73eb8c33e9f0022692fdf6cfe387f83322d72d99
[linux-2.6.git] / net / ipv6 / ndisc.c
1 /*
2  *      Neighbour Discovery for IPv6
3  *      Linux INET6 implementation 
4  *
5  *      Authors:
6  *      Pedro Roque             <roque@di.fc.ul.pt>     
7  *      Mike Shaver             <shaver@ingenia.com>
8  *
9  *      This program is free software; you can redistribute it and/or
10  *      modify it under the terms of the GNU General Public License
11  *      as published by the Free Software Foundation; either version
12  *      2 of the License, or (at your option) any later version.
13  */
14
15 /*
16  *      Changes:
17  *
18  *      Lars Fenneberg                  :       fixed MTU setting on receipt
19  *                                              of an RA.
20  *
21  *      Janos Farkas                    :       kmalloc failure checks
22  *      Alexey Kuznetsov                :       state machine reworked
23  *                                              and moved to net/core.
24  *      Pekka Savola                    :       RFC2461 validation
25  *      YOSHIFUJI Hideaki @USAGI        :       Verify ND options properly
26  */
27
28 /* Set to 3 to get tracing... */
29 #define ND_DEBUG 1
30
31 #define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0)
32 #define ND_NOPRINTK(x...) do { ; } while(0)
33 #define ND_PRINTK0 ND_PRINTK
34 #define ND_PRINTK1 ND_NOPRINTK
35 #define ND_PRINTK2 ND_NOPRINTK
36 #define ND_PRINTK3 ND_NOPRINTK
37 #if ND_DEBUG >= 1
38 #undef ND_PRINTK1
39 #define ND_PRINTK1 ND_PRINTK
40 #endif
41 #if ND_DEBUG >= 2
42 #undef ND_PRINTK2
43 #define ND_PRINTK2 ND_PRINTK
44 #endif
45 #if ND_DEBUG >= 3
46 #undef ND_PRINTK3
47 #define ND_PRINTK3 ND_PRINTK
48 #endif
49
50 #include <linux/module.h>
51 #include <linux/errno.h>
52 #include <linux/types.h>
53 #include <linux/socket.h>
54 #include <linux/sockios.h>
55 #include <linux/sched.h>
56 #include <linux/net.h>
57 #include <linux/in6.h>
58 #include <linux/route.h>
59 #include <linux/init.h>
60 #include <linux/rcupdate.h>
61 #ifdef CONFIG_SYSCTL
62 #include <linux/sysctl.h>
63 #endif
64
65 #include <linux/if_addr.h>
66 #include <linux/if_arp.h>
67 #include <linux/ipv6.h>
68 #include <linux/icmpv6.h>
69 #include <linux/jhash.h>
70
71 #include <net/sock.h>
72 #include <net/snmp.h>
73
74 #include <net/ipv6.h>
75 #include <net/protocol.h>
76 #include <net/ndisc.h>
77 #include <net/ip6_route.h>
78 #include <net/addrconf.h>
79 #include <net/icmp.h>
80
81 #include <net/flow.h>
82 #include <net/ip6_checksum.h>
83 #include <linux/proc_fs.h>
84
85 #include <linux/netfilter.h>
86 #include <linux/netfilter_ipv6.h>
87
88 static struct socket *ndisc_socket;
89
90 static u32 ndisc_hash(const void *pkey, const struct net_device *dev);
91 static int ndisc_constructor(struct neighbour *neigh);
92 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
93 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
94 static int pndisc_constructor(struct pneigh_entry *n);
95 static void pndisc_destructor(struct pneigh_entry *n);
96 static void pndisc_redo(struct sk_buff *skb);
97
98 static struct neigh_ops ndisc_generic_ops = {
99         .family =               AF_INET6,
100         .solicit =              ndisc_solicit,
101         .error_report =         ndisc_error_report,
102         .output =               neigh_resolve_output,
103         .connected_output =     neigh_connected_output,
104         .hh_output =            dev_queue_xmit,
105         .queue_xmit =           dev_queue_xmit,
106 };
107
108 static struct neigh_ops ndisc_hh_ops = {
109         .family =               AF_INET6,
110         .solicit =              ndisc_solicit,
111         .error_report =         ndisc_error_report,
112         .output =               neigh_resolve_output,
113         .connected_output =     neigh_resolve_output,
114         .hh_output =            dev_queue_xmit,
115         .queue_xmit =           dev_queue_xmit,
116 };
117
118
119 static struct neigh_ops ndisc_direct_ops = {
120         .family =               AF_INET6,
121         .output =               dev_queue_xmit,
122         .connected_output =     dev_queue_xmit,
123         .hh_output =            dev_queue_xmit,
124         .queue_xmit =           dev_queue_xmit,
125 };
126
127 struct neigh_table nd_tbl = {
128         .family =       AF_INET6,
129         .entry_size =   sizeof(struct neighbour) + sizeof(struct in6_addr),
130         .key_len =      sizeof(struct in6_addr),
131         .hash =         ndisc_hash,
132         .constructor =  ndisc_constructor,
133         .pconstructor = pndisc_constructor,
134         .pdestructor =  pndisc_destructor,
135         .proxy_redo =   pndisc_redo,
136         .id =           "ndisc_cache",
137         .parms = {
138                 .tbl =                  &nd_tbl,
139                 .base_reachable_time =  30 * HZ,
140                 .retrans_time =  1 * HZ,
141                 .gc_staletime = 60 * HZ,
142                 .reachable_time =               30 * HZ,
143                 .delay_probe_time =      5 * HZ,
144                 .queue_len =             3,
145                 .ucast_probes =  3,
146                 .mcast_probes =  3,
147                 .anycast_delay =         1 * HZ,
148                 .proxy_delay =          (8 * HZ) / 10,
149                 .proxy_qlen =           64,
150         },
151         .gc_interval =    30 * HZ,
152         .gc_thresh1 =    128,
153         .gc_thresh2 =    512,
154         .gc_thresh3 =   1024,
155 };
156
157 /* ND options */
158 struct ndisc_options {
159         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
160 #ifdef CONFIG_IPV6_ROUTE_INFO
161         struct nd_opt_hdr *nd_opts_ri;
162         struct nd_opt_hdr *nd_opts_ri_end;
163 #endif
164 };
165
166 #define nd_opts_src_lladdr      nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
167 #define nd_opts_tgt_lladdr      nd_opt_array[ND_OPT_TARGET_LL_ADDR]
168 #define nd_opts_pi              nd_opt_array[ND_OPT_PREFIX_INFO]
169 #define nd_opts_pi_end          nd_opt_array[__ND_OPT_PREFIX_INFO_END]
170 #define nd_opts_rh              nd_opt_array[ND_OPT_REDIRECT_HDR]
171 #define nd_opts_mtu             nd_opt_array[ND_OPT_MTU]
172
173 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
174
175 /*
176  * Return the padding between the option length and the start of the
177  * link addr.  Currently only IP-over-InfiniBand needs this, although
178  * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
179  * also need a pad of 2.
180  */
181 static int ndisc_addr_option_pad(unsigned short type)
182 {
183         switch (type) {
184         case ARPHRD_INFINIBAND: return 2;
185         default:                return 0;
186         }
187 }
188
189 static inline int ndisc_opt_addr_space(struct net_device *dev)
190 {
191         return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
192 }
193
194 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
195                                   unsigned short addr_type)
196 {
197         int space = NDISC_OPT_SPACE(data_len);
198         int pad   = ndisc_addr_option_pad(addr_type);
199
200         opt[0] = type;
201         opt[1] = space>>3;
202
203         memset(opt + 2, 0, pad);
204         opt   += pad;
205         space -= pad;
206
207         memcpy(opt+2, data, data_len);
208         data_len += 2;
209         opt += data_len;
210         if ((space -= data_len) > 0)
211                 memset(opt, 0, space);
212         return opt + space;
213 }
214
215 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
216                                             struct nd_opt_hdr *end)
217 {
218         int type;
219         if (!cur || !end || cur >= end)
220                 return NULL;
221         type = cur->nd_opt_type;
222         do {
223                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
224         } while(cur < end && cur->nd_opt_type != type);
225         return (cur <= end && cur->nd_opt_type == type ? cur : NULL);
226 }
227
228 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
229                                                  struct ndisc_options *ndopts)
230 {
231         struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
232
233         if (!nd_opt || opt_len < 0 || !ndopts)
234                 return NULL;
235         memset(ndopts, 0, sizeof(*ndopts));
236         while (opt_len) {
237                 int l;
238                 if (opt_len < sizeof(struct nd_opt_hdr))
239                         return NULL;
240                 l = nd_opt->nd_opt_len << 3;
241                 if (opt_len < l || l == 0)
242                         return NULL;
243                 switch (nd_opt->nd_opt_type) {
244                 case ND_OPT_SOURCE_LL_ADDR:
245                 case ND_OPT_TARGET_LL_ADDR:
246                 case ND_OPT_MTU:
247                 case ND_OPT_REDIRECT_HDR:
248                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
249                                 ND_PRINTK2(KERN_WARNING
250                                            "%s(): duplicated ND6 option found: type=%d\n",
251                                            __FUNCTION__,
252                                            nd_opt->nd_opt_type);
253                         } else {
254                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
255                         }
256                         break;
257                 case ND_OPT_PREFIX_INFO:
258                         ndopts->nd_opts_pi_end = nd_opt;
259                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0)
260                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
261                         break;
262 #ifdef CONFIG_IPV6_ROUTE_INFO
263                 case ND_OPT_ROUTE_INFO:
264                         ndopts->nd_opts_ri_end = nd_opt;
265                         if (!ndopts->nd_opts_ri)
266                                 ndopts->nd_opts_ri = nd_opt;
267                         break;
268 #endif
269                 default:
270                         /*
271                          * Unknown options must be silently ignored,
272                          * to accommodate future extension to the protocol.
273                          */
274                         ND_PRINTK2(KERN_NOTICE
275                                    "%s(): ignored unsupported option; type=%d, len=%d\n",
276                                    __FUNCTION__,
277                                    nd_opt->nd_opt_type, nd_opt->nd_opt_len);
278                 }
279                 opt_len -= l;
280                 nd_opt = ((void *)nd_opt) + l;
281         }
282         return ndopts;
283 }
284
285 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
286                                       struct net_device *dev)
287 {
288         u8 *lladdr = (u8 *)(p + 1);
289         int lladdrlen = p->nd_opt_len << 3;
290         int prepad = ndisc_addr_option_pad(dev->type);
291         if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
292                 return NULL;
293         return (lladdr + prepad);
294 }
295
296 int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
297 {
298         switch (dev->type) {
299         case ARPHRD_ETHER:
300         case ARPHRD_IEEE802:    /* Not sure. Check it later. --ANK */
301         case ARPHRD_FDDI:
302                 ipv6_eth_mc_map(addr, buf);
303                 return 0;
304         case ARPHRD_IEEE802_TR:
305                 ipv6_tr_mc_map(addr,buf);
306                 return 0;
307         case ARPHRD_ARCNET:
308                 ipv6_arcnet_mc_map(addr, buf);
309                 return 0;
310         case ARPHRD_INFINIBAND:
311                 ipv6_ib_mc_map(addr, buf);
312                 return 0;
313         default:
314                 if (dir) {
315                         memcpy(buf, dev->broadcast, dev->addr_len);
316                         return 0;
317                 }
318         }
319         return -EINVAL;
320 }
321
322 static u32 ndisc_hash(const void *pkey, const struct net_device *dev)
323 {
324         const u32 *p32 = pkey;
325         u32 addr_hash, i;
326
327         addr_hash = 0;
328         for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++)
329                 addr_hash ^= *p32++;
330
331         return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd);
332 }
333
334 static int ndisc_constructor(struct neighbour *neigh)
335 {
336         struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
337         struct net_device *dev = neigh->dev;
338         struct inet6_dev *in6_dev;
339         struct neigh_parms *parms;
340         int is_multicast = ipv6_addr_is_multicast(addr);
341
342         rcu_read_lock();
343         in6_dev = in6_dev_get(dev);
344         if (in6_dev == NULL) {
345                 rcu_read_unlock();
346                 return -EINVAL;
347         }
348
349         parms = in6_dev->nd_parms;
350         __neigh_parms_put(neigh->parms);
351         neigh->parms = neigh_parms_clone(parms);
352         rcu_read_unlock();
353
354         neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
355         if (dev->hard_header == NULL) {
356                 neigh->nud_state = NUD_NOARP;
357                 neigh->ops = &ndisc_direct_ops;
358                 neigh->output = neigh->ops->queue_xmit;
359         } else {
360                 if (is_multicast) {
361                         neigh->nud_state = NUD_NOARP;
362                         ndisc_mc_map(addr, neigh->ha, dev, 1);
363                 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
364                         neigh->nud_state = NUD_NOARP;
365                         memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
366                         if (dev->flags&IFF_LOOPBACK)
367                                 neigh->type = RTN_LOCAL;
368                 } else if (dev->flags&IFF_POINTOPOINT) {
369                         neigh->nud_state = NUD_NOARP;
370                         memcpy(neigh->ha, dev->broadcast, dev->addr_len);
371                 }
372                 if (dev->hard_header_cache)
373                         neigh->ops = &ndisc_hh_ops;
374                 else
375                         neigh->ops = &ndisc_generic_ops;
376                 if (neigh->nud_state&NUD_VALID)
377                         neigh->output = neigh->ops->connected_output;
378                 else
379                         neigh->output = neigh->ops->output;
380         }
381         in6_dev_put(in6_dev);
382         return 0;
383 }
384
385 static int pndisc_constructor(struct pneigh_entry *n)
386 {
387         struct in6_addr *addr = (struct in6_addr*)&n->key;
388         struct in6_addr maddr;
389         struct net_device *dev = n->dev;
390
391         if (dev == NULL || __in6_dev_get(dev) == NULL)
392                 return -EINVAL;
393         addrconf_addr_solict_mult(addr, &maddr);
394         ipv6_dev_mc_inc(dev, &maddr);
395         return 0;
396 }
397
398 static void pndisc_destructor(struct pneigh_entry *n)
399 {
400         struct in6_addr *addr = (struct in6_addr*)&n->key;
401         struct in6_addr maddr;
402         struct net_device *dev = n->dev;
403
404         if (dev == NULL || __in6_dev_get(dev) == NULL)
405                 return;
406         addrconf_addr_solict_mult(addr, &maddr);
407         ipv6_dev_mc_dec(dev, &maddr);
408 }
409
410 /*
411  *      Send a Neighbour Advertisement
412  */
413
414 static inline void ndisc_flow_init(struct flowi *fl, u8 type,
415                             struct in6_addr *saddr, struct in6_addr *daddr,
416                             int oif)
417 {
418         memset(fl, 0, sizeof(*fl));
419         ipv6_addr_copy(&fl->fl6_src, saddr);
420         ipv6_addr_copy(&fl->fl6_dst, daddr);
421         fl->proto               = IPPROTO_ICMPV6;
422         fl->fl_icmp_type        = type;
423         fl->fl_icmp_code        = 0;
424         fl->oif                 = oif;
425         security_sk_classify_flow(ndisc_socket->sk, fl);
426 }
427
428 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
429                    struct in6_addr *daddr, struct in6_addr *solicited_addr,
430                    int router, int solicited, int override, int inc_opt) 
431 {
432         struct in6_addr tmpaddr;
433         struct inet6_ifaddr *ifp;
434         struct inet6_dev *idev;
435         struct flowi fl;
436         struct dst_entry* dst;
437         struct sock *sk = ndisc_socket->sk;
438         struct in6_addr *src_addr;
439         struct nd_msg *msg;
440         int len;
441         struct sk_buff *skb;
442         int err;
443
444         len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
445
446         /* for anycast or proxy, solicited_addr != src_addr */
447         ifp = ipv6_get_ifaddr(solicited_addr, dev, 1);
448         if (ifp) {
449                 src_addr = solicited_addr;
450                 in6_ifa_put(ifp);
451         } else {
452                 if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr))
453                         return;
454                 src_addr = &tmpaddr;
455         }
456
457         ndisc_flow_init(&fl, NDISC_NEIGHBOUR_ADVERTISEMENT, src_addr, daddr,
458                         dev->ifindex);
459
460         dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output);
461         if (!dst)
462                 return;
463
464         err = xfrm_lookup(&dst, &fl, NULL, 0);
465         if (err < 0)
466                 return;
467
468         if (inc_opt) {
469                 if (dev->addr_len)
470                         len += ndisc_opt_addr_space(dev);
471                 else
472                         inc_opt = 0;
473         }
474
475         skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
476                                   1, &err);
477
478         if (skb == NULL) {
479                 ND_PRINTK0(KERN_ERR
480                            "ICMPv6 NA: %s() failed to allocate an skb.\n", 
481                            __FUNCTION__);
482                 dst_release(dst);
483                 return;
484         }
485
486         skb_reserve(skb, LL_RESERVED_SPACE(dev));
487         ip6_nd_hdr(sk, skb, dev, src_addr, daddr, IPPROTO_ICMPV6, len);
488
489         msg = (struct nd_msg *)skb_put(skb, len);
490         skb->h.raw = (unsigned char*)msg;
491
492         msg->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
493         msg->icmph.icmp6_code = 0;
494         msg->icmph.icmp6_cksum = 0;
495
496         msg->icmph.icmp6_unused = 0;
497         msg->icmph.icmp6_router    = router;
498         msg->icmph.icmp6_solicited = solicited;
499         msg->icmph.icmp6_override  = override;
500
501         /* Set the target address. */
502         ipv6_addr_copy(&msg->target, solicited_addr);
503
504         if (inc_opt)
505                 ndisc_fill_addr_option(msg->opt, ND_OPT_TARGET_LL_ADDR, dev->dev_addr,
506                                        dev->addr_len, dev->type);
507
508         /* checksum */
509         msg->icmph.icmp6_cksum = csum_ipv6_magic(src_addr, daddr, len, 
510                                                  IPPROTO_ICMPV6,
511                                                  csum_partial((__u8 *) msg, 
512                                                               len, 0));
513
514         skb->dst = dst;
515         idev = in6_dev_get(dst->dev);
516         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
517         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
518         if (!err) {
519                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTNEIGHBORADVERTISEMENTS);
520                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
521         }
522
523         if (likely(idev != NULL))
524                 in6_dev_put(idev);
525 }        
526
527 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
528                    struct in6_addr *solicit,
529                    struct in6_addr *daddr, struct in6_addr *saddr) 
530 {
531         struct flowi fl;
532         struct dst_entry* dst;
533         struct inet6_dev *idev;
534         struct sock *sk = ndisc_socket->sk;
535         struct sk_buff *skb;
536         struct nd_msg *msg;
537         struct in6_addr addr_buf;
538         int len;
539         int err;
540         int send_llinfo;
541
542         if (saddr == NULL) {
543                 if (ipv6_get_lladdr(dev, &addr_buf))
544                         return;
545                 saddr = &addr_buf;
546         }
547
548         ndisc_flow_init(&fl, NDISC_NEIGHBOUR_SOLICITATION, saddr, daddr,
549                         dev->ifindex);
550
551         dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output);
552         if (!dst)
553                 return;
554
555         err = xfrm_lookup(&dst, &fl, NULL, 0);
556         if (err < 0)
557                 return;
558
559         len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
560         send_llinfo = dev->addr_len && !ipv6_addr_any(saddr);
561         if (send_llinfo)
562                 len += ndisc_opt_addr_space(dev);
563
564         skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
565                                   1, &err);
566         if (skb == NULL) {
567                 ND_PRINTK0(KERN_ERR
568                            "ICMPv6 NA: %s() failed to allocate an skb.\n", 
569                            __FUNCTION__);
570                 dst_release(dst);
571                 return;
572         }
573
574         skb_reserve(skb, LL_RESERVED_SPACE(dev));
575         ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
576
577         msg = (struct nd_msg *)skb_put(skb, len);
578         skb->h.raw = (unsigned char*)msg;
579         msg->icmph.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION;
580         msg->icmph.icmp6_code = 0;
581         msg->icmph.icmp6_cksum = 0;
582         msg->icmph.icmp6_unused = 0;
583
584         /* Set the target address. */
585         ipv6_addr_copy(&msg->target, solicit);
586
587         if (send_llinfo)
588                 ndisc_fill_addr_option(msg->opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr,
589                                        dev->addr_len, dev->type);
590
591         /* checksum */
592         msg->icmph.icmp6_cksum = csum_ipv6_magic(&skb->nh.ipv6h->saddr,
593                                                  daddr, len, 
594                                                  IPPROTO_ICMPV6,
595                                                  csum_partial((__u8 *) msg, 
596                                                               len, 0));
597         /* send it! */
598         skb->dst = dst;
599         idev = in6_dev_get(dst->dev);
600         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
601         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
602         if (!err) {
603                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTNEIGHBORSOLICITS);
604                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
605         }
606
607         if (likely(idev != NULL))
608                 in6_dev_put(idev);
609 }
610
611 void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
612                    struct in6_addr *daddr)
613 {
614         struct flowi fl;
615         struct dst_entry* dst;
616         struct inet6_dev *idev;
617         struct sock *sk = ndisc_socket->sk;
618         struct sk_buff *skb;
619         struct icmp6hdr *hdr;
620         __u8 * opt;
621         int len;
622         int err;
623
624         ndisc_flow_init(&fl, NDISC_ROUTER_SOLICITATION, saddr, daddr,
625                         dev->ifindex);
626
627         dst = ndisc_dst_alloc(dev, NULL, daddr, ip6_output);
628         if (!dst)
629                 return;
630
631         err = xfrm_lookup(&dst, &fl, NULL, 0);
632         if (err < 0)
633                 return;
634
635         len = sizeof(struct icmp6hdr);
636         if (dev->addr_len)
637                 len += ndisc_opt_addr_space(dev);
638
639         skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
640                                   1, &err);
641         if (skb == NULL) {
642                 ND_PRINTK0(KERN_ERR
643                            "ICMPv6 RS: %s() failed to allocate an skb.\n", 
644                            __FUNCTION__);
645                 dst_release(dst);
646                 return;
647         }
648
649         skb_reserve(skb, LL_RESERVED_SPACE(dev));
650         ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
651
652         hdr = (struct icmp6hdr *)skb_put(skb, len);
653         skb->h.raw = (unsigned char*)hdr;
654         hdr->icmp6_type = NDISC_ROUTER_SOLICITATION;
655         hdr->icmp6_code = 0;
656         hdr->icmp6_cksum = 0;
657         hdr->icmp6_unused = 0;
658
659         opt = (u8*) (hdr + 1);
660
661         if (dev->addr_len)
662                 ndisc_fill_addr_option(opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr,
663                                        dev->addr_len, dev->type);
664
665         /* checksum */
666         hdr->icmp6_cksum = csum_ipv6_magic(&skb->nh.ipv6h->saddr, daddr, len,
667                                            IPPROTO_ICMPV6,
668                                            csum_partial((__u8 *) hdr, len, 0));
669
670         /* send it! */
671         skb->dst = dst;
672         idev = in6_dev_get(dst->dev);
673         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS); 
674         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
675         if (!err) {
676                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTROUTERSOLICITS);
677                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
678         }
679
680         if (likely(idev != NULL))
681                 in6_dev_put(idev);
682 }
683                    
684
685 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
686 {
687         /*
688          *      "The sender MUST return an ICMP
689          *       destination unreachable"
690          */
691         dst_link_failure(skb);
692         kfree_skb(skb);
693 }
694
695 /* Called with locked neigh: either read or both */
696
697 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
698 {
699         struct in6_addr *saddr = NULL;
700         struct in6_addr mcaddr;
701         struct net_device *dev = neigh->dev;
702         struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
703         int probes = atomic_read(&neigh->probes);
704
705         if (skb && ipv6_chk_addr(&skb->nh.ipv6h->saddr, dev, 1))
706                 saddr = &skb->nh.ipv6h->saddr;
707
708         if ((probes -= neigh->parms->ucast_probes) < 0) {
709                 if (!(neigh->nud_state & NUD_VALID)) {
710                         ND_PRINTK1(KERN_DEBUG
711                                    "%s(): trying to ucast probe in NUD_INVALID: "
712                                    NIP6_FMT "\n",
713                                    __FUNCTION__,
714                                    NIP6(*target));
715                 }
716                 ndisc_send_ns(dev, neigh, target, target, saddr);
717         } else if ((probes -= neigh->parms->app_probes) < 0) {
718 #ifdef CONFIG_ARPD
719                 neigh_app_ns(neigh);
720 #endif
721         } else {
722                 addrconf_addr_solict_mult(target, &mcaddr);
723                 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
724         }
725 }
726
727 static void ndisc_recv_ns(struct sk_buff *skb)
728 {
729         struct nd_msg *msg = (struct nd_msg *)skb->h.raw;
730         struct in6_addr *saddr = &skb->nh.ipv6h->saddr;
731         struct in6_addr *daddr = &skb->nh.ipv6h->daddr;
732         u8 *lladdr = NULL;
733         u32 ndoptlen = skb->tail - msg->opt;
734         struct ndisc_options ndopts;
735         struct net_device *dev = skb->dev;
736         struct inet6_ifaddr *ifp;
737         struct inet6_dev *idev = NULL;
738         struct neighbour *neigh;
739         struct pneigh_entry *pneigh = NULL;
740         int dad = ipv6_addr_any(saddr);
741         int inc;
742         int is_router;
743
744         if (ipv6_addr_is_multicast(&msg->target)) {
745                 ND_PRINTK2(KERN_WARNING 
746                            "ICMPv6 NS: multicast target address");
747                 return;
748         }
749
750         /*
751          * RFC2461 7.1.1:
752          * DAD has to be destined for solicited node multicast address.
753          */
754         if (dad &&
755             !(daddr->s6_addr32[0] == htonl(0xff020000) &&
756               daddr->s6_addr32[1] == htonl(0x00000000) &&
757               daddr->s6_addr32[2] == htonl(0x00000001) &&
758               daddr->s6_addr [12] == 0xff )) {
759                 ND_PRINTK2(KERN_WARNING
760                            "ICMPv6 NS: bad DAD packet (wrong destination)\n");
761                 return;
762         }
763
764         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
765                 ND_PRINTK2(KERN_WARNING 
766                            "ICMPv6 NS: invalid ND options\n");
767                 return;
768         }
769
770         if (ndopts.nd_opts_src_lladdr) {
771                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
772                 if (!lladdr) {
773                         ND_PRINTK2(KERN_WARNING
774                                    "ICMPv6 NS: invalid link-layer address length\n");
775                         return;
776                 }
777
778                 /* RFC2461 7.1.1:
779                  *      If the IP source address is the unspecified address, 
780                  *      there MUST NOT be source link-layer address option 
781                  *      in the message.
782                  */
783                 if (dad) {
784                         ND_PRINTK2(KERN_WARNING 
785                                    "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
786                         return;
787                 }
788         }
789
790         inc = ipv6_addr_is_multicast(daddr);
791
792         if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1)) != NULL) {
793                 if (ifp->flags & IFA_F_TENTATIVE) {
794                         /* Address is tentative. If the source
795                            is unspecified address, it is someone
796                            does DAD, otherwise we ignore solicitations
797                            until DAD timer expires.
798                          */
799                         if (!dad)
800                                 goto out;
801                         if (dev->type == ARPHRD_IEEE802_TR) {
802                                 unsigned char *sadr = skb->mac.raw;
803                                 if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
804                                     sadr[9] == dev->dev_addr[1] &&
805                                     sadr[10] == dev->dev_addr[2] &&
806                                     sadr[11] == dev->dev_addr[3] &&
807                                     sadr[12] == dev->dev_addr[4] &&
808                                     sadr[13] == dev->dev_addr[5]) {
809                                         /* looped-back to us */
810                                         goto out;
811                                 }
812                         }
813                         addrconf_dad_failure(ifp); 
814                         return;
815                 }
816
817                 idev = ifp->idev;
818         } else {
819                 idev = in6_dev_get(dev);
820                 if (!idev) {
821                         /* XXX: count this drop? */
822                         return;
823                 }
824
825                 if (ipv6_chk_acast_addr(dev, &msg->target) ||
826                     (idev->cnf.forwarding && 
827                      (ipv6_devconf.proxy_ndp || idev->cnf.proxy_ndp) &&
828                      (pneigh = pneigh_lookup(&nd_tbl,
829                                              &msg->target, dev, 0)) != NULL)) {
830                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
831                             skb->pkt_type != PACKET_HOST &&
832                             inc != 0 &&
833                             idev->nd_parms->proxy_delay != 0) {
834                                 /*
835                                  * for anycast or proxy,
836                                  * sender should delay its response 
837                                  * by a random time between 0 and 
838                                  * MAX_ANYCAST_DELAY_TIME seconds.
839                                  * (RFC2461) -- yoshfuji
840                                  */
841                                 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
842                                 if (n)
843                                         pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
844                                 goto out;
845                         }
846                 } else
847                         goto out;
848         }
849
850         is_router = !!(pneigh ? pneigh->flags & NTF_ROUTER : idev->cnf.forwarding);
851
852         if (dad) {
853                 struct in6_addr maddr;
854
855                 ipv6_addr_all_nodes(&maddr);
856                 ndisc_send_na(dev, NULL, &maddr, &msg->target,
857                               is_router, 0, (ifp != NULL), 1);
858                 goto out;
859         }
860
861         if (inc)
862                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
863         else
864                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
865
866         /* 
867          *      update / create cache entry
868          *      for the source address
869          */
870         neigh = __neigh_lookup(&nd_tbl, saddr, dev,
871                                !inc || lladdr || !dev->addr_len);
872         if (neigh)
873                 neigh_update(neigh, lladdr, NUD_STALE, 
874                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
875                              NEIGH_UPDATE_F_OVERRIDE);
876         if (neigh || !dev->hard_header) {
877                 ndisc_send_na(dev, neigh, saddr, &msg->target,
878                               is_router,
879                               1, (ifp != NULL && inc), inc);
880                 if (neigh)
881                         neigh_release(neigh);
882         }
883
884 out:
885         if (ifp)
886                 in6_ifa_put(ifp);
887         else
888                 in6_dev_put(idev);
889
890         return;
891 }
892
893 static void ndisc_recv_na(struct sk_buff *skb)
894 {
895         struct nd_msg *msg = (struct nd_msg *)skb->h.raw;
896         struct in6_addr *saddr = &skb->nh.ipv6h->saddr;
897         struct in6_addr *daddr = &skb->nh.ipv6h->daddr;
898         u8 *lladdr = NULL;
899         u32 ndoptlen = skb->tail - msg->opt;
900         struct ndisc_options ndopts;
901         struct net_device *dev = skb->dev;
902         struct inet6_ifaddr *ifp;
903         struct neighbour *neigh;
904
905         if (skb->len < sizeof(struct nd_msg)) {
906                 ND_PRINTK2(KERN_WARNING
907                            "ICMPv6 NA: packet too short\n");
908                 return;
909         }
910
911         if (ipv6_addr_is_multicast(&msg->target)) {
912                 ND_PRINTK2(KERN_WARNING
913                            "ICMPv6 NA: target address is multicast.\n");
914                 return;
915         }
916
917         if (ipv6_addr_is_multicast(daddr) &&
918             msg->icmph.icmp6_solicited) {
919                 ND_PRINTK2(KERN_WARNING
920                            "ICMPv6 NA: solicited NA is multicasted.\n");
921                 return;
922         }
923                 
924         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
925                 ND_PRINTK2(KERN_WARNING
926                            "ICMPv6 NS: invalid ND option\n");
927                 return;
928         }
929         if (ndopts.nd_opts_tgt_lladdr) {
930                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
931                 if (!lladdr) {
932                         ND_PRINTK2(KERN_WARNING
933                                    "ICMPv6 NA: invalid link-layer address length\n");
934                         return;
935                 }
936         }
937         if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1))) {
938                 if (ifp->flags & IFA_F_TENTATIVE) {
939                         addrconf_dad_failure(ifp);
940                         return;
941                 }
942                 /* What should we make now? The advertisement
943                    is invalid, but ndisc specs say nothing
944                    about it. It could be misconfiguration, or
945                    an smart proxy agent tries to help us :-)
946                  */
947                 ND_PRINTK1(KERN_WARNING
948                            "ICMPv6 NA: someone advertises our address on %s!\n",
949                            ifp->idev->dev->name);
950                 in6_ifa_put(ifp);
951                 return;
952         }
953         neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
954
955         if (neigh) {
956                 u8 old_flags = neigh->flags;
957
958                 if (neigh->nud_state & NUD_FAILED)
959                         goto out;
960
961                 /*
962                  * Don't update the neighbor cache entry on a proxy NA from
963                  * ourselves because either the proxied node is off link or it
964                  * has already sent a NA to us.
965                  */
966                 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
967                     ipv6_devconf.forwarding && ipv6_devconf.proxy_ndp &&
968                     pneigh_lookup(&nd_tbl, &msg->target, dev, 0)) {
969                         /* XXX: idev->cnf.prixy_ndp */
970                         goto out;
971                 }
972
973                 neigh_update(neigh, lladdr,
974                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
975                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
976                              (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
977                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
978                              (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
979
980                 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
981                         /*
982                          * Change: router to host
983                          */
984                         struct rt6_info *rt;
985                         rt = rt6_get_dflt_router(saddr, dev);
986                         if (rt)
987                                 ip6_del_rt(rt);
988                 }
989
990 out:
991                 neigh_release(neigh);
992         }
993 }
994
995 static void ndisc_recv_rs(struct sk_buff *skb)
996 {
997         struct rs_msg *rs_msg = (struct rs_msg *) skb->h.raw;
998         unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
999         struct neighbour *neigh;
1000         struct inet6_dev *idev;
1001         struct in6_addr *saddr = &skb->nh.ipv6h->saddr;
1002         struct ndisc_options ndopts;
1003         u8 *lladdr = NULL;
1004
1005         if (skb->len < sizeof(*rs_msg))
1006                 return;
1007
1008         idev = in6_dev_get(skb->dev);
1009         if (!idev) {
1010                 if (net_ratelimit())
1011                         ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1012                 return;
1013         }
1014
1015         /* Don't accept RS if we're not in router mode */
1016         if (!idev->cnf.forwarding)
1017                 goto out;
1018
1019         /*
1020          * Don't update NCE if src = ::;
1021          * this implies that the source node has no ip address assigned yet.
1022          */
1023         if (ipv6_addr_any(saddr))
1024                 goto out;
1025
1026         /* Parse ND options */
1027         if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1028                 if (net_ratelimit())
1029                         ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1030                 goto out;
1031         }
1032
1033         if (ndopts.nd_opts_src_lladdr) {
1034                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1035                                              skb->dev);
1036                 if (!lladdr)
1037                         goto out;
1038         }
1039
1040         neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1041         if (neigh) {
1042                 neigh_update(neigh, lladdr, NUD_STALE,
1043                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1044                              NEIGH_UPDATE_F_OVERRIDE|
1045                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1046                 neigh_release(neigh);
1047         }
1048 out:
1049         in6_dev_put(idev);
1050 }
1051
1052 static void ndisc_router_discovery(struct sk_buff *skb)
1053 {
1054         struct ra_msg *ra_msg = (struct ra_msg *) skb->h.raw;
1055         struct neighbour *neigh = NULL;
1056         struct inet6_dev *in6_dev;
1057         struct rt6_info *rt = NULL;
1058         int lifetime;
1059         struct ndisc_options ndopts;
1060         int optlen;
1061         unsigned int pref = 0;
1062
1063         __u8 * opt = (__u8 *)(ra_msg + 1);
1064
1065         optlen = (skb->tail - skb->h.raw) - sizeof(struct ra_msg);
1066
1067         if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
1068                 ND_PRINTK2(KERN_WARNING
1069                            "ICMPv6 RA: source address is not link-local.\n");
1070                 return;
1071         }
1072         if (optlen < 0) {
1073                 ND_PRINTK2(KERN_WARNING 
1074                            "ICMPv6 RA: packet too short\n");
1075                 return;
1076         }
1077
1078         /*
1079          *      set the RA_RECV flag in the interface
1080          */
1081
1082         in6_dev = in6_dev_get(skb->dev);
1083         if (in6_dev == NULL) {
1084                 ND_PRINTK0(KERN_ERR
1085                            "ICMPv6 RA: can't find inet6 device for %s.\n",
1086                            skb->dev->name);
1087                 return;
1088         }
1089         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) {
1090                 in6_dev_put(in6_dev);
1091                 return;
1092         }
1093
1094         if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1095                 in6_dev_put(in6_dev);
1096                 ND_PRINTK2(KERN_WARNING
1097                            "ICMP6 RA: invalid ND options\n");
1098                 return;
1099         }
1100
1101         if (in6_dev->if_flags & IF_RS_SENT) {
1102                 /*
1103                  *      flag that an RA was received after an RS was sent
1104                  *      out on this interface.
1105                  */
1106                 in6_dev->if_flags |= IF_RA_RCVD;
1107         }
1108
1109         /*
1110          * Remember the managed/otherconf flags from most recently
1111          * received RA message (RFC 2462) -- yoshfuji
1112          */
1113         in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1114                                 IF_RA_OTHERCONF)) |
1115                                 (ra_msg->icmph.icmp6_addrconf_managed ?
1116                                         IF_RA_MANAGED : 0) |
1117                                 (ra_msg->icmph.icmp6_addrconf_other ?
1118                                         IF_RA_OTHERCONF : 0);
1119
1120         if (!in6_dev->cnf.accept_ra_defrtr)
1121                 goto skip_defrtr;
1122
1123         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1124
1125 #ifdef CONFIG_IPV6_ROUTER_PREF
1126         pref = ra_msg->icmph.icmp6_router_pref;
1127         /* 10b is handled as if it were 00b (medium) */
1128         if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1129             in6_dev->cnf.accept_ra_rtr_pref)
1130                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1131 #endif
1132
1133         rt = rt6_get_dflt_router(&skb->nh.ipv6h->saddr, skb->dev);
1134
1135         if (rt)
1136                 neigh = rt->rt6i_nexthop;
1137
1138         if (rt && lifetime == 0) {
1139                 neigh_clone(neigh);
1140                 ip6_del_rt(rt);
1141                 rt = NULL;
1142         }
1143
1144         if (rt == NULL && lifetime) {
1145                 ND_PRINTK3(KERN_DEBUG
1146                            "ICMPv6 RA: adding default router.\n");
1147
1148                 rt = rt6_add_dflt_router(&skb->nh.ipv6h->saddr, skb->dev, pref);
1149                 if (rt == NULL) {
1150                         ND_PRINTK0(KERN_ERR
1151                                    "ICMPv6 RA: %s() failed to add default route.\n",
1152                                    __FUNCTION__);
1153                         in6_dev_put(in6_dev);
1154                         return;
1155                 }
1156
1157                 neigh = rt->rt6i_nexthop;
1158                 if (neigh == NULL) {
1159                         ND_PRINTK0(KERN_ERR
1160                                    "ICMPv6 RA: %s() got default router without neighbour.\n",
1161                                    __FUNCTION__);
1162                         dst_release(&rt->u.dst);
1163                         in6_dev_put(in6_dev);
1164                         return;
1165                 }
1166                 neigh->flags |= NTF_ROUTER;
1167         } else if (rt) {
1168                 rt->rt6i_flags |= (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1169         }
1170
1171         if (rt)
1172                 rt->rt6i_expires = jiffies + (HZ * lifetime);
1173
1174         if (ra_msg->icmph.icmp6_hop_limit) {
1175                 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1176                 if (rt)
1177                         rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit;
1178         }
1179
1180 skip_defrtr:
1181
1182         /*
1183          *      Update Reachable Time and Retrans Timer
1184          */
1185
1186         if (in6_dev->nd_parms) {
1187                 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1188
1189                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1190                         rtime = (rtime*HZ)/1000;
1191                         if (rtime < HZ/10)
1192                                 rtime = HZ/10;
1193                         in6_dev->nd_parms->retrans_time = rtime;
1194                         in6_dev->tstamp = jiffies;
1195                         inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1196                 }
1197
1198                 rtime = ntohl(ra_msg->reachable_time);
1199                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1200                         rtime = (rtime*HZ)/1000;
1201
1202                         if (rtime < HZ/10)
1203                                 rtime = HZ/10;
1204
1205                         if (rtime != in6_dev->nd_parms->base_reachable_time) {
1206                                 in6_dev->nd_parms->base_reachable_time = rtime;
1207                                 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1208                                 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1209                                 in6_dev->tstamp = jiffies;
1210                                 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1211                         }
1212                 }
1213         }
1214
1215         /*
1216          *      Process options.
1217          */
1218
1219         if (!neigh)
1220                 neigh = __neigh_lookup(&nd_tbl, &skb->nh.ipv6h->saddr,
1221                                        skb->dev, 1);
1222         if (neigh) {
1223                 u8 *lladdr = NULL;
1224                 if (ndopts.nd_opts_src_lladdr) {
1225                         lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1226                                                      skb->dev);
1227                         if (!lladdr) {
1228                                 ND_PRINTK2(KERN_WARNING
1229                                            "ICMPv6 RA: invalid link-layer address length\n");
1230                                 goto out;
1231                         }
1232                 }
1233                 neigh_update(neigh, lladdr, NUD_STALE,
1234                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1235                              NEIGH_UPDATE_F_OVERRIDE|
1236                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1237                              NEIGH_UPDATE_F_ISROUTER);
1238         }
1239
1240 #ifdef CONFIG_IPV6_ROUTE_INFO
1241         if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1242                 struct nd_opt_hdr *p;
1243                 for (p = ndopts.nd_opts_ri;
1244                      p;
1245                      p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1246                         if (((struct route_info *)p)->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1247                                 continue;
1248                         rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1249                                       &skb->nh.ipv6h->saddr);
1250                 }
1251         }
1252 #endif
1253
1254         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1255                 struct nd_opt_hdr *p;
1256                 for (p = ndopts.nd_opts_pi;
1257                      p;
1258                      p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1259                         addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
1260                 }
1261         }
1262
1263         if (ndopts.nd_opts_mtu) {
1264                 u32 mtu;
1265
1266                 memcpy(&mtu, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1267                 mtu = ntohl(mtu);
1268
1269                 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1270                         ND_PRINTK2(KERN_WARNING
1271                                    "ICMPv6 RA: invalid mtu: %d\n",
1272                                    mtu);
1273                 } else if (in6_dev->cnf.mtu6 != mtu) {
1274                         in6_dev->cnf.mtu6 = mtu;
1275
1276                         if (rt)
1277                                 rt->u.dst.metrics[RTAX_MTU-1] = mtu;
1278
1279                         rt6_mtu_change(skb->dev, mtu);
1280                 }
1281         }
1282                         
1283         if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1284                 ND_PRINTK2(KERN_WARNING
1285                            "ICMPv6 RA: invalid RA options");
1286         }
1287 out:
1288         if (rt)
1289                 dst_release(&rt->u.dst);
1290         else if (neigh)
1291                 neigh_release(neigh);
1292         in6_dev_put(in6_dev);
1293 }
1294
1295 static void ndisc_redirect_rcv(struct sk_buff *skb)
1296 {
1297         struct inet6_dev *in6_dev;
1298         struct icmp6hdr *icmph;
1299         struct in6_addr *dest;
1300         struct in6_addr *target;        /* new first hop to destination */
1301         struct neighbour *neigh;
1302         int on_link = 0;
1303         struct ndisc_options ndopts;
1304         int optlen;
1305         u8 *lladdr = NULL;
1306
1307         if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
1308                 ND_PRINTK2(KERN_WARNING
1309                            "ICMPv6 Redirect: source address is not link-local.\n");
1310                 return;
1311         }
1312
1313         optlen = skb->tail - skb->h.raw;
1314         optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1315
1316         if (optlen < 0) {
1317                 ND_PRINTK2(KERN_WARNING
1318                            "ICMPv6 Redirect: packet too short\n");
1319                 return;
1320         }
1321
1322         icmph = (struct icmp6hdr *) skb->h.raw;
1323         target = (struct in6_addr *) (icmph + 1);
1324         dest = target + 1;
1325
1326         if (ipv6_addr_is_multicast(dest)) {
1327                 ND_PRINTK2(KERN_WARNING
1328                            "ICMPv6 Redirect: destination address is multicast.\n");
1329                 return;
1330         }
1331
1332         if (ipv6_addr_equal(dest, target)) {
1333                 on_link = 1;
1334         } else if (!(ipv6_addr_type(target) & IPV6_ADDR_LINKLOCAL)) {
1335                 ND_PRINTK2(KERN_WARNING 
1336                            "ICMPv6 Redirect: target address is not link-local.\n");
1337                 return;
1338         }
1339
1340         in6_dev = in6_dev_get(skb->dev);
1341         if (!in6_dev)
1342                 return;
1343         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1344                 in6_dev_put(in6_dev);
1345                 return;
1346         }
1347
1348         /* RFC2461 8.1: 
1349          *      The IP source address of the Redirect MUST be the same as the current
1350          *      first-hop router for the specified ICMP Destination Address.
1351          */
1352                 
1353         if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1354                 ND_PRINTK2(KERN_WARNING
1355                            "ICMPv6 Redirect: invalid ND options\n");
1356                 in6_dev_put(in6_dev);
1357                 return;
1358         }
1359         if (ndopts.nd_opts_tgt_lladdr) {
1360                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1361                                              skb->dev);
1362                 if (!lladdr) {
1363                         ND_PRINTK2(KERN_WARNING
1364                                    "ICMPv6 Redirect: invalid link-layer address length\n");
1365                         in6_dev_put(in6_dev);
1366                         return;
1367                 }
1368         }
1369
1370         neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1371         if (neigh) {
1372                 rt6_redirect(dest, &skb->nh.ipv6h->daddr,
1373                              &skb->nh.ipv6h->saddr, neigh, lladdr,
1374                              on_link);
1375                 neigh_release(neigh);
1376         }
1377         in6_dev_put(in6_dev);
1378 }
1379
1380 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1381                          struct in6_addr *target)
1382 {
1383         struct sock *sk = ndisc_socket->sk;
1384         int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1385         struct sk_buff *buff;
1386         struct icmp6hdr *icmph;
1387         struct in6_addr saddr_buf;
1388         struct in6_addr *addrp;
1389         struct net_device *dev;
1390         struct rt6_info *rt;
1391         struct dst_entry *dst;
1392         struct inet6_dev *idev;
1393         struct flowi fl;
1394         u8 *opt;
1395         int rd_len;
1396         int err;
1397         int hlen;
1398         u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1399
1400         dev = skb->dev;
1401
1402         if (ipv6_get_lladdr(dev, &saddr_buf)) {
1403                 ND_PRINTK2(KERN_WARNING
1404                            "ICMPv6 Redirect: no link-local address on %s\n",
1405                            dev->name);
1406                 return;
1407         }
1408
1409         ndisc_flow_init(&fl, NDISC_REDIRECT, &saddr_buf, &skb->nh.ipv6h->saddr,
1410                         dev->ifindex);
1411
1412         dst = ip6_route_output(NULL, &fl);
1413         if (dst == NULL)
1414                 return;
1415
1416         err = xfrm_lookup(&dst, &fl, NULL, 0);
1417         if (err)
1418                 return;
1419
1420         rt = (struct rt6_info *) dst;
1421
1422         if (rt->rt6i_flags & RTF_GATEWAY) {
1423                 ND_PRINTK2(KERN_WARNING
1424                            "ICMPv6 Redirect: destination is not a neighbour.\n");
1425                 dst_release(dst);
1426                 return;
1427         }
1428         if (!xrlim_allow(dst, 1*HZ)) {
1429                 dst_release(dst);
1430                 return;
1431         }
1432
1433         if (dev->addr_len) {
1434                 read_lock_bh(&neigh->lock);
1435                 if (neigh->nud_state & NUD_VALID) {
1436                         memcpy(ha_buf, neigh->ha, dev->addr_len);
1437                         read_unlock_bh(&neigh->lock);
1438                         ha = ha_buf;
1439                         len += ndisc_opt_addr_space(dev);
1440                 } else
1441                         read_unlock_bh(&neigh->lock);
1442         }
1443
1444         rd_len = min_t(unsigned int,
1445                      IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1446         rd_len &= ~0x7;
1447         len += rd_len;
1448
1449         buff = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
1450                                    1, &err);
1451         if (buff == NULL) {
1452                 ND_PRINTK0(KERN_ERR
1453                            "ICMPv6 Redirect: %s() failed to allocate an skb.\n",
1454                            __FUNCTION__);
1455                 dst_release(dst);
1456                 return;
1457         }
1458
1459         hlen = 0;
1460
1461         skb_reserve(buff, LL_RESERVED_SPACE(dev));
1462         ip6_nd_hdr(sk, buff, dev, &saddr_buf, &skb->nh.ipv6h->saddr,
1463                    IPPROTO_ICMPV6, len);
1464
1465         icmph = (struct icmp6hdr *)skb_put(buff, len);
1466         buff->h.raw = (unsigned char*)icmph;
1467
1468         memset(icmph, 0, sizeof(struct icmp6hdr));
1469         icmph->icmp6_type = NDISC_REDIRECT;
1470
1471         /*
1472          *      copy target and destination addresses
1473          */
1474
1475         addrp = (struct in6_addr *)(icmph + 1);
1476         ipv6_addr_copy(addrp, target);
1477         addrp++;
1478         ipv6_addr_copy(addrp, &skb->nh.ipv6h->daddr);
1479
1480         opt = (u8*) (addrp + 1);
1481
1482         /*
1483          *      include target_address option
1484          */
1485
1486         if (ha)
1487                 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1488                                              dev->addr_len, dev->type);
1489
1490         /*
1491          *      build redirect option and copy skb over to the new packet.
1492          */
1493
1494         memset(opt, 0, 8);      
1495         *(opt++) = ND_OPT_REDIRECT_HDR;
1496         *(opt++) = (rd_len >> 3);
1497         opt += 6;
1498
1499         memcpy(opt, skb->nh.ipv6h, rd_len - 8);
1500
1501         icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &skb->nh.ipv6h->saddr,
1502                                              len, IPPROTO_ICMPV6,
1503                                              csum_partial((u8 *) icmph, len, 0));
1504
1505         buff->dst = dst;
1506         idev = in6_dev_get(dst->dev);
1507         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
1508         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, buff, NULL, dst->dev, dst_output);
1509         if (!err) {
1510                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTREDIRECTS);
1511                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
1512         }
1513
1514         if (likely(idev != NULL))
1515                 in6_dev_put(idev);
1516 }
1517
1518 static void pndisc_redo(struct sk_buff *skb)
1519 {
1520         ndisc_recv_ns(skb);
1521         kfree_skb(skb);
1522 }
1523
1524 int ndisc_rcv(struct sk_buff *skb)
1525 {
1526         struct nd_msg *msg;
1527
1528         if (!pskb_may_pull(skb, skb->len))
1529                 return 0;
1530
1531         msg = (struct nd_msg *) skb->h.raw;
1532
1533         __skb_push(skb, skb->data-skb->h.raw);
1534
1535         if (skb->nh.ipv6h->hop_limit != 255) {
1536                 ND_PRINTK2(KERN_WARNING
1537                            "ICMPv6 NDISC: invalid hop-limit: %d\n",
1538                            skb->nh.ipv6h->hop_limit);
1539                 return 0;
1540         }
1541
1542         if (msg->icmph.icmp6_code != 0) {
1543                 ND_PRINTK2(KERN_WARNING 
1544                            "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1545                            msg->icmph.icmp6_code);
1546                 return 0;
1547         }
1548
1549         memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1550
1551         switch (msg->icmph.icmp6_type) {
1552         case NDISC_NEIGHBOUR_SOLICITATION:
1553                 ndisc_recv_ns(skb);
1554                 break;
1555
1556         case NDISC_NEIGHBOUR_ADVERTISEMENT:
1557                 ndisc_recv_na(skb);
1558                 break;
1559
1560         case NDISC_ROUTER_SOLICITATION:
1561                 ndisc_recv_rs(skb);
1562                 break;
1563
1564         case NDISC_ROUTER_ADVERTISEMENT:
1565                 ndisc_router_discovery(skb);
1566                 break;
1567
1568         case NDISC_REDIRECT:
1569                 ndisc_redirect_rcv(skb);
1570                 break;
1571         };
1572
1573         return 0;
1574 }
1575
1576 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1577 {
1578         struct net_device *dev = ptr;
1579
1580         switch (event) {
1581         case NETDEV_CHANGEADDR:
1582                 neigh_changeaddr(&nd_tbl, dev);
1583                 fib6_run_gc(~0UL);
1584                 break;
1585         case NETDEV_DOWN:
1586                 neigh_ifdown(&nd_tbl, dev);
1587                 fib6_run_gc(~0UL);
1588                 break;
1589         default:
1590                 break;
1591         }
1592
1593         return NOTIFY_DONE;
1594 }
1595
1596 static struct notifier_block ndisc_netdev_notifier = {
1597         .notifier_call = ndisc_netdev_event,
1598 };
1599
1600 #ifdef CONFIG_SYSCTL
1601 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1602                                          const char *func, const char *dev_name)
1603 {
1604         static char warncomm[TASK_COMM_LEN];
1605         static int warned;
1606         if (strcmp(warncomm, current->comm) && warned < 5) {
1607                 strcpy(warncomm, current->comm);
1608                 printk(KERN_WARNING
1609                         "process `%s' is using deprecated sysctl (%s) "
1610                         "net.ipv6.neigh.%s.%s; "
1611                         "Use net.ipv6.neigh.%s.%s_ms "
1612                         "instead.\n",
1613                         warncomm, func,
1614                         dev_name, ctl->procname,
1615                         dev_name, ctl->procname);
1616                 warned++;
1617         }
1618 }
1619
1620 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, struct file * filp, void __user *buffer, size_t *lenp, loff_t *ppos)
1621 {
1622         struct net_device *dev = ctl->extra1;
1623         struct inet6_dev *idev;
1624         int ret;
1625
1626         if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
1627             ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
1628                 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1629
1630         switch (ctl->ctl_name) {
1631         case NET_NEIGH_RETRANS_TIME:
1632                 ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
1633                 break;
1634         case NET_NEIGH_REACHABLE_TIME:
1635                 ret = proc_dointvec_jiffies(ctl, write,
1636                                             filp, buffer, lenp, ppos);
1637                 break;
1638         case NET_NEIGH_RETRANS_TIME_MS:
1639         case NET_NEIGH_REACHABLE_TIME_MS:
1640                 ret = proc_dointvec_ms_jiffies(ctl, write,
1641                                                filp, buffer, lenp, ppos);
1642                 break;
1643         default:
1644                 ret = -1;
1645         }
1646
1647         if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1648                 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
1649                     ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
1650                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1651                 idev->tstamp = jiffies;
1652                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1653                 in6_dev_put(idev);
1654         }
1655         return ret;
1656 }
1657
1658 static int ndisc_ifinfo_sysctl_strategy(ctl_table *ctl, int __user *name,
1659                                         int nlen, void __user *oldval,
1660                                         size_t __user *oldlenp,
1661                                         void __user *newval, size_t newlen,
1662                                         void **context)
1663 {
1664         struct net_device *dev = ctl->extra1;
1665         struct inet6_dev *idev;
1666         int ret;
1667
1668         if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
1669             ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
1670                 ndisc_warn_deprecated_sysctl(ctl, "procfs", dev ? dev->name : "default");
1671
1672         switch (ctl->ctl_name) {
1673         case NET_NEIGH_REACHABLE_TIME:
1674                 ret = sysctl_jiffies(ctl, name, nlen,
1675                                      oldval, oldlenp, newval, newlen,
1676                                      context);
1677                 break;
1678         case NET_NEIGH_RETRANS_TIME_MS:
1679         case NET_NEIGH_REACHABLE_TIME_MS:
1680                  ret = sysctl_ms_jiffies(ctl, name, nlen,
1681                                          oldval, oldlenp, newval, newlen,
1682                                          context);
1683                  break;
1684         default:
1685                 ret = 0;
1686         }
1687
1688         if (newval && newlen && ret > 0 &&
1689             dev && (idev = in6_dev_get(dev)) != NULL) {
1690                 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
1691                     ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
1692                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1693                 idev->tstamp = jiffies;
1694                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1695                 in6_dev_put(idev);
1696         }
1697
1698         return ret;
1699 }
1700
1701 #endif
1702
1703 int __init ndisc_init(struct net_proto_family *ops)
1704 {
1705         struct ipv6_pinfo *np;
1706         struct sock *sk;
1707         int err;
1708
1709         err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, &ndisc_socket);
1710         if (err < 0) {
1711                 ND_PRINTK0(KERN_ERR
1712                            "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n", 
1713                            err);
1714                 ndisc_socket = NULL; /* For safety. */
1715                 return err;
1716         }
1717
1718         sk = ndisc_socket->sk;
1719         np = inet6_sk(sk);
1720         sk->sk_allocation = GFP_ATOMIC;
1721         np->hop_limit = 255;
1722         /* Do not loopback ndisc messages */
1723         np->mc_loop = 0;
1724         sk->sk_prot->unhash(sk);
1725
1726         /*
1727          * Initialize the neighbour table
1728          */
1729         
1730         neigh_table_init(&nd_tbl);
1731
1732 #ifdef CONFIG_SYSCTL
1733         neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6, NET_IPV6_NEIGH, 
1734                               "ipv6",
1735                               &ndisc_ifinfo_sysctl_change,
1736                               &ndisc_ifinfo_sysctl_strategy);
1737 #endif
1738
1739         register_netdevice_notifier(&ndisc_netdev_notifier);
1740         return 0;
1741 }
1742
1743 void ndisc_cleanup(void)
1744 {
1745         unregister_netdevice_notifier(&ndisc_netdev_notifier);
1746 #ifdef CONFIG_SYSCTL
1747         neigh_sysctl_unregister(&nd_tbl.parms);
1748 #endif
1749         neigh_table_clear(&nd_tbl);
1750         sock_release(ndisc_socket);
1751         ndisc_socket = NULL; /* For safety. */
1752 }