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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 | ||
51 | static 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 | ||
f2ccd8fa | 59 | int 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 | ||
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); | |
123 | truncated: | |
124 | IP6_INC_STATS_BH(IPSTATS_MIB_INTRUNCATEDPKTS); | |
125 | err: | |
126 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
127 | drop: | |
128 | kfree_skb(skb); | |
129 | out: | |
130 | return 0; | |
131 | } | |
132 | ||
133 | /* | |
134 | * Deliver the packet to the host | |
135 | */ | |
136 | ||
137 | ||
138 | static 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(); | |
163 | resubmit: | |
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)]); | |
d13964f4 PM |
169 | if (raw_sk && !ipv6_raw_deliver(skb, nexthdr)) |
170 | raw_sk = NULL; | |
1da177e4 LT |
171 | |
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 | ||
179 | skb_postpull_rcsum(skb, skb->nh.raw, | |
180 | skb->h.raw - skb->nh.raw); | |
181 | hdr = skb->nh.ipv6h; | |
182 | if (ipv6_addr_is_multicast(&hdr->daddr) && | |
183 | !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, | |
184 | &hdr->saddr) && | |
185 | !ipv6_is_mld(skb, nexthdr)) | |
186 | goto discard; | |
187 | } | |
188 | if (!(ipprot->flags & INET6_PROTO_NOPOLICY) && | |
189 | !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) | |
190 | goto discard; | |
191 | ||
192 | ret = ipprot->handler(&skb, &nhoff); | |
193 | if (ret > 0) | |
194 | goto resubmit; | |
195 | else if (ret == 0) | |
196 | IP6_INC_STATS_BH(IPSTATS_MIB_INDELIVERS); | |
197 | } else { | |
198 | if (!raw_sk) { | |
199 | if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
200 | IP6_INC_STATS_BH(IPSTATS_MIB_INUNKNOWNPROTOS); | |
fad87aca PM |
201 | icmpv6_send(skb, ICMPV6_PARAMPROB, |
202 | ICMPV6_UNK_NEXTHDR, nhoff, | |
203 | skb->dev); | |
1da177e4 | 204 | } |
fad87aca | 205 | } else |
1da177e4 | 206 | IP6_INC_STATS_BH(IPSTATS_MIB_INDELIVERS); |
fad87aca | 207 | kfree_skb(skb); |
1da177e4 LT |
208 | } |
209 | rcu_read_unlock(); | |
210 | return 0; | |
211 | ||
212 | discard: | |
213 | IP6_INC_STATS_BH(IPSTATS_MIB_INDISCARDS); | |
214 | rcu_read_unlock(); | |
215 | kfree_skb(skb); | |
216 | return 0; | |
217 | } | |
218 | ||
219 | ||
220 | int ip6_input(struct sk_buff *skb) | |
221 | { | |
222 | return NF_HOOK(PF_INET6,NF_IP6_LOCAL_IN, skb, skb->dev, NULL, ip6_input_finish); | |
223 | } | |
224 | ||
225 | int ip6_mc_input(struct sk_buff *skb) | |
226 | { | |
227 | struct ipv6hdr *hdr; | |
228 | int deliver; | |
229 | ||
230 | IP6_INC_STATS_BH(IPSTATS_MIB_INMCASTPKTS); | |
231 | ||
232 | hdr = skb->nh.ipv6h; | |
233 | deliver = likely(!(skb->dev->flags & (IFF_PROMISC|IFF_ALLMULTI))) || | |
234 | ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL); | |
235 | ||
236 | /* | |
237 | * IPv6 multicast router mode isnt currently supported. | |
238 | */ | |
239 | #if 0 | |
240 | if (ipv6_config.multicast_route) { | |
241 | int addr_type; | |
242 | ||
243 | addr_type = ipv6_addr_type(&hdr->daddr); | |
244 | ||
245 | if (!(addr_type & (IPV6_ADDR_LOOPBACK | IPV6_ADDR_LINKLOCAL))) { | |
246 | struct sk_buff *skb2; | |
247 | struct dst_entry *dst; | |
248 | ||
249 | dst = skb->dst; | |
250 | ||
251 | if (deliver) { | |
252 | skb2 = skb_clone(skb, GFP_ATOMIC); | |
253 | dst_output(skb2); | |
254 | } else { | |
255 | dst_output(skb); | |
256 | return 0; | |
257 | } | |
258 | } | |
259 | } | |
260 | #endif | |
261 | ||
262 | if (likely(deliver)) { | |
263 | ip6_input(skb); | |
264 | return 0; | |
265 | } | |
266 | /* discard */ | |
267 | kfree_skb(skb); | |
268 | ||
269 | return 0; | |
270 | } |