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 39 struct 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 69 struct 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 80 struct ip_tunnel_6rd_parm { 81 struct in6_addr prefix; 82 __be32 relay_prefix; 83 u16 prefixlen; 84 u16 relay_prefixlen; 85 }; 86 #endif 87 88 struct ip_tunnel_encap { 89 u16 type; 90 u16 flags; 91 __be16 sport; 92 __be16 dport; 93 }; 94 95 struct 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 }; 101 102 struct metadata_dst; 103 104 struct 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 }; 149 150 struct 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) 164 165 struct 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 }; 172 173 static 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 } 201 202 static inline bool 203 ip_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 } 215 216 static 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 } 221 222 static 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. */ 232 static 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 242 243 static 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 } 266 267 int ip_tunnel_init(struct net_device *dev); 268 void ip_tunnel_uninit(struct net_device *dev); 269 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head); 270 struct net *ip_tunnel_get_link_net(const struct net_device *dev); 271 int ip_tunnel_get_iflink(const struct net_device *dev); 272 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id, 273 struct rtnl_link_ops *ops, char *devname); 274 275 void ip_tunnel_delete_nets(struct list_head *list_net, unsigned int id, 276 struct rtnl_link_ops *ops); 277 278 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 279 const struct iphdr *tnl_params, const u8 protocol); 280 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 281 const u8 proto, int tunnel_hlen); 282 int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd); 283 int ip_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 284 void __user *data, int cmd); 285 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict); 286 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu); 287 288 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, 289 int link, __be16 flags, 290 __be32 remote, __be32 local, 291 __be32 key); 292 293 int 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); 296 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[], 297 struct ip_tunnel_parm *p, __u32 fwmark); 298 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], 299 struct ip_tunnel_parm *p, __u32 fwmark); 300 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id); 301 302 extern const struct header_ops ip_tunnel_header_ops; 303 __be16 ip_tunnel_parse_protocol(const struct sk_buff *skb); 304 305 struct 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 8 313 314 extern const struct ip_tunnel_encap_ops __rcu * 315 iptun_encaps[MAX_IPTUN_ENCAP_OPS]; 316 317 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op, 318 unsigned int num); 319 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op, 320 unsigned int num); 321 322 int ip_tunnel_encap_setup(struct ip_tunnel *t, 323 struct ip_tunnel_encap *ipencap); 324 325 static 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 } 344 345 static 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 } 364 365 static 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 */ 387 static 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 } 397 398 static 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 */ 410 static 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 } 417 418 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len, 419 __be16 inner_proto, bool raw_proto, bool xnet); 420 421 static 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 } 426 427 void 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); 430 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md, 431 gfp_t flags); 432 int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst, 433 int headroom, bool reply); 434 435 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask); 436 437 static 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 } 452 453 static 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 } 474 475 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info) 476 { 477 return info + 1; 478 } 479 480 static 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 } 485 486 static 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 } 496 497 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate) 498 { 499 return (struct ip_tunnel_info *)lwtstate->data; 500 } 501 502 DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt); 503 504 /* Returns > 0 if metadata should be collected */ 505 static inline int ip_tunnel_collect_metadata(void) 506 { 507 return static_branch_unlikely(&ip_tunnel_metadata_cnt); 508 } 509 510 void __init ip_tunnel_core_init(void); 511 512 void ip_tunnel_need_metadata(void); 513 void ip_tunnel_unneed_metadata(void); 514 515 #else /* CONFIG_INET */ 516 517 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate) 518 { 519 return NULL; 520 } 521 522 static inline void ip_tunnel_need_metadata(void) 523 { 524 } 525 526 static inline void ip_tunnel_unneed_metadata(void) 527 { 528 } 529 530 static inline void ip_tunnel_info_opts_get(void *to, 531 const struct ip_tunnel_info *info) 532 { 533 } 534 535 static 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