/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * INET         An implementation of the TCP/IP protocol suite for the LINUX
 *              operating system.  INET is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              Definitions for a generic INET TIMEWAIT sock
 *
 *              From code originally in net/tcp.h
 */
#ifndef _INET_TIMEWAIT_SOCK_
#define _INET_TIMEWAIT_SOCK_

#include <linux/list.h>
#include <linux/timer.h>
#include <linux/types.h>
#include <linux/workqueue.h>

#include <net/inet_sock.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <net/timewait_sock.h>

#include <linux/atomic.h>

struct inet_bind_bucket;

/*
 * This is a TIME_WAIT sock. It works around the memory consumption
 * problems of sockets in such a state on heavily loaded servers, but
 * without violating the protocol specification.
 */
struct inet_timewait_sock {
        /*
         * Now struct sock also uses sock_common, so please just
         * don't add nothing before this first member (__tw_common) --acme
         */
        struct sock_common      __tw_common;
#define tw_family               __tw_common.skc_family
#define tw_state                __tw_common.skc_state
#define tw_reuse                __tw_common.skc_reuse
#define tw_reuseport            __tw_common.skc_reuseport
#define tw_ipv6only             __tw_common.skc_ipv6only
#define tw_bound_dev_if         __tw_common.skc_bound_dev_if
#define tw_node                 __tw_common.skc_nulls_node
#define tw_bind_node            __tw_common.skc_bind_node
#define tw_refcnt               __tw_common.skc_refcnt
#define tw_tx_queue_mapping     __tw_common.skc_tx_queue_mapping
#define tw_rx_queue_mapping     __tw_common.skc_rx_queue_mapping
#define tw_hash                 __tw_common.skc_hash
#define tw_prot                 __tw_common.skc_prot
#define tw_net                  __tw_common.skc_net
#define tw_daddr                __tw_common.skc_daddr
#define tw_v6_daddr             __tw_common.skc_v6_daddr
#define tw_rcv_saddr            __tw_common.skc_rcv_saddr
#define tw_v6_rcv_saddr         __tw_common.skc_v6_rcv_saddr
#define tw_dport                __tw_common.skc_dport
#define tw_num                  __tw_common.skc_num
#define tw_cookie               __tw_common.skc_cookie
#define tw_dr                   __tw_common.skc_tw_dr

        __u32                   tw_mark;
        unsigned char           tw_substate;
        unsigned char           tw_rcv_wscale;

        /* Socket demultiplex comparisons on incoming packets. */
        /* these three are in inet_sock */
        __be16                  tw_sport;
        /* And these are ours. */
        unsigned int            tw_transparent  : 1,
                                tw_flowlabel    : 20,
                                tw_usec_ts      : 1,
                                tw_connect_bind : 1,
                                tw_pad          : 1,    /* 1 bit hole */
                                tw_tos          : 8;
        u32                     tw_txhash;
        u32                     tw_priority;
        /**
         * @tw_reuse_stamp: Time of entry into %TCP_TIME_WAIT state in msec.
         */
        u32                     tw_entry_stamp;
        struct timer_list       tw_timer;
        struct inet_bind_bucket *tw_tb;
        struct inet_bind2_bucket        *tw_tb2;
#if IS_ENABLED(CONFIG_INET_PSP)
        struct psp_assoc __rcu    *psp_assoc;
#endif
#ifdef CONFIG_SOCK_VALIDATE_XMIT
        struct sk_buff*         (*tw_validate_xmit_skb)(struct sock *sk,
                                                        struct net_device *dev,
                                                        struct sk_buff *skb);
#endif
};
#define tw_tclass tw_tos

static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
{
        return (struct inet_timewait_sock *)sk;
}

void inet_twsk_free(struct inet_timewait_sock *tw);
void inet_twsk_put(struct inet_timewait_sock *tw);

void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
                           struct inet_hashinfo *hashinfo);

struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
                                           struct inet_timewait_death_row *dr,
                                           const int state);

void inet_twsk_hashdance_schedule(struct inet_timewait_sock *tw,
                                  struct sock *sk,
                                  struct inet_hashinfo *hashinfo,
                                  int timeo);

void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo,
                          bool rearm);

static inline void inet_twsk_reschedule(struct inet_timewait_sock *tw, int timeo)
{
        __inet_twsk_schedule(tw, timeo, true);
}

void inet_twsk_deschedule_put(struct inet_timewait_sock *tw);

void inet_twsk_purge(struct inet_hashinfo *hashinfo);

static inline
struct net *twsk_net(const struct inet_timewait_sock *twsk)
{
        return read_pnet(&twsk->tw_net);
}

static inline
void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
{
        write_pnet(&twsk->tw_net, net);
}
#endif  /* _INET_TIMEWAIT_SOCK_ */