selftests: mptcp: lib: get counters from nstat history

Before, 'nstat' was used to retrieve each individual counter: this means
querying 4 different sources from /proc/net and iterating over 100+
counters each time. Instead, the stats could be retrieved once, and the
output file could be parsed for each counter. Even better, such file is
already present: the nstat history file.

To be able to get this working, the nstat history file also needs to
contains zero counters too, so it is still possible to know if a counter
is missing or set to 0.

This also simplifies mptcp_connect.sh: instead of checking multiple
counters before and after a test to compute the difference, the stats
history files can be reset before each test, and nstat can display only
the difference.

mptcp_lib_get_counter() continues to work when no history file is
available: by fetching nstat directly, like before. This is the case in
diag.sh and userspace_pm.sh where there is no need to save the history
file. This is also the case in mptcp_join.sh, when 'run_tests' is
executed in the background: easier to continue fetching counters than
updating the history each time it is needed.

Note: 'nstat' is called with '-s' in mptcp_lib_nstat_get(), so this
helper can be called multiple times during the test if needed.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251114-net-next-mptcp-sft-count-cache-stats-timeout-v1-5-863cb04e1b7b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.sh b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
index 4ff2d02429d3a49127377668cb1b76f2b8ebaed3..3a804abebd2c0e9e08d3f0324a9a9a9b1d209bfa 100755 (executable)
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
@@ -389,21 +389,6 @@ do_transfer()
                mptcp_lib_nstat_init "${connector_ns}"
        fi
 
-       local stat_synrx_last_l
-       local stat_ackrx_last_l
-       local stat_cookietx_last
-       local stat_cookierx_last
-       local stat_csum_err_s
-       local stat_csum_err_c
-       local stat_tcpfb_last_l
-       stat_synrx_last_l=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableSYNRX")
-       stat_ackrx_last_l=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableACKRX")
-       stat_cookietx_last=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtSyncookiesSent")
-       stat_cookierx_last=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtSyncookiesRecv")
-       stat_csum_err_s=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtDataCsumErr")
-       stat_csum_err_c=$(mptcp_lib_get_counter "${connector_ns}" "MPTcpExtDataCsumErr")
-       stat_tcpfb_last_l=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableFallbackACK")
-
        timeout ${timeout_test} \
                ip netns exec ${listener_ns} \
                        ./mptcp_connect -t ${timeout_poll} -l -p $port -s ${srv_proto} \
@@ -458,38 +443,38 @@ do_transfer()
        rets=$?
 
        local extra=""
-       local stat_synrx_now_l
-       local stat_ackrx_now_l
-       local stat_cookietx_now
-       local stat_cookierx_now
-       local stat_ooo_now
-       local stat_tcpfb_now_l
-       stat_synrx_now_l=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableSYNRX")
-       stat_ackrx_now_l=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableACKRX")
-       stat_cookietx_now=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtSyncookiesSent")
-       stat_cookierx_now=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtSyncookiesRecv")
-       stat_ooo_now=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtTCPOFOQueue")
-       stat_tcpfb_now_l=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableFallbackACK")
-
-       expect_synrx=$((stat_synrx_last_l))
-       expect_ackrx=$((stat_ackrx_last_l))
+       local stat_synrx
+       local stat_ackrx
+       local stat_cookietx
+       local stat_cookierx
+       local stat_ooo
+       local stat_tcpfb
+       stat_synrx=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableSYNRX")
+       stat_ackrx=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableACKRX")
+       stat_cookietx=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtSyncookiesSent")
+       stat_cookierx=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtSyncookiesRecv")
+       stat_ooo=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtTCPOFOQueue")
+       stat_tcpfb=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableFallbackACK")
+
+       expect_synrx=0
+       expect_ackrx=0
 
        cookies=$(ip netns exec ${listener_ns} sysctl net.ipv4.tcp_syncookies)
        cookies=${cookies##*=}
 
        if [ ${cl_proto} = "MPTCP" ] && [ ${srv_proto} = "MPTCP" ]; then
-               expect_synrx=$((stat_synrx_last_l+connect_per_transfer))
-               expect_ackrx=$((stat_ackrx_last_l+connect_per_transfer))
+               expect_synrx=${connect_per_transfer}
+               expect_ackrx=${connect_per_transfer}
        fi
 
-       if [ ${stat_synrx_now_l} -lt ${expect_synrx} ]; then
-               mptcp_lib_pr_fail "lower MPC SYN rx (${stat_synrx_now_l})" \
+       if [ ${stat_synrx} -lt ${expect_synrx} ]; then
+               mptcp_lib_pr_fail "lower MPC SYN rx (${stat_synrx})" \
                                  "than expected (${expect_synrx})"
                retc=1
        fi
-       if [ ${stat_ackrx_now_l} -lt ${expect_ackrx} ]; then
-               if [ ${stat_ooo_now} -eq 0 ]; then
-                       mptcp_lib_pr_fail "lower MPC ACK rx (${stat_ackrx_now_l})" \
+       if [ ${stat_ackrx} -lt ${expect_ackrx} ]; then
+               if [ ${stat_ooo} -eq 0 ]; then
+                       mptcp_lib_pr_fail "lower MPC ACK rx (${stat_ackrx})" \
                                          "than expected (${expect_ackrx})"
                        rets=1
                else
@@ -503,47 +488,45 @@ do_transfer()
                csum_err_s=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtDataCsumErr")
                csum_err_c=$(mptcp_lib_get_counter "${connector_ns}" "MPTcpExtDataCsumErr")
 
-               local csum_err_s_nr=$((csum_err_s - stat_csum_err_s))
-               if [ $csum_err_s_nr -gt 0 ]; then
-                       mptcp_lib_pr_fail "server got ${csum_err_s_nr} data checksum error[s]"
+               if [ $csum_err_s -gt 0 ]; then
+                       mptcp_lib_pr_fail "server got ${csum_err_s} data checksum error[s]"
                        rets=1
                fi
 
-               local csum_err_c_nr=$((csum_err_c - stat_csum_err_c))
-               if [ $csum_err_c_nr -gt 0 ]; then
-                       mptcp_lib_pr_fail "client got ${csum_err_c_nr} data checksum error[s]"
+               if [ $csum_err_c -gt 0 ]; then
+                       mptcp_lib_pr_fail "client got ${csum_err_c} data checksum error[s]"
                        retc=1
                fi
        fi
 
-       if [ ${stat_ooo_now} -eq 0 ] && [ ${stat_tcpfb_last_l} -ne ${stat_tcpfb_now_l} ]; then
+       if [ ${stat_ooo} -eq 0 ] && [ ${stat_tcpfb} -gt 0 ]; then
                mptcp_lib_pr_fail "unexpected fallback to TCP"
                rets=1
        fi
 
        if [ $cookies -eq 2 ];then
-               if [ $stat_cookietx_last -ge $stat_cookietx_now ] ;then
+               if [ $stat_cookietx -eq 0 ] ;then
                        extra+=" WARN: CookieSent: did not advance"
                fi
-               if [ $stat_cookierx_last -ge $stat_cookierx_now ] ;then
+               if [ $stat_cookierx -eq 0 ] ;then
                        extra+=" WARN: CookieRecv: did not advance"
                fi
        else
-               if [ $stat_cookietx_last -ne $stat_cookietx_now ] ;then
+               if [ $stat_cookietx -gt 0 ] ;then
                        extra+=" WARN: CookieSent: changed"
                fi
-               if [ $stat_cookierx_last -ne $stat_cookierx_now ] ;then
+               if [ $stat_cookierx -gt 0 ] ;then
                        extra+=" WARN: CookieRecv: changed"
                fi
        fi
 
-       if [ ${stat_synrx_now_l} -gt ${expect_synrx} ]; then
+       if [ ${stat_synrx} -gt ${expect_synrx} ]; then
                extra+=" WARN: SYNRX: expect ${expect_synrx},"
-               extra+=" got ${stat_synrx_now_l} (probably retransmissions)"
+               extra+=" got ${stat_synrx} (probably retransmissions)"
        fi
-       if [ ${stat_ackrx_now_l} -gt ${expect_ackrx} ]; then
+       if [ ${stat_ackrx} -gt ${expect_ackrx} ]; then
                extra+=" WARN: ACKRX: expect ${expect_ackrx},"
-               extra+=" got ${stat_ackrx_now_l} (probably retransmissions)"
+               extra+=" got ${stat_ackrx} (probably retransmissions)"
        fi
 
        if [ $retc -eq 0 ] && [ $rets -eq 0 ]; then

diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index fa91eebdbc477f86a2977e5b01e2f19d593a883d..91ec75ddcb96074cffc02bc71db3a86932c1363a 100644 (file)
--- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
@@ -111,7 +111,7 @@ mptcp_lib_pr_nstat() {
        local hist="/tmp/${ns}.out"
 
        if [ -f "${hist}" ]; then
-               awk '{ print "  "$0 }' "${hist}"
+               awk '$2 != 0 { print "  "$0 }' "${hist}"
        else
                ip netns exec "${ns}" nstat -as | grep Tcp
        fi
@@ -388,6 +388,7 @@ mptcp_lib_is_v6() {
 mptcp_lib_nstat_init() {
        local ns="${1}"
 
+       rm -f "/tmp/${ns}."{nstat,out}
        NSTAT_HISTORY="/tmp/${ns}.nstat" ip netns exec "${ns}" nstat -n
 }
 
@@ -395,18 +396,25 @@ mptcp_lib_nstat_get() {
        local ns="${1}"
 
        # filter out non-*TCP stats, and the rate (last column)
-       NSTAT_HISTORY="/tmp/${ns}.nstat" ip netns exec "${ns}" nstat |
+       NSTAT_HISTORY="/tmp/${ns}.nstat" ip netns exec "${ns}" nstat -sz |
                grep -o ".*Tcp\S\+\s\+[0-9]\+" > "/tmp/${ns}.out"
 }
 
 # $1: ns, $2: MIB counter
+# Get the counter from the history (mptcp_lib_nstat_{init,get}()) if available.
+# If not, get the counter from nstat ignoring any history.
 mptcp_lib_get_counter() {
        local ns="${1}"
        local counter="${2}"
+       local hist="/tmp/${ns}.out"
        local count
 
-       count=$(ip netns exec "${ns}" nstat -asz "${counter}" |
-               awk 'NR==1 {next} {print $2}')
+       if [[ -s "${hist}" && "${counter}" == *"Tcp"* ]]; then
+               count=$(awk "/^${counter} / {print \$2; exit}" "${hist}")
+       else
+               count=$(ip netns exec "${ns}" nstat -asz "${counter}" |
+                       awk 'NR==1 {next} {print $2}')
+       fi
        if [ -z "${count}" ]; then
                mptcp_lib_fail_if_expected_feature "${counter} counter"
                return 1