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.
Default, copy and move constructors and the copy and move assignment operators are available.
The return valuess of the accessors (i.e., the const members) are only defined following a successful match (see below, the match members).
This is address 1.2.3.4 and this is 5.6.7.8and the CIDR specifications
5.1.1.1/8 1.2.1.1/16were provided to the Cidr object, then the object will report a match for 5.6.7.8.
As soon as a match is found match returns true. If none of the addresses found in the lines of in matches any of the object's CIDR specifications, false is returned.
If none of the addresses found in line matches any of the object's CIDR specifications, false is returned.
#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"; } } }