Jakub Kicinski wrote: > More complex tests often have to spawn a background process, > like a server which will respond to requests or tcpdump. > > Add support for creating such processes using the with keyword: > > with bkg("my-daemon", ..): > # my-daemon is alive in this block > > My initial thought was to add this support to cmd() directly > but it runs the command in the constructor, so by the time > we __enter__ it's too late to make sure we used "background=True". > > Second useful helper transplanted from net_helper.sh is > wait_port_listen(). > > Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> > --- > tools/testing/selftests/drivers/net/ping.py | 24 +++++++++++++-- > tools/testing/selftests/net/lib/py/utils.py | 33 +++++++++++++++++++++ > 2 files changed, 55 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/drivers/net/ping.py b/tools/testing/selftests/drivers/net/ping.py > index 58aefd3e740f..8532e3be72ba 100755 > --- a/tools/testing/selftests/drivers/net/ping.py > +++ b/tools/testing/selftests/drivers/net/ping.py > @@ -1,9 +1,12 @@ > #!/usr/bin/env python3 > # SPDX-License-Identifier: GPL-2.0 > > -from lib.py import ksft_run, ksft_exit, KsftXfailEx > +import random > + > +from lib.py import ksft_run, ksft_exit > +from lib.py import ksft_eq, KsftXfailEx > from lib.py import NetDrvEpEnv > -from lib.py import cmd > +from lib.py import bkg, cmd, wait_port_listen > > > def test_v4(cfg) -> None: > @@ -22,6 +25,23 @@ from lib.py import cmd > cmd(f"ping -c 1 -W0.5 {cfg.v6}", host=cfg.remote) > > > +def test_tcp(cfg) -> None: > + port = random.randrange(1024 + (1 << 15)) > + with bkg(f"nc -l {cfg.addr} {port}") as nc: > + wait_port_listen(port) > + > + cmd(f"echo ping | nc {cfg.addr} {port}", > + shell=True, host=cfg.remote) > + ksft_eq(nc.stdout.strip(), "ping") > + > + port = random.randrange(1024 + (1 << 15)) > + with bkg(f"nc -l {cfg.remote_addr} {port}", host=cfg.remote) as nc: > + wait_port_listen(port, host=cfg.remote) > + > + cmd(f"echo ping | nc {cfg.remote_addr} {port}", shell=True) > + ksft_eq(nc.stdout.strip(), "ping") > + There are different netcat implementations floating around. I notice that I have to pass -N on the client to terminate the connection after EOF. Else both peers keep the connection open, waiting for input. And explicitly pass -6 if passing an IPv6 address. I think this is the one that ships with Debian..