test_sysctl: add generic script to expand on tests

This adds a generic script to let us more easily add more tests cases.
Since we really have only two types of tests cases just fold them into
the one file.  Each test unit is now identified into its separate
function:

    # ./sysctl.sh -l
  Test ID list:

  TEST_ID x NUM_TEST
  TEST_ID:   Test ID
  NUM_TESTS: Number of recommended times to run the test

  0001 x 1 - tests proc_dointvec_minmax()
  0002 x 1 - tests proc_dostring()

For now we start off with what we had before, and run only each test
once.  We can now watch a test case until it fails:

  ./sysctl.sh -w 0002

We can also run a test case x number of times, say we want to run a test
case 100 times:

  ./sysctl.sh -c 0001 100

To run a test case only once, for example:

  ./sysctl.sh -s 0002

The default settings are specified at the top of sysctl.sh.

Link: http://lkml.kernel.org/r/20170630224431.17374-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 494 insertions, 0 deletions

diff --git a/tools/testing/selftests/sysctl/sysctl.sh b/tools/testing/selftests/sysctl/sysctl.sh
new file mode 100644
index 000000000000..cbe1345d7c1d
--- /dev/null
+++ b/tools/testing/selftests/sysctl/sysctl.sh
@@ -0,0 +1,494 @@
+#!/bin/bash
+# Copyright (C) 2017 Luis R. Rodriguez <mcgrof@kernel.org>
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the Free
+# Software Foundation; either version 2 of the License, or at your option any
+# later version; or, when distributed separately from the Linux kernel or
+# when incorporated into other software packages, subject to the following
+# license:
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of copyleft-next (version 0.3.1 or later) as published
+# at http://copyleft-next.org/.
+
+# This performs a series tests against the proc sysctl interface.
+
+TEST_NAME="sysctl"
+TEST_DRIVER="test_${TEST_NAME}"
+TEST_DIR=$(dirname $0)
+TEST_FILE=$(mktemp)
+
+# This represents
+#
+# TEST_ID:TEST_COUNT:ENABLED
+#
+# TEST_ID: is the test id number
+# TEST_COUNT: number of times we should run the test
+# ENABLED: 1 if enabled, 0 otherwise
+#
+# Once these are enabled please leave them as-is. Write your own test,
+# we have tons of space.
+ALL_TESTS="0001:1:1"
+ALL_TESTS="$ALL_TESTS 0002:1:1"
+
+test_modprobe()
+{
+       if [ ! -d $DIR ]; then
+               echo "$0: $DIR not present" >&2
+               echo "You must have the following enabled in your kernel:" >&2
+               cat $TEST_DIR/config >&2
+               exit 1
+       fi
+}
+
+function allow_user_defaults()
+{
+	if [ -z $DIR ]; then
+		DIR="/sys/module/test_sysctl/"
+	fi
+	if [ -z $DEFAULT_NUM_TESTS ]; then
+		DEFAULT_NUM_TESTS=50
+	fi
+	if [ -z $SYSCTL ]; then
+		SYSCTL="/proc/sys/debug/test_sysctl"
+	fi
+	if [ -z $PROD_SYSCTL ]; then
+		PROD_SYSCTL="/proc/sys"
+	fi
+	if [ -z $WRITES_STRICT ]; then
+		WRITES_STRICT="${PROD_SYSCTL}/kernel/sysctl_writes_strict"
+	fi
+}
+
+function check_production_sysctl_writes_strict()
+{
+	echo -n "Checking production write strict setting ... "
+	if [ ! -e ${WRITES_STRICT} ]; then
+		echo "FAIL, but skip in case of old kernel" >&2
+	else
+		old_strict=$(cat ${WRITES_STRICT})
+		if [ "$old_strict" = "1" ]; then
+			echo "ok"
+		else
+			echo "FAIL, strict value is 0 but force to 1 to continue" >&2
+			echo "1" > ${WRITES_STRICT}
+		fi
+	fi
+}
+
+test_reqs()
+{
+	uid=$(id -u)
+	if [ $uid -ne 0 ]; then
+		echo $msg must be run as root >&2
+		exit 0
+	fi
+
+	if ! which perl 2> /dev/null > /dev/null; then
+		echo "$0: You need perl installed"
+		exit 1
+	fi
+}
+
+function load_req_mod()
+{
+	trap "test_modprobe" EXIT
+
+	if [ ! -d $DIR ]; then
+		modprobe $TEST_DRIVER
+		if [ $? -ne 0 ]; then
+			exit
+		fi
+	fi
+}
+
+set_orig()
+{
+	if [ ! -z $TARGET ]; then
+		echo "${ORIG}" > "${TARGET}"
+	fi
+}
+
+set_test()
+{
+	echo "${TEST_STR}" > "${TARGET}"
+}
+
+verify()
+{
+	local seen
+	seen=$(cat "$1")
+	if [ "${seen}" != "${TEST_STR}" ]; then
+		return 1
+	fi
+	return 0
+}
+
+test_rc()
+{
+	if [[ $rc != 0 ]]; then
+		echo "Failed test, return value: $rc" >&2
+		exit $rc
+	fi
+}
+
+test_finish()
+{
+	set_orig
+	rm -f "${TEST_FILE}"
+
+	if [ ! -z ${old_strict} ]; then
+		echo ${old_strict} > ${WRITES_STRICT}
+	fi
+	exit $rc
+}
+
+run_numerictests()
+{
+	echo "== Testing sysctl behavior against ${TARGET} =="
+
+	rc=0
+
+	echo -n "Writing test file ... "
+	echo "${TEST_STR}" > "${TEST_FILE}"
+	if ! verify "${TEST_FILE}"; then
+		echo "FAIL" >&2
+		exit 1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Checking sysctl is not set to test value ... "
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		exit 1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Writing sysctl from shell ... "
+	set_test
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		exit 1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Resetting sysctl to original value ... "
+	set_orig
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		exit 1
+	else
+		echo "ok"
+	fi
+
+	# Now that we've validated the sanity of "set_test" and "set_orig",
+	# we can use those functions to set starting states before running
+	# specific behavioral tests.
+
+	echo -n "Writing entire sysctl in single write ... "
+	set_orig
+	dd if="${TEST_FILE}" of="${TARGET}" bs=4096 2>/dev/null
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Writing middle of sysctl after synchronized seek ... "
+	set_test
+	dd if="${TEST_FILE}" of="${TARGET}" bs=1 seek=1 skip=1 2>/dev/null
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Writing beyond end of sysctl ... "
+	set_orig
+	dd if="${TEST_FILE}" of="${TARGET}" bs=20 seek=2 2>/dev/null
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Writing sysctl with multiple long writes ... "
+	set_orig
+	(perl -e 'print "A" x 50;'; echo "${TEST_STR}") | \
+		dd of="${TARGET}" bs=50 2>/dev/null
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	test_rc
+}
+
+run_stringtests()
+{
+	echo -n "Writing entire sysctl in short writes ... "
+	set_orig
+	dd if="${TEST_FILE}" of="${TARGET}" bs=1 2>/dev/null
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Writing middle of sysctl after unsynchronized seek ... "
+	set_test
+	dd if="${TEST_FILE}" of="${TARGET}" bs=1 seek=1 2>/dev/null
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Checking sysctl maxlen is at least $MAXLEN ... "
+	set_orig
+	perl -e 'print "A" x ('"${MAXLEN}"'-2), "B";' | \
+		dd of="${TARGET}" bs="${MAXLEN}" 2>/dev/null
+	if ! grep -q B "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Checking sysctl keeps original string on overflow append ... "
+	set_orig
+	perl -e 'print "A" x ('"${MAXLEN}"'-1), "B";' | \
+		dd of="${TARGET}" bs=$(( MAXLEN - 1 )) 2>/dev/null
+	if grep -q B "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Checking sysctl stays NULL terminated on write ... "
+	set_orig
+	perl -e 'print "A" x ('"${MAXLEN}"'-1), "B";' | \
+		dd of="${TARGET}" bs="${MAXLEN}" 2>/dev/null
+	if grep -q B "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Checking sysctl stays NULL terminated on overwrite ... "
+	set_orig
+	perl -e 'print "A" x ('"${MAXLEN}"'-1), "BB";' | \
+		dd of="${TARGET}" bs=$(( $MAXLEN + 1 )) 2>/dev/null
+	if grep -q B "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	test_rc
+}
+
+sysctl_test_0001()
+{
+	TARGET="${SYSCTL}/int_0001"
+	ORIG=$(cat "${TARGET}")
+	TEST_STR=$(( $ORIG + 1 ))
+
+	run_numerictests
+}
+
+sysctl_test_0002()
+{
+	TARGET="${SYSCTL}/string_0001"
+	ORIG=$(cat "${TARGET}")
+	TEST_STR="Testing sysctl"
+	# Only string sysctls support seeking/appending.
+	MAXLEN=65
+
+	run_numerictests
+	run_stringtests
+}
+
+list_tests()
+{
+	echo "Test ID list:"
+	echo
+	echo "TEST_ID x NUM_TEST"
+	echo "TEST_ID:   Test ID"
+	echo "NUM_TESTS: Number of recommended times to run the test"
+	echo
+	echo "0001 x $(get_test_count 0001) - tests proc_dointvec_minmax()"
+	echo "0002 x $(get_test_count 0002) - tests proc_dostring()"
+}
+
+test_reqs
+
+usage()
+{
+	NUM_TESTS=$(grep -o ' ' <<<"$ALL_TESTS" | grep -c .)
+	let NUM_TESTS=$NUM_TESTS+1
+	MAX_TEST=$(printf "%04d\n" $NUM_TESTS)
+	echo "Usage: $0 [ -t <4-number-digit> ] | [ -w <4-number-digit> ] |"
+	echo "		 [ -s <4-number-digit> ] | [ -c <4-number-digit> <test- count>"
+	echo "           [ all ] [ -h | --help ] [ -l ]"
+	echo ""
+	echo "Valid tests: 0001-$MAX_TEST"
+	echo ""
+	echo "    all     Runs all tests (default)"
+	echo "    -t      Run test ID the number amount of times is recommended"
+	echo "    -w      Watch test ID run until it runs into an error"
+	echo "    -c      Run test ID once"
+	echo "    -s      Run test ID x test-count number of times"
+	echo "    -l      List all test ID list"
+	echo " -h|--help  Help"
+	echo
+	echo "If an error every occurs execution will immediately terminate."
+	echo "If you are adding a new test try using -w <test-ID> first to"
+	echo "make sure the test passes a series of tests."
+	echo
+	echo Example uses:
+	echo
+	echo "$TEST_NAME.sh            -- executes all tests"
+	echo "$TEST_NAME.sh -t 0002    -- Executes test ID 0002 number of times is recomended"
+	echo "$TEST_NAME.sh -w 0002    -- Watch test ID 0002 run until an error occurs"
+	echo "$TEST_NAME.sh -s 0002    -- Run test ID 0002 once"
+	echo "$TEST_NAME.sh -c 0002 3  -- Run test ID 0002 three times"
+	echo
+	list_tests
+	exit 1
+}
+
+function test_num()
+{
+	re='^[0-9]+$'
+	if ! [[ $1 =~ $re ]]; then
+		usage
+	fi
+}
+
+function get_test_count()
+{
+	test_num $1
+	TEST_DATA=$(echo $ALL_TESTS | awk '{print $'$1'}')
+	LAST_TWO=${TEST_DATA#*:*}
+	echo ${LAST_TWO%:*}
+}
+
+function get_test_enabled()
+{
+	test_num $1
+	TEST_DATA=$(echo $ALL_TESTS | awk '{print $'$1'}')
+	echo ${TEST_DATA#*:*:}
+}
+
+function run_all_tests()
+{
+	for i in $ALL_TESTS ; do
+		TEST_ID=${i%:*:*}
+		ENABLED=$(get_test_enabled $TEST_ID)
+		TEST_COUNT=$(get_test_count $TEST_ID)
+		if [[ $ENABLED -eq "1" ]]; then
+			test_case $TEST_ID $TEST_COUNT
+		fi
+	done
+}
+
+function watch_log()
+{
+	if [ $# -ne 3 ]; then
+		clear
+	fi
+	date
+	echo "Running test: $2 - run #$1"
+}
+
+function watch_case()
+{
+	i=0
+	while [ 1 ]; do
+
+		if [ $# -eq 1 ]; then
+			test_num $1
+			watch_log $i ${TEST_NAME}_test_$1
+			${TEST_NAME}_test_$1
+		else
+			watch_log $i all
+			run_all_tests
+		fi
+		let i=$i+1
+	done
+}
+
+function test_case()
+{
+	NUM_TESTS=$DEFAULT_NUM_TESTS
+	if [ $# -eq 2 ]; then
+		NUM_TESTS=$2
+	fi
+
+	i=0
+	while [ $i -lt $NUM_TESTS ]; do
+		test_num $1
+		watch_log $i ${TEST_NAME}_test_$1 noclear
+		RUN_TEST=${TEST_NAME}_test_$1
+		$RUN_TEST
+		let i=$i+1
+	done
+}
+
+function parse_args()
+{
+	if [ $# -eq 0 ]; then
+		run_all_tests
+	else
+		if [[ "$1" = "all" ]]; then
+			run_all_tests
+		elif [[ "$1" = "-w" ]]; then
+			shift
+			watch_case $@
+		elif [[ "$1" = "-t" ]]; then
+			shift
+			test_num $1
+			test_case $1 $(get_test_count $1)
+		elif [[ "$1" = "-c" ]]; then
+			shift
+			test_num $1
+			test_num $2
+			test_case $1 $2
+		elif [[ "$1" = "-s" ]]; then
+			shift
+			test_case $1 1
+		elif [[ "$1" = "-l" ]]; then
+			list_tests
+		elif [[ "$1" = "-h" || "$1" = "--help" ]]; then
+			usage
+		else
+			usage
+		fi
+	fi
+}
+
+test_reqs
+allow_user_defaults
+check_production_sysctl_writes_strict
+load_req_mod
+
+trap "test_finish" EXIT
+
+parse_args $@
+
+exit 0