Determine the address of a proxied request.

Forked from https://github.com/jshttp/proxy-addr to address jshttp/forwarded#9.

$ npm i @fastify/proxy-addr

const proxyaddr = require('@fastify/proxy-addr')

Return the address of the request, using the given trust parameter.

The trust argument is a function that returns true if you trust the address, false if you don't. The closest untrusted address is returned.

proxyaddr(req, function (addr) { return addr === '127.0.0.1' })
proxyaddr(req, function (addr, i) { return i < 1 })

The trust argument may also be a single IP address string or an array of trusted addresses, as plain IP addresses, CIDR-formatted strings, or IP/netmask strings.

proxyaddr(req, '127.0.0.1')
proxyaddr(req, ['127.0.0.0/8', '10.0.0.0/8'])
proxyaddr(req, ['127.0.0.0/255.0.0.0', '192.168.0.0/255.255.0.0'])

This module also supports IPv6. Your IPv6 addresses will be normalized automatically (i.e. fe80::00ed:1 equals fe80:0:0:0:0:0:ed:1).

proxyaddr(req, '::1')
proxyaddr(req, ['::1/128', 'fe80::/10'])

This module will automatically work with IPv4-mapped IPv6 addresses as well to support node.js in IPv6-only mode. This means that you do not have to specify both ::ffff:a00:1 and 10.0.0.1.

As a convenience, this module also takes certain pre-defined names in addition to IP addresses, which expand into IP addresses:

proxyaddr(req, 'loopback')
proxyaddr(req, ['loopback', 'fc00:ac:1ab5:fff::1/64'])

• loopback: IPv4 and IPv6 loopback addresses (like ::1 and 127.0.0.1).
• linklocal: IPv4 and IPv6 link-local addresses (like fe80::1:1:1:1 and 169.254.0.1).
• uniquelocal: IPv4 private addresses and IPv6 unique-local addresses (like fc00:ac:1ab5:fff::1 and 192.168.0.1).

When trust is specified as a function, it will be called for each address to determine if it is a trusted address. The function is given two arguments: addr and i, where addr is a string of the address to check and i is a number that represents the distance from the socket address.

Return all the request addresses, optionally stopping at the first untrusted. This array is ordered from closest to furthest (i.e. arr[0] === req.connection.remoteAddress).

proxyaddr.all(req)

The optional trust argument takes the same arguments as trust does in proxyaddr(req, trust).

proxyaddr.all(req, 'loopback')

Compiles argument val into a trust function. This function takes the same arguments as trust does in proxyaddr(req, trust) and returns a function suitable for proxyaddr(req, trust).

const trust = proxyaddr.compile('loopback')
const addr = proxyaddr(req, trust)

This function is meant to be optimized for use against every request. It is recommended that a trust function be compiled up-front for the trusted configuration and passed to proxyaddr(req, trust) for each request.

$ npm test

$ npm run bench

Licensed under MIT.