Commit | Line | Data |
---|---|---|
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 | * | |
1da177e4 LT |
9 | * Based in linux/net/ipv4/ip_input.c |
10 | * | |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * as published by the Free Software Foundation; either version | |
14 | * 2 of the License, or (at your option) any later version. | |
15 | */ | |
16 | /* Changes | |
17 | * | |
67ba4152 IM |
18 | * Mitsuru KANDA @USAGI and |
19 | * YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs(). | |
1da177e4 LT |
20 | */ |
21 | ||
22 | #include <linux/errno.h> | |
23 | #include <linux/types.h> | |
24 | #include <linux/socket.h> | |
25 | #include <linux/sockios.h> | |
1da177e4 LT |
26 | #include <linux/net.h> |
27 | #include <linux/netdevice.h> | |
28 | #include <linux/in6.h> | |
29 | #include <linux/icmpv6.h> | |
7bc570c8 | 30 | #include <linux/mroute6.h> |
5a0e3ad6 | 31 | #include <linux/slab.h> |
1da177e4 LT |
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> | |
1f07d03e | 47 | #include <net/inet_ecn.h> |
48fb6b55 | 48 | #include <net/dst_metadata.h> |
1da177e4 | 49 | |
0c4b51f0 | 50 | int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 51 | { |
74b20582 DA |
52 | /* if ingress device is enslaved to an L3 master device pass the |
53 | * skb to its handler for processing | |
54 | */ | |
55 | skb = l3mdev_ip6_rcv(skb); | |
56 | if (!skb) | |
57 | return NET_RX_SUCCESS; | |
58 | ||
e21145a9 | 59 | if (net->ipv4.sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) { |
c7109986 ED |
60 | const struct inet6_protocol *ipprot; |
61 | ||
c7109986 ED |
62 | ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]); |
63 | if (ipprot && ipprot->early_demux) | |
64 | ipprot->early_demux(skb); | |
c7109986 | 65 | } |
48fb6b55 | 66 | if (!skb_valid_dst(skb)) |
1da177e4 LT |
67 | ip6_route_input(skb); |
68 | ||
69 | return dst_input(skb); | |
70 | } | |
71 | ||
f2ccd8fa | 72 | int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) |
1da177e4 | 73 | { |
b71d1d42 | 74 | const struct ipv6hdr *hdr; |
67ba4152 | 75 | u32 pkt_len; |
a11d206d | 76 | struct inet6_dev *idev; |
483a47d2 | 77 | struct net *net = dev_net(skb->dev); |
1da177e4 | 78 | |
a11d206d YH |
79 | if (skb->pkt_type == PACKET_OTHERHOST) { |
80 | kfree_skb(skb); | |
5c91face | 81 | return NET_RX_DROP; |
a11d206d YH |
82 | } |
83 | ||
84 | rcu_read_lock(); | |
1da177e4 | 85 | |
a11d206d YH |
86 | idev = __in6_dev_get(skb->dev); |
87 | ||
c2005eb0 | 88 | __IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_IN, skb->len); |
1da177e4 | 89 | |
778d80be YH |
90 | if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL || |
91 | !idev || unlikely(idev->cnf.disable_ipv6)) { | |
1d015503 | 92 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); |
71f6f6df | 93 | goto drop; |
1da177e4 LT |
94 | } |
95 | ||
6b7fdc3a GC |
96 | memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); |
97 | ||
1da177e4 LT |
98 | /* |
99 | * Store incoming device index. When the packet will | |
100 | * be queued, we cannot refer to skb->dev anymore. | |
101 | * | |
102 | * BTW, when we send a packet for our own local address on a | |
103 | * non-loopback interface (e.g. ethX), it is being delivered | |
de3cb747 | 104 | * via the loopback interface (lo) here; skb->dev = loopback_dev. |
1da177e4 LT |
105 | * It, however, should be considered as if it is being |
106 | * arrived via the sending interface (ethX), because of the | |
107 | * nature of scoping architecture. --yoshfuji | |
108 | */ | |
48fb6b55 | 109 | IP6CB(skb)->iif = skb_valid_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex; |
1da177e4 | 110 | |
2889139a | 111 | if (unlikely(!pskb_may_pull(skb, sizeof(*hdr)))) |
1da177e4 LT |
112 | goto err; |
113 | ||
0660e03f | 114 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
115 | |
116 | if (hdr->version != 6) | |
117 | goto err; | |
118 | ||
1d015503 ED |
119 | __IP6_ADD_STATS(net, idev, |
120 | IPSTATS_MIB_NOECTPKTS + | |
1f07d03e | 121 | (ipv6_get_dsfield(hdr) & INET_ECN_MASK), |
1d015503 | 122 | max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs)); |
f630e43a YH |
123 | /* |
124 | * RFC4291 2.5.3 | |
125 | * A packet received on an interface with a destination address | |
126 | * of loopback must be dropped. | |
127 | */ | |
128 | if (!(dev->flags & IFF_LOOPBACK) && | |
129 | ipv6_addr_loopback(&hdr->daddr)) | |
130 | goto err; | |
131 | ||
1c4a154e HFS |
132 | /* RFC4291 Errata ID: 3480 |
133 | * Interface-Local scope spans only a single interface on a | |
134 | * node and is useful only for loopback transmission of | |
135 | * multicast. Packets with interface-local scope received | |
136 | * from another node must be discarded. | |
137 | */ | |
138 | if (!(skb->pkt_type == PACKET_LOOPBACK || | |
139 | dev->flags & IFF_LOOPBACK) && | |
140 | ipv6_addr_is_multicast(&hdr->daddr) && | |
141 | IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1) | |
142 | goto err; | |
143 | ||
abbc3043 JB |
144 | /* If enabled, drop unicast packets that were encapsulated in link-layer |
145 | * multicast or broadcast to protected against the so-called "hole-196" | |
146 | * attack in 802.11 wireless. | |
147 | */ | |
148 | if (!ipv6_addr_is_multicast(&hdr->daddr) && | |
149 | (skb->pkt_type == PACKET_BROADCAST || | |
150 | skb->pkt_type == PACKET_MULTICAST) && | |
151 | idev->cnf.drop_unicast_in_l2_multicast) | |
152 | goto err; | |
153 | ||
20314092 HFS |
154 | /* RFC4291 2.7 |
155 | * Nodes must not originate a packet to a multicast address whose scope | |
156 | * field contains the reserved value 0; if such a packet is received, it | |
157 | * must be silently dropped. | |
158 | */ | |
159 | if (ipv6_addr_is_multicast(&hdr->daddr) && | |
160 | IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0) | |
161 | goto err; | |
162 | ||
c457338d BH |
163 | /* |
164 | * RFC4291 2.7 | |
165 | * Multicast addresses must not be used as source addresses in IPv6 | |
166 | * packets or appear in any Routing header. | |
167 | */ | |
168 | if (ipv6_addr_is_multicast(&hdr->saddr)) | |
169 | goto err; | |
170 | ||
b0e380b1 | 171 | skb->transport_header = skb->network_header + sizeof(*hdr); |
951dbc8a PM |
172 | IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr); |
173 | ||
1da177e4 LT |
174 | pkt_len = ntohs(hdr->payload_len); |
175 | ||
176 | /* pkt_len may be zero if Jumbo payload option is present */ | |
177 | if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) { | |
60e5c166 | 178 | if (pkt_len + sizeof(struct ipv6hdr) > skb->len) { |
1d015503 ED |
179 | __IP6_INC_STATS(net, |
180 | idev, IPSTATS_MIB_INTRUNCATEDPKTS); | |
60e5c166 MC |
181 | goto drop; |
182 | } | |
1da177e4 | 183 | if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) { |
1d015503 | 184 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
1da177e4 LT |
185 | goto drop; |
186 | } | |
0660e03f | 187 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
188 | } |
189 | ||
190 | if (hdr->nexthdr == NEXTHDR_HOP) { | |
e5bbef20 | 191 | if (ipv6_parse_hopopts(skb) < 0) { |
1d015503 | 192 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
a11d206d | 193 | rcu_read_unlock(); |
5c91face | 194 | return NET_RX_DROP; |
1da177e4 | 195 | } |
1da177e4 LT |
196 | } |
197 | ||
a11d206d YH |
198 | rcu_read_unlock(); |
199 | ||
71f9dacd HX |
200 | /* Must drop socket now because of tproxy. */ |
201 | skb_orphan(skb); | |
202 | ||
29a26a56 EB |
203 | return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, |
204 | net, NULL, skb, dev, NULL, | |
6e23ae2a | 205 | ip6_rcv_finish); |
1da177e4 | 206 | err: |
1d015503 | 207 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
1da177e4 | 208 | drop: |
a11d206d | 209 | rcu_read_unlock(); |
1da177e4 | 210 | kfree_skb(skb); |
5c91face | 211 | return NET_RX_DROP; |
1da177e4 LT |
212 | } |
213 | ||
214 | /* | |
215 | * Deliver the packet to the host | |
216 | */ | |
217 | ||
218 | ||
0c4b51f0 | 219 | static int ip6_input_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 220 | { |
41135cc8 | 221 | const struct inet6_protocol *ipprot; |
f9242b6b | 222 | struct inet6_dev *idev; |
1da177e4 | 223 | unsigned int nhoff; |
a50feda5 ED |
224 | int nexthdr; |
225 | bool raw; | |
1da44f9c | 226 | bool have_final = false; |
1da177e4 | 227 | |
1da177e4 LT |
228 | /* |
229 | * Parse extension headers | |
230 | */ | |
231 | ||
1da177e4 | 232 | rcu_read_lock(); |
1b0ccfe5 | 233 | resubmit: |
adf30907 | 234 | idev = ip6_dst_idev(skb_dst(skb)); |
ea2ae17d | 235 | if (!pskb_pull(skb, skb_transport_offset(skb))) |
1da177e4 | 236 | goto discard; |
951dbc8a | 237 | nhoff = IP6CB(skb)->nhoff; |
d56f90a7 | 238 | nexthdr = skb_network_header(skb)[nhoff]; |
1da177e4 | 239 | |
4c64242a | 240 | resubmit_final: |
69d6da0b | 241 | raw = raw6_local_deliver(skb, nexthdr); |
e5d08d71 | 242 | ipprot = rcu_dereference(inet6_protos[nexthdr]); |
53b24b8f | 243 | if (ipprot) { |
1da177e4 | 244 | int ret; |
1ab1457c | 245 | |
1da44f9c TH |
246 | if (have_final) { |
247 | if (!(ipprot->flags & INET6_PROTO_FINAL)) { | |
248 | /* Once we've seen a final protocol don't | |
249 | * allow encapsulation on any non-final | |
250 | * ones. This allows foo in UDP encapsulation | |
251 | * to work. | |
252 | */ | |
253 | goto discard; | |
254 | } | |
255 | } else if (ipprot->flags & INET6_PROTO_FINAL) { | |
b71d1d42 | 256 | const struct ipv6hdr *hdr; |
1da177e4 | 257 | |
1da44f9c TH |
258 | /* Only do this once for first final protocol */ |
259 | have_final = true; | |
260 | ||
9fb9cbb1 YK |
261 | /* Free reference early: we don't need it any more, |
262 | and it may hold ip_conntrack module loaded | |
263 | indefinitely. */ | |
264 | nf_reset(skb); | |
265 | ||
d56f90a7 | 266 | skb_postpull_rcsum(skb, skb_network_header(skb), |
cfe1fc77 | 267 | skb_network_header_len(skb)); |
0660e03f | 268 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
269 | if (ipv6_addr_is_multicast(&hdr->daddr) && |
270 | !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, | |
271 | &hdr->saddr) && | |
daad1512 | 272 | !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb))) |
1da177e4 LT |
273 | goto discard; |
274 | } | |
275 | if (!(ipprot->flags & INET6_PROTO_NOPOLICY) && | |
1ab1457c | 276 | !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) |
1da177e4 | 277 | goto discard; |
1ab1457c | 278 | |
e5bbef20 | 279 | ret = ipprot->handler(skb); |
4c64242a TH |
280 | if (ret > 0) { |
281 | if (ipprot->flags & INET6_PROTO_FINAL) { | |
282 | /* Not an extension header, most likely UDP | |
283 | * encapsulation. Use return value as nexthdr | |
284 | * protocol not nhoff (which presumably is | |
285 | * not set by handler). | |
286 | */ | |
287 | nexthdr = ret; | |
288 | goto resubmit_final; | |
289 | } else { | |
290 | goto resubmit; | |
291 | } | |
292 | } else if (ret == 0) { | |
1d015503 | 293 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS); |
4c64242a | 294 | } |
1da177e4 | 295 | } else { |
69d6da0b | 296 | if (!raw) { |
1da177e4 | 297 | if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
1d015503 ED |
298 | __IP6_INC_STATS(net, idev, |
299 | IPSTATS_MIB_INUNKNOWNPROTOS); | |
fad87aca | 300 | icmpv6_send(skb, ICMPV6_PARAMPROB, |
3ffe533c | 301 | ICMPV6_UNK_NEXTHDR, nhoff); |
1da177e4 | 302 | } |
d8c6f4b9 NH |
303 | kfree_skb(skb); |
304 | } else { | |
1d015503 | 305 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS); |
d8c6f4b9 NH |
306 | consume_skb(skb); |
307 | } | |
1da177e4 LT |
308 | } |
309 | rcu_read_unlock(); | |
310 | return 0; | |
311 | ||
312 | discard: | |
1d015503 | 313 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); |
1da177e4 LT |
314 | rcu_read_unlock(); |
315 | kfree_skb(skb); | |
316 | return 0; | |
317 | } | |
318 | ||
319 | ||
320 | int ip6_input(struct sk_buff *skb) | |
321 | { | |
29a26a56 EB |
322 | return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, |
323 | dev_net(skb->dev), NULL, skb, skb->dev, NULL, | |
6e23ae2a | 324 | ip6_input_finish); |
1da177e4 LT |
325 | } |
326 | ||
327 | int ip6_mc_input(struct sk_buff *skb) | |
328 | { | |
b71d1d42 | 329 | const struct ipv6hdr *hdr; |
a50feda5 | 330 | bool deliver; |
1da177e4 | 331 | |
c2005eb0 | 332 | __IP6_UPD_PO_STATS(dev_net(skb_dst(skb)->dev), |
adf30907 | 333 | ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST, |
edf391ff | 334 | skb->len); |
1da177e4 | 335 | |
0660e03f | 336 | hdr = ipv6_hdr(skb); |
4c7966b8 | 337 | deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL); |
1da177e4 | 338 | |
7bc570c8 | 339 | #ifdef CONFIG_IPV6_MROUTE |
1da177e4 | 340 | /* |
7bc570c8 | 341 | * IPv6 multicast router mode is now supported ;) |
1da177e4 | 342 | */ |
53b7997f | 343 | if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding && |
ddf64354 HFS |
344 | !(ipv6_addr_type(&hdr->daddr) & |
345 | (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) && | |
7bc570c8 YH |
346 | likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) { |
347 | /* | |
348 | * Okay, we try to forward - split and duplicate | |
349 | * packets. | |
350 | */ | |
351 | struct sk_buff *skb2; | |
352 | struct inet6_skb_parm *opt = IP6CB(skb); | |
353 | ||
354 | /* Check for MLD */ | |
dd3332bf | 355 | if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) { |
7bc570c8 | 356 | /* Check if this is a mld message */ |
7bc570c8 | 357 | u8 nexthdr = hdr->nexthdr; |
75f2811c | 358 | __be16 frag_off; |
7bc570c8 YH |
359 | int offset; |
360 | ||
361 | /* Check if the value of Router Alert | |
362 | * is for MLD (0x0000). | |
363 | */ | |
dd3332bf | 364 | if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) { |
a50feda5 | 365 | deliver = false; |
aba6096b | 366 | |
7bc570c8 YH |
367 | if (!ipv6_ext_hdr(nexthdr)) { |
368 | /* BUG */ | |
aba6096b | 369 | goto out; |
7bc570c8 YH |
370 | } |
371 | offset = ipv6_skip_exthdr(skb, sizeof(*hdr), | |
75f2811c | 372 | &nexthdr, &frag_off); |
7bc570c8 | 373 | if (offset < 0) |
aba6096b | 374 | goto out; |
7bc570c8 | 375 | |
4c938d22 A |
376 | if (ipv6_is_mld(skb, nexthdr, offset)) |
377 | deliver = true; | |
7bc570c8 | 378 | |
4c938d22 | 379 | goto out; |
7bc570c8 YH |
380 | } |
381 | /* unknown RA - process it normally */ | |
382 | } | |
1da177e4 | 383 | |
7bc570c8 YH |
384 | if (deliver) |
385 | skb2 = skb_clone(skb, GFP_ATOMIC); | |
386 | else { | |
387 | skb2 = skb; | |
388 | skb = NULL; | |
389 | } | |
1ab1457c | 390 | |
7bc570c8 | 391 | if (skb2) { |
7bc570c8 | 392 | ip6_mr_input(skb2); |
1da177e4 LT |
393 | } |
394 | } | |
7bc570c8 | 395 | out: |
aba6096b YH |
396 | #endif |
397 | if (likely(deliver)) | |
1da177e4 | 398 | ip6_input(skb); |
aba6096b YH |
399 | else { |
400 | /* discard */ | |
401 | kfree_skb(skb); | |
1da177e4 | 402 | } |
1da177e4 LT |
403 | |
404 | return 0; | |
405 | } |