commit a663bac71a2f0b3ac6c373168ca57b2a6e6381aa upstream.

From the MCTP Base specification (DSP0236 v1.2.1), the first byte of
the MCTP header contains a 4 bit reserved field, and 4 bit version.

On our current receive path, we require those 4 reserved bits to be
zero, but the 9500-8i card is non-conformant, and may set these
reserved bits.

DSP0236 states that the reserved bits must be written as zero, and
ignored when read. While the device might not conform to the former,
we should accept these message to conform to the latter.

Relax our check on the MCTP version byte to allow non-zero bits in the
reserved field.

Fixes: 889b7da23abf ("mctp: Add initial routing framework")
Signed-off-by: Yuan Zhaoming <yuanzm2@lenovo.com>
Cc: stable@vger.kernel.org
Acked-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://patch.msgid.link/20260417141340.5306-1-yuanzhaoming901030@126.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Prior to calling bind() a program may call connect() on a socket to
restrict to a remote peer address.

Using connect() is the normal mechanism to specify a remote network
peer, so we use that here. In MCTP connect() is only used for bound
sockets - send() is not available for MCTP since a tag must be provided
for each message.

The smctp_type must match between connect() and bind() calls.

Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Link: https://patch.msgid.link/20250710-mctp-bind-v4-6-8ec2f6460c56@codeconstruct.com.au
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

This change allows for gateway routing, where a route table entry
may reference a routable endpoint (by network and EID), instead of
routing directly to a netdevice.

We add support for a RTM_GATEWAY attribute for netlink route updates,
with an attribute format of:

    struct mctp_fq_addr {
        unsigned int net;
        mctp_eid_t eid;
    }

- we need the net here to uniquely identify the target EID, as we no
longer have the device reference directly (which would provide the net
id in the case of direct routes).

This makes route lookups recursive, as a route lookup that returns a
gateway route must be resolved into a direct route (ie, to a device)
eventually. We provide a limit to the route lookups, to prevent infinite
loop routing.

The route lookup populates a new 'nexthop' field in the dst structure,
which now specifies the key for the neighbour table lookup on device
output, rather than using the packet destination address directly.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://patch.msgid.link/20250702-dev-forwarding-v5-13-1468191da8a4@codeconstruct.com.au
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Now that we have the dst->haddr populated by sendmsg (when extended
addressing is in use), we no longer need to stash the link-layer address
in the skb->cb.

Instead, only use skb->cb for incoming lladdr data.

While we're at it: remove cb->src, as was never used.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://patch.msgid.link/20250702-dev-forwarding-v5-4-1468191da8a4@codeconstruct.com.au
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

This change adds a struct mctp_dst, representing the result of a routing
lookup. This decouples the struct mctp_route from the actual
implementation of a routing operation.

This will allow for future routing changes which may require more
involved lookup logic, such as gateway routing - which may require
multiple traversals of the routing table.

Since we only use the struct mctp_route at lookup time, we no longer
hold routes over a routing operation, as we only need it to populate the
dst. However, we do hold the dev while the dst is active.

This requires some changes to the route test infrastructure, as we no
longer have a mock route to handle the route output operation, and
transient dsts are created by the routing code, so we can't override
them as easily.

Instead, we use kunit->priv to stash a packet queue, and a custom
dst_output function queues into that packet queue, which we can use for
later expectations.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://patch.msgid.link/20250702-dev-forwarding-v5-3-1468191da8a4@codeconstruct.com.au
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The void * cast in mctp_cb is unnecessary as it's already been done
at the start of the function.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Jeremy Kerr <jk@codeconstruct.com.au>

Link: https://patch.msgid.link/Z9PwOQeBSYlgZlHq@gondor.apana.org.au
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

MCTP control protocol implementations are transport binding dependent.
Endpoint discovery is mandatory based on transport binding.
Message timing requirements are specified in each respective transport
binding specification.

However, we currently have no means to get this information from MCTP
links.

Add a IFLA_MCTP_PHYS_BINDING netlink link attribute, which represents
the transport type using the DMTF DSP0239-defined type numbers, returned
as part of RTM_GETLINK data.

We get an IFLA_MCTP_PHYS_BINDING attribute for each MCTP link, for
example:

- 0x00 (unspec) for loopback interface;
- 0x01 (SMBus/I2C) for mctpi2c%d interfaces; and
- 0x05 (serial) for mctpserial%d interfaces.

Signed-off-by: Khang Nguyen <khangng@os.amperecomputing.com>
Reviewed-by: Matt Johnston <matt@codeconstruct.com.au>
Link: https://patch.msgid.link/20241105071915.821871-1-khangng@os.amperecomputing.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Since introduced, mctp has been ignoring the returned value of
rtnl_register_module(), which could fail silently.

Handling the error allows users to view a module as an all-or-nothing
thing in terms of the rtnetlink functionality.  This prevents syzkaller
from reporting spurious errors from its tests, where OOM often occurs
and module is automatically loaded.

Let's handle the errors by rtnl_register_many().

Fixes: 583be982d934 ("mctp: Add device handling and netlink interface")
Fixes: 831119f88781 ("mctp: Add neighbour netlink interface")
Fixes: 06d2f4c583a7 ("mctp: Add netlink route management")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Cross-merge networking fixes after downstream PR.

Conflicts:

net/mptcp/protocol.c
  adf1bb78dab5 ("mptcp: fix snd_wnd initialization for passive socket")
  9426ce476a70 ("mptcp: annotate lockless access for RX path fields")
https://lore.kernel.org/all/20240228103048.19255709@canb.auug.org.au/

Adjacent changes:

drivers/dpll/dpll_core.c
  0d60d8df6f49 ("dpll: rely on rcu for netdev_dpll_pin()")
  e7f8df0e81bf ("dpll: move xa_erase() call in to match dpll_pin_alloc() error path order")

drivers/net/veth.c
  1ce7d306ea63 ("veth: try harder when allocating queue memory")
  0bef512012b1 ("net: add netdev_lockdep_set_classes() to virtual drivers")

drivers/net/wireless/intel/iwlwifi/mvm/d3.c
  8c9bef26e98b ("wifi: iwlwifi: mvm: d3: implement suspend with MLO")
  78f65fbf421a ("wifi: iwlwifi: mvm: ensure offloading TID queue exists")

net/wireless/nl80211.c
  f78c1375339a ("wifi: nl80211: reject iftype change with mesh ID change")
  414532d8aa89 ("wifi: cfg80211: use IEEE80211_MAX_MESH_ID_LEN appropriately")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Currently, mctp_local_output only takes ownership of skb on success, and
we may leak an skb if mctp_local_output fails in specific states; the
skb ownership isn't transferred until the actual output routing occurs.

Instead, make mctp_local_output free the skb on all error paths up to
the route action, so it always consumes the passed skb.

Fixes: 833ef3b91de6 ("mctp: Populate socket implementation")
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240220081053.1439104-1-jk@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>