1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2013 Nicira, Inc.
4 */
5
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/skbuff.h>
11 #include <linux/netdevice.h>
12 #include <linux/in.h>
13 #include <linux/if_arp.h>
14 #include <linux/init.h>
15 #include <linux/in6.h>
16 #include <linux/inetdevice.h>
17 #include <linux/netfilter_ipv4.h>
18 #include <linux/etherdevice.h>
19 #include <linux/if_ether.h>
20 #include <linux/if_vlan.h>
21 #include <linux/static_key.h>
22
23 #include <net/ip.h>
24 #include <net/icmp.h>
25 #include <net/protocol.h>
26 #include <net/ip_tunnels.h>
27 #include <net/ip6_tunnel.h>
28 #include <net/ip6_checksum.h>
29 #include <net/arp.h>
30 #include <net/checksum.h>
31 #include <net/dsfield.h>
32 #include <net/inet_ecn.h>
33 #include <net/xfrm.h>
34 #include <net/net_namespace.h>
35 #include <net/netns/generic.h>
36 #include <net/rtnetlink.h>
37 #include <net/dst_metadata.h>
38 #include <net/geneve.h>
39 #include <net/vxlan.h>
40 #include <net/erspan.h>
41
42 const struct ip_tunnel_encap_ops __rcu *
43 iptun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
44 EXPORT_SYMBOL(iptun_encaps);
45
46 const struct ip6_tnl_encap_ops __rcu *
47 ip6tun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
48 EXPORT_SYMBOL(ip6tun_encaps);
49
iptunnel_xmit(struct sock * sk,struct rtable * rt,struct sk_buff * skb,__be32 src,__be32 dst,__u8 proto,__u8 tos,__u8 ttl,__be16 df,bool xnet)50 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
51 __be32 src, __be32 dst, __u8 proto,
52 __u8 tos, __u8 ttl, __be16 df, bool xnet)
53 {
54 int pkt_len = skb->len - skb_inner_network_offset(skb);
55 struct net *net = dev_net(rt->dst.dev);
56 struct net_device *dev = skb->dev;
57 struct iphdr *iph;
58 int err;
59
60 skb_scrub_packet(skb, xnet);
61
62 skb_clear_hash_if_not_l4(skb);
63 skb_dst_set(skb, &rt->dst);
64 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
65
66 /* Push down and install the IP header. */
67 skb_push(skb, sizeof(struct iphdr));
68 skb_reset_network_header(skb);
69
70 iph = ip_hdr(skb);
71
72 iph->version = 4;
73 iph->ihl = sizeof(struct iphdr) >> 2;
74 iph->frag_off = ip_mtu_locked(&rt->dst) ? 0 : df;
75 iph->protocol = proto;
76 iph->tos = tos;
77 iph->daddr = dst;
78 iph->saddr = src;
79 iph->ttl = ttl;
80 __ip_select_ident(net, iph, skb_shinfo(skb)->gso_segs ?: 1);
81
82 err = ip_local_out(net, sk, skb);
83
84 if (dev) {
85 if (unlikely(net_xmit_eval(err)))
86 pkt_len = 0;
87 iptunnel_xmit_stats(dev, pkt_len);
88 }
89 }
90 EXPORT_SYMBOL_GPL(iptunnel_xmit);
91
__iptunnel_pull_header(struct sk_buff * skb,int hdr_len,__be16 inner_proto,bool raw_proto,bool xnet)92 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
93 __be16 inner_proto, bool raw_proto, bool xnet)
94 {
95 if (unlikely(!pskb_may_pull(skb, hdr_len)))
96 return -ENOMEM;
97
98 skb_pull_rcsum(skb, hdr_len);
99
100 if (!raw_proto && inner_proto == htons(ETH_P_TEB)) {
101 struct ethhdr *eh;
102
103 if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
104 return -ENOMEM;
105
106 eh = (struct ethhdr *)skb->data;
107 if (likely(eth_proto_is_802_3(eh->h_proto)))
108 skb->protocol = eh->h_proto;
109 else
110 skb->protocol = htons(ETH_P_802_2);
111
112 } else {
113 skb->protocol = inner_proto;
114 }
115
116 skb_clear_hash_if_not_l4(skb);
117 __vlan_hwaccel_clear_tag(skb);
118 skb_set_queue_mapping(skb, 0);
119 skb_scrub_packet(skb, xnet);
120
121 return iptunnel_pull_offloads(skb);
122 }
123 EXPORT_SYMBOL_GPL(__iptunnel_pull_header);
124
iptunnel_metadata_reply(struct metadata_dst * md,gfp_t flags)125 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
126 gfp_t flags)
127 {
128 struct metadata_dst *res;
129 struct ip_tunnel_info *dst, *src;
130
131 if (!md || md->type != METADATA_IP_TUNNEL ||
132 md->u.tun_info.mode & IP_TUNNEL_INFO_TX)
133 return NULL;
134
135 src = &md->u.tun_info;
136 res = metadata_dst_alloc(src->options_len, METADATA_IP_TUNNEL, flags);
137 if (!res)
138 return NULL;
139
140 dst = &res->u.tun_info;
141 dst->key.tun_id = src->key.tun_id;
142 if (src->mode & IP_TUNNEL_INFO_IPV6)
143 memcpy(&dst->key.u.ipv6.dst, &src->key.u.ipv6.src,
144 sizeof(struct in6_addr));
145 else
146 dst->key.u.ipv4.dst = src->key.u.ipv4.src;
147 dst->key.tun_flags = src->key.tun_flags;
148 dst->mode = src->mode | IP_TUNNEL_INFO_TX;
149 ip_tunnel_info_opts_set(dst, ip_tunnel_info_opts(src),
150 src->options_len, 0);
151
152 return res;
153 }
154 EXPORT_SYMBOL_GPL(iptunnel_metadata_reply);
155
iptunnel_handle_offloads(struct sk_buff * skb,int gso_type_mask)156 int iptunnel_handle_offloads(struct sk_buff *skb,
157 int gso_type_mask)
158 {
159 int err;
160
161 if (likely(!skb->encapsulation)) {
162 skb_reset_inner_headers(skb);
163 skb->encapsulation = 1;
164 }
165
166 if (skb_is_gso(skb)) {
167 err = skb_header_unclone(skb, GFP_ATOMIC);
168 if (unlikely(err))
169 return err;
170 skb_shinfo(skb)->gso_type |= gso_type_mask;
171 return 0;
172 }
173
174 if (skb->ip_summed != CHECKSUM_PARTIAL) {
175 skb->ip_summed = CHECKSUM_NONE;
176 /* We clear encapsulation here to prevent badly-written
177 * drivers potentially deciding to offload an inner checksum
178 * if we set CHECKSUM_PARTIAL on the outer header.
179 * This should go away when the drivers are all fixed.
180 */
181 skb->encapsulation = 0;
182 }
183
184 return 0;
185 }
186 EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);
187
188 /**
189 * iptunnel_pmtud_build_icmp() - Build ICMP error message for PMTUD
190 * @skb: Original packet with L2 header
191 * @mtu: MTU value for ICMP error
192 *
193 * Return: length on success, negative error code if message couldn't be built.
194 */
iptunnel_pmtud_build_icmp(struct sk_buff * skb,int mtu)195 static int iptunnel_pmtud_build_icmp(struct sk_buff *skb, int mtu)
196 {
197 const struct iphdr *iph = ip_hdr(skb);
198 struct icmphdr *icmph;
199 struct iphdr *niph;
200 struct ethhdr eh;
201 int len, err;
202
203 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
204 return -EINVAL;
205
206 skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN);
207 pskb_pull(skb, ETH_HLEN);
208 skb_reset_network_header(skb);
209
210 err = pskb_trim(skb, 576 - sizeof(*niph) - sizeof(*icmph));
211 if (err)
212 return err;
213
214 len = skb->len + sizeof(*icmph);
215 err = skb_cow(skb, sizeof(*niph) + sizeof(*icmph) + ETH_HLEN);
216 if (err)
217 return err;
218
219 icmph = skb_push(skb, sizeof(*icmph));
220 *icmph = (struct icmphdr) {
221 .type = ICMP_DEST_UNREACH,
222 .code = ICMP_FRAG_NEEDED,
223 .checksum = 0,
224 .un.frag.__unused = 0,
225 .un.frag.mtu = htons(mtu),
226 };
227 icmph->checksum = ip_compute_csum(icmph, len);
228 skb_reset_transport_header(skb);
229
230 niph = skb_push(skb, sizeof(*niph));
231 *niph = (struct iphdr) {
232 .ihl = sizeof(*niph) / 4u,
233 .version = 4,
234 .tos = 0,
235 .tot_len = htons(len + sizeof(*niph)),
236 .id = 0,
237 .frag_off = htons(IP_DF),
238 .ttl = iph->ttl,
239 .protocol = IPPROTO_ICMP,
240 .saddr = iph->daddr,
241 .daddr = iph->saddr,
242 };
243 ip_send_check(niph);
244 skb_reset_network_header(skb);
245
246 skb->ip_summed = CHECKSUM_NONE;
247
248 eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);
249 skb_reset_mac_header(skb);
250
251 return skb->len;
252 }
253
254 /**
255 * iptunnel_pmtud_check_icmp() - Trigger ICMP reply if needed and allowed
256 * @skb: Buffer being sent by encapsulation, L2 headers expected
257 * @mtu: Network MTU for path
258 *
259 * Return: 0 for no ICMP reply, length if built, negative value on error.
260 */
iptunnel_pmtud_check_icmp(struct sk_buff * skb,int mtu)261 static int iptunnel_pmtud_check_icmp(struct sk_buff *skb, int mtu)
262 {
263 const struct icmphdr *icmph = icmp_hdr(skb);
264 const struct iphdr *iph = ip_hdr(skb);
265
266 if (mtu < 576 || iph->frag_off != htons(IP_DF))
267 return 0;
268
269 if (ipv4_is_lbcast(iph->daddr) || ipv4_is_multicast(iph->daddr) ||
270 ipv4_is_zeronet(iph->saddr) || ipv4_is_loopback(iph->saddr) ||
271 ipv4_is_lbcast(iph->saddr) || ipv4_is_multicast(iph->saddr))
272 return 0;
273
274 if (iph->protocol == IPPROTO_ICMP && icmp_is_err(icmph->type))
275 return 0;
276
277 return iptunnel_pmtud_build_icmp(skb, mtu);
278 }
279
280 #if IS_ENABLED(CONFIG_IPV6)
281 /**
282 * iptunnel_pmtud_build_icmpv6() - Build ICMPv6 error message for PMTUD
283 * @skb: Original packet with L2 header
284 * @mtu: MTU value for ICMPv6 error
285 *
286 * Return: length on success, negative error code if message couldn't be built.
287 */
iptunnel_pmtud_build_icmpv6(struct sk_buff * skb,int mtu)288 static int iptunnel_pmtud_build_icmpv6(struct sk_buff *skb, int mtu)
289 {
290 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
291 struct icmp6hdr *icmp6h;
292 struct ipv6hdr *nip6h;
293 struct ethhdr eh;
294 int len, err;
295 __wsum csum;
296
297 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
298 return -EINVAL;
299
300 skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN);
301 pskb_pull(skb, ETH_HLEN);
302 skb_reset_network_header(skb);
303
304 err = pskb_trim(skb, IPV6_MIN_MTU - sizeof(*nip6h) - sizeof(*icmp6h));
305 if (err)
306 return err;
307
308 len = skb->len + sizeof(*icmp6h);
309 err = skb_cow(skb, sizeof(*nip6h) + sizeof(*icmp6h) + ETH_HLEN);
310 if (err)
311 return err;
312
313 icmp6h = skb_push(skb, sizeof(*icmp6h));
314 *icmp6h = (struct icmp6hdr) {
315 .icmp6_type = ICMPV6_PKT_TOOBIG,
316 .icmp6_code = 0,
317 .icmp6_cksum = 0,
318 .icmp6_mtu = htonl(mtu),
319 };
320 skb_reset_transport_header(skb);
321
322 nip6h = skb_push(skb, sizeof(*nip6h));
323 *nip6h = (struct ipv6hdr) {
324 .priority = 0,
325 .version = 6,
326 .flow_lbl = { 0 },
327 .payload_len = htons(len),
328 .nexthdr = IPPROTO_ICMPV6,
329 .hop_limit = ip6h->hop_limit,
330 .saddr = ip6h->daddr,
331 .daddr = ip6h->saddr,
332 };
333 skb_reset_network_header(skb);
334
335 csum = csum_partial(icmp6h, len, 0);
336 icmp6h->icmp6_cksum = csum_ipv6_magic(&nip6h->saddr, &nip6h->daddr, len,
337 IPPROTO_ICMPV6, csum);
338
339 skb->ip_summed = CHECKSUM_NONE;
340
341 eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);
342 skb_reset_mac_header(skb);
343
344 return skb->len;
345 }
346
347 /**
348 * iptunnel_pmtud_check_icmpv6() - Trigger ICMPv6 reply if needed and allowed
349 * @skb: Buffer being sent by encapsulation, L2 headers expected
350 * @mtu: Network MTU for path
351 *
352 * Return: 0 for no ICMPv6 reply, length if built, negative value on error.
353 */
iptunnel_pmtud_check_icmpv6(struct sk_buff * skb,int mtu)354 static int iptunnel_pmtud_check_icmpv6(struct sk_buff *skb, int mtu)
355 {
356 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
357 int stype = ipv6_addr_type(&ip6h->saddr);
358 u8 proto = ip6h->nexthdr;
359 __be16 frag_off;
360 int offset;
361
362 if (mtu < IPV6_MIN_MTU)
363 return 0;
364
365 if (stype == IPV6_ADDR_ANY || stype == IPV6_ADDR_MULTICAST ||
366 stype == IPV6_ADDR_LOOPBACK)
367 return 0;
368
369 offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &proto,
370 &frag_off);
371 if (offset < 0 || (frag_off & htons(~0x7)))
372 return 0;
373
374 if (proto == IPPROTO_ICMPV6) {
375 struct icmp6hdr *icmp6h;
376
377 if (!pskb_may_pull(skb, skb_network_header(skb) +
378 offset + 1 - skb->data))
379 return 0;
380
381 icmp6h = (struct icmp6hdr *)(skb_network_header(skb) + offset);
382 if (icmpv6_is_err(icmp6h->icmp6_type) ||
383 icmp6h->icmp6_type == NDISC_REDIRECT)
384 return 0;
385 }
386
387 return iptunnel_pmtud_build_icmpv6(skb, mtu);
388 }
389 #endif /* IS_ENABLED(CONFIG_IPV6) */
390
391 /**
392 * skb_tunnel_check_pmtu() - Check, update PMTU and trigger ICMP reply as needed
393 * @skb: Buffer being sent by encapsulation, L2 headers expected
394 * @encap_dst: Destination for tunnel encapsulation (outer IP)
395 * @headroom: Encapsulation header size, bytes
396 * @reply: Build matching ICMP or ICMPv6 message as a result
397 *
398 * L2 tunnel implementations that can carry IP and can be directly bridged
399 * (currently UDP tunnels) can't always rely on IP forwarding paths to handle
400 * PMTU discovery. In the bridged case, ICMP or ICMPv6 messages need to be built
401 * based on payload and sent back by the encapsulation itself.
402 *
403 * For routable interfaces, we just need to update the PMTU for the destination.
404 *
405 * Return: 0 if ICMP error not needed, length if built, negative value on error
406 */
skb_tunnel_check_pmtu(struct sk_buff * skb,struct dst_entry * encap_dst,int headroom,bool reply)407 int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst,
408 int headroom, bool reply)
409 {
410 u32 mtu = dst_mtu(encap_dst) - headroom;
411
412 if ((skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) ||
413 (!skb_is_gso(skb) && (skb->len - skb_network_offset(skb)) <= mtu))
414 return 0;
415
416 skb_dst_update_pmtu_no_confirm(skb, mtu);
417
418 if (!reply || skb->pkt_type == PACKET_HOST)
419 return 0;
420
421 if (skb->protocol == htons(ETH_P_IP))
422 return iptunnel_pmtud_check_icmp(skb, mtu);
423
424 #if IS_ENABLED(CONFIG_IPV6)
425 if (skb->protocol == htons(ETH_P_IPV6))
426 return iptunnel_pmtud_check_icmpv6(skb, mtu);
427 #endif
428 return 0;
429 }
430 EXPORT_SYMBOL(skb_tunnel_check_pmtu);
431
432 static const struct nla_policy ip_tun_policy[LWTUNNEL_IP_MAX + 1] = {
433 [LWTUNNEL_IP_UNSPEC] = { .strict_start_type = LWTUNNEL_IP_OPTS },
434 [LWTUNNEL_IP_ID] = { .type = NLA_U64 },
435 [LWTUNNEL_IP_DST] = { .type = NLA_U32 },
436 [LWTUNNEL_IP_SRC] = { .type = NLA_U32 },
437 [LWTUNNEL_IP_TTL] = { .type = NLA_U8 },
438 [LWTUNNEL_IP_TOS] = { .type = NLA_U8 },
439 [LWTUNNEL_IP_FLAGS] = { .type = NLA_U16 },
440 [LWTUNNEL_IP_OPTS] = { .type = NLA_NESTED },
441 };
442
443 static const struct nla_policy ip_opts_policy[LWTUNNEL_IP_OPTS_MAX + 1] = {
444 [LWTUNNEL_IP_OPTS_GENEVE] = { .type = NLA_NESTED },
445 [LWTUNNEL_IP_OPTS_VXLAN] = { .type = NLA_NESTED },
446 [LWTUNNEL_IP_OPTS_ERSPAN] = { .type = NLA_NESTED },
447 };
448
449 static const struct nla_policy
450 geneve_opt_policy[LWTUNNEL_IP_OPT_GENEVE_MAX + 1] = {
451 [LWTUNNEL_IP_OPT_GENEVE_CLASS] = { .type = NLA_U16 },
452 [LWTUNNEL_IP_OPT_GENEVE_TYPE] = { .type = NLA_U8 },
453 [LWTUNNEL_IP_OPT_GENEVE_DATA] = { .type = NLA_BINARY, .len = 128 },
454 };
455
456 static const struct nla_policy
457 vxlan_opt_policy[LWTUNNEL_IP_OPT_VXLAN_MAX + 1] = {
458 [LWTUNNEL_IP_OPT_VXLAN_GBP] = { .type = NLA_U32 },
459 };
460
461 static const struct nla_policy
462 erspan_opt_policy[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1] = {
463 [LWTUNNEL_IP_OPT_ERSPAN_VER] = { .type = NLA_U8 },
464 [LWTUNNEL_IP_OPT_ERSPAN_INDEX] = { .type = NLA_U32 },
465 [LWTUNNEL_IP_OPT_ERSPAN_DIR] = { .type = NLA_U8 },
466 [LWTUNNEL_IP_OPT_ERSPAN_HWID] = { .type = NLA_U8 },
467 };
468
ip_tun_parse_opts_geneve(struct nlattr * attr,struct ip_tunnel_info * info,int opts_len,struct netlink_ext_ack * extack)469 static int ip_tun_parse_opts_geneve(struct nlattr *attr,
470 struct ip_tunnel_info *info, int opts_len,
471 struct netlink_ext_ack *extack)
472 {
473 struct nlattr *tb[LWTUNNEL_IP_OPT_GENEVE_MAX + 1];
474 int data_len, err;
475
476 err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_GENEVE_MAX, attr,
477 geneve_opt_policy, extack);
478 if (err)
479 return err;
480
481 if (!tb[LWTUNNEL_IP_OPT_GENEVE_CLASS] ||
482 !tb[LWTUNNEL_IP_OPT_GENEVE_TYPE] ||
483 !tb[LWTUNNEL_IP_OPT_GENEVE_DATA])
484 return -EINVAL;
485
486 attr = tb[LWTUNNEL_IP_OPT_GENEVE_DATA];
487 data_len = nla_len(attr);
488 if (data_len % 4)
489 return -EINVAL;
490
491 if (info) {
492 struct geneve_opt *opt = ip_tunnel_info_opts(info) + opts_len;
493
494 memcpy(opt->opt_data, nla_data(attr), data_len);
495 opt->length = data_len / 4;
496 attr = tb[LWTUNNEL_IP_OPT_GENEVE_CLASS];
497 opt->opt_class = nla_get_be16(attr);
498 attr = tb[LWTUNNEL_IP_OPT_GENEVE_TYPE];
499 opt->type = nla_get_u8(attr);
500 info->key.tun_flags |= TUNNEL_GENEVE_OPT;
501 }
502
503 return sizeof(struct geneve_opt) + data_len;
504 }
505
ip_tun_parse_opts_vxlan(struct nlattr * attr,struct ip_tunnel_info * info,int opts_len,struct netlink_ext_ack * extack)506 static int ip_tun_parse_opts_vxlan(struct nlattr *attr,
507 struct ip_tunnel_info *info, int opts_len,
508 struct netlink_ext_ack *extack)
509 {
510 struct nlattr *tb[LWTUNNEL_IP_OPT_VXLAN_MAX + 1];
511 int err;
512
513 err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_VXLAN_MAX, attr,
514 vxlan_opt_policy, extack);
515 if (err)
516 return err;
517
518 if (!tb[LWTUNNEL_IP_OPT_VXLAN_GBP])
519 return -EINVAL;
520
521 if (info) {
522 struct vxlan_metadata *md =
523 ip_tunnel_info_opts(info) + opts_len;
524
525 attr = tb[LWTUNNEL_IP_OPT_VXLAN_GBP];
526 md->gbp = nla_get_u32(attr);
527 md->gbp &= VXLAN_GBP_MASK;
528 info->key.tun_flags |= TUNNEL_VXLAN_OPT;
529 }
530
531 return sizeof(struct vxlan_metadata);
532 }
533
ip_tun_parse_opts_erspan(struct nlattr * attr,struct ip_tunnel_info * info,int opts_len,struct netlink_ext_ack * extack)534 static int ip_tun_parse_opts_erspan(struct nlattr *attr,
535 struct ip_tunnel_info *info, int opts_len,
536 struct netlink_ext_ack *extack)
537 {
538 struct nlattr *tb[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1];
539 int err;
540 u8 ver;
541
542 err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_ERSPAN_MAX, attr,
543 erspan_opt_policy, extack);
544 if (err)
545 return err;
546
547 if (!tb[LWTUNNEL_IP_OPT_ERSPAN_VER])
548 return -EINVAL;
549
550 ver = nla_get_u8(tb[LWTUNNEL_IP_OPT_ERSPAN_VER]);
551 if (ver == 1) {
552 if (!tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX])
553 return -EINVAL;
554 } else if (ver == 2) {
555 if (!tb[LWTUNNEL_IP_OPT_ERSPAN_DIR] ||
556 !tb[LWTUNNEL_IP_OPT_ERSPAN_HWID])
557 return -EINVAL;
558 } else {
559 return -EINVAL;
560 }
561
562 if (info) {
563 struct erspan_metadata *md =
564 ip_tunnel_info_opts(info) + opts_len;
565
566 md->version = ver;
567 if (ver == 1) {
568 attr = tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX];
569 md->u.index = nla_get_be32(attr);
570 } else {
571 attr = tb[LWTUNNEL_IP_OPT_ERSPAN_DIR];
572 md->u.md2.dir = nla_get_u8(attr);
573 attr = tb[LWTUNNEL_IP_OPT_ERSPAN_HWID];
574 set_hwid(&md->u.md2, nla_get_u8(attr));
575 }
576
577 info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
578 }
579
580 return sizeof(struct erspan_metadata);
581 }
582
ip_tun_parse_opts(struct nlattr * attr,struct ip_tunnel_info * info,struct netlink_ext_ack * extack)583 static int ip_tun_parse_opts(struct nlattr *attr, struct ip_tunnel_info *info,
584 struct netlink_ext_ack *extack)
585 {
586 int err, rem, opt_len, opts_len = 0;
587 struct nlattr *nla;
588 __be16 type = 0;
589
590 if (!attr)
591 return 0;
592
593 err = nla_validate(nla_data(attr), nla_len(attr), LWTUNNEL_IP_OPTS_MAX,
594 ip_opts_policy, extack);
595 if (err)
596 return err;
597
598 nla_for_each_attr(nla, nla_data(attr), nla_len(attr), rem) {
599 switch (nla_type(nla)) {
600 case LWTUNNEL_IP_OPTS_GENEVE:
601 if (type && type != TUNNEL_GENEVE_OPT)
602 return -EINVAL;
603 opt_len = ip_tun_parse_opts_geneve(nla, info, opts_len,
604 extack);
605 if (opt_len < 0)
606 return opt_len;
607 opts_len += opt_len;
608 if (opts_len > IP_TUNNEL_OPTS_MAX)
609 return -EINVAL;
610 type = TUNNEL_GENEVE_OPT;
611 break;
612 case LWTUNNEL_IP_OPTS_VXLAN:
613 if (type)
614 return -EINVAL;
615 opt_len = ip_tun_parse_opts_vxlan(nla, info, opts_len,
616 extack);
617 if (opt_len < 0)
618 return opt_len;
619 opts_len += opt_len;
620 type = TUNNEL_VXLAN_OPT;
621 break;
622 case LWTUNNEL_IP_OPTS_ERSPAN:
623 if (type)
624 return -EINVAL;
625 opt_len = ip_tun_parse_opts_erspan(nla, info, opts_len,
626 extack);
627 if (opt_len < 0)
628 return opt_len;
629 opts_len += opt_len;
630 type = TUNNEL_ERSPAN_OPT;
631 break;
632 default:
633 return -EINVAL;
634 }
635 }
636
637 return opts_len;
638 }
639
ip_tun_get_optlen(struct nlattr * attr,struct netlink_ext_ack * extack)640 static int ip_tun_get_optlen(struct nlattr *attr,
641 struct netlink_ext_ack *extack)
642 {
643 return ip_tun_parse_opts(attr, NULL, extack);
644 }
645
ip_tun_set_opts(struct nlattr * attr,struct ip_tunnel_info * info,struct netlink_ext_ack * extack)646 static int ip_tun_set_opts(struct nlattr *attr, struct ip_tunnel_info *info,
647 struct netlink_ext_ack *extack)
648 {
649 return ip_tun_parse_opts(attr, info, extack);
650 }
651
ip_tun_build_state(struct net * net,struct nlattr * attr,unsigned int family,const void * cfg,struct lwtunnel_state ** ts,struct netlink_ext_ack * extack)652 static int ip_tun_build_state(struct net *net, struct nlattr *attr,
653 unsigned int family, const void *cfg,
654 struct lwtunnel_state **ts,
655 struct netlink_ext_ack *extack)
656 {
657 struct nlattr *tb[LWTUNNEL_IP_MAX + 1];
658 struct lwtunnel_state *new_state;
659 struct ip_tunnel_info *tun_info;
660 int err, opt_len;
661
662 err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP_MAX, attr,
663 ip_tun_policy, extack);
664 if (err < 0)
665 return err;
666
667 opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP_OPTS], extack);
668 if (opt_len < 0)
669 return opt_len;
670
671 new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len);
672 if (!new_state)
673 return -ENOMEM;
674
675 new_state->type = LWTUNNEL_ENCAP_IP;
676
677 tun_info = lwt_tun_info(new_state);
678
679 err = ip_tun_set_opts(tb[LWTUNNEL_IP_OPTS], tun_info, extack);
680 if (err < 0) {
681 lwtstate_free(new_state);
682 return err;
683 }
684
685 #ifdef CONFIG_DST_CACHE
686 err = dst_cache_init(&tun_info->dst_cache, GFP_KERNEL);
687 if (err) {
688 lwtstate_free(new_state);
689 return err;
690 }
691 #endif
692
693 if (tb[LWTUNNEL_IP_ID])
694 tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP_ID]);
695
696 if (tb[LWTUNNEL_IP_DST])
697 tun_info->key.u.ipv4.dst = nla_get_in_addr(tb[LWTUNNEL_IP_DST]);
698
699 if (tb[LWTUNNEL_IP_SRC])
700 tun_info->key.u.ipv4.src = nla_get_in_addr(tb[LWTUNNEL_IP_SRC]);
701
702 if (tb[LWTUNNEL_IP_TTL])
703 tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP_TTL]);
704
705 if (tb[LWTUNNEL_IP_TOS])
706 tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP_TOS]);
707
708 if (tb[LWTUNNEL_IP_FLAGS])
709 tun_info->key.tun_flags |=
710 (nla_get_be16(tb[LWTUNNEL_IP_FLAGS]) &
711 ~TUNNEL_OPTIONS_PRESENT);
712
713 tun_info->mode = IP_TUNNEL_INFO_TX;
714 tun_info->options_len = opt_len;
715
716 *ts = new_state;
717
718 return 0;
719 }
720
ip_tun_destroy_state(struct lwtunnel_state * lwtstate)721 static void ip_tun_destroy_state(struct lwtunnel_state *lwtstate)
722 {
723 #ifdef CONFIG_DST_CACHE
724 struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
725
726 dst_cache_destroy(&tun_info->dst_cache);
727 #endif
728 }
729
ip_tun_fill_encap_opts_geneve(struct sk_buff * skb,struct ip_tunnel_info * tun_info)730 static int ip_tun_fill_encap_opts_geneve(struct sk_buff *skb,
731 struct ip_tunnel_info *tun_info)
732 {
733 struct geneve_opt *opt;
734 struct nlattr *nest;
735 int offset = 0;
736
737 nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_GENEVE);
738 if (!nest)
739 return -ENOMEM;
740
741 while (tun_info->options_len > offset) {
742 opt = ip_tunnel_info_opts(tun_info) + offset;
743 if (nla_put_be16(skb, LWTUNNEL_IP_OPT_GENEVE_CLASS,
744 opt->opt_class) ||
745 nla_put_u8(skb, LWTUNNEL_IP_OPT_GENEVE_TYPE, opt->type) ||
746 nla_put(skb, LWTUNNEL_IP_OPT_GENEVE_DATA, opt->length * 4,
747 opt->opt_data)) {
748 nla_nest_cancel(skb, nest);
749 return -ENOMEM;
750 }
751 offset += sizeof(*opt) + opt->length * 4;
752 }
753
754 nla_nest_end(skb, nest);
755 return 0;
756 }
757
ip_tun_fill_encap_opts_vxlan(struct sk_buff * skb,struct ip_tunnel_info * tun_info)758 static int ip_tun_fill_encap_opts_vxlan(struct sk_buff *skb,
759 struct ip_tunnel_info *tun_info)
760 {
761 struct vxlan_metadata *md;
762 struct nlattr *nest;
763
764 nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_VXLAN);
765 if (!nest)
766 return -ENOMEM;
767
768 md = ip_tunnel_info_opts(tun_info);
769 if (nla_put_u32(skb, LWTUNNEL_IP_OPT_VXLAN_GBP, md->gbp)) {
770 nla_nest_cancel(skb, nest);
771 return -ENOMEM;
772 }
773
774 nla_nest_end(skb, nest);
775 return 0;
776 }
777
ip_tun_fill_encap_opts_erspan(struct sk_buff * skb,struct ip_tunnel_info * tun_info)778 static int ip_tun_fill_encap_opts_erspan(struct sk_buff *skb,
779 struct ip_tunnel_info *tun_info)
780 {
781 struct erspan_metadata *md;
782 struct nlattr *nest;
783
784 nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_ERSPAN);
785 if (!nest)
786 return -ENOMEM;
787
788 md = ip_tunnel_info_opts(tun_info);
789 if (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_VER, md->version))
790 goto err;
791
792 if (md->version == 1 &&
793 nla_put_be32(skb, LWTUNNEL_IP_OPT_ERSPAN_INDEX, md->u.index))
794 goto err;
795
796 if (md->version == 2 &&
797 (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_DIR, md->u.md2.dir) ||
798 nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_HWID,
799 get_hwid(&md->u.md2))))
800 goto err;
801
802 nla_nest_end(skb, nest);
803 return 0;
804 err:
805 nla_nest_cancel(skb, nest);
806 return -ENOMEM;
807 }
808
ip_tun_fill_encap_opts(struct sk_buff * skb,int type,struct ip_tunnel_info * tun_info)809 static int ip_tun_fill_encap_opts(struct sk_buff *skb, int type,
810 struct ip_tunnel_info *tun_info)
811 {
812 struct nlattr *nest;
813 int err = 0;
814
815 if (!(tun_info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))
816 return 0;
817
818 nest = nla_nest_start_noflag(skb, type);
819 if (!nest)
820 return -ENOMEM;
821
822 if (tun_info->key.tun_flags & TUNNEL_GENEVE_OPT)
823 err = ip_tun_fill_encap_opts_geneve(skb, tun_info);
824 else if (tun_info->key.tun_flags & TUNNEL_VXLAN_OPT)
825 err = ip_tun_fill_encap_opts_vxlan(skb, tun_info);
826 else if (tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)
827 err = ip_tun_fill_encap_opts_erspan(skb, tun_info);
828
829 if (err) {
830 nla_nest_cancel(skb, nest);
831 return err;
832 }
833
834 nla_nest_end(skb, nest);
835 return 0;
836 }
837
ip_tun_fill_encap_info(struct sk_buff * skb,struct lwtunnel_state * lwtstate)838 static int ip_tun_fill_encap_info(struct sk_buff *skb,
839 struct lwtunnel_state *lwtstate)
840 {
841 struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
842
843 if (nla_put_be64(skb, LWTUNNEL_IP_ID, tun_info->key.tun_id,
844 LWTUNNEL_IP_PAD) ||
845 nla_put_in_addr(skb, LWTUNNEL_IP_DST, tun_info->key.u.ipv4.dst) ||
846 nla_put_in_addr(skb, LWTUNNEL_IP_SRC, tun_info->key.u.ipv4.src) ||
847 nla_put_u8(skb, LWTUNNEL_IP_TOS, tun_info->key.tos) ||
848 nla_put_u8(skb, LWTUNNEL_IP_TTL, tun_info->key.ttl) ||
849 nla_put_be16(skb, LWTUNNEL_IP_FLAGS, tun_info->key.tun_flags) ||
850 ip_tun_fill_encap_opts(skb, LWTUNNEL_IP_OPTS, tun_info))
851 return -ENOMEM;
852
853 return 0;
854 }
855
ip_tun_opts_nlsize(struct ip_tunnel_info * info)856 static int ip_tun_opts_nlsize(struct ip_tunnel_info *info)
857 {
858 int opt_len;
859
860 if (!(info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))
861 return 0;
862
863 opt_len = nla_total_size(0); /* LWTUNNEL_IP_OPTS */
864 if (info->key.tun_flags & TUNNEL_GENEVE_OPT) {
865 struct geneve_opt *opt;
866 int offset = 0;
867
868 opt_len += nla_total_size(0); /* LWTUNNEL_IP_OPTS_GENEVE */
869 while (info->options_len > offset) {
870 opt = ip_tunnel_info_opts(info) + offset;
871 opt_len += nla_total_size(2) /* OPT_GENEVE_CLASS */
872 + nla_total_size(1) /* OPT_GENEVE_TYPE */
873 + nla_total_size(opt->length * 4);
874 /* OPT_GENEVE_DATA */
875 offset += sizeof(*opt) + opt->length * 4;
876 }
877 } else if (info->key.tun_flags & TUNNEL_VXLAN_OPT) {
878 opt_len += nla_total_size(0) /* LWTUNNEL_IP_OPTS_VXLAN */
879 + nla_total_size(4); /* OPT_VXLAN_GBP */
880 } else if (info->key.tun_flags & TUNNEL_ERSPAN_OPT) {
881 struct erspan_metadata *md = ip_tunnel_info_opts(info);
882
883 opt_len += nla_total_size(0) /* LWTUNNEL_IP_OPTS_ERSPAN */
884 + nla_total_size(1) /* OPT_ERSPAN_VER */
885 + (md->version == 1 ? nla_total_size(4)
886 /* OPT_ERSPAN_INDEX (v1) */
887 : nla_total_size(1) +
888 nla_total_size(1));
889 /* OPT_ERSPAN_DIR + HWID (v2) */
890 }
891
892 return opt_len;
893 }
894
ip_tun_encap_nlsize(struct lwtunnel_state * lwtstate)895 static int ip_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
896 {
897 return nla_total_size_64bit(8) /* LWTUNNEL_IP_ID */
898 + nla_total_size(4) /* LWTUNNEL_IP_DST */
899 + nla_total_size(4) /* LWTUNNEL_IP_SRC */
900 + nla_total_size(1) /* LWTUNNEL_IP_TOS */
901 + nla_total_size(1) /* LWTUNNEL_IP_TTL */
902 + nla_total_size(2) /* LWTUNNEL_IP_FLAGS */
903 + ip_tun_opts_nlsize(lwt_tun_info(lwtstate));
904 /* LWTUNNEL_IP_OPTS */
905 }
906
ip_tun_cmp_encap(struct lwtunnel_state * a,struct lwtunnel_state * b)907 static int ip_tun_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
908 {
909 struct ip_tunnel_info *info_a = lwt_tun_info(a);
910 struct ip_tunnel_info *info_b = lwt_tun_info(b);
911
912 return memcmp(info_a, info_b, sizeof(info_a->key)) ||
913 info_a->mode != info_b->mode ||
914 info_a->options_len != info_b->options_len ||
915 memcmp(ip_tunnel_info_opts(info_a),
916 ip_tunnel_info_opts(info_b), info_a->options_len);
917 }
918
919 static const struct lwtunnel_encap_ops ip_tun_lwt_ops = {
920 .build_state = ip_tun_build_state,
921 .destroy_state = ip_tun_destroy_state,
922 .fill_encap = ip_tun_fill_encap_info,
923 .get_encap_size = ip_tun_encap_nlsize,
924 .cmp_encap = ip_tun_cmp_encap,
925 .owner = THIS_MODULE,
926 };
927
928 static const struct nla_policy ip6_tun_policy[LWTUNNEL_IP6_MAX + 1] = {
929 [LWTUNNEL_IP6_UNSPEC] = { .strict_start_type = LWTUNNEL_IP6_OPTS },
930 [LWTUNNEL_IP6_ID] = { .type = NLA_U64 },
931 [LWTUNNEL_IP6_DST] = { .len = sizeof(struct in6_addr) },
932 [LWTUNNEL_IP6_SRC] = { .len = sizeof(struct in6_addr) },
933 [LWTUNNEL_IP6_HOPLIMIT] = { .type = NLA_U8 },
934 [LWTUNNEL_IP6_TC] = { .type = NLA_U8 },
935 [LWTUNNEL_IP6_FLAGS] = { .type = NLA_U16 },
936 [LWTUNNEL_IP6_OPTS] = { .type = NLA_NESTED },
937 };
938
ip6_tun_build_state(struct net * net,struct nlattr * attr,unsigned int family,const void * cfg,struct lwtunnel_state ** ts,struct netlink_ext_ack * extack)939 static int ip6_tun_build_state(struct net *net, struct nlattr *attr,
940 unsigned int family, const void *cfg,
941 struct lwtunnel_state **ts,
942 struct netlink_ext_ack *extack)
943 {
944 struct nlattr *tb[LWTUNNEL_IP6_MAX + 1];
945 struct lwtunnel_state *new_state;
946 struct ip_tunnel_info *tun_info;
947 int err, opt_len;
948
949 err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP6_MAX, attr,
950 ip6_tun_policy, extack);
951 if (err < 0)
952 return err;
953
954 opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP6_OPTS], extack);
955 if (opt_len < 0)
956 return opt_len;
957
958 new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len);
959 if (!new_state)
960 return -ENOMEM;
961
962 new_state->type = LWTUNNEL_ENCAP_IP6;
963
964 tun_info = lwt_tun_info(new_state);
965
966 err = ip_tun_set_opts(tb[LWTUNNEL_IP6_OPTS], tun_info, extack);
967 if (err < 0) {
968 lwtstate_free(new_state);
969 return err;
970 }
971
972 if (tb[LWTUNNEL_IP6_ID])
973 tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP6_ID]);
974
975 if (tb[LWTUNNEL_IP6_DST])
976 tun_info->key.u.ipv6.dst = nla_get_in6_addr(tb[LWTUNNEL_IP6_DST]);
977
978 if (tb[LWTUNNEL_IP6_SRC])
979 tun_info->key.u.ipv6.src = nla_get_in6_addr(tb[LWTUNNEL_IP6_SRC]);
980
981 if (tb[LWTUNNEL_IP6_HOPLIMIT])
982 tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP6_HOPLIMIT]);
983
984 if (tb[LWTUNNEL_IP6_TC])
985 tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP6_TC]);
986
987 if (tb[LWTUNNEL_IP6_FLAGS])
988 tun_info->key.tun_flags |=
989 (nla_get_be16(tb[LWTUNNEL_IP6_FLAGS]) &
990 ~TUNNEL_OPTIONS_PRESENT);
991
992 tun_info->mode = IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_IPV6;
993 tun_info->options_len = opt_len;
994
995 *ts = new_state;
996
997 return 0;
998 }
999
ip6_tun_fill_encap_info(struct sk_buff * skb,struct lwtunnel_state * lwtstate)1000 static int ip6_tun_fill_encap_info(struct sk_buff *skb,
1001 struct lwtunnel_state *lwtstate)
1002 {
1003 struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
1004
1005 if (nla_put_be64(skb, LWTUNNEL_IP6_ID, tun_info->key.tun_id,
1006 LWTUNNEL_IP6_PAD) ||
1007 nla_put_in6_addr(skb, LWTUNNEL_IP6_DST, &tun_info->key.u.ipv6.dst) ||
1008 nla_put_in6_addr(skb, LWTUNNEL_IP6_SRC, &tun_info->key.u.ipv6.src) ||
1009 nla_put_u8(skb, LWTUNNEL_IP6_TC, tun_info->key.tos) ||
1010 nla_put_u8(skb, LWTUNNEL_IP6_HOPLIMIT, tun_info->key.ttl) ||
1011 nla_put_be16(skb, LWTUNNEL_IP6_FLAGS, tun_info->key.tun_flags) ||
1012 ip_tun_fill_encap_opts(skb, LWTUNNEL_IP6_OPTS, tun_info))
1013 return -ENOMEM;
1014
1015 return 0;
1016 }
1017
ip6_tun_encap_nlsize(struct lwtunnel_state * lwtstate)1018 static int ip6_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
1019 {
1020 return nla_total_size_64bit(8) /* LWTUNNEL_IP6_ID */
1021 + nla_total_size(16) /* LWTUNNEL_IP6_DST */
1022 + nla_total_size(16) /* LWTUNNEL_IP6_SRC */
1023 + nla_total_size(1) /* LWTUNNEL_IP6_HOPLIMIT */
1024 + nla_total_size(1) /* LWTUNNEL_IP6_TC */
1025 + nla_total_size(2) /* LWTUNNEL_IP6_FLAGS */
1026 + ip_tun_opts_nlsize(lwt_tun_info(lwtstate));
1027 /* LWTUNNEL_IP6_OPTS */
1028 }
1029
1030 static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = {
1031 .build_state = ip6_tun_build_state,
1032 .fill_encap = ip6_tun_fill_encap_info,
1033 .get_encap_size = ip6_tun_encap_nlsize,
1034 .cmp_encap = ip_tun_cmp_encap,
1035 .owner = THIS_MODULE,
1036 };
1037
ip_tunnel_core_init(void)1038 void __init ip_tunnel_core_init(void)
1039 {
1040 /* If you land here, make sure whether increasing ip_tunnel_info's
1041 * options_len is a reasonable choice with its usage in front ends
1042 * (f.e., it's part of flow keys, etc).
1043 */
1044 BUILD_BUG_ON(IP_TUNNEL_OPTS_MAX != 255);
1045
1046 lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP);
1047 lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6);
1048 }
1049
1050 DEFINE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
1051 EXPORT_SYMBOL(ip_tunnel_metadata_cnt);
1052
ip_tunnel_need_metadata(void)1053 void ip_tunnel_need_metadata(void)
1054 {
1055 static_branch_inc(&ip_tunnel_metadata_cnt);
1056 }
1057 EXPORT_SYMBOL_GPL(ip_tunnel_need_metadata);
1058
ip_tunnel_unneed_metadata(void)1059 void ip_tunnel_unneed_metadata(void)
1060 {
1061 static_branch_dec(&ip_tunnel_metadata_cnt);
1062 }
1063 EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata);
1064
1065 /* Returns either the correct skb->protocol value, or 0 if invalid. */
ip_tunnel_parse_protocol(const struct sk_buff * skb)1066 __be16 ip_tunnel_parse_protocol(const struct sk_buff *skb)
1067 {
1068 if (skb_network_header(skb) >= skb->head &&
1069 (skb_network_header(skb) + sizeof(struct iphdr)) <= skb_tail_pointer(skb) &&
1070 ip_hdr(skb)->version == 4)
1071 return htons(ETH_P_IP);
1072 if (skb_network_header(skb) >= skb->head &&
1073 (skb_network_header(skb) + sizeof(struct ipv6hdr)) <= skb_tail_pointer(skb) &&
1074 ipv6_hdr(skb)->version == 6)
1075 return htons(ETH_P_IPV6);
1076 return 0;
1077 }
1078 EXPORT_SYMBOL(ip_tunnel_parse_protocol);
1079
1080 const struct header_ops ip_tunnel_header_ops = { .parse_protocol = ip_tunnel_parse_protocol };
1081 EXPORT_SYMBOL(ip_tunnel_header_ops);
1082