xref: /openbmc/linux/include/net/vxlan.h (revision 0f4630f3)
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 #define VNI_HASH_BITS	10
13 #define VNI_HASH_SIZE	(1<<VNI_HASH_BITS)
14 
15 /*
16  * VXLAN Group Based Policy Extension:
17  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
18  * |1|-|-|-|1|-|-|-|R|D|R|R|A|R|R|R|        Group Policy ID        |
19  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
20  * |                VXLAN Network Identifier (VNI) |   Reserved    |
21  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
22  *
23  * D = Don't Learn bit. When set, this bit indicates that the egress
24  *     VTEP MUST NOT learn the source address of the encapsulated frame.
25  *
26  * A = Indicates that the group policy has already been applied to
27  *     this packet. Policies MUST NOT be applied by devices when the
28  *     A bit is set.
29  *
30  * [0] https://tools.ietf.org/html/draft-smith-vxlan-group-policy
31  */
32 struct vxlanhdr_gbp {
33 	__u8	vx_flags;
34 #ifdef __LITTLE_ENDIAN_BITFIELD
35 	__u8	reserved_flags1:3,
36 		policy_applied:1,
37 		reserved_flags2:2,
38 		dont_learn:1,
39 		reserved_flags3:1;
40 #elif defined(__BIG_ENDIAN_BITFIELD)
41 	__u8	reserved_flags1:1,
42 		dont_learn:1,
43 		reserved_flags2:2,
44 		policy_applied:1,
45 		reserved_flags3:3;
46 #else
47 #error	"Please fix <asm/byteorder.h>"
48 #endif
49 	__be16	policy_id;
50 	__be32	vx_vni;
51 };
52 
53 #define VXLAN_GBP_USED_BITS (VXLAN_HF_GBP | 0xFFFFFF)
54 
55 /* skb->mark mapping
56  *
57  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
58  * |R|R|R|R|R|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
59  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
60  */
61 #define VXLAN_GBP_DONT_LEARN		(BIT(6) << 16)
62 #define VXLAN_GBP_POLICY_APPLIED	(BIT(3) << 16)
63 #define VXLAN_GBP_ID_MASK		(0xFFFF)
64 
65 /* VXLAN protocol header:
66  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
67  * |G|R|R|R|I|R|R|C|               Reserved                        |
68  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
69  * |                VXLAN Network Identifier (VNI) |   Reserved    |
70  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
71  *
72  * G = 1	Group Policy (VXLAN-GBP)
73  * I = 1	VXLAN Network Identifier (VNI) present
74  * C = 1	Remote checksum offload (RCO)
75  */
76 struct vxlanhdr {
77 	__be32 vx_flags;
78 	__be32 vx_vni;
79 };
80 
81 /* VXLAN header flags. */
82 #define VXLAN_HF_RCO BIT(21)
83 #define VXLAN_HF_VNI BIT(27)
84 #define VXLAN_HF_GBP BIT(31)
85 
86 /* Remote checksum offload header option */
87 #define VXLAN_RCO_MASK  0x7f    /* Last byte of vni field */
88 #define VXLAN_RCO_UDP   0x80    /* Indicate UDP RCO (TCP when not set *) */
89 #define VXLAN_RCO_SHIFT 1       /* Left shift of start */
90 #define VXLAN_RCO_SHIFT_MASK ((1 << VXLAN_RCO_SHIFT) - 1)
91 #define VXLAN_MAX_REMCSUM_START (VXLAN_RCO_MASK << VXLAN_RCO_SHIFT)
92 
93 #define VXLAN_N_VID     (1u << 24)
94 #define VXLAN_VID_MASK  (VXLAN_N_VID - 1)
95 #define VXLAN_VNI_MASK  (VXLAN_VID_MASK << 8)
96 #define VXLAN_HLEN (sizeof(struct udphdr) + sizeof(struct vxlanhdr))
97 
98 #define VNI_HASH_BITS	10
99 #define VNI_HASH_SIZE	(1<<VNI_HASH_BITS)
100 #define FDB_HASH_BITS	8
101 #define FDB_HASH_SIZE	(1<<FDB_HASH_BITS)
102 
103 struct vxlan_metadata {
104 	u32		gbp;
105 };
106 
107 /* per UDP socket information */
108 struct vxlan_sock {
109 	struct hlist_node hlist;
110 	struct work_struct del_work;
111 	struct socket	 *sock;
112 	struct rcu_head	  rcu;
113 	struct hlist_head vni_list[VNI_HASH_SIZE];
114 	atomic_t	  refcnt;
115 	struct udp_offload udp_offloads;
116 	u32		  flags;
117 };
118 
119 union vxlan_addr {
120 	struct sockaddr_in sin;
121 	struct sockaddr_in6 sin6;
122 	struct sockaddr sa;
123 };
124 
125 struct vxlan_rdst {
126 	union vxlan_addr	 remote_ip;
127 	__be16			 remote_port;
128 	u32			 remote_vni;
129 	u32			 remote_ifindex;
130 	struct list_head	 list;
131 	struct rcu_head		 rcu;
132 };
133 
134 struct vxlan_config {
135 	union vxlan_addr	remote_ip;
136 	union vxlan_addr	saddr;
137 	u32			vni;
138 	int			remote_ifindex;
139 	int			mtu;
140 	__be16			dst_port;
141 	__u16			port_min;
142 	__u16			port_max;
143 	__u8			tos;
144 	__u8			ttl;
145 	u32			flags;
146 	unsigned long		age_interval;
147 	unsigned int		addrmax;
148 	bool			no_share;
149 };
150 
151 /* Pseudo network device */
152 struct vxlan_dev {
153 	struct hlist_node hlist;	/* vni hash table */
154 	struct list_head  next;		/* vxlan's per namespace list */
155 	struct vxlan_sock *vn4_sock;	/* listening socket for IPv4 */
156 #if IS_ENABLED(CONFIG_IPV6)
157 	struct vxlan_sock *vn6_sock;	/* listening socket for IPv6 */
158 #endif
159 	struct net_device *dev;
160 	struct net	  *net;		/* netns for packet i/o */
161 	struct vxlan_rdst default_dst;	/* default destination */
162 	u32		  flags;	/* VXLAN_F_* in vxlan.h */
163 
164 	struct timer_list age_timer;
165 	spinlock_t	  hash_lock;
166 	unsigned int	  addrcnt;
167 	struct gro_cells  gro_cells;
168 
169 	struct vxlan_config	cfg;
170 
171 	struct hlist_head fdb_head[FDB_HASH_SIZE];
172 };
173 
174 #define VXLAN_F_LEARN			0x01
175 #define VXLAN_F_PROXY			0x02
176 #define VXLAN_F_RSC			0x04
177 #define VXLAN_F_L2MISS			0x08
178 #define VXLAN_F_L3MISS			0x10
179 #define VXLAN_F_IPV6			0x20
180 #define VXLAN_F_UDP_CSUM		0x40
181 #define VXLAN_F_UDP_ZERO_CSUM6_TX	0x80
182 #define VXLAN_F_UDP_ZERO_CSUM6_RX	0x100
183 #define VXLAN_F_REMCSUM_TX		0x200
184 #define VXLAN_F_REMCSUM_RX		0x400
185 #define VXLAN_F_GBP			0x800
186 #define VXLAN_F_REMCSUM_NOPARTIAL	0x1000
187 #define VXLAN_F_COLLECT_METADATA	0x2000
188 
189 /* Flags that are used in the receive path. These flags must match in
190  * order for a socket to be shareable
191  */
192 #define VXLAN_F_RCV_FLAGS		(VXLAN_F_GBP |			\
193 					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
194 					 VXLAN_F_REMCSUM_RX |		\
195 					 VXLAN_F_REMCSUM_NOPARTIAL |	\
196 					 VXLAN_F_COLLECT_METADATA)
197 
198 struct net_device *vxlan_dev_create(struct net *net, const char *name,
199 				    u8 name_assign_type, struct vxlan_config *conf);
200 
201 static inline __be16 vxlan_dev_dst_port(struct vxlan_dev *vxlan,
202 					unsigned short family)
203 {
204 #if IS_ENABLED(CONFIG_IPV6)
205 	if (family == AF_INET6)
206 		return inet_sk(vxlan->vn6_sock->sock->sk)->inet_sport;
207 #endif
208 	return inet_sk(vxlan->vn4_sock->sock->sk)->inet_sport;
209 }
210 
211 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
212 						     netdev_features_t features)
213 {
214 	u8 l4_hdr = 0;
215 
216 	if (!skb->encapsulation)
217 		return features;
218 
219 	switch (vlan_get_protocol(skb)) {
220 	case htons(ETH_P_IP):
221 		l4_hdr = ip_hdr(skb)->protocol;
222 		break;
223 	case htons(ETH_P_IPV6):
224 		l4_hdr = ipv6_hdr(skb)->nexthdr;
225 		break;
226 	default:
227 		return features;;
228 	}
229 
230 	if ((l4_hdr == IPPROTO_UDP) &&
231 	    (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
232 	     skb->inner_protocol != htons(ETH_P_TEB) ||
233 	     (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
234 	      sizeof(struct udphdr) + sizeof(struct vxlanhdr))))
235 		return features & ~(NETIF_F_ALL_CSUM | NETIF_F_GSO_MASK);
236 
237 	return features;
238 }
239 
240 /* IP header + UDP + VXLAN + Ethernet header */
241 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
242 /* IPv6 header + UDP + VXLAN + Ethernet header */
243 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
244 
245 #if IS_ENABLED(CONFIG_VXLAN)
246 void vxlan_get_rx_port(struct net_device *netdev);
247 #else
248 static inline void vxlan_get_rx_port(struct net_device *netdev)
249 {
250 }
251 #endif
252 
253 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
254 {
255 	return vs->sock->sk->sk_family;
256 }
257 
258 #endif
259