[PATCH net-next v5] net: netconsole: selftests: Create a new netconsole selftest

Breno Leitao
2024-08-19T09:04:25Z

Adds a selftest that creates two virtual interfaces, assigns one to a
new namespace, and assigns IP addresses to both.

It listens on the destination interface using socat and configures a
dynamic target on netconsole, pointing to the destination IP address.

The test then checks if the message was received properly on the
destination interface.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Changelog:

v5:
* Replace check_file_size() by "test -s" (Matthieu)

v4:
* Avoid sleeping in waiting for sockets and files (Matthieu Baerts)
* Some other improvements (Matthieu Baerts)
* Add configfs as a dependency (Jakub)
* https://lore.kernel.org/all/20240816132450.346744-1-leitao@debian.org/

v3:
* Defined CONFIGs in config file (Jakub)
* Identention fixes (Petr Machata)
* Use setup_ns in a better way (Matthieu Baerts)
* Add dependencies in TEST_INCLUDES (Hangbin Liu)
* https://lore.kernel.org/all/20240815095157.3064722-1-leitao@debian.org/

v2:
* Change the location of the path (Jakub)
* Move from veth to netdevsim
* Other small changes in dependency checks and cleanup
* https://lore.kernel.org/all/20240813183825.837091-1-leitao@debian.org/

v1:
* https://lore.kernel.org/all/ZqyUHN770pjSofTC@gmail.com/

MAINTAINERS | 1 +
tools/testing/selftests/drivers/net/Makefile | 5 +-
tools/testing/selftests/drivers/net/config | 4 +
.../selftests/drivers/net/netcons_basic.sh | 225 ++++++++++++++++++
4 files changed, 234 insertions(+), 1 deletion(-)
create mode 100755 tools/testing/selftests/drivers/net/netcons_basic.sh

diff --git a/MAINTAINERS b/MAINTAINERS
index 5dbf23cf11c8..9a371ddd8719 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15772,6 +15772,7 @@ M: Breno Leitao <leitao@debian.org>
S: Maintained
F: Documentation/networking/netconsole.rst
F: drivers/net/netconsole.c
+F: tools/testing/selftests/drivers/net/netcons_basic.sh

NETDEVSIM
M: Jakub Kicinski <kuba@kernel.org>
diff --git a/tools/testing/selftests/drivers/net/Makefile b/tools/testing/selftests/drivers/net/Makefile
index e54f382bcb02..39fb97a8c1df 100644
--- a/tools/testing/selftests/drivers/net/Makefile
+++ b/tools/testing/selftests/drivers/net/Makefile
@@ -1,8 +1,11 @@
# SPDX-License-Identifier: GPL-2.0

-TEST_INCLUDES := $(wildcard lib/py/*.py)
+TEST_INCLUDES := $(wildcard lib/py/*.py) \
+ ../../net/net_helper.sh \
+ ../../net/lib.sh \

TEST_PROGS := \
+ netcons_basic.sh \
ping.py \
queues.py \
stats.py \
diff --git a/tools/testing/selftests/drivers/net/config b/tools/testing/selftests/drivers/net/config
index f6a58ce8a230..a2d8af60876d 100644
--- a/tools/testing/selftests/drivers/net/config
+++ b/tools/testing/selftests/drivers/net/config
@@ -1,2 +1,6 @@
CONFIG_IPV6=y
CONFIG_NETDEVSIM=m
+CONFIG_CONFIGFS_FS=y
+CONFIG_NETCONSOLE=m
+CONFIG_NETCONSOLE_DYNAMIC=y
+CONFIG_NETCONSOLE_EXTENDED_LOG=y
diff --git a/tools/testing/selftests/drivers/net/netcons_basic.sh b/tools/testing/selftests/drivers/net/netcons_basic.sh
new file mode 100755
index 000000000000..137875505663
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/netcons_basic.sh
@@ -0,0 +1,225 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This test creates two netdevsim virtual interfaces, assigns one of them (the
+# "destination interface") to a new namespace, and assigns IP addresses to both
+# interfaces.
+#
+# It listens on the destination interface using socat and configures a dynamic
+# target on netconsole, pointing to the destination IP address.
+#
+# Finally, it checks whether the message was received properly on the
+# destination interface. Note that this test may pollute the kernel log buffer
+# (dmesg) and relies on dynamic configuration and namespaces being configured.
+#
+# Author: Breno Leitao <leitao@debian.org>
+
+set -euo pipefail
+
+SCRIPTDIR=$(dirname "$(readlink -e "${BASH_SOURCE[0]}")")
+
+# Simple script to test dynamic targets in netconsole
+SRCIF="" # to be populated later
+SRCIP=192.168.1.1
+DSTIF="" # to be populated later
+DSTIP=192.168.1.2
+
+PORT="6666"
+MSG="netconsole selftest"
+TARGET=$(mktemp -u netcons_XXXXX)
+NETCONS_CONFIGFS="/sys/kernel/config/netconsole"
+NETCONS_PATH="${NETCONS_CONFIGFS}"/"${TARGET}"
+# NAMESPACE will be populated by setup_ns with a random value
+NAMESPACE=""
+
+# IDs for netdevsim
+NSIM_DEV_1_ID=$((256 + RANDOM % 256))
+NSIM_DEV_2_ID=$((512 + RANDOM % 256))
+
+# Used to create and delete namespaces
+source "${SCRIPTDIR}"/../../net/lib.sh
+source "${SCRIPTDIR}"/../../net/net_helper.sh
+
+# Create netdevsim interfaces
+create_ifaces() {
+ local NSIM_DEV_SYS_NEW=/sys/bus/netdevsim/new_device
+
+ echo "$NSIM_DEV_2_ID" > "$NSIM_DEV_SYS_NEW"
+ echo "$NSIM_DEV_1_ID" > "$NSIM_DEV_SYS_NEW"
+ udevadm settle 2> /dev/null || true
+
+ local NSIM1=/sys/bus/netdevsim/devices/netdevsim"$NSIM_DEV_1_ID"
+ local NSIM2=/sys/bus/netdevsim/devices/netdevsim"$NSIM_DEV_2_ID"
+
+ # These are global variables
+ SRCIF=$(find "$NSIM1"/net -maxdepth 1 -type d ! \
+ -path "$NSIM1"/net -exec basename {} \;)
+ DSTIF=$(find "$NSIM2"/net -maxdepth 1 -type d ! \
+ -path "$NSIM2"/net -exec basename {} \;)
+}
+
+link_ifaces() {
+ local NSIM_DEV_SYS_LINK="/sys/bus/netdevsim/link_device"
+ local SRCIF_IFIDX=$(cat /sys/class/net/"$SRCIF"/ifindex)
+ local DSTIF_IFIDX=$(cat /sys/class/net/"$DSTIF"/ifindex)
+
+ exec {NAMESPACE_FD}</var/run/netns/"${NAMESPACE}"
+ exec {INITNS_FD}</proc/self/ns/net
+
+ # Bind the dst interface to namespace
+ ip link set "${DSTIF}" netns "${NAMESPACE}"
+
+ # Linking one device to the other one (on the other namespace}
+ if ! echo "${INITNS_FD}:$SRCIF_IFIDX $NAMESPACE_FD:$DSTIF_IFIDX" > $NSIM_DEV_SYS_LINK
+ then
+ echo "linking netdevsim1 with netdevsim2 should succeed"
+ cleanup
+ exit "${ksft_skip}"
+ fi
+}
+
+function configure_ip() {
+ # Configure the IPs for both interfaces
+ ip netns exec "${NAMESPACE}" ip addr add "${DSTIP}"/24 dev "${DSTIF}"
+ ip netns exec "${NAMESPACE}" ip link set "${DSTIF}" up
+
+ ip addr add "${SRCIP}"/24 dev "${SRCIF}"
+ ip link set "${SRCIF}" up
+}
+
+function set_network() {
+ # setup_ns function is coming from lib.sh
+ setup_ns NAMESPACE
+
+ # Create both interfaces, and assign the destination to a different
+ # namespace
+ create_ifaces
+
+ # Link both interfaces back to back
+ link_ifaces
+
+ configure_ip
+}
+
+function create_dynamic_target() {
+ DSTMAC=$(ip netns exec "${NAMESPACE}" \
+ ip link show "${DSTIF}" | awk '/ether/ {print $2}')
+
+ # Create a dynamic target
+ mkdir "${NETCONS_PATH}"
+
+ echo "${DSTIP}" > "${NETCONS_PATH}"/remote_ip
+ echo "${SRCIP}" > "${NETCONS_PATH}"/local_ip
+ echo "${DSTMAC}" > "${NETCONS_PATH}"/remote_mac
+ echo "${SRCIF}" > "${NETCONS_PATH}"/dev_name
+
+ echo 1 > "${NETCONS_PATH}"/enabled
+}
+
+function cleanup() {
+ local NSIM_DEV_SYS_DEL="/sys/bus/netdevsim/del_device"
+
+ # delete netconsole dynamic reconfiguration
+ echo 0 > "${NETCONS_PATH}"/enabled
+ # Remove the configfs entry
+ rmdir "${NETCONS_PATH}"
+
+ # Delete netdevsim devices
+ echo "$NSIM_DEV_2_ID" > "$NSIM_DEV_SYS_DEL"
+ echo "$NSIM_DEV_1_ID" > "$NSIM_DEV_SYS_DEL"
+
+ # this is coming from lib.sh
+ cleanup_all_ns
+}
+
+function listen_port_and_save_to() {
+ local OUTPUT=${1}
+ # Just wait for 2 seconds
+ timeout 2 ip netns exec "${NAMESPACE}" \
+ socat UDP-LISTEN:"${PORT}",fork "${OUTPUT}"
+}
+
+function validate_result() {
+ local TMPFILENAME="$1"
+
+ # Check if the file exists
+ if [ ! -f "$TMPFILENAME" ]; then
+ echo "FAIL: File was not generated." >&2
+ exit "${ksft_fail}"
+ fi
+
+ if ! grep -q "${MSG}" "${TMPFILENAME}"; then
+ echo "FAIL: ${MSG} not found in ${TMPFILENAME}" >&2
+ cat "${TMPFILENAME}" >&2
+ exit "${ksft_fail}"
+ fi
+
+ # Delete the file once it is validated, otherwise keep it
+ # for debugging purposes
+ rm "${TMPFILENAME}"
+ exit "${ksft_pass}"
+}
+
+function check_for_dependencies() {
+ if [ "$(id -u)" -ne 0 ]; then
+ echo "This test must be run as root" >&2
+ exit "${ksft_skip}"
+ fi
+
+ if ! which socat > /dev/null ; then
+ echo "SKIP: socat(1) is not available" >&2
+ exit "${ksft_skip}"
+ fi
+
+ if ! which ip > /dev/null ; then
+ echo "SKIP: ip(1) is not available" >&2
+ exit "${ksft_skip}"
+ fi
+
+ if ! which udevadm > /dev/null ; then
+ echo "SKIP: udevadm(1) is not available" >&2
+ exit "${ksft_skip}"
+ fi
+
+ if [ ! -d "${NETCONS_CONFIGFS}" ]; then
+ echo "SKIP: directory ${NETCONS_CONFIGFS} does not exist. Check if NETCONSOLE_DYNAMIC is enabled" >&2
+ exit "${ksft_skip}"
+ fi
+
+ if ip link show "${DSTIF}" 2> /dev/null; then
+ echo "SKIP: interface ${DSTIF} exists in the system. Not overwriting it." >&2
+ exit "${ksft_skip}"
+ fi
+}
+
+# ========== #
+# Start here #
+# ========== #
+modprobe netdevsim 2> /dev/null || true
+modprobe netconsole 2 > /dev/null || true
+
+# The content of kmsg will be save to the following file
+OUTPUT_FILE="/tmp/${TARGET}"
+
+# Check for basic system dependency and exit if not found
+check_for_dependencies
+# Set current loglevel to KERN_INFO(6), and default to KERN_NOTICE(5)
+echo "6 5" > /proc/sys/kernel/printk
+# Remove the namespace, interfaces and netconsole target on exit
+trap cleanup EXIT
+# Create one namespace and two interfaces
+set_network
+# Create a dynamic target for netconsole
+create_dynamic_target
+# Listed for netconsole port inside the namespace and destination interface
+listen_port_and_save_to "${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 "${OUTPUT_FILE}"
+
+# Make sure the message was received in the dst part
+# and exit
+validate_result "${OUTPUT_FILE}"
--
2.43.5