xref: /linux/include/net/ip_tunnels.h (revision 3f2fb9a834cb1fcddbae22deca7fde136944dc89)
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 	__be16			tp_src;
52 	__be16			tp_dst;
53 };
54 
55 /* Flags for ip_tunnel_info mode. */
56 #define IP_TUNNEL_INFO_TX	0x01	/* represents tx tunnel parameters */
57 #define IP_TUNNEL_INFO_IPV6	0x02	/* key contains IPv6 addresses */
58 
59 struct ip_tunnel_info {
60 	struct ip_tunnel_key	key;
61 #ifdef CONFIG_DST_CACHE
62 	struct dst_cache	dst_cache;
63 #endif
64 	u8			options_len;
65 	u8			mode;
66 };
67 
68 /* 6rd prefix/relay information */
69 #ifdef CONFIG_IPV6_SIT_6RD
70 struct ip_tunnel_6rd_parm {
71 	struct in6_addr		prefix;
72 	__be32			relay_prefix;
73 	u16			prefixlen;
74 	u16			relay_prefixlen;
75 };
76 #endif
77 
78 struct ip_tunnel_encap {
79 	u16			type;
80 	u16			flags;
81 	__be16			sport;
82 	__be16			dport;
83 };
84 
85 struct ip_tunnel_prl_entry {
86 	struct ip_tunnel_prl_entry __rcu *next;
87 	__be32				addr;
88 	u16				flags;
89 	struct rcu_head			rcu_head;
90 };
91 
92 struct metadata_dst;
93 
94 struct ip_tunnel {
95 	struct ip_tunnel __rcu	*next;
96 	struct hlist_node hash_node;
97 	struct net_device	*dev;
98 	struct net		*net;	/* netns for packet i/o */
99 
100 	int		err_count;	/* Number of arrived ICMP errors */
101 	unsigned long	err_time;	/* Time when the last ICMP error
102 					 * arrived */
103 
104 	/* These four fields used only by GRE */
105 	u32		i_seqno;	/* The last seen seqno	*/
106 	u32		o_seqno;	/* The last output seqno */
107 	int		tun_hlen;	/* Precalculated header length */
108 	int		mlink;
109 
110 	struct dst_cache dst_cache;
111 
112 	struct ip_tunnel_parm parms;
113 
114 	int		encap_hlen;	/* Encap header length (FOU,GUE) */
115 	struct ip_tunnel_encap encap;
116 
117 	int		hlen;		/* tun_hlen + encap_hlen */
118 
119 	/* for SIT */
120 #ifdef CONFIG_IPV6_SIT_6RD
121 	struct ip_tunnel_6rd_parm ip6rd;
122 #endif
123 	struct ip_tunnel_prl_entry __rcu *prl;	/* potential router list */
124 	unsigned int		prl_count;	/* # of entries in PRL */
125 	int			ip_tnl_net_id;
126 	struct gro_cells	gro_cells;
127 	bool			collect_md;
128 };
129 
130 #define TUNNEL_CSUM		__cpu_to_be16(0x01)
131 #define TUNNEL_ROUTING		__cpu_to_be16(0x02)
132 #define TUNNEL_KEY		__cpu_to_be16(0x04)
133 #define TUNNEL_SEQ		__cpu_to_be16(0x08)
134 #define TUNNEL_STRICT		__cpu_to_be16(0x10)
135 #define TUNNEL_REC		__cpu_to_be16(0x20)
136 #define TUNNEL_VERSION		__cpu_to_be16(0x40)
137 #define TUNNEL_NO_KEY		__cpu_to_be16(0x80)
138 #define TUNNEL_DONT_FRAGMENT    __cpu_to_be16(0x0100)
139 #define TUNNEL_OAM		__cpu_to_be16(0x0200)
140 #define TUNNEL_CRIT_OPT		__cpu_to_be16(0x0400)
141 #define TUNNEL_GENEVE_OPT	__cpu_to_be16(0x0800)
142 #define TUNNEL_VXLAN_OPT	__cpu_to_be16(0x1000)
143 
144 #define TUNNEL_OPTIONS_PRESENT	(TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT)
145 
146 struct tnl_ptk_info {
147 	__be16 flags;
148 	__be16 proto;
149 	__be32 key;
150 	__be32 seq;
151 };
152 
153 #define PACKET_RCVD	0
154 #define PACKET_REJECT	1
155 
156 #define IP_TNL_HASH_BITS   7
157 #define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
158 
159 struct ip_tunnel_net {
160 	struct net_device *fb_tunnel_dev;
161 	struct hlist_head tunnels[IP_TNL_HASH_SIZE];
162 	struct ip_tunnel __rcu *collect_md_tun;
163 };
164 
165 struct ip_tunnel_encap_ops {
166 	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
167 	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
168 			    u8 *protocol, struct flowi4 *fl4);
169 };
170 
171 #define MAX_IPTUN_ENCAP_OPS 8
172 
173 extern const struct ip_tunnel_encap_ops __rcu *
174 		iptun_encaps[MAX_IPTUN_ENCAP_OPS];
175 
176 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
177 			    unsigned int num);
178 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
179 			    unsigned int num);
180 
181 static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
182 				      __be32 saddr, __be32 daddr,
183 				      u8 tos, u8 ttl,
184 				      __be16 tp_src, __be16 tp_dst,
185 				      __be64 tun_id, __be16 tun_flags)
186 {
187 	key->tun_id = tun_id;
188 	key->u.ipv4.src = saddr;
189 	key->u.ipv4.dst = daddr;
190 	memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
191 	       0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
192 	key->tos = tos;
193 	key->ttl = ttl;
194 	key->tun_flags = tun_flags;
195 
196 	/* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
197 	 * the upper tunnel are used.
198 	 * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
199 	 */
200 	key->tp_src = tp_src;
201 	key->tp_dst = tp_dst;
202 
203 	/* Clear struct padding. */
204 	if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
205 		memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
206 		       0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
207 }
208 
209 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
210 					       *tun_info)
211 {
212 	return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
213 }
214 
215 #ifdef CONFIG_INET
216 
217 int ip_tunnel_init(struct net_device *dev);
218 void ip_tunnel_uninit(struct net_device *dev);
219 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
220 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
221 int ip_tunnel_get_iflink(const struct net_device *dev);
222 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
223 		       struct rtnl_link_ops *ops, char *devname);
224 
225 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
226 
227 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
228 		    const struct iphdr *tnl_params, const u8 protocol);
229 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
230 int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
231 		    u8 *protocol, struct flowi4 *fl4);
232 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict);
233 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
234 
235 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
236 						struct rtnl_link_stats64 *tot);
237 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
238 				   int link, __be16 flags,
239 				   __be32 remote, __be32 local,
240 				   __be32 key);
241 
242 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
243 		  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
244 		  bool log_ecn_error);
245 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
246 			 struct ip_tunnel_parm *p);
247 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
248 		      struct ip_tunnel_parm *p);
249 void ip_tunnel_setup(struct net_device *dev, int net_id);
250 int ip_tunnel_encap_setup(struct ip_tunnel *t,
251 			  struct ip_tunnel_encap *ipencap);
252 
253 /* Extract dsfield from inner protocol */
254 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
255 				       const struct sk_buff *skb)
256 {
257 	if (skb->protocol == htons(ETH_P_IP))
258 		return iph->tos;
259 	else if (skb->protocol == htons(ETH_P_IPV6))
260 		return ipv6_get_dsfield((const struct ipv6hdr *)iph);
261 	else
262 		return 0;
263 }
264 
265 /* Propogate ECN bits out */
266 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
267 				     const struct sk_buff *skb)
268 {
269 	u8 inner = ip_tunnel_get_dsfield(iph, skb);
270 
271 	return INET_ECN_encapsulate(tos, inner);
272 }
273 
274 int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto,
275 			 bool xnet);
276 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
277 		   __be32 src, __be32 dst, u8 proto,
278 		   u8 tos, u8 ttl, __be16 df, bool xnet);
279 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
280 					     gfp_t flags);
281 
282 struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
283 
284 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
285 {
286 	if (pkt_len > 0) {
287 		struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
288 
289 		u64_stats_update_begin(&tstats->syncp);
290 		tstats->tx_bytes += pkt_len;
291 		tstats->tx_packets++;
292 		u64_stats_update_end(&tstats->syncp);
293 		put_cpu_ptr(tstats);
294 	} else {
295 		struct net_device_stats *err_stats = &dev->stats;
296 
297 		if (pkt_len < 0) {
298 			err_stats->tx_errors++;
299 			err_stats->tx_aborted_errors++;
300 		} else {
301 			err_stats->tx_dropped++;
302 		}
303 	}
304 }
305 
306 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
307 {
308 	return info + 1;
309 }
310 
311 static inline void ip_tunnel_info_opts_get(void *to,
312 					   const struct ip_tunnel_info *info)
313 {
314 	memcpy(to, info + 1, info->options_len);
315 }
316 
317 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
318 					   const void *from, int len)
319 {
320 	memcpy(ip_tunnel_info_opts(info), from, len);
321 	info->options_len = len;
322 }
323 
324 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
325 {
326 	return (struct ip_tunnel_info *)lwtstate->data;
327 }
328 
329 extern struct static_key ip_tunnel_metadata_cnt;
330 
331 /* Returns > 0 if metadata should be collected */
332 static inline int ip_tunnel_collect_metadata(void)
333 {
334 	return static_key_false(&ip_tunnel_metadata_cnt);
335 }
336 
337 void __init ip_tunnel_core_init(void);
338 
339 void ip_tunnel_need_metadata(void);
340 void ip_tunnel_unneed_metadata(void);
341 
342 #else /* CONFIG_INET */
343 
344 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
345 {
346 	return NULL;
347 }
348 
349 static inline void ip_tunnel_need_metadata(void)
350 {
351 }
352 
353 static inline void ip_tunnel_unneed_metadata(void)
354 {
355 }
356 
357 #endif /* CONFIG_INET */
358 
359 #endif /* __NET_IP_TUNNELS_H */
360