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 | * | |
18 | * Mitsuru KANDA @USAGI and | |
19 | * YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs(). | |
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> | |
47 | ||
48 | ||
49 | ||
c7109986 | 50 | int ip6_rcv_finish(struct sk_buff *skb) |
1da177e4 | 51 | { |
c7109986 ED |
52 | if (sysctl_ip_early_demux && !skb_dst(skb)) { |
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; |
1da177e4 | 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 | ||
f630e43a YH |
112 | /* |
113 | * RFC4291 2.5.3 | |
114 | * A packet received on an interface with a destination address | |
115 | * of loopback must be dropped. | |
116 | */ | |
117 | if (!(dev->flags & IFF_LOOPBACK) && | |
118 | ipv6_addr_loopback(&hdr->daddr)) | |
119 | goto err; | |
120 | ||
1c4a154e HFS |
121 | /* RFC4291 Errata ID: 3480 |
122 | * Interface-Local scope spans only a single interface on a | |
123 | * node and is useful only for loopback transmission of | |
124 | * multicast. Packets with interface-local scope received | |
125 | * from another node must be discarded. | |
126 | */ | |
127 | if (!(skb->pkt_type == PACKET_LOOPBACK || | |
128 | dev->flags & IFF_LOOPBACK) && | |
129 | ipv6_addr_is_multicast(&hdr->daddr) && | |
130 | IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1) | |
131 | goto err; | |
132 | ||
20314092 HFS |
133 | /* RFC4291 2.7 |
134 | * Nodes must not originate a packet to a multicast address whose scope | |
135 | * field contains the reserved value 0; if such a packet is received, it | |
136 | * must be silently dropped. | |
137 | */ | |
138 | if (ipv6_addr_is_multicast(&hdr->daddr) && | |
139 | IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0) | |
140 | goto err; | |
141 | ||
c457338d BH |
142 | /* |
143 | * RFC4291 2.7 | |
144 | * Multicast addresses must not be used as source addresses in IPv6 | |
145 | * packets or appear in any Routing header. | |
146 | */ | |
147 | if (ipv6_addr_is_multicast(&hdr->saddr)) | |
148 | goto err; | |
149 | ||
b0e380b1 | 150 | skb->transport_header = skb->network_header + sizeof(*hdr); |
951dbc8a PM |
151 | IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr); |
152 | ||
1da177e4 LT |
153 | pkt_len = ntohs(hdr->payload_len); |
154 | ||
155 | /* pkt_len may be zero if Jumbo payload option is present */ | |
156 | if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) { | |
60e5c166 | 157 | if (pkt_len + sizeof(struct ipv6hdr) > skb->len) { |
483a47d2 DL |
158 | IP6_INC_STATS_BH(net, |
159 | idev, IPSTATS_MIB_INTRUNCATEDPKTS); | |
60e5c166 MC |
160 | goto drop; |
161 | } | |
1da177e4 | 162 | if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) { |
483a47d2 | 163 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS); |
1da177e4 LT |
164 | goto drop; |
165 | } | |
0660e03f | 166 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
167 | } |
168 | ||
169 | if (hdr->nexthdr == NEXTHDR_HOP) { | |
e5bbef20 | 170 | if (ipv6_parse_hopopts(skb) < 0) { |
483a47d2 | 171 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS); |
a11d206d | 172 | rcu_read_unlock(); |
5c91face | 173 | return NET_RX_DROP; |
1da177e4 | 174 | } |
1da177e4 LT |
175 | } |
176 | ||
a11d206d YH |
177 | rcu_read_unlock(); |
178 | ||
71f9dacd HX |
179 | /* Must drop socket now because of tproxy. */ |
180 | skb_orphan(skb); | |
181 | ||
b2e0b385 | 182 | return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, dev, NULL, |
6e23ae2a | 183 | ip6_rcv_finish); |
1da177e4 | 184 | err: |
483a47d2 | 185 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS); |
1da177e4 | 186 | drop: |
a11d206d | 187 | rcu_read_unlock(); |
1da177e4 | 188 | kfree_skb(skb); |
5c91face | 189 | return NET_RX_DROP; |
1da177e4 LT |
190 | } |
191 | ||
192 | /* | |
193 | * Deliver the packet to the host | |
194 | */ | |
195 | ||
196 | ||
ad643a79 | 197 | static int ip6_input_finish(struct sk_buff *skb) |
1da177e4 | 198 | { |
f9242b6b | 199 | struct net *net = dev_net(skb_dst(skb)->dev); |
41135cc8 | 200 | const struct inet6_protocol *ipprot; |
f9242b6b | 201 | struct inet6_dev *idev; |
1da177e4 | 202 | unsigned int nhoff; |
a50feda5 ED |
203 | int nexthdr; |
204 | bool raw; | |
1da177e4 | 205 | |
1da177e4 LT |
206 | /* |
207 | * Parse extension headers | |
208 | */ | |
209 | ||
1da177e4 LT |
210 | rcu_read_lock(); |
211 | resubmit: | |
adf30907 | 212 | idev = ip6_dst_idev(skb_dst(skb)); |
ea2ae17d | 213 | if (!pskb_pull(skb, skb_transport_offset(skb))) |
1da177e4 | 214 | goto discard; |
951dbc8a | 215 | nhoff = IP6CB(skb)->nhoff; |
d56f90a7 | 216 | nexthdr = skb_network_header(skb)[nhoff]; |
1da177e4 | 217 | |
69d6da0b | 218 | raw = raw6_local_deliver(skb, nexthdr); |
f9242b6b | 219 | if ((ipprot = rcu_dereference(inet6_protos[nexthdr])) != NULL) { |
1da177e4 | 220 | int ret; |
1ab1457c | 221 | |
1da177e4 | 222 | if (ipprot->flags & INET6_PROTO_FINAL) { |
b71d1d42 | 223 | const struct ipv6hdr *hdr; |
1da177e4 | 224 | |
9fb9cbb1 YK |
225 | /* Free reference early: we don't need it any more, |
226 | and it may hold ip_conntrack module loaded | |
227 | indefinitely. */ | |
228 | nf_reset(skb); | |
229 | ||
d56f90a7 | 230 | skb_postpull_rcsum(skb, skb_network_header(skb), |
cfe1fc77 | 231 | skb_network_header_len(skb)); |
0660e03f | 232 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
233 | if (ipv6_addr_is_multicast(&hdr->daddr) && |
234 | !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, | |
235 | &hdr->saddr) && | |
daad1512 | 236 | !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb))) |
1da177e4 LT |
237 | goto discard; |
238 | } | |
239 | if (!(ipprot->flags & INET6_PROTO_NOPOLICY) && | |
1ab1457c | 240 | !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) |
1da177e4 | 241 | goto discard; |
1ab1457c | 242 | |
e5bbef20 | 243 | ret = ipprot->handler(skb); |
1da177e4 LT |
244 | if (ret > 0) |
245 | goto resubmit; | |
246 | else if (ret == 0) | |
483a47d2 | 247 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS); |
1da177e4 | 248 | } else { |
69d6da0b | 249 | if (!raw) { |
1da177e4 | 250 | if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
483a47d2 DL |
251 | IP6_INC_STATS_BH(net, idev, |
252 | IPSTATS_MIB_INUNKNOWNPROTOS); | |
fad87aca | 253 | icmpv6_send(skb, ICMPV6_PARAMPROB, |
3ffe533c | 254 | ICMPV6_UNK_NEXTHDR, nhoff); |
1da177e4 | 255 | } |
d8c6f4b9 NH |
256 | kfree_skb(skb); |
257 | } else { | |
483a47d2 | 258 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS); |
d8c6f4b9 NH |
259 | consume_skb(skb); |
260 | } | |
1da177e4 LT |
261 | } |
262 | rcu_read_unlock(); | |
263 | return 0; | |
264 | ||
265 | discard: | |
483a47d2 | 266 | IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS); |
1da177e4 LT |
267 | rcu_read_unlock(); |
268 | kfree_skb(skb); | |
269 | return 0; | |
270 | } | |
271 | ||
272 | ||
273 | int ip6_input(struct sk_buff *skb) | |
274 | { | |
b2e0b385 | 275 | return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, skb, skb->dev, NULL, |
6e23ae2a | 276 | ip6_input_finish); |
1da177e4 LT |
277 | } |
278 | ||
279 | int ip6_mc_input(struct sk_buff *skb) | |
280 | { | |
b71d1d42 | 281 | const struct ipv6hdr *hdr; |
a50feda5 | 282 | bool deliver; |
1da177e4 | 283 | |
adf30907 ED |
284 | IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev), |
285 | ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST, | |
edf391ff | 286 | skb->len); |
1da177e4 | 287 | |
0660e03f | 288 | hdr = ipv6_hdr(skb); |
4c7966b8 | 289 | deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL); |
1da177e4 | 290 | |
7bc570c8 | 291 | #ifdef CONFIG_IPV6_MROUTE |
1da177e4 | 292 | /* |
7bc570c8 | 293 | * IPv6 multicast router mode is now supported ;) |
1da177e4 | 294 | */ |
53b7997f | 295 | if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding && |
ddf64354 HFS |
296 | !(ipv6_addr_type(&hdr->daddr) & |
297 | (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) && | |
7bc570c8 YH |
298 | likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) { |
299 | /* | |
300 | * Okay, we try to forward - split and duplicate | |
301 | * packets. | |
302 | */ | |
303 | struct sk_buff *skb2; | |
304 | struct inet6_skb_parm *opt = IP6CB(skb); | |
305 | ||
306 | /* Check for MLD */ | |
dd3332bf | 307 | if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) { |
7bc570c8 | 308 | /* Check if this is a mld message */ |
7bc570c8 | 309 | u8 nexthdr = hdr->nexthdr; |
75f2811c | 310 | __be16 frag_off; |
7bc570c8 YH |
311 | int offset; |
312 | ||
313 | /* Check if the value of Router Alert | |
314 | * is for MLD (0x0000). | |
315 | */ | |
dd3332bf | 316 | if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) { |
a50feda5 | 317 | deliver = false; |
aba6096b | 318 | |
7bc570c8 YH |
319 | if (!ipv6_ext_hdr(nexthdr)) { |
320 | /* BUG */ | |
aba6096b | 321 | goto out; |
7bc570c8 YH |
322 | } |
323 | offset = ipv6_skip_exthdr(skb, sizeof(*hdr), | |
75f2811c | 324 | &nexthdr, &frag_off); |
7bc570c8 | 325 | if (offset < 0) |
aba6096b | 326 | goto out; |
7bc570c8 | 327 | |
daad1512 | 328 | if (!ipv6_is_mld(skb, nexthdr, offset)) |
aba6096b | 329 | goto out; |
7bc570c8 | 330 | |
daad1512 | 331 | deliver = true; |
7bc570c8 YH |
332 | } |
333 | /* unknown RA - process it normally */ | |
334 | } | |
1da177e4 | 335 | |
7bc570c8 YH |
336 | if (deliver) |
337 | skb2 = skb_clone(skb, GFP_ATOMIC); | |
338 | else { | |
339 | skb2 = skb; | |
340 | skb = NULL; | |
341 | } | |
1ab1457c | 342 | |
7bc570c8 | 343 | if (skb2) { |
7bc570c8 | 344 | ip6_mr_input(skb2); |
1da177e4 LT |
345 | } |
346 | } | |
7bc570c8 | 347 | out: |
aba6096b YH |
348 | #endif |
349 | if (likely(deliver)) | |
1da177e4 | 350 | ip6_input(skb); |
aba6096b YH |
351 | else { |
352 | /* discard */ | |
353 | kfree_skb(skb); | |
1da177e4 | 354 | } |
1da177e4 LT |
355 | |
356 | return 0; | |
357 | } |