]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blame - net/ipv6/ip6_input.c
netfilter: Pass struct net into the netfilter hooks
[mirror_ubuntu-artful-kernel.git] / net / ipv6 / ip6_input.c
CommitLineData
1da177e4
LT
1/*
2 * IPv6 input
1ab1457c 3 * Linux INET6 implementation
1da177e4
LT
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Ian P. Morris <I.P.Morris@soton.ac.uk>
8 *
1da177e4
LT
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 *
67ba4152
IM
18 * Mitsuru KANDA @USAGI and
19 * YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
1da177e4
LT
20 */
21
22#include <linux/errno.h>
23#include <linux/types.h>
24#include <linux/socket.h>
25#include <linux/sockios.h>
1da177e4
LT
26#include <linux/net.h>
27#include <linux/netdevice.h>
28#include <linux/in6.h>
29#include <linux/icmpv6.h>
7bc570c8 30#include <linux/mroute6.h>
5a0e3ad6 31#include <linux/slab.h>
1da177e4
LT
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>
1f07d03e 47#include <net/inet_ecn.h>
48fb6b55 48#include <net/dst_metadata.h>
1da177e4 49
7026b1dd 50int ip6_rcv_finish(struct sock *sk, struct sk_buff *skb)
1da177e4 51{
a452ce34 52 if (sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) {
c7109986
ED
53 const struct inet6_protocol *ipprot;
54
c7109986
ED
55 ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
56 if (ipprot && ipprot->early_demux)
57 ipprot->early_demux(skb);
c7109986 58 }
48fb6b55 59 if (!skb_valid_dst(skb))
1da177e4
LT
60 ip6_route_input(skb);
61
62 return dst_input(skb);
63}
64
f2ccd8fa 65int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
1da177e4 66{
b71d1d42 67 const struct ipv6hdr *hdr;
67ba4152 68 u32 pkt_len;
a11d206d 69 struct inet6_dev *idev;
483a47d2 70 struct net *net = dev_net(skb->dev);
1da177e4 71
a11d206d
YH
72 if (skb->pkt_type == PACKET_OTHERHOST) {
73 kfree_skb(skb);
5c91face 74 return NET_RX_DROP;
a11d206d
YH
75 }
76
77 rcu_read_lock();
1da177e4 78
a11d206d
YH
79 idev = __in6_dev_get(skb->dev);
80
edf391ff 81 IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len);
1da177e4 82
778d80be
YH
83 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
84 !idev || unlikely(idev->cnf.disable_ipv6)) {
483a47d2 85 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
71f6f6df 86 goto drop;
1da177e4
LT
87 }
88
6b7fdc3a
GC
89 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
90
1da177e4
LT
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
de3cb747 97 * via the loopback interface (lo) here; skb->dev = loopback_dev.
1da177e4
LT
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 */
48fb6b55 102 IP6CB(skb)->iif = skb_valid_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
1da177e4 103
2889139a 104 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
1da177e4
LT
105 goto err;
106
0660e03f 107 hdr = ipv6_hdr(skb);
1da177e4
LT
108
109 if (hdr->version != 6)
110 goto err;
111
9865249f 112 IP6_ADD_STATS_BH(net, idev,
1f07d03e
ED
113 IPSTATS_MIB_NOECTPKTS +
114 (ipv6_get_dsfield(hdr) & INET_ECN_MASK),
115 max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs));
f630e43a
YH
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
1c4a154e
HFS
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
20314092
HFS
137 /* RFC4291 2.7
138 * Nodes must not originate a packet to a multicast address whose scope
139 * field contains the reserved value 0; if such a packet is received, it
140 * must be silently dropped.
141 */
142 if (ipv6_addr_is_multicast(&hdr->daddr) &&
143 IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0)
144 goto err;
145
c457338d
BH
146 /*
147 * RFC4291 2.7
148 * Multicast addresses must not be used as source addresses in IPv6
149 * packets or appear in any Routing header.
150 */
151 if (ipv6_addr_is_multicast(&hdr->saddr))
152 goto err;
153
b0e380b1 154 skb->transport_header = skb->network_header + sizeof(*hdr);
951dbc8a
PM
155 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
156
1da177e4
LT
157 pkt_len = ntohs(hdr->payload_len);
158
159 /* pkt_len may be zero if Jumbo payload option is present */
160 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
60e5c166 161 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
483a47d2
DL
162 IP6_INC_STATS_BH(net,
163 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
60e5c166
MC
164 goto drop;
165 }
1da177e4 166 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
483a47d2 167 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
1da177e4
LT
168 goto drop;
169 }
0660e03f 170 hdr = ipv6_hdr(skb);
1da177e4
LT
171 }
172
173 if (hdr->nexthdr == NEXTHDR_HOP) {
e5bbef20 174 if (ipv6_parse_hopopts(skb) < 0) {
483a47d2 175 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
a11d206d 176 rcu_read_unlock();
5c91face 177 return NET_RX_DROP;
1da177e4 178 }
1da177e4
LT
179 }
180
a11d206d
YH
181 rcu_read_unlock();
182
71f9dacd
HX
183 /* Must drop socket now because of tproxy. */
184 skb_orphan(skb);
185
29a26a56
EB
186 return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
187 net, NULL, skb, dev, NULL,
6e23ae2a 188 ip6_rcv_finish);
1da177e4 189err:
483a47d2 190 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
1da177e4 191drop:
a11d206d 192 rcu_read_unlock();
1da177e4 193 kfree_skb(skb);
5c91face 194 return NET_RX_DROP;
1da177e4
LT
195}
196
197/*
198 * Deliver the packet to the host
199 */
200
201
7026b1dd 202static int ip6_input_finish(struct sock *sk, struct sk_buff *skb)
1da177e4 203{
f9242b6b 204 struct net *net = dev_net(skb_dst(skb)->dev);
41135cc8 205 const struct inet6_protocol *ipprot;
f9242b6b 206 struct inet6_dev *idev;
1da177e4 207 unsigned int nhoff;
a50feda5
ED
208 int nexthdr;
209 bool raw;
1da177e4 210
1da177e4
LT
211 /*
212 * Parse extension headers
213 */
214
1da177e4 215 rcu_read_lock();
1b0ccfe5 216resubmit:
adf30907 217 idev = ip6_dst_idev(skb_dst(skb));
ea2ae17d 218 if (!pskb_pull(skb, skb_transport_offset(skb)))
1da177e4 219 goto discard;
951dbc8a 220 nhoff = IP6CB(skb)->nhoff;
d56f90a7 221 nexthdr = skb_network_header(skb)[nhoff];
1da177e4 222
69d6da0b 223 raw = raw6_local_deliver(skb, nexthdr);
e5d08d71 224 ipprot = rcu_dereference(inet6_protos[nexthdr]);
53b24b8f 225 if (ipprot) {
1da177e4 226 int ret;
1ab1457c 227
1da177e4 228 if (ipprot->flags & INET6_PROTO_FINAL) {
b71d1d42 229 const struct ipv6hdr *hdr;
1da177e4 230
9fb9cbb1
YK
231 /* Free reference early: we don't need it any more,
232 and it may hold ip_conntrack module loaded
233 indefinitely. */
234 nf_reset(skb);
235
d56f90a7 236 skb_postpull_rcsum(skb, skb_network_header(skb),
cfe1fc77 237 skb_network_header_len(skb));
0660e03f 238 hdr = ipv6_hdr(skb);
1da177e4
LT
239 if (ipv6_addr_is_multicast(&hdr->daddr) &&
240 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
241 &hdr->saddr) &&
daad1512 242 !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
1da177e4
LT
243 goto discard;
244 }
245 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
1ab1457c 246 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1da177e4 247 goto discard;
1ab1457c 248
e5bbef20 249 ret = ipprot->handler(skb);
1b0ccfe5 250 if (ret > 0)
1da177e4 251 goto resubmit;
1b0ccfe5 252 else if (ret == 0)
483a47d2 253 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
1da177e4 254 } else {
69d6da0b 255 if (!raw) {
1da177e4 256 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
483a47d2
DL
257 IP6_INC_STATS_BH(net, idev,
258 IPSTATS_MIB_INUNKNOWNPROTOS);
fad87aca 259 icmpv6_send(skb, ICMPV6_PARAMPROB,
3ffe533c 260 ICMPV6_UNK_NEXTHDR, nhoff);
1da177e4 261 }
d8c6f4b9
NH
262 kfree_skb(skb);
263 } else {
483a47d2 264 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
d8c6f4b9
NH
265 consume_skb(skb);
266 }
1da177e4
LT
267 }
268 rcu_read_unlock();
269 return 0;
270
271discard:
483a47d2 272 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
1da177e4
LT
273 rcu_read_unlock();
274 kfree_skb(skb);
275 return 0;
276}
277
278
279int ip6_input(struct sk_buff *skb)
280{
29a26a56
EB
281 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN,
282 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
6e23ae2a 283 ip6_input_finish);
1da177e4
LT
284}
285
286int ip6_mc_input(struct sk_buff *skb)
287{
b71d1d42 288 const struct ipv6hdr *hdr;
a50feda5 289 bool deliver;
1da177e4 290
adf30907
ED
291 IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev),
292 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
edf391ff 293 skb->len);
1da177e4 294
0660e03f 295 hdr = ipv6_hdr(skb);
4c7966b8 296 deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
1da177e4 297
7bc570c8 298#ifdef CONFIG_IPV6_MROUTE
1da177e4 299 /*
7bc570c8 300 * IPv6 multicast router mode is now supported ;)
1da177e4 301 */
53b7997f 302 if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
ddf64354
HFS
303 !(ipv6_addr_type(&hdr->daddr) &
304 (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) &&
7bc570c8
YH
305 likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
306 /*
307 * Okay, we try to forward - split and duplicate
308 * packets.
309 */
310 struct sk_buff *skb2;
311 struct inet6_skb_parm *opt = IP6CB(skb);
312
313 /* Check for MLD */
dd3332bf 314 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
7bc570c8 315 /* Check if this is a mld message */
7bc570c8 316 u8 nexthdr = hdr->nexthdr;
75f2811c 317 __be16 frag_off;
7bc570c8
YH
318 int offset;
319
320 /* Check if the value of Router Alert
321 * is for MLD (0x0000).
322 */
dd3332bf 323 if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) {
a50feda5 324 deliver = false;
aba6096b 325
7bc570c8
YH
326 if (!ipv6_ext_hdr(nexthdr)) {
327 /* BUG */
aba6096b 328 goto out;
7bc570c8
YH
329 }
330 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
75f2811c 331 &nexthdr, &frag_off);
7bc570c8 332 if (offset < 0)
aba6096b 333 goto out;
7bc570c8 334
4c938d22
A
335 if (ipv6_is_mld(skb, nexthdr, offset))
336 deliver = true;
7bc570c8 337
4c938d22 338 goto out;
7bc570c8
YH
339 }
340 /* unknown RA - process it normally */
341 }
1da177e4 342
7bc570c8
YH
343 if (deliver)
344 skb2 = skb_clone(skb, GFP_ATOMIC);
345 else {
346 skb2 = skb;
347 skb = NULL;
348 }
1ab1457c 349
7bc570c8 350 if (skb2) {
7bc570c8 351 ip6_mr_input(skb2);
1da177e4
LT
352 }
353 }
7bc570c8 354out:
aba6096b
YH
355#endif
356 if (likely(deliver))
1da177e4 357 ip6_input(skb);
aba6096b
YH
358 else {
359 /* discard */
360 kfree_skb(skb);
1da177e4 361 }
1da177e4
LT
362
363 return 0;
364}