1.\" Copyright (c) 1986, 1991 The Regents of the University of California. 2.\" 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.\" @(#)slattach.8 6.4 (Berkeley) 3/16/91 33.\" 34.\" $FreeBSD: src/sbin/slattach/slattach.8,v 1.16.2.6 2003/02/23 21:17:43 trhodes Exp $ 35.\" $DragonFly: src/sbin/slattach/slattach.8,v 1.2 2003/06/17 04:27:34 dillon Exp $ 36.\" 37.Dd April 4, 1993 38.Dt SLATTACH 8 39.Os 40.Sh NAME 41.Nm slattach 42.Nd attach serial lines as network interfaces 43.Sh SYNOPSIS 44.Nm 45.Op Fl a 46.Op Fl c 47.Op Fl e Ar exit-command 48.Op Fl f 49.Op Fl h 50.Op Fl l 51.Op Fl n 52.Op Fl z 53.Op Fl L 54.Op Fl r Ar redial-command 55.Op Fl s Ar baudrate 56.Op Fl u Ar unit-command 57.Op Fl K Ar keepalive 58.Op Fl O Ar outfill 59.Op Fl S Ar unit 60.Ar ttyname 61.Sh DESCRIPTION 62The 63.Nm 64utility is used to assign a tty line to a network interface, 65and to define the network source and destination addresses. 66.Pp 67The following options are available: 68.Bl -tag -width indent 69.It Fl a 70Autoenable the VJ header compression option, if the other end of the link 71is capable of VJ header compression then it will be used otherwise normal 72headers will be used. 73.It Fl c 74Enable the VJ header compression option. Note that both ends of the link 75must be able to use VJ header compression for this to work. 76.It Fl e Ar exit-command 77Specify a command to be invoked within a shell 78.Ql sh \-c Ar exit-command 79before 80.Nm 81exits. 82.It Fl f 83Disable the invocation of daemon() to run 84.Nm 85in the background. 86.It Fl h 87Turn on cts/rts style flow control on the slip port, by default no flow 88control is done. 89.It Fl l 90Disable modem control (CLOCAL) and ignore carrier detect on the slip 91port. By default the 92.Ar redial-command 93is invoked upon carrier drop and 94.Nm 95aborts if no 96.Ar redial-command 97is specified. 98.It Fl n 99Throw away ICMP packets. The slip interface will ignore ICMP packets 100to prevent slow lines being saturated by ICMP responses. 101.It Fl r Ar redial-command 102Specify a command to be invoked within a shell 103.Ql sh \-c Ar redial-command 104whenever carrier is lost on the modem line. 105Empty 106.Ar redial-command 107(i.e.\& 108.Fl r Qq "" ) 109cause connection reestablishing on leased line 110without any external command invoked. 111.It Fl s Ar baudrate 112Specify the speed of the connection. 113If not specified, the 114default of 9600 is used. 115.It Fl u Ar unit-command 116When the line is switched to slip discipline, run 117.Dq Nm "sh -c" Ar unit-command old new 118where 119.Ar old 120and 121.Ar new 122are the slip unit numbers when the line was 123last opened and the unit number of the current slip connection 124respectively. The unit number can change after redialing if you are 125using more than one slip line. 126When 127.Nm 128is connected for the first time, 129.Dq Nm "sh -c" Ar unit-command \-1 new 130is run. 131When 132.Nm 133is disconnected, 134.Dq Nm "sh -c" Ar unit-command old \-1 135is run. 136The 137.Nm 138utility will abort if the unit number 139changes and 140.Dq Fl u Ar \%unit-command 141was not specified. 142.It Fl z 143Force redial 144.Ar redial-command 145upon startup irrespective of carrier. 146.It Fl L 147Use uucp-style device locking. 148You need it unless you start 149.Nm 150from external program which already does uucp locking. 151Default case is no uucp locking to satisfy such programs. 152.It Fl K Ar keepalive 153Set SLIP "keep alive" timeout in seconds. 154If FRAME_END is not received in 155this amount of time, re-connect occurs. 156The default value is no timeout. 157.It Fl O Ar outfill 158Set SLIP "out fill" timeout in seconds. It forces at least one FRAME_END 159to be sent during this time period, which is necessary for the "keep alive" 160timeout on the remote side. 161The default value is no timeout. 162.It Fl S Ar unit 163Set the SLIP unit number directly. 164Use with caution, because no check is made 165for two interfaces with same number. 166By default sliplogin dynamically assigns the unit number. 167.It Ar ttyname 168Specify the name of the tty device. 169.Ar Ttyname 170should be a string of the form 171.Ql ttyXX 172or 173.Ql /dev/ttyXX . 174.El 175.Pp 176Only the super-user may attach a network interface. 177.Pp 178To detach the interface, use 179.Dq Li ifconfig interface-name down 180after killing off the 181.Nm 182process using 183.Ql kill -INT . 184.Ar Interface-name 185is the name that is shown by 186.Xr netstat 1 . 187.Pp 188To setup 189.Nm 190to redial the phone when carrier is lost, use the 191.Fl r Ar redial-command 192option to specify a script or executable that will reconnect the 193serial line to the slip server. For example, the script could redial 194the server and log in, etc. 195.Pp 196To reconfigure the network interface in case the slip unit number 197changes, use the 198.Fl u Ar unit-command 199option to specify a script or executable that will be invoked as 200.Ql sh \-c Ar unit-command old new 201where 202.Ar old 203and 204.Ar new 205are the slip unit numbers before and after 206reconnecting the line. The unit number can change if you have more 207than one line disconnect at the same time. The first to succeed in 208reconnecting will get the lowest unit number. 209.Pp 210To kill 211.Nm 212use 213.Ql kill -INT 214(SIGINT) which causes it to close the tty and exit. 215.Pp 216To force a redial, use 217.Ql kill -HUP 218(SIGHUP) which causes 219.Nm 220to think carrier was lost and thus invoke 221.Ql sh \-c Ar redial-command 222to reconnect to the server. 223.Pp 224If you use a hard-wired connection rather than a modem, invoke 225.Nm 226with the 227.Fl l 228option in order to ignore carrier on the slip line. 229.Sh EXAMPLES 230.Bd -literal -offset indent -compact 231slattach ttyd8 232slattach \-s 4800 /dev/ttyd1 233slattach \-c \-s 38400 /dev/cuaa1 234slattach \-r 'kermit -y dial.script >kermit.log 2>&1' 235.Ed 236.Sh DIAGNOSTICS 237Look for error messages in 238.Pa /var/log/messages 239.No ( Nm 240is a daemon). 241Messages indicating the specified interface does not exit, the 242requested address is unknown, the user is not privileged and tried to 243alter an interface's configuration are logged there. 244The 245.Nm 246utility 247also logs failure to set the controlling terminal or failure to install 248signal handlers. Upon connection and redial the ttyname and baud rate 249are logged and on shutdown the ttyname is logged. 250.Sh FILES 251.Bl -tag -width /usr/share/examples/slattach/* -compact 252.It Pa /var/run/slattach.<tty>.pid 253with 254.Ar tty 255replaced by the terminal path name component of 256.Ar ttyname . 257This file contains the numerical process ID of the 258.Nm 259process and can be examined by scripts in order to send a signal to 260.Nm 261.It Pa /usr/share/examples/slattach/* 262.El 263.Sh SEE ALSO 264.Xr netstat 1 , 265.Xr startslip 1 , 266.Xr uustat 1 , 267.Xr netintro 4 , 268.Xr ifconfig 8 , 269.Xr rc 8 , 270.Xr sliplogin 8 271.Sh HISTORY 272The 273.Nm 274utility appeared in 275.Bx 4.3 . 276