|
| 1 | +'use strict'; |
| 2 | + |
| 3 | +// Regression test for a keep-alive socket reuse race condition. |
| 4 | +// |
| 5 | +// The race is between responseOnEnd() and requestOnFinish(), both of which |
| 6 | +// can call responseKeepAlive(). The window is: req.end() has been called, |
| 7 | +// the socket write has completed (writableFinished true), but the write |
| 8 | +// callback that emits the 'finish' event has not fired yet. |
| 9 | +// |
| 10 | +// With plain HTTP the window is normally too narrow to hit. This test |
| 11 | +// widens it by delaying every client-socket write *callback* by a few |
| 12 | +// milliseconds (the actual I/O is not delayed, so writableFinished becomes |
| 13 | +// true while the 'finish'-emitting callback is still pending). |
| 14 | +// |
| 15 | +// With Expect: 100-continue, the server responds quickly while the client |
| 16 | +// delays req.end() just slightly (setTimeout 0), creating the perfect |
| 17 | +// timing for the response to arrive in that window. |
| 18 | +// |
| 19 | +// On unpatched Node, the double responseKeepAlive() call corrupts the |
| 20 | +// socket by stripping a subsequent request's listeners and emitting a |
| 21 | +// spurious 'free' event, causing requests to hang / time out. |
| 22 | + |
| 23 | +const common = require('../common'); |
| 24 | +const assert = require('assert'); |
| 25 | +const http = require('http'); |
| 26 | + |
| 27 | +const REQUEST_COUNT = 100; |
| 28 | +const agent = new http.Agent({ keepAlive: true, maxSockets: 1 }); |
| 29 | + |
| 30 | +// Delay every write *callback* on the client socket so that |
| 31 | +// socket.writableLength drops to 0 (writableFinished becomes true) before |
| 32 | +// the callback that ultimately emits the 'finish' event fires. With |
| 33 | +// HTTPS the TLS layer provides this gap naturally; for plain HTTP we |
| 34 | +// need to create it artificially. |
| 35 | +const patchedSockets = new WeakSet(); |
| 36 | +function patchSocket(socket) { |
| 37 | + if (patchedSockets.has(socket)) return; |
| 38 | + patchedSockets.add(socket); |
| 39 | + const delay = 5; |
| 40 | + const origWrite = socket.write; |
| 41 | + socket.write = function(chunk, encoding, cb) { |
| 42 | + if (typeof encoding === 'function') { |
| 43 | + cb = encoding; |
| 44 | + encoding = null; |
| 45 | + } |
| 46 | + if (typeof cb === 'function') { |
| 47 | + const orig = cb; |
| 48 | + cb = (...args) => setTimeout(() => orig(...args), delay); |
| 49 | + } |
| 50 | + return origWrite.call(this, chunk, encoding, cb); |
| 51 | + }; |
| 52 | +} |
| 53 | + |
| 54 | +const server = http.createServer(common.mustCall((req, res) => { |
| 55 | + req.on('error', common.mustNotCall()); |
| 56 | + res.writeHead(200); |
| 57 | + res.end(); |
| 58 | +}, REQUEST_COUNT)); |
| 59 | + |
| 60 | +server.listen(0, common.mustCall(() => { |
| 61 | + const { port } = server.address(); |
| 62 | + |
| 63 | + async function run() { |
| 64 | + try { |
| 65 | + for (let i = 0; i < REQUEST_COUNT; i++) { |
| 66 | + await sendRequest(port); |
| 67 | + } |
| 68 | + } finally { |
| 69 | + agent.destroy(); |
| 70 | + server.close(); |
| 71 | + } |
| 72 | + } |
| 73 | + |
| 74 | + run().then(common.mustCall()); |
| 75 | +})); |
| 76 | + |
| 77 | +function sendRequest(port) { |
| 78 | + let timeout; |
| 79 | + const promise = new Promise((resolve, reject) => { |
| 80 | + function done(err) { |
| 81 | + clearTimeout(timeout); |
| 82 | + if (err) |
| 83 | + reject(err); |
| 84 | + else |
| 85 | + resolve(); |
| 86 | + } |
| 87 | + |
| 88 | + const req = http.request({ |
| 89 | + port, |
| 90 | + host: '127.0.0.1', |
| 91 | + method: 'POST', |
| 92 | + agent, |
| 93 | + headers: { |
| 94 | + 'Content-Length': '0', |
| 95 | + 'Expect': '100-continue', |
| 96 | + }, |
| 97 | + }, common.mustCall((res) => { |
| 98 | + assert.strictEqual(res.statusCode, 200); |
| 99 | + res.resume(); |
| 100 | + res.once('end', done); |
| 101 | + res.once('error', done); |
| 102 | + })); |
| 103 | + |
| 104 | + req.on('socket', patchSocket); |
| 105 | + |
| 106 | + timeout = setTimeout(() => { |
| 107 | + const err = new Error('request timed out'); |
| 108 | + req.destroy(err); |
| 109 | + done(err); |
| 110 | + }, common.platformTimeout(5000)); |
| 111 | + |
| 112 | + req.once('error', done); |
| 113 | + |
| 114 | + setTimeout(() => req.end(Buffer.alloc(0)), 0); |
| 115 | + }); |
| 116 | + return promise.finally(() => clearTimeout(timeout)); |
| 117 | +} |