nntp: support COMPRESS DEFLATE per RFC 8054

[public-inbox.git] / lib / PublicInbox / NNTP.pm

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 57a67a50ff8475f1882a4aa6a90aa2e477c1d4cc..d6f315bab42a9ed7e0b8b607a3ba6cf01066ef55 100644 (file)
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -14,11 +14,13 @@ use PublicInbox::Git;
 require PublicInbox::EvCleanup;
 use Email::Simple;
 use POSIX qw(strftime);
-PublicInbox::DS->import(qw(now msg_more));
+PublicInbox::DS->import(qw(now));
 use Digest::SHA qw(sha1_hex);
 use Time::Local qw(timegm timelocal);
 use constant {
+       LINE_MAX => 512, # RFC 977 section 2.3
        r501 => '501 command syntax error',
+       r502 => '502 Command unavailable',
        r221 => '221 Header follows',
        r224 => '224 Overview information follows (multi-line)',
        r225 => '225 Headers follow (multi-line)',
@@ -31,7 +33,16 @@ my @OVERVIEW = qw(Subject From Date Message-ID References Xref);
 my $OVERVIEW_FMT = join(":\r\n", @OVERVIEW, qw(Bytes Lines)) . ":\r\n";
 my $LIST_HEADERS = join("\r\n", @OVERVIEW,
                        qw(:bytes :lines Xref To Cc)) . "\r\n";
-
+my $CAPABILITIES = <<"";
+101 Capability list:\r
+VERSION 2\r
+READER\r
+NEWNEWS\r
+LIST ACTIVE ACTIVE.TIMES NEWSGROUPS OVERVIEW.FMT\r
+HDR\r
+OVER\r
+
+my $have_deflate;
 my $EXPMAP; # fd -> [ idle_time, $self ]
 my $expt;
 our $EXPTIME = 180; # 3 minutes
@@ -121,6 +132,17 @@ sub process_line ($$) {
        res($self, $res);
 }
 
+# The keyword argument is not used (rfc3977 5.2.2)
+sub cmd_capabilities ($;$) {
+       my ($self, undef) = @_;
+       my $res = $CAPABILITIES;
+       if (ref($self->{sock}) ne 'IO::Socket::SSL' &&
+                       $self->{nntpd}->{accept_tls}) {
+               $res .= "STARTTLS\r\n";
+       }
+       $res .= '.';
+}
+
 sub cmd_mode ($$) {
        my ($self, $arg) = @_;
        $arg = uc $arg;
@@ -139,12 +161,12 @@ sub cmd_xgtitle ($;$) {
 
 sub list_overview_fmt ($) {
        my ($self) = @_;
-       msg_more($self, $OVERVIEW_FMT);
+       $self->msg_more($OVERVIEW_FMT);
 }
 
 sub list_headers ($;$) {
        my ($self) = @_;
-       msg_more($self, $LIST_HEADERS);
+       $self->msg_more($LIST_HEADERS);
 }
 
 sub list_active ($;$) {
@@ -498,7 +520,7 @@ sub msg_body_write ($$) {
        $$msg =~ s/^\./../smg;
        $$msg =~ s/(?<!\r)\n/\r\n/sg; # Alpine barfs without this
        $$msg .= "\r\n" unless $$msg =~ /\r\n\z/s;
-       msg_more($self, $$msg);
+       $self->msg_more($$msg);
        '.'
 }
 
@@ -519,7 +541,7 @@ sub msg_hdr_write ($$$) {
        # affect messages already in the archive.
        $hdr =~ s/^(Message-ID:)[ \t]*\r\n[ \t]+([^\r]+)\r\n/$1 $2\r\n/igsm;
        $hdr .= "\r\n" if $body_follows;
-       msg_more($self, $hdr);
+       $self->msg_more($hdr);
 }
 
 sub cmd_article ($;$) {
@@ -738,7 +760,7 @@ sub hdr_searchmsg ($$$$) {
                                $tmp .= $s->{num} . ' ' . $s->$field . "\r\n";
                        }
                        utf8::encode($tmp);
-                       msg_more($self, $tmp);
+                       $self->msg_more($tmp);
                        $cur = $msgs->[-1]->{num} + 1;
                });
        }
@@ -877,11 +899,13 @@ sub cmd_xover ($;$) {
        });
 }
 
+sub compressed { undef }
+
 sub cmd_starttls ($) {
        my ($self) = @_;
        my $sock = $self->{sock} or return;
        # RFC 4642 2.2.1
-       (ref($sock) eq 'IO::Socket::SSL') and return '502 Command unavailable';
+       return r502 if (ref($sock) eq 'IO::Socket::SSL' || $self->compressed);
        my $opt = $self->{nntpd}->{accept_tls} or
                return '580 can not initiate TLS negotiation';
        res($self, '382 Continue with TLS negotiation');
@@ -890,6 +914,17 @@ sub cmd_starttls ($) {
        undef;
 }
 
+# RFC 8054
+sub cmd_compress ($$) {
+       my ($self, $alg) = @_;
+       return '503 Only the DEFLATE is supported' if uc($alg) ne 'DEFLATE';
+       return r502 if $self->compressed || !$have_deflate;
+       res($self, '206 Compression active');
+       PublicInbox::NNTPdeflate->enable($self);
+       $self->requeue;
+       undef
+}
+
 sub cmd_xpath ($$) {
        my ($self, $mid) = @_;
        return r501 unless $mid =~ /\A<(.+)>\z/;
@@ -905,7 +940,7 @@ sub cmd_xpath ($$) {
 
 sub res ($$) { do_write($_[0], $_[1] . "\r\n") }
 
-sub more ($$) { msg_more($_[0], $_[1] . "\r\n") }
+sub more ($$) { $_[0]->msg_more($_[1] . "\r\n") }
 
 sub do_write ($$) {
        my $self = $_[0];
@@ -935,7 +970,6 @@ sub event_step {
        # only read more requests if we've drained the write buffer,
        # otherwise we can be buffering infinitely w/o backpressure
 
-       use constant LINE_MAX => 512; # RFC 977 section 2.3
        my $rbuf = $self->{rbuf} // (\(my $x = ''));
        my $r = 1;
 
@@ -978,4 +1012,10 @@ sub busy {
        ($self->{rbuf} || $self->{wbuf} || not_idle_long($self, $now));
 }
 
+# this is an import to prevent "perl -c" from complaining about fields
+sub import {
+       $have_deflate = eval { require PublicInbox::NNTPdeflate } and
+               $CAPABILITIES .= "COMPRESS DEFLATE\r\n";
+}
+
 1;