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2011-08-01dccp: support for the exchange of NN options in established state 1/2Gerrit Renker
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 <gerrit@erg.abdn.ac.uk> Signed-off-by: Samuel Jero <sj323707@ohio.edu> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.uk>
2010-10-06dccp: Kill dead code and add static markers.stephen hemminger
Remove dead code and make some functions static. Compile tested only. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-21dccp: Debugging functions for feature negotiationGerrit Renker
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 <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-21dccp: Initialisation and type-checking of feature sysctlsGerrit Renker
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 <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-21dccp: Initialisation framework for feature negotiationGerrit Renker
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 <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-08dccp: Clean up old feature-negotiation infrastructureGerrit Renker
The code removed by this patch is no longer referenced or used, the added lines update documentation and copyrights. 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>
2008-12-01dccp: Processing Confirm optionsGerrit Renker
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 <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-01dccp: Process incoming Change feature-negotiation optionsGerrit Renker
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 <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-23dccp: Header option insertion routine for feature-negotiationGerrit Renker
The patch extends existing code: * Confirm options divide into the confirmed value plus an optional preference list for SP values. Previously only the preference list was echoed for SP values, now the confirmed value is added as per RFC 4340, 6.1; * length and sanity checks are added to avoid illegal memory (or NULL) access. 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>
2008-11-23dccp: Support for Mandatory optionsGerrit Renker
Support for Mandatory options is provided by this patch, which will be used by subsequent feature-negotiation patches. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-23dccp: Increase the scope of variable-length htonl/ntohl functionsGerrit Renker
This extends the scope of two available functions, encode|decode_value_var, to work up to 6 (8) bytes, to match maximum requirements in the RFC. These functions are going to be used both by general option processing and feature negotiation code, hence declarations have been put into feat.h. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-23dccp: Set per-connection CCIDs via socket optionsGerrit Renker
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>
2008-11-16dccp: Deprecate old setsockopt frameworkGerrit Renker
The previous setsockopt interface, which passed socket options via struct dccp_so_feat, is complicated/difficult to use. Continuing to support it leads to ugly code since the old approach did not distinguish between NN and SP values. This patch removes the old setsockopt interface and replaces it with two new functions to register NN/SP values for feature negotiation. These are essentially wrappers around the internal __feat_register functions, with checking added to avoid * wrong usage (type); * changing values while the connection is in progress. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-12dccp: Registration routines for changing feature valuesGerrit Renker
Two registration routines, for SP and NN features, are provided by this patch, replacing a previous routine which was used for both feature types. These are internal-only routines and therefore start with `__feat_register'. It further exports the known limits of Sequence Window and Ack Ratio as symbolic constants. 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>
2008-11-04dccp: Per-socket initialisation of feature negotiationGerrit Renker
This provides feature-negotiation initialisation for both DCCP sockets and DCCP request_sockets, to support feature negotiation during connection setup. It also resolves a FIXME regarding the congestion control initialisation. Thanks to Wei Yongjun for help with the IPv6 side of this patch. 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>
2008-11-04dccp: Basic data structure for feature negotiationGerrit Renker
This patch prepares for the new and extended feature-negotiation routines. The following feature-negotiation data structures are provided: * a container for the various (SP or NN) values, * symbolic state names to track feature states, * an entry struct which holds all current information together, * elementary functions to fill in and process these structures. Entry structs are arranged as FIFO for the following reason: RFC 4340 specifies that if multiple options of the same type are present, they are processed in the order of their appearance in the packet; which means that this order needs to be preserved in the local data structure (the later insertion code also respects this order). The struct list_head has been chosen for the following reasons: the most frequent operations are * add new entry at tail (when receiving Change or setting socket options); * delete entry (when Confirm has been received); * deep copy of entire list (cloning from listening socket onto request socket). The NN value has been set to 64 bit, which is a currently sufficient upper limit (Sequence Window feature has 48 bit). Thanks to Arnaldo, who contributed the streamlined layout of the entry struct. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[DCCP]: Remove unused and redundant validation functionsGerrit Renker
This removes two inlines which were both called in a single function only: 1) dccp_feat_change() is always called with either DCCPO_CHANGE_L or DCCPO_CHANGE_R as argument * from dccp_set_socktopt_change() via do_dccp_setsockopt() with DCCP_SOCKOPT_CHANGE_R/L * from __dccp_feat_init() via dccp_feat_init() also with DCCP_SOCKOPT_CHANGE_R/L. Hence the dccp_feat_is_valid_type() is completely unnecessary and always returns true. 2) Due to (1), the length test reduces to 'len >= 4', which in turn makes dccp_feat_is_valid_length() unnecessary. Furthermore, the inline function dccp_feat_is_reserved() was unfolded, since only called in a single place. 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>
2007-02-10[NET] DCCP: Fix whitespace errors.YOSHIFUJI Hideaki
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02[DCCP]: Make feature negotiation more readableGerrit Renker
This patch replaces cryptic feature negotiation messages of type Oct 31 15:42:20 kernel: dccp_feat_change: feat change type=32 feat=1 Oct 31 15:42:21 kernel: dccp_feat_change: feat change type=34 feat=1 Oct 31 15:42:21 kernel: dccp_feat_change: feat change type=32 feat=5 into ones of type: Nov 2 13:54:45 kernel: dccp_feat_change: ChangeL(CCID (1), 3) Nov 2 13:54:45 kernel: dccp_feat_change: ChangeR(CCID (1), 3) Nov 2 13:54:45 kernel: dccp_feat_change: ChangeL(Ack Ratio (5), 2) Also, * completed the feature number list wrt RFC 4340 sec. 6.4 * annotating which ones have been implemented so far * implemented rudimentary sanity checking in feat.c (FIXMEs) * some minor fixes Commiter note: uninlined dccp_feat_name and dccp_feat_typename, for consistency with dccp_{state,packet}_name, that, BTW, should be compiled only if CONFIG_IP_DCCP_DEBUG is selected, leaving this to another cset tho. Also shortened dccp_feat_negotiation_debug to dccp_feat_debug. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02[DCCP]: Add sysctls to control retransmission behaviourGerrit Renker
This adds 3 sysctls which govern the retransmission behaviour of DCCP control packets (3way handshake, feature negotiation). It removes 4 FIXMEs from the code. The close resemblance of sysctl variables to their TCP analogues is emphasised not only by their name, but also by giving them the same initial values. This is useful since there is not much practical experience with DCCP yet. Furthermore, with regard to the previous patch, it is now possible to limit the number of keepalive-Responses by setting net.dccp.default.request_retries (also a bit like in TCP). Lastly, added documentation of all existing DCCP sysctls. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-09-22[DCCP]: Shift sysctls into feat.hIan McDonald
This shifts further sysctls into feat.h. No change in functionality - shifting code only. Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-24[DCCP]: Fix default sequence window sizeIan McDonald
When using the default sequence window size (100) I got the following in my logs: Jun 22 14:24:09 localhost kernel: [ 1492.114775] DCCP: Step 6 failed for DATA packet, (LSWL(6279674225) <= P.seqno(6279674749) <= S.SWH(6279674324)) and (P.ackno doesn't exist or LAWL(18798206530) <= P.ackno(1125899906842620) <= S.AWH(18798206548), sending SYNC... Jun 22 14:24:09 localhost kernel: [ 1492.115147] DCCP: Step 6 failed for DATA packet, (LSWL(6279674225) <= P.seqno(6279674750) <= S.SWH(6279674324)) and (P.ackno doesn't exist or LAWL(18798206530) <= P.ackno(1125899906842620) <= S.AWH(18798206549), sending SYNC... I went to alter the default sysctl and it didn't take for new sockets. Below patch fixes this. I think the default is too low but it is what the DCCP spec specifies. As a side effect of this my rx speed using iperf goes from about 2.8 Mbits/sec to 3.5. This is still far too slow but it is a step in the right direction. Compile tested only for IPv6 but not particularly complex change. Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[DCCP] feat: Pass dccp_minisock ptr where only the minisock is usedArnaldo Carvalho de Melo
This is in preparation for having a dccp_minisock embedded into dccp_request_sock so that feature negotiation can be done prior to creating the full blown dccp_sock. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[DCCP]: Initial feature negotiation implementationAndrea Bittau
Still needs more work, but boots and doesn't crashes, even does some negotiation! 18:38:52.174934 127.0.0.1.43458 > 127.0.0.1.5001: request <change_l ack_ratio 2, change_r ccid 2, change_l ccid 2> 18:38:52.218526 127.0.0.1.5001 > 127.0.0.1.43458: response <nop, nop, change_l ack_ratio 2, confirm_r ccid 2 2, confirm_l ccid 2 2, confirm_r ack_ratio 2> 18:38:52.185398 127.0.0.1.43458 > 127.0.0.1.5001: <nop, confirm_r ack_ratio 2, ack_vector0 0x00, elapsed_time 212> :-) 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>