Commit graph

109 commits

Author SHA1 Message Date
Paolo Abeni 64b9cea7a0 mptcp: fix spurious retransmissions
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>
2021-02-11 18:30:54 -08:00
Paolo Abeni 15cc104533 mptcp: deliver ssk errors to msk
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>
2021-02-11 18:30:54 -08:00
Paolo Abeni 219d04992b mptcp: push pending frames when subflow has free space
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>
2020-12-17 10:24:47 -08:00
Florian Westphal 50c504a20a mptcp: parse and act on incoming FASTCLOSE option
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>
2020-12-14 17:30:06 -08:00
Geliang Tang ba34c3de71 mptcp: use MPTCPOPT_HMAC_LEN macro
Use the macro MPTCPOPT_HMAC_LEN instead of a constant in struct
mptcp_options_received.

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>
2020-12-14 17:30:06 -08:00
Paolo Abeni 5b950ff433 mptcp: link MPC subflow into msk only after accept
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>
2020-12-09 19:31:58 -08:00
Geliang Tang 13ad9f01a2 mptcp: rename add_addr_signal and mptcp_add_addr_status
Since the RM_ADDR signal had been reused with add_addr_signal, it's not
suitable to call it add_addr_signal or mptcp_add_addr_status. So this
patch renamed add_addr_signal to addr_signal, and renamed
mptcp_add_addr_status to mptcp_addr_signal_status.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-09 19:02:16 -08:00
Geliang Tang 42842a425a mptcp: drop rm_addr_signal flag
This patch reused add_addr_signal for the RM_ADDR announcing signal, by
defining a new ADD_ADDR status named MPTCP_RM_ADDR_SIGNAL. Then the flag
rm_addr_signal in PM could be dropped.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-09 19:02:15 -08:00
Geliang Tang 0f5c9e3f07 mptcp: add port parameter for mptcp_pm_announce_addr
This patch added a new parameter 'port' for mptcp_pm_announce_addr. If
this parameter is true, we set the MPTCP_ADD_ADDR_PORT bit of the
add_addr_signal. That means the announced address is added with a port
number.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-09 19:02:15 -08:00
Geliang Tang 4a2777a834 mptcp: add the outgoing ADD_ADDR port support
This patch added a new add_addr_signal type named MPTCP_ADD_ADDR_PORT,
to identify it is an address with port to be added.

It also added a new parameter 'port' for both mptcp_add_addr_len and
mptcp_pm_add_addr_signal.

In mptcp_established_options_add_addr, we check whether the announced
address is added with port. If it is, we put this port number to
mptcp_out_options's port field.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-09 19:02:15 -08:00
Geliang Tang 2ec72faec8 mptcp: use adding up size to get ADD_ADDR length
This patch uses adding up size to get the ADD_ADDR suboption length rather
than returning the ADD_ADDR size constants.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-09 19:02:15 -08:00
Geliang Tang 22fb85ffae mptcp: add port support for ADD_ADDR suboption writing
In rfc8684, the length of ADD_ADDR suboption with IPv4 address and port
is 18 octets, but mptcp_write_options is 32-bit aligned, so we need to
pad it to 20 octets. All the other port related option lengths need to
be added up 2 octets similarly.

This patch added a new field 'port' in mptcp_out_options. When this
field is set with a port number, we need to add up 4 octets for the
ADD_ADDR suboption, and put the port number into the suboption.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-09 19:02:15 -08:00
Paolo Abeni 6e628cd3a8 mptcp: use mptcp release_cb for delayed tasks
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>
2020-11-30 17:55:23 -08:00
Paolo Abeni 7439d687b7 mptcp: avoid a few atomic ops in the rx path
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>
2020-11-30 17:55:23 -08:00
Paolo Abeni 724cfd2ee8 mptcp: allocate TX skbs in msk context
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>
2020-11-30 17:55:23 -08:00
Paolo Abeni 879526030c mptcp: protect the rx path with the msk socket spinlock
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>
2020-11-30 17:55:23 -08:00
Paolo Abeni e93da92896 mptcp: implement wmem reservation
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>
2020-11-30 17:55:23 -08:00
Paolo Abeni ad80b0fc6e mptcp: open code mptcp variant for lock_sock
This allows invoking an additional callback under the
socket spin lock.

Will be used by the next patches to avoid additional
spin lock contention.

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>
2020-11-30 17:55:23 -08:00
Paolo Abeni ea4ca586b1 mptcp: refine MPTCP-level ack scheduling
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>
2020-11-20 15:33:25 -08:00
Florian Westphal fa3fe2b150 mptcp: track window announced to peer
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>
2020-11-20 15:33:25 -08:00
Geliang Tang 84dfe3677a mptcp: send out dedicated ADD_ADDR packet
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>
2020-11-20 15:33:25 -08:00
Geliang Tang d91d322a72 mptcp: change add_addr_signal type
This patch changed the 'add_addr_signal' type from bool to char, so that
we could encode the addr type there.

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>
2020-11-20 15:33:25 -08:00
Paolo Abeni 0397c6d85f mptcp: keep unaccepted MPC subflow into join list
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>
2020-11-20 15:33:25 -08:00
Paolo Abeni b2771d2419 mptcp: drop WORKER_RUNNING status bit
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>
2020-11-20 15:33:24 -08:00
Florian Westphal 6f8a612a33 mptcp: keep track of advertised windows right edge
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>
2020-11-16 10:46:07 -08:00
Florian Westphal 8edf08649e mptcp: rework poll+nospace handling
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>
2020-11-16 10:46:07 -08:00
Paolo Abeni e16163b6e2 mptcp: refactor shutdown and close
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>
2020-11-16 10:46:07 -08:00
Paolo Abeni eaa2ffabfc mptcp: introduce MPTCP snd_nxt
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>
2020-11-16 10:46:07 -08:00
Paolo Abeni f0e6a4cf11 mptcp: add accounting for pending data
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>
2020-11-16 10:46:06 -08:00
Paolo Abeni ba8f48f7a4 mptcp: introduce mptcp_schedule_work
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>
2020-11-16 10:46:06 -08:00
Geliang Tang 93f323b9cc mptcp: add a new sysctl add_addr_timeout
This patch added a new sysctl, named add_addr_timeout, to control the
timeout value (in seconds) of the ADD_ADDR retransmission.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
2020-11-04 17:45:53 -08:00
Jakub Kicinski 2295cddf99 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
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>
2020-10-15 12:43:21 -07:00
Paolo Abeni 0e4f35d788 mptcp: subflows garbage collection
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>
2020-10-10 11:04:53 -07:00
Paolo Abeni d582484726 mptcp: fix fallback for MP_JOIN subflows
Additional/MP_JOIN subflows that do not pass some initial handshake
tests currently causes fallback to TCP. That is an RFC violation:
we should instead reset the subflow and leave the the msk untouched.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/91
Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
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>
2020-10-10 11:04:53 -07:00
Davide Caratti 37198e93ce net: mptcp: make DACK4/DACK8 usage consistent among all subflows
using packetdrill it's possible to observe the same MPTCP DSN being acked
by different subflows with DACK4 and DACK8. This is in contrast with what
specified in RFC8684 §3.3.2: if an MPTCP endpoint transmits a 64-bit wide
DSN, it MUST be acknowledged with a 64-bit wide DACK. Fix 'use_64bit_ack'
variable to make it a property of MPTCP sockets, not TCP subflows.

Fixes: a0c1d0eafd ("mptcp: Use 32-bit DATA_ACK when possible")
Acked-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: Jakub Kicinski <kuba@kernel.org>
2020-10-09 08:25:48 -07:00
David S. Miller 8b0308fe31 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/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>
2020-10-05 18:40:01 -07:00
Matthieu Baerts 456afe01b1 mptcp: ADD_ADDRs with echo bit are smaller
The MPTCP ADD_ADDR suboption with echo-flag=1 has no HMAC, the size is
smaller than the one initially sent without echo-flag=1. We then need to
use the correct size everywhere when we need this echo bit.

Before this patch, the wrong size was reserved but the correct amount of
bytes were written (and read): the remaining bytes contained garbage.

Fixes: 6a6c05a8b0 ("mptcp: send out ADD_ADDR with echo flag")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/95
Reported-and-tested-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03 17:36:37 -07:00
Mat Martineau 1a49b2c2a5 mptcp: Handle incoming 32-bit DATA_FIN values
The peer may send a DATA_FIN mapping with either a 32-bit or 64-bit
sequence number. When a 32-bit sequence number is received for the
DATA_FIN, it must be expanded to 64 bits before comparing it to the
last acked sequence number. This expansion was missing.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/93
Fixes: 3721b9b646 ("mptcp: Track received DATA_FIN sequence number and add related helpers")
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-29 18:15:46 -07:00
Geliang Tang 00cfd77b90 mptcp: retransmit ADD_ADDR when timeout
This patch implemented the retransmition of ADD_ADDR when no ADD_ADDR echo
is received. It added a timer with the announced address. When timeout
occurs, ADD_ADDR will be retransmitted.

Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Suggested-by: Paolo Abeni <pabeni@redhat.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>
2020-09-24 19:58:34 -07:00
Geliang Tang 5c8c164095 mptcp: add mptcp_destroy_common helper
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>
2020-09-24 19:58:34 -07:00
Geliang Tang 0ee4261a36 mptcp: implement mptcp_pm_remove_subflow
This patch implemented the local subflow removing function,
mptcp_pm_remove_subflow, it simply called mptcp_pm_nl_rm_subflow_received
under the PM spin lock.

We use mptcp_pm_remove_subflow to remove a local subflow, so change it's
argument from remote_id to local_id.

We check subflow->local_id in mptcp_pm_nl_rm_subflow_received to remove
a subflow.

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>
2020-09-24 19:58:34 -07:00
Geliang Tang b6c0838086 mptcp: remove addr and subflow in PM netlink
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>
2020-09-24 19:58:33 -07:00
Geliang Tang 6a6c05a8b0 mptcp: send out ADD_ADDR with echo flag
When the ADD_ADDR suboption has been received, we need to send out the same
ADD_ADDR suboption with echo-flag=1, and no HMAC.

Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:58:33 -07:00
Geliang Tang d0876b2284 mptcp: add the incoming RM_ADDR support
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>
2020-09-24 19:58:33 -07:00
Geliang Tang 5cb104ae55 mptcp: add the outgoing RM_ADDR support
This patch added a new signal named rm_addr_signal in PM. On outgoing path,
we called mptcp_pm_should_rm_signal to check if rm_addr_signal has been
set. If it has been, we sent out the RM_ADDR option.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
2020-09-24 19:58:33 -07:00
Geliang Tang f643b8032e mptcp: rename addr_signal and the related functions
This patch renamed addr_signal and the related functions with the explicit
word "add".

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
2020-09-24 19:58:33 -07:00
Paolo Abeni d5f49190de mptcp: allow picking different xmit subflows
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>
2020-09-14 13:28:02 -07:00
Paolo Abeni ef0da3b8a2 mptcp: move address attribute into mptcp_addr_info
So that can be accessed easily from the subflow creation
helper. No functional change intended.

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>
2020-09-14 13:28:02 -07:00
Paolo Abeni 04e4cd4f7c mptcp: cleanup mptcp_subflow_discard_data()
There is no need to use the tcp_read_sock(), we can
simply drop the skb. Additionally try to look at the
next buffer for in order data.

This both simplifies the code and avoid unneeded indirect
calls.

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>
2020-09-14 13:28:02 -07:00
Paolo Abeni ab174ad8ef mptcp: move ooo skbs into msk out of order queue.
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>
2020-09-14 13:28:02 -07:00