1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_NETFILTER_H
3 #define __LINUX_NETFILTER_H
5 #include <linux/init.h>
6 #include <linux/skbuff.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 <linux/sockptr.h>
17 #include <net/net_namespace.h>
19 static inline int NF_DROP_GETERR(int verdict)
21 return -(verdict >> NF_VERDICT_QBITS);
24 static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1,
25 const union nf_inet_addr *a2)
27 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
28 const unsigned long *ul1 = (const unsigned long *)a1;
29 const unsigned long *ul2 = (const unsigned long *)a2;
31 return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
33 return a1->all[0] == a2->all[0] &&
34 a1->all[1] == a2->all[1] &&
35 a1->all[2] == a2->all[2] &&
36 a1->all[3] == a2->all[3];
40 static inline void nf_inet_addr_mask(const union nf_inet_addr *a1,
41 union nf_inet_addr *result,
42 const union nf_inet_addr *mask)
44 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
45 const unsigned long *ua = (const unsigned long *)a1;
46 unsigned long *ur = (unsigned long *)result;
47 const unsigned long *um = (const unsigned long *)mask;
49 ur[0] = ua[0] & um[0];
50 ur[1] = ua[1] & um[1];
52 result->all[0] = a1->all[0] & mask->all[0];
53 result->all[1] = a1->all[1] & mask->all[1];
54 result->all[2] = a1->all[2] & mask->all[2];
55 result->all[3] = a1->all[3] & mask->all[3];
59 int netfilter_init(void);
67 struct nf_hook_state {
70 struct net_device *in;
71 struct net_device *out;
74 int (*okfn)(struct net *, struct sock *, struct sk_buff *);
77 typedef unsigned int nf_hookfn(void *priv,
79 const struct nf_hook_state *state);
81 /* User fills in from here down. */
83 struct net_device *dev;
87 /* Hooks are ordered in ascending priority. */
91 struct nf_hook_entry {
96 struct nf_hook_entries_rcu_head {
101 struct nf_hook_entries {
102 u16 num_hook_entries;
104 struct nf_hook_entry hooks[];
106 /* trailer: pointers to original orig_ops of each hook,
107 * followed by rcu_head and scratch space used for freeing
108 * the structure via call_rcu.
110 * This is not part of struct nf_hook_entry since its only
111 * needed in slow path (hook register/unregister):
112 * const struct nf_hook_ops *orig_ops[]
114 * For the same reason, we store this at end -- its
115 * only needed when a hook is deleted, not during
116 * packet path processing:
117 * struct nf_hook_entries_rcu_head head
121 #ifdef CONFIG_NETFILTER
122 static inline struct nf_hook_ops **nf_hook_entries_get_hook_ops(const struct nf_hook_entries *e)
124 unsigned int n = e->num_hook_entries;
125 const void *hook_end;
127 hook_end = &e->hooks[n]; /* this is *past* ->hooks[]! */
129 return (struct nf_hook_ops **)hook_end;
133 nf_hook_entry_hookfn(const struct nf_hook_entry *entry, struct sk_buff *skb,
134 struct nf_hook_state *state)
136 return entry->hook(entry->priv, skb, state);
139 static inline void nf_hook_state_init(struct nf_hook_state *p,
142 struct net_device *indev,
143 struct net_device *outdev,
146 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
159 struct nf_sockopt_ops {
160 struct list_head list;
164 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
167 int (*set)(struct sock *sk, int optval, sockptr_t arg,
171 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
172 /* Use the module struct to lock set/get code in place */
173 struct module *owner;
176 /* Function to register/unregister hook points. */
177 int nf_register_net_hook(struct net *net, const struct nf_hook_ops *ops);
178 void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *ops);
179 int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg,
181 void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg,
184 /* Functions to register get/setsockopt ranges (non-inclusive). You
185 need to check permissions yourself! */
186 int nf_register_sockopt(struct nf_sockopt_ops *reg);
187 void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
189 #ifdef CONFIG_JUMP_LABEL
190 extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
193 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state,
194 const struct nf_hook_entries *e, unsigned int i);
196 void nf_hook_slow_list(struct list_head *head, struct nf_hook_state *state,
197 const struct nf_hook_entries *e);
199 * nf_hook - call a netfilter hook
201 * Returns 1 if the hook has allowed the packet to pass. The function
202 * okfn must be invoked by the caller in this case. Any other return
203 * value indicates the packet has been consumed by the hook.
205 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
206 struct sock *sk, struct sk_buff *skb,
207 struct net_device *indev, struct net_device *outdev,
208 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
210 struct nf_hook_entries *hook_head = NULL;
213 #ifdef CONFIG_JUMP_LABEL
214 if (__builtin_constant_p(pf) &&
215 __builtin_constant_p(hook) &&
216 !static_key_false(&nf_hooks_needed[pf][hook]))
223 hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
226 hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
229 #ifdef CONFIG_NETFILTER_FAMILY_ARP
230 if (WARN_ON_ONCE(hook >= ARRAY_SIZE(net->nf.hooks_arp)))
232 hook_head = rcu_dereference(net->nf.hooks_arp[hook]);
236 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
237 hook_head = rcu_dereference(net->nf.hooks_bridge[hook]);
240 #if IS_ENABLED(CONFIG_DECNET)
242 hook_head = rcu_dereference(net->nf.hooks_decnet[hook]);
251 struct nf_hook_state state;
253 nf_hook_state_init(&state, hook, pf, indev, outdev,
256 ret = nf_hook_slow(skb, &state, hook_head, 0);
263 /* Activate hook; either okfn or kfree_skb called, unless a hook
264 returns NF_STOLEN (in which case, it's up to the hook to deal with
267 Returns -ERRNO if packet dropped. Zero means queued, stolen or
272 > I don't want nf_hook to return anything because people might forget
273 > about async and trust the return value to mean "packet was ok".
276 Just document it clearly, then you can expect some sense from kernel
281 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
282 struct sk_buff *skb, struct net_device *in, struct net_device *out,
283 int (*okfn)(struct net *, struct sock *, struct sk_buff *),
289 ((ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn)) == 1))
290 ret = okfn(net, sk, skb);
295 NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct sk_buff *skb,
296 struct net_device *in, struct net_device *out,
297 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
299 int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn);
301 ret = okfn(net, sk, skb);
306 NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
307 struct list_head *head, struct net_device *in, struct net_device *out,
308 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
310 struct nf_hook_entries *hook_head = NULL;
312 #ifdef CONFIG_JUMP_LABEL
313 if (__builtin_constant_p(pf) &&
314 __builtin_constant_p(hook) &&
315 !static_key_false(&nf_hooks_needed[pf][hook]))
322 hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
325 hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
333 struct nf_hook_state state;
335 nf_hook_state_init(&state, hook, pf, in, out, sk, net, okfn);
337 nf_hook_slow_list(head, &state, hook_head);
342 /* Call setsockopt() */
343 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, sockptr_t opt,
345 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
349 struct nf_queue_entry;
351 __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,
352 unsigned int dataoff, u_int8_t protocol,
353 unsigned short family);
355 __sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
356 unsigned int dataoff, unsigned int len,
357 u_int8_t protocol, unsigned short family);
358 int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
359 bool strict, unsigned short family);
360 int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry);
362 #include <net/flow.h>
365 enum nf_nat_manip_type;
367 enum ip_conntrack_dir;
370 int (*parse_nat_setup)(struct nf_conn *ct, enum nf_nat_manip_type manip,
371 const struct nlattr *attr);
372 void (*decode_session)(struct sk_buff *skb, struct flowi *fl);
373 unsigned int (*manip_pkt)(struct sk_buff *skb, struct nf_conn *ct,
374 enum nf_nat_manip_type mtype,
375 enum ip_conntrack_dir dir);
378 extern struct nf_nat_hook __rcu *nf_nat_hook;
381 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
383 #if IS_ENABLED(CONFIG_NF_NAT)
384 struct nf_nat_hook *nat_hook;
387 nat_hook = rcu_dereference(nf_nat_hook);
388 if (nat_hook && nat_hook->decode_session)
389 nat_hook->decode_session(skb, fl);
394 #else /* !CONFIG_NETFILTER */
396 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
397 struct sk_buff *skb, struct net_device *in, struct net_device *out,
398 int (*okfn)(struct net *, struct sock *, struct sk_buff *),
401 return okfn(net, sk, skb);
405 NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
406 struct sk_buff *skb, struct net_device *in, struct net_device *out,
407 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
409 return okfn(net, sk, skb);
413 NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
414 struct list_head *head, struct net_device *in, struct net_device *out,
415 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
420 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
421 struct sock *sk, struct sk_buff *skb,
422 struct net_device *indev, struct net_device *outdev,
423 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
429 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
432 #endif /*CONFIG_NETFILTER*/
434 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
435 #include <linux/netfilter/nf_conntrack_zones_common.h>
437 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
438 void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
439 struct nf_conntrack_tuple;
440 bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
441 const struct sk_buff *skb);
443 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
444 struct nf_conntrack_tuple;
445 static inline bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
446 const struct sk_buff *skb)
453 enum ip_conntrack_info;
456 int (*update)(struct net *net, struct sk_buff *skb);
457 void (*destroy)(struct nf_conntrack *);
458 bool (*get_tuple_skb)(struct nf_conntrack_tuple *,
459 const struct sk_buff *);
461 extern struct nf_ct_hook __rcu *nf_ct_hook;
465 struct nfnl_ct_hook {
466 struct nf_conn *(*get_ct)(const struct sk_buff *skb,
467 enum ip_conntrack_info *ctinfo);
468 size_t (*build_size)(const struct nf_conn *ct);
469 int (*build)(struct sk_buff *skb, struct nf_conn *ct,
470 enum ip_conntrack_info ctinfo,
471 u_int16_t ct_attr, u_int16_t ct_info_attr);
472 int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
473 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
474 u32 portid, u32 report);
475 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
476 enum ip_conntrack_info ctinfo, s32 off);
478 extern struct nfnl_ct_hook __rcu *nfnl_ct_hook;
481 * nf_skb_duplicated - TEE target has sent a packet
483 * When a xtables target sends a packet, the OUTPUT and POSTROUTING
484 * hooks are traversed again, i.e. nft and xtables are invoked recursively.
486 * This is used by xtables TEE target to prevent the duplicated skb from
487 * being duplicated again.
489 DECLARE_PER_CPU(bool, nf_skb_duplicated);
491 #endif /*__LINUX_NETFILTER_H*/