From: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Date: Thu, 4 Sep 2008 05:30:19 +0000 (+0200)
Subject: dccp tfrc/ccid-3: Computing Loss Rate from Loss Event Rate
X-Git-Tag: v2.6.28-rc1~717^2~305^2~49
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=535c55df136ad2783d444e54d518a8fae8bdbf79;p=pandora-kernel.git

dccp tfrc/ccid-3: Computing Loss Rate from Loss Event Rate

This adds a function to take care of the following cases occurring in the
computation of the Loss Rate p:

 * 1/(2^32-1) is mapped into 0% as per RFC 4342, 8.5;
 * 1/0        is mapped into the maximum of 100%;
 * we want to avoid that p = 1/x is rounded down to 0 when x is very large,
   since this means accidentally re-entering slow-start (indicated by p==0).

In the last case, the minimum-resolution value of p is returned.

Furthermore, a bug in ccid3_hc_rx_getsockopt is fixed (1/0 was mapped into ~0U),
which now allows to consistently print the scaled p-values as

        printf("Loss Event Rate = %u.%04u %%\n", rx_info.tfrcrx_p / 10000,
                                                 rx_info.tfrcrx_p % 10000);

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
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