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# Copyright (C) 2007-2008 Twisted Matrix Laboratories
# See LICENSE for details
"""
Test ssh/channel.py.
"""
from twisted.conch.ssh import channel
from twisted.trial import unittest
class MockTransport(object):
"""
A mock Transport. All we use is the getPeer() and getHost() methods.
Channels implement the ITransport interface, and their getPeer() and
getHost() methods return ('SSH', <transport's getPeer/Host value>) so
we need to implement these methods so they have something to draw
from.
"""
def getPeer(self):
return ('MockPeer',)
def getHost(self):
return ('MockHost',)
class MockConnection(object):
"""
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 C{dict} mapping channel id #s to lists of data sent by that
channel.
@ivar extData: a C{dict} mapping channel id #s to lists of 2-tuples
(extended data type, data) sent by that channel.
@ivar closes: a C{dict} mapping channel id #s to True if that channel sent
a close message.
"""
transport = MockTransport()
def __init__(self):
self.data = {}
self.extData = {}
self.closes = {}
def logPrefix(self):
"""
Return our logging prefix.
"""
return "MockConnection"
def sendData(self, channel, data):
"""
Record the sent data.
"""
self.data.setdefault(channel, []).append(data)
def sendExtendedData(self, channel, type, data):
"""
Record the sent extended data.
"""
self.extData.setdefault(channel, []).append((type, data))
def sendClose(self, channel):
"""
Record that the channel sent a close message.
"""
self.closes[channel] = True
class ChannelTestCase(unittest.TestCase):
def setUp(self):
"""
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 = 'channel'
def test_init(self):
"""
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.assertEquals(c.localWindowSize, 131072)
self.assertEquals(c.localWindowLeft, 131072)
self.assertEquals(c.localMaxPacket, 32768)
self.assertEquals(c.remoteWindowLeft, 0)
self.assertEquals(c.remoteMaxPacket, 0)
self.assertEquals(c.conn, self.conn)
self.assertEquals(c.data, None)
self.assertEquals(c.avatar, None)
c2 = channel.SSHChannel(1, 2, 3, 4, 5, 6, 7)
self.assertEquals(c2.localWindowSize, 1)
self.assertEquals(c2.localWindowLeft, 1)
self.assertEquals(c2.localMaxPacket, 2)
self.assertEquals(c2.remoteWindowLeft, 3)
self.assertEquals(c2.remoteMaxPacket, 4)
self.assertEquals(c2.conn, 5)
self.assertEquals(c2.data, 6)
self.assertEquals(c2.avatar, 7)
def test_str(self):
"""
Test that str(SSHChannel) works gives the channel name and local and
remote windows at a glance..
"""
self.assertEquals(str(self.channel), '<SSHChannel channel (lw 131072 '
'rw 0)>')
def test_logPrefix(self):
"""
Test that SSHChannel.logPrefix gives the name of the channel, the
local channel ID and the underlying connection.
"""
self.assertEquals(self.channel.logPrefix(), 'SSHChannel channel '
'(unknown) on MockConnection')
def test_addWindowBytes(self):
"""
Test that addWindowBytes adds bytes to the window and resumes writing
if it was paused.
"""
cb = [False]
def stubStartWriting():
cb[0] = True
self.channel.startWriting = stubStartWriting
self.channel.write('test')
self.channel.writeExtended(1, 'test')
self.channel.addWindowBytes(50)
self.assertEquals(self.channel.remoteWindowLeft, 50 - 4 - 4)
self.assertTrue(self.channel.areWriting)
self.assertTrue(cb[0])
self.assertEquals(self.channel.buf, '')
self.assertEquals(self.conn.data[self.channel], ['test'])
self.assertEquals(self.channel.extBuf, [])
self.assertEquals(self.conn.extData[self.channel], [(1, 'test')])
cb[0] = False
self.channel.addWindowBytes(20)
self.assertFalse(cb[0])
self.channel.write('a'*80)
self.channel.loseConnection()
self.channel.addWindowBytes(20)
self.assertFalse(cb[0])
def test_requestReceived(self):
"""
Test that requestReceived handles requests by dispatching them to
request_* methods.
"""
self.channel.request_test_method = lambda data: data == ''
self.assertTrue(self.channel.requestReceived('test-method', ''))
self.assertFalse(self.channel.requestReceived('test-method', 'a'))
self.assertFalse(self.channel.requestReceived('bad-method', ''))
def test_closeReceieved(self):
"""
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):
"""
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():
cb[0] = True
# no window to start with
self.channel.stopWriting = stubStopWriting
self.channel.write('d')
self.channel.write('a')
self.assertFalse(self.channel.areWriting)
self.assertTrue(cb[0])
# regular write
self.channel.addWindowBytes(20)
self.channel.write('ta')
data = self.conn.data[self.channel]
self.assertEquals(data, ['da', 'ta'])
self.assertEquals(self.channel.remoteWindowLeft, 16)
# larger than max packet
self.channel.write('12345678901')
self.assertEquals(data, ['da', 'ta', '1234567890', '1'])
self.assertEquals(self.channel.remoteWindowLeft, 5)
# running out of window
cb[0] = False
self.channel.write('123456')
self.assertFalse(self.channel.areWriting)
self.assertTrue(cb[0])
self.assertEquals(data, ['da', 'ta', '1234567890', '1', '12345'])
self.assertEquals(self.channel.buf, '6')
self.assertEquals(self.channel.remoteWindowLeft, 0)
def test_writeExtended(self):
"""
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():
cb[0] = True
# no window to start with
self.channel.stopWriting = stubStopWriting
self.channel.writeExtended(1, 'd')
self.channel.writeExtended(1, 'a')
self.channel.writeExtended(2, 't')
self.assertFalse(self.channel.areWriting)
self.assertTrue(cb[0])
# regular write
self.channel.addWindowBytes(20)
self.channel.writeExtended(2, 'a')
data = self.conn.extData[self.channel]
self.assertEquals(data, [(1, 'da'), (2, 't'), (2, 'a')])
self.assertEquals(self.channel.remoteWindowLeft, 16)
# larger than max packet
self.channel.writeExtended(3, '12345678901')
self.assertEquals(data, [(1, 'da'), (2, 't'), (2, 'a'),
(3, '1234567890'), (3, '1')])
self.assertEquals(self.channel.remoteWindowLeft, 5)
# running out of window
cb[0] = False
self.channel.writeExtended(4, '123456')
self.assertFalse(self.channel.areWriting)
self.assertTrue(cb[0])
self.assertEquals(data, [(1, 'da'), (2, 't'), (2, 'a'),
(3, '1234567890'), (3, '1'), (4, '12345')])
self.assertEquals(self.channel.extBuf, [[4, '6']])
self.assertEquals(self.channel.remoteWindowLeft, 0)
def test_writeSequence(self):
"""
Test that writeSequence is equivalent to write(''.join(sequece)).
"""
self.channel.addWindowBytes(20)
self.channel.writeSequence(map(str, range(10)))
self.assertEquals(self.conn.data[self.channel], ['0123456789'])
def test_loseConnection(self):
"""
Tesyt that loseConnection() doesn't close the channel until all
the data is sent.
"""
self.channel.write('data')
self.channel.writeExtended(1, 'datadata')
self.channel.loseConnection()
self.assertEquals(self.conn.closes.get(self.channel), None)
self.channel.addWindowBytes(4) # send regular data
self.assertEquals(self.conn.closes.get(self.channel), None)
self.channel.addWindowBytes(8) # send extended data
self.assertTrue(self.conn.closes.get(self.channel))
def test_getPeer(self):
"""
Test that getPeer() returns ('SSH', <connection transport peer>).
"""
self.assertEquals(self.channel.getPeer(), ('SSH', 'MockPeer'))
def test_getHost(self):
"""
Test that getHost() returns ('SSH', <connection transport host>).
"""
self.assertEquals(self.channel.getHost(), ('SSH', 'MockHost'))
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