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 <net/net_namespace.h>
18 #ifdef CONFIG_NETFILTER
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 static inline struct nf_hook_ops **nf_hook_entries_get_hook_ops(const struct nf_hook_entries *e)
123 unsigned int n = e->num_hook_entries;
124 const void *hook_end;
126 hook_end = &e->hooks[n]; /* this is *past* ->hooks[]! */
128 return (struct nf_hook_ops **)hook_end;
132 nf_hook_entry_hookfn(const struct nf_hook_entry *entry, struct sk_buff *skb,
133 struct nf_hook_state *state)
135 return entry->hook(entry->priv, skb, state);
138 static inline void nf_hook_state_init(struct nf_hook_state *p,
141 struct net_device *indev,
142 struct net_device *outdev,
145 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
158 struct nf_sockopt_ops {
159 struct list_head list;
163 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
166 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
168 int (*compat_set)(struct sock *sk, int optval,
169 void __user *user, unsigned int len);
173 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
175 int (*compat_get)(struct sock *sk, int optval,
176 void __user *user, int *len);
178 /* Use the module struct to lock set/get code in place */
179 struct module *owner;
182 /* Function to register/unregister hook points. */
183 int nf_register_net_hook(struct net *net, const struct nf_hook_ops *ops);
184 void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *ops);
185 int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg,
187 void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg,
190 /* Functions to register get/setsockopt ranges (non-inclusive). You
191 need to check permissions yourself! */
192 int nf_register_sockopt(struct nf_sockopt_ops *reg);
193 void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
195 #ifdef CONFIG_JUMP_LABEL
196 extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
199 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state,
200 const struct nf_hook_entries *e, unsigned int i);
203 * nf_hook - call a netfilter hook
205 * Returns 1 if the hook has allowed the packet to pass. The function
206 * okfn must be invoked by the caller in this case. Any other return
207 * value indicates the packet has been consumed by the hook.
209 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
210 struct sock *sk, struct sk_buff *skb,
211 struct net_device *indev, struct net_device *outdev,
212 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
214 struct nf_hook_entries *hook_head = NULL;
217 #ifdef CONFIG_JUMP_LABEL
218 if (__builtin_constant_p(pf) &&
219 __builtin_constant_p(hook) &&
220 !static_key_false(&nf_hooks_needed[pf][hook]))
227 hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
230 hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
233 #ifdef CONFIG_NETFILTER_FAMILY_ARP
234 if (WARN_ON_ONCE(hook >= ARRAY_SIZE(net->nf.hooks_arp)))
236 hook_head = rcu_dereference(net->nf.hooks_arp[hook]);
240 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
241 hook_head = rcu_dereference(net->nf.hooks_bridge[hook]);
244 #if IS_ENABLED(CONFIG_DECNET)
246 hook_head = rcu_dereference(net->nf.hooks_decnet[hook]);
255 struct nf_hook_state state;
257 nf_hook_state_init(&state, hook, pf, indev, outdev,
260 ret = nf_hook_slow(skb, &state, hook_head, 0);
267 /* Activate hook; either okfn or kfree_skb called, unless a hook
268 returns NF_STOLEN (in which case, it's up to the hook to deal with
271 Returns -ERRNO if packet dropped. Zero means queued, stolen or
276 > I don't want nf_hook to return anything because people might forget
277 > about async and trust the return value to mean "packet was ok".
280 Just document it clearly, then you can expect some sense from kernel
285 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
286 struct sk_buff *skb, struct net_device *in, struct net_device *out,
287 int (*okfn)(struct net *, struct sock *, struct sk_buff *),
293 ((ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn)) == 1))
294 ret = okfn(net, sk, skb);
299 NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct sk_buff *skb,
300 struct net_device *in, struct net_device *out,
301 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
303 int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn);
305 ret = okfn(net, sk, skb);
310 NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
311 struct list_head *head, struct net_device *in, struct net_device *out,
312 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
314 struct sk_buff *skb, *next;
315 struct list_head sublist;
317 INIT_LIST_HEAD(&sublist);
318 list_for_each_entry_safe(skb, next, head, list) {
319 list_del(&skb->list);
320 if (nf_hook(pf, hook, net, sk, skb, in, out, okfn) == 1)
321 list_add_tail(&skb->list, &sublist);
323 /* Put passed packets back on main list */
324 list_splice(&sublist, head);
327 /* Call setsockopt() */
328 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
330 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
333 int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
334 char __user *opt, unsigned int len);
335 int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
336 char __user *opt, int *len);
339 /* Call this before modifying an existing packet: ensures it is
340 modifiable and linear to the point you care about (writable_len).
341 Returns true or false. */
342 int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
345 struct nf_queue_entry;
347 __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,
348 unsigned int dataoff, u_int8_t protocol,
349 unsigned short family);
351 __sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
352 unsigned int dataoff, unsigned int len,
353 u_int8_t protocol, unsigned short family);
354 int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
355 bool strict, unsigned short family);
356 int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry);
358 #include <net/flow.h>
361 enum nf_nat_manip_type;
363 enum ip_conntrack_dir;
366 int (*parse_nat_setup)(struct nf_conn *ct, enum nf_nat_manip_type manip,
367 const struct nlattr *attr);
368 void (*decode_session)(struct sk_buff *skb, struct flowi *fl);
369 unsigned int (*manip_pkt)(struct sk_buff *skb, struct nf_conn *ct,
370 enum nf_nat_manip_type mtype,
371 enum ip_conntrack_dir dir);
374 extern struct nf_nat_hook __rcu *nf_nat_hook;
377 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
379 #if IS_ENABLED(CONFIG_NF_NAT)
380 struct nf_nat_hook *nat_hook;
383 nat_hook = rcu_dereference(nf_nat_hook);
384 if (nat_hook && nat_hook->decode_session)
385 nat_hook->decode_session(skb, fl);
390 #else /* !CONFIG_NETFILTER */
392 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
393 struct sk_buff *skb, struct net_device *in, struct net_device *out,
394 int (*okfn)(struct net *, struct sock *, struct sk_buff *),
397 return okfn(net, sk, skb);
401 NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
402 struct sk_buff *skb, struct net_device *in, struct net_device *out,
403 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
405 return okfn(net, sk, skb);
409 NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
410 struct list_head *head, struct net_device *in, struct net_device *out,
411 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
416 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
417 struct sock *sk, struct sk_buff *skb,
418 struct net_device *indev, struct net_device *outdev,
419 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
425 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
428 #endif /*CONFIG_NETFILTER*/
430 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
431 #include <linux/netfilter/nf_conntrack_zones_common.h>
433 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
434 void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
435 struct nf_conntrack_tuple;
436 bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
437 const struct sk_buff *skb);
439 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
440 struct nf_conntrack_tuple;
441 static inline bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
442 const struct sk_buff *skb)
449 enum ip_conntrack_info;
452 int (*update)(struct net *net, struct sk_buff *skb);
453 void (*destroy)(struct nf_conntrack *);
454 bool (*get_tuple_skb)(struct nf_conntrack_tuple *,
455 const struct sk_buff *);
457 extern struct nf_ct_hook __rcu *nf_ct_hook;
461 struct nfnl_ct_hook {
462 struct nf_conn *(*get_ct)(const struct sk_buff *skb,
463 enum ip_conntrack_info *ctinfo);
464 size_t (*build_size)(const struct nf_conn *ct);
465 int (*build)(struct sk_buff *skb, struct nf_conn *ct,
466 enum ip_conntrack_info ctinfo,
467 u_int16_t ct_attr, u_int16_t ct_info_attr);
468 int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
469 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
470 u32 portid, u32 report);
471 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
472 enum ip_conntrack_info ctinfo, s32 off);
474 extern struct nfnl_ct_hook __rcu *nfnl_ct_hook;
477 * nf_skb_duplicated - TEE target has sent a packet
479 * When a xtables target sends a packet, the OUTPUT and POSTROUTING
480 * hooks are traversed again, i.e. nft and xtables are invoked recursively.
482 * This is used by xtables TEE target to prevent the duplicated skb from
483 * being duplicated again.
485 DECLARE_PER_CPU(bool, nf_skb_duplicated);
487 #endif /*__LINUX_NETFILTER_H*/