[Vserver] Dummy device creation without race states
The creation of the dummy devices is ugly and has races ('dummy0' is
used by every 'vserver ... start' instance which conflicts with the
parallel vserver startup). 'dummy' would be ideally but is not
supported by the kernel.
I've attached what I was thinking, roughly. Yes, this is part of a much larger script... I'll share it with everyone when it's more complete.
One problem with this code is that there's no real way of dumping the vserver interfaces when you're done. I can't think of others off the top of my head, but they're probably there.
vstohex () {
[ -n "$1" ] || return 1
local oct1=$((${1} / 256))
local oct2=$((${1} % 256))
local -a out=()
for seg in $oct1 $oct2 ; do
hex1=$(($seg / 16))
[ "$hex1" = "15" ] && hex1=f
[ "$hex1" = "14" ] && hex1=e
[ "$hex1" = "13" ] && hex1=d
[ "$hex1" = "12" ] && hex1=c
[ "$hex1" = "11" ] && hex1=b
[ "$hex1" = "10" ] && hex1=a
hex2=$(($seg % 16))
[ "$hex2" = "15" ] && hex2=f
[ "$hex2" = "14" ] && hex2=e
[ "$hex2" = "13" ] && hex2=d
[ "$hex2" = "12" ] && hex2=c
[ "$hex2" = "11" ] && hex2=b
[ "$hex2" = "10" ] && hex2=a
[EMAIL PROTECTED]
done
echo "${out[0]}:${out[1]}"
}
if [ - "${BUILD_VSIF}" ] && ! ip link ls ${VSERVER_NAME} 2> /dev/null ; then
olddummylist=($(ip link ls | gawk '$2 ~ /^dummy/ {print $2}' | sed 's/:$//g' | sort))
insmod -o new dummy
newdummylist=($(ip link ls | gawk '$2 ~ /^dummy/ {print $2}' | sed 's/:$//g' | sort))
if [ "[EMAIL PROTECTED]" = "[EMAIL PROTECTED]" ] ; then
${LOGERROR} "Sorry, no dummy support in kernel!"
else
for nd in [EMAIL PROTECTED] ; do
for od in [EMAIL PROTECTED] ; do
[ "$nd" = "$od" ] && continue 2
done
dummylock=/var/lock/vserver/.lock.${nd}
[ -f "$dummylock" ] && continue
echo $$ >> $dummylock
hexend=$(vstohex ${S_CONTEXT})
mac="ff:ff:ff:ff:${hexend}"
ip link set dev ${nd} address ${mac}
nameif ${VSERVER_NAME} ${mac} || ${LOGERROR} "Problem setting up the dummy interface"
rm -f ${dummylock}
break
done
fi
fi
if [ "$BUILD_VSIF" ] ; then
if ! ip link ls ${VSERVER_NAME} > /dev/null 2>&1 ; then
${LOGERROR} "Dummy interface ${VSERVER_NAME} doesn't exist!"
else
ip addr flush ${VSERVER_NAME}
for ipaddr in ${IPROOT} ; do
ip addr add dev ${VSERVER_NAME} $ipaddr
done
fi
fi
vstohex () {
[ -n "$1" ] || return 1
local oct1=$((${1} / 256))
local oct2=$((${1} % 256))
local -a out=()
for seg in $oct1 $oct2 ; do
hex1=$(($seg / 16))
[ "$hex1" = "15" ] && hex1=f
[ "$hex1" = "14" ] && hex1=e
[ "$hex1" = "13" ] && hex1=d
[ "$hex1" = "12" ] && hex1=c
[ "$hex1" = "11" ] && hex1=b
[ "$hex1" = "10" ] && hex1=a
hex2=$(($seg % 16))
[ "$hex2" = "15" ] && hex2=f
[ "$hex2" = "14" ] && hex2=e
[ "$hex2" = "13" ] && hex2=d
[ "$hex2" = "12" ] && hex2=c
[ "$hex2" = "11" ] && hex2=b
[ "$hex2" = "10" ] && hex2=a
[EMAIL PROTECTED]
done
echo "${out[0]}:${out[1]}"
}
if [ "${BUILD_VSIF}" != "" ] && ! ip addr ls ${VSERVER_NAME} 2>
/dev/null ; then
dummylist=($(ip link ls | gawk '$2 ~ /^dummy/ {print $2}' |
sed 's/:$//g' | sort))
insmod -o new dummy
newdummylist=($(ip link ls | gawk '$2 ~ /^dummy/ {print $2}' |
sed 's/:$//g' | sort))
if [ "[EMAIL PROTECTED]" = "[EMAIL PROTECTED]" ] ; then
${LOGERROR} "Sorry, no dummy support in kernel!"
else
for nd in [EMAIL PROTECTED] ; do
for od in ${olddummylist} ; do
[ "$nd" = "$od" ] && continue 2
done
dummylock=/var/lock/vserver/.lock.${nd}
[ -f "$dummylock" ] && continue
echo $$ >> $dummylock
hexend=$(vstohex ${S_CONTEXT})
mac="ff:ff:ff:ff:${hexend}"
ip link set dev ${nd} address ${mac}
nameif ${VSERVER_NAME} ${mac} || continue
rm -f ${dummylock}
break
done
fi
fi
Re: [Vserver] Dummy device creation without race states
On Wed, Mar 31, 2004 at 01:41:14AM +, Liam Helmer wrote:
> The creation of the dummy devices is ugly and has races ('dummy0' is
> used by every 'vserver ... start' instance which conflicts with the
> parallel vserver startup). 'dummy' would be ideally but is not
> supported by the kernel.
>
>I've attached what I was thinking, roughly. Yes, this is part of a
>much larger script... I'll share it with everyone when it's more
>complete.
>One problem with this code is that there's no real way of dumping the
>vserver interfaces when you're done. I can't think of others off the
>top of my head, but they're probably there.
>vstohex () {
>[ -n "$1" ] || return 1
>local oct1=$((${1} / 256))
>local oct2=$((${1} % 256))
>local -a out=()
>for seg in $oct1 $oct2 ; do
>hex1=$(($seg / 16))
>[ "$hex1" = "15" ] && hex1=f
>[ "$hex1" = "14" ] && hex1=e
>[ "$hex1" = "13" ] && hex1=d
>[ "$hex1" = "12" ] && hex1=c
>[ "$hex1" = "11" ] && hex1=b
>[ "$hex1" = "10" ] && hex1=a
>hex2=$(($seg % 16))
>[ "$hex2" = "15" ] && hex2=f
>[ "$hex2" = "14" ] && hex2=e
>[ "$hex2" = "13" ] && hex2=d
>[ "$hex2" = "12" ] && hex2=c
>[ "$hex2" = "11" ] && hex2=b
>[ "$hex2" = "10" ] && hex2=a
>[EMAIL PROTECTED]
>done
impressive, but
printf "%s:%02x" eth0 12345
is a good solution too (for bash)
best,
Herbert
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Re: [Vserver] Dummy device creation without race states
On Wed, 2004-03-31 at 05:11, Herbert Poetzl wrote:
On Wed, Mar 31, 2004 at 01:41:14AM +, Liam Helmer wrote:
printf "%s:%02x" eth0 12345
Ooh, cool. That's much nicer. So, after fixing a couple of other bugs too, it should look more like this:
vstohex () {
[ -n "$1" ] || return 1
local oct1=$((${1} / 256))
local oct2=$((${1} % 256))
printf "%02:%02" ${oct1} ${oct2}
}
if [ -n "${BUILD_VSIF}" ] && ! /sbin/ip link ls ${VSERVER_NAME} > /dev/null 2>&1 ; then
olddummylist=($(/sbin/ip link ls 2> /dev/null | gawk '$2 ~ /^dummy/ {print $2}' | sed 's/:$//g' | sort))
insmod -o dummy-${VSERVER_NAME} dummy
newdummylist=($(/sbin/ip link ls 2> /dev/null | gawk '$2 ~ /^dummy/ {print $2}' | sed 's/:$//g' | sort))
if [[ "[EMAIL PROTECTED]" = "[EMAIL PROTECTED]" ]] ; then
${LOGERROR} "Sorry, no dummy support in kernel!"
else
for nd in [EMAIL PROTECTED] ; do
for od in [EMAIL PROTECTED] ; do
[ "$nd" = "$od" ] && continue 2
done
dummylock=/var/run/vserver/.lock.${nd}
[ -f "$dummylock" ] && continue
echo $$ >> $dummylock
hexend=$(vstohex ${S_CONTEXT})
mac="ff:ff:ff:ff:${hexend}"
ip link set dev ${nd} address ${mac}
nameif ${VSERVER_NAME} ${mac} || ${LOGERROR} "Couldn't set up interface ${VSERVER_NAME} correctly!"
rm -f ${dummylock}
break
done
fi
fi
if [ "$BUILD_VSIF" ] ; then
if ! /sbin/ip link ls ${VSERVER_NAME} > /dev/null 2>&1 ; then
${LOGERROR} "Dummy interface ${VSERVER_NAME} doesn't exist!"
else
ip addr flush ${VSERVER_NAME}
for ipaddr in ${IPROOT} ; do
ip addr add dev ${VSERVER_NAME} $ipaddr
done
fi
fi
is a good solution too (for bash)
best,
Herbert
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