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1/*
2 * IPv6 input
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Ian P. Morris <I.P.Morris@soton.ac.uk>
8 *
9 * Based in linux/net/ipv4/ip_input.c
10 *
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.
15 */
16/* Changes
17 *
18 * Mitsuru KANDA @USAGI and
19 * YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
20 */
21
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>
32
33#include <linux/netfilter.h>
34#include <linux/netfilter_ipv6.h>
35
36#include <net/sock.h>
37#include <net/snmp.h>
38
39#include <net/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>
46#include <net/xfrm.h>
47#include <net/inet_ecn.h>
48#include <net/dst_metadata.h>
49
50int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
51{
52 if (net->ipv4.sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) {
53 const struct inet6_protocol *ipprot;
54
55 ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
56 if (ipprot && ipprot->early_demux)
57 ipprot->early_demux(skb);
58 }
59 if (!skb_valid_dst(skb))
60 ip6_route_input(skb);
61
62 return dst_input(skb);
63}
64
65int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
66{
67 const struct ipv6hdr *hdr;
68 u32 pkt_len;
69 struct inet6_dev *idev;
70 struct net *net = dev_net(skb->dev);
71
72 if (skb->pkt_type == PACKET_OTHERHOST) {
73 kfree_skb(skb);
74 return NET_RX_DROP;
75 }
76
77 rcu_read_lock();
78
79 idev = __in6_dev_get(skb->dev);
80
81 IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len);
82
83 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
84 !idev || unlikely(idev->cnf.disable_ipv6)) {
85 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
86 goto drop;
87 }
88
89 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
90
91 /*
92 * Store incoming device index. When the packet will
93 * be queued, we cannot refer to skb->dev anymore.
94 *
95 * BTW, when we send a packet for our own local address on a
96 * non-loopback interface (e.g. ethX), it is being delivered
97 * via the loopback interface (lo) here; skb->dev = loopback_dev.
98 * It, however, should be considered as if it is being
99 * arrived via the sending interface (ethX), because of the
100 * nature of scoping architecture. --yoshfuji
101 */
102 IP6CB(skb)->iif = skb_valid_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
103
104 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
105 goto err;
106
107 hdr = ipv6_hdr(skb);
108
109 if (hdr->version != 6)
110 goto err;
111
112 IP6_ADD_STATS_BH(net, idev,
113 IPSTATS_MIB_NOECTPKTS +
114 (ipv6_get_dsfield(hdr) & INET_ECN_MASK),
115 max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs));
116 /*
117 * RFC4291 2.5.3
118 * A packet received on an interface with a destination address
119 * of loopback must be dropped.
120 */
121 if (!(dev->flags & IFF_LOOPBACK) &&
122 ipv6_addr_loopback(&hdr->daddr))
123 goto err;
124
125 /* RFC4291 Errata ID: 3480
126 * Interface-Local scope spans only a single interface on a
127 * node and is useful only for loopback transmission of
128 * multicast. Packets with interface-local scope received
129 * from another node must be discarded.
130 */
131 if (!(skb->pkt_type == PACKET_LOOPBACK ||
132 dev->flags & IFF_LOOPBACK) &&
133 ipv6_addr_is_multicast(&hdr->daddr) &&
134 IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1)
135 goto err;
136
137 /* If enabled, drop unicast packets that were encapsulated in link-layer
138 * multicast or broadcast to protected against the so-called "hole-196"
139 * attack in 802.11 wireless.
140 */
141 if (!ipv6_addr_is_multicast(&hdr->daddr) &&
142 (skb->pkt_type == PACKET_BROADCAST ||
143 skb->pkt_type == PACKET_MULTICAST) &&
144 idev->cnf.drop_unicast_in_l2_multicast)
145 goto err;
146
147 /* RFC4291 2.7
148 * Nodes must not originate a packet to a multicast address whose scope
149 * field contains the reserved value 0; if such a packet is received, it
150 * must be silently dropped.
151 */
152 if (ipv6_addr_is_multicast(&hdr->daddr) &&
153 IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0)
154 goto err;
155
156 /*
157 * RFC4291 2.7
158 * Multicast addresses must not be used as source addresses in IPv6
159 * packets or appear in any Routing header.
160 */
161 if (ipv6_addr_is_multicast(&hdr->saddr))
162 goto err;
163
164 skb->transport_header = skb->network_header + sizeof(*hdr);
165 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
166
167 pkt_len = ntohs(hdr->payload_len);
168
169 /* pkt_len may be zero if Jumbo payload option is present */
170 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
171 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
172 IP6_INC_STATS_BH(net,
173 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
174 goto drop;
175 }
176 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
177 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
178 goto drop;
179 }
180 hdr = ipv6_hdr(skb);
181 }
182
183 if (hdr->nexthdr == NEXTHDR_HOP) {
184 if (ipv6_parse_hopopts(skb) < 0) {
185 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
186 rcu_read_unlock();
187 return NET_RX_DROP;
188 }
189 }
190
191 rcu_read_unlock();
192
193 /* Must drop socket now because of tproxy. */
194 skb_orphan(skb);
195
196 return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
197 net, NULL, skb, dev, NULL,
198 ip6_rcv_finish);
199err:
200 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
201drop:
202 rcu_read_unlock();
203 kfree_skb(skb);
204 return NET_RX_DROP;
205}
206
207/*
208 * Deliver the packet to the host
209 */
210
211
212static int ip6_input_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
213{
214 const struct inet6_protocol *ipprot;
215 struct inet6_dev *idev;
216 unsigned int nhoff;
217 int nexthdr;
218 bool raw;
219
220 /*
221 * Parse extension headers
222 */
223
224 rcu_read_lock();
225resubmit:
226 idev = ip6_dst_idev(skb_dst(skb));
227 if (!pskb_pull(skb, skb_transport_offset(skb)))
228 goto discard;
229 nhoff = IP6CB(skb)->nhoff;
230 nexthdr = skb_network_header(skb)[nhoff];
231
232 raw = raw6_local_deliver(skb, nexthdr);
233 ipprot = rcu_dereference(inet6_protos[nexthdr]);
234 if (ipprot) {
235 int ret;
236
237 if (ipprot->flags & INET6_PROTO_FINAL) {
238 const struct ipv6hdr *hdr;
239
240 /* Free reference early: we don't need it any more,
241 and it may hold ip_conntrack module loaded
242 indefinitely. */
243 nf_reset(skb);
244
245 skb_postpull_rcsum(skb, skb_network_header(skb),
246 skb_network_header_len(skb));
247 hdr = ipv6_hdr(skb);
248 if (ipv6_addr_is_multicast(&hdr->daddr) &&
249 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
250 &hdr->saddr) &&
251 !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
252 goto discard;
253 }
254 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
255 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
256 goto discard;
257
258 ret = ipprot->handler(skb);
259 if (ret > 0)
260 goto resubmit;
261 else if (ret == 0)
262 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
263 } else {
264 if (!raw) {
265 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
266 IP6_INC_STATS_BH(net, idev,
267 IPSTATS_MIB_INUNKNOWNPROTOS);
268 icmpv6_send(skb, ICMPV6_PARAMPROB,
269 ICMPV6_UNK_NEXTHDR, nhoff);
270 }
271 kfree_skb(skb);
272 } else {
273 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
274 consume_skb(skb);
275 }
276 }
277 rcu_read_unlock();
278 return 0;
279
280discard:
281 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
282 rcu_read_unlock();
283 kfree_skb(skb);
284 return 0;
285}
286
287
288int ip6_input(struct sk_buff *skb)
289{
290 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN,
291 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
292 ip6_input_finish);
293}
294
295int ip6_mc_input(struct sk_buff *skb)
296{
297 const struct ipv6hdr *hdr;
298 bool deliver;
299
300 IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev),
301 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
302 skb->len);
303
304 hdr = ipv6_hdr(skb);
305 deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
306
307#ifdef CONFIG_IPV6_MROUTE
308 /*
309 * IPv6 multicast router mode is now supported ;)
310 */
311 if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
312 !(ipv6_addr_type(&hdr->daddr) &
313 (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) &&
314 likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
315 /*
316 * Okay, we try to forward - split and duplicate
317 * packets.
318 */
319 struct sk_buff *skb2;
320 struct inet6_skb_parm *opt = IP6CB(skb);
321
322 /* Check for MLD */
323 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
324 /* Check if this is a mld message */
325 u8 nexthdr = hdr->nexthdr;
326 __be16 frag_off;
327 int offset;
328
329 /* Check if the value of Router Alert
330 * is for MLD (0x0000).
331 */
332 if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) {
333 deliver = false;
334
335 if (!ipv6_ext_hdr(nexthdr)) {
336 /* BUG */
337 goto out;
338 }
339 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
340 &nexthdr, &frag_off);
341 if (offset < 0)
342 goto out;
343
344 if (ipv6_is_mld(skb, nexthdr, offset))
345 deliver = true;
346
347 goto out;
348 }
349 /* unknown RA - process it normally */
350 }
351
352 if (deliver)
353 skb2 = skb_clone(skb, GFP_ATOMIC);
354 else {
355 skb2 = skb;
356 skb = NULL;
357 }
358
359 if (skb2) {
360 ip6_mr_input(skb2);
361 }
362 }
363out:
364#endif
365 if (likely(deliver))
366 ip6_input(skb);
367 else {
368 /* discard */
369 kfree_skb(skb);
370 }
371
372 return 0;
373}
1/*
2 * IPv6 input
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Ian P. Morris <I.P.Morris@soton.ac.uk>
8 *
9 * Based in linux/net/ipv4/ip_input.c
10 *
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.
15 */
16/* Changes
17 *
18 * Mitsuru KANDA @USAGI and
19 * YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
20 */
21
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>
32
33#include <linux/netfilter.h>
34#include <linux/netfilter_ipv6.h>
35
36#include <net/sock.h>
37#include <net/snmp.h>
38
39#include <net/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>
46#include <net/xfrm.h>
47#include <net/inet_ecn.h>
48#include <net/dst_metadata.h>
49
50int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
51{
52 /* if ingress device is enslaved to an L3 master device pass the
53 * skb to its handler for processing
54 */
55 skb = l3mdev_ip6_rcv(skb);
56 if (!skb)
57 return NET_RX_SUCCESS;
58
59 if (net->ipv4.sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) {
60 const struct inet6_protocol *ipprot;
61
62 ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
63 if (ipprot && ipprot->early_demux)
64 ipprot->early_demux(skb);
65 }
66 if (!skb_valid_dst(skb))
67 ip6_route_input(skb);
68
69 return dst_input(skb);
70}
71
72int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
73{
74 const struct ipv6hdr *hdr;
75 u32 pkt_len;
76 struct inet6_dev *idev;
77 struct net *net = dev_net(skb->dev);
78
79 if (skb->pkt_type == PACKET_OTHERHOST) {
80 kfree_skb(skb);
81 return NET_RX_DROP;
82 }
83
84 rcu_read_lock();
85
86 idev = __in6_dev_get(skb->dev);
87
88 __IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_IN, skb->len);
89
90 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
91 !idev || unlikely(idev->cnf.disable_ipv6)) {
92 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
93 goto drop;
94 }
95
96 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
97
98 /*
99 * Store incoming device index. When the packet will
100 * be queued, we cannot refer to skb->dev anymore.
101 *
102 * BTW, when we send a packet for our own local address on a
103 * non-loopback interface (e.g. ethX), it is being delivered
104 * via the loopback interface (lo) here; skb->dev = loopback_dev.
105 * It, however, should be considered as if it is being
106 * arrived via the sending interface (ethX), because of the
107 * nature of scoping architecture. --yoshfuji
108 */
109 IP6CB(skb)->iif = skb_valid_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
110
111 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
112 goto err;
113
114 hdr = ipv6_hdr(skb);
115
116 if (hdr->version != 6)
117 goto err;
118
119 __IP6_ADD_STATS(net, idev,
120 IPSTATS_MIB_NOECTPKTS +
121 (ipv6_get_dsfield(hdr) & INET_ECN_MASK),
122 max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs));
123 /*
124 * RFC4291 2.5.3
125 * A packet received on an interface with a destination address
126 * of loopback must be dropped.
127 */
128 if (!(dev->flags & IFF_LOOPBACK) &&
129 ipv6_addr_loopback(&hdr->daddr))
130 goto err;
131
132 /* RFC4291 Errata ID: 3480
133 * Interface-Local scope spans only a single interface on a
134 * node and is useful only for loopback transmission of
135 * multicast. Packets with interface-local scope received
136 * from another node must be discarded.
137 */
138 if (!(skb->pkt_type == PACKET_LOOPBACK ||
139 dev->flags & IFF_LOOPBACK) &&
140 ipv6_addr_is_multicast(&hdr->daddr) &&
141 IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1)
142 goto err;
143
144 /* If enabled, drop unicast packets that were encapsulated in link-layer
145 * multicast or broadcast to protected against the so-called "hole-196"
146 * attack in 802.11 wireless.
147 */
148 if (!ipv6_addr_is_multicast(&hdr->daddr) &&
149 (skb->pkt_type == PACKET_BROADCAST ||
150 skb->pkt_type == PACKET_MULTICAST) &&
151 idev->cnf.drop_unicast_in_l2_multicast)
152 goto err;
153
154 /* RFC4291 2.7
155 * Nodes must not originate a packet to a multicast address whose scope
156 * field contains the reserved value 0; if such a packet is received, it
157 * must be silently dropped.
158 */
159 if (ipv6_addr_is_multicast(&hdr->daddr) &&
160 IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0)
161 goto err;
162
163 /*
164 * RFC4291 2.7
165 * Multicast addresses must not be used as source addresses in IPv6
166 * packets or appear in any Routing header.
167 */
168 if (ipv6_addr_is_multicast(&hdr->saddr))
169 goto err;
170
171 skb->transport_header = skb->network_header + sizeof(*hdr);
172 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
173
174 pkt_len = ntohs(hdr->payload_len);
175
176 /* pkt_len may be zero if Jumbo payload option is present */
177 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
178 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
179 __IP6_INC_STATS(net,
180 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
181 goto drop;
182 }
183 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
184 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
185 goto drop;
186 }
187 hdr = ipv6_hdr(skb);
188 }
189
190 if (hdr->nexthdr == NEXTHDR_HOP) {
191 if (ipv6_parse_hopopts(skb) < 0) {
192 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
193 rcu_read_unlock();
194 return NET_RX_DROP;
195 }
196 }
197
198 rcu_read_unlock();
199
200 /* Must drop socket now because of tproxy. */
201 skb_orphan(skb);
202
203 return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
204 net, NULL, skb, dev, NULL,
205 ip6_rcv_finish);
206err:
207 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
208drop:
209 rcu_read_unlock();
210 kfree_skb(skb);
211 return NET_RX_DROP;
212}
213
214/*
215 * Deliver the packet to the host
216 */
217
218
219static int ip6_input_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
220{
221 const struct inet6_protocol *ipprot;
222 struct inet6_dev *idev;
223 unsigned int nhoff;
224 int nexthdr;
225 bool raw;
226 bool have_final = false;
227
228 /*
229 * Parse extension headers
230 */
231
232 rcu_read_lock();
233resubmit:
234 idev = ip6_dst_idev(skb_dst(skb));
235 if (!pskb_pull(skb, skb_transport_offset(skb)))
236 goto discard;
237 nhoff = IP6CB(skb)->nhoff;
238 nexthdr = skb_network_header(skb)[nhoff];
239
240resubmit_final:
241 raw = raw6_local_deliver(skb, nexthdr);
242 ipprot = rcu_dereference(inet6_protos[nexthdr]);
243 if (ipprot) {
244 int ret;
245
246 if (have_final) {
247 if (!(ipprot->flags & INET6_PROTO_FINAL)) {
248 /* Once we've seen a final protocol don't
249 * allow encapsulation on any non-final
250 * ones. This allows foo in UDP encapsulation
251 * to work.
252 */
253 goto discard;
254 }
255 } else if (ipprot->flags & INET6_PROTO_FINAL) {
256 const struct ipv6hdr *hdr;
257
258 /* Only do this once for first final protocol */
259 have_final = true;
260
261 /* Free reference early: we don't need it any more,
262 and it may hold ip_conntrack module loaded
263 indefinitely. */
264 nf_reset(skb);
265
266 skb_postpull_rcsum(skb, skb_network_header(skb),
267 skb_network_header_len(skb));
268 hdr = ipv6_hdr(skb);
269 if (ipv6_addr_is_multicast(&hdr->daddr) &&
270 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
271 &hdr->saddr) &&
272 !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
273 goto discard;
274 }
275 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
276 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
277 goto discard;
278
279 ret = ipprot->handler(skb);
280 if (ret > 0) {
281 if (ipprot->flags & INET6_PROTO_FINAL) {
282 /* Not an extension header, most likely UDP
283 * encapsulation. Use return value as nexthdr
284 * protocol not nhoff (which presumably is
285 * not set by handler).
286 */
287 nexthdr = ret;
288 goto resubmit_final;
289 } else {
290 goto resubmit;
291 }
292 } else if (ret == 0) {
293 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
294 }
295 } else {
296 if (!raw) {
297 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
298 __IP6_INC_STATS(net, idev,
299 IPSTATS_MIB_INUNKNOWNPROTOS);
300 icmpv6_send(skb, ICMPV6_PARAMPROB,
301 ICMPV6_UNK_NEXTHDR, nhoff);
302 }
303 kfree_skb(skb);
304 } else {
305 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
306 consume_skb(skb);
307 }
308 }
309 rcu_read_unlock();
310 return 0;
311
312discard:
313 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
314 rcu_read_unlock();
315 kfree_skb(skb);
316 return 0;
317}
318
319
320int ip6_input(struct sk_buff *skb)
321{
322 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN,
323 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
324 ip6_input_finish);
325}
326EXPORT_SYMBOL_GPL(ip6_input);
327
328int ip6_mc_input(struct sk_buff *skb)
329{
330 const struct ipv6hdr *hdr;
331 bool deliver;
332
333 __IP6_UPD_PO_STATS(dev_net(skb_dst(skb)->dev),
334 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
335 skb->len);
336
337 hdr = ipv6_hdr(skb);
338 deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
339
340#ifdef CONFIG_IPV6_MROUTE
341 /*
342 * IPv6 multicast router mode is now supported ;)
343 */
344 if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
345 !(ipv6_addr_type(&hdr->daddr) &
346 (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) &&
347 likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
348 /*
349 * Okay, we try to forward - split and duplicate
350 * packets.
351 */
352 struct sk_buff *skb2;
353 struct inet6_skb_parm *opt = IP6CB(skb);
354
355 /* Check for MLD */
356 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
357 /* Check if this is a mld message */
358 u8 nexthdr = hdr->nexthdr;
359 __be16 frag_off;
360 int offset;
361
362 /* Check if the value of Router Alert
363 * is for MLD (0x0000).
364 */
365 if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) {
366 deliver = false;
367
368 if (!ipv6_ext_hdr(nexthdr)) {
369 /* BUG */
370 goto out;
371 }
372 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
373 &nexthdr, &frag_off);
374 if (offset < 0)
375 goto out;
376
377 if (ipv6_is_mld(skb, nexthdr, offset))
378 deliver = true;
379
380 goto out;
381 }
382 /* unknown RA - process it normally */
383 }
384
385 if (deliver)
386 skb2 = skb_clone(skb, GFP_ATOMIC);
387 else {
388 skb2 = skb;
389 skb = NULL;
390 }
391
392 if (skb2) {
393 ip6_mr_input(skb2);
394 }
395 }
396out:
397#endif
398 if (likely(deliver))
399 ip6_input(skb);
400 else {
401 /* discard */
402 kfree_skb(skb);
403 }
404
405 return 0;
406}