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2025-04-11net: Retire DCCP socket.Kuniyuki Iwashima
DCCP was orphaned in 2021 by commit 054c4610bd05 ("MAINTAINERS: dccp: move Gerrit Renker to CREDITS"), which noted that the last maintainer had been inactive for five years. In recent years, it has become a playground for syzbot, and most changes to DCCP have been odd bug fixes triggered by syzbot. Apart from that, the only changes have been driven by treewide or networking API updates or adjustments related to TCP. Thus, in 2023, we announced we would remove DCCP in 2025 via commit b144fcaf46d4 ("dccp: Print deprecation notice."). Since then, only one individual has contacted the netdev mailing list. [0] There is ongoing research for Multipath DCCP. The repository is hosted on GitHub [1], and development is not taking place through the upstream community. While the repository is published under the GPLv2 license, the scheduling part remains proprietary, with a LICENSE file [2] stating: "This is not Open Source software." The researcher mentioned a plan to address the licensing issue, upstream the patches, and step up as a maintainer, but there has been no further communication since then. Maintaining DCCP for a decade without any real users has become a burden. Therefore, it's time to remove it. Removing DCCP will also provide significant benefits to TCP. It allows us to freely reorganize the layout of struct inet_connection_sock, which is currently shared with DCCP, and optimize it to reduce the number of cachelines accessed in the TCP fast path. Note that we keep DCCP netfilter modules as requested. [3] Link: https://lore.kernel.org/netdev/20230710182253.81446-1-kuniyu@amazon.com/T/#u #[0] Link: https://github.com/telekom/mp-dccp #[1] Link: https://github.com/telekom/mp-dccp/blob/mpdccp_v03_k5.10/net/dccp/non_gpl_scheduler/LICENSE #[2] Link: https://lore.kernel.org/netdev/Z_VQ0KlCRkqYWXa-@calendula/ #[3] Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paul Moore <paul@paul-moore.com> (LSM and SELinux) Acked-by: Casey Schaufler <casey@schaufler-ca.com> Link: https://patch.msgid.link/20250410023921.11307-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
Based on 1 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 as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-16dccp: re-enable debug macroGerrit Renker
dccp tfrc: revert This reverts 6aee49c558de ("dccp: make local variable static") since the variable tfrc_debug is referenced by the tfrc_pr_debug(fmt, ...) macro when TFRC debugging is enabled. If it is enabled, use of the macro produces a compilation error. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-04dccp: make local variable staticstephen hemminger
Make DCCP module config variable static, only used in one file. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19net: dccp: Remove extern from function prototypesJoe Perches
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>
2011-12-19module_param: make bool parameters really bool (net & drivers/net)Rusty Russell
module_param(bool) used to counter-intuitively take an int. In fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy trick. It's time to remove the int/unsigned int option. For this version it'll simply give a warning, but it'll break next kernel version. (Thanks to Joe Perches for suggesting coccinelle for 0/1 -> true/false). Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-21dccp tfrc/ccid-3: computing the loss rate from the Loss Event RateGerrit Renker
This adds a function to take care of the following, separate cases occurring in the computation of the Loss Rate p: * 1/(2^32-1) is mapped into 0% as per RFC 4342, 8.5; * 1/0 is mapped into 100%, the maximum; * to avoid that p = 1/x is rounded down to 0 when x is very large, since this means accidentally re-entering slow-start indicated by p == 0, the minimum resolution value of p is now returned instead; * a bug in ccid3_hc_rx_getsockopt is fixed: 1/0 was mapped into ~0U. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2009-09-14net-next-2.6 [PATCH 1/1] dccp: ccids whitespace-cleanup / CodingStyleGerrit Renker
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>
2009-01-04dccp: Integrate the TFRC library with DCCPGerrit Renker
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>
2008-06-11dccp ccid-3: X truncated due to type conversionGerrit Renker
This fixes a bug in computing the inter-packet-interval t_ipi = s/X: scaled_div32(a, b) uses u32 for b, but in "scaled_div32(s, X)" the type of the sending rate `X' is u64. Since X is scaled by 2^6, this truncates rates greater than 2^26 Bps (~537 Mbps). Using full 64-bit division now. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-06-11dccp: Fix sparse warningsGerrit Renker
This patch fixes the following sparse warnings: * nested min(max()) expression: net/dccp/ccids/ccid3.c:91:21: warning: symbol '__x' shadows an earlier one net/dccp/ccids/ccid3.c:91:21: warning: symbol '__y' shadows an earlier one * Declaration of function prototypes in .c instead of .h file, resulting in "should it be static?" warnings. * Declared "struct dccpw" static (local to dccp_probe). * Disabled dccp_delayed_ack() - not fully removed due to RFC 4340, 11.3 ("Receivers SHOULD implement delayed acknowledgement timers ..."). * Used a different local variable name to avoid net/dccp/ackvec.c:293:13: warning: symbol 'state' shadows an earlier one net/dccp/ackvec.c:238:33: originally declared here * Removed unused functions `dccp_ackvector_print' and `dccp_ackvec_print'. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-01-28[TFRC]: Ringbuffer to track loss interval historyGerrit Renker
A ringbuffer-based implementation of loss interval history is easier to maintain, allocate, and update. The `swap' routine to keep the RX history sorted is due to and was written by Arnaldo Carvalho de Melo, simplifying an earlier macro-based variant. Details: * access to the Loss Interval Records via macro wrappers (with safety checks); * simplified, on-demand allocation of entries (no extra memory consumption on lossless links); cache allocation is local to the module / exported as service; * provision of RFC-compliant algorithm to re-compute average loss interval; * provision of comprehensive, new loss detection algorithm - support for all cases of loss, including re-ordered/duplicate packets; - waiting for NDUPACK=3 packets to fill the hole; - updating loss records when a late-arriving packet fills a hole. 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[TFRC]: Provide central source file and debug facilityGerrit Renker
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[CCID3]: Inline for moving averageGerrit Renker
The moving average computation occurs so frequently in the CCID 3 code that it merits an inline function of its own. This is uses a suggestion by Arnaldo as per http://www.mail-archive.com/dccp@vger.kernel.org/msg01662.html 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>
2006-12-11[DCCP]: Simplify TFRC calculationGerrit Renker
In migrating towards using the newer functions scaled_div/scaled_div32 for TFRC computations mapped from floating-point onto integer arithmetic, this completes the last stage of modifications. In particular, the overflow case for computing X_calc is circumvented by * breaking the computation into two stages * the first stage, res = (s*1E6)/R, cannot overflow due to use of u64 * in the second stage, res = (res*1E6)/f, overflow on u32 is avoided due to (i) returning UINT_MAX in this case (which is logically appropriate) and (ii) issuing a warning message into the system log (since very likely there is a problem somewhere else with the parameters) Lastly, all such scaling operations are now exported into tfrc.h, since actually this form of scaled computation is specific to TFRC and not to CCID3. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-08-26[DCCP]: Update contact details and copyrightIan McDonald
Just updating copyright and contacts Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[DCCP]: Move the calc_X routines to dccp_tfrc_libArnaldo Carvalho de Melo
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>