Selftests are supposed to run on any kernels, including the old ones not supporting all MPTCP features.

New functions are now available to easily detect if a certain feature is missing by looking at kallsyms.

These new helpers are going to be used in the following commits. In order to ease the backport of such future patches, it would be good if this patch is backported up to the introduction of MPTCP selftests, hence the Fixes tag below: this type of check was supposed to be done from the beginning.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368 Fixes: 048d19d444be ("mptcp: add basic kselftest for mptcp") Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts matthieu.baerts@tessares.net --- tools/testing/selftests/net/mptcp/config | 1 + tools/testing/selftests/net/mptcp/mptcp_lib.sh | 38 ++++++++++++++++++++++++++ 2 files changed, 39 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/config b/tools/testing/selftests/net/mptcp/config index 38021a0dd527..6032f9b23c4c 100644 --- a/tools/testing/selftests/net/mptcp/config +++ b/tools/testing/selftests/net/mptcp/config @@ -1,3 +1,4 @@ +CONFIG_KALLSYMS=y CONFIG_MPTCP=y CONFIG_IPV6=y CONFIG_MPTCP_IPV6=y diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh index 3286536b79d5..29b65f4b73b2 100644 --- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh @@ -38,3 +38,41 @@ mptcp_lib_check_mptcp() { exit ${KSFT_SKIP} fi } + +mptcp_lib_check_kallsyms() { + if ! mptcp_lib_has_file "/proc/kallsyms"; then + echo "SKIP: CONFIG_KALLSYMS is missing" + exit ${KSFT_SKIP} + fi +} + +# Internal: use mptcp_lib_kallsyms_has() instead +__mptcp_lib_kallsyms_has() { + local sym="${1}" + + mptcp_lib_check_kallsyms + + grep -q " ${sym}" /proc/kallsyms +} + +# $1: part of a symbol to look at, add '$' at the end for full name +mptcp_lib_kallsyms_has() { + local sym="${1}" + + if __mptcp_lib_kallsyms_has "${sym}"; then + return 0 + fi + + mptcp_lib_fail_if_expected_feature "${sym} symbol not found" +} + +# $1: part of a symbol to look at, add '$' at the end for full name +mptcp_lib_kallsyms_doesnt_have() { + local sym="${1}" + + if ! __mptcp_lib_kallsyms_has "${sym}"; then + return 0 + fi + + mptcp_lib_fail_if_expected_feature "${sym} symbol has been found" +}

Selftests are supposed to run on any kernels, including the old ones not supporting all MPTCP features.

One of them is the full support of disconnections from the userspace introduced by commit b29fcfb54cd7 ("mptcp: full disconnect implementation").

It is possible to look for "mptcp_pm_data_reset" in kallsyms because a preparation patch added it to ease the introduction of the mentioned feature.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368 Fixes: 05be5e273c84 ("selftests: mptcp: add disconnect tests") Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts matthieu.baerts@tessares.net --- tools/testing/selftests/net/mptcp/mptcp_connect.sh | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.sh b/tools/testing/selftests/net/mptcp/mptcp_connect.sh index f9c36c6929cc..895114fb6832 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh @@ -797,6 +797,11 @@ run_tests_disconnect() local old_cin=$cin local old_sin=$sin

+ if ! mptcp_lib_kallsyms_has "mptcp_pm_data_reset$"; then + echo "INFO: Full disconnect not supported: SKIP" + return + fi + cat $cin $cin $cin > "$cin".disconnect

# force do_transfer to cope with the multiple tranmissions

Selftests are supposed to run on any kernels, including the old ones not supporting all MPTCP features.

One of them is the listen diag dump support introduced by commit 4fa39b701ce9 ("mptcp: listen diag dump support").

It looks like there is no good pre-check to do here, i.e. dedicated function available in kallsyms. Instead, we try to get info if nothing is returned, the test is marked as skipped.

That's not ideal because something could be wrong with the feature and instead of reporting an error, the test could be marked as skipped. If we know in advanced that the feature is supposed to be supported, the tester can set SELFTESTS_MPTCP_LIB_EXPECT_ALL_FEATURES env var to 1: in this case the test will report an error instead of marking the test as skipped if nothing is returned.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368 Fixes: f2ae0fa68e28 ("selftests/mptcp: add diag listen tests") Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts matthieu.baerts@tessares.net --- tools/testing/selftests/net/mptcp/diag.sh | 42 +++++++++++++------------------ 1 file changed, 17 insertions(+), 25 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh index 4eacdb1ab962..4a6165389b74 100755 --- a/tools/testing/selftests/net/mptcp/diag.sh +++ b/tools/testing/selftests/net/mptcp/diag.sh @@ -55,16 +55,20 @@ __chk_nr() { local command="$1" local expected=$2 - local msg nr + local msg="$3" + local skip="${4:-SKIP}" + local nr

- shift 2 - msg=$* nr=$(eval $command)

printf "%-50s" "$msg" if [ $nr != $expected ]; then - echo "[ fail ] expected $expected found $nr" - ret=$test_cnt + if [ $nr = "$skip" ] && ! mptcp_lib_expect_all_features; then + echo "[ skip ] Feature probably not supported" + else + echo "[ fail ] expected $expected found $nr" + ret=$test_cnt + fi else echo "[ ok ]" fi @@ -76,12 +80,12 @@ __chk_msk_nr() local condition=$1 shift 1

- __chk_nr "ss -inmHMN $ns | $condition" $* + __chk_nr "ss -inmHMN $ns | $condition" "$@" }

chk_msk_nr() { - __chk_msk_nr "grep -c token:" $* + __chk_msk_nr "grep -c token:" "$@" }

wait_msk_nr() @@ -119,37 +123,26 @@ wait_msk_nr()

chk_msk_fallback_nr() { - __chk_msk_nr "grep -c fallback" $* + __chk_msk_nr "grep -c fallback" "$@" }

chk_msk_remote_key_nr() { - __chk_msk_nr "grep -c remote_key" $* + __chk_msk_nr "grep -c remote_key" "$@" }

__chk_listen() { local filter="$1" local expected=$2 + local msg="$3"

- shift 2 - msg=$* - - nr=$(ss -N $ns -Ml "$filter" | grep -c LISTEN) - printf "%-50s" "$msg" - - if [ $nr != $expected ]; then - echo "[ fail ] expected $expected found $nr" - ret=$test_cnt - else - echo "[ ok ]" - fi + __chk_nr "ss -N $ns -Ml '$filter' | grep -c LISTEN" "$expected" "$msg" 0 }

chk_msk_listen() { lport=$1 - local msg="check for listen socket"

# destination port search should always return empty list __chk_listen "dport $lport" 0 "listen match for dport $lport" @@ -167,10 +160,9 @@ chk_msk_listen() chk_msk_inuse() { local expected=$1 + local msg="$2" local listen_nr

- shift 1 - listen_nr=$(ss -N "${ns}" -Ml | grep -c LISTEN) expected=$((expected + listen_nr))

@@ -181,7 +173,7 @@ chk_msk_inuse() sleep 0.1 done

- __chk_nr get_msk_inuse $expected $* + __chk_nr get_msk_inuse $expected "$msg" }

# $1: ns, $2: port

Selftests are supposed to run on any kernels, including the old ones not supporting all MPTCP features.

One of them is the checks of the default limits returned by the MPTCP in-kernel path-manager. The default values have been modified by commit 72bcbc46a5c3 ("mptcp: increase default max additional subflows to 2"). Instead of comparing with hardcoded values, we can get the default one and compare with them.

Note that if we expect to have the latest version, we continue to check the hardcoded values to avoid unexpected behaviour changes.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368 Fixes: eedbc685321b ("selftests: add PM netlink functional tests") Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts matthieu.baerts@tessares.net --- tools/testing/selftests/net/mptcp/pm_netlink.sh | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/pm_netlink.sh b/tools/testing/selftests/net/mptcp/pm_netlink.sh index 32f7533e0919..664cafc60705 100755 --- a/tools/testing/selftests/net/mptcp/pm_netlink.sh +++ b/tools/testing/selftests/net/mptcp/pm_netlink.sh @@ -73,8 +73,12 @@ check() }

check "ip netns exec $ns1 ./pm_nl_ctl dump" "" "defaults addr list" -check "ip netns exec $ns1 ./pm_nl_ctl limits" "accept 0 + +default_limits="$(ip netns exec $ns1 ./pm_nl_ctl limits)" +if mptcp_lib_expect_all_features; then + check "ip netns exec $ns1 ./pm_nl_ctl limits" "accept 0 subflows 2" "defaults limits" +fi

ip netns exec $ns1 ./pm_nl_ctl add 10.0.1.1 ip netns exec $ns1 ./pm_nl_ctl add 10.0.1.2 flags subflow dev lo @@ -121,12 +125,10 @@ ip netns exec $ns1 ./pm_nl_ctl flush check "ip netns exec $ns1 ./pm_nl_ctl dump" "" "flush addrs"

ip netns exec $ns1 ./pm_nl_ctl limits 9 1 -check "ip netns exec $ns1 ./pm_nl_ctl limits" "accept 0 -subflows 2" "rcv addrs above hard limit" +check "ip netns exec $ns1 ./pm_nl_ctl limits" "$default_limits" "rcv addrs above hard limit"

ip netns exec $ns1 ./pm_nl_ctl limits 1 9 -check "ip netns exec $ns1 ./pm_nl_ctl limits" "accept 0 -subflows 2" "subflows above hard limit" +check "ip netns exec $ns1 ./pm_nl_ctl limits" "$default_limits" "subflows above hard limit"

ip netns exec $ns1 ./pm_nl_ctl limits 8 8 check "ip netns exec $ns1 ./pm_nl_ctl limits" "accept 8

Selftests are supposed to run on any kernels, including the old ones not supporting all MPTCP features.

One of them is the getsockopt(SOL_MPTCP) to get info about the MPTCP connections introduced by commit 55c42fa7fa33 ("mptcp: add MPTCP_INFO getsockopt") and the following ones.

We cannot guess in advance which sizes the kernel will returned: older kernel can returned smaller sizes, e.g. recently the tcp_info structure has been modified in commit 71fc704768f6 ("tcp: add rcv_wnd and plb_rehash to TCP_INFO") where a new field has been added.

The userspace can also expect a smaller size if it is compiled with old uAPI kernel headers.

So for these sizes, we can only check if they are above a certain threshold, 0 for the moment. We can also only compared sizes with the ones set by the kernel.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368 Fixes: ce9979129a0b ("selftests: mptcp: add mptcp getsockopt test cases") Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts matthieu.baerts@tessares.net --- tools/testing/selftests/net/mptcp/mptcp_sockopt.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c index ae61f39556ca..b35148edbf02 100644 --- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c +++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c @@ -87,6 +87,10 @@ struct so_state { uint64_t tcpi_rcv_delta; };

+#ifndef MIN +#define MIN(a, b) ((a) < (b) ? (a) : (b)) +#endif + static void die_perror(const char *msg) { perror(msg); @@ -349,13 +353,14 @@ static void do_getsockopt_tcp_info(struct so_state *s, int fd, size_t r, size_t xerror("getsockopt MPTCP_TCPINFO (tries %d, %m)");

assert(olen <= sizeof(ti)); - assert(ti.d.size_user == ti.d.size_kernel); - assert(ti.d.size_user == sizeof(struct tcp_info)); + assert(ti.d.size_kernel > 0); + assert(ti.d.size_user == + MIN(ti.d.size_kernel, sizeof(struct tcp_info))); assert(ti.d.num_subflows == 1);

assert(olen > (socklen_t)sizeof(struct mptcp_subflow_data)); olen -= sizeof(struct mptcp_subflow_data); - assert(olen == sizeof(struct tcp_info)); + assert(olen == ti.d.size_user);

if (ti.ti[0].tcpi_bytes_sent == w && ti.ti[0].tcpi_bytes_received == r) @@ -401,13 +406,14 @@ static void do_getsockopt_subflow_addrs(int fd) die_perror("getsockopt MPTCP_SUBFLOW_ADDRS");

assert(olen <= sizeof(addrs)); - assert(addrs.d.size_user == addrs.d.size_kernel); - assert(addrs.d.size_user == sizeof(struct mptcp_subflow_addrs)); + assert(addrs.d.size_kernel > 0); + assert(addrs.d.size_user == + MIN(addrs.d.size_kernel, sizeof(struct mptcp_subflow_addrs))); assert(addrs.d.num_subflows == 1);

assert(olen > (socklen_t)sizeof(struct mptcp_subflow_data)); olen -= sizeof(struct mptcp_subflow_data); - assert(olen == sizeof(struct mptcp_subflow_addrs)); + assert(olen == addrs.d.size_user);

llen = sizeof(local); ret = getsockname(fd, (struct sockaddr *)&local, &llen);

Selftests are supposed to run on any kernels, including the old ones not supporting all MPTCP features.

One of them is TCP_INQ cmsg support introduced in commit 2c9e77659a0c ("mptcp: add TCP_INQ cmsg support").

It is possible to look for "mptcp_ioctl" in kallsyms because it was needed to introduce the mentioned feature. We can skip these tests and not set TCPINQ option if the feature is not supported.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368 Fixes: 5cbd886ce2a9 ("selftests: mptcp: add TCP_INQ support") Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts matthieu.baerts@tessares.net --- tools/testing/selftests/net/mptcp/mptcp_sockopt.sh | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh index 1d4ae8792227..f295a371ff14 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh @@ -187,9 +187,14 @@ do_transfer() local_addr="0.0.0.0" fi

+ cmsg="TIMESTAMPNS" + if mptcp_lib_kallsyms_has "mptcp_ioctl$"; then + cmsg+=",TCPINQ" + fi + timeout ${timeout_test} \ ip netns exec ${listener_ns} \ - $mptcp_connect -t ${timeout_poll} -l -M 1 -p $port -s ${srv_proto} -c TIMESTAMPNS,TCPINQ \ + $mptcp_connect -t ${timeout_poll} -l -M 1 -p $port -s ${srv_proto} -c "${cmsg}" \ ${local_addr} < "$sin" > "$sout" & local spid=$!

@@ -197,7 +202,7 @@ do_transfer()

timeout ${timeout_test} \ ip netns exec ${connector_ns} \ - $mptcp_connect -t ${timeout_poll} -M 2 -p $port -s ${cl_proto} -c TIMESTAMPNS,TCPINQ \ + $mptcp_connect -t ${timeout_poll} -M 2 -p $port -s ${cl_proto} -c "${cmsg}" \ $connect_addr < "$cin" > "$cout" &

local cpid=$! @@ -313,6 +318,11 @@ do_tcpinq_tests() { local lret=0

+ if ! mptcp_lib_kallsyms_has "mptcp_ioctl$"; then + echo "INFO: TCP_INQ not supported: SKIP" + return + fi + local args for args in "-t tcp" "-r tcp"; do do_tcpinq_test $args

Selftests are supposed to run on any kernels, including the old ones not supporting all MPTCP features.

One of them is the MPTCP Userspace PM introduced by commit 4638de5aefe5 ("mptcp: handle local addrs announced by userspace PMs").

We can skip all these tests if the feature is not supported simply by looking for the MPTCP pm_type's sysctl knob.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368 Fixes: 259a834fadda ("selftests: mptcp: functional tests for the userspace PM type") Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts matthieu.baerts@tessares.net --- tools/testing/selftests/net/mptcp/userspace_pm.sh | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/userspace_pm.sh b/tools/testing/selftests/net/mptcp/userspace_pm.sh index 192ab818f292..38a1d34f7b4d 100755 --- a/tools/testing/selftests/net/mptcp/userspace_pm.sh +++ b/tools/testing/selftests/net/mptcp/userspace_pm.sh @@ -5,6 +5,11 @@

mptcp_lib_check_mptcp

+if ! mptcp_lib_has_file '/proc/sys/net/mptcp/pm_type'; then + echo "userspace pm tests are not supported by the kernel: SKIP" + exit ${KSFT_SKIP} +fi + ip -Version > /dev/null 2>&1 if [ $? -ne 0 ];then echo "SKIP: Cannot not run test without ip tool"