Commit d40831b0 authored by Paolo Abeni's avatar Paolo Abeni
Browse files

Merge branch 'mptcp-sync-the-msk-sndbuf-at-accept-time' 



Matthieu Baerts says:

====================
mptcp: sync the msk->sndbuf at accept() time

On passive MPTCP connections, the MPTCP socket send buffer doesn't have
the expected size at accept() time.

Patch 1 fixes the regression introduced in v6.7, while the following one
validates the fix in the selftests.

Signed-off-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
====================

Link: https://patch.msgid.link/20260420-net-mptcp-sync-sndbuf-accept-v1-0-e3523e3aeb44@kernel.org


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parents 1cb36e25 d0576eb8

net/mptcp/protocol.c

+1 −1
Original line number Diff line number Diff line
@@ -3594,7 +3594,6 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk, 
	 * uses the correct data

	 */

	mptcp_copy_inaddrs(nsk, ssk);

	__mptcp_propagate_sndbuf(nsk, ssk);



	mptcp_rcv_space_init(msk, ssk);

	msk->rcvq_space.time = mptcp_stamp();
@@ -4252,6 +4251,7 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, 


		mptcp_graft_subflows(newsk);

		mptcp_rps_record_subflows(msk);

		__mptcp_propagate_sndbuf(newsk, mptcp_subflow_tcp_sock(subflow));



		/* Do late cleanup for the first subflow as necessary. Also

		 * deal with bad peers not doing a complete shutdown.

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

+28 −0
Original line number Diff line number Diff line
@@ -322,6 +322,33 @@ wait_connected() 
	done

}



chk_sndbuf()

{

	local server_sndbuf client_sndbuf msg

	local port=${1}



	msg="....chk sndbuf server/client"

	server_sndbuf=$(ss -N "${ns}" -inmHM "sport" "${port}" | \

			sed -n 's/.*tb\([0-9]\+\).*/\1/p')

	client_sndbuf=$(ss -N "${ns}" -inmHM "dport" "${port}" | \

			sed -n 's/.*tb\([0-9]\+\).*/\1/p')



	mptcp_lib_print_title "${msg}"

	if [ -z "${server_sndbuf}" ] || [ -z "${client_sndbuf}" ]; then

		mptcp_lib_pr_fail "sndbuf S=${server_sndbuf} C=${client_sndbuf}"

		mptcp_lib_result_fail "${msg}"

		ret=${KSFT_FAIL}

	elif [ "${server_sndbuf}" != "${client_sndbuf}" ]; then

		mptcp_lib_pr_fail "sndbuf S=${server_sndbuf} != C=${client_sndbuf}"

		mptcp_lib_result_fail "${msg}"

		ret=${KSFT_FAIL}

	else

		mptcp_lib_pr_ok

		mptcp_lib_result_pass "${msg}"

	fi

}





trap cleanup EXIT

mptcp_lib_ns_init ns
@@ -341,6 +368,7 @@ echo "b" | \ 
				127.0.0.1 >/dev/null &

wait_connected $ns 10000

chk_msk_nr 2 "after MPC handshake"

chk_sndbuf 10000

chk_last_time_info 10000

chk_msk_remote_key_nr 2 "....chk remote_key"

chk_msk_fallback_nr 0 "....chk no fallback"