system/rndc/gencheck.c

	gencheck.c revision 0c27b3fe77ac1d5094ba3521e8142d9e7973133f
/*
 * Copyright (C) 2014-2016  Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

#include <config.h>

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#include <isc/print.h>

#define USAGE "usage: gencheck <filename>\n"

static int
check(const char *buf, ssize_t count, size_t *start) {
    const char chars[] = "abcdefghijklmnopqrstuvwxyz0123456789";
    ssize_t i;

    for (i = 0;
         i < count;
         i++, *start = (*start + 1) % (sizeof(chars) - 1))
    {
        /* Just ignore the trailing newline */
        if (buf[i] == '\n')
            continue;
        if (buf[i] != chars[*start])
            return 0;
    }

    return 1;
}

int
main(int argc, char **argv)
{
    int ret;
    int fd;
    ssize_t count;
    char buf[1024];
    size_t start;
    size_t length;

    ret = EXIT_FAILURE;
    fd = -1;
    length = 0;

    if (argc != 2) {
        fputs(USAGE, stderr);
        goto out;
    }

    fd = open(argv[1], O_RDONLY);
    if (fd == -1)
        goto out;

    start = 0;
    while ((count = read(fd, buf, sizeof(buf))) != 0) {
        if (count < 0)
            goto out;

        if (!check(buf, count, &start))
            goto out;

        length += count;
    }

    ret = EXIT_SUCCESS;

 out:
    printf("%lu\n", (unsigned long)length);

    if (fd != -1)
        close(fd);

    return (ret);
}