include/net/vxlan.h

   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/rtnetlink.h>
   9 #include <net/switchdev.h>
  10
  11 /* VXLAN protocol (RFC 7348) header:
  12  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  13  * |R|R|R|R|I|R|R|R|               Reserved                        |
  14  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  15  * |                VXLAN Network Identifier (VNI) |   Reserved    |
  16  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  17  *
  18  * I = VXLAN Network Identifier (VNI) present.
  19  */
  20 struct vxlanhdr {
  21         __be32 vx_flags;
  22         __be32 vx_vni;
  23 };
  24
  25 /* VXLAN header flags. */
  26 #define VXLAN_HF_VNI    cpu_to_be32(BIT(27))
  27
  28 #define VXLAN_N_VID     (1u << 24)
  29 #define VXLAN_VID_MASK  (VXLAN_N_VID - 1)
  30 #define VXLAN_VNI_MASK  cpu_to_be32(VXLAN_VID_MASK << 8)
  31 #define VXLAN_HLEN (sizeof(struct udphdr) + sizeof(struct vxlanhdr))
  32
  33 #define VNI_HASH_BITS   10
  34 #define VNI_HASH_SIZE   (1<<VNI_HASH_BITS)
  35 #define FDB_HASH_BITS   8
  36 #define FDB_HASH_SIZE   (1<<FDB_HASH_BITS)
  37
  38 /* Remote checksum offload for VXLAN (VXLAN_F_REMCSUM_[RT]X):
  39  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  40  * |R|R|R|R|I|R|R|R|R|R|C|              Reserved                   |
  41  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  42  * |           VXLAN Network Identifier (VNI)      |O| Csum start  |
  43  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  44  *
  45  * C = Remote checksum offload bit. When set indicates that the
  46  *     remote checksum offload data is present.
  47  *
  48  * O = Offset bit. Indicates the checksum offset relative to
  49  *     checksum start.
  50  *
  51  * Csum start = Checksum start divided by two.
  52  *
  53  * http://tools.ietf.org/html/draft-herbert-vxlan-rco
  54  */
  55
  56 /* VXLAN-RCO header flags. */
  57 #define VXLAN_HF_RCO    cpu_to_be32(BIT(21))
  58
  59 /* Remote checksum offload header option */
  60 #define VXLAN_RCO_MASK  cpu_to_be32(0x7f)  /* Last byte of vni field */
  61 #define VXLAN_RCO_UDP   cpu_to_be32(0x80)  /* Indicate UDP RCO (TCP when not set *) */
  62 #define VXLAN_RCO_SHIFT 1                  /* Left shift of start */
  63 #define VXLAN_RCO_SHIFT_MASK ((1 << VXLAN_RCO_SHIFT) - 1)
  64 #define VXLAN_MAX_REMCSUM_START (0x7f << VXLAN_RCO_SHIFT)
  65
  66 /*
  67  * VXLAN Group Based Policy Extension (VXLAN_F_GBP):
  68  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  69  * |G|R|R|R|I|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
  70  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  71  * |                VXLAN Network Identifier (VNI) |   Reserved    |
  72  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  73  *
  74  * G = Group Policy ID present.
  75  *
  76  * D = Don't Learn bit. When set, this bit indicates that the egress
  77  *     VTEP MUST NOT learn the source address of the encapsulated frame.
  78  *
  79  * A = Indicates that the group policy has already been applied to
  80  *     this packet. Policies MUST NOT be applied by devices when the
  81  *     A bit is set.
  82  *
  83  * https://tools.ietf.org/html/draft-smith-vxlan-group-policy
  84  */
  85 struct vxlanhdr_gbp {
  86         u8      vx_flags;
  87 #ifdef __LITTLE_ENDIAN_BITFIELD
  88         u8      reserved_flags1:3,
  89                 policy_applied:1,
  90                 reserved_flags2:2,
  91                 dont_learn:1,
  92                 reserved_flags3:1;
  93 #elif defined(__BIG_ENDIAN_BITFIELD)
  94         u8      reserved_flags1:1,
  95                 dont_learn:1,
  96                 reserved_flags2:2,
  97                 policy_applied:1,
  98                 reserved_flags3:3;
  99 #else
 100 #error  "Please fix <asm/byteorder.h>"
 101 #endif
 102         __be16  policy_id;
 103         __be32  vx_vni;
 104 };
 105
 106 /* VXLAN-GBP header flags. */
 107 #define VXLAN_HF_GBP    cpu_to_be32(BIT(31))
 108
 109 #define VXLAN_GBP_USED_BITS (VXLAN_HF_GBP | cpu_to_be32(0xFFFFFF))
 110
 111 /* skb->mark mapping
 112  *
 113  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 114  * |R|R|R|R|R|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
 115  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 116  */
 117 #define VXLAN_GBP_DONT_LEARN            (BIT(6) << 16)
 118 #define VXLAN_GBP_POLICY_APPLIED        (BIT(3) << 16)
 119 #define VXLAN_GBP_ID_MASK               (0xFFFF)
 120
 121 /*
 122  * VXLAN Generic Protocol Extension (VXLAN_F_GPE):
 123  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 124  * |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
 125  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 126  * |                VXLAN Network Identifier (VNI) |   Reserved    |
 127  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 128  *
 129  * Ver = Version. Indicates VXLAN GPE protocol version.
 130  *
 131  * P = Next Protocol Bit. The P bit is set to indicate that the
 132  *     Next Protocol field is present.
 133  *
 134  * O = OAM Flag Bit. The O bit is set to indicate that the packet
 135  *     is an OAM packet.
 136  *
 137  * Next Protocol = This 8 bit field indicates the protocol header
 138  * immediately following the VXLAN GPE header.
 139  *
 140  * https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-01
 141  */
 142
 143 struct vxlanhdr_gpe {
 144 #if defined(__LITTLE_ENDIAN_BITFIELD)
 145         u8      oam_flag:1,
 146                 reserved_flags1:1,
 147                 np_applied:1,
 148                 instance_applied:1,
 149                 version:2,
 150                 reserved_flags2:2;
 151 #elif defined(__BIG_ENDIAN_BITFIELD)
 152         u8      reserved_flags2:2,
 153                 version:2,
 154                 instance_applied:1,
 155                 np_applied:1,
 156                 reserved_flags1:1,
 157                 oam_flag:1;
 158 #endif
 159         u8      reserved_flags3;
 160         u8      reserved_flags4;
 161         u8      next_protocol;
 162         __be32  vx_vni;
 163 };
 164
 165 /* VXLAN-GPE header flags. */
 166 #define VXLAN_HF_VER    cpu_to_be32(BIT(29) | BIT(28))
 167 #define VXLAN_HF_NP     cpu_to_be32(BIT(26))
 168 #define VXLAN_HF_OAM    cpu_to_be32(BIT(24))
 169
 170 #define VXLAN_GPE_USED_BITS (VXLAN_HF_VER | VXLAN_HF_NP | VXLAN_HF_OAM | \
 171                              cpu_to_be32(0xff))
 172
 173 struct vxlan_metadata {
 174         u32             gbp;
 175 };
 176
 177 /* per UDP socket information */
 178 struct vxlan_sock {
 179         struct hlist_node hlist;
 180         struct socket    *sock;
 181         struct hlist_head vni_list[VNI_HASH_SIZE];
 182         refcount_t        refcnt;
 183         u32               flags;
 184 };
 185
 186 union vxlan_addr {
 187         struct sockaddr_in sin;
 188         struct sockaddr_in6 sin6;
 189         struct sockaddr sa;
 190 };
 191
 192 struct vxlan_rdst {
 193         union vxlan_addr         remote_ip;
 194         __be16                   remote_port;
 195         u8                       offloaded:1;
 196         __be32                   remote_vni;
 197         u32                      remote_ifindex;
 198         struct list_head         list;
 199         struct rcu_head          rcu;
 200         struct dst_cache         dst_cache;
 201 };
 202
 203 struct vxlan_config {
 204         union vxlan_addr        remote_ip;
 205         union vxlan_addr        saddr;
 206         __be32                  vni;
 207         int                     remote_ifindex;
 208         int                     mtu;
 209         __be16                  dst_port;
 210         u16                     port_min;
 211         u16                     port_max;
 212         u8                      tos;
 213         u8                      ttl;
 214         __be32                  label;
 215         u32                     flags;
 216         unsigned long           age_interval;
 217         unsigned int            addrmax;
 218         bool                    no_share;
 219 };
 220
 221 struct vxlan_dev_node {
 222         struct hlist_node hlist;
 223         struct vxlan_dev *vxlan;
 224 };
 225
 226 /* Pseudo network device */
 227 struct vxlan_dev {
 228         struct vxlan_dev_node hlist4;   /* vni hash table for IPv4 socket */
 229 #if IS_ENABLED(CONFIG_IPV6)
 230         struct vxlan_dev_node hlist6;   /* vni hash table for IPv6 socket */
 231 #endif
 232         struct list_head  next;         /* vxlan's per namespace list */
 233         struct vxlan_sock __rcu *vn4_sock;      /* listening socket for IPv4 */
 234 #if IS_ENABLED(CONFIG_IPV6)
 235         struct vxlan_sock __rcu *vn6_sock;      /* listening socket for IPv6 */
 236 #endif
 237         struct net_device *dev;
 238         struct net        *net;         /* netns for packet i/o */
 239         struct vxlan_rdst default_dst;  /* default destination */
 240
 241         struct timer_list age_timer;
 242         spinlock_t        hash_lock;
 243         unsigned int      addrcnt;
 244         struct gro_cells  gro_cells;
 245
 246         struct vxlan_config     cfg;
 247
 248         struct hlist_head fdb_head[FDB_HASH_SIZE];
 249 };
 250
 251 #define VXLAN_F_LEARN                   0x01
 252 #define VXLAN_F_PROXY                   0x02
 253 #define VXLAN_F_RSC                     0x04
 254 #define VXLAN_F_L2MISS                  0x08
 255 #define VXLAN_F_L3MISS                  0x10
 256 #define VXLAN_F_IPV6                    0x20
 257 #define VXLAN_F_UDP_ZERO_CSUM_TX        0x40
 258 #define VXLAN_F_UDP_ZERO_CSUM6_TX       0x80
 259 #define VXLAN_F_UDP_ZERO_CSUM6_RX       0x100
 260 #define VXLAN_F_REMCSUM_TX              0x200
 261 #define VXLAN_F_REMCSUM_RX              0x400
 262 #define VXLAN_F_GBP                     0x800
 263 #define VXLAN_F_REMCSUM_NOPARTIAL       0x1000
 264 #define VXLAN_F_COLLECT_METADATA        0x2000
 265 #define VXLAN_F_GPE                     0x4000
 266 #define VXLAN_F_IPV6_LINKLOCAL          0x8000
 267 #define VXLAN_F_TTL_INHERIT             0x10000
 268
 269 /* Flags that are used in the receive path. These flags must match in
 270  * order for a socket to be shareable
 271  */
 272 #define VXLAN_F_RCV_FLAGS               (VXLAN_F_GBP |                  \
 273                                          VXLAN_F_GPE |                  \
 274                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 275                                          VXLAN_F_REMCSUM_RX |           \
 276                                          VXLAN_F_REMCSUM_NOPARTIAL |    \
 277                                          VXLAN_F_COLLECT_METADATA)
 278
 279 /* Flags that can be set together with VXLAN_F_GPE. */
 280 #define VXLAN_F_ALLOWED_GPE             (VXLAN_F_GPE |                  \
 281                                          VXLAN_F_IPV6 |                 \
 282                                          VXLAN_F_IPV6_LINKLOCAL |       \
 283                                          VXLAN_F_UDP_ZERO_CSUM_TX |     \
 284                                          VXLAN_F_UDP_ZERO_CSUM6_TX |    \
 285                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 286                                          VXLAN_F_COLLECT_METADATA)
 287
 288 struct net_device *vxlan_dev_create(struct net *net, const char *name,
 289                                     u8 name_assign_type, struct vxlan_config *conf);
 290
 291 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
 292                                                      netdev_features_t features)
 293 {
 294         u8 l4_hdr = 0;
 295
 296         if (!skb->encapsulation)
 297                 return features;
 298
 299         switch (vlan_get_protocol(skb)) {
 300         case htons(ETH_P_IP):
 301                 l4_hdr = ip_hdr(skb)->protocol;
 302                 break;
 303         case htons(ETH_P_IPV6):
 304                 l4_hdr = ipv6_hdr(skb)->nexthdr;
 305                 break;
 306         default:
 307                 return features;
 308         }
 309
 310         if ((l4_hdr == IPPROTO_UDP) &&
 311             (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
 312              skb->inner_protocol != htons(ETH_P_TEB) ||
 313              (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
 314               sizeof(struct udphdr) + sizeof(struct vxlanhdr)) ||
 315              (skb->ip_summed != CHECKSUM_NONE &&
 316               !can_checksum_protocol(features, inner_eth_hdr(skb)->h_proto))))
 317                 return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
 318
 319         return features;
 320 }
 321
 322 /* IP header + UDP + VXLAN + Ethernet header */
 323 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
 324 /* IPv6 header + UDP + VXLAN + Ethernet header */
 325 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
 326
 327 static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
 328 {
 329         return (struct vxlanhdr *)(udp_hdr(skb) + 1);
 330 }
 331
 332 static inline __be32 vxlan_vni(__be32 vni_field)
 333 {
 334 #if defined(__BIG_ENDIAN)
 335         return (__force __be32)((__force u32)vni_field >> 8);
 336 #else
 337         return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
 338 #endif
 339 }
 340
 341 static inline __be32 vxlan_vni_field(__be32 vni)
 342 {
 343 #if defined(__BIG_ENDIAN)
 344         return (__force __be32)((__force u32)vni << 8);
 345 #else
 346         return (__force __be32)((__force u32)vni >> 8);
 347 #endif
 348 }
 349
 350 static inline size_t vxlan_rco_start(__be32 vni_field)
 351 {
 352         return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
 353 }
 354
 355 static inline size_t vxlan_rco_offset(__be32 vni_field)
 356 {
 357         return (vni_field & VXLAN_RCO_UDP) ?
 358                 offsetof(struct udphdr, check) :
 359                 offsetof(struct tcphdr, check);
 360 }
 361
 362 static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
 363 {
 364         __be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
 365
 366         if (offset == offsetof(struct udphdr, check))
 367                 vni_field |= VXLAN_RCO_UDP;
 368         return vni_field;
 369 }
 370
 371 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
 372 {
 373         return vs->sock->sk->sk_family;
 374 }
 375
 376 #if IS_ENABLED(CONFIG_IPV6)
 377
 378 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
 379 {
 380         if (ipa->sa.sa_family == AF_INET6)
 381                 return ipv6_addr_any(&ipa->sin6.sin6_addr);
 382         else
 383                 return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
 384 }
 385
 386 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
 387 {
 388         if (ipa->sa.sa_family == AF_INET6)
 389                 return ipv6_addr_is_multicast(&ipa->sin6.sin6_addr);
 390         else
 391                 return IN_MULTICAST(ntohl(ipa->sin.sin_addr.s_addr));
 392 }
 393
 394 #else /* !IS_ENABLED(CONFIG_IPV6) */
 395
 396 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
 397 {
 398         return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
 399 }
 400
 401 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
 402 {
 403         return IN_MULTICAST(ntohl(ipa->sin.sin_addr.s_addr));
 404 }
 405
 406 #endif /* IS_ENABLED(CONFIG_IPV6) */
 407
 408 static inline bool netif_is_vxlan(const struct net_device *dev)
 409 {
 410         return dev->rtnl_link_ops &&
 411                !strcmp(dev->rtnl_link_ops->kind, "vxlan");
 412 }
 413
 414 struct switchdev_notifier_vxlan_fdb_info {
 415         struct switchdev_notifier_info info; /* must be first */
 416         union vxlan_addr remote_ip;
 417         __be16 remote_port;
 418         __be32 remote_vni;
 419         u32 remote_ifindex;
 420         u8 eth_addr[ETH_ALEN];
 421         __be32 vni;
 422         bool offloaded;
 423 };
 424
 425 #if IS_ENABLED(CONFIG_VXLAN)
 426 int vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 427                       struct switchdev_notifier_vxlan_fdb_info *fdb_info);
 428 #else
 429 static inline int
 430 vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 431                   struct switchdev_notifier_vxlan_fdb_info *fdb_info)
 432 {
 433         return -ENOENT;
 434 }
 435 #endif
 436
 437 #endif