selftests/bpf: Xsk selftests framework

This patch adds AF_XDP selftests framework under selftests/bpf.

Topology:
---------
     -----------           -----------
     |  xskX   | --------- |  xskY   |
     -----------     |     -----------
          |          |          |
     -----------     |     ----------
     |  vethX  | --------- |  vethY |
     -----------   peer    ----------
          |          |          |
     namespaceX      |     namespaceY

Prerequisites setup by script test_xsk.sh:

   Set up veth interfaces as per the topology shown ^^:
   * setup two veth interfaces and one namespace
   ** veth<xxxx> in root namespace
   ** veth<yyyy> in af_xdp<xxxx> namespace
   ** namespace af_xdp<xxxx>
   * create a spec file veth.spec that includes this run-time configuration
   *** xxxx and yyyy are randomly generated 4 digit numbers used to avoid
       conflict with any existing interface
   * tests the veth and xsk layers of the topology

Signed-off-by: Weqaar Janjua <weqaar.a.janjua@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Yonghong Song <yhs@fb.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/20201207215333.11586-2-weqaar.a.janjua@intel.com

1 files changed, 119 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/xsk_prereqs.sh b/tools/testing/selftests/bpf/xsk_prereqs.sh
new file mode 100755
index 000000000000..29762739c21b
--- /dev/null
+++ b/tools/testing/selftests/bpf/xsk_prereqs.sh
@@ -0,0 +1,119 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright(c) 2020 Intel Corporation.
+
+ksft_pass=0
+ksft_fail=1
+ksft_xfail=2
+ksft_xpass=3
+ksft_skip=4
+
+GREEN='\033[0;92m'
+YELLOW='\033[0;93m'
+RED='\033[0;31m'
+NC='\033[0m'
+STACK_LIM=131072
+SPECFILE=veth.spec
+
+validate_root_exec()
+{
+	msg="skip all tests:"
+	if [ $UID != 0 ]; then
+		echo $msg must be run as root >&2
+		test_exit $ksft_fail 2
+	else
+		return $ksft_pass
+	fi
+}
+
+validate_veth_support()
+{
+	msg="skip all tests:"
+	if [ $(ip link add $1 type veth 2>/dev/null; echo $?;) != 0 ]; then
+		echo $msg veth kernel support not available >&2
+		test_exit $ksft_skip 1
+	else
+		ip link del $1
+		return $ksft_pass
+	fi
+}
+
+validate_veth_spec_file()
+{
+	if [ ! -f ${SPECFILE} ]; then
+		test_exit $ksft_skip 1
+	fi
+}
+
+test_status()
+{
+	statusval=$1
+	if [ -n "${colorconsole+set}" ]; then
+		if [ $statusval -eq 2 ]; then
+			echo -e "${YELLOW}$2${NC}: [ ${RED}FAIL${NC} ]"
+		elif [ $statusval -eq 1 ]; then
+			echo -e "${YELLOW}$2${NC}: [ ${RED}SKIPPED${NC} ]"
+		elif [ $statusval -eq 0 ]; then
+			echo -e "${YELLOW}$2${NC}: [ ${GREEN}PASS${NC} ]"
+		fi
+	else
+		if [ $statusval -eq 2 ]; then
+			echo -e "$2: [ FAIL ]"
+		elif [ $statusval -eq 1 ]; then
+			echo -e "$2: [ SKIPPED ]"
+		elif [ $statusval -eq 0 ]; then
+			echo -e "$2: [ PASS ]"
+		fi
+	fi
+}
+
+test_exit()
+{
+	retval=$1
+	if [ $2 -ne 0 ]; then
+		test_status $2 $(basename $0)
+	fi
+	exit $retval
+}
+
+clear_configs()
+{
+	if [ $(ip netns show | grep $3 &>/dev/null; echo $?;) == 0 ]; then
+		[ $(ip netns exec $3 ip link show $2 &>/dev/null; echo $?;) == 0 ] &&
+			{ echo "removing link $1:$2"; ip netns exec $3 ip link del $2; }
+		echo "removing ns $3"
+		ip netns del $3
+	fi
+	#Once we delete a veth pair node, the entire veth pair is removed,
+	#this is just to be cautious just incase the NS does not exist then
+	#veth node inside NS won't get removed so we explicitly remove it
+	[ $(ip link show $1 &>/dev/null; echo $?;) == 0 ] &&
+		{ echo "removing link $1"; ip link del $1; }
+	if [ -f ${SPECFILE} ]; then
+		echo "removing spec file:" ${SPECFILE}
+		rm -f ${SPECFILE}
+	fi
+}
+
+cleanup_exit()
+{
+	echo "cleaning up..."
+	clear_configs $1 $2 $3
+}
+
+validate_ip_utility()
+{
+	[ ! $(type -P ip) ] && { echo "'ip' not found. Skipping tests."; test_exit $ksft_skip 1; }
+}
+
+vethXDPgeneric()
+{
+	ip link set dev $1 xdpdrv off
+	ip netns exec $3 ip link set dev $2 xdpdrv off
+}
+
+vethXDPnative()
+{
+	ip link set dev $1 xdpgeneric off
+	ip netns exec $3 ip link set dev $2 xdpgeneric off
+}