selftests: rds: add testing infrastructure

This adds some basic self-testing infrastructure for RDS-TCP.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/dev-tools/gcov.rst

@@ -75,6 +75,17 @@ Only files which are linked to the main kernel image or are compiled as
 kernel modules are supported by this mechanism.
 
 
+Module specific configs
+-----------------------
+
+Gcov kernel configs for specific modules are described below:
+
+CONFIG_GCOV_PROFILE_RDS:
+        Enables GCOV profiling on RDS for checking which functions or
+        lines are executed. This config is used by the rds selftest to
+        generate coverage reports. If left unset the report is omitted.
+
+
 Files
 -----
 

MAINTAINERS

@@ -19197,6 +19197,7 @@ S:	Supported
 W:	https://oss.oracle.com/projects/rds/
 F:	Documentation/networking/rds.rst
 F:	net/rds/
+F:	tools/testing/selftests/net/rds/
 
 RDT - RESOURCE ALLOCATION
 M:	Fenghua Yu <fenghua.yu@intel.com>

tools/testing/selftests/Makefile

@@ -68,6 +68,7 @@ TARGETS += net/mptcp
 TARGETS += net/openvswitch
 TARGETS += net/tcp_ao
 TARGETS += net/netfilter
+TARGETS += net/rds
 TARGETS += nsfs
 TARGETS += perf_events
 TARGETS += pidfd

tools/testing/selftests/net/rds/Makefile

@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+
+all:
+	@echo mk_build_dir="$(shell pwd)" > include.sh
+
+TEST_PROGS := run.sh \
+	include.sh \
+	test.py
+
+EXTRA_CLEAN := /tmp/rds_logs
+
+include ../../lib.mk

tools/testing/selftests/net/rds/README.txt

@@ -0,0 +1,41 @@
+RDS self-tests
+==============
+
+These scripts provide a coverage test for RDS-TCP by creating two
+network namespaces and running rds packets between them. A loopback
+network is provisioned with optional probability of packet loss or
+corruption. A workload of 50000 hashes, each 64 characters in size,
+are passed over an RDS socket on this test network. A passing test means
+the RDS-TCP stack was able to recover properly.  The provided config.sh
+can be used to compile the kernel with the necessary gcov options.  The
+kernel may optionally be configured to omit the coverage report as well.
+
+USAGE:
+	run.sh [-d logdir] [-l packet_loss] [-c packet_corruption]
+	       [-u packet_duplcate]
+
+OPTIONS:
+	-d	Log directory.  Defaults to tools/testing/selftests/net/rds/rds_logs
+
+	-l	Simulates a percentage of packet loss
+
+	-c	Simulates a percentage of packet corruption
+
+	-u	Simulates a percentage of packet duplication.
+
+EXAMPLE:
+
+    # Create a suitable gcov enabled .config
+    tools/testing/selftests/net/rds/config.sh -g
+
+    # Alternatly create a gcov disabled .config
+    tools/testing/selftests/net/rds/config.sh
+
+    # build the kernel
+    vng --build  --config tools/testing/selftests/net/config
+
+    # launch the tests in a VM
+    vng -v --rwdir ./ --run . --user root --cpus 4 -- \
+        "export PYTHONPATH=tools/testing/selftests/net/; tools/testing/selftests/net/rds/run.sh"
+
+An HTML coverage report will be output in tools/testing/selftests/net/rds/rds_logs/coverage/.

tools/testing/selftests/net/rds/config.sh

@@ -0,0 +1,53 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+set -u
+set -x
+
+unset KBUILD_OUTPUT
+
+GENERATE_GCOV_REPORT=0
+while getopts "g" opt; do
+  case ${opt} in
+    g)
+      GENERATE_GCOV_REPORT=1
+      ;;
+    :)
+      echo "USAGE: config.sh [-g]"
+      exit 1
+      ;;
+    ?)
+      echo "Invalid option: -${OPTARG}."
+      exit 1
+      ;;
+  esac
+done
+
+CONF_FILE="tools/testing/selftests/net/config"
+
+# no modules
+scripts/config --file "$CONF_FILE" --disable CONFIG_MODULES
+
+# enable RDS
+scripts/config --file "$CONF_FILE" --enable CONFIG_RDS
+scripts/config --file "$CONF_FILE" --enable CONFIG_RDS_TCP
+
+if [ "$GENERATE_GCOV_REPORT" -eq 1 ]; then
+	# instrument RDS and only RDS
+	scripts/config --file "$CONF_FILE" --enable CONFIG_GCOV_KERNEL
+	scripts/config --file "$CONF_FILE" --disable GCOV_PROFILE_ALL
+	scripts/config --file "$CONF_FILE" --enable GCOV_PROFILE_RDS
+else
+	scripts/config --file "$CONF_FILE" --disable CONFIG_GCOV_KERNEL
+	scripts/config --file "$CONF_FILE" --disable GCOV_PROFILE_ALL
+	scripts/config --file "$CONF_FILE" --disable GCOV_PROFILE_RDS
+fi
+
+# need network namespaces to run tests with veth network interfaces
+scripts/config --file "$CONF_FILE" --enable CONFIG_NET_NS
+scripts/config --file "$CONF_FILE" --enable CONFIG_VETH
+
+# simulate packet loss
+scripts/config --file "$CONF_FILE" --enable CONFIG_NET_SCH_NETEM
+

tools/testing/selftests/net/rds/run.sh

@@ -0,0 +1,224 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+set -u
+
+unset KBUILD_OUTPUT
+
+current_dir="$(realpath "$(dirname "$0")")"
+build_dir="$current_dir"
+
+build_include="$current_dir/include.sh"
+if test -f "$build_include"; then
+	# this include will define "$mk_build_dir" as the location the test was
+	# built.  We will need this if the tests are installed in a location
+	# other than the kernel source
+
+	source "$build_include"
+	build_dir="$mk_build_dir"
+fi
+
+# This test requires kernel source and the *.gcda data therein
+# Locate the top level of the kernel source, and the net/rds
+# subfolder with the appropriate *.gcno object files
+ksrc_dir="$(realpath "$build_dir"/../../../../../)"
+kconfig="$ksrc_dir/.config"
+obj_dir="$ksrc_dir/net/rds"
+
+GCOV_CMD=gcov
+
+#check to see if the host has the required packages to generate a gcov report
+check_gcov_env()
+{
+	if ! which "$GCOV_CMD" > /dev/null 2>&1; then
+		echo "Warning: Could not find gcov. "
+		GENERATE_GCOV_REPORT=0
+		return
+	fi
+
+	# the gcov version must match the gcc version
+	GCC_VER=$(gcc -dumpfullversion)
+	GCOV_VER=$($GCOV_CMD -v | grep gcov | awk '{print $3}'| awk 'BEGIN {FS="-"}{print $1}')
+	if [ "$GCOV_VER" != "$GCC_VER" ]; then
+		#attempt to find a matching gcov version
+		GCOV_CMD=gcov-$(gcc -dumpversion)
+
+		if ! which "$GCOV_CMD" > /dev/null 2>&1; then
+			echo "Warning: Could not find an appropriate gcov installation. \
+				gcov version must match gcc version"
+			GENERATE_GCOV_REPORT=0
+			return
+		fi
+
+		#recheck version number of found gcov executable
+		GCOV_VER=$($GCOV_CMD -v | grep gcov | awk '{print $3}'| \
+			awk 'BEGIN {FS="-"}{print $1}')
+		if [ "$GCOV_VER" != "$GCC_VER" ]; then
+			echo "Warning: Could not find an appropriate gcov installation. \
+				gcov version must match gcc version"
+			GENERATE_GCOV_REPORT=0
+		else
+			echo "Warning: Mismatched gcc and gcov detected.  Using $GCOV_CMD"
+		fi
+	fi
+}
+
+# Check to see if the kconfig has the required configs to generate a coverage report
+check_gcov_conf()
+{
+	if ! grep -x "CONFIG_GCOV_PROFILE_RDS=y" "$kconfig" > /dev/null 2>&1; then
+		echo "INFO: CONFIG_GCOV_PROFILE_RDS should be enabled for coverage reports"
+		GENERATE_GCOV_REPORT=0
+	fi
+	if ! grep -x "CONFIG_GCOV_KERNEL=y" "$kconfig" > /dev/null 2>&1; then
+		echo "INFO: CONFIG_GCOV_KERNEL should be enabled for coverage reports"
+		GENERATE_GCOV_REPORT=0
+	fi
+	if grep -x "CONFIG_GCOV_PROFILE_ALL=y" "$kconfig" > /dev/null 2>&1; then
+		echo "INFO: CONFIG_GCOV_PROFILE_ALL should be disabled for coverage reports"
+		GENERATE_GCOV_REPORT=0
+	fi
+
+	if [ "$GENERATE_GCOV_REPORT" -eq 0 ]; then
+		echo "To enable gcov reports, please run "\
+			"\"tools/testing/selftests/net/rds/config.sh -g\" and rebuild the kernel"
+	else
+		# if we have the required kernel configs, proceed to check the environment to
+		# ensure we have the required gcov packages
+		check_gcov_env
+	fi
+}
+
+# Kselftest framework requirement - SKIP code is 4.
+check_conf_enabled() {
+	if ! grep -x "$1=y" "$kconfig" > /dev/null 2>&1; then
+		echo "selftests: [SKIP] This test requires $1 enabled"
+		echo "Please run tools/testing/selftests/net/rds/config.sh and rebuild the kernel"
+		exit 4
+	fi
+}
+check_conf_disabled() {
+	if grep -x "$1=y" "$kconfig" > /dev/null 2>&1; then
+		echo "selftests: [SKIP] This test requires $1 disabled"
+		echo "Please run tools/testing/selftests/net/rds/config.sh and rebuild the kernel"
+		exit 4
+	fi
+}
+check_conf() {
+	check_conf_enabled CONFIG_NET_SCH_NETEM
+	check_conf_enabled CONFIG_VETH
+	check_conf_enabled CONFIG_NET_NS
+	check_conf_enabled CONFIG_RDS_TCP
+	check_conf_enabled CONFIG_RDS
+	check_conf_disabled CONFIG_MODULES
+}
+
+check_env()
+{
+	if ! test -d "$obj_dir"; then
+		echo "selftests: [SKIP] This test requires a kernel source tree"
+		exit 4
+	fi
+	if ! test -e "$kconfig"; then
+		echo "selftests: [SKIP] This test requires a configured kernel source tree"
+		exit 4
+	fi
+	if ! which strace > /dev/null 2>&1; then
+		echo "selftests: [SKIP] Could not run test without strace"
+		exit 4
+	fi
+	if ! which tcpdump > /dev/null 2>&1; then
+		echo "selftests: [SKIP] Could not run test without tcpdump"
+		exit 4
+	fi
+
+	if ! which python3 > /dev/null 2>&1; then
+		echo "selftests: [SKIP] Could not run test without python3"
+		exit 4
+	fi
+
+	python_major=$(python3 -c "import sys; print(sys.version_info[0])")
+	python_minor=$(python3 -c "import sys; print(sys.version_info[1])")
+	if [[ python_major -lt 3 || ( python_major -eq 3 && python_minor -lt 9 ) ]] ; then
+		echo "selftests: [SKIP] Could not run test without at least python3.9"
+		python3 -V
+		exit 4
+	fi
+}
+
+LOG_DIR="$current_dir"/rds_logs
+PLOSS=0
+PCORRUPT=0
+PDUP=0
+GENERATE_GCOV_REPORT=1
+while getopts "d:l:c:u:" opt; do
+  case ${opt} in
+    d)
+      LOG_DIR=${OPTARG}
+      ;;
+    l)
+      PLOSS=${OPTARG}
+      ;;
+    c)
+      PCORRUPT=${OPTARG}
+      ;;
+    u)
+      PDUP=${OPTARG}
+      ;;
+    :)
+      echo "USAGE: run.sh [-d logdir] [-l packet_loss] [-c packet_corruption]" \
+           "[-u packet_duplcate] [-g]"
+      exit 1
+      ;;
+    ?)
+      echo "Invalid option: -${OPTARG}."
+      exit 1
+      ;;
+  esac
+done
+
+
+check_env
+check_conf
+check_gcov_conf
+
+
+rm -fr "$LOG_DIR"
+TRACE_FILE="${LOG_DIR}/rds-strace.txt"
+COVR_DIR="${LOG_DIR}/coverage/"
+mkdir -p  "$LOG_DIR"
+mkdir -p "$COVR_DIR"
+
+set +e
+echo running RDS tests...
+echo Traces will be logged to "$TRACE_FILE"
+rm -f "$TRACE_FILE"
+strace -T -tt -o "$TRACE_FILE" python3 "$(dirname "$0")/test.py" --timeout 400 -d "$LOG_DIR" \
+       -l "$PLOSS" -c "$PCORRUPT" -u "$PDUP"
+
+test_rc=$?
+dmesg > "${LOG_DIR}/dmesg.out"
+
+if [ "$GENERATE_GCOV_REPORT" -eq 1 ]; then
+       echo saving coverage data...
+       (set +x; cd /sys/kernel/debug/gcov; find ./* -name '*.gcda' | \
+       while read -r f
+       do
+               cat < "/sys/kernel/debug/gcov/$f" > "/$f"
+       done)
+
+       echo running gcovr...
+       gcovr -s --html-details --gcov-executable "$GCOV_CMD" --gcov-ignore-parse-errors \
+             -o "${COVR_DIR}/gcovr" "${ksrc_dir}/net/rds/"
+else
+       echo "Coverage report will be skipped"
+fi
+
+if [ "$test_rc" -eq 0 ]; then
+	echo "PASS: Test completed successfully"
+else
+	echo "FAIL: Test failed"
+fi
+
+exit "$test_rc"