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Diffstat (limited to 'usr.sbin/rwhod/rwhod.8')
| -rw-r--r-- | usr.sbin/rwhod/rwhod.8 | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/usr.sbin/rwhod/rwhod.8 b/usr.sbin/rwhod/rwhod.8 new file mode 100644 index 0000000..4b8492e --- /dev/null +++ b/usr.sbin/rwhod/rwhod.8 @@ -0,0 +1,146 @@ +.\" Copyright (c) 1983, 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)rwhod.8 8.2 (Berkeley) 12/11/93 +.\" +.Dd December 11, 1993 +.Dt RWHOD 8 +.Os BSD 4.2 +.Sh NAME +.Nm rwhod +.Nd system status server +.Sh SYNOPSIS +.Nm rwhod +.Sh DESCRIPTION +.Nm Rwhod +is the server which maintains the database used by the +.Xr rwho 1 +and +.Xr ruptime 1 +programs. Its operation is predicated on the ability to +.Em broadcast +messages on a network. +.Pp +.Nm Rwhod +operates as both a producer and consumer of status information. +As a producer of information it periodically +queries the state of the system and constructs +status messages which are broadcast on a network. +As a consumer of information, it listens for other +.Nm rwhod +servers' status messages, validating them, then recording +them in a collection of files located in the directory +.Pa /var/rwho . +.Pp +The server transmits and receives messages at the port indicated +in the ``rwho'' service specification; see +.Xr services 5 . +The messages sent and received, are of the form: +.Bd -literal -offset indent +struct outmp { + char out_line[8]; /* tty name */ + char out_name[8]; /* user id */ + long out_time; /* time on */ +}; + +struct whod { + char wd_vers; + char wd_type; + char wd_fill[2]; + int wd_sendtime; + int wd_recvtime; + char wd_hostname[32]; + int wd_loadav[3]; + int wd_boottime; + struct whoent { + struct outmp we_utmp; + int we_idle; + } wd_we[1024 / sizeof (struct whoent)]; +}; +.Ed +.Pp +All fields are converted to network byte order prior to +transmission. The load averages are as calculated by the +.Xr w 1 +program, and represent load averages over the 5, 10, and 15 minute +intervals prior to a server's transmission; they are multiplied by 100 +for representation in an integer. The host name +included is that returned by the +.Xr gethostname 2 +system call, with any trailing domain name omitted. +The array at the end of the message contains information about +the users logged in to the sending machine. This information +includes the contents of the +.Xr utmp 5 +entry for each non-idle terminal line and a value indicating the +time in seconds since a character was last received on the terminal line. +.Pp +Messages received by the +.Xr rwho +server are discarded unless they originated at an +.Xr rwho +server's port. In addition, if the host's name, as specified +in the message, contains any unprintable +.Tn ASCII +characters, the +message is discarded. Valid messages received by +.Nm rwhod +are placed in files named +.Pa whod.hostname +in the directory +.Pa /var/rwho . +These files contain only the most recent message, in the +format described above. +.Pp +Status messages are generated approximately once every +3 minutes. +.Nm Rwhod +performs an +.Xr nlist 3 +on +.Pa /vmunix +every 30 minutes to guard against +the possibility that this file is not the system +image currently operating. +.Sh SEE ALSO +.Xr rwho 1 , +.Xr ruptime 1 +.Sh BUGS +There should be a way to relay status information between networks. +Status information should be sent only upon request rather than continuously. +People often interpret the server dying +or network communication failures +as a machine going down. +.Sh HISTORY +The +.Nm +command appeared in +.Bx 4.2 . |
