[PATCH 0/8] AF_RXRPC socket family and AFS rewrite [try #2]

[David Howells <dhowells@redhat.com>]

The first of these patches together provide secure client-side RxRPC
connectivity as a Linux kernel socket family.  Only the RxRPC transport/session
side is supplied - the presentation side (marshalling the data) is left to the
client.  Copies of the patches can be found here:

	http://people.redhat.com/~dhowells/rxrpc/series
	http://people.redhat.com/~dhowells/rxrpc/01-move-skb-generic.diff
	http://people.redhat.com/~dhowells/rxrpc/02-timers.diff
	http://people.redhat.com/~dhowells/rxrpc/03-keys.diff
	http://people.redhat.com/~dhowells/rxrpc/04-af_rxrpc.diff

Further patches make the in-kernel AFS filesystem use AF_RXRPC and delete the
old RxRPC implementation:

	http://people.redhat.com/~dhowells/rxrpc/05-afs-cleanup.diff
	http://people.redhat.com/~dhowells/rxrpc/06-af_rxrpc-kernel.diff
	http://people.redhat.com/~dhowells/rxrpc/07-af_rxrpc-afs.diff
	http://people.redhat.com/~dhowells/rxrpc/08-af_rxrpc-delete-old.diff

The userspace access methods make use of the control data passed to/by
sendmsg() and recvmsg().  See the three simple test programs:

	http://people.redhat.com/~dhowells/rxrpc/klog.c
	http://people.redhat.com/~dhowells/rxrpc/rxrpc.c
	http://people.redhat.com/~dhowells/rxrpc/listen.c

TODO:

 (*) Make certain parameters (such as connection timeouts) userspace
     configurable.

 (*) Make userspace utilities use it; librxrpc.

 (*) Userspace documentation.

 (*) KerberosV security.

Changes:

 (*) SOCK_RPC has been removed.  SOCK_DGRAM is now used instead.

 (*) I've add a facility whereby calls can be made to destinations other than
     the connect() address of a client socket by making use of msg_name in the
     msghdr struct when using sendmsg() to send the first data packet of a
     call.  Indeed, a client socket need not be connected before being used
     so.

 (*) I've also added a facility whereby client calls may also be made on
     server sockets, again by using msg_name in the msghdr struct.  In such a
     case, the server's local transport endpoint is used.

 (*) I've made the write buffer space check available to various callers
     (sk_write_space) and implemented poll support.

 (*) Rewrote rxrpc_recvmsg().  It now concatenates adjacent data messages from
     the same call when delivering them.

 (*) Updated the documentation to include notes on recvmsg, cover control
     messages and cover SOL_RXRPC-level socket options.

 (*) Provided an in-kernel interface to give in-kernel utilities easier access
     to the facility.

 (*) Made fs/afs/ use it.

 (*) Deleted the old contents of net/rxrpc/.

 (*) Use the scatterlist interface to the crypto API for now.  The patch that
     added the direct access interface conflicts with patches Herbert Xu is
     producing, so I've dropped it for the moment.

 (*) Moved a bug fix to make secure connection reuse from the af_rxrpc-kernel
     patch to the af_rxrpc main patch.

David