inet_util.rs

#![feature(i128)]
#![feature(i128_type)]

use std::u128;
use std::net::{Ipv4Addr, Ipv6Addr};
use ipnetwork::IpNetwork;

// Convert 128-bit number to ipv6 address.
fn decimal_to_ipv6(n: u128) -> Ipv6Addr {
    Ipv6Addr::new(
        (n >> 112) as u16 & 0xffff,
        (n >> 96) as u16 & 0xffff,
        (n >> 80) as u16 & 0xffff,
        (n >> 64) as u16 & 0xffff,
        (n >> 48) as u16 & 0xffff,
        (n >> 32) as u16 & 0xffff,
        (n >> 16) as u16 & 0xffff,
        n as u16
    )
}

// Convert 32-bit number to ipv4 address.
fn decimal_to_ipv4(n: u32) -> Ipv4Addr {
    Ipv4Addr::new(
        (n >> 24) as u8 & 0xff,
        (n >> 16) as u8 & 0xff,
        (n >> 8) as u8 & 0xff,
        n as u8
    )
}

// Calculate the network mask that contains the lo to hi ipv6 range.
pub fn merge_ipv6_network(lo: u128, hi: u128) -> IpNetwork {
    IpNetwork::new(decimal_to_ipv6(lo).into(), (lo ^ hi).leading_zeros() as u8).unwrap()
}

// Calculate the network mask that contains the lo to hi ipv4 range.
pub fn merge_ipv4_network(lo: u32, hi: u32) -> IpNetwork {
    IpNetwork::new(decimal_to_ipv4(lo).into(), (lo ^ hi).leading_zeros() as u8).unwrap()
}


#[test]
fn test_decimal_to_ipv6() {
    let lo: u128 = 281470698520576;
    let hi: u128 = 281470698520831;
    assert_eq!(decimal_to_ipv6(lo), "::ffff:1.0.0.0".parse::<Ipv6Addr>().unwrap());
    assert_eq!(decimal_to_ipv6(hi), "::ffff:1.0.0.255".parse::<Ipv6Addr>().unwrap());
}

#[test]
fn test_merge_ipv6_network() {
    let lo: u128 = 281470698520576;
    let hi: u128 = 281470698520831;
    // "::ffff:1.0.0.0/120"
    assert_eq!(merge_ipv6_network(lo, hi), "::ffff:1.0.0.0/120".parse::<IpNetwork>().unwrap());
}