xref: /linux-6.15/include/net/ip_tunnels.h (revision 6b8abef5)
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 <net/dsfield.h>
11 #include <net/gro_cells.h>
12 #include <net/inet_ecn.h>
13 #include <net/netns/generic.h>
14 #include <net/rtnetlink.h>
15 #include <net/lwtunnel.h>
16 #include <net/dst_cache.h>
17 
18 #if IS_ENABLED(CONFIG_IPV6)
19 #include <net/ipv6.h>
20 #include <net/ip6_fib.h>
21 #include <net/ip6_route.h>
22 #endif
23 
24 /* Keep error state on tunnel for 30 sec */
25 #define IPTUNNEL_ERR_TIMEO	(30*HZ)
26 
27 /* Used to memset ip_tunnel padding. */
28 #define IP_TUNNEL_KEY_SIZE	offsetofend(struct ip_tunnel_key, tp_dst)
29 
30 /* Used to memset ipv4 address padding. */
31 #define IP_TUNNEL_KEY_IPV4_PAD	offsetofend(struct ip_tunnel_key, u.ipv4.dst)
32 #define IP_TUNNEL_KEY_IPV4_PAD_LEN				\
33 	(FIELD_SIZEOF(struct ip_tunnel_key, u) -		\
34 	 FIELD_SIZEOF(struct ip_tunnel_key, u.ipv4))
35 
36 struct ip_tunnel_key {
37 	__be64			tun_id;
38 	union {
39 		struct {
40 			__be32	src;
41 			__be32	dst;
42 		} ipv4;
43 		struct {
44 			struct in6_addr src;
45 			struct in6_addr dst;
46 		} ipv6;
47 	} u;
48 	__be16			tun_flags;
49 	u8			tos;		/* TOS for IPv4, TC for IPv6 */
50 	u8			ttl;		/* TTL for IPv4, HL for IPv6 */
51 	__be32			label;		/* Flow Label for IPv6 */
52 	__be16			tp_src;
53 	__be16			tp_dst;
54 };
55 
56 /* Flags for ip_tunnel_info mode. */
57 #define IP_TUNNEL_INFO_TX	0x01	/* represents tx tunnel parameters */
58 #define IP_TUNNEL_INFO_IPV6	0x02	/* key contains IPv6 addresses */
59 
60 struct ip_tunnel_info {
61 	struct ip_tunnel_key	key;
62 #ifdef CONFIG_DST_CACHE
63 	struct dst_cache	dst_cache;
64 #endif
65 	u8			options_len;
66 	u8			mode;
67 };
68 
69 /* 6rd prefix/relay information */
70 #ifdef CONFIG_IPV6_SIT_6RD
71 struct ip_tunnel_6rd_parm {
72 	struct in6_addr		prefix;
73 	__be32			relay_prefix;
74 	u16			prefixlen;
75 	u16			relay_prefixlen;
76 };
77 #endif
78 
79 struct ip_tunnel_encap {
80 	u16			type;
81 	u16			flags;
82 	__be16			sport;
83 	__be16			dport;
84 };
85 
86 struct ip_tunnel_prl_entry {
87 	struct ip_tunnel_prl_entry __rcu *next;
88 	__be32				addr;
89 	u16				flags;
90 	struct rcu_head			rcu_head;
91 };
92 
93 struct metadata_dst;
94 
95 struct ip_tunnel {
96 	struct ip_tunnel __rcu	*next;
97 	struct hlist_node hash_node;
98 	struct net_device	*dev;
99 	struct net		*net;	/* netns for packet i/o */
100 
101 	int		err_count;	/* Number of arrived ICMP errors */
102 	unsigned long	err_time;	/* Time when the last ICMP error
103 					 * arrived */
104 
105 	/* These four fields used only by GRE */
106 	u32		i_seqno;	/* The last seen seqno	*/
107 	u32		o_seqno;	/* The last output seqno */
108 	int		tun_hlen;	/* Precalculated header length */
109 	int		mlink;
110 
111 	struct dst_cache dst_cache;
112 
113 	struct ip_tunnel_parm parms;
114 
115 	int		encap_hlen;	/* Encap header length (FOU,GUE) */
116 	struct ip_tunnel_encap encap;
117 
118 	int		hlen;		/* tun_hlen + encap_hlen */
119 
120 	/* for SIT */
121 #ifdef CONFIG_IPV6_SIT_6RD
122 	struct ip_tunnel_6rd_parm ip6rd;
123 #endif
124 	struct ip_tunnel_prl_entry __rcu *prl;	/* potential router list */
125 	unsigned int		prl_count;	/* # of entries in PRL */
126 	int			ip_tnl_net_id;
127 	struct gro_cells	gro_cells;
128 	bool			collect_md;
129 };
130 
131 #define TUNNEL_CSUM		__cpu_to_be16(0x01)
132 #define TUNNEL_ROUTING		__cpu_to_be16(0x02)
133 #define TUNNEL_KEY		__cpu_to_be16(0x04)
134 #define TUNNEL_SEQ		__cpu_to_be16(0x08)
135 #define TUNNEL_STRICT		__cpu_to_be16(0x10)
136 #define TUNNEL_REC		__cpu_to_be16(0x20)
137 #define TUNNEL_VERSION		__cpu_to_be16(0x40)
138 #define TUNNEL_NO_KEY		__cpu_to_be16(0x80)
139 #define TUNNEL_DONT_FRAGMENT    __cpu_to_be16(0x0100)
140 #define TUNNEL_OAM		__cpu_to_be16(0x0200)
141 #define TUNNEL_CRIT_OPT		__cpu_to_be16(0x0400)
142 #define TUNNEL_GENEVE_OPT	__cpu_to_be16(0x0800)
143 #define TUNNEL_VXLAN_OPT	__cpu_to_be16(0x1000)
144 #define TUNNEL_NOCACHE		__cpu_to_be16(0x2000)
145 
146 #define TUNNEL_OPTIONS_PRESENT	(TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT)
147 
148 struct tnl_ptk_info {
149 	__be16 flags;
150 	__be16 proto;
151 	__be32 key;
152 	__be32 seq;
153 };
154 
155 #define PACKET_RCVD	0
156 #define PACKET_REJECT	1
157 
158 #define IP_TNL_HASH_BITS   7
159 #define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
160 
161 struct ip_tunnel_net {
162 	struct net_device *fb_tunnel_dev;
163 	struct hlist_head tunnels[IP_TNL_HASH_SIZE];
164 	struct ip_tunnel __rcu *collect_md_tun;
165 };
166 
167 struct ip_tunnel_encap_ops {
168 	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
169 	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
170 			    u8 *protocol, struct flowi4 *fl4);
171 };
172 
173 #define MAX_IPTUN_ENCAP_OPS 8
174 
175 extern const struct ip_tunnel_encap_ops __rcu *
176 		iptun_encaps[MAX_IPTUN_ENCAP_OPS];
177 
178 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
179 			    unsigned int num);
180 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
181 			    unsigned int num);
182 
183 static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
184 				      __be32 saddr, __be32 daddr,
185 				      u8 tos, u8 ttl, __be32 label,
186 				      __be16 tp_src, __be16 tp_dst,
187 				      __be64 tun_id, __be16 tun_flags)
188 {
189 	key->tun_id = tun_id;
190 	key->u.ipv4.src = saddr;
191 	key->u.ipv4.dst = daddr;
192 	memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
193 	       0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
194 	key->tos = tos;
195 	key->ttl = ttl;
196 	key->label = label;
197 	key->tun_flags = tun_flags;
198 
199 	/* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
200 	 * the upper tunnel are used.
201 	 * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
202 	 */
203 	key->tp_src = tp_src;
204 	key->tp_dst = tp_dst;
205 
206 	/* Clear struct padding. */
207 	if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
208 		memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
209 		       0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
210 }
211 
212 static inline bool
213 ip_tunnel_dst_cache_usable(const struct sk_buff *skb,
214 			   const struct ip_tunnel_info *info)
215 {
216 	if (skb->mark)
217 		return false;
218 	if (!info)
219 		return true;
220 	if (info->key.tun_flags & TUNNEL_NOCACHE)
221 		return false;
222 
223 	return true;
224 }
225 
226 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
227 					       *tun_info)
228 {
229 	return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
230 }
231 
232 #ifdef CONFIG_INET
233 
234 int ip_tunnel_init(struct net_device *dev);
235 void ip_tunnel_uninit(struct net_device *dev);
236 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
237 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
238 int ip_tunnel_get_iflink(const struct net_device *dev);
239 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
240 		       struct rtnl_link_ops *ops, char *devname);
241 
242 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
243 
244 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
245 		    const struct iphdr *tnl_params, const u8 protocol);
246 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
247 int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
248 		    u8 *protocol, struct flowi4 *fl4);
249 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
250 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
251 
252 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
253 						struct rtnl_link_stats64 *tot);
254 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
255 				   int link, __be16 flags,
256 				   __be32 remote, __be32 local,
257 				   __be32 key);
258 
259 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
260 		  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
261 		  bool log_ecn_error);
262 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
263 			 struct ip_tunnel_parm *p);
264 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
265 		      struct ip_tunnel_parm *p);
266 void ip_tunnel_setup(struct net_device *dev, int net_id);
267 int ip_tunnel_encap_setup(struct ip_tunnel *t,
268 			  struct ip_tunnel_encap *ipencap);
269 
270 /* Extract dsfield from inner protocol */
271 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
272 				       const struct sk_buff *skb)
273 {
274 	if (skb->protocol == htons(ETH_P_IP))
275 		return iph->tos;
276 	else if (skb->protocol == htons(ETH_P_IPV6))
277 		return ipv6_get_dsfield((const struct ipv6hdr *)iph);
278 	else
279 		return 0;
280 }
281 
282 /* Propogate ECN bits out */
283 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
284 				     const struct sk_buff *skb)
285 {
286 	u8 inner = ip_tunnel_get_dsfield(iph, skb);
287 
288 	return INET_ECN_encapsulate(tos, inner);
289 }
290 
291 int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto,
292 			 bool xnet);
293 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
294 		   __be32 src, __be32 dst, u8 proto,
295 		   u8 tos, u8 ttl, __be16 df, bool xnet);
296 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
297 					     gfp_t flags);
298 
299 struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
300 
301 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
302 {
303 	if (pkt_len > 0) {
304 		struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
305 
306 		u64_stats_update_begin(&tstats->syncp);
307 		tstats->tx_bytes += pkt_len;
308 		tstats->tx_packets++;
309 		u64_stats_update_end(&tstats->syncp);
310 		put_cpu_ptr(tstats);
311 	} else {
312 		struct net_device_stats *err_stats = &dev->stats;
313 
314 		if (pkt_len < 0) {
315 			err_stats->tx_errors++;
316 			err_stats->tx_aborted_errors++;
317 		} else {
318 			err_stats->tx_dropped++;
319 		}
320 	}
321 }
322 
323 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
324 {
325 	return info + 1;
326 }
327 
328 static inline void ip_tunnel_info_opts_get(void *to,
329 					   const struct ip_tunnel_info *info)
330 {
331 	memcpy(to, info + 1, info->options_len);
332 }
333 
334 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
335 					   const void *from, int len)
336 {
337 	memcpy(ip_tunnel_info_opts(info), from, len);
338 	info->options_len = len;
339 }
340 
341 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
342 {
343 	return (struct ip_tunnel_info *)lwtstate->data;
344 }
345 
346 extern struct static_key ip_tunnel_metadata_cnt;
347 
348 /* Returns > 0 if metadata should be collected */
349 static inline int ip_tunnel_collect_metadata(void)
350 {
351 	return static_key_false(&ip_tunnel_metadata_cnt);
352 }
353 
354 void __init ip_tunnel_core_init(void);
355 
356 void ip_tunnel_need_metadata(void);
357 void ip_tunnel_unneed_metadata(void);
358 
359 #else /* CONFIG_INET */
360 
361 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
362 {
363 	return NULL;
364 }
365 
366 static inline void ip_tunnel_need_metadata(void)
367 {
368 }
369 
370 static inline void ip_tunnel_unneed_metadata(void)
371 {
372 }
373 
374 static inline void ip_tunnel_info_opts_get(void *to,
375 					   const struct ip_tunnel_info *info)
376 {
377 }
378 
379 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
380 					   const void *from, int len)
381 {
382 	info->options_len = 0;
383 }
384 
385 #endif /* CONFIG_INET */
386 
387 #endif /* __NET_IP_TUNNELS_H */
388