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        (sizeof_field(struct ip_tunnel_key, u) -                \
  37         sizeof_field(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((sizeof_field(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
 108        struct net_device       *dev;
 109        netdevice_tracker       dev_tracker;
 110
 111        struct net              *net;   /* netns for packet i/o */
 112
 113        unsigned long   err_time;       /* Time when the last ICMP error
 114                                         * arrived */
 115        int             err_count;      /* Number of arrived ICMP errors */
 116
 117        /* These four fields used only by GRE */
 118        u32             i_seqno;        /* The last seen seqno  */
 119        atomic_t        o_seqno;        /* The last output seqno */
 120        int             tun_hlen;       /* Precalculated header length */
 121
 122        /* These four fields used only by ERSPAN */
 123        u32             index;          /* ERSPAN type II index */
 124        u8              erspan_ver;     /* ERSPAN version */
 125        u8              dir;            /* ERSPAN direction */
 126        u16             hwid;           /* ERSPAN hardware ID */
 127
 128        struct dst_cache dst_cache;
 129
 130        struct ip_tunnel_parm parms;
 131
 132        int             mlink;
 133        int             encap_hlen;     /* Encap header length (FOU,GUE) */
 134        int             hlen;           /* tun_hlen + encap_hlen */
 135        struct ip_tunnel_encap encap;
 136
 137        /* for SIT */
 138#ifdef CONFIG_IPV6_SIT_6RD
 139        struct ip_tunnel_6rd_parm ip6rd;
 140#endif
 141        struct ip_tunnel_prl_entry __rcu *prl;  /* potential router list */
 142        unsigned int            prl_count;      /* # of entries in PRL */
 143        unsigned int            ip_tnl_net_id;
 144        struct gro_cells        gro_cells;
 145        __u32                   fwmark;
 146        bool                    collect_md;
 147        bool                    ignore_df;
 148};
 149
 150struct tnl_ptk_info {
 151        __be16 flags;
 152        __be16 proto;
 153        __be32 key;
 154        __be32 seq;
 155        int hdr_len;
 156};
 157
 158#define PACKET_RCVD     0
 159#define PACKET_REJECT   1
 160#define PACKET_NEXT     2
 161
 162#define IP_TNL_HASH_BITS   7
 163#define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
 164
 165struct ip_tunnel_net {
 166        struct net_device *fb_tunnel_dev;
 167        struct rtnl_link_ops *rtnl_link_ops;
 168        struct hlist_head tunnels[IP_TNL_HASH_SIZE];
 169        struct ip_tunnel __rcu *collect_md_tun;
 170        int type;
 171};
 172
 173static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
 174                                      __be32 saddr, __be32 daddr,
 175                                      u8 tos, u8 ttl, __be32 label,
 176                                      __be16 tp_src, __be16 tp_dst,
 177                                      __be64 tun_id, __be16 tun_flags)
 178{
 179        key->tun_id = tun_id;
 180        key->u.ipv4.src = saddr;
 181        key->u.ipv4.dst = daddr;
 182        memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
 183               0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
 184        key->tos = tos;
 185        key->ttl = ttl;
 186        key->label = label;
 187        key->tun_flags = tun_flags;
 188
 189        /* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
 190         * the upper tunnel are used.
 191         * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
 192         */
 193        key->tp_src = tp_src;
 194        key->tp_dst = tp_dst;
 195
 196        /* Clear struct padding. */
 197        if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
 198                memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
 199                       0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
 200}
 201
 202static inline bool
 203ip_tunnel_dst_cache_usable(const struct sk_buff *skb,
 204                           const struct ip_tunnel_info *info)
 205{
 206        if (skb->mark)
 207                return false;
 208        if (!info)
 209                return true;
 210        if (info->key.tun_flags & TUNNEL_NOCACHE)
 211                return false;
 212
 213        return true;
 214}
 215
 216static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
 217                                               *tun_info)
 218{
 219        return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
 220}
 221
 222static inline __be64 key32_to_tunnel_id(__be32 key)
 223{
 224#ifdef __BIG_ENDIAN
 225        return (__force __be64)key;
 226#else
 227        return (__force __be64)((__force u64)key << 32);
 228#endif
 229}
 230
 231/* Returns the least-significant 32 bits of a __be64. */
 232static inline __be32 tunnel_id_to_key32(__be64 tun_id)
 233{
 234#ifdef __BIG_ENDIAN
 235        return (__force __be32)tun_id;
 236#else
 237        return (__force __be32)((__force u64)tun_id >> 32);
 238#endif
 239}
 240
 241#ifdef CONFIG_INET
 242
 243static inline void ip_tunnel_init_flow(struct flowi4 *fl4,
 244                                       int proto,
 245                                       __be32 daddr, __be32 saddr,
 246                                       __be32 key, __u8 tos,
 247                                       struct net *net, int oif,
 248                                       __u32 mark, __u32 tun_inner_hash)
 249{
 250        memset(fl4, 0, sizeof(*fl4));
 251
 252        if (oif) {
 253                fl4->flowi4_l3mdev = l3mdev_master_upper_ifindex_by_index_rcu(net, oif);
 254                /* Legacy VRF/l3mdev use case */
 255                fl4->flowi4_oif = fl4->flowi4_l3mdev ? 0 : oif;
 256        }
 257
 258        fl4->daddr = daddr;
 259        fl4->saddr = saddr;
 260        fl4->flowi4_tos = tos;
 261        fl4->flowi4_proto = proto;
 262        fl4->fl4_gre_key = key;
 263        fl4->flowi4_mark = mark;
 264        fl4->flowi4_multipath_hash = tun_inner_hash;
 265}
 266
 267int ip_tunnel_init(struct net_device *dev);
 268void ip_tunnel_uninit(struct net_device *dev);
 269void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
 270struct net *ip_tunnel_get_link_net(const struct net_device *dev);
 271int ip_tunnel_get_iflink(const struct net_device *dev);
 272int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
 273                       struct rtnl_link_ops *ops, char *devname);
 274
 275void ip_tunnel_delete_nets(struct list_head *list_net, unsigned int id,
 276                           struct rtnl_link_ops *ops);
 277
 278void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 279                    const struct iphdr *tnl_params, const u8 protocol);
 280void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 281                       const u8 proto, int tunnel_hlen);
 282int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
 283int ip_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
 284                             void __user *data, int cmd);
 285int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
 286int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
 287
 288struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
 289                                   int link, __be16 flags,
 290                                   __be32 remote, __be32 local,
 291                                   __be32 key);
 292
 293int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
 294                  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
 295                  bool log_ecn_error);
 296int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 297                         struct ip_tunnel_parm *p, __u32 fwmark);
 298int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
 299                      struct ip_tunnel_parm *p, __u32 fwmark);
 300void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
 301
 302extern const struct header_ops ip_tunnel_header_ops;
 303__be16 ip_tunnel_parse_protocol(const struct sk_buff *skb);
 304
 305struct ip_tunnel_encap_ops {
 306        size_t (*encap_hlen)(struct ip_tunnel_encap *e);
 307        int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
 308                            u8 *protocol, struct flowi4 *fl4);
 309        int (*err_handler)(struct sk_buff *skb, u32 info);
 310};
 311
 312#define MAX_IPTUN_ENCAP_OPS 8
 313
 314extern const struct ip_tunnel_encap_ops __rcu *
 315                iptun_encaps[MAX_IPTUN_ENCAP_OPS];
 316
 317int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
 318                            unsigned int num);
 319int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
 320                            unsigned int num);
 321
 322int ip_tunnel_encap_setup(struct ip_tunnel *t,
 323                          struct ip_tunnel_encap *ipencap);
 324
 325static inline bool pskb_inet_may_pull(struct sk_buff *skb)
 326{
 327        int nhlen;
 328
 329        switch (skb->protocol) {
 330#if IS_ENABLED(CONFIG_IPV6)
 331        case htons(ETH_P_IPV6):
 332                nhlen = sizeof(struct ipv6hdr);
 333                break;
 334#endif
 335        case htons(ETH_P_IP):
 336                nhlen = sizeof(struct iphdr);
 337                break;
 338        default:
 339                nhlen = 0;
 340        }
 341
 342        return pskb_network_may_pull(skb, nhlen);
 343}
 344
 345static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
 346{
 347        const struct ip_tunnel_encap_ops *ops;
 348        int hlen = -EINVAL;
 349
 350        if (e->type == TUNNEL_ENCAP_NONE)
 351                return 0;
 352
 353        if (e->type >= MAX_IPTUN_ENCAP_OPS)
 354                return -EINVAL;
 355
 356        rcu_read_lock();
 357        ops = rcu_dereference(iptun_encaps[e->type]);
 358        if (likely(ops && ops->encap_hlen))
 359                hlen = ops->encap_hlen(e);
 360        rcu_read_unlock();
 361
 362        return hlen;
 363}
 364
 365static inline int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
 366                                  u8 *protocol, struct flowi4 *fl4)
 367{
 368        const struct ip_tunnel_encap_ops *ops;
 369        int ret = -EINVAL;
 370
 371        if (t->encap.type == TUNNEL_ENCAP_NONE)
 372                return 0;
 373
 374        if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
 375                return -EINVAL;
 376
 377        rcu_read_lock();
 378        ops = rcu_dereference(iptun_encaps[t->encap.type]);
 379        if (likely(ops && ops->build_header))
 380                ret = ops->build_header(skb, &t->encap, protocol, fl4);
 381        rcu_read_unlock();
 382
 383        return ret;
 384}
 385
 386/* Extract dsfield from inner protocol */
 387static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
 388                                       const struct sk_buff *skb)
 389{
 390        if (skb->protocol == htons(ETH_P_IP))
 391                return iph->tos;
 392        else if (skb->protocol == htons(ETH_P_IPV6))
 393                return ipv6_get_dsfield((const struct ipv6hdr *)iph);
 394        else
 395                return 0;
 396}
 397
 398static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph,
 399                                       const struct sk_buff *skb)
 400{
 401        if (skb->protocol == htons(ETH_P_IP))
 402                return iph->ttl;
 403        else if (skb->protocol == htons(ETH_P_IPV6))
 404                return ((const struct ipv6hdr *)iph)->hop_limit;
 405        else
 406                return 0;
 407}
 408
 409/* Propogate ECN bits out */
 410static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
 411                                     const struct sk_buff *skb)
 412{
 413        u8 inner = ip_tunnel_get_dsfield(iph, skb);
 414
 415        return INET_ECN_encapsulate(tos, inner);
 416}
 417
 418int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 419                           __be16 inner_proto, bool raw_proto, bool xnet);
 420
 421static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 422                                       __be16 inner_proto, bool xnet)
 423{
 424        return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
 425}
 426
 427void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 428                   __be32 src, __be32 dst, u8 proto,
 429                   u8 tos, u8 ttl, __be16 df, bool xnet);
 430struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 431                                             gfp_t flags);
 432int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst,
 433                          int headroom, bool reply);
 434
 435int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
 436
 437static inline int iptunnel_pull_offloads(struct sk_buff *skb)
 438{
 439        if (skb_is_gso(skb)) {
 440                int err;
 441
 442                err = skb_unclone(skb, GFP_ATOMIC);
 443                if (unlikely(err))
 444                        return err;
 445                skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
 446                                               NETIF_F_GSO_SHIFT);
 447        }
 448
 449        skb->encapsulation = 0;
 450        return 0;
 451}
 452
 453static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
 454{
 455        if (pkt_len > 0) {
 456                struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
 457
 458                u64_stats_update_begin(&tstats->syncp);
 459                tstats->tx_bytes += pkt_len;
 460                tstats->tx_packets++;
 461                u64_stats_update_end(&tstats->syncp);
 462                put_cpu_ptr(tstats);
 463        } else {
 464                struct net_device_stats *err_stats = &dev->stats;
 465
 466                if (pkt_len < 0) {
 467                        err_stats->tx_errors++;
 468                        err_stats->tx_aborted_errors++;
 469                } else {
 470                        err_stats->tx_dropped++;
 471                }
 472        }
 473}
 474
 475static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
 476{
 477        return info + 1;
 478}
 479
 480static inline void ip_tunnel_info_opts_get(void *to,
 481                                           const struct ip_tunnel_info *info)
 482{
 483        memcpy(to, info + 1, info->options_len);
 484}
 485
 486static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 487                                           const void *from, int len,
 488                                           __be16 flags)
 489{
 490        info->options_len = len;
 491        if (len > 0) {
 492                memcpy(ip_tunnel_info_opts(info), from, len);
 493                info->key.tun_flags |= flags;
 494        }
 495}
 496
 497static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 498{
 499        return (struct ip_tunnel_info *)lwtstate->data;
 500}
 501
 502DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
 503
 504/* Returns > 0 if metadata should be collected */
 505static inline int ip_tunnel_collect_metadata(void)
 506{
 507        return static_branch_unlikely(&ip_tunnel_metadata_cnt);
 508}
 509
 510void __init ip_tunnel_core_init(void);
 511
 512void ip_tunnel_need_metadata(void);
 513void ip_tunnel_unneed_metadata(void);
 514
 515#else /* CONFIG_INET */
 516
 517static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 518{
 519        return NULL;
 520}
 521
 522static inline void ip_tunnel_need_metadata(void)
 523{
 524}
 525
 526static inline void ip_tunnel_unneed_metadata(void)
 527{
 528}
 529
 530static inline void ip_tunnel_info_opts_get(void *to,
 531                                           const struct ip_tunnel_info *info)
 532{
 533}
 534
 535static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 536                                           const void *from, int len,
 537                                           __be16 flags)
 538{
 539        info->options_len = 0;
 540}
 541
 542#endif /* CONFIG_INET */
 543
 544#endif /* __NET_IP_TUNNELS_H */
 545