1 | // Copyright 2013 Selenium committers |
2 | // Copyright 2013 Software Freedom Conservancy |
3 | // |
4 | // Licensed under the Apache License, Version 2.0 (the "License"); |
5 | // you may not use this file except in compliance with the License. |
6 | // You may obtain a copy of the License at |
7 | // |
8 | // http://www.apache.org/licenses/LICENSE-2.0 |
9 | // |
10 | // Unless required by applicable law or agreed to in writing, software |
11 | // distributed under the License is distributed on an "AS IS" BASIS, |
12 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
13 | // See the License for the specific language governing permissions and |
14 | // limitations under the License. |
15 | |
16 | 'use strict'; |
17 | |
18 | var exec = require('child_process').exec, |
19 | fs = require('fs'), |
20 | net = require('net'); |
21 | |
22 | var promise = require('../index').promise; |
23 | |
24 | |
25 | /** |
26 | * The IANA suggested ephemeral port range. |
27 | * @type {{min: number, max: number}} |
28 | * @const |
29 | * @see http://en.wikipedia.org/wiki/Ephemeral_ports |
30 | */ |
31 | var DEFAULT_IANA_RANGE = {min: 49152, max: 65535}; |
32 | |
33 | |
34 | /** |
35 | * The epheremal port range for the current system. Lazily computed on first |
36 | * access. |
37 | * @type {webdriver.promise.Promise.<{min: number, max: number}>} |
38 | */ |
39 | var systemRange = null; |
40 | |
41 | |
42 | /** |
43 | * Computes the ephemeral port range for the current system. This is based on |
44 | * http://stackoverflow.com/a/924337. |
45 | * @return {webdriver.promise.Promise.<{min: number, max: number}>} A promise |
46 | * that will resolve to the ephemeral port range of the current system. |
47 | */ |
48 | function findSystemPortRange() { |
49 | if (systemRange) { |
50 | return systemRange; |
51 | } |
52 | var range = process.platform === 'win32' ? |
53 | findWindowsPortRange() : findUnixPortRange(); |
54 | return systemRange = range.thenCatch(function() { |
55 | return DEFAULT_IANA_RANGE; |
56 | }); |
57 | } |
58 | |
59 | |
60 | /** |
61 | * Executes a command and returns its output if it succeeds. |
62 | * @param {string} cmd The command to execute. |
63 | * @return {!webdriver.promise.Promise.<string>} A promise that will resolve |
64 | * with the command's stdout data. |
65 | */ |
66 | function execute(cmd) { |
67 | var result = promise.defer(); |
68 | exec(cmd, function(err, stdout) { |
69 | if (err) { |
70 | result.reject(err); |
71 | } else { |
72 | result.fulfill(stdout); |
73 | } |
74 | }); |
75 | return result.promise; |
76 | } |
77 | |
78 | |
79 | /** |
80 | * Computes the ephemeral port range for a Unix-like system. |
81 | * @return {!webdriver.promise.Promise.<{min: number, max: number}>} A promise |
82 | * that will resolve with the ephemeral port range on the current system. |
83 | */ |
84 | function findUnixPortRange() { |
85 | var cmd; |
86 | if (process.platform === 'sunos') { |
87 | cmd = |
88 | '/usr/sbin/ndd /dev/tcp tcp_smallest_anon_port tcp_largest_anon_port'; |
89 | } else if (fs.existsSync('/proc/sys/net/ipv4/ip_local_port_range')) { |
90 | // Linux |
91 | cmd = 'cat /proc/sys/net/ipv4/ip_local_port_range'; |
92 | } else { |
93 | cmd = 'sysctl net.inet.ip.portrange.first net.inet.ip.portrange.last' + |
94 | ' | sed -e "s/.*:\\s*//"'; |
95 | } |
96 | |
97 | return execute(cmd).then(function(stdout) { |
98 | if (!stdout || !stdout.length) return DEFAULT_IANA_RANGE; |
99 | var range = stdout.trim().split(/\s+/).map(Number); |
100 | if (range.some(isNaN)) return DEFAULT_IANA_RANGE; |
101 | return {min: range[0], max: range[1]}; |
102 | }); |
103 | } |
104 | |
105 | |
106 | /** |
107 | * Computes the ephemeral port range for a Windows system. |
108 | * @return {!webdriver.promise.Promise.<{min: number, max: number}>} A promise |
109 | * that will resolve with the ephemeral port range on the current system. |
110 | */ |
111 | function findWindowsPortRange() { |
112 | var deferredRange = promise.defer(); |
113 | // First, check if we're running on XP. If this initial command fails, |
114 | // we just fallback on the default IANA range. |
115 | return execute('cmd.exe /c ver').then(function(stdout) { |
116 | if (/Windows XP/.test(stdout)) { |
117 | // TODO: Try to read these values from the registry. |
118 | return {min: 1025, max: 5000}; |
119 | } else { |
120 | return execute('netsh int ipv4 show dynamicport tcp'). |
121 | then(function(stdout) { |
122 | /* > netsh int ipv4 show dynamicport tcp |
123 | Protocol tcp Dynamic Port Range |
124 | --------------------------------- |
125 | Start Port : 49152 |
126 | Number of Ports : 16384 |
127 | */ |
128 | var range = stdout.split(/\n/).filter(function(line) { |
129 | return /.*:\s*\d+/.test(line); |
130 | }).map(function(line) { |
131 | return Number(line.split(/:\s*/)[1]); |
132 | }); |
133 | |
134 | return { |
135 | min: range[0], |
136 | max: range[0] + range[1] |
137 | }; |
138 | }); |
139 | } |
140 | }); |
141 | } |
142 | |
143 | |
144 | /** |
145 | * Tests if a port is free. |
146 | * @param {number} port The port to test. |
147 | * @param {string=} opt_host The bound host to test the {@code port} against. |
148 | * Defaults to {@code INADDR_ANY}. |
149 | * @return {!webdriver.promise.Promise.<boolean>} A promise that will resolve |
150 | * with whether the port is free. |
151 | */ |
152 | function isFree(port, opt_host) { |
153 | var result = promise.defer(function() { |
154 | server.cancel(); |
155 | }); |
156 | |
157 | var server = net.createServer().on('error', function(e) { |
158 | if (e.code === 'EADDRINUSE') { |
159 | result.fulfill(false); |
160 | } else { |
161 | result.reject(e); |
162 | } |
163 | }); |
164 | |
165 | server.listen(port, opt_host, function() { |
166 | server.close(function() { |
167 | result.fulfill(true); |
168 | }); |
169 | }); |
170 | |
171 | return result.promise; |
172 | } |
173 | |
174 | |
175 | /** |
176 | * @param {string=} opt_host The bound host to test the {@code port} against. |
177 | * Defaults to {@code INADDR_ANY}. |
178 | * @return {!webdriver.promise.Promise.<number>} A promise that will resolve |
179 | * to a free port. If a port cannot be found, the promise will be |
180 | * rejected. |
181 | */ |
182 | function findFreePort(opt_host) { |
183 | return findSystemPortRange().then(function(range) { |
184 | var attempts = 0; |
185 | var deferredPort = promise.defer(); |
186 | findPort(); |
187 | return deferredPort.promise; |
188 | |
189 | function findPort() { |
190 | attempts += 1; |
191 | if (attempts > 10) { |
192 | deferredPort.reject(Error('Unable to find a free port')); |
193 | } |
194 | |
195 | var port = Math.floor( |
196 | Math.random() * (range.max - range.min) + range.min); |
197 | isFree(port, opt_host).then(function(isFree) { |
198 | if (isFree) { |
199 | deferredPort.fulfill(port); |
200 | } else { |
201 | findPort(); |
202 | } |
203 | }); |
204 | } |
205 | }); |
206 | } |
207 | |
208 | |
209 | // PUBLIC API |
210 | |
211 | |
212 | exports.findFreePort = findFreePort; |
213 | exports.isFree = isFree; |