include/net/vxlan.h

   1 #ifndef __NET_VXLAN_H
   2 #define __NET_VXLAN_H 1
   3
   4 #include <linux/ip.h>
   5 #include <linux/ipv6.h>
   6 #include <linux/if_vlan.h>
   7 #include <linux/skbuff.h>
   8 #include <linux/netdevice.h>
   9 #include <linux/udp.h>
  10 #include <net/dst_metadata.h>
  11
  12 /* VXLAN protocol (RFC 7348) header:
  13  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  14  * |R|R|R|R|I|R|R|R|               Reserved                        |
  15  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  16  * |                VXLAN Network Identifier (VNI) |   Reserved    |
  17  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  18  *
  19  * I = VXLAN Network Identifier (VNI) present.
  20  */
  21 struct vxlanhdr {
  22         __be32 vx_flags;
  23         __be32 vx_vni;
  24 };
  25
  26 /* VXLAN header flags. */
  27 #define VXLAN_HF_VNI    cpu_to_be32(BIT(27))
  28
  29 #define VXLAN_N_VID     (1u << 24)
  30 #define VXLAN_VID_MASK  (VXLAN_N_VID - 1)
  31 #define VXLAN_VNI_MASK  cpu_to_be32(VXLAN_VID_MASK << 8)
  32 #define VXLAN_HLEN (sizeof(struct udphdr) + sizeof(struct vxlanhdr))
  33
  34 #define VNI_HASH_BITS   10
  35 #define VNI_HASH_SIZE   (1<<VNI_HASH_BITS)
  36 #define FDB_HASH_BITS   8
  37 #define FDB_HASH_SIZE   (1<<FDB_HASH_BITS)
  38
  39 /* Remote checksum offload for VXLAN (VXLAN_F_REMCSUM_[RT]X):
  40  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  41  * |R|R|R|R|I|R|R|R|R|R|C|              Reserved                   |
  42  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  43  * |           VXLAN Network Identifier (VNI)      |O| Csum start  |
  44  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  45  *
  46  * C = Remote checksum offload bit. When set indicates that the
  47  *     remote checksum offload data is present.
  48  *
  49  * O = Offset bit. Indicates the checksum offset relative to
  50  *     checksum start.
  51  *
  52  * Csum start = Checksum start divided by two.
  53  *
  54  * http://tools.ietf.org/html/draft-herbert-vxlan-rco
  55  */
  56
  57 /* VXLAN-RCO header flags. */
  58 #define VXLAN_HF_RCO    cpu_to_be32(BIT(21))
  59
  60 /* Remote checksum offload header option */
  61 #define VXLAN_RCO_MASK  cpu_to_be32(0x7f)  /* Last byte of vni field */
  62 #define VXLAN_RCO_UDP   cpu_to_be32(0x80)  /* Indicate UDP RCO (TCP when not set *) */
  63 #define VXLAN_RCO_SHIFT 1                  /* Left shift of start */
  64 #define VXLAN_RCO_SHIFT_MASK ((1 << VXLAN_RCO_SHIFT) - 1)
  65 #define VXLAN_MAX_REMCSUM_START (0x7f << VXLAN_RCO_SHIFT)
  66
  67 /*
  68  * VXLAN Group Based Policy Extension (VXLAN_F_GBP):
  69  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  70  * |G|R|R|R|I|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
  71  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  72  * |                VXLAN Network Identifier (VNI) |   Reserved    |
  73  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  74  *
  75  * G = Group Policy ID present.
  76  *
  77  * D = Don't Learn bit. When set, this bit indicates that the egress
  78  *     VTEP MUST NOT learn the source address of the encapsulated frame.
  79  *
  80  * A = Indicates that the group policy has already been applied to
  81  *     this packet. Policies MUST NOT be applied by devices when the
  82  *     A bit is set.
  83  *
  84  * https://tools.ietf.org/html/draft-smith-vxlan-group-policy
  85  */
  86 struct vxlanhdr_gbp {
  87         u8      vx_flags;
  88 #ifdef __LITTLE_ENDIAN_BITFIELD
  89         u8      reserved_flags1:3,
  90                 policy_applied:1,
  91                 reserved_flags2:2,
  92                 dont_learn:1,
  93                 reserved_flags3:1;
  94 #elif defined(__BIG_ENDIAN_BITFIELD)
  95         u8      reserved_flags1:1,
  96                 dont_learn:1,
  97                 reserved_flags2:2,
  98                 policy_applied:1,
  99                 reserved_flags3:3;
 100 #else
 101 #error  "Please fix <asm/byteorder.h>"
 102 #endif
 103         __be16  policy_id;
 104         __be32  vx_vni;
 105 };
 106
 107 /* VXLAN-GBP header flags. */
 108 #define VXLAN_HF_GBP    cpu_to_be32(BIT(31))
 109
 110 #define VXLAN_GBP_USED_BITS (VXLAN_HF_GBP | cpu_to_be32(0xFFFFFF))
 111
 112 /* skb->mark mapping
 113  *
 114  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 115  * |R|R|R|R|R|R|R|R|R|D|R|R|A|R|R|R|        Group Policy ID        |
 116  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 117  */
 118 #define VXLAN_GBP_DONT_LEARN            (BIT(6) << 16)
 119 #define VXLAN_GBP_POLICY_APPLIED        (BIT(3) << 16)
 120 #define VXLAN_GBP_ID_MASK               (0xFFFF)
 121
 122 /*
 123  * VXLAN Generic Protocol Extension (VXLAN_F_GPE):
 124  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 125  * |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
 126  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 127  * |                VXLAN Network Identifier (VNI) |   Reserved    |
 128  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 129  *
 130  * Ver = Version. Indicates VXLAN GPE protocol version.
 131  *
 132  * P = Next Protocol Bit. The P bit is set to indicate that the
 133  *     Next Protocol field is present.
 134  *
 135  * O = OAM Flag Bit. The O bit is set to indicate that the packet
 136  *     is an OAM packet.
 137  *
 138  * Next Protocol = This 8 bit field indicates the protocol header
 139  * immediately following the VXLAN GPE header.
 140  *
 141  * https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-01
 142  */
 143
 144 struct vxlanhdr_gpe {
 145 #if defined(__LITTLE_ENDIAN_BITFIELD)
 146         u8      oam_flag:1,
 147                 reserved_flags1:1,
 148                 np_applied:1,
 149                 instance_applied:1,
 150                 version:2,
 151 reserved_flags2:2;
 152 #elif defined(__BIG_ENDIAN_BITFIELD)
 153         u8      reserved_flags2:2,
 154                 version:2,
 155                 instance_applied:1,
 156                 np_applied:1,
 157                 reserved_flags1:1,
 158                 oam_flag:1;
 159 #endif
 160         u8      reserved_flags3;
 161         u8      reserved_flags4;
 162         u8      next_protocol;
 163         __be32  vx_vni;
 164 };
 165
 166 /* VXLAN-GPE header flags. */
 167 #define VXLAN_HF_VER    cpu_to_be32(BIT(29) | BIT(28))
 168 #define VXLAN_HF_NP     cpu_to_be32(BIT(26))
 169 #define VXLAN_HF_OAM    cpu_to_be32(BIT(24))
 170
 171 #define VXLAN_GPE_USED_BITS (VXLAN_HF_VER | VXLAN_HF_NP | VXLAN_HF_OAM | \
 172                              cpu_to_be32(0xff))
 173
 174 /* VXLAN-GPE header Next Protocol. */
 175 #define VXLAN_GPE_NP_IPV4      0x01
 176 #define VXLAN_GPE_NP_IPV6      0x02
 177 #define VXLAN_GPE_NP_ETHERNET  0x03
 178 #define VXLAN_GPE_NP_NSH       0x04
 179
 180 struct vxlan_metadata {
 181         u32             gbp;
 182 };
 183
 184 /* per UDP socket information */
 185 struct vxlan_sock {
 186         struct hlist_node hlist;
 187         struct socket    *sock;
 188         struct hlist_head vni_list[VNI_HASH_SIZE];
 189         atomic_t          refcnt;
 190         u32               flags;
 191 };
 192
 193 union vxlan_addr {
 194         struct sockaddr_in sin;
 195         struct sockaddr_in6 sin6;
 196         struct sockaddr sa;
 197 };
 198
 199 struct vxlan_rdst {
 200         union vxlan_addr         remote_ip;
 201         __be16                   remote_port;
 202         __be32                   remote_vni;
 203         u32                      remote_ifindex;
 204         struct list_head         list;
 205         struct rcu_head          rcu;
 206         struct dst_cache         dst_cache;
 207 };
 208
 209 struct vxlan_config {
 210         union vxlan_addr        remote_ip;
 211         union vxlan_addr        saddr;
 212         __be32                  vni;
 213         int                     remote_ifindex;
 214         int                     mtu;
 215         __be16                  dst_port;
 216         u16                     port_min;
 217         u16                     port_max;
 218         u8                      tos;
 219         u8                      ttl;
 220         __be32                  label;
 221         u32                     flags;
 222         unsigned long           age_interval;
 223         unsigned int            addrmax;
 224         bool                    no_share;
 225 };
 226
 227 /* Pseudo network device */
 228 struct vxlan_dev {
 229         struct hlist_node hlist;        /* vni hash table */
 230         struct list_head  next;         /* vxlan's per namespace list */
 231         struct vxlan_sock *vn4_sock;    /* listening socket for IPv4 */
 232 #if IS_ENABLED(CONFIG_IPV6)
 233         struct vxlan_sock *vn6_sock;    /* listening socket for IPv6 */
 234 #endif
 235         struct net_device *dev;
 236         struct net        *net;         /* netns for packet i/o */
 237         struct vxlan_rdst default_dst;  /* default destination */
 238         u32               flags;        /* VXLAN_F_* in vxlan.h */
 239
 240         struct timer_list age_timer;
 241         spinlock_t        hash_lock;
 242         unsigned int      addrcnt;
 243         struct gro_cells  gro_cells;
 244
 245         struct vxlan_config     cfg;
 246
 247         struct hlist_head fdb_head[FDB_HASH_SIZE];
 248 };
 249
 250 #define VXLAN_F_LEARN                   0x01
 251 #define VXLAN_F_PROXY                   0x02
 252 #define VXLAN_F_RSC                     0x04
 253 #define VXLAN_F_L2MISS                  0x08
 254 #define VXLAN_F_L3MISS                  0x10
 255 #define VXLAN_F_IPV6                    0x20
 256 #define VXLAN_F_UDP_ZERO_CSUM_TX        0x40
 257 #define VXLAN_F_UDP_ZERO_CSUM6_TX       0x80
 258 #define VXLAN_F_UDP_ZERO_CSUM6_RX       0x100
 259 #define VXLAN_F_REMCSUM_TX              0x200
 260 #define VXLAN_F_REMCSUM_RX              0x400
 261 #define VXLAN_F_GBP                     0x800
 262 #define VXLAN_F_REMCSUM_NOPARTIAL       0x1000
 263 #define VXLAN_F_COLLECT_METADATA        0x2000
 264 #define VXLAN_F_GPE                     0x4000
 265
 266 /* Flags that are used in the receive path. These flags must match in
 267  * order for a socket to be shareable
 268  */
 269 #define VXLAN_F_RCV_FLAGS               (VXLAN_F_GBP |                  \
 270                                          VXLAN_F_GPE |                  \
 271                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 272                                          VXLAN_F_REMCSUM_RX |           \
 273                                          VXLAN_F_REMCSUM_NOPARTIAL |    \
 274                                          VXLAN_F_COLLECT_METADATA)
 275
 276 /* Flags that can be set together with VXLAN_F_GPE. */
 277 #define VXLAN_F_ALLOWED_GPE             (VXLAN_F_GPE |                  \
 278                                          VXLAN_F_IPV6 |                 \
 279                                          VXLAN_F_UDP_ZERO_CSUM_TX |     \
 280                                          VXLAN_F_UDP_ZERO_CSUM6_TX |    \
 281                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 282                                          VXLAN_F_COLLECT_METADATA)
 283
 284 struct net_device *vxlan_dev_create(struct net *net, const char *name,
 285                                     u8 name_assign_type, struct vxlan_config *conf);
 286
 287 static inline __be16 vxlan_dev_dst_port(struct vxlan_dev *vxlan,
 288                                         unsigned short family)
 289 {
 290 #if IS_ENABLED(CONFIG_IPV6)
 291         if (family == AF_INET6)
 292                 return inet_sk(vxlan->vn6_sock->sock->sk)->inet_sport;
 293 #endif
 294         return inet_sk(vxlan->vn4_sock->sock->sk)->inet_sport;
 295 }
 296
 297 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
 298                                                      netdev_features_t features)
 299 {
 300         u8 l4_hdr = 0;
 301
 302         if (!skb->encapsulation)
 303                 return features;
 304
 305         switch (vlan_get_protocol(skb)) {
 306         case htons(ETH_P_IP):
 307                 l4_hdr = ip_hdr(skb)->protocol;
 308                 break;
 309         case htons(ETH_P_IPV6):
 310                 l4_hdr = ipv6_hdr(skb)->nexthdr;
 311                 break;
 312         default:
 313                 return features;;
 314         }
 315
 316         if ((l4_hdr == IPPROTO_UDP) &&
 317             (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
 318              skb->inner_protocol != htons(ETH_P_TEB) ||
 319              (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
 320               sizeof(struct udphdr) + sizeof(struct vxlanhdr))))
 321                 return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
 322
 323         return features;
 324 }
 325
 326 /* IP header + UDP + VXLAN + Ethernet header */
 327 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
 328 /* IPv6 header + UDP + VXLAN + Ethernet header */
 329 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
 330
 331 static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
 332 {
 333         return (struct vxlanhdr *)(udp_hdr(skb) + 1);
 334 }
 335
 336 static inline __be32 vxlan_vni(__be32 vni_field)
 337 {
 338 #if defined(__BIG_ENDIAN)
 339         return (__force __be32)((__force u32)vni_field >> 8);
 340 #else
 341         return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
 342 #endif
 343 }
 344
 345 static inline __be32 vxlan_vni_field(__be32 vni)
 346 {
 347 #if defined(__BIG_ENDIAN)
 348         return (__force __be32)((__force u32)vni << 8);
 349 #else
 350         return (__force __be32)((__force u32)vni >> 8);
 351 #endif
 352 }
 353
 354 static inline __be32 vxlan_tun_id_to_vni(__be64 tun_id)
 355 {
 356 #if defined(__BIG_ENDIAN)
 357         return (__force __be32)tun_id;
 358 #else
 359         return (__force __be32)((__force u64)tun_id >> 32);
 360 #endif
 361 }
 362
 363 static inline __be64 vxlan_vni_to_tun_id(__be32 vni)
 364 {
 365 #if defined(__BIG_ENDIAN)
 366         return (__force __be64)vni;
 367 #else
 368         return (__force __be64)((u64)(__force u32)vni << 32);
 369 #endif
 370 }
 371
 372 static inline size_t vxlan_rco_start(__be32 vni_field)
 373 {
 374         return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
 375 }
 376
 377 static inline size_t vxlan_rco_offset(__be32 vni_field)
 378 {
 379         return (vni_field & VXLAN_RCO_UDP) ?
 380                 offsetof(struct udphdr, check) :
 381                 offsetof(struct tcphdr, check);
 382 }
 383
 384 static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
 385 {
 386         __be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
 387
 388         if (offset == offsetof(struct udphdr, check))
 389                 vni_field |= VXLAN_RCO_UDP;
 390         return vni_field;
 391 }
 392
 393 static inline void vxlan_get_rx_port(struct net_device *netdev)
 394 {
 395         ASSERT_RTNL();
 396         call_netdevice_notifiers(NETDEV_OFFLOAD_PUSH_VXLAN, netdev);
 397 }
 398
 399 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
 400 {
 401         return vs->sock->sk->sk_family;
 402 }
 403
 404 #endif