1.\" Copyright (c) 1983, 1986, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)syslogd.8 8.1 (Berkeley) 6/6/93 33.\" $FreeBSD: src/usr.sbin/syslogd/syslogd.8,v 1.22.2.16 2003/03/12 22:08:15 trhodes Exp $ 34.\" $DragonFly: src/usr.sbin/syslogd/syslogd.8,v 1.2 2003/06/17 04:30:03 dillon Exp $ 35.\" 36.Dd November 24, 2001 37.Dt SYSLOGD 8 38.Os 39.Sh NAME 40.Nm syslogd 41.Nd log systems messages 42.Sh SYNOPSIS 43.Nm 44.Op Fl 46Acdknsuv 45.Op Fl a Ar allowed_peer 46.Op Fl b Ar bind_address 47.Op Fl f Ar config_file 48.Op Fl l Ar path 49.Op Fl m Ar mark_interval 50.Op Fl P Ar pid_file 51.Op Fl p Ar log_socket 52.Sh DESCRIPTION 53The 54.Nm 55utility reads and logs messages to the system console, log files, other 56machines and/or users as specified by its configuration file. 57.Pp 58The options are as follows: 59.Bl -tag -width indent 60.It Fl 4 61Force 62.Nm 63to use IPv4 addresses only. 64.It Fl 6 65Force 66.Nm 67to use IPv6 addresses only. 68.It Fl A 69Ordinarily, 70.Nm 71tries to send the message to only one address 72even if the host has more than one A or AAAA record. 73If this option is specified, 74.Nm 75tries to send the message to all addresses. 76.It Fl a Ar allowed_peer 77Allow 78.Ar allowed_peer 79to log to this 80.Nm 81using UDP datagrams. Multiple 82.Fl a 83options may be specified. 84.Pp 85.Ar Allowed_peer 86can be any of the following: 87.Bl -tag -width "ipaddr/masklen[:service]XX" 88.It Xo 89.Sm off 90.Ar ipaddr 91.No / Ar masklen 92.Op : Ar service 93.Sm on 94.Xc 95Accept datagrams from 96.Ar ipaddr 97(in the usual dotted quad notation) with 98.Ar masklen 99bits being taken into account when doing the address comparison. 100.Ar ipaddr 101can be also IPv6 address by enclosing the address with 102.Ql \&[ 103and 104.Ql \&] . 105If specified, 106.Ar service 107is the name or number of an UDP service (see 108.Xr services 5 ) 109the source packet must belong to. A 110.Ar service 111of 112.Ql \&* 113allows packets being sent from any UDP port. The default 114.Ar service 115is 116.Ql syslog . 117If 118.Ar ipaddr 119is IPv4 address, a missing 120.Ar masklen 121will be substituted by the historic class A or class B netmasks if 122.Ar ipaddr 123belongs into the address range of class A or B, respectively, or 124by 24 otherwise. If 125.Ar ipaddr 126is IPv6 address, a missing 127.Ar masklen 128will be substituted by 128. 129.It Xo 130.Sm off 131.Ar domainname Op : Ar service 132.Sm on 133.Xc 134Accept datagrams where the reverse address lookup yields 135.Ar domainname 136for the sender address. The meaning of 137.Ar service 138is as explained above. 139.It Xo 140.Sm off 141.No * Ar domainname Op : Ar service 142.Sm on 143.Xc 144Same as before, except that any source host whose name 145.Em ends 146in 147.Ar domainname 148will get permission. 149.El 150.Pp 151The 152.Fl a 153options are ignored if the 154.Fl s 155option is also specified. 156.It Fl b Ar bind_address 157Specify one specific IP address or hostname to bind to. 158If a hostname is specified, 159the IPv4 or IPv6 address which corresponds to it is used. 160.It Fl c 161Disable the compression of repeated instances of the same line 162into a single line of the form 163.Dq Li "last message repeated N times" 164when the output is a pipe to another program. 165If specified twice, disable this compression in all cases. 166.It Fl d 167Put 168.Nm 169into debugging mode. This is probably only of use to developers working on 170.Nm . 171.It Fl f 172Specify the pathname of an alternate configuration file; 173the default is 174.Pa /etc/syslog.conf . 175.It Fl k 176Disable the translation of 177messages received with facility 178.Dq kern 179to facility 180.Dq user . 181Usually the 182.Dq kern 183facility is reserved for messages read directly from 184.Pa /dev/klog . 185.It Fl m 186Select the number of minutes between 187.Dq mark 188messages; the default is 20 minutes. 189.It Fl n 190Disable dns query for every request. 191.It Fl p 192Specify the pathname of an alternate log socket to be used instead; 193the default is 194.Pa /var/run/log . 195.It Fl P 196Specify an alternative file in which to store the process ID. 197The default is 198.Pa /var/run/syslog.pid . 199.It Fl l 200Specify a location where 201.Nm 202should place an additional log socket. 203Up to 19 additional logging sockets can be specified. 204The primary use for this is to place additional log sockets in 205.Pa /var/run/log 206of various chroot filespaces. 207.It Fl s 208Operate in secure mode. Do not log messages from remote machines. If 209specified twice, no network socket will be opened at all, which also 210disables logging to remote machines. 211.It Fl u 212Unique priority logging. Only log messages at the specified priority. 213Without this option, messages at the stated priority or higher are logged. 214This option changes the default comparison from 215.Dq => 216to 217.Dq = . 218.It Fl v 219Verbose logging. If specified once, the numeric facility and priority are 220logged with each locally-written message. If specified more than once, 221the names of the facility and priority are logged with each locally-written 222message. 223.El 224.Pp 225The 226.Nm 227utility reads its configuration file when it starts up and whenever it 228receives a hangup signal. 229For information on the format of the configuration file, 230see 231.Xr syslog.conf 5 . 232.Pp 233The 234.Nm 235utility reads messages from the 236.Ux 237domain socket 238.Pa /var/run/log , 239from an Internet domain socket specified in 240.Pa /etc/services , 241and from the special device 242.Pa /dev/klog 243(to read kernel messages). 244.Pp 245The 246.Nm 247utility creates its process ID file, 248by default 249.Pa /var/run/syslog.pid , 250and stores its process 251ID there. 252This can be used to kill or reconfigure 253.Nm . 254.Pp 255The message sent to 256.Nm 257should consist of a single line. 258The message can contain a priority code, which should be a preceding 259decimal number in angle braces, for example, 260.Sq Aq 5 . 261This priority code should map into the priorities defined in the 262include file 263.Aq Pa sys/syslog.h . 264.Pp 265For security reasons, 266.Nm 267will not append to log files that do not exist; 268therefore, they must be created manually before running 269.Nm . 270.Sh FILES 271.Bl -tag -width /var/run/syslog.pid -compact 272.It Pa /etc/syslog.conf 273configuration file 274.It Pa /var/run/syslog.pid 275default process ID file 276.It Pa /var/run/log 277name of the 278.Ux 279domain datagram log socket 280.It Pa /dev/klog 281kernel log device 282.El 283.Sh SEE ALSO 284.Xr logger 1 , 285.Xr syslog 3 , 286.Xr services 5 , 287.Xr syslog.conf 5 288.Sh HISTORY 289The 290.Nm 291utility appeared in 292.Bx 4.3 . 293.Pp 294The 295.Fl a , 296.Fl s , 297.Fl u , 298and 299.Fl v 300options are 301.Fx 2.2 302extensions. 303.Sh BUGS 304The ability to log messages received in UDP packets is equivalent to 305an unauthenticated remote disk-filling service, and should probably be 306disabled by default. Some sort of 307.No inter- Ns Nm syslogd 308authentication mechanism ought to be worked out. To prevent the worst 309abuse, use of the 310.Fl a 311option is therefore highly recommended. 312.Pp 313The 314.Fl a 315matching algorithm doesn't pretend to be very efficient; use of numeric 316IP addresses is faster than domain name comparison. Since the allowed 317peer list is being walked linearly, peer groups where frequent messages 318are being anticipated from should be put early into the 319.Fl a 320list. 321.Pp 322The log socket was moved from 323.Pa /dev 324to ease the use of a read-only root file system. 325This may confuse 326some old binaries so that a symbolic link might be used for a 327transitional period. 328