linux.git/net/dccp/ccids/lib, branch v2.6.26

dccp ccid-3: X truncated due to type conversion

2008-06-11T10:19:10+00:00

This fixes a bug in computing the inter-packet-interval t_ipi = s/X: 

 scaled_div32(a, b) uses u32 for b, but in "scaled_div32(s, X)" the type of the
 sending rate `X' is u64. Since X is scaled by 2^6, this truncates rates greater
 than 2^26 Bps (~537 Mbps).

Using full 64-bit division now.

Signed-off-by: Gerrit Renker

dccp ccid-3: TFRC reverse-lookup Bug-Fix

2008-06-11T10:19:10+00:00

This fixes a bug in the reverse lookup of p: given a value f(p), instead of p,
the function returned the smallest tabulated value f(p).

The smallest tabulated value of
	 
   10^6 * f(p) =  sqrt(2*p/3) + 12 * sqrt(3*p/8) * (32 * p^3 + p) 

for p=0.0001 is 8172. 

Since this value is scaled by 10^6, the outcome of this bug is that a loss
of 8172/10^6 = 0.8172% was reported whenever the input was below the table
resolution of 0.01%.

This means that the value was over 80 times too high, resulting in large spikes
of the initial loss interval, thus unnecessarily reducing the throughput.

Also corrected the printk format (%u for u32).

Signed-off-by: Gerrit Renker

dccp: Fix sparse warnings

2008-06-11T10:19:09+00:00

This patch fixes the following sparse warnings:
 * nested min(max()) expression:
   net/dccp/ccids/ccid3.c:91:21: warning: symbol '__x' shadows an earlier one
   net/dccp/ccids/ccid3.c:91:21: warning: symbol '__y' shadows an earlier one
   
 * Declaration of function prototypes in .c instead of .h file, resulting in
   "should it be static?" warnings. 

 * Declared "struct dccpw" static (local to dccp_probe).
 
 * Disabled dccp_delayed_ack() - not fully removed due to RFC 4340, 11.3
   ("Receivers SHOULD implement delayed acknowledgement timers ...").

 * Used a different local variable name to avoid
   net/dccp/ackvec.c:293:13: warning: symbol 'state' shadows an earlier one
   net/dccp/ackvec.c:238:33: originally declared here

 * Removed unused functions `dccp_ackvector_print' and `dccp_ackvec_print'.

Signed-off-by: Gerrit Renker

[TFRC]: Remove previous loss intervals implementation

2008-01-28T22:57:20+00:00

Signed-off-by: Gerrit Renker 
Signed-off-by: Ian McDonald 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[CCID3]: Interface CCID3 code with newer Loss Intervals Database

2008-01-28T22:57:20+00:00

This hooks up the TFRC Loss Interval database with CCID 3 packet reception.
In addition, it makes the CCID-specific computation of the first loss
interval (which requires access to all the guts of CCID3) local to ccid3.c.

The patch also fixes an omission in the DCCP code, that of a default /
fallback RTT value (defined in section 3.4 of RFC 4340 as 0.2 sec); while
at it, the  upper bound of 4 seconds for an RTT sample has  been reduced to
match the initial TCP RTO value of 3 seconds from[RFC 1122, 4.2.3.1].

Signed-off-by: Gerrit Renker 
Signed-off-by: Ian McDonald 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[TFRC]: CCID3 (and CCID4) needs to access these inlines

2008-01-28T22:57:19+00:00

This moves two inlines back to packet_history.h: these are not private
to packet_history.c, but are needed by CCID3/4 to detect whether a new
loss is indicated, or whether a loss is already pending.

Signed-off-by: Gerrit Renker 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[TFRC]: Ringbuffer to track loss interval history

2008-01-28T22:57:18+00:00

A ringbuffer-based implementation of loss interval history is easier to
maintain, allocate, and update.

The `swap' routine to keep the RX history sorted is due to and was written
by Arnaldo Carvalho de Melo, simplifying an earlier macro-based variant.

Details:
 * access to the Loss Interval Records via macro wrappers (with safety checks);
 * simplified, on-demand allocation of entries (no extra memory consumption on
   lossless links); cache allocation is local to the module / exported as service;
 * provision of RFC-compliant algorithm to re-compute average loss interval;
 * provision of comprehensive, new loss detection algorithm
 	- support for all cases of loss, including re-ordered/duplicate packets;
 	- waiting for NDUPACK=3 packets to fill the hole;
	- updating loss records when a late-arriving packet fills a hole.

Signed-off-by: Gerrit Renker 
Signed-off-by: Ian McDonald 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[TFRC]: Loss interval code needs the macros/inlines that were moved

2008-01-28T22:57:16+00:00

This moves the inlines (which were previously declared as macros) back into
packet_history.h since the loss detection code needs to be able to read entries
from the RX history in order to create the relevant loss entries: it needs at
least tfrc_rx_hist_loss_prev() and tfrc_rx_hist_last_rcv(), which in turn
require the definition of the other inlines (macros).

Signed-off-by: Gerrit Renker 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[TFRC]: Put RX/TX initialisation into tfrc.c

2008-01-28T22:57:15+00:00

This separates RX/TX initialisation and puts all packet history / loss intervals
initialisation into tfrc.c.
The organisation is uniform: slab declaration -> {rx,tx}_init() -> {rx,tx}_exit()

Signed-off-by: Gerrit Renker 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[TFRC]: The function tfrc_rx_hist_entry_delete() is not used anymore

2008-01-28T22:57:03+00:00

Signed-off-by: Gerrit Renker 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller