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> |
1da177e4 LT |
48 | |
49 | ||
c7109986 | 50 | int ip6_rcv_finish(struct sk_buff *skb) |
1da177e4 | 51 | { |
a452ce34 | 52 | if (sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) { |
c7109986 ED |
53 | const struct inet6_protocol *ipprot; |
54 | ||
c7109986 ED |
55 | ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]); |
56 | if (ipprot && ipprot->early_demux) | |
57 | ipprot->early_demux(skb); | |
c7109986 ED |
58 | } |
59 | if (!skb_dst(skb)) | |
1da177e4 LT |
60 | ip6_route_input(skb); |
61 | ||
62 | return dst_input(skb); | |
63 | } | |
64 | ||
f2ccd8fa | 65 | int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) |
1da177e4 | 66 | { |
b71d1d42 | 67 | const struct ipv6hdr *hdr; |
67ba4152 | 68 | u32 pkt_len; |
a11d206d | 69 | struct inet6_dev *idev; |
483a47d2 | 70 | struct net *net = dev_net(skb->dev); |
1da177e4 | 71 | |
a11d206d YH |
72 | if (skb->pkt_type == PACKET_OTHERHOST) { |
73 | kfree_skb(skb); | |
5c91face | 74 | return NET_RX_DROP; |
a11d206d YH |
75 | } |
76 | ||
77 | rcu_read_lock(); | |
1da177e4 | 78 | |
a11d206d YH |
79 | idev = __in6_dev_get(skb->dev); |
80 | ||
edf391ff | 81 | IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len); |
1da177e4 | 82 | |
778d80be YH |
83 | if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL || |
84 | !idev || unlikely(idev->cnf.disable_ipv6)) { | |
483a47d2 | 85 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS); |
71f6f6df | 86 | goto drop; |
1da177e4 LT |
87 | } |
88 | ||
6b7fdc3a GC |
89 | memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); |
90 | ||
1da177e4 LT |
91 | /* |
92 | * Store incoming device index. When the packet will | |
93 | * be queued, we cannot refer to skb->dev anymore. | |
94 | * | |
95 | * BTW, when we send a packet for our own local address on a | |
96 | * non-loopback interface (e.g. ethX), it is being delivered | |
de3cb747 | 97 | * via the loopback interface (lo) here; skb->dev = loopback_dev. |
1da177e4 LT |
98 | * It, however, should be considered as if it is being |
99 | * arrived via the sending interface (ethX), because of the | |
100 | * nature of scoping architecture. --yoshfuji | |
101 | */ | |
adf30907 | 102 | IP6CB(skb)->iif = skb_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex; |
1da177e4 | 103 | |
2889139a | 104 | if (unlikely(!pskb_may_pull(skb, sizeof(*hdr)))) |
1da177e4 LT |
105 | goto err; |
106 | ||
0660e03f | 107 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
108 | |
109 | if (hdr->version != 6) | |
110 | goto err; | |
111 | ||
1f07d03e ED |
112 | IP6_ADD_STATS_BH(dev_net(dev), idev, |
113 | IPSTATS_MIB_NOECTPKTS + | |
114 | (ipv6_get_dsfield(hdr) & INET_ECN_MASK), | |
115 | max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs)); | |
f630e43a YH |
116 | /* |
117 | * RFC4291 2.5.3 | |
118 | * A packet received on an interface with a destination address | |
119 | * of loopback must be dropped. | |
120 | */ | |
121 | if (!(dev->flags & IFF_LOOPBACK) && | |
122 | ipv6_addr_loopback(&hdr->daddr)) | |
123 | goto err; | |
124 | ||
1c4a154e HFS |
125 | /* RFC4291 Errata ID: 3480 |
126 | * Interface-Local scope spans only a single interface on a | |
127 | * node and is useful only for loopback transmission of | |
128 | * multicast. Packets with interface-local scope received | |
129 | * from another node must be discarded. | |
130 | */ | |
131 | if (!(skb->pkt_type == PACKET_LOOPBACK || | |
132 | dev->flags & IFF_LOOPBACK) && | |
133 | ipv6_addr_is_multicast(&hdr->daddr) && | |
134 | IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1) | |
135 | goto err; | |
136 | ||
20314092 HFS |
137 | /* RFC4291 2.7 |
138 | * Nodes must not originate a packet to a multicast address whose scope | |
139 | * field contains the reserved value 0; if such a packet is received, it | |
140 | * must be silently dropped. | |
141 | */ | |
142 | if (ipv6_addr_is_multicast(&hdr->daddr) && | |
143 | IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0) | |
144 | goto err; | |
145 | ||
c457338d BH |
146 | /* |
147 | * RFC4291 2.7 | |
148 | * Multicast addresses must not be used as source addresses in IPv6 | |
149 | * packets or appear in any Routing header. | |
150 | */ | |
151 | if (ipv6_addr_is_multicast(&hdr->saddr)) | |
152 | goto err; | |
153 | ||
b0e380b1 | 154 | skb->transport_header = skb->network_header + sizeof(*hdr); |
951dbc8a PM |
155 | IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr); |
156 | ||
1da177e4 LT |
157 | pkt_len = ntohs(hdr->payload_len); |
158 | ||
159 | /* pkt_len may be zero if Jumbo payload option is present */ | |
160 | if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) { | |
60e5c166 | 161 | if (pkt_len + sizeof(struct ipv6hdr) > skb->len) { |
483a47d2 DL |
162 | IP6_INC_STATS_BH(net, |
163 | idev, IPSTATS_MIB_INTRUNCATEDPKTS); | |
60e5c166 MC |
164 | goto drop; |
165 | } | |
1da177e4 | 166 | if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) { |
483a47d2 | 167 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS); |
1da177e4 LT |
168 | goto drop; |
169 | } | |
0660e03f | 170 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
171 | } |
172 | ||
173 | if (hdr->nexthdr == NEXTHDR_HOP) { | |
e5bbef20 | 174 | if (ipv6_parse_hopopts(skb) < 0) { |
483a47d2 | 175 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS); |
a11d206d | 176 | rcu_read_unlock(); |
5c91face | 177 | return NET_RX_DROP; |
1da177e4 | 178 | } |
1da177e4 LT |
179 | } |
180 | ||
a11d206d YH |
181 | rcu_read_unlock(); |
182 | ||
71f9dacd HX |
183 | /* Must drop socket now because of tproxy. */ |
184 | skb_orphan(skb); | |
185 | ||
b2e0b385 | 186 | return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, dev, NULL, |
6e23ae2a | 187 | ip6_rcv_finish); |
1da177e4 | 188 | err: |
483a47d2 | 189 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS); |
1da177e4 | 190 | drop: |
a11d206d | 191 | rcu_read_unlock(); |
1da177e4 | 192 | kfree_skb(skb); |
5c91face | 193 | return NET_RX_DROP; |
1da177e4 LT |
194 | } |
195 | ||
196 | /* | |
197 | * Deliver the packet to the host | |
198 | */ | |
199 | ||
200 | ||
ad643a79 | 201 | static int ip6_input_finish(struct sk_buff *skb) |
1da177e4 | 202 | { |
f9242b6b | 203 | struct net *net = dev_net(skb_dst(skb)->dev); |
41135cc8 | 204 | const struct inet6_protocol *ipprot; |
f9242b6b | 205 | struct inet6_dev *idev; |
1da177e4 | 206 | unsigned int nhoff; |
a50feda5 ED |
207 | int nexthdr; |
208 | bool raw; | |
1da177e4 | 209 | |
1da177e4 LT |
210 | /* |
211 | * Parse extension headers | |
212 | */ | |
213 | ||
1da177e4 LT |
214 | rcu_read_lock(); |
215 | resubmit: | |
adf30907 | 216 | idev = ip6_dst_idev(skb_dst(skb)); |
ea2ae17d | 217 | if (!pskb_pull(skb, skb_transport_offset(skb))) |
1da177e4 | 218 | goto discard; |
951dbc8a | 219 | nhoff = IP6CB(skb)->nhoff; |
d56f90a7 | 220 | nexthdr = skb_network_header(skb)[nhoff]; |
1da177e4 | 221 | |
69d6da0b | 222 | raw = raw6_local_deliver(skb, nexthdr); |
f9242b6b | 223 | if ((ipprot = rcu_dereference(inet6_protos[nexthdr])) != NULL) { |
1da177e4 | 224 | int ret; |
1ab1457c | 225 | |
1da177e4 | 226 | if (ipprot->flags & INET6_PROTO_FINAL) { |
b71d1d42 | 227 | const struct ipv6hdr *hdr; |
1da177e4 | 228 | |
9fb9cbb1 YK |
229 | /* Free reference early: we don't need it any more, |
230 | and it may hold ip_conntrack module loaded | |
231 | indefinitely. */ | |
232 | nf_reset(skb); | |
233 | ||
d56f90a7 | 234 | skb_postpull_rcsum(skb, skb_network_header(skb), |
cfe1fc77 | 235 | skb_network_header_len(skb)); |
0660e03f | 236 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
237 | if (ipv6_addr_is_multicast(&hdr->daddr) && |
238 | !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, | |
239 | &hdr->saddr) && | |
daad1512 | 240 | !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb))) |
1da177e4 LT |
241 | goto discard; |
242 | } | |
243 | if (!(ipprot->flags & INET6_PROTO_NOPOLICY) && | |
1ab1457c | 244 | !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) |
1da177e4 | 245 | goto discard; |
1ab1457c | 246 | |
e5bbef20 | 247 | ret = ipprot->handler(skb); |
1da177e4 LT |
248 | if (ret > 0) |
249 | goto resubmit; | |
250 | else if (ret == 0) | |
483a47d2 | 251 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS); |
1da177e4 | 252 | } else { |
69d6da0b | 253 | if (!raw) { |
1da177e4 | 254 | if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
483a47d2 DL |
255 | IP6_INC_STATS_BH(net, idev, |
256 | IPSTATS_MIB_INUNKNOWNPROTOS); | |
fad87aca | 257 | icmpv6_send(skb, ICMPV6_PARAMPROB, |
3ffe533c | 258 | ICMPV6_UNK_NEXTHDR, nhoff); |
1da177e4 | 259 | } |
d8c6f4b9 NH |
260 | kfree_skb(skb); |
261 | } else { | |
483a47d2 | 262 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS); |
d8c6f4b9 NH |
263 | consume_skb(skb); |
264 | } | |
1da177e4 LT |
265 | } |
266 | rcu_read_unlock(); | |
267 | return 0; | |
268 | ||
269 | discard: | |
483a47d2 | 270 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS); |
1da177e4 LT |
271 | rcu_read_unlock(); |
272 | kfree_skb(skb); | |
273 | return 0; | |
274 | } | |
275 | ||
276 | ||
277 | int ip6_input(struct sk_buff *skb) | |
278 | { | |
b2e0b385 | 279 | return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, skb, skb->dev, NULL, |
6e23ae2a | 280 | ip6_input_finish); |
1da177e4 LT |
281 | } |
282 | ||
283 | int ip6_mc_input(struct sk_buff *skb) | |
284 | { | |
b71d1d42 | 285 | const struct ipv6hdr *hdr; |
a50feda5 | 286 | bool deliver; |
1da177e4 | 287 | |
adf30907 ED |
288 | IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev), |
289 | ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST, | |
edf391ff | 290 | skb->len); |
1da177e4 | 291 | |
0660e03f | 292 | hdr = ipv6_hdr(skb); |
4c7966b8 | 293 | deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL); |
1da177e4 | 294 | |
7bc570c8 | 295 | #ifdef CONFIG_IPV6_MROUTE |
1da177e4 | 296 | /* |
7bc570c8 | 297 | * IPv6 multicast router mode is now supported ;) |
1da177e4 | 298 | */ |
53b7997f | 299 | if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding && |
ddf64354 HFS |
300 | !(ipv6_addr_type(&hdr->daddr) & |
301 | (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) && | |
7bc570c8 YH |
302 | likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) { |
303 | /* | |
304 | * Okay, we try to forward - split and duplicate | |
305 | * packets. | |
306 | */ | |
307 | struct sk_buff *skb2; | |
308 | struct inet6_skb_parm *opt = IP6CB(skb); | |
309 | ||
310 | /* Check for MLD */ | |
dd3332bf | 311 | if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) { |
7bc570c8 | 312 | /* Check if this is a mld message */ |
7bc570c8 | 313 | u8 nexthdr = hdr->nexthdr; |
75f2811c | 314 | __be16 frag_off; |
7bc570c8 YH |
315 | int offset; |
316 | ||
317 | /* Check if the value of Router Alert | |
318 | * is for MLD (0x0000). | |
319 | */ | |
dd3332bf | 320 | if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) { |
a50feda5 | 321 | deliver = false; |
aba6096b | 322 | |
7bc570c8 YH |
323 | if (!ipv6_ext_hdr(nexthdr)) { |
324 | /* BUG */ | |
aba6096b | 325 | goto out; |
7bc570c8 YH |
326 | } |
327 | offset = ipv6_skip_exthdr(skb, sizeof(*hdr), | |
75f2811c | 328 | &nexthdr, &frag_off); |
7bc570c8 | 329 | if (offset < 0) |
aba6096b | 330 | goto out; |
7bc570c8 | 331 | |
daad1512 | 332 | if (!ipv6_is_mld(skb, nexthdr, offset)) |
aba6096b | 333 | goto out; |
7bc570c8 | 334 | |
daad1512 | 335 | deliver = true; |
7bc570c8 YH |
336 | } |
337 | /* unknown RA - process it normally */ | |
338 | } | |
1da177e4 | 339 | |
7bc570c8 YH |
340 | if (deliver) |
341 | skb2 = skb_clone(skb, GFP_ATOMIC); | |
342 | else { | |
343 | skb2 = skb; | |
344 | skb = NULL; | |
345 | } | |
1ab1457c | 346 | |
7bc570c8 | 347 | if (skb2) { |
7bc570c8 | 348 | ip6_mr_input(skb2); |
1da177e4 LT |
349 | } |
350 | } | |
7bc570c8 | 351 | out: |
aba6096b YH |
352 | #endif |
353 | if (likely(deliver)) | |
1da177e4 | 354 | ip6_input(skb); |
aba6096b YH |
355 | else { |
356 | /* discard */ | |
357 | kfree_skb(skb); | |
1da177e4 | 358 | } |
1da177e4 LT |
359 | |
360 | return 0; | |
361 | } |