LXR linux/include/net/ip

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __NET_IP_TUNNELS_H
   3#define __NET_IP_TUNNELS_H 1
   4
   5#include <linux/if_tunnel.h>
   6#include <linux/netdevice.h>
   7#include <linux/skbuff.h>
   8#include <linux/socket.h>
   9#include <linux/types.h>
  10#include <linux/u64_stats_sync.h>
  11#include <linux/bitops.h>
  12
  13#include <net/dsfield.h>
  14#include <net/gro_cells.h>
  15#include <net/inet_ecn.h>
  16#include <net/netns/generic.h>
  17#include <net/rtnetlink.h>
  18#include <net/lwtunnel.h>
  19#include <net/dst_cache.h>
  20
  21#if IS_ENABLED(CONFIG_IPV6)
  22#include <net/ipv6.h>
  23#include <net/ip6_fib.h>
  24#include <net/ip6_route.h>
  25#endif
  26
  27/* Keep error state on tunnel for 30 sec */
  28#define IPTUNNEL_ERR_TIMEO      (30*HZ)
  29
  30/* Used to memset ip_tunnel padding. */
  31#define IP_TUNNEL_KEY_SIZE      offsetofend(struct ip_tunnel_key, tp_dst)
  32
  33/* Used to memset ipv4 address padding. */
  34#define IP_TUNNEL_KEY_IPV4_PAD  offsetofend(struct ip_tunnel_key, u.ipv4.dst)
  35#define IP_TUNNEL_KEY_IPV4_PAD_LEN                              \
  36        (FIELD_SIZEOF(struct ip_tunnel_key, u) -                \
  37         FIELD_SIZEOF(struct ip_tunnel_key, u.ipv4))
  38
  39struct ip_tunnel_key {
  40        __be64                  tun_id;
  41        union {
  42                struct {
  43                        __be32  src;
  44                        __be32  dst;
  45                } ipv4;
  46                struct {
  47                        struct in6_addr src;
  48                        struct in6_addr dst;
  49                } ipv6;
  50        } u;
  51        __be16                  tun_flags;
  52        u8                      tos;            /* TOS for IPv4, TC for IPv6 */
  53        u8                      ttl;            /* TTL for IPv4, HL for IPv6 */
  54        __be32                  label;          /* Flow Label for IPv6 */
  55        __be16                  tp_src;
  56        __be16                  tp_dst;
  57};
  58
  59/* Flags for ip_tunnel_info mode. */
  60#define IP_TUNNEL_INFO_TX       0x01    /* represents tx tunnel parameters */
  61#define IP_TUNNEL_INFO_IPV6     0x02    /* key contains IPv6 addresses */
  62#define IP_TUNNEL_INFO_BRIDGE   0x04    /* represents a bridged tunnel id */
  63
  64/* Maximum tunnel options length. */
  65#define IP_TUNNEL_OPTS_MAX                                      \
  66        GENMASK((FIELD_SIZEOF(struct ip_tunnel_info,            \
  67                              options_len) * BITS_PER_BYTE) - 1, 0)
  68
  69struct ip_tunnel_info {
  70        struct ip_tunnel_key    key;
  71#ifdef CONFIG_DST_CACHE
  72        struct dst_cache        dst_cache;
  73#endif
  74        u8                      options_len;
  75        u8                      mode;
  76};
  77
  78/* 6rd prefix/relay information */
  79#ifdef CONFIG_IPV6_SIT_6RD
  80struct ip_tunnel_6rd_parm {
  81        struct in6_addr         prefix;
  82        __be32                  relay_prefix;
  83        u16                     prefixlen;
  84        u16                     relay_prefixlen;
  85};
  86#endif
  87
  88struct ip_tunnel_encap {
  89        u16                     type;
  90        u16                     flags;
  91        __be16                  sport;
  92        __be16                  dport;
  93};
  94
  95struct ip_tunnel_prl_entry {
  96        struct ip_tunnel_prl_entry __rcu *next;
  97        __be32                          addr;
  98        u16                             flags;
  99        struct rcu_head                 rcu_head;
 100};
 101
 102struct metadata_dst;
 103
 104struct ip_tunnel {
 105        struct ip_tunnel __rcu  *next;
 106        struct hlist_node hash_node;
 107        struct net_device       *dev;
 108        struct net              *net;   /* netns for packet i/o */
 109
 110        unsigned long   err_time;       /* Time when the last ICMP error
 111                                         * arrived */
 112        int             err_count;      /* Number of arrived ICMP errors */
 113
 114        /* These four fields used only by GRE */
 115        u32             i_seqno;        /* The last seen seqno  */
 116        u32             o_seqno;        /* The last output seqno */
 117        int             tun_hlen;       /* Precalculated header length */
 118
 119        /* These four fields used only by ERSPAN */
 120        u32             index;          /* ERSPAN type II index */
 121        u8              erspan_ver;     /* ERSPAN version */
 122        u8              dir;            /* ERSPAN direction */
 123        u16             hwid;           /* ERSPAN hardware ID */
 124
 125        struct dst_cache dst_cache;
 126
 127        struct ip_tunnel_parm parms;
 128
 129        int             mlink;
 130        int             encap_hlen;     /* Encap header length (FOU,GUE) */
 131        int             hlen;           /* tun_hlen + encap_hlen */
 132        struct ip_tunnel_encap encap;
 133
 134        /* for SIT */
 135#ifdef CONFIG_IPV6_SIT_6RD
 136        struct ip_tunnel_6rd_parm ip6rd;
 137#endif
 138        struct ip_tunnel_prl_entry __rcu *prl;  /* potential router list */
 139        unsigned int            prl_count;      /* # of entries in PRL */
 140        unsigned int            ip_tnl_net_id;
 141        struct gro_cells        gro_cells;
 142        __u32                   fwmark;
 143        bool                    collect_md;
 144        bool                    ignore_df;
 145};
 146
 147struct tnl_ptk_info {
 148        __be16 flags;
 149        __be16 proto;
 150        __be32 key;
 151        __be32 seq;
 152        int hdr_len;
 153};
 154
 155#define PACKET_RCVD     0
 156#define PACKET_REJECT   1
 157#define PACKET_NEXT     2
 158
 159#define IP_TNL_HASH_BITS   7
 160#define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
 161
 162struct ip_tunnel_net {
 163        struct net_device *fb_tunnel_dev;
 164        struct rtnl_link_ops *rtnl_link_ops;
 165        struct hlist_head tunnels[IP_TNL_HASH_SIZE];
 166        struct ip_tunnel __rcu *collect_md_tun;
 167        int type;
 168};
 169
 170static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
 171                                      __be32 saddr, __be32 daddr,
 172                                      u8 tos, u8 ttl, __be32 label,
 173                                      __be16 tp_src, __be16 tp_dst,
 174                                      __be64 tun_id, __be16 tun_flags)
 175{
 176        key->tun_id = tun_id;
 177        key->u.ipv4.src = saddr;
 178        key->u.ipv4.dst = daddr;
 179        memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
 180               0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
 181        key->tos = tos;
 182        key->ttl = ttl;
 183        key->label = label;
 184        key->tun_flags = tun_flags;
 185
 186        /* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
 187         * the upper tunnel are used.
 188         * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
 189         */
 190        key->tp_src = tp_src;
 191        key->tp_dst = tp_dst;
 192
 193        /* Clear struct padding. */
 194        if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
 195                memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
 196                       0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
 197}
 198
 199static inline bool
 200ip_tunnel_dst_cache_usable(const struct sk_buff *skb,
 201                           const struct ip_tunnel_info *info)
 202{
 203        if (skb->mark)
 204                return false;
 205        if (!info)
 206                return true;
 207        if (info->key.tun_flags & TUNNEL_NOCACHE)
 208                return false;
 209
 210        return true;
 211}
 212
 213static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
 214                                               *tun_info)
 215{
 216        return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
 217}
 218
 219static inline __be64 key32_to_tunnel_id(__be32 key)
 220{
 221#ifdef __BIG_ENDIAN
 222        return (__force __be64)key;
 223#else
 224        return (__force __be64)((__force u64)key << 32);
 225#endif
 226}
 227
 228/* Returns the least-significant 32 bits of a __be64. */
 229static inline __be32 tunnel_id_to_key32(__be64 tun_id)
 230{
 231#ifdef __BIG_ENDIAN
 232        return (__force __be32)tun_id;
 233#else
 234        return (__force __be32)((__force u64)tun_id >> 32);
 235#endif
 236}
 237
 238#ifdef CONFIG_INET
 239
 240static inline void ip_tunnel_init_flow(struct flowi4 *fl4,
 241                                       int proto,
 242                                       __be32 daddr, __be32 saddr,
 243                                       __be32 key, __u8 tos, int oif,
 244                                       __u32 mark, __u32 tun_inner_hash)
 245{
 246        memset(fl4, 0, sizeof(*fl4));
 247        fl4->flowi4_oif = oif;
 248        fl4->daddr = daddr;
 249        fl4->saddr = saddr;
 250        fl4->flowi4_tos = tos;
 251        fl4->flowi4_proto = proto;
 252        fl4->fl4_gre_key = key;
 253        fl4->flowi4_mark = mark;
 254        fl4->flowi4_multipath_hash = tun_inner_hash;
 255}
 256
 257int ip_tunnel_init(struct net_device *dev);
 258void ip_tunnel_uninit(struct net_device *dev);
 259void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
 260struct net *ip_tunnel_get_link_net(const struct net_device *dev);
 261int ip_tunnel_get_iflink(const struct net_device *dev);
 262int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
 263                       struct rtnl_link_ops *ops, char *devname);
 264
 265void ip_tunnel_delete_nets(struct list_head *list_net, unsigned int id,
 266                           struct rtnl_link_ops *ops);
 267
 268void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 269                    const struct iphdr *tnl_params, const u8 protocol);
 270void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 271                       const u8 proto, int tunnel_hlen);
 272int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
 273int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
 274int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
 275
 276void ip_tunnel_get_stats64(struct net_device *dev,
 277                           struct rtnl_link_stats64 *tot);
 278struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
 279                                   int link, __be16 flags,
 280                                   __be32 remote, __be32 local,
 281                                   __be32 key);
 282
 283int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
 284                  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
 285                  bool log_ecn_error);
 286int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 287                         struct ip_tunnel_parm *p, __u32 fwmark);
 288int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
 289                      struct ip_tunnel_parm *p, __u32 fwmark);
 290void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
 291
 292struct ip_tunnel_encap_ops {
 293        size_t (*encap_hlen)(struct ip_tunnel_encap *e);
 294        int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
 295                            u8 *protocol, struct flowi4 *fl4);
 296        int (*err_handler)(struct sk_buff *skb, u32 info);
 297};
 298
 299#define MAX_IPTUN_ENCAP_OPS 8
 300
 301extern const struct ip_tunnel_encap_ops __rcu *
 302                iptun_encaps[MAX_IPTUN_ENCAP_OPS];
 303
 304int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
 305                            unsigned int num);
 306int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
 307                            unsigned int num);
 308
 309int ip_tunnel_encap_setup(struct ip_tunnel *t,
 310                          struct ip_tunnel_encap *ipencap);
 311
 312static inline bool pskb_inet_may_pull(struct sk_buff *skb)
 313{
 314        int nhlen;
 315
 316        switch (skb->protocol) {
 317#if IS_ENABLED(CONFIG_IPV6)
 318        case htons(ETH_P_IPV6):
 319                nhlen = sizeof(struct ipv6hdr);
 320                break;
 321#endif
 322        case htons(ETH_P_IP):
 323                nhlen = sizeof(struct iphdr);
 324                break;
 325        default:
 326                nhlen = 0;
 327        }
 328
 329        return pskb_network_may_pull(skb, nhlen);
 330}
 331
 332static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
 333{
 334        const struct ip_tunnel_encap_ops *ops;
 335        int hlen = -EINVAL;
 336
 337        if (e->type == TUNNEL_ENCAP_NONE)
 338                return 0;
 339
 340        if (e->type >= MAX_IPTUN_ENCAP_OPS)
 341                return -EINVAL;
 342
 343        rcu_read_lock();
 344        ops = rcu_dereference(iptun_encaps[e->type]);
 345        if (likely(ops && ops->encap_hlen))
 346                hlen = ops->encap_hlen(e);
 347        rcu_read_unlock();
 348
 349        return hlen;
 350}
 351
 352static inline int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
 353                                  u8 *protocol, struct flowi4 *fl4)
 354{
 355        const struct ip_tunnel_encap_ops *ops;
 356        int ret = -EINVAL;
 357
 358        if (t->encap.type == TUNNEL_ENCAP_NONE)
 359                return 0;
 360
 361        if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
 362                return -EINVAL;
 363
 364        rcu_read_lock();
 365        ops = rcu_dereference(iptun_encaps[t->encap.type]);
 366        if (likely(ops && ops->build_header))
 367                ret = ops->build_header(skb, &t->encap, protocol, fl4);
 368        rcu_read_unlock();
 369
 370        return ret;
 371}
 372
 373/* Extract dsfield from inner protocol */
 374static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
 375                                       const struct sk_buff *skb)
 376{
 377        if (skb->protocol == htons(ETH_P_IP))
 378                return iph->tos;
 379        else if (skb->protocol == htons(ETH_P_IPV6))
 380                return ipv6_get_dsfield((const struct ipv6hdr *)iph);
 381        else
 382                return 0;
 383}
 384
 385static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph,
 386                                       const struct sk_buff *skb)
 387{
 388        if (skb->protocol == htons(ETH_P_IP))
 389                return iph->ttl;
 390        else if (skb->protocol == htons(ETH_P_IPV6))
 391                return ((const struct ipv6hdr *)iph)->hop_limit;
 392        else
 393                return 0;
 394}
 395
 396/* Propogate ECN bits out */
 397static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
 398                                     const struct sk_buff *skb)
 399{
 400        u8 inner = ip_tunnel_get_dsfield(iph, skb);
 401
 402        return INET_ECN_encapsulate(tos, inner);
 403}
 404
 405int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 406                           __be16 inner_proto, bool raw_proto, bool xnet);
 407
 408static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 409                                       __be16 inner_proto, bool xnet)
 410{
 411        return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
 412}
 413
 414void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 415                   __be32 src, __be32 dst, u8 proto,
 416                   u8 tos, u8 ttl, __be16 df, bool xnet);
 417struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 418                                             gfp_t flags);
 419
 420int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
 421
 422static inline int iptunnel_pull_offloads(struct sk_buff *skb)
 423{
 424        if (skb_is_gso(skb)) {
 425                int err;
 426
 427                err = skb_unclone(skb, GFP_ATOMIC);
 428                if (unlikely(err))
 429                        return err;
 430                skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
 431                                               NETIF_F_GSO_SHIFT);
 432        }
 433
 434        skb->encapsulation = 0;
 435        return 0;
 436}
 437
 438static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
 439{
 440        if (pkt_len > 0) {
 441                struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
 442
 443                u64_stats_update_begin(&tstats->syncp);
 444                tstats->tx_bytes += pkt_len;
 445                tstats->tx_packets++;
 446                u64_stats_update_end(&tstats->syncp);
 447                put_cpu_ptr(tstats);
 448        } else {
 449                struct net_device_stats *err_stats = &dev->stats;
 450
 451                if (pkt_len < 0) {
 452                        err_stats->tx_errors++;
 453                        err_stats->tx_aborted_errors++;
 454                } else {
 455                        err_stats->tx_dropped++;
 456                }
 457        }
 458}
 459
 460static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
 461{
 462        return info + 1;
 463}
 464
 465static inline void ip_tunnel_info_opts_get(void *to,
 466                                           const struct ip_tunnel_info *info)
 467{
 468        memcpy(to, info + 1, info->options_len);
 469}
 470
 471static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 472                                           const void *from, int len,
 473                                           __be16 flags)
 474{
 475        memcpy(ip_tunnel_info_opts(info), from, len);
 476        info->options_len = len;
 477        info->key.tun_flags |= flags;
 478}
 479
 480static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 481{
 482        return (struct ip_tunnel_info *)lwtstate->data;
 483}
 484
 485DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
 486
 487/* Returns > 0 if metadata should be collected */
 488static inline int ip_tunnel_collect_metadata(void)
 489{
 490        return static_branch_unlikely(&ip_tunnel_metadata_cnt);
 491}
 492
 493void __init ip_tunnel_core_init(void);
 494
 495void ip_tunnel_need_metadata(void);
 496void ip_tunnel_unneed_metadata(void);
 497
 498#else /* CONFIG_INET */
 499
 500static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 501{
 502        return NULL;
 503}
 504
 505static inline void ip_tunnel_need_metadata(void)
 506{
 507}
 508
 509static inline void ip_tunnel_unneed_metadata(void)
 510{
 511}
 512
 513static inline void ip_tunnel_info_opts_get(void *to,
 514                                           const struct ip_tunnel_info *info)
 515{
 516}
 517
 518static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 519                                           const void *from, int len,
 520                                           __be16 flags)
 521{
 522        info->options_len = 0;
 523        info->key.tun_flags |= flags;
 524}
 525
 526#endif /* CONFIG_INET */
 527
 528#endif /* __NET_IP_TUNNELS_H */
 529