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 atomic_t 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 #define TUNNEL_CSUM __cpu_to_be16(0x01)
148 #define TUNNEL_ROUTING __cpu_to_be16(0x02)
149 #define TUNNEL_KEY __cpu_to_be16(0x04)
150 #define TUNNEL_SEQ __cpu_to_be16(0x08)
151 #define TUNNEL_STRICT __cpu_to_be16(0x10)
152 #define TUNNEL_REC __cpu_to_be16(0x20)
153 #define TUNNEL_VERSION __cpu_to_be16(0x40)
154 #define TUNNEL_NO_KEY __cpu_to_be16(0x80)
155 #define TUNNEL_DONT_FRAGMENT __cpu_to_be16(0x0100)
156 #define TUNNEL_OAM __cpu_to_be16(0x0200)
157 #define TUNNEL_CRIT_OPT __cpu_to_be16(0x0400)
158 #define TUNNEL_GENEVE_OPT __cpu_to_be16(0x0800)
159 #define TUNNEL_VXLAN_OPT __cpu_to_be16(0x1000)
160 #define TUNNEL_NOCACHE __cpu_to_be16(0x2000)
161 #define TUNNEL_ERSPAN_OPT __cpu_to_be16(0x4000)
162
163 #define TUNNEL_OPTIONS_PRESENT \
164 (TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT | TUNNEL_ERSPAN_OPT)
165
166 struct tnl_ptk_info {
167 __be16 flags;
168 __be16 proto;
169 __be32 key;
170 __be32 seq;
171 int hdr_len;
172 };
173
174 #define PACKET_RCVD 0
175 #define PACKET_REJECT 1
176 #define PACKET_NEXT 2
177
178 #define IP_TNL_HASH_BITS 7
179 #define IP_TNL_HASH_SIZE (1 << IP_TNL_HASH_BITS)
180
181 struct ip_tunnel_net {
182 struct net_device *fb_tunnel_dev;
183 struct rtnl_link_ops *rtnl_link_ops;
184 struct hlist_head tunnels[IP_TNL_HASH_SIZE];
185 struct ip_tunnel __rcu *collect_md_tun;
186 int type;
187 };
188
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)189 static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
190 __be32 saddr, __be32 daddr,
191 u8 tos, u8 ttl, __be32 label,
192 __be16 tp_src, __be16 tp_dst,
193 __be64 tun_id, __be16 tun_flags)
194 {
195 key->tun_id = tun_id;
196 key->u.ipv4.src = saddr;
197 key->u.ipv4.dst = daddr;
198 memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
199 0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
200 key->tos = tos;
201 key->ttl = ttl;
202 key->label = label;
203 key->tun_flags = tun_flags;
204
205 /* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
206 * the upper tunnel are used.
207 * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
208 */
209 key->tp_src = tp_src;
210 key->tp_dst = tp_dst;
211
212 /* Clear struct padding. */
213 if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
214 memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
215 0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
216 }
217
218 static inline bool
ip_tunnel_dst_cache_usable(const struct sk_buff * skb,const struct ip_tunnel_info * info)219 ip_tunnel_dst_cache_usable(const struct sk_buff *skb,
220 const struct ip_tunnel_info *info)
221 {
222 if (skb->mark)
223 return false;
224 if (!info)
225 return true;
226 if (info->key.tun_flags & TUNNEL_NOCACHE)
227 return false;
228
229 return true;
230 }
231
ip_tunnel_info_af(const struct ip_tunnel_info * tun_info)232 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
233 *tun_info)
234 {
235 return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
236 }
237
key32_to_tunnel_id(__be32 key)238 static inline __be64 key32_to_tunnel_id(__be32 key)
239 {
240 #ifdef __BIG_ENDIAN
241 return (__force __be64)key;
242 #else
243 return (__force __be64)((__force u64)key << 32);
244 #endif
245 }
246
247 /* Returns the least-significant 32 bits of a __be64. */
tunnel_id_to_key32(__be64 tun_id)248 static inline __be32 tunnel_id_to_key32(__be64 tun_id)
249 {
250 #ifdef __BIG_ENDIAN
251 return (__force __be32)tun_id;
252 #else
253 return (__force __be32)((__force u64)tun_id >> 32);
254 #endif
255 }
256
257 #ifdef CONFIG_INET
258
ip_tunnel_init_flow(struct flowi4 * fl4,int proto,__be32 daddr,__be32 saddr,__be32 key,__u8 tos,int oif,__u32 mark)259 static inline void ip_tunnel_init_flow(struct flowi4 *fl4,
260 int proto,
261 __be32 daddr, __be32 saddr,
262 __be32 key, __u8 tos, int oif,
263 __u32 mark)
264 {
265 memset(fl4, 0, sizeof(*fl4));
266 fl4->flowi4_oif = oif;
267 fl4->daddr = daddr;
268 fl4->saddr = saddr;
269 fl4->flowi4_tos = tos;
270 fl4->flowi4_proto = proto;
271 fl4->fl4_gre_key = key;
272 fl4->flowi4_mark = mark;
273 }
274
275 int ip_tunnel_init(struct net_device *dev);
276 void ip_tunnel_uninit(struct net_device *dev);
277 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
278 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
279 int ip_tunnel_get_iflink(const struct net_device *dev);
280 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
281 struct rtnl_link_ops *ops, char *devname);
282
283 void ip_tunnel_delete_nets(struct list_head *list_net, unsigned int id,
284 struct rtnl_link_ops *ops);
285
286 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
287 const struct iphdr *tnl_params, const u8 protocol);
288 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
289 const u8 proto);
290 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
291 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
292 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
293
294 void ip_tunnel_get_stats64(struct net_device *dev,
295 struct rtnl_link_stats64 *tot);
296 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
297 int link, __be16 flags,
298 __be32 remote, __be32 local,
299 __be32 key);
300
301 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
302 const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
303 bool log_ecn_error);
304 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
305 struct ip_tunnel_parm *p, __u32 fwmark);
306 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
307 struct ip_tunnel_parm *p, __u32 fwmark);
308 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
309
310 struct ip_tunnel_encap_ops {
311 size_t (*encap_hlen)(struct ip_tunnel_encap *e);
312 int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
313 u8 *protocol, struct flowi4 *fl4);
314 };
315
316 #define MAX_IPTUN_ENCAP_OPS 8
317
318 extern const struct ip_tunnel_encap_ops __rcu *
319 iptun_encaps[MAX_IPTUN_ENCAP_OPS];
320
321 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
322 unsigned int num);
323 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
324 unsigned int num);
325
326 int ip_tunnel_encap_setup(struct ip_tunnel *t,
327 struct ip_tunnel_encap *ipencap);
328
pskb_inet_may_pull(struct sk_buff * skb)329 static inline bool pskb_inet_may_pull(struct sk_buff *skb)
330 {
331 int nhlen;
332
333 switch (skb->protocol) {
334 #if IS_ENABLED(CONFIG_IPV6)
335 case htons(ETH_P_IPV6):
336 nhlen = sizeof(struct ipv6hdr);
337 break;
338 #endif
339 case htons(ETH_P_IP):
340 nhlen = sizeof(struct iphdr);
341 break;
342 default:
343 nhlen = 0;
344 }
345
346 return pskb_network_may_pull(skb, nhlen);
347 }
348
ip_encap_hlen(struct ip_tunnel_encap * e)349 static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
350 {
351 const struct ip_tunnel_encap_ops *ops;
352 int hlen = -EINVAL;
353
354 if (e->type == TUNNEL_ENCAP_NONE)
355 return 0;
356
357 if (e->type >= MAX_IPTUN_ENCAP_OPS)
358 return -EINVAL;
359
360 rcu_read_lock();
361 ops = rcu_dereference(iptun_encaps[e->type]);
362 if (likely(ops && ops->encap_hlen))
363 hlen = ops->encap_hlen(e);
364 rcu_read_unlock();
365
366 return hlen;
367 }
368
ip_tunnel_encap(struct sk_buff * skb,struct ip_tunnel * t,u8 * protocol,struct flowi4 * fl4)369 static inline int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
370 u8 *protocol, struct flowi4 *fl4)
371 {
372 const struct ip_tunnel_encap_ops *ops;
373 int ret = -EINVAL;
374
375 if (t->encap.type == TUNNEL_ENCAP_NONE)
376 return 0;
377
378 if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
379 return -EINVAL;
380
381 rcu_read_lock();
382 ops = rcu_dereference(iptun_encaps[t->encap.type]);
383 if (likely(ops && ops->build_header))
384 ret = ops->build_header(skb, &t->encap, protocol, fl4);
385 rcu_read_unlock();
386
387 return ret;
388 }
389
390 /* Extract dsfield from inner protocol */
ip_tunnel_get_dsfield(const struct iphdr * iph,const struct sk_buff * skb)391 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
392 const struct sk_buff *skb)
393 {
394 if (skb->protocol == htons(ETH_P_IP))
395 return iph->tos;
396 else if (skb->protocol == htons(ETH_P_IPV6))
397 return ipv6_get_dsfield((const struct ipv6hdr *)iph);
398 else
399 return 0;
400 }
401
ip_tunnel_get_ttl(const struct iphdr * iph,const struct sk_buff * skb)402 static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph,
403 const struct sk_buff *skb)
404 {
405 if (skb->protocol == htons(ETH_P_IP))
406 return iph->ttl;
407 else if (skb->protocol == htons(ETH_P_IPV6))
408 return ((const struct ipv6hdr *)iph)->hop_limit;
409 else
410 return 0;
411 }
412
413 /* Propogate ECN bits out */
ip_tunnel_ecn_encap(u8 tos,const struct iphdr * iph,const struct sk_buff * skb)414 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
415 const struct sk_buff *skb)
416 {
417 u8 inner = ip_tunnel_get_dsfield(iph, skb);
418
419 return INET_ECN_encapsulate(tos, inner);
420 }
421
422 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
423 __be16 inner_proto, bool raw_proto, bool xnet);
424
iptunnel_pull_header(struct sk_buff * skb,int hdr_len,__be16 inner_proto,bool xnet)425 static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
426 __be16 inner_proto, bool xnet)
427 {
428 return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
429 }
430
431 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
432 __be32 src, __be32 dst, u8 proto,
433 u8 tos, u8 ttl, __be16 df, bool xnet);
434 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
435 gfp_t flags);
436
437 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
438
iptunnel_pull_offloads(struct sk_buff * skb)439 static inline int iptunnel_pull_offloads(struct sk_buff *skb)
440 {
441 if (skb_is_gso(skb)) {
442 int err;
443
444 err = skb_unclone(skb, GFP_ATOMIC);
445 if (unlikely(err))
446 return err;
447 skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
448 NETIF_F_GSO_SHIFT);
449 }
450
451 skb->encapsulation = 0;
452 return 0;
453 }
454
iptunnel_xmit_stats(struct net_device * dev,int pkt_len)455 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
456 {
457 if (pkt_len > 0) {
458 struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
459
460 u64_stats_update_begin(&tstats->syncp);
461 tstats->tx_bytes += pkt_len;
462 tstats->tx_packets++;
463 u64_stats_update_end(&tstats->syncp);
464 put_cpu_ptr(tstats);
465 } else {
466 struct net_device_stats *err_stats = &dev->stats;
467
468 if (pkt_len < 0) {
469 err_stats->tx_errors++;
470 err_stats->tx_aborted_errors++;
471 } else {
472 err_stats->tx_dropped++;
473 }
474 }
475 }
476
ip_tunnel_info_opts(struct ip_tunnel_info * info)477 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
478 {
479 return info + 1;
480 }
481
ip_tunnel_info_opts_get(void * to,const struct ip_tunnel_info * info)482 static inline void ip_tunnel_info_opts_get(void *to,
483 const struct ip_tunnel_info *info)
484 {
485 memcpy(to, info + 1, info->options_len);
486 }
487
ip_tunnel_info_opts_set(struct ip_tunnel_info * info,const void * from,int len,__be16 flags)488 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
489 const void *from, int len,
490 __be16 flags)
491 {
492 info->options_len = len;
493 if (len > 0) {
494 memcpy(ip_tunnel_info_opts(info), from, len);
495 info->key.tun_flags |= flags;
496 }
497 }
498
lwt_tun_info(struct lwtunnel_state * lwtstate)499 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
500 {
501 return (struct ip_tunnel_info *)lwtstate->data;
502 }
503
504 DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
505
506 /* Returns > 0 if metadata should be collected */
ip_tunnel_collect_metadata(void)507 static inline int ip_tunnel_collect_metadata(void)
508 {
509 return static_branch_unlikely(&ip_tunnel_metadata_cnt);
510 }
511
512 void __init ip_tunnel_core_init(void);
513
514 void ip_tunnel_need_metadata(void);
515 void ip_tunnel_unneed_metadata(void);
516
517 #else /* CONFIG_INET */
518
lwt_tun_info(struct lwtunnel_state * lwtstate)519 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
520 {
521 return NULL;
522 }
523
ip_tunnel_need_metadata(void)524 static inline void ip_tunnel_need_metadata(void)
525 {
526 }
527
ip_tunnel_unneed_metadata(void)528 static inline void ip_tunnel_unneed_metadata(void)
529 {
530 }
531
ip_tunnel_info_opts_get(void * to,const struct ip_tunnel_info * info)532 static inline void ip_tunnel_info_opts_get(void *to,
533 const struct ip_tunnel_info *info)
534 {
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 = 0;
542 }
543
544 #endif /* CONFIG_INET */
545
546 #endif /* __NET_IP_TUNNELS_H */
547