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28 .\" @(#)sliplogin.8 8.2 (Berkeley) 1/5/94
36 .Nd attach a serial line network interface
39 .Op Ar loginname Op Ar device
43 utility is used to turn the terminal line on standard input (or
47 link to a remote host.
48 To do this, the program
50 .Pa /etc/sliphome/slip.hosts
53 (which defaults to the current login name if omitted).
54 If a matching entry is found, the line is configured appropriately
55 for slip (8-bit transparent i/o) and converted to
57 line discipline using the optional line discipline parameters.
59 The optional line discipline parameters consist of one or more of
66 which correspond respectively to
67 .Sq use normal line discipline
68 (no header compression),
69 .Sq enable VJ header compression ,
70 .Sq throw away ICMP packets ,
72 .Sq auto enable VJ header compression
73 (only if the remote end of the link also supports it).
75 Then a shell script is invoked to initialize the slip
76 interface with the appropriate local and remote
81 The usual initialization script is
82 .Pa /etc/sliphome/slip.login
83 but, if particular hosts need special initialization, the file
84 .Pa /etc/sliphome/slip.login. Ns Ar loginname
85 will be executed instead if it exists.
86 The script is invoked with the parameters
87 .Bl -tag -width slipunit
89 The unit number of the slip interface assigned to this line.
95 The speed of the line.
97 The arguments from the
98 .Pa /etc/sliphome/slip.hosts
99 entry, in order starting with
103 Only the super-user may attach a network interface.
105 automatically detached when the other end hangs up or the
109 module has been configured for it, all routes through that interface will
110 also disappear at the same time.
111 If there is other processing a site
112 would like done on hangup, the file
113 .Pa /etc/sliphome/slip.logout
115 .Pa /etc/sliphome/slip.logout. Ns Ar loginname
116 is executed if it exists.
117 It is given the same arguments as the login script.
118 .Ss Format of /etc/sliphome/slip.hosts
119 Comments (lines starting with a `#') and blank lines (or started
120 with space) are ignored.
121 Other lines must start with a
123 but the remaining arguments can be whatever is appropriate for the
125 file that will be executed for that name.
126 Arguments are separated by white space and follow normal
128 quoting conventions (however,
131 Usually, lines have the form
132 .Bd -literal -offset indent
133 loginname local-address remote-address netmask opt-args
140 are the IP host names or addresses of the local and remote ends of the
143 is the appropriate IP netmask.
144 These arguments are passed
148 are optional arguments used to configure the line.
149 .Sh FreeBSD Additions
150 An additional SLIP configuration file (if present) is
151 .Pa /etc/sliphome/slip.slparms .
152 If particular hosts need different configurations, the file
153 .Pa /etc/sliphome/slip.slparms. Ns Ar loginname
154 will be parsed instead if it exists.
155 .Ss Format of /etc/sliphome/slip.slparms*
156 Comments (lines starting with a `#') and blank lines (or started with
158 This file contains from one to three numeric parameters separated with spaces,
164 .Bl -tag -width keepalive
166 Set SLIP "keep alive" timeout in seconds.
167 If FRAME_END is not received in
170 closes the line and exits.
171 The default value is no timeout (zero).
173 Set SLIP "out fill" timeout in seconds.
174 It forces at least one FRAME_END
175 to be sent during this time period, which is necessary for the "keep alive"
176 timeout on the remote side.
177 The default value is no timeout (zero).
179 Set the SLIP unit number directly.
180 Use with caution, because no check is made
181 for two interfaces with same number.
182 By default sliplogin dynamically assigns the unit number.
185 If latter two parameters are omitted, they will not affect the
186 corresponding SLIP configuration.
187 If any of first two parameters is equal to zero, it will not affect
188 the corresponding SLIP configuration.
190 .Bl -tag -width indent
191 .It Pa /etc/sliphome/slip.hosts
192 list of host login names and parameters.
193 .It Pa /etc/sliphome/slip.login
194 script executed when a connection is made.
195 .It Pa /etc/sliphome/slip.login. Ns Ar loginname
196 script executed when a connection is made by
198 .It Pa /etc/sliphome/slip.logout
199 script executed when a connection is lost.
200 .It Pa /etc/sliphome/slip.logout. Ns Ar loginname
201 script executed when a connection is lost by
203 .It Pa /etc/sliphome/slip.slparms
204 extra parameters file.
205 .It Pa /etc/sliphome/slip.slparms. Ns Ar loginname
206 extra parameters file for
208 .It Pa /var/run/ Ns Ar ttyXn Ns Pa .if
209 contains the name of the network interface used by the sliplogin process on
211 .It Pa /var/run/ Ns Ar slX Ns Pa .pid
212 contains the PID of the sliplogin process which is using interface
220 entry for each legal, remote slip site with
222 as the shell for that entry.
225 Sfoo:ikhuy6:2010:1:slip line to foo:/tmp:/usr/sbin/sliplogin
228 (Our convention is to name the account used by remote host
232 Then an entry is added to
236 .Bd -literal -offset indent -compact
237 Sfoo `hostname` foo netmask
244 to the local host name and
246 is the local host IP netmask.
250 must be setuid to root and, while not a security hole, moral defectives
251 can use it to place terminal lines in an unusable state and/or deny
252 access to legitimate users of a remote slip line.
259 and mode 4550 so that only members of group
263 The system administrator should make sure that all legitimate users
264 are a member of the correct group.
268 utility logs various information to the system log daemon,
270 with a facility code of
272 The messages are listed here, grouped by severity level.
275 .Bl -tag -width Ds -compact
276 .It Sy ioctl (TCGETS): Em reason
280 to get the line parameters failed.
282 .It Sy ioctl (TCSETS): Em reason
286 to set the line parameters failed.
288 .It Sy /etc/sliphome/slip.hosts: Em reason
290 .Pa /etc/sliphome/slip.hosts
291 file could not be opened.
293 .It Sy access denied for Em user
297 .Pa /etc/sliphome/slip.hosts .
301 .Bl -tag -width Ds -compact
302 .It Sy "attaching slip unit" Em unit Sy for Ar loginname
306 was successfully attached.
312 .Pa /usr/share/examples/sliplogin