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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * IPv6 input | |
1ab1457c | 3 | * Linux INET6 implementation |
1da177e4 LT |
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> | |
1da177e4 LT |
28 | #include <linux/net.h> |
29 | #include <linux/netdevice.h> | |
30 | #include <linux/in6.h> | |
31 | #include <linux/icmpv6.h> | |
7bc570c8 | 32 | #include <linux/mroute6.h> |
1da177e4 LT |
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 | ||
1ab1457c | 51 | inline 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 | 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; | |
a11d206d | 63 | struct inet6_dev *idev; |
1da177e4 | 64 | |
a11d206d YH |
65 | if (skb->pkt_type == PACKET_OTHERHOST) { |
66 | kfree_skb(skb); | |
67 | return 0; | |
68 | } | |
69 | ||
70 | rcu_read_lock(); | |
1da177e4 | 71 | |
a11d206d YH |
72 | idev = __in6_dev_get(skb->dev); |
73 | ||
74 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_INRECEIVES); | |
1da177e4 LT |
75 | |
76 | if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) { | |
a11d206d YH |
77 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS); |
78 | rcu_read_unlock(); | |
1da177e4 LT |
79 | goto out; |
80 | } | |
81 | ||
6b7fdc3a GC |
82 | memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); |
83 | ||
1da177e4 LT |
84 | /* |
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 | |
de3cb747 | 90 | * via the loopback interface (lo) here; skb->dev = loopback_dev. |
1da177e4 LT |
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 | */ | |
7a3025b1 | 95 | IP6CB(skb)->iif = skb->dst ? ip6_dst_idev(skb->dst)->dev->ifindex : dev->ifindex; |
1da177e4 | 96 | |
2889139a | 97 | if (unlikely(!pskb_may_pull(skb, sizeof(*hdr)))) |
1da177e4 LT |
98 | goto err; |
99 | ||
0660e03f | 100 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
101 | |
102 | if (hdr->version != 6) | |
103 | goto err; | |
104 | ||
b0e380b1 | 105 | skb->transport_header = skb->network_header + sizeof(*hdr); |
951dbc8a PM |
106 | IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr); |
107 | ||
1da177e4 LT |
108 | 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) { | |
60e5c166 MC |
112 | if (pkt_len + sizeof(struct ipv6hdr) > skb->len) { |
113 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_INTRUNCATEDPKTS); | |
114 | goto drop; | |
115 | } | |
1da177e4 | 116 | if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) { |
a11d206d | 117 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS); |
1da177e4 LT |
118 | goto drop; |
119 | } | |
0660e03f | 120 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
121 | } |
122 | ||
123 | if (hdr->nexthdr == NEXTHDR_HOP) { | |
e5bbef20 | 124 | if (ipv6_parse_hopopts(skb) < 0) { |
a11d206d YH |
125 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS); |
126 | rcu_read_unlock(); | |
1da177e4 LT |
127 | return 0; |
128 | } | |
1da177e4 LT |
129 | } |
130 | ||
a11d206d YH |
131 | rcu_read_unlock(); |
132 | ||
6e23ae2a PM |
133 | return NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, dev, NULL, |
134 | ip6_rcv_finish); | |
1da177e4 | 135 | err: |
a11d206d | 136 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS); |
1da177e4 | 137 | drop: |
a11d206d | 138 | rcu_read_unlock(); |
1da177e4 LT |
139 | kfree_skb(skb); |
140 | out: | |
141 | return 0; | |
142 | } | |
143 | ||
144 | /* | |
145 | * Deliver the packet to the host | |
146 | */ | |
147 | ||
148 | ||
ad643a79 | 149 | static int ip6_input_finish(struct sk_buff *skb) |
1da177e4 LT |
150 | { |
151 | struct inet6_protocol *ipprot; | |
1da177e4 | 152 | unsigned int nhoff; |
69d6da0b | 153 | int nexthdr, raw; |
1da177e4 | 154 | u8 hash; |
a11d206d | 155 | struct inet6_dev *idev; |
1da177e4 | 156 | |
1da177e4 LT |
157 | /* |
158 | * Parse extension headers | |
159 | */ | |
160 | ||
1da177e4 LT |
161 | rcu_read_lock(); |
162 | resubmit: | |
a11d206d | 163 | idev = ip6_dst_idev(skb->dst); |
ea2ae17d | 164 | if (!pskb_pull(skb, skb_transport_offset(skb))) |
1da177e4 | 165 | goto discard; |
951dbc8a | 166 | nhoff = IP6CB(skb)->nhoff; |
d56f90a7 | 167 | nexthdr = skb_network_header(skb)[nhoff]; |
1da177e4 | 168 | |
69d6da0b | 169 | raw = raw6_local_deliver(skb, nexthdr); |
1da177e4 LT |
170 | |
171 | hash = nexthdr & (MAX_INET_PROTOS - 1); | |
172 | if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) { | |
173 | int ret; | |
1ab1457c | 174 | |
1da177e4 | 175 | if (ipprot->flags & INET6_PROTO_FINAL) { |
1ab1457c | 176 | struct ipv6hdr *hdr; |
1da177e4 | 177 | |
9fb9cbb1 YK |
178 | /* Free reference early: we don't need it any more, |
179 | and it may hold ip_conntrack module loaded | |
180 | indefinitely. */ | |
181 | nf_reset(skb); | |
182 | ||
d56f90a7 | 183 | skb_postpull_rcsum(skb, skb_network_header(skb), |
cfe1fc77 | 184 | skb_network_header_len(skb)); |
0660e03f | 185 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
186 | if (ipv6_addr_is_multicast(&hdr->daddr) && |
187 | !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, | |
188 | &hdr->saddr) && | |
189 | !ipv6_is_mld(skb, nexthdr)) | |
190 | goto discard; | |
191 | } | |
192 | if (!(ipprot->flags & INET6_PROTO_NOPOLICY) && | |
1ab1457c | 193 | !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) |
1da177e4 | 194 | goto discard; |
1ab1457c | 195 | |
e5bbef20 | 196 | ret = ipprot->handler(skb); |
1da177e4 LT |
197 | if (ret > 0) |
198 | goto resubmit; | |
199 | else if (ret == 0) | |
a11d206d | 200 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS); |
1da177e4 | 201 | } else { |
69d6da0b | 202 | if (!raw) { |
1da177e4 | 203 | if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
a11d206d | 204 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_INUNKNOWNPROTOS); |
fad87aca | 205 | icmpv6_send(skb, ICMPV6_PARAMPROB, |
1ab1457c YH |
206 | ICMPV6_UNK_NEXTHDR, nhoff, |
207 | skb->dev); | |
1da177e4 | 208 | } |
fad87aca | 209 | } else |
a11d206d | 210 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS); |
fad87aca | 211 | kfree_skb(skb); |
1da177e4 LT |
212 | } |
213 | rcu_read_unlock(); | |
214 | return 0; | |
215 | ||
216 | discard: | |
a11d206d | 217 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS); |
1da177e4 LT |
218 | rcu_read_unlock(); |
219 | kfree_skb(skb); | |
220 | return 0; | |
221 | } | |
222 | ||
223 | ||
224 | int ip6_input(struct sk_buff *skb) | |
225 | { | |
6e23ae2a PM |
226 | return NF_HOOK(PF_INET6, NF_INET_LOCAL_IN, skb, skb->dev, NULL, |
227 | ip6_input_finish); | |
1da177e4 LT |
228 | } |
229 | ||
230 | int ip6_mc_input(struct sk_buff *skb) | |
231 | { | |
232 | struct ipv6hdr *hdr; | |
233 | int deliver; | |
234 | ||
a11d206d | 235 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS); |
1da177e4 | 236 | |
0660e03f | 237 | hdr = ipv6_hdr(skb); |
4c7966b8 | 238 | deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL); |
1da177e4 | 239 | |
7bc570c8 | 240 | #ifdef CONFIG_IPV6_MROUTE |
1da177e4 | 241 | /* |
7bc570c8 | 242 | * IPv6 multicast router mode is now supported ;) |
1da177e4 | 243 | */ |
7bc570c8 YH |
244 | if (ipv6_devconf.mc_forwarding && |
245 | likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) { | |
246 | /* | |
247 | * Okay, we try to forward - split and duplicate | |
248 | * packets. | |
249 | */ | |
250 | struct sk_buff *skb2; | |
251 | struct inet6_skb_parm *opt = IP6CB(skb); | |
252 | ||
253 | /* Check for MLD */ | |
254 | if (unlikely(opt->ra)) { | |
255 | /* Check if this is a mld message */ | |
256 | u8 *ptr = skb_network_header(skb) + opt->ra; | |
257 | struct icmp6hdr *icmp6; | |
258 | u8 nexthdr = hdr->nexthdr; | |
259 | int offset; | |
260 | ||
261 | /* Check if the value of Router Alert | |
262 | * is for MLD (0x0000). | |
263 | */ | |
264 | if ((ptr[2] | ptr[3]) == 0) { | |
265 | if (!ipv6_ext_hdr(nexthdr)) { | |
266 | /* BUG */ | |
267 | goto discard; | |
268 | } | |
269 | offset = ipv6_skip_exthdr(skb, sizeof(*hdr), | |
270 | &nexthdr); | |
271 | if (offset < 0) | |
272 | goto discard; | |
273 | ||
274 | if (nexthdr != IPPROTO_ICMPV6) | |
275 | goto discard; | |
276 | ||
277 | if (!pskb_may_pull(skb, (skb_network_header(skb) + | |
278 | offset + 1 - skb->data))) | |
279 | goto discard; | |
280 | ||
281 | icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); | |
282 | ||
283 | switch (icmp6->icmp6_type) { | |
284 | case ICMPV6_MGM_QUERY: | |
285 | case ICMPV6_MGM_REPORT: | |
286 | case ICMPV6_MGM_REDUCTION: | |
287 | case ICMPV6_MLD2_REPORT: | |
288 | break; | |
289 | default: | |
290 | /* Bogus */ | |
291 | goto discard; | |
292 | } | |
293 | deliver = 1; | |
294 | goto out; | |
295 | } | |
296 | /* unknown RA - process it normally */ | |
297 | } | |
1da177e4 | 298 | |
7bc570c8 YH |
299 | if (deliver) |
300 | skb2 = skb_clone(skb, GFP_ATOMIC); | |
301 | else { | |
302 | skb2 = skb; | |
303 | skb = NULL; | |
304 | } | |
1ab1457c | 305 | |
7bc570c8 YH |
306 | if (skb2) { |
307 | skb2->dev = skb2->dst->dev; | |
308 | ip6_mr_input(skb2); | |
1da177e4 LT |
309 | } |
310 | } | |
311 | #endif | |
7bc570c8 | 312 | out: |
1da177e4 LT |
313 | if (likely(deliver)) { |
314 | ip6_input(skb); | |
315 | return 0; | |
316 | } | |
7bc570c8 | 317 | discard: |
1da177e4 LT |
318 | /* discard */ |
319 | kfree_skb(skb); | |
320 | ||
321 | return 0; | |
322 | } |