blob: 237e2dba6e944772e27e908188d7531e03744b7d [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * IPv6 input
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +09003 * Linux INET6 implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Ian P. Morris <I.P.Morris@soton.ac.uk>
8 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * 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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/net.h>
27#include <linux/netdevice.h>
28#include <linux/in6.h>
29#include <linux/icmpv6.h>
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +090030#include <linux/mroute6.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
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
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090049inline int ip6_rcv_finish( struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070050{
Eric Dumazetadf30902009-06-02 05:19:30 +000051 if (skb_dst(skb) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 ip6_route_input(skb);
53
54 return dst_input(skb);
55}
56
David S. Millerf2ccd8f2005-08-09 19:34:12 -070057int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058{
59 struct ipv6hdr *hdr;
60 u32 pkt_len;
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090061 struct inet6_dev *idev;
Denis V. Lunev483a47d2008-10-08 11:09:27 -070062 struct net *net = dev_net(skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090064 if (skb->pkt_type == PACKET_OTHERHOST) {
65 kfree_skb(skb);
Mark Smith5c91fac2009-07-06 11:26:24 +000066 return NET_RX_DROP;
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090067 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090069 rcu_read_lock();
70
71 idev = __in6_dev_get(skb->dev);
72
Neil Hormanedf391f2009-04-27 02:45:02 -070073 IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
YOSHIFUJI Hideaki778d80b2008-06-28 14:17:11 +090075 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
76 !idev || unlikely(idev->cnf.disable_ipv6)) {
Denis V. Lunev483a47d2008-10-08 11:09:27 -070077 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
Jesper Nilsson71f6f6d2009-03-27 00:17:45 -070078 goto drop;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 }
80
Guillaume Chazarain6b7fdc32006-07-24 23:44:44 -070081 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
82
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 /*
84 * Store incoming device index. When the packet will
85 * be queued, we cannot refer to skb->dev anymore.
86 *
87 * BTW, when we send a packet for our own local address on a
88 * non-loopback interface (e.g. ethX), it is being delivered
Daniel Lezcanode3cb742007-09-25 19:16:28 -070089 * via the loopback interface (lo) here; skb->dev = loopback_dev.
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 * It, however, should be considered as if it is being
91 * arrived via the sending interface (ethX), because of the
92 * nature of scoping architecture. --yoshfuji
93 */
Eric Dumazetadf30902009-06-02 05:19:30 +000094 IP6CB(skb)->iif = skb_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
Herbert Xu28891392006-06-30 13:35:46 -070096 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 goto err;
98
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -070099 hdr = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
101 if (hdr->version != 6)
102 goto err;
103
YOSHIFUJI Hideakif630e432008-06-19 16:33:57 -0700104 /*
105 * RFC4291 2.5.3
106 * A packet received on an interface with a destination address
107 * of loopback must be dropped.
108 */
109 if (!(dev->flags & IFF_LOOPBACK) &&
110 ipv6_addr_loopback(&hdr->daddr))
111 goto err;
112
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700113 skb->transport_header = skb->network_header + sizeof(*hdr);
Patrick McHardy951dbc82006-01-06 23:02:34 -0800114 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
115
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 pkt_len = ntohs(hdr->payload_len);
117
118 /* pkt_len may be zero if Jumbo payload option is present */
119 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
Mitsuru Chinen60e5c162007-04-04 23:54:59 -0700120 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700121 IP6_INC_STATS_BH(net,
122 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
Mitsuru Chinen60e5c162007-04-04 23:54:59 -0700123 goto drop;
124 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700126 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 goto drop;
128 }
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700129 hdr = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 }
131
132 if (hdr->nexthdr == NEXTHDR_HOP) {
Herbert Xue5bbef22007-10-15 12:50:28 -0700133 if (ipv6_parse_hopopts(skb) < 0) {
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700134 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900135 rcu_read_unlock();
Mark Smith5c91fac2009-07-06 11:26:24 +0000136 return NET_RX_DROP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 }
139
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900140 rcu_read_unlock();
141
Herbert Xu71f9dac2009-06-26 19:22:37 -0700142 /* Must drop socket now because of tproxy. */
143 skb_orphan(skb);
144
Patrick McHardy6e23ae22007-11-19 18:53:30 -0800145 return NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, dev, NULL,
146 ip6_rcv_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147err:
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700148 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149drop:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900150 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 kfree_skb(skb);
Mark Smith5c91fac2009-07-06 11:26:24 +0000152 return NET_RX_DROP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153}
154
155/*
156 * Deliver the packet to the host
157 */
158
159
Patrick McHardyad643a72007-10-15 01:51:38 -0700160static int ip6_input_finish(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161{
Alexey Dobriyan41135cc2009-09-14 12:22:28 +0000162 const struct inet6_protocol *ipprot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 unsigned int nhoff;
Pavel Emelyanov69d6da02007-11-19 22:35:57 -0800164 int nexthdr, raw;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 u8 hash;
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900166 struct inet6_dev *idev;
Eric Dumazetadf30902009-06-02 05:19:30 +0000167 struct net *net = dev_net(skb_dst(skb)->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 /*
170 * Parse extension headers
171 */
172
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 rcu_read_lock();
174resubmit:
Eric Dumazetadf30902009-06-02 05:19:30 +0000175 idev = ip6_dst_idev(skb_dst(skb));
Arnaldo Carvalho de Meloea2ae172007-04-25 17:55:53 -0700176 if (!pskb_pull(skb, skb_transport_offset(skb)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 goto discard;
Patrick McHardy951dbc82006-01-06 23:02:34 -0800178 nhoff = IP6CB(skb)->nhoff;
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700179 nexthdr = skb_network_header(skb)[nhoff];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
Pavel Emelyanov69d6da02007-11-19 22:35:57 -0800181 raw = raw6_local_deliver(skb, nexthdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183 hash = nexthdr & (MAX_INET_PROTOS - 1);
184 if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
185 int ret;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 if (ipprot->flags & INET6_PROTO_FINAL) {
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900188 struct ipv6hdr *hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
Yasuyuki Kozakai9fb9cbb2005-11-09 16:38:16 -0800190 /* Free reference early: we don't need it any more,
191 and it may hold ip_conntrack module loaded
192 indefinitely. */
193 nf_reset(skb);
194
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700195 skb_postpull_rcsum(skb, skb_network_header(skb),
Arnaldo Carvalho de Melocfe1fc72007-03-16 17:26:39 -0300196 skb_network_header_len(skb));
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700197 hdr = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 if (ipv6_addr_is_multicast(&hdr->daddr) &&
199 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
200 &hdr->saddr) &&
201 !ipv6_is_mld(skb, nexthdr))
202 goto discard;
203 }
204 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900205 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 goto discard;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900207
Herbert Xue5bbef22007-10-15 12:50:28 -0700208 ret = ipprot->handler(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 if (ret > 0)
210 goto resubmit;
211 else if (ret == 0)
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700212 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 } else {
Pavel Emelyanov69d6da02007-11-19 22:35:57 -0800214 if (!raw) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700216 IP6_INC_STATS_BH(net, idev,
217 IPSTATS_MIB_INUNKNOWNPROTOS);
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700218 icmpv6_send(skb, ICMPV6_PARAMPROB,
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900219 ICMPV6_UNK_NEXTHDR, nhoff,
220 skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 }
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700222 } else
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700223 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700224 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 }
226 rcu_read_unlock();
227 return 0;
228
229discard:
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700230 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 rcu_read_unlock();
232 kfree_skb(skb);
233 return 0;
234}
235
236
237int ip6_input(struct sk_buff *skb)
238{
Patrick McHardy6e23ae22007-11-19 18:53:30 -0800239 return NF_HOOK(PF_INET6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
240 ip6_input_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241}
242
243int ip6_mc_input(struct sk_buff *skb)
244{
245 struct ipv6hdr *hdr;
246 int deliver;
247
Eric Dumazetadf30902009-06-02 05:19:30 +0000248 IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev),
249 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
Neil Hormanedf391f2009-04-27 02:45:02 -0700250 skb->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700252 hdr = ipv6_hdr(skb);
YOSHIFUJI Hideaki4c7966b2008-03-31 19:30:45 -0700253 deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900255#ifdef CONFIG_IPV6_MROUTE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 /*
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900257 * IPv6 multicast router mode is now supported ;)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 */
YOSHIFUJI Hideaki53b79972008-07-19 22:35:03 -0700259 if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
Thomas Goff1d6e55f2009-01-27 22:39:59 -0800260 !(ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) &&
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900261 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900269 /* 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900277 /* Check if the value of Router Alert
278 * is for MLD (0x0000).
279 */
280 if ((ptr[2] | ptr[3]) == 0) {
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900281 deliver = 0;
282
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900283 if (!ipv6_ext_hdr(nexthdr)) {
284 /* BUG */
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900285 goto out;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900286 }
287 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
288 &nexthdr);
289 if (offset < 0)
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900290 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900292 if (nexthdr != IPPROTO_ICMPV6)
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900293 goto out;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900294
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900295 if (!pskb_may_pull(skb, (skb_network_header(skb) +
296 offset + 1 - skb->data)))
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900297 goto out;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900298
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:
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900306 deliver = 1;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900307 break;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900308 }
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900309 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 }
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900311 /* 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) {
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900322 ip6_mr_input(skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 }
324 }
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900325out:
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900326#endif
327 if (likely(deliver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 ip6_input(skb);
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900329 else {
330 /* discard */
331 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333
334 return 0;
335}