1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Neighbour Discovery for IPv6
4 * Linux INET6 implementation
7 * Pedro Roque <roque@di.fc.ul.pt>
8 * Mike Shaver <shaver@ingenia.com>
14 * Alexey I. Froloff : RFC6106 (DNSSL) support
15 * Pierre Ynard : export userland ND options
16 * through netlink (RDNSS support)
17 * Lars Fenneberg : fixed MTU setting on receipt
19 * Janos Farkas : kmalloc failure checks
20 * Alexey Kuznetsov : state machine reworked
21 * and moved to net/core.
22 * Pekka Savola : RFC2461 validation
23 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
26 #define pr_fmt(fmt) "ICMPv6: " fmt
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/types.h>
31 #include <linux/socket.h>
32 #include <linux/sockios.h>
33 #include <linux/sched.h>
34 #include <linux/net.h>
35 #include <linux/in6.h>
36 #include <linux/route.h>
37 #include <linux/init.h>
38 #include <linux/rcupdate.h>
39 #include <linux/slab.h>
41 #include <linux/sysctl.h>
44 #include <linux/if_addr.h>
45 #include <linux/if_ether.h>
46 #include <linux/if_arp.h>
47 #include <linux/ipv6.h>
48 #include <linux/icmpv6.h>
49 #include <linux/jhash.h>
55 #include <net/protocol.h>
56 #include <net/ndisc.h>
57 #include <net/ip6_route.h>
58 #include <net/addrconf.h>
61 #include <net/netlink.h>
62 #include <linux/rtnetlink.h>
65 #include <net/ip6_checksum.h>
66 #include <net/inet_common.h>
67 #include <linux/proc_fs.h>
69 #include <linux/netfilter.h>
70 #include <linux/netfilter_ipv6.h>
72 static u32 ndisc_hash(const void *pkey,
73 const struct net_device *dev,
75 static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
76 static bool ndisc_allow_add(const struct net_device *dev,
77 struct netlink_ext_ack *extack);
78 static int ndisc_constructor(struct neighbour *neigh);
79 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
80 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
81 static int pndisc_constructor(struct pneigh_entry *n);
82 static void pndisc_destructor(struct pneigh_entry *n);
83 static void pndisc_redo(struct sk_buff *skb);
84 static int ndisc_is_multicast(const void *pkey);
86 static const struct neigh_ops ndisc_generic_ops = {
88 .solicit = ndisc_solicit,
89 .error_report = ndisc_error_report,
90 .output = neigh_resolve_output,
91 .connected_output = neigh_connected_output,
94 static const struct neigh_ops ndisc_hh_ops = {
96 .solicit = ndisc_solicit,
97 .error_report = ndisc_error_report,
98 .output = neigh_resolve_output,
99 .connected_output = neigh_resolve_output,
103 static const struct neigh_ops ndisc_direct_ops = {
105 .output = neigh_direct_output,
106 .connected_output = neigh_direct_output,
109 struct neigh_table nd_tbl = {
111 .key_len = sizeof(struct in6_addr),
112 .protocol = cpu_to_be16(ETH_P_IPV6),
114 .key_eq = ndisc_key_eq,
115 .constructor = ndisc_constructor,
116 .pconstructor = pndisc_constructor,
117 .pdestructor = pndisc_destructor,
118 .proxy_redo = pndisc_redo,
119 .is_multicast = ndisc_is_multicast,
120 .allow_add = ndisc_allow_add,
124 .reachable_time = ND_REACHABLE_TIME,
126 [NEIGH_VAR_MCAST_PROBES] = 3,
127 [NEIGH_VAR_UCAST_PROBES] = 3,
128 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
129 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
130 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
131 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
132 [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
133 [NEIGH_VAR_PROXY_QLEN] = 64,
134 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
135 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
138 .gc_interval = 30 * HZ,
143 EXPORT_SYMBOL_GPL(nd_tbl);
145 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
146 int data_len, int pad)
148 int space = __ndisc_opt_addr_space(data_len, pad);
149 u8 *opt = skb_put(skb, space);
154 memset(opt + 2, 0, pad);
158 memcpy(opt+2, data, data_len);
163 memset(opt, 0, space);
165 EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
167 static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
168 void *data, u8 icmp6_type)
170 __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
171 ndisc_addr_option_pad(skb->dev->type));
172 ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
175 static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
179 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
180 ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
183 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
184 struct nd_opt_hdr *end)
187 if (!cur || !end || cur >= end)
189 type = cur->nd_opt_type;
191 cur = ((void *)cur) + (cur->nd_opt_len << 3);
192 } while (cur < end && cur->nd_opt_type != type);
193 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
196 static inline int ndisc_is_useropt(const struct net_device *dev,
197 struct nd_opt_hdr *opt)
199 return opt->nd_opt_type == ND_OPT_PREFIX_INFO ||
200 opt->nd_opt_type == ND_OPT_RDNSS ||
201 opt->nd_opt_type == ND_OPT_DNSSL ||
202 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
203 opt->nd_opt_type == ND_OPT_PREF64 ||
204 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
207 static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
208 struct nd_opt_hdr *cur,
209 struct nd_opt_hdr *end)
211 if (!cur || !end || cur >= end)
214 cur = ((void *)cur) + (cur->nd_opt_len << 3);
215 } while (cur < end && !ndisc_is_useropt(dev, cur));
216 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
219 struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
220 u8 *opt, int opt_len,
221 struct ndisc_options *ndopts)
223 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
225 if (!nd_opt || opt_len < 0 || !ndopts)
227 memset(ndopts, 0, sizeof(*ndopts));
230 if (opt_len < sizeof(struct nd_opt_hdr))
232 l = nd_opt->nd_opt_len << 3;
233 if (opt_len < l || l == 0)
235 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
237 switch (nd_opt->nd_opt_type) {
238 case ND_OPT_SOURCE_LL_ADDR:
239 case ND_OPT_TARGET_LL_ADDR:
242 case ND_OPT_REDIRECT_HDR:
243 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
245 "%s: duplicated ND6 option found: type=%d\n",
246 __func__, nd_opt->nd_opt_type);
248 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
251 case ND_OPT_PREFIX_INFO:
252 ndopts->nd_opts_pi_end = nd_opt;
253 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
254 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
256 #ifdef CONFIG_IPV6_ROUTE_INFO
257 case ND_OPT_ROUTE_INFO:
258 ndopts->nd_opts_ri_end = nd_opt;
259 if (!ndopts->nd_opts_ri)
260 ndopts->nd_opts_ri = nd_opt;
264 if (ndisc_is_useropt(dev, nd_opt)) {
265 ndopts->nd_useropts_end = nd_opt;
266 if (!ndopts->nd_useropts)
267 ndopts->nd_useropts = nd_opt;
270 * Unknown options must be silently ignored,
271 * to accommodate future extension to the
275 "%s: ignored unsupported option; type=%d, len=%d\n",
283 nd_opt = ((void *)nd_opt) + l;
288 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
292 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
294 ipv6_eth_mc_map(addr, buf);
297 ipv6_arcnet_mc_map(addr, buf);
299 case ARPHRD_INFINIBAND:
300 ipv6_ib_mc_map(addr, dev->broadcast, buf);
303 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
306 memcpy(buf, dev->broadcast, dev->addr_len);
312 EXPORT_SYMBOL(ndisc_mc_map);
314 static u32 ndisc_hash(const void *pkey,
315 const struct net_device *dev,
318 return ndisc_hashfn(pkey, dev, hash_rnd);
321 static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
323 return neigh_key_eq128(n, pkey);
326 static int ndisc_constructor(struct neighbour *neigh)
328 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
329 struct net_device *dev = neigh->dev;
330 struct inet6_dev *in6_dev;
331 struct neigh_parms *parms;
332 bool is_multicast = ipv6_addr_is_multicast(addr);
334 in6_dev = in6_dev_get(dev);
339 parms = in6_dev->nd_parms;
340 __neigh_parms_put(neigh->parms);
341 neigh->parms = neigh_parms_clone(parms);
343 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
344 if (!dev->header_ops) {
345 neigh->nud_state = NUD_NOARP;
346 neigh->ops = &ndisc_direct_ops;
347 neigh->output = neigh_direct_output;
350 neigh->nud_state = NUD_NOARP;
351 ndisc_mc_map(addr, neigh->ha, dev, 1);
352 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
353 neigh->nud_state = NUD_NOARP;
354 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
355 if (dev->flags&IFF_LOOPBACK)
356 neigh->type = RTN_LOCAL;
357 } else if (dev->flags&IFF_POINTOPOINT) {
358 neigh->nud_state = NUD_NOARP;
359 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
361 if (dev->header_ops->cache)
362 neigh->ops = &ndisc_hh_ops;
364 neigh->ops = &ndisc_generic_ops;
365 if (neigh->nud_state&NUD_VALID)
366 neigh->output = neigh->ops->connected_output;
368 neigh->output = neigh->ops->output;
370 in6_dev_put(in6_dev);
374 static int pndisc_constructor(struct pneigh_entry *n)
376 struct in6_addr *addr = (struct in6_addr *)&n->key;
377 struct in6_addr maddr;
378 struct net_device *dev = n->dev;
380 if (!dev || !__in6_dev_get(dev))
382 addrconf_addr_solict_mult(addr, &maddr);
383 ipv6_dev_mc_inc(dev, &maddr);
387 static void pndisc_destructor(struct pneigh_entry *n)
389 struct in6_addr *addr = (struct in6_addr *)&n->key;
390 struct in6_addr maddr;
391 struct net_device *dev = n->dev;
393 if (!dev || !__in6_dev_get(dev))
395 addrconf_addr_solict_mult(addr, &maddr);
396 ipv6_dev_mc_dec(dev, &maddr);
399 /* called with rtnl held */
400 static bool ndisc_allow_add(const struct net_device *dev,
401 struct netlink_ext_ack *extack)
403 struct inet6_dev *idev = __in6_dev_get(dev);
405 if (!idev || idev->cnf.disable_ipv6) {
406 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
413 static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
416 int hlen = LL_RESERVED_SPACE(dev);
417 int tlen = dev->needed_tailroom;
418 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
421 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
423 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
428 skb->protocol = htons(ETH_P_IPV6);
431 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
432 skb_reset_transport_header(skb);
434 /* Manually assign socket ownership as we avoid calling
435 * sock_alloc_send_pskb() to bypass wmem buffer limits
437 skb_set_owner_w(skb, sk);
442 static void ip6_nd_hdr(struct sk_buff *skb,
443 const struct in6_addr *saddr,
444 const struct in6_addr *daddr,
445 int hop_limit, int len)
448 struct inet6_dev *idev;
452 idev = __in6_dev_get(skb->dev);
453 tclass = idev ? idev->cnf.ndisc_tclass : 0;
456 skb_push(skb, sizeof(*hdr));
457 skb_reset_network_header(skb);
460 ip6_flow_hdr(hdr, tclass, 0);
462 hdr->payload_len = htons(len);
463 hdr->nexthdr = IPPROTO_ICMPV6;
464 hdr->hop_limit = hop_limit;
470 static void ndisc_send_skb(struct sk_buff *skb,
471 const struct in6_addr *daddr,
472 const struct in6_addr *saddr)
474 struct dst_entry *dst = skb_dst(skb);
475 struct net *net = dev_net(skb->dev);
476 struct sock *sk = net->ipv6.ndisc_sk;
477 struct inet6_dev *idev;
479 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
482 type = icmp6h->icmp6_type;
486 int oif = skb->dev->ifindex;
488 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
489 dst = icmp6_dst_alloc(skb->dev, &fl6);
495 skb_dst_set(skb, dst);
498 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
503 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
506 idev = __in6_dev_get(dst->dev);
507 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
509 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
510 net, sk, skb, NULL, dst->dev,
513 ICMP6MSGOUT_INC_STATS(net, idev, type);
514 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
520 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
521 const struct in6_addr *solicited_addr,
522 bool router, bool solicited, bool override, bool inc_opt)
525 struct in6_addr tmpaddr;
526 struct inet6_ifaddr *ifp;
527 const struct in6_addr *src_addr;
531 /* for anycast or proxy, solicited_addr != src_addr */
532 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
534 src_addr = solicited_addr;
535 if (ifp->flags & IFA_F_OPTIMISTIC)
537 inc_opt |= ifp->idev->cnf.force_tllao;
540 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
541 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
550 optlen += ndisc_opt_addr_space(dev,
551 NDISC_NEIGHBOUR_ADVERTISEMENT);
553 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
557 msg = skb_put(skb, sizeof(*msg));
558 *msg = (struct nd_msg) {
560 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
561 .icmp6_router = router,
562 .icmp6_solicited = solicited,
563 .icmp6_override = override,
565 .target = *solicited_addr,
569 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
571 NDISC_NEIGHBOUR_ADVERTISEMENT);
573 ndisc_send_skb(skb, daddr, src_addr);
576 static void ndisc_send_unsol_na(struct net_device *dev)
578 struct inet6_dev *idev;
579 struct inet6_ifaddr *ifa;
581 idev = in6_dev_get(dev);
585 read_lock_bh(&idev->lock);
586 list_for_each_entry(ifa, &idev->addr_list, if_list) {
587 /* skip tentative addresses until dad completes */
588 if (ifa->flags & IFA_F_TENTATIVE &&
589 !(ifa->flags & IFA_F_OPTIMISTIC))
592 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
593 /*router=*/ !!idev->cnf.forwarding,
594 /*solicited=*/ false, /*override=*/ true,
597 read_unlock_bh(&idev->lock);
602 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
603 const struct in6_addr *daddr, const struct in6_addr *saddr,
607 struct in6_addr addr_buf;
608 int inc_opt = dev->addr_len;
613 if (ipv6_get_lladdr(dev, &addr_buf,
614 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
619 if (ipv6_addr_any(saddr))
622 optlen += ndisc_opt_addr_space(dev,
623 NDISC_NEIGHBOUR_SOLICITATION);
627 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
631 msg = skb_put(skb, sizeof(*msg));
632 *msg = (struct nd_msg) {
634 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
640 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
642 NDISC_NEIGHBOUR_SOLICITATION);
644 u8 *opt = skb_put(skb, 8);
646 opt[0] = ND_OPT_NONCE;
648 memcpy(opt + 2, &nonce, 6);
651 ndisc_send_skb(skb, daddr, saddr);
654 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
655 const struct in6_addr *daddr)
659 int send_sllao = dev->addr_len;
662 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
664 * According to section 2.2 of RFC 4429, we must not
665 * send router solicitations with a sllao from
666 * optimistic addresses, but we may send the solicitation
667 * if we don't include the sllao. So here we check
668 * if our address is optimistic, and if so, we
669 * suppress the inclusion of the sllao.
672 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
675 if (ifp->flags & IFA_F_OPTIMISTIC) {
685 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
687 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
691 msg = skb_put(skb, sizeof(*msg));
692 *msg = (struct rs_msg) {
694 .icmp6_type = NDISC_ROUTER_SOLICITATION,
699 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
701 NDISC_ROUTER_SOLICITATION);
703 ndisc_send_skb(skb, daddr, saddr);
707 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
710 * "The sender MUST return an ICMP
711 * destination unreachable"
713 dst_link_failure(skb);
717 /* Called with locked neigh: either read or both */
719 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
721 struct in6_addr *saddr = NULL;
722 struct in6_addr mcaddr;
723 struct net_device *dev = neigh->dev;
724 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
725 int probes = atomic_read(&neigh->probes);
727 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
729 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
730 saddr = &ipv6_hdr(skb)->saddr;
731 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
733 if (!(neigh->nud_state & NUD_VALID)) {
735 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
738 ndisc_send_ns(dev, target, target, saddr, 0);
739 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
742 addrconf_addr_solict_mult(target, &mcaddr);
743 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
747 static int pndisc_is_router(const void *pkey,
748 struct net_device *dev)
750 struct pneigh_entry *n;
753 read_lock_bh(&nd_tbl.lock);
754 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
756 ret = !!(n->flags & NTF_ROUTER);
757 read_unlock_bh(&nd_tbl.lock);
762 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
763 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
764 struct ndisc_options *ndopts)
766 neigh_update(neigh, lladdr, new, flags, 0);
767 /* report ndisc ops about neighbour update */
768 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
771 static void ndisc_recv_ns(struct sk_buff *skb)
773 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
774 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
775 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
777 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
778 offsetof(struct nd_msg, opt));
779 struct ndisc_options ndopts;
780 struct net_device *dev = skb->dev;
781 struct inet6_ifaddr *ifp;
782 struct inet6_dev *idev = NULL;
783 struct neighbour *neigh;
784 int dad = ipv6_addr_any(saddr);
789 if (skb->len < sizeof(struct nd_msg)) {
790 ND_PRINTK(2, warn, "NS: packet too short\n");
794 if (ipv6_addr_is_multicast(&msg->target)) {
795 ND_PRINTK(2, warn, "NS: multicast target address\n");
801 * DAD has to be destined for solicited node multicast address.
803 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
804 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
808 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
809 ND_PRINTK(2, warn, "NS: invalid ND options\n");
813 if (ndopts.nd_opts_src_lladdr) {
814 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
817 "NS: invalid link-layer address length\n");
822 * If the IP source address is the unspecified address,
823 * there MUST NOT be source link-layer address option
828 "NS: bad DAD packet (link-layer address option)\n");
832 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
833 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
835 inc = ipv6_addr_is_multicast(daddr);
837 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
840 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
842 if (nonce != 0 && ifp->dad_nonce == nonce) {
843 u8 *np = (u8 *)&nonce;
844 /* Matching nonce if looped back */
846 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
847 ifp->idev->dev->name,
852 * We are colliding with another node
854 * so fail our DAD process
856 addrconf_dad_failure(skb, ifp);
860 * This is not a dad solicitation.
861 * If we are an optimistic node,
863 * Otherwise, we should ignore it.
865 if (!(ifp->flags & IFA_F_OPTIMISTIC))
872 struct net *net = dev_net(dev);
874 /* perhaps an address on the master device */
875 if (netif_is_l3_slave(dev)) {
876 struct net_device *mdev;
878 mdev = netdev_master_upper_dev_get_rcu(dev);
880 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
886 idev = in6_dev_get(dev);
888 /* XXX: count this drop? */
892 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
893 (idev->cnf.forwarding &&
894 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
895 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
896 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
897 skb->pkt_type != PACKET_HOST &&
899 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
901 * for anycast or proxy,
902 * sender should delay its response
903 * by a random time between 0 and
904 * MAX_ANYCAST_DELAY_TIME seconds.
905 * (RFC2461) -- yoshfuji
907 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
909 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
917 is_router = idev->cnf.forwarding;
920 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
921 !!is_router, false, (ifp != NULL), true);
926 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
928 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
931 * update / create cache entry
932 * for the source address
934 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
935 !inc || lladdr || !dev->addr_len);
937 ndisc_update(dev, neigh, lladdr, NUD_STALE,
938 NEIGH_UPDATE_F_WEAK_OVERRIDE|
939 NEIGH_UPDATE_F_OVERRIDE,
940 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
941 if (neigh || !dev->header_ops) {
942 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
943 true, (ifp != NULL && inc), inc);
945 neigh_release(neigh);
955 static void ndisc_recv_na(struct sk_buff *skb)
957 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
958 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
959 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
961 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
962 offsetof(struct nd_msg, opt));
963 struct ndisc_options ndopts;
964 struct net_device *dev = skb->dev;
965 struct inet6_dev *idev = __in6_dev_get(dev);
966 struct inet6_ifaddr *ifp;
967 struct neighbour *neigh;
969 if (skb->len < sizeof(struct nd_msg)) {
970 ND_PRINTK(2, warn, "NA: packet too short\n");
974 if (ipv6_addr_is_multicast(&msg->target)) {
975 ND_PRINTK(2, warn, "NA: target address is multicast\n");
979 if (ipv6_addr_is_multicast(daddr) &&
980 msg->icmph.icmp6_solicited) {
981 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
985 /* For some 802.11 wireless deployments (and possibly other networks),
986 * there will be a NA proxy and unsolicitd packets are attacks
987 * and thus should not be accepted.
989 if (!msg->icmph.icmp6_solicited && idev &&
990 idev->cnf.drop_unsolicited_na)
993 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
994 ND_PRINTK(2, warn, "NS: invalid ND option\n");
997 if (ndopts.nd_opts_tgt_lladdr) {
998 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
1001 "NA: invalid link-layer address length\n");
1005 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1007 if (skb->pkt_type != PACKET_LOOPBACK
1008 && (ifp->flags & IFA_F_TENTATIVE)) {
1009 addrconf_dad_failure(skb, ifp);
1012 /* What should we make now? The advertisement
1013 is invalid, but ndisc specs say nothing
1014 about it. It could be misconfiguration, or
1015 an smart proxy agent tries to help us :-)
1017 We should not print the error if NA has been
1018 received from loopback - it is just our own
1019 unsolicited advertisement.
1021 if (skb->pkt_type != PACKET_LOOPBACK)
1023 "NA: %pM advertised our address %pI6c on %s!\n",
1024 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1028 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1031 u8 old_flags = neigh->flags;
1032 struct net *net = dev_net(dev);
1034 if (neigh->nud_state & NUD_FAILED)
1038 * Don't update the neighbor cache entry on a proxy NA from
1039 * ourselves because either the proxied node is off link or it
1040 * has already sent a NA to us.
1042 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1043 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1044 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1045 /* XXX: idev->cnf.proxy_ndp */
1049 ndisc_update(dev, neigh, lladdr,
1050 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1051 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1052 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1053 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1054 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1055 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1057 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1059 * Change: router to host
1061 rt6_clean_tohost(dev_net(dev), saddr);
1065 neigh_release(neigh);
1069 static void ndisc_recv_rs(struct sk_buff *skb)
1071 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1072 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1073 struct neighbour *neigh;
1074 struct inet6_dev *idev;
1075 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1076 struct ndisc_options ndopts;
1079 if (skb->len < sizeof(*rs_msg))
1082 idev = __in6_dev_get(skb->dev);
1084 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1088 /* Don't accept RS if we're not in router mode */
1089 if (!idev->cnf.forwarding)
1093 * Don't update NCE if src = ::;
1094 * this implies that the source node has no ip address assigned yet.
1096 if (ipv6_addr_any(saddr))
1099 /* Parse ND options */
1100 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1101 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1105 if (ndopts.nd_opts_src_lladdr) {
1106 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1112 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1114 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1115 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1116 NEIGH_UPDATE_F_OVERRIDE|
1117 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1118 NDISC_ROUTER_SOLICITATION, &ndopts);
1119 neigh_release(neigh);
1125 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1127 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1128 struct sk_buff *skb;
1129 struct nlmsghdr *nlh;
1130 struct nduseroptmsg *ndmsg;
1131 struct net *net = dev_net(ra->dev);
1133 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1134 + (opt->nd_opt_len << 3));
1135 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1137 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1143 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1145 goto nla_put_failure;
1148 ndmsg = nlmsg_data(nlh);
1149 ndmsg->nduseropt_family = AF_INET6;
1150 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1151 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1152 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1153 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1155 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1157 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1158 goto nla_put_failure;
1159 nlmsg_end(skb, nlh);
1161 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1168 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1171 static void ndisc_router_discovery(struct sk_buff *skb)
1173 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1174 struct neighbour *neigh = NULL;
1175 struct inet6_dev *in6_dev;
1176 struct fib6_info *rt = NULL;
1179 struct ndisc_options ndopts;
1181 unsigned int pref = 0;
1183 bool send_ifinfo_notify = false;
1185 __u8 *opt = (__u8 *)(ra_msg + 1);
1187 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1188 sizeof(struct ra_msg);
1191 "RA: %s, dev: %s\n",
1192 __func__, skb->dev->name);
1193 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1194 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1198 ND_PRINTK(2, warn, "RA: packet too short\n");
1202 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1203 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1204 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1210 * set the RA_RECV flag in the interface
1213 in6_dev = __in6_dev_get(skb->dev);
1215 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1220 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1221 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1225 if (!ipv6_accept_ra(in6_dev)) {
1227 "RA: %s, did not accept ra for dev: %s\n",
1228 __func__, skb->dev->name);
1229 goto skip_linkparms;
1232 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1233 /* skip link-specific parameters from interior routers */
1234 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1236 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1237 __func__, skb->dev->name);
1238 goto skip_linkparms;
1242 if (in6_dev->if_flags & IF_RS_SENT) {
1244 * flag that an RA was received after an RS was sent
1245 * out on this interface.
1247 in6_dev->if_flags |= IF_RA_RCVD;
1251 * Remember the managed/otherconf flags from most recently
1252 * received RA message (RFC 2462) -- yoshfuji
1254 old_if_flags = in6_dev->if_flags;
1255 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1257 (ra_msg->icmph.icmp6_addrconf_managed ?
1258 IF_RA_MANAGED : 0) |
1259 (ra_msg->icmph.icmp6_addrconf_other ?
1260 IF_RA_OTHERCONF : 0);
1262 if (old_if_flags != in6_dev->if_flags)
1263 send_ifinfo_notify = true;
1265 if (!in6_dev->cnf.accept_ra_defrtr) {
1267 "RA: %s, defrtr is false for dev: %s\n",
1268 __func__, skb->dev->name);
1272 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1273 if (lifetime != 0 && lifetime < in6_dev->cnf.accept_ra_min_lft) {
1275 "RA: router lifetime (%ds) is too short: %s\n",
1276 lifetime, skb->dev->name);
1280 /* Do not accept RA with source-addr found on local machine unless
1281 * accept_ra_from_local is set to true.
1283 net = dev_net(in6_dev->dev);
1284 if (!in6_dev->cnf.accept_ra_from_local &&
1285 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1287 "RA from local address detected on dev: %s: default router ignored\n",
1292 #ifdef CONFIG_IPV6_ROUTER_PREF
1293 pref = ra_msg->icmph.icmp6_router_pref;
1294 /* 10b is handled as if it were 00b (medium) */
1295 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1296 !in6_dev->cnf.accept_ra_rtr_pref)
1297 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1299 /* routes added from RAs do not use nexthop objects */
1300 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1302 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1303 rt->fib6_nh->fib_nh_dev, NULL,
1304 &ipv6_hdr(skb)->saddr);
1307 "RA: %s got default router without neighbour\n",
1309 fib6_info_release(rt);
1313 if (rt && lifetime == 0) {
1314 ip6_del_rt(net, rt, false);
1318 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n",
1319 rt, lifetime, skb->dev->name);
1320 if (!rt && lifetime) {
1321 ND_PRINTK(3, info, "RA: adding default router\n");
1323 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1327 "RA: %s failed to add default route\n",
1332 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1333 rt->fib6_nh->fib_nh_dev, NULL,
1334 &ipv6_hdr(skb)->saddr);
1337 "RA: %s got default router without neighbour\n",
1339 fib6_info_release(rt);
1342 neigh->flags |= NTF_ROUTER;
1344 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1348 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1349 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1350 ra_msg->icmph.icmp6_hop_limit) {
1351 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1352 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1353 fib6_metric_set(rt, RTAX_HOPLIMIT,
1354 ra_msg->icmph.icmp6_hop_limit);
1356 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1363 * Update Reachable Time and Retrans Timer
1366 if (in6_dev->nd_parms) {
1367 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1369 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1370 rtime = (rtime*HZ)/1000;
1373 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1374 in6_dev->tstamp = jiffies;
1375 send_ifinfo_notify = true;
1378 rtime = ntohl(ra_msg->reachable_time);
1379 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1380 rtime = (rtime*HZ)/1000;
1385 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1386 NEIGH_VAR_SET(in6_dev->nd_parms,
1387 BASE_REACHABLE_TIME, rtime);
1388 NEIGH_VAR_SET(in6_dev->nd_parms,
1389 GC_STALETIME, 3 * rtime);
1390 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1391 in6_dev->tstamp = jiffies;
1392 send_ifinfo_notify = true;
1398 * Send a notify if RA changed managed/otherconf flags or timer settings
1400 if (send_ifinfo_notify)
1401 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1410 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1414 if (ndopts.nd_opts_src_lladdr) {
1415 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1419 "RA: invalid link-layer address length\n");
1423 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1424 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1425 NEIGH_UPDATE_F_OVERRIDE|
1426 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1427 NEIGH_UPDATE_F_ISROUTER,
1428 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1431 if (!ipv6_accept_ra(in6_dev)) {
1433 "RA: %s, accept_ra is false for dev: %s\n",
1434 __func__, skb->dev->name);
1438 #ifdef CONFIG_IPV6_ROUTE_INFO
1439 if (!in6_dev->cnf.accept_ra_from_local &&
1440 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1443 "RA from local address detected on dev: %s: router info ignored.\n",
1445 goto skip_routeinfo;
1448 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1449 struct nd_opt_hdr *p;
1450 for (p = ndopts.nd_opts_ri;
1452 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1453 struct route_info *ri = (struct route_info *)p;
1454 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1455 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1456 ri->prefix_len == 0)
1459 if (ri->prefix_len == 0 &&
1460 !in6_dev->cnf.accept_ra_defrtr)
1462 if (ri->lifetime != 0 &&
1463 ntohl(ri->lifetime) < in6_dev->cnf.accept_ra_min_lft)
1465 if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1467 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1469 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1470 &ipv6_hdr(skb)->saddr);
1477 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1478 /* skip link-specific ndopts from interior routers */
1479 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1481 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1482 __func__, skb->dev->name);
1487 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1488 struct nd_opt_hdr *p;
1489 for (p = ndopts.nd_opts_pi;
1491 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1492 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1493 (p->nd_opt_len) << 3,
1494 ndopts.nd_opts_src_lladdr != NULL);
1498 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1502 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1505 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1506 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1507 } else if (in6_dev->cnf.mtu6 != mtu) {
1508 in6_dev->cnf.mtu6 = mtu;
1509 fib6_metric_set(rt, RTAX_MTU, mtu);
1510 rt6_mtu_change(skb->dev, mtu);
1514 if (ndopts.nd_useropts) {
1515 struct nd_opt_hdr *p;
1516 for (p = ndopts.nd_useropts;
1518 p = ndisc_next_useropt(skb->dev, p,
1519 ndopts.nd_useropts_end)) {
1520 ndisc_ra_useropt(skb, p);
1524 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1525 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1528 fib6_info_release(rt);
1530 neigh_release(neigh);
1533 static void ndisc_redirect_rcv(struct sk_buff *skb)
1536 struct ndisc_options ndopts;
1537 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1538 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1539 offsetof(struct rd_msg, opt));
1541 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1542 switch (skb->ndisc_nodetype) {
1543 case NDISC_NODETYPE_HOST:
1544 case NDISC_NODETYPE_NODEFAULT:
1546 "Redirect: from host or unauthorized router\n");
1551 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1553 "Redirect: source address is not link-local\n");
1557 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1560 if (!ndopts.nd_opts_rh) {
1561 ip6_redirect_no_header(skb, dev_net(skb->dev),
1566 hdr = (u8 *)ndopts.nd_opts_rh;
1568 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1571 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1574 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1575 struct sk_buff *orig_skb,
1578 u8 *opt = skb_put(skb, rd_len);
1581 *(opt++) = ND_OPT_REDIRECT_HDR;
1582 *(opt++) = (rd_len >> 3);
1585 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1589 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1591 struct net_device *dev = skb->dev;
1592 struct net *net = dev_net(dev);
1593 struct sock *sk = net->ipv6.ndisc_sk;
1595 struct inet_peer *peer;
1596 struct sk_buff *buff;
1598 struct in6_addr saddr_buf;
1599 struct rt6_info *rt;
1600 struct dst_entry *dst;
1603 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1604 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1607 if (netif_is_l3_master(skb->dev)) {
1608 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1613 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1614 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1619 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1620 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1622 "Redirect: target address is not link-local unicast\n");
1626 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1627 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1629 dst = ip6_route_output(net, NULL, &fl6);
1634 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1638 rt = (struct rt6_info *) dst;
1640 if (rt->rt6i_flags & RTF_GATEWAY) {
1642 "Redirect: destination is not a neighbour\n");
1645 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1646 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1652 if (dev->addr_len) {
1653 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1656 "Redirect: no neigh for target address\n");
1660 read_lock_bh(&neigh->lock);
1661 if (neigh->nud_state & NUD_VALID) {
1662 memcpy(ha_buf, neigh->ha, dev->addr_len);
1663 read_unlock_bh(&neigh->lock);
1665 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1669 read_unlock_bh(&neigh->lock);
1671 neigh_release(neigh);
1674 rd_len = min_t(unsigned int,
1675 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1680 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1684 msg = skb_put(buff, sizeof(*msg));
1685 *msg = (struct rd_msg) {
1687 .icmp6_type = NDISC_REDIRECT,
1690 .dest = ipv6_hdr(skb)->daddr,
1694 * include target_address option
1698 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1701 * build redirect option and copy skb over to the new packet.
1705 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1707 skb_dst_set(buff, dst);
1708 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1715 static void pndisc_redo(struct sk_buff *skb)
1721 static int ndisc_is_multicast(const void *pkey)
1723 return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1726 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1728 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1732 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1733 idev->cnf.suppress_frag_ndisc) {
1734 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1740 int ndisc_rcv(struct sk_buff *skb)
1744 if (ndisc_suppress_frag_ndisc(skb))
1747 if (skb_linearize(skb))
1750 msg = (struct nd_msg *)skb_transport_header(skb);
1752 __skb_push(skb, skb->data - skb_transport_header(skb));
1754 if (ipv6_hdr(skb)->hop_limit != 255) {
1755 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1756 ipv6_hdr(skb)->hop_limit);
1760 if (msg->icmph.icmp6_code != 0) {
1761 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1762 msg->icmph.icmp6_code);
1766 switch (msg->icmph.icmp6_type) {
1767 case NDISC_NEIGHBOUR_SOLICITATION:
1768 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1772 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1776 case NDISC_ROUTER_SOLICITATION:
1780 case NDISC_ROUTER_ADVERTISEMENT:
1781 ndisc_router_discovery(skb);
1784 case NDISC_REDIRECT:
1785 ndisc_redirect_rcv(skb);
1792 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1794 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1795 struct netdev_notifier_change_info *change_info;
1796 struct net *net = dev_net(dev);
1797 struct inet6_dev *idev;
1800 case NETDEV_CHANGEADDR:
1801 neigh_changeaddr(&nd_tbl, dev);
1802 fib6_run_gc(0, net, false);
1805 idev = in6_dev_get(dev);
1808 if (idev->cnf.ndisc_notify ||
1809 net->ipv6.devconf_all->ndisc_notify)
1810 ndisc_send_unsol_na(dev);
1815 if (change_info->flags_changed & IFF_NOARP)
1816 neigh_changeaddr(&nd_tbl, dev);
1817 if (!netif_carrier_ok(dev))
1818 neigh_carrier_down(&nd_tbl, dev);
1821 neigh_ifdown(&nd_tbl, dev);
1822 fib6_run_gc(0, net, false);
1824 case NETDEV_NOTIFY_PEERS:
1825 ndisc_send_unsol_na(dev);
1834 static struct notifier_block ndisc_netdev_notifier = {
1835 .notifier_call = ndisc_netdev_event,
1836 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1839 #ifdef CONFIG_SYSCTL
1840 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1841 const char *func, const char *dev_name)
1843 static char warncomm[TASK_COMM_LEN];
1845 if (strcmp(warncomm, current->comm) && warned < 5) {
1846 strcpy(warncomm, current->comm);
1847 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1849 dev_name, ctl->procname,
1850 dev_name, ctl->procname);
1855 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1856 size_t *lenp, loff_t *ppos)
1858 struct net_device *dev = ctl->extra1;
1859 struct inet6_dev *idev;
1862 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1863 (strcmp(ctl->procname, "base_reachable_time") == 0))
1864 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1866 if (strcmp(ctl->procname, "retrans_time") == 0)
1867 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1869 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1870 ret = neigh_proc_dointvec_jiffies(ctl, write,
1871 buffer, lenp, ppos);
1873 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1874 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1875 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1876 buffer, lenp, ppos);
1880 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1881 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1882 idev->nd_parms->reachable_time =
1883 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1884 idev->tstamp = jiffies;
1885 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1894 static int __net_init ndisc_net_init(struct net *net)
1896 struct ipv6_pinfo *np;
1900 err = inet_ctl_sock_create(&sk, PF_INET6,
1901 SOCK_RAW, IPPROTO_ICMPV6, net);
1904 "NDISC: Failed to initialize the control socket (err %d)\n",
1909 net->ipv6.ndisc_sk = sk;
1912 np->hop_limit = 255;
1913 /* Do not loopback ndisc messages */
1919 static void __net_exit ndisc_net_exit(struct net *net)
1921 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1924 static struct pernet_operations ndisc_net_ops = {
1925 .init = ndisc_net_init,
1926 .exit = ndisc_net_exit,
1929 int __init ndisc_init(void)
1933 err = register_pernet_subsys(&ndisc_net_ops);
1937 * Initialize the neighbour table
1939 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1941 #ifdef CONFIG_SYSCTL
1942 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1943 ndisc_ifinfo_sysctl_change);
1945 goto out_unregister_pernet;
1950 #ifdef CONFIG_SYSCTL
1951 out_unregister_pernet:
1952 unregister_pernet_subsys(&ndisc_net_ops);
1957 int __init ndisc_late_init(void)
1959 return register_netdevice_notifier(&ndisc_netdev_notifier);
1962 void ndisc_late_cleanup(void)
1964 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1967 void ndisc_cleanup(void)
1969 #ifdef CONFIG_SYSCTL
1970 neigh_sysctl_unregister(&nd_tbl.parms);
1972 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1973 unregister_pernet_subsys(&ndisc_net_ops);