include/net/vxlan.h

   1 #ifndef __NET_VXLAN_H
   2 #define __NET_VXLAN_H 1
   3
   4 #include <linux/if_vlan.h>
   5 #include <net/udp_tunnel.h>
   6 #include <net/dst_metadata.h>
   7 #include <net/udp_tunnel.h>
   8
   9 /* VXLAN protocol (RFC 7348) header:
  10  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  11  * |R|R|R|R|I|R|R|R|               Reserved                        |
  12  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  13  * |                VXLAN Network Identifier (VNI) |   Reserved    |
  14  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  15  *
  16  * I = VXLAN Network Identifier (VNI) present.
  17  */
  18 struct vxlanhdr {
  19         __be32 vx_flags;
  20         __be32 vx_vni;
  21 };
  22
  23 /* VXLAN header flags. */
  24 #define VXLAN_HF_VNI    cpu_to_be32(BIT(27))
  25
  26 #define VXLAN_N_VID     (1u << 24)
  27 #define VXLAN_VID_MASK  (VXLAN_N_VID - 1)
  28 #define VXLAN_VNI_MASK  cpu_to_be32(VXLAN_VID_MASK << 8)
  29 #define VXLAN_HLEN (sizeof(struct udphdr) + sizeof(struct vxlanhdr))
  30
  31 #define VNI_HASH_BITS   10
  32 #define VNI_HASH_SIZE   (1<<VNI_HASH_BITS)
  33 #define FDB_HASH_BITS   8
  34 #define FDB_HASH_SIZE   (1<<FDB_HASH_BITS)
  35
  36 /* Remote checksum offload for VXLAN (VXLAN_F_REMCSUM_[RT]X):
  37  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  38  * |R|R|R|R|I|R|R|R|R|R|C|              Reserved                   |
  39  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  40  * |           VXLAN Network Identifier (VNI)      |O| Csum start  |
  41  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  42  *
  43  * C = Remote checksum offload bit. When set indicates that the
  44  *     remote checksum offload data is present.
  45  *
  46  * O = Offset bit. Indicates the checksum offset relative to
  47  *     checksum start.
  48  *
  49  * Csum start = Checksum start divided by two.
  50  *
  51  * http://tools.ietf.org/html/draft-herbert-vxlan-rco
  52  */
  53
  54 /* VXLAN-RCO header flags. */
  55 #define VXLAN_HF_RCO    cpu_to_be32(BIT(21))
  56
  57 /* Remote checksum offload header option */
  58 #define VXLAN_RCO_MASK  cpu_to_be32(0x7f)  /* Last byte of vni field */
  59 #define VXLAN_RCO_UDP   cpu_to_be32(0x80)  /* Indicate UDP RCO (TCP when not set *) */
  60 #define VXLAN_RCO_SHIFT 1                  /* Left shift of start */
  61 #define VXLAN_RCO_SHIFT_MASK ((1 << VXLAN_RCO_SHIFT) - 1)
  62 #define VXLAN_MAX_REMCSUM_START (0x7f << VXLAN_RCO_SHIFT)
  63
  64 /*
  65  * VXLAN Group Based Policy Extension (VXLAN_F_GBP):
  66  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  67  * |G|R|R|R|I|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
  68  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  69  * |                VXLAN Network Identifier (VNI) |   Reserved    |
  70  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  71  *
  72  * G = Group Policy ID present.
  73  *
  74  * D = Don't Learn bit. When set, this bit indicates that the egress
  75  *     VTEP MUST NOT learn the source address of the encapsulated frame.
  76  *
  77  * A = Indicates that the group policy has already been applied to
  78  *     this packet. Policies MUST NOT be applied by devices when the
  79  *     A bit is set.
  80  *
  81  * https://tools.ietf.org/html/draft-smith-vxlan-group-policy
  82  */
  83 struct vxlanhdr_gbp {
  84         u8      vx_flags;
  85 #ifdef __LITTLE_ENDIAN_BITFIELD
  86         u8      reserved_flags1:3,
  87                 policy_applied:1,
  88                 reserved_flags2:2,
  89                 dont_learn:1,
  90                 reserved_flags3:1;
  91 #elif defined(__BIG_ENDIAN_BITFIELD)
  92         u8      reserved_flags1:1,
  93                 dont_learn:1,
  94                 reserved_flags2:2,
  95                 policy_applied:1,
  96                 reserved_flags3:3;
  97 #else
  98 #error  "Please fix <asm/byteorder.h>"
  99 #endif
 100         __be16  policy_id;
 101         __be32  vx_vni;
 102 };
 103
 104 /* VXLAN-GBP header flags. */
 105 #define VXLAN_HF_GBP    cpu_to_be32(BIT(31))
 106
 107 #define VXLAN_GBP_USED_BITS (VXLAN_HF_GBP | cpu_to_be32(0xFFFFFF))
 108
 109 /* skb->mark mapping
 110  *
 111  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 112  * |R|R|R|R|R|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
 113  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 114  */
 115 #define VXLAN_GBP_DONT_LEARN            (BIT(6) << 16)
 116 #define VXLAN_GBP_POLICY_APPLIED        (BIT(3) << 16)
 117 #define VXLAN_GBP_ID_MASK               (0xFFFF)
 118
 119 /*
 120  * VXLAN Generic Protocol Extension (VXLAN_F_GPE):
 121  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 122  * |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
 123  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 124  * |                VXLAN Network Identifier (VNI) |   Reserved    |
 125  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 126  *
 127  * Ver = Version. Indicates VXLAN GPE protocol version.
 128  *
 129  * P = Next Protocol Bit. The P bit is set to indicate that the
 130  *     Next Protocol field is present.
 131  *
 132  * O = OAM Flag Bit. The O bit is set to indicate that the packet
 133  *     is an OAM packet.
 134  *
 135  * Next Protocol = This 8 bit field indicates the protocol header
 136  * immediately following the VXLAN GPE header.
 137  *
 138  * https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-01
 139  */
 140
 141 struct vxlanhdr_gpe {
 142 #if defined(__LITTLE_ENDIAN_BITFIELD)
 143         u8      oam_flag:1,
 144                 reserved_flags1:1,
 145                 np_applied:1,
 146                 instance_applied:1,
 147                 version:2,
 148 reserved_flags2:2;
 149 #elif defined(__BIG_ENDIAN_BITFIELD)
 150         u8      reserved_flags2:2,
 151                 version:2,
 152                 instance_applied:1,
 153                 np_applied:1,
 154                 reserved_flags1:1,
 155                 oam_flag:1;
 156 #endif
 157         u8      reserved_flags3;
 158         u8      reserved_flags4;
 159         u8      next_protocol;
 160         __be32  vx_vni;
 161 };
 162
 163 /* VXLAN-GPE header flags. */
 164 #define VXLAN_HF_VER    cpu_to_be32(BIT(29) | BIT(28))
 165 #define VXLAN_HF_NP     cpu_to_be32(BIT(26))
 166 #define VXLAN_HF_OAM    cpu_to_be32(BIT(24))
 167
 168 #define VXLAN_GPE_USED_BITS (VXLAN_HF_VER | VXLAN_HF_NP | VXLAN_HF_OAM | \
 169                              cpu_to_be32(0xff))
 170
 171 /* VXLAN-GPE header Next Protocol. */
 172 #define VXLAN_GPE_NP_IPV4      0x01
 173 #define VXLAN_GPE_NP_IPV6      0x02
 174 #define VXLAN_GPE_NP_ETHERNET  0x03
 175 #define VXLAN_GPE_NP_NSH       0x04
 176
 177 struct vxlan_metadata {
 178         u32             gbp;
 179 };
 180
 181 /* per UDP socket information */
 182 struct vxlan_sock {
 183         struct hlist_node hlist;
 184         struct socket    *sock;
 185         struct hlist_head vni_list[VNI_HASH_SIZE];
 186         atomic_t          refcnt;
 187         u32               flags;
 188 };
 189
 190 union vxlan_addr {
 191         struct sockaddr_in sin;
 192         struct sockaddr_in6 sin6;
 193         struct sockaddr sa;
 194 };
 195
 196 struct vxlan_rdst {
 197         union vxlan_addr         remote_ip;
 198         __be16                   remote_port;
 199         __be32                   remote_vni;
 200         u32                      remote_ifindex;
 201         struct list_head         list;
 202         struct rcu_head          rcu;
 203         struct dst_cache         dst_cache;
 204 };
 205
 206 struct vxlan_config {
 207         union vxlan_addr        remote_ip;
 208         union vxlan_addr        saddr;
 209         __be32                  vni;
 210         int                     remote_ifindex;
 211         int                     mtu;
 212         __be16                  dst_port;
 213         u16                     port_min;
 214         u16                     port_max;
 215         u8                      tos;
 216         u8                      ttl;
 217         __be32                  label;
 218         u32                     flags;
 219         unsigned long           age_interval;
 220         unsigned int            addrmax;
 221         bool                    no_share;
 222 };
 223
 224 /* Pseudo network device */
 225 struct vxlan_dev {
 226         struct hlist_node hlist;        /* vni hash table */
 227         struct list_head  next;         /* vxlan's per namespace list */
 228         struct vxlan_sock __rcu *vn4_sock;      /* listening socket for IPv4 */
 229 #if IS_ENABLED(CONFIG_IPV6)
 230         struct vxlan_sock __rcu *vn6_sock;      /* listening socket for IPv6 */
 231 #endif
 232         struct net_device *dev;
 233         struct net        *net;         /* netns for packet i/o */
 234         struct vxlan_rdst default_dst;  /* default destination */
 235         u32               flags;        /* VXLAN_F_* in vxlan.h */
 236
 237         struct timer_list age_timer;
 238         spinlock_t        hash_lock;
 239         unsigned int      addrcnt;
 240         struct gro_cells  gro_cells;
 241
 242         struct vxlan_config     cfg;
 243
 244         struct hlist_head fdb_head[FDB_HASH_SIZE];
 245 };
 246
 247 #define VXLAN_F_LEARN                   0x01
 248 #define VXLAN_F_PROXY                   0x02
 249 #define VXLAN_F_RSC                     0x04
 250 #define VXLAN_F_L2MISS                  0x08
 251 #define VXLAN_F_L3MISS                  0x10
 252 #define VXLAN_F_IPV6                    0x20
 253 #define VXLAN_F_UDP_ZERO_CSUM_TX        0x40
 254 #define VXLAN_F_UDP_ZERO_CSUM6_TX       0x80
 255 #define VXLAN_F_UDP_ZERO_CSUM6_RX       0x100
 256 #define VXLAN_F_REMCSUM_TX              0x200
 257 #define VXLAN_F_REMCSUM_RX              0x400
 258 #define VXLAN_F_GBP                     0x800
 259 #define VXLAN_F_REMCSUM_NOPARTIAL       0x1000
 260 #define VXLAN_F_COLLECT_METADATA        0x2000
 261 #define VXLAN_F_GPE                     0x4000
 262
 263 /* Flags that are used in the receive path. These flags must match in
 264  * order for a socket to be shareable
 265  */
 266 #define VXLAN_F_RCV_FLAGS               (VXLAN_F_GBP |                  \
 267                                          VXLAN_F_GPE |                  \
 268                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 269                                          VXLAN_F_REMCSUM_RX |           \
 270                                          VXLAN_F_REMCSUM_NOPARTIAL |    \
 271                                          VXLAN_F_COLLECT_METADATA)
 272
 273 /* Flags that can be set together with VXLAN_F_GPE. */
 274 #define VXLAN_F_ALLOWED_GPE             (VXLAN_F_GPE |                  \
 275                                          VXLAN_F_IPV6 |                 \
 276                                          VXLAN_F_UDP_ZERO_CSUM_TX |     \
 277                                          VXLAN_F_UDP_ZERO_CSUM6_TX |    \
 278                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 279                                          VXLAN_F_COLLECT_METADATA)
 280
 281 struct net_device *vxlan_dev_create(struct net *net, const char *name,
 282                                     u8 name_assign_type, struct vxlan_config *conf);
 283
 284 static inline __be16 vxlan_dev_dst_port(struct vxlan_dev *vxlan,
 285                                         unsigned short family)
 286 {
 287 #if IS_ENABLED(CONFIG_IPV6)
 288         if (family == AF_INET6)
 289                 return inet_sk(vxlan->vn6_sock->sock->sk)->inet_sport;
 290 #endif
 291         return inet_sk(vxlan->vn4_sock->sock->sk)->inet_sport;
 292 }
 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 #endif