/* 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 {
  	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

  	 */
  };

  #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;

  #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 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);

  };
  
  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)

  {

  #if IS_ENABLED(CONFIG_NF_NAT)

  	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>

  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*/