1 # Copyright (C) 2020 all contributors <meta@public-inbox.org>
2 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
4 # Each instance of this represents an IMAP client connected to
5 # public-inbox-imapd. Much of this was taken from NNTP, but
6 # further refined while experimenting on future ideas to handle
10 # * NNTP article numbers are UIDs and message sequence numbers (MSNs)
11 # * Message sequence numbers (MSNs) can be stable since we're read-only.
12 # Most IMAP clients use UIDs (I hope), and we can return a dummy
13 # message if a client requests a non-existent MSN.
15 package PublicInbox::IMAP;
17 use base qw(PublicInbox::DS);
18 use fields qw(imapd logged_in ibx long_cb -login_tag
21 use PublicInbox::DS qw(now);
22 use PublicInbox::Syscall qw(EPOLLIN EPOLLONESHOT);
23 use Text::ParseWords qw(parse_line);
26 for my $mod (qw(Email::Address::XS Mail::Address)) {
27 eval "require $mod" or next;
28 $Address = $mod and last;
30 die "neither Email::Address::XS nor Mail::Address loaded: $@" if !$Address;
32 sub LINE_MAX () { 512 } # does RFC 3501 have a limit like RFC 977?
34 my %FETCH_NEED_BLOB = ( # for future optimization
35 'BODY.PEEK[HEADER]' => 1,
36 'BODY.PEEK[TEXT]' => 1,
42 'RFC822.SIZE' => 1, # needs CRLF conversion :<
52 my %FETCH_ATT = map { $_ => [ $_ ] } keys %FETCH_NEED_BLOB;
54 # aliases (RFC 3501 section 6.4.5)
55 $FETCH_ATT{FAST} = [ qw(FLAGS INTERNALDATE RFC822.SIZE) ];
56 $FETCH_ATT{ALL} = [ @{$FETCH_ATT{FAST}}, 'ENVELOPE' ];
57 $FETCH_ATT{FULL} = [ @{$FETCH_ATT{ALL}}, 'BODY' ];
59 for my $att (keys %FETCH_ATT) {
60 my %h = map { $_ => 1 } @{$FETCH_ATT{$att}};
61 $FETCH_ATT{$att} = \%h;
66 my $capa = capa($self);
67 $self->write(\"* OK [$capa] public-inbox-imapd ready\r\n");
71 my ($class, $sock, $imapd) = @_;
72 my $self = fields::new($class);
75 if ($sock->can('accept_SSL') && !$sock->accept_SSL) {
76 return CORE::close($sock) if $! != EAGAIN;
77 $ev = PublicInbox::TLS::epollbit();
78 $wbuf = [ \&PublicInbox::DS::accept_tls_step, \&greet ];
80 $self->SUPER::new($sock, $ev | EPOLLONESHOT);
81 $self->{imapd} = $imapd;
83 $self->{wbuf} = $wbuf;
87 $self->update_idle_time;
94 # dovecot advertises IDLE pre-login; perhaps because some clients
95 # depend on it, so we'll do the same
96 my $capa = 'CAPABILITY IMAP4rev1 IDLE';
97 if ($self->{logged_in}) {
98 $capa .= ' COMPRESS=DEFLATE';
100 if (!($self->{sock} // $self)->can('accept_SSL') &&
101 $self->{imapd}->{accept_tls}) {
102 $capa .= ' STARTTLS';
104 $capa .= ' AUTH=ANONYMOUS';
108 sub login_success ($$) {
109 my ($self, $tag) = @_;
110 $self->{logged_in} = 1;
111 my $capa = capa($self);
112 "$tag OK [$capa] Logged in\r\n";
115 sub auth_challenge_ok ($) {
117 my $tag = delete($self->{-login_tag}) or return;
118 login_success($self, $tag);
121 sub cmd_login ($$$$) {
122 my ($self, $tag) = @_; # ignore ($user, $password) = ($_[2], $_[3])
123 login_success($self, $tag);
126 sub cmd_logout ($$) {
127 my ($self, $tag) = @_;
128 delete $self->{logged_in};
129 $self->write(\"* BYE logging out\r\n$tag OK logout completed\r\n");
130 $self->shutdn; # PublicInbox::DS::shutdn
134 sub cmd_authenticate ($$$) {
135 my ($self, $tag) = @_; # $method = $_[2], should be "ANONYMOUS"
136 $self->{-login_tag} = $tag;
140 sub cmd_capability ($$) {
141 my ($self, $tag) = @_;
142 '* '.capa($self)."\r\n$tag OK\r\n";
145 sub cmd_noop ($$) { "$_[1] OK NOOP completed\r\n" }
147 # called by PublicInbox::InboxIdle
148 sub on_inbox_unlock {
149 my ($self, $ibx) = @_;
150 my $new = $ibx->mm->max;
151 defined(my $old = $self->{-idle_max}) or die 'BUG: -idle_max unset';
153 $self->{-idle_max} = $new;
154 $self->msg_more("* $_ EXISTS\r\n") for (($old + 1)..($new - 1));
155 $self->write(\"* $new EXISTS\r\n");
160 my ($self, $tag) = @_;
161 # IDLE seems allowed by dovecot w/o a mailbox selected *shrug*
162 my $ibx = $self->{ibx} or return "$tag BAD no mailbox selected\r\n";
163 $ibx->subscribe_unlock(fileno($self->{sock}), $self);
164 $self->{imapd}->idler_start;
165 $self->{-idle_tag} = $tag;
166 $self->{-idle_max} = $ibx->mm->max // 0;
171 my ($self, $tag) = @_; # $tag is "DONE" (case-insensitive)
172 defined(my $idle_tag = delete $self->{-idle_tag}) or
173 return "$tag BAD not idle\r\n";
174 my $ibx = $self->{ibx} or do {
175 warn "BUG: idle_tag set w/o inbox";
176 return "$tag BAD internal bug\r\n";
178 $ibx->unsubscribe_unlock(fileno($self->{sock}));
179 "$idle_tag OK Idle completed\r\n";
182 sub cmd_examine ($$$) {
183 my ($self, $tag, $mailbox) = @_;
184 my $ibx = $self->{imapd}->{groups}->{$mailbox} or
185 return "$tag NO Mailbox doesn't exist: $mailbox\r\n";
187 my $max = $mm->max // 0;
188 # RFC 3501 2.3.1.1 - "A good UIDVALIDITY value to use in
189 # this case is a 32-bit representation of the creation
190 # date/time of the mailbox"
191 my $uidvalidity = $mm->created_at or return "$tag BAD UIDVALIDITY\r\n";
192 my $uidnext = $max + 1;
194 # XXX: do we need this? RFC 5162/7162
195 my $ret = $self->{ibx} ? "* OK [CLOSED] previous closed\r\n" : '';
201 * OK [PERMANENTFLAGS ()] Read-only mailbox\r
203 $ret .= "* OK [UNSEEN $max]\r\n" if $max;
204 $ret .= "* OK [UIDNEXT $uidnext]\r\n" if defined $uidnext;
205 $ret .= "* OK [UIDVALIDITY $uidvalidity]\r\n" if defined $uidvalidity;
206 $ret .= "$tag OK [READ-ONLY] EXAMINE/SELECT complete\r\n";
213 } elsif ($v =~ /[{"\r\n%*\\\[]/) { # literal string
214 '{' . length($v) . "}\r\n" . $v;
215 } else { # quoted string
220 sub addr_envelope ($$;$) {
221 my ($eml, $x, $y) = @_;
222 my $v = $eml->header_raw($x) //
223 ($y ? $eml->header_raw($y) : undef) // return 'NIL';
225 my @x = $Address->parse($v) or return 'NIL';
227 map { '(' . join(' ',
228 _esc($_->name), 'NIL',
229 _esc($_->user), _esc($_->host)
235 sub eml_envelope ($) {
238 _esc($eml->header_raw('Date')),
239 _esc($eml->header_raw('Subject')),
240 addr_envelope($eml, 'From'),
241 addr_envelope($eml, 'Sender', 'From'),
242 addr_envelope($eml, 'Reply-To', 'From'),
243 addr_envelope($eml, 'To'),
244 addr_envelope($eml, 'Cc'),
245 addr_envelope($eml, 'Bcc'),
246 _esc($eml->header_raw('In-Reply-To')),
247 _esc($eml->header_raw('Message-ID')),
251 sub uid_fetch_cb { # called by git->cat_async
252 my ($bref, $oid, $type, $size, $fetch_m_arg) = @_;
253 my ($self, undef, $ibx, undef, undef, $msgs, $want) = @$fetch_m_arg;
254 my $smsg = shift @$msgs or die 'BUG: no smsg';
255 $smsg->{blob} eq $oid or die "BUG: $smsg->{blob} != $oid";
256 $$bref =~ s/(?<!\r)\n/\r\n/sg; # make strict clients happy
258 # fixup old bug from import (pre-a0c07cba0e5d8b6a)
259 $$bref =~ s/\A[\r\n]*From [^\r\n]*\r\n//s;
261 $self->msg_more("* $smsg->{num} FETCH (UID $smsg->{num}");
263 $want->{'RFC822.SIZE'} and
264 $self->msg_more(' RFC822.SIZE '.length($$bref));
265 $want->{INTERNALDATE} and
266 $self->msg_more(' INTERNALDATE "'.$smsg->internaldate.'"');
267 $want->{FLAGS} and $self->msg_more(' FLAGS ()');
268 for ('RFC822', 'BODY[]', 'BODY.PEEK[]') {
269 next unless $want->{$_};
270 $self->msg_more(" $_ {".length($$bref)."}\r\n");
271 $self->msg_more($$bref);
274 my $eml = PublicInbox::Eml->new($bref);
276 $want->{ENVELOPE} and
277 $self->msg_more(' ENVELOPE '.eml_envelope($eml));
279 for my $f ('RFC822.HEADER', 'BODY[HEADER]', 'BODY.PEEK[HEADER]') {
280 next unless $want->{$f};
281 $self->msg_more(" $f {".length(${$eml->{hdr}})."}\r\n");
282 $self->msg_more(${$eml->{hdr}});
284 for my $f ('RFC822.TEXT', 'BODY[TEXT]') {
285 next unless $want->{$f};
286 $self->msg_more(" $f {".length($$bref)."}\r\n");
287 $self->msg_more($$bref);
289 # TODO BODY/BODYSTRUCTURE, specific headers
290 $self->msg_more(")\r\n");
293 sub uid_fetch_m { # long_response
294 my ($self, $tag, $ibx, $beg, $end, $msgs, $want) = @_;
295 if (!@$msgs) { # refill
296 @$msgs = @{$ibx->over->query_xover($$beg, $end)};
298 $self->write(\"$tag OK Fetch done\r\n");
301 $$beg = $msgs->[-1]->{num} + 1;
304 $git->cat_async_begin; # TODO: actually make async
305 $git->cat_async($msgs->[0]->{blob}, \&uid_fetch_cb, \@_);
306 $git->cat_async_wait;
310 sub cmd_status ($$$;@) {
311 my ($self, $tag, $mailbox, @items) = @_;
312 my $ibx = $self->{imapd}->{groups}->{$mailbox} or
313 return "$tag NO Mailbox doesn't exist: $mailbox\r\n";
314 return "$tag BAD no items\r\n" if !scalar(@items);
315 ($items[0] !~ s/\A\(//s || $items[-1] !~ s/\)\z//s) and
316 return "$tag BAD invalid args\r\n";
320 for my $it (@items) {
323 if ($it =~ /\A(?:MESSAGES|UNSEEN|RECENT)\z/) {
324 push(@it, ($max //= $mm->max // 0));
325 } elsif ($it eq 'UIDNEXT') {
326 push(@it, ($max //= $mm->max // 0) + 1);
327 } elsif ($it eq 'UIDVALIDITY') {
328 push(@it, $mm->created_at //
329 return("$tag BAD UIDVALIDITY\r\n"));
331 return "$tag BAD invalid item\r\n";
334 return "$tag BAD no items\r\n" if !@it;
335 "* STATUS $mailbox (".join(' ', @it).")\r\n" .
336 "$tag OK Status complete\r\n";
339 my %patmap = ('*' => '.*', '%' => '[^\.]*');
340 sub cmd_list ($$$$) {
341 my ($self, $tag, $refname, $wildcard) = @_;
342 my $l = $self->{imapd}->{inboxlist};
343 if ($refname eq '' && $wildcard eq '') {
344 # request for hierarchy delimiter
345 $l = [ qq[* LIST (\\Noselect) "." ""\r\n] ];
346 } elsif ($refname ne '' || $wildcard ne '*') {
347 $wildcard =~ s!([^a-z0-9_])!$patmap{$1} // "\Q$1"!eig;
348 $l = [ grep(/ \Q$refname\E$wildcard\r\n\z/s, @$l) ];
350 \(join('', @$l, "$tag OK List complete\r\n"));
353 sub cmd_uid_fetch ($$$;@) {
354 my ($self, $tag, $range, @want) = @_;
355 my $ibx = $self->{ibx} or return "$tag BAD No mailbox selected\r\n";
356 if ($want[0] =~ s/\A\(//s) {
357 $want[-1] =~ s/\)\z//s or return "$tag BAD no rparen\r\n";
360 my $x = $FETCH_ATT{uc($_)} or return "$tag BAD param: $_\r\n";
365 if ($range =~ /\A([0-9]+):([0-9]+)\z/s) {
366 ($beg, $end) = ($1, $2);
367 } elsif ($range =~ /\A([0-9]+):\*\z/s) {
368 ($beg, $end) = ($1, $ibx->mm->max // 0);
369 } elsif ($range =~ /\A[0-9]+\z/) {
370 my $smsg = $ibx->over->get_art($range) or return "$tag OK\r\n";
372 ($beg, $end) = ($range, 0);
374 return "$tag BAD\r\n";
376 long_response($self, \&uid_fetch_m, $tag, $ibx,
377 \$beg, $end, $msgs, \%want);
380 sub uid_search_all { # long_response
381 my ($self, $tag, $ibx, $num) = @_;
382 my $uids = $ibx->mm->ids_after($num);
383 if (scalar(@$uids)) {
384 $self->msg_more(join(' ', '', @$uids));
386 $self->write(\"\r\n$tag OK\r\n");
391 sub uid_search_uid_range { # long_response
392 my ($self, $tag, $ibx, $beg, $end) = @_;
393 my $uids = $ibx->mm->msg_range($beg, $end, 'num');
395 $self->msg_more(join('', map { " $_->[0]" } @$uids));
397 $self->write(\"\r\n$tag OK\r\n");
402 sub cmd_uid_search ($$$;) {
403 my ($self, $tag, $arg, @rest) = @_;
404 my $ibx = $self->{ibx} or return "$tag BAD No mailbox selected\r\n";
406 if ($arg eq 'ALL' && !@rest) {
407 $self->msg_more('* SEARCH');
409 long_response($self, \&uid_search_all, $tag, $ibx, \$num);
410 } elsif ($arg eq 'UID' && scalar(@rest) == 1) {
411 if ($rest[0] =~ /\A([0-9]+):([0-9]+|\*)\z/s) {
412 my ($beg, $end) = ($1, $2);
413 $end = $ibx->mm->max if $end eq '*';
414 $self->msg_more('* SEARCH');
415 long_response($self, \&uid_search_uid_range,
416 $tag, $ibx, \$beg, $end);
417 } elsif ($rest[0] =~ /\A[0-9]+\z/s) {
419 $uid = $ibx->over->get_art($uid) ? " $uid" : '';
420 "* SEARCH$uid\r\n$tag OK\r\n";
429 sub args_ok ($$) { # duplicated from PublicInbox::NNTP
430 my ($cb, $argc) = @_;
431 my $tot = prototype $cb;
432 my ($nreq, undef) = split(';', $tot);
433 $nreq = ($nreq =~ tr/$//) - 1;
434 $tot = ($tot =~ tr/$//) - 1;
435 ($argc <= $tot && $argc >= $nreq);
438 # returns 1 if we can continue, 0 if not due to buffered writes or disconnect
439 sub process_line ($$) {
441 my ($tag, $req, @args) = parse_line('[ \t]+', 0, $l);
442 pop(@args) if (@args && !defined($args[-1]));
443 if (@args && uc($req) eq 'UID') {
444 $req .= "_".(shift @args);
447 if (my $cmd = $self->can('cmd_'.lc($req // ''))) {
448 defined($self->{-idle_tag}) ?
449 "$self->{-idle_tag} BAD expected DONE\r\n" :
450 $cmd->($self, $tag, @args);
451 } elsif (uc($tag // '') eq 'DONE' && !defined($req)) {
452 cmd_done($self, $tag);
453 } else { # this is weird
454 auth_challenge_ok($self) //
455 "$tag BAD Error in IMAP command $req: ".
456 "Unknown command\r\n";
460 if ($err && $self->{sock}) {
462 err($self, 'error from: %s (%s)', $l, $err);
463 $res = "$tag BAD program fault - command not performed\r\n";
465 return 0 unless defined $res;
471 # wbuf is unset or empty, here; {long} may add to it
472 my ($fd, $cb, $t0, @args) = @{$self->{long_cb}};
473 my $more = eval { $cb->($self, @args) };
474 if ($@ || !$self->{sock}) { # something bad happened...
475 delete $self->{long_cb};
476 my $elapsed = now() - $t0;
479 "%s during long response[$fd] - %0.6f",
482 out($self, " deferred[$fd] aborted - %0.6f", $elapsed);
484 } elsif ($more) { # $self->{wbuf}:
485 $self->update_idle_time;
487 # COMPRESS users all share the same DEFLATE context.
488 # Flush it here to ensure clients don't see
492 # no recursion, schedule another call ASAP, but only after
493 # all pending writes are done. autovivify wbuf:
494 my $new_size = push(@{$self->{wbuf}}, \&long_step);
496 # wbuf may be populated by $cb, no need to rearm if so:
497 $self->requeue if $new_size == 1;
499 delete $self->{long_cb};
500 my $elapsed = now() - $t0;
501 my $fd = fileno($self->{sock});
502 out($self, " deferred[$fd] done - %0.6f", $elapsed);
503 my $wbuf = $self->{wbuf}; # do NOT autovivify
505 $self->requeue unless $wbuf && @$wbuf;
510 my ($self, $fmt, @args) = @_;
511 printf { $self->{imapd}->{err} } $fmt."\n", @args;
515 my ($self, $fmt, @args) = @_;
516 printf { $self->{imapd}->{out} } $fmt."\n", @args;
519 sub long_response ($$;@) {
520 my ($self, $cb, @args) = @_; # cb returns true if more, false if done
522 my $sock = $self->{sock} or return;
523 # make sure we disable reading during a long response,
524 # clients should not be sending us stuff and making us do more
525 # work while we are stream a response to them
526 $self->{long_cb} = [ fileno($sock), $cb, now(), @args ];
527 long_step($self); # kick off!
531 # callback used by PublicInbox::DS for any (e)poll (in/out/hup/err)
535 return unless $self->flush_write && $self->{sock};
537 $self->update_idle_time;
538 # only read more requests if we've drained the write buffer,
539 # otherwise we can be buffering infinitely w/o backpressure
541 my $rbuf = $self->{rbuf} // (\(my $x = ''));
544 if (index($$rbuf, "\n") < 0) {
545 my $off = length($$rbuf);
546 $r = $self->do_read($rbuf, LINE_MAX, $off) or return;
548 while ($r > 0 && $$rbuf =~ s/\A[ \t]*([^\n]*?)\r?\n//) {
550 return $self->close if $line =~ /[[:cntrl:]]/s;
552 my $fd = fileno($self->{sock});
553 $r = eval { process_line($self, $line) };
554 my $pending = $self->{wbuf} ? ' pending' : '';
555 out($self, "[$fd] %s - %0.6f$pending", $line, now() - $t0);
558 return $self->close if $r < 0;
559 my $len = length($$rbuf);
560 return $self->close if ($len >= LINE_MAX);
561 $self->rbuf_idle($rbuf);
562 $self->update_idle_time;
564 # maybe there's more pipelined data, or we'll have
565 # to register it for socket-readiness notifications
566 $self->requeue unless $self->{wbuf};
569 sub compressed { undef }
571 sub zflush {} # overridden by IMAPdeflate
574 sub cmd_compress ($$$) {
575 my ($self, $tag, $alg) = @_;
576 return "$tag BAD DEFLATE only\r\n" if uc($alg) ne "DEFLATE";
577 return "$tag BAD COMPRESS active\r\n" if $self->compressed;
579 # CRIME made TLS compression obsolete
580 # return "$tag NO [COMPRESSIONACTIVE]\r\n" if $self->tls_compressed;
582 PublicInbox::IMAPdeflate->enable($self, $tag);
587 sub cmd_starttls ($$) {
588 my ($self, $tag) = @_;
589 my $sock = $self->{sock} or return;
590 if ($sock->can('stop_SSL') || $self->compressed) {
591 return "$tag BAD TLS or compression already enabled\r\n";
593 my $opt = $self->{imapd}->{accept_tls} or
594 return "$tag BAD can not initiate TLS negotiation\r\n";
595 $self->write(\"$tag OK begin TLS negotiation now\r\n");
596 $self->{sock} = IO::Socket::SSL->start_SSL($sock, %$opt);
597 $self->requeue if PublicInbox::DS::accept_tls_step($self);
601 # for graceful shutdown in PublicInbox::Daemon:
603 my ($self, $now) = @_;
604 ($self->{rbuf} || $self->{wbuf} || $self->not_idle_long($now));
609 if (my $ibx = delete $self->{ibx}) {
610 if (my $sock = $self->{sock}) {;
611 $ibx->unsubscribe_unlock(fileno($sock));
614 $self->SUPER::close; # PublicInbox::DS::close
617 # we're read-only, so SELECT and EXAMINE do the same thing
619 *cmd_select = \&cmd_examine;