FBB::Cidr(3bobcat)

CIDR matching
(libbobcat-dev_6.04.00)

2005-2023

NAME

FBB::Cidr - Compares IP4 addresses to CIDR specifications

SYNOPSIS

#include <bobcat/cidr>
Linking option: -lbobcat

DESCRIPTION

Objects of the class Cidr can be used for testing whether IP4 Internet addresses belong to address ranges defined by Classless Inter-Domain Routing (CIDR) address block specifications. CIDR blocks are specified as a.b.c.d/m where a.b.c.d are the four octets of a dotted decimal IP4 address specification (e.g., 129.125.14.80) and m is a mask-size (ranging from 0 to 32) defining the number of most significant bits to remain as-is. The CIDR specification 129.125.14.80/16 defines a class B network, with addresses ranging from 129.125.0.0 to 129.125.255.255.

The mask size does not have to be a multiple of 8. E.g., when specifying 129.125.14.80/5 only the most significant 5 bits of the first octed are fixed, resulting in an address range ranging from 128.0.0.0 to 135.255.255.255.

CIDR specifications passed to a Cidr object must be of the form a.b.c.d or a.b.c.d/m. If the mask is not specified a mask-size of 32 is used, effectively defining an address range of only one address. Mask values of 0 are ignored. Mask values of 0 are ignored by Cidr objects.

When specifying CIDRs on a stream, empty lines and comment lines (having a hash-character (#) as their first non-blank character) are ignored. Non-empty lines must start with a CIDR specification, and the Cidr object will ignore all information on a line trailing a CIDR specification.

NAMESPACE

FBB
All constructors, members, operators and manipulators, mentioned in this man-page, are defined in the namespace FBB.

INHERITS FROM

-

CONSTRUCTORS

Default, copy and move constructors and the copy and move assignment operators are available.

MEMBER FUNCTIONS

The return valuess of the accessors (i.e., the const members) are only defined following a successful match (see below, the match members).

STATIC MEMBERS

EXAMPLE


#include <fstream>
#include <iostream>

#include <bobcat/exception>
#ifdef BOBCAT
    #include <bobcat/cidr>
#else
    #include "cidr"
#endif

using namespace std;
using namespace FBB;

int main(int argc, char **argv)
{
    enum Spec
    {
        NONE,
        FILE,
        CIN
    };

    Spec spec = CIN;
    ifstream in;

    if (argc > 1)
    {
        Exception::open(in, argv[1]);       // file containing cidr-specs
        spec = FILE;
    }

    while (true)
    {
        string cidrSpec;
        if (spec == CIN)
        {
            cout << "Specify cidr (empty to quit): ";
            if (!getline(cin, cidrSpec) || cidrSpec.empty())
                break;
        }
        try
        {
            Cidr cidr;

            switch (spec)
            {
                case NONE:
                return 0;

                case FILE:
                    cidr.setCidr(in);
                    spec = NONE;
                break;

                case CIN:
                    cidr.setCidr(cidrSpec);
            }

            while (true)
            {
                cout << "Specify address to test (empty to " <<
                    (spec == CIN ? "respec. CIDR" : "quit") << "): ";
                string address;
                if (!getline(cin, address) || address.empty())
                    break;

                if (!cidr.match(address))
                {
                    cout << "Address " << address << " not in ";
                    if (spec == CIN)
                        cout << cidrSpec << '\n';
                    else
                        cout << "specifications in " << argv[1] << '\n';
                }
                else
                    cout << "Address " << address << " in " << cidr.cidr() <<
                                                                        "\n"
                        "Lowest address: " << cidr.first() << "\n"
                        "Highest address: " << cidr.last() << "\n"
                        "CIDR mask: " << cidr.mask() << "\n"
                        "Address: " << cidr.address() << '\n';
            }
        }
        catch (exception const &err)
        {
            cout << "Oops... " << err.what() << "\n"
                    "Try again...\n";
        }
    }
}

FILES

bobcat/cidr - defines the class interface

SEE ALSO

bobcat(7)

BUGS

Members of Cidr use static data. The current implementation of Cidr is therefore not thread-safe.

BOBCAT PROJECT FILES

BOBCAT

Bobcat is an acronym of `Brokken's Own Base Classes And Templates'.

COPYRIGHT

This is free software, distributed under the terms of the GNU General Public License (GPL).

AUTHOR

Frank B. Brokken (f.b.brokken@rug.nl).