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