mptcp: fix subflow accounting on close

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2076832
Tested: LNST, Tier1

Upstream commit:
commit 95d686517884a403412b000361cee2b08b2ed1e6
Author: Paolo Abeni <pabeni@redhat.com>
Date:   Thu May 12 16:26:41 2022 -0700

    mptcp: fix subflow accounting on close

    If the PM closes a fully established MPJ subflow or the subflow
    creation errors out in it's early stage the subflows counter is
    not bumped accordingly.

    This change adds the missing accounting, additionally taking care
    of updating accordingly the 'accept_subflow' flag.

    Fixes: a88c9e496937 ("mptcp: do not block subflows creation on errors")
    Signed-off-by: Paolo Abeni <pabeni@redhat.com>
    Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Paolo Abeni 2022-05-18 18:11:49 +02:00
parent feeed04fe1
commit 0a22740234
3 changed files with 25 additions and 6 deletions

View File

@ -181,15 +181,14 @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk,
struct mptcp_pm_data *pm = &msk->pm;
bool update_subflows;
update_subflows = (ssk->sk_state == TCP_CLOSE) &&
(subflow->request_join || subflow->mp_join) &&
update_subflows = (subflow->request_join || subflow->mp_join) &&
mptcp_pm_is_kernel(msk);
if (!READ_ONCE(pm->work_pending) && !update_subflows)
return;
spin_lock_bh(&pm->lock);
if (update_subflows)
pm->subflows--;
__mptcp_pm_close_subflow(msk);
/* Even if this subflow is not really established, tell the PM to try
* to pick the next ones, if possible.

View File

@ -893,6 +893,20 @@ unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);
unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk);
/* called under PM lock */
static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk)
{
if (--msk->pm.subflows < mptcp_pm_get_subflows_max(msk))
WRITE_ONCE(msk->pm.accept_subflow, true);
}
static inline void mptcp_pm_close_subflow(struct mptcp_sock *msk)
{
spin_lock_bh(&msk->pm.lock);
__mptcp_pm_close_subflow(msk);
spin_unlock_bh(&msk->pm.lock);
}
void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk);
void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk);

View File

@ -1444,20 +1444,20 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
struct sockaddr_storage addr;
int remote_id = remote->id;
int local_id = loc->id;
int err = -ENOTCONN;
struct socket *sf;
struct sock *ssk;
u32 remote_token;
int addrlen;
int ifindex;
u8 flags;
int err;
if (!mptcp_is_fully_established(sk))
return -ENOTCONN;
goto err_out;
err = mptcp_subflow_create_socket(sk, &sf);
if (err)
return err;
goto err_out;
ssk = sf->sk;
subflow = mptcp_subflow_ctx(ssk);
@ -1515,6 +1515,12 @@ failed_unlink:
failed:
subflow->disposable = 1;
sock_release(sf);
err_out:
/* we account subflows before the creation, and this failures will not
* be caught by sk_state_change()
*/
mptcp_pm_close_subflow(msk);
return err;
}