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
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)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
ip_tunnel_dst_cache_usable(const struct sk_buff * skb,const struct ip_tunnel_info * info)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
ip_tunnel_info_af(const struct ip_tunnel_info * tun_info)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
key32_to_tunnel_id(__be32 key)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. */
tunnel_id_to_key32(__be64 tun_id)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
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)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_rcu(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
pskb_inet_may_pull(struct sk_buff * skb)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 */
skb_vlan_inet_prepare(struct sk_buff * skb,bool inner_proto_inherit)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
ip_encap_hlen(struct ip_tunnel_encap * e)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
ip_tunnel_encap(struct sk_buff * skb,struct ip_tunnel_encap * e,u8 * protocol,struct flowi4 * fl4)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 */
ip_tunnel_get_dsfield(const struct iphdr * iph,const struct sk_buff * skb)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
ip_tunnel_get_ttl(const struct iphdr * iph,const struct sk_buff * skb)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 */
ip_tunnel_ecn_encap(u8 tos,const struct iphdr * iph,const struct sk_buff * skb)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
iptunnel_pull_header(struct sk_buff * skb,int hdr_len,__be16 inner_proto,bool xnet)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
iptunnel_pull_offloads(struct sk_buff * skb)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
iptunnel_xmit_stats(struct net_device * dev,int pkt_len)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
ip_tunnel_info_opts_get(void * to,const struct ip_tunnel_info * info)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
ip_tunnel_info_opts_set(struct ip_tunnel_info * info,const void * from,int len,__be16 flags)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
lwt_tun_info(struct lwtunnel_state * lwtstate)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 */
ip_tunnel_collect_metadata(void)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
lwt_tun_info(struct lwtunnel_state * lwtstate)568 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
569 {
570 return NULL;
571 }
572
ip_tunnel_need_metadata(void)573 static inline void ip_tunnel_need_metadata(void)
574 {
575 }
576
ip_tunnel_unneed_metadata(void)577 static inline void ip_tunnel_unneed_metadata(void)
578 {
579 }
580
ip_tunnel_info_opts_get(void * to,const struct ip_tunnel_info * info)581 static inline void ip_tunnel_info_opts_get(void *to,
582 const struct ip_tunnel_info *info)
583 {
584 }
585
ip_tunnel_info_opts_set(struct ip_tunnel_info * info,const void * from,int len,__be16 flags)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