linux-dev/net/mptcp/protocol.c, branch linus/master

mptcp: Do not traverse the subflow connection list without lock

2022-05-20T03:05:07Z

The MPTCP socket's conn_list (list of subflows) requires the socket lock to access. The MP_FAIL timeout code added such an access, where it would check the list of subflows both in timer context and (later) in workqueue context where the socket lock is held. Rather than check the list twice, remove the check in the timeout handler and only depend on the check in the workqueue. Also remove the MPTCP_FAIL_NO_RESPONSE flag, since mptcp_mp_fail_no_response() has insignificant overhead and can be checked on each worker run. Fixes: 49fa1919d6bc ("mptcp: reset subflow when MP_FAIL doesn't respond") Reported-by: Paolo Abeni Reviewed-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski

Revert "mptcp: add data lock for sk timers"

2022-05-16T20:11:31Z

This reverts commit 4293248c6704b854bf816aa1967e433402bee11c. Additional locks are not needed, all the touched sections are already under mptcp socket lock protection. Fixes: 4293248c6704 ("mptcp: add data lock for sk timers") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski

mptcp: never shrink offered window

2022-05-06T02:00:15Z

As per RFC, the offered MPTCP-level window should never shrink. While we currently track the right edge, we don't enforce the above constraint on the wire. Additionally, concurrent xmit on different subflows can end-up in erroneous right edge update. Address the above explicitly updating the announced window and protecting the update with an additional atomic operation (sic) Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski

mptcp: add mib for xmit window sharing

2022-05-06T02:00:15Z

Bump a counter for counter when snd_wnd is shared among subflow, for observability's sake. Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski

mptcp: really share subflow snd_wnd

2022-05-06T02:00:14Z

As per RFC, mptcp subflows use a "shared" snd_wnd: the effective window is the maximum among the current values received on all subflows. Without such feature a data transfer using multiple subflows could block. Window sharing is currently implemented in the RX side: __tcp_select_window uses the mptcp-level receive buffer to compute the announced window. That is not enough: the TCP stack will stick to the window size received on the given subflow; we need to propagate the msk window value on each subflow at xmit time. Change the packet scheduler to ignore the subflow level window and use instead the msk level one Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski

net: switch to netif_napi_add_tx()

2022-05-05T22:54:12Z

Switch net callers to the new API not requiring the NAPI_POLL_WEIGHT argument. Acked-by: Florian Fainelli Reviewed-by: Alex Elder Acked-by: Mat Martineau Acked-by: Alexandra Winter Link: https://lore.kernel.org/r/20220504163725.550782-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

mptcp: handle local addrs announced by userspace PMs

2022-05-04T09:49:31Z

This change adds an internal function to store/retrieve local addrs announced by userspace PM implementations to/from its kernel context. The function addresses the requirements of three scenarios: 1) ADD_ADDR announcements (which require that a local id be provided), 2) retrieving the local id associated with an address, and also where one may need to be assigned, and 3) reissuance of ADD_ADDRs when there's a successful match of addr/id. The list of all stored local addr entries is held under the MPTCP sock structure. Memory for these entries is allocated from the sock option buffer, so the list of addrs is bounded by optmem_max. The list if not released via REMOVE_ADDR signals is ultimately freed when the sock is destructed. Acked-by: Paolo Abeni Signed-off-by: Kishen Maloor Signed-off-by: Mat Martineau Signed-off-by: David S. Miller

mptcp: establish subflows from either end of connection

2022-05-03T23:54:55Z

This change updates internal logic to permit subflows to be established from either the client or server ends of MPTCP connections. This symmetry and added flexibility may be harnessed by PM implementations running on either end in creating new subflows. The essence of this change lies in not relying on the "server_side" flag (which continues to be available if needed). Acked-by: Paolo Abeni Signed-off-by: Kishen Maloor Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski

mptcp: reset subflow when MP_FAIL doesn't respond

2022-04-27T09:45:54Z

This patch adds a new msk->flags bit MPTCP_FAIL_NO_RESPONSE, then reuses sk_timer to trigger a check if we have not received a response from the peer after sending MP_FAIL. If the peer doesn't respond properly, reset the subflow. Signed-off-by: Geliang Tang Signed-off-by: Mat Martineau Signed-off-by: David S. Miller

mptcp: add data lock for sk timers

2022-04-27T09:45:54Z

mptcp_data_lock() needs to be held when manipulating the msk retransmit_timer or the sk sk_timer. This patch adds the data lock for the both timers. Signed-off-by: Geliang Tang Signed-off-by: Mat Martineau Signed-off-by: David S. Miller