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