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);
80 enum nf_hook_ops_type {
86 /* User fills in from here down. */
88 struct net_device *dev;
91 enum nf_hook_ops_type hook_ops_type:8;
93 /* Hooks are ordered in ascending priority. */
97 struct nf_hook_entry {
102 struct nf_hook_entries_rcu_head {
103 struct rcu_head head;
107 struct nf_hook_entries {
108 u16 num_hook_entries;
110 struct nf_hook_entry hooks[];
112 /* trailer: pointers to original orig_ops of each hook,
113 * followed by rcu_head and scratch space used for freeing
114 * the structure via call_rcu.
116 * This is not part of struct nf_hook_entry since its only
117 * needed in slow path (hook register/unregister):
118 * const struct nf_hook_ops *orig_ops[]
120 * For the same reason, we store this at end -- its
121 * only needed when a hook is deleted, not during
122 * packet path processing:
123 * struct nf_hook_entries_rcu_head head
127 #ifdef CONFIG_NETFILTER
128 static inline struct nf_hook_ops **nf_hook_entries_get_hook_ops(const struct nf_hook_entries *e)
130 unsigned int n = e->num_hook_entries;
131 const void *hook_end;
133 hook_end = &e->hooks[n]; /* this is *past* ->hooks[]! */
135 return (struct nf_hook_ops **)hook_end;
139 nf_hook_entry_hookfn(const struct nf_hook_entry *entry, struct sk_buff *skb,
140 struct nf_hook_state *state)
142 return entry->hook(entry->priv, skb, state);
145 static inline void nf_hook_state_init(struct nf_hook_state *p,
148 struct net_device *indev,
149 struct net_device *outdev,
152 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
165 struct nf_sockopt_ops {
166 struct list_head list;
170 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
173 int (*set)(struct sock *sk, int optval, sockptr_t arg,
177 int (*get)(struct sock *sk, int optval, 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);
202 void nf_hook_slow_list(struct list_head *head, struct nf_hook_state *state,
203 const struct nf_hook_entries *e);
205 * nf_hook - call a netfilter hook
207 * Returns 1 if the hook has allowed the packet to pass. The function
208 * okfn must be invoked by the caller in this case. Any other return
209 * value indicates the packet has been consumed by the hook.
211 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
212 struct sock *sk, struct sk_buff *skb,
213 struct net_device *indev, struct net_device *outdev,
214 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
216 struct nf_hook_entries *hook_head = NULL;
219 #ifdef CONFIG_JUMP_LABEL
220 if (__builtin_constant_p(pf) &&
221 __builtin_constant_p(hook) &&
222 !static_key_false(&nf_hooks_needed[pf][hook]))
229 hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
232 hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
235 #ifdef CONFIG_NETFILTER_FAMILY_ARP
236 if (WARN_ON_ONCE(hook >= ARRAY_SIZE(net->nf.hooks_arp)))
238 hook_head = rcu_dereference(net->nf.hooks_arp[hook]);
242 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
243 hook_head = rcu_dereference(net->nf.hooks_bridge[hook]);
246 #if IS_ENABLED(CONFIG_DECNET)
248 hook_head = rcu_dereference(net->nf.hooks_decnet[hook]);
257 struct nf_hook_state state;
259 nf_hook_state_init(&state, hook, pf, indev, outdev,
262 ret = nf_hook_slow(skb, &state, hook_head, 0);
269 /* Activate hook; either okfn or kfree_skb called, unless a hook
270 returns NF_STOLEN (in which case, it's up to the hook to deal with
273 Returns -ERRNO if packet dropped. Zero means queued, stolen or
278 > I don't want nf_hook to return anything because people might forget
279 > about async and trust the return value to mean "packet was ok".
282 Just document it clearly, then you can expect some sense from kernel
287 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
288 struct sk_buff *skb, struct net_device *in, struct net_device *out,
289 int (*okfn)(struct net *, struct sock *, struct sk_buff *),
295 ((ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn)) == 1))
296 ret = okfn(net, sk, skb);
301 NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct sk_buff *skb,
302 struct net_device *in, struct net_device *out,
303 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
305 int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn);
307 ret = okfn(net, sk, skb);
312 NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
313 struct list_head *head, struct net_device *in, struct net_device *out,
314 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
316 struct nf_hook_entries *hook_head = NULL;
318 #ifdef CONFIG_JUMP_LABEL
319 if (__builtin_constant_p(pf) &&
320 __builtin_constant_p(hook) &&
321 !static_key_false(&nf_hooks_needed[pf][hook]))
328 hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
331 hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
339 struct nf_hook_state state;
341 nf_hook_state_init(&state, hook, pf, in, out, sk, net, okfn);
343 nf_hook_slow_list(head, &state, hook_head);
348 /* Call setsockopt() */
349 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, sockptr_t opt,
351 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
355 struct nf_queue_entry;
357 __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,
358 unsigned int dataoff, u_int8_t protocol,
359 unsigned short family);
361 __sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
362 unsigned int dataoff, unsigned int len,
363 u_int8_t protocol, unsigned short family);
364 int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
365 bool strict, unsigned short family);
366 int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry);
368 #include <net/flow.h>
371 enum nf_nat_manip_type;
373 enum ip_conntrack_dir;
376 int (*parse_nat_setup)(struct nf_conn *ct, enum nf_nat_manip_type manip,
377 const struct nlattr *attr);
378 void (*decode_session)(struct sk_buff *skb, struct flowi *fl);
379 unsigned int (*manip_pkt)(struct sk_buff *skb, struct nf_conn *ct,
380 enum nf_nat_manip_type mtype,
381 enum ip_conntrack_dir dir);
384 extern struct nf_nat_hook __rcu *nf_nat_hook;
387 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
389 #if IS_ENABLED(CONFIG_NF_NAT)
390 struct nf_nat_hook *nat_hook;
393 nat_hook = rcu_dereference(nf_nat_hook);
394 if (nat_hook && nat_hook->decode_session)
395 nat_hook->decode_session(skb, fl);
400 #else /* !CONFIG_NETFILTER */
402 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
403 struct sk_buff *skb, struct net_device *in, struct net_device *out,
404 int (*okfn)(struct net *, struct sock *, struct sk_buff *),
407 return okfn(net, sk, skb);
411 NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
412 struct sk_buff *skb, struct net_device *in, struct net_device *out,
413 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
415 return okfn(net, sk, skb);
419 NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
420 struct list_head *head, struct net_device *in, struct net_device *out,
421 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
426 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
427 struct sock *sk, struct sk_buff *skb,
428 struct net_device *indev, struct net_device *outdev,
429 int (*okfn)(struct net *, struct sock *, struct sk_buff *))
435 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
438 #endif /*CONFIG_NETFILTER*/
440 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
441 #include <linux/netfilter/nf_conntrack_zones_common.h>
443 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
444 void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
445 struct nf_conntrack_tuple;
446 bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
447 const struct sk_buff *skb);
449 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
450 struct nf_conntrack_tuple;
451 static inline bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
452 const struct sk_buff *skb)
459 enum ip_conntrack_info;
462 int (*update)(struct net *net, struct sk_buff *skb);
463 void (*destroy)(struct nf_conntrack *);
464 bool (*get_tuple_skb)(struct nf_conntrack_tuple *,
465 const struct sk_buff *);
467 extern struct nf_ct_hook __rcu *nf_ct_hook;
471 struct nfnl_ct_hook {
472 size_t (*build_size)(const struct nf_conn *ct);
473 int (*build)(struct sk_buff *skb, struct nf_conn *ct,
474 enum ip_conntrack_info ctinfo,
475 u_int16_t ct_attr, u_int16_t ct_info_attr);
476 int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
477 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
478 u32 portid, u32 report);
479 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
480 enum ip_conntrack_info ctinfo, s32 off);
482 extern struct nfnl_ct_hook __rcu *nfnl_ct_hook;
485 * nf_skb_duplicated - TEE target has sent a packet
487 * When a xtables target sends a packet, the OUTPUT and POSTROUTING
488 * hooks are traversed again, i.e. nft and xtables are invoked recursively.
490 * This is used by xtables TEE target to prevent the duplicated skb from
491 * being duplicated again.
493 DECLARE_PER_CPU(bool, nf_skb_duplicated);
495 #endif /*__LINUX_NETFILTER_H*/