Loading...
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 * 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>
26#include <linux/net.h>
27#include <linux/netdevice.h>
28#include <linux/in6.h>
29#include <linux/icmpv6.h>
30#include <linux/mroute6.h>
31#include <linux/slab.h>
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
50inline int ip6_rcv_finish( struct sk_buff *skb)
51{
52 if (skb_dst(skb) == NULL)
53 ip6_route_input(skb);
54
55 return dst_input(skb);
56}
57
58int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
59{
60 const struct ipv6hdr *hdr;
61 u32 pkt_len;
62 struct inet6_dev *idev;
63 struct net *net = dev_net(skb->dev);
64
65 if (skb->pkt_type == PACKET_OTHERHOST) {
66 kfree_skb(skb);
67 return NET_RX_DROP;
68 }
69
70 rcu_read_lock();
71
72 idev = __in6_dev_get(skb->dev);
73
74 IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len);
75
76 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
77 !idev || unlikely(idev->cnf.disable_ipv6)) {
78 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
79 goto drop;
80 }
81
82 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
83
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
90 * via the loopback interface (lo) here; skb->dev = loopback_dev.
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 */
95 IP6CB(skb)->iif = skb_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
96
97 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
98 goto err;
99
100 hdr = ipv6_hdr(skb);
101
102 if (hdr->version != 6)
103 goto err;
104
105 /*
106 * RFC4291 2.5.3
107 * A packet received on an interface with a destination address
108 * of loopback must be dropped.
109 */
110 if (!(dev->flags & IFF_LOOPBACK) &&
111 ipv6_addr_loopback(&hdr->daddr))
112 goto err;
113
114 skb->transport_header = skb->network_header + sizeof(*hdr);
115 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
116
117 pkt_len = ntohs(hdr->payload_len);
118
119 /* pkt_len may be zero if Jumbo payload option is present */
120 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
121 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
122 IP6_INC_STATS_BH(net,
123 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
124 goto drop;
125 }
126 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
127 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
128 goto drop;
129 }
130 hdr = ipv6_hdr(skb);
131 }
132
133 if (hdr->nexthdr == NEXTHDR_HOP) {
134 if (ipv6_parse_hopopts(skb) < 0) {
135 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
136 rcu_read_unlock();
137 return NET_RX_DROP;
138 }
139 }
140
141 rcu_read_unlock();
142
143 /* Must drop socket now because of tproxy. */
144 skb_orphan(skb);
145
146 return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, dev, NULL,
147 ip6_rcv_finish);
148err:
149 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
150drop:
151 rcu_read_unlock();
152 kfree_skb(skb);
153 return NET_RX_DROP;
154}
155
156/*
157 * Deliver the packet to the host
158 */
159
160
161static int ip6_input_finish(struct sk_buff *skb)
162{
163 const struct inet6_protocol *ipprot;
164 unsigned int nhoff;
165 int nexthdr, raw;
166 u8 hash;
167 struct inet6_dev *idev;
168 struct net *net = dev_net(skb_dst(skb)->dev);
169
170 /*
171 * Parse extension headers
172 */
173
174 rcu_read_lock();
175resubmit:
176 idev = ip6_dst_idev(skb_dst(skb));
177 if (!pskb_pull(skb, skb_transport_offset(skb)))
178 goto discard;
179 nhoff = IP6CB(skb)->nhoff;
180 nexthdr = skb_network_header(skb)[nhoff];
181
182 raw = raw6_local_deliver(skb, nexthdr);
183
184 hash = nexthdr & (MAX_INET_PROTOS - 1);
185 if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
186 int ret;
187
188 if (ipprot->flags & INET6_PROTO_FINAL) {
189 const struct ipv6hdr *hdr;
190
191 /* Free reference early: we don't need it any more,
192 and it may hold ip_conntrack module loaded
193 indefinitely. */
194 nf_reset(skb);
195
196 skb_postpull_rcsum(skb, skb_network_header(skb),
197 skb_network_header_len(skb));
198 hdr = ipv6_hdr(skb);
199 if (ipv6_addr_is_multicast(&hdr->daddr) &&
200 !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
201 &hdr->saddr) &&
202 !ipv6_is_mld(skb, nexthdr))
203 goto discard;
204 }
205 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
206 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
207 goto discard;
208
209 ret = ipprot->handler(skb);
210 if (ret > 0)
211 goto resubmit;
212 else if (ret == 0)
213 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
214 } else {
215 if (!raw) {
216 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
217 IP6_INC_STATS_BH(net, idev,
218 IPSTATS_MIB_INUNKNOWNPROTOS);
219 icmpv6_send(skb, ICMPV6_PARAMPROB,
220 ICMPV6_UNK_NEXTHDR, nhoff);
221 }
222 } else
223 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
224 kfree_skb(skb);
225 }
226 rcu_read_unlock();
227 return 0;
228
229discard:
230 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
231 rcu_read_unlock();
232 kfree_skb(skb);
233 return 0;
234}
235
236
237int ip6_input(struct sk_buff *skb)
238{
239 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
240 ip6_input_finish);
241}
242
243int ip6_mc_input(struct sk_buff *skb)
244{
245 const struct ipv6hdr *hdr;
246 int deliver;
247
248 IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev),
249 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
250 skb->len);
251
252 hdr = ipv6_hdr(skb);
253 deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
254
255#ifdef CONFIG_IPV6_MROUTE
256 /*
257 * IPv6 multicast router mode is now supported ;)
258 */
259 if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
260 !(ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) &&
261 likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
262 /*
263 * Okay, we try to forward - split and duplicate
264 * packets.
265 */
266 struct sk_buff *skb2;
267 struct inet6_skb_parm *opt = IP6CB(skb);
268
269 /* Check for MLD */
270 if (unlikely(opt->ra)) {
271 /* Check if this is a mld message */
272 u8 *ptr = skb_network_header(skb) + opt->ra;
273 struct icmp6hdr *icmp6;
274 u8 nexthdr = hdr->nexthdr;
275 int offset;
276
277 /* Check if the value of Router Alert
278 * is for MLD (0x0000).
279 */
280 if ((ptr[2] | ptr[3]) == 0) {
281 deliver = 0;
282
283 if (!ipv6_ext_hdr(nexthdr)) {
284 /* BUG */
285 goto out;
286 }
287 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
288 &nexthdr);
289 if (offset < 0)
290 goto out;
291
292 if (nexthdr != IPPROTO_ICMPV6)
293 goto out;
294
295 if (!pskb_may_pull(skb, (skb_network_header(skb) +
296 offset + 1 - skb->data)))
297 goto out;
298
299 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
300
301 switch (icmp6->icmp6_type) {
302 case ICMPV6_MGM_QUERY:
303 case ICMPV6_MGM_REPORT:
304 case ICMPV6_MGM_REDUCTION:
305 case ICMPV6_MLD2_REPORT:
306 deliver = 1;
307 break;
308 }
309 goto out;
310 }
311 /* unknown RA - process it normally */
312 }
313
314 if (deliver)
315 skb2 = skb_clone(skb, GFP_ATOMIC);
316 else {
317 skb2 = skb;
318 skb = NULL;
319 }
320
321 if (skb2) {
322 ip6_mr_input(skb2);
323 }
324 }
325out:
326#endif
327 if (likely(deliver))
328 ip6_input(skb);
329 else {
330 /* discard */
331 kfree_skb(skb);
332 }
333
334 return 0;
335}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * IPv6 input
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 * Ian P. Morris <I.P.Morris@soton.ac.uk>
9 *
10 * Based in linux/net/ipv4/ip_input.c
11 */
12/* Changes
13 *
14 * Mitsuru KANDA @USAGI and
15 * YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
16 */
17
18#include <linux/errno.h>
19#include <linux/types.h>
20#include <linux/socket.h>
21#include <linux/sockios.h>
22#include <linux/net.h>
23#include <linux/netdevice.h>
24#include <linux/in6.h>
25#include <linux/icmpv6.h>
26#include <linux/mroute6.h>
27#include <linux/slab.h>
28#include <linux/indirect_call_wrapper.h>
29
30#include <linux/netfilter.h>
31#include <linux/netfilter_ipv6.h>
32
33#include <net/sock.h>
34#include <net/snmp.h>
35
36#include <net/ipv6.h>
37#include <net/protocol.h>
38#include <net/transp_v6.h>
39#include <net/rawv6.h>
40#include <net/ndisc.h>
41#include <net/ip6_route.h>
42#include <net/addrconf.h>
43#include <net/xfrm.h>
44#include <net/inet_ecn.h>
45#include <net/dst_metadata.h>
46
47INDIRECT_CALLABLE_DECLARE(void udp_v6_early_demux(struct sk_buff *));
48INDIRECT_CALLABLE_DECLARE(void tcp_v6_early_demux(struct sk_buff *));
49static void ip6_rcv_finish_core(struct net *net, struct sock *sk,
50 struct sk_buff *skb)
51{
52 void (*edemux)(struct sk_buff *skb);
53
54 if (net->ipv4.sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) {
55 const struct inet6_protocol *ipprot;
56
57 ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
58 if (ipprot && (edemux = READ_ONCE(ipprot->early_demux)))
59 INDIRECT_CALL_2(edemux, tcp_v6_early_demux,
60 udp_v6_early_demux, skb);
61 }
62 if (!skb_valid_dst(skb))
63 ip6_route_input(skb);
64}
65
66int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
67{
68 /* if ingress device is enslaved to an L3 master device pass the
69 * skb to its handler for processing
70 */
71 skb = l3mdev_ip6_rcv(skb);
72 if (!skb)
73 return NET_RX_SUCCESS;
74 ip6_rcv_finish_core(net, sk, skb);
75
76 return dst_input(skb);
77}
78
79static void ip6_sublist_rcv_finish(struct list_head *head)
80{
81 struct sk_buff *skb, *next;
82
83 list_for_each_entry_safe(skb, next, head, list) {
84 skb_list_del_init(skb);
85 dst_input(skb);
86 }
87}
88
89static bool ip6_can_use_hint(const struct sk_buff *skb,
90 const struct sk_buff *hint)
91{
92 return hint && !skb_dst(skb) &&
93 ipv6_addr_equal(&ipv6_hdr(hint)->daddr, &ipv6_hdr(skb)->daddr);
94}
95
96static struct sk_buff *ip6_extract_route_hint(const struct net *net,
97 struct sk_buff *skb)
98{
99 if (fib6_routes_require_src(net) || fib6_has_custom_rules(net))
100 return NULL;
101
102 return skb;
103}
104
105static void ip6_list_rcv_finish(struct net *net, struct sock *sk,
106 struct list_head *head)
107{
108 struct sk_buff *skb, *next, *hint = NULL;
109 struct dst_entry *curr_dst = NULL;
110 struct list_head sublist;
111
112 INIT_LIST_HEAD(&sublist);
113 list_for_each_entry_safe(skb, next, head, list) {
114 struct dst_entry *dst;
115
116 skb_list_del_init(skb);
117 /* if ingress device is enslaved to an L3 master device pass the
118 * skb to its handler for processing
119 */
120 skb = l3mdev_ip6_rcv(skb);
121 if (!skb)
122 continue;
123
124 if (ip6_can_use_hint(skb, hint))
125 skb_dst_copy(skb, hint);
126 else
127 ip6_rcv_finish_core(net, sk, skb);
128 dst = skb_dst(skb);
129 if (curr_dst != dst) {
130 hint = ip6_extract_route_hint(net, skb);
131
132 /* dispatch old sublist */
133 if (!list_empty(&sublist))
134 ip6_sublist_rcv_finish(&sublist);
135 /* start new sublist */
136 INIT_LIST_HEAD(&sublist);
137 curr_dst = dst;
138 }
139 list_add_tail(&skb->list, &sublist);
140 }
141 /* dispatch final sublist */
142 ip6_sublist_rcv_finish(&sublist);
143}
144
145static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev,
146 struct net *net)
147{
148 const struct ipv6hdr *hdr;
149 u32 pkt_len;
150 struct inet6_dev *idev;
151
152 if (skb->pkt_type == PACKET_OTHERHOST) {
153 kfree_skb(skb);
154 return NULL;
155 }
156
157 rcu_read_lock();
158
159 idev = __in6_dev_get(skb->dev);
160
161 __IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_IN, skb->len);
162
163 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
164 !idev || unlikely(idev->cnf.disable_ipv6)) {
165 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
166 goto drop;
167 }
168
169 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
170
171 /*
172 * Store incoming device index. When the packet will
173 * be queued, we cannot refer to skb->dev anymore.
174 *
175 * BTW, when we send a packet for our own local address on a
176 * non-loopback interface (e.g. ethX), it is being delivered
177 * via the loopback interface (lo) here; skb->dev = loopback_dev.
178 * It, however, should be considered as if it is being
179 * arrived via the sending interface (ethX), because of the
180 * nature of scoping architecture. --yoshfuji
181 */
182 IP6CB(skb)->iif = skb_valid_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
183
184 if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
185 goto err;
186
187 hdr = ipv6_hdr(skb);
188
189 if (hdr->version != 6)
190 goto err;
191
192 __IP6_ADD_STATS(net, idev,
193 IPSTATS_MIB_NOECTPKTS +
194 (ipv6_get_dsfield(hdr) & INET_ECN_MASK),
195 max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs));
196 /*
197 * RFC4291 2.5.3
198 * The loopback address must not be used as the source address in IPv6
199 * packets that are sent outside of a single node. [..]
200 * A packet received on an interface with a destination address
201 * of loopback must be dropped.
202 */
203 if ((ipv6_addr_loopback(&hdr->saddr) ||
204 ipv6_addr_loopback(&hdr->daddr)) &&
205 !(dev->flags & IFF_LOOPBACK) &&
206 !netif_is_l3_master(dev))
207 goto err;
208
209 /* RFC4291 Errata ID: 3480
210 * Interface-Local scope spans only a single interface on a
211 * node and is useful only for loopback transmission of
212 * multicast. Packets with interface-local scope received
213 * from another node must be discarded.
214 */
215 if (!(skb->pkt_type == PACKET_LOOPBACK ||
216 dev->flags & IFF_LOOPBACK) &&
217 ipv6_addr_is_multicast(&hdr->daddr) &&
218 IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1)
219 goto err;
220
221 /* If enabled, drop unicast packets that were encapsulated in link-layer
222 * multicast or broadcast to protected against the so-called "hole-196"
223 * attack in 802.11 wireless.
224 */
225 if (!ipv6_addr_is_multicast(&hdr->daddr) &&
226 (skb->pkt_type == PACKET_BROADCAST ||
227 skb->pkt_type == PACKET_MULTICAST) &&
228 idev->cnf.drop_unicast_in_l2_multicast)
229 goto err;
230
231 /* RFC4291 2.7
232 * Nodes must not originate a packet to a multicast address whose scope
233 * field contains the reserved value 0; if such a packet is received, it
234 * must be silently dropped.
235 */
236 if (ipv6_addr_is_multicast(&hdr->daddr) &&
237 IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0)
238 goto err;
239
240 /*
241 * RFC4291 2.7
242 * Multicast addresses must not be used as source addresses in IPv6
243 * packets or appear in any Routing header.
244 */
245 if (ipv6_addr_is_multicast(&hdr->saddr))
246 goto err;
247
248 /* While RFC4291 is not explicit about v4mapped addresses
249 * in IPv6 headers, it seems clear linux dual-stack
250 * model can not deal properly with these.
251 * Security models could be fooled by ::ffff:127.0.0.1 for example.
252 *
253 * https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02
254 */
255 if (ipv6_addr_v4mapped(&hdr->saddr))
256 goto err;
257
258 skb->transport_header = skb->network_header + sizeof(*hdr);
259 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
260
261 pkt_len = ntohs(hdr->payload_len);
262
263 /* pkt_len may be zero if Jumbo payload option is present */
264 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
265 if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
266 __IP6_INC_STATS(net,
267 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
268 goto drop;
269 }
270 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
271 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
272 goto drop;
273 }
274 hdr = ipv6_hdr(skb);
275 }
276
277 if (hdr->nexthdr == NEXTHDR_HOP) {
278 if (ipv6_parse_hopopts(skb) < 0) {
279 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
280 rcu_read_unlock();
281 return NULL;
282 }
283 }
284
285 rcu_read_unlock();
286
287 /* Must drop socket now because of tproxy. */
288 if (!skb_sk_is_prefetched(skb))
289 skb_orphan(skb);
290
291 return skb;
292err:
293 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
294drop:
295 rcu_read_unlock();
296 kfree_skb(skb);
297 return NULL;
298}
299
300int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
301{
302 struct net *net = dev_net(skb->dev);
303
304 skb = ip6_rcv_core(skb, dev, net);
305 if (skb == NULL)
306 return NET_RX_DROP;
307 return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
308 net, NULL, skb, dev, NULL,
309 ip6_rcv_finish);
310}
311
312static void ip6_sublist_rcv(struct list_head *head, struct net_device *dev,
313 struct net *net)
314{
315 NF_HOOK_LIST(NFPROTO_IPV6, NF_INET_PRE_ROUTING, net, NULL,
316 head, dev, NULL, ip6_rcv_finish);
317 ip6_list_rcv_finish(net, NULL, head);
318}
319
320/* Receive a list of IPv6 packets */
321void ipv6_list_rcv(struct list_head *head, struct packet_type *pt,
322 struct net_device *orig_dev)
323{
324 struct net_device *curr_dev = NULL;
325 struct net *curr_net = NULL;
326 struct sk_buff *skb, *next;
327 struct list_head sublist;
328
329 INIT_LIST_HEAD(&sublist);
330 list_for_each_entry_safe(skb, next, head, list) {
331 struct net_device *dev = skb->dev;
332 struct net *net = dev_net(dev);
333
334 skb_list_del_init(skb);
335 skb = ip6_rcv_core(skb, dev, net);
336 if (skb == NULL)
337 continue;
338
339 if (curr_dev != dev || curr_net != net) {
340 /* dispatch old sublist */
341 if (!list_empty(&sublist))
342 ip6_sublist_rcv(&sublist, curr_dev, curr_net);
343 /* start new sublist */
344 INIT_LIST_HEAD(&sublist);
345 curr_dev = dev;
346 curr_net = net;
347 }
348 list_add_tail(&skb->list, &sublist);
349 }
350 /* dispatch final sublist */
351 if (!list_empty(&sublist))
352 ip6_sublist_rcv(&sublist, curr_dev, curr_net);
353}
354
355INDIRECT_CALLABLE_DECLARE(int udpv6_rcv(struct sk_buff *));
356INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *));
357
358/*
359 * Deliver the packet to the host
360 */
361void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr,
362 bool have_final)
363{
364 const struct inet6_protocol *ipprot;
365 struct inet6_dev *idev;
366 unsigned int nhoff;
367 bool raw;
368
369 /*
370 * Parse extension headers
371 */
372
373resubmit:
374 idev = ip6_dst_idev(skb_dst(skb));
375 nhoff = IP6CB(skb)->nhoff;
376 if (!have_final) {
377 if (!pskb_pull(skb, skb_transport_offset(skb)))
378 goto discard;
379 nexthdr = skb_network_header(skb)[nhoff];
380 }
381
382resubmit_final:
383 raw = raw6_local_deliver(skb, nexthdr);
384 ipprot = rcu_dereference(inet6_protos[nexthdr]);
385 if (ipprot) {
386 int ret;
387
388 if (have_final) {
389 if (!(ipprot->flags & INET6_PROTO_FINAL)) {
390 /* Once we've seen a final protocol don't
391 * allow encapsulation on any non-final
392 * ones. This allows foo in UDP encapsulation
393 * to work.
394 */
395 goto discard;
396 }
397 } else if (ipprot->flags & INET6_PROTO_FINAL) {
398 const struct ipv6hdr *hdr;
399 int sdif = inet6_sdif(skb);
400 struct net_device *dev;
401
402 /* Only do this once for first final protocol */
403 have_final = true;
404
405 /* Free reference early: we don't need it any more,
406 and it may hold ip_conntrack module loaded
407 indefinitely. */
408 nf_reset_ct(skb);
409
410 skb_postpull_rcsum(skb, skb_network_header(skb),
411 skb_network_header_len(skb));
412 hdr = ipv6_hdr(skb);
413
414 /* skb->dev passed may be master dev for vrfs. */
415 if (sdif) {
416 dev = dev_get_by_index_rcu(net, sdif);
417 if (!dev)
418 goto discard;
419 } else {
420 dev = skb->dev;
421 }
422
423 if (ipv6_addr_is_multicast(&hdr->daddr) &&
424 !ipv6_chk_mcast_addr(dev, &hdr->daddr,
425 &hdr->saddr) &&
426 !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
427 goto discard;
428 }
429 if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
430 !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
431 goto discard;
432
433 ret = INDIRECT_CALL_2(ipprot->handler, tcp_v6_rcv, udpv6_rcv,
434 skb);
435 if (ret > 0) {
436 if (ipprot->flags & INET6_PROTO_FINAL) {
437 /* Not an extension header, most likely UDP
438 * encapsulation. Use return value as nexthdr
439 * protocol not nhoff (which presumably is
440 * not set by handler).
441 */
442 nexthdr = ret;
443 goto resubmit_final;
444 } else {
445 goto resubmit;
446 }
447 } else if (ret == 0) {
448 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
449 }
450 } else {
451 if (!raw) {
452 if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
453 __IP6_INC_STATS(net, idev,
454 IPSTATS_MIB_INUNKNOWNPROTOS);
455 icmpv6_send(skb, ICMPV6_PARAMPROB,
456 ICMPV6_UNK_NEXTHDR, nhoff);
457 }
458 kfree_skb(skb);
459 } else {
460 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
461 consume_skb(skb);
462 }
463 }
464 return;
465
466discard:
467 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
468 kfree_skb(skb);
469}
470
471static int ip6_input_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
472{
473 rcu_read_lock();
474 ip6_protocol_deliver_rcu(net, skb, 0, false);
475 rcu_read_unlock();
476
477 return 0;
478}
479
480
481int ip6_input(struct sk_buff *skb)
482{
483 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN,
484 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
485 ip6_input_finish);
486}
487EXPORT_SYMBOL_GPL(ip6_input);
488
489int ip6_mc_input(struct sk_buff *skb)
490{
491 int sdif = inet6_sdif(skb);
492 const struct ipv6hdr *hdr;
493 struct net_device *dev;
494 bool deliver;
495
496 __IP6_UPD_PO_STATS(dev_net(skb_dst(skb)->dev),
497 __in6_dev_get_safely(skb->dev), IPSTATS_MIB_INMCAST,
498 skb->len);
499
500 /* skb->dev passed may be master dev for vrfs. */
501 if (sdif) {
502 rcu_read_lock();
503 dev = dev_get_by_index_rcu(dev_net(skb->dev), sdif);
504 if (!dev) {
505 rcu_read_unlock();
506 kfree_skb(skb);
507 return -ENODEV;
508 }
509 } else {
510 dev = skb->dev;
511 }
512
513 hdr = ipv6_hdr(skb);
514 deliver = ipv6_chk_mcast_addr(dev, &hdr->daddr, NULL);
515 if (sdif)
516 rcu_read_unlock();
517
518#ifdef CONFIG_IPV6_MROUTE
519 /*
520 * IPv6 multicast router mode is now supported ;)
521 */
522 if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
523 !(ipv6_addr_type(&hdr->daddr) &
524 (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) &&
525 likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
526 /*
527 * Okay, we try to forward - split and duplicate
528 * packets.
529 */
530 struct sk_buff *skb2;
531 struct inet6_skb_parm *opt = IP6CB(skb);
532
533 /* Check for MLD */
534 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
535 /* Check if this is a mld message */
536 u8 nexthdr = hdr->nexthdr;
537 __be16 frag_off;
538 int offset;
539
540 /* Check if the value of Router Alert
541 * is for MLD (0x0000).
542 */
543 if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) {
544 deliver = false;
545
546 if (!ipv6_ext_hdr(nexthdr)) {
547 /* BUG */
548 goto out;
549 }
550 offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
551 &nexthdr, &frag_off);
552 if (offset < 0)
553 goto out;
554
555 if (ipv6_is_mld(skb, nexthdr, offset))
556 deliver = true;
557
558 goto out;
559 }
560 /* unknown RA - process it normally */
561 }
562
563 if (deliver)
564 skb2 = skb_clone(skb, GFP_ATOMIC);
565 else {
566 skb2 = skb;
567 skb = NULL;
568 }
569
570 if (skb2) {
571 ip6_mr_input(skb2);
572 }
573 }
574out:
575#endif
576 if (likely(deliver))
577 ip6_input(skb);
578 else {
579 /* discard */
580 kfree_skb(skb);
581 }
582
583 return 0;
584}