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         __be32                  label;
 166         u32                     flags;
 167         unsigned long           age_interval;
 168         unsigned int            addrmax;
 169         bool                    no_share;
 170 };
 171
 172 /* Pseudo network device */
 173 struct vxlan_dev {
 174         struct hlist_node hlist;        /* vni hash table */
 175         struct list_head  next;         /* vxlan's per namespace list */
 176         struct vxlan_sock *vn4_sock;    /* listening socket for IPv4 */
 177 #if IS_ENABLED(CONFIG_IPV6)
 178         struct vxlan_sock *vn6_sock;    /* listening socket for IPv6 */
 179 #endif
 180         struct net_device *dev;
 181         struct net        *net;         /* netns for packet i/o */
 182         struct vxlan_rdst default_dst;  /* default destination */
 183         u32               flags;        /* VXLAN_F_* in vxlan.h */
 184
 185         struct timer_list age_timer;
 186         spinlock_t        hash_lock;
 187         unsigned int      addrcnt;
 188         struct gro_cells  gro_cells;
 189
 190         struct vxlan_config     cfg;
 191
 192         struct hlist_head fdb_head[FDB_HASH_SIZE];
 193 };
 194
 195 #define VXLAN_F_LEARN                   0x01
 196 #define VXLAN_F_PROXY                   0x02
 197 #define VXLAN_F_RSC                     0x04
 198 #define VXLAN_F_L2MISS                  0x08
 199 #define VXLAN_F_L3MISS                  0x10
 200 #define VXLAN_F_IPV6                    0x20
 201 #define VXLAN_F_UDP_ZERO_CSUM_TX        0x40
 202 #define VXLAN_F_UDP_ZERO_CSUM6_TX       0x80
 203 #define VXLAN_F_UDP_ZERO_CSUM6_RX       0x100
 204 #define VXLAN_F_REMCSUM_TX              0x200
 205 #define VXLAN_F_REMCSUM_RX              0x400
 206 #define VXLAN_F_GBP                     0x800
 207 #define VXLAN_F_REMCSUM_NOPARTIAL       0x1000
 208 #define VXLAN_F_COLLECT_METADATA        0x2000
 209
 210 /* Flags that are used in the receive path. These flags must match in
 211  * order for a socket to be shareable
 212  */
 213 #define VXLAN_F_RCV_FLAGS               (VXLAN_F_GBP |                  \
 214                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
 215                                          VXLAN_F_REMCSUM_RX |           \
 216                                          VXLAN_F_REMCSUM_NOPARTIAL |    \
 217                                          VXLAN_F_COLLECT_METADATA)
 218
 219 struct net_device *vxlan_dev_create(struct net *net, const char *name,
 220                                     u8 name_assign_type, struct vxlan_config *conf);
 221
 222 static inline __be16 vxlan_dev_dst_port(struct vxlan_dev *vxlan,
 223                                         unsigned short family)
 224 {
 225 #if IS_ENABLED(CONFIG_IPV6)
 226         if (family == AF_INET6)
 227                 return inet_sk(vxlan->vn6_sock->sock->sk)->inet_sport;
 228 #endif
 229         return inet_sk(vxlan->vn4_sock->sock->sk)->inet_sport;
 230 }
 231
 232 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,
 233                                                      netdev_features_t features)
 234 {
 235         u8 l4_hdr = 0;
 236
 237         if (!skb->encapsulation)
 238                 return features;
 239
 240         switch (vlan_get_protocol(skb)) {
 241         case htons(ETH_P_IP):
 242                 l4_hdr = ip_hdr(skb)->protocol;
 243                 break;
 244         case htons(ETH_P_IPV6):
 245                 l4_hdr = ipv6_hdr(skb)->nexthdr;
 246                 break;
 247         default:
 248                 return features;;
 249         }
 250
 251         if ((l4_hdr == IPPROTO_UDP) &&
 252             (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
 253              skb->inner_protocol != htons(ETH_P_TEB) ||
 254              (skb_inner_mac_header(skb) - skb_transport_header(skb) !=
 255               sizeof(struct udphdr) + sizeof(struct vxlanhdr)) ||
 256              (skb->ip_summed != CHECKSUM_NONE &&
 257               !can_checksum_protocol(features, inner_eth_hdr(skb)->h_proto))))
 258                 return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
 259
 260         return features;
 261 }
 262
 263 /* IP header + UDP + VXLAN + Ethernet header */
 264 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
 265 /* IPv6 header + UDP + VXLAN + Ethernet header */
 266 #define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
 267
 268 static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb)
 269 {
 270         return (struct vxlanhdr *)(udp_hdr(skb) + 1);
 271 }
 272
 273 static inline __be32 vxlan_vni(__be32 vni_field)
 274 {
 275 #if defined(__BIG_ENDIAN)
 276         return (__force __be32)((__force u32)vni_field >> 8);
 277 #else
 278         return (__force __be32)((__force u32)(vni_field & VXLAN_VNI_MASK) << 8);
 279 #endif
 280 }
 281
 282 static inline __be32 vxlan_vni_field(__be32 vni)
 283 {
 284 #if defined(__BIG_ENDIAN)
 285         return (__force __be32)((__force u32)vni << 8);
 286 #else
 287         return (__force __be32)((__force u32)vni >> 8);
 288 #endif
 289 }
 290
 291 static inline __be32 vxlan_tun_id_to_vni(__be64 tun_id)
 292 {
 293 #if defined(__BIG_ENDIAN)
 294         return (__force __be32)tun_id;
 295 #else
 296         return (__force __be32)((__force u64)tun_id >> 32);
 297 #endif
 298 }
 299
 300 static inline __be64 vxlan_vni_to_tun_id(__be32 vni)
 301 {
 302 #if defined(__BIG_ENDIAN)
 303         return (__force __be64)vni;
 304 #else
 305         return (__force __be64)((u64)(__force u32)vni << 32);
 306 #endif
 307 }
 308
 309 static inline size_t vxlan_rco_start(__be32 vni_field)
 310 {
 311         return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
 312 }
 313
 314 static inline size_t vxlan_rco_offset(__be32 vni_field)
 315 {
 316         return (vni_field & VXLAN_RCO_UDP) ?
 317                 offsetof(struct udphdr, check) :
 318                 offsetof(struct tcphdr, check);
 319 }
 320
 321 static inline __be32 vxlan_compute_rco(unsigned int start, unsigned int offset)
 322 {
 323         __be32 vni_field = cpu_to_be32(start >> VXLAN_RCO_SHIFT);
 324
 325         if (offset == offsetof(struct udphdr, check))
 326                 vni_field |= VXLAN_RCO_UDP;
 327         return vni_field;
 328 }
 329
 330 #if IS_ENABLED(CONFIG_VXLAN)
 331 void vxlan_get_rx_port(struct net_device *netdev);
 332 #else
 333 static inline void vxlan_get_rx_port(struct net_device *netdev)
 334 {
 335 }
 336 #endif
 337
 338 static inline unsigned short vxlan_get_sk_family(struct vxlan_sock *vs)
 339 {
 340         return vs->sock->sk->sk_family;
 341 }
 342
 343 #endif