This patch starts the new implementation of feature negotiation:
1. Although it is theoretically possible to perform feature negotiation at any
time (and RFC 4340 supports this), in practice this is prohibitively complex,
as it requires to put traffic on hold for each new negotiation.
2. As a byproduct of restricting feature negotiation to connection setup, the
feature-negotiation retransmit timer is no longer required. This part is now
mapped onto the protocol-level retransmission.
Details indicating why timers are no longer needed can be found on
http://www.erg.abdn.ac.uk/users/gerrit/dccp/notes/feature_negotiation/\
implementation_notes.html
This patch disables anytime negotiation, subsequent patches work out full
feature negotiation support for connection setup.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
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>
This adds list fields and list management functions for the new feature
negotiation implementation. The new code is kept in parallel to the old
code, until removed at the end of the patch set.
Thanks to Arnaldo for suggestions to improve the code.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
A lookup table for feature-negotiation information, extracted from RFC 4340/42,
is provided by this patch. All currently known features can be found in this
table, along with their feature location, their default value, and type.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
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).
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
dccp_feat_change() validates length and on error is returning 1.
This happens to work since call chain is checking for 0 == success,
but this is returned to userspace, so make it a real error value.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This removes several `XXX' references which indicate a missing support
for non-1-byte feature values: this is unnecessary, as all currently known
(standardised) SP feature values are 1-byte quantities.
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>
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>
There's a memory leak in net/dccp/feat.c::dccp_feat_empty_confirm(). If we
hit the 'default:' case of the 'switch' statement, then we return without
freeing 'opt', thus leaking 'struct dccp_opt_pend' bytes.
The leak is fixed easily enough by adding a kfree(opt); before the return
statement.
The patch also changes the layout of the 'switch' to be more in line with
CodingStyle.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
That accumulated over the last months hackaton, shame on me for not
using git-apply whitespace helping hand, will do that from now on.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
This reaps the benefit of the earlier patch, which changed the type of
CCID 3 states to use enums, in that many conditions are now simplified
and the number of possible (unexpected) values is greatly reduced.
In a few instances, this also allowed to simplify pre-conditions; where
care has been taken to retain logical equivalence.
[DCCP]: Introduce a consistent BUG/WARN message scheme
This refines the existing set of DCCP messages so that
* BUG(), BUG_ON(), WARN_ON() have meaningful DCCP-specific counterparts
* DCCP_CRIT (for severe warnings) is not rate-limited
* DCCP_WARN() is introduced as rate-limited wrapper
Using these allows a faster and cleaner transition to their original
counterparts once the code has matured into a full DCCP implementation.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
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>
From: Randy Dunlap <rdunlap@xenotime.net>
Use NULL instead of 0 for pointers.
Fix these sparse warnings:
net/dccp/feat.c:207:20: warning: Using plain integer as NULL pointer
net/dccp/feat.c:325:21: warning: Using plain integer as NULL pointer
net/dccp/feat.c:526:20: warning: Using plain integer as NULL pointer
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
This will later be included in struct dccp_request_sock so that we can
have per connection feature negotiation state while in the 3way
handshake, when we clone the DCCP_ROLE_LISTEN socket (in
dccp_create_openreq_child) we'll just copy this state from
dreq_minisock to dccps_minisock.
Also the feature negotiation and option parsing code will mostly touch
dccps_minisock, which will simplify some stuff.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change the CCID upon successful feature negotiation.
Commiter note: patch mostly rewritten to use the new ccid API.
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>
