2 * Internet Control Message Protocol (ICMPv6)
3 * Linux INET6 implementation
6 * Pedro Roque <roque@di.fc.ul.pt>
8 * Based on net/ipv4/icmp.c
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
21 * Andi Kleen : exception handling
22 * Andi Kleen add rate limits. never reply to a icmp.
23 * add more length checks and other fixes.
24 * yoshfuji : ensure to sent parameter problem for
26 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit.
28 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support
29 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data
32 #define pr_fmt(fmt) "IPv6: " fmt
34 #include <linux/module.h>
35 #include <linux/errno.h>
36 #include <linux/types.h>
37 #include <linux/socket.h>
39 #include <linux/kernel.h>
40 #include <linux/sockios.h>
41 #include <linux/net.h>
42 #include <linux/skbuff.h>
43 #include <linux/init.h>
44 #include <linux/netfilter.h>
45 #include <linux/slab.h>
48 #include <linux/sysctl.h>
51 #include <linux/inet.h>
52 #include <linux/netdevice.h>
53 #include <linux/icmpv6.h>
59 #include <net/ip6_checksum.h>
61 #include <net/protocol.h>
63 #include <net/rawv6.h>
64 #include <net/transp_v6.h>
65 #include <net/ip6_route.h>
66 #include <net/addrconf.h>
69 #include <net/inet_common.h>
70 #include <net/dsfield.h>
71 #include <net/l3mdev.h>
73 #include <linux/uaccess.h>
76 * The ICMP socket(s). This is the most convenient way to flow control
77 * our ICMP output as well as maintain a clean interface throughout
78 * all layers. All Socketless IP sends will soon be gone.
80 * On SMP we have one ICMP socket per-cpu.
82 static inline struct sock *icmpv6_sk(struct net *net)
84 return net->ipv6.icmp_sk[smp_processor_id()];
87 static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
88 u8 type, u8 code, int offset, __be32 info)
90 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
91 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
92 struct net *net = dev_net(skb->dev);
94 if (type == ICMPV6_PKT_TOOBIG)
95 ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL));
96 else if (type == NDISC_REDIRECT)
97 ip6_redirect(skb, net, skb->dev->ifindex, 0,
98 sock_net_uid(net, NULL));
100 if (!(type & ICMPV6_INFOMSG_MASK))
101 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
102 ping_err(skb, offset, ntohl(info));
107 static int icmpv6_rcv(struct sk_buff *skb);
109 static const struct inet6_protocol icmpv6_protocol = {
110 .handler = icmpv6_rcv,
111 .err_handler = icmpv6_err,
112 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
115 /* Called with BH disabled */
116 static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
121 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
122 /* This can happen if the output path (f.e. SIT or
123 * ip6ip6 tunnel) signals dst_link_failure() for an
124 * outgoing ICMP6 packet.
131 static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
133 spin_unlock(&sk->sk_lock.slock);
137 * Figure out, may we reply to this packet with icmp error.
139 * We do not reply, if:
140 * - it was icmp error message.
141 * - it is truncated, so that it is known, that protocol is ICMPV6
142 * (i.e. in the middle of some exthdr)
147 static bool is_ineligible(const struct sk_buff *skb)
149 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
150 int len = skb->len - ptr;
151 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
157 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
160 if (nexthdr == IPPROTO_ICMPV6) {
162 tp = skb_header_pointer(skb,
163 ptr+offsetof(struct icmp6hdr, icmp6_type),
164 sizeof(_type), &_type);
165 if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
171 static bool icmpv6_mask_allow(int type)
173 /* Informational messages are not limited. */
174 if (type & ICMPV6_INFOMSG_MASK)
177 /* Do not limit pmtu discovery, it would break it. */
178 if (type == ICMPV6_PKT_TOOBIG)
184 static bool icmpv6_global_allow(int type)
186 if (icmpv6_mask_allow(type))
189 if (icmp_global_allow())
196 * Check the ICMP output rate limit
198 static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
201 struct net *net = sock_net(sk);
202 struct dst_entry *dst;
205 if (icmpv6_mask_allow(type))
209 * Look up the output route.
210 * XXX: perhaps the expire for routing entries cloned by
211 * this lookup should be more aggressive (not longer than timeout).
213 dst = ip6_route_output(net, sk, fl6);
215 IP6_INC_STATS(net, ip6_dst_idev(dst),
216 IPSTATS_MIB_OUTNOROUTES);
217 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
220 struct rt6_info *rt = (struct rt6_info *)dst;
221 int tmo = net->ipv6.sysctl.icmpv6_time;
222 struct inet_peer *peer;
224 /* Give more bandwidth to wider prefixes. */
225 if (rt->rt6i_dst.plen < 128)
226 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
228 peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1);
229 res = inet_peer_xrlim_allow(peer, tmo);
238 * an inline helper for the "simple" if statement below
239 * checks if parameter problem report is caused by an
240 * unrecognized IPv6 option that has the Option Type
241 * highest-order two bits set to 10
244 static bool opt_unrec(struct sk_buff *skb, __u32 offset)
248 offset += skb_network_offset(skb);
249 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
252 return (*op & 0xC0) == 0x80;
255 void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
256 struct icmp6hdr *thdr, int len)
259 struct icmp6hdr *icmp6h;
261 skb = skb_peek(&sk->sk_write_queue);
265 icmp6h = icmp6_hdr(skb);
266 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
267 icmp6h->icmp6_cksum = 0;
269 if (skb_queue_len(&sk->sk_write_queue) == 1) {
270 skb->csum = csum_partial(icmp6h,
271 sizeof(struct icmp6hdr), skb->csum);
272 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
274 len, fl6->flowi6_proto,
279 skb_queue_walk(&sk->sk_write_queue, skb) {
280 tmp_csum = csum_add(tmp_csum, skb->csum);
283 tmp_csum = csum_partial(icmp6h,
284 sizeof(struct icmp6hdr), tmp_csum);
285 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
287 len, fl6->flowi6_proto,
290 ip6_push_pending_frames(sk);
299 static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
301 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
302 struct sk_buff *org_skb = msg->skb;
305 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
307 skb->csum = csum_block_add(skb->csum, csum, odd);
308 if (!(msg->type & ICMPV6_INFOMSG_MASK))
309 nf_ct_attach(skb, org_skb);
313 #if IS_ENABLED(CONFIG_IPV6_MIP6)
314 static void mip6_addr_swap(struct sk_buff *skb)
316 struct ipv6hdr *iph = ipv6_hdr(skb);
317 struct inet6_skb_parm *opt = IP6CB(skb);
318 struct ipv6_destopt_hao *hao;
323 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
324 if (likely(off >= 0)) {
325 hao = (struct ipv6_destopt_hao *)
326 (skb_network_header(skb) + off);
328 iph->saddr = hao->addr;
334 static inline void mip6_addr_swap(struct sk_buff *skb) {}
337 static struct dst_entry *icmpv6_route_lookup(struct net *net,
342 struct dst_entry *dst, *dst2;
346 err = ip6_dst_lookup(net, sk, &dst, fl6);
351 * We won't send icmp if the destination is known
354 if (ipv6_anycast_destination(dst, &fl6->daddr)) {
355 net_dbg_ratelimited("icmp6_send: acast source\n");
357 return ERR_PTR(-EINVAL);
360 /* No need to clone since we're just using its address. */
363 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
368 if (PTR_ERR(dst) == -EPERM)
374 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
376 goto relookup_failed;
378 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
380 goto relookup_failed;
382 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
392 goto relookup_failed;
401 static int icmp6_iif(const struct sk_buff *skb)
403 int iif = skb->dev->ifindex;
405 /* for local traffic to local address, skb dev is the loopback
406 * device. Check if there is a dst attached to the skb and if so
407 * get the real device index. Same is needed for replies to a link
408 * local address on a device enslaved to an L3 master device
410 if (unlikely(iif == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {
411 const struct rt6_info *rt6 = skb_rt6_info(skb);
414 iif = rt6->rt6i_idev->dev->ifindex;
421 * Send an ICMP message in response to a packet in error
423 static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
424 const struct in6_addr *force_saddr)
426 struct net *net = dev_net(skb->dev);
427 struct inet6_dev *idev = NULL;
428 struct ipv6hdr *hdr = ipv6_hdr(skb);
430 struct ipv6_pinfo *np;
431 const struct in6_addr *saddr = NULL;
432 struct dst_entry *dst;
433 struct icmp6hdr tmp_hdr;
435 struct icmpv6_msg msg;
436 struct ipcm6_cookie ipc6;
440 u32 mark = IP6_REPLY_MARK(net, skb->mark);
442 if ((u8 *)hdr < skb->head ||
443 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
447 * Make sure we respect the rules
448 * i.e. RFC 1885 2.4(e)
449 * Rule (e.1) is enforced by not using icmp6_send
450 * in any code that processes icmp errors.
452 addr_type = ipv6_addr_type(&hdr->daddr);
454 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
455 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
462 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
463 if (type != ICMPV6_PKT_TOOBIG &&
464 !(type == ICMPV6_PARAMPROB &&
465 code == ICMPV6_UNK_OPTION &&
466 (opt_unrec(skb, info))))
472 addr_type = ipv6_addr_type(&hdr->saddr);
478 if (__ipv6_addr_needs_scope_id(addr_type)) {
479 iif = icmp6_iif(skb);
482 iif = l3mdev_master_ifindex(dst ? dst->dev : skb->dev);
486 * Must not send error if the source does not uniquely
487 * identify a single node (RFC2463 Section 2.4).
488 * We check unspecified / multicast addresses here,
489 * and anycast addresses will be checked later.
491 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
492 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
493 &hdr->saddr, &hdr->daddr);
498 * Never answer to a ICMP packet.
500 if (is_ineligible(skb)) {
501 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
502 &hdr->saddr, &hdr->daddr);
506 /* Needed by both icmp_global_allow and icmpv6_xmit_lock */
509 /* Check global sysctl_icmp_msgs_per_sec ratelimit */
510 if (!(skb->dev->flags&IFF_LOOPBACK) && !icmpv6_global_allow(type))
515 memset(&fl6, 0, sizeof(fl6));
516 fl6.flowi6_proto = IPPROTO_ICMPV6;
517 fl6.daddr = hdr->saddr;
522 fl6.flowi6_mark = mark;
523 fl6.flowi6_oif = iif;
524 fl6.fl6_icmp_type = type;
525 fl6.fl6_icmp_code = code;
526 fl6.flowi6_uid = sock_net_uid(net, NULL);
527 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
528 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
530 sk = icmpv6_xmit_lock(net);
537 if (!icmpv6_xrlim_allow(sk, type, &fl6))
540 tmp_hdr.icmp6_type = type;
541 tmp_hdr.icmp6_code = code;
542 tmp_hdr.icmp6_cksum = 0;
543 tmp_hdr.icmp6_pointer = htonl(info);
545 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
546 fl6.flowi6_oif = np->mcast_oif;
547 else if (!fl6.flowi6_oif)
548 fl6.flowi6_oif = np->ucast_oif;
550 ipcm6_init_sk(&ipc6, np);
551 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
553 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
557 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
560 msg.offset = skb_network_offset(skb);
563 len = skb->len - msg.offset;
564 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
566 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
567 &hdr->saddr, &hdr->daddr);
568 goto out_dst_release;
572 idev = __in6_dev_get(skb->dev);
574 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
575 len + sizeof(struct icmp6hdr),
576 sizeof(struct icmp6hdr),
577 &ipc6, &fl6, (struct rt6_info *)dst,
579 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
580 ip6_flush_pending_frames(sk);
582 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
583 len + sizeof(struct icmp6hdr));
589 icmpv6_xmit_unlock(sk);
594 /* Slightly more convenient version of icmp6_send.
596 void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
598 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
602 /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
603 * if sufficient data bytes are available
604 * @nhs is the size of the tunnel header(s) :
605 * Either an IPv4 header for SIT encap
606 * an IPv4 header + GRE header for GRE encap
608 int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
609 unsigned int data_len)
611 struct in6_addr temp_saddr;
613 struct sk_buff *skb2;
616 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
619 /* RFC 4884 (partial) support for ICMP extensions */
620 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
623 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
630 skb_reset_network_header(skb2);
632 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
635 if (rt && rt->dst.dev)
636 skb2->dev = rt->dst.dev;
638 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
641 /* RFC 4884 (partial) support :
642 * insert 0 padding at the end, before the extensions
644 __skb_push(skb2, nhs);
645 skb_reset_network_header(skb2);
646 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
647 memset(skb2->data + data_len - nhs, 0, nhs);
648 /* RFC 4884 4.5 : Length is measured in 64-bit words,
649 * and stored in reserved[0]
651 info = (data_len/8) << 24;
653 if (type == ICMP_TIME_EXCEEDED)
654 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
657 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
666 EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
668 static void icmpv6_echo_reply(struct sk_buff *skb)
670 struct net *net = dev_net(skb->dev);
672 struct inet6_dev *idev;
673 struct ipv6_pinfo *np;
674 const struct in6_addr *saddr = NULL;
675 struct icmp6hdr *icmph = icmp6_hdr(skb);
676 struct icmp6hdr tmp_hdr;
678 struct icmpv6_msg msg;
679 struct dst_entry *dst;
680 struct ipcm6_cookie ipc6;
681 u32 mark = IP6_REPLY_MARK(net, skb->mark);
683 saddr = &ipv6_hdr(skb)->daddr;
685 if (!ipv6_unicast_destination(skb) &&
686 !(net->ipv6.sysctl.anycast_src_echo_reply &&
687 ipv6_anycast_destination(skb_dst(skb), saddr)))
690 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
691 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
693 memset(&fl6, 0, sizeof(fl6));
694 fl6.flowi6_proto = IPPROTO_ICMPV6;
695 fl6.daddr = ipv6_hdr(skb)->saddr;
698 fl6.flowi6_oif = icmp6_iif(skb);
699 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
700 fl6.flowi6_mark = mark;
701 fl6.flowi6_uid = sock_net_uid(net, NULL);
702 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
705 sk = icmpv6_xmit_lock(net);
711 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
712 fl6.flowi6_oif = np->mcast_oif;
713 else if (!fl6.flowi6_oif)
714 fl6.flowi6_oif = np->ucast_oif;
716 if (ip6_dst_lookup(net, sk, &dst, &fl6))
718 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
722 idev = __in6_dev_get(skb->dev);
726 msg.type = ICMPV6_ECHO_REPLY;
728 ipcm6_init_sk(&ipc6, np);
729 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
730 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
732 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
733 skb->len + sizeof(struct icmp6hdr),
734 sizeof(struct icmp6hdr), &ipc6, &fl6,
735 (struct rt6_info *)dst, MSG_DONTWAIT)) {
736 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
737 ip6_flush_pending_frames(sk);
739 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
740 skb->len + sizeof(struct icmp6hdr));
744 icmpv6_xmit_unlock(sk);
749 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
751 const struct inet6_protocol *ipprot;
755 struct net *net = dev_net(skb->dev);
757 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
760 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
761 if (ipv6_ext_hdr(nexthdr)) {
762 /* now skip over extension headers */
763 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
764 &nexthdr, &frag_off);
765 if (inner_offset < 0)
768 inner_offset = sizeof(struct ipv6hdr);
771 /* Checkin header including 8 bytes of inner protocol header. */
772 if (!pskb_may_pull(skb, inner_offset+8))
775 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
776 Without this we will not able f.e. to make source routed
778 Corresponding argument (opt) to notifiers is already added.
782 ipprot = rcu_dereference(inet6_protos[nexthdr]);
783 if (ipprot && ipprot->err_handler)
784 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
786 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
790 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
794 * Handle icmp messages
797 static int icmpv6_rcv(struct sk_buff *skb)
799 struct net *net = dev_net(skb->dev);
800 struct net_device *dev = skb->dev;
801 struct inet6_dev *idev = __in6_dev_get(dev);
802 const struct in6_addr *saddr, *daddr;
803 struct icmp6hdr *hdr;
805 bool success = false;
807 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
808 struct sec_path *sp = skb_sec_path(skb);
811 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
815 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
818 nh = skb_network_offset(skb);
819 skb_set_network_header(skb, sizeof(*hdr));
821 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
824 skb_set_network_header(skb, nh);
827 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
829 saddr = &ipv6_hdr(skb)->saddr;
830 daddr = &ipv6_hdr(skb)->daddr;
832 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
833 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
838 if (!pskb_pull(skb, sizeof(*hdr)))
841 hdr = icmp6_hdr(skb);
843 type = hdr->icmp6_type;
845 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
848 case ICMPV6_ECHO_REQUEST:
849 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
850 icmpv6_echo_reply(skb);
853 case ICMPV6_ECHO_REPLY:
854 success = ping_rcv(skb);
857 case ICMPV6_PKT_TOOBIG:
858 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
859 standard destination cache. Seems, only "advanced"
860 destination cache will allow to solve this problem
863 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
865 hdr = icmp6_hdr(skb);
869 case ICMPV6_DEST_UNREACH:
870 case ICMPV6_TIME_EXCEED:
871 case ICMPV6_PARAMPROB:
872 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
875 case NDISC_ROUTER_SOLICITATION:
876 case NDISC_ROUTER_ADVERTISEMENT:
877 case NDISC_NEIGHBOUR_SOLICITATION:
878 case NDISC_NEIGHBOUR_ADVERTISEMENT:
883 case ICMPV6_MGM_QUERY:
884 igmp6_event_query(skb);
887 case ICMPV6_MGM_REPORT:
888 igmp6_event_report(skb);
891 case ICMPV6_MGM_REDUCTION:
892 case ICMPV6_NI_QUERY:
893 case ICMPV6_NI_REPLY:
894 case ICMPV6_MLD2_REPORT:
895 case ICMPV6_DHAAD_REQUEST:
896 case ICMPV6_DHAAD_REPLY:
897 case ICMPV6_MOBILE_PREFIX_SOL:
898 case ICMPV6_MOBILE_PREFIX_ADV:
903 if (type & ICMPV6_INFOMSG_MASK)
906 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
910 * error of unknown type.
911 * must pass to upper level
914 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
917 /* until the v6 path can be better sorted assume failure and
918 * preserve the status quo behaviour for the rest of the paths to here
928 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
930 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
936 void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
938 const struct in6_addr *saddr,
939 const struct in6_addr *daddr,
942 memset(fl6, 0, sizeof(*fl6));
945 fl6->flowi6_proto = IPPROTO_ICMPV6;
946 fl6->fl6_icmp_type = type;
947 fl6->fl6_icmp_code = 0;
948 fl6->flowi6_oif = oif;
949 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
952 static int __net_init icmpv6_sk_init(struct net *net)
958 kcalloc(nr_cpu_ids, sizeof(struct sock *), GFP_KERNEL);
959 if (!net->ipv6.icmp_sk)
962 for_each_possible_cpu(i) {
963 err = inet_ctl_sock_create(&sk, PF_INET6,
964 SOCK_RAW, IPPROTO_ICMPV6, net);
966 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
971 net->ipv6.icmp_sk[i] = sk;
973 /* Enough space for 2 64K ICMP packets, including
974 * sk_buff struct overhead.
976 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
981 for (j = 0; j < i; j++)
982 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
983 kfree(net->ipv6.icmp_sk);
987 static void __net_exit icmpv6_sk_exit(struct net *net)
991 for_each_possible_cpu(i) {
992 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
994 kfree(net->ipv6.icmp_sk);
997 static struct pernet_operations icmpv6_sk_ops = {
998 .init = icmpv6_sk_init,
999 .exit = icmpv6_sk_exit,
1002 int __init icmpv6_init(void)
1006 err = register_pernet_subsys(&icmpv6_sk_ops);
1011 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1014 err = inet6_register_icmp_sender(icmp6_send);
1016 goto sender_reg_err;
1020 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1022 pr_err("Failed to register ICMP6 protocol\n");
1023 unregister_pernet_subsys(&icmpv6_sk_ops);
1027 void icmpv6_cleanup(void)
1029 inet6_unregister_icmp_sender(icmp6_send);
1030 unregister_pernet_subsys(&icmpv6_sk_ops);
1031 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1035 static const struct icmp6_err {
1043 { /* ADM_PROHIBITED */
1047 { /* Was NOT_NEIGHBOUR, now reserved */
1048 .err = EHOSTUNREACH,
1051 { /* ADDR_UNREACH */
1052 .err = EHOSTUNREACH,
1055 { /* PORT_UNREACH */
1056 .err = ECONNREFUSED,
1063 { /* REJECT_ROUTE */
1069 int icmpv6_err_convert(u8 type, u8 code, int *err)
1076 case ICMPV6_DEST_UNREACH:
1078 if (code < ARRAY_SIZE(tab_unreach)) {
1079 *err = tab_unreach[code].err;
1080 fatal = tab_unreach[code].fatal;
1084 case ICMPV6_PKT_TOOBIG:
1088 case ICMPV6_PARAMPROB:
1093 case ICMPV6_TIME_EXCEED:
1094 *err = EHOSTUNREACH;
1100 EXPORT_SYMBOL(icmpv6_err_convert);
1102 #ifdef CONFIG_SYSCTL
1103 static struct ctl_table ipv6_icmp_table_template[] = {
1105 .procname = "ratelimit",
1106 .data = &init_net.ipv6.sysctl.icmpv6_time,
1107 .maxlen = sizeof(int),
1109 .proc_handler = proc_dointvec_ms_jiffies,
1112 .procname = "echo_ignore_all",
1113 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
1114 .maxlen = sizeof(int),
1116 .proc_handler = proc_dointvec,
1121 struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1123 struct ctl_table *table;
1125 table = kmemdup(ipv6_icmp_table_template,
1126 sizeof(ipv6_icmp_table_template),
1130 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1131 table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;