/*
 * Copyright (c) 2004-2012 Douglas Gilbert.
 * All rights reserved.
 * Use of this source code is governed by a BSD-style
 * license that can be found in the BSD_LICENSE file.
 */

#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#define __STDC_FORMAT_MACROS 1
#include <inttypes.h>

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "sg_lib.h"
#include "sg_cmds_basic.h"

/* A utility program originally written for the Linux OS SCSI subsystem.
 *
 *
 * This program issues the SCSI REPORT LUNS command to the given SCSI device
 * and decodes the response.
 */

static char * version_str = "1.17 20120314";

#define MAX_RLUNS_BUFF_LEN (1024 * 64)
#define DEF_RLUNS_BUFF_LEN (1024 * 8)

static unsigned char reportLunsBuff[MAX_RLUNS_BUFF_LEN];


static struct option long_options[] = {
        {"decode", no_argument, 0, 'd'},
        {"help", no_argument, 0, 'h'},
        {"hex", no_argument, 0, 'H'},
        {"maxlen", required_argument, 0, 'm'},
        {"quiet", no_argument, 0, 'q'},
        {"raw", no_argument, 0, 'r'},
        {"select", required_argument, 0, 's'},
        {"verbose", no_argument, 0, 'v'},
        {"version", no_argument, 0, 'V'},
        {0, 0, 0, 0},
};

static void
usage()
{
    fprintf(stderr, "Usage: "
            "sg_luns    [--decode] [--help] [--hex] [--maxlen=LEN] [--quiet] "
            "[--raw]\n"
            "                  [--select=SR] [--verbose] [--version] DEVICE\n"
            "  where:\n"
            "    --decode|-d        decode all luns into component parts\n"
            "    --help|-h          print out usage message\n"
            "    --hex|-H           output in hexadecimal\n"
            "    --maxlen=LEN|-m LEN    max response length (allocation "
            "length in cdb)\n"
            "                           (def: 0 -> %d bytes)\n",
            DEF_RLUNS_BUFF_LEN );
    fprintf(stderr, "    --quiet|-q         output only ASCII hex lun "
            "values\n"
            "    --raw|-r           output in binary\n"
            "    --select=SR|-s SR    select report SR (def: 0)\n"
            "                          0 -> luns apart from 'well "
            "known' lus\n"
            "                          1 -> only 'well known' "
            "logical unit numbers\n"
            "                          2 -> all luns\n"
            "    --verbose|-v       increase verbosity\n"
            "    --version|-V       print version string and exit\n\n"
            "Performs a SCSI REPORT LUNS command\n"
            );
}

/* Decoded according to SAM-5 rev 10. Note that one draft: BCC rev 0,
 * defines its own "bridge addressing method" in place of the SAM-3
 * "logical addressing method".  */
static void
decode_lun(const char * leadin, unsigned char * lunp)
{
    int k, j, x, a_method, bus_id, target, lun, len_fld, e_a_method;
    int next_level;
    unsigned int u;
    unsigned char not_spec[8] = {0xff, 0xff, 0xff, 0xff,
                                 0xff, 0xff, 0xff, 0xff};
    char l_leadin[128];
    uint64_t ull;

    if (0 == memcmp(lunp, not_spec, sizeof(not_spec))) {
        printf("%sLogical unit not specified\n", leadin);
        return;
    }
    memset(l_leadin, 0, sizeof(l_leadin));
    for (k = 0; k < 4; ++k, lunp += 2) {
        next_level = 0;
        strncpy(l_leadin, leadin, sizeof(l_leadin) - 3);
        if (k > 0) {
            printf("%s>>%s level addressing:\n", l_leadin,
                   ((1 == k) ? "Second" : ((2 == k) ? "Third" : "Fourth")));
            strcat(l_leadin, "  ");
        }
        a_method = (lunp[0] >> 6) & 0x3;
        switch (a_method) {
        case 0:         /* peripheral device addressing method */
            bus_id = lunp[0] & 0x3f;
            if (0 == bus_id)
                printf("%sPeripheral device addressing: lun=%d\n",
                       l_leadin, lunp[1]);
            else {
                printf("%sPeripheral device addressing: bus_id=%d, "
                       "target=%d\n", l_leadin, bus_id, lunp[1]);
                next_level = 1;
            }
            break;
        case 1:         /* flat space addressing method */
            lun = ((lunp[0] & 0x3f) << 8) + lunp[1];
            printf("%sFlat space addressing: lun=%d\n", l_leadin, lun);
            break;
        case 2:         /* logical unit addressing method */
            target = (lunp[0] & 0x3f);
            bus_id = (lunp[1] >> 5) & 0x7;
            lun = lunp[1] & 0x1f;
            printf("%sLogical unit addressing: bus_id=%d, target=%d, "
                   "lun=%d\n", l_leadin, bus_id, target, lun);
            break;
        case 3:         /* extended logical unit addressing method */
            len_fld = (lunp[0] & 0x30) >> 4;
            e_a_method = lunp[0] & 0xf;
            x = lunp[1];
            if ((0 == len_fld) && (1 == e_a_method)) {
                switch (x) {
                case 1:
                    printf("%sREPORT LUNS well known logical unit\n",
                           l_leadin);
                    break;
                case 2:
                    printf("%sACCESS CONTROLS well known logical unit\n",
                           l_leadin);
                    break;
                case 3:
                    printf("%sTARGET LOG PAGES well known logical unit\n",
                           l_leadin);
                    break;
                case 4:
                    printf("%sSECURITY PROTOCOL well known logical unit\n",
                           l_leadin);
                    break;
                default:
                    printf("%swell known logical unit %d\n", l_leadin, x);
                    break;
                }
            } else if ((1 == len_fld) && (2 == e_a_method)) {
                x = (lunp[1] << 16) + (lunp[2] << 8) + lunp[3];
                printf("%sExtended flat space logical unit addressing: "
                       "value=0x%x\n", l_leadin, x);
            } else if ((2 == len_fld) && (2 == e_a_method)) {
                u = (lunp[1] << 24) + (lunp[2] << 16) + (lunp[3] << 8) +
                    lunp[4];
                printf("%sLong extended flat space logical unit addressing: "
                       "value=0x%x\n", l_leadin, u);
            } else if ((3 == len_fld) && (0xf == e_a_method))
                printf("%sLogical unit _not_ specified addressing\n",
                       l_leadin);
            else {
                if (len_fld < 2) {
                    if (1 == len_fld)
                        x = (lunp[1] << 16) + (lunp[2] << 8) + lunp[3];
                    printf("%sExtended logical unit addressing: length=%d, "
                           "e.a. method=%d, value=0x%x\n", l_leadin, len_fld,
                           e_a_method, x);
                } else {
                    ull = 0;
                    x = (2 == len_fld) ? 5 : 7;
                    for (j = 0; j < x; ++j) {
                        if (j > 0)
                            ull <<= 8;
                        ull |= lunp[1 + j];
                    }
                    printf("%sExtended logical unit addressing: length=%d, "
                           "e. a. method=%d, value=0x%" PRIx64 "\n",
                           l_leadin, len_fld, e_a_method, ull);
                }
            }
            break;
        default:
            printf("%s<<decode_lun: faulty logic>>\n", l_leadin);
            break;
        }
        if (next_level)
            continue;
        if ((2 == a_method) && (k < 3) && (lunp[2] || lunp[3]))
            printf("%s<<unexpected data at next level, continue>>\n",
                   l_leadin);
        break;
    }
}

static void
dStrRaw(const char* str, int len)
{
    int k;

    for (k = 0 ; k < len; ++k)
        printf("%c", str[k]);
}

int
main(int argc, char * argv[])
{
    int sg_fd, k, m, off, res, c, list_len, luns, trunc;
    int decode = 0;
    int do_hex = 0;
    int maxlen = 0;
    int do_quiet = 0;
    int do_raw = 0;
    int select_rep = 0;
    int verbose = 0;
    const char * device_name = NULL;
    int ret = 0;

    while (1) {
        int option_index = 0;

        c = getopt_long(argc, argv, "dhHm:qrs:vV", long_options,
                        &option_index);
        if (c == -1)
            break;

        switch (c) {
        case 'd':
            decode = 1;
            break;
        case 'h':
        case '?':
            usage();
            return 0;
        case 'H':
            ++do_hex;
            break;
        case 'm':
            maxlen = sg_get_num(optarg);
            if ((maxlen < 0) || (maxlen > MAX_RLUNS_BUFF_LEN)) {
                fprintf(stderr, "argument to '--maxlen' should be %d or "
                        "less\n", MAX_RLUNS_BUFF_LEN);
                return SG_LIB_SYNTAX_ERROR;
            }
            break;
        case 'q':
            ++do_quiet;
            break;
        case 'r':
            ++do_raw;
            break;
        case 's':
           if ((1 != sscanf(optarg, "%d", &select_rep)) ||
               (select_rep < 0) || (select_rep > 255)) {
                fprintf(stderr, "bad argument to '--select'\n");
                return SG_LIB_SYNTAX_ERROR;
            }
            break;
        case 'v':
            ++verbose;
            break;
        case 'V':
            fprintf(stderr, "version: %s\n", version_str);
            return 0;
        default:
            fprintf(stderr, "unrecognised option code 0x%x ??\n", c);
            usage();
            return SG_LIB_SYNTAX_ERROR;
        }
    }
    if (optind < argc) {
        if (NULL == device_name) {
            device_name = argv[optind];
            ++optind;
        }
        if (optind < argc) {
            for (; optind < argc; ++optind)
                fprintf(stderr, "Unexpected extra argument: %s\n",
                        argv[optind]);
            usage();
            return SG_LIB_SYNTAX_ERROR;
        }
    }

    if (NULL == device_name) {
        fprintf(stderr, "missing device name!\n");
        usage();
        return SG_LIB_SYNTAX_ERROR;
    }
    if (0 == maxlen)
        maxlen = DEF_RLUNS_BUFF_LEN;
    if (do_raw) {
        if (sg_set_binary_mode(STDOUT_FILENO) < 0) {
            perror("sg_set_binary_mode");
            return SG_LIB_FILE_ERROR;
        }
    }

    sg_fd = sg_cmds_open_device(device_name, 0 /* rw */, verbose);
    if (sg_fd < 0) {
        fprintf(stderr, "open error: %s: %s\n", device_name,
                safe_strerror(-sg_fd));
        return SG_LIB_FILE_ERROR;
    }

    memset(reportLunsBuff, 0x0, maxlen);
    trunc = 0;

    res = sg_ll_report_luns(sg_fd, select_rep, reportLunsBuff, maxlen, 1,
                            verbose);
    ret = res;
    if (0 == res) {
        list_len = (reportLunsBuff[0] << 24) + (reportLunsBuff[1] << 16) +
                   (reportLunsBuff[2] << 8) + reportLunsBuff[3];
        if (do_raw) {
            dStrRaw((const char *)reportLunsBuff, list_len + 8);
            goto the_end;
        }
        if (do_hex) {
            dStrHex((const char *)reportLunsBuff, list_len + 8, 1);
            goto the_end;
        }
        luns = (list_len / 8);
        if (0 == do_quiet)
            printf("Lun list length = %d which imples %d lun entr%s\n",
                   list_len, luns, ((1 == luns) ? "y" : "ies"));
        if ((list_len + 8) > maxlen) {
            luns = ((maxlen - 8) / 8);
            trunc = 1;
            fprintf(stderr, "  <<too many luns for internal buffer, will "
                    "show %d lun%s>>\n", luns, ((1 == luns) ? "" : "s"));
        }
        if (verbose > 1) {
            fprintf(stderr, "\nOutput response in hex\n");
            dStrHex((const char *)reportLunsBuff,
                    (trunc ? maxlen : list_len + 8), 1);
        }
        for (k = 0, off = 8; k < luns; ++k) {
            if (0 == do_quiet) {
                if (0 == k)
                    printf("Report luns [select_report=0x%x]:\n", select_rep);
                printf("    ");
            }
            for (m = 0; m < 8; ++m, ++off)
                printf("%02x", reportLunsBuff[off]);
            printf("\n");
            if (decode)
                decode_lun("      ", reportLunsBuff + off - 8);
        }
    } else if (SG_LIB_CAT_INVALID_OP == res)
        fprintf(stderr, "Report Luns command not supported (support "
                "mandatory in SPC-3)\n");
    else if (SG_LIB_CAT_ABORTED_COMMAND == res)
        fprintf(stderr, "Report Luns, aborted command\n");
    else if (SG_LIB_CAT_ILLEGAL_REQ == res)
        fprintf(stderr, "Report Luns command has bad field in cdb\n");
    else {
        fprintf(stderr, "Report Luns command failed\n");
        if (0 == verbose)
            fprintf(stderr, "    try '-v' option for more information\n");
    }

the_end:
    res = sg_cmds_close_device(sg_fd);
    if (res < 0) {
        fprintf(stderr, "close error: %s\n", safe_strerror(-res));
        if (0 == ret)
            return SG_LIB_FILE_ERROR;
    }
    return (ret >= 0) ? ret : SG_LIB_CAT_OTHER;
}
