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 __u8 flow_flags; 58 }; 59 60 struct ip_tunnel_encap { 61 u16 type; 62 u16 flags; 63 __be16 sport; 64 __be16 dport; 65 }; 66 67 /* Flags for ip_tunnel_info mode. */ 68 #define IP_TUNNEL_INFO_TX 0x01 /* represents tx tunnel parameters */ 69 #define IP_TUNNEL_INFO_IPV6 0x02 /* key contains IPv6 addresses */ 70 #define IP_TUNNEL_INFO_BRIDGE 0x04 /* represents a bridged tunnel id */ 71 72 /* Maximum tunnel options length. */ 73 #define IP_TUNNEL_OPTS_MAX \ 74 GENMASK((sizeof_field(struct ip_tunnel_info, \ 75 options_len) * BITS_PER_BYTE) - 1, 0) 76 77 #define ip_tunnel_info_opts(info) \ 78 _Generic(info, \ 79 const struct ip_tunnel_info * : ((const void *)((info) + 1)),\ 80 struct ip_tunnel_info * : ((void *)((info) + 1))\ 81 ) 82 83 struct ip_tunnel_info { 84 struct ip_tunnel_key key; 85 struct ip_tunnel_encap encap; 86 #ifdef CONFIG_DST_CACHE 87 struct dst_cache dst_cache; 88 #endif 89 u8 options_len; 90 u8 mode; 91 }; 92 93 /* 6rd prefix/relay information */ 94 #ifdef CONFIG_IPV6_SIT_6RD 95 struct ip_tunnel_6rd_parm { 96 struct in6_addr prefix; 97 __be32 relay_prefix; 98 u16 prefixlen; 99 u16 relay_prefixlen; 100 }; 101 #endif 102 103 struct ip_tunnel_prl_entry { 104 struct ip_tunnel_prl_entry __rcu *next; 105 __be32 addr; 106 u16 flags; 107 struct rcu_head rcu_head; 108 }; 109 110 struct metadata_dst; 111 112 struct ip_tunnel { 113 struct ip_tunnel __rcu *next; 114 struct hlist_node hash_node; 115 116 struct net_device *dev; 117 netdevice_tracker dev_tracker; 118 119 struct net *net; /* netns for packet i/o */ 120 121 unsigned long err_time; /* Time when the last ICMP error 122 * arrived */ 123 int err_count; /* Number of arrived ICMP errors */ 124 125 /* These four fields used only by GRE */ 126 u32 i_seqno; /* The last seen seqno */ 127 atomic_t o_seqno; /* The last output seqno */ 128 int tun_hlen; /* Precalculated header length */ 129 130 /* These four fields used only by ERSPAN */ 131 u32 index; /* ERSPAN type II index */ 132 u8 erspan_ver; /* ERSPAN version */ 133 u8 dir; /* ERSPAN direction */ 134 u16 hwid; /* ERSPAN hardware ID */ 135 136 struct dst_cache dst_cache; 137 138 struct ip_tunnel_parm parms; 139 140 int mlink; 141 int encap_hlen; /* Encap header length (FOU,GUE) */ 142 int hlen; /* tun_hlen + encap_hlen */ 143 struct ip_tunnel_encap encap; 144 145 /* for SIT */ 146 #ifdef CONFIG_IPV6_SIT_6RD 147 struct ip_tunnel_6rd_parm ip6rd; 148 #endif 149 struct ip_tunnel_prl_entry __rcu *prl; /* potential router list */ 150 unsigned int prl_count; /* # of entries in PRL */ 151 unsigned int ip_tnl_net_id; 152 struct gro_cells gro_cells; 153 __u32 fwmark; 154 bool collect_md; 155 bool ignore_df; 156 }; 157 158 struct tnl_ptk_info { 159 __be16 flags; 160 __be16 proto; 161 __be32 key; 162 __be32 seq; 163 int hdr_len; 164 }; 165 166 #define PACKET_RCVD 0 167 #define PACKET_REJECT 1 168 #define PACKET_NEXT 2 169 170 #define IP_TNL_HASH_BITS 7 171 #define IP_TNL_HASH_SIZE (1 << IP_TNL_HASH_BITS) 172 173 struct ip_tunnel_net { 174 struct net_device *fb_tunnel_dev; 175 struct rtnl_link_ops *rtnl_link_ops; 176 struct hlist_head tunnels[IP_TNL_HASH_SIZE]; 177 struct ip_tunnel __rcu *collect_md_tun; 178 int type; 179 }; 180 181 static inline void ip_tunnel_key_init(struct ip_tunnel_key *key, 182 __be32 saddr, __be32 daddr, 183 u8 tos, u8 ttl, __be32 label, 184 __be16 tp_src, __be16 tp_dst, 185 __be64 tun_id, __be16 tun_flags) 186 { 187 key->tun_id = tun_id; 188 key->u.ipv4.src = saddr; 189 key->u.ipv4.dst = daddr; 190 memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD, 191 0, IP_TUNNEL_KEY_IPV4_PAD_LEN); 192 key->tos = tos; 193 key->ttl = ttl; 194 key->label = label; 195 key->tun_flags = tun_flags; 196 197 /* For the tunnel types on the top of IPsec, the tp_src and tp_dst of 198 * the upper tunnel are used. 199 * E.g: GRE over IPSEC, the tp_src and tp_port are zero. 200 */ 201 key->tp_src = tp_src; 202 key->tp_dst = tp_dst; 203 204 /* Clear struct padding. */ 205 if (sizeof(*key) != IP_TUNNEL_KEY_SIZE) 206 memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE, 207 0, sizeof(*key) - IP_TUNNEL_KEY_SIZE); 208 } 209 210 static inline bool 211 ip_tunnel_dst_cache_usable(const struct sk_buff *skb, 212 const struct ip_tunnel_info *info) 213 { 214 if (skb->mark) 215 return false; 216 if (!info) 217 return true; 218 if (info->key.tun_flags & TUNNEL_NOCACHE) 219 return false; 220 221 return true; 222 } 223 224 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info 225 *tun_info) 226 { 227 return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET; 228 } 229 230 static inline __be64 key32_to_tunnel_id(__be32 key) 231 { 232 #ifdef __BIG_ENDIAN 233 return (__force __be64)key; 234 #else 235 return (__force __be64)((__force u64)key << 32); 236 #endif 237 } 238 239 /* Returns the least-significant 32 bits of a __be64. */ 240 static inline __be32 tunnel_id_to_key32(__be64 tun_id) 241 { 242 #ifdef __BIG_ENDIAN 243 return (__force __be32)tun_id; 244 #else 245 return (__force __be32)((__force u64)tun_id >> 32); 246 #endif 247 } 248 249 #ifdef CONFIG_INET 250 251 static inline void ip_tunnel_init_flow(struct flowi4 *fl4, 252 int proto, 253 __be32 daddr, __be32 saddr, 254 __be32 key, __u8 tos, 255 struct net *net, int oif, 256 __u32 mark, __u32 tun_inner_hash, 257 __u8 flow_flags) 258 { 259 memset(fl4, 0, sizeof(*fl4)); 260 261 if (oif) { 262 fl4->flowi4_l3mdev = l3mdev_master_upper_ifindex_by_index_rcu(net, oif); 263 /* Legacy VRF/l3mdev use case */ 264 fl4->flowi4_oif = fl4->flowi4_l3mdev ? 0 : oif; 265 } 266 267 fl4->daddr = daddr; 268 fl4->saddr = saddr; 269 fl4->flowi4_tos = tos; 270 fl4->flowi4_proto = proto; 271 fl4->fl4_gre_key = key; 272 fl4->flowi4_mark = mark; 273 fl4->flowi4_multipath_hash = tun_inner_hash; 274 fl4->flowi4_flags = flow_flags; 275 } 276 277 int ip_tunnel_init(struct net_device *dev); 278 void ip_tunnel_uninit(struct net_device *dev); 279 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head); 280 struct net *ip_tunnel_get_link_net(const struct net_device *dev); 281 int ip_tunnel_get_iflink(const struct net_device *dev); 282 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id, 283 struct rtnl_link_ops *ops, char *devname); 284 285 void ip_tunnel_delete_nets(struct list_head *list_net, unsigned int id, 286 struct rtnl_link_ops *ops); 287 288 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 289 const struct iphdr *tnl_params, const u8 protocol); 290 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 291 const u8 proto, int tunnel_hlen); 292 int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd); 293 int ip_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 294 void __user *data, int cmd); 295 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict); 296 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu); 297 298 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, 299 int link, __be16 flags, 300 __be32 remote, __be32 local, 301 __be32 key); 302 303 void ip_tunnel_md_udp_encap(struct sk_buff *skb, struct ip_tunnel_info *info); 304 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, 305 const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst, 306 bool log_ecn_error); 307 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[], 308 struct ip_tunnel_parm *p, __u32 fwmark); 309 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], 310 struct ip_tunnel_parm *p, __u32 fwmark); 311 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id); 312 313 bool ip_tunnel_netlink_encap_parms(struct nlattr *data[], 314 struct ip_tunnel_encap *encap); 315 316 void ip_tunnel_netlink_parms(struct nlattr *data[], 317 struct ip_tunnel_parm *parms); 318 319 extern const struct header_ops ip_tunnel_header_ops; 320 __be16 ip_tunnel_parse_protocol(const struct sk_buff *skb); 321 322 struct ip_tunnel_encap_ops { 323 size_t (*encap_hlen)(struct ip_tunnel_encap *e); 324 int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e, 325 u8 *protocol, struct flowi4 *fl4); 326 int (*err_handler)(struct sk_buff *skb, u32 info); 327 }; 328 329 #define MAX_IPTUN_ENCAP_OPS 8 330 331 extern const struct ip_tunnel_encap_ops __rcu * 332 iptun_encaps[MAX_IPTUN_ENCAP_OPS]; 333 334 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op, 335 unsigned int num); 336 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op, 337 unsigned int num); 338 339 int ip_tunnel_encap_setup(struct ip_tunnel *t, 340 struct ip_tunnel_encap *ipencap); 341 342 static inline bool pskb_inet_may_pull(struct sk_buff *skb) 343 { 344 int nhlen; 345 346 switch (skb->protocol) { 347 #if IS_ENABLED(CONFIG_IPV6) 348 case htons(ETH_P_IPV6): 349 nhlen = sizeof(struct ipv6hdr); 350 break; 351 #endif 352 case htons(ETH_P_IP): 353 nhlen = sizeof(struct iphdr); 354 break; 355 default: 356 nhlen = 0; 357 } 358 359 return pskb_network_may_pull(skb, nhlen); 360 } 361 362 static inline int ip_encap_hlen(struct ip_tunnel_encap *e) 363 { 364 const struct ip_tunnel_encap_ops *ops; 365 int hlen = -EINVAL; 366 367 if (e->type == TUNNEL_ENCAP_NONE) 368 return 0; 369 370 if (e->type >= MAX_IPTUN_ENCAP_OPS) 371 return -EINVAL; 372 373 rcu_read_lock(); 374 ops = rcu_dereference(iptun_encaps[e->type]); 375 if (likely(ops && ops->encap_hlen)) 376 hlen = ops->encap_hlen(e); 377 rcu_read_unlock(); 378 379 return hlen; 380 } 381 382 static inline int ip_tunnel_encap(struct sk_buff *skb, 383 struct ip_tunnel_encap *e, 384 u8 *protocol, struct flowi4 *fl4) 385 { 386 const struct ip_tunnel_encap_ops *ops; 387 int ret = -EINVAL; 388 389 if (e->type == TUNNEL_ENCAP_NONE) 390 return 0; 391 392 if (e->type >= MAX_IPTUN_ENCAP_OPS) 393 return -EINVAL; 394 395 rcu_read_lock(); 396 ops = rcu_dereference(iptun_encaps[e->type]); 397 if (likely(ops && ops->build_header)) 398 ret = ops->build_header(skb, e, protocol, fl4); 399 rcu_read_unlock(); 400 401 return ret; 402 } 403 404 /* Extract dsfield from inner protocol */ 405 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph, 406 const struct sk_buff *skb) 407 { 408 __be16 payload_protocol = skb_protocol(skb, true); 409 410 if (payload_protocol == htons(ETH_P_IP)) 411 return iph->tos; 412 else if (payload_protocol == htons(ETH_P_IPV6)) 413 return ipv6_get_dsfield((const struct ipv6hdr *)iph); 414 else 415 return 0; 416 } 417 418 static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph, 419 const struct sk_buff *skb) 420 { 421 __be16 payload_protocol = skb_protocol(skb, true); 422 423 if (payload_protocol == htons(ETH_P_IP)) 424 return iph->ttl; 425 else if (payload_protocol == htons(ETH_P_IPV6)) 426 return ((const struct ipv6hdr *)iph)->hop_limit; 427 else 428 return 0; 429 } 430 431 /* Propogate ECN bits out */ 432 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph, 433 const struct sk_buff *skb) 434 { 435 u8 inner = ip_tunnel_get_dsfield(iph, skb); 436 437 return INET_ECN_encapsulate(tos, inner); 438 } 439 440 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len, 441 __be16 inner_proto, bool raw_proto, bool xnet); 442 443 static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, 444 __be16 inner_proto, bool xnet) 445 { 446 return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet); 447 } 448 449 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb, 450 __be32 src, __be32 dst, u8 proto, 451 u8 tos, u8 ttl, __be16 df, bool xnet); 452 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md, 453 gfp_t flags); 454 int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst, 455 int headroom, bool reply); 456 457 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask); 458 459 static inline int iptunnel_pull_offloads(struct sk_buff *skb) 460 { 461 if (skb_is_gso(skb)) { 462 int err; 463 464 err = skb_unclone(skb, GFP_ATOMIC); 465 if (unlikely(err)) 466 return err; 467 skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >> 468 NETIF_F_GSO_SHIFT); 469 } 470 471 skb->encapsulation = 0; 472 return 0; 473 } 474 475 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len) 476 { 477 if (pkt_len > 0) { 478 struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats); 479 480 u64_stats_update_begin(&tstats->syncp); 481 u64_stats_add(&tstats->tx_bytes, pkt_len); 482 u64_stats_inc(&tstats->tx_packets); 483 u64_stats_update_end(&tstats->syncp); 484 put_cpu_ptr(tstats); 485 } else { 486 struct net_device_stats *err_stats = &dev->stats; 487 488 if (pkt_len < 0) { 489 err_stats->tx_errors++; 490 err_stats->tx_aborted_errors++; 491 } else { 492 err_stats->tx_dropped++; 493 } 494 } 495 } 496 497 static inline void ip_tunnel_info_opts_get(void *to, 498 const struct ip_tunnel_info *info) 499 { 500 memcpy(to, info + 1, info->options_len); 501 } 502 503 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info, 504 const void *from, int len, 505 __be16 flags) 506 { 507 info->options_len = len; 508 if (len > 0) { 509 memcpy(ip_tunnel_info_opts(info), from, len); 510 info->key.tun_flags |= flags; 511 } 512 } 513 514 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate) 515 { 516 return (struct ip_tunnel_info *)lwtstate->data; 517 } 518 519 DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt); 520 521 /* Returns > 0 if metadata should be collected */ 522 static inline int ip_tunnel_collect_metadata(void) 523 { 524 return static_branch_unlikely(&ip_tunnel_metadata_cnt); 525 } 526 527 void __init ip_tunnel_core_init(void); 528 529 void ip_tunnel_need_metadata(void); 530 void ip_tunnel_unneed_metadata(void); 531 532 #else /* CONFIG_INET */ 533 534 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate) 535 { 536 return NULL; 537 } 538 539 static inline void ip_tunnel_need_metadata(void) 540 { 541 } 542 543 static inline void ip_tunnel_unneed_metadata(void) 544 { 545 } 546 547 static inline void ip_tunnel_info_opts_get(void *to, 548 const struct ip_tunnel_info *info) 549 { 550 } 551 552 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info, 553 const void *from, int len, 554 __be16 flags) 555 { 556 info->options_len = 0; 557 } 558 559 #endif /* CONFIG_INET */ 560 561 #endif /* __NET_IP_TUNNELS_H */ 562