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martinoc
n00b
Joined: 12 Jan 2005
Posts: 12
Location: Ireland
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 Posted: Tue Jan 25, 2005 6:42 am Post subject: Wireless SSID and key configuration script |
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| Code: | #!/sbin/runscript
#NB: Config is in /etc/conf.d/ssid
depend() {
before net
}
checkconfig() {
if [ -z $IFACES ]; then
eerror "You need to setup IFACE /etc/conf.d/ssid first"
return 1
fi
}
start() {
checkconfig || return 1
ebegin "Setting ssids"
for iface in $IFACES; do
available=`iwlist scanning 2>&1 | grep ESSID | sed "s/ *//"| sed "s/ESSID:\"//" | sed "s/\"//"`
eval SSIDS=( \$${iface}_SSIDS )
if [ -z $SSIDS ]; then
ssid="any"
key="off"
eend 1 "${iface}_SSIDS not set in /etc/conf.d/ssid"
else
for ssid in $SSIDS; do
for avail in $available; do
if [ $avail = $ssid ]; then
eval key=( \$${iface}_${ssid} )
if [ -z $key ]; then
eend 1 "${iface}_$ssid not set in /etc/conf.d/ssid"
key="off"
ssid="any"
fi
break 2
fi
done
eend 0 "No configured ssids available for $iface"
ssid="any"
key="off"
done
fi
ebegin "Setting ssid to $ssid on $iface"
iwconfig $iface essid "$ssid"
iwconfig $iface key $key
done
eend 0
}
stop() {
checkconfig || return 1
for iface in $IFACES; do
ebegin "Unsetting ssids"
ebegin "Unsetting ssid on $iface"
iwconfig $iface essid any
iwconfig $iface key off
done
eend 0
}
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This requires the following variables configures in /etc/init.d/ssid
IFACES -> a list of interfaces to individually set up
<iface>_SSIDS -> a list of SSIDS in preferential order to set up for <iface>
<iface>_<ssid> -> the parameter to | Code: | | iwconfig $iface key |
for the combination of <iface> and <ssid>
The script will configure the first available ssid in the preferential list for each interface as obtained from iwlist scanning. |
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UberLord
Retired Dev
Joined: 18 Sep 2003
Posts: 6835
Location: Blighty
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| Posted: Tue Jan 25, 2005 9:55 am Post subject: |
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Nice script - just a few pointers though ....
[*] Why can't you detect if an interface is wireless and configure it automatically?
[*] What happens if the ESSID cotains any of the following characters "\/'-
[*] What about AP's that don't broadcast the ESSID?
| Code: | | available=`iwlist scanning 2>&1 | grep ESSID | sed "s/ *//"| sed "s/ESSID:\"//" | sed "s/\"//"` |
Yoiks! That's 3 chained sed statements with a grep! Here's a better one (which also fixes a bug for you)
| Code: | | available=$( iwlist ${iface} scanning 2>&1 | sed -ne 's/^ *ESSID:"\(.*\)"$/\1/p' ) |
Aside from all that, we already have wireless support in baselayout-1.11.8  |
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martinoc
n00b
Joined: 12 Jan 2005
Posts: 12
Location: Ireland
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| Posted: Tue Jan 25, 2005 10:25 am Post subject: |
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Not bad for my first attempt
here is an update
| Code: | #!/sbin/runscript
#NB: Config is in /etc/conf.d/ssid
depend() {
before net
}
checkconfig() {
if [ -z $IFACES ]; then
eerror "You need to setup IFACE /etc/conf.d/ssid first"
return 1
fi
}
start() {
checkconfig || return 1
ebegin "Setting ssids"
for iface in $IFACES; do
available=$( iwlist ${iface} scanning 2>&1 | sed -ne 's/^ *ESSID:"\(.*\)"$/\1/p' )
eval SSIDS=( \$${iface}_SSIDS )
if [ -z $SSIDS ]; then
ssid="any"
key="off"
eerror "${iface}_SSIDS not set in /etc/conf.d/ssid"
else
for ssid in $SSIDS; do
for avail in $available; do
if [ $avail = $ssid ]; then
eval key=( \$${iface}_${ssid} )
if [ -z $key ]; then
eerror "${iface}_$ssid not set in /etc/conf.d/ssid"
key="off"
ssid="any"
fi
break 2
fi
done
ewarn "No configured ssids available for $iface"
ssid="any"
key="off"
done
fi
einfo "Setting ssid to $ssid on $iface"
iwconfig $iface essid "$ssid"
iwconfig $iface key $key
done
eend 0
}
stop() {
checkconfig || return 1
for iface in $IFACES; do
ebegin "Unsetting ssids"
einfo "Unsetting ssid on $iface"
iwconfig $iface essid any
iwconfig $iface key off
done
eend 0
}
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can you explain the portion of the sed command after ESSID:
the rest i can understand.
answers to your questions
1) automatic config - i dont because the user has more control over the interfaces configured and not configured, and control over which ssids get assigned
2) - didn't see that one - hadn't had much sleep lately i guess ---> I guess this was the bug your replacement available= fixed
3) - I suppose I could select the most preferable (first) on the list instead of going to any and off |
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UberLord
Retired Dev
Joined: 18 Sep 2003
Posts: 6835
Location: Blighty
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| Posted: Tue Jan 25, 2005 11:19 am Post subject: |
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| martinoc wrote: |
can you explain the portion of the sed command after ESSID:
the rest i can understand.
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Sure!
\( \) means "define a group"
. means "match anything"
* means "match any amount of the precedding match"
So what we are saying is "from the start of the line match any amount of spaces followed by ESSID:". Then define group 1 which is anything upto the last " on the line.
The \1/p means print group 1
http://dev.gentoo.org/~ciaranm/docs/IGNORE_the-doc/#content-manipulation-sed
may be of some help
| Quote: |
answers to your questions
1) automatic config - i dont because the user has more control over the interfaces configured and not configured, and control over which ssids get assigned |
I have a laptop and 2 pccards - one wired and the other wireless. I can only have one inserted at any time, and both report themselves as eth0. How do you handle this?
| Quote: |
3) - I suppose I could select the most preferable (first) on the list instead of going to any and off |
What if you had 2 AP's that didn't broadcast? |
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martinoc
n00b
Joined: 12 Jan 2005
Posts: 12
Location: Ireland
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| Posted: Tue Jan 25, 2005 1:43 pm Post subject: |
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| Code: | #!/sbin/runscript
#NB: Config is in /etc/conf.d/ssid
depend() {
before net
}
checkconfig() {
if [ -z $IFACES ]; then
eerror "You need to setup IFACE /etc/conf.d/ssid first"
return 1
fi
}
start() {
checkconfig || return 1
ebegin "Setting ssids"
for iface in $IFACES; do
available=$( iwlist ${iface} scanning 2>&1 | sed -ne 's/^ *ESSID:"\(.*\)"$/\1/p' )
eval SSIDS=( \$${iface}_SSIDS )
if [ -z $SSIDS ]; then
ssid="any"
key="off"
eerror "${iface}_SSIDS not set in /etc/conf.d/ssid"
else
for ssid in $SSIDS; do
for avail in $available; do
if [ $avail = $ssid ]; then
eval key=( \$${iface}_${ssid} )
if [ -z $key ]; then
eerror "${iface}_$ssid not set in /etc/conf.d/ssid"
key="off"
ssid="any"
fi
break 2
fi
done
ewarn "No configured ssids broadcasting on $iface"
eval IFACE_default=( \$${iface}_default )
if [ -z $IFACE_default ]; then
ssid="any" key="off"
ewarn "No default ssid set for ${iface}"
else
ssid=$IFACE_default
eval key=( \$${iface}_${ssid} )
einfo "Using default ssid for ${iface}"
fi
done
fi
einfo "Setting ssid to $ssid on $iface"
iwconfig $iface essid "$ssid"
iwconfig $iface key $key
done
eend 0
}
stop() {
checkconfig || return 1
for iface in $IFACES; do
ebegin "Unsetting ssids"
einfo "Unsetting ssid on $iface"
iwconfig $iface essid any
iwconfig $iface key off
done
eend 0
}
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in your case, I suppose an automatic wireless capability detection would suit. any ideas? (but only detection of the interfaces in the IFACES variable)
for the case of two access points without SSIDs then the best one would be chosen (think windows xp wireless utility (which *requires* ssid broadcast) ) only better |
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UberLord
Retired Dev
Joined: 18 Sep 2003
Posts: 6835
Location: Blighty
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| Posted: Tue Jan 25, 2005 2:20 pm Post subject: |
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| martinoc wrote: |
in your case, I suppose an automatic wireless capability detection would suit. any ideas? (but only detection of the interfaces in the IFACES variable) |
| Code: |
if ! grep -q "${iface}:" /proc/net/wireless ; then
echo "${iface} is not a wireless interface"
fi
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| Quote: |
for the case of two access points without SSIDs then the best one would be chosen (think windows xp wireless utility (which *requires* ssid broadcast) ) only better |
Who defines the best one? You? How? You have no code to detect if you've associated with any AP.
The driver defines the best one? Different drivers select different AP's based on different criteria.
I suggest you emerge >=baselayout-1.11.8 and checkout the /lib/rcscripts/net.modules.d/iwconfig file for sample code to test association, picking AP's based on availability, signal strength and other things.
BTW, the XP wireless Zero Configuration only requires ssid broadcast to configure the AP on the client. Once it's been configured you can turn off broadcasting. |
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martinoc
n00b
Joined: 12 Jan 2005
Posts: 12
Location: Ireland
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| Posted: Tue Jan 25, 2005 3:33 pm Post subject: |
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| Quote: |
for the case of two access points without SSIDs then the best one would be chosen (think windows xp wireless utility (which *requires* ssid broadcast) ) only better |
by best one, i mean best preference from the user's point of view based on how they have ordered their $<iface>_$<ssid> list.
The functionality works for me in the environment in which i use wireless equipment.
btw, although the support exists in the newer baselayout, I am taking this primarily as a scripting excersise for my own benefit. But if any aspect of my script lends any ideas to the baselayout then im happy.
anyone not ready to use baselayout-1.11.X could find this a quick and dirty script to use in the mean time |
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UberLord
Retired Dev
Joined: 18 Sep 2003
Posts: 6835
Location: Blighty
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| Posted: Tue Jan 25, 2005 3:42 pm Post subject: |
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| martinoc wrote: |
btw, although the support exists in the newer baselayout, I am taking this primarily as a scripting excersise for my own benefit. But if any aspect of my script lends any ideas to the baselayout then im happy.
anyone not ready to use baselayout-1.11.X could find this a quick and dirty script to use in the mean time |
I'm always open for ideas about how to improve baselayout Although, if you write any patches you may want to post them to bugs.gentoo.org instead of here.
I hope I was able to help your scripting skills - or at least a little sed |
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martinoc
n00b
Joined: 12 Jan 2005
Posts: 12
Location: Ireland
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| Posted: Fri Jan 28, 2005 1:11 pm Post subject: |
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well, here is the most up to date version of my script.
I've worked out most of the bugs.
| Code: | #!/sbin/runscript
#NB: Config is in /etc/conf.d/ssid
depend() {
use hotplug pcmcia
before net.*
}
checkconfig() {
if [ -z "$IFACES" ]; then
eerror "You need to setup IFACE /etc/conf.d/ssid first"
return 1
fi
}
start() {
checkconfig || return 1
ebegin "Setting ssids"
for iface in $IFACES; do
if [ -z "`iwconfig 2>&1 | grep $iface`" ]; then
ewarn "$iface not found, skipping"
continue
fi
if ! grep -q "${iface}:" /proc/net/wireless ; then
ewarn "$iface is not a wireless device, skipping"
continue
fi
available=$( iwlist ${iface} scanning 2>&1 | sed -ne 's/^ *ESSID:"\(.*\)"$/\1/p' )
eval SSIDS=( \"\$${iface}_SSIDS\" )
if [ -z "$SSIDS" ]; then
ssid="any"
key="off"
ewarn "${iface}_SSIDS not set in /etc/conf.d/ssid"
else
local ssid_found=0
for ssid in $SSIDS; do
for avail in $available; do
if [ $avail = $ssid ]; then
eval key=( \"\$${iface}_${ssid}\")
if [ -z "$key" ]; then
ewarn "${iface}_$ssid not set in /etc/conf.d/ssid"
key="off"
ssid="any"
fi
local ssid_found=1
break 2
fi
done
done
if [ $ssid_found -eq 0 ]; then
ewarn "No configured ssids broadcasting on $iface"
eval default_IFACE=( \"\$default_${iface}\" )
if [ -z "$default_IFACE" ]; then
ssid="any"
key="off"
ewarn "No default ssid set for ${iface}"
else
ssid=$default_IFACE
eval key=( \"\$${iface}_${ssid}\" )
einfo "Using default ssid for ${iface}"
fi
fi
fi
einfo "Setting ssid to $ssid on $iface"
iwconfig $iface essid "$ssid"
iwconfig $iface key $key
done
eend 0
}
stop() {
checkconfig || return 1
ebegin "Unsetting ssids"
for iface in $IFACES; do
if [ -z "`iwconfig 2>&1 | grep $iface`" ]; then
ewarn "$iface not found, skipping"
continue
fi
if ! grep -q "${iface}:" /proc/net/wireless ; then
ewarn "$iface is not a wireless device, skipping"
continue
fi
einfo "Unsetting ssid on $iface"
iwconfig $iface essid any
iwconfig $iface key off
done
eend 0
}
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hope it proves usefull to someone else as it does to me |
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