[PATCH net-next 0/3] rxrpc: Tx length parameter

From: David Howells
Date: Wed Jun 07 2017 - 17:12:37 EST



Here's a set of patches that allows someone initiating a client call with
AF_RXRPC to indicate upfront the total amount of data that will be
transmitted. This will allow AF_RXRPC to encrypt directly from source
buffer to packet rather than having to copy into the buffer and only
encrypt when it's full (the encrypted portion of the packet starts with a
length and so we can't encrypt until we know what the length will be).

The three patches are:

(1) Provide a means of finding out what control message types are actually
supported. EINVAL is reported if an unsupported cmsg type is seen, so
we don't want to set the new cmsg unless we know it will be accepted.

(2) Consolidate some stuff into a struct to reduce the parameter count on
the function that parses the cmsg buffer.

(3) Introduce the RXRPC_TX_LENGTH cmsg. This can be provided on the first
sendmsg() that contributes data to a client call request or a service
call reply. If provided, the user must provide exactly that amount of
data or an error will be incurred.

Changes in version 2:

(*) struct rxrpc_send_params::tx_total_len should be s64 not u64. Thanks to
Julia Lawall for reporting this.

The patches can be found here also:

http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-rewrite

Tagged thusly:

git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git
rxrpc-rewrite-20170607-v2

David
---
David Howells (3):
rxrpc: Provide a getsockopt call to query what cmsgs types are supported
rxrpc: Consolidate sendmsg parameters
rxrpc: Provide a cmsg to specify the amount of Tx data for a call


Documentation/networking/rxrpc.txt | 43 +++++++++++
fs/afs/rxrpc.c | 18 +++++
include/linux/rxrpc.h | 25 ++++---
include/net/af_rxrpc.h | 2 +
net/rxrpc/af_rxrpc.c | 35 +++++++++
net/rxrpc/ar-internal.h | 3 +
net/rxrpc/call_object.c | 3 +
net/rxrpc/sendmsg.c | 135 +++++++++++++++++++++++++-----------
8 files changed, 207 insertions(+), 57 deletions(-)