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+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Test for DSCP prioritization in the router.
+#
+# With ip_forward_update_priority disabled, the packets are expected to keep
+# their DSCP (which in this test uses only values 0..7) intact as they are
+# forwarded by the switch. That is verified at $h2. ICMP responses are formed
+# with the same DSCP as the requests, and likewise pass through the switch
+# intact, which is verified at $h1.
+#
+# With ip_forward_update_priority enabled, router reprioritizes the packets
+# according to the table in reprioritize(). Thus, say, DSCP 7 maps to priority
+# 4, which on egress maps back to DSCP 4. The response packet then gets
+# reprioritized to 6, getting DSCP 6 on egress.
+#
+# +----------------------+ +----------------------+
+# | H1 | | H2 |
+# | + $h1 | | $h2 + |
+# | | 192.0.2.1/28 | | 192.0.2.18/28 | |
+# +----|-----------------+ +----------------|-----+
+# | |
+# +----|----------------------------------------------------------------|-----+
+# | SW | | |
+# | + $swp1 $swp2 + |
+# | 192.0.2.2/28 192.0.2.17/28 |
+# | APP=0,5,0 .. 7,5,7 APP=0,5,0 .. 7,5,7 |
+# +---------------------------------------------------------------------------+
+
+ALL_TESTS="
+ ping_ipv4
+ test_update
+ test_no_update
+"
+
+lib_dir=$(dirname $0)/../../../net/forwarding
+
+NUM_NETIFS=4
+source $lib_dir/lib.sh
+
+reprioritize()
+{
+ local in=$1; shift
+
+ # This is based on rt_tos2priority in include/net/route.h. Assuming 1:1
+ # mapping between priorities and TOS, it yields a new priority for a
+ # packet with ingress priority of $in.
+ local -a reprio=(0 0 2 2 6 6 4 4)
+
+ echo ${reprio[$in]}
+}
+
+h1_create()
+{
+ local dscp;
+
+ simple_if_init $h1 192.0.2.1/28
+ tc qdisc add dev $h1 clsact
+ dscp_capture_install $h1 0
+ ip route add vrf v$h1 192.0.2.16/28 via 192.0.2.2
+}
+
+h1_destroy()
+{
+ ip route del vrf v$h1 192.0.2.16/28 via 192.0.2.2
+ dscp_capture_uninstall $h1 0
+ tc qdisc del dev $h1 clsact
+ simple_if_fini $h1 192.0.2.1/28
+}
+
+h2_create()
+{
+ simple_if_init $h2 192.0.2.18/28
+ tc qdisc add dev $h2 clsact
+ dscp_capture_install $h2 0
+ ip route add vrf v$h2 192.0.2.0/28 via 192.0.2.17
+}
+
+h2_destroy()
+{
+ ip route del vrf v$h2 192.0.2.0/28 via 192.0.2.17
+ dscp_capture_uninstall $h2 0
+ tc qdisc del dev $h2 clsact
+ simple_if_fini $h2 192.0.2.18/28
+}
+
+dscp_map()
+{
+ local base=$1; shift
+
+ for prio in {0..7}; do
+ echo app=$prio,5,$((base + prio))
+ done
+}
+
+switch_create()
+{
+ simple_if_init $swp1 192.0.2.2/28
+ __simple_if_init $swp2 v$swp1 192.0.2.17/28
+
+ lldptool -T -i $swp1 -V APP $(dscp_map 0) >/dev/null
+ lldptool -T -i $swp2 -V APP $(dscp_map 0) >/dev/null
+ lldpad_app_wait_set $swp1
+ lldpad_app_wait_set $swp2
+}
+
+switch_destroy()
+{
+ lldptool -T -i $swp2 -V APP -d $(dscp_map 0) >/dev/null
+ lldptool -T -i $swp1 -V APP -d $(dscp_map 0) >/dev/null
+ lldpad_app_wait_del
+
+ __simple_if_fini $swp2 192.0.2.17/28
+ simple_if_fini $swp1 192.0.2.2/28
+}
+
+setup_prepare()
+{
+ h1=${NETIFS[p1]}
+ swp1=${NETIFS[p2]}
+
+ swp2=${NETIFS[p3]}
+ h2=${NETIFS[p4]}
+
+ vrf_prepare
+
+ sysctl_set net.ipv4.ip_forward_update_priority 1
+ h1_create
+ h2_create
+ switch_create
+}
+
+cleanup()
+{
+ pre_cleanup
+
+ switch_destroy
+ h2_destroy
+ h1_destroy
+ sysctl_restore net.ipv4.ip_forward_update_priority
+
+ vrf_cleanup
+}
+
+ping_ipv4()
+{
+ ping_test $h1 192.0.2.18
+}
+
+dscp_ping_test()
+{
+ local vrf_name=$1; shift
+ local sip=$1; shift
+ local dip=$1; shift
+ local prio=$1; shift
+ local reprio=$1; shift
+ local dev1=$1; shift
+ local dev2=$1; shift
+
+ local prio2=$($reprio $prio) # ICMP Request egress prio
+ local prio3=$($reprio $prio2) # ICMP Response egress prio
+
+ local dscp=$((prio << 2)) # ICMP Request ingress DSCP
+ local dscp2=$((prio2 << 2)) # ICMP Request egress DSCP
+ local dscp3=$((prio3 << 2)) # ICMP Response egress DSCP
+
+ RET=0
+
+ eval "local -A dev1_t0s=($(dscp_fetch_stats $dev1 0))"
+ eval "local -A dev2_t0s=($(dscp_fetch_stats $dev2 0))"
+
+ ip vrf exec $vrf_name \
+ ${PING} -Q $dscp ${sip:+-I $sip} $dip \
+ -c 10 -i 0.1 -w 2 &> /dev/null
+
+ eval "local -A dev1_t1s=($(dscp_fetch_stats $dev1 0))"
+ eval "local -A dev2_t1s=($(dscp_fetch_stats $dev2 0))"
+
+ for i in {0..7}; do
+ local dscpi=$((i << 2))
+ local expect2=0
+ local expect3=0
+
+ if ((i == prio2)); then
+ expect2=10
+ fi
+ if ((i == prio3)); then
+ expect3=10
+ fi
+
+ local delta=$((dev2_t1s[$i] - dev2_t0s[$i]))
+ ((expect2 == delta))
+ check_err $? "DSCP $dscpi@$dev2: Expected to capture $expect2 packets, got $delta."
+
+ delta=$((dev1_t1s[$i] - dev1_t0s[$i]))
+ ((expect3 == delta))
+ check_err $? "DSCP $dscpi@$dev1: Expected to capture $expect3 packets, got $delta."
+ done
+
+ log_test "DSCP rewrite: $dscp-(prio $prio2)-$dscp2-(prio $prio3)-$dscp3"
+}
+
+__test_update()
+{
+ local update=$1; shift
+ local reprio=$1; shift
+
+ sysctl_restore net.ipv4.ip_forward_update_priority
+ sysctl_set net.ipv4.ip_forward_update_priority $update
+
+ for prio in {0..7}; do
+ dscp_ping_test v$h1 192.0.2.1 192.0.2.18 $prio $reprio $h1 $h2
+ done
+}
+
+test_update()
+{
+ __test_update 1 reprioritize
+}
+
+test_no_update()
+{
+ __test_update 0 echo
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+tests_run
+
+exit $EXIT_STATUS