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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 void (*edemux)(struct sk_buff *skb);
53
54 /* if ingress device is enslaved to an L3 master device pass the
55 * skb to its handler for processing
56 */
57 skb = l3mdev_ip6_rcv(skb);
58 if (!skb)
59 return NET_RX_SUCCESS;
60
61 if (net->ipv4.sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) {
62 const struct inet6_protocol *ipprot;
63
64 ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
65 if (ipprot && (edemux = READ_ONCE(ipprot->early_demux)))
66 edemux(skb);
67 }
68 if (!skb_valid_dst(skb))
69 ip6_route_input(skb);
70
71 return dst_input(skb);
72}
73
74int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
75{
76 const struct ipv6hdr *hdr;
77 u32 pkt_len;
78 struct inet6_dev *idev;
79 struct net *net = dev_net(skb->dev);
80
81 if (skb->pkt_type == PACKET_OTHERHOST) {
82 kfree_skb(skb);
83 return NET_RX_DROP;
84 }
85
86 rcu_read_lock();
87
88 idev = __in6_dev_get(skb->dev);
89
90 __IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_IN, skb->len);
91
92 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
93 !idev || unlikely(idev->cnf.disable_ipv6)) {
94 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
95 goto drop;
96 }
97
98 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
99
100 /*
101 * Store incoming device index. When the packet will
102 * be queued, we cannot refer to skb->dev anymore.
103 *
104 * BTW, when we send a packet for our own local address on a
105 * non-loopback interface (e.g. ethX), it is being delivered
106 * via the loopback interface (lo) here; skb->dev = loopback_dev.
107 * It, however, should be considered as if it is being
108 * arrived via the sending interface (ethX), because of the
109 * nature of scoping architecture. --yoshfuji
110 */
111 IP6CB(skb)->iif = skb_valid_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
112
113 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
114 goto err;
115
116 hdr = ipv6_hdr(skb);
117
118 if (hdr->version != 6)
119 goto err;
120
121 __IP6_ADD_STATS(net, idev,
122 IPSTATS_MIB_NOECTPKTS +
123 (ipv6_get_dsfield(hdr) & INET_ECN_MASK),
124 max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs));
125 /*
126 * RFC4291 2.5.3
127 * The loopback address must not be used as the source address in IPv6
128 * packets that are sent outside of a single node. [..]
129 * A packet received on an interface with a destination address
130 * of loopback must be dropped.
131 */
132 if ((ipv6_addr_loopback(&hdr->saddr) ||
133 ipv6_addr_loopback(&hdr->daddr)) &&
134 !(dev->flags & IFF_LOOPBACK))
135 goto err;
136
137 /* RFC4291 Errata ID: 3480
138 * Interface-Local scope spans only a single interface on a
139 * node and is useful only for loopback transmission of
140 * multicast. Packets with interface-local scope received
141 * from another node must be discarded.
142 */
143 if (!(skb->pkt_type == PACKET_LOOPBACK ||
144 dev->flags & IFF_LOOPBACK) &&
145 ipv6_addr_is_multicast(&hdr->daddr) &&
146 IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1)
147 goto err;
148
149 /* If enabled, drop unicast packets that were encapsulated in link-layer
150 * multicast or broadcast to protected against the so-called "hole-196"
151 * attack in 802.11 wireless.
152 */
153 if (!ipv6_addr_is_multicast(&hdr->daddr) &&
154 (skb->pkt_type == PACKET_BROADCAST ||
155 skb->pkt_type == PACKET_MULTICAST) &&
156 idev->cnf.drop_unicast_in_l2_multicast)
157 goto err;
158
159 /* RFC4291 2.7
160 * Nodes must not originate a packet to a multicast address whose scope
161 * field contains the reserved value 0; if such a packet is received, it
162 * must be silently dropped.
163 */
164 if (ipv6_addr_is_multicast(&hdr->daddr) &&
165 IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0)
166 goto err;
167
168 /*
169 * RFC4291 2.7
170 * Multicast addresses must not be used as source addresses in IPv6
171 * packets or appear in any Routing header.
172 */
173 if (ipv6_addr_is_multicast(&hdr->saddr))
174 goto err;
175
176 skb->transport_header = skb->network_header + sizeof(*hdr);
177 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
178
179 pkt_len = ntohs(hdr->payload_len);
180
181 /* pkt_len may be zero if Jumbo payload option is present */
182 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
183 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
184 __IP6_INC_STATS(net,
185 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
186 goto drop;
187 }
188 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
189 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
190 goto drop;
191 }
192 hdr = ipv6_hdr(skb);
193 }
194
195 if (hdr->nexthdr == NEXTHDR_HOP) {
196 if (ipv6_parse_hopopts(skb) < 0) {
197 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
198 rcu_read_unlock();
199 return NET_RX_DROP;
200 }
201 }
202
203 rcu_read_unlock();
204
205 /* Must drop socket now because of tproxy. */
206 skb_orphan(skb);
207
208 return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
209 net, NULL, skb, dev, NULL,
210 ip6_rcv_finish);
211err:
212 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
213drop:
214 rcu_read_unlock();
215 kfree_skb(skb);
216 return NET_RX_DROP;
217}
218
219/*
220 * Deliver the packet to the host
221 */
222
223
224static int ip6_input_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
225{
226 const struct inet6_protocol *ipprot;
227 struct inet6_dev *idev;
228 unsigned int nhoff;
229 int nexthdr;
230 bool raw;
231 bool have_final = false;
232
233 /*
234 * Parse extension headers
235 */
236
237 rcu_read_lock();
238resubmit:
239 idev = ip6_dst_idev(skb_dst(skb));
240 if (!pskb_pull(skb, skb_transport_offset(skb)))
241 goto discard;
242 nhoff = IP6CB(skb)->nhoff;
243 nexthdr = skb_network_header(skb)[nhoff];
244
245resubmit_final:
246 raw = raw6_local_deliver(skb, nexthdr);
247 ipprot = rcu_dereference(inet6_protos[nexthdr]);
248 if (ipprot) {
249 int ret;
250
251 if (have_final) {
252 if (!(ipprot->flags & INET6_PROTO_FINAL)) {
253 /* Once we've seen a final protocol don't
254 * allow encapsulation on any non-final
255 * ones. This allows foo in UDP encapsulation
256 * to work.
257 */
258 goto discard;
259 }
260 } else if (ipprot->flags & INET6_PROTO_FINAL) {
261 const struct ipv6hdr *hdr;
262
263 /* Only do this once for first final protocol */
264 have_final = true;
265
266 /* Free reference early: we don't need it any more,
267 and it may hold ip_conntrack module loaded
268 indefinitely. */
269 nf_reset(skb);
270
271 skb_postpull_rcsum(skb, skb_network_header(skb),
272 skb_network_header_len(skb));
273 hdr = ipv6_hdr(skb);
274 if (ipv6_addr_is_multicast(&hdr->daddr) &&
275 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
276 &hdr->saddr) &&
277 !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
278 goto discard;
279 }
280 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
281 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
282 goto discard;
283
284 ret = ipprot->handler(skb);
285 if (ret > 0) {
286 if (ipprot->flags & INET6_PROTO_FINAL) {
287 /* Not an extension header, most likely UDP
288 * encapsulation. Use return value as nexthdr
289 * protocol not nhoff (which presumably is
290 * not set by handler).
291 */
292 nexthdr = ret;
293 goto resubmit_final;
294 } else {
295 goto resubmit;
296 }
297 } else if (ret == 0) {
298 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
299 }
300 } else {
301 if (!raw) {
302 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
303 __IP6_INC_STATS(net, idev,
304 IPSTATS_MIB_INUNKNOWNPROTOS);
305 icmpv6_send(skb, ICMPV6_PARAMPROB,
306 ICMPV6_UNK_NEXTHDR, nhoff);
307 }
308 kfree_skb(skb);
309 } else {
310 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
311 consume_skb(skb);
312 }
313 }
314 rcu_read_unlock();
315 return 0;
316
317discard:
318 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
319 rcu_read_unlock();
320 kfree_skb(skb);
321 return 0;
322}
323
324
325int ip6_input(struct sk_buff *skb)
326{
327 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN,
328 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
329 ip6_input_finish);
330}
331EXPORT_SYMBOL_GPL(ip6_input);
332
333int ip6_mc_input(struct sk_buff *skb)
334{
335 const struct ipv6hdr *hdr;
336 bool deliver;
337
338 __IP6_UPD_PO_STATS(dev_net(skb_dst(skb)->dev),
339 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
340 skb->len);
341
342 hdr = ipv6_hdr(skb);
343 deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
344
345#ifdef CONFIG_IPV6_MROUTE
346 /*
347 * IPv6 multicast router mode is now supported ;)
348 */
349 if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
350 !(ipv6_addr_type(&hdr->daddr) &
351 (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) &&
352 likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
353 /*
354 * Okay, we try to forward - split and duplicate
355 * packets.
356 */
357 struct sk_buff *skb2;
358 struct inet6_skb_parm *opt = IP6CB(skb);
359
360 /* Check for MLD */
361 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
362 /* Check if this is a mld message */
363 u8 nexthdr = hdr->nexthdr;
364 __be16 frag_off;
365 int offset;
366
367 /* Check if the value of Router Alert
368 * is for MLD (0x0000).
369 */
370 if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) {
371 deliver = false;
372
373 if (!ipv6_ext_hdr(nexthdr)) {
374 /* BUG */
375 goto out;
376 }
377 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
378 &nexthdr, &frag_off);
379 if (offset < 0)
380 goto out;
381
382 if (ipv6_is_mld(skb, nexthdr, offset))
383 deliver = true;
384
385 goto out;
386 }
387 /* unknown RA - process it normally */
388 }
389
390 if (deliver)
391 skb2 = skb_clone(skb, GFP_ATOMIC);
392 else {
393 skb2 = skb;
394 skb = NULL;
395 }
396
397 if (skb2) {
398 ip6_mr_input(skb2);
399 }
400 }
401out:
402#endif
403 if (likely(deliver))
404 ip6_input(skb);
405 else {
406 /* discard */
407 kfree_skb(skb);
408 }
409
410 return 0;
411}
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}