/*
   Copyright (C) 2010 by Ronnie Sahlberg <ronniesahlberg@gmail.com>
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef CCAN_ISCSI_PRIVATE_H
#define CCAN_ISCSI_PRIVATE_H

#include <stdint.h>

#ifndef discard_const
#define discard_const(ptr) ((void *)((intptr_t)(ptr)))
#endif

struct iscsi_context {
       const char *initiator_name;
       const char *target_name;
       const char *alias;
       enum iscsi_session_type session_type;
       unsigned char isid[6];
       uint32_t itt;
       uint32_t cmdsn;
       uint32_t statsn;

       int fd;
       int is_connected;
       int is_loggedin;

       iscsi_command_cb connect_cb;
       void *connect_data;

       struct iscsi_pdu *outqueue;
       struct iscsi_pdu *waitpdu;

       int insize;
       int inpos;
       unsigned char *inbuf;
};

#define ISCSI_HEADER_SIZE			48

#define ISCSI_PDU_IMMEDIATE		       0x40

#define ISCSI_PDU_TEXT_FINAL		       0x80
#define ISCSI_PDU_TEXT_CONTINUE		       0x40

#define ISCSI_PDU_LOGIN_TRANSIT		       0x80
#define ISCSI_PDU_LOGIN_CONTINUE	       0x40
#define ISCSI_PDU_LOGIN_CSG_SECNEG	       0x00
#define ISCSI_PDU_LOGIN_CSG_OPNEG	       0x04
#define ISCSI_PDU_LOGIN_CSG_FF		       0x0c
#define ISCSI_PDU_LOGIN_NSG_SECNEG	       0x00
#define ISCSI_PDU_LOGIN_NSG_OPNEG	       0x01
#define ISCSI_PDU_LOGIN_NSG_FF		       0x03


#define ISCSI_PDU_SCSI_FINAL		       0x80
#define ISCSI_PDU_SCSI_READ		       0x40
#define ISCSI_PDU_SCSI_WRITE		       0x20
#define ISCSI_PDU_SCSI_ATTR_UNTAGGED	       0x00
#define ISCSI_PDU_SCSI_ATTR_SIMPLE	       0x01
#define ISCSI_PDU_SCSI_ATTR_ORDERED	       0x02
#define ISCSI_PDU_SCSI_ATTR_HEADOFQUEUE	       0x03
#define ISCSI_PDU_SCSI_ATTR_ACA		       0x04

#define ISCSI_PDU_DATA_FINAL		       0x80
#define ISCSI_PDU_DATA_ACK_REQUESTED	       0x40
#define ISCSI_PDU_DATA_BIDIR_OVERFLOW  	       0x10
#define ISCSI_PDU_DATA_BIDIR_UNDERFLOW         0x08
#define ISCSI_PDU_DATA_RESIDUAL_OVERFLOW       0x04
#define ISCSI_PDU_DATA_RESIDUAL_UNDERFLOW      0x02
#define ISCSI_PDU_DATA_CONTAINS_STATUS	       0x01

enum iscsi_opcode {ISCSI_PDU_NOP_OUT=0x00,
     		  ISCSI_PDU_SCSI_REQUEST=0x01,
     		  ISCSI_PDU_LOGIN_REQUEST=0x03,
		  ISCSI_PDU_TEXT_REQUEST=0x04,
		  ISCSI_PDU_LOGOUT_REQUEST=0x06,
		  ISCSI_PDU_NOP_IN=0x20,
     		  ISCSI_PDU_SCSI_RESPONSE=0x21,
     		  ISCSI_PDU_LOGIN_RESPONSE=0x23,
     		  ISCSI_PDU_TEXT_RESPONSE=0x24,
     		  ISCSI_PDU_DATA_IN=0x25,
     		  ISCSI_PDU_LOGOUT_RESPONSE=0x26};

struct iscsi_pdu {
       struct iscsi_pdu *prev, *next;

       uint32_t itt;
       uint32_t cmdsn;
       enum iscsi_opcode response_opcode;

       iscsi_command_cb callback;
       void *private_data;

       int written;
       struct iscsi_data outdata;
       struct iscsi_data indata;

       struct iscsi_scsi_cbdata *scsi_cbdata;
};

void iscsi_free_scsi_cbdata(struct iscsi_scsi_cbdata *scsi_cbdata);

struct iscsi_pdu *iscsi_allocate_pdu(struct iscsi_context *iscsi, enum iscsi_opcode opcode, enum iscsi_opcode response_opcode);
void iscsi_free_pdu(struct iscsi_context *iscsi, struct iscsi_pdu *pdu);
void iscsi_pdu_set_pduflags(struct iscsi_pdu *pdu, unsigned char flags);
void iscsi_pdu_set_immediate(struct iscsi_pdu *pdu);
void iscsi_pdu_set_ttt(struct iscsi_pdu *pdu, uint32_t ttt);
void iscsi_pdu_set_cmdsn(struct iscsi_pdu *pdu, uint32_t cmdsn);
void iscsi_pdu_set_lun(struct iscsi_pdu *pdu, uint32_t lun);
void iscsi_pdu_set_expstatsn(struct iscsi_pdu *pdu, uint32_t expstatsnsn);
void iscsi_pdu_set_expxferlen(struct iscsi_pdu *pdu, uint32_t expxferlen);
int iscsi_pdu_add_data(struct iscsi_context *iscsi, struct iscsi_pdu *pdu, const unsigned char *dptr, int dsize);
int iscsi_queue_pdu(struct iscsi_context *iscsi, struct iscsi_pdu *pdu);
int iscsi_add_data(struct iscsi_data *data, const unsigned char *dptr, int dsize, int pdualignment);
int iscsi_set_random_isid(struct iscsi_context *iscsi);

struct scsi_task;
void iscsi_pdu_set_cdb(struct iscsi_pdu *pdu, struct scsi_task *task);

int iscsi_get_pdu_size(const unsigned char *hdr);
int iscsi_process_pdu(struct iscsi_context *iscsi, const unsigned char *hdr, int size);

int iscsi_process_login_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu, const unsigned char *hdr, int size);
int iscsi_process_text_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu, const unsigned char *hdr, int size);
int iscsi_process_logout_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu, const unsigned char *hdr, int size);
int iscsi_process_scsi_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu, const unsigned char *hdr, int size);
int iscsi_process_scsi_data_in(struct iscsi_context *iscsi, struct iscsi_pdu *pdu, const unsigned char *hdr, int size, int *is_finished);
int iscsi_process_nop_out_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu, const unsigned char *hdr, int size);

#endif /* CCAN_ISCSI_PRIVATE_H */