From 4d25247d3ae486e6e4c59394487fd01523628234 Mon Sep 17 00:00:00 2001 From: Kishen Maloor Date: Mon, 2 May 2022 13:52:31 -0700 Subject: mptcp: bypass in-kernel PM restrictions for non-kernel PMs Current limits on the # of addresses/subflows must apply only to in-kernel PM managed sockets. Thus this change removes such restrictions on connections overseen by non-kernel (e.g. userspace) PMs. This change also ensures that the kernel does not record stats inside struct mptcp_pm_data updated along kernel code paths when exercised via non-kernel PMs. Additionally, address announcements are acknolwedged and subflow requests are honored only when it's deemed that a userspace path manager is active at the time. Acked-by: Paolo Abeni Signed-off-by: Kishen Maloor Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- net/mptcp/pm.c | 15 +++++++++++++-- net/mptcp/pm_netlink.c | 10 ++++++++++ net/mptcp/protocol.h | 6 ++++++ net/mptcp/subflow.c | 4 +++- 4 files changed, 32 insertions(+), 3 deletions(-) (limited to 'net/mptcp') diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 57f67578a47f..8df9cb28d970 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -87,6 +87,9 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk) unsigned int subflows_max; int ret = 0; + if (mptcp_pm_is_userspace(msk)) + return mptcp_userspace_pm_active(msk); + subflows_max = mptcp_pm_get_subflows_max(msk); pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows, @@ -179,7 +182,8 @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk, bool update_subflows; update_subflows = (ssk->sk_state == TCP_CLOSE) && - (subflow->request_join || subflow->mp_join); + (subflow->request_join || subflow->mp_join) && + mptcp_pm_is_kernel(msk); if (!READ_ONCE(pm->work_pending) && !update_subflows) return; @@ -208,7 +212,14 @@ void mptcp_pm_add_addr_received(struct mptcp_sock *msk, spin_lock_bh(&pm->lock); - if (!READ_ONCE(pm->accept_addr) || mptcp_pm_is_userspace(msk)) { + if (mptcp_pm_is_userspace(msk)) { + if (mptcp_userspace_pm_active(msk)) { + mptcp_pm_announce_addr(msk, addr, true); + mptcp_pm_add_addr_send_ack(msk); + } else { + __MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP); + } + } else if (!READ_ONCE(pm->accept_addr)) { mptcp_pm_announce_addr(msk, addr, true); mptcp_pm_add_addr_send_ack(msk); } else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) { diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 473e5aa7baf4..d2b63529bfee 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -805,6 +805,9 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, if (!removed) continue; + if (!mptcp_pm_is_kernel(msk)) + continue; + if (rm_type == MPTCP_MIB_RMADDR) { msk->pm.add_addr_accepted--; WRITE_ONCE(msk->pm.accept_addr, true); @@ -1855,6 +1858,13 @@ static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gf nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp); } +bool mptcp_userspace_pm_active(const struct mptcp_sock *msk) +{ + return genl_has_listeners(&mptcp_genl_family, + sock_net((const struct sock *)msk), + MPTCP_PM_EV_GRP_OFFSET); +} + static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk) { const struct inet_sock *issk = inet_sk(ssk); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 54d2b3b2d100..85390146944d 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -784,6 +784,7 @@ void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp); void mptcp_event_addr_announced(const struct mptcp_sock *msk, const struct mptcp_addr_info *info); void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id); +bool mptcp_userspace_pm_active(const struct mptcp_sock *msk); static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk) { @@ -811,6 +812,11 @@ static inline bool mptcp_pm_is_userspace(const struct mptcp_sock *msk) return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_USERSPACE; } +static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk) +{ + return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_KERNEL; +} + static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port) { u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE; diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 75c824b67ca9..9567231a4bfa 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -62,7 +62,9 @@ static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2, static bool mptcp_can_accept_new_subflow(const struct mptcp_sock *msk) { return mptcp_is_fully_established((void *)msk) && - READ_ONCE(msk->pm.accept_subflow); + ((mptcp_pm_is_userspace(msk) && + mptcp_userspace_pm_active(msk)) || + READ_ONCE(msk->pm.accept_subflow)); } /* validate received token and create truncated hmac and nonce for SYN-ACK */ -- cgit v1.2.3