[IPV6] NDISC: Initialize fl with outbound interface to lookup rules properly.
[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         int dad = ipv6_addr_any(saddr);
740         int inc;
741
742         if (ipv6_addr_is_multicast(&msg->target)) {
743                 ND_PRINTK2(KERN_WARNING 
744                            "ICMPv6 NS: multicast target address");
745                 return;
746         }
747
748         /*
749          * RFC2461 7.1.1:
750          * DAD has to be destined for solicited node multicast address.
751          */
752         if (dad &&
753             !(daddr->s6_addr32[0] == htonl(0xff020000) &&
754               daddr->s6_addr32[1] == htonl(0x00000000) &&
755               daddr->s6_addr32[2] == htonl(0x00000001) &&
756               daddr->s6_addr [12] == 0xff )) {
757                 ND_PRINTK2(KERN_WARNING
758                            "ICMPv6 NS: bad DAD packet (wrong destination)\n");
759                 return;
760         }
761
762         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
763                 ND_PRINTK2(KERN_WARNING 
764                            "ICMPv6 NS: invalid ND options\n");
765                 return;
766         }
767
768         if (ndopts.nd_opts_src_lladdr) {
769                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
770                 if (!lladdr) {
771                         ND_PRINTK2(KERN_WARNING
772                                    "ICMPv6 NS: invalid link-layer address length\n");
773                         return;
774                 }
775
776                 /* RFC2461 7.1.1:
777                  *      If the IP source address is the unspecified address, 
778                  *      there MUST NOT be source link-layer address option 
779                  *      in the message.
780                  */
781                 if (dad) {
782                         ND_PRINTK2(KERN_WARNING 
783                                    "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
784                         return;
785                 }
786         }
787
788         inc = ipv6_addr_is_multicast(daddr);
789
790         if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1)) != NULL) {
791                 if (ifp->flags & IFA_F_TENTATIVE) {
792                         /* Address is tentative. If the source
793                            is unspecified address, it is someone
794                            does DAD, otherwise we ignore solicitations
795                            until DAD timer expires.
796                          */
797                         if (!dad)
798                                 goto out;
799                         if (dev->type == ARPHRD_IEEE802_TR) {
800                                 unsigned char *sadr = skb->mac.raw;
801                                 if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
802                                     sadr[9] == dev->dev_addr[1] &&
803                                     sadr[10] == dev->dev_addr[2] &&
804                                     sadr[11] == dev->dev_addr[3] &&
805                                     sadr[12] == dev->dev_addr[4] &&
806                                     sadr[13] == dev->dev_addr[5]) {
807                                         /* looped-back to us */
808                                         goto out;
809                                 }
810                         }
811                         addrconf_dad_failure(ifp); 
812                         return;
813                 }
814
815                 idev = ifp->idev;
816         } else {
817                 idev = in6_dev_get(dev);
818                 if (!idev) {
819                         /* XXX: count this drop? */
820                         return;
821                 }
822
823                 if (ipv6_chk_acast_addr(dev, &msg->target) ||
824                     (idev->cnf.forwarding && 
825                      pneigh_lookup(&nd_tbl, &msg->target, dev, 0))) {
826                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
827                             skb->pkt_type != PACKET_HOST &&
828                             inc != 0 &&
829                             idev->nd_parms->proxy_delay != 0) {
830                                 /*
831                                  * for anycast or proxy,
832                                  * sender should delay its response 
833                                  * by a random time between 0 and 
834                                  * MAX_ANYCAST_DELAY_TIME seconds.
835                                  * (RFC2461) -- yoshfuji
836                                  */
837                                 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
838                                 if (n)
839                                         pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
840                                 goto out;
841                         }
842                 } else
843                         goto out;
844         }
845
846         if (dad) {
847                 struct in6_addr maddr;
848
849                 ipv6_addr_all_nodes(&maddr);
850                 ndisc_send_na(dev, NULL, &maddr, &msg->target,
851                               idev->cnf.forwarding, 0, (ifp != NULL), 1);
852                 goto out;
853         }
854
855         if (inc)
856                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
857         else
858                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
859
860         /* 
861          *      update / create cache entry
862          *      for the source address
863          */
864         neigh = __neigh_lookup(&nd_tbl, saddr, dev,
865                                !inc || lladdr || !dev->addr_len);
866         if (neigh)
867                 neigh_update(neigh, lladdr, NUD_STALE, 
868                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
869                              NEIGH_UPDATE_F_OVERRIDE);
870         if (neigh || !dev->hard_header) {
871                 ndisc_send_na(dev, neigh, saddr, &msg->target,
872                               idev->cnf.forwarding, 
873                               1, (ifp != NULL && inc), inc);
874                 if (neigh)
875                         neigh_release(neigh);
876         }
877
878 out:
879         if (ifp)
880                 in6_ifa_put(ifp);
881         else
882                 in6_dev_put(idev);
883
884         return;
885 }
886
887 static void ndisc_recv_na(struct sk_buff *skb)
888 {
889         struct nd_msg *msg = (struct nd_msg *)skb->h.raw;
890         struct in6_addr *saddr = &skb->nh.ipv6h->saddr;
891         struct in6_addr *daddr = &skb->nh.ipv6h->daddr;
892         u8 *lladdr = NULL;
893         u32 ndoptlen = skb->tail - msg->opt;
894         struct ndisc_options ndopts;
895         struct net_device *dev = skb->dev;
896         struct inet6_ifaddr *ifp;
897         struct neighbour *neigh;
898
899         if (skb->len < sizeof(struct nd_msg)) {
900                 ND_PRINTK2(KERN_WARNING
901                            "ICMPv6 NA: packet too short\n");
902                 return;
903         }
904
905         if (ipv6_addr_is_multicast(&msg->target)) {
906                 ND_PRINTK2(KERN_WARNING
907                            "ICMPv6 NA: target address is multicast.\n");
908                 return;
909         }
910
911         if (ipv6_addr_is_multicast(daddr) &&
912             msg->icmph.icmp6_solicited) {
913                 ND_PRINTK2(KERN_WARNING
914                            "ICMPv6 NA: solicited NA is multicasted.\n");
915                 return;
916         }
917                 
918         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
919                 ND_PRINTK2(KERN_WARNING
920                            "ICMPv6 NS: invalid ND option\n");
921                 return;
922         }
923         if (ndopts.nd_opts_tgt_lladdr) {
924                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
925                 if (!lladdr) {
926                         ND_PRINTK2(KERN_WARNING
927                                    "ICMPv6 NA: invalid link-layer address length\n");
928                         return;
929                 }
930         }
931         if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1))) {
932                 if (ifp->flags & IFA_F_TENTATIVE) {
933                         addrconf_dad_failure(ifp);
934                         return;
935                 }
936                 /* What should we make now? The advertisement
937                    is invalid, but ndisc specs say nothing
938                    about it. It could be misconfiguration, or
939                    an smart proxy agent tries to help us :-)
940                  */
941                 ND_PRINTK1(KERN_WARNING
942                            "ICMPv6 NA: someone advertises our address on %s!\n",
943                            ifp->idev->dev->name);
944                 in6_ifa_put(ifp);
945                 return;
946         }
947         neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
948
949         if (neigh) {
950                 u8 old_flags = neigh->flags;
951
952                 if (neigh->nud_state & NUD_FAILED)
953                         goto out;
954
955                 neigh_update(neigh, lladdr,
956                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
957                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
958                              (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
959                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
960                              (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
961
962                 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
963                         /*
964                          * Change: router to host
965                          */
966                         struct rt6_info *rt;
967                         rt = rt6_get_dflt_router(saddr, dev);
968                         if (rt)
969                                 ip6_del_rt(rt);
970                 }
971
972 out:
973                 neigh_release(neigh);
974         }
975 }
976
977 static void ndisc_recv_rs(struct sk_buff *skb)
978 {
979         struct rs_msg *rs_msg = (struct rs_msg *) skb->h.raw;
980         unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
981         struct neighbour *neigh;
982         struct inet6_dev *idev;
983         struct in6_addr *saddr = &skb->nh.ipv6h->saddr;
984         struct ndisc_options ndopts;
985         u8 *lladdr = NULL;
986
987         if (skb->len < sizeof(*rs_msg))
988                 return;
989
990         idev = in6_dev_get(skb->dev);
991         if (!idev) {
992                 if (net_ratelimit())
993                         ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
994                 return;
995         }
996
997         /* Don't accept RS if we're not in router mode */
998         if (!idev->cnf.forwarding)
999                 goto out;
1000
1001         /*
1002          * Don't update NCE if src = ::;
1003          * this implies that the source node has no ip address assigned yet.
1004          */
1005         if (ipv6_addr_any(saddr))
1006                 goto out;
1007
1008         /* Parse ND options */
1009         if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1010                 if (net_ratelimit())
1011                         ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1012                 goto out;
1013         }
1014
1015         if (ndopts.nd_opts_src_lladdr) {
1016                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1017                                              skb->dev);
1018                 if (!lladdr)
1019                         goto out;
1020         }
1021
1022         neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1023         if (neigh) {
1024                 neigh_update(neigh, lladdr, NUD_STALE,
1025                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1026                              NEIGH_UPDATE_F_OVERRIDE|
1027                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1028                 neigh_release(neigh);
1029         }
1030 out:
1031         in6_dev_put(idev);
1032 }
1033
1034 static void ndisc_router_discovery(struct sk_buff *skb)
1035 {
1036         struct ra_msg *ra_msg = (struct ra_msg *) skb->h.raw;
1037         struct neighbour *neigh = NULL;
1038         struct inet6_dev *in6_dev;
1039         struct rt6_info *rt = NULL;
1040         int lifetime;
1041         struct ndisc_options ndopts;
1042         int optlen;
1043         unsigned int pref = 0;
1044
1045         __u8 * opt = (__u8 *)(ra_msg + 1);
1046
1047         optlen = (skb->tail - skb->h.raw) - sizeof(struct ra_msg);
1048
1049         if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
1050                 ND_PRINTK2(KERN_WARNING
1051                            "ICMPv6 RA: source address is not link-local.\n");
1052                 return;
1053         }
1054         if (optlen < 0) {
1055                 ND_PRINTK2(KERN_WARNING 
1056                            "ICMPv6 RA: packet too short\n");
1057                 return;
1058         }
1059
1060         /*
1061          *      set the RA_RECV flag in the interface
1062          */
1063
1064         in6_dev = in6_dev_get(skb->dev);
1065         if (in6_dev == NULL) {
1066                 ND_PRINTK0(KERN_ERR
1067                            "ICMPv6 RA: can't find inet6 device for %s.\n",
1068                            skb->dev->name);
1069                 return;
1070         }
1071         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) {
1072                 in6_dev_put(in6_dev);
1073                 return;
1074         }
1075
1076         if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1077                 in6_dev_put(in6_dev);
1078                 ND_PRINTK2(KERN_WARNING
1079                            "ICMP6 RA: invalid ND options\n");
1080                 return;
1081         }
1082
1083         if (in6_dev->if_flags & IF_RS_SENT) {
1084                 /*
1085                  *      flag that an RA was received after an RS was sent
1086                  *      out on this interface.
1087                  */
1088                 in6_dev->if_flags |= IF_RA_RCVD;
1089         }
1090
1091         /*
1092          * Remember the managed/otherconf flags from most recently
1093          * received RA message (RFC 2462) -- yoshfuji
1094          */
1095         in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1096                                 IF_RA_OTHERCONF)) |
1097                                 (ra_msg->icmph.icmp6_addrconf_managed ?
1098                                         IF_RA_MANAGED : 0) |
1099                                 (ra_msg->icmph.icmp6_addrconf_other ?
1100                                         IF_RA_OTHERCONF : 0);
1101
1102         if (!in6_dev->cnf.accept_ra_defrtr)
1103                 goto skip_defrtr;
1104
1105         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1106
1107 #ifdef CONFIG_IPV6_ROUTER_PREF
1108         pref = ra_msg->icmph.icmp6_router_pref;
1109         /* 10b is handled as if it were 00b (medium) */
1110         if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1111             in6_dev->cnf.accept_ra_rtr_pref)
1112                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1113 #endif
1114
1115         rt = rt6_get_dflt_router(&skb->nh.ipv6h->saddr, skb->dev);
1116
1117         if (rt)
1118                 neigh = rt->rt6i_nexthop;
1119
1120         if (rt && lifetime == 0) {
1121                 neigh_clone(neigh);
1122                 ip6_del_rt(rt);
1123                 rt = NULL;
1124         }
1125
1126         if (rt == NULL && lifetime) {
1127                 ND_PRINTK3(KERN_DEBUG
1128                            "ICMPv6 RA: adding default router.\n");
1129
1130                 rt = rt6_add_dflt_router(&skb->nh.ipv6h->saddr, skb->dev, pref);
1131                 if (rt == NULL) {
1132                         ND_PRINTK0(KERN_ERR
1133                                    "ICMPv6 RA: %s() failed to add default route.\n",
1134                                    __FUNCTION__);
1135                         in6_dev_put(in6_dev);
1136                         return;
1137                 }
1138
1139                 neigh = rt->rt6i_nexthop;
1140                 if (neigh == NULL) {
1141                         ND_PRINTK0(KERN_ERR
1142                                    "ICMPv6 RA: %s() got default router without neighbour.\n",
1143                                    __FUNCTION__);
1144                         dst_release(&rt->u.dst);
1145                         in6_dev_put(in6_dev);
1146                         return;
1147                 }
1148                 neigh->flags |= NTF_ROUTER;
1149         } else if (rt) {
1150                 rt->rt6i_flags |= (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1151         }
1152
1153         if (rt)
1154                 rt->rt6i_expires = jiffies + (HZ * lifetime);
1155
1156         if (ra_msg->icmph.icmp6_hop_limit) {
1157                 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1158                 if (rt)
1159                         rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit;
1160         }
1161
1162 skip_defrtr:
1163
1164         /*
1165          *      Update Reachable Time and Retrans Timer
1166          */
1167
1168         if (in6_dev->nd_parms) {
1169                 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1170
1171                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1172                         rtime = (rtime*HZ)/1000;
1173                         if (rtime < HZ/10)
1174                                 rtime = HZ/10;
1175                         in6_dev->nd_parms->retrans_time = rtime;
1176                         in6_dev->tstamp = jiffies;
1177                         inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1178                 }
1179
1180                 rtime = ntohl(ra_msg->reachable_time);
1181                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1182                         rtime = (rtime*HZ)/1000;
1183
1184                         if (rtime < HZ/10)
1185                                 rtime = HZ/10;
1186
1187                         if (rtime != in6_dev->nd_parms->base_reachable_time) {
1188                                 in6_dev->nd_parms->base_reachable_time = rtime;
1189                                 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1190                                 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1191                                 in6_dev->tstamp = jiffies;
1192                                 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1193                         }
1194                 }
1195         }
1196
1197         /*
1198          *      Process options.
1199          */
1200
1201         if (!neigh)
1202                 neigh = __neigh_lookup(&nd_tbl, &skb->nh.ipv6h->saddr,
1203                                        skb->dev, 1);
1204         if (neigh) {
1205                 u8 *lladdr = NULL;
1206                 if (ndopts.nd_opts_src_lladdr) {
1207                         lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1208                                                      skb->dev);
1209                         if (!lladdr) {
1210                                 ND_PRINTK2(KERN_WARNING
1211                                            "ICMPv6 RA: invalid link-layer address length\n");
1212                                 goto out;
1213                         }
1214                 }
1215                 neigh_update(neigh, lladdr, NUD_STALE,
1216                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1217                              NEIGH_UPDATE_F_OVERRIDE|
1218                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1219                              NEIGH_UPDATE_F_ISROUTER);
1220         }
1221
1222 #ifdef CONFIG_IPV6_ROUTE_INFO
1223         if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1224                 struct nd_opt_hdr *p;
1225                 for (p = ndopts.nd_opts_ri;
1226                      p;
1227                      p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1228                         if (((struct route_info *)p)->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1229                                 continue;
1230                         rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1231                                       &skb->nh.ipv6h->saddr);
1232                 }
1233         }
1234 #endif
1235
1236         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1237                 struct nd_opt_hdr *p;
1238                 for (p = ndopts.nd_opts_pi;
1239                      p;
1240                      p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1241                         addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
1242                 }
1243         }
1244
1245         if (ndopts.nd_opts_mtu) {
1246                 u32 mtu;
1247
1248                 memcpy(&mtu, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1249                 mtu = ntohl(mtu);
1250
1251                 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1252                         ND_PRINTK2(KERN_WARNING
1253                                    "ICMPv6 RA: invalid mtu: %d\n",
1254                                    mtu);
1255                 } else if (in6_dev->cnf.mtu6 != mtu) {
1256                         in6_dev->cnf.mtu6 = mtu;
1257
1258                         if (rt)
1259                                 rt->u.dst.metrics[RTAX_MTU-1] = mtu;
1260
1261                         rt6_mtu_change(skb->dev, mtu);
1262                 }
1263         }
1264                         
1265         if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1266                 ND_PRINTK2(KERN_WARNING
1267                            "ICMPv6 RA: invalid RA options");
1268         }
1269 out:
1270         if (rt)
1271                 dst_release(&rt->u.dst);
1272         else if (neigh)
1273                 neigh_release(neigh);
1274         in6_dev_put(in6_dev);
1275 }
1276
1277 static void ndisc_redirect_rcv(struct sk_buff *skb)
1278 {
1279         struct inet6_dev *in6_dev;
1280         struct icmp6hdr *icmph;
1281         struct in6_addr *dest;
1282         struct in6_addr *target;        /* new first hop to destination */
1283         struct neighbour *neigh;
1284         int on_link = 0;
1285         struct ndisc_options ndopts;
1286         int optlen;
1287         u8 *lladdr = NULL;
1288
1289         if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
1290                 ND_PRINTK2(KERN_WARNING
1291                            "ICMPv6 Redirect: source address is not link-local.\n");
1292                 return;
1293         }
1294
1295         optlen = skb->tail - skb->h.raw;
1296         optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1297
1298         if (optlen < 0) {
1299                 ND_PRINTK2(KERN_WARNING
1300                            "ICMPv6 Redirect: packet too short\n");
1301                 return;
1302         }
1303
1304         icmph = (struct icmp6hdr *) skb->h.raw;
1305         target = (struct in6_addr *) (icmph + 1);
1306         dest = target + 1;
1307
1308         if (ipv6_addr_is_multicast(dest)) {
1309                 ND_PRINTK2(KERN_WARNING
1310                            "ICMPv6 Redirect: destination address is multicast.\n");
1311                 return;
1312         }
1313
1314         if (ipv6_addr_equal(dest, target)) {
1315                 on_link = 1;
1316         } else if (!(ipv6_addr_type(target) & IPV6_ADDR_LINKLOCAL)) {
1317                 ND_PRINTK2(KERN_WARNING 
1318                            "ICMPv6 Redirect: target address is not link-local.\n");
1319                 return;
1320         }
1321
1322         in6_dev = in6_dev_get(skb->dev);
1323         if (!in6_dev)
1324                 return;
1325         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1326                 in6_dev_put(in6_dev);
1327                 return;
1328         }
1329
1330         /* RFC2461 8.1: 
1331          *      The IP source address of the Redirect MUST be the same as the current
1332          *      first-hop router for the specified ICMP Destination Address.
1333          */
1334                 
1335         if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1336                 ND_PRINTK2(KERN_WARNING
1337                            "ICMPv6 Redirect: invalid ND options\n");
1338                 in6_dev_put(in6_dev);
1339                 return;
1340         }
1341         if (ndopts.nd_opts_tgt_lladdr) {
1342                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1343                                              skb->dev);
1344                 if (!lladdr) {
1345                         ND_PRINTK2(KERN_WARNING
1346                                    "ICMPv6 Redirect: invalid link-layer address length\n");
1347                         in6_dev_put(in6_dev);
1348                         return;
1349                 }
1350         }
1351
1352         neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1353         if (neigh) {
1354                 rt6_redirect(dest, &skb->nh.ipv6h->daddr,
1355                              &skb->nh.ipv6h->saddr, neigh, lladdr,
1356                              on_link);
1357                 neigh_release(neigh);
1358         }
1359         in6_dev_put(in6_dev);
1360 }
1361
1362 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1363                          struct in6_addr *target)
1364 {
1365         struct sock *sk = ndisc_socket->sk;
1366         int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1367         struct sk_buff *buff;
1368         struct icmp6hdr *icmph;
1369         struct in6_addr saddr_buf;
1370         struct in6_addr *addrp;
1371         struct net_device *dev;
1372         struct rt6_info *rt;
1373         struct dst_entry *dst;
1374         struct inet6_dev *idev;
1375         struct flowi fl;
1376         u8 *opt;
1377         int rd_len;
1378         int err;
1379         int hlen;
1380         u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1381
1382         dev = skb->dev;
1383
1384         if (ipv6_get_lladdr(dev, &saddr_buf)) {
1385                 ND_PRINTK2(KERN_WARNING
1386                            "ICMPv6 Redirect: no link-local address on %s\n",
1387                            dev->name);
1388                 return;
1389         }
1390
1391         ndisc_flow_init(&fl, NDISC_REDIRECT, &saddr_buf, &skb->nh.ipv6h->saddr,
1392                         dev->ifindex);
1393
1394         dst = ip6_route_output(NULL, &fl);
1395         if (dst == NULL)
1396                 return;
1397
1398         err = xfrm_lookup(&dst, &fl, NULL, 0);
1399         if (err)
1400                 return;
1401
1402         rt = (struct rt6_info *) dst;
1403
1404         if (rt->rt6i_flags & RTF_GATEWAY) {
1405                 ND_PRINTK2(KERN_WARNING
1406                            "ICMPv6 Redirect: destination is not a neighbour.\n");
1407                 dst_release(dst);
1408                 return;
1409         }
1410         if (!xrlim_allow(dst, 1*HZ)) {
1411                 dst_release(dst);
1412                 return;
1413         }
1414
1415         if (dev->addr_len) {
1416                 read_lock_bh(&neigh->lock);
1417                 if (neigh->nud_state & NUD_VALID) {
1418                         memcpy(ha_buf, neigh->ha, dev->addr_len);
1419                         read_unlock_bh(&neigh->lock);
1420                         ha = ha_buf;
1421                         len += ndisc_opt_addr_space(dev);
1422                 } else
1423                         read_unlock_bh(&neigh->lock);
1424         }
1425
1426         rd_len = min_t(unsigned int,
1427                      IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1428         rd_len &= ~0x7;
1429         len += rd_len;
1430
1431         buff = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
1432                                    1, &err);
1433         if (buff == NULL) {
1434                 ND_PRINTK0(KERN_ERR
1435                            "ICMPv6 Redirect: %s() failed to allocate an skb.\n",
1436                            __FUNCTION__);
1437                 dst_release(dst);
1438                 return;
1439         }
1440
1441         hlen = 0;
1442
1443         skb_reserve(buff, LL_RESERVED_SPACE(dev));
1444         ip6_nd_hdr(sk, buff, dev, &saddr_buf, &skb->nh.ipv6h->saddr,
1445                    IPPROTO_ICMPV6, len);
1446
1447         icmph = (struct icmp6hdr *)skb_put(buff, len);
1448         buff->h.raw = (unsigned char*)icmph;
1449
1450         memset(icmph, 0, sizeof(struct icmp6hdr));
1451         icmph->icmp6_type = NDISC_REDIRECT;
1452
1453         /*
1454          *      copy target and destination addresses
1455          */
1456
1457         addrp = (struct in6_addr *)(icmph + 1);
1458         ipv6_addr_copy(addrp, target);
1459         addrp++;
1460         ipv6_addr_copy(addrp, &skb->nh.ipv6h->daddr);
1461
1462         opt = (u8*) (addrp + 1);
1463
1464         /*
1465          *      include target_address option
1466          */
1467
1468         if (ha)
1469                 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1470                                              dev->addr_len, dev->type);
1471
1472         /*
1473          *      build redirect option and copy skb over to the new packet.
1474          */
1475
1476         memset(opt, 0, 8);      
1477         *(opt++) = ND_OPT_REDIRECT_HDR;
1478         *(opt++) = (rd_len >> 3);
1479         opt += 6;
1480
1481         memcpy(opt, skb->nh.ipv6h, rd_len - 8);
1482
1483         icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &skb->nh.ipv6h->saddr,
1484                                              len, IPPROTO_ICMPV6,
1485                                              csum_partial((u8 *) icmph, len, 0));
1486
1487         buff->dst = dst;
1488         idev = in6_dev_get(dst->dev);
1489         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
1490         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, buff, NULL, dst->dev, dst_output);
1491         if (!err) {
1492                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTREDIRECTS);
1493                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
1494         }
1495
1496         if (likely(idev != NULL))
1497                 in6_dev_put(idev);
1498 }
1499
1500 static void pndisc_redo(struct sk_buff *skb)
1501 {
1502         ndisc_recv_ns(skb);
1503         kfree_skb(skb);
1504 }
1505
1506 int ndisc_rcv(struct sk_buff *skb)
1507 {
1508         struct nd_msg *msg;
1509
1510         if (!pskb_may_pull(skb, skb->len))
1511                 return 0;
1512
1513         msg = (struct nd_msg *) skb->h.raw;
1514
1515         __skb_push(skb, skb->data-skb->h.raw);
1516
1517         if (skb->nh.ipv6h->hop_limit != 255) {
1518                 ND_PRINTK2(KERN_WARNING
1519                            "ICMPv6 NDISC: invalid hop-limit: %d\n",
1520                            skb->nh.ipv6h->hop_limit);
1521                 return 0;
1522         }
1523
1524         if (msg->icmph.icmp6_code != 0) {
1525                 ND_PRINTK2(KERN_WARNING 
1526                            "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1527                            msg->icmph.icmp6_code);
1528                 return 0;
1529         }
1530
1531         memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1532
1533         switch (msg->icmph.icmp6_type) {
1534         case NDISC_NEIGHBOUR_SOLICITATION:
1535                 ndisc_recv_ns(skb);
1536                 break;
1537
1538         case NDISC_NEIGHBOUR_ADVERTISEMENT:
1539                 ndisc_recv_na(skb);
1540                 break;
1541
1542         case NDISC_ROUTER_SOLICITATION:
1543                 ndisc_recv_rs(skb);
1544                 break;
1545
1546         case NDISC_ROUTER_ADVERTISEMENT:
1547                 ndisc_router_discovery(skb);
1548                 break;
1549
1550         case NDISC_REDIRECT:
1551                 ndisc_redirect_rcv(skb);
1552                 break;
1553         };
1554
1555         return 0;
1556 }
1557
1558 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1559 {
1560         struct net_device *dev = ptr;
1561
1562         switch (event) {
1563         case NETDEV_CHANGEADDR:
1564                 neigh_changeaddr(&nd_tbl, dev);
1565                 fib6_run_gc(~0UL);
1566                 break;
1567         case NETDEV_DOWN:
1568                 neigh_ifdown(&nd_tbl, dev);
1569                 fib6_run_gc(~0UL);
1570                 break;
1571         default:
1572                 break;
1573         }
1574
1575         return NOTIFY_DONE;
1576 }
1577
1578 static struct notifier_block ndisc_netdev_notifier = {
1579         .notifier_call = ndisc_netdev_event,
1580 };
1581
1582 #ifdef CONFIG_SYSCTL
1583 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1584                                          const char *func, const char *dev_name)
1585 {
1586         static char warncomm[TASK_COMM_LEN];
1587         static int warned;
1588         if (strcmp(warncomm, current->comm) && warned < 5) {
1589                 strcpy(warncomm, current->comm);
1590                 printk(KERN_WARNING
1591                         "process `%s' is using deprecated sysctl (%s) "
1592                         "net.ipv6.neigh.%s.%s; "
1593                         "Use net.ipv6.neigh.%s.%s_ms "
1594                         "instead.\n",
1595                         warncomm, func,
1596                         dev_name, ctl->procname,
1597                         dev_name, ctl->procname);
1598                 warned++;
1599         }
1600 }
1601
1602 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, struct file * filp, void __user *buffer, size_t *lenp, loff_t *ppos)
1603 {
1604         struct net_device *dev = ctl->extra1;
1605         struct inet6_dev *idev;
1606         int ret;
1607
1608         if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
1609             ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
1610                 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1611
1612         switch (ctl->ctl_name) {
1613         case NET_NEIGH_RETRANS_TIME:
1614                 ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
1615                 break;
1616         case NET_NEIGH_REACHABLE_TIME:
1617                 ret = proc_dointvec_jiffies(ctl, write,
1618                                             filp, buffer, lenp, ppos);
1619                 break;
1620         case NET_NEIGH_RETRANS_TIME_MS:
1621         case NET_NEIGH_REACHABLE_TIME_MS:
1622                 ret = proc_dointvec_ms_jiffies(ctl, write,
1623                                                filp, buffer, lenp, ppos);
1624                 break;
1625         default:
1626                 ret = -1;
1627         }
1628
1629         if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1630                 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
1631                     ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
1632                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1633                 idev->tstamp = jiffies;
1634                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1635                 in6_dev_put(idev);
1636         }
1637         return ret;
1638 }
1639
1640 static int ndisc_ifinfo_sysctl_strategy(ctl_table *ctl, int __user *name,
1641                                         int nlen, void __user *oldval,
1642                                         size_t __user *oldlenp,
1643                                         void __user *newval, size_t newlen,
1644                                         void **context)
1645 {
1646         struct net_device *dev = ctl->extra1;
1647         struct inet6_dev *idev;
1648         int ret;
1649
1650         if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
1651             ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
1652                 ndisc_warn_deprecated_sysctl(ctl, "procfs", dev ? dev->name : "default");
1653
1654         switch (ctl->ctl_name) {
1655         case NET_NEIGH_REACHABLE_TIME:
1656                 ret = sysctl_jiffies(ctl, name, nlen,
1657                                      oldval, oldlenp, newval, newlen,
1658                                      context);
1659                 break;
1660         case NET_NEIGH_RETRANS_TIME_MS:
1661         case NET_NEIGH_REACHABLE_TIME_MS:
1662                  ret = sysctl_ms_jiffies(ctl, name, nlen,
1663                                          oldval, oldlenp, newval, newlen,
1664                                          context);
1665                  break;
1666         default:
1667                 ret = 0;
1668         }
1669
1670         if (newval && newlen && ret > 0 &&
1671             dev && (idev = in6_dev_get(dev)) != NULL) {
1672                 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
1673                     ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
1674                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1675                 idev->tstamp = jiffies;
1676                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1677                 in6_dev_put(idev);
1678         }
1679
1680         return ret;
1681 }
1682
1683 #endif
1684
1685 int __init ndisc_init(struct net_proto_family *ops)
1686 {
1687         struct ipv6_pinfo *np;
1688         struct sock *sk;
1689         int err;
1690
1691         err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, &ndisc_socket);
1692         if (err < 0) {
1693                 ND_PRINTK0(KERN_ERR
1694                            "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n", 
1695                            err);
1696                 ndisc_socket = NULL; /* For safety. */
1697                 return err;
1698         }
1699
1700         sk = ndisc_socket->sk;
1701         np = inet6_sk(sk);
1702         sk->sk_allocation = GFP_ATOMIC;
1703         np->hop_limit = 255;
1704         /* Do not loopback ndisc messages */
1705         np->mc_loop = 0;
1706         sk->sk_prot->unhash(sk);
1707
1708         /*
1709          * Initialize the neighbour table
1710          */
1711         
1712         neigh_table_init(&nd_tbl);
1713
1714 #ifdef CONFIG_SYSCTL
1715         neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6, NET_IPV6_NEIGH, 
1716                               "ipv6",
1717                               &ndisc_ifinfo_sysctl_change,
1718                               &ndisc_ifinfo_sysctl_strategy);
1719 #endif
1720
1721         register_netdevice_notifier(&ndisc_netdev_notifier);
1722         return 0;
1723 }
1724
1725 void ndisc_cleanup(void)
1726 {
1727 #ifdef CONFIG_SYSCTL
1728         neigh_sysctl_unregister(&nd_tbl.parms);
1729 #endif
1730         neigh_table_clear(&nd_tbl);
1731         sock_release(ndisc_socket);
1732         ndisc_socket = NULL; /* For safety. */
1733 }