3 * Linux INET6 implementation
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Ian P. Morris <I.P.Morris@soton.ac.uk>
9 * Based in linux/net/ipv4/ip_input.c
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
18 * Mitsuru KANDA @USAGI and
19 * YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
22 #include <linux/errno.h>
23 #include <linux/types.h>
24 #include <linux/socket.h>
25 #include <linux/sockios.h>
26 #include <linux/net.h>
27 #include <linux/netdevice.h>
28 #include <linux/in6.h>
29 #include <linux/icmpv6.h>
30 #include <linux/mroute6.h>
31 #include <linux/slab.h>
33 #include <linux/netfilter.h>
34 #include <linux/netfilter_ipv6.h>
40 #include <net/protocol.h>
41 #include <net/transp_v6.h>
42 #include <net/rawv6.h>
43 #include <net/ndisc.h>
44 #include <net/ip6_route.h>
45 #include <net/addrconf.h>
50 int ip6_rcv_finish(struct sk_buff *skb)
52 if (sysctl_ip_early_demux && !skb_dst(skb)) {
53 const struct inet6_protocol *ipprot;
56 ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
57 if (ipprot && ipprot->early_demux)
58 ipprot->early_demux(skb);
64 return dst_input(skb);
67 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
69 const struct ipv6hdr *hdr;
71 struct inet6_dev *idev;
72 struct net *net = dev_net(skb->dev);
74 if (skb->pkt_type == PACKET_OTHERHOST) {
81 idev = __in6_dev_get(skb->dev);
83 IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len);
85 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
86 !idev || unlikely(idev->cnf.disable_ipv6)) {
87 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
91 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
94 * Store incoming device index. When the packet will
95 * be queued, we cannot refer to skb->dev anymore.
97 * BTW, when we send a packet for our own local address on a
98 * non-loopback interface (e.g. ethX), it is being delivered
99 * via the loopback interface (lo) here; skb->dev = loopback_dev.
100 * It, however, should be considered as if it is being
101 * arrived via the sending interface (ethX), because of the
102 * nature of scoping architecture. --yoshfuji
104 IP6CB(skb)->iif = skb_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
106 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
111 if (hdr->version != 6)
116 * A packet received on an interface with a destination address
117 * of loopback must be dropped.
119 if (!(dev->flags & IFF_LOOPBACK) &&
120 ipv6_addr_loopback(&hdr->daddr))
125 * Multicast addresses must not be used as source addresses in IPv6
126 * packets or appear in any Routing header.
128 if (ipv6_addr_is_multicast(&hdr->saddr))
131 skb->transport_header = skb->network_header + sizeof(*hdr);
132 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
134 pkt_len = ntohs(hdr->payload_len);
136 /* pkt_len may be zero if Jumbo payload option is present */
137 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
138 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
139 IP6_INC_STATS_BH(net,
140 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
143 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
144 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
150 if (hdr->nexthdr == NEXTHDR_HOP) {
151 if (ipv6_parse_hopopts(skb) < 0) {
152 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
160 /* Must drop socket now because of tproxy. */
163 return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, dev, NULL,
166 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
174 * Deliver the packet to the host
178 static int ip6_input_finish(struct sk_buff *skb)
180 struct net *net = dev_net(skb_dst(skb)->dev);
181 const struct inet6_protocol *ipprot;
182 struct inet6_dev *idev;
188 * Parse extension headers
193 idev = ip6_dst_idev(skb_dst(skb));
194 if (!pskb_pull(skb, skb_transport_offset(skb)))
196 nhoff = IP6CB(skb)->nhoff;
197 nexthdr = skb_network_header(skb)[nhoff];
199 raw = raw6_local_deliver(skb, nexthdr);
200 if ((ipprot = rcu_dereference(inet6_protos[nexthdr])) != NULL) {
203 if (ipprot->flags & INET6_PROTO_FINAL) {
204 const struct ipv6hdr *hdr;
206 /* Free reference early: we don't need it any more,
207 and it may hold ip_conntrack module loaded
211 skb_postpull_rcsum(skb, skb_network_header(skb),
212 skb_network_header_len(skb));
214 if (ipv6_addr_is_multicast(&hdr->daddr) &&
215 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
217 !ipv6_is_mld(skb, nexthdr))
220 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
221 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
224 ret = ipprot->handler(skb);
228 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
231 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
232 IP6_INC_STATS_BH(net, idev,
233 IPSTATS_MIB_INUNKNOWNPROTOS);
234 icmpv6_send(skb, ICMPV6_PARAMPROB,
235 ICMPV6_UNK_NEXTHDR, nhoff);
238 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
245 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
252 int ip6_input(struct sk_buff *skb)
254 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
258 int ip6_mc_input(struct sk_buff *skb)
260 const struct ipv6hdr *hdr;
263 IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev),
264 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
268 deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
270 #ifdef CONFIG_IPV6_MROUTE
272 * IPv6 multicast router mode is now supported ;)
274 if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
275 !(ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) &&
276 likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
278 * Okay, we try to forward - split and duplicate
281 struct sk_buff *skb2;
282 struct inet6_skb_parm *opt = IP6CB(skb);
285 if (unlikely(opt->ra)) {
286 /* Check if this is a mld message */
287 u8 *ptr = skb_network_header(skb) + opt->ra;
288 struct icmp6hdr *icmp6;
289 u8 nexthdr = hdr->nexthdr;
293 /* Check if the value of Router Alert
294 * is for MLD (0x0000).
296 if ((ptr[2] | ptr[3]) == 0) {
299 if (!ipv6_ext_hdr(nexthdr)) {
303 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
304 &nexthdr, &frag_off);
308 if (nexthdr != IPPROTO_ICMPV6)
311 if (!pskb_may_pull(skb, (skb_network_header(skb) +
312 offset + 1 - skb->data)))
315 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
317 switch (icmp6->icmp6_type) {
318 case ICMPV6_MGM_QUERY:
319 case ICMPV6_MGM_REPORT:
320 case ICMPV6_MGM_REDUCTION:
321 case ICMPV6_MLD2_REPORT:
327 /* unknown RA - process it normally */
331 skb2 = skb_clone(skb, GFP_ATOMIC);