[IPSEC]: Add async resume support on input
[linux-2.6] / 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  *      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 int ip6_rt_max_size = 4096;
77 static int ip6_rt_gc_min_interval = HZ / 2;
78 static int ip6_rt_gc_timeout = 60*HZ;
79 int ip6_rt_gc_interval = 30*HZ;
80 static int ip6_rt_gc_elasticity = 9;
81 static int ip6_rt_mtu_expires = 10*60*HZ;
82 static int ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
83
84 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort);
85 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie);
86 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
87 static void             ip6_dst_destroy(struct dst_entry *);
88 static void             ip6_dst_ifdown(struct dst_entry *,
89                                        struct net_device *dev, int how);
90 static int               ip6_dst_gc(void);
91
92 static int              ip6_pkt_discard(struct sk_buff *skb);
93 static int              ip6_pkt_discard_out(struct sk_buff *skb);
94 static void             ip6_link_failure(struct sk_buff *skb);
95 static void             ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
96
97 #ifdef CONFIG_IPV6_ROUTE_INFO
98 static struct rt6_info *rt6_add_route_info(struct in6_addr *prefix, int prefixlen,
99                                            struct in6_addr *gwaddr, int ifindex,
100                                            unsigned pref);
101 static struct rt6_info *rt6_get_route_info(struct in6_addr *prefix, int prefixlen,
102                                            struct in6_addr *gwaddr, int ifindex);
103 #endif
104
105 static struct dst_ops ip6_dst_ops = {
106         .family                 =       AF_INET6,
107         .protocol               =       __constant_htons(ETH_P_IPV6),
108         .gc                     =       ip6_dst_gc,
109         .gc_thresh              =       1024,
110         .check                  =       ip6_dst_check,
111         .destroy                =       ip6_dst_destroy,
112         .ifdown                 =       ip6_dst_ifdown,
113         .negative_advice        =       ip6_negative_advice,
114         .link_failure           =       ip6_link_failure,
115         .update_pmtu            =       ip6_rt_update_pmtu,
116         .local_out              =       ip6_local_out,
117         .entry_size             =       sizeof(struct rt6_info),
118 };
119
120 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
121 {
122 }
123
124 static struct dst_ops ip6_dst_blackhole_ops = {
125         .family                 =       AF_INET6,
126         .protocol               =       __constant_htons(ETH_P_IPV6),
127         .destroy                =       ip6_dst_destroy,
128         .check                  =       ip6_dst_check,
129         .update_pmtu            =       ip6_rt_blackhole_update_pmtu,
130         .entry_size             =       sizeof(struct rt6_info),
131 };
132
133 struct rt6_info ip6_null_entry = {
134         .u = {
135                 .dst = {
136                         .__refcnt       = ATOMIC_INIT(1),
137                         .__use          = 1,
138                         .obsolete       = -1,
139                         .error          = -ENETUNREACH,
140                         .metrics        = { [RTAX_HOPLIMIT - 1] = 255, },
141                         .input          = ip6_pkt_discard,
142                         .output         = ip6_pkt_discard_out,
143                         .ops            = &ip6_dst_ops,
144                         .path           = (struct dst_entry*)&ip6_null_entry,
145                 }
146         },
147         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
148         .rt6i_metric    = ~(u32) 0,
149         .rt6i_ref       = ATOMIC_INIT(1),
150 };
151
152 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
153
154 static int ip6_pkt_prohibit(struct sk_buff *skb);
155 static int ip6_pkt_prohibit_out(struct sk_buff *skb);
156
157 struct rt6_info ip6_prohibit_entry = {
158         .u = {
159                 .dst = {
160                         .__refcnt       = ATOMIC_INIT(1),
161                         .__use          = 1,
162                         .obsolete       = -1,
163                         .error          = -EACCES,
164                         .metrics        = { [RTAX_HOPLIMIT - 1] = 255, },
165                         .input          = ip6_pkt_prohibit,
166                         .output         = ip6_pkt_prohibit_out,
167                         .ops            = &ip6_dst_ops,
168                         .path           = (struct dst_entry*)&ip6_prohibit_entry,
169                 }
170         },
171         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
172         .rt6i_metric    = ~(u32) 0,
173         .rt6i_ref       = ATOMIC_INIT(1),
174 };
175
176 struct rt6_info ip6_blk_hole_entry = {
177         .u = {
178                 .dst = {
179                         .__refcnt       = ATOMIC_INIT(1),
180                         .__use          = 1,
181                         .obsolete       = -1,
182                         .error          = -EINVAL,
183                         .metrics        = { [RTAX_HOPLIMIT - 1] = 255, },
184                         .input          = dst_discard,
185                         .output         = dst_discard,
186                         .ops            = &ip6_dst_ops,
187                         .path           = (struct dst_entry*)&ip6_blk_hole_entry,
188                 }
189         },
190         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
191         .rt6i_metric    = ~(u32) 0,
192         .rt6i_ref       = ATOMIC_INIT(1),
193 };
194
195 #endif
196
197 /* allocate dst with ip6_dst_ops */
198 static __inline__ struct rt6_info *ip6_dst_alloc(void)
199 {
200         return (struct rt6_info *)dst_alloc(&ip6_dst_ops);
201 }
202
203 static void ip6_dst_destroy(struct dst_entry *dst)
204 {
205         struct rt6_info *rt = (struct rt6_info *)dst;
206         struct inet6_dev *idev = rt->rt6i_idev;
207
208         if (idev != NULL) {
209                 rt->rt6i_idev = NULL;
210                 in6_dev_put(idev);
211         }
212 }
213
214 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
215                            int how)
216 {
217         struct rt6_info *rt = (struct rt6_info *)dst;
218         struct inet6_dev *idev = rt->rt6i_idev;
219
220         if (dev != init_net.loopback_dev && idev != NULL && idev->dev == dev) {
221                 struct inet6_dev *loopback_idev = in6_dev_get(init_net.loopback_dev);
222                 if (loopback_idev != NULL) {
223                         rt->rt6i_idev = loopback_idev;
224                         in6_dev_put(idev);
225                 }
226         }
227 }
228
229 static __inline__ int rt6_check_expired(const struct rt6_info *rt)
230 {
231         return (rt->rt6i_flags & RTF_EXPIRES &&
232                 time_after(jiffies, rt->rt6i_expires));
233 }
234
235 static inline int rt6_need_strict(struct in6_addr *daddr)
236 {
237         return (ipv6_addr_type(daddr) &
238                 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
239 }
240
241 /*
242  *      Route lookup. Any table->tb6_lock is implied.
243  */
244
245 static __inline__ struct rt6_info *rt6_device_match(struct rt6_info *rt,
246                                                     int oif,
247                                                     int strict)
248 {
249         struct rt6_info *local = NULL;
250         struct rt6_info *sprt;
251
252         if (oif) {
253                 for (sprt = rt; sprt; sprt = sprt->u.dst.rt6_next) {
254                         struct net_device *dev = sprt->rt6i_dev;
255                         if (dev->ifindex == oif)
256                                 return sprt;
257                         if (dev->flags & IFF_LOOPBACK) {
258                                 if (sprt->rt6i_idev == NULL ||
259                                     sprt->rt6i_idev->dev->ifindex != oif) {
260                                         if (strict && oif)
261                                                 continue;
262                                         if (local && (!oif ||
263                                                       local->rt6i_idev->dev->ifindex == oif))
264                                                 continue;
265                                 }
266                                 local = sprt;
267                         }
268                 }
269
270                 if (local)
271                         return local;
272
273                 if (strict)
274                         return &ip6_null_entry;
275         }
276         return rt;
277 }
278
279 #ifdef CONFIG_IPV6_ROUTER_PREF
280 static void rt6_probe(struct rt6_info *rt)
281 {
282         struct neighbour *neigh = rt ? rt->rt6i_nexthop : NULL;
283         /*
284          * Okay, this does not seem to be appropriate
285          * for now, however, we need to check if it
286          * is really so; aka Router Reachability Probing.
287          *
288          * Router Reachability Probe MUST be rate-limited
289          * to no more than one per minute.
290          */
291         if (!neigh || (neigh->nud_state & NUD_VALID))
292                 return;
293         read_lock_bh(&neigh->lock);
294         if (!(neigh->nud_state & NUD_VALID) &&
295             time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
296                 struct in6_addr mcaddr;
297                 struct in6_addr *target;
298
299                 neigh->updated = jiffies;
300                 read_unlock_bh(&neigh->lock);
301
302                 target = (struct in6_addr *)&neigh->primary_key;
303                 addrconf_addr_solict_mult(target, &mcaddr);
304                 ndisc_send_ns(rt->rt6i_dev, NULL, target, &mcaddr, NULL);
305         } else
306                 read_unlock_bh(&neigh->lock);
307 }
308 #else
309 static inline void rt6_probe(struct rt6_info *rt)
310 {
311         return;
312 }
313 #endif
314
315 /*
316  * Default Router Selection (RFC 2461 6.3.6)
317  */
318 static inline int rt6_check_dev(struct rt6_info *rt, int oif)
319 {
320         struct net_device *dev = rt->rt6i_dev;
321         if (!oif || dev->ifindex == oif)
322                 return 2;
323         if ((dev->flags & IFF_LOOPBACK) &&
324             rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif)
325                 return 1;
326         return 0;
327 }
328
329 static inline int rt6_check_neigh(struct rt6_info *rt)
330 {
331         struct neighbour *neigh = rt->rt6i_nexthop;
332         int m;
333         if (rt->rt6i_flags & RTF_NONEXTHOP ||
334             !(rt->rt6i_flags & RTF_GATEWAY))
335                 m = 1;
336         else if (neigh) {
337                 read_lock_bh(&neigh->lock);
338                 if (neigh->nud_state & NUD_VALID)
339                         m = 2;
340 #ifdef CONFIG_IPV6_ROUTER_PREF
341                 else if (neigh->nud_state & NUD_FAILED)
342                         m = 0;
343 #endif
344                 else
345                         m = 1;
346                 read_unlock_bh(&neigh->lock);
347         } else
348                 m = 0;
349         return m;
350 }
351
352 static int rt6_score_route(struct rt6_info *rt, int oif,
353                            int strict)
354 {
355         int m, n;
356
357         m = rt6_check_dev(rt, oif);
358         if (!m && (strict & RT6_LOOKUP_F_IFACE))
359                 return -1;
360 #ifdef CONFIG_IPV6_ROUTER_PREF
361         m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2;
362 #endif
363         n = rt6_check_neigh(rt);
364         if (!n && (strict & RT6_LOOKUP_F_REACHABLE))
365                 return -1;
366         return m;
367 }
368
369 static struct rt6_info *find_match(struct rt6_info *rt, int oif, int strict,
370                                    int *mpri, struct rt6_info *match)
371 {
372         int m;
373
374         if (rt6_check_expired(rt))
375                 goto out;
376
377         m = rt6_score_route(rt, oif, strict);
378         if (m < 0)
379                 goto out;
380
381         if (m > *mpri) {
382                 if (strict & RT6_LOOKUP_F_REACHABLE)
383                         rt6_probe(match);
384                 *mpri = m;
385                 match = rt;
386         } else if (strict & RT6_LOOKUP_F_REACHABLE) {
387                 rt6_probe(rt);
388         }
389
390 out:
391         return match;
392 }
393
394 static struct rt6_info *find_rr_leaf(struct fib6_node *fn,
395                                      struct rt6_info *rr_head,
396                                      u32 metric, int oif, int strict)
397 {
398         struct rt6_info *rt, *match;
399         int mpri = -1;
400
401         match = NULL;
402         for (rt = rr_head; rt && rt->rt6i_metric == metric;
403              rt = rt->u.dst.rt6_next)
404                 match = find_match(rt, oif, strict, &mpri, match);
405         for (rt = fn->leaf; rt && rt != rr_head && rt->rt6i_metric == metric;
406              rt = rt->u.dst.rt6_next)
407                 match = find_match(rt, oif, strict, &mpri, match);
408
409         return match;
410 }
411
412 static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict)
413 {
414         struct rt6_info *match, *rt0;
415
416         RT6_TRACE("%s(fn->leaf=%p, oif=%d)\n",
417                   __FUNCTION__, fn->leaf, oif);
418
419         rt0 = fn->rr_ptr;
420         if (!rt0)
421                 fn->rr_ptr = rt0 = fn->leaf;
422
423         match = find_rr_leaf(fn, rt0, rt0->rt6i_metric, oif, strict);
424
425         if (!match &&
426             (strict & RT6_LOOKUP_F_REACHABLE)) {
427                 struct rt6_info *next = rt0->u.dst.rt6_next;
428
429                 /* no entries matched; do round-robin */
430                 if (!next || next->rt6i_metric != rt0->rt6i_metric)
431                         next = fn->leaf;
432
433                 if (next != rt0)
434                         fn->rr_ptr = next;
435         }
436
437         RT6_TRACE("%s() => %p\n",
438                   __FUNCTION__, match);
439
440         return (match ? match : &ip6_null_entry);
441 }
442
443 #ifdef CONFIG_IPV6_ROUTE_INFO
444 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
445                   struct in6_addr *gwaddr)
446 {
447         struct route_info *rinfo = (struct route_info *) opt;
448         struct in6_addr prefix_buf, *prefix;
449         unsigned int pref;
450         u32 lifetime;
451         struct rt6_info *rt;
452
453         if (len < sizeof(struct route_info)) {
454                 return -EINVAL;
455         }
456
457         /* Sanity check for prefix_len and length */
458         if (rinfo->length > 3) {
459                 return -EINVAL;
460         } else if (rinfo->prefix_len > 128) {
461                 return -EINVAL;
462         } else if (rinfo->prefix_len > 64) {
463                 if (rinfo->length < 2) {
464                         return -EINVAL;
465                 }
466         } else if (rinfo->prefix_len > 0) {
467                 if (rinfo->length < 1) {
468                         return -EINVAL;
469                 }
470         }
471
472         pref = rinfo->route_pref;
473         if (pref == ICMPV6_ROUTER_PREF_INVALID)
474                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
475
476         lifetime = ntohl(rinfo->lifetime);
477         if (lifetime == 0xffffffff) {
478                 /* infinity */
479         } else if (lifetime > 0x7fffffff/HZ) {
480                 /* Avoid arithmetic overflow */
481                 lifetime = 0x7fffffff/HZ - 1;
482         }
483
484         if (rinfo->length == 3)
485                 prefix = (struct in6_addr *)rinfo->prefix;
486         else {
487                 /* this function is safe */
488                 ipv6_addr_prefix(&prefix_buf,
489                                  (struct in6_addr *)rinfo->prefix,
490                                  rinfo->prefix_len);
491                 prefix = &prefix_buf;
492         }
493
494         rt = rt6_get_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex);
495
496         if (rt && !lifetime) {
497                 ip6_del_rt(rt);
498                 rt = NULL;
499         }
500
501         if (!rt && lifetime)
502                 rt = rt6_add_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex,
503                                         pref);
504         else if (rt)
505                 rt->rt6i_flags = RTF_ROUTEINFO |
506                                  (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
507
508         if (rt) {
509                 if (lifetime == 0xffffffff) {
510                         rt->rt6i_flags &= ~RTF_EXPIRES;
511                 } else {
512                         rt->rt6i_expires = jiffies + HZ * lifetime;
513                         rt->rt6i_flags |= RTF_EXPIRES;
514                 }
515                 dst_release(&rt->u.dst);
516         }
517         return 0;
518 }
519 #endif
520
521 #define BACKTRACK(saddr) \
522 do { \
523         if (rt == &ip6_null_entry) { \
524                 struct fib6_node *pn; \
525                 while (1) { \
526                         if (fn->fn_flags & RTN_TL_ROOT) \
527                                 goto out; \
528                         pn = fn->parent; \
529                         if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn) \
530                                 fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr); \
531                         else \
532                                 fn = pn; \
533                         if (fn->fn_flags & RTN_RTINFO) \
534                                 goto restart; \
535                 } \
536         } \
537 } while(0)
538
539 static struct rt6_info *ip6_pol_route_lookup(struct fib6_table *table,
540                                              struct flowi *fl, int flags)
541 {
542         struct fib6_node *fn;
543         struct rt6_info *rt;
544
545         read_lock_bh(&table->tb6_lock);
546         fn = fib6_lookup(&table->tb6_root, &fl->fl6_dst, &fl->fl6_src);
547 restart:
548         rt = fn->leaf;
549         rt = rt6_device_match(rt, fl->oif, flags);
550         BACKTRACK(&fl->fl6_src);
551 out:
552         dst_use(&rt->u.dst, jiffies);
553         read_unlock_bh(&table->tb6_lock);
554         return rt;
555
556 }
557
558 struct rt6_info *rt6_lookup(struct in6_addr *daddr, struct in6_addr *saddr,
559                             int oif, int strict)
560 {
561         struct flowi fl = {
562                 .oif = oif,
563                 .nl_u = {
564                         .ip6_u = {
565                                 .daddr = *daddr,
566                         },
567                 },
568         };
569         struct dst_entry *dst;
570         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
571
572         if (saddr) {
573                 memcpy(&fl.fl6_src, saddr, sizeof(*saddr));
574                 flags |= RT6_LOOKUP_F_HAS_SADDR;
575         }
576
577         dst = fib6_rule_lookup(&fl, flags, ip6_pol_route_lookup);
578         if (dst->error == 0)
579                 return (struct rt6_info *) dst;
580
581         dst_release(dst);
582
583         return NULL;
584 }
585
586 EXPORT_SYMBOL(rt6_lookup);
587
588 /* ip6_ins_rt is called with FREE table->tb6_lock.
589    It takes new route entry, the addition fails by any reason the
590    route is freed. In any case, if caller does not hold it, it may
591    be destroyed.
592  */
593
594 static int __ip6_ins_rt(struct rt6_info *rt, struct nl_info *info)
595 {
596         int err;
597         struct fib6_table *table;
598
599         table = rt->rt6i_table;
600         write_lock_bh(&table->tb6_lock);
601         err = fib6_add(&table->tb6_root, rt, info);
602         write_unlock_bh(&table->tb6_lock);
603
604         return err;
605 }
606
607 int ip6_ins_rt(struct rt6_info *rt)
608 {
609         return __ip6_ins_rt(rt, NULL);
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 < ip6_rt_min_advmss)
894                 mtu = 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(void)
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 + ip6_rt_gc_min_interval, now) &&
995             atomic_read(&ip6_dst_ops.entries) <= 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 = ip6_rt_gc_timeout>>1;
1003
1004 out:
1005         expire -= expire>>ip6_rt_gc_elasticity;
1006         return (atomic_read(&ip6_dst_ops.entries) > 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         return __ip6_del_rt(rt, NULL);
1267 }
1268
1269 static int ip6_route_del(struct fib6_config *cfg)
1270 {
1271         struct fib6_table *table;
1272         struct fib6_node *fn;
1273         struct rt6_info *rt;
1274         int err = -ESRCH;
1275
1276         table = fib6_get_table(cfg->fc_table);
1277         if (table == NULL)
1278                 return err;
1279
1280         read_lock_bh(&table->tb6_lock);
1281
1282         fn = fib6_locate(&table->tb6_root,
1283                          &cfg->fc_dst, cfg->fc_dst_len,
1284                          &cfg->fc_src, cfg->fc_src_len);
1285
1286         if (fn) {
1287                 for (rt = fn->leaf; rt; rt = rt->u.dst.rt6_next) {
1288                         if (cfg->fc_ifindex &&
1289                             (rt->rt6i_dev == NULL ||
1290                              rt->rt6i_dev->ifindex != cfg->fc_ifindex))
1291                                 continue;
1292                         if (cfg->fc_flags & RTF_GATEWAY &&
1293                             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
1294                                 continue;
1295                         if (cfg->fc_metric && cfg->fc_metric != rt->rt6i_metric)
1296                                 continue;
1297                         dst_hold(&rt->u.dst);
1298                         read_unlock_bh(&table->tb6_lock);
1299
1300                         return __ip6_del_rt(rt, &cfg->fc_nlinfo);
1301                 }
1302         }
1303         read_unlock_bh(&table->tb6_lock);
1304
1305         return err;
1306 }
1307
1308 /*
1309  *      Handle redirects
1310  */
1311 struct ip6rd_flowi {
1312         struct flowi fl;
1313         struct in6_addr gateway;
1314 };
1315
1316 static struct rt6_info *__ip6_route_redirect(struct fib6_table *table,
1317                                              struct flowi *fl,
1318                                              int flags)
1319 {
1320         struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl;
1321         struct rt6_info *rt;
1322         struct fib6_node *fn;
1323
1324         /*
1325          * Get the "current" route for this destination and
1326          * check if the redirect has come from approriate router.
1327          *
1328          * RFC 2461 specifies that redirects should only be
1329          * accepted if they come from the nexthop to the target.
1330          * Due to the way the routes are chosen, this notion
1331          * is a bit fuzzy and one might need to check all possible
1332          * routes.
1333          */
1334
1335         read_lock_bh(&table->tb6_lock);
1336         fn = fib6_lookup(&table->tb6_root, &fl->fl6_dst, &fl->fl6_src);
1337 restart:
1338         for (rt = fn->leaf; rt; rt = rt->u.dst.rt6_next) {
1339                 /*
1340                  * Current route is on-link; redirect is always invalid.
1341                  *
1342                  * Seems, previous statement is not true. It could
1343                  * be node, which looks for us as on-link (f.e. proxy ndisc)
1344                  * But then router serving it might decide, that we should
1345                  * know truth 8)8) --ANK (980726).
1346                  */
1347                 if (rt6_check_expired(rt))
1348                         continue;
1349                 if (!(rt->rt6i_flags & RTF_GATEWAY))
1350                         continue;
1351                 if (fl->oif != rt->rt6i_dev->ifindex)
1352                         continue;
1353                 if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway))
1354                         continue;
1355                 break;
1356         }
1357
1358         if (!rt)
1359                 rt = &ip6_null_entry;
1360         BACKTRACK(&fl->fl6_src);
1361 out:
1362         dst_hold(&rt->u.dst);
1363
1364         read_unlock_bh(&table->tb6_lock);
1365
1366         return rt;
1367 };
1368
1369 static struct rt6_info *ip6_route_redirect(struct in6_addr *dest,
1370                                            struct in6_addr *src,
1371                                            struct in6_addr *gateway,
1372                                            struct net_device *dev)
1373 {
1374         int flags = RT6_LOOKUP_F_HAS_SADDR;
1375         struct ip6rd_flowi rdfl = {
1376                 .fl = {
1377                         .oif = dev->ifindex,
1378                         .nl_u = {
1379                                 .ip6_u = {
1380                                         .daddr = *dest,
1381                                         .saddr = *src,
1382                                 },
1383                         },
1384                 },
1385                 .gateway = *gateway,
1386         };
1387
1388         if (rt6_need_strict(dest))
1389                 flags |= RT6_LOOKUP_F_IFACE;
1390
1391         return (struct rt6_info *)fib6_rule_lookup((struct flowi *)&rdfl, flags, __ip6_route_redirect);
1392 }
1393
1394 void rt6_redirect(struct in6_addr *dest, struct in6_addr *src,
1395                   struct in6_addr *saddr,
1396                   struct neighbour *neigh, u8 *lladdr, int on_link)
1397 {
1398         struct rt6_info *rt, *nrt = NULL;
1399         struct netevent_redirect netevent;
1400
1401         rt = ip6_route_redirect(dest, src, saddr, neigh->dev);
1402
1403         if (rt == &ip6_null_entry) {
1404                 if (net_ratelimit())
1405                         printk(KERN_DEBUG "rt6_redirect: source isn't a valid nexthop "
1406                                "for redirect target\n");
1407                 goto out;
1408         }
1409
1410         /*
1411          *      We have finally decided to accept it.
1412          */
1413
1414         neigh_update(neigh, lladdr, NUD_STALE,
1415                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
1416                      NEIGH_UPDATE_F_OVERRIDE|
1417                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1418                                      NEIGH_UPDATE_F_ISROUTER))
1419                      );
1420
1421         /*
1422          * Redirect received -> path was valid.
1423          * Look, redirects are sent only in response to data packets,
1424          * so that this nexthop apparently is reachable. --ANK
1425          */
1426         dst_confirm(&rt->u.dst);
1427
1428         /* Duplicate redirect: silently ignore. */
1429         if (neigh == rt->u.dst.neighbour)
1430                 goto out;
1431
1432         nrt = ip6_rt_copy(rt);
1433         if (nrt == NULL)
1434                 goto out;
1435
1436         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
1437         if (on_link)
1438                 nrt->rt6i_flags &= ~RTF_GATEWAY;
1439
1440         ipv6_addr_copy(&nrt->rt6i_dst.addr, dest);
1441         nrt->rt6i_dst.plen = 128;
1442         nrt->u.dst.flags |= DST_HOST;
1443
1444         ipv6_addr_copy(&nrt->rt6i_gateway, (struct in6_addr*)neigh->primary_key);
1445         nrt->rt6i_nexthop = neigh_clone(neigh);
1446         /* Reset pmtu, it may be better */
1447         nrt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(neigh->dev);
1448         nrt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&nrt->u.dst));
1449
1450         if (ip6_ins_rt(nrt))
1451                 goto out;
1452
1453         netevent.old = &rt->u.dst;
1454         netevent.new = &nrt->u.dst;
1455         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
1456
1457         if (rt->rt6i_flags&RTF_CACHE) {
1458                 ip6_del_rt(rt);
1459                 return;
1460         }
1461
1462 out:
1463         dst_release(&rt->u.dst);
1464         return;
1465 }
1466
1467 /*
1468  *      Handle ICMP "packet too big" messages
1469  *      i.e. Path MTU discovery
1470  */
1471
1472 void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr,
1473                         struct net_device *dev, u32 pmtu)
1474 {
1475         struct rt6_info *rt, *nrt;
1476         int allfrag = 0;
1477
1478         rt = rt6_lookup(daddr, saddr, dev->ifindex, 0);
1479         if (rt == NULL)
1480                 return;
1481
1482         if (pmtu >= dst_mtu(&rt->u.dst))
1483                 goto out;
1484
1485         if (pmtu < IPV6_MIN_MTU) {
1486                 /*
1487                  * According to RFC2460, PMTU is set to the IPv6 Minimum Link
1488                  * MTU (1280) and a fragment header should always be included
1489                  * after a node receiving Too Big message reporting PMTU is
1490                  * less than the IPv6 Minimum Link MTU.
1491                  */
1492                 pmtu = IPV6_MIN_MTU;
1493                 allfrag = 1;
1494         }
1495
1496         /* New mtu received -> path was valid.
1497            They are sent only in response to data packets,
1498            so that this nexthop apparently is reachable. --ANK
1499          */
1500         dst_confirm(&rt->u.dst);
1501
1502         /* Host route. If it is static, it would be better
1503            not to override it, but add new one, so that
1504            when cache entry will expire old pmtu
1505            would return automatically.
1506          */
1507         if (rt->rt6i_flags & RTF_CACHE) {
1508                 rt->u.dst.metrics[RTAX_MTU-1] = pmtu;
1509                 if (allfrag)
1510                         rt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
1511                 dst_set_expires(&rt->u.dst, ip6_rt_mtu_expires);
1512                 rt->rt6i_flags |= RTF_MODIFIED|RTF_EXPIRES;
1513                 goto out;
1514         }
1515
1516         /* Network route.
1517            Two cases are possible:
1518            1. It is connected route. Action: COW
1519            2. It is gatewayed route or NONEXTHOP route. Action: clone it.
1520          */
1521         if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
1522                 nrt = rt6_alloc_cow(rt, daddr, saddr);
1523         else
1524                 nrt = rt6_alloc_clone(rt, daddr);
1525
1526         if (nrt) {
1527                 nrt->u.dst.metrics[RTAX_MTU-1] = pmtu;
1528                 if (allfrag)
1529                         nrt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
1530
1531                 /* According to RFC 1981, detecting PMTU increase shouldn't be
1532                  * happened within 5 mins, the recommended timer is 10 mins.
1533                  * Here this route expiration time is set to ip6_rt_mtu_expires
1534                  * which is 10 mins. After 10 mins the decreased pmtu is expired
1535                  * and detecting PMTU increase will be automatically happened.
1536                  */
1537                 dst_set_expires(&nrt->u.dst, ip6_rt_mtu_expires);
1538                 nrt->rt6i_flags |= RTF_DYNAMIC|RTF_EXPIRES;
1539
1540                 ip6_ins_rt(nrt);
1541         }
1542 out:
1543         dst_release(&rt->u.dst);
1544 }
1545
1546 /*
1547  *      Misc support functions
1548  */
1549
1550 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort)
1551 {
1552         struct rt6_info *rt = ip6_dst_alloc();
1553
1554         if (rt) {
1555                 rt->u.dst.input = ort->u.dst.input;
1556                 rt->u.dst.output = ort->u.dst.output;
1557
1558                 memcpy(rt->u.dst.metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
1559                 rt->u.dst.error = ort->u.dst.error;
1560                 rt->u.dst.dev = ort->u.dst.dev;
1561                 if (rt->u.dst.dev)
1562                         dev_hold(rt->u.dst.dev);
1563                 rt->rt6i_idev = ort->rt6i_idev;
1564                 if (rt->rt6i_idev)
1565                         in6_dev_hold(rt->rt6i_idev);
1566                 rt->u.dst.lastuse = jiffies;
1567                 rt->rt6i_expires = 0;
1568
1569                 ipv6_addr_copy(&rt->rt6i_gateway, &ort->rt6i_gateway);
1570                 rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES;
1571                 rt->rt6i_metric = 0;
1572
1573                 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
1574 #ifdef CONFIG_IPV6_SUBTREES
1575                 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
1576 #endif
1577                 rt->rt6i_table = ort->rt6i_table;
1578         }
1579         return rt;
1580 }
1581
1582 #ifdef CONFIG_IPV6_ROUTE_INFO
1583 static struct rt6_info *rt6_get_route_info(struct in6_addr *prefix, int prefixlen,
1584                                            struct in6_addr *gwaddr, int ifindex)
1585 {
1586         struct fib6_node *fn;
1587         struct rt6_info *rt = NULL;
1588         struct fib6_table *table;
1589
1590         table = fib6_get_table(RT6_TABLE_INFO);
1591         if (table == NULL)
1592                 return NULL;
1593
1594         write_lock_bh(&table->tb6_lock);
1595         fn = fib6_locate(&table->tb6_root, prefix ,prefixlen, NULL, 0);
1596         if (!fn)
1597                 goto out;
1598
1599         for (rt = fn->leaf; rt; rt = rt->u.dst.rt6_next) {
1600                 if (rt->rt6i_dev->ifindex != ifindex)
1601                         continue;
1602                 if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
1603                         continue;
1604                 if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr))
1605                         continue;
1606                 dst_hold(&rt->u.dst);
1607                 break;
1608         }
1609 out:
1610         write_unlock_bh(&table->tb6_lock);
1611         return rt;
1612 }
1613
1614 static struct rt6_info *rt6_add_route_info(struct in6_addr *prefix, int prefixlen,
1615                                            struct in6_addr *gwaddr, int ifindex,
1616                                            unsigned pref)
1617 {
1618         struct fib6_config cfg = {
1619                 .fc_table       = RT6_TABLE_INFO,
1620                 .fc_metric      = 1024,
1621                 .fc_ifindex     = ifindex,
1622                 .fc_dst_len     = prefixlen,
1623                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
1624                                   RTF_UP | RTF_PREF(pref),
1625         };
1626
1627         ipv6_addr_copy(&cfg.fc_dst, prefix);
1628         ipv6_addr_copy(&cfg.fc_gateway, gwaddr);
1629
1630         /* We should treat it as a default route if prefix length is 0. */
1631         if (!prefixlen)
1632                 cfg.fc_flags |= RTF_DEFAULT;
1633
1634         ip6_route_add(&cfg);
1635
1636         return rt6_get_route_info(prefix, prefixlen, gwaddr, ifindex);
1637 }
1638 #endif
1639
1640 struct rt6_info *rt6_get_dflt_router(struct in6_addr *addr, struct net_device *dev)
1641 {
1642         struct rt6_info *rt;
1643         struct fib6_table *table;
1644
1645         table = fib6_get_table(RT6_TABLE_DFLT);
1646         if (table == NULL)
1647                 return NULL;
1648
1649         write_lock_bh(&table->tb6_lock);
1650         for (rt = table->tb6_root.leaf; rt; rt=rt->u.dst.rt6_next) {
1651                 if (dev == rt->rt6i_dev &&
1652                     ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
1653                     ipv6_addr_equal(&rt->rt6i_gateway, addr))
1654                         break;
1655         }
1656         if (rt)
1657                 dst_hold(&rt->u.dst);
1658         write_unlock_bh(&table->tb6_lock);
1659         return rt;
1660 }
1661
1662 struct rt6_info *rt6_add_dflt_router(struct in6_addr *gwaddr,
1663                                      struct net_device *dev,
1664                                      unsigned int pref)
1665 {
1666         struct fib6_config cfg = {
1667                 .fc_table       = RT6_TABLE_DFLT,
1668                 .fc_metric      = 1024,
1669                 .fc_ifindex     = dev->ifindex,
1670                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
1671                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
1672         };
1673
1674         ipv6_addr_copy(&cfg.fc_gateway, gwaddr);
1675
1676         ip6_route_add(&cfg);
1677
1678         return rt6_get_dflt_router(gwaddr, dev);
1679 }
1680
1681 void rt6_purge_dflt_routers(void)
1682 {
1683         struct rt6_info *rt;
1684         struct fib6_table *table;
1685
1686         /* NOTE: Keep consistent with rt6_get_dflt_router */
1687         table = fib6_get_table(RT6_TABLE_DFLT);
1688         if (table == NULL)
1689                 return;
1690
1691 restart:
1692         read_lock_bh(&table->tb6_lock);
1693         for (rt = table->tb6_root.leaf; rt; rt = rt->u.dst.rt6_next) {
1694                 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) {
1695                         dst_hold(&rt->u.dst);
1696                         read_unlock_bh(&table->tb6_lock);
1697                         ip6_del_rt(rt);
1698                         goto restart;
1699                 }
1700         }
1701         read_unlock_bh(&table->tb6_lock);
1702 }
1703
1704 static void rtmsg_to_fib6_config(struct in6_rtmsg *rtmsg,
1705                                  struct fib6_config *cfg)
1706 {
1707         memset(cfg, 0, sizeof(*cfg));
1708
1709         cfg->fc_table = RT6_TABLE_MAIN;
1710         cfg->fc_ifindex = rtmsg->rtmsg_ifindex;
1711         cfg->fc_metric = rtmsg->rtmsg_metric;
1712         cfg->fc_expires = rtmsg->rtmsg_info;
1713         cfg->fc_dst_len = rtmsg->rtmsg_dst_len;
1714         cfg->fc_src_len = rtmsg->rtmsg_src_len;
1715         cfg->fc_flags = rtmsg->rtmsg_flags;
1716
1717         ipv6_addr_copy(&cfg->fc_dst, &rtmsg->rtmsg_dst);
1718         ipv6_addr_copy(&cfg->fc_src, &rtmsg->rtmsg_src);
1719         ipv6_addr_copy(&cfg->fc_gateway, &rtmsg->rtmsg_gateway);
1720 }
1721
1722 int ipv6_route_ioctl(unsigned int cmd, void __user *arg)
1723 {
1724         struct fib6_config cfg;
1725         struct in6_rtmsg rtmsg;
1726         int err;
1727
1728         switch(cmd) {
1729         case SIOCADDRT:         /* Add a route */
1730         case SIOCDELRT:         /* Delete a route */
1731                 if (!capable(CAP_NET_ADMIN))
1732                         return -EPERM;
1733                 err = copy_from_user(&rtmsg, arg,
1734                                      sizeof(struct in6_rtmsg));
1735                 if (err)
1736                         return -EFAULT;
1737
1738                 rtmsg_to_fib6_config(&rtmsg, &cfg);
1739
1740                 rtnl_lock();
1741                 switch (cmd) {
1742                 case SIOCADDRT:
1743                         err = ip6_route_add(&cfg);
1744                         break;
1745                 case SIOCDELRT:
1746                         err = ip6_route_del(&cfg);
1747                         break;
1748                 default:
1749                         err = -EINVAL;
1750                 }
1751                 rtnl_unlock();
1752
1753                 return err;
1754         }
1755
1756         return -EINVAL;
1757 }
1758
1759 /*
1760  *      Drop the packet on the floor
1761  */
1762
1763 static inline int ip6_pkt_drop(struct sk_buff *skb, int code,
1764                                int ipstats_mib_noroutes)
1765 {
1766         int type;
1767         switch (ipstats_mib_noroutes) {
1768         case IPSTATS_MIB_INNOROUTES:
1769                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
1770                 if (type == IPV6_ADDR_ANY || type == IPV6_ADDR_RESERVED) {
1771                         IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INADDRERRORS);
1772                         break;
1773                 }
1774                 /* FALLTHROUGH */
1775         case IPSTATS_MIB_OUTNOROUTES:
1776                 IP6_INC_STATS(ip6_dst_idev(skb->dst), ipstats_mib_noroutes);
1777                 break;
1778         }
1779         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0, skb->dev);
1780         kfree_skb(skb);
1781         return 0;
1782 }
1783
1784 static int ip6_pkt_discard(struct sk_buff *skb)
1785 {
1786         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
1787 }
1788
1789 static int ip6_pkt_discard_out(struct sk_buff *skb)
1790 {
1791         skb->dev = skb->dst->dev;
1792         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
1793 }
1794
1795 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1796
1797 static int ip6_pkt_prohibit(struct sk_buff *skb)
1798 {
1799         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
1800 }
1801
1802 static int ip6_pkt_prohibit_out(struct sk_buff *skb)
1803 {
1804         skb->dev = skb->dst->dev;
1805         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
1806 }
1807
1808 #endif
1809
1810 /*
1811  *      Allocate a dst for local (unicast / anycast) address.
1812  */
1813
1814 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
1815                                     const struct in6_addr *addr,
1816                                     int anycast)
1817 {
1818         struct rt6_info *rt = ip6_dst_alloc();
1819
1820         if (rt == NULL)
1821                 return ERR_PTR(-ENOMEM);
1822
1823         dev_hold(init_net.loopback_dev);
1824         in6_dev_hold(idev);
1825
1826         rt->u.dst.flags = DST_HOST;
1827         rt->u.dst.input = ip6_input;
1828         rt->u.dst.output = ip6_output;
1829         rt->rt6i_dev = init_net.loopback_dev;
1830         rt->rt6i_idev = idev;
1831         rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev);
1832         rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst));
1833         rt->u.dst.metrics[RTAX_HOPLIMIT-1] = -1;
1834         rt->u.dst.obsolete = -1;
1835
1836         rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP;
1837         if (anycast)
1838                 rt->rt6i_flags |= RTF_ANYCAST;
1839         else
1840                 rt->rt6i_flags |= RTF_LOCAL;
1841         rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway);
1842         if (rt->rt6i_nexthop == NULL) {
1843                 dst_free(&rt->u.dst);
1844                 return ERR_PTR(-ENOMEM);
1845         }
1846
1847         ipv6_addr_copy(&rt->rt6i_dst.addr, addr);
1848         rt->rt6i_dst.plen = 128;
1849         rt->rt6i_table = fib6_get_table(RT6_TABLE_LOCAL);
1850
1851         atomic_set(&rt->u.dst.__refcnt, 1);
1852
1853         return rt;
1854 }
1855
1856 static int fib6_ifdown(struct rt6_info *rt, void *arg)
1857 {
1858         if (((void*)rt->rt6i_dev == arg || arg == NULL) &&
1859             rt != &ip6_null_entry) {
1860                 RT6_TRACE("deleted by ifdown %p\n", rt);
1861                 return -1;
1862         }
1863         return 0;
1864 }
1865
1866 void rt6_ifdown(struct net_device *dev)
1867 {
1868         fib6_clean_all(fib6_ifdown, 0, dev);
1869 }
1870
1871 struct rt6_mtu_change_arg
1872 {
1873         struct net_device *dev;
1874         unsigned mtu;
1875 };
1876
1877 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg)
1878 {
1879         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
1880         struct inet6_dev *idev;
1881
1882         /* In IPv6 pmtu discovery is not optional,
1883            so that RTAX_MTU lock cannot disable it.
1884            We still use this lock to block changes
1885            caused by addrconf/ndisc.
1886         */
1887
1888         idev = __in6_dev_get(arg->dev);
1889         if (idev == NULL)
1890                 return 0;
1891
1892         /* For administrative MTU increase, there is no way to discover
1893            IPv6 PMTU increase, so PMTU increase should be updated here.
1894            Since RFC 1981 doesn't include administrative MTU increase
1895            update PMTU increase is a MUST. (i.e. jumbo frame)
1896          */
1897         /*
1898            If new MTU is less than route PMTU, this new MTU will be the
1899            lowest MTU in the path, update the route PMTU to reflect PMTU
1900            decreases; if new MTU is greater than route PMTU, and the
1901            old MTU is the lowest MTU in the path, update the route PMTU
1902            to reflect the increase. In this case if the other nodes' MTU
1903            also have the lowest MTU, TOO BIG MESSAGE will be lead to
1904            PMTU discouvery.
1905          */
1906         if (rt->rt6i_dev == arg->dev &&
1907             !dst_metric_locked(&rt->u.dst, RTAX_MTU) &&
1908             (dst_mtu(&rt->u.dst) > arg->mtu ||
1909              (dst_mtu(&rt->u.dst) < arg->mtu &&
1910               dst_mtu(&rt->u.dst) == idev->cnf.mtu6))) {
1911                 rt->u.dst.metrics[RTAX_MTU-1] = arg->mtu;
1912                 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(arg->mtu);
1913         }
1914         return 0;
1915 }
1916
1917 void rt6_mtu_change(struct net_device *dev, unsigned mtu)
1918 {
1919         struct rt6_mtu_change_arg arg = {
1920                 .dev = dev,
1921                 .mtu = mtu,
1922         };
1923
1924         fib6_clean_all(rt6_mtu_change_route, 0, &arg);
1925 }
1926
1927 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
1928         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
1929         [RTA_OIF]               = { .type = NLA_U32 },
1930         [RTA_IIF]               = { .type = NLA_U32 },
1931         [RTA_PRIORITY]          = { .type = NLA_U32 },
1932         [RTA_METRICS]           = { .type = NLA_NESTED },
1933 };
1934
1935 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
1936                               struct fib6_config *cfg)
1937 {
1938         struct rtmsg *rtm;
1939         struct nlattr *tb[RTA_MAX+1];
1940         int err;
1941
1942         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
1943         if (err < 0)
1944                 goto errout;
1945
1946         err = -EINVAL;
1947         rtm = nlmsg_data(nlh);
1948         memset(cfg, 0, sizeof(*cfg));
1949
1950         cfg->fc_table = rtm->rtm_table;
1951         cfg->fc_dst_len = rtm->rtm_dst_len;
1952         cfg->fc_src_len = rtm->rtm_src_len;
1953         cfg->fc_flags = RTF_UP;
1954         cfg->fc_protocol = rtm->rtm_protocol;
1955
1956         if (rtm->rtm_type == RTN_UNREACHABLE)
1957                 cfg->fc_flags |= RTF_REJECT;
1958
1959         cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
1960         cfg->fc_nlinfo.nlh = nlh;
1961
1962         if (tb[RTA_GATEWAY]) {
1963                 nla_memcpy(&cfg->fc_gateway, tb[RTA_GATEWAY], 16);
1964                 cfg->fc_flags |= RTF_GATEWAY;
1965         }
1966
1967         if (tb[RTA_DST]) {
1968                 int plen = (rtm->rtm_dst_len + 7) >> 3;
1969
1970                 if (nla_len(tb[RTA_DST]) < plen)
1971                         goto errout;
1972
1973                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
1974         }
1975
1976         if (tb[RTA_SRC]) {
1977                 int plen = (rtm->rtm_src_len + 7) >> 3;
1978
1979                 if (nla_len(tb[RTA_SRC]) < plen)
1980                         goto errout;
1981
1982                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
1983         }
1984
1985         if (tb[RTA_OIF])
1986                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
1987
1988         if (tb[RTA_PRIORITY])
1989                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
1990
1991         if (tb[RTA_METRICS]) {
1992                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
1993                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
1994         }
1995
1996         if (tb[RTA_TABLE])
1997                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
1998
1999         err = 0;
2000 errout:
2001         return err;
2002 }
2003
2004 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
2005 {
2006         struct fib6_config cfg;
2007         int err;
2008
2009         err = rtm_to_fib6_config(skb, nlh, &cfg);
2010         if (err < 0)
2011                 return err;
2012
2013         return ip6_route_del(&cfg);
2014 }
2015
2016 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
2017 {
2018         struct fib6_config cfg;
2019         int err;
2020
2021         err = rtm_to_fib6_config(skb, nlh, &cfg);
2022         if (err < 0)
2023                 return err;
2024
2025         return ip6_route_add(&cfg);
2026 }
2027
2028 static inline size_t rt6_nlmsg_size(void)
2029 {
2030         return NLMSG_ALIGN(sizeof(struct rtmsg))
2031                + nla_total_size(16) /* RTA_SRC */
2032                + nla_total_size(16) /* RTA_DST */
2033                + nla_total_size(16) /* RTA_GATEWAY */
2034                + nla_total_size(16) /* RTA_PREFSRC */
2035                + nla_total_size(4) /* RTA_TABLE */
2036                + nla_total_size(4) /* RTA_IIF */
2037                + nla_total_size(4) /* RTA_OIF */
2038                + nla_total_size(4) /* RTA_PRIORITY */
2039                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
2040                + nla_total_size(sizeof(struct rta_cacheinfo));
2041 }
2042
2043 static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
2044                          struct in6_addr *dst, struct in6_addr *src,
2045                          int iif, int type, u32 pid, u32 seq,
2046                          int prefix, unsigned int flags)
2047 {
2048         struct rtmsg *rtm;
2049         struct nlmsghdr *nlh;
2050         long expires;
2051         u32 table;
2052
2053         if (prefix) {   /* user wants prefix routes only */
2054                 if (!(rt->rt6i_flags & RTF_PREFIX_RT)) {
2055                         /* success since this is not a prefix route */
2056                         return 1;
2057                 }
2058         }
2059
2060         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtm), flags);
2061         if (nlh == NULL)
2062                 return -EMSGSIZE;
2063
2064         rtm = nlmsg_data(nlh);
2065         rtm->rtm_family = AF_INET6;
2066         rtm->rtm_dst_len = rt->rt6i_dst.plen;
2067         rtm->rtm_src_len = rt->rt6i_src.plen;
2068         rtm->rtm_tos = 0;
2069         if (rt->rt6i_table)
2070                 table = rt->rt6i_table->tb6_id;
2071         else
2072                 table = RT6_TABLE_UNSPEC;
2073         rtm->rtm_table = table;
2074         NLA_PUT_U32(skb, RTA_TABLE, table);
2075         if (rt->rt6i_flags&RTF_REJECT)
2076                 rtm->rtm_type = RTN_UNREACHABLE;
2077         else if (rt->rt6i_dev && (rt->rt6i_dev->flags&IFF_LOOPBACK))
2078                 rtm->rtm_type = RTN_LOCAL;
2079         else
2080                 rtm->rtm_type = RTN_UNICAST;
2081         rtm->rtm_flags = 0;
2082         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
2083         rtm->rtm_protocol = rt->rt6i_protocol;
2084         if (rt->rt6i_flags&RTF_DYNAMIC)
2085                 rtm->rtm_protocol = RTPROT_REDIRECT;
2086         else if (rt->rt6i_flags & RTF_ADDRCONF)
2087                 rtm->rtm_protocol = RTPROT_KERNEL;
2088         else if (rt->rt6i_flags&RTF_DEFAULT)
2089                 rtm->rtm_protocol = RTPROT_RA;
2090
2091         if (rt->rt6i_flags&RTF_CACHE)
2092                 rtm->rtm_flags |= RTM_F_CLONED;
2093
2094         if (dst) {
2095                 NLA_PUT(skb, RTA_DST, 16, dst);
2096                 rtm->rtm_dst_len = 128;
2097         } else if (rtm->rtm_dst_len)
2098                 NLA_PUT(skb, RTA_DST, 16, &rt->rt6i_dst.addr);
2099 #ifdef CONFIG_IPV6_SUBTREES
2100         if (src) {
2101                 NLA_PUT(skb, RTA_SRC, 16, src);
2102                 rtm->rtm_src_len = 128;
2103         } else if (rtm->rtm_src_len)
2104                 NLA_PUT(skb, RTA_SRC, 16, &rt->rt6i_src.addr);
2105 #endif
2106         if (iif)
2107                 NLA_PUT_U32(skb, RTA_IIF, iif);
2108         else if (dst) {
2109                 struct in6_addr saddr_buf;
2110                 if (ipv6_get_saddr(&rt->u.dst, dst, &saddr_buf) == 0)
2111                         NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);
2112         }
2113
2114         if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2115                 goto nla_put_failure;
2116
2117         if (rt->u.dst.neighbour)
2118                 NLA_PUT(skb, RTA_GATEWAY, 16, &rt->u.dst.neighbour->primary_key);
2119
2120         if (rt->u.dst.dev)
2121                 NLA_PUT_U32(skb, RTA_OIF, rt->rt6i_dev->ifindex);
2122
2123         NLA_PUT_U32(skb, RTA_PRIORITY, rt->rt6i_metric);
2124
2125         expires = rt->rt6i_expires ? rt->rt6i_expires - jiffies : 0;
2126         if (rtnl_put_cacheinfo(skb, &rt->u.dst, 0, 0, 0,
2127                                expires, rt->u.dst.error) < 0)
2128                 goto nla_put_failure;
2129
2130         return nlmsg_end(skb, nlh);
2131
2132 nla_put_failure:
2133         nlmsg_cancel(skb, nlh);
2134         return -EMSGSIZE;
2135 }
2136
2137 int rt6_dump_route(struct rt6_info *rt, void *p_arg)
2138 {
2139         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
2140         int prefix;
2141
2142         if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) {
2143                 struct rtmsg *rtm = nlmsg_data(arg->cb->nlh);
2144                 prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0;
2145         } else
2146                 prefix = 0;
2147
2148         return rt6_fill_node(arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
2149                      NETLINK_CB(arg->cb->skb).pid, arg->cb->nlh->nlmsg_seq,
2150                      prefix, NLM_F_MULTI);
2151 }
2152
2153 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2154 {
2155         struct nlattr *tb[RTA_MAX+1];
2156         struct rt6_info *rt;
2157         struct sk_buff *skb;
2158         struct rtmsg *rtm;
2159         struct flowi fl;
2160         int err, iif = 0;
2161
2162         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
2163         if (err < 0)
2164                 goto errout;
2165
2166         err = -EINVAL;
2167         memset(&fl, 0, sizeof(fl));
2168
2169         if (tb[RTA_SRC]) {
2170                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
2171                         goto errout;
2172
2173                 ipv6_addr_copy(&fl.fl6_src, nla_data(tb[RTA_SRC]));
2174         }
2175
2176         if (tb[RTA_DST]) {
2177                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
2178                         goto errout;
2179
2180                 ipv6_addr_copy(&fl.fl6_dst, nla_data(tb[RTA_DST]));
2181         }
2182
2183         if (tb[RTA_IIF])
2184                 iif = nla_get_u32(tb[RTA_IIF]);
2185
2186         if (tb[RTA_OIF])
2187                 fl.oif = nla_get_u32(tb[RTA_OIF]);
2188
2189         if (iif) {
2190                 struct net_device *dev;
2191                 dev = __dev_get_by_index(&init_net, iif);
2192                 if (!dev) {
2193                         err = -ENODEV;
2194                         goto errout;
2195                 }
2196         }
2197
2198         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2199         if (skb == NULL) {
2200                 err = -ENOBUFS;
2201                 goto errout;
2202         }
2203
2204         /* Reserve room for dummy headers, this skb can pass
2205            through good chunk of routing engine.
2206          */
2207         skb_reset_mac_header(skb);
2208         skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr));
2209
2210         rt = (struct rt6_info*) ip6_route_output(NULL, &fl);
2211         skb->dst = &rt->u.dst;
2212
2213         err = rt6_fill_node(skb, rt, &fl.fl6_dst, &fl.fl6_src, iif,
2214                             RTM_NEWROUTE, NETLINK_CB(in_skb).pid,
2215                             nlh->nlmsg_seq, 0, 0);
2216         if (err < 0) {
2217                 kfree_skb(skb);
2218                 goto errout;
2219         }
2220
2221         err = rtnl_unicast(skb, NETLINK_CB(in_skb).pid);
2222 errout:
2223         return err;
2224 }
2225
2226 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info)
2227 {
2228         struct sk_buff *skb;
2229         u32 pid = 0, seq = 0;
2230         struct nlmsghdr *nlh = NULL;
2231         int err = -ENOBUFS;
2232
2233         if (info) {
2234                 pid = info->pid;
2235                 nlh = info->nlh;
2236                 if (nlh)
2237                         seq = nlh->nlmsg_seq;
2238         }
2239
2240         skb = nlmsg_new(rt6_nlmsg_size(), gfp_any());
2241         if (skb == NULL)
2242                 goto errout;
2243
2244         err = rt6_fill_node(skb, rt, NULL, NULL, 0, event, pid, seq, 0, 0);
2245         if (err < 0) {
2246                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
2247                 WARN_ON(err == -EMSGSIZE);
2248                 kfree_skb(skb);
2249                 goto errout;
2250         }
2251         err = rtnl_notify(skb, pid, RTNLGRP_IPV6_ROUTE, nlh, gfp_any());
2252 errout:
2253         if (err < 0)
2254                 rtnl_set_sk_err(RTNLGRP_IPV6_ROUTE, err);
2255 }
2256
2257 /*
2258  *      /proc
2259  */
2260
2261 #ifdef CONFIG_PROC_FS
2262
2263 #define RT6_INFO_LEN (32 + 4 + 32 + 4 + 32 + 40 + 5 + 1)
2264
2265 struct rt6_proc_arg
2266 {
2267         char *buffer;
2268         int offset;
2269         int length;
2270         int skip;
2271         int len;
2272 };
2273
2274 static int rt6_info_route(struct rt6_info *rt, void *p_arg)
2275 {
2276         struct seq_file *m = p_arg;
2277
2278         seq_printf(m, NIP6_SEQFMT " %02x ", NIP6(rt->rt6i_dst.addr),
2279                    rt->rt6i_dst.plen);
2280
2281 #ifdef CONFIG_IPV6_SUBTREES
2282         seq_printf(m, NIP6_SEQFMT " %02x ", NIP6(rt->rt6i_src.addr),
2283                    rt->rt6i_src.plen);
2284 #else
2285         seq_puts(m, "00000000000000000000000000000000 00 ");
2286 #endif
2287
2288         if (rt->rt6i_nexthop) {
2289                 seq_printf(m, NIP6_SEQFMT,
2290                            NIP6(*((struct in6_addr *)rt->rt6i_nexthop->primary_key)));
2291         } else {
2292                 seq_puts(m, "00000000000000000000000000000000");
2293         }
2294         seq_printf(m, " %08x %08x %08x %08x %8s\n",
2295                    rt->rt6i_metric, atomic_read(&rt->u.dst.__refcnt),
2296                    rt->u.dst.__use, rt->rt6i_flags,
2297                    rt->rt6i_dev ? rt->rt6i_dev->name : "");
2298         return 0;
2299 }
2300
2301 static int ipv6_route_show(struct seq_file *m, void *v)
2302 {
2303         fib6_clean_all(rt6_info_route, 0, m);
2304         return 0;
2305 }
2306
2307 static int ipv6_route_open(struct inode *inode, struct file *file)
2308 {
2309         return single_open(file, ipv6_route_show, NULL);
2310 }
2311
2312 static const struct file_operations ipv6_route_proc_fops = {
2313         .owner          = THIS_MODULE,
2314         .open           = ipv6_route_open,
2315         .read           = seq_read,
2316         .llseek         = seq_lseek,
2317         .release        = single_release,
2318 };
2319
2320 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
2321 {
2322         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
2323                       rt6_stats.fib_nodes, rt6_stats.fib_route_nodes,
2324                       rt6_stats.fib_rt_alloc, rt6_stats.fib_rt_entries,
2325                       rt6_stats.fib_rt_cache,
2326                       atomic_read(&ip6_dst_ops.entries),
2327                       rt6_stats.fib_discarded_routes);
2328
2329         return 0;
2330 }
2331
2332 static int rt6_stats_seq_open(struct inode *inode, struct file *file)
2333 {
2334         return single_open(file, rt6_stats_seq_show, NULL);
2335 }
2336
2337 static const struct file_operations rt6_stats_seq_fops = {
2338         .owner   = THIS_MODULE,
2339         .open    = rt6_stats_seq_open,
2340         .read    = seq_read,
2341         .llseek  = seq_lseek,
2342         .release = single_release,
2343 };
2344 #endif  /* CONFIG_PROC_FS */
2345
2346 #ifdef CONFIG_SYSCTL
2347
2348 static int flush_delay;
2349
2350 static
2351 int ipv6_sysctl_rtcache_flush(ctl_table *ctl, int write, struct file * filp,
2352                               void __user *buffer, size_t *lenp, loff_t *ppos)
2353 {
2354         if (write) {
2355                 proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
2356                 fib6_run_gc(flush_delay <= 0 ? ~0UL : (unsigned long)flush_delay);
2357                 return 0;
2358         } else
2359                 return -EINVAL;
2360 }
2361
2362 ctl_table ipv6_route_table[] = {
2363         {
2364                 .procname       =       "flush",
2365                 .data           =       &flush_delay,
2366                 .maxlen         =       sizeof(int),
2367                 .mode           =       0200,
2368                 .proc_handler   =       &ipv6_sysctl_rtcache_flush
2369         },
2370         {
2371                 .ctl_name       =       NET_IPV6_ROUTE_GC_THRESH,
2372                 .procname       =       "gc_thresh",
2373                 .data           =       &ip6_dst_ops.gc_thresh,
2374                 .maxlen         =       sizeof(int),
2375                 .mode           =       0644,
2376                 .proc_handler   =       &proc_dointvec,
2377         },
2378         {
2379                 .ctl_name       =       NET_IPV6_ROUTE_MAX_SIZE,
2380                 .procname       =       "max_size",
2381                 .data           =       &ip6_rt_max_size,
2382                 .maxlen         =       sizeof(int),
2383                 .mode           =       0644,
2384                 .proc_handler   =       &proc_dointvec,
2385         },
2386         {
2387                 .ctl_name       =       NET_IPV6_ROUTE_GC_MIN_INTERVAL,
2388                 .procname       =       "gc_min_interval",
2389                 .data           =       &ip6_rt_gc_min_interval,
2390                 .maxlen         =       sizeof(int),
2391                 .mode           =       0644,
2392                 .proc_handler   =       &proc_dointvec_jiffies,
2393                 .strategy       =       &sysctl_jiffies,
2394         },
2395         {
2396                 .ctl_name       =       NET_IPV6_ROUTE_GC_TIMEOUT,
2397                 .procname       =       "gc_timeout",
2398                 .data           =       &ip6_rt_gc_timeout,
2399                 .maxlen         =       sizeof(int),
2400                 .mode           =       0644,
2401                 .proc_handler   =       &proc_dointvec_jiffies,
2402                 .strategy       =       &sysctl_jiffies,
2403         },
2404         {
2405                 .ctl_name       =       NET_IPV6_ROUTE_GC_INTERVAL,
2406                 .procname       =       "gc_interval",
2407                 .data           =       &ip6_rt_gc_interval,
2408                 .maxlen         =       sizeof(int),
2409                 .mode           =       0644,
2410                 .proc_handler   =       &proc_dointvec_jiffies,
2411                 .strategy       =       &sysctl_jiffies,
2412         },
2413         {
2414                 .ctl_name       =       NET_IPV6_ROUTE_GC_ELASTICITY,
2415                 .procname       =       "gc_elasticity",
2416                 .data           =       &ip6_rt_gc_elasticity,
2417                 .maxlen         =       sizeof(int),
2418                 .mode           =       0644,
2419                 .proc_handler   =       &proc_dointvec_jiffies,
2420                 .strategy       =       &sysctl_jiffies,
2421         },
2422         {
2423                 .ctl_name       =       NET_IPV6_ROUTE_MTU_EXPIRES,
2424                 .procname       =       "mtu_expires",
2425                 .data           =       &ip6_rt_mtu_expires,
2426                 .maxlen         =       sizeof(int),
2427                 .mode           =       0644,
2428                 .proc_handler   =       &proc_dointvec_jiffies,
2429                 .strategy       =       &sysctl_jiffies,
2430         },
2431         {
2432                 .ctl_name       =       NET_IPV6_ROUTE_MIN_ADVMSS,
2433                 .procname       =       "min_adv_mss",
2434                 .data           =       &ip6_rt_min_advmss,
2435                 .maxlen         =       sizeof(int),
2436                 .mode           =       0644,
2437                 .proc_handler   =       &proc_dointvec_jiffies,
2438                 .strategy       =       &sysctl_jiffies,
2439         },
2440         {
2441                 .ctl_name       =       NET_IPV6_ROUTE_GC_MIN_INTERVAL_MS,
2442                 .procname       =       "gc_min_interval_ms",
2443                 .data           =       &ip6_rt_gc_min_interval,
2444                 .maxlen         =       sizeof(int),
2445                 .mode           =       0644,
2446                 .proc_handler   =       &proc_dointvec_ms_jiffies,
2447                 .strategy       =       &sysctl_ms_jiffies,
2448         },
2449         { .ctl_name = 0 }
2450 };
2451
2452 #endif
2453
2454 void __init ip6_route_init(void)
2455 {
2456         ip6_dst_ops.kmem_cachep =
2457                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
2458                                   SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2459         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops.kmem_cachep;
2460
2461         fib6_init();
2462         proc_net_fops_create(&init_net, "ipv6_route", 0, &ipv6_route_proc_fops);
2463         proc_net_fops_create(&init_net, "rt6_stats", S_IRUGO, &rt6_stats_seq_fops);
2464 #ifdef CONFIG_XFRM
2465         xfrm6_init();
2466 #endif
2467 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2468         fib6_rules_init();
2469 #endif
2470
2471         __rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL);
2472         __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL);
2473         __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL);
2474 }
2475
2476 void ip6_route_cleanup(void)
2477 {
2478 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2479         fib6_rules_cleanup();
2480 #endif
2481 #ifdef CONFIG_PROC_FS
2482         proc_net_remove(&init_net, "ipv6_route");
2483         proc_net_remove(&init_net, "rt6_stats");
2484 #endif
2485 #ifdef CONFIG_XFRM
2486         xfrm6_fini();
2487 #endif
2488         rt6_ifdown(NULL);
2489         fib6_gc_cleanup();
2490         kmem_cache_destroy(ip6_dst_ops.kmem_cachep);
2491 }