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Diffstat (limited to 'util/ratelimit.pl')
| -rw-r--r-- | util/ratelimit.pl | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/util/ratelimit.pl b/util/ratelimit.pl new file mode 100644 index 0000000..e212fa2 --- /dev/null +++ b/util/ratelimit.pl @@ -0,0 +1,159 @@ +#!/usr/bin/perl -wT + +use strict; + +BEGIN { pop @INC if $INC[-1] eq '.' }; + +sub usage () { + print <<END; +usage: ratelimit.pl [options] <period> <regex> <logfile> + +The aim of this script is to compute clients' peak sending rates +from an Exim log file, using the same formula as Exim's ratelimit +ACL condition. This is so that you can get an idea of a reasonable +limit setting before you deploy the restrictions. + +options: + +-d Show debugging information to stderr +-p Show progress of parse the log to stderr + +<period> The smoothing period in seconds, as defined by the + documentation for the ratelimit ACL condition. + + This script isn't perfectly accurate, because the time + stamps in Exim's log files are only accurate to a second + whereas internally Exim computes sender rates to the + accuracy of your computer's clock (typically 10ms). + +<regex> The second argument is a regular expression. + + Each line is matched against the regular expression. + Lines that do not match are ignored. The regex may + contain 0, 1, or 2 () capturing sub-expressions. + + If there are no () sub-expressions, then every line that + matches is used to compute a single rate. Its maximum + value is reported when the script finishes. + + If there is one () sub-expression, then the text matched + by the sub-expression is used to identify a rate lookup + key, similar to the lookup key used by the ratelimit + ACL condition. For example, you might write a regex + to match the client IP address, or the authenticated + username. Separate rates are computed for each different + client and the maximum rate for each client is reported + when the script finishes. + + If there are two () sub-expressions, then the text matched + by the first sub-expression is used to identify a rate + lookup key as above, and the second is used to match the + message size recorded in the log line, e.g. "S=(\\d+)". + In this case the byte rate is computed instead of the + message rate, similar to the per_byte option of the + ratelimit ACL condition. + +<logfile> The log files to be processed can be specified on the + command line after the other arguments; if no filenames + are specified the script will read from stdin. + +examples: + +./ratelimit.pl 1 ' <= .*? \[(.*?)\]' <logfile> + + Compute burst sending rate like ACL condition + ratelimit = 0 / 1s / strict / \$sender_host_address + +./ratelimit.pl 3600 '<= (.*?) ' <logfile> + + Compute sending rate like ACL condition + ratelimit = 0 / 1h / strict / \$sender_address + +END + exit 1; +} + +sub iso2unix (@) { + my ($y,$m,$d,$H,$M,$S,$zs,$zh,$zm) = @_; + use integer; + $y -= $m < 3; + $m += $m < 3 ? 10 : -2; + my $z = defined $zs ? "${zs}1" * ($zh * 60 + $zm) : 0; + my $t = $y/400 - $y/100 + $y/4 + $y*365 + + $m*367/12 + $d - 719499; + return $t * 86400 + + $H * 3600 + + $M * 60 + + $S + - $z; +} + +my $debug = 0; +my $progress = 0; +while (@ARGV && $ARGV[0] =~ /^-\w+$/) { + $debug = 1 if $ARGV[0] =~ s/(-\w*)d(\w*)/$1$2/; + $progress = 1 if $ARGV[0] =~ s/(-\w*)p(\w*)/$1$2/; + shift if $ARGV[0] eq "-"; +} + +usage if @ARGV < 2; + +my $progtime = ""; + +my $period = shift; + +my $re_txt = shift; +my $re = qr{$re_txt}o; + +my %time; +my %rate; +my %max; + +sub debug ($) { + my $key = shift; + printf STDERR "%s\t%12d %8s %5.2f %5.2f\n", + $_, $time{$key}, $key, $max{$key}, $rate{$key}; +} + +while (<>) { + next unless $_ =~ $re; + my $key = $1 || ""; + my $size = $2 || 1.0; + my $time = iso2unix + ($_ =~ m{^(\d{4})-(\d\d)-(\d\d)[ ] + (\d\d):(\d\d):(\d\d)[ ] + (?:([+-])(\d\d)(\d\d)[ ])? + }x); + if ($progress) { + my $prog_now = substr $_, 0, 14; + if ($progtime ne $prog_now) { + $progtime = $prog_now; + print STDERR "$progtime\n"; + } + } + if (not defined $time{$key}) { + $time{$key} = $time; + $rate{$key} = 0.0; + $max{$key} = 0.0; + debug $key if $debug; + next; + } + # see acl_ratelimit() for details of the following + my $interval = $time - $time{$key}; + $interval = 1e-9 if $interval <= 0.0; + my $i_over_p = $interval / $period; + my $a = exp(-$i_over_p); + $time{$key} = $time; + $rate{$key} = $size * (1.0 - $a) / $i_over_p + $a * $rate{$key}; + $max{$key} = $rate{$key} if $rate{$key} > $max{$key}; + debug $key if $debug; +} + +print map { + " " x (20 - length) . + "$_ : $max{$_}\n" +} sort { + $max{$a} <=> $max{$b} +} keys %max; + +# eof |