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