linux-toradex.git/net/dccp/feat.h, branch v5.4

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

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 
Reviewed-by: Enrico Weigelt 
Reviewed-by: Kate Stewart 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman

net: dccp: Remove extern from function prototypes

2013-10-19T23:12:11+00:00

There are a mix of function prototypes with and without extern
in the kernel sources.  Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler.  Its use is as unnecessary as
using auto to declare automatic/local variables in a block.

Signed-off-by: Joe Perches 
Signed-off-by: David S. Miller

dccp: support for the exchange of NN options in established state 1/2

2011-08-01T13:52:34+00:00

In contrast to static feature negotiation at the begin of a connection, this
patch introduces support for exchange of dynamically changing options.

Such an update/exchange is necessary in at least two cases:
 * CCID-2's Ack Ratio (RFC 4341, 6.1.2) which changes during the connection;
 * Sequence Window values that, as per RFC 4340, 7.5.2, should be sent "as
   the connection progresses".

Both are non-negotiable (NN) features, which means that no new capabilities
are negotiated, but rather that changes in known parameters are brought
up-to-date at either end.

Thse characteristics are reflected by the implementation:
 * only NN options can be exchanged after connection setup;
 * an ack is scheduled directly after activation to speed up the update;
 * CCIDs may request changes to an NN feature even if a negotiation for that
   feature is already underway: this is required by CCID-2, where changes in
   cwnd necessitate Ack Ratio changes, such that the previous Ack Ratio (which
   is still being negotiated) would cause irrecoverable RTO timeouts (thanks
   to work by Samuel Jero).	   

Signed-off-by: Gerrit Renker 
Signed-off-by: Samuel Jero 
Acked-by: Ian McDonald

dccp: Kill dead code and add static markers.

2010-10-07T06:12:07+00:00

Remove dead code and make some functions static.
Compile tested only.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

dccp: Debugging functions for feature negotiation

2009-01-21T22:34:05+00:00

Since all feature-negotiation processing now takes place in feat.c,
functions for producing verbose debugging output are concentrated
there.

New functions to print out values, entry records, and options are
provided, and also a macro is defined to not always have the function
name in the output line.

Thanks a lot to Wei Yongjun and Giuseppe Galeota for help and
discussion with an earlier revision of this patch.

Signed-off-by: Gerrit Renker 
Acked-by: Ian McDonald 
Signed-off-by: David S. Miller

dccp: Initialisation and type-checking of feature sysctls

2009-01-21T22:34:05+00:00

This patch takes care of initialising and type-checking sysctls
related to feature negotiation. Type checking is important since some
of the sysctls now directly impact the feature-negotiation process.

The sysctls are initialised with the known default values for each
feature.  For the type-checking the value constraints from RFC 4340
are used:

 * Sequence Window uses the specified Wmin=32, the maximum is ulong (4 bytes),
   tested and confirmed that it works up to 4294967295 - for Gbps speed;
 * Ack Ratio is between 0 .. 0xffff (2-byte unsigned integer);
 * CCIDs are between 0 .. 255;
 * request_retries, retries1, retries2 also between 0..255 for good measure;
 * tx_qlen is checked to be non-negative;
 * sync_ratelimit remains as before.

Notes:
------
 1. Die s@sysctl_dccp_feat@sysctl_dccp@g since the sysctls are now in feat.c.
 2. As pointed out by Arnaldo, the pattern of type-checking repeats itself in
    other places, sometimes with exactly the same kind of definitions (e.g.
    "static int zero;"). It may be a good idea (kernel janitors?) to consolidate
    type checking. For the sake of keeping the changeset small and in order not
    to affect other subsystems, I have not strived to generalise here.

Signed-off-by: Gerrit Renker 
Acked-by: Ian McDonald 
Signed-off-by: David S. Miller

dccp: Initialisation framework for feature negotiation

2009-01-21T22:34:04+00:00

This initialises feature negotiation from two tables, which are in
turn are initialised from sysctls.

As a novel feature, specifics of the implementation (e.g. that short
seqnos and ECN are not yet available) are advertised for robustness.

Signed-off-by: Gerrit Renker 
Acked-by: Ian McDonald 
Signed-off-by: David S. Miller

dccp: Clean up old feature-negotiation infrastructure

2008-12-08T09:17:32+00:00

The code removed by this patch is no longer referenced or used, the added
lines update documentation and copyrights.

Signed-off-by: Gerrit Renker 
Acked-by: Ian McDonald 
Signed-off-by: David S. Miller

dccp: Processing Confirm options

2008-12-02T07:33:18+00:00

Analogous to the previous patch, this adds code to interpret incoming Confirm
feature-negotiation options. Both functions operate on the feature-negotiation
list of either the request_sock (server) or the dccp_sock (client).

Thanks to Wei Yongjun for pointing out that it is overly restrictive to check
the entire list of confirmed SP values.

Signed-off-by: Gerrit Renker 
Acked-by: Ian McDonald 
Signed-off-by: David S. Miller

dccp: Process incoming Change feature-negotiation options

2008-12-02T07:32:35+00:00

This adds/replaces code for processing incoming ChangeL/R options.
The main difference is that:
 * mandatory FN options are now interpreted inside the function
  (there are too many individual cases to do this externally);
 * the function returns an appropriate Reset code or 0,
   which is then used to fill in the data for the Reset packet.

Old code, which is no longer used or referenced, has been removed.

Signed-off-by: Gerrit Renker 
Signed-off-by: David S. Miller