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Linux kernel mirror (for testing)
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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
19/* LWTUNNEL_XMIT_CONTINUE should be distinguishable from dst_output return
20 * values (NET_XMIT_xxx and NETDEV_TX_xxx in linux/netdevice.h) for safety.
21 */
22enum {
23 LWTUNNEL_XMIT_DONE,
24 LWTUNNEL_XMIT_CONTINUE = 0x100,
25};
26
27
28struct lwtunnel_state {
29 __u16 type;
30 __u16 flags;
31 __u16 headroom;
32 atomic_t refcnt;
33 int (*orig_output)(struct net *net, struct sock *sk, struct sk_buff *skb);
34 int (*orig_input)(struct sk_buff *);
35 struct rcu_head rcu;
36 __u8 data[];
37};
38
39struct lwtunnel_encap_ops {
40 int (*build_state)(struct net *net, struct nlattr *encap,
41 unsigned int family, const void *cfg,
42 struct lwtunnel_state **ts,
43 struct netlink_ext_ack *extack);
44 void (*destroy_state)(struct lwtunnel_state *lws);
45 int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
46 int (*input)(struct sk_buff *skb);
47 int (*fill_encap)(struct sk_buff *skb,
48 struct lwtunnel_state *lwtstate);
49 int (*get_encap_size)(struct lwtunnel_state *lwtstate);
50 int (*cmp_encap)(struct lwtunnel_state *a, struct lwtunnel_state *b);
51 int (*xmit)(struct sk_buff *skb);
52
53 struct module *owner;
54};
55
56#ifdef CONFIG_LWTUNNEL
57
58DECLARE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled);
59
60void lwtstate_free(struct lwtunnel_state *lws);
61
62static inline struct lwtunnel_state *
63lwtstate_get(struct lwtunnel_state *lws)
64{
65 if (lws)
66 atomic_inc(&lws->refcnt);
67
68 return lws;
69}
70
71static inline void lwtstate_put(struct lwtunnel_state *lws)
72{
73 if (!lws)
74 return;
75
76 if (atomic_dec_and_test(&lws->refcnt))
77 lwtstate_free(lws);
78}
79
80static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
81{
82 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT))
83 return true;
84
85 return false;
86}
87
88static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
89{
90 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT))
91 return true;
92
93 return false;
94}
95
96static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
97{
98 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT))
99 return true;
100
101 return false;
102}
103
104static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
105 unsigned int mtu)
106{
107 if ((lwtunnel_xmit_redirect(lwtstate) ||
108 lwtunnel_output_redirect(lwtstate)) && lwtstate->headroom < mtu)
109 return lwtstate->headroom;
110
111 return 0;
112}
113
114int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
115 unsigned int num);
116int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
117 unsigned int num);
118int lwtunnel_valid_encap_type(u16 encap_type,
119 struct netlink_ext_ack *extack,
120 bool rtnl_is_held);
121int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
122 struct netlink_ext_ack *extack,
123 bool rtnl_is_held);
124int lwtunnel_build_state(struct net *net, u16 encap_type,
125 struct nlattr *encap,
126 unsigned int family, const void *cfg,
127 struct lwtunnel_state **lws,
128 struct netlink_ext_ack *extack);
129int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate,
130 int encap_attr, int encap_type_attr);
131int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
132struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
133int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
134int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
135int lwtunnel_input(struct sk_buff *skb);
136int lwtunnel_xmit(struct sk_buff *skb);
137int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
138 bool ingress);
139
140static inline void lwtunnel_set_redirect(struct dst_entry *dst)
141{
142 if (lwtunnel_output_redirect(dst->lwtstate)) {
143 dst->lwtstate->orig_output = dst->output;
144 dst->output = lwtunnel_output;
145 }
146 if (lwtunnel_input_redirect(dst->lwtstate)) {
147 dst->lwtstate->orig_input = dst->input;
148 dst->input = lwtunnel_input;
149 }
150}
151#else
152
153static inline void lwtstate_free(struct lwtunnel_state *lws)
154{
155}
156
157static inline struct lwtunnel_state *
158lwtstate_get(struct lwtunnel_state *lws)
159{
160 return lws;
161}
162
163static inline void lwtstate_put(struct lwtunnel_state *lws)
164{
165}
166
167static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
168{
169 return false;
170}
171
172static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
173{
174 return false;
175}
176
177static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
178{
179 return false;
180}
181
182static inline void lwtunnel_set_redirect(struct dst_entry *dst)
183{
184}
185
186static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
187 unsigned int mtu)
188{
189 return 0;
190}
191
192static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
193 unsigned int num)
194{
195 return -EOPNOTSUPP;
196
197}
198
199static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
200 unsigned int num)
201{
202 return -EOPNOTSUPP;
203}
204
205static inline int lwtunnel_valid_encap_type(u16 encap_type,
206 struct netlink_ext_ack *extack,
207 bool rtnl_is_held)
208{
209 NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel");
210 return -EOPNOTSUPP;
211}
212static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
213 struct netlink_ext_ack *extack,
214 bool rtnl_is_held)
215{
216 /* return 0 since we are not walking attr looking for
217 * RTA_ENCAP_TYPE attribute on nexthops.
218 */
219 return 0;
220}
221
222static inline int lwtunnel_build_state(struct net *net, u16 encap_type,
223 struct nlattr *encap,
224 unsigned int family, const void *cfg,
225 struct lwtunnel_state **lws,
226 struct netlink_ext_ack *extack)
227{
228 return -EOPNOTSUPP;
229}
230
231static inline int lwtunnel_fill_encap(struct sk_buff *skb,
232 struct lwtunnel_state *lwtstate,
233 int encap_attr, int encap_type_attr)
234{
235 return 0;
236}
237
238static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
239{
240 return 0;
241}
242
243static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
244{
245 return NULL;
246}
247
248static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
249 struct lwtunnel_state *b)
250{
251 return 0;
252}
253
254static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
255{
256 return -EOPNOTSUPP;
257}
258
259static inline int lwtunnel_input(struct sk_buff *skb)
260{
261 return -EOPNOTSUPP;
262}
263
264static inline int lwtunnel_xmit(struct sk_buff *skb)
265{
266 return -EOPNOTSUPP;
267}
268
269#endif /* CONFIG_LWTUNNEL */
270
271#define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
272
273#endif /* __NET_LWTUNNEL_H */