[linux-2.6-block.git] / include / linux / netfilter.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_NETFILTER_H
#define __LINUX_NETFILTER_H

#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/net.h>
#include <linux/if.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/wait.h>
#include <linux/list.h>
#include <linux/static_key.h>
#include <linux/netfilter_defs.h>
#include <linux/netdevice.h>
#include <net/net_namespace.h>

#ifdef CONFIG_NETFILTER
static inline int NF_DROP_GETERR(int verdict)
{
	return -(verdict >> NF_VERDICT_QBITS);
}

static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1,
				   const union nf_inet_addr *a2)
{
	return a1->all[0] == a2->all[0] &&
	       a1->all[1] == a2->all[1] &&
	       a1->all[2] == a2->all[2] &&
	       a1->all[3] == a2->all[3];
}

static inline void nf_inet_addr_mask(const union nf_inet_addr *a1,
				     union nf_inet_addr *result,
				     const union nf_inet_addr *mask)
{
	result->all[0] = a1->all[0] & mask->all[0];
	result->all[1] = a1->all[1] & mask->all[1];
	result->all[2] = a1->all[2] & mask->all[2];
	result->all[3] = a1->all[3] & mask->all[3];
}

int netfilter_init(void);

struct sk_buff;

struct nf_hook_ops;

struct sock;

struct nf_hook_state {
	unsigned int hook;
	u_int8_t pf;
	struct net_device *in;
	struct net_device *out;
	struct sock *sk;
	struct net *net;
	int (*okfn)(struct net *, struct sock *, struct sk_buff *);
};

typedef unsigned int nf_hookfn(void *priv,
			       struct sk_buff *skb,
			       const struct nf_hook_state *state);
struct nf_hook_ops {
	/* User fills in from here down. */
	nf_hookfn		*hook;
	struct net_device	*dev;
	void			*priv;
	u_int8_t		pf;
	unsigned int		hooknum;
	/* Hooks are ordered in ascending priority. */
	int			priority;
};

struct nf_hook_entry {
	nf_hookfn			*hook;
	void				*priv;
};

struct nf_hook_entries_rcu_head {
	struct rcu_head head;
	void	*allocation;
};

struct nf_hook_entries {
	u16				num_hook_entries;
	/* padding */
	struct nf_hook_entry		hooks[];

	/* trailer: pointers to original orig_ops of each hook,
	 * followed by rcu_head and scratch space used for freeing
	 * the structure via call_rcu.
	 *
	 *   This is not part of struct nf_hook_entry since its only
	 *   needed in slow path (hook register/unregister):
	 * const struct nf_hook_ops     *orig_ops[]
	 *
	 *   For the same reason, we store this at end -- its
	 *   only needed when a hook is deleted, not during
	 *   packet path processing:
	 * struct nf_hook_entries_rcu_head     head
	 */
};

static inline struct nf_hook_ops **nf_hook_entries_get_hook_ops(const struct nf_hook_entries *e)
{
	unsigned int n = e->num_hook_entries;
	const void *hook_end;

	hook_end = &e->hooks[n]; /* this is *past* ->hooks[]! */

	return (struct nf_hook_ops **)hook_end;
}

static inline int
nf_hook_entry_hookfn(const struct nf_hook_entry *entry, struct sk_buff *skb,
		     struct nf_hook_state *state)
{
	return entry->hook(entry->priv, skb, state);
}

static inline void nf_hook_state_init(struct nf_hook_state *p,
				      unsigned int hook,
				      u_int8_t pf,
				      struct net_device *indev,
				      struct net_device *outdev,
				      struct sock *sk,
				      struct net *net,
				      int (*okfn)(struct net *, struct sock *, struct sk_buff *))
{
	p->hook = hook;
	p->pf = pf;
	p->in = indev;
	p->out = outdev;
	p->sk = sk;
	p->net = net;
	p->okfn = okfn;
}


struct nf_sockopt_ops {
	struct list_head list;

	u_int8_t pf;

	/* Non-inclusive ranges: use 0/0/NULL to never get called. */
	int set_optmin;
	int set_optmax;
	int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
#ifdef CONFIG_COMPAT
	int (*compat_set)(struct sock *sk, int optval,
			void __user *user, unsigned int len);
#endif
	int get_optmin;
	int get_optmax;
	int (*get)(struct sock *sk, int optval, void __user *user, int *len);
#ifdef CONFIG_COMPAT
	int (*compat_get)(struct sock *sk, int optval,
			void __user *user, int *len);
#endif
	/* Use the module struct to lock set/get code in place */
	struct module *owner;
};

/* Function to register/unregister hook points. */
int nf_register_net_hook(struct net *net, const struct nf_hook_ops *ops);
void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *ops);
int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg,
			  unsigned int n);
void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg,
			     unsigned int n);

/* Functions to register get/setsockopt ranges (non-inclusive).  You
   need to check permissions yourself! */
int nf_register_sockopt(struct nf_sockopt_ops *reg);
void nf_unregister_sockopt(struct nf_sockopt_ops *reg);

#ifdef HAVE_JUMP_LABEL
extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
#endif

int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state,
		 const struct nf_hook_entries *e, unsigned int i);

/**
 *	nf_hook - call a netfilter hook
 *
 *	Returns 1 if the hook has allowed the packet to pass.  The function
 *	okfn must be invoked by the caller in this case.  Any other return
 *	value indicates the packet has been consumed by the hook.
 */
static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
			  struct sock *sk, struct sk_buff *skb,
			  struct net_device *indev, struct net_device *outdev,
			  int (*okfn)(struct net *, struct sock *, struct sk_buff *))
{
	struct nf_hook_entries *hook_head = NULL;
	int ret = 1;

#ifdef HAVE_JUMP_LABEL
	if (__builtin_constant_p(pf) &&
	    __builtin_constant_p(hook) &&
	    !static_key_false(&nf_hooks_needed[pf][hook]))
		return 1;
#endif

	rcu_read_lock();
	switch (pf) {
	case NFPROTO_IPV4:
		hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
		break;
	case NFPROTO_IPV6:
		hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
		break;
	case NFPROTO_ARP:
#ifdef CONFIG_NETFILTER_FAMILY_ARP
		hook_head = rcu_dereference(net->nf.hooks_arp[hook]);
#endif
		break;
	case NFPROTO_BRIDGE:
#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
		hook_head = rcu_dereference(net->nf.hooks_bridge[hook]);
#endif
		break;
#if IS_ENABLED(CONFIG_DECNET)
	case NFPROTO_DECNET:
		hook_head = rcu_dereference(net->nf.hooks_decnet[hook]);
		break;
#endif
	default:
		WARN_ON_ONCE(1);
		break;
	}

	if (hook_head) {
		struct nf_hook_state state;

		nf_hook_state_init(&state, hook, pf, indev, outdev,
				   sk, net, okfn);

		ret = nf_hook_slow(skb, &state, hook_head, 0);
	}
	rcu_read_unlock();

	return ret;
}

/* Activate hook; either okfn or kfree_skb called, unless a hook
   returns NF_STOLEN (in which case, it's up to the hook to deal with
   the consequences).

   Returns -ERRNO if packet dropped.  Zero means queued, stolen or
   accepted.
*/

/* RR:
   > I don't want nf_hook to return anything because people might forget
   > about async and trust the return value to mean "packet was ok".

   AK:
   Just document it clearly, then you can expect some sense from kernel
   coders :)
*/

static inline int
NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
	     struct sk_buff *skb, struct net_device *in, struct net_device *out,
	     int (*okfn)(struct net *, struct sock *, struct sk_buff *),
	     bool cond)
{
	int ret;

	if (!cond ||
	    ((ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn)) == 1))
		ret = okfn(net, sk, skb);
	return ret;
}

static inline int
NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct sk_buff *skb,
	struct net_device *in, struct net_device *out,
	int (*okfn)(struct net *, struct sock *, struct sk_buff *))
{
	int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn);
	if (ret == 1)
		ret = okfn(net, sk, skb);
	return ret;
}

static inline void
NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
	     struct list_head *head, struct net_device *in, struct net_device *out,
	     int (*okfn)(struct net *, struct sock *, struct sk_buff *))
{
	struct sk_buff *skb, *next;
	struct list_head sublist;

	INIT_LIST_HEAD(&sublist);
	list_for_each_entry_safe(skb, next, head, list) {
		list_del(&skb->list);
		if (nf_hook(pf, hook, net, sk, skb, in, out, okfn) == 1)
			list_add_tail(&skb->list, &sublist);
	}
	/* Put passed packets back on main list */
	list_splice(&sublist, head);
}

/* Call setsockopt() */
int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
		  unsigned int len);
int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
		  int *len);
#ifdef CONFIG_COMPAT
int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
		char __user *opt, unsigned int len);
int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
		char __user *opt, int *len);
#endif

/* Call this before modifying an existing packet: ensures it is
   modifiable and linear to the point you care about (writable_len).
   Returns true or false. */
int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);

struct flowi;
struct nf_queue_entry;

__sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,
		    unsigned int dataoff, u_int8_t protocol,
		    unsigned short family);

__sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
			    unsigned int dataoff, unsigned int len,
			    u_int8_t protocol, unsigned short family);
int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
	     bool strict, unsigned short family);
int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry);

#include <net/flow.h>

struct nf_conn;
enum nf_nat_manip_type;
struct nlattr;
enum ip_conntrack_dir;

struct nf_nat_hook {
	int (*parse_nat_setup)(struct nf_conn *ct, enum nf_nat_manip_type manip,
			       const struct nlattr *attr);
	void (*decode_session)(struct sk_buff *skb, struct flowi *fl);
	unsigned int (*manip_pkt)(struct sk_buff *skb, struct nf_conn *ct,
				  enum nf_nat_manip_type mtype,
				  enum ip_conntrack_dir dir);
};

extern struct nf_nat_hook __rcu *nf_nat_hook;

static inline void
nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
{
#ifdef CONFIG_NF_NAT_NEEDED
	struct nf_nat_hook *nat_hook;

	rcu_read_lock();
	nat_hook = rcu_dereference(nf_nat_hook);
	if (nat_hook && nat_hook->decode_session)
		nat_hook->decode_session(skb, fl);
	rcu_read_unlock();
#endif
}

#else /* !CONFIG_NETFILTER */
static inline int
NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
	     struct sk_buff *skb, struct net_device *in, struct net_device *out,
	     int (*okfn)(struct net *, struct sock *, struct sk_buff *),
	     bool cond)
{
	return okfn(net, sk, skb);
}

static inline int
NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
	struct sk_buff *skb, struct net_device *in, struct net_device *out,
	int (*okfn)(struct net *, struct sock *, struct sk_buff *))
{
	return okfn(net, sk, skb);
}

static inline void
NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
	     struct list_head *head, struct net_device *in, struct net_device *out,
	     int (*okfn)(struct net *, struct sock *, struct sk_buff *))
{
	/* nothing to do */
}

static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
			  struct sock *sk, struct sk_buff *skb,
			  struct net_device *indev, struct net_device *outdev,
			  int (*okfn)(struct net *, struct sock *, struct sk_buff *))
{
	return 1;
}
struct flowi;
static inline void
nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
{
}
#endif /*CONFIG_NETFILTER*/

#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
#include <linux/netfilter/nf_conntrack_zones_common.h>

extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
struct nf_conntrack_tuple;
bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
			 const struct sk_buff *skb);
#else
static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
struct nf_conntrack_tuple;
static inline bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
				       const struct sk_buff *skb)
{
	return false;
}
#endif

struct nf_conn;
enum ip_conntrack_info;

struct nf_ct_hook {
	int (*update)(struct net *net, struct sk_buff *skb);
	void (*destroy)(struct nf_conntrack *);
	bool (*get_tuple_skb)(struct nf_conntrack_tuple *,
			      const struct sk_buff *);
};
extern struct nf_ct_hook __rcu *nf_ct_hook;

struct nlattr;

struct nfnl_ct_hook {
	struct nf_conn *(*get_ct)(const struct sk_buff *skb,
				  enum ip_conntrack_info *ctinfo);
	size_t (*build_size)(const struct nf_conn *ct);
	int (*build)(struct sk_buff *skb, struct nf_conn *ct,
		     enum ip_conntrack_info ctinfo,
		     u_int16_t ct_attr, u_int16_t ct_info_attr);
	int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
	int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
			     u32 portid, u32 report);
	void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
			   enum ip_conntrack_info ctinfo, s32 off);
};
extern struct nfnl_ct_hook __rcu *nfnl_ct_hook;

/**
 * nf_skb_duplicated - TEE target has sent a packet
 *
 * When a xtables target sends a packet, the OUTPUT and POSTROUTING
 * hooks are traversed again, i.e. nft and xtables are invoked recursively.
 *
 * This is used by xtables TEE target to prevent the duplicated skb from
 * being duplicated again.
 */
DECLARE_PER_CPU(bool, nf_skb_duplicated);

#endif /*__LINUX_NETFILTER_H*/
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	#ifndef __LINUX_NETFILTER_H
	3	#define __LINUX_NETFILTER_H
	4
1da177e4	5	#include <linux/init.h>
1da177e4 LT	6	#include <linux/skbuff.h>
	7	#include <linux/net.h>
	8	#include <linux/if.h>
2e3075a2 JE	9	#include <linux/in.h>
2e3075a2 JE	10	#include <linux/in6.h>
1da177e4 LT	11	#include <linux/wait.h>
1da177e4 LT	12	#include <linux/list.h>
d1c85c2e	13	#include <linux/static_key.h>
a263653e	14	#include <linux/netfilter_defs.h>
085db2c0 EB	15	#include <linux/netdevice.h>
085db2c0 EB	16	#include <net/net_namespace.h>
a263653e	17
1da177e4	18	#ifdef CONFIG_NETFILTER
f615df76 FW	19	static inline int NF_DROP_GETERR(int verdict)
	20	{
	21	return -(verdict >> NF_VERDICT_QBITS);
	22	}
1da177e4	23
b8beedd2 PM	24	static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1,
	25	const union nf_inet_addr *a2)
	26	{
	27	return a1->all[0] == a2->all[0] &&
	28	a1->all[1] == a2->all[1] &&
	29	a1->all[2] == a2->all[2] &&
	30	a1->all[3] == a2->all[3];
	31	}
	32
efdedd54 DF	33	static inline void nf_inet_addr_mask(const union nf_inet_addr *a1,
	34	union nf_inet_addr *result,
	35	const union nf_inet_addr *mask)
	36	{
	37	result->all[0] = a1->all[0] & mask->all[0];
	38	result->all[1] = a1->all[1] & mask->all[1];
	39	result->all[2] = a1->all[2] & mask->all[2];
	40	result->all[3] = a1->all[3] & mask->all[3];
	41	}
	42
a0f4ecf3	43	int netfilter_init(void);
1da177e4	44
1da177e4	45	struct sk_buff;
1da177e4	46
795aa6ef	47	struct nf_hook_ops;
cfdfab31	48
1c984f8a DM	49	struct sock;
1c984f8a DM	50
cfdfab31 DM	51	struct nf_hook_state {
cfdfab31 DM	52	unsigned int hook;
cfdfab31 DM	53	u_int8_t pf;
	54	struct net_device *in;
	55	struct net_device *out;
1c984f8a	56	struct sock *sk;
b11b1f65	57	struct net *net;
0c4b51f0	58	int (okfn)(struct net , struct sock , struct sk_buff );
cfdfab31 DM	59	};
cfdfab31 DM	60
e3b37f11 AC	61	typedef unsigned int nf_hookfn(void *priv,
	62	struct sk_buff *skb,
	63	const struct nf_hook_state *state);
	64	struct nf_hook_ops {
e3b37f11 AC	65	/* User fills in from here down. */
	66	nf_hookfn *hook;
	67	struct net_device *dev;
	68	void *priv;
	69	u_int8_t pf;
	70	unsigned int hooknum;
	71	/* Hooks are ordered in ascending priority. */
	72	int priority;
	73	};
	74
	75	struct nf_hook_entry {
d415b9eb AC	76	nf_hookfn *hook;
d415b9eb AC	77	void *priv;
e3b37f11 AC	78	};
e3b37f11 AC	79
8c873e21 FW	80	struct nf_hook_entries_rcu_head {
	81	struct rcu_head head;
	82	void *allocation;
	83	};
	84
960632ec AC	85	struct nf_hook_entries {
	86	u16 num_hook_entries;
	87	/* padding */
	88	struct nf_hook_entry hooks[];
	89
8c873e21 FW	90	/* trailer: pointers to original orig_ops of each hook,
	91	* followed by rcu_head and scratch space used for freeing
	92	* the structure via call_rcu.
960632ec	93	*
8c873e21 FW	94	* This is not part of struct nf_hook_entry since its only
8c873e21 FW	95	* needed in slow path (hook register/unregister):
960632ec	96	* const struct nf_hook_ops *orig_ops[]
8c873e21 FW	97	*
	98	* For the same reason, we store this at end -- its
	99	* only needed when a hook is deleted, not during
	100	* packet path processing:
	101	* struct nf_hook_entries_rcu_head head
960632ec AC	102	*/
960632ec AC	103	};
0aa8c57a	104
960632ec	105	static inline struct nf_hook_ops *nf_hook_entries_get_hook_ops(const struct nf_hook_entries e)
0aa8c57a	106	{
960632ec AC	107	unsigned int n = e->num_hook_entries;
	108	const void *hook_end;
	109
	110	hook_end = &e->hooks[n]; /* this is past ->hooks[]! */
	111
	112	return (struct nf_hook_ops **)hook_end;
0aa8c57a AC	113	}
	114
	115	static inline int
	116	nf_hook_entry_hookfn(const struct nf_hook_entry entry, struct sk_buff skb,
	117	struct nf_hook_state *state)
	118	{
d415b9eb	119	return entry->hook(entry->priv, skb, state);
0aa8c57a AC	120	}
0aa8c57a AC	121
107a9f4d DM	122	static inline void nf_hook_state_init(struct nf_hook_state *p,
107a9f4d DM	123	unsigned int hook,
1610a73c	124	u_int8_t pf,
107a9f4d DM	125	struct net_device *indev,
107a9f4d DM	126	struct net_device *outdev,
1c984f8a	127	struct sock *sk,
b11b1f65	128	struct net *net,
0c4b51f0	129	int (okfn)(struct net , struct sock , struct sk_buff ))
107a9f4d DM	130	{
107a9f4d DM	131	p->hook = hook;
107a9f4d DM	132	p->pf = pf;
	133	p->in = indev;
	134	p->out = outdev;
1c984f8a	135	p->sk = sk;
b11b1f65	136	p->net = net;
107a9f4d DM	137	p->okfn = okfn;
	138	}
	139
1da177e4	140
1da177e4	141
d94d9fee	142	struct nf_sockopt_ops {
1da177e4 LT	143	struct list_head list;
1da177e4 LT	144
76108cea	145	u_int8_t pf;
1da177e4 LT	146
	147	/* Non-inclusive ranges: use 0/0/NULL to never get called. */
	148	int set_optmin;
	149	int set_optmax;
	150	int (set)(struct sock sk, int optval, void __user *user, unsigned int len);
c30f540b	151	#ifdef CONFIG_COMPAT
3fdadf7d DM	152	int (compat_set)(struct sock sk, int optval,
3fdadf7d DM	153	void __user *user, unsigned int len);
c30f540b	154	#endif
1da177e4 LT	155	int get_optmin;
	156	int get_optmax;
	157	int (get)(struct sock sk, int optval, void __user user, int len);
c30f540b	158	#ifdef CONFIG_COMPAT
3fdadf7d DM	159	int (compat_get)(struct sock sk, int optval,
3fdadf7d DM	160	void __user user, int len);
c30f540b	161	#endif
16fcec35 NH	162	/* Use the module struct to lock set/get code in place */
16fcec35 NH	163	struct module *owner;
1da177e4 LT	164	};
1da177e4 LT	165
1da177e4	166	/* Function to register/unregister hook points. */
085db2c0 EB	167	int nf_register_net_hook(struct net net, const struct nf_hook_ops ops);
	168	void nf_unregister_net_hook(struct net net, const struct nf_hook_ops ops);
	169	int nf_register_net_hooks(struct net net, const struct nf_hook_ops reg,
	170	unsigned int n);
	171	void nf_unregister_net_hooks(struct net net, const struct nf_hook_ops reg,
	172	unsigned int n);
	173
1da177e4 LT	174	/* Functions to register get/setsockopt ranges (non-inclusive). You
	175	need to check permissions yourself! */
	176	int nf_register_sockopt(struct nf_sockopt_ops *reg);
	177	void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
	178
d1c85c2e	179	#ifdef HAVE_JUMP_LABEL
c5905afb	180	extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
a2d7ec58 ED	181	#endif
a2d7ec58 ED	182
01886bd9	183	int nf_hook_slow(struct sk_buff skb, struct nf_hook_state state,
960632ec	184	const struct nf_hook_entries *e, unsigned int i);
16a6677f PM	185
16a6677f PM	186	/**
1610a73c	187	* nf_hook - call a netfilter hook
b8d0aad0	188	*
16a6677f PM	189	* Returns 1 if the hook has allowed the packet to pass. The function
	190	* okfn must be invoked by the caller in this case. Any other return
	191	* value indicates the packet has been consumed by the hook.
	192	*/
1610a73c PNA	193	static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
	194	struct sock sk, struct sk_buff skb,
	195	struct net_device indev, struct net_device outdev,
	196	int (okfn)(struct net , struct sock , struct sk_buff ))
16a6677f	197	{
b0f38338	198	struct nf_hook_entries *hook_head = NULL;
e3b37f11	199	int ret = 1;
af4610c3 FW	200
	201	#ifdef HAVE_JUMP_LABEL
	202	if (__builtin_constant_p(pf) &&
	203	__builtin_constant_p(hook) &&
	204	!static_key_false(&nf_hooks_needed[pf][hook]))
	205	return 1;
	206	#endif
	207
e3b37f11	208	rcu_read_lock();
b0f38338 FW	209	switch (pf) {
	210	case NFPROTO_IPV4:
	211	hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
	212	break;
	213	case NFPROTO_IPV6:
	214	hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
	215	break;
	216	case NFPROTO_ARP:
2a95183a	217	#ifdef CONFIG_NETFILTER_FAMILY_ARP
b0f38338	218	hook_head = rcu_dereference(net->nf.hooks_arp[hook]);
2a95183a	219	#endif
b0f38338 FW	220	break;
b0f38338 FW	221	case NFPROTO_BRIDGE:
2a95183a	222	#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
b0f38338	223	hook_head = rcu_dereference(net->nf.hooks_bridge[hook]);
2a95183a	224	#endif
b0f38338	225	break;
bb4badf3	226	#if IS_ENABLED(CONFIG_DECNET)
b0f38338 FW	227	case NFPROTO_DECNET:
	228	hook_head = rcu_dereference(net->nf.hooks_decnet[hook]);
	229	break;
bb4badf3	230	#endif
b0f38338 FW	231	default:
	232	WARN_ON_ONCE(1);
	233	break;
	234	}
	235
e3b37f11	236	if (hook_head) {
107a9f4d	237	struct nf_hook_state state;
cfdfab31	238
01886bd9	239	nf_hook_state_init(&state, hook, pf, indev, outdev,
1610a73c	240	sk, net, okfn);
fe72926b	241
960632ec	242	ret = nf_hook_slow(skb, &state, hook_head, 0);
cfdfab31	243	}
e3b37f11 AC	244	rcu_read_unlock();
	245
	246	return ret;
16a6677f PM	247	}
16a6677f PM	248
1da177e4 LT	249	/* Activate hook; either okfn or kfree_skb called, unless a hook
	250	returns NF_STOLEN (in which case, it's up to the hook to deal with
	251	the consequences).
	252
	253	Returns -ERRNO if packet dropped. Zero means queued, stolen or
	254	accepted.
	255	*/
	256
	257	/* RR:
	258	> I don't want nf_hook to return anything because people might forget
	259	> about async and trust the return value to mean "packet was ok".
	260
	261	AK:
	262	Just document it clearly, then you can expect some sense from kernel
	263	coders :)
	264	*/
	265
2249065f	266	static inline int
29a26a56	267	NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net net, struct sock sk,
7026b1dd	268	struct sk_buff skb, struct net_device in, struct net_device *out,
0c4b51f0 EB	269	int (okfn)(struct net , struct sock , struct sk_buff ),
0c4b51f0 EB	270	bool cond)
2249065f	271	{
4bac6b18 PM	272	int ret;
	273
	274	if (!cond \|\|
1610a73c	275	((ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn)) == 1))
0c4b51f0	276	ret = okfn(net, sk, skb);
2249065f JE	277	return ret;
2249065f JE	278	}
1da177e4	279
2249065f	280	static inline int
29a26a56	281	NF_HOOK(uint8_t pf, unsigned int hook, struct net net, struct sock sk, struct sk_buff *skb,
2249065f	282	struct net_device in, struct net_device out,
0c4b51f0	283	int (okfn)(struct net , struct sock , struct sk_buff ))
2249065f	284	{
1610a73c PNA	285	int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn);
	286	if (ret == 1)
	287	ret = okfn(net, sk, skb);
	288	return ret;
2249065f	289	}
1da177e4	290
17266ee9 EC	291	static inline void
	292	NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net net, struct sock sk,
	293	struct list_head head, struct net_device in, struct net_device *out,
	294	int (okfn)(struct net , struct sock , struct sk_buff ))
	295	{
	296	struct sk_buff skb, next;
9f17dbf0	297	struct list_head sublist;
17266ee9	298
9f17dbf0	299	INIT_LIST_HEAD(&sublist);
17266ee9	300	list_for_each_entry_safe(skb, next, head, list) {
9f17dbf0 EC	301	list_del(&skb->list);
	302	if (nf_hook(pf, hook, net, sk, skb, in, out, okfn) == 1)
	303	list_add_tail(&skb->list, &sublist);
17266ee9	304	}
9f17dbf0 EC	305	/* Put passed packets back on main list */
9f17dbf0 EC	306	list_splice(&sublist, head);
17266ee9 EC	307	}
17266ee9 EC	308
1da177e4	309	/* Call setsockopt() */
76108cea	310	int nf_setsockopt(struct sock sk, u_int8_t pf, int optval, char __user opt,
b7058842	311	unsigned int len);
76108cea	312	int nf_getsockopt(struct sock sk, u_int8_t pf, int optval, char __user opt,
1da177e4	313	int *len);
c30f540b	314	#ifdef CONFIG_COMPAT
76108cea	315	int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
b7058842	316	char __user *opt, unsigned int len);
76108cea	317	int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
3fdadf7d	318	char __user opt, int len);
c30f540b	319	#endif
3fdadf7d	320
089af26c HW	321	/* Call this before modifying an existing packet: ensures it is
	322	modifiable and linear to the point you care about (writable_len).
	323	Returns true or false. */
a0f4ecf3	324	int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
089af26c	325
1841a4c7	326	struct flowi;
02f014d8	327	struct nf_queue_entry;
c01cd429	328
ef71fe27 PNA	329	__sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,
	330	unsigned int dataoff, u_int8_t protocol,
	331	unsigned short family);
422c346f	332
f7dcbe2f PNA	333	__sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
	334	unsigned int dataoff, unsigned int len,
	335	u_int8_t protocol, unsigned short family);
3f87c08c PNA	336	int nf_route(struct net net, struct dst_entry dst, struct flowi fl,
3f87c08c PNA	337	bool strict, unsigned short family);
ce388f45	338	int nf_reroute(struct sk_buff skb, struct nf_queue_entry entry);
d63a6507	339
eb9c7ebe	340	#include <net/flow.h>
2c205dd3 PNA	341
	342	struct nf_conn;
	343	enum nf_nat_manip_type;
	344	struct nlattr;
368982cd	345	enum ip_conntrack_dir;
2c205dd3 PNA	346
	347	struct nf_nat_hook {
	348	int (parse_nat_setup)(struct nf_conn ct, enum nf_nat_manip_type manip,
	349	const struct nlattr *attr);
	350	void (decode_session)(struct sk_buff skb, struct flowi *fl);
368982cd PNA	351	unsigned int (manip_pkt)(struct sk_buff skb, struct nf_conn *ct,
	352	enum nf_nat_manip_type mtype,
	353	enum ip_conntrack_dir dir);
2c205dd3 PNA	354	};
	355
	356	extern struct nf_nat_hook __rcu *nf_nat_hook;
eb9c7ebe PM	357
eb9c7ebe PM	358	static inline void
76108cea	359	nf_nat_decode_session(struct sk_buff skb, struct flowi fl, u_int8_t family)
eb9c7ebe	360	{
051578cc	361	#ifdef CONFIG_NF_NAT_NEEDED
2c205dd3	362	struct nf_nat_hook *nat_hook;
eb9c7ebe	363
c7232c99	364	rcu_read_lock();
2c205dd3	365	nat_hook = rcu_dereference(nf_nat_hook);
155fb5c5	366	if (nat_hook && nat_hook->decode_session)
2c205dd3	367	nat_hook->decode_session(skb, fl);
c7232c99	368	rcu_read_unlock();
eb9c7ebe PM	369	#endif
	370	}
	371
1da177e4	372	#else /* !CONFIG_NETFILTER */
008027c3 AB	373	static inline int
	374	NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net net, struct sock sk,
	375	struct sk_buff skb, struct net_device in, struct net_device *out,
	376	int (okfn)(struct net , struct sock , struct sk_buff ),
	377	bool cond)
	378	{
	379	return okfn(net, sk, skb);
	380	}
	381
	382	static inline int
	383	NF_HOOK(uint8_t pf, unsigned int hook, struct net net, struct sock sk,
	384	struct sk_buff skb, struct net_device in, struct net_device *out,
	385	int (okfn)(struct net , struct sock , struct sk_buff ))
	386	{
	387	return okfn(net, sk, skb);
	388	}
	389
17266ee9 EC	390	static inline void
	391	NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net net, struct sock sk,
	392	struct list_head head, struct net_device in, struct net_device *out,
	393	int (okfn)(struct net , struct sock , struct sk_buff ))
	394	{
	395	/* nothing to do */
	396	}
	397
29a26a56 EB	398	static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
	399	struct sock sk, struct sk_buff skb,
	400	struct net_device indev, struct net_device outdev,
0c4b51f0	401	int (okfn)(struct net , struct sock , struct sk_buff ))
f53b61d8	402	{
9c92d348	403	return 1;
f53b61d8	404	}
f53b61d8	405	struct flowi;
eb9c7ebe	406	static inline void
76108cea JE	407	nf_nat_decode_session(struct sk_buff skb, struct flowi fl, u_int8_t family)
	408	{
	409	}
1da177e4 LT	410	#endif /CONFIG_NETFILTER/
1da177e4 LT	411
5f79e0f9	412	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
62da9865 DB	413	#include <linux/netfilter/nf_conntrack_zones_common.h>
62da9865 DB	414
312a0c16	415	extern void (ip_ct_attach)(struct sk_buff , const struct sk_buff *) __rcu;
a0f4ecf3	416	void nf_ct_attach(struct sk_buff , const struct sk_buff );
b60a6040 THJ	417	struct nf_conntrack_tuple;
	418	bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
	419	const struct sk_buff *skb);
b7bd1809 PNA	420	#else
b7bd1809 PNA	421	static inline void nf_ct_attach(struct sk_buff new, struct sk_buff skb) {}
b60a6040 THJ	422	struct nf_conntrack_tuple;
	423	static inline bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
	424	const struct sk_buff *skb)
	425	{
	426	return false;
	427	}
b7bd1809	428	#endif
9cb01766 PNA	429
9cb01766 PNA	430	struct nf_conn;
41d73ec0	431	enum ip_conntrack_info;
1f4b2439 PNA	432
1f4b2439 PNA	433	struct nf_ct_hook {
368982cd	434	int (update)(struct net net, struct sk_buff *skb);
1f4b2439	435	void (destroy)(struct nf_conntrack );
b60a6040 THJ	436	bool (get_tuple_skb)(struct nf_conntrack_tuple ,
b60a6040 THJ	437	const struct sk_buff *);
1f4b2439 PNA	438	};
	439	extern struct nf_ct_hook __rcu *nf_ct_hook;
	440
9cb01766 PNA	441	struct nlattr;
9cb01766 PNA	442
a4b4766c	443	struct nfnl_ct_hook {
224a0597	444	struct nf_conn (get_ct)(const struct sk_buff *skb,
b7bd1809	445	enum ip_conntrack_info *ctinfo);
9cb01766	446	size_t (build_size)(const struct nf_conn ct);
b7bd1809 PNA	447	int (build)(struct sk_buff skb, struct nf_conn *ct,
	448	enum ip_conntrack_info ctinfo,
	449	u_int16_t ct_attr, u_int16_t ct_info_attr);
9cb01766	450	int (parse)(const struct nlattr attr, struct nf_conn *ct);
bd077937 PNA	451	int (attach_expect)(const struct nlattr attr, struct nf_conn *ct,
bd077937 PNA	452	u32 portid, u32 report);
8c88f87c	453	void (seq_adjust)(struct sk_buff skb, struct nf_conn *ct,
41d73ec0	454	enum ip_conntrack_info ctinfo, s32 off);
9cb01766	455	};
a4b4766c	456	extern struct nfnl_ct_hook __rcu *nfnl_ct_hook;
5f79e0f9	457
e7c8899f FW	458	/**
	459	* nf_skb_duplicated - TEE target has sent a packet
	460	*
	461	* When a xtables target sends a packet, the OUTPUT and POSTROUTING
	462	* hooks are traversed again, i.e. nft and xtables are invoked recursively.
	463	*
	464	* This is used by xtables TEE target to prevent the duplicated skb from
	465	* being duplicated again.
	466	*/
	467	DECLARE_PER_CPU(bool, nf_skb_duplicated);
	468
1da177e4	469	#endif /__LINUX_NETFILTER_H/