After a few years of increasing test coverage in the MPTCP selftests, we realised [1] the last version of the selftests is supposed to run on old kernels without issues. Supporting older versions is not that easy for this MPTCP case: these selftests are often validating the internals by checking packets that are exchanged, when some MIB counters are incremented after some actions, how connections are getting opened and closed in some cases, etc. In other words, it is not limited to the socket interface between the userspace and the kernelspace. In addition to that, the current MPTCP selftests run a lot of different sub-tests but the TAP13 protocol used in the selftests don't support sub-tests: one failure in sub-tests implies that the whole selftest is seen as failed at the end because sub-tests are not tracked. It is then important to skip sub-tests not supported by old kernels. To minimise the modifications and reduce the complexity to support old versions, the idea is to look at external signs and skip the whole selftest or just some sub-tests before starting them. This cannot be applied in all cases. Similar to the second part, this third one focuses on marking different sub-tests as skipped if some MPTCP features are not supported. This time, only in "mptcp_join.sh" selftest, the remaining one, is modified. Several techniques are used here to achieve this task: - Before starting some tests: - Check if a file (sysctl knob) is present: that's what patch 12/17 is doing for the userspace PM feature. - Check if a required kernel symbol is present in /proc/kallsyms: patches 9, 10, 14 and 15/17 are using this technique. - Check if it is possible to setup a particular network environment requiring Netfilter or TC: if the preparation step fail, the linked sub-test is marked as skipped. Patch 5/17 is doing that. - Check if a MIB counter is available: patches 7 and 13/17 do that. - Check if the kernel version is newer than a specific one: patch 1/17 adds some helpers in mptcp_lib.sh to ease its use. That's not ideal and it is only used as last resort but as mentioned above, it is important to skip tests if they are not supported not to have the whole selftest always being marked as failed on old kernels. Patches 11 and 17/17 are checking the kernel version. An alternative would be to ignore the results for some sub-tests but that's not ideal too. Note that SELFTESTS_MPTCP_LIB_NO_KVERSION_CHECK env var can be set to 1 not to skip these tests if the running kernel doesn't have a supported version. - After having launched the tests: - Adapt the expectations depending on the presence of a kernel symbol (patch 6/17) or a kernel version (patch 8/17). - Check is a MIB counter is available and skip the verification if not. Patch 4/17 is using this technique. Before skipping tests, SELFTESTS_MPTCP_LIB_EXPECT_ALL_FEATURES env var value is checked: if it is set to 1, the test is marked as "failed" instead of "skipped". MPTCP public CI expects to have all features supported and it sets this env var to 1 to catch regressions in these new checks. Patch 2/17 uses 'iptables-legacy' if available because it might be needed when using an older kernel not supporting iptables-nft. Patch 3/17 adds some helpers used in the other patches mentioned to easily mark sub-tests as skipped. Patch 16/17 uniforms MPTCP Join "listener" tests: it was imported code from userspace_pm.sh but without using the "code style" and ways of using tools and printing messages from MPTCP Join selftest. Link: https://lore.kernel.org/stable/CA+G9fYtDGpgT4dckXD-y-N92nqUxuvue_7AtDdBcHrbOMsDZLg@xxxxxxxxxxxxxx/ [1] Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368 Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx> --- Note that it is supposed to be the last series on this subject for -net. Also, this will conflict with commit 0639fa230a21 ("selftests: mptcp: add explicit check for new mibs") that is currently in net-next but not in -net. Here is the resolution. It is a bit long but you will see, it is simple: take the version from -net with get_counter() and for the last one, move the new call to chk_rm_tx_nr() inside the 'if' statement: ------------------- 8< ------------------- diff --cc tools/testing/selftests/net/mptcp/mptcp_join.sh index 0ae8cafde439,85474e029784..bd47cdc2bd15 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@@ -1360,27 -1265,23 +1355,25 @@@ chk_fclose_nr( fi printf "%-${nr_blank}s %s" " " "ctx" - count=$(ip netns exec $ns_tx nstat -as | grep MPTcpExtMPFastcloseTx | awk '{print $2}') - [ -z "$count" ] && count=0 - [ "$count" != "$fclose_tx" ] && extra_msg="$extra_msg,tx=$count" - if [ "$count" != "$fclose_tx" ]; then + count=$(get_counter ${ns_tx} "MPTcpExtMPFastcloseTx") + if [ -z "$count" ]; then + echo -n "[skip]" + elif [ "$count" != "$fclose_tx" ]; then + extra_msg="$extra_msg,tx=$count" echo "[fail] got $count MP_FASTCLOSE[s] TX expected $fclose_tx" fail_test - dump_stats=1 else echo -n "[ ok ]" fi echo -n " - fclzrx" - count=$(ip netns exec $ns_rx nstat -as | grep MPTcpExtMPFastcloseRx | awk '{print $2}') - [ -z "$count" ] && count=0 - [ "$count" != "$fclose_rx" ] && extra_msg="$extra_msg,rx=$count" - if [ "$count" != "$fclose_rx" ]; then + count=$(get_counter ${ns_rx} "MPTcpExtMPFastcloseRx") + if [ -z "$count" ]; then + echo -n "[skip]" + elif [ "$count" != "$fclose_rx" ]; then + extra_msg="$extra_msg,rx=$count" echo "[fail] got $count MP_FASTCLOSE[s] RX expected $fclose_rx" fail_test - dump_stats=1 else echo -n "[ ok ]" fi @@@ -1408,25 -1306,21 +1398,23 @@@ chk_rst_nr( fi printf "%-${nr_blank}s %s" " " "rtx" - count=$(ip netns exec $ns_tx nstat -as | grep MPTcpExtMPRstTx | awk '{print $2}') - [ -z "$count" ] && count=0 - if [ $count -lt $rst_tx ]; then + count=$(get_counter ${ns_tx} "MPTcpExtMPRstTx") + if [ -z "$count" ]; then + echo -n "[skip]" + elif [ $count -lt $rst_tx ]; then echo "[fail] got $count MP_RST[s] TX expected $rst_tx" fail_test - dump_stats=1 else echo -n "[ ok ]" fi echo -n " - rstrx " - count=$(ip netns exec $ns_rx nstat -as | grep MPTcpExtMPRstRx | awk '{print $2}') - [ -z "$count" ] && count=0 - if [ "$count" -lt "$rst_rx" ]; then + count=$(get_counter ${ns_rx} "MPTcpExtMPRstRx") + if [ -z "$count" ]; then + echo -n "[skip]" + elif [ "$count" -lt "$rst_rx" ]; then echo "[fail] got $count MP_RST[s] RX expected $rst_rx" fail_test - dump_stats=1 else echo -n "[ ok ]" fi @@@ -1441,28 -1333,23 +1427,25 @@@ chk_infi_nr( local infi_tx=$1 local infi_rx=$2 local count - local dump_stats printf "%-${nr_blank}s %s" " " "itx" - count=$(ip netns exec $ns2 nstat -as | grep InfiniteMapTx | awk '{print $2}') - [ -z "$count" ] && count=0 - if [ "$count" != "$infi_tx" ]; then + count=$(get_counter ${ns2} "MPTcpExtInfiniteMapTx") + if [ -z "$count" ]; then + echo -n "[skip]" + elif [ "$count" != "$infi_tx" ]; then echo "[fail] got $count infinite map[s] TX expected $infi_tx" fail_test - dump_stats=1 else echo -n "[ ok ]" fi echo -n " - infirx" - count=$(ip netns exec $ns1 nstat -as | grep InfiniteMapRx | awk '{print $2}') - [ -z "$count" ] && count=0 - if [ "$count" != "$infi_rx" ]; then + count=$(get_counter ${ns1} "MPTcpExtInfiniteMapRx") + if [ -z "$count" ]; then + echo "[skip]" + elif [ "$count" != "$infi_rx" ]; then echo "[fail] got $count infinite map[s] RX expected $infi_rx" fail_test - dump_stats=1 else echo "[ ok ]" fi @@@ -1491,13 -1375,11 +1471,12 @@@ chk_join_nr( fi printf "%03u %-36s %s" "${TEST_COUNT}" "${title}" "syn" - count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinSynRx | awk '{print $2}') - [ -z "$count" ] && count=0 - if [ "$count" != "$syn_nr" ]; then + count=$(get_counter ${ns1} "MPTcpExtMPJoinSynRx") + if [ -z "$count" ]; then + echo -n "[skip]" + elif [ "$count" != "$syn_nr" ]; then echo "[fail] got $count JOIN[s] syn expected $syn_nr" fail_test - dump_stats=1 else echo -n "[ ok ]" fi @@@ -1523,13 -1403,11 +1501,12 @@@ fi echo -n " - ack" - count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinAckRx | awk '{print $2}') - [ -z "$count" ] && count=0 - if [ "$count" != "$ack_nr" ]; then + count=$(get_counter ${ns1} "MPTcpExtMPJoinAckRx") + if [ -z "$count" ]; then + echo "[skip]" + elif [ "$count" != "$ack_nr" ]; then echo "[fail] got $count JOIN[s] ack expected $ack_nr" fail_test - dump_stats=1 else echo "[ ok ]" fi @@@ -1599,40 -1475,35 +1574,37 @@@ chk_add_nr( timeout=$(ip netns exec $ns1 sysctl -n net.mptcp.add_addr_timeout) printf "%-${nr_blank}s %s" " " "add" - count=$(ip netns exec $ns2 nstat -as MPTcpExtAddAddr | grep MPTcpExtAddAddr | awk '{print $2}') - [ -z "$count" ] && count=0 - + count=$(get_counter ${ns2} "MPTcpExtAddAddr") + if [ -z "$count" ]; then + echo -n "[skip]" # if the test configured a short timeout tolerate greater then expected # add addrs options, due to retransmissions - if [ "$count" != "$add_nr" ] && { [ "$timeout" -gt 1 ] || [ "$count" -lt "$add_nr" ]; }; then + elif [ "$count" != "$add_nr" ] && { [ "$timeout" -gt 1 ] || [ "$count" -lt "$add_nr" ]; }; then echo "[fail] got $count ADD_ADDR[s] expected $add_nr" fail_test - dump_stats=1 else echo -n "[ ok ]" fi echo -n " - echo " - count=$(ip netns exec $ns1 nstat -as MPTcpExtEchoAdd | grep MPTcpExtEchoAdd | awk '{print $2}') - [ -z "$count" ] && count=0 - if [ "$count" != "$echo_nr" ]; then + count=$(get_counter ${ns1} "MPTcpExtEchoAdd") + if [ -z "$count" ]; then + echo -n "[skip]" + elif [ "$count" != "$echo_nr" ]; then echo "[fail] got $count ADD_ADDR echo[s] expected $echo_nr" fail_test - dump_stats=1 else echo -n "[ ok ]" fi if [ $port_nr -gt 0 ]; then echo -n " - pt " - count=$(ip netns exec $ns2 nstat -as | grep MPTcpExtPortAdd | awk '{print $2}') - [ -z "$count" ] && count=0 - if [ "$count" != "$port_nr" ]; then + count=$(get_counter ${ns2} "MPTcpExtPortAdd") + if [ -z "$count" ]; then + echo "[skip]" + elif [ "$count" != "$port_nr" ]; then echo "[fail] got $count ADD_ADDR[s] with a port-number expected $port_nr" fail_test - dump_stats=1 else echo "[ ok ]" fi @@@ -1737,13 -1633,11 +1734,12 @@@ chk_rm_nr( fi printf "%-${nr_blank}s %s" " " "rm " - count=$(ip netns exec $addr_ns nstat -as MPTcpExtRmAddr | grep MPTcpExtRmAddr | awk '{print $2}') - [ -z "$count" ] && count=0 - if [ "$count" != "$rm_addr_nr" ]; then + count=$(get_counter ${addr_ns} "MPTcpExtRmAddr") + if [ -z "$count" ]; then + echo -n "[skip]" + elif [ "$count" != "$rm_addr_nr" ]; then echo "[fail] got $count RM_ADDR[s] expected $rm_addr_nr" fail_test - dump_stats=1 else echo -n "[ ok ]" fi @@@ -1767,12 -1661,12 +1763,10 @@@ else echo "[fail] got $count RM_SUBFLOW[s] expected in range [$rm_subflow_nr:$((rm_subflow_nr*2))]" fail_test - dump_stats=1 fi - return - fi - if [ "$count" != "$rm_subflow_nr" ]; then + elif [ "$count" != "$rm_subflow_nr" ]; then echo "[fail] got $count RM_SUBFLOW[s] expected $rm_subflow_nr" fail_test - dump_stats=1 else echo -n "[ ok ]" fi @@@ -1787,28 -1696,23 +1796,25 @@@ chk_prio_nr( local mp_prio_nr_tx=$1 local mp_prio_nr_rx=$2 local count - local dump_stats printf "%-${nr_blank}s %s" " " "ptx" - count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMPPrioTx | awk '{print $2}') - [ -z "$count" ] && count=0 - if [ "$count" != "$mp_prio_nr_tx" ]; then + count=$(get_counter ${ns1} "MPTcpExtMPPrioTx") + if [ -z "$count" ]; then + echo -n "[skip]" + elif [ "$count" != "$mp_prio_nr_tx" ]; then echo "[fail] got $count MP_PRIO[s] TX expected $mp_prio_nr_tx" fail_test - dump_stats=1 else echo -n "[ ok ]" fi echo -n " - prx " - count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMPPrioRx | awk '{print $2}') - [ -z "$count" ] && count=0 - if [ "$count" != "$mp_prio_nr_rx" ]; then + count=$(get_counter ${ns1} "MPTcpExtMPPrioRx") + if [ -z "$count" ]; then + echo "[skip]" + elif [ "$count" != "$mp_prio_nr_rx" ]; then echo "[fail] got $count MP_PRIO[s] RX expected $mp_prio_nr_rx" fail_test - dump_stats=1 else echo "[ ok ]" fi @@@ -2394,12 -2290,8 +2399,13 @@@ remove_tests( pm_nl_add_endpoint $ns2 10.0.4.2 flags subflow run_tests $ns1 $ns2 10.0.1.1 0 -8 -8 slow chk_join_nr 3 3 3 - chk_rm_tx_nr 0 - chk_rm_nr 0 3 simult + + if mptcp_lib_kversion_ge 5.18; then ++ chk_rm_tx_nr 0 + chk_rm_nr 0 3 simult + else + chk_rm_nr 3 3 + fi fi # addresses flush ------------------- 8< ------------------- The resolved conflicts are also visible there: https://github.com/multipath-tcp/mptcp_net-next/blob/t/DO-NOT-MERGE-git-markup-fixes-net-next/tools/testing/selftests/net/mptcp/mptcp_join.sh --- Matthieu Baerts (17): selftests: mptcp: lib: skip if not below kernel version selftests: mptcp: join: use 'iptables-legacy' if available selftests: mptcp: join: helpers to skip tests selftests: mptcp: join: skip check if MIB counter not supported selftests: mptcp: join: skip test if iptables/tc cmds fail selftests: mptcp: join: support local endpoint being tracked or not selftests: mptcp: join: skip Fastclose tests if not supported selftests: mptcp: join: support RM_ADDR for used endpoints or not selftests: mptcp: join: skip implicit tests if not supported selftests: mptcp: join: skip backup if set flag on ID not supported selftests: mptcp: join: skip fullmesh flag tests if not supported selftests: mptcp: join: skip userspace PM tests if not supported selftests: mptcp: join: skip fail tests if not supported selftests: mptcp: join: skip MPC backups tests if not supported selftests: mptcp: join: skip PM listener tests if not supported selftests: mptcp: join: uniform listener tests selftests: mptcp: join: skip mixed tests if not supported tools/testing/selftests/net/mptcp/mptcp_join.sh | 513 +++++++++++++++--------- tools/testing/selftests/net/mptcp/mptcp_lib.sh | 26 ++ 2 files changed, 354 insertions(+), 185 deletions(-) --- base-commit: 1b8975f30abffc4f74f1ba049f9042e7d8f646cc change-id: 20230609-upstream-net-20230610-mptcp-selftests-support-old-kernels-part-3-37aa5185e955 Best regards, -- Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>