/usr/share/doc/samhain/manual.html/logmon.html is in samhain 2.8.3a-1.
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 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>Logfile monitoring/analysis</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REL="HOME"
TITLE="The Samhain Host Integrity Monitoring System"
HREF="index.html"><LINK
REL="UP"
TITLE="Configuring samhain, the host integrity monitor"
HREF="file-monitor.html"><LINK
REL="PREVIOUS"
TITLE="Checking for open ports"
HREF="portcheck.html"><LINK
REL="NEXT"
TITLE="Checking the Windows registry"
HREF="winreg.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="./docbook.css"></HEAD
><BODY
CLASS="SECT1"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>The Samhain Host Integrity Monitoring System</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="portcheck.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
>Chapter 5. Configuring <SPAN
CLASS="APPLICATION"
>samhain</SPAN
>, the host integrity monitor</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="winreg.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="LOGMON"
>5.16. Logfile monitoring/analysis</A
></H1
><P
> This option is available with <SPAN
CLASS="APPLICATION"
>samhain</SPAN
> version
2.5.0 and higher. To compile with support for this option, use the
configure option
</P
><P
> <B
CLASS="COMMAND"
>./configure --enable-logfile-monitor</B
>
</P
><DIV
CLASS="NOTE"
><P
></P
><TABLE
CLASS="NOTE"
WIDTH="100%"
BORDER="0"
><TR
><TD
WIDTH="25"
ALIGN="CENTER"
VALIGN="TOP"
><IMG
SRC="./stylesheet-images/note.gif"
HSPACE="5"
ALT="Note"></TD
><TH
ALIGN="LEFT"
VALIGN="MIDDLE"
><B
>PCRE library required</B
></TH
></TR
><TR
><TD
> </TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
> This option requires the PCRE (Perl Compatible Regular Expressions)
library. Many Linux distributions split library packages into a
runtime package (required to run a dependent executable) and a
development package (required to compile an executable). At least
on the build host where <SPAN
CLASS="APPLICATION"
>samhain</SPAN
> is
compiled, the development package is required if you use this option.
</P
></TD
></TR
></TABLE
></DIV
><P
> This module enables <SPAN
CLASS="APPLICATION"
>samhain</SPAN
> to
monitor/analyze
logfiles of other applications. Currently
(<SPAN
CLASS="APPLICATION"
>samhain</SPAN
> 2.5.0) the following
logfile formats are supported:
<P
></P
><UL
><LI
><P
> Syslog
</P
></LI
><LI
><P
> Apache (access and error log)
</P
></LI
><LI
><P
> Samba
</P
></LI
><LI
><P
> 'pacct' BSD-style process accounting (also available on Linux)
</P
></LI
></UL
>
</P
><P
> Logfile analysis will always start from the point the last one
ended; the pointer into the file is stored persistently on disk.
Logfile rotation is handled automatically as long as the rotated
logfile remains in the same directory and is
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>not compressed</I
></SPAN
> (usually log rotation tools
can be configured to compress only after the second rotation,
which is advisable for unrelated reasons - the logging application
may still have an open file pointer after logfile rotation).
</P
><P
> Logfile entries can be filtered with Perl-style
regular expressions (filter rules). Regular expressions must
match <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>the whole logfile record</I
></SPAN
>.
For efficiency, regular expressions can be grouped under a common
regular expression, i.e. if the group expression fails to match,
no RE in the group is tried. Furthermore, (groups of) regular expressions
can be grouped by host, if the logfile(s) contain host information
(such as host information in centralized syslog server logfiles,
or virtual host information in Apache logfiles). Note that
host->group->rule is supported (just as host->rule or
group->rule), while group->host->>rule
isn't.
</P
><P
> Each filtering rule (regular expression) is assigned to an output
queue. Currently (<SPAN
CLASS="APPLICATION"
>samhain</SPAN
> 2.5.0) queues
only differ in the assigned severity of an event, but more options
(per-queue mail addresses for alerts) are under development.
</P
><P
> Filtering rules are processed in the order given in the configuration
file, i.e. the first match wins.
</P
><DIV
CLASS="NOTE"
><P
></P
><TABLE
CLASS="NOTE"
WIDTH="100%"
BORDER="0"
><TR
><TD
WIDTH="25"
ALIGN="CENTER"
VALIGN="TOP"
><IMG
SRC="./stylesheet-images/note.gif"
HSPACE="5"
ALT="Note"></TD
><TH
ALIGN="LEFT"
VALIGN="MIDDLE"
><B
>Blacklisting vs. whitelisting, and the 'trash' output queue</B
></TH
></TR
><TR
><TD
> </TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
> Output queues are labelled. The label 'trash' is reserved and
refers to the trash bin (no output, throw away log entries
if the matching rule is assigned to the 'trash' queue).
</P
><P
> If a logfile entry does not match any rule, it is reported
(i.e. the default is <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>whitelisting</I
></SPAN
> known-good
entries). To
turn this into a <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>blacklisting</I
></SPAN
> policy, simply
add a catch-all rule at the end and assign it to the 'trash' queue.
</P
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN2828"
>5.16.1. Event Correlation</A
></H2
><P
> Sometimes it is desirable to report on the fact that several events
happend at a similar time, possibly in a particular order. As of
version 2.6.1, <SPAN
CLASS="APPLICATION"
>samhain</SPAN
> supports this in the
following way:
</P
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="AEN2832"
>5.16.1.1. Marking individual events to be correlated</A
></H3
><P
> First, individual events to be correlated need to be marked for
keeping them, under an arbitrary user-defined label, for an arbitrary
user-defined time. So the rule for matching an event has to be
modified like this:
</P
><P
> <B
CLASS="COMMAND"
>LogmonRule=KEEP(<TT
CLASS="REPLACEABLE"
><I
>seconds,label</I
></TT
>):<TT
CLASS="REPLACEABLE"
><I
>queue_label</I
></TT
>:<TT
CLASS="REPLACEABLE"
><I
>(perl)regex</I
></TT
></B
>
matches a logfile entry against the provided regular expression, AND keeps
it for the specified time in <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>seconds</I
></SPAN
>, with the specified
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>label</I
></SPAN
>. In other words, processing of this rule will
be no different than other rules, except for the fact that also a memory of
the event is kept for the specified amount of time. So if you e.g. don't
want a separate report for this individual event, just assign it to
the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>trash</I
></SPAN
> queue.
</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="AEN2843"
>5.16.1.2. Correlating the marked events</A
></H3
><P
> To correlate events labelled <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>label_one</I
></SPAN
>,
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>label_two</I
></SPAN
>, etc., just build a regular expression
that matches the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>labels</I
></SPAN
>, in the temporal order
you want to check for. E.g. if the temporal order is irrelevant, you
may want to match
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>(label_one.*label_two)|(label_two.*label_one)</I
></SPAN
>.
Use this expression in a rule maked as
CORRELATE(<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>description</I
></SPAN
>), like this:
</P
><P
> <B
CLASS="COMMAND"
>LogmonRule=CORRELATE(<TT
CLASS="REPLACEABLE"
><I
>description</I
></TT
>):<TT
CLASS="REPLACEABLE"
><I
>queue_label</I
></TT
>:<TT
CLASS="REPLACEABLE"
><I
>(perl)regex</I
></TT
></B
>
</P
><DIV
CLASS="NOTE"
><P
></P
><TABLE
CLASS="NOTE"
WIDTH="100%"
BORDER="0"
><TR
><TD
WIDTH="25"
ALIGN="CENTER"
VALIGN="TOP"
><IMG
SRC="./stylesheet-images/note.gif"
HSPACE="5"
ALT="Note"></TD
><TH
ALIGN="LEFT"
VALIGN="MIDDLE"
><B
>Old records in existing logfiles</B
></TH
></TR
><TR
><TD
> </TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
> Because the 'keep' timeout is relative to the current time, correlation
of old entries in logfiles (i.e. when, at startup, an existing logfile
with old entries is scanned) will only work if you specify 'keep'
timeouts that are long enough to cover the whole timespan from the
first logfile record until now.
</P
></TD
></TR
></TABLE
></DIV
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN2859"
>5.16.2. Reporting non-occurence of an event</A
></H2
><P
> To check whether a given event occurs at least once within some
given interval, the rule for matching an event can be modified
like this:
</P
><P
> <B
CLASS="COMMAND"
>LogmonRule=MARK(<TT
CLASS="REPLACEABLE"
><I
>seconds,description</I
></TT
>):<TT
CLASS="REPLACEABLE"
><I
>queue_label</I
></TT
>:<TT
CLASS="REPLACEABLE"
><I
>(perl)regex</I
></TT
></B
>
matches a logfile entry against the provided regular expression, AND
checks whether is occurs at least once within the specified interval
(seconds).
</P
><P
> Processing of this rule will
be no different than other rules otherwise, so if you e.g. only
want a report for this event if it is missing, just assign it to
the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>trash</I
></SPAN
> queue. However, in the latter case
the severity for reporting the messages must be set separately
with the LogmonMarkSeverity directive, because the 'trash' queue
has no severity assigned:
</P
><P
> <B
CLASS="COMMAND"
>LogmonMarkSeverity=<TT
CLASS="REPLACEABLE"
><I
>severity</I
></TT
></B
> — Severity for reports on missing heartbeat messages if the messages themselves are assigned to the 'trash' queue (default: crit).
</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN2872"
>5.16.3. Reporting bursts of similar, repeated events</A
></H2
><P
> <SPAN
CLASS="APPLICATION"
>Samhain</SPAN
> can automatically detect and report
bursts of similar, repeated events in the monitored logfiles. Here
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>similar, repeated events</I
></SPAN
> refers to events that
differ (only) in details that can be expected to differ for
events of the same kind: IP adresses, FQDNs, email adresses, and numbers.
The event history goes back 12 minutes, and
thus a report is triggered if the number of similar events within the last
12 minutes exceeds a given threshold (default: 24).
</P
><P
> This feature is <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>off</I
></SPAN
> by default. In order to
switch it on, you need to set a reporting queue:
</P
><P
> <B
CLASS="COMMAND"
>LogmonBurstQueue=<TT
CLASS="REPLACEABLE"
><I
>queue</I
></TT
></B
> — Set the reporting queue for reporting bursts of similar log messages (default: don't report).
</P
><P
> In addition, there are two more configurable parameters, one to
set the triggering threshold (i.e. the number of messages within
12 minutes that need to be exceeded to raise an alert), and another
one to indicate whether messages from the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>cron</I
></SPAN
>
daemon should be considered as well (default: no):
</P
><P
> <B
CLASS="COMMAND"
>LogmonBurstThreshold=<TT
CLASS="REPLACEABLE"
><I
>number</I
></TT
></B
> — The number of repeated messages within 12 minutes that must be exceeded to report a burst of repeated messages (default: 24).
</P
><P
> <B
CLASS="COMMAND"
>LogmonBurstCron=<TT
CLASS="REPLACEABLE"
><I
>boolean</I
></TT
></B
> — Whether to report also on bursts of repeated cron messages (default: false).
</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN2890"
>5.16.4. Options</A
></H2
><P
> <B
CLASS="COMMAND"
>LogmonActive=<TT
CLASS="REPLACEABLE"
><I
>boolean</I
></TT
></B
> switches
this module on or off (default: off).
</P
><P
> <B
CLASS="COMMAND"
>LogmonSaveDir=<TT
CLASS="REPLACEABLE"
><I
>/absolute/path</I
></TT
></B
>
sets the directory where checkpoint data for logfiles is stored (default:
same as for database file).
</P
><P
> <B
CLASS="COMMAND"
>LogmonClean=<TT
CLASS="REPLACEABLE"
><I
>boolean</I
></TT
></B
>
delete old checkpoint data unmodified for 30 days or more (default: off).
</P
><P
> <B
CLASS="COMMAND"
>LogmonInterval=<TT
CLASS="REPLACEABLE"
><I
>seconds</I
></TT
></B
> sets the
interval for logfile checking (default: 10 seconds).
</P
><P
> <B
CLASS="COMMAND"
>LogmonMarkSeverity=<TT
CLASS="REPLACEABLE"
><I
>severity</I
></TT
></B
> — Severity for reports on missing heartbeat messages if the messages themselves are assigned to the 'trash' queue (default: crit).
</P
><P
> <B
CLASS="COMMAND"
>LogmonBurstThreshold=<TT
CLASS="REPLACEABLE"
><I
>number</I
></TT
></B
> — The number of repeated messages within 12 minutes that must be exceeded to report a burst of repeated messages (default: 24).
</P
><P
> <B
CLASS="COMMAND"
>LogmonBurstQueue=<TT
CLASS="REPLACEABLE"
><I
>queue</I
></TT
></B
> — Set the reporting queue for reporting bursts of similar log messages (default: don't report).
</P
><P
> <B
CLASS="COMMAND"
>LogmonBurstCron=<TT
CLASS="REPLACEABLE"
><I
>boolean</I
></TT
></B
> — Whether to report also on bursts of repeated cron messages (defaul: false).
</P
><P
> <B
CLASS="COMMAND"
>LogmonWatch=<TT
CLASS="REPLACEABLE"
><I
>TYPE:path[:format]</I
></TT
></B
>
advises the module to monitor the logfile with the specified <TT
CLASS="FILENAME"
>path</TT
>,
which is of type 'TYPE' (logfile types are uppercase).
Some logfile types (e.g. Apache access logs) can be
customized, and hence some <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>format</I
></SPAN
> information must be provided. Currently
(<SPAN
CLASS="APPLICATION"
>samhain</SPAN
> 2.6.4) the following logfile types are supported
<P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
>SYSLOG</DT
><DD
><P
> Standard UNIX style syslog files. Matching starts at the command (i.e. after
the hostname). To select certain hostnames, place the rule under a LogmonHost
directive (see below). If the LogmonHidePID option is used, the RE should not
account for the process PID.
</P
></DD
><DT
>APACHE</DT
><DD
><P
> Apache (or compatible) webserver access and/or error logs. Required
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>format</I
></SPAN
> information: either one
of <TT
CLASS="REPLACEABLE"
><I
>combined</I
></TT
>,
<TT
CLASS="REPLACEABLE"
><I
>common</I
></TT
>, or <TT
CLASS="REPLACEABLE"
><I
>error</I
></TT
>
(error log), or the Apache custom log format specification used. The
whole log line is matched. If there are virtual hosts (%v), then
the LogmonHost directive will match the virtual host.
</P
></DD
><DT
>SAMBA</DT
><DD
><P
> Samba logfile format (multiline, timestamp and origin within samba source code
on first line, log message on continuation lines). The RE will match the
continuation line (with the log message) only.
</P
></DD
><DT
>PACCT</DT
><DD
><P
> BSD style process accounting (also available on Linux). This is a binary
logfile. The module will build a text line like the 'last' command does,
and match it against the RE.
</P
><P
> <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>What is pacct good for?</I
></SPAN
> Note that pacct records
contain only the executable name, not the arguments.
This may look somewhat useless for shell accounts, but is quite useful
for servers: how many different commands can e.g. <SPAN
CLASS="APPLICATION"
>postfix</SPAN
>
legitimately execute? Just a handful, indeed, and certainly none of them
is /bin/sh! So if pacct says that the 'postfix' user has executed a shell, then
this would be rather alarming...
</P
></DD
><DT
>SHELL</DT
><DD
><P
> A shell command. The full output on stdout will be read and matched. The PATH
environment variable will be set to <TT
CLASS="REPLACEABLE"
><I
>/sbin:/bin:/usr/sbin:/usr/bin:/usr/ucb</I
></TT
>,
and the SHELL, IFS, and TZ variables will be defined. The command is executed
via <B
CLASS="COMMAND"
>/bin/sh -c <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
></B
>.
</P
></DD
></DL
></DIV
>
</P
><P
> <B
CLASS="COMMAND"
>LogmonHidePID=<TT
CLASS="REPLACEABLE"
><I
>boolean</I
></TT
></B
> is an option
that only affects logfiles of type SYSLOG. It causes the PID to be stripped
from the log line (before matching against the RE).
</P
><P
> <B
CLASS="COMMAND"
>LogmonQueue=<TT
CLASS="REPLACEABLE"
><I
>label:[interval]:(sum|report):severity[:alias]</I
></TT
></B
>
defines an output queue. Here, <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>label</I
></SPAN
> is an arbitrary
name which is used to assign rules to this queue;
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>interval</I
></SPAN
> is the timespan over
which messages are summarized if the queue is of type 'sum';
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>sum</I
></SPAN
> (summarize over some interval) or
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>report</I
></SPAN
> (report each event seperately and immediately)
are the two
queue type supported, and <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>severity</I
></SPAN
> is the severity
assigned to an event. Furthermore, optionally it is possible to
specify an <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>alias</I
></SPAN
> (must be defined in the email
configuration) to direct email for this rule to a specific list
of recipients.
</P
><DIV
CLASS="NOTE"
><P
></P
><TABLE
CLASS="NOTE"
WIDTH="100%"
BORDER="0"
><TR
><TD
WIDTH="25"
ALIGN="CENTER"
VALIGN="TOP"
><IMG
SRC="./stylesheet-images/note.gif"
HSPACE="5"
ALT="Note"></TD
><TH
ALIGN="LEFT"
VALIGN="MIDDLE"
><B
>Email</B
></TH
></TR
><TR
><TD
> </TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
> If you spefify a list alias, email will still go to all defined
email recipients unless filtered, e.g. with
</P
><PRE
CLASS="PROGRAMLISTING"
> SetMailFilterNot = \[Logfile\]
</PRE
><P
> I.e. you may want to define recipients, filter them as above, and
then define list aliases to be used in an event queue. See
<A
HREF="configuration-email.html"
>Section 4.4</A
>> for more information.
</P
></TD
></TR
></TABLE
></DIV
><P
> <B
CLASS="COMMAND"
>LogmonHost=<TT
CLASS="REPLACEABLE"
><I
>(perl)regex</I
></TT
></B
> causes
the following rules to be applied only to entries for this host(s). It is ended
implicitely by another LogmonHost directive, or explicitely by a LogmonEndHost
directive.
</P
><P
> <B
CLASS="COMMAND"
>LogmonEndHost</B
> explicitely ends a preceding LogmonHost
directive.
</P
><P
> <B
CLASS="COMMAND"
>LogmonGroup=<TT
CLASS="REPLACEABLE"
><I
>(perl)regex</I
></TT
></B
> causes
the following rules to be applied only if the group regex matches (i.e. rules
within the group are skipped if the group regex doesn't match. This can be used
to improve speed/efficiency of matching, i.e. you can group regexes by a common
prefix. A group is ended
implicitely by another LogmonGroup directive, or explicitely by a LogmonEndGroup
directive.
</P
><P
> <B
CLASS="COMMAND"
>LogmonEndGroup</B
> explicitely ends a preceding LogmonGroup
directive.
</P
><P
> <B
CLASS="COMMAND"
>LogmonRule=<TT
CLASS="REPLACEABLE"
><I
>queue_label:(perl)regex</I
></TT
></B
>
matches a logfile entry against the provided regular expression. If the expression
matches, then <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>captured</I
></SPAN
> subexpressions are replaced
by '___', and the logfile entry is reported as specified for the queue referenced
by <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>queue_label</I
></SPAN
>. Non-captured subexpressions (i.e.
subexpressions where the opening bracket is followed by '?:') are
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>not replaced</I
></SPAN
> by '___', but reported literally.
</P
><P
> <B
CLASS="COMMAND"
>LogmonRule=KEEP(<TT
CLASS="REPLACEABLE"
><I
>seconds,label</I
></TT
>):<TT
CLASS="REPLACEABLE"
><I
>queue_label:(perl)regex</I
></TT
></B
>
as above, but additionally keep the event <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>label</I
></SPAN
> for
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>seconds</I
></SPAN
> to perform event correlation.
</P
><P
> <B
CLASS="COMMAND"
>LogmonRule=CORRELATE(<TT
CLASS="REPLACEABLE"
><I
>description</I
></TT
>):<TT
CLASS="REPLACEABLE"
><I
>queue_label</I
></TT
>:<TT
CLASS="REPLACEABLE"
><I
>(perl)regex</I
></TT
></B
> perform
event correlation by matching the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>labels</I
></SPAN
> (as specified
in KEEP rules) of a sequence of events against the given regular expression.
</P
><P
> <B
CLASS="COMMAND"
>LogmonRule=MARK(<TT
CLASS="REPLACEABLE"
><I
>seconds,description</I
></TT
>):<TT
CLASS="REPLACEABLE"
><I
>queue_label</I
></TT
>:<TT
CLASS="REPLACEABLE"
><I
>(perl)regex</I
></TT
></B
>
matches a logfile entry against the provided regular expression, AND
checks whether is occurs at least once within the specified interval
(seconds).
</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN3004"
>5.16.5. Example configuration</A
></H2
><PRE
CLASS="PROGRAMLISTING"
> [Logmon]
#
# Switch on the module
#
LogmonActive = yes
# Check every second
#
LogmonInterval = 1
# Strip PIDs from syslog messages
#
Logmonhidepid = true
# Define a queue with severity 'crit'.
# This is a 'report' queue, hence 'interval' (10)
# will be ignored.
#
LogmonQueue = q1:10:report:crit
# Define a second queue with severity 'alert'
#
LogmonQueue = q2:10:report:alert
# Monitor /var/log/messages, which is a syslog file
#
LogmonWatch = SYSLOG:/var/log/messages
# Monitor /var/log/samba/log.nmbd, which is a samba
# logfile
#
LogmonWatch = SAMBA:/var/log/samba/log.nmbd
# Monitor /var/log/apache2/access.log, which is
# an Apache logfile in 'combined' format
#
LogmonWatch = APACHE:/var/log/apache2/access.log:combined
# Monitor disks to check for full /dev/sda1
#
LogmonWatch = SHELL:df -h
# Syslog messages for the pppd deamon
#
LogmonGroup = g1:pppd.*
#
# Rules in this group
#
LogmonRule = q1:pppd:\s+primary.*
LogmonRule = q1:pppd:\s+secondary.*
#
LogmonEndGroup
# Warn about disk /dev/sda1 nearly full (80% or more. Use a
# non-capturing subexpression [the (?:8|9)] for the percentage full.
#
LogmonRule = q1:/dev/sda1\s+[0-9GM.]+\s+[0-9GM.]+\s+[0-9GM.]+\s+(?:8|9).%.*
# Messages starting with WARNING (some samba stuff)
#
LogmonGroup = g2:WARNING.*
LogmonRule = q2:.*interfaces.*
LogmonEndGroup
# Throw away all non-matching entries. This amounts
# to a blacklist policy (only report known bad).
#
# Usually considered bad practice!!! Use whitelisting!
#
# 'trash' is a built in queue, no definition needed.
#
LogmonRule = trash:.*
</PRE
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="portcheck.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="winreg.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Checking for open ports</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="file-monitor.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Checking the Windows registry</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
|