selftests: forwarding: Add initial testing framework

Add initial framework to test packet forwarding functionality. The tests
can run on actual devices using loop-backed cables or using veth pairs.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 465 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/forwarding/.gitignore b/tools/testing/selftests/net/forwarding/.gitignore
new file mode 100644
index 000000000000..a793eef5b876
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/.gitignore
@@ -0,0 +1 @@
+forwarding.config
diff --git a/tools/testing/selftests/net/forwarding/README b/tools/testing/selftests/net/forwarding/README
new file mode 100644
index 000000000000..4a0964c42860
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/README
@@ -0,0 +1,56 @@
+Motivation
+==========
+
+One of the nice things about network namespaces is that they allow one
+to easily create and test complex environments.
+
+Unfortunately, these namespaces can not be used with actual switching
+ASICs, as their ports can not be migrated to other network namespaces
+(NETIF_F_NETNS_LOCAL) and most of them probably do not support the
+L1-separation provided by namespaces.
+
+However, a similar kind of flexibility can be achieved by using VRFs and
+by looping the switch ports together. For example:
+
+                             br0
+                              +
+               vrf-h1         |           vrf-h2
+                 +        +---+----+        +
+                 |        |        |        |
+    192.0.2.1/24 +        +        +        + 192.0.2.2/24
+               swp1     swp2     swp3     swp4
+                 +        +        +        +
+                 |        |        |        |
+                 +--------+        +--------+
+
+The VRFs act as lightweight namespaces representing hosts connected to
+the switch.
+
+This approach for testing switch ASICs has several advantages over the
+traditional method that requires multiple physical machines, to name a
+few:
+
+1. Only the device under test (DUT) is being tested without noise from
+other system.
+
+2. Ability to easily provision complex topologies. Testing bridging
+between 4-ports LAGs or 8-way ECMP requires many physical links that are
+not always available. With the VRF-based approach one merely needs to
+loopback more ports.
+
+These tests are written with switch ASICs in mind, but they can be run
+on any Linux box using veth pairs to emulate physical loopbacks.
+
+Guidelines for Writing Tests
+============================
+
+o Where possible, reuse an existing topology for different tests instead
+  of recreating the same topology.
+o Where possible, IPv6 and IPv4 addresses shall conform to RFC 3849 and
+  RFC 5737, respectively.
+o Where possible, tests shall be written so that they can be reused by
+  multiple topologies and added to lib.sh.
+o Checks shall be added to lib.sh for any external dependencies.
+o Code shall be checked using ShellCheck [1] prior to submission.
+
+1. https://www.shellcheck.net/
diff --git a/tools/testing/selftests/net/forwarding/bridge_vlan_aware.sh b/tools/testing/selftests/net/forwarding/bridge_vlan_aware.sh
new file mode 100755
index 000000000000..e6faa9548460
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/bridge_vlan_aware.sh
@@ -0,0 +1,83 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+NUM_NETIFS=4
+source lib.sh
+
+h1_create()
+{
+        simple_if_init $h1 192.0.2.1/24 2001:db8:1::1/64
+}
+
+h1_destroy()
+{
+        simple_if_fini $h1 192.0.2.1/24 2001:db8:1::1/64
+}
+
+h2_create()
+{
+        simple_if_init $h2 192.0.2.2/24 2001:db8:1::2/64
+}
+
+h2_destroy()
+{
+        simple_if_fini $h2 192.0.2.2/24 2001:db8:1::2/64
+}
+
+switch_create()
+{
+        ip link add dev br0 type bridge vlan_filtering 1 mcast_snooping 0
+
+        ip link set dev $swp1 master br0
+        ip link set dev $swp2 master br0
+
+        ip link set dev br0 up
+        ip link set dev $swp1 up
+        ip link set dev $swp2 up
+}
+
+switch_destroy()
+{
+        ip link set dev $swp2 down
+        ip link set dev $swp1 down
+
+        ip link del dev br0
+}
+
+setup_prepare()
+{
+        h1=${NETIFS[p1]}
+        swp1=${NETIFS[p2]}
+
+        swp2=${NETIFS[p3]}
+        h2=${NETIFS[p4]}
+
+        vrf_prepare
+
+        h1_create
+        h2_create
+
+        switch_create
+}
+
+cleanup()
+{
+        pre_cleanup
+
+        switch_destroy
+
+        h2_destroy
+        h1_destroy
+
+        vrf_cleanup
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+ping_test $h1 192.0.2.2
+ping6_test $h1 2001:db8:1::2
+
+exit $EXIT_STATUS
diff --git a/tools/testing/selftests/net/forwarding/config b/tools/testing/selftests/net/forwarding/config
new file mode 100644
index 000000000000..5cd2aed97958
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/config
@@ -0,0 +1,12 @@
+CONFIG_BRIDGE=m
+CONFIG_VLAN_8021Q=m
+CONFIG_BRIDGE_VLAN_FILTERING=y
+CONFIG_NET_L3_MASTER_DEV=y
+CONFIG_IPV6_MULTIPLE_TABLES=y
+CONFIG_NET_VRF=m
+CONFIG_BPF_SYSCALL=y
+CONFIG_CGROUP_BPF=y
+CONFIG_NET_CLS_FLOWER=m
+CONFIG_NET_SCH_INGRESS=m
+CONFIG_NET_ACT_GACT=m
+CONFIG_VETH=m
diff --git a/tools/testing/selftests/net/forwarding/forwarding.config.sample b/tools/testing/selftests/net/forwarding/forwarding.config.sample
new file mode 100644
index 000000000000..ab235c124f20
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/forwarding.config.sample
@@ -0,0 +1,31 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+##############################################################################
+# Topology description. p1 looped back to p2, p3 to p4 and so on.
+declare -A NETIFS
+
+NETIFS[p1]=veth0
+NETIFS[p2]=veth1
+NETIFS[p3]=veth2
+NETIFS[p4]=veth3
+NETIFS[p5]=veth4
+NETIFS[p6]=veth5
+NETIFS[p7]=veth6
+NETIFS[p8]=veth7
+
+##############################################################################
+# Defines
+
+# IPv4 ping utility name
+PING=ping
+# IPv6 ping utility name. Some distributions use 'ping' for IPv6.
+PING6=ping6
+# Packet generator. Some distributions use 'mz'.
+MZ=mausezahn
+# Time to wait after interfaces participating in the test are all UP
+WAIT_TIME=5
+# Whether to pause on failure or not.
+PAUSE_ON_FAIL=no
+# Whether to pause on cleanup or not.
+PAUSE_ON_CLEANUP=no
diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh
new file mode 100644
index 000000000000..ff6550e9ddaf
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/lib.sh
@@ -0,0 +1,282 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+##############################################################################
+# Defines
+
+# Can be overridden by the configuration file.
+PING=${PING:=ping}
+PING6=${PING6:=ping6}
+WAIT_TIME=${WAIT_TIME:=5}
+PAUSE_ON_FAIL=${PAUSE_ON_FAIL:=no}
+PAUSE_ON_CLEANUP=${PAUSE_ON_CLEANUP:=no}
+
+if [[ -f forwarding.config ]]; then
+        source forwarding.config
+fi
+
+##############################################################################
+# Sanity checks
+
+if [[ "$(id -u)" -ne 0 ]]; then
+        echo "SKIP: need root privileges"
+        exit 0
+fi
+
+tc -j &> /dev/null
+if [[ $? -ne 0 ]]; then
+        echo "SKIP: iproute2 too old, missing JSON support"
+        exit 0
+fi
+
+if [[ ! -x "$(command -v jq)" ]]; then
+        echo "SKIP: jq not installed"
+        exit 0
+fi
+
+if [[ ! -v NUM_NETIFS ]]; then
+        echo "SKIP: importer does not define \"NUM_NETIFS\""
+        exit 0
+fi
+
+##############################################################################
+# Network interfaces configuration
+
+for i in $(eval echo {1..$NUM_NETIFS}); do
+        ip link show dev ${NETIFS[p$i]} &> /dev/null
+        if [[ $? -ne 0 ]]; then
+                echo "SKIP: could not find all required interfaces"
+                exit 0
+        fi
+done
+
+##############################################################################
+# Helpers
+
+# Exit status to return at the end. Set in case one of the tests fails.
+EXIT_STATUS=0
+# Per-test return value. Clear at the beginning of each test.
+RET=0
+
+check_err()
+{
+        local err=$1
+        local msg=$2
+
+        if [[ $RET -eq 0 && $err -ne 0 ]]; then
+                RET=$err
+                retmsg=$msg
+        fi
+}
+
+check_fail()
+{
+        local err=$1
+        local msg=$2
+
+        if [[ $RET -eq 0 && $err -eq 0 ]]; then
+                RET=1
+                retmsg=$msg
+        fi
+}
+
+log_test()
+{
+        local test_name=$1
+        local opt_str=$2
+
+        if [[ $# -eq 2 ]]; then
+                opt_str="($opt_str)"
+        fi
+
+        if [[ $RET -ne 0 ]]; then
+                EXIT_STATUS=1
+                printf "TEST: %-60s  [FAIL]\n" "$test_name $opt_str"
+                if [[ ! -z "$retmsg" ]]; then
+                        printf "\t%s\n" "$retmsg"
+                fi
+                if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
+                        echo "Hit enter to continue, 'q' to quit"
+                        read a
+                        [ "$a" = "q" ] && exit 1
+                fi
+                return 1
+        fi
+
+        printf "TEST: %-60s  [PASS]\n" "$test_name $opt_str"
+        return 0
+}
+
+setup_wait()
+{
+        for i in $(eval echo {1..$NUM_NETIFS}); do
+                while true; do
+                        ip link show dev ${NETIFS[p$i]} up \
+                                | grep 'state UP' &> /dev/null
+                        if [[ $? -ne 0 ]]; then
+                                sleep 1
+                        else
+                                break
+                        fi
+                done
+        done
+
+        # Make sure links are ready.
+        sleep $WAIT_TIME
+}
+
+pre_cleanup()
+{
+        if [ "${PAUSE_ON_CLEANUP}" = "yes" ]; then
+                echo "Pausing before cleanup, hit any key to continue"
+                read
+        fi
+}
+
+vrf_prepare()
+{
+        ip -4 rule add pref 32765 table local
+        ip -4 rule del pref 0
+        ip -6 rule add pref 32765 table local
+        ip -6 rule del pref 0
+}
+
+vrf_cleanup()
+{
+        ip -6 rule add pref 0 table local
+        ip -6 rule del pref 32765
+        ip -4 rule add pref 0 table local
+        ip -4 rule del pref 32765
+}
+
+__last_tb_id=0
+declare -A __TB_IDS
+
+__vrf_td_id_assign()
+{
+        local vrf_name=$1
+
+        __last_tb_id=$((__last_tb_id + 1))
+        __TB_IDS[$vrf_name]=$__last_tb_id
+        return $__last_tb_id
+}
+
+__vrf_td_id_lookup()
+{
+        local vrf_name=$1
+
+        return ${__TB_IDS[$vrf_name]}
+}
+
+vrf_create()
+{
+        local vrf_name=$1
+        local tb_id
+
+        __vrf_td_id_assign $vrf_name
+        tb_id=$?
+
+        ip link add dev $vrf_name type vrf table $tb_id
+        ip -4 route add table $tb_id unreachable default metric 4278198272
+        ip -6 route add table $tb_id unreachable default metric 4278198272
+}
+
+vrf_destroy()
+{
+        local vrf_name=$1
+        local tb_id
+
+        __vrf_td_id_lookup $vrf_name
+        tb_id=$?
+
+        ip -6 route del table $tb_id unreachable default metric 4278198272
+        ip -4 route del table $tb_id unreachable default metric 4278198272
+        ip link del dev $vrf_name
+}
+
+__addr_add_del()
+{
+        local if_name=$1
+        local add_del=$2
+        local array
+
+        shift
+        shift
+        array=("${@}")
+
+        for addrstr in "${array[@]}"; do
+                ip address $add_del $addrstr dev $if_name
+        done
+}
+
+simple_if_init()
+{
+        local if_name=$1
+        local vrf_name
+        local array
+
+        shift
+        vrf_name=v$if_name
+        array=("${@}")
+
+        vrf_create $vrf_name
+        ip link set dev $if_name master $vrf_name
+        ip link set dev $vrf_name up
+        ip link set dev $if_name up
+
+        __addr_add_del $if_name add "${array[@]}"
+}
+
+simple_if_fini()
+{
+        local if_name=$1
+        local vrf_name
+        local array
+
+        shift
+        vrf_name=v$if_name
+        array=("${@}")
+
+        __addr_add_del $if_name del "${array[@]}"
+
+        ip link set dev $if_name down
+        vrf_destroy $vrf_name
+}
+
+master_name_get()
+{
+        local if_name=$1
+
+        ip -j link show dev $if_name | jq -r '.[]["master"]'
+}
+
+##############################################################################
+# Tests
+
+ping_test()
+{
+        local if_name=$1
+        local dip=$2
+        local vrf_name
+
+        RET=0
+
+        vrf_name=$(master_name_get $if_name)
+        ip vrf exec $vrf_name $PING $dip -c 10 -i 0.1 -w 2 &> /dev/null
+        check_err $?
+        log_test "ping"
+}
+
+ping6_test()
+{
+        local if_name=$1
+        local dip=$2
+        local vrf_name
+
+        RET=0
+
+        vrf_name=$(master_name_get $if_name)
+        ip vrf exec $vrf_name $PING6 $dip -c 10 -i 0.1 -w 2 &> /dev/null
+        check_err $?
+        log_test "ping6"
+}