/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * tcp.h
 *
 * Function prototypes
 *
 * Copyright (C) 2004 Oracle.  All rights reserved.
 */

#ifndef O2CLUSTER_TCP_H
#define O2CLUSTER_TCP_H

#include <linux/socket.h>
#ifdef __KERNEL__
#include <net/sock.h>
#include <linux/tcp.h>
#else
#include <sys/socket.h>
#endif
#include <linux/inet.h>
#include <linux/in.h>

struct o2net_msg
{
        __be16 magic;
        __be16 data_len;
        __be16 msg_type;
        __be16 pad1;
        __be32 sys_status;
        __be32 status;
        __be32 key;
        __be32 msg_num;
        __u8  buf[];
};

typedef int (o2net_msg_handler_func)(struct o2net_msg *msg, u32 len, void *data,
                                     void **ret_data);
typedef void (o2net_post_msg_handler_func)(int status, void *data,
                                           void *ret_data);

#define O2NET_MAX_PAYLOAD_BYTES  (4096 - sizeof(struct o2net_msg))

/* same as hb delay, we're waiting for another node to recognize our hb */
#define O2NET_RECONNECT_DELAY_MS_DEFAULT        2000

#define O2NET_KEEPALIVE_DELAY_MS_DEFAULT        2000
#define O2NET_IDLE_TIMEOUT_MS_DEFAULT           30000

#define O2NET_TCP_USER_TIMEOUT                  0x7fffffff

/* TODO: figure this out.... */
static inline int o2net_link_down(int err, struct socket *sock)
{
        if (sock) {
                if (sock->sk->sk_state != TCP_ESTABLISHED &&
                    sock->sk->sk_state != TCP_CLOSE_WAIT)
                        return 1;
        }

        if (err >= 0)
                return 0;
        switch (err) {
                /* ????????????????????????? */
                case -ERESTARTSYS:
                case -EBADF:
                /* When the server has died, an ICMP port unreachable
                 * message prompts ECONNREFUSED. */
                case -ECONNREFUSED:
                case -ENOTCONN:
                case -ECONNRESET:
                case -EPIPE:
                        return 1;
        }
        return 0;
}

enum {
        O2NET_DRIVER_UNINITED,
        O2NET_DRIVER_READY,
};

int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
                       u8 target_node, int *status);
int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *vec,
                           size_t veclen, u8 target_node, int *status);

int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
                           o2net_msg_handler_func *func, void *data,
                           o2net_post_msg_handler_func *post_func,
                           struct list_head *unreg_list);
void o2net_unregister_handler_list(struct list_head *list);

void o2net_fill_node_map(unsigned long *map, unsigned bytes);

struct o2nm_node;
int o2net_register_hb_callbacks(void);
void o2net_unregister_hb_callbacks(void);
int o2net_start_listening(struct o2nm_node *node);
void o2net_stop_listening(struct o2nm_node *node);
void o2net_disconnect_node(struct o2nm_node *node);
int o2net_num_connected_peers(void);

int o2net_init(void);
void o2net_exit(void);

struct o2net_send_tracking;
struct o2net_sock_container;

#ifdef CONFIG_DEBUG_FS
void o2net_debugfs_init(void);
void o2net_debugfs_exit(void);
void o2net_debug_add_nst(struct o2net_send_tracking *nst);
void o2net_debug_del_nst(struct o2net_send_tracking *nst);
void o2net_debug_add_sc(struct o2net_sock_container *sc);
void o2net_debug_del_sc(struct o2net_sock_container *sc);
#else
static inline void o2net_debugfs_init(void)
{
}
static inline void o2net_debugfs_exit(void)
{
}
static inline void o2net_debug_add_nst(struct o2net_send_tracking *nst)
{
}
static inline void o2net_debug_del_nst(struct o2net_send_tracking *nst)
{
}
static inline void o2net_debug_add_sc(struct o2net_sock_container *sc)
{
}
static inline void o2net_debug_del_sc(struct o2net_sock_container *sc)
{
}
#endif  /* CONFIG_DEBUG_FS */

#endif /* O2CLUSTER_TCP_H */