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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/udp_tunnel.h>
  9
 10/* VXLAN protocol (RFC 7348) header:
 11 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 12 * |R|R|R|R|I|R|R|R|               Reserved                        |
 13 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 14 * |                VXLAN Network Identifier (VNI) |   Reserved    |
 15 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 16 *
 17 * I = VXLAN Network Identifier (VNI) present.
 18 */
 19struct vxlanhdr {
 20	__be32 vx_flags;
 21	__be32 vx_vni;
 22};
 23
 24/* VXLAN header flags. */
 25#define VXLAN_HF_VNI	cpu_to_be32(BIT(27))
 26
 27#define VXLAN_N_VID     (1u << 24)
 28#define VXLAN_VID_MASK  (VXLAN_N_VID - 1)
 29#define VXLAN_VNI_MASK	cpu_to_be32(VXLAN_VID_MASK << 8)
 30#define VXLAN_HLEN (sizeof(struct udphdr) + sizeof(struct vxlanhdr))
 31
 32#define VNI_HASH_BITS	10
 33#define VNI_HASH_SIZE	(1<<VNI_HASH_BITS)
 34#define FDB_HASH_BITS	8
 35#define FDB_HASH_SIZE	(1<<FDB_HASH_BITS)
 36
 37/* Remote checksum offload for VXLAN (VXLAN_F_REMCSUM_[RT]X):
 38 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 39 * |R|R|R|R|I|R|R|R|R|R|C|              Reserved                   |
 40 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 41 * |           VXLAN Network Identifier (VNI)      |O| Csum start  |
 42 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 43 *
 44 * C = Remote checksum offload bit. When set indicates that the
 45 *     remote checksum offload data is present.
 46 *
 47 * O = Offset bit. Indicates the checksum offset relative to
 48 *     checksum start.
 49 *
 50 * Csum start = Checksum start divided by two.
 51 *
 52 * http://tools.ietf.org/html/draft-herbert-vxlan-rco
 53 */
 54
 55/* VXLAN-RCO header flags. */
 56#define VXLAN_HF_RCO	cpu_to_be32(BIT(21))
 57
 58/* Remote checksum offload header option */
 59#define VXLAN_RCO_MASK	cpu_to_be32(0x7f)  /* Last byte of vni field */
 60#define VXLAN_RCO_UDP	cpu_to_be32(0x80)  /* Indicate UDP RCO (TCP when not set *) */
 61#define VXLAN_RCO_SHIFT	1		   /* Left shift of start */
 62#define VXLAN_RCO_SHIFT_MASK ((1 << VXLAN_RCO_SHIFT) - 1)
 63#define VXLAN_MAX_REMCSUM_START (0x7f << VXLAN_RCO_SHIFT)
 64
 65/*
 66 * VXLAN Group Based Policy Extension (VXLAN_F_GBP):
 67 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 68 * |G|R|R|R|I|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
 69 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 70 * |                VXLAN Network Identifier (VNI) |   Reserved    |
 71 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 72 *
 73 * G = Group Policy ID present.
 74 *
 75 * D = Don't Learn bit. When set, this bit indicates that the egress
 76 *     VTEP MUST NOT learn the source address of the encapsulated frame.
 77 *
 78 * A = Indicates that the group policy has already been applied to
 79 *     this packet. Policies MUST NOT be applied by devices when the
 80 *     A bit is set.
 81 *
 82 * https://tools.ietf.org/html/draft-smith-vxlan-group-policy
 83 */
 84struct vxlanhdr_gbp {
 85	u8	vx_flags;
 86#ifdef __LITTLE_ENDIAN_BITFIELD
 87	u8	reserved_flags1:3,
 88		policy_applied:1,
 89		reserved_flags2:2,
 90		dont_learn:1,
 91		reserved_flags3:1;
 92#elif defined(__BIG_ENDIAN_BITFIELD)
 93	u8	reserved_flags1:1,
 94		dont_learn:1,
 95		reserved_flags2:2,
 96		policy_applied:1,
 97		reserved_flags3:3;
 98#else
 99#error	"Please fix <asm/byteorder.h>"
100#endif
101	__be16	policy_id;
102	__be32	vx_vni;
103};
104
105/* VXLAN-GBP header flags. */
106#define VXLAN_HF_GBP	cpu_to_be32(BIT(31))
107
108#define VXLAN_GBP_USED_BITS (VXLAN_HF_GBP | cpu_to_be32(0xFFFFFF))
109
110/* skb->mark mapping
111 *
112 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
113 * |R|R|R|R|R|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
114 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
115 */
116#define VXLAN_GBP_DONT_LEARN		(BIT(6) << 16)
117#define VXLAN_GBP_POLICY_APPLIED	(BIT(3) << 16)
118#define VXLAN_GBP_ID_MASK		(0xFFFF)
119
120/*
121 * VXLAN Generic Protocol Extension (VXLAN_F_GPE):
122 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
123 * |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
124 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
125 * |                VXLAN Network Identifier (VNI) |   Reserved    |
126 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
127 *
128 * Ver = Version. Indicates VXLAN GPE protocol version.
129 *
130 * P = Next Protocol Bit. The P bit is set to indicate that the
131 *     Next Protocol field is present.
132 *
133 * O = OAM Flag Bit. The O bit is set to indicate that the packet
134 *     is an OAM packet.
135 *
136 * Next Protocol = This 8 bit field indicates the protocol header
137 * immediately following the VXLAN GPE header.
138 *
139 * https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-01
140 */
141
142struct vxlanhdr_gpe {
143#if defined(__LITTLE_ENDIAN_BITFIELD)
144	u8	oam_flag:1,
145		reserved_flags1:1,
146		np_applied:1,
147		instance_applied:1,
148		version:2,
149		reserved_flags2:2;
150#elif defined(__BIG_ENDIAN_BITFIELD)
151	u8	reserved_flags2:2,
152		version:2,
153		instance_applied:1,
154		np_applied:1,
155		reserved_flags1:1,
156		oam_flag:1;
157#endif
158	u8	reserved_flags3;
159	u8	reserved_flags4;
160	u8	next_protocol;
161	__be32	vx_vni;
162};
163
164/* VXLAN-GPE header flags. */
165#define VXLAN_HF_VER	cpu_to_be32(BIT(29) | BIT(28))
166#define VXLAN_HF_NP	cpu_to_be32(BIT(26))
167#define VXLAN_HF_OAM	cpu_to_be32(BIT(24))
168
169#define VXLAN_GPE_USED_BITS (VXLAN_HF_VER | VXLAN_HF_NP | VXLAN_HF_OAM | \
170			     cpu_to_be32(0xff))
171
172struct vxlan_metadata {
173	u32		gbp;
174};
175
176/* per UDP socket information */
177struct vxlan_sock {
178	struct hlist_node hlist;
179	struct socket	 *sock;
180	struct hlist_head vni_list[VNI_HASH_SIZE];
181	refcount_t	  refcnt;
182	u32		  flags;
183};
184
185union vxlan_addr {
186	struct sockaddr_in sin;
187	struct sockaddr_in6 sin6;
188	struct sockaddr sa;
189};
190
191struct vxlan_rdst {
192	union vxlan_addr	 remote_ip;
193	__be16			 remote_port;
194	__be32			 remote_vni;
195	u32			 remote_ifindex;
196	struct list_head	 list;
197	struct rcu_head		 rcu;
198	struct dst_cache	 dst_cache;
199};
200
201struct vxlan_config {
202	union vxlan_addr	remote_ip;
203	union vxlan_addr	saddr;
204	__be32			vni;
205	int			remote_ifindex;
206	int			mtu;
207	__be16			dst_port;
208	u16			port_min;
209	u16			port_max;
210	u8			tos;
211	u8			ttl;
212	__be32			label;
213	u32			flags;
214	unsigned long		age_interval;
215	unsigned int		addrmax;
216	bool			no_share;
217};
218
219struct vxlan_dev_node {
220	struct hlist_node hlist;
221	struct vxlan_dev *vxlan;
222};
223
224/* Pseudo network device */
225struct vxlan_dev {
226	struct vxlan_dev_node hlist4;	/* vni hash table for IPv4 socket */
227#if IS_ENABLED(CONFIG_IPV6)
228	struct vxlan_dev_node hlist6;	/* vni hash table for IPv6 socket */
229#endif
230	struct list_head  next;		/* vxlan's per namespace list */
231	struct vxlan_sock __rcu *vn4_sock;	/* listening socket for IPv4 */
232#if IS_ENABLED(CONFIG_IPV6)
233	struct vxlan_sock __rcu *vn6_sock;	/* listening socket for IPv6 */
234#endif
235	struct net_device *dev;
236	struct net	  *net;		/* netns for packet i/o */
237	struct vxlan_rdst default_dst;	/* default destination */
238
239	struct timer_list age_timer;
240	spinlock_t	  hash_lock;
241	unsigned int	  addrcnt;
242	struct gro_cells  gro_cells;
243
244	struct vxlan_config	cfg;
245
246	struct hlist_head fdb_head[FDB_HASH_SIZE];
247};
248
249#define VXLAN_F_LEARN			0x01
250#define VXLAN_F_PROXY			0x02
251#define VXLAN_F_RSC			0x04
252#define VXLAN_F_L2MISS			0x08
253#define VXLAN_F_L3MISS			0x10
254#define VXLAN_F_IPV6			0x20
255#define VXLAN_F_UDP_ZERO_CSUM_TX	0x40
256#define VXLAN_F_UDP_ZERO_CSUM6_TX	0x80
257#define VXLAN_F_UDP_ZERO_CSUM6_RX	0x100
258#define VXLAN_F_REMCSUM_TX		0x200
259#define VXLAN_F_REMCSUM_RX		0x400
260#define VXLAN_F_GBP			0x800
261#define VXLAN_F_REMCSUM_NOPARTIAL	0x1000
262#define VXLAN_F_COLLECT_METADATA	0x2000
263#define VXLAN_F_GPE			0x4000
264#define VXLAN_F_IPV6_LINKLOCAL		0x8000
265
266/* Flags that are used in the receive path. These flags must match in
267 * order for a socket to be shareable
268 */
269#define VXLAN_F_RCV_FLAGS		(VXLAN_F_GBP |			\
270					 VXLAN_F_GPE |			\
271					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
272					 VXLAN_F_REMCSUM_RX |		\
273					 VXLAN_F_REMCSUM_NOPARTIAL |	\
274					 VXLAN_F_COLLECT_METADATA)
275
276/* Flags that can be set together with VXLAN_F_GPE. */
277#define VXLAN_F_ALLOWED_GPE		(VXLAN_F_GPE |			\
278					 VXLAN_F_IPV6 |			\
279					 VXLAN_F_IPV6_LINKLOCAL |	\
280					 VXLAN_F_UDP_ZERO_CSUM_TX |	\
281					 VXLAN_F_UDP_ZERO_CSUM6_TX |	\
282					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
283					 VXLAN_F_COLLECT_METADATA)
284
285struct net_device *vxlan_dev_create(struct net *net, const char *name,
286				    u8 name_assign_type, struct vxlan_config *conf);
287
288static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
289						     netdev_features_t features)
290{
291	u8 l4_hdr = 0;
292
293	if (!skb->encapsulation)
294		return features;
295
296	switch (vlan_get_protocol(skb)) {
297	case htons(ETH_P_IP):
298		l4_hdr = ip_hdr(skb)->protocol;
299		break;
300	case htons(ETH_P_IPV6):
301		l4_hdr = ipv6_hdr(skb)->nexthdr;
302		break;
303	default:
304		return features;
305	}
306
307	if ((l4_hdr == IPPROTO_UDP) &&
308	    (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
309	     skb->inner_protocol != htons(ETH_P_TEB) ||
310	     (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
311	      sizeof(struct udphdr) + sizeof(struct vxlanhdr)) ||
312	     (skb->ip_summed != CHECKSUM_NONE &&
313	      !can_checksum_protocol(features, inner_eth_hdr(skb)->h_proto))))
314		return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
315
316	return features;
317}
318
319/* IP header + UDP + VXLAN + Ethernet header */
320#define VXLAN_HEADROOM (20 + 8 + 8 + 14)
321/* IPv6 header + UDP + VXLAN + Ethernet header */
322#define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
323
324static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
325{
326	return (struct vxlanhdr *)(udp_hdr(skb) + 1);
327}
328
329static inline __be32 vxlan_vni(__be32 vni_field)
330{
331#if defined(__BIG_ENDIAN)
332	return (__force __be32)((__force u32)vni_field >> 8);
333#else
334	return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
335#endif
336}
337
338static inline __be32 vxlan_vni_field(__be32 vni)
339{
340#if defined(__BIG_ENDIAN)
341	return (__force __be32)((__force u32)vni << 8);
342#else
343	return (__force __be32)((__force u32)vni >> 8);
344#endif
345}
346
347static inline size_t vxlan_rco_start(__be32 vni_field)
348{
349	return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
350}
351
352static inline size_t vxlan_rco_offset(__be32 vni_field)
353{
354	return (vni_field & VXLAN_RCO_UDP) ?
355		offsetof(struct udphdr, check) :
356		offsetof(struct tcphdr, check);
357}
358
359static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
360{
361	__be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
362
363	if (offset == offsetof(struct udphdr, check))
364		vni_field |= VXLAN_RCO_UDP;
365	return vni_field;
366}
367
368static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
369{
370	return vs->sock->sk->sk_family;
371}
372
373#endif