linux/include/net/ip_tunnels.h
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   1#ifndef __NET_IP_TUNNELS_H
   2#define __NET_IP_TUNNELS_H 1
   3
   4#include <linux/if_tunnel.h>
   5#include <linux/netdevice.h>
   6#include <linux/skbuff.h>
   7#include <linux/socket.h>
   8#include <linux/types.h>
   9#include <linux/u64_stats_sync.h>
  10#include <linux/bitops.h>
  11
  12#include <net/dsfield.h>
  13#include <net/gro_cells.h>
  14#include <net/inet_ecn.h>
  15#include <net/netns/generic.h>
  16#include <net/rtnetlink.h>
  17#include <net/lwtunnel.h>
  18#include <net/dst_cache.h>
  19
  20#if IS_ENABLED(CONFIG_IPV6)
  21#include <net/ipv6.h>
  22#include <net/ip6_fib.h>
  23#include <net/ip6_route.h>
  24#endif
  25
  26/* Keep error state on tunnel for 30 sec */
  27#define IPTUNNEL_ERR_TIMEO      (30*HZ)
  28
  29/* Used to memset ip_tunnel padding. */
  30#define IP_TUNNEL_KEY_SIZE      offsetofend(struct ip_tunnel_key, tp_dst)
  31
  32/* Used to memset ipv4 address padding. */
  33#define IP_TUNNEL_KEY_IPV4_PAD  offsetofend(struct ip_tunnel_key, u.ipv4.dst)
  34#define IP_TUNNEL_KEY_IPV4_PAD_LEN                              \
  35        (FIELD_SIZEOF(struct ip_tunnel_key, u) -                \
  36         FIELD_SIZEOF(struct ip_tunnel_key, u.ipv4))
  37
  38struct ip_tunnel_key {
  39        __be64                  tun_id;
  40        union {
  41                struct {
  42                        __be32  src;
  43                        __be32  dst;
  44                } ipv4;
  45                struct {
  46                        struct in6_addr src;
  47                        struct in6_addr dst;
  48                } ipv6;
  49        } u;
  50        __be16                  tun_flags;
  51        u8                      tos;            /* TOS for IPv4, TC for IPv6 */
  52        u8                      ttl;            /* TTL for IPv4, HL for IPv6 */
  53        __be32                  label;          /* Flow Label for IPv6 */
  54        __be16                  tp_src;
  55        __be16                  tp_dst;
  56};
  57
  58/* Flags for ip_tunnel_info mode. */
  59#define IP_TUNNEL_INFO_TX       0x01    /* represents tx tunnel parameters */
  60#define IP_TUNNEL_INFO_IPV6     0x02    /* key contains IPv6 addresses */
  61
  62/* Maximum tunnel options length. */
  63#define IP_TUNNEL_OPTS_MAX                                      \
  64        GENMASK((FIELD_SIZEOF(struct ip_tunnel_info,            \
  65                              options_len) * BITS_PER_BYTE) - 1, 0)
  66
  67struct ip_tunnel_info {
  68        struct ip_tunnel_key    key;
  69#ifdef CONFIG_DST_CACHE
  70        struct dst_cache        dst_cache;
  71#endif
  72        u8                      options_len;
  73        u8                      mode;
  74};
  75
  76/* 6rd prefix/relay information */
  77#ifdef CONFIG_IPV6_SIT_6RD
  78struct ip_tunnel_6rd_parm {
  79        struct in6_addr         prefix;
  80        __be32                  relay_prefix;
  81        u16                     prefixlen;
  82        u16                     relay_prefixlen;
  83};
  84#endif
  85
  86struct ip_tunnel_encap {
  87        u16                     type;
  88        u16                     flags;
  89        __be16                  sport;
  90        __be16                  dport;
  91};
  92
  93struct ip_tunnel_prl_entry {
  94        struct ip_tunnel_prl_entry __rcu *next;
  95        __be32                          addr;
  96        u16                             flags;
  97        struct rcu_head                 rcu_head;
  98};
  99
 100struct metadata_dst;
 101
 102struct ip_tunnel {
 103        struct ip_tunnel __rcu  *next;
 104        struct hlist_node hash_node;
 105        struct net_device       *dev;
 106        struct net              *net;   /* netns for packet i/o */
 107
 108        unsigned long   err_time;       /* Time when the last ICMP error
 109                                         * arrived */
 110        int             err_count;      /* Number of arrived ICMP errors */
 111
 112        /* These four fields used only by GRE */
 113        u32             i_seqno;        /* The last seen seqno  */
 114        u32             o_seqno;        /* The last output seqno */
 115        int             tun_hlen;       /* Precalculated header length */
 116
 117        struct dst_cache dst_cache;
 118
 119        struct ip_tunnel_parm parms;
 120
 121        int             mlink;
 122        int             encap_hlen;     /* Encap header length (FOU,GUE) */
 123        int             hlen;           /* tun_hlen + encap_hlen */
 124        struct ip_tunnel_encap encap;
 125
 126        /* for SIT */
 127#ifdef CONFIG_IPV6_SIT_6RD
 128        struct ip_tunnel_6rd_parm ip6rd;
 129#endif
 130        struct ip_tunnel_prl_entry __rcu *prl;  /* potential router list */
 131        unsigned int            prl_count;      /* # of entries in PRL */
 132        int                     ip_tnl_net_id;
 133        struct gro_cells        gro_cells;
 134        bool                    collect_md;
 135        bool                    ignore_df;
 136};
 137
 138#define TUNNEL_CSUM             __cpu_to_be16(0x01)
 139#define TUNNEL_ROUTING          __cpu_to_be16(0x02)
 140#define TUNNEL_KEY              __cpu_to_be16(0x04)
 141#define TUNNEL_SEQ              __cpu_to_be16(0x08)
 142#define TUNNEL_STRICT           __cpu_to_be16(0x10)
 143#define TUNNEL_REC              __cpu_to_be16(0x20)
 144#define TUNNEL_VERSION          __cpu_to_be16(0x40)
 145#define TUNNEL_NO_KEY           __cpu_to_be16(0x80)
 146#define TUNNEL_DONT_FRAGMENT    __cpu_to_be16(0x0100)
 147#define TUNNEL_OAM              __cpu_to_be16(0x0200)
 148#define TUNNEL_CRIT_OPT         __cpu_to_be16(0x0400)
 149#define TUNNEL_GENEVE_OPT       __cpu_to_be16(0x0800)
 150#define TUNNEL_VXLAN_OPT        __cpu_to_be16(0x1000)
 151#define TUNNEL_NOCACHE          __cpu_to_be16(0x2000)
 152
 153#define TUNNEL_OPTIONS_PRESENT  (TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT)
 154
 155struct tnl_ptk_info {
 156        __be16 flags;
 157        __be16 proto;
 158        __be32 key;
 159        __be32 seq;
 160        int hdr_len;
 161};
 162
 163#define PACKET_RCVD     0
 164#define PACKET_REJECT   1
 165#define PACKET_NEXT     2
 166
 167#define IP_TNL_HASH_BITS   7
 168#define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
 169
 170struct ip_tunnel_net {
 171        struct net_device *fb_tunnel_dev;
 172        struct hlist_head tunnels[IP_TNL_HASH_SIZE];
 173        struct ip_tunnel __rcu *collect_md_tun;
 174};
 175
 176static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
 177                                      __be32 saddr, __be32 daddr,
 178                                      u8 tos, u8 ttl, __be32 label,
 179                                      __be16 tp_src, __be16 tp_dst,
 180                                      __be64 tun_id, __be16 tun_flags)
 181{
 182        key->tun_id = tun_id;
 183        key->u.ipv4.src = saddr;
 184        key->u.ipv4.dst = daddr;
 185        memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
 186               0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
 187        key->tos = tos;
 188        key->ttl = ttl;
 189        key->label = label;
 190        key->tun_flags = tun_flags;
 191
 192        /* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
 193         * the upper tunnel are used.
 194         * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
 195         */
 196        key->tp_src = tp_src;
 197        key->tp_dst = tp_dst;
 198
 199        /* Clear struct padding. */
 200        if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
 201                memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
 202                       0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
 203}
 204
 205static inline bool
 206ip_tunnel_dst_cache_usable(const struct sk_buff *skb,
 207                           const struct ip_tunnel_info *info)
 208{
 209        if (skb->mark)
 210                return false;
 211        if (!info)
 212                return true;
 213        if (info->key.tun_flags & TUNNEL_NOCACHE)
 214                return false;
 215
 216        return true;
 217}
 218
 219static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
 220                                               *tun_info)
 221{
 222        return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
 223}
 224
 225static inline __be64 key32_to_tunnel_id(__be32 key)
 226{
 227#ifdef __BIG_ENDIAN
 228        return (__force __be64)key;
 229#else
 230        return (__force __be64)((__force u64)key << 32);
 231#endif
 232}
 233
 234/* Returns the least-significant 32 bits of a __be64. */
 235static inline __be32 tunnel_id_to_key32(__be64 tun_id)
 236{
 237#ifdef __BIG_ENDIAN
 238        return (__force __be32)tun_id;
 239#else
 240        return (__force __be32)((__force u64)tun_id >> 32);
 241#endif
 242}
 243
 244#ifdef CONFIG_INET
 245
 246int ip_tunnel_init(struct net_device *dev);
 247void ip_tunnel_uninit(struct net_device *dev);
 248void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
 249struct net *ip_tunnel_get_link_net(const struct net_device *dev);
 250int ip_tunnel_get_iflink(const struct net_device *dev);
 251int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
 252                       struct rtnl_link_ops *ops, char *devname);
 253
 254void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
 255
 256void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 257                    const struct iphdr *tnl_params, const u8 protocol);
 258void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 259                       const u8 proto);
 260int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
 261int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
 262int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
 263
 264struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
 265                                                struct rtnl_link_stats64 *tot);
 266struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
 267                                   int link, __be16 flags,
 268                                   __be32 remote, __be32 local,
 269                                   __be32 key);
 270
 271int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
 272                  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
 273                  bool log_ecn_error);
 274int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 275                         struct ip_tunnel_parm *p);
 276int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
 277                      struct ip_tunnel_parm *p);
 278void ip_tunnel_setup(struct net_device *dev, int net_id);
 279
 280struct ip_tunnel_encap_ops {
 281        size_t (*encap_hlen)(struct ip_tunnel_encap *e);
 282        int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
 283                            u8 *protocol, struct flowi4 *fl4);
 284};
 285
 286#define MAX_IPTUN_ENCAP_OPS 8
 287
 288extern const struct ip_tunnel_encap_ops __rcu *
 289                iptun_encaps[MAX_IPTUN_ENCAP_OPS];
 290
 291int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
 292                            unsigned int num);
 293int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
 294                            unsigned int num);
 295
 296int ip_tunnel_encap_setup(struct ip_tunnel *t,
 297                          struct ip_tunnel_encap *ipencap);
 298
 299static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
 300{
 301        const struct ip_tunnel_encap_ops *ops;
 302        int hlen = -EINVAL;
 303
 304        if (e->type == TUNNEL_ENCAP_NONE)
 305                return 0;
 306
 307        if (e->type >= MAX_IPTUN_ENCAP_OPS)
 308                return -EINVAL;
 309
 310        rcu_read_lock();
 311        ops = rcu_dereference(iptun_encaps[e->type]);
 312        if (likely(ops && ops->encap_hlen))
 313                hlen = ops->encap_hlen(e);
 314        rcu_read_unlock();
 315
 316        return hlen;
 317}
 318
 319static inline int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
 320                                  u8 *protocol, struct flowi4 *fl4)
 321{
 322        const struct ip_tunnel_encap_ops *ops;
 323        int ret = -EINVAL;
 324
 325        if (t->encap.type == TUNNEL_ENCAP_NONE)
 326                return 0;
 327
 328        if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
 329                return -EINVAL;
 330
 331        rcu_read_lock();
 332        ops = rcu_dereference(iptun_encaps[t->encap.type]);
 333        if (likely(ops && ops->build_header))
 334                ret = ops->build_header(skb, &t->encap, protocol, fl4);
 335        rcu_read_unlock();
 336
 337        return ret;
 338}
 339
 340/* Extract dsfield from inner protocol */
 341static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
 342                                       const struct sk_buff *skb)
 343{
 344        if (skb->protocol == htons(ETH_P_IP))
 345                return iph->tos;
 346        else if (skb->protocol == htons(ETH_P_IPV6))
 347                return ipv6_get_dsfield((const struct ipv6hdr *)iph);
 348        else
 349                return 0;
 350}
 351
 352/* Propogate ECN bits out */
 353static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
 354                                     const struct sk_buff *skb)
 355{
 356        u8 inner = ip_tunnel_get_dsfield(iph, skb);
 357
 358        return INET_ECN_encapsulate(tos, inner);
 359}
 360
 361int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 362                           __be16 inner_proto, bool raw_proto, bool xnet);
 363
 364static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 365                                       __be16 inner_proto, bool xnet)
 366{
 367        return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
 368}
 369
 370void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 371                   __be32 src, __be32 dst, u8 proto,
 372                   u8 tos, u8 ttl, __be16 df, bool xnet);
 373struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 374                                             gfp_t flags);
 375
 376int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
 377
 378static inline int iptunnel_pull_offloads(struct sk_buff *skb)
 379{
 380        if (skb_is_gso(skb)) {
 381                int err;
 382
 383                err = skb_unclone(skb, GFP_ATOMIC);
 384                if (unlikely(err))
 385                        return err;
 386                skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
 387                                               NETIF_F_GSO_SHIFT);
 388        }
 389
 390        skb->encapsulation = 0;
 391        return 0;
 392}
 393
 394static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
 395{
 396        if (pkt_len > 0) {
 397                struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
 398
 399                u64_stats_update_begin(&tstats->syncp);
 400                tstats->tx_bytes += pkt_len;
 401                tstats->tx_packets++;
 402                u64_stats_update_end(&tstats->syncp);
 403                put_cpu_ptr(tstats);
 404        } else {
 405                struct net_device_stats *err_stats = &dev->stats;
 406
 407                if (pkt_len < 0) {
 408                        err_stats->tx_errors++;
 409                        err_stats->tx_aborted_errors++;
 410                } else {
 411                        err_stats->tx_dropped++;
 412                }
 413        }
 414}
 415
 416static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
 417{
 418        return info + 1;
 419}
 420
 421static inline void ip_tunnel_info_opts_get(void *to,
 422                                           const struct ip_tunnel_info *info)
 423{
 424        memcpy(to, info + 1, info->options_len);
 425}
 426
 427static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 428                                           const void *from, int len)
 429{
 430        memcpy(ip_tunnel_info_opts(info), from, len);
 431        info->options_len = len;
 432}
 433
 434static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 435{
 436        return (struct ip_tunnel_info *)lwtstate->data;
 437}
 438
 439extern struct static_key ip_tunnel_metadata_cnt;
 440
 441/* Returns > 0 if metadata should be collected */
 442static inline int ip_tunnel_collect_metadata(void)
 443{
 444        return static_key_false(&ip_tunnel_metadata_cnt);
 445}
 446
 447void __init ip_tunnel_core_init(void);
 448
 449void ip_tunnel_need_metadata(void);
 450void ip_tunnel_unneed_metadata(void);
 451
 452#else /* CONFIG_INET */
 453
 454static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 455{
 456        return NULL;
 457}
 458
 459static inline void ip_tunnel_need_metadata(void)
 460{
 461}
 462
 463static inline void ip_tunnel_unneed_metadata(void)
 464{
 465}
 466
 467static inline void ip_tunnel_info_opts_get(void *to,
 468                                           const struct ip_tunnel_info *info)
 469{
 470}
 471
 472static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 473                                           const void *from, int len)
 474{
 475        info->options_len = 0;
 476}
 477
 478#endif /* CONFIG_INET */
 479
 480#endif /* __NET_IP_TUNNELS_H */
 481