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[IPV6]: Clean skb cb on IPv6 input.
[mirror_ubuntu-zesty-kernel.git] / net / ipv6 / ip6_input.c
CommitLineData
1da177e4
LT
1/*
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
b05e1066 51inline int ip6_rcv_finish( struct sk_buff *skb)
1da177e4
LT
52{
53 if (skb->dst == NULL)
54 ip6_route_input(skb);
55
56 return dst_input(skb);
57}
58
f2ccd8fa 59int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
1da177e4
LT
60{
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
6b7fdc3a
GC
74 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
75
1da177e4
LT
76 /*
77 * Store incoming device index. When the packet will
78 * be queued, we cannot refer to skb->dev anymore.
79 *
80 * BTW, when we send a packet for our own local address on a
81 * non-loopback interface (e.g. ethX), it is being delivered
82 * via the loopback interface (lo) here; skb->dev = &loopback_dev.
83 * It, however, should be considered as if it is being
84 * arrived via the sending interface (ethX), because of the
85 * nature of scoping architecture. --yoshfuji
86 */
87 IP6CB(skb)->iif = skb->dst ? ((struct rt6_info *)skb->dst)->rt6i_idev->dev->ifindex : dev->ifindex;
88
2889139a 89 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
1da177e4
LT
90 goto err;
91
1da177e4
LT
92 hdr = skb->nh.ipv6h;
93
94 if (hdr->version != 6)
95 goto err;
96
951dbc8a
PM
97 skb->h.raw = (u8 *)(hdr + 1);
98 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
99
1da177e4
LT
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) {
b809739a 114 if (ipv6_parse_hopopts(skb) < 0) {
1da177e4
LT
115 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
116 return 0;
117 }
1da177e4
LT
118 }
119
120 return NF_HOOK(PF_INET6,NF_IP6_PRE_ROUTING, skb, dev, NULL, ip6_rcv_finish);
121truncated:
122 IP6_INC_STATS_BH(IPSTATS_MIB_INTRUNCATEDPKTS);
123err:
124 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
125drop:
126 kfree_skb(skb);
127out:
128 return 0;
129}
130
131/*
132 * Deliver the packet to the host
133 */
134
135
136static inline int ip6_input_finish(struct sk_buff *skb)
137{
138 struct inet6_protocol *ipprot;
139 struct sock *raw_sk;
140 unsigned int nhoff;
141 int nexthdr;
142 u8 hash;
143
1da177e4
LT
144 /*
145 * Parse extension headers
146 */
147
1da177e4
LT
148 rcu_read_lock();
149resubmit:
150 if (!pskb_pull(skb, skb->h.raw - skb->data))
151 goto discard;
951dbc8a 152 nhoff = IP6CB(skb)->nhoff;
1da177e4
LT
153 nexthdr = skb->nh.raw[nhoff];
154
155 raw_sk = sk_head(&raw_v6_htable[nexthdr & (MAX_INET_PROTOS - 1)]);
d13964f4
PM
156 if (raw_sk && !ipv6_raw_deliver(skb, nexthdr))
157 raw_sk = NULL;
1da177e4
LT
158
159 hash = nexthdr & (MAX_INET_PROTOS - 1);
160 if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
161 int ret;
162
163 if (ipprot->flags & INET6_PROTO_FINAL) {
164 struct ipv6hdr *hdr;
165
9fb9cbb1
YK
166 /* Free reference early: we don't need it any more,
167 and it may hold ip_conntrack module loaded
168 indefinitely. */
169 nf_reset(skb);
170
1da177e4
LT
171 skb_postpull_rcsum(skb, skb->nh.raw,
172 skb->h.raw - skb->nh.raw);
173 hdr = skb->nh.ipv6h;
174 if (ipv6_addr_is_multicast(&hdr->daddr) &&
175 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
176 &hdr->saddr) &&
177 !ipv6_is_mld(skb, nexthdr))
178 goto discard;
179 }
180 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
181 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
182 goto discard;
183
951dbc8a 184 ret = ipprot->handler(&skb);
1da177e4
LT
185 if (ret > 0)
186 goto resubmit;
187 else if (ret == 0)
188 IP6_INC_STATS_BH(IPSTATS_MIB_INDELIVERS);
189 } else {
190 if (!raw_sk) {
191 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
192 IP6_INC_STATS_BH(IPSTATS_MIB_INUNKNOWNPROTOS);
fad87aca
PM
193 icmpv6_send(skb, ICMPV6_PARAMPROB,
194 ICMPV6_UNK_NEXTHDR, nhoff,
195 skb->dev);
1da177e4 196 }
fad87aca 197 } else
1da177e4 198 IP6_INC_STATS_BH(IPSTATS_MIB_INDELIVERS);
fad87aca 199 kfree_skb(skb);
1da177e4
LT
200 }
201 rcu_read_unlock();
202 return 0;
203
204discard:
205 IP6_INC_STATS_BH(IPSTATS_MIB_INDISCARDS);
206 rcu_read_unlock();
207 kfree_skb(skb);
208 return 0;
209}
210
211
212int ip6_input(struct sk_buff *skb)
213{
214 return NF_HOOK(PF_INET6,NF_IP6_LOCAL_IN, skb, skb->dev, NULL, ip6_input_finish);
215}
216
217int ip6_mc_input(struct sk_buff *skb)
218{
219 struct ipv6hdr *hdr;
220 int deliver;
221
222 IP6_INC_STATS_BH(IPSTATS_MIB_INMCASTPKTS);
223
224 hdr = skb->nh.ipv6h;
225 deliver = likely(!(skb->dev->flags & (IFF_PROMISC|IFF_ALLMULTI))) ||
226 ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
227
228 /*
229 * IPv6 multicast router mode isnt currently supported.
230 */
231#if 0
232 if (ipv6_config.multicast_route) {
233 int addr_type;
234
235 addr_type = ipv6_addr_type(&hdr->daddr);
236
237 if (!(addr_type & (IPV6_ADDR_LOOPBACK | IPV6_ADDR_LINKLOCAL))) {
238 struct sk_buff *skb2;
239 struct dst_entry *dst;
240
241 dst = skb->dst;
242
243 if (deliver) {
244 skb2 = skb_clone(skb, GFP_ATOMIC);
245 dst_output(skb2);
246 } else {
247 dst_output(skb);
248 return 0;
249 }
250 }
251 }
252#endif
253
254 if (likely(deliver)) {
255 ip6_input(skb);
256 return 0;
257 }
258 /* discard */
259 kfree_skb(skb);
260
261 return 0;
262}