selftests: add test-cases for MPTCP MP_JOIN

Use the pm netlink to configure the creation of several
subflows, and verify that via MIB counters.

Update the mptcp_connect program to allow reliable MP_JOIN
handshake even on small data file
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/mptcp/Makefile

@@ -5,7 +5,7 @@ KSFT_KHDR_INSTALL := 1
 
 CFLAGS =  -Wall -Wl,--no-as-needed -O2 -g  -I$(top_srcdir)/usr/include
 
-TEST_PROGS := mptcp_connect.sh pm_netlink.sh
+TEST_PROGS := mptcp_connect.sh pm_netlink.sh mptcp_join.sh
 
 TEST_GEN_FILES = mptcp_connect pm_nl_ctl
 

tools/testing/selftests/net/mptcp/mptcp_connect.c

@@ -51,6 +51,7 @@ static bool tcpulp_audit;
 static int pf = AF_INET;
 static int cfg_sndbuf;
 static int cfg_rcvbuf;
+static bool cfg_join;
 
 static void die_usage(void)
 {
@@ -250,6 +251,7 @@ static int sock_connect_mptcp(const char * const remoteaddr,
 
 static size_t do_rnd_write(const int fd, char *buf, const size_t len)
 {
+	static bool first = true;
 	unsigned int do_w;
 	ssize_t bw;
 
@@ -257,10 +259,19 @@ static size_t do_rnd_write(const int fd, char *buf, const size_t len)
 	if (do_w == 0 || do_w > len)
 		do_w = len;
 
+	if (cfg_join && first && do_w > 100)
+		do_w = 100;
+
 	bw = write(fd, buf, do_w);
 	if (bw < 0)
 		perror("write");
 
+	/* let the join handshake complete, before going on */
+	if (cfg_join && first) {
+		usleep(200000);
+		first = false;
+	}
+
 	return bw;
 }
 
@@ -385,8 +396,11 @@ static int copyfd_io_poll(int infd, int peerfd, int outfd)
 					break;
 
 				/* ... but we still receive.
-				 * Close our write side.
+				 * Close our write side, ev. give some time
+				 * for address notification
 				 */
+				if (cfg_join)
+					usleep(400000);
 				shutdown(peerfd, SHUT_WR);
 			} else {
 				if (errno == EINTR)
@@ -403,6 +417,10 @@ static int copyfd_io_poll(int infd, int peerfd, int outfd)
 		}
 	}
 
+	/* leave some time for late join/announce */
+	if (cfg_join)
+		usleep(400000);
+
 	close(peerfd);
 	return 0;
 }
@@ -658,7 +676,7 @@ static void maybe_close(int fd)
 {
 	unsigned int r = rand();
 
-	if (r & 1)
+	if (!cfg_join && (r & 1))
 		close(fd);
 }
 
@@ -794,8 +812,12 @@ static void parse_opts(int argc, char **argv)
 {
 	int c;
 
-	while ((c = getopt(argc, argv, "6lp:s:hut:m:S:R:")) != -1) {
+	while ((c = getopt(argc, argv, "6jlp:s:hut:m:S:R:")) != -1) {
 		switch (c) {
+		case 'j':
+			cfg_join = true;
+			cfg_mode = CFG_MODE_POLL;
+			break;
 		case 'l':
 			listen_mode = true;
 			break;

tools/testing/selftests/net/mptcp/mptcp_join.sh

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+ret=0
+sin=""
+sout=""
+cin=""
+cout=""
+ksft_skip=4
+timeout=30
+capture=0
+
+TEST_COUNT=0
+
+init()
+{
+	capout=$(mktemp)
+
+	rndh=$(printf %x $sec)-$(mktemp -u XXXXXX)
+
+	ns1="ns1-$rndh"
+	ns2="ns2-$rndh"
+
+	for netns in "$ns1" "$ns2";do
+		ip netns add $netns || exit $ksft_skip
+		ip -net $netns link set lo up
+		ip netns exec $netns sysctl -q net.mptcp.enabled=1
+		ip netns exec $netns sysctl -q net.ipv4.conf.all.rp_filter=0
+		ip netns exec $netns sysctl -q net.ipv4.conf.default.rp_filter=0
+	done
+
+	#  ns1              ns2
+	# ns1eth1    ns2eth1
+	# ns1eth2    ns2eth2
+	# ns1eth3    ns2eth3
+	# ns1eth4    ns2eth4
+
+	for i in `seq 1 4`; do
+		ip link add ns1eth$i netns "$ns1" type veth peer name ns2eth$i netns "$ns2"
+		ip -net "$ns1" addr add 10.0.$i.1/24 dev ns1eth$i
+		ip -net "$ns1" addr add dead:beef:$i::1/64 dev ns1eth$i nodad
+		ip -net "$ns1" link set ns1eth$i up
+
+		ip -net "$ns2" addr add 10.0.$i.2/24 dev ns2eth$i
+		ip -net "$ns2" addr add dead:beef:$i::2/64 dev ns2eth$i nodad
+		ip -net "$ns2" link set ns2eth$i up
+
+		# let $ns2 reach any $ns1 address from any interface
+		ip -net "$ns2" route add default via 10.0.$i.1 dev ns2eth$i metric 10$i
+	done
+}
+
+cleanup_partial()
+{
+	rm -f "$capout"
+
+	for netns in "$ns1" "$ns2"; do
+		ip netns del $netns
+	done
+}
+
+cleanup()
+{
+	rm -f "$cin" "$cout"
+	rm -f "$sin" "$sout"
+	cleanup_partial
+}
+
+reset()
+{
+	cleanup_partial
+	init
+}
+
+for arg in "$@"; do
+	if [ "$arg" = "-c" ]; then
+		capture=1
+	fi
+done
+
+ip -Version > /dev/null 2>&1
+if [ $? -ne 0 ];then
+	echo "SKIP: Could not run test without ip tool"
+	exit $ksft_skip
+fi
+
+
+check_transfer()
+{
+	in=$1
+	out=$2
+	what=$3
+
+	cmp "$in" "$out" > /dev/null 2>&1
+	if [ $? -ne 0 ] ;then
+		echo "[ FAIL ] $what does not match (in, out):"
+		print_file_err "$in"
+		print_file_err "$out"
+
+		return 1
+	fi
+
+	return 0
+}
+
+do_ping()
+{
+	listener_ns="$1"
+	connector_ns="$2"
+	connect_addr="$3"
+
+	ip netns exec ${connector_ns} ping -q -c 1 $connect_addr >/dev/null
+	if [ $? -ne 0 ] ; then
+		echo "$listener_ns -> $connect_addr connectivity [ FAIL ]" 1>&2
+		ret=1
+	fi
+}
+
+do_transfer()
+{
+	listener_ns="$1"
+	connector_ns="$2"
+	cl_proto="$3"
+	srv_proto="$4"
+	connect_addr="$5"
+
+	port=$((10000+$TEST_COUNT))
+	TEST_COUNT=$((TEST_COUNT+1))
+
+	:> "$cout"
+	:> "$sout"
+	:> "$capout"
+
+	if [ $capture -eq 1 ]; then
+		if [ -z $SUDO_USER ] ; then
+			capuser=""
+		else
+			capuser="-Z $SUDO_USER"
+		fi
+
+		capfile="mp_join-${listener_ns}.pcap"
+
+		echo "Capturing traffic for test $TEST_COUNT into $capfile"
+		ip netns exec ${listener_ns} tcpdump -i any -s 65535 -B 32768 $capuser -w $capfile > "$capout" 2>&1 &
+		cappid=$!
+
+		sleep 1
+	fi
+
+	ip netns exec ${listener_ns} ./mptcp_connect -j -t $timeout -l -p $port -s ${srv_proto} 0.0.0.0 < "$sin" > "$sout" &
+	spid=$!
+
+	sleep 1
+
+	ip netns exec ${connector_ns} ./mptcp_connect -j -t $timeout -p $port -s ${cl_proto} $connect_addr < "$cin" > "$cout" &
+	cpid=$!
+
+	wait $cpid
+	retc=$?
+	wait $spid
+	rets=$?
+
+	if [ $capture -eq 1 ]; then
+	    sleep 1
+	    kill $cappid
+	fi
+
+	if [ ${rets} -ne 0 ] || [ ${retc} -ne 0 ]; then
+		echo " client exit code $retc, server $rets" 1>&2
+		echo "\nnetns ${listener_ns} socket stat for $port:" 1>&2
+		ip netns exec ${listener_ns} ss -nita 1>&2 -o "sport = :$port"
+		echo "\nnetns ${connector_ns} socket stat for $port:" 1>&2
+		ip netns exec ${connector_ns} ss -nita 1>&2 -o "dport = :$port"
+
+		cat "$capout"
+		return 1
+	fi
+
+	check_transfer $sin $cout "file received by client"
+	retc=$?
+	check_transfer $cin $sout "file received by server"
+	rets=$?
+
+	if [ $retc -eq 0 ] && [ $rets -eq 0 ];then
+		cat "$capout"
+		return 0
+	fi
+
+	cat "$capout"
+	return 1
+}
+
+make_file()
+{
+	name=$1
+	who=$2
+
+	SIZE=1
+
+	dd if=/dev/urandom of="$name" bs=1024 count=$SIZE 2> /dev/null
+	echo -e "\nMPTCP_TEST_FILE_END_MARKER" >> "$name"
+
+	echo "Created $name (size $SIZE KB) containing data sent by $who"
+}
+
+run_tests()
+{
+	listener_ns="$1"
+	connector_ns="$2"
+	connect_addr="$3"
+	lret=0
+
+	do_transfer ${listener_ns} ${connector_ns} MPTCP MPTCP ${connect_addr}
+	lret=$?
+	if [ $lret -ne 0 ]; then
+		ret=$lret
+		return
+	fi
+}
+
+chk_join_nr()
+{
+	local msg="$1"
+	local syn_nr=$2
+	local syn_ack_nr=$3
+	local ack_nr=$4
+	local count
+	local dump_stats
+
+	printf "%-36s %s" "$msg" "syn"
+	count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinSynRx | awk '{print $2}'`
+	[ -z "$count" ] && count=0
+	if [ "$count" != "$syn_nr" ]; then
+		echo "[fail] got $count JOIN[s] syn expected $syn_nr"
+		ret=1
+		dump_stats=1
+	else
+		echo -n "[ ok ]"
+	fi
+
+	echo -n " - synack"
+	count=`ip netns exec $ns2 nstat -as | grep MPTcpExtMPJoinSynAckRx | awk '{print $2}'`
+	[ -z "$count" ] && count=0
+	if [ "$count" != "$syn_ack_nr" ]; then
+		echo "[fail] got $count JOIN[s] synack expected $syn_ack_nr"
+		ret=1
+		dump_stats=1
+	else
+		echo -n "[ ok ]"
+	fi
+
+	echo -n " - ack"
+	count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinAckRx | awk '{print $2}'`
+	[ -z "$count" ] && count=0
+	if [ "$count" != "$ack_nr" ]; then
+		echo "[fail] got $count JOIN[s] ack expected $ack_nr"
+		ret=1
+		dump_stats=1
+	else
+		echo "[ ok ]"
+	fi
+	if [ "${dump_stats}" = 1 ]; then
+		echo Server ns stats
+		ip netns exec $ns1 nstat -as | grep MPTcp
+		echo Client ns stats
+		ip netns exec $ns2 nstat -as | grep MPTcp
+	fi
+}
+
+sin=$(mktemp)
+sout=$(mktemp)
+cin=$(mktemp)
+cout=$(mktemp)
+init
+make_file "$cin" "client"
+make_file "$sin" "server"
+trap cleanup EXIT
+
+run_tests $ns1 $ns2 10.0.1.1
+chk_join_nr "no JOIN" "0" "0" "0"
+
+# subflow limted by client
+reset
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+run_tests $ns1 $ns2 10.0.1.1
+chk_join_nr "single subflow, limited by client" 0 0 0
+
+# subflow limted by server
+reset
+ip netns exec $ns2 ./pm_nl_ctl limits 0 1
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+run_tests $ns1 $ns2 10.0.1.1
+chk_join_nr "single subflow, limited by server" 1 1 0
+
+# subflow
+reset
+ip netns exec $ns1 ./pm_nl_ctl limits 0 1
+ip netns exec $ns2 ./pm_nl_ctl limits 0 1
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+run_tests $ns1 $ns2 10.0.1.1
+chk_join_nr "single subflow" 1 1 1
+
+# multiple subflows
+reset
+ip netns exec $ns1 ./pm_nl_ctl limits 0 2
+ip netns exec $ns2 ./pm_nl_ctl limits 0 2
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.2.2 flags subflow
+run_tests $ns1 $ns2 10.0.1.1
+chk_join_nr "multiple subflows" 2 2 2
+
+# multiple subflows limited by serverf
+reset
+ip netns exec $ns1 ./pm_nl_ctl limits 0 1
+ip netns exec $ns2 ./pm_nl_ctl limits 0 2
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.2.2 flags subflow
+run_tests $ns1 $ns2 10.0.1.1
+chk_join_nr "multiple subflows, limited by server" 2 2 1
+
+# add_address, unused
+reset
+ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
+run_tests $ns1 $ns2 10.0.1.1
+chk_join_nr "unused signal address" 0 0 0
+
+# accept and use add_addr
+reset
+ip netns exec $ns1 ./pm_nl_ctl limits 0 1
+ip netns exec $ns2 ./pm_nl_ctl limits 1 1
+ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
+run_tests $ns1 $ns2 10.0.1.1
+chk_join_nr "signal address" 1 1 1
+
+# accept and use add_addr with an additional subflow
+# note: signal address in server ns and local addresses in client ns must
+# belong to different subnets or one of the listed local address could be
+# used for 'add_addr' subflow
+reset
+ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
+ip netns exec $ns1 ./pm_nl_ctl limits 0 2
+ip netns exec $ns2 ./pm_nl_ctl limits 1 2
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+run_tests $ns1 $ns2 10.0.1.1
+chk_join_nr "subflow and signal" 2 2 2
+
+# accept and use add_addr with additional subflows
+reset
+ip netns exec $ns1 ./pm_nl_ctl limits 0 3
+ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
+ip netns exec $ns2 ./pm_nl_ctl limits 1 3
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.4.2 flags subflow
+run_tests $ns1 $ns2 10.0.1.1
+chk_join_nr "multiple subflows and signal" 3 3 3
+
+exit $ret