xref: /linux/net/ipv4/ip_tunnel_core.c (revision b4db9f840283caca0d904436f187ef56a9126eaa)
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 
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 
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 
125 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
126 					     gfp_t flags)
127 {
128 	IP_TUNNEL_DECLARE_FLAGS(tun_flags) = { };
129 	struct metadata_dst *res;
130 	struct ip_tunnel_info *dst, *src;
131 
132 	if (!md || md->type != METADATA_IP_TUNNEL ||
133 	    md->u.tun_info.mode & IP_TUNNEL_INFO_TX)
134 		return NULL;
135 
136 	src = &md->u.tun_info;
137 	res = metadata_dst_alloc(src->options_len, METADATA_IP_TUNNEL, flags);
138 	if (!res)
139 		return NULL;
140 
141 	dst = &res->u.tun_info;
142 	dst->key.tun_id = src->key.tun_id;
143 	if (src->mode & IP_TUNNEL_INFO_IPV6)
144 		memcpy(&dst->key.u.ipv6.dst, &src->key.u.ipv6.src,
145 		       sizeof(struct in6_addr));
146 	else
147 		dst->key.u.ipv4.dst = src->key.u.ipv4.src;
148 	ip_tunnel_flags_copy(dst->key.tun_flags, src->key.tun_flags);
149 	dst->mode = src->mode | IP_TUNNEL_INFO_TX;
150 	ip_tunnel_info_opts_set(dst, ip_tunnel_info_opts(src),
151 				src->options_len, tun_flags);
152 
153 	return res;
154 }
155 EXPORT_SYMBOL_GPL(iptunnel_metadata_reply);
156 
157 int iptunnel_handle_offloads(struct sk_buff *skb,
158 			     int gso_type_mask)
159 {
160 	int err;
161 
162 	if (likely(!skb->encapsulation)) {
163 		skb_reset_inner_headers(skb);
164 		skb->encapsulation = 1;
165 	}
166 
167 	if (skb_is_gso(skb)) {
168 		err = skb_header_unclone(skb, GFP_ATOMIC);
169 		if (unlikely(err))
170 			return err;
171 		skb_shinfo(skb)->gso_type |= gso_type_mask;
172 		return 0;
173 	}
174 
175 	if (skb->ip_summed != CHECKSUM_PARTIAL) {
176 		skb->ip_summed = CHECKSUM_NONE;
177 		/* We clear encapsulation here to prevent badly-written
178 		 * drivers potentially deciding to offload an inner checksum
179 		 * if we set CHECKSUM_PARTIAL on the outer header.
180 		 * This should go away when the drivers are all fixed.
181 		 */
182 		skb->encapsulation = 0;
183 	}
184 
185 	return 0;
186 }
187 EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);
188 
189 /**
190  * iptunnel_pmtud_build_icmp() - Build ICMP error message for PMTUD
191  * @skb:	Original packet with L2 header
192  * @mtu:	MTU value for ICMP error
193  *
194  * Return: length on success, negative error code if message couldn't be built.
195  */
196 static int iptunnel_pmtud_build_icmp(struct sk_buff *skb, int mtu)
197 {
198 	const struct iphdr *iph = ip_hdr(skb);
199 	struct icmphdr *icmph;
200 	struct iphdr *niph;
201 	struct ethhdr eh;
202 	int len, err;
203 
204 	if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
205 		return -EINVAL;
206 
207 	skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN);
208 	pskb_pull(skb, ETH_HLEN);
209 	skb_reset_network_header(skb);
210 
211 	err = pskb_trim(skb, 576 - sizeof(*niph) - sizeof(*icmph));
212 	if (err)
213 		return err;
214 
215 	len = skb->len + sizeof(*icmph);
216 	err = skb_cow(skb, sizeof(*niph) + sizeof(*icmph) + ETH_HLEN);
217 	if (err)
218 		return err;
219 
220 	icmph = skb_push(skb, sizeof(*icmph));
221 	*icmph = (struct icmphdr) {
222 		.type			= ICMP_DEST_UNREACH,
223 		.code			= ICMP_FRAG_NEEDED,
224 		.checksum		= 0,
225 		.un.frag.__unused	= 0,
226 		.un.frag.mtu		= htons(mtu),
227 	};
228 	icmph->checksum = csum_fold(skb_checksum(skb, 0, len, 0));
229 	skb_reset_transport_header(skb);
230 
231 	niph = skb_push(skb, sizeof(*niph));
232 	*niph = (struct iphdr) {
233 		.ihl			= sizeof(*niph) / 4u,
234 		.version 		= 4,
235 		.tos 			= 0,
236 		.tot_len		= htons(len + sizeof(*niph)),
237 		.id			= 0,
238 		.frag_off		= htons(IP_DF),
239 		.ttl			= iph->ttl,
240 		.protocol		= IPPROTO_ICMP,
241 		.saddr			= iph->daddr,
242 		.daddr			= iph->saddr,
243 	};
244 	ip_send_check(niph);
245 	skb_reset_network_header(skb);
246 
247 	skb->ip_summed = CHECKSUM_NONE;
248 
249 	eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);
250 	skb_reset_mac_header(skb);
251 
252 	return skb->len;
253 }
254 
255 /**
256  * iptunnel_pmtud_check_icmp() - Trigger ICMP reply if needed and allowed
257  * @skb:	Buffer being sent by encapsulation, L2 headers expected
258  * @mtu:	Network MTU for path
259  *
260  * Return: 0 for no ICMP reply, length if built, negative value on error.
261  */
262 static int iptunnel_pmtud_check_icmp(struct sk_buff *skb, int mtu)
263 {
264 	const struct icmphdr *icmph = icmp_hdr(skb);
265 	const struct iphdr *iph = ip_hdr(skb);
266 
267 	if (mtu < 576 || iph->frag_off != htons(IP_DF))
268 		return 0;
269 
270 	if (ipv4_is_lbcast(iph->daddr)  || ipv4_is_multicast(iph->daddr) ||
271 	    ipv4_is_zeronet(iph->saddr) || ipv4_is_loopback(iph->saddr)  ||
272 	    ipv4_is_lbcast(iph->saddr)  || ipv4_is_multicast(iph->saddr))
273 		return 0;
274 
275 	if (iph->protocol == IPPROTO_ICMP && icmp_is_err(icmph->type))
276 		return 0;
277 
278 	return iptunnel_pmtud_build_icmp(skb, mtu);
279 }
280 
281 #if IS_ENABLED(CONFIG_IPV6)
282 /**
283  * iptunnel_pmtud_build_icmpv6() - Build ICMPv6 error message for PMTUD
284  * @skb:	Original packet with L2 header
285  * @mtu:	MTU value for ICMPv6 error
286  *
287  * Return: length on success, negative error code if message couldn't be built.
288  */
289 static int iptunnel_pmtud_build_icmpv6(struct sk_buff *skb, int mtu)
290 {
291 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
292 	struct icmp6hdr *icmp6h;
293 	struct ipv6hdr *nip6h;
294 	struct ethhdr eh;
295 	int len, err;
296 	__wsum csum;
297 
298 	if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
299 		return -EINVAL;
300 
301 	skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN);
302 	pskb_pull(skb, ETH_HLEN);
303 	skb_reset_network_header(skb);
304 
305 	err = pskb_trim(skb, IPV6_MIN_MTU - sizeof(*nip6h) - sizeof(*icmp6h));
306 	if (err)
307 		return err;
308 
309 	len = skb->len + sizeof(*icmp6h);
310 	err = skb_cow(skb, sizeof(*nip6h) + sizeof(*icmp6h) + ETH_HLEN);
311 	if (err)
312 		return err;
313 
314 	icmp6h = skb_push(skb, sizeof(*icmp6h));
315 	*icmp6h = (struct icmp6hdr) {
316 		.icmp6_type		= ICMPV6_PKT_TOOBIG,
317 		.icmp6_code		= 0,
318 		.icmp6_cksum		= 0,
319 		.icmp6_mtu		= htonl(mtu),
320 	};
321 	skb_reset_transport_header(skb);
322 
323 	nip6h = skb_push(skb, sizeof(*nip6h));
324 	*nip6h = (struct ipv6hdr) {
325 		.priority		= 0,
326 		.version		= 6,
327 		.flow_lbl		= { 0 },
328 		.payload_len		= htons(len),
329 		.nexthdr		= IPPROTO_ICMPV6,
330 		.hop_limit		= ip6h->hop_limit,
331 		.saddr			= ip6h->daddr,
332 		.daddr			= ip6h->saddr,
333 	};
334 	skb_reset_network_header(skb);
335 
336 	csum = skb_checksum(skb, skb_transport_offset(skb), len, 0);
337 	icmp6h->icmp6_cksum = csum_ipv6_magic(&nip6h->saddr, &nip6h->daddr, len,
338 					      IPPROTO_ICMPV6, csum);
339 
340 	skb->ip_summed = CHECKSUM_NONE;
341 
342 	eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);
343 	skb_reset_mac_header(skb);
344 
345 	return skb->len;
346 }
347 
348 /**
349  * iptunnel_pmtud_check_icmpv6() - Trigger ICMPv6 reply if needed and allowed
350  * @skb:	Buffer being sent by encapsulation, L2 headers expected
351  * @mtu:	Network MTU for path
352  *
353  * Return: 0 for no ICMPv6 reply, length if built, negative value on error.
354  */
355 static int iptunnel_pmtud_check_icmpv6(struct sk_buff *skb, int mtu)
356 {
357 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
358 	int stype = ipv6_addr_type(&ip6h->saddr);
359 	u8 proto = ip6h->nexthdr;
360 	__be16 frag_off;
361 	int offset;
362 
363 	if (mtu < IPV6_MIN_MTU)
364 		return 0;
365 
366 	if (stype == IPV6_ADDR_ANY || stype == IPV6_ADDR_MULTICAST ||
367 	    stype == IPV6_ADDR_LOOPBACK)
368 		return 0;
369 
370 	offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &proto,
371 				  &frag_off);
372 	if (offset < 0 || (frag_off & htons(~0x7)))
373 		return 0;
374 
375 	if (proto == IPPROTO_ICMPV6) {
376 		struct icmp6hdr *icmp6h;
377 
378 		if (!pskb_may_pull(skb, skb_network_header(skb) +
379 					offset + 1 - skb->data))
380 			return 0;
381 
382 		icmp6h = (struct icmp6hdr *)(skb_network_header(skb) + offset);
383 		if (icmpv6_is_err(icmp6h->icmp6_type) ||
384 		    icmp6h->icmp6_type == NDISC_REDIRECT)
385 			return 0;
386 	}
387 
388 	return iptunnel_pmtud_build_icmpv6(skb, mtu);
389 }
390 #endif /* IS_ENABLED(CONFIG_IPV6) */
391 
392 /**
393  * skb_tunnel_check_pmtu() - Check, update PMTU and trigger ICMP reply as needed
394  * @skb:	Buffer being sent by encapsulation, L2 headers expected
395  * @encap_dst:	Destination for tunnel encapsulation (outer IP)
396  * @headroom:	Encapsulation header size, bytes
397  * @reply:	Build matching ICMP or ICMPv6 message as a result
398  *
399  * L2 tunnel implementations that can carry IP and can be directly bridged
400  * (currently UDP tunnels) can't always rely on IP forwarding paths to handle
401  * PMTU discovery. In the bridged case, ICMP or ICMPv6 messages need to be built
402  * based on payload and sent back by the encapsulation itself.
403  *
404  * For routable interfaces, we just need to update the PMTU for the destination.
405  *
406  * Return: 0 if ICMP error not needed, length if built, negative value on error
407  */
408 int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst,
409 			  int headroom, bool reply)
410 {
411 	u32 mtu = dst_mtu(encap_dst) - headroom;
412 
413 	if ((skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) ||
414 	    (!skb_is_gso(skb) && (skb->len - skb_network_offset(skb)) <= mtu))
415 		return 0;
416 
417 	skb_dst_update_pmtu_no_confirm(skb, mtu);
418 
419 	if (!reply || skb->pkt_type == PACKET_HOST)
420 		return 0;
421 
422 	if (skb->protocol == htons(ETH_P_IP))
423 		return iptunnel_pmtud_check_icmp(skb, mtu);
424 
425 #if IS_ENABLED(CONFIG_IPV6)
426 	if (skb->protocol == htons(ETH_P_IPV6))
427 		return iptunnel_pmtud_check_icmpv6(skb, mtu);
428 #endif
429 	return 0;
430 }
431 EXPORT_SYMBOL(skb_tunnel_check_pmtu);
432 
433 static const struct nla_policy ip_tun_policy[LWTUNNEL_IP_MAX + 1] = {
434 	[LWTUNNEL_IP_UNSPEC]	= { .strict_start_type = LWTUNNEL_IP_OPTS },
435 	[LWTUNNEL_IP_ID]	= { .type = NLA_U64 },
436 	[LWTUNNEL_IP_DST]	= { .type = NLA_U32 },
437 	[LWTUNNEL_IP_SRC]	= { .type = NLA_U32 },
438 	[LWTUNNEL_IP_TTL]	= { .type = NLA_U8 },
439 	[LWTUNNEL_IP_TOS]	= { .type = NLA_U8 },
440 	[LWTUNNEL_IP_FLAGS]	= { .type = NLA_U16 },
441 	[LWTUNNEL_IP_OPTS]	= { .type = NLA_NESTED },
442 };
443 
444 static const struct nla_policy ip_opts_policy[LWTUNNEL_IP_OPTS_MAX + 1] = {
445 	[LWTUNNEL_IP_OPTS_GENEVE]	= { .type = NLA_NESTED },
446 	[LWTUNNEL_IP_OPTS_VXLAN]	= { .type = NLA_NESTED },
447 	[LWTUNNEL_IP_OPTS_ERSPAN]	= { .type = NLA_NESTED },
448 };
449 
450 static const struct nla_policy
451 geneve_opt_policy[LWTUNNEL_IP_OPT_GENEVE_MAX + 1] = {
452 	[LWTUNNEL_IP_OPT_GENEVE_CLASS]	= { .type = NLA_U16 },
453 	[LWTUNNEL_IP_OPT_GENEVE_TYPE]	= { .type = NLA_U8 },
454 	[LWTUNNEL_IP_OPT_GENEVE_DATA]	= { .type = NLA_BINARY, .len = 128 },
455 };
456 
457 static const struct nla_policy
458 vxlan_opt_policy[LWTUNNEL_IP_OPT_VXLAN_MAX + 1] = {
459 	[LWTUNNEL_IP_OPT_VXLAN_GBP]	= { .type = NLA_U32 },
460 };
461 
462 static const struct nla_policy
463 erspan_opt_policy[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1] = {
464 	[LWTUNNEL_IP_OPT_ERSPAN_VER]	= { .type = NLA_U8 },
465 	[LWTUNNEL_IP_OPT_ERSPAN_INDEX]	= { .type = NLA_U32 },
466 	[LWTUNNEL_IP_OPT_ERSPAN_DIR]	= { .type = NLA_U8 },
467 	[LWTUNNEL_IP_OPT_ERSPAN_HWID]	= { .type = NLA_U8 },
468 };
469 
470 static int ip_tun_parse_opts_geneve(struct nlattr *attr,
471 				    struct ip_tunnel_info *info, int opts_len,
472 				    struct netlink_ext_ack *extack)
473 {
474 	struct nlattr *tb[LWTUNNEL_IP_OPT_GENEVE_MAX + 1];
475 	int data_len, err;
476 
477 	err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_GENEVE_MAX, attr,
478 			       geneve_opt_policy, extack);
479 	if (err)
480 		return err;
481 
482 	if (!tb[LWTUNNEL_IP_OPT_GENEVE_CLASS] ||
483 	    !tb[LWTUNNEL_IP_OPT_GENEVE_TYPE] ||
484 	    !tb[LWTUNNEL_IP_OPT_GENEVE_DATA])
485 		return -EINVAL;
486 
487 	attr = tb[LWTUNNEL_IP_OPT_GENEVE_DATA];
488 	data_len = nla_len(attr);
489 	if (data_len % 4)
490 		return -EINVAL;
491 
492 	if (info) {
493 		struct geneve_opt *opt = ip_tunnel_info_opts(info) + opts_len;
494 
495 		memcpy(opt->opt_data, nla_data(attr), data_len);
496 		opt->length = data_len / 4;
497 		attr = tb[LWTUNNEL_IP_OPT_GENEVE_CLASS];
498 		opt->opt_class = nla_get_be16(attr);
499 		attr = tb[LWTUNNEL_IP_OPT_GENEVE_TYPE];
500 		opt->type = nla_get_u8(attr);
501 		__set_bit(IP_TUNNEL_GENEVE_OPT_BIT, info->key.tun_flags);
502 	}
503 
504 	return sizeof(struct geneve_opt) + data_len;
505 }
506 
507 static int ip_tun_parse_opts_vxlan(struct nlattr *attr,
508 				   struct ip_tunnel_info *info, int opts_len,
509 				   struct netlink_ext_ack *extack)
510 {
511 	struct nlattr *tb[LWTUNNEL_IP_OPT_VXLAN_MAX + 1];
512 	int err;
513 
514 	err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_VXLAN_MAX, attr,
515 			       vxlan_opt_policy, extack);
516 	if (err)
517 		return err;
518 
519 	if (!tb[LWTUNNEL_IP_OPT_VXLAN_GBP])
520 		return -EINVAL;
521 
522 	if (info) {
523 		struct vxlan_metadata *md =
524 			ip_tunnel_info_opts(info) + opts_len;
525 
526 		attr = tb[LWTUNNEL_IP_OPT_VXLAN_GBP];
527 		md->gbp = nla_get_u32(attr);
528 		md->gbp &= VXLAN_GBP_MASK;
529 		__set_bit(IP_TUNNEL_VXLAN_OPT_BIT, info->key.tun_flags);
530 	}
531 
532 	return sizeof(struct vxlan_metadata);
533 }
534 
535 static int ip_tun_parse_opts_erspan(struct nlattr *attr,
536 				    struct ip_tunnel_info *info, int opts_len,
537 				    struct netlink_ext_ack *extack)
538 {
539 	struct nlattr *tb[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1];
540 	int err;
541 	u8 ver;
542 
543 	err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_ERSPAN_MAX, attr,
544 			       erspan_opt_policy, extack);
545 	if (err)
546 		return err;
547 
548 	if (!tb[LWTUNNEL_IP_OPT_ERSPAN_VER])
549 		return -EINVAL;
550 
551 	ver = nla_get_u8(tb[LWTUNNEL_IP_OPT_ERSPAN_VER]);
552 	if (ver == 1) {
553 		if (!tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX])
554 			return -EINVAL;
555 	} else if (ver == 2) {
556 		if (!tb[LWTUNNEL_IP_OPT_ERSPAN_DIR] ||
557 		    !tb[LWTUNNEL_IP_OPT_ERSPAN_HWID])
558 			return -EINVAL;
559 	} else {
560 		return -EINVAL;
561 	}
562 
563 	if (info) {
564 		struct erspan_metadata *md =
565 			ip_tunnel_info_opts(info) + opts_len;
566 
567 		md->version = ver;
568 		if (ver == 1) {
569 			attr = tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX];
570 			md->u.index = nla_get_be32(attr);
571 		} else {
572 			attr = tb[LWTUNNEL_IP_OPT_ERSPAN_DIR];
573 			md->u.md2.dir = nla_get_u8(attr);
574 			attr = tb[LWTUNNEL_IP_OPT_ERSPAN_HWID];
575 			set_hwid(&md->u.md2, nla_get_u8(attr));
576 		}
577 
578 		__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT, info->key.tun_flags);
579 	}
580 
581 	return sizeof(struct erspan_metadata);
582 }
583 
584 static int ip_tun_parse_opts(struct nlattr *attr, struct ip_tunnel_info *info,
585 			     struct netlink_ext_ack *extack)
586 {
587 	int err, rem, opt_len, opts_len = 0;
588 	struct nlattr *nla;
589 	u32 type = 0;
590 
591 	if (!attr)
592 		return 0;
593 
594 	err = nla_validate(nla_data(attr), nla_len(attr), LWTUNNEL_IP_OPTS_MAX,
595 			   ip_opts_policy, extack);
596 	if (err)
597 		return err;
598 
599 	nla_for_each_attr(nla, nla_data(attr), nla_len(attr), rem) {
600 		switch (nla_type(nla)) {
601 		case LWTUNNEL_IP_OPTS_GENEVE:
602 			if (type && type != IP_TUNNEL_GENEVE_OPT_BIT)
603 				return -EINVAL;
604 			opt_len = ip_tun_parse_opts_geneve(nla, info, opts_len,
605 							   extack);
606 			if (opt_len < 0)
607 				return opt_len;
608 			opts_len += opt_len;
609 			if (opts_len > IP_TUNNEL_OPTS_MAX)
610 				return -EINVAL;
611 			type = IP_TUNNEL_GENEVE_OPT_BIT;
612 			break;
613 		case LWTUNNEL_IP_OPTS_VXLAN:
614 			if (type)
615 				return -EINVAL;
616 			opt_len = ip_tun_parse_opts_vxlan(nla, info, opts_len,
617 							  extack);
618 			if (opt_len < 0)
619 				return opt_len;
620 			opts_len += opt_len;
621 			type = IP_TUNNEL_VXLAN_OPT_BIT;
622 			break;
623 		case LWTUNNEL_IP_OPTS_ERSPAN:
624 			if (type)
625 				return -EINVAL;
626 			opt_len = ip_tun_parse_opts_erspan(nla, info, opts_len,
627 							   extack);
628 			if (opt_len < 0)
629 				return opt_len;
630 			opts_len += opt_len;
631 			type = IP_TUNNEL_ERSPAN_OPT_BIT;
632 			break;
633 		default:
634 			return -EINVAL;
635 		}
636 	}
637 
638 	return opts_len;
639 }
640 
641 static int ip_tun_get_optlen(struct nlattr *attr,
642 			     struct netlink_ext_ack *extack)
643 {
644 	return ip_tun_parse_opts(attr, NULL, extack);
645 }
646 
647 static int ip_tun_set_opts(struct nlattr *attr, struct ip_tunnel_info *info,
648 			   struct netlink_ext_ack *extack)
649 {
650 	return ip_tun_parse_opts(attr, info, extack);
651 }
652 
653 static int ip_tun_build_state(struct net *net, struct nlattr *attr,
654 			      unsigned int family, const void *cfg,
655 			      struct lwtunnel_state **ts,
656 			      struct netlink_ext_ack *extack)
657 {
658 	struct nlattr *tb[LWTUNNEL_IP_MAX + 1];
659 	struct lwtunnel_state *new_state;
660 	struct ip_tunnel_info *tun_info;
661 	int err, opt_len;
662 
663 	err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP_MAX, attr,
664 					  ip_tun_policy, extack);
665 	if (err < 0)
666 		return err;
667 
668 	opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP_OPTS], extack);
669 	if (opt_len < 0)
670 		return opt_len;
671 
672 	new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len);
673 	if (!new_state)
674 		return -ENOMEM;
675 
676 	new_state->type = LWTUNNEL_ENCAP_IP;
677 
678 	tun_info = lwt_tun_info(new_state);
679 
680 	err = ip_tun_set_opts(tb[LWTUNNEL_IP_OPTS], tun_info, extack);
681 	if (err < 0) {
682 		lwtstate_free(new_state);
683 		return err;
684 	}
685 
686 #ifdef CONFIG_DST_CACHE
687 	err = dst_cache_init(&tun_info->dst_cache, GFP_KERNEL);
688 	if (err) {
689 		lwtstate_free(new_state);
690 		return err;
691 	}
692 #endif
693 
694 	if (tb[LWTUNNEL_IP_ID])
695 		tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP_ID]);
696 
697 	if (tb[LWTUNNEL_IP_DST])
698 		tun_info->key.u.ipv4.dst = nla_get_in_addr(tb[LWTUNNEL_IP_DST]);
699 
700 	if (tb[LWTUNNEL_IP_SRC])
701 		tun_info->key.u.ipv4.src = nla_get_in_addr(tb[LWTUNNEL_IP_SRC]);
702 
703 	if (tb[LWTUNNEL_IP_TTL])
704 		tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP_TTL]);
705 
706 	if (tb[LWTUNNEL_IP_TOS])
707 		tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP_TOS]);
708 
709 	if (tb[LWTUNNEL_IP_FLAGS]) {
710 		IP_TUNNEL_DECLARE_FLAGS(flags);
711 
712 		ip_tunnel_flags_from_be16(flags,
713 					  nla_get_be16(tb[LWTUNNEL_IP_FLAGS]));
714 		ip_tunnel_clear_options_present(flags);
715 
716 		ip_tunnel_flags_or(tun_info->key.tun_flags,
717 				   tun_info->key.tun_flags, flags);
718 	}
719 
720 	tun_info->mode = IP_TUNNEL_INFO_TX;
721 	tun_info->options_len = opt_len;
722 
723 	*ts = new_state;
724 
725 	return 0;
726 }
727 
728 static void ip_tun_destroy_state(struct lwtunnel_state *lwtstate)
729 {
730 #ifdef CONFIG_DST_CACHE
731 	struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
732 
733 	dst_cache_destroy(&tun_info->dst_cache);
734 #endif
735 }
736 
737 static int ip_tun_fill_encap_opts_geneve(struct sk_buff *skb,
738 					 struct ip_tunnel_info *tun_info)
739 {
740 	struct geneve_opt *opt;
741 	struct nlattr *nest;
742 	int offset = 0;
743 
744 	nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_GENEVE);
745 	if (!nest)
746 		return -ENOMEM;
747 
748 	while (tun_info->options_len > offset) {
749 		opt = ip_tunnel_info_opts(tun_info) + offset;
750 		if (nla_put_be16(skb, LWTUNNEL_IP_OPT_GENEVE_CLASS,
751 				 opt->opt_class) ||
752 		    nla_put_u8(skb, LWTUNNEL_IP_OPT_GENEVE_TYPE, opt->type) ||
753 		    nla_put(skb, LWTUNNEL_IP_OPT_GENEVE_DATA, opt->length * 4,
754 			    opt->opt_data)) {
755 			nla_nest_cancel(skb, nest);
756 			return -ENOMEM;
757 		}
758 		offset += sizeof(*opt) + opt->length * 4;
759 	}
760 
761 	nla_nest_end(skb, nest);
762 	return 0;
763 }
764 
765 static int ip_tun_fill_encap_opts_vxlan(struct sk_buff *skb,
766 					struct ip_tunnel_info *tun_info)
767 {
768 	struct vxlan_metadata *md;
769 	struct nlattr *nest;
770 
771 	nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_VXLAN);
772 	if (!nest)
773 		return -ENOMEM;
774 
775 	md = ip_tunnel_info_opts(tun_info);
776 	if (nla_put_u32(skb, LWTUNNEL_IP_OPT_VXLAN_GBP, md->gbp)) {
777 		nla_nest_cancel(skb, nest);
778 		return -ENOMEM;
779 	}
780 
781 	nla_nest_end(skb, nest);
782 	return 0;
783 }
784 
785 static int ip_tun_fill_encap_opts_erspan(struct sk_buff *skb,
786 					 struct ip_tunnel_info *tun_info)
787 {
788 	struct erspan_metadata *md;
789 	struct nlattr *nest;
790 
791 	nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_ERSPAN);
792 	if (!nest)
793 		return -ENOMEM;
794 
795 	md = ip_tunnel_info_opts(tun_info);
796 	if (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_VER, md->version))
797 		goto err;
798 
799 	if (md->version == 1 &&
800 	    nla_put_be32(skb, LWTUNNEL_IP_OPT_ERSPAN_INDEX, md->u.index))
801 		goto err;
802 
803 	if (md->version == 2 &&
804 	    (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_DIR, md->u.md2.dir) ||
805 	     nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_HWID,
806 			get_hwid(&md->u.md2))))
807 		goto err;
808 
809 	nla_nest_end(skb, nest);
810 	return 0;
811 err:
812 	nla_nest_cancel(skb, nest);
813 	return -ENOMEM;
814 }
815 
816 static int ip_tun_fill_encap_opts(struct sk_buff *skb, int type,
817 				  struct ip_tunnel_info *tun_info)
818 {
819 	struct nlattr *nest;
820 	int err = 0;
821 
822 	if (!ip_tunnel_is_options_present(tun_info->key.tun_flags))
823 		return 0;
824 
825 	nest = nla_nest_start_noflag(skb, type);
826 	if (!nest)
827 		return -ENOMEM;
828 
829 	if (test_bit(IP_TUNNEL_GENEVE_OPT_BIT, tun_info->key.tun_flags))
830 		err = ip_tun_fill_encap_opts_geneve(skb, tun_info);
831 	else if (test_bit(IP_TUNNEL_VXLAN_OPT_BIT, tun_info->key.tun_flags))
832 		err = ip_tun_fill_encap_opts_vxlan(skb, tun_info);
833 	else if (test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, tun_info->key.tun_flags))
834 		err = ip_tun_fill_encap_opts_erspan(skb, tun_info);
835 
836 	if (err) {
837 		nla_nest_cancel(skb, nest);
838 		return err;
839 	}
840 
841 	nla_nest_end(skb, nest);
842 	return 0;
843 }
844 
845 static int ip_tun_fill_encap_info(struct sk_buff *skb,
846 				  struct lwtunnel_state *lwtstate)
847 {
848 	struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
849 
850 	if (nla_put_be64(skb, LWTUNNEL_IP_ID, tun_info->key.tun_id,
851 			 LWTUNNEL_IP_PAD) ||
852 	    nla_put_in_addr(skb, LWTUNNEL_IP_DST, tun_info->key.u.ipv4.dst) ||
853 	    nla_put_in_addr(skb, LWTUNNEL_IP_SRC, tun_info->key.u.ipv4.src) ||
854 	    nla_put_u8(skb, LWTUNNEL_IP_TOS, tun_info->key.tos) ||
855 	    nla_put_u8(skb, LWTUNNEL_IP_TTL, tun_info->key.ttl) ||
856 	    nla_put_be16(skb, LWTUNNEL_IP_FLAGS,
857 			 ip_tunnel_flags_to_be16(tun_info->key.tun_flags)) ||
858 	    ip_tun_fill_encap_opts(skb, LWTUNNEL_IP_OPTS, tun_info))
859 		return -ENOMEM;
860 
861 	return 0;
862 }
863 
864 static int ip_tun_opts_nlsize(struct ip_tunnel_info *info)
865 {
866 	int opt_len;
867 
868 	if (!ip_tunnel_is_options_present(info->key.tun_flags))
869 		return 0;
870 
871 	opt_len = nla_total_size(0);		/* LWTUNNEL_IP_OPTS */
872 	if (test_bit(IP_TUNNEL_GENEVE_OPT_BIT, info->key.tun_flags)) {
873 		struct geneve_opt *opt;
874 		int offset = 0;
875 
876 		opt_len += nla_total_size(0);	/* LWTUNNEL_IP_OPTS_GENEVE */
877 		while (info->options_len > offset) {
878 			opt = ip_tunnel_info_opts(info) + offset;
879 			opt_len += nla_total_size(2)	/* OPT_GENEVE_CLASS */
880 				   + nla_total_size(1)	/* OPT_GENEVE_TYPE */
881 				   + nla_total_size(opt->length * 4);
882 							/* OPT_GENEVE_DATA */
883 			offset += sizeof(*opt) + opt->length * 4;
884 		}
885 	} else if (test_bit(IP_TUNNEL_VXLAN_OPT_BIT, info->key.tun_flags)) {
886 		opt_len += nla_total_size(0)	/* LWTUNNEL_IP_OPTS_VXLAN */
887 			   + nla_total_size(4);	/* OPT_VXLAN_GBP */
888 	} else if (test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, info->key.tun_flags)) {
889 		struct erspan_metadata *md = ip_tunnel_info_opts(info);
890 
891 		opt_len += nla_total_size(0)	/* LWTUNNEL_IP_OPTS_ERSPAN */
892 			   + nla_total_size(1)	/* OPT_ERSPAN_VER */
893 			   + (md->version == 1 ? nla_total_size(4)
894 						/* OPT_ERSPAN_INDEX (v1) */
895 					       : nla_total_size(1) +
896 						 nla_total_size(1));
897 						/* OPT_ERSPAN_DIR + HWID (v2) */
898 	}
899 
900 	return opt_len;
901 }
902 
903 static int ip_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
904 {
905 	return nla_total_size_64bit(8)	/* LWTUNNEL_IP_ID */
906 		+ nla_total_size(4)	/* LWTUNNEL_IP_DST */
907 		+ nla_total_size(4)	/* LWTUNNEL_IP_SRC */
908 		+ nla_total_size(1)	/* LWTUNNEL_IP_TOS */
909 		+ nla_total_size(1)	/* LWTUNNEL_IP_TTL */
910 		+ nla_total_size(2)	/* LWTUNNEL_IP_FLAGS */
911 		+ ip_tun_opts_nlsize(lwt_tun_info(lwtstate));
912 					/* LWTUNNEL_IP_OPTS */
913 }
914 
915 static int ip_tun_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
916 {
917 	struct ip_tunnel_info *info_a = lwt_tun_info(a);
918 	struct ip_tunnel_info *info_b = lwt_tun_info(b);
919 
920 	return memcmp(info_a, info_b, sizeof(info_a->key)) ||
921 	       info_a->mode != info_b->mode ||
922 	       info_a->options_len != info_b->options_len ||
923 	       memcmp(ip_tunnel_info_opts(info_a),
924 		      ip_tunnel_info_opts(info_b), info_a->options_len);
925 }
926 
927 static const struct lwtunnel_encap_ops ip_tun_lwt_ops = {
928 	.build_state = ip_tun_build_state,
929 	.destroy_state = ip_tun_destroy_state,
930 	.fill_encap = ip_tun_fill_encap_info,
931 	.get_encap_size = ip_tun_encap_nlsize,
932 	.cmp_encap = ip_tun_cmp_encap,
933 	.owner = THIS_MODULE,
934 };
935 
936 static const struct nla_policy ip6_tun_policy[LWTUNNEL_IP6_MAX + 1] = {
937 	[LWTUNNEL_IP6_UNSPEC]	= { .strict_start_type = LWTUNNEL_IP6_OPTS },
938 	[LWTUNNEL_IP6_ID]		= { .type = NLA_U64 },
939 	[LWTUNNEL_IP6_DST]		= { .len = sizeof(struct in6_addr) },
940 	[LWTUNNEL_IP6_SRC]		= { .len = sizeof(struct in6_addr) },
941 	[LWTUNNEL_IP6_HOPLIMIT]		= { .type = NLA_U8 },
942 	[LWTUNNEL_IP6_TC]		= { .type = NLA_U8 },
943 	[LWTUNNEL_IP6_FLAGS]		= { .type = NLA_U16 },
944 	[LWTUNNEL_IP6_OPTS]		= { .type = NLA_NESTED },
945 };
946 
947 static int ip6_tun_build_state(struct net *net, struct nlattr *attr,
948 			       unsigned int family, const void *cfg,
949 			       struct lwtunnel_state **ts,
950 			       struct netlink_ext_ack *extack)
951 {
952 	struct nlattr *tb[LWTUNNEL_IP6_MAX + 1];
953 	struct lwtunnel_state *new_state;
954 	struct ip_tunnel_info *tun_info;
955 	int err, opt_len;
956 
957 	err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP6_MAX, attr,
958 					  ip6_tun_policy, extack);
959 	if (err < 0)
960 		return err;
961 
962 	opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP6_OPTS], extack);
963 	if (opt_len < 0)
964 		return opt_len;
965 
966 	new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len);
967 	if (!new_state)
968 		return -ENOMEM;
969 
970 	new_state->type = LWTUNNEL_ENCAP_IP6;
971 
972 	tun_info = lwt_tun_info(new_state);
973 
974 	err = ip_tun_set_opts(tb[LWTUNNEL_IP6_OPTS], tun_info, extack);
975 	if (err < 0) {
976 		lwtstate_free(new_state);
977 		return err;
978 	}
979 
980 	if (tb[LWTUNNEL_IP6_ID])
981 		tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP6_ID]);
982 
983 	if (tb[LWTUNNEL_IP6_DST])
984 		tun_info->key.u.ipv6.dst = nla_get_in6_addr(tb[LWTUNNEL_IP6_DST]);
985 
986 	if (tb[LWTUNNEL_IP6_SRC])
987 		tun_info->key.u.ipv6.src = nla_get_in6_addr(tb[LWTUNNEL_IP6_SRC]);
988 
989 	if (tb[LWTUNNEL_IP6_HOPLIMIT])
990 		tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP6_HOPLIMIT]);
991 
992 	if (tb[LWTUNNEL_IP6_TC])
993 		tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP6_TC]);
994 
995 	if (tb[LWTUNNEL_IP6_FLAGS]) {
996 		IP_TUNNEL_DECLARE_FLAGS(flags);
997 		__be16 data;
998 
999 		data = nla_get_be16(tb[LWTUNNEL_IP6_FLAGS]);
1000 		ip_tunnel_flags_from_be16(flags, data);
1001 		ip_tunnel_clear_options_present(flags);
1002 
1003 		ip_tunnel_flags_or(tun_info->key.tun_flags,
1004 				   tun_info->key.tun_flags, flags);
1005 	}
1006 
1007 	tun_info->mode = IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_IPV6;
1008 	tun_info->options_len = opt_len;
1009 
1010 	*ts = new_state;
1011 
1012 	return 0;
1013 }
1014 
1015 static int ip6_tun_fill_encap_info(struct sk_buff *skb,
1016 				   struct lwtunnel_state *lwtstate)
1017 {
1018 	struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
1019 
1020 	if (nla_put_be64(skb, LWTUNNEL_IP6_ID, tun_info->key.tun_id,
1021 			 LWTUNNEL_IP6_PAD) ||
1022 	    nla_put_in6_addr(skb, LWTUNNEL_IP6_DST, &tun_info->key.u.ipv6.dst) ||
1023 	    nla_put_in6_addr(skb, LWTUNNEL_IP6_SRC, &tun_info->key.u.ipv6.src) ||
1024 	    nla_put_u8(skb, LWTUNNEL_IP6_TC, tun_info->key.tos) ||
1025 	    nla_put_u8(skb, LWTUNNEL_IP6_HOPLIMIT, tun_info->key.ttl) ||
1026 	    nla_put_be16(skb, LWTUNNEL_IP6_FLAGS,
1027 			 ip_tunnel_flags_to_be16(tun_info->key.tun_flags)) ||
1028 	    ip_tun_fill_encap_opts(skb, LWTUNNEL_IP6_OPTS, tun_info))
1029 		return -ENOMEM;
1030 
1031 	return 0;
1032 }
1033 
1034 static int ip6_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
1035 {
1036 	return nla_total_size_64bit(8)	/* LWTUNNEL_IP6_ID */
1037 		+ nla_total_size(16)	/* LWTUNNEL_IP6_DST */
1038 		+ nla_total_size(16)	/* LWTUNNEL_IP6_SRC */
1039 		+ nla_total_size(1)	/* LWTUNNEL_IP6_HOPLIMIT */
1040 		+ nla_total_size(1)	/* LWTUNNEL_IP6_TC */
1041 		+ nla_total_size(2)	/* LWTUNNEL_IP6_FLAGS */
1042 		+ ip_tun_opts_nlsize(lwt_tun_info(lwtstate));
1043 					/* LWTUNNEL_IP6_OPTS */
1044 }
1045 
1046 static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = {
1047 	.build_state = ip6_tun_build_state,
1048 	.fill_encap = ip6_tun_fill_encap_info,
1049 	.get_encap_size = ip6_tun_encap_nlsize,
1050 	.cmp_encap = ip_tun_cmp_encap,
1051 	.owner = THIS_MODULE,
1052 };
1053 
1054 void __init ip_tunnel_core_init(void)
1055 {
1056 	/* If you land here, make sure whether increasing ip_tunnel_info's
1057 	 * options_len is a reasonable choice with its usage in front ends
1058 	 * (f.e., it's part of flow keys, etc).
1059 	 */
1060 	BUILD_BUG_ON(IP_TUNNEL_OPTS_MAX != 255);
1061 
1062 	lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP);
1063 	lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6);
1064 }
1065 
1066 DEFINE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
1067 EXPORT_SYMBOL(ip_tunnel_metadata_cnt);
1068 
1069 void ip_tunnel_need_metadata(void)
1070 {
1071 	static_branch_inc(&ip_tunnel_metadata_cnt);
1072 }
1073 EXPORT_SYMBOL_GPL(ip_tunnel_need_metadata);
1074 
1075 void ip_tunnel_unneed_metadata(void)
1076 {
1077 	static_branch_dec(&ip_tunnel_metadata_cnt);
1078 }
1079 EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata);
1080 
1081 /* Returns either the correct skb->protocol value, or 0 if invalid. */
1082 __be16 ip_tunnel_parse_protocol(const struct sk_buff *skb)
1083 {
1084 	if (skb_network_header(skb) >= skb->head &&
1085 	    (skb_network_header(skb) + sizeof(struct iphdr)) <= skb_tail_pointer(skb) &&
1086 	    ip_hdr(skb)->version == 4)
1087 		return htons(ETH_P_IP);
1088 	if (skb_network_header(skb) >= skb->head &&
1089 	    (skb_network_header(skb) + sizeof(struct ipv6hdr)) <= skb_tail_pointer(skb) &&
1090 	    ipv6_hdr(skb)->version == 6)
1091 		return htons(ETH_P_IPV6);
1092 	return 0;
1093 }
1094 EXPORT_SYMBOL(ip_tunnel_parse_protocol);
1095 
1096 const struct header_ops ip_tunnel_header_ops = { .parse_protocol = ip_tunnel_parse_protocol };
1097 EXPORT_SYMBOL(ip_tunnel_header_ops);
1098 
1099 /* This function returns true when ENCAP attributes are present in the nl msg */
1100 bool ip_tunnel_netlink_encap_parms(struct nlattr *data[],
1101 				   struct ip_tunnel_encap *encap)
1102 {
1103 	bool ret = false;
1104 
1105 	memset(encap, 0, sizeof(*encap));
1106 
1107 	if (!data)
1108 		return ret;
1109 
1110 	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1111 		ret = true;
1112 		encap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1113 	}
1114 
1115 	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1116 		ret = true;
1117 		encap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1118 	}
1119 
1120 	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1121 		ret = true;
1122 		encap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1123 	}
1124 
1125 	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1126 		ret = true;
1127 		encap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1128 	}
1129 
1130 	return ret;
1131 }
1132 EXPORT_SYMBOL_GPL(ip_tunnel_netlink_encap_parms);
1133 
1134 void ip_tunnel_netlink_parms(struct nlattr *data[],
1135 			     struct ip_tunnel_parm_kern *parms)
1136 {
1137 	if (data[IFLA_IPTUN_LINK])
1138 		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1139 
1140 	if (data[IFLA_IPTUN_LOCAL])
1141 		parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1142 
1143 	if (data[IFLA_IPTUN_REMOTE])
1144 		parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1145 
1146 	if (data[IFLA_IPTUN_TTL]) {
1147 		parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1148 		if (parms->iph.ttl)
1149 			parms->iph.frag_off = htons(IP_DF);
1150 	}
1151 
1152 	if (data[IFLA_IPTUN_TOS])
1153 		parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1154 
1155 	if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1156 		parms->iph.frag_off = htons(IP_DF);
1157 
1158 	if (data[IFLA_IPTUN_FLAGS]) {
1159 		__be16 flags;
1160 
1161 		flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1162 		ip_tunnel_flags_from_be16(parms->i_flags, flags);
1163 	}
1164 
1165 	if (data[IFLA_IPTUN_PROTO])
1166 		parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1167 }
1168 EXPORT_SYMBOL_GPL(ip_tunnel_netlink_parms);
1169