Commit Graph

217 Commits

Author SHA1 Message Date
Mat Martineau ae66fb2ba6 mptcp: Do TCP fallback on early DSS checksum failure
RFC 8684 section 3.7 describes several opportunities for a MPTCP
connection to "fall back" to regular TCP early in the connection
process, before it has been confirmed that MPTCP options can be
successfully propagated on all SYN, SYN/ACK, and data packets. If a peer
acknowledges the first received data packet with a regular TCP header
(no MPTCP options), fallback is allowed.

If the recipient of that first data packet finds a MPTCP DSS checksum
error, this provides an opportunity to fail gracefully with a TCP
fallback rather than resetting the connection (as might happen if a
checksum failure were detected later).

This commit modifies the checksum failure code to attempt fallback on
the initial subflow of a MPTCP connection, only if it's a failure in the
first data mapping. In cases where the peer initiates the connection,
requests checksums, is the first to send data, and the peer is sending
incorrect checksums (see
https://github.com/multipath-tcp/mptcp_net-next/issues/275), this allows
the connection to proceed as TCP rather than reset.

Fixes: dd8bcd1768 ("mptcp: validate the data checksum")
Acked-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>
2022-05-18 13:05:42 +01:00
Paolo Abeni ba2c89e0ea mptcp: fix checksum byte order
The MPTCP code typecasts the checksum value to u16 and
then converts it to big endian while storing the value into
the MPTCP option.

As a result, the wire encoding for little endian host is
wrong, and that causes interoperabilty interoperability
issues with other implementation or host with different endianness.

Address the issue writing in the packet the unmodified __sum16 value.

MPTCP checksum is disabled by default, interoperating with systems
with bad mptcp-level csum encoding should cause fallback to TCP.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/275
Fixes: c5b39e26d0 ("mptcp: send out checksum for DSS")
Fixes: 390b95a5fb ("mptcp: receive checksum for DSS")
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>
2022-05-18 13:05:42 +01:00
Paolo Abeni 95d6865178 mptcp: fix subflow accounting on close
If the PM closes a fully established MPJ subflow or the subflow
creation errors out in it's early stage the subflows counter is
not bumped accordingly.

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

Fixes: a88c9e4969 ("mptcp: do not block subflows creation on errors")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-13 17:04:30 -07:00
Paolo Abeni 4cf86ae84c mptcp: strict local address ID selection
The address ID selection for MPJ subflows created in response
to incoming ADD_ADDR option is currently unreliable: it happens
at MPJ socket creation time, when the local address could be
unknown.

Additionally, if the no local endpoint is available for the local
address, a new dummy endpoint is created, confusing the user-land.

This change refactor the code to move the address ID selection inside
the rebuild_header() helper, when the local address eventually
selected by the route lookup is finally known. If the address used
is not mapped by any endpoint - and thus can't be advertised/removed
pick the id 0 instead of allocate a new endpoint.

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>
2022-03-08 22:06:12 -08:00
Florian Westphal 952382c648 mptcp: don't save tcp data_ready and write space callbacks
Assign the helpers directly rather than save/restore in the context
structure.

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>
2022-02-16 20:52:06 -08:00
Paolo Abeni 90d9308821 mptcp: constify a bunch of of helpers
A few pm-related helpers don't touch arguments which lacking
the const modifier, let's constify them.

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>
2022-02-16 20:52:05 -08:00
Geliang Tang af7939f390 mptcp: drop port parameter of mptcp_pm_add_addr_signal
Drop the port parameter of mptcp_pm_add_addr_signal() and reflect it to
avoid passing too many parameters.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-16 20:52:05 -08:00
Geliang Tang 0799e21b5a mptcp: drop unused sk in mptcp_get_options
The parameter 'sk' became useless since the code using it was dropped
from mptcp_get_options() in the commit 8d548ea1dd ("mptcp: do not set
unconditionally csum_reqd on incoming opt"). Let's drop it.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-16 20:52:04 -08:00
Kees Cook 63ec72bd58 mptcp: Use struct_group() to avoid cross-field memset()
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() to capture the fields to be reset, so that memset()
can be appropriately bounds-checked by the compiler.

Cc: Matthieu Baerts <matthieu.baerts@tessares.net>
Cc: mptcp@lists.linux.dev
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Link: https://lore.kernel.org/r/20220121073935.1154263-1-keescook@chromium.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-21 19:26:03 -08:00
Geliang Tang c312ee2191 mptcp: change the parameter of __mptcp_make_csum
This patch changed the type of the last parameter of __mptcp_make_csum()
from __sum16 to __wsum. And export this function in protocol.h.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-07 19:00:44 -08:00
Paolo Abeni e9d09baca6 mptcp: avoid atomic bit manipulation when possible
Currently the msk->flags bitmask carries both state for the
mptcp_release_cb() - mostly touched under the mptcp data lock
- and others state info touched even outside such lock scope.

As a consequence, msk->flags is always manipulated with
atomic operations.

This change splits such bitmask in two separate fields, so
that we use plain bit operations when touching the
cb-related info.

The MPTCP_PUSH_PENDING bit needs additional care, as it is the
only CB related field currently accessed either under the mptcp
data lock or the mptcp socket lock.
Let's add another mask just for such bit's sake.

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>
2022-01-07 11:27:07 +00:00
Paolo Abeni 3e5014909b mptcp: cleanup MPJ subflow list handling
We can simplify the join list handling leveraging the
mptcp_release_cb(): if we can acquire the msk socket
lock at mptcp_finish_join time, move the new subflow
directly into the conn_list, otherwise place it on join_list and
let the release_cb process such list.

Since pending MPJ connection are now always processed
in a timely way, we can avoid flushing the join list
every time we have to process all the current subflows.

Additionally we can now use the mptcp data lock to protect
the join_list, removing the additional spin lock.

Finally, the MPJ handshake is now always finalized under the
msk socket lock, we can drop the additional synchronization
between mptcp_finish_join() and mptcp_close().

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>
2022-01-07 11:27:07 +00:00
Paolo Abeni a88c9e4969 mptcp: do not block subflows creation on errors
If the MPTCP configuration allows for multiple subflows
creation, and the first additional subflows never reach
the fully established status - e.g. due to packets drop or
reset - the in kernel path manager do not move to the
next subflow.

This patch introduces a new PM helper to cope with MPJ
subflow creation failure and delay and hook it where appropriate.

Such helper triggers additional subflow creation, as needed
and updates the PM subflow counter, if the current one is
closing.

Additionally start all the needed additional subflows
as soon as the MPTCP socket is fully established, so we don't
have to cope with slow MPJ handshake blocking the next subflow
creation.

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>
2022-01-07 11:27:07 +00:00
Paolo Abeni 86e39e0448 mptcp: keep track of local endpoint still available for each msk
Include into the path manager status a bitmap tracking the list
of local endpoints still available - not yet used - for the
relevant mptcp socket.

Keep such map updated at endpoint creation/deletion time, so
that we can easily skip already used endpoint at local address
selection time.

The endpoint used by the initial subflow is lazyly accounted at
subflow creation time: the usage bitmap is be up2date before
endpoint selection and we avoid such unneeded task in some relevant
scenarios - e.g. busy servers accepting incoming subflows but
not creating any additional ones nor annuncing additional addresses.

Overall this allows for fair local endpoints usage in case of
subflow failure.

As a side effect, this patch also enforces that each endpoint
is used at most once for each mptcp connection.

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>
2022-01-07 11:27:07 +00:00
Paolo Abeni 71ba088ce0 mptcp: cleanup accept and poll
After the previous patch,  msk->subflow will never be deleted during
the whole msk lifetime. We don't need anymore to acquire references to
it in mptcp_stream_accept() and we can use the listener subflow accept
queue to simplify mptcp_poll() for listener socket.

Overall this removes a lock pair and 4 more atomic operations per
accept().

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>
2022-01-07 11:27:07 +00:00
Paolo Abeni b29fcfb54c mptcp: full disconnect implementation
The current mptcp_disconnect() implementation lacks several
steps, we additionally need to reset the msk socket state
and flush the subflow list.

Factor out the needed helper to avoid code duplication.

Additionally ensure that the initial subflow is disposed
only after mptcp_close(), just reset it at disconnect time.

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>
2022-01-07 11:27:06 +00:00
Paolo Abeni f284c0c773 mptcp: implement fastclose xmit path
Allow the MPTCP xmit path to add MP_FASTCLOSE suboption
on RST egress packets.

Additionally reorder related options writing to reduce
the number of conditionals required in the fast path.

Co-developed-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-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: David S. Miller <davem@davemloft.net>
2022-01-07 11:27:06 +00:00
Paolo Abeni 3ce0852c86 mptcp: enforce HoL-blocking estimation
The MPTCP packet scheduler has sub-optimal behavior with asymmetric
subflows: if the faster subflow-level cwin is closed, the packet
scheduler can enqueue "too much" data on a slower subflow.

When all the data on the faster subflow is acked, if the mptcp-level
cwin is closed, and link utilization becomes suboptimal.

The solution is implementing blest-like[1] HoL-blocking estimation,
transmitting only on the subflow with the shorter estimated time to
flush the queued memory. If such subflows cwin is closed, we wait
even if other subflows are available.

This is quite simpler than the original blest implementation, as we
leverage the pacing rate provided by the TCP socket. To get a more
accurate estimation for the subflow linger-time, we maintain a
per-subflow weighted average of such info.

Additionally drop magic numbers usage in favor of newly defined
macros and use more meaningful names for status variable.

[1] http://dl.ifip.org/db/conf/networking/networking2016/1570234725.pdf

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/137
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>
2021-12-17 19:27:04 -08:00
Maxim Galaganov 4f6e14bd19 mptcp: support TCP_CORK and TCP_NODELAY
First, add cork and nodelay fields to the mptcp_sock structure
so they can be used in sync_socket_options(), and fill them on setsockopt
while holding the msk socket lock.

Then, on setsockopt set proper tcp_sk(ssk)->nonagle values for subflows
by calling __tcp_sock_set_cork() or __tcp_sock_set_nodelay() on the ssk
while holding the ssk socket lock.

tcp_push_pending_frames() will be invoked on the ssk if a cork was cleared
or nodelay was set. Also set MPTCP_PUSH_PENDING bit by calling
mptcp_check_and_set_pending(). This will lead to __mptcp_push_pending()
being called inside mptcp_release_cb() with new tcp_sk(ssk)->nonagle.

Also add getsockopt support for TCP_CORK and TCP_NODELAY.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Maxim Galaganov <max@internet.ru>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-07 11:36:31 -08:00
Maxim Galaganov 8b38217a2a mptcp: expose mptcp_check_and_set_pending
Expose the mptcp_check_and_set_pending() function for use inside MPTCP
sockopt code. The next patch will call it when TCP_CORK is cleared or
TCP_NODELAY is set on the MPTCP socket in order to push pending data
from mptcp_release_cb().

Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Maxim Galaganov <max@internet.ru>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-07 11:36:31 -08:00
Florian Westphal 2c9e77659a mptcp: add TCP_INQ cmsg support
Support the TCP_INQ setsockopt.

This is a boolean that tells recvmsg path to include the remaining
in-sequence bytes in the cmsg data.

v2: do not use CB(skb)->offset, increment map_seq instead (Paolo Abeni)
v3: adjust CB(skb)->map_seq when taking skb from ofo queue (Paolo Abeni)

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/224
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>
2021-12-07 11:36:29 -08:00
Paolo Abeni bcd9773431 mptcp: use delegate action to schedule 3rd ack retrans
Scheduling a delack in mptcp_established_options_mp() is
not a good idea: such function is called by tcp_send_ack() and
the pending delayed ack will be cleared shortly after by the
tcp_event_ack_sent() call in __tcp_transmit_skb().

Instead use the mptcp delegated action infrastructure to
schedule the delayed ack after the current bh processing completes.

Additionally moves the schedule_3rdack_retransmission() helper
into protocol.c to avoid making it visible in a different compilation
unit.

Fixes: ec3edaa7ca ("mptcp: Add handling of outgoing MP_JOIN requests")
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>
2021-11-20 14:24:00 +00:00
Paolo Abeni 6511882cdd mptcp: allocate fwd memory separately on the rx and tx path
All the mptcp receive path is protected by the msk socket
spinlock. As consequences, the tx path has to play a few tricks to
allocate the forward memory without acquiring the spinlock multiple
times, making the overall TX path quite complex.

This patch tries to clean-up a bit the tx path, using completely
separated fwd memory allocation, for the rx and the tx path.

The forward memory allocated in the rx path is now accounted in
msk->rmem_fwd_alloc and is (still) protected by the msk socket spinlock.

To cope with the above we provide a few MPTCP-specific variants for
the helpers to charge, uncharge, reclaim and free the forward memory
in the receive path.

msk->sk_forward_alloc now accounts only the forward memory for the tx
path, we can use the plain core sock helper to manipulate it and drop
quite a bit of complexity.

On memory pressure, both rx and tx fwd memories are reclaimed.

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>
2021-10-27 18:20:29 -07:00
Mat Martineau 3828c51472 mptcp: Make mptcp_pm_nl_mp_prio_send_ack() static
This function is only used within pm_netlink.c now.

Fixes: 067065422f ("mptcp: add the outgoing MP_PRIO support")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-16 08:46:08 +01:00
Jakub Kicinski dd9a887b35 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/phy/bcm7xxx.c
  d88fd1b546 ("net: phy: bcm7xxx: Fixed indirect MMD operations")
  f68d08c437 ("net: phy: bcm7xxx: Add EPHY entry for 72165")

net/sched/sch_api.c
  b193e15ac6 ("net: prevent user from passing illegal stab size")
  69508d4333 ("net_sched: Use struct_size() and flex_array_size() helpers")

Both cases trivial - adjacent code additions.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-30 14:49:21 -07:00
Florian Westphal 9e65b6a5aa mptcp: remove tx_pending_data
The update on recovery is not correct.

msk->tx_pending_data += msk->snd_nxt - rtx_head->data_seq;

will update tx_pending_data multiple times when a subflow is declared
stale while earlier recovery is still in progress.
This means that tx_pending_data will still be positive even after
all data as has been transmitted.

Rather than fix it, remove this field: there are no consumers.
The outstanding data byte count can be computed either via

 "msk->write_seq - rtx_head->data_seq" or
 "msk->write_seq - msk->snd_una".

The latter is more recent/accurate estimate as rtx_head adjustment
is deferred until mptcp lock can be acquired.

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: David S. Miller <davem@davemloft.net>
2021-09-25 11:36:51 +01:00
Florian Westphal ea1300b9df mptcp: don't return sockets in foreign netns
mptcp_token_get_sock() may return a mptcp socket that is in
a different net namespace than the socket that received the token value.

The mptcp syncookie code path had an explicit check for this,
this moves the test into mptcp_token_get_sock() function.

Eventually token.c should be converted to pernet storage, but
such change is not suitable for net tree.

Fixes: 2c5ebd001d ("mptcp: refactor token container")
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>
2021-09-24 10:51:36 +01:00
Mat Martineau 340fa6667a mptcp: Only send extra TCP acks in eligible socket states
Recent changes exposed a bug where specifically-timed requests to the
path manager netlink API could trigger a divide-by-zero in
__tcp_select_window(), as syzkaller does:

divide error: 0000 [#1] SMP KASAN NOPTI
CPU: 0 PID: 9667 Comm: syz-executor.0 Not tainted 5.14.0-rc6+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:__tcp_select_window+0x509/0xa60 net/ipv4/tcp_output.c:3016
Code: 44 89 ff e8 c9 29 e9 fd 45 39 e7 0f 8d 20 ff ff ff e8 db 28 e9 fd 44 89 e3 e9 13 ff ff ff e8 ce 28 e9 fd 44 89 e0 44 89 e3 99 <f7> 7c 24 04 29 d3 e9 fc fe ff ff e8 b7 28 e9 fd 44 89 f1 48 89 ea
RSP: 0018:ffff888031ccf020 EFLAGS: 00010216
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000040000
RDX: 0000000000000000 RSI: ffff88811532c080 RDI: 0000000000000002
RBP: 0000000000000000 R08: ffffffff835807c2 R09: 0000000000000000
R10: 0000000000000004 R11: ffffed1020b92441 R12: 0000000000000000
R13: 1ffff11006399e08 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fa4c8344700(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f424000 CR3: 000000003e4e2003 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
 tcp_select_window net/ipv4/tcp_output.c:264 [inline]
 __tcp_transmit_skb+0xc00/0x37a0 net/ipv4/tcp_output.c:1351
 __tcp_send_ack.part.0+0x3ec/0x760 net/ipv4/tcp_output.c:3972
 __tcp_send_ack net/ipv4/tcp_output.c:3978 [inline]
 tcp_send_ack+0x7d/0xa0 net/ipv4/tcp_output.c:3978
 mptcp_pm_nl_addr_send_ack+0x1ab/0x380 net/mptcp/pm_netlink.c:654
 mptcp_pm_remove_addr+0x161/0x200 net/mptcp/pm.c:58
 mptcp_nl_remove_id_zero_address+0x197/0x460 net/mptcp/pm_netlink.c:1328
 mptcp_nl_cmd_del_addr+0x98b/0xd40 net/mptcp/pm_netlink.c:1359
 genl_family_rcv_msg_doit.isra.0+0x225/0x340 net/netlink/genetlink.c:731
 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
 genl_rcv_msg+0x341/0x5b0 net/netlink/genetlink.c:792
 netlink_rcv_skb+0x148/0x430 net/netlink/af_netlink.c:2504
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x537/0x750 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x846/0xd80 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg+0x14e/0x190 net/socket.c:724
 ____sys_sendmsg+0x709/0x870 net/socket.c:2403
 ___sys_sendmsg+0xff/0x170 net/socket.c:2457
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

mptcp_pm_nl_addr_send_ack() was attempting to send a TCP ACK on the
first subflow in the MPTCP socket's connection list without validating
that the subflow was in a suitable connection state. To address this,
always validate subflow state when sending extra ACKs on subflows
for address advertisement or subflow priority change.

Fixes: 84dfe3677a ("mptcp: send out dedicated ADD_ADDR packet")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/229
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>
Acked-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-03 11:49:30 +01:00
Wan Jiabing 780aa1209f mptcp: Fix duplicated argument in protocol.h
Fix the following coccicheck warning:
./net/mptcp/protocol.h:36:50-73: duplicated argument to & or |

The OPTION_MPTCP_MPJ_SYNACK here is duplicate.
Here should be OPTION_MPTCP_MPJ_ACK.

Fixes: 74c7dfbee3 ("mptcp: consolidate in_opt sub-options fields in a bitmask")
Signed-off-by: Wan Jiabing <wanjiabing@vivo.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>
2021-09-01 12:51:48 +01:00
Paolo Abeni 74c7dfbee3 mptcp: consolidate in_opt sub-options fields in a bitmask
This makes input options processing more consistent with
output ones and will simplify the next patch.

Also avoid clearing the suboption field after processing
it, since it's not needed.

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>
2021-08-27 09:45:07 +01:00
Paolo Abeni a086aebae0 mptcp: better binary layout for mptcp_options_received
This change reorder the mptcp_options_received fields
to shrink the structure a bit and to ensure the most
frequently used fields are all in the first cacheline.

Sub-opt specific flags are moved out of the suboptions area,
and we must now explicitly set them when the relevant
suboption is parsed.

There is a notable exception: 'csum_reqd' is used by both DSS
and MPC suboptions, and keeping such field in the suboptions
flag area will simplfy the next patch.

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>
2021-08-27 09:45:07 +01:00
Geliang Tang 478d770008 mptcp: send out MP_FAIL when data checksum fails
When a bad checksum is detected, set the send_mp_fail flag to send out
the MP_FAIL option.

Add a new function mptcp_has_another_subflow() to check whether there's
only a single subflow.

When multiple subflows are in use, close the affected subflow with a RST
that includes an MP_FAIL option and discard the data with the bad
checksum.

Set the sk_state of the subsocket to TCP_CLOSE, then the flag
MPTCP_WORK_CLOSE_SUBFLOW will be set in subflow_sched_work_if_closed,
and the subflow will be closed.

When a single subfow is in use, temporarily handled by sending MP_FAIL
with a RST too.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25 11:02:35 +01:00
Geliang Tang 5580d41b75 mptcp: MP_FAIL suboption receiving
This patch added handling for receiving MP_FAIL suboption.

Add a new members mp_fail and fail_seq in struct mptcp_options_received.
When MP_FAIL suboption is received, set mp_fail to 1 and save the sequence
number to fail_seq.

Then invoke mptcp_pm_mp_fail_received to deal with the MP_FAIL suboption.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25 11:02:34 +01:00
Geliang Tang c25aeb4e09 mptcp: MP_FAIL suboption sending
This patch added the MP_FAIL suboption sending support.

Add a new flag named send_mp_fail in struct mptcp_subflow_context. If
this flag is set, send out MP_FAIL suboption.

Add a new member fail_seq in struct mptcp_out_options to save the data
sequence number to put into the MP_FAIL suboption.

An MP_FAIL option could be included in a RST or on the subflow-level
ACK.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25 11:02:34 +01:00
Paolo Abeni 1bff1e43a3 mptcp: optimize out option generation
Currently we have several protocol constraints on MPTCP options
generation (e.g. MPC and MPJ subopt are mutually exclusive)
and some additional ones required by our implementation
(e.g. almost all ADD_ADDR variant are mutually exclusive with
everything else).

We can leverage the above to optimize the out option generation:
we check DSS/MPC/MPJ presence in a mutually exclusive way,
avoiding many unneeded conditionals in the common cases.

Additionally extend the existing constraints on ADD_ADDR opt on
all subvariants, so that it becomes fully mutually exclusive with
the above and we can skip another conditional statement for the
common case.

This change is also needed by the next patch.

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>
2021-08-25 11:02:34 +01:00
Yonglong Li c233ef1390 mptcp: remove MPTCP_ADD_ADDR_IPV6 and MPTCP_ADD_ADDR_PORT
MPTCP_ADD_ADDR_IPV6 and MPTCP_ADD_ADDR_PORT are not necessary, we can get
these info from pm.local or pm.remote.

Drop mptcp_pm_should_add_signal_ipv6 and mptcp_pm_should_add_signal_port
too.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24 09:28:29 +01:00
Yonglong Li f462a44638 mptcp: build ADD_ADDR/echo-ADD_ADDR option according pm.add_signal
According to the MPTCP_ADD_ADDR_SIGNAL or MPTCP_ADD_ADDR_ECHO flag, build
the ADD_ADDR/ADD_ADDR_ECHO option.

In mptcp_pm_add_addr_signal(), use opts->addr to save the announced
ADD_ADDR or ADD_ADDR_ECHO address.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24 09:28:28 +01:00
Yonglong Li 18fc1a922e mptcp: make MPTCP_ADD_ADDR_SIGNAL and MPTCP_ADD_ADDR_ECHO separate
Use MPTCP_ADD_ADDR_SIGNAL only for the action of sending ADD_ADDR, and
use MPTCP_ADD_ADDR_ECHO only for the action of sending ADD_ADDR echo.

Use msk->pm.local to save the announced ADD_ADDR address only, and reuse
msk->pm.remote to save the announced ADD_ADDR_ECHO address.

To prepare for the next patch.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24 09:28:28 +01:00
Yonglong Li 1f5e9e2f5f mptcp: move drop_other_suboptions check under pm lock
This patch moved the drop_other_suboptions check from
mptcp_established_options_add_addr() into mptcp_pm_add_addr_signal(), do
it under the PM lock to avoid the race between this check and
mptcp_pm_add_addr_signal().

For this, added a new parameter for mptcp_pm_add_addr_signal() to get
the drop_other_suboptions value. And drop the other suboptions after the
option length check if drop_other_suboptions is true.

Additionally, always drop the other suboption for TCP pure ack:
that makes both the code simpler and the MPTCP behaviour more
consistent.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24 09:28:28 +01:00
Geliang Tang ee285257a9 mptcp: drop flags and ifindex arguments
This patch added a new helper mptcp_pm_get_flags_and_ifindex_by_id(),
and used it in __mptcp_subflow_connect() to get the flags and ifindex
values.

Then the two arguments flags and ifindex of __mptcp_subflow_connect()
can be dropped.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-18 10:10:01 +01:00
Paolo Abeni ff5a0b421c mptcp: faster active backup recovery
The msk can use backup subflows to transmit in-sequence data
only if there are no other active subflow. On active backup
scenario, the MPTCP connection can do forward progress only
due to MPTCP retransmissions - rtx can pick backup subflows.

This patch introduces a new flag flow MPTCP subflows: if the
underlying TCP connection made no progresses for long time,
and there are other less problematic subflows available, the
given subflow become stale.

Stale subflows are not considered active: if all non backup
subflows become stale, the MPTCP scheduler can pick backup
subflows for plain transmissions.

Stale subflows can return in active state, as soon as any reply
from the peer is observed.

Active backup scenarios can now leverage the available b/w
with no restrinction.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207
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>
2021-08-14 11:37:25 +01:00
Paolo Abeni 6da14d74e2 mptcp: cleanup sysctl data and helpers
Reorder the data in mptcp_pernet to avoid wasting space
with no reasons and constify the access helpers.

No functional changes intended.

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>
2021-08-14 11:37:25 +01:00
Paolo Abeni 1e1d9d6f11 mptcp: handle pending data on closed subflow
The PM can close active subflow, e.g. due to ingress RM_ADDR
option. Such subflow could carry data still unacked at the
MPTCP-level, both in the write and the rtx_queue, which has
never reached the other peer.

Currently the mptcp-level retransmission will deliver such data,
but at a very low rate (at most 1 DSM for each MPTCP rtx interval).

We can speed-up the recovery a lot, moving all the unacked in the
tcp write_queue, so that it will be pushed again via other
subflows, at the speed allowed by them.

Also make available the new helper for later patches.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207
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>
2021-08-14 11:37:25 +01:00
Paolo Abeni 71b7dec27f mptcp: less aggressive retransmission strategy
The current mptcp re-inject strategy is very aggressive,
we have mptcp-level retransmissions even on single subflow
connection, if the link in-use is lossy.

Let's be a little more conservative: we do retransmit
only if at least a subflow has write and rtx queue empty.

Additionally use the backup subflows only if the active
subflows are stale - no progresses in at least an rtx period
and ignore stale subflows for rtx timeout update

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207
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>
2021-08-14 11:37:25 +01:00
Paolo Abeni ce599c5163 mptcp: properly account bulk freed memory
After commit 879526030c ("mptcp: protect the rx path with
the msk socket spinlock") the rmem currently used by a given
msk is really sk_rmem_alloc - rmem_released.

The safety check in mptcp_data_ready() does not take the above
in due account, as a result legit incoming data is kept in
subflow receive queue with no reason, delaying or blocking
MPTCP-level ack generation.

This change addresses the issue introducing a new helper to fetch
the rmem memory and using it as needed. Additionally add a MIB
counter for the exceptional event described above - the peer is
misbehaving.

Finally, introduce the required annotation when rmem_released is
updated.

Fixes: 879526030c ("mptcp: protect the rx path with the msk socket spinlock")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/211
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>
2021-07-09 18:38:53 -07:00
Jakub Kicinski b6df00789e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Trivial conflict in net/netfilter/nf_tables_api.c.

Duplicate fix in tools/testing/selftests/net/devlink_port_split.py
- take the net-next version.

skmsg, and L4 bpf - keep the bpf code but remove the flags
and err params.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-06-29 15:45:27 -07:00
Paolo Abeni fde56eea01 mptcp: refine mptcp_cleanup_rbuf
The current cleanup rbuf tries a bit too hard to avoid acquiring
the subflow socket lock. We may end-up delaying the needed ack,
or skip acking a blocked subflow.

Address the above extending the conditions used to trigger the cleanup
to reflect more closely what TCP does and invoking tcp_cleanup_rbuf()
on all the active subflows.

Note that we can't replicate the exact tests implemented in
tcp_cleanup_rbuf(), as MPTCP lacks some of the required info - e.g.
ping-pong mode.

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>
2021-06-22 14:36:01 -07:00
Geliang Tang df377be387 mptcp: add deny_join_id0 in mptcp_options_received
This patch added a new flag named deny_join_id0 in struct
mptcp_options_received. Set it when MP_CAPABLE with the flag
MPTCP_CAP_DENYJOIN_ID0 is received.

Also add a new flag remote_deny_join_id0 in struct mptcp_pm_data. When the
flag deny_join_id0 is set, set this remote_deny_join_id0 flag.

In mptcp_pm_create_subflow_or_signal_addr, if the remote_deny_join_id0 flag
is set, and the remote address id is zero, stop this connection.

Suggested-by: Florian Westphal <fw@strlen.de>
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: David S. Miller <davem@davemloft.net>
2021-06-22 14:36:01 -07:00
Geliang Tang bab6b88e05 mptcp: add allow_join_id0 in mptcp_out_options
This patch defined a new flag MPTCP_CAP_DENY_JOIN_ID0 for the third bit,
labeled "C" of the MP_CAPABLE option.

Add a new flag allow_join_id0 in struct mptcp_out_options. If this flag is
set, send out the MP_CAPABLE option with the flag MPTCP_CAP_DENY_JOIN_ID0.

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: David S. Miller <davem@davemloft.net>
2021-06-22 14:36:01 -07:00
Geliang Tang d2f77960e5 mptcp: add sysctl allow_join_initial_addr_port
This patch added a new sysctl, named allow_join_initial_addr_port, to
control whether allow peers to send join requests to the IP address and
port number used by the initial subflow.

Suggested-by: Florian Westphal <fw@strlen.de>
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: David S. Miller <davem@davemloft.net>
2021-06-22 14:36:01 -07:00