Commit graph

8 commits

Author SHA1 Message Date
David Howells
c31a25e1db kcm: Send multiple frags in one sendmsg()
Rewrite the AF_KCM transmission loop to send all the fragments in a single
skb or frag_list-skb in one sendmsg() with MSG_SPLICE_PAGES set.  The list
of fragments in each skb is conveniently a bio_vec[] that can just be
attached to a BVEC iter.

Note: I'm working out the size of each fragment-skb by adding up bv_len for
all the bio_vecs in skb->frags[] - but surely this information is recorded
somewhere?  For the skbs in head->frag_list, this is equal to
skb->data_len, but not for the head.  head->data_len includes all the tail
frags too.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Tom Herbert <tom@herbertland.com>
cc: Tom Herbert <tom@quantonium.net>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-12 21:13:23 -07:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Tom Herbert
9b73896a81 kcm: Use stream parser
Adapt KCM to use the stream parser. This mostly involves removing
the RX handling and setting up the strparser using the interface.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-17 19:36:23 -04:00
Arnd Bergmann
f720d0caa0 kcm: mark helper functions inline
The stub helper functions for the newly added kcm_proc_init/exit interfaces
are defined as 'static' in a header file, which leads to build warnings for
each file that includes them without calling them:

include/net/kcm.h:183:12: error: 'kcm_proc_init' defined but not used [-Werror=unused-function]
include/net/kcm.h:184:13: error: 'kcm_proc_exit' defined but not used [-Werror=unused-function]

This marks the two functions as 'static inline' instead, which avoids the
warnings and is obviously what was meant here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: cd6e111bf5 ("kcm: Add statistics and proc interfaces")
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-10 14:42:03 -05:00
Tom Herbert
29152a34f7 kcm: Add receive message timeout
This patch adds receive timeout for message assembly on the attached TCP
sockets. The timeout is set when a new messages is started and the whole
message has not been received by TCP (not in the receive queue). If the
completely message is subsequently received the timer is cancelled, if the
timer expires the RX side is aborted.

The timeout value is taken from the socket timeout (SO_RCVTIMEO) that is
set on a TCP socket (i.e. set by get sockopt before attaching a TCP socket
to KCM.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09 16:36:15 -05:00
Tom Herbert
7ced95ef52 kcm: Add memory limit for receive message construction
Message assembly is performed on the TCP socket. This is logically
equivalent of an application that performs a peek on the socket to find
out how much memory is needed for a receive buffer. The receive socket
buffer also provides the maximum message size which is checked.

The receive algorithm is something like:

   1) Receive the first skbuf for a message (or skbufs if multiple are
      needed to determine message length).
   2) Check the message length against the number of bytes in the TCP
      receive queue (tcp_inq()).
	- If all the bytes of the message are in the queue (incluing the
	  skbuf received), then proceed with message assembly (it should
	  complete with the tcp_read_sock)
        - Else, mark the psock with the number of bytes needed to
	  complete the message.
   3) In TCP data ready function, if the psock indicates that we are
      waiting for the rest of the bytes of a messages, check the number
      of queued bytes against that.
        - If there are still not enough bytes for the message, just
	  return
        - Else, clear the waiting bytes and proceed to receive the
	  skbufs.  The message should now be received in one
	  tcp_read_sock

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09 16:36:15 -05:00
Tom Herbert
cd6e111bf5 kcm: Add statistics and proc interfaces
This patch adds various counters for KCM. These include counters for
messages and bytes received or sent, as well as counters for number of
attached/unattached TCP sockets and other error or edge events.

The statistics are exposed via a proc interface. /proc/net/kcm provides
statistics per KCM socket and per psock (attached TCP sockets).
/proc/net/kcm_stats provides aggregate statistics.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09 16:36:14 -05:00
Tom Herbert
ab7ac4eb98 kcm: Kernel Connection Multiplexor module
This module implements the Kernel Connection Multiplexor.

Kernel Connection Multiplexor (KCM) is a facility that provides a
message based interface over TCP for generic application protocols.
With KCM an application can efficiently send and receive application
protocol messages over TCP using datagram sockets.

For more information see the included Documentation/networking/kcm.txt

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09 16:36:14 -05:00