Current File : //lib/python3/dist-packages/twisted/conch/test/test_channel.py
# Copyright Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Test ssh/channel.py.
"""
from __future__ import annotations
from unittest import skipIf
from zope.interface.verify import verifyObject
try:
from twisted.conch.ssh import channel
from twisted.conch.ssh.address import SSHTransportAddress
from twisted.conch.ssh.service import SSHService
from twisted.conch.ssh.transport import SSHServerTransport
from twisted.internet import interfaces
from twisted.internet.address import IPv4Address
from twisted.internet.testing import StringTransport
skipTest = ""
except ImportError:
skipTest = "Conch SSH not supported."
SSHService = object # type: ignore[assignment,misc]
from twisted.trial.unittest import TestCase
class MockConnection(SSHService):
"""
A mock for twisted.conch.ssh.connection.SSHConnection. Record the data
that channels send, and when they try to close the connection.
@ivar data: a L{dict} mapping channel id #s to lists of data sent by that
channel.
@ivar extData: a L{dict} mapping channel id #s to lists of 2-tuples
(extended data type, data) sent by that channel.
@ivar closes: a L{dict} mapping channel id #s to True if that channel sent
a close message.
"""
def __init__(self) -> None:
self.data: dict[channel.SSHChannel, list[bytes]] = {}
self.extData: dict[channel.SSHChannel, list[tuple[int, bytes]]] = {}
self.closes: dict[channel.SSHChannel, bool] = {}
def logPrefix(self) -> str:
"""
Return our logging prefix.
"""
return "MockConnection"
def sendData(self, channel: channel.SSHChannel, data: bytes) -> None:
"""
Record the sent data.
"""
self.data.setdefault(channel, []).append(data)
def sendExtendedData(
self, channel: channel.SSHChannel, type: int, data: bytes
) -> None:
"""
Record the sent extended data.
"""
self.extData.setdefault(channel, []).append((type, data))
def sendClose(self, channel: channel.SSHChannel) -> None:
"""
Record that the channel sent a close message.
"""
self.closes[channel] = True
def connectSSHTransport(
service: SSHService,
hostAddress: interfaces.IAddress | None = None,
peerAddress: interfaces.IAddress | None = None,
) -> None:
"""
Connect a SSHTransport which is already connected to a remote peer to
the channel under test.
@param service: Service used over the connected transport.
@type service: L{SSHService}
@param hostAddress: Local address of the connected transport.
@type hostAddress: L{interfaces.IAddress}
@param peerAddress: Remote address of the connected transport.
@type peerAddress: L{interfaces.IAddress}
"""
transport = SSHServerTransport()
transport.makeConnection(
StringTransport(hostAddress=hostAddress, peerAddress=peerAddress)
)
transport.setService(service)
@skipIf(skipTest, skipTest)
class ChannelTests(TestCase):
"""
Tests for L{SSHChannel}.
"""
def setUp(self) -> None:
"""
Initialize the channel. remoteMaxPacket is 10 so that data is able
to be sent (the default of 0 means no data is sent because no packets
are made).
"""
self.conn = MockConnection()
self.channel = channel.SSHChannel(conn=self.conn, remoteMaxPacket=10)
self.channel.name = b"channel"
def test_interface(self) -> None:
"""
L{SSHChannel} instances provide L{interfaces.ITransport}.
"""
self.assertTrue(verifyObject(interfaces.ITransport, self.channel))
def test_init(self) -> None:
"""
Test that SSHChannel initializes correctly. localWindowSize defaults
to 131072 (2**17) and localMaxPacket to 32768 (2**15) as reasonable
defaults (what OpenSSH uses for those variables).
The values in the second set of assertions are meaningless; they serve
only to verify that the instance variables are assigned in the correct
order.
"""
c = channel.SSHChannel(conn=self.conn)
self.assertEqual(c.localWindowSize, 131072)
self.assertEqual(c.localWindowLeft, 131072)
self.assertEqual(c.localMaxPacket, 32768)
self.assertEqual(c.remoteWindowLeft, 0)
self.assertEqual(c.remoteMaxPacket, 0)
self.assertEqual(c.conn, self.conn)
self.assertIsNone(c.data)
self.assertIsNone(c.avatar)
c2 = channel.SSHChannel(1, 2, 3, 4, 5, 6, 7)
self.assertEqual(c2.localWindowSize, 1)
self.assertEqual(c2.localWindowLeft, 1)
self.assertEqual(c2.localMaxPacket, 2)
self.assertEqual(c2.remoteWindowLeft, 3)
self.assertEqual(c2.remoteMaxPacket, 4)
self.assertEqual(c2.conn, 5)
self.assertEqual(c2.data, 6)
self.assertEqual(c2.avatar, 7)
def test_str(self) -> None:
"""
Test that str(SSHChannel) works gives the channel name and local and
remote windows at a glance..
"""
self.assertEqual(str(self.channel), "<SSHChannel channel (lw 131072 rw 0)>")
self.assertEqual(
str(channel.SSHChannel(localWindow=1)), "<SSHChannel None (lw 1 rw 0)>"
)
def test_bytes(self) -> None:
"""
Test that bytes(SSHChannel) works, gives the channel name and
local and remote windows at a glance..
"""
self.assertEqual(
self.channel.__bytes__(), b"<SSHChannel channel (lw 131072 rw 0)>"
)
self.assertEqual(
channel.SSHChannel(localWindow=1).__bytes__(),
b"<SSHChannel None (lw 1 rw 0)>",
)
def test_logPrefix(self) -> None:
"""
Test that SSHChannel.logPrefix gives the name of the channel, the
local channel ID and the underlying connection.
"""
self.assertEqual(
self.channel.logPrefix(), "SSHChannel channel (unknown) on MockConnection"
)
def test_addWindowBytes(self) -> None:
"""
Test that addWindowBytes adds bytes to the window and resumes writing
if it was paused.
"""
cb = [False]
def stubStartWriting() -> None:
cb[0] = True
self.channel.startWriting = stubStartWriting # type: ignore[method-assign]
self.channel.write(b"test")
self.channel.writeExtended(1, b"test")
self.channel.addWindowBytes(50)
self.assertEqual(self.channel.remoteWindowLeft, 50 - 4 - 4)
self.assertTrue(self.channel.areWriting)
self.assertTrue(cb[0])
self.assertEqual(self.channel.buf, b"")
self.assertEqual(self.conn.data[self.channel], [b"test"])
self.assertEqual(self.channel.extBuf, [])
self.assertEqual(self.conn.extData[self.channel], [(1, b"test")])
cb[0] = False
self.channel.addWindowBytes(20)
self.assertFalse(cb[0])
self.channel.write(b"a" * 80)
self.channel.loseConnection()
self.channel.addWindowBytes(20)
self.assertFalse(cb[0])
def test_requestReceived(self) -> None:
"""
Test that requestReceived handles requests by dispatching them to
request_* methods.
"""
self.channel.request_test_method = lambda data: data == b"" # type: ignore[attr-defined]
self.assertTrue(self.channel.requestReceived(b"test-method", b""))
self.assertFalse(self.channel.requestReceived(b"test-method", b"a"))
self.assertFalse(self.channel.requestReceived(b"bad-method", b""))
def test_closeReceieved(self) -> None:
"""
Test that the default closeReceieved closes the connection.
"""
self.assertFalse(self.channel.closing)
self.channel.closeReceived()
self.assertTrue(self.channel.closing)
def test_write(self) -> None:
"""
Test that write handles data correctly. Send data up to the size
of the remote window, splitting the data into packets of length
remoteMaxPacket.
"""
cb = [False]
def stubStopWriting() -> None:
cb[0] = True
# no window to start with
self.channel.stopWriting = stubStopWriting # type: ignore[method-assign]
self.channel.write(b"d")
self.channel.write(b"a")
self.assertFalse(self.channel.areWriting)
self.assertTrue(cb[0])
# regular write
self.channel.addWindowBytes(20)
self.channel.write(b"ta")
data = self.conn.data[self.channel]
self.assertEqual(data, [b"da", b"ta"])
self.assertEqual(self.channel.remoteWindowLeft, 16)
# larger than max packet
self.channel.write(b"12345678901")
self.assertEqual(data, [b"da", b"ta", b"1234567890", b"1"])
self.assertEqual(self.channel.remoteWindowLeft, 5)
# running out of window
cb[0] = False
self.channel.write(b"123456")
self.assertFalse(self.channel.areWriting)
self.assertTrue(cb[0])
self.assertEqual(data, [b"da", b"ta", b"1234567890", b"1", b"12345"])
self.assertEqual(self.channel.buf, b"6")
self.assertEqual(self.channel.remoteWindowLeft, 0)
def test_writeExtended(self) -> None:
"""
Test that writeExtended handles data correctly. Send extended data
up to the size of the window, splitting the extended data into packets
of length remoteMaxPacket.
"""
cb = [False]
def stubStopWriting() -> None:
cb[0] = True
# no window to start with
self.channel.stopWriting = stubStopWriting # type: ignore[method-assign]
self.channel.writeExtended(1, b"d")
self.channel.writeExtended(1, b"a")
self.channel.writeExtended(2, b"t")
self.assertFalse(self.channel.areWriting)
self.assertTrue(cb[0])
# regular write
self.channel.addWindowBytes(20)
self.channel.writeExtended(2, b"a")
data = self.conn.extData[self.channel]
self.assertEqual(data, [(1, b"da"), (2, b"t"), (2, b"a")])
self.assertEqual(self.channel.remoteWindowLeft, 16)
# larger than max packet
self.channel.writeExtended(3, b"12345678901")
self.assertEqual(
data, [(1, b"da"), (2, b"t"), (2, b"a"), (3, b"1234567890"), (3, b"1")]
)
self.assertEqual(self.channel.remoteWindowLeft, 5)
# running out of window
cb[0] = False
self.channel.writeExtended(4, b"123456")
self.assertFalse(self.channel.areWriting)
self.assertTrue(cb[0])
self.assertEqual(
data,
[
(1, b"da"),
(2, b"t"),
(2, b"a"),
(3, b"1234567890"),
(3, b"1"),
(4, b"12345"),
],
)
self.assertEqual(self.channel.extBuf, [[4, b"6"]])
self.assertEqual(self.channel.remoteWindowLeft, 0)
def test_writeSequence(self) -> None:
"""
Test that writeSequence is equivalent to write(''.join(sequece)).
"""
self.channel.addWindowBytes(20)
self.channel.writeSequence(b"%d" % (i,) for i in range(10))
self.assertEqual(self.conn.data[self.channel], [b"0123456789"])
def test_loseConnection(self) -> None:
"""
Tesyt that loseConnection() doesn't close the channel until all
the data is sent.
"""
self.channel.write(b"data")
self.channel.writeExtended(1, b"datadata")
self.channel.loseConnection()
self.assertIsNone(self.conn.closes.get(self.channel))
self.channel.addWindowBytes(4) # send regular data
self.assertIsNone(self.conn.closes.get(self.channel))
self.channel.addWindowBytes(8) # send extended data
self.assertTrue(self.conn.closes.get(self.channel))
def test_getPeer(self) -> None:
"""
L{SSHChannel.getPeer} returns the same object as the underlying
transport's C{getPeer} method returns.
"""
peer = IPv4Address("TCP", "192.168.0.1", 54321)
connectSSHTransport(service=self.channel.conn, peerAddress=peer)
self.assertEqual(SSHTransportAddress(peer), self.channel.getPeer())
def test_getHost(self) -> None:
"""
L{SSHChannel.getHost} returns the same object as the underlying
transport's C{getHost} method returns.
"""
host = IPv4Address("TCP", "127.0.0.1", 12345)
connectSSHTransport(service=self.channel.conn, hostAddress=host)
self.assertEqual(SSHTransportAddress(host), self.channel.getHost())
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