Commit graph

254 commits

Author SHA1 Message Date
Paolo Abeni
54f1944ed6 mptcp: factor out mptcp_connect()
The current MPTCP connect implementation duplicates a bit of inet
code and does not use nor provide a struct proto->connect callback,
which in turn will not fit the upcoming fastopen implementation.

Refactor such implementation to use the common helper, moving the
MPTCP-specific bits into mptcp_connect(). Additionally, avoid an
indirect call to the subflow connect callback.

Note that the fastopen call-path invokes mptcp_connect() while already
holding the subflow socket lock. Explicitly keep track of such path
via a new MPTCP-level flag and handle the locking accordingly.

Additionally, track the connect flags in a new msk field to allow
propagating them to the subflow inet_stream_connect call.

Fixes: d98a82a6af ("mptcp: handle defer connect in mptcp_sendmsg")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.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>
2022-10-24 21:13:55 -07:00
Paolo Abeni
e72e403263 mptcp: set msk local address earlier
The mptcp_pm_nl_get_local_id() code assumes that the msk local address
is available at that point. For passive sockets, we initialize such
address at accept() time.

Depending on the running configuration and the user-space timing, a
passive MPJ subflow can join the msk socket before accept() completes.

In such case, the PM assigns a wrong local id to the MPJ subflow
and later PM netlink operations will end-up touching the wrong/unexpected
subflow.

All the above causes sporadic self-tests failures, especially when
the host is heavy loaded.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/308
Fixes: 01cacb00b3 ("mptcp: add netlink-based PM")
Fixes: d045b9eb95 ("mptcp: introduce implicit endpoints")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.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>
2022-10-24 21:13:55 -07:00
Jakub Kicinski
accc3b4a57 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29 14:30:51 -07:00
Menglong Dong
30e51b923e mptcp: fix unreleased socket in accept queue
The mptcp socket and its subflow sockets in accept queue can't be
released after the process exit.

While the release of a mptcp socket in listening state, the
corresponding tcp socket will be released too. Meanwhile, the tcp
socket in the unaccept queue will be released too. However, only init
subflow is in the unaccept queue, and the joined subflow is not in the
unaccept queue, which makes the joined subflow won't be released, and
therefore the corresponding unaccepted mptcp socket will not be released
to.

This can be reproduced easily with following steps:

1. create 2 namespace and veth:
   $ ip netns add mptcp-client
   $ ip netns add mptcp-server
   $ sysctl -w net.ipv4.conf.all.rp_filter=0
   $ ip netns exec mptcp-client sysctl -w net.mptcp.enabled=1
   $ ip netns exec mptcp-server sysctl -w net.mptcp.enabled=1
   $ ip link add red-client netns mptcp-client type veth peer red-server \
     netns mptcp-server
   $ ip -n mptcp-server address add 10.0.0.1/24 dev red-server
   $ ip -n mptcp-server address add 192.168.0.1/24 dev red-server
   $ ip -n mptcp-client address add 10.0.0.2/24 dev red-client
   $ ip -n mptcp-client address add 192.168.0.2/24 dev red-client
   $ ip -n mptcp-server link set red-server up
   $ ip -n mptcp-client link set red-client up

2. configure the endpoint and limit for client and server:
   $ ip -n mptcp-server mptcp endpoint flush
   $ ip -n mptcp-server mptcp limits set subflow 2 add_addr_accepted 2
   $ ip -n mptcp-client mptcp endpoint flush
   $ ip -n mptcp-client mptcp limits set subflow 2 add_addr_accepted 2
   $ ip -n mptcp-client mptcp endpoint add 192.168.0.2 dev red-client id \
     1 subflow

3. listen and accept on a port, such as 9999. The nc command we used
   here is modified, which makes it use mptcp protocol by default.
   $ ip netns exec mptcp-server nc -l -k -p 9999

4. open another *two* terminal and use each of them to connect to the
   server with the following command:
   $ ip netns exec mptcp-client nc 10.0.0.1 9999
   Input something after connect to trigger the connection of the second
   subflow. So that there are two established mptcp connections, with the
   second one still unaccepted.

5. exit all the nc command, and check the tcp socket in server namespace.
   And you will find that there is one tcp socket in CLOSE_WAIT state
   and can't release forever.

Fix this by closing all of the unaccepted mptcp socket in
mptcp_subflow_queue_clean() with __mptcp_close().

Now, we can ensure that all unaccepted mptcp sockets will be cleaned by
__mptcp_close() before they are released, so mptcp_sock_destruct(), which
is used to clean the unaccepted mptcp socket, is not needed anymore.

The selftests for mptcp is ran for this commit, and no new failures.

Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Fixes: 6aeed90450 ("mptcp: fix race on unaccepted mptcp sockets")
Cc: stable@vger.kernel.org
Reviewed-by: Jiang Biao <benbjiang@tencent.com>
Reviewed-by: Mengen Sun <mengensun@tencent.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-28 19:05:21 -07:00
Menglong Dong
26d3e21ce1 mptcp: factor out __mptcp_close() without socket lock
Factor out __mptcp_close() from mptcp_close(). The caller of
__mptcp_close() should hold the socket lock, and cancel mptcp work when
__mptcp_close() returns true.

This function will be used in the next commit.

Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Fixes: 6aeed90450 ("mptcp: fix race on unaccepted mptcp sockets")
Cc: stable@vger.kernel.org
Reviewed-by: Jiang Biao <benbjiang@tencent.com>
Reviewed-by: Mengen Sun <mengensun@tencent.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-28 19:05:21 -07:00
Matthieu Baerts
5efbf6f7f0 mptcp: add mptcp_for_each_subflow_safe helper
Similar to mptcp_for_each_subflow(): this is clearer now that the _safe
version is used in multiple places.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-15 12:01:02 +02:00
Paolo Abeni
c886d70286 mptcp: do not queue data on closed subflows
Dipanjan reported a syzbot splat at close time:

WARNING: CPU: 1 PID: 10818 at net/ipv4/af_inet.c:153
inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153
Modules linked in: uio_ivshmem(OE) uio(E)
CPU: 1 PID: 10818 Comm: kworker/1:16 Tainted: G           OE
5.19.0-rc6-g2eae0556bb9d #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153
Code: 21 02 00 00 41 8b 9c 24 28 02 00 00 e9 07 ff ff ff e8 34 4d 91
f9 89 ee 4c 89 e7 e8 4a 47 60 ff e9 a6 fc ff ff e8 20 4d 91 f9 <0f> 0b
e9 84 fe ff ff e8 14 4d 91 f9 0f 0b e9 d4 fd ff ff e8 08 4d
RSP: 0018:ffffc9001b35fa78 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000002879d0 RCX: ffff8881326f3b00
RDX: 0000000000000000 RSI: ffff8881326f3b00 RDI: 0000000000000002
RBP: ffff888179662674 R08: ffffffff87e983a0 R09: 0000000000000000
R10: 0000000000000005 R11: 00000000000004ea R12: ffff888179662400
R13: ffff888179662428 R14: 0000000000000001 R15: ffff88817e38e258
FS:  0000000000000000(0000) GS:ffff8881f5f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020007bc0 CR3: 0000000179592000 CR4: 0000000000150ee0
Call Trace:
 <TASK>
 __sk_destruct+0x4f/0x8e0 net/core/sock.c:2067
 sk_destruct+0xbd/0xe0 net/core/sock.c:2112
 __sk_free+0xef/0x3d0 net/core/sock.c:2123
 sk_free+0x78/0xa0 net/core/sock.c:2134
 sock_put include/net/sock.h:1927 [inline]
 __mptcp_close_ssk+0x50f/0x780 net/mptcp/protocol.c:2351
 __mptcp_destroy_sock+0x332/0x760 net/mptcp/protocol.c:2828
 mptcp_worker+0x5d2/0xc90 net/mptcp/protocol.c:2586
 process_one_work+0x9cc/0x1650 kernel/workqueue.c:2289
 worker_thread+0x623/0x1070 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
 </TASK>

The root cause of the problem is that an mptcp-level (re)transmit can
race with mptcp_close() and the packet scheduler checks the subflow
state before acquiring the socket lock: we can try to (re)transmit on
an already closed ssk.

Fix the issue checking again the subflow socket status under the
subflow socket lock protection. Additionally add the missing check
for the fallback-to-tcp case.

Fixes: d5f49190de ("mptcp: allow picking different xmit subflows")
Reported-by: Dipanjan Das <mail.dipanjan.das@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
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>
2022-08-05 08:51:28 +01:00
Paolo Abeni
c0bf3c6aa4 mptcp: move subflow cleanup in mptcp_destroy_common()
If the mptcp socket creation fails due to a CGROUP_INET_SOCK_CREATE
eBPF program, the MPTCP protocol ends-up leaking all the subflows:
the related cleanup happens in __mptcp_destroy_sock() that is not
invoked in such code path.

Address the issue moving the subflow sockets cleanup in the
mptcp_destroy_common() helper, which is invoked in every msk cleanup
path.

Additionally get rid of the intermediate list_splice_init step, which
is an unneeded relic from the past.

The issue is present since before the reported root cause commit, but
any attempt to backport the fix before that hash will require a complete
rewrite.

Fixes: e16163b6e2 ("mptcp: refactor shutdown and close")
Reported-by: Nguyen Dinh Phi <phind.uet@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Co-developed-by: Nguyen Dinh Phi <phind.uet@gmail.com>
Signed-off-by: Nguyen Dinh Phi <phind.uet@gmail.com>
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>
2022-08-05 08:51:28 +01:00
Paolo Abeni
3ad14f54bd mptcp: more accurate MPC endpoint tracking
Currently the id accounting for the ID 0 subflow is not correct:
at creation time we mark (correctly) as unavailable the endpoint
id corresponding the MPC subflow source address, while at subflow
removal time set as available the id 0.

With this change we track explicitly the endpoint id corresponding
to the MPC subflow so that we can mark it as available at removal time.
Additionally this allow deleting the initial subflow via the NL PM
specifying the corresponding endpoint id.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.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>
2022-07-12 18:37:20 -07:00
Paolo Abeni
f5360e9b31 mptcp: introduce and use mptcp_pm_send_ack()
The in-kernel PM has a bit of duplicate code related to ack
generation. Create a new helper factoring out the PM-specific
needs and use it in a couple of places.

As a bonus, mptcp_subflow_send_ack() is not used anymore
outside its own compilation unit and can become static.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.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>
2022-07-12 18:37:19 -07:00
Geliang Tang
f7657ff4a7 mptcp: move MPTCPOPT_HMAC_LEN to net/mptcp.h
Move macro MPTCPOPT_HMAC_LEN definition from net/mptcp/protocol.h to
include/net/mptcp.h.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-09 12:19:23 +01:00
Kishen Maloor
892f396c8e mptcp: netlink: issue MP_PRIO signals from userspace PMs
This change updates MPTCP_PM_CMD_SET_FLAGS to allow userspace PMs
to issue MP_PRIO signals over a specific subflow selected by
the connection token, local and remote address+port.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/286
Fixes: 702c2f646d ("mptcp: netlink: allow userspace-driven subflow establishment")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-06 12:50:26 +01:00
Mat Martineau
a657430260 mptcp: Acquire the subflow socket lock before modifying MP_PRIO flags
When setting up a subflow's flags for sending MP_PRIO MPTCP options, the
subflow socket lock was not held while reading and modifying several
struct members that are also read and modified in mptcp_write_options().

Acquire the subflow socket lock earlier and send the MP_PRIO ACK with
that lock already acquired. Add a new variant of the
mptcp_subflow_send_ack() helper to use with the subflow lock held.

Fixes: 067065422f ("mptcp: add the outgoing MP_PRIO support")
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>
2022-07-06 12:50:26 +01:00
Paolo Abeni
6aeed90450 mptcp: fix race on unaccepted mptcp sockets
When the listener socket owning the relevant request is closed,
it frees the unaccepted subflows and that causes later deletion
of the paired MPTCP sockets.

The mptcp socket's worker can run in the time interval between such delete
operations. When that happens, any access to msk->first will cause an UaF
access, as the subflow cleanup did not cleared such field in the mptcp
socket.

Address the issue explicitly traversing the listener socket accept
queue at close time and performing the needed cleanup on the pending
msk.

Note that the locking is a bit tricky, as we need to acquire the msk
socket lock, while still owning the subflow socket one.

Fixes: 86e39e0448 ("mptcp: keep track of local endpoint still available for each msk")
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>
2022-06-28 20:45:42 -07:00
Paolo Abeni
d51991e2e3 mptcp: fix shutdown vs fallback race
If the MPTCP socket shutdown happens before a fallback
to TCP, and all the pending data have been already spooled,
we never close the TCP connection.

Address the issue explicitly checking for critical condition
at fallback time.

Fixes: 1e39e5a32a ("mptcp: infinite mapping sending")
Fixes: 0348c690ed ("mptcp: add the fallback check")
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>
2022-06-28 20:45:42 -07:00
Geliang Tang
76a13b3157 mptcp: invoke MP_FAIL response when needed
mptcp_mp_fail_no_response shouldn't be invoked on each worker run, it
should be invoked only when MP_FAIL response timeout occurs.

This patch refactors the MP_FAIL response logic.

It leverages the fact that only the MPC/first subflow can gracefully
fail to avoid unneeded subflows traversal: the failing subflow can
be only msk->first.

A new 'fail_tout' field is added to the subflow context to record the
MP_FAIL response timeout and use such field to reliably share the
timeout timer between the MP_FAIL event and the MPTCP socket close
timeout.

Finally, a new ack is generated to send out MP_FAIL notification as soon
as we hit the relevant condition, instead of waiting a possibly unbound
time for the next data packet.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/281
Fixes: d9fb797046 ("mptcp: Do not traverse the subflow connection list without lock")
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-28 20:45:42 -07:00
Mat Martineau
d9fb797046 mptcp: Do not traverse the subflow connection list without lock
The MPTCP socket's conn_list (list of subflows) requires the socket lock
to access. The MP_FAIL timeout code added such an access, where it would
check the list of subflows both in timer context and (later) in workqueue
context where the socket lock is held.

Rather than check the list twice, remove the check in the timeout
handler and only depend on the check in the workqueue. Also remove the
MPTCP_FAIL_NO_RESPONSE flag, since mptcp_mp_fail_no_response() has
insignificant overhead and can be checked on each worker run.

Fixes: 49fa1919d6 ("mptcp: reset subflow when MP_FAIL doesn't respond")
Reported-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-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>
2022-05-19 20:05:07 -07:00
Paolo Abeni
7b16871f99 mptcp: stop using the mptcp_has_another_subflow() helper
The mentioned helper requires the msk socket lock, and the
current callers don't own it nor can't acquire it, so the
access is racy.

All the current callers are really checking for infinite mapping
fallback, and the latter condition is explicitly tracked by
the relevant msk variable: we can safely remove the caller usage
- and the caller itself.

The issue is present since MP_FAIL implementation, but the
fix only applies since the infinite fallback support, ence the
somewhat unexpected fixes tag.

Fixes: 0530020a7c ("mptcp: track and update contiguous data status")
Acked-and-tested-by: Geliang Tang <geliang.tang@suse.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>
2022-05-19 20:05:07 -07:00
Jakub Kicinski
d7e6f58360 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/ethernet/mellanox/mlx5/core/main.c
  b33886971d ("net/mlx5: Initialize flow steering during driver probe")
  40379a0084 ("net/mlx5_fpga: Drop INNOVA TLS support")
  f2b41b32cd ("net/mlx5: Remove ipsec_ops function table")
https://lore.kernel.org/all/20220519040345.6yrjromcdistu7vh@sx1/
  16d42d3133 ("net/mlx5: Drain fw_reset when removing device")
  8324a02c34 ("net/mlx5: Add exit route when waiting for FW")
https://lore.kernel.org/all/20220519114119.060ce014@canb.auug.org.au/

tools/testing/selftests/net/mptcp/mptcp_join.sh
  e274f71540 ("selftests: mptcp: add subflow limits test-cases")
  b6e074e171 ("selftests: mptcp: add infinite map testcase")
  5ac1d2d634 ("selftests: mptcp: Add tests for userspace PM type")
https://lore.kernel.org/all/20220516111918.366d747f@canb.auug.org.au/

net/mptcp/options.c
  ba2c89e0ea ("mptcp: fix checksum byte order")
  1e39e5a32a ("mptcp: infinite mapping sending")
  ea66758c17 ("tcp: allow MPTCP to update the announced window")
https://lore.kernel.org/all/20220519115146.751c3a37@canb.auug.org.au/

net/mptcp/pm.c
  95d6865178 ("mptcp: fix subflow accounting on close")
  4d25247d3a ("mptcp: bypass in-kernel PM restrictions for non-kernel PMs")
https://lore.kernel.org/all/20220516111435.72f35dca@canb.auug.org.au/

net/mptcp/subflow.c
  ae66fb2ba6 ("mptcp: Do TCP fallback on early DSS checksum failure")
  0348c690ed ("mptcp: add the fallback check")
  f8d4bcacff ("mptcp: infinite mapping receiving")
https://lore.kernel.org/all/20220519115837.380bb8d4@canb.auug.org.au/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-19 11:23:59 -07:00
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
f3589be0c4 mptcp: never shrink offered window
As per RFC, the offered MPTCP-level window should never shrink.
While we currently track the right edge, we don't enforce the
above constraint on the wire.
Additionally, concurrent xmit on different subflows can end-up in
erroneous right edge update.
Address the above explicitly updating the announced window and
protecting the update with an additional atomic operation (sic)

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-05 19:00:15 -07:00
Florian Westphal
702c2f646d mptcp: netlink: allow userspace-driven subflow establishment
This allows userspace to tell kernel to add a new subflow to an existing
mptcp connection.

Userspace provides the token to identify the mptcp-level connection
that needs a change in active subflows and the local and remote
addresses of the new or the to-be-removed subflow.

MPTCP_PM_CMD_SUBFLOW_CREATE requires the following parameters:
{ token, { loc_id, family, loc_addr4 | loc_addr6 }, { family, rem_addr4 |
rem_addr6, rem_port }

MPTCP_PM_CMD_SUBFLOW_DESTROY requires the following parameters:
{ token, { family, loc_addr4 | loc_addr6, loc_port }, { family, rem_addr4 |
rem_addr6, rem_port }

Acked-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.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>
2022-05-04 10:49:32 +01:00
Kishen Maloor
d9a4594eda mptcp: netlink: Add MPTCP_PM_CMD_REMOVE
This change adds a MPTCP netlink command for issuing a
REMOVE_ADDR signal for an address over the chosen MPTCP
connection from a userspace path manager.

The command requires the following parameters: {token, loc_id}.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-04 10:49:31 +01:00
Kishen Maloor
9ab4807c84 mptcp: netlink: Add MPTCP_PM_CMD_ANNOUNCE
This change adds a MPTCP netlink interface for issuing
ADD_ADDR advertisements over the chosen MPTCP connection from a
userspace path manager.

The command requires the following parameters:
{ token, { loc_id, family, daddr4 | daddr6 [, dport] } [, if_idx],
flags[signal] }.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-04 10:49:31 +01:00
Kishen Maloor
8b20137012 mptcp: read attributes of addr entries managed by userspace PMs
This change introduces a parallel path in the kernel for retrieving
the local id, flags, if_index for an addr entry in the context of
an MPTCP connection that's being managed by a userspace PM. The
userspace and in-kernel PM modes deviate in their procedures for
obtaining this information.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-04 10:49:31 +01:00
Kishen Maloor
4638de5aef mptcp: handle local addrs announced by userspace PMs
This change adds an internal function to store/retrieve local
addrs announced by userspace PM implementations to/from its kernel
context. The function addresses the requirements of three scenarios:
1) ADD_ADDR announcements (which require that a local id be
provided), 2) retrieving the local id associated with an address,
and also where one may need to be assigned, and 3) reissuance of
ADD_ADDRs when there's a successful match of addr/id.

The list of all stored local addr entries is held under the
MPTCP sock structure. Memory for these entries is allocated from
the sock option buffer, so the list of addrs is bounded by optmem_max.
The list if not released via REMOVE_ADDR signals is ultimately
freed when the sock is destructed.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-04 10:49:31 +01:00
Kishen Maloor
70c708e826 mptcp: establish subflows from either end of connection
This change updates internal logic to permit subflows to be
established from either the client or server ends of MPTCP
connections. This symmetry and added flexibility may be
harnessed by PM implementations running on either end in
creating new subflows.

The essence of this change lies in not relying on the
"server_side" flag (which continues to be available if needed).

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-03 16:54:55 -07:00
Kishen Maloor
d1ace2d9ab mptcp: reflect remote port (not 0) in ANNOUNCED events
Per RFC 8684, if no port is specified in an ADD_ADDR message, MPTCP
SHOULD attempt to connect to the specified address on the same port
as the port that is already in use by the subflow on which the
ADD_ADDR signal was sent.

To facilitate that, this change reflects the specific remote port in
use by that subflow in MPTCP_EVENT_ANNOUNCED events.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-03 16:54:55 -07:00
Kishen Maloor
4d25247d3a mptcp: bypass in-kernel PM restrictions for non-kernel PMs
Current limits on the # of addresses/subflows must apply only to
in-kernel PM managed sockets. Thus this change removes such
restrictions on connections overseen by non-kernel (e.g. userspace)
PMs. This change also ensures that the kernel does not record stats
inside struct mptcp_pm_data updated along kernel code paths when exercised
via non-kernel PMs.

Additionally, address announcements are acknolwedged and subflow
requests are honored only when it's deemed that	a userspace path
manager	is active at the time.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-03 16:54:54 -07:00
Mat Martineau
6bb63ccc25 mptcp: Add a per-namespace sysctl to set the default path manager type
The new net.mptcp.pm_type sysctl determines which path manager will be
used by each newly-created MPTCP socket.

v2: Handle builds without CONFIG_SYSCTL
v3: Clarify logic for type-specific PM init (Geliang Tang and Paolo Abeni)

Acked-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>
2022-04-29 17:25:14 -07:00
Mat Martineau
14b06811be mptcp: Bypass kernel PM when userspace PM is enabled
When a MPTCP connection is managed by a userspace PM, bypass the kernel
PM for incoming advertisements and subflow events. Netlink events are
still sent to userspace.

v2: Remove unneeded check in mptcp_pm_rm_addr_received() (Kishen Maloor)
v3: Add and use helper function for PM mode (Paolo Abeni)

Acked-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-29 17:25:14 -07:00
Mat Martineau
d85a8fde71 mptcp: Add a member to mptcp_pm_data to track kernel vs userspace mode
When adding support for netlink path management commands, the kernel
needs to know whether paths are being controlled by the in-kernel path
manager or a userspace PM.

Acked-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>
2022-04-29 17:25:13 -07:00
Mat Martineau
9273b9d579 mptcp: Remove redundant assignments in path manager init
A few members of the mptcp_pm_data struct were assigned to hard-coded
values in mptcp_pm_data_reset(), and then immediately changed in
mptcp_pm_nl_data_init().

Instead, flatten all the assignments in to mptcp_pm_data_reset().

v2: Resolve conflicts due to rename of mptcp_pm_data_reset()
v4: Resolve conflict in mptcp_pm_data_reset()

Acked-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>
2022-04-29 17:25:13 -07:00
Geliang Tang
49fa1919d6 mptcp: reset subflow when MP_FAIL doesn't respond
This patch adds a new msk->flags bit MPTCP_FAIL_NO_RESPONSE, then reuses
sk_timer to trigger a check if we have not received a response from the
peer after sending MP_FAIL. If the peer doesn't respond properly, reset
the subflow.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-27 10:45:54 +01:00
Geliang Tang
9c81be0dbc mptcp: add MP_FAIL response support
This patch adds a new struct member mp_fail_response_expect in struct
mptcp_subflow_context to support MP_FAIL response. In the single subflow
with checksum error and contiguous data special case, a MP_FAIL is sent
in response to another MP_FAIL.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-27 10:45:54 +01:00
Geliang Tang
1e39e5a32a mptcp: infinite mapping sending
This patch adds the infinite mapping sending logic.

Add a new flag send_infinite_map in struct mptcp_subflow_context. Set
it true when a single contiguous subflow is in use and the
allow_infinite_fallback flag is true in mptcp_pm_mp_fail_received().

In mptcp_sendmsg_frag(), if this flag is true, call the new function
mptcp_update_infinite_map() to set the infinite mapping.

Add a new flag infinite_map in struct mptcp_ext, set it true in
mptcp_update_infinite_map(), and check this flag in a new helper
mptcp_check_infinite_map().

In mptcp_update_infinite_map(), set data_len to 0, and clear the
send_infinite_map flag, then do fallback.

In mptcp_established_options(), use the helper mptcp_check_infinite_map()
to let the infinite mapping DSS can be sent out in the fallback mode.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-23 11:51:05 +01:00
Geliang Tang
0530020a7c mptcp: track and update contiguous data status
This patch adds a new member allow_infinite_fallback in mptcp_sock,
which is initialized to 'true' when the connection begins and is set
to 'false' on any retransmit or successful MP_JOIN. Only do infinite
mapping fallback if there is a single subflow AND there have been no
retransmissions AND there have never been any MP_JOINs.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-23 11:51:05 +01:00
Paolo Abeni
43f5b111d1 mptcp: reset the packet scheduler on incoming MP_PRIO
When an incoming MP_PRIO option changes the backup
status of any subflow, we need to reset the packet
scheduler status, or the next send could keep using
the previously selected subflow, without taking in account
the new priorities.

Reported-by: Davide Caratti <dcaratti@redhat.com>
Fixes: 40453a5c61 ("mptcp: add the incoming MP_PRIO support")
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>
2022-04-11 11:55:53 +01:00
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