The userspace PM increments extra_subflows after __mptcp_subflow_connect()
succeeds, but __mptcp_subflow_connect() calls mptcp_pm_close_subflow()
on failure to roll back the pre-increment done by the kernel PM's fill_*()
helpers. Because the userspace PM hasn't incremented yet at that point,
this decrement is spurious and causes extra_subflows to underflow.
Fix it by aligning the userspace PM with the kernel PM: increment
extra_subflows before calling __mptcp_subflow_connect(), so the existing
error path in subflow.c correctly rolls it back on failure. Also simplify
the error handling by taking pm.lock only when needed for cleanup.
Fixes: 77e4b94a3d ("mptcp: update userspace pm infos")
Cc: stable@vger.kernel.org
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-5-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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>
When path manager entries are deleted from the local address list, they
are first unlinked from the address list using list_del_rcu(). The
entries must not be freed until after the RCU grace period, but the
existing code immediately frees the entry.
Use kfree_rcu_mightsleep() and adjust sk_omem_alloc in open code instead
of using the sock_kfree_s() helper. This code path is only called in a
netlink handler, so the "might sleep" function is preferable to adding
a rarely-used rcu_head member to struct mptcp_pm_addr_entry.
Fixes: 88d0973163 ("mptcp: drop free_list for deleting entries")
Cc: stable@vger.kernel.org
Signed-off-by: Mat Martineau <martineau@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250421-net-mptcp-pm-defer-freeing-v1-1-e731dc6e86b9@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>
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>
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>
Instead of using sock_kmalloc() to allocate an address
entry "e" and then immediately duplicate the input "entry"
to it, the newly added sock_kmemdup() helper can be used in
mptcp_userspace_pm_append_new_local_addr() to simplify the code.
More importantly, the code "*e = *entry;" that assigns "entry"
to "e" is not easy to implemented in BPF if we use the same code
to implement an append_new_local_addr() helper of a BFP path
manager. This patch avoids this type of memory assignment
operation.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/3e5a307aed213038a87e44ff93b5793229b16279.1740735165.git.tanggeliang@kylinos.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The variable 'match' in mptcp_userspace_pm_append_new_local_addr() is a
redundant one, and this patch drops it.
No need to define 'match' as 'struct mptcp_pm_addr_entry *' type. In this
function, it's only used to check whether it's NULL. It can be defined as
a Boolean one.
Also other variables 'addr_match' and 'id_match' make 'match' a redundant
one, which can be replaced by directly checking 'addr_match && id_match'.
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/20250221-net-next-mptcp-pm-misc-cleanup-3-v1-5-2b70ab1cee79@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>
Generally, in the path manager interfaces, the local address is defined
as an mptcp_pm_addr_entry type address, while the remote address is
defined as an mptcp_addr_info type one:
(struct mptcp_pm_addr_entry *local, struct mptcp_addr_info *remote)
But the set_flags() interface uses two mptcp_pm_addr_entry type
parameters.
This patch changes the second one to mptcp_addr_info type and use helper
mptcp_pm_parse_addr() to parse it instead of using mptcp_pm_parse_entry().
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>
Instead of only returning a text message with GENL_SET_ERR_MSG(),
NL_SET_ERR_MSG_ATTR() can help the userspace developers by also
reporting which attribute is faulty.
When the error is specific to an attribute, NL_SET_ERR_MSG_ATTR() is now
used. The error messages have not been modified in this commit.
Reviewed-by: Geliang Tang <geliang@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_parse_entry() will check if the given attribute is defined. If
not, it will return a generic error: "missing address info".
It might then not be clear for the userspace developer which attribute
is missing, especially when the command takes multiple addresses.
By using GENL_REQ_ATTR_CHECK(), the userspace will get a hint about
which attribute is missing, making thing clearer. Note that this is what
was already done for most of the other MPTCP NL commands, this patch
simply adds the missing ones.
Reviewed-by: Geliang Tang <geliang@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_parse_entry() and mptcp_pm_parse_addr() will already set a
error message in case of parsing issue.
Then, no need to override this error message with another less precise
one: "error parsing address".
Reviewed-by: Geliang Tang <geliang@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>
A more general way to check if MPTCP_PM_ATTR_* exists in 'info'
is to use GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_*) instead of
directly reading info->attrs[MPTCP_PM_ATTR_*] and then checking
if it's NULL.
So this patch uses GENL_REQ_ATTR_CHECK() for userspace PM in
mptcp_pm_nl_announce_doit(), mptcp_pm_nl_remove_doit(),
mptcp_pm_nl_subflow_create_doit(), mptcp_pm_nl_subflow_destroy_doit()
and mptcp_userspace_pm_get_sock().
Suggested-by: Jakub Kicinski <kuba@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>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Some error messages were:
- too generic: "missing input", "invalid request"
- not precise enough: "limit greater than maximum" but what's the max?
- missing: subflow not found, or connect error.
This can be easily improved by being more precise, or adding new error
messages.
Reviewed-by: Geliang Tang <geliang@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>
Some errors reported by the userspace PM were vague: "this or that is
invalid".
It is easier for the userspace to know which part is wrong, instead of
having to guess that.
While at it, in mptcp_userspace_pm_set_flags() move the parsing after
the check linked to the local attribute.
Reviewed-by: Geliang Tang <geliang@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>
