Commit Graph

212 Commits

Author SHA1 Message Date
Gerrit Renker
797eba424d [TFRC]: The function tfrc_rx_hist_entry_delete() is not used anymore
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>
2008-01-28 14:57:03 -08:00
Gerrit Renker
78282d2af5 [TFRC]: Move comment.
Moved up the comment "Receiver routines" above the first occurrence of
RX history routines.

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>
2008-01-28 14:57:03 -08:00
Arnaldo Carvalho de Melo
b84a2189c4 [TFRC]: New rx history code
Credit here goes to Gerrit Renker, that provided the initial implementation for
this new codebase.

I modified it just to try to make it closer to the existing API, renaming some
functions, add namespacing and fix one bug where the tfrc_rx_hist_alloc was not
freeing the allocated ring entries on the error path.

Original changeset comment from Gerrit:
      -----------
This provides a new, self-contained and generic RX history service for TFRC
based protocols.

Details:
 * new data structure, initialisation and cleanup routines;
 * allocation of dccp_rx_hist entries local to packet_history.c,
   as a service exported by the dccp_tfrc_lib module.
 * interface to automatically track highest-received seqno;
 * receiver-based RTT estimation (needed for instance by RFC 3448, 6.3.1);
 * a generic function to test for `data packets' as per  RFC 4340, sec. 7.7.

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>
2008-01-28 14:56:43 -08:00
Gerrit Renker
30a0eacd47 [CCID3]: The receiver of a half-connection does not set window counter values
Only the sender sets window counters [RFC 4342, sections 5 and 8.1].

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 14:56:43 -08:00
Arnaldo Carvalho de Melo
d58d1af03a [TFRC]: Rename dccp_rx_ to tfrc_rx_
This is in preparation for merging the new rx history code written by Gerrit Renker.

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>
2008-01-28 14:56:42 -08:00
Arnaldo Carvalho de Melo
34a9e7ea91 [TFRC]: Make the rx history slab be global
This is in preparation for merging the new rx history code written by Gerrit Renker.

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>
2008-01-28 14:56:41 -08:00
Arnaldo Carvalho de Melo
e9c8b24a6a [TFRC]: Rename tfrc_tx_hist to tfrc_tx_hist_slab, for consistency
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>
2008-01-28 14:56:40 -08:00
Gerrit Renker
c40616c597 [TFRC]: Provide central source file and debug facility
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 14:56:39 -08:00
Arnaldo Carvalho de Melo
9108d5f4b2 [TFRC]: Hide tx history details from the CCIDs
Based on a previous patch by Gerrit Renker.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:19 -08:00
Arnaldo Carvalho de Melo
276f2edc52 [TFRC]: Migrate TX history to singly-linked lis
This patch was based on another made by Gerrit Renker, his changelog was:

    ------------------------------------------------------
The patch set migrates TFRC TX history to a singly-linked list.

The details are:
 * use of a consistent naming scheme (all TFRC functions now begin with `tfrc_');
 * allocation and cleanup are taken care of internally;
 * provision of a lookup function, which is used by the CCID TX infrastructure
   to determine the time a packet was sent (in turn used for RTT sampling);
 * integration of the new interface with the present use in CCID3.
    ------------------------------------------------------

Simplifications I did:

. removing the tfrc_tx_hist_head that had a pointer to the list head and
  another for the slabcache.
. No need for creating a slabcache for each CCID that wants to use the TFRC
  tx history routines, create a single slabcache when the dccp_tfrc_lib module
  init routine is called.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:11 -08:00
Gerrit Renker
dcfbc7e97a [CCID2]: Remove misleading comment
This removes a comment which identifies an `issue' with dccp_write_xmit() where there is none.
The comment assumes it is possible that a packet is sent between the calls to

	ccid_hc_tx_send_packet(),
	dccp_transmit_skb(),
	ccid_hc_tx_packet_sent()

(in the above order) in dccp_write_xmit().

I think that this is impossible, since dccp_write_xmit() is always called under lock:

 * when called as dccp_write_xmit(sk, 1) from dccp_send_close(), the socket is locked
   (see code comment above dccp_send_close());
 * when called as dccp_write_xmit(sk, 0) from dccp_send_msg(), it is after lock_sock() has been called;
 * when called as dccp_write_xmit(sk, 0) from dccp_write_xmit_timer(), bh_lock_sock() has been called
   and the if/else statement has made sure that sk_lock.owner is not set;
 * there are no other places where dccp_write_xmit() is called.

Furthermore, the debug statement for printing the sequence number of the packet just sent has been
removed, since the entire list is being printed anyway and so the entry of that number appears last.

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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:01 -08:00
Gerrit Renker
a302002516 [CCID2]: Remove redundant ack-counting variable
The code used two different variables to count Acks, one of them redundant.
This patch reduces the number of Ack counters to one.

The type of the Ack counter has also been changed to u32 (twice the range of int);
and the variable has been renamed into `packets_acked' - for consistency with
RFC 3465 (and similarly named variables are used by TCP and SCTP).

Lastly, a slightly less aggressive `maxincr' increment is used (for even Ack Ratios,
maxincr was Ack Ratio/2 + 1 instead of Ack Ratio/2).

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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:00 -08:00
Gerrit Renker
83399361c3 [CCID2]: Remove redundant synchronisation variable
This removes the synchronisation variable `ccid2hctx_sendwait', which is set to 1
when the CCID2 sender may send a new packet, and which is set to 0 otherwise

The variable is redundant, since it is only used in combination with the hc_tx_send_packet/
hc_tx_packet_sent function pair. Both functions are called under socket lock, so the
following happens when the CCID2 may send a new packet:

 * it sets sendwait = 1 in tx_send_packet and returns 0;
 * the subsequent call to tx_packet_sent clears the sendwait flag;
 * since tx_send_packet returns 0 if and only if sendwait == 1, the BUG_ON condition
   in tx_packet_sent is never satisfied, since that function is never called when
   tx_send_packet returns a value different from 0 (cf. dccp_write_xmit);
 * the call to tx_packet_sent clears the flag so that the condition "!sendwait" is
   true the next time tx_packet_sent is called.

In other words, it is sufficient to just return 0 / not-0 to synchronise tx_send_packet
and tx_packet_sent -- which is what the patch does.

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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:59 -08:00
Gerrit Renker
da98e0b5d4 [CCID2]: Redundant debugging output
This reduces the amount of redundant debugging messages:

 * pipe/cwnd are printed in both tx_send_packet() and tx_packet_sent().
   Both functions are called immediately after one another, so one occurrence is sufficient.

 * Since tx_packet_sent() prints pipe/cwnd already, the second printk for pipe is redundant.

 * In tx_packet_sent() the check_sanity function is called twice (at the begin and at the end).

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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:59 -08:00
Gerrit Renker
95b21d7e9d [CCID2]: Replace pipe assignment-function with assignment
The function ccid2_change_pipe only does an assignment. This patch simplifies the code by
replacing the function with the assignment it performs.

Furthermore, the type of pipe is promoted from `signed' to unsigned (increasing the range).
As a result, a BUG_ON test for negative values now becomes obsolete (for safety not removed,
but replaced with a less annoying `DCCP_BUG').

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 14:54:58 -08:00
Gerrit Renker
3deeadd74b [CCID2]: Replace cwnd assignment-function with assignment
The current function ccid2_change_cwnd in effect makes only an assignment, as
the test whether cwnd has reached 0 is only required when cwnd is halved.

This patch simplifies the code by replacing the function with the assignment
it performs.

Furthermore, since ssthresh derives from cwnd and appears in many assignments and
comparisons, the type of ssthresh has also been changed to match that of cwnd.

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 14:54:57 -08:00
Gerrit Renker
63df18ad7f [CCID2]: Replace read-only variable with constant
This replaces the field member `numdupack', which was used as a read-only
constant in the code, with a #define.

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 14:54:57 -08:00
Gerrit Renker
7792cd8885 [CCID2]: Remove unused variable
This removes a variable `ccid2hctx_sent' which is incremented but
never referenced/read (i.e., dead code).

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 14:54:56 -08:00
Gerrit Renker
900bfed471 [CCID2]: Disable broken Ack Ratio adaptation algorithm
This comments out a problematic section comprising a half-finished algorithm:

 - The variable `ccid2hctx_ackloss' is never initialised to a value different from 0 and
   hence in fact is a read-only constant.
 - The `arsent' variable counts packets other than Acks (it is incremented for every packet),
   and there is no test for Ack Loss.
 - The concept of counting Acks as such leads to a complex calculation, and the calculation
   at the moment is inconsistent with this concept.
   The problem is that the number of Acks - rather than the number of windows - is counted,
   which leads to a complex (cubic/quadratic) expression - this is not even implemented.

In its current state, the commented-out algorithm interfers with normal processing by
changing Ack Ratio incorrectly, and at the wrong times.

A new algorithm is necessary, which will not necessarily use the same variables as used by
the unfinished one; hence the old variables have been removed.

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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:55 -08:00
Gerrit Renker
b00d2bbc45 [CCID2]: Larger initial windows also for CCID2
RFC 4341, sec. 5 states that "The cwnd parameter is initialized to at most
four packets for new connections, following the rules from [RFC3390]", which
is implemented by this patch.

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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:55 -08:00
Gerrit Renker
d50ad163e6 [CCID2]: Deadlock and spurious timeouts when Ack Ratio > cwnd
This patch removes a bug in the current code. I agree with Andrea's comment
that there is a problem here but the way it is treated does not fix it.

The problem is that whenever Ack Ratio > cwnd, starvation/deadlock occurs:
 * the receiver will not send an Ack until (Ack Ratio - cwnd) data packets
   have arrived;
 * the sender will not send any data packet before the receipt of an Ack
   advances the send window.
The only way that the connection then progresses was via RTO timeout. In one
extreme case (bulk transfer), it was observed that this happened for every single
packet; i.e. hundreds of packets, each a RTO timeout of 1..3 seconds apart:
a transfer which normally would take a fraction of a second thus grew to
several minutes.

The solution taken by this approach is to observe the relation

                   "Ack Ratio <= cwnd"

by using the constraint (1) from RFC 4341, 6.1.2; i.e. set

                 Ack Ratio = ceil(cwnd / 2)

and update it whenever either Ack Ratio or cwnd change. This ensures that
the deadlock problem can not arise.

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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:53 -08:00
Gerrit Renker
df054e1d00 [CCID2]: Don't assign negative values to Ack Ratio
Since it makes not sense to assign negative values to Ack Ratio, this
patch disallows this possibility.

As a consequence, a Bug test for negative Ack Ratio values becomes obsolete.

Furthermore, a check against overflow (as Ack Ratio may not exceed 2 bytes,
due to RFC 4340, 11.3) has been added.

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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:53 -08:00
Gerrit Renker
cfbbeabc88 [CCID2]: Fix sequence number arithmetic/comparisons
This replaces use of normal subtraction with modulo-48 subtraction.

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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:52 -08:00
Gerrit Renker
3de5489f47 [CCID2]: Bug in reading Ack Vectors
In CCID2 the receiver-history is sorted in ascending order of sequence number,
but the processing of received Ack Vectors requires the list traversal in the
opposite direction.

The current code has a bug in this regard: the list traversal is upwards. As a
consequence, only Ack Vectors with a run length of 1 will pass, in all other
Ack Vectors the remaining (acked) sequence numbers are missed, and may later
falsely be identified as lost.

Note: This bug is only visible when Ack Ratio > 1, since otherwise the run
      lengths of Ack Vectors are 0.

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 14:54:51 -08:00
Gerrit Renker
6d57b43bf8 [DCCP]: Remove redundant dependency on IP_DCCP
This cleans up the consequences of an earlier patch which
introduced the `if IP_DCCP' clause into net/dccp/Kconfig.

The CCID Kconfig menu is sourced within this clause; as a
consequence, all tests of type `depends on IP_DCCP' are now
redundant.

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 14:54:46 -08:00
Gerrit Renker
e333b3edc4 [DCCP]: Promote CCID2 as default CCID
This patch addresses the following problems:

 1. DCCP relies for its proper functioning on having at least one CCID module
    enabled (as in TCP plugable congestion control). Currently it is possible to
    disable both CCIDs and thus leave the DCCP module in a compiled, but entirely
    non-functional state: no sockets can be created when no CCID is available.
    Furthermore, the protocol is (again like TCP) not intended to be used without
    CCIDs. Last, a non-empty CCID list is needed for doing CCID feature negotiation.

 2. Internally the default CCID that is advertised by the Linux host is set to CCID2
    (DCCPF_INITIAL_CCID in include/linux/dccp.h). Disabling CCID2 in the Kconfig
    menu without changing the defaults leads to a failure `module not found' when
    trying to load the dccp module (which internally tries to load the default CCID).

 3. The specification (RFC 4340, sec. 10) treats CCID2 somewhat like a
    `minimum common denominator'; the specification says that:

    * "New connections start with CCID 2 for both endpoints"

    * "A DCCP implementation intended for general use, such as an implementation in a
       general-purpose operating system kernel, SHOULD implement at least CCID 2.
       The intent is to make CCID 2 broadly available for interoperability [...]"

    Providing CCID2 as minimum-required CCID (like Reno/Cubic in TCP) thus seems reasonable.

Hence this patch automatically selects CCID2 when DCCP is enabled. Documentation also added.

Discussions with Ian McDonald on this subject are gratefully acknowledged.

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 14:54:46 -08:00
Gerrit Renker
c3ada46a00 [CCID3]: Inline for moving average
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>
2008-01-28 14:54:43 -08:00
Gerrit Renker
a5358fdc9c [CCID3]: Accurately determine idle & application-limited periods
This fixes/updates the handling of idle and application-limited periods in CCID3,
which currently is broken: there is no detection as to how long a sender has been
idle - there is only one flag which is toggled in between function calls.

Being obsolete now, the `idle' flag is removed.

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 14:54:42 -08:00
Gerrit Renker
eb279b79c4 [CCID3]: Ignore trivial amounts of elapsed time
This patch fixes a previously undiscovered bug; the problem is in computing
the elapsed time as the time between `receiving' the packet (i.e. skb enters
CCID module) and sending feedback:

     - there is no layer-processing, queueing, or delay involved,
     - hence the elapsed time is in the order of 1 function call
     - this is in the dimension of maximally 50..100usec
     - which renders the use of elapsed time almost entirely useless.

The fix is simply to ignore such trivial amounts of elapsed time.

As a further advantage, the now useless elapsed_time field can be removed from
the socket, which reduces the socket structure by another four bytes.

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 14:54:42 -08:00
Gerrit Renker
6c08b2cf48 [CCID3]: Revert use of MSS instead of s
This updates the CCID3 code with regard to two instances of using `MSS' in place of `s':

 1. The RFC3390-based initial rate: both rfc3448bis as well as the Faster Restart
    draft now consistently use `s' instead of MSS.

 2. Now agrees with section 4.2 of rfc3448bis: "If the sender is ready to send data when
    it does not yet have a round trip sample, the value of X is set to s bytes per
    second, for segment size s [...]"

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 14:54:41 -08:00
Pavel Emelyanov
b24b8a247f [NET]: Convert init_timer into setup_timer
Many-many code in the kernel initialized the timer->function
and  timer->data together with calling init_timer(timer). There
is already a helper for this. Use it for networking code.

The patch is HUGE, but makes the code 130 lines shorter
(98 insertions(+), 228 deletions(-)).

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:53:35 -08:00
Joe Perches
5e8e034cc5 [DCCP]: Spelling fixes
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-12-20 13:59:39 -08:00
Joe Perches
4756daa3b6 [DCCP]: Add missing "space"
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-19 23:46:02 -08:00
Gerrit Renker
24c667db59 [CCID2/3]: Initialisation assignments of 0 are redundant
Assigning initial values of `0' is redundant when loading a new CCID structure,
since in net/dccp/ccid.c the entire CCID structure is zeroed out prior to
initialisation in ccid_new():

    	struct ccid {
    		struct ccid_operations *ccid_ops;
    		char		       ccid_priv[0];
    	};

    	// ...
    	if (rx) {
    		memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
    		if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
    		    ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
    			goto out_free_ccid;
    	} else {
    		memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
    		/* analogous to the rx case */
    	}

This patch therefore removes the redundant assignments. Thanks to Arnaldo for
the inspiration.

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>
2007-10-24 10:53:01 -02:00
Gerrit Renker
76fd1e87d9 [DCCP]: Unaligned pointer access
This fixes `unaligned (read) access' errors of the type

Kernel unaligned access at TPC[100f970c] dccp_parse_options+0x4f4/0x7e0 [dccp]
Kernel unaligned access at TPC[1011f2e4] ccid3_hc_tx_parse_options+0x1ac/0x380 [dccp_ccid3]
Kernel unaligned access at TPC[100f9898] dccp_parse_options+0x680/0x880 [dccp]

by using the get_unaligned macro for parsing options.

Commiter note: Preserved the sparse __be{16,32} annotations.

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>
2007-10-24 10:46:58 -02:00
Gerrit Renker
5e28599a6e [CCID2]: Sequence number wraparound issues
This replaces several uses of standard arithmetic with the DCCP
sequence number arithmetic functions. The problem here is that the
sequence number wrap-around was not taken into consideration.

 * Condition "seqp->ccid2s_seq <= prev->ccid2s_seq" has been replaced
   by

   	dccp_delta_seqno(seqp->ccid2s_seq, prev->ccid2s_seq) >= 0

   since if seqp is `before' prev, then the delta_seqno() is positive.

 * The test whether sequence numbers `a' and `b' are consecutive has
   the form

   	dccp_delta_seqno(a, b) == 1

 * Increment of ccid2hctx_rpseq could be done using dccp_inc_seqno(),
   but since here the incremented ccid2hctx_rpseq == seqno, used
   assignment instead.

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>
2007-10-10 16:54:35 -07:00
Gerrit Renker
6c58324808 [CCID2]: Remove redundant case block
skb's passed to ccid2_hc_tx_send_packet() are headerless, the packet
type is decided later, in dccp_write_xmit(). Therefore the first test
of the switch/case block is always true, the others are never reached.

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>
2007-10-10 16:54:35 -07:00
Gerrit Renker
ee196c2186 [CCID2]: Remove redundant BUG_ON
This removes a test for `val < 1' which would only have been triggered
when val < 0, due to a preceding test for 0.  Fixed by using an
unsigned type for cwnd (as in TCP) instead.

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>
2007-10-10 16:54:34 -07:00
Gerrit Renker
7d9e8931f9 [CCID2]: Remove ugly BUG_ON
This removes an ugly BUG_ON which has been pointed out by Arnaldo.

Instead of freezing up the machine, a `critical' message is now issued
to the system log.

There is potential of doing this more gracefully (eg. there are a few
internal variables which could be updated despite the lack of memory),
but that requires more complicated changes to the algorithm; thus a
`FIXME' has been added.

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>
2007-10-10 16:54:34 -07:00
Gerrit Renker
cd1f7d347c [CCID2]: Simplify interface
This patch simplifies the interface of ccid2_hc_tx_alloc_seq():

   * ccid2_hc_tx_alloc_seq() is always called with an argument of
     CCID2_SEQBUF_LEN;

   * other code - ccid2_hc_tx_check_sanity() - even depends on the
     assumption that ccid2_hc_tx_alloc_seq() has been called with this
     particular size;

   * passing the `gfp_t' argument to ccid2_hc_tx_alloc_seq() is
     redundant with gfp_any().

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>
2007-10-10 16:54:33 -07:00
Gerrit Renker
042d18f9f3 [DCCP]: Make all `debug' parameters bool
This just sets the parameter to bool, since debugging messages are
either on or off.

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>
2007-10-10 16:54:32 -07:00
Arnaldo Carvalho de Melo
bb293e6a24 [CCID3]: Remove ifdef surrounding BUG_ON
As suggested by DaveM.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
2007-10-10 16:52:45 -07:00
Gerrit Renker
2e86908f7d [CCID3]: Move NULL-protection into function
This moves several instances of testing against NULL into the function which is
used to de-reference the CCID-private data.

Committer note: Made the BUG_ON depend on having CONFIG_IP_DCCP_CCID3_DEBUG, as it
                is too much to have this on production code. Also made sure that
                the macro is used only after checking if sk_state is not LISTEN,
                to make it equivalent to what we had before.

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@ghostprotocols.net>
2007-10-10 16:52:41 -07:00
Gerrit Renker
3393da8241 [DCCP]: Simplify interface of dccp_sample_rtt
The third parameter of dccp_sample_rtt now becomes useless and is removed.

Also combined the subtraction of the timestamp echo and the elapsed time.
This is safe, since (a) presence of timestamp echo is tested first and (b)
elapsed time is either present and non-zero or it is not set and equals 0
due to the memset in dccp_parse_options.

To avoid measuring option-processing time, the timestamp for measuring the
initial Request/Response RTT sample is taken directly when the function is
called (the Linux implementation always adds a timestamp on the Request,
so there is no loss in doing this).

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@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:35 -07:00
Gerrit Renker
aa97efd97a [DCCP]: Reuse ktime_get_real() calls again
This patch reduces the number of timestamps taken in the receive path
for each packet.

The ccid3_hc_tx_update_x() routine is called in
 * the receive path for each CCID3-controlled packet
 * for the nofeedback timer (if no feedback arrives during 4 RTT)

Currently, when there is no loss, each packet gets timestamped twice.
The patch resolves this by recycling the first timestamp taken on packet
reception for RTT sampling.

When the no_feedback_timer() is called, then the timestamp argument is
simply set to NULL - so that ccid3_hc_tx_update_x() takes care of the logic.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:34 -07:00
Arnaldo Carvalho de Melo
0740d49c24 [DCCP] packet_history: Convert dccphtx_tstamp to ktime_t
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:48:15 -07:00
Arnaldo Carvalho de Melo
e7c2335794 [DCCP] packet_history: convert dccphrx_tstamp to ktime_t
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:48:14 -07:00
Arnaldo Carvalho de Melo
668348a423 [DCCP] CCID3: Stop using dccp_timestamp
Now to convert the ackvec code to ktime_t so that we can get rid of
dccp_timestamp and the epoch thing in dccp_sock.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:48:13 -07:00
Arnaldo Carvalho de Melo
9823b7b554 [DCCP]: Convert dccp_sample_rtt to ktime_t
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:48:13 -07:00
Arnaldo Carvalho de Melo
e7a81c6d62 [DCCP]: Convert ccid3hcrx_tstamp_last_feedback to ktime_t
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:48:12 -07:00