--- /dev/null
+# Copyright (C) 2015 all contributors <meta@public-inbox.org>
+# License: AGPLv3 or later (https://www.gnu.org/licenses/agpl-3.0.txt)
+package PublicInbox::NNTP;
+use strict;
+use warnings;
+use base qw(Danga::Socket);
+use fields qw(nntpd article ng);
+use PublicInbox::Msgmap;
+use PublicInbox::GitCatFile;
+use PublicInbox::MID qw(mid2path);
+use Email::Simple;
+use Data::Dumper qw(Dumper);
+use POSIX qw(strftime);
+use constant {
+ r501 => '501 command syntax error',
+};
+
+my @OVERVIEW = qw(Subject From Date Message-ID References Bytes Lines);
+my %OVERVIEW = map { $_ => 1 } @OVERVIEW;
+
+# disable commands with easy DoS potential:
+# LISTGROUP could get pretty bad, too...
+my %DISABLED; # = map { $_ => 1 } qw(xover list_overview_fmt newnews xhdr);
+
+sub new {
+ my ($class, $sock, $nntpd) = @_;
+ my $self = fields::new($class);
+ $self->SUPER::new($sock);
+ $self->{nntpd} = $nntpd;
+ res($self, '201 server ready - post via email');
+ $self->watch_read(1);
+ $self;
+}
+
+# returns 1 if we can continue, 0 if not due to buffered writes or disconnect
+sub process_line {
+ my ($self, $l) = @_;
+ my ($req, @args) = split(/\s+/, $l);
+ $req = lc($req);
+ $req = eval {
+ no strict 'refs';
+ $req = $DISABLED{$req} ? undef : *{'cmd_'.$req}{CODE};
+ };
+ return res($self, '500 command not recognized') unless $req;
+
+ my $res = eval { $req->($self, @args) };
+ my $err = $@;
+ if ($err && !$self->{closed}) {
+ chomp($l = Dumper(\$l));
+ warning('error from: ', $l, ' ', $err);
+ $res = '503 program fault - command not performed';
+ }
+ return 0 unless defined $res;
+ res($self, $res);
+}
+
+sub cmd_mode {
+ my ($self, $arg) = @_;
+ return r501 unless defined $arg;
+ $arg = uc $arg;
+ return r501 unless $arg eq 'READER';
+ '200 reader status acknowledged';
+}
+
+sub cmd_slave {
+ my ($self, @x) = @_;
+ return r501 if @x;
+ '202 slave status noted';
+}
+
+sub cmd_xgtitle {
+ my ($self, $wildmat) = @_;
+ more($self, '282 list of groups and descriptions follows');
+ list_newsgroups($self, $wildmat);
+ '.'
+}
+
+sub list_overview_fmt {
+ my ($self) = @_;
+ more($self, $_ . ':') foreach @OVERVIEW;
+}
+
+sub list_active {
+ my ($self, $wildmat) = @_;
+ wildmat2re($wildmat);
+ foreach my $ng (values %{$self->{nntpd}->{groups}}) {
+ $ng->{name} =~ $wildmat or next;
+ group_line($self, $ng);
+ }
+}
+
+sub list_active_times {
+ my ($self, $wildmat) = @_;
+ wildmat2re($wildmat);
+ foreach my $ng (values %{$self->{nntpd}->{groups}}) {
+ $ng->{name} =~ $wildmat or next;
+ my $c = eval { $ng->mm->created_at } || time;
+ more($self, "$ng->{name} $c $ng->{address}");
+ }
+}
+
+sub list_newsgroups {
+ my ($self, $wildmat) = @_;
+ wildmat2re($wildmat);
+ foreach my $ng (values %{$self->{nntpd}->{groups}}) {
+ $ng->{name} =~ $wildmat or next;
+ my $d = $ng->description;
+ more($self, "$ng->{name} $d");
+ }
+}
+
+# LIST SUBSCRIPTIONS not supported
+sub cmd_list {
+ my ($self, $arg, $wildmat, @x) = @_;
+ if (defined $arg) {
+ $arg = lc $arg;
+ $arg =~ tr/./_/;
+ $arg = "list_$arg";
+ return '503 function not performed' if $DISABLED{$arg};
+ $arg = eval {
+ no strict 'refs';
+ *{$arg}{CODE};
+ };
+ return r501 unless $arg;
+ more($self, '215 information follows');
+ $arg->($self, $wildmat, @x);
+ } else {
+ more($self, '215 list of newsgroups follows');
+ foreach my $ng (values %{$self->{nntpd}->{groups}}) {
+ group_line($self, $ng);
+ }
+ }
+ '.'
+}
+
+sub cmd_listgroup {
+ my ($self, $group) = @_;
+ if (defined $group) {
+ my $res = cmd_group($self, $group);
+ return $res if ($res !~ /\A211 /);
+ more($self, $res);
+ }
+
+ my $ng = $self->{ng} or return '412 no newsgroup selected';
+ # Ugh this can be silly expensive for big groups
+ $ng->mm->each_id_batch(sub {
+ my ($ary) = @_;
+ more($self, join("\r\n", @$ary));
+ });
+ '.'
+}
+
+sub parse_time {
+ my ($date, $time, $gmt) = @_;
+ use Time::Local qw();
+ my ($YY, $MM, $DD) = unpack('A2A2A2', $date);
+ my ($hh, $mm, $ss) = unpack('A2A2A2', $time);
+ if (defined $gmt) {
+ $gmt =~ /\A(?:UTC|GMT)\z/i or die "GM invalid: $gmt\n";
+ $gmt = 1;
+ }
+ my @now = $gmt ? gmtime : localtime;
+ if ($YY > strftime('%y', @now)) {
+ my $cur_year = $now[5] + 1900;
+ $YY += int($cur_year / 1000) * 1000 - 100;
+ }
+
+ if ($gmt) {
+ Time::Local::timegm($ss, $mm, $hh, $DD, $MM - 1, $YY);
+ } else {
+ Time::Local::timelocal($ss, $mm, $hh, $DD, $MM - 1, $YY);
+ }
+}
+
+sub group_line {
+ my ($self, $ng) = @_;
+ my ($min, $max) = $ng->mm->minmax;
+ more($self, "$ng->{name} $max $min n") if defined $min && defined $max;
+}
+
+sub cmd_newgroups {
+ my ($self, $date, $time, $gmt, $dists) = @_;
+ my $ts = eval { parse_time($date, $time, $gmt) };
+ return r501 if $@;
+
+ # TODO dists
+ more($self, '231 list of new newsgroups follows');
+ foreach my $ng (values %{$self->{nntpd}->{groups}}) {
+ my $c = eval { $ng->mm->created_at } || 0;
+ next unless $c > $ts;
+ group_line($self, $ng);
+ }
+ '.'
+}
+
+sub wildmat2re {
+ return $_[0] = qr/.*/ if (!defined $_[0] || $_[0] eq '*');
+ my %keep;
+ my $salt = rand;
+ use Digest::SHA qw(sha1_hex);
+ my $tmp = $_[0];
+
+ $tmp =~ s#(?<!\\)\[(.+)(?<!\\)\]#
+ my $orig = $1;
+ my $key = sha1_hex($orig . $salt);
+ $orig =~ s/([^\w\-])+/\Q$1/g;
+ $keep{$key} = $orig;
+ $key
+ #gex;
+ my %map = ('*' => '.*', '?' => '.' );
+ $tmp =~ s#(?<!\\)([^\w\\])#$map{$1} || "\Q$1"#ge;
+ if (scalar %keep) {
+ $tmp =~ s#([a-f0-9]{40})#
+ my $orig = $keep{$1};
+ defined $orig ? $orig : $1;
+ #ge;
+ }
+ $_[0] = qr/\A$tmp\z/;
+}
+
+sub ngpat2re {
+ return $_[0] = qr/\A\z/ unless defined $_[0];
+ my %map = ('*' => '.*', ',' => '|');
+ $_[0] =~ s!(.)!$map{$1} || "\Q$1"!ge;
+ $_[0] = qr/\A(?:$_[0])\z/;
+}
+
+sub cmd_newnews {
+ my ($self, $newsgroups, $date, $time, $gmt, $dists) = @_;
+ my $ts = eval { parse_time($date, $time, $gmt) };
+ return r501 if $@;
+ more($self, '230 list of new articles by message-id follows');
+ my ($keep, $skip) = split('!', $newsgroups, 2);
+ ngpat2re($keep);
+ ngpat2re($skip);
+ $ts .= '..';
+
+ my $opts = { asc => 1, limit => 1000 };
+ foreach my $ng (values %{$self->{nntpd}->{groups}}) {
+ $ng->{name} =~ $keep or next;
+ $ng->{name} =~ $skip and next;
+ my $srch = $ng->search or next;
+ $opts->{offset} = 0;
+
+ while (1) {
+ my $res = $srch->query($ts, $opts);
+ my $msgs = $res->{msgs};
+ my $nr = scalar @$msgs or last;
+ more($self, '<' .
+ join(">\r\n<", map { $_->mid } @$msgs ).
+ '>');
+ $opts->{offset} += $nr;
+ }
+ }
+ '.';
+}
+
+sub cmd_group {
+ my ($self, $group) = @_;
+ my $no_such = '411 no such news group';
+ my $ng = $self->{nntpd}->{groups}->{$group} or return $no_such;
+
+ $self->{ng} = $ng;
+ my ($min, $max) = $ng->mm->minmax;
+ $min ||= 0;
+ $max ||= 0;
+ $self->{article} = $min;
+ my $est_size = $max - $min;
+ "211 $est_size $min $max $group";
+}
+
+sub article_adj {
+ my ($self, $off) = @_;
+ my $ng = $self->{ng} or return '412 no newsgroup selected';
+
+ my $n = $self->{article};
+ defined $n or return '420 no current article has been selected';
+
+ $n += $off;
+ my $mid = $ng->mm->mid_for($n);
+ unless ($mid) {
+ $n = $off > 0 ? 'next' : 'previous';
+ return "421 no $n article in this group";
+ }
+ $self->{article} = $n;
+ "223 $n <$mid> article retrieved - request text separately";
+}
+
+sub cmd_next { article_adj($_[0], 1) }
+sub cmd_last { article_adj($_[0], -1) }
+
+# We want to encourage using email and CC-ing everybody involved to avoid
+# the single-point-of-failure a single server provides.
+sub cmd_post {
+ my ($self) = @_;
+ my $ng = $self->{ng};
+ $ng ? "440 mailto:$ng->{address} to post" : '440 posting not allowed'
+}
+
+sub cmd_quit {
+ my ($self) = @_;
+ res($self, '205 closing connection - goodbye!');
+ $self->close;
+ undef;
+}
+
+sub art_lookup {
+ my ($self, $art, $set_headers) = @_;
+ my $ng = $self->{ng} or return '412 no newsgroup has been selected';
+ my ($n, $mid);
+ my $err;
+ if (defined $art) {
+ if ($art =~ /\A\d+\z/o) {
+ $err = '423 no such article number in this group';
+ $n = int($art);
+ goto find_mid;
+ } elsif ($art =~ /\A<([^>]+)>\z/) {
+ $err = '430 no such article found';
+ $mid = $1;
+ $n = $ng->mm->num_for($mid);
+ defined $mid or return $err;
+ } else {
+ return r501;
+ }
+ } else {
+ $err = '420 no current article has been selected';
+ $n = $self->{article};
+ defined $n or return $err;
+find_mid:
+ $mid = $ng->mm->mid_for($n);
+ defined $mid or return $err;
+ }
+
+ my $o = 'HEAD:' . mid2path($mid);
+ my $s = eval { Email::Simple->new($ng->gcf->cat_file($o)) };
+ return $err unless $s;
+ if ($set_headers) {
+ $s->header_set('Newsgroups', $ng->{name});
+ $s->header_set('Lines', $s->body =~ tr!\n!\n!);
+ $s->header_set('Xref', "$ng->{domain} $ng->{name}:$n");
+
+ # must be last
+ if ($set_headers == 2) {
+ $s->header_set('Bytes', bytes::length($s->as_string));
+ $s->body_set('');
+ }
+ }
+ [ $n, $mid, $s ];
+}
+
+sub simple_body_write {
+ my ($self, $s) = @_;
+ my $body = $s->body;
+ $s->body_set('');
+ $body =~ s/^\./../smg;
+ do_more($self, $body);
+ '.'
+}
+
+sub header_str {
+ my ($s) = @_;
+ my $h = $s->header_obj;
+ $h->header_set('Bytes');
+ $h->as_string
+}
+
+sub cmd_article {
+ my ($self, $art) = @_;
+ my $r = $self->art_lookup($art, 1);
+ return $r unless ref $r;
+ my ($n, $mid, $s) = @$r;
+ more($self, "220 $n <$mid> article retrieved - head and body follow");
+ do_more($self, header_str($s));
+ do_more($self, "\r\n");
+ simple_body_write($self, $s);
+}
+
+sub cmd_head {
+ my ($self, $art) = @_;
+ my $r = $self->art_lookup($art, 2);
+ return $r unless ref $r;
+ my ($n, $mid, $s) = @$r;
+ more($self, "221 $n <$mid> article retrieved - head follows");
+ do_more($self, header_str($s));
+ '.'
+}
+
+sub cmd_body {
+ my ($self, $art) = @_;
+ my $r = $self->art_lookup($art, 0);
+ return $r unless ref $r;
+ my ($n, $mid, $s) = @$r;
+ more($self, "222 $n <$mid> article retrieved - body follows");
+ simple_body_write($self, $s);
+}
+
+sub cmd_stat {
+ my ($self, $art) = @_;
+ my $r = $self->art_lookup($art, 0);
+ return $r unless ref $r;
+ my ($n, $mid, undef) = @$r;
+ "223 $n <$mid> article retrieved - request text separately";
+}
+
+sub cmd_ihave { '435 article not wanted - do not send it' }
+
+sub cmd_date { '111 '.strftime('%Y%m%d%H%M%S', gmtime(time)) }
+
+sub cmd_help {
+ my ($self) = @_;
+ more($self, '100 help text follows');
+ '.'
+}
+
+sub get_range {
+ my ($self, $range) = @_;
+ my $ng = $self->{ng} or return '412 no news group has been selected';
+ defined $range or return '420 No article(s) selected';
+ my ($beg, $end);
+ my ($min, $max) = $ng->mm->minmax;
+ if ($range =~ /\A(\d+)\z/) {
+ $beg = $end = $1;
+ } elsif ($range =~ /\A(\d+)-\z/) {
+ ($beg, $end) = ($1, $max);
+ } elsif ($range =~ /\A(\d+)-(\d+)\z/) {
+ ($beg, $end) = ($1, $2);
+ } else {
+ return r501;
+ }
+ $beg = $min if ($beg < $min);
+ $end = $max if ($end > $max);
+ return '420 No article(s) selected' if ($beg > $end);
+ [ $beg, $end ];
+}
+
+sub xhdr {
+ my ($r, $header) = @_;
+ $r = $r->[2]->header_obj->header($header);
+ defined $r or return;
+ $r =~ s/[\r\n\t]+/ /sg;
+ $r;
+}
+
+sub cmd_xhdr {
+ my ($self, $header, $range) = @_;
+ defined $self->{ng} or return '412 no news group currently selected';
+ unless (defined $range) {
+ defined($range = $self->{article}) or
+ return '420 no current article has been selected';
+ }
+ if ($range =~ /\A<(.+)>\z/) { # Message-ID
+ my $r = $self->art_lookup($range, 2);
+ return $r unless ref $r;
+ more($self, '221 Header follows');
+ if (defined($r = xhdr($r, $header))) {
+ more($self, "<$range> $r");
+ }
+ } else { # numeric range
+ my $r = get_range($self, $range);
+ return $r unless ref $r;
+ my ($beg, $end) = @$r;
+ more($self, '221 Header follows');
+ foreach my $i ($beg..$end) {
+ $r = $self->art_lookup($i, 2);
+ next unless ref $r;
+ defined($r = xhdr($r, $header)) or next;
+ more($self, "$i $r");
+ }
+ }
+ '.';
+}
+
+sub cmd_xover {
+ my ($self, $range) = @_;
+ my $r = get_range($self, $range);
+ return $r unless ref $r;
+ my ($beg, $end) = @$r;
+ more($self, "224 Overview information follows for $beg to $end");
+ foreach my $i ($beg..$end) {
+ my $r = $self->art_lookup($i, 2);
+ next unless ref $r;
+ more($self, join("\t", $r->[0],
+ map {
+ my $h = xhdr($r, $_);
+ defined $h ? $h : '';
+ } @OVERVIEW ));
+ }
+ '.';
+}
+
+sub res {
+ my ($self, $line) = @_;
+ do_write($self, $line . "\r\n");
+}
+
+sub more {
+ my ($self, $line) = @_;
+ do_more($self, $line . "\r\n");
+}
+
+sub do_write {
+ my ($self, $data) = @_;
+ my $done = $self->write($data);
+ die if $self->{closed};
+
+ # Do not watch for readability if we have data in the queue,
+ # instead re-enable watching for readability when we can
+ $self->watch_read(0) unless $done;
+
+ $done;
+}
+
+use constant MSG_MORE => ($^O eq 'linux') ? 0x8000 : 0;
+
+sub do_more {
+ my ($self, $data) = @_;
+ if (MSG_MORE && !scalar @{$self->{write_buf}}) {
+ my $n = send($self->{sock}, $data, MSG_MORE);
+ if (defined $n) {
+ my $dlen = bytes::length($data);
+ return 1 if $n == $dlen; # all done!
+ $data = bytes::substr($data, $n, $dlen - $n);
+ }
+ }
+ $self->do_write($data);
+}
+
+# callbacks for by Danga::Socket
+
+sub event_hup { $_[0]->close }
+sub event_err { $_[0]->close }
+
+sub event_write {
+ my ($self) = @_;
+ # only continue watching for readability when we are done writing:
+ $self->write(undef) == 1 and $self->watch_read(1);
+}
+
+sub event_read {
+ my ($self) = @_;
+ use constant LINE_MAX => 512; # RFC 977 section 2.3
+ use Time::HiRes qw(gettimeofday tv_interval);
+ my $r = 1;
+ my $buf = $self->read(LINE_MAX) or return $self->close;
+ while ($r > 0 && $$buf =~ s/\A([^\r\n]+)\r?\n//) {
+ my $line = $1;
+ my $t0 = [ gettimeofday ];
+ $r = eval { $self->process_line($line) };
+ printf(STDERR "$line %0.6f\n",
+ tv_interval($t0, [gettimeofday]));
+ }
+ return $self->close if $r < 0;
+ my $len = bytes::length($$buf);
+ return $self->close if ($len >= LINE_MAX);
+ $self->push_back_read($buf) if ($len);
+}
+
+sub warning { print STDERR @_, "\n" }
+
+1;