[PATCH mptcp-next v4 0/2] selftests: mptcp: convert iptables to nftables

[PATCH mptcp-next v4 0/2] selftests: mptcp: convert iptables to nftables

[Hangbin Liu]

iptables has been deprecated for years. The Linux kernel has included
nftables as the successor to iptables since 2014, and every major
distribution uses nftables as the default packet filtering framework.
The iptables command we run on modern systems is actually iptables‑nft,
a compatibility layer that translates iptables syntax to nftables rules
behind the scenes.

There are also some features that can be set easily with nft, while we need
to convert to BPF code under iptables, such as MPTCP add‑addr and
remove‑addr suboptions. To make future work easier, convert iptables usage
in mptcp to nftables.

For mptcp_join.sh, I add an init_nftables() function so we can only init
nftables when needed. With debug kernel on my 4 cpu vm, Here is the
total running time of mptcp_join.sh.

With iptables

real    35m44.460s
user    0m22.455s
sys     25m17.923s

With nft init on each init_partial (Patch v2 version)
real    43m37.393s
user    0m29.183s
sys     32m15.354s

With nft init only called needed (Patch v3 version)
real    37m6.645s
user    0m25.325s
sys     27m10.385s

We only increase 1m22s compared with iptables.

Signed-off-by: Hangbin Liu <liuhangbin@kylinos.cn>
---
Changes in v4:
- fix add table typo in init_nftables() (sashiko)
- Flush the nft table(which is safe) instead of using global nft_handle (Matthieu Baerts)
- Link to v3: https://lore.kernel.org/r/20260904-mptcp_nft-v3-0-4abedaf00bf9@kylinos.cn

Changes in v3:
- Use jq to get the nft handle and drop count (Matthieu Baerts)
- Remove iptables/ip6tables and CONFIG_NFT_COMPAT since no one use it
  after the conversion. (Matthieu Baerts)
- Add init_nftables() so we can only init the nf tables when needed (Matthieu Baerts)
- Bundle the nft init steps so we only need to call the nft binary once (Florian Westphal)
- Only get the nft_handle when needed and reset it before using (Matthieu Baerts)
- Link to v2: https://lore.kernel.org/r/20260903-mptcp_nft-v2-0-66283e4b9c3b@kylinos.cn

Changes in v2:
- Fix --sync and --tcp-flags RST convert not match issue (sashiko)
- make sure drop is a number in check_mark. (sashiko)
- Other than using one inet table, use ip/ip6 tables to retain the same
  table and chain names used by the original iptables/ip6tables setup.
- Link to v1: https://lore.kernel.org/r/20260902-mptcp_nft-v1-0-559caa16f410@kylinos.cn

---
Hangbin Liu (2):
      selftests: mptcp: convert iptables to nftables for mptcp_sockopt.sh
      selftests: mptcp: convert iptables to nftables for mptcp_join.sh

 tools/testing/selftests/net/mptcp/config           |   4 +-
 tools/testing/selftests/net/mptcp/mptcp_join.sh    | 149 ++++++++-------------
 tools/testing/selftests/net/mptcp/mptcp_lib.sh     |   2 +-
 tools/testing/selftests/net/mptcp/mptcp_sockopt.sh |  64 +++++----
 4 files changed, 98 insertions(+), 121 deletions(-)
---
base-commit: a5ccf9a640b87f84558f35b17b02747380128513
change-id: 20260902-mptcp_nft-b892782ef929

Best regards,
-- 
Hangbin Liu <liuhangbin@kylinos.cn>

[PATCH mptcp-next v4 1/2] selftests: mptcp: convert iptables to nftables for mptcp_sockopt.sh

[Hangbin Liu]

From: Hangbin Liu <liuhangbin@kylinos.cn>

During the conversion, we retain the same filter and chain names previously
used by iptables/ip6tables. Counters are not added to accept rules because
the test does not inspect them. After conversion, the generated output
matches the original iptables/ip6tables behavior.

Signed-off-by: Hangbin Liu <liuhangbin@kylinos.cn>
---
 tools/testing/selftests/net/mptcp/mptcp_lib.sh     |  2 +-
 tools/testing/selftests/net/mptcp/mptcp_sockopt.sh | 64 ++++++++++++----------
 2 files changed, 37 insertions(+), 29 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index b9d14647f401..e65b4ebee06a 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
@@ -528,7 +528,7 @@ mptcp_lib_check_tools() {
 				exit ${KSFT_SKIP}
 			fi
 			;;
-		"iptables"* | "ip6tables"*)
+		"iptables"* | "ip6tables"* | "nft" | "jq")
 			if ! "${tool}" -V &> /dev/null; then
 				mptcp_lib_pr_skip "Could not run all tests without ${tool}"
 				exit ${KSFT_SKIP}
diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
index e850a87429b6..b4e3eddc9cf2 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
@@ -15,8 +15,6 @@ cin=""
 cout=""
 timeout_poll=30
 timeout_test=$((timeout_poll * 2 + 1))
-iptables="iptables"
-ip6tables="ip6tables"
 
 ns1=""
 ns2=""
@@ -49,16 +47,27 @@ add_mark_rules()
 	local ns=$1
 	local m=$2
 
-	local t
-	for t in ${iptables} ${ip6tables}; do
-		# just to debug: check we have multiple subflows connection requests
-		ip netns exec $ns $t -A OUTPUT -p tcp --syn -m mark --mark $m -j ACCEPT
-
-		# RST packets might be handled by a internal dummy socket
-		ip netns exec $ns $t -A OUTPUT -p tcp --tcp-flags RST RST -m mark --mark 0 -j ACCEPT
-
-		ip netns exec $ns $t -A OUTPUT -p tcp -m mark --mark $m -j ACCEPT
-		ip netns exec $ns $t -A OUTPUT -p tcp -m mark --mark 0 -j DROP
+	local table
+	for table in ip ip6; do
+		ip netns exec "$ns" nft -f - <<-EOF
+			add table $table filter
+			add chain $table filter OUTPUT \
+				{ type filter hook output priority 0; policy accept; }
+
+			# just to debug: check we have multiple subflows connection requests
+			add rule $table filter OUTPUT \
+				tcp flags & (fin | syn | rst | ack) == syn \
+				meta mark $m accept
+
+			# RST packets might be handled by a internal dummy socket
+			add rule $table filter OUTPUT \
+				tcp flags & rst == rst meta mark 0x0 accept
+
+			add rule $table filter OUTPUT \
+				meta l4proto tcp meta mark $m accept
+			add rule $table filter OUTPUT \
+				meta l4proto tcp meta mark 0 counter drop
+		EOF
 	done
 }
 
@@ -105,32 +114,31 @@ cleanup()
 
 mptcp_lib_check_mptcp
 mptcp_lib_check_kallsyms
-mptcp_lib_check_tools ip "${iptables}" "${ip6tables}"
+mptcp_lib_check_tools ip nft jq
 
 check_mark()
 {
 	local ns=$1
 	local af=$2
 
-	local tables=${iptables}
+	local tables="ip"
 
 	if [ $af -eq 6 ];then
-		tables=${ip6tables}
+		tables="ip6"
 	fi
 
-	local counters values
-	counters=$(ip netns exec $ns $tables -v -L OUTPUT | grep DROP)
-	values=${counters%DROP*}
-
-	local v
-	for v in $values; do
-		if [ $v -ne 0 ]; then
-			mptcp_lib_pr_fail "got $tables $values in ns $ns," \
-					  "not 0 - not all expected packets marked"
-			ret=${KSFT_FAIL}
-			return 1
-		fi
-	done
+	local drops
+	drops=$(ip netns exec "$ns" nft -j list table "$tables" filter | \
+		jq '.nftables[] | select(has("rule")) | .rule |
+			select (.chain=="OUTPUT" and any(.expr[]; has("drop"))) |
+			.expr[] | select(has("counter")) | .counter.packets')
+
+	if [ -z "$drops" ] || [ "$drops" -ne 0 ]; then
+		mptcp_lib_pr_fail "got $tables $drops in ns $ns," \
+				  "not 0 - not all expected packets marked"
+		ret=${KSFT_FAIL}
+		return 1
+	fi
 
 	return 0
 }

-- 
2.55.0

[PATCH mptcp-next v4 2/2] selftests: mptcp: convert iptables to nftables for mptcp_join.sh

[Hangbin Liu]

From: Hangbin Liu <liuhangbin@kylinos.cn>

During conversion, we retain the same table and chain names used by the
original iptables/ip6tables setup, so rule output is identical to the
former iptables/ip6tables output. Add new function init_nftables so we
only do nft table setup when test need set nft rules.

Unlike iptables, nftables cannot match rules based on their full
specification. Since endpoint_tests is the only test that delete rules,
which inserts and deletes rules one by one. Flushing the table
directly is safe and easier than using nft_handle.

The BPF bytecode matching MPTCP add‑addr and remove‑addr suboptions
is replaced with native nft matching using "tcp option mptcp subtype".

The config file adds CONFIG_NFT_NUMGEN (replaces iptables statistic nth),
CONFIG_NFT_REJECT and CONFIG_NFT_REJECT_INET for reject‑related rules.
Remove CONFIG_NFT_COMPAT since we don't need it now.

Remove the iptables/ip6tables check in mptcp_lib.sh since no script use
it now.

Signed-off-by: Hangbin Liu <liuhangbin@kylinos.cn>
---
 tools/testing/selftests/net/mptcp/config        |   4 +-
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 149 +++++++++---------------
 tools/testing/selftests/net/mptcp/mptcp_lib.sh  |   2 +-
 3 files changed, 62 insertions(+), 93 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/config b/tools/testing/selftests/net/mptcp/config
index 59051ee2a986..25dd134b9907 100644
--- a/tools/testing/selftests/net/mptcp/config
+++ b/tools/testing/selftests/net/mptcp/config
@@ -29,7 +29,9 @@ CONFIG_NET_SCH_INGRESS=m
 CONFIG_NET_SCH_NETEM=m
 CONFIG_NF_TABLES=m
 CONFIG_NF_TABLES_INET=y
-CONFIG_NFT_COMPAT=m
+CONFIG_NFT_NUMGEN=m
+CONFIG_NFT_REJECT=m
+CONFIG_NFT_REJECT_INET=m
 CONFIG_NFT_SOCKET=m
 CONFIG_NFT_TPROXY=m
 CONFIG_SYN_COOKIES=y
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 18ce7136a2b0..d267a678383b 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -26,8 +26,6 @@ capout=""
 cappid=""
 ns1=""
 ns2=""
-iptables="iptables"
-ip6tables="ip6tables"
 timeout_poll=30
 timeout_test=$((timeout_poll * 2 + 1))
 capture=false
@@ -99,42 +97,6 @@ unset add_addr_tx_nr
 unset add_addr_echo_tx_nr
 unset add_addr_drop_tx_nr
 
-# generated using "nfbpf_compile '(ip && (ip[54] & 0xf0) == 0x30) ||
-#				  (ip6 && (ip6[74] & 0xf0) == 0x30)'"
-CBPF_MPTCP_SUBOPTION_ADD_ADDR="14,
-			       48 0 0 0,
-			       84 0 0 240,
-			       21 0 3 64,
-			       48 0 0 54,
-			       84 0 0 240,
-			       21 6 7 48,
-			       48 0 0 0,
-			       84 0 0 240,
-			       21 0 4 96,
-			       48 0 0 74,
-			       84 0 0 240,
-			       21 0 1 48,
-			       6 0 0 65535,
-			       6 0 0 0"
-
-# IPv4: TCP hdr of 48B, a first suboption of 12B (DACK8), the RM_ADDR suboption
-# generated using "nfbpf_compile '(ip[32] & 0xf0) == 0xc0 && ip[53] == 0x0c &&
-#				  (ip[66] & 0xf0) == 0x40'"
-CBPF_MPTCP_SUBOPTION_RM_ADDR="13,
-			      48 0 0 0,
-			      84 0 0 240,
-			      21 0 9 64,
-			      48 0 0 32,
-			      84 0 0 240,
-			      21 0 6 192,
-			      48 0 0 53,
-			      21 0 4 12,
-			      48 0 0 66,
-			      84 0 0 240,
-			      21 0 1 64,
-			      6 0 0 65535,
-			      6 0 0 0"
-
 init_partial()
 {
 	capout=$(mktemp)
@@ -184,6 +146,26 @@ init_shapers()
 	done
 }
 
+init_nftables()
+{
+	local netns table
+	for netns in "$ns1" "$ns2"; do
+		for table in ip ip6; do
+			ip netns exec "$netns" nft -f - <<-EOF
+				add table $table filter
+				add chain $table filter INPUT \
+					{ type filter hook input priority filter; policy accept; }
+				add chain $table filter OUTPUT \
+					{ type filter hook output priority filter; policy accept; }
+
+				add table $table mangle
+				add chain $table mangle OUTPUT \
+					{ type route hook output priority mangle; policy accept; }
+			EOF
+		done
+	done
+}
+
 cleanup_partial()
 {
 	rm -f "$capout"
@@ -196,7 +178,7 @@ init() {
 
 	mptcp_lib_check_mptcp
 	mptcp_lib_check_kallsyms
-	mptcp_lib_check_tools ip tc ss "${iptables}" "${ip6tables}"
+	mptcp_lib_check_tools ip tc ss nft
 
 	sin=$(mktemp)
 	sout=$(mktemp)
@@ -380,24 +362,18 @@ reset_with_cookies()
 # $1: test name
 reset_with_add_addr_timeout()
 {
-	local ip="${2:-4}"
-	local tables
+	local ip="${2:-}"
 
 	reset "${1}" || return 1
-
-	tables="${iptables}"
-	if [ $ip -eq 6 ]; then
-		tables="${ip6tables}"
-	fi
+	init_nftables
 
 	# set a maximum, to avoid too long timeout with exponential backoff
 	ip netns exec $ns1 sysctl -q net.mptcp.add_addr_timeout=1
 
-	if ! ip netns exec $ns2 $tables -A OUTPUT -p tcp \
-			-m tcp --tcp-option 30 \
-			-m bpf --bytecode \
-			"$CBPF_MPTCP_SUBOPTION_ADD_ADDR" \
-			-j DROP; then
+	if ! ip netns exec "$ns2" nft add rule \
+		ip"$ip" filter OUTPUT meta l4proto tcp \
+		tcp option mptcp subtype add-addr \
+		drop; then
 		mark_as_skipped "unable to set the 'add addr' rule"
 		return 1
 	fi
@@ -449,22 +425,14 @@ setup_fail_rules()
 	check_invert=1
 	validate_checksum=true
 	local i="$1"
-	local ip="${2:-4}"
-	local tables
+	local ip="${2:-}"
 
-	tables="${iptables}"
-	if [ $ip -eq 6 ]; then
-		tables="${ip6tables}"
-	fi
-
-	ip netns exec $ns2 $tables \
-		-t mangle \
-		-A OUTPUT \
-		-o ns2eth$i \
-		-p tcp \
-		-m length --length 150:9999 \
-		-m statistic --mode nth --packet 1 --every 99999 \
-		-j MARK --set-mark 42 || return ${KSFT_SKIP}
+	init_nftables
+	ip netns exec "$ns2" nft add rule \
+		ip"$ip" mangle OUTPUT oifname ns2eth$i \
+		meta l4proto tcp \
+		meta length 150-9999 numgen inc mod 99999 1 \
+		meta mark set 42 || return ${KSFT_SKIP}
 
 	tc -n $ns2 qdisc add dev ns2eth$i clsact || return ${KSFT_SKIP}
 	tc -n $ns2 filter add dev ns2eth$i egress \
@@ -510,16 +478,15 @@ reset_with_tcp_filter()
 	reset "${1}" || return 1
 	shift
 
+	init_nftables
+
 	local ns="${!1}"
 	local src="${2}"
 	local target="${3}"
 	local chain="${4:-INPUT}"
 
-	if ! ip netns exec "${ns}" ${iptables} \
-			-A "${chain}" \
-			-s "${src}" \
-			-p tcp \
-			-j "${target}"; then
+	if ! ip netns exec "$ns" nft add rule ip filter "${chain}" \
+		ip saddr "${src}" meta l4proto tcp "${target,,}"; then
 		mark_as_skipped "unable to set the filter rules"
 		return 1
 	fi
@@ -4313,12 +4280,15 @@ userspace_tests()
 		chk_mptcp_info subflows 1 subflows 1
 		chk_subflows_total 2 2
 
+		init_nftables
 		# force quick loss
 		ip netns exec $ns2 sysctl -q net.ipv4.tcp_syn_retries=1
-		if ip netns exec "${ns1}" ${iptables} -A INPUT -s "10.0.1.2" \
-		      -p tcp --tcp-option 30 -j REJECT --reject-with tcp-reset &&
-		   ip netns exec "${ns2}" ${iptables} -A INPUT -d "10.0.1.2" \
-		      -p tcp --tcp-option 30 -j REJECT --reject-with tcp-reset; then
+		if ip netns exec "${ns1}" nft add rule ip filter INPUT \
+			ip saddr "10.0.1.2" meta l4proto tcp \
+			tcp option mptcp exists reject with tcp reset &&
+		   ip netns exec "${ns2}" nft add rule ip filter INPUT \
+			ip daddr "10.0.1.2" meta l4proto tcp \
+			tcp option mptcp exists reject with tcp reset; then
 			wait_event ns2 MPTCP_LIB_EVENT_SUB_CLOSED 1
 			wait_event ns1 MPTCP_LIB_EVENT_SUB_CLOSED 1
 			chk_subflows_total 1 1
@@ -4393,7 +4363,7 @@ endpoint_tests()
 		chk_subflow_nr "after new reject" 2
 		chk_mptcp_info subflows 1 subflows 1
 
-		ip netns exec "${ns2}" ${iptables} -D OUTPUT -s "10.0.3.2" -p tcp -j REJECT
+		ip netns exec "${ns2}" nft flush chain ip filter OUTPUT
 		pm_nl_del_endpoint $ns2 3 10.0.3.2
 		pm_nl_add_endpoint $ns2 10.0.3.2 id 3 flags subflow
 		wait_mpj 3
@@ -4402,12 +4372,10 @@ endpoint_tests()
 
 		# To make sure RM_ADDR are sent over a different subflow, but
 		# allow the rest to quickly and cleanly close the subflow
-		local ipt=1
-		ip netns exec "${ns2}" ${iptables} -I OUTPUT -s "10.0.1.2" \
-			-p tcp -m tcp --tcp-option 30 \
-			-m bpf --bytecode \
-			"$CBPF_MPTCP_SUBOPTION_RM_ADDR" \
-			-j DROP || ipt=0
+		local nft=1
+		ip netns exec "${ns2}" nft insert rule ip filter OUTPUT \
+			ip saddr 10.0.1.2 meta l4proto tcp \
+			tcp option mptcp subtype remove-addr drop || nft=0
 		local i
 		for i in $(seq 3); do
 			pm_nl_del_endpoint $ns2 1 10.0.1.2
@@ -4420,7 +4388,7 @@ endpoint_tests()
 			chk_subflow_nr "after re-add id 0 ($i)" 3
 			chk_mptcp_info subflows 3 subflows 3
 		done
-		[ ${ipt} = 1 ] && ip netns exec "${ns2}" ${iptables} -D OUTPUT 1
+		[ "${nft}" = 1 ] && ip netns exec "${ns2}" nft flush chain ip filter OUTPUT
 
 		mptcp_lib_kill_group_wait $tests_pid
 
@@ -4480,20 +4448,19 @@ endpoint_tests()
 		chk_mptcp_info subflows 2 subflows 2
 		chk_mptcp_info add_addr_signal 2 add_addr_accepted 2
 
+		init_nftables
 		# To make sure RM_ADDR are sent over a different subflow, but
 		# allow the rest to quickly and cleanly close the subflow
-		local ipt=1
-		ip netns exec "${ns1}" ${iptables} -I OUTPUT -s "10.0.1.1" \
-			-p tcp -m tcp --tcp-option 30 \
-			-m bpf --bytecode \
-			"$CBPF_MPTCP_SUBOPTION_RM_ADDR" \
-			-j DROP || ipt=0
+		local nft=1
+		ip netns exec "${ns1}" nft insert rule ip filter OUTPUT \
+			ip saddr 10.0.1.1 meta l4proto tcp \
+			tcp option mptcp subtype remove-addr drop || nft=0
 		pm_nl_del_endpoint $ns1 42 10.0.1.1
 		sleep 0.5
 		chk_subflow_nr "after delete ID 0" 2
 		chk_mptcp_info subflows 2 subflows 2
 		chk_mptcp_info add_addr_signal 2 add_addr_accepted 2
-		[ ${ipt} = 1 ] && ip netns exec "${ns1}" ${iptables} -D OUTPUT 1
+		[ "${nft}" = 1 ] && ip netns exec "${ns1}" nft flush chain ip filter OUTPUT
 
 		pm_nl_add_endpoint $ns1 10.0.1.1 id 42 flags signal
 		wait_mpj 4
@@ -4555,7 +4522,7 @@ endpoint_tests()
 		pm_nl_flush_endpoint $ns2
 		pm_nl_flush_endpoint $ns1
 		wait_rm_addr $ns2 0
-		ip netns exec "${ns2}" ${iptables} -D OUTPUT -s "10.0.3.2" -p tcp -j REJECT
+		ip netns exec "${ns2}" nft flush chain ip filter OUTPUT
 		pm_nl_add_endpoint $ns2 10.0.3.2 id 3 flags subflow
 		wait_mpj 1
 		pm_nl_add_endpoint $ns1 10.0.3.1 id 2 flags signal
diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index e65b4ebee06a..0559bb168203 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
@@ -528,7 +528,7 @@ mptcp_lib_check_tools() {
 				exit ${KSFT_SKIP}
 			fi
 			;;
-		"iptables"* | "ip6tables"* | "nft" | "jq")
+		"nft" | "jq")
 			if ! "${tool}" -V &> /dev/null; then
 				mptcp_lib_pr_skip "Could not run all tests without ${tool}"
 				exit ${KSFT_SKIP}

-- 
2.55.0

Re: [PATCH mptcp-next v4 0/2] selftests: mptcp: convert iptables to nftables

[MPTCP CI]

Hi Hangbin,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join): Unstable: 1 failed test(s): packetdrill_add_addr ⚠️ 
- KVM Validation: normal (only selftest_mptcp_join): Success! ✅
- KVM Validation: debug (except selftest_mptcp_join): Success! ✅
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Perf: 
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/34223550098

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/84d6fbfc051a
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1160437


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)

Re: [PATCH mptcp-next v4 0/2] selftests: mptcp: convert iptables to nftables

[Matthieu Baerts]

Hi Hangbin,

On 08/09/2026 13:36, Hangbin Liu wrote:
> iptables has been deprecated for years. The Linux kernel has included
> nftables as the successor to iptables since 2014, and every major
> distribution uses nftables as the default packet filtering framework.
> The iptables command we run on modern systems is actually iptables‑nft,
> a compatibility layer that translates iptables syntax to nftables rules
> behind the scenes.
> 
> There are also some features that can be set easily with nft, while we need
> to convert to BPF code under iptables, such as MPTCP add‑addr and
> remove‑addr suboptions. To make future work easier, convert iptables usage
> in mptcp to nftables.
Thank you for the new version. It looks good to me:

Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>

Now in our tree (I just fixed the indentation after 'if .* nft' lines
not to align the rest of the nft commands with the conditional code):

New patches for t/upstream:
- 23ac116ea2c4: selftests: mptcp: convert iptables to nftables for
mptcp_sockopt.sh
- 0ae33af3f73f: selftests: mptcp: convert iptables to nftables for
mptcp_join.sh
- Results: ca7966735328..2dc29b34b99a (export)

Tests are now in progress:

- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/b49aa4201a14e200297db9adcde3495e5a778517/checks

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.