Crate maxminddb 

A reader for the MaxMind DB file format, including the GeoIP2 and GeoLite2 databases published by MaxMind.

Usage

Open a database and look up an address:

use std::net::IpAddr;

use maxminddb::geoip2;

let reader = maxminddb::Reader::open_readfile("GeoIP2-City.mmdb")?;
let ip: IpAddr = "89.160.20.128".parse().unwrap();
let city: geoip2::City<'_> = reader.lookup(ip)?;
println!("{city:?}");

Reader::from_source accepts any buffer that implements AsRef<[u8]>, which is useful when the database is already in memory or memory-mapped by the caller.

To iterate over every network in the database, use Reader::within. The examples/ directory contains lookup, within, and write_database examples.

Resource limits

A MaxMind DB encodes values with pointers, and many pointers may share one target, so a small record can describe a very large or deeply nested structure when expanded. To keep hostile or corrupt databases from consuming unbounded time or memory, decoding is bounded by DecodeLimits:

• a maximum nesting depth of 512 (maps, arrays, and followed pointers),
• a maximum of 65_536 decoded values per operation, and
• a maximum of 2 MiB of string and byte payload per operation.

These are the values recommended by the MaxMind DB specification. When a limit is exceeded, decoding fails with MaxMindDBError::ResourceLimit instead of panicking or exhausting memory. The limits apply to metadata decoding at open as well as to record lookups.

Use Reader::from_source_with_options or Reader::open_readfile_with_options with a ReaderOptions value to configure the limits.

A database that is a valid IPv4-only file but is looked up with an IPv6 address or CIDR is rejected with MaxMindDBError::InvalidInputError; the address family must match the database.

Supported databases

Both IPv4 and IPv6 databases are supported, as are the 24-, 28-, and 32-bit search tree record sizes. The geoip2 module provides typed records for the common GeoIP2 and GeoLite2 database shapes. For other databases, deserialize into your own type or into Value.

Re-exports

pub use encoder::Value;

Modules

decoder

encoder

geoip2

writer

Macros

map

Build a Value::Map from key => value pairs.

Structs

DecodeLimits

Resource limits applied while decoding a single data entry or the metadata section.

Metadata

Reader

A reader for the MaxMind DB format. The lifetime of the decoded values is tied to the lifetime of the underlying buffer holding the contents of the database file.

ReaderOptions

Options controlling how a Reader opens and decodes a database.

Within

WithinItem

Enums

MaxMindDBError