Name

loc_database_lookup, loc_database_lookup_from_string - Lookup a network from the database

Synopsis

#include <libloc/database.h>

int loc_database_lookup(struct loc_database* db,
        const struct in6_addr* address, struct loc_network** network);

int loc_database_lookup_from_string(struct loc_database* db,
        const char* string, struct loc_network** network);

Description

The lookup functions find the network that an IP address belongs to. If the address is in more than one network, because a part of a network belongs to someone else, the smallest of them is being returned, which is the one that knows most about the address.

loc_database_lookup takes the IP address as struct in6_addr format which can either be a regular IPv6 address or a mapped IPv4 address.

loc_database_lookup_from_string takes the IP address as string and will parse it automatically.

The network tells which country the address is in, which Autonomous System announces it, and whether it is special in any way (see loc_network_get_asn(3)). The caller owns a reference to it and has to release it with loc_network_unref() (see loc_network_new(3)).

Looking up an address does not allocate any memory, except for the network that is being returned, and when the database checks whether its file has been replaced (see loc_database_reload(3)). It is safe to do from as many threads at the same time as needed.

Return Value

On success, zero is returned. This includes that there is no network for the address in the database, in which case network is set to NULL. On error, a negative error number (see errno(3)) is returned, for example -EINVAL if string is not an IP address. errno itself is not being set.

Example

struct loc_network* network = NULL;

int r = loc_database_lookup_from_string(db, "81.3.27.38", &network);
if (r == 0 && network) {
        printf("%s is in %s and announced by AS%u\n", loc_network_str(network),
                loc_network_get_country_code(network), loc_network_get_asn(network));

        loc_network_unref(network);
}

See Also

libloc(3), loc_network_new(3), loc_network_get_asn(3)

Authors

Michael Tremer