selftests: fib_rule_tests: Test UDP and TCP connections with DSCP rules.

Add the fib_rule6_send and fib_rule4_send tests to verify that DSCP
values are properly taken into account when UDP or TCP sockets try to
connect().

Tests are done with nettest, which needs a new option to specify
the DS Field value of the socket being tested. This new option is
named '-Q', in reference to the similar option used by ping.

Signed-off-by: Guillaume Nault <[e-mail]>
Reviewed-by: David Ahern <[e-mail]>
Signed-off-by: Jakub Kicinski <[e-mail]>

tools/testing/selftests/net/fib_rule_tests.sh

···
 
 PAUSE_ON_FAIL=${PAUSE_ON_FAIL:=no}
 IP="ip -netns testns"
+IP_PEER="ip -netns peerns"
 
 RTABLE=100
+RTABLE_PEER=101
 GW_IP4=192.51.100.2
 SRC_IP=192.51.100.3
 GW_IP6=2001:db8:1::2
···
 DEV_ADDR=192.51.100.1
 DEV_ADDR6=2001:db8:1::1
 DEV=dummy0
-TESTS="fib_rule6 fib_rule4"
+TESTS="fib_rule6 fib_rule4 fib_rule6_connect fib_rule4_connect"
+
+SELFTEST_PATH=""
 
 log_test()
 {
···
 	echo "######################################################################"
 }
 
+check_nettest()
+{
+	if which nettest > /dev/null 2>&1; then
+		return 0
+	fi
+
+	# Add the selftest directory to PATH if not already done
+	if [ "${SELFTEST_PATH}" = "" ]; then
+		SELFTEST_PATH="$(dirname $0)"
+		PATH="${PATH}:${SELFTEST_PATH}"
+
+		# Now retry with the new path
+		if which nettest > /dev/null 2>&1; then
+			return 0
+		fi
+
+		if [ "${ret}" -eq 0 ]; then
+			ret="${ksft_skip}"
+		fi
+		echo "nettest not found (try 'make -C ${SELFTEST_PATH} nettest')"
+	fi
+
+	return 1
+}
+
 setup()
 {
 	set -e
···
 {
 	$IP link del dev dummy0 &> /dev/null
 	ip netns del testns
+}
+
+setup_peer()
+{
+	set -e
+
+	ip netns add peerns
+	$IP_PEER link set dev lo up
+
+	ip link add name veth0 netns testns type veth \
+		peer name veth1 netns peerns
+	$IP link set dev veth0 up
+	$IP_PEER link set dev veth1 up
+
+	$IP address add 192.0.2.10 peer 192.0.2.11/32 dev veth0
+	$IP_PEER address add 192.0.2.11 peer 192.0.2.10/32 dev veth1
+
+	$IP address add 2001:db8::10 peer 2001:db8::11/128 dev veth0 nodad
+	$IP_PEER address add 2001:db8::11 peer 2001:db8::10/128 dev veth1 nodad
+
+	$IP_PEER address add 198.51.100.11/32 dev lo
+	$IP route add table $RTABLE_PEER 198.51.100.11/32 via 192.0.2.11
+
+	$IP_PEER address add 2001:db8::1:11/128 dev lo
+	$IP route add table $RTABLE_PEER 2001:db8::1:11/128 via 2001:db8::11
+
+	set +e
+}
+
+cleanup_peer()
+{
+	$IP link del dev veth0
+	ip netns del peerns
 }
 
 fib_check_iproute_support()
···
 	fi
 }
 
+# Verify that the IPV6_TCLASS option of UDPv6 and TCPv6 sockets is properly
+# taken into account when connecting the socket and when sending packets.
+fib_rule6_connect_test()
+{
+	local dsfield
+
+	if ! check_nettest; then
+		echo "SKIP: Could not run test without nettest tool"
+		return
+	fi
+
+	setup_peer
+	$IP -6 rule add dsfield 0x04 table $RTABLE_PEER
+
+	# Combine the base DS Field value (0x04) with all possible ECN values
+	# (Not-ECT: 0, ECT(1): 1, ECT(0): 2, CE: 3).
+	# The ECN bits shouldn't influence the result of the test.
+	for dsfield in 0x04 0x05 0x06 0x07; do
+		nettest -q -6 -B -t 5 -N testns -O peerns -U -D \
+			-Q "${dsfield}" -l 2001:db8::1:11 -r 2001:db8::1:11
+		log_test $? 0 "rule6 dsfield udp connect (dsfield ${dsfield})"
+
+		nettest -q -6 -B -t 5 -N testns -O peerns -Q "${dsfield}" \
+			-l 2001:db8::1:11 -r 2001:db8::1:11
+		log_test $? 0 "rule6 dsfield tcp connect (dsfield ${dsfield})"
+	done
+
+	$IP -6 rule del dsfield 0x04 table $RTABLE_PEER
+	cleanup_peer
+}
+
 fib_rule4_del()
 {
 	$IP rule del $1
···
 	fi
 }
 
+# Verify that the IP_TOS option of UDPv4 and TCPv4 sockets is properly taken
+# into account when connecting the socket and when sending packets.
+fib_rule4_connect_test()
+{
+	local dsfield
+
+	if ! check_nettest; then
+		echo "SKIP: Could not run test without nettest tool"
+		return
+	fi
+
+	setup_peer
+	$IP -4 rule add dsfield 0x04 table $RTABLE_PEER
+
+	# Combine the base DS Field value (0x04) with all possible ECN values
+	# (Not-ECT: 0, ECT(1): 1, ECT(0): 2, CE: 3).
+	# The ECN bits shouldn't influence the result of the test.
+	for dsfield in 0x04 0x05 0x06 0x07; do
+		nettest -q -B -t 5 -N testns -O peerns -D -U -Q "${dsfield}" \
+			-l 198.51.100.11 -r 198.51.100.11
+		log_test $? 0 "rule4 dsfield udp connect (dsfield ${dsfield})"
+
+		nettest -q -B -t 5 -N testns -O peerns -Q "${dsfield}" \
+			-l 198.51.100.11 -r 198.51.100.11
+		log_test $? 0 "rule4 dsfield tcp connect (dsfield ${dsfield})"
+	done
+
+	$IP -4 rule del dsfield 0x04 table $RTABLE_PEER
+	cleanup_peer
+}
+
 run_fibrule_tests()
 {
 	log_section "IPv4 fib rule"
···
 	case $t in
 	fib_rule6_test|fib_rule6)		fib_rule6_test;;
 	fib_rule4_test|fib_rule4)		fib_rule4_test;;
+	fib_rule6_connect_test|fib_rule6_connect)	fib_rule6_connect_test;;
+	fib_rule4_connect_test|fib_rule4_connect)	fib_rule4_connect_test;;
 
 	help) echo "Test names: $TESTS"; exit 0;;
 

tools/testing/selftests/net/nettest.c

···
 	int use_setsockopt;
 	int use_freebind;
 	int use_cmsg;
+	uint8_t dsfield;
 	const char *dev;
 	const char *server_dev;
 	int ifindex;
···
 	}
 
 	return rc;
+}
+
+static int set_dsfield(int sd, int version, int dsfield)
+{
+	if (!dsfield)
+		return 0;
+
+	switch (version) {
+	case AF_INET:
+		if (setsockopt(sd, SOL_IP, IP_TOS, &dsfield,
+			       sizeof(dsfield)) < 0) {
+			log_err_errno("setsockopt(IP_TOS)");
+			return -1;
+		}
+		break;
+
+	case AF_INET6:
+		if (setsockopt(sd, SOL_IPV6, IPV6_TCLASS, &dsfield,
+			       sizeof(dsfield)) < 0) {
+			log_err_errno("setsockopt(IPV6_TCLASS)");
+			return -1;
+		}
+		break;
+
+	default:
+		log_error("Invalid address family\n");
+		return -1;
+	}
+
+	return 0;
 }
 
 static int str_to_uint(const char *str, int min, int max, unsigned int *value)
···
 		       (char *)&one, sizeof(one)) < 0)
 		log_err_errno("Setting SO_BROADCAST error");
 
+	if (set_dsfield(sd, AF_INET, args->dsfield) != 0)
+		goto out_err;
+
 	if (args->dev && bind_to_device(sd, args->dev) != 0)
 		goto out_err;
 	else if (args->use_setsockopt &&
···
 		goto err;
 
 	if (set_reuseport(sd) != 0)
+		goto err;
+
+	if (set_dsfield(sd, args->version, args->dsfield) != 0)
 		goto err;
 
 	if (args->dev && bind_to_device(sd, args->dev) != 0)
···
 	if (set_reuseport(sd) != 0)
 		goto err;
 
+	if (set_dsfield(sd, args->version, args->dsfield) != 0)
+		goto err;
+
 	if (args->dev && bind_to_device(sd, args->dev) != 0)
 		goto err;
 	else if (args->use_setsockopt &&
···
 	return client_status;
 }
 
-#define GETOPT_STR  "sr:l:c:p:t:g:P:DRn:M:X:m:d:I:BN:O:SUCi6xL:0:1:2:3:Fbqf"
+#define GETOPT_STR  "sr:l:c:Q:p:t:g:P:DRn:M:X:m:d:I:BN:O:SUCi6xL:0:1:2:3:Fbqf"
 #define OPT_FORCE_BIND_KEY_IFINDEX 1001
 #define OPT_NO_BIND_KEY_IFINDEX 1002
 
···
 	"    -D|R          datagram (D) / raw (R) socket (default stream)\n"
 	"    -l addr       local address to bind to in server mode\n"
 	"    -c addr       local address to bind to in client mode\n"
+	"    -Q dsfield    DS Field value of the socket (the IP_TOS or\n"
+	"                  IPV6_TCLASS socket option)\n"
 	"    -x            configure XFRM policy on socket\n"
 	"\n"
 	"    -d dev        bind socket to given device name\n"
···
 		case 'c':
 			args.has_local_ip = 1;
 			args.client_local_addr_str = optarg;
+			break;
+		case 'Q':
+			if (str_to_uint(optarg, 0, 255, &tmp) != 0) {
+				fprintf(stderr, "Invalid DS Field\n");
+				return 1;
+			}
+			args.dsfield = tmp;
 			break;
 		case 'p':
 			if (str_to_uint(optarg, 1, 65535, &tmp) != 0) {