RIOT/sys/net/ccn_lite/ccnl-pdu.c

/*
 * @f ccnl-pdu.c
 * @b CCN lite - create and manipulate CCN protocol data units
 *
 * Copyright (C) 2011-13, Christian Tschudin, University of Basel
 * Copyright (C) 2013, Christian Mehlis, Freie Universität Berlin
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * File history:
 * 2011-03-13 created (cft): orig name ccnl-parse-ccnb.c
 * 2013-04-04 modified (ms): #if defined(CCNL_SIMULATION) || defined(CCNL_OMNET)
 */

#include <string.h>

#include "ccnl-core.h"
#include "ccnx.h"

int dehead(unsigned char **buf, int *len, int *num, int *typ)
{
    int i;
    int val = 0;

    if (*len > 0 && **buf == 0) { // end
        *num = *typ = 0;
        *buf += 1;
        *len -= 1;
        return 0;
    }

    for (i = 0; (unsigned int) i < sizeof(i) && i < *len; i++) {
        unsigned char c = (*buf)[i];

        if (c & 0x80) {
            *num = (val << 4) | ((c >> 3) & 0xf);
            *typ = c & 0x7;
            *buf += i + 1;
            *len -= i + 1;
            return 0;
        }

        val = (val << 7) | c;
    }

    return -1;
}

int mkHeader(unsigned char *buf, unsigned int num, unsigned int tt)
{
    unsigned char tmp[100];
    int len = 0, i;

    *tmp = 0x80 | ((num & 0x0f) << 3) | tt;
    len = 1;
    num = num >> 4;

    while (num > 0) {
        tmp[len++] = num & 0x7f;
        num = num >> 7;
    }

    for (i = len - 1; i >= 0; i--) {
        *buf++ = tmp[i];
    }

    return len;
}

static int addBlob(unsigned char *out, char *cp, int cnt)
{
    int len;

    len = mkHeader(out, cnt, CCN_TT_BLOB);
    memcpy(out + len, cp, cnt);
    len += cnt;

    return len;
}

int mkBlob(unsigned char *out, unsigned int num, unsigned int tt, char *cp,
           int cnt)
{
    int len;

    len = mkHeader(out, num, tt);
    len += addBlob(out + len, cp, cnt);
    out[len++] = 0;

    return len;
}

int mkStrBlob(unsigned char *out, unsigned int num, unsigned int tt, char *str)
{
    return mkBlob(out, num, tt, str, strlen(str));
}

int mkBinaryInt(unsigned char *out, unsigned int num, unsigned int tt,
                unsigned int val, int bytes)
{
    int len = mkHeader(out, num, tt);

    if (!bytes) {
        for (bytes = sizeof(val) - 1; bytes > 0; bytes--)
            if (val >> (8 * bytes)) {
                break;
            }

        bytes++;
    }

    len += mkHeader(out + len, bytes, CCN_TT_BLOB);

    while (bytes > 0) { // big endian
        bytes--;
        out[len++] = 0x0ff & (val >> (8 * bytes));
    }

    out[len++] = 0; // end-of-entry
    return len;
}

int unmkBinaryInt(unsigned char **data, int *datalen, unsigned int *result,
                  unsigned char *width)
{
    unsigned char *cp = *data;
    int len = *datalen, typ, num;
    unsigned int val = 0;

    if (dehead(&cp, &len, &num, &typ) != 0 || typ != CCN_TT_BLOB) {
        return -1;
    }

    if (width) {
        if (*width < num) {
            num = *width;
        }
        else {
            *width = num;
        }
    }

    // big endian (network order):
    while (num-- > 0 && len > 0) {
        val = (val << 8) | *cp++;
        len--;
    }

    *result = val;

    if (len < 1 || *cp != '\0') { // no end-of-entry
        return -1;
    }

    *data = cp + 1;
    *datalen = len - 1;
    return 0;
}

// ----------------------------------------------------------------------
// (ms): Brought here the following two. I noticed also that some
// of them are replicated elsewhere in the util/ dir. Should we put them
// in one place only ?

int mkInterest(char **namecomp, unsigned int *nonce, unsigned char *out)
{
    int len = mkHeader(out, CCN_DTAG_INTEREST, CCN_TT_DTAG); // interest
    len += mkHeader(out + len, CCN_DTAG_NAME, CCN_TT_DTAG);  // name

    while (*namecomp) {
        len += mkHeader(out + len, CCN_DTAG_COMPONENT, CCN_TT_DTAG);  // comp
        int k = strlen(*namecomp);
        len += mkHeader(out + len, k, CCN_TT_BLOB);
        memcpy(out + len, *namecomp++, k);
        len += k;
        out[len++] = 0; // end-of-component
    }

    out[len++] = 0; // end-of-name

    if (nonce) {
        len += mkHeader(out + len, CCN_DTAG_NONCE, CCN_TT_DTAG);
        len += mkHeader(out + len, sizeof(unsigned int), CCN_TT_BLOB);
        memcpy(out + len, (void *) nonce, sizeof(unsigned int));
        len += sizeof(unsigned int);
    }

    out[len++] = 0; // end-of-interest

    return len;
}

int
mkContent(char **namecomp, char *data, int datalen, unsigned char *out)
{
    int len = mkHeader(out, CCN_DTAG_CONTENTOBJ, CCN_TT_DTAG); // content
    len += mkHeader(out + len, CCN_DTAG_NAME, CCN_TT_DTAG);    // name

    while (*namecomp) {
        len += mkHeader(out + len, CCN_DTAG_COMPONENT, CCN_TT_DTAG); // comp
        int k = strlen(*namecomp);
        len += mkHeader(out + len, k, CCN_TT_BLOB);
        memcpy(out + len, *namecomp++, k);
        len += k;
        out[len++] = 0;// end-of-component
    }

    out[len++] = 0; // end-of-name

    len += mkHeader(out + len, CCN_DTAG_CONTENT, CCN_TT_DTAG); // content obj
    len += mkHeader(out + len, datalen, CCN_TT_BLOB);
    memcpy(out + len, data, datalen);
    len += datalen;
    out[len++] = 0;// end-of-content obj

    out[len++] = 0;// end-of-content

    return len;
}

// eof