/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1991, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Keith Muller of the University of California, San Diego and Lance
 * Visser of Convex Computer Corporation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>

#include "dd.h"
#include "extern.h"

static int      c_arg(const void *, const void *);
static int      c_conv(const void *, const void *);
static int      c_iflag(const void *, const void *);
static int      c_oflag(const void *, const void *);
static void     f_bs(char *);
static void     f_cbs(char *);
static void     f_conv(char *);
static void     f_count(char *);
static void     f_files(char *);
static void     f_fillchar(char *);
static void     f_ibs(char *);
static void     f_if(char *);
static void     f_iflag(char *);
static void     f_obs(char *);
static void     f_of(char *);
static void     f_oflag(char *);
static void     f_seek(char *);
static void     f_skip(char *);
static void     f_speed(char *);
static void     f_status(char *);
static uintmax_t get_num(const char *);
static off_t    get_off_t(const char *);

static const struct arg {
        const char *name;
        void (*f)(char *);
        uint64_t set, noset;
} args[] = {
        { "bs",         f_bs,           C_BS,    C_BS|C_IBS|C_OBS|C_OSYNC },
        { "cbs",        f_cbs,          C_CBS,   C_CBS },
        { "conv",       f_conv,         0,       0 },
        { "count",      f_count,        C_COUNT, C_COUNT },
        { "files",      f_files,        C_FILES, C_FILES },
        { "fillchar",   f_fillchar,     C_FILL,  C_FILL },
        { "ibs",        f_ibs,          C_IBS,   C_BS|C_IBS },
        { "if",         f_if,           C_IF,    C_IF },
        { "iflag",      f_iflag,        0,       0 },
        { "iseek",      f_skip,         C_SKIP,  C_SKIP },
        { "obs",        f_obs,          C_OBS,   C_BS|C_OBS },
        { "of",         f_of,           C_OF,    C_OF },
        { "oflag",      f_oflag,        0,       0 },
        { "oseek",      f_seek,         C_SEEK,  C_SEEK },
        { "seek",       f_seek,         C_SEEK,  C_SEEK },
        { "skip",       f_skip,         C_SKIP,  C_SKIP },
        { "speed",      f_speed,        0,       0 },
        { "status",     f_status,       C_STATUS,C_STATUS },
};

static char *oper;

/*
 * args -- parse JCL syntax of dd.
 */
void
jcl(char **argv)
{
        struct arg *ap, tmp;
        char *arg;

        in.dbsz = out.dbsz = 512;

        while ((oper = *++argv) != NULL) {
                if ((oper = strdup(oper)) == NULL)
                        errx(1, "unable to allocate space for the argument \"%s\"", *argv);
                if ((arg = strchr(oper, '=')) == NULL)
                        errx(1, "unknown operand %s", oper);
                *arg++ = '\0';
                if (!*arg)
                        errx(1, "no value specified for %s", oper);
                tmp.name = oper;
                if (!(ap = (struct arg *)bsearch(&tmp, args,
                    sizeof(args)/sizeof(struct arg), sizeof(struct arg),
                    c_arg)))
                        errx(1, "unknown operand %s", tmp.name);
                if (ddflags & ap->noset)
                        errx(1, "%s: illegal argument combination or already set",
                            tmp.name);
                ddflags |= ap->set;
                ap->f(arg);
        }

        /* Final sanity checks. */

        if (ddflags & C_BS) {
                /*
                 * Bs is turned off by any conversion -- we assume the user
                 * just wanted to set both the input and output block sizes
                 * and didn't want the bs semantics, so we don't warn.
                 */
                if (ddflags & (C_BLOCK | C_LCASE | C_SWAB | C_UCASE |
                    C_UNBLOCK))
                        ddflags &= ~C_BS;

                /* Bs supersedes ibs and obs. */
                if (ddflags & C_BS && ddflags & (C_IBS | C_OBS))
                        warnx("bs supersedes ibs and obs");
        }

        /*
         * Ascii/ebcdic and cbs implies block/unblock.
         * Block/unblock requires cbs and vice-versa.
         */
        if (ddflags & (C_BLOCK | C_UNBLOCK)) {
                if (!(ddflags & C_CBS))
                        errx(1, "record operations require cbs");
                if (cbsz == 0)
                        errx(1, "cbs cannot be zero");
                cfunc = ddflags & C_BLOCK ? block : unblock;
        } else if (ddflags & C_CBS) {
                if (ddflags & (C_ASCII | C_EBCDIC)) {
                        if (ddflags & C_ASCII) {
                                ddflags |= C_UNBLOCK;
                                cfunc = unblock;
                        } else {
                                ddflags |= C_BLOCK;
                                cfunc = block;
                        }
                } else
                        errx(1, "cbs meaningless if not doing record operations");
        } else
                cfunc = def;
}

static int
c_arg(const void *a, const void *b)
{

        return (strcmp(((const struct arg *)a)->name,
            ((const struct arg *)b)->name));
}

static void
f_bs(char *arg)
{
        uintmax_t res;

        res = get_num(arg);
        if (res < 1 || res > SSIZE_MAX)
                errx(1, "bs must be between 1 and %zd", (ssize_t)SSIZE_MAX);
        in.dbsz = out.dbsz = (size_t)res;
}

static void
f_cbs(char *arg)
{
        uintmax_t res;

        res = get_num(arg);
        if (res < 1 || res > SSIZE_MAX)
                errx(1, "cbs must be between 1 and %zd", (ssize_t)SSIZE_MAX);
        cbsz = (size_t)res;
}

static void
f_count(char *arg)
{
        uintmax_t res;

        res = get_num(arg);
        if (res == UINTMAX_MAX)
                errc(1, ERANGE, "%s", oper);
        if (res == 0)
                cpy_cnt = UINTMAX_MAX;
        else
                cpy_cnt = res;
}

static void
f_files(char *arg)
{

        files_cnt = get_num(arg);
        if (files_cnt < 1)
                errx(1, "files must be between 1 and %zu", SIZE_MAX);
}

static void
f_fillchar(char *arg)
{

        if (strlen(arg) != 1)
                errx(1, "need exactly one fill char");

        fill_char = arg[0];
}

static void
f_ibs(char *arg)
{
        uintmax_t res;

        if (!(ddflags & C_BS)) {
                res = get_num(arg);
                if (res < 1 || res > SSIZE_MAX)
                        errx(1, "ibs must be between 1 and %zd",
                            (ssize_t)SSIZE_MAX);
                in.dbsz = (size_t)res;
        }
}

static void
f_if(char *arg)
{

        in.name = arg;
}

static const struct iflag {
        const char *name;
        uint64_t set, noset;
} ilist[] = {
        { "direct",     C_IDIRECT,      0 },
        { "fullblock",  C_IFULLBLOCK,   C_SYNC },
};

static void
f_iflag(char *arg)
{
        struct iflag *ip, tmp;

        while (arg != NULL) {
                tmp.name = strsep(&arg, ",");
                ip = bsearch(&tmp, ilist, nitems(ilist), sizeof(struct iflag),
                    c_iflag);
                if (ip == NULL)
                        errx(1, "unknown iflag %s", tmp.name);
                if (ddflags & ip->noset)
                        errx(1, "%s: illegal conversion combination", tmp.name);
                ddflags |= ip->set;
        }
}

static int
c_iflag(const void *a, const void *b)
{

        return (strcmp(((const struct iflag *)a)->name,
            ((const struct iflag *)b)->name));
}

static void
f_obs(char *arg)
{
        uintmax_t res;

        if (!(ddflags & C_BS)) {
                res = get_num(arg);
                if (res < 1 || res > SSIZE_MAX)
                        errx(1, "obs must be between 1 and %zd",
                            (ssize_t)SSIZE_MAX);
                out.dbsz = (size_t)res;
        }
}

static void
f_of(char *arg)
{

        out.name = arg;
}

static void
f_seek(char *arg)
{

        out.offset = get_off_t(arg);
}

static void
f_skip(char *arg)
{

        in.offset = get_off_t(arg);
}

static void
f_speed(char *arg)
{

        speed = get_num(arg);
}

static void
f_status(char *arg)
{

        if (strcmp(arg, "none") == 0)
                ddflags |= C_NOINFO;
        else if (strcmp(arg, "noxfer") == 0)
                ddflags |= C_NOXFER;
        else if (strcmp(arg, "progress") == 0)
                ddflags |= C_PROGRESS;
        else
                errx(1, "unknown status %s", arg);
}
 
static const struct conv {
        const char *name;
        uint64_t set, noset;
        const u_char *ctab;
} clist[] = {
        { "ascii",      C_ASCII,        C_EBCDIC,       e2a_POSIX },
        { "block",      C_BLOCK,        C_UNBLOCK,      NULL },
        { "ebcdic",     C_EBCDIC,       C_ASCII,        a2e_POSIX },
        { "fdatasync",  C_FDATASYNC,    0,              NULL },
        { "fsync",      C_FSYNC,        0,              NULL },
        { "ibm",        C_EBCDIC,       C_ASCII,        a2ibm_POSIX },
        { "lcase",      C_LCASE,        C_UCASE,        NULL },
        { "noerror",    C_NOERROR,      0,              NULL },
        { "notrunc",    C_NOTRUNC,      0,              NULL },
        { "oldascii",   C_ASCII,        C_EBCDIC,       e2a_32V },
        { "oldebcdic",  C_EBCDIC,       C_ASCII,        a2e_32V },
        { "oldibm",     C_EBCDIC,       C_ASCII,        a2ibm_32V },
        { "osync",      C_OSYNC,        C_BS,           NULL },
        { "pareven",    C_PAREVEN,      C_PARODD|C_PARSET|C_PARNONE, NULL},
        { "parnone",    C_PARNONE,      C_PARODD|C_PARSET|C_PAREVEN, NULL},
        { "parodd",     C_PARODD,       C_PAREVEN|C_PARSET|C_PARNONE, NULL},
        { "parset",     C_PARSET,       C_PARODD|C_PAREVEN|C_PARNONE, NULL},
        { "sparse",     C_SPARSE,       0,              NULL },
        { "swab",       C_SWAB,         0,              NULL },
        { "sync",       C_SYNC,         C_IFULLBLOCK,   NULL },
        { "ucase",      C_UCASE,        C_LCASE,        NULL },
        { "unblock",    C_UNBLOCK,      C_BLOCK,        NULL },
};

static void
f_conv(char *arg)
{
        struct conv *cp, tmp;

        while (arg != NULL) {
                tmp.name = strsep(&arg, ",");
                cp = bsearch(&tmp, clist, nitems(clist), sizeof(struct conv),
                    c_conv);
                if (cp == NULL)
                        errx(1, "unknown conversion %s", tmp.name);
                if (ddflags & cp->noset)
                        errx(1, "%s: illegal conversion combination", tmp.name);
                ddflags |= cp->set;
                if (cp->ctab)
                        ctab = cp->ctab;
        }
}

static int
c_conv(const void *a, const void *b)
{

        return (strcmp(((const struct conv *)a)->name,
            ((const struct conv *)b)->name));
}

static const struct oflag {
        const char *name;
        uint64_t set;
} olist[] = {
        { "direct",     C_ODIRECT },
        { "fsync",      C_OFSYNC },
        { "sync",       C_OFSYNC },
};

static void
f_oflag(char *arg)
{
        struct oflag *op, tmp;

        while (arg != NULL) {
                tmp.name = strsep(&arg, ",");
                op = bsearch(&tmp, olist, nitems(olist), sizeof(struct oflag),
                    c_oflag);
                if (op == NULL)
                        errx(1, "unknown open flag %s", tmp.name);
                ddflags |= op->set;
        }
}

static int
c_oflag(const void *a, const void *b)
{

        return (strcmp(((const struct oflag *)a)->name,
            ((const struct oflag *)b)->name));
}

static intmax_t
postfix_to_mult(const char expr)
{
        intmax_t mult;

        mult = 0;
        switch (expr) {
        case 'B':
        case 'b':
                mult = 512;
                break;
        case 'K':
        case 'k':
                mult = 1 << 10;
                break;
        case 'M':
        case 'm':
                mult = 1 << 20;
                break;
        case 'G':
        case 'g':
                mult = 1 << 30;
                break;
        case 'T':
        case 't':
                mult = (uintmax_t)1 << 40;
                break;
        case 'P':
        case 'p':
                mult = (uintmax_t)1 << 50;
                break;
        case 'W':
        case 'w':
                mult = sizeof(int);
                break;
        }

        return (mult);
}

/*
 * Convert an expression of the following forms to a uintmax_t.
 *      1) A positive decimal number.
 *      2) A positive decimal number followed by a 'b' or 'B' (mult by 512).
 *      3) A positive decimal number followed by a 'k' or 'K' (mult by 1 << 10).
 *      4) A positive decimal number followed by a 'm' or 'M' (mult by 1 << 20).
 *      5) A positive decimal number followed by a 'g' or 'G' (mult by 1 << 30).
 *      6) A positive decimal number followed by a 't' or 'T' (mult by 1 << 40).
 *      7) A positive decimal number followed by a 'p' or 'P' (mult by 1 << 50).
 *      8) A positive decimal number followed by a 'w' or 'W' (mult by sizeof int).
 *      9) Two or more positive decimal numbers (with/without [BbKkMmGgWw])
 *         separated by 'x' or 'X' (also '*' for backwards compatibility),
 *         specifying the product of the indicated values.
 */
static uintmax_t
get_num(const char *val)
{
        uintmax_t num, mult, prevnum;
        char *expr;

        errno = 0;
        num = strtoumax(val, &expr, 0);
        if (expr == val)                        /* No valid digits. */
                errx(1, "%s: invalid numeric value", oper);
        if (errno != 0)
                err(1, "%s", oper);

        mult = postfix_to_mult(*expr);

        if (mult != 0) {
                prevnum = num;
                num *= mult;
                /* Check for overflow. */
                if (num / mult != prevnum)
                        goto erange;
                expr++;
        }

        switch (*expr) {
                case '\0':
                        break;
                case '*':                       /* Backward compatible. */
                case 'X':
                case 'x':
                        mult = get_num(expr + 1);
                        prevnum = num;
                        num *= mult;
                        if (num / mult == prevnum)
                                break;
erange:
                        errx(1, "%s: %s", oper, strerror(ERANGE));
                default:
                        errx(1, "%s: illegal numeric value", oper);
        }
        return (num);
}

/*
 * Convert an expression of the following forms to an off_t.  This is the
 * same as get_num(), but it uses signed numbers.
 *
 * The major problem here is that an off_t may not necessarily be a intmax_t.
 */
static off_t
get_off_t(const char *val)
{
        intmax_t num, mult, prevnum;
        char *expr;

        errno = 0;
        num = strtoimax(val, &expr, 0);
        if (expr == val)                        /* No valid digits. */
                errx(1, "%s: invalid numeric value", oper);
        if (errno != 0)
                err(1, "%s", oper);

        mult = postfix_to_mult(*expr);

        if (mult != 0) {
                prevnum = num;
                num *= mult;
                /* Check for overflow. */
                if ((prevnum > 0) != (num > 0) || num / mult != prevnum)
                        goto erange;
                expr++;
        }

        switch (*expr) {
                case '\0':
                        break;
                case '*':                       /* Backward compatible. */
                case 'X':
                case 'x':
                        mult = (intmax_t)get_off_t(expr + 1);
                        prevnum = num;
                        num *= mult;
                        if ((prevnum > 0) == (num > 0) && num / mult == prevnum)
                                break;
erange:
                        errx(1, "%s: %s", oper, strerror(ERANGE));
                default:
                        errx(1, "%s: illegal numeric value", oper);
        }
        return (num);
}