sendpfast is stopped improperly

[badcodebuilder]

Brief description

Sub process of tcpreplay invoked by sendpfast cannot be stopped when pressing Ctrl+C

More detailed, cmd created in sendrecv.py is not terminated manually

scapy/scapy/sendrecv.py

Lines 584 to 600 in 20a3468

	with ContextManagerSubprocess(conf.prog.tcpreplay):
	try:
	cmd = subprocess.Popen(argv, stdout=subprocess.PIPE,
	stderr=subprocess.PIPE)
	except KeyboardInterrupt:
	log_interactive.info("Interrupted by user")
	except Exception:
	os.unlink(f)
	raise
	else:
	stdout, stderr = cmd.communicate()
	if stderr:
	log_runtime.warning(stderr.decode())
	if parse_results:
	results = _parse_tcpreplay_result(stdout, stderr, argv)
	elif conf.verb > 2:
	log_runtime.info(stdout.decode())

Scapy version

2.6.1

Python version

3.13

Operating system

Linux 6.13.6-arch1-1

Additional environment information

tcpreplay: 4.5.1-1

How to reproduce

In interactive environment

>>> def pkt_gen(dst_ip: str, dport: int):
...:    while True:
...:        yield Ether()/IP(dst=dst_ip)/UDP(dport=dport)/"Hello, world"

>>> gen = pkt_gen("192.168.56.1", 10000)
>>> pkts = PacketList([next(gen) for _ in range(0x400)])
>>> sendpfast(pkts, loop=0, iface="enp0s8")

wait for a few seconds and press Ctrl+C

Actual result

^CERROR: tcpreplay: execution failed (type)
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/scapy/sendrecv.py", line 559, in sendpfast
    stdout, stderr = cmd.communicate()
                     ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/subprocess.py", line 1207, in communicate
    stdout, stderr = self._communicate(input, endtime, timeout)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/subprocess.py", line 2059, in _communicate
    ready = selector.select(timeout)
            ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/selectors.py", line 415, in select
    fd_event_list = self._selector.poll(timeout)
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
KeyboardInterrupt
<ipython-input-5-c6c71ec35432>:1: ResourceWarning: unclosed file <_io.BufferedReader name=12>
  sendpfast(pkts, loop=0, iface="enp0s8")
ResourceWarning: Enable tracemalloc to get the object allocation traceback
<ipython-input-5-c6c71ec35432>:1: ResourceWarning: unclosed file <_io.BufferedReader name=14>
  sendpfast(pkts, loop=0, iface="enp0s8")
ResourceWarning: Enable tracemalloc to get the object allocation traceback

Here are explanations of the two bugs above (before explaining, I will pin relative codes here):

scapy/scapy/sendrecv.py

Lines 584 to 600 in 20a3468

	with ContextManagerSubprocess(conf.prog.tcpreplay):
	try:
	cmd = subprocess.Popen(argv, stdout=subprocess.PIPE,
	stderr=subprocess.PIPE)
	except KeyboardInterrupt:
	log_interactive.info("Interrupted by user")
	except Exception:
	os.unlink(f)
	raise
	else:
	stdout, stderr = cmd.communicate()
	if stderr:
	log_runtime.warning(stderr.decode())
	if parse_results:
	results = _parse_tcpreplay_result(stdout, stderr, argv)
	elif conf.verb > 2:
	log_runtime.info(stdout.decode())

1. ERROR: tcpreplay ...: after waiting for a few seconds, cmd has been created correctly without any exception, it is waiting for stdout and stderr at line 594. Then the Ctrl+C is pressed, and KeyboardInterrupt happens, caught by ContextManagerSubprocess at line 584, it raises the exceptions
2. ResourceWarning ...: the pipelines of stdout and stderr are not read and closed, because the exception is raised when communicating, then codes after line 594 will not be executed

Expected result

^CINFO: Interrupted by user
WARNING:  User interrupt...

Related resources

No response