selftests: mptcp: add link failure test case

Add a test case where a link fails with multiple subflows.
The expectation is that MPTCP will transmit any data that
could not be delivered via the failed link on another subflow.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 0d93b243695f258bdaf84ae3e7e0f67e5120775e..f841ed8186c1e30dbe3947c194211e139afdcf55 100755 (executable)
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -5,6 +5,7 @@ ret=0
 sin=""
 sout=""
 cin=""
+cinsent=""
 cout=""
 ksft_skip=4
 timeout=30
@@ -81,7 +82,7 @@ cleanup_partial()
 cleanup()
 {
        rm -f "$cin" "$cout"
-       rm -f "$sin" "$sout"
+       rm -f "$sin" "$sout" "$cinsent"
        cleanup_partial
 }
 
@@ -144,6 +145,13 @@ if [ $? -ne 0 ];then
        exit $ksft_skip
 fi
 
+print_file_err()
+{
+       ls -l "$1" 1>&2
+       echo "Trailing bytes are: "
+       tail -c 27 "$1"
+}
+
 check_transfer()
 {
        in=$1
@@ -155,6 +163,7 @@ check_transfer()
                echo "[ FAIL ] $what does not match (in, out):"
                print_file_err "$in"
                print_file_err "$out"
+               ret=1
 
                return 1
        fi
@@ -175,6 +184,17 @@ do_ping()
        fi
 }
 
+link_failure()
+{
+       ns="$1"
+
+       l=$((RANDOM%4))
+       l=$((l+1))
+
+       veth="ns1eth$l"
+       ip -net "$ns" link set "$veth" down
+}
+
 do_transfer()
 {
        listener_ns="$1"
@@ -182,9 +202,10 @@ do_transfer()
        cl_proto="$3"
        srv_proto="$4"
        connect_addr="$5"
-       rm_nr_ns1="$6"
-       rm_nr_ns2="$7"
-       speed="$8"
+       test_link_fail="$6"
+       rm_nr_ns1="$7"
+       rm_nr_ns2="$8"
+       speed="$9"
 
        port=$((10000+$TEST_COUNT))
        TEST_COUNT=$((TEST_COUNT+1))
@@ -220,7 +241,12 @@ do_transfer()
 
        sleep 1
 
-       ip netns exec ${connector_ns} $mptcp_connect -t $timeout -p $port -s ${cl_proto} $connect_addr < "$cin" > "$cout" &
+       if [ "$test_link_fail" -eq 0 ];then
+               ip netns exec ${connector_ns} $mptcp_connect -t $timeout -p $port -s ${cl_proto} $connect_addr < "$cin" > "$cout" &
+       else
+               ( cat "$cin" ; sleep 2; link_failure $listener_ns ; cat "$cin" ) | tee "$cinsent" | \
+               ip netns exec ${connector_ns} $mptcp_connect -t $timeout -p $port -s ${cl_proto} $connect_addr > "$cout" &
+       fi
        cpid=$!
 
        if [ $rm_nr_ns1 -gt 0 ]; then
@@ -265,12 +291,17 @@ do_transfer()
                ip netns exec ${connector_ns} ss -nita 1>&2 -o "dport = :$port"
 
                cat "$capout"
+               ret=1
                return 1
        fi
 
        check_transfer $sin $cout "file received by client"
        retc=$?
-       check_transfer $cin $sout "file received by server"
+       if [ "$test_link_fail" -eq 0 ];then
+               check_transfer $cin $sout "file received by server"
+       else
+               check_transfer $cinsent $sout "file received by server"
+       fi
        rets=$?
 
        if [ $retc -eq 0 ] && [ $rets -eq 0 ];then
@@ -286,13 +317,12 @@ make_file()
 {
        name=$1
        who=$2
+       size=$3
 
-       SIZE=1
-
-       dd if=/dev/urandom of="$name" bs=1024 count=$SIZE 2> /dev/null
+       dd if=/dev/urandom of="$name" bs=1024 count=$size 2> /dev/null
        echo -e "\nMPTCP_TEST_FILE_END_MARKER" >> "$name"
 
-       echo "Created $name (size $SIZE KB) containing data sent by $who"
+       echo "Created $name (size $size KB) containing data sent by $who"
 }
 
 run_tests()
@@ -300,14 +330,32 @@ run_tests()
        listener_ns="$1"
        connector_ns="$2"
        connect_addr="$3"
-       rm_nr_ns1="${4:-0}"
-       rm_nr_ns2="${5:-0}"
-       speed="${6:-fast}"
+       test_linkfail="${4:-0}"
+       rm_nr_ns1="${5:-0}"
+       rm_nr_ns2="${6:-0}"
+       speed="${7:-fast}"
        lret=0
+       oldin=""
+
+       if [ "$test_linkfail" -eq 1 ];then
+               size=$((RANDOM%1024))
+               size=$((size+1))
+               size=$((size*128))
+
+               oldin=$(mktemp)
+               cp "$cin" "$oldin"
+               make_file "$cin" "client" $size
+       fi
 
        do_transfer ${listener_ns} ${connector_ns} MPTCP MPTCP ${connect_addr} \
-               ${rm_nr_ns1} ${rm_nr_ns2} ${speed}
+               ${test_linkfail} ${rm_nr_ns1} ${rm_nr_ns2} ${speed}
        lret=$?
+
+       if [ "$test_linkfail" -eq 1 ];then
+               cp "$oldin" "$cin"
+               rm -f "$oldin"
+       fi
+
        if [ $lret -ne 0 ]; then
                ret=$lret
                return
@@ -440,10 +488,11 @@ chk_rm_nr()
 sin=$(mktemp)
 sout=$(mktemp)
 cin=$(mktemp)
+cinsent=$(mktemp)
 cout=$(mktemp)
 init
-make_file "$cin" "client"
-make_file "$sin" "server"
+make_file "$cin" "client" 1
+make_file "$sin" "server" 1
 trap cleanup EXIT
 
 run_tests $ns1 $ns2 10.0.1.1
@@ -528,12 +577,23 @@ run_tests $ns1 $ns2 10.0.1.1
 chk_join_nr "multiple subflows and signal" 3 3 3
 chk_add_nr 1 1
 
+# accept and use add_addr with additional subflows and link loss
+reset
+ip netns exec $ns1 ./pm_nl_ctl limits 0 3
+ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
+ip netns exec $ns2 ./pm_nl_ctl limits 1 3
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+ip netns exec $ns2 ./pm_nl_ctl add 10.0.4.2 flags subflow
+run_tests $ns1 $ns2 10.0.1.1 1
+chk_join_nr "multiple flows, signal, link failure" 3 3 3
+chk_add_nr 1 1
+
 # add_addr timeout
 reset_with_add_addr_timeout
 ip netns exec $ns1 ./pm_nl_ctl limits 0 1
 ip netns exec $ns2 ./pm_nl_ctl limits 1 1
 ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
-run_tests $ns1 $ns2 10.0.1.1 0 0 slow
+run_tests $ns1 $ns2 10.0.1.1 0 0 0 slow
 chk_join_nr "signal address, ADD_ADDR timeout" 1 1 1
 chk_add_nr 4 0
 
@@ -542,7 +602,7 @@ reset
 ip netns exec $ns1 ./pm_nl_ctl limits 0 1
 ip netns exec $ns2 ./pm_nl_ctl limits 0 1
 ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
-run_tests $ns1 $ns2 10.0.1.1 0 1 slow
+run_tests $ns1 $ns2 10.0.1.1 0 0 1 slow
 chk_join_nr "remove single subflow" 1 1 1
 chk_rm_nr 1 1
 
@@ -552,7 +612,7 @@ ip netns exec $ns1 ./pm_nl_ctl limits 0 2
 ip netns exec $ns2 ./pm_nl_ctl limits 0 2
 ip netns exec $ns2 ./pm_nl_ctl add 10.0.2.2 flags subflow
 ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
-run_tests $ns1 $ns2 10.0.1.1 0 2 slow
+run_tests $ns1 $ns2 10.0.1.1 0 0 2 slow
 chk_join_nr "remove multiple subflows" 2 2 2
 chk_rm_nr 2 2
 
@@ -561,7 +621,7 @@ reset
 ip netns exec $ns1 ./pm_nl_ctl limits 0 1
 ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
 ip netns exec $ns2 ./pm_nl_ctl limits 1 1
-run_tests $ns1 $ns2 10.0.1.1 1 0 slow
+run_tests $ns1 $ns2 10.0.1.1 0 1 0 slow
 chk_join_nr "remove single address" 1 1 1
 chk_add_nr 1 1
 chk_rm_nr 0 0
@@ -572,7 +632,7 @@ ip netns exec $ns1 ./pm_nl_ctl limits 0 2
 ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
 ip netns exec $ns2 ./pm_nl_ctl limits 1 2
 ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
-run_tests $ns1 $ns2 10.0.1.1 1 1 slow
+run_tests $ns1 $ns2 10.0.1.1 0 1 1 slow
 chk_join_nr "remove subflow and signal" 2 2 2
 chk_add_nr 1 1
 chk_rm_nr 1 1
@@ -584,7 +644,7 @@ ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
 ip netns exec $ns2 ./pm_nl_ctl limits 1 3
 ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
 ip netns exec $ns2 ./pm_nl_ctl add 10.0.4.2 flags subflow
-run_tests $ns1 $ns2 10.0.1.1 1 2 slow
+run_tests $ns1 $ns2 10.0.1.1 0 1 2 slow
 chk_join_nr "remove subflows and signal" 3 3 3
 chk_add_nr 1 1
 chk_rm_nr 2 2