[linux-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 <linux/sockptr.h>
#include <net/net_namespace.h>

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)
{
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
	const unsigned long *ul1 = (const unsigned long *)a1;
	const unsigned long *ul2 = (const unsigned long *)a2;

	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
#else
	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];
#endif
}

static inline void nf_inet_addr_mask(const union nf_inet_addr *a1,
				     union nf_inet_addr *result,
				     const union nf_inet_addr *mask)
{
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
	const unsigned long *ua = (const unsigned long *)a1;
	unsigned long *ur = (unsigned long *)result;
	const unsigned long *um = (const unsigned long *)mask;

	ur[0] = ua[0] & um[0];
	ur[1] = ua[1] & um[1];
#else
	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];
#endif
}

int netfilter_init(void);

struct sk_buff;

struct nf_hook_ops;

struct sock;

struct nf_hook_state {
	u8 hook;
	u8 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);
enum nf_hook_ops_type {
	NF_HOOK_OP_UNDEFINED,
	NF_HOOK_OP_NF_TABLES,
	NF_HOOK_OP_BPF,
};

struct nf_hook_ops {
	/* User fills in from here down. */
	nf_hookfn		*hook;
	struct net_device	*dev;
	void			*priv;
	u8			pf;
	enum nf_hook_ops_type	hook_ops_type:8;
	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
	 */
};

#ifdef CONFIG_NETFILTER
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, sockptr_t arg,
		   unsigned int len);
	int get_optmin;
	int get_optmax;
	int (*get)(struct sock *sk, int optval, void __user *user, int *len);
	/* 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 CONFIG_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);

void nf_hook_slow_list(struct list_head *head, struct nf_hook_state *state,
		       const struct nf_hook_entries *e);
/**
 *	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 CONFIG_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
		if (WARN_ON_ONCE(hook >= ARRAY_SIZE(net->nf.hooks_arp)))
			break;
		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;
	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 nf_hook_entries *hook_head = NULL;

#ifdef CONFIG_JUMP_LABEL
	if (__builtin_constant_p(pf) &&
	    __builtin_constant_p(hook) &&
	    !static_key_false(&nf_hooks_needed[pf][hook]))
		return;
#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;
	default:
		WARN_ON_ONCE(1);
		break;
	}

	if (hook_head) {
		struct nf_hook_state state;

		nf_hook_state_init(&state, hook, pf, in, out, sk, net, okfn);

		nf_hook_slow_list(head, &state, hook_head);
	}
	rcu_read_unlock();
}

/* Call setsockopt() */
int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, sockptr_t opt,
		  unsigned int len);
int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
		  int *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);
	void (*remove_nat_bysrc)(struct nf_conn *ct);
};

extern const 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)
{
#if IS_ENABLED(CONFIG_NF_NAT)
	const 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 IS_ENABLED(CONFIG_NF_CONNTRACK)
#include <linux/netfilter/nf_conntrack_zones_common.h>

void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
void nf_ct_set_closing(struct nf_conntrack *nfct);
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) {}
static inline void nf_ct_set_closing(struct nf_conntrack *nfct) {}
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 *);
	void (*attach)(struct sk_buff *nskb, const struct sk_buff *skb);
	void (*set_closing)(struct nf_conntrack *nfct);
};
extern const struct nf_ct_hook __rcu *nf_ct_hook;

struct nlattr;

struct nfnl_ct_hook {
	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 const 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);

/**
 * Contains bitmask of ctnetlink event subscribers, if any.
 * Can't be pernet due to NETLINK_LISTEN_ALL_NSID setsockopt flag.
 */
extern u8 nf_ctnetlink_has_listener;
#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	15	#include <linux/netdevice.h>
c2f12630	16	#include <linux/sockptr.h>
085db2c0	17	#include <net/net_namespace.h>
a263653e	18
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	{
01902f8c LR	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;
	30
	31	return ((ul1[0] ^ ul2[0]) \| (ul1[1] ^ ul2[1])) == 0UL;
	32	#else
b8beedd2 PM	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];
01902f8c	37	#endif
b8beedd2 PM	38	}
b8beedd2 PM	39
efdedd54 DF	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)
	43	{
522e4077 LR	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;
	48
	49	ur[0] = ua[0] & um[0];
	50	ur[1] = ua[1] & um[1];
	51	#else
efdedd54 DF	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];
522e4077	56	#endif
efdedd54 DF	57	}
efdedd54 DF	58
a0f4ecf3	59	int netfilter_init(void);
1da177e4	60
1da177e4	61	struct sk_buff;
1da177e4	62
795aa6ef	63	struct nf_hook_ops;
cfdfab31	64
1c984f8a DM	65	struct sock;
1c984f8a DM	66
cfdfab31	67	struct nf_hook_state {
6802db48 FW	68	u8 hook;
6802db48 FW	69	u8 pf;
cfdfab31 DM	70	struct net_device *in;
cfdfab31 DM	71	struct net_device *out;
1c984f8a	72	struct sock *sk;
b11b1f65	73	struct net *net;
0c4b51f0	74	int (okfn)(struct net , struct sock , struct sk_buff );
cfdfab31 DM	75	};
cfdfab31 DM	76
e3b37f11 AC	77	typedef unsigned int nf_hookfn(void *priv,
	78	struct sk_buff *skb,
	79	const struct nf_hook_state *state);
7b4b2fa3 FW	80	enum nf_hook_ops_type {
	81	NF_HOOK_OP_UNDEFINED,
	82	NF_HOOK_OP_NF_TABLES,
84601d6e	83	NF_HOOK_OP_BPF,
7b4b2fa3 FW	84	};
7b4b2fa3 FW	85
e3b37f11	86	struct nf_hook_ops {
e3b37f11 AC	87	/* User fills in from here down. */
	88	nf_hookfn *hook;
	89	struct net_device *dev;
	90	void *priv;
7b4b2fa3 FW	91	u8 pf;
7b4b2fa3 FW	92	enum nf_hook_ops_type hook_ops_type:8;
e3b37f11 AC	93	unsigned int hooknum;
	94	/* Hooks are ordered in ascending priority. */
	95	int priority;
	96	};
	97
	98	struct nf_hook_entry {
d415b9eb AC	99	nf_hookfn *hook;
d415b9eb AC	100	void *priv;
e3b37f11 AC	101	};
e3b37f11 AC	102
8c873e21 FW	103	struct nf_hook_entries_rcu_head {
	104	struct rcu_head head;
	105	void *allocation;
	106	};
	107
960632ec AC	108	struct nf_hook_entries {
	109	u16 num_hook_entries;
	110	/* padding */
	111	struct nf_hook_entry hooks[];
	112
8c873e21 FW	113	/* trailer: pointers to original orig_ops of each hook,
	114	* followed by rcu_head and scratch space used for freeing
	115	* the structure via call_rcu.
960632ec	116	*
8c873e21 FW	117	* This is not part of struct nf_hook_entry since its only
8c873e21 FW	118	* needed in slow path (hook register/unregister):
960632ec	119	* const struct nf_hook_ops *orig_ops[]
8c873e21 FW	120	*
	121	* For the same reason, we store this at end -- its
	122	* only needed when a hook is deleted, not during
	123	* packet path processing:
	124	* struct nf_hook_entries_rcu_head head
960632ec AC	125	*/
960632ec AC	126	};
0aa8c57a	127
f19438bd	128	#ifdef CONFIG_NETFILTER
960632ec	129	static inline struct nf_hook_ops *nf_hook_entries_get_hook_ops(const struct nf_hook_entries e)
0aa8c57a	130	{
960632ec AC	131	unsigned int n = e->num_hook_entries;
	132	const void *hook_end;
	133
	134	hook_end = &e->hooks[n]; /* this is past ->hooks[]! */
	135
	136	return (struct nf_hook_ops **)hook_end;
0aa8c57a AC	137	}
	138
	139	static inline int
	140	nf_hook_entry_hookfn(const struct nf_hook_entry entry, struct sk_buff skb,
	141	struct nf_hook_state *state)
	142	{
d415b9eb	143	return entry->hook(entry->priv, skb, state);
0aa8c57a AC	144	}
0aa8c57a AC	145
107a9f4d DM	146	static inline void nf_hook_state_init(struct nf_hook_state *p,
107a9f4d DM	147	unsigned int hook,
1610a73c	148	u_int8_t pf,
107a9f4d DM	149	struct net_device *indev,
107a9f4d DM	150	struct net_device *outdev,
1c984f8a	151	struct sock *sk,
b11b1f65	152	struct net *net,
0c4b51f0	153	int (okfn)(struct net , struct sock , struct sk_buff ))
107a9f4d DM	154	{
107a9f4d DM	155	p->hook = hook;
107a9f4d DM	156	p->pf = pf;
	157	p->in = indev;
	158	p->out = outdev;
1c984f8a	159	p->sk = sk;
b11b1f65	160	p->net = net;
107a9f4d DM	161	p->okfn = okfn;
	162	}
	163
1da177e4	164
1da177e4	165
d94d9fee	166	struct nf_sockopt_ops {
1da177e4 LT	167	struct list_head list;
1da177e4 LT	168
76108cea	169	u_int8_t pf;
1da177e4 LT	170
	171	/* Non-inclusive ranges: use 0/0/NULL to never get called. */
	172	int set_optmin;
	173	int set_optmax;
c2f12630 CH	174	int (set)(struct sock sk, int optval, sockptr_t arg,
c2f12630 CH	175	unsigned int len);
1da177e4 LT	176	int get_optmin;
	177	int get_optmax;
	178	int (get)(struct sock sk, int optval, void __user user, int len);
16fcec35 NH	179	/* Use the module struct to lock set/get code in place */
16fcec35 NH	180	struct module *owner;
1da177e4 LT	181	};
1da177e4 LT	182
1da177e4	183	/* Function to register/unregister hook points. */
085db2c0 EB	184	int nf_register_net_hook(struct net net, const struct nf_hook_ops ops);
	185	void nf_unregister_net_hook(struct net net, const struct nf_hook_ops ops);
	186	int nf_register_net_hooks(struct net net, const struct nf_hook_ops reg,
	187	unsigned int n);
	188	void nf_unregister_net_hooks(struct net net, const struct nf_hook_ops reg,
	189	unsigned int n);
	190
1da177e4 LT	191	/* Functions to register get/setsockopt ranges (non-inclusive). You
	192	need to check permissions yourself! */
	193	int nf_register_sockopt(struct nf_sockopt_ops *reg);
	194	void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
	195
e9666d10	196	#ifdef CONFIG_JUMP_LABEL
c5905afb	197	extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
a2d7ec58 ED	198	#endif
a2d7ec58 ED	199
01886bd9	200	int nf_hook_slow(struct sk_buff skb, struct nf_hook_state state,
960632ec	201	const struct nf_hook_entries *e, unsigned int i);
16a6677f	202
ca58fbe0 FW	203	void nf_hook_slow_list(struct list_head head, struct nf_hook_state state,
ca58fbe0 FW	204	const struct nf_hook_entries *e);
16a6677f	205	/**
1610a73c	206	* nf_hook - call a netfilter hook
b8d0aad0	207	*
16a6677f PM	208	* Returns 1 if the hook has allowed the packet to pass. The function
	209	* okfn must be invoked by the caller in this case. Any other return
	210	* value indicates the packet has been consumed by the hook.
	211	*/
1610a73c PNA	212	static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
	213	struct sock sk, struct sk_buff skb,
	214	struct net_device indev, struct net_device outdev,
	215	int (okfn)(struct net , struct sock , struct sk_buff ))
16a6677f	216	{
b0f38338	217	struct nf_hook_entries *hook_head = NULL;
e3b37f11	218	int ret = 1;
af4610c3	219
e9666d10	220	#ifdef CONFIG_JUMP_LABEL
af4610c3 FW	221	if (__builtin_constant_p(pf) &&
	222	__builtin_constant_p(hook) &&
	223	!static_key_false(&nf_hooks_needed[pf][hook]))
	224	return 1;
	225	#endif
	226
e3b37f11	227	rcu_read_lock();
b0f38338 FW	228	switch (pf) {
	229	case NFPROTO_IPV4:
	230	hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
	231	break;
	232	case NFPROTO_IPV6:
	233	hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
	234	break;
	235	case NFPROTO_ARP:
2a95183a	236	#ifdef CONFIG_NETFILTER_FAMILY_ARP
421c119f FW	237	if (WARN_ON_ONCE(hook >= ARRAY_SIZE(net->nf.hooks_arp)))
421c119f FW	238	break;
b0f38338	239	hook_head = rcu_dereference(net->nf.hooks_arp[hook]);
2a95183a	240	#endif
b0f38338 FW	241	break;
b0f38338 FW	242	case NFPROTO_BRIDGE:
2a95183a	243	#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
b0f38338	244	hook_head = rcu_dereference(net->nf.hooks_bridge[hook]);
2a95183a	245	#endif
b0f38338	246	break;
b0f38338 FW	247	default:
	248	WARN_ON_ONCE(1);
	249	break;
	250	}
	251
e3b37f11	252	if (hook_head) {
107a9f4d	253	struct nf_hook_state state;
cfdfab31	254
01886bd9	255	nf_hook_state_init(&state, hook, pf, indev, outdev,
1610a73c	256	sk, net, okfn);
fe72926b	257
960632ec	258	ret = nf_hook_slow(skb, &state, hook_head, 0);
cfdfab31	259	}
e3b37f11 AC	260	rcu_read_unlock();
	261
	262	return ret;
16a6677f PM	263	}
16a6677f PM	264
1da177e4 LT	265	/* Activate hook; either okfn or kfree_skb called, unless a hook
	266	returns NF_STOLEN (in which case, it's up to the hook to deal with
	267	the consequences).
	268
	269	Returns -ERRNO if packet dropped. Zero means queued, stolen or
	270	accepted.
	271	*/
	272
	273	/* RR:
	274	> I don't want nf_hook to return anything because people might forget
	275	> about async and trust the return value to mean "packet was ok".
	276
	277	AK:
	278	Just document it clearly, then you can expect some sense from kernel
	279	coders :)
	280	*/
	281
2249065f	282	static inline int
29a26a56	283	NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net net, struct sock sk,
7026b1dd	284	struct sk_buff skb, struct net_device in, struct net_device *out,
0c4b51f0 EB	285	int (okfn)(struct net , struct sock , struct sk_buff ),
0c4b51f0 EB	286	bool cond)
2249065f	287	{
4bac6b18 PM	288	int ret;
	289
	290	if (!cond \|\|
1610a73c	291	((ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn)) == 1))
0c4b51f0	292	ret = okfn(net, sk, skb);
2249065f JE	293	return ret;
2249065f JE	294	}
1da177e4	295
2249065f	296	static inline int
29a26a56	297	NF_HOOK(uint8_t pf, unsigned int hook, struct net net, struct sock sk, struct sk_buff *skb,
2249065f	298	struct net_device in, struct net_device out,
0c4b51f0	299	int (okfn)(struct net , struct sock , struct sk_buff ))
2249065f	300	{
1610a73c PNA	301	int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn);
	302	if (ret == 1)
	303	ret = okfn(net, sk, skb);
	304	return ret;
2249065f	305	}
1da177e4	306
17266ee9 EC	307	static inline void
	308	NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net net, struct sock sk,
	309	struct list_head head, struct net_device in, struct net_device *out,
	310	int (okfn)(struct net , struct sock , struct sk_buff ))
	311	{
ca58fbe0 FW	312	struct nf_hook_entries *hook_head = NULL;
	313
	314	#ifdef CONFIG_JUMP_LABEL
	315	if (__builtin_constant_p(pf) &&
	316	__builtin_constant_p(hook) &&
	317	!static_key_false(&nf_hooks_needed[pf][hook]))
	318	return;
	319	#endif
	320
	321	rcu_read_lock();
	322	switch (pf) {
	323	case NFPROTO_IPV4:
	324	hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
	325	break;
	326	case NFPROTO_IPV6:
	327	hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
	328	break;
	329	default:
	330	WARN_ON_ONCE(1);
	331	break;
17266ee9	332	}
ca58fbe0 FW	333
	334	if (hook_head) {
	335	struct nf_hook_state state;
	336
	337	nf_hook_state_init(&state, hook, pf, in, out, sk, net, okfn);
	338
	339	nf_hook_slow_list(head, &state, hook_head);
	340	}
	341	rcu_read_unlock();
17266ee9 EC	342	}
17266ee9 EC	343
1da177e4	344	/* Call setsockopt() */
c2f12630	345	int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, sockptr_t opt,
b7058842	346	unsigned int len);
76108cea	347	int nf_getsockopt(struct sock sk, u_int8_t pf, int optval, char __user opt,
1da177e4	348	int *len);
3fdadf7d	349
1841a4c7	350	struct flowi;
02f014d8	351	struct nf_queue_entry;
c01cd429	352
ef71fe27 PNA	353	__sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,
	354	unsigned int dataoff, u_int8_t protocol,
	355	unsigned short family);
422c346f	356
f7dcbe2f PNA	357	__sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
	358	unsigned int dataoff, unsigned int len,
	359	u_int8_t protocol, unsigned short family);
3f87c08c PNA	360	int nf_route(struct net net, struct dst_entry dst, struct flowi fl,
3f87c08c PNA	361	bool strict, unsigned short family);
ce388f45	362	int nf_reroute(struct sk_buff skb, struct nf_queue_entry entry);
d63a6507	363
eb9c7ebe	364	#include <net/flow.h>
2c205dd3 PNA	365
	366	struct nf_conn;
	367	enum nf_nat_manip_type;
	368	struct nlattr;
368982cd	369	enum ip_conntrack_dir;
2c205dd3 PNA	370
	371	struct nf_nat_hook {
	372	int (parse_nat_setup)(struct nf_conn ct, enum nf_nat_manip_type manip,
	373	const struct nlattr *attr);
	374	void (decode_session)(struct sk_buff skb, struct flowi *fl);
368982cd PNA	375	unsigned int (manip_pkt)(struct sk_buff skb, struct nf_conn *ct,
	376	enum nf_nat_manip_type mtype,
	377	enum ip_conntrack_dir dir);
1bc91a5d	378	void (remove_nat_bysrc)(struct nf_conn ct);
2c205dd3 PNA	379	};
2c205dd3 PNA	380
285c8a7a	381	extern const struct nf_nat_hook __rcu *nf_nat_hook;
eb9c7ebe PM	382
eb9c7ebe PM	383	static inline void
76108cea	384	nf_nat_decode_session(struct sk_buff skb, struct flowi fl, u_int8_t family)
eb9c7ebe	385	{
4806e975	386	#if IS_ENABLED(CONFIG_NF_NAT)
285c8a7a	387	const struct nf_nat_hook *nat_hook;
eb9c7ebe	388
c7232c99	389	rcu_read_lock();
2c205dd3	390	nat_hook = rcu_dereference(nf_nat_hook);
155fb5c5	391	if (nat_hook && nat_hook->decode_session)
2c205dd3	392	nat_hook->decode_session(skb, fl);
c7232c99	393	rcu_read_unlock();
eb9c7ebe PM	394	#endif
	395	}
	396
1da177e4	397	#else /* !CONFIG_NETFILTER */
008027c3 AB	398	static inline int
	399	NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net net, struct sock sk,
	400	struct sk_buff skb, struct net_device in, struct net_device *out,
	401	int (okfn)(struct net , struct sock , struct sk_buff ),
	402	bool cond)
	403	{
	404	return okfn(net, sk, skb);
	405	}
	406
	407	static inline int
	408	NF_HOOK(uint8_t pf, unsigned int hook, struct net net, struct sock sk,
	409	struct sk_buff skb, struct net_device in, struct net_device *out,
	410	int (okfn)(struct net , struct sock , struct sk_buff ))
	411	{
	412	return okfn(net, sk, skb);
	413	}
	414
17266ee9 EC	415	static inline void
	416	NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net net, struct sock sk,
	417	struct list_head head, struct net_device in, struct net_device *out,
	418	int (okfn)(struct net , struct sock , struct sk_buff ))
	419	{
	420	/* nothing to do */
	421	}
	422
29a26a56 EB	423	static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
	424	struct sock sk, struct sk_buff skb,
	425	struct net_device indev, struct net_device outdev,
0c4b51f0	426	int (okfn)(struct net , struct sock , struct sk_buff ))
f53b61d8	427	{
9c92d348	428	return 1;
f53b61d8	429	}
f53b61d8	430	struct flowi;
eb9c7ebe	431	static inline void
76108cea JE	432	nf_nat_decode_session(struct sk_buff skb, struct flowi fl, u_int8_t family)
	433	{
	434	}
1da177e4 LT	435	#endif /CONFIG_NETFILTER/
1da177e4 LT	436
25d7cbcd	437	#if IS_ENABLED(CONFIG_NF_CONNTRACK)
62da9865 DB	438	#include <linux/netfilter/nf_conntrack_zones_common.h>
62da9865 DB	439
a0f4ecf3	440	void nf_ct_attach(struct sk_buff , const struct sk_buff );
2954fe60	441	void nf_ct_set_closing(struct nf_conntrack *nfct);
b60a6040 THJ	442	struct nf_conntrack_tuple;
	443	bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
	444	const struct sk_buff *skb);
b7bd1809 PNA	445	#else
b7bd1809 PNA	446	static inline void nf_ct_attach(struct sk_buff new, struct sk_buff skb) {}
2954fe60	447	static inline void nf_ct_set_closing(struct nf_conntrack *nfct) {}
b60a6040 THJ	448	struct nf_conntrack_tuple;
	449	static inline bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
	450	const struct sk_buff *skb)
	451	{
	452	return false;
	453	}
b7bd1809	454	#endif
9cb01766 PNA	455
9cb01766 PNA	456	struct nf_conn;
41d73ec0	457	enum ip_conntrack_info;
1f4b2439 PNA	458
1f4b2439 PNA	459	struct nf_ct_hook {
368982cd	460	int (update)(struct net net, struct sk_buff *skb);
1f4b2439	461	void (destroy)(struct nf_conntrack );
b60a6040 THJ	462	bool (get_tuple_skb)(struct nf_conntrack_tuple ,
b60a6040 THJ	463	const struct sk_buff *);
3fce1649	464	void (attach)(struct sk_buff nskb, const struct sk_buff *skb);
2954fe60	465	void (set_closing)(struct nf_conntrack nfct);
1f4b2439	466	};
285c8a7a	467	extern const struct nf_ct_hook __rcu *nf_ct_hook;
1f4b2439	468
9cb01766 PNA	469	struct nlattr;
9cb01766 PNA	470
a4b4766c	471	struct nfnl_ct_hook {
9cb01766	472	size_t (build_size)(const struct nf_conn ct);
b7bd1809 PNA	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);
9cb01766	476	int (parse)(const struct nlattr attr, struct nf_conn *ct);
bd077937 PNA	477	int (attach_expect)(const struct nlattr attr, struct nf_conn *ct,
bd077937 PNA	478	u32 portid, u32 report);
8c88f87c	479	void (seq_adjust)(struct sk_buff skb, struct nf_conn *ct,
41d73ec0	480	enum ip_conntrack_info ctinfo, s32 off);
9cb01766	481	};
285c8a7a	482	extern const struct nfnl_ct_hook __rcu *nfnl_ct_hook;
5f79e0f9	483
e7c8899f FW	484	/**
	485	* nf_skb_duplicated - TEE target has sent a packet
	486	*
	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.
	489	*
	490	* This is used by xtables TEE target to prevent the duplicated skb from
	491	* being duplicated again.
	492	*/
	493	DECLARE_PER_CPU(bool, nf_skb_duplicated);
	494
fdf64911 FW	495	/**
	496	* Contains bitmask of ctnetlink event subscribers, if any.
	497	* Can't be pernet due to NETLINK_LISTEN_ALL_NSID setsockopt flag.
	498	*/
	499	extern u8 nf_ctnetlink_has_listener;
1da177e4	500	#endif /__LINUX_NETFILTER_H/