package main

import (
    "net"
)

func LocalIpAddrs() ([]net.IP, error) {
    var localAddrs = []net.IP{}
    addrs, err := net.InterfaceAddrs()
    if err != nil {
        return []net.IP{}, err
    }
    for _, addr := range addrs {
        if ipnet, ok := addr.(*net.IPNet); ok {
            localAddrs = append(localAddrs, ipnet.IP)
        }
    }
    return localAddrs, nil
}

func LocalIpAddrsAsStrings(include_loopbacks bool) ([]string, error) {
    var localAddrsStrings = []string{}
    var err error
    ipaddrs, err := LocalIpAddrs()
    if err != nil {
        return []string{}, err
    }
    for _, ipaddr := range ipaddrs {
        if include_loopbacks || !ipaddr.IsLoopback() {
            localAddrsStrings = append(localAddrsStrings, ipaddr.String())
        }
    }
    return localAddrsStrings, err
}

func IsLoopback(ip_str string) (bool, error) {
    ip := net.ParseIP(ip_str)
    if ip == nil {
        return false, MsgError("Wrong IP format %s", ip_str)
    }
    return ip.IsLoopback(), nil
}