1/* SPDX-License-Identifier: GPL-2.0 */
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/* lw tunnel state flags */
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[0];
34};
35
36struct lwtunnel_encap_ops {
37 int (*build_state)(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
54void lwtstate_free(struct lwtunnel_state *lws);
55
56static inline struct lwtunnel_state *
57lwtstate_get(struct lwtunnel_state *lws)
58{
59 if (lws)
60 atomic_inc(&lws->refcnt);
61
62 return lws;
63}
64
65static inline void lwtstate_put(struct lwtunnel_state *lws)
66{
67 if (!lws)
68 return;
69
70 if (atomic_dec_and_test(&lws->refcnt))
71 lwtstate_free(lws);
72}
73
74static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
75{
76 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT))
77 return true;
78
79 return false;
80}
81
82static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
83{
84 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT))
85 return true;
86
87 return false;
88}
89
90static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
91{
92 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT))
93 return true;
94
95 return false;
96}
97
98static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
99 unsigned int mtu)
100{
101 if ((lwtunnel_xmit_redirect(lwtstate) ||
102 lwtunnel_output_redirect(lwtstate)) && lwtstate->headroom < mtu)
103 return lwtstate->headroom;
104
105 return 0;
106}
107
108int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
109 unsigned int num);
110int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
111 unsigned int num);
112int lwtunnel_valid_encap_type(u16 encap_type,
113 struct netlink_ext_ack *extack);
114int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
115 struct netlink_ext_ack *extack);
116int lwtunnel_build_state(u16 encap_type,
117 struct nlattr *encap,
118 unsigned int family, const void *cfg,
119 struct lwtunnel_state **lws,
120 struct netlink_ext_ack *extack);
121int lwtunnel_fill_encap(struct sk_buff *skb,
122 struct lwtunnel_state *lwtstate);
123int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
124struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
125int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
126int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
127int lwtunnel_input(struct sk_buff *skb);
128int lwtunnel_xmit(struct sk_buff *skb);
129int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
130 bool ingress);
131
132static inline void lwtunnel_set_redirect(struct dst_entry *dst)
133{
134 if (lwtunnel_output_redirect(dst->lwtstate)) {
135 dst->lwtstate->orig_output = dst->output;
136 dst->output = lwtunnel_output;
137 }
138 if (lwtunnel_input_redirect(dst->lwtstate)) {
139 dst->lwtstate->orig_input = dst->input;
140 dst->input = lwtunnel_input;
141 }
142}
143#else
144
145static inline void lwtstate_free(struct lwtunnel_state *lws)
146{
147}
148
149static inline struct lwtunnel_state *
150lwtstate_get(struct lwtunnel_state *lws)
151{
152 return lws;
153}
154
155static inline void lwtstate_put(struct lwtunnel_state *lws)
156{
157}
158
159static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
160{
161 return false;
162}
163
164static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
165{
166 return false;
167}
168
169static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
170{
171 return false;
172}
173
174static inline void lwtunnel_set_redirect(struct dst_entry *dst)
175{
176}
177
178static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
179 unsigned int mtu)
180{
181 return 0;
182}
183
184static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
185 unsigned int num)
186{
187 return -EOPNOTSUPP;
188
189}
190
191static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
192 unsigned int num)
193{
194 return -EOPNOTSUPP;
195}
196
197static inline int lwtunnel_valid_encap_type(u16 encap_type,
198 struct netlink_ext_ack *extack)
199{
200 NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel");
201 return -EOPNOTSUPP;
202}
203static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
204 struct netlink_ext_ack *extack)
205{
206 /* return 0 since we are not walking attr looking for
207 * RTA_ENCAP_TYPE attribute on nexthops.
208 */
209 return 0;
210}
211
212static inline int lwtunnel_build_state(u16 encap_type,
213 struct nlattr *encap,
214 unsigned int family, const void *cfg,
215 struct lwtunnel_state **lws,
216 struct netlink_ext_ack *extack)
217{
218 return -EOPNOTSUPP;
219}
220
221static inline int lwtunnel_fill_encap(struct sk_buff *skb,
222 struct lwtunnel_state *lwtstate)
223{
224 return 0;
225}
226
227static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
228{
229 return 0;
230}
231
232static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
233{
234 return NULL;
235}
236
237static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
238 struct lwtunnel_state *b)
239{
240 return 0;
241}
242
243static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
244{
245 return -EOPNOTSUPP;
246}
247
248static inline int lwtunnel_input(struct sk_buff *skb)
249{
250 return -EOPNOTSUPP;
251}
252
253static inline int lwtunnel_xmit(struct sk_buff *skb)
254{
255 return -EOPNOTSUPP;
256}
257
258#endif /* CONFIG_LWTUNNEL */
259
260#define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
261
262#endif /* __NET_LWTUNNEL_H */
263