SSLClientSocket::IsConnected should care for internal buffers

net/socket/ssl_client_socket_nss.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.
 
 // This file includes code SSLClientSocketNSS::DoVerifyCertComplete() derived
 // from AuthCertificateCallback() in
 // mozilla/security/manager/ssl/src/nsNSSCallbacks.cpp.
 
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
@@ skipping 624 matching lines @@
   // any time.
   const HandshakeState& state() const { return network_handshake_state_; }
 
   // Called on the network task runner.
   // Read() and Write() mirror the net::Socket functions of the same name.
   // If ERR_IO_PENDING is returned, |callback| will be invoked on the network
   // task runner at a later point, unless the caller calls Detach().
   int Read(IOBuffer* buf, int buf_len, const CompletionCallback& callback);
   int Write(IOBuffer* buf, int buf_len, const CompletionCallback& callback);
 
+  // Called on the network task runner.
+  bool IsClosed();
+  bool HasPendingAsyncOperation();
+  bool HasUnhandledReceivedData();
+
  private:
   friend class base::RefCountedThreadSafe<Core>;
   ~Core();
 
   enum State {
     STATE_NONE,
     STATE_HANDSHAKE,
     STATE_GET_DOMAIN_BOUND_CERT_COMPLETE,
   };
 
@@ skipping 78 matching lines @@
   bool DoTransportIO();
   int BufferRecv();
   int BufferSend();
 
   void OnRecvComplete(int result);
   void OnSendComplete(int result);
 
   void DoConnectCallback(int result);
   void DoReadCallback(int result);
   void DoWriteCallback(int result);
+  void UpdateNSSTaskRunnerStatus(int amount_in_read_buffer,
+                                 bool closed,
+                                 bool operation_is_read,
+                                 const base::Closure& callback);
 
   // Client channel ID handler.
   static SECStatus ClientChannelIDHandler(
       void* arg,
       PRFileDesc* socket,
       SECKEYPublicKey **out_public_key,
       SECKEYPrivateKey **out_private_key);
 
   // ImportChannelIDKeys is a helper function for turning a DER-encoded cert and
   // key into a SECKEYPublicKey and SECKEYPrivateKey. Returns OK upon success
@@ skipping 57 matching lines @@
   ClientSocketHandle* transport_;
   base::WeakPtrFactory<BoundNetLog> weak_net_log_factory_;
 
   // The current handshake state. Mirrors |nss_handshake_state_|.
   HandshakeState network_handshake_state_;
 
   // The service for retrieving Channel ID keys.  May be NULL.
   ServerBoundCertService* server_bound_cert_service_;
   ServerBoundCertService::RequestHandle domain_bound_cert_request_handle_;
 
+  // The information about NSS task runner.
+  int unhandled_buffer_size_;
+  bool nss_waiting_read_;
+  bool nss_waiting_write_;
+  bool nss_is_closed_;
+
   ////////////////////////////////////////////////////////////////////////////
   // Members that are ONLY accessed on the NSS task runner:
   ////////////////////////////////////////////////////////////////////////////
   HostPortPair host_and_port_;
   SSLConfig ssl_config_;
 
   // NSS SSL socket.
   PRFileDesc* nss_fd_;
 
   // Buffers for the network end of the SSL state machine
@@ skipping 59 matching lines @@
     base::SequencedTaskRunner* nss_task_runner,
     ClientSocketHandle* transport,
     const HostPortPair& host_and_port,
     const SSLConfig& ssl_config,
     BoundNetLog* net_log,
     ServerBoundCertService* server_bound_cert_service)
     : detached_(false),
       transport_(transport),
       weak_net_log_factory_(net_log),
       server_bound_cert_service_(server_bound_cert_service),
+      unhandled_buffer_size_(0),
+      nss_waiting_read_(false),
+      nss_waiting_write_(false),
+      nss_is_closed_(false),
       host_and_port_(host_and_port),
       ssl_config_(ssl_config),
       nss_fd_(NULL),
       nss_bufs_(NULL),
       next_handshake_state_(STATE_NONE),
       channel_id_xtn_negotiated_(false),
       channel_id_needed_(false),
       client_auth_cert_needed_(false),
       handshake_callback_called_(false),
       transport_recv_busy_(false),
@@ skipping 188 matching lines @@
     return posted ? ERR_IO_PENDING : ERR_ABORTED;
   }
 
   DCHECK(OnNSSTaskRunner());
   DCHECK(handshake_callback_called_);
   DCHECK_EQ(STATE_NONE, next_handshake_state_);
   DCHECK(user_read_callback_.is_null());
   DCHECK(user_connect_callback_.is_null());
   DCHECK(!user_read_buf_);
   DCHECK(nss_bufs_);
+  DCHECK(!nss_waiting_read_);
 
   user_read_buf_ = buf;
   user_read_buf_len_ = buf_len;
 
   int rv = DoReadLoop(OK);
   if (rv == ERR_IO_PENDING) {
     user_read_callback_ = callback;
+    nss_waiting_read_ = true;
   } else {
     user_read_buf_ = NULL;
     user_read_buf_len_ = 0;
 
     if (!OnNetworkTaskRunner()) {
       PostOrRunCallback(FROM_HERE, base::Bind(callback, rv));
       return ERR_IO_PENDING;
     }
   }
 
@@ skipping 15 matching lines @@
     return rv;
   }
 
   DCHECK(OnNSSTaskRunner());
   DCHECK(handshake_callback_called_);
   DCHECK_EQ(STATE_NONE, next_handshake_state_);
   DCHECK(user_write_callback_.is_null());
   DCHECK(user_connect_callback_.is_null());
   DCHECK(!user_write_buf_);
   DCHECK(nss_bufs_);
+  DCHECK(!nss_waiting_write_);
 
   user_write_buf_ = buf;
   user_write_buf_len_ = buf_len;
 
   int rv = DoWriteLoop(OK);
   if (rv == ERR_IO_PENDING) {
     user_write_callback_ = callback;
+    nss_waiting_write_ = true;
   } else {
     user_write_buf_ = NULL;
     user_write_buf_len_ = 0;
 
     if (!OnNetworkTaskRunner()) {
       PostOrRunCallback(FROM_HERE, base::Bind(callback, rv));
       return ERR_IO_PENDING;
     }
   }
 
   return rv;
 }
 
+bool SSLClientSocketNSS::Core::IsClosed() {
+  return nss_is_closed_;
+}
+
+bool SSLClientSocketNSS::Core::HasPendingAsyncOperation() {
+  DCHECK(OnNetworkTaskRunner());
+  return nss_waiting_read_ || nss_waiting_write_;
+}
+
+bool SSLClientSocketNSS::Core::HasUnhandledReceivedData() {
+  DCHECK(OnNetworkTaskRunner());
+  return unhandled_buffer_size_ != 0;
+}
+
 bool SSLClientSocketNSS::Core::OnNSSTaskRunner() const {
   return nss_task_runner_->RunsTasksOnCurrentThread();
 }
 
 bool SSLClientSocketNSS::Core::OnNetworkTaskRunner() const {
   return network_task_runner_->RunsTasksOnCurrentThread();
 }
 
 // static
 SECStatus SSLClientSocketNSS::Core::OwnAuthCertHandler(
@@ skipping 857 matching lines @@
   SetChannelIDProvided();
   GotoState(STATE_HANDSHAKE);
   return OK;
 }
 
 int SSLClientSocketNSS::Core::DoPayloadRead() {
   DCHECK(OnNSSTaskRunner());
   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_);

[wtc, 2013/01/16 00:34:16]

PR_Read may consume the unhandled data in the memio read buffer.

So it seems that after the PR_Read call, we should also
update unhandled_buffer_size_.

Note: PR_Write could potentially also consume the unhandled
data in the memio read buffer if a renegotiation is in
progress.

[Takashi Toyoshima, 2013/01/16 07:16:03]

I define enum Operation type and use it in UpdateNSSTaskRunnerStatus. PR_Read
and PR_Write will use OPERATION_UPDATE to just update unhandled_buffer_size_.

I'm not sure when a renegotiation could happen. So, I check the size before and
after calling PR_Write, and notify the latest size iff the size is changed.

   if (client_auth_cert_needed_) {
     // We don't need to invalidate the non-client-authenticated SSL session
     // because the server will renegotiate anyway.
     rv = ERR_SSL_CLIENT_AUTH_CERT_NEEDED;
     PostOrRunCallback(
         FROM_HERE,
         base::Bind(&AddLogEventWithCallback, weak_net_log_,
                    NetLog::TYPE_SSL_READ_ERROR,
                    CreateNetLogSSLErrorCallback(rv, 0)));
     return rv;
@@ skipping 223 matching lines @@
   PostOrRunCallback(FROM_HERE, c);
 }
 
 void SSLClientSocketNSS::Core::DoReadCallback(int rv) {
   DCHECK(OnNSSTaskRunner());
   DCHECK_NE(ERR_IO_PENDING, rv);
   DCHECK(!user_read_callback_.is_null());
 
   user_read_buf_ = NULL;
   user_read_buf_len_ = 0;
-  base::Closure c = base::Bind(
-      base::ResetAndReturn(&user_read_callback_),
-      rv);
-  PostOrRunCallback(FROM_HERE, c);
+  char* buf;
+  int amount_in_read_buffer = memio_GetReadParams(nss_bufs_, &buf);

[wtc, 2013/01/16 00:34:16]

BUG(?): I believe this is wrong.

The return value of memio_GetReadParams() is the number of
bytes available to write into the read buffer, i.e., the
free space in the read buffer. So the amount of unhandled
data should be approximately
    kRecvBufferSize - memio_GetReadParams(nss_bufs_, &buf)

The reason I said "approximately" is that we may need to
subtract 1 because the read buffer is a circular buffer.

There is an internal function memio_buffer_used_contiguous(&secret->readbuf)
defined in net/base/nss_memio.c that we can use to get
the right value. We will need to expose it.

[Takashi Toyoshima, 2013/01/16 07:16:03]

Done.
I expose it as memio_GetReadableBufferSize().

+  // This will invoke the user callback with |rv| as result.
+  base::Closure user_cb = base::Bind(
+      base::ResetAndReturn(&user_read_callback_), rv);
+  // This is used to curry the |amount_int_read_buffer| and |user_cb| back to
+  // the network task runner.
+  base::Closure task = base::Bind(
+      &Core::UpdateNSSTaskRunnerStatus,
+      this,
+      amount_in_read_buffer,
+      rv <= 0,  // EOF or errors.
+      true,  // Operation is read.
+      user_cb);
+  PostOrRunCallback(FROM_HERE, task);
 }
 
 void SSLClientSocketNSS::Core::DoWriteCallback(int rv) {
   DCHECK(OnNSSTaskRunner());
   DCHECK_NE(ERR_IO_PENDING, rv);
   DCHECK(!user_write_callback_.is_null());
 
   // Since Run may result in Write being called, clear |user_write_callback_|
   // up front.
   user_write_buf_ = NULL;
   user_write_buf_len_ = 0;
-  base::Closure c = base::Bind(
-      base::ResetAndReturn(&user_write_callback_),
-      rv);
-  PostOrRunCallback(FROM_HERE, c);
+  char* buf;
+  // Update buffer status because DoWriteLoop called DoTransportIO which may
+  // perform read operations.
+  int amount_in_read_buffer = memio_GetReadParams(nss_bufs_, &buf);
+  // This will invoke the user callback with |rv| as result.
+  base::Closure user_cb = base::Bind(
+      base::ResetAndReturn(&user_write_callback_), rv);
+  // This is used to curry the |amount_int_read_buffer| and |user_cb| back to
+  // the network task runner.
+  base::Closure task = base::Bind(
+      &Core::UpdateNSSTaskRunnerStatus,
+      this,
+      amount_in_read_buffer,
+      rv < 0,  // Errors.
+      false,  // Operation is not read, but write.
+      user_cb);
+  PostOrRunCallback(FROM_HERE, task);
+}
+
+void SSLClientSocketNSS::Core::UpdateNSSTaskRunnerStatus(
+    int amount_in_read_buffer,
+    bool closed,
+    bool operation_is_read,
+    const base::Closure& callback) {
+  DCHECK(OnNetworkTaskRunner());
+  DCHECK(!callback.is_null());
+  DCHECK((operation_is_read && nss_waiting_read_) ||
+         (!operation_is_read && nss_waiting_write_));
+
+  unhandled_buffer_size_ = amount_in_read_buffer;
+  if (closed)
+    nss_is_closed_ = true;
+  if (operation_is_read)
+    nss_waiting_read_ = false;
+  else
+    nss_waiting_write_ = false;
+  callback.Run();
 }
 
 SECStatus SSLClientSocketNSS::Core::ClientChannelIDHandler(
     void* arg,
     PRFileDesc* socket,
     SECKEYPublicKey **out_public_key,
     SECKEYPrivateKey **out_private_key) {
   Core* core = reinterpret_cast<Core*>(arg);
   DCHECK(core->OnNSSTaskRunner());
 
@@ skipping 408 matching lines @@
     const SSLConfig& ssl_config,
     const SSLClientSocketContext& context)
     : nss_task_runner_(nss_task_runner),
       transport_(transport_socket),
       host_and_port_(host_and_port),
       ssl_config_(ssl_config),
       cert_verifier_(context.cert_verifier),
       server_bound_cert_service_(context.server_bound_cert_service),
       ssl_session_cache_shard_(context.ssl_session_cache_shard),
       completed_handshake_(false),
+      ssl_is_closed_(false),
       next_handshake_state_(STATE_NONE),
       nss_fd_(NULL),
       net_log_(transport_socket->socket()->NetLog()),
       transport_security_state_(context.transport_security_state),
       valid_thread_id_(base::kInvalidThreadId) {
   EnterFunction("");
   InitCore();
   LeaveFunction("");
 }
 
@@ skipping 168 matching lines @@
   user_connect_callback_.Reset();
   server_cert_verify_result_.Reset();
   completed_handshake_   = false;
   start_cert_verification_time_ = base::TimeTicks();
   InitCore();
 
   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_->socket()->IsConnected();
+  bool ret = completed_handshake_ &&
+             !ssl_is_closed_ &&
+             !core_->IsClosed() &&

[wtc, 2013/01/16 00:34:16]

Why do we need both ssl_is_closed_ and core_->IsClosed()?

[Takashi Toyoshima, 2013/01/16 07:16:03]

ssl_is_closed_ is for synchronous completion case, core_->IsClosed() is for
asynchronous completion case. Synchronous case should be handled for single
thread model.

But... these condition looks wrong?
Now I think HasPendingAsyncOperation should be handled at higher priority than
IsClosed() because pending async operation should be finished before the
detected EOF.

[Ryan Sleevi, 2013/01/18 00:03:24]

I'm not sure I understand this. Both synchronous and asynchronous use a core_
object. Why can that not be used consistently?

[Takashi Toyoshima, 2013/01/21 14:51:16]

OK, I move the logic for ssl_is_closed_ into core_ object.

+             (core_->HasPendingAsyncOperation() ||
+              core_->HasUnhandledReceivedData() ||
+              transport_->socket()->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_->socket()->IsConnectedAndIdle() returns the desired false
-  // when we receive close_notify.
   EnterFunction("");
-  bool ret = completed_handshake_ && transport_->socket()->IsConnectedAndIdle();
+  bool ret = IsConnected() &&
+             !core_->HasUnhandledReceivedData() &&
+             transport_->socket()->IsConnectedAndIdle();
   LeaveFunction("");
   return ret;
 }
 
 int SSLClientSocketNSS::GetPeerAddress(IPEndPoint* address) const {
   return transport_->socket()->GetPeerAddress(address);
 }
 
 int SSLClientSocketNSS::GetLocalAddress(IPEndPoint* address) const {
   return transport_->socket()->GetLocalAddress(address);
@@ skipping 51 matching lines @@
   return base::TimeDelta::FromMicroseconds(-1);
 }
 
 int SSLClientSocketNSS::Read(IOBuffer* buf, int buf_len,
                              const CompletionCallback& callback) {
   DCHECK(core_);
   DCHECK(!callback.is_null());
 
   EnterFunction(buf_len);
   int rv = core_->Read(buf, buf_len, callback);
+  if (rv <= 0 && rv != ERR_IO_PENDING)
+    ssl_is_closed_ = true;
   LeaveFunction(rv);
 
   return rv;
 }
 
 int SSLClientSocketNSS::Write(IOBuffer* buf, int buf_len,
                               const CompletionCallback& callback) {
   DCHECK(core_);
   DCHECK(!callback.is_null());
 
   EnterFunction(buf_len);
   int rv = core_->Write(buf, buf_len, callback);
+  if (rv < 0 && rv != ERR_IO_PENDING)
+    ssl_is_closed_ = true;
   LeaveFunction(rv);
 
   return rv;
 }
 
 bool SSLClientSocketNSS::SetReceiveBufferSize(int32 size) {
   return transport_->socket()->SetReceiveBufferSize(size);
 }
 
 bool SSLClientSocketNSS::SetSendBufferSize(int32 size) {
@@ skipping 450 matching lines @@
   EnsureThreadIdAssigned();
   base::AutoLock auto_lock(lock_);
   return valid_thread_id_ == base::PlatformThread::CurrentId();
 }
 
 ServerBoundCertService* SSLClientSocketNSS::GetServerBoundCertService() const {
   return server_bound_cert_service_;
 }
 
 }  // namespace net