util.c

/*
 * Copyright (c) 2016, Bjorn Andersson <bjorn@kryo.se>
 * 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 copyright holder 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 <ctype.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <libxml/parser.h>
#include <libxml/tree.h>

#define MIN(x, y) ((x) < (y) ? (x) : (y))

static uint8_t to_hex(uint8_t ch) {
    ch &= 0xf;
    return ch <= 9 ? '0' + ch : 'a' + ch - 10;
}

void print_hex_dump(const char *prefix, const void *buf, size_t len) {
    const uint8_t *ptr = buf;
    size_t line_len;
    uint8_t ch;
    char line[16 * 3 + 16 + 1];
    int li;
    int i;
    int j;

    for (i = 0; i < len; i += 16) {
        line_len = MIN(16, len - i);
        li = 0;

        for (j = 0; j < line_len; j++) {
            ch = ptr[i + j];
            line[li++] = (char) to_hex(ch >> 4);
            line[li++] = (char) to_hex(ch);
            line[li++] = ' ';
        }

        for (; j < 16; j++) {
            line[li++] = ' ';
            line[li++] = ' ';
            line[li++] = ' ';
        }

        for (j = 0; j < line_len; j++) {
            ch = ptr[i + j];
            line[li++] = isprint(ch) ? ch : '.';
        }

        line[li] = '\0';

        printf("%s %04x: %s\n", prefix, i, line);
    }
}

unsigned attr_as_unsigned(xmlNode *node, const char *attr, int *errors) {
    xmlChar *value;

    value = xmlGetProp(node, (xmlChar *) attr);
    if (!value) {
        (*errors)++;
        return 0;
    }

    return (unsigned int) strtoul((char *) value, NULL, 0);
}

const char *attr_as_string(xmlNode *node, const char *attr, int *errors) {
    xmlChar *value;

    value = xmlGetProp(node, (xmlChar *) attr);
    if (!value) {
        (*errors)++;
        return NULL;
    }

    if (value[0] == '\0')
        return NULL;

    return strdup((char *) value);
}