From 926bdeab5535856e3a164545630149f212d3482d Mon Sep 17 00:00:00 2001 From: Peter Krystad Date: Fri, 27 Mar 2020 14:48:41 -0700 Subject: mptcp: Implement path manager interface commands Fill in more path manager functionality by adding a worker function and modifying the related stub functions to schedule the worker. Co-developed-by: Florian Westphal Signed-off-by: Florian Westphal Co-developed-by: Paolo Abeni Signed-off-by: Paolo Abeni Signed-off-by: Peter Krystad Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/pm.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 127 insertions(+), 5 deletions(-) (limited to 'net/mptcp/pm.c') diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index ad837da0193d..3aedad58778c 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -15,7 +15,11 @@ static struct workqueue_struct *pm_wq; int mptcp_pm_announce_addr(struct mptcp_sock *msk, const struct mptcp_addr_info *addr) { - return -ENOTSUPP; + pr_debug("msk=%p, local_id=%d", msk, addr->id); + + msk->pm.local = *addr; + WRITE_ONCE(msk->pm.addr_signal, true); + return 0; } int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id) @@ -41,13 +45,58 @@ void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side) bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk) { - pr_debug("msk=%p", msk); - return false; + struct mptcp_pm_data *pm = &msk->pm; + int ret; + + pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows, + pm->subflows_max, READ_ONCE(pm->accept_subflow)); + + /* try to avoid acquiring the lock below */ + if (!READ_ONCE(pm->accept_subflow)) + return false; + + spin_lock_bh(&pm->lock); + ret = pm->subflows < pm->subflows_max; + if (ret && ++pm->subflows == pm->subflows_max) + WRITE_ONCE(pm->accept_subflow, false); + spin_unlock_bh(&pm->lock); + + return ret; +} + +/* return true if the new status bit is currently cleared, that is, this event + * can be server, eventually by an already scheduled work + */ +static bool mptcp_pm_schedule_work(struct mptcp_sock *msk, + enum mptcp_pm_status new_status) +{ + pr_debug("msk=%p status=%x new=%lx", msk, msk->pm.status, + BIT(new_status)); + if (msk->pm.status & BIT(new_status)) + return false; + + msk->pm.status |= BIT(new_status); + if (queue_work(pm_wq, &msk->pm.work)) + sock_hold((struct sock *)msk); + return true; } void mptcp_pm_fully_established(struct mptcp_sock *msk) { + struct mptcp_pm_data *pm = &msk->pm; + pr_debug("msk=%p", msk); + + /* try to avoid acquiring the lock below */ + if (!READ_ONCE(pm->work_pending)) + return; + + spin_lock_bh(&pm->lock); + + if (READ_ONCE(pm->work_pending)) + mptcp_pm_schedule_work(msk, MPTCP_PM_ESTABLISHED); + + spin_unlock_bh(&pm->lock); } void mptcp_pm_connection_closed(struct mptcp_sock *msk) @@ -58,7 +107,19 @@ void mptcp_pm_connection_closed(struct mptcp_sock *msk) void mptcp_pm_subflow_established(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow) { + struct mptcp_pm_data *pm = &msk->pm; + pr_debug("msk=%p", msk); + + if (!READ_ONCE(pm->work_pending)) + return; + + spin_lock_bh(&pm->lock); + + if (READ_ONCE(pm->work_pending)) + mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED); + + spin_unlock_bh(&pm->lock); } void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id) @@ -69,7 +130,23 @@ void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id) void mptcp_pm_add_addr_received(struct mptcp_sock *msk, const struct mptcp_addr_info *addr) { - pr_debug("msk=%p, remote_id=%d", msk, addr->id); + struct mptcp_pm_data *pm = &msk->pm; + + pr_debug("msk=%p remote_id=%d accept=%d", msk, addr->id, + READ_ONCE(pm->accept_addr)); + + /* avoid acquiring the lock if there is no room for fouther addresses */ + if (!READ_ONCE(pm->accept_addr)) + return; + + spin_lock_bh(&pm->lock); + + /* be sure there is something to signal re-checking under PM lock */ + if (READ_ONCE(pm->accept_addr) && + mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) + pm->remote = *addr; + + spin_unlock_bh(&pm->lock); } /* path manager helpers */ @@ -77,7 +154,24 @@ void mptcp_pm_add_addr_received(struct mptcp_sock *msk, bool mptcp_pm_addr_signal(struct mptcp_sock *msk, unsigned int remaining, struct mptcp_addr_info *saddr) { - return false; + int ret = false; + + spin_lock_bh(&msk->pm.lock); + + /* double check after the lock is acquired */ + if (!mptcp_pm_should_signal(msk)) + goto out_unlock; + + if (remaining < mptcp_add_addr_len(msk->pm.local.family)) + goto out_unlock; + + *saddr = msk->pm.local; + WRITE_ONCE(msk->pm.addr_signal, false); + ret = true; + +out_unlock: + spin_unlock_bh(&msk->pm.lock); + return ret; } int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc) @@ -87,6 +181,28 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc) static void pm_worker(struct work_struct *work) { + struct mptcp_pm_data *pm = container_of(work, struct mptcp_pm_data, + work); + struct mptcp_sock *msk = container_of(pm, struct mptcp_sock, pm); + struct sock *sk = (struct sock *)msk; + + lock_sock(sk); + spin_lock_bh(&msk->pm.lock); + + pr_debug("msk=%p status=%x", msk, pm->status); + if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) { + pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED); + } + if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) { + pm->status &= ~BIT(MPTCP_PM_ESTABLISHED); + } + if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) { + pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED); + } + + spin_unlock_bh(&msk->pm.lock); + release_sock(sk); + sock_put(sk); } void mptcp_pm_data_init(struct mptcp_sock *msk) @@ -105,6 +221,12 @@ void mptcp_pm_data_init(struct mptcp_sock *msk) INIT_WORK(&msk->pm.work, pm_worker); } +void mptcp_pm_close(struct mptcp_sock *msk) +{ + if (cancel_work_sync(&msk->pm.work)) + sock_put((struct sock *)msk); +} + void mptcp_pm_init(void) { pm_wq = alloc_workqueue("pm_wq", WQ_UNBOUND | WQ_MEM_RECLAIM, 8); -- cgit v1.2.3