extcap: Interface Toolbar support on Windows

Add support for extcap control pipes on Windows.
Improved read loop in InterfaceToolbarReader.
Delay opening control pipes until extcap has opened the fifo pipe.
Make extcap_example.py work on Windows.

Bug: 13833
Change-Id: I4b47d25452637759b8a3be53be48eee5365bc0e4
Reviewed-on: https://code.wireshark.org/review/23211
Petri-Dish: Stig Bjørlykke <stig@bjorlykke.org>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

15 files changed, 323 insertions, 138 deletions

diff --git a/AUTHORS.src b/AUTHORS.src
index 172a1a3f40..6e8bd4f44f 100644
--- a/AUTHORS.src
+++ b/AUTHORS.src
@@ -3955,6 +3955,7 @@ James Lynch		<lynch007[AT]gmail.com>
 Chidambaram Arunachalam	<carunach[AT]cisco.com>
 João Valverde		<joao.valverde[AT]tecnico.ulisboa.pt>
 Benoît Canet		<benoit[AT]scylladb.com>
+Håkon Øye Amundsen      <haakon.amundsen[AT]nordicsemi.no>
 
 Acknowledgements
 ------------
diff --git a/capture_opts.c b/capture_opts.c
index 0f7a88ee3f..4d63ba4d12 100644
--- a/capture_opts.c
+++ b/capture_opts.c
@@ -70,6 +70,8 @@ capture_opts_init(capture_options *capture_opts)
     capture_opts->default_options.extcap_pid      = INVALID_EXTCAP_PID;
 #ifdef _WIN32
     capture_opts->default_options.extcap_pipe_h   = INVALID_HANDLE_VALUE;
+    capture_opts->default_options.extcap_control_in_h  = INVALID_HANDLE_VALUE;
+    capture_opts->default_options.extcap_control_out_h = INVALID_HANDLE_VALUE;
 #endif
     capture_opts->default_options.extcap_control_in  = NULL;
     capture_opts->default_options.extcap_control_out = NULL;
@@ -718,6 +720,8 @@ capture_opts_add_iface_opt(capture_options *capture_opts, const char *optarg_str
     interface_opts.extcap_userdata = NULL;
 #ifdef _WIN32
     interface_opts.extcap_pipe_h = INVALID_HANDLE_VALUE;
+    interface_opts.extcap_control_in_h = INVALID_HANDLE_VALUE;
+    interface_opts.extcap_control_out_h = INVALID_HANDLE_VALUE;
 #endif
     interface_opts.extcap_control_in = g_strdup(capture_opts->default_options.extcap_control_in);
     interface_opts.extcap_control_out = g_strdup(capture_opts->default_options.extcap_control_out);
@@ -1234,6 +1238,8 @@ collect_ifaces(capture_options *capture_opts)
             interface_opts.extcap_userdata = NULL;
 #ifdef _WIN32
             interface_opts.extcap_pipe_h = INVALID_HANDLE_VALUE;
+            interface_opts.extcap_control_in_h = INVALID_HANDLE_VALUE;
+            interface_opts.extcap_control_out_h = INVALID_HANDLE_VALUE;
 #endif
             interface_opts.extcap_control_in = NULL;
             interface_opts.extcap_control_out = NULL;
diff --git a/capture_opts.h b/capture_opts.h
index 22d03c8472..311cc4ac97 100644
--- a/capture_opts.h
+++ b/capture_opts.h
@@ -238,6 +238,8 @@ typedef struct interface_options_tag {
     guint             extcap_child_watch;
 #ifdef _WIN32
     HANDLE            extcap_pipe_h;
+    HANDLE            extcap_control_in_h;
+    HANDLE            extcap_control_out_h;
 #endif
     gchar            *extcap_control_in;
     gchar            *extcap_control_out;
diff --git a/doc/README.extcap b/doc/README.extcap
index f1e27ce01c..3ce07aa161 100644
--- a/doc/README.extcap
+++ b/doc/README.extcap
@@ -356,7 +356,7 @@ Control packet:
   The common sync pipe indication. This protocol uses the value 'T'.
 
  Message Length:
-  Payload length + 2 bytes for argument number and command.
+  Payload length + 2 bytes for control number and command.
 
  Control Number:
    Unique number to identify the control.  This number also gives the order of
diff --git a/doc/extcap_example.py b/doc/extcap_example.py
index e984b374aa..9c14ddeae7 100755
--- a/doc/extcap_example.py
+++ b/doc/extcap_example.py
@@ -340,28 +340,22 @@ def extcap_capture(interface, fifo, control_in, control_out, in_delay, in_verify
 	message = in_message
 	verify = in_verify
 	counter = 1
-
-	if not os.path.exists(fifo):
-		print ( "Fifo does not exist, exiting!", file=sys.stderr )
-		sys.exit(1)
-
 	fn_out = None
-	if control_out != None:
-		fn_out = open(control_out, 'wb', 0)
-		control_write(fn_out, CTRL_ARG_LOGGER, CTRL_CMD_SET, "Log started at " + time.strftime("%c") + "\n")
 
+	with open(fifo, 'wb', 0 ) as fh:
+		fh.write (pcap_fake_header())
 
-	if control_in != None:
-		# Start reading thread
-		thread = Thread(target = control_read_thread, args = (control_in, fn_out))
-		thread.start()
+		if control_out != None:
+			fn_out = open(control_out, 'wb', 0)
+			control_write(fn_out, CTRL_ARG_LOGGER, CTRL_CMD_SET, "Log started at " + time.strftime("%c") + "\n")
 
+		if control_in != None:
+			# Start reading thread
+			thread = Thread(target = control_read_thread, args = (control_in, fn_out))
+			thread.start()
 
-	if fn_out != None:
-		control_write_defaults(fn_out)
-
-	with open(fifo, 'wb', 0 ) as fh:
-		fh.write (pcap_fake_header())
+		if fn_out != None:
+			control_write_defaults(fn_out)
 
 		while True:
 			if fn_out != None:
@@ -383,10 +377,6 @@ def extcap_capture(interface, fifo, control_in, control_out, in_delay, in_verify
 	        fn_out.close()
 
 def extcap_close_fifo(fifo):
-	if not os.path.exists(fifo):
-		print ( "Fifo does not exist!", file=sys.stderr )
-		return
-
 	# This is apparently needed to workaround an issue on Windows/macOS
 	# where the message cannot be read. (really?)
 	fh = open(fifo, 'wb', 0 )
diff --git a/extcap.c b/extcap.c
index d025c9fe25..e88edc8dbc 100644
--- a/extcap.c
+++ b/extcap.c
@@ -1041,6 +1041,24 @@ void extcap_if_cleanup(capture_options *capture_opts, gchar **errormsg)
             CloseHandle(interface_opts.extcap_pipe_h);
             interface_opts.extcap_pipe_h = INVALID_HANDLE_VALUE;
         }
+        if (interface_opts.extcap_control_in_h != INVALID_HANDLE_VALUE)
+        {
+            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG,
+                  "Extcap [%s] - Closing control_in pipe", interface_opts.name);
+            FlushFileBuffers(interface_opts.extcap_control_in_h);
+            DisconnectNamedPipe(interface_opts.extcap_control_in_h);
+            CloseHandle(interface_opts.extcap_control_in_h);
+            interface_opts.extcap_control_in_h = INVALID_HANDLE_VALUE;
+        }
+        if (interface_opts.extcap_control_out_h != INVALID_HANDLE_VALUE)
+        {
+            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG,
+                  "Extcap [%s] - Closing control_out pipe", interface_opts.name);
+            FlushFileBuffers(interface_opts.extcap_control_out_h);
+            DisconnectNamedPipe(interface_opts.extcap_control_out_h);
+            CloseHandle(interface_opts.extcap_control_out_h);
+            interface_opts.extcap_control_out_h = INVALID_HANDLE_VALUE;
+        }
 #else
         if (interface_opts.extcap_fifo != NULL && file_exists(interface_opts.extcap_fifo))
         {
@@ -1355,14 +1373,20 @@ extcap_init_interfaces(capture_options *capture_opts)
         if (extcap_has_toolbar(interface_opts.name))
         {
             extcap_create_pipe(interface_opts.name, &interface_opts.extcap_control_in,
-                               EXTCAP_CONTROL_IN_PREFIX);
+                               EXTCAP_CONTROL_IN_PREFIX, FALSE);
+#ifdef _WIN32
+            interface_opts.extcap_control_in_h = pipe_h;
+#endif
             extcap_create_pipe(interface_opts.name, &interface_opts.extcap_control_out,
-                               EXTCAP_CONTROL_OUT_PREFIX);
+                               EXTCAP_CONTROL_OUT_PREFIX, FALSE);
+#ifdef _WIN32
+            interface_opts.extcap_control_out_h = pipe_h;
+#endif
         }
 
         /* create pipe for fifo */
         if (!extcap_create_pipe(interface_opts.name, &interface_opts.extcap_fifo,
-                                EXTCAP_PIPE_PREFIX))
+                                EXTCAP_PIPE_PREFIX, TRUE))
         {
             return FALSE;
         }
@@ -1403,7 +1427,18 @@ extcap_init_interfaces(capture_options *capture_opts)
          */
         if (pid != INVALID_EXTCAP_PID)
         {
-            extcap_wait_for_pipe(interface_opts.extcap_pipe_h, pid);
+            HANDLE pipe_handles[3];
+            int num_pipe_handles = 1;
+            pipe_handles[0] = interface_opts.extcap_pipe_h;
+
+            if (extcap_has_toolbar(interface_opts.name))
+            {
+                pipe_handles[1] = interface_opts.extcap_control_in_h;
+                pipe_handles[2] = interface_opts.extcap_control_out_h;
+                num_pipe_handles += 2;
+             }
+
+            extcap_wait_for_pipe(pipe_handles, num_pipe_handles, pid);
         }
 #endif
 
@@ -1416,15 +1451,14 @@ extcap_init_interfaces(capture_options *capture_opts)
     return TRUE;
 }
 
-gboolean extcap_create_pipe(const gchar *ifname, gchar **fifo, const gchar *pipe_prefix)
+gboolean extcap_create_pipe(const gchar *ifname, gchar **fifo, const gchar *pipe_prefix, gboolean byte_mode _U_)
 {
 #ifdef _WIN32
     gchar timestr[ 14 + 1 ];
     time_t current_time;
-
     gchar *pipename = NULL;
-
     SECURITY_ATTRIBUTES security;
+
     /* create pipename */
     current_time = time(NULL);
     /*
@@ -1440,18 +1474,19 @@ gboolean extcap_create_pipe(const gchar *ifname, gchar **fifo, const gchar *pipe
     security.bInheritHandle = TRUE;
     security.lpSecurityDescriptor = NULL;
 
-    /* create a namedPipe*/
+    /* create a namedPipe */
     pipe_h = CreateNamedPipe(
                  utf_8to16(pipename),
                  PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED,
-                 PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT,
-                 5, 65536, 65536,
+                 byte_mode ? PIPE_TYPE_BYTE : PIPE_TYPE_MESSAGE | byte_mode ? PIPE_READMODE_BYTE : PIPE_READMODE_MESSAGE | PIPE_WAIT,
+                 1, 65536, 65536,
                  300,
                  &security);
 
     if (pipe_h == INVALID_HANDLE_VALUE)
     {
         g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "\nError creating pipe => (%d)", GetLastError());
+        g_free (pipename);
         return FALSE;
     }
     else
diff --git a/extcap.h b/extcap.h
index 2e6739fa00..013ccdb4fd 100644
--- a/extcap.h
+++ b/extcap.h
@@ -40,8 +40,8 @@
 
 /* Prefix for the pipe interfaces */
 #define EXTCAP_PIPE_PREFIX "wireshark_extcap"
-#define EXTCAP_CONTROL_IN_PREFIX  "wireshark_control_in"
-#define EXTCAP_CONTROL_OUT_PREFIX "wireshark_control_out"
+#define EXTCAP_CONTROL_IN_PREFIX  "wireshark_control_ext_to_ws"
+#define EXTCAP_CONTROL_OUT_PREFIX "wireshark_control_ws_to_ext"
 
 #define EXTCAP_ARGUMENT_CONFIG                  "--extcap-config"
 #define EXTCAP_ARGUMENT_LIST_INTERFACES         "--extcap-interfaces"
@@ -143,11 +143,11 @@ gboolean
 extcap_init_interfaces(capture_options * capture_opts);
 
 gboolean
-extcap_create_pipe(const gchar *ifname, gchar **fifo, const gchar *pipe_prefix);
+extcap_create_pipe(const gchar *ifname, gchar **fifo, const gchar *pipe_prefix, gboolean byte_mode);
 
 /* Clean up all if related stuff */
 void
-extcap_if_cleanup(capture_options * capture_opts _U_, gchar ** errormsg);
+extcap_if_cleanup(capture_options * capture_opts, gchar ** errormsg);
 
 struct preference *
 extcap_pref_for_argument(const gchar *ifname, struct _extcap_arg * arg);
diff --git a/extcap_spawn.c b/extcap_spawn.c
index 8b9b5988bf..d88c3945d0 100644
--- a/extcap_spawn.c
+++ b/extcap_spawn.c
@@ -287,67 +287,117 @@ GPid extcap_spawn_async(extcap_userdata *userdata, GPtrArray *args)
 }
 
 #ifdef _WIN32
+
+typedef struct
+{
+    HANDLE pipeHandle;
+    OVERLAPPED ol;
+    BOOL pendingIO;
+} PIPEINTS;
+
 gboolean
-extcap_wait_for_pipe(HANDLE pipe_h, HANDLE pid)
+extcap_wait_for_pipe(HANDLE * pipe_handles, int num_pipe_handles, HANDLE pid)
 {
-    DWORD dw;
-    HANDLE handles[2];
-    OVERLAPPED ov;
-    gboolean success = FALSE;
-    ov.Pointer = 0;
-    ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
-
-    ConnectNamedPipe(pipe_h, &ov);
-    handles[0] = ov.hEvent;
-    handles[1] = pid;
-
-    if (GetLastError() == ERROR_PIPE_CONNECTED)
+    PIPEINTS pipeinsts[3];
+    DWORD dw, cbRet;
+    HANDLE handles[4];
+    int error_code;
+    int num_waiting_to_connect = 0;
+    int num_handles = num_pipe_handles + 1; // PID handle is also added to list of handles.
+
+    if (num_pipe_handles == 0 || num_pipe_handles > 3)
     {
-        g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "extcap connected to pipe");
+        g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "Invalid number of pipes given as argument.");
+        return FALSE;
     }
-    else
+
+    for (int i = 0; i < num_pipe_handles; ++i)
     {
-        dw = WaitForMultipleObjects(2, handles, FALSE, 30000);
-        if (dw == WAIT_OBJECT_0)
+        pipeinsts[i].pipeHandle = pipe_handles[i];
+        pipeinsts[i].ol.Pointer = 0;
+        pipeinsts[i].ol.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
+        pipeinsts[i].pendingIO = FALSE;
+        handles[i] = pipeinsts[i].ol.hEvent;
+        BOOL connected = ConnectNamedPipe(pipeinsts[i].pipeHandle, &pipeinsts[i].ol);
+        if (connected)
+        {
+            error_code = GetLastError();
+            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "ConnectNamedPipe failed with %d \n.", error_code);
+            return FALSE;
+        }
+
+        switch (GetLastError())
         {
-            /* ConnectNamedPipe finished. */
-            DWORD code;
+        case ERROR_IO_PENDING:
+            num_waiting_to_connect++;
+            pipeinsts[i].pendingIO = TRUE;
+            break;
 
-            code = GetLastError();
-            if (code == ERROR_IO_PENDING)
+        case ERROR_PIPE_CONNECTED:
+            if (SetEvent(pipeinsts[i].ol.hEvent))
             {
-                DWORD dummy;
-                if (!GetOverlappedResult(ov.hEvent, &ov, &dummy, TRUE))
-                {
-                    code = GetLastError();
-                }
-                else
-                {
-                    code = ERROR_SUCCESS;
-                    success = TRUE;
-                }
-            }
+                break;
+            } // Fallthrough if this fails.
 
-            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "ConnectNamedPipe code: %d", code);
+        default:
+            error_code = GetLastError();
+            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "ConnectNamedPipe failed with %d \n.", error_code);
+            return FALSE;
         }
-        else if (dw == (WAIT_OBJECT_0 + 1))
+    }
+
+    // Store pid of extcap process so it can be monitored in case it fails before the pipes has connceted.
+    handles[num_pipe_handles] = pid;
+
+    while(num_waiting_to_connect > 0)
+    {
+        dw = WaitForMultipleObjects(num_handles, handles, FALSE, 30000);
+        int idx = dw - WAIT_OBJECT_0;
+        if (dw == WAIT_TIMEOUT)
         {
-            /* extcap process terminated. */
-            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "extcap terminated without connecting to pipe.");
+            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "extcap didn't connect to pipe within 30 seconds.");
+            return FALSE;
         }
-        else if (dw == WAIT_TIMEOUT)
+        // If index points to our handles array
+        else if (idx >= 0 && idx < num_handles)
         {
-            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "extcap didn't connect to pipe within 30 seconds.");
+            if (idx < num_pipe_handles)  // Index of pipe handle
+            {
+                if (pipeinsts[idx].pendingIO)
+                {
+                    BOOL success = GetOverlappedResult(
+                        pipeinsts[idx].pipeHandle, // handle to pipe
+                        &pipeinsts[idx].ol,        // OVERLAPPED structure
+                        &cbRet,                    // bytes transferred
+                        FALSE);                    // do not wait
+
+                    if (!success)
+                    {
+                        g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "Error %d \n.", GetLastError());
+                        return FALSE;
+                    }
+                    else
+                    {
+                        pipeinsts[idx].pendingIO = FALSE;
+                        num_waiting_to_connect--;
+                    }
+                }
+            }
+            else // Index of PID
+            {
+                // Fail since index of 'pid' indicates that the pid of the extcap process has terminated.
+                g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "extcap terminated without connecting to pipe.");
+                return FALSE;
+            }
         }
         else
         {
             g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "WaitForMultipleObjects returned 0x%08X. Error %d", dw, GetLastError());
+            return FALSE;
         }
     }
 
-    CloseHandle(ov.hEvent);
-
-    return success;
+    return TRUE;
 }
 #endif
 
diff --git a/extcap_spawn.h b/extcap_spawn.h
index 16d8a97a58..858671865a 100644
--- a/extcap_spawn.h
+++ b/extcap_spawn.h
@@ -47,7 +47,7 @@ gboolean extcap_spawn_sync ( gchar * dirname, gchar * command, gint argc, gchar
 GPid extcap_spawn_async ( extcap_userdata * userdata, GPtrArray * args );
 
 #ifdef _WIN32
-gboolean extcap_wait_for_pipe(HANDLE pipe_h, HANDLE pid);
+gboolean extcap_wait_for_pipe(HANDLE * pipe_handles, int num_pipe_handles, HANDLE pid);
 void win32_readfrompipe(HANDLE read_pipe, gint32 max_buffer, gchar * buffer);
 #endif
 
diff --git a/ui/qt/interface_toolbar.cpp b/ui/qt/interface_toolbar.cpp
index b28fee9abe..ffddf28f50 100644
--- a/ui/qt/interface_toolbar.cpp
+++ b/ui/qt/interface_toolbar.cpp
@@ -710,7 +710,8 @@ void InterfaceToolbar::closeLog()
     }
 }
 
-void InterfaceToolbar::startReaderThread(QString ifname, QString control_in)
+
+void InterfaceToolbar::startReaderThread(QString ifname, void *control_in)
 {
     QThread *thread = new QThread;
     InterfaceToolbarReader *reader = new InterfaceToolbarReader(ifname, control_in);
@@ -757,12 +758,14 @@ void InterfaceToolbar::startCapture(GArray *ifaces)
             // Already have control channels for this interface
             continue;
 
-        // The reader thread will open control in channel
-        startReaderThread(ifname, interface_opts.extcap_control_in);
-
         // Open control out channel
+#ifdef _WIN32
+        startReaderThread(ifname, interface_opts.extcap_control_in_h);
+        interface_[ifname].out_fd = _open_osfhandle((intptr_t)interface_opts.extcap_control_out_h, O_APPEND | O_BINARY);
+#else
+        startReaderThread(ifname, interface_opts.extcap_control_in);
         interface_[ifname].out_fd = ws_open(interface_opts.extcap_control_out, O_WRONLY | O_BINARY, 0);
-
+#endif
         sendChangedValues(ifname);
         controlSend(ifname, 0, commandControlInitialized);
     }
@@ -800,7 +803,9 @@ void InterfaceToolbar::stopCapture()
 
         if (interface_[ifname].out_fd != -1)
         {
+#ifndef _WIN32
             ws_close (interface_[ifname].out_fd);
+#endif
             interface_[ifname].out_fd = -1;
         }
 
diff --git a/ui/qt/interface_toolbar.h b/ui/qt/interface_toolbar.h
index cdbfb57906..404dc1ccdb 100644
--- a/ui/qt/interface_toolbar.h
+++ b/ui/qt/interface_toolbar.h
@@ -70,7 +70,7 @@ signals:
     void closeReader();
 
 private slots:
-    void startReaderThread(QString ifname, QString control_in);
+    void startReaderThread(QString ifname, void *control_in);
     void updateWidgets();
 
     void onControlButtonPressed();
diff --git a/ui/qt/interface_toolbar_reader.cpp b/ui/qt/interface_toolbar_reader.cpp
index f4565fe6c3..99b15a47b3 100644
--- a/ui/qt/interface_toolbar_reader.cpp
+++ b/ui/qt/interface_toolbar_reader.cpp
@@ -39,37 +39,125 @@
 
 const int header_size = 6;
 
-// To do:
-// - Add support for WIN32
+#ifdef _WIN32
+int InterfaceToolbarReader::async_pipe_read(void *data, int nbyte)
+{
+    BOOL success;
+    DWORD nof_bytes_read, last_err;
+    OVERLAPPED overlap;
+
+    overlap.Pointer = 0;
+    overlap.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
+    if (overlap.hEvent == NULL)
+    {
+        // CreateEvent failed with error code GetLastError()
+        return -1;
+    }
+
+    success = ReadFile(control_in_, data, nbyte, &nof_bytes_read, &overlap);
+
+    if (success && nof_bytes_read != 0)
+    {
+        // The read operation completed successfully.
+        return nof_bytes_read;
+    }
+
+    last_err = GetLastError();
+
+    if (!success && last_err == ERROR_IO_PENDING)
+    {
+        // The operation is still pending, wait for a signal.
+        DWORD wait = WaitForMultipleObjects(1, &overlap.hEvent, TRUE, INFINITE);
+
+        if (wait - WAIT_OBJECT_0 == 0)
+        {
+            // The wait operation has completed.
+            success = GetOverlappedResult(control_in_, &overlap, &nof_bytes_read, FALSE);
+
+            if (success && nof_bytes_read != 0)
+            {
+                // The get result operation completed successfully.
+                return nof_bytes_read;
+            }
+        }
+    }
+
+    // The pipe is closed or an unknown error occured.
+    return -1;
+}
+#endif
+
+int InterfaceToolbarReader::pipe_read(char *data, int nbyte)
+{
+    int total_len = 0;
+
+    while (total_len < nbyte)
+    {
+        char *data_ptr = data + total_len;
+        int data_len = nbyte - total_len;
+
+#ifdef _WIN32
+        int read_len = async_pipe_read(data_ptr, data_len);
+#else
+        int read_len = (int)ws_read(fd_in_, data_ptr, data_len);
+#endif
+        if (read_len == -1)
+        {
+            if (errno != EAGAIN)
+            {
+                return -1;
+            }
+        }
+        else
+        {
+            total_len += read_len;
+        }
+
+#if QT_VERSION >= QT_VERSION_CHECK(5, 2, 0)
+        if (QThread::currentThread()->isInterruptionRequested())
+        {
+            return -1;
+        }
+#endif
+    }
+
+    return total_len;
+}
 
 void InterfaceToolbarReader::loop()
 {
-#ifndef _WIN32
-    struct timeval timeout;
     QByteArray header;
     QByteArray payload;
+
+#ifndef _WIN32
+    struct timeval timeout;
     fd_set readfds;
+    fd_in_ = ws_open(control_in_.toUtf8(), O_RDONLY | O_BINARY | O_NONBLOCK, 0);
 
-    int fd = ws_open(control_in_.toUtf8(), O_RDONLY | O_BINARY | O_NONBLOCK, 0);
-    if (fd == -1)
+    if (fd_in_ == -1)
     {
         emit finished();
         return;
     }
+#endif
+
+    header.resize(header_size);
 
     forever
     {
+#ifndef _WIN32
         FD_ZERO(&readfds);
-        FD_SET(fd, &readfds);
+        FD_SET(fd_in_, &readfds);
 
         timeout.tv_sec = 2;
         timeout.tv_usec = 0;
 
-        int ret = select(fd + 1, &readfds, NULL, NULL, &timeout);
+        int ret = select(fd_in_ + 1, &readfds, NULL, NULL, &timeout);
         if (ret == -1)
         {
             break;
         }
+
 #if QT_VERSION >= QT_VERSION_CHECK(5, 2, 0)
         if (QThread::currentThread()->isInterruptionRequested())
         {
@@ -77,52 +165,40 @@ void InterfaceToolbarReader::loop()
         }
 #endif
 
-        if (ret > 0 && FD_ISSET(fd, &readfds))
+        if (ret == 0 || !FD_ISSET(fd_in_, &readfds))
         {
-            header.resize(header_size);
-            if (ws_read(fd, header.data(), header_size) != header_size)
-            {
-                break;
-            }
+            continue;
+        }
+#endif
 
-            unsigned char high_nibble = header[1] & 0xFF;
-            unsigned char mid_nibble = header[2] & 0xFF;
-            unsigned char low_nibble = header[3] & 0xFF;
-            ssize_t payload_len = (ssize_t)((high_nibble << 16) + (mid_nibble << 8) + low_nibble) - 2;
+        // Read the header from the pipe.
+        if (pipe_read(header.data(), header_size) != header_size)
+        {
+            break;
+        }
 
-            payload.resize((int)payload_len);
-            if (payload_len > 0)
-            {
-                ssize_t total_len = 0;
-                while (total_len < payload_len)
-                {
-                    ssize_t read_len = ws_read(fd, payload.data() + total_len, payload_len - total_len);
-                    if (read_len == -1)
-                    {
-                        if (errno != EAGAIN)
-                        {
-                            break;
-                        }
-                    }
-                    else
-                    {
-                        total_len += read_len;
-                    }
-                }
-                if (total_len != payload_len)
-                {
-                    break;
-                }
-            }
-            if (header[0] == SP_TOOLBAR_CTRL)
-            {
-                emit received(ifname_, (unsigned char)header[4], (unsigned char)header[5], payload);
-            }
+        unsigned char high_nibble = header[1] & 0xFF;
+        unsigned char mid_nibble = header[2] & 0xFF;
+        unsigned char low_nibble = header[3] & 0xFF;
+        int payload_len = (int)((high_nibble << 16) + (mid_nibble << 8) + low_nibble) - 2;
+
+        payload.resize(payload_len);
+        // Read the payload from the pipe.
+        if (pipe_read(payload.data(), payload_len) != payload_len)
+        {
+            break;
+        }
+
+        if (header[0] == SP_TOOLBAR_CTRL)
+        {
+            emit received(ifname_, (unsigned char)header[4], (unsigned char)header[5], payload);
         }
     }
 
-    ws_close(fd);
+#ifndef _WIN32
+    ws_close(fd_in_);
 #endif
+
     emit finished();
 }
 
diff --git a/ui/qt/interface_toolbar_reader.h b/ui/qt/interface_toolbar_reader.h
index 1b34db4fb0..75fc7cbea9 100644
--- a/ui/qt/interface_toolbar_reader.h
+++ b/ui/qt/interface_toolbar_reader.h
@@ -25,6 +25,10 @@
 #include <QObject>
 #include <QByteArray>
 
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
 namespace Ui {
 class InterfaceToolbarReader;
 }
@@ -34,8 +38,16 @@ class InterfaceToolbarReader : public QObject
     Q_OBJECT
 
 public:
-    InterfaceToolbarReader(QString ifname, QString control_in, QObject *parent = 0) :
-    QObject(parent), ifname_(ifname), control_in_(control_in) {}
+    InterfaceToolbarReader(QString ifname, void *control_in, QObject *parent = 0) :
+    QObject(parent), ifname_(ifname)
+    {
+#ifdef _WIN32
+        control_in_ = (HANDLE)control_in;
+#else
+        control_in_ = (char *)control_in;
+        fd_in_ = -1;
+#endif
+    }
 
 public slots:
     void loop();
@@ -45,8 +57,18 @@ signals:
     void finished();
 
 private:
+#ifdef _WIN32
+    int async_pipe_read(void *data, int nbyte);
+#endif
+    int pipe_read(char *data, int nbyte);
+
     QString ifname_;
+#ifdef _WIN32
+    HANDLE control_in_;
+#else
     QString control_in_;
+    int fd_in_;
+#endif
 };
 
 #endif // INTERFACE_TOOLBAR_READER_H
diff --git a/ui/qt/main_window.cpp b/ui/qt/main_window.cpp
index 653ff4cf4f..cd5a2ca53e 100644
--- a/ui/qt/main_window.cpp
+++ b/ui/qt/main_window.cpp
@@ -714,14 +714,12 @@ MainWindow::MainWindow(QWidget *parent) :
 #endif
     plugin_if_register_gui_cb(PLUGIN_IF_REMOVE_TOOLBAR, plugin_if_mainwindow_update_toolbars);
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 2, 0) && !defined(_WIN32)
+#if QT_VERSION >= QT_VERSION_CHECK(5, 2, 0)
     // Register Interface Toolbar callbacks
     //
     // Qt version must be 5.2 or higher because the use of
     // QThread::requestInterruption() in interface_toolbar.cpp and
     // QThread::isInterruptionRequested() in interface_toolbar_reader.cpp
-    //
-    // The toolbar in/out control pipes are not supported on WIN32 yet.
     iface_toolbar_register_cb(mainwindow_add_toolbar, mainwindow_remove_toolbar);
 #endif
 
diff --git a/ui/qt/main_window_slots.cpp b/ui/qt/main_window_slots.cpp
index 0c6dcbf710..c6d30c9a6a 100644
--- a/ui/qt/main_window_slots.cpp
+++ b/ui/qt/main_window_slots.cpp
@@ -657,7 +657,7 @@ void MainWindow::queuedFilterAction(QString action_filter, FilterAction::Action
 
 // Capture callbacks
 
-void MainWindow::captureCapturePrepared(capture_session *session) {
+void MainWindow::captureCapturePrepared(capture_session *) {
 #ifdef HAVE_LIBPCAP
     setTitlebarForCaptureInProgress();
 
@@ -665,7 +665,7 @@ void MainWindow::captureCapturePrepared(capture_session *session) {
 
     /* Disable menu items that make no sense if you're currently running
        a capture. */
-    setForCaptureInProgress(true, session->capture_opts->ifaces);
+    setForCaptureInProgress(true);
 //    set_capture_if_dialog_for_capture_in_progress(TRUE);
 
 //    /* Don't set up main window for a capture file. */