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diff --git a/middleware/node_modules/ipaddr.js/README.md b/middleware/node_modules/ipaddr.js/README.md new file mode 100644 index 0000000..f57725b --- /dev/null +++ b/middleware/node_modules/ipaddr.js/README.md @@ -0,0 +1,233 @@ +# ipaddr.js — an IPv6 and IPv4 address manipulation library [](https://travis-ci.org/whitequark/ipaddr.js) + +ipaddr.js is a small (1.9K minified and gzipped) library for manipulating +IP addresses in JavaScript environments. It runs on both CommonJS runtimes +(e.g. [nodejs]) and in a web browser. + +ipaddr.js allows you to verify and parse string representation of an IP +address, match it against a CIDR range or range list, determine if it falls +into some reserved ranges (examples include loopback and private ranges), +and convert between IPv4 and IPv4-mapped IPv6 addresses. + +[nodejs]: http://nodejs.org + +## Installation + +`npm install ipaddr.js` + +or + +`bower install ipaddr.js` + +## API + +ipaddr.js defines one object in the global scope: `ipaddr`. In CommonJS, +it is exported from the module: + +```js +var ipaddr = require('ipaddr.js'); +``` + +The API consists of several global methods and two classes: ipaddr.IPv6 and ipaddr.IPv4. + +### Global methods + +There are three global methods defined: `ipaddr.isValid`, `ipaddr.parse` and +`ipaddr.process`. All of them receive a string as a single parameter. + +The `ipaddr.isValid` method returns `true` if the address is a valid IPv4 or +IPv6 address, and `false` otherwise. It does not throw any exceptions. + +The `ipaddr.parse` method returns an object representing the IP address, +or throws an `Error` if the passed string is not a valid representation of an +IP address. + +The `ipaddr.process` method works just like the `ipaddr.parse` one, but it +automatically converts IPv4-mapped IPv6 addresses to their IPv4 counterparts +before returning. It is useful when you have a Node.js instance listening +on an IPv6 socket, and the `net.ivp6.bindv6only` sysctl parameter (or its +equivalent on non-Linux OS) is set to 0. In this case, you can accept IPv4 +connections on your IPv6-only socket, but the remote address will be mangled. +Use `ipaddr.process` method to automatically demangle it. + +### Object representation + +Parsing methods return an object which descends from `ipaddr.IPv6` or +`ipaddr.IPv4`. These objects share some properties, but most of them differ. + +#### Shared properties + +One can determine the type of address by calling `addr.kind()`. It will return +either `"ipv6"` or `"ipv4"`. + +An address can be converted back to its string representation with `addr.toString()`. +Note that this method: + * does not return the original string used to create the object (in fact, there is + no way of getting that string) + * returns a compact representation (when it is applicable) + +A `match(range, bits)` method can be used to check if the address falls into a +certain CIDR range. +Note that an address can be (obviously) matched only against an address of the same type. + +For example: + +```js +var addr = ipaddr.parse("2001:db8:1234::1"); +var range = ipaddr.parse("2001:db8::"); + +addr.match(range, 32); // => true +``` + +Alternatively, `match` can also be called as `match([range, bits])`. In this way, +it can be used together with the `parseCIDR(string)` method, which parses an IP +address together with a CIDR range. + +For example: + +```js +var addr = ipaddr.parse("2001:db8:1234::1"); + +addr.match(ipaddr.parseCIDR("2001:db8::/32")); // => true +``` + +A `range()` method returns one of predefined names for several special ranges defined +by IP protocols. The exact names (and their respective CIDR ranges) can be looked up +in the source: [IPv6 ranges] and [IPv4 ranges]. Some common ones include `"unicast"` +(the default one) and `"reserved"`. + +You can match against your own range list by using +`ipaddr.subnetMatch(address, rangeList, defaultName)` method. It can work with a mix of IPv6 or IPv4 addresses, and accepts a name-to-subnet map as the range list. For example: + +```js +var rangeList = { + documentationOnly: [ ipaddr.parse('2001:db8::'), 32 ], + tunnelProviders: [ + [ ipaddr.parse('2001:470::'), 32 ], // he.net + [ ipaddr.parse('2001:5c0::'), 32 ] // freenet6 + ] +}; +ipaddr.subnetMatch(ipaddr.parse('2001:470:8:66::1'), rangeList, 'unknown'); // => "tunnelProviders" +``` + +The addresses can be converted to their byte representation with `toByteArray()`. +(Actually, JavaScript mostly does not know about byte buffers. They are emulated with +arrays of numbers, each in range of 0..255.) + +```js +var bytes = ipaddr.parse('2a00:1450:8007::68').toByteArray(); // ipv6.google.com +bytes // => [42, 0x00, 0x14, 0x50, 0x80, 0x07, 0x00, <zeroes...>, 0x00, 0x68 ] +``` + +The `ipaddr.IPv4` and `ipaddr.IPv6` objects have some methods defined, too. All of them +have the same interface for both protocols, and are similar to global methods. + +`ipaddr.IPvX.isValid(string)` can be used to check if the string is a valid address +for particular protocol, and `ipaddr.IPvX.parse(string)` is the error-throwing parser. + +`ipaddr.IPvX.isValid(string)` uses the same format for parsing as the POSIX `inet_ntoa` function, which accepts unusual formats like `0xc0.168.1.1` or `0x10000000`. The function `ipaddr.IPv4.isValidFourPartDecimal(string)` validates the IPv4 address and also ensures that it is written in four-part decimal format. + +[IPv6 ranges]: https://github.com/whitequark/ipaddr.js/blob/master/src/ipaddr.coffee#L186 +[IPv4 ranges]: https://github.com/whitequark/ipaddr.js/blob/master/src/ipaddr.coffee#L71 + +#### IPv6 properties + +Sometimes you will want to convert IPv6 not to a compact string representation (with +the `::` substitution); the `toNormalizedString()` method will return an address where +all zeroes are explicit. + +For example: + +```js +var addr = ipaddr.parse("2001:0db8::0001"); +addr.toString(); // => "2001:db8::1" +addr.toNormalizedString(); // => "2001:db8:0:0:0:0:0:1" +``` + +The `isIPv4MappedAddress()` method will return `true` if this address is an IPv4-mapped +one, and `toIPv4Address()` will return an IPv4 object address. + +To access the underlying binary representation of the address, use `addr.parts`. + +```js +var addr = ipaddr.parse("2001:db8:10::1234:DEAD"); +addr.parts // => [0x2001, 0xdb8, 0x10, 0, 0, 0, 0x1234, 0xdead] +``` + +A IPv6 zone index can be accessed via `addr.zoneId`: + +```js +var addr = ipaddr.parse("2001:db8::%eth0"); +addr.zoneId // => 'eth0' +``` + +#### IPv4 properties + +`toIPv4MappedAddress()` will return a corresponding IPv4-mapped IPv6 address. + +To access the underlying representation of the address, use `addr.octets`. + +```js +var addr = ipaddr.parse("192.168.1.1"); +addr.octets // => [192, 168, 1, 1] +``` + +`prefixLengthFromSubnetMask()` will return a CIDR prefix length for a valid IPv4 netmask or +null if the netmask is not valid. + +```js +ipaddr.IPv4.parse('255.255.255.240').prefixLengthFromSubnetMask() == 28 +ipaddr.IPv4.parse('255.192.164.0').prefixLengthFromSubnetMask() == null +``` + +`subnetMaskFromPrefixLength()` will return an IPv4 netmask for a valid CIDR prefix length. + +```js +ipaddr.IPv4.subnetMaskFromPrefixLength(24) == "255.255.255.0" +ipaddr.IPv4.subnetMaskFromPrefixLength(29) == "255.255.255.248" +``` + +`broadcastAddressFromCIDR()` will return the broadcast address for a given IPv4 interface and netmask in CIDR notation. +```js +ipaddr.IPv4.broadcastAddressFromCIDR("172.0.0.1/24") == "172.0.0.255" +``` +`networkAddressFromCIDR()` will return the network address for a given IPv4 interface and netmask in CIDR notation. +```js +ipaddr.IPv4.networkAddressFromCIDR("172.0.0.1/24") == "172.0.0.0" +``` + +#### Conversion + +IPv4 and IPv6 can be converted bidirectionally to and from network byte order (MSB) byte arrays. + +The `fromByteArray()` method will take an array and create an appropriate IPv4 or IPv6 object +if the input satisfies the requirements. For IPv4 it has to be an array of four 8-bit values, +while for IPv6 it has to be an array of sixteen 8-bit values. + +For example: +```js +var addr = ipaddr.fromByteArray([0x7f, 0, 0, 1]); +addr.toString(); // => "127.0.0.1" +``` + +or + +```js +var addr = ipaddr.fromByteArray([0x20, 1, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]) +addr.toString(); // => "2001:db8::1" +``` + +Both objects also offer a `toByteArray()` method, which returns an array in network byte order (MSB). + +For example: +```js +var addr = ipaddr.parse("127.0.0.1"); +addr.toByteArray(); // => [0x7f, 0, 0, 1] +``` + +or + +```js +var addr = ipaddr.parse("2001:db8::1"); +addr.toByteArray(); // => [0x20, 1, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1] +``` |