xref: /linux/include/net/vxlan.h (revision b5bee6ced21ca98389000b7017dd41b0cc37fa50)
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 <net/udp_tunnel.h>
7 #include <net/dst_metadata.h>
8 #include <net/rtnetlink.h>
9 #include <net/switchdev.h>
10 #include <net/nexthop.h>
11 
12 #define IANA_VXLAN_UDP_PORT     4789
13 #define IANA_VXLAN_GPE_UDP_PORT 4790
14 
15 /* VXLAN protocol (RFC 7348) header:
16  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
17  * |R|R|R|R|I|R|R|R|               Reserved                        |
18  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
19  * |                VXLAN Network Identifier (VNI) |   Reserved    |
20  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
21  *
22  * I = VXLAN Network Identifier (VNI) present.
23  */
24 struct vxlanhdr {
25 	__be32 vx_flags;
26 	__be32 vx_vni;
27 };
28 
29 /* VXLAN header flags. */
30 #define VXLAN_HF_VNI	cpu_to_be32(BIT(27))
31 
32 #define VXLAN_N_VID     (1u << 24)
33 #define VXLAN_VID_MASK  (VXLAN_N_VID - 1)
34 #define VXLAN_VNI_MASK	cpu_to_be32(VXLAN_VID_MASK << 8)
35 #define VXLAN_HLEN (sizeof(struct udphdr) + sizeof(struct vxlanhdr))
36 
37 #define VNI_HASH_BITS	10
38 #define VNI_HASH_SIZE	(1<<VNI_HASH_BITS)
39 #define FDB_HASH_BITS	8
40 #define FDB_HASH_SIZE	(1<<FDB_HASH_BITS)
41 
42 /* Remote checksum offload for VXLAN (VXLAN_F_REMCSUM_[RT]X):
43  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44  * |R|R|R|R|I|R|R|R|R|R|C|              Reserved                   |
45  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46  * |           VXLAN Network Identifier (VNI)      |O| Csum start  |
47  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
48  *
49  * C = Remote checksum offload bit. When set indicates that the
50  *     remote checksum offload data is present.
51  *
52  * O = Offset bit. Indicates the checksum offset relative to
53  *     checksum start.
54  *
55  * Csum start = Checksum start divided by two.
56  *
57  * http://tools.ietf.org/html/draft-herbert-vxlan-rco
58  */
59 
60 /* VXLAN-RCO header flags. */
61 #define VXLAN_HF_RCO	cpu_to_be32(BIT(21))
62 
63 /* Remote checksum offload header option */
64 #define VXLAN_RCO_MASK	cpu_to_be32(0x7f)  /* Last byte of vni field */
65 #define VXLAN_RCO_UDP	cpu_to_be32(0x80)  /* Indicate UDP RCO (TCP when not set *) */
66 #define VXLAN_RCO_SHIFT	1		   /* Left shift of start */
67 #define VXLAN_RCO_SHIFT_MASK ((1 << VXLAN_RCO_SHIFT) - 1)
68 #define VXLAN_MAX_REMCSUM_START (0x7f << VXLAN_RCO_SHIFT)
69 
70 /*
71  * VXLAN Group Based Policy Extension (VXLAN_F_GBP):
72  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
73  * |G|R|R|R|I|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
74  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
75  * |                VXLAN Network Identifier (VNI) |   Reserved    |
76  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
77  *
78  * G = Group Policy ID present.
79  *
80  * D = Don't Learn bit. When set, this bit indicates that the egress
81  *     VTEP MUST NOT learn the source address of the encapsulated frame.
82  *
83  * A = Indicates that the group policy has already been applied to
84  *     this packet. Policies MUST NOT be applied by devices when the
85  *     A bit is set.
86  *
87  * https://tools.ietf.org/html/draft-smith-vxlan-group-policy
88  */
89 struct vxlanhdr_gbp {
90 	u8	vx_flags;
91 #ifdef __LITTLE_ENDIAN_BITFIELD
92 	u8	reserved_flags1:3,
93 		policy_applied:1,
94 		reserved_flags2:2,
95 		dont_learn:1,
96 		reserved_flags3:1;
97 #elif defined(__BIG_ENDIAN_BITFIELD)
98 	u8	reserved_flags1:1,
99 		dont_learn:1,
100 		reserved_flags2:2,
101 		policy_applied:1,
102 		reserved_flags3:3;
103 #else
104 #error	"Please fix <asm/byteorder.h>"
105 #endif
106 	__be16	policy_id;
107 	__be32	vx_vni;
108 };
109 
110 /* VXLAN-GBP header flags. */
111 #define VXLAN_HF_GBP	cpu_to_be32(BIT(31))
112 
113 #define VXLAN_GBP_USED_BITS (VXLAN_HF_GBP | cpu_to_be32(0xFFFFFF))
114 
115 /* skb->mark mapping
116  *
117  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
118  * |R|R|R|R|R|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
119  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
120  */
121 #define VXLAN_GBP_DONT_LEARN		(BIT(6) << 16)
122 #define VXLAN_GBP_POLICY_APPLIED	(BIT(3) << 16)
123 #define VXLAN_GBP_ID_MASK		(0xFFFF)
124 
125 #define VXLAN_GBP_MASK (VXLAN_GBP_DONT_LEARN | VXLAN_GBP_POLICY_APPLIED | \
126 			VXLAN_GBP_ID_MASK)
127 
128 /*
129  * VXLAN Generic Protocol Extension (VXLAN_F_GPE):
130  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
131  * |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
132  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
133  * |                VXLAN Network Identifier (VNI) |   Reserved    |
134  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
135  *
136  * Ver = Version. Indicates VXLAN GPE protocol version.
137  *
138  * P = Next Protocol Bit. The P bit is set to indicate that the
139  *     Next Protocol field is present.
140  *
141  * O = OAM Flag Bit. The O bit is set to indicate that the packet
142  *     is an OAM packet.
143  *
144  * Next Protocol = This 8 bit field indicates the protocol header
145  * immediately following the VXLAN GPE header.
146  *
147  * https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-01
148  */
149 
150 struct vxlanhdr_gpe {
151 #if defined(__LITTLE_ENDIAN_BITFIELD)
152 	u8	oam_flag:1,
153 		reserved_flags1:1,
154 		np_applied:1,
155 		instance_applied:1,
156 		version:2,
157 		reserved_flags2:2;
158 #elif defined(__BIG_ENDIAN_BITFIELD)
159 	u8	reserved_flags2:2,
160 		version:2,
161 		instance_applied:1,
162 		np_applied:1,
163 		reserved_flags1:1,
164 		oam_flag:1;
165 #endif
166 	u8	reserved_flags3;
167 	u8	reserved_flags4;
168 	u8	next_protocol;
169 	__be32	vx_vni;
170 };
171 
172 /* VXLAN-GPE header flags. */
173 #define VXLAN_HF_VER	cpu_to_be32(BIT(29) | BIT(28))
174 #define VXLAN_HF_NP	cpu_to_be32(BIT(26))
175 #define VXLAN_HF_OAM	cpu_to_be32(BIT(24))
176 
177 #define VXLAN_GPE_USED_BITS (VXLAN_HF_VER | VXLAN_HF_NP | VXLAN_HF_OAM | \
178 			     cpu_to_be32(0xff))
179 
180 struct vxlan_metadata {
181 	u32		gbp;
182 };
183 
184 /* per UDP socket information */
185 struct vxlan_sock {
186 	struct hlist_node hlist;
187 	struct socket	 *sock;
188 	struct hlist_head vni_list[VNI_HASH_SIZE];
189 	refcount_t	  refcnt;
190 	u32		  flags;
191 };
192 
193 union vxlan_addr {
194 	struct sockaddr_in sin;
195 	struct sockaddr_in6 sin6;
196 	struct sockaddr sa;
197 };
198 
199 struct vxlan_rdst {
200 	union vxlan_addr	 remote_ip;
201 	__be16			 remote_port;
202 	u8			 offloaded:1;
203 	__be32			 remote_vni;
204 	u32			 remote_ifindex;
205 	struct net_device	 *remote_dev;
206 	struct list_head	 list;
207 	struct rcu_head		 rcu;
208 	struct dst_cache	 dst_cache;
209 };
210 
211 struct vxlan_config {
212 	union vxlan_addr	remote_ip;
213 	union vxlan_addr	saddr;
214 	__be32			vni;
215 	int			remote_ifindex;
216 	int			mtu;
217 	__be16			dst_port;
218 	u16			port_min;
219 	u16			port_max;
220 	u8			tos;
221 	u8			ttl;
222 	__be32			label;
223 	u32			flags;
224 	unsigned long		age_interval;
225 	unsigned int		addrmax;
226 	bool			no_share;
227 	enum ifla_vxlan_df	df;
228 };
229 
230 enum {
231 	VXLAN_VNI_STATS_RX,
232 	VXLAN_VNI_STATS_RX_DROPS,
233 	VXLAN_VNI_STATS_RX_ERRORS,
234 	VXLAN_VNI_STATS_TX,
235 	VXLAN_VNI_STATS_TX_DROPS,
236 	VXLAN_VNI_STATS_TX_ERRORS,
237 };
238 
239 struct vxlan_vni_stats {
240 	u64 rx_packets;
241 	u64 rx_bytes;
242 	u64 rx_drops;
243 	u64 rx_errors;
244 	u64 tx_packets;
245 	u64 tx_bytes;
246 	u64 tx_drops;
247 	u64 tx_errors;
248 };
249 
250 struct vxlan_vni_stats_pcpu {
251 	struct vxlan_vni_stats stats;
252 	struct u64_stats_sync syncp;
253 };
254 
255 struct vxlan_dev_node {
256 	struct hlist_node hlist;
257 	struct vxlan_dev *vxlan;
258 };
259 
260 struct vxlan_vni_node {
261 	struct rhash_head vnode;
262 	struct vxlan_dev_node hlist4; /* vni hash table for IPv4 socket */
263 #if IS_ENABLED(CONFIG_IPV6)
264 	struct vxlan_dev_node hlist6; /* vni hash table for IPv6 socket */
265 #endif
266 	struct list_head vlist;
267 	__be32 vni;
268 	union vxlan_addr remote_ip; /* default remote ip for this vni */
269 	struct vxlan_vni_stats_pcpu __percpu *stats;
270 
271 	struct rcu_head rcu;
272 };
273 
274 struct vxlan_vni_group {
275 	struct rhashtable	vni_hash;
276 	struct list_head	vni_list;
277 	u32			num_vnis;
278 };
279 
280 /* Pseudo network device */
281 struct vxlan_dev {
282 	struct vxlan_dev_node hlist4;	/* vni hash table for IPv4 socket */
283 #if IS_ENABLED(CONFIG_IPV6)
284 	struct vxlan_dev_node hlist6;	/* vni hash table for IPv6 socket */
285 #endif
286 	struct list_head  next;		/* vxlan's per namespace list */
287 	struct vxlan_sock __rcu *vn4_sock;	/* listening socket for IPv4 */
288 #if IS_ENABLED(CONFIG_IPV6)
289 	struct vxlan_sock __rcu *vn6_sock;	/* listening socket for IPv6 */
290 #endif
291 	struct net_device *dev;
292 	struct net	  *net;		/* netns for packet i/o */
293 	struct vxlan_rdst default_dst;	/* default destination */
294 
295 	struct timer_list age_timer;
296 	spinlock_t	  hash_lock[FDB_HASH_SIZE];
297 	unsigned int	  addrcnt;
298 	struct gro_cells  gro_cells;
299 
300 	struct vxlan_config	cfg;
301 
302 	struct vxlan_vni_group  __rcu *vnigrp;
303 
304 	struct hlist_head fdb_head[FDB_HASH_SIZE];
305 };
306 
307 #define VXLAN_F_LEARN			0x01
308 #define VXLAN_F_PROXY			0x02
309 #define VXLAN_F_RSC			0x04
310 #define VXLAN_F_L2MISS			0x08
311 #define VXLAN_F_L3MISS			0x10
312 #define VXLAN_F_IPV6			0x20
313 #define VXLAN_F_UDP_ZERO_CSUM_TX	0x40
314 #define VXLAN_F_UDP_ZERO_CSUM6_TX	0x80
315 #define VXLAN_F_UDP_ZERO_CSUM6_RX	0x100
316 #define VXLAN_F_REMCSUM_TX		0x200
317 #define VXLAN_F_REMCSUM_RX		0x400
318 #define VXLAN_F_GBP			0x800
319 #define VXLAN_F_REMCSUM_NOPARTIAL	0x1000
320 #define VXLAN_F_COLLECT_METADATA	0x2000
321 #define VXLAN_F_GPE			0x4000
322 #define VXLAN_F_IPV6_LINKLOCAL		0x8000
323 #define VXLAN_F_TTL_INHERIT		0x10000
324 #define VXLAN_F_VNIFILTER               0x20000
325 
326 /* Flags that are used in the receive path. These flags must match in
327  * order for a socket to be shareable
328  */
329 #define VXLAN_F_RCV_FLAGS		(VXLAN_F_GBP |			\
330 					 VXLAN_F_GPE |			\
331 					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
332 					 VXLAN_F_REMCSUM_RX |		\
333 					 VXLAN_F_REMCSUM_NOPARTIAL |	\
334 					 VXLAN_F_COLLECT_METADATA |	\
335 					 VXLAN_F_VNIFILTER)
336 
337 /* Flags that can be set together with VXLAN_F_GPE. */
338 #define VXLAN_F_ALLOWED_GPE		(VXLAN_F_GPE |			\
339 					 VXLAN_F_IPV6 |			\
340 					 VXLAN_F_IPV6_LINKLOCAL |	\
341 					 VXLAN_F_UDP_ZERO_CSUM_TX |	\
342 					 VXLAN_F_UDP_ZERO_CSUM6_TX |	\
343 					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
344 					 VXLAN_F_COLLECT_METADATA  |	\
345 					 VXLAN_F_VNIFILTER)
346 
347 struct net_device *vxlan_dev_create(struct net *net, const char *name,
348 				    u8 name_assign_type, struct vxlan_config *conf);
349 
350 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
351 						     netdev_features_t features)
352 {
353 	u8 l4_hdr = 0;
354 
355 	if (!skb->encapsulation)
356 		return features;
357 
358 	switch (vlan_get_protocol(skb)) {
359 	case htons(ETH_P_IP):
360 		l4_hdr = ip_hdr(skb)->protocol;
361 		break;
362 	case htons(ETH_P_IPV6):
363 		l4_hdr = ipv6_hdr(skb)->nexthdr;
364 		break;
365 	default:
366 		return features;
367 	}
368 
369 	if ((l4_hdr == IPPROTO_UDP) &&
370 	    (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
371 	     skb->inner_protocol != htons(ETH_P_TEB) ||
372 	     (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
373 	      sizeof(struct udphdr) + sizeof(struct vxlanhdr)) ||
374 	     (skb->ip_summed != CHECKSUM_NONE &&
375 	      !can_checksum_protocol(features, inner_eth_hdr(skb)->h_proto))))
376 		return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
377 
378 	return features;
379 }
380 
381 /* IP header + UDP + VXLAN + Ethernet header */
382 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
383 /* IPv6 header + UDP + VXLAN + Ethernet header */
384 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
385 
386 static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
387 {
388 	return (struct vxlanhdr *)(udp_hdr(skb) + 1);
389 }
390 
391 static inline __be32 vxlan_vni(__be32 vni_field)
392 {
393 #if defined(__BIG_ENDIAN)
394 	return (__force __be32)((__force u32)vni_field >> 8);
395 #else
396 	return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
397 #endif
398 }
399 
400 static inline __be32 vxlan_vni_field(__be32 vni)
401 {
402 #if defined(__BIG_ENDIAN)
403 	return (__force __be32)((__force u32)vni << 8);
404 #else
405 	return (__force __be32)((__force u32)vni >> 8);
406 #endif
407 }
408 
409 static inline size_t vxlan_rco_start(__be32 vni_field)
410 {
411 	return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
412 }
413 
414 static inline size_t vxlan_rco_offset(__be32 vni_field)
415 {
416 	return (vni_field & VXLAN_RCO_UDP) ?
417 		offsetof(struct udphdr, check) :
418 		offsetof(struct tcphdr, check);
419 }
420 
421 static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
422 {
423 	__be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
424 
425 	if (offset == offsetof(struct udphdr, check))
426 		vni_field |= VXLAN_RCO_UDP;
427 	return vni_field;
428 }
429 
430 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
431 {
432 	return vs->sock->sk->sk_family;
433 }
434 
435 #if IS_ENABLED(CONFIG_IPV6)
436 
437 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
438 {
439 	if (ipa->sa.sa_family == AF_INET6)
440 		return ipv6_addr_any(&ipa->sin6.sin6_addr);
441 	else
442 		return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
443 }
444 
445 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
446 {
447 	if (ipa->sa.sa_family == AF_INET6)
448 		return ipv6_addr_is_multicast(&ipa->sin6.sin6_addr);
449 	else
450 		return ipv4_is_multicast(ipa->sin.sin_addr.s_addr);
451 }
452 
453 #else /* !IS_ENABLED(CONFIG_IPV6) */
454 
455 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
456 {
457 	return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
458 }
459 
460 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
461 {
462 	return ipv4_is_multicast(ipa->sin.sin_addr.s_addr);
463 }
464 
465 #endif /* IS_ENABLED(CONFIG_IPV6) */
466 
467 static inline bool netif_is_vxlan(const struct net_device *dev)
468 {
469 	return dev->rtnl_link_ops &&
470 	       !strcmp(dev->rtnl_link_ops->kind, "vxlan");
471 }
472 
473 struct switchdev_notifier_vxlan_fdb_info {
474 	struct switchdev_notifier_info info; /* must be first */
475 	union vxlan_addr remote_ip;
476 	__be16 remote_port;
477 	__be32 remote_vni;
478 	u32 remote_ifindex;
479 	u8 eth_addr[ETH_ALEN];
480 	__be32 vni;
481 	bool offloaded;
482 	bool added_by_user;
483 };
484 
485 #if IS_ENABLED(CONFIG_VXLAN)
486 int vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
487 		      struct switchdev_notifier_vxlan_fdb_info *fdb_info);
488 int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
489 		     struct notifier_block *nb,
490 		     struct netlink_ext_ack *extack);
491 void vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni);
492 
493 #else
494 static inline int
495 vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
496 		  struct switchdev_notifier_vxlan_fdb_info *fdb_info)
497 {
498 	return -ENOENT;
499 }
500 
501 static inline int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
502 				   struct notifier_block *nb,
503 				   struct netlink_ext_ack *extack)
504 {
505 	return -EOPNOTSUPP;
506 }
507 
508 static inline void
509 vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni)
510 {
511 }
512 #endif
513 
514 static inline void vxlan_flag_attr_error(int attrtype,
515 					 struct netlink_ext_ack *extack)
516 {
517 #define VXLAN_FLAG(flg) \
518 	case IFLA_VXLAN_##flg: \
519 		NL_SET_ERR_MSG_MOD(extack, \
520 				   "cannot change " #flg " flag"); \
521 		break
522 	switch (attrtype) {
523 	VXLAN_FLAG(TTL_INHERIT);
524 	VXLAN_FLAG(LEARNING);
525 	VXLAN_FLAG(PROXY);
526 	VXLAN_FLAG(RSC);
527 	VXLAN_FLAG(L2MISS);
528 	VXLAN_FLAG(L3MISS);
529 	VXLAN_FLAG(COLLECT_METADATA);
530 	VXLAN_FLAG(UDP_ZERO_CSUM6_TX);
531 	VXLAN_FLAG(UDP_ZERO_CSUM6_RX);
532 	VXLAN_FLAG(REMCSUM_TX);
533 	VXLAN_FLAG(REMCSUM_RX);
534 	VXLAN_FLAG(GBP);
535 	VXLAN_FLAG(GPE);
536 	VXLAN_FLAG(REMCSUM_NOPARTIAL);
537 	default:
538 		NL_SET_ERR_MSG_MOD(extack, \
539 				   "cannot change flag");
540 		break;
541 	}
542 #undef VXLAN_FLAG
543 }
544 
545 static inline bool vxlan_fdb_nh_path_select(struct nexthop *nh,
546 					    int hash,
547 					    struct vxlan_rdst *rdst)
548 {
549 	struct fib_nh_common *nhc;
550 
551 	nhc = nexthop_path_fdb_result(nh, hash);
552 	if (unlikely(!nhc))
553 		return false;
554 
555 	switch (nhc->nhc_gw_family) {
556 	case AF_INET:
557 		rdst->remote_ip.sin.sin_addr.s_addr = nhc->nhc_gw.ipv4;
558 		rdst->remote_ip.sa.sa_family = AF_INET;
559 		break;
560 	case AF_INET6:
561 		rdst->remote_ip.sin6.sin6_addr = nhc->nhc_gw.ipv6;
562 		rdst->remote_ip.sa.sa_family = AF_INET6;
563 		break;
564 	}
565 
566 	return true;
567 }
568 
569 #endif
570