sendmail/filter.pl

   1 #!/usr/local/bin/perl
   2 # filter.pl
   3
   4 # read sendmail module config
   5 $p = -l $0 ? readlink($0) : $0;
   6 $p =~ /^(.*)\/[^\/]+$/;
   7 if (open(CONF, "$1/config")) {
   8         while(<CONF>) {
   9                 if (/^(\S+)=(.*)/) {
  10                         $config{$1} = $2;
  11                         }
  12                 }
  13         close(CONF);
  14         }
  15 if (!$config{'sendmail_path'}) {
  16         # Make some guesses about sendmail
  17         if (-x "/usr/sbin/sendmail") {
  18                 %config = ( 'sendmail_path' => '/usr/sbin/sendmail' );
  19                 }
  20         elsif (-x "/usr/lib/sendmail") {
  21                 %config = ( 'sendmail_path' => '/usr/lib/sendmail' );
  22                 }
  23         else {
  24                 die "Failed to find sendmail or config file";
  25                 }
  26         }
  27 # read headers and body
  28 $fromline = <STDIN>;
  29 while(<STDIN>) {
  30         $headers .= $_;
  31         s/\r|\n//g;
  32         if (/^(\S+):\s+(.*)/) {
  33                 $header{lc($1)} = $2;
  34                 }
  35         elsif (!$_) { last; }
  36         }
  37 while(<STDIN>) {
  38         if ($_ eq ".\n") {
  39                 # Single line with a . confuses SMTP
  40                 $body .= ". \n";
  41                 }
  42         elsif ($_ eq ".\r\n") {
  43                 $body .= ". \r\n";
  44                 }
  45         else {
  46                 $body .= $_;
  47                 }
  48         }
  49
  50 # read the filter file
  51 if (open(FILTER, $ARGV[0])) {
  52         while(<FILTER>) {
  53                 s/\r|\n//g;
  54                 if (/^(\S+)\s+(\S+)\s+(\S+)\s+(.*)$/) {
  55                         push(@filter, [ $1, $2, $3, $4 ]);
  56                         }
  57                 elsif (/^(\S+)\s+(\S+)$/) {
  58                         push(@filter, [ $1, $2 ]);
  59                         }
  60                 }
  61         close(FILTER);
  62         }
  63 else {
  64         print STDERR "Filter file $ARGV[0] does not exist!\n";
  65         exit 1;
  66         }
  67
  68 # run the filter to find the first matching rule
  69 open(LOG, ">>$ARGV[0].log");
  70 foreach $f (@filter) {
  71         local $field = $f->[2] eq 'body' ? $body : $header{$f->[2]};
  72         local $st = 0;
  73         if ($f->[0] == 0) {
  74                 $st = ($field !~ /$f->[3]/i);
  75                 }
  76         elsif ($f->[0] == 1) {
  77                 $st = ($field =~ /$f->[3]/i);
  78                 }
  79         elsif ($f->[0] == 2) {
  80                 $st = 1;
  81                 }
  82         if ($st) {
  83                 # The rule matched!
  84                 if ($f->[1] =~ /^\//) {
  85                         # Write to a file
  86                         open(MAIL, ">>$f->[1]") || die "Failed to open $f->[1] ; $!";
  87                         print MAIL $fromline;
  88                         }
  89                 else {
  90                         # Forward to another address
  91                         open(MAIL, "|$config{'sendmail_path'} ".
  92                                    quotemeta($f->[1]));
  93                         }
  94                 print MAIL $headers;
  95                 print MAIL $body;
  96                 close(MAIL);
  97                 $now = localtime(time());
  98                 print LOG "[$now] [$header{'from'}] [",join(" ",@$f),"]\n";
  99                 last;
 100                 }
 101         }
 102