mptcp: pm: in-kernel: increase endpoints limit

The endpoints are managed in a list which was limited to 8 entries.

This limit can be too small in some cases: by having the same limit as
the number of subflows, it might not allow creating all expected
subflows when having a mix of v4 and v6 addresses that can all use MPTCP
on v4/v6 only networks.

While increasing the limit above the new subflows one, why not using the
technical limit: 255. Indeed, the endpoint will each have an ID that
will be used on the wire, limited to u8, and the ID 0 is reserved to the
initial subflow.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260508-net-next-mptcp-pm-inc-limits-v1-4-c84e3fdf9b6a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index ea3a7ea82013ae772313031091f09ab81ce516e7..4ba4346d7adc7c962a0bcaf31e25cbe396abd467 100644 (file)
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -746,7 +746,7 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
         */
        if (pernet->next_id == MPTCP_PM_MAX_ADDR_ID)
                pernet->next_id = 1;
-       if (pernet->endpoints >= MPTCP_PM_ADDR_MAX) {
+       if (pernet->endpoints == MPTCP_PM_MAX_ADDR_ID) {
                ret = -ERANGE;
                goto out;
        }