/*
 * (c) 2000 Kurt Garloff
 * heavily based on Douglas Gilbert's sg_rbuf program.
 * (c) 1999-2019 Douglas Gilbert
 *
 * Program to test the SCSI host adapter by issuing
 * write and read operations on a device's buffer
 * and calculating checksums.
 * NOTE: If you can not reserve the buffer of the device
 * for this purpose (SG_GET_RESERVED_SIZE), you risk
 * serious data corruption, if the device is accessed by
 * somebody else in the meantime.
 *
 *  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.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * $Id: sg_test_rwbuf.c,v 1.1 2000/03/02 13:50:03 garloff Exp $
 *
 *   2003/11/11  switch sg3_utils version to use SG_IO ioctl [dpg]
 *   2004/06/08  remove SG_GET_VERSION_NUM check [dpg]
 */

#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <getopt.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <time.h>

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

#include "sg_lib.h"
#include "sg_io_linux.h"
#include "sg_unaligned.h"
#include "sg_pr2serr.h"


static const char * version_str = "1.20 20191220";

#define BPI (signed)(sizeof(int))

#define RB_MODE_DESC 3
#define RWB_MODE_DATA 2
#define RB_DESC_LEN 4

/*  The microcode in a SCSI device is _not_ modified by doing a WRITE BUFFER
 *  with mode set to "data" (0x2) as done by this utility. Therefore this
 *  utility is safe in that respect. [Mode values 0x4, 0x5, 0x6 and 0x7 are
 *  the dangerous ones :-)]
 */

#define ME "sg_test_rwbuf: "

static int base = 0x12345678;
static int buf_capacity = 0;
static int buf_granul = 255;
static uint8_t *cmpbuf = NULL;
static uint8_t *free_cmpbuf = NULL;


/* Options */
static int size = -1;
static bool do_quick = false;
static int addwrite  = 0;
static int addread   = 0;
static int verbose   = 0;

static struct option long_options[] = {
        {"help", no_argument, 0, 'h'},
        {"quick", no_argument, 0, 'q'},
        {"addrd", required_argument, 0, 'r'},
        {"size", required_argument, 0, 's'},
        {"times", required_argument, 0, 't'},
        {"verbose", no_argument, 0, 'v'},
        {"version", no_argument, 0, 'V'},
        {"addwr", required_argument, 0, 'w'},
        {0, 0, 0, 0},
};

static int
find_out_about_buffer(int sg_fd)
{
        uint8_t rb_cdb[] = {READ_BUFFER, 0, 0, 0, 0, 0, 0, 0, 0, 0};
        uint8_t rbBuff[RB_DESC_LEN];
        uint8_t sense_buffer[32];
        struct sg_io_hdr io_hdr;
        int res;

        rb_cdb[1] = RB_MODE_DESC;
        rb_cdb[8] = RB_DESC_LEN;
        memset(&io_hdr, 0, sizeof(struct sg_io_hdr));
        io_hdr.interface_id = 'S';
        io_hdr.cmd_len = sizeof(rb_cdb);
        io_hdr.mx_sb_len = sizeof(sense_buffer);
        io_hdr.dxfer_direction = SG_DXFER_FROM_DEV;
        io_hdr.dxfer_len = RB_DESC_LEN;
        io_hdr.dxferp = rbBuff;
        io_hdr.cmdp = rb_cdb;
        io_hdr.sbp = sense_buffer;
        io_hdr.timeout = 60000;     /* 60000 millisecs == 60 seconds */

        if (verbose) {
                char b[128];

                pr2serr("    read buffer [mode desc] cdb: %s\n",
                        sg_get_command_str(rb_cdb, (int)sizeof(rb_cdb), false,
                                           sizeof(b), b));
        }
        if (ioctl(sg_fd, SG_IO, &io_hdr) < 0) {
                perror(ME "SG_IO READ BUFFER descriptor error");
                return -1;
        }
        /* now for the error processing */
        res = sg_err_category3(&io_hdr);
        switch (res) {
        case SG_LIB_CAT_RECOVERED:
                sg_chk_n_print3("READ BUFFER descriptor, continuing",
                                &io_hdr, true);
#if defined(__GNUC__)
#if (__GNUC__ >= 7)
                __attribute__((fallthrough));
                /* FALL THROUGH */
#endif
#endif
        case SG_LIB_CAT_CLEAN:
                break;
        default: /* won't bother decoding other categories */
                sg_chk_n_print3("READ BUFFER descriptor error", &io_hdr,
                                true);
                return res;
        }

        buf_capacity = sg_get_unaligned_be24(rbBuff + 1);
        buf_granul = (uint8_t)rbBuff[0];
#if 0
        printf("READ BUFFER reports: %02x %02x %02x %02x\n",
               rbBuff[0], rbBuff[1], rbBuff[2], rbBuff[3]);
#endif
        if (verbose)
                printf("READ BUFFER reports: buffer capacity=%d, offset "
                       "boundary=%d\n", buf_capacity, buf_granul);
        return 0;
}

static int
mymemcmp (uint8_t *bf1, uint8_t *bf2, int len)
{
        int df;
        for (df = 0; df < len; df++)
                if (bf1[df] != bf2[df]) return df;
        return 0;
}

/* return 0 if good, else 2222 */
static int
do_checksum(int *buf, int len, bool quiet)
{
        int sum = base;
        int i; int rln = len;
        for (i = 0; i < len/BPI; i++)
                sum += buf[i];
        while (rln%BPI) sum += ((char*)buf)[--rln];
        if (sum != 0x12345678) {
                if (!quiet) printf ("sg_test_rwbuf: Checksum error (sz=%i):"
                                    " %08x\n", len, sum);
                if (cmpbuf && !quiet) {
                        int diff = mymemcmp (cmpbuf, (uint8_t*)buf,
                                             len);
                        printf ("Differ at pos %i/%i:\n", diff, len);
                        for (i = 0; i < 24 && i+diff < len; i++)
                                printf (" %02x", cmpbuf[i+diff]);
                        printf ("\n");
                        for (i = 0; i < 24 && i+diff < len; i++)
                                printf (" %02x",
                                        ((uint8_t*)buf)[i+diff]);
                        printf ("\n");
                }
                return 2222;
        }
        else {
                if (verbose > 1)
                        printf("Checksum value: 0x%x\n", sum);
                return 0;
        }
}

void do_fill_buffer (int *buf, int len)
{
        int sum;
        int i; int rln = len;
        srand (time (0));
    retry:
        if (len >= BPI)
                base = 0x12345678 + rand ();
        else
                base = 0x12345678 + (char) rand ();
        sum = base;
        for (i = 0; i < len/BPI - 1; i++)
        {
                /* we rely on rand() giving full range of int */
                buf[i] = rand ();
                sum += buf[i];
        }
        while (rln%BPI)
        {
                ((char*)buf)[--rln] = rand ();
                sum += ((char*)buf)[rln];
        }
        if (len >= BPI) buf[len/BPI - 1] = 0x12345678 - sum;
        else ((char*)buf)[0] = 0x12345678 + ((char*)buf)[0] - sum;
        if (do_checksum(buf, len, true)) {
                if (len < BPI) goto retry;
                printf ("sg_test_rwbuf: Memory corruption?\n");
                exit (1);
        }
        if (cmpbuf) memcpy (cmpbuf, (char*)buf, len);
}


int read_buffer (int sg_fd, unsigned ssize)
{
        int res;
        uint8_t rb_cdb[] = {READ_BUFFER, 0, 0, 0, 0, 0, 0, 0, 0, 0};
        int bufSize = ssize + addread;
        uint8_t * free_rbBuff = NULL;
        uint8_t * rbBuff = (uint8_t *)sg_memalign(bufSize, 0, &free_rbBuff,
                                                  false);
        uint8_t sense_buffer[32];
        struct sg_io_hdr io_hdr;

        if (NULL == rbBuff)
                return -1;
        rb_cdb[1] = RWB_MODE_DATA;
        sg_put_unaligned_be24((uint32_t)bufSize, rb_cdb + 6);
        memset(&io_hdr, 0, sizeof(struct sg_io_hdr));
        io_hdr.interface_id = 'S';
        io_hdr.cmd_len = sizeof(rb_cdb);
        io_hdr.mx_sb_len = sizeof(sense_buffer);
        io_hdr.dxfer_direction = SG_DXFER_FROM_DEV;
        io_hdr.dxfer_len = bufSize;
        io_hdr.dxferp = rbBuff;
        io_hdr.cmdp = rb_cdb;
        io_hdr.sbp = sense_buffer;
        io_hdr.pack_id = 2;
        io_hdr.timeout = 60000;     /* 60000 millisecs == 60 seconds */
        if (verbose) {
                char b[128];

                pr2serr("    read buffer [mode data] cdb: %s\n",
                        sg_get_command_str(rb_cdb, (int)sizeof(rb_cdb), false,
                                           sizeof(b), b));
        }

        if (ioctl(sg_fd, SG_IO, &io_hdr) < 0) {
                perror(ME "SG_IO READ BUFFER data error");
                free(rbBuff);
                return -1;
        }
        /* now for the error processing */
        res = sg_err_category3(&io_hdr);
        switch (res) {
        case SG_LIB_CAT_RECOVERED:
            sg_chk_n_print3("READ BUFFER data, continuing", &io_hdr, true);
#if defined(__GNUC__)
#if (__GNUC__ >= 7)
            __attribute__((fallthrough));
            /* FALL THROUGH */
#endif
#endif
        case SG_LIB_CAT_CLEAN:
                break;
        default: /* won't bother decoding other categories */
                sg_chk_n_print3("READ BUFFER data error", &io_hdr, true);
                free(rbBuff);
                return res;
        }

        res = do_checksum((int*)rbBuff, ssize, false);
        if (free_rbBuff)
                free(free_rbBuff);
        return res;
}

int write_buffer (int sg_fd, unsigned ssize)
{
        uint8_t wb_cdb[] = {WRITE_BUFFER, 0, 0, 0, 0, 0, 0, 0, 0, 0};
        int bufSize = ssize + addwrite;
        uint8_t * free_wbBuff = NULL;
        uint8_t * wbBuff = (uint8_t *)sg_memalign(bufSize, 0, &free_wbBuff,
                                                  false);
        uint8_t sense_buffer[32];
        struct sg_io_hdr io_hdr;
        int res;

        if (NULL == wbBuff)
                return -1;
        memset(wbBuff, 0, bufSize);
        do_fill_buffer ((int*)wbBuff, ssize);
        wb_cdb[1] = RWB_MODE_DATA;
        sg_put_unaligned_be24((uint32_t)bufSize, wb_cdb + 6);
        memset(&io_hdr, 0, sizeof(struct sg_io_hdr));
        io_hdr.interface_id = 'S';
        io_hdr.cmd_len = sizeof(wb_cdb);
        io_hdr.mx_sb_len = sizeof(sense_buffer);
        io_hdr.dxfer_direction = SG_DXFER_TO_DEV;
        io_hdr.dxfer_len = bufSize;
        io_hdr.dxferp = wbBuff;
        io_hdr.cmdp = wb_cdb;
        io_hdr.sbp = sense_buffer;
        io_hdr.pack_id = 1;
        io_hdr.timeout = 60000;     /* 60000 millisecs == 60 seconds */
        if (verbose) {
                char b[128];

                pr2serr("    write buffer [mode data] cdb: %s\n",
                        sg_get_command_str(wb_cdb, (int)sizeof(wb_cdb), false,
                                           sizeof(b), b));
        }

        if (ioctl(sg_fd, SG_IO, &io_hdr) < 0) {
                perror(ME "SG_IO WRITE BUFFER data error");
                free(wbBuff);
                return -1;
        }
        /* now for the error processing */
        res = sg_err_category3(&io_hdr);
        switch (res) {
        case SG_LIB_CAT_RECOVERED:
            sg_chk_n_print3("WRITE BUFFER data, continuing", &io_hdr, true);
#if defined(__GNUC__)
#if (__GNUC__ >= 7)
            __attribute__((fallthrough));
            /* FALL THROUGH */
#endif
#endif
        case SG_LIB_CAT_CLEAN:
                break;
        default: /* won't bother decoding other categories */
                sg_chk_n_print3("WRITE BUFFER data error", &io_hdr, true);
                free(wbBuff);
                return res;
        }
        if (free_wbBuff)
                free(free_wbBuff);
        return res;
}

void usage ()
{
        printf ("Usage: sg_test_rwbuf [--addrd=AR] [--addwr=AW] [--help] "
                "[--quick]\n");
        printf ("                     --size=SZ [--times=NUM] [--verbose] "
                "[--version]\n"
                "                     DEVICE\n"
                " or\n"
                "       sg_test_rwbuf DEVICE SZ [AW] [AR]\n");
        printf ("  where:\n"
                "    --addrd=AR|-r    extra bytes to fetch during READ "
                "BUFFER\n"
                "    --addwr=AW|-w    extra bytes to send to WRITE BUFFER\n"
                "    --help|-l        output this usage message then exit\n"
                "    --quick|-q       output read buffer size then exit\n"
                "    --size=SZ|-s     size of buffer (in bytes) to write "
                "then read back\n"
                "    --times=NUM|-t   number of times to run test "
                "(default 1)\n"
                "    --verbose|-v     increase verbosity of output\n"
                "    --version|-V     output version then exit\n");
        printf ("\nWARNING: If you access the device at the same time, e.g. "
                "because it's a\n");
        printf (" mounted hard disk, the device's buffer may be used by the "
                "device itself\n");
        printf (" for other data at the same time, and overwriting it may or "
                "may not\n");
        printf (" cause data corruption!\n");
        printf ("(c) Douglas Gilbert, Kurt Garloff, 2000-2007, GNU GPL\n");
}


int main (int argc, char * argv[])
{
        bool verbose_given = false;
        bool version_given = false;
        int sg_fd, res;
        const char * device_name = NULL;
        int times = 1;
        int ret = 0;
        int k = 0;
        int err;

        while (1) {
                int option_index = 0;
                int c;

                c = getopt_long(argc, argv, "hqr:s:t:w:vV",
                                long_options, &option_index);
                if (c == -1)
                        break;

                switch (c) {
                case 'h':
                        usage();
                        return 0;
                case 'q':
                        do_quick = true;
                        break;
                case 'r':
                        addread = sg_get_num(optarg);
                        if (-1 == addread) {
                                pr2serr("bad argument to '--addrd'\n");
                                return SG_LIB_SYNTAX_ERROR;
                        }
                        break;
                case 's':
                        size = sg_get_num(optarg);
                        if (-1 == size) {
                                pr2serr("bad argument to '--size'\n");
                                return SG_LIB_SYNTAX_ERROR;
                        }
                        break;
                case 't':
                        times = sg_get_num(optarg);
                        if (-1 == times) {
                                pr2serr("bad argument to '--times'\n");
                                return SG_LIB_SYNTAX_ERROR;
                        }
                        break;
                case 'v':
                        verbose_given = true;
                        verbose++;
                        break;
                case 'V':
                        version_given = true;
                        break;
                case 'w':
                        addwrite = sg_get_num(optarg);
                        if (-1 == addwrite) {
                                pr2serr("bad argument to '--addwr'\n");
                                return SG_LIB_SYNTAX_ERROR;
                        }
                        break;
                default:
                        usage();
                        return SG_LIB_SYNTAX_ERROR;
                }
        }
        if (optind < argc) {
                if (NULL == device_name) {
                        device_name = argv[optind];
                        ++optind;
                }
        }
        if (optind < argc) {
                if (-1 == size) {
                        size = sg_get_num(argv[optind]);
                        if (-1 == size) {
                                pr2serr("bad <sz>\n");
                                usage();
                                return SG_LIB_SYNTAX_ERROR;
                        }
                        if (++optind < argc) {
                                addwrite = sg_get_num(argv[optind]);
                                if (-1 == addwrite) {
                                        pr2serr("bad [addwr]\n");
                                        usage();
                                        return SG_LIB_SYNTAX_ERROR;
                                }
                                if (++optind < argc) {
                                        addread = sg_get_num(argv[optind]);
                                        if (-1 == addread) {
                                                pr2serr("bad [addrd]\n");
                                                usage();
                                                return SG_LIB_SYNTAX_ERROR;
                                        }
                                }
                        }

                }
                if (optind < argc) {
                        for (; optind < argc; ++optind)
                                pr2serr("Unexpected extra argument" ": %s\n",
                                        argv[optind]);
                        usage();
                        return SG_LIB_SYNTAX_ERROR;
                }
        }

#ifdef DEBUG
        pr2serr("In DEBUG mode, ");
        if (verbose_given && version_given) {
                pr2serr("but override: '-vV' given, zero verbose and "
                        "continue\n");
                verbose_given = false;
                version_given = false;
                verbose = 0;
        } else if (! verbose_given) {
                pr2serr("set '-vv'\n");
                verbose = 2;
        } else
                pr2serr("keep verbose=%d\n", verbose);
#else
        if (verbose_given && version_given)
                pr2serr("Not in DEBUG mode, so '-vV' has no special action\n");
#endif
        if (version_given) {
                pr2serr(ME "version: %s\n", version_str);
                return 0;
        }

        if (NULL == device_name) {
                pr2serr("no device name given\n");
                usage();
                return SG_LIB_SYNTAX_ERROR;
        }
        if ((size <= 0) && (! do_quick)) {
                pr2serr("must give '--size' or '--quick' options or <sz> "
                        "argument\n");
                usage();
                return SG_LIB_SYNTAX_ERROR;
        }

        sg_fd = open(device_name, O_RDWR | O_NONBLOCK);
        if (sg_fd < 0) {
                err = errno;
                perror("sg_test_rwbuf: open error");
                return sg_convert_errno(err);
        }
        ret = find_out_about_buffer(sg_fd);
        if (ret)
                goto err_out;
        if (do_quick) {
                printf ("READ BUFFER read descriptor reports a buffer "
                        "of %d bytes [%d KiB]\n", buf_capacity,
                        buf_capacity / 1024);
                goto err_out;
        }
        if (size > buf_capacity) {
                pr2serr (ME "sz=%i > buf_capacity=%i\n", size, buf_capacity);
                ret = SG_LIB_CAT_OTHER;
                goto err_out;
        }

        cmpbuf = (uint8_t *)sg_memalign(size, 0, &free_cmpbuf, false);
        for (k = 0; k < times; ++k) {
                ret = write_buffer (sg_fd, size);
                if (ret) {
                        goto err_out;
                }
                ret = read_buffer (sg_fd, size);
                if (ret) {
                        if (2222 == ret)
                                ret = SG_LIB_CAT_MALFORMED;
                        goto err_out;
                }
        }

err_out:
        if (free_cmpbuf)
                free(free_cmpbuf);
        res = close(sg_fd);
        if (res < 0) {
                perror(ME "close error");
                if (0 == ret)
                        ret = sg_convert_errno(errno);
        }
        if ((0 == ret) && (! do_quick))
                printf ("Success\n");
        else if (times > 1)
                printf ("Failed after %d successful cycles\n", k);
        return (ret >= 0) ? ret : SG_LIB_CAT_OTHER;
}
