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2023-10-25mptcp: use copy_from_iter helpers on transmitPaolo Abeni1-4/+15
The perf traces show an high cost for the MPTCP transmit path memcpy. It turn out that the helper currently in use carries quite a bit of unneeded overhead, e.g. to map/unmap the memory pages. Moving to the 'copy_from_iter' variant removes such overhead and additionally gains the no-cache support. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-2-v1-6-9dc60939d371@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-25mptcp: give rcvlowat some lovePaolo Abeni1-13/+11
The MPTCP protocol allow setting sk_rcvlowat, but the value there is currently ignored. Additionally, the default subflows sk_rcvlowat basically disables per subflow delayed ack: the MPTCP protocol move the incoming data from the subflows into the msk socket as soon as the TCP stacks invokes the subflow data_ready callback. Later, when __tcp_ack_snd_check() takes action, the subflow-level copied_seq matches rcv_nxt, and that mandate for an immediate ack. Let the mptcp receive path be aware of such threshold, explicitly tracking the amount of data available to be ready and checking vs sk_rcvlowat in mptcp_poll() and before waking-up readers. Additionally implement the set_rcvlowat() callback, to properly handle the rcvbuf auto-tuning on sk_rcvlowat changes. Finally to properly handle delayed ack, force the subflow level threshold to 0 and instead explicitly ask for an immediate ack when the msk level th is not reached. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-2-v1-5-9dc60939d371@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-25mptcp: add a new sysctl for make after break timeoutPaolo Abeni1-3/+3
The MPTCP protocol allows sockets with no alive subflows to stay in ESTABLISHED status for and user-defined timeout, to allow for later subflows creation. Currently such timeout is constant - TCP_TIMEWAIT_LEN. Let the user-space configure them via a newly added sysctl, to better cope with busy servers and simplify (make them faster) the relevant pktdrill tests. Note that the new know does not apply to orphaned MPTCP socket waiting for the data_fin handshake completion: they always wait TCP_TIMEWAIT_LEN. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-2-v1-1-9dc60939d371@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-19mptcp: avoid sending RST when closing the initial subflowGeliang Tang1-6/+22
When closing the first subflow, the MPTCP protocol unconditionally calls tcp_disconnect(), which in turn generates a reset if the subflow is established. That is unexpected and different from what MPTCP does with MPJ subflows, where resets are generated only on FASTCLOSE and other edge scenarios. We can't reuse for the first subflow the same code in place for MPJ subflows, as MPTCP clean them up completely via a tcp_close() call, while must keep the first subflow socket alive for later re-usage, due to implementation constraints. This patch adds a new helper __mptcp_subflow_disconnect() that encapsulates, a logic similar to tcp_close, issuing a reset only when the MPTCP_CF_FASTCLOSE flag is set, and performing a clean shutdown otherwise. Fixes: c2b2ae3925b6 ("mptcp: handle correctly disconnect() failures") Cc: stable@vger.kernel.org Reviewed-by: Matthieu Baerts <matttbe@kernel.org> Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231018-send-net-20231018-v1-4-17ecb002e41d@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-19mptcp: more conservative check for zero probesPaolo Abeni1-7/+1
Christoph reported that the MPTCP protocol can find the subflow-level write queue unexpectedly not empty while crafting a zero-window probe, hitting a warning: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 188 at net/mptcp/protocol.c:1312 mptcp_sendmsg_frag+0xc06/0xe70 Modules linked in: CPU: 0 PID: 188 Comm: kworker/0:2 Not tainted 6.6.0-rc2-g1176aa719d7a #47 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 Workqueue: events mptcp_worker RIP: 0010:mptcp_sendmsg_frag+0xc06/0xe70 net/mptcp/protocol.c:1312 RAX: 47d0530de347ff6a RBX: 47d0530de347ff6b RCX: ffff8881015d3c00 RDX: ffff8881015d3c00 RSI: 47d0530de347ff6b RDI: 47d0530de347ff6b RBP: 47d0530de347ff6b R08: ffffffff8243c6a8 R09: ffffffff82042d9c R10: 0000000000000002 R11: ffffffff82056850 R12: ffff88812a13d580 R13: 0000000000000001 R14: ffff88812b375e50 R15: ffff88812bbf3200 FS: 0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000695118 CR3: 0000000115dfc001 CR4: 0000000000170ef0 Call Trace: <TASK> __subflow_push_pending+0xa4/0x420 net/mptcp/protocol.c:1545 __mptcp_push_pending+0x128/0x3b0 net/mptcp/protocol.c:1614 mptcp_release_cb+0x218/0x5b0 net/mptcp/protocol.c:3391 release_sock+0xf6/0x100 net/core/sock.c:3521 mptcp_worker+0x6e8/0x8f0 net/mptcp/protocol.c:2746 process_scheduled_works+0x341/0x690 kernel/workqueue.c:2630 worker_thread+0x3a7/0x610 kernel/workqueue.c:2784 kthread+0x143/0x180 kernel/kthread.c:388 ret_from_fork+0x4d/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:304 </TASK> The root cause of the issue is that expectations are wrong: e.g. due to MPTCP-level re-injection we can hit the critical condition. Explicitly avoid the zero-window probe when the subflow write queue is not empty and drop the related warnings. Reported-by: Christoph Paasch <cpaasch@apple.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/444 Fixes: f70cad1085d1 ("mptcp: stop relying on tcp_tx_skb_cache") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231018-send-net-20231018-v1-3-17ecb002e41d@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-14tcp: allow again tcp_disconnect() when threads are waitingPaolo Abeni1-7/+0
As reported by Tom, .NET and applications build on top of it rely on connect(AF_UNSPEC) to async cancel pending I/O operations on TCP socket. The blamed commit below caused a regression, as such cancellation can now fail. As suggested by Eric, this change addresses the problem explicitly causing blocking I/O operation to terminate immediately (with an error) when a concurrent disconnect() is executed. Instead of tracking the number of threads blocked on a given socket, track the number of disconnect() issued on such socket. If such counter changes after a blocking operation releasing and re-acquiring the socket lock, error out the current operation. Fixes: 4faeee0cf8a5 ("tcp: deny tcp_disconnect() when threads are waiting") Reported-by: Tom Deseyn <tdeseyn@redhat.com> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1886305 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/f3b95e47e3dbed840960548aebaa8d954372db41.1697008693.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-05mptcp: fix delegated action racesPaolo Abeni1-14/+14
The delegated action infrastructure is prone to the following race: different CPUs can try to schedule different delegated actions on the same subflow at the same time. Each of them will check different bits via mptcp_subflow_delegate(), and will try to schedule the action on the related per-cpu napi instance. Depending on the timing, both can observe an empty delegated list node, causing the same entry to be added simultaneously on two different lists. The root cause is that the delegated actions infra does not provide a single synchronization point. Address the issue reserving an additional bit to mark the subflow as scheduled for delegation. Acquiring such bit guarantee the caller to own the delegated list node, and being able to safely schedule the subflow. Clear such bit only when the subflow scheduling is completed, ensuring proper barrier in place. Additionally swap the meaning of the delegated_action bitmask, to allow the usage of the existing helper to set multiple bit at once. Fixes: bcd97734318d ("mptcp: use delegate action to schedule 3rd ack retrans") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231004-send-net-20231004-v1-1-28de4ac663ae@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-09-18mptcp: fix dangling connection hang-upPaolo Abeni1-44/+42
According to RFC 8684 section 3.3: A connection is not closed unless [...] or an implementation-specific connection-level send timeout. Currently the MPTCP protocol does not implement such timeout, and connection timing-out at the TCP-level never move to close state. Introduces a catch-up condition at subflow close time to move the MPTCP socket to close, too. That additionally allows removing similar existing inside the worker. Finally, allow some additional timeout for plain ESTABLISHED mptcp sockets, as the protocol allows creating new subflows even at that point and making the connection functional again. This issue is actually present since the beginning, but it is basically impossible to solve without a long chain of functional pre-requisites topped by commit bbd49d114d57 ("mptcp: consolidate transition to TCP_CLOSE in mptcp_do_fastclose()"). When backporting this current patch, please also backport this other commit as well. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/430 Fixes: e16163b6e2b7 ("mptcp: refactor shutdown and close") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-18mptcp: rename timer related helper to less confusing namesPaolo Abeni1-21/+21
The msk socket uses to different timeout to track close related events and retransmissions. The existing helpers do not indicate clearly which timer they actually touch, making the related code quite confusing. Change the existing helpers name to avoid such confusion. No functional change intended. This patch is linked to the next one ("mptcp: fix dangling connection hang-up"). The two patches are supposed to be backported together. Cc: stable@vger.kernel.org # v5.11+ Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-18mptcp: process pending subflow error on closePaolo Abeni1-29/+34
On incoming TCP reset, subflow closing could happen before error propagation. That in turn could cause the socket error being ignored, and a missing socket state transition, as reported by Daire-Byrne. Address the issues explicitly checking for subflow socket error at close time. To avoid code duplication, factor-out of __mptcp_error_report() a new helper implementing the relevant bits. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/429 Fixes: 15cc10453398 ("mptcp: deliver ssk errors to msk") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-18mptcp: move __mptcp_error_report in protocol.cPaolo Abeni1-0/+36
This will simplify the next patch ("mptcp: process pending subflow error on close"). No functional change intended. Cc: stable@vger.kernel.org # v5.12+ Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-01mptcp: annotate data-races around msk->rmem_fwd_allocEric Dumazet1-6/+13
msk->rmem_fwd_alloc can be read locklessly. Add mptcp_rmem_fwd_alloc_add(), similar to sk_forward_alloc_add(), and appropriate READ_ONCE()/WRITE_ONCE() annotations. Fixes: 6511882cdd82 ("mptcp: allocate fwd memory separately on the rx and tx path") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-01net: annotate data-races around sk->sk_forward_allocEric Dumazet1-3/+3
Every time sk->sk_forward_alloc is read locklessly, add a READ_ONCE(). Add sk_forward_alloc_add() helper to centralize updates, to reduce number of WRITE_ONCE(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-23mptcp: register default schedulerGeliang Tang1-0/+1
This patch defines the default packet scheduler mptcp_sched_default. Register it in mptcp_sched_init(), which is invoked in mptcp_proto_init(). Skip deleting this default scheduler in mptcp_unregister_scheduler(). Set msk->sched to the default scheduler when the input parameter of mptcp_init_sched() is NULL. Invoke mptcp_sched_default_get_subflow in get_send() and get_retrans() if the defaut scheduler is set or msk->sched is NULL. Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20230821-upstream-net-next-20230818-v1-10-0c860fb256a8@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-23mptcp: use get_retrans wrapperGeliang Tang1-28/+37
This patch adds the multiple subflows support for __mptcp_retrans(). Use get_retrans() wrapper instead of mptcp_subflow_get_retrans() in it. Check the subflow scheduled flags to test which subflow or subflows are picked by the scheduler, use them to send data. Move msk_owned_by_me() and fallback checks into get_retrans() wrapper from mptcp_subflow_get_retrans(). Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20230821-upstream-net-next-20230818-v1-9-0c860fb256a8@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-23mptcp: use get_send wrapperGeliang Tang1-45/+68
This patch adds the multiple subflows support for __mptcp_push_pending and __mptcp_subflow_push_pending. Use get_send() wrapper instead of mptcp_subflow_get_send() in them. Check the subflow scheduled flags to test which subflow or subflows are picked by the scheduler, use them to send data. Move msk_owned_by_me() and fallback checks into get_send() wrapper from mptcp_subflow_get_send(). This commit allows the scheduler to set the subflow->scheduled bit in multiple subflows, but it does not allow for sending redundant data. Multiple scheduled subflows will send sequential data on each subflow. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20230821-upstream-net-next-20230818-v1-8-0c860fb256a8@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-23mptcp: add scheduler wrappersGeliang Tang1-2/+2
This patch defines two packet scheduler wrappers mptcp_sched_get_send() and mptcp_sched_get_retrans(), invoke get_subflow() of msk->sched in them. Set data->reinject to true in mptcp_sched_get_retrans(), set it false in mptcp_sched_get_send(). If msk->sched is NULL, use default functions mptcp_subflow_get_send() and mptcp_subflow_get_retrans() to send data. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20230821-upstream-net-next-20230818-v1-7-0c860fb256a8@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-23mptcp: add sched in mptcp_sockGeliang Tang1-0/+8
This patch adds a new struct member sched in struct mptcp_sock. And two helpers mptcp_init_sched() and mptcp_release_sched() to init and release it. Init it with the sysctl scheduler in mptcp_init_sock(), copy the scheduler from the parent in mptcp_sk_clone(), and release it in __mptcp_destroy_sock(). Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20230821-upstream-net-next-20230818-v1-5-0c860fb256a8@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-23mptcp: drop last_snd and MPTCP_RESET_SCHEDULERGeliang Tang1-10/+1
Since the burst check conditions have moved out of the function mptcp_subflow_get_send(), it makes all msk->last_snd useless. This patch drops them as well as the macro MPTCP_RESET_SCHEDULER. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20230821-upstream-net-next-20230818-v1-2-0c860fb256a8@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-23mptcp: refactor push_pending logicGeliang Tang1-72/+81
To support redundant package schedulers more easily, this patch refactors __mptcp_push_pending() logic from: For each dfrag: While sends succeed: Call the scheduler (selects subflow and msk->snd_burst) Update subflow locks (push/release/acquire as needed) Send the dfrag data with mptcp_sendmsg_frag() Update already_sent, snd_nxt, snd_burst Update msk->first_pending Push/release on final subflow -> While first_pending isn't empty: Call the scheduler (selects subflow and msk->snd_burst) Update subflow locks (push/release/acquire as needed) For each pending dfrag: While sends succeed: Send the dfrag data with mptcp_sendmsg_frag() Update already_sent, snd_nxt, snd_burst Update msk->first_pending Break if required by msk->snd_burst / etc Push/release on final subflow Refactors __mptcp_subflow_push_pending logic from: For each dfrag: While sends succeed: Call the scheduler (selects subflow and msk->snd_burst) Send the dfrag data with mptcp_subflow_delegate(), break Send the dfrag data with mptcp_sendmsg_frag() Update dfrag->already_sent, msk->snd_nxt, msk->snd_burst Update msk->first_pending -> While first_pending isn't empty: Call the scheduler (selects subflow and msk->snd_burst) Send the dfrag data with mptcp_subflow_delegate(), break Send the dfrag data with mptcp_sendmsg_frag() For each pending dfrag: While sends succeed: Send the dfrag data with mptcp_sendmsg_frag() Update already_sent, snd_nxt, snd_burst Update msk->first_pending Break if required by msk->snd_burst / etc Move the duplicate code from __mptcp_push_pending() and __mptcp_subflow_push_pending() into a new helper function, named __subflow_push_pending(). Simplify __mptcp_push_pending() and __mptcp_subflow_push_pending() by invoking this helper. Also move the burst check conditions out of the function mptcp_subflow_get_send(), check them in __subflow_push_pending() in the inner "for each pending dfrag" loop. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20230821-upstream-net-next-20230818-v1-1-0c860fb256a8@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-16inet: move inet->defer_connect to inet->inet_flagsEric Dumazet1-4/+6
Make room in struct inet_sock by removing this bit field, using one available bit in inet_flags instead. Also move local_port_range to fill the resulting hole, saving 8 bytes on 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-14mptcp: Remove unnecessary test for __mptcp_init_sock()Kuniyuki Iwashima1-7/+2
__mptcp_init_sock() always returns 0 because mptcp_init_sock() used to return the value directly. But after commit 18b683bff89d ("mptcp: queue data for mptcp level retransmission"), __mptcp_init_sock() need not return value anymore. Let's remove the unnecessary test for __mptcp_init_sock() and make it return void. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-14mptcp: get rid of msk->subflowPaolo Abeni1-19/+6
Such field is now unused just as a flag to control the first subflow deletion at close() time. Introduce a new bit flag for that and finally drop the mentioned field. As an intended side effect, now the first subflow sock is not freed before close() even for passive sockets. The msk has no open/active subflows if the first one is closed and the subflow list is singular, update accordingly the state check in mptcp_stream_accept(). Among other benefits, the subflow removal, reduces the amount of memory used on the client side for each mptcp connection, allows passive sockets to go through successful accept()/disconnect()/connect() and makes return error code consistent for failing both passive and active sockets. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/290 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-14mptcp: change the mpc check helper to return a skPaolo Abeni1-25/+15
After the previous patch the __mptcp_nmpc_socket helper is used only to ensure that the MPTCP socket is a suitable status - that is, the mptcp capable handshake is not started yet. Change the return value to the relevant subflow sock, to finally remove the last references to first subflow socket in the MPTCP stack. As a bonus, we can get rid of a few local variables in different functions. No functional change intended. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-14mptcp: avoid unneeded indirection in mptcp_stream_accept()Paolo Abeni1-19/+10
We are going to remove the first subflow socket soon, so avoid the additional indirection at accept() time. Instead access directly the first subflow sock, and update mptcp_accept() to operate on it. This allows dropping a duplicated check in mptcp_accept(). No functional changes intended. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-14mptcp: avoid additional indirection in mptcp_poll()Paolo Abeni1-3/+3
We are going to remove the first subflow socket soon, so avoid the additional indirection at poll() time. Instead access directly the first subflow sock. No functional changes intended. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-14mptcp: avoid additional indirection in mptcp_listen()Paolo Abeni1-4/+9
We are going to remove the first subflow socket soon, so avoid the additional indirection via at listen() time. Instead call directly the recently introduced helper on the first subflow sock. No functional changes intended. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-14mptcp: mptcp: avoid additional indirection in mptcp_bind()Paolo Abeni1-5/+12
We are going to remove the first subflow socket soon, so avoid the additional indirection via at bind() time. Instead call directly the recently introduced helpers on the first subflow sock. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-14mptcp: avoid subflow socket usage in mptcp_get_port()Paolo Abeni1-5/+3
We are going to remove the first subflow socket soon, so avoid accessing it in mptcp_get_port(). Instead, access directly the first subflow sock. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-14mptcp: avoid additional __inet_stream_connect() callPaolo Abeni1-16/+33
The mptcp protocol maintains an additional socket just to easily invoke a few stream operations on the first subflow. One of them is __inet_stream_connect(). We are going to remove the first subflow socket soon, so avoid the additional indirection via at connect time, calling directly into the sock-level connect() ops. The sk-level connect never return -EINPROGRESS, cleanup the error path accordingly. Additionally, the ssk status on error is always TCP_CLOSE. Avoid unneeded access to the subflow sk state. No functional change intended. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-14mptcp: avoid unneeded mptcp_token_destroy() callsPaolo Abeni1-2/+2
The MPTCP protocol currently clears the msk token both at connect() and listen() time. That is needed to deal with failing connect() calls that can create a new token while leaving the sk in TCP_CLOSE,SS_UNCONNECTED status and thus allowing later connect() and/or listen() calls. Let's deal with such failures explicitly, cleaning the token in a timely manner and avoid the confusing early mptcp_token_destroy(). Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-2/+2
Cross-merge networking fixes after downstream PR. No conflicts. Adjacent changes: drivers/net/ethernet/intel/igc/igc_main.c 06b412589eef ("igc: Add lock to safeguard global Qbv variables") d3750076d464 ("igc: Add TransmissionOverrun counter") drivers/net/ethernet/microsoft/mana/mana_en.c a7dfeda6fdec ("net: mana: Fix MANA VF unload when hardware is unresponsive") a9ca9f9ceff3 ("page_pool: split types and declarations from page_pool.h") 92272ec4107e ("eth: add missing xdp.h includes in drivers") net/mptcp/protocol.h 511b90e39250 ("mptcp: fix disconnect vs accept race") b8dc6d6ce931 ("mptcp: fix rcv buffer auto-tuning") tools/testing/selftests/net/mptcp/mptcp_join.sh c8c101ae390a ("selftests: mptcp: join: fix 'implicit EP' test") 03668c65d153 ("selftests: mptcp: join: rework detailed report") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-10net: annotate data-races around sock->opsEric Dumazet1-4/+4
IPV6_ADDRFORM socket option is evil, because it can change sock->ops while other threads might read it. Same issue for sk->sk_family being set to AF_INET. Adding READ_ONCE() over sock->ops reads is needed for sockets that might be impacted by IPV6_ADDRFORM. Note that mptcp_is_tcpsk() can also overwrite sock->ops. Adding annotations for all sk->sk_family reads will require more patches :/ BUG: KCSAN: data-race in ____sys_sendmsg / do_ipv6_setsockopt write to 0xffff888109f24ca0 of 8 bytes by task 4470 on cpu 0: do_ipv6_setsockopt+0x2c5e/0x2ce0 net/ipv6/ipv6_sockglue.c:491 ipv6_setsockopt+0x57/0x130 net/ipv6/ipv6_sockglue.c:1012 udpv6_setsockopt+0x95/0xa0 net/ipv6/udp.c:1690 sock_common_setsockopt+0x61/0x70 net/core/sock.c:3663 __sys_setsockopt+0x1c3/0x230 net/socket.c:2273 __do_sys_setsockopt net/socket.c:2284 [inline] __se_sys_setsockopt net/socket.c:2281 [inline] __x64_sys_setsockopt+0x66/0x80 net/socket.c:2281 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff888109f24ca0 of 8 bytes by task 4469 on cpu 1: sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0x349/0x4c0 net/socket.c:2503 ___sys_sendmsg net/socket.c:2557 [inline] __sys_sendmmsg+0x263/0x500 net/socket.c:2643 __do_sys_sendmmsg net/socket.c:2672 [inline] __se_sys_sendmmsg net/socket.c:2669 [inline] __x64_sys_sendmmsg+0x57/0x60 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0xffffffff850e32b8 -> 0xffffffff850da890 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 4469 Comm: syz-executor.1 Not tainted 6.4.0-rc5-syzkaller-00313-g4c605260bc60 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20230808135809.2300241-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-05mptcp: avoid bogus reset on fallback closePaolo Abeni1-1/+1
Since the blamed commit, the MPTCP protocol unconditionally sends TCP resets on all the subflows on disconnect(). That fits full-blown MPTCP sockets - to implement the fastclose mechanism - but causes unexpected corruption of the data stream, caught as sporadic self-tests failures. Fixes: d21f83485518 ("mptcp: use fastclose on more edge scenarios") Cc: stable@vger.kernel.org Tested-by: Matthieu Baerts <matthieu.baerts@tessares.net> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/419 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Link: https://lore.kernel.org/r/20230803-upstream-net-20230803-misc-fixes-6-5-v1-3-6671b1ab11cc@tessares.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-05mptcp: fix the incorrect judgment for msk->cb_flagsXiang Yang1-1/+1
Coccicheck reports the error below: net/mptcp/protocol.c:3330:15-28: ERROR: test of a variable/field address Since the address of msk->cb_flags is used in __test_and_clear_bit, the address should not be NULL. The judgment for if (unlikely(msk->cb_flags)) will always be true, we should check the real value of msk->cb_flags here. Fixes: 65a569b03ca8 ("mptcp: optimize release_cb for the common case") Signed-off-by: Xiang Yang <xiangyang3@huawei.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Link: https://lore.kernel.org/r/20230803072438.1847500-1-xiangyang3@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-2/+1
Cross-merge networking fixes after downstream PR. No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-27mptcp: more accurate NL event generationPaolo Abeni1-2/+1
Currently the mptcp code generate a "new listener" event even if the actual listen() syscall fails. Address the issue moving the event generation call under the successful branch. Cc: stable@vger.kernel.org Fixes: f8c9dfbd875b ("mptcp: add pm listener events") Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20230725-send-net-20230725-v1-2-6f60fe7137a9@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-25mptcp: fix rcv buffer auto-tuningPaolo Abeni1-8/+7
The MPTCP code uses the assumption that the tcp_win_from_space() helper does not use any TCP-specific field, and thus works correctly operating on an MPTCP socket. The commit dfa2f0483360 ("tcp: get rid of sysctl_tcp_adv_win_scale") broke such assumption, and as a consequence most MPTCP connections stall on zero-window event due to auto-tuning changing the rcv buffer size quite randomly. Address the issue syncing again the MPTCP auto-tuning code with the TCP one. To achieve that, factor out the windows size logic in socket independent helpers, and reuse them in mptcp_rcv_space_adjust(). The MPTCP level scaling_ratio is selected as the minimum one from the all the subflows, as a worst-case estimate. Fixes: dfa2f0483360 ("tcp: get rid of sysctl_tcp_adv_win_scale") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Link: https://lore.kernel.org/r/20230720-upstream-net-next-20230720-mptcp-fix-rcv-buffer-auto-tuning-v1-1-175ef12b8380@tessares.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-24ipv6: remove hard coded limitation on ipv6_pinfoEric Dumazet1-0/+1
IPv6 inet sockets are supposed to have a "struct ipv6_pinfo" field at the end of their definition, so that inet6_sk_generic() can derive from socket size the offset of the "struct ipv6_pinfo". This is very fragile, and prevents adding bigger alignment in sockets, because inet6_sk_generic() does not work if the compiler adds padding after the ipv6_pinfo component. We are currently working on a patch series to reorganize TCP structures for better data locality and found issues similar to the one fixed in commit f5d547676ca0 ("tcp: fix tcp_inet6_sk() for 32bit kernels") Alternative would be to force an alignment on "struct ipv6_pinfo", greater or equal to __alignof__(any ipv6 sock) to ensure there is no padding. This does not look great. v2: fix typo in mptcp_proto_v6_init() (Paolo) Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Chao Wu <wwchao@google.com> Cc: Wei Wang <weiwan@google.com> Cc: Coco Li <lixiaoyan@google.com> Cc: YiFei Zhu <zhuyifei@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-05mptcp: do not rely on implicit state check in mptcp_listen()Paolo Abeni1-0/+5
Since the blamed commit, closing the first subflow resets the first subflow socket state to SS_UNCONNECTED. The current mptcp listen implementation relies only on such state to prevent touching not-fully-disconnected sockets. Incoming mptcp fastclose (or paired endpoint removal) unconditionally closes the first subflow. All the above allows an incoming fastclose followed by a listen() call to successfully race with a blocking recvmsg(), potentially causing the latter to hit a divide by zero bug in cleanup_rbuf/__tcp_select_window(). Address the issue explicitly checking the msk socket state in mptcp_listen(). An alternative solution would be moving the first subflow socket state update into mptcp_disconnect(), but in the long term the first subflow socket should be removed: better avoid relaying on it for internal consistency check. Fixes: b29fcfb54cd7 ("mptcp: full disconnect implementation") Cc: stable@vger.kernel.org Reported-by: Christoph Paasch <cpaasch@apple.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/414 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-05mptcp: ensure subflow is unhashed before cleaning the backlogPaolo Abeni1-1/+1
While tacking care of the mptcp-level listener I unintentionally moved the subflow level unhash after the subflow listener backlog cleanup. That could cause some nasty race and makes the code harder to read. Address the issue restoring the proper order of operations. Fixes: 57fc0f1ceaa4 ("mptcp: ensure listener is unhashed before updating the sk status") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-25sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)David Howells1-2/+0
Remove ->sendpage() and ->sendpage_locked(). sendmsg() with MSG_SPLICE_PAGES should be used instead. This allows multiple pages and multipage folios to be passed through. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for net/can cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> cc: linux-afs@lists.infradead.org cc: mptcp@lists.linux.dev cc: rds-devel@oss.oracle.com cc: tipc-discussion@lists.sourceforge.net cc: virtualization@lists.linux-foundation.org Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-96/+64
Cross-merge networking fixes after downstream PR. Conflicts: tools/testing/selftests/net/fcnal-test.sh d7a2fc1437f7 ("selftests: net: fcnal-test: check if FIPS mode is enabled") dd017c72dde6 ("selftests: fcnal: Test SO_DONTROUTE on TCP sockets.") https://lore.kernel.org/all/5007b52c-dd16-dbf6-8d64-b9701bfa498b@tessares.net/ https://lore.kernel.org/all/20230619105427.4a0df9b3@canb.auug.org.au/ No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-22mptcp: consolidate transition to TCP_CLOSE in mptcp_do_fastclose()Paolo Abeni1-5/+3
The MPTCP code always set the msk state to TCP_CLOSE before calling performing the fast-close. Move such state transition in mptcp_do_fastclose() to avoid some code duplication. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-22mptcp: add subflow unique idPaolo Abeni1-0/+6
The user-space need to properly account the data received/sent by individual subflows. When additional subflows are created and/or closed during the MPTCP socket lifetime, the information currently exposed via MPTCP_TCPINFO are not enough: subflows are identified only by the sequential position inside the info dumps, and that will change with the above mentioned events. To solve the above problem, this patch introduces a new subflow identifier that is unique inside the given MPTCP socket scope. The initial subflow get the id 1 and the other subflows get incremental values at join time. Link: https://github.com/multipath-tcp/mptcp_net-next/issues/388 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-22mptcp: track some aggregate data countersPaolo Abeni1-1/+10
Currently there are no data transfer counters accounting for all the subflows used by a given MPTCP socket. The user-space can compute such figures aggregating the subflow info, but that is inaccurate if any subflow is closed before the MPTCP socket itself. Add the new counters in the MPTCP socket itself and expose them via the existing diag and sockopt. While touching mptcp_diag_fill_info(), acquire the relevant locks before fetching the msk data, to ensure better data consistency Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/385 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-22mptcp: move snd_una update earlier for fallback socketPaolo Abeni1-6/+0
That will avoid an unneeded conditional in both the fast-path and in the fallback case and will simplify a bit the next patch. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-22mptcp: ensure listener is unhashed before updating the sk statusPaolo Abeni1-12/+19
The MPTCP protocol access the listener subflow in a lockless manner in a couple of places (poll, diag). That works only if the msk itself leaves the listener status only after that the subflow itself has been closed/disconnected. Otherwise we risk deadlock in diag, as reported by Christoph. Address the issue ensuring that the first subflow (the listener one) is always disconnected before updating the msk socket status. Reported-by: Christoph Paasch <cpaasch@apple.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/407 Fixes: b29fcfb54cd7 ("mptcp: full disconnect implementation") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-22mptcp: drop legacy code around RX EOFPaolo Abeni1-49/+0
Thanks to the previous patch -- "mptcp: consolidate fallback and non fallback state machine" -- we can finally drop the "temporary hack" used to detect rx eof. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-22mptcp: consolidate fallback and non fallback state machinePaolo Abeni1-26/+15
An orphaned msk releases the used resources via the worker, when the latter first see the msk in CLOSED status. If the msk status transitions to TCP_CLOSE in the release callback invoked by the worker's final release_sock(), such instance of the workqueue will not take any action. Additionally the MPTCP code prevents scheduling the worker once the socket reaches the CLOSE status: such msk resources will be leaked. The only code path that can trigger the above scenario is the __mptcp_check_send_data_fin() in fallback mode. Address the issue removing the special handling of fallback socket in __mptcp_check_send_data_fin(), consolidating the state machine for fallback and non fallback socket. Since non-fallback sockets do not send and do not receive data_fin, the mptcp code can update the msk internal status to match the next step in the SM every time data fin (ack) should be generated or received. As a consequence we can remove a bunch of checks for fallback from the fastpath. Fixes: 6e628cd3a8f7 ("mptcp: use mptcp release_cb for delayed tasks") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>