addr *prefix, int prefixlen,
1387 struct in6_addr *gwaddr, int ifindex)
1388 {
1389 struct fib6_node *fn;
1390 struct rt6_info *rt = NULL;
1391
1392 write_lock_bh(&rt6_lock);
1393 fn = fib6_locate(&ip6_routing_table, prefix ,prefixlen, NULL, 0);
1394 if (!fn)
1395 goto out;
1396
1397 for (rt = fn->leaf; rt; rt = rt->u.next) {
1398 if (rt->rt6i_dev->ifindex != ifindex)
1399 continue;
1400 if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
1401 continue;
1402 if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr))
1403 continue;
1404 dst_hold(&rt->u.dst);
1405 break;
1406 }
1407 out:
1408 write_unlock_bh(&rt6_lock);
1409 return rt;
1410 }
1411
1412 static struct rt6_info *rt6_add_route_info(struct in6_addr *prefix, int prefixlen,
1413 struct in6_addr *gwaddr, int ifindex,
1414 unsigned pref)
1415 {
1416 struct in6_rtmsg rtmsg;
1417
1418 memset(&rtmsg, 0, sizeof(rtmsg));
1419 rtmsg.rtmsg_type = RTMSG_NEWROUTE;
1420 ipv6_addr_copy(&rtmsg.rtmsg_dst, prefix);
1421 rtmsg.rtmsg_dst_len = prefixlen;
1422 ipv6_addr_copy(&rtmsg.rtmsg_gateway, gwaddr);
1423 rtmsg.rtmsg_metric = 1024;
1424 rtmsg.rtmsg_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO | RTF_UP | RTF_PREF(pref);
1425 /* We should treat it as a default route if prefix length is 0. */
1426 if (!prefixlen)
1427 rtmsg.rtmsg_flags |= RTF_DEFAULT;
1428 rtmsg.rtmsg_ifindex = ifindex;
1429
1430 ip6_route_add(&rtmsg, NULL, NULL, NULL);
1431
1432 return rt6_get_route_info(prefix, prefixlen, gwaddr, ifindex);
1433 }
1434 #endif
1435
1436 struct rt6_info *rt6_get_dflt_router(struct in6_addr *addr, struct net_device *dev)
1437 {
1438 struct rt6_info *rt;
1439 struct fib6_node *fn;
1440
1441 fn = &ip6_routing_table;
1442
1443 write_lock_bh(&rt6_lock);
1444 for (rt = fn->leaf; rt; rt=rt->u.next) {
1445 if (dev == rt->rt6i_dev &&
1446 ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
1447 ipv6_addr_equal(&rt->rt6i_gateway, addr))
1448 break;
1449 }
1450 if (rt)
1451 dst_hold(&rt->u.dst);
1452 write_unlock_bh(&rt6_lock);
1453 return rt;
1454 }
1455
1456 struct rt6_info *rt6_add_dflt_router(struct in6_addr *gwaddr,
1457 struct net_device *dev,
1458 unsigned int pref)
1459 {
1460 struct in6_rtmsg rtmsg;
1461
1462 memset(&rtmsg, 0, sizeof(struct in6_rtmsg));
1463 rtmsg.rtmsg_type = RTMSG_NEWROUTE;
1464 ipv6_addr_copy(&rtmsg.rtmsg_gateway, gwaddr);
1465 rtmsg.rtmsg_metric = 1024;
1466 rtmsg.rtmsg_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | RTF_UP | RTF_EXPIRES |
1467 RTF_PREF(pref);
1468
1469 rtmsg.rtmsg_ifindex = dev->ifindex;
1470
1471 ip6_route_add(&rtmsg, NULL, NULL, NULL);
1472 return rt6_get_dflt_router(gwaddr, dev);
1473 }
1474
1475 void rt6_purge_dflt_routers(void)
1476 {
1477 struct rt6_info *rt;
1478
1479 restart:
1480 read_lock_bh(&rt6_lock);
1481 for (rt = ip6_routing_table.leaf; rt; rt = rt->u.next) {
1482 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) {
1483 dst_hold(&rt->u.dst);
1484
1485 read_unlock_bh(&rt6_lock);
1486
1487 ip6_del_rt(rt, NULL, NULL, NULL);
1488
1489 goto restart;
1490 }
1491 }
1492 read_unlock_bh(&rt6_lock);
1493 }
1494
1495 int ipv6_route_ioctl(unsigned int cmd, void __user *arg)
1496 {
1497 struct in6_rtmsg rtmsg;
1498 int err;
1499
1500 switch(cmd) {
1501 case SIOCADDRT: /* Add a route */
1502 case SIOCDELRT: /* Delete a route */
1503 if (!capable(CAP_NET_ADMIN))
1504 return -EPERM;
1505 err = copy_from_user(&rtmsg, arg,
1506 sizeof(struct in6_rtmsg));
1507 if (err)
1508 return -EFAULT;
1509
1510 rtnl_lock();
1511 switch (cmd) {
1512 case SIOCADDRT:
1513 err = ip6_route_add(&rtmsg, NULL, NULL, NULL);
1514 break;
1515 case SIOCDELRT:
1516 err = ip6_route_del(&rtmsg, NULL, NULL, NULL);
1517 break;
1518 default:
1519 err = -EINVAL;
1520 }
1521 rtnl_unlock();
1522
1523 return err;
1524 };
1525
1526 return -EINVAL;
1527 }
1528
1529 /*
1530 * Drop the packet on the floor
1531 */
1532
1533 static int ip6_pkt_discard(struct sk_buff *skb)
1534 {
1535 int type = ipv6_addr_type(&skb->nh.ipv6h->daddr);
1536 if (type == IPV6_ADDR_ANY || type == IPV6_ADDR_RESERVED)
1537 IP6_INC_STATS(IPSTATS_MIB_INADDRERRORS);
1538
1539 IP6_INC_STATS(IPSTATS_MIB_OUTNOROUTES);
1540 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_NOROUTE, 0, skb->dev);
1541 kfree_skb(skb);
1542 return 0;
1543 }
1544
1545 static int ip6_pkt_discard_out(struct sk_buff *skb)
1546 {
1547 skb->dev = skb->dst->dev;
1548 return ip6_pkt_discard(skb);
1549 }
1550
1551 /*
1552 * Allocate a dst for local (unicast / anycast) address.
1553 */
1554
1555 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
1556 const struct in6_addr *addr,
1557 int anycast)
1558 {
1559 struct rt6_info *rt = ip6_dst_alloc();
1560
1561 if (rt == NULL)
1562 return ERR_PTR(-ENOMEM);
1563
1564 dev_hold(&loopback_dev);
1565 in6_dev_hold(idev);
1566
1567 rt->u.dst.flags = DST_HOST;
1568 rt->u.dst.input = ip6_input;
1569 rt->u.dst.output = ip6_output;
1570 rt->rt6i_dev = &loopback_dev;
1571 rt->rt6i_idev = idev;
1572 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev);
1573 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst));
1574 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = -1;
1575 rt->u.dst.obsolete = -1;
1576
1577 rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP;
1578 if (anycast)
1579 rt->rt6i_flags |= RTF_ANYCAST;
1580 else
1581 rt->rt6i_flags |= RTF_LOCAL;
1582 rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway);
1583 if (rt->rt6i_nexthop == NULL) {
1584 dst_free((struct dst_entry *) rt);
1585 return ERR_PTR(-ENOMEM);
1586 }
1587
1588 ipv6_addr_copy(&rt->rt6i_dst.addr, addr);
1589 rt->rt6i_dst.plen = 128;
1590
1591 atomic_set(&rt->u.dst.__refcnt, 1);
1592
1593 return rt;
1594 }
1595
1596 static int fib6_ifdown(struct rt6_info *rt, void *arg)
1597 {
1598 if (((void*)rt->rt6i_dev == arg || arg == NULL) &&
1599 rt != &ip6_null_entry) {
1600 RT6_TRACE("deleted by ifdown %p\n", rt);
1601 return -1;
1602 }
1603 return 0;
1604 }
1605
1606 void rt6_ifdown(struct net_device *dev)
1607 {
1608 write_lock_bh(&rt6_lock);
1609 fib6_clean_tree(&ip6_routing_table, fib6_ifdown, 0, dev);
1610 write_unlock_bh(&rt6_lock);
1611 }
1612
1613 struct rt6_mtu_change_arg
1614 {
1615 struct net_device *dev;
1616 unsigned mtu;
1617 };
1618
1619 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg)
1620 {
1621 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
1622 struct inet6_dev *idev;
1623
1624 /* In IPv6 pmtu discovery is not optional,
1625 so that RTAX_MTU lock cannot disable it.
1626 We still use this lock to block changes
1627 caused by addrconf/ndisc.
1628 */
1629
1630 idev = __in6_dev_get(arg->dev);
1631 if (idev == NULL)
1632 return 0;
1633
1634 /* For administrative MTU increase, there is no way to discover
1635 IPv6 PMTU increase, so PMTU increase should be updated here.
1636 Since RFC 1981 doesn't include administrative MTU increase
1637 update PMTU increase is a MUST. (i.e. jumbo frame)
1638 */
1639 /*
1640 If new MTU is less than route PMTU, this new MTU will be the
1641 lowest MTU in the path, update the route PMTU to reflect PMTU
1642 decreases; if new MTU is greater than route PMTU, and the
1643 old MTU is the lowest MTU in the path, update the route PMTU
1644 to reflect the increase. In this case if the other nodes' MTU
1645 also have the lowest MTU, TOO BIG MESSAGE will be lead to
1646 PMTU discouvery.
1647 */
1648 if (rt->rt6i_dev == arg->dev &&
1649 !dst_metric_locked(&rt->u.dst, RTAX_MTU) &&
1650 (dst_mtu(&rt->u.dst) > arg->mtu ||
1651 (dst_mtu(&rt->u.dst) < arg->mtu &&
1652 dst_mtu(&rt->u.dst) == idev->cnf.mtu6)))
1653 rt->u.dst.metrics[RTAX_MTU-1] = arg->mtu;
1654 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(arg->mtu);
1655 return 0;
1656 }
1657
1658 void rt6_mtu_change(struct net_device *dev, unsigned mtu)
1659 {
1660 struct rt6_mtu_change_arg arg;
1661
1662 arg.dev = dev;
1663 arg.mtu = mtu;
1664 read_lock_bh(&rt6_lock);
1665 fib6_clean_tree(&ip6_routing_table, rt6_mtu_change_route, 0, &arg);
1666 read_unlock_bh(&rt6_lock);
1667 }
1668
1669 static int inet6_rtm_to_rtmsg(struct rtmsg *r, struct rtattr **rta,
1670 struct in6_rtmsg *rtmsg)
1671 {
1672 memset(rtmsg, 0, sizeof(*rtmsg));
1673
1674 rtmsg->rtmsg_dst_len = r->rtm_dst_len;
1675 rtmsg->rtmsg_src_len = r->rtm_src_len;
1676 rtmsg->rtmsg_flags = RTF_UP;
1677 if (r->rtm_type == RTN_UNREACHABLE)
1678 rtmsg->rtmsg_flags |= RTF_REJECT;
1679
1680 if (rta[RTA_GATEWAY-1]) {
1681 if (rta[RTA_GATEWAY-1]->rta_len != RTA_LENGTH(16))
1682 return -EINVAL;
1683 memcpy(&rtmsg->rtmsg_gateway, RTA_DATA(rta[RTA_GATEWAY-1]), 16);
1684 rtmsg->rtmsg_flags |= RTF_GATEWAY;
1685 }
1686 if (rta[RTA_DST-1]) {
1687 if (RTA_PAYLOAD(rta[RTA_DST-1]) < ((r->rtm_dst_len+7)>>3))
1688 return -EINVAL;
1689 memcpy(&rtmsg->rtmsg_dst, RTA_DATA(rta[RTA_DST-1]), ((r->rtm_dst_len+7)>>3));
1690 }
1691 if (rta[RTA_SRC-1]) {
1692 if (RTA_PAYLOAD(rta[RTA_SRC-1]) < ((r->rtm_src_len+7)>>3))
1693 return -EINVAL;
1694 memcpy(&rtmsg->rtmsg_src, RTA_DATA(rta[RTA_SRC-1]), ((r->rtm_src_len+7)>>3));
1695 }
1696 if (rta[RTA_OIF-1]) {
1697 if (rta[RTA_OIF-1]->rta_len != RTA_LENGTH(sizeof(int)))
1698 return -EINVAL;
1699 memcpy(&rtmsg->rtmsg_ifindex, RTA_DATA(rta[RTA_OIF-1]), sizeof(int));
1700 }
1701 if (rta[RTA_PRIORITY-1]) {
1702 if (rta[RTA_PRIORITY-1]->rta_len != RTA_LENGTH(4))
1703 return -EINVAL;
1704 memcpy(&rtmsg->rtmsg_metric, RTA_DATA(rta[RTA_PRIORITY-1]), 4);
1705 }
1706 return 0;
1707 }
1708
1709 int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
1710 {
1711 struct rtmsg *r = NLMSG_DATA(nlh);
1712 struct in6_rtmsg rtmsg;
1713
1714 if (inet6_rtm_to_rtmsg(r, arg, &rtmsg))
1715 return -EINVAL;
1716 return ip6_route_del(&rtmsg, nlh, arg, &NETLINK_CB(skb));
1717 }
1718
1719 int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
1720 {
1721 struct rtmsg *r = NLMSG_DATA(nlh);
1722 struct in6_rtmsg rtmsg;
1723
1724 if (inet6_rtm_to_rtmsg(r, arg, &rtmsg))
1725 return -EINVAL;
1726 return ip6_route_add(&rtmsg, nlh, arg, &NETLINK_CB(skb));
1727 }
1728
1729 struct rt6_rtnl_dump_arg
1730 {
1731 struct sk_buff *skb;
1732 struct netlink_callback *cb;
1733 };
1734
1735 static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
1736 struct in6_addr *dst, struct in6_addr *src,
1737 int iif, int type, u32 pid, u32 seq,
1738 int prefix, unsigned int flags)
1739 {
1740 struct rtmsg *rtm;
1741 struct nlmsghdr *nlh;
1742 unsigned char *b = skb->tail;
1743 struct rta_cacheinfo ci;
1744
1745 if (prefix) { /* user wants prefix routes only */
1746 if (!(rt->rt6i_flags & RTF_PREFIX_RT)) {
1747 /* success since this is not a prefix route */
1748 return 1;
1749 }
1750 }
1751
1752 nlh = NLMSG_NEW(skb, pid, seq, type, sizeof(*rtm), flags);
1753 rtm = NLMSG_DATA(nlh);
1754 rtm->rtm_family = AF_INET6;
1755 rtm->rtm_dst_len = rt->rt6i_dst.plen;
1756 rtm->rtm_src_len = rt->rt6i_src.plen;
1757 rtm->rtm_tos = 0;
1758 rtm->rtm_table = RT_TABLE_MAIN;
1759 if (rt->rt6i_flags&RTF_REJECT)
1760 rtm->rtm_type = RTN_UNREACHABLE;
1761 else if (rt->rt6i_dev && (rt->rt6i_dev->flags&IFF_LOOPBACK))
1762 rtm->rtm_type = RTN_LOCAL;
1763 else
1764 rtm->rtm_type = RTN_UNICAST;
1765 rtm->rtm_flags = 0;
1766 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
1767 rtm->rtm_protocol = rt->rt6i_protocol;
1768 if (rt->rt6i_flags&RTF_DYNAMIC)
1769 rtm->rtm_protocol = RTPROT_REDIRECT;
1770 else if (rt->rt6i_flags & RTF_ADDRCONF)
1771 rtm->rtm_protocol = RTPROT_KERNEL;
1772 else if (rt->rt6i_flags&RTF_DEFAULT)
1773 rtm->rtm_protocol = RTPROT_RA;
1774
1775 if (rt->rt6i_flags&RTF_CACHE)
1776 rtm->rtm_flags |= RTM_F_CLONED;
1777
1778 if (dst) {
1779 RTA_PUT(skb, RTA_DST, 16, dst);
1780 rtm->rtm_dst_len = 128;
1781 } else if (rtm->rtm_dst_len)
1782 RTA_PUT(skb, RTA_DST, 16, &rt->rt6i_dst.addr);
1783 #ifdef CONFIG_IPV6_SUBTREES
1784 if (src) {
1785 RTA_PUT(skb, RTA_SRC, 16, src);
1786 rtm->rtm_src_len = 128;
1787 } else if (rtm->rtm_src_len)
1788 RTA_PUT(skb, RTA_SRC, 16, &rt->rt6i_src.addr);
1789 #endif
1790 if (iif)
1791 RTA_PUT(skb, RTA_IIF, 4, &iif);
1792 else if (dst) {
1793 struct in6_addr saddr_buf;
1794 if (ipv6_get_saddr(&rt->u.dst, dst, &saddr_buf) == 0)
1795 RTA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);
1796 }
1797 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
1798 goto rtattr_failure;
1799 if (rt->u.dst.neighbour)
1800 RTA_PUT(skb, RTA_GATEWAY, 16, &rt->u.dst.neighbour->primary_key);
1801 if (rt->u.dst.dev)
1802 RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->rt6i_dev->ifindex);
1803 RTA_PUT(skb, RTA_PRIORITY, 4, &rt->rt6i_metric);
1804 ci.rta_lastuse = jiffies_to_clock_t(jiffies - rt->u.dst.lastuse);
1805 if (rt->rt6i_expires)
1806 ci.rta_expires = jiffies_to_clock_t(rt->rt6i_expires - jiffies);
1807 else
1808 ci.rta_expires = 0;
1809 ci.rta_used = rt->u.dst.__use;
1810 ci.rta_clntref = atomic_read(&rt->u.dst.__refcnt);
1811 ci.rta_error = rt->u.dst.error;
1812 ci.rta_id = 0;
1813 ci.rta_ts = 0;
1814 ci.rta_tsage = 0;
1815 RTA_PUT(skb, RTA_CACHEINFO, sizeof(ci), &ci);
1816 nlh->nlmsg_len = skb->tail - b;
1817 return skb->len;
1818
1819 nlmsg_failure:
1820 rtattr_failure:
1821 skb_trim(skb, b - skb->data);
1822 return -1;
1823 }
1824
1825 static int rt6_dump_route(struct rt6_info *rt, void *p_arg)
1826 {
1827 struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
1828 int prefix;
1829
1830 if (arg->cb->nlh->nlmsg_len >= NLMSG_LENGTH(sizeof(struct rtmsg))) {
1831 struct rtmsg *rtm = NLMSG_DATA(arg->cb->nlh);
1832 prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0;
1833 } else
1834 prefix = 0;
1835
1836 return rt6_fill_node(arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
1837 NETLINK_CB(arg->cb->skb).pid, arg->cb->nlh->nlmsg_seq,
1838 prefix, NLM_F_MULTI);
1839 }
1840
1841 static int fib6_dump_node(struct fib6_walker_t *w)
1842 {
1843 int res;
1844 struct rt6_info *rt;
1845
1846 for (rt = w->leaf; rt; rt = rt->u.next) {
1847 res = rt6_dump_route(rt, w->args);
1848 if (res < 0) {
1849 /* Frame is full, suspend walking */
1850 w->leaf = rt;
1851 return 1;
1852 }
1853 BUG_TRAP(res!=0);
1854 }
1855 w->leaf = NULL;
1856 return 0;
1857 }
1858
1859 static void fib6_dump_end(struct netlink_callback *cb)
1860 {
1861 struct fib6_walker_t *w = (void*)cb->args[0];
1862
1863 if (w) {
1864 cb->args[0] = 0;
1865 fib6_walker_unlink(w);
1866 kfree(w);
1867 }
1868 cb->done = (void*)cb->args[1];
1869 cb->args[1] = 0;
1870 }
1871
1872 static int fib6_dump_done(struct netlink_callback *cb)
1873 {
1874 fib6_dump_end(cb);
1875 return cb->done ? cb->done(cb) : 0;
1876 }
1877
1878 int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
1879 {
1880 struct rt6_rtnl_dump_arg arg;
1881 struct fib6_walker_t *w;
1882 int res;
1883
1884 arg.skb = skb;
1885 arg.cb = cb;
1886
1887 w = (void*)cb->args[0];
1888 if (w == NULL) {
1889 /* New dump:
1890 *
1891 * 1. hook callback destructor.
1892 */
1893 cb->args[1] = (long)cb->done;
1894 cb->done = fib6_dump_done;
1895
1896 /*
1897 * 2. allocate and initialize walker.
1898 */
1899 w = kzalloc(sizeof(*w), GFP_ATOMIC);
1900 if (w == NULL)
1901 return -ENOMEM;
1902 RT6_TRACE("dump<%p", w);
1903 w->root = &ip6_routing_table;
1904 w->func = fib6_dump_node;
1905 w->args = &arg;
1906 cb->args[0] = (long)w;
1907 read_lock_bh(&rt6_lock);
1908 res = fib6_walk(w);
1909 read_unlock_bh(&rt6_lock);
1910 } else {
1911 w->args = &arg;
1912 read_lock_bh(&rt6_lock);
1913 res = fib6_walk_continue(w);
1914 read_unlock_bh(&rt6_lock);
1915 }
1916 #if RT6_DEBUG >= 3
1917 if (res <= 0 && skb->len == 0)
1918 RT6_TRACE("%p>dump end\n", w);
1919 #endif
1920 res = res < 0 ? res : skb->len;
1921 /* res < 0 is an error. (really, impossible)
1922 res == 0 means that dump is complete, but skb still can contain data.
1923 res > 0 dump is not complete, but frame is full.
1924 */
1925 /* Destroy walker, if dump of this table is complete. */
1926 if (res <= 0)
1927 fib6_dump_end(cb);
1928 return res;
1929 }
1930
1931 int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
1932 {
1933 struct rtattr **rta = arg;
1934 int iif = 0;
1935 int err = -ENOBUFS;
1936 struct sk_buff *skb;
1937 struct flowi fl;
1938 struct rt6_info *rt;
1939
1940 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1941 if (skb == NULL)
1942 goto out;
1943
1944 /* Reserve room for dummy headers, this skb can pass
1945 through good chunk of routing engine.
1946 */
1947 skb->mac.raw = skb->data;
1948 skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr));
1949
1950 memset(&fl, 0, sizeof(fl));
1951 if (rta[RTA_SRC-1])
1952 ipv6_addr_copy(&fl.fl6_src,
1953 (struct in6_addr*)RTA_DATA(rta[RTA_SRC-1]));
1954 if (rta[RTA_DST-1])
1955 ipv6_addr_copy(&fl.fl6_dst,
1956 (struct in6_addr*)RTA_DATA(rta[RTA_DST-1]));
1957
1958 if (rta[RTA_IIF-1])
1959 memcpy(&iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
1960
1961 if (iif) {
1962 struct net_device *dev;
1963 dev = __dev_get_by_index(iif);
1964 if (!dev) {
1965 err = -ENODEV;
1966 goto out_free;
1967 }
1968 }
1969
1970 fl.oif = 0;
1971 if (rta[RTA_OIF-1])
1972 memcpy(&fl.oif, RTA_DATA(rta[RTA_OIF-1]), sizeof(int));
1973
1974 rt = (struct rt6_info*)ip6_route_output(NULL, &fl);
1975
1976 skb->dst = &rt->u.dst;
1977
1978 NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid;
1979 err = rt6_fill_node(skb, rt,
1980 &fl.fl6_dst, &fl.fl6_src,
1981 iif,
1982 RTM_NEWROUTE, NETLINK_CB(in_skb).pid,
1983 nlh->nlmsg_seq, 0, 0);
1984 if (err < 0) {
1985 err = -EMSGSIZE;
1986 goto out_free;
1987 }
1988
1989 err = netlink_unicast(rtnl, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
1990 if (err > 0)
1991 err = 0;
1992 out:
1993 return err;
1994 out_free:
1995 kfree_skb(skb);
1996 goto out;
1997 }
1998
1999 void inet6_rt_notify(int event, struct rt6_info *rt, struct nlmsghdr *nlh,
2000 struct netlink_skb_parms *req)
2001 {
2002 struct sk_buff *skb;
2003 int size = NLMSG_SPACE(sizeof(struct rtmsg)+256);
2004 u32 pid = current->pid;
2005 u32 seq = 0;
2006
2007 if (req)
2008 pid = req->pid;
2009 if (nlh)
2010 seq = nlh->nlmsg_seq;
2011
2012 skb = alloc_skb(size, gfp_any());
2013 if (!skb) {
2014 netlink_set_err(rtnl, 0, RTNLGRP_IPV6_ROUTE, ENOBUFS);
2015 return;
2016 }
2017 if (rt6_fill_node(skb, rt, NULL, NULL, 0, event, pid, seq, 0, 0) < 0) {
2018 kfree_skb(skb);
2019 netlink_set_err(rtnl, 0, RTNLGRP_IPV6_ROUTE, EINVAL);
2020 return;
2021 }
2022 NETLINK_CB(skb).dst_group = RTNLGRP_IPV6_ROUTE;
2023 netlink_broadcast(rtnl, skb, 0, RTNLGRP_IPV6_ROUTE, gfp_any());
2024 }
2025
2026 /*
2027 * /proc
2028 */
2029
2030 #ifdef CONFIG_PROC_FS
2031
2032 #define RT6_INFO_LEN (32 + 4 + 32 + 4 + 32 + 40 + 5 + 1)
2033
2034 struct rt6_proc_arg
2035 {
2036 char *buffer;
2037 int offset;
2038 int length;
2039 int skip;
2040 int len;
2041 };
2042
2043 static int rt6_info_route(struct rt6_info *rt, void *p_arg)
2044 {
2045 struct rt6_proc_arg *arg = (struct rt6_proc_arg *) p_arg;
2046 int i;
2047
2048 if (arg->skip < arg->offset / RT6_INFO_LEN) {
2049 arg->skip++;
2050 return 0;
2051 }
2052
2053 if (arg->len >= arg->length)
2054 return 0;
2055
2056 for (i=0; i<16; i++) {
2057 sprintf(arg->buffer + arg->len, "%02x",
2058 rt->rt6i_dst.addr.s6_addr[i]);
2059 arg->len += 2;
2060 }
2061 arg->len += sprintf(arg->buffer + arg->len, " %02x ",
2062 rt->rt6i_dst.plen);
2063
2064 #ifdef CONFIG_IPV6_SUBTREES
2065 for (i=0; i<16; i++) {
2066 sprintf(arg->buffer + arg->len, "%02x",
2067 rt->rt6i_src.addr.s6_addr[i]);
2068 arg->len += 2;
2069 }
2070 arg->len += sprintf(arg->buffer + arg->len, " %02x ",
2071 rt->rt6i_src.plen);
2072 #else
2073 sprintf(arg->buffer + arg->len,
2074 "00000000000000000000000000000000 00 ");
2075 arg->len += 36;
2076 #endif
2077
2078 if (rt->rt6i_nexthop) {
2079 for (i=0; i<16; i++) {
2080 sprintf(arg->buffer + arg->len, "%02x",
2081 rt->rt6i_nexthop->primary_key[i]);
2082 arg->len += 2;
2083 }
2084 } else {
2085 sprintf(arg->buffer + arg->len,
2086 "00000000000000000000000000000000");
2087 arg->len += 32;
2088 }
2089 arg->len += sprintf(arg->buffer + arg->len,
2090 " %08x %08x %08x %08x %8s\n",
2091 rt->rt6i_metric, atomic_read(&rt->u.dst.__refcnt),
2092 rt->u.dst.__use, rt->rt6i_flags,
2093 rt->rt6i_dev ? rt->rt6i_dev->name : "");
2094 return 0;
2095 }
2096
2097 static int rt6_proc_info(char *buffer, char **start, off_t offset, int length)
2098 {
2099 struct rt6_proc_arg arg;
2100 arg.buffer = buffer;
2101 arg.offset = offset;
2102 arg.length = length;
2103 arg.skip = 0;
2104 arg.len = 0;
2105
2106 read_lock_bh(&rt6_lock);
2107 fib6_clean_tree(&ip6_routing_table, rt6_info_route, 0, &arg);
2108 read_unlock_bh(&rt6_lock);
2109
2110 *start = buffer;
2111 if (offset)
2112 *start += offset % RT6_INFO_LEN;
2113
2114 arg.len -= offset % RT6_INFO_LEN;
2115
2116 if (arg.len > length)
2117 arg.len = length;
2118 if (arg.len < 0)
2119 arg.len = 0;
2120
2121 return arg.len;
2122 }
2123
2124 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
2125 {
2126 seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
2127 rt6_stats.fib_nodes, rt6_stats.fib_route_nodes,
2128 rt6_stats.fib_rt_alloc, rt6_stats.fib_rt_entries,
2129 rt6_stats.fib_rt_cache,
2130 atomic_read(&ip6_dst_ops.entries),
2131 rt6_stats.fib_discarded_routes);
2132
2133 return 0;
2134 }
2135
2136 static int rt6_stats_seq_open(struct inode *inode, struct file *file)
2137 {
2138 return single_open(file, rt6_stats_seq_show, NULL);
2139 }
2140
2141 static struct file_operations rt6_stats_seq_fops = {
2142 .owner = THIS_MODULE,
2143 .open = rt6_stats_seq_open,
2144 .read = seq_read,
2145 .llseek = seq_lseek,
2146 .release = single_release,
2147 };
2148 #endif /* CONFIG_PROC_FS */
2149
2150 #ifdef CONFIG_SYSCTL
2151
2152 static int flush_delay;
2153
2154 static
2155 int ipv6_sysctl_rtcache_flush(ctl_table *ctl, int write, struct file * filp,
2156 void __user *buffer, size_t *lenp, loff_t *ppos)
2157 {
2158 if (write) {
2159 proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
2160 fib6_run_gc(flush_delay <= 0 ? ~0UL : (unsigned long)flush_delay);
2161 return 0;
2162 } else
2163 return -EINVAL;
2164 }
2165
2166 ctl_table ipv6_route_table[] = {
2167 {
2168 .ctl_name = NET_IPV6_ROUTE_FLUSH,
2169 .procname = "flush",
2170 .data = &flush_delay,
2171 .maxlen = sizeof(int),
2172 .mode = 0200,
2173 .proc_handler = &ipv6_sysctl_rtcache_flush
2174 },
2175 {
2176 .ctl_name = NET_IPV6_ROUTE_GC_THRESH,
2177 .procname = "gc_thresh",
2178 .data = &ip6_dst_ops.gc_thresh,
2179 .maxlen = sizeof(int),
2180 .mode = 0644,
2181 .proc_handler = &proc_dointvec,
2182 },
2183 {
2184 .ctl_name = NET_IPV6_ROUTE_MAX_SIZE,
2185 .procname = "max_size",
2186 .data = &ip6_rt_max_size,
2187 .maxlen = sizeof(int),
2188 .mode = 0644,
2189 .proc_handler = &proc_dointvec,
2190 },
2191 {
2192 .ctl_name = NET_IPV6_ROUTE_GC_MIN_INTERVAL,
2193 .procname = "gc_min_interval",
2194 .data = &ip6_rt_gc_min_interval,
2195 .maxlen = sizeof(int),
2196 .mode = 0644,
2197 .proc_handler = &proc_dointvec_jiffies,
2198 .strategy = &sysctl_jiffies,
2199 },
2200 {
2201 .ctl_name = NET_IPV6_ROUTE_GC_TIMEOUT,
2202 .procname = "gc_timeout",
2203 .data = &ip6_rt_gc_timeout,
2204 .maxlen = sizeof(int),
2205 .mode = 0644,
2206 .proc_handler = &proc_dointvec_jiffies,
2207 .strategy = &sysctl_jiffies,
2208 },
2209 {
2210 .ctl_name = NET_IPV6_ROUTE_GC_INTERVAL,
2211 .procname = "gc_interval",
2212 .data = &ip6_rt_gc_interval,
2213 .maxlen = sizeof(int),
2214 .mode = 0644,
2215 .proc_handler = &proc_dointvec_jiffies,
2216 .strategy = &sysctl_jiffies,
2217 },
2218 {
2219 .ctl_name = NET_IPV6_ROUTE_GC_ELASTICITY,
2220 .procname = "gc_elasticity",
2221 .data = &ip6_rt_gc_elasticity,
2222 .maxlen = sizeof(int),
2223 .mode = 0644,
2224 .proc_handler = &proc_dointvec_jiffies,
2225 .strategy = &sysctl_jiffies,
2226 },
2227 {
2228 .ctl_name = NET_IPV6_ROUTE_MTU_EXPIRES,
2229 .procname = "mtu_expires",
2230 .data = &ip6_rt_mtu_expires,
2231 .maxlen = sizeof(int),
2232 .mode = 0644,
2233 .proc_handler = &proc_dointvec_jiffies,
2234 .strategy = &sysctl_jiffies,
2235 },
2236 {
2237 .ctl_name = NET_IPV6_ROUTE_MIN_ADVMSS,
2238 .procname = "min_adv_mss",
2239 .data = &ip6_rt_min_advmss,
2240 .maxlen = sizeof(int),
2241 .mode = 0644,
2242 .proc_handler = &proc_dointvec_jiffies,
2243 .strategy = &sysctl_jiffies,
2244 },
2245 {
2246 .ctl_name = NET_IPV6_ROUTE_GC_MIN_INTERVAL_MS,
2247 .procname = "gc_min_interval_ms",
2248 .data = &ip6_rt_gc_min_interval,
2249 .maxlen = sizeof(int),
2250 .mode = 0644,
2251 .proc_handler = &proc_dointvec_ms_jiffies,
2252 .strategy = &sysctl_ms_jiffies,
2253 },
2254 { .ctl_name = 0 }
2255 };
2256
2257 #endif
2258
2259 void __init ip6_route_init(void)
2260 {
2261 struct proc_dir_entry *p;
2262
2263 ip6_dst_ops.kmem_cachep = kmem_cache_create("ip6_dst_cache",
2264 sizeof(struct rt6_info),
2265 0, SLAB_HWCACHE_ALIGN,
2266 NULL, NULL);
2267 if (!ip6_dst_ops.kmem_cachep)
2268 panic("cannot create ip6_dst_cache");
2269
2270 fib6_init();
2271 #ifdef CONFIG_PROC_FS
2272 p = proc_net_create("ipv6_route", 0, rt6_proc_info);
2273 if (p)
2274 p->owner = THIS_MODULE;
2275
2276 proc_net_fops_create("rt6_stats", S_IRUGO, &rt6_stats_seq_fops);
2277 #endif
2278 #ifdef CONFIG_XFRM
2279 xfrm6_init();
2280 #endif
2281 }
2282
2283 void ip6_route_cleanup(void)
2284 {
2285 #ifdef CONFIG_PROC_FS
2286 proc_net_remove("ipv6_route");
2287 proc_net_remove("rt6_stats");
2288 #endif
2289 #ifdef CONFIG_XFRM
2290 xfrm6_fini();
2291 #endif
2292 rt6_ifdown(NULL);
2293 fib6_gc_cleanup();
2294 kmem_cache_destroy(ip6_dst_ops.kmem_cachep);
2295 }
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