[PATCH net-next v5 7/7] bonding: Selftest and documentation for the arp_ip_target parameter.

[David Wilder <wilder@us.ibm.com>]

This selftest provided a functional test for the arp_ip_target parameter
both with and without user supplied vlan tags.

and

Updates to the bonding documentation.

Signed-off-by: David Wilder <wilder@us.ibm.com>
---
 Documentation/networking/bonding.rst          |  11 ++
 .../selftests/drivers/net/bonding/Makefile    |   3 +-
 .../drivers/net/bonding/bond-arp-ip-target.sh | 179 ++++++++++++++++++
 3 files changed, 192 insertions(+), 1 deletion(-)
 create mode 100755 tools/testing/selftests/drivers/net/bonding/bond-arp-ip-target.sh

diff --git a/Documentation/networking/bonding.rst b/Documentation/networking/bonding.rst
index f8f5766703d4..4a80da56b784 100644
--- a/Documentation/networking/bonding.rst
+++ b/Documentation/networking/bonding.rst
@@ -313,6 +313,17 @@ arp_ip_target
 	maximum number of targets that can be specified is 16.  The
 	default value is no IP addresses.
 
+        When an arp_ip_target is configured the bonding driver will
+        attempt to automatically determine what vlans the arp probe will
+        pass through. This process of gathering vlan tags is required
+        for the arp probe to be sent. However, in some configurations
+        this process may fail. In these cases you may manually
+        supply a list of vlan tags. To specify a list of vlan tags
+        append the ipv4 address with [tag1/tag2...]. For example:
+        arp_ip_target=10.0.0.1[10]. If you simply need to disable the
+        vlan discovery process you may provide an empty list, for example:
+        arp_ip_target=10.0.0.1[].
+
 ns_ip6_target
 
 	Specifies the IPv6 addresses to use as IPv6 monitoring peers when
diff --git a/tools/testing/selftests/drivers/net/bonding/Makefile b/tools/testing/selftests/drivers/net/bonding/Makefile
index 2b10854e4b1e..c59bb2912a38 100644
--- a/tools/testing/selftests/drivers/net/bonding/Makefile
+++ b/tools/testing/selftests/drivers/net/bonding/Makefile
@@ -10,7 +10,8 @@ TEST_PROGS := \
 	mode-2-recovery-updelay.sh \
 	bond_options.sh \
 	bond-eth-type-change.sh \
-	bond_macvlan_ipvlan.sh
+	bond_macvlan_ipvlan.sh \
+	bond-arp-ip-target.sh
 
 TEST_FILES := \
 	lag_lib.sh \
diff --git a/tools/testing/selftests/drivers/net/bonding/bond-arp-ip-target.sh b/tools/testing/selftests/drivers/net/bonding/bond-arp-ip-target.sh
new file mode 100755
index 000000000000..e9af27f17d0f
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/bonding/bond-arp-ip-target.sh
@@ -0,0 +1,179 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Test bonding arp_ip_target.
+# Topology for Bond mode 1,5,6 testing
+#
+#  +-------------------------+
+#  |                         | Server
+#  |       bond.10.20.30     | 192.30.2.1/24
+#  |            |            |
+#  |        bond0.10.20      | 192.20.2.1/24
+#  |            |            |
+#  |         bond0.10        | 192.10.2.1/24
+#  |            |            |
+#  |          bond0          | 192.0.2.1/24
+#  |            |            |
+#  |            +            |
+#  |      eth0  |  eth1      |
+#  |        +---+---+        |
+#  |        |       |        |
+#  +-------------------------+
+#           |       |
+#  +-------------------------+
+#  |        |       |        |
+#  |    +---+-------+---+    |  Gateway
+#  |    |      br0      |    |
+#  |    +-------+-------+    |
+#  |            |            |
+#  +-------------------------+
+#               |
+#  +-------------------------+
+#  |            |            |  Client
+#  |          eth0           | 192.0.0.2/24
+#  |            |            |
+#  |         eth0.10         | 192.10.10.2/24
+#  |            |            |
+#  |        eth0.10.20       | 192.20.20.2/24
+#  |            |            |
+#  |      eth0.10.20.30      | 192.30.30.2/24
+#  +-------------------------+
+
+lib_dir=$(dirname "$0")
+
+# shellcheck source=./bond_topo_2d1c.sh
+source "${lib_dir}"/bond_topo_2d1c.sh
+
+DEBUG=${DEBUG:-0}
+test "${DEBUG}" -ne 0 && set -x
+
+# vlan subnets
+c_ip4="192.0.2.10"
+c_ip4v10="192.10.2.10"
+c_ip4v20="192.20.2.10"
+
+ALL_TESTS="
+    no_vlan_hints
+    with_vlan_hints
+"
+
+# Build stacked vlans on top of an interface.
+stack_vlans()
+{
+    RET=0
+    local interface="$1"
+    local ns=$2
+    local last="$interface"
+    local tags="10 20"
+
+    if ! ip -n "${ns}" link show "${interface}" > /dev/null; then
+        RET=1
+        msg="Failed to create ${interface}"
+        return
+    fi
+
+    if [ "$ns" == "${s_ns}" ]; then host=1; else host=10;fi
+
+    for tag in $tags; do
+        ip -n "${ns}" link add link "$last" name "$last"."$tag" type vlan id "$tag"
+        ip -n "${ns}" address add 192."$tag".2."$host"/24 dev "$last"."$tag"
+        ip -n "${ns}" link set up dev "$last"."$tag"
+        last=$last.$tag
+    done
+}
+
+# Check for link flapping
+check_failure_count()
+{
+    RET=0
+    local ns=$1
+    local proc_file=/proc/net/bonding/$2
+    local  counts
+
+    # Give the bond time to settle.
+    sleep 10
+
+    counts=$(ip netns exec "${ns}" grep -F "Link Failure Count" "${proc_file}" \
+	    | awk -F: '{print $2}')
+
+    local i
+    for i in $counts; do
+        [ "$i" != 0 ] && RET=1
+    done
+}
+
+setup_bond_topo()
+{
+    setup_prepare
+    setup_wait
+    stack_vlans bond0 "${s_ns}"
+    stack_vlans eth0 "${c_ns}"
+}
+
+skip_with_vlan_hints()
+{
+    # check if iproute supports arp_ip_target with vlans option.
+    if ! ip -n "${s_ns}" link add bond2 type bond arp_ip_target 10.0.0.1[10]; then
+        ip -n "${s_ns}" link del bond2 2> /dev/null
+        return 0
+    fi
+    return 1
+}
+
+no_vlan_hints()
+{
+        RET=0
+        local targets="${c_ip4} ${c_ip4v10} ${c_ip4v20}"
+        local target
+        msg=""
+
+        for target in $targets; do
+                bond_reset "mode $mode arp_interval 100 arp_ip_target ${target}"
+
+                stack_vlans bond0 "${s_ns}"
+                if [ $RET -ne 0 ]; then
+                    log_test "no_vlan_hints" "${msg}"
+                    return
+                fi
+
+                check_failure_count "${s_ns}" bond0
+                log_test "arp_ip_target=${target} ${msg}"
+        done
+}
+
+with_vlan_hints()
+{
+        RET=0
+        local targets="${c_ip4}[] ${c_ip4v10}[10] ${c_ip4v20}[10/20]"
+        local target
+        msg=""
+
+        if skip_with_vlan_hints; then
+            log_test_skip "skip_with_vlan_hints" \
+	          "Installed iproute doesn't support extended arp_ip_target options."
+            return 0
+        fi
+
+        for target in $targets; do
+                bond_reset "mode $mode arp_interval 100 arp_ip_target ${target}"
+
+                stack_vlans bond0 "${s_ns}"
+                if [ $RET -ne 0 ]; then
+                    log_test "no_vlan_hints" "${msg}"
+                    return
+                fi
+
+                check_failure_count "${s_ns}" bond0
+                log_test "arp_ip_target=${target} ${msg}"
+        done
+}
+
+
+trap cleanup EXIT
+
+mode=active-backup
+
+setup_bond_topo
+tests_run
+
+exit "$EXIT_STATUS"
-- 
2.43.5