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 u32 nhid; 56 __be16 tp_src; 57 __be16 tp_dst; 58 __u8 flow_flags; 59 }; 60 61 struct ip_tunnel_encap { 62 u16 type; 63 u16 flags; 64 __be16 sport; 65 __be16 dport; 66 }; 67 68 /* Flags for ip_tunnel_info mode. */ 69 #define IP_TUNNEL_INFO_TX 0x01 /* represents tx tunnel parameters */ 70 #define IP_TUNNEL_INFO_IPV6 0x02 /* key contains IPv6 addresses */ 71 #define IP_TUNNEL_INFO_BRIDGE 0x04 /* represents a bridged tunnel id */ 72 73 /* Maximum tunnel options length. */ 74 #define IP_TUNNEL_OPTS_MAX \ 75 GENMASK((sizeof_field(struct ip_tunnel_info, \ 76 options_len) * BITS_PER_BYTE) - 1, 0) 77 78 #define ip_tunnel_info_opts(info) \ 79 _Generic(info, \ 80 const struct ip_tunnel_info * : ((const void *)((info) + 1)),\ 81 struct ip_tunnel_info * : ((void *)((info) + 1))\ 82 ) 83 84 struct ip_tunnel_info { 85 struct ip_tunnel_key key; 86 struct ip_tunnel_encap encap; 87 #ifdef CONFIG_DST_CACHE 88 struct dst_cache dst_cache; 89 #endif 90 u8 options_len; 91 u8 mode; 92 }; 93 94 /* 6rd prefix/relay information */ 95 #ifdef CONFIG_IPV6_SIT_6RD 96 struct ip_tunnel_6rd_parm { 97 struct in6_addr prefix; 98 __be32 relay_prefix; 99 u16 prefixlen; 100 u16 relay_prefixlen; 101 }; 102 #endif 103 104 struct ip_tunnel_prl_entry { 105 struct ip_tunnel_prl_entry __rcu *next; 106 __be32 addr; 107 u16 flags; 108 struct rcu_head rcu_head; 109 }; 110 111 struct metadata_dst; 112 113 struct ip_tunnel { 114 struct ip_tunnel __rcu *next; 115 struct hlist_node hash_node; 116 117 struct net_device *dev; 118 netdevice_tracker dev_tracker; 119 120 struct net *net; /* netns for packet i/o */ 121 122 unsigned long err_time; /* Time when the last ICMP error 123 * arrived */ 124 int err_count; /* Number of arrived ICMP errors */ 125 126 /* These four fields used only by GRE */ 127 u32 i_seqno; /* The last seen seqno */ 128 atomic_t o_seqno; /* The last output seqno */ 129 int tun_hlen; /* Precalculated header length */ 130 131 /* These four fields used only by ERSPAN */ 132 u32 index; /* ERSPAN type II index */ 133 u8 erspan_ver; /* ERSPAN version */ 134 u8 dir; /* ERSPAN direction */ 135 u16 hwid; /* ERSPAN hardware ID */ 136 137 struct dst_cache dst_cache; 138 139 struct ip_tunnel_parm parms; 140 141 int mlink; 142 int encap_hlen; /* Encap header length (FOU,GUE) */ 143 int hlen; /* tun_hlen + encap_hlen */ 144 struct ip_tunnel_encap encap; 145 146 /* for SIT */ 147 #ifdef CONFIG_IPV6_SIT_6RD 148 struct ip_tunnel_6rd_parm ip6rd; 149 #endif 150 struct ip_tunnel_prl_entry __rcu *prl; /* potential router list */ 151 unsigned int prl_count; /* # of entries in PRL */ 152 unsigned int ip_tnl_net_id; 153 struct gro_cells gro_cells; 154 __u32 fwmark; 155 bool collect_md; 156 bool ignore_df; 157 }; 158 159 struct tnl_ptk_info { 160 __be16 flags; 161 __be16 proto; 162 __be32 key; 163 __be32 seq; 164 int hdr_len; 165 }; 166 167 #define PACKET_RCVD 0 168 #define PACKET_REJECT 1 169 #define PACKET_NEXT 2 170 171 #define IP_TNL_HASH_BITS 7 172 #define IP_TNL_HASH_SIZE (1 << IP_TNL_HASH_BITS) 173 174 struct ip_tunnel_net { 175 struct net_device *fb_tunnel_dev; 176 struct rtnl_link_ops *rtnl_link_ops; 177 struct hlist_head tunnels[IP_TNL_HASH_SIZE]; 178 struct ip_tunnel __rcu *collect_md_tun; 179 int type; 180 }; 181 182 static inline void ip_tunnel_key_init(struct ip_tunnel_key *key, 183 __be32 saddr, __be32 daddr, 184 u8 tos, u8 ttl, __be32 label, 185 __be16 tp_src, __be16 tp_dst, 186 __be64 tun_id, __be16 tun_flags) 187 { 188 key->tun_id = tun_id; 189 key->u.ipv4.src = saddr; 190 key->u.ipv4.dst = daddr; 191 memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD, 192 0, IP_TUNNEL_KEY_IPV4_PAD_LEN); 193 key->tos = tos; 194 key->ttl = ttl; 195 key->label = label; 196 key->tun_flags = tun_flags; 197 198 /* For the tunnel types on the top of IPsec, the tp_src and tp_dst of 199 * the upper tunnel are used. 200 * E.g: GRE over IPSEC, the tp_src and tp_port are zero. 201 */ 202 key->tp_src = tp_src; 203 key->tp_dst = tp_dst; 204 205 /* Clear struct padding. */ 206 if (sizeof(*key) != IP_TUNNEL_KEY_SIZE) 207 memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE, 208 0, sizeof(*key) - IP_TUNNEL_KEY_SIZE); 209 } 210 211 static inline bool 212 ip_tunnel_dst_cache_usable(const struct sk_buff *skb, 213 const struct ip_tunnel_info *info) 214 { 215 if (skb->mark) 216 return false; 217 if (!info) 218 return true; 219 if (info->key.tun_flags & TUNNEL_NOCACHE) 220 return false; 221 222 return true; 223 } 224 225 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info 226 *tun_info) 227 { 228 return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET; 229 } 230 231 static inline __be64 key32_to_tunnel_id(__be32 key) 232 { 233 #ifdef __BIG_ENDIAN 234 return (__force __be64)key; 235 #else 236 return (__force __be64)((__force u64)key << 32); 237 #endif 238 } 239 240 /* Returns the least-significant 32 bits of a __be64. */ 241 static inline __be32 tunnel_id_to_key32(__be64 tun_id) 242 { 243 #ifdef __BIG_ENDIAN 244 return (__force __be32)tun_id; 245 #else 246 return (__force __be32)((__force u64)tun_id >> 32); 247 #endif 248 } 249 250 #ifdef CONFIG_INET 251 252 static inline void ip_tunnel_init_flow(struct flowi4 *fl4, 253 int proto, 254 __be32 daddr, __be32 saddr, 255 __be32 key, __u8 tos, 256 struct net *net, int oif, 257 __u32 mark, __u32 tun_inner_hash, 258 __u8 flow_flags) 259 { 260 memset(fl4, 0, sizeof(*fl4)); 261 262 if (oif) { 263 fl4->flowi4_l3mdev = l3mdev_master_upper_ifindex_by_index(net, oif); 264 /* Legacy VRF/l3mdev use case */ 265 fl4->flowi4_oif = fl4->flowi4_l3mdev ? 0 : oif; 266 } 267 268 fl4->daddr = daddr; 269 fl4->saddr = saddr; 270 fl4->flowi4_tos = tos; 271 fl4->flowi4_proto = proto; 272 fl4->fl4_gre_key = key; 273 fl4->flowi4_mark = mark; 274 fl4->flowi4_multipath_hash = tun_inner_hash; 275 fl4->flowi4_flags = flow_flags; 276 } 277 278 int ip_tunnel_init(struct net_device *dev); 279 void ip_tunnel_uninit(struct net_device *dev); 280 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head); 281 struct net *ip_tunnel_get_link_net(const struct net_device *dev); 282 int ip_tunnel_get_iflink(const struct net_device *dev); 283 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id, 284 struct rtnl_link_ops *ops, char *devname); 285 286 void ip_tunnel_delete_nets(struct list_head *list_net, unsigned int id, 287 struct rtnl_link_ops *ops); 288 289 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 290 const struct iphdr *tnl_params, const u8 protocol); 291 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 292 const u8 proto, int tunnel_hlen); 293 int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd); 294 int ip_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 295 void __user *data, int cmd); 296 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict); 297 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu); 298 299 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, 300 int link, __be16 flags, 301 __be32 remote, __be32 local, 302 __be32 key); 303 304 void ip_tunnel_md_udp_encap(struct sk_buff *skb, struct ip_tunnel_info *info); 305 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, 306 const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst, 307 bool log_ecn_error); 308 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[], 309 struct ip_tunnel_parm *p, __u32 fwmark); 310 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], 311 struct ip_tunnel_parm *p, __u32 fwmark); 312 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id); 313 314 bool ip_tunnel_netlink_encap_parms(struct nlattr *data[], 315 struct ip_tunnel_encap *encap); 316 317 void ip_tunnel_netlink_parms(struct nlattr *data[], 318 struct ip_tunnel_parm *parms); 319 320 extern const struct header_ops ip_tunnel_header_ops; 321 __be16 ip_tunnel_parse_protocol(const struct sk_buff *skb); 322 323 struct ip_tunnel_encap_ops { 324 size_t (*encap_hlen)(struct ip_tunnel_encap *e); 325 int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e, 326 u8 *protocol, struct flowi4 *fl4); 327 int (*err_handler)(struct sk_buff *skb, u32 info); 328 }; 329 330 #define MAX_IPTUN_ENCAP_OPS 8 331 332 extern const struct ip_tunnel_encap_ops __rcu * 333 iptun_encaps[MAX_IPTUN_ENCAP_OPS]; 334 335 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op, 336 unsigned int num); 337 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op, 338 unsigned int num); 339 340 int ip_tunnel_encap_setup(struct ip_tunnel *t, 341 struct ip_tunnel_encap *ipencap); 342 343 static inline bool pskb_inet_may_pull(struct sk_buff *skb) 344 { 345 int nhlen; 346 347 switch (skb->protocol) { 348 #if IS_ENABLED(CONFIG_IPV6) 349 case htons(ETH_P_IPV6): 350 nhlen = sizeof(struct ipv6hdr); 351 break; 352 #endif 353 case htons(ETH_P_IP): 354 nhlen = sizeof(struct iphdr); 355 break; 356 default: 357 nhlen = 0; 358 } 359 360 return pskb_network_may_pull(skb, nhlen); 361 } 362 363 /* Variant of pskb_inet_may_pull(). 364 */ 365 static inline bool skb_vlan_inet_prepare(struct sk_buff *skb, 366 bool inner_proto_inherit) 367 { 368 int nhlen = 0, maclen = inner_proto_inherit ? 0 : ETH_HLEN; 369 __be16 type = skb->protocol; 370 371 /* Essentially this is skb_protocol(skb, true) 372 * And we get MAC len. 373 */ 374 if (eth_type_vlan(type)) 375 type = __vlan_get_protocol(skb, type, &maclen); 376 377 switch (type) { 378 #if IS_ENABLED(CONFIG_IPV6) 379 case htons(ETH_P_IPV6): 380 nhlen = sizeof(struct ipv6hdr); 381 break; 382 #endif 383 case htons(ETH_P_IP): 384 nhlen = sizeof(struct iphdr); 385 break; 386 } 387 /* For ETH_P_IPV6/ETH_P_IP we make sure to pull 388 * a base network header in skb->head. 389 */ 390 if (!pskb_may_pull(skb, maclen + nhlen)) 391 return false; 392 393 skb_set_network_header(skb, maclen); 394 return true; 395 } 396 397 static inline int ip_encap_hlen(struct ip_tunnel_encap *e) 398 { 399 const struct ip_tunnel_encap_ops *ops; 400 int hlen = -EINVAL; 401 402 if (e->type == TUNNEL_ENCAP_NONE) 403 return 0; 404 405 if (e->type >= MAX_IPTUN_ENCAP_OPS) 406 return -EINVAL; 407 408 rcu_read_lock(); 409 ops = rcu_dereference(iptun_encaps[e->type]); 410 if (likely(ops && ops->encap_hlen)) 411 hlen = ops->encap_hlen(e); 412 rcu_read_unlock(); 413 414 return hlen; 415 } 416 417 static inline int ip_tunnel_encap(struct sk_buff *skb, 418 struct ip_tunnel_encap *e, 419 u8 *protocol, struct flowi4 *fl4) 420 { 421 const struct ip_tunnel_encap_ops *ops; 422 int ret = -EINVAL; 423 424 if (e->type == TUNNEL_ENCAP_NONE) 425 return 0; 426 427 if (e->type >= MAX_IPTUN_ENCAP_OPS) 428 return -EINVAL; 429 430 rcu_read_lock(); 431 ops = rcu_dereference(iptun_encaps[e->type]); 432 if (likely(ops && ops->build_header)) 433 ret = ops->build_header(skb, e, protocol, fl4); 434 rcu_read_unlock(); 435 436 return ret; 437 } 438 439 /* Extract dsfield from inner protocol */ 440 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph, 441 const struct sk_buff *skb) 442 { 443 __be16 payload_protocol = skb_protocol(skb, true); 444 445 if (payload_protocol == htons(ETH_P_IP)) 446 return iph->tos; 447 else if (payload_protocol == htons(ETH_P_IPV6)) 448 return ipv6_get_dsfield((const struct ipv6hdr *)iph); 449 else 450 return 0; 451 } 452 453 static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph, 454 const struct sk_buff *skb) 455 { 456 __be16 payload_protocol = skb_protocol(skb, true); 457 458 if (payload_protocol == htons(ETH_P_IP)) 459 return iph->ttl; 460 else if (payload_protocol == htons(ETH_P_IPV6)) 461 return ((const struct ipv6hdr *)iph)->hop_limit; 462 else 463 return 0; 464 } 465 466 /* Propogate ECN bits out */ 467 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph, 468 const struct sk_buff *skb) 469 { 470 u8 inner = ip_tunnel_get_dsfield(iph, skb); 471 472 return INET_ECN_encapsulate(tos, inner); 473 } 474 475 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len, 476 __be16 inner_proto, bool raw_proto, bool xnet); 477 478 static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, 479 __be16 inner_proto, bool xnet) 480 { 481 return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet); 482 } 483 484 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb, 485 __be32 src, __be32 dst, u8 proto, 486 u8 tos, u8 ttl, __be16 df, bool xnet); 487 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md, 488 gfp_t flags); 489 int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst, 490 int headroom, bool reply); 491 492 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask); 493 494 static inline int iptunnel_pull_offloads(struct sk_buff *skb) 495 { 496 if (skb_is_gso(skb)) { 497 int err; 498 499 err = skb_unclone(skb, GFP_ATOMIC); 500 if (unlikely(err)) 501 return err; 502 skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >> 503 NETIF_F_GSO_SHIFT); 504 } 505 506 skb->encapsulation = 0; 507 return 0; 508 } 509 510 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len) 511 { 512 if (pkt_len > 0) { 513 struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats); 514 515 u64_stats_update_begin(&tstats->syncp); 516 u64_stats_add(&tstats->tx_bytes, pkt_len); 517 u64_stats_inc(&tstats->tx_packets); 518 u64_stats_update_end(&tstats->syncp); 519 put_cpu_ptr(tstats); 520 return; 521 } 522 523 if (pkt_len < 0) { 524 DEV_STATS_INC(dev, tx_errors); 525 DEV_STATS_INC(dev, tx_aborted_errors); 526 } else { 527 DEV_STATS_INC(dev, tx_dropped); 528 } 529 } 530 531 static inline void ip_tunnel_info_opts_get(void *to, 532 const struct ip_tunnel_info *info) 533 { 534 memcpy(to, info + 1, info->options_len); 535 } 536 537 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info, 538 const void *from, int len, 539 __be16 flags) 540 { 541 info->options_len = len; 542 if (len > 0) { 543 memcpy(ip_tunnel_info_opts(info), from, len); 544 info->key.tun_flags |= flags; 545 } 546 } 547 548 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate) 549 { 550 return (struct ip_tunnel_info *)lwtstate->data; 551 } 552 553 DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt); 554 555 /* Returns > 0 if metadata should be collected */ 556 static inline int ip_tunnel_collect_metadata(void) 557 { 558 return static_branch_unlikely(&ip_tunnel_metadata_cnt); 559 } 560 561 void __init ip_tunnel_core_init(void); 562 563 void ip_tunnel_need_metadata(void); 564 void ip_tunnel_unneed_metadata(void); 565 566 #else /* CONFIG_INET */ 567 568 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate) 569 { 570 return NULL; 571 } 572 573 static inline void ip_tunnel_need_metadata(void) 574 { 575 } 576 577 static inline void ip_tunnel_unneed_metadata(void) 578 { 579 } 580 581 static inline void ip_tunnel_info_opts_get(void *to, 582 const struct ip_tunnel_info *info) 583 { 584 } 585 586 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info, 587 const void *from, int len, 588 __be16 flags) 589 { 590 info->options_len = 0; 591 } 592 593 #endif /* CONFIG_INET */ 594 595 #endif /* __NET_IP_TUNNELS_H */ 596