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 <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index ad837da..3aedad5 100644 (file)
--- 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);

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 3d84e0b..5c45602 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -833,6 +833,7 @@ static void mptcp_close(struct sock *sk, long timeout)
        }
 
        mptcp_cancel_work(sk);
+       mptcp_pm_close(msk);
 
        __skb_queue_purge(&sk->sk_receive_queue);
 

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index df134ac..209bdaa 100644 (file)
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -330,6 +330,7 @@ void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
 
 void mptcp_pm_init(void);
 void mptcp_pm_data_init(struct mptcp_sock *msk);
+void mptcp_pm_close(struct mptcp_sock *msk);
 void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
 void mptcp_pm_fully_established(struct mptcp_sock *msk);
 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);