blob: a52d864d562b4067e8f70db9e0fabbafe76b7fea [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090031#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
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
Eric Dumazetc7109982012-07-26 12:18:11 +000050int ip6_rcv_finish(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070051{
Eric Dumazetc7109982012-07-26 12:18:11 +000052 if (sysctl_ip_early_demux && !skb_dst(skb)) {
53 const struct inet6_protocol *ipprot;
54
Eric Dumazetc7109982012-07-26 12:18:11 +000055 ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
56 if (ipprot && ipprot->early_demux)
57 ipprot->early_demux(skb);
Eric Dumazetc7109982012-07-26 12:18:11 +000058 }
59 if (!skb_dst(skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 ip6_route_input(skb);
61
62 return dst_input(skb);
63}
64
David S. Millerf2ccd8f2005-08-09 19:34:12 -070065int 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 -070066{
Eric Dumazetb71d1d42011-04-22 04:53:02 +000067 const struct ipv6hdr *hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 u32 pkt_len;
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090069 struct inet6_dev *idev;
Denis V. Lunev483a47d2008-10-08 11:09:27 -070070 struct net *net = dev_net(skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090072 if (skb->pkt_type == PACKET_OTHERHOST) {
73 kfree_skb(skb);
Mark Smith5c91fac2009-07-06 11:26:24 +000074 return NET_RX_DROP;
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090075 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090077 rcu_read_lock();
78
79 idev = __in6_dev_get(skb->dev);
80
Neil Hormanedf391f2009-04-27 02:45:02 -070081 IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
YOSHIFUJI Hideaki778d80b2008-06-28 14:17:11 +090083 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
84 !idev || unlikely(idev->cnf.disable_ipv6)) {
Denis V. Lunev483a47d2008-10-08 11:09:27 -070085 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
Jesper Nilsson71f6f6d2009-03-27 00:17:45 -070086 goto drop;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 }
88
Guillaume Chazarain6b7fdc32006-07-24 23:44:44 -070089 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
90
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 /*
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
Daniel Lezcanode3cb742007-09-25 19:16:28 -070097 * via the loopback interface (lo) here; skb->dev = loopback_dev.
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 * 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 */
Eric Dumazetadf30902009-06-02 05:19:30 +0000102 IP6CB(skb)->iif = skb_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Herbert Xu28891392006-06-30 13:35:46 -0700104 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 goto err;
106
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700107 hdr = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
109 if (hdr->version != 6)
110 goto err;
111
YOSHIFUJI Hideakif630e432008-06-19 16:33:57 -0700112 /*
113 * RFC4291 2.5.3
114 * A packet received on an interface with a destination address
115 * of loopback must be dropped.
116 */
117 if (!(dev->flags & IFF_LOOPBACK) &&
118 ipv6_addr_loopback(&hdr->daddr))
119 goto err;
120
Brian Haleyc4573382011-11-08 04:41:42 +0000121 /*
122 * RFC4291 2.7
123 * Multicast addresses must not be used as source addresses in IPv6
124 * packets or appear in any Routing header.
125 */
126 if (ipv6_addr_is_multicast(&hdr->saddr))
127 goto err;
128
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700129 skb->transport_header = skb->network_header + sizeof(*hdr);
Patrick McHardy951dbc82006-01-06 23:02:34 -0800130 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
131
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 pkt_len = ntohs(hdr->payload_len);
133
134 /* pkt_len may be zero if Jumbo payload option is present */
135 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
Mitsuru Chinen60e5c162007-04-04 23:54:59 -0700136 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700137 IP6_INC_STATS_BH(net,
138 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
Mitsuru Chinen60e5c162007-04-04 23:54:59 -0700139 goto drop;
140 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700142 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 goto drop;
144 }
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700145 hdr = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 }
147
148 if (hdr->nexthdr == NEXTHDR_HOP) {
Herbert Xue5bbef22007-10-15 12:50:28 -0700149 if (ipv6_parse_hopopts(skb) < 0) {
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700150 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900151 rcu_read_unlock();
Mark Smith5c91fac2009-07-06 11:26:24 +0000152 return NET_RX_DROP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 }
155
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900156 rcu_read_unlock();
157
Herbert Xu71f9dac2009-06-26 19:22:37 -0700158 /* Must drop socket now because of tproxy. */
159 skb_orphan(skb);
160
Jan Engelhardtb2e0b382010-03-23 04:09:07 +0100161 return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, dev, NULL,
Patrick McHardy6e23ae22007-11-19 18:53:30 -0800162 ip6_rcv_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163err:
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700164 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165drop:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900166 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 kfree_skb(skb);
Mark Smith5c91fac2009-07-06 11:26:24 +0000168 return NET_RX_DROP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169}
170
171/*
172 * Deliver the packet to the host
173 */
174
175
Patrick McHardyad643a72007-10-15 01:51:38 -0700176static int ip6_input_finish(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177{
David S. Millerf9242b62012-06-19 18:56:21 -0700178 struct net *net = dev_net(skb_dst(skb)->dev);
Alexey Dobriyan41135cc2009-09-14 12:22:28 +0000179 const struct inet6_protocol *ipprot;
David S. Millerf9242b62012-06-19 18:56:21 -0700180 struct inet6_dev *idev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 unsigned int nhoff;
Eric Dumazeta50feda2012-05-18 18:57:34 +0000182 int nexthdr;
183 bool raw;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 /*
186 * Parse extension headers
187 */
188
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 rcu_read_lock();
190resubmit:
Eric Dumazetadf30902009-06-02 05:19:30 +0000191 idev = ip6_dst_idev(skb_dst(skb));
Arnaldo Carvalho de Meloea2ae172007-04-25 17:55:53 -0700192 if (!pskb_pull(skb, skb_transport_offset(skb)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 goto discard;
Patrick McHardy951dbc82006-01-06 23:02:34 -0800194 nhoff = IP6CB(skb)->nhoff;
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700195 nexthdr = skb_network_header(skb)[nhoff];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
Pavel Emelyanov69d6da02007-11-19 22:35:57 -0800197 raw = raw6_local_deliver(skb, nexthdr);
David S. Millerf9242b62012-06-19 18:56:21 -0700198 if ((ipprot = rcu_dereference(inet6_protos[nexthdr])) != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 int ret;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900200
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 if (ipprot->flags & INET6_PROTO_FINAL) {
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000202 const struct ipv6hdr *hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
Yasuyuki Kozakai9fb9cbb2005-11-09 16:38:16 -0800204 /* Free reference early: we don't need it any more,
205 and it may hold ip_conntrack module loaded
206 indefinitely. */
207 nf_reset(skb);
208
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700209 skb_postpull_rcsum(skb, skb_network_header(skb),
Arnaldo Carvalho de Melocfe1fc72007-03-16 17:26:39 -0300210 skb_network_header_len(skb));
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700211 hdr = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 if (ipv6_addr_is_multicast(&hdr->daddr) &&
213 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
214 &hdr->saddr) &&
215 !ipv6_is_mld(skb, nexthdr))
216 goto discard;
217 }
218 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900219 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 goto discard;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900221
Herbert Xue5bbef22007-10-15 12:50:28 -0700222 ret = ipprot->handler(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 if (ret > 0)
224 goto resubmit;
225 else if (ret == 0)
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700226 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 } else {
Pavel Emelyanov69d6da02007-11-19 22:35:57 -0800228 if (!raw) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700230 IP6_INC_STATS_BH(net, idev,
231 IPSTATS_MIB_INUNKNOWNPROTOS);
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700232 icmpv6_send(skb, ICMPV6_PARAMPROB,
Alexey Dobriyan3ffe5332010-02-18 08:25:24 +0000233 ICMPV6_UNK_NEXTHDR, nhoff);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 }
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700235 } else
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700236 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700237 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 }
239 rcu_read_unlock();
240 return 0;
241
242discard:
Denis V. Lunev483a47d2008-10-08 11:09:27 -0700243 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 rcu_read_unlock();
245 kfree_skb(skb);
246 return 0;
247}
248
249
250int ip6_input(struct sk_buff *skb)
251{
Jan Engelhardtb2e0b382010-03-23 04:09:07 +0100252 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
Patrick McHardy6e23ae22007-11-19 18:53:30 -0800253 ip6_input_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254}
255
256int ip6_mc_input(struct sk_buff *skb)
257{
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000258 const struct ipv6hdr *hdr;
Eric Dumazeta50feda2012-05-18 18:57:34 +0000259 bool deliver;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
Eric Dumazetadf30902009-06-02 05:19:30 +0000261 IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev),
262 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
Neil Hormanedf391f2009-04-27 02:45:02 -0700263 skb->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700265 hdr = ipv6_hdr(skb);
YOSHIFUJI Hideaki4c7966b2008-03-31 19:30:45 -0700266 deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900268#ifdef CONFIG_IPV6_MROUTE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 /*
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900270 * IPv6 multicast router mode is now supported ;)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 */
YOSHIFUJI Hideaki53b79972008-07-19 22:35:03 -0700272 if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
Thomas Goff1d6e55f2009-01-27 22:39:59 -0800273 !(ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) &&
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900274 likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
275 /*
276 * Okay, we try to forward - split and duplicate
277 * packets.
278 */
279 struct sk_buff *skb2;
280 struct inet6_skb_parm *opt = IP6CB(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900282 /* Check for MLD */
283 if (unlikely(opt->ra)) {
284 /* Check if this is a mld message */
285 u8 *ptr = skb_network_header(skb) + opt->ra;
286 struct icmp6hdr *icmp6;
287 u8 nexthdr = hdr->nexthdr;
Jesse Gross75f28112011-11-30 17:05:51 -0800288 __be16 frag_off;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900289 int offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900291 /* Check if the value of Router Alert
292 * is for MLD (0x0000).
293 */
294 if ((ptr[2] | ptr[3]) == 0) {
Eric Dumazeta50feda2012-05-18 18:57:34 +0000295 deliver = false;
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900296
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900297 if (!ipv6_ext_hdr(nexthdr)) {
298 /* BUG */
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900299 goto out;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900300 }
301 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
Jesse Gross75f28112011-11-30 17:05:51 -0800302 &nexthdr, &frag_off);
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900303 if (offset < 0)
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900304 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900306 if (nexthdr != IPPROTO_ICMPV6)
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900307 goto out;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900308
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900309 if (!pskb_may_pull(skb, (skb_network_header(skb) +
310 offset + 1 - skb->data)))
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900311 goto out;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900312
313 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
314
315 switch (icmp6->icmp6_type) {
316 case ICMPV6_MGM_QUERY:
317 case ICMPV6_MGM_REPORT:
318 case ICMPV6_MGM_REDUCTION:
319 case ICMPV6_MLD2_REPORT:
Eric Dumazeta50feda2012-05-18 18:57:34 +0000320 deliver = true;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900321 break;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900322 }
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900323 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 }
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900325 /* unknown RA - process it normally */
326 }
327
328 if (deliver)
329 skb2 = skb_clone(skb, GFP_ATOMIC);
330 else {
331 skb2 = skb;
332 skb = NULL;
333 }
334
335 if (skb2) {
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900336 ip6_mr_input(skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 }
338 }
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900339out:
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900340#endif
341 if (likely(deliver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 ip6_input(skb);
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900343 else {
344 /* discard */
345 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347
348 return 0;
349}