Date:	Thu, 11 Sep 2014 10:29:13 +0200
From:	<richard.alpe@...csson.com>
To:	<netdev@...r.kernel.org>
CC:	<tipc-discussion@...ts.sourceforge.net>,
	Richard Alpe <richard.alpe@...csson.com>
Subject: [PATCH net-next 00/14] tipc: new netlink API

From: Richard Alpe <richard.alpe@...csson.com>

This is a new netlink API for TIPC. It's intended to replace the
existing ASCII API. It utilizes many of the standard netlink
functionalities in the kernel, such as attribute nesting and
input polices.

There are a couple of reasons for this rewrite. The main and most
easily justifiable is that the existing API doesn't scale.  Meaning
that a TIPC cluster with a larger amount of nodes, publications or
ports will rapidly exceed what the exiting API can handle. Resulting
in truncated or corrupt responses. In addition to this, the existing
ASCII API rarely uses "standard" kernel functions and has several
tipc specific functions for sanity checking and string formating.

The new API utilizes standard function for pushing data to socket
buffers and netlink attribute nesting to logically group data.
The new API can handle an arbitrary amount of data for things that
are likely to scale up as the TIPC usage and/or cluster size
increases.

A new user-space tool has been developed to work with this new API.
It is called "tipc" and is part of the "tipc-utils" package that
comes with many Linux distributions.  The new "tipc" tool utilizes
standard functions from libnl to format, send, receive and process
messages. The tool has borrowed design philosophies from git and the
ip tool. Making the syntax resemble that of ip whiles its strong
modularity resembles that of git.

The existing tool for managing TIPC, "tipc-config" remains in the
package, but when built for kernels that has this new API it is
replaced by a script-based wrapper that maps the old syntax to the
new tool. This way, backwards compatibility is mostly preserved.

MORE ABOUT THE CODE

The main challenge here is to handle the case where the data is of
arbitrary size. This was largely neglected in the old API design.
For example when there is a lot of ports that has a large amount of
associated publications. In this specific case we can't assume that
all ports nor for that matter all the publications can fit inside a
single netlink message. Sending everything in one batch isn't an
option as we need to yield for the socket layer to cope.

This is solved by using the standard netlink callback for dumping
data and releasing the locks when the netlink message is full. The
dumping mechanism gets us back and we keep a reference (logical) to
where we where when the message became full. This means that we are
not "atomic", what is retrieved by user-space isn't a snapshot at a
certain time but rather a continuously updated data set. In the case
where we can't find our way back i.e. our logical reference are gone
we set a standard flag (NLM_F_DUMP_INTR) to tell user-space that the
dump was interrupted.

Richard Alpe (14):
  tipc: add bearer disable/enable to new netlink api
  tipc: add bearer get/dump to new netlink api
  tipc: add bearer set to new netlink api
  tipc: add sock dump to new netlink api
  tipc: add link get/dump to new netlink api
  tipc: add link set to new netlink api
  tipc: add link stat reset to new netlink api
  tipc: add media get/dump to new netlink api
  tipc: add media set to new netlink api
  tipc: add node get/dump to new netlink api
  tipc: add net dump to new netlink api
  tipc: add net set to new netlink api
  tipc: add name table dump to new netlink api
  tipc: remove old ASCII netlink API

 include/uapi/linux/tipc_config.h |  478 ++++++++++--------------
 net/tipc/Makefile                |    2 +-
 net/tipc/bcast.c                 |  130 +++++--
 net/tipc/bcast.h                 |    4 +-
 net/tipc/bearer.c                |  510 ++++++++++++++++++++++----
 net/tipc/bearer.h                |   15 +-
 net/tipc/config.c                |  342 -----------------
 net/tipc/config.h                |   67 ----
 net/tipc/core.c                  |    3 +-
 net/tipc/link.c                  |  746 +++++++++++++++++++++++---------------
 net/tipc/link.h                  |   14 +-
 net/tipc/log.c                   |    1 -
 net/tipc/name_table.c            |  375 +++++++++----------
 net/tipc/name_table.h            |    5 +-
 net/tipc/net.c                   |  107 +++++-
 net/tipc/net.h                   |    8 +-
 net/tipc/netlink.c               |  129 +++++--
 net/tipc/netlink.h               |   47 +++
 net/tipc/node.c                  |  209 +++++------
 net/tipc/node.h                  |    6 +-
 net/tipc/socket.c                |  236 ++++++++----
 net/tipc/socket.h                |    3 +-
 22 files changed, 1913 insertions(+), 1524 deletions(-)
 delete mode 100644 net/tipc/config.c
 delete mode 100644 net/tipc/config.h
 create mode 100644 net/tipc/netlink.h

-- 
1.7.10.4

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