gvm.connections.DebugConnection.disconnect() - Code Metrics - Inspection of "Merge pull request #44 from bjoernricks/connection..." - greenbone/python-gvm - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 308939...624384 )

by Juan José

created 2018-11-12 14:45 UTC

gvm.connections.DebugConnection.disconnect() A

↳ Parent: gvm.connections

Complexity

Conditions

Size

Total Lines	4
Code Lines	3

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	1
eloc	3
nop	1
dl	0
loc	4
rs	10
c	0
b	0
f	0

# -*- coding: utf-8 -*-
# Copyright (C) 2018 Greenbone Networks GmbH
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
# 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/>.
"""
Module for connections to GVM server daemons like gvmd and ospd.
"""
import logging
import socket as socketlib
import ssl
import time

import paramiko

from lxml import etree

from gvm.errors import GvmError


logger = logging.getLogger(__name__)

BUF_SIZE = 1024
DEFAULT_READ_TIMEOUT = 60 # in seconds
DEFAULT_TIMEOUT = 60 # in seconds
DEFAULT_GVM_PORT = 9390
DEFAULT_UNIX_SOCKET_PATH = '/usr/local/var/run/gvmd.sock'
MAX_SSH_DATA_LENGTH = 4095

class XmlReader:
    """
    Read a XML command until its closing element
    """

    def _start_xml(self):
        self._first_element = None
        self._parser = etree.XMLPullParser(('start', 'end'))

    def _is_end_xml(self):
        for action, obj in self._parser.read_events():
            if not self._first_element and action in 'start':
                self._first_element = obj.tag

            if self._first_element and action in 'end' and \
                    str(self._first_element) == str(obj.tag):
                return True
        return False

    def _feed_xml(self, data):
        try:
            self._parser.feed(data)
        except etree.ParseError as e:
            raise GvmError("Can't parse xml response. Response data "
                           "read {0}".format(data), e)


class GvmConnection(XmlReader):
    """
    Base class for establishing a connection to a remote server daemon.

    Arguments:
        timeout (int, optional): Timeout in seconds for the connection.
    """

    def __init__(self, timeout=DEFAULT_TIMEOUT):
        self._socket = None
        self._timeout = timeout

    def _read(self):
        return self._socket.recv(BUF_SIZE)

    def connect(self):
        """Establish a connection to a remote server
        """
        raise NotImplementedError

    def send(self, data):
        """Send data to the connected remote server

        Arguments:
            data (str or bytes): Data to be send to the server. Either utf-8
                encoded string or bytes.
        """
        if isinstance(data, str):
            self._socket.sendall(data.encode())
        else:
            self._socket.sendall(data)

    def read(self):
        """Read data from the remote server

        Returns:
            str: data as utf-8 encoded string
        """
        response = ''

        self._start_xml()

        now = time.time()

        break_timeout = now + self._timeout

        while True:
            data = self._read()

            if not data:
                # Connection was closed by server
                raise GvmError('Remote closed the connection')

            self._feed_xml(data)

            response += data.decode('utf-8', errors='ignore')

            if self._is_end_xml():
                break

            now = time.time()

            if now > break_timeout:
                raise GvmError('Timeout while reading the response')

        return response

    def disconnect(self):
        """Disconnect and close the connection to the remote server
        """
        try:
            if self._socket is not None:
                self._socket.close()
        except OSError as e:
            logger.debug('Connection closing error: %s', e)


class SSHConnection(GvmConnection):
    """
    SSH Class to connect, read and write from GVM via SSH

    Arguments:
        timeout (int, optional): Timeout in seconds for the connection.
        hostname (str, optional): DNS name or IP address of the remote server.
            Default is 127.0.0.1.
        port (int, optional): Port of the remote SSH server.
        username (str, optional): Username to use for SSH login.
        password (str, optional): Passwort to use for SSH login.
    """

    def __init__(self, timeout=DEFAULT_TIMEOUT, hostname='127.0.0.1', port=22,
                 username='gmp', password=''):
        super().__init__(timeout=timeout)

        self.hostname = hostname
        self.port = int(port)
        self.username = username
        self.password = password

    def _send_in_chunks(self, data, chunk_size):
        i_start = 0
        i_end = chunk_size
        sent_bytes = 0
        length = len(data)

        while sent_bytes < length:
            time.sleep(0.01)

            self._stdin.channel.send(data[i_start:i_end])

            i_start = i_end
            if i_end > length:
                i_end = length
            else:
                i_end = i_end + chunk_size

            sent_bytes += (i_end - i_start)

        return sent_bytes

    def connect(self):
        """
        Connect to the SSH server and authenticate to it
        """
        self._socket = paramiko.SSHClient()
        self._socket.set_missing_host_key_policy(paramiko.AutoAddPolicy())

        try:
            self._socket.connect(
                hostname=self.hostname,
                username=self.username,
                password=self.password,
                timeout=self._timeout,
                port=int(self.port),
                allow_agent=False,
                look_for_keys=False)
            self._stdin, self._stdout, self._stderr = self._socket.exec_command(
                "", get_pty=False)

        except (paramiko.BadHostKeyException,
                paramiko.AuthenticationException,
                paramiko.SSHException,
                ) as e:
            raise GvmError('SSH Connection failed', e)

    def _read(self):
        return self._stdout.channel.recv(BUF_SIZE)

    def send(self, data):
        if len(data) > MAX_SSH_DATA_LENGTH:
            self._send_in_chunks(data, MAX_SSH_DATA_LENGTH)
        else:
            self._stdin.channel.send(data)


class TLSConnection(GvmConnection):
    """
    TLS class to connect, read and write from a remote GVM daemon via TLS
    secured socket.

    Arguments:
        timeout (int, optional): Timeout in seconds for the connection.
        hostname (str, optional): DNS name or IP address of the remote TLS
            server.
        port (str, optional): Port for the TLS connection. Default is 9390.
        certfile (str, optional): Path to PEM encoded certificate file. See
            `python certificates`_ for details.
        cafile (str, optional): Path to PEM encoded CA file. See
            `python certificates`_ for details.
        keyfile (str, optional): Path to PEM encoded private key. See
            `python certificates`_ for details.
        password (str, optional): Password for the private key. If the password
            argument is not specified and a password is required it will be
            interactively prompt the user for a password.

    .. _python certificates:
        https://docs.python.org/3.5/library/ssl.html#certificates
    """

    def __init__(self, certfile=None, cafile=None, keyfile=None,
                 hostname='127.0.0.1', port=DEFAULT_GVM_PORT, password=None,
                 timeout=DEFAULT_TIMEOUT):
        super().__init__(timeout=timeout)

        self.hostname = hostname
        self.port = port
        self.certfile = certfile
        self.cafile = cafile
        self.keyfile = keyfile
        self.password = password

    def _new_socket(self):
        transport_socket = socketlib.socket(socketlib.AF_INET,
                                            socketlib.SOCK_STREAM)

        if self.certfile and self.cafile and self.keyfile:
            context = ssl.create_default_context(ssl.Purpose.SERVER_AUTH,
                                                 cafile=self.cafile)
            context.check_hostname = False
            context.load_cert_chain(
                certfile=self.certfile, keyfile=self.keyfile,
                password=self.password)
            sock = context.wrap_socket(transport_socket, server_side=False)
        else:
            context = ssl.SSLContext(ssl.PROTOCOL_TLSv1_2)
            sock = context.wrap_socket(transport_socket)

        sock.settimeout(self._timeout)

        return sock

    def connect(self):
        self._socket = self._new_socket()
        self._socket.connect((self.hostname, int(self.port)))


class UnixSocketConnection(GvmConnection):
    """
    UNIX-Socket class to connect, read, write from a GVM server daemon via
    direct communicating UNIX-Socket

    Arguments:
        path (str, optional): Path to the socket.
        timeout (int, optional): Timeout in seconds for the connection.
    """

    def __init__(self, path=DEFAULT_UNIX_SOCKET_PATH, timeout=DEFAULT_TIMEOUT,
                 read_timeout=DEFAULT_READ_TIMEOUT):
        super().__init__(timeout=timeout)

        self.read_timeout = read_timeout
        self.path = path

    def connect(self):
        """Connect to the UNIX socket
        """
        self._socket = socketlib.socket(
            socketlib.AF_UNIX, socketlib.SOCK_STREAM)
        self._socket.settimeout(self._timeout)
        self._socket.connect(self.path)


class DebugConnection:

    def __init__(self, connection):
        self._connection = connection

    def read(self):
        data = self._connection.read()

        logger.debug('Read %s characters. Data %s', len(data), data)

        self.last_read_data = data
        return data

    def send(self, data):
        self.last_send_data = data

        logger.debug('Sending %s characters. Data %s', len(data), data)

        return self._connection.send(data)

    def connect(self):
        logger.debug('Connecting')

        return self._connection.connect()

    def disconnect(self):
        logger.debug('Disconnecting')

        return self._connection.disconnect()


1			# -- coding: utf-8 --
2			# Copyright (C) 2018 Greenbone Networks GmbH
3			#
4			# SPDX-License-Identifier: GPL-3.0-or-later
5			#
6			# This program is free software: you can redistribute it and/or modify
7			# it under the terms of the GNU General Public License as published by
8			# the Free Software Foundation, either version 3 of the License, or
9			# (at your option) any later version.
10			#
11			# This program is distributed in the hope that it will be useful,
12			# but WITHOUT ANY WARRANTY; without even the implied warranty of
13			# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			# GNU General Public License for more details.
15			#
16			# You should have received a copy of the GNU General Public License
17			# along with this program. If not, see <http://www.gnu.org/licenses/>.
18			"""
19			Module for connections to GVM server daemons like gvmd and ospd.
20			"""
21			import logging
22			import socket as socketlib
23			import ssl
24			import time
25
26			import paramiko
27
28			from lxml import etree
29
30			from gvm.errors import GvmError
31
32
33			logger = logging.getLogger(__name__)
34
35			BUF_SIZE = 1024
36			DEFAULT_READ_TIMEOUT = 60 # in seconds
37			DEFAULT_TIMEOUT = 60 # in seconds
38			DEFAULT_GVM_PORT = 9390
39			DEFAULT_UNIX_SOCKET_PATH = '/usr/local/var/run/gvmd.sock'
40			MAX_SSH_DATA_LENGTH = 4095
41
42			class XmlReader:
43			"""
44			Read a XML command until its closing element
45			"""
46
47			def _start_xml(self):
48			self._first_element = None
49			self._parser = etree.XMLPullParser(('start', 'end'))
50
51			def _is_end_xml(self):
52			for action, obj in self._parser.read_events():
53			if not self._first_element and action in 'start':
54			self._first_element = obj.tag
55
56			if self._first_element and action in 'end' and \
57			str(self._first_element) == str(obj.tag):
58			return True
59			return False
60
61			def _feed_xml(self, data):
62			try:
63			self._parser.feed(data)
64			except etree.ParseError as e:
65			raise GvmError("Can't parse xml response. Response data "
66			"read {0}".format(data), e)
67
68
69			class GvmConnection(XmlReader):
70			"""
71			Base class for establishing a connection to a remote server daemon.
72
73			Arguments:
74			timeout (int, optional): Timeout in seconds for the connection.
75			"""
76
77			def __init__(self, timeout=DEFAULT_TIMEOUT):
78			self._socket = None
79			self._timeout = timeout
80
81			def _read(self):
82			return self._socket.recv(BUF_SIZE)
83
84			def connect(self):
85			"""Establish a connection to a remote server
86			"""
87			raise NotImplementedError
88
89			def send(self, data):
90			"""Send data to the connected remote server
91
92			Arguments:
93			data (str or bytes): Data to be send to the server. Either utf-8
94			encoded string or bytes.
95			"""
96			if isinstance(data, str):
97			self._socket.sendall(data.encode())
98			else:
99			self._socket.sendall(data)
100
101			def read(self):
102			"""Read data from the remote server
103
104			Returns:
105			str: data as utf-8 encoded string
106			"""
107			response = ''
108
109			self._start_xml()
110
111			now = time.time()
112
113			break_timeout = now + self._timeout
114
115			while True:
116			data = self._read()
117
118			if not data:
119			# Connection was closed by server
120			raise GvmError('Remote closed the connection')
121
122			self._feed_xml(data)
123
124			response += data.decode('utf-8', errors='ignore')
125
126			if self._is_end_xml():
127			break
128
129			now = time.time()
130
131			if now > break_timeout:
132			raise GvmError('Timeout while reading the response')
133
134			return response
135
136			def disconnect(self):
137			"""Disconnect and close the connection to the remote server
138			"""
139			try:
140			if self._socket is not None:
141			self._socket.close()
142			except OSError as e:
143			logger.debug('Connection closing error: %s', e)
144
145
146			class SSHConnection(GvmConnection):
147			"""
148			SSH Class to connect, read and write from GVM via SSH
149
150			Arguments:
151			timeout (int, optional): Timeout in seconds for the connection.
152			hostname (str, optional): DNS name or IP address of the remote server.
153			Default is 127.0.0.1.
154			port (int, optional): Port of the remote SSH server.
155			username (str, optional): Username to use for SSH login.
156			password (str, optional): Passwort to use for SSH login.
157			"""
158
159			def __init__(self, timeout=DEFAULT_TIMEOUT, hostname='127.0.0.1', port=22,
160			username='gmp', password=''):
161			super().__init__(timeout=timeout)
162
163			self.hostname = hostname
164			self.port = int(port)
165			self.username = username
166			self.password = password
167
168			def _send_in_chunks(self, data, chunk_size):
169			i_start = 0
170			i_end = chunk_size
171			sent_bytes = 0
172			length = len(data)
173
174			while sent_bytes < length:
175			time.sleep(0.01)
176
177			self._stdin.channel.send(data[i_start:i_end])
178
179			i_start = i_end
180			if i_end > length:
181			i_end = length
182			else:
183			i_end = i_end + chunk_size
184
185			sent_bytes += (i_end - i_start)
186
187			return sent_bytes
188
189			def connect(self):
190			"""
191			Connect to the SSH server and authenticate to it
192			"""
193			self._socket = paramiko.SSHClient()
194			self._socket.set_missing_host_key_policy(paramiko.AutoAddPolicy())
195
196			try:
197			self._socket.connect(
198			hostname=self.hostname,
199			username=self.username,
200			password=self.password,
201			timeout=self._timeout,
202			port=int(self.port),
203			allow_agent=False,
204			look_for_keys=False)
205			self._stdin, self._stdout, self._stderr = self._socket.exec_command(
206			"", get_pty=False)
207
208			except (paramiko.BadHostKeyException,
209			paramiko.AuthenticationException,
210			paramiko.SSHException,
211			) as e:
212			raise GvmError('SSH Connection failed', e)
213
214			def _read(self):
215			return self._stdout.channel.recv(BUF_SIZE)
216
217			def send(self, data):
218			if len(data) > MAX_SSH_DATA_LENGTH:
219			self._send_in_chunks(data, MAX_SSH_DATA_LENGTH)
220			else:
221			self._stdin.channel.send(data)
222
223
224			class TLSConnection(GvmConnection):
225			"""
226			TLS class to connect, read and write from a remote GVM daemon via TLS
227			secured socket.
228
229			Arguments:
230			timeout (int, optional): Timeout in seconds for the connection.
231			hostname (str, optional): DNS name or IP address of the remote TLS
232			server.
233			port (str, optional): Port for the TLS connection. Default is 9390.
234			certfile (str, optional): Path to PEM encoded certificate file. See
235			`python certificates`_ for details.
236			cafile (str, optional): Path to PEM encoded CA file. See
237			`python certificates`_ for details.
238			keyfile (str, optional): Path to PEM encoded private key. See
239			`python certificates`_ for details.
240			password (str, optional): Password for the private key. If the password
241			argument is not specified and a password is required it will be
242			interactively prompt the user for a password.
243
244			.. _python certificates:
245			https://docs.python.org/3.5/library/ssl.html#certificates
246			"""
247
248			def __init__(self, certfile=None, cafile=None, keyfile=None,
249			hostname='127.0.0.1', port=DEFAULT_GVM_PORT, password=None,
250			timeout=DEFAULT_TIMEOUT):
251			super().__init__(timeout=timeout)
252
253			self.hostname = hostname
254			self.port = port
255			self.certfile = certfile
256			self.cafile = cafile
257			self.keyfile = keyfile
258			self.password = password
259
260			def _new_socket(self):
261			transport_socket = socketlib.socket(socketlib.AF_INET,
262			socketlib.SOCK_STREAM)
263
264			if self.certfile and self.cafile and self.keyfile:
265			context = ssl.create_default_context(ssl.Purpose.SERVER_AUTH,
266			cafile=self.cafile)
267			context.check_hostname = False
268			context.load_cert_chain(
269			certfile=self.certfile, keyfile=self.keyfile,
270			password=self.password)
271			sock = context.wrap_socket(transport_socket, server_side=False)
272			else:
273			context = ssl.SSLContext(ssl.PROTOCOL_TLSv1_2)
274			sock = context.wrap_socket(transport_socket)
275
276			sock.settimeout(self._timeout)
277
278			return sock
279
280			def connect(self):
281			self._socket = self._new_socket()
282			self._socket.connect((self.hostname, int(self.port)))
283
284
285			class UnixSocketConnection(GvmConnection):
286			"""
287			UNIX-Socket class to connect, read, write from a GVM server daemon via
288			direct communicating UNIX-Socket
289
290			Arguments:
291			path (str, optional): Path to the socket.
292			timeout (int, optional): Timeout in seconds for the connection.
293			"""
294
295			def __init__(self, path=DEFAULT_UNIX_SOCKET_PATH, timeout=DEFAULT_TIMEOUT,
296			read_timeout=DEFAULT_READ_TIMEOUT):
297			super().__init__(timeout=timeout)
298
299			self.read_timeout = read_timeout
300			self.path = path
301
302			def connect(self):
303			"""Connect to the UNIX socket
304			"""
305			self._socket = socketlib.socket(
306			socketlib.AF_UNIX, socketlib.SOCK_STREAM)
307			self._socket.settimeout(self._timeout)
308			self._socket.connect(self.path)
309
310
311			class DebugConnection:
312
313			def __init__(self, connection):
314			self._connection = connection
315
316			def read(self):
317			data = self._connection.read()
318
319			logger.debug('Read %s characters. Data %s', len(data), data)
320
321			self.last_read_data = data
322			return data
323
324			def send(self, data):
325			self.last_send_data = data
326
327			logger.debug('Sending %s characters. Data %s', len(data), data)
328
329			return self._connection.send(data)
330
331			def connect(self):
332			logger.debug('Connecting')
333
334			return self._connection.connect()
335
336			def disconnect(self):
337			logger.debug('Disconnecting')
338
339			return self._connection.disconnect()
340

greenbone / python-gvm

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gvm.connections.DebugConnection.disconnect() A

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