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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>
32
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
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090050inline int ip6_rcv_finish( struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070051{
52 if (skb->dst == NULL)
53 ip6_route_input(skb);
54
55 return dst_input(skb);
56}
57
David S. Millerf2ccd8f2005-08-09 19:34:12 -070058int 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 -070059{
60 struct ipv6hdr *hdr;
61 u32 pkt_len;
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090062 struct inet6_dev *idev;
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);
66 return 0;
67 }
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
73 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INRECEIVES);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +090076 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
77 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 goto out;
79 }
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
89 * via the loopback interface (lo) here; skb->dev = &loopback_dev.
90 * 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 */
YOSHIFUJI Hideaki7a3025b2006-10-13 16:17:25 +090094 IP6CB(skb)->iif = skb->dst ? ip6_dst_idev(skb->dst)->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
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700104 skb->transport_header = skb->network_header + sizeof(*hdr);
Patrick McHardy951dbc82006-01-06 23:02:34 -0800105 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
106
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 pkt_len = ntohs(hdr->payload_len);
108
109 /* pkt_len may be zero if Jumbo payload option is present */
110 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
Mitsuru Chinen60e5c162007-04-04 23:54:59 -0700111 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
112 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INTRUNCATEDPKTS);
113 goto drop;
114 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900116 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 goto drop;
118 }
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700119 hdr = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 }
121
122 if (hdr->nexthdr == NEXTHDR_HOP) {
Masahide NAKAMURAa80ff032006-08-23 19:19:50 -0700123 if (ipv6_parse_hopopts(&skb) < 0) {
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900124 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
125 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 return 0;
127 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 }
129
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900130 rcu_read_unlock();
131
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 return NF_HOOK(PF_INET6,NF_IP6_PRE_ROUTING, skb, dev, NULL, ip6_rcv_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133err:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900134 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135drop:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900136 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 kfree_skb(skb);
138out:
139 return 0;
140}
141
142/*
143 * Deliver the packet to the host
144 */
145
146
147static inline int ip6_input_finish(struct sk_buff *skb)
148{
149 struct inet6_protocol *ipprot;
150 struct sock *raw_sk;
151 unsigned int nhoff;
152 int nexthdr;
153 u8 hash;
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900154 struct inet6_dev *idev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 /*
157 * Parse extension headers
158 */
159
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 rcu_read_lock();
161resubmit:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900162 idev = ip6_dst_idev(skb->dst);
Arnaldo Carvalho de Meloea2ae172007-04-25 17:55:53 -0700163 if (!pskb_pull(skb, skb_transport_offset(skb)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 goto discard;
Patrick McHardy951dbc82006-01-06 23:02:34 -0800165 nhoff = IP6CB(skb)->nhoff;
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700166 nexthdr = skb_network_header(skb)[nhoff];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
168 raw_sk = sk_head(&raw_v6_htable[nexthdr & (MAX_INET_PROTOS - 1)]);
Patrick McHardyd13964f2005-08-09 19:45:02 -0700169 if (raw_sk && !ipv6_raw_deliver(skb, nexthdr))
170 raw_sk = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
172 hash = nexthdr & (MAX_INET_PROTOS - 1);
173 if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
174 int ret;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900175
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 if (ipprot->flags & INET6_PROTO_FINAL) {
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900177 struct ipv6hdr *hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178
Yasuyuki Kozakai9fb9cbb2005-11-09 16:38:16 -0800179 /* Free reference early: we don't need it any more,
180 and it may hold ip_conntrack module loaded
181 indefinitely. */
182 nf_reset(skb);
183
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700184 skb_postpull_rcsum(skb, skb_network_header(skb),
Arnaldo Carvalho de Melocfe1fc72007-03-16 17:26:39 -0300185 skb_network_header_len(skb));
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700186 hdr = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 if (ipv6_addr_is_multicast(&hdr->daddr) &&
188 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
189 &hdr->saddr) &&
190 !ipv6_is_mld(skb, nexthdr))
191 goto discard;
192 }
193 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900194 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 goto discard;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900196
Patrick McHardy951dbc82006-01-06 23:02:34 -0800197 ret = ipprot->handler(&skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 if (ret > 0)
199 goto resubmit;
200 else if (ret == 0)
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900201 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 } else {
203 if (!raw_sk) {
204 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900205 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INUNKNOWNPROTOS);
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700206 icmpv6_send(skb, ICMPV6_PARAMPROB,
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900207 ICMPV6_UNK_NEXTHDR, nhoff,
208 skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 }
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700210 } else
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900211 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700212 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 }
214 rcu_read_unlock();
215 return 0;
216
217discard:
YOSHIFUJI Hideakia11d2062006-11-04 20:11:37 +0900218 IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 rcu_read_unlock();
220 kfree_skb(skb);
221 return 0;
222}
223
224
225int ip6_input(struct sk_buff *skb)
226{
227 return NF_HOOK(PF_INET6,NF_IP6_LOCAL_IN, skb, skb->dev, NULL, ip6_input_finish);
228}
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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 deliver = likely(!(skb->dev->flags & (IFF_PROMISC|IFF_ALLMULTI))) ||
239 ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
240
241 /*
242 * IPv6 multicast router mode isnt currently supported.
243 */
244#if 0
245 if (ipv6_config.multicast_route) {
246 int addr_type;
247
248 addr_type = ipv6_addr_type(&hdr->daddr);
249
250 if (!(addr_type & (IPV6_ADDR_LOOPBACK | IPV6_ADDR_LINKLOCAL))) {
251 struct sk_buff *skb2;
252 struct dst_entry *dst;
253
254 dst = skb->dst;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900255
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 if (deliver) {
257 skb2 = skb_clone(skb, GFP_ATOMIC);
258 dst_output(skb2);
259 } else {
260 dst_output(skb);
261 return 0;
262 }
263 }
264 }
265#endif
266
267 if (likely(deliver)) {
268 ip6_input(skb);
269 return 0;
270 }
271 /* discard */
272 kfree_skb(skb);
273
274 return 0;
275}