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 (FIELD_SIZEOF(struct ip_tunnel_key, u) - \
37 FIELD_SIZEOF(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((FIELD_SIZEOF(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
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)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
ip_tunnel_dst_cache_usable(const struct sk_buff * skb,const struct ip_tunnel_info * info)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
ip_tunnel_info_af(const struct ip_tunnel_info * tun_info)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
key32_to_tunnel_id(__be32 key)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. */
tunnel_id_to_key32(__be64 tun_id)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
ip_tunnel_init_flow(struct flowi4 * fl4,int proto,__be32 daddr,__be32 saddr,__be32 key,__u8 tos,int oif,__u32 mark,__u32 tun_inner_hash)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_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
273 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
274 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
275
276 void ip_tunnel_get_stats64(struct net_device *dev,
277 struct rtnl_link_stats64 *tot);
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 struct ip_tunnel_encap_ops {
293 size_t (*encap_hlen)(struct ip_tunnel_encap *e);
294 int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
295 u8 *protocol, struct flowi4 *fl4);
296 int (*err_handler)(struct sk_buff *skb, u32 info);
297 };
298
299 #define MAX_IPTUN_ENCAP_OPS 8
300
301 extern const struct ip_tunnel_encap_ops __rcu *
302 iptun_encaps[MAX_IPTUN_ENCAP_OPS];
303
304 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
305 unsigned int num);
306 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
307 unsigned int num);
308
309 int ip_tunnel_encap_setup(struct ip_tunnel *t,
310 struct ip_tunnel_encap *ipencap);
311
pskb_inet_may_pull(struct sk_buff * skb)312 static inline bool pskb_inet_may_pull(struct sk_buff *skb)
313 {
314 int nhlen;
315
316 switch (skb->protocol) {
317 #if IS_ENABLED(CONFIG_IPV6)
318 case htons(ETH_P_IPV6):
319 nhlen = sizeof(struct ipv6hdr);
320 break;
321 #endif
322 case htons(ETH_P_IP):
323 nhlen = sizeof(struct iphdr);
324 break;
325 default:
326 nhlen = 0;
327 }
328
329 return pskb_network_may_pull(skb, nhlen);
330 }
331
ip_encap_hlen(struct ip_tunnel_encap * e)332 static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
333 {
334 const struct ip_tunnel_encap_ops *ops;
335 int hlen = -EINVAL;
336
337 if (e->type == TUNNEL_ENCAP_NONE)
338 return 0;
339
340 if (e->type >= MAX_IPTUN_ENCAP_OPS)
341 return -EINVAL;
342
343 rcu_read_lock();
344 ops = rcu_dereference(iptun_encaps[e->type]);
345 if (likely(ops && ops->encap_hlen))
346 hlen = ops->encap_hlen(e);
347 rcu_read_unlock();
348
349 return hlen;
350 }
351
ip_tunnel_encap(struct sk_buff * skb,struct ip_tunnel * t,u8 * protocol,struct flowi4 * fl4)352 static inline int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
353 u8 *protocol, struct flowi4 *fl4)
354 {
355 const struct ip_tunnel_encap_ops *ops;
356 int ret = -EINVAL;
357
358 if (t->encap.type == TUNNEL_ENCAP_NONE)
359 return 0;
360
361 if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
362 return -EINVAL;
363
364 rcu_read_lock();
365 ops = rcu_dereference(iptun_encaps[t->encap.type]);
366 if (likely(ops && ops->build_header))
367 ret = ops->build_header(skb, &t->encap, protocol, fl4);
368 rcu_read_unlock();
369
370 return ret;
371 }
372
373 /* Extract dsfield from inner protocol */
ip_tunnel_get_dsfield(const struct iphdr * iph,const struct sk_buff * skb)374 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
375 const struct sk_buff *skb)
376 {
377 if (skb->protocol == htons(ETH_P_IP))
378 return iph->tos;
379 else if (skb->protocol == htons(ETH_P_IPV6))
380 return ipv6_get_dsfield((const struct ipv6hdr *)iph);
381 else
382 return 0;
383 }
384
ip_tunnel_get_ttl(const struct iphdr * iph,const struct sk_buff * skb)385 static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph,
386 const struct sk_buff *skb)
387 {
388 if (skb->protocol == htons(ETH_P_IP))
389 return iph->ttl;
390 else if (skb->protocol == htons(ETH_P_IPV6))
391 return ((const struct ipv6hdr *)iph)->hop_limit;
392 else
393 return 0;
394 }
395
396 /* Propogate ECN bits out */
ip_tunnel_ecn_encap(u8 tos,const struct iphdr * iph,const struct sk_buff * skb)397 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
398 const struct sk_buff *skb)
399 {
400 u8 inner = ip_tunnel_get_dsfield(iph, skb);
401
402 return INET_ECN_encapsulate(tos, inner);
403 }
404
405 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
406 __be16 inner_proto, bool raw_proto, bool xnet);
407
iptunnel_pull_header(struct sk_buff * skb,int hdr_len,__be16 inner_proto,bool xnet)408 static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
409 __be16 inner_proto, bool xnet)
410 {
411 return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
412 }
413
414 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
415 __be32 src, __be32 dst, u8 proto,
416 u8 tos, u8 ttl, __be16 df, bool xnet);
417 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
418 gfp_t flags);
419
420 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
421
iptunnel_pull_offloads(struct sk_buff * skb)422 static inline int iptunnel_pull_offloads(struct sk_buff *skb)
423 {
424 if (skb_is_gso(skb)) {
425 int err;
426
427 err = skb_unclone(skb, GFP_ATOMIC);
428 if (unlikely(err))
429 return err;
430 skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
431 NETIF_F_GSO_SHIFT);
432 }
433
434 skb->encapsulation = 0;
435 return 0;
436 }
437
iptunnel_xmit_stats(struct net_device * dev,int pkt_len)438 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
439 {
440 if (pkt_len > 0) {
441 struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
442
443 u64_stats_update_begin(&tstats->syncp);
444 tstats->tx_bytes += pkt_len;
445 tstats->tx_packets++;
446 u64_stats_update_end(&tstats->syncp);
447 put_cpu_ptr(tstats);
448 } else {
449 struct net_device_stats *err_stats = &dev->stats;
450
451 if (pkt_len < 0) {
452 err_stats->tx_errors++;
453 err_stats->tx_aborted_errors++;
454 } else {
455 err_stats->tx_dropped++;
456 }
457 }
458 }
459
ip_tunnel_info_opts(struct ip_tunnel_info * info)460 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
461 {
462 return info + 1;
463 }
464
ip_tunnel_info_opts_get(void * to,const struct ip_tunnel_info * info)465 static inline void ip_tunnel_info_opts_get(void *to,
466 const struct ip_tunnel_info *info)
467 {
468 memcpy(to, info + 1, info->options_len);
469 }
470
ip_tunnel_info_opts_set(struct ip_tunnel_info * info,const void * from,int len,__be16 flags)471 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
472 const void *from, int len,
473 __be16 flags)
474 {
475 memcpy(ip_tunnel_info_opts(info), from, len);
476 info->options_len = len;
477 info->key.tun_flags |= flags;
478 }
479
lwt_tun_info(struct lwtunnel_state * lwtstate)480 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
481 {
482 return (struct ip_tunnel_info *)lwtstate->data;
483 }
484
485 DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
486
487 /* Returns > 0 if metadata should be collected */
ip_tunnel_collect_metadata(void)488 static inline int ip_tunnel_collect_metadata(void)
489 {
490 return static_branch_unlikely(&ip_tunnel_metadata_cnt);
491 }
492
493 void __init ip_tunnel_core_init(void);
494
495 void ip_tunnel_need_metadata(void);
496 void ip_tunnel_unneed_metadata(void);
497
498 #else /* CONFIG_INET */
499
lwt_tun_info(struct lwtunnel_state * lwtstate)500 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
501 {
502 return NULL;
503 }
504
ip_tunnel_need_metadata(void)505 static inline void ip_tunnel_need_metadata(void)
506 {
507 }
508
ip_tunnel_unneed_metadata(void)509 static inline void ip_tunnel_unneed_metadata(void)
510 {
511 }
512
ip_tunnel_info_opts_get(void * to,const struct ip_tunnel_info * info)513 static inline void ip_tunnel_info_opts_get(void *to,
514 const struct ip_tunnel_info *info)
515 {
516 }
517
ip_tunnel_info_opts_set(struct ip_tunnel_info * info,const void * from,int len,__be16 flags)518 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
519 const void *from, int len,
520 __be16 flags)
521 {
522 info->options_len = 0;
523 info->key.tun_flags |= flags;
524 }
525
526 #endif /* CONFIG_INET */
527
528 #endif /* __NET_IP_TUNNELS_H */
529