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 __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((sizeof_field(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 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_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
273 int ip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
274 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
275 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
276
277 void ip_tunnel_get_stats64(struct net_device *dev,
278 struct rtnl_link_stats64 *tot);
279 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
280 int link, __be16 flags,
281 __be32 remote, __be32 local,
282 __be32 key);
283
284 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
285 const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
286 bool log_ecn_error);
287 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
288 struct ip_tunnel_parm *p, __u32 fwmark);
289 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
290 struct ip_tunnel_parm *p, __u32 fwmark);
291 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
292
293 extern const struct header_ops ip_tunnel_header_ops;
294 __be16 ip_tunnel_parse_protocol(const struct sk_buff *skb);
295
296 struct ip_tunnel_encap_ops {
297 size_t (*encap_hlen)(struct ip_tunnel_encap *e);
298 int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
299 u8 *protocol, struct flowi4 *fl4);
300 int (*err_handler)(struct sk_buff *skb, u32 info);
301 };
302
303 #define MAX_IPTUN_ENCAP_OPS 8
304
305 extern const struct ip_tunnel_encap_ops __rcu *
306 iptun_encaps[MAX_IPTUN_ENCAP_OPS];
307
308 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
309 unsigned int num);
310 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
311 unsigned int num);
312
313 int ip_tunnel_encap_setup(struct ip_tunnel *t,
314 struct ip_tunnel_encap *ipencap);
315
pskb_inet_may_pull(struct sk_buff * skb)316 static inline bool pskb_inet_may_pull(struct sk_buff *skb)
317 {
318 int nhlen;
319
320 switch (skb->protocol) {
321 #if IS_ENABLED(CONFIG_IPV6)
322 case htons(ETH_P_IPV6):
323 nhlen = sizeof(struct ipv6hdr);
324 break;
325 #endif
326 case htons(ETH_P_IP):
327 nhlen = sizeof(struct iphdr);
328 break;
329 default:
330 nhlen = 0;
331 }
332
333 return pskb_network_may_pull(skb, nhlen);
334 }
335
ip_encap_hlen(struct ip_tunnel_encap * e)336 static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
337 {
338 const struct ip_tunnel_encap_ops *ops;
339 int hlen = -EINVAL;
340
341 if (e->type == TUNNEL_ENCAP_NONE)
342 return 0;
343
344 if (e->type >= MAX_IPTUN_ENCAP_OPS)
345 return -EINVAL;
346
347 rcu_read_lock();
348 ops = rcu_dereference(iptun_encaps[e->type]);
349 if (likely(ops && ops->encap_hlen))
350 hlen = ops->encap_hlen(e);
351 rcu_read_unlock();
352
353 return hlen;
354 }
355
ip_tunnel_encap(struct sk_buff * skb,struct ip_tunnel * t,u8 * protocol,struct flowi4 * fl4)356 static inline int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
357 u8 *protocol, struct flowi4 *fl4)
358 {
359 const struct ip_tunnel_encap_ops *ops;
360 int ret = -EINVAL;
361
362 if (t->encap.type == TUNNEL_ENCAP_NONE)
363 return 0;
364
365 if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
366 return -EINVAL;
367
368 rcu_read_lock();
369 ops = rcu_dereference(iptun_encaps[t->encap.type]);
370 if (likely(ops && ops->build_header))
371 ret = ops->build_header(skb, &t->encap, protocol, fl4);
372 rcu_read_unlock();
373
374 return ret;
375 }
376
377 /* Extract dsfield from inner protocol */
ip_tunnel_get_dsfield(const struct iphdr * iph,const struct sk_buff * skb)378 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
379 const struct sk_buff *skb)
380 {
381 __be16 payload_protocol = skb_protocol(skb, true);
382
383 if (payload_protocol == htons(ETH_P_IP))
384 return iph->tos;
385 else if (payload_protocol == htons(ETH_P_IPV6))
386 return ipv6_get_dsfield((const struct ipv6hdr *)iph);
387 else
388 return 0;
389 }
390
ip_tunnel_get_ttl(const struct iphdr * iph,const struct sk_buff * skb)391 static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph,
392 const struct sk_buff *skb)
393 {
394 __be16 payload_protocol = skb_protocol(skb, true);
395
396 if (payload_protocol == htons(ETH_P_IP))
397 return iph->ttl;
398 else if (payload_protocol == htons(ETH_P_IPV6))
399 return ((const struct ipv6hdr *)iph)->hop_limit;
400 else
401 return 0;
402 }
403
404 /* Propogate ECN bits out */
ip_tunnel_ecn_encap(u8 tos,const struct iphdr * iph,const struct sk_buff * skb)405 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
406 const struct sk_buff *skb)
407 {
408 u8 inner = ip_tunnel_get_dsfield(iph, skb);
409
410 return INET_ECN_encapsulate(tos, inner);
411 }
412
413 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
414 __be16 inner_proto, bool raw_proto, bool xnet);
415
iptunnel_pull_header(struct sk_buff * skb,int hdr_len,__be16 inner_proto,bool xnet)416 static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
417 __be16 inner_proto, bool xnet)
418 {
419 return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
420 }
421
422 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
423 __be32 src, __be32 dst, u8 proto,
424 u8 tos, u8 ttl, __be16 df, bool xnet);
425 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
426 gfp_t flags);
427 int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst,
428 int headroom, bool reply);
429
430 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
431
iptunnel_pull_offloads(struct sk_buff * skb)432 static inline int iptunnel_pull_offloads(struct sk_buff *skb)
433 {
434 if (skb_is_gso(skb)) {
435 int err;
436
437 err = skb_unclone(skb, GFP_ATOMIC);
438 if (unlikely(err))
439 return err;
440 skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
441 NETIF_F_GSO_SHIFT);
442 }
443
444 skb->encapsulation = 0;
445 return 0;
446 }
447
iptunnel_xmit_stats(struct net_device * dev,int pkt_len)448 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
449 {
450 if (pkt_len > 0) {
451 struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
452
453 u64_stats_update_begin(&tstats->syncp);
454 tstats->tx_bytes += pkt_len;
455 tstats->tx_packets++;
456 u64_stats_update_end(&tstats->syncp);
457 put_cpu_ptr(tstats);
458 } else {
459 struct net_device_stats *err_stats = &dev->stats;
460
461 if (pkt_len < 0) {
462 err_stats->tx_errors++;
463 err_stats->tx_aborted_errors++;
464 } else {
465 err_stats->tx_dropped++;
466 }
467 }
468 }
469
ip_tunnel_info_opts(struct ip_tunnel_info * info)470 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
471 {
472 return info + 1;
473 }
474
ip_tunnel_info_opts_get(void * to,const struct ip_tunnel_info * info)475 static inline void ip_tunnel_info_opts_get(void *to,
476 const struct ip_tunnel_info *info)
477 {
478 memcpy(to, info + 1, info->options_len);
479 }
480
ip_tunnel_info_opts_set(struct ip_tunnel_info * info,const void * from,int len,__be16 flags)481 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
482 const void *from, int len,
483 __be16 flags)
484 {
485 info->options_len = len;
486 if (len > 0) {
487 memcpy(ip_tunnel_info_opts(info), from, len);
488 info->key.tun_flags |= flags;
489 }
490 }
491
lwt_tun_info(struct lwtunnel_state * lwtstate)492 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
493 {
494 return (struct ip_tunnel_info *)lwtstate->data;
495 }
496
497 DECLARE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
498
499 /* Returns > 0 if metadata should be collected */
ip_tunnel_collect_metadata(void)500 static inline int ip_tunnel_collect_metadata(void)
501 {
502 return static_branch_unlikely(&ip_tunnel_metadata_cnt);
503 }
504
505 void __init ip_tunnel_core_init(void);
506
507 void ip_tunnel_need_metadata(void);
508 void ip_tunnel_unneed_metadata(void);
509
510 #else /* CONFIG_INET */
511
lwt_tun_info(struct lwtunnel_state * lwtstate)512 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
513 {
514 return NULL;
515 }
516
ip_tunnel_need_metadata(void)517 static inline void ip_tunnel_need_metadata(void)
518 {
519 }
520
ip_tunnel_unneed_metadata(void)521 static inline void ip_tunnel_unneed_metadata(void)
522 {
523 }
524
ip_tunnel_info_opts_get(void * to,const struct ip_tunnel_info * info)525 static inline void ip_tunnel_info_opts_get(void *to,
526 const struct ip_tunnel_info *info)
527 {
528 }
529
ip_tunnel_info_opts_set(struct ip_tunnel_info * info,const void * from,int len,__be16 flags)530 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
531 const void *from, int len,
532 __be16 flags)
533 {
534 info->options_len = 0;
535 }
536
537 #endif /* CONFIG_INET */
538
539 #endif /* __NET_IP_TUNNELS_H */
540