blob: a6026d2787d2c042a05924c33ebba66f91b6f101 [file] [log] [blame]
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
51static inline int ip6_rcv_finish( struct sk_buff *skb)
52{
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;
63
64 if (skb->pkt_type == PACKET_OTHERHOST)
65 goto drop;
66
67 IP6_INC_STATS_BH(IPSTATS_MIB_INRECEIVES);
68
69 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
70 IP6_INC_STATS_BH(IPSTATS_MIB_INDISCARDS);
71 goto out;
72 }
73
74 /*
75 * Store incoming device index. When the packet will
76 * be queued, we cannot refer to skb->dev anymore.
77 *
78 * BTW, when we send a packet for our own local address on a
79 * non-loopback interface (e.g. ethX), it is being delivered
80 * via the loopback interface (lo) here; skb->dev = &loopback_dev.
81 * It, however, should be considered as if it is being
82 * arrived via the sending interface (ethX), because of the
83 * nature of scoping architecture. --yoshfuji
84 */
85 IP6CB(skb)->iif = skb->dst ? ((struct rt6_info *)skb->dst)->rt6i_idev->dev->ifindex : dev->ifindex;
86
87 if (skb->len < sizeof(struct ipv6hdr))
88 goto err;
89
90 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) {
91 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
92 goto drop;
93 }
94
95 hdr = skb->nh.ipv6h;
96
97 if (hdr->version != 6)
98 goto err;
99
100 pkt_len = ntohs(hdr->payload_len);
101
102 /* pkt_len may be zero if Jumbo payload option is present */
103 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
104 if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
105 goto truncated;
106 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
107 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
108 goto drop;
109 }
110 hdr = skb->nh.ipv6h;
111 }
112
113 if (hdr->nexthdr == NEXTHDR_HOP) {
114 skb->h.raw = (u8*)(hdr+1);
115 if (ipv6_parse_hopopts(skb, offsetof(struct ipv6hdr, nexthdr)) < 0) {
116 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
117 return 0;
118 }
119 hdr = skb->nh.ipv6h;
120 }
121
122 return NF_HOOK(PF_INET6,NF_IP6_PRE_ROUTING, skb, dev, NULL, ip6_rcv_finish);
123truncated:
124 IP6_INC_STATS_BH(IPSTATS_MIB_INTRUNCATEDPKTS);
125err:
126 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
127drop:
128 kfree_skb(skb);
129out:
130 return 0;
131}
132
133/*
134 * Deliver the packet to the host
135 */
136
137
138static inline int ip6_input_finish(struct sk_buff *skb)
139{
140 struct inet6_protocol *ipprot;
141 struct sock *raw_sk;
142 unsigned int nhoff;
143 int nexthdr;
144 u8 hash;
145
146 skb->h.raw = skb->nh.raw + sizeof(struct ipv6hdr);
147
148 /*
149 * Parse extension headers
150 */
151
152 nexthdr = skb->nh.ipv6h->nexthdr;
153 nhoff = offsetof(struct ipv6hdr, nexthdr);
154
155 /* Skip hop-by-hop options, they are already parsed. */
156 if (nexthdr == NEXTHDR_HOP) {
157 nhoff = sizeof(struct ipv6hdr);
158 nexthdr = skb->h.raw[0];
159 skb->h.raw += (skb->h.raw[1]+1)<<3;
160 }
161
162 rcu_read_lock();
163resubmit:
164 if (!pskb_pull(skb, skb->h.raw - skb->data))
165 goto discard;
166 nexthdr = skb->nh.raw[nhoff];
167
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;
175
176 if (ipprot->flags & INET6_PROTO_FINAL) {
177 struct ipv6hdr *hdr;
178
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 skb_postpull_rcsum(skb, skb->nh.raw,
185 skb->h.raw - skb->nh.raw);
186 hdr = skb->nh.ipv6h;
187 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) &&
194 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
195 goto discard;
196
197 ret = ipprot->handler(&skb, &nhoff);
198 if (ret > 0)
199 goto resubmit;
200 else if (ret == 0)
201 IP6_INC_STATS_BH(IPSTATS_MIB_INDELIVERS);
202 } else {
203 if (!raw_sk) {
204 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
205 IP6_INC_STATS_BH(IPSTATS_MIB_INUNKNOWNPROTOS);
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700206 icmpv6_send(skb, ICMPV6_PARAMPROB,
207 ICMPV6_UNK_NEXTHDR, nhoff,
208 skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 }
Patrick McHardyfad87ac2005-08-16 21:03:41 -0700210 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 IP6_INC_STATS_BH(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:
218 IP6_INC_STATS_BH(IPSTATS_MIB_INDISCARDS);
219 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
235 IP6_INC_STATS_BH(IPSTATS_MIB_INMCASTPKTS);
236
237 hdr = skb->nh.ipv6h;
238 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;
255
256 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}