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 enum {
20 LWTUNNEL_XMIT_DONE,
21 LWTUNNEL_XMIT_CONTINUE,
22 };
23
24
25 struct 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
36 struct 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
54 void lwtstate_free(struct lwtunnel_state *lws);
55
56 static inline struct lwtunnel_state *
lwtstate_get(struct lwtunnel_state * lws)57 lwtstate_get(struct lwtunnel_state *lws)
58 {
59 if (lws)
60 atomic_inc(&lws->refcnt);
61
62 return lws;
63 }
64
lwtstate_put(struct lwtunnel_state * lws)65 static 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
lwtunnel_output_redirect(struct lwtunnel_state * lwtstate)74 static 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
lwtunnel_input_redirect(struct lwtunnel_state * lwtstate)82 static 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
lwtunnel_xmit_redirect(struct lwtunnel_state * lwtstate)90 static 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
lwtunnel_headroom(struct lwtunnel_state * lwtstate,unsigned int mtu)98 static 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
108 int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
109 unsigned int num);
110 int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
111 unsigned int num);
112 int lwtunnel_valid_encap_type(u16 encap_type,
113 struct netlink_ext_ack *extack);
114 int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
115 struct netlink_ext_ack *extack);
116 int 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);
121 int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate,
122 int encap_attr, int encap_type_attr);
123 int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
124 struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
125 int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
126 int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
127 int lwtunnel_input(struct sk_buff *skb);
128 int lwtunnel_xmit(struct sk_buff *skb);
129 int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
130 bool ingress);
131
lwtunnel_set_redirect(struct dst_entry * dst)132 static 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
lwtstate_free(struct lwtunnel_state * lws)145 static inline void lwtstate_free(struct lwtunnel_state *lws)
146 {
147 }
148
149 static inline struct lwtunnel_state *
lwtstate_get(struct lwtunnel_state * lws)150 lwtstate_get(struct lwtunnel_state *lws)
151 {
152 return lws;
153 }
154
lwtstate_put(struct lwtunnel_state * lws)155 static inline void lwtstate_put(struct lwtunnel_state *lws)
156 {
157 }
158
lwtunnel_output_redirect(struct lwtunnel_state * lwtstate)159 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
160 {
161 return false;
162 }
163
lwtunnel_input_redirect(struct lwtunnel_state * lwtstate)164 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
165 {
166 return false;
167 }
168
lwtunnel_xmit_redirect(struct lwtunnel_state * lwtstate)169 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
170 {
171 return false;
172 }
173
lwtunnel_set_redirect(struct dst_entry * dst)174 static inline void lwtunnel_set_redirect(struct dst_entry *dst)
175 {
176 }
177
lwtunnel_headroom(struct lwtunnel_state * lwtstate,unsigned int mtu)178 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
179 unsigned int mtu)
180 {
181 return 0;
182 }
183
lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops * op,unsigned int num)184 static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
185 unsigned int num)
186 {
187 return -EOPNOTSUPP;
188
189 }
190
lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops * op,unsigned int num)191 static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
192 unsigned int num)
193 {
194 return -EOPNOTSUPP;
195 }
196
lwtunnel_valid_encap_type(u16 encap_type,struct netlink_ext_ack * extack)197 static 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 }
lwtunnel_valid_encap_type_attr(struct nlattr * attr,int len,struct netlink_ext_ack * extack)203 static 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
lwtunnel_build_state(u16 encap_type,struct nlattr * encap,unsigned int family,const void * cfg,struct lwtunnel_state ** lws,struct netlink_ext_ack * extack)212 static 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
lwtunnel_fill_encap(struct sk_buff * skb,struct lwtunnel_state * lwtstate,int encap_attr,int encap_type_attr)221 static inline int lwtunnel_fill_encap(struct sk_buff *skb,
222 struct lwtunnel_state *lwtstate,
223 int encap_attr, int encap_type_attr)
224 {
225 return 0;
226 }
227
lwtunnel_get_encap_size(struct lwtunnel_state * lwtstate)228 static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
229 {
230 return 0;
231 }
232
lwtunnel_state_alloc(int hdr_len)233 static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
234 {
235 return NULL;
236 }
237
lwtunnel_cmp_encap(struct lwtunnel_state * a,struct lwtunnel_state * b)238 static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
239 struct lwtunnel_state *b)
240 {
241 return 0;
242 }
243
lwtunnel_output(struct net * net,struct sock * sk,struct sk_buff * skb)244 static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
245 {
246 return -EOPNOTSUPP;
247 }
248
lwtunnel_input(struct sk_buff * skb)249 static inline int lwtunnel_input(struct sk_buff *skb)
250 {
251 return -EOPNOTSUPP;
252 }
253
lwtunnel_xmit(struct sk_buff * skb)254 static inline int lwtunnel_xmit(struct sk_buff *skb)
255 {
256 return -EOPNOTSUPP;
257 }
258
259 #endif /* CONFIG_LWTUNNEL */
260
261 #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
262
263 #endif /* __NET_LWTUNNEL_H */
264