1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef __LINUX_NETFILTER_H |
3 | #define __LINUX_NETFILTER_H |
4 | |
5 | #include <linux/init.h> |
6 | #include <linux/skbuff.h> |
7 | #include <linux/net.h> |
8 | #include <linux/if.h> |
9 | #include <linux/in.h> |
10 | #include <linux/in6.h> |
11 | #include <linux/wait.h> |
12 | #include <linux/list.h> |
13 | #include <linux/static_key.h> |
14 | #include <linux/netfilter_defs.h> |
15 | #include <linux/netdevice.h> |
16 | #include <net/net_namespace.h> |
17 | |
18 | #ifdef CONFIG_NETFILTER |
19 | static inline int NF_DROP_GETERR(int verdict) |
20 | { |
21 | return -(verdict >> NF_VERDICT_QBITS); |
22 | } |
23 | |
24 | static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1, |
25 | const union nf_inet_addr *a2) |
26 | { |
27 | return a1->all[0] == a2->all[0] && |
28 | a1->all[1] == a2->all[1] && |
29 | a1->all[2] == a2->all[2] && |
30 | a1->all[3] == a2->all[3]; |
31 | } |
32 | |
33 | static inline void nf_inet_addr_mask(const union nf_inet_addr *a1, |
34 | union nf_inet_addr *result, |
35 | const union nf_inet_addr *mask) |
36 | { |
37 | result->all[0] = a1->all[0] & mask->all[0]; |
38 | result->all[1] = a1->all[1] & mask->all[1]; |
39 | result->all[2] = a1->all[2] & mask->all[2]; |
40 | result->all[3] = a1->all[3] & mask->all[3]; |
41 | } |
42 | |
43 | int netfilter_init(void); |
44 | |
45 | struct sk_buff; |
46 | |
47 | struct nf_hook_ops; |
48 | |
49 | struct sock; |
50 | |
51 | struct nf_hook_state { |
52 | unsigned int hook; |
53 | u_int8_t pf; |
54 | struct net_device *in; |
55 | struct net_device *out; |
56 | struct sock *sk; |
57 | struct net *net; |
58 | int (*okfn)(struct net *, struct sock *, struct sk_buff *); |
59 | }; |
60 | |
61 | typedef unsigned int nf_hookfn(void *priv, |
62 | struct sk_buff *skb, |
63 | const struct nf_hook_state *state); |
64 | struct nf_hook_ops { |
65 | /* User fills in from here down. */ |
66 | nf_hookfn *hook; |
67 | struct net_device *dev; |
68 | void *priv; |
69 | u_int8_t pf; |
70 | unsigned int hooknum; |
71 | /* Hooks are ordered in ascending priority. */ |
72 | int priority; |
73 | }; |
74 | |
75 | struct nf_hook_entry { |
76 | nf_hookfn *hook; |
77 | void *priv; |
78 | }; |
79 | |
80 | struct nf_hook_entries_rcu_head { |
81 | struct rcu_head head; |
82 | void *allocation; |
83 | }; |
84 | |
85 | struct nf_hook_entries { |
86 | u16 num_hook_entries; |
87 | /* padding */ |
88 | struct nf_hook_entry hooks[]; |
89 | |
90 | /* trailer: pointers to original orig_ops of each hook, |
91 | * followed by rcu_head and scratch space used for freeing |
92 | * the structure via call_rcu. |
93 | * |
94 | * This is not part of struct nf_hook_entry since its only |
95 | * needed in slow path (hook register/unregister): |
96 | * const struct nf_hook_ops *orig_ops[] |
97 | * |
98 | * For the same reason, we store this at end -- its |
99 | * only needed when a hook is deleted, not during |
100 | * packet path processing: |
101 | * struct nf_hook_entries_rcu_head head |
102 | */ |
103 | }; |
104 | |
105 | static inline struct nf_hook_ops **nf_hook_entries_get_hook_ops(const struct nf_hook_entries *e) |
106 | { |
107 | unsigned int n = e->num_hook_entries; |
108 | const void *hook_end; |
109 | |
110 | hook_end = &e->hooks[n]; /* this is *past* ->hooks[]! */ |
111 | |
112 | return (struct nf_hook_ops **)hook_end; |
113 | } |
114 | |
115 | static inline int |
116 | nf_hook_entry_hookfn(const struct nf_hook_entry *entry, struct sk_buff *skb, |
117 | struct nf_hook_state *state) |
118 | { |
119 | return entry->hook(entry->priv, skb, state); |
120 | } |
121 | |
122 | static inline void nf_hook_state_init(struct nf_hook_state *p, |
123 | unsigned int hook, |
124 | u_int8_t pf, |
125 | struct net_device *indev, |
126 | struct net_device *outdev, |
127 | struct sock *sk, |
128 | struct net *net, |
129 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
130 | { |
131 | p->hook = hook; |
132 | p->pf = pf; |
133 | p->in = indev; |
134 | p->out = outdev; |
135 | p->sk = sk; |
136 | p->net = net; |
137 | p->okfn = okfn; |
138 | } |
139 | |
140 | |
141 | |
142 | struct nf_sockopt_ops { |
143 | struct list_head list; |
144 | |
145 | u_int8_t pf; |
146 | |
147 | /* Non-inclusive ranges: use 0/0/NULL to never get called. */ |
148 | int set_optmin; |
149 | int set_optmax; |
150 | int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len); |
151 | #ifdef CONFIG_COMPAT |
152 | int (*compat_set)(struct sock *sk, int optval, |
153 | void __user *user, unsigned int len); |
154 | #endif |
155 | int get_optmin; |
156 | int get_optmax; |
157 | int (*get)(struct sock *sk, int optval, void __user *user, int *len); |
158 | #ifdef CONFIG_COMPAT |
159 | int (*compat_get)(struct sock *sk, int optval, |
160 | void __user *user, int *len); |
161 | #endif |
162 | /* Use the module struct to lock set/get code in place */ |
163 | struct module *owner; |
164 | }; |
165 | |
166 | /* Function to register/unregister hook points. */ |
167 | int nf_register_net_hook(struct net *net, const struct nf_hook_ops *ops); |
168 | void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *ops); |
169 | int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg, |
170 | unsigned int n); |
171 | void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg, |
172 | unsigned int n); |
173 | |
174 | /* Functions to register get/setsockopt ranges (non-inclusive). You |
175 | need to check permissions yourself! */ |
176 | int nf_register_sockopt(struct nf_sockopt_ops *reg); |
177 | void nf_unregister_sockopt(struct nf_sockopt_ops *reg); |
178 | |
179 | #ifdef CONFIG_JUMP_LABEL |
180 | extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; |
181 | #endif |
182 | |
183 | int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state, |
184 | const struct nf_hook_entries *e, unsigned int i); |
185 | |
186 | /** |
187 | * nf_hook - call a netfilter hook |
188 | * |
189 | * Returns 1 if the hook has allowed the packet to pass. The function |
190 | * okfn must be invoked by the caller in this case. Any other return |
191 | * value indicates the packet has been consumed by the hook. |
192 | */ |
193 | static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, |
194 | struct sock *sk, struct sk_buff *skb, |
195 | struct net_device *indev, struct net_device *outdev, |
196 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
197 | { |
198 | struct nf_hook_entries *hook_head = NULL; |
199 | int ret = 1; |
200 | |
201 | #ifdef CONFIG_JUMP_LABEL |
202 | if (__builtin_constant_p(pf) && |
203 | __builtin_constant_p(hook) && |
204 | !static_key_false(&nf_hooks_needed[pf][hook])) |
205 | return 1; |
206 | #endif |
207 | |
208 | rcu_read_lock(); |
209 | switch (pf) { |
210 | case NFPROTO_IPV4: |
211 | hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]); |
212 | break; |
213 | case NFPROTO_IPV6: |
214 | hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]); |
215 | break; |
216 | case NFPROTO_ARP: |
217 | #ifdef CONFIG_NETFILTER_FAMILY_ARP |
218 | if (WARN_ON_ONCE(hook >= ARRAY_SIZE(net->nf.hooks_arp))) |
219 | break; |
220 | hook_head = rcu_dereference(net->nf.hooks_arp[hook]); |
221 | #endif |
222 | break; |
223 | case NFPROTO_BRIDGE: |
224 | #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE |
225 | hook_head = rcu_dereference(net->nf.hooks_bridge[hook]); |
226 | #endif |
227 | break; |
228 | #if IS_ENABLED(CONFIG_DECNET) |
229 | case NFPROTO_DECNET: |
230 | hook_head = rcu_dereference(net->nf.hooks_decnet[hook]); |
231 | break; |
232 | #endif |
233 | default: |
234 | WARN_ON_ONCE(1); |
235 | break; |
236 | } |
237 | |
238 | if (hook_head) { |
239 | struct nf_hook_state state; |
240 | |
241 | nf_hook_state_init(&state, hook, pf, indev, outdev, |
242 | sk, net, okfn); |
243 | |
244 | ret = nf_hook_slow(skb, &state, hook_head, 0); |
245 | } |
246 | rcu_read_unlock(); |
247 | |
248 | return ret; |
249 | } |
250 | |
251 | /* Activate hook; either okfn or kfree_skb called, unless a hook |
252 | returns NF_STOLEN (in which case, it's up to the hook to deal with |
253 | the consequences). |
254 | |
255 | Returns -ERRNO if packet dropped. Zero means queued, stolen or |
256 | accepted. |
257 | */ |
258 | |
259 | /* RR: |
260 | > I don't want nf_hook to return anything because people might forget |
261 | > about async and trust the return value to mean "packet was ok". |
262 | |
263 | AK: |
264 | Just document it clearly, then you can expect some sense from kernel |
265 | coders :) |
266 | */ |
267 | |
268 | static inline int |
269 | NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, |
270 | struct sk_buff *skb, struct net_device *in, struct net_device *out, |
271 | int (*okfn)(struct net *, struct sock *, struct sk_buff *), |
272 | bool cond) |
273 | { |
274 | int ret; |
275 | |
276 | if (!cond || |
277 | ((ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn)) == 1)) |
278 | ret = okfn(net, sk, skb); |
279 | return ret; |
280 | } |
281 | |
282 | static inline int |
283 | NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct sk_buff *skb, |
284 | struct net_device *in, struct net_device *out, |
285 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
286 | { |
287 | int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn); |
288 | if (ret == 1) |
289 | ret = okfn(net, sk, skb); |
290 | return ret; |
291 | } |
292 | |
293 | static inline void |
294 | NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, |
295 | struct list_head *head, struct net_device *in, struct net_device *out, |
296 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
297 | { |
298 | struct sk_buff *skb, *next; |
299 | struct list_head sublist; |
300 | |
301 | INIT_LIST_HEAD(&sublist); |
302 | list_for_each_entry_safe(skb, next, head, list) { |
303 | list_del(&skb->list); |
304 | if (nf_hook(pf, hook, net, sk, skb, in, out, okfn) == 1) |
305 | list_add_tail(&skb->list, &sublist); |
306 | } |
307 | /* Put passed packets back on main list */ |
308 | list_splice(&sublist, head); |
309 | } |
310 | |
311 | /* Call setsockopt() */ |
312 | int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt, |
313 | unsigned int len); |
314 | int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt, |
315 | int *len); |
316 | #ifdef CONFIG_COMPAT |
317 | int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, |
318 | char __user *opt, unsigned int len); |
319 | int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, |
320 | char __user *opt, int *len); |
321 | #endif |
322 | |
323 | /* Call this before modifying an existing packet: ensures it is |
324 | modifiable and linear to the point you care about (writable_len). |
325 | Returns true or false. */ |
326 | int skb_make_writable(struct sk_buff *skb, unsigned int writable_len); |
327 | |
328 | struct flowi; |
329 | struct nf_queue_entry; |
330 | |
331 | __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook, |
332 | unsigned int dataoff, u_int8_t protocol, |
333 | unsigned short family); |
334 | |
335 | __sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook, |
336 | unsigned int dataoff, unsigned int len, |
337 | u_int8_t protocol, unsigned short family); |
338 | int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl, |
339 | bool strict, unsigned short family); |
340 | int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry); |
341 | |
342 | #include <net/flow.h> |
343 | |
344 | struct nf_conn; |
345 | enum nf_nat_manip_type; |
346 | struct nlattr; |
347 | enum ip_conntrack_dir; |
348 | |
349 | struct nf_nat_hook { |
350 | int (*parse_nat_setup)(struct nf_conn *ct, enum nf_nat_manip_type manip, |
351 | const struct nlattr *attr); |
352 | void (*decode_session)(struct sk_buff *skb, struct flowi *fl); |
353 | unsigned int (*manip_pkt)(struct sk_buff *skb, struct nf_conn *ct, |
354 | enum nf_nat_manip_type mtype, |
355 | enum ip_conntrack_dir dir); |
356 | }; |
357 | |
358 | extern struct nf_nat_hook __rcu *nf_nat_hook; |
359 | |
360 | static inline void |
361 | nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) |
362 | { |
363 | #ifdef CONFIG_NF_NAT_NEEDED |
364 | struct nf_nat_hook *nat_hook; |
365 | |
366 | rcu_read_lock(); |
367 | nat_hook = rcu_dereference(nf_nat_hook); |
368 | if (nat_hook && nat_hook->decode_session) |
369 | nat_hook->decode_session(skb, fl); |
370 | rcu_read_unlock(); |
371 | #endif |
372 | } |
373 | |
374 | #else /* !CONFIG_NETFILTER */ |
375 | static inline int |
376 | NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, |
377 | struct sk_buff *skb, struct net_device *in, struct net_device *out, |
378 | int (*okfn)(struct net *, struct sock *, struct sk_buff *), |
379 | bool cond) |
380 | { |
381 | return okfn(net, sk, skb); |
382 | } |
383 | |
384 | static inline int |
385 | NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, |
386 | struct sk_buff *skb, struct net_device *in, struct net_device *out, |
387 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
388 | { |
389 | return okfn(net, sk, skb); |
390 | } |
391 | |
392 | static inline void |
393 | NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, |
394 | struct list_head *head, struct net_device *in, struct net_device *out, |
395 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
396 | { |
397 | /* nothing to do */ |
398 | } |
399 | |
400 | static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, |
401 | struct sock *sk, struct sk_buff *skb, |
402 | struct net_device *indev, struct net_device *outdev, |
403 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
404 | { |
405 | return 1; |
406 | } |
407 | struct flowi; |
408 | static inline void |
409 | nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) |
410 | { |
411 | } |
412 | #endif /*CONFIG_NETFILTER*/ |
413 | |
414 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
415 | #include <linux/netfilter/nf_conntrack_zones_common.h> |
416 | |
417 | extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu; |
418 | void nf_ct_attach(struct sk_buff *, const struct sk_buff *); |
419 | struct nf_conntrack_tuple; |
420 | bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple, |
421 | const struct sk_buff *skb); |
422 | #else |
423 | static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} |
424 | struct nf_conntrack_tuple; |
425 | static inline bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple, |
426 | const struct sk_buff *skb) |
427 | { |
428 | return false; |
429 | } |
430 | #endif |
431 | |
432 | struct nf_conn; |
433 | enum ip_conntrack_info; |
434 | |
435 | struct nf_ct_hook { |
436 | int (*update)(struct net *net, struct sk_buff *skb); |
437 | void (*destroy)(struct nf_conntrack *); |
438 | bool (*get_tuple_skb)(struct nf_conntrack_tuple *, |
439 | const struct sk_buff *); |
440 | }; |
441 | extern struct nf_ct_hook __rcu *nf_ct_hook; |
442 | |
443 | struct nlattr; |
444 | |
445 | struct nfnl_ct_hook { |
446 | struct nf_conn *(*get_ct)(const struct sk_buff *skb, |
447 | enum ip_conntrack_info *ctinfo); |
448 | size_t (*build_size)(const struct nf_conn *ct); |
449 | int (*build)(struct sk_buff *skb, struct nf_conn *ct, |
450 | enum ip_conntrack_info ctinfo, |
451 | u_int16_t ct_attr, u_int16_t ct_info_attr); |
452 | int (*parse)(const struct nlattr *attr, struct nf_conn *ct); |
453 | int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct, |
454 | u32 portid, u32 report); |
455 | void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct, |
456 | enum ip_conntrack_info ctinfo, s32 off); |
457 | }; |
458 | extern struct nfnl_ct_hook __rcu *nfnl_ct_hook; |
459 | |
460 | /** |
461 | * nf_skb_duplicated - TEE target has sent a packet |
462 | * |
463 | * When a xtables target sends a packet, the OUTPUT and POSTROUTING |
464 | * hooks are traversed again, i.e. nft and xtables are invoked recursively. |
465 | * |
466 | * This is used by xtables TEE target to prevent the duplicated skb from |
467 | * being duplicated again. |
468 | */ |
469 | DECLARE_PER_CPU(bool, nf_skb_duplicated); |
470 | |
471 | #endif /*__LINUX_NETFILTER_H*/ |
472 | |