2 # SPDX-License-Identifier: GPL-2.0-only
6 BEGIN { pop @INC if $INC[-1] eq '.' };
8 use Fcntl qw(:DEFAULT :flock :seek);
12 use constant MIN_AGE => 60; # seconds
13 my $exim = exists $ENV{'EXIM_BINARY'} ? $ENV{'EXIM_BINARY'} : 'exim';
15 my %known_okay = map {$_=>1} qw( linux darwin freebsd );
16 unless (exists $known_okay{$^O}) {
17 warn "for ease, this perl uses flock, not fcntl, assuming they're the same\n";
18 warn "this is not known by this author to be the case on $^O\n";
19 warn "please investigate and either add to allowed-list in script, or rewrite\n";
22 # Another approach to rewriting script: stop all exim receivers and
23 # queue-runners, prevent them from starting, then add your OS to the list and
24 # run, even though the locking type is wrong, relying upon not actually
28 my $spool_dir = `$exim -n -bP spool_directory`;
31 chdir(File::Spec->catfile($spool_dir, 'input'))
32 or die "chdir($spool_dir/input) failed: $!\n";
34 my $exim_msgid_r = qr/(?:[0-9A-Za-z]{6}-[0-9A-Za-z]{6}-[0-9A-Za-z]{2})/;
35 my $spool_dfile_r = qr/^(($exim_msgid_r)-D)\z/o;
38 my ($fh, $dfn, $verbose) = @_;
39 seek($fh, -1, 2) or do { warn "seek(file($dfn)) failed: $!\n"; return -1 };
40 my $count = read $fh, my $ch, 1;
41 if ($count == -1) { warn "failed to read last byte of $dfn\n"; return -1 };
42 if ($count == 0) { warn "file shrunk by one?? problem with $dfn\n"; return -1 };
43 if ($ch eq "\n") { print "okay!\n" if $verbose; return 1 }
44 print "PROBLEM: $dfn missing final newline (got $ch)\n" if $verbose;
50 return unless $_ =~ $spool_dfile_r;
51 my ($msgid, $dfn) = ($2, $1);
53 # We should have already upgraded Exim before invoking us, thus any spool
54 # files will be old and we can reduce spending time trying to lock files
55 # still being written to, etc.
56 my @st = lstat($dfn) or return;
57 if ($^T - $st[9] < MIN_AGE) { return };
58 -f "./${msgid}-H" || return;
60 print "consider: $dfn\n";
61 open(my $fh, '+<:raw', $dfn) or do {
62 warn "open($dfn) failed: $!\n";
65 # return with a lexical FH in modern Perl should guarantee close, AIUI
67 # we do our first check without a lock, so that we can scan past messages
68 # being handled by Exim quickly, and only lock up on those which Exim is
69 # trying and failing to deliver. However, since Exim will be hung on remote
70 # hosts, this is likely. Thus best to kill queue-runners first.
72 return if fh_ends_newline($fh, $dfn, 0); # also returns on error
73 print "Problem? $msgid probably missing newline, locking to be sure ...\n";
74 flock($fh, LOCK_EX) or do { warn "flock(file($dfn)) failed: $!\n"; return };
75 return if fh_ends_newline($fh, $dfn, 1); # also returns on error
77 fixup_message($msgid, $dfn, $fh);
79 close($fh) or warn "close($dfn) failed: $!\n";
83 my ($msgid, $dfn, $fh) = @_;
84 # we can't freeze the message, our lock stops that, which is good!
86 seek($fh, 0, 2) or do { warn "seek(file($dfn)) failed: $!\n"; return -1 };
88 my $r = inc_message_header_linecount($msgid);
90 warn "failed to fix message headers in ${msgid}-H so not editing message\n";
96 print "${msgid}: added newline\n";
99 sub inc_message_header_linecount {
101 my $name_in = "${msgid}-H";
102 my $name_out = "${msgid}-chunkfix";
104 open(my $in, '<:perlio', $name_in) or do { warn "open(${name_in}) failed: $!\n"; return -1 };
105 open(my $out, '>:perlio', $name_out) or do { warn "write-open(${name_out}) failed: $!\n"; return -1 };
113 if (/^(-body_linecount\s+)(\d+)(\s*)$/) {
115 print {$out} "${1}${lc}${3}";
122 warn "read-close(${msgid}-H) failed, assuming incomplete: $!\n";
128 warn "write-close(${msgid}-chunkfix) failed, aborting: $!\n";
133 my @target = stat($name_in) or do { warn "stat($name_in) failed: $!\n"; unlink $name_out; return -1 };
134 my @created = stat($name_out) or do { warn "stat($name_out) failed: $!\n"; unlink $name_out; return -1 };
135 # 4=uid, 5=gid, 2=mode
136 if (($created[5] != $target[5]) or ($created[4] != $target[4])) {
137 chown $target[4], $target[5], $name_out or do {
138 warn "chown($name_out) failed: $!\n";
143 if (($created[2]&07777) != ($target[2]&0x7777)) {
144 chmod $target[2]&0x7777, $name_out or do {
145 warn "chmod($name_out) failed: $!\n";
151 rename $name_out, $name_in or do {
152 warn "rename '${msgid}-chunkfix' -> '${msgid}-H' failed: $!\n";
157 print "${msgid}: linecount set to $lc\n";
161 find({wanted => \&each_found_file}, '.');