mptcp: drop lookup_by_id in lookup_addr

When the lookup_by_id parameter of __lookup_addr() is true, it's the same
as __lookup_addr_by_id(), it can be replaced by __lookup_addr_by_id()
directly. So drop this parameter, let __lookup_addr() only looks up address
on the local address list by comparing addresses in it, not address ids.

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://lore.kernel.org/r/20240305-upstream-net-next-20240304-mptcp-misc-cleanup-v1-4-c436ba5e569b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: set error messages for set_flags

In addition to returning the error value, this patch also sets an error
messages with GENL_SET_ERR_MSG or NL_SET_ERR_MSG_ATTR both for pm_netlink.c
and pm_userspace.c. It will help the userspace to identify the issue.

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://lore.kernel.org/r/20240305-upstream-net-next-20240304-mptcp-misc-cleanup-v1-3-c436ba5e569b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: update set_flags interfaces

This patch updates set_flags interfaces, make it more similar to the
interfaces of dump_addr and get_addr:

mptcp_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info)
mptcp_userspace_pm_set_flags(struct sk_buff *skb, struct genl_info *info)

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://lore.kernel.org/r/20240305-upstream-net-next-20240304-mptcp-misc-cleanup-v1-2-c436ba5e569b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: drop duplicate header inclusions

The headers net/tcp.h, net/genetlink.h and uapi/linux/mptcp.h are included
in protocol.h already, no need to include them again directly. This patch
removes these duplicate header inclusions.

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://lore.kernel.org/r/20240305-upstream-net-next-20240304-mptcp-misc-cleanup-v1-1-c436ba5e569b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: get addr in userspace pm list

This patch renames mptcp_pm_nl_get_addr_doit() as a dedicated in-kernel
netlink PM get addr function mptcp_pm_nl_get_addr(). and invoke a new
wrapper mptcp_pm_get_addr() in mptcp_pm_nl_get_addr_doit.

If a token is gotten in the wrapper, that means a userspace PM is used.
So invoke mptcp_userspace_pm_get_addr() to get addr in userspace PM list.
Otherwise, invoke mptcp_pm_nl_get_addr().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: dump addrs in userspace pm list

This patch renames mptcp_pm_nl_get_addr_dumpit() as a dedicated in-kernel
netlink PM dump addrs function mptcp_pm_nl_dump_addr(), and invoke a newly
added wrapper mptcp_pm_dump_addr() in mptcp_pm_nl_get_addr_dumpit().

Invoke in-kernel PM dump addrs function mptcp_pm_nl_dump_addr() or
userspace PM dump addrs function mptcp_userspace_pm_dump_addr() based on
whether the token parameter is passed in or not in the wrapper.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: export mptcp_genl_family & mptcp_nl_fill_addr

This patch exports struct mptcp_genl_family and mptcp_nl_fill_addr() helper
to allow them can be used in pm_userspace.c.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: make pm_remove_addrs_and_subflows static

mptcp_pm_remove_addrs_and_subflows() is only used in pm_netlink.c, it's
no longer used in pm_userspace.c any more since the commit 8b1c94da1e48
("mptcp: only send RM_ADDR in nl_cmd_remove"). So this patch changes it
to a static function.

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>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: annotate lockless access for token

The token field is manipulated under the msk socket lock
and accessed lockless in a few spots, add proper ONCE annotation

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix duplicate subflow creation

Fullmesh endpoints could end-up unexpectedly generating duplicate
subflows - same local and remote addresses - when multiple incoming
ADD_ADDR are processed before the PM creates the subflow for the local
endpoints.

Address the issue explicitly checking for duplicates at subflow
creation time.

To avoid a quadratic computational complexity, track the unavailable
remote address ids in a temporary bitmap and initialize such bitmap
with the remote ids of all the existing subflows matching the local
address currently processed.

The above allows additionally replacing the existing code checking
for duplicate entry in the current set with a simple bit test
operation.

Fixes: 2843ff6f36db ("mptcp: remote addresses fullmesh")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/435
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix data races on remote_id

Similar to the previous patch, address the data race on
remote_id, adding the suitable ONCE annotations.

Fixes: bedee0b56113 ("mptcp: address lookup improvements")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix data races on local_id

The local address id is accessed lockless by the NL PM, add
all the required ONCE annotation. There is a caveat: the local
id can be initialized late in the subflow life-cycle, and its
validity is controlled by the local_id_valid flag.

Remove such flag and encode the validity in the local_id field
itself with negative value before initialization. That allows
accessing the field consistently with a single read operation.

Fixes: 0ee4261a3681 ("mptcp: implement mptcp_pm_remove_subflow")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add needs_id for netlink appending addr

Just the same as userspace PM, a new parameter needs_id is added for
in-kernel PM mptcp_pm_nl_append_new_local_addr() too.

Add a new helper mptcp_pm_has_addr_attr_id() to check whether an address
ID is set from PM or not.

In mptcp_pm_nl_get_local_id(), needs_id is always true, but in
mptcp_pm_nl_add_addr_doit(), pass mptcp_pm_has_addr_attr_id() to
needs_it.

Fixes: efd5a4c04e18 ("mptcp: add the address ID assignment bitmap")
Cc: stable@vger.kernel.org
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: use mptcp_set_state

This patch replaces all the 'inet_sk_state_store()' calls under net/mptcp
with the new helper mptcp_set_state().

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/460
Signed-off-by: Geliang Tang <geliang.tang@linux.dev>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

genetlink: Use internal flags for multicast groups

As explained in commit e03781879a0d ("drop_monitor: Require
'CAP_SYS_ADMIN' when joining "events" group"), the "flags" field in the
multicast group structure reuses uAPI flags despite the field not being
exposed to user space. This makes it impossible to extend its use
without adding new uAPI flags, which is inappropriate for internal
kernel checks.

Solve this by adding internal flags (i.e., "GENL_MCAST_*") and convert
the existing users to use them instead of the uAPI flags.

Tested using the reproducers in commit 44ec98ea5ea9 ("psample: Require
'CAP_NET_ADMIN' when joining "packets" group") and commit e03781879a0d
("drop_monitor: Require 'CAP_SYS_ADMIN' when joining "events" group").

No functional changes intended.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add validity check for sending RM_ADDR

This patch adds the validity check for sending RM_ADDRs for userspace PM
in mptcp_pm_remove_addrs(), only send a RM_ADDR when the address is in the
anno_list or conn_list.

Fixes: 8b1c94da1e48 ("mptcp: only send RM_ADDR in nl_cmd_remove")
Cc: stable@vger.kernel.org
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20231114-upstream-net-20231113-mptcp-misc-fixes-6-7-rc2-v1-3-7b9cd6a7b7f4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: mptcp: use policy generated by YAML spec

generated with:

$ ./tools/net/ynl/ynl-gen-c.py --mode kernel \
> --spec Documentation/netlink/specs/mptcp.yaml --source \
> -o net/mptcp/mptcp_pm_gen.c
$ ./tools/net/ynl/ynl-gen-c.py --mode kernel \
> --spec Documentation/netlink/specs/mptcp.yaml --header \
> -o net/mptcp/mptcp_pm_gen.h

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/340
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-1-v2-7-16b1f701f900@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: mptcp: rename netlink handlers to mptcp_pm_nl_<blah>_{doit,dumpit}

so that they will match names generated from YAML spec.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/340
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-1-v2-6-16b1f701f900@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: mptcp: convert netlink from small_ops to ops

in the current MPTCP control plane, all operations use a netlink
attribute of the same type "MPTCP_PM_ATTR". However, add/del/get/flush
operations only parse the first element in the message _ the one that
describes MPTCP endpoints (that was named MPTCP_PM_ATTR_ADDR and
mostly used in ADD_ADDR operations _ probably the similarity of "attr",
"addr" and "add" might cause some confusion to human readers).
Convert MPTCP from 'small_ops' to 'ops', thus allowing different attributes
for each single operation, hopefully makes all this clearer to human
readers.

- use a separate attribute set for add/del/get/flush address operation,
binary compatible with the existing one, to store the endpoint address.
MPTCP_PM_ENDPOINT_ADDR is added to the uAPI (with the same value as
MPTCP_PM_ATTR_ADDR) for these operations.
- convert mptcp_pm_ops[] and add policy files accordingly.

this prepares MPTCP control plane to be described as YAML spec.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/340
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-1-v2-3-16b1f701f900@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: drop last_snd and MPTCP_RESET_SCHEDULER

Since the burst check conditions have moved out of the function
mptcp_subflow_get_send(), it makes all msk->last_snd useless.
This patch drops them as well as the macro MPTCP_RESET_SCHEDULER.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20230821-upstream-net-next-20230818-v1-2-0c860fb256a8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: change the mpc check helper to return a sk

After the previous patch the __mptcp_nmpc_socket helper is used
only to ensure that the MPTCP socket is a suitable status - that
is, the mptcp capable handshake is not started yet.

Change the return value to the relevant subflow sock, to finally
remove the last references to first subflow socket in the MPTCP stack.

As a bonus, we can get rid of a few local variables in different
functions.

No functional change intended.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: avoid ssock usage in mptcp_pm_nl_create_listen_socket()

This is one of the few remaining spots actually manipulating the
first subflow socket. We can leverage the recently introduced
inet helpers to get rid of ssock there.

No functional changes intended.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: pass addr to mptcp_pm_alloc_anno_list

Pass addr parameter to mptcp_pm_alloc_anno_list() instead of entry. We
can reduce the scope, e.g. in mptcp_pm_alloc_anno_list(), we only access
"entry->addr", we can then restrict to the pointer to "addr" then.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: ensure listener is unhashed before updating the sk status

The MPTCP protocol access the listener subflow in a lockless
manner in a couple of places (poll, diag). That works only if
the msk itself leaves the listener status only after that the
subflow itself has been closed/disconnected. Otherwise we risk
deadlock in diag, as reported by Christoph.

Address the issue ensuring that the first subflow (the listener
one) is always disconnected before updating the msk socket status.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/407
Fixes: b29fcfb54cd7 ("mptcp: full disconnect implementation")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: Reorder fields in 'struct mptcp_pm_add_entry'

Group some variables based on their sizes to reduce hole and avoid padding.
On x86_64, this shrinks the size of 'struct mptcp_pm_add_entry'
from 136 to 128 bytes.

It saves a few bytes of memory and is more cache-line friendly.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/e47b71de54fd3e580544be56fc1bb2985c77b0f4.1687081558.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: unify pm set_flags interfaces

This patch unifies the three PM set_flags() interfaces:

mptcp_pm_nl_set_flags() in mptcp/pm_netlink.c for the in-kernel PM and
mptcp_userspace_pm_set_flags() in mptcp/pm_userspace.c for the
userspace PM.

They'll be switched in the common PM infterface mptcp_pm_set_flags() in
mptcp/pm.c based on whether token is NULL or not.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: unify pm get_flags_and_ifindex_by_id

This patch unifies the three PM get_flags_and_ifindex_by_id() interfaces:

mptcp_pm_nl_get_flags_and_ifindex_by_id() in mptcp/pm_netlink.c for the
in-kernel PM and mptcp_userspace_pm_get_flags_and_ifindex_by_id() in
mptcp/pm_userspace.c for the userspace PM.

They'll be switched in the common PM infterface
mptcp_pm_get_flags_and_ifindex_by_id() in mptcp/pm.c based on whether
mptcp_pm_is_userspace() or not.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: unify pm get_local_id interfaces

This patch unifies the three PM get_local_id() interfaces:

mptcp_pm_nl_get_local_id() in mptcp/pm_netlink.c for the in-kernel PM and
mptcp_userspace_pm_get_local_id() in mptcp/pm_userspace.c for the
userspace PM.

They'll be switched in the common PM infterface mptcp_pm_get_local_id()
in mptcp/pm.c based on whether mptcp_pm_is_userspace() or not.

Also put together the declarations of these three functions in protocol.h.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: export local_address

Rename local_address() with "mptcp_" prefix and export it in protocol.h.

This function will be re-used in the common PM code (pm.c) in the
following commit.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: only send RM_ADDR in nl_cmd_remove

The specifications from [1] about the "REMOVE" command say:

Announce that an address has been lost to the peer

It was then only supposed to send a RM_ADDR and not trying to delete
associated subflows.

A new helper mptcp_pm_remove_addrs() is then introduced to do just
that, compared to mptcp_pm_remove_addrs_and_subflows() also removing
subflows.

To delete a subflow, the userspace daemon can use the "SUB_DESTROY"
command, see mptcp_nl_cmd_sf_destroy().

Fixes: d9a4594edabf ("mptcp: netlink: Add MPTCP_PM_CMD_REMOVE")
Link: https://github.com/multipath-tcp/mptcp/blob/mptcp_v0.96/include/uapi/linux/mptcp.h [1]
Cc: stable@vger.kernel.org
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: move first subflow allocation at mpc access time

In the long run this will simplify the mptcp code and will
allow for more consistent behavior. Move the first subflow
allocation out of the sock->init ops into the __mptcp_nmpc_socket()
helper.

Since the first subflow creation can now happen after the first
setsockopt() we additionally need to invoke mptcp_sockopt_sync()
on it.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: annotate lockless accesses to sk->sk_err

mptcp_poll() reads sk->sk_err without socket lock held/owned.

Add READ_ONCE() and WRITE_ONCE() to avoid load/store tearing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix lockdep false positive in mptcp_pm_nl_create_listen_socket()

Christoph reports a lockdep splat in the mptcp_subflow_create_socket()
error path, when such function is invoked by
mptcp_pm_nl_create_listen_socket().

Such code path acquires two separates, nested socket lock, with the
internal lock operation lacking the "nested" annotation. Adding that
in sock_release() for mptcp's sake only could be confusing.

Instead just add a new lockclass to the in-kernel msk socket,
re-initializing the lockdep infra after the socket creation.

Fixes: ad2171009d96 ("mptcp: fix locking for in-kernel listener creation")
Cc: stable@vger.kernel.org
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/354
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: let the in-kernel PM use mixed IPv4 and IPv6 addresses

Currently the in-kernel PM arbitrary enforces that created subflow's
family must match the main MPTCP socket while the RFC allows mixing
IPv4 and IPv6 subflows.

This patch changes the in-kernel PM logic to create subflows matching
the currently selected source (or destination) address. IPv4 sockets
can pick only IPv4 addresses (and v4 mapped in v6), while IPv6 sockets
not restricted to V6ONLY can pick either IPv4 and IPv6 addresses as
long as the source and destination matches.

A helper, previously introduced is used to ease family matching checks,
taking care of IPv4 vs IPv4-mapped-IPv6 vs IPv6 only addresses.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/269
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

mptcp: use net instead of sock_net

Use the local variable 'net' instead of sock_net() in the functions where
the variable 'struct net *net' has been defined.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix locking for in-kernel listener creation

For consistency, in mptcp_pm_nl_create_listen_socket(), we need to
call the __mptcp_nmpc_socket() under the msk socket lock.

Note that as a side effect, mptcp_subflow_create_socket() needs a
'nested' lockdep annotation, as it will acquire the subflow (kernel)
socket lock under the in-kernel listener msk socket lock.

The current lack of locking is almost harmless, because the relevant
socket is not exposed to the user space, but in future we will add
more complexity to the mentioned helper, let's play safe.

Fixes: 1729cf186d8a ("mptcp: create the listening socket for new port")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: return 0 instead of 'err' var

When 'err' is 0, it looks clearer to return '0' instead of the variable
called 'err'.

The behaviour is then not modified, just a clearer code.

By doing this, we can also avoid false positive smatch warnings like
this one:

net/mptcp/pm_netlink.c:1169 mptcp_pm_parse_pm_addr_attr() warn: missing error code? 'err'

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: use nlmsg_free instead of kfree_skb

Use nlmsg_free() instead of kfree_skb() in pm_netlink.c.

The SKB's have been created by nlmsg_new(). The proper cleaning way
should then be done with nlmsg_free().

For the moment, nlmsg_free() is simply calling kfree_skb() so we don't
change the behaviour here.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add pm listener events

This patch adds two new MPTCP netlink event types for PM listening
socket create and close, named MPTCP_EVENT_LISTENER_CREATED and
MPTCP_EVENT_LISTENER_CLOSED.

Add a new function mptcp_event_pm_listener() to push the new events
with family, port and addr to userspace.

Invoke mptcp_event_pm_listener() with MPTCP_EVENT_LISTENER_CREATED in
mptcp_listen() and mptcp_pm_nl_create_listen_socket(), invoke it with
MPTCP_EVENT_LISTENER_CLOSED in __mptcp_close_ssk().

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: more detailed error reporting on endpoint creation

Endpoint creation can fail for a number of reasons; in case of failure
append the error number to the extended ack message, using a newly
introduced generic helper.

Additionally let mptcp_pm_nl_append_new_local_addr() report different
error reasons.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: deduplicate error paths on endpoint creation

When endpoint creation fails, we need to free the newly allocated
entry and eventually destroy the paired mptcp listener socket.

Consolidate such action in a single point let all the errors path
reach it.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: account memory allocation in mptcp_nl_cmd_add_addr() to user

Now that non-root users can configure MPTCP endpoints, account
the memory allocation to the user.

Signed-off-by: Thomas Haller <thaller@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

mptcp: allow privileged operations from user namespaces

GENL_ADMIN_PERM checks that the user has CAP_NET_ADMIN in the initial
namespace by calling netlink_capable(). Instead, use GENL_UNS_ADMIN_PERM
which uses netlink_ns_capable(). This checks that the caller has
CAP_NET_ADMIN in the current user namespace.

See also

commit 4a92602aa1cd ("openvswitch: allow management from inside user namespaces")

which introduced this mechanism. See also

commit 5617c6cd6f84 ("nl80211: Allow privileged operations from user namespaces")

which introduced this for nl80211.

Signed-off-by: Thomas Haller <thaller@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

mptcp: add mptcp_for_each_subflow_safe helper

Similar to mptcp_for_each_subflow(): this is clearer now that the _safe
version is used in multiple places.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

genetlink: start to validate reserved header bytes

We had historically not checked that genlmsghdr.reserved
is 0 on input which prevents us from using those precious
bytes in the future.

One use case would be to extend the cmd field, which is
currently just 8 bits wide and 256 is not a lot of commands
for some core families.

To make sure that new families do the right thing by default
put the onus of opting out of validation on existing families.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com> (NetLabel)
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: more accurate MPC endpoint tracking

Currently the id accounting for the ID 0 subflow is not correct:
at creation time we mark (correctly) as unavailable the endpoint
id corresponding the MPC subflow source address, while at subflow
removal time set as available the id 0.

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

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: allow the in kernel PM to set MPC subflow priority

Any local endpoints configured on the address matching the
MPC subflow are currently ignored.

Specifically, setting a backup flag on them has no effect
on the first subflow, as the MPC handshake can't carry such
info.

This change refactors the MPC endpoint id accounting to
additionally fetch the priority info from the relevant endpoint
and eventually trigger the MP_PRIO handshake as needed.

As a result, the MPC subflow now switches to backup priority
after that the MPTCP socket is fully established, according
to the local endpoint configuration.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: address lookup improvements

When looking-up a socket address in the endpoint list, we
must prefer port-based matches over address only match.

Ensure that port-based endpoints are listed first, using
head insertion for them. Additionally be sure that only
port-based endpoints carry a non zero port number.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: introduce and use mptcp_pm_send_ack()

The in-kernel PM has a bit of duplicate code related to ack
generation. Create a new helper factoring out the PM-specific
needs and use it in a couple of places.

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

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: mptcp: fix some spelling mistake in mptcp

codespell finds some spelling mistake in mptcp:

net/mptcp/subflow.c:1624: interaces ==> interfaces
net/mptcp/pm_netlink.c:1130: regarless ==> regardless

Just fix them.

Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Link: https://lore.kernel.org/r/20220627121626.1595732-1-imagedong@tencent.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: fix local endpoint accounting

In mptcp_pm_nl_rm_addr_or_subflow() we always mark as available
the id corresponding to the just removed address.

The used bitmap actually tracks only the local IDs: we must
restrict the operation when a (local) subflow is removed.

Fixes: a88c9e496937 ("mptcp: do not block subflows creation on errors")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: netlink: issue MP_PRIO signals from userspace PMs

This change updates MPTCP_PM_CMD_SET_FLAGS to allow userspace PMs
to issue MP_PRIO signals over a specific subflow selected by
the connection token, local and remote address+port.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/286
Fixes: 702c2f646d42 ("mptcp: netlink: allow userspace-driven subflow establishment")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: Acquire the subflow socket lock before modifying MP_PRIO flags

When setting up a subflow's flags for sending MP_PRIO MPTCP options, the
subflow socket lock was not held while reading and modifying several
struct members that are also read and modified in mptcp_write_options().

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

Fixes: 067065422fcd ("mptcp: add the outgoing MP_PRIO support")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: Avoid acquiring PM lock for subflow priority changes

The in-kernel path manager code for changing subflow flags acquired both
the msk socket lock and the PM lock when possibly changing the "backup"
and "fullmesh" flags. mptcp_pm_nl_mp_prio_send_ack() does not access
anything protected by the PM lock, and it must release and reacquire
the PM lock.

By pushing the PM lock to where it is needed in mptcp_pm_nl_fullmesh(),
the lock is only acquired when the fullmesh flag is changed and the
backup flag code no longer has to release and reacquire the PM lock. The
change in locking context requires the MIB update to be modified - move
that to a better location instead.

This change also makes it possible to call
mptcp_pm_nl_mp_prio_send_ack() for the userspace PM commands without
manipulating the in-kernel PM lock.

Fixes: 0f9f696a502e ("mptcp: add set_flags command in PM netlink")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: netlink: allow userspace-driven subflow establishment

This allows userspace to tell kernel to add a new subflow to an existing
mptcp connection.

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

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

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

Acked-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: netlink: Add MPTCP_PM_CMD_REMOVE

This change adds a MPTCP netlink command for issuing a
REMOVE_ADDR signal for an address over the chosen MPTCP
connection from a userspace path manager.

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

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: netlink: Add MPTCP_PM_CMD_ANNOUNCE

This change adds a MPTCP netlink interface for issuing
ADD_ADDR advertisements over the chosen MPTCP connection from a
userspace path manager.

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

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: netlink: split mptcp_pm_parse_addr into two functions

Next patch will need to parse MPTCP_PM_ATTR_ADDR attributes and
fill an mptcp_addr_info structure from a different genl command
callback.

To avoid copy-paste, split the existing function to a helper
that does the common part and then call the helper from the
(renamed)mptcp_pm_parse_entry function.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: read attributes of addr entries managed by userspace PMs

This change introduces a parallel path in the kernel for retrieving
the local id, flags, if_index for an addr entry in the context of
an MPTCP connection that's being managed by a userspace PM. The
userspace and in-kernel PM modes deviate in their procedures for
obtaining this information.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: handle local addrs announced by userspace PMs

This change adds an internal function to store/retrieve local
addrs announced by userspace PM implementations to/from its kernel
context. The function addresses the requirements of three scenarios:
1) ADD_ADDR announcements (which require that a local id be
provided), 2) retrieving the local id associated with an address,
and also where one may need to be assigned, and 3) reissuance of
ADD_ADDRs when there's a successful match of addr/id.

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

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: allow ADD_ADDR reissuance by userspace PMs

This change allows userspace PM implementations to reissue ADD_ADDR
announcements (if necessary) based on their chosen policy.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: expose server_side attribute in MPTCP netlink events

This change records the 'server_side' attribute of MPTCP_EVENT_CREATED
and MPTCP_EVENT_ESTABLISHED events to inform their recipient about the
Client/Server role of the running MPTCP application.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/246
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: reflect remote port (not 0) in ANNOUNCED events

Per RFC 8684, if no port is specified in an ADD_ADDR message, MPTCP
SHOULD attempt to connect to the specified address on the same port
as the port that is already in use by the subflow on which the
ADD_ADDR signal was sent.

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

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: bypass in-kernel PM restrictions for non-kernel PMs

Current limits on the # of addresses/subflows must apply only to
in-kernel PM managed sockets. Thus this change removes such
restrictions on connections overseen by non-kernel (e.g. userspace)
PMs. This change also ensures that the kernel does not record stats
inside struct mptcp_pm_data updated along kernel code paths when exercised
via non-kernel PMs.

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

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: Make kernel path manager check for userspace-managed sockets

Userspace-managed sockets should not have their subflows or
advertisements changed by the kernel path manager.

v3: Use helper function for PM mode (Paolo Abeni)

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: Remove redundant assignments in path manager init

A few members of the mptcp_pm_data struct were assigned to hard-coded
values in mptcp_pm_data_reset(), and then immediately changed in
mptcp_pm_nl_data_init().

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

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

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add pm_nl_pernet helpers

This patch adds two pm_nl_pernet related helpers, named pm_nl_get_pernet()
and pm_nl_get_pernet_from_msk() to get pm_nl_pernet from 'net' or 'msk'.
Use these helpers instead of using net_generic() directly.

Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: reset the packet scheduler on PRIO change

Similar to the previous patch, for priority changes
requested by the local PM.

Reported-and-suggested-by: Davide Caratti <dcaratti@redhat.com>
Fixes: 067065422fcd ("mptcp: add the outgoing MP_PRIO support")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: send ADD_ADDR echo before create subflows

In some corner cases, the peer handing an incoming ADD_ADDR option, can
receive a retransmitted ADD_ADDR for the same address before the subflow
creation completes.

We can avoid the above issue by generating and sending the ADD_ADDR echo
before starting the MPJ subflow connection.

This slightly changes the behaviour of the packetdrill tests as the
ADD_ADDR echo packet is sent earlier.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Link: https://lore.kernel.org/r/20220317221444.426335-1-mathew.j.martineau@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add fullmesh flag check for adding address

The fullmesh flag mustn't be used with the signal flag when adding an
address. This patch added the necessary flags check for this case.

Fixes: 73c762c1f07d ("mptcp: set fullmesh flag in pm_netlink")
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: strict local address ID selection

The address ID selection for MPJ subflows created in response
to incoming ADD_ADDR option is currently unreliable: it happens
at MPJ socket creation time, when the local address could be
unknown.

Additionally, if the no local endpoint is available for the local
address, a new dummy endpoint is created, confusing the user-land.

This change refactor the code to move the address ID selection inside
the rebuild_header() helper, when the local address eventually
selected by the route lookup is finally known. If the address used
is not mapped by any endpoint - and thus can't be advertised/removed
pick the id 0 instead of allocate a new endpoint.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: introduce implicit endpoints

In some edge scenarios, an MPTCP subflows can use a local address
mapped by a "implicit" endpoint created by the in-kernel path manager.

Such endpoints presence can be confusing, as it's creation is hard
to track and will prevent the later endpoint creation from the user-space
using the same address.

Define a new endpoint flag to mark implicit endpoints and allow the
user-space to replace implicit them with user-provided data at endpoint
creation time.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: more careful RM_ADDR generation

The in-kernel MPTCP path manager, when processing the MPTCP_PM_CMD_FLUSH_ADDR
command, generates RM_ADDR events for each known local address. While that
is allowed by the RFC, it makes unpredictable the exact number of RM_ADDR
generated when both ends flush the PM addresses.

This change restricts the RM_ADDR generation to previously explicitly
announced addresses, and adjust the expected results in a bunch of related
self-tests.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: constify a bunch of of helpers

A few pm-related helpers don't touch arguments which lacking
the const modifier, let's constify them.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: allow to use port and non-signal in set_flags

It's illegal to use both port and non-signal flags for adding address.
But it's legal to use both of them for setting flags, which always uses
non-signal flags, backup or fullmesh.

This patch moves this non-signal flag with port check from
mptcp_pm_parse_addr() to mptcp_nl_cmd_add_addr(). Do the check only when
adding addresses, not setting flags or deleting addresses.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: set fullmesh flag in pm_netlink

This patch added the fullmesh flag setting support in pm_netlink.

If the fullmesh flag of the address is changed, remove all the related
subflows, update the fullmesh flag and create subflows again.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix race in incoming ADD_ADDR option processing

If an MPTCP endpoint received multiple consecutive incoming
ADD_ADDR options, mptcp_pm_add_addr_received() can overwrite
the current remote address value after the PM lock is released
in mptcp_pm_nl_add_addr_received() and before such address
is echoed.

Fix the issue caching the remote address value a little earlier
and always using the cached value after releasing the PM lock.

Fixes: f7efc7771eac ("mptcp: drop argument port from mptcp_pm_announce_addr")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix race in overlapping signal events

After commit a88c9e496937 ("mptcp: do not block subflows
creation on errors"), if a signal address races with a failing
subflow creation, the subflow creation failure control path
can trigger the selection of the next address to be announced
while the current announced is still pending.

The above will cause the unintended suppression of the ADD_ADDR
announce.

Fix the issue skipping the to-be-suppressed announce before it
will mark an endpoint as already used. The relevant announce
will be triggered again when the current one will complete.

Fixes: a88c9e496937 ("mptcp: do not block subflows creation on errors")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: netlink: process IPv6 addrs in creating listening sockets

This change updates mptcp_pm_nl_create_listen_socket() to create
listening sockets bound to IPv6 addresses (where IPv6 is supported).

Fixes: 1729cf186d8a ("mptcp: create the listening socket for new port")
Acked-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: fix removing ids bitmap setting

In mptcp_pm_nl_rm_addr_or_subflow(), the bit of rm_list->ids[i] in the
id_avail_bitmap should be set, not rm_list->ids[1]. This patch fixed it.

Fixes: 86e39e04482b ("mptcp: keep track of local endpoint still available for each msk")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: fix msk traversal in mptcp_nl_cmd_set_flags()

The MPTCP endpoint list is under RCU protection, guarded by the
pernet spinlock. mptcp_nl_cmd_set_flags() traverses the list
without acquiring the spin-lock nor under the RCU critical section.

This change addresses the issue performing the lookup and the endpoint
update under the pernet spinlock.

Fixes: 0f9f696a502e ("mptcp: add set_flags command in PM netlink")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: cleanup MPJ subflow list handling

We can simplify the join list handling leveraging the
mptcp_release_cb(): if we can acquire the msk socket
lock at mptcp_finish_join time, move the new subflow
directly into the conn_list, otherwise place it on join_list and
let the release_cb process such list.

Since pending MPJ connection are now always processed
in a timely way, we can avoid flushing the join list
every time we have to process all the current subflows.

Additionally we can now use the mptcp data lock to protect
the join_list, removing the additional spin lock.

Finally, the MPJ handshake is now always finalized under the
msk socket lock, we can drop the additional synchronization
between mptcp_finish_join() and mptcp_close().

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: do not block subflows creation on errors

If the MPTCP configuration allows for multiple subflows
creation, and the first additional subflows never reach
the fully established status - e.g. due to packets drop or
reset - the in kernel path manager do not move to the
next subflow.

This patch introduces a new PM helper to cope with MPJ
subflow creation failure and delay and hook it where appropriate.

Such helper triggers additional subflow creation, as needed
and updates the PM subflow counter, if the current one is
closing.

Additionally start all the needed additional subflows
as soon as the MPTCP socket is fully established, so we don't
have to cope with slow MPJ handshake blocking the next subflow
creation.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: keep track of local endpoint still available for each msk

Include into the path manager status a bitmap tracking the list
of local endpoints still available - not yet used - for the
relevant mptcp socket.

Keep such map updated at endpoint creation/deletion time, so
that we can easily skip already used endpoint at local address
selection time.

The endpoint used by the initial subflow is lazyly accounted at
subflow creation time: the usage bitmap is be up2date before
endpoint selection and we avoid such unneeded task in some relevant
scenarios - e.g. busy servers accepting incoming subflows but
not creating any additional ones nor annuncing additional addresses.

Overall this allows for fair local endpoints usage in case of
subflow failure.

As a side effect, this patch also enforces that each endpoint
is used at most once for each mptcp connection.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix per socket endpoint accounting

Since full-mesh endpoint support, the reception of a single ADD_ADDR
option can cause multiple subflows creation. When such option is
accepted we increment 'add_addr_accepted' by one. When we received
a paired RM_ADDR option, we deleted all the relevant subflows,
decrementing 'add_addr_accepted' by one for each of them.

We have a similar issue for 'local_addr_used'

Fix them moving the pm endpoint accounting outside the subflow
traversal.

Fixes: 1a0d6136c5f0 ("mptcp: local addresses fullmesh")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: clean up harmless false expressions

entry->addr.id is u8 with a range from 0 to 255 and MAX_ADDR_ID is 255.
We should drop both false expressions of (entry->addr.id > MAX_ADDR_ID).

We should also remove the obsolete parentheses in the first if branch.

Use U8_MAX for MAX_ADDR_ID and add a comment to show the link to
mptcp_addr_info.id as suggested by Mr. Matthieu Baerts.

Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: allow changing the "backup" bit by endpoint id

a non-zero 'id' is sufficient to identify MPTCP endpoints: allow changing
the value of 'backup' bit by simply specifying the endpoint id.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/158
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: never allow the PM to close a listener subflow

Currently, when deleting an endpoint the netlink PM treverses
all the local MPTCP sockets, regardless of their status.

If an MPTCP listener socket is bound to the IP matching the
delete endpoint, the listener TCP socket will be closed.
That is unexpected, the PM should only affect data subflows.

Additionally, syzbot was able to trigger a NULL ptr dereference
due to the above:

general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 1 PID: 6550 Comm: syz-executor122 Not tainted 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__lock_acquire+0xd7d/0x54a0 kernel/locking/lockdep.c:4897
Code: 0f 0e 41 be 01 00 00 00 0f 86 c8 00 00 00 89 05 69 cc 0f 0e e9 bd 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 f3 2f 00 00 48 81 3b 20 75 17 8f 0f 84 52 f3 ff
RSP: 0018:ffffc90001f2f818 EFLAGS: 00010016
RAX: dffffc0000000000 RBX: 0000000000000018 RCX: 0000000000000000
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 000000000000000a R12: 0000000000000000
R13: ffff88801b98d700 R14: 0000000000000000 R15: 0000000000000001
FS: 00007f177cd3d700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f177cd1b268 CR3: 000000001dd55000 CR4: 0000000000350ee0
Call Trace:
<TASK>
lock_acquire kernel/locking/lockdep.c:5637 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
finish_wait+0xc0/0x270 kernel/sched/wait.c:400
inet_csk_wait_for_connect net/ipv4/inet_connection_sock.c:464 [inline]
inet_csk_accept+0x7de/0x9d0 net/ipv4/inet_connection_sock.c:497
mptcp_accept+0xe5/0x500 net/mptcp/protocol.c:2865
inet_accept+0xe4/0x7b0 net/ipv4/af_inet.c:739
mptcp_stream_accept+0x2e7/0x10e0 net/mptcp/protocol.c:3345
do_accept+0x382/0x510 net/socket.c:1773
__sys_accept4_file+0x7e/0xe0 net/socket.c:1816
__sys_accept4+0xb0/0x100 net/socket.c:1846
__do_sys_accept net/socket.c:1864 [inline]
__se_sys_accept net/socket.c:1861 [inline]
__x64_sys_accept+0x71/0xb0 net/socket.c:1861
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f177cd8b8e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f177cd3d308 EFLAGS: 00000246 ORIG_RAX: 000000000000002b
RAX: ffffffffffffffda RBX: 00007f177ce13408 RCX: 00007f177cd8b8e9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f177ce13400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f177ce1340c
R13: 00007f177cde1004 R14: 6d705f706374706d R15: 0000000000022000
</TASK>

Fix the issue explicitly skipping MPTCP socket in TCP_LISTEN
status.

Reported-and-tested-by: syzbot+e4d843bb96a9431e6331@syzkaller.appspotmail.com
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Fixes: 740d798e8767 ("mptcp: remove id 0 address")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/ebc7594cdd420d241fb2172ddb8542ba64717657.1639238695.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: Make mptcp_pm_nl_mp_prio_send_ack() static

This function is only used within pm_netlink.c now.

Fixes: 067065422fcd ("mptcp: add the outgoing MP_PRIO support")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: increase default max additional subflows to 2

The current default does not allowing additional subflows, mostly
as a safety restriction to avoid uncontrolled resource consumption
on busy servers.

Still the system admin and/or the application have to opt-in to
MPTCP explicitly. After that, they need to change (increase) the
default maximum number of additional subflows.

Let set that to reasonable default, and make end-users life easier.

Additionally we need to update some self-tests accordingly.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: allow changing the 'backup' bit when no sockets are open

current Linux refuses to change the 'backup' bit of MPTCP endpoints, i.e.
using MPTCP_PM_CMD_SET_FLAGS, unless it finds (at least) one subflow that
matches the endpoint address. There is no reason for that, so we can just
ignore the return value of mptcp_nl_addr_backup(). In this way, endpoints
can reconfigure their 'backup' flag even if no MPTCP sockets are open (or
more generally, in case the MP_PRIO message is not sent out).

Fixes: 0f9f696a502e ("mptcp: add set_flags command in PM netlink")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: Only send extra TCP acks in eligible socket states

Recent changes exposed a bug where specifically-timed requests to the
path manager netlink API could trigger a divide-by-zero in
__tcp_select_window(), as syzkaller does:

divide error: 0000 [#1] SMP KASAN NOPTI
CPU: 0 PID: 9667 Comm: syz-executor.0 Not tainted 5.14.0-rc6+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:__tcp_select_window+0x509/0xa60 net/ipv4/tcp_output.c:3016
Code: 44 89 ff e8 c9 29 e9 fd 45 39 e7 0f 8d 20 ff ff ff e8 db 28 e9 fd 44 89 e3 e9 13 ff ff ff e8 ce 28 e9 fd 44 89 e0 44 89 e3 99 <f7> 7c 24 04 29 d3 e9 fc fe ff ff e8 b7 28 e9 fd 44 89 f1 48 89 ea
RSP: 0018:ffff888031ccf020 EFLAGS: 00010216
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000040000
RDX: 0000000000000000 RSI: ffff88811532c080 RDI: 0000000000000002
RBP: 0000000000000000 R08: ffffffff835807c2 R09: 0000000000000000
R10: 0000000000000004 R11: ffffed1020b92441 R12: 0000000000000000
R13: 1ffff11006399e08 R14: 0000000000000000 R15: 0000000000000000
FS: 00007fa4c8344700(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f424000 CR3: 000000003e4e2003 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
tcp_select_window net/ipv4/tcp_output.c:264 [inline]
__tcp_transmit_skb+0xc00/0x37a0 net/ipv4/tcp_output.c:1351
__tcp_send_ack.part.0+0x3ec/0x760 net/ipv4/tcp_output.c:3972
__tcp_send_ack net/ipv4/tcp_output.c:3978 [inline]
tcp_send_ack+0x7d/0xa0 net/ipv4/tcp_output.c:3978
mptcp_pm_nl_addr_send_ack+0x1ab/0x380 net/mptcp/pm_netlink.c:654
mptcp_pm_remove_addr+0x161/0x200 net/mptcp/pm.c:58
mptcp_nl_remove_id_zero_address+0x197/0x460 net/mptcp/pm_netlink.c:1328
mptcp_nl_cmd_del_addr+0x98b/0xd40 net/mptcp/pm_netlink.c:1359
genl_family_rcv_msg_doit.isra.0+0x225/0x340 net/netlink/genetlink.c:731
genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
genl_rcv_msg+0x341/0x5b0 net/netlink/genetlink.c:792
netlink_rcv_skb+0x148/0x430 net/netlink/af_netlink.c:2504
genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
netlink_unicast+0x537/0x750 net/netlink/af_netlink.c:1340
netlink_sendmsg+0x846/0xd80 net/netlink/af_netlink.c:1929
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg+0x14e/0x190 net/socket.c:724
____sys_sendmsg+0x709/0x870 net/socket.c:2403
___sys_sendmsg+0xff/0x170 net/socket.c:2457
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2486
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

mptcp_pm_nl_addr_send_ack() was attempting to send a TCP ACK on the
first subflow in the MPTCP socket's connection list without validating
that the subflow was in a suitable connection state. To address this,
always validate subflow state when sending extra ACKs on subflows
for address advertisement or subflow priority change.

Fixes: 84dfe3677a6f ("mptcp: send out dedicated ADD_ADDR packet")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/229
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: remove MPTCP_ADD_ADDR_IPV6 and MPTCP_ADD_ADDR_PORT

MPTCP_ADD_ADDR_IPV6 and MPTCP_ADD_ADDR_PORT are not necessary, we can get
these info from pm.local or pm.remote.

Drop mptcp_pm_should_add_signal_ipv6 and mptcp_pm_should_add_signal_port
too.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: make MPTCP_ADD_ADDR_SIGNAL and MPTCP_ADD_ADDR_ECHO separate

Use MPTCP_ADD_ADDR_SIGNAL only for the action of sending ADD_ADDR, and
use MPTCP_ADD_ADDR_ECHO only for the action of sending ADD_ADDR echo.

Use msk->pm.local to save the announced ADD_ADDR address only, and reuse
msk->pm.remote to save the announced ADD_ADDR_ECHO address.

To prepare for the next patch.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: local addresses fullmesh

In mptcp_pm_nl_add_addr_received(), fill a temporary allocate array of
all local address corresponding to the fullmesh endpoint. If such array
is empty, keep the current behavior.

Elsewhere loop on such array and create a subflow for each local address
towards the given remote address

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: remote addresses fullmesh

This patch added and managed a new per endpoint flag, named
MPTCP_PM_ADDR_FLAG_FULLMESH.

In mptcp_pm_create_subflow_or_signal_addr(), if such flag is set, instead
of:
remote_address((struct sock_common *)sk, &remote);
fill a temporary allocated array of all known remote address. After
releaseing the pm lock loop on such array and create a subflow for each
remote address from the given local.

Note that the we could still use an array even for non 'fullmesh'
endpoint: with a single entry corresponding to the primary MPC subflow
remote address.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: drop flags and ifindex arguments

This patch added a new helper mptcp_pm_get_flags_and_ifindex_by_id(),
and used it in __mptcp_subflow_connect() to get the flags and ifindex
values.

Then the two arguments flags and ifindex of __mptcp_subflow_connect()
can be dropped.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add mibs for stale subflows processing

This allows monitoring exceptional events like
active backup scenarios.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: faster active backup recovery

The msk can use backup subflows to transmit in-sequence data
only if there are no other active subflow. On active backup
scenario, the MPTCP connection can do forward progress only
due to MPTCP retransmissions - rtx can pick backup subflows.

This patch introduces a new flag flow MPTCP subflows: if the
underlying TCP connection made no progresses for long time,
and there are other less problematic subflows available, the
given subflow become stale.

Stale subflows are not considered active: if all non backup
subflows become stale, the MPTCP scheduler can pick backup
subflows for plain transmissions.

Stale subflows can return in active state, as soon as any reply
from the peer is observed.

Active backup scenarios can now leverage the available b/w
with no restrinction.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix memory leak on address flush

The endpoint cleanup path is prone to a memory leak, as reported
by syzkaller:

BUG: memory leak
unreferenced object 0xffff88810680ea00 (size 64):
comm "syz-executor.6", pid 6191, jiffies 4295756280 (age 24.138s)
hex dump (first 32 bytes):
58 75 7d 3c 80 88 ff ff 22 01 00 00 00 00 ad de Xu}<....".......
01 00 02 00 00 00 00 00 ac 1e 00 07 00 00 00 00 ................
backtrace:
[<0000000072a9f72a>] kmalloc include/linux/slab.h:591 [inline]
[<0000000072a9f72a>] mptcp_nl_cmd_add_addr+0x287/0x9f0 net/mptcp/pm_netlink.c:1170
[<00000000f6e931bf>] genl_family_rcv_msg_doit.isra.0+0x225/0x340 net/netlink/genetlink.c:731
[<00000000f1504a2c>] genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
[<00000000f1504a2c>] genl_rcv_msg+0x341/0x5b0 net/netlink/genetlink.c:792
[<0000000097e76f6a>] netlink_rcv_skb+0x148/0x430 net/netlink/af_netlink.c:2504
[<00000000ceefa2b8>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
[<000000008ff91aec>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
[<000000008ff91aec>] netlink_unicast+0x537/0x750 net/netlink/af_netlink.c:1340
[<0000000041682c35>] netlink_sendmsg+0x846/0xd80 net/netlink/af_netlink.c:1929
[<00000000df3aa8e7>] sock_sendmsg_nosec net/socket.c:704 [inline]
[<00000000df3aa8e7>] sock_sendmsg+0x14e/0x190 net/socket.c:724
[<000000002154c54c>] ____sys_sendmsg+0x709/0x870 net/socket.c:2403
[<000000001aab01d7>] ___sys_sendmsg+0xff/0x170 net/socket.c:2457
[<00000000fa3b1446>] __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486
[<00000000db2ee9c7>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<00000000db2ee9c7>] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
[<000000005873517d>] entry_SYSCALL_64_after_hwframe+0x44/0xae

We should not require an allocation to cleanup stuff.

Rework the code a bit so that the additional RCU work is no more needed.

Fixes: 1729cf186d8a ("mptcp: create the listening socket for new port")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: drop unused rcu member in mptcp_pm_addr_entry

kfree_rcu() had been removed from pm_netlink.c, so this rcu field in
struct mptcp_pm_addr_entry became useless. Let's drop it.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Link: https://lore.kernel.org/r/20210802231914.54709-1-mathew.j.martineau@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add deny_join_id0 in mptcp_options_received

This patch added a new flag named deny_join_id0 in struct
mptcp_options_received. Set it when MP_CAPABLE with the flag
MPTCP_CAP_DENYJOIN_ID0 is received.

Also add a new flag remote_deny_join_id0 in struct mptcp_pm_data. When the
flag deny_join_id0 is set, set this remote_deny_join_id0 flag.

In mptcp_pm_create_subflow_or_signal_addr, if the remote_deny_join_id0 flag
is set, and the remote address id is zero, stop this connection.

Suggested-by: Florian Westphal <fw@strlen.de>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: use fast lock for subflows when possible

There are a bunch of callsite where the ssk socket
lock is acquired using the full-blown version eligible for
the fast variant. Let's move to the latter.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: make sure flag signal is set when add addr with port

When add address with port, it is mean to create a listening socket,
and send an ADD_ADDR to remote, so it must have flag signal set,
add this check in mptcp_pm_parse_addr().

Fixes: a77e9179c7651 ("mptcp: deal with MPTCP_PM_ADDR_ATTR_PORT in PM netlink")
Acked-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: remove redundant initialization in pm_nl_init_net()

Memory of struct pm_nl_pernet{} is allocated by kzalloc()
in setup_net()->ops_init(), so it's no need to reset counters
and zero bitmap in pm_nl_init_net().

Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: validate 'id' when stopping the ADD_ADDR retransmit timer

when Linux receives an echo-ed ADD_ADDR, it checks the IP address against
the list of "announced" addresses. In case of a positive match, the timer
that handles retransmissions is stopped regardless of the 'Address Id' in
the received packet: this behaviour does not comply with RFC8684 3.4.1.

Fix it by validating the 'Address Id' in received echo-ed ADD_ADDRs.
Tested using packetdrill, with the following captured output:

unpatched kernel:

Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0xfd2e62517888fe29,mptcp dss ack 3007449509], length 0
In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 1 1.2.3.4,mptcp dss ack 3013740213], length 0
Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0xfd2e62517888fe29,mptcp dss ack 3007449509], length 0
In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 90 198.51.100.2,mptcp dss ack 3013740213], length 0
^^^ retransmission is stopped here, but 'Address Id' is 90

patched kernel:

Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0x1cf372d59e05f4b8,mptcp dss ack 3007449509], length 0
In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 1 1.2.3.4,mptcp dss ack 1672384568], length 0
Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0x1cf372d59e05f4b8,mptcp dss ack 3007449509], length 0
In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 90 198.51.100.2,mptcp dss ack 1672384568], length 0
Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0x1cf372d59e05f4b8,mptcp dss ack 3007449509], length 0
In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 1 198.51.100.2,mptcp dss ack 1672384568], length 0
^^^ retransmission is stopped here, only when both 'Address Id' and 'IP Address' match

Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: move flags and ifindex out of mptcp_addr_info

This patch moved the flags and ifindex fields from struct mptcp_addr_info
to struct mptcp_pm_addr_entry. Add the flags and ifindex values as two new
parameters to __mptcp_subflow_connect.

In mptcp_pm_create_subflow_or_signal_addr, pass the local address entry's
flags and ifindex fields to __mptcp_subflow_connect.

In mptcp_pm_nl_add_addr_received, just pass two zeros to it.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add mptcp reset option support

The MPTCP reset option allows to carry a mptcp-specific error code that
provides more information on the nature of a connection reset.

Reset option data received gets stored in the subflow context so it can
be sent to userspace via the 'subflow closed' netlink event.

When a subflow is closed, the desired error code that should be sent to
the peer is also placed in the subflow context structure.

If a reset is sent before subflow establishment could complete, e.g. on
HMAC failure during an MP_JOIN operation, the mptcp skb extension is
used to store the reset information.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: remove id 0 address

This patch added a new function mptcp_nl_remove_id_zero_address to
remove the id 0 address.

In this function, traverse all the existing msk sockets to find the
msk matched the input IP address. Then fill the removing list with
id 0, and pass it to mptcp_pm_remove_addr and mptcp_pm_remove_subflow.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: unify RM_ADDR and RM_SUBFLOW receiving

There are some duplicate code in mptcp_pm_nl_rm_addr_received and
mptcp_pm_nl_rm_subflow_received. This patch unifies them into a new
function named mptcp_pm_nl_rm_addr_or_subflow. In it, use the input
parameter rm_type to identify it's now removing an address or a subflow.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: remove all subflows involving id 0 address

There's only one subflow involving the non-zero id address, but there
may be multi subflows involving the id 0 address.

Here's an example:

local_id=0, remote_id=0
local_id=1, remote_id=0
local_id=0, remote_id=1

If the removing address id is 0, all the subflows involving the id 0
address need to be removed.

In mptcp_pm_nl_rm_addr_received/mptcp_pm_nl_rm_subflow_received, the
"break" prevents the iteration to the next subflow, so this patch
dropped them.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: rename mptcp_pm_nl_add_addr_send_ack

Since mptcp_pm_nl_add_addr_send_ack is now used for both ADD_ADDR and
RM_ADDR cases, rename it to mptcp_pm_nl_addr_send_ack.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: send ack for rm_addr

This patch changes the sending ACK conditions for the ADD_ADDR, send an
ACK packet for RM_ADDR too.

In mptcp_pm_remove_addr, invoke mptcp_pm_nl_add_addr_send_ack to send
the ACK packet.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: drop useless addr_signal clear

msk->pm.addr_signal is cleared in mptcp_pm_add_addr_signal, no need to
clear it in mptcp_pm_nl_add_addr_send_ack again. Drop it.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: export lookup_anno_list_by_saddr

This patch exported the static function lookup_anno_list_by_saddr, and
renamed it to mptcp_lookup_anno_list_by_saddr.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: move to next addr when timeout

This patch called mptcp_pm_subflow_established to move to the next address
when an ADD_ADDR has been retransmitted the maximum number of times.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: skip connecting the connected address

This patch added a new helper named lookup_subflow_by_daddr to find
whether the destination address is in the msk's conn_list.

In mptcp_pm_nl_add_addr_received, use lookup_subflow_by_daddr to check
whether the announced address is already connected. If it is, skip
connecting this address and send out the echo.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: drop argument port from mptcp_pm_announce_addr

Drop the redundant argument 'port' from mptcp_pm_announce_addr, use the
port field of another argument 'addr' instead.

Fixes: 0f5c9e3f079f ("mptcp: add port parameter for mptcp_pm_announce_addr")
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: remove a list of addrs when flushing

This patch invoked mptcp_nl_remove_addrs_list to remove a list of addresses
when the netlink flushes addresses, instead of using
mptcp_nl_remove_subflow_and_signal_addr to remove them one by one.

And dropped the unused parameter net in __flush_addrs too.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: remove multi addresses and subflows in PM

This patch implemented the function to remove a list of addresses and
subflows, named mptcp_nl_remove_addrs_list, which had a input parameter
rm_list as the removing addresses list.

In mptcp_nl_remove_addrs_list, traverse all the existing msk sockets to
invoke mptcp_pm_remove_addrs_and_subflows to remove a list of addresses
for each msk socket.

In mptcp_pm_remove_addrs_and_subflows, traverse all the addresses in the
removing addresses list, to find whether this address is in the conn_list
or anno_list. If it is, put the address ID into the removing address list
or the removing subflow list, and pass the two lists to
mptcp_pm_remove_addr and mptcp_pm_remove_subflow.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: remove multi subflows in PM

This patch dealt with removing multi subflows in PM:

In mptcp_pm_remove_subflow, changed the input parameter local_id as an
list of removing address ids, and passed the list to
mptcp_pm_nl_rm_subflow_received.

In mptcp_pm_nl_rm_subflow_received, iterated each address id from the
received ids list. Then shut down and closed each address id's subsocket.

In mptcp_nl_remove_subflow_and_signal_addr, put the single address id into
an ids list, and passed it to mptcp_pm_remove_subflow.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: remove multi addresses in PM

This patch dropped the member rm_id of struct mptcp_pm_data. Use
rm_list_rx in mptcp_pm_nl_rm_addr_received instead of using rm_id.

In mptcp_pm_nl_rm_addr_received, iterated each address id from
pm.rm_list_rx, then shut down and closed each address id's subsocket.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add rm_list_tx in mptcp_pm_data

This patch added a new member rm_list_tx for struct mptcp_pm_data as the
removing address list on the outgoing direction. Initialize its nr field
to zero in mptcp_pm_data_init.

In mptcp_pm_remove_anno_addr, put the single address id into an removing
list, and passed it to mptcp_pm_remove_addr.

In mptcp_pm_remove_addr, save the input rm_list to rm_list_tx in struct
mptcp_pm_data.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add local addr info in mptcp_info

Add mptcpi_local_addr_used and mptcpi_local_addr_max in struct mptcp_info.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add netlink event support

Allow userspace (mptcpd) to subscribe to mptcp genl multicast events.
This implementation reuses the same event API as the mptcp kernel fork
to ease integration of existing tools, e.g. mptcpd.

Supported events include:
1. start and close of an mptcp connection
2. start and close of subflows (joins)
3. announce and withdrawals of addresses
4. subflow priority (backup/non-backup) change.

Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: split __mptcp_close_ssk helper

Prepare for subflow close events:

When mptcp connection is torn down its enough to send the mptcp socket
close notification rather than a subflow close event for all of the
subflows followed by the mptcp close event.

This splits the helper: mptcp_close_ssk() will emit the close
notification, __mptcp_close_ssk will not.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: move pm netlink work into pm_netlink

Allows to make some functions static and avoids acquire of the pm
spinlock in protocol.c.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: pm: add lockdep assertions

Add a few assertions to make sure functions are called with the needed
locks held.
Two functions gain might_sleep annotations because they contain
conditional calls to functions that sleep.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: deal with MPTCP_PM_ADDR_ATTR_PORT in PM netlink

This patch adds MPTCP_PM_ADDR_ATTR_PORT filling and parsing in PM
netlink.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: enable use_port when invoke addresses_equal

When dealing with the addresses list local_addr_list or anno_list, we
should enable the function addresses_equal's parameter use_port. And
enable it in address_zero too.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add port number check for MP_JOIN

This patch adds two new helpers, subflow_use_different_sport and
subflow_use_different_dport, to check whether the subflow's source or
destination port number is different from the msk's port number. When
receiving the MP_JOIN's SYN/SYNACK/ACK, we do these port number checks
and print out the different port numbers.

And furthermore, when receiving the MP_JOIN's SYN/ACK, we also use a new
helper mptcp_pm_sport_in_anno_list to check whether this port number is
announced. If it isn't, we need to abort this connection.

This patch also populates the local address's port field in
local_address.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: create the listening socket for new port

This patch creates a listening socket when an address with a port-number
is added by PM netlink. Then binds the new port to the socket, and
listens for new connections.

When the address is removed or the addresses are flushed by PM netlink,
release the listening socket.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: send ack for every add_addr

This patch changes the sending ACK conditions for the ADD_ADDR, send an
ACK packet for any ADD_ADDR, not just when ipv6 addresses or port
numbers are included.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/139
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: create subflow or signal addr for newly added address

Currently, when a new MPTCP endpoint is added, the existing MPTCP
sockets are not affected.

This patch implements a new function mptcp_nl_add_subflow_or_signal_addr,
invoked when an address is added from PM netlink. This function traverses
the MPTCP sockets list and invokes mptcp_pm_create_subflow_or_signal_addr
to try to create a subflow or signal an address for the newly added
address, if local constraint allows that.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/19
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: drop *_max fields in mptcp_pm_data

This patch drops the per-msk values add_addr_signal_max,
add_addr_accept_max, local_addr_max and subflows_max fields in struct
mptcp_pm_data, uses the pernet *_max values instead. And adds four new
helpers to get the pernet *_max values separately.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: use WRITE_ONCE for the pernet *_max

This patch uses WRITE_ONCE() for all the pernet add_addr_signal_max,
add_addr_accept_max, local_addr_max and subflows_max fields in struct
pm_nl_pernet to avoid concurrency issues.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: pm nl: reduce variable scope

To avoid confusions like when working on the previous patch, better to
declare and assign this variable only where it is needed.

Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: pm nl: support IPv4 mapped in v6 addresses

On one side, we can allow the creation of subflows between v4 mapped in
v6 and v4 addresses. For that we look for v4mapped addresses between the
local address we want to select and the remote one.

On the other side, we also properly deal with received v4mapped
addresses, either announced ones or set via Netlink.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/122
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add the mibs for MP_PRIO

This patch added the mibs for MP_PRIO, MPTCP_MIB_MPPRIOTX for transmitting
of the MP_PRIO suboption, and MPTCP_MIB_MPPRIORX for receiving of it.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add set_flags command in PM netlink

This patch added a new command MPTCP_PM_CMD_SET_FLAGS in PM netlink:

In mptcp_nl_cmd_set_flags, parse the input address, get the backup value
according to whether the address's FLAG_BACKUP flag is set from the
user-space. Then check whether this address had been added in the local
address list. If it had been, then call mptcp_nl_addr_backup to deal with
this address.

In mptcp_nl_addr_backup, traverse all the existing msk sockets to find
the relevant sockets, and call mptcp_pm_nl_mp_prio_send_ack to send out
a MP_PRIO ACK packet.

Finally in mptcp_nl_cmd_set_flags, set or clear the address's FLAG_BACKUP
flag.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add the outgoing MP_PRIO support

This patch added the outgoing MP_PRIO logic:

In mptcp_pm_nl_mp_prio_send_ack, find the related subflow and subsocket
according to the input parameter addr. Save the input priority value to
suflow's backup, then set subflow's send_mp_prio flag to true, and save
the input priority value to suflow's request_bkup. Finally, send out a
pure ACK on the related subsocket.

In mptcp_established_options_mp_prio, check whether the subflow's
send_mp_prio is set. If it is, this is the packet for sending MP_PRIO.
So save subflow->request_bkup value to mptcp_out_options's backup, and
change the option type to OPTION_MPTCP_PRIO.

In mptcp_write_options, clear the send_mp_prio flag and send out the
MP_PRIO suboption with mptcp_out_options's backup value.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add the address ID assignment bitmap

Currently the address ID set by the netlink PM from user-space is
overridden by the kernel. This patch added the address ID assignment
bitmap to allow user-space to set the address ID.

Use a per netns bitmask id_bitmap (256 bits) to keep track of in-use IDs.
And use next_id to keep track of the highest ID currently in use. If the
user-space provides an ID at endpoint creation time, try to use it. If
already in use, endpoint creation fails. Otherwise pick the first ID
available after the highest currently in use, with wrap-around.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: pm: simplify select_local_address()

There is no need to unconditionally acquire the join list
lock, we can simply splice the join list into the subflow
list and traverse only the latter.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: remove address when netlink flushes addrs

When the PM netlink flushes the addresses, invoke the remove address
function mptcp_nl_remove_subflow_and_signal_addr to remove the addresses
and the subflows. Since this function should not be invoked under lock,
move __flush_addrs out of the pernet->lock.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: use the variable sk instead of open-coding

Since the local variable sk has been defined, use it instead of
open-coding.

Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: rename add_addr_signal and mptcp_add_addr_status

Since the RM_ADDR signal had been reused with add_addr_signal, it's not
suitable to call it add_addr_signal or mptcp_add_addr_status. So this
patch renamed add_addr_signal to addr_signal, and renamed
mptcp_add_addr_status to mptcp_addr_signal_status.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add port parameter for mptcp_pm_announce_addr

This patch added a new parameter 'port' for mptcp_pm_announce_addr. If
this parameter is true, we set the MPTCP_ADD_ADDR_PORT bit of the
add_addr_signal. That means the announced address is added with a port
number.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: send out dedicated packet for ADD_ADDR using port

The process is similar to that of the ADD_ADDR IPv6, this patch also sent
out a pure ack for the ADD_ADDR using port.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: send out dedicated ADD_ADDR packet

When ADD_ADDR suboption includes an IPv6 address, the size is 28 octets.
It will not fit when other MPTCP suboptions are included in this packet,
e.g. DSS. So here we send out an ADD_ADDR dedicated packet to carry only
ADD_ADDR suboption, no other MPTCP suboptions.

In mptcp_pm_announce_addr, we check whether this is an IPv6 ADD_ADDR.
If it is, we set the flag MPTCP_ADD_ADDR_IPV6 to true. Then we call
mptcp_pm_nl_add_addr_send_ack to sent out a new pure ACK packet.

In mptcp_established_options_add_addr, we check whether this is a pure
ACK packet for ADD_ADDR. If it is, we drop all other MPTCP suboptions
in this packet, only put ADD_ADDR suboption in it.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: refactor shutdown and close

We must not close the subflows before all the MPTCP level
data, comprising the DATA_FIN has been acked at the MPTCP
level, otherwise we could be unable to retransmit as needed.

__mptcp_wr_shutdown() shutdown is responsible to check for the
correct status and close all subflows. Is called by the output
path after spooling any data and at shutdown/close time.

In a similar way, __mptcp_destroy_sock() is responsible to clean-up
the MPTCP level status, and is called when the msk transition
to TCP_CLOSE.

The protocol level close() does not force anymore the TCP_CLOSE
status, but orphan the msk socket and all the subflows.
Orphaned msk sockets are forciby closed after a timeout or
when all MPTCP-level data is acked.

There is a caveat about keeping the orphaned subflows around:
the TCP stack can asynchronusly call tcp_cleanup_ulp() on them via
tcp_close(). To prevent accessing freed memory on later MPTCP
level operations, the msk acquires a reference to each subflow
socket and prevent subflow_ulp_release() from releasing the
subflow context before __mptcp_destroy_sock().

The additional subflow references are released by __mptcp_done()
and the async ULP release is detected checking ULP ops. If such
field has been already cleared by the ULP release path, the
dangling context is freed directly by __mptcp_done().

Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: fix static checker warnings in mptcp_pm_add_timer

Fix the following Smatch complaint:

net/mptcp/pm_netlink.c:213 mptcp_pm_add_timer()
warn: variable dereferenced before check 'msk' (see line 208)

net/mptcp/pm_netlink.c
207 struct mptcp_sock *msk = entry->sock;
208 struct sock *sk = (struct sock *)msk;
209 struct net *net = sock_net(sk);
^^
"msk" dereferenced here.

210
211 pr_debug("msk=%p", msk);
212
213 if (!msk)
^^^^
Too late.

214 return;
215

Fixes: 93f323b9cccc ("mptcp: add a new sysctl add_addr_timeout")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Link: https://lore.kernel.org/r/078a2ef5bdc4e3b2c25ef852461692001f426495.1604976945.git.geliangtang@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add a new sysctl add_addr_timeout

This patch added a new sysctl, named add_addr_timeout, to control the
timeout value (in seconds) of the ADD_ADDR retransmission.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: Constify mptcp_pm_ops

The only usages of mptcp_pm_ops is to assign its address to the small_ops
field of the genl_family struct, which is a const pointer, and applying
ARRAY_SIZE() on it. Make it const to allow the compiler to put it in
read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

genetlink: move to smaller ops wherever possible

Bulk of the genetlink users can use smaller ops, move them.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: retransmit ADD_ADDR when timeout

This patch implemented the retransmition of ADD_ADDR when no ADD_ADDR echo
is received. It added a timer with the announced address. When timeout
occurs, ADD_ADDR will be retransmitted.

Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add struct mptcp_pm_add_entry

Add a new struct mptcp_pm_add_entry to describe add_addr's entry.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add RM_ADDR related mibs

This patch added two new mibs for RM_ADDR, named MPTCP_MIB_RMADDR and
MPTCP_MIB_RMSUBFLOW, when the RM_ADDR suboption is received, increase
the first mib counter, when the local subflow is removed, increase the
second mib counter.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: implement mptcp_pm_remove_subflow

This patch implemented the local subflow removing function,
mptcp_pm_remove_subflow, it simply called mptcp_pm_nl_rm_subflow_received
under the PM spin lock.

We use mptcp_pm_remove_subflow to remove a local subflow, so change it's
argument from remote_id to local_id.

We check subflow->local_id in mptcp_pm_nl_rm_subflow_received to remove
a subflow.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: remove addr and subflow in PM netlink

This patch implements the remove announced addr and subflow logic in PM
netlink.

When the PM netlink removes an address, we traverse all the existing msk
sockets to find the relevant sockets.

We add a new list named anno_list in mptcp_pm_data, to record all the
announced addrs. In the traversing, we check if it has been recorded.
If it has been, we trigger the RM_ADDR signal.

We also check if this address is in conn_list. If it is, we remove the
subflow which using this local address.

Since we call mptcp_pm_free_anno_list in mptcp_destroy, we need to move
__mptcp_init_sock before the mptcp_is_enabled check in mptcp_init_sock.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: send out ADD_ADDR with echo flag

When the ADD_ADDR suboption has been received, we need to send out the same
ADD_ADDR suboption with echo-flag=1, and no HMAC.

Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add the incoming RM_ADDR support

This patch added the RM_ADDR option parsing logic:

We parsed the incoming options to find if the rm_addr option is received,
and called mptcp_pm_rm_addr_received to schedule PM work to a new status,
named MPTCP_PM_RM_ADDR_RECEIVED.

PM work got this status, and called mptcp_pm_nl_rm_addr_received to handle
it.

In mptcp_pm_nl_rm_addr_received, we closed the subflow matching the rm_id,
and updated PM counter.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: move address attribute into mptcp_addr_info

So that can be accessed easily from the subflow creation
helper. No functional change intended.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix kmalloc flag in mptcp_pm_nl_get_local_id

mptcp_pm_nl_get_local_id may be called in interrupt context, so we need to
use GFP_ATOMIC flag to allocate memory to avoid sleeping in atomic context.

[ 280.209809] BUG: sleeping function called from invalid context at mm/slab.h:498
[ 280.209812] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1680, name: kworker/1:3
[ 280.209814] INFO: lockdep is turned off.
[ 280.209816] CPU: 1 PID: 1680 Comm: kworker/1:3 Tainted: G W 5.9.0-rc3-mptcp+ #146
[ 280.209818] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 280.209820] Workqueue: events mptcp_worker
[ 280.209822] Call Trace:
[ 280.209824] <IRQ>
[ 280.209826] dump_stack+0x77/0xa0
[ 280.209829] ___might_sleep.cold+0xa6/0xb6
[ 280.209832] kmem_cache_alloc_trace+0x1d1/0x290
[ 280.209835] mptcp_pm_nl_get_local_id+0x23c/0x410
[ 280.209840] subflow_init_req+0x1e9/0x2ea
[ 280.209843] ? inet_reqsk_alloc+0x1c/0x120
[ 280.209845] ? kmem_cache_alloc+0x264/0x290
[ 280.209849] tcp_conn_request+0x303/0xae0
[ 280.209854] ? printk+0x53/0x6a
[ 280.209857] ? tcp_rcv_state_process+0x28f/0x1374
[ 280.209859] tcp_rcv_state_process+0x28f/0x1374
[ 280.209864] ? tcp_v4_do_rcv+0xb3/0x1f0
[ 280.209866] tcp_v4_do_rcv+0xb3/0x1f0
[ 280.209869] tcp_v4_rcv+0xed6/0xfa0
[ 280.209873] ip_protocol_deliver_rcu+0x28/0x270
[ 280.209875] ip_local_deliver_finish+0x89/0x120
[ 280.209877] ip_local_deliver+0x180/0x220
[ 280.209881] ip_rcv+0x166/0x210
[ 280.209885] __netif_receive_skb_one_core+0x82/0x90
[ 280.209888] process_backlog+0xd6/0x230
[ 280.209891] net_rx_action+0x13a/0x410
[ 280.209895] __do_softirq+0xcf/0x468
[ 280.209899] asm_call_on_stack+0x12/0x20
[ 280.209901] </IRQ>
[ 280.209903] ? ip_finish_output2+0x240/0x9a0
[ 280.209906] do_softirq_own_stack+0x4d/0x60
[ 280.209908] do_softirq.part.0+0x2b/0x60
[ 280.209911] __local_bh_enable_ip+0x9a/0xa0
[ 280.209913] ip_finish_output2+0x264/0x9a0
[ 280.209916] ? rcu_read_lock_held+0x4d/0x60
[ 280.209920] ? ip_output+0x7a/0x250
[ 280.209922] ip_output+0x7a/0x250
[ 280.209925] ? __ip_finish_output+0x330/0x330
[ 280.209928] __ip_queue_xmit+0x1dc/0x5a0
[ 280.209931] __tcp_transmit_skb+0xa0f/0xc70
[ 280.209937] tcp_connect+0xb03/0xff0
[ 280.209939] ? lockdep_hardirqs_on_prepare+0xe7/0x190
[ 280.209942] ? ktime_get_with_offset+0x125/0x150
[ 280.209944] ? trace_hardirqs_on+0x1c/0xe0
[ 280.209948] tcp_v4_connect+0x449/0x550
[ 280.209953] __inet_stream_connect+0xbb/0x320
[ 280.209955] ? mark_held_locks+0x49/0x70
[ 280.209958] ? lockdep_hardirqs_on_prepare+0xe7/0x190
[ 280.209960] ? __local_bh_enable_ip+0x6b/0xa0
[ 280.209963] inet_stream_connect+0x32/0x50
[ 280.209966] __mptcp_subflow_connect+0x1fd/0x242
[ 280.209972] mptcp_pm_create_subflow_or_signal_addr+0x2db/0x600
[ 280.209975] mptcp_worker+0x543/0x7a0
[ 280.209980] process_one_work+0x26d/0x5b0
[ 280.209984] ? process_one_work+0x5b0/0x5b0
[ 280.209987] worker_thread+0x48/0x3d0
[ 280.209990] ? process_one_work+0x5b0/0x5b0
[ 280.209993] kthread+0x117/0x150
[ 280.209996] ? kthread_park+0x80/0x80
[ 280.209998] ret_from_fork+0x22/0x30

Fixes: 01cacb00b35cb ("mptcp: add netlink-based PM")
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix subflow's remote_id issues

This patch set the init remote_id to zero, otherwise it will be a random
number.

Then it added the missing subflow's remote_id setting code both in
__mptcp_subflow_connect and in subflow_ulp_clone.

Fixes: 01cacb00b35cb ("mptcp: add netlink-based PM")
Fixes: ec3edaa7ca6ce ("mptcp: Add handling of outgoing MP_JOIN requests")
Fixes: f296234c98a8f ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix subflow's local_id issues

In mptcp_pm_nl_get_local_id, skc_local is the same as msk_local, so it
always return 0. Thus every subflow's local_id is 0. It's incorrect.

This patch fixed this issue.

Also, we need to ignore the zero address here, like 0.0.0.0 in IPv4. When
we use the zero address as a local address, it means that we can use any
one of the local addresses. The zero address is not a new address, we don't
need to add it to PM, so this patch added a new function address_zero to
check whether an address is the zero address, if it is, we ignore this
address.

Fixes: 01cacb00b35cb ("mptcp: add netlink-based PM")
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: consistently use NLA_POLICY_EXACT_LEN()

Change places that open-code NLA_POLICY_EXACT_LEN() to
use the macro instead, giving us flexibility in how we
handle the details of the macro.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add __init annotation on setup functions

Add the missing annotation in some setup-only
functions.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp/pm_netlink.c : add check for nla_put_in/6_addr

Normal there should be checked for nla_put_in6_addr like other
usage in net.

Detected by CoverityScan, CID# 1461639

Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Signed-off-by: Bo YU <tsu.yubo@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add some missing pr_fmt defines

Some of the mptcp logs didn't print out the format string:

[ 185.651493] DSS
[ 185.651494] data_fin=0 dsn64=0 use_map=0 ack64=1 use_ack=1
[ 185.651494] data_ack=13792750332298763796
[ 185.651495] MPTCP: msk=00000000c4b81cfc ssk=000000009743af53 data_avail=0 skb=0000000063dc595d
[ 185.651495] MPTCP: msk=00000000c4b81cfc ssk=000000009743af53 status=0
[ 185.651495] MPTCP: msk ack_seq=9bbc894565aa2f9a subflow ack_seq=9bbc894565aa2f9a
[ 185.651496] MPTCP: msk=00000000c4b81cfc ssk=000000009743af53 data_avail=1 skb=0000000012e809e1

So this patch added these missing pr_fmt defines. Then we can get the same
format string "MPTCP" in all mptcp logs like this:

[ 142.795829] MPTCP: DSS
[ 142.795829] MPTCP: data_fin=0 dsn64=0 use_map=0 ack64=1 use_ack=1
[ 142.795829] MPTCP: data_ack=8089704603109242421
[ 142.795830] MPTCP: msk=00000000133a24e0 ssk=000000002e508c64 data_avail=0 skb=00000000d5f230df
[ 142.795830] MPTCP: msk=00000000133a24e0 ssk=000000002e508c64 status=0
[ 142.795831] MPTCP: msk ack_seq=66790290f1199d9b subflow ack_seq=66790290f1199d9b
[ 142.795831] MPTCP: msk=00000000133a24e0 ssk=000000002e508c64 data_avail=1 skb=00000000de5aca2e

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add netlink-based PM

Expose a new netlink family to userspace to control the PM, setting:

- list of local addresses to be signalled.
- list of local addresses used to created subflows.
- maximum number of add_addr option to react

When the msk is fully established, the PM netlink attempts to
announce the 'signal' list via the ADD_ADDR option. Since we
currently lack the ADD_ADDR echo (and related event) only the
first addr is sent.

After exhausting the 'announce' list, the PM tries to create
subflow for each addr in 'local' list, waiting for each
connection to be completed before attempting the next one.

Idea is to add an additional PM hook for ADD_ADDR echo, to allow
the PM netlink announcing multiple addresses, in sequence.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>