History log of /linux/net/dccp/ackvec.h (Results 1 – 25 of 38)
Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
Revision tags: v5.18-rc5, v5.18-rc4, v5.18-rc3, v5.18-rc2, v5.18-rc1, v5.17, v5.17-rc8, v5.17-rc7, v5.17-rc6, v5.17-rc5, v5.17-rc4, v5.17-rc3, v5.17-rc2, v5.17-rc1, v5.16, v5.16-rc8, v5.16-rc7, v5.16-rc6, v5.16-rc5, v5.16-rc4, v5.16-rc3, v5.16-rc2, v5.16-rc1, v5.15, v5.15-rc7, v5.15-rc6, v5.15-rc5, v5.15-rc4, v5.15-rc3, v5.15-rc2, v5.15-rc1, v5.14, v5.14-rc7, v5.14-rc6, v5.14-rc5, v5.14-rc4, v5.14-rc3, v5.14-rc2, v5.14-rc1, v5.13, v5.13-rc7, v5.13-rc6, v5.13-rc5, v5.13-rc4, v5.13-rc3, v5.13-rc2, v5.13-rc1, v5.12, v5.12-rc8, v5.12-rc7, v5.12-rc6, v5.12-rc5, v5.12-rc4, v5.12-rc3, v5.12-rc2, v5.12-rc1-dontuse, v5.11, v5.11-rc7, v5.11-rc6, v5.11-rc5, v5.11-rc4, v5.11-rc3, v5.11-rc2, v5.11-rc1, v5.10, v5.10-rc7, v5.10-rc6, v5.10-rc5, v5.10-rc4, v5.10-rc3, v5.10-rc2, v5.10-rc1, v5.9, v5.9-rc8, v5.9-rc7, v5.9-rc6, v5.9-rc5, v5.9-rc4, v5.9-rc3, v5.9-rc2, v5.9-rc1, v5.8, v5.8-rc7, v5.8-rc6, v5.8-rc5, v5.8-rc4, v5.8-rc3, v5.8-rc2, v5.8-rc1, v5.7, v5.7-rc7, v5.7-rc6, v5.7-rc5, v5.7-rc4, v5.7-rc3, v5.7-rc2, v5.7-rc1, v5.6, v5.6-rc7, v5.6-rc6, v5.6-rc5, v5.6-rc4, v5.6-rc3, v5.6-rc2, v5.6-rc1, v5.5, v5.5-rc7, v5.5-rc6, v5.5-rc5, v5.5-rc4, v5.5-rc3, v5.5-rc2, v5.5-rc1, v5.4, v5.4-rc8, v5.4-rc7, v5.4-rc6, v5.4-rc5, v5.4-rc4, v5.4-rc3, v5.4-rc2, v5.4-rc1, v5.3, v5.3-rc8, v5.3-rc7, v5.3-rc6, v5.3-rc5, v5.3-rc4, v5.3-rc3, v5.3-rc2, v5.3-rc1, v5.2, v5.2-rc7, v5.2-rc6, v5.2-rc5, v5.2-rc4
# d2912cb1 04-Jun-2019 Thomas Gleixner <tglx@linutronix.de>

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 th

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>

show more ...


Revision tags: v5.2-rc3, v5.2-rc2, v5.2-rc1, v5.1, v5.1-rc7, v5.1-rc6, v5.1-rc5, v5.1-rc4, v5.1-rc3, v5.1-rc2, v5.1-rc1, v5.0, v5.0-rc8, v5.0-rc7, v5.0-rc6, v5.0-rc5, v5.0-rc4, v5.0-rc3, v5.0-rc2, v5.0-rc1, v4.20, v4.20-rc7, v4.20-rc6, v4.20-rc5, v4.20-rc4, v4.20-rc3, v4.20-rc2, v4.20-rc1, v4.19, v4.19-rc8, v4.19-rc7, v4.19-rc6, v4.19-rc5, v4.19-rc4, v4.19-rc3, v4.19-rc2, v4.19-rc1, v4.18, v4.18-rc8, v4.18-rc7, v4.18-rc6, v4.18-rc5, v4.18-rc4, v4.18-rc3, v4.18-rc2, v4.18-rc1, v4.17, v4.17-rc7, v4.17-rc6, v4.17-rc5, v4.17-rc4, v4.17-rc3, v4.17-rc2, v4.17-rc1, v4.16, v4.16-rc7, v4.16-rc6, v4.16-rc5, v4.16-rc4, v4.16-rc3, v4.16-rc2, v4.16-rc1, v4.15, v4.15-rc9, v4.15-rc8, v4.15-rc7, v4.15-rc6, v4.15-rc5, v4.15-rc4, v4.15-rc3, v4.15-rc2, v4.15-rc1, v4.14, v4.14-rc8, v4.14-rc7, v4.14-rc6, v4.14-rc5, v4.14-rc4, v4.14-rc3, v4.14-rc2, v4.14-rc1, v4.13, v4.13-rc7, v4.13-rc6, v4.13-rc5, v4.13-rc4, v4.13-rc3, v4.13-rc2, v4.13-rc1, v4.12, v4.12-rc7, v4.12-rc6, v4.12-rc5, v4.12-rc4, v4.12-rc3, v4.12-rc2, v4.12-rc1, v4.11, v4.11-rc8, v4.11-rc7, v4.11-rc6, v4.11-rc5, v4.11-rc4, v4.11-rc3, v4.11-rc2, v4.11-rc1, v4.10, v4.10-rc8, v4.10-rc7, v4.10-rc6, v4.10-rc5, v4.10-rc4, v4.10-rc3, v4.10-rc2, v4.10-rc1, v4.9, v4.9-rc8, v4.9-rc7, v4.9-rc6, v4.9-rc5, v4.9-rc4, v4.9-rc3, v4.9-rc2, v4.9-rc1, v4.8, v4.8-rc8, v4.8-rc7, v4.8-rc6, v4.8-rc5, v4.8-rc4, v4.8-rc3, v4.8-rc2, v4.8-rc1, v4.7, v4.7-rc7, v4.7-rc6, v4.7-rc5, v4.7-rc4, v4.7-rc3, v4.7-rc2, v4.7-rc1, v4.6, v4.6-rc7, v4.6-rc6, v4.6-rc5, v4.6-rc4, v4.6-rc3, v4.6-rc2, v4.6-rc1, v4.5, v4.5-rc7, v4.5-rc6, v4.5-rc5, v4.5-rc4, v4.5-rc3, v4.5-rc2, v4.5-rc1, v4.4, v4.4-rc8, v4.4-rc7, v4.4-rc6, v4.4-rc5, v4.4-rc4, v4.4-rc3, v4.4-rc2, v4.4-rc1, v4.3, v4.3-rc7, v4.3-rc6, v4.3-rc5, v4.3-rc4, v4.3-rc3, v4.3-rc2, v4.3-rc1, v4.2, v4.2-rc8, v4.2-rc7, v4.2-rc6, v4.2-rc5, v4.2-rc4, v4.2-rc3, v4.2-rc2, v4.2-rc1, v4.1, v4.1-rc8, v4.1-rc7, v4.1-rc6, v4.1-rc5, v4.1-rc4, v4.1-rc3, v4.1-rc2, v4.1-rc1, v4.0, v4.0-rc7, v4.0-rc6, v4.0-rc5, v4.0-rc4, v4.0-rc3, v4.0-rc2, v4.0-rc1, v3.19, v3.19-rc7, v3.19-rc6, v3.19-rc5, v3.19-rc4, v3.19-rc3, v3.19-rc2, v3.19-rc1, v3.18, v3.18-rc7, v3.18-rc6, v3.18-rc5, v3.18-rc4, v3.18-rc3, v3.18-rc2, v3.18-rc1, v3.17, v3.17-rc7, v3.17-rc6, v3.17-rc5, v3.17-rc4, v3.17-rc3, v3.17-rc2, v3.17-rc1, v3.16, v3.16-rc7, v3.16-rc6, v3.16-rc5, v3.16-rc4, v3.16-rc3, v3.16-rc2, v3.16-rc1, v3.15, v3.15-rc8, v3.15-rc7, v3.15-rc6, v3.15-rc5, v3.15-rc4, v3.15-rc3, v3.15-rc2, v3.15-rc1, v3.14, v3.14-rc8, v3.14-rc7, v3.14-rc6, v3.14-rc5, v3.14-rc4, v3.14-rc3, v3.14-rc2, v3.14-rc1, v3.13, v3.13-rc8, v3.13-rc7, v3.13-rc6, v3.13-rc5, v3.13-rc4, v3.13-rc3, v3.13-rc2, v3.13-rc1, v3.12, v3.12-rc7, v3.12-rc6
# a402a5aa 18-Oct-2013 Joe Perches <joe@perches.com>

net: dccp: Remove extern from function prototypes

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

Fun

net: dccp: Remove extern from function prototypes

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 <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...


Revision tags: v3.12-rc5, v3.12-rc4, v3.12-rc3, v3.12-rc2, v3.12-rc1, v3.11, v3.11-rc7, v3.11-rc6, v3.11-rc5, v3.11-rc4, v3.11-rc3, v3.11-rc2, v3.11-rc1, v3.10, v3.10-rc7, v3.10-rc6, v3.10-rc5, v3.10-rc4, v3.10-rc3, v3.10-rc2, v3.10-rc1, v3.9, v3.9-rc8, v3.9-rc7, v3.9-rc6, v3.9-rc5, v3.9-rc4, v3.9-rc3, v3.9-rc2, v3.9-rc1, v3.8, v3.8-rc7, v3.8-rc6, v3.8-rc5, v3.8-rc4, v3.8-rc3, v3.8-rc2, v3.8-rc1, v3.7, v3.7-rc8, v3.7-rc7, v3.7-rc6, v3.7-rc5, v3.7-rc4, v3.7-rc3, v3.7-rc2, v3.7-rc1, v3.6, v3.6-rc7, v3.6-rc6, v3.6-rc5, v3.6-rc4, v3.6-rc3, v3.6-rc2, v3.6-rc1, v3.5, v3.5-rc7
# 2c53040f 10-Jul-2012 Ben Hutchings <bhutchings@solarflare.com>

net: Fix (nearly-)kernel-doc comments for various functions

Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.

Signed-off-by

net: Fix (nearly-)kernel-doc comments for various functions

Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...


Revision tags: v3.5-rc6, v3.5-rc5, v3.5-rc4, v3.5-rc3, v3.5-rc2, v3.5-rc1, v3.4, v3.4-rc7, v3.4-rc6, v3.4-rc5, v3.4-rc4, v3.4-rc3, v3.4-rc2, v3.4-rc1, v3.3, v3.3-rc7, v3.3-rc6, v3.3-rc5, v3.3-rc4, v3.3-rc3, v3.3-rc2, v3.3-rc1, v3.2, v3.2-rc7, v3.2-rc6, v3.2-rc5, v3.2-rc4, v3.2-rc3, v3.2-rc2, v3.2-rc1, v3.1, v3.1-rc10, v3.1-rc9, v3.1-rc8, v3.1-rc7, v3.1-rc6, v3.1-rc5, v3.1-rc4, v3.1-rc3, v3.1-rc2, v3.1-rc1, v3.0, v3.0-rc7, v3.0-rc6, v3.0-rc5, v3.0-rc4, v3.0-rc3, v3.0-rc2, v3.0-rc1, v2.6.39, v2.6.39-rc7, v2.6.39-rc6, v2.6.39-rc5, v2.6.39-rc4, v2.6.39-rc3, v2.6.39-rc2, v2.6.39-rc1, v2.6.38, v2.6.38-rc8, v2.6.38-rc7, v2.6.38-rc6, v2.6.38-rc5, v2.6.38-rc4, v2.6.38-rc3, v2.6.38-rc2, v2.6.38-rc1, v2.6.37, v2.6.37-rc8, v2.6.37-rc7, v2.6.37-rc6, v2.6.37-rc5, v2.6.37-rc4, v2.6.37-rc3, v2.6.37-rc2
# 7e87fe84 14-Nov-2010 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Separate option parsing from CCID processing

This patch replaces an almost identical replication of code: large parts
of dccp_parse_options() re-appeared as ccid2_ackvector() in ccid2.c

dccp ccid-2: Separate option parsing from CCID processing

This patch replaces an almost identical replication of code: large parts
of dccp_parse_options() re-appeared as ccid2_ackvector() in ccid2.c.

Apart from the duplication, this caused two more problems:
1. CCIDs should not need to be concerned with parsing header options;
2. one can not assume that Ack Vectors appear as a contiguous area within an
skb, it is legal to insert other options and/or padding in between. The
current code would throw an error and stop reading in such a case.

Since Ack Vectors provide CCID-specific information, they are now processed
by the CCID directly, separating this functionality from the main DCCP code.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

show more ...


# 52394eec 14-Nov-2010 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Remove old infrastructure

This removes
* functions for which updates have been provided in the preceding patches and
* the @av_vec_len field - it is no longer necessary since the buff

dccp ccid-2: Remove old infrastructure

This removes
* functions for which updates have been provided in the preceding patches and
* the @av_vec_len field - it is no longer necessary since the buffer length is
now always computed dynamically.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

show more ...


# 38024086 14-Nov-2010 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Update code for the Ack Vector input/registration routine

This patch updates the code which registers new packets as received, using the
new circular buffer interface. It contributes a

dccp ccid-2: Update code for the Ack Vector input/registration routine

This patch updates the code which registers new packets as received, using the
new circular buffer interface. It contributes a new algorithm which
* supports both tail/head pointers and buffer wrap-around and
* deals with overflow (head/tail move in lock-step).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

show more ...


# 5753fdfe 14-Nov-2010 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Algorithm to update buffer state

This provides a routine to consistently update the buffer state when the
peer acknowledges receipt of Ack Vectors; updating state in the list of Ack
Vec

dccp ccid-2: Algorithm to update buffer state

This provides a routine to consistently update the buffer state when the
peer acknowledges receipt of Ack Vectors; updating state in the list of Ack
Vectors as well as in the circular buffer.

While based on RFC 4340, several additional (and necessary) precautions were
added to protect the consistency of the buffer state. These additions are
essential, since analysis and experience showed that the basic algorithm was
insufficient for this task (which lead to problems that were hard to debug).

The algorithm now
* deals with HC-sender acknowledging to HC-receiver and vice versa,
* keeps track of the last unacknowledged but received seqno in tail_ackno,
* has special cases to reset the overflow condition when appropriate,
* is protected against receiving older information (would mess up buffer state).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

show more ...


# b3d14bff 10-Nov-2010 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Implementation of circular Ack Vector buffer with overflow handling

This completes the implementation of a circular buffer for Ack Vectors, by
extending the current (linear array-based)

dccp ccid-2: Implementation of circular Ack Vector buffer with overflow handling

This completes the implementation of a circular buffer for Ack Vectors, by
extending the current (linear array-based) implementation. The changes are:

(a) An `overflow' flag to deal with the case of overflow. As before, dynamic
growth of the buffer will not be supported; but code will be added to deal
robustly with overflowing Ack Vector buffers.

(b) A `tail_seqno' field. When naively implementing the algorithm of Appendix A
in RFC 4340, problems arise whenever subsequent Ack Vector records overlap,
which can bring the entire run length calculation completely out of synch.
(This is documented on http://www.erg.abdn.ac.uk/users/gerrit/dccp/notes/\
ack_vectors/tracking_tail_ackno/ .)
(c) The buffer length is now computed dynamically (i.e. current fill level),
as the span between head to tail.

As a result, dccp_ackvec_pending() is now simpler - the #ifdef is no longer
necessary since buf_empty is always true when IP_DCCP_ACKVEC is not configured.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

show more ...


# 7d870936 10-Nov-2010 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Separate internals of Ack Vectors from option-parsing code

This patch
* separates Ack Vector housekeeping code from option-insertion code;
* shifts option-specific code from ackvec.c

dccp ccid-2: Separate internals of Ack Vectors from option-parsing code

This patch
* separates Ack Vector housekeeping code from option-insertion code;
* shifts option-specific code from ackvec.c into options.c;
* introduces a dedicated routine to take care of the Ack Vector records;
* simplifies the dccp_ackvec_insert_avr() routine: the BUG_ON was redundant,
since the list is automatically arranged in descending order of ack_seqno.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

show more ...


# f17a37c9 10-Nov-2010 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Ack Vector interface clean-up

This patch brings the Ack Vector interface up to date. Its main purpose is
to lay the basis for the subsequent patches of this set, which will use the
new

dccp ccid-2: Ack Vector interface clean-up

This patch brings the Ack Vector interface up to date. Its main purpose is
to lay the basis for the subsequent patches of this set, which will use the
new data structure fields and routines.

There are no real algorithmic changes, rather an adaptation:

(1) Replaced the static Ack Vector size (2) with a #define so that it can
be adapted (with low loss / Ack Ratio, a value of 1 works, so 2 seems
to be sufficient for the moment) and added a solution so that computing
the ECN nonce will continue to work - even with larger Ack Vectors.

(2) Replaced the #defines for Ack Vector states with a complete enum.

(3) Replaced #defines to compute Ack Vector length and state with general
purpose routines (inlines), and updated code to use these.

(4) Added a `tail' field (conversion to circular buffer in subsequent patch).

(5) Updated the (outdated) documentation for Ack Vector struct.

(6) All sequence number containers now trimmed to 48 bits.

(7) Removal of unused bits:
* removed dccpav_ack_nonce from struct dccp_ackvec, since this is already
redundantly stored in the `dccpavr_ack_nonce' (of Ack Vector record);
* removed Elapsed Time for Ack Vectors (it was nowhere used);
* replaced semantics of dccpavr_sent_len with dccpavr_ack_runlen, since
the code needs to be able to remember the old run length;
* reduced the de-/allocation routines (redundant / duplicate tests).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

show more ...


Revision tags: v2.6.37-rc1, v2.6.36, v2.6.36-rc8, v2.6.36-rc7, v2.6.36-rc6, v2.6.36-rc5, v2.6.36-rc4, v2.6.36-rc3, v2.6.36-rc2, v2.6.36-rc1, v2.6.35, v2.6.35-rc6, v2.6.35-rc5, v2.6.35-rc4, v2.6.35-rc3, v2.6.35-rc2, v2.6.35-rc1, v2.6.34, v2.6.34-rc7, v2.6.34-rc6, v2.6.34-rc5, v2.6.34-rc4, v2.6.34-rc3, v2.6.34-rc2, v2.6.34-rc1, v2.6.33, v2.6.33-rc8, v2.6.33-rc7, v2.6.33-rc6, v2.6.33-rc5, v2.6.33-rc4, v2.6.33-rc3, v2.6.33-rc2, v2.6.33-rc1, v2.6.32, v2.6.32-rc8, v2.6.32-rc7, v2.6.32-rc6, v2.6.32-rc5, v2.6.32-rc4, v2.6.32-rc3, v2.6.32-rc1, v2.6.32-rc2, v2.6.31, v2.6.31-rc9, v2.6.31-rc8, v2.6.31-rc7, v2.6.31-rc6, v2.6.31-rc5, v2.6.31-rc4, v2.6.31-rc3, v2.6.31-rc2, v2.6.31-rc1, v2.6.30, v2.6.30-rc8, v2.6.30-rc7, v2.6.30-rc6, v2.6.30-rc5, v2.6.30-rc4, v2.6.30-rc3, v2.6.30-rc2, v2.6.30-rc1, v2.6.29, v2.6.29-rc8, v2.6.29-rc7
# 361a5c1d 27-Feb-2009 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp: Minimise header option overhead in setting the MPS

This patch resolves a long-standing FIXME to dynamically update the Maximum
Packet Size depending on actual options usage.

It uses the flags

dccp: Minimise header option overhead in setting the MPS

This patch resolves a long-standing FIXME to dynamically update the Maximum
Packet Size depending on actual options usage.

It uses the flags set by the feature-negotiation infrastructure to compute
the required header option size.

Most options are fixed-size, a notable exception are Ack Vectors (required
currently only by CCID-2). These can have any length between 3 and 1020
bytes. As a result of testing, 16 bytes (2 bytes for type/length plus 14 Ack
Vector cells) have been found to be sufficient for loss-free situations.

There are currently no CCID-specific header options which may appear on data
packets, thus it is not necessary to define a corresponding CCID field as
suggested in the old comment.

Further changes:
----------------
Adjusted the type of 'cur_mps' to match the unsigned return type of the
function.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>

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Revision tags: v2.6.29-rc6, v2.6.29-rc5, v2.6.29-rc4, v2.6.29-rc3, v2.6.29-rc2, v2.6.29-rc1
# e5fd56ca 05-Jan-2009 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp: Clean up ccid.c after integration of CCID plugins

This patch cleans up after integrating the CCID modules and, in addition,

* moves the if/else cases from ccid_delete() into ccid_hc_{tx,rx}_

dccp: Clean up ccid.c after integration of CCID plugins

This patch cleans up after integrating the CCID modules and, in addition,

* moves the if/else cases from ccid_delete() into ccid_hc_{tx,rx}_delete();
* removes the 'gfp' argument to ccid_new() - since it is always gfp_any().

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

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# ddebc973 05-Jan-2009 Gerrit Renker <gerrit@erg.abdn.ac.uk>

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 wit

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>

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Revision tags: v2.6.28, v2.6.28-rc9, v2.6.28-rc8, v2.6.28-rc7
# b20a9c24 24-Nov-2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp: Set per-connection CCIDs via socket options

With this patch, TX/RX CCIDs can now be changed on a per-connection
basis, which overrides the defaults set by the global sysctl variables
for TX/RX

dccp: Set per-connection CCIDs via socket options

With this patch, TX/RX CCIDs can now be changed on a per-connection
basis, which overrides the defaults set by the global sysctl variables
for TX/RX CCIDs.

To make full use of this facility, the remaining patches of this patch
set are needed, which track dependencies and activate negotiated
feature values.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

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Revision tags: v2.6.28-rc6, v2.6.28-rc5, v2.6.28-rc4, v2.6.28-rc3, v2.6.28-rc2, v2.6.28-rc1, v2.6.27, v2.6.27-rc9, v2.6.27-rc8, v2.6.27-rc7, v2.6.27-rc6
# 410e27a4 09-Sep-2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>

This reverts "Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/dccp_exp"
as it accentally contained the wrong set of patches. These will be
submitted separately.
Signed-off-by: Gerrit Renker <ge

This reverts "Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/dccp_exp"
as it accentally contained the wrong set of patches. These will be
submitted separately.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

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# c8bf462b 04-Sep-2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Separate option parsing from CCID processing

This patch replaces an almost identical replication of code: large parts
of dccp_parse_options() re-appeared as ccid2_ackvector() in ccid2.c

dccp ccid-2: Separate option parsing from CCID processing

This patch replaces an almost identical replication of code: large parts
of dccp_parse_options() re-appeared as ccid2_ackvector() in ccid2.c.

Apart from the duplication, this caused two more problems:
1. CCIDs should not need to be concerned with parsing header options;
2. one can not assume that Ack Vectors appear as a contiguous area within an
skb, it is legal to insert other options and/or padding in between. The
current code would throw an error and stop reading in such a case.

The patch provides a new data structure and associated list housekeeping.

Only small changes were necessary to integrate with CCID-2: data structure
initialisation, adapt list traversal routine, and add call to the provided
cleanup routine.

The latter also lead to fixing the following BUG: CCID-2 so far ignored
Ack Vectors on all packets other than Ack/DataAck, which is incorrect,
since Ack Vectors can be present on any packet that has an Ack field.

Details:
--------
* received Ack Vectors are parsed by dccp_parse_options() alone, which passes
the result on to the CCID-specific routine ccid_hc_tx_parse_options();
* CCIDs interested in using/decoding Ack Vector information will add code
to fetch parsed Ack Vectors via this interface;
* a data structure, `struct dccp_ackvec_parsed' is provided as interface;
* this structure arranges Ack Vectors of the same skb into a FIFO order;
* a doubly-linked list is used to keep the required FIFO code small.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

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# 5a577b48 04-Sep-2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Remove old infrastructure

This removes
* functions for which updates have been provided in the preceding patches and
* the @av_vec_len field - it is no longer necessary since the buff

dccp ccid-2: Remove old infrastructure

This removes
* functions for which updates have been provided in the preceding patches and
* the @av_vec_len field - it is no longer necessary since the buffer length is
now always computed dynamically;
* conditional debugging code (CONFIG_IP_DCCP_ACKVEC).

The reason for removing the conditional debugging code is that Ack Vectors are
an almost inevitable necessity - RFC 4341 says that for CCID-2, Ack Vectors must
be used. Furthermore, the code would be only interesting for coding - after some
extensive testing with this patch set, having the debug code around is no longer
of real help.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

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# e28fe59f 04-Sep-2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Update code for the Ack Vector input/registration routine

This patch uupdates the code which registers new packets as received, using the
new circular buffer interface. It contributes a

dccp ccid-2: Update code for the Ack Vector input/registration routine

This patch uupdates the code which registers new packets as received, using the
new circular buffer interface. It contributes a new algorithm which
* supports both tail/head pointers and buffer wrap-around and
* deals with overflow (head/tail move in lock-step).

The updated code is also partioned differently, into
1. dealing with the empty buffer,
2. adding new packets into non-empty buffer,
3. reserving space when encountering a `hole' in the sequence space,
4. updating old state and deciding when old state is irrelevant.

Protection against large burst losses: With regard to (3), it is too costly to
reserve space when there are large bursts of losses. When bursts get too large,
the code does no longer reserve space and just fills in cells normally. This
measure reduces space consumption by a factor of 63.

The code reuses in part the previous implementation by Arnaldo de Melo.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

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# 68b1de15 04-Sep-2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Algorithm to update buffer state

This provides a routine to consistently update the buffer state when the
peer acknowledges receipt of Ack Vectors; updating state in the list of Ack
Vec

dccp ccid-2: Algorithm to update buffer state

This provides a routine to consistently update the buffer state when the
peer acknowledges receipt of Ack Vectors; updating state in the list of Ack
Vectors as well as in the circular buffer.

While based on RFC 4340, several additional (and necessary) precautions were
added to protect the consistency of the buffer state. These additions are
essential, since analysis and experience showed that the basic algorithm was
insufficient for this task (which lead to problems that were hard to debug).

The algorithm now
* deals with HC-sender acknowledging to HC-receiver and vice versa,
* keeps track of the last unacknowledged but received seqno in tail_ackno,
* has special cases to reset the overflow condition when appropriate,
* is protected against receiving older information (would mess up buffer state).

Note: The older code performed an unnecessary step, where the sender cleared
Ack Vector state by parsing the Ack Vector received by the HC-receiver. Doing
this was entirely redundant, since
* the receiver always puts the full acknowledgment window (groups 2,3 in 11.4.2)
into the Ack Vectors it sends; hence the HC-receiver is only interested in the
highest state that the HC-sender received;
* this means that the acknowledgment number on the (Data)Ack from the HC-sender
is sufficient; and work done in parsing earlier state is not necessary, since
the later state subsumes the earlier one (see also RFC 4340, A.4).
This older interface (dccp_ackvec_parse()) is therefore removed.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

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# d7dc7e5f 04-Sep-2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Implementation of circular Ack Vector buffer with overflow handling

This completes the implementation of a circular buffer for Ack Vectors, by
extending the current (linear array-based

dccp ccid-2: Implementation of circular Ack Vector buffer with overflow handling

This completes the implementation of a circular buffer for Ack Vectors, by
extending the current (linear array-based) implementation. The changes are:

(a) An `overflow' flag to deal with the case of overflow. As before, dynamic
growth of the buffer will not be supported; but code will be added to deal
robustly with overflowing Ack Vector buffers.

(b) A `tail_seqno' field. When naively implementing the algorithm of Appendix A
in RFC 4340, problems arise whenever subsequent Ack Vector records overlap,
which can bring the entire run length calculation completely out of synch.
(This is documented on http://www.erg.abdn.ac.uk/users/gerrit/dccp/notes/\
ack_vectors/tracking_tail_ackno/ .)
(c) The buffer lengthi is now computed dynamically (i.e. current fill level),
as the span between head to tail.

As a result, dccp_ackvec_pending() is now simpler - the #ifdef is no longer
necessary since buf_empty is always true when IP_DCCP_ACKVEC is not configured.

Note on overflow handling:
-------------------------
The Ack Vector code previously simply started to drop packets when the
Ack Vector buffer overflowed. This means that the userspace application
will not be able to receive, only because of an Ack Vector storage problem.

Furthermore, overflow may be transient, so that applications may later
recover from the overflow. Recovering from dropped packets is more difficult
(e.g. video key frames).

Hence the patch uses a different policy: when the buffer overflows, the oldest
entries are subsequently overwritten. This has a higher chance of recovery.
Details are on http://www.erg.abdn.ac.uk/users/gerrit/dccp/notes/ack_vectors/

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

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# 4829007c 04-Sep-2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Separate internals of Ack Vectors from option-parsing code

This patch
* separates Ack Vector housekeeping code from option-insertion code;
* shifts option-specific code from ackvec.c

dccp ccid-2: Separate internals of Ack Vectors from option-parsing code

This patch
* separates Ack Vector housekeeping code from option-insertion code;
* shifts option-specific code from ackvec.c into options.c;
* introduces a dedicated routine to take care of the Ack Vector records;
* simplifies the dccp_ackvec_insert_avr() routine: the BUG_ON was redundant,
since the list is automatically arranged in descending order of ack_seqno.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

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# ff49e270 04-Sep-2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp ccid-2: Ack Vector interface clean-up

This patch brings the Ack Vector interface up to date. Its main purpose is
to lay the basis for the subsequent patches of this set, which will use the
new

dccp ccid-2: Ack Vector interface clean-up

This patch brings the Ack Vector interface up to date. Its main purpose is
to lay the basis for the subsequent patches of this set, which will use the
new data structure fields and routines.

There are no real algorithmic changes, rather an adaptation:

(1) Replaced the static Ack Vector size (2) with a #define so that it can
be adapted (with low loss / Ack Ratio, a value of 1 works, so 2 seems
to be sufficient for the moment) and added a solution so that computing
the ECN nonce will continue to work - even with larger Ack Vectors.

(2) Replaced the #defines for Ack Vector states with a complete enum.

(3) Replaced #defines to compute Ack Vector length and state with general
purpose routines (inlines), and updated code to use these.

(4) Added a `tail' field (conversion to circular buffer in subsequent patch).

(5) Updated the (outdated) documentation for Ack Vector struct.

(6) All sequence number containers now trimmed to 48 bits.

(7) Removal of unused bits:
* removed dccpav_ack_nonce from struct dccp_ackvec, since this is already
redundantly stored in the `dccpavr_ack_nonce' (of Ack Vector record);
* removed Elapsed Time for Ack Vectors (it was nowhere used);
* replaced semantics of dccpavr_sent_len with dccpavr_ack_runlen, since
the code needs to be able to remember the old run length;
* reduced the de-/allocation routines (redundant / duplicate tests).


Justification for removing Elapsed Time information [can be removed]:
---------------------------------------------------------------------
1. The Elapsed Time information for Ack Vectors was nowhere used in the code.
2. DCCP does not implement rate-based pacing of acknowledgments. The only
recommendation for always including Elapsed Time is in section 11.3 of
RFC 4340: "Receivers that rate-pace acknowledgements SHOULD [...]
include Elapsed Time options". But such is not the case here.
3. It does not really improve estimation accuracy. The Elapsed Time field only
records the time between the arrival of the last acknowledgeable packet and
the time the Ack Vector is sent out. Since Linux does not (yet) implement
delayed Acks, the time difference will typically be small, since often the
arrival of a data packet triggers sending feedback at the HC-receiver.


Justification for changes in de-/allocation routines [can be removed]:
----------------------------------------------------------------------
* INIT_LIST_HEAD in dccp_ackvec_record_new was redundant, since the list
pointers were later overwritten when the node was added via list_add();
* dccp_ackvec_record_new() was called in a single place only;
* calls to list_del_init() before calling dccp_ackvec_record_delete() were
redundant, since subsequently the entire element was k-freed;
* since all calls to dccp_ackvec_record_delete() were preceded to a call to
list_del_init(), the WARN_ON test would never evaluate to true;
* since all calls to dccp_ackvec_record_delete() were made from within
list_for_each_entry_safe(), the test for avr == NULL was redundant;
* list_empty() in ackvec_free was redundant, since the same condition is
embedded in the loop condition of the subsequent list_for_each_entry_safe().

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

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# 55ebe3ab 04-Sep-2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp: Leave headroom for options when calculating the MPS

The Maximum Packet Size (MPS) is of interest for applications which want
to transfer data, so it is only relevant to the data transfer phase

dccp: Leave headroom for options when calculating the MPS

The Maximum Packet Size (MPS) is of interest for applications which want
to transfer data, so it is only relevant to the data transfer phase of a
connection (unless one wants to send data on the DCCP-Request, but that is
not considered here).

The strategy chosen to deal with this requirement is to leave room for only
such options that may appear on data packets.

A special consideration applies to Ack Vectors: this is purely guesswork,
since these can have any length between 3 and 1020 bytes. The strategy
chosen here is to subtract a configurable minimum, the value of 16 bytes
(2 bytes for type/length plus 14 Ack Vector cells) has been found by
experimentatation. If people experience this as too much or too little,
this could later be turned into a Kconfig option.

There are currently no CCID-specific header options which may appear on data
packets, hence it is not necessary to define a corresponding CCID field.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>

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# fade756f 04-Sep-2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>

dccp: Set per-connection CCIDs via socket options

With this patch, TX/RX CCIDs can now be changed on a per-connection basis, which
overrides the defaults set by the global sysctl variables for TX/RX

dccp: Set per-connection CCIDs via socket options

With this patch, TX/RX CCIDs can now be changed on a per-connection basis, which
overrides the defaults set by the global sysctl variables for TX/RX CCIDs.

To make full use of this facility, the remaining patches of this patch set are
needed, which track dependencies and activate negotiated feature values.

Note on the maximum number of CCIDs that can be registered:
-----------------------------------------------------------
The maximum number of CCIDs that can be registered on the socket is constrained
by the space in a Confirm/Change feature negotiation option.

The space in these in turn depends on the size of header options as defined
in RFC 4340, 5.8. Since this is a recurring constant, it has been moved from
ackvec.h into linux/dccp.h, clarifying its purpose.

Relative to this size, the maximum number of CCID identifiers that can be
present in a Confirm option (which always consumes 1 byte more than a Change
option, cf. 6.1) is 2 bytes less than the maximum TLV size: one for the
CCID-feature-type and one for the selected value.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

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Revision tags: v2.6.27-rc5, v2.6.27-rc4, v2.6.27-rc3, v2.6.27-rc2, v2.6.27-rc1, v2.6.26, v2.6.26-rc9, v2.6.26-rc8, v2.6.26-rc7, v2.6.26-rc6, v2.6.26-rc5, v2.6.26-rc4, v2.6.26-rc3, v2.6.26-rc2, v2.6.26-rc1, v2.6.25, v2.6.25-rc9, v2.6.25-rc8, v2.6.25-rc7, v2.6.25-rc6, v2.6.25-rc5, v2.6.25-rc4, v2.6.25-rc3, v2.6.25-rc2, v2.6.25-rc1, v2.6.24, v2.6.24-rc8, v2.6.24-rc7
# a47c5104 30-Dec-2007 Gerrit Renker <gerrit@erg.abdn.ac.uk>

[ACKVEC]: Reduce length of identifiers

This is reduces the length of the struct ackvec/ackvec_record fields. It is
a purely text-based replacement:

s#dccpavr_#avr_#g;
s#dccpav_#av_#g;

and increa

[ACKVEC]: Reduce length of identifiers

This is reduces the length of the struct ackvec/ackvec_record fields. It is
a purely text-based replacement:

s#dccpavr_#avr_#g;
s#dccpav_#av_#g;

and increases readability somewhat.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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