Commit Graph

155 Commits

Author SHA1 Message Date
Matthieu Baerts (NGI0)
6ea199a938 mptcp: pm: avoid using del_timer directly
mptcp_pm_announced_del_timer() removes the matched ADD_ADDR entry (if
found) from the ADD_ADDR list only if check_id is false. That's
dangerous, and not clear, because it means the caller should be free the
entry only in some cases, and it easy to miss that.

Instead, make it static, and call it from mptcp_pm_add_addr_echoed,
which is the only other case where mptcp_pm_add_addr_del_timer should be
called with check_id set to true. Bonus with that: a second call to
mptcp_pm_add_addr_lookup_by_addr() can be avoided.

Note that instead of adding the signature above to avoid a compilation
issue because this helper is called before the definition of the
function, the whole helper is moved above where it is first called. Its
content is untouched, except the addition of the 'static' keyboard.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-14-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 15:33:39 -07:00
Matthieu Baerts (NGI0)
d0f866e648 mptcp: pm: make mptcp_pm_add_addr_send_ack static
Only used in pm.c.

Note that the signature is added above: it is easier than moving the
code around, because this helper depends on mptcp_pm_schedule_work which
is declared below.

While at it, explicitly mark it as to be called while pm->lock is held.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-13-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 15:33:39 -07:00
Matthieu Baerts (NGI0)
938490767e mptcp: pm: remove add_ prefix from timer
Similar to the two previous commits, using the 'add' prefix is
confusing, also confirmed by [1].

Now that the structure has been renamed to include 'add_addr' in its
name, easier to know the timer is linked to the ADD_ADDR, no need to
add the confusing prefix, or an unneeded longer one.

While at it, also update the ADD_ADDR timer helper to clearly specify it
is linked to ADD_ADDR, and it is not there to add a new timer.

Link: https://lore.kernel.org/20251117100745.1913963-1-edumazet@google.com [1]
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-12-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 15:33:39 -07:00
Matthieu Baerts (NGI0)
7d4dacc8cc mptcp: pm: uniform announced addresses helpers
Similar to the previous commit, only using the 'add' or 'anno' prefixes
is confusing -- generally associated to the action of adding something,
or the Latin name for "year" -- and lack of uniformity.

This has been causing issues in the past, e.g. del_add_timer seemed to
suggest the goal is to delete a previously added timer.

Instead, use the mptcp_pm_announced_ prefix.

While at it, slightly improves some helpers:

- mptcp_lookup_anno_list_by_saddr: no need to specify what is used to do
  the lookup: mptcp_pm_announced_lookup.

- mptcp_pm_sport_in_anno_list: it doesn't just compare the port, but the
  whole address linked to the sublow: mptcp_pm_announced_has_ssk.

- mptcp_pm_alloc_anno_list: it allocates one item of the list, not a
  whole list: mptcp_pm_announced_alloc.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-11-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 15:33:38 -07:00
Matthieu Baerts (NGI0)
350d76dd6e mptcp: pm: rename add_entry structure to add_addr
Using only the 'add' prefix is confusing: does it refer to a generic
added entry or address, or specifically to ADD_ADDRs. Using add_addr
removes this confusion.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-10-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 15:33:38 -07:00
Matthieu Baerts (NGI0)
f816891724 mptcp: pm: use for_each_subflow helper
Similar to most places in the MPTCP code. So instead of passing the
subflow list and use list_for_each_entry(subflow, list, node), pass the
msk and use mptcp_for_each_subflow(msk, subflow).

That's clearer and more uniform with the rest.

While at it, add 'pm_' prefix for the exported one to easily identify
the origin. Plus replace 'lookup' by 'has', because a bool is returned.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-9-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 15:33:38 -07:00
Matthieu Baerts (NGI0)
23eeaad0d8 mptcp: pm: drop TCP TS with ADD_ADDRv6 + port
With TCP-timestamps (padded) taking 12 bytes and ADD_ADDR IPv6 + port
taking 30 bytes, the 40-byte limit for the TCP options is reached. In
this case, it is then not possible to send the signal.

To be able to send this ADD_ADDR, the TCP timestamps option can now be
dropped. This is done, when needed by setting the *drop_ts parameter
from mptcp_established_options. This feature is controlled by a new
net.mptcp.add_addr_v6_port_drop_ts sysctl knob, enabled by default.

It is important to keep in mind that dropping the TCP timestamps option
for one packet of the connection could eventually disrupt some
middleboxes: even if it should be unlikely, they could drop the packet
or even block the connection. That's why this new feature can be
controlled by a sysctl knob.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/448
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-6-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 15:33:38 -07:00
Matthieu Baerts (NGI0)
06c62385be mptcp: pm: avoid computing add_addr size twice
mptcp_add_addr_len helper was called twice: in mptcp_pm_add_addr_signal,
then just after in mptcp_established_options_add_addr. Both to check
the remaining space.

The second call is not needed: if there is not enough space,
mptcp_pm_add_addr_signal will return false, and the caller,
mptcp_established_options_add_addr, will do the same without re-checking
the size again. Instead, mptcp_pm_add_addr_signal can directly set the
size.

Note that the returned size can be negative when other suboptions are
dropped, e.g. to send an echo ADD_ADDR with a v4 address, and no port.

While at it:

 - move mptcp_add_addr_len to pm.c, as it is now only used from there

 - use 'int' in mptcp_add_addr_len for the size, instead of having a mix

 - use a bool for 'ret' in mptcp_pm_add_addr_signal

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-3-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 15:33:37 -07:00
Matthieu Baerts (NGI0)
a8bffec089 mptcp: pm: avoid computing rm_addr size twice
mptcp_rm_addr_len helper was called twice: in mptcp_pm_rm_addr_signal,
then just after in mptcp_established_options_rm_addr. Both to check the
remaining space.

The second call is not needed: if there is not enough space,
mptcp_pm_rm_addr_signal will return false, and the caller,
mptcp_established_options_rm_addr, will do the same without re-checking
the size again. Instead, mptcp_pm_rm_addr_signal can directly set the
size.

While at it, move mptcp_rm_addr_len to pm.c, as it is now only used
there, once.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-2-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 15:33:37 -07:00
Matthieu Baerts (NGI0)
bd34fa0257 mptcp: add-addr: always drop other suboptions
When an ADD_ADDR needs to be sent, it could be prepared if there is
enough remaining space and even if the packet is not a pure ACK. But it
would be dropped soon after.

Indeed, in mptcp_pm_add_addr_signal(), there is enough space to fit a
DSS of 20 octets and an ADD_ADDR echo containing an IPv4 address on 8
octets for example. In this case, the packet would be prepared, the
MPTCP_ADD_ADDR_ECHO bit would be removed from pm->addr_signal, but the
option would be silently dropped in mptcp_established_options_add_addr()
not to override DSS info in the union from 'struct mptcp_out_options',
and also because mptcp_write_options() will enforce mutually exclusion
with DSS.

Instead, don't even try to send an ADD_ADDR if it is not a pure ACK.
Retry for each new packet until a pure-ACK is emitted. That's fine to do
that, because each time an ADD_ADDR (echo) is scheduled, a pure ACK is
queued.

This also simplifies the code, and the skb checks can be done earlier,
before the lock.

Note: also, since commit 6d0060f600 ("mptcp: Write MPTCP DSS headers
to outgoing data packets"), opts->ahmac would not have been set to 0
when other suboptions were not dropped, and when sending an ADD_ADDR
echo. That would have resulted in sending an ADD_ADDR using garbage
info, where there was not enough space, instead of an echo one without
the ADD_ADDR HMAC.

Fixes: 1bff1e43a3 ("mptcp: optimize out option generation")
Cc: stable@vger.kernel.org
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-11-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:27 -07:00
Li Xiasong
51e398a3b8 mptcp: pm: fix ADD_ADDR timer infinite retry on option space insufficient
When TCP option space is insufficient (e.g., when sending ADD_ADDR with an
IPv6 address and port while tcp_timestamps is enabled), the original code
jumped to out_unlock without clearing the addr_signal flag. This caused
mptcp_pm_add_timer to keep rescheduling indefinitely, not sending ADD_ADDR,
preventing subsequent addresses in the endpoint list from being announced.

Handle this case by clearing the ADD_ADDR signal and skipping the matching
ADD_ADDR retransmission entry. The skip path cancels the matching timer
(with id check) and advances PM state progression, preserving forward
progress to subsequent PM work.

This cancellation is inherently best-effort. A concurrent add_timer
callback may already be running and may acquire pm.lock before the
cancel path updates entry state. In that case, one final ADD_ADDR
transmit attempt can still be executed.

Once the cancel path sets entry->retrans_times to ADD_ADDR_RETRANS_MAX,
the callback-side retrans_times check suppresses further ADD_ADDR
retransmissions.

Note that when an ADD_ADDR is being prepared, a pure-ACK is queued. On
the output side, it means that it is fine to skip non-pure-ACK packets,
when drop_other_suboptions is set: a pure-ACK will be processed soon
after.

Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Signed-off-by: Li Xiasong <lixiasong1@huawei.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260515-net-mptcp-misc-fixes-7-1-rc4-v2-2-701e96419f2f@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-19 15:36:35 +02:00
Matthieu Baerts (NGI0)
166b783440 mptcp: pm: prio: skip closed subflows
When sending an MP_PRIO, closed subflows need to be skipped.

This fixes the case where the initial subflow got closed, re-opened
later, then an MP_PRIO is needed for the same local address.

Note that explicit MP_PRIO cannot be sent during the 3WHS, so it is fine
to use __mptcp_subflow_active().

Fixes: 067065422f ("mptcp: add the outgoing MP_PRIO support")
Cc: stable@vger.kernel.org
Fixes: b29fcfb54c ("mptcp: full disconnect implementation")
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-9-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:45 -07:00
Matthieu Baerts (NGI0)
62a9b19dce mptcp: pm: ADD_ADDR rtx: return early if no retrans
No need to iterate over all subflows if there is no retransmission
needed.

Exit early in this case then.

Fixes: 30549eebc4 ("mptcp: make ADD_ADDR retransmission timeout adaptive")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-8-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:45 -07:00
Matthieu Baerts (NGI0)
c6d395e2de mptcp: pm: ADD_ADDR rtx: skip inactive subflows
When looking at the maximum RTO amongst the subflows, inactive subflows
were taken into account: that includes stale ones, and the initial one
if it has been already been closed.

Unusable subflows are now simply skipped. Stale ones are used as an
alternative: if there are only stale ones, to take their maximum RTO and
avoid to eventually fallback to net.mptcp.add_addr_timeout, which is set
to 2 minutes by default.

Fixes: 30549eebc4 ("mptcp: make ADD_ADDR retransmission timeout adaptive")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-7-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:45 -07:00
Matthieu Baerts (NGI0)
3cf1249289 mptcp: pm: ADD_ADDR rtx: resched blocked ADD_ADDR quicker
When an ADD_ADDR needs to be retransmitted and another one has already
been prepared -- e.g. multiple ADD_ADDRs have been sent in a row and
need to be retransmitted later -- this additional retransmission will
need to wait.

In this case, the timer was reset to TCP_RTO_MAX / 8, which is ~15
seconds. This delay is unnecessary long: it should just be rescheduled
at the next opportunity, e.g. after the retransmission timeout.

Without this modification, some issues can be seen from time to time in
the selftests when multiple ADD_ADDRs are sent, and the host takes time
to process them, e.g. the "signal addresses, ADD_ADDR timeout" MPTCP
Join selftest, especially with a debug kernel config.

Note that on older kernels, 'timeout' is not available. It should be
enough to replace it by one second (HZ).

Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-6-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:45 -07:00
Matthieu Baerts (NGI0)
b7b9a46156 mptcp: pm: ADD_ADDR rtx: free sk if last
When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer(),
and released at the end.

If at that moment, it was the last reference being held, the sk would
not be freed. sock_put() should then be called instead of __sock_put().

But that's not enough: if it is the last reference, sock_put() will call
sk_free(), which will end up calling sk_stop_timer_sync() on the same
timer, and waiting indefinitely to finish. So it is needed to mark that
the timer is done at the end of the timer handler when it has not been
rescheduled, not to call sk_stop_timer_sync() on "itself".

Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-5-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:44 -07:00
Matthieu Baerts (NGI0)
9634cb35af mptcp: pm: ADD_ADDR rtx: always decrease sk refcount
When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer().
It should then be released in all cases at the end.

Some (unlikely) checks were returning directly instead of calling
sock_put() to decrease the refcount. Jump to a new 'exit' label to call
__sock_put() (which will become sock_put() in the next commit) to fix
this potential leak.

While at it, drop the '!msk' check which cannot happen because it is
never reset, and explicitly mark the remaining one as "unlikely".

Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-4-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:44 -07:00
Matthieu Baerts (NGI0)
5cd6e0ad79 mptcp: pm: ADD_ADDR rtx: fix potential data-race
This mptcp_pm_add_timer() helper is executed as a timer callback in
softirq context. To avoid any data races, the socket lock needs to be
held with bh_lock_sock().

If the socket is in use, retry again soon after, similar to what is done
with the keepalive timer.

Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-3-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:44 -07:00
Matthieu Baerts (NGI0)
03f324f3f1 mptcp: pm: ADD_ADDR rtx: allow ID 0
ADD_ADDR can be sent for the ID 0, which corresponds to the local
address and port linked to the initial subflow.

Indeed, this address could be removed, and re-added later on, e.g. what
is done in the "delete re-add signal" MPTCP Join selftests. So no reason
to ignore it.

Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-2-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-06 18:16:44 -07:00
Matthieu Baerts (NGI0)
fb8d0bccb2 mptcp: pm: avoid sending RM_ADDR over same subflow
RM_ADDR are sent over an active subflow, the first one in the subflows
list. There is then a high chance the initial subflow is picked. With
the in-kernel PM, when an endpoint is removed, a RM_ADDR is sent, then
linked subflows are closed. This is done for each active MPTCP
connection.

MPTCP endpoints are likely removed because the attached network is no
longer available or usable. In this case, it is better to avoid sending
this RM_ADDR over the subflow that is going to be removed, but prefer
sending it over another active and non stale subflow, if any.

This modification avoids situations where the other end is not notified
when a subflow is no longer usable: typically when the endpoint linked
to the initial subflow is removed, especially on the server side.

Fixes: 8dd5efb1f9 ("mptcp: send ack for rm_addr")
Cc: stable@vger.kernel.org
Reported-by: Frank Lorenz <lorenz-frank@web.de>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/612
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260303-net-mptcp-misc-fixes-7-0-rc2-v1-2-4b5462b6f016@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-04 18:21:12 -08:00
Kees Cook
69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Paolo Abeni
2ca1b8926f mptcp: ensure the kernel PM does not take action too late
The PM hooks can currently take place when the msk is already shutting
down. Subflow creation will fail, thanks to the existing check at join
time, but we can entirely avoid starting the to be failed operations.

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/20251121-net-next-mptcp-memcg-backlog-imp-v1-7-1f34b6c1e0b1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-24 19:49:42 -08:00
Eric Dumazet
426358d9be mptcp: fix a race in mptcp_pm_del_add_timer()
mptcp_pm_del_add_timer() can call sk_stop_timer_sync(sk, &entry->add_timer)
while another might have free entry already, as reported by syzbot.

Add RCU protection to fix this issue.

Also change confusing add_timer variable with stop_timer boolean.

syzbot report:

BUG: KASAN: slab-use-after-free in __timer_delete_sync+0x372/0x3f0 kernel/time/timer.c:1616
Read of size 4 at addr ffff8880311e4150 by task kworker/1:1/44

CPU: 1 UID: 0 PID: 44 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events mptcp_worker
Call Trace:
 <TASK>
  dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
  print_address_description mm/kasan/report.c:378 [inline]
  print_report+0xca/0x240 mm/kasan/report.c:482
  kasan_report+0x118/0x150 mm/kasan/report.c:595
  __timer_delete_sync+0x372/0x3f0 kernel/time/timer.c:1616
  sk_stop_timer_sync+0x1b/0x90 net/core/sock.c:3631
  mptcp_pm_del_add_timer+0x283/0x310 net/mptcp/pm.c:362
  mptcp_incoming_options+0x1357/0x1f60 net/mptcp/options.c:1174
  tcp_data_queue+0xca/0x6450 net/ipv4/tcp_input.c:5361
  tcp_rcv_established+0x1335/0x2670 net/ipv4/tcp_input.c:6441
  tcp_v4_do_rcv+0x98b/0xbf0 net/ipv4/tcp_ipv4.c:1931
  tcp_v4_rcv+0x252a/0x2dc0 net/ipv4/tcp_ipv4.c:2374
  ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:205
  ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:239
  NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
  NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
  __netif_receive_skb_one_core net/core/dev.c:6079 [inline]
  __netif_receive_skb+0x143/0x380 net/core/dev.c:6192
  process_backlog+0x31e/0x900 net/core/dev.c:6544
  __napi_poll+0xb6/0x540 net/core/dev.c:7594
  napi_poll net/core/dev.c:7657 [inline]
  net_rx_action+0x5f7/0xda0 net/core/dev.c:7784
  handle_softirqs+0x22f/0x710 kernel/softirq.c:622
  __do_softirq kernel/softirq.c:656 [inline]
  __local_bh_enable_ip+0x1a0/0x2e0 kernel/softirq.c:302
  mptcp_pm_send_ack net/mptcp/pm.c:210 [inline]
 mptcp_pm_addr_send_ack+0x41f/0x500 net/mptcp/pm.c:-1
  mptcp_pm_worker+0x174/0x320 net/mptcp/pm.c:1002
  mptcp_worker+0xd5/0x1170 net/mptcp/protocol.c:2762
  process_one_work kernel/workqueue.c:3263 [inline]
  process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 44:
  kasan_save_stack mm/kasan/common.c:56 [inline]
  kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
  poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
  __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417
  kasan_kmalloc include/linux/kasan.h:262 [inline]
  __kmalloc_cache_noprof+0x1ef/0x6c0 mm/slub.c:5748
  kmalloc_noprof include/linux/slab.h:957 [inline]
  mptcp_pm_alloc_anno_list+0x104/0x460 net/mptcp/pm.c:385
  mptcp_pm_create_subflow_or_signal_addr+0xf9d/0x1360 net/mptcp/pm_kernel.c:355
  mptcp_pm_nl_fully_established net/mptcp/pm_kernel.c:409 [inline]
  __mptcp_pm_kernel_worker+0x417/0x1ef0 net/mptcp/pm_kernel.c:1529
  mptcp_pm_worker+0x1ee/0x320 net/mptcp/pm.c:1008
  mptcp_worker+0xd5/0x1170 net/mptcp/protocol.c:2762
  process_one_work kernel/workqueue.c:3263 [inline]
  process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 6630:
  kasan_save_stack mm/kasan/common.c:56 [inline]
  kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
  __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587
  kasan_save_free_info mm/kasan/kasan.h:406 [inline]
  poison_slab_object mm/kasan/common.c:252 [inline]
  __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
  kasan_slab_free include/linux/kasan.h:234 [inline]
  slab_free_hook mm/slub.c:2523 [inline]
  slab_free mm/slub.c:6611 [inline]
  kfree+0x197/0x950 mm/slub.c:6818
  mptcp_remove_anno_list_by_saddr+0x2d/0x40 net/mptcp/pm.c:158
  mptcp_pm_flush_addrs_and_subflows net/mptcp/pm_kernel.c:1209 [inline]
  mptcp_nl_flush_addrs_list net/mptcp/pm_kernel.c:1240 [inline]
  mptcp_pm_nl_flush_addrs_doit+0x593/0xbb0 net/mptcp/pm_kernel.c:1281
  genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115
  genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
  genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
  netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
  genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
  netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
  netlink_unicast+0x846/0xa10 net/netlink/af_netlink.c:1346
  netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
  sock_sendmsg_nosec net/socket.c:727 [inline]
  __sock_sendmsg+0x21c/0x270 net/socket.c:742
  ____sys_sendmsg+0x508/0x820 net/socket.c:2630
  ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
  __sys_sendmsg net/socket.c:2716 [inline]
  __do_sys_sendmsg net/socket.c:2721 [inline]
  __se_sys_sendmsg net/socket.c:2719 [inline]
  __x64_sys_sendmsg+0x1a1/0x260 net/socket.c:2719
  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
  do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Cc: stable@vger.kernel.org
Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Reported-by: syzbot+2a6fbf0f0530375968df@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/691ad3c3.a70a0220.f6df1.0004.GAE@google.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Geliang Tang <geliang@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251117100745.1913963-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-18 18:33:01 -08:00
Matthieu Baerts (NGI0)
e7757b6d3a mptcp: pm: in-kernel: rename 'local_addr_max' to 'endp_subflow_max'
A few variables linked to the in-kernel Path-Manager are confusing, and
it would help current and future developers, to clarify them.

One of them is 'local_addr_max', which in fact represents the maximum
number of 'subflow' endpoints that can be used to create new subflows,
and not the number of local addresses that have been used to create
subflows.

While at it, add an additional name for the corresponding variable in
MPTCP INFO: mptcpi_endp_subflow_max. Not to break the current uAPI, the
new name is added as a 'define' pointing to the former name. This will
then also help userspace devs.

Also move the variable and function next to the other 'endp_X_max' ones.

No functional changes intended.

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-v1-9-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:05 -07:00
Matthieu Baerts (NGI0)
37712d84df mptcp: pm: in-kernel: rename 'add_addr_accept_max' to 'limit_add_addr_accepted'
A few variables linked to the in-kernel Path-Manager are confusing, and
it would help current and future developers, to clarify them.

One of them is 'add_addr_accept_max', which in fact represents the limit
of ADD_ADDR that can be accepted:  the limit set via 'ip mptcp limit
add_addr_accepted X' for example. It is not linked to the maximum number
of accepted ADD_ADDR.

While at it, add an additional name for the corresponding variable in
MPTCP INFO: mptcpi_limit_add_addr_accepted. Not to break the current
uAPI, the new name is added as a 'define' pointing to the former name.
This will then also help userspace devs.

No functional changes intended.

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-v1-8-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:04 -07:00
Matthieu Baerts (NGI0)
45cae57066 mptcp: pm: in-kernel: rename 'add_addr_signal_max' to 'endp_signal_max'
A few variables linked to the in-kernel Path-Manager are confusing, and
it would help current and future developers, to clarify them.

One of them is 'add_addr_signal_max', which in fact represents the
maximum number of 'signal' endpoints that can be used to announced
addresses, and not the number of ADD_ADDR that can be signalled.

While at it, add an additional name for the corresponding variable in
MPTCP INFO: mptcpi_endp_signal_max. Not to break the current uAPI, the
new name is added as a 'define' pointing to the former name. This will
then also help userspace devs.

No functional changes intended.

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-v1-7-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:04 -07:00
Matthieu Baerts (NGI0)
3eb3c9a959 mptcp: pm: in-kernel: rename 'subflows_max' to 'limit_extra_subflows'
A few variables linked to the in-kernel Path-Manager are confusing, and
it would help current and future developers, to clarify them.

One of them is 'subflows_max', which in fact represents the limit of
extra subflows: the limit set via 'ip mptcp limit subflows X' for
example. It is not linked to the maximum number of created / possible
subflows.

While at it, add an additional name for the corresponding variable in
MPTCP INFO: mptcpi_limit_extra_subflows. Not to break the current uAPI,
the new name is added as a 'define' pointing to the former name. This
will then also help userspace devs.

No functional changes intended.

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-v1-6-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:04 -07:00
Matthieu Baerts (NGI0)
c5273f6ca1 mptcp: pm: rename 'subflows' to 'extra_subflows'
A few variables linked to the Path-Managers are confusing, and it would
help current and future developers, to clarify them.

One of them is 'subflows', which in fact represents the number of extra
subflows: all the additional subflows created after the initial one, and
not the total number of subflows.

While at it, add an additional name for the corresponding variable in
MPTCP INFO: mptcpi_extra_subflows. Not to break the current uAPI, the
new name is added as a 'define' pointing to the former name. This will
then also help userspace devs.

No functional changes intended.

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-v1-5-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-26 17:44:04 -07:00
Matthieu Baerts (NGI0)
4b1ff850e0 mptcp: pm: in-kernel: usable client side with C-flag
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>
2025-09-26 17:44:03 -07:00
Geliang Tang
30549eebc4 mptcp: make ADD_ADDR retransmission timeout adaptive
Currently the ADD_ADDR option is retransmitted with a fixed timeout. This
patch makes the retransmission timeout adaptive by using the maximum RTO
among all the subflows, while still capping it at the configured maximum
value (add_addr_timeout_max). This improves responsiveness when
establishing new subflows.

Specifically:
1. Adds mptcp_adjust_add_addr_timeout() helper to compute the adaptive
timeout.
2. Uses maximum subflow RTO (icsk_rto) when available.
3. Applies exponential backoff based on retransmission count.
4. Maintains fallback to configured max timeout when no RTO data exists.

This slightly changes the behaviour of the MPTCP "add_addr_timeout"
sysctl knob to be used as a maximum instead of a fixed value. But this
is seen as an improvement: the ADD_ADDR might be sent quicker than
before to improve the overall MPTCP connection. Also, the default
value is set to 2 min, which was already way too long, and caused the
ADD_ADDR not to be retransmitted for connections shorter than 2 minutes.

Suggested-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/576
Reviewed-by: Christoph Paasch <cpaasch@openai.com>
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/20250907-net-next-mptcp-add_addr-retrans-adapt-v1-1-824cc805772b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-09 18:57:45 -07:00
Geliang Tang
f5ce071462 mptcp: disable add_addr retransmission when timeout is 0
When add_addr_timeout was set to 0, this caused the ADD_ADDR to be
retransmitted immediately, which looks like a buggy behaviour. Instead,
interpret 0 as "no retransmissions needed".

The documentation is updated to explicitly state that setting the timeout
to 0 disables retransmission.

Fixes: 93f323b9cc ("mptcp: add a new sysctl add_addr_timeout")
Cc: stable@vger.kernel.org
Suggested-by: Matthieu Baerts <matttbe@kernel.org>
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/20250815-net-mptcp-misc-fixes-6-17-rc2-v1-5-521fe9957892@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-18 17:39:58 -07:00
Geliang Tang
5d13349472 mptcp: remove duplicate sk_reset_timer call
sk_reset_timer() was called twice in mptcp_pm_alloc_anno_list.

Simplify the code by using a 'goto' statement to eliminate the
duplication.

Note that this is not a fix, but it will help backporting the following
patch. The same "Fixes" tag has been added for this reason.

Fixes: 93f323b9cc ("mptcp: add a new sysctl add_addr_timeout")
Cc: stable@vger.kernel.org
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/20250815-net-mptcp-misc-fixes-6-17-rc2-v1-4-521fe9957892@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-18 17:39:58 -07:00
Paolo Abeni
def5b7b264 mptcp: plug races between subflow fail and subflow creation
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>
2025-07-15 17:31:25 -07:00
Ingo Molnar
41cb08555c treewide, timers: Rename from_timer() to timer_container_of()
Move this API to the canonical timer_*() namespace.

[ tglx: Redone against pre rc1 ]

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
2025-06-08 09:07:37 +02:00
Thorsten Blum
def9d0958b mptcp: pm: Return local variable instead of freed pointer
Commit e4c28e3d5c ("mptcp: pm: move generic PM helpers to pm.c")
removed an unnecessary if-check, which resulted in returning a freed
pointer.

This still works due to the implicit boolean conversion when returning
the freed pointer from mptcp_remove_anno_list_by_saddr(), but it can be
confusing and potentially error-prone. To improve clarity, add a local
variable to explicitly return a boolean value instead.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250413-net-next-mptcp-sched-mib-sft-misc-v2-3-0f83a4350150@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-15 08:21:46 -07:00
Thomas Gleixner
8fa7292fee treewide: Switch/rename to timer_delete[_sync]()
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.

Conversion was done with coccinelle plus manual fixups where necessary.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-05 10:30:12 +02:00
Geliang Tang
fa3ee9dd80 mptcp: sysctl: add available_path_managers
Similarly to net.mptcp.available_schedulers, this patch adds a new one
net.mptcp.available_path_managers to list the available path managers.

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-v1-11-f4e4a88efc50@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-20 10:14:49 +01:00
Geliang Tang
770170b418 mptcp: pm: register in-kernel and userspace PM
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>
2025-03-20 10:14:48 +01:00
Geliang Tang
1305b0c22e mptcp: pm: define struct mptcp_pm_ops
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>
2025-03-20 10:14:48 +01:00
Geliang Tang
eff5b1578e mptcp: pm: add struct_group in mptcp_pm_data
This patch adds a "struct_group(reset, ...)" in struct mptcp_pm_data to
simplify the reset, and make sure we don't miss any.

Suggested-by: Matthieu Baerts <matttbe@kernel.org>
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-v1-5-f4e4a88efc50@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-20 10:14:48 +01:00
Geliang Tang
98a0a99e81 mptcp: pm: only fill id_avail_bitmap for in-kernel pm
id_avail_bitmap of struct mptcp_pm_data is currently only used by the
in-kernel PM, so this patch moves its initialization operation under
the "if (pm_type == MPTCP_PM_TYPE_KERNEL)" condition.

Suggested-by: Matthieu Baerts <matttbe@kernel.org>
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-v1-4-f4e4a88efc50@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-20 10:14:48 +01:00
Geliang Tang
5fff36b69c mptcp: pm: use pm variable instead of msk->pm
The variable "pm" has been defined in mptcp_pm_fully_established()
and mptcp_pm_data_reset() as "msk->pm", so use "pm" directly instead
of using "msk->pm".

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-v1-3-f4e4a88efc50@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-20 10:14:48 +01:00
Matthieu Baerts (NGI0)
b97d6b6820 mptcp: pm: split netlink and in-kernel init
The registration of mptcp_genl_family is useful for both the in-kernel
and the userspace PM. It should then be done in pm_netlink.c.

On the other hand, the registration of the in-kernel pernet subsystem is
specific to the in-kernel PM, and should stay there in pm_kernel.c.

Reviewed-by: Mat Martineau <martineau@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-v1-1-f4e4a88efc50@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-20 10:14:48 +01:00
Matthieu Baerts (NGI0)
2e7e6e9cda mptcp: pm: move Netlink PM helpers to pm_netlink.c
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>
2025-03-10 13:35:50 -07:00
Matthieu Baerts (NGI0)
e4c28e3d5c mptcp: pm: move generic PM helpers to pm.c
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>
2025-03-10 13:35:50 -07:00
Matthieu Baerts (NGI0)
bcc32640ad mptcp: pm: move generic helper at the top
In prevision to another change importing all generic PM helpers from
pm_netlink.c to there.

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-v1-12-abef20ada03b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-10 13:35:50 -07:00
Matthieu Baerts (NGI0)
a49eb8ae95 mptcp: pm: worker: split in-kernel and common tasks
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>
2025-03-10 13:35:49 -07:00
Matthieu Baerts (NGI0)
a17336b2b2 mptcp: pm: avoid calling PM specific code from core
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>
2025-03-10 13:35:49 -07:00
Matthieu Baerts (NGI0)
498d7d8b75 mptcp: pm: remove '_nl' from mptcp_pm_nl_is_init_remote_addr
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>
2025-03-10 13:35:49 -07:00
Matthieu Baerts (NGI0)
550c50bbc2 mptcp: pm: remove '_nl' from mptcp_pm_nl_subflow_chk_stale()
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>
2025-03-10 13:35:49 -07:00