# Copyright (C) 2016-2020 all contributors
# License: AGPL-3.0+
#
# ref: https://cr.yp.to/proto/maildir.html
# http://wiki2.dovecot.org/MailboxFormat/Maildir
package PublicInbox::WatchMaildir;
use strict;
use warnings;
use PublicInbox::Eml;
use PublicInbox::InboxWritable;
use File::Temp 0.19 (); # 0.19 for ->newdir
use PublicInbox::Filter::Base qw(REJECT);
use PublicInbox::Spamcheck;
*mime_from_path = \&PublicInbox::InboxWritable::mime_from_path;
sub new {
my ($class, $config) = @_;
my (%mdmap, @mdir, $spamc);
my %uniq;
# "publicinboxwatch" is the documented namespace
# "publicinboxlearn" is legacy but may be supported
# indefinitely...
foreach my $pfx (qw(publicinboxwatch publicinboxlearn)) {
my $k = "$pfx.watchspam";
defined(my $dirs = $config->{$k}) or next;
$dirs = [ $dirs ] if !ref($dirs);
for my $dir (@$dirs) {
if (is_maildir($dir)) {
# skip "new", no MUA has seen it, yet.
my $cur = "$dir/cur";
my $old = $mdmap{$cur};
if (ref($old)) {
foreach my $ibx (@$old) {
warn <<"";
"$cur already watched for `$ibx->{name}'
}
die;
}
push @mdir, $cur;
$uniq{$cur}++;
$mdmap{$cur} = 'watchspam';
} else {
warn "unsupported $k=$dir\n";
}
}
}
my $k = 'publicinboxwatch.spamcheck';
my $default = undef;
my $spamcheck = PublicInbox::Spamcheck::get($config, $k, $default);
$spamcheck = _spamcheck_cb($spamcheck) if $spamcheck;
$config->each_inbox(sub {
# need to make all inboxes writable for spam removal:
my $ibx = $_[0] = PublicInbox::InboxWritable->new($_[0]);
my $watch = $ibx->{watch} or return;
if (is_maildir($watch)) {
my $watch_hdrs = [];
if (my $whs = $ibx->{watchheader}) {
for (@$whs) {
my ($k, $v) = split(/:/, $_, 2);
# XXX should this be case-insensitive?
# Or, mutt-style, case-sensitive iff
# a capital letter exists?
push @$watch_hdrs, [ $k, qr/\Q$v\E/ ];
}
}
if (my $list_ids = $ibx->{listid}) {
for (@$list_ids) {
# RFC2919 section 6 stipulates
# "case insensitive equality"
my $re = qr/<[ \t]*\Q$_\E[ \t]*>/i;
push @$watch_hdrs, ['List-Id', $re ];
}
}
if (scalar @$watch_hdrs) {
$ibx->{-watchheaders} = $watch_hdrs;
}
my $new = "$watch/new";
my $cur = "$watch/cur";
push @mdir, $new unless $uniq{$new}++;
push @mdir, $cur unless $uniq{$cur}++;
push @{$mdmap{$new} ||= []}, $ibx;
push @{$mdmap{$cur} ||= []}, $ibx;
} else {
warn "watch unsupported: $k=$watch\n";
}
});
return unless @mdir;
my $mdre = join('|', map { quotemeta($_) } @mdir);
$mdre = qr!\A($mdre)/!;
bless {
spamcheck => $spamcheck,
mdmap => \%mdmap,
mdir => \@mdir,
mdre => $mdre,
config => $config,
importers => {},
opendirs => {}, # dirname => dirhandle (in progress scans)
}, $class;
}
sub _done_for_now {
my ($self) = @_;
my $importers = $self->{importers};
foreach my $im (values %$importers) {
$im->done;
}
}
sub _try_fsn_paths {
my ($self, $scan_re, $paths) = @_;
foreach (@$paths) {
my $path = $_->{path};
if ($path =~ $scan_re) {
scan($self, $path);
} else {
_try_path($self, $path);
}
}
_done_for_now($self);
}
sub _remove_spam {
my ($self, $path) = @_;
# path must be marked as (S)een
$path =~ /:2,[A-R]*S[T-Za-z]*\z/ or return;
my $mime = mime_from_path($path) or return;
$self->{config}->each_inbox(sub {
my ($ibx) = @_;
eval {
my $im = _importer_for($self, $ibx);
$im->remove($mime, 'spam');
if (my $scrub = $ibx->filter($im)) {
my $scrubbed = $scrub->scrub($mime, 1);
$scrubbed or return;
$scrubbed == REJECT() and return;
$im->remove($scrubbed, 'spam');
}
};
if ($@) {
warn "error removing spam at: ", $path,
" from ", $ibx->{name}, ': ', $@, "\n";
}
})
}
sub _try_path {
my ($self, $path) = @_;
return unless PublicInbox::InboxWritable::is_maildir_path($path);
if ($path !~ $self->{mdre}) {
warn "unrecognized path: $path\n";
return;
}
my $inboxes = $self->{mdmap}->{$1};
unless ($inboxes) {
warn "unmappable dir: $1\n";
return;
}
if (!ref($inboxes) && $inboxes eq 'watchspam') {
return _remove_spam($self, $path);
}
my $warn_cb = $SIG{__WARN__} || sub { print STDERR @_ };
local $SIG{__WARN__} = sub {
$warn_cb->("path: $path\n");
$warn_cb->(@_);
};
foreach my $ibx (@$inboxes) {
my $mime = mime_from_path($path) or next;
my $im = _importer_for($self, $ibx);
# any header match means it's eligible for the inbox:
if (my $watch_hdrs = $ibx->{-watchheaders}) {
my $ok;
my $hdr = $mime->header_obj;
for my $wh (@$watch_hdrs) {
my @v = $hdr->header_raw($wh->[0]);
$ok = grep(/$wh->[1]/, @v) and last;
}
next unless $ok;
}
if (my $scrub = $ibx->filter($im)) {
my $ret = $scrub->scrub($mime) or next;
$ret == REJECT() and next;
$mime = $ret;
}
$im->add($mime, $self->{spamcheck});
}
}
sub quit { trigger_scan($_[0], 'quit') }
sub watch {
my ($self) = @_;
my $scan = File::Temp->newdir("public-inbox-watch.$$.scan.XXXXXX",
TMPDIR => 1);
my $scandir = $self->{scandir} = $scan->dirname;
my $re = qr!\A$scandir/!;
my $cb = sub { _try_fsn_paths($self, $re, \@_) };
# lazy load here, we may support watching via IMAP IDLE
# in the future...
eval { require Filesys::Notify::Simple } or
die "Filesys::Notify::Simple is currently required for $0\n";
my $fsn = Filesys::Notify::Simple->new([@{$self->{mdir}}, $scandir]);
$fsn->wait($cb) until $self->{quit};
}
sub trigger_scan {
my ($self, $base) = @_;
my $dir = $self->{scandir} or return;
open my $fh, '>', "$dir/$base" or die "open $dir/$base failed: $!\n";
close $fh or die "close $dir/$base failed: $!\n";
}
sub scan {
my ($self, $path) = @_;
if ($path =~ /quit\z/) {
%{$self->{opendirs}} = ();
_done_for_now($self);
delete $self->{scandir};
$self->{quit} = 1;
return;
}
# else: $path =~ /(cont|full)\z/
return if $self->{quit};
my $max = 10;
my $opendirs = $self->{opendirs};
my @dirnames = keys %$opendirs;
foreach my $dir (@dirnames) {
my $dh = delete $opendirs->{$dir};
my $n = $max;
while (my $fn = readdir($dh)) {
_try_path($self, "$dir/$fn");
last if --$n < 0;
}
$opendirs->{$dir} = $dh if $n < 0;
}
if ($path =~ /full\z/) {
foreach my $dir (@{$self->{mdir}}) {
next if $opendirs->{$dir}; # already in progress
my $ok = opendir(my $dh, $dir);
unless ($ok) {
warn "failed to open $dir: $!\n";
next;
}
my $n = $max;
while (my $fn = readdir($dh)) {
_try_path($self, "$dir/$fn");
last if --$n < 0;
}
$opendirs->{$dir} = $dh if $n < 0;
}
}
_done_for_now($self);
# do we have more work to do?
trigger_scan($self, 'cont') if keys %$opendirs;
}
sub _importer_for {
my ($self, $ibx) = @_;
my $importers = $self->{importers};
my $im = $importers->{"$ibx"} ||= $ibx->importer(0);
if (scalar(keys(%$importers)) > 2) {
delete $importers->{"$ibx"};
_done_for_now($self);
}
$importers->{"$ibx"} = $im;
}
sub _spamcheck_cb {
my ($sc) = @_;
sub {
my ($mime) = @_;
my $tmp = '';
if ($sc->spamcheck($mime, \$tmp)) {
return PublicInbox::Eml->new(\$tmp);
}
warn $mime->header('Message-ID')." failed spam check\n";
undef;
}
}
sub is_maildir {
$_[0] =~ s!\Amaildir:!! or return;
$_[0] =~ tr!/!/!s;
$_[0] =~ s!/\z!!;
$_[0];
}
1;