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proxy-addr

Determine address of proxied request

# Install

This is a Node.js module available through the npm registry. Installation is done using the `npm install` command:

$ npm install proxy-addr

# API

var proxyaddr = require('proxy-addr')

## proxyaddr(req, trust)

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` arugment 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.

## proxyaddr.all(req, [trust])

Return all the addresses of the request, 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')

## proxyaddr.compile(val)

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)`.

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

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

# Testing

$ npm test

# Benchmarks

$ npm run-script bench

# License

[MIT](LICENSE)