xref: /openbmc/linux/include/net/ip_tunnels.h (revision 6f52b16c5b29b89d92c0e7236f4655dc8491ad70)
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 	/* This field used only by ERSPAN */
120 	u32		index;		/* ERSPAN type II index */
121 
122 	struct dst_cache dst_cache;
123 
124 	struct ip_tunnel_parm parms;
125 
126 	int		mlink;
127 	int		encap_hlen;	/* Encap header length (FOU,GUE) */
128 	int		hlen;		/* tun_hlen + encap_hlen */
129 	struct ip_tunnel_encap encap;
130 
131 	/* for SIT */
132 #ifdef CONFIG_IPV6_SIT_6RD
133 	struct ip_tunnel_6rd_parm ip6rd;
134 #endif
135 	struct ip_tunnel_prl_entry __rcu *prl;	/* potential router list */
136 	unsigned int		prl_count;	/* # of entries in PRL */
137 	unsigned int		ip_tnl_net_id;
138 	struct gro_cells	gro_cells;
139 	__u32			fwmark;
140 	bool			collect_md;
141 	bool			ignore_df;
142 };
143 
144 #define TUNNEL_CSUM		__cpu_to_be16(0x01)
145 #define TUNNEL_ROUTING		__cpu_to_be16(0x02)
146 #define TUNNEL_KEY		__cpu_to_be16(0x04)
147 #define TUNNEL_SEQ		__cpu_to_be16(0x08)
148 #define TUNNEL_STRICT		__cpu_to_be16(0x10)
149 #define TUNNEL_REC		__cpu_to_be16(0x20)
150 #define TUNNEL_VERSION		__cpu_to_be16(0x40)
151 #define TUNNEL_NO_KEY		__cpu_to_be16(0x80)
152 #define TUNNEL_DONT_FRAGMENT    __cpu_to_be16(0x0100)
153 #define TUNNEL_OAM		__cpu_to_be16(0x0200)
154 #define TUNNEL_CRIT_OPT		__cpu_to_be16(0x0400)
155 #define TUNNEL_GENEVE_OPT	__cpu_to_be16(0x0800)
156 #define TUNNEL_VXLAN_OPT	__cpu_to_be16(0x1000)
157 #define TUNNEL_NOCACHE		__cpu_to_be16(0x2000)
158 #define TUNNEL_ERSPAN_OPT	__cpu_to_be16(0x4000)
159 
160 #define TUNNEL_OPTIONS_PRESENT \
161 		(TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT | TUNNEL_ERSPAN_OPT)
162 
163 struct tnl_ptk_info {
164 	__be16 flags;
165 	__be16 proto;
166 	__be32 key;
167 	__be32 seq;
168 	int hdr_len;
169 };
170 
171 #define PACKET_RCVD	0
172 #define PACKET_REJECT	1
173 #define PACKET_NEXT	2
174 
175 #define IP_TNL_HASH_BITS   7
176 #define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
177 
178 struct ip_tunnel_net {
179 	struct net_device *fb_tunnel_dev;
180 	struct hlist_head tunnels[IP_TNL_HASH_SIZE];
181 	struct ip_tunnel __rcu *collect_md_tun;
182 };
183 
184 static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
185 				      __be32 saddr, __be32 daddr,
186 				      u8 tos, u8 ttl, __be32 label,
187 				      __be16 tp_src, __be16 tp_dst,
188 				      __be64 tun_id, __be16 tun_flags)
189 {
190 	key->tun_id = tun_id;
191 	key->u.ipv4.src = saddr;
192 	key->u.ipv4.dst = daddr;
193 	memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
194 	       0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
195 	key->tos = tos;
196 	key->ttl = ttl;
197 	key->label = label;
198 	key->tun_flags = tun_flags;
199 
200 	/* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
201 	 * the upper tunnel are used.
202 	 * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
203 	 */
204 	key->tp_src = tp_src;
205 	key->tp_dst = tp_dst;
206 
207 	/* Clear struct padding. */
208 	if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
209 		memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
210 		       0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
211 }
212 
213 static inline bool
214 ip_tunnel_dst_cache_usable(const struct sk_buff *skb,
215 			   const struct ip_tunnel_info *info)
216 {
217 	if (skb->mark)
218 		return false;
219 	if (!info)
220 		return true;
221 	if (info->key.tun_flags & TUNNEL_NOCACHE)
222 		return false;
223 
224 	return true;
225 }
226 
227 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
228 					       *tun_info)
229 {
230 	return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
231 }
232 
233 static inline __be64 key32_to_tunnel_id(__be32 key)
234 {
235 #ifdef __BIG_ENDIAN
236 	return (__force __be64)key;
237 #else
238 	return (__force __be64)((__force u64)key << 32);
239 #endif
240 }
241 
242 /* Returns the least-significant 32 bits of a __be64. */
243 static inline __be32 tunnel_id_to_key32(__be64 tun_id)
244 {
245 #ifdef __BIG_ENDIAN
246 	return (__force __be32)tun_id;
247 #else
248 	return (__force __be32)((__force u64)tun_id >> 32);
249 #endif
250 }
251 
252 #ifdef CONFIG_INET
253 
254 int ip_tunnel_init(struct net_device *dev);
255 void ip_tunnel_uninit(struct net_device *dev);
256 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
257 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
258 int ip_tunnel_get_iflink(const struct net_device *dev);
259 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
260 		       struct rtnl_link_ops *ops, char *devname);
261 
262 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
263 
264 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
265 		    const struct iphdr *tnl_params, const u8 protocol);
266 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
267 		       const u8 proto);
268 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
269 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
270 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
271 
272 void ip_tunnel_get_stats64(struct net_device *dev,
273 			   struct rtnl_link_stats64 *tot);
274 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
275 				   int link, __be16 flags,
276 				   __be32 remote, __be32 local,
277 				   __be32 key);
278 
279 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
280 		  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
281 		  bool log_ecn_error);
282 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
283 			 struct ip_tunnel_parm *p, __u32 fwmark);
284 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
285 		      struct ip_tunnel_parm *p, __u32 fwmark);
286 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
287 
288 struct ip_tunnel_encap_ops {
289 	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
290 	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
291 			    u8 *protocol, struct flowi4 *fl4);
292 };
293 
294 #define MAX_IPTUN_ENCAP_OPS 8
295 
296 extern const struct ip_tunnel_encap_ops __rcu *
297 		iptun_encaps[MAX_IPTUN_ENCAP_OPS];
298 
299 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
300 			    unsigned int num);
301 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
302 			    unsigned int num);
303 
304 int ip_tunnel_encap_setup(struct ip_tunnel *t,
305 			  struct ip_tunnel_encap *ipencap);
306 
307 static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
308 {
309 	const struct ip_tunnel_encap_ops *ops;
310 	int hlen = -EINVAL;
311 
312 	if (e->type == TUNNEL_ENCAP_NONE)
313 		return 0;
314 
315 	if (e->type >= MAX_IPTUN_ENCAP_OPS)
316 		return -EINVAL;
317 
318 	rcu_read_lock();
319 	ops = rcu_dereference(iptun_encaps[e->type]);
320 	if (likely(ops && ops->encap_hlen))
321 		hlen = ops->encap_hlen(e);
322 	rcu_read_unlock();
323 
324 	return hlen;
325 }
326 
327 static inline int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
328 				  u8 *protocol, struct flowi4 *fl4)
329 {
330 	const struct ip_tunnel_encap_ops *ops;
331 	int ret = -EINVAL;
332 
333 	if (t->encap.type == TUNNEL_ENCAP_NONE)
334 		return 0;
335 
336 	if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
337 		return -EINVAL;
338 
339 	rcu_read_lock();
340 	ops = rcu_dereference(iptun_encaps[t->encap.type]);
341 	if (likely(ops && ops->build_header))
342 		ret = ops->build_header(skb, &t->encap, protocol, fl4);
343 	rcu_read_unlock();
344 
345 	return ret;
346 }
347 
348 /* Extract dsfield from inner protocol */
349 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
350 				       const struct sk_buff *skb)
351 {
352 	if (skb->protocol == htons(ETH_P_IP))
353 		return iph->tos;
354 	else if (skb->protocol == htons(ETH_P_IPV6))
355 		return ipv6_get_dsfield((const struct ipv6hdr *)iph);
356 	else
357 		return 0;
358 }
359 
360 /* Propogate ECN bits out */
361 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
362 				     const struct sk_buff *skb)
363 {
364 	u8 inner = ip_tunnel_get_dsfield(iph, skb);
365 
366 	return INET_ECN_encapsulate(tos, inner);
367 }
368 
369 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
370 			   __be16 inner_proto, bool raw_proto, bool xnet);
371 
372 static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
373 				       __be16 inner_proto, bool xnet)
374 {
375 	return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
376 }
377 
378 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
379 		   __be32 src, __be32 dst, u8 proto,
380 		   u8 tos, u8 ttl, __be16 df, bool xnet);
381 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
382 					     gfp_t flags);
383 
384 int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
385 
386 static inline int iptunnel_pull_offloads(struct sk_buff *skb)
387 {
388 	if (skb_is_gso(skb)) {
389 		int err;
390 
391 		err = skb_unclone(skb, GFP_ATOMIC);
392 		if (unlikely(err))
393 			return err;
394 		skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
395 					       NETIF_F_GSO_SHIFT);
396 	}
397 
398 	skb->encapsulation = 0;
399 	return 0;
400 }
401 
402 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
403 {
404 	if (pkt_len > 0) {
405 		struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
406 
407 		u64_stats_update_begin(&tstats->syncp);
408 		tstats->tx_bytes += pkt_len;
409 		tstats->tx_packets++;
410 		u64_stats_update_end(&tstats->syncp);
411 		put_cpu_ptr(tstats);
412 	} else {
413 		struct net_device_stats *err_stats = &dev->stats;
414 
415 		if (pkt_len < 0) {
416 			err_stats->tx_errors++;
417 			err_stats->tx_aborted_errors++;
418 		} else {
419 			err_stats->tx_dropped++;
420 		}
421 	}
422 }
423 
424 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
425 {
426 	return info + 1;
427 }
428 
429 static inline void ip_tunnel_info_opts_get(void *to,
430 					   const struct ip_tunnel_info *info)
431 {
432 	memcpy(to, info + 1, info->options_len);
433 }
434 
435 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
436 					   const void *from, int len)
437 {
438 	memcpy(ip_tunnel_info_opts(info), from, len);
439 	info->options_len = len;
440 }
441 
442 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
443 {
444 	return (struct ip_tunnel_info *)lwtstate->data;
445 }
446 
447 extern struct static_key ip_tunnel_metadata_cnt;
448 
449 /* Returns > 0 if metadata should be collected */
450 static inline int ip_tunnel_collect_metadata(void)
451 {
452 	return static_key_false(&ip_tunnel_metadata_cnt);
453 }
454 
455 void __init ip_tunnel_core_init(void);
456 
457 void ip_tunnel_need_metadata(void);
458 void ip_tunnel_unneed_metadata(void);
459 
460 #else /* CONFIG_INET */
461 
462 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
463 {
464 	return NULL;
465 }
466 
467 static inline void ip_tunnel_need_metadata(void)
468 {
469 }
470 
471 static inline void ip_tunnel_unneed_metadata(void)
472 {
473 }
474 
475 static inline void ip_tunnel_info_opts_get(void *to,
476 					   const struct ip_tunnel_info *info)
477 {
478 }
479 
480 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
481 					   const void *from, int len)
482 {
483 	info->options_len = 0;
484 }
485 
486 #endif /* CONFIG_INET */
487 
488 #endif /* __NET_IP_TUNNELS_H */
489