blob: 4e5c8615832c61d88034910422db16722151de05 [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 *
9 * $Id: ip6_input.c,v 1.19 2000/12/13 18:31:50 davem Exp $
10 *
11 * Based in linux/net/ipv4/ip_input.c
12 *
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
17 */
18/* Changes
19 *
20 * Mitsuru KANDA @USAGI and
21 * YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
22 */
23
24#include <linux/errno.h>
25#include <linux/types.h>
26#include <linux/socket.h>
27#include <linux/sockios.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/net.h>
29#include <linux/netdevice.h>
30#include <linux/in6.h>
31#include <linux/icmpv6.h>
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +090032#include <linux/mroute6.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34#include <linux/netfilter.h>
35#include <linux/netfilter_ipv6.h>
36
37#include <net/sock.h>
38#include <net/snmp.h>
39
40#include <net/ipv6.h>
41#include <net/protocol.h>
42#include <net/transp_v6.h>
43#include <net/rawv6.h>
44#include <net/ndisc.h>
45#include <net/ip6_route.h>
46#include <net/addrconf.h>
47#include <net/xfrm.h>
48
49
50
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090051inline int ip6_rcv_finish( struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052{
53 if (skb->dst == NULL)
54 ip6_route_input(skb);
55
56 return dst_input(skb);
57}
58
David S. Millerf2ccd8f2005-08-09 19:34:12 -070059int 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 -070060{
61 struct ipv6hdr *hdr;
62 u32 pkt_len;
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090063 struct inet6_dev *idev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090065 if (skb->pkt_type == PACKET_OTHERHOST) {
66 kfree_skb(skb);
67 return 0;
68 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090070 rcu_read_lock();
71
72 idev = __in6_dev_get(skb->dev);
73
74 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INRECEIVES);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090077 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
78 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 goto out;
80 }
81
Guillaume Chazarain6b7fdc32006-07-24 23:44:44 -070082 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
83
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 /*
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
Daniel Lezcanode3cb742007-09-25 19:16:28 -070090 * via the loopback interface (lo) here; skb->dev = loopback_dev.
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 * 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 */
YOSHIFUJI Hideaki7a3025b2006-10-13 16:17:25 +090095 IP6CB(skb)->iif = skb->dst ? ip6_dst_idev(skb->dst)->dev->ifindex : dev->ifindex;
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
Herbert Xu28891392006-06-30 13:35:46 -070097 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 goto err;
99
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700100 hdr = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
102 if (hdr->version != 6)
103 goto err;
104
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700105 skb->transport_header = skb->network_header + sizeof(*hdr);
Patrick McHardy951dbc82006-01-06 23:02:34 -0800106 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
107
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 pkt_len = ntohs(hdr->payload_len);
109
110 /* pkt_len may be zero if Jumbo payload option is present */
111 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
Mitsuru Chinen60e5c162007-04-04 23:54:59 -0700112 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
113 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INTRUNCATEDPKTS);
114 goto drop;
115 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900117 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 goto drop;
119 }
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700120 hdr = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 }
122
123 if (hdr->nexthdr == NEXTHDR_HOP) {
Herbert Xue5bbef22007-10-15 12:50:28 -0700124 if (ipv6_parse_hopopts(skb) < 0) {
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900125 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
126 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 return 0;
128 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 }
130
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900131 rcu_read_unlock();
132
Patrick McHardy6e23ae22007-11-19 18:53:30 -0800133 return NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, dev, NULL,
134 ip6_rcv_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135err:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900136 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137drop:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900138 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 kfree_skb(skb);
140out:
141 return 0;
142}
143
144/*
145 * Deliver the packet to the host
146 */
147
148
Patrick McHardyad643a72007-10-15 01:51:38 -0700149static int ip6_input_finish(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150{
151 struct inet6_protocol *ipprot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 unsigned int nhoff;
Pavel Emelyanov69d6da02007-11-19 22:35:57 -0800153 int nexthdr, raw;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 u8 hash;
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900155 struct inet6_dev *idev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 /*
158 * Parse extension headers
159 */
160
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 rcu_read_lock();
162resubmit:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900163 idev = ip6_dst_idev(skb->dst);
Arnaldo Carvalho de Meloea2ae172007-04-25 17:55:53 -0700164 if (!pskb_pull(skb, skb_transport_offset(skb)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 goto discard;
Patrick McHardy951dbc82006-01-06 23:02:34 -0800166 nhoff = IP6CB(skb)->nhoff;
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700167 nexthdr = skb_network_header(skb)[nhoff];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
Pavel Emelyanov69d6da02007-11-19 22:35:57 -0800169 raw = raw6_local_deliver(skb, nexthdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
171 hash = nexthdr & (MAX_INET_PROTOS - 1);
172 if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
173 int ret;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 if (ipprot->flags & INET6_PROTO_FINAL) {
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900176 struct ipv6hdr *hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
Yasuyuki Kozakai9fb9cbb2005-11-09 16:38:16 -0800178 /* Free reference early: we don't need it any more,
179 and it may hold ip_conntrack module loaded
180 indefinitely. */
181 nf_reset(skb);
182
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700183 skb_postpull_rcsum(skb, skb_network_header(skb),
Arnaldo Carvalho de Melocfe1fc72007-03-16 17:26:39 -0300184 skb_network_header_len(skb));
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700185 hdr = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 if (ipv6_addr_is_multicast(&hdr->daddr) &&
187 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
188 &hdr->saddr) &&
189 !ipv6_is_mld(skb, nexthdr))
190 goto discard;
191 }
192 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900193 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 goto discard;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900195
Herbert Xue5bbef22007-10-15 12:50:28 -0700196 ret = ipprot->handler(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 if (ret > 0)
198 goto resubmit;
199 else if (ret == 0)
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900200 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 } else {
Pavel Emelyanov69d6da02007-11-19 22:35:57 -0800202 if (!raw) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900204 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INUNKNOWNPROTOS);
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700205 icmpv6_send(skb, ICMPV6_PARAMPROB,
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900206 ICMPV6_UNK_NEXTHDR, nhoff,
207 skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 }
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700209 } else
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900210 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700211 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 }
213 rcu_read_unlock();
214 return 0;
215
216discard:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900217 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 rcu_read_unlock();
219 kfree_skb(skb);
220 return 0;
221}
222
223
224int ip6_input(struct sk_buff *skb)
225{
Patrick McHardy6e23ae22007-11-19 18:53:30 -0800226 return NF_HOOK(PF_INET6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
227 ip6_input_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228}
229
230int ip6_mc_input(struct sk_buff *skb)
231{
232 struct ipv6hdr *hdr;
233 int deliver;
234
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900235 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700237 hdr = ipv6_hdr(skb);
YOSHIFUJI Hideaki4c7966b2008-03-31 19:30:45 -0700238 deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900240#ifdef CONFIG_IPV6_MROUTE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 /*
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900242 * IPv6 multicast router mode is now supported ;)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 */
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900244 if (ipv6_devconf.mc_forwarding &&
245 likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
246 /*
247 * Okay, we try to forward - split and duplicate
248 * packets.
249 */
250 struct sk_buff *skb2;
251 struct inet6_skb_parm *opt = IP6CB(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900253 /* Check for MLD */
254 if (unlikely(opt->ra)) {
255 /* Check if this is a mld message */
256 u8 *ptr = skb_network_header(skb) + opt->ra;
257 struct icmp6hdr *icmp6;
258 u8 nexthdr = hdr->nexthdr;
259 int offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900261 /* Check if the value of Router Alert
262 * is for MLD (0x0000).
263 */
264 if ((ptr[2] | ptr[3]) == 0) {
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900265 deliver = 0;
266
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900267 if (!ipv6_ext_hdr(nexthdr)) {
268 /* BUG */
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900269 goto out;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900270 }
271 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
272 &nexthdr);
273 if (offset < 0)
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900274 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900276 if (nexthdr != IPPROTO_ICMPV6)
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900277 goto out;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900278
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900279 if (!pskb_may_pull(skb, (skb_network_header(skb) +
280 offset + 1 - skb->data)))
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900281 goto out;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900282
283 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
284
285 switch (icmp6->icmp6_type) {
286 case ICMPV6_MGM_QUERY:
287 case ICMPV6_MGM_REPORT:
288 case ICMPV6_MGM_REDUCTION:
289 case ICMPV6_MLD2_REPORT:
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900290 deliver = 1;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900291 break;
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900292 }
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900293 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 }
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900295 /* unknown RA - process it normally */
296 }
297
298 if (deliver)
299 skb2 = skb_clone(skb, GFP_ATOMIC);
300 else {
301 skb2 = skb;
302 skb = NULL;
303 }
304
305 if (skb2) {
306 skb2->dev = skb2->dst->dev;
307 ip6_mr_input(skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 }
309 }
YOSHIFUJI Hideaki7bc570c2008-04-03 09:22:53 +0900310out:
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900311#endif
312 if (likely(deliver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 ip6_input(skb);
YOSHIFUJI Hideakiaba60962008-04-10 15:41:26 +0900314 else {
315 /* discard */
316 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318
319 return 0;
320}