MACAddress.cc

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/*
 * Copyright (C) 2003 Andras Varga; CTIE, Monash University, Australia
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
*/

#include <ctype.h>
#include "MACAddress.h"
#include "InterfaceToken.h"


unsigned int MACAddress::autoAddressCtr;

//
// Converts hex string into a byte array 'destbuf'. Destbuf is 'size'
// chars long -- if hext string is shorter, destbuf is filled with zeros;
// if destbuf is longer, it is truncated. Non-hex characters are
// discarded before conversion. Returns number of bytes converted from hex.
//
static int hextobin(const char *hexstr, unsigned char *destbuf, int size)
{
    int k=0;
    const char *s = hexstr;
    for (int pos=0; pos<size; pos++)
    {
        if (!s || !*s)
        {
            destbuf[pos] = 0;
        }
        else
        {
            while (*s && !isxdigit(*s)) s++;
            if (!*s) {destbuf[pos]=0; continue;}
            unsigned char d = isdigit(*s) ? (*s-'0') : islower(*s) ? (*s-'a'+10) : (*s-'A'+10);
            d = d<<4;
            s++;

            while (*s && !isxdigit(*s)) s++;
            if (!*s) {destbuf[pos]=0; continue;}
            d += isdigit(*s) ? (*s-'0') : islower(*s) ? (*s-'a'+10) : (*s-'A'+10);
            s++;

            destbuf[pos] = d;
            k++;
        }
    }
    return k;
}

const MACAddress MACAddress::UNSPECIFIED_ADDRESS;
const MACAddress MACAddress::BROADCAST_ADDRESS("ff:ff:ff:ff:ff:ff");

MACAddress::MACAddress()
{
    address[0]=address[1]=address[2]=address[3]=address[4]=address[5]=0;
}

MACAddress::MACAddress(const char *hexstr)
{
    setAddress(hexstr);
}

MACAddress& MACAddress::operator=(const MACAddress& other)
{
    memcpy(address, other.address, MAC_ADDRESS_BYTES);
    return *this;
}

unsigned int MACAddress::getAddressSize() const
{
    return 6;
}

unsigned char MACAddress::getAddressByte(unsigned int k) const
{
    if (k>=6) throw cRuntimeError("Array of size 6 indexed with %d", k);
    return address[k];
}

void MACAddress::setAddressByte(unsigned int k, unsigned char addrbyte)
{
    if (k>=6) throw cRuntimeError("Array of size 6 indexed with %d", k);
    address[k] = addrbyte;
}

bool MACAddress::tryParse(const char *hexstr)
{
    if (!hexstr)
        return false;

    // check syntax
    int numHexDigits = 0;
    for (const char *s = hexstr; *s; s++) {
        if (isxdigit(*s))
            numHexDigits++;
        else if (*s!=' ' && *s!=':' && *s!='-')
            return false; // wrong syntax
    }
    if (numHexDigits != 2*MAC_ADDRESS_BYTES)
        return false;

    // convert
    hextobin(hexstr, address, MAC_ADDRESS_BYTES);
    return true;
}

void MACAddress::setAddress(const char *hexstr)
{
    if (!tryParse(hexstr))
        throw cRuntimeError("MACAddress: wrong address syntax '%s': 12 hex digits expected, with optional embedded spaces, hyphens or colons", hexstr);
}

void MACAddress::setAddressBytes(unsigned char *addrbytes)
{
    memcpy(address, addrbytes, MAC_ADDRESS_BYTES);
}

void MACAddress::setBroadcast()
{
    address[0]=address[1]=address[2]=address[3]=address[4]=address[5]=0xff;
}

bool MACAddress::isBroadcast() const
{
    return (address[0]&address[1]&address[2]&address[3]&address[4]&address[5])==0xff;
}

bool MACAddress::isUnspecified() const
{
    return !(address[0] || address[1] || address[2] || address[3] || address[4] || address[5]);
}

std::string MACAddress::str() const
{
    char buf[20];
    char *s = buf;
    for (int i=0; i<MAC_ADDRESS_BYTES; i++, s+=3)
        sprintf(s,"%2.2X-",address[i]);
    *(s-1)='\0';
    return std::string(buf);
}

bool MACAddress::equals(const MACAddress& other) const
{
    return memcmp(address, other.address, MAC_ADDRESS_BYTES)==0;
}

int MACAddress::compareTo(const MACAddress& other) const
{
    return memcmp(address, other.address, MAC_ADDRESS_BYTES);
}

InterfaceToken MACAddress::formInterfaceIdentifier() const
{
    const unsigned char *b = address;
    uint32 high = (b[0]<<24) | (b[1]<<16) | (b[2]<<8) | 0xff;
    uint32 low =  (0xfe<<24) | (b[3]<<16) | (b[4]<<8) | b[5];
    return InterfaceToken(low, high, 64);
}

MACAddress MACAddress::generateAutoAddress()
{
    ++autoAddressCtr;

    unsigned char addrbytes[6];
    addrbytes[0] = 0x0A;
    addrbytes[1] = 0xAA;
    addrbytes[2] = (autoAddressCtr>>24)&0xff;
    addrbytes[3] = (autoAddressCtr>>16)&0xff;
    addrbytes[4] = (autoAddressCtr>>8)&0xff;
    addrbytes[5] = (autoAddressCtr)&0xff;

    MACAddress addr;
    addr.setAddressBytes(addrbytes);
    return addr;
}