Re: dccp-test-tree [Patch 1/1] "UDP-like" CCID sample kernel module

[Ivo Calado <ivocalado@embedded.ufcg.edu.br>]

On Mon, Feb 15, 2010 at 03:09, Gerrit Renker <gerrit@erg.abdn.ac.uk> wrote:
> This patch is for the dccp test tree at
>  git://eden-feed.erg.abdn.ac.uk/dccp_exp [subtree 'dccp']
>
> The actual 'module' is only 5 lines long.
>>>>>>>>>>>>>>>>>>>>>> Patch <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
> dccp: sample kernel module, NULL-CCID ("UDP-like")
>
> This implements an experimental CCID which does not do any congestion control,
> i.e. "UDP-like".
>
> This is an experimental CCID. It is not meant for actual deployment, but
> rather as sample kernel code, providing a worked example of how to add a
> new CCID module.
>
> Since CCID-0 is reserved (RFC 4340, table 5), this experimental NULL CCID uses
> the first available experimental CCID, CCID-248 (RFC 4340, 19.5).
>
> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
> ---
>  include/linux/dccp.h   |    7 +++++++
>  net/dccp/Makefile      |    1 +
>  net/dccp/ccid.c        |    3 +++
>  net/dccp/ccid.h        |    3 +++
>  net/dccp/ccids/Kconfig |   12 ++++++++++++
>  net/dccp/ccids/ccid0.c |   27 +++++++++++++++++++++++++++
>  net/dccp/feat.c        |   17 ++++++++++++++++-
>  7 files changed, 69 insertions(+), 1 deletion(-)
>
> --- a/include/linux/dccp.h
> +++ b/include/linux/dccp.h
> @@ -177,6 +177,13 @@ enum {
>  enum {
>        DCCPC_CCID2 = 2,
>        DCCPC_CCID3 = 3,
> +       /*
> +        * CCIDs 248-255 below are permanently reserved for
> +        * experimental and testing use (RFC 4340, 19.5).
> +        */
> +#define DCCPC_TESTING_MIN      248
> +#define DCCPC_TESTING_MAX      255
> +       DCCPC_CCID_ZERO = DCCPC_TESTING_MIN,
>  };
>
>  /* DCCP features (RFC 4340 section 6.4) */
> --- /dev/null
> +++ b/net/dccp/ccids/ccid0.c
> @@ -0,0 +1,27 @@
> +/*
> + *  CCID-ZERO - UDP-like congestion control
> + *
> + *  This is a sample kernel module, used for testing and development, but not
> + *  for actual deployment. The CCID number is taken from the range of CCIDs
> + *  set apart for testing and experimenting.
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or
> + *  (at your option) any later version.
> + *
> + *  This program is distributed in the hope that it will be useful,
> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + *  GNU General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License
> + *  along with this program; if not, write to the Free Software
> + *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
> + */
> +#include "../ccid.h"
> +
> +struct ccid_operations ccid0_ops = {
> +       .ccid_id        = DCCPC_CCID_ZERO,
> +       .ccid_name      = "UDP-like transport"
> +};
> --- a/net/dccp/ccid.c
> +++ b/net/dccp/ccid.c
> @@ -19,6 +19,9 @@ static struct ccid_operations *ccids[] =
>  #ifdef CONFIG_IP_DCCP_CCID3
>        &ccid3_ops,
>  #endif
> +#ifdef CONFIG_IP_DCCP_CCID0
> +       &ccid0_ops,
> +#endif
>  };
>
>  static struct ccid_operations *ccid_by_number(const u8 id)
> --- a/net/dccp/ccid.h
> +++ b/net/dccp/ccid.h
> @@ -91,6 +91,9 @@ struct ccid_operations {
>                                                 int __user *optlen);
>  };
>
> +#ifdef CONFIG_IP_DCCP_CCID0
> +extern struct ccid_operations ccid0_ops;
> +#endif
>  extern struct ccid_operations ccid2_ops;
>  #ifdef CONFIG_IP_DCCP_CCID3
>  extern struct ccid_operations ccid3_ops;
> --- a/net/dccp/feat.c
> +++ b/net/dccp/feat.c
> @@ -620,7 +620,8 @@ static u8 dccp_feat_is_valid_sp_val(u8 f
>  {
>        switch (feat_num) {
>        case DCCPF_CCID:
> -               return val == DCCPC_CCID2 || val == DCCPC_CCID3;
> +               return  val == DCCPC_CCID2 || val == DCCPC_CCID3 ||
> +                       (val >= DCCPC_TESTING_MIN && val <= DCCPC_TESTING_MAX);
>        /* Type-check Boolean feature values: */
>        case DCCPF_SHORT_SEQNOS:
>        case DCCPF_ECN_INCAPABLE:
> @@ -831,6 +832,18 @@ EXPORT_SYMBOL_GPL(dccp_feat_signal_nn_ch
>  */
>  static const struct ccid_dependency *dccp_feat_ccid_deps(u8 ccid, bool is_local)
>  {
> +       static const struct ccid_dependency ccid0_dependencies[2][2] = {
> +               /*
> +                * The UDP-like CCID does not have special dependencies, but for
> +                * testing dependencies (e.g. Ack Vectors) can be defined below.
> +                */
> +               {
> +                       { 0, 0, 0, 0 }
> +               },
> +               {
> +                       { 0, 0, 0, 0 }
> +               }
> +       };
>        static const struct ccid_dependency ccid2_dependencies[2][2] = {
>                /*
>                 * CCID2 mandates Ack Vectors (RFC 4341, 4.): as CCID is a TX
> @@ -916,6 +929,8 @@ static const struct ccid_dependency *dcc
>                }
>        };
>        switch (ccid) {
> +       case DCCPC_CCID_ZERO:
> +               return ccid0_dependencies[is_local];
>        case DCCPC_CCID2:
>                return ccid2_dependencies[is_local];
>        case DCCPC_CCID3:
> --- a/net/dccp/ccids/Kconfig
> +++ b/net/dccp/ccids/Kconfig
> @@ -103,4 +103,16 @@ config IP_DCCP_TFRC_LIB
>
>  config IP_DCCP_TFRC_DEBUG
>        def_bool y if IP_DCCP_CCID3_DEBUG
> +
> +config IP_DCCP_CCID0
> +       bool "CCID-ZERO (UDP-Like) sample kernel module"
> +       def_bool n
> +       ---help---
> +         This is a sample kernel module to illustrate the integration of new
> +         CCID kernel modules into CCID. It can also be used for performance
> +         testing, but is not meant for deployment since it operates without
> +         any congestion control. It is a NULL CCID, its identifier is 248.
> +
> +         Say N.
> +
>  endmenu
> --- a/net/dccp/Makefile
> +++ b/net/dccp/Makefile
> @@ -7,6 +7,7 @@ dccp-y := ccid.o feat.o input.o minisock
>  #
>  # CCID-2 is default (RFC 4340, p. 77) and has Ack Vectors as dependency
>  dccp-y += ccids/ccid2.o ackvec.o
> +dccp-$(CONFIG_IP_DCCP_CCID0)   += ccids/ccid0.o
>  dccp-$(CONFIG_IP_DCCP_CCID3)   += ccids/ccid3.o
>  dccp-$(CONFIG_IP_DCCP_TFRC_LIB) += ccids/lib/tfrc.o            \
>                                   ccids/lib/tfrc_equation.o    \
> --
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Acked-by: Ivo Calado <ivocalado@embedded.ufcg.edu.br>  for ccid4 subtree