selftests: mptcp: use setup_ns helper in lib.sh

This patch includes lib.sh into mptcp_lib.sh, uses setup_ns() helper
defined in lib.sh to set up namespaces in mptcp_lib_ns_init(). Then for
each namespace in NS_LIST, run all sysctl commands. This can drop some
duplicate code.

Signed-off-by: Geliang Tang <[email protected]>

tools/testing/selftests/net/mptcp/mptcp_lib.sh

@@ -1,6 +1,8 @@
 #! /bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
+. "$(dirname "${0}")/../lib.sh"
+
 readonly KSFT_PASS=0
 readonly KSFT_FAIL=1
 readonly KSFT_SKIP=4
@@ -412,20 +414,13 @@ mptcp_lib_check_tools() {
 }
 
 mptcp_lib_ns_init() {
-	local sec rndh
-
-	sec=$(date +%s)
-	rndh=$(printf %x "${sec}")-$(mktemp -u XXXXXX)
+	setup_ns "${@}"
 
 	local netns
-	for netns in "${@}"; do
-		eval "${netns}=${netns}-${rndh}"
-
-		ip netns add "${!netns}" || exit ${KSFT_SKIP}
-		ip -net "${!netns}" link set lo up
-		ip netns exec "${!netns}" sysctl -q net.mptcp.enabled=1
-		ip netns exec "${!netns}" sysctl -q net.ipv4.conf.all.rp_filter=0
-		ip netns exec "${!netns}" sysctl -q net.ipv4.conf.default.rp_filter=0
+	for netns in $NS_LIST; do
+		ip netns exec "${netns}" sysctl -q net.mptcp.enabled=1
+		ip netns exec "${netns}" sysctl -q net.ipv4.conf.all.rp_filter=0
+		ip netns exec "${netns}" sysctl -q net.ipv4.conf.default.rp_filter=0
 	done
 }