Update file structure

gns3server/modules/vpcs/__init__.py

@@ -0,0 +1,690 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2014 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+VPCS server module.
+"""
+
+import os
+import sys
+import base64
+import tempfile
+import fcntl
+import struct
+import socket
+import shutil
+
+from gns3server.modules import IModule
+from gns3server.config import Config
+import gns3server.jsonrpc as jsonrpc
+from .vpcs_device import VPCSDevice
+from .vpcs_error import VPCSError
+from .nios.nio_udp import NIO_UDP
+from .nios.nio_tap import NIO_TAP
+from ..attic import find_unused_port
+
+from .schemas import VPCS_CREATE_SCHEMA
+from .schemas import VPCS_DELETE_SCHEMA
+from .schemas import VPCS_UPDATE_SCHEMA
+from .schemas import VPCS_START_SCHEMA
+from .schemas import VPCS_STOP_SCHEMA
+from .schemas import VPCS_RELOAD_SCHEMA
+from .schemas import VPCS_ALLOCATE_UDP_PORT_SCHEMA
+from .schemas import VPCS_ADD_NIO_SCHEMA
+from .schemas import VPCS_DELETE_NIO_SCHEMA
+
+import logging
+log = logging.getLogger(__name__)
+
+
+class VPCS(IModule):
+    """
+    VPCS module.
+
+    :param name: module name
+    :param args: arguments for the module
+    :param kwargs: named arguments for the module
+    """
+
+    def __init__(self, name, *args, **kwargs):
+
+        # get the VPCS location
+        config = Config.instance()
+        VPCS_config = config.get_section_config(name.upper())
+        self._VPCS = VPCS_config.get("VPCS")
+        if not self._VPCS or not os.path.isfile(self._VPCS):
+            VPCS_in_cwd = os.path.join(os.getcwd(), "VPCS")
+            if os.path.isfile(VPCS_in_cwd):
+                self._VPCS = VPCS_in_cwd
+            else:
+                # look for VPCS if none is defined or accessible
+                for path in os.environ["PATH"].split(":"):
+                    try:
+                        if "VPCS" in os.listdir(path) and os.access(os.path.join(path, "VPCS"), os.X_OK):
+                            self._VPCS = os.path.join(path, "VPCS")
+                            break
+                    except OSError:
+                        continue
+
+        if not self._VPCS:
+            log.warning("VPCS binary couldn't be found!")
+        elif not os.access(self._VPCS, os.X_OK):
+            log.warning("VPCS is not executable")
+
+        # a new process start when calling IModule
+        IModule.__init__(self, name, *args, **kwargs)
+        self._VPCS_instances = {}
+        self._console_start_port_range = 4001
+        self._console_end_port_range = 4512
+        self._allocated_console_ports = []
+        self._current_console_port = self._console_start_port_range
+        self._udp_start_port_range = 30001
+        self._udp_end_port_range = 40001
+        self._current_udp_port = self._udp_start_port_range
+        self._host = kwargs["host"]
+        self._projects_dir = kwargs["projects_dir"]
+        self._tempdir = kwargs["temp_dir"]
+        self._working_dir = self._projects_dir
+        self._VPCSrc = ""
+
+        # check every 5 seconds
+        self._VPCS_callback = self.add_periodic_callback(self._check_VPCS_is_alive, 5000)
+        self._VPCS_callback.start()
+
+    def stop(self, signum=None):
+        """
+        Properly stops the module.
+
+        :param signum: signal number (if called by the signal handler)
+        """
+
+        self._VPCS_callback.stop()
+        # delete all VPCS instances
+        for VPCS_id in self._VPCS_instances:
+            VPCS_instance = self._VPCS_instances[VPCS_id]
+            VPCS_instance.delete()
+
+        IModule.stop(self, signum)  # this will stop the I/O loop
+
+    def _check_VPCS_is_alive(self):
+        """
+        Periodic callback to check if VPCS and VPCS are alive
+        for each VPCS instance.
+
+        Sends a notification to the client if not.
+        """
+
+        for VPCS_id in self._VPCS_instances:
+            VPCS_instance = self._VPCS_instances[VPCS_id]
+            if VPCS_instance.started and (not VPCS_instance.is_running() or not VPCS_instance.is_VPCS_running()):
+                notification = {"module": self.name,
+                                "id": VPCS_id,
+                                "name": VPCS_instance.name}
+                if not VPCS_instance.is_running():
+                    stdout = VPCS_instance.read_VPCS_stdout()
+                    notification["message"] = "VPCS has stopped running"
+                    notification["details"] = stdout
+                    self.send_notification("{}.VPCS_stopped".format(self.name), notification)
+                elif not VPCS_instance.is_VPCS_running():
+                    stdout = VPCS_instance.read_VPCS_stdout()
+                    notification["message"] = "VPCS has stopped running"
+                    notification["details"] = stdout
+                    self.send_notification("{}.VPCS_stopped".format(self.name), notification)
+                VPCS_instance.stop()
+
+    def get_VPCS_instance(self, VPCS_id):
+        """
+        Returns an VPCS device instance.
+
+        :param VPCS_id: VPCS device identifier
+
+        :returns: VPCSDevice instance
+        """
+
+        if VPCS_id not in self._VPCS_instances:
+            log.debug("VPCS device ID {} doesn't exist".format(VPCS_id), exc_info=1)
+            self.send_custom_error("VPCS device ID {} doesn't exist".format(VPCS_id))
+            return None
+        return self._VPCS_instances[VPCS_id]
+
+    @IModule.route("VPCS.reset")
+    def reset(self, request):
+        """
+        Resets the module.
+
+        :param request: JSON request
+        """
+
+        # delete all VPCS instances
+        for VPCS_id in self._VPCS_instances:
+            VPCS_instance = self._VPCS_instances[VPCS_id]
+            VPCS_instance.delete()
+
+        # resets the instance IDs
+        VPCSDevice.reset()
+
+        self._VPCS_instances.clear()
+        self._remote_server = False
+        self._current_console_port = self._console_start_port_range
+        self._current_udp_port = self._udp_start_port_range
+
+        if self._VPCSrc and os.path.isfile(self._VPCSrc):
+            try:
+                log.info("deleting VPCSrc file {}".format(self._VPCSrc))
+                os.remove(self._VPCSrc)
+            except OSError as e:
+                log.warn("could not delete VPCSrc file {}: {}".format(self._VPCSrc, e))
+
+        log.info("VPCS module has been reset")
+
+    @IModule.route("VPCS.settings")
+    def settings(self, request):
+        """
+        Set or update settings.
+
+        Optional request parameters:
+        - working_dir (path to a working directory)
+        - project_name
+        - console_start_port_range
+        - console_end_port_range
+        - udp_start_port_range
+        - udp_end_port_range
+
+        :param request: JSON request
+        """
+
+        if request == None:
+            self.send_param_error()
+            return
+
+        if "VPCS" in request and request["VPCS"]:
+            self._VPCS = request["VPCS"]
+            log.info("VPCS path set to {}".format(self._VPCS))
+
+        if "working_dir" in request:
+            new_working_dir = request["working_dir"]
+            log.info("this server is local with working directory path to {}".format(new_working_dir))
+        else:
+            new_working_dir = os.path.join(self._projects_dir, request["project_name"] + ".gns3")
+            log.info("this server is remote with working directory path to {}".format(new_working_dir))
+            if self._projects_dir != self._working_dir != new_working_dir:
+                if not os.path.isdir(new_working_dir):
+                    try:
+                        shutil.move(self._working_dir, new_working_dir)
+                    except OSError as e:
+                        log.error("could not move working directory from {} to {}: {}".format(self._working_dir,
+                                                                                              new_working_dir,
+                                                                                              e))
+                        return
+
+        # update the working directory if it has changed
+        if self._working_dir != new_working_dir:
+            self._working_dir = new_working_dir
+            for VPCS_id in self._VPCS_instances:
+                VPCS_instance = self._VPCS_instances[VPCS_id]
+                VPCS_instance.working_dir = self._working_dir
+
+        if "console_start_port_range" in request and "console_end_port_range" in request:
+            self._console_start_port_range = request["console_start_port_range"]
+            self._console_end_port_range = request["console_end_port_range"]
+
+        if "udp_start_port_range" in request and "udp_end_port_range" in request:
+            self._udp_start_port_range = request["udp_start_port_range"]
+            self._udp_end_port_range = request["udp_end_port_range"]
+
+        log.debug("received request {}".format(request))
+
+    def test_result(self, message, result="error"):
+        """
+        """
+
+        return {"result": result, "message": message}
+
+    @IModule.route("VPCS.test_settings")
+    def test_settings(self, request):
+        """
+        """
+
+        response = []
+
+        self.send_response(response)
+
+    @IModule.route("VPCS.create")
+    def VPCS_create(self, request):
+        """
+        Creates a new VPCS instance.
+
+        Mandatory request parameters:
+        - path (path to the VPCS executable)
+
+        Optional request parameters:
+        - name (VPCS name)
+
+        Response parameters:
+        - id (VPCS instance identifier)
+        - name (VPCS name)
+        - default settings
+
+        :param request: JSON request
+        """
+
+        # validate the request
+        if not self.validate_request(request, VPCS_CREATE_SCHEMA):
+            return
+
+        name = None
+        if "name" in request:
+            name = request["name"]
+        VPCS_path = request["path"]
+
+        try:
+            try:
+                os.makedirs(self._working_dir)
+            except FileExistsError:
+                pass
+            except OSError as e:
+                raise VPCSError("Could not create working directory {}".format(e))
+
+            VPCS_instance = VPCSDevice(VPCS_path, self._working_dir, host=self._host, name=name)
+            # find a console port
+            if self._current_console_port > self._console_end_port_range:
+                self._current_console_port = self._console_start_port_range
+            try:
+                VPCS_instance.console = find_unused_port(self._current_console_port, self._console_end_port_range, self._host)
+            except Exception as e:
+                raise VPCSError(e)
+            self._current_console_port += 1
+        except VPCSError as e:
+            self.send_custom_error(str(e))
+            return
+
+        response = {"name": VPCS_instance.name,
+                    "id": VPCS_instance.id}
+
+        defaults = VPCS_instance.defaults()
+        response.update(defaults)
+        self._VPCS_instances[VPCS_instance.id] = VPCS_instance
+        self.send_response(response)
+
+    @IModule.route("VPCS.delete")
+    def VPCS_delete(self, request):
+        """
+        Deletes an VPCS instance.
+
+        Mandatory request parameters:
+        - id (VPCS instance identifier)
+
+        Response parameter:
+        - True on success
+
+        :param request: JSON request
+        """
+
+        # validate the request
+        if not self.validate_request(request, VPCS_DELETE_SCHEMA):
+            return
+
+        # get the instance
+        VPCS_instance = self.get_VPCS_instance(request["id"])
+        if not VPCS_instance:
+            return
+
+        try:
+            VPCS_instance.delete()
+            del self._VPCS_instances[request["id"]]
+        except VPCSError as e:
+            self.send_custom_error(str(e))
+            return
+
+        self.send_response(True)
+
+    @IModule.route("VPCS.update")
+    def VPCS_update(self, request):
+        """
+        Updates an VPCS instance
+
+        Mandatory request parameters:
+        - id (VPCS instance identifier)
+
+        Optional request parameters:
+        - any setting to update
+        - startup_config_base64 (startup-config base64 encoded)
+
+        Response parameters:
+        - updated settings
+
+        :param request: JSON request
+        """
+
+        # validate the request
+        if not self.validate_request(request, VPCS_UPDATE_SCHEMA):
+            return
+
+        # get the instance
+        VPCS_instance = self.get_VPCS_instance(request["id"])
+        if not VPCS_instance:
+            return
+
+        response = {}
+        try:
+            # a new startup-config has been pushed
+            if "startup_config_base64" in request:
+                config = base64.decodestring(request["startup_config_base64"].encode("utf-8")).decode("utf-8")
+                config = "!\n" + config.replace("\r", "")
+                config = config.replace('%h', VPCS_instance.name)
+                config_path = os.path.join(VPCS_instance.working_dir, "startup-config")
+                try:
+                    with open(config_path, "w") as f:
+                        log.info("saving startup-config to {}".format(config_path))
+                        f.write(config)
+                except OSError as e:
+                    raise VPCSError("Could not save the configuration {}: {}".format(config_path, e))
+                # update the request with the new local startup-config path
+                request["startup_config"] = os.path.basename(config_path)
+
+        except VPCSError as e:
+            self.send_custom_error(str(e))
+            return
+
+        # update the VPCS settings
+        for name, value in request.items():
+            if hasattr(VPCS_instance, name) and getattr(VPCS_instance, name) != value:
+                try:
+                    setattr(VPCS_instance, name, value)
+                    response[name] = value
+                except VPCSError as e:
+                    self.send_custom_error(str(e))
+                    return
+
+        self.send_response(response)
+
+    @IModule.route("VPCS.start")
+    def vm_start(self, request):
+        """
+        Starts an VPCS instance.
+
+        Mandatory request parameters:
+        - id (VPCS instance identifier)
+
+        Response parameters:
+        - True on success
+
+        :param request: JSON request
+        """
+
+        # validate the request
+        if not self.validate_request(request, VPCS_START_SCHEMA):
+            return
+
+        # get the instance
+        VPCS_instance = self.get_VPCS_instance(request["id"])
+        if not VPCS_instance:
+            return
+
+        try:
+            log.debug("starting VPCS with command: {}".format(VPCS_instance.command()))
+            VPCS_instance.VPCS = self._VPCS
+            VPCS_instance.VPCSrc = self._VPCSrc
+            VPCS_instance.start()
+        except VPCSError as e:
+            self.send_custom_error(str(e))
+            return
+        self.send_response(True)
+
+    @IModule.route("VPCS.stop")
+    def vm_stop(self, request):
+        """
+        Stops an VPCS instance.
+
+        Mandatory request parameters:
+        - id (VPCS instance identifier)
+
+        Response parameters:
+        - True on success
+
+        :param request: JSON request
+        """
+
+        # validate the request
+        if not self.validate_request(request, VPCS_STOP_SCHEMA):
+            return
+
+        # get the instance
+        VPCS_instance = self.get_VPCS_instance(request["id"])
+        if not VPCS_instance:
+            return
+
+        try:
+            VPCS_instance.stop()
+        except VPCSError as e:
+            self.send_custom_error(str(e))
+            return
+        self.send_response(True)
+
+    @IModule.route("VPCS.reload")
+    def vm_reload(self, request):
+        """
+        Reloads an VPCS instance.
+
+        Mandatory request parameters:
+        - id (VPCS identifier)
+
+        Response parameters:
+        - True on success
+
+        :param request: JSON request
+        """
+
+        # validate the request
+        if not self.validate_request(request, VPCS_RELOAD_SCHEMA):
+            return
+
+        # get the instance
+        VPCS_instance = self.get_VPCS_instance(request["id"])
+        if not VPCS_instance:
+            return
+
+        try:
+            if VPCS_instance.is_running():
+                VPCS_instance.stop()
+            VPCS_instance.start()
+        except VPCSError as e:
+            self.send_custom_error(str(e))
+            return
+        self.send_response(True)
+
+    @IModule.route("VPCS.allocate_udp_port")
+    def allocate_udp_port(self, request):
+        """
+        Allocates a UDP port in order to create an UDP NIO.
+
+        Mandatory request parameters:
+        - id (VPCS identifier)
+        - port_id (unique port identifier)
+
+        Response parameters:
+        - port_id (unique port identifier)
+        - lport (allocated local port)
+
+        :param request: JSON request
+        """
+
+        # validate the request
+        if not self.validate_request(request, VPCS_ALLOCATE_UDP_PORT_SCHEMA):
+            return
+
+        # get the instance
+        VPCS_instance = self.get_VPCS_instance(request["id"])
+        if not VPCS_instance:
+            return
+
+        try:
+
+            # find a UDP port
+            if self._current_udp_port >= self._udp_end_port_range:
+                self._current_udp_port = self._udp_start_port_range
+            try:
+                port = find_unused_port(self._current_udp_port, self._udp_end_port_range, host=self._host, socket_type="UDP")
+            except Exception as e:
+                raise VPCSError(e)
+            self._current_udp_port += 1
+
+            log.info("{} [id={}] has allocated UDP port {} with host {}".format(VPCS_instance.name,
+                                                                                VPCS_instance.id,
+                                                                                port,
+                                                                                self._host))
+            response = {"lport": port}
+
+        except VPCSError as e:
+            self.send_custom_error(str(e))
+            return
+
+        response["port_id"] = request["port_id"]
+        self.send_response(response)
+
+    def _check_for_privileged_access(self, device):
+        """
+        Check if VPCS can access Ethernet and TAP devices.
+
+        :param device: device name
+        """
+
+        # we are root, so VPCS should have privileged access too
+        if os.geteuid() == 0:
+            return
+
+        # test if VPCS has the CAP_NET_RAW capability
+        if "security.capability" in os.listxattr(self._VPCS):
+            try:
+                caps = os.getxattr(self._VPCS, "security.capability")
+                # test the 2nd byte and check if the 13th bit (CAP_NET_RAW) is set
+                if struct.unpack("<IIIII", caps)[1] & 1 << 13:
+                    return
+            except Exception as e:
+                log.error("could not determine if CAP_NET_RAW capability is set for {}: {}".format(self._VPCS, e))
+                return
+
+        raise VPCSError("{} has no privileged access to {}.".format(self._VPCS, device))
+
+    @IModule.route("VPCS.add_nio")
+    def add_nio(self, request):
+        """
+        Adds an NIO (Network Input/Output) for an VPCS instance.
+
+        Mandatory request parameters:
+        - id (VPCS instance identifier)
+        - slot (slot number)
+        - port (port number)
+        - port_id (unique port identifier)
+        - nio (one of the following)
+            - type "nio_udp"
+                - lport (local port)
+                - rhost (remote host)
+                - rport (remote port)
+            - type "nio_tap"
+                - tap_device (TAP device name e.g. tap0)
+
+        Response parameters:
+        - port_id (unique port identifier)
+
+        :param request: JSON request
+        """
+
+        # validate the request
+        if not self.validate_request(request, VPCS_ADD_NIO_SCHEMA):
+            return
+
+        # get the instance
+        VPCS_instance = self.get_VPCS_instance(request["id"])
+        if not VPCS_instance:
+            return
+
+        slot = request["slot"]
+        port = request["port"]
+        try:
+            nio = None
+            if request["nio"]["type"] == "nio_udp":
+                lport = request["nio"]["lport"]
+                rhost = request["nio"]["rhost"]
+                rport = request["nio"]["rport"]
+                nio = NIO_UDP(lport, rhost, rport)
+            elif request["nio"]["type"] == "nio_tap":
+                tap_device = request["nio"]["tap_device"]
+                self._check_for_privileged_access(tap_device)
+                nio = NIO_TAP(tap_device)
+            if not nio:
+                raise VPCSError("Requested NIO does not exist or is not supported: {}".format(request["nio"]["type"]))
+        except VPCSError as e:
+            self.send_custom_error(str(e))
+            return
+
+        try:
+            VPCS_instance.slot_add_nio_binding(slot, port, nio)
+        except VPCSError as e:
+            self.send_custom_error(str(e))
+            return
+
+        self.send_response({"port_id": request["port_id"]})
+
+    @IModule.route("VPCS.delete_nio")
+    def delete_nio(self, request):
+        """
+        Deletes an NIO (Network Input/Output).
+
+        Mandatory request parameters:
+        - id (VPCS instance identifier)
+        - slot (slot identifier)
+        - port (port identifier)
+
+        Response parameters:
+        - True on success
+
+        :param request: JSON request
+        """
+
+        # validate the request
+        if not self.validate_request(request, VPCS_DELETE_NIO_SCHEMA):
+            return
+
+        # get the instance
+        VPCS_instance = self.get_VPCS_instance(request["id"])
+        if not VPCS_instance:
+            return
+
+        slot = request["slot"]
+        port = request["port"]
+        try:
+            VPCS_instance.slot_remove_nio_binding(slot, port)
+        except VPCSError as e:
+            self.send_custom_error(str(e))
+            return
+
+        self.send_response(True)
+
+    @IModule.route("VPCS.echo")
+    def echo(self, request):
+        """
+        Echo end point for testing purposes.
+
+        :param request: JSON request
+        """
+
+        if request == None:
+            self.send_param_error()
+        else:
+            log.debug("received request {}".format(request))
+            self.send_response(request)

gns3server/modules/vpcs/__init__.py~

@@ -196,9 +196,6 @@ class VPCS(IModule):
         """
         Set or update settings.
 
-        Mandatory request parameters:
-        - VPCSrc (base64 encoded VPCSrc file)
-
         Optional request parameters:
         - working_dir (path to a working directory)
         - project_name

gns3server/modules/vpcs/nios/nio_tap.py

@@ -0,0 +1,46 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2013 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Interface for TAP NIOs (UNIX based OSes only).
+"""
+
+
+class NIO_TAP(object):
+    """
+    IOU TAP NIO.
+
+    :param tap_device: TAP device name (e.g. tap0)
+    """
+
+    def __init__(self, tap_device):
+
+        self._tap_device = tap_device
+
+    @property
+    def tap_device(self):
+        """
+        Returns the TAP device used by this NIO.
+
+        :returns: the TAP device name
+        """
+
+        return self._tap_device
+
+    def __str__(self):
+
+        return "NIO TAP"

gns3server/modules/vpcs/nios/nio_tap.py~~

@@ -0,0 +1,46 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2013 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Interface for TAP NIOs (UNIX based OSes only).
+"""
+
+
+class NIO_TAP(object):
+    """
+    IOU TAP NIO.
+
+    :param tap_device: TAP device name (e.g. tap0)
+    """
+
+    def __init__(self, tap_device):
+
+        self._tap_device = tap_device
+
+    @property
+    def tap_device(self):
+        """
+        Returns the TAP device used by this NIO.
+
+        :returns: the TAP device name
+        """
+
+        return self._tap_device
+
+    def __str__(self):
+
+        return "NIO TAP"

gns3server/modules/vpcs/nios/nio_udp.py

@@ -0,0 +1,72 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2013 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Interface for UDP NIOs.
+"""
+
+
+class NIO_UDP(object):
+    """
+    IOU UDP NIO.
+
+    :param lport: local port number
+    :param rhost: remote address/host
+    :param rport: remote port number
+    """
+
+    _instance_count = 0
+
+    def __init__(self, lport, rhost, rport):
+
+        self._lport = lport
+        self._rhost = rhost
+        self._rport = rport
+
+    @property
+    def lport(self):
+        """
+        Returns the local port
+
+        :returns: local port number
+        """
+
+        return self._lport
+
+    @property
+    def rhost(self):
+        """
+        Returns the remote host
+
+        :returns: remote address/host
+        """
+
+        return self._rhost
+
+    @property
+    def rport(self):
+        """
+        Returns the remote port
+
+        :returns: remote port number
+        """
+
+        return self._rport
+
+    def __str__(self):
+
+        return "NIO UDP"

gns3server/modules/vpcs/schemas.py

@@ -0,0 +1,306 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2014 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+VPCS_CREATE_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "description": "Request validation to create a new VPCS instance",
+    "type": "object",
+    "properties": {
+        "name": {
+            "description": "VPCS device name",
+            "type": "string",
+            "minLength": 1,
+        },
+        "path": {
+            "description": "path to the VPCS executable",
+            "type": "string",
+            "minLength": 1,
+        }
+    },
+    "required": ["path"]
+}
+
+VPCS_DELETE_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "description": "Request validation to delete an VPCS instance",
+    "type": "object",
+    "properties": {
+        "id": {
+            "description": "VPCS device instance ID",
+            "type": "integer"
+        },
+    },
+    "required": ["id"]
+}
+
+VPCS_UPDATE_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "description": "Request validation to update an VPCS instance",
+    "type": "object",
+    "properties": {
+        "id": {
+            "description": "VPCS device instance ID",
+            "type": "integer"
+        },
+        "name": {
+            "description": "VPCS device name",
+            "type": "string",
+            "minLength": 1,
+        },
+        "path": {
+            "description": "path to the VPCS executable",
+            "type": "string",
+            "minLength": 1,
+        },
+        "script_file": {
+            "description": "path to the VPCS startup configuration file",
+            "type": "string",
+            "minLength": 1,
+        },
+        "script_file_base64": {
+            "description": "startup configuration base64 encoded",
+            "type": "string"
+        },
+    },
+    "required": ["id"]
+}
+
+VPCS_START_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "description": "Request validation to start an VPCS instance",
+    "type": "object",
+    "properties": {
+        "id": {
+            "description": "VPCS device instance ID",
+            "type": "integer"
+        },
+    },
+    "required": ["id"]
+}
+
+VPCS_STOP_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "description": "Request validation to stop an VPCS instance",
+    "type": "object",
+    "properties": {
+        "id": {
+            "description": "VPCS device instance ID",
+            "type": "integer"
+        },
+    },
+    "required": ["id"]
+}
+
+VPCS_RELOAD_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "description": "Request validation to reload an VPCS instance",
+    "type": "object",
+    "properties": {
+        "id": {
+            "description": "VPCS device instance ID",
+            "type": "integer"
+        },
+    },
+    "required": ["id"]
+}
+
+VPCS_ALLOCATE_UDP_PORT_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "description": "Request validation to allocate an UDP port for an VPCS instance",
+    "type": "object",
+    "properties": {
+        "id": {
+            "description": "VPCS device instance ID",
+            "type": "integer"
+        },
+        "port_id": {
+            "description": "Unique port identifier for the VPCS instance",
+            "type": "integer"
+        },
+    },
+    "required": ["id", "port_id"]
+}
+
+VPCS_ADD_NIO_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "description": "Request validation to add a NIO for an VPCS instance",
+    "type": "object",
+
+    "definitions": {
+            "UDP": {
+                "description": "UDP Network Input/Output",
+                "properties": {
+                        "type": {
+                             "enum": ["nio_udp"]
+                        },
+                        "lport": {
+                              "description": "Local port",
+                              "type": "integer",
+                              "minimum": 1,
+                              "maximum": 65535
+                        },
+                        "rhost": {
+                              "description": "Remote host",
+                              "type": "string",
+                              "minLength": 1
+                        },
+                        "rport": {
+                              "description": "Remote port",
+                              "type": "integer",
+                              "minimum": 1,
+                              "maximum": 65535
+                        }
+                    },
+                "required": ["type", "lport", "rhost", "rport"],
+                "additionalProperties": False
+            },
+            "Ethernet": {
+                "description": "Generic Ethernet Network Input/Output",
+                "properties": {
+                        "type": {
+                              "enum": ["nio_generic_ethernet"]
+                        },
+                        "ethernet_device": {
+                              "description": "Ethernet device name e.g. eth0",
+                              "type": "string",
+                              "minLength": 1
+                        },
+                    },
+                "required": ["type", "ethernet_device"],
+                "additionalProperties": False
+            },
+            "LinuxEthernet": {
+                "description": "Linux Ethernet Network Input/Output",
+                "properties": {
+                        "type": {
+                              "enum": ["nio_linux_ethernet"]
+                        },
+                        "ethernet_device": {
+                              "description": "Ethernet device name e.g. eth0",
+                              "type": "string",
+                              "minLength": 1
+                        },
+                    },
+                "required": ["type", "ethernet_device"],
+                "additionalProperties": False
+            },
+            "TAP": {
+                "description": "TAP Network Input/Output",
+                "properties": {
+                        "type": {
+                            "enum": ["nio_tap"]
+                        },
+                        "tap_device": {
+                              "description": "TAP device name e.g. tap0",
+                              "type": "string",
+                              "minLength": 1
+                        },
+                    },
+                "required": ["type", "tap_device"],
+                "additionalProperties": False
+            },
+            "UNIX": {
+                "description": "UNIX Network Input/Output",
+                "properties": {
+                        "type": {
+                            "enum": ["nio_unix"]
+                        },
+                        "local_file": {
+                              "description": "path to the UNIX socket file (local)",
+                              "type": "string",
+                              "minLength": 1
+                        },
+                        "remote_file": {
+                              "description": "path to the UNIX socket file (remote)",
+                              "type": "string",
+                              "minLength": 1
+                        },
+                    },
+                "required": ["type", "local_file", "remote_file"],
+                "additionalProperties": False
+            },
+            "VDE": {
+                "description": "VDE Network Input/Output",
+                "properties": {
+                        "type": {
+                            "enum": ["nio_vde"]
+                        },
+                        "control_file": {
+                              "description": "path to the VDE control file",
+                              "type": "string",
+                              "minLength": 1
+                        },
+                        "local_file": {
+                              "description": "path to the VDE control file",
+                              "type": "string",
+                              "minLength": 1
+                        },
+                    },
+                "required": ["type", "control_file", "local_file"],
+                "additionalProperties": False
+            },
+            "NULL": {
+                "description": "NULL Network Input/Output",
+                "properties": {
+                        "type": {
+                            "enum": ["nio_null"]
+                        },
+                    },
+                "required": ["type"],
+                "additionalProperties": False
+            },
+        },
+
+    "properties": {
+        "id": {
+            "description": "VPCS device instance ID",
+            "type": "integer"
+        },
+        "port_id": {
+            "description": "Unique port identifier for the VPCS instance",
+            "type": "integer"
+        },
+        "nio": {
+            "type": "object",
+            "description": "Network Input/Output",
+            "oneOf": [
+                {"$ref": "#/definitions/UDP"},
+                {"$ref": "#/definitions/Ethernet"},
+                {"$ref": "#/definitions/LinuxEthernet"},
+                {"$ref": "#/definitions/TAP"},
+                {"$ref": "#/definitions/UNIX"},
+                {"$ref": "#/definitions/VDE"},
+                {"$ref": "#/definitions/NULL"},
+            ]
+        },
+    },
+    "required": ["id", "port_id", "nio"]
+}
+
+VPCS_DELETE_NIO_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "description": "Request validation to delete a NIO for an VPCS instance",
+    "type": "object",
+    "properties": {
+        "id": {
+            "description": "VPCS device instance ID",
+            "type": "integer"
+        },
+    },
+    "required": ["id"]
+}

gns3server/modules/vpcs/vpcs_device.py

@@ -0,0 +1,471 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2014 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+VPCS device management (creates command line, processes, files etc.) in
+order to run an VPCS instance.
+"""
+
+import os
+import re
+import signal
+import subprocess
+import argparse
+import threading
+import configparser
+from .vpcscon import start_vpcscon
+from .vpcs_error import VPCSError
+from .nios.nio_udp import NIO_UDP
+from .nios.nio_tap import NIO_TAP
+
+import logging
+log = logging.getLogger(__name__)
+
+
+class VPCSDevice(object):
+    """
+    VPCS device implementation.
+
+    :param path: path to VPCS executable
+    :param working_dir: path to a working directory
+    :param host: host/address to bind for console and UDP connections
+    :param name: name of this VPCS device
+    """
+
+    _instances = []
+
+    def __init__(self, path, working_dir, host="127.0.0.1", name=None):
+
+        # find an instance identifier (0 <= id < 255)
+        # This 255 limit is due to a restriction on the number of possible
+        # mac addresses given in VPCS using the -m option
+        self._id = 0
+        for identifier in range(0, 255):
+            if identifier not in self._instances:
+                self._id = identifier
+                self._instances.append(self._id)
+                break
+
+        if self._id == 0:
+            raise VPCSError("Maximum number of VPCS instances reached")
+
+        if name:
+            self._name = name
+        else:
+            self._name = "VPCS{}".format(self._id)
+        self._path = path
+        self._console = None
+        self._working_dir = None
+        self._command = []
+        self._process = None
+        self._vpcs_stdout_file = ""
+        self._vpcscon_thead = None
+        self._vpcscon_thread_stop_event = None
+        self._host = host
+        self._started = False
+
+        # VPCS settings
+        self._script_file = ""
+        
+        # update the working directory
+        self.working_dir = working_dir
+
+        log.info("VPCS device {name} [id={id}] has been created".format(name=self._name,
+                                                                       id=self._id))
+
+    def defaults(self):
+        """
+        Returns all the default attribute values for VPCS.
+
+        :returns: default values (dictionary)
+        """
+
+        vpcs_defaults = {"name": self._name,
+                        "path": self._path,
+                        "script_file": self._script_file,
+                        "console": self._console}
+
+        return vpcs_defaults
+
+    @property
+    def id(self):
+        """
+        Returns the unique ID for this VPCS device.
+
+        :returns: id (integer)
+        """
+
+        return(self._id)
+
+    @classmethod
+    def reset(cls):
+        """
+        Resets allocated instance list.
+        """
+
+        cls._instances.clear()
+
+    @property
+    def name(self):
+        """
+        Returns the name of this VPCS device.
+
+        :returns: name
+        """
+
+        return self._name
+
+    @name.setter
+    def name(self, new_name):
+        """
+        Sets the name of this VPCS device.
+
+        :param new_name: name
+        """
+
+        self._name = new_name
+        log.info("VPCS {name} [id={id}]: renamed to {new_name}".format(name=self._name,
+                                                                      id=self._id,
+                                                                      new_name=new_name))
+
+    @property
+    def path(self):
+        """
+        Returns the path to the VPCS executable.
+
+        :returns: path to VPCS
+        """
+
+        return(self._path)
+
+    @path.setter
+    def path(self, path):
+        """
+        Sets the path to the VPCS executable.
+
+        :param path: path to VPCS
+        """
+
+        self._path = path
+        log.info("VPCS {name} [id={id}]: path changed to {path}".format(name=self._name,
+                                                                      id=self._id,
+                                                                      path=path))
+
+    @property
+    def working_dir(self):
+        """
+        Returns current working directory
+
+        :returns: path to the working directory
+        """
+
+        return self._working_dir
+
+    @working_dir.setter
+    def working_dir(self, working_dir):
+        """
+        Sets the working directory for VPCS.
+
+        :param working_dir: path to the working directory
+        """
+
+        # create our own working directory
+        working_dir = os.path.join(working_dir, "vpcs", "device-{}".format(self._id))
+        try:
+            os.makedirs(working_dir)
+        except FileExistsError:
+            pass
+        except OSError as e:
+            raise VPCSError("Could not create working directory {}: {}".format(working_dir, e))
+
+        self._working_dir = working_dir
+        log.info("VPCS {name} [id={id}]: working directory changed to {wd}".format(name=self._name,
+                                                                                    id=self._id,
+                                                                                    wd=self._working_dir))
+
+    @property
+    def console(self):
+        """
+        Returns the TCP console port.
+
+        :returns: console port (integer)
+        """
+
+        return self._console
+
+    @console.setter
+    def console(self, console):
+        """
+        Sets the TCP console port.
+
+        :param console: console port (integer)
+        """
+
+        self._console = console
+        log.info("VPCS {name} [id={id}]: console port set to {port}".format(name=self._name,
+                                                                         id=self._id,
+                                                                         port=console))
+
+    def command(self):
+        """
+        Returns the VPCS command line.
+
+        :returns: VPCS command line (string)
+        """
+
+        return " ".join(self._build_command())
+
+    def delete(self):
+        """
+        Deletes this VPCS device.
+        """
+
+        self.stop()
+        self._instances.remove(self._id)
+        log.info("VPCS device {name} [id={id}] has been deleted".format(name=self._name,
+                                                                       id=self._id))
+
+    @property
+    def started(self):
+        """
+        Returns either this VPCS device has been started or not.
+
+        :returns: boolean
+        """
+
+        return self._started
+
+    def _start_vpcscon(self):
+        """
+        Starts vpcscon thread (for console connections).
+        """
+
+        if not self._vpcscon_thead:
+            telnet_server = "{}:{}".format(self._host, self._console)
+            log.info("starting vpcscon for VPCS instance {} to accept Telnet connections on {}".format(self._name, telnet_server))
+            args = argparse.Namespace(appl_id=str(self._id), debug=False, escape='^^', telnet_limit=0, telnet_server=telnet_server)
+            self._vpcscon_thread_stop_event = threading.Event()
+            self._vpcscon_thead = threading.Thread(target=start_vpcscon, args=(args, self._vpcscon_thread_stop_event))
+            self._vpcscon_thead.start()                                                                                                     ", ".join(missing_libs)))
+
+    def start(self):
+        """
+        Starts the VPCS process.
+        """
+
+        if not self.is_running():
+
+            if not os.path.isfile(self._path):
+                raise VPCSError("VPCS image '{}' is not accessible".format(self._path))
+
+            if not os.access(self._path, os.X_OK):
+                raise VPCSError("VPCS image '{}' is not executable".format(self._path))
+
+            self._command = self._build_command()
+            try:
+                log.info("starting VPCS: {}".format(self._command))
+                self._vpcs_stdout_file = os.path.join(self._working_dir, "vpcs.log")
+                log.info("logging to {}".format(self._vpcs_stdout_file))
+                with open(self._vpcs_stdout_file, "w") as fd:
+                    self._process = subprocess.Popen(self._command,
+                                                     stdout=fd,
+                                                     stderr=subprocess.STDOUT,
+                                                     cwd=self._working_dir)
+                log.info("VPCS instance {} started PID={}".format(self._id, self._process.pid))
+                self._started = True
+            except FileNotFoundError as e:
+                raise VPCSError("could not start VPCS: {}: 32-bit binary support is probably not installed".format(e))
+            except OSError as e:
+                vpcs_stdout = self.read_vpcs_stdout()
+                log.error("could not start VPCS {}: {}\n{}".format(self._path, e, vpcs_stdout))
+                raise VPCSError("could not start VPCS {}: {}\n{}".format(self._path, e, vpcs_stdout))
+
+            # start console support
+            self._start_vpcscon()
+
+    def stop(self):
+        """
+        Stops the VPCS process.
+        """
+
+        # stop the VPCS process
+        if self.is_running():
+            log.info("stopping VPCS instance {} PID={}".format(self._id, self._process.pid))
+            try:
+                self._process.terminate()
+                self._process.wait(1)
+            except subprocess.TimeoutExpired:
+                self._process.kill()
+                if self._process.poll() == None:
+                    log.warn("VPCS instance {} PID={} is still running".format(self._id,
+                                                                              self._process.pid))
+        self._process = None
+        self._started = False
+
+        # stop console support
+        if self._vpcscon_thead:
+            self._vpcscon_thread_stop_event.set()
+            if self._vpcscon_thead.is_alive():
+                self._vpcscon_thead.join(timeout=0.10)
+            self._vpcscon_thead = None
+
+
+    def read_vpcs_stdout(self):
+        """
+        Reads the standard output of the VPCS process.
+        Only use when the process has been stopped or has crashed.
+        """
+
+        output = ""
+        if self._vpcs_stdout_file:
+            try:
+                with open(self._vpcs_stdout_file) as file:
+                    output = file.read()
+            except OSError as e:
+                log.warn("could not read {}: {}".format(self._vpcs_stdout_file, e))
+        return output
+
+    def is_running(self):
+        """
+        Checks if the VPCS process is running
+
+        :returns: True or False
+        """
+
+        if self._process and self._process.poll() == None:
+            return True
+        return False
+
+
+    def slot_add_nio_binding(self, slot_id, port_id, nio):
+        """
+        Adds a slot NIO binding.
+
+        :param slot_id: slot ID
+        :param port_id: port ID
+        :param nio: NIO instance to add to the slot/port
+        """
+
+        try:
+            adapter = self._slots[slot_id]
+        except IndexError:
+            raise VPCSError("Slot {slot_id} doesn't exist on VPCS {name}".format(name=self._name,
+                                                                               slot_id=slot_id))
+
+        if not adapter.port_exists(port_id):
+            raise VPCSError("Port {port_id} doesn't exist in adapter {adapter}".format(adapter=adapter,
+                                                                                      port_id=port_id))
+
+        adapter.add_nio(port_id, nio)
+        log.info("VPCS {name} [id={id}]: {nio} added to {slot_id}/{port_id}".format(name=self._name,
+                                                                                   id=self._id,
+                                                                                   nio=nio,
+                                                                                   slot_id=slot_id,
+                                                                                   port_id=port_id))
+
+    def slot_remove_nio_binding(self, slot_id, port_id):
+        """
+        Removes a slot NIO binding.
+
+        :param slot_id: slot ID
+        :param port_id: port ID
+        """
+
+        try:
+            adapter = self._slots[slot_id]
+        except IndexError:
+            raise VPCSError("Slot {slot_id} doesn't exist on VPCS {name}".format(name=self._name,
+                                                                               slot_id=slot_id))
+
+        if not adapter.port_exists(port_id):
+            raise VPCSError("Port {port_id} doesn't exist in adapter {adapter}".format(adapter=adapter,
+                                                                                      port_id=port_id))
+
+        nio = adapter.get_nio(port_id)
+        adapter.remove_nio(port_id)
+        log.info("VPCS {name} [id={id}]: {nio} removed from {slot_id}/{port_id}".format(name=self._name,
+                                                                                       id=self._id,
+                                                                                       nio=nio,
+                                                                                       slot_id=slot_id,
+                                                                                       port_id=port_id))
+
+    def _build_command(self):
+        """
+        Command to start the VPCS process.
+        (to be passed to subprocess.Popen())
+
+        VPCS command line:
+        usage: vpcs [options] [scriptfile]
+        Option:
+            -h         print this help then exit
+            -v         print version information then exit
+
+            -p port    run as a daemon listening on the tcp 'port'
+            -m num     start byte of ether address, default from 0
+            -r file    load and execute script file
+                       compatible with older versions, DEPRECATED.
+
+            -e         tap mode, using /dev/tapx (linux only)
+            -u         udp mode, default
+
+        udp mode options:
+            -s port    local udp base port, default from 20000
+            -c port    remote udp base port (dynamips udp port), default from 30000
+            -t ip      remote host IP, default 127.0.0.1
+
+        hypervisor mode option:
+            -H port    run as the hypervisor listening on the tcp 'port'
+
+          If no 'scriptfile' specified, vpcs will read and execute the file named
+          'startup.vpc' if it exsits in the current directory.
+
+        """
+
+        command = [self._path]
+        command.extend(["-p", str(self._console)])
+        command.extend(["-s", str(self._lport)])
+        command.extend(["-c", str(self._rport)])
+        command.extend(["-t", str(self._rhost)])
+        command.extend(["-m", str(self._id)]) #The unique ID is used to set the mac address offset
+        if self._script_file:
+            command.extend([self._script_file])
+        return command
+
+    @property
+    def script_file(self):
+        """
+        Returns the startup-config for this VPCS instance.
+
+        :returns: path to startup-config file
+        """
+
+        return self._script_file
+
+    @script_file.setter
+    def script_file(self, script_file):
+        """
+        Sets the startup-config for this VPCS instance.
+
+        :param script_file: path to startup-config file
+        """
+
+        self._script_file = script_file
+        log.info("VPCS {name} [id={id}]: script_file set to {config}".format(name=self._name,
+                                                                                 id=self._id,
+                                                                                 config=self._script_file))
+
+

gns3server/modules/vpcs/vpcs_error.py

@@ -15,13 +15,25 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import sys
+"""
-from .base import IModule
+Custom exceptions for VPCS module.
-from .dynamips import Dynamips
+"""
 
-MODULES = [Dynamips]
 
-if sys.platform.startswith("linux"):
+class VPCSError(Exception):
-    # IOU runs only on Linux
+
-    from .iou import IOU
+    def __init__(self, message, original_exception=None):
-    MODULES.append(IOU)
+
+        Exception.__init__(self, message)
+        if isinstance(message, Exception):
+            message = str(message)
+        self._message = message
+        self._original_exception = original_exception
+
+    def __repr__(self):
+
+        return self._message
+
+    def __str__(self):
+
+        return self._message

gns3server/modules/vpcs/vpcscon.py

@@ -0,0 +1,642 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2013, 2014  James E. Carpenter
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import socket
+import sys
+import os
+import select
+import fcntl
+import struct
+import termios
+import tty
+import time
+import argparse
+import traceback
+
+
+import logging
+log = logging.getLogger(__name__)
+
+
+# Escape characters
+ESC_CHAR = '^^'         # can be overriden from command line
+ESC_QUIT = 'q'
+
+# VPCS seems to only send *1* byte at a time. If
+# they ever fix that we'll be ready for it.
+BUFFER_SIZE = 1024
+
+# How long to wait before retrying a connection (seconds)
+RETRY_DELAY = 3
+
+# How often to test an idle connection (seconds)
+POLL_TIMEOUT = 3
+
+
+EXIT_SUCCESS = 0
+EXIT_FAILURE = 1
+EXIT_ABORT = 2
+
+# Mostly from:
+# https://code.google.com/p/miniboa/source/browse/trunk/miniboa/telnet.py
+#--[ Telnet Commands ]---------------------------------------------------------
+SE     = 240 # End of subnegotiation parameters
+NOP    = 241 # No operation
+DATMK  = 242 # Data stream portion of a sync.
+BREAK  = 243 # NVT Character BRK
+IP     = 244 # Interrupt Process
+AO     = 245 # Abort Output
+AYT    = 246 # Are you there
+EC     = 247 # Erase Character
+EL     = 248 # Erase Line
+GA     = 249 # The Go Ahead Signal
+SB     = 250 # Sub-option to follow
+WILL   = 251 # Will; request or confirm option begin
+WONT   = 252 # Wont; deny option request
+DO     = 253 # Do = Request or confirm remote option
+DONT   = 254 # Don't = Demand or confirm option halt
+IAC    = 255 # Interpret as Command
+SEND   = 1   # Sub-process negotiation SEND command
+IS     = 0   # Sub-process negotiation IS command
+#--[ Telnet Options ]----------------------------------------------------------
+BINARY = 0   # Transmit Binary
+ECHO   = 1   # Echo characters back to sender
+RECON  = 2   # Reconnection
+SGA    = 3   # Suppress Go-Ahead
+TMARK  = 6   # Timing Mark
+TTYPE  = 24  # Terminal Type
+NAWS   = 31  # Negotiate About Window Size
+LINEMO = 34  # Line Mode
+
+
+class FileLock:
+
+    # struct flock {       /* from fcntl(2) */
+    #     ...
+    #     short l_type;    /* Type of lock: F_RDLCK,
+    #                         F_WRLCK, F_UNLCK */
+    #     short l_whence;  /* How to interpret l_start:
+    #                         SEEK_SET, SEEK_CUR, SEEK_END */
+    #     off_t l_start;   /* Starting offset for lock */
+    #     off_t l_len;     /* Number of bytes to lock */
+    #     pid_t l_pid;     /* PID of process blocking our lock
+    #                         (F_GETLK only) */
+    #     ...
+    # };
+    _flock = struct.Struct('hhqql')
+
+    def __init__(self, fname=None):
+        self.fd = None
+        self.fname = fname
+
+    def get_lock(self):
+        flk = self._flock.pack(fcntl.F_WRLCK, os.SEEK_SET,
+                               0, 0, os.getpid())
+        flk = self._flock.unpack(
+            fcntl.fcntl(self.fd, fcntl.F_GETLK, flk))
+
+        # If it's not locked (or is locked by us) then return None,
+        # otherwise return the PID of the owner.
+        if flk[0] == fcntl.F_UNLCK:
+            return None
+        return flk[4]
+
+    def lock(self):
+        try:
+            self.fd = open('{}.lck'.format(self.fname), 'a')
+        except Exception as e:
+            raise LockError("Couldn't get lock on {}: {}"
+                            .format(self.fname, e))
+
+        flk = self._flock.pack(fcntl.F_WRLCK, os.SEEK_SET, 0, 0, 0)
+        try:
+            fcntl.fcntl(self.fd, fcntl.F_SETLK, flk)
+        except BlockingIOError:
+            raise LockError("Already connected. PID {} has lock on {}"
+                            .format(self.get_lock(), self.fname))
+
+        # If we got here then we must have the lock. Store the PID.
+        self.fd.truncate(0)
+        self.fd.write('{}\n'.format(os.getpid()))
+        self.fd.flush()
+
+    def unlock(self):
+        if self.fd:
+            # Deleting first prevents a race condition
+            os.unlink(self.fd.name)
+            self.fd.close()
+
+    def __enter__(self):
+        self.lock()
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.unlock()
+        return False
+
+
+class Console:
+    def fileno(self):
+        raise NotImplementedError("Only routers have fileno()")
+
+
+class Router:
+    pass
+
+
+class TTY(Console):
+
+    def read(self, fileno, bufsize):
+        return self.fd.read(bufsize)
+
+    def write(self, buf):
+        return self.fd.write(buf)
+
+    def register(self, epoll):
+        self.epoll = epoll
+        epoll.register(self.fd, select.EPOLLIN | select.EPOLLET)
+
+    def __enter__(self):
+        try:
+            self.fd = open('/dev/tty', 'r+b', buffering=0)
+        except OSError as e:
+            raise TTYError("Couldn't open controlling TTY: {}".format(e))
+
+        # Save original flags
+        self.termios = termios.tcgetattr(self.fd)
+        self.fcntl = fcntl.fcntl(self.fd, fcntl.F_GETFL)
+
+        # Update flags
+        tty.setraw(self.fd, termios.TCSANOW)
+        fcntl.fcntl(self.fd, fcntl.F_SETFL, self.fcntl | os.O_NONBLOCK)
+
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+
+        # Restore flags to original settings
+        termios.tcsetattr(self.fd, termios.TCSANOW, self.termios)
+        fcntl.fcntl(self.fd, fcntl.F_SETFL, self.fcntl)
+
+        self.fd.close()
+
+        return False
+
+
+class TelnetServer(Console):
+
+    def __init__(self, addr, port, stop_event):
+        self.addr = addr
+        self.port = port
+        self.fd_dict = {}
+        self.stop_event = stop_event
+
+    def read(self, fileno, bufsize):
+        # Someone wants to connect?
+        if fileno == self.sock_fd.fileno():
+            self._accept()
+            return None
+
+        self._cur_fileno = fileno
+
+        # Read a maximum of _bufsize_ bytes without blocking. When it
+        # would want to block it means there's no more data. An empty
+        # buffer normally means that we've been disconnected.
+        try:
+            buf = self._read_cur(bufsize, socket.MSG_DONTWAIT)
+        except BlockingIOError:
+            return None
+        if not buf:
+            self._disconnect(fileno)
+
+        # Process and remove any telnet commands from the buffer
+        if IAC in buf:
+            buf = self._IAC_parser(buf)
+
+        return buf
+
+    def write(self, buf):
+        for fd in self.fd_dict.values():
+            fd.send(buf)
+
+    def register(self, epoll):
+        self.epoll = epoll
+        epoll.register(self.sock_fd, select.EPOLLIN)
+
+    def _read_block(self, bufsize):
+        buf = self._read_cur(bufsize, socket.MSG_WAITALL)
+        # If we don't get everything we were looking for then the
+        # client probably disconnected.
+        if len(buf) < bufsize:
+            self._disconnect(self._cur_fileno)
+        return buf
+
+    def _read_cur(self, bufsize, flags):
+        return self.fd_dict[self._cur_fileno].recv(bufsize, flags)
+
+    def _write_cur(self, buf):
+        return self.fd_dict[self._cur_fileno].send(buf)
+
+    def _IAC_parser(self, buf):
+        skip_to = 0
+        while not self.stop_event.is_set():
+            # Locate an IAC to process
+            iac_loc = buf.find(IAC, skip_to)
+            if iac_loc < 0:
+                break
+
+            # Get the TELNET command
+            iac_cmd = bytearray([IAC])
+            try:
+                iac_cmd.append(buf[iac_loc + 1])
+            except IndexError:
+                buf.extend(self._read_block(1))
+                iac_cmd.append(buf[iac_loc + 1])
+
+            # Is this just a 2-byte TELNET command?
+            if iac_cmd[1] not in [WILL, WONT, DO, DONT]:
+                if iac_cmd[1] == AYT:
+                    log.debug("Telnet server received Are-You-There (AYT)")
+                    self._write_cur(
+                        b'\r\nYour Are-You-There received. I am here.\r\n'
+                    )
+                elif iac_cmd[1] == IAC:
+                    # It's data, not an IAC
+                    iac_cmd.pop()
+                    # This prevents the 0xff from being
+                    # interputed as yet another IAC
+                    skip_to = iac_loc + 1
+                    log.debug("Received IAC IAC")
+                elif iac_cmd[1] == NOP:
+                    pass
+                else:
+                    log.debug("Unhandled telnet command: "
+                              "{0:#x} {1:#x}".format(*iac_cmd))
+
+            # This must be a 3-byte TELNET command
+            else:
+                try:
+                    iac_cmd.append(buf[iac_loc + 2])
+                except IndexError:
+                    buf.extend(self._read_block(1))
+                    iac_cmd.append(buf[iac_loc + 2])
+                # We do ECHO, SGA, and BINARY. Period.
+                if (iac_cmd[1] == DO
+                    and iac_cmd[2] not in [ECHO, SGA, BINARY]):
+
+                    self._write_cur(bytes([IAC, WONT, iac_cmd[2]]))
+                    log.debug("Telnet WON'T {:#x}".format(iac_cmd[2]))
+                else:
+                    log.debug("Unhandled telnet command: "
+                              "{0:#x} {1:#x} {2:#x}".format(*iac_cmd))
+
+            # Remove the entire TELNET command from the buffer
+            buf = buf.replace(iac_cmd, b'', 1)
+
+        # Return the new copy of the buffer, minus telnet commands
+        return buf
+
+    def _accept(self):
+        fd, addr = self.sock_fd.accept()
+        self.fd_dict[fd.fileno()] = fd
+        self.epoll.register(fd, select.EPOLLIN | select.EPOLLET)
+
+        log.info("Telnet connection from {}:{}".format(addr[0], addr[1]))
+
+        # This is a one-way negotiation. This is very basic so there
+        # shouldn't be any problems with any decent client.
+        fd.send(bytes([IAC, WILL, ECHO,
+                       IAC, WILL, SGA,
+                       IAC, WILL, BINARY,
+                       IAC, DO,   BINARY]))
+
+        if args.telnet_limit and len(self.fd_dict) > args.telnet_limit:
+            fd.send(b'\r\nToo many connections\r\n')
+            self._disconnect(fd.fileno())
+            log.warn("Client disconnected because of too many connections. "
+                     "(limit currently {})".format(args.telnet_limit))
+
+    def _disconnect(self, fileno):
+        fd = self.fd_dict.pop(fileno)
+        log.info("Telnet client disconnected")
+        fd.shutdown(socket.SHUT_RDWR)
+        fd.close()
+
+    def __enter__(self):
+        # Open a socket and start listening
+        sock_fd = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        sock_fd.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        try:
+            sock_fd.bind((self.addr, self.port))
+        except OSError:
+            raise TelnetServerError("Cannot bind to {}:{}"
+                                    .format(self.addr, self.port))
+
+        sock_fd.listen(socket.SOMAXCONN)
+        self.sock_fd = sock_fd
+        log.info("Telnet server ready for connections on {}:{}".format(self.addr, self.port))
+
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        for fileno in list(self.fd_dict.keys()):
+            self._disconnect(fileno)
+        self.sock_fd.close()
+        return False
+
+
+class VPCS(Router):
+
+    def __init__(self, ttyC, ttyS, stop_event):
+        self.ttyC = ttyC
+        self.ttyS = ttyS
+        self.stop_event = stop_event
+
+    def read(self, bufsize):
+        try:
+            buf = self.fd.recv(bufsize)
+        except BlockingIOError:
+            return None
+        return buf
+
+    def write(self, buf):
+        self.fd.send(buf)
+
+    def _open(self):
+        self.fd = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+        self.fd.setblocking(False)
+
+    def _bind(self):
+        try:
+            os.unlink(self.ttyC)
+        except FileNotFoundError:
+            pass
+        except Exception as e:
+            raise NetioError("Couldn't unlink socket {}: {}"
+                             .format(self.ttyC, e))
+
+        try:
+            self.fd.bind(self.ttyC)
+        except Exception as e:
+            raise NetioError("Couldn't create socket {}: {}"
+                             .format(self.ttyC, e))
+
+    def _connect(self):
+        # Keep trying until we connect or die trying
+        while not self.stop_event.is_set():
+            try:
+                self.fd.connect(self.ttyS)
+            except FileNotFoundError:
+                log.debug("Waiting to connect to {}".format(self.ttyS))
+                time.sleep(RETRY_DELAY)
+            except Exception as e:
+                raise NetioError("Couldn't connect to socket {}: {}"
+                                 .format(self.ttyS, e))
+            else:
+                break
+
+    def register(self, epoll):
+        self.epoll = epoll
+        epoll.register(self.fd, select.EPOLLIN | select.EPOLLET)
+
+    def fileno(self):
+        return self.fd.fileno()
+
+    def __enter__(self):
+        self._open()
+        self._bind()
+        self._connect()
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        os.unlink(self.ttyC)
+        self.fd.close()
+        return False
+
+
+class VPCSConError(Exception):
+    pass
+
+
+class LockError(VPCSConError):
+    pass
+
+
+class NetioError(VPCSConError):
+    pass
+
+
+class TTYError(VPCSConError):
+    pass
+
+
+class TelnetServerError(VPCSConError):
+    pass
+
+
+class ConfigError(VPCSConError):
+    pass
+
+
+def mkdir_netio(netio_dir):
+    try:
+        os.mkdir(netio_dir)
+    except FileExistsError:
+        pass
+    except Exception as e:
+        raise NetioError("Couldn't create directory {}: {}"
+                         .format(netio_dir, e))
+
+
+def send_recv_loop(console, router, esc_char, stop_event):
+
+    epoll = select.epoll()
+    router.register(epoll)
+    console.register(epoll)
+
+    router_fileno = router.fileno()
+    esc_quit = bytes(ESC_QUIT.upper(), 'ascii')
+    esc_state = False
+
+    while not stop_event.is_set():
+        event_list = epoll.poll(timeout=POLL_TIMEOUT)
+
+        # When/if the poll times out we send an empty datagram. If VPCS
+        # has gone away then this will toss a ConnectionRefusedError
+        # exception.
+        if not event_list:
+            router.write(b'')
+            continue
+
+        for fileno, event in event_list:
+            buf = bytearray()
+
+            # VPCS --> tty(s)
+            if fileno == router_fileno:
+                while not stop_event.is_set():
+                    data = router.read(BUFFER_SIZE)
+                    if not data:
+                        break
+                    buf.extend(data)
+                console.write(buf)
+
+            # tty --> VPCS
+            else:
+                while not stop_event.is_set():
+                    data = console.read(fileno, BUFFER_SIZE)
+                    if not data:
+                        break
+                    buf.extend(data)
+
+                # If we just received the escape character then
+                # enter the escape state.
+                #
+                # If we are in the escape state then check for a
+                # quit command. Or if it's the escape character then
+                # send the escape character. Else, send the escape
+                # character we ate earlier and whatever character we
+                # just got. Exit escape state.
+                #
+                # If we're not in the escape state and this isn't an
+                # escape character then just send it to VPCS.
+                if esc_state:
+                    if buf.upper() == esc_quit:
+                        sys.exit(EXIT_SUCCESS)
+                    elif buf == esc_char:
+                        router.write(esc_char)
+                    else:
+                        router.write(esc_char)
+                        router.write(buf)
+                    esc_state = False
+                elif buf == esc_char:
+                    esc_state = True
+                else:
+                    router.write(buf)
+
+
+def get_args():
+    parser = argparse.ArgumentParser(
+        description='Connect to an VPCS console port.')
+    parser.add_argument('-d', '--debug', action='store_true',
+                        help='display some debugging information')
+    parser.add_argument('-e', '--escape',
+                        help='set escape character (default: %(default)s)',
+                        default=ESC_CHAR, metavar='CHAR')
+    parser.add_argument('-t', '--telnet-server',
+                        help='start telnet server listening on ADDR:PORT',
+                        metavar='ADDR:PORT', default=False)
+    parser.add_argument('-l', '--telnet-limit',
+                        help='maximum number of simultaneous '
+                        'telnet connections (default: %(default)s)',
+                        metavar='LIMIT', type=int, default=1)
+    parser.add_argument('appl_id', help='VPCS instance identifier')
+    return parser.parse_args()
+
+
+def get_escape_character(escape):
+
+    # Figure out the escape character to use.
+    # Can be any ASCII character or a spelled out control
+    # character, like "^e". The string "none" disables it.
+    if escape.lower() == 'none':
+        esc_char = b''
+    elif len(escape) == 2 and escape[0] == '^':
+        c = ord(escape[1].upper()) - 0x40
+        if not 0 <= c <= 0x1f:  # control code range
+            raise ConfigError("Invalid control code")
+        esc_char = bytes([c])
+    elif len(escape) == 1:
+        try:
+            esc_char = bytes(escape, 'ascii')
+        except ValueError as e:
+            raise ConfigError("Invalid escape character") from e
+    else:
+        raise ConfigError("Invalid length for escape character")
+
+    return esc_char
+
+
+def start_VPCScon(cmdline_args, stop_event):
+
+    global args
+    args = cmdline_args
+
+    if args.debug:
+        logging.basicConfig(level=logging.DEBUG)
+    else:
+        # default logging level
+        logging.basicConfig(level=logging.INFO)
+
+    # Create paths for the Unix domain sockets
+    netio = '/tmp/netio{}'.format(os.getuid())
+    ttyC = '{}/ttyC{}'.format(netio, args.appl_id)
+    ttyS = '{}/ttyS{}'.format(netio, args.appl_id)
+
+    try:
+        mkdir_netio(netio)
+        with FileLock(ttyC):
+            esc_char = get_escape_character(args.escape)
+
+            if args.telnet_server:
+                addr, _, port = args.telnet_server.partition(':')
+                nport = 0
+                try:
+                    nport = int(port)
+                except ValueError:
+                    pass
+                if (addr == '' or nport == 0):
+                    raise ConfigError('format for --telnet-server must be '
+                                      'ADDR:PORT (like 127.0.0.1:20000)')
+
+            while not stop_event.is_set():
+                try:
+                    if args.telnet_server:
+                        with TelnetServer(addr, nport, stop_event) as console:
+                            with VPCS(ttyC, ttyS, stop_event) as router:
+                                send_recv_loop(console, router, b'', stop_event)
+                    else:
+                        with VPCS(ttyC, ttyS, stop_event) as router, TTY() as console:
+                            send_recv_loop(console, router, esc_char, stop_event)
+                except ConnectionRefusedError:
+                    pass
+                except KeyboardInterrupt:
+                    sys.exit(EXIT_ABORT)
+                finally:
+                    # Put us at the beginning of a line
+                    if not args.telnet_server:
+                        print()
+
+    except VPCSConError as e:
+        if args.debug:
+            traceback.print_exc(file=sys.stderr)
+        else:
+            print(e, file=sys.stderr)
+        sys.exit(EXIT_FAILURE)
+
+    log.info("exiting...")
+
+
+def main():
+
+    import threading
+    stop_event = threading.Event()
+    args = get_args()
+    start_VPCScon(args, stop_event)
+
+if __name__ == '__main__':
+    main()