/usr/share/doc/bogofilter-common/examples/contrib/bogofilter-milter.pl is in bogofilter-common 1.2.4+dfsg1-4build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 | #!/usr/bin/perl
# $Id: bogofilter-milter.pl 6902 2010-04-08 04:07:24Z relson $
#
# bogofilter-milter.pl - a Sendmail::Milter Perl script for filtering
# mail using individual users' bogofilter databases.
#
# (additional information below the coypright statement)
# Copyright 2003, 2005, 2007, 2008, 2010 Jonathan Kamens
# <jik@kamens.brookline.ma.us>. Please send me bug reports,
# suggestions, criticisms, compliments, or any other feedback you have
# about this script!
#
# The current version of this script and extensive additional
# documentation are available from
# <http://stuff.mit.edu/~jik/software/bogofilter/>.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
# You will need the following non-standard Perl modules installed to
# use this script: Sendmail::Milter, Mail::Alias, Proc::Daemon,
# IO::Stringy, Socket, Net::CIDR. Before using this script, search
# for CONFIGURABLE SETTINGS and configure them appropriately for your
# site.
#
# Inserts "X-Bogosity: Spam, tests=bogofilter" into messages that
# appear to be spam (or "Ham" or "Unsure" into ones that don't). If
# the message is rejected, you usually won't see the "Spam", but see
# below about training mode.
#
# Save this script somewhere, launch it as root (by running it in the
# background or invoking it with "--daemon" in which case it will
# background itself), and reconfigure your sendmail installation to
# call it as an external filter (probably by calling INPUT_MAIL_FILTER
# in your sendmail.mc file). Running this script as root should be
# safe because it changes its effective UID and GID whenever
# performing operations on individual users' files (if you find a
# security problem, please let me know!).
#
# NOTE: You will want to take steps to ensure that this script is
# started before sendmail whenever your machine boots, e.g., by
# creating an appropriate script in /etc/rc.d/init.d with appropriate
# links to it in /etc/rc.d/rc?.d, because once you configure sendmail
# to talk to a particular milter, it may refuse to deliver email if
# that milter isn't running when the email comes in.
#
# For additional information about libmilter and integrating this or
# any other libmilter filter into your sendmail installation, see the
# file README.libmilter that ships with sendmail and/or the section
# entitled "ADDING NEW MAIL FILTERS" in the README file that ships
# with the M4 sendmail CF templates.
#
# You may need to restart this script to get it to notice changes in
# mail aliases.
# This script logs various informational, warning and error messages
# to the "mail" facility.
# Thanks to Tom Anderson <neo+bogofilter-milter@orderamidchaos.com>
# for the IP whitelisting changes and for several other useful
# suggestions and bug fixes.
# BEGIN CONFIGURABLE SETTINGS
# If this string appears in the Subject of a message (case
# insensitive), the message won't be filtered.
my $magic_string = '[no-bogofilter]';
# Set the syslog facility you wish to log messages to.
my $log_facility = 'LOG_MAIL';
# These settings control exactly what error sendmail sends back to the
# sender if a message is rejected. You can leave them as-is, or
# customize them as desired.
my $rcode = 550; # three-digit RFC 821 SMTP reply
my $xcode = "5.7.1"; # extended RFC 2034 reply code
my $reject_message = "Your message looks like spam.\n" .
"If it isn't, resend it with $magic_string " .
"in the Subject line.";
# Whitelist any IP addresses or ranges from this filter.
# For example:
#my(@whitelist) = ("127.0.0.1", "10.127.0.1-10.127.0.9", "192.168.0.0/16");
my(@ip_whitelist) = ();
# If you want to whitelist any addresses which have authenticated
# via poprelayd (i.e. remote workstations of users on your server)
# set $dbfile to your popip.db location, else set it to undef.
# For example:
#my $ip_whitelist_db = "/etc/mail/popip.db";
my $ip_whitelist_db = undef;
# The largest message to keep in memory rather than writing to a
# temporary file.
my $MAX_INCORE_MSG_LENGTH = 1000000;
my $pid_file = '/var/run/bogofilter-milter.pid';
# Whatever path you specify for $socket needs to match the socket
# specified in the sendmail.cf file (with "local:" in front of it
# there, but not here).
my $socket = '/var/run/bogofilter-milter.sock';
# The following two settings give more granular control over whether
# bogofilter is used for any particular user and what configuration
# settings are used when it is.
# - If $bogofilter_cf is set, then the script will look for a file
# with that name in the user's home directory. If it finds it, then
# bogofilter will be called with "-c $HOME/$bogofilter_cf" so that the
# specified configuration file is used rather than the default,
# .bogofilter.cf.
# - If $require_cf is true, then the specified configuration file
# *must* exist for bogofilter to be used for this user. In other
# words, rather than only looking for the .bogofilter subdirectory of
# the user's home directory, the script will look for both the
# .bogofilter subdirectory *and* the config file.
# - Note that $require_cf is ignored if $bogofilter_cf is unset.
my $bogofilter_cf = undef;
my $require_cf = undef;
# If you would like the milter to add a unique ID to the X-Bogosity
# line, then set this variable to true. ", milter_id=..." will be
# added to the end of the X-Bogosity line.
my $add_unique_id = 1;
# If a file with this name exists in the user's .bogofilter directory,
# then it is assumed to contain regular expressions, one per line, to
# match against Subject lines in incoming messages (lines containing
# only whitespace and lines starting with "#" are ignored). Any
# message whose Subject line matches one of the regular expressions
# will not be filtered, just as if $magic_string (see above) had
# appeared in its Subject line.
my $subject_filter_file = 'milter-subject-filters';
# If an executable file or link with this name exists in the user's
# .bogofilter directory, and it is owned by the user or root (for
# security reasons), then it will be used as a filter, i.e., the
# message will be fed into it and replaced with its output, before
# bogofilter is run on it, if it returns a zero exit status.
# Furthermore, the filtered message is what will be put into the
# $archive_mbox and $ham_archive_mbox files. However, the actual
# message delivered by the MTA if the milter accepts it will be the
# unfiltered version, not the filtered version. You could use this,
# e.g., to reformat incoming email with a script that calls
# spamitariuim.pl (in bogofilter contrib directory) before filtering
# it.
#
# The following environment variables are available to the script when
# it is executed:
#
# MILTER_REMOTE_IP IP address of remote SMTP server
# MILTER_REMOTE_NAME Host name of remote SMTP server as per a
# reverse DNS lookup on its IP address
# MILTER_LOCAL_IP IP address of SMTP server receiving the
# message
# MILTER_LOCAL_NAME Host name of SMTP server receiving the message
# MILTER_HELOHOST Host name specified by the remote server in
# its HELO or EHLO command
# MILTER_ENVFROM The envelope address of the sender of the
# message, a.k.a., the Return-Path
# MILTER_ENVRCPT The envelope address of the recipient of the
# message for whom bogofilter is being invoked.
#
# If you want to disable this functionality, set the variable to
# undef.
my $filter_script = 'milter-filter-script';
# If a file with this name exists in the user's .bogofilter directory,
# then that user's mail will be filtered in training mode. This means
# that the message will be filtered and registered as spam or non-spam
# and the appropriate X-Bogosity header will be inserted, but it'll be
# delivered even if bogofilter thinks it's spam. This allows the user
# to detect false positives or false negatives and feed them back into
# bogofilter to train it. To disable this functionality set
# $training_file to undef.
my $training_file = 'training';
# If a file or link with this name exists in the user's .bogofilter
# directory, then copies of rejected messages will be saved in this
# file in mbox format, using flock locking. To disable rejected
# message archiving, set $archive_mbox to undef.
my $archive_mbox = 'archive';
# If a file or link with this name exists in the user's .bogofilter
# directory, then copies of accepted messages (Ham or Unsure) will be
# saved in this file in mbox format, using flock locking. To disable
# accepted message archiving, set $ham_archive_mbox to undef.
my $ham_archive_mbox = 'ham_archive';
# If $cyrus_deliver is set to an existing executable, then it is
# assumed to be a Cyrus IMAP "deliver" program. If the $archive_mbox
# or $ham_archive_mbox for a particular user is a symlink pointing at
# a nonexistent file whose name starts with "cyrus:", then everything
# after the "cyrus:" is assumed to be the name of a Cyrus IMAP folder
# within the user's mailbox to which to deliver the spam message
# instead of saving it into an mbox format file.
my $cyrus_deliver = '/usr/lib/cyrus-imapd/deliver';
# If you would like to use a shared bogofilter database for everyone,
# rather than separate per-user databases, then create a user on your
# system to be used as a home for the shared database, and set
# $database_user to that user's username.
#
# If you set $database_user, then all the logic described above for
# deciding whether to run bogofilter, whether to run in training mode
# or real mode, and whether to archive spam still applies, so make
# sure you configure $database_user's account properly.
#
# If you set $database_user, then $aliases_file, $sendmail_canon,
# $sendmail_prog, $recipient_cache_expire, and
# $recipient_cache_check_interval do NOT apply and are ignored.
my $database_user = undef;
# Mail::Alias is used to expand SMTP recipient addresses into local
# mailboxes to determine if any of them have bogofilter databases. If
# someone sends E-mail to a mailing list or alias whose expansion
# contains one or more local users with bogofilter databases, then one
# of those users' database (which one in particular is not defined)
# will be used to filter the message. To disable this functionality
# and remove the dependency on Mail::Alias, comment out the "use
# Mail::Alias;" line and set $aliases_file to undef in the
# configuration section. With this functionality disabled, mail will
# only be filtered if it is sent directly to a user in the passwd
# file. On the other hand, with this functionality enabled, one
# person's bogofilter database can cause a message to be filtered for
# everyone on a local mailing list.
my $aliases_file = '/etc/aliases';
# If you want the milter to ask sendmail to canonicalize recipient
# addresses before trying to alias-expand them, then set
# $sendmail_canon to true and $sendmail_prog to the path of the
# sendmail binary to invoke. This is necessary, e.g., if you use a
# virtual user table for some recipients that do sendmail filtering.
# You may also wish to examine the sendmail_canon subroutine below,
# because it may not be right for your particular sendmail
# configuration. Search for CHECKTHIS in the function.
my $sendmail_canon = 1;
my $sendmail_prog = '/usr/sbin/sendmail';
# @discard_control is an array of anonymous arrays. Each sub-array
# contains a pair of entries, a control pattern and an action, either
# "discard" or "reject". The action corresponding to the first
# matching control pattern determines what happens to the messages.
# If @discard_control is empty or none of its control patterns match,
# the default action is "reject". The following control patterns are
# valid:
# "addr:a.b.c.d" matches if the sending host has the indicated IP address
# "netblock:a.b.c.d/e" matches if the sending host is in the indicated netblock
# "host:fqdn" matches if the IP address of the sending host resolves
# to the indicated host name
# "domain:fqdn" matches if the IP address of the sending host resolves
# to a host name in the indicated domain
# "mx" matches if one of the MX servers for the recipient's
# domain resolves to the IP address of the sending host
# "*" always matches
# The default @discard_control setting discards messages from MX
# servers to prevent this script from contributing to spam "blowback",
# which occurs when a spammer forges someone's real email address as
# the return address on spam, and then that person has to deal with
# tons of bounce messages from sites that reject the spam.
my(@discard_control) =
(
["mx" => "discard"],
["*" => "reject"],
);
# You can configure how long addresses will stay in the cache of
# addresses that have been been expanded against the virtual user
# table (if $sendmail_canon is set above), then expanded against the
# aliases file (if $aliases_file is set above), then checked to see if
# they represent users who are doing filtering. You would want cache
# entries to time out if you get a lot of spam dictionary attacks
# against your mail server, when the spammers try tons of invalid
# addresses on the off chance that one of them might be valid, because
# in that case your cache will grow without bound and the bogofilter
# milter process will get really large. Set this to 0 to disable
# cache expiration, or to the number of seconds after which cache
# entries should expire.
#
# Configuration changes in the user's bogofilter directory, e.g.,
# changes to $subject_filter_file, aren't detected until the cache
# entry for the user expires, so if you're allowing users to make
# changes like that, you should probably reduce this timeout to
# something smaller so that their changes will take affect somewhat
# promptly.
my $recipient_cache_expire = 24 * 60 * 60; # one day
# How often to expire entries from the cache.
my $recipient_cache_check_interval = 60 * 60; # one hour
# You may wish to remove this restriction, by setting this variable to
# 0, if your site gets a lot of mail, but I haven't tested the script
# to make sure it functions correctly with multiple interpreters.
my $milter_interpreters = 1;
# END CONFIGURABLE SETTINGS
require 5.008_000; # for User::pwent
use strict;
use warnings;
use DB_File;
use Data::Dumper;
use English '-no_match_vars';
use Fcntl qw(:flock :seek);
use File::Basename;
use File::Temp qw(tempfile);
use Getopt::Long;
use IO::Scalar;
use IPC::Open2;
use Mail::Alias;
use Net::CIDR;
use Net::DNS;
use POSIX;
use Proc::Daemon;
use Sendmail::Milter;
use Socket;
use Sys::Syslog qw(:DEFAULT :macros setlogsock);
use User::pwent;
$Data::Dumper::Indent = 0;
# Used to cache the results of alias expansions and checks for
# filtered recipients.
my %cached_recipients;
my $whoami = basename $0;
my $usage = "Usage: $whoami [--daemon] [--debug] [--restart]\n";
my($run_as_daemon, $get_help, $debug, $restart);
my %my_milter_callbacks =
(
'helo' => \&my_helo_callback,
'envfrom' => \&my_envfrom_callback,
'envrcpt' => \&my_rcpt_callback,
'header' => \&my_header_callback,
'eoh' => \&my_eoh_callback,
'body' => \&my_body_callback,
'eom' => \&my_eom_callback,
'abort' => \&my_abort_callback,
'close' => \&my_close_callback,
);
$my_milter_callbacks{'connect'} = \&my_connect_callback
if (@ip_whitelist || $ip_whitelist_db || @discard_control);
die $usage if (! GetOptions('daemon' => \$run_as_daemon,
'debug' => \$debug,
'restart' => \$restart,
'help|h|?' => \$get_help));
if ($get_help) {
print $usage;
exit;
}
if ($run_as_daemon) {
Proc::Daemon::Init;
}
if (! (open(PIDFILE, '+<', $pid_file) ||
open(PIDFILE, '+>', $pid_file))) {
&die("open($pid_file): $!\n");
}
seek(PIDFILE, 0, SEEK_SET);
if (! flock(PIDFILE, LOCK_EX|LOCK_NB)) {
&die("flock($pid_file): $!\n");
}
if (! (print(PIDFILE "$$\n"))) {
&die("writing to $pid_file: $!\n");
}
# Flush the PID
seek(PIDFILE, 0, SEEK_SET);
setlogsock('unix');
openlog($whoami, 'pid', $log_facility);
if (! $debug) {
# I'd really like to to this, but it doesn't work with Sys::Syslog
# 0.13 in Perl 5.8.8.
# setlogmask(&LOG_UPTO(LOG_INFO));
eval "
no warnings 'redefine';
sub debuglog {
}
";
}
while ($restart) {
my $pid = fork();
if (! defined($pid)) {
&die("fork: $!");
}
elsif ($pid) {
$SIG{'TERM'} = sub {
&syslog('info', "got SIGTERM, shutting down");
kill 'TERM', $pid;
exit;
};
waitpid $pid, 0;
my $status = $? >> 8;
&syslog('warning', "child process $pid exited (status word $?, exit status $status)");
}
else {
last;
}
}
my $magic_string_re = $magic_string;
$magic_string_re =~ s/(\W)/\\$1/g;
# convert whitelist into CIDR notation
{
my(@whitelist_cidr);
foreach my $IP (@ip_whitelist) {
if (not eval {@whitelist_cidr =
Net::CIDR::cidradd($IP, @whitelist_cidr)}) {
&die("Error processing whitelist: \"$IP\" is not a valid IP ",
"address or range.");
}
}
@ip_whitelist = @whitelist_cidr;
}
# open popip database for reading
my %ip_whitelist_db;
&opendb_read if ($ip_whitelist_db);
if ($database_user) {
$aliases_file = $sendmail_canon = $sendmail_prog =
$recipient_cache_expire = $recipient_cache_check_interval = undef;
syslog("info", "Using shared bogofilter database under %s's account",
$database_user);
}
unlink($socket);
Sendmail::Milter::setconn("local:$socket");
Sendmail::Milter::register("bogofilter-milter",
\%my_milter_callbacks, SMFI_CURR_ACTS);
Sendmail::Milter::main($milter_interpreters);
&closedb;
sub my_helo_callback {
my $ctx = shift;
my $helo = shift;
my $hash = &getpriv($ctx);
$hash->{'helo'} = $helo;
&setpriv($ctx, $hash);
return SMFIS_CONTINUE;
}
sub my_envfrom_callback {
my $ctx = shift;
my $envfrom = shift;
my $hash = &getpriv($ctx);
$hash->{'envfrom'} = $envfrom;
&setpriv($ctx, $hash);
return SMFIS_CONTINUE;
}
sub my_connect_callback {
my $ctx = shift; # milter context object
my $hostname = shift; # The connection's host name.
my $sockaddr_in = shift; # AF_INET portion of the host address,
# from getpeername(2) syscall
my $hash = &getpriv($ctx);
my ($port, $ipaddr) = Socket::unpack_sockaddr_in($sockaddr_in) or
&die("Could not unpack socket address: $!");
$ipaddr = Socket::inet_ntoa($ipaddr); # translates into standard IPv4 addr
$hash->{'remotename'} = $hostname;
$hash->{'remoteip'} = $ipaddr;
$hash->{'localname'} = $ctx->getsymval('j');
$hash->{'localip'} = $ctx->getsymval('{if_addr}');
&debuglog("my_connect_callback: entering with hostname=$hostname, ",
"ipaddr=$ipaddr, port=$port");
# check if the connecting server is listed in the whitelist
if (@ip_whitelist) {
if (eval {Net::CIDR::cidrlookup($ipaddr, @ip_whitelist)}) {
syslog('info', '%s', "$ipaddr is whitelisted, so this email is " .
"being accepted unfiltered.");
&setpriv($ctx, undef);
return SMFIS_ACCEPT;
}
else {
&debuglog("$ipaddr is not in the whitelist");
}
}
# check if connecting server is listed in the popip database
if ($ip_whitelist_db) {
if ($ip_whitelist_db{$ipaddr}) {
syslog('info', '%s', "$ipaddr is authenticated via poprelayd, " .
"so this email is being accepted unfiltered.");
&setpriv($ctx, undef);
return SMFIS_ACCEPT;
}
else {
&debuglog("$ipaddr is not in the popip database");
}
}
$hash->{'ipaddr'} = $ipaddr;
&setpriv($ctx, $hash);
&debuglog("my_connect_callback: return CONTINUE with hash");
return SMFIS_CONTINUE;
}
sub my_rcpt_callback {
my $ctx = shift;
my $envrcpt = shift;
my $hash = &getpriv($ctx);
&debuglog("my_rcpt_callback: entering with " . Data::Dumper->Dump([&small_hash($hash)], [qw(hash)]));
if ($hash->{'rcpt'}) {
# We've already encountered a recipient who is filtering this message.
&setpriv($ctx, $hash);
&debuglog("my_rcpt_callback: return CONTINUE with old hash");
return SMFIS_CONTINUE;
}
my $rcpt = $ctx->getsymval('{rcpt_addr}');
&debuglog("my_rcpt_callback: rcpt_addr: $rcpt");
if (&filtered_dir($rcpt)) {
$hash->{'rcpt'} = $rcpt;
$hash->{'envrcpt'} = $envrcpt;
&setpriv($ctx, $hash);
&debuglog("my_rcpt_callback: return CONTINUE with hash");
return SMFIS_CONTINUE;
}
else {
&setpriv($ctx, undef);
&debuglog("my_rcpt_callback: return CONTINUE with undef");
return SMFIS_CONTINUE;
}
}
sub my_header_callback {
my($ctx, $field, $value) = @_;
my($hash) = &getpriv($ctx);
&debuglog("my_header_callback: entering with " . Data::Dumper->Dump([&small_hash($hash), $field, $value], [qw(hash field value)]));
if (! $hash) {
&debuglog("my_header_callback: return ACCEPT with no hash");
return SMFIS_ACCEPT;
}
if (lc $field eq 'subject') {
if ($value =~ /$magic_string_re/oi) {
&setpriv($ctx, undef);
&debuglog("my_header_callback: returning ACCEPT for magic subject");
return SMFIS_ACCEPT;
}
if ($hash->{'rcpt'}) {
my(@subject_filters) = &user_subject_filters($hash->{'rcpt'});
foreach my $filter (@subject_filters) {
if ($value =~ /$filter/) {
&setpriv($ctx, undef);
&debuglog(sprintf("my_header_callback: returning ACCEPT for subject filter %s for recipient %s",
$filter, $hash->{'rcpt'}));
return SMFIS_ACCEPT;
}
}
}
}
if (lc $field eq 'x-bogosity') {
&debuglog("Found $field: $value");
my $index = $hash->{x_bogosity_index} || 1;
if ($value =~ /tests=bogofilter/) {
unshift(@{$hash->{x_bogosity}}, $index);
&debuglog("my_header_callback: stashing $field: $value ",
"at index $index");
}
$hash->{x_bogosity_index} = $index + 1;
}
$hash = &add_to_message($hash, "$field: $value\n");
&setpriv($ctx, $hash);
&debuglog("my_header_callback: returning CONTINUE with hash");
return SMFIS_CONTINUE;
}
sub my_eoh_callback {
my($ctx) = @_;
my($hash) = &getpriv($ctx);
# If $hash is undefined here, it means that the sender sent no
# message header at all, so the block of code in
# my_header_callback for checking if $hash is undefined never got
# called. This means the message is almost certainly spam, but
# it's not our job to determine that if none of the recipients are
# using bogofilter.
if (! $hash) {
&debuglog("my_eoh_callback: return ACCEPT with no hash (message had empty header)");
return SMFIS_ACCEPT;
}
&debuglog("my_eoh_callback: entering with " . Data::Dumper->Dump([&small_hash($hash)], [qw(hash)]));
$hash = &add_to_message($hash, "\n");
&setpriv($ctx, $hash);
&debuglog("my_eoh_callback: returning CONTINUE with hash");
return SMFIS_CONTINUE;
}
sub my_body_callback {
my($ctx, $body, $len) = @_;
my($hash) = &getpriv($ctx);
&debuglog("my_body_callback: entering with " . Data::Dumper->Dump([&small_hash($hash), $len], [qw(hash len)]));
$hash = &add_to_message($hash, $body);
&setpriv($ctx, $hash);
&debuglog("my_body_callback: returning CONTINUE with hash");
return SMFIS_CONTINUE;
}
sub add_to_message {
my($hash, $text) = @_;
return $hash if (! $text);
if (! $hash->{'fh'}) {
$hash->{'msg'} = '' if (! $hash->{'msg'});
$hash->{'msg'} .= $text;
if (length($hash->{'msg'}) <= $MAX_INCORE_MSG_LENGTH) {
return $hash;
}
($hash->{'fh'}, $hash->{'fn'}) = tempfile();
if (! $hash->{'fn'}) {
&die("error creating temporary file");
}
&debuglog("switching to temporary file " . $hash->{'fn'});
$text = $hash->{'msg'};
delete $hash->{'msg'};
}
if (! print({$hash->{'fh'} } $text)) {
&die("error writing to temporary file " . $hash->{'fn'});
}
return $hash;
}
sub message_read_handle {
my($hash) = @_;
if ($hash->{'fn'}) {
if (! seek($hash->{'fh'}, 0, SEEK_SET)) {
&die("couldn't seek in " . $hash->{'fn'} . ": $!");
}
return $hash->{'fh'};
}
else {
return new IO::Scalar \$hash->{'msg'};
}
}
sub my_eom_callback {
my $ctx = shift;
my $hash = &getpriv($ctx);
my $fh;
local($_);
&debuglog("my_eom_callback: entering with " . Data::Dumper->Dump([&small_hash($hash)], [qw(hash)]));
my $dir = &filtered_dir($hash->{'rcpt'});
if (! $dir) {
# This can happen if the MTA loses the input channel from the sender,
# so it isn't an error condition.
&debuglog("my_eom_callback: called for non-filtered recipient; " . Data::Dumper->Dump([&small_hash($hash)], [qw(hash)]));
&setpriv($ctx, undef);
&debuglog("my_eom_callback: returning ACCEPT with undef");
return SMFIS_ACCEPT;
}
if (defined($filter_script) and &restrict_permissions($hash->{'rcpt'}) and
-x "$dir/$filter_script" and (-o _ or ! (stat(_))[4])) {
my $s = "$dir/$filter_script";
&unrestrict_permissions;
syslog('debug', 'filtering with %s', $s);
my($filter_fh, $filter_fn) = tempfile();
my $stderr_fh = tempfile();
if (! $filter_fn) {
&die("error creating temporary file");
}
$^F = fileno($filter_fh);
pipe(FROMPARENT, FILTER) or &die("pipe: $!\n");
my $pid = fork;
&die("fork: $!\n") if (! defined($pid));
if (! $pid) {
close(FILTER);
if (! open(STDOUT, ">&", $filter_fh)) {
syslog('err', "reopen filter STDOUT to $filter_fn failed: %m");
exit(1);
}
open(STDERR, ">&", $stderr_fh);
if (! open(STDIN, "<&FROMPARENT")) {
syslog('err', "reopen filter STDIN from parent failed: %m");
exit(1);
}
&die("couldn't restrict permissions") if
(! &restrict_permissions($hash->{'rcpt'}, 1));;
$ENV{'MILTER_REMOTE_IP'} = $hash->{'remoteip'} || '';
$ENV{'MILTER_REMOTE_NAME'} = $hash->{'remotename'} || '';
$ENV{'MILTER_HELOHOST'} = $hash->{'helo'} || '';
$ENV{'MILTER_ENVFROM'} = $hash->{'envfrom'} || '';
$ENV{'MILTER_ENVRCPT'} = $hash->{'envrcpt'} || '';
$ENV{'MILTER_LOCAL_IP'} = $hash->{'localip'} || '';
$ENV{'MILTER_LOCAL_NAME'} = $hash->{'localname'} || '';
if (! exec("$s")) {
syslog('err', 'exec(%s) failed: %m', $s);
exit(1);
}
}
close(FROMPARENT);
my $fh = &message_read_handle($hash);
my $good_filter = 1;
while (<$fh>) {
s/\r\n$/\n/;
if (! print(FILTER $_)) {
syslog('info', 'writing to filter %s: %m', $s);
$good_filter = undef;
last;
}
}
my @failed;
if (! close(FILTER)) {
push(@failed, "close(FILTER): $!");
}
if (! waitpid($pid, 0)) {
push(@failed, "waitpid($pid): $!");
}
if ($? >> 8) {
push(@failed, "\$?>>8 == " . ($?>>8));
}
if (@failed and $good_filter) {
syslog('warning', 'filter %s failed: %s', $s, join(", ", @failed));
$good_filter = undef;
}
if (seek($stderr_fh, 0, SEEK_SET) and -s $stderr_fh) {
while (my $error = <$stderr_fh>) {
$error =~ s/^\s+//;
$error =~ s/\s+$//;
syslog('warning', 'stderr output from %s: %s', $s, $error);
}
close($stderr_fh);
}
if ($good_filter) {
delete $hash->{'msg'};
unlink $hash->{'fn'} if ($hash->{'fn'});
$hash->{'fh'} = $filter_fh;
$hash->{'fn'} = $filter_fn;
$hash->{'nocr'} = 1;
syslog('debug', 'successfully filtered with %s', $s);
}
else {
unlink $filter_fn;
close($filter_fh);
}
}
if (! pipe(FROMBOGO, TOPARENT)) {
&die("pipe: $!\n");
}
if (! pipe(FROMPARENT, BOGOFILTER)) {
&die("pipe: $!\n");
}
my $pid = fork;
if (! defined($pid)) {
&die("fork: $!\n");
}
elsif (! $pid) {
close(FROMBOGO);
close(BOGOFILTER);
open(STDOUT, ">&TOPARENT") or
syslog('warning', "reopen STDOUT to parent failed: $!");
open(STDIN, "<&FROMPARENT");
close(TOPARENT);
close(FROMPARENT);
&die("couldn't restrict permissions") if
(! &restrict_permissions($hash->{'rcpt'}, 1));;
my(@cmd) = ('bogofilter', '-v', '-u', '-d', $dir);
if ($bogofilter_cf && -f "$dir/$bogofilter_cf") {
push(@cmd, '-c', "$dir/$bogofilter_cf");
}
exec(@cmd) || &die("exec(bogofilter): $!\n");
# &die had better not return!
}
close(TOPARENT);
close(FROMPARENT);
$fh = &message_read_handle($hash);
if ($hash->{'fn'}) {
# This is safe to do on Unix, since on Unix you can unlink an
# open file and it'll stay around until the last open file
# handle to it goes away. If this script were to be used on
# non-Unix operating systems, which is a big "if" that I'm not
# sure could ever happen, then this unlink might be a problem
# and would need to happen later.
unlink $hash->{'fn'};
}
while (<$fh>) {
s/\r\n$/\n/ if (! $hash->{'nocr'});
print(BOGOFILTER $_) || &die("writing to bogofilter: $!\n");
}
close(BOGOFILTER);
my $bogosity_line = <FROMBOGO>;
close(FROMBOGO);
waitpid $pid, 0;
my $exit_status = $? >> 8;
if ($bogosity_line =~ s/^X-Bogosity:\s*//i) {
chomp $bogosity_line;
}
elsif (! $exit_status) {
$bogosity_line = "Spam, tests=bogofilter";
}
elsif ($exit_status == 1) {
$bogosity_line = "Ham, tests=bogofilter";
}
elsif ($exit_status == 2) {
$bogosity_line = "Unsure, tests=bogofilter";
}
if ($add_unique_id) {
$bogosity_line .=
# I wish we could make this a real UUID, but that would
# require depending on one of the CPAN UUID modules, and I
# don't want to add that dependency just for this feature.
", milter_id=" . sprintf("%lx.%lx.%lx", $$, time(),
int(rand(1000000000)));
}
my $from = $ctx->getsymval('{mail_addr}');
if (! $exit_status) {
my($training);
if ($training_file) {
if (&restrict_permissions($hash->{'rcpt'})) {
$training = (-f "$dir/$training_file");
&unrestrict_permissions;
}
else {
syslog('warning', 'assuming training mode because ' .
'permissions could not be restricted');
$training = 1;
}
}
foreach my $index (@{$hash->{x_bogosity}}) {
&debuglog("Removing old X-Bogosity header");
$ctx->chgheader('X-Bogosity', $index, "");
}
$ctx->addheader('X-Bogosity', $bogosity_line);
my $which = &reject_or_discard($hash);
my($verb) = ($which == SMFIS_REJECT) ? "reject" : "discard";
syslog('info', '%s', ($training ? "would $verb" : "${verb}ing") .
" likely spam from $from to " . $hash->{'rcpt'} . " based on $dir");
&save_copy($fh, $from, $hash->{'rcpt'}, $dir, $archive_mbox,
$bogosity_line, $hash->{'nocr'});
if (! $training) {
$ctx->setreply($rcode, $xcode, $reject_message);
&setpriv($ctx, undef);
return $which;
}
}
else {
&save_copy($fh, $from, $hash->{'rcpt'}, $dir, $ham_archive_mbox,
$bogosity_line, $hash->{'nocr'});
my $bogosity;
if ($exit_status == 1) {
$bogosity = "Ham";
}
elsif ($exit_status == 2) {
$bogosity = "Unsure";
}
if ($bogosity_line || $bogosity) {
foreach my $index (@{$hash->{x_bogosity}}) {
&debuglog("Removing old X-Bogosity header");
$ctx->chgheader('X-Bogosity', $index, "");
}
$ctx->addheader('X-Bogosity', $bogosity_line);
}
}
&setpriv($ctx, undef);
return SMFIS_CONTINUE;
}
sub save_copy {
my($fh, $from, $rcpt, $dir, $archive_mbox, $bogosity, $nocr) = @_;
local($_);
my($archive, $link);
$archive = ($archive_mbox &&
&restrict_permissions($rcpt) &&
(lstat($archive = "$dir/$archive_mbox"))) ?
$archive : undef;
if ($cyrus_deliver && -f $cyrus_deliver && -X $cyrus_deliver &&
-l $archive && ($link = readlink($archive)) &&
$link =~ s/^cyrus:// && (! -f $archive)) {
&unrestrict_permissions;
my $user = &filtered_user($rcpt);
if (! $user) {
&die("Couldn't determine username for IMAP delivery");
}
if (! seek($fh, 0, SEEK_SET)) {
&die("error rewinding message handle: $!");
}
my $pid = open(DELIVER, "|-");
if (! defined($pid)) {
&die("Error forking to execute $cyrus_deliver: $!");
}
elsif (! $pid) {
exec($cyrus_deliver, '-a', $user, '-m',
"user.$user.$link") ||
&die("exec($cyrus_deliver): $!");
}
else {
my ($in_header) = 1;
my $ret = 1;
while ($ret && <$fh>) {
s/\r\n/\n/ if (! $nocr);
if ($in_header) {
next if (/^x-bogosity:.*tests=bogofilter/i);
if (/^$/) {
if ($bogosity) {
$ret = $ret &&
print(DELIVER "X-Bogosity: $bogosity\n");
}
$in_header = 0;
}
}
$ret = $ret && print(DELIVER $_);
}
$ret = $ret && close(DELIVER);
if (! $ret) {
syslog('warning', '%s',
"$cyrus_deliver failed for user.$user.$link");
}
return;
}
}
if ($archive) {
# There is an annoying race condition here. Suppose two spam
# messages are delivered at the same time to a user whose
# archive file is a symlink pointing at a nonexistent (yet)
# file. Milter process A tries to open with +< and fails. IN
# the meantime, process B also tries to open with +< and fails.
# Then A opens witn +>, locks the file and starts writing to
# it, and *then* B opens with +>, thus truncating whatever data
# was written thus far by A. I'm not sure what the best way is
# to fix this race condition reliably, and it seems rare enough
# that it isn't worth the effort.
if (! (open(MBOX, '+<', $archive) ||
open(MBOX, '+>', $archive))) {
syslog('warning', '%s', "opening $archive for " .
"write: $!");
goto no_archive_open;
}
if (! flock(MBOX, LOCK_EX)) {
syslog('warning', '%s', "locking $archive: $!");
goto close_archive;
}
if (! seek(MBOX, 0, SEEK_END)) {
syslog('warning', '%s',
"seek($archive, 0, SEEK_END): $!");
goto close_archive;
}
if (! seek($fh, 0, SEEK_SET)) {
&die("error rewinding message handle: $!");
}
if (! print(MBOX "From " . ($from || 'MAILER-DAEMON') .
" " . localtime() . "\n")) {
syslog('warning', '%s', "write($archive): $!");
goto close_archive;
}
my($last_blank, $last_nl);
my($in_header) = 1;
while (<$fh>) {
s/\r\n/\n/ if (! $nocr);
$last_nl = ($_ =~ /\n/);
$last_blank = ($_ eq "\n");
if ($in_header) {
next if (/^x-bogosity:.*tests=bogofilter/i);
if (/^$/) {
if ($bogosity) {
$_ = "X-Bogosity: $bogosity\n" . $_;
}
$in_header = 0;
}
}
else {
s/^From />From /;
}
if (! print(MBOX $_)) {
syslog('warning', '%s', "write($archive): $!");
goto close_archive;
}
}
# Mbox format requires a blank line at the end
if (! ($last_blank || print(MBOX ($last_nl ? "\n" : "\n\n")))) {
syslog('warning', '%s', "write($archive): $!");
goto close_archive;
}
close_archive:
if (! close(MBOX)) {
syslog('warning', '%s', "close($archive): $!");
}
}
no_archive_open:
&unrestrict_permissions;
}
sub my_abort_callback {
my($ctx) = shift;
my $hash = &getpriv($ctx);
&debuglog("my_abort_callback: entering with " . Data::Dumper->Dump([&small_hash($hash)], [qw(hash)]));
if ($hash->{'fn'}) {
unlink $hash->{'fn'};
}
&setpriv($ctx, undef);
&debuglog("my_abort_callback: returning CONTINUE with undef");
return SMFIS_CONTINUE;
}
sub my_close_callback {
my($ctx) = shift;
my $hash = &getpriv($ctx);
&debuglog("my_close_callback: entering with " . Data::Dumper->Dump([&small_hash($hash)], [qw(hash)]));
if ($hash) {
if ($hash->{'fn'}) {
unlink $hash->{'fn'};
}
}
&setpriv($ctx, undef);
&debuglog("my_close_callback: returning CONTINUE with undef");
return SMFIS_CONTINUE;
}
sub filtered_dir {
my($uid, $gid, $dir) = &expand_recipient($_[0]);
$dir;
}
sub filtered_user {
my($uid, $gid, $dir, $stamp, $user) = &expand_recipient($_[0]);
$user;
}
sub user_subject_filters {
my($uid, $gid, $dir, $stamp, $user, $filters) = &expand_recipient($_[0]);
$filters ? @{$filters} : ();
}
sub restrict_permissions {
my($rcpt) = shift;
my($no_going_back) = shift;
my($uid, $gid, $dir) = &expand_recipient($rcpt);
if (! (defined($uid) && defined($gid))) {
syslog('err', '%s', "internal error: couldn't determine UID and GID " .
"for $rcpt");
return undef;
}
$EUID = $uid;
$EGID = $gid;
if ($no_going_back) {
# When we're ready to exec an external program, i.e.,
# bogofilter, we want to set the real UID and GID so that,
# e.g., bogofilter will look in the correct home directory for
# .bogofilter.cf.
$UID = $uid;
$GID = $gid;
}
1;
}
sub unrestrict_permissions {
$EUID = $UID;
$EGID = $GID;
}
my $recipient_cache_last_checked;
# $uid, $gid, $dir, $timestamp, $username, \@subject_filters
sub expand_recipient {
my($rcpt) = @_;
my($orig, @expanded);
my $now = time;
if ($recipient_cache_expire) {
if (! defined($recipient_cache_last_checked)) {
$recipient_cache_last_checked = $now;
}
if ($now - $recipient_cache_last_checked >
$recipient_cache_check_interval) {
my $old = $now - $recipient_cache_expire;
my(@keys) = keys %cached_recipients;
my(@expired) = grep($cached_recipients{$_}->[3] <= $old,
keys %cached_recipients);
&debuglog('expiring %d entries (out of %d) ' .
'from the recipient cache',
scalar @expired, scalar @keys);
map(delete $cached_recipients{$_}, @expired);
$recipient_cache_last_checked = $now;
}
}
if ($database_user) {
$rcpt = $database_user;
}
if (defined($cached_recipients{$rcpt})) {
return(@{$cached_recipients{$rcpt}});
}
$rcpt = &sendmail_canon($orig = $rcpt);
if ($rcpt =~ /\@/) {
return(@{$cached_recipients{$orig}} = (undef, undef, undef, $now, undef));
}
if ($aliases_file) {
my $aliases = Mail::Alias::Sendmail->new($aliases_file);
@expanded = $aliases->expand($rcpt);
}
else {
@expanded = ($rcpt);
}
if ((@expanded == 1) && ($expanded[0] eq $rcpt)) {
my($dir, $pw);
my $stripped = $rcpt;
$stripped =~ s/\+.*//;
$pw = getpwnam($stripped);
@{$cached_recipients{$orig}} =
$pw ? ($pw->uid, $pw->gid, undef, $now, $stripped) :
(undef, undef, undef, $now, undef);
if ($pw && $pw->dir && &restrict_permissions($orig) &&
-d ($dir = $pw->dir . "/.bogofilter") &&
! ($bogofilter_cf && $require_cf && ! -f "$dir/$bogofilter_cf")) {
$cached_recipients{$orig}->[2] = $dir;
if ($subject_filter_file) {
my $sff = $dir . "/" . $subject_filter_file;
my @subject_filters;
if (open(SFF, "<", $sff)) {
while (<SFF>) {
s/^\s+//;
s/\s+$//;
next if (/^\#/);
next if (/^$/);
my $re;
eval '$re = qr/$_/;';
if (! $re) {
syslog("warning", "bad subject filter for %s: %s",
$stripped, $_);
next;
}
push(@subject_filters, $re);
&debuglog(sprintf('subject filter for %s: %s',
$stripped, $_));
}
}
close(SFF);
if (@subject_filters) {
$cached_recipients{$orig}->[5] = \@subject_filters;
}
}
}
elsif ($database_user) {
syslog("warning", "Shared database user %s is not configured " .
"properly for bogofilter", $database_user);
}
&unrestrict_permissions;
return(@{$cached_recipients{$orig}});
}
else {
foreach my $addr (@expanded) {
my(@sub);
if (@sub = &expand_recipient($addr)) {
return(@{$cached_recipients{$orig}} = @sub);
}
}
return(@{$cached_recipients{$orig}} = (undef, undef, undef, $now, undef));
}
}
sub sendmail_canon {
return $_[0] if (! $sendmail_canon);
my($pid, $sendmail_reader, $sendmail_writer, $last);
local($_);
$pid = open2($sendmail_reader, $sendmail_writer, $sendmail_prog, '-bt') or &die("open2 for sendmail failed");
print($sendmail_writer "3,0 $_[0]\n");
close($sendmail_writer);
while (<$sendmail_reader>) {
# CHECKTHIS You should run "sendmail -bt" as root, give it the
# input "3,0 addr" where "addr" is one of the addresses in
# your virtual user table, and confirm that the last
# "returns:" line that it returns matches the regexp here for
# local addresses.
if (/\s+returns: \$\# local \$\:\s+(.+)/) {
$last = $1;
$last =~ s/ \+ .*//;
}
}
close($sendmail_reader);
waitpid $pid, 0;
if ($last) {
return $last;
}
else {
return $_[0];
}
}
sub opendb_read {
tie(%ip_whitelist_db, "DB_File", $ip_whitelist_db, O_RDONLY, 0, $DB_HASH) or &die("Can't open $ip_whitelist_db: $!");
}
sub closedb {
untie %ip_whitelist_db;
}
sub die {
my(@msg) = @_;
&closedb;
syslog('err', '%s', "@msg");
exit(1);
}
sub debuglog {
syslog('debug', "%s", "DEBUG: " . join("", @_));
}
my(%mx_cache);
sub reject_or_discard {
my($hash) = @_;
my $hostname;
foreach my $i (0..@discard_control-1) {
my($pattern, $action) = @{$discard_control[$i]};
my $ret;
if ($action =~ /^reject$/i) {
$ret = SMFIS_REJECT;
}
elsif ($action =~ /^discard$/i) {
$ret = SMFIS_DISCARD;
}
else {
&die("Invalid action $action ",
"for discard control pttern $pattern\n");
}
if ($pattern =~ /^addr:(.*)$/i) {
my $addr = $1;
&die("Invalid IP address in discard control pattern $pattern\n")
if ($addr !~ /^\d+\.\d+\.\d+\.\d+$/);
if ($hash->{'ipaddr'} eq $addr) {
&debuglog("reject_or_discard: addr match $addr: $action");
return $ret;
}
}
elsif ($pattern =~ /^netblock:(.*)$/i) {
my $netblock = $1;
&die("Invalid netblock in discard control pattern $pattern\n")
if ($netblock !~ /^\d+\.\d+\.\d+\.\d+\/\d+$/);
if (Net::CIDR::cidrlookup($hash->{'ipaddr'}, $netblock)) {
&debuglog("reject_or_discard: netblock match ",
"$hash->{ipaddr} in $netblock: $action");
return $ret;
}
}
elsif ($pattern =~ /^host:(.*)$/i) {
my $match_host = lc $1;
$hostname = lc gethostbyaddr(inet_aton($hash->{ipaddr}), AF_INET)
if (! $hostname);
if ($match_host eq $hostname) {
&debuglog("reject_or_discard: ",
"host match $hostname for $hash->{ipaddr}: ",
"$action and cache");
splice(@discard_control, $i, 0,
[ "addr:$hash->{ipaddr}", $action ]);
return $ret;
}
}
elsif ($pattern =~ /^domain:(.*)$/i) {
my $match_domain = lc $1;
$hostname = lc gethostbyaddr(inet_aton($hash->{ipaddr}), AF_INET)
if (! $hostname);
if ($match_domain eq $hostname or
(substr($hostname, -1-length($match_domain)) eq
".$match_domain")) {
&debuglog("reject_or_discard: domain match ",
"$hostname for $hash->{ipaddr} in $match_domain: ",
"$action and cache");
splice(@discard_control, $i, 0,
[ "addr:$hash->{ipaddr}", $action ]);
return $ret;
}
}
elsif ($pattern =~ /^mx$/i) {
my $mx_domain = lc $hash->{'envrcpt'};
if (! $mx_domain) {
&debuglog("reject_or_discard: no envrcpt\n");
next;
}
$mx_domain =~ s/.*\@(.*[^\>])\>?/$1/;
my %mx_ips;
if ($mx_cache{$mx_domain} and
# refetch MX records once per hour
time - $mx_cache{$mx_domain}->[0] < 60 * 60) {
%mx_ips = %{$mx_cache{$mx_domain}->[1]};
}
else {
my %mx_ips;
foreach my $mx (mx($mx_domain)) {
my($name, $aliases, $addrtype, $length, @addrs) =
gethostbyname($mx->exchange);
foreach my $addr (@addrs) {
$mx_ips{inet_ntoa($addr)} = 1;
}
}
$mx_cache{$mx_domain} = [time, \%mx_ips];
&debuglog("reject_or_discard: cached MX IPs ",
join(" ", sort keys %mx_ips),
" for domain $mx_domain");
}
if ($mx_ips{$hash->{'ipaddr'}}) {
&debuglog("reject_or_discard: MX addr match ",
"$hash->{ipaddr} for domain $mx_domain: $action");
return $ret;
}
}
elsif ($pattern eq "*") {
return $ret;
}
else {
&die("Unrecognized discard control pattern: $pattern");
}
}
return SMFIS_REJECT;
}
sub getpriv {
my($ctx) = @_;
my $d = $ctx->getpriv();
my $VAR1;
if ($d) {
eval $d;
}
else {
undef;
}
}
sub setpriv {
my($ctx, $value) = @_;
if (defined $value) {
my $d = Dumper($value);
$ctx->setpriv($d);
}
else {
$ctx->setpriv(undef);
}
}
sub small_hash {
my($hash) = @_;
return undef if (! $hash);
my(%hash2) = %{$hash};
$hash2{'msg'} = "..." if ($hash2{'msg'} and length($hash2{'msg'}) > 100);
\%hash2;
}
|