Fix instability in SSL client/server sockets

net/socket/ssl_server_socket_nss.cc

 // Copyright (c) 2011 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/socket/ssl_server_socket_nss.h"
 
 #if defined(OS_WIN)
 #include <winsock2.h>
 #endif
 
@@ skipping 510 matching lines @@
     char *buf;
     memio_GetReadParams(nss_bufs_, &buf);
     memcpy(buf, recv_buffer_->data(), result);
   }
   recv_buffer_ = NULL;
   memio_PutReadResult(nss_bufs_, MapErrorToNSS(result));
   transport_recv_busy_ = false;
   OnRecvComplete(result);
 }
 
-// Do network I/O between the given buffer and the given socket.
-// Return true if some I/O performed, false otherwise (error or ERR_IO_PENDING)
+// Do as much network I/O as possible between the buffer and the
+// transport socket. Return true if some I/O performed, false
+// otherwise (error or ERR_IO_PENDING).
 bool SSLServerSocketNSS::DoTransportIO() {
   bool network_moved = false;
   if (nss_bufs_ != NULL) {
-    int nsent = BufferSend();
-    int nreceived = BufferRecv();
-    network_moved = (nsent > 0 || nreceived >= 0);
+    int rv;
+    // Read and write as much data as we can. The loop is neccessary
+    // because Write() may return synchronously.
+    do {
+      rv = BufferSend();
+      if (rv > 0)
+        network_moved = true;
+    } while (rv > 0);
+    if (BufferRecv() >= 0)
+      network_moved = true;
   }
   return network_moved;
 }
 
 int SSLServerSocketNSS::DoPayloadRead() {
   DCHECK(user_read_buf_);
   DCHECK_GT(user_read_buf_len_, 0);
   int rv = PR_Read(nss_fd_, user_read_buf_->data(), user_read_buf_len_);
   if (rv >= 0)
     return rv;
@@ skipping 192 matching lines @@
   // We must call EnsureOCSPInit() here, on the IO thread, to get the IO loop
   // by MessageLoopForIO::current().
   // X509Certificate::Verify() runs on a worker thread of CertVerifier.
   EnsureOCSPInit();
 #endif
 
   return OK;
 }
 
 }  // namespace net