xref: /linux/include/net/ip_tunnels.h (revision 57885276cc16a2e2b76282c808a4e84cbecb3aae)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __NET_IP_TUNNELS_H
3 #define __NET_IP_TUNNELS_H 1
4 
5 #include <linux/if_tunnel.h>
6 #include <linux/netdevice.h>
7 #include <linux/skbuff.h>
8 #include <linux/socket.h>
9 #include <linux/types.h>
10 #include <linux/u64_stats_sync.h>
11 #include <linux/bitops.h>
12 
13 #include <net/dsfield.h>
14 #include <net/flow.h>
15 #include <net/gro_cells.h>
16 #include <net/inet_dscp.h>
17 #include <net/inet_ecn.h>
18 #include <net/netns/generic.h>
19 #include <net/rtnetlink.h>
20 #include <net/lwtunnel.h>
21 #include <net/dst_cache.h>
22 #include <net/netdev_lock.h>
23 
24 #if IS_ENABLED(CONFIG_IPV6)
25 #include <net/ipv6.h>
26 #include <net/ip6_fib.h>
27 #include <net/ip6_route.h>
28 #endif
29 
30 /* Recursion limit for tunnel xmit to detect routing loops.
31  * Unlike XMIT_RECURSION_LIMIT (8) used in the no-qdisc path, tunnel
32  * recursion involves route lookups and full IP output, consuming much
33  * more stack per level, so a lower limit is needed.
34  */
35 #define IP_TUNNEL_RECURSION_LIMIT	4
36 
37 /* Keep error state on tunnel for 30 sec */
38 #define IPTUNNEL_ERR_TIMEO	(30*HZ)
39 
40 /* Used to memset ip_tunnel padding. */
41 #define IP_TUNNEL_KEY_SIZE	offsetofend(struct ip_tunnel_key, tp_dst)
42 
43 /* Used to memset ipv4 address padding. */
44 #define IP_TUNNEL_KEY_IPV4_PAD	offsetofend(struct ip_tunnel_key, u.ipv4.dst)
45 #define IP_TUNNEL_KEY_IPV4_PAD_LEN				\
46 	(sizeof_field(struct ip_tunnel_key, u) -		\
47 	 sizeof_field(struct ip_tunnel_key, u.ipv4))
48 
49 #define __ipt_flag_op(op, ...)					\
50 	op(__VA_ARGS__, __IP_TUNNEL_FLAG_NUM)
51 
52 #define IP_TUNNEL_DECLARE_FLAGS(...)				\
53 	__ipt_flag_op(DECLARE_BITMAP, __VA_ARGS__)
54 
55 #define ip_tunnel_flags_zero(...)	__ipt_flag_op(bitmap_zero, __VA_ARGS__)
56 #define ip_tunnel_flags_copy(...)	__ipt_flag_op(bitmap_copy, __VA_ARGS__)
57 #define ip_tunnel_flags_and(...)	__ipt_flag_op(bitmap_and, __VA_ARGS__)
58 #define ip_tunnel_flags_or(...)		__ipt_flag_op(bitmap_or, __VA_ARGS__)
59 
60 #define ip_tunnel_flags_empty(...)				\
61 	__ipt_flag_op(bitmap_empty, __VA_ARGS__)
62 #define ip_tunnel_flags_intersect(...)				\
63 	__ipt_flag_op(bitmap_intersects, __VA_ARGS__)
64 #define ip_tunnel_flags_subset(...)				\
65 	__ipt_flag_op(bitmap_subset, __VA_ARGS__)
66 
67 struct ip_tunnel_key {
68 	__be64			tun_id;
69 	union {
70 		struct {
71 			__be32	src;
72 			__be32	dst;
73 		} ipv4;
74 		struct {
75 			struct in6_addr src;
76 			struct in6_addr dst;
77 		} ipv6;
78 	} u;
79 	IP_TUNNEL_DECLARE_FLAGS(tun_flags);
80 	__be32			label;		/* Flow Label for IPv6 */
81 	u32			nhid;
82 	u8			tos;		/* TOS for IPv4, TC for IPv6 */
83 	u8			ttl;		/* TTL for IPv4, HL for IPv6 */
84 	__be16			tp_src;
85 	__be16			tp_dst;
86 	__u8			flow_flags;
87 };
88 
89 struct ip_tunnel_encap {
90 	u16			type;
91 	u16			flags;
92 	__be16			sport;
93 	__be16			dport;
94 };
95 
96 /* Flags for ip_tunnel_info mode. */
97 #define IP_TUNNEL_INFO_TX	0x01	/* represents tx tunnel parameters */
98 #define IP_TUNNEL_INFO_IPV6	0x02	/* key contains IPv6 addresses */
99 #define IP_TUNNEL_INFO_BRIDGE	0x04	/* represents a bridged tunnel id */
100 
101 /* Maximum tunnel options length. */
102 #define IP_TUNNEL_OPTS_MAX					\
103 	GENMASK((sizeof_field(struct ip_tunnel_info,		\
104 			      options_len) * BITS_PER_BYTE) - 1, 0)
105 
106 #define ip_tunnel_info_opts(info)				\
107 	_Generic(info,						\
108 		 const struct ip_tunnel_info * : ((const void *)(info)->options),\
109 		 struct ip_tunnel_info * : ((void *)(info)->options)\
110 	)
111 
112 struct ip_tunnel_info {
113 	struct ip_tunnel_key	key;
114 	struct ip_tunnel_encap	encap;
115 #ifdef CONFIG_DST_CACHE
116 	struct dst_cache	dst_cache;
117 #endif
118 	u8			options_len;
119 	u8			mode;
120 	u8			options[] __aligned_largest __counted_by(options_len);
121 };
122 
123 /* 6rd prefix/relay information */
124 #ifdef CONFIG_IPV6_SIT_6RD
125 struct ip_tunnel_6rd_parm {
126 	struct in6_addr		prefix;
127 	__be32			relay_prefix;
128 	u16			prefixlen;
129 	u16			relay_prefixlen;
130 };
131 #endif
132 
133 struct ip_tunnel_prl_entry {
134 	struct ip_tunnel_prl_entry __rcu *next;
135 	__be32				addr;
136 	u16				flags;
137 	struct rcu_head			rcu_head;
138 };
139 
140 struct metadata_dst;
141 
142 /* Kernel-side variant of ip_tunnel_parm */
143 struct ip_tunnel_parm_kern {
144 	char			name[IFNAMSIZ];
145 	IP_TUNNEL_DECLARE_FLAGS(i_flags);
146 	IP_TUNNEL_DECLARE_FLAGS(o_flags);
147 	__be32			i_key;
148 	__be32			o_key;
149 	int			link;
150 	struct iphdr		iph;
151 };
152 
153 struct ip_tunnel {
154 	struct ip_tunnel __rcu	*next;
155 	struct hlist_node hash_node;
156 
157 	struct net_device	*dev;
158 	netdevice_tracker	dev_tracker;
159 
160 	struct net		*net;	/* netns for packet i/o */
161 
162 	unsigned long	err_time;	/* Time when the last ICMP error
163 					 * arrived */
164 	int		err_count;	/* Number of arrived ICMP errors */
165 
166 	/* These four fields used only by GRE */
167 	u32		i_seqno;	/* The last seen seqno	*/
168 	atomic_t	o_seqno;	/* The last output seqno */
169 	int		tun_hlen;	/* Precalculated header length */
170 
171 	/* These four fields used only by ERSPAN */
172 	u32		index;		/* ERSPAN type II index */
173 	u8		erspan_ver;	/* ERSPAN version */
174 	u8		dir;		/* ERSPAN direction */
175 	u16		hwid;		/* ERSPAN hardware ID */
176 
177 	struct dst_cache dst_cache;
178 
179 	struct ip_tunnel_parm_kern parms;
180 
181 	int		mlink;
182 	int		encap_hlen;	/* Encap header length (FOU,GUE) */
183 	int		hlen;		/* tun_hlen + encap_hlen */
184 	struct ip_tunnel_encap encap;
185 
186 	/* for SIT */
187 #ifdef CONFIG_IPV6_SIT_6RD
188 	struct ip_tunnel_6rd_parm ip6rd;
189 #endif
190 	struct ip_tunnel_prl_entry __rcu *prl;	/* potential router list */
191 	unsigned int		prl_count;	/* # of entries in PRL */
192 	unsigned int		ip_tnl_net_id;
193 	struct gro_cells	gro_cells;
194 	__u32			fwmark;
195 	bool			collect_md;
196 	bool			ignore_df;
197 };
198 
199 struct tnl_ptk_info {
200 	IP_TUNNEL_DECLARE_FLAGS(flags);
201 	__be16 proto;
202 	__be32 key;
203 	__be32 seq;
204 	int hdr_len;
205 };
206 
207 #define PACKET_RCVD	0
208 #define PACKET_REJECT	1
209 #define PACKET_NEXT	2
210 
211 #define IP_TNL_HASH_BITS   7
212 #define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
213 
214 struct ip_tunnel_net {
215 	struct net_device *fb_tunnel_dev;
216 	struct rtnl_link_ops *rtnl_link_ops;
217 	struct hlist_head tunnels[IP_TNL_HASH_SIZE];
218 	struct ip_tunnel __rcu *collect_md_tun;
219 	int type;
220 };
221 
222 static inline void ip_tunnel_set_options_present(unsigned long *flags)
223 {
224 	IP_TUNNEL_DECLARE_FLAGS(present) = { };
225 
226 	__set_bit(IP_TUNNEL_GENEVE_OPT_BIT, present);
227 	__set_bit(IP_TUNNEL_VXLAN_OPT_BIT, present);
228 	__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT, present);
229 	__set_bit(IP_TUNNEL_GTP_OPT_BIT, present);
230 	__set_bit(IP_TUNNEL_PFCP_OPT_BIT, present);
231 
232 	ip_tunnel_flags_or(flags, flags, present);
233 }
234 
235 static inline void ip_tunnel_clear_options_present(unsigned long *flags)
236 {
237 	IP_TUNNEL_DECLARE_FLAGS(present) = { };
238 
239 	__set_bit(IP_TUNNEL_GENEVE_OPT_BIT, present);
240 	__set_bit(IP_TUNNEL_VXLAN_OPT_BIT, present);
241 	__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT, present);
242 	__set_bit(IP_TUNNEL_GTP_OPT_BIT, present);
243 	__set_bit(IP_TUNNEL_PFCP_OPT_BIT, present);
244 
245 	__ipt_flag_op(bitmap_andnot, flags, flags, present);
246 }
247 
248 static inline bool ip_tunnel_is_options_present(const unsigned long *flags)
249 {
250 	IP_TUNNEL_DECLARE_FLAGS(present) = { };
251 
252 	__set_bit(IP_TUNNEL_GENEVE_OPT_BIT, present);
253 	__set_bit(IP_TUNNEL_VXLAN_OPT_BIT, present);
254 	__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT, present);
255 	__set_bit(IP_TUNNEL_GTP_OPT_BIT, present);
256 	__set_bit(IP_TUNNEL_PFCP_OPT_BIT, present);
257 
258 	return ip_tunnel_flags_intersect(flags, present);
259 }
260 
261 static inline bool ip_tunnel_flags_is_be16_compat(const unsigned long *flags)
262 {
263 	IP_TUNNEL_DECLARE_FLAGS(supp) = { };
264 
265 	bitmap_set(supp, 0, BITS_PER_TYPE(__be16));
266 	__set_bit(IP_TUNNEL_VTI_BIT, supp);
267 
268 	return ip_tunnel_flags_subset(flags, supp);
269 }
270 
271 static inline void ip_tunnel_flags_from_be16(unsigned long *dst, __be16 flags)
272 {
273 	ip_tunnel_flags_zero(dst);
274 
275 	bitmap_write(dst, be16_to_cpu(flags), 0, BITS_PER_TYPE(__be16));
276 	__assign_bit(IP_TUNNEL_VTI_BIT, dst, flags & VTI_ISVTI);
277 }
278 
279 static inline __be16 ip_tunnel_flags_to_be16(const unsigned long *flags)
280 {
281 	__be16 ret;
282 
283 	ret = cpu_to_be16(bitmap_read(flags, 0, BITS_PER_TYPE(__be16)));
284 	if (test_bit(IP_TUNNEL_VTI_BIT, flags))
285 		ret |= VTI_ISVTI;
286 
287 	return ret;
288 }
289 
290 static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
291 				      __be32 saddr, __be32 daddr,
292 				      u8 tos, u8 ttl, __be32 label,
293 				      __be16 tp_src, __be16 tp_dst,
294 				      __be64 tun_id,
295 				      const unsigned long *tun_flags)
296 {
297 	key->tun_id = tun_id;
298 	key->u.ipv4.src = saddr;
299 	key->u.ipv4.dst = daddr;
300 	memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
301 	       0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
302 	key->tos = tos;
303 	key->ttl = ttl;
304 	key->label = label;
305 	ip_tunnel_flags_copy(key->tun_flags, tun_flags);
306 
307 	/* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
308 	 * the upper tunnel are used.
309 	 * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
310 	 */
311 	key->tp_src = tp_src;
312 	key->tp_dst = tp_dst;
313 
314 	/* Clear struct padding. */
315 	if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
316 		memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
317 		       0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
318 }
319 
320 static inline bool
321 ip_tunnel_dst_cache_usable(const struct sk_buff *skb,
322 			   const struct ip_tunnel_info *info)
323 {
324 	if (skb->mark)
325 		return false;
326 
327 	return !info || !test_bit(IP_TUNNEL_NOCACHE_BIT, info->key.tun_flags);
328 }
329 
330 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
331 					       *tun_info)
332 {
333 	return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
334 }
335 
336 static inline __be64 key32_to_tunnel_id(__be32 key)
337 {
338 #ifdef __BIG_ENDIAN
339 	return (__force __be64)key;
340 #else
341 	return (__force __be64)((__force u64)key << 32);
342 #endif
343 }
344 
345 /* Returns the least-significant 32 bits of a __be64. */
346 static inline __be32 tunnel_id_to_key32(__be64 tun_id)
347 {
348 #ifdef __BIG_ENDIAN
349 	return (__force __be32)tun_id;
350 #else
351 	return (__force __be32)((__force u64)tun_id >> 32);
352 #endif
353 }
354 
355 #ifdef CONFIG_INET
356 
357 static inline void ip_tunnel_init_flow(struct flowi4 *fl4,
358 				       int proto,
359 				       __be32 daddr, __be32 saddr,
360 				       __be32 key, __u8 tos,
361 				       struct net *net, int oif,
362 				       __u32 mark, __u32 tun_inner_hash,
363 				       __u8 flow_flags)
364 {
365 	memset(fl4, 0, sizeof(*fl4));
366 
367 	if (oif) {
368 		fl4->flowi4_l3mdev = l3mdev_master_upper_ifindex_by_index(net, oif);
369 		/* Legacy VRF/l3mdev use case */
370 		fl4->flowi4_oif = fl4->flowi4_l3mdev ? 0 : oif;
371 	}
372 
373 	fl4->daddr = daddr;
374 	fl4->saddr = saddr;
375 	fl4->flowi4_dscp = inet_dsfield_to_dscp(tos);
376 	fl4->flowi4_proto = proto;
377 	fl4->fl4_gre_key = key;
378 	fl4->flowi4_mark = mark;
379 	fl4->flowi4_multipath_hash = tun_inner_hash;
380 	fl4->flowi4_flags = flow_flags;
381 }
382 
383 int __ip_tunnel_init(struct net_device *dev);
384 #define ip_tunnel_init(DEV)			\
385 ({						\
386 	struct net_device *__dev = (DEV);	\
387 	int __res = __ip_tunnel_init(__dev);	\
388 						\
389 	if (!__res)				\
390 		netdev_lockdep_set_classes(__dev);\
391 	__res;					\
392 })
393 
394 void ip_tunnel_uninit(struct net_device *dev);
395 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
396 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
397 int ip_tunnel_get_iflink(const struct net_device *dev);
398 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
399 		       struct rtnl_link_ops *ops, char *devname);
400 void ip_tunnel_delete_net(struct net *net, unsigned int id,
401 			  struct rtnl_link_ops *ops,
402 			  struct list_head *dev_to_kill);
403 
404 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
405 		    const struct iphdr *tnl_params, const u8 protocol);
406 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
407 		       const u8 proto, int tunnel_hlen);
408 int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm_kern *p,
409 		  int cmd);
410 bool ip_tunnel_parm_from_user(struct ip_tunnel_parm_kern *kp,
411 			      const void __user *data);
412 bool ip_tunnel_parm_to_user(void __user *data, struct ip_tunnel_parm_kern *kp);
413 int ip_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
414 			     void __user *data, int cmd);
415 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
416 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
417 
418 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
419 				   int link, const unsigned long *flags,
420 				   __be32 remote, __be32 local,
421 				   __be32 key);
422 
423 void ip_tunnel_md_udp_encap(struct sk_buff *skb, struct ip_tunnel_info *info);
424 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
425 		  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
426 		  bool log_ecn_error);
427 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
428 			 struct ip_tunnel_parm_kern *p, __u32 fwmark);
429 int ip_tunnel_newlink(struct net *net, struct net_device *dev,
430 		      struct nlattr *tb[], struct ip_tunnel_parm_kern *p,
431 		      __u32 fwmark);
432 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
433 
434 bool ip_tunnel_netlink_encap_parms(struct nlattr *data[],
435 				   struct ip_tunnel_encap *encap);
436 
437 void ip_tunnel_netlink_parms(struct nlattr *data[],
438 			     struct ip_tunnel_parm_kern *parms);
439 
440 extern const struct header_ops ip_tunnel_header_ops;
441 __be16 ip_tunnel_parse_protocol(const struct sk_buff *skb);
442 
443 struct ip_tunnel_encap_ops {
444 	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
445 	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
446 			    u8 *protocol, struct flowi4 *fl4);
447 	int (*err_handler)(struct sk_buff *skb, u32 info);
448 };
449 
450 #define MAX_IPTUN_ENCAP_OPS 8
451 
452 extern const struct ip_tunnel_encap_ops __rcu *
453 		iptun_encaps[MAX_IPTUN_ENCAP_OPS];
454 
455 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
456 			    unsigned int num);
457 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
458 			    unsigned int num);
459 
460 int ip_tunnel_encap_setup(struct ip_tunnel *t,
461 			  struct ip_tunnel_encap *ipencap);
462 
463 static inline enum skb_drop_reason
464 pskb_inet_may_pull_reason(struct sk_buff *skb)
465 {
466 	int nhlen;
467 
468 	switch (skb->protocol) {
469 #if IS_ENABLED(CONFIG_IPV6)
470 	case htons(ETH_P_IPV6):
471 		nhlen = sizeof(struct ipv6hdr);
472 		break;
473 #endif
474 	case htons(ETH_P_IP):
475 		nhlen = sizeof(struct iphdr);
476 		break;
477 	default:
478 		nhlen = 0;
479 	}
480 
481 	return pskb_network_may_pull_reason(skb, nhlen);
482 }
483 
484 static inline bool pskb_inet_may_pull(struct sk_buff *skb)
485 {
486 	return pskb_inet_may_pull_reason(skb) == SKB_NOT_DROPPED_YET;
487 }
488 
489 /* Variant of pskb_inet_may_pull().
490  */
491 static inline enum skb_drop_reason
492 skb_vlan_inet_prepare(struct sk_buff *skb, bool inner_proto_inherit)
493 {
494 	int nhlen = 0, maclen = inner_proto_inherit ? 0 : ETH_HLEN;
495 	__be16 type = skb->protocol;
496 	enum skb_drop_reason reason;
497 
498 	/* Essentially this is skb_protocol(skb, true)
499 	 * And we get MAC len.
500 	 */
501 	if (eth_type_vlan(type))
502 		type = __vlan_get_protocol(skb, type, &maclen);
503 
504 	switch (type) {
505 #if IS_ENABLED(CONFIG_IPV6)
506 	case htons(ETH_P_IPV6):
507 		nhlen = sizeof(struct ipv6hdr);
508 		break;
509 #endif
510 	case htons(ETH_P_IP):
511 		nhlen = sizeof(struct iphdr);
512 		break;
513 	}
514 	/* For ETH_P_IPV6/ETH_P_IP we make sure to pull
515 	 * a base network header in skb->head.
516 	 */
517 	reason = pskb_may_pull_reason(skb, maclen + nhlen);
518 	if (reason)
519 		return reason;
520 
521 	skb_set_network_header(skb, maclen);
522 
523 	return SKB_NOT_DROPPED_YET;
524 }
525 
526 static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
527 {
528 	const struct ip_tunnel_encap_ops *ops;
529 	int hlen = -EINVAL;
530 
531 	if (e->type == TUNNEL_ENCAP_NONE)
532 		return 0;
533 
534 	if (e->type >= MAX_IPTUN_ENCAP_OPS)
535 		return -EINVAL;
536 
537 	rcu_read_lock();
538 	ops = rcu_dereference(iptun_encaps[e->type]);
539 	if (likely(ops && ops->encap_hlen))
540 		hlen = ops->encap_hlen(e);
541 	rcu_read_unlock();
542 
543 	return hlen;
544 }
545 
546 static inline int ip_tunnel_encap(struct sk_buff *skb,
547 				  struct ip_tunnel_encap *e,
548 				  u8 *protocol, struct flowi4 *fl4)
549 {
550 	const struct ip_tunnel_encap_ops *ops;
551 	int ret = -EINVAL;
552 
553 	if (e->type == TUNNEL_ENCAP_NONE)
554 		return 0;
555 
556 	if (e->type >= MAX_IPTUN_ENCAP_OPS)
557 		return -EINVAL;
558 
559 	rcu_read_lock();
560 	ops = rcu_dereference(iptun_encaps[e->type]);
561 	if (likely(ops && ops->build_header))
562 		ret = ops->build_header(skb, e, protocol, fl4);
563 	rcu_read_unlock();
564 
565 	return ret;
566 }
567 
568 /* Extract dsfield from inner protocol */
569 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
570 				       const struct sk_buff *skb)
571 {
572 	__be16 payload_protocol = skb_protocol(skb, true);
573 
574 	if (payload_protocol == htons(ETH_P_IP))
575 		return iph->tos;
576 	else if (payload_protocol == htons(ETH_P_IPV6))
577 		return ipv6_get_dsfield((const struct ipv6hdr *)iph);
578 	else
579 		return 0;
580 }
581 
582 static inline __be32 ip_tunnel_get_flowlabel(const struct iphdr *iph,
583 					     const struct sk_buff *skb)
584 {
585 	__be16 payload_protocol = skb_protocol(skb, true);
586 
587 	if (payload_protocol == htons(ETH_P_IPV6))
588 		return ip6_flowlabel((const struct ipv6hdr *)iph);
589 	else
590 		return 0;
591 }
592 
593 static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph,
594 				       const struct sk_buff *skb)
595 {
596 	__be16 payload_protocol = skb_protocol(skb, true);
597 
598 	if (payload_protocol == htons(ETH_P_IP))
599 		return iph->ttl;
600 	else if (payload_protocol == htons(ETH_P_IPV6))
601 		return ((const struct ipv6hdr *)iph)->hop_limit;
602 	else
603 		return 0;
604 }
605 
606 /* Propagate ECN bits out */
607 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
608 				     const struct sk_buff *skb)
609 {
610 	u8 inner = ip_tunnel_get_dsfield(iph, skb);
611 
612 	return INET_ECN_encapsulate(tos, inner);
613 }
614 
615 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
616 			   __be16 inner_proto, bool raw_proto, bool xnet);
617 
618 static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
619 				       __be16 inner_proto, bool xnet)
620 {
621 	return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
622 }
623 
624 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
625 		   __be32 src, __be32 dst, u8 proto,
626 		   u8 tos, u8 ttl, __be16 df, bool xnet, u16 ipcb_flags);
627 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
628 					     gfp_t flags);
629 int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst,
630 			  int headroom, bool reply);
631 
632 static inline void ip_tunnel_adj_headroom(struct net_device *dev,
633 					  unsigned int headroom)
634 {
635 	/* we must cap headroom to some upperlimit, else pskb_expand_head
636 	 * will overflow header offsets in skb_headers_offset_update().
637 	 */
638 	const unsigned int max_allowed = 512;
639 
640 	if (headroom > max_allowed)
641 		headroom = max_allowed;
642 
643 	if (headroom > READ_ONCE(dev->needed_headroom))
644 		WRITE_ONCE(dev->needed_headroom, headroom);
645 }
646 
647 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
648 
649 static inline int iptunnel_pull_offloads(struct sk_buff *skb)
650 {
651 	if (skb_is_gso(skb)) {
652 		int err;
653 
654 		err = skb_unclone(skb, GFP_ATOMIC);
655 		if (unlikely(err))
656 			return err;
657 		skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
658 					       NETIF_F_GSO_SHIFT);
659 	}
660 
661 	skb->encapsulation = 0;
662 	return 0;
663 }
664 
665 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
666 {
667 	if (pkt_len > 0) {
668 		struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
669 
670 		u64_stats_update_begin(&tstats->syncp);
671 		u64_stats_add(&tstats->tx_bytes, pkt_len);
672 		u64_stats_inc(&tstats->tx_packets);
673 		u64_stats_update_end(&tstats->syncp);
674 		put_cpu_ptr(tstats);
675 		return;
676 	}
677 
678 	if (pkt_len < 0) {
679 		DEV_STATS_INC(dev, tx_errors);
680 		DEV_STATS_INC(dev, tx_aborted_errors);
681 	} else {
682 		DEV_STATS_INC(dev, tx_dropped);
683 	}
684 }
685 
686 static inline void ip_tunnel_info_opts_get(void *to,
687 					   const struct ip_tunnel_info *info)
688 {
689 	memcpy(to, ip_tunnel_info_opts(info), info->options_len);
690 }
691 
692 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
693 					   const void *from, int len,
694 					   const unsigned long *flags)
695 {
696 	info->options_len = len;
697 	if (len > 0) {
698 		memcpy(ip_tunnel_info_opts(info), from, len);
699 		ip_tunnel_flags_or(info->key.tun_flags, info->key.tun_flags,
700 				   flags);
701 	}
702 }
703 
704 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
705 {
706 	return (struct ip_tunnel_info *)lwtstate->data;
707 }
708 
709 DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
710 
711 /* Returns > 0 if metadata should be collected */
712 static inline int ip_tunnel_collect_metadata(void)
713 {
714 	return static_branch_unlikely(&ip_tunnel_metadata_cnt);
715 }
716 
717 void __init ip_tunnel_core_init(void);
718 
719 void ip_tunnel_need_metadata(void);
720 void ip_tunnel_unneed_metadata(void);
721 
722 #else /* CONFIG_INET */
723 
724 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
725 {
726 	return NULL;
727 }
728 
729 static inline void ip_tunnel_need_metadata(void)
730 {
731 }
732 
733 static inline void ip_tunnel_unneed_metadata(void)
734 {
735 }
736 
737 static inline void ip_tunnel_info_opts_get(void *to,
738 					   const struct ip_tunnel_info *info)
739 {
740 }
741 
742 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
743 					   const void *from, int len,
744 					   const unsigned long *flags)
745 {
746 	info->options_len = 0;
747 }
748 
749 #endif /* CONFIG_INET */
750 
751 #endif /* __NET_IP_TUNNELS_H */
752