Merge branch 'mptcp-receive-path-improvement'

Matthieu Baerts says:

====================
mptcp: receive path improvement

This series includes several changes to the MPTCP RX path. The main
goals are improving the RX performances, and increase the long term
maintainability.

Some changes reflects recent(ish) improvements introduced in the TCP
stack: patch 1, 2 and 3 are the MPTCP counter part of SKB deferral free
and auto-tuning improvements. Note that patch 3 could possibly fix
additional issues, and overall such patch should protect from similar
issues to arise in the future.

Patches 4-7 are aimed at introducing the socket backlog usage which will
be done in a later series to process the packets received by the
different subflows while the msk socket is owned.

Patch 8 is not related to the RX path, but it contains additional tests
for new features recently introduced in net-next.
====================

Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-0-5da266aa9c1a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 78 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index a94b3960ad5e..c90d8e8b95cb 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -2320,6 +2320,74 @@ signal_address_tests()
 	fi
 }
 
+laminar_endp_tests()
+{
+	# no laminar endpoints: routing rules are used
+	if reset_with_tcp_filter "without a laminar endpoint" ns1 10.0.2.2 REJECT &&
+	   mptcp_lib_kallsyms_has "mptcp_pm_get_endp_laminar_max$"; then
+		pm_nl_set_limits $ns1 0 2
+		pm_nl_set_limits $ns2 2 2
+		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal
+		run_tests $ns1 $ns2 10.0.1.1
+		join_syn_tx=1 \
+			chk_join_nr 0 0 0
+		chk_add_nr 1 1
+	fi
+
+	# laminar endpoints: this endpoint is used
+	if reset_with_tcp_filter "with a laminar endpoint" ns1 10.0.2.2 REJECT &&
+	   mptcp_lib_kallsyms_has "mptcp_pm_get_endp_laminar_max$"; then
+		pm_nl_set_limits $ns1 0 2
+		pm_nl_set_limits $ns2 2 2
+		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal
+		pm_nl_add_endpoint $ns2 10.0.3.2 flags laminar
+		run_tests $ns1 $ns2 10.0.1.1
+		chk_join_nr 1 1 1
+		chk_add_nr 1 1
+	fi
+
+	# laminar endpoints: these endpoints are used
+	if reset_with_tcp_filter "with multiple laminar endpoints" ns1 10.0.2.2 REJECT &&
+	   mptcp_lib_kallsyms_has "mptcp_pm_get_endp_laminar_max$"; then
+		pm_nl_set_limits $ns1 0 2
+		pm_nl_set_limits $ns2 2 2
+		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal
+		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal
+		pm_nl_add_endpoint $ns2 dead:beef:3::2 flags laminar
+		pm_nl_add_endpoint $ns2 10.0.3.2 flags laminar
+		pm_nl_add_endpoint $ns2 10.0.4.2 flags laminar
+		run_tests $ns1 $ns2 10.0.1.1
+		chk_join_nr 2 2 2
+		chk_add_nr 2 2
+	fi
+
+	# laminar endpoints: only one endpoint is used
+	if reset_with_tcp_filter "single laminar endpoint" ns1 10.0.2.2 REJECT &&
+	   mptcp_lib_kallsyms_has "mptcp_pm_get_endp_laminar_max$"; then
+		pm_nl_set_limits $ns1 0 2
+		pm_nl_set_limits $ns2 2 2
+		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal
+		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal
+		pm_nl_add_endpoint $ns2 10.0.3.2 flags laminar
+		run_tests $ns1 $ns2 10.0.1.1
+		chk_join_nr 1 1 1
+		chk_add_nr 2 2
+	fi
+
+	# laminar endpoints: subflow and laminar flags
+	if reset_with_tcp_filter "sublow + laminar endpoints" ns1 10.0.2.2 REJECT &&
+	   mptcp_lib_kallsyms_has "mptcp_pm_get_endp_laminar_max$"; then
+		pm_nl_set_limits $ns1 0 4
+		pm_nl_set_limits $ns2 2 4
+		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal
+		pm_nl_add_endpoint $ns2 10.0.1.2 flags subflow,laminar
+		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow,laminar
+		run_tests $ns1 $ns2 10.0.1.1
+		chk_join_nr 1 1 1
+		chk_add_nr 1 1
+	fi
+}
+
 link_failure_tests()
 {
 	# accept and use add_addr with additional subflows and link loss
@@ -4109,6 +4177,7 @@ all_tests_sorted=(
 	f@subflows_tests
 	e@subflows_error_tests
 	s@signal_address_tests
+	L@laminar_endp_tests
 	l@link_failure_tests
 	t@add_addr_timeout_tests
 	r@remove_tests
diff --git a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
index d4981b76693b..65b374232ff5 100644
--- a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
+++ b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
@@ -830,6 +830,8 @@ int add_addr(int fd, int pm_family, int argc, char *argv[])
 					flags |= MPTCP_PM_ADDR_FLAG_SUBFLOW;
 				else if (!strcmp(tok, "signal"))
 					flags |= MPTCP_PM_ADDR_FLAG_SIGNAL;
+				else if (!strcmp(tok, "laminar"))
+					flags |= MPTCP_PM_ADDR_FLAG_LAMINAR;
 				else if (!strcmp(tok, "backup"))
 					flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
 				else if (!strcmp(tok, "fullmesh"))
@@ -1018,6 +1020,13 @@ static void print_addr(struct rtattr *attrs, int len)
 					printf(",");
 			}
 
+			if (flags & MPTCP_PM_ADDR_FLAG_LAMINAR) {
+				printf("laminar");
+				flags &= ~MPTCP_PM_ADDR_FLAG_LAMINAR;
+				if (flags)
+					printf(",");
+			}
+
 			if (flags & MPTCP_PM_ADDR_FLAG_BACKUP) {
 				printf("backup");
 				flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP;