Commit Graph

17 Commits

Author SHA1 Message Date
Gerrit Renker
89858ad143 dccp ccid-3: use per-route RTO or TCP RTO as fallback
This makes RTAX_RTO_MIN also available to CCID-3, replacing the compile-time
RTO lower bound with a per-route tunable value.

The original Kconfig option solved the problem that a very low RTT (in the
order of HZ) can trigger too frequent and unnecessary reductions of the
sending rate.

This tunable does not affect the initial RTO value of 2 seconds specified in
RFC 5348, section 4.2 and Appendix B. But like the hardcoded Kconfig value,
it allows to adapt to network conditions.

The same effect as the original Kconfig option of 100ms is now achieved by

> ip route replace to unicast 192.168.0.0/24 rto_min 100j dev eth0

(assuming HZ=1000).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-30 13:45:28 -07:00
Gerrit Renker
aa1b1ff099 net-next-2.6 [PATCH 1/1] dccp: ccids whitespace-cleanup / CodingStyle
No code change, cosmetical changes only:

 * whitespace cleanup via scripts/cleanfile,
 * remove self-references to filename at top of files,
 * fix coding style (extraneous brackets),
 * fix documentation style (kernel-doc-nano-HOWTO).

Thanks are due to Ivo Augusto Calado who raised these issues by
submitting good-quality patches.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-14 17:02:54 -07:00
Gerrit Renker
4dbc242ed3 dccp ccid-3: Fix RFC reference
Thanks to Wei and Arnaldo for pointing out the correct
new reference for CCID-3.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-11 00:17:22 -08:00
Gerrit Renker
129fa44785 dccp: Integrate the TFRC library with DCCP
This patch integrates the TFRC library, which is a dependency of CCID-3 (and
CCID-4), with the new use of CCIDs in the DCCP module.		

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-04 21:45:33 -08:00
Gerrit Renker
ddebc973c5 dccp: Lockless integration of CCID congestion-control plugins
Based on Arnaldo's earlier patch, this patch integrates the standardised
CCID congestion control plugins (CCID-2 and CCID-3) of DCCP with dccp.ko:

 * enables a faster connection path by eliminating the need to always go 
   through the CCID registration lock;

 * updates the implementation to use only a single array whose size equals
   the number of configured CCIDs instead of the maximum (256);

 * since the CCIDs are now fixed array elements, synchronization is no
   longer needed, simplifying use and implementation.

CCID-2 is suggested as minimum for a basic DCCP implementation (RFC 4340, 10);
CCID-3 is a standards-track CCID supported by RFC 4342 and RFC 5348.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-04 21:42:53 -08:00
Gerrit Renker
c40616c597 [TFRC]: Provide central source file and debug facility
This patch changes the tfrc_lib module in the following manner:

 (1) a dedicated tfrc source file to call the packet history &
     loss interval init/exit functions.
 (2) a dedicated tfrc_pr_debug macro with toggle switch `tfrc_debug'.

Commiter note: renamed tfrc_module.c to tfrc.c, and made CONFIG_IP_DCCP_CCID3
select IP_DCCP_TFRC_LIB.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:56:39 -08:00
Gerrit Renker
6d57b43bf8 [DCCP]: Remove redundant dependency on IP_DCCP
This cleans up the consequences of an earlier patch which
introduced the `if IP_DCCP' clause into net/dccp/Kconfig.

The CCID Kconfig menu is sourced within this clause; as a
consequence, all tests of type `depends on IP_DCCP' are now
redundant.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:46 -08:00
Gerrit Renker
e333b3edc4 [DCCP]: Promote CCID2 as default CCID
This patch addresses the following problems:

 1. DCCP relies for its proper functioning on having at least one CCID module
    enabled (as in TCP plugable congestion control). Currently it is possible to
    disable both CCIDs and thus leave the DCCP module in a compiled, but entirely
    non-functional state: no sockets can be created when no CCID is available.
    Furthermore, the protocol is (again like TCP) not intended to be used without
    CCIDs. Last, a non-empty CCID list is needed for doing CCID feature negotiation.

 2. Internally the default CCID that is advertised by the Linux host is set to CCID2
    (DCCPF_INITIAL_CCID in include/linux/dccp.h). Disabling CCID2 in the Kconfig
    menu without changing the defaults leads to a failure `module not found' when
    trying to load the dccp module (which internally tries to load the default CCID).

 3. The specification (RFC 4340, sec. 10) treats CCID2 somewhat like a
    `minimum common denominator'; the specification says that:

    * "New connections start with CCID 2 for both endpoints"

    * "A DCCP implementation intended for general use, such as an implementation in a
       general-purpose operating system kernel, SHOULD implement at least CCID 2.
       The intent is to make CCID 2 broadly available for interoperability [...]"

    Providing CCID2 as minimum-required CCID (like Reno/Cubic in TCP) thus seems reasonable.

Hence this patch automatically selects CCID2 when DCCP is enabled. Documentation also added.

Discussions with Ian McDonald on this subject are gratefully acknowledged.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:46 -08:00
Gerrit Renker
8a508ac26e [DCCP]: Use higher RTO default for CCID3
The TFRC nofeedback timer normally expires after the maximum of 4
RTTs and twice the current send interval (RFC 3448, 4.3). On LANs
with a small RTT this can mean a high processing load and reduced
performance, since then the nofeedback timer is triggered very
frequently.

This patch provides a configuration option to set the bound for the
nofeedback timer, using as default 100 milliseconds.

By setting the configuration option to 0, strict RFC 3448 behaviour
can be enforced for the nofeedback timer.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-03 14:50:23 -02:00
Gerrit Renker
56724aa434 [DCCP]: Add CCID3 debug support to Kconfig
This adds a CCID3 debug option to the configuration menu
which is missing in Kconfig, but already used by the code.

CCID 2 already provides such an entry.

To enable debugging, set CONFIG_IP_DCCP_CCID3_DEBUG=y

NOTE: The use of ccid3_{t,r}x_state_name is safe, since
      now only enum values can appear.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02 21:24:36 -08:00
Gerrit Renker
84116716cc [DCCP]: enable debug messages also for static builds
This patch
  * makes debugging (when configured) work both for static / module build
  * provides generic debugging macros for use in other DCCP / CCID modules
  * adds missing information about debug parameters to Kconfig
  * performs some code tidy-up

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02 21:24:35 -08:00
Gerrit Renker
0e64e94e47 [DCCP]: Update documentation references.
Updates the references to spec documents throughout the code, taking into
account that

* the DCCP, CCID 2, and CCID 3 drafts all became RFCs in March this year

* RFC 1063 was obsoleted by RFC 1191

* draft-ietf-tcpimpl-pmtud-0x.txt was published as an Informational
  RFC, RFC 2923 on 2000-09-22.

All references verified.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-24 16:17:51 -07:00
Andrea Bittau
8d424f6ca2 [DCCP] CCID2: Add Kconfig option for CCID2 debug
Allow the user to choose whether or not to enable CCID2 debugging via
Kconfig.

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22 15:19:39 -07:00
Arnaldo Carvalho de Melo
057fc6755a [DCCP]: Kconfig tidy up
Make CCID2 and CCID3 default to what was selected for DCCP and use the
standard short description for the CCIDs (TCP-Like & TCP-Friendly).

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 19:24:22 -08:00
Andrea Bittau
2a91aa3967 [DCCP] CCID2: Initial CCID2 (TCP-Like) implementation
Original work by Andrea Bittau, Arnaldo Melo cleaned up and fixed several
issues on the merge process.

For now CCID2 was turned the default for all SOCK_DCCP connections, but this
will be remedied soon with the merge of the feature negotiation code.

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 17:41:47 -08:00
Arnaldo Carvalho de Melo
5cea0ddce5 [DCCP]: Introduce dccp_tfrc_lib module with net/dccp/ccids/lib/*.c
I'll now take a look at the other proposed TFRC DCCP CCIDs to find
more code that is now in ccid3.c and move to this module, the loss
event rate, calc_X, etc most probably will be moved there.

The main goal of these changes is to pave the way for the
implementation of more TFRC based DCCP CCIDs and to shrink ccid3.c,
reducing its complexity and helping in getting it rock solid.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:12:33 -07:00
Arnaldo Carvalho de Melo
7c657876b6 [DCCP]: Initial implementation
Development to this point was done on a subversion repository at:

http://oops.ghostprotocols.net:81/cgi-bin/viewcvs.cgi/dccp-2.6/

This repository will be kept at this site for the foreseable future,
so that interested parties can see the history of this code,
attributions, etc.

If I ever decide to take this offline I'll provide the full history at
some other suitable place.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:49:46 -07:00