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