powerpc/kconfig: Kill PPC_MULTIPLATFORM
[deliverable/linux.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 *
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>
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>
1da177e4
LT
31
32#include <linux/netfilter.h>
33#include <linux/netfilter_ipv6.h>
34
35#include <net/sock.h>
36#include <net/snmp.h>
37
38#include <net/ipv6.h>
39#include <net/protocol.h>
40#include <net/transp_v6.h>
41#include <net/rawv6.h>
42#include <net/ndisc.h>
43#include <net/ip6_route.h>
44#include <net/addrconf.h>
45#include <net/xfrm.h>
46
47
48
1ab1457c 49inline int ip6_rcv_finish( struct sk_buff *skb)
1da177e4
LT
50{
51 if (skb->dst == NULL)
52 ip6_route_input(skb);
53
54 return dst_input(skb);
55}
56
f2ccd8fa 57int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
1da177e4
LT
58{
59 struct ipv6hdr *hdr;
60 u32 pkt_len;
a11d206d 61 struct inet6_dev *idev;
483a47d2 62 struct net *net = dev_net(skb->dev);
1da177e4 63
a11d206d
YH
64 if (skb->pkt_type == PACKET_OTHERHOST) {
65 kfree_skb(skb);
66 return 0;
67 }
68
69 rcu_read_lock();
1da177e4 70
a11d206d
YH
71 idev = __in6_dev_get(skb->dev);
72
483a47d2 73 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INRECEIVES);
1da177e4 74
778d80be
YH
75 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
76 !idev || unlikely(idev->cnf.disable_ipv6)) {
483a47d2 77 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
a11d206d 78 rcu_read_unlock();
1da177e4
LT
79 goto out;
80 }
81
6b7fdc3a
GC
82 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
83
1da177e4
LT
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
de3cb747 90 * via the loopback interface (lo) here; skb->dev = loopback_dev.
1da177e4
LT
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 */
7a3025b1 95 IP6CB(skb)->iif = skb->dst ? ip6_dst_idev(skb->dst)->dev->ifindex : dev->ifindex;
1da177e4 96
2889139a 97 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
1da177e4
LT
98 goto err;
99
0660e03f 100 hdr = ipv6_hdr(skb);
1da177e4
LT
101
102 if (hdr->version != 6)
103 goto err;
104
f630e43a
YH
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
b0e380b1 114 skb->transport_header = skb->network_header + sizeof(*hdr);
951dbc8a
PM
115 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
116
1da177e4
LT
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) {
60e5c166 121 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
483a47d2
DL
122 IP6_INC_STATS_BH(net,
123 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
60e5c166
MC
124 goto drop;
125 }
1da177e4 126 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
483a47d2 127 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
1da177e4
LT
128 goto drop;
129 }
0660e03f 130 hdr = ipv6_hdr(skb);
1da177e4
LT
131 }
132
133 if (hdr->nexthdr == NEXTHDR_HOP) {
e5bbef20 134 if (ipv6_parse_hopopts(skb) < 0) {
483a47d2 135 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
a11d206d 136 rcu_read_unlock();
1da177e4
LT
137 return 0;
138 }
1da177e4
LT
139 }
140
a11d206d
YH
141 rcu_read_unlock();
142
6e23ae2a
PM
143 return NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, dev, NULL,
144 ip6_rcv_finish);
1da177e4 145err:
483a47d2 146 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
1da177e4 147drop:
a11d206d 148 rcu_read_unlock();
1da177e4
LT
149 kfree_skb(skb);
150out:
151 return 0;
152}
153
154/*
155 * Deliver the packet to the host
156 */
157
158
ad643a79 159static int ip6_input_finish(struct sk_buff *skb)
1da177e4
LT
160{
161 struct inet6_protocol *ipprot;
1da177e4 162 unsigned int nhoff;
69d6da0b 163 int nexthdr, raw;
1da177e4 164 u8 hash;
a11d206d 165 struct inet6_dev *idev;
483a47d2 166 struct net *net = dev_net(skb->dst->dev);
1da177e4 167
1da177e4
LT
168 /*
169 * Parse extension headers
170 */
171
1da177e4
LT
172 rcu_read_lock();
173resubmit:
a11d206d 174 idev = ip6_dst_idev(skb->dst);
ea2ae17d 175 if (!pskb_pull(skb, skb_transport_offset(skb)))
1da177e4 176 goto discard;
951dbc8a 177 nhoff = IP6CB(skb)->nhoff;
d56f90a7 178 nexthdr = skb_network_header(skb)[nhoff];
1da177e4 179
69d6da0b 180 raw = raw6_local_deliver(skb, nexthdr);
1da177e4
LT
181
182 hash = nexthdr & (MAX_INET_PROTOS - 1);
183 if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
184 int ret;
1ab1457c 185
1da177e4 186 if (ipprot->flags & INET6_PROTO_FINAL) {
1ab1457c 187 struct ipv6hdr *hdr;
1da177e4 188
9fb9cbb1
YK
189 /* Free reference early: we don't need it any more,
190 and it may hold ip_conntrack module loaded
191 indefinitely. */
192 nf_reset(skb);
193
d56f90a7 194 skb_postpull_rcsum(skb, skb_network_header(skb),
cfe1fc77 195 skb_network_header_len(skb));
0660e03f 196 hdr = ipv6_hdr(skb);
1da177e4
LT
197 if (ipv6_addr_is_multicast(&hdr->daddr) &&
198 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
199 &hdr->saddr) &&
200 !ipv6_is_mld(skb, nexthdr))
201 goto discard;
202 }
203 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
1ab1457c 204 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1da177e4 205 goto discard;
1ab1457c 206
e5bbef20 207 ret = ipprot->handler(skb);
1da177e4
LT
208 if (ret > 0)
209 goto resubmit;
210 else if (ret == 0)
483a47d2 211 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
1da177e4 212 } else {
69d6da0b 213 if (!raw) {
1da177e4 214 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
483a47d2
DL
215 IP6_INC_STATS_BH(net, idev,
216 IPSTATS_MIB_INUNKNOWNPROTOS);
fad87aca 217 icmpv6_send(skb, ICMPV6_PARAMPROB,
1ab1457c
YH
218 ICMPV6_UNK_NEXTHDR, nhoff,
219 skb->dev);
1da177e4 220 }
fad87aca 221 } else
483a47d2 222 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
fad87aca 223 kfree_skb(skb);
1da177e4
LT
224 }
225 rcu_read_unlock();
226 return 0;
227
228discard:
483a47d2 229 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
1da177e4
LT
230 rcu_read_unlock();
231 kfree_skb(skb);
232 return 0;
233}
234
235
236int ip6_input(struct sk_buff *skb)
237{
6e23ae2a
PM
238 return NF_HOOK(PF_INET6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
239 ip6_input_finish);
1da177e4
LT
240}
241
242int ip6_mc_input(struct sk_buff *skb)
243{
244 struct ipv6hdr *hdr;
245 int deliver;
246
483a47d2
DL
247 IP6_INC_STATS_BH(dev_net(skb->dst->dev),
248 ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS);
1da177e4 249
0660e03f 250 hdr = ipv6_hdr(skb);
4c7966b8 251 deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
1da177e4 252
7bc570c8 253#ifdef CONFIG_IPV6_MROUTE
1da177e4 254 /*
7bc570c8 255 * IPv6 multicast router mode is now supported ;)
1da177e4 256 */
53b7997f 257 if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
1d6e55f1 258 !(ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) &&
7bc570c8
YH
259 likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
260 /*
261 * Okay, we try to forward - split and duplicate
262 * packets.
263 */
264 struct sk_buff *skb2;
265 struct inet6_skb_parm *opt = IP6CB(skb);
266
267 /* Check for MLD */
268 if (unlikely(opt->ra)) {
269 /* Check if this is a mld message */
270 u8 *ptr = skb_network_header(skb) + opt->ra;
271 struct icmp6hdr *icmp6;
272 u8 nexthdr = hdr->nexthdr;
273 int offset;
274
275 /* Check if the value of Router Alert
276 * is for MLD (0x0000).
277 */
278 if ((ptr[2] | ptr[3]) == 0) {
aba6096b
YH
279 deliver = 0;
280
7bc570c8
YH
281 if (!ipv6_ext_hdr(nexthdr)) {
282 /* BUG */
aba6096b 283 goto out;
7bc570c8
YH
284 }
285 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
286 &nexthdr);
287 if (offset < 0)
aba6096b 288 goto out;
7bc570c8
YH
289
290 if (nexthdr != IPPROTO_ICMPV6)
aba6096b 291 goto out;
7bc570c8
YH
292
293 if (!pskb_may_pull(skb, (skb_network_header(skb) +
294 offset + 1 - skb->data)))
aba6096b 295 goto out;
7bc570c8
YH
296
297 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
298
299 switch (icmp6->icmp6_type) {
300 case ICMPV6_MGM_QUERY:
301 case ICMPV6_MGM_REPORT:
302 case ICMPV6_MGM_REDUCTION:
303 case ICMPV6_MLD2_REPORT:
aba6096b 304 deliver = 1;
7bc570c8 305 break;
7bc570c8 306 }
7bc570c8
YH
307 goto out;
308 }
309 /* unknown RA - process it normally */
310 }
1da177e4 311
7bc570c8
YH
312 if (deliver)
313 skb2 = skb_clone(skb, GFP_ATOMIC);
314 else {
315 skb2 = skb;
316 skb = NULL;
317 }
1ab1457c 318
7bc570c8 319 if (skb2) {
7bc570c8 320 ip6_mr_input(skb2);
1da177e4
LT
321 }
322 }
7bc570c8 323out:
aba6096b
YH
324#endif
325 if (likely(deliver))
1da177e4 326 ip6_input(skb);
aba6096b
YH
327 else {
328 /* discard */
329 kfree_skb(skb);
1da177e4 330 }
1da177e4
LT
331
332 return 0;
333}
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