xref: /openbmc/linux/include/net/vxlan.h (revision 3805e6a1)
1 #ifndef __NET_VXLAN_H
2 #define __NET_VXLAN_H 1
3 
4 #include <linux/ip.h>
5 #include <linux/ipv6.h>
6 #include <linux/if_vlan.h>
7 #include <linux/skbuff.h>
8 #include <linux/netdevice.h>
9 #include <linux/udp.h>
10 #include <net/dst_metadata.h>
11 
12 /* VXLAN protocol (RFC 7348) header:
13  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
14  * |R|R|R|R|I|R|R|R|               Reserved                        |
15  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
16  * |                VXLAN Network Identifier (VNI) |   Reserved    |
17  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
18  *
19  * I = VXLAN Network Identifier (VNI) present.
20  */
21 struct vxlanhdr {
22 	__be32 vx_flags;
23 	__be32 vx_vni;
24 };
25 
26 /* VXLAN header flags. */
27 #define VXLAN_HF_VNI	cpu_to_be32(BIT(27))
28 
29 #define VXLAN_N_VID     (1u << 24)
30 #define VXLAN_VID_MASK  (VXLAN_N_VID - 1)
31 #define VXLAN_VNI_MASK	cpu_to_be32(VXLAN_VID_MASK << 8)
32 #define VXLAN_HLEN (sizeof(struct udphdr) + sizeof(struct vxlanhdr))
33 
34 #define VNI_HASH_BITS	10
35 #define VNI_HASH_SIZE	(1<<VNI_HASH_BITS)
36 #define FDB_HASH_BITS	8
37 #define FDB_HASH_SIZE	(1<<FDB_HASH_BITS)
38 
39 /* Remote checksum offload for VXLAN (VXLAN_F_REMCSUM_[RT]X):
40  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
41  * |R|R|R|R|I|R|R|R|R|R|C|              Reserved                   |
42  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
43  * |           VXLAN Network Identifier (VNI)      |O| Csum start  |
44  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
45  *
46  * C = Remote checksum offload bit. When set indicates that the
47  *     remote checksum offload data is present.
48  *
49  * O = Offset bit. Indicates the checksum offset relative to
50  *     checksum start.
51  *
52  * Csum start = Checksum start divided by two.
53  *
54  * http://tools.ietf.org/html/draft-herbert-vxlan-rco
55  */
56 
57 /* VXLAN-RCO header flags. */
58 #define VXLAN_HF_RCO	cpu_to_be32(BIT(21))
59 
60 /* Remote checksum offload header option */
61 #define VXLAN_RCO_MASK	cpu_to_be32(0x7f)  /* Last byte of vni field */
62 #define VXLAN_RCO_UDP	cpu_to_be32(0x80)  /* Indicate UDP RCO (TCP when not set *) */
63 #define VXLAN_RCO_SHIFT	1		   /* Left shift of start */
64 #define VXLAN_RCO_SHIFT_MASK ((1 << VXLAN_RCO_SHIFT) - 1)
65 #define VXLAN_MAX_REMCSUM_START (0x7f << VXLAN_RCO_SHIFT)
66 
67 /*
68  * VXLAN Group Based Policy Extension (VXLAN_F_GBP):
69  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
70  * |G|R|R|R|I|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
71  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
72  * |                VXLAN Network Identifier (VNI) |   Reserved    |
73  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
74  *
75  * G = Group Policy ID present.
76  *
77  * D = Don't Learn bit. When set, this bit indicates that the egress
78  *     VTEP MUST NOT learn the source address of the encapsulated frame.
79  *
80  * A = Indicates that the group policy has already been applied to
81  *     this packet. Policies MUST NOT be applied by devices when the
82  *     A bit is set.
83  *
84  * https://tools.ietf.org/html/draft-smith-vxlan-group-policy
85  */
86 struct vxlanhdr_gbp {
87 	u8	vx_flags;
88 #ifdef __LITTLE_ENDIAN_BITFIELD
89 	u8	reserved_flags1:3,
90 		policy_applied:1,
91 		reserved_flags2:2,
92 		dont_learn:1,
93 		reserved_flags3:1;
94 #elif defined(__BIG_ENDIAN_BITFIELD)
95 	u8	reserved_flags1:1,
96 		dont_learn:1,
97 		reserved_flags2:2,
98 		policy_applied:1,
99 		reserved_flags3:3;
100 #else
101 #error	"Please fix <asm/byteorder.h>"
102 #endif
103 	__be16	policy_id;
104 	__be32	vx_vni;
105 };
106 
107 /* VXLAN-GBP header flags. */
108 #define VXLAN_HF_GBP	cpu_to_be32(BIT(31))
109 
110 #define VXLAN_GBP_USED_BITS (VXLAN_HF_GBP | cpu_to_be32(0xFFFFFF))
111 
112 /* skb->mark mapping
113  *
114  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
115  * |R|R|R|R|R|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
116  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
117  */
118 #define VXLAN_GBP_DONT_LEARN		(BIT(6) << 16)
119 #define VXLAN_GBP_POLICY_APPLIED	(BIT(3) << 16)
120 #define VXLAN_GBP_ID_MASK		(0xFFFF)
121 
122 /*
123  * VXLAN Generic Protocol Extension (VXLAN_F_GPE):
124  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
125  * |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
126  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
127  * |                VXLAN Network Identifier (VNI) |   Reserved    |
128  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
129  *
130  * Ver = Version. Indicates VXLAN GPE protocol version.
131  *
132  * P = Next Protocol Bit. The P bit is set to indicate that the
133  *     Next Protocol field is present.
134  *
135  * O = OAM Flag Bit. The O bit is set to indicate that the packet
136  *     is an OAM packet.
137  *
138  * Next Protocol = This 8 bit field indicates the protocol header
139  * immediately following the VXLAN GPE header.
140  *
141  * https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-01
142  */
143 
144 struct vxlanhdr_gpe {
145 #if defined(__LITTLE_ENDIAN_BITFIELD)
146 	u8	oam_flag:1,
147 		reserved_flags1:1,
148 		np_applied:1,
149 		instance_applied:1,
150 		version:2,
151 reserved_flags2:2;
152 #elif defined(__BIG_ENDIAN_BITFIELD)
153 	u8	reserved_flags2:2,
154 		version:2,
155 		instance_applied:1,
156 		np_applied:1,
157 		reserved_flags1:1,
158 		oam_flag:1;
159 #endif
160 	u8	reserved_flags3;
161 	u8	reserved_flags4;
162 	u8	next_protocol;
163 	__be32	vx_vni;
164 };
165 
166 /* VXLAN-GPE header flags. */
167 #define VXLAN_HF_VER	cpu_to_be32(BIT(29) | BIT(28))
168 #define VXLAN_HF_NP	cpu_to_be32(BIT(26))
169 #define VXLAN_HF_OAM	cpu_to_be32(BIT(24))
170 
171 #define VXLAN_GPE_USED_BITS (VXLAN_HF_VER | VXLAN_HF_NP | VXLAN_HF_OAM | \
172 			     cpu_to_be32(0xff))
173 
174 /* VXLAN-GPE header Next Protocol. */
175 #define VXLAN_GPE_NP_IPV4      0x01
176 #define VXLAN_GPE_NP_IPV6      0x02
177 #define VXLAN_GPE_NP_ETHERNET  0x03
178 #define VXLAN_GPE_NP_NSH       0x04
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 	atomic_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 	__be32			 remote_vni;
203 	u32			 remote_ifindex;
204 	struct list_head	 list;
205 	struct rcu_head		 rcu;
206 	struct dst_cache	 dst_cache;
207 };
208 
209 struct vxlan_config {
210 	union vxlan_addr	remote_ip;
211 	union vxlan_addr	saddr;
212 	__be32			vni;
213 	int			remote_ifindex;
214 	int			mtu;
215 	__be16			dst_port;
216 	u16			port_min;
217 	u16			port_max;
218 	u8			tos;
219 	u8			ttl;
220 	__be32			label;
221 	u32			flags;
222 	unsigned long		age_interval;
223 	unsigned int		addrmax;
224 	bool			no_share;
225 };
226 
227 /* Pseudo network device */
228 struct vxlan_dev {
229 	struct hlist_node hlist;	/* vni hash table */
230 	struct list_head  next;		/* vxlan's per namespace list */
231 	struct vxlan_sock *vn4_sock;	/* listening socket for IPv4 */
232 #if IS_ENABLED(CONFIG_IPV6)
233 	struct vxlan_sock *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 	u32		  flags;	/* VXLAN_F_* in vxlan.h */
239 
240 	struct timer_list age_timer;
241 	spinlock_t	  hash_lock;
242 	unsigned int	  addrcnt;
243 	struct gro_cells  gro_cells;
244 
245 	struct vxlan_config	cfg;
246 
247 	struct hlist_head fdb_head[FDB_HASH_SIZE];
248 };
249 
250 #define VXLAN_F_LEARN			0x01
251 #define VXLAN_F_PROXY			0x02
252 #define VXLAN_F_RSC			0x04
253 #define VXLAN_F_L2MISS			0x08
254 #define VXLAN_F_L3MISS			0x10
255 #define VXLAN_F_IPV6			0x20
256 #define VXLAN_F_UDP_ZERO_CSUM_TX	0x40
257 #define VXLAN_F_UDP_ZERO_CSUM6_TX	0x80
258 #define VXLAN_F_UDP_ZERO_CSUM6_RX	0x100
259 #define VXLAN_F_REMCSUM_TX		0x200
260 #define VXLAN_F_REMCSUM_RX		0x400
261 #define VXLAN_F_GBP			0x800
262 #define VXLAN_F_REMCSUM_NOPARTIAL	0x1000
263 #define VXLAN_F_COLLECT_METADATA	0x2000
264 #define VXLAN_F_GPE			0x4000
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_UDP_ZERO_CSUM_TX |	\
280 					 VXLAN_F_UDP_ZERO_CSUM6_TX |	\
281 					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
282 					 VXLAN_F_COLLECT_METADATA)
283 
284 struct net_device *vxlan_dev_create(struct net *net, const char *name,
285 				    u8 name_assign_type, struct vxlan_config *conf);
286 
287 static inline __be16 vxlan_dev_dst_port(struct vxlan_dev *vxlan,
288 					unsigned short family)
289 {
290 #if IS_ENABLED(CONFIG_IPV6)
291 	if (family == AF_INET6)
292 		return inet_sk(vxlan->vn6_sock->sock->sk)->inet_sport;
293 #endif
294 	return inet_sk(vxlan->vn4_sock->sock->sk)->inet_sport;
295 }
296 
297 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
298 						     netdev_features_t features)
299 {
300 	u8 l4_hdr = 0;
301 
302 	if (!skb->encapsulation)
303 		return features;
304 
305 	switch (vlan_get_protocol(skb)) {
306 	case htons(ETH_P_IP):
307 		l4_hdr = ip_hdr(skb)->protocol;
308 		break;
309 	case htons(ETH_P_IPV6):
310 		l4_hdr = ipv6_hdr(skb)->nexthdr;
311 		break;
312 	default:
313 		return features;;
314 	}
315 
316 	if ((l4_hdr == IPPROTO_UDP) &&
317 	    (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
318 	     skb->inner_protocol != htons(ETH_P_TEB) ||
319 	     (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
320 	      sizeof(struct udphdr) + sizeof(struct vxlanhdr)) ||
321 	     (skb->ip_summed != CHECKSUM_NONE &&
322 	      !can_checksum_protocol(features, inner_eth_hdr(skb)->h_proto))))
323 		return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
324 
325 	return features;
326 }
327 
328 /* IP header + UDP + VXLAN + Ethernet header */
329 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
330 /* IPv6 header + UDP + VXLAN + Ethernet header */
331 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
332 
333 static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
334 {
335 	return (struct vxlanhdr *)(udp_hdr(skb) + 1);
336 }
337 
338 static inline __be32 vxlan_vni(__be32 vni_field)
339 {
340 #if defined(__BIG_ENDIAN)
341 	return (__force __be32)((__force u32)vni_field >> 8);
342 #else
343 	return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
344 #endif
345 }
346 
347 static inline __be32 vxlan_vni_field(__be32 vni)
348 {
349 #if defined(__BIG_ENDIAN)
350 	return (__force __be32)((__force u32)vni << 8);
351 #else
352 	return (__force __be32)((__force u32)vni >> 8);
353 #endif
354 }
355 
356 static inline __be32 vxlan_tun_id_to_vni(__be64 tun_id)
357 {
358 #if defined(__BIG_ENDIAN)
359 	return (__force __be32)tun_id;
360 #else
361 	return (__force __be32)((__force u64)tun_id >> 32);
362 #endif
363 }
364 
365 static inline __be64 vxlan_vni_to_tun_id(__be32 vni)
366 {
367 #if defined(__BIG_ENDIAN)
368 	return (__force __be64)vni;
369 #else
370 	return (__force __be64)((u64)(__force u32)vni << 32);
371 #endif
372 }
373 
374 static inline size_t vxlan_rco_start(__be32 vni_field)
375 {
376 	return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
377 }
378 
379 static inline size_t vxlan_rco_offset(__be32 vni_field)
380 {
381 	return (vni_field & VXLAN_RCO_UDP) ?
382 		offsetof(struct udphdr, check) :
383 		offsetof(struct tcphdr, check);
384 }
385 
386 static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
387 {
388 	__be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
389 
390 	if (offset == offsetof(struct udphdr, check))
391 		vni_field |= VXLAN_RCO_UDP;
392 	return vni_field;
393 }
394 
395 static inline void vxlan_get_rx_port(struct net_device *netdev)
396 {
397 	ASSERT_RTNL();
398 	call_netdevice_notifiers(NETDEV_OFFLOAD_PUSH_VXLAN, netdev);
399 }
400 
401 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
402 {
403 	return vs->sock->sk->sk_family;
404 }
405 
406 #endif
407