selftests/bpf/test_xdp_veth: use temp netns for testing

Use temp netns instead of hard code name for testing in case the
netns already exists.
Signed-off-by: NHangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20220125081717.1260849-3-liuhangbin@gmail.comSigned-off-by: NAlexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/test_xdp_veth.sh

@@ -22,6 +22,9 @@ ksft_skip=4
 TESTNAME=xdp_veth
 BPF_FS=$(awk '$3 == "bpf" {print $2; exit}' /proc/mounts)
 BPF_DIR=$BPF_FS/test_$TESTNAME
+readonly NS1="ns1-$(mktemp -u XXXXXX)"
+readonly NS2="ns2-$(mktemp -u XXXXXX)"
+readonly NS3="ns3-$(mktemp -u XXXXXX)"
 
 _cleanup()
 {
@@ -29,9 +32,9 @@ _cleanup()
 	ip link del veth1 2> /dev/null
 	ip link del veth2 2> /dev/null
 	ip link del veth3 2> /dev/null
-	ip netns del ns1 2> /dev/null
-	ip netns del ns2 2> /dev/null
-	ip netns del ns3 2> /dev/null
+	ip netns del ${NS1} 2> /dev/null
+	ip netns del ${NS2} 2> /dev/null
+	ip netns del ${NS3} 2> /dev/null
 	rm -rf $BPF_DIR 2> /dev/null
 }
 
@@ -77,24 +80,24 @@ set -e
 
 trap cleanup_skip EXIT
 
-ip netns add ns1
-ip netns add ns2
-ip netns add ns3
+ip netns add ${NS1}
+ip netns add ${NS2}
+ip netns add ${NS3}
 
-ip link add veth1 index 111 type veth peer name veth11 netns ns1
-ip link add veth2 index 122 type veth peer name veth22 netns ns2
-ip link add veth3 index 133 type veth peer name veth33 netns ns3
+ip link add veth1 index 111 type veth peer name veth11 netns ${NS1}
+ip link add veth2 index 122 type veth peer name veth22 netns ${NS2}
+ip link add veth3 index 133 type veth peer name veth33 netns ${NS3}
 
 ip link set veth1 up
 ip link set veth2 up
 ip link set veth3 up
 
-ip -n ns1 addr add 10.1.1.11/24 dev veth11
-ip -n ns3 addr add 10.1.1.33/24 dev veth33
+ip -n ${NS1} addr add 10.1.1.11/24 dev veth11
+ip -n ${NS3} addr add 10.1.1.33/24 dev veth33
 
-ip -n ns1 link set dev veth11 up
-ip -n ns2 link set dev veth22 up
-ip -n ns3 link set dev veth33 up
+ip -n ${NS1} link set dev veth11 up
+ip -n ${NS2} link set dev veth22 up
+ip -n ${NS3} link set dev veth33 up
 
 mkdir $BPF_DIR
 bpftool prog loadall \
@@ -107,12 +110,12 @@ ip link set dev veth1 xdp pinned $BPF_DIR/progs/redirect_map_0
 ip link set dev veth2 xdp pinned $BPF_DIR/progs/redirect_map_1
 ip link set dev veth3 xdp pinned $BPF_DIR/progs/redirect_map_2
 
-ip -n ns1 link set dev veth11 xdp obj xdp_dummy.o sec xdp
-ip -n ns2 link set dev veth22 xdp obj xdp_tx.o sec xdp
-ip -n ns3 link set dev veth33 xdp obj xdp_dummy.o sec xdp
+ip -n ${NS1} link set dev veth11 xdp obj xdp_dummy.o sec xdp
+ip -n ${NS2} link set dev veth22 xdp obj xdp_tx.o sec xdp
+ip -n ${NS3} link set dev veth33 xdp obj xdp_dummy.o sec xdp
 
 trap cleanup EXIT
 
-ip netns exec ns1 ping -c 1 -W 1 10.1.1.33
+ip netns exec ${NS1} ping -c 1 -W 1 10.1.1.33
 
 exit 0