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         int             err_count;      /* Number of arrived ICMP errors */
 109         unsigned long   err_time;       /* Time when the last ICMP error
 110                                          * arrived */
 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         int             mlink;
 117
 118         struct dst_cache dst_cache;
 119
 120         struct ip_tunnel_parm parms;
 121
 122         int             encap_hlen;     /* Encap header length (FOU,GUE) */
 123         struct ip_tunnel_encap encap;
 124
 125         int             hlen;           /* tun_hlen + encap_hlen */
 126
 127         /* for SIT */
 128 #ifdef CONFIG_IPV6_SIT_6RD
 129         struct ip_tunnel_6rd_parm ip6rd;
 130 #endif
 131         struct ip_tunnel_prl_entry __rcu *prl;  /* potential router list */
 132         unsigned int            prl_count;      /* # of entries in PRL */
 133         int                     ip_tnl_net_id;
 134         struct gro_cells        gro_cells;
 135         bool                    collect_md;
 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 };
 161
 162 #define PACKET_RCVD     0
 163 #define PACKET_REJECT   1
 164
 165 #define IP_TNL_HASH_BITS   7
 166 #define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
 167
 168 struct ip_tunnel_net {
 169         struct net_device *fb_tunnel_dev;
 170         struct hlist_head tunnels[IP_TNL_HASH_SIZE];
 171         struct ip_tunnel __rcu *collect_md_tun;
 172 };
 173
 174 struct ip_tunnel_encap_ops {
 175         size_t (*encap_hlen)(struct ip_tunnel_encap *e);
 176         int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
 177                             u8 *protocol, struct flowi4 *fl4);
 178 };
 179
 180 #define MAX_IPTUN_ENCAP_OPS 8
 181
 182 extern const struct ip_tunnel_encap_ops __rcu *
 183                 iptun_encaps[MAX_IPTUN_ENCAP_OPS];
 184
 185 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
 186                             unsigned int num);
 187 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
 188                             unsigned int num);
 189
 190 static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
 191                                       __be32 saddr, __be32 daddr,
 192                                       u8 tos, u8 ttl, __be32 label,
 193                                       __be16 tp_src, __be16 tp_dst,
 194                                       __be64 tun_id, __be16 tun_flags)
 195 {
 196         key->tun_id = tun_id;
 197         key->u.ipv4.src = saddr;
 198         key->u.ipv4.dst = daddr;
 199         memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
 200                0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
 201         key->tos = tos;
 202         key->ttl = ttl;
 203         key->label = label;
 204         key->tun_flags = tun_flags;
 205
 206         /* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
 207          * the upper tunnel are used.
 208          * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
 209          */
 210         key->tp_src = tp_src;
 211         key->tp_dst = tp_dst;
 212
 213         /* Clear struct padding. */
 214         if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
 215                 memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
 216                        0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
 217 }
 218
 219 static inline bool
 220 ip_tunnel_dst_cache_usable(const struct sk_buff *skb,
 221                            const struct ip_tunnel_info *info)
 222 {
 223         if (skb->mark)
 224                 return false;
 225         if (!info)
 226                 return true;
 227         if (info->key.tun_flags & TUNNEL_NOCACHE)
 228                 return false;
 229
 230         return true;
 231 }
 232
 233 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
 234                                                *tun_info)
 235 {
 236         return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
 237 }
 238
 239 #ifdef CONFIG_INET
 240
 241 int ip_tunnel_init(struct net_device *dev);
 242 void ip_tunnel_uninit(struct net_device *dev);
 243 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
 244 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
 245 int ip_tunnel_get_iflink(const struct net_device *dev);
 246 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
 247                        struct rtnl_link_ops *ops, char *devname);
 248
 249 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
 250
 251 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 252                     const struct iphdr *tnl_params, const u8 protocol);
 253 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
 254 int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
 255                     u8 *protocol, struct flowi4 *fl4);
 256 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
 257 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
 258
 259 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
 260                                                 struct rtnl_link_stats64 *tot);
 261 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
 262                                    int link, __be16 flags,
 263                                    __be32 remote, __be32 local,
 264                                    __be32 key);
 265
 266 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
 267                   const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
 268                   bool log_ecn_error);
 269 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 270                          struct ip_tunnel_parm *p);
 271 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
 272                       struct ip_tunnel_parm *p);
 273 void ip_tunnel_setup(struct net_device *dev, int net_id);
 274 int ip_tunnel_encap_setup(struct ip_tunnel *t,
 275                           struct ip_tunnel_encap *ipencap);
 276
 277 /* Extract dsfield from inner protocol */
 278 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
 279                                        const struct sk_buff *skb)
 280 {
 281         if (skb->protocol == htons(ETH_P_IP))
 282                 return iph->tos;
 283         else if (skb->protocol == htons(ETH_P_IPV6))
 284                 return ipv6_get_dsfield((const struct ipv6hdr *)iph);
 285         else
 286                 return 0;
 287 }
 288
 289 /* Propogate ECN bits out */
 290 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
 291                                      const struct sk_buff *skb)
 292 {
 293         u8 inner = ip_tunnel_get_dsfield(iph, skb);
 294
 295         return INET_ECN_encapsulate(tos, inner);
 296 }
 297
 298 int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto,
 299                          bool xnet);
 300 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 301                    __be32 src, __be32 dst, u8 proto,
 302                    u8 tos, u8 ttl, __be16 df, bool xnet);
 303 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 304                                              gfp_t flags);
 305
 306 struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
 307
 308 static inline int iptunnel_pull_offloads(struct sk_buff *skb)
 309 {
 310         if (skb_is_gso(skb)) {
 311                 int err;
 312
 313                 err = skb_unclone(skb, GFP_ATOMIC);
 314                 if (unlikely(err))
 315                         return err;
 316                 skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
 317                                                NETIF_F_GSO_SHIFT);
 318         }
 319
 320         skb->encapsulation = 0;
 321         return 0;
 322 }
 323
 324 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
 325 {
 326         if (pkt_len > 0) {
 327                 struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
 328
 329                 u64_stats_update_begin(&tstats->syncp);
 330                 tstats->tx_bytes += pkt_len;
 331                 tstats->tx_packets++;
 332                 u64_stats_update_end(&tstats->syncp);
 333                 put_cpu_ptr(tstats);
 334         } else {
 335                 struct net_device_stats *err_stats = &dev->stats;
 336
 337                 if (pkt_len < 0) {
 338                         err_stats->tx_errors++;
 339                         err_stats->tx_aborted_errors++;
 340                 } else {
 341                         err_stats->tx_dropped++;
 342                 }
 343         }
 344 }
 345
 346 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
 347 {
 348         return info + 1;
 349 }
 350
 351 static inline void ip_tunnel_info_opts_get(void *to,
 352                                            const struct ip_tunnel_info *info)
 353 {
 354         memcpy(to, info + 1, info->options_len);
 355 }
 356
 357 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 358                                            const void *from, int len)
 359 {
 360         memcpy(ip_tunnel_info_opts(info), from, len);
 361         info->options_len = len;
 362 }
 363
 364 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 365 {
 366         return (struct ip_tunnel_info *)lwtstate->data;
 367 }
 368
 369 extern struct static_key ip_tunnel_metadata_cnt;
 370
 371 /* Returns > 0 if metadata should be collected */
 372 static inline int ip_tunnel_collect_metadata(void)
 373 {
 374         return static_key_false(&ip_tunnel_metadata_cnt);
 375 }
 376
 377 void __init ip_tunnel_core_init(void);
 378
 379 void ip_tunnel_need_metadata(void);
 380 void ip_tunnel_unneed_metadata(void);
 381
 382 #else /* CONFIG_INET */
 383
 384 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
 385 {
 386         return NULL;
 387 }
 388
 389 static inline void ip_tunnel_need_metadata(void)
 390 {
 391 }
 392
 393 static inline void ip_tunnel_unneed_metadata(void)
 394 {
 395 }
 396
 397 static inline void ip_tunnel_info_opts_get(void *to,
 398                                            const struct ip_tunnel_info *info)
 399 {
 400 }
 401
 402 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
 403                                            const void *from, int len)
 404 {
 405         info->options_len = 0;
 406 }
 407
 408 #endif /* CONFIG_INET */
 409
 410 #endif /* __NET_IP_TUNNELS_H */