/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2012 The FreeBSD Foundation
 *
 * This software was developed by Edward Tomasz Napierala under sponsorship
 * from the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef __LIBISCSIUTIL_H__
#define	__LIBISCSIUTIL_H__

#include <sys/types.h>
#include <stdbool.h>

struct connection_ops;

#define	CONN_DIGEST_NONE		0
#define	CONN_DIGEST_CRC32C		1

struct connection {
	const struct connection_ops *conn_ops;
	int		conn_socket;
	uint8_t		conn_isid[6];
	uint16_t	conn_tsih;
	uint32_t	conn_cmdsn;
	uint32_t	conn_statsn;
	int		conn_header_digest;
	int		conn_data_digest;
	bool		conn_immediate_data;
	bool		conn_use_proxy;
	int		conn_max_recv_data_segment_length;
	int		conn_max_send_data_segment_length;
	int		conn_max_burst_length;
	int		conn_first_burst_length;
	int		conn_ping_timeout;
	int		conn_login_timeout;
};

struct pdu {
	struct connection *pdu_connection;
	struct iscsi_bhs *pdu_bhs;
	char		*pdu_data;
	size_t		pdu_data_len;
};

struct connection_ops {
	bool		(*timed_out)(void);
	void		(*pdu_receive_proxy)(struct pdu *);
	void		(*pdu_send_proxy)(struct pdu *);
	void		(*fail)(const struct connection *, const char *);
};

#define	KEYS_MAX		1024

struct keys {
	char		*keys_names[KEYS_MAX];
	char		*keys_values[KEYS_MAX];
};

#define	CHAP_CHALLENGE_LEN	1024
#define	CHAP_DIGEST_LEN		16 /* Equal to MD5 digest size. */

struct chap {
	unsigned char	chap_id;
	char		chap_challenge[CHAP_CHALLENGE_LEN];
	char		chap_response[CHAP_DIGEST_LEN];
};

struct rchap {
	char		*rchap_secret;
	unsigned char	rchap_id;
	void		*rchap_challenge;
	size_t		rchap_challenge_len;
};

struct chap		*chap_new(void);
char			*chap_get_id(const struct chap *chap);
char			*chap_get_challenge(const struct chap *chap);
int			chap_receive(struct chap *chap, const char *response);
int			chap_authenticate(struct chap *chap,
			    const char *secret);
void			chap_delete(struct chap *chap);

struct rchap		*rchap_new(const char *secret);
int			rchap_receive(struct rchap *rchap,
			    const char *id, const char *challenge);
char			*rchap_get_response(struct rchap *rchap);
void			rchap_delete(struct rchap *rchap);

struct keys		*keys_new(void);
void			keys_delete(struct keys *key);
void			keys_load(struct keys *keys, const char *data,
			    size_t len);
void			keys_save(struct keys *keys, char **datap,
			    size_t *lenp);
const char		*keys_find(struct keys *keys, const char *name);
void			keys_add(struct keys *keys,
			    const char *name, const char *value);
void			keys_add_int(struct keys *keys,
			    const char *name, int value);

static __inline void
keys_load_pdu(struct keys *keys, const struct pdu *pdu)
{
	keys_load(keys, pdu->pdu_data, pdu->pdu_data_len);
}

static __inline void
keys_save_pdu(struct keys *keys, struct pdu *pdu)
{
	keys_save(keys, &pdu->pdu_data, &pdu->pdu_data_len);
}

struct pdu		*pdu_new(struct connection *ic);
struct pdu		*pdu_new_response(struct pdu *request);
int			pdu_ahs_length(const struct pdu *pdu);
int			pdu_data_segment_length(const struct pdu *pdu);
void			pdu_set_data_segment_length(struct pdu *pdu,
			    uint32_t len);
void			pdu_receive(struct pdu *request);
void			pdu_send(struct pdu *response);
void			pdu_delete(struct pdu *ip);

void			text_send_request(struct connection *conn,
			    struct keys *request_keys);
struct keys *		text_read_response(struct connection *conn);
struct keys *		text_read_request(struct connection *conn,
			    struct pdu **requestp);
void			text_send_response(struct pdu *request,
			    struct keys *response_keys);

void			connection_init(struct connection *conn,
			    const struct connection_ops *ops, bool use_proxy);

bool			valid_iscsi_name(const char *name,
			    void (*warn_fn)(const char *, ...));

void			log_init(int level);
void			log_set_peer_name(const char *name);
void			log_set_peer_addr(const char *addr);
void			log_err(int, const char *, ...)
			    __dead2 __printflike(2, 3);
void			log_errc(int, int, const char *, ...)
			    __dead2 __printflike(3, 4);
void			log_errx(int, const char *, ...)
			    __dead2 __printflike(2, 3);
void			log_warn(const char *, ...) __printflike(1, 2);
void			log_warnc(int, const char *, ...)
			    __printflike(2, 3);
void			log_warnx(const char *, ...) __printflike(1, 2);
void			log_debugx(const char *, ...) __printflike(1, 2);

char			*checked_strdup(const char *);

#endif /* !__LIBISCSIUTIL_H__ */