1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
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
false 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]
```
|
