/mandos/trunk

#!/usr/bin/python3 -bbI
# -*- mode: python; coding: utf-8 -*-
#
# Mandos Monitor - Control and monitor the Mandos server
#
# Copyright © 2009-2019 Teddy Hogeborn
# Copyright © 2009-2019 Björn Påhlsson
#
# This file is part of Mandos.
#
# Mandos 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.
#
#     Mandos 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 Mandos.  If not, see <http://www.gnu.org/licenses/>.
#
# Contact the authors at <mandos@recompile.se>.
#
from __future__ import (division, absolute_import, print_function,
                        unicode_literals)

try:
    from future_builtins import *
except ImportError:
    pass

import sys
import logging
import os
import warnings
import datetime
import locale

import urwid.curses_display
import urwid

from dbus.mainloop.glib import DBusGMainLoop
from gi.repository import GLib

import dbus

if sys.version_info.major == 2:
    __metaclass__ = type
    str = unicode
    input = raw_input

# Show warnings by default
if not sys.warnoptions:
    warnings.simplefilter("default")

log = logging.getLogger(os.path.basename(sys.argv[0]))
logging.basicConfig(level="NOTSET", # Show all messages
                    format="%(message)s") # Show basic log messages

logging.captureWarnings(True)   # Show warnings via the logging system

locale.setlocale(locale.LC_ALL, "")

logging.getLogger("dbus.proxies").setLevel(logging.CRITICAL)
logging.getLogger("urwid").setLevel(logging.INFO)

# Some useful constants
domain = "se.recompile"
server_interface = domain + ".Mandos"
client_interface = domain + ".Mandos.Client"
version = "1.8.18"

try:
    dbus.OBJECT_MANAGER_IFACE
except AttributeError:
    dbus.OBJECT_MANAGER_IFACE = "org.freedesktop.DBus.ObjectManager"


def isoformat_to_datetime(iso):
    "Parse an ISO 8601 date string to a datetime.datetime()"
    if not iso:
        return None
    d, t = iso.split("T", 1)
    year, month, day = d.split("-", 2)
    hour, minute, second = t.split(":", 2)
    second, fraction = divmod(float(second), 1)
    return datetime.datetime(int(year),
                             int(month),
                             int(day),
                             int(hour),
                             int(minute),
                             int(second),            # Whole seconds
                             int(fraction*1000000))  # Microseconds


class MandosClientPropertyCache:
    """This wraps a Mandos Client D-Bus proxy object, caches the
    properties and calls a hook function when any of them are
    changed.
    """
    def __init__(self, proxy_object=None, properties=None, **kwargs):
        self.proxy = proxy_object  # Mandos Client proxy object
        self.properties = dict() if properties is None else properties
        self.property_changed_match = (
            self.proxy.connect_to_signal("PropertiesChanged",
                                         self.properties_changed,
                                         dbus.PROPERTIES_IFACE,
                                         byte_arrays=True))

        if properties is None:
            self.properties.update(self.proxy.GetAll(
                client_interface,
                dbus_interface=dbus.PROPERTIES_IFACE))

        super(MandosClientPropertyCache, self).__init__(**kwargs)

    def properties_changed(self, interface, properties, invalidated):
        """This is called whenever we get a PropertiesChanged signal
        It updates the changed properties in the "properties" dict.
        """
        # Update properties dict with new value
        if interface == client_interface:
            self.properties.update(properties)

    def delete(self):
        self.property_changed_match.remove()


class MandosClientWidget(MandosClientPropertyCache, urwid.Widget):
    """A Mandos Client which is visible on the screen.
    """

    _sizing = frozenset(["flow"])

    def __init__(self, server_proxy_object=None, update_hook=None,
                 delete_hook=None, **kwargs):
        # Called on update
        self.update_hook = update_hook
        # Called on delete
        self.delete_hook = delete_hook
        # Mandos Server proxy object
        self.server_proxy_object = server_proxy_object

        self._update_timer_callback_tag = None

        # The widget shown normally
        self._text_widget = urwid.Text("")
        # The widget shown when we have focus
        self._focus_text_widget = urwid.Text("")
        super(MandosClientWidget, self).__init__(**kwargs)
        self.update()
        self.opened = False

        self.match_objects = (
            self.proxy.connect_to_signal("CheckerCompleted",
                                         self.checker_completed,
                                         client_interface,
                                         byte_arrays=True),
            self.proxy.connect_to_signal("CheckerStarted",
                                         self.checker_started,
                                         client_interface,
                                         byte_arrays=True),
            self.proxy.connect_to_signal("GotSecret",
                                         self.got_secret,
                                         client_interface,
                                         byte_arrays=True),
            self.proxy.connect_to_signal("NeedApproval",
                                         self.need_approval,
                                         client_interface,
                                         byte_arrays=True),
            self.proxy.connect_to_signal("Rejected",
                                         self.rejected,
                                         client_interface,
                                         byte_arrays=True))
        log.debug("Created client %s", self.properties["Name"])

    def using_timer(self, flag):
        """Call this method with True or False when timer should be
        activated or deactivated.
        """
        if flag and self._update_timer_callback_tag is None:
            # Will update the shown timer value every second
            self._update_timer_callback_tag = (
                GLib.timeout_add(1000,
                                 glib_safely(self.update_timer)))
        elif not (flag or self._update_timer_callback_tag is None):
            GLib.source_remove(self._update_timer_callback_tag)
            self._update_timer_callback_tag = None

    def checker_completed(self, exitstatus, condition, command):
        if exitstatus == 0:
            log.debug('Checker for client %s (command "%s")'
                      " succeeded", self.properties["Name"], command)
            self.update()
            return
        # Checker failed
        if os.WIFEXITED(condition):
            log.info('Checker for client %s (command "%s") failed'
                     " with exit code %d", self.properties["Name"],
                     command, os.WEXITSTATUS(condition))
        elif os.WIFSIGNALED(condition):
            log.info('Checker for client %s (command "%s") was'
                     " killed by signal %d", self.properties["Name"],
                     command, os.WTERMSIG(condition))
        self.update()

    def checker_started(self, command):
        """Server signals that a checker started."""
        log.debug('Client %s started checker "%s"',
                  self.properties["Name"], command)

    def got_secret(self):
        log.info("Client %s received its secret",
                 self.properties["Name"])

    def need_approval(self, timeout, default):
        if not default:
            message = "Client %s needs approval within %f seconds"
        else:
            message = "Client %s will get its secret in %f seconds"
        log.info(message, self.properties["Name"], timeout/1000)

    def rejected(self, reason):
        log.info("Client %s was rejected; reason: %s",
                 self.properties["Name"], reason)

    def selectable(self):
        """Make this a "selectable" widget.
        This overrides the method from urwid.Widget."""
        return True

    def rows(self, maxcolrow, focus=False):
        """How many rows this widget will occupy might depend on
        whether we have focus or not.
        This overrides the method from urwid.Widget"""
        return self.current_widget(focus).rows(maxcolrow, focus=focus)

    def current_widget(self, focus=False):
        if focus or self.opened:
            return self._focus_widget
        return self._widget

    def update(self):
        "Called when what is visible on the screen should be updated."
        # How to add standout mode to a style
        with_standout = {"normal": "standout",
                         "bold": "bold-standout",
                         "underline-blink":
                         "underline-blink-standout",
                         "bold-underline-blink":
                         "bold-underline-blink-standout",
                         }

        # Rebuild focus and non-focus widgets using current properties

        # Base part of a client. Name!
        base = "{name}: ".format(name=self.properties["Name"])
        if not self.properties["Enabled"]:
            message = "DISABLED"
            self.using_timer(False)
        elif self.properties["ApprovalPending"]:
            timeout = datetime.timedelta(
                milliseconds=self.properties["ApprovalDelay"])
            last_approval_request = isoformat_to_datetime(
                self.properties["LastApprovalRequest"])
            if last_approval_request is not None:
                timer = max(timeout - (datetime.datetime.utcnow()
                                       - last_approval_request),
                            datetime.timedelta())
            else:
                timer = datetime.timedelta()
            if self.properties["ApprovedByDefault"]:
                message = "Approval in {}. (d)eny?"
            else:
                message = "Denial in {}. (a)pprove?"
            message = message.format(str(timer).rsplit(".", 1)[0])
            self.using_timer(True)
        elif self.properties["LastCheckerStatus"] != 0:
            # When checker has failed, show timer until client expires
            expires = self.properties["Expires"]
            if expires == "":
                timer = datetime.timedelta(0)
            else:
                expires = (datetime.datetime.strptime
                           (expires, "%Y-%m-%dT%H:%M:%S.%f"))
                timer = max(expires - datetime.datetime.utcnow(),
                            datetime.timedelta())
            message = ("A checker has failed! Time until client"
                       " gets disabled: {}"
                       .format(str(timer).rsplit(".", 1)[0]))
            self.using_timer(True)
        else:
            message = "enabled"
            self.using_timer(False)
        self._text = "{}{}".format(base, message)

        if not urwid.supports_unicode():
            self._text = self._text.encode("ascii", "replace")
        textlist = [("normal", self._text)]
        self._text_widget.set_text(textlist)
        self._focus_text_widget.set_text([(with_standout[text[0]],
                                           text[1])
                                          if isinstance(text, tuple)
                                          else text
                                          for text in textlist])
        self._widget = self._text_widget
        self._focus_widget = urwid.AttrWrap(self._focus_text_widget,
                                            "standout")
        # Run update hook, if any
        if self.update_hook is not None:
            self.update_hook()

    def update_timer(self):
        """called by GLib. Will indefinitely loop until
        GLib.source_remove() on tag is called
        """
        self.update()
        return True             # Keep calling this

    def delete(self, **kwargs):
        if self._update_timer_callback_tag is not None:
            GLib.source_remove(self._update_timer_callback_tag)
            self._update_timer_callback_tag = None
        for match in self.match_objects:
            match.remove()
        self.match_objects = ()
        if self.delete_hook is not None:
            self.delete_hook(self)
        return super(MandosClientWidget, self).delete(**kwargs)

    def render(self, maxcolrow, focus=False):
        """Render differently if we have focus.
        This overrides the method from urwid.Widget"""
        return self.current_widget(focus).render(maxcolrow,
                                                 focus=focus)

    def keypress(self, maxcolrow, key):
        """Handle keys.
        This overrides the method from urwid.Widget"""
        if key == "+":
            self.proxy.Set(client_interface, "Enabled",
                           dbus.Boolean(True), ignore_reply=True,
                           dbus_interface=dbus.PROPERTIES_IFACE)
        elif key == "-":
            self.proxy.Set(client_interface, "Enabled", False,
                           ignore_reply=True,
                           dbus_interface=dbus.PROPERTIES_IFACE)
        elif key == "a":
            self.proxy.Approve(dbus.Boolean(True, variant_level=1),
                               dbus_interface=client_interface,
                               ignore_reply=True)
        elif key == "d":
            self.proxy.Approve(dbus.Boolean(False, variant_level=1),
                               dbus_interface=client_interface,
                               ignore_reply=True)
        elif key == "R" or key == "_" or key == "ctrl k":
            self.server_proxy_object.RemoveClient(self.proxy
                                                  .object_path,
                                                  ignore_reply=True)
        elif key == "s":
            self.proxy.Set(client_interface, "CheckerRunning",
                           dbus.Boolean(True), ignore_reply=True,
                           dbus_interface=dbus.PROPERTIES_IFACE)
        elif key == "S":
            self.proxy.Set(client_interface, "CheckerRunning",
                           dbus.Boolean(False), ignore_reply=True,
                           dbus_interface=dbus.PROPERTIES_IFACE)
        elif key == "C":
            self.proxy.CheckedOK(dbus_interface=client_interface,
                                 ignore_reply=True)
        # xxx
#         elif key == "p" or key == "=":
#             self.proxy.pause()
#         elif key == "u" or key == ":":
#             self.proxy.unpause()
#         elif key == "RET":
#             self.open()
        else:
            return key

    def properties_changed(self, interface, properties, invalidated):
        """Call self.update() if any properties changed.
        This overrides the method from MandosClientPropertyCache"""
        old_values = {key: self.properties.get(key)
                      for key in properties.keys()}
        super(MandosClientWidget, self).properties_changed(
            interface, properties, invalidated)
        if any(old_values[key] != self.properties.get(key)
               for key in old_values):
            self.update()


def glib_safely(func, retval=True):
    def safe_func(*args, **kwargs):
        try:
            return func(*args, **kwargs)
        except Exception:
            log.exception("")
            return retval
    return safe_func


class ConstrainedListBox(urwid.ListBox):
    """Like a normal urwid.ListBox, but will consume all "up" or
    "down" key presses, thus not allowing any containing widgets to
    use them as an excuse to shift focus away from this widget.
    """
    def keypress(self, *args, **kwargs):
        ret = (super(ConstrainedListBox, self)
               .keypress(*args, **kwargs))
        if ret in ("up", "down"):
            return
        return ret


class UserInterface:
    """This is the entire user interface - the whole screen
    with boxes, lists of client widgets, etc.
    """
    def __init__(self, max_log_length=1000):
        DBusGMainLoop(set_as_default=True)

        self.screen = urwid.curses_display.Screen()

        self.screen.register_palette((
                ("normal",
                 "default", "default", None),
                ("bold",
                 "bold", "default", "bold"),
                ("underline-blink",
                 "underline,blink", "default", "underline,blink"),
                ("standout",
                 "standout", "default", "standout"),
                ("bold-underline-blink",
                 "bold,underline,blink", "default",
                 "bold,underline,blink"),
                ("bold-standout",
                 "bold,standout", "default", "bold,standout"),
                ("underline-blink-standout",
                 "underline,blink,standout", "default",
                 "underline,blink,standout"),
                ("bold-underline-blink-standout",
                 "bold,underline,blink,standout", "default",
                 "bold,underline,blink,standout"),
                ))

        if urwid.supports_unicode():
            self.divider = "─"  # \u2500
        else:
            self.divider = "_"  # \u005f

        self.screen.start()

        self.size = self.screen.get_cols_rows()

        self.clients = urwid.SimpleListWalker([])
        self.clients_dict = {}

        # We will add Text widgets to this list
        self.log = urwid.SimpleListWalker([])
        self.max_log_length = max_log_length

        # We keep a reference to the log widget so we can remove it
        # from the ListWalker without it getting destroyed
        self.logbox = ConstrainedListBox(self.log)

        # This keeps track of whether self.uilist currently has
        # self.logbox in it or not
        self.log_visible = True
        self.log_wrap = "any"

        self.loghandler = UILogHandler(self)

        self.rebuild()
        self.add_log_line(("bold",
                           "Mandos Monitor version " + version))
        self.add_log_line(("bold", "q: Quit  ?: Help"))

        self.busname = domain + ".Mandos"
        self.main_loop = GLib.MainLoop()

    def client_not_found(self, key_id, address):
        log.info("Client with address %s and key ID %s could"
                 " not be found", address, key_id)

    def rebuild(self):
        """This rebuilds the User Interface.
        Call this when the widget layout needs to change"""
        self.uilist = []
        # self.uilist.append(urwid.ListBox(self.clients))
        self.uilist.append(urwid.Frame(ConstrainedListBox(self.
                                                          clients),
                                       # header=urwid.Divider(),
                                       header=None,
                                       footer=urwid.Divider(
                                           div_char=self.divider)))
        if self.log_visible:
            self.uilist.append(self.logbox)
        self.topwidget = urwid.Pile(self.uilist)

    def add_log_line(self, markup):
        self.log.append(urwid.Text(markup, wrap=self.log_wrap))
        if self.max_log_length:
            if len(self.log) > self.max_log_length:
                del self.log[0:(len(self.log) - self.max_log_length)]
        self.logbox.set_focus(len(self.logbox.body.contents)-1,
                              coming_from="above")
        self.refresh()

    def toggle_log_display(self):
        """Toggle visibility of the log buffer."""
        self.log_visible = not self.log_visible
        self.rebuild()
        log.debug("Log visibility changed to: %s", self.log_visible)

    def change_log_display(self):
        """Change type of log display.
        Currently, this toggles wrapping of text lines."""
        if self.log_wrap == "clip":
            self.log_wrap = "any"
        else:
            self.log_wrap = "clip"
        for textwidget in self.log:
            textwidget.set_wrap_mode(self.log_wrap)
        log.debug("Wrap mode: %s", self.log_wrap)

    def find_and_remove_client(self, path, interfaces):
        """Find a client by its object path and remove it.

        This is connected to the InterfacesRemoved signal from the
        Mandos server object."""
        if client_interface not in interfaces:
            # Not a Mandos client object; ignore
            return
        try:
            client = self.clients_dict[path]
        except KeyError:
            # not found?
            log.warning("Unknown client %s removed", path)
            return
        client.delete()

    def add_new_client(self, path, ifs_and_props):
        """Find a client by its object path and remove it.

        This is connected to the InterfacesAdded signal from the
        Mandos server object.
        """
        if client_interface not in ifs_and_props:
            # Not a Mandos client object; ignore
            return
        client_proxy_object = self.bus.get_object(self.busname, path)
        self.add_client(MandosClientWidget(
            server_proxy_object=self.mandos_serv,
            proxy_object=client_proxy_object,
            update_hook=self.refresh,
            delete_hook=self.remove_client,
            properties=dict(ifs_and_props[client_interface])),
                        path=path)

    def add_client(self, client, path=None):
        self.clients.append(client)
        if path is None:
            path = client.proxy.object_path
        self.clients_dict[path] = client
        self.clients.sort(key=lambda c: c.properties["Name"])
        self.refresh()

    def remove_client(self, client, path=None):
        self.clients.remove(client)
        if path is None:
            path = client.proxy.object_path
        del self.clients_dict[path]
        self.refresh()

    def refresh(self):
        """Redraw the screen"""
        canvas = self.topwidget.render(self.size, focus=True)
        self.screen.draw_screen(self.size, canvas)

    def run(self):
        """Start the main loop and exit when it's done."""
        log.addHandler(self.loghandler)
        self.orig_log_propagate = log.propagate
        log.propagate = False
        self.orig_log_level = log.level
        log.setLevel("INFO")
        self.bus = dbus.SystemBus()
        mandos_dbus_objc = self.bus.get_object(
            self.busname, "/", follow_name_owner_changes=True)
        self.mandos_serv = dbus.Interface(
            mandos_dbus_objc, dbus_interface=server_interface)
        try:
            mandos_clients = (self.mandos_serv
                              .GetAllClientsWithProperties())
            if not mandos_clients:
                log.warning("Note: Server has no clients.")
        except dbus.exceptions.DBusException:
            log.warning("Note: No Mandos server running.")
            mandos_clients = dbus.Dictionary()

        (self.mandos_serv
         .connect_to_signal("InterfacesRemoved",
                            self.find_and_remove_client,
                            dbus_interface=dbus.OBJECT_MANAGER_IFACE,
                            byte_arrays=True))
        (self.mandos_serv
         .connect_to_signal("InterfacesAdded",
                            self.add_new_client,
                            dbus_interface=dbus.OBJECT_MANAGER_IFACE,
                            byte_arrays=True))
        (self.mandos_serv
         .connect_to_signal("ClientNotFound",
                            self.client_not_found,
                            dbus_interface=server_interface,
                            byte_arrays=True))
        for path, client in mandos_clients.items():
            client_proxy_object = self.bus.get_object(self.busname,
                                                      path)
            self.add_client(MandosClientWidget(
                server_proxy_object=self.mandos_serv,
                proxy_object=client_proxy_object,
                properties=client,
                update_hook=self.refresh,
                delete_hook=self.remove_client),
                            path=path)

        self.refresh()
        self._input_callback_tag = (
            GLib.io_add_watch(
                GLib.IOChannel.unix_new(sys.stdin.fileno()),
                GLib.PRIORITY_DEFAULT, GLib.IO_IN,
                glib_safely(self.process_input)))
        self.main_loop.run()
        # Main loop has finished, we should close everything now
        GLib.source_remove(self._input_callback_tag)
        with warnings.catch_warnings():
            warnings.simplefilter("ignore", BytesWarning)
            self.screen.stop()

    def stop(self):
        self.main_loop.quit()
        log.removeHandler(self.loghandler)
        log.propagate = self.orig_log_propagate

    def process_input(self, source, condition):
        keys = self.screen.get_input()
        translations = {"ctrl n": "down",       # Emacs
                        "ctrl p": "up",         # Emacs
                        "ctrl v": "page down",  # Emacs
                        "meta v": "page up",    # Emacs
                        " ": "page down",       # less
                        "f": "page down",       # less
                        "b": "page up",         # less
                        "j": "down",            # vi
                        "k": "up",              # vi
                        }
        for key in keys:
            try:
                key = translations[key]
            except KeyError:    # :-)
                pass

            if key == "q" or key == "Q":
                self.stop()
                break
            elif key == "window resize":
                self.size = self.screen.get_cols_rows()
                self.refresh()
            elif key == "ctrl l":
                self.screen.clear()
                self.refresh()
            elif key == "l" or key == "D":
                self.toggle_log_display()
                self.refresh()
            elif key == "w" or key == "i":
                self.change_log_display()
                self.refresh()
            elif key == "?" or key == "f1" or key == "esc":
                if not self.log_visible:
                    self.log_visible = True
                    self.rebuild()
                self.add_log_line(("bold",
                                   "  ".join(("q: Quit",
                                              "?: Help",
                                              "l: Log window toggle",
                                              "TAB: Switch window",
                                              "w: Wrap (log lines)",
                                              "v: Toggle verbose log",
                                   ))))
                self.add_log_line(("bold",
                                   "  ".join(("Clients:",
                                              "+: Enable",
                                              "-: Disable",
                                              "R: Remove",
                                              "s: Start new checker",
                                              "S: Stop checker",
                                              "C: Checker OK",
                                              "a: Approve",
                                              "d: Deny",
                                   ))))
                self.refresh()
            elif key == "tab":
                if self.topwidget.get_focus() is self.logbox:
                    self.topwidget.set_focus(0)
                else:
                    self.topwidget.set_focus(self.logbox)
                self.refresh()
            elif key == "v":
                if log.level < logging.INFO:
                    log.setLevel(logging.INFO)
                    log.info("Verbose mode: Off")
                else:
                    log.setLevel(logging.NOTSET)
                    log.info("Verbose mode: On")
            # elif (key == "end" or key == "meta >" or key == "G"
            #       or key == ">"):
            #     pass            # xxx end-of-buffer
            # elif (key == "home" or key == "meta <" or key == "g"
            #       or key == "<"):
            #     pass            # xxx beginning-of-buffer
            # elif key == "ctrl e" or key == "$":
            #     pass            # xxx move-end-of-line
            # elif key == "ctrl a" or key == "^":
            #     pass            # xxx move-beginning-of-line
            # elif key == "ctrl b" or key == "meta (" or key == "h":
            #     pass            # xxx left
            # elif key == "ctrl f" or key == "meta )" or key == "l":
            #     pass            # xxx right
            # elif key == "a":
            #     pass            # scroll up log
            # elif key == "z":
            #     pass            # scroll down log
            elif self.topwidget.selectable():
                self.topwidget.keypress(self.size, key)
                self.refresh()
        return True


class UILogHandler(logging.Handler):
    def __init__(self, ui, *args, **kwargs):
        self.ui = ui
        super(UILogHandler, self).__init__(*args, **kwargs)
        self.setFormatter(
            logging.Formatter("%(asctime)s: %(message)s"))
    def emit(self, record):
        msg = self.format(record)
        if record.levelno > logging.INFO:
            msg = ("bold", msg)
        self.ui.add_log_line(msg)


ui = UserInterface()
try:
    ui.run()
except KeyboardInterrupt:
    with warnings.catch_warnings():
        warnings.filterwarnings("ignore", "", BytesWarning)
        ui.screen.stop()
except Exception:
    with warnings.catch_warnings():
        warnings.filterwarnings("ignore", "", BytesWarning)
        ui.screen.stop()
    raise