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>
This commit is contained in:
Peter Krystad 2020-03-27 14:48:41 -07:00 committed by David S. Miller
parent ec3edaa7ca
commit 926bdeab55
3 changed files with 129 additions and 5 deletions

View File

@ -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);

View File

@ -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);

View File

@ -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);