/* SPDX-License-Identifier: GPL-2.0-or-later */
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * 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[0];
};

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 */