xref: /openbmc/linux/include/net/ip_tunnels.h (revision a06c488d)
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 	u8			options_len;
61 	u8			mode;
62 };
63 
64 /* 6rd prefix/relay information */
65 #ifdef CONFIG_IPV6_SIT_6RD
66 struct ip_tunnel_6rd_parm {
67 	struct in6_addr		prefix;
68 	__be32			relay_prefix;
69 	u16			prefixlen;
70 	u16			relay_prefixlen;
71 };
72 #endif
73 
74 struct ip_tunnel_encap {
75 	u16			type;
76 	u16			flags;
77 	__be16			sport;
78 	__be16			dport;
79 };
80 
81 struct ip_tunnel_prl_entry {
82 	struct ip_tunnel_prl_entry __rcu *next;
83 	__be32				addr;
84 	u16				flags;
85 	struct rcu_head			rcu_head;
86 };
87 
88 struct ip_tunnel_dst {
89 	struct dst_entry __rcu 		*dst;
90 	__be32				 saddr;
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 ip_tunnel_dst __percpu *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 
145 #define TUNNEL_OPTIONS_PRESENT	(TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT)
146 
147 struct tnl_ptk_info {
148 	__be16 flags;
149 	__be16 proto;
150 	__be32 key;
151 	__be32 seq;
152 };
153 
154 #define PACKET_RCVD	0
155 #define PACKET_REJECT	1
156 
157 #define IP_TNL_HASH_BITS   7
158 #define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
159 
160 struct ip_tunnel_net {
161 	struct net_device *fb_tunnel_dev;
162 	struct hlist_head tunnels[IP_TNL_HASH_SIZE];
163 	struct ip_tunnel __rcu *collect_md_tun;
164 };
165 
166 struct ip_tunnel_encap_ops {
167 	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
168 	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
169 			    u8 *protocol, struct flowi4 *fl4);
170 };
171 
172 #define MAX_IPTUN_ENCAP_OPS 8
173 
174 extern const struct ip_tunnel_encap_ops __rcu *
175 		iptun_encaps[MAX_IPTUN_ENCAP_OPS];
176 
177 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
178 			    unsigned int num);
179 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
180 			    unsigned int num);
181 
182 static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
183 				      __be32 saddr, __be32 daddr,
184 				      u8 tos, u8 ttl,
185 				      __be16 tp_src, __be16 tp_dst,
186 				      __be64 tun_id, __be16 tun_flags)
187 {
188 	key->tun_id = tun_id;
189 	key->u.ipv4.src = saddr;
190 	key->u.ipv4.dst = daddr;
191 	memset((unsigned char *)key + IP_TUNNEL_KEY_IPV4_PAD,
192 	       0, IP_TUNNEL_KEY_IPV4_PAD_LEN);
193 	key->tos = tos;
194 	key->ttl = ttl;
195 	key->tun_flags = tun_flags;
196 
197 	/* For the tunnel types on the top of IPsec, the tp_src and tp_dst of
198 	 * the upper tunnel are used.
199 	 * E.g: GRE over IPSEC, the tp_src and tp_port are zero.
200 	 */
201 	key->tp_src = tp_src;
202 	key->tp_dst = tp_dst;
203 
204 	/* Clear struct padding. */
205 	if (sizeof(*key) != IP_TUNNEL_KEY_SIZE)
206 		memset((unsigned char *)key + IP_TUNNEL_KEY_SIZE,
207 		       0, sizeof(*key) - IP_TUNNEL_KEY_SIZE);
208 }
209 
210 static inline unsigned short ip_tunnel_info_af(const struct ip_tunnel_info
211 					       *tun_info)
212 {
213 	return tun_info->mode & IP_TUNNEL_INFO_IPV6 ? AF_INET6 : AF_INET;
214 }
215 
216 #ifdef CONFIG_INET
217 
218 int ip_tunnel_init(struct net_device *dev);
219 void ip_tunnel_uninit(struct net_device *dev);
220 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
221 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
222 int ip_tunnel_get_iflink(const struct net_device *dev);
223 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
224 		       struct rtnl_link_ops *ops, char *devname);
225 
226 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
227 
228 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
229 		    const struct iphdr *tnl_params, const u8 protocol);
230 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
231 int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
232 		    u8 *protocol, struct flowi4 *fl4);
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 void ip_tunnel_dst_reset_all(struct ip_tunnel *t);
251 int ip_tunnel_encap_setup(struct ip_tunnel *t,
252 			  struct ip_tunnel_encap *ipencap);
253 
254 /* Extract dsfield from inner protocol */
255 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
256 				       const struct sk_buff *skb)
257 {
258 	if (skb->protocol == htons(ETH_P_IP))
259 		return iph->tos;
260 	else if (skb->protocol == htons(ETH_P_IPV6))
261 		return ipv6_get_dsfield((const struct ipv6hdr *)iph);
262 	else
263 		return 0;
264 }
265 
266 /* Propogate ECN bits out */
267 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
268 				     const struct sk_buff *skb)
269 {
270 	u8 inner = ip_tunnel_get_dsfield(iph, skb);
271 
272 	return INET_ECN_encapsulate(tos, inner);
273 }
274 
275 int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto);
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, bool gre_csum,
283 					 int gso_type_mask);
284 
285 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
286 {
287 	if (pkt_len > 0) {
288 		struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
289 
290 		u64_stats_update_begin(&tstats->syncp);
291 		tstats->tx_bytes += pkt_len;
292 		tstats->tx_packets++;
293 		u64_stats_update_end(&tstats->syncp);
294 		put_cpu_ptr(tstats);
295 	} else {
296 		struct net_device_stats *err_stats = &dev->stats;
297 
298 		if (pkt_len < 0) {
299 			err_stats->tx_errors++;
300 			err_stats->tx_aborted_errors++;
301 		} else {
302 			err_stats->tx_dropped++;
303 		}
304 	}
305 }
306 
307 static inline void *ip_tunnel_info_opts(struct ip_tunnel_info *info)
308 {
309 	return info + 1;
310 }
311 
312 static inline void ip_tunnel_info_opts_get(void *to,
313 					   const struct ip_tunnel_info *info)
314 {
315 	memcpy(to, info + 1, info->options_len);
316 }
317 
318 static inline void ip_tunnel_info_opts_set(struct ip_tunnel_info *info,
319 					   const void *from, int len)
320 {
321 	memcpy(ip_tunnel_info_opts(info), from, len);
322 	info->options_len = len;
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