# Copyright (C) 2020-2021 all contributors
# License: AGPL-3.0+
#
# Each instance of this represents an IMAP client connected to
# public-inbox-imapd. Much of this was taken from NNTP, but
# further refined while experimenting on future ideas to handle
# slow storage.
#
# data notes:
#
# * NNTP article numbers are UIDs, mm->created_at is UIDVALIDITY
#
# * public-inboxes are sliced into mailboxes of 50K messages
# to not overload MUAs: $NEWSGROUP_NAME.$SLICE_INDEX
# Slices are similar in concept to v2 "epochs". Epochs
# are for the limitations of git clients, while slices are
# for the limitations of IMAP clients.
#
# * We also take advantage of slices being only 50K to store
# "UID offset" to message sequence number (MSN) mapping
# as a 50K uint16_t array (via pack("S*", ...)). "UID offset"
# is the offset from {uid_base} which determines the start of
# the mailbox slice.
#
# fields:
# imapd: PublicInbox::IMAPD ref
# ibx: PublicInbox::Inbox ref
# long_cb: long_response private data
# uid_base: base UID for mailbox slice (0-based)
# -login_tag: IMAP TAG for LOGIN
# -idle_tag: IMAP response tag for IDLE
# uo2m: UID-to-MSN mapping
package PublicInbox::IMAP;
use strict;
use parent qw(PublicInbox::DS);
use PublicInbox::Eml;
use PublicInbox::EmlContentFoo qw(parse_content_disposition);
use PublicInbox::DS qw(now);
use PublicInbox::Syscall qw(EPOLLIN EPOLLONESHOT);
use PublicInbox::GitAsyncCat;
use Text::ParseWords qw(parse_line);
use Errno qw(EAGAIN);
use PublicInbox::IMAPsearchqp;
my $Address;
for my $mod (qw(Email::Address::XS Mail::Address)) {
eval "require $mod" or next;
$Address = $mod and last;
}
die "neither Email::Address::XS nor Mail::Address loaded: $@" if !$Address;
sub LINE_MAX () { 8000 } # RFC 2683 3.2.1.5
# Changing UID_SLICE will cause grief for clients which cache.
# This also needs to be <64K: we pack it into a uint16_t
# for long_response UID (offset) => MSN mappings
sub UID_SLICE () { 50_000 }
# these values area also used for sorting
sub NEED_SMSG () { 1 }
sub NEED_BLOB () { NEED_SMSG|2 }
sub CRLF_BREF () { 4 }
sub EML_HDR () { 8 }
sub CRLF_HDR () { 16 }
sub EML_BDY () { 32 }
sub CRLF_BDY () { 64 }
my $OP_EML_NEW = [ EML_HDR - 1, \&op_eml_new ];
my $OP_CRLF_BREF = [ CRLF_BREF, \&op_crlf_bref ];
my $OP_CRLF_HDR = [ CRLF_HDR, \&op_crlf_hdr ];
my $OP_CRLF_BDY = [ CRLF_BDY, \&op_crlf_bdy ];
my %FETCH_NEED = (
'BODY[HEADER]' => [ NEED_BLOB|EML_HDR|CRLF_HDR, \&emit_rfc822_header ],
'BODY[TEXT]' => [ NEED_BLOB|EML_BDY|CRLF_BDY, \&emit_rfc822_text ],
'BODY[]' => [ NEED_BLOB|CRLF_BREF, \&emit_rfc822 ],
'RFC822.HEADER' => [ NEED_BLOB|EML_HDR|CRLF_HDR, \&emit_rfc822_header ],
'RFC822.TEXT' => [ NEED_BLOB|EML_BDY|CRLF_BDY, \&emit_rfc822_text ],
'RFC822.SIZE' => [ NEED_SMSG, \&emit_rfc822_size ],
RFC822 => [ NEED_BLOB|CRLF_BREF, \&emit_rfc822 ],
BODY => [ NEED_BLOB|EML_HDR|EML_BDY, \&emit_body ],
BODYSTRUCTURE => [ NEED_BLOB|EML_HDR|EML_BDY, \&emit_bodystructure ],
ENVELOPE => [ NEED_BLOB|EML_HDR, \&emit_envelope ],
FLAGS => [ 0, \&emit_flags ],
INTERNALDATE => [ NEED_SMSG, \&emit_internaldate ],
);
my %FETCH_ATT = map { $_ => [ $_ ] } keys %FETCH_NEED;
# aliases (RFC 3501 section 6.4.5)
$FETCH_ATT{FAST} = [ qw(FLAGS INTERNALDATE RFC822.SIZE) ];
$FETCH_ATT{ALL} = [ @{$FETCH_ATT{FAST}}, 'ENVELOPE' ];
$FETCH_ATT{FULL} = [ @{$FETCH_ATT{ALL}}, 'BODY' ];
for my $att (keys %FETCH_ATT) {
my %h = map { $_ => $FETCH_NEED{$_} } @{$FETCH_ATT{$att}};
$FETCH_ATT{$att} = \%h;
}
undef %FETCH_NEED;
my $valid_range = '[0-9]+|[0-9]+:[0-9]+|[0-9]+:\*';
$valid_range = qr/\A(?:$valid_range)(?:,(?:$valid_range))*\z/;
sub greet ($) {
my ($self) = @_;
my $capa = capa($self);
$self->write(\"* OK [$capa] public-inbox-imapd ready\r\n");
}
sub new ($$$) {
my ($class, $sock, $imapd) = @_;
my $self = bless { imapd => $imapd }, 'PublicInbox::IMAP_preauth';
my $ev = EPOLLIN;
my $wbuf;
if ($sock->can('accept_SSL') && !$sock->accept_SSL) {
return CORE::close($sock) if $! != EAGAIN;
$ev = PublicInbox::TLS::epollbit() or return CORE::close($sock);
$wbuf = [ \&PublicInbox::DS::accept_tls_step, \&greet ];
}
$self->SUPER::new($sock, $ev | EPOLLONESHOT);
if ($wbuf) {
$self->{wbuf} = $wbuf;
} else {
greet($self);
}
$self;
}
sub logged_in { 1 }
sub capa ($) {
my ($self) = @_;
# dovecot advertises IDLE pre-login; perhaps because some clients
# depend on it, so we'll do the same
my $capa = 'CAPABILITY IMAP4rev1 IDLE';
if ($self->logged_in) {
$capa .= ' COMPRESS=DEFLATE';
} else {
if (!($self->{sock} // $self)->can('accept_SSL') &&
$self->{imapd}->{accept_tls}) {
$capa .= ' STARTTLS';
}
$capa .= ' AUTH=ANONYMOUS';
}
}
sub login_success ($$) {
my ($self, $tag) = @_;
bless $self, 'PublicInbox::IMAP';
my $capa = capa($self);
"$tag OK [$capa] Logged in\r\n";
}
sub auth_challenge_ok ($) {
my ($self) = @_;
my $tag = delete($self->{-login_tag}) or return;
login_success($self, $tag);
}
sub cmd_login ($$$$) {
my ($self, $tag) = @_; # ignore ($user, $password) = ($_[2], $_[3])
login_success($self, $tag);
}
sub cmd_close ($$) {
my ($self, $tag) = @_;
delete @$self{qw(uid_base uo2m)};
delete $self->{ibx} ? "$tag OK Close done\r\n"
: "$tag BAD No mailbox\r\n";
}
sub cmd_logout ($$) {
my ($self, $tag) = @_;
delete $self->{-idle_tag};
$self->write(\"* BYE logging out\r\n$tag OK Logout done\r\n");
$self->shutdn; # PublicInbox::DS::shutdn
undef;
}
sub cmd_authenticate ($$$) {
my ($self, $tag) = @_; # $method = $_[2], should be "ANONYMOUS"
$self->{-login_tag} = $tag;
"+\r\n"; # challenge
}
sub cmd_capability ($$) {
my ($self, $tag) = @_;
'* '.capa($self)."\r\n$tag OK Capability done\r\n";
}
# uo2m: UID Offset to MSN, this is an arrayref by default,
# but uo2m_hibernate can compact and deduplicate it
sub uo2m_ary_new ($;$) {
my ($self, $exists) = @_;
my $ub = $self->{uid_base};
my $uids = $self->{ibx}->over(1)->uid_range($ub + 1, $ub + UID_SLICE);
# convert UIDs to offsets from {base}
my @tmp; # [$UID_OFFSET] => $MSN
my $msn = 0;
++$ub;
$tmp[$_ - $ub] = ++$msn for @$uids;
$$exists = $msn if $exists;
\@tmp;
}
# changes UID-offset-to-MSN mapping into a deduplicated scalar:
# uint16_t uo2m[UID_SLICE].
# May be swapped out for idle clients if THP is disabled.
sub uo2m_hibernate ($) {
my ($self) = @_;
ref(my $uo2m = $self->{uo2m}) or return;
my %dedupe = ( uo2m_pack($uo2m) => undef );
$self->{uo2m} = (keys(%dedupe))[0];
undef;
}
sub uo2m_last_uid ($) {
my ($self) = @_;
defined(my $uo2m = $self->{uo2m}) or die 'BUG: uo2m_last_uid w/o {uo2m}';
(ref($uo2m) ? @$uo2m : (length($uo2m) >> 1)) + $self->{uid_base};
}
sub uo2m_pack ($) {
# $_[0] is an arrayref of MSNs, it may have undef gaps if there
# are gaps in the corresponding UIDs: [ msn1, msn2, undef, msn3 ]
no warnings 'uninitialized';
pack('S*', @{$_[0]});
}
# extend {uo2m} to account for new messages which arrived since
# {uo2m} was created.
sub uo2m_extend ($$;$) {
my ($self, $new_uid_max) = @_;
defined(my $uo2m = $self->{uo2m}) or
return($self->{uo2m} = uo2m_ary_new($self));
my $beg = uo2m_last_uid($self); # last UID we've learned
return $uo2m if $beg >= $new_uid_max; # fast path
# need to extend the current range:
my $base = $self->{uid_base};
++$beg;
my $uids = $self->{ibx}->over(1)->uid_range($beg, $base + UID_SLICE);
return $uo2m if !scalar(@$uids);
my @tmp; # [$UID_OFFSET] => $MSN
my $write_method = $_[2] // 'msg_more';
if (ref($uo2m)) {
my $msn = $uo2m->[-1];
$tmp[$_ - $beg] = ++$msn for @$uids;
$self->$write_method("* $msn EXISTS\r\n");
push @$uo2m, @tmp;
$uo2m;
} else {
my $msn = unpack('S', substr($uo2m, -2, 2));
$tmp[$_ - $beg] = ++$msn for @$uids;
$self->$write_method("* $msn EXISTS\r\n");
$uo2m .= uo2m_pack(\@tmp);
my %dedupe = ($uo2m => undef);
$self->{uo2m} = (keys %dedupe)[0];
}
}
sub cmd_noop ($$) {
my ($self, $tag) = @_;
defined($self->{uid_base}) and
uo2m_extend($self, $self->{uid_base} + UID_SLICE);
\"$tag OK Noop done\r\n";
}
# the flexible version which works on scalars and array refs.
# Must call uo2m_extend before this
sub uid2msn ($$) {
my ($self, $uid) = @_;
my $uo2m = $self->{uo2m};
my $off = $uid - $self->{uid_base} - 1;
ref($uo2m) ? $uo2m->[$off] : unpack('S', substr($uo2m, $off << 1, 2));
}
# returns an arrayref of UIDs, so MSNs can be translated to UIDs via:
# $msn2uid->[$MSN-1] => $UID. The result of this is always ephemeral
# and does not live beyond the event loop.
sub msn2uid ($) {
my ($self) = @_;
my $base = $self->{uid_base};
my $uo2m = uo2m_extend($self, $base + UID_SLICE);
$uo2m = [ unpack('S*', $uo2m) ] if !ref($uo2m);
my $uo = 0;
my @msn2uid;
for my $msn (@$uo2m) {
++$uo;
$msn2uid[$msn - 1] = $uo + $base if $msn;
}
\@msn2uid;
}
# converts a set of message sequence numbers in requests to UIDs:
sub msn_to_uid_range ($$) {
my $msn2uid = $_[0];
$_[1] =~ s!([0-9]+)!$msn2uid->[$1 - 1] // ($msn2uid->[-1] // 0 + 1)!sge;
}
# called by PublicInbox::InboxIdle
sub on_inbox_unlock {
my ($self, $ibx) = @_;
my $uid_end = $self->{uid_base} + UID_SLICE;
uo2m_extend($self, $uid_end, 'write');
my $new = uo2m_last_uid($self);
if ($new == $uid_end) { # max exceeded $uid_end
# continue idling w/o inotify
my $sock = $self->{sock} or return;
$ibx->unsubscribe_unlock(fileno($sock));
}
}
# called every minute or so by PublicInbox::DS::later
my $IDLERS; # fileno($obj->{sock}) => PublicInbox::IMAP
sub idle_tick_all {
my $old = $IDLERS;
$IDLERS = undef;
for my $i (values %$old) {
next if ($i->{wbuf} || !exists($i->{-idle_tag}));
$IDLERS->{fileno($i->{sock})} = $i;
$i->write(\"* OK Still here\r\n");
}
$IDLERS and
PublicInbox::DS::add_uniq_timer('idle', 60, \&idle_tick_all);
}
sub cmd_idle ($$) {
my ($self, $tag) = @_;
# IDLE seems allowed by dovecot w/o a mailbox selected *shrug*
my $ibx = $self->{ibx} or return "$tag BAD no mailbox selected\r\n";
my $uid_end = $self->{uid_base} + UID_SLICE;
uo2m_extend($self, $uid_end);
my $sock = $self->{sock} or return;
my $fd = fileno($sock);
$self->{-idle_tag} = $tag;
# only do inotify on most recent slice
if ($ibx->over(1)->max < $uid_end) {
$ibx->subscribe_unlock($fd, $self);
$self->{imapd}->idler_start;
}
PublicInbox::DS::add_uniq_timer('idle', 60, \&idle_tick_all);
$IDLERS->{$fd} = $self;
\"+ idling\r\n"
}
sub stop_idle ($$) {
my ($self, $ibx) = @_;
my $sock = $self->{sock} or return;
my $fd = fileno($sock);
delete $IDLERS->{$fd};
$ibx->unsubscribe_unlock($fd);
}
sub idle_done ($$) {
my ($self, $tag) = @_; # $tag is "DONE" (case-insensitive)
defined(my $idle_tag = delete $self->{-idle_tag}) or
return "$tag BAD not idle\r\n";
my $ibx = $self->{ibx} or do {
warn "BUG: idle_tag set w/o inbox";
return "$tag BAD internal bug\r\n";
};
stop_idle($self, $ibx);
"$idle_tag OK Idle done\r\n";
}
sub ensure_slices_exist ($$$) {
my ($imapd, $ibx, $max) = @_;
defined(my $mb_top = $ibx->{newsgroup}) or return;
my $mailboxes = $imapd->{mailboxes};
my @created;
for (my $i = int($max/UID_SLICE); $i >= 0; --$i) {
my $sub_mailbox = "$mb_top.$i";
last if exists $mailboxes->{$sub_mailbox};
$mailboxes->{$sub_mailbox} = $ibx;
$sub_mailbox =~ s/\Ainbox\./INBOX./i; # more familiar to users
push @created, $sub_mailbox;
}
return unless @created;
my $l = $imapd->{mailboxlist} or return;
push @$l, map { qq[* LIST (\\HasNoChildren) "." $_\r\n] } @created;
}
sub inbox_lookup ($$;$) {
my ($self, $mailbox, $examine) = @_;
my ($ibx, $exists, $uidmax, $uid_base) = (undef, 0, 0, 0);
$mailbox = lc $mailbox;
$ibx = $self->{imapd}->{mailboxes}->{$mailbox} or return;
my $over = $ibx->over(1);
if ($over != $ibx) { # not a dummy
$mailbox =~ /\.([0-9]+)\z/ or
die "BUG: unexpected dummy mailbox: $mailbox\n";
$uid_base = $1 * UID_SLICE;
$uidmax = $ibx->mm->num_highwater // 0;
if ($examine) {
$self->{uid_base} = $uid_base;
$self->{ibx} = $ibx;
$self->{uo2m} = uo2m_ary_new($self, \$exists);
} else {
$exists = $over->imap_exists;
}
ensure_slices_exist($self->{imapd}, $ibx, $over->max);
} else {
if ($examine) {
$self->{uid_base} = $uid_base;
$self->{ibx} = $ibx;
delete $self->{uo2m};
}
# if "INBOX.foo.bar" is selected and "INBOX.foo.bar.0",
# check for new UID ranges (e.g. "INBOX.foo.bar.1")
if (my $z = $self->{imapd}->{mailboxes}->{"$mailbox.0"}) {
ensure_slices_exist($self->{imapd}, $z,
$z->over(1)->max);
}
}
($ibx, $exists, $uidmax + 1, $uid_base);
}
sub cmd_examine ($$$) {
my ($self, $tag, $mailbox) = @_;
# XXX: do we need this? RFC 5162/7162
my $ret = $self->{ibx} ? "* OK [CLOSED] previous closed\r\n" : '';
my ($ibx, $exists, $uidnext, $base) = inbox_lookup($self, $mailbox, 1);
return "$tag NO Mailbox doesn't exist: $mailbox\r\n" if !$ibx;
$ret .= <{uidvalidity}]\r
$tag OK [READ-ONLY] EXAMINE/SELECT done\r
EOF
}
sub _esc ($) {
my ($v) = @_;
if (!defined($v)) {
'NIL';
} elsif ($v =~ /[{"\r\n%*\\\[]/) { # literal string
'{' . length($v) . "}\r\n" . $v;
} else { # quoted string
qq{"$v"}
}
}
sub addr_envelope ($$;$) {
my ($eml, $x, $y) = @_;
my $v = $eml->header_raw($x) //
($y ? $eml->header_raw($y) : undef) // return 'NIL';
my @x = $Address->parse($v) or return 'NIL';
'(' . join('',
map { '(' . join(' ',
_esc($_->name), 'NIL',
_esc($_->user), _esc($_->host)
) . ')'
} @x) .
')';
}
sub eml_envelope ($) {
my ($eml) = @_;
'(' . join(' ',
_esc($eml->header_raw('Date')),
_esc($eml->header_raw('Subject')),
addr_envelope($eml, 'From'),
addr_envelope($eml, 'Sender', 'From'),
addr_envelope($eml, 'Reply-To', 'From'),
addr_envelope($eml, 'To'),
addr_envelope($eml, 'Cc'),
addr_envelope($eml, 'Bcc'),
_esc($eml->header_raw('In-Reply-To')),
_esc($eml->header_raw('Message-ID')),
) . ')';
}
sub _esc_hash ($) {
my ($hash) = @_;
if ($hash && scalar keys %$hash) {
$hash = [ %$hash ]; # flatten hash into 1-dimensional array
'(' . join(' ', map { _esc($_) } @$hash) . ')';
} else {
'NIL';
}
}
sub body_disposition ($) {
my ($eml) = @_;
my $cd = $eml->header_raw('Content-Disposition') or return 'NIL';
$cd = parse_content_disposition($cd);
my $buf = '('._esc($cd->{type});
$buf .= ' ' . _esc_hash($cd->{attributes});
$buf .= ')';
}
sub body_leaf ($$;$) {
my ($eml, $structure, $hold) = @_;
my $buf = '';
$eml->{is_submsg} and # parent was a message/(rfc822|news|global)
$buf .= eml_envelope($eml). ' ';
my $ct = $eml->ct;
$buf .= '('._esc($ct->{type}).' ';
$buf .= _esc($ct->{subtype});
$buf .= ' ' . _esc_hash($ct->{attributes});
$buf .= ' ' . _esc($eml->header_raw('Content-ID'));
$buf .= ' ' . _esc($eml->header_raw('Content-Description'));
my $cte = $eml->header_raw('Content-Transfer-Encoding') // '7bit';
$buf .= ' ' . _esc($cte);
$buf .= ' ' . $eml->{imap_body_len};
$buf .= ' '.($eml->body_raw =~ tr/\n/\n/) if lc($ct->{type}) eq 'text';
# for message/(rfc822|global|news), $hold[0] should have envelope
$buf .= ' ' . (@$hold ? join('', @$hold) : 'NIL') if $hold;
if ($structure) {
$buf .= ' '._esc($eml->header_raw('Content-MD5'));
$buf .= ' '. body_disposition($eml);
$buf .= ' '._esc($eml->header_raw('Content-Language'));
$buf .= ' '._esc($eml->header_raw('Content-Location'));
}
$buf .= ')';
}
sub body_parent ($$$) {
my ($eml, $structure, $hold) = @_;
my $ct = $eml->ct;
my $type = lc($ct->{type});
if ($type eq 'multipart') {
my $buf = '(';
$buf .= @$hold ? join('', @$hold) : 'NIL';
$buf .= ' '._esc($ct->{subtype});
if ($structure) {
$buf .= ' '._esc_hash($ct->{attributes});
$buf .= ' '.body_disposition($eml);
$buf .= ' '._esc($eml->header_raw('Content-Language'));
$buf .= ' '._esc($eml->header_raw('Content-Location'));
}
$buf .= ')';
@$hold = ($buf);
} else { # message/(rfc822|global|news)
@$hold = (body_leaf($eml, $structure, $hold));
}
}
# this is gross, but we need to process the parent part AFTER
# the child parts are done
sub bodystructure_prep {
my ($p, $q) = @_;
my ($eml, $depth) = @$p; # ignore idx
# set length here, as $eml->{bdy} gets deleted for message/rfc822
$eml->{imap_body_len} = length($eml->body_raw);
push @$q, $eml, $depth;
}
# for FETCH BODY and FETCH BODYSTRUCTURE
sub fetch_body ($;$) {
my ($eml, $structure) = @_;
my @q;
$eml->each_part(\&bodystructure_prep, \@q, 0, 1);
my $cur_depth = 0;
my @hold;
do {
my ($part, $depth) = splice(@q, -2);
my $is_mp_parent = $depth == ($cur_depth - 1);
$cur_depth = $depth;
if ($is_mp_parent) {
body_parent($part, $structure, \@hold);
} else {
unshift @hold, body_leaf($part, $structure);
}
} while (@q);
join('', @hold);
}
sub requeue_once ($) {
my ($self) = @_;
# COMPRESS users all share the same DEFLATE context.
# Flush it here to ensure clients don't see
# each other's data
$self->zflush;
# no recursion, schedule another call ASAP,
# but only after all pending writes are done.
# autovivify wbuf:
my $new_size = push(@{$self->{wbuf}}, \&long_step);
# wbuf may be populated by $cb, no need to rearm if so:
$self->requeue if $new_size == 1;
}
sub fetch_run_ops {
my ($self, $smsg, $bref, $ops, $partial) = @_;
my $uid = $smsg->{num};
$self->msg_more('* '.uid2msn($self, $uid)." FETCH (UID $uid");
my ($eml, $k);
for (my $i = 0; $i < @$ops;) {
$k = $ops->[$i++];
$ops->[$i++]->($self, $k, $smsg, $bref, $eml);
}
partial_emit($self, $partial, $eml) if $partial;
$self->msg_more(")\r\n");
}
sub fetch_blob_cb { # called by git->cat_async via ibx_async_cat
my ($bref, $oid, $type, $size, $fetch_arg) = @_;
my ($self, undef, $msgs, $range_info, $ops, $partial) = @$fetch_arg;
my $ibx = $self->{ibx} or return $self->close; # client disconnected
my $smsg = shift @$msgs or die 'BUG: no smsg';
if (!defined($oid)) {
# it's possible to have TOCTOU if an admin runs
# public-inbox-(edit|purge), just move onto the next message
warn "E: $smsg->{blob} missing in $ibx->{inboxdir}\n";
return requeue_once($self);
} else {
$smsg->{blob} eq $oid or die "BUG: $smsg->{blob} != $oid";
}
my $pre;
if (!$self->{wbuf} && (my $nxt = $msgs->[0])) {
$pre = ibx_async_prefetch($ibx, $nxt->{blob},
\&fetch_blob_cb, $fetch_arg);
}
fetch_run_ops($self, $smsg, $bref, $ops, $partial);
$pre ? $self->zflush : requeue_once($self);
}
sub emit_rfc822 {
my ($self, $k, undef, $bref) = @_;
$self->msg_more(" $k {" . length($$bref)."}\r\n");
$self->msg_more($$bref);
}
# Mail::IMAPClient::message_string cares about this by default,
# (->Ignoresizeerrors attribute). Admins are encouraged to
# --reindex for IMAP support, anyways.
sub emit_rfc822_size {
my ($self, $k, $smsg) = @_;
$self->msg_more(' RFC822.SIZE ' . $smsg->{bytes});
}
sub emit_internaldate {
my ($self, undef, $smsg) = @_;
$self->msg_more(' INTERNALDATE "'.$smsg->internaldate.'"');
}
sub emit_flags { $_[0]->msg_more(' FLAGS ()') }
sub emit_envelope {
my ($self, undef, undef, undef, $eml) = @_;
$self->msg_more(' ENVELOPE '.eml_envelope($eml));
}
sub emit_rfc822_header {
my ($self, $k, undef, undef, $eml) = @_;
$self->msg_more(" $k {".length(${$eml->{hdr}})."}\r\n");
$self->msg_more(${$eml->{hdr}});
}
# n.b. this is sorted to be after any emit_eml_new ops
sub emit_rfc822_text {
my ($self, $k, undef, $bref) = @_;
$self->msg_more(" $k {".length($$bref)."}\r\n");
$self->msg_more($$bref);
}
sub emit_bodystructure {
my ($self, undef, undef, undef, $eml) = @_;
$self->msg_more(' BODYSTRUCTURE '.fetch_body($eml, 1));
}
sub emit_body {
my ($self, undef, undef, undef, $eml) = @_;
$self->msg_more(' BODY '.fetch_body($eml));
}
# set $eml once ($_[4] == $eml, $_[3] == $bref)
sub op_eml_new { $_[4] = PublicInbox::Eml->new($_[3]) }
# s/From / fixes old bug from import (pre-a0c07cba0e5d8b6a)
sub to_crlf_full {
${$_[0]} =~ s/(?{hdr}) }
sub op_crlf_bdy { ${$_[4]->{bdy}} =~ s/(?{bdy} }
sub uid_clamp ($$$) {
my ($self, $beg, $end) = @_;
my $uid_min = $self->{uid_base} + 1;
my $uid_end = $uid_min + UID_SLICE - 1;
$$beg = $uid_min if $$beg < $uid_min;
$$end = $uid_end if $$end > $uid_end;
}
sub range_step ($$) {
my ($self, $range_csv) = @_;
my ($beg, $end, $range);
if ($$range_csv =~ s/\A([^,]+),//) {
$range = $1;
} else {
$range = $$range_csv;
$$range_csv = undef;
}
my $uid_base = $self->{uid_base};
my $uid_end = $uid_base + UID_SLICE;
if ($range =~ /\A([0-9]+):([0-9]+)\z/) {
($beg, $end) = ($1 + 0, $2 + 0);
uid_clamp($self, \$beg, \$end);
} elsif ($range =~ /\A([0-9]+):\*\z/) {
$beg = $1 + 0;
$end = $self->{ibx}->over(1)->max;
$end = $uid_end if $end > $uid_end;
$beg = $end if $beg > $end;
uid_clamp($self, \$beg, \$end);
} elsif ($range =~ /\A[0-9]+\z/) {
$beg = $end = $range + 0;
# just let the caller do an out-of-range query if a single
# UID is out-of-range
++$beg if ($beg <= $uid_base || $end > $uid_end);
} else {
return 'BAD fetch range';
}
[ $beg, $end, $$range_csv ];
}
sub refill_range ($$$) {
my ($self, $msgs, $range_info) = @_;
my ($beg, $end, $range_csv) = @$range_info;
if (scalar(@$msgs = @{$self->{ibx}->over(1)->query_xover($beg, $end)})){
$range_info->[0] = $msgs->[-1]->{num} + 1;
return;
}
return 'OK Fetch done' if !$range_csv;
my $next_range = range_step($self, \$range_csv);
return $next_range if !ref($next_range); # error
@$range_info = @$next_range;
undef; # keep looping
}
sub fetch_blob { # long_response
my ($self, $tag, $msgs, $range_info, $ops, $partial) = @_;
while (!@$msgs) { # rare
if (my $end = refill_range($self, $msgs, $range_info)) {
$self->write(\"$tag $end\r\n");
return;
}
}
uo2m_extend($self, $msgs->[-1]->{num});
ibx_async_cat($self->{ibx}, $msgs->[0]->{blob},
\&fetch_blob_cb, \@_);
}
sub fetch_smsg { # long_response
my ($self, $tag, $msgs, $range_info, $ops) = @_;
while (!@$msgs) { # rare
if (my $end = refill_range($self, $msgs, $range_info)) {
$self->write(\"$tag $end\r\n");
return;
}
}
uo2m_extend($self, $msgs->[-1]->{num});
fetch_run_ops($self, $_, undef, $ops) for @$msgs;
@$msgs = ();
1; # more
}
sub refill_uids ($$$;$) {
my ($self, $uids, $range_info, $sql) = @_;
my ($beg, $end, $range_csv) = @$range_info;
my $over = $self->{ibx}->over(1);
while (1) {
if (scalar(@$uids = @{$over->uid_range($beg, $end, $sql)})) {
$range_info->[0] = $uids->[-1] + 1; # update $beg
return;
} elsif (!$range_csv) {
return 0;
} else {
my $next_range = range_step($self, \$range_csv);
return $next_range if !ref($next_range); # error
($beg, $end, $range_csv) = @$range_info = @$next_range;
# continue looping
}
}
}
sub fetch_uid { # long_response
my ($self, $tag, $uids, $range_info, $ops) = @_;
if (defined(my $err = refill_uids($self, $uids, $range_info))) {
$err ||= 'OK Fetch done';
$self->write("$tag $err\r\n");
return;
}
my $adj = $self->{uid_base} + 1;
my $uo2m = uo2m_extend($self, $uids->[-1]);
$uo2m = [ unpack('S*', $uo2m) ] if !ref($uo2m);
my ($i, $k);
for (@$uids) {
$self->msg_more("* $uo2m->[$_ - $adj] FETCH (UID $_");
for ($i = 0; $i < @$ops;) {
$k = $ops->[$i++];
$ops->[$i++]->($self, $k);
}
$self->msg_more(")\r\n");
}
@$uids = ();
1; # more
}
sub cmd_status ($$$;@) {
my ($self, $tag, $mailbox, @items) = @_;
return "$tag BAD no items\r\n" if !scalar(@items);
($items[0] !~ s/\A\(//s || $items[-1] !~ s/\)\z//s) and
return "$tag BAD invalid args\r\n";
my ($ibx, $exists, $uidnext) = inbox_lookup($self, $mailbox);
return "$tag NO Mailbox doesn't exist: $mailbox\r\n" if !$ibx;
my @it;
for my $it (@items) {
$it = uc($it);
push @it, $it;
if ($it =~ /\A(?:MESSAGES|UNSEEN|RECENT)\z/) {
push @it, $exists;
} elsif ($it eq 'UIDNEXT') {
push @it, $uidnext;
} elsif ($it eq 'UIDVALIDITY') {
push @it, $ibx->{uidvalidity};
} else {
return "$tag BAD invalid item\r\n";
}
}
return "$tag BAD no items\r\n" if !@it;
"* STATUS $mailbox (".join(' ', @it).")\r\n" .
"$tag OK Status done\r\n";
}
my %patmap = ('*' => '.*', '%' => '[^\.]*');
sub cmd_list ($$$$) {
my ($self, $tag, $refname, $wildcard) = @_;
my $l = $self->{imapd}->{mailboxlist};
if ($refname eq '' && $wildcard eq '') {
# request for hierarchy delimiter
$l = [ qq[* LIST (\\Noselect) "." ""\r\n] ];
} elsif ($refname ne '' || $wildcard ne '*') {
$wildcard =~ s!([^a-z0-9_])!$patmap{$1} // "\Q$1"!egi;
$l = [ grep(/ \Q$refname\E$wildcard\r\n\z/is, @$l) ];
}
\(join('', @$l, "$tag OK List done\r\n"));
}
sub cmd_lsub ($$$$) {
my (undef, $tag) = @_; # same args as cmd_list
"$tag OK Lsub done\r\n";
}
sub eml_index_offs_i { # PublicInbox::Eml::each_part callback
my ($p, $all) = @_;
my ($eml, undef, $idx) = @$p;
if ($idx && lc($eml->ct->{type}) eq 'multipart') {
$eml->{imap_bdy} = $eml->{bdy} // \'';
}
$all->{$idx} = $eml; # $idx => Eml
}
# prepares an index for BODY[$SECTION_IDX] fetches
sub eml_body_idx ($$) {
my ($eml, $section_idx) = @_;
my $idx = $eml->{imap_all_parts} // do {
my $all = {};
$eml->each_part(\&eml_index_offs_i, $all, 0, 1);
# top-level of multipart, BODY[0] not allowed (nz-number)
delete $all->{0};
$eml->{imap_all_parts} = $all;
};
$idx->{$section_idx};
}
# BODY[($SECTION_IDX)?(.$SECTION_NAME)?]<$offset.$bytes>
sub partial_body {
my ($eml, $section_idx, $section_name) = @_;
if (defined $section_idx) {
$eml = eml_body_idx($eml, $section_idx) or return;
}
if (defined $section_name) {
if ($section_name eq 'MIME') {
# RFC 3501 6.4.5 states:
# The MIME part specifier MUST be prefixed
# by one or more numeric part specifiers
return unless defined $section_idx;
return $eml->header_obj->as_string . "\r\n";
}
my $bdy = $eml->{bdy} // $eml->{imap_bdy} // \'';
$eml = PublicInbox::Eml->new($$bdy);
if ($section_name eq 'TEXT') {
return $eml->body_raw;
} elsif ($section_name eq 'HEADER') {
return $eml->header_obj->as_string . "\r\n";
} else {
die "BUG: bad section_name=$section_name";
}
}
${$eml->{bdy} // $eml->{imap_bdy} // \''};
}
# similar to what's in PublicInbox::Eml::re_memo, but doesn't memoize
# to avoid OOM with malicious users
sub hdrs_regexp ($) {
my ($hdrs) = @_;
my $names = join('|', map { "\Q$_" } split(/[ \t]+/, $hdrs));
qr/^(?:$names):[ \t]*[^\n]*\r?\n # 1st line
# continuation lines:
(?:[^:\n]*?[ \t]+[^\n]*\r?\n)*
/ismx;
}
# BODY[($SECTION_IDX.)?HEADER.FIELDS.NOT ($HDRS)]<$offset.$bytes>
sub partial_hdr_not {
my ($eml, $section_idx, $hdrs_re) = @_;
if (defined $section_idx) {
$eml = eml_body_idx($eml, $section_idx) or return;
}
my $str = $eml->header_obj->as_string;
$str =~ s/$hdrs_re//g;
$str =~ s/(?
sub partial_hdr_get {
my ($eml, $section_idx, $hdrs_re) = @_;
if (defined $section_idx) {
$eml = eml_body_idx($eml, $section_idx) or return;
}
my $str = $eml->header_obj->as_string;
$str = join('', ($str =~ m/($hdrs_re)/g));
$str =~ s/(?= 0) {
my $next = shift @$want or return;
$att .= ' ' . uc($next);
}
if ($att =~ /\ABODY\[([0-9]+(?:\.[0-9]+)*)? # 1 - section_idx
(?:\.(HEADER|MIME|TEXT))? # 2 - section_name
\](?:<([0-9]+)(?:\.([0-9]+))?>)?\z/sx) { # 3, 4
$partial->{$att} = [ \&partial_body, $1, $2, $3, $4 ];
$$need |= CRLF_BREF|EML_HDR|EML_BDY;
} elsif ($att =~ /\ABODY\[(?:([0-9]+(?:\.[0-9]+)*)\.)? # 1 - section_idx
(?:HEADER\.FIELDS(\.NOT)?)\x20 # 2
\(([A-Z0-9\-\x20]+)\) # 3 - hdrs
\](?:<([0-9]+)(?:\.([0-9]+))?>)?\z/sx) { # 4 5
my $tmp = $partial->{$att} = [ $2 ? \&partial_hdr_not
: \&partial_hdr_get,
$1, undef, $4, $5 ];
$tmp->[2] = hdrs_regexp($3);
# don't emit CRLF_HDR instruction, here, partial_hdr_*
# will do CRLF conversion with only the extracted result
# and not waste time converting lines we don't care about.
$$need |= EML_HDR;
} else {
undef;
}
}
sub partial_emit ($$$) {
my ($self, $partial, $eml) = @_;
for (@$partial) {
my ($k, $cb, @args) = @$_;
my ($offset, $len) = splice(@args, -2);
# $cb is partial_body|partial_hdr_get|partial_hdr_not
my $str = $cb->($eml, @args) // '';
if (defined $offset) {
if (defined $len) {
$str = substr($str, $offset, $len);
$k =~ s/\.$len>\z/>/ or warn
"BUG: unable to remove `.$len>' from `$k'";
} else {
$str = substr($str, $offset);
$len = length($str);
}
} else {
$len = length($str);
}
$self->msg_more(" $k {$len}\r\n");
$self->msg_more($str);
}
}
sub fetch_compile ($) {
my ($want) = @_;
if ($want->[0] =~ s/\A\(//s) {
$want->[-1] =~ s/\)\z//s or return 'BAD no rparen';
}
my (%partial, %seen, @op);
my $need = 0;
while (defined(my $att = shift @$want)) {
$att = uc($att);
next if $att eq 'UID'; # always returned
$att =~ s/\ABODY\.PEEK\[/BODY\[/; # we're read-only
my $x = $FETCH_ATT{$att};
if ($x) {
while (my ($k, $fl_cb) = each %$x) {
next if $seen{$k}++;
$need |= $fl_cb->[0];
push @op, [ @$fl_cb, $k ];
}
} elsif (!partial_prepare(\$need, \%partial, $want, $att)) {
return "BAD param: $att";
}
}
my @r;
# stabilize partial order for consistency and ease-of-debugging:
if (scalar keys %partial) {
$need |= NEED_BLOB;
$r[2] = [ map { [ $_, @{$partial{$_}} ] } sort keys %partial ];
}
push @op, $OP_EML_NEW if ($need & (EML_HDR|EML_BDY));
# do we need CRLF conversion?
if ($need & CRLF_BREF) {
push @op, $OP_CRLF_BREF;
} elsif (my $crlf = ($need & (CRLF_HDR|CRLF_BDY))) {
if ($crlf == (CRLF_HDR|CRLF_BDY)) {
push @op, $OP_CRLF_BREF;
} elsif ($need & CRLF_HDR) {
push @op, $OP_CRLF_HDR;
} else {
push @op, $OP_CRLF_BDY;
}
}
$r[0] = $need & NEED_BLOB ? \&fetch_blob :
($need & NEED_SMSG ? \&fetch_smsg : \&fetch_uid);
# r[1] = [ $key1, $cb1, $key2, $cb2, ... ]
use sort 'stable'; # makes output more consistent
$r[1] = [ map { ($_->[2], $_->[1]) } sort { $a->[0] <=> $b->[0] } @op ];
@r;
}
sub cmd_uid_fetch ($$$$;@) {
my ($self, $tag, $range_csv, @want) = @_;
my $ibx = $self->{ibx} or return "$tag BAD No mailbox selected\r\n";
my ($cb, $ops, $partial) = fetch_compile(\@want);
return "$tag $cb\r\n" unless $ops;
# cb is one of fetch_blob, fetch_smsg, fetch_uid
$range_csv = 'bad' if $range_csv !~ $valid_range;
my $range_info = range_step($self, \$range_csv);
return "$tag $range_info\r\n" if !ref($range_info);
uo2m_hibernate($self) if $cb == \&fetch_blob; # slow, save RAM
long_response($self, $cb, $tag, [], $range_info, $ops, $partial);
}
sub cmd_fetch ($$$$;@) {
my ($self, $tag, $range_csv, @want) = @_;
my $ibx = $self->{ibx} or return "$tag BAD No mailbox selected\r\n";
my ($cb, $ops, $partial) = fetch_compile(\@want);
return "$tag $cb\r\n" unless $ops;
# cb is one of fetch_blob, fetch_smsg, fetch_uid
$range_csv = 'bad' if $range_csv !~ $valid_range;
msn_to_uid_range(msn2uid($self), $range_csv);
my $range_info = range_step($self, \$range_csv);
return "$tag $range_info\r\n" if !ref($range_info);
uo2m_hibernate($self) if $cb == \&fetch_blob; # slow, save RAM
long_response($self, $cb, $tag, [], $range_info, $ops, $partial);
}
sub msn_convert ($$) {
my ($self, $uids) = @_;
my $adj = $self->{uid_base} + 1;
my $uo2m = uo2m_extend($self, $uids->[-1]);
$uo2m = [ unpack('S*', $uo2m) ] if !ref($uo2m);
$_ = $uo2m->[$_ - $adj] for @$uids;
}
sub search_uid_range { # long_response
my ($self, $tag, $sql, $range_info, $want_msn) = @_;
my $uids = [];
if (defined(my $err = refill_uids($self, $uids, $range_info, $sql))) {
$err ||= 'OK Search done';
$self->write("\r\n$tag $err\r\n");
return;
}
msn_convert($self, $uids) if $want_msn;
$self->msg_more(join(' ', '', @$uids));
1; # more
}
sub parse_imap_query ($$) {
my ($self, $query) = @_;
my $q = PublicInbox::IMAPsearchqp::parse($self, $query);
if (ref($q)) {
my $max = $self->{ibx}->over(1)->max;
my $beg = 1;
uid_clamp($self, \$beg, \$max);
$q->{range_info} = [ $beg, $max ];
}
$q;
}
sub search_common {
my ($self, $tag, $query, $want_msn) = @_;
my $ibx = $self->{ibx} or return "$tag BAD No mailbox selected\r\n";
my $q = parse_imap_query($self, $query);
return "$tag $q\r\n" if !ref($q);
my ($sql, $range_info) = delete @$q{qw(sql range_info)};
if (!scalar(keys %$q)) { # overview.sqlite3
$self->msg_more('* SEARCH');
long_response($self, \&search_uid_range,
$tag, $sql, $range_info, $want_msn);
} elsif ($q = $q->{xap}) {
my $srch = $self->{ibx}->isrch or
return "$tag BAD search not available for mailbox\r\n";
my $opt = {
relevance => -1,
limit => UID_SLICE,
uid_range => $range_info
};
my $mset = $srch->mset($q, $opt);
my $uids = $srch->mset_to_artnums($mset, $opt);
msn_convert($self, $uids) if scalar(@$uids) && $want_msn;
"* SEARCH @$uids\r\n$tag OK Search done\r\n";
} else {
"$tag BAD Error\r\n";
}
}
sub cmd_uid_search ($$$) {
my ($self, $tag, $query) = @_;
search_common($self, $tag, $query);
}
sub cmd_search ($$$;) {
my ($self, $tag, $query) = @_;
search_common($self, $tag, $query, 1);
}
sub args_ok ($$) { # duplicated from PublicInbox::NNTP
my ($cb, $argc) = @_;
my $tot = prototype $cb;
my ($nreq, undef) = split(';', $tot);
$nreq = ($nreq =~ tr/$//) - 1;
$tot = ($tot =~ tr/$//) - 1;
($argc <= $tot && $argc >= $nreq);
}
# returns 1 if we can continue, 0 if not due to buffered writes or disconnect
sub process_line ($$) {
my ($self, $l) = @_;
# TODO: IMAP allows literals for big requests to upload messages
# (which we don't support) but maybe some big search queries use it.
# RFC 3501 9 (2) doesn't permit TAB or multiple SP
my ($tag, $req, @args) = parse_line('[ \t]+', 0, $l);
pop(@args) if (@args && !defined($args[-1]));
if (@args && uc($req) eq 'UID') {
$req .= "_".(shift @args);
}
my $res = eval {
if (defined(my $idle_tag = $self->{-idle_tag})) {
(uc($tag // '') eq 'DONE' && !defined($req)) ?
idle_done($self, $tag) :
"$idle_tag BAD expected DONE\r\n";
} elsif (my $cmd = $self->can('cmd_'.lc($req // ''))) {
if ($cmd == \&cmd_uid_search || $cmd == \&cmd_search) {
# preserve user-supplied quotes for search
(undef, @args) = split(/ search /i, $l, 2);
}
$cmd->($self, $tag, @args);
} else { # this is weird
auth_challenge_ok($self) //
($tag // '*') .
' BAD Error in IMAP command '.
($req // '(???)').
": Unknown command\r\n";
}
};
my $err = $@;
if ($err && $self->{sock}) {
$l =~ s/\r?\n//s;
err($self, 'error from: %s (%s)', $l, $err);
$tag //= '*';
$res = "$tag BAD program fault - command not performed\r\n";
}
return 0 unless defined $res;
$self->write($res);
}
sub long_step {
my ($self) = @_;
# wbuf is unset or empty, here; {long} may add to it
my ($fd, $cb, $t0, @args) = @{$self->{long_cb}};
my $more = eval { $cb->($self, @args) };
if ($@ || !$self->{sock}) { # something bad happened...
delete $self->{long_cb};
my $elapsed = now() - $t0;
if ($@) {
err($self,
"%s during long response[$fd] - %0.6f",
$@, $elapsed);
}
out($self, " deferred[$fd] aborted - %0.6f", $elapsed);
$self->close;
} elsif ($more) { # $self->{wbuf}:
# control passed to ibx_async_cat if $more == \undef
requeue_once($self) if !ref($more);
} else { # all done!
delete $self->{long_cb};
my $elapsed = now() - $t0;
my $fd = fileno($self->{sock});
out($self, " deferred[$fd] done - %0.6f", $elapsed);
my $wbuf = $self->{wbuf}; # do NOT autovivify
$self->requeue unless $wbuf && @$wbuf;
}
}
sub err ($$;@) {
my ($self, $fmt, @args) = @_;
printf { $self->{imapd}->{err} } $fmt."\n", @args;
}
sub out ($$;@) {
my ($self, $fmt, @args) = @_;
printf { $self->{imapd}->{out} } $fmt."\n", @args;
}
sub long_response ($$;@) {
my ($self, $cb, @args) = @_; # cb returns true if more, false if done
my $sock = $self->{sock} or return;
# make sure we disable reading during a long response,
# clients should not be sending us stuff and making us do more
# work while we are stream a response to them
$self->{long_cb} = [ fileno($sock), $cb, now(), @args ];
long_step($self); # kick off!
undef;
}
# callback used by PublicInbox::DS for any (e)poll (in/out/hup/err)
sub event_step {
my ($self) = @_;
return unless $self->flush_write && $self->{sock} && !$self->{long_cb};
# only read more requests if we've drained the write buffer,
# otherwise we can be buffering infinitely w/o backpressure
my $rbuf = $self->{rbuf} // \(my $x = '');
my $line = index($$rbuf, "\n");
while ($line < 0) {
if (length($$rbuf) >= LINE_MAX) {
$self->write(\"\* BAD request too long\r\n");
return $self->close;
}
$self->do_read($rbuf, LINE_MAX, length($$rbuf)) or
return uo2m_hibernate($self);
$line = index($$rbuf, "\n");
}
$line = substr($$rbuf, 0, $line + 1, '');
$line =~ s/\r?\n\z//s;
return $self->close if $line =~ /[[:cntrl:]]/s;
my $t0 = now();
my $fd = fileno($self->{sock});
my $r = eval { process_line($self, $line) };
my $pending = $self->{wbuf} ? ' pending' : '';
out($self, "[$fd] %s - %0.6f$pending - $r", $line, now() - $t0);
return $self->close if $r < 0;
$self->rbuf_idle($rbuf);
# maybe there's more pipelined data, or we'll have
# to register it for socket-readiness notifications
$self->requeue unless $pending;
}
sub compressed { undef }
sub zflush {} # overridden by IMAPdeflate
# RFC 4978
sub cmd_compress ($$$) {
my ($self, $tag, $alg) = @_;
return "$tag BAD DEFLATE only\r\n" if uc($alg) ne "DEFLATE";
return "$tag BAD COMPRESS active\r\n" if $self->compressed;
# CRIME made TLS compression obsolete
# return "$tag NO [COMPRESSIONACTIVE]\r\n" if $self->tls_compressed;
PublicInbox::IMAPdeflate->enable($self, $tag);
$self->requeue;
undef
}
sub cmd_starttls ($$) {
my ($self, $tag) = @_;
my $sock = $self->{sock} or return;
if ($sock->can('stop_SSL') || $self->compressed) {
return "$tag BAD TLS or compression already enabled\r\n";
}
my $opt = $self->{imapd}->{accept_tls} or
return "$tag BAD can not initiate TLS negotiation\r\n";
$self->write(\"$tag OK begin TLS negotiation now\r\n");
$self->{sock} = IO::Socket::SSL->start_SSL($sock, %$opt);
$self->requeue if PublicInbox::DS::accept_tls_step($self);
undef;
}
sub busy { # for graceful shutdown in PublicInbox::Daemon:
my ($self) = @_;
if (defined($self->{-idle_tag})) {
$self->write(\"* BYE server shutting down\r\n");
return; # not busy anymore
}
defined($self->{rbuf}) || defined($self->{wbuf}) ||
!$self->write(\"* BYE server shutting down\r\n");
}
sub close {
my ($self) = @_;
if (my $ibx = delete $self->{ibx}) {
stop_idle($self, $ibx);
}
$self->SUPER::close; # PublicInbox::DS::close
}
# we're read-only, so SELECT and EXAMINE do the same thing
no warnings 'once';
*cmd_select = \&cmd_examine;
package PublicInbox::IMAP_preauth;
our @ISA = qw(PublicInbox::IMAP);
sub logged_in { 0 }
1;