net: Destroy when not readable and not writable

This is only relevant for CentOS 6.3 using kernel version 2.6.32.

On other linuxes and darwin, the `read` call gets an ECONNRESET in that
case.  On sunos, the `write` call fails with EPIPE.

However, old CentOS will occasionally send an EOF instead of a
ECONNRESET or EPIPE when the client has been destroyed abruptly.

Make sure we don't keep trying to write or read more in that case.

Fixes #5504

However, there is still the question of what libuv should do when it
gets an EOF.  Apparently in this case, it will continue trying to read,
which is almost certainly the wrong thing to do.

That should be fixed in libuv, even though this works around the issue.

1 files changed, 18 insertions, 2 deletions

diff --git a/lib/net.js b/lib/net.js
index 7f6f306b84..620fd29a32 100644
--- a/lib/net.js
+++ b/lib/net.js
@@ -249,9 +249,11 @@ function onSocketEnd() {
   this._readableState.ended = true;
   if (this._readableState.endEmitted) {
     this.readable = false;
+    maybeDestroy(this);
   } else {
     this.once('end', function() {
       this.readable = false;
+      maybeDestroy(this);
     });
     this.read(0);
   }
@@ -399,10 +401,22 @@ Socket.prototype.end = function(data, encoding) {
   // just in case we're waiting for an EOF.
   if (this.readable && !this._readableState.endEmitted)
     this.read(0);
-  return;
+  else
+    maybeDestroy(this);
 };
 
 
+// Call whenever we set writable=false or readable=false
+function maybeDestroy(socket) {
+  if (!socket.readable &&
+      !socket.writable &&
+      !socket.destroyed &&
+      !socket._connecting) {
+    socket.destroy();
+  }
+}
+
+
 Socket.prototype.destroySoon = function() {
   if (this.writable)
     this.end();
@@ -521,8 +535,10 @@ function onread(buffer, offset, length) {
   } else if (process._errno == 'EOF') {
     debug('EOF');
 
-    if (self._readableState.length === 0)
+    if (self._readableState.length === 0) {
       self.readable = false;
+      maybeDestroy(self);
+    }
 
     if (self.onend) self.once('end', self.onend);