#!/usr/bin/perl -T -w

# <@LICENSE>
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to you under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at:
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# </@LICENSE>

use strict;
use warnings;
use re 'taint';

my $PREFIX          = '/usr/local';             # substituted at 'make' time
my $DEF_RULES_DIR   = '/usr/local/share/spamassassin';      # substituted at 'make' time
my $LOCAL_RULES_DIR = '/etc/mail/spamassassin';    # substituted at 'make' time
my $LOCAL_STATE_DIR = '/var/lib/spamassassin';    # substituted at 'make' time
use lib '/usr/local/share/perl5';                   # substituted at 'make' time

use Errno qw(EBADF);
use File::Spec;
use Config;

BEGIN {                          # see comments in "spamassassin.raw" for doco
  my @bin = File::Spec->splitpath($0);
  my $bin = ($bin[0] ? File::Spec->catpath(@bin[0..1]) : $bin[1])
            || File::Spec->curdir;

  if (-e $bin.'/lib/Mail/SpamAssassin.pm'
        || !-e '/usr/local/share/perl5/Mail/SpamAssassin.pm' )
  {
    my $searchrelative;
    if ($searchrelative && $bin eq '../' && -e '../blib/lib/Mail/SpamAssassin.pm')
    {
      unshift ( @INC, '../blib/lib' );
    } else {
      foreach ( qw(lib ../lib/site_perl
                ../lib/spamassassin ../share/spamassassin/lib))
      {
        my $dir = File::Spec->catdir( $bin, split ( '/', $_ ) );
        if ( -f File::Spec->catfile( $dir, "Mail", "SpamAssassin.pm" ) )
        { unshift ( @INC, $dir ); last; }
      }
    }
  }
}

use Mail::SpamAssassin;
use Mail::SpamAssassin::Util qw(untaint_var exit_status_str);
use Mail::SpamAssassin::Logger;
use Getopt::Long;
use File::Copy;
use File::Path;
use Pod::Usage;
use Data::Dumper;

use vars qw( %opt );
Mail::SpamAssassin::Util::clean_path_in_taint_mode();
untaint_var( \%ENV );

Getopt::Long::Configure(
  qw(bundling no_getopt_compat
    permute no_auto_abbrev no_ignore_case)
);

GetOptions(
  'list'		=> \$opt{'list'},
  'sudo'		=> \$opt{'sudo'},
  'quiet'               => \$opt{'quiet'},
  'keep-tmps'		=> \$opt{'keep-tmps'},

  'configpath|config-file|config-dir|c|C=s' => \$opt{'configpath'},
  'prefspath|prefs-file|p=s'                => \$opt{'prefspath'},
  'siteconfigpath=s'                        => \$opt{'siteconfigpath'},
  'updatedir=s'                             => \$opt{'updatedir'},
  'cf=s'                                    => \@{$opt{'cf'}},
  'debug|D:s'       => \$opt{'debug'},
  'help|h|?'        => \$opt{'help'},
  'version|V'       => \$opt{'version'},
  )
  or usage( 0, "Unknown option!" );

if ( defined $opt{'help'} ) {
  usage( 0, "For more information read the manual page" );
}
if ( defined $opt{'version'} ) {
  print "SpamAssassin version " . Mail::SpamAssassin::Version() . "\n"
    or die "error writing: $!";
  exit 0;
}

# Check for some dependencies and provide useful error messages if they aren't
# present
eval("use ExtUtils::MakeMaker");
if ($@) {
  print "$0 requires ExtUtils::MakeMaker for proper operation.\n"
    or die "error writing: $!";
  exit 1;
}
unless (qx(re2c -V)) {
  print "$0 requires re2c for proper operation.\n"
    or die "error writing: $!";
  exit 1;
}

sub usage {
  my ( $exitval, $message ) = @_;
  $exitval ||= 64;

  if ($exitval == 0) {
    print_version();
    print("\n")  or die "error writing: $!";
  }
  pod2usage(
    -verbose => 0,
    -message => $message,
    -exitval => $exitval,
  );
}

# set debug areas, if any specified (only useful for command-line tools)
if (defined $opt{'debug'}) {
  $opt{'debug'} ||= 'all';
}

# at least info
$opt{'debug'} ||= 'info';

my $quiet = $opt{'quiet'} || 0;

# ensure the body-rule base extractor plugin is loaded, we use that
my $post_config = q(
  loadplugin Mail::SpamAssassin::Plugin::BodyRuleBaseExtractor

).join("\n", @{$opt{'cf'}})."\n";

my $spamtest = new Mail::SpamAssassin(
  {
    rules_filename      => $opt{'configpath'},
    site_rules_filename => $opt{'siteconfigpath'},
    userprefs_filename  => $opt{'prefspath'},
    debug               => $opt{'debug'},
    local_tests_only    => 1,
    dont_copy_prefs     => 1,
    PREFIX              => $PREFIX,
    DEF_RULES_DIR       => $DEF_RULES_DIR,
    LOCAL_RULES_DIR     => $LOCAL_RULES_DIR,
    LOCAL_STATE_DIR     => $LOCAL_STATE_DIR,
    post_config_text    => $post_config,
  }
);

# appropriate BodyRuleBaseExtractor settings for rule2xs usage
$spamtest->{base_extract} = 1;
$spamtest->{bases_must_be_casei} = 1;
$spamtest->{bases_can_use_alternations} = 0;
$spamtest->{bases_can_use_quantifiers} = 0;
$spamtest->{bases_can_use_char_classes} = 0;
$spamtest->{bases_split_out_alternations} = 1;
$spamtest->{base_quiet} = $quiet;

if (defined $opt{'updatedir'}) {
  $opt{'updatedir'} = Mail::SpamAssassin::Util::untaint_file_path($opt{'updatedir'});
}
else {
  $opt{'updatedir'} = $spamtest->sed_path('__local_state_dir__/compiled/__perl_major_ver__/__version__');
}
my $installdir = $opt{'updatedir'};
if ((!defined $opt{'list'})
        && !$opt{'sudo'}
        && -d $installdir && !-w $installdir)
{
  die "sa-compile: cannot write to $installdir, aborting\n";
}

$spamtest->{bases_cache_dir} = $spamtest->get_and_create_userstate_dir()
                        ."/sa-compile.cache";

$spamtest->init(1);
my $conf = $spamtest->{conf};

# this actually extracts the base rules in the plugin, as a side-effect
my $res = $spamtest->lint_rules();
if ($res) {
  die "sa-compile: not compiling; 'spamassassin --lint' check failed!\n";
}

if ( defined $opt{'list'} ) {
  foreach my $ruletype (sort keys %{$conf->{base_orig}}) {
    print dump_base_strings($ruletype);
  }
}
else {
  compile_base_strings();
}

$spamtest->finish();

# make sure we notice any write errors while flushing output buffer
close STDOUT  or die "error closing STDOUT: $!";
close STDIN   or die "error closing STDIN: $!";

exit;

##############################################################################

sub dump_base_strings {
  my ($ruletype) = @_;

  my $s = "name $ruletype\n";

  foreach my $key1 (sort keys %{$conf->{base_orig}->{$ruletype}}) {
    $s .= "orig $key1 $conf->{base_orig}->{$ruletype}->{$key1}\n";
  }

  foreach my $key (sort keys %{$conf->{base_string}->{$ruletype}}) {
    $s .= "r $key:$conf->{base_string}->{$ruletype}->{$key}\n";
  }
  return $s;
}

##############################################################################

sub dump_as_perl {
  my ($ruletype) = @_;

  my %todump = (
    name => $ruletype,
    base_orig => $conf->{base_orig}->{$ruletype},
    base_string => $conf->{base_string}->{$ruletype}
  );
  my $s = Data::Dumper->Dump([ \%todump ], [qw(bases)]);
  return $s;
}

##############################################################################

sub compile_base_strings {
  my $dirpath = Mail::SpamAssassin::Util::secure_tmpdir();
  die "secure_tmpdir failed" unless $dirpath && -w $dirpath;

  my $sudo = ($opt{sudo} ? 'sudo ' : '');

  foreach my $ruletype (sort keys %{$conf->{base_orig}})
  {
    # create the bases.in file

    my $basespath = "bases_$ruletype.in";
    $basespath =~ s/[^A-Za-z0-9_\.]/_/gs;
    open OUT, ">$dirpath/$basespath"
      or die "cannot create $dirpath/$basespath: $!";
    print OUT dump_base_strings($ruletype)
      or die "error writing to $dirpath/$basespath: $!";
    close OUT
      or die "error closing $dirpath/$basespath: $!";

    # compile it...

    chdir $dirpath  or die "cannot chdir to $dirpath: $!";
    if (!$quiet) { print "cd $dirpath\n"  or die "error writing: $!" }

    rule2xs($basespath);

    my $log = "";
    if ($quiet) {
      $log = ">>$dirpath/log";
      # empty it
      open(ZERO, ">$dirpath/log")  or die "cannot create $dirpath/log: $!";
      close ZERO  or die "error closing $dirpath/log: $!";
    }

    run(get_perl()." Makefile.PL ".
          "PREFIX=$dirpath/ignored INSTALLSITEARCH=$installdir $log");

    run("make $log");
    run($sudo."make install $log");	# into $installdir

    # and generate the bases.pl file, for perl consumers

    my $plpath = "bases_$ruletype.pl";
    $plpath =~ s/[^A-Za-z0-9_\.]/_/gs;
    open(OUT, ">$dirpath/$plpath")
      or die "cannot create $dirpath/$plpath: $!";
    print OUT dump_as_perl($ruletype)
      or die "error writing to $dirpath/$plpath: $!";
    close OUT
      or die "error closing $dirpath/$plpath: $!";

    run($sudo."cp $dirpath/$plpath $installdir/$plpath");
  }

  if (!$opt{'keep-tmps'}) {
    chdir '/'; 
    if (!$quiet) {
      # saves trouble on MacOS, possibly
      print "cd /\n"  or die "error writing: $!";
    }
    run($sudo."rm -rf $dirpath");       # cleanup
  }
  else {
    print "temporary dir left due to --keep-tmps: $dirpath\n"
      or die "error writing: $!";
  }
}

sub run {
  my @cmd = @_;
  if (!$quiet) { print join(' ',@cmd)."\n"  or die "error writing: $!" }
  if (system(@cmd) != 0) {
    my $msg = $? == -1 ? "failed to execute: $!"
                       : "failed: ".exit_status_str($?);
    if (!$quiet) { die "command ".$msg."\n" }
    else { die "command '".join(' ',@cmd)."' ".$msg."\n" }
    return 0;
  }
  return 1;
}

sub get_perl {
  my $perl;
  if ($^X =~ m|^/|) {
    $perl = $^X;
  } else {
    use Config;
    $perl = $Config{perlpath};
    $perl =~ s|/[^/]*$|/$^X|;
  }
  return untaint_var($perl);
}

##############################################################################

use constant MAX_RULES_PER_C_FILE => 200;

sub rule2xs {
  my $modname;
  my $force = 1;
  my $FILE = shift;

  if (!$quiet) { print "reading $FILE\n" or die "error writing: $!" }
  open(my $fh, $FILE)  or die "cannot open $FILE: $!";
# read ruleset name from the first line in the file
  my $ruleset_name;
  $_ = <$fh>;
  defined $_  or die "error reading $FILE: $!";
  local ($1);
  if (/^name\s+(\S+)/) {
    $ruleset_name = untaint_var($1);
  }

  if (!$modname) {
    $modname = "Mail::SpamAssassin::CompiledRegexps::$ruleset_name";
  }

  our $PATH = $modname;
  $PATH =~ s/::/-/g;
  $PATH =~ s/[^-_A-Za-z0-9\.]/_/g;
  our $PMFILE = $modname;
  $PMFILE =~ s/.*:://;
  $PMFILE .= ".pm";
  our $XSFILE = $PMFILE;
  $XSFILE =~ s/\.pm$/.xs/;

  $force and system("rm -rf $PATH");
  mkdir $PATH or (!$force and die "mkdir($PATH): $!");
  chdir $PATH;
  if (!$quiet) { print "cd $PATH\n" or die "error writing: $!" }

  my $cprefix = $modname; $cprefix =~ s/[^A-ZA-z0-9]+/_/gs;

  my $numscans = 0;
  my $has_rules = '';

  while (!eof($fh)) {
    $numscans++;

    open(my $re, ">scanner${numscans}.re")
      or die "cannot create scanner${numscans}.re: $!";

    print $re <<EOT  or die "error writing: $!";
#define NULL            ((char*) 0)
#define YYCTYPE         unsigned char
#define YYCURSOR        *p
#define YYLIMIT         *p
#define YYMARKER        q
#define YYFILL(n)

/* backtrack to return other, semi-overlapped tokens; e.g.
   allow "abcdef" to return both "abc" and "cde" as tokens */
#define RET(x)          { YYCURSOR = YYMARKER; return (x); }
EOT

    print $re <<EOT  or die "error writing: $!";
char *${cprefix}_scan${numscans}(unsigned char **p){
unsigned char *q = 1 + *p;
/*!re2c
EOT

    my $line = 0;
    my $rulecount = 0;
    for ($!=0; <$fh>; $!=0) {
      next if /^#/;

      local ($1,$2);
      if (/^orig\s+(\S+)\s+(.*)$/) {
	my $name = $1;
	my $regexp = $2;
	$name =~ s/#/[hash]/gs;
	$regexp =~ s/#/[hash]/gs;
	$has_rules .= "  q#$name# => q#$regexp#,\n";
        $rulecount++;
	next;
      }

      my ($regexp, $reason) = /^r (.*):(.*)$/;
      die "no 'r REGEXP:REASON' in $_" unless defined $regexp;

      eval {
	print $re "\t",
          Mail::SpamAssassin::Plugin::BodyRuleBaseExtractor::fixup_re($regexp),
          "            {RET(\"$reason\");}\n"
          or die "error writing: $!";
	$line++; 1;
      } or do {
        my $eval_stat = $@ ne '' ? $@ : "errno=$!";  chomp $eval_stat;
        handle_fixup_error($eval_stat, $regexp, $reason);
      };
      last if $line == MAX_RULES_PER_C_FILE;
    }
    defined $_ || $!==0  or
      $!==EBADF ? dbg("error reading from $FILE: $!")
                : die "error reading from $FILE: $!";

    print $re <<EOT  or die "error writing: $!";
  [\\000-\\377]        { return NULL; }
*/
}
EOT

  }

  for (1..$numscans) {
    my $cmd = "re2c -i -b -o scanner$_.c scanner$_.re";
    if (!run($cmd)) {
      # this must be fatal; it can result in corrupt output modules missing
      # scannerN() functions
      my $cwd = `pwd`; chop $cwd;
      die "'$cmd' failed, dying!\n".
          "Have you got a sufficiently-recent version of re2c?\n".
	  "see $cwd/scanner$_.re\n";
    }
  }

  my $ccopt = $Config{optimize};      # typically "-O2"

  open(FILE, ">Makefile.PL")  or die "cannot create Makefile.PL: $!";
  print FILE <<"EOT"  or die "error writing to Makefile.PL: $!";
    use ExtUtils::MakeMaker;

    WriteMakefile(
	'NAME' => '$modname',
	'VERSION_FROM' => '$PMFILE',
	'ABSTRACT_FROM' => '$PMFILE',
	'OBJECT' => '\$(O_FILES)',
	'OPTIMIZE' => '$ccopt',
	'AUTHOR' => 'A. U. Tomated <automated\@example.com>',
    );
EOT
  close FILE  or die "error closing Makefile.PL: $!";

  open(FILE, ">MANIFEST.SKIP")  or die "cannot create MANIFEST.SKIP: $!";
  print FILE <<'EOT'  or die "error writing to MANIFEST.SKIP: $!";
CVS/.*
\.bak$
\.sw[a-z]$
\.tar$
\.tgz$
\.tar\.gz$
\.o$
\.xsi$
\.bs$
^.#
^tmp/
^blib/
^Makefile$
^Makefile\.[a-z]+$
^pm_to_blib$
~$
EOT
  close FILE  or die "error closing MANIFEST.SKIP: $!";

  open(my $re, ">$XSFILE")  or die "cannot create $XSFILE: $!";
  print $re <<"EOT"  or die "error writing to $XSFILE: $!";
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

  /* bug 5556: newSVpvn_share() is not a defined API in perl 5.6.x.
   * Thankfully we can use newSVpvn() without much harm, losing only
   * a tiny bit of performance (I'd reckon ;).
   */
#ifdef newSVpvn_share
#define my_newSVpvn_share(x,y,z)    newSVpvn_share(x,y,z)
#else
#define my_newSVpvn_share(x,y,z)    newSVpvn(x,y)
#endif

  /* split single-space-separated result string */
  static void
  split_and_add (AV *results, char *match)
  {
      char *wordstart, *cp;

      for (cp = wordstart = match; *cp != (unsigned char) 0; cp++) {
	if (*cp == ' ') {
	  av_push(results,
	      my_newSVpvn_share(wordstart, cp-wordstart, (U32)0));
	  wordstart = cp + 1;
	}
      }
      av_push(results,
	      my_newSVpvn_share(wordstart, cp-wordstart, (U32)0));
  }

EOT

  # use a buffer string here instead of writing direct to the file,
  # so we can prepend 'extern' statements (bug 5534)
  my $xscode = <<"EOT";

MODULE = $modname  PACKAGE = $modname

PROTOTYPES: DISABLE

SV *
scan(psv)
	SV* psv

  PREINIT:
	char *match;
	unsigned char *cursor;
	unsigned char *pstart;
	unsigned char *pend;
	STRLEN plen;
	AV *results;

  CODE:
	pstart = (unsigned char *) SvPVutf8(psv, plen);
	pend = pstart + plen;
	results = (AV *) sv_2mortal((SV *) newAV());

EOT

  for (1..$numscans) {
    my $funcname = $cprefix."_scan".$_;

    $xscode =
        # prepend this chunk
        qq{

	  extern char *${funcname} (unsigned char **);

        }.$xscode.
        # and append this one
        qq{

	  cursor = pstart;
	  while (cursor < pend) {
	    while ((match = ${funcname} (\&cursor)) != NULL) {
	      split_and_add(results, match);
	    }
	  }

        };

  }

  print $re $xscode  or die "error writing: $!";
  print $re <<EOT  or die "error writing: $!";;
	  RETVAL = newRV((SV *) results);
      OUTPUT:
	  RETVAL

EOT

  close($re)  or die "error closing $XSFILE: $!";

  open(FILE, ">$PMFILE")  or die "cannot create $PMFILE: $!";
  my $str =<<"EOT";

package $modname;

use strict;
use vars qw(\$VERSION \@ISA \@EXPORT_OK);

use XSLoader ();

BEGIN {
\$VERSION = '1.0';
\@ISA = qw(XSLoader);
\@EXPORT_OK = qw();

our \$HAS_RULES = {
  $has_rules
};

XSLoader::load '$modname', \$VERSION;
}

1;
fnord__END__

fnord=head1 NAME

$modname - Efficient string matching for regexps found in $FILE

fnord=head1 SYNOPSIS

  use $modname;
  
  ...
  my \$match = ${modname}::scan(\$string);

fnord=head1 DESCRIPTION

This module was created by SpamAssassin with the aid of re2xs, which uses re2c
to create an XS library capable of scanning through a bunch of regular
expressions as defined in F<$FILE>.

See C<sa-compile> for more details.

fnord=cut
EOT

  $str =~ s/^fnord//gm;
  print FILE $str  or die "error writing to $PMFILE: $!";
  close FILE  or die "error closing $PMFILE: $!";
}

sub handle_fixup_error {
  my ($strat, $regexp, $reason) = @_;
  if ($strat) {
    warn "skipped: $regexp: $strat";
  }
}

##############################################################################

=head1 NAME

sa-compile - compile SpamAssassin ruleset into native code

=head1 SYNOPSIS

B<sa-compile> [options]

Options:

  --list                        Output base string list to STDOUT
  --sudo                        Use 'sudo' for privilege escalation
  --keep-tmps                   Keep temporary files instead of deleting
  -C path, --configpath=path, --config-file=path
                                Path to standard configuration dir
  -p prefs, --prefspath=file, --prefs-file=file
                                Set user preferences file
  --siteconfigpath=path         Path for site configs
                                (default: /etc/mail/spamassassin)
  --updatedir=path              Directory to place updates
          (default: /var/lib/spamassassin/compiled/<perlversion>/3.004001)
  --cf='config line'            Additional line of configuration
  -D, --debug [area=n,...]	Print debugging messages
  -V, --version			Print version
  -h, --help			Print usage message

=head1 DESCRIPTION

sa-compile uses C<re2c> to compile the site-wide parts of the SpamAssassin
ruleset. No part of user_prefs or any files included from user_prefs can be
built into the compiled set.

This compiled set is then used by the 
C<Mail::SpamAssassin::Plugin::Rule2XSBody> plugin to speed up
SpamAssassin's operation, where possible, and when that plugin is loaded.

C<re2c> can match strings much faster than perl code, by constructing a DFA to
match many simple strings in parallel, and compiling that to native object
code.  Not all SpamAssassin rules are amenable to this conversion, however.

This requires C<re2c> (see C<http://re2c.org/>), and the C
compiler used to build Perl XS modules, be installed.

Note that running this, and creating a compiled ruleset, will have no
effect on SpamAssassin scanning speeds unless you also edit your C<v320.pre>
file and ensure this line is uncommented:

  loadplugin Mail::SpamAssassin::Plugin::Rule2XSBody

Additionally, "sa-compile" will not restart "spamd" or otherwise cause a scanner to
reload the now-compiled ruleset automatically.

=head1 OPTIONS

=over 4

=item B<--list>

Output the extracted base strings to STDOUT, instead of generating
the C extension code.

=item B<--sudo>

Use C<sudo(8)> to run code as 'root' when writing files to the compiled-rules
storage area (which is C</var/lib/spamassassin/compiled/5.016/3.004001> by default).

=item B<--quiet>

Produce less diagnostic output.  Errors will still be displayed.

=item B<--keep-tmps>

Keep temporary files after the script completes, instead of
deleting them.

=item B<-C> I<path>, B<--configpath>=I<path>, B<--config-file>=I<path>

Use the specified path for locating the distributed configuration files.
Ignore the default directories (usually C</usr/share/spamassassin> or similar).

=item B<--siteconfigpath>=I<path>

Use the specified path for locating site-specific configuration files.  Ignore
the default directories (usually C</etc/mail/spamassassin> or similar).

=item B<--updatedir>

By default, C<sa-compile> will use the system-wide rules update directory:

        /var/lib/spamassassin/compiled/5.016/3.004001

If the updates should be stored in another location, specify it here.

Note that use of this option is not recommended; if sa-compile is placing the
compiled rules the wrong directory, you probably need to rebuild SpamAssassin
with different C<Makefile.PL> arguments, instead of overriding sa-compile's
runtime behaviour.

=item B<--cf='config line'>

Add additional lines of configuration directly from the command-line, parsed
after the configuration files are read.   Multiple B<--cf> arguments can be
used, and each will be considered a separate line of configuration.

=item B<-p> I<prefs>, B<--prefspath>=I<prefs>, B<--prefs-file>=I<prefs>

Read user score preferences from I<prefs> (usually
C<$HOME/.spamassassin/user_prefs>) .

=item B<-D> [I<area,...>], B<--debug> [I<area,...>]

Produce debugging output.  If no areas are listed, all debugging information is
printed.  Diagnostic output can also be enabled for each area individually;
I<area> is the area of the code to instrument.

For more information about which areas (also known as channels) are
available, please see the documentation at
L<http://wiki.apache.org/spamassassin/DebugChannels>.

=item B<-h>, B<--help>

Print help message and exit.

=item B<-V>, B<--version>

Print sa-compile version and exit.

=back

=head1 SEE ALSO

Mail::SpamAssassin(3)
spamassassin(1)
spamd(1)

=head1 PREREQUESITES

C<Mail::SpamAssassin>
C<re2c>
C<Mail::SpamAssassin::Plugin::Rule2XSBody>

=head1 BUGS

See <http://issues.apache.org/SpamAssassin/>

=head1 AUTHORS

The Apache SpamAssassin(tm) Project <http://spamassassin.apache.org/>

=head1 COPYRIGHT

SpamAssassin is distributed under the Apache License, Version 2.0, as
described in the file C<LICENSE> included with the distribution.

=cut