Close SSLClientSocketOpenSSL cleanly if the transport was closed.

net/socket/ssl_client_socket_openssl.cc

 // Copyright (c) 2012 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.
 
 // OpenSSL binding for SSLClientSocket. The class layout and general principle
 // of operation is derived from SSLClientSocketNSS.
 
 #include "net/socket/ssl_client_socket_openssl.h"
 
 #include <errno.h>
@@ skipping 1345 matching lines @@
       pending_read_error_ = rv;
       rv = total_bytes_read;
       next_result = &pending_read_error_;
     }
 
     if (client_auth_cert_needed_) {
       *next_result = ERR_SSL_CLIENT_AUTH_CERT_NEEDED;
     } else if (*next_result < 0) {
       int err = SSL_get_error(ssl_, *next_result);
       *next_result = MapOpenSSLError(err, err_tracer);
+
+      // Many servers do not reliably send a close_notify alert when shutting
+      // down a connection, and instead terminate the TCP connection. This is
+      // reported as ERR_CONNECTION_CLOSED. Because of this, map the unclean
+      // shutdown to a graceful EOF, instead of treating it as an error as it
+      // should be.
+      if (*next_result == ERR_CONNECTION_CLOSED)
+        *next_result = 0;
+
       if (rv > 0 && *next_result == ERR_IO_PENDING) {
           // If at least some data was read from SSL_read(), do not treat
           // insufficient data as an error to return in the next call to
           // DoPayloadRead() - instead, let the call fall through to check
           // SSL_read() again. This is because DoTransportIO() may complete
           // in between the next call to DoPayloadRead(), and thus it is
           // important to check SSL_read() on subsequent invocations to see
           // if a complete record may now be read.
         *next_result = kNoPendingReadResult;
       }
@@ skipping 395 matching lines @@
                                             ct::SCT_STATUS_LOG_UNKNOWN));
   }
 }
 
 scoped_refptr<X509Certificate>
 SSLClientSocketOpenSSL::GetUnverifiedServerCertificateChain() const {
   return server_cert_;
 }
 
 }  // namespace net