bpf: fix XDP vlan selftests test_xdp_vlan.sh

Change BPF selftest test_xdp_vlan.sh to (default) use generic XDP.

This selftest was created together with a fix for generic XDP, in commit
29724956 ("net: fix generic XDP to handle if eth header was
mangled"). And was suppose to catch if generic XDP was broken again.

The tests are using veth and assumed that veth driver didn't support
native driver XDP, thus it used the (ip link set) 'xdp' attach that fell
back to generic-XDP. But veth gained native-XDP support in 948d4f21
("veth: Add driver XDP"), which caused this test script to use
native-XDP.

Fixes: 948d4f21 ("veth: Add driver XDP")
Fixes: 97396ff0 ("selftests/bpf: add XDP selftests for modifying and popping VLAN headers")
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tools/testing/selftests/bpf/test_xdp_vlan.sh

 #!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Author: Jesper Dangaard Brouer <hawk@kernel.org>
 
 TESTNAME=xdp_vlan
 
+# Default XDP mode
+XDP_MODE=xdpgeneric
+
 usage() {
   echo "Testing XDP + TC eBPF VLAN manipulations: $TESTNAME"
   echo ""
@@ -9,9 +14,23 @@ usage() {
   echo "  -v | --verbose : Verbose"
   echo "  --flush        : Flush before starting (e.g. after --interactive)"
   echo "  --interactive  : Keep netns setup running after test-run"
+  echo "  --mode=XXX     : Choose XDP mode (xdp | xdpgeneric | xdpdrv)"
   echo ""
 }
 
+valid_xdp_mode()
+{
+	local mode=$1
+
+	case "$mode" in
+		xdpgeneric | xdpdrv | xdp)
+			return 0
+			;;
+		*)
+			return 1
+	esac
+}
+
 cleanup()
 {
 	local status=$?
@@ -37,7 +56,7 @@ cleanup()
 
 # Using external program "getopt" to get --long-options
 OPTIONS=$(getopt -o hvfi: \
-    --long verbose,flush,help,interactive,debug -- "$@")
+    --long verbose,flush,help,interactive,debug,mode: -- "$@")
 if (( $? != 0 )); then
     usage
     echo "selftests: $TESTNAME [FAILED] Error calling getopt, unknown option?"
@@ -60,6 +79,11 @@ while true; do
 		cleanup
 		shift
 		;;
+	    --mode )
+		shift
+		XDP_MODE=$1
+		shift
+		;;
 	    -- )
 		shift
 		break
@@ -81,8 +105,14 @@ if [ "$EUID" -ne 0 ]; then
 	exit 1
 fi
 
-ip link set dev lo xdp off 2>/dev/null > /dev/null
-if [ $? -ne 0 ];then
+valid_xdp_mode $XDP_MODE
+if [ $? -ne 0 ]; then
+	echo "selftests: $TESTNAME [FAILED] unknown XDP mode ($XDP_MODE)"
+	exit 1
+fi
+
+ip link set dev lo xdpgeneric off 2>/dev/null > /dev/null
+if [ $? -ne 0 ]; then
 	echo "selftests: $TESTNAME [SKIP] need ip xdp support"
 	exit 0
 fi
@@ -166,7 +196,7 @@ export FILE=test_xdp_vlan.o
 
 # First test: Remove VLAN by setting VLAN ID 0, using "xdp_vlan_change"
 export XDP_PROG=xdp_vlan_change
-ip netns exec ns1 ip link set $DEVNS1 xdp object $FILE section $XDP_PROG
+ip netns exec ns1 ip link set $DEVNS1 $XDP_MODE object $FILE section $XDP_PROG
 
 # In ns1: egress use TC to add back VLAN tag 4011
 #  (del cmd)
@@ -187,8 +217,8 @@ ip netns exec ns1 ping -W 2 -c 3 $IPADDR2
 # ETH_P_8021Q indication, and this cause overwriting of our changes.
 #
 export XDP_PROG=xdp_vlan_remove_outer2
-ip netns exec ns1 ip link set $DEVNS1 xdp off
-ip netns exec ns1 ip link set $DEVNS1 xdp object $FILE section $XDP_PROG
+ip netns exec ns1 ip link set $DEVNS1 $XDP_MODE off
+ip netns exec ns1 ip link set $DEVNS1 $XDP_MODE object $FILE section $XDP_PROG
 
 # Now the namespaces should still be able reach each-other, test with ping:
 ip netns exec ns2 ping -W 2 -c 3 $IPADDR1