xref: /openbmc/linux/include/net/vxlan.h (revision 3e26a691)
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 struct vxlan_metadata {
123 	u32		gbp;
124 };
125 
126 /* per UDP socket information */
127 struct vxlan_sock {
128 	struct hlist_node hlist;
129 	struct work_struct del_work;
130 	struct socket	 *sock;
131 	struct rcu_head	  rcu;
132 	struct hlist_head vni_list[VNI_HASH_SIZE];
133 	atomic_t	  refcnt;
134 	struct udp_offload udp_offloads;
135 	u32		  flags;
136 };
137 
138 union vxlan_addr {
139 	struct sockaddr_in sin;
140 	struct sockaddr_in6 sin6;
141 	struct sockaddr sa;
142 };
143 
144 struct vxlan_rdst {
145 	union vxlan_addr	 remote_ip;
146 	__be16			 remote_port;
147 	__be32			 remote_vni;
148 	u32			 remote_ifindex;
149 	struct list_head	 list;
150 	struct rcu_head		 rcu;
151 	struct dst_cache	 dst_cache;
152 };
153 
154 struct vxlan_config {
155 	union vxlan_addr	remote_ip;
156 	union vxlan_addr	saddr;
157 	__be32			vni;
158 	int			remote_ifindex;
159 	int			mtu;
160 	__be16			dst_port;
161 	u16			port_min;
162 	u16			port_max;
163 	u8			tos;
164 	u8			ttl;
165 	__be32			label;
166 	u32			flags;
167 	unsigned long		age_interval;
168 	unsigned int		addrmax;
169 	bool			no_share;
170 };
171 
172 /* Pseudo network device */
173 struct vxlan_dev {
174 	struct hlist_node hlist;	/* vni hash table */
175 	struct list_head  next;		/* vxlan's per namespace list */
176 	struct vxlan_sock *vn4_sock;	/* listening socket for IPv4 */
177 #if IS_ENABLED(CONFIG_IPV6)
178 	struct vxlan_sock *vn6_sock;	/* listening socket for IPv6 */
179 #endif
180 	struct net_device *dev;
181 	struct net	  *net;		/* netns for packet i/o */
182 	struct vxlan_rdst default_dst;	/* default destination */
183 	u32		  flags;	/* VXLAN_F_* in vxlan.h */
184 
185 	struct timer_list age_timer;
186 	spinlock_t	  hash_lock;
187 	unsigned int	  addrcnt;
188 	struct gro_cells  gro_cells;
189 
190 	struct vxlan_config	cfg;
191 
192 	struct hlist_head fdb_head[FDB_HASH_SIZE];
193 };
194 
195 #define VXLAN_F_LEARN			0x01
196 #define VXLAN_F_PROXY			0x02
197 #define VXLAN_F_RSC			0x04
198 #define VXLAN_F_L2MISS			0x08
199 #define VXLAN_F_L3MISS			0x10
200 #define VXLAN_F_IPV6			0x20
201 #define VXLAN_F_UDP_ZERO_CSUM_TX	0x40
202 #define VXLAN_F_UDP_ZERO_CSUM6_TX	0x80
203 #define VXLAN_F_UDP_ZERO_CSUM6_RX	0x100
204 #define VXLAN_F_REMCSUM_TX		0x200
205 #define VXLAN_F_REMCSUM_RX		0x400
206 #define VXLAN_F_GBP			0x800
207 #define VXLAN_F_REMCSUM_NOPARTIAL	0x1000
208 #define VXLAN_F_COLLECT_METADATA	0x2000
209 
210 /* Flags that are used in the receive path. These flags must match in
211  * order for a socket to be shareable
212  */
213 #define VXLAN_F_RCV_FLAGS		(VXLAN_F_GBP |			\
214 					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
215 					 VXLAN_F_REMCSUM_RX |		\
216 					 VXLAN_F_REMCSUM_NOPARTIAL |	\
217 					 VXLAN_F_COLLECT_METADATA)
218 
219 struct net_device *vxlan_dev_create(struct net *net, const char *name,
220 				    u8 name_assign_type, struct vxlan_config *conf);
221 
222 static inline __be16 vxlan_dev_dst_port(struct vxlan_dev *vxlan,
223 					unsigned short family)
224 {
225 #if IS_ENABLED(CONFIG_IPV6)
226 	if (family == AF_INET6)
227 		return inet_sk(vxlan->vn6_sock->sock->sk)->inet_sport;
228 #endif
229 	return inet_sk(vxlan->vn4_sock->sock->sk)->inet_sport;
230 }
231 
232 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
233 						     netdev_features_t features)
234 {
235 	u8 l4_hdr = 0;
236 
237 	if (!skb->encapsulation)
238 		return features;
239 
240 	switch (vlan_get_protocol(skb)) {
241 	case htons(ETH_P_IP):
242 		l4_hdr = ip_hdr(skb)->protocol;
243 		break;
244 	case htons(ETH_P_IPV6):
245 		l4_hdr = ipv6_hdr(skb)->nexthdr;
246 		break;
247 	default:
248 		return features;;
249 	}
250 
251 	if ((l4_hdr == IPPROTO_UDP) &&
252 	    (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
253 	     skb->inner_protocol != htons(ETH_P_TEB) ||
254 	     (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
255 	      sizeof(struct udphdr) + sizeof(struct vxlanhdr))))
256 		return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
257 
258 	return features;
259 }
260 
261 /* IP header + UDP + VXLAN + Ethernet header */
262 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
263 /* IPv6 header + UDP + VXLAN + Ethernet header */
264 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
265 
266 static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
267 {
268 	return (struct vxlanhdr *)(udp_hdr(skb) + 1);
269 }
270 
271 static inline __be32 vxlan_vni(__be32 vni_field)
272 {
273 #if defined(__BIG_ENDIAN)
274 	return (__force __be32)((__force u32)vni_field >> 8);
275 #else
276 	return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
277 #endif
278 }
279 
280 static inline __be32 vxlan_vni_field(__be32 vni)
281 {
282 #if defined(__BIG_ENDIAN)
283 	return (__force __be32)((__force u32)vni << 8);
284 #else
285 	return (__force __be32)((__force u32)vni >> 8);
286 #endif
287 }
288 
289 static inline __be32 vxlan_tun_id_to_vni(__be64 tun_id)
290 {
291 #if defined(__BIG_ENDIAN)
292 	return (__force __be32)tun_id;
293 #else
294 	return (__force __be32)((__force u64)tun_id >> 32);
295 #endif
296 }
297 
298 static inline __be64 vxlan_vni_to_tun_id(__be32 vni)
299 {
300 #if defined(__BIG_ENDIAN)
301 	return (__force __be64)vni;
302 #else
303 	return (__force __be64)((u64)(__force u32)vni << 32);
304 #endif
305 }
306 
307 static inline size_t vxlan_rco_start(__be32 vni_field)
308 {
309 	return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
310 }
311 
312 static inline size_t vxlan_rco_offset(__be32 vni_field)
313 {
314 	return (vni_field & VXLAN_RCO_UDP) ?
315 		offsetof(struct udphdr, check) :
316 		offsetof(struct tcphdr, check);
317 }
318 
319 static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
320 {
321 	__be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
322 
323 	if (offset == offsetof(struct udphdr, check))
324 		vni_field |= VXLAN_RCO_UDP;
325 	return vni_field;
326 }
327 
328 #if IS_ENABLED(CONFIG_VXLAN)
329 void vxlan_get_rx_port(struct net_device *netdev);
330 #else
331 static inline void vxlan_get_rx_port(struct net_device *netdev)
332 {
333 }
334 #endif
335 
336 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
337 {
338 	return vs->sock->sk->sk_family;
339 }
340 
341 #endif
342