13 Commits

Author SHA1 Message Date
Jeremy Kerr
97f09abffc mctp: Do inits as a subsys_initcall
In a future change, we'll want to provide a registration call for
mctp-specific devices. This requires us to have the networks established
before device driver inits, so run the core init as a subsys_initcall.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-29 11:00:11 +01:00
Jeremy Kerr
4f9e1ba6de mctp: Add tracepoints for tag/key handling
The tag allocation, release and bind events are somewhat opaque outside
the kernel; this change adds a few tracepoints to assist in
instrumentation and debugging.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-29 11:00:11 +01:00
Jeremy Kerr
7b14e15ae6 mctp: Implement a timeout for tags
Currently, a MCTP (local-eid,remote-eid,tag) tuple is allocated to a
socket on send, and only expires when the socket is closed.

This change introduces a tag timeout, freeing the tuple after a fixed
expiry - currently six seconds. This is greater than (but close to) the
max response timeout in upper-layer bindings.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-29 11:00:11 +01:00
Jeremy Kerr
73c618456d mctp: locking, lifetime and validity changes for sk_keys
We will want to invalidate sk_keys in a future change, which will
require a boolean flag to mark invalidated items in the socket & net
namespace lists. We'll also need to take a reference to keys, held over
non-atomic contexts, so we need a refcount on keys also.

This change adds a validity flag (currently always true) and refcount to
struct mctp_sk_key.  With a refcount on the keys, using RCU no longer
makes much sense; we have exact indications on the lifetime of keys. So,
we also change the RCU list traversal to a locked implementation.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-29 11:00:11 +01:00
Colin Ian King
df7ba0eb25 mctp: remove duplicated assignment of pointer hdr
The pointer hdr is being initialized and also re-assigned with the
same value from the call to function mctp_hdr. Static analysis reports
that the initializated value is unused. The second assignment is
duplicated and can be removed.

Addresses-Coverity: ("Unused value").
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-05 10:56:01 +01:00
Matt Johnston
03f2bbc4ee mctp: Allow per-netns default networks
Currently we have a compile-time default network
(MCTP_INITIAL_DEFAULT_NET). This change introduces a default_net field
on the net namespace, allowing future configuration for new interfaces.

Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29 15:06:50 +01:00
Jeremy Kerr
4a992bbd36 mctp: Implement message fragmentation & reassembly
This change implements MCTP fragmentation (based on route & device MTU),
and corresponding reassembly.

The MCTP specification only allows for fragmentation on the originating
message endpoint, and reassembly on the destination endpoint -
intermediate nodes do not need to reassemble/refragment.  Consequently,
we only fragment in the local transmit path, and reassemble
locally-bound packets. Messages are required to be in-order, so we
simply cancel reassembly on out-of-order or missing packets.

In the fragmentation path, we just break up the message into MTU-sized
fragments; the skb structure is a simple copy for now, which we can later
improve with a shared data implementation.

For reassembly, we keep track of incoming message fragments using the
existing tag infrastructure, allocating a key on the (src,dest,tag)
tuple, and reassembles matching fragments into a skb->frag_list.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29 15:06:50 +01:00
Jeremy Kerr
833ef3b91d mctp: Populate socket implementation
Start filling-out the socket syscalls: bind, sendmsg & recvmsg.

This requires an input route implementation, so we add to
mctp_route_input, allowing lookups on binds & message tags. This just
handles single-packet messages at present, we will add fragmentation in
a future change.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29 15:06:50 +01:00
Matt Johnston
4d8b931928 mctp: Add neighbour implementation
Add an initial neighbour table implementation, to be used in the route
output path.

Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29 15:06:50 +01:00
Jeremy Kerr
889b7da23a mctp: Add initial routing framework
Add a simple routing table, and a couple of route output handlers, and
the mctp packet_type & handler.

Includes changes from Matt Johnston <matt@codeconstruct.com.au>.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29 15:06:50 +01:00
Jeremy Kerr
583be982d9 mctp: Add device handling and netlink interface
This change adds the infrastructure for managing MCTP netdevices; we add
a pointer to the AF_MCTP-specific data to struct netdevice, and hook up
the rtnetlink operations for adding and removing addresses.

Includes changes from Matt Johnston <matt@codeconstruct.com.au>.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29 15:06:50 +01:00
Jeremy Kerr
8f601a1e4f mctp: Add base socket/protocol definitions
Add an empty socket implementation, plus initialisation/destruction
handlers.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29 15:06:49 +01:00
Jeremy Kerr
bc49d8169a mctp: Add MCTP base
Add basic Kconfig, an initial (empty) af_mctp source object, and
{AF,PF}_MCTP definitions, and the required definitions for a new
protocol type.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29 15:06:49 +01:00