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
39struct 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
61struct 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
84struct 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
96struct ip_tunnel_6rd_parm {
97 struct in6_addr prefix;
98 __be32 relay_prefix;
99 u16 prefixlen;
100 u16 relay_prefixlen;
101};
102#endif
103
104struct 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
111struct metadata_dst;
112
113struct 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
159struct 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
174struct 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
182static 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
211static inline bool
212ip_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
225static 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
231static 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. */
241static 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
252static 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, ifindex: 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
278int ip_tunnel_init(struct net_device *dev);
279void ip_tunnel_uninit(struct net_device *dev);
280void ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
281struct net *ip_tunnel_get_link_net(const struct net_device *dev);
282int ip_tunnel_get_iflink(const struct net_device *dev);
283int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
284 struct rtnl_link_ops *ops, char *devname);
285
286void ip_tunnel_delete_nets(struct list_head *list_net, unsigned int id,
287 struct rtnl_link_ops *ops,
288 struct list_head *dev_to_kill);
289
290void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
291 const struct iphdr *tnl_params, const u8 protocol);
292void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
293 const u8 proto, int tunnel_hlen);
294int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
295int ip_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
296 void __user *data, int cmd);
297int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
298int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
299
300struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
301 int link, __be16 flags,
302 __be32 remote, __be32 local,
303 __be32 key);
304
305void ip_tunnel_md_udp_encap(struct sk_buff *skb, struct ip_tunnel_info *info);
306int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
307 const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
308 bool log_ecn_error);
309int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
310 struct ip_tunnel_parm *p, __u32 fwmark);
311int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
312 struct ip_tunnel_parm *p, __u32 fwmark);
313void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
314
315bool ip_tunnel_netlink_encap_parms(struct nlattr *data[],
316 struct ip_tunnel_encap *encap);
317
318void ip_tunnel_netlink_parms(struct nlattr *data[],
319 struct ip_tunnel_parm *parms);
320
321extern const struct header_ops ip_tunnel_header_ops;
322__be16 ip_tunnel_parse_protocol(const struct sk_buff *skb);
323
324struct ip_tunnel_encap_ops {
325 size_t (*encap_hlen)(struct ip_tunnel_encap *e);
326 int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
327 u8 *protocol, struct flowi4 *fl4);
328 int (*err_handler)(struct sk_buff *skb, u32 info);
329};
330
331#define MAX_IPTUN_ENCAP_OPS 8
332
333extern const struct ip_tunnel_encap_ops __rcu *
334 iptun_encaps[MAX_IPTUN_ENCAP_OPS];
335
336int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
337 unsigned int num);
338int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
339 unsigned int num);
340
341int ip_tunnel_encap_setup(struct ip_tunnel *t,
342 struct ip_tunnel_encap *ipencap);
343
344static inline bool pskb_inet_may_pull(struct sk_buff *skb)
345{
346 int nhlen;
347
348 switch (skb->protocol) {
349#if IS_ENABLED(CONFIG_IPV6)
350 case htons(ETH_P_IPV6):
351 nhlen = sizeof(struct ipv6hdr);
352 break;
353#endif
354 case htons(ETH_P_IP):
355 nhlen = sizeof(struct iphdr);
356 break;
357 default:
358 nhlen = 0;
359 }
360
361 return pskb_network_may_pull(skb, len: nhlen);
362}
363
364/* Variant of pskb_inet_may_pull().
365 */
366static inline bool skb_vlan_inet_prepare(struct sk_buff *skb)
367{
368 int nhlen = 0, maclen = 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(ethertype: type))
375 type = __vlan_get_protocol(skb, type, depth: &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, len: maclen + nhlen))
391 return false;
392
393 skb_set_network_header(skb, offset: maclen);
394 return true;
395}
396
397static 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
417static 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 */
440static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
441 const struct sk_buff *skb)
442{
443 __be16 payload_protocol = skb_protocol(skb, skip_vlan: 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(ipv6h: (const struct ipv6hdr *)iph);
449 else
450 return 0;
451}
452
453static inline __be32 ip_tunnel_get_flowlabel(const struct iphdr *iph,
454 const struct sk_buff *skb)
455{
456 __be16 payload_protocol = skb_protocol(skb, skip_vlan: true);
457
458 if (payload_protocol == htons(ETH_P_IPV6))
459 return ip6_flowlabel(hdr: (const struct ipv6hdr *)iph);
460 else
461 return 0;
462}
463
464static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph,
465 const struct sk_buff *skb)
466{
467 __be16 payload_protocol = skb_protocol(skb, skip_vlan: true);
468
469 if (payload_protocol == htons(ETH_P_IP))
470 return iph->ttl;
471 else if (payload_protocol == htons(ETH_P_IPV6))
472 return ((const struct ipv6hdr *)iph)->hop_limit;
473 else
474 return 0;
475}
476
477/* Propogate ECN bits out */
478static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
479 const struct sk_buff *skb)
480{
481 u8 inner = ip_tunnel_get_dsfield(iph, skb);
482
483 return INET_ECN_encapsulate(outer: tos, inner);
484}
485
486int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
487 __be16 inner_proto, bool raw_proto, bool xnet);
488
489static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
490 __be16 inner_proto, bool xnet)
491{
492 return __iptunnel_pull_header(skb, hdr_len, inner_proto, raw_proto: false, xnet);
493}
494
495void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
496 __be32 src, __be32 dst, u8 proto,
497 u8 tos, u8 ttl, __be16 df, bool xnet);
498struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
499 gfp_t flags);
500int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst,
501 int headroom, bool reply);
502
503int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
504
505static inline int iptunnel_pull_offloads(struct sk_buff *skb)
506{
507 if (skb_is_gso(skb)) {
508 int err;
509
510 err = skb_unclone(skb, GFP_ATOMIC);
511 if (unlikely(err))
512 return err;
513 skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
514 NETIF_F_GSO_SHIFT);
515 }
516
517 skb->encapsulation = 0;
518 return 0;
519}
520
521static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
522{
523 if (pkt_len > 0) {
524 struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
525
526 u64_stats_update_begin(syncp: &tstats->syncp);
527 u64_stats_add(p: &tstats->tx_bytes, val: pkt_len);
528 u64_stats_inc(p: &tstats->tx_packets);
529 u64_stats_update_end(syncp: &tstats->syncp);
530 put_cpu_ptr(tstats);
531 return;
532 }
533
534 if (pkt_len < 0) {
535 DEV_STATS_INC(dev, tx_errors);
536 DEV_STATS_INC(dev, tx_aborted_errors);
537 } else {
538 DEV_STATS_INC(dev, tx_dropped);
539 }
540}
541
542static inline void ip_tunnel_info_opts_get(void *to,
543 const struct ip_tunnel_info *info)
544{
545 memcpy(to, info + 1, info->options_len);
546}
547
548static 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 = len;
553 if (len > 0) {
554 memcpy(ip_tunnel_info_opts(info), from, len);
555 info->key.tun_flags |= flags;
556 }
557}
558
559static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
560{
561 return (struct ip_tunnel_info *)lwtstate->data;
562}
563
564DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
565
566/* Returns > 0 if metadata should be collected */
567static inline int ip_tunnel_collect_metadata(void)
568{
569 return static_branch_unlikely(&ip_tunnel_metadata_cnt);
570}
571
572void __init ip_tunnel_core_init(void);
573
574void ip_tunnel_need_metadata(void);
575void ip_tunnel_unneed_metadata(void);
576
577#else /* CONFIG_INET */
578
579static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
580{
581 return NULL;
582}
583
584static inline void ip_tunnel_need_metadata(void)
585{
586}
587
588static inline void ip_tunnel_unneed_metadata(void)
589{
590}
591
592static inline void ip_tunnel_info_opts_get(void *to,
593 const struct ip_tunnel_info *info)
594{
595}
596
597static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
598 const void *from, int len,
599 __be16 flags)
600{
601 info->options_len = 0;
602}
603
604#endif /* CONFIG_INET */
605
606#endif /* __NET_IP_TUNNELS_H */
607

source code of linux/include/net/ip_tunnels.h