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         enum ifla_vxlan_df      df;
 220 };
 221
 222 struct vxlan_dev_node {
 223         struct hlist_node hlist;
 224         struct vxlan_dev *vxlan;
 225 };
 226
 227 /* Pseudo network device */
 228 struct vxlan_dev {
 229         struct vxlan_dev_node hlist4;   /* vni hash table for IPv4 socket */
 230 #if IS_ENABLED(CONFIG_IPV6)
 231         struct vxlan_dev_node hlist6;   /* vni hash table for IPv6 socket */
 232 #endif
 233         struct list_head  next;         /* vxlan's per namespace list */
 234         struct vxlan_sock __rcu *vn4_sock;      /* listening socket for IPv4 */
 235 #if IS_ENABLED(CONFIG_IPV6)
 236         struct vxlan_sock __rcu *vn6_sock;      /* listening socket for IPv6 */
 237 #endif
 238         struct net_device *dev;
 239         struct net        *net;         /* netns for packet i/o */
 240         struct vxlan_rdst default_dst;  /* default destination */
 241
 242         struct timer_list age_timer;
 243         spinlock_t        hash_lock;
 244         unsigned int      addrcnt;
 245         struct gro_cells  gro_cells;
 246
 247         struct vxlan_config     cfg;
 248
 249         struct hlist_head fdb_head[FDB_HASH_SIZE];
 250 };
 251
 252 #define VXLAN_F_LEARN                   0x01
 253 #define VXLAN_F_PROXY                   0x02
 254 #define VXLAN_F_RSC                     0x04
 255 #define VXLAN_F_L2MISS                  0x08
 256 #define VXLAN_F_L3MISS                  0x10
 257 #define VXLAN_F_IPV6                    0x20
 258 #define VXLAN_F_UDP_ZERO_CSUM_TX        0x40
 259 #define VXLAN_F_UDP_ZERO_CSUM6_TX       0x80
 260 #define VXLAN_F_UDP_ZERO_CSUM6_RX       0x100
 261 #define VXLAN_F_REMCSUM_TX              0x200
 262 #define VXLAN_F_REMCSUM_RX              0x400
 263 #define VXLAN_F_GBP                     0x800
 264 #define VXLAN_F_REMCSUM_NOPARTIAL       0x1000
 265 #define VXLAN_F_COLLECT_METADATA        0x2000
 266 #define VXLAN_F_GPE                     0x4000
 267 #define VXLAN_F_IPV6_LINKLOCAL          0x8000
 268 #define VXLAN_F_TTL_INHERIT             0x10000
 269
 270 /* Flags that are used in the receive path. These flags must match in
 271  * order for a socket to be shareable
 272  */
 273 #define VXLAN_F_RCV_FLAGS               (VXLAN_F_GBP |                  \
 274                                          VXLAN_F_GPE |                  \
 275                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 276                                          VXLAN_F_REMCSUM_RX |           \
 277                                          VXLAN_F_REMCSUM_NOPARTIAL |    \
 278                                          VXLAN_F_COLLECT_METADATA)
 279
 280 /* Flags that can be set together with VXLAN_F_GPE. */
 281 #define VXLAN_F_ALLOWED_GPE             (VXLAN_F_GPE |                  \
 282                                          VXLAN_F_IPV6 |                 \
 283                                          VXLAN_F_IPV6_LINKLOCAL |       \
 284                                          VXLAN_F_UDP_ZERO_CSUM_TX |     \
 285                                          VXLAN_F_UDP_ZERO_CSUM6_TX |    \
 286                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 287                                          VXLAN_F_COLLECT_METADATA)
 288
 289 struct net_device *vxlan_dev_create(struct net *net, const char *name,
 290                                     u8 name_assign_type, struct vxlan_config *conf);
 291
 292 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
 293                                                      netdev_features_t features)
 294 {
 295         u8 l4_hdr = 0;
 296
 297         if (!skb->encapsulation)
 298                 return features;
 299
 300         switch (vlan_get_protocol(skb)) {
 301         case htons(ETH_P_IP):
 302                 l4_hdr = ip_hdr(skb)->protocol;
 303                 break;
 304         case htons(ETH_P_IPV6):
 305                 l4_hdr = ipv6_hdr(skb)->nexthdr;
 306                 break;
 307         default:
 308                 return features;
 309         }
 310
 311         if ((l4_hdr == IPPROTO_UDP) &&
 312             (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
 313              skb->inner_protocol != htons(ETH_P_TEB) ||
 314              (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
 315               sizeof(struct udphdr) + sizeof(struct vxlanhdr)) ||
 316              (skb->ip_summed != CHECKSUM_NONE &&
 317               !can_checksum_protocol(features, inner_eth_hdr(skb)->h_proto))))
 318                 return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
 319
 320         return features;
 321 }
 322
 323 /* IP header + UDP + VXLAN + Ethernet header */
 324 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
 325 /* IPv6 header + UDP + VXLAN + Ethernet header */
 326 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
 327
 328 static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
 329 {
 330         return (struct vxlanhdr *)(udp_hdr(skb) + 1);
 331 }
 332
 333 static inline __be32 vxlan_vni(__be32 vni_field)
 334 {
 335 #if defined(__BIG_ENDIAN)
 336         return (__force __be32)((__force u32)vni_field >> 8);
 337 #else
 338         return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
 339 #endif
 340 }
 341
 342 static inline __be32 vxlan_vni_field(__be32 vni)
 343 {
 344 #if defined(__BIG_ENDIAN)
 345         return (__force __be32)((__force u32)vni << 8);
 346 #else
 347         return (__force __be32)((__force u32)vni >> 8);
 348 #endif
 349 }
 350
 351 static inline size_t vxlan_rco_start(__be32 vni_field)
 352 {
 353         return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
 354 }
 355
 356 static inline size_t vxlan_rco_offset(__be32 vni_field)
 357 {
 358         return (vni_field & VXLAN_RCO_UDP) ?
 359                 offsetof(struct udphdr, check) :
 360                 offsetof(struct tcphdr, check);
 361 }
 362
 363 static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
 364 {
 365         __be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
 366
 367         if (offset == offsetof(struct udphdr, check))
 368                 vni_field |= VXLAN_RCO_UDP;
 369         return vni_field;
 370 }
 371
 372 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
 373 {
 374         return vs->sock->sk->sk_family;
 375 }
 376
 377 #if IS_ENABLED(CONFIG_IPV6)
 378
 379 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
 380 {
 381         if (ipa->sa.sa_family == AF_INET6)
 382                 return ipv6_addr_any(&ipa->sin6.sin6_addr);
 383         else
 384                 return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
 385 }
 386
 387 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
 388 {
 389         if (ipa->sa.sa_family == AF_INET6)
 390                 return ipv6_addr_is_multicast(&ipa->sin6.sin6_addr);
 391         else
 392                 return IN_MULTICAST(ntohl(ipa->sin.sin_addr.s_addr));
 393 }
 394
 395 #else /* !IS_ENABLED(CONFIG_IPV6) */
 396
 397 static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
 398 {
 399         return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
 400 }
 401
 402 static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
 403 {
 404         return IN_MULTICAST(ntohl(ipa->sin.sin_addr.s_addr));
 405 }
 406
 407 #endif /* IS_ENABLED(CONFIG_IPV6) */
 408
 409 static inline bool netif_is_vxlan(const struct net_device *dev)
 410 {
 411         return dev->rtnl_link_ops &&
 412                !strcmp(dev->rtnl_link_ops->kind, "vxlan");
 413 }
 414
 415 struct switchdev_notifier_vxlan_fdb_info {
 416         struct switchdev_notifier_info info; /* must be first */
 417         union vxlan_addr remote_ip;
 418         __be16 remote_port;
 419         __be32 remote_vni;
 420         u32 remote_ifindex;
 421         u8 eth_addr[ETH_ALEN];
 422         __be32 vni;
 423         bool offloaded;
 424         bool added_by_user;
 425 };
 426
 427 #if IS_ENABLED(CONFIG_VXLAN)
 428 int vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 429                       struct switchdev_notifier_vxlan_fdb_info *fdb_info);
 430 int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
 431                      struct notifier_block *nb,
 432                      struct netlink_ext_ack *extack);
 433 void vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni);
 434
 435 #else
 436 static inline int
 437 vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 438                   struct switchdev_notifier_vxlan_fdb_info *fdb_info)
 439 {
 440         return -ENOENT;
 441 }
 442
 443 static inline int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
 444                                    struct notifier_block *nb,
 445                                    struct netlink_ext_ack *extack)
 446 {
 447         return -EOPNOTSUPP;
 448 }
 449
 450 static inline void
 451 vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni)
 452 {
 453 }
 454 #endif
 455
 456 static inline void vxlan_flag_attr_error(int attrtype,
 457                                          struct netlink_ext_ack *extack)
 458 {
 459 #define VXLAN_FLAG(flg) \
 460         case IFLA_VXLAN_##flg: \
 461                 NL_SET_ERR_MSG_MOD(extack, \
 462                                    "cannot change " #flg " flag"); \
 463                 break
 464         switch (attrtype) {
 465         VXLAN_FLAG(TTL_INHERIT);
 466         VXLAN_FLAG(LEARNING);
 467         VXLAN_FLAG(PROXY);
 468         VXLAN_FLAG(RSC);
 469         VXLAN_FLAG(L2MISS);
 470         VXLAN_FLAG(L3MISS);
 471         VXLAN_FLAG(COLLECT_METADATA);
 472         VXLAN_FLAG(UDP_ZERO_CSUM6_TX);
 473         VXLAN_FLAG(UDP_ZERO_CSUM6_RX);
 474         VXLAN_FLAG(REMCSUM_TX);
 475         VXLAN_FLAG(REMCSUM_RX);
 476         VXLAN_FLAG(GBP);
 477         VXLAN_FLAG(GPE);
 478         VXLAN_FLAG(REMCSUM_NOPARTIAL);
 479         default:
 480                 NL_SET_ERR_MSG_MOD(extack, \
 481                                    "cannot change flag");
 482                 break;
 483         }
 484 #undef VXLAN_FLAG
 485 }
 486
 487 #endif