1
2#ifndef __NET_LWTUNNEL_H
3#define __NET_LWTUNNEL_H 1
4
5#include <linux/lwtunnel.h>
6#include <linux/netdevice.h>
7#include <linux/skbuff.h>
8#include <linux/types.h>
9#include <net/route.h>
10
11#define LWTUNNEL_HASH_BITS 7
12#define LWTUNNEL_HASH_SIZE (1 << LWTUNNEL_HASH_BITS)
13
14
15#define LWTUNNEL_STATE_OUTPUT_REDIRECT BIT(0)
16#define LWTUNNEL_STATE_INPUT_REDIRECT BIT(1)
17#define LWTUNNEL_STATE_XMIT_REDIRECT BIT(2)
18
19enum {
20 LWTUNNEL_XMIT_DONE,
21 LWTUNNEL_XMIT_CONTINUE,
22};
23
24
25struct lwtunnel_state {
26 __u16 type;
27 __u16 flags;
28 __u16 headroom;
29 atomic_t refcnt;
30 int (*orig_output)(struct net *net, struct sock *sk, struct sk_buff *skb);
31 int (*orig_input)(struct sk_buff *);
32 struct rcu_head rcu;
33 __u8 data[];
34};
35
36struct lwtunnel_encap_ops {
37 int (*build_state)(struct net *net, struct nlattr *encap,
38 unsigned int family, const void *cfg,
39 struct lwtunnel_state **ts,
40 struct netlink_ext_ack *extack);
41 void (*destroy_state)(struct lwtunnel_state *lws);
42 int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
43 int (*input)(struct sk_buff *skb);
44 int (*fill_encap)(struct sk_buff *skb,
45 struct lwtunnel_state *lwtstate);
46 int (*get_encap_size)(struct lwtunnel_state *lwtstate);
47 int (*cmp_encap)(struct lwtunnel_state *a, struct lwtunnel_state *b);
48 int (*xmit)(struct sk_buff *skb);
49
50 struct module *owner;
51};
52
53#ifdef CONFIG_LWTUNNEL
54
55DECLARE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled);
56
57void lwtstate_free(struct lwtunnel_state *lws);
58
59static inline struct lwtunnel_state *
60lwtstate_get(struct lwtunnel_state *lws)
61{
62 if (lws)
63 atomic_inc(&lws->refcnt);
64
65 return lws;
66}
67
68static inline void lwtstate_put(struct lwtunnel_state *lws)
69{
70 if (!lws)
71 return;
72
73 if (atomic_dec_and_test(&lws->refcnt))
74 lwtstate_free(lws);
75}
76
77static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
78{
79 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT))
80 return true;
81
82 return false;
83}
84
85static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
86{
87 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT))
88 return true;
89
90 return false;
91}
92
93static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
94{
95 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT))
96 return true;
97
98 return false;
99}
100
101static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
102 unsigned int mtu)
103{
104 if ((lwtunnel_xmit_redirect(lwtstate) ||
105 lwtunnel_output_redirect(lwtstate)) && lwtstate->headroom < mtu)
106 return lwtstate->headroom;
107
108 return 0;
109}
110
111int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
112 unsigned int num);
113int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
114 unsigned int num);
115int lwtunnel_valid_encap_type(u16 encap_type,
116 struct netlink_ext_ack *extack);
117int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
118 struct netlink_ext_ack *extack);
119int lwtunnel_build_state(struct net *net, u16 encap_type,
120 struct nlattr *encap,
121 unsigned int family, const void *cfg,
122 struct lwtunnel_state **lws,
123 struct netlink_ext_ack *extack);
124int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate,
125 int encap_attr, int encap_type_attr);
126int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
127struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
128int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
129int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
130int lwtunnel_input(struct sk_buff *skb);
131int lwtunnel_xmit(struct sk_buff *skb);
132int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
133 bool ingress);
134
135static inline void lwtunnel_set_redirect(struct dst_entry *dst)
136{
137 if (lwtunnel_output_redirect(dst->lwtstate)) {
138 dst->lwtstate->orig_output = dst->output;
139 dst->output = lwtunnel_output;
140 }
141 if (lwtunnel_input_redirect(dst->lwtstate)) {
142 dst->lwtstate->orig_input = dst->input;
143 dst->input = lwtunnel_input;
144 }
145}
146#else
147
148static inline void lwtstate_free(struct lwtunnel_state *lws)
149{
150}
151
152static inline struct lwtunnel_state *
153lwtstate_get(struct lwtunnel_state *lws)
154{
155 return lws;
156}
157
158static inline void lwtstate_put(struct lwtunnel_state *lws)
159{
160}
161
162static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
163{
164 return false;
165}
166
167static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
168{
169 return false;
170}
171
172static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
173{
174 return false;
175}
176
177static inline void lwtunnel_set_redirect(struct dst_entry *dst)
178{
179}
180
181static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
182 unsigned int mtu)
183{
184 return 0;
185}
186
187static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
188 unsigned int num)
189{
190 return -EOPNOTSUPP;
191
192}
193
194static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
195 unsigned int num)
196{
197 return -EOPNOTSUPP;
198}
199
200static inline int lwtunnel_valid_encap_type(u16 encap_type,
201 struct netlink_ext_ack *extack)
202{
203 NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel");
204 return -EOPNOTSUPP;
205}
206static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
207 struct netlink_ext_ack *extack)
208{
209
210
211
212 return 0;
213}
214
215static inline int lwtunnel_build_state(struct net *net, u16 encap_type,
216 struct nlattr *encap,
217 unsigned int family, const void *cfg,
218 struct lwtunnel_state **lws,
219 struct netlink_ext_ack *extack)
220{
221 return -EOPNOTSUPP;
222}
223
224static inline int lwtunnel_fill_encap(struct sk_buff *skb,
225 struct lwtunnel_state *lwtstate,
226 int encap_attr, int encap_type_attr)
227{
228 return 0;
229}
230
231static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
232{
233 return 0;
234}
235
236static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
237{
238 return NULL;
239}
240
241static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
242 struct lwtunnel_state *b)
243{
244 return 0;
245}
246
247static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
248{
249 return -EOPNOTSUPP;
250}
251
252static inline int lwtunnel_input(struct sk_buff *skb)
253{
254 return -EOPNOTSUPP;
255}
256
257static inline int lwtunnel_xmit(struct sk_buff *skb)
258{
259 return -EOPNOTSUPP;
260}
261
262#endif
263
264#define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
265
266#endif
267
