SSLClientSocket::IsConnected should care for internal buffers

net/socket/ssl_client_socket_nss.cc

Index: net/socket/ssl_client_socket_nss.cc
diff --git a/net/socket/ssl_client_socket_nss.cc b/net/socket/ssl_client_socket_nss.cc
index 809dbc5beb28ce36b36e1e76c8ef4141a24eb715..90cc7e524395f2f6ef950c0044d37fe1c843306c 100644
--- a/net/socket/ssl_client_socket_nss.cc
+++ b/net/socket/ssl_client_socket_nss.cc
@@ -642,6 +642,11 @@ class SSLClientSocketNSS::Core : public base::RefCountedThreadSafe<Core> {
   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 IsConnected();
+  bool HasPendingAsyncOperation();
+  bool HasUnhandledReceivedData();
+
  private:
   friend class base::RefCountedThreadSafe<Core>;
   ~Core();
@@ -652,6 +657,12 @@ class SSLClientSocketNSS::Core : public base::RefCountedThreadSafe<Core> {
     STATE_GET_DOMAIN_BOUND_CERT_COMPLETE,
   };
 
+  enum Operation {
+    OPERATION_READ,
+    OPERATION_WRITE,
+    OPERATION_UPDATE,
+  };
+
   bool OnNSSTaskRunner() const;
   bool OnNetworkTaskRunner() const;
 
@@ -740,6 +751,10 @@ class SSLClientSocketNSS::Core : public base::RefCountedThreadSafe<Core> {
   void DoConnectCallback(int result);
   void DoReadCallback(int result);
   void DoWriteCallback(int result);
+  void UpdateNSSTaskRunnerStatus(int amount_in_read_buffer,
+                                 bool closed,
+                                 Operation operation,
+                                 const base::Closure& callback);
 
   // Client channel ID handler.
   static SECStatus ClientChannelIDHandler(
@@ -817,6 +832,12 @@ class SSLClientSocketNSS::Core : public base::RefCountedThreadSafe<Core> {
   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:
   ////////////////////////////////////////////////////////////////////////////
@@ -896,6 +917,10 @@ SSLClientSocketNSS::Core::Core(
       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),
@@ -1094,6 +1119,8 @@ int SSLClientSocketNSS::Core::Read(IOBuffer* buf, int buf_len,
         FROM_HERE,
         base::Bind(IgnoreResult(&Core::Read), this, make_scoped_refptr(buf),
                    buf_len, callback));
+    if (!posted)
+      nss_is_closed_ = true;

[Ryan Sleevi, 2013/01/21 16:33:29]

BUG: Wrong thread here

[Ryan Sleevi, 2013/01/22 02:48:05]

Er, this one was right

     return posted ? ERR_IO_PENDING : ERR_ABORTED;
   }
 
@@ -1104,6 +1131,7 @@ int SSLClientSocketNSS::Core::Read(IOBuffer* buf, int buf_len,
   DCHECK(user_connect_callback_.is_null());
   DCHECK(!user_read_buf_);
   DCHECK(nss_bufs_);
+  DCHECK(!nss_waiting_read_);

[Ryan Sleevi, 2013/01/21 16:33:29]

BUG: Wrong thread here

[Takashi Toyoshima, 2013/01/22 14:16:50]

Done.

 
   user_read_buf_ = buf;
   user_read_buf_len_ = buf_len;
@@ -1111,6 +1139,7 @@ int SSLClientSocketNSS::Core::Read(IOBuffer* buf, int buf_len,
   int rv = DoReadLoop(OK);
   if (rv == ERR_IO_PENDING) {
     user_read_callback_ = callback;
+    nss_waiting_read_ = true;

[Ryan Sleevi, 2013/01/21 16:33:29]

BUG: Wrong thread here

[Takashi Toyoshima, 2013/01/22 14:16:50]

Done.

   } else {
     user_read_buf_ = NULL;
     user_read_buf_len_ = 0;
@@ -1119,6 +1148,9 @@ int SSLClientSocketNSS::Core::Read(IOBuffer* buf, int buf_len,
       PostOrRunCallback(FROM_HERE, base::Bind(callback, rv));
       return ERR_IO_PENDING;
     }
+
+    if (rv <= 0)
+      nss_is_closed_ = true;

[Ryan Sleevi, 2013/01/21 16:33:29]

BUG: Wrong thread here

[Takashi Toyoshima, 2013/01/22 14:16:50]

Done.

   }
 
   return rv;
@@ -1136,6 +1168,8 @@ int SSLClientSocketNSS::Core::Write(IOBuffer* buf, int buf_len,
         base::Bind(IgnoreResult(&Core::Write), this, make_scoped_refptr(buf),
                    buf_len, callback));
     int rv = posted ? ERR_IO_PENDING : ERR_ABORTED;
+    if (!posted)
+      nss_is_closed_ = true;

[Ryan Sleevi, 2013/01/21 16:33:29]

BUG: Wrong thread here

[Ryan Sleevi, 2013/01/22 02:48:05]

as was this one

[Takashi Toyoshima, 2013/01/22 14:16:50]

Done.

     return rv;
   }
 
@@ -1146,6 +1180,7 @@ int SSLClientSocketNSS::Core::Write(IOBuffer* buf, int buf_len,
   DCHECK(user_connect_callback_.is_null());
   DCHECK(!user_write_buf_);
   DCHECK(nss_bufs_);
+  DCHECK(!nss_waiting_write_);

[Ryan Sleevi, 2013/01/21 16:33:29]

BUG: Wrong thread here

[Takashi Toyoshima, 2013/01/22 14:16:50]

Done.

 
   user_write_buf_ = buf;
   user_write_buf_len_ = buf_len;
@@ -1153,6 +1188,7 @@ int SSLClientSocketNSS::Core::Write(IOBuffer* buf, int buf_len,
   int rv = DoWriteLoop(OK);
   if (rv == ERR_IO_PENDING) {
     user_write_callback_ = callback;
+    nss_waiting_write_ = true;

[Ryan Sleevi, 2013/01/21 16:33:29]

BUG: Wrong thread here

[Takashi Toyoshima, 2013/01/22 14:16:50]

Done.

   } else {
     user_write_buf_ = NULL;
     user_write_buf_len_ = 0;
@@ -1161,11 +1197,28 @@ int SSLClientSocketNSS::Core::Write(IOBuffer* buf, int buf_len,
       PostOrRunCallback(FROM_HERE, base::Bind(callback, rv));
       return ERR_IO_PENDING;
     }
+
+    if (rv < 0)
+      nss_is_closed_ = true;

[Ryan Sleevi, 2013/01/21 16:33:29]

BUG: Wrong thread here

[Takashi Toyoshima, 2013/01/22 14:16:50]

Done.

   }
 
   return rv;
 }
 
+bool SSLClientSocketNSS::Core::IsConnected() {
+  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();
 }
@@ -2044,6 +2097,17 @@ int SSLClientSocketNSS::Core::DoPayloadRead() {
   DCHECK_GT(user_read_buf_len_, 0);
 
   int rv = PR_Read(nss_fd_, user_read_buf_->data(), user_read_buf_len_);
+  // Update NSSTaskRunner status because PR_Read may consume |nss_bufs_|, then
+  // following |amount_in_read_buffer| may be changed here.
+  int amount_in_read_buffer = memio_GetReadableBufferSize(nss_bufs_);
+  base::Closure task = base::Bind(
+      &Core::UpdateNSSTaskRunnerStatus,
+      this,
+      amount_in_read_buffer,
+      rv <= 0 && rv != ERR_IO_PENDING,
+      OPERATION_UPDATE,
+      base::Closure());
+
   if (client_auth_cert_needed_) {
     // We don't need to invalidate the non-client-authenticated SSL session
     // because the server will renegotiate anyway.
@@ -2081,7 +2145,21 @@ int SSLClientSocketNSS::Core::DoPayloadWrite() {
 
   DCHECK(user_write_buf_);
 
+  int old_amount_in_read_buffer = memio_GetReadableBufferSize(nss_bufs_);
   int rv = PR_Write(nss_fd_, user_write_buf_->data(), user_write_buf_len_);
+  int new_amount_in_read_buffer = memio_GetReadableBufferSize(nss_bufs_);
+  // PR_Write could potentially consume the unhandled data in the memio read
+  // buffer if a renegotiation is in progress. If the buffer is consumed,
+  // notify the latest buffer size to NetworkRunner.
+  if (old_amount_in_read_buffer != new_amount_in_read_buffer) {
+    base::Closure task = base::Bind(
+        &Core::UpdateNSSTaskRunnerStatus,
+        this,
+        new_amount_in_read_buffer,
+        false,
+        OPERATION_UPDATE,
+        base::Closure());
+  }
   if (rv >= 0) {
     PostOrRunCallback(
         FROM_HERE,
@@ -2287,10 +2365,20 @@ void SSLClientSocketNSS::Core::DoReadCallback(int rv) {
 
   user_read_buf_ = NULL;
   user_read_buf_len_ = 0;
-  base::Closure c = base::Bind(
-      base::ResetAndReturn(&user_read_callback_),
-      rv);
-  PostOrRunCallback(FROM_HERE, c);
+  int amount_in_read_buffer = memio_GetReadableBufferSize(nss_bufs_);
+  // 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.
+      OPERATION_READ,
+      user_cb);
+  PostOrRunCallback(FROM_HERE, task);
 }
 
 void SSLClientSocketNSS::Core::DoWriteCallback(int rv) {
@@ -2302,10 +2390,45 @@ void SSLClientSocketNSS::Core::DoWriteCallback(int rv) {
   // 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);
+  // Update buffer status because DoWriteLoop called DoTransportIO which may
+  // perform read operations.
+  int amount_in_read_buffer = memio_GetReadableBufferSize(nss_bufs_);
+  // 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.
+      OPERATION_WRITE,
+      user_cb);
+  PostOrRunCallback(FROM_HERE, task);
+}
+
+void SSLClientSocketNSS::Core::UpdateNSSTaskRunnerStatus(

[Takashi Toyoshima, 2013/01/22 14:16:50]

I renamed it as OnNSSTaskRunnerStateUpdated() to follow other functions and
moved to proper place for functions working in NetworkTaskRunner.

+    int amount_in_read_buffer,
+    bool closed,
+    Operation operation,
+    const base::Closure& callback) {
+  DCHECK(OnNetworkTaskRunner());
+  DCHECK(operation == OPERATION_UPDATE || !callback.is_null());
+  DCHECK((operation == OPERATION_READ && nss_waiting_read_) ||
+         (operation == OPERATION_WRITE && nss_waiting_write_) ||
+         operation == OPERATION_UPDATE);
+
+  unhandled_buffer_size_ = amount_in_read_buffer;
+  if (closed)
+    nss_is_closed_ = true;
+  if (operation == OPERATION_READ)
+    nss_waiting_read_ = false;
+  else if (operation == OPERATION_WRITE)
+    nss_waiting_write_ = false;
+
+  if (operation != OPERATION_UPDATE)
+    callback.Run();
 }
 
 SECStatus SSLClientSocketNSS::Core::ClientChannelIDHandler(
@@ -2922,29 +3045,21 @@ void SSLClientSocketNSS::Disconnect() {
 }
 
 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_ &&
+             (core_->HasPendingAsyncOperation() ||
+              core_->HasUnhandledReceivedData() ||
+              core_->IsConnected() ||

[Ryan Sleevi, 2013/01/21 16:33:29]

This logic change isn't correct. You're short-circuiting to "true" when
1) There's no pending operation
2) There's no pending operation
3) The NSS core thinks its connected (which is to say: The NSS core has not
received an explicit disconnect)

Compare this with your logic on 3060-3062.

core_->HasPendingAsyncOperation() || (core_->IsConnected() &&
core_->HasUnhandledReceivedData()) || transport_->socket()->IsConnected()

[Takashi Toyoshima, 2013/01/22 14:16:50]

Thank you.
I was confused on how to handle transport IsConnected().

+              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_->IsConnected() && core_->HasUnhandledReceivedData()) &&
+             transport_->socket()->IsConnectedAndIdle();
   LeaveFunction("");
   return ret;
 }