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.\" $FreeBSD$ 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 dknsuv 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. 54.Pp 55The options are as follows: 56.Bl -tag -width indent 57.It Fl a Ar allowed_peer 58Allow 59.Ar allowed_peer 60to log to this 61.Nm 62using UDP datagrams. Multiple 63.Fl a 64options may be specified. 65.Pp 66.Ar Allowed_peer 67can be any of the following: 68.Bl -tag -width "ipaddr/masklen[:service]XX" 69.It Ar ipaddr/masklen Ns Op Ar :service 70Accept datagrams from 71.Ar ipaddr 72(in the usual dotted quad notation) with 73.Ar masklen 74bits being taken into account when doing the address comparison. If 75specified, 76.Ar service 77is the name or number of an UDP service (see 78.Xr services 5 ) Ns 79the source packet must belong to. A 80.Ar service 81of 82.Ql \&* 83allows packets being sent from any UDP port. The default 84.Ar service 85is 86.Ql syslog . 87A missing 88.Ar masklen 89will be substituted by the historic class A or class B netmasks if 90.Ar ipaddr 91belongs into the address range of class A or B, respectively, or 92by 24 otherwise. 93.It Ar domainname Ns Op Ar :service 94Accept datagrams where the reverse address lookup yields 95.Ar domainname 96for the sender address. The meaning of 97.Ar service 98is as explained above. 99.It Ar *domainname Ns Op Ar :service 100Same as before, except that any source host whose name 101.Em ends 102in 103.Ar domainname 104will get permission. 105.El 106.It Fl d 107Put 108.Nm 109into debugging mode. This is probably only of use to developers working on 110.Nm Ns . 111.It Fl f 112Specify the pathname of an alternate configuration file; 113the default is 114.Pa /etc/syslog.conf . 115.It Fl k 116Disable the translation of 117messages received with facility 118.Dq kern 119to facility 120.Dq user . 121Usually the 122.Dq kern 123facility is reserved for messages read directly from 124.Pa /dev/klog . 125.It Fl m 126Select the number of minutes between 127.Dq mark 128messages; the default is 20 minutes. 129.It Fl n 130Disable dns query for every request. 131.It Fl p 132Specify the pathname of an alternate log socket to be used instead; 133the default is 134.Pa /var/run/log . 135.It Fl l 136Specify a location where 137.Nm 138should place an additional log socket. 139Up to 19 additional logging sockets can be specified. 140The primary use for this is to place additional log sockets in 141.Pa /var/run/log 142of various chroot filespaces. 143.It Fl s 144Operate in secure mode. Do not log messages from remote machines. If 145specified twice, no network socket will be opened at all, which also 146disables logging to remote machines. 147.It Fl u 148Unique priority logging. Only log messages at the specified priority. 149Without this option, messages at the stated priority or higher are logged. 150This option changes the default comparison from 151.Dq => 152to 153.Dq = . 154.It Fl v 155Verbose logging. If specified once, the numeric facility and priority are 156logged with each locally-written message. If specified more than once, 157the names of the facility and priority are logged with each locally-written 158message. 159.El 160.Pp 161The 162.Nm 163daemon reads its configuration file when it starts up and whenever it 164receives a hangup signal. 165For information on the format of the configuration file, 166see 167.Xr syslog.conf 5 . 168.Pp 169The 170.Nm 171daemon reads messages from the 172.Tn UNIX 173domain socket 174.Pa /var/run/log , 175from an Internet domain socket specified in 176.Pa /etc/services , 177and from the special device 178.Pa /dev/klog 179(to read kernel messages). 180.Pp 181The 182.Nm 183daemon creates the file 184.Pa /var/run/syslog.pid , 185and stores its process 186id there. 187This can be used to kill or reconfigure 188.Nm Ns . 189.Pp 190The message sent to 191.Nm 192should consist of a single line. 193The message can contain a priority code, which should be a preceding 194decimal number in angle braces, for example, 195.Sq Aq 5. 196This priority code should map into the priorities defined in the 197include file 198.Aq Pa sys/syslog.h . 199.Sh FILES 200.Bl -tag -width /var/run/syslog.pid -compact 201.It Pa /etc/syslog.conf 202configuration file 203.It Pa /var/run/syslog.pid 204process id of current 205.Nm 206.It Pa /var/run/log 207name of the 208.Tn UNIX 209domain datagram log socket 210.It Pa /dev/klog 211kernel log device 212.El 213.Sh SEE ALSO 214.Xr logger 1 , 215.Xr syslog 3 , 216.Xr services 5 , 217.Xr syslog.conf 5 218.Sh HISTORY 219The 220.Nm 221command appeared in 222.Bx 4.3 . 223.Pp 224The 225.Fl a , 226.Fl s , 227.Fl u , 228and 229.Fl v 230options are 231.Fx 2.2 232extensions. 233.Sh BUGS 234The ability to log messages received in UDP packets is equivalent to 235an unauthenticated remote disk-filling service, and should probably be 236disabled by default. Some sort of 237.No inter- Ns Nm syslogd 238authentication mechanism ought to be worked out. To prevent the worst 239abuse, use of the 240.Fl a 241option is therefore highly recommended. 242.Pp 243The 244.Fl a 245matching algorithm doesn't pretend to be very efficient; use of numeric 246IP addresses is faster than domain name comparison. Since the allowed 247peer list is being walked linearly, peer groups where frequent messages 248are being anticipated from should be put early into the 249.Fl a 250list. 251.Pp 252The log socket was moved from 253.Pa /dev 254to ease the use of a read-only root filesystem. 255This may confuse 256some old binaries so that a symbolic link might be used for a 257transitional period. 258