[PATCH net-next v2] selftests: netconsole: Validate interface selection by MAC address

[Andre Carvalho <asantostc@gmail.com>]

Extend the existing netconsole cmdline selftest to also validate that
interface selection can be performed via MAC address.

The test now validates that netconsole works with both interface name
and MAC address, improving test coverage.

Suggested-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Andre Carvalho <asantostc@gmail.com>
---
Changes in v2:
- Redirect log line to stderr
- Do not ignore error unloading the module between test cases
- Remove nested quotes when building cmdline for module
- Format comments to avoid exceeding 80 columns
- Link to v1: https://lore.kernel.org/r/20250811-netcons-cmdline-selftest-v1-1-1f725ab020fa@gmail.com
---
 .../selftests/drivers/net/lib/sh/lib_netcons.sh    | 10 +++-
 .../selftests/drivers/net/netcons_cmdline.sh       | 55 +++++++++++++---------
 2 files changed, 43 insertions(+), 22 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/lib/sh/lib_netcons.sh b/tools/testing/selftests/drivers/net/lib/sh/lib_netcons.sh
index b6071e80ebbb6a33283ab6cd6bcb7b925aefdb43..8e1085e896472d5c87ec8b236240878a5b2d00d2 100644
--- a/tools/testing/selftests/drivers/net/lib/sh/lib_netcons.sh
+++ b/tools/testing/selftests/drivers/net/lib/sh/lib_netcons.sh
@@ -148,12 +148,20 @@ function create_dynamic_target() {
 # Generate the command line argument for netconsole following:
 #  netconsole=[+][src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr]
 function create_cmdline_str() {
+	local BINDMODE=${1:-"ifname"}
+	if [ "${BINDMODE}" == "ifname" ]
+	then
+		SRCDEV=${SRCIF}
+	else
+		SRCDEV=$(mac_get "${SRCIF}")
+	fi
+
 	DSTMAC=$(ip netns exec "${NAMESPACE}" \
 		 ip link show "${DSTIF}" | awk '/ether/ {print $2}')
 	SRCPORT="1514"
 	TGTPORT="6666"
 
-	echo "netconsole=\"+${SRCPORT}@${SRCIP}/${SRCIF},${TGTPORT}@${DSTIP}/${DSTMAC}\""
+	echo "netconsole=\"+${SRCPORT}@${SRCIP}/${SRCDEV},${TGTPORT}@${DSTIP}/${DSTMAC}\""
 }
 
 # Do not append the release to the header of the message
diff --git a/tools/testing/selftests/drivers/net/netcons_cmdline.sh b/tools/testing/selftests/drivers/net/netcons_cmdline.sh
index ad2fb8b1c46326c69af20f2c9d68e80fa8eb894f..d1d23dc67f99aa357041b71718550ed94292e57a 100755
--- a/tools/testing/selftests/drivers/net/netcons_cmdline.sh
+++ b/tools/testing/selftests/drivers/net/netcons_cmdline.sh
@@ -19,9 +19,6 @@ 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/${TARGET}"
-
 # Check for basic system dependency and exit if not found
 # check_for_dependencies
 # Set current loglevel to KERN_INFO(6), and default to KERN_NOTICE(5)
@@ -30,23 +27,39 @@ echo "6 5" > /proc/sys/kernel/printk
 trap do_cleanup EXIT
 # Create one namespace and two interfaces
 set_network
-# Create the command line for netconsole, with the configuration from the
-# function above
-CMDLINE="$(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}"
+
+# Run the test twice, with different cmdline parameters
+for BINDMODE in "ifname" "mac"
+do
+	echo "Running with bind mode: ${BINDMODE}" >&2
+	# Create the command line for netconsole, with the configuration from
+	# the function above
+	CMDLINE=$(create_cmdline_str "${BINDMODE}")
+
+	# The content of kmsg will be save to the following file
+	OUTPUT_FILE="/tmp/${TARGET}-${BINDMODE}"
+
+	# Load the module, with the cmdline set
+	modprobe netconsole "${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}"
+
+	# kill socat in case it is still running
+	pkill_socat
+	# Unload the module
+	rmmod netconsole
+	echo "${BINDMODE} : Test passed" >&2
+done
 
 exit "${ksft_pass}"

---
base-commit: 37816488247ddddbc3de113c78c83572274b1e2e
change-id: 20250807-netcons-cmdline-selftest-b32e27a4bd16

Best regards,
-- 
Andre Carvalho <asantostc@gmail.com>