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.\" $Id: syslogd.8,v 1.16 1998/07/22 06:15:18 phk Exp $ 34.\" 35.Dd October 12, 1995 36.Dt SYSLOGD 8 37.Os BSD 4.2 38.Sh NAME 39.Nm syslogd 40.Nd log systems messages 41.Sh SYNOPSIS 42.Nm 43.Op Fl dsuv 44.Op Fl a Ar allowed_peer 45.Op Fl f Ar config_file 46.Op Fl m Ar mark_interval 47.Op Fl p Ar log_socket 48.Op Fl l Ar path 49.Sh DESCRIPTION 50The 51.Nm 52daemon reads and logs messages to the system console, log files, other 53machines and/or users as specified by its configuration file. 54The options are as follows: 55.Bl -tag -width indent 56.It Fl a Ar allowed_peer 57Allow 58.Ar allowed_peer 59to log to this 60.Nm 61using UDP datagrams. Multiple 62.Fl a 63options may be specified. 64.Pp 65.Ar Allowed_peer 66can be any of the following: 67.Bl -tag -width "ipaddr/masklen[:service]XX" 68.It Ar ipaddr/masklen Ns Op Ar :service 69Accept datagrams from 70.Ar ipaddr 71(in the usual dotted quad notation) with 72.Ar masklen 73bits being taken into account when doing the address comparision. If 74specified, 75.Ar service 76is the name or number of an UDP service (see 77.Xr services 5 ) Ns 78the source packet must belong to. A 79.Ar service 80of 81.Ql \&* 82allows packets being sent from any UDP port. The default 83.Ar service 84is 85.Ql syslog . 86A missing 87.Ar masklen 88will be substituted by the historic class A or class B netmasks if 89.Ar ipaddr 90belongs into the address range of class A or B, respectively, or 91by 24 otherwise. 92.It Ar domainname Ns Op Ar :service 93Accept datagrams where the reverse address lookup yields 94.Ar domainname 95for the sender address. The meaning of 96.Ar service 97is as explained above. 98.It Ar *domainname Ns Op Ar :service 99Same as before, except that any source host whose name 100.Em ends 101in 102.Ar domainname 103will get permission. 104.El 105.It Fl d 106Put 107.Nm 108into debugging mode. This is probably only of use to developers working on 109.Nm Ns . 110.It Fl f 111Specify the pathname of an alternate configuration file; 112the default is 113.Pa /etc/syslog.conf . 114.It Fl m 115Select the number of minutes between 116.Dq mark 117messages; the default is 20 minutes. 118.It Fl p 119Specify the pathname of an alternate log socket to be used instead; 120the default is 121.Pa /var/run/log . 122.It Fl l 123Specify a location where 124.Nm syslogd 125should place an additional log socket. 126Up to 19 additional logging sockets can be specified. 127The primary use for this is to place additional log sockets in 128.Pa /dev/log 129of various chroot filespaces. 130.It Fl s 131Operate in secure mode. Do not log messages from remote machines. If 132specified once, the messages will be received and counted and a log 133entry produced every time the count exceeds a power of two. If 134specified twice, no network socket will be opened at all. 135.It Fl u 136Unique priority logging. Only log messages at the specified priority. 137Without this option, messages at the stated priority or higher are logged. 138This option changes the default comparison from 139.Dq => 140to 141.Dq = . 142.It Fl v 143Verbose logging. If specified once, the numeric facility and priority are 144logged with each locally-written message. If specified more than once, 145the names of the facility and priority are logged with each locally-written 146message. 147.El 148.Pp 149The 150.Nm 151daemon reads its configuration file when it starts up and whenever it 152receives a hangup signal. 153For information on the format of the configuration file, 154see 155.Xr syslog.conf 5 . 156.Pp 157The 158.Nm 159daemon reads messages from the 160.Tn UNIX 161domain socket 162.Pa /var/run/log , 163from an Internet domain socket specified in 164.Pa /etc/services , 165and from the special device 166.Pa /dev/klog 167(to read kernel messages). 168.Pp 169The 170.Nm 171daemon creates the file 172.Pa /var/run/syslog.pid , 173and stores its process 174id there. 175This can be used to kill or reconfigure 176.Nm Ns . 177.Pp 178The message sent to 179.Nm 180should consist of a single line. 181The message can contain a priority code, which should be a preceding 182decimal number in angle braces, for example, 183.Sq Aq 5. 184This priority code should map into the priorities defined in the 185include file 186.Aq Pa sys/syslog.h . 187.Sh FILES 188.Bl -tag -width /var/run/syslog.pid -compact 189.It Pa /etc/syslog.conf 190configuration file 191.It Pa /var/run/syslog.pid 192process id of current 193.Nm 194.It Pa /var/run/log 195name of the 196.Tn UNIX 197domain datagram log socket 198.It Pa /dev/klog 199kernel log device 200.El 201.Sh SEE ALSO 202.Xr logger 1 , 203.Xr syslog 3 , 204.Xr services 5 , 205.Xr syslog.conf 5 206.Sh HISTORY 207The 208.Nm 209command appeared in 210.Bx 4.3 . 211.Pp 212The 213.Fl a , 214.Fl s , 215.Fl u , 216and 217.Fl v 218options are 219.Fx 2.2 220extensions. 221.Sh BUGS 222The ability to log messages received in UDP packets is equivalent to 223an unauthenticated remote disk-filling service, and should probably be 224disabled by default. Some sort of 225.No inter- Ns Nm syslogd 226authentication mechanism ought to be worked out. To prevent the worst 227abuse, use of the 228.Fl a 229option is therefore highly recommended. 230.Pp 231The 232.Fl a 233matching algorithm doesn't pretend to be very efficient; use of numeric 234IP addresses is faster than domain name comparision. Since the allowed 235peer list is being walked linearly, peer groups where frequent messages 236are being anticipated from should be put early into the 237.Fl a 238list. 239.Pp 240The log socket was moved from 241.Pa /dev 242to ease the use of a read-only root filesystem. This may confuse 243some old binaries so that a symbolic link might be used for a 244transitional period. 245