ass.c

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <errno.h>
#include <dirent.h>
#include <getopt.h>

static int path_prepend(char **path, const char *fmt, ...)
{
        va_list va;
        char *pre;
        int err = 0;

        va_start(va, fmt);
        err = vasprintf(&pre, fmt, va);
        va_end(va);
        if (err < 0)
                goto out;

        if (*path != NULL) {
                char *new;

                err = asprintf(&new, "%s-%s", pre, *path);
                free(pre);
                if (err < 0)
                        goto out;
                free(*path);
                *path = new;
        } else {
                *path = pre;
        }
out:
        return err;
}

/*
** Linux only supports 32 bit luns.
** See drivers/scsi/scsi_scan.c::scsilun_to_int() for more details.
*/
static int format_lun_number(unsigned long lun, char **path) {
        /* address method 0, peripheral device addressing with bus id of zero */
        if (lun < 256)
                return path_prepend(path, "lun-%d", lun);
        /* handle all other lun addressing methods by using a variant of the original lun format */
        return path_prepend(path, "lun-0x%04x%04x00000000", (lun & 0xffff), (lun >> 16) & 0xffff);
}


int main() {

    unsigned long lun; 
    int converted_lun;

    for( lun = 0; lun < 65536; lun = lun + 1) {
        char *lun_str = NULL;
        converted_lun = format_lun_number(lun, &lun_str);
        printf("LUN(%lu) = %s\n", lun, lun_str);
    }

}