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