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  1. 04 Sep, 2008 10 commits
    • Gerrit Renker's avatar
      dccp: Per-socket initialisation of feature negotiation · 828755ce
      Gerrit Renker authored 
      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: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: default avatarIan McDonald <ian.mcdonald@jandi.co.nz>
      828755ce
    • Gerrit Renker's avatar
      dccp: List management for new feature negotiation · 3001fc05
      Gerrit Renker authored 
      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: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: default avatarIan McDonald <ian.mcdonald@jandi.co.nz>
      3001fc05
    • Gerrit Renker's avatar
      dccp: Implement lookup table for feature-negotiation information · b4eec206
      Gerrit Renker authored 
      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: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: default avatarIan McDonald <ian.mcdonald@jandi.co.nz>
      b4eec206
    • Gerrit Renker's avatar
      dccp: Basic data structure for feature negotiation · 5c7c9451
      Gerrit Renker authored 
      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: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: default avatarIan McDonald <ian.mcdonald@jandi.co.nz>
      5c7c9451
    • Gerrit Renker's avatar
      dccp ccid-3: Replace lazy BUG_ON with condition · 959fd992
      Gerrit Renker authored 
      The BUG_ON(w_tot == 0) only holds if there is no more than 1 loss interval in
the loss history. If there is only a single loss interval, the calc_i_mean()
routine need in fact not be called (RFC 3448, 6.3.1). 
Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
      959fd992
    • Gerrit Renker's avatar
      dccp: Toggle debug output without module unloading · 43264991
      Gerrit Renker authored 
      This sets the sysfs permissions so that root can toggle the `debug'
parameter available for nearly every DCCP module. This is useful 
since there are various module inter-dependencies. The debug flag
can now be toggled at runtime using

  echo 1 > /sys/module/dccp/parameters/dccp_debug
  echo 1 > /sys/module/dccp_ccid2/parameters/ccid2_debug
  echo 1 > /sys/module/dccp_ccid3/parameters/ccid3_debug
  echo 1 > /sys/module/dccp_tfrc_lib/parameters/tfrc_debug

The last is not very useful yet, since no code at the moment calls
the tfrc_debug() macro.
Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
      43264991
    • Gerrit Renker's avatar
      dccp: Empty the write queue when disconnecting · 48816322
      Gerrit Renker authored 
      dccp_disconnect() can be called due to several reasons:

 1. when the connection setup failed (inet_stream_connect());
 2. when shutting down (inet_shutdown(), inet_csk_listen_stop());
 3. when aborting the connection (dccp_close() with 0 linger time).

In case (1) the write queue is empty. This patch empties the write queue,
if in case (2) or (3) it was not yet empty.

This avoids triggering the write-queue BUG_TRAP in sk_stream_kill_queues()
later on.

It also seems natural to do: when breaking an association, to delete all
packets that were originally intended for the soon-disconnected end (compare
with call to tcp_write_queue_purge in tcp_disconnect()).
Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
      48816322
    • Gerrit Renker's avatar
      dccp: Fill in the Data fields for "Option Error" Resets · eac7726b
      Gerrit Renker authored 
      This updates the use of the `out_invalid_option' label, which produces a 
Reset (code 5, "Option Error"), to fill in the  Data1...Data3 fields as
specified in RFC 4340, 5.6.
Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
      eac7726b
    • Gerrit Renker's avatar
      dccp: Silently ignore options with nonsensical lengths · faf61c33
      Gerrit Renker authored 
      This updates the option-parsing code with regard to RFC 4340, 5.8:
 "[..] options with nonsensical lengths (length byte less than two or more
  than the remaining space in the options portion of the header) MUST be
  ignored, and any option space following an option with nonsensical length
  MUST likewise be ignored."

Hence in the following cases erratic options will be ignored:
 1. The type byte of a multi-byte option is the last byte of the header
    options (i.e. effective option length of 1).
 2. The value of the length byte is less than the minimum 2. This has been 
    changed from previously 3: although no multi-byte option with a length
    less than 3 yet exists (cf. table 3 in 5.8), a length of 2 is valid.
    (The switch-statement in dccp_parse has further per-option length checks.)
 3. The option length exceeds the length of the remaining option space.
Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
      faf61c33
    • Wei Yongjun's avatar
      dccp: Always generate a Reset in response to option errors · ba1a6c7b
      Wei Yongjun authored 
      RFC4340 states that if a packet is received with an option error (such as a
Mandatory Option as the last byte of the option list), the endpoint should
repond with a Reset.

In the LISTEN and RESPOND states, the endpoint correctly reponds with Reset,
while in the REQUEST/OPEN states, packets with option errors are just ignored.

The packet sequence is as follows:

Case 1:

  Endpoint A                           Endpoint B
  (CLOSED)                             (CLOSED)

               <----------------       REQUEST

  RESPONSE     ----------------->      (*1)
  (with invalid option)
               <----------------       RESET
                                       (with Reset Code 5, "Option Error")

  (*1) currently just ignored, no Reset is sent

Case 2:

  Endpoint A                           Endpoint B
  (OPEN)                               (OPEN)

  DATA-ACK     ----------------->      (*2)
  (with invalid option)
               <----------------       RESET
                                       (with Reset Code 5, "Option Error")

  (*2) currently just ignored, no Reset is sent

This patch fixes the problem, by generating a Reset instead of silently
ignoring option errors.
Signed-off-by: default avatarWei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
      ba1a6c7b
  3. 03 Sep, 2008 21 commits
  5. 02 Sep, 2008 9 commits
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