Commit 69d094ef authored by Breno Leitao's avatar Breno Leitao Committed by Jakub Kicinski
Browse files

selftests: net: add netconsole test for cmdline configuration 

Add a new selftest to verify netconsole module loading with command
line arguments. This test exercises the init_netconsole() path and
validates proper parsing of the netconsole= parameter format.

The test:
- Loads netconsole module with cmdline configuration instead of
  dynamic reconfiguration
- Validates message transmission through the configured target
- Adds helper functions for cmdline string generation and module
  validation

This complements existing netconsole selftests by covering the
module initialization code path that processes boot-time parameters.
This test is useful to test issues like the one described in [1].

Link: https://lore.kernel.org/netdev/Z36TlACdNMwFD7wv@dev-ushankar.dev.purestorage.com/

 [1]
Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250613-rework-v3-8-0752bf2e6912@debian.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent bed365ca

tools/testing/selftests/drivers/net/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ TEST_GEN_FILES := \ 
TEST_PROGS := \

	napi_id.py \

	netcons_basic.sh \

	netcons_cmdline.sh \

	netcons_fragmented_msg.sh \

	netcons_overflow.sh \

	netcons_sysdata.sh \

tools/testing/selftests/drivers/net/lib/sh/lib_netcons.sh

+33 −6
Original line number Diff line number Diff line
@@ -121,6 +121,17 @@ function create_dynamic_target() { 
	echo 1 > "${NETCONS_PATH}"/enabled

}



# Generate the command line argument for netconsole following:

#  netconsole=[+][src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr]

function create_cmdline_str() {

	DSTMAC=$(ip netns exec "${NAMESPACE}" \

		 ip link show "${DSTIF}" | awk '/ether/ {print $2}')

	SRCPORT="1514"

	TGTPORT="6666"



	echo "netconsole=\"+${SRCPORT}@${SRCIP}/${SRCIF},${TGTPORT}@${DSTIP}/${DSTMAC}\""

}



# Do not append the release to the header of the message

function disable_release_append() {

	echo 0 > "${NETCONS_PATH}"/enabled
@@ -173,13 +184,9 @@ function listen_port_and_save_to() { 
		socat UDP-LISTEN:"${PORT}",fork "${OUTPUT}"

}



function validate_result() {

# Only validate that the message arrived properly

function validate_msg() {

	local TMPFILENAME="$1"

	local FORMAT=${2:-"extended"}



	# TMPFILENAME will contain something like:

	# 6.11.1-0_fbk0_rc13_509_g30d75cea12f7,13,1822,115075213798,-;netconsole selftest: netcons_gtJHM

	#  key=value



	# Check if the file exists

	if [ ! -f "$TMPFILENAME" ]; then
@@ -192,6 +199,17 @@ function validate_result() { 
		cat "${TMPFILENAME}" >&2

		exit "${ksft_fail}"

	fi

}



# Validate the message and userdata

function validate_result() {

	local TMPFILENAME="$1"



	# TMPFILENAME will contain something like:

	# 6.11.1-0_fbk0_rc13_509_g30d75cea12f7,13,1822,115075213798,-;netconsole selftest: netcons_gtJHM

	#  key=value



	validate_msg "${TMPFILENAME}"



	# userdata is not supported on basic format target,

	# thus, do not validate it.
@@ -267,3 +285,12 @@ function pkill_socat() { 
	pkill -f "${PROCESS_NAME}"

	set -e

}



# Check if netconsole was compiled as a module, otherwise exit

function check_netconsole_module() {

	if modinfo netconsole | grep filename: | grep -q builtin

	then

		echo "SKIP: netconsole should be compiled as a module" >&2

		exit "${ksft_skip}"

	fi

}

tools/testing/selftests/drivers/net/netcons_cmdline.sh

0 → 100755
+52 −0
Original line number Diff line number Diff line 
#!/usr/bin/env bash

# SPDX-License-Identifier: GPL-2.0



# This is a selftest to test cmdline arguments on netconsole.

# It exercises loading of netconsole from cmdline instead of the dynamic

# reconfiguration. This includes parsing the long netconsole= line and all the

# flow through init_netconsole().

#

# Author: Breno Leitao <leitao@debian.org>



set -euo pipefail



SCRIPTDIR=$(dirname "$(readlink -e "${BASH_SOURCE[0]}")")



source "${SCRIPTDIR}"/lib/sh/lib_netcons.sh



check_netconsole_module



modprobe netdevsim 2> /dev/null || true

rmmod netconsole 2> /dev/null || true



# The content of kmsg will be save to the following file

OUTPUT_FILE="/tmp/${TARGET}"



# Check for basic system dependency and exit if not found

# check_for_dependencies

# Set current loglevel to KERN_INFO(6), and default to KERN_NOTICE(5)

echo "6 5" > /proc/sys/kernel/printk

# Remove the namespace and network interfaces

trap do_cleanup EXIT

# Create one namespace and two interfaces

set_network

# Create the command line for netconsole, with the configuration from the

# function above

CMDLINE="$(create_cmdline_str)"



# Load the module, with the cmdline set

modprobe netconsole "${CMDLINE}"



# Listed for netconsole port inside the namespace and destination interface

listen_port_and_save_to "${OUTPUT_FILE}" &

# Wait for socat to start and listen to the port.

wait_local_port_listen "${NAMESPACE}" "${PORT}" udp

# Send the message

echo "${MSG}: ${TARGET}" > /dev/kmsg

# Wait until socat saves the file to disk

busywait "${BUSYWAIT_TIMEOUT}" test -s "${OUTPUT_FILE}"

# Make sure the message was received in the dst part

# and exit

validate_msg "${OUTPUT_FILE}"



exit "${ksft_pass}"