Send logic caches last active subflow in the msk, so it needs to be
cleared when the cached subflow is closed.
Fixes: d5f49190de ("mptcp: allow picking different xmit subflows")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/155
Reported-by: Christoph Paasch <cpaasch@apple.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
mptcp re-used inet(6)_release, so the subflow sockets are ignored.
Need to invoke ip(v6)_mc_drop_socket function to ensure mcast join
resources get free'd.
Fixes: 717e79c867 ("mptcp: Add setsockopt()/getsockopt() socket operations")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/110
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently we move orphaned msk sockets directly from FIN_WAIT2
state to CLOSE, with the rationale that incoming additional
data could be just dropped by the TCP stack/TW sockets.
Anyhow we miss sending MPTCP-level ack on incoming DATA_FIN,
and that may hang the peers.
Fixes: e16163b6e2 ("mptcp: refactor shutdown and close")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Allow userspace (mptcpd) to subscribe to mptcp genl multicast events.
This implementation reuses the same event API as the mptcp kernel fork
to ease integration of existing tools, e.g. mptcpd.
Supported events include:
1. start and close of an mptcp connection
2. start and close of subflows (joins)
3. announce and withdrawals of addresses
4. subflow priority (backup/non-backup) change.
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Once event support is added this may need to allocate memory while msk
lock is held with softirqs disabled.
Not using lock_fast also allows to do the allocation with GFP_KERNEL.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass the first/initial subflow to the existing functions so they can
pass this on to the notification handler that is added later in the
series.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In case mptcp socket is already dead the entire mptcp socket
will be freed. We can avoid the close check in this case.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When remote side closes a subflow we should schedule the worker to
dispose of the subflow in a timely manner.
Otherwise, SF_CLOSED event won't be generated until the mptcp
socket itself is closing or local side is closing another subflow.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Prepare for subflow close events:
When mptcp connection is torn down its enough to send the mptcp socket
close notification rather than a subflow close event for all of the
subflows followed by the mptcp close event.
This splits the helper: mptcp_close_ssk() will emit the close
notification, __mptcp_close_ssk will not.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allows to make some functions static and avoids acquire of the pm
spinlock in protocol.c.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently we do not schedule the MPTCP retransmission
timer after pushing the data when such action happens
in the subflow context.
This may cause hang-up on active-backup scenarios, or
even when only single subflow msks are involved, if we lost
some peer's ack.
Fixes: 6e628cd3a8 ("mptcp: use mptcp release_cb for delayed tasks")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move mptcp_cleanup_rbuf() related checks inside the mentioned
helper and extend them to mirror TCP checks more closely.
Additionally drop the 'rmem_pending' hack, since commit 879526030c
("mptcp: protect the rx path with the msk socket spinlock") we
can use instead 'rmem_released'.
Fixes: ea4ca586b1 ("mptcp: refine MPTCP-level ack scheduling")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Syzkaller was able to trigger the following splat again:
WARNING: CPU: 1 PID: 12512 at net/mptcp/protocol.c:761 mptcp_reset_timer+0x12a/0x160 net/mptcp/protocol.c:761
Modules linked in:
CPU: 1 PID: 12512 Comm: kworker/1:6 Not tainted 5.10.0-rc6 #52
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:mptcp_reset_timer+0x12a/0x160 net/mptcp/protocol.c:761
Code: e8 4b 0c ad ff e8 56 21 88 fe 48 b8 00 00 00 00 00 fc ff df 48 c7 04 03 00 00 00 00 48 83 c4 40 5b 5d 41 5c c3 e8 36 21 88 fe <0f> 0b 41 bc c8 00 00 00 eb 98 e8 e7 b1 af fe e9 30 ff ff ff 48 c7
RSP: 0018:ffffc900018c7c68 EFLAGS: 00010293
RAX: ffff888108cb1c80 RBX: 1ffff92000318f8d RCX: ffffffff82ad0307
RDX: 0000000000000000 RSI: ffffffff82ad036a RDI: 0000000000000007
RBP: ffff888113e2d000 R08: ffff888108cb1c80 R09: ffffed10227c5ab7
R10: ffff888113e2d5b7 R11: ffffed10227c5ab6 R12: 0000000000000000
R13: ffff88801f100000 R14: ffff888113e2d5b0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88811b500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd76a874ef8 CR3: 000000001689c005 CR4: 0000000000170ee0
Call Trace:
mptcp_worker+0xaa4/0x1560 net/mptcp/protocol.c:2334
process_one_work+0x8d3/0x1200 kernel/workqueue.c:2272
worker_thread+0x9c/0x1090 kernel/workqueue.c:2418
kthread+0x303/0x410 kernel/kthread.c:292
ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:296
The mptcp_worker tries to update the MPTCP retransmission timer
even if such timer is not currently scheduled.
The mptcp_rtx_head() return value is bogus: we can have enqueued
data not yet transmitted. The above may additionally cause spurious,
unneeded MPTCP-level retransmissions.
Fix the issue adding an explicit clearing of the rtx queue before
trying to retransmit and checking for unacked data.
Additionally drop an unneeded timer stop call and the unused
mptcp_rtx_tail() helper.
Reported-by: Christoph Paasch <cpaasch@apple.com>
Fixes: 6e628cd3a8 ("mptcp: use mptcp release_cb for delayed tasks")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current mptcp_poll() implementation gives unexpected
results after shutdown(SEND_SHUTDOWN) and when the msk
status is TCP_CLOSE.
Set the correct mask.
Fixes: 8edf08649e ("mptcp: rework poll+nospace handling")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently all errors received on msk subflows are ignored.
We need to catch at least the errors on connect() and
on fallback sockets.
Use a custom sk_error_report callback at subflow level,
and do the real action under the msk socket lock - via
the usual sock_owned_by_user()/release_callback() schema.
Fixes: 6e628cd3a8 ("mptcp: use mptcp release_cb for delayed tasks")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a few assertions to make sure functions are called with the needed
locks held.
Two functions gain might_sleep annotations because they contain
conditional calls to functions that sleep.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch creates a listening socket when an address with a port-number
is added by PM netlink. Then binds the new port to the socket, and
listens for new connections.
When the address is removed or the addresses are flushed by PM netlink,
release the listening socket.
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
On MPTCP-level ack reception, the packet scheduler
may select a subflow other then the current one.
Prior to this commit we rely on the workqueue to trigger
action on such subflow.
This changeset introduces an infrastructure that allows
any MPTCP subflow to schedule actions (MPTCP xmit) on
others subflows without resorting to (multiple) process
reschedule.
A dummy NAPI instance is used instead. When MPTCP needs to
trigger action an a different subflow, it enqueues the target
subflow on the NAPI backlog and schedule such instance as needed.
The dummy NAPI poll method walks the sockets backlog and tries
to acquire the (BH) socket lock on each of them. If the socket
is owned by the user space, the action will be completed by
the sock release cb, otherwise push is started.
This change leverages the delegated action infrastructure
to avoid invoking the MPTCP worker to spool the pending data,
when the packet scheduler picks a subflow other then the one
currently processing the incoming MPTCP-level ack.
Additionally we further refine the subflow selection
invoking the packet scheduler for each chunk of data
even inside __mptcp_subflow_push_pending().
v1 -> v2:
- fix possible UaF at shutdown time, resetting sock ops
after removing the ulp context
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Otherwise the packet scheduler policy will not be
enforced when pushing pending data at MPTCP-level
ack reception time.
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The current packet scheduler can enqueue up to sndbuf
data on each subflow. If the send buffer is large and
the subflows are not symmetric, this could lead to
suboptimal aggregate bandwidth utilization.
Limit the amount of queued data to the maximum send
window.
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
After commit 6e628cd3a8 ("mptcp: use mptcp release_cb for
delayed tasks"), MPTCP never sets the flag bit SOCK_NOSPACE
on its subflow. As a side effect, autotune never takes place,
as it happens inside tcp_new_space(), which in turn is called
only when the mentioned bit is set.
Let's sendmsg() set the subflows NOSPACE bit when looking for
more memory and use the subflow write_space callback to propagate
the snd buf update and wake-up the user-space.
Additionally, this allows dropping a bunch of duplicate code and
makes the SNDBUF_LIMITED chrono relevant again for MPTCP subflows.
Fixes: 6e628cd3a8 ("mptcp: use mptcp release_cb for delayed tasks")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, incoming subflows link to the parent socket,
while outgoing ones link to a per subflow socket. The latter
is not really needed, except at the initial connect() time and
for the first subflow.
Always graft the outgoing subflow to the parent socket and
free the unneeded ones early.
This allows some code cleanup, reduces the amount of memory
used and will simplify the next patch
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tcp_disconnect() expects the caller acquires the sock lock,
but mptcp_disconnect() is not doing that. Add the missing
required lock.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: 76e2a55d16 ("mptcp: better msk-level shutdown.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/f818e82b58a556feeb71dcccc8bf1c87aafc6175.1610638176.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Instead of re-implementing most of inet_shutdown, re-use
such helper, and implement the MPTCP-specific bits at the
'proto' level.
The msk-level disconnect() can now be invoked, lets provide a
suitable implementation.
As a side effect, this fixes bad state management for listener
sockets. The latter could lead to division by 0 oops since
commit ea4ca586b1 ("mptcp: refine MPTCP-level ack scheduling").
Fixes: 43b54c6ee3 ("mptcp: Use full MPTCP-level disconnect state machine")
Fixes: ea4ca586b1 ("mptcp: refine MPTCP-level ack scheduling")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Syzkaller found a way to trigger division by zero
in mptcp_subflow_cleanup_rbuf().
The current checks implemented into tcp_can_send_ack()
are too week, let's be more accurate.
Reported-by: Christoph Paasch <cpaasch@apple.com>
Fixes: ea4ca586b1 ("mptcp: refine MPTCP-level ack scheduling")
Fixes: fd8976790a ("mptcp: be careful on MPTCP-level ack.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When sendmsg() needs to wait for memory, the pending data
is not updated. That causes a drift in forward memory allocation,
leading to stall and/or warnings at socket close time.
This change addresses the above issue moving the pending data
counter update inside the sendmsg() main loop.
Fixes: 6e628cd3a8 ("mptcp: use mptcp release_cb for delayed tasks")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When multiple subflows are active, we can receive a
window update on subflow with no write space available.
MPTCP will try to push frames on such subflow and will
fail. Pending frames will be pushed only after receiving
a window update on a subflow with some wspace available.
Overall the above could lead to suboptimal aggregate
bandwidth usage.
Instead, we should try to push pending frames as soon as
the subflow reaches both conditions mentioned above.
We can finally enable self-tests with asymmetric links,
as the above makes them finally pass.
Fixes: 6f8a612a33 ("mptcp: keep track of advertised windows right edge")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
MPTCP closes the subflows while holding the msk-level lock.
While acquiring the subflow socket lock we need to use the
correct nested annotation, or we can hit a lockdep splat
at runtime.
Reported-and-tested-by: Geliang Tang <geliangtang@gmail.com>
Fixes: e16163b6e2 ("mptcp: refactor shutdown and close")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently MPTCP is not propagating the security context
from the ingress request socket to newly created msk
at clone time.
Address the issue invoking the missing security helper.
Fixes: cf7da0d66c ("mptcp: Create SUBFLOW socket for incoming connections")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently the xmit path of the MPTCP protocol creates smaller-
than-max-size skbs, which is suboptimal for the performances.
There are a few things to improve:
- when coalescing to an existing skb, must clear the PUSH flag
- tcp_build_frag() expect the available space as an argument.
When coalescing is enable MPTCP already subtracted the
to-be-coalesced skb len. We must increment said argument
accordingly.
Before:
./use_mptcp.sh netperf -H 127.0.0.1 -t TCP_STREAM
[...]
131072 16384 16384 30.00 24414.86
After:
./use_mptcp.sh netperf -H 127.0.0.1 -t TCP_STREAM
[...]
131072 16384 16384 30.05 28357.69
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>
parse the MPTCP FASTCLOSE subtype.
If provided key matches the local one, schedule the work queue to close
(with tcp reset) all subflows.
The MPTCP socket moves to closed state immediately.
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When the workqueue disposes of the msk, the subflows can still
receive some data from the peer after __mptcp_close_ssk()
completes.
The above could trigger a race between the msk receive path and the
msk destruction. Acquiring the mptcp_data_lock() in __mptcp_destroy_sock()
will not save the day: the rx path could be reached even after msk
destruction completes.
Instead use the subflow 'disposable' flag to prevent entering
the msk receive path after __mptcp_close_ssk().
Fixes: e16163b6e2 ("mptcp: refactor shutdown and close")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Christoph reported the following splat:
WARNING: CPU: 0 PID: 4615 at net/ipv4/inet_connection_sock.c:1031 inet_csk_listen_stop+0x8e8/0xad0 net/ipv4/inet_connection_sock.c:1031
Modules linked in:
CPU: 0 PID: 4615 Comm: syz-executor.4 Not tainted 5.9.0 #37
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:inet_csk_listen_stop+0x8e8/0xad0 net/ipv4/inet_connection_sock.c:1031
Code: 03 00 00 00 e8 79 b2 3d ff e9 ad f9 ff ff e8 1f 76 ba fe be 02 00 00 00 4c 89 f7 e8 62 b2 3d ff e9 14 f9 ff ff e8 08 76 ba fe <0f> 0b e9 97 f8 ff ff e8 fc 75 ba fe be 03 00 00 00 4c 89 f7 e8 3f
RSP: 0018:ffffc900037f7948 EFLAGS: 00010293
RAX: ffff88810a349c80 RBX: ffff888114ee1b00 RCX: ffffffff827b14cd
RDX: 0000000000000000 RSI: ffffffff827b1c38 RDI: 0000000000000005
RBP: ffff88810a2a8000 R08: ffff88810a349c80 R09: fffff520006fef1f
R10: 0000000000000003 R11: fffff520006fef1e R12: ffff888114ee2d00
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff888114ee1d68
FS: 00007f2ac1945700(0000) GS:ffff88811b400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd44798bc0 CR3: 0000000109810002 CR4: 0000000000170ef0
Call Trace:
__tcp_close+0xd86/0x1110 net/ipv4/tcp.c:2433
__mptcp_close_ssk+0x256/0x430 net/mptcp/protocol.c:1761
__mptcp_destroy_sock+0x49b/0x770 net/mptcp/protocol.c:2127
mptcp_close+0x62d/0x910 net/mptcp/protocol.c:2184
inet_release+0xe9/0x1f0 net/ipv4/af_inet.c:434
__sock_release+0xd2/0x280 net/socket.c:596
sock_close+0x15/0x20 net/socket.c:1277
__fput+0x276/0x960 fs/file_table.c:281
task_work_run+0x109/0x1d0 kernel/task_work.c:151
get_signal+0xe8f/0x1d40 kernel/signal.c:2561
arch_do_signal+0x88/0x1b60 arch/x86/kernel/signal.c:811
exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
exit_to_user_mode_prepare+0x9b/0xf0 kernel/entry/common.c:191
syscall_exit_to_user_mode+0x22/0x150 kernel/entry/common.c:266
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f2ac1254469
Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ff 49 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007f2ac1944dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffbf RBX: 000000000069bf00 RCX: 00007f2ac1254469
RDX: 0000000000000000 RSI: 0000000000008982 RDI: 0000000000000003
RBP: 000000000069bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000069bf0c
R13: 00007ffeb53f178f R14: 00000000004668b0 R15: 0000000000000003
After commit 0397c6d85f ("mptcp: keep unaccepted MPC subflow into
join list"), the msk's workqueue and/or PM can touch the MPC
subflow - and acquire its socket lock - even if it's still unaccepted.
If the above event races with the relevant listener socket close, we
can end-up with the above splat.
This change addresses the issue delaying the MPC socket insertion
in conn_list at accept time - that is, partially reverting the
blamed commit.
We must additionally ensure that mptcp_pm_fully_established()
happens after accept() time, or the PM will not be able to
handle properly such event - conn_list could be empty otherwise.
In the receive path, we check the subflow list node to ensure
it is out of the listener queue. Be sure client subflows do
not match transiently such condition moving them into the join
list earlier at creation time.
Since we now have multiple mptcp_pm_fully_established() call sites
from different code-paths, said helper can now race with itself.
Use an additional PM status bit to avoid multiple notifications.
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/103
Fixes: 0397c6d85f ("mptcp: keep unaccepted MPC subflow into join list"),
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a packet is ready in receive queue, and application isssues
a recvmsg()/recvfrom()/recvmmsg() request asking for zero bytes,
we hang in mptcp_recvmsg().
Fixes: ea4ca586b1 ("mptcp: refine MPTCP-level ack scheduling")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Link: https://lore.kernel.org/r/20201202171657.1185108-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We have some tasks triggered by the subflow receive path
which require to access the msk socket status, specifically:
mptcp_clean_una() and mptcp_push_pending()
We have almost everything in place to defer to the msk
release_cb such tasks when the msk sock is owned.
Since the worker is no more used to clean the acked data,
for fallback sockets we need to explicitly flush them.
As an added bonus we can move the wake-up code in __mptcp_clean_una(),
simplify a lot mptcp_poll() and move the timer update under
the data lock.
The worker is now used only to process and send DATA_FIN
packets and do the mptcp-level retransmissions.
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Extending the data_lock scope in mptcp_incoming_option
we can use that to protect both snd_una and wnd_end.
In the typical case, we will have a single atomic op instead of 2
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move the TX skbs allocation in mptcp_sendmsg() scope,
and tentatively pre-allocate a skbs number proportional
to the sendmsg() length.
Use the ssk tx skb cache to prevent the subflow allocation.
This allows removing the msk skb extension cache and will
make possible the later patches.
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Such spinlock is currently used only to protect the 'owned'
flag inside the socket lock itself. With this patch, we extend
its scope to protect the whole msk receive path and
sk_forward_memory.
Given the above, we can always move data into the msk receive
queue (and OoO queue) from the subflow.
We leverage the previous commit, so that we need to acquire the
spinlock in the tx path only when moving fwd memory.
recvmsg() must now explicitly acquire the socket spinlock
when moving skbs out of sk_receive_queue. To reduce the number of
lock operations required we use a second rx queue and splice the
first into the latter in mptcp_lock_sock(). Additionally rmem
allocated memory is bulk-freed via release_cb()
Acked-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This leverages the previous commit to reserve the wmem
required for the sendmsg() operation when the msk socket
lock is first acquired.
Some heuristics are used to get a reasonable [over] estimation of
the whole memory required. If we can't forward alloc such amount
fallback to a reasonable small chunk, otherwise enter the wait
for memory path.
When sendmsg() needs more memory it looks at wmem_reserved
first and if that is exhausted, move more space from
sk_forward_alloc.
The reserved memory is not persistent and is released at the
next socket unlock via the release_cb().
Overall this will simplify the next patch.
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We can enter the main mptcp_recvmsg() loop even when
no subflows are connected. As note by Eric, that would
result in a divide by zero oops on ack generation.
Address the issue by checking the subflow status before
sending the ack.
Additionally protect mptcp_recvmsg() against invocation
with weird socket states.
v1 -> v2:
- removed unneeded inline keyword - Jakub
Reported-and-suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: ea4ca586b1 ("mptcp: refine MPTCP-level ack scheduling")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/5370c0ae03449239e3d1674ddcfb090cf6f20abe.1606253206.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
On close this timer might be scheduled. mptcp uses sk_reset_timer for
this, so the a reference on the mptcp socket is taken.
This causes a refcount leak which can for example be reproduced
with 'mp_join_server_v4.pkt' from the mptcp-packetdrill repo.
The leak has nothing to do with join requests, v1_mp_capable_bind_no_cs.pkt
works too when replacing the last ack mpcapable to v1 instead of v0.
unreferenced object 0xffff888109bba040 (size 2744):
comm "packetdrill", [..]
backtrace:
[..] sk_prot_alloc.isra.0+0x2b/0xc0
[..] sk_clone_lock+0x2f/0x740
[..] mptcp_sk_clone+0x33/0x1a0
[..] subflow_syn_recv_sock+0x2b1/0x690 [..]
Fixes: e16163b6e2 ("mptcp: refactor shutdown and close")
Cc: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20201124162446.11448-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Send timely MPTCP-level ack is somewhat difficult when
the insertion into the msk receive level is performed
by the worker.
It needs TCP-level dup-ack to notify the MPTCP-level
ack_seq increase, as both the TCP-level ack seq and the
rcv window are unchanged.
We can actually avoid processing incoming data with the
worker, and let the subflow or recevmsg() send ack as needed.
When recvmsg() moves the skbs inside the msk receive queue,
the msk space is still unchanged, so tcp_cleanup_rbuf() could
end-up skipping TCP-level ack generation. Anyway, when
__mptcp_move_skbs() is invoked, a known amount of bytes is
going to be consumed soon: we update rcv wnd computation taking
them in account.
Additionally we need to explicitly trigger tcp_cleanup_rbuf()
when recvmsg() consumes a significant amount of the receive buffer.
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>
OoO handling attempts to detect when packet is out-of-window by testing
current ack sequence and remaining space vs. sequence number.
This doesn't work reliably. Store the highest allowed sequence number
that we've announced and use it to detect oow packets.
Do this when mptcp options get written to the packet (wire format).
For this to work we need to move the write_options call until after
stack selected a new tcp window.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When ADD_ADDR suboption includes an IPv6 address, the size is 28 octets.
It will not fit when other MPTCP suboptions are included in this packet,
e.g. DSS. So here we send out an ADD_ADDR dedicated packet to carry only
ADD_ADDR suboption, no other MPTCP suboptions.
In mptcp_pm_announce_addr, we check whether this is an IPv6 ADD_ADDR.
If it is, we set the flag MPTCP_ADD_ADDR_IPV6 to true. Then we call
mptcp_pm_nl_add_addr_send_ack to sent out a new pure ACK packet.
In mptcp_established_options_add_addr, we check whether this is a pure
ACK packet for ADD_ADDR. If it is, we drop all other MPTCP suboptions
in this packet, only put ADD_ADDR suboption in it.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This will simplify all operation dealing with subflows
before accept time (e.g. data fin processing, add_addr).
The join list is already flushed by mptcp_stream_accept()
before returning the newly created msk to the user space.
This also fixes an potential bug present into the old code:
conn_list was manipulated without helding the msk lock
in mptcp_stream_accept().
Tested-by: Geliang Tang <geliangtang@gmail.com>
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>
In case a subflow path is blocked, MPTCP-level retransmit may not take
place anymore because such subflow is likely to have unacked data left
in its write queue.
Ignore subflows that have experienced loss and test next candidate.
Fixes: 3b1d6210a9 ("mptcp: implement and use MPTCP-level retransmission")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We need to cope with some more state transition for
fallback sockets, or could still end-up moving to TCP_CLOSE
too early and avoid spooling some pending data
Fixes: e16163b6e2 ("mptcp: refactor shutdown and close")
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>
Only mptcp_close() can actually cancel the workqueue,
no need to add and use this flag.
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
We must start the retransmission timer only there are
pending data in the rtx queue.
Otherwise we can hit a WARN_ON in mptcp_reset_timer(),
as syzbot demonstrated.
Reported-and-tested-by: syzbot+42aa53dafb66a07e5a24@syzkaller.appspotmail.com
Fixes: d9ca1de8c0 ("mptcp: move page frag allocation in mptcp_sendmsg()")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lore.kernel.org/r/1a72039f112cae048c44d398ffa14e0a1432db3d.1605737083.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When the worker moves some bytes from the OoO queue into
the receive queue, the msk->ask_seq is updated, the MPTCP-level
ack carrying that value needs to wait the next ingress packet,
possibly slowing down or hanging the peer
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Before sending 'x' new bytes also check that the new snd_una would
be within the permitted receive window.
For every ACK that also contains a DSS ack, check whether its tcp-level
receive window would advance the current mptcp window right edge and
update it if so.
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: Jakub Kicinski <kuba@kernel.org>
MPTCP maintains a status bit, MPTCP_SEND_SPACE, that is set when at
least one subflow and the mptcp socket itself are writeable.
mptcp_poll returns EPOLLOUT if the bit is set.
mptcp_sendmsg makes sure MPTCP_SEND_SPACE gets cleared when last write
has used up all subflows or the mptcp socket wmem.
This reworks nospace handling as follows:
MPTCP_SEND_SPACE is replaced with MPTCP_NOSPACE, i.e. inverted meaning.
This bit is set when the mptcp socket is not writeable.
The mptcp-level ack path schedule will then schedule the mptcp worker
to allow it to free already-acked data (and reduce wmem usage).
This will then wake userspace processes that wait for a POLLOUT event.
sendmsg will set MPTCP_NOSPACE only when it has to wait for more
wmem (blocking I/O case).
poll path will set MPTCP_NOSPACE in case the mptcp socket is
not writeable.
Normal tcp-level notification (SOCK_NOSPACE) is only enabled
in case the subflow socket has no available wmem.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
After the previous patch we may end-up with unsent data
in the write buffer. If such buffer is full, the writer
will block for unlimited time.
We need to trigger the MPTCP xmit path even for the
subflow rx path, on MPTCP snd_una updates.
Keep things simple and just schedule the work queue if
needed.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mptcp_sendmsg() is refactored so that first it copies
the data provided from user space into the send queue,
and then tries to spool the send queue via sendmsg_frag.
There a subtle change in the mptcp level collapsing on
consecutive data fragment: we now allow that only on unsent
data.
The latter don't need to deal with msghdr data anymore
and can be simplified in a relevant way.
snd_nxt and write_seq are now tracked independently.
Overall this allows some relevant cleanup and will
allow sending pending mptcp data on msk una update in
later patch.
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We must not close the subflows before all the MPTCP level
data, comprising the DATA_FIN has been acked at the MPTCP
level, otherwise we could be unable to retransmit as needed.
__mptcp_wr_shutdown() shutdown is responsible to check for the
correct status and close all subflows. Is called by the output
path after spooling any data and at shutdown/close time.
In a similar way, __mptcp_destroy_sock() is responsible to clean-up
the MPTCP level status, and is called when the msk transition
to TCP_CLOSE.
The protocol level close() does not force anymore the TCP_CLOSE
status, but orphan the msk socket and all the subflows.
Orphaned msk sockets are forciby closed after a timeout or
when all MPTCP-level data is acked.
There is a caveat about keeping the orphaned subflows around:
the TCP stack can asynchronusly call tcp_cleanup_ulp() on them via
tcp_close(). To prevent accessing freed memory on later MPTCP
level operations, the msk acquires a reference to each subflow
socket and prevent subflow_ulp_release() from releasing the
subflow context before __mptcp_destroy_sock().
The additional subflow references are released by __mptcp_done()
and the async ULP release is detected checking ULP ops. If such
field has been already cleared by the ULP release path, the
dangling context is freed directly by __mptcp_done().
Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Track the next MPTCP sequence number used on xmit,
currently always equal to write_next.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Preparation patch to track the data pending in the msk
write queue. No functional change introduced here
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The current argument list is pretty long and quite unreadable,
move many of them into a specific struct. Later patches
will add more stuff to such struct.
Additionally drop the 'timeo' argument, now unused.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
remove some of code duplications an allow preventing
rescheduling on close.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mptcp_push_pending() is called even on orphaned
msk (and orphaned subflows), if there is outstanding
data at close() time.
To cope with the above MPTCP needs to handle explicitly
the allocation failure on xmit. The newly introduced
do_tcp_sendfrag() allows that, just plug it.
We can additionally drop a couple of sanity checks,
duplicate in the TCP code.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The mptcp proto struct currently does not provide the
required limit for forward memory scheduling. Under
pressure sk_rmem_schedule() will unconditionally try
to use such field and will oops.
Address the issue inheriting the tcp limit, as we already
do for the wmem one.
Fixes: 9c3f94e168 ("mptcp: add missing memory scheduling in the rx path")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Link: https://lore.kernel.org/r/37af798bd46f402fb7c79f57ebbdd00614f5d7fa.1604861097.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mptcp_clean_una() will wake writers in case memory could be reclaimed.
When called from mptcp_sendmsg the wakeup code isn't needed.
Move the wakeup to a new helper and then use that from the mptcp worker.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When the TCP stack splits a packet on the write queue, the tail
half currently lose the associated skb extensions, and will not
carry the DSM on the wire.
The above does not cause functional problems and is allowed by
the RFC, but interact badly with GRO and RX coalescing, as possible
candidates for aggregation will carry different TCP options.
This change tries to improve the MPTCP behavior, propagating the
skb extensions on split.
Additionally, we must prevent the MPTCP stack from updating the
mapping after the split occur: that will both violate the RFC and
fool the reader.
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>
The function is short and won't sleep, so this can use the _fast version.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In addition to tcp autotuning during read, it may also increase the
receive buffer in tcp_clamp_window().
In this case, mptcp should adjust its receive buffer size as well so
it can move all pending skbs from the subflow socket to the mptcp socket.
At this time, TCP can have more skbs ready for processing than what the
mptcp receive buffer size allows.
In the mptcp case, the receive window announced is based on the free
space of the mptcp parent socket instead of the individual subflows.
Following the subflow allows mptcp to grow its receive buffer.
This is especially noticeable for loopback traffic where two skbs are
enough to fill the initial receive window.
In mptcp_data_ready() we do not hold the mptcp socket lock, so modifying
mptcp_sk->sk_rcvbuf is racy. Do it when moving skbs from subflow to
mptcp socket, both sockets are locked in this case.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When moving the skbs from the subflow into the msk receive
queue, we must schedule there the required amount of memory.
Try to borrow the required memory from the subflow, if needed,
so that we leverage the existing TCP heuristic.
Fixes: 6771bfd9ee ("mptcp: update mptcp ack sequence from work queue")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Link: https://lore.kernel.org/r/f6143a6193a083574f11b00dbf7b5ad151bc4ff4.1603810630.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Minor conflicts in net/mptcp/protocol.h and
tools/testing/selftests/net/Makefile.
In both cases code was added on both sides in the same place
so just keep both.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The msk can close MP_JOIN subflows if the initial handshake
fails. Currently such subflows are kept alive in the
conn_list until the msk itself is closed.
Beyond the wasted memory, we could end-up sending the
DATA_FIN and the DATA_FIN ack on such socket, even after a
reset.
Fixes: 43b54c6ee3 ("mptcp: Use full MPTCP-level disconnect state machine")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If recvmsg() and the workqueue race to dequeue the data
pending on some subflow, the current mapping for such
subflow covers several skbs and some of them have not
reached yet the received, either the worker or recvmsg()
can find a subflow with the data_avail flag set - since
the current mapping is valid and in sequence - but no
skbs in the receive queue - since the other entity just
processed them.
The above will lead to an unbounded loop in __mptcp_move_skbs()
and a subsequent hang of any task trying to acquiring the msk
socket lock.
This change addresses the issue stopping the __mptcp_move_skbs()
loop as soon as we detect the above race (empty receive queue
with data_avail set).
Reported-and-tested-by: syzbot+fcf8ca5817d6e92c6567@syzkaller.appspotmail.com
Fixes: ab174ad8ef ("mptcp: move ooo skbs into msk out of order queue.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently we skip calling tcp_cleanup_rbuf() when packets
are moved into the OoO queue or simply dropped. In both
cases we still increment tp->copied_seq, and we should
ask the TCP stack to check for ack.
Fixes: c76c695656 ("mptcp: call tcp_cleanup_rbuf on subflows")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rejecting non-native endian BTF overlapped with the addition
of support for it.
The rest were more simple overlapping changes, except the
renesas ravb binding update, which had to follow a file
move as well as a YAML conversion.
Signed-off-by: David S. Miller <davem@davemloft.net>
The msk->ack_seq value is sometimes read without the msk lock held, so
make proper use of READ_ONCE and WRITE_ONCE.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch added a new helper named mptcp_destroy_common containing the
shared code between mptcp_destroy() and mptcp_sock_destruct().
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implements the remove announced addr and subflow logic in PM
netlink.
When the PM netlink removes an address, we traverse all the existing msk
sockets to find the relevant sockets.
We add a new list named anno_list in mptcp_pm_data, to record all the
announced addrs. In the traversing, we check if it has been recorded.
If it has been, we trigger the RM_ADDR signal.
We also check if this address is in conn_list. If it is, we remove the
subflow which using this local address.
Since we call mptcp_pm_free_anno_list in mptcp_destroy, we need to move
__mptcp_init_sock before the mptcp_is_enabled check in mptcp_init_sock.
Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch added the RM_ADDR option parsing logic:
We parsed the incoming options to find if the rm_addr option is received,
and called mptcp_pm_rm_addr_received to schedule PM work to a new status,
named MPTCP_PM_RM_ADDR_RECEIVED.
PM work got this status, and called mptcp_pm_nl_rm_addr_received to handle
it.
In mptcp_pm_nl_rm_addr_received, we closed the subflow matching the rm_id,
and updated PM counter.
Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes coccicheck warnig:
net/mptcp/protocol.c:164:11-18: WARNING: Unsigned expression compared with zero: max_seq > 0
Fixes: ab174ad8ef ("mptcp: move ooo skbs into msk out of order queue")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
That is needed to let the subflows announce promptly when new
space is available in the receive buffer.
tcp_cleanup_rbuf() is currently a static function, drop the
scope modifier and add a declaration in the TCP header.
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Update the scheduler to less trivial heuristic: cache
the last used subflow, and try to send on it a reasonably
long burst of data.
When the burst or the subflow send space is exhausted, pick
the subflow with the lower ratio between write space and
send buffer - that is, the subflow with the greater relative
amount of free space.
v1 -> v2:
- fix 32 bit build breakage due to 64bits div
- fix checkpath issues (uint64_t -> u64)
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a bunch of MPTCP mibs related to MPTCP OoO data
processing.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add an RB-tree to cope with OoO (at MPTCP level) data.
__mptcp_move_skb() insert into the RB tree "future"
data, eventually coalescing skb as allowed by the
MPTCP DSN.
To simplify sequence accounting, move the DSN inside
the cb.
After successfully enqueuing in sequence data, check
if we can use any data from the RB tree.
Additionally move the data_fin check after spooling
data from the OoO tree, otherwise we could miss shutdown
events.
The RB tree code is copied as verbatim as possible
from tcp_data_queue_ofo(), with a few simplifications
due to the fact that MPTCP doesn't need to cope with
sacks. All bugs here are added by me.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Factor-out existing code, will be re-used by the
next patch.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Let the msk sendbuf track the size of the larger subflow's
send window, so that we ensure mptcp_sendmsg() does not
exceed MPTCP-level send window.
The update is performed just before try to send any data.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a prerequisite to allow receiving data from multiple
subflows without re-injection.
Instead of dropping the OoO - "future" data in
subflow_check_data_avail(), call into __mptcp_move_skbs()
and let the msk drop that.
To avoid code duplication factor out the mptcp_subflow_discard_data()
helper.
Note that __mptcp_move_skbs() can now find multiple subflows
with data avail (comprising to-be-discarded data), so must
update the byte counter incrementally.
v1 -> v2:
- fix checkpatch issues (unsigned -> unsigned int)
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, when checking for the 'msk is writable' condition, we
look at the individual subflows write space.
That works well while we send data via a single subflow, but will
not as soon as we will enable concurrent xmit on multiple subflows.
With this change msk becomes writable when the following conditions
hold:
- the socket has some free write space
- there is at least a subflow with write free space
Additionally we need to set the NOSPACE bit on all subflows
before blocking.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We got slightly different patches removing a double word
in a comment in net/ipv4/raw.c - picked the version from net.
Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached
values instead of VNIC login response buffer (following what
commit 507ebe6444 ("ibmvnic: Fix use-after-free of VNIC login
response buffer") did).
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull networking fixes from David Miller:
1) Use netif_rx_ni() when necessary in batman-adv stack, from Jussi
Kivilinna.
2) Fix loss of RTT samples in rxrpc, from David Howells.
3) Memory leak in hns_nic_dev_probe(), from Dignhao Liu.
4) ravb module cannot be unloaded, fix from Yuusuke Ashizuka.
5) We disable BH for too lokng in sctp_get_port_local(), add a
cond_resched() here as well, from Xin Long.
6) Fix memory leak in st95hf_in_send_cmd, from Dinghao Liu.
7) Out of bound access in bpf_raw_tp_link_fill_link_info(), from
Yonghong Song.
8) Missing of_node_put() in mt7530 DSA driver, from Sumera
Priyadarsini.
9) Fix crash in bnxt_fw_reset_task(), from Michael Chan.
10) Fix geneve tunnel checksumming bug in hns3, from Yi Li.
11) Memory leak in rxkad_verify_response, from Dinghao Liu.
12) In tipc, don't use smp_processor_id() in preemptible context. From
Tuong Lien.
13) Fix signedness issue in mlx4 memory allocation, from Shung-Hsi Yu.
14) Missing clk_disable_prepare() in gemini driver, from Dan Carpenter.
15) Fix ABI mismatch between driver and firmware in nfp, from Louis
Peens.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (110 commits)
net/smc: fix sock refcounting in case of termination
net/smc: reset sndbuf_desc if freed
net/smc: set rx_off for SMCR explicitly
net/smc: fix toleration of fake add_link messages
tg3: Fix soft lockup when tg3_reset_task() fails.
doc: net: dsa: Fix typo in config code sample
net: dp83867: Fix WoL SecureOn password
nfp: flower: fix ABI mismatch between driver and firmware
tipc: fix shutdown() of connectionless socket
ipv6: Fix sysctl max for fib_multipath_hash_policy
drivers/net/wan/hdlc: Change the default of hard_header_len to 0
net: gemini: Fix another missing clk_disable_unprepare() in probe
net: bcmgenet: fix mask check in bcmgenet_validate_flow()
amd-xgbe: Add support for new port mode
net: usb: dm9601: Add USB ID of Keenetic Plus DSL
vhost: fix typo in error message
net: ethernet: mlx4: Fix memory allocation in mlx4_buddy_init()
pktgen: fix error message with wrong function name
net: ethernet: ti: am65-cpsw: fix rmii 100Mbit link mode
cxgb4: fix thermal zone device registration
...
After subflow lock is dropped, more wmem might have been made available.
This fixes a deadlock in mptcp_connect.sh 'mmap' mode: wmem is exhausted.
But as the mptcp socket holds on to already-acked data (for retransmit)
no wakeup will occur.
Using 'goto restart' calls mptcp_clean_una(sk) which will free pages
that have been acked completely in the mean time.
Fixes: fb529e62d3 ("mptcp: break and restart in case mptcp sndbuf is full")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This fix wasn't correct: When this function is invoked from the
retransmission worker, the iterator contains garbage and resetting
it causes a crash.
As the work queue should not be performance critical also zero the
msghdr struct.
Fixes: 3575938313 "(mptcp: sendmsg: reset iter on error)"
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Once we've copied data from the iterator we need to revert in case we
end up not sending any data.
This bug doesn't trigger with normal 'poll' based tests, because
we only feed a small chunk of data to kernel after poll indicated
POLLOUT. With blocking IO and large writes this triggers. Receiver
ends up with less data than it should get.
Fixes: 72511aab95 ("mptcp: avoid blocking in tcp_sendpages")
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In case of memory pressure, mptcp_sendmsg() may call
sk_stream_wait_memory() after succesfully xmitting some
bytes. If the latter fails we currently return to the
user-space the error code, ignoring the succeful xmit.
Address the issue always checking for the xmitted bytes
before mptcp_sendmsg() completes.
Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use mptcp_for_each_subflow in mptcp_stream_accept instead of
open-coding.
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MPTCP socket's write_seq member can be read without the msk lock
held, so use WRITE_ONCE() to store it.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MPTCP socket's write_seq member should be read with READ_ONCE() when
the msk lock is not held.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
RFC 8684 appendix D describes the connection state machine for
MPTCP. This patch implements the DATA_FIN / DATA_ACK exchanges and
MPTCP-level socket state changes described in that appendix, rather than
simply sending DATA_FIN along with TCP FIN when disconnecting subflows.
DATA_FIN is now sent and acknowledged before shutting down the
subflows. Received DATA_FIN information (if not part of a data packet)
is written to the MPTCP socket when the incoming DSS option is parsed by
the subflow, and the MPTCP worker is scheduled to process the
flag. DATA_FIN received as part of a full DSS mapping will be handled
when the mapping is processed.
The DATA_FIN is acknowledged by the worker if the reader is caught
up. If there is still data to be moved to the MPTCP-level queue, ack_seq
will be incremented to account for the DATA_FIN when it reaches the end
of the stream and a DATA_ACK will be sent to the peer.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After DATA_FIN has been sent, the peer will acknowledge it. An ack of
the relevant MPTCP-level sequence number will update the MPTCP
connection state appropriately.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This will be used to transition to the appropriate state on close and
determine if a DATA_FIN needs to be sent for that state transition.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Incoming DATA_FIN headers need to propagate the presence of the DATA_FIN
bit and the associated sequence number to the MPTCP layer, even when
arriving on a bare ACK that does not get added to the receive queue. Add
structure members to store the DATA_FIN information and helpers to set
and check those values.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since DATA_FIN information is the same for every subflow, store it only
in the mptcp_sock.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
mptcp_close() acquires the msk lock, so it clearly should not be held
before the function is called.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A MPTCP socket where sending has been shut down should not attempt to
send additional data, since DATA_FIN has already been sent.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Unblocking sockets used for outgoing connections were not containing
inet info about the initial connection due to a typo there: the value of
"err" variable is negative in the kernelspace.
This fixes the creation of additional subflows where the remote port has
to be reused if the other host didn't announce another one. This also
fixes inet_diag showing blank info about MPTCP sockets from unblocking
sockets doing a connect().
Fixes: 41be81a8d3 ("mptcp: fix unblocking connect()")
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rework the remaining setsockopt code to pass a sockptr_t instead of a
plain user pointer. This removes the last remaining set_fs(KERNEL_DS)
outside of architecture specific code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> [ieee802154]
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently accepted msk sockets become established only after
accept() returns the new sk to user-space.
As MP_JOIN request are refused as per RFC spec on non fully
established socket, the above causes mp_join self-tests
instabilities.
This change lets the msk entering the established status
as soon as it receives the 3rd ack and propagates the first
subflow fully established status on the msk socket.
Finally we can change the subflow acceptance condition to
take in account both the sock state and the msk fully
established flag.
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the unlikely event of a failure at connect time,
we currently clear the request_mptcp flag - so that
the MPC handshake is not started at all, but the msk
is not explicitly marked as fallback.
This would lead to later insertion of wrong DSS options
in the xmitted packets, in violation of RFC specs and
possibly fooling the peer.
Fixes: e1ff9e82e2 ("net: mptcp: improve fallback to TCP")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When updating a partially acked data fragment, we
actually corrupt it. This is irrelevant till we send
data on a single subflow, as retransmitted data, if
any are discarded by the peer as duplicate, but it
will cause data corruption as soon as we will start
creating non backup subflows.
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently we do not init the subflow write sequence for
MP_JOIN subflows. This will cause bad mapping being
generated as soon as we will use non backup subflow.
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the compat handling to sock_common_{get,set}sockopt instead,
keyed of in_compat_syscall(). This allow to remove the now unused
->compat_{get,set}sockopt methods from struct proto_ops.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can re-use the existing work queue to handle path management
instead of a dedicated work queue. Just move pm_worker to protocol.c,
call it from the mptcp worker and get rid of the msk lock (already held).
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Without this, Opensshd fails to open an ipv6 socket listening
socket:
error: setsockopt IPV6_V6ONLY: Operation not supported
error: Bind to port 22 on :: failed: Address already in use.
Opensshd opens an ipv4 and and ipv6 listening socket, but because
IPV6_V6ONLY setsockopt fails, the port number is already in use.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This will e.g. make 'sshd restart' work when MPTCP is used, as we will
now set this option on the listener socket instead of only the mptcp
socket (where it has no effect).
We still need to copy the setting to the master socket so that a
subsequent getsockopt() returns the expected value.
Reported-by: Christoph Paasch <cpaasch@apple.com>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
setsockopt(mptcp_fd, SOL_SOCKET, ...)... appears to work (returns 0),
but it has no effect -- this is because the MPTCP layer never has a
chance to copy the settings to the subflow socket.
Skip the generic handling for the mptcp case and instead call the
mptcp specific handler instead for SOL_SOCKET too.
Next patch adds more specific handling for SOL_SOCKET to mptcp.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
When mptcp is used, userspace doesn't read from the tcp (subflow)
socket but from the parent (mptcp) socket receive queue.
skbs are moved from the subflow socket to the mptcp rx queue either from
'data_ready' callback (if mptcp socket can be locked), a work queue, or
the socket receive function.
This means tcp_rcv_space_adjust() is never called and thus no receive
buffer size auto-tuning is done.
An earlier (not merged) patch added tcp_rcv_space_adjust() calls to the
function that moves skbs from subflow to mptcp socket.
While this enabled autotuning, it also meant tuning was done even if
userspace was reading the mptcp socket very slowly.
This adds mptcp_rcv_space_adjust() and calls it after userspace has
read data from the mptcp socket rx queue.
Its very similar to tcp_rcv_space_adjust, with two differences:
1. The rtt estimate is the largest one observed on a subflow
2. The rcvbuf size and window clamp of all subflows is adjusted
to the mptcp-level rcvbuf.
Otherwise, we get spurious drops at tcp (subflow) socket level if
the skbs are not moved to the mptcp socket fast enough.
Before:
time mptcp_connect.sh -t -f $((4*1024*1024)) -d 300 -l 0.01% -r 0 -e "" -m mmap
[..]
ns4 MPTCP -> ns3 (10.0.3.2:10108 ) MPTCP (duration 40823ms) [ OK ]
ns4 MPTCP -> ns3 (10.0.3.2:10109 ) TCP (duration 23119ms) [ OK ]
ns4 TCP -> ns3 (10.0.3.2:10110 ) MPTCP (duration 5421ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10111) MPTCP (duration 41446ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10112) TCP (duration 23427ms) [ OK ]
ns4 TCP -> ns3 (dead:beef:3::2:10113) MPTCP (duration 5426ms) [ OK ]
Time: 1396 seconds
After:
ns4 MPTCP -> ns3 (10.0.3.2:10108 ) MPTCP (duration 5417ms) [ OK ]
ns4 MPTCP -> ns3 (10.0.3.2:10109 ) TCP (duration 5427ms) [ OK ]
ns4 TCP -> ns3 (10.0.3.2:10110 ) MPTCP (duration 5422ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10111) MPTCP (duration 5415ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10112) TCP (duration 5422ms) [ OK ]
ns4 TCP -> ns3 (dead:beef:3::2:10113) MPTCP (duration 5423ms) [ OK ]
Time: 296 seconds
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
mptcp_poll always return POLLOUT for unblocking
connect(), ensure that the socket is a suitable
state.
The MPTCP_DATA_READY bit is never cleared on accept:
ensure we don't leave mptcp_accept() with an empty
accept queue and such bit set.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently __mptcp_tcp_fallback() always return NULL
on incoming connections, because MPTCP does not create
the additional socket for the first subflow.
Since the previous commit no __mptcp_tcp_fallback()
caller needs a struct socket, so let __mptcp_tcp_fallback()
return the first subflow sock and cope correctly even with
incoming connections.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This cleans the code a bit and makes the behavior more consistent.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This cleanup the code a bit and avoid corrupted states
on weird syscall sequence (accept(), connect()).
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Keep using MPTCP sockets and a use "dummy mapping" in case of fallback
to regular TCP. When fallback is triggered, skip addition of the MPTCP
option on send.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/11
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/22
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace the radix tree with a hash table allocated
at boot time. The radix tree has some shortcoming:
a single lock is contented by all the mptcp operation,
the lookup currently use such lock, and traversing
all the items would require a lock, too.
With hash table instead we trade a little memory to
address all the above - a per bucket lock is used.
To hash the MPTCP sockets, we re-use the msk' sk_node
entry: the MPTCP sockets are never hashed by the stack.
Replace the existing hash proto callbacks with a dummy
implementation, annotating the above constraint.
Additionally refactor the token creation to code to:
- limit the number of consecutive attempts to a fixed
maximum. Hitting a hash bucket with a long chain is
considered a failed attempt
- accept() no longer can fail to token management.
- if token creation fails at connect() time, we do
fallback to TCP (before the connection was closed)
v1 -> v2:
- fix "no newline at end of file" - Jakub
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the missing annotation in some setup-only
functions.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The msk sk_shutdown flag is set by a workqueue, possibly
introducing some delay in user-space notification. If the last
subflow carries some data with the fin packet, the user space
can wake-up before RCV_SHUTDOWN is set. If it executes unblocking
recvmsg(), it may return with an error instead of eof.
Address the issue explicitly checking for eof in recvmsg(), when
no data is found.
Fixes: 59832e2465 ("mptcp: subflow: check parent mptcp socket on subflow state change")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
xdp_umem.c had overlapping changes between the 64-bit math fix
for the calculation of npgs and the removal of the zerocopy
memory type which got rid of the chunk_size_nohdr member.
The mlx5 Kconfig conflict is a case where we just take the
net-next copy of the Kconfig entry dependency as it takes on
the ESWITCH dependency by one level of indirection which is
what the 'net' conflicting change is trying to ensure.
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently we remote the msk from the token container only
via mptcp_close(). The MPTCP master socket can be destroyed
also via other paths (e.g. if not yet accepted, when shutting
down the listener socket). When we hit the latter scenario,
dangling msk references are left into the token container,
leading to memory corruption and/or UaF.
This change addresses the issue by moving the token removal
into the msk destructor.
Fixes: 79c0949e9a ("mptcp: Add key generation and token tree")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a MP_JOIN subflow completes the 3whs while another
CPU is closing the master msk, we can hit the
following race:
CPU1 CPU2
close()
mptcp_close
subflow_syn_recv_sock
mptcp_token_get_sock
mptcp_finish_join
inet_sk_state_load
mptcp_token_destroy
inet_sk_state_store(TCP_CLOSE)
__mptcp_flush_join_list()
mptcp_sock_graft
list_add_tail
sk_common_release
sock_orphan()
<socket free>
The MP_JOIN socket will be leaked. Additionally we can hit
UaF for the msk 'struct socket' referenced via the 'conn'
field.
This change try to address the issue introducing some
synchronization between the MP_JOIN 3whs and mptcp_close
via the join_list spinlock. If we detect the msk is closing
the MP_JOIN socket is closed, too.
Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently unblocking connect() on MPTCP sockets fails frequently.
If mptcp_stream_connect() is invoked to complete a previously
attempted unblocking connection, it will still try to create
the first subflow via __mptcp_socket_create(). If the 3whs is
completed and the 'can_ack' flag is already set, the latter
will fail with -EINVAL.
This change addresses the issue checking for pending connect and
delegating the completion to the first subflow. Additionally
do msk addresses and sk_state changes only when needed.
Fixes: 2303f994b3 ("mptcp: Associate MPTCP context with TCP socket")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can try to coalesce skbs we take from the subflows rx queue with the
tail of the mptcp rx queue.
If successful, the skb head can be discarded early.
We can also free the skb extensions, we do not access them after this.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
To prepare removing the global routing_ioctl hack start lifting the code
into a newly added ipv6 ->compat_ioctl handler.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
mptcp calls this from the transmit side, from process context.
Allow a sleeping allocation instead of unconditional GFP_ATOMIC.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
previous patches made sure we only call into this function
when these prerequisites are met, so no need to wait on the
subflow socket anymore.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/7
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The mptcp_sendmsg_frag helper contains a loop that will wait on the
subflow sk.
It seems preferrable to only wait in mptcp_sendmsg() when blocking io is
requested. mptcp_sendmsg already has such a wait loop that is used when
no subflow socket is available for transmission.
This is another preparation patch that makes sure we call
mptcp_sendmsg_frag only if the page frag cache has been refilled.
Followup patch will remove the wait loop from mptcp_sendmsg_frag().
The retransmit worker doesn't need to do this refill as it won't
transmit new mptcp-level data.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The mptcp_sendmsg_frag helper contains a loop that will wait on the
subflow sk.
It seems preferrable to only wait in mptcp_sendmsg() when blocking io is
requested. mptcp_sendmsg already has such a wait loop that is used when
no subflow socket is available for transmission.
This is a preparation patch that makes sure we call
mptcp_sendmsg_frag only if a skb extension has been allocated.
Moreover, such allocation currently uses GFP_ATOMIC while it
could use sleeping allocation instead.
Followup patches will remove the wait loop from mptcp_sendmsg_frag()
and will allow to do a sleeping allocation for the extension.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The transmit loop continues to xmit new data until an error is returned
or all data was transmitted.
For the blocking i/o case, this means that tcp_sendpages() may block on
the subflow until more space becomes available, i.e. we end up sleeping
with the mptcp socket lock held.
Instead we should check if a different subflow is ready to be used.
This restarts the subflow sk lookup when the tx operation succeeded
and the tcp subflow can't accept more data or if tcp_sendpages
indicates -EAGAIN on a blocking mptcp socket.
In that case we also need to set the NOSPACE bit to make sure we get
notified once memory becomes available.
In case all subflows are busy, the existing logic will wait until a
subflow is ready, releasing the mptcp socket lock while doing so.
The mptcp worker already sets DONTWAIT, so no need to make changes there.
v2:
* set NOSPACE bit
* add a comment to clarify that mptcp-sk sndbuf limits need to
be checked as well.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Its not enough to check for available tcp send space.
We also hold on to transmitted data for mptcp-level retransmits.
Right now we will send more and more data if the peer can ack data
at the tcp level fast enough, since that frees up tcp send buffer space.
But we also need to check that data was acked and reclaimed at the mptcp
level.
Therefore add needed check in mptcp_sendmsg, flush tcp data and
wait until more mptcp snd space becomes available if we are over the
limit. Before we wait for more data, also make sure we start the
retransmit timer if we ran out of sndbuf space.
Otherwise there is a very small chance that we wait forever:
* receiver is waiting for data
* sender is blocked because mptcp socket buffer is full
* at tcp level, all data was acked
* mptcp-level snd_una was not updated, because last ack
that acknowledged the last data packet carried an older
MPTCP-ack.
Restarting the retransmit timer avoids this problem: if TCP
subflow is idle, data is retransmitted from the RTX queue.
New data will make the peer send a new, updated MPTCP-Ack.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Paolo noticed that ssk_check_wmem() has same pattern, so add/use
common helper for both places.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the bpf verifier trace check into the new switch statement in
HEAD.
Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.
Signed-off-by: David S. Miller <davem@davemloft.net>
MP_JOIN subflows must not land into the accept queue.
Currently tcp_check_req() calls an mptcp specific helper
to detect such scenario.
Such helper leverages the subflow context to check for
MP_JOIN subflows. We need to deal also with MP JOIN
failures, even when the subflow context is not available
due allocation failure.
A possible solution would be changing the syn_recv_sock()
signature to allow returning a more descriptive action/
error code and deal with that in tcp_check_req().
Since the above need is MPTCP specific, this patch instead
uses a TCP request socket hole to add a MPTCP specific flag.
Such flag is used by the MPTCP syn_recv_sock() to tell
tcp_check_req() how to deal with the request socket.
This change is a no-op for !MPTCP build, and makes the
MPTCP code simpler. It allows also the next patch to deal
correctly with MP JOIN failure.
v1 -> v2:
- be more conservative on drop_req initialization (Mat)
RFC -> v1:
- move the drop_req bit inside tcp_request_sock (Eric)
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the other MPTCP-peer uses 32-bit data-sequence numbers, we rely on
map_seq to indicate how to expand to a 64-bit data-sequence number in
expand_seq() when receiving data.
For new subflows, this field is not initialized, thus results in an
"invalid" mapping being discarded.
Fix this by initializing map_seq upon subflow establishment time.
Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Paolo points out that mptcp_disconnect is bogus:
"lock_sock(sk);
looks suspicious (lock should be already held by the caller)
And call to: tcp_disconnect(sk, flags); too, sk is not a tcp
socket".
->disconnect() gets called from e.g. inet_stream_connect when
one tries to disassociate a connected socket again (to re-connect
without closing the socket first).
MPTCP however uses mptcp_stream_connect, not inet_stream_connect,
for the mptcp-socket connect call.
inet_stream_connect only gets called indirectly, for the tcp socket,
so any ->disconnect() calls end up calling tcp_disconnect for that
tcp subflow sk.
This also explains why syzkaller has not yet reported a problem
here. So for now replace this with a stub that doesn't do anything.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/14
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
We don't need them, as we can use the current ingress opt
data instead. Setting them in syn_recv_sock() may causes
inconsistent mptcp socket status, as per previous commit.
Fixes: cc7972ea19 ("mptcp: parse and emit MP_CAPABLE option according to v1 spec")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Following splat can occur during self test:
BUG: KASAN: use-after-free in subflow_data_ready+0x156/0x160
Read of size 8 at addr ffff888100c35c28 by task mptcp_connect/4808
subflow_data_ready+0x156/0x160
tcp_child_process+0x6a3/0xb30
tcp_v4_rcv+0x2231/0x3730
ip_protocol_deliver_rcu+0x5c/0x860
ip_local_deliver_finish+0x220/0x360
ip_local_deliver+0x1c8/0x4e0
ip_rcv_finish+0x1da/0x2f0
ip_rcv+0xd0/0x3c0
__netif_receive_skb_one_core+0xf5/0x160
__netif_receive_skb+0x27/0x1c0
process_backlog+0x21e/0x780
net_rx_action+0x35f/0xe90
do_softirq+0x4c/0x50
[..]
This occurs when accessing subflow_ctx->conn.
Problem is that tcp_child_process() calls listen sockets'
sk_data_ready() notification, but it doesn't hold the listener
lock. Another cpu calling close() on the listener will then cause
transition of refcount to 0.
Fixes: 58b0991962 ("mptcp: create msk early")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to set sk_state to CLOSED, else we will get following:
IPv4: Attempt to release TCP socket in state 3 00000000b95f109e
IPv4: Attempt to release TCP socket in state 10 00000000b95f109e
First one is from inet_sock_destruct(), second one from
mptcp_sk_clone failure handling. Setting sk_state to CLOSED isn't
enough, we also need to orphan sk so it has DEAD flag set.
Otherwise, a very similar warning is printed from inet_sock_destruct().
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Following snippet (replicated from syzkaller reproducer) generates
warning: "IPv4: Attempt to release TCP socket in state 1".
int main(void) {
struct sockaddr_in sin1 = { .sin_family = 2, .sin_port = 0x4e20,
.sin_addr.s_addr = 0x010000e0, };
struct sockaddr_in sin2 = { .sin_family = 2,
.sin_addr.s_addr = 0x0100007f, };
struct sockaddr_in sin3 = { .sin_family = 2, .sin_port = 0x4e20,
.sin_addr.s_addr = 0x0100007f, };
int r0 = socket(0x2, 0x1, 0x106);
int r1 = socket(0x2, 0x1, 0x106);
bind(r1, (void *)&sin1, sizeof(sin1));
connect(r1, (void *)&sin2, sizeof(sin2));
listen(r1, 3);
return connect(r0, (void *)&sin3, 0x4d);
}
Reason is that the newly generated mptcp socket is closed via the ulp
release of the tcp listener socket when its accept backlog gets purged.
To fix this, delay setting the ESTABLISHED state until after userspace
calls accept and via mptcp specific destructor.
Fixes: 58b0991962 ("mptcp: create msk early")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/9
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
mptcp_connect/28740 is trying to release lock (sk_lock-AF_INET) at:
[<ffffffff82c15869>] mptcp_poll+0xb9/0x550
but there are no more locks to release!
Call Trace:
lock_release+0x50f/0x750
release_sock+0x171/0x1b0
mptcp_poll+0xb9/0x550
sock_poll+0x157/0x470
? get_net_ns+0xb0/0xb0
do_sys_poll+0x63c/0xdd0
Problem is that __mptcp_tcp_fallback() releases the mptcp socket lock,
but after recent change it doesn't do this in all of its return paths.
To fix this, remove the unlock from __mptcp_tcp_fallback() and
always do the unlock in the caller.
Also add a small comment as to why we have this
__mptcp_needs_tcp_fallback().
Fixes: 0b4f33def7 ("mptcp: fix tcp fallback crash")
Reported-by: syzbot+e56606435b7bfeea8cf5@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
mptcp_subflow_data_available() is commonly called via
ssk->sk_data_ready(), in this case the mptcp socket lock
cannot be acquired.
Therefore, while we can safely discard subflow data that
was already received up to msk->ack_seq, we cannot be sure
that 'subflow->data_avail' will still be valid at the time
userspace wants to read the data -- a previous read on a
different subflow might have carried this data already.
In that (unlikely) event, msk->ack_seq will have been updated
and will be ahead of the subflow dsn.
We can check for this condition and skip/resync to the expected
sequence number.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is needed at least until proper MPTCP-Level fin/reset
signalling gets added:
We wake parent when a subflow changes, but we should do this only
when all subflows have closed, not just one.
Schedule the mptcp worker and tell it to check eof state on all
subflows.
Only flag mptcp socket as closed and wake userspace processes blocking
in poll if all subflows have closed.
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Christoph Paasch reports following crash:
general protection fault [..]
CPU: 0 PID: 2874 Comm: syz-executor072 Not tainted 5.6.0-rc5 #62
RIP: 0010:__pv_queued_spin_lock_slowpath kernel/locking/qspinlock.c:471
[..]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:50 [inline]
do_raw_spin_lock include/linux/spinlock.h:181 [inline]
spin_lock_bh include/linux/spinlock.h:343 [inline]
__mptcp_flush_join_list+0x44/0xb0 net/mptcp/protocol.c:278
mptcp_shutdown+0xb3/0x230 net/mptcp/protocol.c:1882
[..]
Problem is that mptcp_shutdown() socket isn't an mptcp socket,
its a plain tcp_sk. Thus, trying to access mptcp_sk specific
members accesses garbage.
Root cause is that accept() returns a fallback (tcp) socket, not an mptcp
one. There is code in getpeername to detect this and override the sockets
stream_ops. But this will only run when accept() caller provided a
sockaddr struct. "accept(fd, NULL, 0)" will therefore result in
mptcp stream ops, but with sock->sk pointing at a tcp_sk.
Update the existing fallback handling to detect this as well.
Moreover, mptcp_shutdown did not have fallback handling, and
mptcp_poll did it too late so add that there as well.
Reported-by: Christoph Paasch <cpaasch@apple.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Exported via same /proc file as the Linux TCP MIB counters, so "netstat -s"
or "nstat" will show them automatically.
The MPTCP MIB counters are allocated in a distinct pcpu area in order to
avoid bloating/wasting TCP pcpu memory.
Counters are allocated once the first MPTCP socket is created in a
network namespace and free'd on exit.
If no sockets have been allocated, all-zero mptcp counters are shown.
The MIB counter list is taken from the multipath-tcp.org kernel, but
only a few counters have been picked up so far. The counter list can
be increased at any time later on.
v2 -> v3:
- remove 'inline' in foo.c files (David S. Miller)
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On timeout event, schedule a work queue to do the retransmission.
Retransmission code closely resembles the sendmsg() implementation and
re-uses mptcp_sendmsg_frag, providing a dummy msghdr - for flags'
sake - and peeking the relevant dfrag from the rtx head.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This will simplify mptcp-level retransmission implementation
in the next patch. If dfrag is provided by the caller, skip
kernel space memory allocation and use data and metadata
provided by the dfrag itself.
Because a peer could ack data at TCP level but refrain from
sending mptcp-level ACKs, we could grow the mptcp socket
backlog indefinitely.
We should thus block mptcp_sendmsg until the peer has acked some of the
sent data.
In order to be able to do so, increment the mptcp socket wmem_queued
counter on memory allocation and decrement it when releasing the memory
on mptcp-level ack reception.
Because TCP performns sndbuf auto-tuning up to tcp_wmem_max[2], make
this the mptcp sk_sndbuf limit.
In the future we could add experiment with autotuning as TCP does in
tcp_sndbuf_expand().
v2 -> v3:
- remove 'inline' in foo.c files (David S. Miller)
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After adding wmem accounting for the mptcp socket we could get
into a situation where the mptcp socket can't transmit more data,
and mptcp_clean_una doesn't reduce wmem even if snd_una has advanced
because it currently will only remove entire dfrags.
Allow advancing the dfrag head sequence and reduce wmem,
even though this isn't correct (as we can't release the page).
Because we will soon block on mptcp sk in case wmem is too large,
call sk_stream_write_space() in case we reduced the backlog so
userspace task blocked in sendmsg or poll will be woken up.
This isn't an issue if the send buffer is large, but it is when
SO_SNDBUF is used to reduce it to a lower value.
Note we can still get a deadlock for low SO_SNDBUF values in
case both sides of the connection write to the socket: both could
be blocked due to wmem being too small -- and current mptcp stack
will only increment mptcp ack_seq on recv.
This doesn't happen with the selftest as it uses poll() and
will always call recv if there is data to read.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Charge the data on the rtx queue to the master MPTCP socket, too.
Such memory in uncharged when the data is acked/dequeued.
Also account mptcp sockets inuse via a protocol specific pcpu
counter.
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The timer will be used to schedule retransmission. It's
frequency is based on the current subflow RTO estimation and
is reset on every una_seq update
The timer is clearer for good by __mptcp_clear_xmit()
Also clean MPTCP rtx queue before each transmission.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Keep the send page fragment on an MPTCP level retransmission queue.
The queue entries are allocated inside the page frag allocator,
acquiring an additional reference to the page for each list entry.
Also switch to a custom page frag refill function, to ensure that
the current page fragment can always host an MPTCP rtx queue entry.
The MPTCP rtx queue is flushed at disconnect() and close() time
Note that now we need to call __mptcp_init_sock() regardless of mptcp
enable status, as the destructor will try to walk the rtx_queue.
v2 -> v3:
- remove 'inline' in foo.c files (David S. Miller)
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
So that we keep per unacked sequence number consistent; since
we update per msk data, use an atomic64 cmpxchg() to protect
against concurrent updates from multiple subflows.
Initialize the snd_una at connect()/accept() time.
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
Subflow creation may be initiated by the path manager when
the primary connection is fully established and a remote
address has been received via ADD_ADDR.
Create an in-kernel sock and use kernel_connect() to
initiate connection.
Passive sockets can't acquire the mptcp socket lock at
subflow creation time, so an additional list protected by
a new spinlock is used to track the MPJ subflows.
Such list is spliced into conn_list tail every time the msk
socket lock is acquired, so that it will not interfere
with data flow on the original connection.
Data flow and connection failover not addressed by this commit.
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>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
Process the MP_JOIN option in a SYN packet with the same flow
as MP_CAPABLE but when the third ACK is received add the
subflow to the MPTCP socket subflow list instead of adding it to
the TCP socket accept queue.
The subflow is added at the end of the subflow list so it will not
interfere with the existing subflows operation and no data is
expected to be transmitted on it.
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>
Add enough of a path manager interface to allow sending of ADD_ADDR
when an incoming MPTCP connection is created. Capable of sending only
a single IPv4 ADD_ADDR option. The 'pm_data' element of the connection
sock will need to be expanded to handle multiple interfaces and IPv6.
Partial processing of the incoming ADD_ADDR is included so the path
manager notification of that event happens at the proper time, which
involves validating the incoming address information.
This is a skeleton interface definition for events generated by
MPTCP.
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
Co-developed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
it's still possible for packetdrill to hang in mptcp_sendmsg(), when the
MPTCP socket falls back to regular TCP (e.g. after receiving unsupported
flags/version during the three-way handshake). Adjust MPTCP socket state
earlier, to ensure correct functionality of mptcp_sendmsg() even in case
of TCP fallback.
Fixes: 767d3ded5f ("net: mptcp: don't hang before sending 'MP capable with data'")
Fixes: 1954b86016 ("mptcp: Check connection state before attempting send")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit 58b0991962 ("mptcp: create msk early"), the
msk socket is already available at subflow_syn_recv_sock()
time. Let's move there the state update, to mirror more
closely the first subflow state.
The above will also help multiple subflow supports.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change moves the mptcp socket allocation from mptcp_accept() to
subflow_syn_recv_sock(), so that subflow->conn is now always set
for the non fallback scenario.
It allows cleaning up a bit mptcp_accept() reducing the additional
locking and will allow fourther cleanup in the next patch.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The mptcp rcvbuf size is adjusted according to the subflow rcvbuf size.
This should not be done if userspace did set a fixed value.
Fixes: 600911ff5f ("mptcp: add rmem queue accounting")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of reading the MPTCP-level sequence number when sending DATA_FIN,
store the data in the subflow so it can be safely accessed when the
subflow TCP headers are written to the packet without the MPTCP-level
lock held. This also allows the MPTCP-level socket to close individual
subflows without closing the MPTCP connection.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
MPTCP should wait for an active connection or skip sending depending on
the connection state, as TCP does. This happens before the possible
passthrough to a regular TCP sendmsg because the subflow's socket type
(MPTCP or TCP fallback) is not known until the connection is
complete. This is also relevent at disconnect time, where data should
not be sent in certain MPTCP-level connection states.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The mptcp conflict was overlapping additions.
The SMC conflict was an additional and removal happening at the same
time.
Signed-off-by: David S. Miller <davem@davemloft.net>
Don't schedule the work queue right away, instead defer this
to the lock release callback.
This has the advantage that it will give recv path a chance to
complete -- this might have moved all pending packets from the
subflow to the mptcp receive queue, which allows to avoid the
schedule_work().
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can't lock_sock() the mptcp socket from the subflow data_ready callback,
it would result in ABBA deadlock with the subflow socket lock.
We can however grab the spinlock: if that succeeds and the mptcp socket
is not owned at the moment, we can process the new skbs right away
without deferring this to the work queue.
This avoids the schedule_work and hence the small delay until the
work item is processed.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Only used to discard stale data from the subflow, so move
it where needed.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If userspace never drains the receive buffers we must stop draining
the subflow socket(s) at some point.
This adds the needed rmem accouting for this.
If the threshold is reached, we stop draining the subflows.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If userspace is not reading data, all the mptcp-level acks contain the
ack_seq from the last time userspace read data rather than the most
recent in-sequence value.
This causes pointless retransmissions for data that is already queued.
The reason for this is that all the mptcp protocol level processing
happens at mptcp_recv time.
This adds work queue to move skbs from the subflow sockets receive
queue on the mptcp socket receive queue (which was not used so far).
This allows us to announce the correct mptcp ack sequence in a timely
fashion, even when the application does not call recv() on the mptcp socket
for some time.
We still wake userspace tasks waiting for POLLIN immediately:
If the mptcp level receive queue is empty (because the work queue is
still pending) it can be filled from in-sequence subflow sockets at
recv time without a need to wait for the worker.
The skb_orphan when moving skbs from subflow to mptcp level is needed,
because the destructor (sock_rfree) relies on skb->sk (ssk!) lock
being taken.
A followup patch will add needed rmem accouting for the moved skbs.
Other problem: In case application behaves as expected, and calls
recv() as soon as mptcp socket becomes readable, the work queue will
only waste cpu cycles. This will also be addressed in followup patches.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Will be extended with functionality in followup patches.
Initial user is moving skbs from subflows receive queue to
the mptcp-level receive queue.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
allows us to schedule the work queue to drain the ssk receive queue in
a followup patch.
This is needed to avoid sending all-to-pessimistic mptcp-level
acknowledgements. At this time, the ack_seq is what was last read by
userspace instead of the highest in-sequence number queued for reading.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Userspace should not be able to directly manipulate subflow socket
options before a connection is established since it is not yet known if
it will be an MPTCP subflow or a TCP fallback subflow. TCP fallback
subflows can be more directly controlled by userspace because they are
regular TCP connections, while MPTCP subflow sockets need to be
configured for the specific needs of MPTCP. Use the same logic as
sendmsg/recvmsg to ensure that socket option calls are only passed
through to known TCP fallback subflows.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix the following sparse warning:
net/mptcp/protocol.c:646:13: warning: symbol 'mptcp_sk_clone_lock' was not declared. Should it be static?
Fixes: b0519de8b3 ("mptcp: fix use-after-free for ipv6")
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Turns out that when we accept a new subflow, the newly created
inet_sk(tcp_sk)->pinet6 points at the ipv6_pinfo structure of the
listener socket.
This wasn't caught by the selftest because it closes the accepted fd
before the listening one.
adding a close(listenfd) after accept returns is enough:
BUG: KASAN: use-after-free in inet6_getname+0x6ba/0x790
Read of size 1 at addr ffff88810e310866 by task mptcp_connect/2518
Call Trace:
inet6_getname+0x6ba/0x790
__sys_getpeername+0x10b/0x250
__x64_sys_getpeername+0x6f/0xb0
also alter test program to exercise this.
Reported-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
When an mptcp socket connects to a tcp peer or when a middlebox interferes
with tcp options, mptcp needs to fall back to plain tcp.
Problem is that mptcp is trying to be too clever in this case:
It attempts to close the mptcp meta sk and transparently replace it with
the (only) subflow tcp sk.
Unfortunately, this is racy -- the socket is already exposed to userspace.
Any parallel calls to send/recv/setsockopt etc. can cause use-after-free:
BUG: KASAN: use-after-free in atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:693 [inline]
CPU: 1 PID: 2083 Comm: syz-executor.1 Not tainted 5.5.0 #2
atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:693 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:78 [inline]
do_raw_spin_lock include/linux/spinlock.h:181 [inline]
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
_raw_spin_lock_bh+0x71/0xd0 kernel/locking/spinlock.c:175
spin_lock_bh include/linux/spinlock.h:343 [inline]
__lock_sock+0x105/0x190 net/core/sock.c:2414
lock_sock_nested+0x10f/0x140 net/core/sock.c:2938
lock_sock include/net/sock.h:1516 [inline]
mptcp_setsockopt+0x2f/0x1f0 net/mptcp/protocol.c:800
__sys_setsockopt+0x152/0x240 net/socket.c:2130
__do_sys_setsockopt net/socket.c:2146 [inline]
__se_sys_setsockopt net/socket.c:2143 [inline]
__x64_sys_setsockopt+0xba/0x150 net/socket.c:2143
do_syscall_64+0xb7/0x3d0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x44/0xa9
While the use-after-free can be resolved, there is another problem:
sock->ops and sock->sk assignments are not atomic, i.e. we may get calls
into mptcp functions with sock->sk already pointing at the subflow socket,
or calls into tcp functions with a mptcp meta sk.
Remove the fallback code and call the relevant functions for the (only)
subflow in case the mptcp socket is connected to tcp peer.
Reported-by: Christoph Paasch <cpaasch@apple.com>
Diagnosed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If CONFIG_MPTCP=y, CONFIG_MPTCP_IPV6=n, and CONFIG_IPV6=m:
net/mptcp/protocol.o: In function `__mptcp_tcp_fallback':
protocol.c:(.text+0x786): undefined reference to `inet6_stream_ops'
Fix this by checking for CONFIG_MPTCP_IPV6 instead of CONFIG_IPV6, like
is done in all other places in the mptcp code.
Fixes: 8ab183deb2 ("mptcp: cope with later TCP fallback")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
syzbot triggered following lockdep splat:
ffffffff82d2cd40 (rtnl_mutex){+.+.}, at: ip_mc_drop_socket+0x52/0x180
but task is already holding lock:
ffff8881187a2310 (sk_lock-AF_INET){+.+.}, at: mptcp_close+0x18/0x30
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (sk_lock-AF_INET){+.+.}:
lock_acquire+0xee/0x230
lock_sock_nested+0x89/0xc0
do_ip_setsockopt.isra.0+0x335/0x22f0
ip_setsockopt+0x35/0x60
tcp_setsockopt+0x5d/0x90
__sys_setsockopt+0xf3/0x190
__x64_sys_setsockopt+0x61/0x70
do_syscall_64+0x72/0x300
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #0 (rtnl_mutex){+.+.}:
check_prevs_add+0x2b7/0x1210
__lock_acquire+0x10b6/0x1400
lock_acquire+0xee/0x230
__mutex_lock+0x120/0xc70
ip_mc_drop_socket+0x52/0x180
inet_release+0x36/0xe0
__sock_release+0xfd/0x130
__mptcp_close+0xa8/0x1f0
inet_release+0x7f/0xe0
__sock_release+0x69/0x130
sock_close+0x18/0x20
__fput+0x179/0x400
task_work_run+0xd5/0x110
do_exit+0x685/0x1510
do_group_exit+0x7e/0x170
__x64_sys_exit_group+0x28/0x30
do_syscall_64+0x72/0x300
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The trigger is:
socket(AF_INET, SOCK_STREAM, 0x106 /* IPPROTO_MPTCP */) = 4
setsockopt(4, SOL_IP, MCAST_JOIN_GROUP, {gr_interface=7, gr_group={sa_family=AF_INET, sin_port=htons(20003), sin_addr=inet_addr("224.0.0.2")}}, 136) = 0
exit(0)
Which results in a call to rtnl_lock while we are holding
the parent mptcp socket lock via
mptcp_close -> lock_sock(msk) -> inet_release -> ip_mc_drop_socket -> rtnl_lock().
>From lockdep point of view we thus have both
'rtnl_lock; lock_sock' and 'lock_sock; rtnl_lock'.
Fix this by stealing the msk conn_list and doing the subflow close
without holding the msk lock.
Fixes: cec37a6e41 ("mptcp: Handle MP_CAPABLE options for outgoing connections")
Reported-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Its not possible to call the kernel_(s|g)etsockopt functions here,
the address points to user memory:
General protection fault in user access. Non-canonical address?
WARNING: CPU: 1 PID: 5352 at arch/x86/mm/extable.c:77 ex_handler_uaccess+0xba/0xe0 arch/x86/mm/extable.c:77
Kernel panic - not syncing: panic_on_warn set ...
[..]
Call Trace:
fixup_exception+0x9d/0xcd arch/x86/mm/extable.c:178
general_protection+0x2d/0x40 arch/x86/entry/entry_64.S:1202
do_ip_getsockopt+0x1f6/0x1860 net/ipv4/ip_sockglue.c:1323
ip_getsockopt+0x87/0x1c0 net/ipv4/ip_sockglue.c:1561
tcp_getsockopt net/ipv4/tcp.c:3691 [inline]
tcp_getsockopt+0x8c/0xd0 net/ipv4/tcp.c:3685
kernel_getsockopt+0x121/0x1f0 net/socket.c:3736
mptcp_getsockopt+0x69/0x90 net/mptcp/protocol.c:830
__sys_getsockopt+0x13a/0x220 net/socket.c:2175
We can call tcp_get/setsockopt functions instead. Doing so fixes
crashing, but still leaves rtnl related lockdep splat:
WARNING: possible circular locking dependency detected
5.5.0-rc6 #2 Not tainted
------------------------------------------------------
syz-executor.0/16334 is trying to acquire lock:
ffffffff84f7a080 (rtnl_mutex){+.+.}, at: do_ip_setsockopt.isra.0+0x277/0x3820 net/ipv4/ip_sockglue.c:644
but task is already holding lock:
ffff888116503b90 (sk_lock-AF_INET){+.+.}, at: lock_sock include/net/sock.h:1516 [inline]
ffff888116503b90 (sk_lock-AF_INET){+.+.}, at: mptcp_setsockopt+0x28/0x90 net/mptcp/protocol.c:1284
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (sk_lock-AF_INET){+.+.}:
lock_sock_nested+0xca/0x120 net/core/sock.c:2944
lock_sock include/net/sock.h:1516 [inline]
do_ip_setsockopt.isra.0+0x281/0x3820 net/ipv4/ip_sockglue.c:645
ip_setsockopt+0x44/0xf0 net/ipv4/ip_sockglue.c:1248
udp_setsockopt+0x5d/0xa0 net/ipv4/udp.c:2639
__sys_setsockopt+0x152/0x240 net/socket.c:2130
__do_sys_setsockopt net/socket.c:2146 [inline]
__se_sys_setsockopt net/socket.c:2143 [inline]
__x64_sys_setsockopt+0xba/0x150 net/socket.c:2143
do_syscall_64+0xbd/0x5b0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #0 (rtnl_mutex){+.+.}:
check_prev_add kernel/locking/lockdep.c:2475 [inline]
check_prevs_add kernel/locking/lockdep.c:2580 [inline]
validate_chain kernel/locking/lockdep.c:2970 [inline]
__lock_acquire+0x1fb2/0x4680 kernel/locking/lockdep.c:3954
lock_acquire+0x127/0x330 kernel/locking/lockdep.c:4484
__mutex_lock_common kernel/locking/mutex.c:956 [inline]
__mutex_lock+0x158/0x1340 kernel/locking/mutex.c:1103
do_ip_setsockopt.isra.0+0x277/0x3820 net/ipv4/ip_sockglue.c:644
ip_setsockopt+0x44/0xf0 net/ipv4/ip_sockglue.c:1248
tcp_setsockopt net/ipv4/tcp.c:3159 [inline]
tcp_setsockopt+0x8c/0xd0 net/ipv4/tcp.c:3153
kernel_setsockopt+0x121/0x1f0 net/socket.c:3767
mptcp_setsockopt+0x69/0x90 net/mptcp/protocol.c:1288
__sys_setsockopt+0x152/0x240 net/socket.c:2130
__do_sys_setsockopt net/socket.c:2146 [inline]
__se_sys_setsockopt net/socket.c:2143 [inline]
__x64_sys_setsockopt+0xba/0x150 net/socket.c:2143
do_syscall_64+0xbd/0x5b0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sk_lock-AF_INET);
lock(rtnl_mutex);
lock(sk_lock-AF_INET);
lock(rtnl_mutex);
The lockdep complaint is because we hold mptcp socket lock when calling
the sk_prot get/setsockopt handler, and those might need to acquire the
rtnl mutex. Normally, order is:
rtnl_lock(sk) -> lock_sock
Whereas for mptcp the order is
lock_sock(mptcp_sk) rtnl_lock -> lock_sock(subflow_sk)
We can avoid this by releasing the mptcp socket lock early, but, as Paolo
points out, we need to get/put the subflow socket refcount before doing so
to avoid race with concurrent close().
Fixes: 717e79c867 ("mptcp: Add setsockopt()/getsockopt() socket operations")
Reported-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
access to msk->cached_ext is only legal if the msk is locked or all
concurrent accesses are impossible.
Furthermore, once we start to tear down, we must make sure nothing else
can step in and allocate a new cached ext.
So place this code in the destroy callback where it belongs.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
checkpatch.pl had a few complaints in the last set of MPTCP patches:
ERROR: code indent should use tabs where possible
+^I subflow, sk->sk_family, icsk->icsk_af_ops, target, mapped);$
CHECK: Comparison to NULL could be written "!new_ctx"
+ if (new_ctx == NULL) {
ERROR: "foo * bar" should be "foo *bar"
+static const struct proto_ops * tcp_proto_ops(struct sock *sk)
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to initialise the struct ourselves, else we expose tcp-specific
callbacks such as tcp_splice_read which will then trigger splat because
the socket is an mptcp one:
BUG: KASAN: slab-out-of-bounds in tcp_mstamp_refresh+0x80/0xa0 net/ipv4/tcp_output.c:57
Write of size 8 at addr ffff888116aa21d0 by task syz-executor.0/5478
CPU: 1 PID: 5478 Comm: syz-executor.0 Not tainted 5.5.0-rc6 #3
Call Trace:
tcp_mstamp_refresh+0x80/0xa0 net/ipv4/tcp_output.c:57
tcp_rcv_space_adjust+0x72/0x7f0 net/ipv4/tcp_input.c:612
tcp_read_sock+0x622/0x990 net/ipv4/tcp.c:1674
tcp_splice_read+0x20b/0xb40 net/ipv4/tcp.c:791
do_splice+0x1259/0x1560 fs/splice.c:1205
To prevent build error with ipv6, add the recv/sendmsg function
declaration to ipv6.h. The functions are already accessible "thanks"
to retpoline related work, but they are currently only made visible
by socket.c specific INDIRECT_CALLABLE macros.
Reported-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With MPTCP v1, passive connections can fallback to TCP after the
subflow becomes established:
syn + MP_CAPABLE ->
<- syn, ack + MP_CAPABLE
ack, seq = 3 ->
// OoO packet is accepted because in-sequence
// passive socket is created, is in ESTABLISHED
// status and tentatively as MP_CAPABLE
ack, seq = 2 ->
// no MP_CAPABLE opt, subflow should fallback to TCP
We can't use the 'subflow' socket fallback, as we don't have
it available for passive connection.
Instead, when the fallback is detected, replace the mptcp
socket with the underlying TCP subflow. Beyond covering
the above scenario, it makes a TCP fallback socket as efficient
as plain TCP ones.
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implements the handling of MP_CAPABLE + data option, as per
RFC 6824 bis / RFC 8684: MPTCP v1.
On the server side we can receive the remote key after that the connection
is established. We need to explicitly track the 'missing remote key'
status and avoid emitting a mptcp ack until we get such info.
When a late/retransmitted/OoO pkt carrying MP_CAPABLE[+data] option
is received, we have to propagate the mptcp seq number info to
the msk socket. To avoid ABBA locking issue, explicitly check for
that in recvmsg(), where we own msk and subflow sock locks.
The above also means that an established mp_capable subflow - still
waiting for the remote key - can be 'downgraded' to plain TCP.
Such change could potentially block a reader waiting for new data
forever - as they hook to msk, while later wake-up after the downgrade
will be on subflow only.
The above issue is not handled here, we likely have to get rid of
msk->fallback to handle that cleanly.
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
New MPTCP sockets will return -ENOPROTOOPT if MPTCP support is disabled
for the current net namespace.
We are providing here a way to control access to the feature for those
that need to turn it on or off.
The value of this new sysctl can be different per namespace. We can then
restrict the usage of MPTCP to the selected NS. In case of serious
issues with MPTCP, administrators can now easily turn MPTCP off.
Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the current sendmsg() lands on the same subflow we used last, we
can try to collapse the data.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With the previous patch in place, the msk can detect which subflow
has the current map with a simple walk, let's update the main
loop to always select the 'current' subflow. The exit conditions now
closely mirror tcp_recvmsg() to get expected timeout and signal
behavior.
Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add new SEND_SPACE flag to indicate that a subflow has enough space to
accept more data for transmission.
It gets cleared at the end of mptcp_sendmsg() in case ssk has run
below the free watermark.
It is (re-set) from the wspace callback.
This allows us to use msk->flags to determine the poll mask.
Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Parses incoming DSS options and populates outgoing MPTCP ACK
fields. MPTCP fields are parsed from the TCP option header and placed in
an skb extension, allowing the upper MPTCP layer to access MPTCP
options after the skb has gone through the TCP stack.
The subflow implements its own data_ready() ops, which ensures that the
pending data is in sequence - according to MPTCP seq number - dropping
out-of-seq skbs. The DATA_READY bit flag is set if this is the case.
This allows the MPTCP socket layer to determine if more data is
available without having to consult the individual subflows.
It additionally validates the current mapping and propagates EoF events
to the connection socket.
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Per-packet metadata required to write the MPTCP DSS option is written to
the skb_ext area. One write to the socket may contain more than one
packet of data, which is copied to page fragments and mapped in to MPTCP
DSS segments with size determined by the available page fragments and
the maximum mapping length allowed by the MPTCP specification. If
do_tcp_sendpages() splits a DSS segment in to multiple skbs, that's ok -
the later skbs can either have duplicated DSS mapping information or
none at all, and the receiver can handle that.
The current implementation uses the subflow frag cache and tcp
sendpages to avoid excessive code duplication. More work is required to
ensure that it works correctly under memory pressure and to support
MPTCP-level retransmissions.
The MPTCP DSS checksum is not yet implemented.
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
set/getsockopt behaviour with multiple subflows is undefined.
Therefore, for now, we return -EOPNOTSUPP unless we're in fallback mode.
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: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Call shutdown on all subflows in use on the given socket, or on the
fallback socket.
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Generate the local keys, IDSN, and token when creating a new socket.
Introduce the token tree to track all tokens in use using a radix tree
with the MPTCP token itself as the index.
Override the rebuild_header callback in inet_connection_sock_af_ops for
creating the local key on a new outgoing connection.
Override the init_req callback of tcp_request_sock_ops for creating the
local key on a new incoming connection.
Will be used to obtain the MPTCP parent socket to handle incoming joins.
Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
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: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add subflow_request_sock type that extends tcp_request_sock
and add an is_mptcp flag to tcp_request_sock distinguish them.
Override the listen() and accept() methods of the MPTCP
socket proto_ops so they may act on the subflow socket.
Override the conn_request() and syn_recv_sock() handlers
in the inet_connection_sock to handle incoming MPTCP
SYNs and the ACK to the response SYN.
Add handling in tcp_output.c to add MP_CAPABLE to an outgoing
SYN-ACK response for a subflow_request_sock.
Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add hooks to tcp_output.c to add MP_CAPABLE to an outgoing SYN request,
to capture the MP_CAPABLE in the received SYN-ACK, to add MP_CAPABLE to
the final ACK of the three-way handshake.
Use the .sk_rx_dst_set() handler in the subflow proto to capture when the
responding SYN-ACK is received and notify the MPTCP connection layer.
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use ULP to associate a subflow_context structure with each TCP subflow
socket. Creating these sockets requires new bind and connect functions
to make sure ULP is set up immediately when the subflow sockets are
created.
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
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: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implements the infrastructure for MPTCP sockets.
MPTCP sockets open one in-kernel TCP socket per subflow. These subflow
sockets are only managed by the MPTCP socket that owns them and are not
visible from userspace. This commit allows a userspace program to open
an MPTCP socket with:
sock = socket(AF_INET, SOCK_STREAM, IPPROTO_MPTCP);
The resulting socket is simply a wrapper around a single regular TCP
socket, without any of the MPTCP protocol implemented over the wire.
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
