geoip-legacy

A port of libGeoIP from C to pure Go. It supports IPv4 and IPv6 country databases.

Example usage

For extensive examples, see geoip_test.go, but here is a relatively simple example. GetCountryByAddr supports IP addresses and can use the net package in the standard library to resolve a domain to an IP and look up the IP in the database.

IPv4-only DB example:

db, err := geoiplegacy.OpenDB("/usr/share/GeoIP/GeoIP.dat", nil)
if err != nil {
	panic(err)
}
country, err = db.GetCountryByAddr("8.8.8.8")
if err != nil {
	panic(err)
}
fmt.Printf("Country code: %s\nCountry name: %s\n", country.Code, country.NameUTF8)

IPv6-only DB example:

db, err := geoiplegacy.OpenDB("/usr/share/GeoIP/GeoIPv6.dat", &GeoIPOptions{
	IsIPv6: true,
})
if err != nil {
	panic(err)
}
country, err = db.GetCountryByAddr("2801::1")
if err != nil {
	panic(err)
}
fmt.Printf("Country code: %s\nCountry name: %s\n", country.Code, country.NameUTF8)

Combined DB example usage

The above examples are only usable for looking up either IPv4 or IPv6 addresses. To be able to look up both, you can use a CombinedDB. Example usage:

db, err := geoiplegacy.OpenCombinedDB("/usr/share/GeoIP/GeoIP.dat", "/usr/share/GeoIP/GeoIPv6.dat")
if err != nil {
	panic(err)
}
country, err = db.GetCountryByAddr("8.8.8.8")
// ...
country, err = db.GetCountryByAddr("2801::1")
// ...
country, err = db.GetCountryByAddr("google.com")
// ...

A regular DB can also handle domains, but a domain may or may not resolve to an IPv6 address, so a CombinedDB is recommended.