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 | */ |
22 | enum { |
23 | LWTUNNEL_XMIT_DONE, |
24 | LWTUNNEL_XMIT_CONTINUE = 0x100, |
25 | }; |
26 | |
27 | |
28 | struct 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 | |
39 | struct 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 | |
58 | DECLARE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled); |
59 | |
60 | void lwtstate_free(struct lwtunnel_state *lws); |
61 | |
62 | static inline struct lwtunnel_state * |
63 | lwtstate_get(struct lwtunnel_state *lws) |
64 | { |
65 | if (lws) |
66 | atomic_inc(v: &lws->refcnt); |
67 | |
68 | return lws; |
69 | } |
70 | |
71 | static inline void lwtstate_put(struct lwtunnel_state *lws) |
72 | { |
73 | if (!lws) |
74 | return; |
75 | |
76 | if (atomic_dec_and_test(v: &lws->refcnt)) |
77 | lwtstate_free(lws); |
78 | } |
79 | |
80 | static 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 | |
88 | static 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 | |
96 | static 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 | |
104 | static 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 | |
114 | int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op, |
115 | unsigned int num); |
116 | int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op, |
117 | unsigned int num); |
118 | int lwtunnel_valid_encap_type(u16 encap_type, |
119 | struct netlink_ext_ack *extack); |
120 | int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len, |
121 | struct netlink_ext_ack *extack); |
122 | int lwtunnel_build_state(struct net *net, u16 encap_type, |
123 | struct nlattr *encap, |
124 | unsigned int family, const void *cfg, |
125 | struct lwtunnel_state **lws, |
126 | struct netlink_ext_ack *extack); |
127 | int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate, |
128 | int encap_attr, int encap_type_attr); |
129 | int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate); |
130 | struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len); |
131 | int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b); |
132 | int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb); |
133 | int lwtunnel_input(struct sk_buff *skb); |
134 | int lwtunnel_xmit(struct sk_buff *skb); |
135 | int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, |
136 | bool ingress); |
137 | |
138 | static inline void lwtunnel_set_redirect(struct dst_entry *dst) |
139 | { |
140 | if (lwtunnel_output_redirect(lwtstate: dst->lwtstate)) { |
141 | dst->lwtstate->orig_output = dst->output; |
142 | dst->output = lwtunnel_output; |
143 | } |
144 | if (lwtunnel_input_redirect(lwtstate: dst->lwtstate)) { |
145 | dst->lwtstate->orig_input = dst->input; |
146 | dst->input = lwtunnel_input; |
147 | } |
148 | } |
149 | #else |
150 | |
151 | static inline void lwtstate_free(struct lwtunnel_state *lws) |
152 | { |
153 | } |
154 | |
155 | static inline struct lwtunnel_state * |
156 | lwtstate_get(struct lwtunnel_state *lws) |
157 | { |
158 | return lws; |
159 | } |
160 | |
161 | static inline void lwtstate_put(struct lwtunnel_state *lws) |
162 | { |
163 | } |
164 | |
165 | static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate) |
166 | { |
167 | return false; |
168 | } |
169 | |
170 | static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate) |
171 | { |
172 | return false; |
173 | } |
174 | |
175 | static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate) |
176 | { |
177 | return false; |
178 | } |
179 | |
180 | static inline void lwtunnel_set_redirect(struct dst_entry *dst) |
181 | { |
182 | } |
183 | |
184 | static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate, |
185 | unsigned int mtu) |
186 | { |
187 | return 0; |
188 | } |
189 | |
190 | static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op, |
191 | unsigned int num) |
192 | { |
193 | return -EOPNOTSUPP; |
194 | |
195 | } |
196 | |
197 | static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op, |
198 | unsigned int num) |
199 | { |
200 | return -EOPNOTSUPP; |
201 | } |
202 | |
203 | static inline int lwtunnel_valid_encap_type(u16 encap_type, |
204 | struct netlink_ext_ack *extack) |
205 | { |
206 | NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel" ); |
207 | return -EOPNOTSUPP; |
208 | } |
209 | static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len, |
210 | struct netlink_ext_ack *extack) |
211 | { |
212 | /* return 0 since we are not walking attr looking for |
213 | * RTA_ENCAP_TYPE attribute on nexthops. |
214 | */ |
215 | return 0; |
216 | } |
217 | |
218 | static inline int lwtunnel_build_state(struct net *net, u16 encap_type, |
219 | struct nlattr *encap, |
220 | unsigned int family, const void *cfg, |
221 | struct lwtunnel_state **lws, |
222 | struct netlink_ext_ack *extack) |
223 | { |
224 | return -EOPNOTSUPP; |
225 | } |
226 | |
227 | static inline int lwtunnel_fill_encap(struct sk_buff *skb, |
228 | struct lwtunnel_state *lwtstate, |
229 | int encap_attr, int encap_type_attr) |
230 | { |
231 | return 0; |
232 | } |
233 | |
234 | static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate) |
235 | { |
236 | return 0; |
237 | } |
238 | |
239 | static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len) |
240 | { |
241 | return NULL; |
242 | } |
243 | |
244 | static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a, |
245 | struct lwtunnel_state *b) |
246 | { |
247 | return 0; |
248 | } |
249 | |
250 | static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
251 | { |
252 | return -EOPNOTSUPP; |
253 | } |
254 | |
255 | static inline int lwtunnel_input(struct sk_buff *skb) |
256 | { |
257 | return -EOPNOTSUPP; |
258 | } |
259 | |
260 | static inline int lwtunnel_xmit(struct sk_buff *skb) |
261 | { |
262 | return -EOPNOTSUPP; |
263 | } |
264 | |
265 | #endif /* CONFIG_LWTUNNEL */ |
266 | |
267 | #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type)) |
268 | |
269 | #endif /* __NET_LWTUNNEL_H */ |
270 | |