include/net/ip_tunnels.h

   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
  38 struct 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
  67 struct 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
  78 struct ip_tunnel_6rd_parm {
  79         struct in6_addr         prefix;
  80         __be32                  relay_prefix;
  81         u16                     prefixlen;
  82         u16                     relay_prefixlen;
  83 };
  84 #endif
  85
  86 struct ip_tunnel_encap {
  87         u16                     type;
  88         u16                     flags;
  89         __be16                  sport;
  90         __be16                  dport;
  91 };
  92
  93 struct 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
 100 struct metadata_dst;
 101
 102 struct 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         unsigned 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
 155 struct 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
 170 struct 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
 176 static 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
 205 static inline bool
 206 ip_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
 219 static 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
 225 static 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. */
 235 static 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
 246 int ip_tunnel_init(struct net_device *dev);
 247 void ip_tunnel_uninit(struct net_device *dev);
 248 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
 249 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
 250 int ip_tunnel_get_iflink(const struct net_device *dev);
 251 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
 252                        struct rtnl_link_ops *ops, char *devname);
 253
 254 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
 255
 256 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 257                     const struct iphdr *tnl_params, const u8 protocol);
 258 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 259                        const u8 proto);
 260 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
 261 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
 262 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
 263
 264 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
 265                                                 struct rtnl_link_stats64 *tot);
 266 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
 267                                    int link, __be16 flags,
 268                                    __be32 remote, __be32 local,
 269                                    __be32 key);
 270
 271 int 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);
 274 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 275                          struct ip_tunnel_parm *p);
 276 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
 277                       struct ip_tunnel_parm *p);
 278 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
 279
 280 struct 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
 288 extern const struct ip_tunnel_encap_ops __rcu *
 289                 iptun_encaps[MAX_IPTUN_ENCAP_OPS];
 290
 291 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
 292                             unsigned int num);
 293 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
 294                             unsigned int num);
 295
 296 int ip_tunnel_encap_setup(struct ip_tunnel *t,
 297                           struct ip_tunnel_encap *ipencap);
 298
 299 static 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
 319 static 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 */
 341 static 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 */
 353 static 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
 361 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 362                            __be16 inner_proto, bool raw_proto, bool xnet);
 363
 364 static 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
 370 void 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);
 373 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 374                                              gfp_t flags);
 375
 376 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
 377
 378 static 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
 394 static 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
 416 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
 417 {
 418         return info + 1;
 419 }
 420
 421 static 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
 427 static 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
 434 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 435 {
 436         return (struct ip_tunnel_info *)lwtstate->data;
 437 }
 438
 439 extern struct static_key ip_tunnel_metadata_cnt;
 440
 441 /* Returns > 0 if metadata should be collected */
 442 static inline int ip_tunnel_collect_metadata(void)
 443 {
 444         return static_key_false(&ip_tunnel_metadata_cnt);
 445 }
 446
 447 void __init ip_tunnel_core_init(void);
 448
 449 void ip_tunnel_need_metadata(void);
 450 void ip_tunnel_unneed_metadata(void);
 451
 452 #else /* CONFIG_INET */
 453
 454 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 455 {
 456         return NULL;
 457 }
 458
 459 static inline void ip_tunnel_need_metadata(void)
 460 {
 461 }
 462
 463 static inline void ip_tunnel_unneed_metadata(void)
 464 {
 465 }
 466
 467 static inline void ip_tunnel_info_opts_get(void *to,
 468                                            const struct ip_tunnel_info *info)
 469 {
 470 }
 471
 472 static 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 */