xref: /linux/include/net/ip_tunnels.h (revision 9e995c573b63453a904f3157813dc8cde4a6aba4)
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 /* Keep error state on tunnel for 30 sec */
31 #define IPTUNNEL_ERR_TIMEO	(30*HZ)
32 
33 /* Used to memset ip_tunnel padding. */
34 #define IP_TUNNEL_KEY_SIZE	offsetofend(struct ip_tunnel_key, tp_dst)
35 
36 /* Used to memset ipv4 address padding. */
37 #define IP_TUNNEL_KEY_IPV4_PAD	offsetofend(struct ip_tunnel_key, u.ipv4.dst)
38 #define IP_TUNNEL_KEY_IPV4_PAD_LEN				\
39 	(sizeof_field(struct ip_tunnel_key, u) -		\
40 	 sizeof_field(struct ip_tunnel_key, u.ipv4))
41 
42 #define __ipt_flag_op(op, ...)					\
43 	op(__VA_ARGS__, __IP_TUNNEL_FLAG_NUM)
44 
45 #define IP_TUNNEL_DECLARE_FLAGS(...)				\
46 	__ipt_flag_op(DECLARE_BITMAP, __VA_ARGS__)
47 
48 #define ip_tunnel_flags_zero(...)	__ipt_flag_op(bitmap_zero, __VA_ARGS__)
49 #define ip_tunnel_flags_copy(...)	__ipt_flag_op(bitmap_copy, __VA_ARGS__)
50 #define ip_tunnel_flags_and(...)	__ipt_flag_op(bitmap_and, __VA_ARGS__)
51 #define ip_tunnel_flags_or(...)		__ipt_flag_op(bitmap_or, __VA_ARGS__)
52 
53 #define ip_tunnel_flags_empty(...)				\
54 	__ipt_flag_op(bitmap_empty, __VA_ARGS__)
55 #define ip_tunnel_flags_intersect(...)				\
56 	__ipt_flag_op(bitmap_intersects, __VA_ARGS__)
57 #define ip_tunnel_flags_subset(...)				\
58 	__ipt_flag_op(bitmap_subset, __VA_ARGS__)
59 
60 struct ip_tunnel_key {
61 	__be64			tun_id;
62 	union {
63 		struct {
64 			__be32	src;
65 			__be32	dst;
66 		} ipv4;
67 		struct {
68 			struct in6_addr src;
69 			struct in6_addr dst;
70 		} ipv6;
71 	} u;
72 	IP_TUNNEL_DECLARE_FLAGS(tun_flags);
73 	__be32			label;		/* Flow Label for IPv6 */
74 	u32			nhid;
75 	u8			tos;		/* TOS for IPv4, TC for IPv6 */
76 	u8			ttl;		/* TTL for IPv4, HL for IPv6 */
77 	__be16			tp_src;
78 	__be16			tp_dst;
79 	__u8			flow_flags;
80 };
81 
82 struct ip_tunnel_encap {
83 	u16			type;
84 	u16			flags;
85 	__be16			sport;
86 	__be16			dport;
87 };
88 
89 /* Flags for ip_tunnel_info mode. */
90 #define IP_TUNNEL_INFO_TX	0x01	/* represents tx tunnel parameters */
91 #define IP_TUNNEL_INFO_IPV6	0x02	/* key contains IPv6 addresses */
92 #define IP_TUNNEL_INFO_BRIDGE	0x04	/* represents a bridged tunnel id */
93 
94 /* Maximum tunnel options length. */
95 #define IP_TUNNEL_OPTS_MAX					\
96 	GENMASK((sizeof_field(struct ip_tunnel_info,		\
97 			      options_len) * BITS_PER_BYTE) - 1, 0)
98 
99 #define ip_tunnel_info_opts(info)				\
100 	_Generic(info,						\
101 		 const struct ip_tunnel_info * : ((const void *)(info)->options),\
102 		 struct ip_tunnel_info * : ((void *)(info)->options)\
103 	)
104 
105 struct ip_tunnel_info {
106 	struct ip_tunnel_key	key;
107 	struct ip_tunnel_encap	encap;
108 #ifdef CONFIG_DST_CACHE
109 	struct dst_cache	dst_cache;
110 #endif
111 	u8			options_len;
112 	u8			mode;
113 	u8			options[] __aligned_largest __counted_by(options_len);
114 };
115 
116 /* 6rd prefix/relay information */
117 #ifdef CONFIG_IPV6_SIT_6RD
118 struct ip_tunnel_6rd_parm {
119 	struct in6_addr		prefix;
120 	__be32			relay_prefix;
121 	u16			prefixlen;
122 	u16			relay_prefixlen;
123 };
124 #endif
125 
126 struct ip_tunnel_prl_entry {
127 	struct ip_tunnel_prl_entry __rcu *next;
128 	__be32				addr;
129 	u16				flags;
130 	struct rcu_head			rcu_head;
131 };
132 
133 struct metadata_dst;
134 
135 /* Kernel-side variant of ip_tunnel_parm */
136 struct ip_tunnel_parm_kern {
137 	char			name[IFNAMSIZ];
138 	IP_TUNNEL_DECLARE_FLAGS(i_flags);
139 	IP_TUNNEL_DECLARE_FLAGS(o_flags);
140 	__be32			i_key;
141 	__be32			o_key;
142 	int			link;
143 	struct iphdr		iph;
144 };
145 
146 struct ip_tunnel {
147 	struct ip_tunnel __rcu	*next;
148 	struct hlist_node hash_node;
149 
150 	struct net_device	*dev;
151 	netdevice_tracker	dev_tracker;
152 
153 	struct net		*net;	/* netns for packet i/o */
154 
155 	unsigned long	err_time;	/* Time when the last ICMP error
156 					 * arrived */
157 	int		err_count;	/* Number of arrived ICMP errors */
158 
159 	/* These four fields used only by GRE */
160 	u32		i_seqno;	/* The last seen seqno	*/
161 	atomic_t	o_seqno;	/* The last output seqno */
162 	int		tun_hlen;	/* Precalculated header length */
163 
164 	/* These four fields used only by ERSPAN */
165 	u32		index;		/* ERSPAN type II index */
166 	u8		erspan_ver;	/* ERSPAN version */
167 	u8		dir;		/* ERSPAN direction */
168 	u16		hwid;		/* ERSPAN hardware ID */
169 
170 	struct dst_cache dst_cache;
171 
172 	struct ip_tunnel_parm_kern parms;
173 
174 	int		mlink;
175 	int		encap_hlen;	/* Encap header length (FOU,GUE) */
176 	int		hlen;		/* tun_hlen + encap_hlen */
177 	struct ip_tunnel_encap encap;
178 
179 	/* for SIT */
180 #ifdef CONFIG_IPV6_SIT_6RD
181 	struct ip_tunnel_6rd_parm ip6rd;
182 #endif
183 	struct ip_tunnel_prl_entry __rcu *prl;	/* potential router list */
184 	unsigned int		prl_count;	/* # of entries in PRL */
185 	unsigned int		ip_tnl_net_id;
186 	struct gro_cells	gro_cells;
187 	__u32			fwmark;
188 	bool			collect_md;
189 	bool			ignore_df;
190 };
191 
192 struct tnl_ptk_info {
193 	IP_TUNNEL_DECLARE_FLAGS(flags);
194 	__be16 proto;
195 	__be32 key;
196 	__be32 seq;
197 	int hdr_len;
198 };
199 
200 #define PACKET_RCVD	0
201 #define PACKET_REJECT	1
202 #define PACKET_NEXT	2
203 
204 #define IP_TNL_HASH_BITS   7
205 #define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
206 
207 struct ip_tunnel_net {
208 	struct net_device *fb_tunnel_dev;
209 	struct rtnl_link_ops *rtnl_link_ops;
210 	struct hlist_head tunnels[IP_TNL_HASH_SIZE];
211 	struct ip_tunnel __rcu *collect_md_tun;
212 	int type;
213 };
214 
ip_tunnel_set_options_present(unsigned long * flags)215 static inline void ip_tunnel_set_options_present(unsigned long *flags)
216 {
217 	IP_TUNNEL_DECLARE_FLAGS(present) = { };
218 
219 	__set_bit(IP_TUNNEL_GENEVE_OPT_BIT, present);
220 	__set_bit(IP_TUNNEL_VXLAN_OPT_BIT, present);
221 	__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT, present);
222 	__set_bit(IP_TUNNEL_GTP_OPT_BIT, present);
223 	__set_bit(IP_TUNNEL_PFCP_OPT_BIT, present);
224 
225 	ip_tunnel_flags_or(flags, flags, present);
226 }
227 
ip_tunnel_clear_options_present(unsigned long * flags)228 static inline void ip_tunnel_clear_options_present(unsigned long *flags)
229 {
230 	IP_TUNNEL_DECLARE_FLAGS(present) = { };
231 
232 	__set_bit(IP_TUNNEL_GENEVE_OPT_BIT, present);
233 	__set_bit(IP_TUNNEL_VXLAN_OPT_BIT, present);
234 	__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT, present);
235 	__set_bit(IP_TUNNEL_GTP_OPT_BIT, present);
236 	__set_bit(IP_TUNNEL_PFCP_OPT_BIT, present);
237 
238 	__ipt_flag_op(bitmap_andnot, flags, flags, present);
239 }
240 
ip_tunnel_is_options_present(const unsigned long * flags)241 static inline bool ip_tunnel_is_options_present(const unsigned long *flags)
242 {
243 	IP_TUNNEL_DECLARE_FLAGS(present) = { };
244 
245 	__set_bit(IP_TUNNEL_GENEVE_OPT_BIT, present);
246 	__set_bit(IP_TUNNEL_VXLAN_OPT_BIT, present);
247 	__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT, present);
248 	__set_bit(IP_TUNNEL_GTP_OPT_BIT, present);
249 	__set_bit(IP_TUNNEL_PFCP_OPT_BIT, present);
250 
251 	return ip_tunnel_flags_intersect(flags, present);
252 }
253 
ip_tunnel_flags_is_be16_compat(const unsigned long * flags)254 static inline bool ip_tunnel_flags_is_be16_compat(const unsigned long *flags)
255 {
256 	IP_TUNNEL_DECLARE_FLAGS(supp) = { };
257 
258 	bitmap_set(supp, 0, BITS_PER_TYPE(__be16));
259 	__set_bit(IP_TUNNEL_VTI_BIT, supp);
260 
261 	return ip_tunnel_flags_subset(flags, supp);
262 }
263 
ip_tunnel_flags_from_be16(unsigned long * dst,__be16 flags)264 static inline void ip_tunnel_flags_from_be16(unsigned long *dst, __be16 flags)
265 {
266 	ip_tunnel_flags_zero(dst);
267 
268 	bitmap_write(dst, be16_to_cpu(flags), 0, BITS_PER_TYPE(__be16));
269 	__assign_bit(IP_TUNNEL_VTI_BIT, dst, flags & VTI_ISVTI);
270 }
271 
ip_tunnel_flags_to_be16(const unsigned long * flags)272 static inline __be16 ip_tunnel_flags_to_be16(const unsigned long *flags)
273 {
274 	__be16 ret;
275 
276 	ret = cpu_to_be16(bitmap_read(flags, 0, BITS_PER_TYPE(__be16)));
277 	if (test_bit(IP_TUNNEL_VTI_BIT, flags))
278 		ret |= VTI_ISVTI;
279 
280 	return ret;
281 }
282 
ip_tunnel_key_init(struct ip_tunnel_key * key,__be32 saddr,__be32 daddr,u8 tos,u8 ttl,__be32 label,__be16 tp_src,__be16 tp_dst,__be64 tun_id,const unsigned long * tun_flags)283 static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
284 				      __be32 saddr, __be32 daddr,
285 				      u8 tos, u8 ttl, __be32 label,
286 				      __be16 tp_src, __be16 tp_dst,
287 				      __be64 tun_id,
288 				      const unsigned long *tun_flags)
289 {
290 	key->tun_id = tun_id;
291 	key->u.ipv4.src = saddr;
292 	key->u.ipv4.dst = daddr;
293 	memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
294 	       0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
295 	key->tos = tos;
296 	key->ttl = ttl;
297 	key->label = label;
298 	ip_tunnel_flags_copy(key->tun_flags, tun_flags);
299 
300 	/* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
301 	 * the upper tunnel are used.
302 	 * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
303 	 */
304 	key->tp_src = tp_src;
305 	key->tp_dst = tp_dst;
306 
307 	/* Clear struct padding. */
308 	if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
309 		memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
310 		       0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
311 }
312 
313 static inline bool
ip_tunnel_dst_cache_usable(const struct sk_buff * skb,const struct ip_tunnel_info * info)314 ip_tunnel_dst_cache_usable(const struct sk_buff *skb,
315 			   const struct ip_tunnel_info *info)
316 {
317 	if (skb->mark)
318 		return false;
319 
320 	return !info || !test_bit(IP_TUNNEL_NOCACHE_BIT, info->key.tun_flags);
321 }
322 
ip_tunnel_info_af(const struct ip_tunnel_info * tun_info)323 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
324 					       *tun_info)
325 {
326 	return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
327 }
328 
key32_to_tunnel_id(__be32 key)329 static inline __be64 key32_to_tunnel_id(__be32 key)
330 {
331 #ifdef __BIG_ENDIAN
332 	return (__force __be64)key;
333 #else
334 	return (__force __be64)((__force u64)key << 32);
335 #endif
336 }
337 
338 /* Returns the least-significant 32 bits of a __be64. */
tunnel_id_to_key32(__be64 tun_id)339 static inline __be32 tunnel_id_to_key32(__be64 tun_id)
340 {
341 #ifdef __BIG_ENDIAN
342 	return (__force __be32)tun_id;
343 #else
344 	return (__force __be32)((__force u64)tun_id >> 32);
345 #endif
346 }
347 
348 #ifdef CONFIG_INET
349 
ip_tunnel_init_flow(struct flowi4 * fl4,int proto,__be32 daddr,__be32 saddr,__be32 key,__u8 tos,struct net * net,int oif,__u32 mark,__u32 tun_inner_hash,__u8 flow_flags)350 static inline void ip_tunnel_init_flow(struct flowi4 *fl4,
351 				       int proto,
352 				       __be32 daddr, __be32 saddr,
353 				       __be32 key, __u8 tos,
354 				       struct net *net, int oif,
355 				       __u32 mark, __u32 tun_inner_hash,
356 				       __u8 flow_flags)
357 {
358 	memset(fl4, 0, sizeof(*fl4));
359 
360 	if (oif) {
361 		fl4->flowi4_l3mdev = l3mdev_master_upper_ifindex_by_index(net, oif);
362 		/* Legacy VRF/l3mdev use case */
363 		fl4->flowi4_oif = fl4->flowi4_l3mdev ? 0 : oif;
364 	}
365 
366 	fl4->daddr = daddr;
367 	fl4->saddr = saddr;
368 	fl4->flowi4_dscp = inet_dsfield_to_dscp(tos);
369 	fl4->flowi4_proto = proto;
370 	fl4->fl4_gre_key = key;
371 	fl4->flowi4_mark = mark;
372 	fl4->flowi4_multipath_hash = tun_inner_hash;
373 	fl4->flowi4_flags = flow_flags;
374 }
375 
376 int __ip_tunnel_init(struct net_device *dev);
377 #define ip_tunnel_init(DEV)			\
378 ({						\
379 	struct net_device *__dev = (DEV);	\
380 	int __res = __ip_tunnel_init(__dev);	\
381 						\
382 	if (!__res)				\
383 		netdev_lockdep_set_classes(__dev);\
384 	__res;					\
385 })
386 
387 void ip_tunnel_uninit(struct net_device *dev);
388 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
389 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
390 int ip_tunnel_get_iflink(const struct net_device *dev);
391 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
392 		       struct rtnl_link_ops *ops, char *devname);
393 void ip_tunnel_delete_net(struct net *net, unsigned int id,
394 			  struct rtnl_link_ops *ops,
395 			  struct list_head *dev_to_kill);
396 
397 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
398 		    const struct iphdr *tnl_params, const u8 protocol);
399 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
400 		       const u8 proto, int tunnel_hlen);
401 int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm_kern *p,
402 		  int cmd);
403 bool ip_tunnel_parm_from_user(struct ip_tunnel_parm_kern *kp,
404 			      const void __user *data);
405 bool ip_tunnel_parm_to_user(void __user *data, struct ip_tunnel_parm_kern *kp);
406 int ip_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
407 			     void __user *data, int cmd);
408 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
409 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
410 
411 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
412 				   int link, const unsigned long *flags,
413 				   __be32 remote, __be32 local,
414 				   __be32 key);
415 
416 void ip_tunnel_md_udp_encap(struct sk_buff *skb, struct ip_tunnel_info *info);
417 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
418 		  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
419 		  bool log_ecn_error);
420 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
421 			 struct ip_tunnel_parm_kern *p, __u32 fwmark);
422 int ip_tunnel_newlink(struct net *net, struct net_device *dev,
423 		      struct nlattr *tb[], struct ip_tunnel_parm_kern *p,
424 		      __u32 fwmark);
425 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
426 
427 bool ip_tunnel_netlink_encap_parms(struct nlattr *data[],
428 				   struct ip_tunnel_encap *encap);
429 
430 void ip_tunnel_netlink_parms(struct nlattr *data[],
431 			     struct ip_tunnel_parm_kern *parms);
432 
433 extern const struct header_ops ip_tunnel_header_ops;
434 __be16 ip_tunnel_parse_protocol(const struct sk_buff *skb);
435 
436 struct ip_tunnel_encap_ops {
437 	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
438 	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
439 			    u8 *protocol, struct flowi4 *fl4);
440 	int (*err_handler)(struct sk_buff *skb, u32 info);
441 };
442 
443 #define MAX_IPTUN_ENCAP_OPS 8
444 
445 extern const struct ip_tunnel_encap_ops __rcu *
446 		iptun_encaps[MAX_IPTUN_ENCAP_OPS];
447 
448 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
449 			    unsigned int num);
450 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
451 			    unsigned int num);
452 
453 int ip_tunnel_encap_setup(struct ip_tunnel *t,
454 			  struct ip_tunnel_encap *ipencap);
455 
456 static inline enum skb_drop_reason
pskb_inet_may_pull_reason(struct sk_buff * skb)457 pskb_inet_may_pull_reason(struct sk_buff *skb)
458 {
459 	int nhlen;
460 
461 	switch (skb->protocol) {
462 #if IS_ENABLED(CONFIG_IPV6)
463 	case htons(ETH_P_IPV6):
464 		nhlen = sizeof(struct ipv6hdr);
465 		break;
466 #endif
467 	case htons(ETH_P_IP):
468 		nhlen = sizeof(struct iphdr);
469 		break;
470 	default:
471 		nhlen = 0;
472 	}
473 
474 	return pskb_network_may_pull_reason(skb, nhlen);
475 }
476 
pskb_inet_may_pull(struct sk_buff * skb)477 static inline bool pskb_inet_may_pull(struct sk_buff *skb)
478 {
479 	return pskb_inet_may_pull_reason(skb) == SKB_NOT_DROPPED_YET;
480 }
481 
482 /* Variant of pskb_inet_may_pull().
483  */
484 static inline enum skb_drop_reason
skb_vlan_inet_prepare(struct sk_buff * skb,bool inner_proto_inherit)485 skb_vlan_inet_prepare(struct sk_buff *skb, bool inner_proto_inherit)
486 {
487 	int nhlen = 0, maclen = inner_proto_inherit ? 0 : ETH_HLEN;
488 	__be16 type = skb->protocol;
489 	enum skb_drop_reason reason;
490 
491 	/* Essentially this is skb_protocol(skb, true)
492 	 * And we get MAC len.
493 	 */
494 	if (eth_type_vlan(type))
495 		type = __vlan_get_protocol(skb, type, &maclen);
496 
497 	switch (type) {
498 #if IS_ENABLED(CONFIG_IPV6)
499 	case htons(ETH_P_IPV6):
500 		nhlen = sizeof(struct ipv6hdr);
501 		break;
502 #endif
503 	case htons(ETH_P_IP):
504 		nhlen = sizeof(struct iphdr);
505 		break;
506 	}
507 	/* For ETH_P_IPV6/ETH_P_IP we make sure to pull
508 	 * a base network header in skb->head.
509 	 */
510 	reason = pskb_may_pull_reason(skb, maclen + nhlen);
511 	if (reason)
512 		return reason;
513 
514 	skb_set_network_header(skb, maclen);
515 
516 	return SKB_NOT_DROPPED_YET;
517 }
518 
ip_encap_hlen(struct ip_tunnel_encap * e)519 static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
520 {
521 	const struct ip_tunnel_encap_ops *ops;
522 	int hlen = -EINVAL;
523 
524 	if (e->type == TUNNEL_ENCAP_NONE)
525 		return 0;
526 
527 	if (e->type >= MAX_IPTUN_ENCAP_OPS)
528 		return -EINVAL;
529 
530 	rcu_read_lock();
531 	ops = rcu_dereference(iptun_encaps[e->type]);
532 	if (likely(ops && ops->encap_hlen))
533 		hlen = ops->encap_hlen(e);
534 	rcu_read_unlock();
535 
536 	return hlen;
537 }
538 
ip_tunnel_encap(struct sk_buff * skb,struct ip_tunnel_encap * e,u8 * protocol,struct flowi4 * fl4)539 static inline int ip_tunnel_encap(struct sk_buff *skb,
540 				  struct ip_tunnel_encap *e,
541 				  u8 *protocol, struct flowi4 *fl4)
542 {
543 	const struct ip_tunnel_encap_ops *ops;
544 	int ret = -EINVAL;
545 
546 	if (e->type == TUNNEL_ENCAP_NONE)
547 		return 0;
548 
549 	if (e->type >= MAX_IPTUN_ENCAP_OPS)
550 		return -EINVAL;
551 
552 	rcu_read_lock();
553 	ops = rcu_dereference(iptun_encaps[e->type]);
554 	if (likely(ops && ops->build_header))
555 		ret = ops->build_header(skb, e, protocol, fl4);
556 	rcu_read_unlock();
557 
558 	return ret;
559 }
560 
561 /* Extract dsfield from inner protocol */
ip_tunnel_get_dsfield(const struct iphdr * iph,const struct sk_buff * skb)562 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
563 				       const struct sk_buff *skb)
564 {
565 	__be16 payload_protocol = skb_protocol(skb, true);
566 
567 	if (payload_protocol == htons(ETH_P_IP))
568 		return iph->tos;
569 	else if (payload_protocol == htons(ETH_P_IPV6))
570 		return ipv6_get_dsfield((const struct ipv6hdr *)iph);
571 	else
572 		return 0;
573 }
574 
ip_tunnel_get_flowlabel(const struct iphdr * iph,const struct sk_buff * skb)575 static inline __be32 ip_tunnel_get_flowlabel(const struct iphdr *iph,
576 					     const struct sk_buff *skb)
577 {
578 	__be16 payload_protocol = skb_protocol(skb, true);
579 
580 	if (payload_protocol == htons(ETH_P_IPV6))
581 		return ip6_flowlabel((const struct ipv6hdr *)iph);
582 	else
583 		return 0;
584 }
585 
ip_tunnel_get_ttl(const struct iphdr * iph,const struct sk_buff * skb)586 static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph,
587 				       const struct sk_buff *skb)
588 {
589 	__be16 payload_protocol = skb_protocol(skb, true);
590 
591 	if (payload_protocol == htons(ETH_P_IP))
592 		return iph->ttl;
593 	else if (payload_protocol == htons(ETH_P_IPV6))
594 		return ((const struct ipv6hdr *)iph)->hop_limit;
595 	else
596 		return 0;
597 }
598 
599 /* Propagate ECN bits out */
ip_tunnel_ecn_encap(u8 tos,const struct iphdr * iph,const struct sk_buff * skb)600 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
601 				     const struct sk_buff *skb)
602 {
603 	u8 inner = ip_tunnel_get_dsfield(iph, skb);
604 
605 	return INET_ECN_encapsulate(tos, inner);
606 }
607 
608 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
609 			   __be16 inner_proto, bool raw_proto, bool xnet);
610 
iptunnel_pull_header(struct sk_buff * skb,int hdr_len,__be16 inner_proto,bool xnet)611 static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
612 				       __be16 inner_proto, bool xnet)
613 {
614 	return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
615 }
616 
617 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
618 		   __be32 src, __be32 dst, u8 proto,
619 		   u8 tos, u8 ttl, __be16 df, bool xnet, u16 ipcb_flags);
620 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
621 					     gfp_t flags);
622 int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst,
623 			  int headroom, bool reply);
624 
ip_tunnel_adj_headroom(struct net_device * dev,unsigned int headroom)625 static inline void ip_tunnel_adj_headroom(struct net_device *dev,
626 					  unsigned int headroom)
627 {
628 	/* we must cap headroom to some upperlimit, else pskb_expand_head
629 	 * will overflow header offsets in skb_headers_offset_update().
630 	 */
631 	const unsigned int max_allowed = 512;
632 
633 	if (headroom > max_allowed)
634 		headroom = max_allowed;
635 
636 	if (headroom > READ_ONCE(dev->needed_headroom))
637 		WRITE_ONCE(dev->needed_headroom, headroom);
638 }
639 
640 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
641 
iptunnel_pull_offloads(struct sk_buff * skb)642 static inline int iptunnel_pull_offloads(struct sk_buff *skb)
643 {
644 	if (skb_is_gso(skb)) {
645 		int err;
646 
647 		err = skb_unclone(skb, GFP_ATOMIC);
648 		if (unlikely(err))
649 			return err;
650 		skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
651 					       NETIF_F_GSO_SHIFT);
652 	}
653 
654 	skb->encapsulation = 0;
655 	return 0;
656 }
657 
iptunnel_xmit_stats(struct net_device * dev,int pkt_len)658 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
659 {
660 	if (pkt_len > 0) {
661 		struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
662 
663 		u64_stats_update_begin(&tstats->syncp);
664 		u64_stats_add(&tstats->tx_bytes, pkt_len);
665 		u64_stats_inc(&tstats->tx_packets);
666 		u64_stats_update_end(&tstats->syncp);
667 		put_cpu_ptr(tstats);
668 		return;
669 	}
670 
671 	if (pkt_len < 0) {
672 		DEV_STATS_INC(dev, tx_errors);
673 		DEV_STATS_INC(dev, tx_aborted_errors);
674 	} else {
675 		DEV_STATS_INC(dev, tx_dropped);
676 	}
677 }
678 
ip_tunnel_info_opts_get(void * to,const struct ip_tunnel_info * info)679 static inline void ip_tunnel_info_opts_get(void *to,
680 					   const struct ip_tunnel_info *info)
681 {
682 	memcpy(to, ip_tunnel_info_opts(info), info->options_len);
683 }
684 
ip_tunnel_info_opts_set(struct ip_tunnel_info * info,const void * from,int len,const unsigned long * flags)685 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
686 					   const void *from, int len,
687 					   const unsigned long *flags)
688 {
689 	info->options_len = len;
690 	if (len > 0) {
691 		memcpy(ip_tunnel_info_opts(info), from, len);
692 		ip_tunnel_flags_or(info->key.tun_flags, info->key.tun_flags,
693 				   flags);
694 	}
695 }
696 
lwt_tun_info(struct lwtunnel_state * lwtstate)697 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
698 {
699 	return (struct ip_tunnel_info *)lwtstate->data;
700 }
701 
702 DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
703 
704 /* Returns > 0 if metadata should be collected */
ip_tunnel_collect_metadata(void)705 static inline int ip_tunnel_collect_metadata(void)
706 {
707 	return static_branch_unlikely(&ip_tunnel_metadata_cnt);
708 }
709 
710 void __init ip_tunnel_core_init(void);
711 
712 void ip_tunnel_need_metadata(void);
713 void ip_tunnel_unneed_metadata(void);
714 
715 #else /* CONFIG_INET */
716 
lwt_tun_info(struct lwtunnel_state * lwtstate)717 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
718 {
719 	return NULL;
720 }
721 
ip_tunnel_need_metadata(void)722 static inline void ip_tunnel_need_metadata(void)
723 {
724 }
725 
ip_tunnel_unneed_metadata(void)726 static inline void ip_tunnel_unneed_metadata(void)
727 {
728 }
729 
ip_tunnel_info_opts_get(void * to,const struct ip_tunnel_info * info)730 static inline void ip_tunnel_info_opts_get(void *to,
731 					   const struct ip_tunnel_info *info)
732 {
733 }
734 
ip_tunnel_info_opts_set(struct ip_tunnel_info * info,const void * from,int len,const unsigned long * flags)735 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
736 					   const void *from, int len,
737 					   const unsigned long *flags)
738 {
739 	info->options_len = 0;
740 }
741 
742 #endif /* CONFIG_INET */
743 
744 #endif /* __NET_IP_TUNNELS_H */
745