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         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 #ifdef CONFIG_INET
 226
 227 int ip_tunnel_init(struct net_device *dev);
 228 void ip_tunnel_uninit(struct net_device *dev);
 229 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
 230 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
 231 int ip_tunnel_get_iflink(const struct net_device *dev);
 232 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
 233                        struct rtnl_link_ops *ops, char *devname);
 234
 235 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
 236
 237 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 238                     const struct iphdr *tnl_params, const u8 protocol);
 239 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
 240 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
 241 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
 242
 243 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
 244                                                 struct rtnl_link_stats64 *tot);
 245 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
 246                                    int link, __be16 flags,
 247                                    __be32 remote, __be32 local,
 248                                    __be32 key);
 249
 250 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
 251                   const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
 252                   bool log_ecn_error);
 253 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 254                          struct ip_tunnel_parm *p);
 255 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
 256                       struct ip_tunnel_parm *p);
 257 void ip_tunnel_setup(struct net_device *dev, int net_id);
 258
 259 struct ip_tunnel_encap_ops {
 260         size_t (*encap_hlen)(struct ip_tunnel_encap *e);
 261         int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
 262                             u8 *protocol, struct flowi4 *fl4);
 263 };
 264
 265 #define MAX_IPTUN_ENCAP_OPS 8
 266
 267 extern const struct ip_tunnel_encap_ops __rcu *
 268                 iptun_encaps[MAX_IPTUN_ENCAP_OPS];
 269
 270 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
 271                             unsigned int num);
 272 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
 273                             unsigned int num);
 274
 275 int ip_tunnel_encap_setup(struct ip_tunnel *t,
 276                           struct ip_tunnel_encap *ipencap);
 277
 278 static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
 279 {
 280         const struct ip_tunnel_encap_ops *ops;
 281         int hlen = -EINVAL;
 282
 283         if (e->type == TUNNEL_ENCAP_NONE)
 284                 return 0;
 285
 286         if (e->type >= MAX_IPTUN_ENCAP_OPS)
 287                 return -EINVAL;
 288
 289         rcu_read_lock();
 290         ops = rcu_dereference(iptun_encaps[e->type]);
 291         if (likely(ops && ops->encap_hlen))
 292                 hlen = ops->encap_hlen(e);
 293         rcu_read_unlock();
 294
 295         return hlen;
 296 }
 297
 298 static inline int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
 299                                   u8 *protocol, struct flowi4 *fl4)
 300 {
 301         const struct ip_tunnel_encap_ops *ops;
 302         int ret = -EINVAL;
 303
 304         if (t->encap.type == TUNNEL_ENCAP_NONE)
 305                 return 0;
 306
 307         if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
 308                 return -EINVAL;
 309
 310         rcu_read_lock();
 311         ops = rcu_dereference(iptun_encaps[t->encap.type]);
 312         if (likely(ops && ops->build_header))
 313                 ret = ops->build_header(skb, &t->encap, protocol, fl4);
 314         rcu_read_unlock();
 315
 316         return ret;
 317 }
 318
 319 /* Extract dsfield from inner protocol */
 320 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
 321                                        const struct sk_buff *skb)
 322 {
 323         if (skb->protocol == htons(ETH_P_IP))
 324                 return iph->tos;
 325         else if (skb->protocol == htons(ETH_P_IPV6))
 326                 return ipv6_get_dsfield((const struct ipv6hdr *)iph);
 327         else
 328                 return 0;
 329 }
 330
 331 /* Propogate ECN bits out */
 332 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
 333                                      const struct sk_buff *skb)
 334 {
 335         u8 inner = ip_tunnel_get_dsfield(iph, skb);
 336
 337         return INET_ECN_encapsulate(tos, inner);
 338 }
 339
 340 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 341                            __be16 inner_proto, bool raw_proto, bool xnet);
 342
 343 static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 344                                        __be16 inner_proto, bool xnet)
 345 {
 346         return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
 347 }
 348
 349 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 350                    __be32 src, __be32 dst, u8 proto,
 351                    u8 tos, u8 ttl, __be16 df, bool xnet);
 352 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 353                                              gfp_t flags);
 354
 355 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
 356
 357 static inline int iptunnel_pull_offloads(struct sk_buff *skb)
 358 {
 359         if (skb_is_gso(skb)) {
 360                 int err;
 361
 362                 err = skb_unclone(skb, GFP_ATOMIC);
 363                 if (unlikely(err))
 364                         return err;
 365                 skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
 366                                                NETIF_F_GSO_SHIFT);
 367         }
 368
 369         skb->encapsulation = 0;
 370         return 0;
 371 }
 372
 373 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
 374 {
 375         if (pkt_len > 0) {
 376                 struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
 377
 378                 u64_stats_update_begin(&tstats->syncp);
 379                 tstats->tx_bytes += pkt_len;
 380                 tstats->tx_packets++;
 381                 u64_stats_update_end(&tstats->syncp);
 382                 put_cpu_ptr(tstats);
 383         } else {
 384                 struct net_device_stats *err_stats = &dev->stats;
 385
 386                 if (pkt_len < 0) {
 387                         err_stats->tx_errors++;
 388                         err_stats->tx_aborted_errors++;
 389                 } else {
 390                         err_stats->tx_dropped++;
 391                 }
 392         }
 393 }
 394
 395 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
 396 {
 397         return info + 1;
 398 }
 399
 400 static inline void ip_tunnel_info_opts_get(void *to,
 401                                            const struct ip_tunnel_info *info)
 402 {
 403         memcpy(to, info + 1, info->options_len);
 404 }
 405
 406 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 407                                            const void *from, int len)
 408 {
 409         memcpy(ip_tunnel_info_opts(info), from, len);
 410         info->options_len = len;
 411 }
 412
 413 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 414 {
 415         return (struct ip_tunnel_info *)lwtstate->data;
 416 }
 417
 418 extern struct static_key ip_tunnel_metadata_cnt;
 419
 420 /* Returns > 0 if metadata should be collected */
 421 static inline int ip_tunnel_collect_metadata(void)
 422 {
 423         return static_key_false(&ip_tunnel_metadata_cnt);
 424 }
 425
 426 void __init ip_tunnel_core_init(void);
 427
 428 void ip_tunnel_need_metadata(void);
 429 void ip_tunnel_unneed_metadata(void);
 430
 431 #else /* CONFIG_INET */
 432
 433 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 434 {
 435         return NULL;
 436 }
 437
 438 static inline void ip_tunnel_need_metadata(void)
 439 {
 440 }
 441
 442 static inline void ip_tunnel_unneed_metadata(void)
 443 {
 444 }
 445
 446 static inline void ip_tunnel_info_opts_get(void *to,
 447                                            const struct ip_tunnel_info *info)
 448 {
 449 }
 450
 451 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 452                                            const void *from, int len)
 453 {
 454         info->options_len = 0;
 455 }
 456
 457 #endif /* CONFIG_INET */
 458
 459 #endif /* __NET_IP_TUNNELS_H */