commit 27b0e701d3 upstream.
Accessing the transmit queue without owning the msk socket lock is
inherently racy, hence __mptcp_check_push() could actually quit early
even when there is pending data.
That in turn could cause unexpected tx lock and timeout.
Dropping the early check avoids the race, implicitly relaying on later
tests under the relevant lock. With such change, all the other
mptcp_send_head() call sites are now under the msk socket lock and we
can additionally drop the now unneeded annotation on the transmit head
pointer accesses.
Fixes: 6e628cd3a8 ("mptcp: use mptcp release_cb for delayed tasks")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Geliang Tang <geliang@kernel.org>
Tested-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251028-net-mptcp-send-timeout-v1-1-38ffff5a9ec8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4b1ff850e0 upstream.
When servers set the C-flag in their MP_CAPABLE to tell clients not to
create subflows to the initial address and port, clients will likely not
use their other endpoints. That's because the in-kernel path-manager
uses the 'subflow' endpoints to create subflows only to the initial
address and port.
If the limits have not been modified to accept ADD_ADDR, the client
doesn't try to establish new subflows. If the limits accept ADD_ADDR,
the routing routes will be used to select the source IP.
The C-flag is typically set when the server is operating behind a legacy
Layer 4 load balancer, or using anycast IP address. Clients having their
different 'subflow' endpoints setup, don't end up creating multiple
subflows as expected, and causing some deployment issues.
A special case is then added here: when servers set the C-flag in the
MPC and directly sends an ADD_ADDR, this single ADD_ADDR is accepted.
The 'subflows' endpoints will then be used with this new remote IP and
port. This exception is only allowed when the ADD_ADDR is sent
immediately after the 3WHS, and makes the client switching to the 'fully
established' mode. After that, 'select_local_address()' will not be able
to find any subflows, because 'id_avail_bitmap' will be filled in
mptcp_pm_create_subflow_or_signal_addr(), when switching to 'fully
established' mode.
Fixes: df377be387 ("mptcp: add deny_join_id0 in mptcp_options_received")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/536
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-1-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the mibs required to cover the few possible fallback causes still
lacking suck info.
Move the relevant mib increment into the fallback helper, so that no
eventual future fallback operation will miss a paired mib increment.
Additionally track failed fallback via its own mib, such mib is
incremented only when a fallback mandated by the protocol fails - due to
racing subflow creation.
While at the above, rename an existing helper to reduce long lines
problems all along.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250723-net-next-mptcp-track-fallbacks-v1-1-a83cce08f2d5@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The TCP_MAXSEG socket option is currently not supported by MPTCP, mainly
because it has never been requested before. But there are still valid
use-cases, e.g. with HAProxy.
This patch adds its support in MPTCP by propagating the value to all
subflows. The get part looks at the value on the first subflow, to be as
closed as possible to TCP. Only one value can be returned for the cached
MSS, so this can come only from one subflow.
Similar to mptcp_setsockopt_first_sf_only(), a generic helper
mptcp_setsockopt_all_subflows() is added to set sockopt for each
subflows of the mptcp socket.
Add a new member for struct mptcp_sock to store the TCP_MAXSEG value,
and return this value in getsockopt.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/515
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250719-net-next-mptcp-tcp_maxseg-v2-3-8c910fbc5307@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We have races similar to the one addressed by the previous patch between
subflow failing and additional subflow creation. They are just harder to
trigger.
The solution is similar. Use a separate flag to track the condition
'socket state prevent any additional subflow creation' protected by the
fallback lock.
The socket fallback makes such flag true, and also receiving or sending
an MP_FAIL option.
The field 'allow_infinite_fallback' is now always touched under the
relevant lock, we can drop the ONCE annotation on write.
Fixes: 478d770008 ("mptcp: send out MP_FAIL when data checksum fails")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250714-net-mptcp-fallback-races-v1-2-391aff963322@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch defines the original in-kernel netlink path manager as a
new struct mptcp_pm_ops named "mptcp_pm_kernel", and register it in
mptcp_pm_kernel_register(). And define the userspace path manager as
a new struct mptcp_pm_ops named "mptcp_pm_userspace", and register it
in mptcp_pm_init().
To ensure that there's always a valid path manager available, the default
path manager "mptcp_pm_kernel" will be skipped in mptcp_pm_unregister().
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250313-net-next-mptcp-pm-ops-intro-v1-7-f4e4a88efc50@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
In order to allow users to develop their own BPF-based path manager,
this patch defines a struct ops "mptcp_pm_ops" for an MPTCP path
manager, which contains a set of interfaces. Currently only init()
and release() interfaces are included, subsequent patches will add
others step by step.
Add a set of functions to register, unregister, find and validate a
given path manager struct ops.
"list" is used to add this path manager to mptcp_pm_list list when
it is registered. "name" is used to identify this path manager.
mptcp_pm_find() uses "name" to find a path manager on the list.
mptcp_pm_unregister is not used in this set, but will be invoked in
.unreg of struct bpf_struct_ops. mptcp_pm_validate() will be invoked
in .validate of struct bpf_struct_ops. That's why they are exported.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250313-net-next-mptcp-pm-ops-intro-v1-6-f4e4a88efc50@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Before this patch, the PM code was dispersed in different places:
- pm.c had common code for all PMs, but also Netlink specific code that
will not be needed with the future BPF path-managers.
- pm_netlink.c had common Netlink code.
To clarify the code, a reorganisation is suggested here, only by moving
code around, and small helper renaming to avoid confusions:
- pm_netlink.c now only contains common PM Netlink code:
- PM events: this code was already there
- shared helpers around Netlink code that were already there as well
- shared Netlink commands code from pm.c
- pm.c now no longer contain Netlink specific code.
- protocol.h has been updated accordingly:
- mptcp_nl_fill_addr() no longer need to be exported.
The code around the PM is now less confusing, which should help for the
maintenance in the long term.
This will certainly impact future backports, but because other cleanups
have already done recently, and more are coming to ease the addition of
a new path-manager controlled with BPF (struct_ops), doing that now
seems to be a good time. Also, many issues around the PM have been fixed
a few months ago while increasing the code coverage in the selftests, so
such big reorganisation can be done with more confidence now.
No behavioural changes intended.
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250307-net-next-mptcp-pm-reorg-v1-15-abef20ada03b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Before this patch, the PM code was dispersed in different places:
- pm.c had common code for all PMs
- pm_netlink.c was supposed to be about the in-kernel PM, but also had
exported common helpers, callbacks used by the different PMs, NL
events for PM userspace daemon, etc. quite confusing.
- pm_userspace.c had userspace PM only code, but using specific
in-kernel PM helpers
To clarify the code, a reorganisation is suggested here, only by moving
code around, and (un)exporting functions:
- helpers used from both PMs and not linked to Netlink
- callbacks used by different PMs, e.g. ADD_ADDR management
- some helpers have been marked as 'static'
- protocol.h has been updated accordingly
- (while at it, a needless if before a kfree(), spot by checkpatch in
mptcp_remove_anno_list_by_saddr(), has been removed)
The code around the PM is now less confusing, which should help for the
maintenance in the long term.
This will certainly impact future backports, but because other cleanups
have already done recently, and more are coming to ease the addition of
a new path-manager controlled with BPF (struct_ops), doing that now
seems to be a good time. Also, many issues around the PM have been fixed
a few months ago while increasing the code coverage in the selftests, so
such big reorganisation can be done with more confidence now.
No behavioural changes intended.
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250307-net-next-mptcp-pm-reorg-v1-13-abef20ada03b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
To make it clear what actions are in-kernel PM specific and which ones
are not and done for all PMs, e.g. sending ADD_ADDR and close associated
subflows when a RM_ADDR is received.
The behavioural is changed a bit: MPTCP_PM_ADD_ADDR_RECEIVED is now
treated after MPTCP_PM_ADD_ADDR_SEND_ACK and MPTCP_PM_RM_ADDR_RECEIVED,
but that should not change anything in practice.
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250307-net-next-mptcp-pm-reorg-v1-10-abef20ada03b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When destroying an MPTCP socket, some userspace PM specific code was
called from mptcp_destroy_common() in protocol.c. That feels wrong, and
it is the only case.
Instead, the core now calls mptcp_pm_destroy() from pm.c which is now in
charge of cleaning the announced addresses list, and ask the different
PMs to do extra cleaning if needed, e.g. the userspace PM, if used, will
clean the local addresses list.
While at it, the userspace PM specific helper has been prefixed with
'mptcp_userspace_pm_' like the other ones.
No behavioural changes intended.
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250307-net-next-mptcp-pm-reorg-v1-9-abef20ada03b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, in-kernel PM specific helpers are prefixed with
'mptcp_pm_nl_'. But here 'mptcp_pm_nl_is_init_remote_addr' is not
specific to this PM: it is called from pm.c for both the in-kernel and
userspace PMs.
To avoid confusions, the '_nl' bit has been removed from the name.
No behavioural changes intended.
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250307-net-next-mptcp-pm-reorg-v1-7-abef20ada03b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, in-kernel PM specific helpers are prefixed with
'mptcp_pm_nl_'. But here 'mptcp_pm_nl_subflow_chk_stale' is not specific
to this PM: it is called from pm.c for both the in-kernel and userspace
PMs.
To avoid confusions, the '_nl' bit has been removed from the name.
No behavioural changes intended.
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250307-net-next-mptcp-pm-reorg-v1-6-abef20ada03b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, in-kernel PM specific helpers are prefixed with
'mptcp_pm_nl_'. But here 'mptcp_pm_nl_work' is not specific to this PM:
it is called from the core to call helpers, some of them needed by both
the in-kernel and userspace PMs.
To avoid confusions, the '_nl' bit has been removed from the name.
Also used 'worker' instead of 'work', similar to protocol.c's worker.
No behavioural changes intended.
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250307-net-next-mptcp-pm-reorg-v1-4-abef20ada03b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The following code in mptcp_userspace_pm_get_local_id() that assigns "skc"
to "new_entry" is not allowed in BPF if we use the same code to implement
the get_local_id() interface of a BFP path manager:
memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
new_entry.addr = *skc;
new_entry.addr.id = 0;
new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
To solve the issue, this patch moves this assignment to "new_entry" forward
to mptcp_pm_get_local_id(), and then passing "new_entry" as a parameter to
both mptcp_pm_nl_get_local_id() and mptcp_userspace_pm_get_local_id().
No behavioural changes intended.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250307-net-next-mptcp-pm-reorg-v1-1-abef20ada03b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
After the RX path refactor the mentioned function is expected to run
frequently, let's optimize it a bit.
Scan for ready subflow from the last processed one, and stop after
traversing the list once or reaching the msk memory limit - instead of
looking for dubious per-subflow conditions.
Also re-order the memory limit checks, to avoid duplicate tests.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250218-net-next-mptcp-rx-path-refactor-v1-7-4a47d90d7998@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
After commit c2e6048fa1 ("mptcp: fix race in release_cb") we can
move the whole MPTCP rx path under the socket lock leveraging the
release_cb.
We can drop a bunch of spin_lock pairs in the receive functions, use
a single receive queue and invoke __mptcp_move_skbs only when subflows
ask for it.
This will allow more cleanup in the next patch.
Some changes are worth specific mention:
The msk rcvbuf update now always happens under both the msk and the
subflow socket lock: we can drop a bunch of ONCE annotation and
consolidate the checks.
When the skbs move is delayed at msk release callback time, even the
msk rcvbuf update is delayed; additionally take care of such action in
__mptcp_move_skbs().
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250218-net-next-mptcp-rx-path-refactor-v1-3-4a47d90d7998@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When we will move the whole RX path under the msk socket lock, updating
the already queued skb for passive fastopen socket at 3rd ack time will
be extremely painful and race prone
The map_seq for already enqueued skbs is used only to allow correct
coalescing with later data; preventing collapsing to the first skb of
a fastopen connect we can completely remove the
__mptcp_fastopen_gen_msk_ackseq() helper.
Before dropping this helper, a new item had to be added to the
mptcp_skb_cb structure. Because this item will be frequently tested in
the fast path -- almost on every packet -- and because there is free
space there, a single byte is used instead of a bitfield. This micro
optimisation slightly reduces the number of CPU operations to do the
associated check.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250218-net-next-mptcp-rx-path-refactor-v1-2-4a47d90d7998@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch updates the interfaces set_flags to reduce repetitive
code, adds a new parameter 'local' for them.
The local address is parsed in public helper mptcp_pm_nl_set_flags_doit(),
then pass it to mptcp_pm_nl_set_flags() and mptcp_userspace_pm_set_flags().
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The first parameter 'skb' in mptcp_pm_nl_set_flags() is only used to
obtained the network namespace, which can also be obtained through the
second parameters 'info' by using genl_info_net() helper.
This patch drops these useless parameters 'skb' in all three set_flags()
interfaces.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The netlink messages are sent both in mptcp_pm_nl_get_addr() and
mptcp_userspace_pm_get_addr(), this makes the code somewhat repetitive.
This is because the netlink PM and userspace PM use different locks to
protect the address entry that needs to be sent via the netlink message.
The former uses rcu read lock, and the latter uses msk->pm.lock.
The current get_addr() flow looks like this:
lock();
entry = get_entry();
send_nlmsg(entry);
unlock();
After holding the lock, get the entry from the list, send the entry, and
finally release the lock.
This patch changes the process by getting the entry while holding the lock,
then making a copy of the entry so that the lock can be released. Finally,
the copy of the entry is sent without locking:
lock();
entry = get_entry();
*copy = *entry;
unlock();
send_nlmsg(copy);
This way we can reuse the send_nlmsg() code in get_addr() interfaces
between the netlink PM and userspace PM. They only need to implement their
own get_addr() interfaces to hold the different locks, get the entry from
the different lists, then release the locks.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The address id is parsed both in mptcp_pm_nl_get_addr() and
mptcp_userspace_pm_get_addr(), this makes the code somewhat repetitive.
So this patch adds a new parameter 'id' for all get_addr() interfaces.
The address id is only parsed in mptcp_pm_nl_get_addr_doit(), then pass
it to both mptcp_pm_nl_get_addr() and mptcp_userspace_pm_get_addr().
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The first parameters 'skb' of get_addr() interfaces are now useless
since mptcp_userspace_pm_get_sock() helper is used. This patch drops
these useless parameters of them.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Three netlink functions:
mptcp_pm_nl_get_addr_doit()
mptcp_pm_nl_get_addr_dumpit()
mptcp_pm_nl_set_flags_doit()
are generic, implemented for each PM, in-kernel PM and userspace PM. It's
clearer to move them from pm_netlink.c to pm.c.
And the linked three path manager wrappers
mptcp_pm_get_addr()
mptcp_pm_dump_addr()
mptcp_pm_set_flags()
can be changed as static functions, no need to export them in protocol.h.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
mptcp_pm_remove_addrs() actually only deletes one address, which does
not match its name. This patch renames it to mptcp_pm_remove_addr_entry()
and changes the parameter "rm_list" to "entry".
With the help of mptcp_pm_remove_addr_entry(), it's no longer necessary to
move the entry to be deleted to free_list and then traverse the list to
delete the entry, which is not allowed in BPF. The entry can be directly
deleted through list_del_rcu() and sock_kfree_s() now.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241213-net-next-mptcp-pm-misc-cleanup-v1-5-ddb6d00109a8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since mptcp_pm_remove_addrs() is only called from the userspace PM, this
patch moves it into pm_userspace.c.
For this, lookup_subflow_by_saddr() and remove_anno_list_by_saddr()
helpers need to be exported in protocol.h. Also add "mptcp_" prefix for
these helpers.
Here, mptcp_pm_remove_addrs() is not changed to a static function because
it will be used in BPF Path Manager.
This patch doesn't change the behaviour of the code, just refactoring.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241213-net-next-mptcp-pm-misc-cleanup-v1-4-ddb6d00109a8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We introduce the same handling for potential data races with the
'fully_established' flag in subflow as previously done for
msk->fully_established.
Additionally, we make a crucial change: convert the subflow's
'fully_established' from 'bit_field' to 'bool' type. This is
necessary because methods for avoiding data races don't work well
with 'bit_field'. Specifically, the 'READ_ONCE' needs to know
the size of the variable being accessed, which is not supported in
'bit_field'. Also, 'test_bit' expect the address of 'bit_field'.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/516
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241021-net-next-mptcp-misc-6-13-v1-2-1ef02746504a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
An MPTCP firewall blackhole can be detected if the following SYN
retransmission after a fallback to "plain" TCP is accepted.
In case of blackhole, a similar technique to the one in place with TFO
is now used: MPTCP can be disabled for a certain period of time, 1h by
default. This time period will grow exponentially when more blackhole
issues get detected right after MPTCP is re-enabled and will reset to
the initial value when the blackhole issue goes away.
The blackhole period can be modified thanks to a new sysctl knob:
blackhole_timeout. Two new MIB counters help understanding what's
happening:
- 'Blackhole', incremented when a blackhole is detected.
- 'MPCapableSYNTXDisabled', incremented when an MPTCP connection
directly falls back to TCP during the blackhole period.
Because the technique is inspired by the one used by TFO, an important
part of the new code is similar to what can find in tcp_fastopen.c, with
some adaptations to the MPTCP case.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/57
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20240909-net-next-mptcp-fallback-x-mpc-v1-3-da7ebb4cd2a3@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
