#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "sg_lib.h"
#include "sg_io_linux.h"

/* This program performs a READ_16 command as scsi mid-level support
   16 byte commands from lk 2.4.15

*  Copyright (C) 2001-2018 D. Gilbert
*  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 2, or (at your option)
*  any later version.

   Invocation: sg_simple16 <scsi_device>

   Version 1.04 (20180218)

*/

#define READ16_REPLY_LEN 512
#define READ16_CMD_LEN 16

#define EBUFF_SZ 256

int main(int argc, char * argv[])
{
    int sg_fd, k, ok;
    uint8_t r16_cdb [READ16_CMD_LEN] =
                {0x88, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0};
    sg_io_hdr_t io_hdr;
    char * file_name = 0;
    char ebuff[EBUFF_SZ];
    uint8_t inBuff[READ16_REPLY_LEN];
    uint8_t sense_buffer[32];

    for (k = 1; k < argc; ++k) {
        if (*argv[k] == '-') {
            printf("Unrecognized switch: %s\n", argv[k]);
            file_name = 0;
            break;
        }
        else if (0 == file_name)
            file_name = argv[k];
        else {
            printf("too many arguments\n");
            file_name = 0;
            break;
        }
    }
    if (0 == file_name) {
        printf("Usage: 'sg_simple16 <sg_device>'\n");
        return 1;
    }

    if ((sg_fd = open(file_name, O_RDWR)) < 0) {
        snprintf(ebuff, EBUFF_SZ,
                 "sg_simple16: error opening file: %s", file_name);
        perror(ebuff);
        return 1;
    }
    /* Just to be safe, check we have a new sg device by trying an ioctl */
    if ((ioctl(sg_fd, SG_GET_VERSION_NUM, &k) < 0) || (k < 30000)) {
        printf("sg_simple16: %s doesn't seem to be an new sg device\n",
               file_name);
        close(sg_fd);
        return 1;
    }

    /* Prepare READ_16 command */
    memset(&io_hdr, 0, sizeof(sg_io_hdr_t));
    io_hdr.interface_id = 'S';
    io_hdr.cmd_len = sizeof(r16_cdb);
    /* io_hdr.iovec_count = 0; */  /* memset takes care of this */
    io_hdr.mx_sb_len = sizeof(sense_buffer);
    io_hdr.dxfer_direction = SG_DXFER_FROM_DEV;
    io_hdr.dxfer_len = READ16_REPLY_LEN;
    io_hdr.dxferp = inBuff;
    io_hdr.cmdp = r16_cdb;
    io_hdr.sbp = sense_buffer;
    io_hdr.timeout = 20000;     /* 20000 millisecs == 20 seconds */
    /* io_hdr.flags = 0; */     /* take defaults: indirect IO, etc */
    /* io_hdr.pack_id = 0; */
    /* io_hdr.usr_ptr = NULL; */

    if (ioctl(sg_fd, SG_IO, &io_hdr) < 0) {
        perror("sg_simple16: Inquiry SG_IO ioctl error");
        close(sg_fd);
        return 1;
    }

    /* now for the error processing */
    ok = 0;
    switch (sg_err_category3(&io_hdr)) {
    case SG_LIB_CAT_CLEAN:
        ok = 1;
        break;
    case SG_LIB_CAT_RECOVERED:
        printf("Recovered error on READ_16, continuing\n");
        ok = 1;
        break;
    default: /* won't bother decoding other categories */
        sg_chk_n_print3("READ_16 command error", &io_hdr, 1);
        break;
    }

    if (ok) { /* output result if it is available */
        printf("READ_16 duration=%u millisecs, resid=%d, msg_status=%d\n",
               io_hdr.duration, io_hdr.resid, (int)io_hdr.msg_status);
    }

    close(sg_fd);
    return 0;
}