/*      $NetBSD: dumptar.c,v 1.3 2016/05/30 17:34:35 dholland Exp $     */

/*-
 * Copyright (c) 2004 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <err.h>
#include <assert.h>
#include <sys/stat.h>
#include <sys/mman.h>

#include "tar.h"

#define ussum(a) 1

/*
 * Ensure null termination.
 */
static char *
buf(const char *p, size_t s)
{
        static char buf[1024];

        assert(s < sizeof(buf));
        memcpy(buf, p, s);
        buf[s] = '\0';
        return buf;
}

static int
intarg(const char *p, size_t s)
{
        char *ep, *b = buf(p, s);
        int r = (int)strtol(b, &ep, 8);
        return r;
}

static int
usdump(void *p)
{
        HD_USTAR *t = p;
        int size = intarg(t->size, sizeof(t->size));
        size = ((size + 511) / 512) * 512 + 512;

        (void)fprintf(stdout, "*****\n");
#define PR(a) \
        (void)fprintf(stdout, #a "=%s\n", buf(t->a, sizeof(t->a)));
#define IPR(a) \
        (void)fprintf(stdout, #a "=%d\n", intarg(t->a, sizeof(t->a)));
#define OPR(a) \
        (void)fprintf(stdout, #a "=%o\n", intarg(t->a, sizeof(t->a)));
        PR(name);
        OPR(mode);
        IPR(uid);
        IPR(gid);
        IPR(size);
        OPR(mtime);
        OPR(chksum);
        (void)fprintf(stdout, "typeflag=%c\n", t->typeflag);
        PR(linkname);
        PR(magic);
        PR(version);
        PR(uname);
        PR(gname);
        OPR(devmajor);
        OPR(devminor);
        PR(prefix);
        return size;
}

int
main(int argc, char *argv[])
{
        int fd;
        struct stat st;
        char *p, *ep;

        if (argc != 2) {
                (void)fprintf(stderr, "Usage: %s <filename>\n", getprogname());
                return 1;
        }

        if ((fd = open(argv[1], O_RDONLY)) == -1)
                err(1, "Cannot open `%s'", argv[1]);

        if (fstat(fd, &st) == -1)
                err(1, "Cannot fstat `%s'", argv[1]);

        if ((p = mmap(NULL, (size_t)st.st_size, PROT_READ,
            MAP_FILE|MAP_PRIVATE, fd, (off_t)0)) == MAP_FAILED)
                err(1, "Cannot mmap `%s'", argv[1]);
        (void)close(fd);

        ep = (char *)p + (size_t)st.st_size;

        for (; p < ep + sizeof(HD_USTAR);) {
                if (ussum(p))
                        p += usdump(p);
        }
        return 0;
}