selftests: ncdevmem: add tx test with multiple IOVs

Use prime 3 for length to make offset slowly drift away.

Signed-off-by: Stanislav Fomichev <[email protected]>
Acked-by: Mina Almasry <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Stanislav Fomichev

tools/testing/selftests/drivers/net/hw/devmem.py

@@ -49,12 +49,27 @@ def check_tx(cfg) -> None:
     ksft_eq(socat.stdout.strip(), "hello\nworld")
 
 
+@ksft_disruptive
+def check_tx_chunks(cfg) -> None:
+    cfg.require_ipver("6")
+    require_devmem(cfg)
+
+    port = rand_port()
+    listen_cmd = f"socat -U - TCP6-LISTEN:{port}"
+
+    with bkg(listen_cmd, exit_wait=True) as socat:
+        wait_port_listen(port)
+        cmd(f"echo -e \"hello\\nworld\"| {cfg.bin_remote} -f {cfg.ifname} -s {cfg.addr_v['6']} -p {port} -z 3", host=cfg.remote, shell=True)
+
+    ksft_eq(socat.stdout.strip(), "hello\nworld")
+
+
 def main() -> None:
     with NetDrvEpEnv(__file__) as cfg:
         cfg.bin_local = path.abspath(path.dirname(__file__) + "/ncdevmem")
         cfg.bin_remote = cfg.remote.deploy(cfg.bin_local)
 
-        ksft_run([check_rx, check_tx],
+        ksft_run([check_rx, check_tx, check_tx_chunks],
                  args=(cfg, ))
     ksft_exit()