libaddr is an easy to use C++ library that parses IP addresses to objects.
This includes parsing IPv4 and IPv6 addresses, with a port or a CIDR mask.
The IPv4 support is limited to the 4 number dot notation (A.B.C.D).
IPv6 requires square brackets as we otherwise view the colon (:) as the port separator. So something like [::1]:123 will work. Just ::1 will be an error.
We support basic port notation by separating the address and port with a colon.
You may define a port range by separating two decimal numbers by a dash (-). For example 1-1023 would define all reserved ports.
Multiports is also available. You can write multiple ports separated by commas. This is useful if you want to handle a certain number of specific ports that are not clearly defined in a range. For example 1.2.3.4:80,443 references IPv4 address 1.2.3.4 and ports 80 and 443.
Masks are written after a slash (/).
A mask can be one decimal number, in which case it represents the number of bits from left to right that are set to 1.
The mask can also be an address. In case of an address, it has to use the same format as the first part (IPv4/IPv4 or IPv6/IPv6). Such a mask can be absolutely anything. (i.e. 85.85.85.85 would clear all even bits of an IPv4 address).
More or less from the time IPv6 was designed, the use of an address as
a mask has been deprecated. The library still supports such, however, by
default that feature is now turned off. Make sure to set the
addr::allow_t::ALLOW_ADDRESS_MASK parameter to true before parsing an
address if you want to allow such a feature (not recommanded).
It is possible to write an IPv4 address using the IPv6 syntax:
::ffff:192.168.1.1
Even though you write this IP address using the IPv6 syntax, the is_ipv4()
function will return true, which is expected. This can cause problems if
you really needed an IPv6 address, though. The library does not really have
the means, at the moment, to tell you whether it parsed an IPv4 or an IPv6
address.
Submit bug reports and patches on github.
This file is part of the snapcpp project.