This example explains how to create a web-page for the package httptunnel.
Usages information:
# hts --help
Usage: hts [OPTION]... [PORT]
Listen for incoming httptunnel connections at PORT (default port is 8888).
When a connection is made, I/O is redirected to the destination specified
by the --device, --forward-port or --stdin-stdout switch.
-c, --content-length BYTES use HTTP PUT requests of BYTES size
(k, M, and G postfixes recognized)
-d, --device DEVICE use DEVICE for input and output
-F, --forward-port HOST:PORT connect to PORT at HOST and use it for
input and output
-h, --help display this help and exit
-k, --keep-alive SECONDS send keepalive bytes every SECONDS seconds
(default is 5)
-M, --max-connection-age SEC maximum time a connection will stay
open is SEC seconds (default is 300)
-s, --stdin-stdout use stdin/stdout for communication
(implies --no-daemon)
-S, --strict-content-length always write Content-Length bytes in requests
-V, --version output version information and exit
-w, --no-daemon don't fork into the background
-p, --pid-file LOCATION write a PID file to LOCATION
Report bugs to bug-httptunnel@gnu.org.
#
First some characteristics of the HTTPTunnel package.
Based on the usage information we can select the following variables for
inclusion in the web-interface:
-F <HOST>:<HOSTPORT>
-k <KEEPALIVE>
-M <MAXCONNECTIONAGE>
-d <DEVICE>
<CLIENTPORT>\
Next we need to create the <package>.cfg file with the default values. We always need the <PACKAGE>_ENABLED variable with default value ‘no’. For HOST I selected ‘localhost’, but I actually never used this package, so I’m not sure if this default value is good from a security point of view.
export HTTPTUNNEL_ENABLED='no'
export HTTPTUNNEL_HOST='localhost'
export HTTPTUNNEL_HOSTPORT='22'
export HTTPTUNNEL_CLIENTPORT='443'
export HTTPTUNNEL_KEEPALIVE='5'
export HTTPTUNNEL_MAXCONNECTIONAGE='300'
export HTTPTUNNEL_DEVICE=''
Now the <package>.cgi can be
created.
The first part is Start Type and is enclosed with the sec_begin and
sec_end keywords.
This part is uses the HTTPTUNNEL_ENABLED variable, and determines if
the package should be started automatically at system startup.
Two input
elements with
radio buttons are declared within a
paragraph.
On the actual web-page the first item is Status, displaying the
current status of the package and a Start, Stop and Restart button. This
part is probably generated by /usr/lib/libmodcgi.sh.
For each displayed text you see a lang statement and the text in both
German and the English language. This lang statement is used during
build on the build environment.
To be able to test your created
<package>.cgi file directly on the
router you can first create one without the lang statements, using
just your preferred language.
After the web-interface behaves as required you can add the lang
statements and the text in both languages.
See page <package>.cgi for more
information on the lang statement.
The second part, enclosed with the sec_begin and sec_end keywords,
is for configuring the selected parameters.
In this case a
table
is used with a table row (tr) for each parameter, and a column for to
display the parameter name, and a column for entering the value in an
input field.
A table has the advantage that the cells in the columns are
automatically aligned.
In the first table data cell (td) the displays the parameter name in the
correct language. The second table data cell (td) displays the current
value using the Shell instruction html "$HTTPTUNNEL_<VALUE>" as
value,
in the input field of
size
characters length displayed, and a maximum of
maxlength
characters that can be entered.
The entered value is assigned to the input-field element
name
like name=’<value>’, which correspond to the parameter name
<PACKAGE><VALUE>.
The input
type
is here always text.
After selecting the Apply button the entered values are assigned to the
<PACKAGE><VALUE> parameters located in
/mod/etc/conf/<package>.cfg.
httptunnel.cgi without lang statements:
#!/bin/sh
. /usr/lib/libmodcgi.sh
check "$HTTPTUNNEL_ENABLED" yes:auto "*":man
sec_begin 'Start type'
cat << EOF
<p>
<input id="e1" type="radio" name="enabled" value="yes"$auto_chk><label for="e1">Automatic</label>
<input id="e2" type="radio" name="enabled" value="no"$man_chk><label for="e2">Manual</label>
EOF
cat << EOF
</p>
EOF
sec_end
sec_begin 'httptunnel'
cat << EOF
<table border="0">
<tr>
<td>Destination Host:</td>
<td><input type="text" name="host" size="60" maxlength="255" value="$(html "$HTTPTUNNEL_HOST")"></td>
</tr>
<tr>
<td>Destination Port:</td>
<td><input type="text" name="hostport" size="5" maxlength="5" value="$(html "$HTTPTUNNEL_HOSTPORT")"></td>
</tr>
<tr>
<td>Client Port:</td>
<td><input type="text" name="clientport" size="5" maxlength="5" value="$(html "$HTTPTUNNEL_CLIENTPORT")"></td>
</tr>
<tr>
<td>Keep Alive:</td>
<td><input type="text" name="keepalive" size="3" maxlength="3" value="$(html "$HTTPTUNNEL_KEEPALIVE")"></td>
</tr>
<tr>
<td>Max Connection Age:</td>
<td><input type="text" name="maxconnectionage" size="4" maxlength="4" value="$(html "$HTTPTUNNEL_MAXCONNECTIONAGE")"></td>
</tr>
<tr>
<td>Device:</td>
<td><input type="text" name="device" size="10" maxlength="10" value="$(html "$HTTPTUNNEL_DEVICE")"></td>
</tr>
</table>
EOF
sec_end
httptunnel.cgi with lang statements and an entry for each language:
#!/bin/sh
. /usr/lib/libmodcgi.sh
check "$HTTPTUNNEL_ENABLED" yes:auto "*":man
sec_begin '$(lang de:"Starttyp" en:"Start type")'
cat << EOF
<p>
<input id="e1" type="radio" name="enabled" value="yes"$auto_chk><label for="e1">$(lang de:"Automatisch" en:"Automatic")</label>
<input id="e2" type="radio" name="enabled" value="no"$man_chk><label for="e2">$(lang de:"Manuell" en:"Manual")</label>
EOF
cat << EOF
</p>
EOF
sec_end
sec_begin '$(lang de:"httptunnel" en:"httptunnel")'
cat << EOF
<table border="0">
<tr>
<td>$(lang de:"Destination Host" en:"Destination Host"):</td>
<td><input type="text" name="host" size="80" maxlength="255" value="$(html "$HTTPTUNNEL_HOST")"></td>
</tr>
<tr>
<td>$(lang de:"Destination Port" en:"Destination Port"):</td>
<td><input type="text" name="hostport" size="5" maxlength="5" value="$(html "$HTTPTUNNEL_HOSTPORT")"></td>
</tr>
<tr>
<td>$(lang de:"Client Port" en:"Client Port"):</td>
<td><input type="text" name="clientport" size="5" maxlength="5" value="$(html "$HTTPTUNNEL_CLIENTPORT")"></td>
</tr>
<tr>
<td>$(lang de:"Keep Alive" en:"Keep Alive"):</td>
<td><input type="text" name="keepalive" size="3" maxlength="3" value="$(html "$HTTPTUNNEL_KEEPALIVE")"></td>
</tr>
<tr>
<td>$(lang de:"Max Connection Age" en:"Max Connection Age"):</td>
<td><input type="text" name="maxconnectionage" size="4" maxlength="4" value="$(html "$HTTPTUNNEL_MAXCONNECTIONAGE")"></td>
</tr>
<tr>
<td>$(lang de:"Device" en:"Device"):</td>
<td><input type="text" name="device" size="10" maxlength="10" value="$(html "$HTTPTUNNEL_DEVICE")"></td>
</tr>
</table>
EOF
sec_end
Now we only need to write the
rc.<package> file.
For this package the package name httptunnel and the binary hts
differ. This requires the use of variable DAEMON for the package name,
and DAEMON_BIN for the binary.
From the usage information we get that the binary gives an option to
specify the PID-file. We will use this option in the rc.httptunnel
file.
The binary is executed with the modlib_startdaemon function, which is
using in the start () function. As parameter the DAEMON_BIN with its
parameters is used.
For this package we have one conditional parameter. The DEVICE option
should only be added to the list of parameters is it contains a non-zero
amount of characters.
This is accomplished using a if [ test ] then function.
The case function test for a match. See the
rc.<package> page for more
information.
#!/bin/sh
DAEMON=httptunnel
DAEMON_BIN=hts
PID_FILE=/var/run/$DAEMON_BIN.pid
. /etc/init.d/modlibrc
start() {
OPTIONS="-F $HTTPTUNNEL_HOST:$HTTPTUNNEL_HOSTPORT \
-k $HTTPTUNNEL_KEEPALIVE \
-M $HTTPTUNNEL_MAXCONNECTIONAGE \
-p $PID_FILE \
$HTTPTUNNEL_CLIENTPORT"
[ -n "$HTTPTUNNEL_DEVICE" ] && OPTIONS="$OPTIONS -d $HTTPTUNNEL_DEVICE"
modlib_startdaemon $DAEMON_BIN $OPTIONS
}
case $1 in
""|load)
modreg cgi 'httptunnel' 'httptunnel'
modreg daemon httptunnel
modlib_start $HTTPTUNNEL_ENABLED
;;
unload)
modunreg daemon httptunnel
modunreg cgi 'httptunnel'
modlib_stop
;;
start)
modlib_start
;;
stop)
modlib_stop
;;
restart)
modlib_restart
;;
status)
modlib_status
;;
*)
echo "Usage: $0 [load|unload|start|stop|restart|status]" 1>&2
exit 1
;;
esac
exit 0
The following scripts can help to test the created files directly on the
router.
For this the files are located on a USB-stick.
If the web-interface is working you can add the parameter 2 to obtain
the config parameter values from tffs.
For the initial development of all files:
#!/bin/sh
export package=httptunnel
echo Will add webinterface for $package
[ ! -e /mod/etc/default.$package ] && mkdir /mod/etc/default.$package
[ ! -e /mod/etc/default.$package/$package.cfg ] && cp $package.cfg /mod/etc/default.$package/
if [ $1 -eq 2 ]; then
modconf load $package
else
[ ! -e /mod/etc/conf/$package.cfg ] && cp $package.cfg /mod/etc/conf/
fi
cd /var/mod/usr/lib/cgi-bin/
[ ! -e /var/mod/usr/lib/cgi-bin/$package.cgi ] && ln -s /var/media/ftp/uStor01/freetz/webinterface/$package/$package.cgi $package.cgi
cd /mod/etc/init.d/
[ ! -e /mod/etc/init.d/rc.$package ] && ln -s /var/media/ftp/uStor01/freetz/webinterface/$package/rc.$package rc.$package
rm /var/mod/var/cache/menu/packages
modreg cgi $package $package
For verifying changes to just the rc.<package> file e.g. after already including the files in the Freetz image:
#!/bin/sh
export package=httptunnel
cd /mod/etc/init.d/
[ -h /mod/etc/init.d/rc.$package ] && rm /mod/etc/init.d/rc.$package
[ ! -e /mod/etc/init.d/rc.$package ] && ln -s /var/media/ftp/uStor01/freetz/webinterface/$package/rc.$package rc.$package
To help with Bash Shell scripts: