netdev - [PATCH net-next v3 1/4] selftests: drv-net: try to check if port is in use

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240626012456.2326192-2-kuba@kernel.org>
Date: Tue, 25 Jun 2024 18:24:53 -0700
From: Jakub Kicinski <kuba@...nel.org>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org,
	edumazet@...gle.com,
	pabeni@...hat.com,
	willemdebruijn.kernel@...il.com,
	ecree.xilinx@...il.com,
	dw@...idwei.uk,
	przemyslaw.kitszel@...el.com,
	michael.chan@...adcom.com,
	andrew.gospodarek@...adcom.com,
	leitao@...ian.org,
	petrm@...dia.com,
	Jakub Kicinski <kuba@...nel.org>
Subject: [PATCH net-next v3 1/4] selftests: drv-net: try to check if port is in use

We use random ports for communication. As Willem predicted
this leads to occasional failures. Try to check if port is
already in use by opening a socket and binding to that port.

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@...el.com>
Signed-off-by: Jakub Kicinski <kuba@...nel.org>
---
v3:
 - use errno.EADDRINUSE (Breno)
v2:
 - remove v4 check (Willem)
 - update comment (David, Przemek)
 - cap the iterations (Przemek)
---
 tools/testing/selftests/net/lib/py/utils.py | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/lib/py/utils.py b/tools/testing/selftests/net/lib/py/utils.py
index 0540ea24921d..dd9d2b9f2b20 100644
--- a/tools/testing/selftests/net/lib/py/utils.py
+++ b/tools/testing/selftests/net/lib/py/utils.py
@@ -1,8 +1,10 @@
 # SPDX-License-Identifier: GPL-2.0
 
+import errno
 import json as _json
 import random
 import re
+import socket
 import subprocess
 import time
 
@@ -79,9 +81,18 @@ import time
 
 def rand_port():
     """
-    Get unprivileged port, for now just random, one day we may decide to check if used.
+    Get a random unprivileged port, try to make sure it's not already used.
     """
-    return random.randint(10000, 65535)
+    for _ in range(1000):
+        port = random.randint(10000, 65535)
+        try:
+            with socket.socket(socket.AF_INET6, socket.SOCK_STREAM) as s:
+                s.bind(("", port))
+            return port
+        except OSError as e:
+            if e.errno != errno.EADDRINUSE:
+                raise
+    raise Exception("Can't find any free unprivileged port")
 
 
 def wait_port_listen(port, proto="tcp", ns=None, host=None, sleep=0.005, deadline=5):
-- 
2.45.2