/*
 * Copyright (c) 1999-2016 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.
 */

/*
 * CONTENTS
 *    Some SCSI commands are executed in many contexts and hence began
 *    to appear in several sg3_utils utilities. This files centralizes
 *    some of the low level command execution code. In most cases the
 *    interpretation of the command response is left to the each
 *    utility.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include "sg_lib.h"
#include "sg_cmds_basic.h"
#include "sg_pt.h"
#include "sg_unaligned.h"

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

/* Needs to be after config.h */
#ifdef SG_LIB_LINUX
#include <errno.h>
#endif


static const char * version_str = "1.72 20160126";


#define SENSE_BUFF_LEN 64       /* Arbitrary, could be larger */
#define EBUFF_SZ 256

#define DEF_PT_TIMEOUT 60       /* 60 seconds */
#define START_PT_TIMEOUT 120    /* 120 seconds == 2 minutes */
#define LONG_PT_TIMEOUT 7200    /* 7,200 seconds == 120 minutes */

#define INQUIRY_CMD     0x12
#define INQUIRY_CMDLEN  6
#define REQUEST_SENSE_CMD 0x3
#define REQUEST_SENSE_CMDLEN 6
#define REPORT_LUNS_CMD 0xa0
#define REPORT_LUNS_CMDLEN 12
#define TUR_CMD  0x0
#define TUR_CMDLEN  6

#define SAFE_STD_INQ_RESP_LEN 36 /* other lengths lock up some devices */


const char *
sg_cmds_version()
{
    return version_str;
}

#ifdef __GNUC__
static int pr2ws(const char * fmt, ...)
        __attribute__ ((format (printf, 1, 2)));
#else
static int pr2ws(const char * fmt, ...);
#endif


static int
pr2ws(const char * fmt, ...)
{
    va_list args;
    int n;

    va_start(args, fmt);
    n = vfprintf(sg_warnings_strm ? sg_warnings_strm : stderr, fmt, args);
    va_end(args);
    return n;
}

/* Returns file descriptor >= 0 if successful. If error in Unix returns
   negated errno. */
int
sg_cmds_open_device(const char * device_name, int read_only, int verbose)
{
    /* The following 2 lines are temporary. It is to avoid a NULL pointer
     * crash when an old utility is used with a newer library built after
     * the sg_warnings_strm cleanup */
    if (NULL == sg_warnings_strm)
        sg_warnings_strm = stderr;

    return scsi_pt_open_device(device_name, read_only, verbose);
}

/* Returns file descriptor >= 0 if successful. If error in Unix returns
   negated errno. */
int
sg_cmds_open_flags(const char * device_name, int flags, int verbose)
{
    return scsi_pt_open_flags(device_name, flags, verbose);
}

/* Returns 0 if successful. If error in Unix returns negated errno. */
int
sg_cmds_close_device(int device_fd)
{
    return scsi_pt_close_device(device_fd);
}

static int
sg_cmds_process_helper(const char * leadin, int mx_di_len, int resid,
                       const unsigned char * sbp, int slen, int noisy,
                       int verbose, int * o_sense_cat)
{
    int scat, got;
    int n = 0;
    int check_data_in = 0;
    char b[512];

    scat = sg_err_category_sense(sbp, slen);
    switch (scat) {
    case SG_LIB_CAT_NOT_READY:
    case SG_LIB_CAT_INVALID_OP:
    case SG_LIB_CAT_ILLEGAL_REQ:
    case SG_LIB_CAT_ABORTED_COMMAND:
    case SG_LIB_CAT_COPY_ABORTED:
    case SG_LIB_CAT_DATA_PROTECT:
    case SG_LIB_CAT_PROTECTION:
    case SG_LIB_CAT_NO_SENSE:
    case SG_LIB_CAT_MISCOMPARE:
        n = 0;
        break;
    case SG_LIB_CAT_RECOVERED:
    case SG_LIB_CAT_MEDIUM_HARD:
        ++check_data_in;
        /* drop through */
    case SG_LIB_CAT_UNIT_ATTENTION:
    case SG_LIB_CAT_SENSE:
    default:
        n = noisy;
        break;
    }
    if (verbose || n) {
        if (leadin && (strlen(leadin) > 0))
            pr2ws("%s:\n", leadin);
        sg_get_sense_str(NULL, sbp, slen, (verbose > 1),
                         sizeof(b), b);
        pr2ws("%s", b);
        if ((mx_di_len > 0) && (resid > 0)) {
            got = mx_di_len - resid;
            if ((verbose > 2) || check_data_in || (got > 0))
                pr2ws("    pass-through requested %d bytes (data-in) but "
                      "got %d bytes\n", mx_di_len, got);
        }
    }
    if (o_sense_cat)
        *o_sense_cat = scat;
    return -2;
}

/* This is a helper function used by sg_cmds_* implementations after the
 * call to the pass-through. pt_res is returned from do_scsi_pt(). If valid
 * sense data is found it is decoded and output to sg_warnings_strm (def:
 * stderr); depending on the 'noisy' and 'verbose' settings. Returns -2 for
 * "sense" category (may not be fatal), -1 for failed, 0, or a positive
 * number. If 'mx_di_len > 0' then asks pass-through for resid and returns
 * (mx_di_len - resid); otherwise returns 0. So for data-in it should return
 * the actual number of bytes received. For data-out (to device) or no data
 * call with 'mx_di_len' set to 0 or less. If -2 returned then sense category
 * output via 'o_sense_cat' pointer (if not NULL). Note that several sense
 * categories also have data in bytes received; -2 is still returned. */
int
sg_cmds_process_resp(struct sg_pt_base * ptvp, const char * leadin,
                     int pt_res, int mx_di_len, const unsigned char * sbp,
                     int noisy, int verbose, int * o_sense_cat)
{
    int got, cat, duration, slen, resid, resp_code, sstat, transport_sense;
    char b[1024];

    if (NULL == leadin)
        leadin = "";
    if (pt_res < 0) {
#ifdef SG_LIB_LINUX
        if (verbose)
            pr2ws("%s: pass through os error: %s\n", leadin,
                  safe_strerror(-pt_res));
        if ((-ENXIO == pt_res) && o_sense_cat) {
            if (verbose > 2)
                pr2ws("map ENXIO to SG_LIB_CAT_NOT_READY\n");
            *o_sense_cat = SG_LIB_CAT_NOT_READY;
            return -2;
        } else if (noisy && (0 == verbose))
            pr2ws("%s: pass through os error: %s\n", leadin,
                  safe_strerror(-pt_res));
#else
        if (noisy || verbose)
            pr2ws("%s: pass through os error: %s\n", leadin,
                  safe_strerror(-pt_res));
#endif
        return -1;
    } else if (SCSI_PT_DO_BAD_PARAMS == pt_res) {
        pr2ws("%s: bad pass through setup\n", leadin);
        return -1;
    } else if (SCSI_PT_DO_TIMEOUT == pt_res) {
        pr2ws("%s: pass through timeout\n", leadin);
        return -1;
    }
    if ((verbose > 2) && ((duration = get_scsi_pt_duration_ms(ptvp)) >= 0))
        pr2ws("      duration=%d ms\n", duration);
    resid = (mx_di_len > 0) ? get_scsi_pt_resid(ptvp) : 0;
    slen = get_scsi_pt_sense_len(ptvp);
    switch ((cat = get_scsi_pt_result_category(ptvp))) {
    case SCSI_PT_RESULT_GOOD:
        if (sbp && (slen > 7)) {
            resp_code = sbp[0] & 0x7f;
            /* SBC referrals can have status=GOOD and sense_key=COMPLETED */
            if (resp_code >= 0x70) {
                if (resp_code < 0x72) {
                    if (SPC_SK_NO_SENSE != (0xf & sbp[2]))
                        sg_err_category_sense(sbp, slen);
                } else if (resp_code < 0x74) {
                    if (SPC_SK_NO_SENSE != (0xf & sbp[1]))
                        sg_err_category_sense(sbp, slen);
                }
            }
        }
        if (mx_di_len > 0) {
            got = mx_di_len - resid;
            if ((verbose > 1) && (resid != 0))
                pr2ws("    %s: pass-through requested %d bytes (data-in) "
                      "but got %d bytes\n", leadin, mx_di_len, got);
            if (got >= 0)
                return got;
            else {
                if (verbose)
                    pr2ws("    %s: pass-through can't get negative bytes, "
                          "say it got none\n", leadin);
                return 0;
            }
        } else
            return 0;
    case SCSI_PT_RESULT_STATUS: /* other than GOOD and CHECK CONDITION */
        sstat = get_scsi_pt_status_response(ptvp);
        if (o_sense_cat) {
            switch (sstat) {
            case SAM_STAT_RESERVATION_CONFLICT:
                *o_sense_cat = SG_LIB_CAT_RES_CONFLICT;
                return -2;
            case SAM_STAT_CONDITION_MET:
                *o_sense_cat = SG_LIB_CAT_CONDITION_MET;
                return -2;
            case SAM_STAT_BUSY:
                *o_sense_cat = SG_LIB_CAT_BUSY;
                return -2;
            case SAM_STAT_TASK_SET_FULL:
                *o_sense_cat = SG_LIB_CAT_TS_FULL;
                return -2;
            case SAM_STAT_ACA_ACTIVE:
                *o_sense_cat = SG_LIB_CAT_ACA_ACTIVE;
                return -2;
            case SAM_STAT_TASK_ABORTED:
                *o_sense_cat = SG_LIB_CAT_TASK_ABORTED;
                return -2;
            default:
                break;
            }
        }
        if (verbose || noisy) {
            sg_get_scsi_status_str(sstat, sizeof(b), b);
            pr2ws("%s: scsi status: %s\n", leadin, b);
        }
        return -1;
    case SCSI_PT_RESULT_SENSE:
        return sg_cmds_process_helper(leadin, mx_di_len, resid, sbp, slen,
                                      noisy, verbose, o_sense_cat);
    case SCSI_PT_RESULT_TRANSPORT_ERR:
        if (verbose || noisy) {
            get_scsi_pt_transport_err_str(ptvp, sizeof(b), b);
            pr2ws("%s: transport: %s\n", leadin, b);
        }
#ifdef SG_LIB_LINUX
        transport_sense = (slen > 0);
#else
        transport_sense = ((SAM_STAT_CHECK_CONDITION ==
                            get_scsi_pt_status_response(ptvp)) && (slen > 0));
#endif
        if (transport_sense)
            return sg_cmds_process_helper(leadin, mx_di_len, resid, sbp,
                                          slen, noisy, verbose, o_sense_cat);
        else
            return -1;
    case SCSI_PT_RESULT_OS_ERR:
        if (verbose || noisy) {
            get_scsi_pt_os_err_str(ptvp, sizeof(b), b);
            pr2ws("%s: os: %s\n", leadin, b);
        }
        return -1;
    default:
        pr2ws("%s: unknown pass through result category (%d)\n", leadin, cat);
        return -1;
    }
}

/* Invokes a SCSI INQUIRY command and yields the response. Returns 0 when
 * successful, various SG_LIB_CAT_* positive values or -1 -> other errors */
int
sg_ll_inquiry(int sg_fd, int cmddt, int evpd, int pg_op, void * resp,
              int mx_resp_len, int noisy, int verbose)
{
    int res, ret, k, sense_cat, resid;
    unsigned char inqCmdBlk[INQUIRY_CMDLEN] = {INQUIRY_CMD, 0, 0, 0, 0, 0};
    unsigned char sense_b[SENSE_BUFF_LEN];
    unsigned char * up;
    struct sg_pt_base * ptvp;

    if (cmddt)
        inqCmdBlk[1] |= 2;
    if (evpd)
        inqCmdBlk[1] |= 1;
    inqCmdBlk[2] = (unsigned char)pg_op;
    /* 16 bit allocation length (was 8) is a recent SPC-3 addition */
    sg_put_unaligned_be16((uint16_t)mx_resp_len, inqCmdBlk + 3);
    if (verbose) {
        pr2ws("    inquiry cdb: ");
        for (k = 0; k < INQUIRY_CMDLEN; ++k)
            pr2ws("%02x ", inqCmdBlk[k]);
        pr2ws("\n");
    }
    if (resp && (mx_resp_len > 0)) {
        up = (unsigned char *)resp;
        up[0] = 0x7f;   /* defensive prefill */
        if (mx_resp_len > 4)
            up[4] = 0;
    }
    ptvp = construct_scsi_pt_obj();
    if (NULL == ptvp) {
        pr2ws("inquiry: out of memory\n");
        return -1;
    }
    set_scsi_pt_cdb(ptvp, inqCmdBlk, sizeof(inqCmdBlk));
    set_scsi_pt_sense(ptvp, sense_b, sizeof(sense_b));
    set_scsi_pt_data_in(ptvp, (unsigned char *)resp, mx_resp_len);
    res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
    ret = sg_cmds_process_resp(ptvp, "inquiry", res, mx_resp_len, sense_b,
                               noisy, verbose, &sense_cat);
    resid = get_scsi_pt_resid(ptvp);
    destruct_scsi_pt_obj(ptvp);
    if (-1 == ret)
        ;
    else if (-2 == ret) {
        switch (sense_cat) {
        case SG_LIB_CAT_RECOVERED:
        case SG_LIB_CAT_NO_SENSE:
            ret = 0;
            break;
        default:
            ret = sense_cat;
            break;
        }
    } else if (ret < 4) {
        if (verbose)
            pr2ws("inquiry: got too few bytes (%d)\n", ret);
        ret = SG_LIB_CAT_MALFORMED;
    } else
        ret = 0;

    if (resid > 0) {
        if (resid > mx_resp_len) {
            pr2ws("inquiry: resid (%d) should never exceed requested "
                  "len=%d\n", resid, mx_resp_len);
            return ret ? ret : SG_LIB_CAT_MALFORMED;
        }
        /* zero unfilled section of response buffer */
        memset((unsigned char *)resp + (mx_resp_len - resid), 0, resid);
    }
    return ret;
}

/* Yields most of first 36 bytes of a standard INQUIRY (evpd==0) response.
 * Returns 0 when successful, various SG_LIB_CAT_* positive values or
 * -1 -> other errors */
int
sg_simple_inquiry(int sg_fd, struct sg_simple_inquiry_resp * inq_data,
                  int noisy, int verbose)
{
    int res, ret, k, sense_cat;
    unsigned char inqCmdBlk[INQUIRY_CMDLEN] = {INQUIRY_CMD, 0, 0, 0, 0, 0};
    unsigned char sense_b[SENSE_BUFF_LEN];
    unsigned char inq_resp[SAFE_STD_INQ_RESP_LEN];
    struct sg_pt_base * ptvp;

    if (inq_data) {
        memset(inq_data, 0, sizeof(* inq_data));
        inq_data->peripheral_qualifier = 0x3;
        inq_data->peripheral_type = 0x1f;
    }
    inqCmdBlk[4] = (unsigned char)sizeof(inq_resp);
    if (verbose) {
        pr2ws("    inquiry cdb: ");
        for (k = 0; k < INQUIRY_CMDLEN; ++k)
            pr2ws("%02x ", inqCmdBlk[k]);
        pr2ws("\n");
    }
    memset(inq_resp, 0, sizeof(inq_resp));
    inq_resp[0] = 0x7f; /* defensive prefill */
    ptvp = construct_scsi_pt_obj();
    if (NULL == ptvp) {
        pr2ws("inquiry: out of memory\n");
        return -1;
    }
    set_scsi_pt_cdb(ptvp, inqCmdBlk, sizeof(inqCmdBlk));
    set_scsi_pt_sense(ptvp, sense_b, sizeof(sense_b));
    set_scsi_pt_data_in(ptvp, inq_resp, sizeof(inq_resp));
    res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
    ret = sg_cmds_process_resp(ptvp, "inquiry", res, sizeof(inq_resp),
                               sense_b, noisy, verbose, &sense_cat);
    if (-1 == ret)
        ;
    else if (-2 == ret) {
        switch (sense_cat) {
        case SG_LIB_CAT_RECOVERED:
        case SG_LIB_CAT_NO_SENSE:
            ret = 0;
            break;
        default:
            ret = sense_cat;
            break;
        }
    } else if (ret < 4) {
        if (verbose)
            pr2ws("inquiry: got too few bytes (%d)\n", ret);
        ret = SG_LIB_CAT_MALFORMED;
    } else
        ret = 0;

    if (inq_data && (0 == ret)) {
        inq_data->peripheral_qualifier = (inq_resp[0] >> 5) & 0x7;
        inq_data->peripheral_type = inq_resp[0] & 0x1f;
        inq_data->byte_1 = inq_resp[1];
        inq_data->version = inq_resp[2];
        inq_data->byte_3 = inq_resp[3];
        inq_data->byte_5 = inq_resp[5];
        inq_data->byte_6 = inq_resp[6];
        inq_data->byte_7 = inq_resp[7];
        memcpy(inq_data->vendor, inq_resp + 8, 8);
        memcpy(inq_data->product, inq_resp + 16, 16);
        memcpy(inq_data->revision, inq_resp + 32, 4);
    }
    destruct_scsi_pt_obj(ptvp);
    return ret;
}

/* Invokes a SCSI TEST UNIT READY command.
 * 'pack_id' is just for diagnostics, safe to set to 0.
 * Looks for progress indicator if 'progress' non-NULL;
 * if found writes value [0..65535] else write -1.
 * Returns 0 when successful, various SG_LIB_CAT_* positive values or
 * -1 -> other errors */
int
sg_ll_test_unit_ready_progress(int sg_fd, int pack_id, int * progress,
                               int noisy, int verbose)
{
    int res, ret, k, sense_cat;
    unsigned char turCmdBlk[TUR_CMDLEN] = {TUR_CMD, 0, 0, 0, 0, 0};
    unsigned char sense_b[SENSE_BUFF_LEN];
    struct sg_pt_base * ptvp;

    if (verbose) {
        pr2ws("    test unit ready cdb: ");
        for (k = 0; k < TUR_CMDLEN; ++k)
            pr2ws("%02x ", turCmdBlk[k]);
        pr2ws("\n");
    }

    ptvp = construct_scsi_pt_obj();
    if (NULL == ptvp) {
        pr2ws("test unit ready: out of memory\n");
        return -1;
    }
    set_scsi_pt_cdb(ptvp, turCmdBlk, sizeof(turCmdBlk));
    set_scsi_pt_sense(ptvp, sense_b, sizeof(sense_b));
    set_scsi_pt_packet_id(ptvp, pack_id);
    res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
    ret = sg_cmds_process_resp(ptvp, "test unit ready", res, 0, sense_b,
                               noisy, verbose, &sense_cat);
    if (-1 == ret)
        ;
    else if (-2 == ret) {
        if (progress) {
            int slen = get_scsi_pt_sense_len(ptvp);

            if (! sg_get_sense_progress_fld(sense_b, slen, progress))
                *progress = -1;
        }
        switch (sense_cat) {
        case SG_LIB_CAT_RECOVERED:
        case SG_LIB_CAT_NO_SENSE:
            ret = 0;
            break;
        default:
            ret = sense_cat;
            break;
        }
    } else
        ret = 0;

    destruct_scsi_pt_obj(ptvp);
    return ret;
}

/* Invokes a SCSI TEST UNIT READY command.
 * 'pack_id' is just for diagnostics, safe to set to 0.
 * Returns 0 when successful, various SG_LIB_CAT_* positive values or
 * -1 -> other errors */
int
sg_ll_test_unit_ready(int sg_fd, int pack_id, int noisy, int verbose)
{
    return sg_ll_test_unit_ready_progress(sg_fd, pack_id, NULL, noisy,
                                          verbose);
}

/* Invokes a SCSI REQUEST SENSE command. Returns 0 when successful, various
 * SG_LIB_CAT_* positive values or -1 -> other errors */
int
sg_ll_request_sense(int sg_fd, int desc, void * resp, int mx_resp_len,
                    int noisy, int verbose)
{
    int k, ret, res, sense_cat;
    unsigned char rsCmdBlk[REQUEST_SENSE_CMDLEN] =
        {REQUEST_SENSE_CMD, 0, 0, 0, 0, 0};
    unsigned char sense_b[SENSE_BUFF_LEN];
    struct sg_pt_base * ptvp;

    if (desc)
        rsCmdBlk[1] |= 0x1;
    if (mx_resp_len > 0xff) {
        pr2ws("mx_resp_len cannot exceed 255\n");
        return -1;
    }
    rsCmdBlk[4] = mx_resp_len & 0xff;
    if (verbose) {
        pr2ws("    Request Sense cmd: ");
        for (k = 0; k < REQUEST_SENSE_CMDLEN; ++k)
            pr2ws("%02x ", rsCmdBlk[k]);
        pr2ws("\n");
    }

    ptvp = construct_scsi_pt_obj();
    if (NULL == ptvp) {
        pr2ws("request sense: out of memory\n");
        return -1;
    }
    set_scsi_pt_cdb(ptvp, rsCmdBlk, sizeof(rsCmdBlk));
    set_scsi_pt_sense(ptvp, sense_b, sizeof(sense_b));
    set_scsi_pt_data_in(ptvp, (unsigned char *)resp, mx_resp_len);
    res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
    ret = sg_cmds_process_resp(ptvp, "request sense", res, mx_resp_len,
                               sense_b, noisy, verbose, &sense_cat);
    if (-1 == ret)
        ;
    else if (-2 == ret) {
        switch (sense_cat) {
        case SG_LIB_CAT_RECOVERED:
        case SG_LIB_CAT_NO_SENSE:
            ret = 0;
            break;
        default:
            ret = sense_cat;
            break;
        }
    } else {
        if ((mx_resp_len >= 8) && (ret < 8)) {
            if (verbose)
                pr2ws("    request sense: got %d bytes in response, too "
                      "short\n", ret);
            ret = -1;
        } else
            ret = 0;
    }
    destruct_scsi_pt_obj(ptvp);
    return ret;
}

/* Invokes a SCSI REPORT LUNS command. Return of 0 -> success,
 * various SG_LIB_CAT_* positive values or -1 -> other errors */
int
sg_ll_report_luns(int sg_fd, int select_report, void * resp, int mx_resp_len,
                  int noisy, int verbose)
{
    int k, ret, res, sense_cat;
    unsigned char rlCmdBlk[REPORT_LUNS_CMDLEN] =
                         {REPORT_LUNS_CMD, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
    unsigned char sense_b[SENSE_BUFF_LEN];
    struct sg_pt_base * ptvp;

    rlCmdBlk[2] = select_report & 0xff;
    sg_put_unaligned_be32((uint32_t)mx_resp_len, rlCmdBlk + 6);
    if (verbose) {
        pr2ws("    report luns cdb: ");
        for (k = 0; k < REPORT_LUNS_CMDLEN; ++k)
            pr2ws("%02x ", rlCmdBlk[k]);
        pr2ws("\n");
    }

    ptvp = construct_scsi_pt_obj();
    if (NULL == ptvp) {
        pr2ws("report luns: out of memory\n");
        return -1;
    }
    set_scsi_pt_cdb(ptvp, rlCmdBlk, sizeof(rlCmdBlk));
    set_scsi_pt_sense(ptvp, sense_b, sizeof(sense_b));
    set_scsi_pt_data_in(ptvp, (unsigned char *)resp, mx_resp_len);
    res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
    ret = sg_cmds_process_resp(ptvp, "report luns", res, mx_resp_len,
                               sense_b, noisy, verbose, &sense_cat);
    if (-1 == ret)
        ;
    else if (-2 == ret) {
        switch (sense_cat) {
        case SG_LIB_CAT_RECOVERED:
        case SG_LIB_CAT_NO_SENSE:
            ret = 0;
            break;
        default:
            ret = sense_cat;
            break;
        }
    } else
        ret = 0;
    destruct_scsi_pt_obj(ptvp);
    return ret;
}