Loading...
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
48
49
50inline int ip6_rcv_finish( struct sk_buff *skb)
51{
52 if (skb_dst(skb) == NULL)
53 ip6_route_input(skb);
54
55 return dst_input(skb);
56}
57
58int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
59{
60 const struct ipv6hdr *hdr;
61 u32 pkt_len;
62 struct inet6_dev *idev;
63 struct net *net = dev_net(skb->dev);
64
65 if (skb->pkt_type == PACKET_OTHERHOST) {
66 kfree_skb(skb);
67 return NET_RX_DROP;
68 }
69
70 rcu_read_lock();
71
72 idev = __in6_dev_get(skb->dev);
73
74 IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len);
75
76 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
77 !idev || unlikely(idev->cnf.disable_ipv6)) {
78 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
79 goto drop;
80 }
81
82 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
83
84 /*
85 * Store incoming device index. When the packet will
86 * be queued, we cannot refer to skb->dev anymore.
87 *
88 * BTW, when we send a packet for our own local address on a
89 * non-loopback interface (e.g. ethX), it is being delivered
90 * via the loopback interface (lo) here; skb->dev = loopback_dev.
91 * It, however, should be considered as if it is being
92 * arrived via the sending interface (ethX), because of the
93 * nature of scoping architecture. --yoshfuji
94 */
95 IP6CB(skb)->iif = skb_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
96
97 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
98 goto err;
99
100 hdr = ipv6_hdr(skb);
101
102 if (hdr->version != 6)
103 goto err;
104
105 /*
106 * RFC4291 2.5.3
107 * A packet received on an interface with a destination address
108 * of loopback must be dropped.
109 */
110 if (!(dev->flags & IFF_LOOPBACK) &&
111 ipv6_addr_loopback(&hdr->daddr))
112 goto err;
113
114 skb->transport_header = skb->network_header + sizeof(*hdr);
115 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
116
117 pkt_len = ntohs(hdr->payload_len);
118
119 /* pkt_len may be zero if Jumbo payload option is present */
120 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
121 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
122 IP6_INC_STATS_BH(net,
123 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
124 goto drop;
125 }
126 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
127 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
128 goto drop;
129 }
130 hdr = ipv6_hdr(skb);
131 }
132
133 if (hdr->nexthdr == NEXTHDR_HOP) {
134 if (ipv6_parse_hopopts(skb) < 0) {
135 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
136 rcu_read_unlock();
137 return NET_RX_DROP;
138 }
139 }
140
141 rcu_read_unlock();
142
143 /* Must drop socket now because of tproxy. */
144 skb_orphan(skb);
145
146 return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, dev, NULL,
147 ip6_rcv_finish);
148err:
149 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
150drop:
151 rcu_read_unlock();
152 kfree_skb(skb);
153 return NET_RX_DROP;
154}
155
156/*
157 * Deliver the packet to the host
158 */
159
160
161static int ip6_input_finish(struct sk_buff *skb)
162{
163 const struct inet6_protocol *ipprot;
164 unsigned int nhoff;
165 int nexthdr, raw;
166 u8 hash;
167 struct inet6_dev *idev;
168 struct net *net = dev_net(skb_dst(skb)->dev);
169
170 /*
171 * Parse extension headers
172 */
173
174 rcu_read_lock();
175resubmit:
176 idev = ip6_dst_idev(skb_dst(skb));
177 if (!pskb_pull(skb, skb_transport_offset(skb)))
178 goto discard;
179 nhoff = IP6CB(skb)->nhoff;
180 nexthdr = skb_network_header(skb)[nhoff];
181
182 raw = raw6_local_deliver(skb, nexthdr);
183
184 hash = nexthdr & (MAX_INET_PROTOS - 1);
185 if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
186 int ret;
187
188 if (ipprot->flags & INET6_PROTO_FINAL) {
189 const struct ipv6hdr *hdr;
190
191 /* Free reference early: we don't need it any more,
192 and it may hold ip_conntrack module loaded
193 indefinitely. */
194 nf_reset(skb);
195
196 skb_postpull_rcsum(skb, skb_network_header(skb),
197 skb_network_header_len(skb));
198 hdr = ipv6_hdr(skb);
199 if (ipv6_addr_is_multicast(&hdr->daddr) &&
200 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
201 &hdr->saddr) &&
202 !ipv6_is_mld(skb, nexthdr))
203 goto discard;
204 }
205 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
206 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
207 goto discard;
208
209 ret = ipprot->handler(skb);
210 if (ret > 0)
211 goto resubmit;
212 else if (ret == 0)
213 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
214 } else {
215 if (!raw) {
216 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
217 IP6_INC_STATS_BH(net, idev,
218 IPSTATS_MIB_INUNKNOWNPROTOS);
219 icmpv6_send(skb, ICMPV6_PARAMPROB,
220 ICMPV6_UNK_NEXTHDR, nhoff);
221 }
222 } else
223 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
224 kfree_skb(skb);
225 }
226 rcu_read_unlock();
227 return 0;
228
229discard:
230 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
231 rcu_read_unlock();
232 kfree_skb(skb);
233 return 0;
234}
235
236
237int ip6_input(struct sk_buff *skb)
238{
239 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
240 ip6_input_finish);
241}
242
243int ip6_mc_input(struct sk_buff *skb)
244{
245 const struct ipv6hdr *hdr;
246 int deliver;
247
248 IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev),
249 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
250 skb->len);
251
252 hdr = ipv6_hdr(skb);
253 deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
254
255#ifdef CONFIG_IPV6_MROUTE
256 /*
257 * IPv6 multicast router mode is now supported ;)
258 */
259 if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
260 !(ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) &&
261 likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
262 /*
263 * Okay, we try to forward - split and duplicate
264 * packets.
265 */
266 struct sk_buff *skb2;
267 struct inet6_skb_parm *opt = IP6CB(skb);
268
269 /* Check for MLD */
270 if (unlikely(opt->ra)) {
271 /* Check if this is a mld message */
272 u8 *ptr = skb_network_header(skb) + opt->ra;
273 struct icmp6hdr *icmp6;
274 u8 nexthdr = hdr->nexthdr;
275 int offset;
276
277 /* Check if the value of Router Alert
278 * is for MLD (0x0000).
279 */
280 if ((ptr[2] | ptr[3]) == 0) {
281 deliver = 0;
282
283 if (!ipv6_ext_hdr(nexthdr)) {
284 /* BUG */
285 goto out;
286 }
287 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
288 &nexthdr);
289 if (offset < 0)
290 goto out;
291
292 if (nexthdr != IPPROTO_ICMPV6)
293 goto out;
294
295 if (!pskb_may_pull(skb, (skb_network_header(skb) +
296 offset + 1 - skb->data)))
297 goto out;
298
299 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
300
301 switch (icmp6->icmp6_type) {
302 case ICMPV6_MGM_QUERY:
303 case ICMPV6_MGM_REPORT:
304 case ICMPV6_MGM_REDUCTION:
305 case ICMPV6_MLD2_REPORT:
306 deliver = 1;
307 break;
308 }
309 goto out;
310 }
311 /* unknown RA - process it normally */
312 }
313
314 if (deliver)
315 skb2 = skb_clone(skb, GFP_ATOMIC);
316 else {
317 skb2 = skb;
318 skb = NULL;
319 }
320
321 if (skb2) {
322 ip6_mr_input(skb2);
323 }
324 }
325out:
326#endif
327 if (likely(deliver))
328 ip6_input(skb);
329 else {
330 /* discard */
331 kfree_skb(skb);
332 }
333
334 return 0;
335}