xref: /linux/include/net/ip_tunnels.h (revision 2ba9268dd603d23e17643437b2246acb6844953b)
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/ip.h>
13 #include <net/netns/generic.h>
14 #include <net/rtnetlink.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 /* 6rd prefix/relay information */
26 #ifdef CONFIG_IPV6_SIT_6RD
27 struct ip_tunnel_6rd_parm {
28 	struct in6_addr		prefix;
29 	__be32			relay_prefix;
30 	u16			prefixlen;
31 	u16			relay_prefixlen;
32 };
33 #endif
34 
35 struct ip_tunnel_encap {
36 	__u16			type;
37 	__u16			flags;
38 	__be16			sport;
39 	__be16			dport;
40 };
41 
42 struct ip_tunnel_prl_entry {
43 	struct ip_tunnel_prl_entry __rcu *next;
44 	__be32				addr;
45 	u16				flags;
46 	struct rcu_head			rcu_head;
47 };
48 
49 struct ip_tunnel_dst {
50 	struct dst_entry __rcu 		*dst;
51 	__be32				 saddr;
52 };
53 
54 struct ip_tunnel {
55 	struct ip_tunnel __rcu	*next;
56 	struct hlist_node hash_node;
57 	struct net_device	*dev;
58 	struct net		*net;	/* netns for packet i/o */
59 
60 	int		err_count;	/* Number of arrived ICMP errors */
61 	unsigned long	err_time;	/* Time when the last ICMP error
62 					 * arrived */
63 
64 	/* These four fields used only by GRE */
65 	__u32		i_seqno;	/* The last seen seqno	*/
66 	__u32		o_seqno;	/* The last output seqno */
67 	int		tun_hlen;	/* Precalculated header length */
68 	int		mlink;
69 
70 	struct ip_tunnel_dst __percpu *dst_cache;
71 
72 	struct ip_tunnel_parm parms;
73 
74 	int		encap_hlen;	/* Encap header length (FOU,GUE) */
75 	struct ip_tunnel_encap encap;
76 
77 	int		hlen;		/* tun_hlen + encap_hlen */
78 
79 	/* for SIT */
80 #ifdef CONFIG_IPV6_SIT_6RD
81 	struct ip_tunnel_6rd_parm ip6rd;
82 #endif
83 	struct ip_tunnel_prl_entry __rcu *prl;	/* potential router list */
84 	unsigned int		prl_count;	/* # of entries in PRL */
85 	int			ip_tnl_net_id;
86 	struct gro_cells	gro_cells;
87 };
88 
89 #define TUNNEL_CSUM		__cpu_to_be16(0x01)
90 #define TUNNEL_ROUTING		__cpu_to_be16(0x02)
91 #define TUNNEL_KEY		__cpu_to_be16(0x04)
92 #define TUNNEL_SEQ		__cpu_to_be16(0x08)
93 #define TUNNEL_STRICT		__cpu_to_be16(0x10)
94 #define TUNNEL_REC		__cpu_to_be16(0x20)
95 #define TUNNEL_VERSION		__cpu_to_be16(0x40)
96 #define TUNNEL_NO_KEY		__cpu_to_be16(0x80)
97 #define TUNNEL_DONT_FRAGMENT    __cpu_to_be16(0x0100)
98 #define TUNNEL_OAM		__cpu_to_be16(0x0200)
99 #define TUNNEL_CRIT_OPT		__cpu_to_be16(0x0400)
100 #define TUNNEL_GENEVE_OPT	__cpu_to_be16(0x0800)
101 #define TUNNEL_VXLAN_OPT	__cpu_to_be16(0x1000)
102 
103 #define TUNNEL_OPTIONS_PRESENT	(TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT)
104 
105 struct tnl_ptk_info {
106 	__be16 flags;
107 	__be16 proto;
108 	__be32 key;
109 	__be32 seq;
110 };
111 
112 #define PACKET_RCVD	0
113 #define PACKET_REJECT	1
114 
115 #define IP_TNL_HASH_BITS   7
116 #define IP_TNL_HASH_SIZE   (1 << IP_TNL_HASH_BITS)
117 
118 struct ip_tunnel_net {
119 	struct net_device *fb_tunnel_dev;
120 	struct hlist_head tunnels[IP_TNL_HASH_SIZE];
121 };
122 
123 struct ip_tunnel_encap_ops {
124 	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
125 	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
126 			    u8 *protocol, struct flowi4 *fl4);
127 };
128 
129 #define MAX_IPTUN_ENCAP_OPS 8
130 
131 extern const struct ip_tunnel_encap_ops __rcu *
132 		iptun_encaps[MAX_IPTUN_ENCAP_OPS];
133 
134 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op,
135 			    unsigned int num);
136 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op,
137 			    unsigned int num);
138 
139 #ifdef CONFIG_INET
140 
141 int ip_tunnel_init(struct net_device *dev);
142 void ip_tunnel_uninit(struct net_device *dev);
143 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
144 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
145 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
146 		       struct rtnl_link_ops *ops, char *devname);
147 
148 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
149 
150 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
151 		    const struct iphdr *tnl_params, const u8 protocol);
152 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
153 int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
154 		    u8 *protocol, struct flowi4 *fl4);
155 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
156 
157 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
158 						struct rtnl_link_stats64 *tot);
159 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
160 				   int link, __be16 flags,
161 				   __be32 remote, __be32 local,
162 				   __be32 key);
163 
164 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
165 		  const struct tnl_ptk_info *tpi, bool log_ecn_error);
166 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
167 			 struct ip_tunnel_parm *p);
168 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
169 		      struct ip_tunnel_parm *p);
170 void ip_tunnel_setup(struct net_device *dev, int net_id);
171 void ip_tunnel_dst_reset_all(struct ip_tunnel *t);
172 int ip_tunnel_encap_setup(struct ip_tunnel *t,
173 			  struct ip_tunnel_encap *ipencap);
174 
175 /* Extract dsfield from inner protocol */
176 static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,
177 				       const struct sk_buff *skb)
178 {
179 	if (skb->protocol == htons(ETH_P_IP))
180 		return iph->tos;
181 	else if (skb->protocol == htons(ETH_P_IPV6))
182 		return ipv6_get_dsfield((const struct ipv6hdr *)iph);
183 	else
184 		return 0;
185 }
186 
187 /* Propogate ECN bits out */
188 static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
189 				     const struct sk_buff *skb)
190 {
191 	u8 inner = ip_tunnel_get_dsfield(iph, skb);
192 
193 	return INET_ECN_encapsulate(tos, inner);
194 }
195 
196 int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto);
197 int iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
198 		  __be32 src, __be32 dst, __u8 proto,
199 		  __u8 tos, __u8 ttl, __be16 df, bool xnet);
200 
201 struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb, bool gre_csum,
202 					 int gso_type_mask);
203 
204 static inline void iptunnel_xmit_stats(int err,
205 				       struct net_device_stats *err_stats,
206 				       struct pcpu_sw_netstats __percpu *stats)
207 {
208 	if (err > 0) {
209 		struct pcpu_sw_netstats *tstats = this_cpu_ptr(stats);
210 
211 		u64_stats_update_begin(&tstats->syncp);
212 		tstats->tx_bytes += err;
213 		tstats->tx_packets++;
214 		u64_stats_update_end(&tstats->syncp);
215 	} else if (err < 0) {
216 		err_stats->tx_errors++;
217 		err_stats->tx_aborted_errors++;
218 	} else {
219 		err_stats->tx_dropped++;
220 	}
221 }
222 
223 #endif /* CONFIG_INET */
224 
225 #endif /* __NET_IP_TUNNELS_H */
226