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 __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
70struct 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
81struct ip_tunnel_6rd_parm {
82 struct in6_addr prefix;
83 __be32 relay_prefix;
84 u16 prefixlen;
85 u16 relay_prefixlen;
86};
87#endif
88
89struct ip_tunnel_encap {
90 u16 type;
91 u16 flags;
92 __be16 sport;
93 __be16 dport;
94};
95
96struct 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
103struct metadata_dst;
104
105struct 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
151struct 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
166struct 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
174static 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
203static inline bool
204ip_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
217static 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
223static 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. */
233static 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
244static 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{
251 memset(fl4, 0, sizeof(*fl4));
252
253 if (oif) {
254 fl4->flowi4_l3mdev = l3mdev_master_upper_ifindex_by_index_rcu(net, oif);
255 /* Legacy VRF/l3mdev use case */
256 fl4->flowi4_oif = fl4->flowi4_l3mdev ? 0 : oif;
257 }
258
259 fl4->daddr = daddr;
260 fl4->saddr = saddr;
261 fl4->flowi4_tos = tos;
262 fl4->flowi4_proto = proto;
263 fl4->fl4_gre_key = key;
264 fl4->flowi4_mark = mark;
265 fl4->flowi4_multipath_hash = tun_inner_hash;
266}
267
268int ip_tunnel_init(struct net_device *dev);
269void ip_tunnel_uninit(struct net_device *dev);
270void ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
271struct net *ip_tunnel_get_link_net(const struct net_device *dev);
272int ip_tunnel_get_iflink(const struct net_device *dev);
273int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
274 struct rtnl_link_ops *ops, char *devname);
275
276void ip_tunnel_delete_nets(struct list_head *list_net, unsigned int id,
277 struct rtnl_link_ops *ops);
278
279void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
280 const struct iphdr *tnl_params, const u8 protocol);
281void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
282 const u8 proto, int tunnel_hlen);
283int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
284int ip_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
285 void __user *data, int cmd);
286int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
287int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
288
289struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
290 int link, __be16 flags,
291 __be32 remote, __be32 local,
292 __be32 key);
293
294int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
295 const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
296 bool log_ecn_error);
297int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
298 struct ip_tunnel_parm *p, __u32 fwmark);
299int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
300 struct ip_tunnel_parm *p, __u32 fwmark);
301void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
302
303extern const struct header_ops ip_tunnel_header_ops;
304__be16 ip_tunnel_parse_protocol(const struct sk_buff *skb);
305
306struct ip_tunnel_encap_ops {
307 size_t (*encap_hlen)(struct ip_tunnel_encap *e);
308 int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
309 u8 *protocol, struct flowi4 *fl4);
310 int (*err_handler)(struct sk_buff *skb, u32 info);
311};
312
313#define MAX_IPTUN_ENCAP_OPS 8
314
315extern const struct ip_tunnel_encap_ops __rcu *
316 iptun_encaps[MAX_IPTUN_ENCAP_OPS];
317
318int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
319 unsigned int num);
320int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
321 unsigned int num);
322
323int ip_tunnel_encap_setup(struct ip_tunnel *t,
324 struct ip_tunnel_encap *ipencap);
325
326static inline bool pskb_inet_may_pull(struct sk_buff *skb)
327{
328 int nhlen;
329
330 switch (skb->protocol) {
331#if IS_ENABLED(CONFIG_IPV6)
332 case htons(ETH_P_IPV6):
333 nhlen = sizeof(struct ipv6hdr);
334 break;
335#endif
336 case htons(ETH_P_IP):
337 nhlen = sizeof(struct iphdr);
338 break;
339 default:
340 nhlen = 0;
341 }
342
343 return pskb_network_may_pull(skb, nhlen);
344}
345
346static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
347{
348 const struct ip_tunnel_encap_ops *ops;
349 int hlen = -EINVAL;
350
351 if (e->type == TUNNEL_ENCAP_NONE)
352 return 0;
353
354 if (e->type >= MAX_IPTUN_ENCAP_OPS)
355 return -EINVAL;
356
357 rcu_read_lock();
358 ops = rcu_dereference(iptun_encaps[e->type]);
359 if (likely(ops && ops->encap_hlen))
360 hlen = ops->encap_hlen(e);
361 rcu_read_unlock();
362
363 return hlen;
364}
365
366static inline int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
367 u8 *protocol, struct flowi4 *fl4)
368{
369 const struct ip_tunnel_encap_ops *ops;
370 int ret = -EINVAL;
371
372 if (t->encap.type == TUNNEL_ENCAP_NONE)
373 return 0;
374
375 if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
376 return -EINVAL;
377
378 rcu_read_lock();
379 ops = rcu_dereference(iptun_encaps[t->encap.type]);
380 if (likely(ops && ops->build_header))
381 ret = ops->build_header(skb, &t->encap, protocol, fl4);
382 rcu_read_unlock();
383
384 return ret;
385}
386
387/* Extract dsfield from inner protocol */
388static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
389 const struct sk_buff *skb)
390{
391 __be16 payload_protocol = skb_protocol(skb, true);
392
393 if (payload_protocol == htons(ETH_P_IP))
394 return iph->tos;
395 else if (payload_protocol == htons(ETH_P_IPV6))
396 return ipv6_get_dsfield((const struct ipv6hdr *)iph);
397 else
398 return 0;
399}
400
401static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph,
402 const struct sk_buff *skb)
403{
404 __be16 payload_protocol = skb_protocol(skb, true);
405
406 if (payload_protocol == htons(ETH_P_IP))
407 return iph->ttl;
408 else if (payload_protocol == htons(ETH_P_IPV6))
409 return ((const struct ipv6hdr *)iph)->hop_limit;
410 else
411 return 0;
412}
413
414/* Propogate ECN bits out */
415static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
416 const struct sk_buff *skb)
417{
418 u8 inner = ip_tunnel_get_dsfield(iph, skb);
419
420 return INET_ECN_encapsulate(tos, inner);
421}
422
423int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
424 __be16 inner_proto, bool raw_proto, bool xnet);
425
426static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
427 __be16 inner_proto, bool xnet)
428{
429 return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
430}
431
432void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
433 __be32 src, __be32 dst, u8 proto,
434 u8 tos, u8 ttl, __be16 df, bool xnet);
435struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
436 gfp_t flags);
437int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst,
438 int headroom, bool reply);
439
440int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
441
442static inline int iptunnel_pull_offloads(struct sk_buff *skb)
443{
444 if (skb_is_gso(skb)) {
445 int err;
446
447 err = skb_unclone(skb, GFP_ATOMIC);
448 if (unlikely(err))
449 return err;
450 skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
451 NETIF_F_GSO_SHIFT);
452 }
453
454 skb->encapsulation = 0;
455 return 0;
456}
457
458static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
459{
460 if (pkt_len > 0) {
461 struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
462
463 u64_stats_update_begin(&tstats->syncp);
464 u64_stats_add(&tstats->tx_bytes, pkt_len);
465 u64_stats_inc(&tstats->tx_packets);
466 u64_stats_update_end(&tstats->syncp);
467 put_cpu_ptr(tstats);
468 } else {
469 struct net_device_stats *err_stats = &dev->stats;
470
471 if (pkt_len < 0) {
472 err_stats->tx_errors++;
473 err_stats->tx_aborted_errors++;
474 } else {
475 err_stats->tx_dropped++;
476 }
477 }
478}
479
480static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
481{
482 return info + 1;
483}
484
485static inline void ip_tunnel_info_opts_get(void *to,
486 const struct ip_tunnel_info *info)
487{
488 memcpy(to, info + 1, info->options_len);
489}
490
491static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
492 const void *from, int len,
493 __be16 flags)
494{
495 info->options_len = len;
496 if (len > 0) {
497 memcpy(ip_tunnel_info_opts(info), from, len);
498 info->key.tun_flags |= flags;
499 }
500}
501
502static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
503{
504 return (struct ip_tunnel_info *)lwtstate->data;
505}
506
507DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
508
509/* Returns > 0 if metadata should be collected */
510static inline int ip_tunnel_collect_metadata(void)
511{
512 return static_branch_unlikely(&ip_tunnel_metadata_cnt);
513}
514
515void __init ip_tunnel_core_init(void);
516
517void ip_tunnel_need_metadata(void);
518void ip_tunnel_unneed_metadata(void);
519
520#else /* CONFIG_INET */
521
522static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
523{
524 return NULL;
525}
526
527static inline void ip_tunnel_need_metadata(void)
528{
529}
530
531static inline void ip_tunnel_unneed_metadata(void)
532{
533}
534
535static inline void ip_tunnel_info_opts_get(void *to,
536 const struct ip_tunnel_info *info)
537{
538}
539
540static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
541 const void *from, int len,
542 __be16 flags)
543{
544 info->options_len = 0;
545}
546
547#endif /* CONFIG_INET */
548
549#endif /* __NET_IP_TUNNELS_H */
550

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