If an idle socket has received data unexpectedly, we...

net/base/ssl_client_socket_nss.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/base/ssl_client_socket_nss.h"
 
 #include <nspr.h>
 #include <nss.h>
 #include <secerr.h>
 // Work around https://bugzilla.mozilla.org/show_bug.cgi?id=455424
@@ skipping 147 matching lines @@
   if (nss_fd_ != NULL) {
     PR_Close(nss_fd_);
     nss_fd_ = NULL;
   }
   completed_handshake_ = false;
   transport_->Disconnect();
   LeaveFunction("");
 }
 
 bool SSLClientSocketNSS::IsConnected() const {
+  // Ideally, we should also check if we have received the close_notify alert
+  // message from the server, and return false in that case.  We're not doing
+  // that, so this function may return a false positive.  Since the upper
+  // layer (HttpNetworkTransaction) needs to handle a persistent connection
+  // closed by the server when we send a request anyway, a false positive in
+  // exchange for simpler code is a good trade-off.
   EnterFunction("");
   bool ret = completed_handshake_ && transport_->IsConnected();
   LeaveFunction("");
   return ret;
 }
 
+bool SSLClientSocketNSS::IsConnectedAndIdle() const {
+  // Unlike IsConnected, this method doesn't return a false positive.
+  //
+  // Strictly speaking, we should check if we have received the close_notify
+  // alert message from the server, and return false in that case.  Although
+  // the close_notify alert message means EOF in the SSL layer, it is just
+  // bytes to the transport layer below, so transport_->IsConnectedAndIdle()
+  // returns the desired false when we receive close_notify.
+  EnterFunction("");
+  bool ret = completed_handshake_ && transport_->IsConnectedAndIdle();
+  LeaveFunction("");
+  return ret;
+}
+
 int SSLClientSocketNSS::Read(char* buf, int buf_len,
                              CompletionCallback* callback) {
   EnterFunction(buf_len);
   DCHECK(completed_handshake_);
   DCHECK(next_state_ == STATE_NONE);
   DCHECK(!user_callback_);
   DCHECK(!user_buf_);
 
   user_buf_ = buf;
   user_buf_len_ = buf_len;
@@ skipping 375 matching lines @@
     GotoState(STATE_PAYLOAD_WRITE);
     return ERR_IO_PENDING;
   }
   user_buf_ = NULL;
   LeaveFunction("");
   return NetErrorFromNSPRError(prerr);
 }
 
 }  // namespace net