Merge branch 'mptcp-misc-features-for-v6-20-7-0'

Matthieu Baerts says:

====================
mptcp: misc. features for v6.20/7.0

This series contains a few independent new features, and small fixes for
net-next:

 - Patches 1-2: two small fixes linked to the MPTCP receive buffer that
   are not urgent, requiring code that has been recently changed, and is
   needed for the next patch. Because we are at the end of the cycle, it
   seems easier to send them to net-next, instead of dealing with
   conflicts between net and net-next.

 - Patch 3: a refactoring to simplify the code around MPTCP DRS.

 - Patch 4: a new trace event for MPTCP to help debugging receive buffer
   auto-tuning issues.

 - Patch 5: align internal MPTCP PM structure with NL specs, just to
   manipulate the same thing.

 - Patch 6: convert some min_t(int, ...) to min(): cleaner, and to avoid
   future warnings.

 - Patch 7: [removed]

 - Patch 8: sort all #include in MPTCP Diag tool in the selftests to
   prevent future potential conflicts and ease the reading.

 - Patches 9-11: improve the MPTCP Join selftest by waiting for an event
   instead of a "random" sleep.

 - Patches 12-14: some small cleanups in the selftests, seen while
   working on the previous patches.

 - Patch 15: avoid marking subtests as skipped while still validating
   most checks when executing the last MPTCP selftests on older kernels.
====================

Link: https://patch.msgid.link/20260203-net-next-mptcp-misc-feat-6-20-v1-0-31ec8bfc56d1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 73 insertions, 78 deletions

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c b/tools/testing/selftests/net/mptcp/mptcp_connect.c
index a74b13e42ecd..1e87757a6894 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c
@@ -259,7 +259,7 @@ static void set_transparent(int fd, int pf)
 	}
 }
 
-static void set_mptfo(int fd, int pf)
+static void set_mptfo(int fd)
 {
 	int qlen = 25;
 
@@ -336,7 +336,7 @@ static int sock_listen_mptcp(const char * const listenaddr,
 			set_transparent(sock, pf);
 
 		if (cfg_sockopt_types.mptfo)
-			set_mptfo(sock, pf);
+			set_mptfo(sock);
 
 		if (bind(sock, a->ai_addr, a->ai_addrlen) == 0)
 			break; /* success */
@@ -407,21 +407,18 @@ static int sock_connect_mptcp(const char * const remoteaddr,
 				*peer = a;
 				break; /* success */
 			}
+			perror("sendto()");
 		} else {
 			if (connect(sock, a->ai_addr, a->ai_addrlen) == 0) {
 				*peer = a;
 				break; /* success */
 			}
-		}
-		if (cfg_sockopt_types.mptfo) {
-			perror("sendto()");
-			close(sock);
-			sock = -1;
-		} else {
 			perror("connect()");
-			close(sock);
-			sock = -1;
 		}
+
+		/* error */
+		close(sock);
+		sock = -1;
 	}
 
 	freeaddrinfo(addr);
diff --git a/tools/testing/selftests/net/mptcp/mptcp_diag.c b/tools/testing/selftests/net/mptcp/mptcp_diag.c
index 8e0b1b8d84b6..5e222ba977e4 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_diag.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_diag.c
@@ -1,21 +1,24 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2025, Kylin Software */
 
-#include <linux/sock_diag.h>
-#include <linux/rtnetlink.h>
-#include <linux/inet_diag.h>
-#include <linux/netlink.h>
-#include <linux/compiler.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
 #include <sys/socket.h>
-#include <netinet/in.h>
-#include <linux/tcp.h>
+
 #include <arpa/inet.h>
 
-#include <unistd.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <stdio.h>
+#include <netinet/in.h>
+
+#include <linux/compiler.h>
+#include <linux/inet_diag.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <linux/sock_diag.h>
+#include <linux/tcp.h>
 
 #ifndef IPPROTO_MPTCP
 #define IPPROTO_MPTCP 262
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index e70d3420954f..dc1f200aaa81 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -603,8 +603,7 @@ wait_rm_addr()
 	local old_cnt="${2}"
 	local cnt
 
-	local i
-	for i in $(seq 10); do
+	for _ in $(seq 10); do
 		cnt=$(rm_addr_count ${ns})
 		[ "$cnt" = "${old_cnt}" ] || break
 		sleep 0.1
@@ -623,25 +622,22 @@ wait_rm_sf()
 	local old_cnt="${2}"
 	local cnt
 
-	local i
-	for i in $(seq 10); do
+	for _ in $(seq 10); do
 		cnt=$(rm_sf_count ${ns})
 		[ "$cnt" = "${old_cnt}" ] || break
 		sleep 0.1
 	done
 }
 
+# $1: expected MPJ ACK Rx counter in $ns1
 wait_mpj()
 {
-	local ns="${1}"
-	local cnt old_cnt
-
-	old_cnt=$(mptcp_lib_get_counter ${ns} "MPTcpExtMPJoinAckRx")
+	local exp_cnt="${1}"
+	local cnt
 
-	local i
-	for i in $(seq 10); do
-		cnt=$(mptcp_lib_get_counter ${ns} "MPTcpExtMPJoinAckRx")
-		[ "$cnt" = "${old_cnt}" ] || break
+	for _ in $(seq 10); do
+		cnt=$(mptcp_lib_get_counter ${ns1} "MPTcpExtMPJoinAckRx")
+		[ "${cnt}" = "${exp_cnt}" ] && break
 		sleep 0.1
 	done
 }
@@ -650,8 +646,7 @@ wait_ll_ready()
 {
 	local ns="${1}"
 
-	local i
-	for i in $(seq 50); do
+	for _ in $(seq 50); do
 		ip -n "${ns}" -6 addr show scope link | grep "inet6 fe80" |
 			grep -qw "tentative" || break
 		sleep 0.1
@@ -1407,7 +1402,7 @@ chk_join_tx_nr()
 
 	count=$(mptcp_lib_get_counter ${ns2} "MPTcpExtMPJoinSynTxCreatSkErr")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$create" ]; then
 		rc=${KSFT_FAIL}
 		print_check "syn tx create socket error"
@@ -1416,7 +1411,7 @@ chk_join_tx_nr()
 
 	count=$(mptcp_lib_get_counter ${ns2} "MPTcpExtMPJoinSynTxBindErr")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$bind" ]; then
 		rc=${KSFT_FAIL}
 		print_check "syn tx bind error"
@@ -1425,7 +1420,7 @@ chk_join_tx_nr()
 
 	count=$(mptcp_lib_get_counter ${ns2} "MPTcpExtMPJoinSynTxConnectErr")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$connect" ]; then
 		rc=${KSFT_FAIL}
 		print_check "syn tx connect error"
@@ -1451,7 +1446,7 @@ chk_fallback_nr()
 
 	count=$(mptcp_lib_get_counter ${!ns} "MPTcpExtInfiniteMapTx")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$infinite_map_tx" ]; then
 		rc=${KSFT_FAIL}
 		print_check "$ns infinite map tx fallback"
@@ -1460,7 +1455,7 @@ chk_fallback_nr()
 
 	count=$(mptcp_lib_get_counter ${!ns} "MPTcpExtDSSCorruptionFallback")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$dss_corruption" ]; then
 		rc=${KSFT_FAIL}
 		print_check "$ns dss corruption fallback"
@@ -1469,7 +1464,7 @@ chk_fallback_nr()
 
 	count=$(mptcp_lib_get_counter ${!ns} "MPTcpExtSimultConnectFallback")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$simult_conn" ]; then
 		rc=${KSFT_FAIL}
 		print_check "$ns simult conn fallback"
@@ -1478,7 +1473,7 @@ chk_fallback_nr()
 
 	count=$(mptcp_lib_get_counter ${!ns} "MPTcpExtMPCapableFallbackACK")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$mpc_passive" ]; then
 		rc=${KSFT_FAIL}
 		print_check "$ns mpc passive fallback"
@@ -1487,7 +1482,7 @@ chk_fallback_nr()
 
 	count=$(mptcp_lib_get_counter ${!ns} "MPTcpExtMPCapableFallbackSYNACK")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$mpc_active" ]; then
 		rc=${KSFT_FAIL}
 		print_check "$ns mpc active fallback"
@@ -1496,7 +1491,7 @@ chk_fallback_nr()
 
 	count=$(mptcp_lib_get_counter ${!ns} "MPTcpExtMPCapableDataFallback")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$mpc_data" ]; then
 		rc=${KSFT_FAIL}
 		print_check "$ns mpc data fallback"
@@ -1505,7 +1500,7 @@ chk_fallback_nr()
 
 	count=$(mptcp_lib_get_counter ${!ns} "MPTcpExtMD5SigFallback")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$md5_sig" ]; then
 		rc=${KSFT_FAIL}
 		print_check "$ns MD5 Sig fallback"
@@ -1514,7 +1509,7 @@ chk_fallback_nr()
 
 	count=$(mptcp_lib_get_counter ${!ns} "MPTcpExtDssFallback")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$dss" ]; then
 		rc=${KSFT_FAIL}
 		print_check "$ns dss fallback"
@@ -1590,7 +1585,7 @@ chk_join_nr()
 
 	count=$(mptcp_lib_get_counter ${ns2} "MPTcpExtMPJoinSynAckHMacFailure")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "0" ]; then
 		rc=${KSFT_FAIL}
 		print_check "synack HMAC"
@@ -1599,7 +1594,7 @@ chk_join_nr()
 
 	count=$(mptcp_lib_get_counter ${ns1} "MPTcpExtMPJoinAckRx")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$ack_nr" ]; then
 		rc=${KSFT_FAIL}
 		print_check "ack rx"
@@ -1608,7 +1603,7 @@ chk_join_nr()
 
 	count=$(mptcp_lib_get_counter ${ns1} "MPTcpExtMPJoinAckHMacFailure")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "0" ]; then
 		rc=${KSFT_FAIL}
 		print_check "ack HMAC"
@@ -1617,7 +1612,7 @@ chk_join_nr()
 
 	count=$(mptcp_lib_get_counter ${ns1} "MPTcpExtMPJoinRejected")
 	if [ -z "$count" ]; then
-		rc=${KSFT_SKIP}
+		: # ignore skip
 	elif [ "$count" != "$syn_rej" ]; then
 		rc=${KSFT_FAIL}
 		print_check "syn rejected"
@@ -1650,7 +1645,6 @@ chk_stale_nr()
 	local stale_min=$2
 	local stale_max=$3
 	local stale_delta=$4
-	local dump_stats
 	local stale_nr
 	local recover_nr
 
@@ -1666,16 +1660,11 @@ chk_stale_nr()
 		fail_test "got $stale_nr stale[s] $recover_nr recover[s], " \
 		     " expected stale in range [$stale_min..$stale_max]," \
 		     " stale-recover delta $stale_delta"
-		dump_stats=1
+		echo $ns stats
+		ip -n $ns -s link show
 	else
 		print_ok
 	fi
-
-	if [ "${dump_stats}" = 1 ]; then
-		echo $ns stats
-		ip netns exec $ns ip -s link show
-		ip netns exec $ns nstat -as | grep MPTcp
-	fi
 }
 
 chk_add_nr()
@@ -3718,7 +3707,6 @@ userspace_pm_add_addr()
 	tk=$(mptcp_lib_evts_get_info token "$evts")
 
 	ip netns exec $1 ./pm_nl_ctl ann $2 token $tk id $3
-	sleep 1
 }
 
 # $1: ns ; $2: id
@@ -3749,7 +3737,6 @@ userspace_pm_add_sf()
 
 	ip netns exec $1 ./pm_nl_ctl csf lip $2 lid $3 \
 				rip $da rport $dp token $tk
-	sleep 1
 }
 
 # $1: ns ; $2: addr $3: event type
@@ -3999,9 +3986,11 @@ userspace_tests()
 		{ timeout_test=120 test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
-		wait_mpj $ns1
+		wait_event ns1 MPTCP_LIB_EVENT_ESTABLISHED 1
 		userspace_pm_add_addr $ns1 10.0.2.1 10
+		wait_event ns2 MPTCP_LIB_EVENT_ANNOUNCED 1
 		userspace_pm_add_addr $ns1 10.0.3.1 20
+		wait_event ns2 MPTCP_LIB_EVENT_ANNOUNCED 2
 		chk_join_nr 2 2 2
 		chk_add_nr 2 2
 		chk_mptcp_info subflows 2 subflows 2
@@ -4032,8 +4021,9 @@ userspace_tests()
 		{ timeout_test=120 test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
-		wait_mpj $ns2
+		wait_event ns2 MPTCP_LIB_EVENT_ESTABLISHED 1
 		userspace_pm_add_sf $ns2 10.0.3.2 20
+		wait_event ns2 MPTCP_LIB_EVENT_SUB_ESTABLISHED 1
 		chk_join_nr 1 1 1
 		chk_mptcp_info subflows 1 subflows 1
 		chk_subflows_total 2 2
@@ -4060,10 +4050,11 @@ userspace_tests()
 		{ timeout_test=120 test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
-		wait_mpj $ns2
+		wait_event ns2 MPTCP_LIB_EVENT_ESTABLISHED 1
 		chk_mptcp_info subflows 0 subflows 0
 		chk_subflows_total 1 1
 		userspace_pm_add_sf $ns2 10.0.3.2 0
+		wait_event ns2 MPTCP_LIB_EVENT_SUB_ESTABLISHED 1
 		userspace_pm_chk_dump_addr "${ns2}" \
 			"id 0 flags subflow 10.0.3.2" "id 0 subflow"
 		chk_join_nr 1 1 1
@@ -4081,8 +4072,9 @@ userspace_tests()
 		{ timeout_test=120 test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
-		wait_mpj $ns2
+		wait_event ns2 MPTCP_LIB_EVENT_ESTABLISHED 1
 		userspace_pm_add_sf $ns2 10.0.3.2 20
+		wait_event ns2 MPTCP_LIB_EVENT_SUB_ESTABLISHED 1
 		chk_join_nr 1 1 1
 		chk_mptcp_info subflows 1 subflows 1
 		chk_subflows_total 2 2
@@ -4105,8 +4097,9 @@ userspace_tests()
 		{ timeout_test=120 test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
-		wait_mpj $ns1
+		wait_event ns1 MPTCP_LIB_EVENT_ESTABLISHED 1
 		userspace_pm_add_addr $ns1 10.0.2.1 10
+		wait_event ns2 MPTCP_LIB_EVENT_ANNOUNCED 1
 		chk_join_nr 1 1 1
 		chk_add_nr 1 1
 		chk_mptcp_info subflows 1 subflows 1
@@ -4133,6 +4126,7 @@ userspace_tests()
 		local tests_pid=$!
 		wait_event ns2 MPTCP_LIB_EVENT_ESTABLISHED 1
 		userspace_pm_add_sf $ns2 10.0.3.2 20
+		wait_event ns2 MPTCP_LIB_EVENT_SUB_ESTABLISHED 1
 		chk_mptcp_info subflows 1 subflows 1
 		chk_subflows_total 2 2
 
@@ -4158,7 +4152,7 @@ endpoint_tests()
 {
 	# subflow_rebuild_header is needed to support the implicit flag
 	# userspace pm type prevents add_addr
-	if reset "implicit EP" &&
+	if reset_with_events "implicit EP" &&
 	   continue_if mptcp_lib_kallsyms_has "subflow_rebuild_header$"; then
 		pm_nl_set_limits $ns1 2 2
 		pm_nl_set_limits $ns2 2 2
@@ -4167,7 +4161,7 @@ endpoint_tests()
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 
-		wait_mpj $ns1
+		wait_event ns2 MPTCP_LIB_EVENT_ESTABLISHED 1
 		pm_nl_check_endpoint "creation" \
 			$ns2 10.0.2.2 id 1 flags implicit
 		chk_mptcp_info subflows 1 subflows 1
@@ -4181,6 +4175,7 @@ endpoint_tests()
 		pm_nl_check_endpoint "modif is allowed" \
 			$ns2 10.0.2.2 id 1 flags signal
 		mptcp_lib_kill_group_wait $tests_pid
+		kill_events_pids
 	fi
 
 	if reset_with_tcp_filter "delete and re-add" ns2 10.0.3.2 REJECT OUTPUT &&
@@ -4194,7 +4189,7 @@ endpoint_tests()
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 
-		wait_mpj $ns2
+		wait_event ns2 MPTCP_LIB_EVENT_ESTABLISHED 1
 		pm_nl_check_endpoint "creation" \
 			$ns2 10.0.2.2 id 2 flags subflow dev ns2eth2
 		chk_subflow_nr "before delete id 2" 2
@@ -4206,7 +4201,7 @@ endpoint_tests()
 		chk_mptcp_info subflows 0 subflows 0
 
 		pm_nl_add_endpoint $ns2 10.0.2.2 id 2 dev ns2eth2 flags subflow
-		wait_mpj $ns2
+		wait_mpj 2
 		chk_subflow_nr "after re-add id 2" 2
 		chk_mptcp_info subflows 1 subflows 1
 
@@ -4218,7 +4213,7 @@ endpoint_tests()
 		ip netns exec "${ns2}" ${iptables} -D OUTPUT -s "10.0.3.2" -p tcp -j REJECT
 		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 $ns2
+		wait_mpj 3
 		chk_subflow_nr "after no reject" 3
 		chk_mptcp_info subflows 2 subflows 2
 
@@ -4230,7 +4225,7 @@ endpoint_tests()
 			chk_mptcp_info subflows 2 subflows 2 # only decr for additional sf
 
 			pm_nl_add_endpoint $ns2 10.0.1.2 id 1 dev ns2eth1 flags subflow
-			wait_mpj $ns2
+			wait_mpj $((3 + i))
 			chk_subflow_nr "after re-add id 0 ($i)" 3
 			chk_mptcp_info subflows 3 subflows 3
 		done
@@ -4272,7 +4267,7 @@ endpoint_tests()
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 
-		wait_mpj $ns2
+		wait_event ns2 MPTCP_LIB_EVENT_ESTABLISHED 1
 		pm_nl_check_endpoint "creation" \
 			$ns1 10.0.2.1 id 1 flags signal
 		chk_subflow_nr "before delete" 2
@@ -4288,7 +4283,7 @@ endpoint_tests()
 
 		pm_nl_add_endpoint $ns1 10.0.2.1 id 1 flags signal
 		pm_nl_add_endpoint $ns1 10.0.3.1 id 2 flags signal
-		wait_mpj $ns2
+		wait_mpj 3
 		chk_subflow_nr "after re-add" 3
 		chk_mptcp_info subflows 2 subflows 2
 		chk_mptcp_info add_addr_signal 2 add_addr_accepted 2
@@ -4300,7 +4295,7 @@ endpoint_tests()
 		chk_mptcp_info add_addr_signal 2 add_addr_accepted 2
 
 		pm_nl_add_endpoint $ns1 10.0.1.1 id 99 flags signal
-		wait_mpj $ns2
+		wait_mpj 4
 		chk_subflow_nr "after re-add ID 0" 3
 		chk_mptcp_info subflows 3 subflows 3
 		chk_mptcp_info add_addr_signal 3 add_addr_accepted 2
@@ -4312,7 +4307,7 @@ endpoint_tests()
 		chk_mptcp_info add_addr_signal 2 add_addr_accepted 2
 
 		pm_nl_add_endpoint $ns1 10.0.1.1 id 88 flags signal
-		wait_mpj $ns2
+		wait_mpj 5
 		chk_subflow_nr "after re-re-add ID 0" 3
 		chk_mptcp_info subflows 3 subflows 3
 		chk_mptcp_info add_addr_signal 3 add_addr_accepted 2
@@ -4361,9 +4356,9 @@ endpoint_tests()
 		wait_rm_addr $ns2 0
 		ip netns exec "${ns2}" ${iptables} -D OUTPUT -s "10.0.3.2" -p tcp -j REJECT
 		pm_nl_add_endpoint $ns2 10.0.3.2 id 3 flags subflow
-		wait_mpj $ns2
+		wait_mpj 1
 		pm_nl_add_endpoint $ns1 10.0.3.1 id 2 flags signal
-		wait_mpj $ns2
+		wait_mpj 2
 		mptcp_lib_kill_group_wait $tests_pid
 
 		join_syn_tx=3 join_connect_err=1 \