selftests: mptcp: add infinite map testcase

Add the single subflow test case for MP_FAIL, to test the infinite
mapping case. Use the test_linkfail value to make 128KB test files.

Add a new function reset_with_fail(), in it use 'iptables' and 'tc
action pedit' rules to produce the bit flips to trigger the checksum
failures. Set validate_checksum to enable checksums for the MP_FAIL
tests without passing the '-C' argument. Set check_invert flag to
enable the invert bytes check for the output data in check_transfer().
Instead of the file mismatch error, this test prints out the inverted
bytes.

Add a new function pedit_action_pkts() to get the numbers of the packets
edited by the tc pedit actions. Print this numbers to the output.

Also add the needed kernel configures in the selftests config file.

Suggested-by: Davide Caratti <dcaratti@redhat.com>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/tools/testing/selftests/net/mptcp/config b/tools/testing/selftests/net/mptcp/config
index d36b7da..38021a0 100644 (file)
--- a/tools/testing/selftests/net/mptcp/config
+++ b/tools/testing/selftests/net/mptcp/config
@@ -12,6 +12,9 @@ CONFIG_NF_TABLES=m
 CONFIG_NFT_COMPAT=m
 CONFIG_NETFILTER_XTABLES=m
 CONFIG_NETFILTER_XT_MATCH_BPF=m
+CONFIG_NETFILTER_XT_MATCH_LENGTH=m
+CONFIG_NETFILTER_XT_MATCH_STATISTIC=m
+CONFIG_NETFILTER_XT_TARGET_MARK=m
 CONFIG_NF_TABLES_INET=y
 CONFIG_NFT_TPROXY=m
 CONFIG_NFT_SOCKET=m
@@ -19,3 +22,8 @@ CONFIG_IP_ADVANCED_ROUTER=y
 CONFIG_IP_MULTIPLE_TABLES=y
 CONFIG_IP_NF_TARGET_REJECT=m
 CONFIG_IPV6_MULTIPLE_TABLES=y
+CONFIG_NET_ACT_CSUM=m
+CONFIG_NET_ACT_PEDIT=m
+CONFIG_NET_CLS_ACT=y
+CONFIG_NET_CLS_FW=m
+CONFIG_NET_SCH_INGRESS=m

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 9eb4d88..34152a5 100755 (executable)
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -266,6 +266,58 @@ reset_with_allow_join_id0()
        ip netns exec $ns2 sysctl -q net.mptcp.allow_join_initial_addr_port=$ns2_enable
 }
 
+# Modify TCP payload without corrupting the TCP packet
+#
+# This rule inverts a 8-bit word at byte offset 148 for the 2nd TCP ACK packets
+# carrying enough data.
+# Once it is done, the TCP Checksum field is updated so the packet is still
+# considered as valid at the TCP level.
+# Because the MPTCP checksum, covering the TCP options and data, has not been
+# updated, the modification will be detected and an MP_FAIL will be emitted:
+# what we want to validate here without corrupting "random" MPTCP options.
+#
+# To avoid having tc producing this pr_info() message for each TCP ACK packets
+# not carrying enough data:
+#
+#     tc action pedit offset 162 out of bounds
+#
+# Netfilter is used to mark packets with enough data.
+reset_with_fail()
+{
+       reset "${1}" || return 1
+
+       ip netns exec $ns1 sysctl -q net.mptcp.checksum_enabled=1
+       ip netns exec $ns2 sysctl -q net.mptcp.checksum_enabled=1
+
+       check_invert=1
+       validate_checksum=1
+       local i="$2"
+       local ip="${3:-4}"
+       local tables
+
+       tables="iptables"
+       if [ $ip -eq 6 ]; then
+               tables="ip6tables"
+       fi
+
+       ip netns exec $ns2 $tables \
+               -t mangle \
+               -A OUTPUT \
+               -o ns2eth$i \
+               -p tcp \
+               -m length --length 150:9999 \
+               -m statistic --mode nth --packet 1 --every 99999 \
+               -j MARK --set-mark 42 || exit 1
+
+       tc -n $ns2 qdisc add dev ns2eth$i clsact || exit 1
+       tc -n $ns2 filter add dev ns2eth$i egress \
+               protocol ip prio 1000 \
+               handle 42 fw \
+               action pedit munge offset 148 u8 invert \
+               pipe csum tcp \
+               index 100 || exit 1
+}
+
 fail_test()
 {
        ret=1
@@ -1199,7 +1251,7 @@ chk_join_nr()
                echo "[ ok ]"
        fi
        [ "${dump_stats}" = 1 ] && dump_stats
-       if [ $checksum -eq 1 ]; then
+       if [ $validate_checksum -eq 1 ]; then
                chk_csum_nr $csum_ns1 $csum_ns2
                chk_fail_nr $fail_nr $fail_nr
                chk_rst_nr $rst_nr $rst_nr
@@ -2590,6 +2642,21 @@ fastclose_tests()
        fi
 }
 
+pedit_action_pkts()
+{
+       tc -n $ns2 -j -s action show action pedit index 100 | \
+               sed 's/.*"packets":\([0-9]\+\),.*/\1/'
+}
+
+fail_tests()
+{
+       # single subflow
+       if reset_with_fail "Infinite map" 1; then
+               run_tests $ns1 $ns2 10.0.1.1 128
+               chk_join_nr 0 0 0 +1 +0 1 0 1 "$(pedit_action_pkts)"
+       fi
+}
+
 implicit_tests()
 {
        # userspace pm type prevents add_addr
@@ -2658,6 +2725,7 @@ all_tests_sorted=(
        d@deny_join_id0_tests
        m@fullmesh_tests
        z@fastclose_tests
+       F@fail_tests
        I@implicit_tests
 )