xref: /openbmc/linux/include/net/ip_tunnels.h (revision 7f9562a1f405306eacb97f95d78cb996e33f27f5)
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 
17 #if IS_ENABLED(CONFIG_IPV6)
18 #include <net/ipv6.h>
19 #include <net/ip6_fib.h>
20 #include <net/ip6_route.h>
21 #endif
22 
23 /* Keep error state on tunnel for 30 sec */
24 #define IPTUNNEL_ERR_TIMEO	(30*HZ)
25 
26 /* Used to memset ip_tunnel padding. */
27 #define IP_TUNNEL_KEY_SIZE	offsetofend(struct ip_tunnel_key, tp_dst)
28 
29 /* Used to memset ipv4 address padding. */
30 #define IP_TUNNEL_KEY_IPV4_PAD	offsetofend(struct ip_tunnel_key, u.ipv4.dst)
31 #define IP_TUNNEL_KEY_IPV4_PAD_LEN				\
32 	(FIELD_SIZEOF(struct ip_tunnel_key, u) -		\
33 	 FIELD_SIZEOF(struct ip_tunnel_key, u.ipv4))
34 
35 struct ip_tunnel_key {
36 	__be64			tun_id;
37 	union {
38 		struct {
39 			__be32	src;
40 			__be32	dst;
41 		} ipv4;
42 		struct {
43 			struct in6_addr src;
44 			struct in6_addr dst;
45 		} ipv6;
46 	} u;
47 	__be16			tun_flags;
48 	u8			tos;		/* TOS for IPv4, TC for IPv6 */
49 	u8			ttl;		/* TTL for IPv4, HL for IPv6 */
50 	__be16			tp_src;
51 	__be16			tp_dst;
52 };
53 
54 /* Flags for ip_tunnel_info mode. */
55 #define IP_TUNNEL_INFO_TX	0x01	/* represents tx tunnel parameters */
56 #define IP_TUNNEL_INFO_IPV6	0x02	/* key contains IPv6 addresses */
57 
58 struct ip_tunnel_info {
59 	struct ip_tunnel_key	key;
60 	const void		*options;
61 	u8			options_len;
62 	u8			mode;
63 };
64 
65 /* 6rd prefix/relay information */
66 #ifdef CONFIG_IPV6_SIT_6RD
67 struct ip_tunnel_6rd_parm {
68 	struct in6_addr		prefix;
69 	__be32			relay_prefix;
70 	u16			prefixlen;
71 	u16			relay_prefixlen;
72 };
73 #endif
74 
75 struct ip_tunnel_encap {
76 	u16			type;
77 	u16			flags;
78 	__be16			sport;
79 	__be16			dport;
80 };
81 
82 struct ip_tunnel_prl_entry {
83 	struct ip_tunnel_prl_entry __rcu *next;
84 	__be32				addr;
85 	u16				flags;
86 	struct rcu_head			rcu_head;
87 };
88 
89 struct ip_tunnel_dst {
90 	struct dst_entry __rcu 		*dst;
91 	__be32				 saddr;
92 };
93 
94 struct metadata_dst;
95 
96 struct ip_tunnel {
97 	struct ip_tunnel __rcu	*next;
98 	struct hlist_node hash_node;
99 	struct net_device	*dev;
100 	struct net		*net;	/* netns for packet i/o */
101 
102 	int		err_count;	/* Number of arrived ICMP errors */
103 	unsigned long	err_time;	/* Time when the last ICMP error
104 					 * arrived */
105 
106 	/* These four fields used only by GRE */
107 	u32		i_seqno;	/* The last seen seqno	*/
108 	u32		o_seqno;	/* The last output seqno */
109 	int		tun_hlen;	/* Precalculated header length */
110 	int		mlink;
111 
112 	struct ip_tunnel_dst __percpu *dst_cache;
113 
114 	struct ip_tunnel_parm parms;
115 
116 	int		encap_hlen;	/* Encap header length (FOU,GUE) */
117 	struct ip_tunnel_encap encap;
118 
119 	int		hlen;		/* tun_hlen + encap_hlen */
120 
121 	/* for SIT */
122 #ifdef CONFIG_IPV6_SIT_6RD
123 	struct ip_tunnel_6rd_parm ip6rd;
124 #endif
125 	struct ip_tunnel_prl_entry __rcu *prl;	/* potential router list */
126 	unsigned int		prl_count;	/* # of entries in PRL */
127 	int			ip_tnl_net_id;
128 	struct gro_cells	gro_cells;
129 	bool			collect_md;
130 };
131 
132 #define TUNNEL_CSUM		__cpu_to_be16(0x01)
133 #define TUNNEL_ROUTING		__cpu_to_be16(0x02)
134 #define TUNNEL_KEY		__cpu_to_be16(0x04)
135 #define TUNNEL_SEQ		__cpu_to_be16(0x08)
136 #define TUNNEL_STRICT		__cpu_to_be16(0x10)
137 #define TUNNEL_REC		__cpu_to_be16(0x20)
138 #define TUNNEL_VERSION		__cpu_to_be16(0x40)
139 #define TUNNEL_NO_KEY		__cpu_to_be16(0x80)
140 #define TUNNEL_DONT_FRAGMENT    __cpu_to_be16(0x0100)
141 #define TUNNEL_OAM		__cpu_to_be16(0x0200)
142 #define TUNNEL_CRIT_OPT		__cpu_to_be16(0x0400)
143 #define TUNNEL_GENEVE_OPT	__cpu_to_be16(0x0800)
144 #define TUNNEL_VXLAN_OPT	__cpu_to_be16(0x1000)
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_info_init(struct ip_tunnel_info *tun_info,
184 					 __be32 saddr, __be32 daddr,
185 					 u8 tos, u8 ttl,
186 					 __be16 tp_src, __be16 tp_dst,
187 					 __be64 tun_id, __be16 tun_flags,
188 					 const void *opts, u8 opts_len)
189 {
190 	tun_info->key.tun_id = tun_id;
191 	tun_info->key.u.ipv4.src = saddr;
192 	tun_info->key.u.ipv4.dst = daddr;
193 	memset((unsigned char *)&tun_info->key + IP_TUNNEL_KEY_IPV4_PAD,
194 	       0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
195 	tun_info->key.tos = tos;
196 	tun_info->key.ttl = ttl;
197 	tun_info->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 	tun_info->key.tp_src = tp_src;
204 	tun_info->key.tp_dst = tp_dst;
205 
206 	/* Clear struct padding. */
207 	if (sizeof(tun_info->key) != IP_TUNNEL_KEY_SIZE)
208 		memset((unsigned char *)&tun_info->key + IP_TUNNEL_KEY_SIZE,
209 		       0, sizeof(tun_info->key) - IP_TUNNEL_KEY_SIZE);
210 
211 	tun_info->options = opts;
212 	tun_info->options_len = opts_len;
213 
214 	tun_info->mode = 0;
215 }
216 
217 static inline void ip_tunnel_info_init(struct ip_tunnel_info *tun_info,
218 				       const struct iphdr *iph,
219 				       __be16 tp_src, __be16 tp_dst,
220 				       __be64 tun_id, __be16 tun_flags,
221 				       const void *opts, u8 opts_len)
222 {
223 	__ip_tunnel_info_init(tun_info, iph->saddr, iph->daddr,
224 			      iph->tos, iph->ttl, tp_src, tp_dst,
225 			      tun_id, tun_flags, opts, opts_len);
226 }
227 
228 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
229 					       *tun_info)
230 {
231 	return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
232 }
233 
234 #ifdef CONFIG_INET
235 
236 int ip_tunnel_init(struct net_device *dev);
237 void ip_tunnel_uninit(struct net_device *dev);
238 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
239 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
240 int ip_tunnel_get_iflink(const struct net_device *dev);
241 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
242 		       struct rtnl_link_ops *ops, char *devname);
243 
244 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
245 
246 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
247 		    const struct iphdr *tnl_params, const u8 protocol);
248 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
249 int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
250 		    u8 *protocol, struct flowi4 *fl4);
251 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
252 
253 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
254 						struct rtnl_link_stats64 *tot);
255 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
256 				   int link, __be16 flags,
257 				   __be32 remote, __be32 local,
258 				   __be32 key);
259 
260 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
261 		  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
262 		  bool log_ecn_error);
263 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
264 			 struct ip_tunnel_parm *p);
265 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
266 		      struct ip_tunnel_parm *p);
267 void ip_tunnel_setup(struct net_device *dev, int net_id);
268 void ip_tunnel_dst_reset_all(struct ip_tunnel *t);
269 int ip_tunnel_encap_setup(struct ip_tunnel *t,
270 			  struct ip_tunnel_encap *ipencap);
271 
272 /* Extract dsfield from inner protocol */
273 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
274 				       const struct sk_buff *skb)
275 {
276 	if (skb->protocol == htons(ETH_P_IP))
277 		return iph->tos;
278 	else if (skb->protocol == htons(ETH_P_IPV6))
279 		return ipv6_get_dsfield((const struct ipv6hdr *)iph);
280 	else
281 		return 0;
282 }
283 
284 /* Propogate ECN bits out */
285 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
286 				     const struct sk_buff *skb)
287 {
288 	u8 inner = ip_tunnel_get_dsfield(iph, skb);
289 
290 	return INET_ECN_encapsulate(tos, inner);
291 }
292 
293 int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto);
294 int iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
295 		  __be32 src, __be32 dst, u8 proto,
296 		  u8 tos, u8 ttl, __be16 df, bool xnet);
297 
298 struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb, bool gre_csum,
299 					 int gso_type_mask);
300 
301 static inline void iptunnel_xmit_stats(int err,
302 				       struct net_device_stats *err_stats,
303 				       struct pcpu_sw_netstats __percpu *stats)
304 {
305 	if (err > 0) {
306 		struct pcpu_sw_netstats *tstats = this_cpu_ptr(stats);
307 
308 		u64_stats_update_begin(&tstats->syncp);
309 		tstats->tx_bytes += err;
310 		tstats->tx_packets++;
311 		u64_stats_update_end(&tstats->syncp);
312 	} else if (err < 0) {
313 		err_stats->tx_errors++;
314 		err_stats->tx_aborted_errors++;
315 	} else {
316 		err_stats->tx_dropped++;
317 	}
318 }
319 
320 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info, size_t n)
321 {
322 	return info + 1;
323 }
324 
325 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
326 {
327 	return (struct ip_tunnel_info *)lwtstate->data;
328 }
329 
330 extern struct static_key ip_tunnel_metadata_cnt;
331 
332 /* Returns > 0 if metadata should be collected */
333 static inline int ip_tunnel_collect_metadata(void)
334 {
335 	return static_key_false(&ip_tunnel_metadata_cnt);
336 }
337 
338 void __init ip_tunnel_core_init(void);
339 
340 void ip_tunnel_need_metadata(void);
341 void ip_tunnel_unneed_metadata(void);
342 
343 #else /* CONFIG_INET */
344 
345 static inline struct ip_tunnel_info *lwt_tun_info(struct lwtunnel_state *lwtstate)
346 {
347 	return NULL;
348 }
349 
350 static inline void ip_tunnel_need_metadata(void)
351 {
352 }
353 
354 static inline void ip_tunnel_unneed_metadata(void)
355 {
356 }
357 
358 #endif /* CONFIG_INET */
359 
360 #endif /* __NET_IP_TUNNELS_H */
361