selftests: mptcp: add tproxy test case

No hard dependencies here, just skip if test environ lacks
nft binary or the needed kernel config options.

The test case spawns listener in ns2 but ns1 will connect
to the ip address of ns4.

policy routing + tproxy rule will redirect packets to ns2 instead
of forward.

v3: - update mptcp/config (Mat Martineau)
    - more verbose SKIP messages in mptcp_connect.sh

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 80 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.sh b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
index 559173a8e387..a4226b608c68 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
@@ -671,6 +671,82 @@ run_tests()
 	run_tests_lo $1 $2 $3 0
 }
 
+run_test_transparent()
+{
+	local connect_addr="$1"
+	local msg="$2"
+
+	local connector_ns="$ns1"
+	local listener_ns="$ns2"
+	local lret=0
+	local r6flag=""
+
+	# skip if we don't want v6
+	if ! $ipv6 && is_v6 "${connect_addr}"; then
+		return 0
+	fi
+
+ip netns exec "$listener_ns" nft -f /dev/stdin <<"EOF"
+flush ruleset
+table inet mangle {
+	chain divert {
+		type filter hook prerouting priority -150;
+
+		meta l4proto tcp socket transparent 1 meta mark set 1 accept
+		tcp dport 20000 tproxy to :20000 meta mark set 1 accept
+	}
+}
+EOF
+	if [ $? -ne 0 ]; then
+		echo "SKIP: $msg, could not load nft ruleset"
+		return
+	fi
+
+	local local_addr
+	if is_v6 "${connect_addr}"; then
+		local_addr="::"
+		r6flag="-6"
+	else
+		local_addr="0.0.0.0"
+	fi
+
+	ip -net "$listener_ns" $r6flag rule add fwmark 1 lookup 100
+	if [ $? -ne 0 ]; then
+		ip netns exec "$listener_ns" nft flush ruleset
+		echo "SKIP: $msg, ip $r6flag rule failed"
+		return
+	fi
+
+	ip -net "$listener_ns" route add local $local_addr/0 dev lo table 100
+	if [ $? -ne 0 ]; then
+		ip netns exec "$listener_ns" nft flush ruleset
+		ip -net "$listener_ns" $r6flag rule del fwmark 1 lookup 100
+		echo "SKIP: $msg, ip route add local $local_addr failed"
+		return
+	fi
+
+	echo "INFO: test $msg"
+
+	TEST_COUNT=10000
+	local extra_args="-o TRANSPARENT"
+	do_transfer ${listener_ns} ${connector_ns} MPTCP MPTCP \
+		    ${connect_addr} ${local_addr} "${extra_args}"
+	lret=$?
+
+	ip netns exec "$listener_ns" nft flush ruleset
+	ip -net "$listener_ns" $r6flag rule del fwmark 1 lookup 100
+	ip -net "$listener_ns" route del local $local_addr/0 dev lo table 100
+
+	if [ $lret -ne 0 ]; then
+		echo "FAIL: $msg, mptcp connection error" 1>&2
+		ret=$lret
+		return 1
+	fi
+
+	echo "PASS: $msg"
+	return 0
+}
+
 run_tests_peekmode()
 {
 	local peekmode="$1"
@@ -794,5 +870,9 @@ run_tests_peekmode "saveWithPeek"
 run_tests_peekmode "saveAfterPeek"
 stop_if_error "Tests with peek mode have failed"
 
+# connect to ns4 ip address, ns2 should intercept/proxy
+run_test_transparent 10.0.3.1 "tproxy ipv4"
+run_test_transparent dead:beef:3::1 "tproxy ipv6"
+
 display_time
 exit $ret