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 struct vxlan_metadata {
 123         u32             gbp;
 124 };
 125
 126 /* per UDP socket information */
 127 struct vxlan_sock {
 128         struct hlist_node hlist;
 129         struct work_struct del_work;
 130         struct socket    *sock;
 131         struct rcu_head   rcu;
 132         struct hlist_head vni_list[VNI_HASH_SIZE];
 133         atomic_t          refcnt;
 134         struct udp_offload udp_offloads;
 135         u32               flags;
 136 };
 137
 138 union vxlan_addr {
 139         struct sockaddr_in sin;
 140         struct sockaddr_in6 sin6;
 141         struct sockaddr sa;
 142 };
 143
 144 struct vxlan_rdst {
 145         union vxlan_addr         remote_ip;
 146         __be16                   remote_port;
 147         __be32                   remote_vni;
 148         u32                      remote_ifindex;
 149         struct list_head         list;
 150         struct rcu_head          rcu;
 151         struct dst_cache         dst_cache;
 152 };
 153
 154 struct vxlan_config {
 155         union vxlan_addr        remote_ip;
 156         union vxlan_addr        saddr;
 157         __be32                  vni;
 158         int                     remote_ifindex;
 159         int                     mtu;
 160         __be16                  dst_port;
 161         u16                     port_min;
 162         u16                     port_max;
 163         u8                      tos;
 164         u8                      ttl;
 165         u32                     flags;
 166         unsigned long           age_interval;
 167         unsigned int            addrmax;
 168         bool                    no_share;
 169 };
 170
 171 /* Pseudo network device */
 172 struct vxlan_dev {
 173         struct hlist_node hlist;        /* vni hash table */
 174         struct list_head  next;         /* vxlan's per namespace list */
 175         struct vxlan_sock *vn4_sock;    /* listening socket for IPv4 */
 176 #if IS_ENABLED(CONFIG_IPV6)
 177         struct vxlan_sock *vn6_sock;    /* listening socket for IPv6 */
 178 #endif
 179         struct net_device *dev;
 180         struct net        *net;         /* netns for packet i/o */
 181         struct vxlan_rdst default_dst;  /* default destination */
 182         u32               flags;        /* VXLAN_F_* in vxlan.h */
 183
 184         struct timer_list age_timer;
 185         spinlock_t        hash_lock;
 186         unsigned int      addrcnt;
 187         struct gro_cells  gro_cells;
 188
 189         struct vxlan_config     cfg;
 190
 191         struct hlist_head fdb_head[FDB_HASH_SIZE];
 192 };
 193
 194 #define VXLAN_F_LEARN                   0x01
 195 #define VXLAN_F_PROXY                   0x02
 196 #define VXLAN_F_RSC                     0x04
 197 #define VXLAN_F_L2MISS                  0x08
 198 #define VXLAN_F_L3MISS                  0x10
 199 #define VXLAN_F_IPV6                    0x20
 200 #define VXLAN_F_UDP_CSUM                0x40
 201 #define VXLAN_F_UDP_ZERO_CSUM6_TX       0x80
 202 #define VXLAN_F_UDP_ZERO_CSUM6_RX       0x100
 203 #define VXLAN_F_REMCSUM_TX              0x200
 204 #define VXLAN_F_REMCSUM_RX              0x400
 205 #define VXLAN_F_GBP                     0x800
 206 #define VXLAN_F_REMCSUM_NOPARTIAL       0x1000
 207 #define VXLAN_F_COLLECT_METADATA        0x2000
 208
 209 /* Flags that are used in the receive path. These flags must match in
 210  * order for a socket to be shareable
 211  */
 212 #define VXLAN_F_RCV_FLAGS               (VXLAN_F_GBP |                  \
 213                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 214                                          VXLAN_F_REMCSUM_RX |           \
 215                                          VXLAN_F_REMCSUM_NOPARTIAL |    \
 216                                          VXLAN_F_COLLECT_METADATA)
 217
 218 struct net_device *vxlan_dev_create(struct net *net, const char *name,
 219                                     u8 name_assign_type, struct vxlan_config *conf);
 220
 221 static inline __be16 vxlan_dev_dst_port(struct vxlan_dev *vxlan,
 222                                         unsigned short family)
 223 {
 224 #if IS_ENABLED(CONFIG_IPV6)
 225         if (family == AF_INET6)
 226                 return inet_sk(vxlan->vn6_sock->sock->sk)->inet_sport;
 227 #endif
 228         return inet_sk(vxlan->vn4_sock->sock->sk)->inet_sport;
 229 }
 230
 231 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
 232                                                      netdev_features_t features)
 233 {
 234         u8 l4_hdr = 0;
 235
 236         if (!skb->encapsulation)
 237                 return features;
 238
 239         switch (vlan_get_protocol(skb)) {
 240         case htons(ETH_P_IP):
 241                 l4_hdr = ip_hdr(skb)->protocol;
 242                 break;
 243         case htons(ETH_P_IPV6):
 244                 l4_hdr = ipv6_hdr(skb)->nexthdr;
 245                 break;
 246         default:
 247                 return features;;
 248         }
 249
 250         if ((l4_hdr == IPPROTO_UDP) &&
 251             (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
 252              skb->inner_protocol != htons(ETH_P_TEB) ||
 253              (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
 254               sizeof(struct udphdr) + sizeof(struct vxlanhdr))))
 255                 return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
 256
 257         return features;
 258 }
 259
 260 /* IP header + UDP + VXLAN + Ethernet header */
 261 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
 262 /* IPv6 header + UDP + VXLAN + Ethernet header */
 263 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
 264
 265 static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
 266 {
 267         return (struct vxlanhdr *)(udp_hdr(skb) + 1);
 268 }
 269
 270 static inline __be32 vxlan_vni(__be32 vni_field)
 271 {
 272 #if defined(__BIG_ENDIAN)
 273         return vni_field >> 8;
 274 #else
 275         return (vni_field & VXLAN_VNI_MASK) << 8;
 276 #endif
 277 }
 278
 279 static inline __be32 vxlan_vni_field(__be32 vni)
 280 {
 281 #if defined(__BIG_ENDIAN)
 282         return vni << 8;
 283 #else
 284         return vni >> 8;
 285 #endif
 286 }
 287
 288 static inline __be32 vxlan_tun_id_to_vni(__be64 tun_id)
 289 {
 290 #if defined(__BIG_ENDIAN)
 291         return tun_id;
 292 #else
 293         return tun_id >> 32;
 294 #endif
 295 }
 296
 297 static inline __be64 vxlan_vni_to_tun_id(__be32 vni)
 298 {
 299 #if defined(__BIG_ENDIAN)
 300         return (__be64)vni;
 301 #else
 302         return (__be64)vni << 32;
 303 #endif
 304 }
 305
 306 static inline size_t vxlan_rco_start(__be32 vni_field)
 307 {
 308         return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
 309 }
 310
 311 static inline size_t vxlan_rco_offset(__be32 vni_field)
 312 {
 313         return (vni_field & VXLAN_RCO_UDP) ?
 314                 offsetof(struct udphdr, check) :
 315                 offsetof(struct tcphdr, check);
 316 }
 317
 318 static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
 319 {
 320         __be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
 321
 322         if (offset == offsetof(struct udphdr, check))
 323                 vni_field |= VXLAN_RCO_UDP;
 324         return vni_field;
 325 }
 326
 327 #if IS_ENABLED(CONFIG_VXLAN)
 328 void vxlan_get_rx_port(struct net_device *netdev);
 329 #else
 330 static inline void vxlan_get_rx_port(struct net_device *netdev)
 331 {
 332 }
 333 #endif
 334
 335 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
 336 {
 337         return vs->sock->sk->sk_family;
 338 }
 339
 340 #endif