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 static inline int NF_DROP_GETERR(int verdict)
20 return -(verdict >> NF_VERDICT_QBITS);
23 static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1,
24 const union nf_inet_addr *a2)
26 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
27 const unsigned long *ul1 = (const unsigned long *)a1;
28 const unsigned long *ul2 = (const unsigned long *)a2;
30 return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
32 return a1->all[0] == a2->all[0] &&
33 a1->all[1] == a2->all[1] &&
34 a1->all[2] == a2->all[2] &&
35 a1->all[3] == a2->all[3];
39 static inline void nf_inet_addr_mask(const union nf_inet_addr *a1,
40 union nf_inet_addr *result,
41 const union nf_inet_addr *mask)
43 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
44 const unsigned long *ua = (const unsigned long *)a1;
45 unsigned long *ur = (unsigned long *)result;
46 const unsigned long *um = (const unsigned long *)mask;
48 ur[0] = ua[0] & um[0];
49 ur[1] = ua[1] & um[1];
51 result->all[0] = a1->all[0] & mask->all[0];
52 result->all[1] = a1->all[1] & mask->all[1];
53 result->all[2] = a1->all[2] & mask->all[2];
54 result->all[3] = a1->all[3] & mask->all[3];
58 int netfilter_init(void);
66 struct nf_hook_state {
69 struct net_device *in;
70 struct net_device *out;
73 int (*okfn)(struct net *, struct sock *, struct sk_buff *);
76 typedef unsigned int nf_hookfn(void *priv,
78 const struct nf_hook_state *state);
80 /* User fills in from here down. */
82 struct net_device *dev;
86 /* Hooks are ordered in ascending priority. */
90 struct nf_hook_entry {
95 struct nf_hook_entries_rcu_head {
100 struct nf_hook_entries {
101 u16 num_hook_entries;
103 struct nf_hook_entry hooks[];
105 /* trailer: pointers to original orig_ops of each hook,
106 * followed by rcu_head and scratch space used for freeing
107 * the structure via call_rcu.
109 * This is not part of struct nf_hook_entry since its only
110 * needed in slow path (hook register/unregister):
111 * const struct nf_hook_ops *orig_ops[]
113 * For the same reason, we store this at end -- its
114 * only needed when a hook is deleted, not during
115 * packet path processing:
116 * struct nf_hook_entries_rcu_head head
120 #ifdef CONFIG_NETFILTER
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);
169 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
170 /* Use the module struct to lock set/get code in place */
171 struct module *owner;
174 /* Function to register/unregister hook points. */
175 int nf_register_net_hook(struct net *net, const struct nf_hook_ops *ops);
176 void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *ops);
177 int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg,
179 void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg,
182 /* Functions to register get/setsockopt ranges (non-inclusive). You
183 need to check permissions yourself! */
184 int nf_register_sockopt(struct nf_sockopt_ops *reg);
185 void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
187 #ifdef CONFIG_JUMP_LABEL
188 extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
191 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state,
192 const struct nf_hook_entries *e, unsigned int i);
194 void nf_hook_slow_list(struct list_head *head, struct nf_hook_state *state,
195 const struct nf_hook_entries *e);
197 * nf_hook - call a netfilter hook
199 * Returns 1 if the hook has allowed the packet to pass. The function
200 * okfn must be invoked by the caller in this case. Any other return
201 * value indicates the packet has been consumed by the hook.
203 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
204 struct sock *sk, struct sk_buff *skb,
205 struct net_device *indev, struct net_device *outdev,
206 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
208 struct nf_hook_entries *hook_head = NULL;
211 #ifdef CONFIG_JUMP_LABEL
212 if (__builtin_constant_p(pf) &&
213 __builtin_constant_p(hook) &&
214 !static_key_false(&nf_hooks_needed[pf][hook]))
221 hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
224 hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
227 #ifdef CONFIG_NETFILTER_FAMILY_ARP
228 if (WARN_ON_ONCE(hook >= ARRAY_SIZE(net->nf.hooks_arp)))
230 hook_head = rcu_dereference(net->nf.hooks_arp[hook]);
234 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
235 hook_head = rcu_dereference(net->nf.hooks_bridge[hook]);
238 #if IS_ENABLED(CONFIG_DECNET)
240 hook_head = rcu_dereference(net->nf.hooks_decnet[hook]);
249 struct nf_hook_state state;
251 nf_hook_state_init(&state, hook, pf, indev, outdev,
254 ret = nf_hook_slow(skb, &state, hook_head, 0);
261 /* Activate hook; either okfn or kfree_skb called, unless a hook
262 returns NF_STOLEN (in which case, it's up to the hook to deal with
265 Returns -ERRNO if packet dropped. Zero means queued, stolen or
270 > I don't want nf_hook to return anything because people might forget
271 > about async and trust the return value to mean "packet was ok".
274 Just document it clearly, then you can expect some sense from kernel
279 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
280 struct sk_buff *skb, struct net_device *in, struct net_device *out,
281 int (*okfn)(struct net *, struct sock *, struct sk_buff *),
287 ((ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn)) == 1))
288 ret = okfn(net, sk, skb);
293 NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct sk_buff *skb,
294 struct net_device *in, struct net_device *out,
295 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
297 int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn);
299 ret = okfn(net, sk, skb);
304 NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
305 struct list_head *head, struct net_device *in, struct net_device *out,
306 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
308 struct nf_hook_entries *hook_head = NULL;
310 #ifdef CONFIG_JUMP_LABEL
311 if (__builtin_constant_p(pf) &&
312 __builtin_constant_p(hook) &&
313 !static_key_false(&nf_hooks_needed[pf][hook]))
320 hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
323 hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
331 struct nf_hook_state state;
333 nf_hook_state_init(&state, hook, pf, in, out, sk, net, okfn);
335 nf_hook_slow_list(head, &state, hook_head);
340 /* Call setsockopt() */
341 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
343 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
347 struct nf_queue_entry;
349 __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,
350 unsigned int dataoff, u_int8_t protocol,
351 unsigned short family);
353 __sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
354 unsigned int dataoff, unsigned int len,
355 u_int8_t protocol, unsigned short family);
356 int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
357 bool strict, unsigned short family);
358 int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry);
360 #include <net/flow.h>
363 enum nf_nat_manip_type;
365 enum ip_conntrack_dir;
368 int (*parse_nat_setup)(struct nf_conn *ct, enum nf_nat_manip_type manip,
369 const struct nlattr *attr);
370 void (*decode_session)(struct sk_buff *skb, struct flowi *fl);
371 unsigned int (*manip_pkt)(struct sk_buff *skb, struct nf_conn *ct,
372 enum nf_nat_manip_type mtype,
373 enum ip_conntrack_dir dir);
376 extern struct nf_nat_hook __rcu *nf_nat_hook;
379 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
381 #if IS_ENABLED(CONFIG_NF_NAT)
382 struct nf_nat_hook *nat_hook;
385 nat_hook = rcu_dereference(nf_nat_hook);
386 if (nat_hook && nat_hook->decode_session)
387 nat_hook->decode_session(skb, fl);
392 #else /* !CONFIG_NETFILTER */
394 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
395 struct sk_buff *skb, struct net_device *in, struct net_device *out,
396 int (*okfn)(struct net *, struct sock *, struct sk_buff *),
399 return okfn(net, sk, skb);
403 NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
404 struct sk_buff *skb, struct net_device *in, struct net_device *out,
405 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
407 return okfn(net, sk, skb);
411 NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
412 struct list_head *head, struct net_device *in, struct net_device *out,
413 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
418 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
419 struct sock *sk, struct sk_buff *skb,
420 struct net_device *indev, struct net_device *outdev,
421 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
427 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
430 #endif /*CONFIG_NETFILTER*/
432 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
433 #include <linux/netfilter/nf_conntrack_zones_common.h>
435 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
436 void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
437 struct nf_conntrack_tuple;
438 bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
439 const struct sk_buff *skb);
441 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
442 struct nf_conntrack_tuple;
443 static inline bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
444 const struct sk_buff *skb)
451 enum ip_conntrack_info;
454 int (*update)(struct net *net, struct sk_buff *skb);
455 void (*destroy)(struct nf_conntrack *);
456 bool (*get_tuple_skb)(struct nf_conntrack_tuple *,
457 const struct sk_buff *);
459 extern struct nf_ct_hook __rcu *nf_ct_hook;
463 struct nfnl_ct_hook {
464 struct nf_conn *(*get_ct)(const struct sk_buff *skb,
465 enum ip_conntrack_info *ctinfo);
466 size_t (*build_size)(const struct nf_conn *ct);
467 int (*build)(struct sk_buff *skb, struct nf_conn *ct,
468 enum ip_conntrack_info ctinfo,
469 u_int16_t ct_attr, u_int16_t ct_info_attr);
470 int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
471 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
472 u32 portid, u32 report);
473 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
474 enum ip_conntrack_info ctinfo, s32 off);
476 extern struct nfnl_ct_hook __rcu *nfnl_ct_hook;
479 * nf_skb_duplicated - TEE target has sent a packet
481 * When a xtables target sends a packet, the OUTPUT and POSTROUTING
482 * hooks are traversed again, i.e. nft and xtables are invoked recursively.
484 * This is used by xtables TEE target to prevent the duplicated skb from
485 * being duplicated again.
487 DECLARE_PER_CPU(bool, nf_skb_duplicated);
489 #endif /*__LINUX_NETFILTER_H*/