/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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 <sys/capsicum.h>
#include <sys/conf.h>
#include <sys/ioctl.h>
#include <sys/stat.h>

#include <capsicum_helpers.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "hexdump.h"

enum _vflag vflag = FIRST;

static off_t address;                   /* address/offset in stream */
static off_t eaddress;                  /* end address */

static void print(PR *, u_char *);
static void noseek(void);

void
display(void)
{
        FS *fs;
        FU *fu;
        PR *pr;
        int cnt;
        u_char *bp;
        off_t saveaddress;
        u_char savech, *savebp;

        savech = 0;
        while ((bp = get()))
            for (fs = fshead, savebp = bp, saveaddress = address; fs;
                fs = fs->nextfs, bp = savebp, address = saveaddress)
                    for (fu = fs->nextfu; fu; fu = fu->nextfu) {
                        if (fu->flags&F_IGNORE)
                                break;
                        for (cnt = fu->reps; cnt; --cnt)
                            for (pr = fu->nextpr; pr; address += pr->bcnt,
                                bp += pr->bcnt, pr = pr->nextpr) {
                                    if (eaddress && address >= eaddress &&
                                        !(pr->flags & (F_TEXT|F_BPAD)))
                                            bpad(pr);
                                    if (cnt == 1 && pr->nospace) {
                                        savech = *pr->nospace;
                                        *pr->nospace = '\0';
                                    }
                                    print(pr, bp);
                                    if (cnt == 1 && pr->nospace)
                                        *pr->nospace = savech;
                            }
                    }
        if (endfu) {
                /*
                 * If eaddress not set, error or file size was multiple of
                 * blocksize, and no partial block ever found.
                 */
                if (!eaddress) {
                        if (!address)
                                return;
                        eaddress = address;
                }
                for (pr = endfu->nextpr; pr; pr = pr->nextpr)
                        switch(pr->flags) {
                        case F_ADDRESS:
                                (void)printf(pr->fmt, (quad_t)eaddress);
                                break;
                        case F_TEXT:
                                (void)printf("%s", pr->fmt);
                                break;
                        }
        }
}

static void
print(PR *pr, u_char *bp)
{
        long double ldbl;
           double f8;
            float f4;
          int16_t s2;
          int32_t s4;
          int64_t s8;
        u_int16_t u2;
        u_int32_t u4;
        u_int64_t u8;

        switch(pr->flags) {
        case F_ADDRESS:
                (void)printf(pr->fmt, (quad_t)address);
                break;
        case F_BPAD:
                (void)printf(pr->fmt, "");
                break;
        case F_C:
                conv_c(pr, bp, eaddress ? eaddress - address :
                    blocksize - address % blocksize);
                break;
        case F_CHAR:
                (void)printf(pr->fmt, *bp);
                break;
        case F_DBL:
                switch(pr->bcnt) {
                case 4:
                        bcopy(bp, &f4, sizeof(f4));
                        (void)printf(pr->fmt, f4);
                        break;
                case 8:
                        bcopy(bp, &f8, sizeof(f8));
                        (void)printf(pr->fmt, f8);
                        break;
                default:
                        if (pr->bcnt == sizeof(long double)) {
                                bcopy(bp, &ldbl, sizeof(ldbl));
                                (void)printf(pr->fmt, ldbl);
                        }
                        break;
                }
                break;
        case F_INT:
                switch(pr->bcnt) {
                case 1:
                        (void)printf(pr->fmt, (quad_t)(signed char)*bp);
                        break;
                case 2:
                        bcopy(bp, &s2, sizeof(s2));
                        (void)printf(pr->fmt, (quad_t)s2);
                        break;
                case 4:
                        bcopy(bp, &s4, sizeof(s4));
                        (void)printf(pr->fmt, (quad_t)s4);
                        break;
                case 8:
                        bcopy(bp, &s8, sizeof(s8));
                        (void)printf(pr->fmt, s8);
                        break;
                }
                break;
        case F_P:
                (void)printf(pr->fmt, isprint(*bp) ? *bp : '.');
                break;
        case F_STR:
                (void)printf(pr->fmt, (char *)bp);
                break;
        case F_TEXT:
                (void)printf("%s", pr->fmt);
                break;
        case F_U:
                conv_u(pr, bp);
                break;
        case F_UINT:
                switch(pr->bcnt) {
                case 1:
                        (void)printf(pr->fmt, (u_quad_t)*bp);
                        break;
                case 2:
                        bcopy(bp, &u2, sizeof(u2));
                        (void)printf(pr->fmt, (u_quad_t)u2);
                        break;
                case 4:
                        bcopy(bp, &u4, sizeof(u4));
                        (void)printf(pr->fmt, (u_quad_t)u4);
                        break;
                case 8:
                        bcopy(bp, &u8, sizeof(u8));
                        (void)printf(pr->fmt, u8);
                        break;
                }
                break;
        }
}

void
bpad(PR *pr)
{
        static char const *spec = " -0+#";
        char *p1, *p2;

        /*
         * Remove all conversion flags; '-' is the only one valid
         * with %s, and it's not useful here.
         */
        pr->flags = F_BPAD;
        pr->cchar[0] = 's';
        pr->cchar[1] = '\0';
        for (p1 = pr->fmt; *p1 != '%'; ++p1);
        for (p2 = ++p1; *p1 && strchr(spec, *p1); ++p1);
        while ((*p2++ = *p1++));
}

static char **_argv;

u_char *
get(void)
{
        static int ateof = 1;
        static u_char *curp, *savp;
        int n;
        int need, nread;
        int valid_save = 0;
        u_char *tmpp;

        if (!curp) {
                if ((curp = calloc(1, blocksize)) == NULL)
                        err(1, NULL);
                if ((savp = calloc(1, blocksize)) == NULL)
                        err(1, NULL);
        } else {
                tmpp = curp;
                curp = savp;
                savp = tmpp;
                address += blocksize;
                valid_save = 1;
        }
        for (need = blocksize, nread = 0;;) {
                /*
                 * if read the right number of bytes, or at EOF for one file,
                 * and no other files are available, zero-pad the rest of the
                 * block and set the end flag.
                 */
                if (!length || (ateof && !next((char **)NULL))) {
                        if (odmode && skip > 0)
                                errx(1, "cannot skip past end of input");
                        if (need == blocksize)
                                return((u_char *)NULL);
                        /*
                         * XXX bcmp() is not quite right in the presence
                         * of multibyte characters.
                         */
                        if (need == 0 && vflag != ALL &&
                            valid_save && 
                            bcmp(curp, savp, nread) == 0) {
                                if (vflag != DUP) {
                                        (void)printf("*\n");
                                        (void)fflush(stdout);
                                }
                                return((u_char *)NULL);
                        }
                        bzero((char *)curp + nread, need);
                        eaddress = address + nread;
                        return(curp);
                }
                n = fread((char *)curp + nread, sizeof(u_char),
                    length == -1 ? need : MIN(length, need), stdin);
                if (!n) {
                        if (ferror(stdin))
                                warn("%s", _argv[-1]);
                        ateof = 1;
                        continue;
                }
                ateof = 0;
                if (length != -1)
                        length -= n;
                if (!(need -= n)) {
                        /*
                         * XXX bcmp() is not quite right in the presence
                         * of multibyte characters.
                         */
                        if (vflag == ALL || vflag == FIRST ||
                            valid_save == 0 ||
                            bcmp(curp, savp, blocksize) != 0) {
                                if (vflag == DUP || vflag == FIRST)
                                        vflag = WAIT;
                                return(curp);
                        }
                        if (vflag == WAIT) {
                                (void)printf("*\n");
                                (void)fflush(stdout);
                        }
                        vflag = DUP;
                        address += blocksize;
                        need = blocksize;
                        nread = 0;
                }
                else
                        nread += n;
        }
}

size_t
peek(u_char *buf, size_t nbytes)
{
        size_t n, nread;
        int c;

        if (length != -1 && nbytes > (unsigned int)length)
                nbytes = length;
        nread = 0;
        while (nread < nbytes && (c = getchar()) != EOF) {
                *buf++ = c;
                nread++;
        }
        n = nread;
        while (n-- > 0) {
                c = *--buf;
                ungetc(c, stdin);
        }
        return (nread);
}

int
next(char **argv)
{
        static int done;
        int statok;

        if (argv) {
                _argv = argv;
                return(1);
        }
        for (;;) {
                if (*_argv) {
                        done = 1;
                        if (!(freopen(*_argv, "r", stdin))) {
                                warn("%s", *_argv);
                                exitval = 1;
                                ++_argv;
                                continue;
                        }
                        statok = 1;
                } else {
                        if (done++)
                                return(0);
                        statok = 0;
                }

                if (caph_limit_stream(fileno(stdin), CAPH_READ) < 0)
                        err(1, "unable to restrict %s",
                            statok ? *_argv : "stdin");

                /*
                 * We've opened our last input file; enter capsicum sandbox.
                 */
                if (statok == 0 || *(_argv + 1) == NULL) {
                        if (caph_enter() < 0)
                                err(1, "unable to enter capability mode");
                }

                if (skip)
                        doskip(statok ? *_argv : "stdin", statok);
                if (*_argv)
                        ++_argv;
                if (!skip)
                        return(1);
        }
        /* NOTREACHED */
}

void
doskip(const char *fname, int statok)
{
        int type;
        struct stat sb;

        if (statok) {
                if (fstat(fileno(stdin), &sb))
                        err(1, "%s", fname);
                if (S_ISREG(sb.st_mode) && skip > sb.st_size && sb.st_size > 0) {
                        address += sb.st_size;
                        skip -= sb.st_size;
                        return;
                }
        }
        if (!statok || S_ISFIFO(sb.st_mode) || S_ISSOCK(sb.st_mode) || \
            (S_ISREG(sb.st_mode) && sb.st_size == 0)) {
                noseek();
                return;
        }
        if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) {
                if (ioctl(fileno(stdin), FIODTYPE, &type))
                        err(1, "%s", fname);
                /*
                 * Most tape drives don't support seeking,
                 * yet fseek() would succeed.
                 */
                if (type & D_TAPE) {
                        noseek();
                        return;
                }
        }
        if (fseeko(stdin, skip, SEEK_SET)) {
                noseek();
                return;
        }
        address += skip;
        skip = 0;
}

static void
noseek(void)
{
        int count;
        for (count = 0; count < skip; ++count)
                if (getchar() == EOF)
                        break;
        address += count;
        skip -= count;
}