From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f44.google.com (mail-wm1-f44.google.com [209.85.128.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 258CC1DE2A0; Tue, 2 Sep 2025 15:03:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.44 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756825386; cv=none; b=ZHVt0xFGBEmaUBGiJ+8HKOlqj4KnuQlkHJchsYxWXxD5h3c3Wzbg0OFyjsMW8qjYN3J+jpW0xCBq1lvfooRsQxY6je9iLXAEQGmdfD70RsNZasKPPLcf1xkxxJBCRj0jJuourWRKYyf+qZBQU/G0eqHYJSD0WChkJth5YPeiPcA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756825386; c=relaxed/simple; bh=nCJi32g+2XrXf+4mA4uBGNHiEBbBcgVatkU/fgKodc4=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=u/XFwX+d69mrHYm5Bgsu6npTYvyhQwmg5g3ZRcC9sxOgKVtLHEwCXnMF5PBnLLP4us/ienyHvI2MKxKxuVxHUUGAoOo2NoBcJadtEpOI+238/zhEwCc0N9XnUSfStgbejNofD05w6BanAFf41WILETU60i9gx50EXibnRjQY92I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Q5t1J8OR; arc=none smtp.client-ip=209.85.128.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Q5t1J8OR" Received: by mail-wm1-f44.google.com with SMTP id 5b1f17b1804b1-45b79ec2fbeso37292825e9.3; Tue, 02 Sep 2025 08:03:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1756825383; x=1757430183; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=+q+6KxQjNGlpDK0FwgWdmK7uwlAylATpqLWZsT8oVn8=; b=Q5t1J8OR+52N94vE+ORBrOOkd5Tgurd+Cy6bHC7koEmNWwzvRE9fJK+LzWZz+hLIqU xgKjcc3mKdKvIkhibxs2e7Nyuhj/SA8ZEBERDSgz3K4A3DXRuXKNoJbjfp7uSl00aTnL Cp0oRBR2bG6Ru3uFVK5ZklQcVr+Lx6igAC++4TgZ1bp5AL9QNJtbwM2m0E3sORkbteVh s7sKfW5NRYVG2FpDUaep4DWnhMKvfWffcnzXmuFYPXTQYhKK6+hwJid/rJKsuPZTFWt/ 767Tb/yKaW+sJDAfdX0pNJTBWt/Rg7or5XJxecWu82xWB5TxaxIwZDFbYz+2+bKKLxER 8SCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756825383; x=1757430183; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=+q+6KxQjNGlpDK0FwgWdmK7uwlAylATpqLWZsT8oVn8=; b=d6z7bLrJZyQOQh+NiK8GaagyvgLPYqTtEESx/7YpdlFji/b0qjxqvs90YD8xrS0qKP c2UJJ3Bo8nm/xquEXAWCU3+iQUheYnz5v8pMqNdPhWBNIGs2OcTQSiZZEUPV2LsRHn88 1Vxwc6IK+RCSoMzvXGNzGykSu+20wmDtfY/PubkccgCDMVSwZv6NqMHflg4sfiEJmX8N naSDlx9OHivBMTZBsGJD+isGxzz4c8+vnVHOlcfBYhhOiNjRfSXmHSSMcV5+JKgm/eOa tyv7npvBlqik2H4qL0Ct1y+0QratRIUIA1G/GQT/1aWHKDadX04Cz1gJhkkiZLJcjcnp p4Zg== X-Forwarded-Encrypted: i=1; AJvYcCXGX4hPCI4E82m1LfUwNT1SysMUbuu6rGEv/sxWzHcx2BkG3j/fDL720FI51xQn5cvkg3VObHs=@vger.kernel.org X-Gm-Message-State: AOJu0Yzk7JEKOm3k+8ZKAe4SDSN1mdTg5I73xn+ZVAM4msxrCbuKQ8/h fSrAyWAJrvv68ri7eEcke8ZkZ7LPSbtjVj1ocwiH6wkWYUcPxo+JEMq9uQRR6/0b X-Gm-Gg: ASbGnctMvO3chagpj5DX1ZuVqsgiMT4rtls2Lj6CZtwKF4sop3BDl/0Nz02uh+IYlVI YHfFd+MIWTfs1xM/1PFnJzbb6NoBW2BIkPO3gGdmNEpll1tKA1C7EaohfY7eg0qPNHy0SyIZskw LY4YDaWjycS76I0yHuJe3RgstzRR99b+4wlX2vAhaxMoqIM/EogeiFYXd5LaXI7FZETBtSx5k+Q WG6X7Bpws2Je1udbKgmwnNMuUg/0qEMzhwYK3+zraRsPEf8q+bsEFxHffpIK76W+X9EYGnJq6CD ZtD0wPBtIv14xtCEvj8Zv4PYWa4d0k39kRAd0dRw/CU7DraRrcLhVCFoRJji36rfsdi0QAG9P3h a8l4o7sf+v2eOCFJzSf0LQPsPv3lo2XFvKOE= X-Google-Smtp-Source: AGHT+IG6qIR7Mz9ze8kV0dkEjDHFLIMXTiO/mwGxOMslVTSOdM/NzgwnMM7o6oftyrIuL4bODH6MyQ== X-Received: by 2002:a05:600c:46c6:b0:45b:84b1:b409 with SMTP id 5b1f17b1804b1-45b855ad0b0mr120431005e9.30.1756825382991; Tue, 02 Sep 2025 08:03:02 -0700 (PDT) Received: from oscar-xps.. ([79.127.164.81]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-45b7a938e75sm134978505e9.4.2025.09.02.08.02.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Sep 2025 08:03:02 -0700 (PDT) From: Oscar Maes To: netdev@vger.kernel.org, bacs@librecast.net, brett@librecast.net, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org Cc: davem@davemloft.net, dsahern@kernel.org, stable@vger.kernel.org, Oscar Maes Subject: [PATCH net v5] selftests: net: add test for destination in broadcast packets Date: Tue, 2 Sep 2025 17:02:40 +0200 Message-Id: <20250902150240.4272-1-oscmaes92@gmail.com> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add test to check the broadcast ethernet destination field is set correctly. This test sends a broadcast ping, captures it using tcpdump and ensures that all bits of the 6 octet ethernet destination address are correctly set by examining the output capture file. Co-developed-by: Brett A C Sheffield Signed-off-by: Brett A C Sheffield Signed-off-by: Oscar Maes --- v4 -> v5: - Fixed Signed-off-by chain v3 -> v4: - Added Brett as co-author - Wait for tcpdump to bind using slowwait Links: - Discussion: https://lore.kernel.org/netdev/20250822165231.4353-4-bacs@librecast.net/ - Previous version: https://lore.kernel.org/netdev/20250828114242.6433-1-oscmaes92@gmail.com/ Thanks to Brett Sheffield for co-developing this selftest! tools/testing/selftests/net/Makefile | 1 + .../selftests/net/broadcast_ether_dst.sh | 83 +++++++++++++++++++ 2 files changed, 84 insertions(+) create mode 100755 tools/testing/selftests/net/broadcast_ether_dst.sh diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index b31a71f2b372..56ad10ea6628 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -115,6 +115,7 @@ TEST_PROGS += skf_net_off.sh TEST_GEN_FILES += skf_net_off TEST_GEN_FILES += tfo TEST_PROGS += tfo_passive.sh +TEST_PROGS += broadcast_ether_dst.sh TEST_PROGS += broadcast_pmtu.sh TEST_PROGS += ipv6_force_forwarding.sh diff --git a/tools/testing/selftests/net/broadcast_ether_dst.sh b/tools/testing/selftests/net/broadcast_ether_dst.sh new file mode 100755 index 000000000000..334a7eca8a80 --- /dev/null +++ b/tools/testing/selftests/net/broadcast_ether_dst.sh @@ -0,0 +1,83 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Author: Brett A C Sheffield +# Author: Oscar Maes +# +# Ensure destination ethernet field is correctly set for +# broadcast packets + +source lib.sh + +CLIENT_IP4="192.168.0.1" +GW_IP4="192.168.0.2" + +setup() { + setup_ns CLIENT_NS SERVER_NS + + ip -net "${SERVER_NS}" link add link1 type veth \ + peer name link0 netns "${CLIENT_NS}" + + ip -net "${CLIENT_NS}" link set link0 up + ip -net "${CLIENT_NS}" addr add "${CLIENT_IP4}"/24 dev link0 + + ip -net "${SERVER_NS}" link set link1 up + + ip -net "${CLIENT_NS}" route add default via "${GW_IP4}" + ip netns exec "${CLIENT_NS}" arp -s "${GW_IP4}" 00:11:22:33:44:55 +} + +cleanup() { + rm -f "${CAPFILE}" "${OUTPUT}" + ip -net "${SERVER_NS}" link del link1 + cleanup_ns "${CLIENT_NS}" "${SERVER_NS}" +} + +test_broadcast_ether_dst() { + local rc=0 + CAPFILE=$(mktemp -u cap.XXXXXXXXXX) + OUTPUT=$(mktemp -u out.XXXXXXXXXX) + + echo "Testing ethernet broadcast destination" + + # start tcpdump listening for icmp + # tcpdump will exit after receiving a single packet + # timeout will kill tcpdump if it is still running after 2s + timeout 2s ip netns exec "${CLIENT_NS}" \ + tcpdump -i link0 -c 1 -w "${CAPFILE}" icmp &> "${OUTPUT}" & + pid=$! + slowwait 1 grep -qs "listening" "${OUTPUT}" + + # send broadcast ping + ip netns exec "${CLIENT_NS}" \ + ping -W0.01 -c1 -b 255.255.255.255 &> /dev/null + + # wait for tcpdump for exit after receiving packet + wait "${pid}" + + # compare ethernet destination field to ff:ff:ff:ff:ff:ff + ether_dst=$(tcpdump -r "${CAPFILE}" -tnne 2>/dev/null | \ + awk '{sub(/,/,"",$3); print $3}') + if [[ "${ether_dst}" == "ff:ff:ff:ff:ff:ff" ]]; then + echo "[ OK ]" + rc="${ksft_pass}" + else + echo "[FAIL] expected dst ether addr to be ff:ff:ff:ff:ff:ff," \ + "got ${ether_dst}" + rc="${ksft_fail}" + fi + + return "${rc}" +} + +if [ ! -x "$(command -v tcpdump)" ]; then + echo "SKIP: Could not run test without tcpdump tool" + exit "${ksft_skip}" +fi + +trap cleanup EXIT + +setup +test_broadcast_ether_dst + +exit $? -- 2.39.5