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  1#ifndef __NET_IP_TUNNELS_H
  2#define __NET_IP_TUNNELS_H 1
  3
  4#include <linux/if_tunnel.h>
  5#include <linux/netdevice.h>
  6#include <linux/skbuff.h>
  7#include <linux/socket.h>
  8#include <linux/types.h>
  9#include <linux/u64_stats_sync.h>
 10#include <linux/bitops.h>
 11
 12#include <net/dsfield.h>
 13#include <net/gro_cells.h>
 14#include <net/inet_ecn.h>
 15#include <net/netns/generic.h>
 16#include <net/rtnetlink.h>
 17#include <net/lwtunnel.h>
 18#include <net/dst_cache.h>
 19
 20#if IS_ENABLED(CONFIG_IPV6)
 21#include <net/ipv6.h>
 22#include <net/ip6_fib.h>
 23#include <net/ip6_route.h>
 24#endif
 25
 26/* Keep error state on tunnel for 30 sec */
 27#define IPTUNNEL_ERR_TIMEO	(30*HZ)
 28
 29/* Used to memset ip_tunnel padding. */
 30#define IP_TUNNEL_KEY_SIZE	offsetofend(struct ip_tunnel_key, tp_dst)
 31
 32/* Used to memset ipv4 address padding. */
 33#define IP_TUNNEL_KEY_IPV4_PAD	offsetofend(struct ip_tunnel_key, u.ipv4.dst)
 34#define IP_TUNNEL_KEY_IPV4_PAD_LEN				\
 35	(FIELD_SIZEOF(struct ip_tunnel_key, u) -		\
 36	 FIELD_SIZEOF(struct ip_tunnel_key, u.ipv4))
 37
 38struct ip_tunnel_key {
 39	__be64			tun_id;
 40	union {
 41		struct {
 42			__be32	src;
 43			__be32	dst;
 44		} ipv4;
 45		struct {
 46			struct in6_addr src;
 47			struct in6_addr dst;
 48		} ipv6;
 49	} u;
 50	__be16			tun_flags;
 51	u8			tos;		/* TOS for IPv4, TC for IPv6 */
 52	u8			ttl;		/* TTL for IPv4, HL for IPv6 */
 53	__be32			label;		/* Flow Label for IPv6 */
 54	__be16			tp_src;
 55	__be16			tp_dst;
 56};
 57
 58/* Flags for ip_tunnel_info mode. */
 59#define IP_TUNNEL_INFO_TX	0x01	/* represents tx tunnel parameters */
 60#define IP_TUNNEL_INFO_IPV6	0x02	/* key contains IPv6 addresses */
 61
 62/* Maximum tunnel options length. */
 63#define IP_TUNNEL_OPTS_MAX					\
 64	GENMASK((FIELD_SIZEOF(struct ip_tunnel_info,		\
 65			      options_len) * BITS_PER_BYTE) - 1, 0)
 66
 67struct ip_tunnel_info {
 68	struct ip_tunnel_key	key;
 69#ifdef CONFIG_DST_CACHE
 70	struct dst_cache	dst_cache;
 71#endif
 72	u8			options_len;
 73	u8			mode;
 74};
 75
 76/* 6rd prefix/relay information */
 77#ifdef CONFIG_IPV6_SIT_6RD
 78struct ip_tunnel_6rd_parm {
 79	struct in6_addr		prefix;
 80	__be32			relay_prefix;
 81	u16			prefixlen;
 82	u16			relay_prefixlen;
 83};
 84#endif
 85
 86struct ip_tunnel_encap {
 87	u16			type;
 88	u16			flags;
 89	__be16			sport;
 90	__be16			dport;
 91};
 92
 93struct ip_tunnel_prl_entry {
 94	struct ip_tunnel_prl_entry __rcu *next;
 95	__be32				addr;
 96	u16				flags;
 97	struct rcu_head			rcu_head;
 98};
 99
100struct metadata_dst;
101
102struct ip_tunnel {
103	struct ip_tunnel __rcu	*next;
104	struct hlist_node hash_node;
105	struct net_device	*dev;
106	struct net		*net;	/* netns for packet i/o */
107
108	unsigned long	err_time;	/* Time when the last ICMP error
109					 * arrived */
110	int		err_count;	/* Number of arrived ICMP errors */
111
112	/* These four fields used only by GRE */
113	u32		i_seqno;	/* The last seen seqno	*/
114	u32		o_seqno;	/* The last output seqno */
115	int		tun_hlen;	/* Precalculated header length */
116
117	struct dst_cache dst_cache;
118
119	struct ip_tunnel_parm parms;
120
121	int		mlink;
122	int		encap_hlen;	/* Encap header length (FOU,GUE) */
123	int		hlen;		/* tun_hlen + encap_hlen */
124	struct ip_tunnel_encap encap;
125
126	/* for SIT */
127#ifdef CONFIG_IPV6_SIT_6RD
128	struct ip_tunnel_6rd_parm ip6rd;
129#endif
130	struct ip_tunnel_prl_entry __rcu *prl;	/* potential router list */
131	unsigned int		prl_count;	/* # of entries in PRL */
132	unsigned int		ip_tnl_net_id;
133	struct gro_cells	gro_cells;
134	bool			collect_md;
135	bool			ignore_df;
136};
137
138#define TUNNEL_CSUM		__cpu_to_be16(0x01)
139#define TUNNEL_ROUTING		__cpu_to_be16(0x02)
140#define TUNNEL_KEY		__cpu_to_be16(0x04)
141#define TUNNEL_SEQ		__cpu_to_be16(0x08)
142#define TUNNEL_STRICT		__cpu_to_be16(0x10)
143#define TUNNEL_REC		__cpu_to_be16(0x20)
144#define TUNNEL_VERSION		__cpu_to_be16(0x40)
145#define TUNNEL_NO_KEY		__cpu_to_be16(0x80)
146#define TUNNEL_DONT_FRAGMENT    __cpu_to_be16(0x0100)
147#define TUNNEL_OAM		__cpu_to_be16(0x0200)
148#define TUNNEL_CRIT_OPT		__cpu_to_be16(0x0400)
149#define TUNNEL_GENEVE_OPT	__cpu_to_be16(0x0800)
150#define TUNNEL_VXLAN_OPT	__cpu_to_be16(0x1000)
151#define TUNNEL_NOCACHE		__cpu_to_be16(0x2000)
152
153#define TUNNEL_OPTIONS_PRESENT	(TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT)
154
155struct tnl_ptk_info {
156	__be16 flags;
157	__be16 proto;
158	__be32 key;
159	__be32 seq;
160	int hdr_len;
161};
162
163#define PACKET_RCVD	0
164#define PACKET_REJECT	1
165#define PACKET_NEXT	2
166
167#define IP_TNL_HASH_BITS   7
168#define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
169
170struct ip_tunnel_net {
171	struct net_device *fb_tunnel_dev;
172	struct hlist_head tunnels[IP_TNL_HASH_SIZE];
173	struct ip_tunnel __rcu *collect_md_tun;
174};
175
176static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
177				      __be32 saddr, __be32 daddr,
178				      u8 tos, u8 ttl, __be32 label,
179				      __be16 tp_src, __be16 tp_dst,
180				      __be64 tun_id, __be16 tun_flags)
181{
182	key->tun_id = tun_id;
183	key->u.ipv4.src = saddr;
184	key->u.ipv4.dst = daddr;
185	memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
186	       0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
187	key->tos = tos;
188	key->ttl = ttl;
189	key->label = label;
190	key->tun_flags = tun_flags;
191
192	/* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
193	 * the upper tunnel are used.
194	 * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
195	 */
196	key->tp_src = tp_src;
197	key->tp_dst = tp_dst;
198
199	/* Clear struct padding. */
200	if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
201		memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
202		       0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
203}
204
205static inline bool
206ip_tunnel_dst_cache_usable(const struct sk_buff *skb,
207			   const struct ip_tunnel_info *info)
208{
209	if (skb->mark)
210		return false;
211	if (!info)
212		return true;
213	if (info->key.tun_flags & TUNNEL_NOCACHE)
214		return false;
215
216	return true;
217}
218
219static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
220					       *tun_info)
221{
222	return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
223}
224
225static inline __be64 key32_to_tunnel_id(__be32 key)
226{
227#ifdef __BIG_ENDIAN
228	return (__force __be64)key;
229#else
230	return (__force __be64)((__force u64)key << 32);
231#endif
232}
233
234/* Returns the least-significant 32 bits of a __be64. */
235static inline __be32 tunnel_id_to_key32(__be64 tun_id)
236{
237#ifdef __BIG_ENDIAN
238	return (__force __be32)tun_id;
239#else
240	return (__force __be32)((__force u64)tun_id >> 32);
241#endif
242}
243
244#ifdef CONFIG_INET
245
246int ip_tunnel_init(struct net_device *dev);
247void ip_tunnel_uninit(struct net_device *dev);
248void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
249struct net *ip_tunnel_get_link_net(const struct net_device *dev);
250int ip_tunnel_get_iflink(const struct net_device *dev);
251int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
252		       struct rtnl_link_ops *ops, char *devname);
253
254void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
255
256void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
257		    const struct iphdr *tnl_params, const u8 protocol);
258void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
259		       const u8 proto);
260int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
261int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
262int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
263
264struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
265						struct rtnl_link_stats64 *tot);
266struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
267				   int link, __be16 flags,
268				   __be32 remote, __be32 local,
269				   __be32 key);
270
271int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
272		  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
273		  bool log_ecn_error);
274int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
275			 struct ip_tunnel_parm *p);
276int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
277		      struct ip_tunnel_parm *p);
278void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
279
280struct ip_tunnel_encap_ops {
281	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
282	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
283			    u8 *protocol, struct flowi4 *fl4);
284};
285
286#define MAX_IPTUN_ENCAP_OPS 8
287
288extern const struct ip_tunnel_encap_ops __rcu *
289		iptun_encaps[MAX_IPTUN_ENCAP_OPS];
290
291int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
292			    unsigned int num);
293int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
294			    unsigned int num);
295
296int ip_tunnel_encap_setup(struct ip_tunnel *t,
297			  struct ip_tunnel_encap *ipencap);
298
299static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
300{
301	const struct ip_tunnel_encap_ops *ops;
302	int hlen = -EINVAL;
303
304	if (e->type == TUNNEL_ENCAP_NONE)
305		return 0;
306
307	if (e->type >= MAX_IPTUN_ENCAP_OPS)
308		return -EINVAL;
309
310	rcu_read_lock();
311	ops = rcu_dereference(iptun_encaps[e->type]);
312	if (likely(ops && ops->encap_hlen))
313		hlen = ops->encap_hlen(e);
314	rcu_read_unlock();
315
316	return hlen;
317}
318
319static inline int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
320				  u8 *protocol, struct flowi4 *fl4)
321{
322	const struct ip_tunnel_encap_ops *ops;
323	int ret = -EINVAL;
324
325	if (t->encap.type == TUNNEL_ENCAP_NONE)
326		return 0;
327
328	if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
329		return -EINVAL;
330
331	rcu_read_lock();
332	ops = rcu_dereference(iptun_encaps[t->encap.type]);
333	if (likely(ops && ops->build_header))
334		ret = ops->build_header(skb, &t->encap, protocol, fl4);
335	rcu_read_unlock();
336
337	return ret;
338}
339
340/* Extract dsfield from inner protocol */
341static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
342				       const struct sk_buff *skb)
343{
344	if (skb->protocol == htons(ETH_P_IP))
345		return iph->tos;
346	else if (skb->protocol == htons(ETH_P_IPV6))
347		return ipv6_get_dsfield((const struct ipv6hdr *)iph);
348	else
349		return 0;
350}
351
352/* Propogate ECN bits out */
353static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
354				     const struct sk_buff *skb)
355{
356	u8 inner = ip_tunnel_get_dsfield(iph, skb);
357
358	return INET_ECN_encapsulate(tos, inner);
359}
360
361int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
362			   __be16 inner_proto, bool raw_proto, bool xnet);
363
364static inline int iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
365				       __be16 inner_proto, bool xnet)
366{
367	return __iptunnel_pull_header(skb, hdr_len, inner_proto, false, xnet);
368}
369
370void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
371		   __be32 src, __be32 dst, u8 proto,
372		   u8 tos, u8 ttl, __be16 df, bool xnet);
373struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
374					     gfp_t flags);
375
376int iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
377
378static inline int iptunnel_pull_offloads(struct sk_buff *skb)
379{
380	if (skb_is_gso(skb)) {
381		int err;
382
383		err = skb_unclone(skb, GFP_ATOMIC);
384		if (unlikely(err))
385			return err;
386		skb_shinfo(skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >>
387					       NETIF_F_GSO_SHIFT);
388	}
389
390	skb->encapsulation = 0;
391	return 0;
392}
393
394static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
395{
396	if (pkt_len > 0) {
397		struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
398
399		u64_stats_update_begin(&tstats->syncp);
400		tstats->tx_bytes += pkt_len;
401		tstats->tx_packets++;
402		u64_stats_update_end(&tstats->syncp);
403		put_cpu_ptr(tstats);
404	} else {
405		struct net_device_stats *err_stats = &dev->stats;
406
407		if (pkt_len < 0) {
408			err_stats->tx_errors++;
409			err_stats->tx_aborted_errors++;
410		} else {
411			err_stats->tx_dropped++;
412		}
413	}
414}
415
416static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
417{
418	return info + 1;
419}
420
421static inline void ip_tunnel_info_opts_get(void *to,
422					   const struct ip_tunnel_info *info)
423{
424	memcpy(to, info + 1, info->options_len);
425}
426
427static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
428					   const void *from, int len)
429{
430	memcpy(ip_tunnel_info_opts(info), from, len);
431	info->options_len = len;
432}
433
434static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
435{
436	return (struct ip_tunnel_info *)lwtstate->data;
437}
438
439extern struct static_key ip_tunnel_metadata_cnt;
440
441/* Returns > 0 if metadata should be collected */
442static inline int ip_tunnel_collect_metadata(void)
443{
444	return static_key_false(&ip_tunnel_metadata_cnt);
445}
446
447void __init ip_tunnel_core_init(void);
448
449void ip_tunnel_need_metadata(void);
450void ip_tunnel_unneed_metadata(void);
451
452#else /* CONFIG_INET */
453
454static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
455{
456	return NULL;
457}
458
459static inline void ip_tunnel_need_metadata(void)
460{
461}
462
463static inline void ip_tunnel_unneed_metadata(void)
464{
465}
466
467static inline void ip_tunnel_info_opts_get(void *to,
468					   const struct ip_tunnel_info *info)
469{
470}
471
472static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
473					   const void *from, int len)
474{
475	info->options_len = 0;
476}
477
478#endif /* CONFIG_INET */
479
480#endif /* __NET_IP_TUNNELS_H */