/* SPDX-License-Identifier: GPL-2.0 */
/*
 * This header is used to share core functionality between the
 * standalone connection tracking module, and the compatibility layer's use
 * of connection tracking.
 *
 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
 *      - generalize L3 protocol dependent part.
 *
 * Derived from include/linux/netfiter_ipv4/ip_conntrack_core.h
 */

#ifndef _NF_CONNTRACK_CORE_H
#define _NF_CONNTRACK_CORE_H

#include <linux/netfilter.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_l4proto.h>

/* This header is used to share core functionality between the
   standalone connection tracking module, and the compatibility layer's use
   of connection tracking. */

unsigned int nf_conntrack_in(struct sk_buff *skb,
                             const struct nf_hook_state *state);

int nf_conntrack_init_net(struct net *net);
void nf_conntrack_cleanup_net(struct net *net);
void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list);

void nf_conntrack_proto_pernet_init(struct net *net);

int nf_conntrack_proto_init(void);
void nf_conntrack_proto_fini(void);

int nf_conntrack_init_start(void);
void nf_conntrack_cleanup_start(void);

void nf_conntrack_init_end(void);
void nf_conntrack_cleanup_end(void);

bool nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
                        const struct nf_conntrack_tuple *orig);

/* Find a connection corresponding to a tuple. */
struct nf_conntrack_tuple_hash *
nf_conntrack_find_get(struct net *net,
                      const struct nf_conntrack_zone *zone,
                      const struct nf_conntrack_tuple *tuple);

int __nf_conntrack_confirm(struct sk_buff *skb);

/* Confirm a connection: returns NF_DROP if packet must be dropped. */
static inline int nf_conntrack_confirm(struct sk_buff *skb)
{
        struct nf_conn *ct = (struct nf_conn *)skb_nfct(skb);
        int ret = NF_ACCEPT;

        if (ct) {
                if (!nf_ct_is_confirmed(ct)) {
                        ret = __nf_conntrack_confirm(skb);

                        if (ret == NF_ACCEPT)
                                ct = (struct nf_conn *)skb_nfct(skb);
                }

                if (ret == NF_ACCEPT && nf_ct_ecache_exist(ct))
                        nf_ct_deliver_cached_events(ct);
        }
        return ret;
}

unsigned int nf_confirm(void *priv, struct sk_buff *skb, const struct nf_hook_state *state);

void print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,
                 const struct nf_conntrack_l4proto *proto);

#define CONNTRACK_LOCKS 1024

extern spinlock_t nf_conntrack_locks[CONNTRACK_LOCKS];
void nf_conntrack_lock(spinlock_t *lock);

extern spinlock_t nf_conntrack_expect_lock;

static inline void lockdep_nfct_expect_lock_held(void)
{
        lockdep_assert_held(&nf_conntrack_expect_lock);
}

/* ctnetlink code shared by both ctnetlink and nf_conntrack_bpf */

static inline void __nf_ct_set_timeout(struct nf_conn *ct, u64 timeout)
{
        if (timeout > INT_MAX)
                timeout = INT_MAX;

        if (nf_ct_is_confirmed(ct))
                WRITE_ONCE(ct->timeout, nfct_time_stamp + (u32)timeout);
        else
                ct->timeout = (u32)timeout;
}

int __nf_ct_change_timeout(struct nf_conn *ct, u64 cta_timeout);
void __nf_ct_change_status(struct nf_conn *ct, unsigned long on, unsigned long off);
int nf_ct_change_status_common(struct nf_conn *ct, unsigned int status);

#endif /* _NF_CONNTRACK_CORE_H */