This change adds a couple of new ioctls for mctp sockets:
SIOCMCTPALLOCTAG and SIOCMCTPDROPTAG. These ioctls provide facilities
for explicit allocation / release of tags, overriding the automatic
allocate-on-send/release-on-reply and timeout behaviours. This allows
userspace more control over messages that may not fit a simple
request/response model.
In order to indicate a pre-allocated tag to the sendmsg() syscall, we
introduce a new flag to the struct sockaddr_mctp.smctp_tag value:
MCTP_TAG_PREALLOC.
Additional changes from Jeremy Kerr <jk@codeconstruct.com.au>.
Contains a fix that was:
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use the more precise __kernel_sa_family_t for smctp_family, to match
struct sockaddr.
Also, use an unsigned int for the network member; negative networks
don't make much sense. We're already using unsigned for mctp_dev and
mctp_skb_cb, but need to change mctp_sock to suit.
Fixes: 60fc639816 ("mctp: Add sockaddr_mctp to uapi")
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Acked-by: Eugene Syromiatnikov <esyr@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Describe common flows and refcounting behaviour.
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change adds a brief document about the sockets API provided for
sending and receiving MCTP messages from userspace.
This is roughly based on the OpenBMC design document, at:
https://github.com/openbmc/docs/blob/master/designs/mctp/mctp-kernel.md
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Matt Johnston