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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * IPv6 input
3 * Linux INET6 implementation
4 *
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>
28#include <linux/sched.h>
29#include <linux/net.h>
30#include <linux/netdevice.h>
31#include <linux/in6.h>
32#include <linux/icmpv6.h>
33
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
Patrick McHardyb05e1062006-01-06 23:03:34 -080051inline 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
90 * via the loopback interface (lo) here; skb->dev = &loopback_dev.
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 */
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 hdr = skb->nh.ipv6h;
101
102 if (hdr->version != 6)
103 goto err;
104
Patrick McHardy951dbc82006-01-06 23:02:34 -0800105 skb->h.raw = (u8 *)(hdr + 1);
106 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) {
112 if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
113 goto truncated;
114 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900115 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 goto drop;
117 }
118 hdr = skb->nh.ipv6h;
119 }
120
121 if (hdr->nexthdr == NEXTHDR_HOP) {
Masahide NAKAMURAa80ff032006-08-23 19:19:50 -0700122 if (ipv6_parse_hopopts(&skb) < 0) {
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900123 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
124 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 return 0;
126 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 }
128
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900129 rcu_read_unlock();
130
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 return NF_HOOK(PF_INET6,NF_IP6_PRE_ROUTING, skb, dev, NULL, ip6_rcv_finish);
132truncated:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900133 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INTRUNCATEDPKTS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134err:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900135 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136drop:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900137 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 kfree_skb(skb);
139out:
140 return 0;
141}
142
143/*
144 * Deliver the packet to the host
145 */
146
147
148static inline int ip6_input_finish(struct sk_buff *skb)
149{
150 struct inet6_protocol *ipprot;
151 struct sock *raw_sk;
152 unsigned int nhoff;
153 int nexthdr;
154 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 if (!pskb_pull(skb, skb->h.raw - skb->data))
165 goto discard;
Patrick McHardy951dbc82006-01-06 23:02:34 -0800166 nhoff = IP6CB(skb)->nhoff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 nexthdr = skb->nh.raw[nhoff];
168
169 raw_sk = sk_head(&raw_v6_htable[nexthdr & (MAX_INET_PROTOS - 1)]);
Patrick McHardyd13964f2005-08-09 19:45:02 -0700170 if (raw_sk && !ipv6_raw_deliver(skb, nexthdr))
171 raw_sk = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
173 hash = nexthdr & (MAX_INET_PROTOS - 1);
174 if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
175 int ret;
176
177 if (ipprot->flags & INET6_PROTO_FINAL) {
178 struct ipv6hdr *hdr;
179
Yasuyuki Kozakai9fb9cbb2005-11-09 16:38:16 -0800180 /* Free reference early: we don't need it any more,
181 and it may hold ip_conntrack module loaded
182 indefinitely. */
183 nf_reset(skb);
184
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 skb_postpull_rcsum(skb, skb->nh.raw,
186 skb->h.raw - skb->nh.raw);
187 hdr = skb->nh.ipv6h;
188 if (ipv6_addr_is_multicast(&hdr->daddr) &&
189 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
190 &hdr->saddr) &&
191 !ipv6_is_mld(skb, nexthdr))
192 goto discard;
193 }
194 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
195 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
196 goto discard;
197
Patrick McHardy951dbc82006-01-06 23:02:34 -0800198 ret = ipprot->handler(&skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 if (ret > 0)
200 goto resubmit;
201 else if (ret == 0)
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900202 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 } else {
204 if (!raw_sk) {
205 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900206 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INUNKNOWNPROTOS);
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700207 icmpv6_send(skb, ICMPV6_PARAMPROB,
208 ICMPV6_UNK_NEXTHDR, nhoff,
209 skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 }
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700211 } else
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900212 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700213 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 }
215 rcu_read_unlock();
216 return 0;
217
218discard:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900219 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 rcu_read_unlock();
221 kfree_skb(skb);
222 return 0;
223}
224
225
226int ip6_input(struct sk_buff *skb)
227{
228 return NF_HOOK(PF_INET6,NF_IP6_LOCAL_IN, skb, skb->dev, NULL, ip6_input_finish);
229}
230
231int ip6_mc_input(struct sk_buff *skb)
232{
233 struct ipv6hdr *hdr;
234 int deliver;
235
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900236 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
238 hdr = skb->nh.ipv6h;
239 deliver = likely(!(skb->dev->flags & (IFF_PROMISC|IFF_ALLMULTI))) ||
240 ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
241
242 /*
243 * IPv6 multicast router mode isnt currently supported.
244 */
245#if 0
246 if (ipv6_config.multicast_route) {
247 int addr_type;
248
249 addr_type = ipv6_addr_type(&hdr->daddr);
250
251 if (!(addr_type & (IPV6_ADDR_LOOPBACK | IPV6_ADDR_LINKLOCAL))) {
252 struct sk_buff *skb2;
253 struct dst_entry *dst;
254
255 dst = skb->dst;
256
257 if (deliver) {
258 skb2 = skb_clone(skb, GFP_ATOMIC);
259 dst_output(skb2);
260 } else {
261 dst_output(skb);
262 return 0;
263 }
264 }
265 }
266#endif
267
268 if (likely(deliver)) {
269 ip6_input(skb);
270 return 0;
271 }
272 /* discard */
273 kfree_skb(skb);
274
275 return 0;
276}