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/module.h> |
15 | #include <linux/netfilter_defs.h> |
16 | #include <linux/netdevice.h> |
17 | #include <linux/sockptr.h> |
18 | #include <net/net_namespace.h> |
19 | |
20 | static inline int NF_DROP_GETERR(int verdict) |
21 | { |
22 | return -(verdict >> NF_VERDICT_QBITS); |
23 | } |
24 | |
25 | static __always_inline int |
26 | NF_DROP_REASON(struct sk_buff *skb, enum skb_drop_reason reason, u32 err) |
27 | { |
28 | BUILD_BUG_ON(err > 0xffff); |
29 | |
30 | kfree_skb_reason(skb, reason); |
31 | |
32 | return ((err << 16) | NF_STOLEN); |
33 | } |
34 | |
35 | static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1, |
36 | const union nf_inet_addr *a2) |
37 | { |
38 | #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 |
39 | const unsigned long *ul1 = (const unsigned long *)a1; |
40 | const unsigned long *ul2 = (const unsigned long *)a2; |
41 | |
42 | return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL; |
43 | #else |
44 | return a1->all[0] == a2->all[0] && |
45 | a1->all[1] == a2->all[1] && |
46 | a1->all[2] == a2->all[2] && |
47 | a1->all[3] == a2->all[3]; |
48 | #endif |
49 | } |
50 | |
51 | static inline void nf_inet_addr_mask(const union nf_inet_addr *a1, |
52 | union nf_inet_addr *result, |
53 | const union nf_inet_addr *mask) |
54 | { |
55 | #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 |
56 | const unsigned long *ua = (const unsigned long *)a1; |
57 | unsigned long *ur = (unsigned long *)result; |
58 | const unsigned long *um = (const unsigned long *)mask; |
59 | |
60 | ur[0] = ua[0] & um[0]; |
61 | ur[1] = ua[1] & um[1]; |
62 | #else |
63 | result->all[0] = a1->all[0] & mask->all[0]; |
64 | result->all[1] = a1->all[1] & mask->all[1]; |
65 | result->all[2] = a1->all[2] & mask->all[2]; |
66 | result->all[3] = a1->all[3] & mask->all[3]; |
67 | #endif |
68 | } |
69 | |
70 | int netfilter_init(void); |
71 | |
72 | struct sk_buff; |
73 | |
74 | struct nf_hook_ops; |
75 | |
76 | struct sock; |
77 | |
78 | struct nf_hook_state { |
79 | u8 hook; |
80 | u8 pf; |
81 | struct net_device *in; |
82 | struct net_device *out; |
83 | struct sock *sk; |
84 | struct net *net; |
85 | int (*okfn)(struct net *, struct sock *, struct sk_buff *); |
86 | }; |
87 | |
88 | typedef unsigned int nf_hookfn(void *priv, |
89 | struct sk_buff *skb, |
90 | const struct nf_hook_state *state); |
91 | enum nf_hook_ops_type { |
92 | NF_HOOK_OP_UNDEFINED, |
93 | NF_HOOK_OP_NF_TABLES, |
94 | NF_HOOK_OP_BPF, |
95 | }; |
96 | |
97 | struct nf_hook_ops { |
98 | struct list_head list; |
99 | struct rcu_head rcu; |
100 | |
101 | /* User fills in from here down. */ |
102 | nf_hookfn *hook; |
103 | struct net_device *dev; |
104 | void *priv; |
105 | u8 pf; |
106 | enum nf_hook_ops_type hook_ops_type:8; |
107 | unsigned int hooknum; |
108 | /* Hooks are ordered in ascending priority. */ |
109 | int priority; |
110 | }; |
111 | |
112 | struct nf_hook_entry { |
113 | nf_hookfn *hook; |
114 | void *priv; |
115 | }; |
116 | |
117 | struct nf_hook_entries_rcu_head { |
118 | struct rcu_head head; |
119 | void *allocation; |
120 | }; |
121 | |
122 | struct nf_hook_entries { |
123 | u16 num_hook_entries; |
124 | /* padding */ |
125 | struct nf_hook_entry hooks[]; |
126 | |
127 | /* trailer: pointers to original orig_ops of each hook, |
128 | * followed by rcu_head and scratch space used for freeing |
129 | * the structure via call_rcu. |
130 | * |
131 | * This is not part of struct nf_hook_entry since its only |
132 | * needed in slow path (hook register/unregister): |
133 | * const struct nf_hook_ops *orig_ops[] |
134 | * |
135 | * For the same reason, we store this at end -- its |
136 | * only needed when a hook is deleted, not during |
137 | * packet path processing: |
138 | * struct nf_hook_entries_rcu_head head |
139 | */ |
140 | }; |
141 | |
142 | #ifdef CONFIG_NETFILTER |
143 | static inline struct nf_hook_ops **nf_hook_entries_get_hook_ops(const struct nf_hook_entries *e) |
144 | { |
145 | unsigned int n = e->num_hook_entries; |
146 | const void *hook_end; |
147 | |
148 | hook_end = &e->hooks[n]; /* this is *past* ->hooks[]! */ |
149 | |
150 | return (struct nf_hook_ops **)hook_end; |
151 | } |
152 | |
153 | static inline int |
154 | nf_hook_entry_hookfn(const struct nf_hook_entry *entry, struct sk_buff *skb, |
155 | struct nf_hook_state *state) |
156 | { |
157 | return entry->hook(entry->priv, skb, state); |
158 | } |
159 | |
160 | static inline void nf_hook_state_init(struct nf_hook_state *p, |
161 | unsigned int hook, |
162 | u_int8_t pf, |
163 | struct net_device *indev, |
164 | struct net_device *outdev, |
165 | struct sock *sk, |
166 | struct net *net, |
167 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
168 | { |
169 | p->hook = hook; |
170 | p->pf = pf; |
171 | p->in = indev; |
172 | p->out = outdev; |
173 | p->sk = sk; |
174 | p->net = net; |
175 | p->okfn = okfn; |
176 | } |
177 | |
178 | |
179 | |
180 | struct nf_sockopt_ops { |
181 | struct list_head list; |
182 | |
183 | u_int8_t pf; |
184 | |
185 | /* Non-inclusive ranges: use 0/0/NULL to never get called. */ |
186 | int set_optmin; |
187 | int set_optmax; |
188 | int (*set)(struct sock *sk, int optval, sockptr_t arg, |
189 | unsigned int len); |
190 | int get_optmin; |
191 | int get_optmax; |
192 | int (*get)(struct sock *sk, int optval, void __user *user, int *len); |
193 | /* Use the module struct to lock set/get code in place */ |
194 | struct module *owner; |
195 | }; |
196 | |
197 | /* Function to register/unregister hook points. */ |
198 | int nf_register_net_hook(struct net *net, const struct nf_hook_ops *ops); |
199 | void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *ops); |
200 | int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg, |
201 | unsigned int n); |
202 | void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg, |
203 | unsigned int n); |
204 | |
205 | /* Functions to register get/setsockopt ranges (non-inclusive). You |
206 | need to check permissions yourself! */ |
207 | int nf_register_sockopt(struct nf_sockopt_ops *reg); |
208 | void nf_unregister_sockopt(struct nf_sockopt_ops *reg); |
209 | |
210 | #ifdef CONFIG_JUMP_LABEL |
211 | extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; |
212 | #endif |
213 | |
214 | int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state, |
215 | const struct nf_hook_entries *e, unsigned int i); |
216 | |
217 | void nf_hook_slow_list(struct list_head *head, struct nf_hook_state *state, |
218 | const struct nf_hook_entries *e); |
219 | /** |
220 | * nf_hook - call a netfilter hook |
221 | * |
222 | * Returns 1 if the hook has allowed the packet to pass. The function |
223 | * okfn must be invoked by the caller in this case. Any other return |
224 | * value indicates the packet has been consumed by the hook. |
225 | */ |
226 | static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, |
227 | struct sock *sk, struct sk_buff *skb, |
228 | struct net_device *indev, struct net_device *outdev, |
229 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
230 | { |
231 | struct nf_hook_entries *hook_head = NULL; |
232 | int ret = 1; |
233 | |
234 | #ifdef CONFIG_JUMP_LABEL |
235 | if (__builtin_constant_p(pf) && |
236 | __builtin_constant_p(hook) && |
237 | !static_key_false(key: &nf_hooks_needed[pf][hook])) |
238 | return 1; |
239 | #endif |
240 | |
241 | rcu_read_lock(); |
242 | switch (pf) { |
243 | case NFPROTO_IPV4: |
244 | hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]); |
245 | break; |
246 | case NFPROTO_IPV6: |
247 | hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]); |
248 | break; |
249 | case NFPROTO_ARP: |
250 | #ifdef CONFIG_NETFILTER_FAMILY_ARP |
251 | if (WARN_ON_ONCE(hook >= ARRAY_SIZE(net->nf.hooks_arp))) |
252 | break; |
253 | hook_head = rcu_dereference(net->nf.hooks_arp[hook]); |
254 | #endif |
255 | break; |
256 | case NFPROTO_BRIDGE: |
257 | #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE |
258 | hook_head = rcu_dereference(net->nf.hooks_bridge[hook]); |
259 | #endif |
260 | break; |
261 | default: |
262 | WARN_ON_ONCE(1); |
263 | break; |
264 | } |
265 | |
266 | if (hook_head) { |
267 | struct nf_hook_state state; |
268 | |
269 | nf_hook_state_init(p: &state, hook, pf, indev, outdev, |
270 | sk, net, okfn); |
271 | |
272 | ret = nf_hook_slow(skb, state: &state, e: hook_head, i: 0); |
273 | } |
274 | rcu_read_unlock(); |
275 | |
276 | return ret; |
277 | } |
278 | |
279 | /* Activate hook; either okfn or kfree_skb called, unless a hook |
280 | returns NF_STOLEN (in which case, it's up to the hook to deal with |
281 | the consequences). |
282 | |
283 | Returns -ERRNO if packet dropped. Zero means queued, stolen or |
284 | accepted. |
285 | */ |
286 | |
287 | /* RR: |
288 | > I don't want nf_hook to return anything because people might forget |
289 | > about async and trust the return value to mean "packet was ok". |
290 | |
291 | AK: |
292 | Just document it clearly, then you can expect some sense from kernel |
293 | coders :) |
294 | */ |
295 | |
296 | static inline int |
297 | NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, |
298 | struct sk_buff *skb, struct net_device *in, struct net_device *out, |
299 | int (*okfn)(struct net *, struct sock *, struct sk_buff *), |
300 | bool cond) |
301 | { |
302 | int ret; |
303 | |
304 | if (!cond || |
305 | ((ret = nf_hook(pf, hook, net, sk, skb, indev: in, outdev: out, okfn)) == 1)) |
306 | ret = okfn(net, sk, skb); |
307 | return ret; |
308 | } |
309 | |
310 | static inline int |
311 | NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct sk_buff *skb, |
312 | struct net_device *in, struct net_device *out, |
313 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
314 | { |
315 | int ret = nf_hook(pf, hook, net, sk, skb, indev: in, outdev: out, okfn); |
316 | if (ret == 1) |
317 | ret = okfn(net, sk, skb); |
318 | return ret; |
319 | } |
320 | |
321 | static inline void |
322 | NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, |
323 | struct list_head *head, struct net_device *in, struct net_device *out, |
324 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
325 | { |
326 | struct nf_hook_entries *hook_head = NULL; |
327 | |
328 | #ifdef CONFIG_JUMP_LABEL |
329 | if (__builtin_constant_p(pf) && |
330 | __builtin_constant_p(hook) && |
331 | !static_key_false(key: &nf_hooks_needed[pf][hook])) |
332 | return; |
333 | #endif |
334 | |
335 | rcu_read_lock(); |
336 | switch (pf) { |
337 | case NFPROTO_IPV4: |
338 | hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]); |
339 | break; |
340 | case NFPROTO_IPV6: |
341 | hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]); |
342 | break; |
343 | default: |
344 | WARN_ON_ONCE(1); |
345 | break; |
346 | } |
347 | |
348 | if (hook_head) { |
349 | struct nf_hook_state state; |
350 | |
351 | nf_hook_state_init(p: &state, hook, pf, indev: in, outdev: out, sk, net, okfn); |
352 | |
353 | nf_hook_slow_list(head, state: &state, e: hook_head); |
354 | } |
355 | rcu_read_unlock(); |
356 | } |
357 | |
358 | /* Call setsockopt() */ |
359 | int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, sockptr_t opt, |
360 | unsigned int len); |
361 | int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt, |
362 | int *len); |
363 | |
364 | struct flowi; |
365 | struct nf_queue_entry; |
366 | |
367 | __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook, |
368 | unsigned int dataoff, u_int8_t protocol, |
369 | unsigned short family); |
370 | |
371 | __sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook, |
372 | unsigned int dataoff, unsigned int len, |
373 | u_int8_t protocol, unsigned short family); |
374 | int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl, |
375 | bool strict, unsigned short family); |
376 | |
377 | #include <net/flow.h> |
378 | |
379 | struct nf_conn; |
380 | enum nf_nat_manip_type; |
381 | struct nlattr; |
382 | |
383 | struct nf_nat_hook { |
384 | int (*parse_nat_setup)(struct nf_conn *ct, enum nf_nat_manip_type manip, |
385 | const struct nlattr *attr); |
386 | void (*decode_session)(struct sk_buff *skb, struct flowi *fl); |
387 | void (*remove_nat_bysrc)(struct nf_conn *ct); |
388 | }; |
389 | |
390 | extern const struct nf_nat_hook __rcu *nf_nat_hook; |
391 | |
392 | static inline void |
393 | nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) |
394 | { |
395 | #if IS_ENABLED(CONFIG_NF_NAT) |
396 | const struct nf_nat_hook *nat_hook; |
397 | |
398 | rcu_read_lock(); |
399 | nat_hook = rcu_dereference(nf_nat_hook); |
400 | if (nat_hook && nat_hook->decode_session) |
401 | nat_hook->decode_session(skb, fl); |
402 | rcu_read_unlock(); |
403 | #endif |
404 | } |
405 | |
406 | #else /* !CONFIG_NETFILTER */ |
407 | static inline int |
408 | NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, |
409 | struct sk_buff *skb, struct net_device *in, struct net_device *out, |
410 | int (*okfn)(struct net *, struct sock *, struct sk_buff *), |
411 | bool cond) |
412 | { |
413 | return okfn(net, sk, skb); |
414 | } |
415 | |
416 | static inline int |
417 | NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, |
418 | struct sk_buff *skb, struct net_device *in, struct net_device *out, |
419 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
420 | { |
421 | return okfn(net, sk, skb); |
422 | } |
423 | |
424 | static inline void |
425 | NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, |
426 | struct list_head *head, struct net_device *in, struct net_device *out, |
427 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
428 | { |
429 | /* nothing to do */ |
430 | } |
431 | |
432 | static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, |
433 | struct sock *sk, struct sk_buff *skb, |
434 | struct net_device *indev, struct net_device *outdev, |
435 | int (*okfn)(struct net *, struct sock *, struct sk_buff *)) |
436 | { |
437 | return 1; |
438 | } |
439 | struct flowi; |
440 | static inline void |
441 | nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) |
442 | { |
443 | } |
444 | #endif /*CONFIG_NETFILTER*/ |
445 | |
446 | #if IS_ENABLED(CONFIG_NF_CONNTRACK) |
447 | #include <linux/netfilter/nf_conntrack_zones_common.h> |
448 | |
449 | void nf_ct_attach(struct sk_buff *, const struct sk_buff *); |
450 | void nf_ct_set_closing(struct nf_conntrack *nfct); |
451 | struct nf_conntrack_tuple; |
452 | bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple, |
453 | const struct sk_buff *skb); |
454 | #else |
455 | static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} |
456 | static inline void nf_ct_set_closing(struct nf_conntrack *nfct) {} |
457 | struct nf_conntrack_tuple; |
458 | static inline bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple, |
459 | const struct sk_buff *skb) |
460 | { |
461 | return false; |
462 | } |
463 | #endif |
464 | |
465 | struct nf_conn; |
466 | enum ip_conntrack_info; |
467 | |
468 | struct nf_ct_hook { |
469 | int (*update)(struct net *net, struct sk_buff *skb); |
470 | void (*destroy)(struct nf_conntrack *); |
471 | bool (*get_tuple_skb)(struct nf_conntrack_tuple *, |
472 | const struct sk_buff *); |
473 | void (*attach)(struct sk_buff *nskb, const struct sk_buff *skb); |
474 | void (*set_closing)(struct nf_conntrack *nfct); |
475 | int (*confirm)(struct sk_buff *skb); |
476 | u32 (*get_id)(const struct nf_conntrack *nfct); |
477 | }; |
478 | extern const struct nf_ct_hook __rcu *nf_ct_hook; |
479 | |
480 | struct nlattr; |
481 | |
482 | struct nfnl_ct_hook { |
483 | size_t (*build_size)(const struct nf_conn *ct); |
484 | int (*build)(struct sk_buff *skb, struct nf_conn *ct, |
485 | enum ip_conntrack_info ctinfo, |
486 | u_int16_t ct_attr, u_int16_t ct_info_attr); |
487 | int (*parse)(const struct nlattr *attr, struct nf_conn *ct); |
488 | int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct, |
489 | u32 portid, u32 report); |
490 | void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct, |
491 | enum ip_conntrack_info ctinfo, s32 off); |
492 | }; |
493 | extern const struct nfnl_ct_hook __rcu *nfnl_ct_hook; |
494 | |
495 | struct nf_defrag_hook { |
496 | struct module *owner; |
497 | int (*enable)(struct net *net); |
498 | void (*disable)(struct net *net); |
499 | }; |
500 | |
501 | extern const struct nf_defrag_hook __rcu *nf_defrag_v4_hook; |
502 | extern const struct nf_defrag_hook __rcu *nf_defrag_v6_hook; |
503 | |
504 | /* |
505 | * Contains bitmask of ctnetlink event subscribers, if any. |
506 | * Can't be pernet due to NETLINK_LISTEN_ALL_NSID setsockopt flag. |
507 | */ |
508 | extern u8 nf_ctnetlink_has_listener; |
509 | #endif /*__LINUX_NETFILTER_H*/ |
510 |
Definitions
- NF_DROP_GETERR
- NF_DROP_REASON
- nf_inet_addr_cmp
- nf_inet_addr_mask
- nf_hook_state
- nf_hook_ops_type
- nf_hook_ops
- nf_hook_entry
- nf_hook_entries_rcu_head
- nf_hook_entries
- nf_hook_entries_get_hook_ops
- nf_hook_entry_hookfn
- nf_hook_state_init
- nf_sockopt_ops
- nf_hook
- NF_HOOK_COND
- NF_HOOK
- NF_HOOK_LIST
- nf_nat_hook
- nf_nat_decode_session
- nf_ct_hook
- nfnl_ct_hook
Improve your Profiling and Debugging skills
Find out more