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

#define RDS_TCP_PORT    16385

/* per-network namespace private data for this module */
struct rds_tcp_net {
        /* serialize "rds_tcp_accept_one" with "rds_tcp_accept_lock"
         * to protect "rds_tcp_accepted_sock"
         */
        struct mutex            rds_tcp_accept_lock;
        struct socket           *rds_tcp_listen_sock;
        struct socket           *rds_tcp_accepted_sock;
        struct work_struct      rds_tcp_accept_w;
        struct ctl_table_header *rds_tcp_sysctl;
        const struct ctl_table  *ctl_table;
        int                     sndbuf_size;
        int                     rcvbuf_size;
};

struct rds_tcp_incoming {
        struct rds_incoming     ti_inc;
        struct sk_buff_head     ti_skb_list;
};

struct rds_tcp_connection {

        struct list_head        t_tcp_node;
        bool                    t_tcp_node_detached;
        struct rds_conn_path    *t_cpath;
        /* t_conn_path_lock synchronizes the connection establishment between
         * rds_tcp_accept_one and rds_tcp_conn_path_connect
         */
        struct mutex            t_conn_path_lock;
        struct socket           *t_sock;
        u32                     t_client_port_group;
        struct rds_tcp_net      *t_rtn;
        void                    *t_orig_write_space;
        void                    *t_orig_data_ready;
        void                    *t_orig_state_change;

        struct rds_tcp_incoming *t_tinc;
        size_t                  t_tinc_hdr_rem;
        size_t                  t_tinc_data_rem;

        /* XXX error report? */
        struct work_struct      t_conn_w;
        struct work_struct      t_send_w;
        struct work_struct      t_down_w;
        struct work_struct      t_recv_w;

        /* for info exporting only */
        struct list_head        t_list_item;
        u32                     t_last_sent_nxt;
        u32                     t_last_expected_una;
        u32                     t_last_seen_una;

        /* for rds_tcp_conn_path_shutdown */
        wait_queue_head_t       t_recv_done_waitq;
};

struct rds_tcp_statistics {
        uint64_t        s_tcp_data_ready_calls;
        uint64_t        s_tcp_write_space_calls;
        uint64_t        s_tcp_sndbuf_full;
        uint64_t        s_tcp_connect_raced;
        uint64_t        s_tcp_listen_closed_stale;
};

/* tcp.c */
extern int rds_tcp_netid;
bool rds_tcp_tune(struct socket *sock);
void rds_tcp_set_callbacks(struct socket *sock, struct rds_conn_path *cp);
void rds_tcp_reset_callbacks(struct socket *sock, struct rds_conn_path *cp);
void rds_tcp_restore_callbacks(struct socket *sock,
                               struct rds_tcp_connection *tc);
u32 rds_tcp_write_seq(struct rds_tcp_connection *tc);
u32 rds_tcp_snd_una(struct rds_tcp_connection *tc);
extern struct rds_transport rds_tcp_transport;
void rds_tcp_accept_work(struct rds_tcp_net *rtn);
int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr,
                        __u32 scope_id);
/* tcp_connect.c */
int rds_tcp_conn_path_connect(struct rds_conn_path *cp);
void rds_tcp_conn_path_shutdown(struct rds_conn_path *conn);
void rds_tcp_state_change(struct sock *sk);

/* tcp_listen.c */
struct socket *rds_tcp_listen_init(struct net *net, bool isv6);
void rds_tcp_listen_stop(struct socket *sock, struct work_struct *acceptor);
void rds_tcp_listen_data_ready(struct sock *sk);
void rds_tcp_conn_slots_available(struct rds_connection *conn, bool fan_out);
int rds_tcp_accept_one(struct rds_tcp_net *rtn);
void rds_tcp_keepalive(struct socket *sock);
void *rds_tcp_listen_sock_def_readable(struct net *net);

/* tcp_recv.c */
int rds_tcp_recv_init(void);
void rds_tcp_recv_exit(void);
void rds_tcp_data_ready(struct sock *sk);
int rds_tcp_recv_path(struct rds_conn_path *cp);
void rds_tcp_inc_free(struct rds_incoming *inc);
int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);

/* tcp_send.c */
void rds_tcp_xmit_path_prepare(struct rds_conn_path *cp);
void rds_tcp_xmit_path_complete(struct rds_conn_path *cp);
int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm,
                 unsigned int hdr_off, unsigned int sg, unsigned int off);
int rds_tcp_is_acked(struct rds_message *rm, uint64_t ack);
void rds_tcp_write_space(struct sock *sk);

/* tcp_stats.c */
DECLARE_PER_CPU(struct rds_tcp_statistics, rds_tcp_stats);
#define rds_tcp_stats_inc(member) rds_stats_inc_which(rds_tcp_stats, member)
unsigned int rds_tcp_stats_info_copy(struct rds_info_iterator *iter,
                                     unsigned int avail);

#endif