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 #include <net/nexthop.h>
  11
  12 #define IANA_VXLAN_UDP_PORT     4789
  13
  14 /* VXLAN protocol (RFC 7348) header:
  15  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  16  * |R|R|R|R|I|R|R|R|               Reserved                        |
  17  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  18  * |                VXLAN Network Identifier (VNI) |   Reserved    |
  19  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  20  *
  21  * I = VXLAN Network Identifier (VNI) present.
  22  */
  23 struct vxlanhdr {
  24         __be32 vx_flags;
  25         __be32 vx_vni;
  26 };
  27
  28 /* VXLAN header flags. */
  29 #define VXLAN_HF_VNI    cpu_to_be32(BIT(27))
  30
  31 #define VXLAN_N_VID     (1u << 24)
  32 #define VXLAN_VID_MASK  (VXLAN_N_VID - 1)
  33 #define VXLAN_VNI_MASK  cpu_to_be32(VXLAN_VID_MASK << 8)
  34 #define VXLAN_HLEN (sizeof(struct udphdr) + sizeof(struct vxlanhdr))
  35
  36 #define VNI_HASH_BITS   10
  37 #define VNI_HASH_SIZE   (1<<VNI_HASH_BITS)
  38 #define FDB_HASH_BITS   8
  39 #define FDB_HASH_SIZE   (1<<FDB_HASH_BITS)
  40
  41 /* Remote checksum offload for VXLAN (VXLAN_F_REMCSUM_[RT]X):
  42  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  43  * |R|R|R|R|I|R|R|R|R|R|C|              Reserved                   |
  44  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  45  * |           VXLAN Network Identifier (VNI)      |O| Csum start  |
  46  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  47  *
  48  * C = Remote checksum offload bit. When set indicates that the
  49  *     remote checksum offload data is present.
  50  *
  51  * O = Offset bit. Indicates the checksum offset relative to
  52  *     checksum start.
  53  *
  54  * Csum start = Checksum start divided by two.
  55  *
  56  * http://tools.ietf.org/html/draft-herbert-vxlan-rco
  57  */
  58
  59 /* VXLAN-RCO header flags. */
  60 #define VXLAN_HF_RCO    cpu_to_be32(BIT(21))
  61
  62 /* Remote checksum offload header option */
  63 #define VXLAN_RCO_MASK  cpu_to_be32(0x7f)  /* Last byte of vni field */
  64 #define VXLAN_RCO_UDP   cpu_to_be32(0x80)  /* Indicate UDP RCO (TCP when not set *) */
  65 #define VXLAN_RCO_SHIFT 1                  /* Left shift of start */
  66 #define VXLAN_RCO_SHIFT_MASK ((1 << VXLAN_RCO_SHIFT) - 1)
  67 #define VXLAN_MAX_REMCSUM_START (0x7f << VXLAN_RCO_SHIFT)
  68
  69 /*
  70  * VXLAN Group Based Policy Extension (VXLAN_F_GBP):
  71  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  72  * |G|R|R|R|I|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
  73  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  74  * |                VXLAN Network Identifier (VNI) |   Reserved    |
  75  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  76  *
  77  * G = Group Policy ID present.
  78  *
  79  * D = Don't Learn bit. When set, this bit indicates that the egress
  80  *     VTEP MUST NOT learn the source address of the encapsulated frame.
  81  *
  82  * A = Indicates that the group policy has already been applied to
  83  *     this packet. Policies MUST NOT be applied by devices when the
  84  *     A bit is set.
  85  *
  86  * https://tools.ietf.org/html/draft-smith-vxlan-group-policy
  87  */
  88 struct vxlanhdr_gbp {
  89         u8      vx_flags;
  90 #ifdef __LITTLE_ENDIAN_BITFIELD
  91         u8      reserved_flags1:3,
  92                 policy_applied:1,
  93                 reserved_flags2:2,
  94                 dont_learn:1,
  95                 reserved_flags3:1;
  96 #elif defined(__BIG_ENDIAN_BITFIELD)
  97         u8      reserved_flags1:1,
  98                 dont_learn:1,
  99                 reserved_flags2:2,
 100                 policy_applied:1,
 101                 reserved_flags3:3;
 102 #else
 103 #error  "Please fix <asm/byteorder.h>"
 104 #endif
 105         __be16  policy_id;
 106         __be32  vx_vni;
 107 };
 108
 109 /* VXLAN-GBP header flags. */
 110 #define VXLAN_HF_GBP    cpu_to_be32(BIT(31))
 111
 112 #define VXLAN_GBP_USED_BITS (VXLAN_HF_GBP | cpu_to_be32(0xFFFFFF))
 113
 114 /* skb->mark mapping
 115  *
 116  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 117  * |R|R|R|R|R|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
 118  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 119  */
 120 #define VXLAN_GBP_DONT_LEARN            (BIT(6) << 16)
 121 #define VXLAN_GBP_POLICY_APPLIED        (BIT(3) << 16)
 122 #define VXLAN_GBP_ID_MASK               (0xFFFF)
 123
 124 /*
 125  * VXLAN Generic Protocol Extension (VXLAN_F_GPE):
 126  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 127  * |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
 128  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 129  * |                VXLAN Network Identifier (VNI) |   Reserved    |
 130  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 131  *
 132  * Ver = Version. Indicates VXLAN GPE protocol version.
 133  *
 134  * P = Next Protocol Bit. The P bit is set to indicate that the
 135  *     Next Protocol field is present.
 136  *
 137  * O = OAM Flag Bit. The O bit is set to indicate that the packet
 138  *     is an OAM packet.
 139  *
 140  * Next Protocol = This 8 bit field indicates the protocol header
 141  * immediately following the VXLAN GPE header.
 142  *
 143  * https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-01
 144  */
 145
 146 struct vxlanhdr_gpe {
 147 #if defined(__LITTLE_ENDIAN_BITFIELD)
 148         u8      oam_flag:1,
 149                 reserved_flags1:1,
 150                 np_applied:1,
 151                 instance_applied:1,
 152                 version:2,
 153                 reserved_flags2:2;
 154 #elif defined(__BIG_ENDIAN_BITFIELD)
 155         u8      reserved_flags2:2,
 156                 version:2,
 157                 instance_applied:1,
 158                 np_applied:1,
 159                 reserved_flags1:1,
 160                 oam_flag:1;
 161 #endif
 162         u8      reserved_flags3;
 163         u8      reserved_flags4;
 164         u8      next_protocol;
 165         __be32  vx_vni;
 166 };
 167
 168 /* VXLAN-GPE header flags. */
 169 #define VXLAN_HF_VER    cpu_to_be32(BIT(29) | BIT(28))
 170 #define VXLAN_HF_NP     cpu_to_be32(BIT(26))
 171 #define VXLAN_HF_OAM    cpu_to_be32(BIT(24))
 172
 173 #define VXLAN_GPE_USED_BITS (VXLAN_HF_VER | VXLAN_HF_NP | VXLAN_HF_OAM | \
 174                              cpu_to_be32(0xff))
 175
 176 struct vxlan_metadata {
 177         u32             gbp;
 178 };
 179
 180 /* per UDP socket information */
 181 struct vxlan_sock {
 182         struct hlist_node hlist;
 183         struct socket    *sock;
 184         struct hlist_head vni_list[VNI_HASH_SIZE];
 185         refcount_t        refcnt;
 186         u32               flags;
 187 };
 188
 189 union vxlan_addr {
 190         struct sockaddr_in sin;
 191         struct sockaddr_in6 sin6;
 192         struct sockaddr sa;
 193 };
 194
 195 struct vxlan_rdst {
 196         union vxlan_addr         remote_ip;
 197         __be16                   remote_port;
 198         u8                       offloaded:1;
 199         __be32                   remote_vni;
 200         u32                      remote_ifindex;
 201         struct net_device        *remote_dev;
 202         struct list_head         list;
 203         struct rcu_head          rcu;
 204         struct dst_cache         dst_cache;
 205 };
 206
 207 struct vxlan_config {
 208         union vxlan_addr        remote_ip;
 209         union vxlan_addr        saddr;
 210         __be32                  vni;
 211         int                     remote_ifindex;
 212         int                     mtu;
 213         __be16                  dst_port;
 214         u16                     port_min;
 215         u16                     port_max;
 216         u8                      tos;
 217         u8                      ttl;
 218         __be32                  label;
 219         u32                     flags;
 220         unsigned long           age_interval;
 221         unsigned int            addrmax;
 222         bool                    no_share;
 223         enum ifla_vxlan_df      df;
 224 };
 225
 226 struct vxlan_dev_node {
 227         struct hlist_node hlist;
 228         struct vxlan_dev *vxlan;
 229 };
 230
 231 /* Pseudo network device */
 232 struct vxlan_dev {
 233         struct vxlan_dev_node hlist4;   /* vni hash table for IPv4 socket */
 234 #if IS_ENABLED(CONFIG_IPV6)
 235         struct vxlan_dev_node hlist6;   /* vni hash table for IPv6 socket */
 236 #endif
 237         struct list_head  next;         /* vxlan's per namespace list */
 238         struct vxlan_sock __rcu *vn4_sock;      /* listening socket for IPv4 */
 239 #if IS_ENABLED(CONFIG_IPV6)
 240         struct vxlan_sock __rcu *vn6_sock;      /* listening socket for IPv6 */
 241 #endif
 242         struct net_device *dev;
 243         struct net        *net;         /* netns for packet i/o */
 244         struct vxlan_rdst default_dst;  /* default destination */
 245
 246         struct timer_list age_timer;
 247         spinlock_t        hash_lock[FDB_HASH_SIZE];
 248         unsigned int      addrcnt;
 249         struct gro_cells  gro_cells;
 250
 251         struct vxlan_config     cfg;
 252
 253         struct hlist_head fdb_head[FDB_HASH_SIZE];
 254 };
 255
 256 #define VXLAN_F_LEARN                   0x01
 257 #define VXLAN_F_PROXY                   0x02
 258 #define VXLAN_F_RSC                     0x04
 259 #define VXLAN_F_L2MISS                  0x08
 260 #define VXLAN_F_L3MISS                  0x10
 261 #define VXLAN_F_IPV6                    0x20
 262 #define VXLAN_F_UDP_ZERO_CSUM_TX        0x40
 263 #define VXLAN_F_UDP_ZERO_CSUM6_TX       0x80
 264 #define VXLAN_F_UDP_ZERO_CSUM6_RX       0x100
 265 #define VXLAN_F_REMCSUM_TX              0x200
 266 #define VXLAN_F_REMCSUM_RX              0x400
 267 #define VXLAN_F_GBP                     0x800
 268 #define VXLAN_F_REMCSUM_NOPARTIAL       0x1000
 269 #define VXLAN_F_COLLECT_METADATA        0x2000
 270 #define VXLAN_F_GPE                     0x4000
 271 #define VXLAN_F_IPV6_LINKLOCAL          0x8000
 272 #define VXLAN_F_TTL_INHERIT             0x10000
 273
 274 /* Flags that are used in the receive path. These flags must match in
 275  * order for a socket to be shareable
 276  */
 277 #define VXLAN_F_RCV_FLAGS               (VXLAN_F_GBP |                  \
 278                                          VXLAN_F_GPE |                  \
 279                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 280                                          VXLAN_F_REMCSUM_RX |           \
 281                                          VXLAN_F_REMCSUM_NOPARTIAL |    \
 282                                          VXLAN_F_COLLECT_METADATA)
 283
 284 /* Flags that can be set together with VXLAN_F_GPE. */
 285 #define VXLAN_F_ALLOWED_GPE             (VXLAN_F_GPE |                  \
 286                                          VXLAN_F_IPV6 |                 \
 287                                          VXLAN_F_IPV6_LINKLOCAL |       \
 288                                          VXLAN_F_UDP_ZERO_CSUM_TX |     \
 289                                          VXLAN_F_UDP_ZERO_CSUM6_TX |    \
 290                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 291                                          VXLAN_F_COLLECT_METADATA)
 292
 293 struct net_device *vxlan_dev_create(struct net *net, const char *name,
 294                                     u8 name_assign_type, struct vxlan_config *conf);
 295
 296 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
 297                                                      netdev_features_t features)
 298 {
 299         u8 l4_hdr = 0;
 300
 301         if (!skb->encapsulation)
 302                 return features;
 303
 304         switch (vlan_get_protocol(skb)) {
 305         case htons(ETH_P_IP):
 306                 l4_hdr = ip_hdr(skb)->protocol;
 307                 break;
 308         case htons(ETH_P_IPV6):
 309                 l4_hdr = ipv6_hdr(skb)->nexthdr;
 310                 break;
 311         default:
 312                 return features;
 313         }
 314
 315         if ((l4_hdr == IPPROTO_UDP) &&
 316             (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
 317              skb->inner_protocol != htons(ETH_P_TEB) ||
 318              (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
 319               sizeof(struct udphdr) + sizeof(struct vxlanhdr)) ||
 320              (skb->ip_summed != CHECKSUM_NONE &&
 321               !can_checksum_protocol(features, inner_eth_hdr(skb)->h_proto))))
 322                 return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
 323
 324         return features;
 325 }
 326
 327 /* IP header + UDP + VXLAN + Ethernet header */
 328 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
 329 /* IPv6 header + UDP + VXLAN + Ethernet header */
 330 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
 331
 332 static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
 333 {
 334         return (struct vxlanhdr *)(udp_hdr(skb) + 1);
 335 }
 336
 337 static inline __be32 vxlan_vni(__be32 vni_field)
 338 {
 339 #if defined(__BIG_ENDIAN)
 340         return (__force __be32)((__force u32)vni_field >> 8);
 341 #else
 342         return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
 343 #endif
 344 }
 345
 346 static inline __be32 vxlan_vni_field(__be32 vni)
 347 {
 348 #if defined(__BIG_ENDIAN)
 349         return (__force __be32)((__force u32)vni << 8);
 350 #else
 351         return (__force __be32)((__force u32)vni >> 8);
 352 #endif
 353 }
 354
 355 static inline size_t vxlan_rco_start(__be32 vni_field)
 356 {
 357         return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
 358 }
 359
 360 static inline size_t vxlan_rco_offset(__be32 vni_field)
 361 {
 362         return (vni_field & VXLAN_RCO_UDP) ?
 363                 offsetof(struct udphdr, check) :
 364                 offsetof(struct tcphdr, check);
 365 }
 366
 367 static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
 368 {
 369         __be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
 370
 371         if (offset == offsetof(struct udphdr, check))
 372                 vni_field |= VXLAN_RCO_UDP;
 373         return vni_field;
 374 }
 375
 376 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
 377 {
 378         return vs->sock->sk->sk_family;
 379 }
 380
 381 #if IS_ENABLED(CONFIG_IPV6)
 382
 383 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
 384 {
 385         if (ipa->sa.sa_family == AF_INET6)
 386                 return ipv6_addr_any(&ipa->sin6.sin6_addr);
 387         else
 388                 return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
 389 }
 390
 391 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
 392 {
 393         if (ipa->sa.sa_family == AF_INET6)
 394                 return ipv6_addr_is_multicast(&ipa->sin6.sin6_addr);
 395         else
 396                 return ipv4_is_multicast(ipa->sin.sin_addr.s_addr);
 397 }
 398
 399 #else /* !IS_ENABLED(CONFIG_IPV6) */
 400
 401 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
 402 {
 403         return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
 404 }
 405
 406 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
 407 {
 408         return ipv4_is_multicast(ipa->sin.sin_addr.s_addr);
 409 }
 410
 411 #endif /* IS_ENABLED(CONFIG_IPV6) */
 412
 413 static inline bool netif_is_vxlan(const struct net_device *dev)
 414 {
 415         return dev->rtnl_link_ops &&
 416                !strcmp(dev->rtnl_link_ops->kind, "vxlan");
 417 }
 418
 419 struct switchdev_notifier_vxlan_fdb_info {
 420         struct switchdev_notifier_info info; /* must be first */
 421         union vxlan_addr remote_ip;
 422         __be16 remote_port;
 423         __be32 remote_vni;
 424         u32 remote_ifindex;
 425         u8 eth_addr[ETH_ALEN];
 426         __be32 vni;
 427         bool offloaded;
 428         bool added_by_user;
 429 };
 430
 431 #if IS_ENABLED(CONFIG_VXLAN)
 432 int vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 433                       struct switchdev_notifier_vxlan_fdb_info *fdb_info);
 434 int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
 435                      struct notifier_block *nb,
 436                      struct netlink_ext_ack *extack);
 437 void vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni);
 438
 439 #else
 440 static inline int
 441 vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 442                   struct switchdev_notifier_vxlan_fdb_info *fdb_info)
 443 {
 444         return -ENOENT;
 445 }
 446
 447 static inline int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
 448                                    struct notifier_block *nb,
 449                                    struct netlink_ext_ack *extack)
 450 {
 451         return -EOPNOTSUPP;
 452 }
 453
 454 static inline void
 455 vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni)
 456 {
 457 }
 458 #endif
 459
 460 static inline void vxlan_flag_attr_error(int attrtype,
 461                                          struct netlink_ext_ack *extack)
 462 {
 463 #define VXLAN_FLAG(flg) \
 464         case IFLA_VXLAN_##flg: \
 465                 NL_SET_ERR_MSG_MOD(extack, \
 466                                    "cannot change " #flg " flag"); \
 467                 break
 468         switch (attrtype) {
 469         VXLAN_FLAG(TTL_INHERIT);
 470         VXLAN_FLAG(LEARNING);
 471         VXLAN_FLAG(PROXY);
 472         VXLAN_FLAG(RSC);
 473         VXLAN_FLAG(L2MISS);
 474         VXLAN_FLAG(L3MISS);
 475         VXLAN_FLAG(COLLECT_METADATA);
 476         VXLAN_FLAG(UDP_ZERO_CSUM6_TX);
 477         VXLAN_FLAG(UDP_ZERO_CSUM6_RX);
 478         VXLAN_FLAG(REMCSUM_TX);
 479         VXLAN_FLAG(REMCSUM_RX);
 480         VXLAN_FLAG(GBP);
 481         VXLAN_FLAG(GPE);
 482         VXLAN_FLAG(REMCSUM_NOPARTIAL);
 483         default:
 484                 NL_SET_ERR_MSG_MOD(extack, \
 485                                    "cannot change flag");
 486                 break;
 487         }
 488 #undef VXLAN_FLAG
 489 }
 490
 491 static inline bool vxlan_fdb_nh_path_select(struct nexthop *nh,
 492                                             int hash,
 493                                             struct vxlan_rdst *rdst)
 494 {
 495         struct fib_nh_common *nhc;
 496
 497         nhc = nexthop_path_fdb_result(nh, hash);
 498         if (unlikely(!nhc))
 499                 return false;
 500
 501         switch (nhc->nhc_gw_family) {
 502         case AF_INET:
 503                 rdst->remote_ip.sin.sin_addr.s_addr = nhc->nhc_gw.ipv4;
 504                 rdst->remote_ip.sa.sa_family = AF_INET;
 505                 break;
 506         case AF_INET6:
 507                 rdst->remote_ip.sin6.sin6_addr = nhc->nhc_gw.ipv6;
 508                 rdst->remote_ip.sa.sa_family = AF_INET6;
 509                 break;
 510         }
 511
 512         return true;
 513 }
 514
 515 #endif