/*-
 * 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;
};

__BEGIN_DECLS

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 *);

__END_DECLS

#endif /* !__LIBISCSIUTIL_H__ */