# Copyright (C) 2021 all contributors
# License: AGPL-3.0+
# common reader code for IMAP and NNTP (and maybe JMAP)
package PublicInbox::NetReader;
use strict;
use v5.10.1;
use parent qw(Exporter PublicInbox::IPC);
use PublicInbox::Eml;
# TODO: trim this down, this is huge
our @EXPORT = qw(uri_new uri_scheme uri_section
mic_for nn_new nn_for
imap_url nntp_url
cfg_bool cfg_intvl imap_common_init
);
# avoid exposing deprecated "snews" to users.
my %SCHEME_MAP = ('snews' => 'nntps');
sub uri_scheme ($) {
my ($uri) = @_;
my $scheme = $uri->scheme;
$SCHEME_MAP{$scheme} // $scheme;
}
# returns the git config section name, e.g [imap "imaps://user@example.com"]
# without the mailbox, so we can share connections between different inboxes
sub uri_section ($) {
my ($uri) = @_;
uri_scheme($uri) . '://' . $uri->authority;
}
sub auth_anon_cb { '' }; # for Mail::IMAPClient::Authcallback
sub mic_for { # mic = Mail::IMAPClient
my ($self, $url, $mic_args, $lei) = @_;
require PublicInbox::URIimap;
my $uri = PublicInbox::URIimap->new($url);
require PublicInbox::GitCredential;
my $cred = bless {
url => $url,
protocol => $uri->scheme,
host => $uri->host,
username => $uri->user,
password => $uri->password,
}, 'PublicInbox::GitCredential';
my $common = $mic_args->{uri_section($uri)} // {};
# IMAPClient and Net::Netrc both mishandles `0', so we pass `127.0.0.1'
my $host = $cred->{host};
$host = '127.0.0.1' if $host eq '0';
my $mic_arg = {
Port => $uri->port,
Server => $host,
Ssl => $uri->scheme eq 'imaps',
Keepalive => 1, # SO_KEEPALIVE
%$common, # may set Starttls, Compress, Debug ....
};
require PublicInbox::IMAPClient;
my $mic = PublicInbox::IMAPClient->new(%$mic_arg) or
die "E: <$url> new: $@\n";
# default to using STARTTLS if it's available, but allow
# it to be disabled since I usually connect to localhost
if (!$mic_arg->{Ssl} && !defined($mic_arg->{Starttls}) &&
$mic->has_capability('STARTTLS') &&
$mic->can('starttls')) {
$mic->starttls or die "E: <$url> STARTTLS: $@\n";
}
# do we even need credentials?
if (!defined($cred->{username}) &&
$mic->has_capability('AUTH=ANONYMOUS')) {
$cred = undef;
}
if ($cred) {
$cred->check_netrc unless defined $cred->{password};
$cred->fill($lei); # may prompt user here
$mic->User($mic_arg->{User} = $cred->{username});
$mic->Password($mic_arg->{Password} = $cred->{password});
} else { # AUTH=ANONYMOUS
$mic->Authmechanism($mic_arg->{Authmechanism} = 'ANONYMOUS');
$mic_arg->{Authcallback} = 'auth_anon_cb';
$mic->Authcallback(\&auth_anon_cb);
}
my $err;
if ($mic->login && $mic->IsAuthenticated) {
# success! keep IMAPClient->new arg in case we get disconnected
$self->{mic_arg}->{uri_section($uri)} = $mic_arg;
} else {
$err = "E: <$url> LOGIN: $@\n";
if ($cred && defined($cred->{password})) {
$err =~ s/\Q$cred->{password}\E/*******/g;
}
$mic = undef;
}
$cred->run($mic ? 'approve' : 'reject') if $cred;
if ($err) {
$lei ? $lei->fail($err) : warn($err);
}
$mic;
}
sub uri_new {
my ($url) = @_;
require URI;
# URI::snews exists, URI::nntps does not, so use URI::snews
$url =~ s!\Anntps://!snews://!i;
URI->new($url);
}
# Net::NNTP doesn't support CAPABILITIES, yet
sub try_starttls ($) {
my ($host) = @_;
return if $host =~ /\.onion\z/s;
return if $host =~ /\A127\.[0-9]+\.[0-9]+\.[0-9]+\z/s;
return if $host eq '::1';
1;
}
sub nn_new ($$$) {
my ($nn_arg, $nntp_opt, $url) = @_;
my $nn = Net::NNTP->new(%$nn_arg) or die "E: <$url> new: $!\n";
# default to using STARTTLS if it's available, but allow
# it to be disabled for localhost/VPN users
if (!$nn_arg->{SSL} && $nn->can('starttls')) {
if (!defined($nntp_opt->{starttls}) &&
try_starttls($nn_arg->{Host})) {
# soft fail by default
$nn->starttls or warn <<"";
W: <$url> STARTTLS tried and failed (not requested)
} elsif ($nntp_opt->{starttls}) {
# hard fail if explicitly configured
$nn->starttls or die <<"";
E: <$url> STARTTLS requested and failed
}
} elsif ($nntp_opt->{starttls}) {
$nn->can('starttls') or
die "E: <$url> Net::NNTP too old for STARTTLS\n";
$nn->starttls or die <<"";
E: <$url> STARTTLS requested and failed
}
$nn;
}
sub nn_for ($$$;$) { # nn = Net::NNTP
my ($self, $url, $nn_args, $lei) = @_;
my $uri = uri_new($url);
my $sec = uri_section($uri);
my $nntp_opt = $self->{nntp_opt}->{$sec} //= {};
my $host = $uri->host;
# Net::NNTP and Net::Netrc both mishandle `0', so we pass `127.0.0.1'
$host = '127.0.0.1' if $host eq '0';
my $cred;
my ($u, $p);
if (defined(my $ui = $uri->userinfo)) {
require PublicInbox::GitCredential;
$cred = bless {
url => $sec,
protocol => uri_scheme($uri),
host => $host,
}, 'PublicInbox::GitCredential';
($u, $p) = split(/:/, $ui, 2);
($cred->{username}, $cred->{password}) = ($u, $p);
$cred->check_netrc unless defined $p;
}
my $common = $nn_args->{$sec} // {};
my $nn_arg = {
Port => $uri->port,
Host => $host,
SSL => $uri->secure, # snews == nntps
%$common, # may Debug ....
};
my $nn = nn_new($nn_arg, $nntp_opt, $url);
if ($cred) {
$cred->fill($lei); # may prompt user here
if ($nn->authinfo($u, $p)) {
push @{$nntp_opt->{-postconn}}, [ 'authinfo', $u, $p ];
} else {
warn "E: <$url> AUTHINFO $u XXXX failed\n";
$nn = undef;
}
}
if ($nntp_opt->{compress}) {
# https://rt.cpan.org/Ticket/Display.html?id=129967
if ($nn->can('compress')) {
if ($nn->compress) {
push @{$nntp_opt->{-postconn}}, [ 'compress' ];
} else {
warn "W: <$url> COMPRESS failed\n";
}
} else {
delete $nntp_opt->{compress};
warn <<"";
W: <$url> COMPRESS not supported by Net::NNTP
W: see https://rt.cpan.org/Ticket/Display.html?id=129967 for updates
}
}
$self->{nn_arg}->{$sec} = $nn_arg;
$cred->run($nn ? 'approve' : 'reject') if $cred;
$nn;
}
sub imap_url {
my ($url) = @_;
require PublicInbox::URIimap;
my $uri = PublicInbox::URIimap->new($url);
$uri ? $uri->canonical->as_string : undef;
}
my %IS_NNTP = (news => 1, snews => 1, nntp => 1);
sub nntp_url {
my ($url) = @_;
my $uri = uri_new($url);
return unless $uri && $IS_NNTP{$uri->scheme} && $uri->group;
$url = $uri->canonical->as_string;
# nntps is IANA registered, snews is deprecated
$url =~ s!\Asnews://!nntps://!;
$url;
}
sub cfg_intvl ($$$) {
my ($cfg, $key, $url) = @_;
my $v = $cfg->urlmatch($key, $url) // return;
$v =~ /\A[0-9]+(?:\.[0-9]+)?\z/s and return $v + 0;
if (ref($v) eq 'ARRAY') {
$v = join(', ', @$v);
warn "W: $key has multiple values: $v\nW: $key ignored\n";
} else {
warn "W: $key=$v is not a numeric value in seconds\n";
}
}
sub cfg_bool ($$$) {
my ($cfg, $key, $url) = @_;
my $orig = $cfg->urlmatch($key, $url) // return;
my $bool = $cfg->git_bool($orig);
warn "W: $key=$orig for $url is not boolean\n" unless defined($bool);
$bool;
}
# flesh out common IMAP-specific data structures
sub imap_common_init ($;$) {
my ($self, $lei) = @_;
$self->{quiet} = 1 if $lei && $lei->{opt}->{quiet};
eval { require PublicInbox::IMAPClient } or
die "Mail::IMAPClient is required for IMAP:\n$@\n";
eval { require PublicInbox::IMAPTracker } or
die "DBD::SQLite is required for IMAP\n:$@\n";
require PublicInbox::URIimap;
my $cfg = $self->{pi_cfg} // $lei->_lei_cfg;
my $mic_args = {}; # scheme://authority => Mail:IMAPClient arg
for my $url (@{$self->{imap_order}}) {
my $uri = PublicInbox::URIimap->new($url);
my $sec = uri_section($uri);
for my $k (qw(Starttls Debug Compress)) {
my $bool = cfg_bool($cfg, "imap.$k", $url) // next;
$mic_args->{$sec}->{$k} = $bool;
}
my $to = cfg_intvl($cfg, 'imap.timeout', $url);
$mic_args->{$sec}->{Timeout} = $to if $to;
for my $k (qw(pollInterval idleInterval)) {
$to = cfg_intvl($cfg, "imap.$k", $url) // next;
$self->{imap_opt}->{$sec}->{$k} = $to;
}
my $k = 'imap.fetchBatchSize';
my $bs = $cfg->urlmatch($k, $url) // next;
if ($bs =~ /\A([0-9]+)\z/) {
$self->{imap_opt}->{$sec}->{batch_size} = $bs;
} else {
warn "$k=$bs is not an integer\n";
}
}
# make sure we can connect and cache the credentials in memory
$self->{mic_arg} = {}; # schema://authority => IMAPClient->new args
my $mics = {}; # schema://authority => IMAPClient obj
for my $url (@{$self->{imap_order}}) {
my $uri = PublicInbox::URIimap->new($url);
my $sec = uri_section($uri);
$mics->{$sec} //= mic_for($self, $url, $mic_args, $lei);
}
$mics;
}
sub add_url {
my ($self, $arg) = @_;
if (my $url = imap_url($arg)) {
push @{$self->{imap_order}}, $url;
} else {
push @{$self->{unsupported_url}}, $arg;
}
}
sub errors {
my ($self) = @_;
if (my $u = $self->{unsupported_url}) {
return "Unsupported URL(s): @$u";
}
if ($self->{imap_order}) {
eval { require PublicInbox::IMAPClient } or
die "Mail::IMAPClient is required for IMAP:\n$@\n";
}
undef;
}
my %IMAPflags2kw = (
'\Seen' => 'seen',
'\Answered' => 'answered',
'\Flagged' => 'flagged',
'\Draft' => 'draft',
);
sub _imap_do_msg ($$$$$) {
my ($self, $url, $uid, $raw, $flags) = @_;
# our target audience expects LF-only, save storage
$$raw =~ s/\r\n/\n/sg;
my $kw = [];
for my $f (split(/ /, $flags)) {
my $k = $IMAPflags2kw{$f} // next; # TODO: X-Label?
push @$kw, $k;
}
my ($eml_cb, @args) = @{$self->{eml_each}};
$eml_cb->($url, $uid, $kw, PublicInbox::Eml->new($raw), @args);
}
sub _imap_fetch_all ($$$) {
my ($self, $mic, $url) = @_;
my $uri = PublicInbox::URIimap->new($url);
my $sec = uri_section($uri);
my $mbx = $uri->mailbox;
$mic->Clear(1); # trim results history
$mic->examine($mbx) or return "E: EXAMINE $mbx ($sec) failed: $!";
my ($r_uidval, $r_uidnext);
for ($mic->Results) {
/^\* OK \[UIDVALIDITY ([0-9]+)\].*/ and $r_uidval = $1;
/^\* OK \[UIDNEXT ([0-9]+)\].*/ and $r_uidnext = $1;
last if $r_uidval && $r_uidnext;
}
$r_uidval //= $mic->uidvalidity($mbx) //
return "E: $url cannot get UIDVALIDITY";
$r_uidnext //= $mic->uidnext($mbx) //
return "E: $url cannot get UIDNEXT";
my $itrk = $self->{incremental} ?
PublicInbox::IMAPTracker->new($url) : 0;
my ($l_uidval, $l_uid) = $itrk ? $itrk->get_last : ();
$l_uidval //= $r_uidval; # first time
$l_uid //= 1;
if ($l_uidval != $r_uidval) {
return "E: $url UIDVALIDITY mismatch\n".
"E: local=$l_uidval != remote=$r_uidval";
}
my $r_uid = $r_uidnext - 1;
if ($l_uid != 1 && $l_uid > $r_uid) {
return "E: $url local UID exceeds remote ($l_uid > $r_uid)\n".
"E: $url strangely, UIDVALIDLITY matches ($l_uidval)\n";
}
return if $l_uid >= $r_uid; # nothing to do
warn "# $url fetching UID $l_uid:$r_uid\n" unless $self->{quiet};
$mic->Uid(1); # the default, we hope
my $bs = $self->{imap_opt}->{$sec}->{batch_size} // 1;
my $req = $mic->imap4rev1 ? 'BODY.PEEK[]' : 'RFC822.PEEK';
my $key = $req;
$key =~ s/\.PEEK//;
my ($uids, $batch);
my $err;
do {
# I wish "UID FETCH $START:*" could work, but:
# 1) servers do not need to return results in any order
# 2) Mail::IMAPClient doesn't offer a streaming API
$uids = $mic->search("UID $l_uid:*") or
return "E: $url UID SEARCH $l_uid:* error: $!";
return if scalar(@$uids) == 0;
# RFC 3501 doesn't seem to indicate order of UID SEARCH
# responses, so sort it ourselves. Order matters so
# IMAPTracker can store the newest UID.
@$uids = sort { $a <=> $b } @$uids;
# Did we actually get new messages?
return if $uids->[0] < $l_uid;
$l_uid = $uids->[-1] + 1; # for next search
my $last_uid;
my $n = $self->{max_batch};
while (scalar @$uids) {
my @batch = splice(@$uids, 0, $bs);
$batch = join(',', @batch);
local $0 = "UID:$batch $mbx $sec";
my $r = $mic->fetch_hash($batch, $req, 'FLAGS');
unless ($r) { # network error?
$err = "E: $url UID FETCH $batch error: $!";
last;
}
for my $uid (@batch) {
# messages get deleted, so holes appear
my $per_uid = delete $r->{$uid} // next;
my $raw = delete($per_uid->{$key}) // next;
_imap_do_msg($self, $url, $uid, \$raw,
$per_uid->{FLAGS});
$last_uid = $uid;
last if $self->{quit};
}
last if $self->{quit};
}
$itrk->update_last($r_uidval, $last_uid) if $itrk;
} until ($err || $self->{quit});
$err;
}
sub imap_each {
my ($self, $url, $eml_cb, @args) = @_;
my $uri = PublicInbox::URIimap->new($url);
my $sec = uri_section($uri);
my $mic_arg = $self->{mic_arg}->{$sec} or
die "BUG: no Mail::IMAPClient->new arg for $sec";
local $0 = $uri->mailbox." $sec";
my $cb_name = $mic_arg->{Authcallback};
if (ref($cb_name) ne 'CODE') {
$mic_arg->{Authcallback} = $self->can($cb_name);
}
my $mic = PublicInbox::IMAPClient->new(%$mic_arg, Debug => 0);
my $err;
if ($mic && $mic->IsConnected) {
local $self->{eml_each} = [ $eml_cb, @args ];
$err = _imap_fetch_all($self, $mic, $url);
} else {
$err = "E: not connected: $!";
}
$mic;
}
sub new { bless {}, shift };
1;