net: throw on invalid socket timeouts

This commit restricts socket timeouts non-negative, finite
numbers. Any other value throws a TypeError or RangeError.
This prevents subtle bugs that can happen due to type
coercion.

Fixes: https://github.com/joyent/node/issues/8618
PR-URL: https://github.com/joyent/node/pull/8884
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Timothy J Fontaine <tjfontaine@gmail.com>

lib/net.js

@@ -320,17 +320,17 @@ Socket.prototype.listen = function() {
 
 
 Socket.prototype.setTimeout = function(msecs, callback) {
-  if (msecs > 0 && isFinite(msecs)) {
+  if (msecs === 0) {
+    timers.unenroll(this);
+    if (callback) {
+      this.removeListener('timeout', callback);
+    }
+  } else {
     timers.enroll(this, msecs);
     timers._unrefActive(this);
     if (callback) {
       this.once('timeout', callback);
     }
-  } else if (msecs === 0) {
-    timers.unenroll(this);
-    if (callback) {
-      this.removeListener('timeout', callback);
-    }
   }
 };
 

lib/timers.js

@@ -28,7 +28,8 @@ var kOnTimeout = Timer.kOnTimeout | 0;
 // Timeout values > TIMEOUT_MAX are set to 1.
 var TIMEOUT_MAX = 2147483647; // 2^31-1
 
-var debug = require('util').debuglog('timer');
+var util = require('util');
+var debug = util.debuglog('timer');
 
 
 // IDLE TIMEOUTS
@@ -151,13 +152,21 @@ var unenroll = exports.unenroll = function(item) {
 
 // Does not start the time, just sets up the members needed.
 exports.enroll = function(item, msecs) {
+  if (!util.isNumber(msecs)) {
+    throw new TypeError('msecs must be a number');
+  }
+
+  if (msecs < 0 || !isFinite(msecs)) {
+    throw new RangeError('msecs must be a non-negative finite number');
+  }
+
   // if this item was already in a list somewhere
   // then we should unenroll it from that
   if (item._idleNext) unenroll(item);
 
   // Ensure that msecs fits into signed int32
-  if (msecs > 0x7fffffff) {
-    msecs = 0x7fffffff;
+  if (msecs > TIMEOUT_MAX) {
+    msecs = TIMEOUT_MAX;
   }
 
   item._idleTimeout = msecs;

test/simple/test-net-settimeout.js

@@ -33,7 +33,7 @@ var server = net.createServer(function(c) {
 });
 server.listen(common.PORT);
 
-var killers = [0, Infinity, NaN];
+var killers = [0];
 
 var left = killers.length;
 killers.forEach(function(killer) {

test/simple/test-net-socket-timeout.js

@@ -23,6 +23,31 @@ var common = require('../common');
 var net = require('net');
 var assert = require('assert');
 
+// Verify that invalid delays throw
+var noop = function() {};
+var s = new net.Socket();
+var nonNumericDelays = ['100', true, false, undefined, null, '', {}, noop, []];
+var badRangeDelays = [-0.001, -1, -Infinity, Infinity, NaN];
+var validDelays = [0, 0.001, 1, 1e6];
+
+for (var i = 0; i < nonNumericDelays.length; i++) {
+  assert.throws(function() {
+    s.setTimeout(nonNumericDelays[i], noop);
+  }, TypeError);
+}
+
+for (var i = 0; i < badRangeDelays.length; i++) {
+  assert.throws(function() {
+    s.setTimeout(badRangeDelays[i], noop);
+  }, RangeError);
+}
+
+for (var i = 0; i < validDelays.length; i++) {
+  assert.doesNotThrow(function() {
+    s.setTimeout(validDelays[i], noop);
+  });
+}
+
 var timedout = false;
 
 var server = net.Server();