This attribute is a boolean. No need to add it to set it to 'false'.
Indeed, the default value when this attribute is not set is naturally
'false'. A few bytes can then be saved by not adding this attribute if
the connection is not on the server side.
This prepares the future deprecation of its attribute, in favour of a
new flag.
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250919-net-next-mptcp-server-side-flag-v1-1-a97a5d561a8b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
During the connection establishment, a peer can tell the other one that
it cannot establish new subflows to the initial IP address and port by
setting the 'C' flag [1]. Doing so makes sense when the sender is behind
a strict NAT, operating behind a legacy Layer 4 load balancer, or using
anycast IP address for example.
When this 'C' flag is set, the path-managers must then not try to
establish new subflows to the other peer's initial IP address and port.
The in-kernel PM has access to this info, but the userspace PM didn't.
The RFC8684 [1] is strict about that:
(...) therefore the receiver MUST NOT try to open any additional
subflows toward this address and port.
So it is important to tell the userspace about that as it is responsible
for the respect of this flag.
When a new connection is created and established, the Netlink events
now contain the existing but not currently used 'flags' attribute. When
MPTCP_PM_EV_FLAG_DENY_JOIN_ID0 is set, it means no other subflows
to the initial IP address and port -- info that are also part of the
event -- can be established.
Link: https://datatracker.ietf.org/doc/html/rfc8684#section-3.1-20.6 [1]
Fixes: 702c2f646d ("mptcp: netlink: allow userspace-driven subflow establishment")
Reported-by: Marek Majkowski <marek@cloudflare.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/532
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250912-net-mptcp-pm-uspace-deny_join_id0-v1-2-40171884ade8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We're trying to add a strict regexp for the name format in the spec.
Underscores will not be allowed, dashes should be used instead.
This makes no difference to C (codegen, if used, replaces special
chars in names) but it gives more uniform naming in Python.
Fixes: bc8aeb2045 ("Documentation: netlink: add a YAML spec for mptcp")
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250624211002.3475021-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The rendered version of the MPTCP events [1] looked strange, because the
whole content of the 'doc' was displayed in the same block.
It was then not clear that the first words, not even ended by a period,
were the attributes that are defined when such events are emitted. These
attributes have now been moved to the end, prefixed by 'Attributes:' and
ended with a period. Note that '>-' has been added after 'doc:' to allow
':' in the text below.
The documentation in the UAPI header has been auto-generated by:
./tools/net/ynl/ynl-regen.sh
Link: https://docs.kernel.org/networking/netlink_spec/mptcp_pm.html#event-type [1]
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241221-net-mptcp-netlink-specs-pm-doc-fixes-v2-2-e54f2db3f844@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This attribute is added with the 'created' and 'established' events, but
the documentation didn't mention it.
The documentation in the UAPI header has been auto-generated by:
./tools/net/ynl/ynl-regen.sh
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241221-net-mptcp-netlink-specs-pm-doc-fixes-v2-1-e54f2db3f844@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We assume in handful of places that the name of the spec is
the same as the name of the family. We could fix that but
it seems like a fair assumption to make. Rename the MPTCP
spec instead.
Reviewed-by: Mat Martineau <martineau@kernel.org>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
allow specifying cmd-cnt-name and cmd-max-name in netlink specs, in
accordance with Documentation/userspace-api/netlink/c-code-gen.rst.
Use cmd-cnt-name and attr-cnt-name in the mptcp yaml spec and in the
corresponding uAPI headers, to preserve the #defines we had in the past
and avoid adding new ones.
v2:
- squash modification in mptcp.yaml and MPTCP uAPI headers
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/12d4ed0116d8883cf4b533b856f3125a34e56749.1698415310.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Matthieu Baerts (NGI0)