GeoIP Legacy C Library

Important Note

This library is for the GeoIP Legacy format (dat). To read the MaxMind DB format (mmdb) used by GeoIP2, please see libmaxminddb.

Description

The GeoIP Legacy C library enables the user to find geographical and network information of an IP address. To use this library, you may download our free GeoLite Legacy Country or City databases. These are updated at the beginning of every month. The latest versions are available at:

http://dev.maxmind.com/geoip/legacy/geolite

We also offer commercial GeoIP Legacy databases with greater accuracy and additional network information. For more details, see:

https://www.maxmind.com/en/geolocation_landing

If you use GeoIP Legacy to block access from high risk countries, you may wish to use our proxy detection service to block access from known proxy servers to reduce fraud and abuse. For more details, see:

https://www.maxmind.com/en/proxy

IP Geolocation Usage

IP geolocation is inherently imprecise. Locations are often near the center of the population. Any location provided by a GeoIP database should not be used to identify a particular address or household.

Installation

On Ubuntu Using PPA

MaxMind provides a PPA for recent version of Ubuntu. To add the PPA to your APT sources, run:

$ sudo add-apt-repository ppa:maxmind/ppa

Then install the packages by running:

$ sudo aptitude update
$ sudo aptitude install libgeoip1 libgeoip-dev geoip-bin

From Source on Unix/Linux

To install, run:

./configure
make
make check
make install

If you are using a GitHub checkout, please run the bootstrap script first to set up the build environment.

The GeoIP Legacy C library relies on GNU make, not on BSD make

From Source with Visual Studio (nmake)

To make a static GeoIP.lib, edit the top level Makefile.vc to reflect where the GeoIP.dat database file should be placed, as well as the locations of the lib, include, and bin directories for installation.

To build and install, issue the following commands from a developer console:

nmake /f Makefile.vc
nmake /f Makefile.vc test
nmake /f Makefile.vc install

From Source with MinGW

./configure
make
cp data/GeoIP.dat test/
make check

Note that GeoIP.dat file should be placed in the same place as GeoIP-enabled executable modules.

Memory Caching and Other Options

There are five options available:

GEOIP_STANDARD - Read database from file system. This uses the least memory.
GEOIP_MEMORY_CACHE - Load database into memory. Provides faster performance but uses more memory.
GEOIP_CHECK_CACHE - Check for updated database. If database has been updated, reload file handle and/or memory cache.
GEOIP_INDEX_CACHE - Cache only the the most frequently accessed index portion of the database, resulting in faster lookups than GEOIP_STANDARD, but less memory usage than GEOIP_MEMORY_CACHE. This is useful for larger databases such as GeoIP Legacy Organization and GeoIP Legacy City. Note: for GeoIP Legacy Country, Region and Netspeed databases, GEOIP_INDEX_CACHE is equivalent to GEOIP_MEMORY_CACHE.
GEOIP_MMAP_CACHE - Load database into mmap shared memory. MMAP is not available for 32bit Windows.
GEOIP_SILENCE - Disables diagnostic messages to stderr in the library; error conditions are detectable via the return values.

These options can be combined using bit operators. For example you can use both GEOIP_MEMORY_CACHE and GEOIP_CHECK_CACHE by calling:

GeoIP_open("/path/to/GeoIP.dat", GEOIP_MEMORY_CACHE | GEOIP_CHECK_CACHE);

By default, the city name is returned in iso-8859-1 charset. To obtain the city name in utf8 instead, run:

GeoIP_set_charset(gi, GEOIP_CHARSET_UTF8);

To get the netmask of the netblock of the last lookup, use GeoIP_last_netblock(gi).

Examples

See the following files for examples of how to use the API:

test/
     test-geoip.c
     test-geoip-region.c
     test-geoip-city.c
     test-geoip-isp.c
     test-geoip-org.c
     test-geoip-netspeed.c

The test-geoip.c program works with both the GeoLite Legacy and GeoIP Legacy Country databases. The test-geoip-city.c program works with both the GeoLite Legacy and GeoIP Legacy City databases. The other example programs require the paid databases available (https://www.maxmind.com/en/geolocation_landing).

Troubleshooting

Autotool Issues

In case of trouble building from source with libtool or autotools, update the generated configuration files by running:

./bootstrap

autoreconf -vfi

aclocal && autoconf && automake --add-missing

Threads

Lookups are thread safe, but libGeoIP does not guard the functions. Do not drop or change the GeoIP database if other threads might be using the database.

The recommended pattern is:

open database with GEOIP_MEMORY_CACHE
create_threads(your_thread_entry_function)
use the database
join_threads
close database

Thread Safety on Windows

The Windows build is not thread-safe in STANDARD mode because the pread is not thread-safe.

Other Build Issues

If you run into trouble building your application with GeoIP Legacy support, try adding -fms-extensions to your CFLAGS. If you use Solaris and the default C compiler, use -features=extensions instead. These options enable unnamed union support to fix problems like: improper member use: dma_code or 'GeoIPRecord' has no member named 'dma_code'.

Note that it is recommended that you use GNU make. Also, if you are using OpenBSD, this library requires OpenBSD 3.1 or greater.

If you get a "cannot load shared object file: No such file or directory" error, add the directory libGeoIP.so was installed to the /etc/ld.so.conf file and run ldconfig.

Solaris

On Solaris, if you get a ld: fatal: relocations remain against allocatable but non-writable sections, try runnign:

make clean
./configure --disable-shared
make

If you get a ar : command not found error, make sure that ar is in your path. On Solaris, ar is typically found in /usr/ccs/bin

AIX

If you get a passing argument 3 of 'gethostbyname_r' from incompatible pointer type error on AIX, untar a fresh copy of thie library and delete the following two lines from ./configure:

#define HAVE_GETHOSTBYNAME_R 1

#define GETHOSTBYNAME_R_RETURNS_INT 1

then save the configure script and build it as usual:

./configure
make
sudo make install

Bug Tracker

Please report all issues with this code using the GitHub issue tracker.

If you are having an issue with a MaxMind database that is not specific to this API, please contact MaxMind support.

Contributing

To contribute, please submit a pull request on GitHub.

fser / geoip-api-c