view test/test_channels.py @ 1857:6022df862942

Use DSCP for IP QoS traffic classes The previous TOS values are deprecated and not used by modern traffic classifiers. This sets AF21 for "interactive" traffic (with a tty). Non-tty traffic sets AF11 - that indicates high throughput but is not lowest priority (which would be CS1 or LE). This differs from the CS1 used by OpenSSH, it lets interactive git over SSH have higher priority than background least effort traffic. Dropbear's settings here should be suitable with the diffservs used by CAKE qdisc.
author Matt Johnston <matt@ucc.asn.au>
date Tue, 25 Jan 2022 17:32:20 +0800
parents 06c7ddbb9dd6
children
line wrap: on
line source

from test_dropbear import *
import signal
import queue
import socket

# Tests for various edge cases of SSH channels and connection service

def test_exitcode(request, dropbear):
	r = dbclient(request, "exit 44")
	assert r.returncode == 44

@pytest.mark.xfail(reason="Not yet implemented", strict=True)
def test_signal(request, dropbear):
	r = dbclient(request, "kill -FPE $$")
	assert r.returncode == -signal.SIGFPE

@pytest.mark.parametrize("size", [0, 1, 2, 100, 5000, 200_000])
def test_roundtrip(request, dropbear, size):
	dat = os.urandom(size)
	r = dbclient(request, "cat", input=dat, capture_output=True)
	r.check_returncode()
	assert r.stdout == dat

@pytest.mark.parametrize("size", [0, 1, 2, 100, 20001, 41234])
def test_read_pty(request, dropbear, size):
	# testcase for
	# https://bugs.openwrt.org/index.php?do=details&task_id=1814
	# https://github.com/mkj/dropbear/pull/85
	# From Yousong Zhou
	# Fixed Oct 2021
	#
	#$ ssh -t my.router cat /tmp/bigfile | wc
	#Connection to my.router closed.
	#  0       1   14335 <- should be 20001

	# Write the file. No newlines etc which could confuse ptys
	dat = random_alnum(size)
	r = dbclient(request, "tmpf=`mktemp`; echo $tmpf; cat > $tmpf", input=dat, capture_output=True, text=True)
	tmpf = r.stdout.rstrip()
	r.check_returncode()
	# Read with a pty, this is what is being tested.
	# Timing/buffering is subtle, we seem to need to cat a file from disk to hit it.
	m, s = pty.openpty()
	r = dbclient(request, "-t", f"cat {tmpf}; rm {tmpf}", stdin=s, capture_output=True)
	r.check_returncode()
	assert r.stdout.decode() == dat

@pytest.mark.parametrize("fd", [1, 2])
def test_bg_sleep(request, fd, dropbear):
	# https://lists.ucc.asn.au/pipermail/dropbear/2006q1/000362.html
	# Rob Landley "Is this a bug?" 24 Mar 2006
	# dbclient user@system "sleep 10& echo hello"
	#
	# It should return right after printing hello, but it doesn't.  It waits until
	# the child process exits.

	# failure is TimeoutExpired
	redir = "" if fd == 1 else " >&2 "
	r = dbclient(request, f"sleep 10& echo hello {redir}",
		capture_output=True, timeout=2, text=True)
	r.check_returncode()
	st = r.stdout if fd == 1 else r.stderr

	if fd == 2 and 'accepted unconditionally' in st:
		# ignore hostkey warning, a bit of a hack
		assert st.endswith("\n\nhello\n")
	else:
		assert st.rstrip() == "hello"


def test_idle(request, dropbear):
	# Idle test, -I 1 should make it return before the 2 second timeout
	r = dbclient(request, "-I", "1", "echo zong; sleep 10",
		capture_output=True, timeout=2, text=True)
	r.check_returncode()
	assert r.stdout.rstrip() == "zong"

@pytest.mark.parametrize("size", [1, 4000, 40000])
def test_netcat(request, dropbear, size):
	opt = request.config.option
	if opt.remote:
		pytest.xfail("don't know netcat address for remote")

	dat1 = os.urandom(size)
	dat2 = os.urandom(size)
	with HandleTcp(3344, 1, dat2) as tcp:
		r = dbclient(request, "-B", "localhost:3344", input=dat1, capture_output=True)
		r.check_returncode()
		assert r.stdout == dat2
		assert tcp.inbound() == dat1

@pytest.mark.parametrize("size", [1, 4000, 40000])
@pytest.mark.parametrize("fwd_flag", "LR")
def test_tcpflushout(request, dropbear, size, fwd_flag):
	""" Tests that an opened TCP connection prevent a SSH session from being closed
	until that TCP connection has finished transferring
	"""
	opt = request.config.option
	if opt.remote:
		pytest.xfail("don't know address for remote")

	dat1 = os.urandom(size)
	dat2 = os.urandom(size)
	q = queue.Queue()
	with HandleTcp(3344, timeout=1, response=q) as tcp:

		r = dbclient(request, f"-{fwd_flag}", "7788:localhost:3344", "sleep 0.1; echo -n done",
			text=True, background=True, stdout=subprocess.PIPE, stderr=subprocess.DEVNULL)
		# time to let the listener start
		time.sleep(0.1)
		# open a tcp connection
		c = socket.create_connection(("localhost", 7788))

		# wait for the shell to finish. sleep a bit longer in case it exits.
		assert r.stdout.read(4) == "done"
		time.sleep(0.1)

		# now the shell has finished, we can write on the tcp socket
		c.sendall(dat2)
		c.shutdown(socket.SHUT_WR)
		q.put(dat1)

		# return a tcp response
		q.put(None)
		# check hasn't exited
		assert r.poll() == None

		# read the response
		assert readall_socket(c) == dat1
		c.close()
		assert tcp.inbound() == dat2
		# check has exited, allow time for dbclient to exit
		time.sleep(0.1)
		assert r.poll() == 0