xref: /openbmc/linux/include/net/vxlan.h (revision 8e74a48d)
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 struct vxlan_dev_node {
231 	struct hlist_node hlist;
232 	struct vxlan_dev *vxlan;
233 };
234 
235 /* Pseudo network device */
236 struct vxlan_dev {
237 	struct vxlan_dev_node hlist4;	/* vni hash table for IPv4 socket */
238 #if IS_ENABLED(CONFIG_IPV6)
239 	struct vxlan_dev_node hlist6;	/* vni hash table for IPv6 socket */
240 #endif
241 	struct list_head  next;		/* vxlan's per namespace list */
242 	struct vxlan_sock __rcu *vn4_sock;	/* listening socket for IPv4 */
243 #if IS_ENABLED(CONFIG_IPV6)
244 	struct vxlan_sock __rcu *vn6_sock;	/* listening socket for IPv6 */
245 #endif
246 	struct net_device *dev;
247 	struct net	  *net;		/* netns for packet i/o */
248 	struct vxlan_rdst default_dst;	/* default destination */
249 
250 	struct timer_list age_timer;
251 	spinlock_t	  hash_lock[FDB_HASH_SIZE];
252 	unsigned int	  addrcnt;
253 	struct gro_cells  gro_cells;
254 
255 	struct vxlan_config	cfg;
256 
257 	struct hlist_head fdb_head[FDB_HASH_SIZE];
258 };
259 
260 #define VXLAN_F_LEARN			0x01
261 #define VXLAN_F_PROXY			0x02
262 #define VXLAN_F_RSC			0x04
263 #define VXLAN_F_L2MISS			0x08
264 #define VXLAN_F_L3MISS			0x10
265 #define VXLAN_F_IPV6			0x20
266 #define VXLAN_F_UDP_ZERO_CSUM_TX	0x40
267 #define VXLAN_F_UDP_ZERO_CSUM6_TX	0x80
268 #define VXLAN_F_UDP_ZERO_CSUM6_RX	0x100
269 #define VXLAN_F_REMCSUM_TX		0x200
270 #define VXLAN_F_REMCSUM_RX		0x400
271 #define VXLAN_F_GBP			0x800
272 #define VXLAN_F_REMCSUM_NOPARTIAL	0x1000
273 #define VXLAN_F_COLLECT_METADATA	0x2000
274 #define VXLAN_F_GPE			0x4000
275 #define VXLAN_F_IPV6_LINKLOCAL		0x8000
276 #define VXLAN_F_TTL_INHERIT		0x10000
277 
278 /* Flags that are used in the receive path. These flags must match in
279  * order for a socket to be shareable
280  */
281 #define VXLAN_F_RCV_FLAGS		(VXLAN_F_GBP |			\
282 					 VXLAN_F_GPE |			\
283 					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
284 					 VXLAN_F_REMCSUM_RX |		\
285 					 VXLAN_F_REMCSUM_NOPARTIAL |	\
286 					 VXLAN_F_COLLECT_METADATA)
287 
288 /* Flags that can be set together with VXLAN_F_GPE. */
289 #define VXLAN_F_ALLOWED_GPE		(VXLAN_F_GPE |			\
290 					 VXLAN_F_IPV6 |			\
291 					 VXLAN_F_IPV6_LINKLOCAL |	\
292 					 VXLAN_F_UDP_ZERO_CSUM_TX |	\
293 					 VXLAN_F_UDP_ZERO_CSUM6_TX |	\
294 					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
295 					 VXLAN_F_COLLECT_METADATA)
296 
297 struct net_device *vxlan_dev_create(struct net *net, const char *name,
298 				    u8 name_assign_type, struct vxlan_config *conf);
299 
300 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
301 						     netdev_features_t features)
302 {
303 	u8 l4_hdr = 0;
304 
305 	if (!skb->encapsulation)
306 		return features;
307 
308 	switch (vlan_get_protocol(skb)) {
309 	case htons(ETH_P_IP):
310 		l4_hdr = ip_hdr(skb)->protocol;
311 		break;
312 	case htons(ETH_P_IPV6):
313 		l4_hdr = ipv6_hdr(skb)->nexthdr;
314 		break;
315 	default:
316 		return features;
317 	}
318 
319 	if ((l4_hdr == IPPROTO_UDP) &&
320 	    (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
321 	     skb->inner_protocol != htons(ETH_P_TEB) ||
322 	     (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
323 	      sizeof(struct udphdr) + sizeof(struct vxlanhdr)) ||
324 	     (skb->ip_summed != CHECKSUM_NONE &&
325 	      !can_checksum_protocol(features, inner_eth_hdr(skb)->h_proto))))
326 		return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
327 
328 	return features;
329 }
330 
331 /* IP header + UDP + VXLAN + Ethernet header */
332 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
333 /* IPv6 header + UDP + VXLAN + Ethernet header */
334 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
335 
336 static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
337 {
338 	return (struct vxlanhdr *)(udp_hdr(skb) + 1);
339 }
340 
341 static inline __be32 vxlan_vni(__be32 vni_field)
342 {
343 #if defined(__BIG_ENDIAN)
344 	return (__force __be32)((__force u32)vni_field >> 8);
345 #else
346 	return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
347 #endif
348 }
349 
350 static inline __be32 vxlan_vni_field(__be32 vni)
351 {
352 #if defined(__BIG_ENDIAN)
353 	return (__force __be32)((__force u32)vni << 8);
354 #else
355 	return (__force __be32)((__force u32)vni >> 8);
356 #endif
357 }
358 
359 static inline size_t vxlan_rco_start(__be32 vni_field)
360 {
361 	return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
362 }
363 
364 static inline size_t vxlan_rco_offset(__be32 vni_field)
365 {
366 	return (vni_field & VXLAN_RCO_UDP) ?
367 		offsetof(struct udphdr, check) :
368 		offsetof(struct tcphdr, check);
369 }
370 
371 static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
372 {
373 	__be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
374 
375 	if (offset == offsetof(struct udphdr, check))
376 		vni_field |= VXLAN_RCO_UDP;
377 	return vni_field;
378 }
379 
380 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
381 {
382 	return vs->sock->sk->sk_family;
383 }
384 
385 #if IS_ENABLED(CONFIG_IPV6)
386 
387 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
388 {
389 	if (ipa->sa.sa_family == AF_INET6)
390 		return ipv6_addr_any(&ipa->sin6.sin6_addr);
391 	else
392 		return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
393 }
394 
395 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
396 {
397 	if (ipa->sa.sa_family == AF_INET6)
398 		return ipv6_addr_is_multicast(&ipa->sin6.sin6_addr);
399 	else
400 		return ipv4_is_multicast(ipa->sin.sin_addr.s_addr);
401 }
402 
403 #else /* !IS_ENABLED(CONFIG_IPV6) */
404 
405 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
406 {
407 	return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
408 }
409 
410 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
411 {
412 	return ipv4_is_multicast(ipa->sin.sin_addr.s_addr);
413 }
414 
415 #endif /* IS_ENABLED(CONFIG_IPV6) */
416 
417 static inline bool netif_is_vxlan(const struct net_device *dev)
418 {
419 	return dev->rtnl_link_ops &&
420 	       !strcmp(dev->rtnl_link_ops->kind, "vxlan");
421 }
422 
423 struct switchdev_notifier_vxlan_fdb_info {
424 	struct switchdev_notifier_info info; /* must be first */
425 	union vxlan_addr remote_ip;
426 	__be16 remote_port;
427 	__be32 remote_vni;
428 	u32 remote_ifindex;
429 	u8 eth_addr[ETH_ALEN];
430 	__be32 vni;
431 	bool offloaded;
432 	bool added_by_user;
433 };
434 
435 #if IS_ENABLED(CONFIG_VXLAN)
436 int vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
437 		      struct switchdev_notifier_vxlan_fdb_info *fdb_info);
438 int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
439 		     struct notifier_block *nb,
440 		     struct netlink_ext_ack *extack);
441 void vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni);
442 
443 #else
444 static inline int
445 vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
446 		  struct switchdev_notifier_vxlan_fdb_info *fdb_info)
447 {
448 	return -ENOENT;
449 }
450 
451 static inline int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
452 				   struct notifier_block *nb,
453 				   struct netlink_ext_ack *extack)
454 {
455 	return -EOPNOTSUPP;
456 }
457 
458 static inline void
459 vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni)
460 {
461 }
462 #endif
463 
464 static inline void vxlan_flag_attr_error(int attrtype,
465 					 struct netlink_ext_ack *extack)
466 {
467 #define VXLAN_FLAG(flg) \
468 	case IFLA_VXLAN_##flg: \
469 		NL_SET_ERR_MSG_MOD(extack, \
470 				   "cannot change " #flg " flag"); \
471 		break
472 	switch (attrtype) {
473 	VXLAN_FLAG(TTL_INHERIT);
474 	VXLAN_FLAG(LEARNING);
475 	VXLAN_FLAG(PROXY);
476 	VXLAN_FLAG(RSC);
477 	VXLAN_FLAG(L2MISS);
478 	VXLAN_FLAG(L3MISS);
479 	VXLAN_FLAG(COLLECT_METADATA);
480 	VXLAN_FLAG(UDP_ZERO_CSUM6_TX);
481 	VXLAN_FLAG(UDP_ZERO_CSUM6_RX);
482 	VXLAN_FLAG(REMCSUM_TX);
483 	VXLAN_FLAG(REMCSUM_RX);
484 	VXLAN_FLAG(GBP);
485 	VXLAN_FLAG(GPE);
486 	VXLAN_FLAG(REMCSUM_NOPARTIAL);
487 	default:
488 		NL_SET_ERR_MSG_MOD(extack, \
489 				   "cannot change flag");
490 		break;
491 	}
492 #undef VXLAN_FLAG
493 }
494 
495 static inline bool vxlan_fdb_nh_path_select(struct nexthop *nh,
496 					    int hash,
497 					    struct vxlan_rdst *rdst)
498 {
499 	struct fib_nh_common *nhc;
500 
501 	nhc = nexthop_path_fdb_result(nh, hash);
502 	if (unlikely(!nhc))
503 		return false;
504 
505 	switch (nhc->nhc_gw_family) {
506 	case AF_INET:
507 		rdst->remote_ip.sin.sin_addr.s_addr = nhc->nhc_gw.ipv4;
508 		rdst->remote_ip.sa.sa_family = AF_INET;
509 		break;
510 	case AF_INET6:
511 		rdst->remote_ip.sin6.sin6_addr = nhc->nhc_gw.ipv6;
512 		rdst->remote_ip.sa.sa_family = AF_INET6;
513 		break;
514 	}
515 
516 	return true;
517 }
518 
519 #endif
520