Commit Graph

46 Commits

Author SHA1 Message Date
Gerrit Renker 84a97b0af8 [CCID]: More informative registration
The patch makes the registration messages of CCID 2/3 a bit more
informative: instead of repeating the CCID number as currently done,

        "CCID: Registered CCID 2 (ccid2)"  or
        "CCID: Registered CCID 3 (ccid3)",

the descriptive names of the CCID's (from RFCs) are now used:

	"CCID: Registered CCID 2 (TCP-like)" and
	"CCID: Registered CCID 3 (TCP-Friendly Rate Control)".

To allow spaces in the name, the slab name string has been changed to
refer to the numeric CCID identifier, using the same format as 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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:57:58 -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
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
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 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
Gerrit Renker 39dad26c37 [DCCP]: Allocation in atomic context
This fixes the following bug reported in syslog:

[ 4039.051658] BUG: sleeping function called from invalid context at /usr/src/davem-2.6/mm/slab.c:3032
[ 4039.051668] in_atomic():1, irqs_disabled():0
[ 4039.051670] INFO: lockdep is turned off.
[ 4039.051674]  [<c0104c0f>] show_trace_log_lvl+0x1a/0x30
[ 4039.051687]  [<c0104d4d>] show_trace+0x12/0x14
[ 4039.051691]  [<c0104d65>] dump_stack+0x16/0x18
[ 4039.051695]  [<c011371e>] __might_sleep+0xaf/0xbe
[ 4039.051700]  [<c0157b66>] __kmalloc+0xb1/0xd0
[ 4039.051706]  [<f090416f>] ccid2_hc_tx_alloc_seq+0x35/0xc3 [dccp_ccid2]
[ 4039.051717]  [<f09048d6>] ccid2_hc_tx_packet_sent+0x27f/0x2d9 [dccp_ccid2]
[ 4039.051723]  [<f085486b>] dccp_write_xmit+0x1eb/0x338 [dccp]
[ 4039.051741]  [<f085603d>] dccp_sendmsg+0x113/0x18f [dccp]
[ 4039.051750]  [<c03907fc>] inet_sendmsg+0x2e/0x4c
[ 4039.051758]  [<c033a47d>] sock_aio_write+0xd5/0x107
[ 4039.051766]  [<c015abc1>] do_sync_write+0xcd/0x11c
[ 4039.051772]  [<c015b296>] vfs_write+0x118/0x11f
[ 4039.051840]  [<c015b932>] sys_write+0x3d/0x64
[ 4039.051845]  [<c0103e7c>] syscall_call+0x7/0xb
[ 4039.051848]  =======================

The problem was that GFP_KERNEL was used; fixed by using gfp_any().

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>
2007-08-21 20:58:06 -07:00
YOSHIFUJI Hideaki c9eaf17341 [NET] DCCP: Fix whitespace errors.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-10 23:19:27 -08:00
Arnaldo Carvalho de Melo 8109b02b53 [DCCP]: Whitespace cleanups
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>
2006-12-11 14:35:00 -08:00
Gerrit Renker 6b57c93dc3 [DCCP]: Use `unsigned' for packet lengths
This patch implements a suggestion by Ian McDonald and

 1) Avoids tests against negative packet lengths by using unsigned int
    for packet payload lengths in the CCID send_packet()/packet_sent() routines

 2) As a consequence, it removes an now unnecessary test with regard to `len > 0'
    in ccid3_hc_tx_packet_sent: that condition is always true, since
      * negative packet lengths are avoided
      * ccid3_hc_tx_send_packet flags an error whenever the payload length is 0.
        As a consequence, ccid3_hc_tx_packet_sent is never called as all errors
        returned by ccid_hc_tx_send_packet are caught in dccp_write_xmit

 3) Removes the third argument of ccid_hc_tx_send_packet (the `len' parameter),
    since it is currently always set to skb->len. The code is updated with regard
    to this parameter change.

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@mandriva.com>
2006-12-02 21:31:02 -08:00
Gerrit Renker 59348b19ef [DCCP]: Simplified conditions due to use of enum:8 states
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>
2006-12-02 21:24:38 -08:00
Gerrit Renker 84116716cc [DCCP]: enable debug messages also for static builds
This patch
  * makes debugging (when configured) work both for static / module build
  * provides generic debugging macros for use in other DCCP / CCID modules
  * adds missing information about debug parameters to Kconfig
  * performs some code tidy-up

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02 21:24:35 -08:00
Andrea Bittau 32aac18dfa [DCCP] CCID2: Code optimizations
These are code optimizations which are relevant when dealing with large
windows.  They are not coded the way I would like to, but they do the job for
the short-term.  This patch should be more neat.

Commiter note: Changed the seqno comparisions to use {after,before}48 to handle
               wrapping.

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02 21:23:52 -08:00
Randy Dunlap 234af48401 [DCCP]: fix printk format warnings
Fix printk format warnings:
build2.out:net/dccp/ccids/ccid2.c:355: warning: long long unsigned int format, u64 arg (arg 3)
build2.out:net/dccp/ccids/ccid2.c:360: warning: long long unsigned int format, u64 arg (arg 3)
build2.out:net/dccp/ccids/ccid2.c:482: warning: long long unsigned int format, u64 arg (arg 5)
build2.out:net/dccp/ccids/ccid2.c:639: warning: long long unsigned int format, u64 arg (arg 3)
build2.out:net/dccp/ccids/ccid2.c:639: warning: long long unsigned int format, u64 arg (arg 4)
build2.out:net/dccp/ccids/ccid2.c:674: warning: long long unsigned int format, u64 arg (arg 3)
build2.out:net/dccp/ccids/ccid2.c:720: warning: long long unsigned int format, u64 arg (arg 3)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-30 15:24:37 -08:00
Gerrit Renker 0e64e94e47 [DCCP]: Update documentation references.
Updates the references to spec documents throughout the code, taking into
account that

* the DCCP, CCID 2, and CCID 3 drafts all became RFCs in March this year

* RFC 1063 was obsoleted by RFC 1191

* draft-ietf-tcpimpl-pmtud-0x.txt was published as an Informational
  RFC, RFC 2923 on 2000-09-22.

All references verified.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-24 16:17:51 -07:00
Ian McDonald 3dd9a7c3a1 [DCCP]: Use constants for CCIDs
With constants for CCID numbers this now uses them in some places.

Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-09-24 18:03:41 -03:00
Andrea Bittau 593f16aa62 [DCCP] CCID2: Add helper functions for changing important CCID2 state
Introduce methods which manipulate interesting congestion control
state such as pipe and rtt estimate.  This is useful for people
wishing to monitor the variables of CCID and instrument the code
[perhaps using Kprobes].  Personally, I am a fan of
encapsulation---that justifies this change =D.

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>
2006-09-22 15:19:42 -07:00
Andrea Bittau 374bcf32c8 [DCCP] CCID2: Halve cwnd once upon multiple losses in a single RTT
When multiple losses occur in one RTT, the window should be halved
only once [a single "congestion event"].  This is now implemented,
although not perfectly.  Slightly changed the interface for changing
the cwnd: pass hctx instead of dp.  This is required in order to allow
for change_cwnd to be called from _init().

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>
2006-09-22 15:19:41 -07:00
Andrea Bittau 07978aabd5 [DCCP] CCID2: Allocate seq records on demand
Allocate more sequence state on demand.  Each time a packet is sent
out by CCID2, a record of it needs to be kept.  This list of records
grows proportionally to cwnd.  Previously, the length of this list was
hardcored and therefore the cwnd could only grow to this value (of
128).  Now, records are allocated on demand as necessary---cwnd may
grow as it wishes.  The exceptional case of when memory is not
available is not handled gracefully.  Perhaps, cwnd should be capped
at that point.

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>
2006-09-22 15:19:40 -07:00
Andrea Bittau 8d424f6ca2 [DCCP] CCID2: Add Kconfig option for CCID2 debug
Allow the user to choose whether or not to enable CCID2 debugging via
Kconfig.

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>
2006-09-22 15:19:39 -07:00
Andrea Bittau 446dec30c7 [DCCP] CCID2: Tell DCCP to quickly check whether cwnd is available
If not enough cwnd is available, tell the sender to check again as
soon as possible.  This will increase CPU utilization (polling
frequently for cwnd) but will improve network performance.  That is,
the sender will need to wait less before detecting the increase of
cwnd.  A better architecture would be for the CCID to call-back (or
dequeue) from DCCP when it is able to transmit traffic -- not the
other way around as it currently occurs.

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>
2006-09-22 15:19:39 -07:00
Andrea Bittau d458c25ce2 [DCCP] CCID2: Initialize ssthresh to infinity
Initialize the slow-start threshold to infinity.  This way, upon connection
initiation, slow-start will be exited only upon a packet loss.  This patch will
allow connections to quickly gain speed.

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>
2006-09-22 15:19:11 -07:00
Andrea Bittau 29651cda97 [DCCP] CCID2: Fix jiffie wrap issues
Jiffies are now handled correctly (I hope) in CCID2.  If they wrap, no
problem.

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>
2006-09-22 15:19:10 -07:00
Andrea Bittau 8e27e4650c [DCCP] ackvec: Fix how DCCP_ACKVEC_STATE_NOT_RECEIVED is used
Fix the way state is masked out.  DCCP_ACKVEC_STATE_NOT_RECEIVED is
defined as appears in the packet, therefore bit shifting is not
required.  This fix allows CCID2 to correctly detect losses.

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>
2006-09-22 15:19:08 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Arnaldo Carvalho de Melo c0c736db7e [DCCP] ccid2: coding style cleanups
No changes in the logic where made.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 22:05:37 -08:00
Arnaldo Carvalho de Melo 91f0ebf7b6 [DCCP] CCID: Improve CCID infrastructure
1. No need for ->ccid_init nor ->ccid_exit, this is what module_{init,exit}
   does and anynways neither ccid2 nor ccid3 were using it.

2. Rename struct ccid to struct ccid_operations and introduce struct ccid
   with a pointer to ccid_operations and rigth after it the rx or tx
   private state.

3. Remove the pointer to the state of the half connections from struct
   dccp_sock, now its derived thru ccid_priv() from the ccid pointer.

Now we also can implement the setsockopt for changing the CCID easily as
no ccid init routines can affect struct dccp_sock in any way that prevents
other CCIDs from working if a CCID switch operation is asked by apps.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 19:21:44 -08:00
Andrea Bittau 77ff72d528 [DCCP] CCID2: Drop sock reference count on timer expiration and reset.
There was a hybrid use of standard timers and sk_timers.  This caused
the reference count of the sock to be incorrect when resetting the RTO
timer.  The sock reference count should now be correct, enabling its
destruction, and allowing the DCCP module to be unloaded.

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-03-20 17:57:52 -08:00
Andrea Bittau 2a91aa3967 [DCCP] CCID2: Initial CCID2 (TCP-Like) implementation
Original work by Andrea Bittau, Arnaldo Melo cleaned up and fixed several
issues on the merge process.

For now CCID2 was turned the default for all SOCK_DCCP connections, but this
will be remedied soon with the merge of the feature negotiation code.

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>
2006-03-20 17:41:47 -08:00