include/net/udp_tunnel.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __NET_UDP_TUNNEL_H
   3 #define __NET_UDP_TUNNEL_H
   4
   5 #include <net/ip_tunnels.h>
   6 #include <net/udp.h>
   7
   8 #if IS_ENABLED(CONFIG_IPV6)
   9 #include <net/ipv6.h>
  10 #include <net/ipv6_stubs.h>
  11 #endif
  12
  13 struct udp_port_cfg {
  14         u8                      family;
  15
  16         /* Used only for kernel-created sockets */
  17         union {
  18                 struct in_addr          local_ip;
  19 #if IS_ENABLED(CONFIG_IPV6)
  20                 struct in6_addr         local_ip6;
  21 #endif
  22         };
  23
  24         union {
  25                 struct in_addr          peer_ip;
  26 #if IS_ENABLED(CONFIG_IPV6)
  27                 struct in6_addr         peer_ip6;
  28 #endif
  29         };
  30
  31         __be16                  local_udp_port;
  32         __be16                  peer_udp_port;
  33         int                     bind_ifindex;
  34         unsigned int            use_udp_checksums:1,
  35                                 use_udp6_tx_checksums:1,
  36                                 use_udp6_rx_checksums:1,
  37                                 ipv6_v6only:1;
  38 };
  39
  40 int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
  41                      struct socket **sockp);
  42
  43 #if IS_ENABLED(CONFIG_IPV6)
  44 int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg,
  45                      struct socket **sockp);
  46 #else
  47 static inline int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg,
  48                                    struct socket **sockp)
  49 {
  50         return 0;
  51 }
  52 #endif
  53
  54 static inline int udp_sock_create(struct net *net,
  55                                   struct udp_port_cfg *cfg,
  56                                   struct socket **sockp)
  57 {
  58         if (cfg->family == AF_INET)
  59                 return udp_sock_create4(net, cfg, sockp);
  60
  61         if (cfg->family == AF_INET6)
  62                 return udp_sock_create6(net, cfg, sockp);
  63
  64         return -EPFNOSUPPORT;
  65 }
  66
  67 typedef int (*udp_tunnel_encap_rcv_t)(struct sock *sk, struct sk_buff *skb);
  68 typedef int (*udp_tunnel_encap_err_lookup_t)(struct sock *sk,
  69                                              struct sk_buff *skb);
  70 typedef void (*udp_tunnel_encap_err_rcv_t)(struct sock *sk,
  71                                            struct sk_buff *skb, int err,
  72                                            __be16 port, u32 info, u8 *payload);
  73 typedef void (*udp_tunnel_encap_destroy_t)(struct sock *sk);
  74 typedef struct sk_buff *(*udp_tunnel_gro_receive_t)(struct sock *sk,
  75                                                     struct list_head *head,
  76                                                     struct sk_buff *skb);
  77 typedef int (*udp_tunnel_gro_complete_t)(struct sock *sk, struct sk_buff *skb,
  78                                          int nhoff);
  79
  80 struct udp_tunnel_sock_cfg {
  81         void *sk_user_data;     /* user data used by encap_rcv call back */
  82         /* Used for setting up udp_sock fields, see udp.h for details */
  83         __u8  encap_type;
  84         udp_tunnel_encap_rcv_t encap_rcv;
  85         udp_tunnel_encap_err_lookup_t encap_err_lookup;
  86         udp_tunnel_encap_err_rcv_t encap_err_rcv;
  87         udp_tunnel_encap_destroy_t encap_destroy;
  88         udp_tunnel_gro_receive_t gro_receive;
  89         udp_tunnel_gro_complete_t gro_complete;
  90 };
  91
  92 /* Setup the given (UDP) sock to receive UDP encapsulated packets */
  93 void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
  94                            struct udp_tunnel_sock_cfg *sock_cfg);
  95
  96 /* -- List of parsable UDP tunnel types --
  97  *
  98  * Adding to this list will result in serious debate.  The main issue is
  99  * that this list is essentially a list of workarounds for either poorly
 100  * designed tunnels, or poorly designed device offloads.
 101  *
 102  * The parsing supported via these types should really be used for Rx
 103  * traffic only as the network stack will have already inserted offsets for
 104  * the location of the headers in the skb.  In addition any ports that are
 105  * pushed should be kept within the namespace without leaking to other
 106  * devices such as VFs or other ports on the same device.
 107  *
 108  * It is strongly encouraged to use CHECKSUM_COMPLETE for Rx to avoid the
 109  * need to use this for Rx checksum offload.  It should not be necessary to
 110  * call this function to perform Tx offloads on outgoing traffic.
 111  */
 112 enum udp_parsable_tunnel_type {
 113         UDP_TUNNEL_TYPE_VXLAN     = BIT(0), /* RFC 7348 */
 114         UDP_TUNNEL_TYPE_GENEVE    = BIT(1), /* draft-ietf-nvo3-geneve */
 115         UDP_TUNNEL_TYPE_VXLAN_GPE = BIT(2), /* draft-ietf-nvo3-vxlan-gpe */
 116 };
 117
 118 struct udp_tunnel_info {
 119         unsigned short type;
 120         sa_family_t sa_family;
 121         __be16 port;
 122         u8 hw_priv;
 123 };
 124
 125 /* Notify network devices of offloadable types */
 126 void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
 127                              unsigned short type);
 128 void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
 129                              unsigned short type);
 130 void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type);
 131 void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type);
 132
 133 static inline void udp_tunnel_get_rx_info(struct net_device *dev)
 134 {
 135         ASSERT_RTNL();
 136         if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
 137                 return;
 138         call_netdevice_notifiers(NETDEV_UDP_TUNNEL_PUSH_INFO, dev);
 139 }
 140
 141 static inline void udp_tunnel_drop_rx_info(struct net_device *dev)
 142 {
 143         ASSERT_RTNL();
 144         if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
 145                 return;
 146         call_netdevice_notifiers(NETDEV_UDP_TUNNEL_DROP_INFO, dev);
 147 }
 148
 149 /* Transmit the skb using UDP encapsulation. */
 150 void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
 151                          __be32 src, __be32 dst, __u8 tos, __u8 ttl,
 152                          __be16 df, __be16 src_port, __be16 dst_port,
 153                          bool xnet, bool nocheck);
 154
 155 int udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
 156                          struct sk_buff *skb,
 157                          struct net_device *dev,
 158                          const struct in6_addr *saddr,
 159                          const struct in6_addr *daddr,
 160                          __u8 prio, __u8 ttl, __be32 label,
 161                          __be16 src_port, __be16 dst_port, bool nocheck);
 162
 163 void udp_tunnel_sock_release(struct socket *sock);
 164
 165 struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
 166                                      struct net_device *dev,
 167                                      struct net *net, int oif,
 168                                      __be32 *saddr,
 169                                      const struct ip_tunnel_key *key,
 170                                      __be16 sport, __be16 dport, u8 tos,
 171                                      struct dst_cache *dst_cache);
 172 struct dst_entry *udp_tunnel6_dst_lookup(struct sk_buff *skb,
 173                                          struct net_device *dev,
 174                                          struct net *net,
 175                                          struct socket *sock, int oif,
 176                                          struct in6_addr *saddr,
 177                                          const struct ip_tunnel_key *key,
 178                                          __be16 sport, __be16 dport, u8 dsfield,
 179                                          struct dst_cache *dst_cache);
 180
 181 struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb, unsigned short family,
 182                                     const unsigned long *flags,
 183                                     __be64 tunnel_id, int md_size);
 184
 185 #ifdef CONFIG_INET
 186 static inline int udp_tunnel_handle_offloads(struct sk_buff *skb, bool udp_csum)
 187 {
 188         int type = udp_csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
 189
 190         return iptunnel_handle_offloads(skb, type);
 191 }
 192 #endif
 193
 194 static inline void udp_tunnel_encap_enable(struct sock *sk)
 195 {
 196         if (udp_test_and_set_bit(ENCAP_ENABLED, sk))
 197                 return;
 198
 199 #if IS_ENABLED(CONFIG_IPV6)
 200         if (READ_ONCE(sk->sk_family) == PF_INET6)
 201                 ipv6_stub->udpv6_encap_enable();
 202 #endif
 203         udp_encap_enable();
 204 }
 205
 206 #define UDP_TUNNEL_NIC_MAX_TABLES       4
 207
 208 enum udp_tunnel_nic_info_flags {
 209         /* Device callbacks may sleep */
 210         UDP_TUNNEL_NIC_INFO_MAY_SLEEP   = BIT(0),
 211         /* Device only supports offloads when it's open, all ports
 212          * will be removed before close and re-added after open.
 213          */
 214         UDP_TUNNEL_NIC_INFO_OPEN_ONLY   = BIT(1),
 215         /* Device supports only IPv4 tunnels */
 216         UDP_TUNNEL_NIC_INFO_IPV4_ONLY   = BIT(2),
 217         /* Device has hard-coded the IANA VXLAN port (4789) as VXLAN.
 218          * This port must not be counted towards n_entries of any table.
 219          * Driver will not receive any callback associated with port 4789.
 220          */
 221         UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN   = BIT(3),
 222 };
 223
 224 struct udp_tunnel_nic;
 225
 226 #define UDP_TUNNEL_NIC_MAX_SHARING_DEVICES      (U16_MAX / 2)
 227
 228 struct udp_tunnel_nic_shared {
 229         struct udp_tunnel_nic *udp_tunnel_nic_info;
 230
 231         struct list_head devices;
 232 };
 233
 234 struct udp_tunnel_nic_shared_node {
 235         struct net_device *dev;
 236         struct list_head list;
 237 };
 238
 239 /**
 240  * struct udp_tunnel_nic_info - driver UDP tunnel offload information
 241  * @set_port:   callback for adding a new port
 242  * @unset_port: callback for removing a port
 243  * @sync_table: callback for syncing the entire port table at once
 244  * @shared:     reference to device global state (optional)
 245  * @flags:      device flags from enum udp_tunnel_nic_info_flags
 246  * @tables:     UDP port tables this device has
 247  * @tables.n_entries:           number of entries in this table
 248  * @tables.tunnel_types:        types of tunnels this table accepts
 249  *
 250  * Drivers are expected to provide either @set_port and @unset_port callbacks
 251  * or the @sync_table callback. Callbacks are invoked with rtnl lock held.
 252  *
 253  * Devices which (misguidedly) share the UDP tunnel port table across multiple
 254  * netdevs should allocate an instance of struct udp_tunnel_nic_shared and
 255  * point @shared at it.
 256  * There must never be more than %UDP_TUNNEL_NIC_MAX_SHARING_DEVICES devices
 257  * sharing a table.
 258  *
 259  * Known limitations:
 260  *  - UDP tunnel port notifications are fundamentally best-effort -
 261  *    it is likely the driver will both see skbs which use a UDP tunnel port,
 262  *    while not being a tunneled skb, and tunnel skbs from other ports -
 263  *    drivers should only use these ports for non-critical RX-side offloads,
 264  *    e.g. the checksum offload;
 265  *  - none of the devices care about the socket family at present, so we don't
 266  *    track it. Please extend this code if you care.
 267  */
 268 struct udp_tunnel_nic_info {
 269         /* one-by-one */
 270         int (*set_port)(struct net_device *dev,
 271                         unsigned int table, unsigned int entry,
 272                         struct udp_tunnel_info *ti);
 273         int (*unset_port)(struct net_device *dev,
 274                           unsigned int table, unsigned int entry,
 275                           struct udp_tunnel_info *ti);
 276
 277         /* all at once */
 278         int (*sync_table)(struct net_device *dev, unsigned int table);
 279
 280         struct udp_tunnel_nic_shared *shared;
 281
 282         unsigned int flags;
 283
 284         struct udp_tunnel_nic_table_info {
 285                 unsigned int n_entries;
 286                 unsigned int tunnel_types;
 287         } tables[UDP_TUNNEL_NIC_MAX_TABLES];
 288 };
 289
 290 /* UDP tunnel module dependencies
 291  *
 292  * Tunnel drivers are expected to have a hard dependency on the udp_tunnel
 293  * module. NIC drivers are not, they just attach their
 294  * struct udp_tunnel_nic_info to the netdev and wait for callbacks to come.
 295  * Loading a tunnel driver will cause the udp_tunnel module to be loaded
 296  * and only then will all the required state structures be allocated.
 297  * Since we want a weak dependency from the drivers and the core to udp_tunnel
 298  * we call things through the following stubs.
 299  */
 300 struct udp_tunnel_nic_ops {
 301         void (*get_port)(struct net_device *dev, unsigned int table,
 302                          unsigned int idx, struct udp_tunnel_info *ti);
 303         void (*set_port_priv)(struct net_device *dev, unsigned int table,
 304                               unsigned int idx, u8 priv);
 305         void (*add_port)(struct net_device *dev, struct udp_tunnel_info *ti);
 306         void (*del_port)(struct net_device *dev, struct udp_tunnel_info *ti);
 307         void (*reset_ntf)(struct net_device *dev);
 308
 309         size_t (*dump_size)(struct net_device *dev, unsigned int table);
 310         int (*dump_write)(struct net_device *dev, unsigned int table,
 311                           struct sk_buff *skb);
 312 };
 313
 314 #ifdef CONFIG_INET
 315 extern const struct udp_tunnel_nic_ops *udp_tunnel_nic_ops;
 316 #else
 317 #define udp_tunnel_nic_ops      ((struct udp_tunnel_nic_ops *)NULL)
 318 #endif
 319
 320 static inline void
 321 udp_tunnel_nic_get_port(struct net_device *dev, unsigned int table,
 322                         unsigned int idx, struct udp_tunnel_info *ti)
 323 {
 324         /* This helper is used from .sync_table, we indicate empty entries
 325          * by zero'ed @ti. Drivers which need to know the details of a port
 326          * when it gets deleted should use the .set_port / .unset_port
 327          * callbacks.
 328          * Zero out here, otherwise !CONFIG_INET causes uninitilized warnings.
 329          */
 330         memset(ti, 0, sizeof(*ti));
 331
 332         if (udp_tunnel_nic_ops)
 333                 udp_tunnel_nic_ops->get_port(dev, table, idx, ti);
 334 }
 335
 336 static inline void
 337 udp_tunnel_nic_set_port_priv(struct net_device *dev, unsigned int table,
 338                              unsigned int idx, u8 priv)
 339 {
 340         if (udp_tunnel_nic_ops)
 341                 udp_tunnel_nic_ops->set_port_priv(dev, table, idx, priv);
 342 }
 343
 344 static inline void
 345 udp_tunnel_nic_add_port(struct net_device *dev, struct udp_tunnel_info *ti)
 346 {
 347         if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
 348                 return;
 349         if (udp_tunnel_nic_ops)
 350                 udp_tunnel_nic_ops->add_port(dev, ti);
 351 }
 352
 353 static inline void
 354 udp_tunnel_nic_del_port(struct net_device *dev, struct udp_tunnel_info *ti)
 355 {
 356         if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
 357                 return;
 358         if (udp_tunnel_nic_ops)
 359                 udp_tunnel_nic_ops->del_port(dev, ti);
 360 }
 361
 362 /**
 363  * udp_tunnel_nic_reset_ntf() - device-originating reset notification
 364  * @dev: network interface device structure
 365  *
 366  * Called by the driver to inform the core that the entire UDP tunnel port
 367  * state has been lost, usually due to device reset. Core will assume device
 368  * forgot all the ports and issue .set_port and .sync_table callbacks as
 369  * necessary.
 370  *
 371  * This function must be called with rtnl lock held, and will issue all
 372  * the callbacks before returning.
 373  */
 374 static inline void udp_tunnel_nic_reset_ntf(struct net_device *dev)
 375 {
 376         if (udp_tunnel_nic_ops)
 377                 udp_tunnel_nic_ops->reset_ntf(dev);
 378 }
 379
 380 static inline size_t
 381 udp_tunnel_nic_dump_size(struct net_device *dev, unsigned int table)
 382 {
 383         if (!udp_tunnel_nic_ops)
 384                 return 0;
 385         return udp_tunnel_nic_ops->dump_size(dev, table);
 386 }
 387
 388 static inline int
 389 udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table,
 390                           struct sk_buff *skb)
 391 {
 392         if (!udp_tunnel_nic_ops)
 393                 return 0;
 394         return udp_tunnel_nic_ops->dump_write(dev, table, skb);
 395 }
 396 #endif