LXR linux/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 */
  23struct 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 */
  88struct 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#define VXLAN_GBP_MASK (VXLAN_GBP_DONT_LEARN | VXLAN_GBP_POLICY_APPLIED | \
 125                        VXLAN_GBP_ID_MASK)
 126
 127/*
 128 * VXLAN Generic Protocol Extension (VXLAN_F_GPE):
 129 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 130 * |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
 131 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 132 * |                VXLAN Network Identifier (VNI) |   Reserved    |
 133 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 134 *
 135 * Ver = Version. Indicates VXLAN GPE protocol version.
 136 *
 137 * P = Next Protocol Bit. The P bit is set to indicate that the
 138 *     Next Protocol field is present.
 139 *
 140 * O = OAM Flag Bit. The O bit is set to indicate that the packet
 141 *     is an OAM packet.
 142 *
 143 * Next Protocol = This 8 bit field indicates the protocol header
 144 * immediately following the VXLAN GPE header.
 145 *
 146 * https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-01
 147 */
 148
 149struct vxlanhdr_gpe {
 150#if defined(__LITTLE_ENDIAN_BITFIELD)
 151        u8      oam_flag:1,
 152                reserved_flags1:1,
 153                np_applied:1,
 154                instance_applied:1,
 155                version:2,
 156                reserved_flags2:2;
 157#elif defined(__BIG_ENDIAN_BITFIELD)
 158        u8      reserved_flags2:2,
 159                version:2,
 160                instance_applied:1,
 161                np_applied:1,
 162                reserved_flags1:1,
 163                oam_flag:1;
 164#endif
 165        u8      reserved_flags3;
 166        u8      reserved_flags4;
 167        u8      next_protocol;
 168        __be32  vx_vni;
 169};
 170
 171/* VXLAN-GPE header flags. */
 172#define VXLAN_HF_VER    cpu_to_be32(BIT(29) | BIT(28))
 173#define VXLAN_HF_NP     cpu_to_be32(BIT(26))
 174#define VXLAN_HF_OAM    cpu_to_be32(BIT(24))
 175
 176#define VXLAN_GPE_USED_BITS (VXLAN_HF_VER | VXLAN_HF_NP | VXLAN_HF_OAM | \
 177                             cpu_to_be32(0xff))
 178
 179struct vxlan_metadata {
 180        u32             gbp;
 181};
 182
 183/* per UDP socket information */
 184struct vxlan_sock {
 185        struct hlist_node hlist;
 186        struct socket    *sock;
 187        struct hlist_head vni_list[VNI_HASH_SIZE];
 188        refcount_t        refcnt;
 189        u32               flags;
 190};
 191
 192union vxlan_addr {
 193        struct sockaddr_in sin;
 194        struct sockaddr_in6 sin6;
 195        struct sockaddr sa;
 196};
 197
 198struct vxlan_rdst {
 199        union vxlan_addr         remote_ip;
 200        __be16                   remote_port;
 201        u8                       offloaded:1;
 202        __be32                   remote_vni;
 203        u32                      remote_ifindex;
 204        struct net_device        *remote_dev;
 205        struct list_head         list;
 206        struct rcu_head          rcu;
 207        struct dst_cache         dst_cache;
 208};
 209
 210struct vxlan_config {
 211        union vxlan_addr        remote_ip;
 212        union vxlan_addr        saddr;
 213        __be32                  vni;
 214        int                     remote_ifindex;
 215        int                     mtu;
 216        __be16                  dst_port;
 217        u16                     port_min;
 218        u16                     port_max;
 219        u8                      tos;
 220        u8                      ttl;
 221        __be32                  label;
 222        u32                     flags;
 223        unsigned long           age_interval;
 224        unsigned int            addrmax;
 225        bool                    no_share;
 226        enum ifla_vxlan_df      df;
 227};
 228
 229struct vxlan_dev_node {
 230        struct hlist_node hlist;
 231        struct vxlan_dev *vxlan;
 232};
 233
 234/* Pseudo network device */
 235struct vxlan_dev {
 236        struct vxlan_dev_node hlist4;   /* vni hash table for IPv4 socket */
 237#if IS_ENABLED(CONFIG_IPV6)
 238        struct vxlan_dev_node hlist6;   /* vni hash table for IPv6 socket */
 239#endif
 240        struct list_head  next;         /* vxlan's per namespace list */
 241        struct vxlan_sock __rcu *vn4_sock;      /* listening socket for IPv4 */
 242#if IS_ENABLED(CONFIG_IPV6)
 243        struct vxlan_sock __rcu *vn6_sock;      /* listening socket for IPv6 */
 244#endif
 245        struct net_device *dev;
 246        struct net        *net;         /* netns for packet i/o */
 247        struct vxlan_rdst default_dst;  /* default destination */
 248
 249        struct timer_list age_timer;
 250        spinlock_t        hash_lock[FDB_HASH_SIZE];
 251        unsigned int      addrcnt;
 252        struct gro_cells  gro_cells;
 253
 254        struct vxlan_config     cfg;
 255
 256        struct hlist_head fdb_head[FDB_HASH_SIZE];
 257};
 258
 259#define VXLAN_F_LEARN                   0x01
 260#define VXLAN_F_PROXY                   0x02
 261#define VXLAN_F_RSC                     0x04
 262#define VXLAN_F_L2MISS                  0x08
 263#define VXLAN_F_L3MISS                  0x10
 264#define VXLAN_F_IPV6                    0x20
 265#define VXLAN_F_UDP_ZERO_CSUM_TX        0x40
 266#define VXLAN_F_UDP_ZERO_CSUM6_TX       0x80
 267#define VXLAN_F_UDP_ZERO_CSUM6_RX       0x100
 268#define VXLAN_F_REMCSUM_TX              0x200
 269#define VXLAN_F_REMCSUM_RX              0x400
 270#define VXLAN_F_GBP                     0x800
 271#define VXLAN_F_REMCSUM_NOPARTIAL       0x1000
 272#define VXLAN_F_COLLECT_METADATA        0x2000
 273#define VXLAN_F_GPE                     0x4000
 274#define VXLAN_F_IPV6_LINKLOCAL          0x8000
 275#define VXLAN_F_TTL_INHERIT             0x10000
 276
 277/* Flags that are used in the receive path. These flags must match in
 278 * order for a socket to be shareable
 279 */
 280#define VXLAN_F_RCV_FLAGS               (VXLAN_F_GBP |                  \
 281                                         VXLAN_F_GPE |                  \
 282                                         VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 283                                         VXLAN_F_REMCSUM_RX |           \
 284                                         VXLAN_F_REMCSUM_NOPARTIAL |    \
 285                                         VXLAN_F_COLLECT_METADATA)
 286
 287/* Flags that can be set together with VXLAN_F_GPE. */
 288#define VXLAN_F_ALLOWED_GPE             (VXLAN_F_GPE |                  \
 289                                         VXLAN_F_IPV6 |                 \
 290                                         VXLAN_F_IPV6_LINKLOCAL |       \
 291                                         VXLAN_F_UDP_ZERO_CSUM_TX |     \
 292                                         VXLAN_F_UDP_ZERO_CSUM6_TX |    \
 293                                         VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 294                                         VXLAN_F_COLLECT_METADATA)
 295
 296struct net_device *vxlan_dev_create(struct net *net, const char *name,
 297                                    u8 name_assign_type, struct vxlan_config *conf);
 298
 299static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
 300                                                     netdev_features_t features)
 301{
 302        u8 l4_hdr = 0;
 303
 304        if (!skb->encapsulation)
 305                return features;
 306
 307        switch (vlan_get_protocol(skb)) {
 308        case htons(ETH_P_IP):
 309                l4_hdr = ip_hdr(skb)->protocol;
 310                break;
 311        case htons(ETH_P_IPV6):
 312                l4_hdr = ipv6_hdr(skb)->nexthdr;
 313                break;
 314        default:
 315                return features;
 316        }
 317
 318        if ((l4_hdr == IPPROTO_UDP) &&
 319            (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
 320             skb->inner_protocol != htons(ETH_P_TEB) ||
 321             (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
 322              sizeof(struct udphdr) + sizeof(struct vxlanhdr)) ||
 323             (skb->ip_summed != CHECKSUM_NONE &&
 324              !can_checksum_protocol(features, inner_eth_hdr(skb)->h_proto))))
 325                return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
 326
 327        return features;
 328}
 329
 330/* IP header + UDP + VXLAN + Ethernet header */
 331#define VXLAN_HEADROOM (20 + 8 + 8 + 14)
 332/* IPv6 header + UDP + VXLAN + Ethernet header */
 333#define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
 334
 335static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
 336{
 337        return (struct vxlanhdr *)(udp_hdr(skb) + 1);
 338}
 339
 340static inline __be32 vxlan_vni(__be32 vni_field)
 341{
 342#if defined(__BIG_ENDIAN)
 343        return (__force __be32)((__force u32)vni_field >> 8);
 344#else
 345        return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
 346#endif
 347}
 348
 349static inline __be32 vxlan_vni_field(__be32 vni)
 350{
 351#if defined(__BIG_ENDIAN)
 352        return (__force __be32)((__force u32)vni << 8);
 353#else
 354        return (__force __be32)((__force u32)vni >> 8);
 355#endif
 356}
 357
 358static inline size_t vxlan_rco_start(__be32 vni_field)
 359{
 360        return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
 361}
 362
 363static inline size_t vxlan_rco_offset(__be32 vni_field)
 364{
 365        return (vni_field & VXLAN_RCO_UDP) ?
 366                offsetof(struct udphdr, check) :
 367                offsetof(struct tcphdr, check);
 368}
 369
 370static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
 371{
 372        __be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
 373
 374        if (offset == offsetof(struct udphdr, check))
 375                vni_field |= VXLAN_RCO_UDP;
 376        return vni_field;
 377}
 378
 379static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
 380{
 381        return vs->sock->sk->sk_family;
 382}
 383
 384#if IS_ENABLED(CONFIG_IPV6)
 385
 386static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
 387{
 388        if (ipa->sa.sa_family == AF_INET6)
 389                return ipv6_addr_any(&ipa->sin6.sin6_addr);
 390        else
 391                return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
 392}
 393
 394static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
 395{
 396        if (ipa->sa.sa_family == AF_INET6)
 397                return ipv6_addr_is_multicast(&ipa->sin6.sin6_addr);
 398        else
 399                return ipv4_is_multicast(ipa->sin.sin_addr.s_addr);
 400}
 401
 402#else /* !IS_ENABLED(CONFIG_IPV6) */
 403
 404static inline bool vxlan_addr_any(const union vxlan_addr *ipa)
 405{
 406        return ipa->sin.sin_addr.s_addr == htonl(INADDR_ANY);
 407}
 408
 409static inline bool vxlan_addr_multicast(const union vxlan_addr *ipa)
 410{
 411        return ipv4_is_multicast(ipa->sin.sin_addr.s_addr);
 412}
 413
 414#endif /* IS_ENABLED(CONFIG_IPV6) */
 415
 416static inline bool netif_is_vxlan(const struct net_device *dev)
 417{
 418        return dev->rtnl_link_ops &&
 419               !strcmp(dev->rtnl_link_ops->kind, "vxlan");
 420}
 421
 422struct switchdev_notifier_vxlan_fdb_info {
 423        struct switchdev_notifier_info info; /* must be first */
 424        union vxlan_addr remote_ip;
 425        __be16 remote_port;
 426        __be32 remote_vni;
 427        u32 remote_ifindex;
 428        u8 eth_addr[ETH_ALEN];
 429        __be32 vni;
 430        bool offloaded;
 431        bool added_by_user;
 432};
 433
 434#if IS_ENABLED(CONFIG_VXLAN)
 435int vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 436                      struct switchdev_notifier_vxlan_fdb_info *fdb_info);
 437int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
 438                     struct notifier_block *nb,
 439                     struct netlink_ext_ack *extack);
 440void vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni);
 441
 442#else
 443static inline int
 444vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 445                  struct switchdev_notifier_vxlan_fdb_info *fdb_info)
 446{
 447        return -ENOENT;
 448}
 449
 450static inline int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
 451                                   struct notifier_block *nb,
 452                                   struct netlink_ext_ack *extack)
 453{
 454        return -EOPNOTSUPP;
 455}
 456
 457static inline void
 458vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni)
 459{
 460}
 461#endif
 462
 463static inline void vxlan_flag_attr_error(int attrtype,
 464                                         struct netlink_ext_ack *extack)
 465{
 466#define VXLAN_FLAG(flg) \
 467        case IFLA_VXLAN_##flg: \
 468                NL_SET_ERR_MSG_MOD(extack, \
 469                                   "cannot change " #flg " flag"); \
 470                break
 471        switch (attrtype) {
 472        VXLAN_FLAG(TTL_INHERIT);
 473        VXLAN_FLAG(LEARNING);
 474        VXLAN_FLAG(PROXY);
 475        VXLAN_FLAG(RSC);
 476        VXLAN_FLAG(L2MISS);
 477        VXLAN_FLAG(L3MISS);
 478        VXLAN_FLAG(COLLECT_METADATA);
 479        VXLAN_FLAG(UDP_ZERO_CSUM6_TX);
 480        VXLAN_FLAG(UDP_ZERO_CSUM6_RX);
 481        VXLAN_FLAG(REMCSUM_TX);
 482        VXLAN_FLAG(REMCSUM_RX);
 483        VXLAN_FLAG(GBP);
 484        VXLAN_FLAG(GPE);
 485        VXLAN_FLAG(REMCSUM_NOPARTIAL);
 486        default:
 487                NL_SET_ERR_MSG_MOD(extack, \
 488                                   "cannot change flag");
 489                break;
 490        }
 491#undef VXLAN_FLAG
 492}
 493
 494static inline bool vxlan_fdb_nh_path_select(struct nexthop *nh,
 495                                            int hash,
 496                                            struct vxlan_rdst *rdst)
 497{
 498        struct fib_nh_common *nhc;
 499
 500        nhc = nexthop_path_fdb_result(nh, hash);
 501        if (unlikely(!nhc))
 502                return false;
 503
 504        switch (nhc->nhc_gw_family) {
 505        case AF_INET:
 506                rdst->remote_ip.sin.sin_addr.s_addr = nhc->nhc_gw.ipv4;
 507                rdst->remote_ip.sa.sa_family = AF_INET;
 508                break;
 509        case AF_INET6:
 510                rdst->remote_ip.sin6.sin6_addr = nhc->nhc_gw.ipv6;
 511                rdst->remote_ip.sa.sa_family = AF_INET6;
 512                break;
 513        }
 514
 515        return true;
 516}
 517
 518#endif
 519