xref: /linux/include/net/vxlan.h (revision 1b0975ee3bdd3eb19a47371c26fd7ef8f7f6b599)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __NET_VXLAN_H
3 #define __NET_VXLAN_H 1
4 
5 #include <linux/if_vlan.h>
6 #include <linux/rhashtable-types.h>
7 #include <net/udp_tunnel.h>
8 #include <net/dst_metadata.h>
9 #include <net/rtnetlink.h>
10 #include <net/switchdev.h>
11 #include <net/nexthop.h>
12 
13 #define IANA_VXLAN_UDP_PORT     4789
14 #define IANA_VXLAN_GPE_UDP_PORT 4790
15 
16 /* VXLAN protocol (RFC 7348) header:
17  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
18  * |R|R|R|R|I|R|R|R|               Reserved                        |
19  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
20  * |                VXLAN Network Identifier (VNI) |   Reserved    |
21  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
22  *
23  * I = VXLAN Network Identifier (VNI) present.
24  */
25 struct vxlanhdr {
26 	__be32 vx_flags;
27 	__be32 vx_vni;
28 };
29 
30 /* VXLAN header flags. */
31 #define VXLAN_HF_VNI	cpu_to_be32(BIT(27))
32 
33 #define VXLAN_N_VID     (1u << 24)
34 #define VXLAN_VID_MASK  (VXLAN_N_VID - 1)
35 #define VXLAN_VNI_MASK	cpu_to_be32(VXLAN_VID_MASK << 8)
36 #define VXLAN_HLEN (sizeof(struct udphdr) + sizeof(struct vxlanhdr))
37 
38 #define VNI_HASH_BITS	10
39 #define VNI_HASH_SIZE	(1<<VNI_HASH_BITS)
40 #define FDB_HASH_BITS	8
41 #define FDB_HASH_SIZE	(1<<FDB_HASH_BITS)
42 
43 /* Remote checksum offload for VXLAN (VXLAN_F_REMCSUM_[RT]X):
44  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
45  * |R|R|R|R|I|R|R|R|R|R|C|              Reserved                   |
46  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
47  * |           VXLAN Network Identifier (VNI)      |O| Csum start  |
48  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
49  *
50  * C = Remote checksum offload bit. When set indicates that the
51  *     remote checksum offload data is present.
52  *
53  * O = Offset bit. Indicates the checksum offset relative to
54  *     checksum start.
55  *
56  * Csum start = Checksum start divided by two.
57  *
58  * http://tools.ietf.org/html/draft-herbert-vxlan-rco
59  */
60 
61 /* VXLAN-RCO header flags. */
62 #define VXLAN_HF_RCO	cpu_to_be32(BIT(21))
63 
64 /* Remote checksum offload header option */
65 #define VXLAN_RCO_MASK	cpu_to_be32(0x7f)  /* Last byte of vni field */
66 #define VXLAN_RCO_UDP	cpu_to_be32(0x80)  /* Indicate UDP RCO (TCP when not set *) */
67 #define VXLAN_RCO_SHIFT	1		   /* Left shift of start */
68 #define VXLAN_RCO_SHIFT_MASK ((1 << VXLAN_RCO_SHIFT) - 1)
69 #define VXLAN_MAX_REMCSUM_START (0x7f << VXLAN_RCO_SHIFT)
70 
71 /*
72  * VXLAN Group Based Policy Extension (VXLAN_F_GBP):
73  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
74  * |G|R|R|R|I|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
75  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
76  * |                VXLAN Network Identifier (VNI) |   Reserved    |
77  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
78  *
79  * G = Group Policy ID present.
80  *
81  * D = Don't Learn bit. When set, this bit indicates that the egress
82  *     VTEP MUST NOT learn the source address of the encapsulated frame.
83  *
84  * A = Indicates that the group policy has already been applied to
85  *     this packet. Policies MUST NOT be applied by devices when the
86  *     A bit is set.
87  *
88  * https://tools.ietf.org/html/draft-smith-vxlan-group-policy
89  */
90 struct vxlanhdr_gbp {
91 	u8	vx_flags;
92 #ifdef __LITTLE_ENDIAN_BITFIELD
93 	u8	reserved_flags1:3,
94 		policy_applied:1,
95 		reserved_flags2:2,
96 		dont_learn:1,
97 		reserved_flags3:1;
98 #elif defined(__BIG_ENDIAN_BITFIELD)
99 	u8	reserved_flags1:1,
100 		dont_learn:1,
101 		reserved_flags2:2,
102 		policy_applied:1,
103 		reserved_flags3:3;
104 #else
105 #error	"Please fix <asm/byteorder.h>"
106 #endif
107 	__be16	policy_id;
108 	__be32	vx_vni;
109 };
110 
111 /* VXLAN-GBP header flags. */
112 #define VXLAN_HF_GBP	cpu_to_be32(BIT(31))
113 
114 #define VXLAN_GBP_USED_BITS (VXLAN_HF_GBP | cpu_to_be32(0xFFFFFF))
115 
116 /* skb->mark mapping
117  *
118  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
119  * |R|R|R|R|R|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
120  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
121  */
122 #define VXLAN_GBP_DONT_LEARN		(BIT(6) << 16)
123 #define VXLAN_GBP_POLICY_APPLIED	(BIT(3) << 16)
124 #define VXLAN_GBP_ID_MASK		(0xFFFF)
125 
126 #define VXLAN_GBP_MASK (VXLAN_GBP_DONT_LEARN | VXLAN_GBP_POLICY_APPLIED | \
127 			VXLAN_GBP_ID_MASK)
128 
129 /*
130  * VXLAN Generic Protocol Extension (VXLAN_F_GPE):
131  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
132  * |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
133  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
134  * |                VXLAN Network Identifier (VNI) |   Reserved    |
135  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
136  *
137  * Ver = Version. Indicates VXLAN GPE protocol version.
138  *
139  * P = Next Protocol Bit. The P bit is set to indicate that the
140  *     Next Protocol field is present.
141  *
142  * O = OAM Flag Bit. The O bit is set to indicate that the packet
143  *     is an OAM packet.
144  *
145  * Next Protocol = This 8 bit field indicates the protocol header
146  * immediately following the VXLAN GPE header.
147  *
148  * https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-01
149  */
150 
151 struct vxlanhdr_gpe {
152 #if defined(__LITTLE_ENDIAN_BITFIELD)
153 	u8	oam_flag:1,
154 		reserved_flags1:1,
155 		np_applied:1,
156 		instance_applied:1,
157 		version:2,
158 		reserved_flags2:2;
159 #elif defined(__BIG_ENDIAN_BITFIELD)
160 	u8	reserved_flags2:2,
161 		version:2,
162 		instance_applied:1,
163 		np_applied:1,
164 		reserved_flags1:1,
165 		oam_flag:1;
166 #endif
167 	u8	reserved_flags3;
168 	u8	reserved_flags4;
169 	u8	next_protocol;
170 	__be32	vx_vni;
171 };
172 
173 /* VXLAN-GPE header flags. */
174 #define VXLAN_HF_VER	cpu_to_be32(BIT(29) | BIT(28))
175 #define VXLAN_HF_NP	cpu_to_be32(BIT(26))
176 #define VXLAN_HF_OAM	cpu_to_be32(BIT(24))
177 
178 #define VXLAN_GPE_USED_BITS (VXLAN_HF_VER | VXLAN_HF_NP | VXLAN_HF_OAM | \
179 			     cpu_to_be32(0xff))
180 
181 struct vxlan_metadata {
182 	u32		gbp;
183 };
184 
185 /* per UDP socket information */
186 struct vxlan_sock {
187 	struct hlist_node hlist;
188 	struct socket	 *sock;
189 	struct hlist_head vni_list[VNI_HASH_SIZE];
190 	refcount_t	  refcnt;
191 	u32		  flags;
192 };
193 
194 union vxlan_addr {
195 	struct sockaddr_in sin;
196 	struct sockaddr_in6 sin6;
197 	struct sockaddr sa;
198 };
199 
200 struct vxlan_rdst {
201 	union vxlan_addr	 remote_ip;
202 	__be16			 remote_port;
203 	u8			 offloaded:1;
204 	__be32			 remote_vni;
205 	u32			 remote_ifindex;
206 	struct net_device	 *remote_dev;
207 	struct list_head	 list;
208 	struct rcu_head		 rcu;
209 	struct dst_cache	 dst_cache;
210 };
211 
212 struct vxlan_config {
213 	union vxlan_addr	remote_ip;
214 	union vxlan_addr	saddr;
215 	__be32			vni;
216 	int			remote_ifindex;
217 	int			mtu;
218 	__be16			dst_port;
219 	u16			port_min;
220 	u16			port_max;
221 	u8			tos;
222 	u8			ttl;
223 	__be32			label;
224 	u32			flags;
225 	unsigned long		age_interval;
226 	unsigned int		addrmax;
227 	bool			no_share;
228 	enum ifla_vxlan_df	df;
229 };
230 
231 enum {
232 	VXLAN_VNI_STATS_RX,
233 	VXLAN_VNI_STATS_RX_DROPS,
234 	VXLAN_VNI_STATS_RX_ERRORS,
235 	VXLAN_VNI_STATS_TX,
236 	VXLAN_VNI_STATS_TX_DROPS,
237 	VXLAN_VNI_STATS_TX_ERRORS,
238 };
239 
240 struct vxlan_vni_stats {
241 	u64 rx_packets;
242 	u64 rx_bytes;
243 	u64 rx_drops;
244 	u64 rx_errors;
245 	u64 tx_packets;
246 	u64 tx_bytes;
247 	u64 tx_drops;
248 	u64 tx_errors;
249 };
250 
251 struct vxlan_vni_stats_pcpu {
252 	struct vxlan_vni_stats stats;
253 	struct u64_stats_sync syncp;
254 };
255 
256 struct vxlan_dev_node {
257 	struct hlist_node hlist;
258 	struct vxlan_dev *vxlan;
259 };
260 
261 struct vxlan_vni_node {
262 	struct rhash_head vnode;
263 	struct vxlan_dev_node hlist4; /* vni hash table for IPv4 socket */
264 #if IS_ENABLED(CONFIG_IPV6)
265 	struct vxlan_dev_node hlist6; /* vni hash table for IPv6 socket */
266 #endif
267 	struct list_head vlist;
268 	__be32 vni;
269 	union vxlan_addr remote_ip; /* default remote ip for this vni */
270 	struct vxlan_vni_stats_pcpu __percpu *stats;
271 
272 	struct rcu_head rcu;
273 };
274 
275 struct vxlan_vni_group {
276 	struct rhashtable	vni_hash;
277 	struct list_head	vni_list;
278 	u32			num_vnis;
279 };
280 
281 /* Pseudo network device */
282 struct vxlan_dev {
283 	struct vxlan_dev_node hlist4;	/* vni hash table for IPv4 socket */
284 #if IS_ENABLED(CONFIG_IPV6)
285 	struct vxlan_dev_node hlist6;	/* vni hash table for IPv6 socket */
286 #endif
287 	struct list_head  next;		/* vxlan's per namespace list */
288 	struct vxlan_sock __rcu *vn4_sock;	/* listening socket for IPv4 */
289 #if IS_ENABLED(CONFIG_IPV6)
290 	struct vxlan_sock __rcu *vn6_sock;	/* listening socket for IPv6 */
291 #endif
292 	struct net_device *dev;
293 	struct net	  *net;		/* netns for packet i/o */
294 	struct vxlan_rdst default_dst;	/* default destination */
295 
296 	struct timer_list age_timer;
297 	spinlock_t	  hash_lock[FDB_HASH_SIZE];
298 	unsigned int	  addrcnt;
299 	struct gro_cells  gro_cells;
300 
301 	struct vxlan_config	cfg;
302 
303 	struct vxlan_vni_group  __rcu *vnigrp;
304 
305 	struct hlist_head fdb_head[FDB_HASH_SIZE];
306 
307 	struct rhashtable mdb_tbl;
308 	struct hlist_head mdb_list;
309 	unsigned int mdb_seq;
310 };
311 
312 #define VXLAN_F_LEARN			0x01
313 #define VXLAN_F_PROXY			0x02
314 #define VXLAN_F_RSC			0x04
315 #define VXLAN_F_L2MISS			0x08
316 #define VXLAN_F_L3MISS			0x10
317 #define VXLAN_F_IPV6			0x20
318 #define VXLAN_F_UDP_ZERO_CSUM_TX	0x40
319 #define VXLAN_F_UDP_ZERO_CSUM6_TX	0x80
320 #define VXLAN_F_UDP_ZERO_CSUM6_RX	0x100
321 #define VXLAN_F_REMCSUM_TX		0x200
322 #define VXLAN_F_REMCSUM_RX		0x400
323 #define VXLAN_F_GBP			0x800
324 #define VXLAN_F_REMCSUM_NOPARTIAL	0x1000
325 #define VXLAN_F_COLLECT_METADATA	0x2000
326 #define VXLAN_F_GPE			0x4000
327 #define VXLAN_F_IPV6_LINKLOCAL		0x8000
328 #define VXLAN_F_TTL_INHERIT		0x10000
329 #define VXLAN_F_VNIFILTER               0x20000
330 #define VXLAN_F_MDB			0x40000
331 #define VXLAN_F_LOCALBYPASS		0x80000
332 
333 /* Flags that are used in the receive path. These flags must match in
334  * order for a socket to be shareable
335  */
336 #define VXLAN_F_RCV_FLAGS		(VXLAN_F_GBP |			\
337 					 VXLAN_F_GPE |			\
338 					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
339 					 VXLAN_F_REMCSUM_RX |		\
340 					 VXLAN_F_REMCSUM_NOPARTIAL |	\
341 					 VXLAN_F_COLLECT_METADATA |	\
342 					 VXLAN_F_VNIFILTER)
343 
344 /* Flags that can be set together with VXLAN_F_GPE. */
345 #define VXLAN_F_ALLOWED_GPE		(VXLAN_F_GPE |			\
346 					 VXLAN_F_IPV6 |			\
347 					 VXLAN_F_IPV6_LINKLOCAL |	\
348 					 VXLAN_F_UDP_ZERO_CSUM_TX |	\
349 					 VXLAN_F_UDP_ZERO_CSUM6_TX |	\
350 					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
351 					 VXLAN_F_COLLECT_METADATA  |	\
352 					 VXLAN_F_VNIFILTER         |    \
353 					 VXLAN_F_LOCALBYPASS)
354 
355 struct net_device *vxlan_dev_create(struct net *net, const char *name,
356 				    u8 name_assign_type, struct vxlan_config *conf);
357 
358 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
359 						     netdev_features_t features)
360 {
361 	u8 l4_hdr = 0;
362 
363 	if (!skb->encapsulation)
364 		return features;
365 
366 	switch (vlan_get_protocol(skb)) {
367 	case htons(ETH_P_IP):
368 		l4_hdr = ip_hdr(skb)->protocol;
369 		break;
370 	case htons(ETH_P_IPV6):
371 		l4_hdr = ipv6_hdr(skb)->nexthdr;
372 		break;
373 	default:
374 		return features;
375 	}
376 
377 	if ((l4_hdr == IPPROTO_UDP) &&
378 	    (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
379 	     skb->inner_protocol != htons(ETH_P_TEB) ||
380 	     (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
381 	      sizeof(struct udphdr) + sizeof(struct vxlanhdr)) ||
382 	     (skb->ip_summed != CHECKSUM_NONE &&
383 	      !can_checksum_protocol(features, inner_eth_hdr(skb)->h_proto))))
384 		return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
385 
386 	return features;
387 }
388 
389 /* IP header + UDP + VXLAN + Ethernet header */
390 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
391 /* IPv6 header + UDP + VXLAN + Ethernet header */
392 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
393 
394 static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
395 {
396 	return (struct vxlanhdr *)(udp_hdr(skb) + 1);
397 }
398 
399 static inline __be32 vxlan_vni(__be32 vni_field)
400 {
401 #if defined(__BIG_ENDIAN)
402 	return (__force __be32)((__force u32)vni_field >> 8);
403 #else
404 	return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
405 #endif
406 }
407 
408 static inline __be32 vxlan_vni_field(__be32 vni)
409 {
410 #if defined(__BIG_ENDIAN)
411 	return (__force __be32)((__force u32)vni << 8);
412 #else
413 	return (__force __be32)((__force u32)vni >> 8);
414 #endif
415 }
416 
417 static inline size_t vxlan_rco_start(__be32 vni_field)
418 {
419 	return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
420 }
421 
422 static inline size_t vxlan_rco_offset(__be32 vni_field)
423 {
424 	return (vni_field & VXLAN_RCO_UDP) ?
425 		offsetof(struct udphdr, check) :
426 		offsetof(struct tcphdr, check);
427 }
428 
429 static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
430 {
431 	__be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
432 
433 	if (offset == offsetof(struct udphdr, check))
434 		vni_field |= VXLAN_RCO_UDP;
435 	return vni_field;
436 }
437 
438 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
439 {
440 	return vs->sock->sk->sk_family;
441 }
442 
443 #if IS_ENABLED(CONFIG_IPV6)
444 
445 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
446 {
447 	if (ipa->sa.sa_family == AF_INET6)
448 		return ipv6_addr_any(&ipa->sin6.sin6_addr);
449 	else
450 		return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
451 }
452 
453 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
454 {
455 	if (ipa->sa.sa_family == AF_INET6)
456 		return ipv6_addr_is_multicast(&ipa->sin6.sin6_addr);
457 	else
458 		return ipv4_is_multicast(ipa->sin.sin_addr.s_addr);
459 }
460 
461 #else /* !IS_ENABLED(CONFIG_IPV6) */
462 
463 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
464 {
465 	return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
466 }
467 
468 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
469 {
470 	return ipv4_is_multicast(ipa->sin.sin_addr.s_addr);
471 }
472 
473 #endif /* IS_ENABLED(CONFIG_IPV6) */
474 
475 static inline bool netif_is_vxlan(const struct net_device *dev)
476 {
477 	return dev->rtnl_link_ops &&
478 	       !strcmp(dev->rtnl_link_ops->kind, "vxlan");
479 }
480 
481 struct switchdev_notifier_vxlan_fdb_info {
482 	struct switchdev_notifier_info info; /* must be first */
483 	union vxlan_addr remote_ip;
484 	__be16 remote_port;
485 	__be32 remote_vni;
486 	u32 remote_ifindex;
487 	u8 eth_addr[ETH_ALEN];
488 	__be32 vni;
489 	bool offloaded;
490 	bool added_by_user;
491 };
492 
493 #if IS_ENABLED(CONFIG_VXLAN)
494 int vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
495 		      struct switchdev_notifier_vxlan_fdb_info *fdb_info);
496 int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
497 		     struct notifier_block *nb,
498 		     struct netlink_ext_ack *extack);
499 void vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni);
500 
501 #else
502 static inline int
503 vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
504 		  struct switchdev_notifier_vxlan_fdb_info *fdb_info)
505 {
506 	return -ENOENT;
507 }
508 
509 static inline int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
510 				   struct notifier_block *nb,
511 				   struct netlink_ext_ack *extack)
512 {
513 	return -EOPNOTSUPP;
514 }
515 
516 static inline void
517 vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni)
518 {
519 }
520 #endif
521 
522 static inline void vxlan_flag_attr_error(int attrtype,
523 					 struct netlink_ext_ack *extack)
524 {
525 #define VXLAN_FLAG(flg) \
526 	case IFLA_VXLAN_##flg: \
527 		NL_SET_ERR_MSG_MOD(extack, \
528 				   "cannot change " #flg " flag"); \
529 		break
530 	switch (attrtype) {
531 	VXLAN_FLAG(TTL_INHERIT);
532 	VXLAN_FLAG(LEARNING);
533 	VXLAN_FLAG(PROXY);
534 	VXLAN_FLAG(RSC);
535 	VXLAN_FLAG(L2MISS);
536 	VXLAN_FLAG(L3MISS);
537 	VXLAN_FLAG(COLLECT_METADATA);
538 	VXLAN_FLAG(UDP_ZERO_CSUM6_TX);
539 	VXLAN_FLAG(UDP_ZERO_CSUM6_RX);
540 	VXLAN_FLAG(REMCSUM_TX);
541 	VXLAN_FLAG(REMCSUM_RX);
542 	VXLAN_FLAG(GBP);
543 	VXLAN_FLAG(GPE);
544 	VXLAN_FLAG(REMCSUM_NOPARTIAL);
545 	default:
546 		NL_SET_ERR_MSG_MOD(extack, \
547 				   "cannot change flag");
548 		break;
549 	}
550 #undef VXLAN_FLAG
551 }
552 
553 static inline bool vxlan_fdb_nh_path_select(struct nexthop *nh,
554 					    int hash,
555 					    struct vxlan_rdst *rdst)
556 {
557 	struct fib_nh_common *nhc;
558 
559 	nhc = nexthop_path_fdb_result(nh, hash);
560 	if (unlikely(!nhc))
561 		return false;
562 
563 	switch (nhc->nhc_gw_family) {
564 	case AF_INET:
565 		rdst->remote_ip.sin.sin_addr.s_addr = nhc->nhc_gw.ipv4;
566 		rdst->remote_ip.sa.sa_family = AF_INET;
567 		break;
568 	case AF_INET6:
569 		rdst->remote_ip.sin6.sin6_addr = nhc->nhc_gw.ipv6;
570 		rdst->remote_ip.sa.sa_family = AF_INET6;
571 		break;
572 	}
573 
574 	return true;
575 }
576 
577 static inline void vxlan_build_gbp_hdr(struct vxlanhdr *vxh, const struct vxlan_metadata *md)
578 {
579 	struct vxlanhdr_gbp *gbp;
580 
581 	if (!md->gbp)
582 		return;
583 
584 	gbp = (struct vxlanhdr_gbp *)vxh;
585 	vxh->vx_flags |= VXLAN_HF_GBP;
586 
587 	if (md->gbp & VXLAN_GBP_DONT_LEARN)
588 		gbp->dont_learn = 1;
589 
590 	if (md->gbp & VXLAN_GBP_POLICY_APPLIED)
591 		gbp->policy_applied = 1;
592 
593 	gbp->policy_id = htons(md->gbp & VXLAN_GBP_ID_MASK);
594 }
595 
596 #endif
597