From c157bbe776b799fba885577e193e94068cefe9c7 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Mon, 11 Jul 2022 12:16:31 -0700 Subject: [PATCH] mptcp: allow the in kernel PM to set MPC subflow priority Any local endpoints configured on the address matching the MPC subflow are currently ignored. Specifically, setting a backup flag on them has no effect on the first subflow, as the MPC handshake can't carry such info. This change refactors the MPC endpoint id accounting to additionally fetch the priority info from the relevant endpoint and eventually trigger the MP_PRIO handshake as needed. As a result, the MPC subflow now switches to backup priority after that the MPTCP socket is fully established, according to the local endpoint configuration. Reviewed-by: Mat Martineau Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- net/mptcp/pm_netlink.c | 37 +++++++++++++++---------------------- 1 file changed, 15 insertions(+), 22 deletions(-) diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index fe8e22aff7d2..b767a336ad98 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -514,30 +514,14 @@ __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info, struct mptcp_pm_addr_entry *entry; list_for_each_entry(entry, &pernet->local_addr_list, list) { - if ((!lookup_by_id && mptcp_addresses_equal(&entry->addr, info, true)) || + if ((!lookup_by_id && + mptcp_addresses_equal(&entry->addr, info, entry->addr.port)) || (lookup_by_id && entry->addr.id == info->id)) return entry; } return NULL; } -static int -lookup_id_by_addr(const struct pm_nl_pernet *pernet, const struct mptcp_addr_info *addr) -{ - const struct mptcp_pm_addr_entry *entry; - int ret = -1; - - rcu_read_lock(); - list_for_each_entry(entry, &pernet->local_addr_list, list) { - if (mptcp_addresses_equal(&entry->addr, addr, entry->addr.port)) { - ret = entry->addr.id; - break; - } - } - rcu_read_unlock(); - return ret; -} - static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) { struct sock *sk = (struct sock *)msk; @@ -555,13 +539,22 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) /* do lazy endpoint usage accounting for the MPC subflows */ if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) { + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(msk->first); + struct mptcp_pm_addr_entry *entry; struct mptcp_addr_info mpc_addr; - int mpc_id; + bool backup = false; local_address((struct sock_common *)msk->first, &mpc_addr); - mpc_id = lookup_id_by_addr(pernet, &mpc_addr); - if (mpc_id >= 0) - __clear_bit(mpc_id, msk->pm.id_avail_bitmap); + rcu_read_lock(); + entry = __lookup_addr(pernet, &mpc_addr, false); + if (entry) { + __clear_bit(entry->addr.id, msk->pm.id_avail_bitmap); + backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP); + } + rcu_read_unlock(); + + if (backup) + mptcp_pm_send_ack(msk, subflow, true, backup); msk->pm.status |= BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED); }