xref: /linux-6.15/include/net/vxlan.h (revision 87aca737)
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 BIT(27)
28 
29 #define VXLAN_N_VID     (1u << 24)
30 #define VXLAN_VID_MASK  (VXLAN_N_VID - 1)
31 #define VXLAN_VNI_MASK  (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 BIT(21)
59 
60 /* Remote checksum offload header option */
61 #define VXLAN_RCO_MASK  0x7f    /* Last byte of vni field */
62 #define VXLAN_RCO_UDP   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 (VXLAN_RCO_MASK << 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 BIT(31)
109 
110 #define VXLAN_GBP_USED_BITS (VXLAN_HF_GBP | 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 	u32			 remote_vni;
148 	u32			 remote_ifindex;
149 	struct list_head	 list;
150 	struct rcu_head		 rcu;
151 };
152 
153 struct vxlan_config {
154 	union vxlan_addr	remote_ip;
155 	union vxlan_addr	saddr;
156 	u32			vni;
157 	int			remote_ifindex;
158 	int			mtu;
159 	__be16			dst_port;
160 	u16			port_min;
161 	u16			port_max;
162 	u8			tos;
163 	u8			ttl;
164 	u32			flags;
165 	unsigned long		age_interval;
166 	unsigned int		addrmax;
167 	bool			no_share;
168 };
169 
170 /* Pseudo network device */
171 struct vxlan_dev {
172 	struct hlist_node hlist;	/* vni hash table */
173 	struct list_head  next;		/* vxlan's per namespace list */
174 	struct vxlan_sock *vn4_sock;	/* listening socket for IPv4 */
175 #if IS_ENABLED(CONFIG_IPV6)
176 	struct vxlan_sock *vn6_sock;	/* listening socket for IPv6 */
177 #endif
178 	struct net_device *dev;
179 	struct net	  *net;		/* netns for packet i/o */
180 	struct vxlan_rdst default_dst;	/* default destination */
181 	u32		  flags;	/* VXLAN_F_* in vxlan.h */
182 
183 	struct timer_list age_timer;
184 	spinlock_t	  hash_lock;
185 	unsigned int	  addrcnt;
186 	struct gro_cells  gro_cells;
187 
188 	struct vxlan_config	cfg;
189 
190 	struct hlist_head fdb_head[FDB_HASH_SIZE];
191 };
192 
193 #define VXLAN_F_LEARN			0x01
194 #define VXLAN_F_PROXY			0x02
195 #define VXLAN_F_RSC			0x04
196 #define VXLAN_F_L2MISS			0x08
197 #define VXLAN_F_L3MISS			0x10
198 #define VXLAN_F_IPV6			0x20
199 #define VXLAN_F_UDP_CSUM		0x40
200 #define VXLAN_F_UDP_ZERO_CSUM6_TX	0x80
201 #define VXLAN_F_UDP_ZERO_CSUM6_RX	0x100
202 #define VXLAN_F_REMCSUM_TX		0x200
203 #define VXLAN_F_REMCSUM_RX		0x400
204 #define VXLAN_F_GBP			0x800
205 #define VXLAN_F_REMCSUM_NOPARTIAL	0x1000
206 #define VXLAN_F_COLLECT_METADATA	0x2000
207 
208 /* Flags that are used in the receive path. These flags must match in
209  * order for a socket to be shareable
210  */
211 #define VXLAN_F_RCV_FLAGS		(VXLAN_F_GBP |			\
212 					 VXLAN_F_UDP_ZERO_CSUM6_RX |	\
213 					 VXLAN_F_REMCSUM_RX |		\
214 					 VXLAN_F_REMCSUM_NOPARTIAL |	\
215 					 VXLAN_F_COLLECT_METADATA)
216 
217 struct net_device *vxlan_dev_create(struct net *net, const char *name,
218 				    u8 name_assign_type, struct vxlan_config *conf);
219 
220 static inline __be16 vxlan_dev_dst_port(struct vxlan_dev *vxlan,
221 					unsigned short family)
222 {
223 #if IS_ENABLED(CONFIG_IPV6)
224 	if (family == AF_INET6)
225 		return inet_sk(vxlan->vn6_sock->sock->sk)->inet_sport;
226 #endif
227 	return inet_sk(vxlan->vn4_sock->sock->sk)->inet_sport;
228 }
229 
230 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
231 						     netdev_features_t features)
232 {
233 	u8 l4_hdr = 0;
234 
235 	if (!skb->encapsulation)
236 		return features;
237 
238 	switch (vlan_get_protocol(skb)) {
239 	case htons(ETH_P_IP):
240 		l4_hdr = ip_hdr(skb)->protocol;
241 		break;
242 	case htons(ETH_P_IPV6):
243 		l4_hdr = ipv6_hdr(skb)->nexthdr;
244 		break;
245 	default:
246 		return features;;
247 	}
248 
249 	if ((l4_hdr == IPPROTO_UDP) &&
250 	    (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
251 	     skb->inner_protocol != htons(ETH_P_TEB) ||
252 	     (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
253 	      sizeof(struct udphdr) + sizeof(struct vxlanhdr))))
254 		return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
255 
256 	return features;
257 }
258 
259 /* IP header + UDP + VXLAN + Ethernet header */
260 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
261 /* IPv6 header + UDP + VXLAN + Ethernet header */
262 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
263 
264 #if IS_ENABLED(CONFIG_VXLAN)
265 void vxlan_get_rx_port(struct net_device *netdev);
266 #else
267 static inline void vxlan_get_rx_port(struct net_device *netdev)
268 {
269 }
270 #endif
271 
272 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
273 {
274 	return vs->sock->sk->sk_family;
275 }
276 
277 #endif
278