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Linux kernel mirror (for testing)
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linux
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#define VXLAN_F_TTL_INHERIT 0x10000
266
267/* Flags that are used in the receive path. These flags must match in
268 * order for a socket to be shareable
269 */
270#define VXLAN_F_RCV_FLAGS (VXLAN_F_GBP | \
271 VXLAN_F_GPE | \
272 VXLAN_F_UDP_ZERO_CSUM6_RX | \
273 VXLAN_F_REMCSUM_RX | \
274 VXLAN_F_REMCSUM_NOPARTIAL | \
275 VXLAN_F_COLLECT_METADATA)
276
277/* Flags that can be set together with VXLAN_F_GPE. */
278#define VXLAN_F_ALLOWED_GPE (VXLAN_F_GPE | \
279 VXLAN_F_IPV6 | \
280 VXLAN_F_IPV6_LINKLOCAL | \
281 VXLAN_F_UDP_ZERO_CSUM_TX | \
282 VXLAN_F_UDP_ZERO_CSUM6_TX | \
283 VXLAN_F_UDP_ZERO_CSUM6_RX | \
284 VXLAN_F_COLLECT_METADATA)
285
286struct net_device *vxlan_dev_create(struct net *net, const char *name,
287 u8 name_assign_type, struct vxlan_config *conf);
288
289static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
290 netdev_features_t features)
291{
292 u8 l4_hdr = 0;
293
294 if (!skb->encapsulation)
295 return features;
296
297 switch (vlan_get_protocol(skb)) {
298 case htons(ETH_P_IP):
299 l4_hdr = ip_hdr(skb)->protocol;
300 break;
301 case htons(ETH_P_IPV6):
302 l4_hdr = ipv6_hdr(skb)->nexthdr;
303 break;
304 default:
305 return features;
306 }
307
308 if ((l4_hdr == IPPROTO_UDP) &&
309 (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
310 skb->inner_protocol != htons(ETH_P_TEB) ||
311 (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
312 sizeof(struct udphdr) + sizeof(struct vxlanhdr)) ||
313 (skb->ip_summed != CHECKSUM_NONE &&
314 !can_checksum_protocol(features, inner_eth_hdr(skb)->h_proto))))
315 return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
316
317 return features;
318}
319
320/* IP header + UDP + VXLAN + Ethernet header */
321#define VXLAN_HEADROOM (20 + 8 + 8 + 14)
322/* IPv6 header + UDP + VXLAN + Ethernet header */
323#define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
324
325static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
326{
327 return (struct vxlanhdr *)(udp_hdr(skb) + 1);
328}
329
330static inline __be32 vxlan_vni(__be32 vni_field)
331{
332#if defined(__BIG_ENDIAN)
333 return (__force __be32)((__force u32)vni_field >> 8);
334#else
335 return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
336#endif
337}
338
339static inline __be32 vxlan_vni_field(__be32 vni)
340{
341#if defined(__BIG_ENDIAN)
342 return (__force __be32)((__force u32)vni << 8);
343#else
344 return (__force __be32)((__force u32)vni >> 8);
345#endif
346}
347
348static inline size_t vxlan_rco_start(__be32 vni_field)
349{
350 return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
351}
352
353static inline size_t vxlan_rco_offset(__be32 vni_field)
354{
355 return (vni_field & VXLAN_RCO_UDP) ?
356 offsetof(struct udphdr, check) :
357 offsetof(struct tcphdr, check);
358}
359
360static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
361{
362 __be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
363
364 if (offset == offsetof(struct udphdr, check))
365 vni_field |= VXLAN_RCO_UDP;
366 return vni_field;
367}
368
369static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
370{
371 return vs->sock->sk->sk_family;
372}
373
374#endif