xref: /linux/include/net/ip_tunnels.h (revision 54c9ee39923c0ffa27b99a1b7321e0d07408c97b)
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/types.h>
8 #include <linux/u64_stats_sync.h>
9 #include <net/dsfield.h>
10 #include <net/gro_cells.h>
11 #include <net/inet_ecn.h>
12 #include <net/netns/generic.h>
13 #include <net/rtnetlink.h>
14 #include <net/lwtunnel.h>
15 
16 #if IS_ENABLED(CONFIG_IPV6)
17 #include <net/ipv6.h>
18 #include <net/ip6_fib.h>
19 #include <net/ip6_route.h>
20 #endif
21 
22 /* Keep error state on tunnel for 30 sec */
23 #define IPTUNNEL_ERR_TIMEO	(30*HZ)
24 
25 /* Used to memset ip_tunnel padding. */
26 #define IP_TUNNEL_KEY_SIZE					\
27 	(offsetof(struct ip_tunnel_key, tp_dst) +		\
28 	 FIELD_SIZEOF(struct ip_tunnel_key, tp_dst))
29 
30 struct ip_tunnel_key {
31 	__be64			tun_id;
32 	__be32			ipv4_src;
33 	__be32			ipv4_dst;
34 	__be16			tun_flags;
35 	__u8			ipv4_tos;
36 	__u8			ipv4_ttl;
37 	__be16			tp_src;
38 	__be16			tp_dst;
39 } __packed __aligned(4); /* Minimize padding. */
40 
41 /* Indicates whether the tunnel info structure represents receive
42  * or transmit tunnel parameters.
43  */
44 enum {
45 	IP_TUNNEL_INFO_RX,
46 	IP_TUNNEL_INFO_TX,
47 };
48 
49 struct ip_tunnel_info {
50 	struct ip_tunnel_key	key;
51 	const void		*options;
52 	u8			options_len;
53 	u8			mode;
54 };
55 
56 /* 6rd prefix/relay information */
57 #ifdef CONFIG_IPV6_SIT_6RD
58 struct ip_tunnel_6rd_parm {
59 	struct in6_addr		prefix;
60 	__be32			relay_prefix;
61 	u16			prefixlen;
62 	u16			relay_prefixlen;
63 };
64 #endif
65 
66 struct ip_tunnel_encap {
67 	__u16			type;
68 	__u16			flags;
69 	__be16			sport;
70 	__be16			dport;
71 };
72 
73 struct ip_tunnel_prl_entry {
74 	struct ip_tunnel_prl_entry __rcu *next;
75 	__be32				addr;
76 	u16				flags;
77 	struct rcu_head			rcu_head;
78 };
79 
80 struct ip_tunnel_dst {
81 	struct dst_entry __rcu 		*dst;
82 	__be32				 saddr;
83 };
84 
85 struct ip_tunnel {
86 	struct ip_tunnel __rcu	*next;
87 	struct hlist_node hash_node;
88 	struct net_device	*dev;
89 	struct net		*net;	/* netns for packet i/o */
90 
91 	int		err_count;	/* Number of arrived ICMP errors */
92 	unsigned long	err_time;	/* Time when the last ICMP error
93 					 * arrived */
94 
95 	/* These four fields used only by GRE */
96 	__u32		i_seqno;	/* The last seen seqno	*/
97 	__u32		o_seqno;	/* The last output seqno */
98 	int		tun_hlen;	/* Precalculated header length */
99 	int		mlink;
100 
101 	struct ip_tunnel_dst __percpu *dst_cache;
102 
103 	struct ip_tunnel_parm parms;
104 
105 	int		encap_hlen;	/* Encap header length (FOU,GUE) */
106 	struct ip_tunnel_encap encap;
107 
108 	int		hlen;		/* tun_hlen + encap_hlen */
109 
110 	/* for SIT */
111 #ifdef CONFIG_IPV6_SIT_6RD
112 	struct ip_tunnel_6rd_parm ip6rd;
113 #endif
114 	struct ip_tunnel_prl_entry __rcu *prl;	/* potential router list */
115 	unsigned int		prl_count;	/* # of entries in PRL */
116 	int			ip_tnl_net_id;
117 	struct gro_cells	gro_cells;
118 };
119 
120 #define TUNNEL_CSUM		__cpu_to_be16(0x01)
121 #define TUNNEL_ROUTING		__cpu_to_be16(0x02)
122 #define TUNNEL_KEY		__cpu_to_be16(0x04)
123 #define TUNNEL_SEQ		__cpu_to_be16(0x08)
124 #define TUNNEL_STRICT		__cpu_to_be16(0x10)
125 #define TUNNEL_REC		__cpu_to_be16(0x20)
126 #define TUNNEL_VERSION		__cpu_to_be16(0x40)
127 #define TUNNEL_NO_KEY		__cpu_to_be16(0x80)
128 #define TUNNEL_DONT_FRAGMENT    __cpu_to_be16(0x0100)
129 #define TUNNEL_OAM		__cpu_to_be16(0x0200)
130 #define TUNNEL_CRIT_OPT		__cpu_to_be16(0x0400)
131 #define TUNNEL_GENEVE_OPT	__cpu_to_be16(0x0800)
132 #define TUNNEL_VXLAN_OPT	__cpu_to_be16(0x1000)
133 
134 #define TUNNEL_OPTIONS_PRESENT	(TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT)
135 
136 struct tnl_ptk_info {
137 	__be16 flags;
138 	__be16 proto;
139 	__be32 key;
140 	__be32 seq;
141 };
142 
143 #define PACKET_RCVD	0
144 #define PACKET_REJECT	1
145 
146 #define IP_TNL_HASH_BITS   7
147 #define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
148 
149 struct ip_tunnel_net {
150 	struct net_device *fb_tunnel_dev;
151 	struct hlist_head tunnels[IP_TNL_HASH_SIZE];
152 };
153 
154 struct ip_tunnel_encap_ops {
155 	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
156 	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
157 			    u8 *protocol, struct flowi4 *fl4);
158 };
159 
160 #define MAX_IPTUN_ENCAP_OPS 8
161 
162 extern const struct ip_tunnel_encap_ops __rcu *
163 		iptun_encaps[MAX_IPTUN_ENCAP_OPS];
164 
165 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
166 			    unsigned int num);
167 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
168 			    unsigned int num);
169 
170 static inline void __ip_tunnel_info_init(struct ip_tunnel_info *tun_info,
171 					 __be32 saddr, __be32 daddr,
172 					 u8 tos, u8 ttl,
173 					 __be16 tp_src, __be16 tp_dst,
174 					 __be64 tun_id, __be16 tun_flags,
175 					 const void *opts, u8 opts_len)
176 {
177 	tun_info->key.tun_id = tun_id;
178 	tun_info->key.ipv4_src = saddr;
179 	tun_info->key.ipv4_dst = daddr;
180 	tun_info->key.ipv4_tos = tos;
181 	tun_info->key.ipv4_ttl = ttl;
182 	tun_info->key.tun_flags = tun_flags;
183 
184 	/* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
185 	 * the upper tunnel are used.
186 	 * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
187 	 */
188 	tun_info->key.tp_src = tp_src;
189 	tun_info->key.tp_dst = tp_dst;
190 
191 	/* Clear struct padding. */
192 	if (sizeof(tun_info->key) != IP_TUNNEL_KEY_SIZE)
193 		memset((unsigned char *)&tun_info->key + IP_TUNNEL_KEY_SIZE,
194 		       0, sizeof(tun_info->key) - IP_TUNNEL_KEY_SIZE);
195 
196 	tun_info->options = opts;
197 	tun_info->options_len = opts_len;
198 }
199 
200 static inline void ip_tunnel_info_init(struct ip_tunnel_info *tun_info,
201 				       const struct iphdr *iph,
202 				       __be16 tp_src, __be16 tp_dst,
203 				       __be64 tun_id, __be16 tun_flags,
204 				       const void *opts, u8 opts_len)
205 {
206 	__ip_tunnel_info_init(tun_info, iph->saddr, iph->daddr,
207 			      iph->tos, iph->ttl, tp_src, tp_dst,
208 			      tun_id, tun_flags, opts, opts_len);
209 }
210 
211 #ifdef CONFIG_INET
212 
213 int ip_tunnel_init(struct net_device *dev);
214 void ip_tunnel_uninit(struct net_device *dev);
215 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
216 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
217 int ip_tunnel_get_iflink(const struct net_device *dev);
218 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
219 		       struct rtnl_link_ops *ops, char *devname);
220 
221 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
222 
223 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
224 		    const struct iphdr *tnl_params, const u8 protocol);
225 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
226 int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
227 		    u8 *protocol, struct flowi4 *fl4);
228 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
229 
230 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
231 						struct rtnl_link_stats64 *tot);
232 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
233 				   int link, __be16 flags,
234 				   __be32 remote, __be32 local,
235 				   __be32 key);
236 
237 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
238 		  const struct tnl_ptk_info *tpi, bool log_ecn_error);
239 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
240 			 struct ip_tunnel_parm *p);
241 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
242 		      struct ip_tunnel_parm *p);
243 void ip_tunnel_setup(struct net_device *dev, int net_id);
244 void ip_tunnel_dst_reset_all(struct ip_tunnel *t);
245 int ip_tunnel_encap_setup(struct ip_tunnel *t,
246 			  struct ip_tunnel_encap *ipencap);
247 
248 /* Extract dsfield from inner protocol */
249 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
250 				       const struct sk_buff *skb)
251 {
252 	if (skb->protocol == htons(ETH_P_IP))
253 		return iph->tos;
254 	else if (skb->protocol == htons(ETH_P_IPV6))
255 		return ipv6_get_dsfield((const struct ipv6hdr *)iph);
256 	else
257 		return 0;
258 }
259 
260 /* Propogate ECN bits out */
261 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
262 				     const struct sk_buff *skb)
263 {
264 	u8 inner = ip_tunnel_get_dsfield(iph, skb);
265 
266 	return INET_ECN_encapsulate(tos, inner);
267 }
268 
269 int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto);
270 int iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
271 		  __be32 src, __be32 dst, __u8 proto,
272 		  __u8 tos, __u8 ttl, __be16 df, bool xnet);
273 
274 struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb, bool gre_csum,
275 					 int gso_type_mask);
276 
277 static inline void iptunnel_xmit_stats(int err,
278 				       struct net_device_stats *err_stats,
279 				       struct pcpu_sw_netstats __percpu *stats)
280 {
281 	if (err > 0) {
282 		struct pcpu_sw_netstats *tstats = this_cpu_ptr(stats);
283 
284 		u64_stats_update_begin(&tstats->syncp);
285 		tstats->tx_bytes += err;
286 		tstats->tx_packets++;
287 		u64_stats_update_end(&tstats->syncp);
288 	} else if (err < 0) {
289 		err_stats->tx_errors++;
290 		err_stats->tx_aborted_errors++;
291 	} else {
292 		err_stats->tx_dropped++;
293 	}
294 }
295 
296 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info, size_t n)
297 {
298 	return info + 1;
299 }
300 
301 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
302 {
303 	return (struct ip_tunnel_info *)lwtstate->data;
304 }
305 
306 extern struct static_key ip_tunnel_metadata_cnt;
307 
308 /* Returns > 0 if metadata should be collected */
309 static inline int ip_tunnel_collect_metadata(void)
310 {
311 	return static_key_false(&ip_tunnel_metadata_cnt);
312 }
313 
314 void __init ip_tunnel_core_init(void);
315 
316 void ip_tunnel_need_metadata(void);
317 void ip_tunnel_unneed_metadata(void);
318 
319 #else /* CONFIG_INET */
320 
321 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
322 {
323 	return NULL;
324 }
325 
326 static inline void ip_tunnel_need_metadata(void)
327 {
328 }
329 
330 static inline void ip_tunnel_unneed_metadata(void)
331 {
332 }
333 
334 #endif /* CONFIG_INET */
335 
336 #endif /* __NET_IP_TUNNELS_H */
337